Green Engineering for Campus Sustainability [1st ed.] 978-981-13-7259-9;978-981-13-7260-5

Table of contents :
Front Matter ....Pages i-xvii
Introduction (Abu Zahrim Yaser)....Pages 1-3
Environmental Sustainability of Universities: Critical Review of Best Initiatives and Operational Practices (Nurul Hana Mohamed, Zainura Zainon Noor, Cindy Lee Ik Sing)....Pages 5-17
The Green Vision of Technical University of Crete’s Campus (Nikolaos Sifakis, Efprepios Baradakis, Spyros Psychis, Theocharis Tsoutsos)....Pages 19-33
The Construction of Green Building Using Interlocking Brick System (Abdul Karim Mirasa, Chee-Siang Chong)....Pages 35-49
The Feasibility of Using Palm Oil Ash in the Mix Design of Interlocking Compressed Brick (Hidayati Asrah, Nadiah Sabana, Abdul Karim Mirasa, Nurmin Bolong, Lim Chung Han)....Pages 51-59
Second-Generation Bioethanol: Advancement of Ethanologenic Microorganisms Toward Industrial Production (Husnul Azan Tajarudin, Muhammad Syazwan Azmi, Muaz Mohd Zaini Makhtar, Mohd Firdaus Othman, Mardiana Idayu Ahmad)....Pages 61-79
Microalgae Chlorella as a Sustainable Feedstock for Bioethanol Production (Rahmath Abdulla, Tan Kah King, Siti Azmah Jambo, Ainol Azifa Faik)....Pages 81-103
Conversion of Landscape Waste into Bio-coke Solid Fuel (Santhana Krishnan, Mohd Fadhil Md Din, Shazwin Mat Taib, Norfarah Hanim Binti Kamaludin, Norhisyam Hanafi, Tamio Ida et al.)....Pages 105-118
The Effect of Enzyme Addition on the Anaerobic Digestion of Food Waste (Mariani Rajin, Abu Zahrim Yaser, Sariah Saalah, Yogananthini Jagadeson, Marhaini Ag Duraim)....Pages 119-131
Anaerobic Digestion of Organic Waste in UMS Campus for Resource Recovery and Waste Reduction (Newati Wid, Lucita Felicity Ayut)....Pages 133-143
Green Engineering for Waste Management System in University—A Case Study of Universitas Gadjah Mada, Indonesia (Arif Kusumawanto, Mega Setyowati)....Pages 145-161
Sustainable Waste Management in Higher Education Institutions—A Case Study in AC Tech, Anna University, Chennai, India (Jayapriya Jayaprakash, Hema Jagadeesan)....Pages 163-172
Food Waste Composting at Faculty of Engineering, Universiti Malaysia Sabah (Sariah Saalah, Mariani Rajin, Abu Zahrim Yaser, Nur Ain Syafiqah Azmi, Ahmad Fathuddin Fikri Mohammad)....Pages 173-191
Characterization of University Residential and Canteen Solid Waste for Composting and Vermicomposting Development (Nurmin Bolong, Ismail Saad)....Pages 193-206
Sewage Treatment in Campus for Recycling Purpose: A Review (Abu Zahrim Yaser, Nurliyana Nasuha Safie)....Pages 207-243
Advanced Treatment of Campus Sewage by MV/UV/O3 for Water Reclamation (Shengying Gong, Yanting Wang, Jie Fu)....Pages 245-259

Citation preview

Abu Zahrim Yaser   Editor

Green Engineering for Campus Sustainability

Green Engineering for Campus Sustainability

Abu Zahrim Yaser Editor

Green Engineering for Campus Sustainability

123

Editor Abu Zahrim Yaser Faculty of Engineering Universiti Malaysia Sabah Kota Kinabalu, Sabah, Malaysia

ISBN 978-981-13-7259-9 ISBN 978-981-13-7260-5 https://doi.org/10.1007/978-981-13-7260-5

(eBook)

Library of Congress Control Number: 2019934776 © Springer Nature Singapore Pte Ltd. 2020 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature Singapore Pte Ltd. The registered company address is: 152 Beach Road, #21-01/04 Gateway East, Singapore 189721, Singapore

To my family

Waste management at busy street of Delhi, India

Foreword

I am delighted to write this foreword, not only because Dr. Abu Zahrim is one of my strong team members engaging with the Universiti Malaysia Sabah (UMS) EcoCampus agenda, but because I believe deeply in the educative values of green engineering toward sustainability. Indeed, I am glad and impressed that Dr. Abu and his team members mainly from the engineering background have taken the initiative to publish some of the evidence-based solutions and innovative technologies to underpin and support the implementation of Sustainable Development Goals (SDGs) in the campus community which could set an example to other sectors and businesses. Dr. Abu is a very dedicated and productive researcher with a strong interest in composting toward zero food waste. He is an efficient decision-maker with works always completed ahead of time in which this character has made him one of the very valuable contributors to our sustainability initiatives in campus. In addition, Dr. Abu has a heartily commitment to empower the stakeholders in campus and local community by sharing his knowledge and research findings as well as giving technical support. I strongly believe that this book written by him and researchers from various countries with innovative ideas, evidence-based good practices, and technical information will definitely benefit the readers. Sabah is blessed with abundant resources. UMS is presently one of the two public universities in Sabah which has strong academic and research strengths in the environment-related field, besides having a beautiful and scenery campus. UMS has striven to cultivate environmental citizenship among students and staff through university activities, practices, and operations, besides contributing toward the sustainability of the local and global environment especially since the commitment to be a leading model of the “new flagship EcoCampus” in 2013. The United Nations’ Transforming Our World: The 2030 Agenda for Sustainable Development with 17 SDGs and their associated 169 targets were agreed by all countries in September 2015. Education and research are explicitly recognized in a number of the SDGs, and universities have a direct role in addressing these. Universities have a vital role to act a steward of development sustainability through teaching and learning, research, infrastructure development, management and operational practices and campus experience. vii

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Through research and training of research leaders, universities are at the forefront of finding sustainable social, economic, environmental, and technical solutions to global problems. The necessity for environmentally-friendly technologies in the future will require the expertise of engineers by incorporating sustainability into products, processes, technology systems, and services, which involves the design for energy efficiency, mass efficiency, and low environmental emissions. Dr. Abu and the contributors of this book have demonstrated their commitment and responsibility as green guardians as well as research leaders in sustainability. I truly hope that this book will enlighten and empower the campus community and public to make the difference toward the achievement of SDGs by 2030.

Kota Kinabalu, Malaysia

Prof. Dr. How Siew Eng Director, EcoCampus Management Centre, Universiti Malaysia Sabah

Acknowledgements

The editor gratefully acknowledges the following individuals for their time and efforts in assisting the editor with the reviewing of manuscript. This book would not have been possible without the commitment of the reviewers. • • • • • • • • • • • • • • •

Asha Embrandiri Ayu Haslija Abu Bakar Emma Suali George Z. Kyzas Husnul Azan Tajarudin Lee Kiat Moon Md. Abdul Mannan Md. Lutfor Rahman Mega Setyowati Mohd. Aizudin Abd Aziz Syeed Saifulazry Wan Khairul Muzammil Wu Ta Yeong Yasmin Che Ani Zainura Zainon Noor

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Contents

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Abu Zahrim Yaser Environmental Sustainability of Universities: Critical Review of Best Initiatives and Operational Practices . . . . . . . . . . . . . . . . . . . . . Nurul Hana Mohamed, Zainura Zainon Noor and Cindy Lee Ik Sing The Green Vision of Technical University of Crete’s Campus . . . . . . . Nikolaos Sifakis, Efprepios Baradakis, Spyros Psychis and Theocharis Tsoutsos The Construction of Green Building Using Interlocking Brick System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Abdul Karim Mirasa and Chee-Siang Chong The Feasibility of Using Palm Oil Ash in the Mix Design of Interlocking Compressed Brick . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hidayati Asrah, Nadiah Sabana, Abdul Karim Mirasa, Nurmin Bolong and Lim Chung Han Second-Generation Bioethanol: Advancement of Ethanologenic Microorganisms Toward Industrial Production . . . . . . . . . . . . . . . . . . . Husnul Azan Tajarudin, Muhammad Syazwan Azmi, Muaz Mohd Zaini Makhtar, Mohd Firdaus Othman and Mardiana Idayu Ahmad Microalgae Chlorella as a Sustainable Feedstock for Bioethanol Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rahmath Abdulla, Tan Kah King, Siti Azmah Jambo and Ainol Azifa Faik Conversion of Landscape Waste into Bio-coke Solid Fuel . . . . . . . . . . . Santhana Krishnan, Mohd Fadhil Md Din, Shazwin Mat Taib, Norfarah Hanim Binti Kamaludin, Norhisyam Hanafi, Tamio Ida, Mohd Suhaizan Shamsuddin and Shreeshivadasan Chelliapan

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The Effect of Enzyme Addition on the Anaerobic Digestion of Food Waste . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mariani Rajin, Abu Zahrim Yaser, Sariah Saalah, Yogananthini Jagadeson and Marhaini Ag Duraim

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Anaerobic Digestion of Organic Waste in UMS Campus for Resource Recovery and Waste Reduction . . . . . . . . . . . . . . . . . . . . Newati Wid and Lucita Felicity Ayut

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Green Engineering for Waste Management System in University—A Case Study of Universitas Gadjah Mada, Indonesia . . . . . . . . . . . . . . . Arif Kusumawanto and Mega Setyowati

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Sustainable Waste Management in Higher Education Institutions—A Case Study in AC Tech, Anna University, Chennai, India . . . . . . . . . . Jayapriya Jayaprakash and Hema Jagadeesan

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Food Waste Composting at Faculty of Engineering, Universiti Malaysia Sabah . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sariah Saalah, Mariani Rajin, Abu Zahrim Yaser, Nur Ain Syafiqah Azmi and Ahmad Fathuddin Fikri Mohammad Characterization of University Residential and Canteen Solid Waste for Composting and Vermicomposting Development . . . . . . . . . Nurmin Bolong and Ismail Saad Sewage Treatment in Campus for Recycling Purpose: A Review . . . . . Abu Zahrim Yaser and Nurliyana Nasuha Safie Advanced Treatment of Campus Sewage by MV/UV/O3 for Water Reclamation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Shengying Gong, Yanting Wang and Jie Fu

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Editor and Contributors

About the Editor Abu Zahrim Yaser obtained his Ph.D. from Swansea University (UK). Dr. Zahrim’s research mainly focuses on the integrated wastewater treatment and composting and has been leading several projects since 2006. To date, Dr. Zahrim has published 1 book (Springer), 11 book chapters (including 1 chapter for encyclopedia), 31 journals, and 50+ other publications. He was the Guest Editor for Environmental Science and Pollution Research special issue (impact factor: 2.800). His paper entitled “Modelling and optimisation of coagulation of highly concentrated industrial grade leather dye by response surface methodology” was awarded the Chemical Engineering Journal Top Cited Papers (Elsevier). In addition, his group won Best Poster for a study entitled “Macromolecular flocculation of lignin particles” at Third International Conference on Recycling and Reuse of Materials (ICRM 2014), India. He won several medals in innovation competition including a gold medal for an invention called “UMS Residual Oil Trap” at iENA 2018, Germany. Besides that, he is actively involved as a reviewer for several journals. The Elsevier (UK) has recognized him as among the Outstanding Reviewers for the Chemical Engineering Journal (2017), Desalination (2010, 2017), Chemosphere (2017), Industrial Crops and Products journal (2015), and Journal of Environmental Chemical Engineering (2018). Dr. Zahrim was the director for the first Earth Day celebration at UMS (2018). He was the

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secretary for the 4th International Conference on Chemical and Bioprocess Engineering (ICCBPE 2012) and the Workshop on Progress in Wastewater Treatment and Reuse Technology (PWTRT-2013). Dr. Zahrim is a Visiting Scientist at the University of Hull and recipient of Universiti Malaysia Sabah Excellent Service Award (2015). Dr. Zahrim is a member of Institutions of Chemical Engineers (United Kingdom) and Board of Engineers, Malaysia. Currently, he is the Deputy Dean at Faculty of Engineering and the Chairperson for Waste Management Committee, EcoCampus Management Centre.

Contributors Rahmath Abdulla Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia; Energy Research Unit, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia Marhaini Ag Duraim Chemical Engineering Programme, Faculty of Engineering, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia Mardiana Idayu Ahmad Division of Bioprocess Technology, School of Industrial Technology, Universiti Sains Malaysia, Pulau Pinang, Malaysia; Division of Environment Technology, School of Industrial Technology, Universiti Sains Malaysia, Pulau Pinang, Malaysia Hidayati Asrah Civil Engineering Program, Faculty of Engineering, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia Lucita Felicity Ayut Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia Muhammad Syazwan Azmi Division of Bioprocess Technology, School of Industrial Technology, Universiti Sains Malaysia, Pulau Pinang, Malaysia Nur Ain Syafiqah Azmi Chemical Engineering Programme, Faculty of Engineering, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia Efprepios Baradakis Renewable & Sustainable Energy Lab, School of Environmental Engineering, Technical University of Crete, Chania, Greece Nurmin Bolong Civil Engineering Program, Faculty of Engineering, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia Shreeshivadasan Chelliapan Department of Engineering, Razak Faculty of Engineering and Informatics, Universiti Teknologi Malaysia, Kuala Lumpur, Malaysia

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Chee-Siang Chong Faculty of Engineering, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia Mohd Fadhil Md Din Center of Environmental Sustainability and Water Security (IPASA), Research Institute of Sustainable Environment (RISE), Universiti Teknologi Malaysia UTM, Johor Bahru, Johor, Malaysia; Department of Environmental Engineering, Faculty of Civil Engineering, Universiti Teknologi Malaysia UTM, Johor Bahru, Johor, Malaysia; Campus Sustainability Office, Universiti Teknologi Malaysia UTM, Johor Bahru, Johor, Malaysia Ainol Azifa Faik Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia Jie Fu Department of Environmental Science & Engineering, Fudan University, Shanghai, China Shengying Gong Department of Environmental Science & Engineering, Fudan University, Shanghai, China Lim Chung Han Civil Engineering Program, Faculty of Engineering, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia Norhisyam Hanafi Campus Sustainability Office, Universiti Teknologi Malaysia UTM, Johor Bahru, Johor, Malaysia Tamio Ida Kinki University, Higashiosaka, Japan Hema Jagadeesan Department of Biotechnology, PSG College of Technology, Coimbatore, Tamil Nadu, India Yogananthini Jagadeson Chemical Engineering Programme, Faculty Engineering, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia

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Siti Azmah Jambo Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia Jayapriya Jayaprakash Department of Applied Science and Technology, A.C. Technology, Anna University, Chennai, India Norfarah Hanim Binti Kamaludin Department of Environmental Engineering, Faculty of Civil Engineering, Universiti Teknologi Malaysia UTM, Johor Bahru, Johor, Malaysia Tan Kah King Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia Santhana Krishnan Center of Environmental Sustainability and Water Security (IPASA), Research Institute of Sustainable Environment (RISE), Universiti Teknologi Malaysia UTM, Johor Bahru, Johor, Malaysia; Department of Environmental Engineering, Faculty of Civil Engineering, Universiti Teknologi Malaysia UTM, Johor Bahru, Johor, Malaysia

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Arif Kusumawanto Universitas Gadjah Mada, Yogyakarta, Indonesia Muaz Mohd Zaini Makhtar Division of Bioprocess Technology, School of Industrial Technology, Universiti Sains Malaysia, Pulau Pinang, Malaysia Abdul Karim Mirasa Civil Engineering Program, Faculty of Engineering, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia Nurul Hana Mohamed School of Civil Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, Johor Bahru, Johor, Malaysia Ahmad Fathuddin Fikri Mohammad Chemical Engineering Programme, Faculty of Engineering, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia Zainura Zainon Noor School of Civil Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, Johor Bahru, Johor, Malaysia Mohd Firdaus Othman Division of Bioprocess Technology, School of Industrial Technology, Universiti Sains Malaysia, Pulau Pinang, Malaysia; Division of Environment Technology, School of Industrial Technology, Universiti Sains Malaysia, Pulau Pinang, Malaysia Spyros Psychis Renewable & Sustainable Energy Lab, School of Environmental Engineering, Technical University of Crete, Chania, Greece Mariani Rajin Chemical Engineering Programme, Faculty of Engineering, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia Ismail Saad Faculty of Engineering, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia Sariah Saalah Chemical Engineering Programme, Faculty of Engineering, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia Nadiah Sabana Civil Engineering Program, Faculty of Engineering, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia Nurliyana Nasuha Safie Faculty of Engineering, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia Mega Setyowati Universitas Gadjah Mada, Yogyakarta, Indonesia Mohd Suhaizan Shamsuddin Office of the Asset and Development, Universiti Teknologi Malaysia UTM, Johor Bahru, Johor, Malaysia Nikolaos Sifakis Renewable & Sustainable Energy Lab, School of Environmental Engineering, Technical University of Crete, Chania, Greece Cindy Lee Ik Sing School of Civil Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, Johor Bahru, Johor, Malaysia

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Shazwin Mat Taib Department of Environmental Engineering, Faculty of Civil Engineering, Universiti Teknologi Malaysia UTM, Johor Bahru, Johor, Malaysia; Campus Sustainability Office, Universiti Teknologi Malaysia UTM, Johor Bahru, Johor, Malaysia Husnul Azan Tajarudin Division of Bioprocess Technology, School of Industrial Technology, Universiti Sains Malaysia, Pulau Pinang, Malaysia; Cluster of Solid Waste Management, Engineering Campus, Universiti Sains Malaysia, Pulau Pinang, Malaysia Theocharis Tsoutsos Renewable & Sustainable Energy Lab, School of Environmental Engineering, Technical University of Crete, Chania, Greece Yanting Wang Department of Environmental Science & Engineering, Fudan University, Shanghai, China Newati Wid Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia; Water Research Unit, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia Abu Zahrim Yaser Chemical Engineering Programme, Faculty of Engineering, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia

Introduction Abu Zahrim Yaser

The campus is a symbol of idealism, high intelligence and that is why its community should have growth mindsets that can improve environmental sustainability; which not only adapts and reacts to the severe environmental conditions but that can generate profits from it, e.g. compost or fuel from the generation of food waste. It is undeniable that the general public has high expectation and trust in the capabilities of the campus community. Therefore, the campus community should be the best example of implementing an environmental sustainability agenda. To achieve this stage, the campus community should move dynamically with a more critical thinking and creative solution. The solution should be workable and sustainable. With these aims in mind, this is the purpose of this book being published in front of the reader. Without exaggeration, the incorporation of sustainability elements and the latest technologies is essential so that the process can be carried out more easily and effectively. Among others, Mohamed et al. (Chap. 2) suggested that energy efficiency, waste management and water conservation should be incorporated into a holistic university’s environmental sustainability plan. Most of the time, proper planning will produce a good result. In term of energy, Tsoutsos’s group (Chap. 3) explained various actions dedicated for energy saving at Technical University of Crete (TUC), Greece and ultimately, they successfully reduced about 20% in energy consumption in the campus. Construction of buildings at university causes significant increase in energy consumption and a new method is developed to eradicate this problem. At Universiti Malaysia Sabah, Mirasa and Chong (Chap. 4) using the interlocking brick system to reduce energy consumption in the university building construction. The oil palm is

A. Z. Yaser (B) Chemical Engineering Programme, Faculty of Engineering, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Z. Yaser (ed.), Green Engineering for Campus Sustainability, https://doi.org/10.1007/978-981-13-7260-5_1

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the world’s most important oil crop that produces crude palm oil (CPO) and palm kernel oil (PKO), respectively. However, the production of a large amount of crude palm oil (CPO) leads to enormous quantities of wastes. Fortunately, it is interesting to note that Hidayati et al. (Chap. 5) demonstrated that palm oil waste is feasible to be blended with clay in the interlocking brick system. To help in mitigating the effects of global warming, the campus must reduce its dependence on fossil fuels to produce energy. Food waste and landscape waste are a readily available source of renewable energy. In this regard, Tajaruddin et al. reviewed the production chain of refining lignocellulosic biomass, production of sugar from lignocellulosic biomass during enzymatic hydrolysis and the fermentation of the produced sugars to bioethanol (Chap. 6). Rahmath et al. (Chap. 7) reported that production of bioethanol was achieved by fermentation process with the use of yeast Saccharomyces cerevisiae. Valuable products such as bio-coke and bio-oil can be obtained by pyrolysis/carbonization of landscape wastes. Krishnan et al. (Chap. 8) evaluated the suitability of landscape wastes for making bio-coke at Universiti Teknologi Malaysia, Johor, Malaysia. Anaerobic digestion (AD) is one of the oldest known processes utilised for the treatment of organic wastes. The basis of this treatment method is the evolution of methane via degradation in the absence of oxygen. The numerous advantages of anaerobic digestion include the low operating costs as minimal chemicals required, pathogen removal, higher loading rates are possible and the formation of biogas from the metabolism of more than 90% of organic material. Nevertheless, optimization of large-scale AD process is still an issue up to now. In order to optimise the process, Mariani et al. investigated the effects of lipase addition on the biogas production (Chap. 9). Due to the constant growth of the world’s population, there is a higher demand for fertilisers, including phosphate salts, to enrich soils. Besides producing biogas, AD also shows potential in generating phosphate salts. In this book, Newati et al. (Chap. 10) reported that anaerobic digestion of food waste could recover phosphorus in the form of struvite with 136 g struvite/g food waste. Green engineering is introduced so that the engineer would prioritise environmental protection mindset in their design rather solely based on profit. Arif and Mega (Chap. 11) presented the concept of green engineering as well as green architecture. Later, they reported the effort of waste management including organic wastes composting that taking place at Universitas Gadjah Mada, Indonesia. Composting is a bio-chemical aerobic degradation process of organic waste materials that can change the organic waste into valuable humus-like end-products called compost. Besides can reduce organic wastes/food waste to the landfill, the compost can be utilised as a soil conditioner and can be sold if there is excess production of compost. In addition, Jayapriya and Jagadeesan (Chap. 12) shared with us the composting effort using the simple in-vessel system at Anna University, Chennai, India. At Universiti Malaysia Sabah, Sariah et al. (Chap. 13) evaluated the composition of waste produce from Faculty of Engineering cafeteria and then reported that composting could reduce ~ 46% of the mixture of food waste and landscape waste in 20 days. Vermicomposting, i.e. compost production using worm as degrader is

Introduction

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suitable for further degradation of stable compost or ‘cold’ compost. In this book, Nurmin and Ismail (Chap. 14) compare the composting and vermicomposting effectiveness for the treatment of food wastes from various places. Sewage management is one of the important aspects that require attention from university management since there is an increment of student intake from year to year. The treated sewage effluent and sewage sludge (i.e. sludge produced from biological sewage treatment) contain nutrients such as nitrogen and phosphorus that can be recycled. Zahrim and Liyana (Chap. 15) review several efforts on campus sewage treatment and recycling potential. Finally, at Fudan University, China, Gong et al. (Chap. 16) studied the microwave/electrode-less ultraviolet/ozone (MV/UV/O3) system for treatment of treated sewage from the membrane bioreactor (MBR) process to meet the requirements for campus water reclamation. All effort to greening the campus need full cooperation among the top level management, academic staff, support staff as well as students. Every individual in the campus has their own role to ensure campus sustainability. Apart from good monitoring, well-written policy by top-level management could assist in shaping the campus community mind and attitude towards sustainability. The effort should not only ‘oneoff’ effort or just for the sake of ranking but the effort should be taken continuously and seriously to ensure the sustainability of campus. Sustainable campus environment would inculcate conducive learning and teaching condition among the student as well as having a great potential for the successful edutourism.

Environmental Sustainability of Universities: Critical Review of Best Initiatives and Operational Practices Nurul Hana Mohamed, Zainura Zainon Noor and Cindy Lee Ik Sing

Abstract Nowadays, there have been various environmental sustainability initiatives implemented by the Higher Education Institutions (HEIs) through research, education, community involvement and campus operations. By embedding an effective initiative as well as best practices, environmental sustainability performance of universities can be improved. Realising the benefits of these factors, this book chapter aims at constructively reviewing the university’s environmental sustainability initiatives (ESI) by highlighting underlying issues and necessary improvements. To accomplish this, the ESI of three research universities in Malaysia were reviewed in accordance with UI GreenMetric World University Ranking. Around 36 major initiatives as well as several environmental sustainability courses that have been conducted by all three research universities was categorised using the descriptions and rationales of the six (6) main environmental category in UI GreenMetric which are Setting and Infrastructure, Energy and Climate Change, Waste, Water, Transportation and Education and Research. It can be concluded that the key factors that should be included in the ESI plan are awareness and environmental knowledge, green space and land use management, energy efficiency and water conservation, natural resource limitation, climate change mitigation, waste minimisation, greenhouse gas emissions reduction, environmental education programme and research collaboration as well as environmental sustainability guidelines and policies. These factors can help and guide universities to produce a good and strategic plan in practicing and conducting ESI towards a better future. Keywords Environmental sustainability of universities · Environmental sustainability initiatives (ESI) · UI GreenMetric world university ranking · Setting and infrastructure · Energy and climate change · Waste · Water · Transportation and education and research

N. H. Mohamed (B) · Z. Z. Noor · C. L. I. Sing School of Civil Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor, Malaysia e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Z. Yaser (ed.), Green Engineering for Campus Sustainability, https://doi.org/10.1007/978-981-13-7260-5_2

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1 Introduction Over the past decades, many authors have highlighted the concept of sustainability and sustainable development in different sectors (Ragazzi and Ghidini 2017; Belu et al. 2014; Ivascu and Cioca 2015; Biasutti and Frate 2017; Holdsworth and Thomas 2016; Cioca et al. 2015; Scott 2014). In 1987, Brundtland Report defined sustainable development as the “development that meets the needs of the present without compromising the ability of future generation to meet their own need” (Report of the World Commission on Environment and Development: Our Common Future 1987). This has become one of the most recognised definitions of sustainable development. It has three main pillars; social sustainability, environmental sustainability and economic sustainability. To achieve sustainability, these three pillars of sustainability must be balanced in equal harmony (Ragazzi and Ghidini 2017). The role of Higher Education Institutions (HEIs) in sustainable development is universally recognised. They play a fundamental role in society and have the duty to adopt and promote the principles of sustainability in forming future generation and preparing future professionals (Ragazzi and Ghidini 2017; Corcoran and Wals 2004; Disterheft et al. 2013). Supporting this notion, Velazquez et al. (2006) referred sustainable university to “a higher educational institution, as a whole or as a part, that addresses, involves and promotes, on a regional or a global level, the minimisation of negative environmental, economic, societal and health effects generated in the use of their resources to fulfil its functions of teaching, research, outreach and partnership as well as stewardship in ways to help society making the transition to sustainable lifestyles”. This suggests that there should be sufficient environmental and sustainability concerns in the campus physical and academic planning processes when establishing a university (Alshuwaikhat and Abubakar 2008). Ragazzi (2017) stated that it is no longer possible to ignore campuses’ externalities on environmental quality and integrity and there are needs to consider sustainability in academic institutions. According to Alshuwaikhat (2008), universities can be considered as “small cities”, which may have heavy impacts on the environment due to their activities, movement of goods and persons inside campuses. He also added that the responsibility of educating students and the society about sustainability serves as one of the universities missions. One of the key factors to improve the university’s environmental sustainability performance is by implementing effective initiatives and best practices. Since the activities and operations of universities have a huge impact on the environment, campus sustainability has become an issue of global concern for university policy makers and planners (Alshuwaikhat and Abubakar 2008). In this book chapter, the effective initiatives and best practices in universities with the aim of highlighting underlying issues and necessary improvements are focused. To accomplish this aim, environmental sustainability initiatives (ESI) of three (3) research universities (RUs) in Malaysia were reviewed, namely Universiti Putra Malaysia (UPM), Universiti Malaya (UM), and Universiti Teknologi Malaysia (UTM). This RUs are ranked Top 100 in UI GreenMetric World University Ranking for Malaysia with UPM ranked 27th, UM ranked 34th and UTM ranked 66th.

Environmental Sustainability of Universities: Critical Review …

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2 Research University (RU) in Malaysia In the nineteenth century, German University is the first university to obtain the title Research University (RU) where instead of teaching, research activities are highly performed (Lehrer et al. 2009). In general definition, RU is a university that gives high priority in research as a major part of their mission (Altbach and Knight 2007). According to Atkinson and Blanpied (2008), developed countries use the concept of RU as a guideline for teaching, research and innovation excellence. Considering German University as a success model in promoting RU’s concept, other countries have duplicated this model including the United States (US) (Ramli et al. 2013). Due to the new development in research field and the idea of government’s support in university (Atkinson and Blanpied 2008), the US had established a new RU model. The model has then expanded through their concept and operation to become a complex organisation with variety of campuses, research centres, institutes and programmes. Ramli (2013) concluded that “the US RU is an independent organisation with absolute autonomy to direct the focus of research and direction of the university”. There are five public universities in Malaysia that have been appointed as RU. The five RUs are Universiti Malaya (UM), Universiti Kebangsaan Malaysia (UKM), Universiti Putra Malaysia (UPM), Universiti Sains Malaysia (USM) and Universiti Teknologi Malaysia (UTM). UM, UKM, UPM and USM were announced as the RU under 9th Malaysia Plan (2006) while UTM was announced under 10th Malaysia Plan (2010). In accordance with The National Higher Education Strategic Plan Beyond 2020, Malaysia’s RUs are required to focus primarily on research activities and to explore their intellectual capacity to become a model for other universities in Malaysia (Sheriff and Abdullah 2017). In this book chapter, only three RU were reviewed, which are UM, UPM and UTM. Table 1 shows the achievement of Malaysia’s RU according to world university rankings such as UI GreenMetric World University Rankings 2017, QS World University Rankings 2018, QS Asia University Rankings 2018 and Times Higher Education (THE) World University Rankings 2018.

Table 1 Malaysia’s Research University’s Rankings (Universitas Indonesia 2017; QS Top Universities 2018a, b; Times Higher Education 2018) Malaysia’s Research University

UI GreenMetric World University Rankings 2017

QS World University Rankings 2018

QS Asia University Rankings 2018

The World University Rankings 2018

UPM

27

202

36

601–800

UM

34

87

24

351–400

UTM

66

228

49

601–800

8

N. H. Mohamed et al.

3 UI GreenMetric World University Ranking Over a few years, HEI worldwide had set up and adopted various sustainability focus areas and goals in their campus operations (Razman et al. 2014). There were several measurement tools that have been produced to measure the impact of environment sustainability initiatives on the university’s governance and operation. The common mechanism used to measure the sustainability performance of a university is in the form of ranking. One of the most recognised university rankings is UI GreenMetric World University Ranking. It has been established by Universitas Indonesia (UI) in 2010. The main purpose of this ranking is to measure campus sustainability efforts based on environmental sustainability criteria. The UI GreenMetric gives a participated university impressive benefits such as internationalisation and recognition globally, increased awareness of sustainability issues through social change and action and also as a platform to build a networking with other universities worldwide (Universitas Indonesia 2018). During the design phase of UI GreenMetric, a few existing sustainability assessment systems and academic university rankings were studied including Holcim Sustainability Awards, GREENSHIP, Sustainability, Tracking, Assessment and Rating System (STARS), Green Report Card, Times Higher Education (THE) World University Rankings, QS World University Rankings, Academic Ranking of World Universities (ARWU) and Webometrics Ranking of World Universities (Webometrics) (Universitas Indonesia 2018). The ranking method is employed based on six (6) main categories, which are Setting and Infrastructure, Energy and Climate Change, Waste, Water, Transportation and Education and Research (Universitas Indonesia 2018). Since 2010, UI has been updating and improving environmental sustainability criteria and indicators to match with the diversity of each university.

4 Methodology The review was based on the ESI of three RU in Malaysia in accordance with the main environmental category in UI GreenMetric World University Ranking. Firstly, the existing ESI implemented by each RU was listed such as campaigns, events or programmes. Then, using the environmental category stated in UI GreenMetric, the ESI was categorised based on the environmental characteristic designed by universities to achieve environmental sustainability goals and targets. Lastly, the ESI was constructively reviewed by highlighting underlying issues and necessary improvements.

Environmental Sustainability of Universities: Critical Review …

9

5 Results and Discussion: Critical Review of ESI 5.1 List of Environmental Sustainability Initiative 5.1.1

Universiti Putra Malaysia (UPM)

UPM was first established as the School of Agriculture in 1931. Over the years, the status of UPM changes from School of Agriculture to College of Agriculture Malaya in 1947. Then, the Universiti Pertanian Malaysia was established in 1973. Due to the extended fields of studies, in 1997, the name Universiti Pertanian Malaysia was changed to Universiti Putra Malaysia by Prime Minister, Tun Dr Mahathir Mohammad (Universiti Putra Malaysia 2018a). UPM has at least 14 initiatives that have been carried out around the university under their Faculty of Environmental Studies (GREEN INITIATIVE). In UI GreenMetric World University Rankings, UPM has ranked 27th with total score 6420 (64%). The score for each main category is Setting and Infrastructure, 73%; Energy and Climate Change, 55%; Waste, 89%; Water, 72%; Transportation, 53% and Education and Research, 49%. Table 2 displays the UPM’s ESI contributed for this achievement.

5.1.2

Universiti Malaya (UM)

University of Malaya (UM) is Malaysia’s oldest university. UM has its root in Singapore with the establishment of King Edward VII College of Medicine in 1905. In 1962, University of Malaya Kuala Lumpur was established (2018a). UM has 9 main initiatives that have been carried out around the university. In UI GreenMetric World University Rankings, UM has ranked 34th with total score 6280 (63%). The score for each main category is Setting and Infrastructure, 62%; Energy and Climate Change, 56%; Waste, 79%; Water, 94%; Transportation, 62% and Education and Research, 37%. Table 3 depicts the UM’s ESI contributed for this achievement.

5.1.3

Universiti Teknologi Malaysia (UTM)

Universiti Teknologi Malaysia (UTM) contributes to the country’s technical and professional workforce since 1904 as one of the key players in engineering and knowledge and technological expertise. For over 70 years of difficulties and challenges especially in the early years, from Technical School to Technical College (in 1955) and then to Institut Teknologi Kebangsaan (in 1972), UTM was finally established in 1975 (Universiti Teknologi Malaysia 2018). UTM has at least 13 main initiatives that have been carried out around the university under their UTM Campus Sustainability (UTMCS). In UI GreenMetric World

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N. H. Mohamed et al.

Table 2 Environmental sustainability initiatives in UPM (Universiti Putra Malaysia 2018b) No.

Initiative

Environmental sustainability categories

1

Upcycling Innovation

Waste

2

Ipoh Car Free Day

Transportation

3

River of Life at Serdang

Water

4

Recycling@U Exhibition

Waste

5

Compost Pit

Waste

6

Urban Garden

Setting and Infrastructure

7

E-Waste [Mobile]

Waste

8

Used Cooking Oil Recycling Campaign

Waste

9

UPM Waste Bank

Waste

10

Waste Bank UPM-Kundasang

Waste

11

Monthly Tree Planting Program

Setting and Infrastructure

12

Saujana Lestari Program

Setting and Infrastructure

13

Sensory Garden

Setting and Infrastructure

14

Zero Net Carbon Emissions Programme

Energy and Climate Change and Transportation

15

Environmental sustainability courses: • Bachelor of Environmental Management • Bachelor of Environmental Science and Technology • Master of Environment • Master of Science and PhD

Education

University Rankings, UTM has ranked 66th with total score 5952 (60%). The score for each main category is Setting and Infrastructure, 75%; Energy and Climate Change, 56%; Waste, 79%; Water, 63%; Transportation, 45% and Education and Research, 44%. Table 4 demonstrates the UTM’s ESI contributed for this achievement.

5.2 Critical Review Based on UI GreenMetric’s Environmental Sustainability Categories 5.2.1

Setting and Infrastructure (SI)

According to UI GreenMetric, the purposes of this category are to provide more spaces for greenery in university and to safe guard the environment as well as the development of sustainable energy (Universitas Indonesia 2018). There are six (6) indicators in SI that focus on open space green area (or green space) including forest, planted vegetation and water absorbance area. There are a lot of environmental

Environmental Sustainability of Universities: Critical Review …

11

Table 3 Environmental sustainability initiatives in UM (Universiti Malaya 2018b) No.

Initiative

Environmental sustainability categories

1

UM Eco-Campus Initiatives

Setting and Infrastructure, Energy and Climate Change, Waste, Water and Transportation

2

UM Eco-Campus Blueprint

Setting and Infrastructure, Energy and Climate Change, Waste, Water and Transportation

3

UM Living Labs (UMLL)

Setting and Infrastructure, Energy and Climate Change, Waste, Water and Transportation

4

UM in Low Carbon Cities Framework (LCCF)

Energy and Climate Change

5

Rimba Project

Setting and Infrastructure

6

UM Cares Environmental Competition

Setting and Infrastructure, Energy and Climate Change, Waste, Water and Transportation

7

UM Cares Green Office

Energy and Climate Change and Waste

8

UM Zero Waste Campaign (UM ZWC)

Waste

9

Water Warriors

Water

10

Environmental sustainability courses: • Bachelor of Engineering (Environmental) • Bachelor of Science in Environmental Management (with 14 core and elective courses) • Master of Sustainability Science • Master of Science (Environmental Management Technology)

Education

benefits of green space such as improved air quality, decreased temperature, rainfall retention and reduced soil erosion. In general, green space is very important to the ecosystem and to the surrounding community (Refaat et al. 2016). Forest tree planting and urban garden programme are simple approaches from the ESI that can improve the amount of green space. However, these initiatives have a few disadvantages. For forest tree planting, although this programme is done monthly, the outcome cannot be achieved in the near future since it may take decades for trees to mature. For urban garden, it will take less time to grow, but the outcome will be much smaller compared to forest tree planting. Nevertheless, reforestation holds a promise to confront global warming. Therefore, these initiatives must be continued by planting trees in a large scale using inexpensive, fast-growing and suitable trees with the climate’s area and the most important steps are updating and monitoring the green space from time to time.

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N. H. Mohamed et al.

Table 4 Environmental Sustainability Initiatives in UTM (UTM Campus Sustainability 2018) No.

Initiative

Environmental sustainability categories

1

UTM Eco-Home

Setting and Infrastructure

2

Sustainable Arcade

Waste

3

Green Office Campaign: • Save Energy • Sustainable Meeting • Green Packaging • Green E-WASTE • Practice Recycling • Save Paper

Energy and Climate Change and Waste

4

Sustainable Energy Management (SEM): • UTM Self-Made Biodiesel • UTM Building Automation System • UTM A Cycling Campus • UTM Hybrid Car • UTM Optimal Audit Software • ASEAN Energy Management Scheme • UTM Carbon Calculator • UTM Electrical Billing Management System (EBMS)

Energy and Climate Change, Waste and Transportation

5

UTM Recycling Center (paper, glass, plastic, and aluminium)

Waste

6

Bio-Recycling Station (food waste and landscape waste)

Waste

7

Food Waste Utilization

Waste

8

Waste Separation Awareness and Procurement UTM

Waste

9

Program “Bring Your Own Container”

Waste

10

Sikal Electric Rakyat 1 Malaysia (SER1M)

Energy and Climate Change and Transportation

11

Car Free Day

Energy and Climate Change and Transportation

12

Energy Saving Campaign

Energy and Climate Change

13

Program of Water Conservation Activity

Water

14

Ground Water Project

Setting and Infrastructure and Water

15

Water Sustainability Program (WSP): Lata Jernih in Recreational Forests inside UTM campus

Setting and Infrastructure

16

Environmental sustainability courses: • Bachelor of Civil Engineering • Master of Engineering (Environmental Management) • Master of Philosophy (Environmental Engineering) • Master of Engineering (Environmental) • Master of Philosophy (Environmental) • Doctor of Philosophy (Environmental Engineering)

Education

Environmental Sustainability of Universities: Critical Review …

5.2.2

13

Energy and Climate Change (EC)

The aims of EC are to increase university’s efforts in building’s energy efficiency and to take care and focus more on nature and energy resources (Universitas Indonesia 2018). In UI GreenMetric, the EC has the highest weightage with eight (8) indicators in the areas of concern such as energy efficient appliance usage, implementation of smart buildings, renewable energy usage policy, total electricity use, energy conservation programmes, elements of green buildings, climate change adaptation and mitigation programmes, greenhouse gas emission reduction policy and carbon footprint (Universitas Indonesia 2018). The well-known initiative for these criteria is the establishment of Green Office (GO). According to Green Office Programme by WWF (2011), the basic principle of the GO initiative is to promote sustainable improvements in the environmental work by reducing the environmental impacts of office work. The GO initiatives include energy efficiency, sustainable management, environmental efficiency, waste management, environmental awareness and behaviour as well as climate change mitigation. These initiatives are able to give positive impact on staff’s health and their surroundings, which in turn would improve productivity.

5.2.3

Waste (WS)

Reducing waste generation is one of the most straightforward ways to save natural resources. In UI GreenMetric (Universitas Indonesia 2018), there are six (6) indicators in the WS category with the main purpose to encourage more waste treatment and recycling activities among university staff and students on campus. A good waste management will become a major factor in creating a sustainable environment. Fortunately, there is a simple approach to achieve this goal. For example, the common and basic ESI are Zero Waste Campaign, Recycling Activities and Environmental Awareness and Behaviour Programmes. Every university has a few campaigns and activities with waste management as a programme objective. The success rate is high, the process is easy to be sustained and the results are satisfactory. Composting practices also one of the common waste management programmes nowadays. For example, composting the universities cafeterias’ food waste. From this practice, the food waste will be handled properly, and the compost produced can be used as fertiliser and will further improves soil structure. However, the most environmentally and economically efficient and cost-effective way to manage waste is using waste minimisation strategy. According to Mallak (2014), waste minimisation is a “reduction of wastes at the point of generation with the perception of process due to wastes prevention and reduction”. The growing numbers of university’s staff and students will generally increase waste generation. Instead of focusing on reuse, recycling or waste treatment, creating an efficient process or practices to reduce waste at the point of generation is of crucial.

14

5.2.4

N. H. Mohamed et al.

Water (WR)

Another category in UI GreenMetric is water use (WR). There are four (4) indicators included in this category, which are the implementation of water conservative and recycling programmes, water efficient appliance’s use and treated water consumed. Its main purpose is to reduce water usage, not only among university’s staff and students, but importantly in university’s operation and management (Universitas Indonesia 2018). Water is the most importance resource in human life. It should be conserved to ensure that the availability of water resources will meet the current and future human demand since it is one of the limited natural resources. The main focus in water conservation effort is to reduce unnecessary water intake. University’s management should be aware of water consumption rate by monitoring water sources such as surface water resources and ground water levels. Besides, universities also need to inspect, improve and maintain the pipeline system within the campus to prevent leakage problem. The ESI for this aspect including awareness programme (helping staff and students to be more aware and understand the importance of water), recycling water (using grey water for irrigation and cleaning), rainwater harvesting (installing rainwater tanks) and using water efficient devices. According to Siwar (2014), the important goal in effective water resource planning is to treat water conservation as a source of new water supply. The ESI for water bodies in campus is very important to restore ecosystem services and natural habitats. The aim for this initiative is to increase the awareness and involvement in protecting water resources among university’s staff and students as well as the surrounding communities about the importance of clean water bodies by conducting a simple monitoring stewardship. Krasny (2015) revealed that naturebased stewardship does not only provides direct benefits to the campus environment, but can also enhance students’ sense of place and play a role in students’ mental well-being. 5.2.5

Transportation (TR)

In UI GreenMetric, TR category has eight (8) indicators that mainly focus on the number of vehicles (public and private vehicle), zero emission carbon footprint programme and transportation policies (Universitas Indonesia 2018). The purposes of TR category according to UI GreenMetric are to reduce the carbon emission and pollutant levels in universities, improve the safety and air quality, decrease noise pollution, as well as to increase students’ and staff physical activities. The famous ESI among universities is Car Free Day Programme. Basically, this programme is conducted once a month and the streets on certain areas in university will be closed for a few hours (8.00 am–4.30 pm). This will encourage university’s staff and student to walk or cycle around the campus or use environmentally friendly public transportations such as electric bicycle or hybrid car. To achieve maximum outcome from this programme, the transportation policy and pedestrian policy should be embedded and followed. University must provide a proper pedestrian area to assure the safety of consumers.

Environmental Sustainability of Universities: Critical Review …

15

Another ESI in this category is Carpooling Campaign. Carpooling, also known as car-sharing, can reduce the number of cars and vehicles on the road, which in return will reduce carbon emission and traffic congestion. The best part about carpooling is that it helps students and staff to save more money.

5.2.6

Education and Research (ED)

The purpose of ED category in UI GreenMetric is to give information on the environmental and sustainability education implemented in university teaching and learning (Universitas Indonesia 2018). This information is defined by the number of courses or subjects offered in university’s education programme related to environmental sustainability and by the sustainability research activities. There are seven (7) indicators in ED category that basically focus on sustainability effort in education and research, which are number of courses, research funding, publications, events, student organisations, website and report (Universitas Indonesia 2018). Environmental education (EE) is a very important process in providing students with environmental knowledge. As a result, students are able to develop a better understanding of environmental issues, generate the skills to solve the issues and take effective actions to keep a healthy environment. Universities are responsible to help students in understanding the effects of their decisions and actions toward environment. EE will become a lifelong learning process at creating responsible individuals that are aware and concern about environmental challenges in the future. Universities can improve EE by developing programme guidelines and policy as well as producing an innovative and flexible approaches not only for students, but also for university’s staff.

6 Conclusion To improve environmental sustainability performance and become a Green Campus, universities in Malaysia have implemented various ESIs through the years. By applying the environmental sustainability categories from UI GreenMetric, the ESI has been observed to give a positive impact towards university’s environmental sustainability management and to improve university’s ranking. Therefore, UI GreenMetric can be used as a guideline in constructing the best initiatives and operational practices. Although there was a study (Ragazzi and Ghidini 2017) stating that the UI GreenMetric needs to be improved and strengthen due to the imperfection of its method, there are other measurement methods or tools for examples GREENSHIP, Sustainability, Tracking, Assessment and Rating System (STARS) and Green Report Card as well as environmental criteria that can be referred to and implemented by the universities. Thus, it can be concluded that the key factors that should be included in the ESI plan are awareness and environmental knowledge, green space and land use

16

N. H. Mohamed et al.

management, energy efficiency and water conservation, natural resource limitation, climate change mitigation, waste minimisation, greenhouse gas emission reduction, environmental education programme and research collaboration, as well as environmental sustainability guidelines and policies. These factors can help and guide universities to set-up a good and strategic plan in practicing and conducting ESI towards a better future. To determine the success of the plan, all parties within the university including students, staff, management and the surrounding community must ensure that the monitoring can be conducted from time to time with a full commitment from all parties.

References Alshuwaikhat, H. M., & Abubakar, I. (2008). An integrated approach to achieving campus sustainability: Assessment of the current campus environmental management practices. Journal of Cleaner Production, 16(16), 1777–1785. Altbach, P. G., & Knight, J. (2007). The internationalization of higher education: Motivations and realities. Journal of Studies in International Education, 11(3–4), 290–305. Atkinson, R. C., & Blanpied, W. A. (2008). Research Universities: Core of the US science and technology system. Technology in Society, 30(1), 30–48. Belu, R., Chiou, R., Tseng, T.-L. B., & Cioca, L. (2014). Advancing sustainable engineering practice through education and undergraduate research projects. In ASME 2014 International Mechanical Engineering Congress and Exposition (pp V005T005A022–V005T005A022). American Society of Mechanical Engineers. Biasutti, M., & Frate, S. (2017). A validity and reliability study of the attitudes toward sustainable development scale. Environmental Education Research, 23(2), 214–230. Cioca, L.-I., Ivascu, L., Rada, E. C., Torretta, V., & Ionescu, G. (2015). Sustainable development and technological impact on CO2 reducing conditions in Romania. Sustainability, 7(2), 1637–1650. Corcoran, P. B., Wals, A. E. (2004). The problematics of sustainability in higher education: An introduction. In Higher education and the challenge of sustainability (pp 3–6). Springer. Disterheft, A., Caeiro, S., Azeiteiro, U. M., Leal Filho, W. (2013). Sustainability science and education for sustainable development in universities: A way for transition. In Sustainability assessment tools in higher education institutions (pp 3–27). Springer. Holdsworth, S., & Thomas, I. (2016). A sustainability education academic development framework (SEAD). Environmental Education Research, 22(8), 1073–1097. Ivascu, A., Cioca, L. (2015). From theory to practice: Evolution of sustainable development in organizations. In Innovation Vision 2020: From Regional Development Sustainability to Global Economic Growth (1). Krasny, M. E., & Delia, J. (2015). Natural area stewardship as part of campus sustainability. Journal of Cleaner Production, 106, 87–96. Lehrer, M., Nell, P., & Gärber, L. (2009). A national systems view of university entrepreneurialism: Inferences from comparison of the German and US experience. Research Policy, 38(2), 268–280. Mallak, S. K., Ishak, M. B., Mohamed, A. F. (2014). Waste minimization benefit and obstacles for solid industrial waste in Malaysia. IOSR Journal of Environmental Science, Toxicoogy and Food Technology (IOSR-JESTFT) 8(2), 43–52. QS Top Universities. (2018a). QS World University Rankings 2018: Malaysia. Retrieved July 4, 2018, from https://www.topuniversities.com/university-rankings/world-university-rankings/ 2018.

Environmental Sustainability of Universities: Critical Review …

17

QS Top Universities. (2018b). QS Asian University Rankings 2018: Malaysia. Retrieved July 4, 2018, from https://www.topuniversities.com/university-rankings/asian-university-rankings/ 2018. Ragazzi, M., & Ghidini, F. (2017). Environmental sustainability of universities: Critical analysis of a green ranking. Energy Procedia, 119, 111–120. Ramli, N., Zainol, Z. A., Aziz, J. A., Ali, H. M., Hassim, J., Hussein, W. M. H. W., et al. (2013). The concept of research university: The implementation in the context of Malaysian university system. Asian Social Science, 9(5), 307. Refaat, T., El-Halwagy, E., & El-Zoklah, M. (2016). Environmental benefits of green infrastructure techniques and applications. WIT Transactions on Ecology and the Environment, 204, 387–396. Report of the World Commission on Environment and Development: Our Common Future (1987) United Nations. Retrieved July 23, 2018, from http://www.un-documents.net/our-commonfuture.pdf. Razman, R., Abdullah, A. H., Wahid, A., Zaki, A. (2014). Sustainable development in higher education institutions (HEIs): Towards sustainable campus operations (SCO). Scott, R. (2014). Education for sustainability through a photography competition. Sustainability, 6(2), 474–486. Sheriff, N. M., & Abdullah, N. (2017). Research universities in Malaysia: What beholds? Asian Journal of University Education, 13(2), 35–50. Siwar, C., & Ahmed, F. (2014). Concepts, dimensions and elements of water security. Pakistan Journal of Nutrition, 13(5), 281. Times Higher Education. (2018). Times Higher Education World University Rankings 2018: Malaysia. Retrieved July 2, 2018, from https://www.timeshighereducation.com/world-universityrankings/2018/world-ranking#!/page/0/length/25/locations/MY/sort_by/rank/sort_order/asc/ cols/stats. Universitas Indonesia. (2017). List of Universities in Each Country (2017): Malaysia. Retrieved July 4, 2018, from http://greenmetric.ui.ac.id/detailnegara2017/?negara=Malaysia. Universitas Indonesia. (2018). Guideline: UI GreenMetric World University Rankings 2018. Universiti Putra Malaysia. (2018a). The story behind UPM. Retrieved July 11, 2018, from http:// www.upm.edu.my/about_us/history/the_story_behind_upm-8203. Universiti Putra Malaysia. (2018b). Faculty of Environmental Studies. Green initiative. Retrieved July 11, 2018, from http://www.env.upm.edu.my/green_initiative-3173?L=en. Universiti Malaya. (2018a). Our history. Retrieved July 11, 2018, from https://www.um.edu.my/ about-um/our-history. Universiti Malaya. (2018b). Sustainability@UM. Retrieved July 11, 2018, from https://www.um. edu.my/about-um/umique/sustainability@um. Universiti Teknologi Malaysia. (2018). Brief history of UTM. Retrieved July 11, 2018, from http:// www.utm.my/about/brief-history-of-utm/. UTM Campus Sustainability. (2018). Sustainability Initiative. July 12, 2018, from http://www.utm. my/sustainable/. Velazquez, L., Munguia, N., Platt, A., & Taddei, J. (2006). Sustainable university: What can be the matter? Journal of Cleaner Production, 14(9–11), 810–819. WWF Finland. (2011). Green office: Environmental management system for sustainable organisations–achievements and activities in 2010.

The Green Vision of Technical University of Crete’s Campus Nikolaos Sifakis, Efprepios Baradakis, Spyros Psychis and Theocharis Tsoutsos

Abstract The global interest in green universities is growing as they can be used as a replicable example not only for Universities but, also, for communities, in general. Technical University of Crete (TUC) was established in 1977, near the city of Chania. Alongside with the increased number of students, the energy needs of the university are keen on increasing, as well. Some actions had to be taken to avoid getting into a dead end regarding energy expenses and the total allocated budget for such needs. As an attempt, they represent a confident effort of academic communities toward a sustainable, decarbonized and greenified culture. The first attempt of the greenifying of TUC took place in 2013, when the council adjudicated some crucial decisions toward sustainability. Various actions were planned to be taken and the results of them are being presented into this chapter. The first encouraged results indicate a, about 20%, reduction in energy consumption and therefore a thorough analysis of the results has been conducted which can be used as a useful tool in order reveal the process for future actions toward sustainability and green development.

Abbreviations list LED Light-Emitting Diode LPG Liquefied Petroleum Gas TUC Technical University of Crete

N. Sifakis · E. Baradakis · S. Psychis · T. Tsoutsos (B) Renewable & Sustainable Energy Lab, School of Environmental Engineering, Technical University of Crete, 73100 Chania, Greece e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Z. Yaser (ed.), Green Engineering for Campus Sustainability, https://doi.org/10.1007/978-981-13-7260-5_3

19

20

N. Sifakis et al.

Table 1 Students number into 5-year periods (TUC and Digalakis 2013) 2000

2005

2010

2015

2018

Architectural Engineering Department

0

101

429

812

1,011

Electronics and Computer Engineering Department

390

713

904

1,326

1,632

Mineral Resources Engineering Department

311

471

573

822

971

Production Engineering and Management Department

504

762

932

1,307

1,572

Environmental Engineering Department

193

357

451

746

916

Total

1,398

2,404

3,289

5,013

6,102

1 Case Study of TUC—Preliminary Phase (Before) 2002–2012 Technical University of Crete (TUC) was established in 1977, in an area almost 7 km outside the city of Chania. The climate in Crete is temperate and the atmosphere can be quite humid, depending on the closeness to the sea. The winter is fairly mild and bearable. Snowfall is practically unknown to the plains but quite frequent in the mountains. During summer, average temperatures are in the high 30s–low 20s (Celsius). “Bad weather” days in winter are often interrupted, during January and the first fortnight of February, with sunny days, known as ‘Halcyon days’ since ancient times (Tsoutsos et al. 2018). During the academic year 1984–85, the Production Engineering and Management Department initiated the operation of its educational program and welcomed its first 120 students together with the Sciences Department. The Mineral Resources Engineering Department followed in the season 1987–88 and the Electronics and Computer Engineering Department in season 1990–91, as well. Later on, the Chemical Engineering Department was converted into Environmental Engineering Department; it admitted its first students in 1997. Finally, in 2004 the Architectural Engineering Department was established and welcomed its first students (TUC and Digalakis 2013). From the first admission of each faculty, the number of admitted students has been increased, resulting in yearly fluctuations. The total number of students for the period 2002–2018, for 5-year periods, for each faculty, is presented in Table 1. It is obvious that the number of students attaining each and every faculty of TUC is increasing steadily which practically means that its needs, not only regarding energy, are rocketing up, as well (Fig. 1). This is utilized in order to comprehend deeply that such needs are increasing yearly and that in the near future, it can lead to devastating results. It can be easily understood that the university has extremely high energy demands and as the number of students is rocketing, the number of professors and researchers will increase as well. The first attempt of greenifying TUC took place in 2013, when the council adjudicated some crucial decisions toward sustainability. The results of this attempt are demonstrated in Fig. 1, in which a 20% reduction

The Green Vision of Technical University of Crete’s Campus 6000

4.60 4.40

5000

4.20 4000

4.00 3.80

3000

3.60

2000

3.40

No of students

Energy ConsumpƟon [GWh]

21

1000

3.20 3.00

0

Year Energy ConsumpƟon

No of students

Fig. 1 The trend of number of TUC students and of energy consumption during 2002–2017

in energy consumption (in 2014, since 2012) is obvious while the total number of students has been increased by a little more than 25%. The energy needs of the university are increasing and, obviously, the operational energy costs of it are rocketing up. This can be easily understood from Fig. 1, where the annual energy consumption of the TUC facilities, is presented. The energy costs have been doubled by 2010 since 2002 and almost tripled by 2012, making the need for immediate actions mandatory, especially taking into account the increased number of students in the university by more than 1,500 students during the past 5 years and is projected to be increased by 1,000 more by 2020. These needs are growing annually, so the budget allocated to energy needs have reached tremendous high percentages. More specifically there are five blocks, of a total area of 58,815 m2 , into the campus that serve the needs of the university. These buildings were not created all together but each one individually. First and foremost, the main buildings (Block 5) were created in 1995 covering about 4,000 m2 and their energy needs are 232 kWh/m2 year. Block 5 consumes the most energy per m2 year as there are located at the network facilities of the university and covers the needs not only of the campus but of the students via the TUC@Home service, as well. In addition, there is the restaurant in the university which operates and serves students’ needs daily. Alongside, the building of Mineral Resources Department (Block 3) was created in 1995, covering 10,098 m2 ; their energy needs are reaching the 66 kWh/m2 year. After these, the facilities of Production Engineering and Management Department (Block 4) were established in 1997, covering 22,279 m2 where the annual energy consumption per square meter is 41 kWh/m2 year. Furthermore, the facilities of the Science Department (Block 1) were constructed, covering almost 14,000 m2 , which require 54 kWh/m2 year. Last but not least, the building which covers the needs of the Environmental Engineering and Architecture Engineering Departments was constructed into two phases, in 2004 and

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Fig. 2 TUC Campus blocks’ main characteristics

2013, respectively. These buildings cover about 8,500 m2 requiring 66 kWh/m2 year (Barth and Rieckmann 2012). The aforementioned can be observed in Fig. 2, in which there is a schematic depiction of the TUC campus and all the blocks constituting it. The energy needs of the whole University are very high and the funds that are allocated to these needs are, inevitably, extremely devastating if someone considers the total national budget allocated for TUC. These facts lead to a dead end for the University as the allocated budget for its laboratories, students and student care matters, is very low and inadequate. As for laboratories, their staff is not able to conduct proper research if they are not funded by external organizations and European Union programs. Furthermore, the majority of student care problems are hard to be fixed in a proper way and they remain half-fixed or not fixed at all, as there are insufficient funds to cover such needs.

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In 2013 TUC Senate decided to take actions toward energy conservation and sustainability in order not only to tackle energy poverty, climate change, but also to save annual expenses. There was a lot of effort by the TUC Community in order to examine the best techniques and technologies to face the problem. Last but not least, it was obligatory to discover both an efficient and applicable way to install and apply such technologies and techniques. It was an excellent opportunity to follow up with Green Universities’ concept and to invest into greener buildings, greener practices and products, and ways of engaging staff and students and had the prospect to produce principles of sustainability for current students and tomorrow’s engineers.

2 Vision TUC is coping to become a leading technical institute for the future and therefore, entered in the global effort for a future that is ecological, socially and economically sustainable within a local and global context (Barth and Rieckmann 2012). Energy consumption and poverty were among the main problems in the medium and longterm plans, because: • They lead to a financial impasse and takes advantage of valuable resources that could be directed to other needs (education, student care, etc.). • They cause an inhibition of the University’s growth prospects as the proportional increase in its size and its energy needs lead to an unsustainable and volatile situation that is virtually impossible to be maintained indefinitely. • They encourage misconduct of energy resources misuse and lack of interest. • They encumber the environment as it contributes decisively and negatively to the greenhouse gas emissions. So, the management authorities proceeded directly in the summer of 2013 to the elaboration of the strategic plan for sustainable development and to the design of concrete actions focusing on two main directions: (a) Collection of data regarding energy consumption The university started systematically to record and documentation the energy flows; there was a limited number of electric energy consumption points, one per case, at the 3 main groups of the TUC buildings (main campus, French buildings at Chania, old administration at Chania). (b) Interventions for energy saving The competent authorities focused on designing and implementing interventions in both medium and long-term targeting. Particular emphasis was placed on minimizing the use of fossil fuels and replacing the conventional boilers with heat pumps. The main goal of these actions was to manage to reduce the ecological footprint of the university to reduce the energy cost following the most efficient way, without

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diminishing the quality of its services. The actual mid-term reduction rate to be achieved was set to 20%. The plan provisioned action aimed towards the following: • • • •

Energy consumption reduction Water consumption reduction Paper usage reduction Recycling

TUC planned in a mid-term reduction by 20% of the energy consumption, with a long-term plan of a 60% energy consumption reduction. The first goal was achieved, as it can be seen in the results section, and this allows the responsible authorities to have faith that the long-term goal is realistic and achievable (TUC and Digalakis 2013).

3 Completed Actions The actions taken can be grouped into two main categories: (a) Monitoring systems and (b) Interventions regarding energy saving.

3.1 Monitoring Systems In the context of the recording and collection of the required data, the following were implemented: • Access to the telemetry data was enabled provided by the power supply company to medium-voltage consumers, as well as the web access to the e-bill service. In this way, the university had the opportunity to immediately monitor the monthly total consumption of electricity. • A web-based database of oil consumption-related receipts was created and the storage tanks were written down in order to enhance the transparency. In addition, there is undergoing a necessary update of the delivery system before the payment of the bills. • Eighteen (18) energy-metering telemetry devices were bought, implemented, and placed into crucial points of the campus. At the same time, easy-to-use software has been developed in order to record and analyze the data. • An energy map of the university was created showing in real time the energy consumption of the preferred points in the university. This is publically open to the visitors of the TUC official website. • The power consumption data of the TUC are open source (available to everyone) and can be used by research and study groups.

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• Energy-metering devices were installed into the rooms of the dormitory, enhancing and aiding the students’ attempt to reduce their energy consumption and be more environmentally aware. By combining the above measures, the TUC’s authorities were confident that they would manage to reduce energy consumption and achieve their mid-term goals. These techniques were still a step forward, and indicate the simple problems that have to be tackled first if energy poverty is to be avoided (TUC and Digalakis 2013).

3.2 Interventions Regarding Energy Saving The energy-saving interventions had not only short but mid-term targeting, aiming to achieve great improvements gradually and not at once. Special emphasis was paid into diminishing the oil-energy consumption and the replacement of the conventional boilers with innovative ones, such as heat pumps. • In collaboration with the laboratories of the university, changes were made into the time of operation of high power-consuming devices, in order to take the most advantage of the night, reduced, electricity rate. • Old conventional spotlights of extremely high consumption in public areas and sports facilities were replaced by innovative LED technology ones. • The boiler room of the dormitory of the campus was rebuilt and renovated, new water heaters and a new heat pump were installed for the optimal use of the solar thermal system. Furthermore, the hot-water recirculation systems were repaired and set to operate. • Modern air conditioners were installed in all rooms and public spaces of the dormitory, as well as controllers that incorporate metering and presence sensors to ensure the most efficient operation possible. • Thermo-interlocking aluminum frames with Low Thermal Emission Glass (Low E), were installed for the first time in the premises. • The old conventional air conditioners of all the buildings were replaced by modern (high energy class) ones. • The obsolete cooling unit of the Mineral Sources Department was replaced by a heat pump, which, contrary to the old one, can serve the heating needs of the building during the winter period, as well. • The diagnostic procedure of the replacement of the lightning pillars located into the campus, and new ones, based on magnetic induction technology, were implemented. • The operation of the central automation system of the air-conditioning units was restored, in collaboration with the Energy Management in the Built Environment Research Lab. • Posters and web banners were created to raise the energy awareness of the community and eliminate the waste of resources

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3.3 Undergoing Actions Several actions are planned to be executed in the near future, such as • Purchase and implementation of a solar thermal system in the campus’ restaurant for the supply of hot water. An oil-burning conventional boiler has been used until now. • Installation of controllers and energy meters in every office space using autonomous split-type air-conditioning systems. • Supply and installation of additional heat-shrinkable frames equipped with lowtemperature glass (Low E). • Gradual replacement of electrical kitchen utensils with LPG ones. • Replacement of old conventional lamps with energy-saving LED ones into interior places.

4 Results It is of high importance to underline the fact that the energy data of the TUC became available for anyone interested. It is a good initial point to start and perform research activities such as data analysis, modeling and therefore runs optimization algorithms in order to enhance the buildings and the end-users’ (staff, students, etc.) behavior toward sustainability. On the other hand, since there were not dynamic measures regarding the energy consumption of the campus facilities and the supply of the energy-metering telemetry devices was, practically, a huge step forward that can enable the optimization of the consumption schemes and diminish extreme and improvident energy use. The analysis of the data is operated by easy-to-use software that can be used to extract some secure and concrete conclusions. All the undertaken actions had an impact on the campus activities toward a greener manner and as a result, they have led to immediate results that can be taken seriously into account and permeate confidence for the future. These actions were not just some distinct energy policies that had to be applied but a common attempt, of the responsible authorities, to achieve their much desired, mandatory, energy goal and comply with European Commission’s guidelines regarding energy. By observing Table 2, someone can easily understand that these 4 actions had a remarkable impact on the energy savings of the university and especially the two first, as they indicate that something so simple can lead to huge energy savings. Following the same motive, the first action presented remarkable energy savings and the comfort of the users is improved, drastically, as well. First and foremost, the number of students was increased since 2012, but the same did not happen to the total energy consumption. The main reason for it was the aforementioned actions and the exact data for these two parameters are presented in Fig. 3.

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Table 2 Results of the most noteworthy actions a/a

Actions

Description

Basic factor of change in regard to energy saving

Energy savings

1

The diagnostic procedure of the replacement of the lightning pillars located into the campus, and new ones, based on magnetic induction technology, were implemented

Replacing 84 lamps (300 W each) of Metal Halide Quartz Technology with 95 W lamps of Magnetic Induction technology

The old design provides 25 lux luminance levels on the road according to the idea that as lighter as better. In the new design, we follow the EN13201 regulation that requires 8–10 lux luminance levels

69,140 kWh/yr

2

Old conventional spotlights floodlights of extremely high consumption in public areas and sports facilities were replaced by innovative LED technology ones

Replacing 54 lamps (1,000 W each) of Metal Halide Quartz Technology with 54 LED lamps 70 W

Also, the old design provides much higher luminance levels than actually, these facilities need. The hydrargyrum quartz iodide lamps degrade more rapidly by time in comparison with LED and magnetic induction technology

91.652 kWh/yr

3

Moving facilities from two Energy Intensive Buildings

The Rector Office, the Financial Facilities of the Campus and the Architecture Engineering Department was in the City of Chania a road distance about 12 km from university campus

On the point of Energy Savings, the Energy consumption of 2 extra IT servers with consumption 7.5 kW each for 24 h is avoided. Also, the oil consumption for the heating of the two buildings is avoided, as well

132.000 kWh only regarding the electricity consumption

4

Stop the operation of the administrative facilities with compulsory permits of leave in August

Permits of leave for each staff member of these facilities

High energy demand due to cooling systems in such period and the workload is relatively low

58.400 kWh/yr

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Energy consumpƟon per student [kWh/std]

1200

1,134

1100 1000

923

900 797 800

764

760

768

2015

2016

2017

700 600 500 400 2011

2012

2013

2014

2018

Year

Fig. 3 Yearly energy consumption per student

It would be extremely interesting to examine the energy consumption per students yearly, as it is a very useful indicator in order to prove the usefulness of the energysaving actions. The declining trend is being depicted in Fig. 3, in which there is a slight increase in the past year due to the extreme weather conditions and the increase of the newcomer students. The most significant reduction regarding energy consumption was regarding the oil expenses for heating. After the implementation of the heating-related actions (Sect. 3.2), there was a diminishing of oil-related expenses as almost all these systems were replaced with ones of different technology(heat pumps). The reduction of oil consumption energy equivalent as well as of total energy, are presented in Fig. 4. The mean energy consumption of the second period is less than the one of the first one by 1.19 GWh, which is an extremely high amount of energy (a little higher than the total energy consumption of a typical village of 500 inhabitants). The total reduction regarding energy consumption since 2012 is almost 20%, which can alleviate the university of a severe problem. The importance of this reduction can be depicted in a diagram, where the proportion of the energy expenses to the total budget of the university is presented (Fig. 6). The energy consumption of the university has fluctuations during 1-year period, which are strongly related to weather conditions and to laboratories’ operation. In Fig. 5, the total monthly energy consumption of the University’s campus during the past 5-year period is presented. It is observed that the consumption scheme is the same as the most energy-demanding month is February, except for 2012 where the action with the replacement of air-conditioning systems with heat pumps had not taken place yet. Furthermore, the results are surprisingly well as the line of each next year seem to be, in general terms(except for 2015, when there were no extreme weather

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Energy ConsumpƟon [MWh]

Fig. 4 Total yearly energy consumption incl. oil-energy equivalent 500 450 400 350 300 250 200 1

2

3

4

5

6

7

8

9

10

11

12

Month 2012

2013

2014

2015

2016

2017

Fig. 5 Monthly TUC campus energy consumption since 2012

conditions), lower than the previous one, meaning that the energy consumption is being reduced in each and every month and not because any other imponderable factor (Fig. 5). In order to evaluate our previous assumption, as seen in Fig. 5 energy saving in the same month of each year seems to be better than the previous year. There was an increase in 2017 consumptions due to the extremely cold winter and extremely hot summer this year in Crete. Due to the economic austerity, there were huge reductions in the state allocated a budget of TUC, which is being reduced further year by year. As seen in Fig. 6,

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Percentage of energy to total expenses

100 90 80 70 60 50 40 30 20 10 0

2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Year Total expenses

Energy expenses

Fig. 6 Percentage of energy expenses to total expenses Table 3 Yearly energy expenses per student

Year

Energy expenses per student [e/student]

2006

125.6

2007

164.2

2008

171.0

2009

160.7

2010

168.7

2011

149.5

2012

163.9

2013

138.4

2014

123.6

2015

114.7

2016

121.3

2017

115.1

although there are huge savings regarding energy consumption, it is not enough and further actions should be taken. It is heavy for the university to pay 20% of its budget to energy expenses reducing the allocated budget to other factors such as laboratories (equipment, staff, dormitories, etc.), students’ ultimately needs and amenities, renovation of existing facilities, etc. The results of the calculation of the annual energy cost per student are presented in Table 3 and Fig. 7.

Fig. 7 Energy expenses per student through the examined period

Energy expenses per student [€/student]

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180 170 160 150 140 130 120 110 100 2005

2010

2015

2020

Date

It is clear that the energy expenses per student have been reduced dramatically, by almost 30% which is a solid decrease and can enhance the sustainability and the ecological footprint of the University.

5 Discussion The global interest in green universities is growing as they can be used as a replicable example not only for universities but, also, for communities, in general. As an attempt, they represent a confident effort of academic communities toward a sustainable, decarbonized, and greenified culture (Ramos et al. 2015). On this way of manner, TUC community formulated a plan to greenify its campus toward a sustainable future. The actions referred to two main pillars, (a) monitoring systems and (b) interventions regarding energy savings, but during the interval time of their implementation, new actions have been recommended and are undergoing. Speaking about the initial results, there has been a reduction of almost 0.35 GWh regarding energy consumption only by implementing the four actions of Table 3. These measurements seem to be extremely simple and have a great impact on the university’s operations, both functional and economical. The total energy savings are calculated either in 1-year periods before and after periods, with the second ones to be more reliable as they describe a greater time period. The difference between the energy consumption during the two periods reaches the 1.20 GWh yearly or almost 21% less energy which is an extremely high proportion compared to the total energy consumption of the campus. Alongside with energy savings, the implemented actions and systems offer a great variety of advantages to the university as, according to the strategic plan, they provide a great database for researcher either inside the University or from affiliates. In addition, the existence of the power metering systems can offer a great bunch of details regarding the power consumption during different hours in a day, different periods of the year, etc. Furthermore, future actions and plans can be introduced as the required studies can be held easier due to these systems (Hasapis et al. 2017). For

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example, the university planned and have now initiated the process to install some new photovoltaic systems in order to produce 300 kWp of green power generation, although there is a limit on the inland produced the amount of energy, according to Greek law restrictions, because the island of Crete is still off-grid. Last but not least, bureaucracy in Greece and procurements are holding back this action and the university’s authorities do their best to overcome these obstacles and, implement the system, at last (Petidis et al. 2018). Additionally, the existence of a strategic plan into a university can be crucial for all its operations/functions as it aids the human resources of the campus to move collaboratively toward a common direction, which is the sustainable development and TUC green future. There is a common target for all the TUC schools and administration departments, making this goal reliable. A notable example, is the previously installed lighting installations in which there was the opinion that more light is better and more emphasis was paid on design. This, according to the new strategic plan toward sustainability, was changed and the lighting installations were replaced with new ones, in which the energy consumption and the comfort of the end-users, as well, were of major importance. Last but not least, the awareness of the faculty staff and the students was greatly increased. TUC was experiencing a lot of empty classrooms where the lights and the windows were left open and the conditioning system, as well. Another example was a 42 kW laboratory machine which produces liquid nitrogen, that was operating during peak hours (high electricity demand and therefore costs are high). At this time, this machine was scheduled to operate only on Saturdays which leads to significant energy savings, by only a machine. Taking into account that on the one hand, many of the above actions have been recently completed, but on the other hand, several of them are to be completed in the near future, reducing the energy consumption will continue. For example, only the routed replacement of lights bodies of perimeter road lighting are expected to save energy of their order 60 MWh per year. The university prepared a study to install the photovoltaic unit at the Technical University of Crete for self-consumption and energy saving. The study was successfully completed and competition notices were prepared for the installation of infrastructure. Last but not least, it is extremely important to mention that according to the national power supplier’s data, the average CO2 emission factor of its total power generation system, was 1.18 tnCO2 /MWh. Consequently, the benefits from the energy savings for these 2 years (2013 and 2014), are estimated to be around 1,300 tonnes of CO2 . As a result, approximately 350 tonnes of CO2 are estimated to be avoided just from the oil savings these 2 years. Apart from savings, it is crucial to implement the planned actions, related to the production of energy from photovoltaic systems, for two main reasons: (a) The favorable geographic position of the university allows the maximization of energy production of photovoltaic systems, increasing their actual performance,

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(b) The expected extremely important impact on the minimization of energy costs, which is going to lead to significant saving benefits, related to both energy and costs. All these can be easily proved, because photovoltaic systems are maximizing their power generation at the middle of the day, synchronized with the peak of demand in the university (rush hours). Since 2014 various attempts have been held by the two Cretan universities and finally in 2017, TUC got the state approval for implementing a 300 kWp photovoltaic system. Concluding, these and various more actions that can be implemented are extremely useful not only regarding the financial matter of the university but they are a solid move toward a sustainable, green future with a reduced, or even zero, environmental footprint. Acknowledgements The sole responsibility for the content of this paper lies with the authors.

References Barth, M., & Rieckmann, M. (2012). Academic staff development as a catalyst for curriculum change towards education for sustainable development: An output perspective. Journal of Cleaner Production, 26, 28–36. Hasapis, D., Savvakis, N., Tsoutsos, T., Kalaitzakis, K., Psychis, S., & Nikolaidis, N. P. (2017). Design of large scale prosuming in Universities: The solar energy vision of the TUC campus. Energy and Buildings, 141, 39–55. Petidis, I., Aryblia, M., Daras, T., & Tsoutsos, T. (2018). Energy saving and thermal comfort interventions based on occupants’ needs: A students’ residence building case. Energy and Buildings, 174, 347–364. Ramos, T. B., Caeiro, S., van Hoof, B., Lozano, R., Huisingh, D., & Ceulemans, K. (2015). Experiences from the implementation of sustainable development in higher education institutions: Environmental Management for Sustainable Universities. Journal of Cleaner Production, 106, 3–10. TUC, R. O. & Digalakis, V. (2013). TUC Rector’s office energy report. Tsoutsos, T., Tournaki, S., Frangou, M., & Tsitoura, M. (2018). Creating paradigms for nearly zero energy hotels in South Europe. AIMS Energy, 6(1), 1–18.

The Construction of Green Building Using Interlocking Brick System Abdul Karim Mirasa and Chee-Siang Chong

Abstract Campus sustainability intends to minimize the negative effects that impact on their resources, while fulfils the activities of the universities for assisting the society in transition as the sustainable lifestyles. Since the activities of universities require many structures and the construction projects inevitably cause unfriendly effects on the environment, this research aims to investigate the effectiveness of interlocking brick system in reducing the energy consumption. In this research, a single-storey building had been built-up to validate the sustainability of the interlocking brick in constructing the green campus. By implementing the reinforced concrete construction method, it has found that about 1356.28 kg cement is needed to construct the required beams and columns. The invented interlocking brick system has avoided the exhaustion of 1356.28 kg cement and thus, saved 5.425 GI energy depletion, reduced 1.35-ton greenhouse gases emission and eliminated the formwork consumption. Moreover, this system is also proved to be competent in taking the essential role as load-bearing system of a building.

1 Introduction Campus sustainability has drawn global attention, especially from the planners and policymaker of the university as perceiving the consequences that the activities of universities have bought on the environment (Alshuwaikhat and Abubakar 2008). According to Velazquez et al. (2006), a sustainable campus is defined as a whole or a part of higher education institution, which addresses, promotes and involves the actions of limiting the negative effects (in terms of environmental, economic, societal and health) that impacts their resources, while fulfil the activities of teaching, research, outreach, partnership and stewardship for assisting the society to transition as the sustainable lifestyles. Universities, which can be termed as “small cities”, generally require numerous building structures to carry out a wide range of teaching, A. K. Mirasa (B) · C.-S. Chong Faculty of Engineering, Universiti Malaysia Sabah, 88400 Kota Kinabalu, Sabah, Malaysia e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Z. Yaser (ed.), Green Engineering for Campus Sustainability, https://doi.org/10.1007/978-981-13-7260-5_4

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researching and industrial activities. Yet, the construction projects inevitably bring certain direct or indirect negative impact on the environment. In the construction industry, concrete, as one of the most versatile materials, require mainly the aggregate and cement paste (Chee et al. 2011). Thus, ordinary Portland Cement (OPC) is the major substance of the conventional construction industry. A large number of energy (1000 kg of cement needs 4 GI of energy) is consumed during the production process of cement, and this process also emits a great deal of CO2 (around 1 ton) together with other greenhouse gases (Mehta 2001, 2002). The conventional masonry brick is another significant construction material and produced by mixing the raw materials, moulding the mixture, drying and firing until it acquires the strength as brick. Similar to the cement production, the manufacture process of the fired bricks caused a huge depletion of resources and consume high energy that about 300% higher over those of the concrete blocks, therefore, this process causes the serious environmental degradation owing to the high emissions of greenhouse gas (Al-Fakih et al. 2019). In order to limit the environmentally unfriendly effects of the construction, the researchers have been stimulated to develop a new method for replacing these construction materials. Reinforced concrete construction (RCC) structure is the youngest structure if compared to the soil and timber structure (which appeared earliest on earth and constructed by the original mankind), the masonry structure (which constructs using stone or brick and commonly used in the early society of ancient civilization) and the steel and other metal structures (that invented after the Industrial Revolution) (Guo 2014). Yet nowadays, RCC structure has become the most used structure in modern and contemporary architecture of many countries due to its continuously improving performance, manufacture techniques, construction methods and a variety of application scope (Guo 2014 and Ling 2018). Contrary to RCC structure, the application scope of the masonry structure is very much narrow. Indeed, a load-bearing masonry structure is commonly designed as a vertical cantilever member for sustaining the permissible compressive and shear stress (without tension) with the principles of engineering mechanics. The transferring of moment from floor-to-wall connection is not allowed and the lateral force is assumed to be supported by the diaphragm action of the roof slab or the above floor that acts as a beam (Bureau of Indian Standard 1991). The load-carrying capacity of the masonry structure principally depends on its slenderness ratio. When the slenderness ratio rises, the crippling stress of the wall decreases due to the elastic instability. In general, the masonry structure may fail owing to the excessive stress or buckling effect (Bureau of Indian Standard 1991). In terms of masonry standard, the strength of conventional masonry wall basically depends on the strength of the mortar and the relative values of unit strength of brick and mortar strength (Ahmad et al. 2011). Since the interlocking brick wall is constructed with none or less mortar, the strength of interlocking brick wall can be improved. Furthermore, the interlocking mechanisms of the interlocking brick construction system highly enhance the continuing of the wall. Whereas, the grout, vertical and horizontal reinforcements that have been used to strengthen the wall also increase the buckling resistance of the interlocking brick. A detailed discussion

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related to the structural behaviour of the interlocking brick wall as a load-bearing member will be presented in another research paper prepared by the authors. Interlocking brick is a recently developed product that can be acted as a loadbearing system. Since interlocking brick system (IBS) is competent to support the structural members above it and their interlocking mechanism facilitates the mortarless technology, the utilization of interlocking brick system can significantly reduce the usage of cement and constructs the green building. In the year 2018, Al-Fakih et al. had reviewed the literature regarding interlocking bricks and concluded that the concept of interlocking system has been widely used and gradually replaced the conventional construction system. Fundi et al. (2018) ensured that the interlocking brick technology has encouraged the sustainable construction. They also conducted the static compressive testing towards the interlocking wall and found that the compressive strength of the wall can be enhanced by using the optimum stabilizers content to stabilize the laterite soil. In contrast to the structural behaviour of interlocking brick towards static load, the investigation regarding the impact behaviour of the plate-like assemblies made of interlocking bricks had been carried out with the drop weight experiment (Rezaee Javan et al. 2017) and the three dimensional finite element model (Rezaee Javan et al. 2018). Based on these researches, they concluded that the plate-like assembling, which constructed using the interlocking bricks, have significantly enhanced the flexural performances of the monolithic plate in terms of impact energy absorption (Rezaee Javan et al. 2017, 2018) Even though many laboratory testing or modelling analyses regarding the structural behaviour of interlocking brick have been carried out, the publication about the construction procedures using interlocking brick is still limited (Simion 2009). Mahmood et al. (2017) had compared the economic aspect of interlocking brick system with the conventional construction method of typical reinforced concrete construction (RCC). Yet, the reduction of concrete or cement usage as the construction carried out using interlocking brick system has not yet been studied. Thus, this chapter aims to clarify the reduction of the concrete (or cement) consumption when a single-storey building is constructed using the interlocking brick system. The first section of this chapter briefly introduces the fundamental concepts of the interlocking brick system. Then, the production method and the construction process using interlocking brick system are discussed correspondingly. In order to clearly study the sustainability of the interlocking brick in constructing the green campus, a single-storey building had been built-up and the reduction of cement usage is discussed.

2 The Interlocking Brick System For briefly introducing the fundamental concepts of the interlocking brick system, the first subsection of the following describes the basic theories of the interlocking bricks. Subsequently, the types of the interlocking brick and their usage are discussed. Lastly, the interlocking mechanism is explained.

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A. K. Mirasa and C.-S. Chong

2.1 Description of the Interlocking Brick As stated in BS 6073-1:1981, clause 3.12, brick is a masonry structure that has measurements less than 337.5 mm length, 225 mm width and 112.5 mm height. Any unit with a higher dimension of these afore-mentioned sides is known as block. Commonly, bricks can be produced from clay by using high firing method or by binding cement paste. While burnt or baked brick method has brought a lot of shortcomings to the environment, which is the greenhouse gas emission and consumption of high amount of energy, the interlocking brick of this research is innovated to reduce the usage of cement and eliminate the firing procedure. Interlocking brick system has adopted soil as a major raw material. Morris and Booysen (2000) had emphasized that the utilization of soil that is a commonly available resource for construction has facilitated the appropriate and sustainable technology for the built environment and the advantageous bring across the economic spectrum and a wide variety of social or technology development. With the hydrometer tests, the utilized soil of this research is classified as clayey soil. As stated by Walker (1995), the plasticity index of the most ideal soil for producing the cement soil brick is within the range of 5–15, whereas soils have plasticity index larger than 20–25 are not appropriate to cement stabilization with manual pressing owing to the problems of low compressive strength, excessive drying shrinkage and inadequate durability. In general, the plasticity index of the utilized soil of this research has always been examined and to ensure the soil has the acceptable plasticity index. According to ASTM C129, the minimum required unit compressive strength of brick is 2.5 N/mm2 . By conducting the experimental test, it has found that the unit compressive strength of the produced interlocking brick is broadly above 5 N/mm2 . Based on the research investigation of Jayasinghe (2007), the required design compressive stress of the wall for constructing a 5.0 m high wall to sustain 0.12 N/mm2 roof load is 1.4 N/mm2 . The compressive strength of the constructed interlocking brick walls in this research has satisfied this required strength. Moreover, the wet strength of this produced interlocking brick has been examined. With reference to New Mexico Earthen Building Material code, the Australian Standard and the New Zealand Standard, the wet strength of the brick should be higher than half of its dry strength. The obtained wet strength results of this interlocking brick have fulfilled these standards. As a conclusion, the structural behaviour of the innovated interlocking brick construction system has been assessed and the results are satisfactory. Thus, this interlocking brick construction system is apt and competent to be a load-carrying member of a building. The interlocking brick, which is used to construct the green building in this research, is demonstrated in Fig. 1. Basically, the alignment of the wall system can be formed in terms of the faces of the brick. As illustrated in Fig. 1, these faces can be termed as end faces (header), top face, bottom face, stretcher (front face) and back face.

The Construction of Green Building … Top face

39 End face (Header)

Stretcher (Front face) Bottom face

End face (Header)

Stretcher (Front face)

Back face

Fig. 1 The specification regarding the sides of the interlocking brick

2.2 Types of the Interlocking Brick and Their Usage In order to construct a building using the interlocking brick system, three common shapes of interlocking brick are invented. Figure 2 has described the standard interlocking brick, the U-shaped interlocking brick and the half interlocking brick. For achieving the interlocking mechanism of the interlocking brick system, half interlocking brick and standard interlocking brick are the major constituents of the wall system. Since the interlocking brick system aims to eliminate or reduce the usage of reinforced concrete structural members, U-shaped interlocking brick is produced to act as the supporting element of the wall system. The empty portion of the U-shaped interlocking brick intends to be reinforced with the steel bar and the pouring of the binding grout able to strengthen its loading capacity. Thus, U-shaped interlocking brick normally laying at the bottom of the interlocking brick system, above the door or window and the top of the wall to support the above structural members.

a) Standard Interlocking Brick

b) U-shape Interlocking Brick Fig. 2 The types of the interlocking brick

c) Half Interlocking Brick

40

A. K. Mirasa and C.-S. Chong

2.3 The Interlocking Mechanism A wall is known as a vertical structure where its length and height are far larger than its thickness. Through the conventional mortared-brick techniques, the wall construction stages broadly involve bricklaying, jointing and plastering process. When the conventional bricks are used to construct the wall, mortar is applied around the headers and the top face of each brick to joint with bricks beside and above it. For the interlocking brick system, the mortar layers or plastering on both sides of the bricks are eliminated. Indeed, the specially designed shapes or forms of interlocking bricks enable the interlocking mechanism establishing among the bricks. By implementing this locking bond, the stability (horizontal and vertical alignment) of the constructed interlocking brick system is enhanced (Fundi et al. 2018). The loads that act on the interlocking brick system are transmitted from a brick directly to others and do not across the intermediate mortar layers. Moreover, each face of interlocking brick restrains the out-of-plane displacement both along and normal to the wall (Rezaee Javan et al. 2018). In short, the interlocking mechanism of the interlocking brick system not only reduces the usage of joining mortar, but also enhance the structural behaviour of the interlocking brick wall.

3 The Production Method of the Interlocking Brick In general, the interlocking brick is manufactured by first identifying the soil types with the respective testing. After the essential characteristics of the soil are examined, the soil extraction which includes excavation, sieving or pulverizing and preparations that covers drying and crushing are carried out. Subsequently, the raw material of the interlocking bricks, which consist of soil, fine aggregate, cement and water, are mixed with manual, machine, pressing or any other methods. Hereafter, the mixture is compressed in a mould by using manual or hydraulic press. Compaction ratio is defined as the ratio of the height of the brick mould (before the compaction) to the height of the completed compressed brick. Bahar et al. (2004) have suggested that the compaction ratios exceeding 1.65 are capable to produce brick with good strength. In this research, the compaction ratio of the compactor by the hydraulic press is about 1.7. Then, the manufacturing process of bricks is completed and the curing process should be carried on for 14 days. Within the first 7 days, the manufactured bricks are watered every day during morning, afternoon and evening (three times per day). Thence, the bricks are moved to an open space to dry naturally during the 8th–14th day. Figure 3 has summarized this production method of the interlocking bricks. Interlocking bricks usually are fabricated in the form of solid, perforated or hollow. The distinction between perforated and hollow bricks is divided based on the surface area of the brick holes. As the surface area of the holes occupies less than 25%, the bricks are classified as perforated bricks. For producing the solid interlocking bricks,

The Construction of Green Building …

Soil Identification Mixing Process (Soil, Sand, Cement and Water)

41

Soil Preparation (Drying and Crushing)

Characteristic Testing Moulding (with the compactor)

Curing Process - Watering every day th (Day 1 to 7 ) - Naturally dried th th (Day 8 to 14 day)

Fig. 3 The general concept for producing the interlocking brick

Crushing Machine

Compacting Machine

Mixing Machine

Fig. 4 The manufacturing process of the interlocking bricks

additional material and more power is required for pressing the mixture to form the solid brick with enough density. Yet, lesser cement binder is used for attaining enough strength of the solid brick. Nevertheless, more cement binder is needed in the mixture of hollow interlocking bricks for earning its satisfactory strength (Simion 2009). Until recently, the researchers and engineers have innovated several interlocking brick manufacture machine types, which comprise of manually operated, electric operated, hydraulic, automatic, semi-automatic, etc. Figure 4 demonstrates the manufacture machine of this research. This machine can be broadly divided into three major parts, which are the crushing machine, the mixing machine and the compacting machine. Two long runways are designed to connect these three machine parts.

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A. K. Mirasa and C.-S. Chong

As a summary of the manufacture process of this research, after the dry soil is well grounded with the crushing machine, the fine soil is transferred into the mixing machine for mixing together with cement, sand and water. Lastly, these mixtures are delivered into the compacting machine, which is operated with the hydraulic jack, to apply compression force up to 2500 lb per square inch for moulding as the interlocking bricks. The moulds are fabricated with different shapes to cast the interlocking bricks of varied shapes that are described previously in Sect. 2.2. Though the operation concepts of them are the same.

4 The Construction Process Using the Interlocking Brick System Overall, the construction process using the interlocking brick system is similar to those of conventional reinforced concrete construction (RCC). The major differences between them are the elimination of the timber formwork and the concreting regarding the supporting structural element, i.e. beam and column. Both of these constructions are initiated with the earthwork or land cleaning process and followed by the foundation constructions. Once the foundation and slab of the building are built, the placement of U-shaped interlocking brick along the wall is conducted for supporting the interlocking brick wall system. Successively, the interlocking brick walls are built-in and the PVC pipe is implemented along the wall for installing the electrical conduit. Lastly, the roofing installation is carried out above the interlocking brick system. Figure 5 briefly describes the construction process of the building using the interlocking brick system. For erecting the wall with the interlocking brick system, the interlocking bricks are built in the following process. First, the bricklaying process that aligns and levels the related bricks in the wall position. Thereafter, the pointing process ensures these bricks having the proper interlocking feature with the nearby brick to establish the stable, vertically levelling and aligned wall system. The interlocking brick wall is strengthened with reinforced steel bar that embeds into the system every 1 m span. After every five–seven layers of interlocking bricks are built-in, the grout of cement, sand and water is poured through the vertical holes. Thus, the interlocking brick wall has an adequate load-carrying capacity to act as a load-bearing wall.

5 Green Building Construction In order to prove the effectiveness of the interlocking brick system in reducing the cement usage, the necessary load-bearing structural members of the conventional reinforced concrete construction method, i.e. beam and column are designed and the required cement is computed in Sect. 5.1. A single-storey building with three

The Construction of Green Building …

Earth Work and Land Cleaning

Wall Construction (Every 5-7 layers) Placement of vertical reinforcement bars

Roofing Installation (after completion of Interlocking Brick Wall System)

43

Foundation Construction

Placement of U-shape Interlocking brick (For supporting the Interlocking Brick Wall)

Strengthening (Pouring the grout for strengthening the wall system)

Electrical Conduit Installation - Implementing PVC pipe

Finishing

Fig. 5 The general concept for constructing a building using interlocking brick system

bedrooms, a dining room, a kitchen, a lounge, a bathroom and a water closet had been built-up for validating the feasibility of the interlocking brick system in acting as a load-bearing system. This construction is explained in Sect. 5.2.

5.1 Conventional Construct Method By implementing the conventional construction method, the reinforced concrete structural members, i.e. beam and column are the most essential load-bearing members that support the whole building. Figure 6 presents the common design drawing plan of the one-storey house. The total area of the proposed building is about 57.156 m2 (7750 mm wide and 7375 mm long). Based on the conventional reinforced concrete construction method, the locations of beam and column for sustaining the building for residential purpose are designed and shown in Fig. 6. As a brief description, a total of 14 units of column and 19 units of beams with different dimensions, which have been listed in Table 1, is required to be constructed for supporting the proposed building with conventional reinforced concrete construction method. In reference to BS 8110-1:1997, Sect. 3, Fig. 3.2, the minimum widths of beam and column (with fully exposed condition) for the fire resistance are 200 mm. Since the design of the structural members is dependent on the intuition and experience of the engineers, it is not possible to figure out the exact amount of concrete and cement required by different engineers. Thus, this study only chose the minimum dimensions of beam and column, which are about 200 mm × 200 mm (column) and

44

A. K. Mirasa and C.-S. Chong

All Dimensions are in mm.

Plan Legend: Column A Single Storey House

Beam

Fig. 6 The manufacturing process of the interlocking bricks Table 1 The required amount of concrete in the conventional construction system

Dimension (mm)

Unit

Total required concrete (m3 )

Column

200 × 200 × 2800

14

1.568

Beam

200 × 150 × 2500

3

0.225

Beam

200 × 150 × 2625

8

0.63

Beam

200 × 150 × 4000

4

0.48

Beam

200 × 150 × 3375

4

0.405

Total

3.308

200 mm width × 150 mm depth (beam), for computing the required concrete in the construction project. Generally, grade 35 concrete is the commonly used concrete for the residential building. Even though some may use a higher grade for higher and more exposure building or a lower grade for smaller and well cover booth, grade 35 concrete is acceptable. For calculating the required cement quantity, Table 2 has listed the concrete mix design form to clearly clarify the procedure of the calculation. Based on Table 2, the required contents of water, cement, fine aggregate and coarse aggregate for mixing grade 35 concrete are shown in detail. By referring to Table 1, the total concrete required in constructing the required columns and beams is about 3.308 m3 . In terms of these data, the quantity of cement that needed to be prepared for constructing the conventional load-bearing system is computed as listed in Table 3.

The Construction of Green Building …

45

Table 2 Concrete mix design form of grade 35 concrete Stage Item

Reference

Values

1

Specified

35 N/mm2 at 28 days

BS 5328, BS 8110

5 % defective level for the design and construction of concrete structure

1.2 Standard deviation

Figure 3

8 N/mm2 (less than 20 results are available)

1.3 Margin

Figure 1

5 % defectives, k = 1.64 1.64 × 8 = 13.12 N/mm2

1.1 Characteristic strength

35 + 13.12 = 48.12 N/mm2

1.4 Target mean strength 1.5 Cement strength class

Specified

1.6 Aggregate type: coarse Aggregate type: fine

2

Crushed or Uncrushed Crushed or Uncrushed

1.7 Free-water/cement ratio

Table 2, Fig. 4

0.51

1.8 Maximum free-water/cement ratio

BS 8110, Table 3.3

0.60

– Use the lower value of free-water/cement ratio

0.51

2.1 Slump or Vebe time

Slump 30 – 60 mm

2.2 Maximum Aggregate size 2.3 Free-water content 3

42.5 or 52.5

Crushed – 20 mm Table 3

210 kg/m3 210/0.51 = 411.764 kg/m3

3.1 Cement content 3.2 Maximum cement content

4

3.3 Minimum cement content

300 kg/m3

– Cement content

411.764 kg/m3

4.1Relative density of aggregate (SSD)

2.7 known

4.2 Concrete density

5

Figure 5

2400 kg/m3

4.3 Total aggregate content

2400 – 411.764 – 210 = 1778.236 kg/m3

5.1 Grading of fine aggregate

Percentage passing 600 µm sieve = 65 %

5.2 Proportion of fine aggregate

Figure 6

33 %

5.3 Fine aggregate content

33% x 1778.236 = 586.818 kg/m3

5.4 Coarse aggregate content

1778.236 – 586.818 = 1191.418 kg/m3

46

A. K. Mirasa and C.-S. Chong

Table 3 The required cement based on mix design concrete G35 Quantities of concrete

Cement (kg)

Water (kg or litres)

Fine aggregate (kg)

Coarse aggregate −20 mm (kg)

per m3 (to nearest 5 kg)

410

210

585

1190

per trial mix of (3.308 m3 )

1356.28

694.68

1935.18

3936.52

5.2 The Construction Method of Interlocking Brick System For demonstrating evidently about the achievability of the interlocking brick construction system in supporting the building, Fig. 7 is presented. As clearly shown from the figure, only the interlocking bricks are constructed to support the roofing system of the building. This constructed one-storey building is termed as green building due to the fact that it not only reduces about 1356.28 kg consumption of cement, but also eliminates the requirement of formwork usage, which is fabricated with timber and necessary for casting the reinforced concrete beam and column. As stated previously, the production process of 1000 kg cement consumes about 4 GI energy and emits around 1 ton CO2 and other greenhouse gases (Mehta 2001, 2002), this green building has saved about 5.425 GI energy and reduce around 1.35 ton CO2 and other greenhouse gases emission. According to Bahaudin et al. (2014), there is a lack of standard criteria for rating or assessing the green buildings. Most of the countries have their rating system for green building. In Malaysia, more than one rating tool has been established by various organisations, which include of those developed by the Malaysian Institute of Architects (PAM), Malaysian Construction Industry Development Board (CIDB) and Malaysian Public Works Department (JKR). Green Building Index (GBI) is a rating tool of green building that has been developed by Malaysian Institute of Architects (PAM) in 2008, which has stated that a green building focusses on increasing the efficiency of resource use (energy, water and materials) while reducing building impact on human health and the environment during the building’s life cycle, through better sitting, design, construction, operation, maintenance and removal. In short, the green building shall be designed, constructed and operated for decreasing the negative impact to the environment. World Green Building Council (WGBC), as an alliance between 80 national Green Building Councils worldwide, is the largest international organisations that have led the green building market places. WGBC emphasizes that any building can be a green building provided it include the features regarding the efficient use of resources, reduction of the pollution, consideration of the environment in design, construction and operation, etc. This alliance has also addressed two essential global issues, which are the climate change and CO2 emissions (Bahaudin et al. 2014).

The Construction of Green Building …

47

The Interlocking Brick Construction System

U-shape Interlocking brick

Interlocking brick (standard)

Half Interlocking brick

Green Building Constructed with Interlocking Brick Construction System Fig. 7 The manufacturing process of the interlocking bricks

From the previous sections of this paper, it can be clearly noticed that a total of 5.425 GI energy have been saved and 1.35 ton CO2 and other greenhouse gases emission has been reduced by constructed this one-storey (built-up area 57.156 m2 ) housing using the interlocking brick system if compared to construct it with the conventional RCC structural members. Since the built-up housing of this research has the characteristics related to the efficient use of resources and reduce the pollution effect in the construction process, it certainly can be termed as a green building. Moreover, this interlocking brick is fabricated mostly with the natural resource (soil) and only compressed with the hydraulic press (which has eliminated the fire process), these also contribute the green building characteristic to the interlocking

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brick construction system. Besides, the construction of this green building spent only 2 weeks as the interlocking brick system can immediately support the roofing system. This is different from the reinforced concrete structural members that require setting time for attaining strength. Therefore, the conventional reinforced concrete construction system needs a longer period to complete a construction project.

6 Conclusions In this chapter, the basic concepts about campus sustainability, conventional construction industry, research of the interlocking brick and the insufficiency of the studied topics for interlocking brick construction system are briefly reviewed. Subsequently, the descriptions regarding the interlocking brick system are presented. The production method and construction process of the system is also introduced accordingly. For verifying the feasibility of the interlocking brick system as the load-bearing structural member, a single-storey house had been built-up. This research had investigated the required amount of beam and column (according to the design of the proposed house) by using the conventional reinforced concrete construction method. It was found that about 1356.28 kg cement is needed to construct the proposed building. Based on the previous finding of the afore-mentioned researchers, the production of 1356.28 kg cement requires about 5.425 GI energy and emits around 1.35 ton CO2 and other greenhouse gases. Since the innovated interlocking brick system had reduced the consumption of 1356.28 kg cement, it had saved about 5.425 GI energy and reduced emission of 1.35 ton CO2 and other greenhouse gases. Moreover, the elimination of formwork in the interlocking brick system also reduces the depletion of timber. As WGBC has addressed the imperative to reduce the CO2 emissions and the main objective of the green building based on GBI is to efficiently use the resource while reducing the pollution of construction to the environment, these data have validated the competency of interlocking brick system in constructing the green building. Conclusively, the interlocking brick system is proved as competent to build out the green building, which is environmental-friendly and able to fulfil the need of the campus for conducting its necessary activities. Acknowledgements The authors wish to express the appreciation to the financial assistance from the Ministry of Higher Education (KPT) Malaysia under Translational Research Program, Grant no. LRGS0008-2017. Sincere gratitude is also extended to all the members of Faculty of Engineering, Universiti Malaysia Sabah and School of Civil Engineering, Universiti Teknologi Malaysia who had contributed their efforts in the construction projects of this research.

References Ahmad, Z., Othman, S. Z., Yunus, M. B., & Mohamed, A. (2011). International Journal of Civil and Environmental Engineering, 5(12), 804–810. Al-Fakih, A., Mohammed, B. S., Nuruddin, F., & Nikbakht, E. (2018) IOP Conference Series: Earth and Environmental Science (Vol. 140, pp. 1–7).

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Al-Fakih, A., Mohammed, B. S., Liew, M. S., & Nikbakht, E. (2019). Journal of Buidling Engineering, 21, 37–54. Alshuwaikhat, H. M., & Abubakar, I. (2008). Journal of Cleaner Production, 16, 1777–1785. Bahar, R., Benazzoung, M., & Kenai, S. (2004). Cement & Concrete Composites, 26, 811–820. Bahaudin, A. Y., Elias, E. M., & Saifudin, A. M. (2014). A comparison of the green building’s criteria. In E3S Web of Conferences (Vol. 3, pp. 01015 1–10). BS 6073-1:1981. Precase concrete masonry units—Part 1: Specification for precast concrete masonry units. BS 8110-1:1997. Structural use of concrete, Part 1. BS 5328-2:1997. Concrete, methods for specifying concrete mixes. Bureau of Indian Standard. (1991). Handbook on mosonry design and construction. Chee, S. C., Hidayati, A., Paramasivam, S. K., & Mannan, M. A. (2011). Optimasation of concrete mix design using sandstone reactive aggregate in Sabah. Malaysia Construction Research Journal, 9, 50–64. Fundi, S. I., Kaluli, J. W., & Kinuthia, J. (2018) Construction and Building Materials, 171, 75–82. Guo, Z. (2014). Principles of reinforced concrete. Jayasinghe, C. (2007). Journal of Institute of Engineers, Sri Lanka, 2, 33–40. Ling, L. (2018). Journal of Nanoelectronics and Optoelectronics, 13(4), 572–577. Mahmood, M. T., Saggaff, A., Ngian, S. P., & Sulaiman, A. (2017) In Proceedings of the 3rd International Conference on Construction and Building Engineering (Vol. 1903, pp. 0700181–070018-5). Mehta, P. K. (2001). Reducing the environmental impact of concrete. Concrete International, 23, 61–66. Mehta, P. K. (2002). Concrete International, 24, 23–28. Morris, J., & Boosysen, Q. (2000). Earth construction in Africa. In Proceedings: Strategies for a Sustainable Built Environment. Rezaee Javan, A., Seifi, H., Xu, S., Ruan, D., & Xie, Y. M. (2017). Materials and Design, 134, 361–373. Rezaee Javan, A., Seifi, H., Xu, S., Lin, X., & Xie, Y. M. (2018). International Journal of Impact Engineering, 116, 79–93. Simion, H. K. (2009). PhD Thesis of University of Warwick. Velazquez, L., Munguia, N., Platt, A., & Taddei, J. (2006). Journal of Cleaner Production, 14, 810–819. Walker, P. J. (1995). Cement & Concrete Composites, 17, 301–310.

The Feasibility of Using Palm Oil Ash in the Mix Design of Interlocking Compressed Brick Hidayati Asrah, Nadiah Sabana, Abdul Karim Mirasa, Nurmin Bolong and Lim Chung Han

Abstract The conventional clay bricks, which are used mainly for the masonry wall construction, are suffering from the increase of energy price as well as environmental problems due to soil excavation and high carbon dioxide emission. The use of green interlocking compressed brick (ICB) containing palm oil fuel ash (POFA) may be the solution for these problems. However, the mix design of ICB containing POFA is not well established. This paper reports on the feasibility of using POFA in the mix design of compressed brick for the ICB production. The mixes were formulated using two different sizes of POFA, which were the ultrafine and unground POFA, and combined with the cement and sand. The results demonstrated that the compressive strength test and water absorption test satisfied the minimum limit specified for the clay masonry unit. The maximum compressive strength of 39.2 MPa was obtained with UF-10 at 24 days curing. Increasing the amount of ultrafine POFA to 40% decreases the strength to 19.26 MPa. The utilization of ultrafine POFA into bricks has produced bricks with good engineering properties compared to the unground POFA brick. Nevertheless, these results indicate significant potential of using POFA in the production of ICB for use in building construction. Application of POFA in the ICB production will help to reduce the energy consumption of the conventional clay brick firing process and reduce the environmental damages associated with the greenhouse gas emission. Keywords Interlocking compressed brick · Green building · Palm oil fuel ash · Ultrafine POFA · Compressive strength · Water absorption

1 Introduction The construction industry in Malaysia integrates a variety type of construction materials. The common types such as concrete and brick have long been used to construct buildings and infrastructures. Concrete is usually used to construct the main structural parts of the building, such as column and beam. Meanwhile, bricks H. Asrah (B) · N. Sabana · A. K. Mirasa · N. Bolong · L. C. Han Civil Engineering Program, Faculty of Engineering, Universiti Malaysia Sabah, Kota Kinabalu 88400, Sabah, Malaysia e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Z. Yaser (ed.), Green Engineering for Campus Sustainability, https://doi.org/10.1007/978-981-13-7260-5_5

51

52

H. Asrah et al.

are used in the construction of wall and partition of the buildings. With the increase in the urbanization and population growth, the demand on building infrastructures for both materials has rapidly increased. However, the crucial problems with the industry are, however, the impact of the materials on the environment. The production of clay brick may lead to environmental damages due to soil excavation and requires high construction cost, meanwhile concrete requires cement, which has a high carbon footprint. As cement is used as a binding element for both concrete and brick in construction, this has also stimulated the growth of the demand for cement. However, the cement manufacturing process consumes high energy, which is about 12–15% of the total energy consumption (Madlool et al. 2011). In addition, the calcination process releases high amount of carbon dioxide, which triggered climate change problem. On the other hand, the conventional clay brick, which is produced through the firing method has also used high energy and released carbon dioxides (Oti and Kinuthia 2018). As the need for housing increase, our responsibility for the environmental impact should not be left behind. Hence, choosing green building materials is possibly the best key to reduce the environmental impact due to construction. Implementation of the green concept in construction through reduction of greenhouse emission, reduction of natural resources consumption and using of waste materials in construction has been done in Universiti Malaysia Sabah (UMS). This is through the production of interlocking compressed brick (ICB), which meets all three requirements for the brick to be considered as green construction product. The interlocking bricks are different from the conventional earth bricks as it requires no mortar or concrete for the brickwork. This brick is joined with one another by methods of tongue and groove on the top and base of the bricks, which prevent the lateral movement of the brick (Malavika et al. 2017) (Fig. 1). Unlike conventional clay brick, this interlocking brick is produced through the compression method, using the semi-mechanized stationary-type machine. Hence, the production itself does not lead to the environmental destruction. Production of the interlocking compressed brick required moderate to low skilled worker since the ICB manufacture is very simple. It only takes three (3) main stages

Fig. 1 Interlocking compressed soil brick

The Feasibility of Using Palm Oil Ash …

53

Fig. 2 Production of interlocking compressed brick a Soil preparation and mixing, b Compression, c Curing

in the production process which are: soil preparation and mixing, compression and curing (Fig. 2). To increase the green application in ICB, the commonly used material, which is laterite clay soil can be replaced by waste materials from other industrial processes, such as the palm oil fuel ash (POFA). This may reduce reliance on the quarrying material from the natural sources and disposal of the waste to landfills. However, information on the effect of POFA as a soil replacement in the ICB production is very limited. Hence, to assess the suitability of POFA as material in the ICB production, a preliminary investigation has been conducted to study the mixture design of ICB with POFA replacing 100% of the clay soil using the compressed brick samples. This includes determination on the engineering properties of the compressed brick containing unground and ultrafine POFA, such as the compressive strength, density, and water absorption of the brick. Palm oil fuel ash (POFA) is a waste material from the palm oil production mill. The production of POFA waste starts with the extraction of palm oil from the fruit and copra of the palm oil tree. After the oil extraction process, waste products such as palm oil fibres and shells are used as biomass fuel and burnt at a temperature of 200–500 °C to boil water, which generates steam for electricity and the extraction process in palm oil mills. Generally, after combustion, about 5% of POFA by weight of the solid wastes is produced (Sata et al. 2004). In practice, POFA produced in the Malaysian Palm Oil mills are usually dumped in the plantation mill area (Sumadi and Hussin 1995). Hence, this has created many environmental problems due to improper POFA disposal. Studies have found that ground POFA is a good pozzolanic material. It contains high silica content and can be used to replace some amount of cement in the mixture of concrete, mortar, brick and many other construction materials (Aldahdooh et al. 2014; Kroehong et al. 2011). The silica content in POFA can react with the calcium hydroxide (CH) from the cement hydration process and produces extra calcium

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silicate hydrate (CSH) gel compound for strength development process (Karim et al. 2011). Instead of having pozzolanic properties, POFA also acts as microfiller to fill voids within the concrete microstructure when ground to a finer size (Asrah et al. 2015). In raw condition, unground POFA usually has larger sizes and known as porous material. However, ultrafine POFA has better quality and produced concrete with higher engineering properties compared to the unground POFA when used as cement replacement. These properties have improved the role of POFA in making strong and durable construction materials.

2 Materials and Methods The materials used in this study include the Ordinary Portland Cement (OPC), river sand, clay soil, water and POFA. The clay soil was extracted from UMS site area and used to produce the control brick samples. Meanwhile, POFA was collected from Lumadan Palm Oil Mill in Beaufort, Sabah. The river sand has a specific gravity of 2.72, which 90% passing through the 600 µm sieve. Two (2) types of POFA were used in this research; the unground POFA and ultrafine POFA. Table 1 shows the mix proportions of the compressed brick samples using unground and ultrafine POFA at various amounts. The water to POFA and cement ratio is fixed at 0.25. In the compressed brick sample production, the prescribed quantity of POFA and cement were mixed thoroughly, and water was added gradually until the mixture is consistent in colour. The mixture was then poured into 50 × 50 × 50 mm moulds and compressed using the compression machine at 43 kN pressure. The sample was demoulded and left for 24 h with cover to prevent from evaporation. The curing was only commenced on the second day after casting by sprinkling of water for 12 and 24 days.

Table 1 Mix proportion for compressed brick

Mix

Cement (g)

Sand (g)

POFA (g) (Soil)a

Control

250

125

(750)a

UF-10

250

125

250

UF-20

250

125

500

UF-30

250

125

750

UF-40

250

125

1000

UG-10

250

125

250

UG-20

250

125

500

UG-30

250

125

750

UG-40

250

125

1000

a Note:

UF–ultrafine POFA UG–unground POFA

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3 Properties of the Compressed POFA Brick (i) Compressive Strength of Compressed POFA Brick The compressive strength results shown in Fig. 3 indicate that compressed bricks containing ultrafine POFA have higher strength compared to the control and unground POFA brick samples. The highest strength was shown by UF-10 with 30.4 MPa and 32.9 MPa at 12 and 24 days, respectively. Meanwhile, all compressed bricks containing unground POFA tend to show lower strength at all ages of curing, except UG-10 (25.92 MPa) and UG-20 (12.74 MPa), which showed higher strength than the control sample (11.66 MPa) at 24 days curing. The lowest strength was observed in UG-40 with 7.7 MPa (12 days) and 8.2 MPa (24 days). The ultrafine POFA used in this research resulting in an excellent pozzolanic reaction, thus producing a good compressive strength in brick. Meanwhile, the compressive strength of compressed unground POFA brick reduced due to large particles of unground POFA with high porosity. The strength development observed in the compressed POFA brick occurs due to the hydration and pozzolanic reaction process. The hydration reaction occurs within the brick specimen forms the calcium hydroxide (CH) and calcium silicate hydrate (CSH), which able to bind the materials together for strength development. Meanwhile, the pozzolanic reaction between silica from POFA and CH leads to the formation of extra CSH. When POFA is ground to finer size, the pozzolanic reaction increases due to more reaction sites for the reaction to occur, resulting increment in the quantity of CSH (Sinsiri et al. 2012). With high CSH, binding of particles is more effective. Increase in the CSH gel also reduces the voids content, which makes

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12d

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Fig. 3 Compressive strength of compressed POFA bricks at 12 and 24 days curing

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the brick denser and may contribute for better strength development compared to unground POFA brick. It was also noticed that the compressive strength of both compressed unground and ultrafine POFA brick samples decreased with the increasing amount of POFA. The likely factor in the reduction of strength for the brick at high POFA content is possibly due to the lower amount of calcium silicate hydrate (CSH) formed. Since POFA is categorized as a pozzolanic material, the strength gain of the resulting brick is dependent on the reaction of silica (from POFA) with cement hydration (CH) to form CSH. However, at high amount of POFA, there may be an insufficient amount of CH formed from the cement hydration to react with the silica (Mo et al. 2017). Hence, it limits the amount of CSH produced and resulted in lower strength of brick. Nevertheless, both compressed unground and ultrafine POFA brick samples, and control brick produced in this research have exceeded and satisfied the minimum limits of 5 MPa as defined by BS 3921:1985. On the other hand, MS 76:1972 specifies that the minimum strength required to produce load bearing brick is 7 MPa. Therefore, all compressed brick samples produced in this research can be classified as load bearing brick ranging from Class 1–Class 5. These results also indicated that POFA has significant potential to be used as materials in the ICB production, especially when it is crushed to ultrafine size. (ii) Density Test As illustrated in Fig. 4, the densities of compressed ultrafine POFA brick samples were higher than the compressed unground POFA bricks at all curing ages. However, the density of compressed ultrafine POFA brick was slightly lower than the control brick at 24 days curing when 30 and 40% of ultrafine POFA were used in the mix. With highest value in the chart, this indicated that the compressed ultrafine POFA brick has a good pozzolanic reaction within the sample. The pozzolanic reaction produced a secondary gel to interlock the bonding between the particles and enabled a production of denser brick which was high in compressive strength. With finer size, the ultrafine POFA provides a better filler effect, which filled up pore voids between the particles and decreases the internal pores. The increment of the density is also due to the fact that the finer POFA boosted the pozzolanic reaction with the by-product of hydration to produce secondary CSH gel (Kroehong et al. 2011). The large amount of CSH gel provides a path for the densification of brick, thus assisting pore refinement to produce higher density brick as well as the brick strength. However, with an increased in the amount of POFA, both ultrafine and unground POFA compressed brick had shown a reduction in the density. This is probably due to the dilution effect, which resulted from the excess amount of the POFA at fixed cement content. The degree and the rate of hydration is reduced due to the increased amount of POFA in total weight of paste, resulting in gradual reduction of the CH content and finally leads to the arising issue of the reduction of CSH gel (Altwair et al. 2013). (iii) Water Absorption The results shown in Fig. 5 reveal that all compressed brick made with ultrafine POFA (5.8–15.4%) has lower water absorption than those bricks made from

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2500 12d

Density, kg/m³

2000

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Fig. 4 Density of compressed POFA bricks at 12 and 24 days curing 25

12-d

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24-d 20

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Fig. 5 Water absorption of compressed POFA brick samples at 12 and 24 days curing

unground POFA (11.9–20.5%), particularly at 24 day curing period. At the early age of curing, all brick samples absorbed more water due to less formation of the hydration product. As initial water curing duration increased, more solid hydration products were formed, resulting in lower absorptivity of longer cured specimens (Jaturapitakkul et al. 2011). Significant reduction in the water absorption of all compressed ultrafine POFA brick samples was due to diminishing of the voids through the pore void modification. With high pozzolanic activity, formation of the solid hydration products has produced compressed ultrafine POFA brick with more

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compact microstructure. In addition, the ultrafine POFA also acts as microfiller, which able to cause further pore refinement and air volume reduction. Based on BS 3921:1985, both UF-10 (5.84%) and UF-20 (6.68%) compressed bricks can be considered to fall under the Damp proof Course 2 Class (≤7.0%). Meanwhile, other brick samples (Control, UF-30, UF-40, UG-10, UG-20, UG-30, and UG-40) with water absorption ranging between 11.99 and 20.52% can be categorized under the ‘All other class’ with no restriction to any water absorption limits (≤no limits). On the other hand, MS 76:1972 has specified that for load-bearing brick Class 1–Class 15, there are no specific requirements on the water absorption of the brick. Hence, by considering the compressive strength and water absorption, based on MS 76:1972, the compressed bricks produced in this research can be classified under the load-bearing brick Class 1–Class 5.

4 Conclusion Based on the result obtained, the use of waste material such as POFA is recommended, especially when the material is ground to the finer size. The properties such as compressive strength, density, and water absorption improved by using the ultrafine POFA compared to unground POFA material. All the samples produced in this research complied within the acceptable limit for stabilized clay masonry unit. The production of interlocking compressed soil brick has been started for use in building construction within the UMS campus. The research on POFA, however, still in progress, but some positive findings on their engineering properties have been determined, indicating the potential use of POFA in producing interlocking compressed POFA brick to be used in future construction.

References Altwair, N. M., Johari, M. A. M., & Hashim, S. F. S. (2013). Influence of treated palm oil fuel ash on compressive properties and chloride resistance of engineered cementitious composites. Materials and Structures, 47(4), 667–682. Aldahdooh, M. A. A., Muhamad Bunnori, N., & Megat Johari, M. A. (2014) Influence of palm oil fuel ash on ultimate flexural and uniaxial tensile strength of green ultra-high performance fiber reinforced cementitious composites. Materials and Design, 54, 694–701. Asrah, H., Mirasa, A. K., & Mannan, A. (2015). The performance of ultrafine palm oil fuel ash in suppressing the alkali silica reaction in mortar bar. International Journal of Engineering Applied Science, 9, 60–66. B. Standard. (2004). BS 3921: 1985 Specification for Clay bricks. Jaturapitakkul, C., Tangpagasit, J., Songmue, S., & Kiattikomol, K. (2011). Filler effect and pozzolanic reaction of ground palm oil fuel ash, 25, 4287–4293. Karim, M. R., Zain, M. F. M., Jamil, M., & Islam, M. N. (2011). Strength of concrete as influenced by palm oil. Australian Journal of Basic and Applied Sciences, 5(5), 990–997.

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Kroehong, W., Sinsiri, T., & Jaturapitakkul, C. (2011a). Effect of palm oil fuel ash fineness on packing effect and pozzolanic reaction of blended cement paste. Procedia Engineering, 14, 361–369. Kroehong, W., Sinsiri, T., Jaturapitakkul, C., & Chindaprasirt, P. (2011b). Effect of palm oil fuel ash fineness on the microstructure of blended cement paste. Construction and Building Materials, 25(11), 4095–4104. M. Standard. (1972). MS 76:1972 Specification for bricks and blocks of fired brickearth, clay or shale part 2: Metric units. Madlool, N. A., Saidur, R., Hossain, M. S., & Rahim, N. A. (2011). A critical review on energy use and savings in the cement industries. Renewable and Sustainable Energy Reviews, 15(4), 2042–2060. Malavika, I. P., Nipuna, M., Raina, T. R., Sreelakshmi, A. V., & Kripa, K. M. (2017). Design of interlocking block and replacement of msand by concrete roof tile waste. International Journal of Research in Engineering and Technology, 4(5), 1224–1229. Mo, K. H., Bong, C. S., Alengaram, U. J., Jumaat, M. Z., & Yap, S. P. (2017). Thermal conductivity, compressive and residual strength evaluation of polymer fibre-reinforced high volume palm oil fuel ash blended mortar. Construction and Building Materials, 130, 113–121. Oti, J. E., & Kinuthia, J. (2009). Engineering properties of unfired clay masonry bricks. Engineering Geology, 107(3–4), 130–139. Sata, V., Jaturapitakkul, C., & Kiattikomol, K. (2004) Utilization of palm oil fuel ash in high-strength concrete. ASCE, 623–628. Sinsiri, T., Kroehong, W., Jaturapitakkul, C., & Chindaprasirt, P. (2012). Assessing the effect of biomass ashes with different finenesses on the compressive strength of blended cement paste. Materials and Design, 42, 424–433. Sumadi, S. R., & Hussin, M. W. (1995). Palm oil fuel Ash (POFA) as a future partial cement replacement material in housing construction, 25–34.

Second-Generation Bioethanol: Advancement of Ethanologenic Microorganisms Toward Industrial Production Husnul Azan Tajarudin, Muhammad Syazwan Azmi, Muaz Mohd Zaini Makhtar, Mohd Firdaus Othman and Mardiana Idayu Ahmad Abstract Bioethanol, as a clean and renewable fuel with its major environmental benefits, represents a promising biofuel today which has the potential to provide a sustainable replacement for traditional oil-based fuels. In order to minimize the competition between fuels and food production, researchers are focusing their efforts on the utilization of wastes and by-products as raw materials for the production of ethanol. Food waste and lignocellulosic biomass are being produced in great quantities in any campus cafeteria and their handling can be a challenge. They contain significant amounts of sugars (both soluble and insoluble) and they can be used as raw material for the production of ethanol. The review highlighted a specific part in the production chain of refining lignocellulosic biomass, production of sugar from lignocellulosic biomass during enzymatic hydrolysis and the fermentation of the produced sugars to bioethanol. The study also covered a metabolism of ethanologenic microorganism focusing on glucose and xylose catabolism. Keywords Bioethanol · Fermentation · Bioreactor

1 Introduction In order to promote sustainable living on campus, there is a need to improve the resource conservation. The food waste from campus events and lignocellulosic biomass abundantly in campus have high potential to be recovered their energy H. A. Tajarudin (B) · M. S. Azmi · M. M. Z. Makhtar · M. F. Othman · M. I. Ahmad Division of Bioprocess Technology, School of Industrial Technology, Universiti Sains Malaysia, 11800 Pulau Pinang, Malaysia e-mail: [email protected] H. A. Tajarudin Cluster of Solid Waste Management, Engineering Campus, Universiti Sains Malaysia, 14300 Pulau Pinang, Malaysia M. F. Othman · M. I. Ahmad Division of Environment Technology, School of Industrial Technology, Universiti Sains Malaysia, 11800 Pulau Pinang, Malaysia © Springer Nature Singapore Pte Ltd. 2020 A. Z. Yaser (ed.), Green Engineering for Campus Sustainability, https://doi.org/10.1007/978-981-13-7260-5_6

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(Costello et al. 2016). The reduction of these ‘waste’ would support the energy conservation, water conservation and waste reduction goals of any campus. There is high percentage of food produced goes uneaten, and the potential to divert some of this would have a tremendous environmental and social impact. At the same time, there is significant environmental cost to food that goes to waste, both on the front and back ends (Parfitt et al. 2010). In addition to the resources (i.e., land, water, oil) that go into producing the food, discarded food contributes to over one-fifth of municipal landfills and is the single largest contributor to municipal solid waste in landfills, which is among the largest source of greenhouse gas emissions in any countries (Manaf et al. 2009). In recent years, the development of alternative energy and transport fuels continues to advance. The shifting focus in energy resource is mainly driven by the massive consumption of fossil fuels and elevating consciousness on climate change worldwide. In 2014, world fossils fuels recorded large amount of consumption at approximately 3,639 PJ, 66,076 PJ and 1,764 Mt for oil, natural gas, and coal (World Energy Statistics 2016). The trend is expected to increase and the dependency of fossils fuel as energy and refinery resources will continue for at least the next few decades (Shafiee and Topal 2009). In environmental perspective, this apparent and alarming trend definitely requires a thoughtful countermeasure to reduce emission of greenhouse gas and its negative impacts on the environment. One of the promising solutions is the use of bioethanol as substitute or additive for fossil fuel, achieving that sustainable, clean and economically viable bioenergy production (Balat 2011). The most common renewable resources for bioethanol today are from the firstgeneration feedstock, which are from corn and sugarcane (Boundy et al. 2011). However, first-generation bioethanol faces controversies such as food security and limited resources since the energy demand only achievable through agricultural of edible crops. The net of greenhouse gas production is also questionable because of deforestation for a new arable land result in substantial amount of biofuel carbon debt (Fargione et al. 2008). The emergence of advanced bioethanol or second-generation bioethanol has paved the way for more sustainable production of bioethanol. Lignocellulosic material from nonedible crops or agricultural waste can be used as the feedstock, hence alleviating environmental and social issues related with firstgeneration bioethanol. Third generation bioethanol, although not discussed in this article, is also a sustainable resource of bioethanol. The only drawback is the expensive production, which rendered bioethanol from algal biomass as not commercially viable for now (Slade and Bauen 2013). Superiorities of second-generation bioethanol are cheap, renewable, and abundant source of lignocellulosic biomass. Waste from agricultural the industry and nonedible crop from marginal land covers a large portion of the biomass. The abundant of agricultural waste is undeniable with estimation of 998 Mt being produced annually (Obi et al. 2016). More importantly, it is estimated that global lignocellulosic biomass can potentially produce 442 GL of bioethanol per year, roughly 16 times higher than the current bioethanol production (Kim and Dale 2004). Many researchers have recognized the potential of second-generation bioethanol with extensive researches being conducted for the past three decades (Chandrakant and Bisaria 1998; Lynd et al.

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1991). Results from various pilot-scale researches have indicated positive outcomes, which in turn support that assertion of second-generation bioethanol as fuel for the future (Menetrez 2014; Naik et al. 2010). Ethanologenic microorganisms serve as a collective ‘mini-factories’ in the production of bioethanol. These microbes have distinct fermentation behaviors depending on feedstock’s origin. For lignocellulosic biomass, there is lack of wild strain ethanologens that capable of fermenting all sugars (hexose and pentose) released by hydrolysis. This major challenge promotes metabolic engineering technology to tailor an advanced ethanologens by combining advantageous traits from various microbes. To date, mostly, studied ethanologens for plant biomass conversion are Escherichia coli, Saccharomyces cerevisiae and Zymomonas mobilis (Saxena et al. 2009; Sprenger 1993; Taylor et al. 2012). Other approach includes random mutagenesis and screening to resolve high sensitivity of ethanologens toward process hardiness. Presently, most review articles have focused on pretreatment and hydrolysis processes due to their high impact on the economic viability of bioethanol production (Sun and Cheng 2002; Taherzadeh and Karimi 2008; Yang and Wyman 2008). Nevertheless, fermentation is another important process in achieving high yield, faster conversion rate and high concentration bioethanol. This review presents a discussion on the development of ethanologenic microorganisms for high-performance fermentation, its desired characteristics, feedstock resources, and the employed fermentation system for production of second-generation bioethanol. In addition, this review includes current efforts in the creation of superior ethanologenic microorganism or also known as superbug for industrial production of bioethanol. The main process steps in bioethanol processes will be the same regardless of the raw material used and what kind of by/co-products are produced in the process. The operation of each of the core steps will, however, differ depending on both feedstock and product distribution. The process steps are pretreatment, hydrolysis and fermentation (Fig. 1). In addition to these three core processes, product recovery (mainly distillation) is also needed. Pretreatment of the biomass targets to open up the structure of the fibers and/or to liquefy parts of the material, primarily either the hemicelluloses or the lignin. There are numerous pretreatment methods exist and commonly divided into physical and chemical methods depending on their main mode of action, although a combination of the two is often used (Alvira et al. 2010). Physical methods, such as communition and extrusion, rely on size reduction, and defibrillation of the material. This is as a way to open up the fiber structure and create a larger accessible surface area to improve the enzymatic hydrolysis. Purely physical methods are typically very energy

Pre-treatment

Hydrolysis

Fig. 1 Flow diagram for bioethanol production

Fermentation

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rigorous and are therefore often regarded unfeasible (Hendriks and Zeeman 2009). However, in combination with other pretreatment methods they can be useful. Once pretreatment was done, the important component of the cellulose still remains in polymeric form, and depending on the pretreatment method, some of the hemicelluloses may also remain in polymeric or oligomeric form. To breakdown the reminder of the sugars, a set of enzymes, mainly cellulases, are needed. For a long time, enzymatic hydrolysis was regarded as the primary bottleneck in the production of bioethanol from lingocellulose (Lynd et al. 2008). This was mainly due to the slow action of the cellulase mixtures and the need for large amounts of expensive enzymes. For the fermentation part, there are many potential candidates for bioethanol production such Saccharomyces cerevisiae, Scheffersomyces stipitis, Kluyveromyces marxianus, Dekkera bruxellensis which are commonly used microorganism in sugar- and starch-based bioethanol production today (De Souza Liberal et al. 2007). This will be elaborated later in the fermentation of ethanologenic microorganism’s subsection.

2 Biomass Resource for Second-Generation Bioethanol Biomass is a transformed solar energy from photosynthesis, hence stored chemical energy available for satisfying renewable energy demand. The biomass processes of sucrose or starch containing crops such as sugarcane, sugar beet, maize, and wheat are relatively easy and simple, considering the accessibility of matured bioconversion technology (Lin and Tanaka 2006). However, the increase in bioethanol production from food crops will affect global agricultural commodity prices and food security. This is especially true for most of the feedstocks except sugarcane scenario in Brazil where Brazilian biofuel program promotes agricultural development (Koizumi 2015; Sims et al. 2010). Overall, albeit with conflicts from different studies, many agreed that first-generation bioethanol has several limitations in term of land competition for growing crops and residence (Mohr and Raman 2013; Naik et al. 2010). The conversion of biomass into second-generation bioethanol is different from the first generation due to its variation of biochemical composition. The first-generation biomass conversion is easier due to the presence of readily fermented soluble sugars (mono and disaccharides) and hydrolysed starch prior to fermentation. In contrast, second-generation bioethanol faces more difficulties in the preparation of soluble sugars for the fermentation process. This is due to the presence of recalcitrant molecules with complex linkages, which in turn provides robustness toward enzymatic and chemical degradation. Nevertheless, the concept of second-generation bioethanol is promising due to the abundance of lignocellulosic biomass and its accessibility without the interference of additional land for crops cultivation. The worldwide production of lignocellulosic biomass is around 200 Gt per year, where roughly 20 Gt is available for biofuel production (Limayem and Ricke 2012).

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Generally, plants are consists of three biopolymers: cellulose, hemicellulose, and lignin. Together, these three constituents form a highly complex lignocellulosic matrix that is unique in composition and degree of complexity with different plant species, its age, and stage of growth. Cellulose is a linear, unbranched homopolysaccharide consist of β-D-glucose units joined by β–1,4 glycosidic linkage. There is the formation of hydrogen bonds between hydroxyl groups and oxygen atoms within the repeated single glucose chain and adjacent glucose chains. In addition, the formation of intermolecular and intramolecular Van der Waals forces attach each cellulose chain together and promote parallel stacking of cellulose microfibrils (Somerville 2006). Cellulose exists in two forms, namely crystalline and amorphous form. Former configuration requires more specialized enzyme and less susceptible to enzyme degradation compared with latter configuration (Pérez et al. 2002; Hall et al. 2010). In the economical perspective, lignocellulosic biomass with high content of cellulose is preferred because cellulose content is directly proportional with bioethanol yield (van der Weijde et al. 2013). Hemicellulose is a complex and diverse heteropolysaccharide comprises hexose (β–D–glucose, α–D–galactose and β–D–mannose), pentose (β–D–xylose and α–L–arabinose) and uronic acids (α–D–glucuronic, α–D–galacturonic and α–D–4–O–methylgalacturonic acid). Trace amount of sugars such as α–L–rhamnose and α–L–fructose may also present in this biopolymer. Hemicellulose is more soluble and relatively easy to hydrolyze compared to cellulose due to their amorphous form with short lateral chains and lower molecular weight (Saha 2003). The main structure of hemicellulose is either short branches homopolymer or a heteropolymer linked by β–1,4 glycosidic linkage and sometimes β–1,3 glycosidic linkage. Hemicelluloses in hardwoods, municipal wastes, and agricultural residues, are typically xylan while softwoods are highly in glucomannan (Bajpai 2016). Due to sugars diversity, hemicellulose requires various enzymes to hydrolyze the biopolymer into fermentable sugars. However, the formation of unwanted products such as furfurals and hydroxymethyl furfurals must be avoided to prevent inhibition of fermentation process (Palmqvist and Hahn-Hägerdal 2000). Lignin is a unique amorphous complex biopolymer that does not saccharify into fermentable sugar. The monomers of lignin are three hydroxycinnamyl alcohols of p-coumaryl, coniferyl and sinapyl that forms respective aromatic unit phydroxyphenyl, guaiacyl, and syringyl units (Feofilova and Mysyakina 2016). It has been studied that, lignin from different sources has different ratios of these aromatic units which in turn affect enzymatic hydrolysis of cellulose (Studer et al. 2011). Lignin functions as a supportive polymer that strengthens cell walls within xylem tissue, forming dense structure that binds cellulose microfibrils and other cell walls components, thus giving rigid support and prevents collapsing of vascular plants (Martone et al. 2009). Among lignocellulosic biomass, softwoods have highest lignin content with 30–60% (dry weight), followed by hardwoods with 30–55%. Grasses and agricultural residues have lower lignin content with 10–30% and 3–15%, respectively (Limayem and Ricke 2012). Typical composition inside the woody biomass is presented in Fig. 2. Currently, most lignin residue is burned for the source of heat and power for the processing plant, despite many potential applications (Yuan et al. 2013).

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Chart Title

Fig. 2 Pie chart for the composition inside the woody biomass

2%

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carbohydrate

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extractive

Many lignocellulosic biomass has been studied for the production of bioethanol in the last three decades (DiPardo 2000; Zabed et al. 2017). According to the authors, lignocellulosic biomass can be divided into four groups based on respective sources: dedicated energy crops (switchgrass, silvergrass, and napier grass), forest residues (woodchips, sawdust), agricultural residues (rice straw, cane bagasse, and pulp), and organic municipal solid wastes (recycled paper sludge, waste office paper). Each group has their distinctive characteristics and notable potential for ethanol production and the summary is shown in Table 1. Despite numerous reports, the interest on lignocellulosic feedstock always renewed with discoveries of significant findings and novel technology, particularly in the group of dedicated energy crops. Easily grown crops with fast-growing rate and high biomass yield are the ideal candidates of cellulosic energy crops. These crops are commonly dedicated for biofuel production and they are either belongs to C3 or C4 photosynthetic plants. During photosynthesis, the two types of plant differ in Rubisco oxygenase activity, in which the former may use oxygen as substrate, rendering it less efficient in carbon fixation than the latter (van der Weijde et al. 2013). Apparently, the latter possess higher efficiency in converting solar energy into biomass especially in warm and arid climate. Moreover, nitrogen and water use efficiency is 1.3–4 times higher in C4 plants (Sage and Zhu 2011). Some C4 energy crops are silvergrass (Miscanthus spp.), switchgrass (Panicum virgatum) and bermuda grass (Cynodon dactylon) while C3 energy crops include timothy grass (Phleum pratense L.), reed canary grass (Phalaris arundinacea), giant reed (Arundo donax) and alfalfa (Medicago sativa). These are the common grass that is present in the backyard of any campus and conventionally, the grass waste will be burned out without noticed their valuable profit if converted into the bioethanol fuel (Table 1). Industrial crop and food crop are the two sources of agricultural residues. Available form of industrial crop residues is cotton stalks, flax shives, and hemp hurds. Nevertheless, world top four agricultural residues all originates from food crops, viz. rice straw (731.30 Mt year−1 ), wheat straw (354.34 Mt year−1 ), corn

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Table 1 Summary of the lignocellulosic biomass group for bioethanol production Biomass source

Prominent features and notable potential

References

Dedicated energy crops

• Crops grown specifically for fuel: Switchgrass (Panicum virgatum L.), Napiergrass (Pennisetum purpureum Schumach), Silvergrass (Miscanthus spp) • Able to grow in marginal and polluted lands • High biomass productivity • High tolerance against disease and pests • Convenient for the application of genetic engineering • Low energy investment for cultivation • Biomass yield 5.2–11.1 t DM ha−1 Switchgrass, 27.1–88 t DM ha−1 Napiergrass, not more than 30 t DM ha−1 Silvergrass • Potential ethanol yield is up to 460 L t−1 of biomass

David et al. (2010), Somerville et al. (2010), Rengsirikul et al. (2013)

Agricultural residues

• Rice straw, wheat straw, corn straw, and bagasse are the four major residues in the world • Most tonnage compared to other resources • Easily accessible for agriculture-based countries • Biomass yield 2.25 t DM ha−1 wheat straw, corn stover 2.2–3.4 t DM ha−1 • Potential ethanol yield is up to 480 L t−1 of biomass

Kadam and McMillan (2003), Sarkar et al. (2012)

Forest residues

• Logging residues, forest thinning residue • High bark content will decrease biomass conversion • Non-seasonal harvesting • Increase landfill capacity for other waste and avoid decomposition cost • Potential ethanol yield is up to 455 L t−1 of biomass

Duff and Murrayh (1996), Galbe and Zacchi (2002)

Municipal solid waste

• Cellulose waste comprises 60% dry weight: paper, wood and yard waste • 65 wt% carbohydrate and 10 wt% lignin content • Lower net energy than corn ethanol or cellulosic ethanol • Offset landfill cost such as tipping fees • Potential ethanol yield is up to 154 L t−1 of biomass

Kalogo et al. (2007), Ballesteros et al. (2010), Li et al. (2012)

t–tonne, DM–dry matter, ha–hectare

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straw (203.61 Mt year−1 ), and cane bagasse (180.73 Mt year−1 ) (Sarkar et al. 2012). Asia is the main producer of rice straw and wheat straw, while America is the top contributor for corn straw and cane bagasse generation. The total of four sources can potentially produce 418.9 GL per year bioethanol, in which rice straw alone can potentially produce 205 GL per year (Kim and Dale 2004; Georgieva et al. 2008). For the campus scope, the agricultural residue still among the contributor for the waste in the campus as clearly in the majority of the campus throughout the nation having their some area of clear land which allows the students or staff to farm anything. Unfortunately, during the harvesting process, commonly a huge agricultural residues are throw away/burn. By implementing the technique that was written in this review, all the campus should be implemented this technique. Forest residues include by-products of wood processing mills (sawdust and woodchips) and forest harvest residues from logging operation and forest thinning. These residues typically contain a substantial amount of bark that has different biochemical composition and structure than wood. Bark has less carbohydrate with more extractives and ash, thus leads to lower ethanol yield than woody biomass (Taherzadeh et al. 1997). However, debarking of logging residues is not necessary due to technical challenges and cost related issue. It was reported that bark inclusion (up to 30% dry weight) in the feedstock has a negligible effect on hydrolysates fermentation. The recorded ethanol yield was able to reach more than 0.43 g g−1 (Robinson et al. 2002). Though not all the campus have forest area (some campus having large area of reserve forest), but they are still in the campus which has their own backyard which is being kept for the landscape purpose. So, the residue also can be applied in the bioprocess for harvesting the bioethanol. Municipal solid waste (MSW) is waste generated from household and commercial establishments. Generally, most MSW contains high fractions of organics and papers with lower amounts of inorganic material such as plastics, glass, and metals. Estimation on annual MSW generation around the world has exceeded 2 billion tonnes per year, which suggest a potential threat to environmental sustainability in near future (Karak et al. 2012). With regard to that matter, bioethanol derived from MSW is definitely one of the promising solutions. A study reported that net life cycle energy used in producing MSW ethanol is less than the energy used for producing corn ethanol or cellulosic biomass ethanol (Kalogo et al. 2007). The production of MSW-ethanol also requires less energy from the petroleum source, thus saving more fossil energy (Taherzadeh and Karimi 2008). Patently, cost-effective, and well-established technologies are required for economically feasible bioethanol production. Apart from the difficulty in saccharification process, feedstock characteristics also determine the total cost of bioethanol. Although plant biomass is cheap and abundant, few challenges remain as critical impediments. These include low biomass yield, naturally recalcitrance and costly feedstock’s management. The recent breakthrough involves genetic engineering technology for expression of desired feedstock characteristics in dedicated energy crops. The introduction of ester linkage into the lignin backbone by Ralph et al. (2014) gives nearly double saccharification yield of glucose as compared to normal biomass. Other researches have increased biomass by up to 63% whereas ethanol

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yield by up to 38% in switchgrass plant (downregulation, overexpressing myb4). These studies have opened the possibility of large cost reduction, especially through genetically engineered crops.

3 Metabolism of Ethanologenic Microorganism Hydrolysis of lignocellulosic biomass releases accessible sugars that comprise mainly glucose and xylose, as well as small amounts of arabinose, galacturonic acid, and rhamnose. Metabolism of ethanologens involves biochemical reaction that converts these fermentable sugars into ethanol. While many microorganisms can metabolize glucose and other hexose sugars, only a few microorganisms are able to metabolize xylose and pentose sugars. However, these xylose-fermenting microorganisms such as Escherichia coli, Pachysolen tannophilus and Candida tropicalis can only achieve low rate and yield of ethanol in comparison to glucose fermentation (Jeffries 1981; Slininger et al. 1982). Moreover, pentose sugars are only utilized after D-glucose has depleted in the fermentation, hence leads to an uneconomical long fermentation time (Oreb et al. 2012; Bren et al. 2016). These challenges or undesirable traits of ethanologenic microbes truly require the understanding on pentose and hexose metabolic pathways before the construction of industrial ethanologens can be performed.

3.1 Glucose Catabolism Glycolysis or also known as Embden–Meyerhof–Parnas pathway plays a major role in initial catabolism of glucose into three carbon units, pyruvate. It occurs in two stages namely ATP investment stage (stage 1) and ATP pay off stage (stage 2). In the former, glucose is phosphorylated twice and is split to form two molecules of glyceraldehyde-3-phosphate (G-3-P). Two ATP molecules are utilized in this stage, which is regarded as an investment for further oxidation process. In the latter, G-3-P is converted to pyruvate that yields four ATP and two NADH molecules. Due to the consumption of two ATPs in stage 1, the net production of ATP per glucose molecule is two. In the presence of oxygen, the energy-rich pyruvate can be completely oxidized to CO2 and H2 O that potentially yields 30 more ATP molecules. However, in the anaerobic condition, it can be converted to several types of reduced molecules depending on the type of microorganisms. In ethanologenic microorganism such as yeast and certain bacteria, pyruvate is decarboxylated to acetaldehyde and CO2 . The acetaldehyde is then reduced by NADH to form ethanol, which is excreted later by the cell. Technically, fermentation of glucose to ethanol does not face any grave challenges in contract with xylose, since glucose is always the preferred carbon source that allows faster growth than other sugars. (citation) Fig. 3 shows the overview of ethanol metabolism.

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NADH

D-xylose Xylose reductase

Xylose reductase

Xylitol

NAD+

Xylitol NAD+

NADPH

NADP

Pentose Phosphate Pathway

Xylitol dehydrogenase NADH

Xylose isomerase

D-xylose

H2O CO2

Ethanol D-xylulose

ATP

Xylulokinase ADP

D-Xylulose-5-P Fig. 3 Outline of xylose metabolic pathway in fungi and bacteria. Red and blue arrows represent initial xylose metabolism by bacteria and fungi respectively

3.2 Xylose Catabolism There are three different pathways for xylose catabolism carried out by bacteria, fungi, and Archaea. Figure 3 shows the difference in the way fungi and bacteria channel xylose into the pentose phosphate pathway (PPP). In xylose metabolism by filamentous fungi and some yeasts, D-xylose is converted into xylitol and subsequently into D-xylulose by two respective oxidoreductases, xylose reductase (XR) and xylitol dehydrogenase (XDH), which involve respective cofactors NAD(P)H and NAD+ acting as cofactors. Whereas, bacteria require single enzyme, xylose isomerase (XI) to convert D-xylose directly into D-xylulose without any cofactors. Both fungi and bacteria produce D-xylulose that will be phosphorylated to D-xylulose 5phosphate by xylulokinase (XK) before it is further metabolized through PPP. Most wild xylose-fermenting yeasts produce relatively high amounts of the by-product xylitol, which facilitated by cofactor NADPH. Since there is no transhydrogenase activity in yeasts, redox reaction relies on the balance of cofactors NAD+/NADH and NADP+/NADPH in the yeast intracellular system to metabolize xylose efficiently (Kötter and Ciriacy 1993). Thus, the dual cofactor dependence of XR causes a shortage in NAD since NADH generated by the XDH reaction is only partially regenerate by XR. Consequently, the excess NADH could restrain metabolic activity and it elucidates the poor growth of S. cerevisiae on xylose

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medium (Matsushika et al. 2009). P. stipitis is one of the few yeasts that possess the ability to excrete less xylitol than other yeasts (Debus et al. 1983). Theoretically, prokaryotic XI should be more efficient in metabolizing xylose compared to yeasts because no cofactor is necessary to produce D-xylulose in prokaryote hence intracellular redox imbalance will not occur. Few studies have been conducted which involve two strategies, the expression of prokaryotic XI in high yield ethanologenic yeast and the simultaneous isomerization and fermentation of D-xylose to ethanol. In the former, Brat et al. (2009) have accomplished heterologous expression of XI from bacteria, Clostridium phytofermentansthat have enabled S. cerevisiae to metabolize xylose. However, the growth rates of their recombinant strains are rather low with ethanol yield at 0.43 g ethanol g D-xylose−1 . While in the latter, two-step process by Gong et al. (1981) allows non-xylose-fermenting yeast to ferment xylose using preceding prokaryotic XI in a separate process. The separate isomerization is preferable due to different optimal conditions for isomerization and fermentation. The results indicate that ethanol could be produced from D-xylose with a yield of greater than 80%. The latest discovery of xylose metabolic pathway was in halophilic archaea such as Haloferax volcanii and Haloarcula marismortui (Johnsen and Schönheit 2004; Johnsen et al. 2009). The catabolism occurs through the oxidation of D-xylose to an intermediate of tricarboxylic acid cycle, α-ketoglutarate. The enzymes involved in the degradation process are D-xylose dehydrogenase, xylonate dehydratase, 2-keto-3deoxyxylonate dehydratase, and α-ketoglutarate semialdehyde dehydrogenase. This finding definitely opens a new opportunity toward further manipulation of xylose metabolic pathway. However, due to the inclusion of multiple genes and conversion complexity, there is no research on expressing this metabolic pathway on potential ethanologens yet.

4 On Improving Tolerance Toward Inhibitors The utilization of lignocellulosic biomass demands advantageous traits from the potential ethanologens. These are due to difficulties in achieving an efficient model of integrated process involving the selection of biomass toward the harvesting of bioethanol. Prior to fermentation, pretreatment and hydrolysis processes generate few inhibitors commonly lignin residues, acids, and aldehydes. To date, there was no known method to avoid the formation of these inhibitors except for less severe pretreatment and detoxification process for reducing inhibitors content (Palmqvist and Hahn-Hägerdal 2000). However, one of the drawbacks for such process is the extra cost, which burden on attempts to market bioethanol at a low price (Taylor et al. 2012). Thus, an apparent solution is to enhance the ability of potential ethanologens to become tolerant to these inhibitors.

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5 Fermentation of Ethanologenic Microorganisms The cellulose and hemicellulose fraction of rice straw can be converted to ethanol by either simultaneous saccharification and fermentation (SSF) or separate enzymatic hydrolysis and fermentation (SHF) processes. SSF is more favored because of its low potential costs (Wyman 1994). It results in higher yield of ethanol compared to SHF by minimizing product inhibition. One of the drawbacks of this process is the difference in optimum temperature of the hydrolyzing enzymes and fermenting microorganisms. Most of the reports state that the optimum temperature for enzymatic hydrolysis is at 40–50 °C, while the microorganisms with good ethanol productivity and yield do not usually tolerate this high temperature. This problem can be avoided by applying thermo-tolerant microorganisms such as Kluyveromyces marxianus, andida lusitaniae, and Zymomonas mobilis or mixed culture of some microorganisms like Brettanomyces clausenii and Saccharomyces cerevisiae (Golias et al. 2002; Spindler et al. 1988). Table 2 shows the different substrate, method, and microorganism involved in previous ethanol production research Cellulose processing cannot commence until the improvement of (i) the relatively slow kinetics of breaking down pure cellulose into sugars, (ii) the low yields of sugars from other plant polysaccharides, and (iii) the removal of lignin, a relatively intractable polymer of phenylpropanoid subunits. It is clear that technological advances must be realized to make biofuels sustainable and cost-effective.

6 Toxic Compounds Generated from Pretreatment The attribute and concentration of toxic compounds generated from various pretreatment depend on biomass source, pretreatment condition and the use of catalyst. Three types of toxic compounds were known, viz., furans, phenolic compounds, and carboxylic acids. Among furan derivatives, 2-furaldehyde (furfural) and 5-hydroxymethylfurfural (HMF) constitute the main degradation compounds generated from pentoses and hexoses degradation, respectively. Pretreatments which employ acids as hydrolytic agents and utilize high temperature and time to the reaction will produce furfural and HMF at higher levels (Wyman 2007). Most of the fermenting microorganisms are able to reduce furans to their corresponding less toxic alcohols. HMF is reduced to 2,5-bis-hydroxymethylfuran and furfural to furfuryl alcohol, and both could be also oxidized to formic acid under anaerobic conditions (Taherzadeh et al. 1999). If furans are present at high concentration, they exert an inhibitory effect interfering with glycolytic enzymes and synthesis of macromolecules provoking an enlarge of the lag phase and reducing the ethanol productivity (Almeida et al. 2007; Klinke et al. 2004). These effects depend on furan concentration but are highly related with the yeast strain. Main carboxylic acids generated during pretreatment are acetic acid, produced from the acetyl groups in hemicelluloses, and formic acid, derived from furfural and

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Table 2 Different substrate, method, and microorganism involved in the previous ethanol production research Substrate

Method

Microorganism/yeast Ethanol used produced (g/L)

References

Sugar cane bagasse

Immobilized S. cerevisiae under solid-state fermentation

Fungal species A. flavus ITCC 7680, S. cerevisiae

15.40

Singh et al. (2013)

Dried Household Food Waste

Simultaneous saccharification and fermentation (SSF) and non-isothermal simultaneous saccharification and fermentation (NSSF) in fed-batch mode

Celluclast from Trichoderma reesei ATCC 26921, β-glucosidase from Aspergillus niger

42.66

Alamanou et al. (2015)

Cassava residues and furfural residues

S. cerevisiae with SSF

Saccharomyces cerevisiae

36.00

Ji et al. (2015)

Water hyacinth

Enzymatic hydrolysis and SSF

Saccharomyces cerevisiae

1.29

Zhang et al. (2015)

Mahula flowers

Submerged fermentation

S. cerevisiae (CTCRI strain)

37.20

Behera et al. (2011)

Oil palm empty fruit bunches

Fungal pretreatment, phosphoric acid pretreatment, enzymatic hydrolysis, SSF

White-rot fungus Pleurotus floridanus LIPIMC996

23.00

Ishola et al. (2014)

Sugar beet molasses

Cell immobilization and batch fermentation

S. cerevisiae (strain DTN)

60.36

Razmovski and Vucurovic, (2011)

Sweet potato chips

Liquefaction, saccharification, batch and continuous fermentations

S. cerevisiae ATCC 6508

104.30

Coffee pulp

hydrolysis, fermentation

S. cerevisiae

Corn meal hydrolyzates

Hydrolysis, ethanol fermentation

Rice straw

Acid hydrolysis, ethanol fermentation

Shen et al. (2012)

7.40

Kefale et al. (2012)

S. cerevisiae var. ellipsoideus, S. cerevisiae, S. carlsbergensis and Schizosaccharomyces pombe

89.68

Nikoli´c et al. (2010)

S. cerevisiae OVB 11

12.00

Yadav et al. (2011) (continued)

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Table 2 (continued) Substrate

Method

Microorganism/yeast Ethanol used produced (g/L)

References

Empty palm fruit bunch fibers

The fermentation was carried out under SSF with cellulase and yeast.

S. cerevisiae L3262a w

Park et al. (2013)

Cashew apple bagasse

Dilute acid pretreatment, batch fermentation

Saccharomyces cerevisiae

9.59

Corn stover

Steam explosion pretreatment, ethanol fermentation

Saccharomyces cerevisiae Y5

40.00

Li et al. (2011)

Starch cassava pulp

Saccharification of starch and lignocellulosic fiber in cassava pulp, fermentation

Saccharomyces cerevisiae TISTR 5596

9.90

Akaracharanya et al. (2010)

Waste newspaper

Hydrolysis, fermentation

Pichia stipitis CBS 6054

14.29

Xin et al. (2010)

Newspaper cellulosics

Fed-batch and batch fermentation

S. cerevisiae RCK-1

5.64 (batch) 14.77 (fedbatch)

Chander Kuhad et al. (2010) and Xin et al. (2010)

62.50

Rocha et al. (2014)

HMF degradation. HMF could be also decomposed to levulinic acid being detected at lower concentration. Furthermore, hydroxycarboxylic acids such as glycolic acid and lactic acid are common degradation products from alkaline carbohydrate degradation (Klinke et al. 2004). The dissociated form of weak acids can diffuse across the cell membrane and dissociate inside the cell due to the higher intracellular pH. This fact decreases intracellular pH which must be compensated by pumping protons out of the cell at expense of ATP. Thus, less ATP is available for biomass formation. Furthermore, if pumping capacity of the plasma membrane ATPase is overcome, acidification of cytoplasm and cellular death occur. Some studies have also reported that small amounts of acetic, levulinic, or formic acid could increase glucose consumption rates and ethanol yields because low concentration of acids stimulated the production of ATP (Almeida et al. 2007; Keating et al. 2006). The concentration of dissociated acids in lignocellulosic hydrolysates is dependent on the pH, and therefore pH control is necessary for minimizing acids toxicity. A wide range of phenolic compounds derived from lignin decomposition is also generated during pretreatment. Identified phenols are monomers with an aliphatic substituent with different functional groups: aldehydes, ketones, or acids. Phenolic compounds are present in lower concentrations due to its minor solubilization.

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The concentration and type of phenolic compounds are highly dependent on the raw material since lignin content and chemical structure differ among the different lignocellulosic materials. The hydrolytic conditions during pretreatment are also very important for the functionality of the degradation products, that is, the phenolic aldehydes have been shown to be favored at oxidative acidic conditions (Klinke et al. 2002). After soda pulping wheat straw, phenols r-cumaric and ferulic acids are produced by the hydrolysis of esterified hemicellulose and lignin. Alkaline wet oxidation of wheat straw also produces cinnamic acid derivates. Furthermore, owing to oxidative cleavage of the conjugated double bonds, 4-hydroxybenzoic acid and vanillic acid are formed (Klinke et al. 2002). Some other more abundant phenolic compounds are 4-hydroxybenzaldehyde, vanillin, synringaldehyde, syringic acid, and cathecol. These compounds are toxic because they affect the integrity of biological membranes (Almeida et al. 2007). In general, it is accepted that there is a high amount of degradation products derived from lignin that remain unidentified. As have been mentioned, severe conditions during pretreatment lead to the generation of some toxic compounds that could affect the subsequent hydrolysis and fermentation steps. Some studies have also reported that small amounts of acetic, levulinic, or formic acid could increase glucose consumption rates and ethanol yields because low concentration of acids stimulated the production of ATP (Almeida et al. 2007; Keating et al. 2006). Production of bioethanol usually will undergo whether submerged fermentation or solid-state fermentation (SSF). Submerged fermentation usually implemented in the industrial scale because of the familiarity of the process but this process required a lot of water. Whereas, solid-state fermentation did not gain an interest because of the difficulty in process scale up. However, solid-state fermentation mimic the natural environment that microorganism inhibits which offers more possibilities (Jain et al. 2013). Currently, ethanol fermentation is carried out mainly by submerged fed-batch processes with cell recycle, and a small part is produced through multistage continuous fermentation with cell recycle (Mussatto et al. 2010).

7 Submerge Fermentation In order to produce bioethanol in a cost-effective way, it is important to have a lowcost substrate for fermentation. Commonly submerged fermentation of agricultural wastes such as corn, banana, and potato peels, molasses, and waste food grain was utilized to produce bioethanol. As the agricultural waste is in solid form, in order to carry out submerged fermentation, a solution containing carbon source especially glucose needs to be obtained. Hydrolysate containing different composition of saccharides could be done using acid hydrolysis method or enzyme hydrolysis method. This additional step usually referred to pretreatment process. Pretreatment of the waste such as hydrolysis can be carried out by HCl hydrolysis. Higher yield was observed when 10% substrate concentration, pH 5.5 and particle size of 0.157 mm were used. Saccharomyces species was normally used for fermentation. A 10% inoculum was used and temperatures of 30–35 °C wee applied. A range

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Table 3 An example of enzyme used to feedstock pretreatment for bioethanol production (Arapoglou et al. 2010) Enzyme

Function

Viscozyme

Cell wall degrading enzyme complex from Aspergillus aculeatus which can degrade barley α-glucan to reducing carbohydrate

Ternamyl

Heat-stable amylase from B. licheniformis which can degrade starch

Liquozyme Supra

Heat-stable α-amylase from Bacillus lichneniformis

Celluclast

Liquid cellulase produced from Trichoderma reesei which can degrade carboxymethylcellulose to reducing carbohydrate

of yield of 41–46% ethanol was obtained (Kulkarni et al. 2015). The strategy for the use of enzymes in the production of bioethanol from starch includes two stages: liquefaction and saccharification. In liquefaction, α-amylase, obtained either from thermo-resistant bacteria such as Bacillus licheniformis or from engineered strains of Escherichia coli or Bacillus subtilis is used to reduce the viscosity in the slurry or produce dextrins. In saccharification, the enzymes use dextrins to make glucose. Table 3 below shows an example of an enzyme which is used to feedstock pretreatment for bioethanol production. Sweet sorghum stem was also used as submerged fermentation for bioethanol production, and the cells can first be immobilized on the sweet sorghum bagasse. Then, fermentation is started with sweet sorghum juice with initial sugar concentration of 180.7 g L−1 and the productivity achieved 6.02 g (L h)−1 (Yu et al. 2012). A commercial plant which began its operation in 2005 in China, use a self-flocculating yeast with a production capacity of 680 m3 per day. In this system, six fermentors with volumes of 1000 m3 each were arranged in a cascade, and corn meal hydrolyzate, with a sugar concentration of 200–220 g L−1 , was fed to the fermentation system at a dilution rate of 0.05 h−1 . The final ethanol concentration was reported to be 11–12% v/v. Yeast flocs were retained within the fermentor by baffles to effectively immobilize them, and the yeast concentration within the fermentor was maintained at 40–60 g DCW L−1 (Brethauer and Wyman 2010). Whereas, an advancement in sugarcane fermentation in which low-temperature fermentation was carried out in 25–30 °C. (Palacios-Bereche et al. 2014).

8 Solid-State Fermentation Solid-state fermentation (SSF) is a technique to grow microorganism on moist solid without free-flowing water. The advantage of SSF in bioethanol production is the elimination of sugar extraction step before fermentation during submerged fermentation. Besides, SSF also offer others advantages such as low operation cost, low liquid waste generation, less physical consumption, and benefit the region with water supply problem (Yu et al. 2008). The substrate of SSF should not soluble and

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act as a physical support (Pandey 2001). However, SSF poses some problem which is poor heat removal, hardly to agitate the substrate, aeration problem, moisture distribution problem, rapid microorganism determination and limited type of organism which can adapt to low moisture level (Wang et al. 2010). Table 4 shows an example of different reports published regarding the SSF for bioethanol production. The yield using SSF still relatively low compared to submerged fermentation despite its low cost and easy to operate (Jain et al. 2013). Unfortunately, at this time, SSF may not able to replace solid-state fermentation in producing bioethanol (Hölker and Lenz 2005). SSF cut down the spending on the recovery process. It also allows the reduction of waste mass produce by the local industry, as the substrate is taken from the wine industry. Then, after the SSF produces ethanol, the solid waste of the depleted grape pomace and sweet beet pomace can be used to make fertilizer and paper, respectively (Rodríguez et al. 2010). The US Department of Energy Office of the Biomass Program has developed a scenario for supplying 30% of the 2004 motor gasoline demand with biofuels by

Table 4 Solid-state fermentation (SSF) reported used to produce bioethanol Substrate

Microorganism

Pretreatment

Yield

Reference

Agro residues (Pineapple Orange Sweet lime)

Saccharomyces cerevisiae and Candida albicans.

Autoclave at 121 °C for 20 min

S. cerevisiae produce 1.36% yield through 72 h in pineapple residue

Mishra et al. (2012)

Agro waste (Grape pomace, Sugar beet pomace)

Saccharomyces cerevisiae PM-16

–

Sugar beet pomace gives 98.2% theoretical yield in 48 h Grape pomace give 77.7% theoretical yield in 48 h

Rodríguez et al. (2010)

Sweet potato (Ipomoea batatas L.)

Tricoderma sp. and Saccharomyces cerevisiae

–

172 g/kg of substrate

Swain et al. (2013)

Sugarcane bagasse

Using crude enzyme solution from T. longibrachiatum and Saccharomyces cerevisiae

–

50% ethanol yield

Shaibani et al. (2011)

Sweet sorghum bagasse

Zymomonas mobilis

Sodium hydroxide

179.20 g/kg substrate

Yu et al. (2014)

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the year 2030, which roughly translates to a target of 60 billion gallons per year on a British thermal unit-adjusted basis (Himmel et al. 2007). European Union has developed a vision in which one-fourth of the EU’s transportation fuels will be derived from biofuels by 2030. How to achieve, possible? Biomass has the potential to simultaneously meet the nation’s needs for liquid transportation fuel and for food, feed, and fiber provided that we develop more advanced technologies and make certain land-use changes that would not require more net.

9 Conclusion It was clearly could be seen that around the campus had plenty of sources of waste which could be fully utilized then as sources for the second generation of bioethanol. Green campus objective could be achieved by transforming all the wastes to become a value-added product bioethanol. It looks at potential waste feedstock such as grass, municipal solid waste, and agricultural residue that are readily found in the campus. It is clear from this review that the second-generation sources for bioethanol have an important role in achieving environmental improvement in the campus. Acknowledgements This work was supported by the Fundamental Research Grant Scheme (FRGS)(203/PTEKIND/6711373) and Research University Individual (RUI)(1001/PTEKIND/811262) from the Ministry of Higher Education Malaysia.

References Alvira, P., Tomás-Pejó, E., Ballesteros, M., & Negro, M. J. (2010). Pretreatment technologies for an efficient bioethanol production process based on enzymatic hydrolysis: A review. Bioresource Technology, 101(13), 4851–4861. https://doi.org/10.1016/j.biortech.2009.11.093. Arapoglou, D., Varzakas, T., Vlyssides, A., & Israilides, C. (2010). Ethanol production from potato peel waste (PPW). Waste Management, 30(10), 1898–1902. https://doi.org/10.1016/j.wasman. 2010.04.017. Balat, M. (2011). Production of bioethanol from lignocellulosic materials via the biochemical pathway: A review. Energy Conversion and Management, 52(2), 858–875. https://doi.org/10. 1016/j.enconman.2010.08.013. Brethauer, S., & Wyman, C. E. (2010). Review: Continuous hydrolysis and fermentation for cellulosic ethanol production. Bioresource Technology, 101(13), 4862–4874. https://doi.org/10.1016/ j.biortech.2009.11.009. Costello, C., Birisci, E., & McGarvey, R. G. (2016). Food waste in campus dining operations: Inventory of pre- and post-consumer mass by food category, and estimation of embodied greenhouse gas emissions. Renewable Agriculture and Food Systems, 31(3), 191–201. https://doi.org/ 10.1017/S1742170515000071. De Souza Liberal, A. T., Basílio, A. C. M., Do Monte Resende, A., Brasileiro, B. T. V., Da SilvaFilho, E. A., De Morais, J. O. F., et al. (2007). Identification of Dekkera bruxellensis as a major contaminant yeast in continuous fuel ethanol fermentation. Journal of Applied Microbiology, 102(2), 538–547. https://doi.org/10.1111/j.1365-2672.2006.03082.x.

Second-Generation Bioethanol: Advancement of Ethanologenic …

79

Hendriks, A. T. W. M., & Zeeman, G. (2009). Pretreatments to enhance the digestibility of lignocellulosic biomass. Bioresource Technology, 100(1), 10–18. https://doi.org/10.1016/j.biortech. 2008.05.027. Himmel, M. E., Ding, S.-Y., Johnson, D. K., Adney, W. S., Nimlos, M. R., Brady, J. W., et al. (2007). Biomass recalcitrance: Engineering plants and enzymes for biofuels production. Science, 315(5813), 804. Kulkarni, S. J., Shinde, N. L., & Goswami, A. K. (2015). A review on ethanol production from agricultural waste raw material. Scientific Research in Science, Engineering and Technology, 1(4), 231–233. Limayem, A., & Ricke, S. C. (2012). Lignocellulosic biomass for bioethanol production: Current perspectives, potential issues and future prospects. Progress in Energy and Combustion Science, 38(4), 449–467. https://doi.org/10.1016/j.pecs.2012.03.002. Lin, Y., & Tanaka, S. (2006). Ethanol fermentation from biomass resources: Current state and prospects. Applied Microbiology and Biotechnology, 69(6), 627–642. https://doi.org/10.1007/ s00253-005-0229-x. Lynd, L. R., Laser, M. S., Bransby, D., Dale, B. E., Davison, B., Hamilton, R., et al. (2008). How biotech can transform biofuels. Nature Biotechnology, 26, 169. https://doi.org/10.1038/nbt0208169. https://www.nature.com/articles/nbt0208-169#supplementary-information. Manaf, L. A., Samah, M. A. A., & Zukki, N. I. M. (2009). Municipal solid waste management in Malaysia: Practices and challenges. Waste Management, 29(11), 2902–2906. https://doi.org/10. 1016/j.wasman.2008.07.015. Mohr, A., & Raman, S. (2013). Lessons from first generation biofuels and implications for the sustainability appraisal of second generation biofuels. Energy Policy, 63, 114–122. https://doi. org/10.1016/j.enpol.2013.08.033. Mussatto, S. I., Dragone, G., Guimarães, P. M. R., Silva, J. P. A., Carneiro, L. M., Roberto, I. C., et al. (2010). Technological trends, global market, and challenges of bio-ethanol production. Biotechnology Advances, 28(6), 817–830. https://doi.org/10.1016/j.biotechadv.2010.07.001. Naik, S. N., Goud, V. V., Rout, P. K., & Dalai, A. K. (2010). Production of first and second generation biofuels: A comprehensive review. Renewable and Sustainable Energy Reviews, 14(2), 578–597. https://doi.org/10.1016/j.rser.2009.10.003. Palacios-Bereche, R., Ensinas, A., Modesto, M., & Nebra, S. A. (2014). New alternatives for the fermentation process in the ethanol production from sugarcane: Extractive and low temperature fermentation. Energy, 70, 595–604. https://doi.org/10.1016/j.energy.2014.04.032. Palmqvist, E., & Hahn-Hägerdal, B. (2000). Fermentation of lignocellulosic hydrolysates. II: Inhibitors and mechanisms of inhibition. Bioresource Technology, 74(1), 25–33. doi:https://doi. org/10.1016/S0960-8524(99)00161-3. Parfitt, J., Barthel, M., & Macnaughton, S. (2010). Food waste within food supply chains: Quantification and potential for change to 2050. Philosophical Transactions of the Royal Society B: Biological Sciences, 365(1554), 3065. Saxena, R. C., Adhikari, D. K., & Goyal, H. B. (2009). Biomass-based energy fuel through biochemical routes: A review. Renewable and Sustainable Energy Reviews, 13(1), 167–178. https://doi.org/10.1016/j.rser.2007.07.011. Sprenger, G. A. (1993). Approaches to broaden the substrate and product range of the ethanologenic bacterium Zymomonas mobilis by genetic engineering. Journal of Biotechnology, 27(3), 225–237. https://doi.org/10.1016/0168-1656(93)90087-4. Taherzadeh, M., & Karimi, K. (2008). Pretreatment of Lignocellulosic wastes to improve ethanol and biogas production: A review, International Journal of Molecular Sciences, 9(9), 1621. Taylor, M. P., Mulako, I., Tuffin, M., & Cowan, D. (2012). Understanding physiological responses to pre-treatment inhibitors in ethanologenic fermentations, Biotechnology Journal, 7(9), 1169–1181. https://doi.org/10.1002/biot.201100335. Yu, J., Zhang, T., Zhong, J., Zhang, X., & Tan, T. (2012). Biorefinery of sweet sorghum stem. Biotechnology Advances, 30(4), 811–816. https://doi.org/10.1016/j.biotechadv.2012.01.014.

Microalgae Chlorella as a Sustainable Feedstock for Bioethanol Production Rahmath Abdulla, Tan Kah King, Siti Azmah Jambo and Ainol Azifa Faik

Abstract Microlgae can serve as an excellent feedstock for bioethanol production. The microalgae cells of Chlorella were cultivated and acid hydrolyzed to extract the glucose content in the cells. Production of bioethanol was achieved by fermentation process with the use of yeast Saccharomyces cerevisiae. The bioethanol content was determined by gas chromatography–mass spectrometry (GC-MS). The effect of different parameters such as sulphuric acid concentration, temperature and time on acid hydrolysis was studied. The maximum glucose concentration of 5.382 ± 0.063 g/l was obtained with the conditions of 2.0 M sulphuric acid, 30 °C and 30 min of incubation time. On the other hand, the highest ethanol concentration of 1.126 g/l was obtained with 15% v/v yeast inoculum concentration. Meanwhile, the bioethanol production reached its maximum after 24 h with ethanol concentration and yield of 1.020 g/l and 0.190 g/g glucose, respectively. Keywords Bioethanol · Microalgae · Chlorella · Biofuel

1 Introduction The rapid increase in world population led to the rise of global energy consumption significantly from time to time. Among the energy sources, fossil fuels are the most popular one as it accounts for approximately 87% of the total utilization (BP 2014; ExxonMobil 2014). Furthermore, the continued dependence on fossil fuels is somehow considered unsustainable due to its associated environmental issues and non-renewable properties. Considering these facts, there is an urgent call to explore the alternatives for fossil fuel resources to support the increasing energy demand in R. Abdulla (B) · T. K. King · S. A. Jambo · A. A. Faik Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia e-mail: [email protected] R. Abdulla Energy Research Unit, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia © Springer Nature Singapore Pte Ltd. 2020 A. Z. Yaser (ed.), Green Engineering for Campus Sustainability, https://doi.org/10.1007/978-981-13-7260-5_7

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the world. Renewable energy is a form of alternative energy that can be replenished for continuous utilization. One of the examples of this alternative energy is biofuels, which are the fuels derived from biomass (renewable sources) and can be divided into three common types including biodiesel, bioethanol and biogas (Forssberg 2010; Salar 2013). Quite a number of promising research have been done on the efficiency of substituting bioethanol with gasoline. The compatibility of bioethanol especially with gasoline fuels is undeniable as it can be used as a mixture or in its pure form. So far, United States and Brazil are the world’s leading bioethanol producers with about 45 Mt and 24 Mt, respectively (Proskurina et al. 2018). Varieties of feedstocks can be used up as the starting materials for bioethanol production and the choice of feedstock is dependent on numerous factors such as geography, economy and industry (Harun et al. 2010). Based on the feedstocks used, bioethanol can be divided into three generations. First-generation bioethanol is a fuel that is extracted from food crops such as sugarcane, corn, soybean and others (Naik et al. 2010). However, the first-generation bioethanol has created food-versus fuel debates and some food security issues (Mohr and Raman 2013; Ho et al. 2014). Due to this debate, second-generation bioethanol has been developed which is derived from lignocellulosic feedstocks including agricultural forestry residues, energy crops and short rotation forests (SRFs). Generally, second-generation bioethanol had successfully counteracted the conflicts and competition with food industry (Jambo et al. 2016). Yet, the production of second-generation bioethanol is still not commercially viable as extensive processing and pretreatment stages are required, thus it is cost inefficient (Guo et al. 2013). Third-generation bioethanol refers to algae (microand macro-algae)-based fuel. Recently, the promising features of microalgae have attracted the continuous attention of the world’s researchers to focus on its full utilization for the production of bioethanol. Even though the production of third-generation bioethanol is still under developmental stages, microalgal-based fuel is expected to be the benchmark for a better commercialization in the future (Klein et al. 2018). Microalgae are known to have numerous advantages over other feedstocks. It is able to provide a high content of carbohydrates which are 50–70% per unit of dry weight. These contents then can be used as the fermentation substrate or carbon source for bioethanol production (Ho et al. 2014). The carbohydrates components are glucose, mannose, ribose, xylose, rhamnose and fucose (Harun and Danquah 2011a). Its high growth rates and a very short harvesting cycle make it a viable choice as a sustainable feedstock to meet the demands of continuous bioethanol production (Chia et al. 2018). Compared to lignocellulosic feedstock, microalgae is less resistant to conversion into simple sugars due to its lignin-free composition, thus no delignification process needs to be performed (Guo et al. 2013). Therefore, it is more cost-efficient in the aspect of bioethanol conversion processes. The impacts of microalgal-based bioethanol on the environment are also more beneficial as it is known to have associated with CO2 emissions mitigation. Microalgae are efficient in CO2 fixation since they are able to capture atmospheric CO2 together with solar energy from the sun and convert them into biomass through photosynthesis. Microalgae such as Chlorella vulgaris and Chlamydomonas sp. exhibit this property, which enables them to emerge as one of the most effective channels to reduce the

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composition of the gas in the atmosphere (Ho et al. 2014; Ribeiro et al. 2014). In addition, CO2 released during the fermentation process for bioethanol production can be recycled back for the use of microalgae cultivation. This can effectively minimize the amount of CO2 being released into the atmosphere (Harun et al. 2010). Regarding the living environment, microalgae are able to live in a variety of water environment, which make the cultivation not dependent on arable land availability (Hernández et al. 2015). Microalgae are highly specialized group of microorganisms that are able to live in harsh conditions due to their unicellular or simple multicellular structures (Miranda et al. 2012). High degrees of environmental tolerance ensure their easier isolation from the habitat (Ho et al. 2014). So far, the potential of microalgae in biodiesel production has been acknowledged due to its high lipid content. As a matter of fact, the outstanding benefits that offered by microalgae for bioethanol production mainly depend on its high carbohydrate content (Ho et al. 2013a, b). The exploitation of microalgae such as Chlorella, Chlamydomonas, Porphyridium, Scenedesmus and Spirogyra has proven their capability as a potential feedstock for bioethanol production (Hernández et al. 2015). As a comparison, Chlorella sp. is one step ahead than the others in its sustainability as the growth rate is exceptionally fast and no controversial issues related to food shortage (Lee et al. 2014). However, the major concern in the industry nowadays is the commercial viability of the bioethanol production technologies. Hence, it is important to employ the most effective and economical technology that can produce high-quality bioethanol with lesser cost. This research was set out to study the utilization of microalgae Chlorella sp. as a sustainable feedstock for bioethanol production. The initial part of this research started with the monitoring of Chlorella sp. growth rate to determine the most suitable period to harvest the microalgae cells. Under optimum or favourable growth conditions, microalgae are believed to grow at an optimum rate, which leads to a high rate of carbohydrate accumulation. Then, the main focus was directed for the optimization of conversion technologies which were acid hydrolysis at the first stage and followed by the optimization of bioethanol fermentation at the second stage.

2 Cultivation of Chlorella Species Microalgae Chlorella sp. was kindly gifted by the Borneo Marine Research Institute (BMRI) of Universiti Malaysia Sabah. Microalgae Chlorella sp. was cultivated in 1 L conical flask with 10 replicates. Jaworski’s Medium (JM) was used for the cultivation of Chlorella sp. The microalgae cultures were maintained at a temperature of 25–27 °C. The air was supplied throughout the cultivation process as shown in Fig. 1. Microalgae growth was monitored and determined throughout the cultivation process. Approximately 20 ml of sample was taken once in three days for this analysis. Microalgae cell concentration was estimated by measuring optical density at a wavelength of 750 nm (OD750 ) using a calibrated UV/Vis spectrophotometer (Cecil CE

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Fig. 1 Cultivation of Chlorella sp.

1011, 1000 series) for every 3 days, up to 30 days (Leupold et al. 2013; Tuantet et al. 2014). Microalgae cells were harvested during their mid-exponential phase. The microalgae cultures were centrifuged at 4500 × g for 10 min. The resulting supernatant was discarded and the pellet was washed with distilled water (dH2 O) in order to discard the impurities. The centrifugation process was repeated under the same condition. The concentrated pellet was transferred to a petri dish and dried in an oven at 60 °C for 24 h. The dried microalgae were homogenized by using a blender and stored at room temperature (Harun et al. 2010; Harun and Danquah 2011b). Figure 1.2 shows the growth curve of microalgae cells for 30 days. According to the growth curve, the microalgae cells showed positive growth pattern from day 0 up to day 27. From day 0 to day 6, the number of microalgae cells were increased moderately as the absorbance value was increased from 0.013 ± 0.002 to 0.100 ± 0.005. From day 6 to day 15, the microalgae cells showed a significant growth trend as observed in Fig. 1.2 and the absorbance increased from 0.100 ± 0.005 to 0.608 ± 0.060. From day 15 to day 27, the growth rate started to decrease with the increase of absorbance value of only 0.143, to 0.751 ± 0.094 at day 27. From day 27 to day 30, the number of microalgae cells had started to decline. The absorbance value at day 30 was 0.690 ± 0.077, which was 0.061 lesser than that at day 27.

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Fig. 2 Microalgae growth curve for 30 days

According to Fog and Thake (1987), there are five defined growth phases in batch cultures of microalgae which are lag, exponential, declining growth rate, stationary, and death phase. However, according to Fig. 1.2, only four growth phases were observed with no stationary phase. From day 0 to day 6, the microalgae cells were in their lag phase. Lag phase is the phase where the microalgae cells start to adapt to their environment including temperature, light intensity, as well as medium composition and pH. At this stage, the number of viable cells remained nearly stationary (Held 2011). Following lag phase, the microalgae cells entered the exponential phase or log phase during day 6–day 15. During this phase, the microalgae cells were growing at a rapid rate as there were plenty of nutrients to be utilized for the cell metabolism. From day 15 to day 27, the cells entered declining growth rate phase. During this phase, the cells grew at a slower rate and yet, the number of viable cells was still increasing. From day 27 to day 30, the cells entered death phase where the number of viable cells started to decrease (Held 2011; Burlew 1976). The growth phase determination was important as microalgae cells would be harvested during the exponential phase for the subsequent acid hydrolysis process. This is due to the maximum growth rate of microalgae cells achieved during exponential phase. Similar growth curve and growth pattern were reported in previous studies. Makareviˇcien˙e et al. (2011) reported that the exponential phase of microalgae cells was observed in the period of day 5–day 15. In their study, microalgae Chlorella sp. was cultivated in medium with different nitrogen concentration and sources, yet similar periods of exponential phase were observed through different cell densities. The cell density is strongly influenced by dissolved oxygen and carbon dioxide concentration, light intensity, temperature, medium composition and pH as well as salinity (Ho et al. 2014; Liu et al. 2014a, b). According to Guo et al. (2013), the exponential phase of growing microalgae cells was reported to be in the period of day 4–day 15. The length of the exponential phase is dependent on the nature of several factors and these factors decide when the microalgae cells will enter the declining growth phase and stationary phase. One of the most important factors is the depletion of

86 Table 1 Optimized parameters for acid hydrolysis

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Parameter

Values

Sulphuric acid concentration (M)

0.0, 0.5, 1.0, 1.5, 2.0, 2.5

Temperature (°C)

110, 115, 120, 125, 130

Time (min)

10, 20, 30, 40, 50

nutrients. The addition of the limiting nutrients is going to prolong the exponential phase until the other factors become limiting. Other factors are the reduction of light intensity by self-shading, change in pH, rate of gaseous supply, and availability of auto-inhibitors (Fog and Thake 1987).

3 Optimization of Acid Hydrolysis The dried microalgae (10 g/l) was loaded in 250 ml conical flask containing 100 ml distilled water and sulphuric acid. After acid hydrolysis, the sample was cooled down to room temperature, followed by centrifugation at 4500 × g for 10 min. The resulting pellet was discarded and the supernatant was adjusted to pH 7 by using 5 M sodium hydroxide (NaOH). The supernatant or hydrolysate was subjected to a temperature of 120 °C for 30 min prior to fermentation. Once the process was completed, the sugar content of the hydrolysate was analysed (Harun et al. 2010; Harun and Danquah 2011a). The acid hydrolysis parameters including sulphuric acid concentration, temperature and time were also optimized. The baseline parameters of acid hydrolysis were 1 M of sulphuric acid, 120 °C and time of 30 min of reaction time (Harun et al. 2010; Harun and Danquah 2011b). Table 1 shows the optimized parameters for acid hydrolysis. The sugar content of the sample was determined by Dinitrosalicylic acid (DNS) method (Fu et al. 2010). 3.0 ml of the sample solution were mixed with 1.0 ml of DNS reagent. The mixtures were heated to 100 °C for 5 min. The absorbance of the sample mixtures was determined by a spectrophotometer at a wavelength of 540 nm. Glucose solutions with different concentrations were prepared and used to obtain the calibration curve. Acid hydrolysis was carried out by adding 10 g/L dried microalgae into a solution containing different concentrations of sulphuric acid at a specified high temperature. Following incubation, the resulting glucose concentration of the hydrolysate was measured spectrophotometrically by using DNS method.

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Fig. 3 Effect of sulphuric acid concentration on acid hydrolysis of Chlorella

3.1 Effect of Sulphuric Acid Concentration on Acid Hydrolysis Different concentrations of sulphuric acid, ranging from 0.5 to 2.5 M, were used in the acid hydrolysis while temperature (120 °C) and incubation time (30 min) were kept constant. Figure 1.3 shows the relationship between the concentration of sulphuric acid used in the hydrolysis process and the concentration of the glucose released. The concentration of glucose was increasing trend, starting from 0.5 M until 2.0 M sulphuric acid where the highest peak was observed. Based on Fig. 1.3, acid hydrolysis with 2.0 M sulphuric acid showed the highest peak with highest concentration of glucose, which was 3.107 ± 0.043 g/l. Higher concentration of sulphuric acid (2.5 M) showed lower glucose concentration with value of 2.267 ± 0.022 g/l. Acid hydrolysis with 0.5 M sulphuric acid had only 0.049 ± 0.017 g/l glucose, which was the lowest among different sulphuric acid concentrations used. Thus, in this study, acid hydrolysis with 2.0 M sulphuric acid showed the highest concentration of glucose (3.107 ± 0.043 g/l). However, at higher acid concentration, the concentration of glucose was reduced to 2.267 ± 0.022 g/l. This result was similar to the study conducted by Atidiya et al. (2015). In their study, 2.0 M sulphuric acid was proven to have the highest sugar yield which was 9.71 g/l or 32.37 g/g % with rice straw as a substrate. A similar trend was reported by Wang et al. (2014), Miranda et al. (2012) and Manzoor et al. (2012) from different types of microalgae namely Tribonema sp., Scenedesmus obliquus and also dry sugar cane bagasse, respectively. The above trend can be explained by the inhibitory effect of high concentration of sulphuric acid. According to Ajani et al. (2011), acid hydrolysis conducted at high acid concentration and relatively high temperature might result in the lower amount of glucose concentration in the hydrolysate as the extracted glucose can be converted to organic acid. The inhibitory effect was also reported by Talukder et al. (2012) when they were working with microalgae Nannochloropsis salina. Higher acid concentration might result in degradation of glucose into furfural and

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Fig. 4 Effect of incubation temperature on acid hydrolysis

hydroxymethylfurfural (HMF). In their study, higher sulphuric acid concentration showed lower concentration of glucose but a higher concentration of furfural and HMF. The presence of organic acids, furfural and HMF affects the subsequent fermentation process, delaying or inhibiting it (Miranda et al. 2012). Nevertheless, some studies reported different results. Harun and Danquah (2011b) reported that the amount of sugars released was decreasing with the increase of sulphuric acid concentration even at very low acid concentration. In their study, the lowest sulphuric acid concentration performed (1% v/v) was proven to yield the highest concentration of extracted glucose from microalgae Chlorococcum humocola. In contrast, Ho et al. (2013) reported that higher concentration of sulphuric acid resulted in a higher concentration of extracted glucose. In their study, microalgae Scenedesmus obliquus biomass pretreated with 2.5% of sulphuric acid or higher showed nearly 100% glucose yield.

3.2 Effect of Temperature on Acid Hydrolysis The acid hydrolysis was carried out at different incubation temperatures, ranging from 110 to 130 °C with 5 °C increment, while sulphuric acid concentration (2.0 M) and incubation time (30 min) were kept constant. Figure 1.4 shows the relationship between the incubation temperature and the concentration of glucose. According to Fig. 1.4, higher temperature resulted in a higher concentration of extracted glucose as an increasing trend was observed. Highest peak was obtained at 130 °C with a concentration of glucose of 5.382 ± 0.063 g/l. The lowest peak can be observed when 110 and 115 °C were used which had a glucose concentration of 1.604 ± 0.036 g/l. In this study, the highest concentration of extracted glucose (5.382 ± 0.063 g/l) was found to be achieved with the incubation temperature of 130 °C. However, different studies had reported different optimum temperatures or temperature ranges

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Fig. 5 Effect of incubation time on acid hydrolysis

for acid hydrolysis. Harun and Danquah (2011b) who were working with microalgae C. hemicola suggested that temperature of 140 °C was the most suitable condition for acid hydrolysis. However, Miranda et al. (2012) reported that incubation temperature of 120 °C was the optimum one for the acid hydrolysis of microalgae S. obliquus. It was proven that 120 °C was the most efficient temperature for biomass sugar recovery. Mutripah et al. (2014) reported that temperature range of 120 °C–130 °C was the optimum condition for acid hydrolysis when they were working with seaweed Palmaria palmate. Nevertheless, several studies reported that increase in temperature resulted in an increase in the amount of extracted glucose. Chen et al. (2012) reported that extracted sugar concentration in hydrolysate was generally increasing with the increase in temperature. However, decomposition of glucose may occur at a higher temperature. In addition, Harun and Danquah (2011b) also stated that temperature of 160 °C or above resulted in a decrease of the concentration of extracted glucose. This is due to the direct solubilization of the complex sugars which led to the distortion of the formation of glucose molecules.

3.3 Effect of Time on Acid Hydrolysis The acid hydrolysis was conducted for different periods of time (10, 20, 30, 40 and 50 min) while the sulphuric acid concentration (2.0 M) and incubation temperature (130 °C) was kept constant. Figure 1.5 shows the relationship between the incubation time and the concentration of the glucose. The concentration of glucose was increasing gradually with the increase of incubation time from 10 min to 30 min where the highest peak was observed. The concentration of the extracted glucose at the peak (30 min) was 5.382 ± 0.063 g/l. From 30 to 50 min, a decreasing trend was observed. The concentration of extracted glucose dropped significantly to 1.897 ± 0.066 g/l for 50 min.

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Incubation duration affects the acid hydrolysis significantly as the duration influences the availability of free glucose that is fermentable. In this study, the concentration of extracted glucose was found to be maximum for incubation duration of 30 min. At time above 30 min, the concentration of glucose reduced. The decrease in glucose yield with increased incubation longer than 30 min is supported by the study conducted by Chen et al. (2012). In their study, 30 min was proven to be the optimum incubation time for acid hydrolysis of algal biomass. Besides, the obtained result is in agreement with Harun and Danquah (2011b). They reported that pretreating the microalgae cells for a duration longer than 30 min resulted in lower sugar yield and thus lower bioethanol production. Similar incubation duration was proven to be optimal as reported by earlier studies. Sarkar and Aikat (2013) reported that 30 min was the optimum duration for acid hydrolysis when they were working with rice straw. In their study, the maximum sugar yield of 19.35 g/L was obtained when the rice straw waste was pretreated with 0.24 mol/l sulphuric acid for 30 min. Apart from that, Saucedo-Luna et al. (2010) reported that acid hydrolysis of the bagasse of Agave tequilana Weber had their maximum yield of 15.0 g/l fermentable sugars for the duration of 30 min. Most of the related studies stated that higher incubation duration might result in a reduction of sugar yield. Higher duration tends to prolong the acid hydrolysis process and under the condition of high temperature and high sulphuric acid concentration, this will enhance the production of furfural, HMF and organic acids. Hence, a lower concentration of extracted glucose or sugar will be obtained (Saucedo-Luna et al. 2010; Talukder et al. 2012; Wang et al. 2014). Despite the studies highlighted above, some studies had reported very different ranges of the optimum incubation period. Markou et al. (2013) reported that the maximum reducing sugars yield was achieved after the incubation period of 30 h when they were working with cyanobacteria Arthrospira platensis. Other than that, Laopaiboon et al. (2009) suggested the incubation period of hours for acid hydrolysis when they were working with sugarcane bagasse. The incubation period for acid hydrolysis is believed to be correlated to the temperature and sulphuric acid concentration. If relatively high acid concentration and high temperature are used in the acid hydrolysis, shorter duration is preferred to prevent the formation of inhibitors.

4 Yeast Inoculum for Fermentation Yeast inoculum was prepared by dissolving 1.0 g of dry Saccharomyces cerevisiae powder in 20 ml of warm water at room temperature. The solution was left for 30 min with shaking and stirring uniformly to suspend the yeast cells (Harun et al. 2010). The yeast cells were inoculated on Yeast Extract–Peptone–Dextrose (YPD) agar plates using streaking method for single colony isolation purpose. The agar plates were incubated at 30 °C for 24 h. After incubation, the yeast colony was aseptically transferred from the YPD agar plate into 100 ml of sterilized YPD medium containing

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Fig. 6 Yeast growth curve for 48 h

2% glucose. The yeast culture was incubated in a shaking incubator at 200 rpm and 30 °C (Zhou et al. 2011). Yeast growth was monitored by periodically measuring the optical density of the culture at 600 nm (OD600 ) by using UV/Vis spectrophotometer (Cecil CE 1011, 1000 series) for every 3 h, up to 48 h (Zhou et al. 2011; Cho et al. 2013; Kim et al. 2013).Yeast cells were harvested during their mid-log phase by centrifugation. Centrifugation was carried out at 3,000 × g for 10 min. The supernatant was discarded and the pellet was washed with distilled water. The centrifugation process was repeated three times to eliminate the residual sugars in the culture medium. The resulting supernatant was discarded. The pellet was transferred to 250 ml conical flask containing 100 ml fresh YPD medium and was used in the subsequent fermentation process (Harun and Danquah 2011b). Yeast growth was observed by measuring optical density of the yeast suspension culture at 600 nm (OD600 ) using UV-Vis spectrophotometer for every 3 h up to 48 h. The growth curve was plotted as shown in Fig. 1.6. The growth curve showed an increasing trend from 0 to 42 h and decreasing trend from 42 to 48 h. According to Fig. 1.6, there was a negligible increase in yeast growth from 0 to 3 h as the increase of absorbance value was only 0.013. From 3 to 9 h, yeast growth showed a small degree increase, from absorbance value 0.013 ± 0.004 to 0.191 ± 0.003. From 9 h to 15 h, yeast cells had shown a significant growth as the absorbance value was increased sharply to 1.661 ± 0.004. From 15 to 42 h, the yeast growth was slowed down. The absorbance value recorded at 42 h was 1.990 ± 0.003 which was only 0.361 increased from that of 15 h. From 42 to 48 h, yeast growth had started to decline as the absorbance value was dropped to 1.983 ± 0.002 and 1.972 ± 0.01 at 45 and 48 h, respectively. In this study, yeast growth was monitored by measuring the optical density. The absorbance value recorded was proportional to the cell mass. According to Fig. 1.6, from 0 to 6 h, the yeast cells were adapting to the external environment. At this stage, the yeast cells are said to be in their lag phase as negligible growth was observed. During this phase, the cells were actively metabolizing, in preparation for cell division in the subsequent exponential phase. Following lag phase, yeast cells

92 Table 2 Optimized parameters for bioethanol production

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Parameter

Values

Yeast inoculum concentration (% v/v)

5, 10, 15, 20, 25

Time (h)

12, 24, 36, 48, 60, 72

entered their exponential phase from 6 to 15 h. During this phase, the yeast cells showed significant growth as steep growth curve pattern was shown in Fig. 1.6. The generation time or rate of growth is dependent on the organism itself while strongly influenced by the growth medium and the other growth conditions. From 15 to 42 h, the yeast cells were said to be in their stationary phase. During this phase, the yeast cells stopped dividing rapidly and slowed down their metabolism. From 42 to 48 h, the yeast cells were in their death phase as the growth pattern started to decline due to the presence of inhibitors, alteration of growth conditions, and nutrients depletion (Asaduzzaman 2007). Generally, a similar growth curve pattern was shown in most of the studies that were related to yeast growth monitoring. As stated by Asaduzzaman (2007) who was working on the standardization of yeast growth curves, yeast cells experienced lag phase, exponential phase, stationary phase and death phase. A sigmoidal curve was reported in his study. The similar growth curve was also reported by Medawar et al. (2003) and Held (2010). A similar period of exponential phase was reported in the study conducted by Lange and Steinbüchel (2011). In their study, the exponential phase of yeast cells Saccharomyces cerevisiae was observed during the period of 8–18 h when they were cultivated in YPD medium, similar to that in this study. For the use in subsequent alcoholic fermentation, microalgae cells were harvested during their exponential phase, which was between 6 and 15 h, as the maximum rate of cell division was achieved during the exponential phase. Yeast cells with maximum growth rate and metabolism rate were known to utilize the nutrients in their growing medium efficiently. Therefore, yeast cells in exponential phase were used in the production of bioethanol to permit the maximum utilization of available glucose in the hydrolysate, so that maximum ethanol yield could be achieved.

5 Optimization of Bioethanol Production The hydrolysate (50 ml) obtained from acid hydrolysis was added to the YPD fermentation medium with different inoculum concentrations. The fermentation process was conducted for 72 h. The sample was withdrawn from the fermentation medium for bioethanol analysis. Table 1.2 shows the parameters optimized and their respective range of values. The bioethanol content of the sample was analysed by using Gas Chromatography–Mass Spectrometry (GC-MS) equipped with a thermal conductivity detector (TCD) and an HP-5MS column (0.25 mm × 30 mm × 0.25 µm ID). 1.0 µl of sample was injected into the GC-MS in split mode with a split ratio of 200:1. Helium gas with

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99.995% purity was used as the carrier gas and its flow rate was set at 0.7 ml/min. The initial temperature of the oven is 40 °C and was increased at a rate of 10 °C/min up to 100 °C (Mansa et al. 2013). Prior to the analysis, the sample was distilled and sodium sulphate anhydrous (NaSO4 .H2 O) was added to the resulting distillate to remove the water in it. The addition of NaSO4 .H2 O was conducted slowly until there is no formation of solid upon further addition. The sample was diluted with HPLC grade dichloromethane buffer. The sample was then syringed through a 0.45 µm Durapore (PVDF) syringedriven filter unit into 1.5 ml vials. The vials were sealed with a crimp cap and stored at 5–8 °C prior to analysis (Mansa et al. 2013). Ethanol solutions with different concentrations were prepared and used to plot the calibration curve in order to obtain the bioethanol concentration of the sample.

5.1 Effect of Yeast Inoculum Concentration on Bioethanol Production Fermentation was carried out with different yeast inoculum concentrations and the fermentation samples were analysed after 24 h to determine their respective bioethanol content. Figure 1.7 shows the relationship between the inoculum concentration and the bioethanol production. From the inoculum concentration of 5.0–15.0% v/v, both the ethanol concentration and ethanol yield were in an increasing trend. Nevertheless, from 15.0 to 25.0% v/v, the bioethanol production showed a decreasing trend for both the ethanol concentration and ethanol yield. According to Fig. 1.7, the maximum bioethanol production was achieved with the inoculum concentration of 15.0% v/v. The ethanol concentration of 1.126 g/l was achieved and the ethanol yield obtained was 0.209 g/g glucose. In this study, up to 15% v/v, increasing the concentration of yeast inoculum resulted in an increase of bioethanol production from microalgal hydrolysate. At higher concentration of yeast inoculum, both the concentration of bioethanol and the ethanol yield were decreasing. Optimum inoculum concentration of 15% v/v produced an ethanol yield of 0.209 g/g glucose with 1.126 g/l of bioethanol concentration. A similar trend was observed in previous studies where lower bioethanol concentration or yield was obtained at yeast inoculum concentration that was higher than optimal. Minh and Dao (2013) reported that fermentation with yeast ratio of 11% v/v showed lower ethanol concentration than that of 9% v/v. In their study, 0.43% v/v of ethanol was produced with 11% v/v yeast ratio while 1.43% v/v of ethanol was obtained with 9% v/v yeast ratio. Besides, Thenmozhi and Victoria (2013) stated the similar bioethanol production trend when they were working with cauliflower and cabbage waste samples. In their study, 20% v/v yeast inoculum was proven to be optimal. However, at higher yeast inoculum concentration, the ethanol yield decreased. This trend might be related to the inhibitory effect of the oversaturation of

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Fig. 7 Effect of yeast inoculum concentration on bioethanol production from Chlorella sp.

the yeast cells in the fermentation broth. Excessive colonization of yeast cells in the fermentation broth may cause the stimulation of the formation of inhibitors and the presence of inhibitors may affect the fermentation efficiency, thus lower bioethanol concentration is obtained. However, there are studies that reported different results. In those studies, increasing yeast inoculum concentration resulted in the increase in bioethanol production. No reduction of bioethanol production was shown even though the yeast inoculum concentration used was higher than the optimum concentration. The study of Gibdons and Westby (1986) showed that higher yeast inoculum concentration showed no advantages as compared to the optimum concentration. This result is in agreement with the study conducted by Sevda and Rodrigues (2011). Higher inoculum concentration gave almost similar ethanol concentration as optimum when they were working with guava. Higher concentration may require higher capital investment and operating costs to produce a large amount of inoculum. Therefore, the lower optimum concentration with highest bioethanol production was preferred.

5.2 Effect of Time on Bioethanol Production Fermentation was carried out for 72 h to determine the bioethanol production at different duration. Figure 1.8 shows the relationship between the time and the bioethanol production. From 12 to 24 h, both the ethanol concentration and ethanol yield were

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Fig. 8 Effect of time on bioethanol production from Chlorella sp.

increased. However, starting from 24 until 72 h, both the ethanol concentration and ethanol yield were decreased. The ethanol concentration and ethanol yield obtained were 1.020 g/l and 0.190 g/g glucose, respectively. Different ethanol concentrations and yields were observed at different time. In this study, both the ethanol concentration and yield were at their peak at 24 h as shown in Fig. 1.8. This result was supported by previous studies. The study of Harun et al. (2010) reported that the maximum bioethanol concentration was achieved at 24 h when they were working on microalgal biomass. The maximum glucose consumption of approximately 60% was achieved at 24 h. Besides, Kim et al. (2013), who was working with microalgae Chlorella Vulgaris, also stated that bioethanol concentration reached its maximum at 24 h. In their study, 89% conversion was achieved at 24 h in batch-type fermentation. This result is in agreement with the study conducted by Scholz et al. (2013). In their study, glucose was consumed almost entirely at 24 h and the rate of ethanol production was proven to be maximum during the time period of 8 to 24 h. Harun and Danquah (2011b) also reported that the highest ethanol concentration was produced at 24 h, same time as the highest yeast concentration in the fermentation medium when they were working with microalgae Chlorococcum sp. At time above 24 h, the bioethanol concentration in the fermentation medium was decreasing and then slowly stabilized. The decrease in bioethanol concentration can be explained by the depletion of glucose. As the glucose is depleted, yeast cells switch their metabolism. Harun et al. (2010) suggested that the change in yeast metabolism might also include the consumption of bioethanol as the substrate. Therefore, lower bioethanol concentration was observed at the time above the optimum duration.

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Furthermore, the yeast concentration in the fermentation medium decreased after 24 h as reported by Harun and Danquah (2011b). Lower yeast concentration resulted in the decrease of bioethanol production. Other than previous studies on microalgae, the time course of the ethanol fermentation was also studied on other biomass. Yu et al. (2014) reported that ethanol was accumulated rapidly during the first 24 h of fermentation when they were working with fermented sweet sorghum bagasse. This indicates that maximum bioethanol production reached by 24 h with ethanol yield of 157.68 g/kg. However, a study on oil palm fond showed different optimum time for alcoholic fermentation. Hong et al. (2013) reported that the optimum time for maximum bioethanol was at 36 h instead of 24 h. From here, it is believed that optimum fermentation time for bioethanol production may be biomass-specific or may be influenced by the biomass sources.

6 Economical Aspects of Bioethanol Production from Microalgae It is forecasted that microalgal biomass can contribute to the sustainable feedstock sources for bioethanol in the incoming years. The valuable characteristics which come from its high productivity rate, adaptability to the extreme conditions and different water environment and its form of renewable energy are the major driven forces that make it the fuels of the future (Brownbridge et al. 2013). Though these are the main advantages, problems still arise, especially on its viability for the largescale production. Technical challenges, including high input cost for cultivation and harvesting, inadequate consistency in conversion technologies as well as high energy requirements are some constraints that need to be addressed for a better microalgalbased bioethanol commercialization (Brownbridge et al. 2014). Each stage in the cycle during the production process must be taken into account during the economical analysis. The high cost of supply chains such as raw materials, storage, transportation and processing technologies mainly affects the economic viability of bioethanol at this stage. Figure 1.9 shows the general production flow of bioethanol from microalgae feedstock which involves strain selection, cultivation, harvesting, conversion technologies and finally production of bioethanol. There are many conflicts that need to be managed properly in the first place before any difficulties occur during the process of bioethanol production. According to IAE Bioenergy (2011), to compete with the fuels derived from non-renewable energy sources, several technical challenges must be confronted. These include the identification of production chains with net energy output, targeted research and development (R&D) which focus on reducing the cost in all segments of the production spectrum, the intense identification of algal strain high production rates and the initiatives to integrate microalgal biofuels into the existing transportation sector. For the past several years, the majority of the researchers conducted are focusing on the sustainability and the economic viability of microalgal biofuels. As an example,

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Fig. 9 General production flow of bioethanol from microalgae feedstock

Life-cycle assessment (LCA) is widely used as an intermediate to analyse the environmental impacts associated with all stages of microalgal’s life from raw to end product for large-scale bioethanol production. However, based on the results, no uniform conclusion can be made as to compare each and every method applied from different research is quite impractical. These variations specifically come from a different approach in the processing of microalgal biomass, efficient conversion technologies, different LCA methods, hypotheses and parameters being used (Driver et al. 2014). Among the stages of bioethanol production, downstream processing is found to be significantly important in determining the efficiency and economy of the whole processes. In order to make the process more attainable, the enhancement in R&D must be strengthened so that reliable, competent and economical processing technologies could be developed (Kirrolia et al. 2013). Furthermore, the main challenges itself come from the input materials such as the feedstock recovery and high energy requirement (Wan et al. 2015). From the estimation, the harvesting of microalgal biomass is about 20–30% of total production cost which is quite unreasonable, especially for the large-scale production (Pienkos and Darzins 2009). Hence, it is demanded by the biofuels industry an efficient harvesting method which can attenuate the cost of production. The high microalgal growth rate is expected to minimize the cost as it reduces the time between harvesting and decreasing the water consumption per each cycle (Kiran et al. 2014). In terms of conversion technologies, the extraction or hydrolysis of the microalgal carbohydrate content into reducing sugars involves different types of physical, chemical and biological approach. Chemical hydrolysis approach generally results in the formation of high concentration of reducing sugars, but usually limited by the production of many inhibitory compounds which have negative effects on the growth of fermentative organisms and results in lower produc-

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tion of desired end products (Miranda et al. 2012). A more environmentally friendly approach such as enzymatic hydrolysis is currently attracting many researchers in the field due to its advantages over the physical and chemical methods such as mild hydrolysis conditions and no formation of inhibitory compounds. Nevertheless, enzymatic hydrolysis still has very significant weakness which comes from the high cost of enzymes as well as inactivation of enzymes in the presence of solvents and other physical parameters (Pancha et al. 2016). Overall, when discussing the economical aspect of microalgal-based bioethanol, the total production cost is the major indicator that determines its feasibility for commercialization. Figure 10 shows the production cost of bioethanol from microalgae including the cost for feedstock, capital, operation and total production cost. This clearly shows that the cost is high per unit of production. Generally, it can be stated that the entire production processes are very expensive when compared with the energy extraction from fossil fuels. The research also basically still in the progressing state in which no significant established technologies have been developed. Throughout the production processes, the cost will certainly increase exponentially starting from the initial capital for feedstock cultivation followed by the electrical equipment, storage, and transportation to move supplies from one area to the next. The conversion technologies together with the distribution of the products also need significant financial sources to aid its penetration into the market. All these disadvantages eventually urge for more intense research and initiatives from all parties to come out with solutions which can bring maturity into the bioethanol industries. A lot of efforts have been made especially for algal fuel companies for the past several years where not even a single commercial facility has come to reality. Only persistent technologies that are able to produce bioethanol in very large scale and at very low cost are expected to open a new dimension in the bioethanol industry (John et al. 2011). In this case, most of the suggested solutions regarding the minimization of production cost simply to reduce the number of steps in biofuel production so that its efficiency can be boosted. Origin Oil Ltd., is an example of biofuel company which has taken the prior initiative by developing a systematic process that is able to reduce the cost where the harvesting and extraction of feedstocks are combined into a single process (Kiran et al. 2014). In future, more advanced and realistic production processes are longed for addressing the economic limitation faced by the bioethanol world.

7 Conclusion The superior features of microalgae especially Chlorella sp. Because of its high carbohydrate content is critically important to be employed for bioethanol production. The chemical approach for the hydrolysis of the carbohydrate content using acid is an efficient method due to short reaction time as well as high recovery of reducing sugars. In this study, the critical parameters for acid hydrolysis and bioethanol fermentation from microalgae Chlorella sp. were optimized. The Chlorella sp. was

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Fig. 10 The production cost of microalgal-based bioethanol (Jambo et al. 2016)

cultivated in Jaworski’s Medium (JM) cultivation to observe the optimum growth of the microalgae so that the most suitable period to harvest the cell can be determined. From the observation, day 6–15 were found to be the best time for harvesting. Among the different conditions studied, acid hydrolysis carried out under the condition of 2.0 M sulphuric acid and 130 °C for 30 min gave the highest concentration of glucose which was 5.382 ± 0.063 g/l. Hence, these conditions are said to be the optimum condition for acid hydrolysis of microalgae Chlorella sp. On the other hand, yeast cell growth monitoring is also crucial to determine the exponential phase of the yeast cells as the maximum rate of cell division was achieved during this phase. Subsequently, during this phase, it is expected that it permits the maximum utilization of available glucose in the hydrolysate so that maximum ethanol yield could be achieved. Experimental results showed that the most optimum growth of yeast cells can be observed between 6 and 15 h. During this period, the yeast cells are most suitable to be harvested for the fermentation process. Among the different yeast inoculum concentrations used in the fermentation process, 15% v/v showed the highest ethanol concentration and ethanol yield which were 1.126 g/l and 0.209 g/g glucose, respectively. The time course of bioethanol fermentation was also studied by collecting the samples at different period of time. A duration of 24 h was found to be the optimum for maximum bioethanol production with ethanol concentrations of 1.020 g/l and ethanol yield of 0.190 g/g glucose. In a nutshell, this study provides new information especially on the laboratoryscale bioethanol production from microalgae Chlorella sp. Future research can be conducted by using immobilized yeasts in the fermentation processes to improve the

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bioethanol yield. Besides, enzymatic hydrolysis can be carried out on microalgae Chlorella sp. to identify its effect in terms of concentration of extracted glucose.

References Asaduzzaman, M. (2007). Standardization of yeast growth curves from several curves with different initial sizes. Thesis of the Degree of Master of Science, Chalmers University of Technology and Goteborg University. Atidiya, H. B., Sing, K. P., Hanif, M., & Mahlia, T. M. I. (2015). Effect of acid pretreatment of enzymatic hydrolysis in bioethanol production from rice straw. International Journal of Technology, 1, 3–10. Ajani, A. O., Agarry, S. E., & Agbede, O. O. (2011). A comparative kinetic study of acidic hydrolysis of wastes cellulose from agricultural derived biomass. Journal of Applied Science and Environmental Management, 15(4), 531–537. Brownbridge, G. Azadi, P. Smallbone, A. Bhave, A. Taylor, B.J., & Kraft, M. (2013). Algae under uncertainty: the future of the algal biodiesel economy. Cambridge Centre for Computational Chemical Engineering, 1–23. ISSN 1473 – 4273. Brownbridge, G., Azadi, P., Smallbone, A., Bhave, A., Taylor, B. J., & Kraft, M. (2014). The future viability of algae-derived biodiesel under economic and technical uncertainties. Bioresource Technology, 151, 166–173. Burlew, J. S. (Ed.). (1976). Algal culture: From laboratory to pilot plant. USA: Carnegie Institution of Washington. Chia, S. R., Ong, H. C., Chew, K. W., Show, P. L., Phang, S. M., Ling, T. C., et al. (2018). Sustainable approaches for algae utilization in bioenergy production. Renewable Energy, Part B, 129, 838–852. Chen, R., Yue, Z., Deitz, L., Liu, Y., Mulbry, W., & Liao, W. (2012). Use of an algal hydrolysate to improve enzymatic hydrolysis of lignocellulose. Bioresource Technology, 108, 149–157. Cho, Y., Kim, H., & Kim, S. (2013). Bioethanol production from brown seaweed, Undaria pinnatifida, using NaCl acclimated yeast. Bioprocess and Biosystems Engineering, 36, 713–719. Driver, T., Bajhaiya, A., & Pittman, J. K. (2014). Potential of bioenergy production from microalgae. Current Sustainable/Renewable Energy Reports, 1, 94–103. ExxonMobil. (2014). The outlook for energy: A View to 2040. Retrieved August 8, 2016, from, http://cdn.exxonmobil.com/~/media/Reports/Outlook%20For%20Energy/2015/2015Outlookfor-Energy_print-resolution.pdf. Fogg, G. E., & Thake, B. (1987). Algal culture and phytoplankton ecology (3RD ed.). USA: The University of Wisconsin Press. Forssberg, B. (2010). Opportunities: biogas, the greenest and cleanest renewable fuel. Reviews in Environmental Science & Biotechnology, 9, 307–309. Fu, C., Hung, T., Chen, J., Su, C., & Wu, W. (2010). Hydrolysis of microalgae cell walls for production of reducing sugar and lipid extraction. Bioresource Technology, 101, 8750–8754. Gibdons, W. R., & Westby, C. A. (1986). Effects of inoculum size on solid-phase fermentation of fodder beets for fuel ethanol production. Applied and Environmental Microbiology, 52, 960–962. Guo, H., Daroch, M., Liu, L., Qiu, G., Geng, S., & Wang, G. (2013). Biochemical features and bioethanol production of microlalgae from coastal waters of Pearl River Delta. Bioresource Technology, 127, 422–428. Harun, R., Danquah, M., & Forde, G. M. (2010). Microalgal biomass as a fermentation feedstock for bioethanol production. Journal of Chemical Technology & Biotechnology, 85, 199–203. Harun, R., & Danquah, M. K. (2011a). Enzymatic hydrolysis of microalgal biomass for bioethanol production. Chemical Engineering Journal, 168, 1079–1084.

Microalgae Chlorella as a Sustainable Feedstock …

101

Harun, R., & Danquah, M. K. (2011b). Influence of acid pre-treatment on microalgal biomass for bioethanol production. Process Biochemistry, 46(1), 304–309. Held, P. (2010). Monitoring growth of beer brewing strains of Saccharomyces cerevisiae. http:// www.biotek.com/assets/tech_resources/SynergyH1_Yeast_Growth_App_Note.pdf. Hernández, D., Riaño, B., Coca, M., & García-González, M. C. (2015). Saccharification of carbohydrates in microalgal biomass by physical, chemical and enzymatic pre-treatments as a previous step for bioethanol production. Chemical Engineering Journal, 262, 939–945. Ho, S., Huang, S., Chen, C., Hasunuma, T., Kondo, A., & Chang, J. (2013a). Bioethanol production using carbohydrate-rich microalgae biomass as feedstock. Bioresource Technology, 135, 191–198. Ho, S., Li, P., Liu, C., & Chang, J. (2013b). Bioprocess development on microalgae-based CO2 fixation and bioethanol production using Scenedesmus obliquus CNW-N. Bioresource Technology, 145, 142–149. Ho, S., Ye, X., Hasunnuma, T., Chang, J., & Kondo, A. (2014). Perspectives on engineering strategies for improving biofuel production from microalgae–A critical review. Biotechnology Advances, 32, 1448–1459. Hong, L. S., Ibrahim, D., & Omar, I. C. (2013). Effect of physical parameters on second generation bio-ethanol production from oil palm frond by Saccharomyces cerevisiae. BioResources, 8(1), 969–980. John, R. P., Anisha, G. S., Nampoothiri, K. M., & Pandey, A. (2011). Micro and macroalgal biomass: a renewable source for bioethanol. Bioresource Technology, 102, 186–193. Jambo, S. A., Abdulla, R. Mohd, Azhar, S. H., Marbawi, H., Gansau, J. A., & Ravindra, P. (2016). A review on third generation bioethanol feedstock. Renewable and Sustainable Energy Reviews, 65, 756–769. Kim, H., Ra, C. H., & Kim, S. (2013). Ethanol production from seaweed (Undaria pinnatifida) using yeast acclimated to specific sugars. Biotechnology and Bioprocess Engineering, 18, 533–537. Kirrolia, A., Bishnoi, N. R., & Singh, R. (2013). Microalgae as a boon for sustainable energy production and its future research and development aspects. Renewable and Sustainable Energy Reviews, 20, 642–656. Kiran, B., Kumar, R., & Deshmukh, D. (2014). Perspectives of microalgal biofuels as a renewable source of energy. Energy Conversion and Management, 88, 1228–1244. Klein, B. C., Chagas, M. F., Junqueira, T. L., Rezende, M. C. A. F., Cardos, T. F., Cavalett, O., et al. (2018). Techno-economic and environmental assessment of renewable jet fuel production in integrated Brazilian sugarcane biorefineries. Applied Energy, 209, 290–305. Laopaiboon, P., Thani, A., Leelavatcharamas, V., & Laopaiboon, L. (2009). Acid hydrolysis of sugarcane bagasse for lactic acid production. Bioresources Techonology, 101(3), 1036–1043. Lange, N., & Steinbüchel, A. (2011). B-carotene production by Saccharomyces cerevisiae with regard to plasmid stability and culture media. Applied Microbiology and Biotechnology, 91, 1611–1622. Lee, C. G., Choi, W. Y., Kang, D. H., & Lee, H. Y. (2014). Simultaneous production of biodiesel and bioethanol through mixotropic cultivation of Chlorella sp., Indian J Geo-Marine Sci, 43(10), 519–528. Leupold, M., Hindersin, S., Gust, G., Kerner, M., & Hanelt, D. (2013). Influence of mixing and shear stress on Chlorella vulgaris, Scenedesmus obliquus, and Chlamydomonas reinhardtii. Journal of Applied Phycology, 25, 485–495. Liu, G., Qiao, L., Zhang, H., Zhao, D., & Su, X. (2014a). The effects of illumination factors on the growth and HCO-3 fixation of microalgae in an experiment culture system. Energy, 78, 40–47. Liu, J., Sun, Z., & Gerken, H. (Eds.). (2014b). Recent Advances in Microalgal Biotechnology. USA: OMICS Group. Makareviˇcien˙e, V., Andruleviˇci¯ut˙e, V., Skorupskait˙e, V., & Kasperoviˇcien˙e, J. (2011). Cultivation of microalgae Chlorella sp. and Scenedesmus sp. as a potentional biofuel feedstock. Environmental Research, Engineering and Management, 3(57), 21–27.

102

R. Abdulla et al.

Mansa, R. F., Chen, W., Yeo, S., Farm, Y., Bakar, Hafeza Abu, & Sipaut, C. S. (2013). Fermentation study on macroalgae Eucheuma cottonii for bioethanol production via varying acid hydrolysis. Advances in biofuels (pp. 219–239). New York: Springer Science + Business. Markou, G., Angelidaki, I., Nerantzis, E., & Georgakakis, D. (2013). Bioethanol production by carbohydrate-enriched biomass of Arthrospira (Spirulina) platensis. Energies, 6, 3937–3950. Manzoor, A., Khokhar, Z., Hussain, A. Uzma, Ahmad, S. A., Syed, Q., & Baig, S. (2012). Dilute sulfuric acid: A cheap acid for optimization of bagasse pretreatment. Science International (Lahore), 24(1), 41–45. Medawar, W., Strehaiano, P., & Delia, M. (2003). Yeast growth: Lag phase modeling in alcoholic media. Food Microbiology, 20, 527–532. Minh, N. P., & Dao, D. T. A. (2013). Investigation of Saccharomyces cerevisiae in fermented mulberry juice. International Journal of Science & Technology Research, 2(11), 329–338. Miranda, J. R., Passarinho, P. C., & Gouveia, L. (2012). Pre-treatment optimization of Scenedesmus obliquus microalga for bioethanol production. Bioresource Technology, 104, 342–348. Mohr, A., & Raman, S. (2013). Lessons from first generation biofuels and implications of the sustainability appraisal of secondary generation biofuels. Energy Policy, 63, 114–122. Mutripah, S., Meinita, M. D. N., Kang, J., Jeong, G., Susanto, A., Prabowo, R. E., et al. (2014). Bioethanol production from the hydrolysate of Palmaria palmate using sulfuric acid and fermentation with brewer’s yeast. Journal of Applied Phycology, 26, 687–693. Naik, S. N., Goud, V. V., Rout, P. K., & Dalai, A. K. (2010). Production of first and second generation biofuels: A comprehensive review. Renewable and Sustainable Energy Reviews, 14, 578–597. Pancha, I., Chokshi, K., Maurya, R., Bhattacharya, S., Bachani, P., & Mishra, S. (2016). Comparative evaluation of chemical and enzymatic saccharification of mixotrophically grown de-oiled microalgal biomass for reducing sugar production. Bioresource Technology, 204, 9–16. Pienkos, P., & Darzins, A. (2009). The promise and challenges of microalgal-derived biofuels. Biofuels, Bioproducts and Biorefining, 3, 431–440. Proskurina, S., Junginger, M., Heinimö, J., Tekinel, B., & Vakkilainen, E. (2018). Global biomass trade for energy— Part 2: Production and trade streams of wood pellets, liquid biofuels, charcoal, industrial roundwood and emerging energy biomass. Biofuels, Bioproducts and Biorefining. https://doi.org/10.1002/bbb.1858. da Ribeiro, L. A., Silva, P. P., Mata, T. M., & Martins, A. A. (2014). Prospects of using microalgae for biofuels production: results of a Delphi study. Renewable Energy, 75, 799–804. Salar, R. K., Gahlawat, S. K., Siwach, P., Duhan, J. S. (Eds.). (2013). Biotechnology: Prospects and applications. India: Springer. Sarkar, N., & Aikat, K. (2013). Kinetic study of acid hydrolysis of rice straw. The Scientist World Journal, 2013, 1–8. Saucedo-Luna, J., Castro-Montoya, A. J., Rico, J. L., & Campos-Garcia, J. (2010). Optimization of acid hydrolysis of bagasse from Agave tequilana Weber. Revista Mexicana de Ingeniería Química, 9(1), 91–97. Scholz, M. J., Riley, M. R., & Cuello, J. L. (2013). Acid hydrolysis and fermentation of microalgal starches to ethanol by the yeast Saccharomyces cerevisiae. Biomass and Bioenergy, 48, 59–65. Sevda, S. B., & Rodrigues, L. (2011). Fermentative behavior of Saccharomyces strains during guava (Psidium guajava L) must fermentation and optimization of guava wine production. Journal of Food Processing & Technology, 2(4), 1–9. Talukder, M. M. R., Das, P., & Wu, J. C. (2012). Microalgae (Nannochloropsis salina) biomass to lactic acid and lipid. Biochemical Engineering Journal, 68, 109–113. Thenmozhi, R., & Victoria, J. (2013). Optimization and improvement of ethanol production by the incorporation of organic wastes. Advances in Applied Science Research, 4(5), 119–123. Tuantet, K., Janssen, M., Temmink, H., Zeeman, G., Wijffels, R. H., & Buisman, C. J. N. (2014). Microalgae growth on concentrated human urine. Journal of Applied Phycology, 26, 287–297. Wan, C Md, Alam, Asraful, Zhao, X. Q., Zhang, X. Y., Guo, S. L., Ho, S. H., et al. (2015). Current progress and future prospect of microalgal biomass harvest using various flocculation technologies. Bioresource Technology, 184, 251–257.

Microalgae Chlorella as a Sustainable Feedstock …

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Wang, H., Ji, C., Bi, S., Zhou, P., Chen, L., & Liu, T. (2014). Joint production of biodiesel and bioethanol from filamentous oleaginous microalgae Tribonema sp. Bioresource Technology, 172, 169–173. Yu, M., Li, J., Chang, S., Du, R., Li, S., Zhang, L., et al. (2014). Optimization of ethanol production from NaOH-pretreated solid state fermented sweet sorghum bagasse. Energies, 7, 4054–4067. Zhou, N., Zhang, Y., Wu, X., Gong, X., & Wang, Q. (2011). Hydrolysis of Chlorella biomass for fermentable sugars in the presence of HCl and MgCl2 . Bioresource Technology, 102, 10158–10161.

Conversion of Landscape Waste into Bio-coke Solid Fuel Santhana Krishnan, Mohd Fadhil Md Din, Shazwin Mat Taib, Norfarah Hanim Binti Kamaludin, Norhisyam Hanafi, Tamio Ida, Mohd Suhaizan Shamsuddin and Shreeshivadasan Chelliapan

Abstract A rapid increase in organic wastes requires an integrated management system that enhances the use of such wastes to achieve sustainable waste management. Among that, landscape waste is an organic yard or garden waste such as leaves and plant trimmings (excluded grass clippings, sod and dirt). The landscape wastes that are dumped or buried in the landfill takes a period of time to decompose but the wastes are increasing from day to day. This research was aimed to study on the abandon landscape waste at the landscape landfill in Universiti Teknologi Malaysia (UTM); the pattern of landscape wastes generation in each zone in UTM region; and the suitable evaluation using bio-coke as a new treatment option to treat the landscape wastes. Landscape waste collection form was distributed to all the contractors in each zone to collect the data of the five types of waste; dry leaves, twigs, branches, palm front, and wood. The data analysis obtained show that the dry leaves are the major landscape waste at the UTM landscape landfill which was left abandoned without proper treatment. Finally, the empty fruit bunch (EFB) and dry leaves (combined in S. Krishnan · M. F. M. Din (B) Center of Environmental Sustainability and Water Security (IPASA), Research Institute of Sustainable Environment (RISE), Universiti Teknologi Malaysia UTM, 81310 Johor Bahru, Johor, Malaysia e-mail: [email protected] S. Krishnan · M. F. M. Din · S. M. Taib · N. H. B. Kamaludin Department of Environmental Engineering, Faculty of Civil Engineering, Universiti Teknologi Malaysia UTM, 81310 Johor Bahru, Johor, Malaysia M. F. M. Din · S. M. Taib · N. Hanafi Campus Sustainability Office, Universiti Teknologi Malaysia UTM, 81310 Johor Bahru, Johor, Malaysia T. Ida Kinki University, Higashiosaka, Japan M. S. Shamsuddin Office of the Asset and Development, Universiti Teknologi Malaysia UTM, 81310 Johor Bahru, Johor, Malaysia S. Chelliapan Department of Engineering, Razak Faculty of Engineering and Informatics, Universiti Teknologi Malaysia, Jalan Sultan Yahya Petra, 54100 Kuala Lumpur, Malaysia © Springer Nature Singapore Pte Ltd. 2020 A. Z. Yaser (ed.), Green Engineering for Campus Sustainability, https://doi.org/10.1007/978-981-13-7260-5_8

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a three different aspect ratio of 90:10, 50:50, 0:100) were pyrolyzed at a highly compressed state and at moderate temperature (160 °C). The calorific analyses revealed that bio-coke (Product 1, Product 2, Product 3) had an energy density of 17520.7 J/g, 17338 J/g, and 17186.6 J/g, respectively. Conversion of the landscape waste into solid fuel; bio-coke is the best way to treat the abandon landscape waste.

1 Introduction Nowadays, the rapid development pace in our country, especially in the capitals, has encouraged new buildings to be erected everywhere. In addition, an increase in population growth rate and huge economic activities in urban areas cause an increase in the waste generation as a by-product of these civil developments (Peters and Luengen 2011). Landscape waste also includes green or garden waste materials such as branches, bushes and tree stumps. Although the development destroys the landscape, the aim to be a sustainable development country is not forgotten and developers must promote the initiative to treat the landscape wastes. The amount of landscape waste at landfills increases from year to year. To overcome the problem of uncontrolled dumping of waste, people burn the waste frequently and this method is not environmental-friendly. The landscape wastes that dump or buried in the landfill take a period of time to decompose but the wastes are increasing from day to day. Processing and recycling landscape waste will extend the life of the landfill by 20 years (Lauri et al. 2014). The landfill life will be shortened and next, it will no longer handle the increasing the amount of the wastes. Furthermore, there is also a problem in agricultural landfills which are the best places for insects such as Isoptera (termites) and Diptera (mosquito) groups to thrive. These sites are also a breeding ground for rats. They can cause serious diseases such as Dengue (caused by mosquitoes) and Leptospirosis (caused by rats). There is a general lack of awareness towards sustainable management of landscape wastes. The maturity of the trees is the main factor that contributes to the landscape wastes generation. Although recycling activities have been growing in recent years, landscape waste has been a largely ignored source. Landscape waste can be valuable by converting them into solid fuel. The steps taken to produce a final output such as bio-coke are the best choice for sustainable waste management (Mizuno et al. 2011). The production of bio-coke is performed by mixing landscape waste with dry leaves, twigs, branches, woods and palm trees. In addition to bringing economic values, biocoke also helps in minimizing the amount of landscape waste that is being dumped into landfills and increasing the amount of the wastes due to ever growing of the trees will cause the wastage of the landfill area uses to dump the landscape wastes. The study on conversion of landscape wastes into bio-coke solid fuel will determine either it can be one of the solutions to treat the wastes. There are not enough biomass utilization technologies to simultaneously achieve the two targets: the utilization of about 80% waste biomass and 6 percent reduction in the amount of carbon dioxide (CO2 ) emissions. Thus, it is a necessity to develop

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new technologies aimed at the utilization of unused biomass as energy and fuels to solve the problems of emission control of waste biomass and CO2 emissions reduction (Mizuno et al. 2015). Bio-coke is classified as a solid fuel because it is a solid material which is compatible with fuel utilization to provide thermal energy and to generate electric power. Bio-coke, as a sustainable biomass-derived carbonaceous solid fuel, is characterized by low sulphur content, high feedstock availability and has an economically efficient production process (Murata et al. 2014). Hence, the characteristics are attributed to bio-coke’s production route of biomass pyrolysis (Montiano et al. 2014a), which is an irreversible process in which organic materials undergo thermochemical decomposition at an elevated temperature with the absence of oxygen. It is one of the environmental-friendly product that made up from the wood wastes which is that is suitable to be replaced and can be used in the industries that use coal as their energy to burning and it really suitable especially for metallurgical industries. Production demonstration trials have shown that applicable raw materials include used tea leaves, used ground coffee, rice husks, swine manure, wood waste (konara oak, cherry tree), sawdust, tree bark, apple peel, banana peel, distillery waste, soymeal, and reeds (Montiano et al. 2014b). Therefore, this chapter deals with the identification the pattern of landscape wastes generation in each zone in UTM region and evaluate the suitability using bio-coke production as a new treatment option to treat the landscape wastes in order to justify either final product, bio-coke meets the solution of the landscape wastes. This empirical evidence that with a sustainable treatment of landscape wastes can and will help UTM in decreasing its landscape waste generation. The total area of study is 1222 hectare. The selection of UTM as the study area is because there is a huge amount of landscape waste being dumped to landfills and the data on this dumping is not recorded. This study will cover five out of eight main landscapes wastes which are palm fronds, branches, dry leaves, tree branches, and twigs. These groups of wasted are characterized according to their type and size. The collected dry leaves from the UTM were mixed in different ratios (10, 50, 90%) with the palm oil empty fruit bunches (EFB) and bio-coke was produced and the energy density was determined (Fig. 1).

2 Methods 2.1 Landscape Waste Collection The collection of landscape wastes is done daily with as much as two trips for some cleaning zones. Collection forms were distributed to all contractors for the eleven zones and they are required to complete the form and give back to the person in charge in the office of the assets and development. Lorries weighing three tonnes are used to collect landscape waste. The contractors used a weighting scale to estimate the weight for each gunny sacks containing dry leaves, while other landscape wastes

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Fig. 1 Bio-coke product from palm leaves

such twigs, branches, palm frond, and wood are directly loaded into the lorry. The weight of each gunny sacks will be estimated by the contractors by taking the average weight of the dry leaves in the gunny sacks.

2.2 Waste Generation Zones Landscape waste in UTM was collected by the cleaning contractors in each zone and directly dumps the landscape waste to the landscape landfill at UTM. Figure 2 shows the region size for each zone for the year 2015 and 2016. UTM area is divided into eleven zones. The location (L) of the landscape landfill is at L1. L1 to L11 stands for Location 1 to location 11. This helps to know the distribution and the types of landscape waste for each zone and focus more on the zone that produces high percentage on dry leaves because the dry leaves will be used for making bio-coke.

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Fig. 2 Area of UTM cleaning zone

3 Bio-coke Production 3.1 Process Flow The most important tool is the machine to produce bio-coke. The factory location is located at Gelang Patah, Johor, Malaysia. There are several steps taken during the processing the landscape wastes in order to produce the final output product (Fig. 3). The dry leaves will be ground and shredded and the leaves shoul be dry first before shredding and grinding. Additionally, several attributes of the landscape

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Fig. 3 Flow processing of bio-coke

wastes such as level of moisture will be considered in the production of bio-coke because landscape waste must be void of moisture to be eligible in being used for bio-coke production. Later, the dry leaves will be put into the compressor machine and it will be compressed at higher pressure until it becomes solid form.1 . 1 Handle

by Kinki University and Osaka Gas.

Conversion of Landscape Waste into Bio-coke Solid Fuel Table 1 Chemical constituents of palm oil empty fruit bunches

Elemental analysis

111

Wt. (%)

Cellulose

59.1

Hemicellulose

21.8

Lignin

17.9

Carbon

47.2

Hydrogen

6.5

Nitrogen

0.9

Sulphur

0.3

Oxygen

37.1

Potassium

2.6

Moisture

8.21

Volatiles

74.7

Ash

4.5

Fixed carbon

18

High heat value (MJ/kg)

18.9

Low heat value (MJ/kg)

17.4

3.2 Biomass Characterisation Two different biomass samples were pyrolyzed: empty fruit bunches and dry leaves and the EFB was obtained from the palm oil mill located at FELDA Bukit Besar, Kulai, and Johor. The composition of the raw biomass is shown in Table 1. The EFB and dry leaves were collected and dried at sunlight for 4 days and ground into a fine powder of 200 µm. Both the EFB and dried leaves were mixed in the defined ratio and bio-coke was prepared. The Elemental composition of the raw EFB was determined according to the ASTM standard E711-87 (Demirbas 1997).

3.3 Pyrolysis Process EFB and dry leaves are pyrolyzed at 160 °C for at least 2 h to obtain char and pyrolysis liquid needed. Char is prepared as a main source for the bio-coke mixture, meanwhile, the pyrolysis liquid acts as the binder. The char and pyrolysis liquid at 70:30 was maintained for three different EFB to dry leaves proportion of biomass 90:10, 50:50 and 0:100. 10 g of cassava starch was added as a binder agent. The defined parameters and range during the operation is given in Table 2. Calorific value was measured by using IKA C 2000 calorimeter Bomb calorimeter according to ASTM standard E711-87.

112 Table 2 Operating conditions of the Instrument

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Parameters

Range

Mixing ratio (EFB:Dry Leaves)

90:10, 50:50, 0:100

Cutting Wt.

53.5 kg

Crusher Wt.

27.5 kg

Leaf Wt.

9 kg

Cutting H2 O%

7.50%

Crusher H2 O%

8.86%

Combined H2 O%

9.74%

Machine

Compression reactor

Pressure

21 MPa

Retention time

120 min

Pyrolysis temp

160 °C

4 Result and Discussion 4.1 Landscape Waste Management Figures 4 and 5 show the average of two daily trips of landscape waste collected by the contractor. There are seven zones requiring two trips of landscape waste collection while four zones- 3, 8, 9, and 10—require only one trip of landscape wastes collection daily. The first trip of the collection of dry leaves shows that the highest percentage belongs to zone 8 with 93% and the lower percentage of dry leaves collection is zone 2 with 58%. Next composition of landscape wastes is twigs. The highest percentage which is 29% belongs to zone 1, while the lowest percentage of twigs are zones 8, 9, and 11 with 8% of wastes. For branches, zone 7 shows the highest percentage (11.4%) compared to other zones and the lowest percentage of branches collected is zone 6 with 6.4%. Palm frond with 43% in zone 11 is the highest percentage compared to other zones and the lower percentage in zone 8 with 6% of palm frond waste collection. The last composition in landscape wastes is wood. The highest percentage of waste collection is zone 2 with 12% of wood and the lowest is zone 4 with 2% of wood. The second trip is performed only on seven zones. This is because the landscape wastes for zones 3, 8, 9, and 10 are already all collected on the first trip. In this trip, zone 4 shows the highest percentage collection of dry leaves with 98% of the collection while zone 2 is the lowest with 55% of the collection of dry leaves. For twigs, the highest percentage collection belongs to zone 7 with 20% and zone 11 has the lowest collection with 5% only. Next landscape wastes composition is the branches. This landscape waste composition will be compared among five zones only which are zone 1, 2, 4, 5, and 6. Zone 6 shows the highest percentage (15%) among all zones and zone 1 shows the lowest collection with 0.9% compared to other zones. For palm frond, the difference in collection amount among zones is small.

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Fig. 4 Average daily first trip collected by the contractors for each zone

Fig. 5 Average daily second trip collected by the contractors for each zone

The highest percentage collection is 11% that belongs to zone 5 and zone 7. While the lowest collection is zone 4 with 5% collection only. The last landscape waste composition is wood. This trip collection will be compared among three zones only which are zone 1, 2 and 5 only. The highest collection with 10% is zone 2 while the lowest collection is zone 1 with 0.9% only. The pattern of landscape wastes between the trips is difficult to understand and to compare to determine which zone has the highest percentage of each composition of landscape wastes. Table 3 below shows the average of the daily collection of landscape wastes for each composition in eleven zones in UTM. It also includes the number of gunny sack of dry leaves. The average weight of a fully filled gunny sack is about 6 kg. There is some problem where not all the contractors contribute their collection data. In this study, zones 8, 10, 11 have no data on how much gunny sack have been collected daily in UTM. Table 3 shows the percentage of a daily number of gunny sacks containing dry leaves on eight zones only. The contractors responsible for collection in zone 8, 9,

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Table 3 Total average daily landscape wastes collection Average trip Zone

Dry leaves (%)

Gunny sacks

Twigs (%)

Branches (%)

Palm frond (%)

Wood (%)

1

74

32.5

2

57

47.75

20

9.35

11

10

13

11

10

11

3

30

4

93

12.5

5

5

5

5

44.5

12

5

7

5

1

82

35.5

11

9.30

11

8

6

90

54.5

9

10.70

8

7

89

32

15

5.70

13

8

47

4 24

3

3

9

35

4

4

5

10

44

6

5

4

11

76

7

3

26

and 11 did not comply with the regulation requiring them to complete the collection form, hence the missing data for these regions. So here, we can see the analysis that has been done on eight zones only. From the result obtained, we can conclude that the highest number of gunny sack monopoly among eight zones is 54.4 gunnies from zone 6, followed by zone 2 with 47.75 gunnies. There are three zones with a small difference in the number of gunnies, which are zone 1, 5 and 7. The lowest number of gunny sacks is zone 3 with only 12.5 gunnies per day. The average weight of gunny sack, if we weigh each gunny sack, is around 6 kg per gunny.

4.2 Bio-coke as New Treatment Option to Treat Landscape Wastes After collecting and analysing the data, the next step is transporting the landscape waste to the bio-coke factory for processing the raw material (landscape waste) into bio-coke. From the estimation transporting the landscape waste to the bio-coke factory, we can know that the volume that we can supply daily from UTM landscape landfill to the bio-coke factory. Table 4 below shows the estimation daily weight of dry leaves that can be transported to the bio-coke factory. From this estimation, we can supply about 1.7 tonnes dry leaves to the bio-coke factory as an alternative to treat landscape waste every day. Thus, from this method, we can minimize the amount of landscape waste at the UTM landscape landfill.

Conversion of Landscape Waste into Bio-coke Solid Fuel Table 4 Average weight daily landscape waste

115

Zone

Dry leaves (%)

Gunny sacksa

1

74

32.5

195

2

57

47.75

285.5

3

30

12.5

75

4

93

44.5

267

5

82

35.5

213

6

90

54.5

327

7

89

32

192

8

47

–

–

Weight (kg)

9

35

24

144

10

44

–

–

11

76

–

–

Total a Average

1698.5 kg 1 gunny sack estimated by the contractors = 6 kg

4.3 Bio-coke Production and Analysis The bio-coke was prepared using different ratios of EFB to dry leaves ratio such as 90:10, 50:50 and 0:100 (Fig. 7). After pyrolysis, the biomass showed an increase in carbon content and it is attributed to the great influence of dehydration, which also makes a slight reduction of hydrogen content indicating that the bio-coke produced at moderate temperature was pyrolyzed more thoroughly (Yang et al. 2016). The products, generated by the polymerization of these radicals and precursor which is formed by the macro-molecules cracking, deposit on the EFB: dry leaves bio-coke leading to an increase in C and H content. It is ascribed that the large amount of dehydration which reduces the chemical bonds resulting in an increase in the relative proportion of oxygen-free functional groups (Montiano et al. 2014c). Among the three products, Product 1 (i.e. 90:10) was found to have slightly higher calorific value than the other two products. The calorific content of product 1 was found to have 17357.5 J/g, while product 2 and product 3 had an average caloric value of 17338 J/g and 17186.6 J/g, respectively. There are many factors influencing a pyrolysis process such as effect of particle size, heating rate and the properties of biomass itself. The results of the calorific content of bio-coke are given in Table 5. The calorific value was also declined from EFB: Dry Leaves ratio of 90:10 to 100% leaves bio-coke. The higher heating value of product 1 could be attributed to the low resistance of hemicellulose toward thermal degradation and also depends on moisture and ash content (Suopajärvi et al. 2018). According to Suhartini et al., the calorific value of fuel bio-coke is directly proportional to the removal of volatile matter and moisture content. High volatile matter content of the biomass makes it contribute more fractional heat, and, consequently, make it more reactive than coal. Thus, biomass solid fuel has a faster combustion rate during the

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Fig. 7 Bicoke produced from three different ratios of dry EFB: dry leaves

devolatization process which makes it easy to ignite and burn (Suhartini et al. 2011). Parikh et al. (2005) and Yin (2011) discovered a quick and economical method for the estimation of calorific value by correlating heating value with proximate analyses data. By estimating high heating value (HHV) on a dry basis, both studies used large data points of agricultural wastes. Parikh et al. (2005) stated that the algebraic expression of theoretical heating value calculation is applicable for all kinds of solid fuel including biomass materials.

4.4 Economic Analysis The potential demand for bio-coke in furnaces is estimated at 200,000–300,000 tonnes a year. It is estimated that the plan, which will produce bio-coke from biomass (EFB from palm oil mills), will need an initial investment of 15 million RM (in the case of EFB) as well as a total of 15 employees. Of the annual output of 3,330 tonnes,

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Table 5 Calorific values of bio-coke with three different ratios of dry EFB to dry leaves S. no.

Product

Pyrolysis temp (°C)

Ignition energy (J)

Extraneous energy (J)

Weight (g)

Calorific values (J/g)

1

Product 1

160

70

50

0.51

17357.5

160

70

50

0.51

17338

160

70

50

0.51

17186.6

(90% dry EFB 10%, leaf) 2

Product 2 (50% dry EFB, 50% leaf)

3

Product 3 (100% dry leaf)

Values are the mean + S.D. of the 3 observations

1,000 tonnes will be sold to foundries in Malaysia and the remaining 2,330 tonnes will be exported to foundries in Japan. Annual sales will be 100 million RM. Local palm oil mills can benefit from such a plant, which will be a steady buyer of EFB, because they have long had difficulty disposing of. This plan is thus expected to help promote local palm-related industries, which play a key role in the region. The construction of a bio-coke plant will have a good chance of being warmly accepted as in the Malaysia region.

5 Conclusions The result of the study shows that dry leaves have the highest percentage compared to four other landscape wastes within the three months period. We predict that by converting landscape waste into solid fuel, bio-coke can minimize the abandoned landscape waste at the landscape landfill. The calorific analyses revealed that biocoke had an energy density of 17520.7 J/g. From this applied technique, there are many advantages such can minimize the size of the landscape waste, control land pollution, and having an organized landscape wastes documents for future planning of landscape waste management or landscape waste control. In addition, by converting landscape wastes into solid fuel, bio-coke, we can also monetize the commercialization the bio-coke production. Good quality briquette not only acts as an alternative energy fuel, but also proves beneficial impacts for the environment. Besides, with this side income, it can replace or can minimize the other cost such transportation of landscape waste to bio-coke factory. Acknowledgements The study was collaborated by between Kindai University- Japan, Osaka Gas Co-Japan, and Universiti Teknologi Malaysia, was funded by GUP Q.J130000.2522.20H32, GUP

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Q.J130000.3022.01M12, by Research Management Centre, Universiti Teknologi Malaysia. These supports are highly appreciated.

References Demirba¸s, A. (1997). Calculation of higher heating values of biomass fuels. Fuel, 76(5):431–4. Lauri, P., Havlík, P., Kindrmann, G., Forsell, N., & Böttcher, H. (2014). Woody biomass energy potential in 2050. Energy Policy, 66, 19–31. Mizuno, S., Ida, T., & Fuchihata, M. (2011). A study of physical properties of high-density solid biomass, bio-coke, with unutilized biomass. Journal of the Japanese Society for Experimental Mechanics, 1119–1124. Mizuno, S., Ida, T., Fuchihata, M., Sanchez, E., & Yoshikuni, K. (2015). Formation characteristics of bio-coke produced from waste agricultural biomass. American Society of Mechanical Engineers. Montiano, M. G., Díaz-Faes, E., & Barriocanal, C. (2014a). Partial briquetting vs direct addition of biomass in coking blends. Fuel, 2014(137), 313–320. Montiano, M. G., et al. (2014b). Influence of biomass on metallurgical coke quality. Fuel, 2014(116), 175–182. Montiano, M. G., Diaz-Faes, E., Barriocanal, C., & Alvarez, R. (2014c). Influence of biomass on metallurgical coke quality. Fuel, 116, 175–182. Murata, H., et al. (2014). Forming properties of bio-coke using fruit peels as raw material: Effective utilization of unused biomass resources obtained from imported fruit from ASEAN countries. Journal of Smart Processing, 3(5), 276–282. Parikh, J., Channiwala, S. A., & Ghosal, G. K. (2005). A correlation for calculating HHV from proximate analysis of solid fuels. Fuel, 84(5), 487–494. Peters, M., & Luengen, H. B. (2011). Iron making in Western Europe. In Proceedings of 6th European Coke and Ironmaking Congress, METEC Insteel Congress, Düsseldorf, Germany, June 27–July 1. Suhartini, S., Hidayat, N., & Wijaya, S. (2011). Physical properties characterization of fuel briquette made from spent bleaching earth. Biomass and Bioenergy, 35(10), 4209–4214. Suopajärvi, H., Umeki, K., Mousa, E., Hedayati, A., Romar, H., Kemppainen, A., et al. (2018). Use of biomass in integrated steelmaking–Status quo, future needs and comparison to other low-CO2 steel production technologies. Applied Energy, 1(213), 384–407. Yang, H., Huang, L., Liu, S., Sun, K., & Sun, Y. (2016). Pyrolysis process and characteristics of products from sawdust briquettes. BioResources, 11, 2438–2456. Yin, C. Y. (2011). Prediction of higher heating values of biomass from proximate and ultimate analyses. Fuel, 90(3), 1128–1132.

The Effect of Enzyme Addition on the Anaerobic Digestion of Food Waste Mariani Rajin, Abu Zahrim Yaser, Sariah Saalah, Yogananthini Jagadeson and Marhaini Ag Duraim

Abstract Due to increase in the amount of food waste, the proper method to dispose food waste has become a concern. Anaerobic digestion has received increasing attention because of its advantages such as reducing waste pollution and producing clean energy. Hydrolysis, the first step in anaerobic digestion, has been identified as rate-limiting step in this process. Enzyme addition during hydrolysis of a substrate has been reported as a promising alternative to stimulate waste degradation, thus improving the efficiency of the anaerobic digestion system. In this work, Candida Antarctica Lipase B (CALB) was used to facilitate the anaerobic digestion of food waste for 40 days. The effects of lipase addition on the total organic carbon (TOC), biogas production, pH, electrical conductivity and moisture content were studied. The finding showed that the food waste digestion with lipase achieved higher reduction in pH at a shorter time, indicating a higher degradation rate when lipase was added into the system. However, lipase addition had no effect on the final values of both pH and conductivity after 40 days of digestion. It was also found that the usage of lipase in this study did not help in increasing the biogas production due to acidification of food waste during digestion that inhibited the biogas production. On the other hand, it was found that the final moisture content of 88% achieved by food waste with lipase was higher as compared to the control sample. The finding also showed that higher reduction in TOC value was achieved when lipase was added into the digestion system, showing higher degradation rate by microorganisms. The complex molecule in food waste was hydrolysed to a simple molecule assisted by the enzyme added so that it can be easily utilised by the microorganisms. Keywords Anaerobic digestion · Lipase · Hydrolysis · Physiochemical properties · Biogas

M. Rajin (B) · A. Z. Yaser · S. Saalah · Y. Jagadeson · M. Ag Duraim Chemical Engineering Programme, Faculty of Engineering, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia e-mail: [email protected] S. Saalah e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Z. Yaser (ed.), Green Engineering for Campus Sustainability, https://doi.org/10.1007/978-981-13-7260-5_9

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1 Introduction Food waste has been recorded as the largest components of waste in the world as reported by Zhang et al. (2014) and Capson-Tojo et al. (2016). Food waste is recognised as pollutants, since it readily decomposes, generates odours, and sometimes causes illness under natural condition due to its high biodegradable organic compound and moisture content (Moon and Song 2011). The amount of food waste is expected to keep increasing as the population growth and the development of worldwide economy increase (Agamuthu and Fauziah 2011). Therefore, a proper management of food waste is needed to avoid severe health problems and environmental pollution. Landfill disposal, incineration and anaerobic digestion are among the traditional methods used for food waste treatment (Polprasert 2007). However, the approaches of disposals for food waste management by landfills and incinerator have some drawbacks. Many countries fully banned the landfilling approach as well as the incinerator where it produces intensive energy to the surrounding due to the high moisture content and can cause air pollution from the release of smoke from chimneys. Moreover, incineration also decreases the economic value of the waste as it inhibits the recovery of nutrients and valuable chemical compounds from the incinerated substrate. On the other hand, the increasing number of food waste generated every year leads to insufficient area for landfill management (Kunwar et al. 2017). Thus, anaerobic digestion has been considered as an attractive alternative to overcome these limitations. Anaerobic digestion involves the degradation and stabilisation of organic materials under anaerobic conditions by microbial organisms. The degradation of organic material will lead to the formation of biogas which is a mixture of carbon dioxide and methane as renewable energy source and microbial biomass (Kelleher et al. 2002). This technology is widely applied in waste management including food waste and other organic waste treatments (Yaser 2014; Rajin 2018). Furthermore, the production of biogas from anaerobic digestion is one of the renewable energies that can be used for heating and power generation. Generally, there are four steps involved in anaerobic digestion which are hydrolysis, acidogenesis, acetogenesis and methanogenesis. Among these steps, hydrolysis is known as the rate limiting step. During hydrolysis, the polysaccharides (macronutrients) are converted into monosaccharides (micronutrients) by extracellular microbial enzymes. The slow degradation rate of crude lipid which includes floatable grease, oil and fats in the food waste leads to low digestion efficiency and therefore inhibits the digestion process. Various methods have been reported to improve the performance of anaerobic digestion system. Among them is the addition of enzymes to accelerate the hydrolysis reaction of various types of substrates as reported by Meng et al. (2017), Dors and Mendes (2013) and Kanmani et al. (2016). In these previous works, commercial enzymes such as carbohydrases, proteases, and lipases have been used to improve hydrolysis of food waste from various sources. Therefore, this research was conducted to determine the feasibility of lipase to be used in the anaerobic digestion system of Malaysian food waste. The effects of

The Effect of Enzyme Addition on the Anaerobic Digestion …

121

lipase addition on the physiochemical properties of the food waste digestate and the biogas production were also investigated.

2 Materials and Methods 2.1 Food Waste, Inoculum and Enzyme Food waste was collected from a cafeteria in the Faculty of Engineering (FKJ), Universiti Malaysia Sabah, Kota Kinabalu, Sabah. The collected food waste was sealed and stored in laboratory for further use. Inoculum was prepared through 51 days anaerobic digestion of food waste. The Candida Antartica lipase B Lipozyme (CALB L) used was purchased from Novozyme Inc. (Davis, CA) and was selected based on its ability to hydrolyse high fat content substrate.

2.2 Anaerobic Digestion of Food Waste The anaerobic digestion process was carried out by feeding 350 g of food waste into a 500 mL bottle as a batch reactor. The amount of lipase used was 0.015 g lipase/100 g of food waste. Control reactors without enzyme were also prepared. All reactors were sealed for 40 days. For each consecutive 10 days, the sample of food waste was collected for physiochemical analysis. The biogas produced from the anaerobic digestion process was collected using the water displacement method. All experiments were done in duplicates.

2.3 Physiochemical Analysis The food waste samples for days 0, 10, 20, 30 and 40 were analysed for pH, conductivity, moisture content and Total Organic Carbon (TOC). All analysis methods and calculation were adapted from Yaser et al. (2007).

2.3.1

Total Organic Carbon (TOC)

The samples were oven dried at 105 °C for 24 h. The dried samples were burned in the furnace at 550 °C for 4 h. The organic matter was determined as volatile solid. The percentage of TOC was determined by using Eq. 2.1.

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TOC (%) =

2.3.2

Organic matter (%) 100 − Ash (%) = 1.8 1.8

(2.1)

pH and Conductivity

5 g of food waste sample was oven dried at 105 °C for 24 h. The mashed food waste was mixed with 50 ml of distilled water, shaken at 130 rpm for 24 h and then filtered. The solution was analysed by using a pH meter and conductivity meter (HI 9811-5).

2.3.3

Moisture Content

The food waste was dried at 105 °C for 24 h before determining the moisture content. The initial and final mass of the mixture were recorded. The moisture content was calculated by using Eq. 2.2. Moisture content =

Initial Mass − Final Mass × 100% Initial Mass

(2.2)

3 Results and Discussions 3.1 Effect of Lipase Addition on Total Organic Carbon Figure 3.1 shows the Total Organic Carbon (TOC) profile of the digestate obtained in this work, for food waste with and without lipase. Total Organic Carbon (TOC) is used as the energy source for microorganisms during digestion process and the degradation of carbon illustrates the level of digestate maturity (Zhang et al. 2017). The decrease in total organic carbon is related to the amount of carbon dioxide released. Carbon dioxide released depends on the degree of utilisation of organic carbon through microbial degradation (Kulikowska 2016). Furthermore, the decrease in total organic carbon is related to the microbial respiration (Kulcu and Yaldiz 2004). Thus, a larger decrease in total organic carbon shows higher degradation by microorganisms. Based on Fig. 3.1, the average TOC value in this research was unsteady throughout the digestion process. Initially, the TOC decreased from 55.41 to 55.26% for food waste without lipase and 55.41–54.93% for food waste with lipase. After 20 days of digestion, the TOC for food waste without lipase slightly decreased from 55.26 to 55.04%, while the TOC increased from 54.93 to 55.15% for food waste with lipase. The TOC for food waste without lipase increased from 55.15 to 55.26% at day 40. On the other hand, the TOC for food waste with lipase decreased from 55.15 to 55.06% at day 30 and increased again from 55.06 to 55.09% at day 40. During the first 10 days, both food wastes with and without lipase showed a significant loss of total organic carbon. A high amount of organic carbon loss may

Total Organic Carbon, %

The Effect of Enzyme Addition on the Anaerobic Digestion …

55.5

Food Waste

55.4

Food Waste and Lipase

123

55.3 55.2 55.1 55.0 54.9 54.8 0

10

20

30

40

50

Time, days Fig. 3.1 TOC profiles from anaerobic digestion of food waste with and without lipase

be because of the increased degradation of biodegradable fractions in the waste. The increasing trend of TOC may be influenced by hardly degradable fractions in the food waste (Petric and Mustafi´c 2015). Furthermore, the increasing trend of organic carbon was due to the increasing population of microorganisms. As the population of microorganisms increased, the degradation process became more rapid and the degradation of the waste resulted in residue in the form of carbon source material which increased the carbon content at the end of the digestion process (Narkhede et al. 2010). Based on the results obtained, the effect of lipase addition on the TOC can be observed. After 10 days of digestion, there was a decrease in the value of TOC for both samples. However, the decrease in TOC value for the digestion of food waste with lipase was higher than the digestion of food waste without lipase. This was probably due to increase in the degradation rate of organic matter due to the addition of enzymes. Studies showed that food waste consists of macromolecules or bigger molecules such as carbohydrates, proteins and lipids. Thus, to achieve a high degradation rate, the proper enzyme needs to be supplied to the system so that the substances can be degraded easily. Additional enzymes are needed to hydrolyse the molecules into simpler substances so that they can be utilised by the microorganisms easily (Rajin 2018). It can be concluded that the addition of lipase has enhanced the degradation of organic waste. Meng et al. (2017) have also supported this finding by stating that food waste pre-treated with lipase is able to shorten the digestion time within 10–40 days and increase the methane yield.

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Volume of Gas, mL

7000 6000 5000 4000 3000 2000 1000 0 0

5

10

15

20

25

30

35

40

Time, days Food Waste

Food Waste and Lipase

Fig. 3.2 Cumulative biogas production of food waste in 40 days

3.2 Effect of Lipase Addition on Biogas Production Figure 3.2 shows the result for the cumulative volume of biogas production within the retention period of 40 days. The production of biogas increased rapidly within the first 10 days and then it decreased, as the anaerobic digestion was almost complete for both conditions. At the end of 40 days of retention period, the cumulative volume of biogas produced from food waste and food waste with lipase were 19,448 mL and 16,174 mL respectively. Theoretically, the biogas production will be higher when there is an addition of enzyme(s) into the substrate. These enzymes will help to increase the rate of degradation during the hydrolysis stage so that more biogas can be produced. However, in this study, the result showed a different trend, where it can be observed that the biogas production was higher with the absence of lipase, as shown in Fig. 3.2. Li et al. (2016) reported that there was no biogas produced in their study because the hydrolysis and acidification continued during mono-digestion of food waste, which converted the biomass particles into soluble matters. The methanogenic activity was inhibited because of high concentration of volatile fatty acid and it was related to the pH drop at the initial stage of digestion. The operational range of pH in anaerobic digesters should be between 6.6 and 7.6 with the optimum range being 7–7.2. Thus, methanogenic bacteria inhibited at such low pH (acidic), even though the acid-forming bacteria can tolerate pH as low as 5.5. The pH of a digester may drop to below 6.6 if there is an excessive accumulation of volatile fatty acids. This kind of accumulation may occur when the organic loading rates are excessively high and/or when toxic materials are present in the digester, hence producing inhibitory effects to the methanogenic bacteria as well as the biogas production (Polprasert 2007). The study from Romano et al. (2009) showed that the result for biogas production for Jose Tall Wheatgrass in a one-stage digestion configuration with enzyme product N342 differed from Domingues et al. (2015). The biogas production within the first

The Effect of Enzyme Addition on the Anaerobic Digestion … 5.5

125

Food Waste

5.3 Food Waste and Lipase

5.1 4.9

pH

4.7 4.5 4.3 4.1 3.9 3.7 3.5 0

10

20

30

40

50

Time, days

Fig. 3.3 pH profiles from anaerobic digestion of food waste with and without lipase

eight days with enzyme was higher compared to without enzyme. However, the biogas production without enzyme was higher compared to with enzyme in the last six days. Therefore, this study agreed with the findings of Romano et al. (2009) where the solid reduction was similar between the enzyme treated and non-enzyme treated systems (Higgins and Swartzbaugh 1986). Besides that, the characteristics of food waste itself which are high labile organic matter, salt, oil, protein contents, low carbon to nitrogen (C/N ratio and insufficient trace elements make anaerobic digesters prone to acidification, ammonia, salt, long chain fatty acid inhibition, and nutrient deficiency (Banks et al. 2012; Dai et al. 2013; Gao et al. 2015; Li et al. 2015; Zhang et al. 2013).

3.3 Effect of Lipase Addition on pH pH plays an important role in anaerobic digestion. Variation in pH affects the anaerobic digestion as the operation of the digester is influenced by the concentration of hydrogen ions (Ajay et al. 2011). Figure 3.3 shows the pH profile for anaerobic digestion of food waste with and without lipase. It is shown that for the first 10 days, the pH for food waste only and food waste with lipase dropped rapidly from 5.14 to 3.95 and 3.98, respectively. Past researchers stated that the pH of food waste generally lies in the acidic range which is 3.6–6.0 (Carucci et al. 2005), as obtained in the present work. The drop in the pH was due to the formation of organic acids resulted from the initial microbial degradation of food waste during anaerobic digestion (Lin 2008; Ishak et al. 2014). This finding is also supported by other researchers who stated that the initial decrease in pH value is the result of formation of organic acids such as acetic acid and butyric acid produced by the reaction of microorganisms (Yang et al. 2013).

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The data plotted in Fig. 3.3 also showed that there was further decrease in the pH reading for food waste without lipase; which was 3.98–3.86 from day 10 to day 20, then a small increase in pH was observed from day 20 to day 40. On the other hand, the pH for food waste with lipase showed a slight rise from day 20 to day 40. The subsequent rise of pH of food waste and food waste with lipase was due to the decomposition of nitrogen-containing organic matter which led to the accumulation of NH3 which dissolved in moisture to form alkaline NH4+ . Moreover, the organic acids formed were decomposed to form gaseous carbon dioxide and water. The further decomposition of fatty acids into smaller molecular acids to evaporate will also result in an increase of pH. Furthermore, mineralisation of proteins, amino acids and peptides contributes to the release of ammonium or volatile ammonia which results in the increase of pH (Lin 2008). It was found that the changes in pH within day 10 to day 40 were less significant as compared to the first 10 days of digestion for both samples. This was due to the hardly degradable fractions of the organic wastes (Petric and Mustafi´c 2015). In comparison, both samples showed identical pH at the end of the digestion process. However, from the graph, it is shown that the food waste with lipase achieved the constant and lowest pH on day 30, which was 10 days earlier as compared to the control. This may be due to the action of lipase which sped up the reaction by lowering the activation energy (Salwanee et al. 2013).

3.4 Effect of Lipase Addition on Electrical Conductivity Figure 3.4 displays the electrical conductivity profile for the food wastes with and without lipase. Electrical conductivity (EC) indicates the total salt content in an anaerobic digestate which shows whether the salt content may affect the quality of digestate to be used as a fertiliser. EC measures the total soluble salts in the food waste digestate. The higher the EC, the higher the nutrient content of the digestate. However, EC exceeding 4 dS/m (4 mS/cm) will cause a negative impact on plant growth (Lin 2008). It has been suggested that the suitable electrical conductivity for safe plant growth is 2.5 mS/cm (Himanen and Hänninen 2011). Digestate with low EC can be used directly as fertiliser, whereas digestate with high value of EC must be mixed with soil or other materials with low ECs before it can be used for growing crops (Ishak et al. 2014). As shown by the plot in Fig. 3.4, the initial EC for both samples were 6.26 mS/cm. After 10 days, The EC rose to a maximum value of 8.16 mS/cm and 8.26 mS/cm for food waste without lipase and food waste with lipase, respectively. The increasing trend of EC at the earlier stage was caused by the presence of large quantities of mineral salts such as phosphate and ammonium in the food waste, which were released during the decomposition of organic substance (Lin 2008; Chan et al. 2016). The basic ions released after degradation increased the electrical conductivity (Fang and Wong 1999).

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9.0

Electrical Conductivity, mS/cm

Food Waste 8.0 Food Waste and Lipase

7.0 6.0 5.0 4.0 3.0 0

10

20

30

40

50

Time, days Fig. 3.4 Electrical conductivity profiles from anaerobic digestion of food waste with and without lipase

From Fig. 3.4, it can be observed that after 10 days of anaerobic digestion, the value of EC gradually decreased to 3.08 and 3.05 mS/cm for food waste without lipase and food waste with lipase, respectively. The reduced value of EC was caused by the evaporation of ammonium ion (in the form of ammonia) and reduction of other basic ions as reported by Wong et al. (1995). It was also a direct consequence of the increased concentration of nutrients such as nitrate and nitrite (Bazrafshan et al. 2016). The precipitation and loss of mineral salts also tend to reduce the EC value of organic waste digestate (Ishak et al. 2014; Rawoteea et al. 2017). Finally, it is shown that the increase in electrical conductivity of food waste with lipase was slightly higher than food wastes without lipase due to the higher degradation of the organic waste assisted by lipase, obviously for the first 10 days of digestion, in line with the findings of Chan et al. (2016). The lipase enhanced the hydrolysis of fats, oil and grease in the food waste mixture. The final electrical conductivity of food waste with lipase was lower than the electrical conductivity of the control sample. This finding indicates that anaerobic digestion of food waste with lipase has increased the nutrient content of the digestate.

3.5 Effect of Lipase Addition on Moisture Content Figure 3.5 presents the moisture content profile for the anaerobic digestion of food wastes with and without lipase. Based on the moisture content profile in Fig. 3.5, there were rapid increases in moisture content from day 0 to day 20, decreases from day 20 to day 30, then further increases from day 30 to day 40 for both samples.

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Food Waste

85.0 Food Waste and Lipase

Moisture Content, %

84.0 83.0 82.0 81.0 80.0 79.0 78.0 77.0 76.0 0

10

20

30

40

50

Time, days

Fig. 3.5 Moisture content profiles from anaerobic digestion of food waste with and without lipase

The average moisture contents of food waste and food waste with lipase were found to be unsteady throughout the anaerobic digestion process. Similar trends were observed by Rawoteea et al. (2017) and Narkhede et al. (2010). The fluctuation of moisture content throughout the process was due to the changing of microbial population (Narkhede et al. 2010). The decreasing trend of moisture content for both conditions could be due to the increase in temperature as anaerobic digestion is an exothermic process (Manu et al. 2017). Meanwhile, the increase of moisture content was caused by the condensation of evaporated water on the lid and wall of the reactor. As anaerobic digestion was carried out in a closed system, the condensed water fell back in the mixture which caused an increase in the moisture level of the system (Rawoteea et al. 2017). Moisture content is important as a medium of nutrient transport for the utilisation of microorganisms (Ishak et al. 2014). This is also supported by other researchers who stated that enough amount of water is important for microorganisms to move and transport nutrients (Kulikowska 2016; Manu et al. 2017). The increase in moisture during the digestion process facilitates the growth of microorganisms which eventually enhances the anaerobic digestion of food waste. However, it is difficult to maintain the same availability of water throughout the digestion cycle. In the present work, it was found that the final moisture content achieved by food waste with lipase was higher as compared to the control sample. High moisture content will also affect the process performance by dissolving biodegradable organic wastes. Researchers suggested that anaerobic digestion of wastes with moisture content of 60–80% will yield the highest methane (Bouallagui et al. 2003). On the other hand, there are also researchers who suggested that food waste with moisture content of 95–97% is suitable for anaerobic digestion (Tanimu et al. 2014). Thus, based on the findings, it can be said that the food waste in this work has a suitable moisture

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content for anaerobic digestion which is in the range of 77–86%, which fall in the ideal range of 60–90%.

4 Conclusion The anaerobic digestion of food waste has been conducted. The effects of lipase addition on the Total Organic Carbon (TOC), pH, conductivity and moisture content have been investigated. The addition of lipase has improved the phycochemical properties of the food waste digestate in terms of moisture content and TOC. The addition of lipase shows significant effect of the pH and conductivity for the first 10 days of digestion. However, it has no effect on the final pH and conductivity of the digestate at the end of the digestion process. Based on the findings, it was also found that the lipase used in the present work did not improve the production of biogas. Overall, it can be concluded that the addition of lipase has successfully enhanced the degradation rate but inhibited the biogas production. Therefore, further works such as screening on the type of lipase and optimisation on lipase amount are needed to achieve the desired results.

References Agamuthu, P., & Fauziah, S. H. (2011). Challenges and issues in moving towards sustainable landfilling in a transitory country - Malaysia. Waste Management & Research, 29, 13–19. Ajay, K. J., et al. (2011). Research advances in dry anaerobic digestion process of solid organic wastes. African Journal of Biotechnology, 10(65), 14242–14253. Banks, C. J., et al. (2012). Trace element requirements for stable food waste digestion at elevated ammonia concentrations. Bioresource Technology, 104, 127–135. Bazrafshan, E. et al. (2016) Maturity and stability evaluation of composted municipal solid wastes. 5(1), 1–9. Bouallagui, H., et al. (2003). Mesophilic biogas production from fruit and vegetable waste in a tubular digester. Bioresource Technology, 86(1), 85–89. Capson-Tojo, G. et al. (2016) Food waste valorization via anaerobic processes: A review. Reviews in Environmental Science and Biotechnology, 15(3), 499–547. Carucci, G., Carrasco, F., Trifoni, K., & Majone, M. (2005). Anaerobic digestion of food industry wastes: Effect of codigestion on methane yield. Journal of Environmental Engineering, 131(7), 1037–1045. Chan, M. T., Selvam, A., & Wong, J. W. C. (2016) Reducing nitrogen loss and salinity during “struvite” food waste composting by zeolite amendment. Bioresource Technology, 200, 838–844. (Elsevier Ltd). Dai, X., et al. (2013). High-solids anaerobic co-digestion of sewage sludge and food waste in comparison with mono digestions: Stability and performance. Waste Management, 33(2), 308–316. Domingues, R. F., et al. (2015). Effect of enzymatic pretreatment on the anaerobic digestion of milk fat for biogas production. Food Research International, 73, 26–30. Elsevier Ltd. Dors, G., & Mendes, A. A. (2013). Simultaneous enzymatic hydrolysis and anaerobic biodegradation of lipid-rich wastewater from poultry industry, 343–349.

130

M. Rajin et al.

Fang, M., & Wong, J. W. C. (1999). Effects of lime amendment on availability of heavy metals and maturation in sewage sludge composting. Environmental Pollution, 106, 83–89. Gao, S., et al. (2015). Tolerance response to in situ ammonia stress in a pilot-scale anaerobic digestion reactor for alleviating ammonia inhibition. Bioresource Technology, 198, 372–379. Higgins, G. M., & Swartzbaugh, J. T. (1986) Enzyme addition to the anaerobic digestion of municipal wastewater primary sludge. USEPA Water Engineering Research Laboratory, Office of research and Developement. Himanen, M., & Hänninen, K. (2011). Composting of bio-waste, aerobic and anaerobic sludges—Effect of feedstock on the process and quality of compost. Bioresource Technology. Elsevier Ltd, 102(3), 2842–2852. Ishak, N. F., Ahmad, A. L., & Ismail, S. (2014). Feasibility of anaerobic co-composting empty fruit bunch with activated sludge from palm oil mill wastes for soil conditioner. Journal of Physical Science, 25(1), 77–92. Kanmani, P., Kumaresan, K., & Aravind, J. (2016). Pre-treatment of coconut mill effluent using celite-immobilized hydrolytic enzyme preparation from Staphylococcus pasteuri. Biotechnology Progress, 31(5), 249–1258. Kelleher, B. P., et al. (2002). Advances in poultry litter disposal technology—A review. Bioresource Technology, 83(1), 27–36. Kulcu, R., & Yaldiz, O. (2004). Determination of aeration rate and kinetics of composting some agricultural wastes. Bioresource Technology, 93(1), 49–57. Kulikowska, D. (2016). Kinetics of organic matter removal and humification progress during sewage sludge composting. Waste Management, 49, 196–203. Elsevier Ltd. Kunwar, P., et al. (2017). Food waste to energy: An overview on sustainable approach for food waste management and nutrient recycling. Biomed Research International, 1–19. Li, L., et al. (2015). Bioresource technology dynamics of microbial community in a mesophilic anaerobic digester treating food waste: Relationship between community structure and process stability. Bioresource Technology, 189, 113–120. Li, W., et al. (2016). Two-stage anaerobic digestion of food waste and horticultural waste in highsolid system. Applied Energy, 209, 400–408. Lin, C. (2008). A negative-pressure aeration system for composting food wastes. Bioresource Technology, 99(16), 7651–7656. Manu, M. K., Kumar, R., & Garg, A. (2017). Performance assessment of improved composting system for food waste with varying aeration and use of microbial inoculum. Bioresource Technology, 234, 167–177. Meng, Y., et al. (2017). Enhancing anaerobic digestion performance of crude lipid in food waste by enzymatic pretreatment. Bioresource Technology, 224, 48–55. Moon, H. C., & Song, I. S. (2011). Enzymatic hydrolysis of foodwaste and methane production using UASB bioreactor. International Journal of Green Energy, 8(3), 361–371. Narkhede, S., Attarde, S., & Ingle, S. (2010). Combined aerobic composting of municipal solid waste and sewage sludge. Global Journal of Environmental Research, 4(80), 109–112. Petric, I., & Mustafi´c, N. (2015). Dynamic modeling the composting process of the mixture of poultry manure and wheat straw. Journal of Environmental Management, 161, 392–401. Polprasert, C. (2007) Organic waste recycling—Technology and management. Rajin, M. (2018) A current review on the application of enzymes in anaerobic digestion. In N. Horan, A. Z. Yaser & N. Wid (Eds.) Anaerobic digestion processes. Singapore: Springer. Rawoteea, S. A., Mudhoo, A., & Kumar, S. (2017). Co-composting of vegetable wastes and carton: Effect of carton composition and parameter variations. Bioresource Technology, 227, 171–178. Romano, R. T., et al. (2009). The effect of enzyme addition on anaerobic digestion of Jose Tall Wheat Grass. Bioresource Technology, 100(20), 4564–4571. Elsevier Ltd. Salwanee, S., et al. (2013). Effects of enzyme concentration, temperature, pH and time on the degree of hydrolysis of protein extract from viscera of tuna (Euthynnus affinis) by using alcalase. Sains Malaysiana, 42(3), 279–287.

The Effect of Enzyme Addition on the Anaerobic Digestion …

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Tanimu, M. I., et al. (2014). Effect of carbon to nitrogen ratio of food waste on biogas methane production in a batch mesophilic anaerobic digester. International Journal of Innovation, Management and Technology, 5(2), 116–119. Wong, J. W. C., Li, S. W. Y., & Wong, M. H. (1995). Coal fly ash as a composting material for sewage sludge: Effects on microbial activities. Environmental Technology, 16(6), 527–537. Yang, F., Li, G. X., Yang, Q. Y., & Luo, W. H. (2013). Effect of bulking agents on maturity and gaseous emissions during kitchen waste composting. Chemosphere, 93(7), 1393–1399. Yaser, A. Z., Rahman, R. A., & Kali, M. S. (2007). Co-composting of palm oil mill sludge-sawdust. Pakistan Journal of Biological Sciences, 10(24), 4473–4478. Yaser, A. Z. (2014). Current advances in anaerobic digestion of highly concentrated dye effluent. In J. Fu (Ed.), Dyeing: Processes, techniques and applications (pp. 217–227). New York: Nova Publisher. Zhang, C., Su, H., & Tan, T. (2013). Batch and semi-continuous anaerobic digestion of food waste in a dual solid-liquid system. Bioresource Technology, 145, 10–16. Zhang, C., et al. (2014). Reviewing the anaerobic digestion of food waste for biogas production. Renewable and Sustainable Energy Reviews, 38, 383–392. Elsevier. Zhang, L., et al. (2017). The impact of silver nanoparticles on the co-composting of sewage sludge and agricultural waste: Evolutions of organic matter and nitrogen. Bioresource Technology, 230, 132–139. Elsevier Ltd.

Anaerobic Digestion of Organic Waste in UMS Campus for Resource Recovery and Waste Reduction Newati Wid and Lucita Felicity Ayut

Abstract Phosphorus, a limited non-renewable mineral source can be recovered from food waste in a form of struvite, a slow-release fertiliser. This study was conducted to determine the physical and chemical characteristics of food wastes collected from Tun Mustapha Residences café of Universiti Malaysia Sabah (UMS), to recover phosphorus and reduce the amount of food waste produced. Anaerobic digestion was used to degrade the organic solid waste and solubilise nutrients, which was performed at controlled conditions (pH 6.8–7.2; 37 °C) for 15 days. The results showed that the total solids and volatile solids for the raw sample were high, 42.9% and 94.3%, respectively; due to high solid and organic content. The concentration of magnesium (Mg2+ ), ammonium (NH4 + ) and phosphate (PO4 3− ) after digestion were 114.00 mg/L, 73.87 mg/L and 554.04 mg/L, respectively. The phosphorus can be potentially recovered in the form of struvite with 136 g struvite/g food waste. After anaerobic digestion, total solids and volatile solids were degraded with 40.11% and 76.51% reduction, respectively. Throughout this study, it can be suggested that food waste is naturally high in nutrient content that can be a source for phosphorus recovery in which the waste volume can be reduced after performing anaerobic digestion. Keywords Kitchen food wastes · Phosphorus recovery · Struvite · Anaerobic digestion · UMS

1 Introduction Kitchen waste is one of the municipal wastes comprising degradable and nondegradable materials produced in a kitchen. Non-degradable kitchen wastes refer N. Wid (B) · L. F. Ayut Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia e-mail: [email protected] N. Wid Water Research Unit, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia © Springer Nature Singapore Pte Ltd. 2020 A. Z. Yaser (ed.), Green Engineering for Campus Sustainability, https://doi.org/10.1007/978-981-13-7260-5_10

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to materials used mainly for food packaging and wrappings such as plastic, glass and many other synthetic materials. Meanwhile, degradable kitchen wastes refer to wastes that can degrade such as food wastes (Guttentag 2014), including rice leftover, vegetables and fruits peels. One of the main disposal technique of food waste is by landfilling, thus, high generation of food waste may lead to overflowing of landfill sites. Consequently, contributes to leachate release, air pollution by food decay and odour problems (Zhang et al. 2005). Food waste has high organic content; thus, they are potentially high in phosphorus content, an essential nutrient for living organisms. Phosphorus (P) regards as the most crucial ingredient in food production where it has been used as fertiliser ingredients in agricultural industry. To date, the depletion issue of P is one of the main concern as P is an element which cannot be synthesised or manufactured elsewhere. The prominent source of P is from phosphate rock, which was predicted to be depleted within 100 years, due to the world’s high demand especially in fertiliser industry (Song et al. 2014; Cordell et al. 2009, 2011; Ashley et al. 2011). Unlike oil, P is a nonrenewable source, naturally limited and has no substitute when it reaches its scarcity. Nevertheless, it can be recovered from organic wastes by using proper methods such as anaerobic digestion (Wid et al. 2017; Wid and Horan 2016). Anaerobic digestion is a decomposition of organic material in the absence of oxygen, where it is becoming an emerging technique for resource recovery (Wid and Horan 2016). Ironically, not many people are aware that the leftover on their plates is very rich in nutrient, in which unconsciously the nutrients are lost when disposed on landfill, thus leads to high waste generation and many environmental issues. Universiti Malaysia Sabah (UMS), located in Kota Kinabalu, Sabah, Malaysia, has established the EcoCampus Management Centre in 2013 in which one of the elements the university committed to incorporate is environmental consideration in its planning and activities. Therefore, the present study used food waste sample collected from Tun Mustapha Residences, to consider environmental issues such as waste production and odour problem from food waste. Tun Mustapha Residences is one of the student residences in UMS with a high number of boarders with 1746 students (UMS Housing and Hospitality Section 2018). It is estimated about 10% of students turned up for lunch which contributed to the production of 14 g food waste every day by each student (14 g food waste/person/day). In order to secure the source of P and instead of regarding the excess P in soils as a pollutant, it is more beneficial to remove and recover them as a back up for phosphate rock which takes millions of years to be formed. Thus, the aim of this study is to identify the physical and chemical characteristics of kitchen food waste from Tun Mustapha Residences; and also to determine waste reduction and the potential of phosphorus recovery in the form of struvite through anaerobic digestion.

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2 Materials and Methods 2.1 Sample Collection and Preparation The sample used in this study was food waste collected from the café of Tun Mustapha residence, UMS. The type of sample used was degradable food waste which was collected after lunchtime when needed. The sample included vegetable and fruit peels, chicken and fish bones, egg shells, onion and garlic skins, tea leaves and coffee dregs, waste cooking oil, and leftover rice. The collected samples were cut into small pieces and stored in a fridge at −20 °C to maintain the freshness. Primary sludge (PS) was collected from a water treatment plant and used as inoculum to boost up anaerobic digestion. The PS was stored in a polystyrene bottle and undergone degasification in a water bath at 37 °C for 7 days. The water bath level was set to be a little higher from the PS level in the bottle. Upon completing the degasification process, the PS was then incubated in the water bath at the same temperature (as degasification) for storage.

2.2 Determination of Food Waste Composition The composition percentage (%) of each food waste type was determined using Eq. 1. Composition (%) =

(F W, g) × 100% (F W t, g)

(1)

where, FW = weight of food waste type (g) FWt = total weight of food waste (g)

2.3 Preparation of Food Waste Raw Liquid (FWRL) The sample was cut into smaller pieces, weighed and placed in a polystyrene bottle; and mixed with distilled water at ratio 1:10 (sample, g to distilled water, mL) in 200 mL of working volume. The bottle was shaken in an orbital shaker for 24 h at room temperature. The mixture was then filtered using vacuum filter, followed by 0.45 μm Whatman syringe filter. The filtered liquid was stored in a fridge prior to use.

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2.4 Preparation of Food Waste Digested Liquor (FWDL) for Anaerobic Digestion The FWDL was prepared by performing 15 days anaerobic digestion (AD) using 200 mL working volume as described by Owen et al. (1979), Hansen et al. (2003) and Angelidaki et al. (2009). PS was added into the anaerobic reactor (250 mL Duran bottle with stopcock) at ratio 1.5:1.0 (sample to inoculum). The percentage of total solids (TS) and volatile solids (VS) were first obtained in order to determine the amount of sample added into the reactor. The pH value of the mixture on Day 1 was controlled to be in the range of 6.8–7.2 using 1.0 M hydrochloric acid (HCl) and 1.0 M sodium hydroxide (NaOH). The reactor was placed in a water bath for 15 days at 37° and was manually shaken once per day. The biogas produced was released daily to avoid reactor explosion and the pH value and temperature were monitored every three days. On Day 15 (final day) about 5 mL of digested liquor was taken and filtered for physicochemical analysis.

2.5 Physical Characterisation of Food Waste The physical characterisation of the sample was performed based on the method outlined by APHA (2005). The raw sample of food waste was used to determine the physical characteristics. The studied parameters including pH, TS, and VS. The pH was determined using a pH meter which calibrated using standard buffer solutions of pH 4 and pH 7. The TS and VS were determined by weighing out an empty crucible, g (A), followed by the loading of wet sample into the crucible. The crucible with a wet sample, g (B), was placed in an oven for 24 h at 105 °C. A further step was transferring into desiccator to cool down. The crucible with dried sample, g (C), was weighed and then placed into a furnace for 4 h at 550 °C. Upon complete, it was again transferred into the desiccator for the same purpose and the crucible with ash sample, g (D), was then weighed. The percentage of TS and VS were calculated by using Eqs. 2 and 3, respectively (APHA 2005). (C − A) × 100% (B − A) (C − D) V S (%) = × 100% (C − A) T S (%) =

(2) (3)

2.6 Chemical Characterisation of Food Waste The chemical characteristics were determined in terms of the concentrations of magnesium (Mg2+ ), ammonium (NH4 + ) and phosphate (PO4 3− ) ions. The concentration

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of Mg2+ was obtained using Atomic Absorption Spectrometer (AAS), at 285.2 nm of wavelength (λ). Five (5) standard solutions with different concentrations (0.5, 1.0, 1.5, 2.0 and 2.5 ppm) were prepared from 1000 ppm of Mg standard solution and used to generate a calibration curve. The concentration of NH4 + was determined using Kjeldahl method (Buchi), where the concentration of PO4 3− was determined using UV-Vis Spectrophotometer (Cary 60), λ = 800 nm, using five (5) standard solutions with different concentrations (1, 2, 3, 4 and 5 ppm) which were prepared from 100 ppm of PO4 3− stock solution. The chemical characteristics were carried out using FWRL and FWDL according to the method described by APHA (2005).

3 Results and Discussion 3.1 Composition of Food Waste Samples Figure 1 shows the percentage (%) of different components of food waste used in this study, where vegetables and fruit peels comprised the highest percentage (45.73%) followed by chicken and fish bones (19.68%), while unused part of meats contributes the lowest percentage (0.62%). Other components were between 3.28 and 12.59%. The sampling points and sampling period are the important factors, which may affect the percentages. The unused vegetable parts such as stem and spoiled leaves that are produced during food preparation stage may be the reason for its highest percentage. In addition, the café may also produce a huge amount of vegetable leftovers as most students refused to eat vegetables (Griffin et al. 2009). The unused part of meats such as chicken skins and fats has contributed the lowest percentage because most people consumed those parts of meat (Y-Sing 2007).

3.2 Physical Characterisation of Food Waste The pH values of FWRL and FWDL fell in the range of 6.30–7.10, contrary to the previous study done by Griffin et al. (2009) which between pH 3.0–4.0. The sample in this study has undergone neutralisation due to the presence of calcium carbonate, CaCO3 , contributed by eggshell. CaCO3 is an alkali, which when reacting with acidic medium (food waste) will change properties to neutral (Hamer 2003). The TS and VS of FWRL and FWDL were 42.9% and 94.29%, respectively, indicate that the food waste was very high in organic content. These high values also suggest that food waste is not suitable to be disposed on landfill, due to the high potential of greenhouse gases (GHGs) release and odour problem. The determination of TS and VS was done in order to determine the organic loading rate of the substrate to be used in the AD process. According to Zhang et al. (2005), AD process can be proceeded if the TS and VS values were approximately

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3.96

3.28

0.62

6.18

Vegetable & fruit peels Chicken & fish bones

7.96

45.73

Others Egg shells Onion & garlic skins

12.59

Waste cooking oil Tea leaves & coffee dregs Unused part of meats 19.68 Fig. 1 Composition percentage of food waste samples Table 1 Concentration of Mg2+ , NH4 + and PO4 3− in FWRL and FWDL

Nutrient Mg2+ (mg/L) +

FWRL

FWDL

45.73

114.00

NH4 (mg/L)

192.06

73.87

PO4 3− (mg/L)

509.18

554.04

20% and 90%, respectively. Hence, based on the results obtained, the TS and VS values were found to be in the suitable ranges, albeit rather high for TS due to high solid component was found in the food waste, such as chicken and fish bones.

3.3 Chemical Characterisation of Food Waste Table 1 shows the average concentration of Mg2+ , NH4 + and PO4 3− in FWRL and FWDL samples obtained by AAS, Kjedahl and UV-vis spectrometer, respectively. It was found that the concentration of Mg2+ increased from 45.73 mg/L in FWRL to 114.00 mg/L in FWDL. Both samples contained dissolved solids (inorganic) and suspended solids (organic) which made up the total solids in the sample. During the AD, as the organic solid degraded, the inorganic solids solubilised. Thus, an inorganic nutrient such as Mg2+ will be increased due to the solubilisation (Telliard 2001; Othman et al. 2010). While the concentration of NH4 + decreased from 192.06 mg/L in FWRL to 73.87 mg/L in FWDL. This contradicts to the previous study by Tyagi and Lo (2013) where the NH4 + concentration increased after undergone AD. Nitrogen entered the AD reactor in organic form which was easily converted to NH4 + during the AD via nitrogen mineralisation. However, due to incomplete mineralisation which occurred when mildly acidic NH4 + ions react with Brønsted bases; some of the

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organic nitrogen may be converted to ammonia, NH3 gas as shown in Eqs. 4 and 5 (Metcalf and Eddy 1991). H + + N H3 → N H4+

(4)

N H4+ + B − → H B + N H3

(5)

Thus, it can be assumed that a certain amount of NH3 gas was released as biogas during the degasification of 15 days AD period. This occurrence also explained the unpleasant odour released from the reactor during the degasification. The concentration of PO4 3− slightly increased from 509.18 mg/L in FWRL to 554.04 mg/L in FWDL. According to the past research by Frear and Dvorak (2011), the amount of PO4 3− should increase ~60% after the AD. Instead, in this study, it only occurs at ~8.8%. As mentioned earlier, when nutrients such as Mg2+ , NH4 + and PO4 3− exist in equimolar ratio, they can form a directly used fertiliser called struvite. During the 15 days period of the AD, all those ions may already present in an equimolar ratio in the reactor which subsequently leads to struvite precipitation. This is possible because the controlled conditions of the AD (37 °C and pH 6.8–7.2) is the optimum condition for struvite formation. Hence, it can be assumed that some of the PO4 3− were precipitated as struvite in the digested liquor. This explained the cloudy solutions and the brownish-white precipitate that appeared and settled at the bottom of the glass bottle during sample storage after filtration.

3.4 Potential of Phosphorus (P) Recovery from Anaerobic Digestion of Food Waste In this study, P recovery is represented by the concentration of soluble phosphate, PO4 3− in the digested liquor. The percentage of P recovery was low (~8.8%), which was calculated based on the initial PO4 3− concentration before AD. Even though the percentage of recovery was low, the concentrations of PO4 3− in food waste, both before and after AD, were significantly high. This indicates that food waste is a naturally nutrient-rich waste and an excellent source of phosphorus. Table 2 compares P concentrations with previous studies which revealed the current study has the highest P concentration. One of a way to recover P from the digested liquor is through precipitation to form struvite (magnesium ammonium phosphate, MgNH4 PO4 .6H2 O.6H2 O). Table 3 shows the potential of P recovery in a form of struvite which was calculated using a molar ratio of Mg2+ , NH4 + and PO4 3− in the digested liquor. This suggests that 1 g of struvite can be precipitated from 1 L of digested liquor. The recovery can also be expressed based on the weight of food waste added in the anaerobic digester. In this case, 136 mg of struvite can be recovered from every 1 g of food waste used for anaerobic digestion. If we consider the amount of food waste produced by the

140 Table 2 Comparison of P recovery with previous studies

Table 3 Potential of P recovery in a form of struvite

N. Wid and L. F. Ayut

Type of substrate

P recovery (mg/L)

References

POME

139

Wid et al. (2017)

POME

180

Madaki and Seng (2013)

Sewage sludge

400

Murto et al. (2004)

Food waste

483

El-Mashad and Zhang (2010)

Food waste

355

Kubaska et al. (2010)

Food waste (fiber)

147

Selaman and Wid (2016)

Food waste

520

Shin et al. (2004)

Food waste

554

This study

Recovery (unit)

Value

Struvite recovery (g/L)

1.00

Struvite recovery from the wet weight of food waste (mg struvite/g food waste)

136

Struvite recovery from food waste in UMS (Tun Mustapha Residences) (mg struvite/g food waste)

340,816

students each day, which was 2,506 g food waste (contributed by the 10% students turned up for lunch), about 340,816 mg struvite can be potentially recovered daily.

3.5 Total Solids and Volatile Solids Destruction The destruction of TS and VS occurs as the organic substances in food waste were degraded by microorganisms and turned to digested liquor and biogas. The digested liquor is rich in nutrients by which when exists in equimolar ratio of Mg2+ , NH4 + and PO4 3− can form struvite, a substance that can be used as direct slow-release fertiliser. The destruction of TS and VS were very high with 40.11% and 76.51%, respectively, compared to the previous study only 17.81% and 41.34%, respectively (Deressa et al. 2015). High destruction indicates that the type of food waste used in this study was highly degradable due to high in organic content, thus suitable for AD. There are possibilities that may cause the difference in TS and VS destruction with the previous study, which is the type of food waste and inoculum used for AD. The previous study used rice, fruits and meat leftovers only, while this study used a mixture of all composition of food waste as shown in Fig. 1. This suggests using multiple types of food waste may enhance the solids and volatile solids destruction during AD. Type of inoculum used as the source of bacteria during AD also affects

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degradation. In this study, sewage sludge was used as inoculum, while Deressa et al. (2015) used cow manure. Cow manure contains high lignocellulosic which is due to the food consumed by the cow. Since cow is fed with grass, part of the grass that indigestible will be excreted out in their manure. The presence of lignocellulosic in manure inhibits the completion process of AD (Nielsen and Angelidaki 2008) making the process in the non-optimal state. Hence, this might cause the low TS and VS destruction in the previous study. Iacovidou et al. (2012) reported that digestion of food waste with sewage sludge as inoculum causes high reduction of organic content in food waste. Therefore, the type of inoculum used in AD is very important in order to have a high degradation of solid wastes (Forster-Carneiro et al. 2008).

4 Conclusions In this study, the physical and chemical characteristics of kitchen food wastes samples were determined using FWRL (raw sample liquid) and FWDL (digested sample liquor). Anaerobic digestion was chosen as a method of study as it can release a significant amount of nutrients due to the breakdown of organic substances by anaerobic bacteria. Determination of physical characteristics including pH, TS and VS are very important as they affect greatly on the digestion performance and to design the experimental work of anaerobic digestion. In this study the pH of the food waste ranged between pH 6.30 and 7.10, suggests anaerobic digestion of food waste does not highly dependent on chemical addition to control the pH, because the optimum pH for anaerobic digestion was reported to be between pH 6.8and 7.2. The presence of CaCO3 , represented by eggshell may contribute to the pH values. Chemical characteristics such as the concentration of Mg2+ , NH4 + and PO4 3− , on the other hand, show that kitchen food waste contains high nutrients. Mg2+ and PO4 3− increased after digestion, but not for NH4 + . At least there are two possibilities which may cause the decreased in NH4 + and low PO4 3− increased in FWDL, i.e., NH4 + may be converted to ammonia (NH3 ) or struvite may be formed during the AD process, when the molar ratio present in equimolar. Nevertheless, the P content was very high both in FWRL and FWDL and if precipitated, 136 g struvite can be formed from 1 g of food waste. This suggests that food waste is naturally high in nutrient content. If we consider the amount of food waste generated in Tun Mustapha Residences each day, about 0.34 kg struvite (340,816 mg struvite/g food waste) can be potentially recovered. In this study, P recovery was also addressed as struvite recovery because phosphate can be precipitated as struvite with the presence of magnesium and ammonium ions. Anaerobic digestion was not only to stabilised sludge and recover resources, but also to reduce waste volume. In this study the total solids and volatile solids were successfully reduced with a high percentage of 40.11% and 76.51%, respectively, indicates that the type of food waste used in this study was highly degradable and high in organic content. This destruction can help in diverting waste from landfill and saving space, reduce unpleasant odour as well as greenhouse gases release. This study is important as this is the first study was

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conducted to investigate the potential of phosphorus recovery from food waste that generated in the student residences in UMS which should be continued. By turning food waste into struvite, it can be an alternative to the existing fertiliser in the market as it is reportedly an effective slow-release fertiliser or soil conditioner, at the same time reduce waste generation in the UMS campus. Acknowledgements The authors would like to acknowledge the Ministry of Higher Education (FRG0368-SG-1/2014) and Universiti Malaysia Sabah (GUG0119-1/2017) for the financial support.

References Angelidaki, I., Alves, M., Bolzonella, D., Borzacconi, L., Campos, J. L., Guwy, A. J., et al. (2009). Defining the biomethane potential (BMP) of solid organic wastes and energy crops: A proposed protocol for batch assays. Water Science & Technology—WST, 59(5), 927–934. APHA. (2005). Standard methods for the examination of water and wastewater, 21st ed. Washington D.C: American Public Health Association & Water Pollution Control Federation. Ashley, K., Cordell, D., & Mavinic, D. (2011). A brief history of phosphorus: From the philosopher’s stone to nutrient recovery and reuse. Chemosphere, 84(2011), 737–746. Cordell, D., Drangert, J.-O., & White, S. (2009). The story of phosphorus: Global food security and food for thought. Global Environmental Change, 19, 292–305. Cordell, D., Rosemarin, A., Schroder, J. J., & Smit, A. L. (2011). Towards global phosphorus security: A systems framework for phosphorus recovery and reuse options. Chemosphere, 84(2011), 747–758. Deressa, L., Libsu, S., Chavan, R. B., Manaye, D., & Dabassa, A. (2015). Production of biogas from fruit and vegetable wastes mixed with different wastes. Environment and Ecology Research, 3(3), 65–71. El-Mashad, H. M., & Zhang, R. (2010). Biogas production from co-digestion of dairy manure and food waste. Bioresource Technology, 101(11), 4021–4028. Forster-Carneiro, T., Perez, M., & Romero, L. I. (2008). Influence of total solid and inoculum contents on performance of anaerobic reactors treating food waste. Bioresource Technology, 99(15), 6994–7002. Frear, C., & Dvorak, S. (2011). Anaerobic digestion and nutrient recovery. In AGSTAR National Conference. New York. Griffin, M., Sobal, J., & Lyson, T. A. (2009). An analysis of a community food waste stream. Agriculture and Human Values, 2009(26), 67–81. Guttentag, R. M. (2014). Recycling of organic wastes. Rockville, United States of America. Hamer, G. (2003). Solid waste treatment and disposal: Effects on public health and environmental safety. Biotechnology Advances, 22(1–2), 71–79. Hansen, T. L., Svard, A., Angelidaki, I., Schmidt, J. E., Jansen, J., & Christensen, T. H. (2003). Chemical characteristics and methane potentials of source-separated and pre-treated organic municipal wastes. Water Science and Technology, 48(4), 205–208. Iacovidou, E., Ohandja, D-G., & Voulvoulis, N. (2012). Food waste co-digestion with sewage sludge-realising its potential in the UK. Journal of Environmental Management, 112, 267–274. Kubaska, M., Sedlacek, S., Bodik, L., & Kissova, B. (2010). Food waste as biodegradable substrates for biogas production. In Proceedings of the 37th International Conference of Slovak Society of Chemical Engineering, May 24–28 2010. Tantranske Matliare, Slovakia. Le Corre, K. S., Valsami-Jones, E., Hobbs, P., & Parsons, S. A. (2009). Phosphorus recovery from wastewater by struvite crystallization: A review. Critical Reviews in Environmental Science and Technology, 39, 433–477.

Anaerobic Digestion of Organic Waste in UMS Campus …

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Madaki, Y. S., & Seng, L. (2013). Palm oil mill effluent (POME) from Malaysia palm oil mills: Waste or resource. International Journal of Science, Environment and Technology, 2(6), 1138–1155. Metcalf., & Eddy. (1991). Wastewater engineering: Treatment, disposal and reuse. USA: McGrawHill, Inc. Murto, M., Bjornsson, L., & Matiasson, B. (2004). Impact of food industrial waste on anaerobic co-digestion of sewage sludge and pig manure. Journal of Environmental Management, 70(7): 101–107. Nielsen, H. B., & Angelidaki, I. (2008). Strategies for optimizing recovery of the biogas process following ammonia inhibition. Bioresource Technology, 99, 7995–8001. Othman, M. Z., Uludag-Demirer, S., & Demirer, G. N. (2010). Enhanced nutrients removal in conventional anaerobic digestion processes. International Journal of Civil and Environmental Engineering, 2(4), 203–209. Owen, W. F., Stuckey, D. C., Healey, J. B., Jr., Young, L. Y., & Mccarty, P. L. (1979). Bioassay for monitoring biochemical methane potential and anaerobic toxicity. Water Research, 13(6), 485–492. Pollution. (2015). Retrieved from Science Clarified. http://www.scienceclarified.com/Ph-Py/ Pollution.html. Selaman, R., & Wid, N. (2016). Anaerobic co-Digestion of food waste and palm oil mill effluent for phosphorus recovery: Effect of reduction of total solids, volatile solids and cations. Transaction on Science and Technology Journal, 3(1–2), 265–270. Shin, H. S., Youn, J. H., & Kim, S. H. (2004). Hydrogen production from food waste in anaerobic mesophilic and thermophilic conditions. International Journal of Hydrogen Energy, 29, 1355–1363. Sludge Sorts. (2015, June 03). Retrieved from Lenntech BV: http://www.lenntech.com/library/ sludge/sorts/sludgesorts.htm. Song, Y., Dai, Y., Hu, Q., Yu, X., & Qian, F. (2014). Effects of three kinds of organic acids on phosphorus recovery by magnesium ammonium phosphate (MAP) crystallization from synthetic swine wastewater. Chemosphere, 101(2014), 41–48. Telliard, W. A. (2001). Method 1684: Total, fixed and volatile solids in water, solids and biosolids. Washington: U.S. Environmental Protection Agency. Tyagi, V. K., & Lo, S.-L. (2013). Sludge: A waste or renewable source for energy and resources recovery? Renewable and Sustainable Energy Reviews, 25(2013), 708–728. UMS Housing and Hospitality Section. (2018). Student Affairs Department, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia. Wid, N., & Horan, N. (2014). Resource recovery from anaerobically digested liquor of wastewater screenings. Borneo Science, 34, 52–59. Wid, N., & Horan, N. J. (2016). Anaerobic digestion of wastewater screenings for resource recovery and waste reduction. IOP Conference Series: Earth Environmental Science, 36(1), 012017. Wid, N., Selaman, S., & Jopony, M. (2017). Enhancing phosphorus recovery from different wastes by using anaerobic digestion technique. Advanced Science Letters, 23(2), 1437–1439. Y-Sing, L. (2007, December 17). Healthy eating, Malaysian style. Kuala Lumpur, Malaysia: Live Mint E-Paper. Zhang, B., Zhang, L. L., Zhang, S. C., Shi, H. Z., & Cai, W. M. (2005). The influence of pH on hydrolysis and acidogenesis of kitchen wastes in two-phase anaerobic digestion. Environmental Technology, 26(2005), 829–889.

Green Engineering for Waste Management System in University—A Case Study of Universitas Gadjah Mada, Indonesia Arif Kusumawanto and Mega Setyowati

Abstract Green engineering and green architecture are one of the concepts of sustainability by considering the economic feasibility and human well-being, and keeping in mind the risk factors to keep them to a minimum. The concept can be used as a basis for making policies or regulations for the sustainability of a green campus. Assessment and ranking of the sustainability of the green campus can use the UI GreenMetric research method and has 6 criteria. Waste management is one of the criteria that must be met to achieve sustainability of the green campus program and has a weight of 18% of the total assessment. Green engineering has 12 principles that can be used as a basis for the realization of green campus sustainability, especially in the waste management system. Universitas Gadjah Mada has implemented the 12 principles of green engineering ranging from the preparation of the Standard Operational Procedure system for campus waste management to the selection of renewable waste processing technology in accordance with the type of campus waste generation. Based on the GreenMetric valuation method regarding the waste management system, Universitas Gadjah Mada has a weight value of 10.50% of the total 18%. Keywords Green engineering · Sustainability · Waste management system · GreenMetric

1 Introduction Green engineering is the design, commercialization, and use of processes and products that apply feasible technology, consider economic viability and efficiency, minimize pollution, avoid human health and environment damages, promote sustainability (Sadiku et al. 2018). In addition, green engineering also focuses on how sustainability A. Kusumawanto · M. Setyowati (B) Universitas Gadjah Mada, Yogyakarta, Indonesia e-mail: [email protected] A. Kusumawanto e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Z. Yaser (ed.), Green Engineering for Campus Sustainability, https://doi.org/10.1007/978-981-13-7260-5_11

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can be achieved both in terms of science and technology (Anastas and Zimmerman 2007). A green engineer is required to apply a feasible strategy or technology that minimize all risk factors or potential hazards in order to achieve sustainable development without sacrificing economic viability and efficiency. Pollution, human health, the threat of environmental damages, and the use of material and energy are urgent factors that should be analyzed and calculated in the beginning to the end of cycles of product or processes. Global warming is one example of the potential danger of environmental damage. One of the factors causing global warming also comes from buildings. Buildings and cities have contributed to greenhouse gases and global warming issue through some human activities inside the building and in the city, e.g., the use of not eco-friendly air-conditioning room, and mining and burning fossil-fuel activities to run the car and other devices. We all realize that the energy reserves are limited and will run out. Efforts that can be made to reduce global warming can be achieved by applying a green movement. The green movement arises as a result in awareness of the fact that our earth is getting warmer due to various processes of human life, especially in burning fossil fuels to produce carbon dioxide and greenhouse gas effect or well known as GHG. Since architecture, building, and city are contributors in global warming, so both architect and city planner play an important role to deal with this issue through their product in building-design and city-planning. The Green Architecture Movement is no longer a motto or wishful thinking on the cloud, but it is a joint obligation to be realized and strived together. The green architecture contains two focus of attention. The two focuses are creating beauty and welfare through the architectural work, while focusing on how to minimize environmental damage. The greener architecture means the greater the welfare produced and the smaller the environmental damage that occurs. A building can’t be categorized as part of green architecture if the building has considerable damage factors, even though the building has minimized energy use and reduced environmental damage in operational activities. Damage that might occur in a building for example; buildings are not beautiful, less prosperous residents, do not function properly. This condition is based on the theory of sustainability habitat system, where sustainability will decrease if the damage factor is greater or more diverse when compared to the welfare obtained. Take the extreme example of a small house inhabited by many people. Although using very little electricity, and small land, it becomes very humid and hot, not comfortable because the ventilation is not enough to supply air, and it causes unproductive activities inside the house and more dispute among the residents. And vice versa, the very artistic and beautiful building and liked by many people, but taking very large environmental damage due to the erection of the building, many tree logging, taking a large ground surface, blocking the absorption of rainwater and consuming very large energy, can’t be called as green architecture, because the value of the Throughput (T) is very low. What is green architecture? Going back to the rock era to live in caves, without vehicles and computers, gadgets and all the comforts we have enjoyed at the previous

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time is not the answer or solution. Architecture still has to function well, sturdy, and beautiful and support the current lifestyle and keep being eco-friendly. All in all, green architecture should be able to achieve maximum welfare, minimal damage to the environment. The greater the welfare created and at the same time the smaller the environmental damage occurs, the greener the architecture becomes. To optimize the prosperity through architectural works, there is a theory of Architecture of Habitat System for Sustainable Development that can be referred to. This theory was developed by a Kyushu University research team in Japan in 2007 and this theory is about the sustainability of this natural habitat system. In this theory, welfare is explained as all factors impacting safety, relief, health, comfort, and sense. Through comprehensive research, for 5 years Kyushu University has formulated a mathematical formula, which is easily understood by everyone with different multidisciplinary science and background, namely T = W − D (Matsufuji 2004). Based on the mathematical formula, it can be explained that “T” stands for Throughput, “W” stands for Welfare and “D” is (environmental) Damage. The higher the value of Throughput (T), the more sustainable the architecture will be. The resulting welfare is carried out as much as possible and damage that is caused by environmental damage is minimized. In the description of the theory, welfare created by an architectural work can be identified in 4 + 1 factors. The 4 + 1 factors are the form of safety, happiness, health, comfort, and the plus one factor is sense, taste, or awareness. These four factors are achieved by an efficiency strategy along with 1 factor “taste” so the five factors are achieved by a sufficient strategy (Matsufuji 2004). How should the green architecture be designed to be more efficient in terms of building safety and more sufficient in terms of this sense of security? To be able to answer this, we could take an example in designing a building for the earthquake risk. After the earthquake in 2006 in Yogyakarta, the architect will design buildings and structure responding efficiently to the building standard for earthquake area. How to meet the minimum standards without too excessive effort and material causing waste and ineffective strategy is the main consideration to make a decision in design. When creating a building, there are standards and requirements that have been set in an area. However, if the construction of a building exceeds the existing requirements and is too strong, then the building can be said to be inefficient and waste building materials and other resources to over-create the building. A sense of security for residents and building users must be sufficiently created, such as information about mitigation system in the building during the earthquake time, by installing evacuation signs, designing safe gathering places to facilitate rescue activities, and so on. Moreover, the other three important factors are happiness or feeling of pleasure, health, and comfort. The approaches of the three important factors are responding to the efficient principles and creating these feelings adequately. Now, we can understand that maximizing prosperity in the context of green architecture is through an effective strategy and sufficient security for all users and residents of the designed building or area, not from strengthening or adding excessively. In order to achieve sustainable development and to maximize benefits, we must be able to minimize environmental damages.

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Green engineering and green architecture have the same goal of minimizing environmental impacts as well as human health in order to achieve sustainable development. Sustainable development is “Development that meets the needs of the present without compromising the ability of future generations to meet their own needs” (Sonnemann and Margni 2015). Green engineering and green architecture have the same goal of minimizing environmental impacts as well as human health in order to achieve sustainable development. Sustainable development is “Development that meets the needs of the future without compromising the ability of future generations to meet their own needs”.

2 Methods 2.1 The Principle of Green Engineering The green campus is part of green engineering and the 12 principles in green engineering can be applied to support sustainability. The sustainability assessment of campus can utilize the UI GreenMetric World University Rankings. In GreenMetric, there are six categories, namely Structuring and Infrastructure, Energy and Climate Change, Waste, Water, Transportation, Education, and Research. Waste management is one of the categories and indicators that must be met by the university so that the sustainability of the green campus can be assessed. The university activities and the environment in a tropical climate have made a different type of waste. The green landscapes on a whole year in tropical climates tend to produce more waste from the garden and leaves, so composting the waste can be a strategic approach to deal with this climate to give more benefit to environment and human. In addition, lifestyle plays important role in the waste management system. The plastic usage in lives of current people has become uncontrollable and created a waste dump in ocean and land and pollution in the air. Plastic waste is still the most challenging problem for the environment. The university can take important action to design a waste management system regarding the conditions of the university and the climate where the university is located. Every university has a different type of garbage, even though located in the same city and climate. Campus with an open design with no fence and any boundary will have a more diverse type of garbage compared to a campus with a closed design. This is possible because the campus with an open design can be a mediator of household waste disposal in the surrounding community. The way to deal with the waste in the university area depends on the policies made by each university. Mostly the strategy was taken by many universities still dispose of the waste in the closed landfills or burn the waste dump. The more universities take action in waste management, the fewer the landfills bear the amount of the dump. Green engineering has 12 principles. The 12 principles are inherent rather than circumstantial; prevention instead of treatment; design for separation; maximize mass,

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energy, space, and time; output-pulled versus input-pushed; conserve complexity; meet need, minimize excess; minimize material diversity; integrate local material and energy; design for commercial “afterlife”; and renewable rather than deleting (Anastas and Zimmerman 2007). Those 12 principles of green engineering can be implemented in the university area to support and optimize the sustainability of green campus programs. The population and human necessities have increased over time. And it produced more waste. Both residential and university areas, which have intense activities also produce a lot of waste on a daily basis. Without a good waste management strategy, it will result in a waste dump and problems at the residential or university area itself or at the final waste disposal. This is certainly not in accordance with the principles of green engineering. Regarding the 12 principles of green engineering, the university should have a strategy in waste management to realize the sustainability of green campus and to minimize the risk factors or potential hazards posed by waste. The 12 principles of green engineering can be applied in the university area as a basis or reference to minimize waste generation and support the sustainability of green campus programs. 1. Inherent rather than circumstantial The university (stakeholders) can act as a waste management system designer by issuing SOPs or Regulations that deal with the problem of waste from source to processing products. Before designing, the university must first study what inputs to output are involved during the process. The main and supporting material for the waste treatment process must be ensured that it does not endanger human health and the environment. The energy needed and produced during the process must also be free from potential hazards. 2. Prevention instead of treatment During the waste management process, the potential for the formation of waste can still occur. In the campus waste management system, the university can design regulations regarding limiting the amount of waste generation from the source. For example, the academic community as a source of waste is encouraged to reduce the use of paper in academic activities, not to use too much plastic in the canteen area, always to consume the food that has been ordered, etc. If the effort to reduce waste has started from the waste source, it is expected that the potential for waste that is formed during the waste management process can be minimized. 3. Design for separation Garbage comes from human or natural waste and has different types or properties of different materials. In the waste management system, the type and nature of the waste must be known to facilitate the production process, streamline costs during the process, and can minimize the amount of energy and supporting materials needed. Waste sorting must be done from the source to facilitate the process and selection of the technology used. University stakeholders who act as green engineers can set regulations regarding the standardization of sorting waste types. Sorting types of

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waste can be divided according to the type of waste produced at each university. Simply put, this type of waste can be divided into organic waste and inorganic waste. 4. Maximize mass, energy, space, and time efficiency The waste management system must be designed to maximize material use, energy, equipment, and time efficiency. The amount of waste generation must also be known for the sustainability of the production process. The amount of waste generation based on its type can be the basis for maximizing the type of technology and production capacity. Sorting waste types from the source will make it easier to choose the type of technology used and save processing time. Energy efficiency during the process can also be maximized with the selection of appropriate technology. 5. Output-pulled versus input-pushed In waste management, system inputs will have an influence on the sustainability of the system or process, so that the type and nature must be considered properly. Stakeholders as green engineers need to consider the quality and quantity of material and energy involved during the process. In addition to material/raw material inputs, the number of resources involved during the process must also be minimized so that operational costs are low. The number of operators can be minimized by being supported by waste processing technology that is suitable for campus conditions. The campus area which has a large amount of vegetation will be more effective when processing organic waste produced, into products that are useful for plants such as compost. 6. Conserve complexity In designing a system in waste management, all aspects from the input to the output of the complexity of the production process should be considered. The raw material in waste management system needs to be explored and identified further whether the material is more suitable to reduce, recycle, reuse, reprocessing, or more efficient to dispose of directly by considering environmental factors and economic feasibility. The material with a high complexity component needs considering and calculating the time, cost, and process before taking the recycle process. The high complexity components of material need more time in the recycling process because the constituent components must go through several difficult treatments. Considering economic feasibility, the recycle process with high complexity components has a low level of feasibility regarding the objectives of green engineering. Reuse is a strategic solution for material with high complexity components, and recycle is more suitable for material with low complexity components. 7. Durability rather than immobility The selected technology in waste management system must be durable following at least the expected time and flexible through time and technological development. The technology used in a process must reach the specified time and avoid the risk of harm to the environment. The effective and efficient technology with regular maintenance and repair is more likely to occur compared to long-lasting technology.

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8. Meet the need, minimize excess On the one hand, a waste management system or process must be designed and adjusted to the magnitude of the needs and on the other hand, the system and process should take into account the factors impacting the input to output. Excessive design in a waste management system or production process will result in high costs in capital and operational costs. The high cost of both costs leads to a lack of economic feasibility in the waste management system or production process. And the highcost result in excessive design should be avoided in accordance with the objectives of green engineering. In addition to minimizing costs and waste during the process, the green engineer must design specifically and pay attention to the selected system or process to remain in line with the users’ demand and final targets. 9. Minimize material diversity The diversity of the material components used in the waste management system or production process give a significant impact on the waste management system and treatment. Components or materials used in inputs must be as low as possible in diversity. The more diverse components in a system or process will ask the more treatment. The diversity of components will allow more material to be wasted than further processed. Components with low diversity in the material will be easier to be processed by reusing or recycled into new products.. 10. Integrate local material and energy flow The design of a waste management system or production process in green engineering tries to integrate available local material with the amount of energy needed. Integration between material and energy in the production system or process can be carried out starting from input to output, as well as other factors, such as support and transport facilities to the area. The availability and integration of local raw material and energy on the site could give benefit to the system or process. 11. Design for commercial “Afterlife” Considering the use value at the end of material and involved components is also a strategy in the waste management system. Components involved in the system or production process must be considered whether it can be reused or recycled to maintain its value and usefulness. Components with high commercial value or easily reused will reduce waste and maintain environmental health and have economic viability. 12. Renewables rather than depleting The renewable material and energy are better than depleted material and energy. System design or production process must pay attention to the nature of the raw material. The renewable raw material and energy are less damaging to the environment. In addition, waste processing technology must be renewable to overcome the increasing quantity or even the quality of waste disposed of in line with human needs.

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2.2 Waste Management as an Approach in Green Engineering Waste management in the university has different characteristics from waste management in city level and general. This is due to campus activities, which are uniquely compared to other areas in the city. Garbage generation generated by the campus with open areas has different types of waste when compared to campuses with closed campus areas. Garbage generation in the open campus area has more complex types of waste and the type of waste is almost the same as the type of urban waste. This condition occurs because people around the campus area can easily dispose of household waste at certain points within the campus area. In the Green Architecture study, waste management is a principle in Zero Waste concept and activity, in creating a sustainable area. Designing, analyzing, and evaluating a process or a region, a green engineer must be able to minimize the risk factors, potential hazards, direct, and indirect impact on human health and the environment that might occur. All the efforts to mitigate all the risk factors and potential hazards must be holistic, starting from the input information, data, and source to the final output of a planning process or design. Waste is unwanted and unusable materials as a result of human activity or activities in the region. Trough period of time and the growth of population and human needs, it can be accumulated creating a mound of unusable material and generate potential hazards for human health and environment. Waste can be minimized and reduced by a certain approach, effort, and strategy. In accordance with the basic principles of green engineering. Waste as an issue is not only found in the residential area but also in university areas although the type of waste produced in both residential and university areas is slightly different. Mostly the waste management in university area still uses conventional methods, in the sense that the generated waste generation will usually be collected at the garbage collection points and then will be transported by the garbage truck to be disposed of in the Final Waste Disposal Site. The transport of waste to the final disposal site will only solve the problem of solid waste generation in an area but will cause problems for the environment of the landfill. Mostly waste management in university still applies conventional methods in which all the wastes will be collected and transferred to the nearest waste collecting points and then will be transported by scavenger truck to be disposed of in the final waste disposal site or final landfill. Transporting waste to the final disposal site will only solve the problem in the university area, but will cause problems for the environment of the landfill. The lack of capability to manage, recycle, and reuse the dump of waste has caused environmental problems. Moreover, it is often reported that plastic waste fills the oceans and kill many animals who eat it. In consequence, waste management as one of many approaches in green engineering can contribute to minimizing the impact of environmental damage that can affect human health. Waste management is better started from waste sources to shorten the process. By providing sorted garbage bins,

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sorting the type of waste, separating between organic waste and inorganic waste, and improving waste sorting behavior can be the earliest step in waste management and speed up the process. Sorted garbage bins labeled according to their types such as organic waste, plastic waste, paper waste, and other waste should be placed at several points in university.

2.3 Assessment of the Sustainability of the Waste Management System to Realize a Green Campus The green campus program has six assessment categories. The six assessment categories are Structuring and Infrastructure; Energy and Climate Change; Waste; Water; Transportation; along Education and Research (Sari 2018). The implementation of green engineering principles in the university area, especially in the category of campus waste management will be explained in this chapter. As a green engineer, studies and assessments of in the university area and the process must be carried out thoroughly to determine the value of sustainability. Moreover, based on the study and assessment of the region and process, it can be seen what factors still have risks or potential hazards both for human health and the surrounding environment. Green Engineering Spatial Assessment, especially in the university area, can use the assessment methods issued by the University of Indonesia. In 2010, the University of Indonesia has developed the university ranking system and has tried to find out about the sustainability in University area known as the “UI GreenMetric World University Rankings”. Continuous programs and policies in Green Campus around the world can be identified based on online survey methods, where each university as a participant will collect and send category data and predetermined ranking indicators. There are 6 categories as the parameters for the realization of the sustainability of the green campus, namely: Structuring and Infrastructure, Energy and Climate Change, Waste, Water, Transportation, Education, and Research. The 6 categories in the GreenMetric assessment have derived to 39 assessment indicators (Sari 2018). The research method applied in the assessment “UI GreenMetric World University Rankings” refers to the criteria weight in each category and indicator. Assessment of each category and indicator has been formulated in numbers statistically. The university which will take part in the “UI GreenMetric World University Rankings” is asked to fill the form, collect files, or send the file via email. And The GreenMetric in Campus Area will be determined based on the completeness of the documents in the assessment of the six categories of questionnaires. The number or response in each category and indicator will be valued and processed, then the gross value will be multiplied by the weighted score that has been determined to get the final value (Sari 2018).

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Fig. 1 Waste management system in Universitas Gadjah Mada. Source Author’s research 2016

3 Results and Discussion 3.1 Case Study of Waste Management System in Universitas Gadjah Mada Universitas Gadjah Mada campus has declared a green campus since 1986, when it was led by Prof. Koesnadi Hardja Soemantri as a rector of Universitas Gadjah Mada. The waste management system at Universitas Gadjah Mada is an integrated waste management system. Universitas Gadjah Mada’s waste management system has a standard operational procedure (SOP) on handling waste generation from waste sources to waste management and its use. Garbage generation is separated by type. Universitas Gadjah Mada provides trash bins in every building and has different labels and colors according to its type. The type of garbage in Universitas Gadjah Mada is divided into organic waste, inorganic waste (plastic and paper), and other waste. Garbage from each building is then collected at a garbage collection point or called a garbage depot. The garbage that has been collected in the garbage depot will be transported to a garbage processing facility or integrated landfill every morning. Universitas Gadjah Mada has a waste processing unit, especially organic waste, which is mostly dominated by garden waste and a small portion of plastic waste. Incurable waste generation will be disposed of in the Integrated Waste Disposal Site. Landscaping waste is processed into compost which can be used as fertilizer for plants or trees owned by Universitas Gadjah Mada (Fig. 1).

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3.2 Implementing the 12 Principles of Green Engineering in Universitas Gadjah Mada The Universitas Gadjah Mada waste management system has applied the green engineering principle to support sustainable development. The implementation of the 12 principles of green engineering is expected to reduce the impact of waste generation on environmental damage and the potential danger to human health. The implementation of the green engineering principle must also consider financial factors or economic feasibility from input to system output. The academic community also has an important role in implementing and monitoring matters that affect the waste management system. Table 1 shows the implementation of the green engineering principles at Universitas Gadjah Mada.

3.3 Examples of Assessments GreenMetric Universitas Gadjah Mada technically has not followed the GreenMetric UI rating system, but based on the guideline of the Universitas Gadjah Mada assessment system can find out the magnitude of the sustainability score of the green campus program on existing conditions. UI GreenMetric has six parameters or categories to assess the sustainability of the green campus program and one of them is the problem of garbage. The waste parameter has six indicators consisting of a program or campus policy regarding waste generation and recycling, processing of organic and inorganic waste, handling of toxic waste, and liquid waste disposal. The indicator of campus waste assessment has a total value of 18% of the total parameters (Sari 2018). Assessment of waste management systems at Universitas Gadjah Mada can be seen in Table 2. Based on the results of interviews and research, Universitas Gadjah Mada has a total value/weight of 10.50% of a maximum weight of 18%. With this score, the sustainability of the waste management system is considered quite good. a. Recycling program for university waste Universitas Gadjah Mada has a campus waste recycling program and can handle up to 50% of the waste generated in the campus area. In supporting the campus waste recycling program, in 2014 Universitas Gadjah Mada has a Standard Operational Procedure for handling waste from the depot to the place of processing and final waste disposal. The waste that is recycled by Universitas Gadjah Mada is organic waste which mostly comes from leaf waste. The collected leaf waste is then processed at the House of Recycling Innovation, Universitas Gadjah Mada’s Agro Technology Innovation Center (PIAT) into organic fertilizer through the composting method. In addition to leaf waste, PIAT also has plastic waste processing technology, especially those derived from used plastic bottles in the form of pyrolysis. Pyrolysis results in the form of fuel can be used as additional energy or energy to run incinerators.

Green engineering principles

Inherent rather than circumstantial

Prevention instead of treatment

Design for separation

Maximize mass, energy, space, and time efficiency

Output-pulled versus input-pushed

No.

1

2

3

4

5

(continued)

Leaf waste produced at Universitas Gadjah Mada is processed into compost. The composting process does not require a lot of human resources because this process has a long processing time between 15 and 60 days. If the composting process is not in progress, the waste processing employees can process other types of waste such as plastic into fuel

Organic waste is a type of waste with the largest volume compared to other types of waste so that composting technology is the right technology with consideration of the availability of raw materials throughout the year, the energy required is not too large, Universitas Gadjah Mada has sufficient land during the process that can streamline processing time

Garbage at Universitas Gadjah Mada is generally divided into 4 types, namely organic waste, plastic waste, paper waste, and other waste. Waste segregation is intended to facilitate the processing process so that the waste produced is more useful and does not cause negative impacts on the environment

Universitas Gadjah Mada has compiled a program to reduce waste generation from its source. Lecturers and employees are encouraged to use electronic correspondence programs, while student assignments can be sent via email

Universitas Gadjah Mada has compiled a Waste Management Standard Operating Procedure in 2014. Waste collected in the waste depot is organic, plastic, paper, and other waste that is harmless or toxic. While hazardous waste is collected at special depots for further processing by third parties

Implementation

Table 1 Implementation of the green engineering principles at Universitas Gadjah Mada

156 A. Kusumawanto and M. Setyowati

Green engineering principles

Conserve complexity

Durability rather than immortality

Meet the need, minimize excess

Minimize material diversity

Integrate local material and energy flows

No.

6

7

8

9

10

Table 1 (continued)

(continued)

Leaf waste is a local material used during the process. Availability of locally available raw materials that will easily save energy and employee time during the composting process

The composting process is a process that does not require too much additional material. In addition to organic waste, the material used is only activator and water as supporting material for the fermentation process

Composting technology is considered more effective when compared to other technologies in terms of handling organic waste. This has a reason that the area of Universitas Gadjah Mada has many vegetation plants or trees so that compost is needed

Waste processing technology must have an age target that lasts relatively long and is not risky for the environment. Composting technology has a long age target because it can be done simply and has no equipment with high complexity

Before determining waste processing technology, Universitas Gadjah Mada has conducted a survey on the type of waste generated every day. The type of waste that is processed is organic waste and some plastic waste especially used mineral water bottles because both types of waste have a low complexity of material properties. Garbage that has high material complexity will be disposed of in landfills for time efficiency

Implementation

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Green engineering principles

Design for commercial “afterlife”

Renewable rather than depleting

No.

11

12

Table 1 (continued)

Composting technology initially only uses a composter tub, but along with raw material quantity and product demand, renewable composting technologies such as windrow composter and rotary composter are needed

Waste generation at Universitas Gadjah Mada which still has selling value and is not processed is not disposed of directly to the final landfill. The waste will be recycled into other products to maintain its value and usefulness. The House of Recycling Innovation (RINDU) teaches visitors to make crafts from garbage Waste generated at Gadjah Mada University cannot all be processed. The accumulation of organic waste produced in the area of Gadjah Mada University is not all processed, only leaf waste through the composting process. The compost produced is then used for fertilizer crops owned by Gadjah Mada University. The generation of inorganic waste, only plastic waste in the form of bottles of used mineral water is processed by the pyrolysis method. The result of pyrolysis is in the form of fuel oil which can be used as an incinerator fuel

Implementation

158 A. Kusumawanto and M. Setyowati

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Table 2 GreenMetric scoring in solid waste management at UGM No.

Criteria and indicators

Score green metric

UGM points

Waste (WS) Recycling program for university waste WS1

Not applicable

0

Partial (1%–25% of waste)

0.25 × 300

Partial (>25%–50% of waste)

0.50 × 300

Partial (>50%–75% of waste)

0.75 × 300

Extensive (>75% waste free)

1.00 × 300

150

Program to reduce the use of paper and plastic on campus WS2

Not applicable

0

1 Program

0.25 × 300

2 Programs

0.50 × 300

3 Programs

0.75 × 300

More than 3 programs

1.00 × 300

150

Organic waste treatment WS3

Open dumping

0

Partial (1%–25% treated)

0.25 × 300

Partial (>25%–50% treated)

0.50 × 300

Partial (>50%–75% treated)

0.75 × 300

Extensive (>75% treated and recycled)

1.00 × 300

300

Inorganic waste treatment WS4

Burned in open area

0

Partial (1%–25% treated)

0.25 × 300

Partial (>25%–50% treated)

0.50 × 300

Partial (>50%–75% treated)

0.75 × 300

Extensive (>75% treated and recycled)

1.00 × 300

150

Toxic waste treatment WS5

Not managed

0

Partial (1%–25% treated)

0.25 × 300

Partial (>25%–50% treated)

0.50 × 300

Partial (>50%–75% treated)

0.75 × 300

Extensive (>75% treated and recycled)

1.00 × 300

Untreated into waterways

0

Treated conventionally

0.25 × 300

225

Sewerage disposal WS6

Weight

Treated technically

0.50 × 300

Treatment for down cycling

0.75 × 300

Treatment for upcycling

1.00 × 300 1800

75

1050

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b. Program to reduce the use of paper and plastic on campus In order to support the paper waste reduction program on campus, Universitas Gadjah Mada has implemented a correspondence program, especially for lecturers and employees and calls for the use of two-sided paper. In addition, students can collect coursework or final assignments via e-mail to reduce the amount of paper usage on campus. c. Organic waste treatment The percentage of the amount of organic waste produced at Universitas Gadjah Mada is 41.53–79.03% (Setyowati et al. 2018). Based on the 2016 waste survey report issued by the Directorate of Assets of Gadjah Mada University, the average generation of waste generated is 2595.8 kg/day (Aset 2016). The waste is then taken to “RINDU” to be processed into fertilizer with composting technology. Composting technology owned is Indore heap, which has a 60 day processing time and windrow composter which has a 45 day processing time (Setyowati et al. 2018). In addition, there is a rotary composter that has a processing time of up to 15 days shorter than the 2 composting technologies that have been running. With the three technologies owned, RINDU as UGM’s waste management manager can process waste more than 75% of the total waste generation. d. Inorganic waste treatment Inorganic waste produced by Universitas Gadjah Mada is divided into three types, namely plastic waste 0.88–18%, paper waste 1.96–25.10%, and other waste 4.01–37.27% (Setyowati et al. 2018). Recycling Innovation House (RINDU) besides processing organic waste also processes inorganic waste, although its capacity is not as big as in the processing of organic waste. Inorganic waste processed is a plastic waste and processed with pyrolysis technology with a tool capacity of 30 kg/h. Inorganic waste that cannot be processed in the pyrolysis process is then burnt in an incinerator, which has a capacity of 20 kg/h. The pyrolysis process produces about 1–2 L of fuel oil, which is then used as incinerator fuel (Setyowati et al. 2018). e. Toxic waste treatment Toxic waste at Universitas Gadjah Mada comes from the remnants of practicum or research. Toxic waste has been handled but not recycled by Universitas Gadjah Mada. The waste has its own shelter/depot (e.g.,: southern mechanical engineering workshop). The toxic waste that is disposed of is then classified, then every 6 months will be transported using containers to Cileungsi to be handed over to third parties. f. Sewerage disposal The liquid waste produced at Universitas Gadjah Mada can be divided into greywater and blackwater. Greywater in the form of liquid waste originating from the canteen kitchen. The handling of liquid waste from the canteen kitchen will be handled conventionally by each canteen manager. While blackwater is in the form of liquid waste originating from latrines. Management of liquid waste in the form of urine and

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feces originating from each building, uses an on-site wastewater treatment system. Urine and feces flown toward the septic tank in each building, and in the septic tank, there is a decomposition process by microorganisms.

4 Conclusion Sustainability has three main pillars, namely economic, social, and environmental. Green engineering and green architecture use these three pillars as the basis of the concept whereby, in a system or process must have economic feasibility that can maximize human welfare but still calculate risk factors for humans and the environment. Green engineering has 12 principles that can be applied in the university to support the sustainability of the campus waste management system as one of the green campus programs and then can be assessed using the GreenMetric UI assessment method. Universitas Gadjah Mada has implemented the 12 principles of green engineering from the start of the preparation of the Standard Operational Procedure system for managing campus waste to the selection of renewable waste processing technology in accordance with the type of campus waste generation. Based on the GreenMetric assessment method, Universitas Gadjah Mada has a sustainability score of 10.50% from a total of 18%.

References Anastas, P. T., & Zimmerman, J. B. (2007). Design through the 12 principles of green engineering. IEEE Engineering Management Review, 35(3), 16. https://doi.org/10.1109/EMR.2007.4296421. Aset, D. (2016) Laporan Survei Sampah UGM. Yogyakarta. Matsufuji, Y. (2004) In First International Workshop on Sustainable Habitat Systems—Concept and Technology—Environment, pp. 00–18. Sadiku, M. N. O., Nelatury, S., & Musa, S. M. (2018). Green engineering: A primer. Journal of Scientific and Engineering Research, (August), 3–7. Sari, R. F. (2018) UI GreenMetric World University Ranking. Jakarta. Setyowati, M., Kusumawanto, A., & Prasetya, A. (2018) Study of waste management towards sustainable green campus in Universitas Gadjah Mada. Journal of Physics: Conference Series, 1022(1). https://doi.org/10.1088/1742-6596/1022/1/012041. Sonnemann, G., & Margni, M. (2015) Life cycle management, information & management. In G. Sonnemann & M. Margni (Eds.). Springer. https://doi.org/10.1016/0378-7206(81)90003-3.

Sustainable Waste Management in Higher Education Institutions—A Case Study in AC Tech, Anna University, Chennai, India Jayapriya Jayaprakash and Hema Jagadeesan

Abstract Educational institutions are major contributors to municipal solid waste (MSW) such as vegetable wastes (cooked and uncooked), leftover food, packaging materials, papers, plastics, rags and other fabrics, dust, ash and a variety of combustible and noncombustible substances. Approximately, 500 kg/d of vegetable and food waste from the canteens and mess and 8,000 kg/month of paper and hardboards are generated in the educational institutions with a footfall of 12000 persons per day. The key problems faced by the institutions due to solid waste generation are (i) cost of disposing the waste appropriately, (ii) clogging of drains due to dispersal of the waste into the surrounding and (iii) vector breeding apart from the contamination of soil from these wastes. Therefore, appropriate collection and disposal of generated solid waste is crucial in MSW management. Nowadays, institutions focus on minimizing the amount of waste generates and maximizing the value-added products extracted from them. This chapter enlightens the importance of solid waste management in the educational institutions and responsibilities of the institution for proper waste treatment. Keywords Solid waste management · Educational institution · Composting · Sustainability

1 Introduction Higher educational institutions accommodate young adults. This target group is a very important one in all aspects of nation-building. A community can be clean only if all sectors of it practice proper waste management. Institutions, especially J. Jayaprakash (B) Department of Applied Science and Technology, A.C. Technology, Anna University, Chennai 600025, India e-mail: [email protected] H. Jagadeesan Department of Biotechnology, PSG College of Technology, Coimbatore, Tamil Nadu, India © Springer Nature Singapore Pte Ltd. 2020 A. Z. Yaser (ed.), Green Engineering for Campus Sustainability, https://doi.org/10.1007/978-981-13-7260-5_12

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higher education institutions, are high population density areas; although majority are present onsite only for part of the day, they do generate a large volume of waste which needs to be managed properly for maintaining the campus cleanliness. Apart from the teaching campuses, the residential areas (hostels, on-campus residences of staff) also generate waste. The major waste categories are the papers, plastics and wrappers, food wastes, yard waste, etc. Proper management of solid waste in the institutions requires segregation of waste at source that is important. It is mandatory that all the stakeholders in the institution cooperate for the sustainability of the clean and green campuses. Moreover, as these young adults are going to be the future policymakers, it is very important to understand their attitudes and inculcate in them the need for appropriate waste management. The propaganda for Swatch Bharat has made people aware of keeping their environment clean and they are slowly moving out of the NIMBY (Not in My Backyard) attitude. It is high time this momentum is increased so as to ensure the success of this movement.

2 Solid Waste Disposal and Management in the Educational Institution There exist a major difference between household waste management and institutional waste management. Apart from the area to be covered, volume of waste generated and the number of persons involved, the transient nature of the population in the institutions creates their own limitations for successful waste management. In a survey conducted by the authors’ (unpublished data) students as well as staff are aware of the need to source segregate waste but there is a wide gap between this awareness and practice similar to situations elsewhere (Barloa et al. 2016). Even those who are aware of the need to source segregate do not know how to do it properly, there is willingness to separate which corresponds to the level of awareness (65% of the surveyed persons were willing to segregate) but only 35% of them practice segregation.

2.1 Sources of Waste in Educational Institution and Types of Waste Solid waste generated in the institution campus from the following major sources such as (i) administrative offices, (ii) classrooms, (iii) hostel, (iv) canteen, (iv) sports complex and (v) other amenities such as bank, ATMs, post office, health centre, etc. In general, solid waste can be classified into four different categories: (i) dry waste, (ii) wet waste, (iii) hazardous waste and (iv) electronic waste. Different types of waste are generated from the waste generators in the campus as shown in Table 1.

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Table 1 Types of waste generated S.no.

Types of waste

Items

1

Dry waste

Plastic water cans, cardboards, waste paper, used perfume bottles, plastic carry bags, aluminium foils, old furniture, and sofa

2

Wet waste

Vegetable and fruit peels, yard trimmings; rotten fruits and vegetables, expired food items leftover food items, used tea leaves and coffee grounds, eggshells, etc.

3

Hazardous waste

Napkins, unused paints and chemicals, expired medicines and cosmetics, pesticides and insecticides, fused bulbs, etc.

4

Electronic waste

Batteries, electronic scrap parts, monitor, mouse, keyboard, etc., laptops, printers, etc.

2.2 Waste Segregation The major constraints for the source segregation seem to be the availability of infrastructure and time. It has been noted that the practicing of source segregation is usually in line with the demand. Other aspects of waste management also are as per the requirements set by the collection system in the community (Davies et al. 2006). So, the requirement of suitable infrastructure for separating the different waste categories is mandatory. In households, this is much easier to achieve than in large areas of the institutions. Appropriate receptacles have to be placed in relevant areas for the success of source separation. This mandates understanding of the types of waste generated in different areas in the campus, for example, classrooms generate more of paper waste, whereas canteen and dining areas generate more of food waste. So the size of collection bins in these areas has to be appropriate for the specific waste generated; at the same time, one cannot exclude the presence of food waste in the classrooms (albeit in smaller volumes); so provision has to be there for these wastes near the classroom areas. This would automatically reduce the time they have to spend in going and finding appropriate bins to put the waste. Different coloured bins such as green (wet waste), blue (dry waste) and red (hazardous waste) must be used to discard the different types of wastes (primary segregated). The bins are to be collected by sanitation workers from different waste generators and dumped in the segregation shed. One of the major concerns in creating awareness in this setup is the peer group pressure and the attitude of adolescents. Some of them would not want to follow set rules. It is important to cater to this group as they might discourage those who are practicing proper segregation. One way of reaching out to these groups is to involve them all through student activities.

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2.3 Waste Management and Methods of Waste Disposal Waste minimization is one of the major thrusts of waste management. Student activities could focus on reducing the waste generated. Another aspect is reuse. If student groups can plan for supporting needy with the excess food or donating their clothing and other reusable accessories to the needy or reusing papers, the much needed minimization of waste requiring treatment will be achieved. An ideal waste management technique should be simple, cost-effective and easily scalable and comply with the 7 R’s in waste management to ensure sustainability of a green campus (Fig. 1). The other thrust is developing technologies for onsite treatment. Transport of waste to treatment facilities is as much of an issue as the first step of source segregation. There would be higher degree of compliance if the stakeholders could observe the final product of waste management, whether be it reduced wastes or recycled wastes. One of the reasons for reluctance to source segregation in many communities is that if all waste is to be landfilled, what is the purpose of source segregation. Different methods used for solid waste treatment in educational institutions include (i) recycling, (ii) composting, (iii) incineration and (iv) landfill. The merits and demerits of different methods for solid waste disposal are outlined in Table 2.

Choose the products with simple packaging. Borrow rather than buy if possible Carpooling, walking and usage of public transport Usage of e-media for news and magazines

What we buy Why we buy Mode of disposal

Do not buy anything which are not really needed

Refuse disposable where appropriate Buy only what is needed/avoid impulse buying

Fig. 1 7 R’s in waste management

Pick durable products over single use material Replace paper towels with hand dryers or cloth towels

Donate unwanted clothes and household items Use reusable cutlery Use one side printed paper for rough work Opt for recycled products

Energy recovery from incineration Manure from composting

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Table 2 Different methods for solid waste disposal (Gray 2002) Method

Advantages

Disadvantages

Recycling

• Reduces the demand for new materials • Reduces water and air pollution caused by landfills • Reuse of waste paper can reduce deforestation and protect the environment • Minimizes combustion and emission of greenhouse gases • Reduces energy consumption • Conserves natural resources

• Questionable durability of recycled material • High upfront capital costs of recycling units • Low demand for recycled products

Composting

Final product used for • Soil amendment • Fertilizer supplement

• Chances of bad odour • Limited flexibility to handle changing • Conditions needed are maintenance-intensive • Uncertainty of nutrient composition in final products

Incineration

• • • • •

• Expensive • Smoke production—acid gases, carcinogen dioxin, particulates, heavy metals and nitrogen oxide. • Ash waste can potentially harm people and environment

Landfill

• Cost-efficient • Monitoring of disposal location is possible • Recyclables can be recovered

Reduces landfill Reduces water pollution Production of heat and power Decreases quantity of waste Saves on transportation of waste

• Rotting food generates greenhouse gases like methane and carbon dioxide • Risk of chemicals leaching into the groundwater and streams

3 Case Study Considering the infrastructure available for proper treatment of waste in larger scale, small- or medium-scale onsite treatment and management is much preferable if space permits. This will also help in ensuring proper adherence of the community members to the norms. One such trial was done in the campus of a higher education institution with specific waste streams. The waste management hierarchy suggests resource recovery before waste disposal, and an environmentally friendly one would be to reduce waste generation followed by reuse and composting rather than incineration or landfill (Giusti 2009). Institutional wastes are of low calorific value and thus cannot be used for efficient energy recovery through incineration (Rand et al. 2000). As the major portion of waste generated in the educational institutions are organic wastes (food waste, yard waste, paper waste, etc.), composting can be a cost-effective waste reduction process and leads to resource recovery. Composting is the natural biological process

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consisting of decomposition of organic matter by microorganisms into compost that is stable, free of pathogens and can be used as soil amendment. In general, there are three types of composting—aerobic (with oxygen), anaerobic also known as trench composting (without oxygen) and vermicomposting (Sinha and Sinha 2016). Generally, composting process occurs in three phases such as mesophilic, thermophilic and curing. In the first phase, acid-producing bacteria such as Lactobacillus spp. and Acetobacter spp. metabolize carbohydrates, sugars and proteins. During this phase, the temperature of the composting increases from ambient to 40 °C. In the second phase, thermophilic bacteria such as Bacillus spp. and Actinobacteria are involved in the protein and lipid metabolism, and it reaches the temperature of 40–70 °C. The last curing phase (cooling phase) composting is a long time process where the nutrients in the compost become depleted, and simultaneously slows down the metabolic activity of microorganisms (Epstein 1996). As a result, heat generation is gradually decreased, and the compost becomes dry and crumbly texture. Several factors such as oxygen, temperature, moisture, C:N ratio, particle size, pH, aeration rate, etc. are affecting the growth of microorganisms (Makan et al. 2013), and thereby the optimization of these parameters has a great influence on the rate of composting and quality of composts. The current study was conducted in an educational institution with a footfall of 12000 persons/day in Anna University, Chennai, India. This study aimed to determine the feasibility of in-vessel composting to treat yard waste generated inside the campus and also evaluates the effect of additives (food wastes and paper waste) in cocomposting. Yard waste was prepared by mixing browns and greens at an arbitrary ratio of approximately 1:1 (dry content basis), respectively. Browns include dried fall leaves and wooden debris in the ratio 2:1. Greens includes fresh plant materials and grass clippings. Other additives were mixed with yard waste (CY) in proportions (2:1) that resulted in acceptable C: N ratios (5:1–25:1). The feedstock combinations were as follows: • • • • • •

Yard wastes (dried fall leaves: grass clippings: wooden debris, 1:1:1) (CY). Yard wastes + vegetable waste (2:1), (CYV). Yard wastes +fruit wastes (2:1) (CYF). Yard wastes + spent coffee grounds (2:1) (CYCo). Yard wastes + spent tea leaves (2:1) (CYT). Yard wastes + paper waste (2:1) (CYP).

Three kg of feedstock in various combinations as described above was chosen as feedstock. The experiments were run in closed, perforated cylindrical vessel (30L capacity) in three replicates per treatment. The drums are of diameter 50 inches and height 48 inches approximately ensuring to hold a capacity of 3 kg of waste with head space for good aeration (Fig. 2). They were watered as required, and no extra fertilization was applied. Aeration was facilitated by perforation of diameter about 0.5 cm. The composts were characterized in terms of total solids, volatile solids, pH, electrical conductivity (EC), total organic carbon (TOC), total Kjeldahl nitrogen (TKN), carbon: nitrogen ratio (C:N ratio), micronutrients like Fe, K, Mg, Ca, P, Na, microbial population, stability index, seed germination test, heavy metal content and

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Fig. 2 In vessel composting–cylindrical vessel (30L capacity)

heavy metal uptake (Febrisiantosa et al. 2018). Compost maturity and stability was analysed in terms of C/N ratio, stability index and seed germination index. The physicochemical characteristics of the different composts are given in Table 3. A mature compost should have an C:N ratio ≤ 25, and it is an indicator of compost stability (Woods End Research Laboratory 2005). The C: N ratio of all the different composts (except CYP) produced in this is 25:1, which satisfies the basic requirements for compost. Another parameter, stability index based on CO2 evolution, has also been used for the evaluation of compost stability. The composts are considered to be to be stable if the index has a value lesser than 2 mg CO2 g−1 compost day−1 (Tinoco et al. 2004). The respiration rates of different composts such as CY, CYF, CYT and CYCo were lesser than 2 mg CO2 g−1 compost/day, and it showed that the composts are not phytotoxic to seedlings and would be considered stable (Sangamithirai et al. 2015). Synthetic fertilizer is typically high in nitrogen, phosphorous and potassium; however, the composts from yard waste co-composting are often high in iron when compared with other micronutrients. However, the presence of heavy metals in composts is the main cause of adverse effect on human health, transmitted through the food chain from the plants (Gigliotti et al. 1996), and it was essential to analyse the contents of heavy metal in composts. Heavy metal levels in the different composts from the institutional wastes did not exceed the limits for application of compost as a soil amendment recommended by the US EPA.2000 (EPA 2000). Each type of compost has its own merits and demerits (Table 4) so that it can be formulated with other ingredients to improve the soil structure and plant nutrition.

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Table 3 Physicochemical characteristics of the different composts (Sangamithirai et al. 2015) Feedstock

EC dS/m

TKN in mg/g

C:N

Stability index (mg CO2 – g−1 compost day−1 )

N (mg/g)

P (ppm)

K (ppm)

CY (1:1)

5.9 ± 0.5

17.2 ± 0.1

10.75 ± 1.6

1.41 ± 0.1

17.2 ± 0.1

1200 ± 1.2

1050 ± 0.3

CYF(2:1)

4.9 ± 1.5

19.9 ± 1.1

11.10 ± 2

2.4 ± 1.2

19.9 ± 1.1

1724 ± 2.2

1480 ± 0.1

CYCo(2:1) 6.7 ± 0.8

3.76 ± 0.3

16.9 ± 3.1

1.06 ± 0.5

3.76 ± 0.3

1775 ± 1.8

1059 ± 0.4

CYT(2:1)

7.2 ± 0.2

29.4 ± 1.2

9.1 ± 2.3

1.14 ± 0.3

29.4 ± 1.2

3465 ± 1.4

1075 ± 0.2

CYV(2:1)

9 ± 0.5

20.4 ± 0.4

19.85 ± 0.4

8.6 ± 0.9

20.4 ± 0.4

1795 ± 3.1

1066 ± 0.0

CYP(2:1)

8.1 ± 1.1

9.67 ± 0.7

47.25 ± 2.8

7.3 ± 0.4

9.67 ± 0.7

1354 ± 0.8

1007 ± 0.1

CYM(2:1) 9.6 ± 0.9

18.44 ± 1.8

16.97 ± 1.2

8.82 ± 1.8

18.44 ± 1.8

2823 ± 4.1

1042 ± 0.5

Table 4 Merits and limitations of the different composts Composts

Merits

Limitations

Recommendations

CY (1:1)

Highly stable, neutral pH, Ca- and Mg-rich compost and high uptake of Cr

Comparatively low phosphorus

Amendment with phosphate salt such as Na2 HPO4

CYF(2:1)

Stable, neutral pH, Kand Mg-rich compost

High Ca in the compost may form complex with other nutrients, and thereby it affects the plant growth

–

CYCo(2:1)

Stable. Na- and Fe-rich compost

N is quite less

Amendment with urea

CYT(2:1)

Stable. High content N, P, and balance nutrients of Ca, Mg and Na

–

–

CYV(2:1)

Nitrogen-rich compost

High EC and Na rich compost

Soil additive gypsum may be added with compost

CYP(2:1)

Carbon-rich compost

Nitrogen levels are low. High EC

Amendment with urea

CYM(2:1)

High phosphorus. Provide the rapid root growth

EC is high. Low Ca and high Na levels

Soil additive gypsum may be added with compost

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4 Conclusions Higher education institutions have the challenge of source segregation and management of wastes. The possibility of transient population requires proper awareness creation about source segregation. Notifications and instructions at appropriate places, along with suitable infrastructure, would result in proper source segregation of waste generated. It has been demonstrated that source segregated wastes could be effectively treated on-campus by many institutions, including for use in biogas generation and compost preparation. The effectiveness of the on-campus waste management strategy would depend on source segregation, and this requires the cooperation of all stakeholders.

5 Recommendations To practice the solid waste management in any educational institution in a successful way, the key components are implemented as follows: 1. The management of an institution shall provide the following facilities for a sustainable green campus: (a) (b) (c) (d)

Different colour coded bins for waste storage and collection; Adequate sanitation workers and officers for waste management; Equipment such as shredder/crusher, incinerator, composter or biogas plant; Space for waste storage and segregation shed, which are protected against infestation by insects, rats, birds and animals; and (e) Proper transportation for waste disposal

2. Must not allow dumping inside the campus. 3. Create opportunities to recover resources from waste. 4. Every person should get trained to identify the type of waste and segregate properly into the three different categories (Wet/Dry/Hazardous) before handling them over to waste collectors. 5. Create awareness among the students, staff and workers in various centres inside the campus and residents by conducting the cultural events, activities and drills on waste management so that they understand the consequences of improper waste management and its impact on human health and environment. 6. Appreciate, encourage and honour people who contribute substantially to maintaining the campus green by awarding with a certificate of appreciation. 7. Workers involved in waste segregation and disposal should be provided with proper personal protective equipment (PPE) such as waterproof gloves, face masks, goggles, rubber boots, etc. 8. Training must be provided to the workers on the following aspects: (a) understand the potential risks associated with waste handling and disposal, (b) importance

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and proper usage of personal protection equipment (PPE) and (c) value of immunization against viral hepatitis and tetanus.

References Andi, F., Ravindran, B., & Choi, H. L. (2018). The effect of co-additives (Biochar and FGD Gypsum) on ammonia volatilization during the composting of livestock waste. Sustainability, 10(3), 795. https://doi.org/10.3390/su10030795. Anna, D., Taylor, D., Fahy, F., Meade, H., & O’Callaghan-Platt, A. (2006). Environmental attitudes and behaviour: Values, actions and waste management. Final Report of Environmental RTDI Programme 2000–2006. Environment Protection Act, Ireland. Barloa, P. E., Lapie, L. P., & de la Cruz, C. P. P. (2016). Knowledge, attitudes, and practices on solid waste management among undergraduate students in a Philippine State University. Journal of Environment and Earth Science 6(6), 146–153. EPA, US. (2000). Biosolids technology fact sheet: In-vessel composting of biosolids. United States, Environmental Protection Agency; Office of Water; Washington, D.C. http://purl.access.gpo.gov/ GPO/LPS50760. Epstein, E. (1996). The science of composting. CRC Press. Giovanni, G., Businelli, D., & Giusquiani, P. L. (1996). Trace metals uptake and distribution in corn plants grown on a 6-year urban waste compost amended soil. Agriculture, Ecosystems & Environment, 58, 199–206. Giusti, L. (2009). A review of waste management practices and their impact on human health. Waste Management 29(8), 2227–2239. https://doi.org/10.1016/j.wasman.2009.03.028. Gray, M. (2002). Waste management and public health: The state of the evidence. Project Report. South West Public Health Observatory. http://eprints.uwe.ac.uk/3504. Makan, A., Assobhei, O., & Mountadar, M. (2013). Effect of initial moisture content on the invessel composting under air pressure of organic fraction of municipal solid waste in Morocco. Iranian Journal of Environmental Health Sciences & Engineering 10(1), 1–9. https://doi.org/10. 1186/1735-2746-10-3. Mridula, S., & Sinha, R. K. (2016). Swachh Bharat. In Swachh Bharat (p. 88). Prabhat Books. Pilar, T., Almendros, G., Gonzalez-Vila, F. J., Lankes, U., & Ludemann, H.-D. (2004). Analysis of carbon and nitrogen forms in soil fractions after the addition of 15 N-compost by 13 C and 15 N nuclear magnetic resonance. Journal of Agricultural and Food Chemistry, 52, 5412–5417. https://doi.org/10.1021/jf0496604. Rand, T., Haukohl, J., & Marxen, U. (2000). Municipal solid waste incineration: Requirements for a successful project. World Bank Technical Paper No. WTP (Vol. 462, pp. 103). Washington, D.C. Sangamithirai, K. M., Jayapriya, J., Hema, J., & Ravi, M. (2015). Evaluation of in-vessel cocomposting of yard waste and development of kinetic models for co-composting. International Journal of Recycling of Organic Waste in Agriculture, 4(3), 157–165. https://doi.org/10.1007/ s40093-015-0095-1. Woods End Research Laboratory. (2005). Interpreting waste and compost tests. Journal of the Woods End Research Laboratory, 2(1), 6.

Food Waste Composting at Faculty of Engineering, Universiti Malaysia Sabah Sariah Saalah, Mariani Rajin, Abu Zahrim Yaser, Nur Ain Syafiqah Azmi and Ahmad Fathuddin Fikri Mohammad

Abstract The initiative of campus sustainability has been introduced in Universiti Malaysia Sabah (UMS) in 2013, through the establishment of UMS EcoCampus Management Centre. Waste management is one of the EcoCampus management strategies. In this work, waste audit was conducted to determine food waste generation at the cafeteria of Faculty of Engineering, UMS. Food waste is the major group of waste generated which is equivalent to 75% of total waste collected in four weeks. Around 127.7 kg of food waste is generated per week, with average 25.5 kg per day. The moisture content and density of the food waste were in the range of 75.0–77.5% and 2733 to 3877 kg/m3 , respectively. The food waste collected was combined with dry leaves and successfully used as feedstock for composting process over 55 days. During composting process, the highest temperature achieved was 57 °C on day 25. Interestingly, the maximum intensity of the odour detected at 1 m distance from the composter is considered very weak. In terms of mass reduction, the residual mass after 55 days of composting process is 124.99 kg out of 232 kg, which is equivalent to 46.3% of mass reduction from the total weight of the feedstock. Keywords UMS EcoCampus · Composting · Food waste generation

1 Introduction Waste minimization is at the forefront of campus sustainability initiatives. Universiti Malaysia Sabah UMS) has established the EcoCampus Management Centre in February 2013 as a platform for the university to provide a framework that is to be S. Saalah (B) · M. Rajin · A. Z. Yaser · N. A. S. Azmi · A. F. F. Mohammad Chemical Engineering Programme, Faculty of Engineering, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia e-mail: [email protected] M. Rajin e-mail: [email protected] A. Z. Yaser e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2020 A. Z. Yaser (ed.), Green Engineering for Campus Sustainability, https://doi.org/10.1007/978-981-13-7260-5_13

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implemented, enforced, monitored, assessed and reviewed based on the key elements of the EcoCampus Transformation Plan (Azril 2017a). Interestingly, UMS received first place in the Special Award Category on Green Campus Sustainability in conjunction with the Green Campus Sustainability Convention on 25 May 2017 (Azril 2017b). Waste management is one of the main concerns of EcoCampus. For instance, a program to increase awareness on minimizing waste such as double-sided printing and use of tumbler as a replacement for plastic bottles were actively conducted at the university. Besides, an initiative for waste recycling can be observed with many recycle bins available at every place. However, to the knowledge of the author, there are no updated reports available on the actual waste generation in UMS. Audit of waste in UMS was done in 2006 and found out that the organic waste that mainly consists of food waste represented the largest percentage of 53% (Budin and Praveena 2006). In Malaysia, about 80% of municipal solid waste (MSW) are food waste, paper, and plastic (Aja and Al-Kayiem 2014). Food waste mainly consists of carbohydrates, proteins, lipids, and traces of inorganic compounds. The composition varies in accordance with the type of food waste and its constituents. Proper treatment and management of food waste is a challenge faced by any developing nation as untreated and unmanaged food waste creates odour, hygiene concerns, and cause adverse environmental impacts (Khoo et al. 2010). Therefore, appropriate methods are required for the management of food waste. Currently, various kinds of approaches were investigated in food waste processing and management for societal benefits and applications. Landfilling and incineration are not suitable for the disposal of food waste as food waste contains high moisture and organic matter contents (Fan et al. 2016). Incineration of food waste consisting high-moisture content results in the release of dioxins which may further lead to several environmental problems. Also, incineration reduces the economic value of the substrate as it hinders the recovery of nutrients and valuable chemical compounds from the incinerated substrate (Paritosh et al. 2017). On the bright side, food waste, in general, has high water content with various plant required nutrients and organic matters but is non-toxic, and therefore, it is a good composting material. The composting process is defined as an anaerobic biological process that depends on a microorganism population, which converts the organic substance of the wastes into stabilized humus and less complex compound. In composting, carbon and nitrogen compounds are easily transformed and used as energy and protein sources of microorganisms, thereby producing heat, CO2 , NH3 , H2 O, organic acids and mature compost product at the end of the process (Bernal et al. 2009; Asis et al. 2017). Composting is a process highly valued in waste management owing to its robustness and the possibility of obtaining a valuable product with soil amendment potential (Cerda et al. 2017). This approach is considered as among the most eco-friendly and promising solutions for food wastes management. Composting of food waste

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has been successfully conducted worldwide by various improved composting techniques, for example, applying bulking agent and co-composting (Adhikari et al. 2009; Fan et al. 2016; Zahrim et al. 2016). Bulking agent such as sugar cane bagasse, rice husk, wood chips, chopped wheat straw, wood shavings, waste paper, and dry leaves have received significant attention nowadays (Adhikari et al. 2009; Fan et al. 2016; Zhang and Sun 2018). The bulking agents help to absorb part of the leachate produced during the decomposition process, to keep the mixture moist and sustain an active microbial activity (Iqbal et al. 2010). In addition, bulking agents gives structure and porosity to the mixture for proper aeration (Adhikari et al. 2009). The National Strategic Plan for Food Waste Management in Malaysia (NSPFWMM) was planned and proposed by the Ministry of Housing and Local Government of Malaysia with collaboration with the Japan government’s Ministry of the Environment in 2010. There are six main strategies highlighted which aim to inculcate public with a good habit of food waste disposal including food waste segregation for reducing greenhouse gases emission and reducing land utilization (Lim et al. 2016). In line with this, the Petaling Jaya Municipal Council (MBPJ) has established a pilot-scale composting facility in association with Shence Greentech Sdn Bhd. in 2013. The food waste treatment model by MBPJ probably could be a model for other councils in Malaysia. At research capacity, local tertiary institutions such as Universiti Malaya and Universiti Putra Malaysia have set up a pilot-scale food waste digester (Cowtech CTM-100, CH Green Sdn. Bhd., Kuala Lumpur, Malaysia), which is able to process food waste into liquid fertilizer and biogas at a capacity of 100 kg/day for its Zero Waste Campaign and efforts towards sustainable agricultural farming, respectively (Lim et al. 2016). These motivates further research on this particular area as food waste can be highly variable depending on its source and is strongly dependent on the eating habits of consumers (Cerda et al. 2018). For this reason, local characterization of food waste is important for the accurate design of composting systems. The recipes of compost highly depend on the food waste characteristics (Adhikari et al. 2008). Therefore, in this work, an audit on waste generation in Faculty of Engineering (FKJ) cafeteria UMS has been conducted to quantitatively determine the amount and profile of waste. Food waste was further utilized as composting material with the use of dry leaves as bulking agent. Besides readily available, utilization of dry leaves collected from landscape at FKJ would not require extra transportation cost. Composting process was conducted in a locally fabricated composter.

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2 Materials and Methods 2.1 Materials Waste collected from the cafeteria of Faculty of Engineering, UMS. On the other hand, the dry leaves used in this works is a landscape waste which was collected from Faculty of Engineering campus area.

2.2 Determination of Waste Generation and Profile Waste audit has been conducted in Faculty of Engineering cafeteria (FKJ Cafeteria) UMS to provide food waste generation, according to a method described by Rispo et al. (2015). The waste collected was unloaded on floor of a canvas 2 m2 . The waste collected represented materials disposed by the cafeteria for one day. The collected waste were classified into five category namely food waste, eggshells, bones, plastic, paper, others (glass, aluminium can). The cafeteria wastes were collected every day after lunch hour. Segregation of wastes was conducted immediately after collection, and the volume and weight were determined for each wastes category.

2.3 Physical Characterizations of Food Waste The mass and volume of the segregated wastes were used to determine the densities of food waste. The moisture content was determined by placing the Petri dishes containing 10 g food waste into an oven for 24 h with a temperature of 104 °C (Yaser et al. 2007). The weight of the Petri dish containing the food waste before and after drying was used to calculate the moisture content using Eq. 1: Moistur e Content, % =

w−d × 100 w

(1)

where w is wet weight, and d is dry weight. Statistical Analysis A one-way analysis of variance (ANOVA) was used to perform statistical analysis to determine whether there is a significant difference in mean of waste generation, profile and properties of food waste at four different weeks on which the experiment was conducted. The Excel 2010 for Windows was used for all statistical analysis.

Food Waste Composting at Faculty of Engineering … Table 1 Weight of food waste and dry leaves used as composting material

177

Time (date)

Weight of leaves (kg)

Weight of food waste (kg)

14/2/2018

20

4.9

15/2/2018

–

3.9

19/2/2018

–

8.9

20/2/2018

–

20.9

21/2/2018

35.4

21.6

22/2/2018

11

10

26/2/2018

15.1

16.2

28/2/2018

–

10

1/3/2018

14.9

–

9/3/2018

20

20

Total weight (kg)

116.4

116.4

2.4 Composting of Food Waste Feedstock For composting process, the previously collected food waste from FKJ cafeteria was used as a feedstock, which was combined with dry leaves. Dry leaves were used as a bulking agent to improve aeration of the composting. Table 1 shows the amount of feedstock comprises of dry leaves and food waste that has been fed into the composter for ten consecutive days. Overall, a total of 116 kg of food waste and 116 kg of dry leaves (1:1 by weight) were used as a feedstock. Composting Process Composting of the food waste and dry leaves was performed in feed batch reactors consists of three compartments. Two of the compartments are active zone (compartment A and B), where the composting process was performed. On the other hand, the third compartment is the yield compartment (compartment C), where the end products from the composting process were stored. The dimensions of the compartment are illustrated in Fig. 1. Each compartment was designed to contain 15 holes at the posterior wall with a diameter of 26 mm to facilitate natural air circulation. The holes have been constructed and arranged into three levels; bottom, middle, and top level of the compartment. Two windows were provided for each compartment at the top and anterior wall of the compartment. The configuration for each compartment can be seen in Table 2. Composting process was conducted in Compartments A and B. The waste was turned from compartment A to compartment B and the other way round every 7 days. About 232 kg of the feedstock was subjected to composting for 55 days. Consequently, the compost was weighted to determine the mass reduction of the compost material.

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(a) Two dimensional front view Compartment C

Compartment B

Compartment A

(b) Three dimensional view

Fig. 1 Schematic diagram of composting reactor. a Two-dimensional front view. b Threedimensional view

Food Waste Composting at Faculty of Engineering … Table 2 Configurations of reactors used for composting process

Table 3 Scale for odour test during the composting process

179

Configuration

Reactor 1

Reactor 2

Reactor 3

Window at the top of compartment

Yes

Yes

Yes

Window at the front side of compartment

Yes

Yes

Yes

Holes

Yes

Yes

Yes

Turning

Yes

Yes

No

Grade scale

Description

1

No odour

Odourless

1.5

Very week odour

Not unpleasant

2

Week odour

Not unpleasant

2.5 3

Slightly unpleasant Bearable odour

Not unpleasant

Pestering odour

Slightly unpleasant

5

Unbearable odour

Very unpleasant

6

Extremely unbearable odour

Extremely unpleasant

3.5 4

Slightly unpleasant

4.5

Unpleasant

Monitoring of the Composting Process (a) Temperature profile Temperature of the compost was measured daily by inserting the digital thermometer at the holes of the composter. Temperature reading was taken at three different location which are bottom (T1), middle (T2) and top (T3) of the compartment (Fig. 1). The ambient temperature was also recorded. (b) Odour In this work, the odour was measured qualitatively by scaling the intensity of the odour from 1 (Odourless) to 6 (Extremely unpleasant), as shown in Table 3. Odour test was conducted three times per week, by four different students which was standing at each corner of the composting reactor as shown in Fig. 2. The odour at two different distance was recorded accordingly: 1 and 2 m from the composting reactor.

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Fig. 2 The odour evaluation points at four corners of the composting reactor (Distance between evaluators and composter are 1 and 2 m)

3 Results and Discussion 3.1 Waste Generation and Profile The waste generation was successfully recorded for three consecutive weeks of the school semester starting from 6th of November 2017 until 24th of November 2017 excluding weekends. The data was also recorded on 26th of February 2017 until 2nd of March 2018 for comparison purpose. Total waste generation weekly of FKJ Cafeteria for the whole 4 weeks are shown in Table 4. About 680.2 kg of waste was generated in 4 weeks, with average 170 kg per week, and 33.9 kg per day. From this figure, a total food waste generation per week is around 127.7 kg, and average food waste generation per day is around 25.5 kg. Figure 3 shows the waste composition profile of FKJ Cafeteria. Obviously, food waste is the major group of waste generated at 510.9 kg which is equivalent to 75% of total waste collected in four weeks. This is followed by plastics (9%), paper (7%), bones (5%), eggshells (3%) and others (1%) which includes sponge, diapers, Aluminium can, Tin can, glass bottle, spoon, wire, doorknob and organic lunch box. Since the current audit works were conducted in a cafeteria, the amount of food waste is dominant. For comparison, the portions of food waste in municipal solid waste in developing countries including Malaysia was 51–55%, indicating that it is more convenient to adopt composting as a food waste treatment method in developing nations (Thi et al. 2015).

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Table 4 Waste generation from FKJ Cafeteria UMS Type of waste

Total cafeteria waste generated for total four weeks (kg)

Average cafeteria waste generated weekly (kg)

Average cafeteria waste generated daily (kg)

Food waste

510.9

127.7

25.5

60.9

15.2

3.0

Plastic Paper

47.9

12.0

2.4

Bones

34.1

8.5

1.7

Eggshells

18.4

4.6

0.9

8.0

2.0

0.4

680.2

170

33.9

Others Total

EGGSHELL 3% BONE 5%

OTHERS 1%

PAPER 7% PLASTIC 9%

FOOD WASTE 75%

Fig. 3 Composition of waste collected from FKJ Cafeteria, UMS

3.2 Physical Properties of Food Waste 3.2.1

Food Waste Generation

Figure 4 shows the weight of food waste generated during weekdays, while Fig. 5 shows the percentage of the food waste per total waste generated. Overall, the highest amount of food waste was collected on Wednesday which is 30.9 kg, while the lowest amount collected was on Monday with 23.1 kg. In terms of percentage of food waste per total waste, the value was in a range of 72.4–79.5%. It can be seen that the difference are not much significant for both weight and percentage of the food waste collected for each day. Further statistical analysis of this difference was reported in Sect. 3.2.4.

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Weight (Kg)

30.00 25.00

23.1

23.8

MONDAY

TUESDAY

25.7 23.4

20.00 15.00 10.00 5.00 0.00 WEDNESDAY

THURSDAY

FRIDAY

Days

Food waste (%)

Fig. 4 Weight of food waste collected from FKJ Cafeteria UMS during weekdays 90.00 80.00 70.00 60.00 50.00 40.00 30.00 20.00 10.00 0.00

79.5

MONDAY

73.8

75.9

74.1

72.4

TUESDAY

WEDNESDAY

THURSDAY

FRIDAY

Days

Fig. 5 Portion of food waste in waste collected from FKJ Cafeteria UMS during weekdays

3.2.2

Moisture Content of Food Waste

The moisture contents of food waste generated from FKJ cafeteria during weekdays is shown in Fig. 6. Based on the results, the lowest moisture content value was on Tuesday at 75% while the highest was on Monday (77.2%). However, the error bars shown in Fig. 6 indicates that the difference is not statistically significant. These will be further confirmed by ANOVA analysis in Sect. 3.2.4. The moisture content of food waste collected in this work is in comparison with value reported in other places such as Taiwan (70–80%) and Saudi Arabia (82.6%) (Kumar et al. 2010; Waqas et al. 2018). Moisture content is an important parameter to determine the successfulness of composting. Physical and chemical properties of the waste material change with moisture which acts as a transporting medium of nutrients for microbial activity (Iqbal et al. 2010). Previous studies reported that 50–60% moisture content is suitable for efficient composting (Kumar et al. 2010; Liang et al. 2003). However, the moisture content of food waste is considerably higher. The use of such moisture rich waste mixture in the composting process can create waterlogged or anaerobic conditions (Waqas et al. 2018). Therefore, it is recommended to mix it with carbon-rich material

Moisture Content (%)

Food Waste Composting at Faculty of Engineering … 80.00 78.00 76.00 74.00 72.00 70.00 68.00 66.00 64.00 62.00 60.00

77.2

183

76.8

76.2

75.6

WEDNESDAY

THURSDAY

FRIDAY

75.0

MONDAY

TUESDAY

Days

Fig. 6 Moisture content of food waste collected from FKJ Cafeteria UMS

to correct the C: N ratio and to absorb the excess moisture. Moreover, cooked food waste composter is highly recommended to be mixed with bulking agent such as woodchip, wood pellets or sawdust (‘Carry on Composting’, n.d.). It is important to monitor the moisture content of the composter containing high-moisture food waste such as fruits as they may become too moist. Constant turning to aerate dry coir or adding shredded paper is normally proposed to absorb excess moisture (‘Carry on Composting’, n.d.).

3.2.3

Density of Food Waste

Figure 7 shows density of food waste measured daily. The average density of the food waste was in the range of 2733–3877 kg/m3 , with the highest density recorded on Wednesday and the lowest density recorded on Friday. From the error bars, it can be concluded that the difference in the density value per days was not significant. Generally, different condition of food waste being measured will result in different density values. For instance, raw food waste will result in higher density while processed food waste results in lower density value (Zen et al. 2016). Further statistical analysis will be shown in Sect. 3.2.4 to further confirm if the density is dependent on the days.

3.2.4

Statistical Analysis

Food Waste Generation Table 5 shows the results of one-way ANOVA analyses on the weight of food waste for five days, in 4 weeks. Based on the results, F = 1.128 and p < 0.367, while the critical value of F is 3.239. There is no statistically significant difference in mean for the four weeks listed for analysis at the significance level of 0.05 because the F

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Density (kg/m3)

6000.00 5000.00 3877

4000.00

3216

2918

3000.00

3052

2733

2000.00 1000.00 0.00 MONDAY

TUESDAY

WEDNESDAY

THURSDAY

FRIDAY

Days

Fig. 7 Density of food waste collected from FKJ Cafeteria UMS Table 5 ANOVA to compare mean of the summary of food waste weight collection Groups

Count

Sum

Average

Variance

Week 1

5

151.55

30.31

66.148

Week 2

5

117.25

23.45

47.6525

Week 3

5

121.75

24.35

Week 4

5

120.4

24.08

Source of Variation

9.83 57.56575

SS

df

MS

F

P-value

F crit

1.12837

0.367218

3.238872

ANOVA Between groups

153.3424

3

51.11413

Within groups

724.785

16

45.29906

Total

878.1274

19

statistic obtained is less than the F critical value (1.128 < 3.239). Hence, it can be concluded that food waste weight collection for the 4 weeks was not significantly different from each other. In other words, the weight of food waste was independent of the period the collections. The results of one-way ANOVA on the effect of days on the food waste composition was shown in Table 6. It was determined that F = 4.150 and p < 0.024, while the critical value of F is 3.239. Therefore, there is a statistically significant difference in the composition of food waste collected among the four weeks of data collected at the significance level of 0.05 because the F statistics obtained is greater than the critical value (4.150 > 3.239). Another way to analyze the ANOVA result is by comparing the p-value with the significance (α) level. Since the p-value corresponding to the F statistic of the one-way ANOVA is lower than 0.05, this suggests that at least two means are significantly different from one another. Hence, it can be concluded that the difference in the period of the composition of food waste measured were effectual to result in a significant difference in the food waste composition collection of the four weeks.

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Table 6 ANOVA to compare mean of the summary of food waste composition collection Groups

Count

Sum

Average

Variance

Week 1

5

364.95

72.99

56.24215

Week 2

5

347.25

69.45

19.61365

Week 3

5

398.35

79.67

20.3995

Week 4

5

392.3357

78.46713

13.93328

Source of Variation

SS

df

MS

F

P-value

F crit

Between groups

342.9461

3

114.3154

4.149809

0.023594

3.238872

Within groups

440.7543

16

27.54714

Total

783.7005

19

ANOVA

Table 7 ANOVA to compare mean of the summary of food waste density collection Groups

Count

Sum

Average

Variance

Week 1

5

23728.29

4745.658

2178827

Week 2

5

17500

3500

1061543

Week 3

5

18588.4

3717.68

Week 4

5

Source of Variation

3367.28

174407.7

673.456

87657.59

SS

df

MS

F

P-value

F crit

Between groups

45619084

3

15206361

17.36662

2.76E-05

3.238872

Within groups

14009739

16

875608.7

Total

59628822

19

ANOVA

Density of Food Waste The ANOVA results on the effect of days towards the density of food waste is shown in Table 7, with F = 17.367 and p < 0.0000276. The critical value of F is 3.239. Since the F statistics obtained is greater than the critical value (17.367 > 3.239), it suggested that there is a statistically significant difference in the density of food waste collected among the four weeks of data collected at the significance level of 0.05. On the other hand, the p-value is much lower than 0.05 suggesting that at least two means are significantly different from one another. Hence, it can be concluded that the densities of the food waste were dependent on the period the food waste collection. Moisture Content of Food Waste Table 8 shows the results of one-way ANOVA analyses of the moisture content of the food waste, with F = 1.4 and p < 0.279. The critical value of F is 3.239. There is no statistically significant difference in mean for the four weeks listed for analyses at the significance level of 0.05 because the F statistic obtained is less than the F critical value (1.4 < 3.239). Therefore, it can be concluded that the difference in the period

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Table 8 ANOVA to compare mean of the summary of food waste moisture content collection Groups

Count

Sum

Average

Week 1

5

383.67

76.734

4.69693

Week 2

5

379.18

75.836

6.81348

Week 3

5

384.7

76.94

2.06745

Week 4

5

358.61

71.722

71.32402

Source of Variation

SS

df

Variance

MS

F

P-value

F crit

1.400446

0.279045

3.238872

ANOVA Between groups

89.1754

3

29.72513

Within groups

339.6075

16

21.22547

Total

428.7829

19

of food waste moisture content measured was not effectual to result in a significant difference in the food waste moisture content collection of the four weeks.

3.3 Monitoring the Composting Process 3.3.1

Temperature

Temperature is considered to be one of the important factors during the composting process because it is related to the microbial activity during the degradation of organic material (Kumar et al. 2010). The variation in temperature as a function of time during the composting process is illustrated in Fig. 8. It was found that ambient temperature over 55 days of composting process is varied from 25 to 32 °C. In active zone compartment, there is no significant change for temperature at the bottom level indicating less microbial population. On the other hand, temperature at the top level of compartment was increased significantly until maximum temperature of 57 °C, possibly due to aerobic conditions. The maximum temperature would reach 57 °C because most of the fungal species dominated this area. The air circulation through the holes at the posterior wall of the reactor and regular turning of waste could have significantly increased the temperature of the composting pile. The temperature of the active zone compartment was in mesophilic range as the value is less than 45 °C until day-11. Subsequently, rapid increase in temperature to thermophilic range (>55 °C) was observed in top portion within 25 days of the composting. The temperature remains in this region for three days before gradually decrease. In contrast, the temperature in middle portions significantly decreased to ambient level in day-17. After six weeks, the temperature of the compost drop to ambient temperature. During composting process, if the temperature of the compost is more than 55 °C for 4 h or longer it is considered sufficient to kill many pathogens (Kreith and Tchobanoglous 2002). While temperature between 55 and 60 °C, most

Fig. 8 Temperature profile and weight of feedstock over 55 days of composting process

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Odour Scale

2.5 2 1.5 1 OT (1m)

0.5

OT (2m)

0

Date

Fig. 9 The intensity of odour at 1 m and 2 m distance from composter

parasites, weed seeds, human and plant pathogens (Salmonella sp. and Bacillus sp.) are expected to be destroyed.

3.3.2

Odour

During the composting process, characteristics of the raw materials are very important particularly food waste (Cerda et al. 2017), as it contributes to the odour generated during the composting process. The intensity of odour depends on the initial types of raw material that has been used for this composting process and optimum process condition. Odour could impact the environment. In worst case, it could cause to the plant closure and the implementation of prevention measures become necessary (Colón et al. 2012). Figure 9 shows the average data from odour test measured from the distance of one meter and two meter from the composting reactor. At the initial phase of composting process, the odour reaches scale 2 where the odour is very weak from one meter distance. For two meter distance, there is no odour of the compost detected. The results were continuously taken until the end of the composting process, and it was found that no odour was detected from one meter or two meter away from the composter. Usually, the source of odour coming from the VOC, where the very common emitted VOC families are terpenes, aliphatic carbon, aromatic hydrocarbons, ketones and esters (Zang et al. 2016). It was also reported that limonene is one of the most relevant VOCs (Komilis et al. 2004). However, in this study, the intensity of odour that has been produced from the composting material is very weak. Another aspects possibly contributes to these are the temperature and aeration rate that can affect the development of microbes during the composting process (Zang et al. 2016), where higher temperature could help the development of microorganism to enhance degradation of the composting material. Besides, good aeration rate could avoid anaerobic condition during degradation process, which subsequently reduces the production of odour. Interestingly, the odour produced from this composting process may not disturb the people surrounding the composter.

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3.4 Overall Mass Reduction The change in the volume of waste in all the compartments was monitored at regular intervals. At the initial phase of the composting process, the volume reduction was high due to the self-compaction of waste accompanied with the degradation of biodegradable organic matter (Manu et al. 2017). At the middle stage of the composting process, volume reduction of the compost material started to slow down, as the compost material becoming more compact. Turning process may result in rapid increase of temperature and at the same time could enhance the activity of the microorganism (Manu et al. 2017) thus facilitating the volume reduction. In terms of mass reduction, the residual mass after 55 days of composting process is 124.99 kg out of 232 kg, which is equivalent to 46.3% of mass reduction from the total weight of the feedstock. The mass reduction was reported to be proportional to the initial moisture content as most of the wet loss through evaporation of water and leaching. About 20–86% mass loss reported for food waste consisting of vegetables and fruits residues, with different bulking agents (Adhikari et al. 2009).

4 Conclusions Waste generation from FKJ cafeteria, UMS was successfully determined. About 680.2 kg of waste was generated in 4 weeks, with average 170 kg per week, and 33.9 kg per day. From this figure, a total food waste generation per week is around 127.7 kg, and average food waste generation per day is around 25.5 kg. Food waste is the major group of waste generated which is equivalent to 75% of total waste collected. The moisture content and density of the food waste were in the range of 75.0–77.5% and 2733–3877 kg/m3 , respectively. The food waste collected was combined with dry leaves and successfully used as feedstock for composting process over 55 days. The temperature and odour of the compost were carefully monitored during the process. The highest temperature achieved was 57 °C on day 25 of composting. The maximum intensity of the odour detected at 1 m distance from the composter is at scale 2 indicating that odour is very weak. In terms of mass reduction, the residual mass after 55 days of composting process is 124.99 kg out of 232 kg, which is equivalent to 46.3% of mass reduction from the total weight of the feedstock. Overall, food waste generated from FKJ cafeteria was successfully turned into compost in a locally fabricated composter with minimum emission of odour. The data on food waste generation and characteristics can be used as a basis for better food waste management in UMS.

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References Adhikari, B. K., Barrington, S., Martinez, J., & King, S. (2008). Characterization of food waste and bulking agents for composting. Waste Management, 28(5), 795–804. https://doi.org/10.1016/j. wasman.2007.08.018. Adhikari, B. K., Barrington, S., Martinez, J., & King, S. (2009). Effectiveness of three bulking agents for food waste composting. Waste Management, 29(1), 197–203. https://doi.org/10.1016/ j.wasman.2008.04.001. Aja, O. C., & Al-Kayiem, H. H. (2014). Review of municipal solid waste management options in Malaysia, with an emphasis on sustainable waste-to-energy options. Journal of Material Cycles and Waste Management, 16(4), 693–710. https://doi.org/10.1007/s10163-013-0220-z. Asis, T., Zahrim, A. Y., & Assis, K. (2017). Analisis prestasi proses pengkomposan sisa industri sawit dalam skala industri bagi jangka masa 3 tahun. Sains Malaysiana, 46(8), 1201–1210. Azril, A. (2017a). Introduction to ecocampus management centre. Retrieved September 11, 2018, from http://www.ums.edu.my/ecocampusv2/index.php/en/about-eco-campus/introduction-toeco-campus-management-centre. Azril, A. (2017b). Special Award for Green Campus Sustainability in 2017. Retrieved September 11, 2018, from http://www.ums.edu.my/ecocampusv2/index.php/en/news/114-special-awardfor-green-campus-sustainability-in-2017. Bernal, M. P., Alburquerque, J. A., & Moral, R. (2009). Composting of animal manures and chemical criteria for compost maturity assessment. A review. Bioresource technology, 100(22), 5444–5453. Budin, K., & Praveena, S. (2006). Waste audit and awareness level on recycling program: A case study in Universiti Malaysia Sabah (UMS), Malaysia. …, Sabah, Malaysia, 50–55. Retrieved from http://wwwsst.ums.edu.my/data/file/A4UVTr70Oz2f.pdf. Carry on Composting. (n.d.). Retrieved September 11, 2018, from http://www.carryoncomposting. com/416920216 Cerda, A., Artola, A., Font, X., Barrena, R., Gea, T., & Sánchez, A. (2017). Bioresource Technology Composting of food wastes: Status and challenges. https://doi.org/10.1016/j.biortech.2017.06. 133. Cerda, A., Artola, A., Font, X., Barrena, R., Gea, T., & Sánchez, A. (2018). Composting of food wastes: Status and challenges. Bioresource Technology, 248, 57–67. https://doi.org/10.1016/j. biortech.2017.06.133. Colón, J., Cadena, E., Pognani, M., Barrena, R., Sánchez, A., Font, X., et al. (2012). Determination of the energy and environmental burdens associated with the biological treatment of sourceseparated Municipal Solid Wastes. Energy & Environmental Science, 5(2), 5731–5741. https:// doi.org/10.1039/C2EE01085B. Fan, Y. Van, Lee, C. T., Leow, C. W., Chua, L. S., & Sarmidi, M. R. (2016). Physico-chemical and biological changes during co-composting of model kitchen waste, rice bran and dried leaves with different microbial inoculants. Malaysian Journal of Analytical Science, 20(6), 1447–1457. https://doi.org/10.17576/mjas-2016-2006-25. Iqbal, M. K., Shafiq, T., & Ahmed, K. (2010). Characterization of bulking agents and its effects on physical properties of compost. Bioresource Technology, 101(6), 1913–1919. https://doi.org/10. 1016/j.biortech.2009.10.030. Khoo, H. H., Lim, T. Z., & Tan, R. B. H. (2010). Food waste conversion options in Singapore: Environmental impacts based on an LCA perspective. Science of the Total Environment, 408(6), 1367–1373. https://doi.org/10.1016/j.scitotenv.2009.10.072. Komilis, D. P., Ham, R. K., & Park, J. K. (2004). Emission of volatile organic compounds during composting of municipal solid wastes. Water Research, 38(7), 1707–1714. https://doi.org/10. 1016/j.watres.2003.12.039. Kreith, F., & Tchobanoglous, G. (2002). Handbook of Solid Waste Management. Waste Management Research (Vol. 13). https://doi.org/10.1006/wmre.1995.0050. Kumar, M., Ou, Y. L., & Lin, J. G. (2010). Co-composting of green waste and food waste at low C/N ratio. Waste Management, 30(4), 602–609. https://doi.org/10.1016/j.wasman.2009.11.023.

Food Waste Composting at Faculty of Engineering …

191

Liang, C., Das, K. C., & McClendon, R. W. (2003). The influence of temperature and moisture contents regimes on the aerobic microbial activity of a biosolids composting blend. Bioresource Technology, 86(2), 131–137. https://doi.org/10.1016/S0960-8524(02)00153-0. Lim, W. J., Chin, N. L., Yusof, A. Y., Yahya, A., & Tee, T. P. (2016). Food waste handling in Malaysia and comparison with other Asian countries. International Food Research Journal, 23(December), S1–S6. Manu, M. K., Kumar, R., & Garg, A. (2017). Performance assessment of improved composting system for food waste with varying aeration and use of microbial inoculum. Bioresource Technology, 234, 167–177. https://doi.org/10.1016/j.biortech.2017.03.023. Paritosh, K., Kushwaha, S. K., Yadav, M., Pareek, N., Chawade, A., & Vivekanand, V. (2017). Food waste to energy: An overview of sustainable approaches for food waste management and nutrient recycling. BioMed Research International, 2017, 1–19. Rispo, A., Williams, I. D., & Shaw, P. J. (2015). Source segregation and food waste prevention activities in high-density households in a deprived urban area. Waste Management, 44, 15–27. https://doi.org/10.1016/j.wasman.2015.04.010. Thi, N. B. D., Kumar, G., & Lin, C. Y. (2015). An overview of food waste management in developing countries: Current status and future perspective. Journal of Environmental Management, 157, 220–229. https://doi.org/10.1016/j.jenvman.2015.04.022. Waqas, M., Nizami, A. S., Aburiazaiza, A. S., Barakat, M. A., Ismail, I. M. I., & Rashid, M. I. (2018). Optimization of food waste compost with the use of biochar. Journal of Environmental Management, 216, 70–81. https://doi.org/10.1016/j.jenvman.2017.06.015. Yaser, A. Z., Rahman, R. A., & Kali, M. S. (2007). Co-composting of palm oil mill sludge-sawdust. Pakistan Journal of Biological Sciences, 10(24), 4473–4478. Zang, B., Li, S., Michel, F., Li, G., Luo, Y., Zhang, D., et al. (2016). Effects of mix ratio, moisture content and aeration rate on sulfur odor emissions during pig manure composting. Waste Management, 56, 498–505. https://doi.org/10.1016/j.wasman.2016.06.026. Zahrim, A. Y., Leong, P. S. Ayisah, S. R., Janaun, J., Chong, K. P., Cooke, F. M., Haywood, S. K. (2016). Composting paper and grass clippings with anaerobically treated palm oil mill effluent. International Journal of Recycling of Organic Waste in Agriculture, 5(3), 221–230. Zen, I. S., Subramaniam, D., Sulaiman, H., Saleh, A. L., Omar, W., & Salim, M. R. (2016). Institutionalize waste minimization governance towards campus sustainability: A case study of Green Office initiatives in Universiti Teknologi Malaysia. Journal of Cleaner Production, 135, 1407–1422. https://doi.org/10.1016/j.jclepro.2016.07.053. Zhang, L., & Sun, X. (2018). Influence of sugar beet pulp and paper waste as bulking agents on physical, chemical, and microbial properties during green waste composting. Bioresource Technology, 267, 182–191. https://doi.org/10.1016/j.biortech.2018.07.040.

Characterization of University Residential and Canteen Solid Waste for Composting and Vermicomposting Development Nurmin Bolong and Ismail Saad

Abstract Composting involves the biological decomposition of materials (solid or semi-solid) using microorganisms over a period of time, resulting in organic material degradation and volume reduction. The composting process has always been a part of natural ecosystems and four basic components: organic matter, moisture, oxygen, and bacteria. However, failure to understand the complexity of biological, chemical, and physical processes can hinder a composting system. Furthermore, inadequate optimization of modern composting in urban waste streams can lead to excessive waste in open dumps and landfills. In this study, solid waste taken from four residential sources and one commercial source (canteen) at Universiti Malaysia Sabah (UMS) was characterized. The main component (87%) of this waste was found to be organic or food refuse. Composting experiments on this waste were conducted using a laboratory-scale custom-made setup under five different conditions, and their compost products were quantitatively analyzed. Vermicomposting produced compost with better NPK content than an open composting system. All compost products were found to have pH values between 6 and 7.5, making them suitable for plant growth. Electrical conductivity (EC) was observed to be lower than that required for plant growth (