Environmental Technology and Sustainability: Physical, Chemical and Biological Technologies for Clean Environmental Management 0128191031, 9780128191033

Table of contents :
Cover
Title
Front-matter
Environmental Technology and Sustainability
Environmental Technology and Sustainability
Copyright_2020_Environmental-Technology-and-Sustainability
Copyright
Contents_2020_Environmental-Technology-and-Sustainability
Contents
1
1 Conceptual development for a clean environment
Abbreviation
1.1 Introduction
1.1.1 From the Rio Earth Summit to Earth Day
1.1.1.1 Conceptual development of summit
1.1.1.1.1 Convention on Biological Diversity
1.1.1.2 Framework Convention on Climate Changes
1.1.1.2.1 United Nations Convention to Combat Desertification
1.1.2 Earth Day
1.1.3 Data generation, compiling, and application for environmental studies
1.1.3.1 Filling the environmental policy gaps
1.1.3.2 Filling the gap in improving air quality development
1.1.3.3 Filling the gaps in monitoring marine pollution
1.1.3.4 Filling the gaps in restoration of biodiversity
1.1.4 Developing a binding framework of environmental principles
1.1.4.1 Environmental governance tools
1.1.5 Global climate change regime
1.1.6 Imposing liability for environmental damage
1.1.6.1 Types of liability for environmental damage
1.1.6.1.1 Fault liability
1.1.6.1.2 Absolute liability
1.1.7 The laws of environmental liability
1.1.8 Environmental restoration and remediation
1.1.8.1 Environmental restoration
1.1.8.2 Ecological restoration
1.1.9 Environmental remediation
1.1.9.1 Tools and techniques used in environmental remediation
1.1.9.1.1 Soil remediation types and techniques
1.1.9.1.2 Contaminated water remediation
1.1.9.1.3 Conventional raw water treatment
1.1.10 Environmental management and green economy
1.1.10.1 Pillars for green economy success
1.1.10.2 Green Economy Index
1.1.10.3 Green energy for green economy
References
2
2 Greenhouse gas capture and conversion
2.1 Greenhouse gases and global warming
2.1.1 History
2.1.2 Sources of greenhouse gases
2.1.2.1 Transport systems
2.1.2.2 Electricity production as a source of greenhouse gas
2.1.2.3 Dairy farming as a source of greenhouse gas
2.1.3 Carbon capture, utilization, and storage
2.1.3.1 Carbon sequestration process
2.1.3.1.1 Biological process
Azolla filiculoides as carbon capture biological system
Marine algae as a source of alternate fuel
Agriculture
Forestry residues
2.1.3.1.2 Chemical technology for carbon capture
Methods for carbon-neutral fuel
Synthetic hydrocarbon from flue gas
2.1.4 Commercialization of carbon capturing process
2.1.5 Greenhouse gas separation
2.1.5.1 Carbon dioxide separation methods
2.1.5.1.1 Absorption
Nature of solvent
Adsorption
2.1.5.1.2 Physical adsorption
2.1.6 Different cycle for CO2 adsorption
2.1.6.1 Cryogenic distillation
2.1.6.2 Membrane separation
2.1.6.2.1 Inorganic membrane
2.1.6.3 Polymeric membrane
2.1.6.4 Mixed matrix membrane
2.1.6.5 Hollow fiber membrane
References
3
3 Aqueous-phase conservation and management
3.1 Water coverage Earth’s surface
3.1.1 Rivers, lakes, and brackish systems
3.1.2 Marine systems
3.1.3 Water quality control
3.1.3.1 Brine treatment
3.1.3.2 Solid removal technology
3.1.3.3 Removal of oil spills and grease from contaminated water
3.1.3.3.1 How oil spills interact with waterbodies
3.1.3.3.2 Damage caused by oil spills
3.1.3.3.3 Bacteria and archaea for oil spill remediation
3.1.3.3.4 Hydrocarbon-degrading fungi
Oil spill degrading algae and cyanobacteria
3.1.3.3.5 Mechanisms of oil spill bioremediation
3.1.3.4 Sewage wastewater treatment
3.1.3.4.1 Primary treatment
3.1.3.4.2 Secondary treatment of sewage water
3.1.3.4.3 Tertiary treatment
3.1.3.5 Removal of biodegradable organic wastes
3.1.3.6 Removal of other organic materials from wastewater
3.1.4 Water pollution control regulation
3.1.5 Sustainable energy management from waterbodies
3.1.5.1 Microbial fuel cell technology for energy from wastewater
3.1.5.2 Microbiology of fuel cells
3.1.5.2.1 Types of microbes in microbial fuel cells
3.1.5.2.2 Bacterial metabolism and electron transfer in microbial fuel cells
3.1.5.2.3 Factors affecting electricity generation
3.1.5.2.4 Power generation in microbial fuel cells
3.1.5.2.5 Types of microbial fuel cells
Double-chamber microbial fuel cells
Single-chamber microbial fuel cells
Up flow–style microbial fuel cells
Stacked microbial fuel cell
The plant microbial fuel cell
Tubular microbial fuel cell
3.1.5.3 Components of a microbial fuel cell
3.1.5.3.1 Anode
3.1.5.3.2 Cathode
3.1.5.3.3 Proton exchange membrane
3.1.6 Applications of microbial fuel cell technology
3.1.6.1 Wastewater treatment
3.1.6.2 Microbial fuel cell for landfill
3.1.6.3 Generation of electricity directly from plants
3.1.6.4 Biological oxygen demand sensing
3.1.7 Hydrogen production
3.1.8 Marine microalgae for carbon sequestration or sink
3.2 Conclusion
References
4
4 Strategies for soil management
4.1 Major soil pollutants
4.1.1 Manmade
4.1.2 Natural causes of soil pollutants
4.2 Soil quality management
4.2.1 Moisture
4.2.2 Enhance organic matter
4.2.3 Avoid excessive tillage
4.2.4 Manage pests and nutrients efficiency
4.2.5 Prevent soil compaction
4.2.6 Coverage of ground
4.2.7 Diversity management by multiple cropping
4.3 Control of soil pollution
4.3.1 Nanoremediation for contaminated soil
4.3.2 Immobilization techniques
4.3.2.1 Solidification
4.3.2.2 In situ vitrification for soil remediation
4.3.2.2.1 In situ vitrification
4.3.2.2.2 Ex situ vitrification
4.3.3 Soil washing
4.4 Regulatory aspects of soil pollution control
4.4.1 International law for soil protection
4.4.2 European law
4.4.3 National law
4.4.4 Building law and regional planning law
4.4.5 Close Cycle Management Act
4.4.6 Nature conservation law
References
5
5 Air pollution and controlling measures
5.1 Atmosphere as a primary sink of air pollutants
5.1.1 The troposphere
5.1.2 The stratosphere
5.1.3 Mesosphere
5.1.4 The thermosphere
5.2 Air pollutants
5.2.1 Types of air pollutants
5.2.2 Suspended particulate matter
5.2.3 Gaseous pollutants
5.2.3.1 China
5.2.3.2 United States
5.2.3.3 India
5.2.3.4 Sulfur oxide
5.2.3.5 Nitrogen oxides
5.2.3.6 Carbon monoxide
5.2.3.7 Volatile organic compounds
5.2.3.8 Fluoride
5.2.3.9 Chlorine
5.2.3.10 Hydrogen chloride
5.2.3.11 Ammonia
5.2.4 Secondary pollutants
5.2.5 Odors
5.3 Clean air implementation
5.3.1 Particulate matter
5.3.1.1 Ozone
5.3.1.2 Nitrogen dioxide
5.3.1.3 Sulfur dioxide
5.4 Regulation of air pollution
5.4.1 European Union
5.4.2 Australia
5.4.3 Brazil
5.4.4 Canada
5.4.5 China
5.4.6 India
5.4.7 France
5.4.8 United States
5.4.9 Israel
5.4.10 Japan
5.4.11 South Africa
5.4.12 Switzerland
5.4.13 The United Kingdom
5.5 Air pollution control measures
5.5.1 Control of particulates
5.5.1.1 Wet industrial scrubber
5.5.1.2 Dry industrial scrubber
5.5.1.3 Electrostatic precipitators
5.5.2 Biological treatment of air pollution
5.5.2.1 Trickling-filter scrubbers
References
Index
Index
Back Cover

Citation preview

Environmental Technology and Sustainability Physical, Chemical, and Biological Technologies for Clean Environmental Management

Environmental Technology and Sustainability Physical, Chemical, and Biological Technologies for Clean Environmental Management

Basanta Kumara Behera Advanced Center for Biotechnology; Maharshi Dayanand University, Rohtak, Haryana, India, Sanmar Speciality Chemical Ltd, India

Ram Prasad Department of Botany Mahatma Gandhi Central University, Motihari, Bihar, India

Elsevier Radarweg 29, PO Box 211, 1000 AE Amsterdam, Netherlands The Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, United Kingdom 50 Hampshire Street, 5th Floor, Cambridge, MA 02139, United States Copyright © 2020 Elsevier Inc. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangements with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions. This book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein). Notices Knowledge and best practice in this field are constantly changing. As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treatment may become necessary. Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds, or experiments described herein. In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility. To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors, assume any liability for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein. British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library Library of Congress Cataloging-in-Publication Data A catalog record for this book is available from the Library of Congress ISBN: 978-0-12-819103-3 For Information on all Elsevier publications visit our website at https://www.elsevier.com/books-and-journals

Publisher: Susan Dennis Acquisitions Editor: Kostas KI Marinakis Editorial Project Manager: Sara Valentino Production Project Manager: Bharatwaj Varatharajan Cover Designer: Victoria Pearson Typeset by MPS Limited, Chennai, India

Contents CHAPTER 1 Conceptual development for a clean environment...... 1 Abbreviation .................................................................................. 1 1.1 Introduction ....................................................................................2 1.1.1 From the Rio Earth Summit to Earth Day ....................... 3 1.1.2 Earth Day .......................................................................... 5 1.1.3 Data generation, compiling, and application for environmental studies ....................................................... 6 1.1.4 Developing a binding framework of environmental principles ......................................................................... 11 1.1.5 Global climate change regime ........................................ 14 1.1.6 Imposing liability for environmental damage ................ 15 1.1.7 The laws of environmental liability ............................... 18 1.1.8 Environmental restoration and remediation ................... 20 1.1.9 Environmental remediation............................................. 23 1.1.10 Environmental management and green economy .......... 35 References.................................................................................... 37

CHAPTER 2 Greenhouse gas capture and conversion .................. 41 2.1 Greenhouse gases and global warming .......................................41 2.1.1 History ............................................................................... 41 2.1.2 Sources of greenhouse gases ............................................ 43 2.1.3 Carbon capture, utilization, and storage........................... 44 2.1.4 Commercialization of carbon capturing process.............. 52 2.1.5 Greenhouse gas separation................................................ 55 2.1.6 Different cycle for CO2 adsorption .................................. 62 References.................................................................................... 65

CHAPTER 3 Aqueous-phase conservation and management ........ 73 3.1 Water coverage Earth’s surface ...................................................73 3.1.1 Rivers, lakes, and brackish systems ................................. 73 3.1.2 Marine systems ................................................................. 74 3.1.3 Water quality control ........................................................ 79 3.1.4 Water pollution control regulation ................................... 96 3.1.5 Sustainable energy management from waterbodies ......... 96 3.1.6 Applications of microbial fuel cell technology.............. 119 3.1.7 Hydrogen production ...................................................... 123

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3.1.8 Marine microalgae for carbon sequestration or sink...... 123 3.2 Conclusion ..................................................................................127 References.................................................................................. 130

CHAPTER 4 Strategies for soil management ............................... 143 4.1 Major soil pollutants ..................................................................146 4.1.1 Manmade ......................................................................... 146 4.1.2 Natural causes of soil pollutants..................................... 151 4.2 Soil quality management............................................................152 4.2.1 Moisture .......................................................................... 152 4.2.2 Enhance organic matter .................................................. 153 4.2.3 Avoid excessive tillage ................................................... 153 4.2.4 Manage pests and nutrients efficiency ........................... 153 4.2.5 Prevent soil compaction.................................................. 154 4.2.6 Coverage of ground ........................................................ 154 4.2.7 Diversity management by multiple cropping ................. 155 4.3 Control of soil pollution.............................................................156 4.3.1 Nanoremediation for contaminated soil ......................... 158 4.3.2 Immobilization techniques.............................................. 158 4.3.3 Soil washing .................................................................... 161 4.4 Regulatory aspects of soil pollution control..............................162 4.4.1 International law for soil protection ............................... 162 4.4.2 European law................................................................... 163 4.4.3 National law .................................................................... 164 4.4.4 Building law and regional planning law ........................ 164 4.4.5 Close Cycle Management Act ........................................ 164 4.4.6 Nature conservation law ................................................. 164 References.................................................................................. 165

CHAPTER 5 Air pollution and controlling measures ................... 169 5.1 Atmosphere as a primary sink of air pollutants ........................170 5.1.1 The troposphere............................................................... 170 5.1.2 The stratosphere .............................................................. 170 5.1.3 Mesosphere...................................................................... 172 5.1.4 The thermosphere............................................................ 172 5.2 Air pollutants..............................................................................172 5.2.1 Types of air pollutants .................................................... 172 5.2.2 Suspended particulate matter.......................................... 172 5.2.3 Gaseous pollutants .......................................................... 173 5.2.4 Secondary pollutants ....................................................... 177 5.2.5 Odors ............................................................................... 177

Contents

5.3 Clean air implementation ...........................................................180 5.3.1 Particulate matter ............................................................ 181 5.4 Regulation of air pollution.........................................................183 5.4.1 European Union ............................................................ 183 5.4.2 Australia ........................................................................ 185 5.4.3 Brazil ............................................................................. 185 5.4.4 Canada........................................................................... 186 5.4.5 China ............................................................................. 187 5.4.6 India............................................................................... 188 5.4.7 France ............................................................................ 189 5.4.8 United States ................................................................. 189 5.4.9 Israel .............................................................................. 190 5.4.10 Japan.............................................................................. 190 5.4.11 South Africa .................................................................. 191 5.4.12 Switzerland.................................................................... 191 5.4.13 The United Kingdom .................................................... 192 5.5 Air pollution control measures ..................................................192 5.5.1 Control of particulates .................................................... 192 5.5.2 Biological treatment of air pollution .............................. 195 References.................................................................................. 198 Index ......................................................................................................................201

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Chapter Outline Abbreviation ............................................................................................................... 1 1.1 Introduction ......................................................................................................... 2 1.1.1 From the Rio Earth Summit to Earth Day ............................................3 1.1.2 Earth Day ........................................................................................5 1.1.3 Data generation, compiling, and application for environmental studies ............................................................................................6 1.1.4 Developing a binding framework of environmental principles ..............11 1.1.5 Global climate change regime..........................................................14 1.1.6 Imposing liability for environmental damage .....................................15 1.1.7 The laws of environmental liability ...................................................18 1.1.8 Environmental restoration and remediation .......................................20 1.1.9 Environmental remediation..............................................................23 1.1.10 Environmental management and green economy ...............................35 References ............................................................................................................... 37

Abbreviation ABS Access and Benefit-sharing BIEN Botanical Information Network and Ecology Network GBIF Global Biodiversity Information Faculty CBD Convention on Biological Diversity COP Conference of the Parties EI environment information EPA Environmental Protection Agency EQI Environmental Quality Index EEZ exclusive economic zone EU European Union FAO Food and Agriculture Organization GBIF Global Biodiversity Information Faculty GGEI Global Green Economy Index IT information technology IOOS Integrated Ocean Observing System IEL International Environmental Law ILC International Law Commission Environmental Technology and Sustainability. DOI: https://doi.org/10.1016/B978-0-12-819103-3.00001-9 © 2020 Elsevier Inc. All rights reserved.

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IAEA International Atomic Energy Agency IMO International Maritime Organization ILO International Labor Organization ISB in situ bioremediation ICC International Chamber of Commerce LMO living modified organism LDN land degradation neutrality LIDAR light detection and ranging LMIC low and middle income MBI market-based instruments NCDS National Consortium for Data Science NOAA National Oceanic Atmospheric Administration NOS National Ocean Service OSRTI Office of Superfund Remediation and Technology Innovation SDG Sustainable Development Goal SER Society for Ecological Restoration UNCED United Nations Conference on Environment and Development UNEP United Nations Environmental Program UNCCD United Nations Convention to Combat Desertification UNEP United Nations Environment Program UNFCCC United Nations Framework Convention on Climate Change UNESCO United Nations Education, Scientific and Culture Organization WCED World Commission on Environmental and Development WHO World Health Organization

1.1 Introduction Over the past few decades, protecting the global environment has emerged as one of the major challenges in international relations. Global environmental treaties have been putting great effort into promoting cooperation by means of systematic observations, research, and information exchange on the effects of human activities on the ozone layer and to adopt legislative or administrative measures against activities likely to have adverse effects on the ozone layer. In-spite of hundred of regional and bilateral agreement still there is no substantial change in the declination global environmental problem. Virtually every major environmental indicator is worse today than it was at the time of the 1992 United Nations Conference on Environment and Development (UNCED or the Earth Summit) held in Rio de Janeiro. Climate change has caused the warmest decade in recorded history, the ozone layer continues to deteriorate, species extinction is at its highest since the end of the dinosaur era, fish populations are crashing, and toxic chemicals are accumulating in every part of the planet as well as in every living organism including humans. So, it is necessary to give liberty to international institutions and non-government organisations to express citizen’s right to information, participation and independent review on alarming condition of environment around the

1.1 Introduction

world. Unfortunately, no protocol and standard procedures are available to use at government level to implement resolutions for international bodies for the protection of Earth from notorious greenhouse gases responsible for the depletion of the ozone layer, and protective majors for monitoring the global climatic changes scenario. In addition, special emphasis should be placed on short-term energy security and long-term energy conservation processes in a sustainable pattern. It is also necessary that each and every nation should honor the decisions of international bodies, aiming for a clean environment for a better life.

1.1.1 From the Rio Earth Summit to Earth Day In June 1992, for the first time in world history, 500 heads of state met in Rio de Janeiro, Brazil for an international Earth summit, the “United Nations Conference on Environment and Development (UNCED).” It also carries the informal name, “Earth Summit.” The conference took place from June 3 to June 14. The main motivation of the summit was to protect the environment and the relationship between economics, science, and the environment based on the prevailing political scenario at the global level on a priority basis.

1.1.1.1 Conceptual development of summit In 1968, the United Nations (UN) General Assembly called for an international conference to understand “problem of the human environment and also to identify those aspects of it that can only, or best be solved through international cooperation and agreement.” The original proposal was initiated by Sweden [1]. In between 1970 to 1972, the Canadian foreign aid agency had organized four international conferences to focus various issues on environmental problems in collaboration with developing countries. The first initiation in developing awareness about environmental deterioration was held in 1972, Stockholm, Sweden. This first initiation, the United Nations Conference on the Human Environment, was organized to raise awareness and also to take necessary steps for monitoring the environment changes caused due to unusual human activities. This summit was attended by 114 delegates and 2 heads of state (Olaf Palme of Sweden and Indira Gandhi of India). The Stockholm conference secured a permanent place for the environment on the world’s agenda and led to the establishment of the United Nations Environment Program (UNEP). This world conference was followed by many international meetings which include the 1978 Great Lakes Water Quality Agreement, the 1979 Geneva Convention on Long-range Transboundary Air Pollution, the 1985 Helsinki Agreement, and the 1988 Montreal Protocol on Transboundary Movement of Hazardous Wastes. Being inspired by these international conferences, in 1992, the Rio Conference was initiated on a global level with a wider range of nations. In 1983, under the leadership of Norwegian Prime Minister from Harlem, the UN General Assembly set up the World Commission on Environment

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Development (known as the Brundtland Commission) to link environmental issues to the findings of the 1980 Brandt report on North South relations. But it took about 7 years (1987) for the publication of the report. The report was mainly based on the environment and economy in order to bring about sustainability in development [2]. The Earth Summit in Rio de Janeiro was exceptionally unique due to the marvelous gathering of thousands of representatives from all around the globe. This conference persuaded all state levels to rethink environmental protection and economic development and find ways to halt the deformation of global ecosystems and the pollution of the planet. It was a huge gathering of about 30,000 delegates including media people and the representatives of 178 nations. The main target of this conference was to bring sustainability in environmental management process development [3]. The concluding session of the Earth Summit resulted in three major action agendas: 1. The Rio Declaration on Environment and Development: The Rio Declaration had 27 major actions to guide countries in future sustainable development. It was signed by over 170 countries [4]. 2. Agenda 21: The “21” in Agenda 21 refers to the 21st century. Agenda 21 is a nonbinding action plan of the UN to bring sustainability into environmental development projects [5,6]. The agenda mainly includes initiating the various aspects of Agenda 21 at local state government level through their respective local agendas on various issues related to environment conservation and sustainability. 3. Forest Principles: The Forest Principles (Rio Forest Principles) are mainly concerned with “Non-Legally Binding Authoritative Statement of Principles for a Global Consensus on the Management, Conservation, and Sustainable Development of All Types of Forest (1992).” This informal document was produced at UNCED. In the Earth Summit (1992), there were several legally binding agreements open for signature.

1.1.1.1.1 Convention on Biological Diversity The Convention on Biological Diversity (CBD) is a multilateral treaty having three major goals including (1) the conservation of biological diversity (biodiversity), (2) the sustainable use of its components, and (3) the equitable sharing of benefits arising from genetic resources. In brief, the basic objective is to frame policies at government level on strategies for the conservation and sustainable use of biological diversity. The convention was opened for signature at the Earth Summit in Rio de Janeiro on June 5, 1992, and was implemented on December 29, 1993. The CBD has two

1.1 Introduction

supplementary agreements. (1) The Cartagena Protocol on Biosafety to the Convention on Biological Diversity. It is on international treaty governing the movements of living modified organisms (LMOs) due to transfer of biotechnology from one country to another. In 1993, it was introduced as a supplementary agreement to the CBD on January 29th, and was implemented on September 11th. (2) The Nagoya Protocol on Access to Genetic Resources and Fair and Equitable Sharing of Benefits Arising from their Utilization (ABS). The Nagoya Protocol on ABS was adapted on October 29, 2010, in Nagoya, Japan, and entered into use on October 12, 2014. It is aimed at the fair and equitable sharing of benefits arising from the utilization of genetic resources.

1.1.1.2 Framework Convention on Climate Changes The international environmental treaty on climatic changes was adapted by the United Nations Framework Convention on Climate Change (UNFCCC) on May 9, 1992 and was introduced at the Earth Summit in Rio de Janeiro for signature. It then entered into use on March 21, 1994, after the rectification by many participating counties. Its main aim was to bring stability to greenhouse gas emissions to prevent hazardous anthropogenic interference with the climatic system [7].

1.1.1.2.1 United Nations Convention to Combat Desertification In 1994, the United Nations Convention to Combat Desertification (UNCCD) made an international agreement linking the environment and development to sustainable land management. It was mainly targeted at arid, semi-arid, and dry subhumid areas to bring about amendment to stop desertification or detritions. The UNCCD framework is to achieve land degradation neutrality (LDN) in order to restore productivity to the huge amount of degraded land at a global level by 2030.

1.1.2 Earth Day In 1968, Morton Hilbert and the US Public Health Service organized the Human Ecology Symposium with the basic theme focusing on environment degradation. Hearing from scientists, the student community got inspired to find ways and means of spreading awareness about environment degradation [8]. In reality, this was the beginning of Earth Day. For two subsequent years, Hilbert and students were deeply involved in planning strategies for the first Earth Day [9]. Meanwhile, in 1969, peace activist John McConnell proposed a day to honor the Earth in order to acquire global peace at the UN Education, Scientific, and Culture Organization (UNESCO) Conference in San Francisco. His desire was to celebrate this occasion on March 21, 1970, the onset of spring in the northern hemisphere. This was later sanctioned by Secretary General U Thant of the UN. A month later Senator Gaylord Nelson from Wisconsin proposed for Earth Day, after witnessing a hazardous and massive oil spill in Santa Barbara, California [10]. In the same year, on November 15, the Vietnam Moratorium Committee

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staged a huge protest against the Vietnam War. This was attended by half a million people in peaceful demonstration in Washington. In order to divert the students’ minds Senator Nelson announced the idea for a “national teach-in on environment” to the national media and public. On April 22, 1970, about 20 million Americans raised their voices against the deterioration of environmental quality due to oil spills, the influx of industrial effluents into the various ecosystems, raw sewage, toxic dumps, pesticides, the emission of greenhouse gases, and the extinction of biodiversity. This agitation received support from every corner of the nation. Since then, April 22 is a day to promote and bring environment awareness for the conservation of the planet. It is celebrated in more than 193 countries each year, and is coordinated by the nonprofit Earth Day Network, chaired by the first Earth Day (1970) organizer Denis Hayes. It is the largest secular holiday in the world, and is celebrated by more than a billion people every year, in an attempt to make governments aware of all the stats to frame and to implement effective policies for global environment safety and security [11,12]. 2017 also witnessed the Earth Day celebration with the March for Science rally at the National Mall in Washington, DC. In 2019, a huge campaign was organized jointly by Earth Network and Keep America Beautiful as National Cleanup Day for the inaugural nationwide Earth Day cleanup. This campaign was held in all 50 States with more than 500,000 volunteers [13].

1.1.3 Data generation, compiling, and application for environmental studies Both inanimate and animate systems are being managed for sustainability on the basis of data compiling and assessment processes based on their geographical location, physicochemical characters, climatic changes, and overall interaction with human activities. Human activities include industrialization, urbanization, rural structure and function, and socioeconomic conditions. Our present way of life is mainly regulated by the data-driven age. The structure and function of life is mainly dependent on the surrounding environment. Thus cumulative data on environmental science can be integrated and correlated with the structure and function of life. Information technology (IT) is used as a data compiling tool for surveying environment information on ecosystems, biodiversity, resource conservation, climatic changes, health hazardous factors, healthcare, toxicological aspects, wastes types and generation sources, nonconventional energy, etc. These data can be helpful in research and development, regulatory processes, framing of policy, and environment management (Table 1.1).

1.1.3.1 Filling the environmental policy gaps One of the best examples of a database information system is the US Environmental Protection Agency (US EPA). The US EPA is an independent

1.1 Introduction

Table 1.1 Nature of data mining for filling gaps of various aspects of environmental restoration and development. Nature of data mining

Implementation

Filling the environmental policy gaps Filling the gap in improving air quality development

Environmental protection, research, conservation, monitoring, bring sustainability To cover wide spectrum of air quality analysis by using satellite and ground-level monitoring ways and means, and provide technical information in finding out solution for air quality improvement. Restoration of marine ecosystem from climatic changes and unusual human activity Developing integrated network program for data collection, so that data can be used together and more accessible to users Biodiversity data are displayed on public domain so that scientists and public can have overall information on taxonomy, geographical distribution, and structure and function of organisms

Filling the gaps to monitor marine pollution

Filling the gaps—restoration of biodiversity

body of the United States federal government for environmental protection. Besides environment research and education, the agency has data mines having vast and updated information on environmental laws (in consultation with state, tribal bodies, and local government), information on the toxicity of thousands of chemicals present in the environment, and technical information related to environment conservation. The main target of such data mining is to feed information to scientists and the public for taking action and keeping the planet a lively and habitable world. In collaboration with the National Consortium for Data Science (NCDS), the US EPA gives technical support for data science research and identifies data science challenges. Some of the important projects undertaken by the US EPA to compile and use on the basis of requirement are: 1. The Stream-Catchment (StreamCat) This provides extensive landscape metrics for about 2.65 million streams and their associated catchment in United States has been available for public use for research and management. The StreamCat dataset provides an important tool for stream researchers and managers to understand and characterize the nation’s rivers and streams. 2. EnvironAtlas This data information is an interactive tool and explains a wide range of information on “ecosystem goods and services” covering the continent of the United States, and some data on select communities. 3. The Web-based Interspecies Correlation Estimation (Web-ICE)

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This is a user-friendly internet facility to provide information on the acute toxicity of multiple species within an ecosystem for accessing the risk to individuals and communities. 4. The Environmental Quality Index (EQI) Based on air, water, land, built environment, and sociodemographic space, the EQI is an index of environmental quality prepared for 50 states at the country level. This EQI tool acts as a guideline to study the impact of an environment on specific health outcomes.

1.1.3.2 Filling the gap in improving air quality development The World Bank has taken the initiative, in collaboration with the US EPA, to improve the measurement of air quality in low- and middle-income countries (LMIC). The main target is to find future strategies to cover a wide spectrum of air quality analyses using satellite and ground-level monitoring means, and to provide technical information toward finding a solution for air quality improvement. The meeting resulted in the drafting of a white paper aiming to provide preliminary guidance to LMIC for practicing the framing of protocol on air quality and policy design at government level. The US EPA is also involved in developing and improving instruments, air sensors, techniques, and other tools to monitor air pollution and to protect the planet from hazardous greenhouse gases due to uncontrolled human activity. In order to regulate National Ambient Air Quality Standards and framing policy and mitigation strategies to protect air quality, it is necessary to have integrated and cumulated data analyses mining on the dynamic status of the environment with reference to climatic changes. The US EPA improves environmental research quality by providing updated data on air quality profiles in industrialized areas, oil and gas production facilities, and coal-fired power plants; monitoring to safeguard public health. The advanced technology developed by the US EPA in association with other research and development sectors help the United States to assist communities and tribes in air quality management programs. The US EPA is also taking care of advanced air quality instruments (including portable-type instruments) for the National Ambient Air Quality Standards to provide mobile and stationary real-time measurement capabilities that can be used as a conventional tool for measuring air quality around industrial localities, oil gas operation areas, rail yards, or ports. The primary purpose for providing an air quality monitoring network for the public domain is to have comparative information from a given area contaminated with air pollutants and that of the ambient air quality standard, and to create awareness among the public so they remain concerned about their health. The health-based ambient air quality standard is set on the basis of ambient air quality for a specific area as per public need. So, in order to monitor air quality, IT, regulation, and data compiling strategies are absolutely necessary. In addition, data collection and compiling are essential to ensure progress toward attaining the ambient air quality standard or to show that the standard has been achieved.

1.1 Introduction

Success in reducing regional air pollution intensity is mainly dependent on the use of systematic monitoring network programs. A monitoring network represents various geographical areas such as coastal areas, desert areas, interior valleys, mountain areas, and border areas. In addition, having a wide range of diversified sectors, irrespective of their structures at the microscale, middle scale, neighborhood scale, urban scale, or regional scale is an important consideration. The purpose of filling gaps in air quality data is to close the extensive air quality monitoring data gaps and empower developing countries and to instruct governments to frame and implement policies for improving air quality.

1.1.3.3 Filling the gaps in monitoring marine pollution Currently, international institutes with competence in environment management have shown keen involvement in organizing programs to guide the conservation, protection, and sustainable management of marine ecosystems. But only 4.8% of the world’s ocean areas are protected in implemented and actively managed marine protected areas (MPAs) [14,15]. About 2.2% of ocean area is under protection as “highly protected marine reserves.” Under the CBD, the UN’s target for global ocean protection is for 10% of the coastal and marine areas to be MPAs by 2020. But according to UN Sustainable Development Goal 14 (SDG 14) the goal of meeting the 10% global target by 2020 is not currently on track. However, it has also been reported that some countries will meet the 10% target for areas within their exclusive economic zones [16]. Still, marine ecosystems are in an alarming condition due to the lack of adequate data mining on the inputs and quantities of pollutants and their harmful effects on marine ecosystems. In order to keep coastal communities safe and sound, it is necessary to improve economies, and marine ecosystems require monitoring of ocean and coastal areas, and monitoring and assessing of how these areas are changing with time. So, it is necessary to have a data bank on seawater contamination, assessing environmental changes in coastal areas, monitoring sealevel rise, surveying coastlines and coastal sea floors, and chemical and biological observations that would be helpful for coastal communities to make the best decision for themselves. Currently, a variety of tools and techniques such as satellites, thermometers, and tide gauges are in use to obtain data on marine ecosystems. But all collected observations are not in the same format, and cannot be easily compiled and interpreted for a specific purpose. It seems certain lacuna is left to bridge the data interpretation on the functional aspects of marine system on the basis of geographical location and climatic changes. In order to fill the observed gaps, the US Integrated Ocean Observing System (IOOS) led by the National Oceanic Atmospheric Administration (NOAA) developed an integrated network program for data collection so that data can be used together and be more accessible to users. In addition, data on erosion and other forces responsible for changing coastal landscapes can be developed by light detection and ranging (or LIDAR) technology, presently being used by the National Ocean Service (NOS). Satellite imagery

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and aerial photography tools are used to survey and create maps of shoreline and land cover changes over time. Data on rises in sea level and other flood-related hazards is important for coastal communities to be safe and sound during adverse climatic changes around coastal areas. For such information, NOS helps coastal communities whenever affected by adverse climatic changes. Such types of practices can be extended to other parts of the world in coastal habitants when risks to survival arise due to adverse climatic changes. The place where a river meets with a sea is known as an estuary, and estuaries serve as favorable habitats for life. Due to their critical locations, they are necessary to feed local peoples depending on the physicochemical status of brackish estuaries at the time of adverse climatic changes. However, there are also several freshwater estuaries similar to brackish estuaries that provide compactable life systems of many species of birds, fishes, and other animals. Estuaries are the most productive type ecosystem in the world. National ocean service with the partnership of 28 state managed National Est urine Research Reserves developed mobile research laboratories to manage update data network in public domain. As part of this program, scientists collect data on factors such as temperature, salinity, pH, biodiversity, and population characteristics at reserves across the United States. In addition, data on the status and profiles of a wide range of marine life such as coral, fish, clams, marine weeds, and bacteria play important roles in ecosystem stability, ocean food chains, and helping to filter pollutants out of the water. In order to keep updated information on such oceanic flora and fauna, NOS uses satellite and airborne sensors, acoustic imaging, photography, and benthic community analyses. Aerial photographs are also used to create maps of coral reefs and other habitats. Surveys relating to the Coastal and Marine Ecological Classification Standard provide unique data banking systems on habitats on both a local and regional basis.

1.1.3.4 Filling the gaps in restoration of biodiversity Biodiversity represents the total variety of life on the planet, which includes the total number of races and species diversification. Tropical rain forests and coral reefs are rich in biodiversity. Of the entire world’s species, only 10% 15% live in North America and Europe. The Malaysian Peninsula, for example, has at least 8000 species of flowering plants, while Britain, with an area twice as large, has only 1400 species. In South America, about 2,000,000 species of plants are available. Areas isolated by water, desert, or mountains can also have a wide range of unique species and biodiversity. Unusual numbers of diversified species are seen in New Zealand, South Africa, and California, although their geographical locations are in mid-latitude. The role of each species has significance in managing the overall structure and function of ecosystems of various geographical locations. The sustainability of the human race could only be possible due to the integrated and balanced interaction of all the components of the global ecosystem. Besides this, biodiversity is

1.1 Introduction

important due it to providing consumptive use value, productive use value, ethical value, and aesthetic value. Biodiversity data mining provides a wide range of information on the status and distribution patterns of life on the planet [17,18]. But the available diversified data of random, single sampling fashion of a specific location and time create a problem in the development of strategies relating to flora and fauna. In contrast, highly aggregated data on flora and fauna and taxonomic monographs provide comprehensive information on biodiversity across large spatial, temporal, and taxonomic scales. Disaggregated data can give information at microecosystem level [19,20], but are not helpful in analyzing the structure and function of macroecology [21,22]. The Botanical Information Network and Ecology Network (BIEN) [23]; the Global Biodiversity Information Facility (GBIF) [24]; the Global database of plant trait (TRY)[25]; and the sPlot Core Team [26] provide biodiversity data on disintegrated diversified patterns of life. Mostly, biodiversity data are displayed in public domains so that scientists and the public can have overall information on taxonomy, geographical distribution, and the structure and function of organisms [27]. With the help of the latest tools and technology available in the IT sector, a wide range of biodiversity data can be integrated on the basis of geographical location, and used for assessing functional ecosystems [28]. With basic information on integrated biodiversity traits, future strategies of species interaction and survival can be understood [29].

1.1.4 Developing a binding framework of environmental principles Challenges relating to the structure and function of environmental issues are transboundary in nature, however, some of them are global. Mostly, the global nature of environmental issues can only be handled with international cooperation and understanding. International environmental laws are for public interaction with understanding both at state level and international organizations. International environmental laws cannot be operated in isolation, but rather need international frontier organizations to anchor policies with perfect understanding. A wide range of international organizations with multilateral environmental agreements have been involved in bringing amendments to international policy framing for restoring deterioration to environments caused by drastic climatic changes (Table 1.1). So, International Environmental Law (IEL) is concerned with the attempt to control pollution and deteriorating ecological resources with a framework of sustainable development. IEL mainly deals with issues like biodiversity, climatic changes, greenhouse gases, toxic and hazardous substances, and air, land, sea, and transboundary water pollution, marine ecosystem conservation, desertification, and nuclear damage. So, in June 2014, the UN Environment Assembly at the United Nations Environment Program (UNEP), Nairobi, in collaboration with 193 state representatives as well as other stakeholder groups framed global environmental policies. Two major declarations regarding international environment laws are:

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1. The Declaration of the UN Conference on the Human Environment (the 1972 Stockholm Declaration); and 2. The United Nations Conferences on Rio Declaration on Environment and Development, 1992. Details on these two declarations have already discussed at the beginning of this text. International treaties adopted at regional and global levels are commonly referred to as multilateral environment agreements. A vast body of multinational environment agreements, comprising of more than 500 instruments, have been adopted so far. Each agreement addresses different issues with respect to international law framing. However, the differences of opinion are ultimately helpful in reaching final conclusions in multilateral decision-making. Environment policies and laws are mainly correlated with energy conservation and sustainability. Thus environment policies involve energy restriction, restoration, and regulation such as oil and natural gas operations or nonconventional energy resource management. So, government policy decisions should emphasis the regulation of resources, reducing the environment deterioration process from factors like unusual climatic changes, industrialization, and urbanization, and the restoration of the structure and function of rural communities. In connection to this, the role of environmental instruments is significant in relation to the functional aspects of ecosystem restoration. Environment policy instruments can be well linked with policy development and decision-making for better implementation (Fig. 1.1).

FIGURE 1.1 Types of environmental instruments for quality regulation.

1.1 Introduction

1.1.4.1 Environmental governance tools At government level policy decisions and strategies are implemented to have control over the stability and sustainability of the environment with a variety of instruments ranging from international agreements to national and local governance acts having control over incentivization or the monitor environment and sustainability impacts. Mostly, at government level long-term majors are taken toward regulation (issuing permits and licenses) and controlling compliance with regulations. Governments have a variety of environmental instruments for regulating the environmental behavior of companies and the public such as international conventions and treaties, legislation and regulations, policies and programs, permits and licensing, monitoring and control, and environmental impact assessments (Fig. 1.1). Besides regulative instruments, there are also economic instruments (e.g., environmental charges and taxes and emission trading schemes), and voluntary instruments (agreement on environmental performance negotiated with industry and the public), and market-based instruments (MBIs). The functional aspects are often based on instrument choice. MBIs are policy instruments for controlling markets, prices, and other variables to encourage and ensure polluters adapt suitable techniques to reduce the pollution burden on the planet. MBIs help provide guidelines to polluters by analyzing market failure on the basis of data availability on tax payment, overall expenditure of manufacturing process, and supply chain management. MBIs are otherwise known as economic instruments, price-based instruments, and new environmental policy instruments or new instruments of environmental policy. The most common examples are environment-related taxes, charges, and subsidies, emissions trading and other tradable permit systems, deposit refund systems, environmental labeling laws, licenses, and economic property rights. The European Union Emission Trading Scheme is a good example of an MBI to reduce greenhouse gas emissions. MBIs differ from other policy instruments such as voluntary agreements and regulatory instruments. Voluntary approaches in environmental policy are mainly based on negotiation with industry in which an industry can volunteer to participate in finding a means to reduce the level of pollutant output from manufacturing. Whereas regulatory instruments are classical instruments of politics, and are used to solve social or economic conflicts. Regulatory political interventions go beyond advisory services or financial incentives since they are binding regulations that can be implemented forcefully. In 1909, David Llyd George implemented regulation on environmental policy instrument on maximum industries of Britain [30]. The command and control approach is a rigid MBI for controlling regulatory instruments including emission standards, process specifications, limits on input and output requirements to disclose information, and audits. However, this approach has been criticized for restricting technology due to the lack of incentive

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for firms to innovate [31]. MBIs do not have any specifications to bring out reductions in emissions. But the command and control approach is more result oriented when regulators are faced with hurdles in MBIs. MBIs are suitable for dealing with local emission issues, and inappropriate for emissions with global impacts due to its inefficiency in coordinating international cooperation. MBIs may also be inappropriate for dealing with emissions with local impacts as trading would be restricted to within that region. They may also be inappropriate for emissions with global impacts as international cooperation may be difficult to attain.

1.1.5 Global climate change regime Development of human activity to mitigate global climate change is an important issue to understand the threat emerged due to adverse climatic changes. So, in order to bring about awareness on climatic change, on May 9, 1992, the UNFCCC was organized for international environmental treaty. This treaty was opened for signature at the Earth Summit in Rio de Janeiro, held between June 3 and June 14, 1992. It was then forcefully implemented on March 21, 1994. The main target of UNFCCC is to bring stability in greenhouse gas concentrations in the atmosphere at a level that will prevent hazardous anthropogenic interference with the climate system. The basic motivation of this treaty is to carry out further action on the existing scenario of the greenhouse gas profile as per the protocol of the UNFCCC agreement (Fig. 1.2). By the end of 2015, the UNFCCC had 197 parties. Since 1995, the Conferences of the Parties (COP) have been meeting to assess the progress in dealing with climate change. In 1997, the Kyoto Protocol was documented and forcefully implemented as legally binding obligations for developed countries to reduce the greenhouse gas load in the atmosphere over the period of 2008 12 [6]. In 2010, the UN Climate Change Conference was held in Cancun, Mexico, from November 29 to December 10. The is officially referred to as the 16th session of the COP 16 in relation to the UNFCCC and the 6th session of the COP serving as the meeting of the Parties (CMP 6) to the Kyoto Protocol. It was agreed upon that deep cuts in global greenhouse gas emissions are required in order to restrict the increases in global average temperature to below 2 C above preindustrial levels. However, the agreement calls on rich countries to reduce their greenhouse gas emissions as pledged in the Copenhagen Accord and for developing counties to plan to reduce their emissions. In 2012, in the Doha Amendment, the Protocol was amended to encompass the period 2013 20. In 2015, the Paris Agreement decided to keep the lower limit of global temperature increase below 1.5 0C. This is mainly to reduce the effect of green house gas emission to the atmosphere. The Paris Agreement was entered into use on November 4, 2016. Under the Paris Agreement, it was mandatory for every state to regularly report on the major steps taken to mitigate global warming [32]. However, no

1.1 Introduction

FIGURE 1.2 Global CO2 emissions. Source: With courtesy from Energy Information Agency, updated 10.10.2019.

mechanism encouraged a country to set a specific time bound target [33,34], but each target should go beyond previously set targets. In June 2017, the United States wanted to decline the agreement, before the end of the presidential term of president Donald Trump in November 2020. Soon after the Paris Agreement, in July 2017 the French government took the decision to ban all petrol and diesel vehicles by 2040. In addition, the government decided not to use coal to produce electricity after 2022 [35]. In order to reach the agreement’s emission target, Norway will stop selling petrol and diesel powered cars by 2025 [36] and the Netherlands will follow suit by 2030 [37]. The Dutch national rail network runs trains powered by wind energy [38]. The House of Representatives of the Netherlands passed a bill in June 2018, having the target of reducing greenhouse gas emissions by 2050 [39].

1.1.6 Imposing liability for environmental damage Earlier, damage to the environment was regarded as merely incidental due to usual human activities like industrialization, urbanization, and desertification by cutting down trees, dumping of pollutants into the environment, ecosystem alternation, and the emission of hazardous gases without any precautionary majors. Global environmental treaties have brought about the realization that

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environmental polluters must be held accountable for being the cause of specific pollution and they should be legally liable for environmental damage within their own territory or by activities that may be responsible for adverse issues related to the environment of neighboring nations or in the global environment. Many states feel that to reduce environmental damage is not the part of liability for the state government but an obligation. Most of the states feel that environmental damage due to war or any conflicts is an incidental, at national and international level. But, currently, to damage the environment is an important war strategy [40,41].

1.1.6.1 Types of liability for environmental damage In order to lead a normal life, a favorable environment is acceptable for all without any prejudice. For example, types of ecosystems prevailing in the habitable world, biodiversity and conservation of natural resources are key components of the planet, and strengthening them is our unavoidable duty. We should be liable for each and every impact to the environment. On the basis of cause, the regimes of liability for environmental disorder can be analyzed under two heads, namely (1) fault liability and (2) liability without fault.

1.1.6.1.1 Fault liability Fault liability is caused by the breaking of an international agreement(s) by a wrongful act responsible for damaging the environment at a global level. However, the plaintiff state has to provide the cause for such irresponsible acts and the nature of the damage suffered. Fault liability is based on a state failure to use due diligence to avoid causing damage. Violation of international treaties (agreements) is an illegal act applicable for a country responsible for causing damage to environment or any other ecosystem. One of the best examples of fault liability is the environmental damage in Pakistan and India caused by Iraqi military operations on Iran in 1980. But Iraq wanted to avoid fault liability for violating an international agreement by stating that the reason was for self-defense purposes, before the Trail smelter case. The Trail smelter rule is for “a framework for the analysis of interstate disputes with environmental dimensions” generally applicable to cases of pollution that are transboundary in nature. Another such fault liability case was the Corfu Channel case. In 1946, a British warship was stopped from passing through the Corfu Channel by Albanian military forces with antivessel mines. In response, the court concluded that it is “every states’ obligation not to knowingly allow its territory to be used for acts contrary to the rights of other states.” Thus Albania was held liable for damages caused to the British warship. After a gap of about 26 years, in 1972, the Stockholm Declaration incorporated the Corfu Channel standard in Principle 21, which prohibited states from allowing their territory to be used by other nations without proper permission. The Stockholm Declaration is identical to Rio Declaration 13, relevant to transboundary environmental damage stating that “States have [-----] the responsibility to ensure that activities within their

1.1 Introduction

jurisdiction or control do not cause damage to the environment of other States.” These legal provisions hold any source state responsible and liable for environmental damage crossing its borders and harming any neighboring state. Mainly, factors responsible for fault liability due to the violation of international obligations for environmental protection are based on a given state’s policy matters on how to tackle the embracing circumstances under which international treaties on environmental conservation are violated. 1. Absolute obligations and due diligence: Under absolute obligation a state is supposed to build efforts within the state as due diligence not to breach international treaties for any environmental damage. Under such an obligation, a state has to take care of arranging all necessary steps related to legislative, administrative, and juridical matters in order to protect the interest of other states by safeguarding the environment in and around their respective territories. 2. Obligation of conduct and obligation of result: According to the International Law Commission’s (ILC’s) Draft Articles on State Responsibility, there are two categories of obligations involved, namely obligation of conduct (Art20) and obligation of result (obligation to prevent a given event (Art.23)). In the former subclass, obligation of conduct, a state has to adapt a particular course of conduct. In the latter subclass, a state is free to have choice criteria to prevent specific occurrences of environmental disorders. 3. Circumstances precluding wrongfulness: Certain unavoidable factors like legitimate counter measures, consent, accidental events, distress, and a state of necessity are the prerogative of a state to overlook in relation to environmental damage to neighboring states while taking any precaution majors on any social or political activities that may beneficial to the state, but may bring harmful impacts to the environment of neighboring states or territories.

1.1.6.1.2 Absolute liability Under the provision of absolute liability, a state has to be held responsible by international law for activities not prohibited by international rules, but that harm another country’s environments. Violation of any such liability of international understanding may cause imposition of compensation on the basis of the intensity of harm caused to the environment of neighboring states. Thus such a regime of liability is absolute. Absolute liability differs from fault liability in many aspects such as it including environmental damage without violation of an international obligation, limitations on the functional scope of ultrahazardous activities, ex post facto of absolute liability commitments, and the necessity of a causal link between the activity and the harm caused. The ILC has adapted absolute liability or liability without fault. The World Commission on Environmental and Development (WCED) is of the opinion that

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absolute liability should work as a legal base for international transboundary harm [42]. A number of conventions have also cited absolute liability as in the case of the Space Lability Convention [43], which explains that “a State which launches a space object is liable to pay compensation for damage caused by its space object on the surface of the Earth or to aircraft in flight” [43]. The best example is in the case of the Soviet Cosmos 954 satellite [44]. In 1978, a Soviet satellite, Cosmos 954, using nuclear power as an energy source, accidentally malfunctioned and crash-landed in a sparsely populated area of Canada. Canada claimed compensation for the cleanup operation of the areas contaminated by the radioactive materials by invoking the 1972 Space Liability Convention [44]. Another example of absolute liability is the International Convention on Civil Liability for Oil Pollution Damage. Violation of such an international treaty on oil pollution damage is adapted to ensure sufficient compensation to the party who suffer from the oil pollution damage. The convention applies to all seagoing vessels actually carrying oil in bulk as a cargo, but only ships carrying more than 2000 tons of oil are required to maintain insurance in case of oil pollution damage.

1.1.7 The laws of environmental liability The consequences of environmental deterioration are damage to biodiversity, ecosystems, natural resources, and habitats. For instance the “use and throw” practices for the disposal of plastic carry bags destroy aquatic ecosystems and block sewage draining (Fig. 1.3). Legal responsibility for environmental protection is a practice by the government for the people to protect the environment from damage caused by fault liability or absolute liability. Thus the habit of taking care of the environment is unavoidable for the conservation of the planet, and imposing laws for violating international treaties should be exercised by states on the basis of geographical location and regional environment protection. Environmental protection laws provide guidelines to protect the environment from damage effectively. Meticulously planned environmental liability laws create economic incentives to protect ecosystems by extracting compensation from polluters for any harm that occurs. The legislature of a state is responsible for framing environmental liability legislation under both public and civil law. Under civil law, the victimized party in terms of harm to life, limb, health, or property is supposed to receive compensation as per the Environmental Liability Act framed by various international bodies. As a matter of international law, it can directly or indirectly affect the legal obligations of a state, and can be entrusted with law-making competence through the transfer of sovereign powers. But there is no international organization to ensure overall responsibility for global environment protection. In a developed country like the United States, most of its activities in environmental law making are governed by subsidiary organs and affiliated organizations

1.1 Introduction

and not by the General Assembly and Security Council. International governmental negotiating committees, the UNEP, and the Economic Commission for Europe (ECE) and specialized international organizations like the Food and Agriculture Organization (FAO), the World Health Organization (WHO), the International Atomic Energy Agency (IAEA), the World Metrological Organization (WMO), and the International Maritime Organization (IMO) are some of the main players in international environmental law making. These organizations frame environmental mandates on their constitutions or based on the constitutional mandate to protect health and property. Each such organization has their own specific target for making environmental protection laws of their interest. For example the constitution of the IMO makes environmental law for maritime safety and conservation [45]. The function of the IAEA is to provide safety for the protection of health and minimum danger to life and property [46], sanitation and environmental hygiene protection law is taken care of by WHO [47], the mandate of the FAO extends to the promotion of natural resources (including fisheries, marine products, and forestry) [48,49], and the WMO frames environmental protection law on meteorology to water problems, agriculture, and other human activities [50]. Some other international organizations like the International Labor Organization (ILO), UNESCO, and the International Civil Aviation Organization (ICAO) also often organize meetings to frame environmental protection laws. The

FIGURE 1.3 Water body contaminated with plastic waste. Photo near a public school, Delhi, India.

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ICAO is involved in mandating environmental standards for aircraft engine emissions and aircraft sound limitations as international standards. There are many “treaty-management” organizations to support international environmental protection “policy-making organizations” to deal with specific global, regional, or subregional treaty provisions. Besides this, subregional parties for treaty management participate in the adaptation of technical regulations designed as annexes to respective conventions or amendments in respective treaties. These treatmanagement organizations are not entitled to possess any legal capacity. However, they can organize at regional level to tackle environmental issues as confirmed by international organizations. On May 10, 2018, the UN General Assembly passed resolution 72/277 entitled “Towards a Global Pact for the Environment.” According to the resolution’s text, the assembly decided to have an ad hoc open-ended working group to assist the main international environmental organizations in supplying technical and evidence-based reports with a view of strengthening the work on international treaties on environmental protection. This concept of adopting ad hoc conferences is an old practice, and they are restricted to a specific number of sessions rather than as permanent committees [51 54]. Main target of International Environmental Law (IEL) is to control pollution and the depletion of natural resources within a framework of sustainable development. It is mainly based on international regulation created by states to resolve problem that arise between neighboring states. In order to arrest environmental degradation, huge efforts have been put into developing international understanding to prevent the damage caused to the planet. Among such understandings the Kyoto Protocol is an example of bringing the world together to save it from the hazardous impacts of pollution caused by human activities. Several hundred international environmental agreements exist, but most link only a limited number of countries. Bilateral and trilateral agreements are limited to countries that have ratified them, but are not essential in the international regime. The IEA has been keeping updated data on international environmental instruments. Major revision of environmental instruments occurred over the course of 2017, with the addition of numerous bilateral agreements. Lists of international environmental treaties, conventions, and other agreements are available in the public domain [55].

1.1.8 Environmental restoration and remediation 1.1.8.1 Environmental restoration Environmental restoration is not synonymous with ecological restoration or environmental remediation, but rather closely related to preventing ongoing degradation through which environmental damage will be reverse. The practice of environmental restoration is an important part of the citizens’ environmental movement. In 1987, John J. Berger in his book “Restoring the Earth” defined environmental restoration as “A process in which a damaged resource is renewed. Biologically. Structurally. Functionally.”

1.1 Introduction

Interventions of human activity can eliminate species and disrupt natural processes, degrading or even destroying complex local webs of life. Due to a lack of proper attention, the sustainable nature of ecosystems is gradually in the process of disappearing. In many parts of the world, ecosystems are no longer providing essential services such as food and water production, climatic regulation, carbon storage, crop pollination, and wildlife habits. Environmental restoration is a practice of repairing damaged environments to their normal state of existence. Thus environmental restoration is an integral part of the conservation toolbox. But environmental restoration is often taken as a casual practice with low priority. Rapid industrialization and urbanization practices demand environmental restoration, and have given new dimension to restoration ecology. Environmental restoration can be applicable to aquatic ecosystems like lakes, wetlands, rivers, and terrestrial ecosystems like grasslands, forests, flatlands, hill country, and mountain slopes, etc. In order to restore environments, environmental restoration planners evaluate the conditions of ecosystems and coordinate the supervision work on the restoration with environmental scientists and field workers to oversee the implementation of restoration projects and to develop new conceptual models and strategies for restoration, remediation, monitoring, or management. For these purposes, they incorporate data from ecosystems and geographical imaging system data to create restoration plans. Besides this, environmental planners survey and integrate data to determine present and future environmental conditions and to find ways and means for restoration needs. On the basis of data obtained, they develop environmental restoration projects and budgets, habitat management plans, and native flora and fauna restoration. They also supervise and provide technical guidance, training, or assistance to employees working in the field to restore habitats. In addition, they conduct feasibility and cost benefit studies for environmental remediation projects. A variety of tools and techniques are used in environmental restoration projects on the basis of the requirements of the nature of the project to be operated. Heavy equipment like cranes, graders, bulldozers, or excavators are commonly used for major projects. Even big trees are uprooted and transferred to other suitable places by huge excavators. High-tech processes such as those applied in the careful environmental control required in fish-hatchery procedures are used with computerized integrated software tools. Computer-based mapping has also become an important dimension of restorative work.

1.1.8.2 Ecological restoration Scientific study to understand the stability of an ecosystem is known as restoration ecology. Whereas the practice of restoring the structure and function of an ecosystem is known as ecological restoration. Ecological restoration is a specific process involved in the recovery of an ecosystem (bringing it back to normal

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condition) from the stage of structural or functional damage caused by interventions of human activity or adverse climatic changes. The Society for Ecological Restoration (SER), founded in 1988, is targeted to “advance the science, practice, and policy of ecological restoration to sustain biodiversity, improve resilience in a changing climate, and re-establish an ecologically healthy relationship between nature and culture” [56]. Ecological restoration practices develop resilient ecosystems that will be beneficiaries in adapting local environments from the damage caused due to climate changes or human interventions (Fig. 1.4). The biological significance of ecosystems is to keep the planet in a state of normal functioning and to provide food, energy (biofuel), water, and shelter to inhabitants for survival. It has been scientifically assumed that the current process of environmental degradation and destruction of the Earth’s biota may lead to catastrophic impacts to the world environment. It has been estimated that the current species extinction rate or the rate of the Holocene extinction, is 1000 to 10,000 times higher than the normal, background rate [57,58,59]. The Holocene extinction is referred as the sixth mass extinction or Anthropocene extinction, and is an ongoing extinction event of species in the present Holocene epoch as a result of human activity. The death of wildlife is mainly due to habitat destruction, an efflux of industrial toxic pollution into ecosystems, overhunting, invasion by alien species, and climate change. The conservation of currently viable habitats and the restoration of degraded habitats are two methods presently being practiced to bring retardation to the

Climate resilient ecosystem and live lihood

Ecological restoration and rehabilitation with normal pattern of nutrient cycling and biomass production

Data bank development of biodiversity of an ecosystem, structure and function analysis policy decision, implementation of policy, mitigation process development FIGURE 1.4 Ecological restoration process development.

1.1 Introduction

species extinction. The commercial applications of ecological restoration are gaining attention exponentially [60]. So, ecological restoration is the practice of sustaining the diversified life of the habitable world and developing a cordial link between ecosystems and human activity. The conservation and sustainable development of an ecosystem is only possible by means of an ecological restoration process. It combines a wide range of activities like erosion control, reforestation, removal of nonnative species and weeds, revegetation of disturbed areas, reintroduction of native of native species, and habitat and range improvement for targeted species. A variety of factors like disturbance (human-caused and naturally occurring disturbances), succession (community changes over time, especially following a disturbance), fragmentation (spatial discontinuities in a biological system where ecosystems are broken up into smaller parts through land use changes), ecosystem function (foundational processes of any natural system including nutrient cycles and energy fluxes), community assembly (a framework that can unify virtually all of (community) ecology under a single conceptual umbrella), and population genetics (species diversity for restoring ecosystem processes) are responsible for bringing damage to ecosystems. The restoration of ecosystems is mainly necessary due to numerous reasons including:

• • • • • •

to to to to to to

fulfill the need for drinking water and wildlife populations, mitigate climate changes, save endangered species, stop unnecessary human intervention, regulate the process of harvesting for continuity, and restore cultural practices relevant to ecosystems.

1.1.9 Environmental remediation The practice of removing pollutants or contaminants from environmental media such as soil, groundwater, sediment, seawater, or surface water for the protection of human health and the environment or from a “brownfield” site intended for redevelopment is known as environmental remediation (Fig. 1.5). A brownfield site is a specific area that is spoiled due to the presence or potential presence of a hazardous substance, pollutant, or contaminant. Remediation is generally an array of regulatory requirements, and can also be based on assessments of human health and ecological risks without any legislated standards. On the basis of state requirements, the act of environmental remediation varies from country to country. In the United States, the most comprehensive set of preliminary remediation goals is framed by the US EPA. In Europe they are implemented as Dutch standards. However, in the European Union, most industrialized nations have their own standard acts for environmental remediation. In Canada, the Canadian Council of Ministers of the Environment guides the provinces at a

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FIGURE 1.5 Different stages of the remediation of an ecosystem.

federal level in the form of the Canadian Environmental Quality Guidelines and the Canada-Wide Standard/Canada-Wide Standard for Petroleum Hydrocarbons in Soil.

1.1.9.1 Tools and techniques used in environmental remediation On the basis of environmental contamination, a variety of tools and techniques are presently in practice. Mainly the target is to reduce pollutant loads from the components (soil, groundwater, sedimentation, or surface water) of an ecological system for better health and leading a comfortable life.

1.1 Introduction

1.1.9.1.1 Soil remediation types and techniques The process of the decontamination of soil from pollutants is known as soil remediation or soil washing. On the basis of the nature of soil contamination, the application of specific tools and techniques is dependent on the preliminary survey report on the contaminated soil’s structure and function. Thermal Soil Remediation: Soil contamination with hydrocarbon compounds such as oil or other petroleum products are removed by a high-temperature treatment technique. Thermal treatment technology to reduce the hydrocarbon load of contaminated soil use a rapid process, but the process is energy intensive and can damage soil properties (Fig. 1.6). In this process, steam is forcefully injected through injection wells to vaporize volatile and semivolatile contaminants, and the vaporized components rise to an unsaturated (vapor) zone where they are removed by a vacuum extraction treatment. Encapsulation: In this process, contaminated soil is mixed with lime, cement, and concrete. This sort of practice protects neighboring soil areas from further

FIGURE 1.6 Thermal treatment technology for removal of hydrocarbon deposited soil.

25

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CHAPTER 1 Conceptual development for a clean environment

contamination. But the main problem with this remediation process is that the encapsulated soil cannot be used for any crop development or plantation in future. Air Sparging: Air sparging is also known as in situ air stripping or in situ vitalization. Air sparging is carried out by injecting highly pressurized air into contaminated soil to remove volatile organic compounds (Fig. 1.7). This method has been widely used in Europe since the 1980s [61]. In the soil vapor extraction (SVE) method, contaminated soil is subjected to vapor extraction using pipelines at multiple points. The pipelines are fitted at a 3 4 ft. depth on the basis of the location of contaminated zones. A blower is attached to wells, usually through a manifold, below the water table, thus, creating pressure. The pressurized air generates clusters of bubbles of contaminant air that move toward the unsaturated soils above. Vacuum points exposed to this unsaturated zone suck the contaminated vapors through the SVE system. In order to block the exhaustion of air bubble the ground surface is covered with a taro or

FIGURE 1.7 Process of air injection to contaminated ground water to remove toxic in vapour form.

1.1 Introduction

other conventional method for preventing exhaustion of surface air. The off-gas, referring to the contaminated vapor, is filtered through a bacterial filter system and activated carbon container to detain leftover pathogenic microbes and to reduce the foul smell of the vapor. Before emitting the vapor into the atmosphere, it is passed through a combustion chamber in order to ensure the efflux air free from any contamination (Fig. 1.7). Bioremediation of contaminant soil: Bioremediation is a biological method to bring down the pollution load in contaminated soil using organic pollutants, hydrocarbons, or petroleum-derived pollutants (Fig. 1.8). It is an in situ method where genetically engineered microbes (aerobic or anaerobic) are fed into the contaminated soil. The bacteria break down, degrade, transfer, and/or essentially remove contaminants or impairments of quality from soil and water. The metabolic processes of bacteria are capable of using chemical contaminants as an energy source, rendering the contaminants harmless or less toxic. (Courtesy source: https://en.wikipedia.org/wiki/In_situ_bioremediation#/media/ File:In_Situ_Bioremediation.png) Besides microbial soil remediation, phytoremediation methods can also be applicable to bring down the pollution load in soils (Fig. 1.9). Mostly, phytoremediation is suitable for soils contaminated with metals (Pb, Zn, Cd, Ni, Hg), metalloids

FIGURE 1.8 In situ bioremediation of contaminate soil and water, graphic presentation. With courtesy from Wikipedia, www.en.wikipedia.org.

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CHAPTER 1 Conceptual development for a clean environment

FIGURE 1.9 Model on phyto-remediation technology. 23 1 (As, Sb), inorganic compounds (NO2 3 , NH4 , PO4 ), radioactive chemical elements (U, Cs, Sr), petroleum hydrocarbons benzene, toluene, ethylbenzene, xylenes (BTEX), pesticides and herbicides (atrazine, bentazone, chlorinated and nitroaromatic compounds), explosives (trinitrotoluene (TNT), 2,4-Dinitrotoluene (DNT)), chlorinated solvents (trichloroethyllene (TCE), Perchloroethene (PCE)), and industrial organic wastes (pentachlorophenols (PCPs), polycyclic aromatic hydrocarbon (PAHs)). Phytoremediation is applicable where soil water is in a static environment, but having chronic soil contamination with pollutants. This method is successfully in practice for the restoration of abandoned metal mine workings and sites where polychlorinated biphenyls have been accumulated due to the mismanagement of coal mine discharges. Besides this, soils contaminated with pesticides, solvent, explosives, and heavy metals can be remediated by the planting of a variety of trees having the potential to degrade such toxic compounds. Plants like mustard (Brasica juncea L.; capable of remediating Cd, Zn, Hg, Cu, and radioactive Cs137), poplar tree (Populus deltoides; capable of remediating chlorinated solvents such as trichloroethylene or the well-known carcinogenic, carbon tetrachloride), Indian grass (Sorghastrum nutans; capable of remediating petroleum hydrocarbons), and

1.1 Introduction

FIGURE 1.10 Bioremediation of heavy metal contamination by sunflower plantation.

sunflower (Helianthus annuus L.) (Fig. 1.10) have been proven to be successful at hyperaccumulating contaminants at toxic waste sites. Sunflower plants have high potential to remove radioactive metals including Cs and Sr from superficial undergroundwater. When these plants are cultivated with other species, it seems to be a highly successful option for many sites, for example, waste mining sites. In situ oxidation: A wide range of contaminated soils can be cleaned by a chemical oxidation process, which involves the injection of strong oxidants such as hydrogen peroxide, ozone gas, potassium permanganate, or persulfates. Besides this, oxygen gas or ambient air can also be injected to accelerate the physiological function of microbes, which are ultimately responsible for the rapid degradation of organic contaminants. One of the major disadvantages of in situ oxidation is damaging anaerobic microbes, which prefer reducing environments.

1.1.9.1.2 Contaminated water remediation The contamination of waterbodies like lakes, rivers, oceans, aquifers, and groundwater is mainly due to human activities. Mainly, three types of water remediation practices are used:

• Conventional water treatment plants for the generation of standard drinking water

• In situ groundwater treatment/remediation • Ex situ (off site) groundwater treatment 1.1.9.1.3 Conventional raw water treatment Conventional raw water treatment consists of the several unit processes, namely coagulation, flocculation, clarification, and filtration, followed by disinfection at

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CHAPTER 1 Conceptual development for a clean environment

FIGURE 1.11 Conventional raw water treatment process for drinking.

full-scale (Fig. 1.11). If the raw water has a lot of dissolved solids, then it is subjected to presedimentation, maybe in the presence of granulated activated carbon (GAC). GAC is mainly used to disorder the water. Often, preoxidation is accomplished during conventional treatment at a suitable stage of the raw water treatment process. Based on need, membrane filtration or ultra-filtration is carried out in order to make sure there is no harmful bacteria contamination. Groundwater is the water present below the ground’s surface that saturates the pore space in the subsurface. Mostly, the world’s drinking water is drawn from boreholes or dug wells [1]. Due to human activity, often, groundwater is contaminated by a variety of pollutants emerging from industrialized water or due to the discharge of sewage systems into open fields without any pretreatment (Fig. 1.12). Sometimes, organic wastes or toxic chemicals are dumped or stored on land surfaces where they percolate into the underlying groundwater, resulting in it being undrinkable. Besides this, practices of overapplication of fertilizers or pesticides, spills from industrial operations, infiltration from urban runoff, and leaking from

1.1 Introduction

FIGURE 1.12 Groundwater contamination process, graphical model.

landfills are responsible for the increasing pollutant loads in Various physicochemical techniques or biological methods to reduce the pollutant/contaminate loads in groundwater. used method for cleaning groundwater is air sparging (Fig.

groundwater systems. have been developed The most commonly 1.13). Generally, this

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FIGURE 1.13 A typical air sparging system for removal of volatile organic compounds Bioremediation of contaminated soil.

method can be well applicable to subsurface contaminant waterbodies. When highly pressurized air is injected into subsurface contaminated groundwater, it results in the hydrocarbons present changing state from dissolved to vapor state. The vaporized air is passed out through a vacuum extractor. The extracted air or “off-vapors” are passed through a biofiltration system, activated carbon, and a combustion chamber, in order to make sure the air is free from any contaminant vapor particles, before refluxing to the atmosphere. Another method, called pump and treat, physically removes the water from the ground and treats it by way of biological or chemical means. Physical methods: Air sparging is the process of striping air into the contaminated water zone under high pressure. As bubbles rise, contaminants are released from the groundwater by physical contact with the air and are carried up to the unsaturated zone (i.e., the soil). As the contaminants move into the soil, a SVE system is usually used to remove the vapor. Mostly the dual-phase vacuum extraction method is used to remove contaminant vapors from the soil (Fig. 1.14). Chemical methods: Mostly chemical methods are expensive and time-consuming processes, but are unavoidable for certain contaminants. Carbon absorption, ion exchange, chemical precipitation, and oxidation are the most common methods used to clean groundwater as in the case of the remediation of contaminated soil. Biological treatment of groundwater: The use of genetically engineered microbes and plants to reduce the pollution load in culminated wastewater bodies

1.1 Introduction

Air treatment

Air and liquid separation O Se

Airflow in vadose zone supporting biodegradation due to pressure aced gradient

Horizontal lines

Groundwater

FIGURE 1.14 Dual-phase vacuum extraction (DPVE) method to remove contaminants vapor from the groundwater or soil.

is known as bioremediation. In situ bioremediation (ISB) is a relatively less expensive process, and is supposed to be the most environment-friendly method compared to other methods applicable to the remediation of groundwater pollution. This process can also be applicable above ground in land farms, tanks, biopiles, or other treatment systems. The Office of Superfund Remediation and Technology Innovation (OSRTI), an associate to the US EPA, uses an in situ groundwater remediation process. The information from the OSRTI is intended for the US EPA and state agency site managers and serves as a reference to designers and practitioners. ISB of groundwater involves, mostly, using indigenous bacterial flora that are capable of metabolizing contaminants responsible for groundwater pollution. Various types of additives are used to stimulated the functional behaviors of microbes, and accelerate the bioremediation process. Often, selective strains of bacteria are added into aquifers to enhance the overall process of bioremediation. This process is otherwise known as bioaugmentation. The physiology and biochemistry of bacterial systems involve both oxidation and reduction processes to sustain life. Both these processes need a variety of substrates available in the surrounding aquifers or surface soils. Groundwater contaminates are an excellent source of energy for the growth and development of bacteria. Groundwater contaminates act as electron accepters (oxidized compounds) and

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CHAPTER 1 Conceptual development for a clean environment

donors (reduced compounds) in the three major oxidation pathways, namely (1) aerobic respiration, (2) anaerobic respiration, and (3) fermentation. Contaminants get degraded by these oxidation pathways and change the format of groundwater to drinkable. By means of aerobic remediation, in the presence of oxygen, metabolic oxidations of contaminants occur. The oxygen serves as an electron accepter. Aerobic metabolism is most commonly exploited and can be effective for hydrocarbons and other organic compounds. Aerobic bioremediation is most effective in treating nonhalogenated organic compounds. Mostly, reduced contaminants can be aerobically degraded by aerobic bacteria already present in the surface environment. So, oxygen or chemical oxidants are directly injected into an aquifer or soil subsurface, and these release oxygen as they dissolve or are decomposed. The ultimate products of aerobic respiration are carbon dioxide and water. In situ anaerobic bioremediation is mostly carried out in groundwater contaminated with hydrocarbon compounds derived as byproducts from the petroleum industry (Fig. 1.15). This type of contaminant is deprived of oxygen. As aerobic bioremediation of groundwater is a rapid process compared to anaerobic bioremediation, the introduction of oxygen or other engineered oxidants to anaerobic environments brings favorable conditions to hydrocarbon compound contaminated groundwater for the degradation of contaminates. Various oxygen releasing compounds like calcium and magnesium peroxides are introduced to the saturated zone in solid or slurry phases. These peroxides release into aquifers. Peroxide compounds are

n-Alkanes

n-Heptadecane Iso-alkanes

Pristane

Aromatics hydrocarbons CH3

Aliphatic hydrocarbons

34

Cycloalkanes

Toluene Crude oil Pyrene

Phenanthrene

Heterocyclic compounds Nitrogens

Cyclopentane

Napthalene

Sulfurs

Oxygens

Chrysene

N S

Carbazole

Dibenzothiophene

O

Xanthene

Benzo (a) pyrene

FIGURE 1.15 Various types of petroleum-derived products that often contaminate groundwater.

1.1 Introduction

ultimately converted to their respective hydroxide by releasing oxygen. This method of the application of peroxide compounds is generally applied over a period of four to eight months. Mostly, magnesium peroxide has been used rather than calcium peroxide. Magnesium peroxide gets released slowly for a long period as compared to the calcium compound.

1.1.10 Environmental management and green economy Green economic means a cordial and harmonious link between human activity and sustainable environment management for the development of economy of a nation, and to bring sustainability in the pattern of life with comfortable livelihood. Green economic theory pleads a wide range of models representing the integrated relationship between people and the environment. Green economists implore that all aspects of economic policy framing should be based on the sustainability of the ecosystem and natural capital. Natural capital mainly refers to natural resources held by companies such as water and oil. A company should be accountable for the financial statement ensuring natural capital accounting. The present economic policy system is responsible for damaging our natural resources, which may be an alarming factor for the prosperity of future generations. It was expected that by 2015 the gross loss of one quarter national productivity would be equivalent to the follow up costs of climatic change and loss of biodiversity alone. The concept of green ecology is a new model that could be a bridge between economic development and ecosystem management. The green economy is an environment-friendly economy helpful in promoting all types of social welfare including health, wealth, and well-being. The green economy is based on sustainable development targeting economies in ways that benefit, not sacrifice, social justice and equality as well as the environment. The green economy reduces environmental burdens and simultaneously accelerates economic growth. In contrast, ecological economics is a transdisciplinary field that is more academically oriented toward understanding the interdependencies of human activities and ecosystem sustainability in much a wider sense including psychology, anthropology, and history. UNEP explained the green economy as “one that focuses on the human aspects and natural influences and an economic order that can generate high-salary jobs.” In addition, in 2011, UNEP Green Economy reports further clarified that “to be green, an economy must not only be efficient, but also fair. Fairness implies recognizing global and country level equity dimensions, particularly in assuring a just transition to an economy that is low-carbon, resource efficient, and socially inclusive.” Some classical economists have the view that green economics is a branch or subbranch of economics where traditional land is generalized to natural capital or it is viewed as Marxist economics or as a branch of neoclassical economics. But the UNEP and national governments such as in the United Kingdom have been emphasizing natural capital and environmental full cost accounting (EFCA) under the banner “green economy.” EFCA means cost accounting that traces direct costs and

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allocates indirect costs (environmental). In 2010, the Bretton Woods Institutions and the International Monetary Fund (IMF) initiated the necessary steps for universal biodiversity finance. The Bretton Woods Institutions are the World Bank and the IMF. They were set up at a meeting of 43 countries in Bretton Woods, New Hampshire, USA in July 1944, to develop the shattered post-war economy and to promote international economic cooperation. The International Chamber of Commerce (ICC) defined the green economy as “an economy in which economic growth and environmental responsibility work together in a mutually reinforcing fashion while supporting progress on social development” [62].

1.1.10.1 Pillars for green economy success In 2012, the ICC published the Green Economy Roadmap representing a comprehensive and multidisciplinary effort to explain the conceptual development of a “green economy.” The basic concept on green economy is the use of natural resources without damaging their regeneration capacity. Besides this, it is targeted at restricting activities that may bring harm to the planet. The green economy is mainly based on three pillars: People: The supply chain of any business transition should be cordially linked with suppliers, vendors, distributors, and other business entities. The business transition should carry moral ethic in providing products and services without the exploitation of labor communities, which may cause poor quality of life. Profit: In order to gain profit in business one should take care of sustainability in fair dealing with public and other stockholders involve in business management. In spite of having a profitable business, it is necessary to understand and ensure employees’ happiness and health. An environmentfriendly business will have a positive impact on the well-being of workers. Planet: Businesses should pay attention to the recycling processes of wastes, minimizing the energy use from natural resources, and practicing the use of nonconventional energy resources to bring sustainability to the planet.

1.1.10.2 Green Economy Index The profile of economic progress is expressed through the use of economic index indicators. Thus the green economy also possesses green indices to explain how the economy profile is progressing in relation with human ecological impacts, green logistic system management, efficacy in the use of energy, ecotourism, and invest flow strategies in building up renewable energy resources, green urbanization processes, and environment clean technology development and implementation. Keeping the said green indices in mind, in 2018, the Global Green Economy Index (GGEI) was published on the performance of 130 countries. The GGEI provides information on quantitative and qualitative assessment of the efficacy of a nation to resolve issues on adverse effect of climatic change and precaution major taken by

References

the government on ecological sustainability, and environmental protection through wastes recycling and renewable energy utilization.

1.1.10.3 Green energy for green economy The basic fundamental requirement of a green economy is green energy, which can be used to monitor the economic development process and help in reducing the burdens of greenhouse gases on the planet, responsible for climate change. Its mainly depends on the efficacy of replacement of renewable energy in place of luxuriously used conventional energy resources. Thus the German Renewable Act and the legislations of many other member states of the European Union and the American Recovery and Reinvestment Act of 2009, facilitate the use of renewable energy by supporting attractive funding from both government and private sectors for using renewable means of energy generation and utilization. German has target for generating energy (mainly electricity) to supplement 80% energy generated from conventional resources, by 2050 [63].

References [1] UN Resolution 2398, as quoted in L.K. Caldwell, International Environmental Policy: Emergence and dimensions. 2nd ed. Durham, NC: Duke University Press; 1990. [2] Fred P. Last chance to save the planet. New Scientist, May 30, 1992:24 8. [3] Paul H. Brazilian city of Curitaba Model of local action for global survival. The Star Phoenix 1992. [4] United Nations Conference on Environment and Development. Rio Declaration on Environment and Development. Habitat.igc.org. Archived from the original on 2 April 2003. [5] United Nations Agenda 21 Archived 10 May 2009 at the Wayback Machine. [6] United Nations Conference on Environment and Development. Agenda 21: Table of Bold textContents. Earth Summit, 1992. Habitat.igc.org. Archived from the original on 30 July 2014. [7] United Nations Framework Convention on Climate Change (2018) Wikipedia ,https:// en.wikipedia.org/. . ./United_Nations_Framework_Convention_on_Climate_Cha. . ... [8] Bentley historical library finding aids. Quod.lib.umich.edu; October 18, 1976. Retrieved April 22, 2011. [9] Historical timeline about UM SPH. Sph.umich.edu. Archived from the original on November 9, 2001. Retrieved April 22, 2011. [10] Earth Day co-founder Morton S. Hilbert dies. Ns.umich.edu.; January 5, 1999. [11] About Earth Day Network. Archived from the original on April 23, 2007. Retrieved April 15, 2013. [12] Earth Day: The history of a movement. Earth Day Network. Retrieved August 16, 2013. [13] Earth Day Network’s (2019), ,https://www.earthday.org/2019/. . ./earth-day-networks-2019-cleanup-spans-thousands-. . ... [14] Marine Conservation Institute, MPAtlas (Seattle, 2018), ,www.mpatlas.org . .

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[15] Lubchence J, Grorud-Colvert K. Making waves: the science and politics of ocean protection. Science 2015;ge1-7(350):6259. [16] Sala E, Lubchenco J, Grorud-Colvert K, Novelli C, Roberts C, Sumaila UR. Assessing real progress towards effective ocean protection. Marine Policy 2018;91:11 13. Available from: https://doi.org/10.1016/j.marpol.2018.02.004. [17] Wiens JA. Spatial scaling in ecology. Funct Ecol 1989;3:385 97. [18] Rahbek C. The role of spatial scale and the perception of large-scale species-richness patterns. Ecol Lett 2005;8:224 39. [19] Zanne AE, Pearse WD, Cornwell WK, McGlinn DJ, Wright IJ, Uyeda JC. Functional biogeography of angiosperms. Life at the extremes. New Phytol 2018;218:1697 709 pmid:29603243. [20] Bolnick DI, Amarasekare P, Arau´jo MS, Bu¨rger R, Levine JM, Novak M, et al. Why intraspecific trait variation matters in community ecology. Trends Ecol Evol 2011;26:183 92 pmid:21367482. [21] Bruelheide H, Dengler J, Purschke O, Lenoir J, Jime´nez-Alfaro B, Hennekens SM, et al. Global trait environment relationships of plant communities. Nat Ecol Evol 2018; pmid:30455437. [22] Meyer C, Weigelt P, Kreft H. Multidimensional biases, gaps and uncertainties in global plant occurrence information. Ecol Lett. 2016;19:992 1006 pmid:27250865. [23] Enquist BJ, Condit R, Peet RK, Schildhauer M, Thiers B. Cyberinfrastructure for an integrated botanical information network to investigate the ecological impacts of global climate change on plant biodiversity. Peer J Preprints 2016;4:e2615v2. [24] GBIF. The Global Biodiversity Information Faculty; 2018. Available from: ,http:// www.gbif.org.. [25] Kattge J, D´ıaz S, Lavorel S, Prentice IC, Leadley P, Bo¨nisch G, et al. TRY a global database of plant traits. Global Change Biol 2011;17:2905 35. [26] sPlot Core Team. sPlot—The global vegetation Database; 2017. Available from: ,https://www.idiv.de/en/sdiv/working_groups/wg_pool/splot.html.. [27] Hortal J, Bello F, de, Diniz-Filho JAF, Lewinsohn TM, Lobo JM, Ladle RJ. Seven shortfalls that beset large-scale knowledge of biodiversity. Annu. Rev. Ecol. Evol. Syst. 2015;46:523 49. [28] Brown JH, Lomolino MV. Biogeography. 2nd ed. Sunderland, MA: Sinauer Associates; 1998. [29] Violle C, Reich PB, Pacala SW, Enquist BJ, Kattge J. The emergence and promise of functional biogeography. Proc Natl Acad Sci USA 2014;111:13690 6. [30] Jordan A, Wurzel R, Zito R, Bruckner L. Policy innovation or ‘muddling through’? ‘New’ environmental policy instruments in the United Kingdom. Environ Politics 2003;12(1):179 200. [31] Guerin K. Property rights and environmental policy: a New Zealand perspective. Wellington: NZ Treasury; 2003. [32] Article 3, Paris Agreement; 2015. [33] Paris climate accord marks shift toward low-carbon economy. Globe and Mail. Toronto, Canada. December 14, 2015. Archived from the original on December 13, 2015. [34] Mark K. COP21: What does the Paris climate agreement mean for me?; 2015. [35] France will ban all petrol and diesel vehicles by 2040. The Independent. ,https:// www.independent.co.uk/. . ./france-petrol-diesel-ban-vehicles-cars-2040a782683. . ..; 2017. [36] Norway to ‘completely ban petrol powered cars by 2025’. Archived 20 June 2018 at the Wayback Machine, The Independent; June 4, 2016.

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[37] The Dutch government confirms plan to ban new petrol and diesel cars by 2030. Archived 20 June 2018 at the Wayback Machine, eletrek.co.; October 10, 2017. [38] Dutch electric trains become 100% powered by wind energy. Archived 20 June 2018 at the Wayback Machine, The Guardian; January 11, 2017. [39] Nederland zetzelfstokachter de deur: in 2050 95 procent minder CO2. Archived 20 June 2018 at the Wayback Machine, de Volkskrant (in Dutch); June 19, 2018. [40] Trail Smelter Case (United States v. Canada). Am J Int Law 1941;35:684 736. [41] International Law Commission (ILC). Draft articles on state responsibility, U.N. Doc.A/51 / 10, Article 19 (3) (d); 1996. [42] WCED. Our common future. Oxford: Oxford University; 1972. p. 349. Available from: https://link.springer.com/chapter/10.1007/978-1-349-62529-1_6. [43] Burke JA. Convention on International Liability for damage caused by space objects, note 36. ,https://lawnet.fordham.edu/cgi/viewcontent.cgi?article 5 1112&context 5 ilj.; 1984. [44] Cohen AF. Cosmos 954 and the International Law of Satellite Accidents. ,https:// digitalcommons.law.yale.edu . ; 1984. [45] Article 1 (a) of the Convention on the International Maritime Organization. In: Kapteyn P, et al., editors. International Organization and Integration, VOI.I.B. (1982), at 1.10.a. [cit. hereinafter: 1.0.1.]. [46] Statute of the international Atomic Energy Agency, Article III(A) paragraph 6, in: 1.0.1. (note 5), Vol.I.B. at 2.2.a. [47] The role of the World Health Organization, International Digest of Health Legislation 1995;46:422 7. [48] Article I paragraph 1 and paragraph 2(c) of the Constitution of the Food and Agriculture Organization of the United Nations, in: 1.0.1. (note 5), Vol.I.B. at 1.3.a. Article 37(e) and (k) of the Convention on International Civil Aviation (Chicago Convention), in: 1.0.1. (note 5), Vol.I.B. at 1.6.a. For the standards see ICAO: International Standards and Recommended. [49] Practices, Environmental Protection, Annex 16 to the Convention on International Civil Aviation, V61.1 Aircraft Noise, 3rd ed. (1993) and Vol.11, Aircraft Engine Emissions, 2nd ed. (1993). On the law-making activities of ICAO in general see T. Buergenthal, Law-Making in the International Civil Aviation Organization (1969). [50] Article 2(d) of the Convention of the World Meteorological Organization, in: 1.0.1. (note 5), Vol.I.B. at 1.9.a.Article 37(e) and (k) of the Convention on International Civil Aviation (Chicago Convention), in: 1.0.1. (note 5), Vol.I.B. at 1.6.a. For the standards see ICAO: International Standards and Recommended. [51] Scheriners/BIokker (note 2) state that it can be taken as “a general rule that an organ may create subsidiary organs to which it may delegate part of its functions, provided that such new organs do not increase the obligations of the organisation or of its members”. [52] U.N.GA Res.2997 on Institutional and Financial Arrangements for International Environmental Co-operation, 15 December 1972, 27 U.N. GA OR (Supp.No.30) 43. [53] U.N. GA Res.47/191 on the Institutional Arrangements to follow UNCED, 22 December 1992, U.N. Doc. A/47/719, p. 19 (1992). The CSD has the status of a functional commission of the ECOSOC. On the CSD see also P. Orliange, La commission du d6veloppement durable, Annuairefranqais de droit international 39 (1993), 824. [54] Part I paragraph 2(a) and Part II paragraph 2(e) of GA Res.2997 (note 19). [55] Wikipedia (2017) List of international environmental agreements (2016).

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[56] Society for Ecological Restoration (2018) Wikipedia. ,https://en.wikipedia.org/ wiki.. [57] Pimm SL, Russell GJ, Gittleman JL, Brooks TM. The future of biodiversity. Science 1995;269(5222):347 50. [58] Simberloff, Daniel (1996) Lawton, JH, May RM, editors. Extinction rates. Oxford: Oxford University Press; 1995. J Evol Biol 9(1):124 6. [59] Sciences, National Academy of (1988). Biodiversity. [60] Young TP, Petersen DA, Clary JJ. The ecology of restoration: historical links, emerging issues and unexplored realms. Ecol Lett 2005;8(6):662 73. [61] Brusseau ML, Maier RM. Soil and groundwater remediation. Environ Monit Charact 2004;335 56. [62] UNDESA. A guidebook to the Green Economy. Archived 2013-01-27 at the Wayback Machine; 2012. [63] The Energy of the Future: Fourth “Energy Transition” Monitoring Report - Summary (PDF). Berlin: Federal Ministry for Economic Affairs and Energy (BMWi). November 2015. Archived from the original (PDF) on 20 September 2016. Retrieved June 9, 2016.

CHAPTER

Greenhouse gas capture and conversion

2

Chapter Outline 2.1 Greenhouse gases and global warming................................................................ 41 2.1.1 History ............................................................................................41 2.1.2 Sources of greenhouse gases .............................................................43 2.1.3 Carbon capture, utilization, and storage..............................................44 2.1.4 Commercialization of carbon capturing process ...................................52 2.1.5 Greenhouse gas separation ................................................................55 2.1.6 Different cycle for CO2 adsorption......................................................62 References ............................................................................................................... 65

2.1 Greenhouse gases and global warming 2.1.1 History In 1824, Joseph Fourier conceived the idea of temperature regulation on the Earth’s surface. After a long gap, in 1938, Claude Pouillet confirmed the idea of temperature regulation on the Earth’s surface. In 1856, Eunice Newton Foote, further confirmed the idea of temperature rises on Earth’s surface by experimental observation [1]. Johan Tyndall also expanded on her work in 1859 by measuring the radiative properties of a wider spectrum of GHGs [2]. In 1896, further quantifying of this finding was carried out by Svante Arrenius. He was the first to predict that global warming due to the hypothetical doubling of atmospheric carbon dioxide concentration would lead to a 5
C temperature rise [3]. He noticed that the average temperature (about 15
C) on the Earth’s surface is maintained due to the absorption of infrared by water vapor and carbon dioxide present on the Earth’s surface (Fig. 2.1). Heat emitted from Earth’s surface gets back to Earth as GHGs stop it from being lost in space. This phenomenon is known as the natural “greenhouse effect” (Fig. 2.1). Arrenius and his colleagues came to the conclusion that human activities contribute carbon dioxide to the atmosphere, which is ultimately responsible for increasing the temperature on the Earth’s surface. This was not verified until 1987. In 1940, with the discovery of infrared spectroscopy for measuring longwave radiation, it was proven that increases in the amount of carbon dioxide resulted in greater absorption of infrared radiation. Besides this, it was also Environmental Technology and Sustainability. DOI: https://doi.org/10.1016/B978-0-12-819103-3.00002-0 © 2020 Elsevier Inc. All rights reserved.

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FIGURE 2.1 Diagram showing light energy, emitted by the sun, warms the earth’s surface which then emits the energy as heat, which warms the atmosphere and is then re-emitted as heat.

concluded that the presence of water vapor absorbs a totally different type of radiation than carbon dioxide. In 1955, Gibert explained that the addition of more carbon dioxide to the atmosphere would intercept infrared radiation that is otherwise lost to space, thereby warming the earth. In the 1950s, it was discovered that carbon dioxide has an atmospheric lifespan of approximately 10 years. But it was not clear the fate of dissolved carbon dioxide in the ocean. It was assumed that ocean carbon dioxide returned to the atmosphere after some time. The ocean is not a complete carbon dioxide sink. Only about one-third of atmospheric carbon dioxide is absorbed by the ocean. Between the late 1950s and early 1960s, Charles Keeling developed the most modern of technologies to map the concentration curve for atmospheric carbon dioxide in Antarctica and Mauna Loa. His finding of the atmospheric curve for carbon dioxide became the milestone for understanding global warming. In 1991, the term “greenhouse” was first proposed by Nils Gustaf Ekholm [4,5]. Surprisingly, in the 1980’s the global annual mean temperature curve started moving in ascending order. So, an upcoming new ice age was forecasted.

2.1 Greenhouse gases and global warming

So, many international nongovernmental organizations (NGOs) were showing how to prevent further global warming. However, in 1988, it was realized that the climate was warmer than any period since 1980. In order to tackle the problem of global warming seriously, in 1988, the Intergovernmental Panel on Climate Change (IPCC) was founded by the United Nations Environmental Program (UNEP) and the World Meteorological Organization (WMO). This organization is interested in forecasting the greenhouse effect according to existing climate models and to supply the public domain with literature on climatic change and global warming. The panel has more than 2500 scientific and technical experts from more than 60 countries all over the world. The main target of the IPCC is to provide the world with updated information on climatic change, its natural, political, and economic impacts and risks, and possible response options [6]. Later, the IPCC was endorsed by the United Nations General Assembly. Membership is open to all members of the WMO and the United Nations (UN) [7]. The United Nations Framework Convention on Climate Change (UNFCCC), the main international treaty on climate change, is associated with the IPCC in implementing functional decisions [8]. In 2018, the IPCC released the Special Report on Global Warming of 1.5
C. In 2019, the IPCC updated its guidelines on greenhouse gas inventories, and in the same year, a special report was delivered on the ocean and cryosphere in a changing climate (Special Report on Climate Change and Land; SRCCL).

2.1.2 Sources of greenhouse gases GHGs capture heat and enhance the planet’s surface temperature. Mainly, human activities have been the primary causes of GHG emissions into the atmosphere for many decades [9]. The primary GHGs in the Earth’s atmosphere are water vapor, carbon dioxide, methane (CH4), nitrous oxide (N2O), and ozone. About 32.5 billion metric tons of GHGs were released into the atmosphere in 2017 alone, rising 1.4% from 2016. This rise is the equivalent of having 170 million new cars on the road. With the current technology, it is possible to capture CO2 from the atmosphere and from industrial exhaust streams. Power plants, steel and cement factories, and distilleries, among others, produce carbon dioxide, which could be used as a source to produce methanol. The primary sources of GHG emissions are described in Sections 2.1.2.1 to 2.1.2.3.

2.1.2.1 Transport systems GHG emissions from transportation are primarily generated from the combustion of fossil fuels by common logistics systems like cars, trucks, trains, spacecraft, and planes. Over 90% of the fuel used for transportation is petroleum based, mainly primary gasoline and diesel [10]. Among the GHGs, carbon dioxide is supposed to be the main culprit. The global emission of carbon dioxide in 2018 was about 37.1 billion tons. The main contributors to carbon emission are

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China (4.7%), the United States (2.5%), and India (6.3%) of the total value of carbon emission in 2018.

2.1.2.2 Electricity production as a source of greenhouse gas Electricity production is responsible for generating the second largest share of GHG emissions. Approximately 62.9% of our electricity comes from burning fossil fuels, mostly coal and natural gas [1]. On the basis of total carbon contribution during 2017 (37 billion tons), industry (22.2%), commercial residences (11.6%), agriculture and land use and forestry (11.1%) also contributed significant amounts of carbon to the atmosphere.

2.1.2.3 Dairy farming as a source of greenhouse gas Global demand for dairy is on an ascending order due to population growth, rising incomes, urbanization, and westernization of diets in countries such as China and India. All over the world, there are about 270 million dairy cows to produce milk. The activities of dairy farms impact the environment in various ways, and the scale of these impacts depends on the practices of the dairy farmers and feed growers. Dairy cows and their manure produce GHGs, which ultimately affect climate change, releasing about 7.1 gigatons of CO2, amounting to 14.5% of all anthropogenic GHG emission per year contribute to atmosphere. The GHGs produced from dairy farms include enteric CH4 from the animals, CH4 and N2O from the manure in housing facilities during long-term storage and during field application, and N2O from nitrification and denitrification processes in the soil used to produce feed crops and pasture.

2.1.3 Carbon capture, utilization, and storage Carbon capture, utilization, and storage is a process of capturing carbon from flue gas (coal-fired power plants), and its further utilization for value-added chemicals or sequestration. The latter process is involved in the long-term storage of carbon dioxide or other forms of carbon to either mitigate or defer global warming and to resolve issues related climate change. It is a process to control carbon accumulation in the atmosphere and marine accumulation of GHGs resulting from the burning of fossil fuels.

2.1.3.1 Carbon sequestration process Carbon sequestration is a process involved in capturing carbon from flue gases for its long-term storage or to mitigate global warming [11]. This process may be helpful in slowing down carbon accumulation in marine environments and the atmosphere [12]. Biological, chemical, and physical processes are responsible for carbon sequestration [13]. Besides this, by using subsurface saline aquifers, reservoirs, ocean water, and aging oil fields, carbon capture systems can also be managed for the carbon capturing process. Nature itself acts as natural carbon sequester (Fig. 2.2).

2.1 Greenhouse gases and global warming

FIGURE 2.2 Schematic diagram showing both terrestrial and geographical sequestration of CO2 emission from biomass, PowerStation, industries and other sources.

2.1.3.1.1 Biological process Azolla filiculoides as carbon capture biological system. Biological sequestration refers to the process of capturing carbon by biological means. Azolla filiculoides has been noted as a highly potential aquatic weed having carbon capturing capacity. It can fix about 0.25 kg/m2/year of nitrogen annually. This is equivalent to 6 tons of carbon capturing per acre of land per year [14]. A limiting factor for this are the availability of phosphorus, carbon, nitrogen, and sulfur. The plant can grow at a great speed in favorable conditions [15]. A. filiculoides is a symbiotic aquatic fern with the cyanobacterium Anabaena azolla. Past records describe the interesting “Arctic Azolla Event,” which changed the global climate from hot to cool during the middle Eocene period [16,17]. The presence of an extensive layer of freshwater expanded over the Arctic Ocean with a massive bloom of A. filiculoides. With the passage of time the huge blanket of A. filiculoides shifted to the ocean and formed a huge biological deposit under anoxic conditions. The fast growth of A. filiculoides has attracted the attention of

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people as an alternate fuel. The oil yield of A. filiculoides is about 15% of the dry weight [1820]. Marine algae as a source of alternate fuel. Marine algae are proven to be an alternative potential source of energy-rich oils (seaweed oil or seaweed fuel). Currently lots of private sectors are involved in a big way in producing algal diesel commercially [3]. Five major algal diesel producers at global level are discussed here. 1. Algenol Biofuels This company is located in Sonoran Sesert (Mexico). The main target of the company is to produce biofuels in an environment-friendly manner without harming the surrounding ecosystem including its biotic components. In the beginning, the company’s target was to produce 6000 gallons per acre per year. But due to the decreasing oil price at global market the company has diverted attention to produce value-added biochemicals having high commercial market values. Besides this, Algenol Biofuels has developed a platform for converting CO2 to ethanol at low cost and high efficiency (1 ton of CO2 to 144 gallons of fuel/8000 gallons per acre per year). The technology was demonstrated in India, where Reliance Industries has commenced operation near Jamnagar Refinery in India. In April 2015, Algenol was part of a US trade mission to China. Reliance Industries has been working on hydrothermal liquefaction technology used to convert wet biomass into crude-like oil referred to as biooil or biocrude under a moderate temperature and high pressure. Algenol’s fuel production process is designed to convert 1 ton of CO2 into 144 gallons of fuel while recycling CO2 from industrial processes and converting 85% of the CO2 used into ethanol, gasoline, and diesel and jet fuels. Advanced fuel producing algae technology is successfully operating at Algenol’s headquarters in Fort Myers, Florida. The algal fuels produced by Reliance were approved by the US Environmental Protection Agency (US EPA) as advanced biofuel, meeting the GHG reduction requirements under the Renewable Fuels Standard. Fuels produced from Algenol are now eligible for a renewable identification number under the D5 classification. As part of this approval, the US EPA determined that ethanol produced from Algenol’s process resulted in an about 69% reduction in GHGs. The total cost of the project is US$116 million (Rs 6.2 billion) in algae, and US$93.5 million (Rs 5.0 billion) in Algenol, as part of its strategic partnership. 2. Solix Biofuels Solix has developed special photobioreactors in which batches of microalgal cultures are grown. These bioreactors have the provision of light and temperature controlling systems. These photobioreactors have the potential to produce seven-times as much biomass as open-pond systems. After reaching the maximum biomass production stage, solvents like benzene or ether are used to extract crude algal oil. Solix also works in collaboration

2.1 Greenhouse gases and global warming

with the Los Alamos National Laboratory to use its acoustic-focusing technology to concentrate algal cells into dense mixtures by blasting them using a sonication method. Oil is extracted by squeezing it out. This makes the extraction process much easier and cheaper as compared to methods using chemical solvents. Solix’s existing demonstration plant already cultivates around 2000 gallons of algae per year. Solix uses a special photobioreactor fitted with Solix Lumian panels that are designed to maximize both light penetration and efficient mixing of CO2 in order to optimize algae growth. 3. Sapphire Energy Sapphire Energy is located in Southern New Mexico. Sapphire’s focus is on “green crude,” a liquid that has the same composition as crude oil, and is, therefore, compatible with existing refineries. The company has already shown that its fuel can be used in cars and jets. Sapphire has a 100-acre pilot facility near Las Cruces, New Mexico. Their plan was to make 1 million gallons of diesel and jet fuel per year by 2011, 100 million by 2018, and 1 billion gallons per year by 2025. In 2009, the company provided jet fuel for two test flights, namely for Continental Airlines 737-800 and Japan Airlines 747-300. In 2012, the company provided its green crude diesel fuel to power Below the Surface’s Driving Innovative Racing Team (https://en.wikipedia.org i wiki i Sapphire_Energy), which established itself by setting the first official algae-fuel diesel motorcycle speed records through a series of race challenges in the United States and Mexico. In 2012, as stated by Forbes magazine, Sapphire Energy was predicted to market green crude in competition with petroleum by 2018, if it could produce a minimum of 5,000 barrels a day. But due to financial constraints and decreases in petrol price, the company ceased functioning by the end of 2018. 4. Solazyme Solazyme Inc. was established as a public-held biotechnology company in the United States with the mission of utilizing microalgae to create a renewable source of transportation fuel. Along with Sustainable Oils (Camelina-based biofuel) and a Honeywell subsidiary, UOP (biodiesel), Solazyme plans to supply 400,000 gallons of fuel to the Air Force and 190,000 gallons to the US Navy by 2010. In 2011, the company announced it had produced over 283,000 L of military-spec diesel (HRF-76) for the United States Navy. The initial fuel production for phase 1 of 550,000 L was completed ahead of schedule. In 2011, Solazyme went for a joint venture with agribusiness company Bunge Limited to developed renewable oils in Brazil using Solazyme’s algaebased sugar-to-oil technology [21,22]. In late 2015, Solazyme and Bunge announced an expansion of their joint venture to have Bunge market the food oils produced through the joint venture [23]. In 2016, Solazyme officially changed its name to TerraVia Holding Inc., with a refined focus on food, nutrition, and personal care. However, the company would produce algal fuel

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under Solazyme Industry [24]. The production of AlgaPrime DHA, a new algae-based specialty feed ingredient, is designed to reduce the aquaculture industry’s dependence on wild fish populations [25,26]. TerraVia used to grow microalgae in the dark, inside huge, stainless-steel containers. These enclosed fermentation tanks offer control, purity, and consistency to the fermentation process. The dark fermentation process provides the opportunity for microalgae to be produced in a diversity of geographies and seasons. The algae can be fed a wide variety of renewable plant-based carbohydrates as feedstocks. The algae then convert the sugar into oils, lipids, and proteins, which can be used in a variety of applications such as food ingredients and cosmetics. The majority of TerraVia’s products are produced at the joint venture facility with Bunge in Sao Paulo, Brazil. 5. Seambiotic Ltd. Seambiotic Ltd. was founded in 2003. It is an Israeli clean-tech company enlisting algae in the business of carbon capture. In 2007, ISRAEL21c was one of the first to report on Seambiotic’s pilot plant with Israel Electric Corporation in Ashkelon. The company business is growing and processing marine microalgae utilizing flue gas from coal-burning power stations as a source of carbon. The company grows microalgae in open ponds. Its 1000 m2 facility produces roughly 23,000 g of algae per day. Three tons of algal biomass would yield around 100200 gallons of biofuel. It formed a partnership with NASA to optimize the growth rates of its microalgae. The company also helps produce carbon credits as it reduces as the overall GHG emission coming from power plants. Seambiotic technology could reduce 1% of the carbon dioxide for every 25-acre algae pond. Ten pools per power plant can reduce 10% of this GHG believed to be contributing to climate change. Agriculture. Agriculture serves as both a source and sink for GHGs. Agriculture sinks are reservoirs of carbon captured from the atmosphere through the biological carbon sequestration process known as photosynthesis. The resulting biomass from photosynthesis can be used for fuel while the biochar byproduct can be utilized for applications in agriculture such as soil enhancer. It is claimed that soil enhancer can increase crop yields by 12.3%. The primary sources of GHGs in agriculture are the utilization of nitrogenbased fertilizer and emissions from fossil fuels like coal, gasoline, diesel, and natural gases. GHG emissions from livestock such as cows was discussed earlier in Section 2.1.2.3. Forestry residues. During tree harvesting in forests, a large amount of residual biomass such as leaves, branches, needles, and woodchips is generated. This waste biomass can be used as a feedstock for producing biochemicals such as renewable methanol. Forestry biomass resources have been estimated at around 140 million tons in the United States. In the European Union, it has been estimated that the total forest biomass amounts to 716 million m3 annually.

2.1 Greenhouse gases and global warming

2.1.3.1.2 Chemical technology for carbon capture Methods for carbon-neutral fuel (i) ETH Zurich technology Carbon-neutral fuel is produced using a method for generating energy without any GHG emissions or carbon footprint. ETH Zurich has developed an innovative technology for the production of liquid hydrocarbon fuel exclusively from sunlight and air. The entire thermochemical process operates under real-field conditions. The new solar mini-refinery is located on the roof of ETH’s Machine Laboratory building in Zurich. Carbon-neutral fuels will play a significant role in aviation and maritime transport sustainability. A typical solar plant was developed by ETH researchers that can produce synthetic liquid fuels. When these synthetic liquid fuels are combusted, they generate as much CO2 as was previously extracted from the air for their production. CO2 and water are extracted directly from ambient air and split using solar energy. This process yields syngas, a mixture of hydrogen and carbon monoxide, which is subsequently processed into kerosene, methanol, or hydrocarbons. The entire process chain can be divided into three thermochemical conversion process including (1) the extraction of CO2 and water from the air via an adsorption/desorption process and (2) these both then being fed into the solar reactor at the focus of a parabolic reflector. Solar radiation is concentrated by a factor of 3000, generating process heat at a temperature of 1500
C inside the solar reactor. At the heart of the reactor is a ceramic structure made of cerium oxide, which enables a two-step reaction for the redox cycle to split water and CO2 into syngas, and then (3) the mixture of hydrogen and carbon monoxide can be processed into liquid hydrocarbon monoxide and then into liquid hydrocarbon fuels through conventional or FischerTropsch synthesis. These drop-in fuels are ready for use in the existing global transport infrastructure. For in the long run, ETH researchers are in the process of fabricating a mega-system for the commercialization of this process. They have planned to construct a solar plant spanning an area of 1 km2, which could produce 20,000 L of kerosene a day [27]. Synthetic hydrocarbon from flue gas. Flue gas from power plants and the air are chief sources of carbon dioxide. The flue gas is cooled at a temperature of between 318K and 323K, and fed to an absorption column (scrubber) where solvent absorbs CO2. The CO2-rich solution is fed into a heater to increase the temperature of the solution, then into a stripper column to release the CO2. Hydrogen (H2) can be generated by the electrolysis of water using renewable energy. Coal can also be used in the production of the hydrogen, but that would not be a carbon-neutral source. CO2 and H2 generated in such processes can be used for methanol production. The catalytic hydrogenation of CO2 with H2 is a common method for methanol and dimethyl ether (DME) production from CO2 as shown here:

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FIGURE 2.3 Natural process of carbon dioxide capture and recycling.

CO2 1 3H2 2CH3 OH 1 H2 O Δ H 298K 5 2 11:9 kcalmol

CO2 is the primary greenhouse gas and is periodically exchanged within land surfaces, oceans, and the atmosphere. In order to reduce GHG emissions, CO2 sequestration and storage has been a primary issue among environmentalists [28]. Therefore the utilization of CO2 and its conversion into value-added fuels and chemicals like ethanol, methanol, and formic acid have received the attention of industrialists. Although the process of carbon capture and recycling exists in nature (Fig. 2.3), it is an attractive issue all over the world [2931]. Methanol is a clean source of energy that can be produced from any raw material containing carbon. In methanol combustion, no GHGs are produced. So, methanol can be used in direct methanol fuel cells. This is mainly based on use of conventional chemical energy to generate electric power under ambient condition [32]. The annual production of methanol is about 65 million tons worldwide [33]. Acetic acid can also be produced from methanol, meeting 10% of the demand globally [34]. In 2015, Carbon Recycling International (CRI) [35], the world largest carbon methanol plant, upgraded its plant from a 1.3 million liter a year capacity to a 5 million liter a year capacity. This plant receives energy from the Icelandic grid that is generated from geothermal and hydro energy [36].

2.1 Greenhouse gases and global warming

FIGURE 2.4 Production of variety of daily uses materials from carbon dioxide.

As shown in Fig. 2.4, the plant uses electricity to make H2, which reacts with CO2 in a catalytic reaction for methanol production. Methanol can also be used to produce dimethyl ether. It can be used as a substitute for diesel fuel due to its ability to self-ignite under high pressure and temperature. It is nontoxic, but must be stored under pressure [37]. Larger hydrocarbons [38] and ethanol can also be produced from carbon dioxide and hydrogen. Mostly, synthetic hydrocarbon is produced at temperatures between 200
C and 300
C and at pressures between 20 and 50 bar. Such a reaction is exothermic and uses about 3 mol of hydrogen per molecule of carbon dioxide involved. Large amounts of water are produced in such a reaction as a byproduct. (ii) Seawater for synthetic liquid fuel The US Naval Research Laboratory (NRL) demonstrated a novel gas-to-liquid process that simultaneously recovers carbon dioxide and hydrogen from seawater, which can be ultimately converted to a fuel-like hydrocarbon liquid to replace petroleum-based fuel in jet engines. The concentration of CO2 in liquid fuel is much higher than that in the air. By using electrochemical acidification cells, H2 can be produced as a building block of hydrocarbon. The production of hydrocarbon from seawater is a two-step process. In the first phase, CO2 and H2 are converted into unsaturated hydrocarbon starter molecules called olefins using an iron-based catalyst. In the second phase, the olefins are converted into a liquid containing larger hydrocarbon molecules with a carbon range suitable for use in jet engines by polymerization. All these developments are, at present, in

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laboratory stage, but it is expected that the fuel-like liquid system will contain C9C16 range liquid fuels suitable for jet engines. In this process, the CO2 removal efficacy is 92%.

2.1.4 Commercialization of carbon capturing process 1. Solar energy and hydrogen research (ZSW) Although CO2 is a primary source of the greenhouse phenomenon, it has a variety of uses in our daily life, if the gas is captured and subjected to proper sequestration (Fig. 2.5). The Centre for SolarEnergy and Hydrogen Research (ZSW) at BadenWurttemberg, and Fraunhofer Society in Germany were established in 1988. It is a nonprofit foundation under the civil code. In 2011, under the direct supervision of these research institutes electric power generation plants were developed by using CO2 from local resources. In 2012, ZWS commenced the operation of a 250 kW pilot plant with 10 times the capacity of the original container-integrated test plant. With the knowledge and experience gained from this project, in 2015, ZSW began coordinating the flagship project

FIGURE 2.5 Power-to-Gas: Process scheme and integration in the energy system.

2.1 Greenhouse gases and global warming

“Power-to-Gas Baden-Wuttemberg” (6000 kW). As a part of this project, the newest scientific developments were used to enable the profitable operation of the technology. The goal was to generate renewable hydrogen that is suitable for cell-powered cars by converting electricity using electrolysis. The ZSW developed a power-to-gas (P2G) process using excess electricity from fluctuating sources into hydrogen. It can be instantaneously used as clean energy or turned into methane using carbon dioxide in a subsequent step. For this purpose, ZSW is in the process of developing electrolyzer and synthesis reactors. Solar and wind power is used for this purpose. Hydrogen and methane generated in this process can be used to power climate-friendly fuel cell vehicles or as natural gas (Fig. 2.4). Although the individual steps for the electrolysis and methanization processes associated with P2G have been known for a long time, much improvement in efficiency has been made while operating the two processes in combination. Renewable methane produced from wind and solar energy can be fed into an established gas grid and efficiently stored there. The P2G process has led to the development of infrastructure like pipeline networks, gas tanks, and underground caverns having storage capacities of more than 200 TWh. Both methane and, to a limited extent, hydrogen can be integrated, distributed, and made available, conveniently. The gas can be stored without any loss for several months in underground storage systems. Possible sources of CO2 that could be used in the methanization process include biogas plants, bioethanol production plants, power plants, and the chemical industry. Currently, ZSW is investing in other sources of CO2 as well. In addition, the P2G system has the target of securing Germany’s technological lead, reducing its dependence on natural gas imports, and lessening its mobility sector’s dependence on petroleum. 2. George Olah carbon dioxide recycling plant The George Olah carbon dioxide to renewable methanol plant is located at the Svartsengi geothermal power station in the town of Grindaviki in Reykjanes, Iceland. In 2012, the project was developed with a budgetary provision of $8 million. It is named in honor of the Nobel laureate in chemistry, George Olah. The plant is owned by CRI. It is jointly operated by HS Orka and CRI. In 2012, the project was targeted at obtaining 5 million liters of renewable methanol per annum, which was sufficient to meet about 2.5% of the total gasoline market in Iceland. The company has the target of using 10% furl blends from renewable sources by 2020. At present, EU/EEA fuel quality regulations in Iceland allow mixing of up to 3% methanol with gasoline fuel in automotive vehicles for transport. For a decade, CRI has successfully demonstrated the process, technology, and scalability of its emission-to-liquid (ETL) technology. Renewable methanol is an advanced fuel for transport, a greener substitute for conventional fossil resources, and provides benefits for the economy and the environment. ETL technology can challenge any other technology related to

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renewable methanol production from waste biomass or CO2 conversion into chemicals through biological pathways. Generally, high-temperature and high-pressure thermochemical processes with heavy capital investment are applied for synthetic hydrocarbon fuels production. Coal and gas mined in remote areas are transferred with heavy costs. Besides this, conventional production increases carbon dioxide emissions, and, at a small scale, these processes are not economical. But ETL technology is a low-cost process for the conversion of renewable energy into liquid fuel, even at small scale level. In this process, energy can be used from any renewable source including geothermal, hydro, wind, or solar. The ETL process is based on electrolytic cracking and catalytic synthesis, leading to a low-pressure and low-temperature electrochemical production process. The implementation of CRI’s technology to produce renewable methanol can be done in a phase and in a modular construction approach. The patented ETL process is free of carbon dioxide emission. Iceland has abundant natural resources of geothermal power, which account for 25% of the electricity generation in the country. As compared to standard fuel, CRI’s reporting mart (RM) is expected to reduce GHG emissions by about 75%. The RM produced through ETL technology has high levels of octane and blending, which enable the emission of lesser hydrocarbons and toxic compounds. It is less flammable, biodegradable, and is expected to become a suitable source across Europe. 3. Bayer MaterialScience CO2-to-plastic In 2011, Bayer MaterialScience (BMS) established a new pilot plant at Chempark Leverkusen, North Rhine-Westphalia region of Germany for producing plastics from CO2. The target of this project is to use waste gas released during power generation for the synthesis of polyurethanes, a base material for plastic. At the initial stage of development, the company target was the commercialization of the product in 2015. The process technology for polyurethanes is based on a zinc catalyst that was developed by scientists of CAT Catalytic Center, BMS, and RWTH Aachen University. The process is also expected to boost sustainability by decreasing the impact of CO2 on global warming. The project received funds from the German Federal Ministry of Education and Research (BMBF). CO2 acts as a substitute for the petroleum production of plastic. Polyurethanes are used to produce a variety of products used in daily applications. Polyurethane works as a good insulator material in buildings, which can save about 80% of the energy that is consumed during production. Light weight polymers are used in the automotive industry, upholstered furniture, and mattress manufacturing. Two monomer units of isocyanates (polymeric isocyanates or diisocyanates) and polyols react together to form polyurethanes. It is a catalytic base reaction. The waste carbon dioxide gas was recycled and used as a raw material in the pilot plant. It produced polyether polycarbonate polyols (PPPs), the chemical precursor of

2.1 Greenhouse gases and global warming

which is processed into polyurethanes. BMS is on the way to developing polyurethane for use in rigid and soft foam production. The company receives CO2 feedstock for the pilot plant from a lignite power plant in Niederaussem, operated by RWE. 4. Covestro manufacturing plastic from carbon dioxide Covestro AG is a German company that manufactures specialty chemicals for heat insulation foams and transparent polycarbonate plastic. It is a Bayer spin-off formed in the fall of 2015, and was formally called BMS, Bayer’s US $12.3 billion materials science division. Covestro shares were first offered on the Frankfurt stock exchange in October 2015. In 2018, Bayer sold its entire remaining stake. At present Covestro AG is among the world’s largest polymer companies. Business activities are focused on the manufacture of high-tech polymer materials and the development of innovative solutions for products used in many areas of daily life. Covestro has 30 production sites worldwide. Covestro polyurethane was used in the 2014, FIFA World Cup official football. At the beginning of 2019, Covestro achieved maximum market. The company is aimed at manufacturing CO2-based polyols at its Dormagen site for the production of toluene diisocyanate (TDI), a polyurethane precursor. This plant went on stream in late 2014, and is the basis for future optimization at the Dormagen and Brunsbuttel sites. The company engages in joint research projects with leading German universities and scientific institutes. One of its partners is CAT Catalytic Centre in Aachen, which is operated jointly by the university there and Covestro. Polyols and polyurethanes are normally based on petroleum. Now CO2 can replace petroleum. The new process, thus, supports a transformation of the raw material basis and contributes to sustainability.

2.1.5 Greenhouse gas separation GHGs composed of natural gases can consist of water vapor (H2O), carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and gases resulting from human activities (Fig. 2.6). These gases are mainly perfluorocarbons (CF4, C2F6), hydrofluorocarbons (CHF3, CF3CH2F, and CH3CHF2), and sulfur hexafluoride (SF4). Among all these gases, water vapor is the most predominant followed by carbon dioxide.

2.1.5.1 Carbon dioxide separation methods Mainly, absorption, adsorption, cryogenic distillation, and membrane separation techniques are employed on the basis of the nature of flue gas [36,39,40]. There are three basic steps for CO2 separation (Fig. 2.7). Various types of solvents are used for GHG separation (Table 2.1).

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FIGURE 2.6 Various methods are available on carbon dioxide separation.

2.1 Greenhouse gases and global warming

FIGURE 2.7 Three basic approaches of CO2 capture [29].

2.1.5.1.1 Absorption This method is based on a solvent extraction process [62]. Flue gas rich in CO2 is injected into a vessel containing solvent (bulk phase). Inside the temperature of the vessel is maintained at a cool condition between 318K and 323K. The cooled solvent is then injected into an absorption column (scrubber). The carbon dioxidesaturated solution is fed into another stripper column having the provision of a heater to remove CO2. The released CO2 is subsequently passed into a compressor chamber (knock drum). The regenerated absorbent solution is cooled and

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Table 2.1 Various solvents suggested for CO2 separation. Group of solvents

Advantage

Disadvantage

Application

1. Requires low energy for regeneration (less than 20% of the value of chemical absorbent) 2. Low vapor pressure, low toxicity, and less corrosive solvent

1. Dependent on temperature and pressure, therefore, they are not suitable for postcombustion process 2. Low capacity for CO2 absorption

Natural gas sweetening

Alkanolamines: monoethanolamine (MEA), diethanolamine, and methyl diethanolamine

1. React rapidly 2. High selectively (between acid and other gases) 3. Reversible absorption process 4. Inexpensive solvent

Amino acid and aqueous amino acid salt

1. The possibility of adding a salt functional group 2. The nonvolatility of solvents 3. Having high surface tension 4. Having better resistance to degradation than other chemical solvents 5. Better performance than MEA of the same concentration for CO2 absorption

1. Low CO2 loading capacity 2. Solvent degradation in presence of SO2 and O2 in flue gas (concentrations must be less than 10 ppm and 1 ppm respectively) 3. High equipment corrosion rate 4. High energy consumption Decreased performance in the presence of oxygen

Reference

Physical Dimethyl ether of polyethylene glycol (Selexol) Glycol Glycol carbonate Methanol (Rectisol) Fluorinated solvent

[36,4144]

Capturing CO2 and H2S at higher concentrations Separating CO2 from other gases CO2 removal from various streams i. CO2 removal from various streams ii. Separating CO2 from other gases

Chemical Important for removing acidic components from gas streams

[4550]

Suggested for CO2 separation from flue gases

[5154]

Ammonia

Ionic liquid

Aqueous piperazine (PZ)

1. No degradation in the presence of SO2 and O2 in the flue gases 2. No corrosion affect 3. Requires low energy for regeneration (1/3 of that required with MEA) 4. Low costs with aqueous ammonia, respectively 15% and 20% less than with MEA 1. Very low vapor pressure 2. Good thermal stability 3. High polarity 4. Nontoxicity 1. Fast absorption kinetics (CO2 absorption rate with aqueous PZ is more than double that of MEA) 2. Low degradation rates for CO2 separation 3. Negligible thermal degradation in concentrated PZ solutions 4. Favorable equilibrium characteristics 5. Very low heat of absorption (1015 kcal/mol CO2), 80% 90% energy required for aqueous amine system

1. Reversible at lower temperatures (not suitable for postcombustion) 2. Production of solid products and their operating problems 3. Explosion of dry CO2NH3 reaction with high concentrations of CO2 in the flue gas (explosive limit for NH3 gas is 15% 28%)

Suggested for CO2 separation from flue gases

[36,55]

Increased viscosity with CO2 absorption

Suggested for CO2 separation from flue gases

[5659]

Lower oxidative degradation of concentrated PZ (i.e., 4-times slower than MEA in the presence of a combination of Fe21/Cr31/Ni21 and Fe21/V51)

1. Effective for treating syngas at high temperatures 2. Application of additional amine promoters for natural gas treating and CO2 separation from flue gases

[41,50,60,61]

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FIGURE 2.8 General process diagram for CO2 capturing process.

subjected to a recycling process for further use [63,64]. A suitable solvent is selected, having a high potential for holding maximum CO2, which can reduce the process cost [65,66]. The entire absorption process is depicted in Fig. 2.8. Nature of solvent. The selection of a suitable solvent is based on how it interacts with carbon dioxide. In the physical absorption process, CO2 becomes soluble within the solvent without any reaction. Whereas in the chemical reaction, the CO2 molecule binds with the specific solvent forming a weak bond. Chemical absorption occurs at low CO2 partial pressure and low temperature [67,68]. Numerous solvents have been developed since the first chemical absorption process was patented in the early 1930s. For flue gas emissions from cement production, iron and steel manufacturing, and fossil-fuel power plants, a special type of solvent formulation is required to recover a small amount of CO2 present in a huge volume of flue gas. 1. Alkanolamines: This type of solvent is commonly used for CO2 separation. But the problem with this solvent is the corrosion of the vessel used. Among alkanolamines, monoethanolamine (MEA) is supposed to be the most suitable compared to other alkanolamines. This solvent reacts with CO2 quickly. But methyl diethanolamine (MDEA) has a higher CO2 absorption capacity and requires less energy to generate CO2 [36,42,45]. 2. Amino Acids: Amino acids have the same functional groups as alkanolamines. The main advantage with amino acid is its stability in the presence of oxygen. Glycine, alanine, dimethyl glycine, diethyl glycine, and a number of sterically hindered amino acids [49,50,52] are used on the basis

2.1 Greenhouse gases and global warming

of the nature of the flue gas used and their absorption quality. Based on the results of tests, aqueous potassium salts (composed of sarcosine and proline) are proven as promising solvents. 3. Ammonia: The chilled ammonia process (CAP) is also used for CO2 separation. In this process, CO2 is absorbed in an ammoniated solution at low absorption temperature (275K283 K), which reduces the ammonia emission from the CAP absorber. Ammonium carbonate solution has the capacity to retain about 38% CO2 as compared to MEA solution [69,70]. The disadvantage of this process is the toxicity of ammonia. The prevention of ammonia “slip” into the atmosphere is an important precaution. 4. Aqueous Piperzine (PZ): The kinetics of CO2 absorption can be control using a formulation of suitable amino acids and PZ. The PZ is an additive used for amine system to improve the kinetics of CO2 absorption such as MDEA/PZ or MEA/PZ blends. The solubility of PZ in water is low (between 0.5 and 2.5 M). The kinetics of CO2 absorption in solvents vary with the concentration of PZ used. Adsorption. The adsorption process is cost effective and suitable for reducing energy utilization. In this process, adsorbate molecules are separated selectively from a gas mixture either by making a bond with the sorbent or by attaching themselves to the solid matrix by weak intermolecular forces. The adsorbents used for CO2 separation are categorized into two groups, namely (1) physical and (2) chemical adsorbents. Chemisorption is a subclass of adsorption, driven by a chemical reaction occurring at an exposed surface. A wide range of metals have been identified for the adsorption of CO2 including (1) metal oxides like CaO2, MgO, (2) metal salt from alkali metal compounds like lithium silicate, lithium zirconate, to alkaline earth metal compounds (i.e., magnesium oxide and calcium oxide), and (3) hydrotalcites and double salts. The reaction of metals with CO2 is reversible. At any time, one molecule of metal compound can react with one molecule of CO2. In a series cyclic catalytic reaction, at 923 K temperature, metal oxides (such as CaO, MgO) are transformed into metal carbonates (CaCO3). This reaction is performed in a carbonation reactor at 1123 K to generate the sorbent and concentrated CO2. The sorbent is recycled for further processes and the CO2 is stored for commercial use. An important aspect in this process is the availability of an adequate amount of raw material (e.g., lime stone) at low cost. Calcium oxide has a high CO2 adsorption capacity. Lithium salt has also a high CO2 adsorption capacity, but due its high cost, it is not acceptable for commercial use. The reaction of CO2 adsorption with Li2ZrO3 is reversible in the temperature range 723K863K. The capacity of lithium silicate (8.2 mol CO2/kg sorbent at 993K) is higher than that of zirconate (4.85 mol/kg sorbent). Although nanomaterials application for CO2 adsorption is high, due to its high cost and complicated reaction steps this process is not acceptable for commercial exploitation [71,72]. The main drawback of this CO2 adsorption process is the difficulty in regenerating the sorbent.

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2.1.5.1.2 Physical adsorption Physical adsorption (physisorption) is a process in which the target substance is attached to a chip as a result of hydrogen bonding, Van der Waals forces, electrostatic forces, and hydrophobic interactions. The major physical adsorbents commonly used for CO2 adsorption include activated carbons and inorganic porous materials such as zeolites [73,74]. Coal is also suggested for CO2 separation. Activated carbon (AC) has interesting properties such as its high adsorption capacity, high hydrophobicity, insensitivity to moisture, and ease of regeneration [7577]. Besides this, ACs are inexpensive and easy to procure. Zeolite materials are a good choice for carbon capturing systems due to their porous diameter, charge density, and the chemical composition of cations in their porous structure. The average value of heat adsorption on zeolites (36 kJ/mol) is larger than that for AC (30 kJ/mol). Moreover, AC can be regenerated easily and completely. Also, it can be recycled for about ten conjugative processes without any loss in its CO2 adsorption potential [7880]. Active research has been focused on the production of active carbon from agricultural wastes including the shells and stones of fruit and wastes resulting from the production of cereal, bagasse, and coir pith. ACs from hemp stem are microporous materials and, therefore, suitable for hydrogen storage and CO2 capture [81].

2.1.6 Different cycle for CO2 adsorption In a single-bed CO2 adsorption process, five different regeneration strategies are presently in practice. This includes pressure swing adsorption (PSA), temperature swing adsorption (TSA), vacuum swing adsorption, electric swing adsorption (ESA), and vacuum swing adsorption (VSA) (Fig. 2.9). These technologies are differentiated based on the strategy for the regeneration of the adsorbent after the adsorption step. In PSA application, the pressure of the bed is reduced. The VSA is a better option as compared to PSA in which desorption pressure is below atmospheric. In TSA, the temperature is raised while pressure is maintained approximately constant, and in ESA the solid is heated by the Joule effect [8386]. Perform of different adsorption processes is given in the Table 2.2.

2.1.6.1 Cryogenic distillation The cryogenic separation process involves the low-temperature condensation, separation, and purification of CO2 from flue gases (freezing point of pure CO2 is 195.5K at atmospheric pressure). So, cryogenic separation involves a sequential process of compression, cooling, and expansion steps. In this process, liquid CO2 is directly produced and can be stored or sequestered at high pressure via liquid pumping [8688]. The main advantage of this process is that liquid CO2 is directly produced, thus, making it relatively easy to store. This technology does not involve any

2.1 Greenhouse gases and global warming

FIGURE 2.9 Schematic diagrams of various adsorption cycles; (A) TSA, (B) PSA, (C) VSA, and (D) ESA; thin lines indicated operation streams in regenerated step.

Table 2.2 Comparison between several adsorption cycles for CO2 separation process [82]. Process

CO2 feed molar fraction (%) (other gases present)

CO2 purity (%)

CO2 recovery (%)

PSA TSA TSA ESA VSA

13 (O2) 10 17 10 15

99.5 95 na 23.33 90

69 81 40 92.57 90

ESA, Electric swing adsorption; PSA, pressure swing adsorption; TSA, temperature swing adsorption; VSA, vacuum swing adsorption.

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solvent extraction process. In addition, cryogenic separation can be easy upscaled to industrial-scale utilization. The main disadvantages of this process are the requirement of a large amount of energy to provide refrigeration and CO2 solidification under low temperature [8991]. Xu et al. developed a novel CO2 cryogenic liquefaction and separation system. This process involves a two-stage compression, two-stage refrigeration, and two-stage separation [92]. The energy consumption for CO2 recovery is only 0.395 MJ/kg CO2.

2.1.6.2 Membrane separation The membrane separation method is a simple process involving a continuous, steady-state, and clean process. It is a pressure-driven process. The membrane process directly varies with increases in the CO2 concentration of the feed mixture. This technology can be managed with limited, simple, compactable equipment, and is easy to operate in scale-up processes. The energy consumption in this process of CO2 removal depends on the target purity, flue gas composition, and membrane selectivity for CO2. The postcombustion CO2 capture process in the membrane separation process requires large energy consumption. So, low partial pressure of CO2 in the flue gas is a possible disadvantage in the application of membrane separation. Membrane separation is not suitable for high flow rate applications [9395].

2.1.6.2.1 Inorganic membrane Two types of inorganic membranes, namely porous and dense, are used for CO2 separation. The top layer of the porous inorganic membrane is supported on a porous metal or ceramic support. Zeolite, silicon carbide, carbon, glass, zirconia, titania, and alumina membranes are mainly used as porous inorganic membranes supported on different substrates such as alumina, zirconic, zirconia, zeolite, or porous stainless steel [96,97]. The dense inorganic membrane (nonporous material) consists of a thin layer of metal such as palladium and its alloys (metallic membrane) or solid electrolytes such as zirconia. Another form of inorganic membrane is the liquid-immobilized membrane where the pores of the membrane are completely filled with a liquid that is selective for certain compounds.

2.1.6.3 Polymeric membrane The nonporous polymeric membranes are mainly for gases transport process, and function as solution-diffusion membrane. Polymeric membranes are made with a wide range of materials including polyacetylenes, polyaniline, polyarylene ethers, polyaryllates, polycarbonates, polyetherimides, polyethylene oxide, polyimides, polyphenylene oxides, polypyrroles, polysulfones, and amino groups such as polyethyleneimine blends and polymethymethacrylate for CO2 separation [98100].

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Selective polymeric membranes are in use in two forms, namely glassy and rubbery. The former type of polymeric membrane is more suitable than rubbery for CO2 separation due to its high gas selectivity and better mechanical properties, although robbery membranes are equal nature of high permeability like glassy types, but having low selectivity. The advantages with the polymeric membrane system are it being less expensive in the production process, its highperformance separation, simple methods of synthesis, and high potential for structural stability. The main drawback of polymeric membranes is their low thermal stability property. So, the application of these membranes for postcombustion capture is limited, and the gas must first be cooled to 313K333K for the process [101,102].

2.1.6.4 Mixed matrix membrane Mixed membrane materials also work better for CO2 separation. Zeolites, carbon molecular sieves, and many polymeric materials are suitable for mixed membrane fabrication [103106].

2.1.6.5 Hollow fiber membrane Hollow fiber membranes are a class of artificial membrane containing a semipermeable barrier in the form of a hollow fiber. This system is acceptable for most of industries for gas separation due its simplicity of operation protocol. This membrane system has an inner layer of polyvinylidene difluoride that is suitable for CO2 separation and absorption in the gasliquid membrane due to its low mass-transfer resistance and high permeability. Besides this, this system has a sufficient surface area for gasliquid interface compared to conventional gas absorption processes [107110].

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Aqueous-phase conservation and management

3

Chapter Outline 3.1 Water coverage Earth’s surface ....................................................................... 73 3.1.1 Rivers, lakes, and brackish systems ................................................73 3.1.2 Marine systems .............................................................................74 3.1.3 Water quality control .....................................................................79 3.1.4 Water pollution control regulation ...................................................96 3.1.5 Sustainable energy management from waterbodies ...........................96 3.1.6 Applications of microbial fuel cell technology ................................119 3.1.7 Hydrogen production ...................................................................123 3.1.8 Marine microalgae for carbon sequestration or sink ........................123 3.2 Conclusion ...................................................................................................127 References ..........................................................................................................130

3.1 Water coverage Earth’s surface About 71% of the Earth’s surface is covered in water from which 96.5% is made up of oceans. The remaining water is found in rivers, lakes, icecaps, and glaciers as well as in the ground as soil moisture and in aquifers (Fig. 3.1). Water is also present in the air as water vapor.

3.1.1 Rivers, lakes, and brackish systems A river system is defined as a natural flowing watercourse having larger networks of streams, lakes, and tributaries flowing towards an ocean, sea, lake, or another river by collecting water from precipitation through a drainage basin from surface runoff and other sources such as groundwater recharge, springs, and the release of stored water from natural ice and snowpacks (e.g., from glaciers). A small river can be to as referred as a stream, creek, brook, rivulet, or rill. There is no internationally acceptable generic term for river as applied to geographic features. On the basis of geographical location, a small river is known as a “run” in some parts of the United States, “burn” in Scotland and northeast England, and “beck” in north England. Table 3.1 narrates the major river systems in the world. Environmental Technology and Sustainability. DOI: https://doi.org/10.1016/B978-0-12-819103-3.00003-2 © 2020 Elsevier Inc. All rights reserved.

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FIGURE 3.1 Location of water on the earth Source: With courtesy e-education.psu.edu From https://en.wikipedia.org/wiki/Water_distribution_on_Earth#/ media/File:Earth’s_water_distribution.svg.

Rivers, lakes, and other freshwater bodies get polluted due to the input of sewage water without any treatment. Besides this, wastes from agricultural land, industrial effluent, municipal waste, and garbage containing plastic and polythene are some of the important pollutants causing uncertainty about river and lake water quality (Fig. 3.2).

3.1.2 Marine systems Over 70% of the Earth’s surface is covered by water, and most of that includes marine habitats. Marine habitats have water that contains a lot of salt. Such salted waterbodies are known as oceans, seas, or estuaries. The total water volume of Earth is about 1.386 billion km3 (333 million cubic miles), with 97.5% being salted water and 2.5% being freshwater. Of the fresh water, only 0.3% is in liquid form on the surface. On the basis of waterbody structure, an ocean is a huge continuous frame of salt water, whereas a sea is a smaller salt waterbody as compared with an ocean. A wide range of organisms including bacteria, protists, algae, plants, fungi, and animals live in the sea with variable marine habitats. The sea provides substantial supplies of food for humans, mainly fish, but also shellfish, mammals, and seaweed. Other human uses of the sea include trade, travel, mineral

Table 3.1 Major river systems in the world. Name of river

Country

Source

Tributaries

Destination

Amazon River System

Peru, Ecuador, Brazil

Rio Mantaro

Atlantic Ocean

Amur River System

Russia, China

Lake Khanka

Brahmaputra River System

China, Mongolia, Russia

Bhagirath Glacier

Chang Jiang (Yangtze) River System

China

Jari Hill

Danube River System

Germany, Austria, Slovakia, Hungary, Croatia, Serbia, Bulgaria, Romania, Moldova, Ukraine Russia, Belarus, Ukraine

Black Forest Mountain

Marañón, Â Japurá/Caquetá, Rio Negro/ Guainõa, Putumayo, Ucayali, Purús, Madeira, Tapajós, Xingu Shilka, Zeya, Bureya, Amgun, Ergune, Huma, Songhua, Ussuri Dibang River, Lohit River, Dhansiri River, Kolong River, Kameng River, Manas River, Beki River, Raidak River, Jaldhaka River, Teesta River, Subansiri River Yalong, Min, Tuo, Jialing, Han, Wu, Yuan, Zi, Xiang, Gan, Huangpu River, Teesta River, Subansiri River Black sea

Valdai hills (Russia)

Black sea

China

Kunlun Mountain

Sozh, Desna, Trubizh, Supiy, Sula, Psel, Vorskla, Samara, Konka, Bilozerka, Drut, Berezina, Prypiat, Teteriv, Irpin, Stuhna, Ros, Tiasmyn, Bazavluk, Inhulets Fen River, Tao River, Wei Rive

China, India, Pakistan

Mount Kailash

Dnieper River System

Huang Ho River (Yellow River) System Indus River System

Zanskar River, Suru River, Soan River, Jhelum River, Chenab River, Ravi River, Beas River, Sutlej River, Panjnad River, Ghaggar-Hakra River, Luni River, Shyok River, Hunza River, Gilgit River, Swat River, Kunar River, Kabul River, Kurram River, Gomal River, Zhob River

Sea of Okhotsk Andaman Sea

East China Sea

Gulf of Bohai Arabian Sea

(Continued)

Table 3.1 Continued Name of river

Country

Source

Tributaries

Destination

Irrawaddy River System Lena River System Mississippi River System

Myanmar Russia Canada, United States of America (United States) Canada

Mali River Lake Baikal Lake Itaska

Andaman sea Laptev Sea Beaufort Sea

Lasagonagma Spring

Murray River System

China, Myanmar, Laos, Thailand, Cambodia, Vietnam Australia

Chindwin, Mu, Myitnge Kirenga, Vilyuy, Vitim, Olyokma, Aldan Arkansas, Illinois, Missouri, Ohio and Red rivers Liard River, Keele River, Arctic Red River, Peel River, Great Bear River Nam Khan, Tha, Nam Ou, Mun, Tonle Sap, Kok, Ruak

Australian Alps

Southern Ocean

Madeira River System

Bolivia, Brazil

Mamore River

Mitta Mitta River, Kiewa River, Ovens River, Goulburn River, Campaspe River, Loddon River, Swampy Plains River, Murrumbidgee River, Darling River Madre de Dios River, Mamoré River, Ji-Paraná River, Dos Marmelos River, Manicoré River, Mataurá River, Mariepauá River, Aripuanã River

Nile River System

Egypt, Sudan, South Sudan, Ethiopia, Uganda, Congo, Kenya, Tanzania, Rwanda, Burundi, Eritrea Guinea, Mali, Niger, Benin, Nigeria Mongolia, China, Kazakhstan, Russia Colombia, Venezuela Argentina, Brazil, Paraguay Peru, Brazil

Blue Nile and White Nile

Mackenzie River System Mekong River System

Niger River System Irtysh River System Orinoco River System Parana River System Purus River System

Great Slave Lake

Guinea High Lands Altai Mountain Parima Mountain Parima Mountain Ucayali

Beaufort Sea South China Sea

Amazon River

Mediterranean Sea

Sokoto River, Kaduna River, Benue River, Anambra River, Bani River Tobol River, Demyanka River and the Ishim River

Gulf of Guinea Ob River Atlantic Ocean Atlantic Ocean Amazon River

Paraguay River System

Paraguay, Brazil, Argentina, Bolivia Brazil

Mato Grasso

Mato Grasso

Canastra Mountains

Atlantic Ocean

Thailand, China, Myanmar China Iraq, Turkey, Syria Russia, Kazakhstan Russia Mongolia, Russia

Tibet Plateau Tibet Turkey Ural Mountain Valdai Hills Satnovoy Range

Andaman Sea Lop Nur Shatt al-Arab Caspian Sea Caspian Sea Arctic Ocean

Yenisei River System

Mongolia, Russia

Satnovoy Range

Yukon River System

Canada, United States of America (United States)

Atlin Lake

Zaire River (Congo River) System

Democratic Republic of Congo, Gabon

Lake Mweru

Zambezi River System

Democratic Republic of Congo, Malawi, Zambia, Angola, Mozambique

Mwinlunga

Sao Francisco River System Salween River System Tarim River System Tigris River System Ural River System Volga River System Yenisei River System

Kama, Oka Angara, Lower Tunguska, Stony Tunguska River Angara, Lower Tunguska, Stony Tunguska River White River, Tanana River, Tagish River, Takhini River, Teslin River, Big Salmon River, Pelly River, Stewart River, Klondike River, Birch Creek, Koyukuk River Inkisi, Kwa-Kassai, Fimi, Kwango, Sankuru, Sangha (right), Kadei, Ubangi/(right), Mbomou, Uele, Tshuapa River (left), Lomami River (left)

Arctic Ocean Bering Sea

Atlantic Ocean

Indian Ocean

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FIGURE 3.2 River water contaminated by garbage consisting of plastic and polythene.

FIGURE 3.3 Costal area of seashore contaminated with plastic debris, polythene bags, and other household waste materials.

extraction, power generation, warfare, and many other casual activities for human entertainment. Eighty percent of marine pollution comes from land. Air pollution is also a contributing factor as it carries pesticides or dirt into the ocean. Like rivers and lakes, marine systems are also contaminated by a variety of pollutants resulting from the activity of human beings. Major sources of marine pollution are the inflow of chemicals, solid waste, and discharge of radioactive elements, industrial and agricultural effluents, and the practice of sewage water disposal, plastic material disposal, and oil spills (Fig. 3.3). So, the tools, techniques and instruments, those are applicable for controlling contaminated water bodies are also applicable to control marine pollution.

3.1 Water coverage Earth’s surface

3.1.3 Water quality control Industry is a major source of water pollution, causing uncertainty regarding rivers, lakes, and oceans. Unfortunately, many industries try to use freshwater to wash away waste from their plants into rivers, lakes, aquifers, and oceans. Such practices should be stopped at government level by strictly implementing water regulatory legal action. A few important environmental instruments are discussed. Changes in the values of water quality parameters of rivers with the input of different types of pollutants cause uncertainty regarding river systems. Water pollutants include a variety of industrial effluents containing health-hazardous organic and inorganic wastes, untreated municipal sewage, insecticide and pesticides used in agricultural practices, and waste from livestock operations (Table 3.2). Besides this, dust, volcanic gases, and natural gases in the air such as carbon dioxide and oxides of nitrogen and sulfur get entrapped in rain water and become an ultimate source of water pollution. In general, the water quality of rivers and lakes changes with the seasons and geographic locations. There is no single measure that constitutes good water quality. For instant, drinking water can be used for industrial purposes, but water used in industry cannot be used for drinking. “Prevention is better than cure” is a common phrase used to emphasize the advantages of taking preventive measures to control any bad output. Remedial actions to clean up polluted sites and waterbodies are generally more expensive than controlling pollutants at their generation sites. Industries are major sources of pollutants bringing instability to river systems. Before releasing industrial wastewater into natural water sources (rivers, lakes, and aquifers) it can be treated chemically, mechanically, or biologically to remove toxic impurities and also to increase biological oxygen demand (BOD).

3.1.3.1 Brine treatment Brine treatment is a tool used to remove dissolved salt ions from wastewater, seawater, or brackish water. Industrial brine water contains dissolved ions such as hardness ions or other metals other than salt ions. So, it needs special treatment processes and equipment. Industrial brine water treatment involves reducing the final volume of water discharged or maximizing the recovery of freshwater or salt. Besides this, industrial brine water treatment is managed with minimum expenses of electricity, chemicals, and physical footprint. Mostly, membrane filtration processes such as reverse osmosis, ion-exchange processes such as electrodialysis, weak acid cation exchange, or evaporation processes such as brine concentration and crystallization through mechanical vapor recompression and steam are used for brine water treatment. Generally, reverse osmosis is not suitable due to fouling caused by hardness salts, organic contamination, or damage to the reverse osmosis membrane from hydrocarbons. The industrial brine water treatment process mainly depends on the type of industry and manufacturing process (Fig. 3.4A
C).

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Table 3.2 Sources of industrial wastewater. Types of industry

Nature of pollutants

Battery manufacturing Battery manufacturers specialize in fabricating small devices for electronics and portable equipment (e.g., power tools), or larger, high-powered units for cars, trucks, and other motorized vehicles. Food processing plans

Pollutants generated at manufacturing plants include cadmium, chromium, cobalt, copper, cyanide, iron, lead, manganese, mercury, nickel, oil and grease, silver, and zinc [1].

Iron and steel industry

Mines and quarries

Electric power plants

Organic chemicals manufacturing The specific pollutants discharged by organic chemical manufacturers vary widely from plant to plant depending on the types of products manufactured such as bulk organic chemicals, resins, pesticides, plastics, or synthetic fibers. Nuclear industry

Food processing industry

The constituents of food and agriculture wastewater are often complex to predict due to the differences in BOD and pH in effluents from vegetable, fruit, and meat products and due to the seasonal nature of food processing and postharvesting. High BOD Contamination of waste streams includes gasification products such as benzene, naphthalene, anthracene, cyanide, ammonia, phenols, cresol and complex organic compounds known collectively as polycyclic aromatic hydrocarbon [6]. Wastewater from metal mines and ore recovery plants are inevitably contaminated by the minerals present in the native rock formations. Following crushing and extraction of the desirable materials, undesirable materials may enter the wastewater stream. For metal mines, this can include unwanted metals such as zinc and other materials such as arsenic. Many of these plants discharge wastewater with significant levels of metals such as lead, mercury, cadmium, and chromium. Wastewater streams include flue-gas from desulfurization and fly ash. Some of the organic compounds that may be discharged are benzene, chloroform, naphthalene, phenol, toluene, and vinyl chloride, and high BOD.

The waste production from the nuclear and radiochemicals industry is dealt with as radioactive waste Processing food for sale produces wastes generated from cooking that are often rich in plant organic material and may also contain salt, flavorings, coloring material, and acids or alkali. Significant quantities of oil or fats may also be present. (Continued)

3.1 Water coverage Earth’s surface

Table 3.2 Continued Types of industry

Nature of pollutants

Iron and steel processing

Contamination of waste streams includes gasification products such as benzene, naphthalene, anthracene, cyanide, ammonia, phenol, cresol, together with a range of more complex organic compounds known collectively as polycyclic aromatic hydrocarbons [6]. Pollutants discharged at petroleum refineries and petrochemical plants include BOD, oil and grease, suspended ammonia, chromium, phenols, and sulfides [10]. Wastewater from metal mines and ore recovery plants are inevitably contaminated by the minerals present in the native rock formations. Following crushing and extraction of the desirable materials, undesirable materials may enter the wastewater stream. For metal mines, this can include unwanted metals such as zinc and other materials such as arsenic. Effluent from the pulp and paper industry is generally high in suspended solids and BOD. Plants that are bleached for wood pulp for paper making may generate chloroform, dioxins (including 2,3,7,8TCDD), furans, phenols, and chemical oxygen demand (COD), high BOD, and dissolved solids. Textile dyeing plants generate wastewater that contain synthetic and natural dyestuff, gum thickener (guar) and various wetting agents, pH buffers, and dye retardants or accelerators. Industrial applications where oil enters wastewater streams may include vehicle wash bays, workshops, fuel storage depots, transport hubs, and power generation. Often the wastewater is discharged into local sewer or trade waste systems and must meet local environmental specifications. Typical contaminants can include solvents, detergents, grit, lubricants, and hydrocarbons. Many water treatment techniques produce organic and mineral sludges from filtration and sedimentation as well as residual calcium and magnesium carbonate ions from ion exchange units.

Petroleum refineries

Mines and quarries

Pulp and paper industry

Textile dying

Industrial oil contamination

Water treatment Industries need high water for pure chemical synthesis or boiler feed water

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FIGURE 3.4 (A) Schematic diagram for coal mine wastewater treatment process, (B) Wastewater from Coppermine

3.1.3.2 Solid removal technology Generally, sedimentation methods are used for solid recovering as a slurry or sludge. But, for the fine solid contaminated water, the sedimentation process is followed by simple filtration or ultra filtration. The presence of any colloids can be removed by a flocculation process in the form of floc or flakes. Mostly, iron (II) sulfate (FeSO4), aluminum sulfate (Al2(SO4)3), and iron(III) chloride (FeCl3)

3.1 Water coverage Earth’s surface

FIGURE 3.4 (Continued)

are used as coagulating agents. Generally, the food processing industry uses alum salt or the addition of polyelectrolytes. A specific operation practice is carried out on the basis of the type of wastewater produced and the type of treatment required. Generally, primary sedimentation (clarification), dissolved air floatation, belt filtration, and drum screening methods are used in the solid waste removal process.

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Sources of oil Natural seeps Offshore drilling Up in smoke Down the drain routine Maintenance Big spills 0

50

100 150 200 250 Volume (thousands of tons)

300

FIGURE 3.5 Different sources of waste oil in waterbodies on Earth’s surface. With courtesy oil spills- safe drinking water, www.safewater.rg.

3.1.3.3 Removal of oil spills and grease from contaminated water Oil spills are not the main cause of pollution in waterbodies, but other sources of oil pollution collectively discharge more oil into waterbodies than major spills do (Fig. 3.5). The input of oil into waterbodies varies from country to country. However, the exact amount of oil pollution varies (Table 3.3) between 470,000 and 8.4 million tons, depending on the frequency and intensity of oil spills. Water bodies from the bottom of the ocean and from eroding sedimentary rocks also contribute oil into the ocean. For example, on the California coast, several kilometers of coastline release between 7500 and 11,400 L of crude oil each day. More than 200 natural underwater oil seeps have been located globally including off the east coast of Canada near Labrador and off the north coast of Baffin Island. The US Environmental Protection Agency (US EPA) reports that on average there are about 70 cases per day. Due to their small structure, they are not supposed to be harmful. But big spills also occur and do tremendous harm to natural waterbodies. Besides oil spills, greenhouse gas emissions and emissions from vehicles and industries carry hundreds of tons of hydrocarbons. Even burning of oil spill in the ocean emits hydrocarbons. Mostly, hydrocarbons contain the oxides of sulfur and nitrogen, which mix with atmospheric water vapor and are condensed, thus, creating acid rain. Acid rain has tremendous harmful impacts on natural ecosystems, and can even wear away buildings and natural monuments. During the transfer of oil through various logistics systems, there is a risk of oil spills (Fig. 3.6) [1,2,3]. Mostly ocean tankers carrying huge amounts of crude oil, pipelines carrying crude oil and petrol, and trains and tanker trucks, face the risk of accidental oil spills. As the number of transfers increases, so does the risk of the oil spilling. Table 3.4 shows the regions with the greatest number of oil spills since 1960.

Table 3.3 Important oil spill accidents from oil tanker occurred in different locations around the world. Spill/tanker

Location

Date

Taylor Energy

United States, Gulf of Mexico

Nowruz Field Platform Lakeview Gusher Kuwaiti Oil Lakesb

Iran, Persian Gulf Kern County, California, United States Kuwait

Kuwaiti Oil Fires[dubious

Kuwait

Ixtoc I

Mexico, Gulf of Mexico

Gulf War oil spilld

Kuwait, Iraq, and the Persian Gulf Uzbekistan United States, Gulf of Mexico

September 23, 2004
Present February 4, 1983 March 14, 1910
September 1911 January 1991
November 1991 January 16, 1991
November 6, 1991 June 3, 1979
March 23, 1980 January 19, 1991
January 28, 1991 March 2, 1992 April 20, 2010
July 15, 2010 August 6, 1983 July 19, 1979


discuss]c

Fergana Valley Deepwater Horizon Castillo de Bellver Atlantic Empress/ Aegean Captain Amoco Cadiz ABT Summer

South Africa, Saldanha Bay Trinidad and Tobago France, Brittany Angola, 700 nmi (1300 km; 810 mi) offshore

March 16, 1978 May 28, 1991

Tons of crude oil (thousands)a

Barrels (thousands)

US gallons (thousands)

210
490

1500
3500

63,000
147,000

260 1200

1900 9000

80,000 378,000

3409
6818

25,000
50,000

1,050,000
2,100,000

136,000

1,000,000

42,000,000

454
480

3329
3520

139,818
147,840

818
1091

6000
8000

252,000
336,000

285 560
585

2090 4100
4900

87,780 172,000
180,800

252 287

1848 2105

77,616 88,396

223 260

1635 1907

68,684 80,080

a One metric ton (tonne) of crude oil is roughly equal to 308 US gallons or 7.33 barrels approx.; 1 oil barrel (bbl) is equal to 35 imperial or 42 US gallons. Approximate conversion factors. Archived 2014-06-21 at the Wayback Machine. b Oil spilled from sabotaged fields in Kuwait during the 1991 Persian Gulf War pooled in approximately 300 oil lakes, estimated by the Kuwaiti Oil Minister to contain approximately 25,000,000 to 50,000,000 barrels (7,900,000 m3) of oil. According to the US Geological Survey, this figure does not include the amount of oil absorbed by the ground, forming a layer of “tarcrete” over approximately 5% of the surface of Kuwait, 50 times the area occupied by the oil lakes [8]. c Estimates for the amount of oil burned in the Kuwaiti Oil Fires range from 500,000,000 barrels (79,000,000 m3) to nearly 2,000,000,000 barrels (320,000,000 m3). Between 605 and 732 wells were set ablaze, while many others were severely damaged and gushed uncontrolled for several months. It took over 10 months to bring all of the wells under control. The fires alone were estimated to consume approximately 6,000,000 barrels (950,000 m3) of oil per day at their peak. d Estimates for the Gulf War oil spill range from 4,000,000 to 11,000,000 barrels (1,700,000 m3). The figure of 6,000,000 to 8,000,000 barrels (1,300,000 m3) is the range adopted by the US Environmental Protection Agency and the United Nations in the immediate aftermath of the war, 1991
93, and is still current, as cited by NOAA and The New York Times in 2010 [1]. This amount only includes oil discharged directly into the Persian Gulf by the retreating Iraqi forces from January 19 to 28, 1991. However, according to the UN report, oil from other sources not included in the official estimates continued to pour into the Persian Gulf through June, 1991. The amount of this oil was estimated to be at least several hundred thousand barrels, and may have been factored into the estimates above 8,000,000 barrels (1,300,000 m3).

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FIGURE 3.6 Release of oil to water surface from different sources.

Table 3.4 Regions of the world with the most oil pollution. Region

Number of spills since 1960

Gulf of Mexico Northeastern United States Mediterranean Sea Persian Gulf Southern North Sea

267 140 127 108 75

With courtesy National Oceanic and Atmospheric Administration Office of Response and Restoration.

3.1 Water coverage Earth’s surface

3.1.3.3.1 How oil spills interact with waterbodies Since oil is less dense than water, after mixing with water it gets spread on the surface of the water. Lighter oils like gasoline spread faster than the heavy crude oil. Besides this, physical factors like water current, temperature, and wind flow accelerate oil spill movement. Over time, the oil settles at the bottom of the water when the oil density ranges from 0.85 to 1.04 g/cm3. Ocean water has a density between 1.02 and 1.03 g/cm3 depending on the salt concentration. So, heavy oil with a density of 1.01 g/cm3 would float on surface of ocean water, whereas it would sink in a river. Natural bacteria present in oceans or rivers eat oil and digest the carbohydrate. Gasoline like short chain hydrocarbon compounds having short life span dissociate in ocean water within few hours. Under natural condition the hydrocarbon component of oil spill gets break with the interaction of ambient oxygen.

3.1.3.3.2 Damage caused by oil spills Oil spills entirely damage the fauna and flora of waterbodies in an uncontrolled manner. Oil spills act as a blanket on water surfaces and do not allow oxygen inside the waterbodies. Deficiency of oxygen threatens the life of aquatic plants and animals. The feathers of marine birds get coated with oil and this arrests their free movement and is ultimately responsible for their deaths (Fig. 3.7). Many birds and animals also ingest oil when they clean themselves, which can poison them. Mass casualty of marine fish populations not only bring imbalance in the marine ecosystems, but also threaten food security.

3.1.3.3.3 Bacteria and archaea for oil spill remediation Both aquatic and soil systems have diversified microbes that feed on petroleum hydrocarbons and release carbon dioxide (Fig. 3.8). A variety of bacteria and archaea, fungi, algae, and cyanobacteria are involved in the hydrocarbon degradation process [4
7].

FIGURE 3.7 A bird covered in the Gulf of Mexico oil spill, June 6, 2010. With courtesy from https://www.flickr.com/photos/lagohsep/4666755541.

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FIGURE 3.8 Mechanism of microbial degradation of hydrocarbon from oil and the formation of carbon dioxide.

There have been continuous challenges to face in the threat of oil spills contamination, especially in extreme geographical locations such as polar regions, deep sea areas, deserts, and wetlands. Over the past few decades, a lot of advanced studies on hydrocarbon degradation by bacteria have been reported. Petroleum hydrocarbon-degrading bacteria as a novel finding of scientists can be used in commercial models for the remediation of oil-spill-contaminated waterbodies [8
10,12]. More than 79 genera of hydrocarbon-consuming bacteria including Achromobacter, Acinetobacter, Alteromonas, Burkholderia, Dietzia, Enterobacter, Kocuria, Marinobacterium, Pandoraea, Psedomonas, Stapphylococcus, Streptobacillus, and Streptococcus have been discovered [1,8,11
17]. Currently, the application of bacterial systems has been an attractive model for mass scale bioremediation of oil spills [18
23]. Interestingly, some obligate hydrocarbon clastic bacteria like Alcanivorax, Marinobacter, Thallassolituus, Cycloclasticus, Oleispira that are either untraceable or have low density distribution patterns are noticed to be abundant after oil spills [24]. There are some bacteria that have broad-spectrum petroleum hydrocarbon degradation capability. For example, Dietzia sp. DQ 12-45-1b utilizes n-alkanes (C6
C40) as sole carbon sources [25] and Achromobacter xylosoxidans DNO 02 has the potential to consume monoaromatic and polyaromatic hydrocarbons [26]. The bacterial degradation process varies from microbe to microbe and the condition of the geographical location. This could be due to the variation of metabolic activity within bacterial species or genera [1,27]. Mostly, the overall

3.1 Water coverage Earth’s surface

petroleum hydrocarbon degradation in natural conditions is mainly dependent on the resultant action of a consortium of bacteria rather than any individual one [22]. For example, the bacteria consortium developed by Varjani et al. (2015) was formulated by a halotolerant hydrocarbon utilizing bacterial consortium consisting of Ochrobactrum sp., Stenotrophomonas maltophilia, and Pseudomonas aeruginosa that work well in the degradation of crude oil (about 83.49%) [16].

3.1.3.3.4 Hydrocarbon-degrading fungi Microorganisms, specially fungi, have a higher tolerance to the toxicity of hydrocarbons due to their physiology and adaptation to such variations in the environment, and they also have the mechanism for the elimination of spilled oil from the environment [28,29]. The most common fungi that have been recorded as biodegradable belong to the genera of Alternaria, Aspergillus, Candida,

FIGURE 3.9 Showing a model on how cyanobacteria synthesize alkane, and is subsequently degraded by bacteria. Adapted from Proc Natl Acad Sci USA.

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Cephalosporium, Cladosporium, Fusarium, Geotrichum, Gaocladium, Mucor, Paecilomyces, Penicillium, Pleurotus, Polyporus, Rizopus, Rhodotolura, Saccharomyces, Talaromuces, and Torulopsis [30
39]. Oil spill degrading algae and cyanobacteria. Algae and cyanobacteria have the potential to degrade petroleum hydrocarbon. Interestingly, it has been noticed that some cyanobacteria can synthesize alkanes like hydrocarbon and the same is consumed by hydrocarbon-degrading bacteria as a source of energy [40] (Fig. 3.9). On the basis of the abundant availability of the cyanobacteria genera, Prochiorococcus and Synnechococcus, in oceans, the global production of hydrocarbon is supposed to be about 800 million tons yearly, whereas in comparison, the United States produced about 700 million tons of petroleum and other hydrocarbon liquids in 2014. Cyanobacteria mainly produce straight-chain hydrocarbons like pentadecane, heptadecane, and 8-heptadecene. The overall mechanism of oil spill degradation by microorganisms mainly depends on the physicochemical nature of the oil spill and the status of the waterbody (mostly the availability of oxygen). Microbes take longer to degrade highmolecular-weight hydrocarbons such as polycyclic aromatic hydrocarbons as compared to short-chain hydrocarbon. Generally, microbes consist of a wide array of enzymes for the breakdown of petroleum hydrocarbons. In general, alkanes (hydrocarbons containing double bonds) and short-chain alkanes (hydrocarbons containing single bonds) are the most easily degraded followed by branched alkanes (alkanes with side chins) and then aromatic (hydrocarbons in a stable ring structure). However, degradation rates vary based on environmental parameters and decrease as hydrocarbon complexity increases. The action of microbes on hydrocarbons is a sequential process: Linear alkanes

Branched Alkanes

Small aromatic compounds

Cyclic Alkanes

3.1.3.3.5 Mechanisms of oil spill bioremediation The most effective way of microbial degradation of petroleum hydrocarbons is mainly dependent on the aerobic condition of the prevailing area of the oil spill

3.1 Water coverage Earth’s surface

FIGURE 3.10 Microbial degradation of hydrocarbon in aquatic environment.

(Fig. 3.10). The initial stage of the biodegradation process is an oxidative process of crude oil or petroleum hydrocarbon. In this process, exogenous oxygen incorporates the hydrocarbon molecule. It is an enzymatic process where oxygenases and peroxidases are involved and responsible for the peripheral degradation pathways that convert petroleum hydrocarbons in a sequential manner of multiple intermediates, for example, the tricarboxylic cycle. The various components of the tricarboxylic acid cycle like acetyl-CoA, succinate, and pyruvate help in the overall biomass formation process. Sugars required for various biosynthesis and growth stages are synthesized by gluconeogenesis. Besides this, the attachment of microbial cells to substrates and the production of biosurfactants on the cell surface have been well studied [42,43]. Cytochrome P450 (CYP) alkane hydroxylase belongs to the super family of ubiquitous heme-thiolate monooxygenases and plays a critical role in the microbial degradation of petroleum hydrocarbon, chlorinated hydrocarbons, fuel additives, and many other compounds [44].

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The process of the incorporation of oxygen within the peripheral groups of hydrocarbon substrate depends on the nature of the enzyme systems. CYP enzymes have been identified in all kingdoms of life, namely animals, plants, fungi, protists, bacteria, archaea, and even viruses. More than 50,000 distinct CYP proteins are known. CYP are terminal oxidase enzymes in electron transfer chains and are broadly categorized as P450-containg systems. CYP enzyme systems are involved in the biodegradation of petroleum hydrocarbons. Several yeast species (Candida maltose, Candida tropicalis, and Candida apicola) have the potential to degrade n-alkanes and other aliphatic hydrocarbons as a source of carbon and energy through multiple microsomal CYP forms. Having biosurfactants in microbes is a short of defense mechanism by which solubilization and removal of contaminants [45,46] are carried out through a variety of microorganisms [47
53]. Mostly, biosurfactants are glycolipid types of molecules can act as emulsifying agents by decreasing the surface tension and forming micelles. Anaerobic hydrocarbon degradation is a slower process as compared to aerobic hydrocarbon degradation. Facultative and obligatory anaerobic bacteria and archaea are known to degrade hydrocarbons without oxygen. The initial steps in anaerobic hydrocarbon degradation involve the addition of oxidized functional groups to activate the hydrocarbon molecules. Anaerobic biodegradation may take anywhere between a few days to a few months. Despite the slow degradation process, the complete degradation of many different types of hydrocarbon can occur. Under anaerobic conditions, microbes use terminal electron acceptors like nitrate, sulfate, carbon dioxide, and oxidized metals, rather than oxygen for respiration.

3.1.3.4 Sewage wastewater treatment Sewage is generated by residential, institutional, commercial, and industrial establishments. So, sewage wastewater is an undefined quality of water consisting of a variety of pollutants in different states and including solid wastes, suspended organic materials, dissolved toxic elements, oil residues, and a variety of pathogenic bacteria, fungi, algae, and viruses. The entire sewage water treatment covers three stages, namely primary, secondary, and tertiary treatment (Fig. 3.11).

3.1.3.4.1 Primary treatment The primary treatment process involves the removal of a variety of solid wastes. In the first phase, the sewage water is passed through a bar screen to filter out solids and large objects. The isolated solids consist of waste plastic, polythene, paper wastes, and organic materials. The nondegradable items are recycled by proper chemical treatment, and degradable organic wastes are sent to landfills. Suspended fats and greases are removed before the primary treatment of sewage. The leftover sewage water after the removal of solid materials is known as effluent and is subjected to settlement in small ponds. The residual, semisolid material obtained at the bottom of the settlement tank/pond is known as sludge.

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FIGURE 3.11 Sequential stages of wastewater treatment before releasing into natural environment. Source: Encyclopaedia Britannica Inc., 2012. From https://en.wikipedia.org/wiki/Sewage_treatment#/media/ File:ESQUEMPEQUE-EN.jpg

This sludge is a byproduct and can be used as biofertilizer. The treatment and disposal of sewage sludge are important factors in the primary treatment process. Before disposal into nature, the volume of the sludge is reduced and the organic materials in the sludge are brought to a stabilized state. The stabilized sludge is odorless and not harmful during handling.

3.1.3.4.2 Secondary treatment of sewage water The secondary treatment process is mainly for the removal of settleable solids, and includes a biological process to remove dissolved and suspended organic compounds. It is traditionally applied to the liquid portion of sewage after primary treatment. Mostly, indigenous aquatic aerobic microbes are used for the bioremediation of sewage water. Short-chain carbon molecules, sugars, fats, food wastes, soap, and other organic compounds are used as a source of energy for the bacteria and protozoa. Temperatures ranging from 0 C to 40 C are suitable for biological degradation processes. As stated by the US EPA, secondary treated sewage is supposed to produce effluent with a monthly average of less than 30 mg/BOD and less than 30 mg/L suspended solids. A sewage treatment plant should remove at least 85% of the BOD and suspended solids from domestic sewage.

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3.1.3.4.3 Tertiary treatment Tertiary treatment is a process for further cleaning effluent obtained from the secondary treatment process to ensure the minimization of nutrients like nitrate and phosphorus and other inorganic compounds. In addition, harmful bacteria, viruses, and parasites are killed by specific chemical treatments before it is reused, recycled, or discharged into the environment. Nitrogen can be removed from wastewater by natural processes in wetlands, but also via microbial denitrification. Ozone treatment is most effective for wastewater cleaning. The latest and most promising treatment technology is the use aerobic granulation. Alum is used for the removal of phosphorus particles and groups the remaining solids together for their easy removal through a filtration process. But the use of alum leads to the formation of tiny particle clusters known as flocs. For further cleaning, the wastewater is flushed through sand filter to block floc. The sand filters are backwashed every 24 hours to remove the floc accumulated on sand filter surface. Chlorination is a common practice for killing bacteria, viruses, and parasites.

3.1.3.5 Removal of biodegradable organic wastes Generally, the active sludge or trickling filter techniques (Fig. 3.12) are used to remove biodegradable organic wastes. These two techniques are also used in sewage treatment processes. The former technique is based on biochemical reactions. Air and selected microbes are injected into wastewater for biological oxidation. The resulting sludge produced through such a process is condensed and used as fertilizer. In the latter case, the trickling filter has a bed of rock, gravel, slag, peat moss, or plastic media over which wastewater is passed. The provision of a slime layer of specific microbes is provided for the biological oxidation of pollutants. Air or oxygen is injected to maintain the aerobic condition inside the chamber. In such a process, organic pollutants present in the wastewater are adsorbed onto the surface of the slime layer of the microbes. The aerobic condition of the chamber provides oxygen for the biochemical oxidation of the organic compounds. The products resulting from such a process are carbon dioxide, water, and other products of oxidation (Fig. 3.13). The trickling filter is also known as a trickling biofilter, biofilter or biological filter, or biological trickling filter.

3.1.3.6 Removal of other organic materials from wastewater Synthetic organic materials like various types of solvents, paints, expired pharmaceuticals, pesticides, etc., are problematic in degradation. However, advanced oxidation processing, distillation, adsorption, ozonation, vitrification, incineration, and landfill disposal methods are used on the basis of geographical location and surrounding environmental conditions.

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FIGURE 3.12 Schematic diagram of activated sludge process.

Waste water

Microbial slime layer

Air CO2 Other oxidixed products

Anaerobic

Aerobic

Organics Bed media

Treated water

FIGURE 3.13 A schematic cross section of the contact face of the bed media in a trickling filter. Adapted from Wikipedia, Industrial wastewater treatment, 2019.

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3.1.4 Water pollution control regulation For sustainable water resource management, well-planned policy framing and effective implementation are of utmost importance to save life from a variety of water-borne diseases and to make water drinkable. Water pollution control policies should be on a “command-and-control” regulation basis. The basic target of a regulatory act is to have control over the quality of pollutants from the point of origin. Water pollution control “Regulatory Acts” vary according to country. There may be also legal issues locally and regionally within a country or internationally, if they relate to transboundary water sources such as rivers, seas, or aquifers. Water control regulations should determine allowable emission standards for specific industry units or companies. Environmental economists argue that command-and-control regulation can be operated through economic instruments such as taxes, charges, and tradable pollution rights. Under tradable pollution rights, a company is given permission for the legal right to discharge a limited amount of pollutants for a certain period only. If a company pollutes less, then they have the option to sell their leftover pollution permits to another firm that generates more pollutants. But the main disadvantage of this pollution controlling instrument is the nature of cost, where one company may manage with minimum budgetary provisions while it would be a financial burden for another company to develop pollution controlling facilities. Consequently, tradable pollution permits can be a cost-effective way to achieve a reduction in overall pollution. Environmental economists say that command-and-control regulation will be plausible while exercising economic instruments such as taxes, charges, and tradable pollution rights. Besides this, on the basis of the “polluter pays principle” (PPP), a polluter is supposed to bear the expense of preventing, controlling, and cleaning up pollution. In 1972, the Organisation for Economic Co-operation and Development (OECD) adopted the principle of PPP, and in 1989, indicated that it should be applied to agriculture. Later, in 1990, it was recognized internationally as a legal principle. Currently, the PPP plays an important role in national and international environmental policy. In 1992, the Rio Declaration accepted PPP as a major instrumental factor to control pollution. Prior to this, the European Community (EC), in 1987, accepted it for pollution control.

3.1.5 Sustainable energy management from waterbodies Harnessing the potential of marine water systems, rivers, lakes, and even contaminated waterbodies and generating sustainable energy to support life as well as for the functioning of the many production and consumption processes are primary requirements for life. The total energy consumption has increased to six times what it was in 1950, and is projected to grow by as much as 55% by 2050. So, it is necessary to exploit the most possible methods to utilize any form of waterbody, even highly polluted aquatic ecosystems to produce sustainable forms of energy.

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3.1.5.1 Microbial fuel cell technology for energy from wastewater Microbial fuel cell (MFC) technology is an emerging green energy technology due to its mild operating conditions and variety of applications such as wastewater purification, desalinization of seawater, remote sensing, hydrogen generation, etc. It is also used in the biodegradation of organic wastes. Some microbes have high potentials to produce electricity or hydrogen by utilizing biological wastes. These microbes can be well explored as fuel cells due to their biological potential for generating electrons through metabolic activity. These biologically generated electrons pass through an electron carrier chain onto an electrode surface and generate electricity while producing a proton motive force for ATP generation (Fig. 3.14). Gram-positive bacteria have the ability to produce extracellular electrons without possessing any outer membrane. MFC technology is based on such mysterious biological activity and needs further investigation in the light of modern knowledge on biophysics. The most interesting and encouraging fact of MFCs is that they are capable of converting biological wastes into degradable form and also of

External circuit Electrons e–

e–

Incoming fuel wastewater

Bacteria

Electrons Incoming oxygen

H+ Protons Outgoing carbon dioxide

Outgoing water Wastewater Anode

Cathode PEM or salt bridge

FIGURE 3.14 A typical microbial fuel cell having four parts. The first part is the anode associated with bacteria and surrounded with a wastewater or glucose solution. The second part is the cathode in an oxygen environment, the third part is the proton exchange membrane (PEM) or salt bridge, and the fourth part is the external circuit. The bacterium on the anode produces hydrogen protons and hydrogen electrons as a result of oxidation. The hydrogen electrons pass through the external circuit and enter the cathode. Hydrogen protons pass through the salt bridge and enter the cathode. The hydrogen electrons and protons combine with oxygen to produce water.

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generating power in terms of electricity and hydrogen without any harmful environment issues. The anode of microbial fuel cell (MFC) receives electrons from microbes present in soil or aquatic system. This process represents the strategy of link between microbiology and electrochemistry, and focuses on the phenomenon of bio-film ecology. The function of MFC technology is mainly dependent on biological oxidation and reduction processes based on electron transfer principles. Typical electrode reactions are shown in the following equations using acetate as an example substrate: Microbe

Anodic reaction: CH3 COOH 1 2H2
! 2CO 1 8H1 1 8e2

(3.1)

Cathodic reaction: 8H 8e2 1 2O2 -4H2

(3.2)

Microbe

Overall reaction: CH3 COOH 1 2O2
! H2 O 1 2CO2

(3.3)

Mostly, in bacterial systems, oxygen acts as an electron acceptor. But in the absence of oxygen none of this electron transfer can occur. Microbes have the potential to use substrate molecules in waste streams in the absence of oxygen, but the amount of energy received is greatly reduced and growth under these conditions is limited. In MFCs, bacteria transfer their electrons to the electrode, which is joined by wire to a second electrode in an oxygen containing environment, and is ultimately responsible for the electricity to power an electronic device. Generally, biological substrates are burned to generate heat energy, which turns water into steam for the purpose of power generation to create electricity, but this is an inefficient practice for adequate energy generation. Bacteria are biocatalysts that use biological waste components such as proteins, fats, and carbohydrates and generate electrons through metabolic activity, which are ultimately used by the cells for energy. In this process, oxygen acts as the driving force due to its high affinity for electron transfer. In the past two decades, high rate anaerobic processes have found increasing application for the treatment of domestic as well as industrial wastewaters. The major advantages these systems offer over conventional aerobic treatment are the no-energy requirement for oxygen supply, less sludge production, and the recovery of methane gas. In brief, MFC microorganisms interact with electrodes using electrons, which are either removed or supplied through an electrical circuit to generate electricity. The past few decades have witnessed the significance of bioelectrochemical systems for the design and development of high efficiency MFCs for commercialization. The MFC technology is emerging as a novel practice to resolve the energy crisis and environmental pollution for the present and future generations. Owing to its strong compliances with sustainable development goals and its safety, it is seen as a promising substitution for current polluting technologies. The MFC would be immensely helpful in resolving issues of energy crises and aquatic resource contamination with hazardous biological materials. Presently, MFC operation is supposed to be at pilot-scale level and under the process of development toward commercialization significant technical challenges

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are involved. In order to bridge the gap between laboratory demonstration and commercialization, new MFC startup projects must first be initiated to obtain a blueprint to convince potential adopters of this technology for further trial. The MFC, otherwise known as a biological fuel cell, generates electricity by utilizing electrons resulting from the oxidation and reduction of bacterial respiration. The MFC is a wonderful system in which the microbial catalysis process facilitates the movement of electrons throughout the system, instead of the traditional chemically catalyzed oxidation of a fuel cell at the anode and reduction at the cathode. The performance of an MFC is accompanied by three steps while generating direct electricity. In the first stage of metabolism, glucose is converted by glycolysis into two molecules of pyruvate, during which ATP and NADH are produced. This occurs in the cytosol of the cell. In the second stage, the pyruvate molecules are catalyzed in the mitochondria to CO2 and acetyl-CoA. This mostly occurs in animal cells. Subsequently, acetyl-CoA is transferred to oxaloacetate, which participates in the Krebs cycle, and results in the production of CO2 and NADH. Molecular oxygen is an essential part of the generation of NAD1 and ensures the continuation of the Krebs cycle. In the case of the membrane-bound electron transport chain, NADH passes its high energy electrons to O2, which later produces water. Lastly, in the third phase, membrane-bound oxidative phosphorylation occurs when glucose is catabolized to generate energy. In eukaryotic cells, the process occurs within the mitochondrial membrane, while in prokaryotes, it occurs in the cellular membrane. It is also referred to as the electron transport chain. The process involves the transfer of electrons between electron carriers in order to reduce their potential. As the electrons move toward the terminal oxidizing agent, protons are pumped across the membrane (from the inside to the outside) creating a transmembrane proton concentration gradient. As protons move back across the membrane, ADP is phosphorylated to form ATP. Electron carriers include NADH, FADH2, and QH2, which are coenzymes that reduce O2. Electrons are transferred to the anode by electron mediators or shuttles (Fig. 3.15) [54,55], by direct membrane associated electron transfer [8], or by so-called nanowires [55
58] produced by the bacteria, or perhaps by other as yet undiscovered means. Neutral red (NR) and anthraquinone-2,5 are most commonly used as electron carriers to the anode [59,60]. When an MFC works without any mediator it is known as a “mediator-less” MFC [61] like used for supplying. Like any electrochemical cell, an MFC requires an anode wired to a cathode to facilitate the flow of electrons to the cathode and an electrolytic medium to allow positive ions to diffuse to the cathode. But unlike a purely chemical electrical cell, there is no metal catalyst required at the anode. Instead, in an MFC, the anode is exposed to a culture of electrogenic bacteria, which obtain electrons from organic molecules. These bacteria use the anode as an external terminal electron acceptor, as the electrons transferred ultimately travel to the cathode

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FIGURE 3.15 Electron transfer mechanisms from microorganisms to the anode in microbial fuel cells. (A) Indirect electron transfer via redox mediators and primary metabolites such as H2, and (B) direct electron transfer via outer-membrane cytochromes, proteins or enzymes, and conductive pili such as nanowires. With courtesy from Klaus Wandelt et al., 2017, Atlas R. Microbial hydrocarbon degradation-bioremediation of oil spills. J Chem Technol Biotechnol 1991;52:149
56.

where they reduce oxygen. Since the most inexpensive and abundant sources of carbon available are often industrial wastewaters, MFCs have great potential for improving the efficiency of the bioremediation of industrial wastes by allowing energy to be recovered during effluent processing. Electrons generated by the metabolic activity of microbes utilizing organic substrates are directly or indirectly transferred onto the anode surface. In the former case, microbes are directly attached onto the anode by forming a microfilm, and, thus, supply electrons generated through the outer membrane to the anode. In some cases, microbes are attached onto the anode surface through nanowires (pili) [62
67]. Indirect electron transfer occurs through external or internal mediators [62,68
75]. Several external mediators have been used in MFCs such as methylene blue (MB), methyl red, methyl yellow, methyl orange, bromocresol purple, bromocresol green, bromothymol blue, Congo red, cresol red, Eriochrome black T, murexide, NR, yeast extract, etc. Anaerobic bacteria are also used in MFCs. Instead of utilizing an anode as an electron acceptor, microbes can use a cathode, to which a low level of current is

3.1 Water coverage Earth’s surface

applied, as an electron donor. These electrons then can be used by the organisms to reduce and synthesize useful organic molecules such as butanol, allowing electrical energy to be changed into chemical energy. The bacteria generate electrons from organic molecules, and use the anode as an external terminal electron acceptor as the electrons transferred ultimately travel to the cathode where they reduce to oxygen. Since the most inexpensive and abundant sources of carbon available are often industrial wastewaters, MFCs have great potential for improving the efficiency of bioremediation for industrial wastes by allowing energy to be recovered during effluent processing. In order to increase the efficiency of the transfer of electrons from the plasma membrane onto the anode surface, mediators have been used. These molecules have special properties, which permit their insertion across the plasma membrane of microbes. They tap into the electron transport chain, becoming reduced in the process, after which they become reoxidized by transferring electrons to the fuel cell’s anode. When the anode terminal of an MFC is surrounded with oxygen, it results in the production of CO2 and H2O. Complete oxidation of one mole of glucose to carbon dioxide liberates 24 moles of electrons: C6 H12 O6 1 6H2 O 1 6O2 -6 CO2 1 12H2 O

But when the terminal electron acceptor is replaced by a mediator then the electron is trapped by the mediator, which get reduced and carry electrons to the electrode at the anodic chamber. However, in the absence of O2 (anaerobic condition) they produce carbon dioxide, protons, and electrons: C6 H12 O6 1 6H2 O-6CO2 1 24e2 1 24H1

Thus the energy output in an MFC mainly depends on the metabolic activity of the microbes associated with the anode surface. The ultimate destination of these electrons passing through an electric circuit is the cathode terminal where ferrocyanide is reoxidized to ferricyanide, while hydrogen ions combine with oxygen to form water: 4FeðCNÞ36 1 4e2 -4FeðCNÞ36 4FeðCNÞ46 1 4H1 1 O2 -4FeðCNÞ36 1 2H2 O

In order to commercialize MFCs, maximum efforts are in trial based on several factors including (1) the selection of more potential bacteria [76,77] in combination with effective electron mediators [56,78], (2) the use of an anaerobic (nonoxygenated) atmosphere at the anode [79]; (3) increasing feeding rates of fuel (sugars); (4) the modification of electrodes such as the immobilization of electronophores (and the use of conductive polymers); (5) bubbling oxygen through the cathode compartment. Current densities as high as 1.5 mA cm2 have been reported from MFCs and power outputs of up to 3.6 W m2.

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3.1.5.2 Microbiology of fuel cells 3.1.5.2.1 Types of microbes in microbial fuel cells Mostly, bacteria associated with MFCs are electrochemically active (electrogenic bacteria), and belong to facultative anaerobic groups including Enterococcus faecalis, Enterococcus gallinarum, and P. aeruginosa [80] (Fig. 3.16). Most bacteria available on the anode electrode surface are in the form of a thin film and are from Proteobacteria (Alpha-, Beta-, Delta-, and Gamma-), ironreducing Firmicutes, and hydrogen- and formate-requiring anaerobic Bacteroidetes [80,81]. These bacteria are distributed on the electrode surface in groups. Mostly, Alphaproteobacteria dominate the community, while at other times Gamma- or Beta- dominate, or there is no dominate type. Proteobacteria are a phylum of bacteria that are divided into classes termed Alpha-, Beta-, Gamma-, and Delta-. These broad categories include aerobic and anaerobic bacteria as well as fermentative bacteria and pathogens. Shewanella spp. (S. oneidensis), and several members of the family Geobacteraceae including Geobacter sulfurreducens and Geobacter metallireducens have been noticed to be more capable of transferring electrons to an anode through direct contact compared to others [82]. Shewanella spp. (Fig. 3.17A) originate in soil, survive on a variety of carbohydrates available in the soil, and produce electrons that are released back into the soil. These electrons can be harnessed and used to create electricity, which is a form of energy. Certain Shewanella spp. (S. oneidensis) (Fig. 3.17B) produce endogenous electron mediators, which are reversibly reducible molecules that function similarly to exogenous mediators, except that bacteria biosynthesize them [83]. Electricity generation from soil using MFC technology is little different from the conventional type of MFCs. In soil-based MFCs, the anode electrode is buried

FIGURE 3.16 Association of microbes on the surface of electrodes in a microbial fuel cell.

3.1 Water coverage Earth’s surface

FIGURE 3.17 (A) At the Department of Energy’s EMSL, a scanning electron micrograph shows Shewanella putrefaciens CN32 cells on the surface of hematite particles. CN32 is a metalreducing bacterium important for the cycling of carbon and metals in the environment. It has potential applications for bioremediating metals and radionuclides. (B) Shewanella oneidensis solely live on power from electrodes without oxygen. (A) Image gallery. From https://en.wikipedia.org/wiki/Shewanella#/media/File:Shewanella_oneidensis.png (B) With courtesy PLo Biology. From https://commons.wikimedia.org/wiki/File:Shewanella_oneidensis.png

in damp soil. The soil bacteria form a biofilm on the surface of the anode and supply electrons to the anode, which ultimately travel through a circuit wire linked with the cathode that is placed on the top of the soil, leaving one of its side completely exposed to open atmosphere. Electrons from the bottom electrode travel up a wire to the top electrode and, once there, they react with oxygen (from the air) and hydrogen (made by the bacteria as it digests nutrients in the soil) to create water.

3.1.5.2.2 Bacterial metabolism and electron transfer in microbial fuel cells Several members of the family Geobacteraceae including G. sulfurreducens (Fig. 3.18A) and G. metallireducens have been shown to be capable of transferring electrons to an anode through direct contact (Fig. 3.18B). The exact mechanism by which this transfer occurs is not fully understood, but it is thought that they use some form of electrochemically active protein present on the outer surface of the cell, and there is some evidence to suggest that electrically conductive pili may be involved in the process of electron transfer as well. Although there is no known evolutionary pressure for these bacteria to be able to generate an electrical current, it is likely that the mechanism used by Geobacteraceae cells to transfer electrons is the same that they use to reduce insoluble extracellular deposits of Fe(III) and Mn(IV), both of which Geobacteraceae spp. have been shown to be well adapted to utilize as an electron acceptor [84]. There is an ongoing debate in MFC literature as to the benefits of using a mixed community of bacteria versus using a single strain of bacteria that is known to have efficient EET. However, the option exists to genetically modify

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FIGURE 3.18 (A) Geobacter sulfurreducens (form biofilms on glassy carbon electrodes; Image gallery Credit: Anna Klimes and Ernie Carbone, UMass Amherst, from https://en.wikipedia.org/ wiki/Geobacter_sulfurreducens#/media/File:Geobacter.jpg). (B) Electricity producing Geobacter sulfurreducens biofilms cells close to the electrode are proposed to transfer electrons via membrane-bound cytochromes, whereas cells furthest from the electrode are able to use a conductive nanowire network for long range electron transfer to the electrode. Oxidation of the organic substrate throughout the biofilm leads to an accumulation of protons within the biofilm.

bacteria to create an ideal exoelectrogen strain of bacteria [85]. Both Rhodopseudomonas palustris DX-1 and G. sulfurreducens were shown to produce larger voltages than mixed cultures of bacteria in MFCs. In MFCs, bacteria act as living catalysts to convert organic substrates into electricity. While this technology may sound like an answer to the energy crisis, MFCs are not yet viable for commercial applications. Still, research is committed to optimizing their performance [86
88]. In a biofuel cell, through microbial metabolism, direct electricity is produce using conventional electrochemical technology [89,90]. In MFCs, biochemical energy is generated by bacterial biocatalytic oxidation of organic compounds to the chemical reduction of an oxidant at the interface between the anode and the cathode (Fig. 3.19). Yet little is known about bacterial interactions with electrodes. Research has been focused on understanding microbial anodic electron transfer. Anoderespiring bacteria catalyze electron transfer in organic substrates onto the anode as a replacement for natural extracellular electron acceptors (e.g., ferric oxides or humic substances) by a variety of mechanisms. On the basis of electron release and transfer, the bacteria associated with fuel cells can be grouped into three types namely (1) bacteria that directly transfer electrons to the anode using the anode as a terminal electron acceptor, (2) bacteria that use both natural and

3.1 Water coverage Earth’s surface

FIGURE 3.19 Biocatalytic oxidation of organic compounds to the chemical reduction of an oxidant at the interface between the anode and cathode.

chemical mediators to transfer electrons to the anode, and (3) those who can accept electrons from the cathode. In the first category, the bacteria require physical contact with the electrode for current production. The contact point between the bacteria and the anode surface requires an outer membrane
bound cytochrome complex. There are also several microorganisms reported that can transfer electrons across the membrane by themselves to the anode [91]. These microorganisms are stable and have high coulombic efficiencies. Shewanella putrefaciens, G. sulferreducens, G. metallireducens, and Rhodoferax ferrireducens [91
93] are all effective and form films on the anode surface and transfer electrons directly to the electrode across the membrane. These microorganisms act as mediators in electron transport process, and reduce the burden of chemical mediators which are supposed to be potential pollutants. The anode here acts as the final electron acceptor for the cell and, thus, effectively enhances the electricity generation. Although the direct contact of an outer-membrane cytochrome to an anodic surface would require microorganisms to be situated upon the electrode itself (Fig. 3.20). In the second category, bacterial mediators in oxidized state are easily reduced by capturing electrons from within the membrane of microorganisms. Several reports are available [94
99] on the fact that the metabolic reducing power produced by Proteus vulgaris or Escherichia coli can be converted to electricity using electron mediators such as thionin or 2-hydroxy-1,4-naphthoquinone (HNQ). Tanaka et al. [100] reported that light energy can be converted into electricity by Anabaena variabilis when HNQ is used as an electron mediator. Park et al. [90] confirmed that with viologen dyes cross-linked with carbon polymers and absorbed on Desulfovibrio desulfuricans, cytoplasmic membranes can mediate electron transfer from bacterial cells to electrodes or from electrodes to bacterial

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FIGURE 3.20 Diagrammatic presentation of direct association of microbes on the surface of the anode in microbial fuel cell.

cells. The electron transfer efficiencies in MFCs could be improved if more suitable electron mediators were used (Fig. 3.21). Good mediators should have several characteristics [101], that is, (1) it should be cell membrane permeable, (2) have an electron affinity greater more than the electron carriers of the electron transport chains, (3) possess a high electrode reaction rate, (4) be well soluble, (5) be completely nonbiodegradable and nontoxic to microbes, and (6) be of low cost. These characteristics describe the efficiency of mediators. Theoretically, lower redox potential mediators are supposed to be better than the higher redox potential mediator with reference to high affinity for electrons absorbing from electron carriers in microbial fuel cells (MFCs). MB, NR, thionine, Meldola blue, Fe(III) EDTA are synthetic mediators, but their toxicity limits their use in MFCs [102,103]. Microbes are also reported to use naturally occurring compounds including microbial metabolites (endogenous mediators) such as humic acids, anthraquinone, and the oxyanions of sulfur (sulfate and thiosulfate) [104]. All of these can transfer electrons from inside the cell membrane to the anode. In the third category of microbes such as Thiobacillus ferrooxidans the cathode acts as electron donor. These organisms cause a potential difference in the cathode, driving a suitable reaction at the anode by anodophillic microorganisms to produce electricity [105].

3.1 Water coverage Earth’s surface

FIGURE 3.21 Mechanisms involved in electron transfer. (A) Indirect transfer via mediators or fermentation products; (B) direct transfer via cytochrome proteins; (C) direct transfer via conductive pili.

An ideal electron mediator for converting metabolic reducing power into electricity should form a reversible redox couple at the electrode, and it should link to NADH and have a high negative E00 value in order to maximize electrical energy generation. It should also be stable in both oxidized form and reduced form and should not decompose during long-term redox cycling. The mediator polarity should be such that the mediator is soluble in aqueous systems (near pH 7.0) and can pass through or be absorbed by the microbial cytoplasmic membrane. The amount of free energy produced either by normal microbial metabolism or by MFC systems is determined mainly by the potential difference (ΔE) between the electron donor and the acceptor according to the equation: 2ΔG 5 nFΔE;

where ΔG is the variation in free energy, n is the number of electron moles, and F is the Faraday constant (96,487 J/V) [67,81]. The coupling of metabolic oxidation of the primary electron donor (NADH) to reduction of the final electron acceptor (such as oxygen or fumarate in bacterial respiration systems) is very similar to the coupling of the electrochemical process of a fuel cell or a battery system [68,82]. Biological reducing power sources with

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low redox potentials such as NADH (E00 5 2 0:32 V), reduced ferredoxin (FdH2) (E00 5 2 0:42 V), or reduced flavin adenine dinucleotide (E00 5 2 0:19 V), can act as reductants for fuel cells, but they are not easily converted into electricity because the cytoplasmic membrane has to be nonconductive to maintain the membrane potential absolutely required for free energy (i.e., ATP) production [106]. There is limited information about the factors that affect the power generation of MFCs. Organic material loading in soil enhances the availability of more and diversified microflora in the soil. Industrial and domestic wastewater [107], sewage sludge [108], marine sediment [109,110], and garden compost [111,112] have bacterial population contents of approximately 109 cells/g [113] and organic matter contents of around 100 mg/g [114]. Such resources are rich in electrogenic bacteria and have the ability to produce electrons to generate electricity. Among different wastewaters [115,116] that were used in MFCs, dairy wastewater contains complex organics such as polysaccharides, proteins, and lipids, which, on hydrolysis, form sugars, acids, and fatty acids. Dairy wastewater treatment in MFCs produce lower power densities in comparison with other wastewaters [117,118]. Besides the organic materials and microflora, various other factors also influence the electrical energy production in MFCs. Ishii et al. [119] noticed that when the anode chamber was filled with methane gas emitted from soil, the energy generation activity of the MFC was continued till the exhaustion of the methane supplied to the anode chamber. This could have been due to a reduction of soil organic carbon to generate electrical power rather than methane. Like methane, when the anode chamber of a two-chambered MFC is filled with phenolic waste, the activity of power generation is continued till 90% of the phenol is removed from the soil, compared with 13% in non-MFC controls [120]. Several physicochemical factors are noticed influence power generation in MFCs. The distance between electrodes was noticed to directly influence the internal resistance of MFCs [121]. The presence of dissolved oxygen impairs the anaerobic conditions at the anode and decreases power output [122,123] and the influence of temperature dependence microbial activity was observed as a major factor influencing soil-based MFCs. Lorenzo et al. [124] reported the effect of three dimensional anode surface area on the power performance of singlechamber MFCs for the generation of electric energy, and observed a direct correlation between anode surface area and MFC power generation performance.

3.1.5.2.3 Factors affecting electricity generation Primarily, the performance of MFCs depends on the site of installation. When an MFC is installed on soil it is known as an SMFC. Variations in electricity output have been observed when MFCs are implanted on different types of sediment soils convert chemical energy from soil organic compounds into electricity via catalysis by soil source exoelectrogenic microorganisms. The process of soil power generation has several potential applications. Followings are some interesting data are available on performance of MFCs in different types of sediment soil (SMFC), and plants fuel cell (PMC). When electrodes were placed on the bottom

3.1 Water coverage Earth’s surface

of the sediment (anode) and either on top of the sediment or suspended in the water phase (cathode) [125,126], the overall performance of SMFCs was noticed to be good. Organic materials excreted from plants give good performance in PMFCs [121,127
129]. SMFCs and PMFCs have great promise, not only for sustainable electricity recovery from the environment, but also for their potential application in supplying electricity in self-powered devices. Such applications include devices that monitor environmental parameters [130], sensors to monitor the maturity of plants [131], and applications in the bioremediation and recovery of heavy metals from contaminated environments [132]. A number of factors, such as the speed of substrate oxidation, electron transfer to the anode, proton transfer from the anode to the cathode, and oxygen reduction at the cathode were notice to be affective in the overall function of SMFCs and PMFCs [79,133
135]. The quality and quantity of microbes associated with SMFCs and PMFCs were noticed to be major factors in improving the productivity of power generation. In addition, the physicochemical nature of these fuel cells is an important factor. In connection to this, it has been observed that modification of the anode is also one of the most important strategies for improving the performance of SMFCs and PMFCs. Several materials have been used to increase the surface area to allow for the attachment of a greater number of microorganisms. These materials include graphite felt, graphite granules, biochar [135], active carbon, and graphite grains [77]. Interestingly, it has been noticed that members of the genus Shewanella have high potential to reduce graphene oxide (GO) to electrically conductive graphene. GO is an intermediate product of graphene obtained by the chemical exfoliation of graphite. Microbial GO reduction occurs via respiratory EET, where GO is used as the terminal electron acceptor. It has been shown that GO can enhance the capability of bacteria for EET and the resultant reduced form of GO functions as an electrode with the attached bacteria. An exogenous supply of GO was found to improve power generation in both the anode and the cathode in MFCs when microbial cultures were used [136]. A positive aspect of using GO is that is it a good absorbent of toxic chemicals including heavy metals and organic pollutants, although both GO and graphene have been reported to have toxic effects on a number of living systems. The presence of dissolved oxygen in the anode chamber plays a critical role in the functioning of MFCs [137
140]. An anaerobic atmosphere is usually provided by passing nitrogen and carbon dioxide gas through the anode compartment. Eliminating the presence of oxygen would lead to increased transfer of electrons from the bacteria to the electrode, rather than to oxygen. On the other hand, it has been observed that when oxygen is bubbled through the cathode compartment it enhances the production of power.

3.1.5.2.4 Power generation in microbial fuel cells Generally, the performance of an MFC is mainly influenced by the surrounding physicochemical factors, the type of microbes used, and the nature of electrodes (Table 3.5) [141
146].

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Table 3.5 Maximum current output of different types of microbial fuel cells (MFCs). Nature of MFC

Microbe used

1

Double chamber

Rhodopseudomonas palustris DX-1

2

Double chamber based on mixed microbial film as source of electrons Double chamber based on Geobacter spp.

Geobacter sulfurreducens grown on acetate produced G. sulfurreducens

4

Double chamber

5

Plant-based

6

Rhizodeposit of rice plant

Microbial bioelectrocatalysis Plant root colonized microbes as source of electrons Plant deposit compounds

3

Current output 2770 mW/m2 projected surface area 2.15 kW/m3 anode volume

Reference

Current density of 3.9 W/m2 200
390 A/ m2 6 mW/m2

[111

330 Wha21

[114]

[109]

[110]

[112] [113

Greater efficiency in electron transfer and, thus, an increase in current generation and power output have been attained by modifying graphite electrodes, using alternative electrodes [147,165] by employing a mixed bacterial culture, and using bacteria with higher metabolic rates [148]. Different electron mediators have also been used to enhance the power output. A roughly 10-fold increase in current was noticed using NR as an electron mediator [149].

3.1.5.2.5 Types of microbial fuel cells Varieties of MFCs are in use, both in research and commercialization. The design of MFCs depends on the nature of its application. Mainly, four types of MFCs, namely double-chamber MFCs, single-chamber MFCs, up-flow MFCs, and stacked MFCs, are in use for laboratory model development or to confirm their efficiency at pilot level. However, on the basis of implantation site and the nature of the function, MFCs can be categorized as soil-based microbial fuel cells (SMFCs), plant-based microbial fuel cells (PMFCs), and desalination MFCs. The nature of the components used in the design and fabrication depend on the purpose of the MFC to be used such as bioelectricity generation, wastewater treatment, bioremediation of toxic compounds, biohydrogen production, or desalination of seawater. MFCs are operated at the optimized parameters, namely thermophilic temperature, neutral pH, etc., for better results. Double-chamber microbial fuel cells. A typical double-chamber MFC has an anodic chamber and a cathode chamber separated by a proton permeable

3.1 Water coverage Earth’s surface

FIGURE 3.22 A double-chamber microbial fuel cell showing bacterium associations with the anode surface for suppling electrons by glucose metabolism.

membrane (polymer-electrolyte membrane; PEM) or a salt bridge to permit protons to move across to the cathode while obstructing the diffusion of oxygen into the anode (Fig. 3.22). The double-chamber MFC runs in batches, and can be used for producing a high power output, even in inaccessible conditions. It can be suitably up-scaled to treat large volumes of wastewater and other sources of carbon [150]. Single-chamber microbial fuel cells. Due to their intricate designs, two-chamber MFCs are tough to scale-up even though they can be functioned in batch or continuous mode. Single-chamber MFCs offer simpler designs and are cost effective (Fig. 3.23). They normally possess only an anodic chamber without the requisite of aeration in a cathodic chamber. With a slight modification of the basic design, the efficiency of MFCs can be upgraded. Park and Zeikus [56] designed a singlechamber MFC comprising of an anode in a rectangular anode section linked with a porous air cathode that was directly open to the air. Protons are transported from the anode solution to the porous air cathode. Liu and Logan [151] designed an MFC containing of an anode positioned inside a plastic cylindrical chamber and a cathode located outside. The anodes were normal carbon electrodes, but the cathodes were either porous carbon electrodes or PEM bonded with flexible

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FIGURE 3.23 Schematic presentation of a one-chamber microbial fuel cell.

carbon cloth electrodes. Cathodes are often covered with graphite in which electrolytes are passed in a steady fashion, which behaves as catholytes and prevent the membrane and cathode from drying. Thus water management or better fluid management is an important issue in such single-chambered fuel cells. A tubular MFCs with an exterior cathode and an interior anode using graphite granules was constructed by Rabaey et al. [152]. In the absence of a cathodic chamber, the cathode solution was supplied to the cathode by soaking an electrolyte over the outer woven graphite mat to keep it from drying up. Up flow
style microbial fuel cells. The up flow mode of MFC falls between the classification of single-chambered and double-chambered MFCs with continuous flow mode (Fig. 3.24). A Plexiglas cylinder is separated into two segments by glass wool and glass bead sheets. These two units help as anodic and cathodic chambers correspondingly. The disk-shaped graphite anode and cathode are separated with a layer of glass wool. There are no distinct anode solution and cathode solution. The diffusion barricades concerning the anode and cathode offer a dissolve oxygen (DO) gradient for appropriate action of the MFCs. Stacked microbial fuel cell. A stacked MFC is combination of many MFCs connected in parallel or series manner to increase the output of electric power [153,154]. In such complex system (Fig. 3.25) no noticeable adverse effect on the maximum power output per MFC unit was observed. The plant microbial fuel cell. Plants and surrounding soil rich in decomposed root, leaching organic matters from plant roots, and associated microbes are together known as Plant-Microbial Fuel Cell (P-MFC). The organic contents of the soil are oxidized by microbes, and release CO2, protons, and electrons. Electrons are passed on into the anode of the PMFC. The anode is linked with a wire circuit to the cathode (Fig. 3.26).

3.1 Water coverage Earth’s surface

FIGURE 3.24 Schematic diagram of an up flow microbial fuel cell model.

FIGURE 3.25 Schematic diagram of microbial fuel cell in series connection.

The protons release from the anode to the cathode through a proton permeable membrane. At the cathode, oxygen is reduced by association with the protons and electrons to water. At present, the maximum current density in a PMFC is about 3.2 W/m2, which would allow a roof measuring 100 m2 to supply electricity to a house with an average consumption of 2800 kWh a year.

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FIGURE 3.26 Schematic diagram of a plant-based microbial fuel cell.

The PMFC can potentially be used to exploit wetlands for renewable energy generation. About 6% of the Earth’s surface is covered with wetland, which could be a potential sustainable energy source. The PMFC technology is low cost, would not compete with any food or feed production, and has a simple management system [155
159]. The technology is still in its infancy, however, a lot of effort has been going on to make the technology economically viable. Presently, the power output is noticed to be low, however, theoretical power output is estimated at 3.2 W/m2 geometric planting area [160]. On the basis of reports available, maximum power output was noticed to be improved from 65 to 220 mW/m2 by considering plants as the sole organic matter source. Some current biomass-electricity systems like anaerobic digestion produce the same amount of electricity per geometric planting area as the maximum that is achieved in PMFCs (220 mW/m2). So, even at current power output, PMFCs could compete with anaerobic digestion based on

3.1 Water coverage Earth’s surface

electricity production per geometric planting area. But the maximum power outputs of the PMFCs have been achieved in short-term tests like polarization curves and were not sustained for long periods of time. Over longer periods of time, the average power output is limited maximally to 50 mW/m2 geometric planting area [161]. This could have been due to an increase of membrane resistance and buildup of ion-transport resistances. However, when a flat-plate PMFC was used, the average power output was noticed to increase in magnitude. The tubular PMFC was designed [162] to increase the efficacy for this technology. Two types of anodes, namely a graphite felt and graphite granules, were used to observed the performance of PMFCs. The average power output based on membrane area was 10 mW/m2 for felt and 12 mW/m2 for graphite granules. The corresponding mass and volume power densities for the felt were 15 and 69 times greater than those for the granules respectively. This showed that a decrease in the use of anode electrode material is possible while achieving comparable power outputs per square meter of membrane. These findings make future applications of the PMFC technology more feasible due to the cost reductions per kilowatt hour. Furthermore, this PMFC design could likely be applied in soils without the need to excavate the topsoil [163]. Tubular microbial fuel cell. This type of MFC is either single-chambered or double-chambered, and oxygen or chemical catholytes are used as proton acceptors [178] and wastewater as a substrate. This MFC was constructed by hot pressing a PEM to a carbon cloth with Pt catalyst and placing it around a tube with holes drilled into it to allow oxygen transfer. Eight graphite rods were placed around this tubular cathode and the system was enclosed in a plastic chamber (Fig. 3.27). The tubular cathode was open on each end to allow oxygen diffusion to the cathode, while the wastewater was fed continuously to the system. A maximum power density of 26 mW/m2 was produced in this continuous flow system. When air was forced through the cathode, power production was reduced; reiterating the problems caused by increased levels of oxygen diffusion into the anode compartment of an MFC [179]. Glass beads and wool were also used as separation in a two-chamber column MFC lacking a membrane. Artificial wastewater was fed through an anode chamber with graphite felt, through the glass beads and wool, to the cathode chamber containing graphite felt and sparged with air. This system only produced 1.3 mW/m2, with the limiting factor most likely being the mass transfer of protons between the two electrodes [164]. A similar system was constructed using graphite rods in place of graphite felt for both the anode and cathode. A maximum power density of 10.9 mW/m2 was reported [165]. The glass beads and wool have also been replaced with a perforated polyacrylic plate in other MFC designs [166,167].

3.1.5.3 Components of a microbial fuel cell 3.1.5.3.1 Anode An anode electrode should be noncorrosive, nonfouling, and porous. Thus, commonly, carbon-based electrodes are in use due to their good conductivity,

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FIGURE 3.27 Tubular up-flow air-cathode microbial fuel cell. (A) Section and top views, (B) system view, and (C) porous monolithic carbon anode. With courtesy Kim JR, Premier GC, et al. Development of tubular microbial fuel cell (MFC) employing a membrane electrode assembly cathode. J Power Source 2009;187(2):393
9.

porosity, low cost, and long durability. Additionally, they are available with different surface areas, and the versatile nature of structural design can accommodate bacterial colonies easily [168]. The main problem associated with anodes is the colonization of bacteria as a source of electrons. So, it is advisable to use a carbon-based anode to avoid the problem of corrosion [168]. A stainless steel noncorrosive electrode is also a good option for MFCs. Carbon electrodes are proven as the most versatile and are easily available as compact graphite plates, rods, or granules, as fibrous material (felt, cloth, paper, fibers, foam), and as glassy carbon. There are numerous carbon suppliers worldwide, for example, E_TEK and Electrosynthesis Co. Inc. (United States), GEE Graphite Limited, Dewsbury (United Kingdom), Morgan, Grimbergen (Belgium), and Alfa-Aesar (Germany). Generally, graphite plates are inexpensive, easy to handle, and have a defined surface area [169,170]. Carbon fiber, paper, foam, and cloth (Toray) have been extensively used as electrodes. Substantially higher surface areas are achieved either by using a

3.1 Water coverage Earth’s surface

compact material like reticulated vitreous carbon (RVC; ERG Materials and Aerospace Corp., Oakland, CA), which is available with different pore sizes, or by using layers of packed carbon granules (Le Carbone, Grimbergen, Belgium) or beads [171,172]. Graphite felt has more advantage than graphite rods as it has three-times more surface area and generates large amounts of power densities. Plenty of research materials are available on the use of graphite felt and rod anodes to have comparative knowledge on the functional efficiency of the graphite anodes used in MFCs [173
175]. Thus the facts and figures say that the power density produced by MFCs depends on the nature of the microbes used and the design of the anode (Table 3.1). Microbial film formation enhances the power generation potential of the electrode of MFCs. But this can be further improved with the use of a graphite fiber brush. By treating the brush with ammonia, a faster colonization can be achieved [176]. The ammonia treatment is carried out by heating the brush materials in ammonia environment at 700 C for an hour in NH3 helium gas. The ammonia treatment provides new material characteristics that support faster bacteria adhesion and improve electron transfer activity on the anode surface. The overall performance of the anode can be increased by coating it with suitable metal. Iron-oxide-coated anodes were noticed to give better power outputs, as compared to a normal MFC carbon-paper-coated electrode. But it has been noticed that an iron-oxide-coated anode can be used to reduce the acclimation time for bacterial colonization [177]. Reports are also available on the use of stainless steel, titanium, tungsten, and aluminum oxide. Tungsten is the only material that reduces the bacterial colony acclimatization. By the application of nanoengineering technology, the efficiency of anode activity in an MFC can be increased. The application of heterogeneous ionexchange membrane technology has improved the electrochemical properties, lowered the production cost, and made the preparation procedure easier. Additive blending, membrane surface modification, and posttreatment are typical methods used to improve heterogeneous ion-exchange membranes characteristics. By enlarging the capacity of the electron accepting quality, the heterogeneous fabrication method with the use of platinum nanoparticles has shown quite encouraging results regarding the capture of electrons by the anode of an MFC [178,179].

3.1.5.3.2 Cathode All of the carbon-based materials discussed in the previous section (Section 3.1.5.3.1) for application as an anode can also be used as cathode materials with the addition of catalysts. As the use of platinum is cost-effective, cobalttetramethoxy-phenylporphyrin (CoTMPP) has been used as low cost cathode. By such modification, Pt loadings can be reduced to 0.1 mg/cm2 with only a 19% reduction in power production, but the overall fabrication cost of the cathode was noticed to be reduced. Carbon paper or carbon cloths are commonly used materials for cathode fabrication. When used in a single-chamber MFC, these materials

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will be wet-proof due to the structural design of the system. For better performance, a precoated carbon cloth and carbon paper with carbon/Nafion paste can be used [180]. By this technique, an increase in power production of 68% was noticed, compared to a system with the direct use of commercial carbon cloth and carbon paper [181]. As stated previously, a cathode is also made of a porous carbon electrode or PEM bonded with a flexible carbon cloth electrode. In order to improve performance, cathodes are often covered with graphite in which electrolytes are continuously supplied as catholytes to keep the membrane and cathode wet. Based on physicochemical nature, the catalyst on the electrode and the cathodic electron acceptor play important roles in the electricity generation of MFCs [182,183]. Dissolved oxygen, ferricyanide, potassium permanganate, or manganese dioxide has often been used as cathodic electron acceptors in twochambered MFCs. Among the various catholytes used potassium ferricyanide (K3[Fe(CN)6]) was noticed to be the most prominent, especially in twochambered MFCs. The main advantage of ferricyanide is its low potential (close to its open circuit potential) as compared to plain carbon cathode. However, a disadvantage is the insufficient reoxidation by oxygen, which requires the catholyte to be regularly replaced [180]. In addition, the long-term performance of the system can be affected by the diffusion of ferricyanide across the cation exchange membrane and into the anode chamber. Oxygen is noticed to be the most suitable electron accepter due to its high oxidation potential, availability, low cost (it is free), sustainability, and the lack of a chemical waste product (water is formed as the only end product). An efficiently performing cathode would use dissolved oxygen as the electron acceptor. Due to the low concentration of dissolved oxygen in side water, this kind of cathode will not produce a large driving force in comparison to other types of cathodes. On the other hand, this type of cathode does not need replacement since the only element it consumes is oxygen, allowing it to perform for a long period of time. The performance of a cathode mainly depends on its purpose of use in different places. For saline sediment soil, graphite disk electrodes were noticed to be the most suitable [132]. Generally, in seawater, oxygen reduction depends on the quality and quantity of the microflora present [111]. Such microbial assisted reduction has also been observed for stainless steel cathodes, which rapidly reduce oxygen when aided by a bacterial biofilm. Pt catalysts are usually used to increase the rate of oxygen reduction for dissolved oxygen or open-air (gas diffusion) cathodes [184]. In order to reduce the costs of MFCs, the Pt load can be kept as low as 0.1 mg/cm2 [185]. The long-term stability of Pt needs to be more fully investigated, and there remains a need for new types of inexpensive catalysts. It has been observed that some noble-metals like pyrolyzed iron(II) phthalocyanine or CoTMPP have high potential for generating electric power in MFC cathodes [186].

3.1 Water coverage Earth’s surface

3.1.5.3.3 Proton exchange membrane Proton exchange membrane or polymer-electrolyte membrane (PEM) is a separator used in MFCs that separate the anode and cathode compartments and transfer protons from the anode to the cathode. The potential of a PEM is judged on the basis of power density and coulombic efficiency. PEMs are semipermeable in nature, and are generally made from ionomers that carry protons while acting as an electronic insulator. They do not allow any reactants (oxygen and hydrogen) to pass through. A variety of materials like Ultrex, Nafion, bipolar membrane, dialyzed membrane, polystyrene, and divinyl benzenes with a sulfuric acid group, glass wool, nanoporous filters, and microfiltration membranes are in use for fabricating PEMs, but Nafion is the most commonly used for PEMs. It is a perfluorosulfonic acid membrane composed of hydrophobic fluorocarbon backbone (
CF2
Cf2
) in association with hydrophilic sulfonate groups (SO2 3 ). These negatively-charged sulfonate groups enhance the cations conductivity of the Nafion matrix. The performance of a fuel cell mainly depends on the hydration and thickness of the Nafion used. In spite of having many good quality Nafion is still not suitable for higher range of pH, and presence of cation species such as 15 Na 1 , K 1 , and NH1 times higher than proton ion concentration). 4 (that 10 These cations have more potential to pass through the PEM as compared to protons, and are responsible for increases in pH in the cathode compartment [187]. Due to the high cost value of fluorine (a component of Nafion membrane) it has been difficult to market Nafiob membrane, as compared to other related products [188]. Ultrex is a better option in place of Nafion due to its high mechanical stability and low cost [189].

3.1.6 Applications of microbial fuel cell technology A diversified range of sustainable resources can be used for direct power generation using MFCs. Generally, for laboratory purposes, simple organic substrates like acetate and glucose are used for various experimental purposes, however, many complex organic substrates can also be used. Effluent from industries, wastewater from food processing plants, landfill leachate, and wetlands are proven to be good resources for operating MFCs and meeting the local area energy demand in the near future. Although MFCs have been studied as an alternative energy source, their application is presently limited to certain niche areas. With further improvements in design, cost effectiveness, and performance efficiency based on these near-future applications, it would be possible to scale-up and use MFCs as a renewable energy resource. The beginning of the 19th century witnessed the conceptual development of fuel cells using microbes as the source of electrons for activating the anode. The MFC is an alternate source of power without the emission of carbon dioxide. In MFCs, organic substrates are biologically oxidized by anaerobic microbes and produce electrons, which is ultimately responsible for power generation

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[190,191]. MFC technology is otherwise known as a green energy technology resulting from the amalgamation of life sciences, physical science, and engineering technology. The working principle of MFCs is based on the tenets of microbial physiology coupled with electrochemistry. The structural design of MFCs brings the nuances of electrical and materials engineering to the fore. The applications of this technology come under the ambit of environmental engineering and bioremediation. MFC technology is, thus, multidisciplinary, in the true sense of the term, and provides scope for strengthening research across disciplines.

3.1.6.1 Wastewater treatment Wastewaters are actually a huge “energy storage tank.” Additionally, wastewater contains diversified organic materials [192], and is supposed to be a sustainable source of direct electricity production. Different kinds of wastewaters such as sanitary wastes, food processing wastewater, swine wastewater, and corn stover wastewater contain biodegradable organic wastes, which are, generally, used in bacterial metabolism and are ultimately helpful in the production of ions responsible for energy generation in MFCs [193,194]. Thus MFC technology is emerging as an efficient treatment system with high operational sustainability and low material costs. By means of this technology, the removal of unwanted nitrogen and organic matters from leachate could also be possible as a credible and highly cost-effective method [194,195]. Domestic or municipal wastewater can be recycled by means of MFC technology. A cylindrical MFC can generate 146 mW/m2 of electrical energy from wastewater having 200
300 mg/L chemical oxygen demand (COD) at pilot plant level. In this same cylindrical MFC design, using swine wastewater with about 8320 mg/L COD load, a power density of 261 mW/m2 can be generated [196]. Encouraging data are also available on wastewater from potato processing factories and meat processing wastewater [197] as well as brewery wastewater, corn stover biomass (367
371 mW/m2), and acid mine drainage wastewater [198]. In sediment, MFCs can work well. Rice plants grown on sediment soil leach organic materials. The rhizodeposits (exudates and dead roots) on the surface of anode support to generate high potential as compared to conventional type of MFCs [112,199]. Sediment soil bacteria grow using organic materials and produce electrons. The use of algae has drawn attention as an organic substrate for MFCs. The maximum electricity produced from algal biomass was reported as 110 mW/m2. Even dye-contaminated wastewater can be decolorized by MFC technology (Fig. 3.28). For example, water contaminated by Acid Orange 7 (AO7) dye can be decolorized by the application of a single-chamber up-flow membraneless microbial fuel cell (UFML MFC) [202]. This is a technology for simultaneous generation of electricity and decolorization of wastewater.

3.1 Water coverage Earth’s surface

FIGURE 3.28 Schematic diagram of azo dye degradation by microbial fuel cell.

3.1.6.2 Microbial fuel cell for landfill Landfill leachate contains organic debris, and supports bacterial growth. Landfill organic components can be effectively degraded by repeated circulation after generating power by MFCs [200]. As landfill leachate is rich in organic materials and has a high conductivity nature with a buffering capacity it is a good resource for MFC operation.

3.1.6.3 Generation of electricity directly from plants The PMFC is a unique example of the plant
microbe relationship in the rhizosphere region of plants, which is responsible for the biological conversion of solar energy into electricity without outsourcing of any additional organic materials into the PMFC (Fig. 3.29). PMFCs require anaerobic conditions as in, for example, wetlands (800,000,000 ha worldwide). Wetlands are often unsuitable for crop growth and, thus, PMFCs are not competing for arable land. Even though PMFCs are based on photosynthesis, they can deliver electricity 24 hours a day and allyear round. This is especially interesting in remote areas without electricity or where electricity is delivered by irregular and unreliable variations in solar energy.

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FIGURE 3.29 Diagrammatic presentation of a plant microbial fuel cell. With courtesy Wageningen UR and plant-e.

Wetlands are estimated to account for around 6% of the Earth’s surface. Researchers at Wageningen University, and research conducted in Netherlands have developed a fuel cell that runs off electrons present in the soil around the living roots of plants. During photosynthesis, organic material is produced that plants cannot use, which is then secreted through the roots. Bacteria in the soil break down this organic material, which releases electrons. All that’s needed is an electrode to capture those electrons and you’ve got electricity. The PMFC can be used to supply electricity to remote communities and on green roofs to supply electricity to households. The Wageningen University says that PMFCs can be used on various scales. Initially, on flat roofs or in remote areas in developing countries, and later, when larger effective surface areas become feasible, central grids can be realized in areas of marshland. Researchers think that green energy-producing roofs will become a reality within a few years.

3.1 Water coverage Earth’s surface

Currently, the technology is only able to produce about 0.4 W/m2 of plant growth, but researchers think that soon they’ll be able to boost the output to 3.2 W/m2, which would allow a 100-square-meter green roof to power a household with an average energy consumption of 2800 kWh per year. Plants that can be used include any common grasses as well as rice in warmer climates. The major benefit to the PMFC over other renewable energy technologies is that it doesn’t compete for land use like solar panels, wind farms, and biofuel production do since the electricity production largely happens underground. In 2012, the researchers have created a company called ‘Plant-e’ developed plant fuel cell to power things like LED lights, laptops and cell phones. On a larger scale, the company has installed the first proof-of-concept electricitygenerating green roof at the Netherlands Institute of Ecology.

3.1.6.4 Biological oxygen demand sensing Another potential application of the MFC technology is to use it as a sensor for pollutant analysis and in situ process monitoring and control. BOD is the amount of dissolved oxygen required to meet the metabolic needs of aerobic organisms in water rich in organic matter such as sewage. The proportional correlation between the coulombic yield of MFCs and the concentration of assimilable organic contaminants in wastewater make MFCs usable as BOD sensors. An MFC-type BOD sensor can be kept operational for over 5 years without extra maintenance, which is a far longer in-service lifespan than other types of BOD sensors reported in the literature.

3.1.7 Hydrogen production Hydrogen production by modified MFCs operating on organic waste may be an interesting alternative. In such devices, anaerobic conditions are maintained in the cathode chamber and an additional voltage of around 0.25 V is applied to the cathode. Under such conditions, protons are reduced to hydrogen on the cathode. Such modified MFCs are termed bioelectrochemically assisted microbial reactors [201].

3.1.8 Marine microalgae for carbon sequestration or sink Marine algae absorb more Carbon dioxide than they release. The natural process of lessening carbon dioxide burden on the atmosphere is also known as carbon sequestration or carbon sink, which helps in restoring the depleted ozone layer, defer global warming, and avoid dangerous climate changes. In order to decrease carbon dioxide emissions or to develop carbon-free energy sources, finding an efficient method for carbon dioxide sequestration should be a primary issue. Microalgae cultivation would be a good option as they have high potential for carbon dioxide metabolism and are a good source of food for shellfish. Shellfish are reliable in the storage of carbon compared to dead organisms like trees. The

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amount of carbon that can be sequestrated by shellfish is significance. But the sequestrating rate of carbon dioxide of shellfish is not high enough to affect the global climate. Presently, with the help of genetic engineering tools and techniques, the creation of “super shellfish” is in progress. Algae sink onto the seafloor as remnants without further transferring of carbon dioxide. The cultivation of algae is cheap as compared to trees. Algae can be a good resource for carbon dioxide sink, if favorable environmental conditions are maintained in the marine ecosystem. Marine algae are autotrophic in habit. They have the potential for carbon sequestration. These microalgae can be well exploited as carbon sinks by cultivating nearby sea banks where other crops are not grown due to heavy salt contents (Fig. 3.30). Marine algae absorb more carbon than they release. Microalgae are a highly productive species that can double their mass on a daily basis, resulting in a growth rate up to 100-times faster than terrestrial plants. Marine microalgae do not require freshwater. Microalgae biomass consists of three main components: carbohydrate (5%
23%), protein (6%
52%), and lipids (natural oils) (7%
23%). The oil is available in the form of triacylglycerol, which can be easily converted into a diesel-like oil (Fig. 3.31).

(Molecular structure of triacylglycerols)

FIGURE 3.30 An artist’s depiction of algal farms in an arid environment adjoining the sea. With courtesy Greene CH, et al. Marine microalgae: climate, energy, and food security from the sea. Oceanography 2016;29(4):10
15.

3.1 Water coverage Earth’s surface

FIGURE 3.31 A schematic diagram of algal biodiesel production and biological remediation of contaminated marine system. From Akubude VC, Nwaigwe KN, Dintwa E. Production of biodiesel from microalgae via nanocatalyzed transesterification process. Mater Sci Energy Technol 2019;2:216
25. Used with permission from Vivian C. Akubude.

As stated previously, microalgae grow quickly and well compared with terrestrial crops, which take a season to grow and only contain 5% dry weight of oil. Microalgae have high commercial values for biodiesel production, ethanol production, and the production of other value-added products [204,205]. The oil content of microalgae usually varies from 20% to 50% by dry weight (Table 3.6), while some strains can reach as high as 80% [206]. Even a calm sea surface can be used for hydrogen production using cyanobacteria. The cyanobacterial system has two advantages. These bacteria can act as carbon sinks and produce hydrogen. Many model projects are in progress to reach commercial-level hydrogen production. One of the more interesting projects still under the development stage, is the use of flexible H2-barrier plastic bags floating

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Table 3.6 A Comparative view on oil contents: algae versus crop. Name of algae

Chlorella sp. Crypthecodinium cohnii Cylindrotheca sp. Nitzschia sp. Phaeodactylum tricornutum Schizochytrium sp. Tetraselmis suecia

Oil content (% dry weight)

Crop

Oil yield (gallons acre)

25
75 28
32 20 16
37 45
47 20
30

Corn Soybeans Canola Jatropha Coconut Oil palm Microalgae

18 48 127 202 287 636 6283
14641

50
77 15
23

on a calm sea surface [207,208]. For the proposed project, the calm belt about 30 degrees north or south of the “Bermuda triangle” region was taken as the experimental station. Any salt lake can also be used as a field for marine microalgae cultivation. The culture medium used for cyanobacteria is mainly freshwaterbased. The density of the culture medium inside the plastic bag is lower than that of the seawater. So, the culture bags float on the seawater surface. A cluster of about 20 bags, each 25 m 3 200 m, are used for the purpose of microalgae cultivation. Altogether the culture bags cover about 1 km2. The plastic bags are transparent and the outer cover acts as H2 barrier. The hydrogen permeability (pm) value of the transparent plastic bags ranged from 44 to 87 cm2/atm/day (Fig. 3.32). The bioreactor used has three layers of plastic bags (Fig. 3.32). The inside of the plastic bags holds the cyanobacteria culture. The middle bag has a low permeability to hydrogen, and the outside layer of the bag serves as mechanical protection. The thickness of each layer is 0.08 mm. The surface of bioreactor facing sun shine covers 480 cm3 of plastic per m2. Cyanobacteria mutants lacking H2ase grow in large ordinary plastic bags containing carbon dioxide and are subjected to floating on the sea without any mechanical agitation of the medium (Step 1). Cyanobacteria stock culture is transferred to photobioreactors for hydrogen production (Step 2). The innermost bag is occupied with carbon dioxide in air. During the hydrogen production stage, no mechanical agitation is required as carbon dioxide is recycled within the bag. The cyanobacterial cell waste can be used as fish feed [209]. The hydrogen produced from such floating bags is harvested as a gas mixture. After the removal of oxygen from the harvested gas mixture, hydrogen is purified by pressure-swing adsorption (Fig. 3.33). The separated air and carbon dioxide are cycled back into the bioreactors, along with a replenishment of water and the next round of hydrogen production is resumed. Marine microalgae are also the most promising feedstock for the direct

3.2 Conclusion

FIGURE 3.32 Outline of H2 productions by mariculture-raised cyanobacteria. Step 1: Cell growth in a transparent plastic bag floating on the sea surface. The bioreactor is filled with air containing CO2; Step 2: H2 production in a photobioreactor composed of three bags (at least one layer is a H2 gas barrier membrane) floating on the sea surface. The spent cells can be used as fish feed.

production of ethanol. Instead of squeezing algae and collecting their oil, Algenol is trying to engineer the algae to produce ethanol directly (Fig. 3.34). Algenol is a Florida-based biofuel company involved in the production of natural products from algae and other microbes as well as custom biology solutions. Algenol is in the process of producing ethanol directly from some species of cyanobacteria (Fig. 3.35). Algenol uses polyethylene photobioreactors for algae cultures. The cyanobacteria release ethanol into the supporting media, which then partitions between the liquid and the photobioreactor headspace. The ethanol produced is trapped in the closed photobioreactor. The crude ethanol produced thereafter is subjected to purification to meet the quality demand [210,211].

3.2 Conclusion The technology developed by Algenol could be immensely helpful in the production of four most important fuels (ethanol, gasoline, jet, and biodiesel fuel) using algae, sunlight, carbon dioxide and salt water.

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FIGURE 3.33 Outline of photobiological H2 production by mariculture-raised cyanobacteria and delivery of purified H2 to end-users (possible scheme). The fully grown cells (Step 1, Fig. 3.32) are transferred to the photobioreactor (Step 2, Fig. 3.31), which is filled with Ar and CO2 (trace amounts of N2, not shown) and allowed accumulation of the produced gases (H2 and O2). (A) Initial separation of O2 from the gas mixture; (B) further purification of H2 by pressure-swing adsorption, and the removed CO2 and Ar are recycled to the bioreactor. H2O consumed for H2 production is replenished; (C) purified H2 is processed for transportation to end-users.

3.2 Conclusion

FIGURE 3.34 Pictorial view of direct ethanol production from algal cell. With courtesy Algenol.

Direct synthesis Algae

Power CO2

Fresh water H 2O Salt water

H 2O

Closed bio reactor

Product collection

Ethanol

Nutrients Sludge

Chemicals

Product purification

Product concentration

H2O

Loss

Fresh water recycle

FIGURE 3.35 Graphical presentation of a model illustrating how direct ethanol can be produced from cyanobacteria and further processed.

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4

Chapter Outline 4.1 Major soil pollutants ........................................................................................146 4.1.1 Manmade ......................................................................................146 4.1.2 Natural causes of soil pollutants ......................................................151 4.2 Soil quality management ..................................................................................152 4.2.1 Moisture ........................................................................................152 4.2.2 Enhance organic matter ..................................................................153 4.2.3 Avoid excessive tillage ....................................................................153 4.2.4 Manage pests and nutrients efficiency..............................................153 4.2.5 Prevent soil compaction ..................................................................154 4.2.6 Coverage of ground .........................................................................154 4.2.7 Diversity management by multiple cropping ......................................155 4.3 Control of soil pollution ....................................................................................156 4.3.1 Nanoremediation for contaminated soil ............................................158 4.3.2 Immobilization techniques ..............................................................158 4.3.3 Soil washing ..................................................................................161 4.4 Regulatory aspects of soil pollution control .......................................................162 4.4.1 International law for soil protection ..................................................162 4.4.2 European law .................................................................................163 4.4.3 National law...................................................................................164 4.4.4 Building law and regional planning law.............................................164 4.4.5 Close Cycle Management Act...........................................................164 4.4.6 Nature conservation law ..................................................................164 References .............................................................................................................165

Although contaminated soil management and remediation are tough to handle, these can be resolved with systematic approaches. As recommended by the US Environmental Protection Agency (US EPA), and for convenience, the Environment Protection Regulation Act (EP Act), 2009, classified specific management options through conditions such as the requirement for auditing, tracking, treatment, storing, and monitoring. But it has been difficult to compile pieces of information from the EP Act, the regulations, state environment protection policies, and other legislative instruments such as the National Environment Environmental Technology and Sustainability. DOI: https://doi.org/10.1016/B978-0-12-819103-3.00004-4 © 2020 Elsevier Inc. All rights reserved.

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Protection (Assessment of Site Contamination) Measure 1999 (the ASC NEPM). However, on the basis of present environmental conditions and the availability of modern technology, it is advised to go for preferential options for contaminated environment remediation as depicted in Fig. 4.1. The European Union also wanted to have comprehensive and extensive environmental laws obtained through the survey of different developed and developing nations [1,2]. The European Union’s environmental policy resulted from the integration of several global regulatory acts on environmental protection and conservation. The environmental legislation of the European Union also has significant effects on those of its member states. The European Union’s environmental legislation deals with issues like acid rain, ozone layer depletion, air quality, noise pollution, waste disposal that directly or indirectly impact on soil, and water and air pollution. The Institute for European Environmental Policy estimates that the body of EU’s environmental law amounts to well over 500 directives, regulations, and decisions. A significant proportion of environmental legislation in England and Wales originates from EU law, which is directly applicable or implemented through national legislation. The principal environmental regimes are like those of the European Union, which include the Environmental Permitting Regulations (EPR), water quality management, wastes management, contaminated land management, natural water resources conservation and management, and environment impact assessment. The major environmental problems faced by developing countries that effect rural life and villages are deforestation, water pollution, erosion, and salinization of the soil through overirrigation. Earth’s land is the target for pollutant contamination due to human activities and commercially manufactured products that are not properly used (Fig. 4.2).

FIGURE 4.1 Graphic model for preferential management of contaminated soil. Adapted from EPA, USA

Strategies for soil management

FIGURE 4.2 Various sources of pollutants input in the environment.

Imbalances in soil structure and function bring unfavorable conditions for normal life. Soil deformation and loss of functional activity is caused by the interference of xenobiotics (human-made) chemicals or other alternations in the natural soil environment. This is mainly due to industrial activity, agricultural chemicals or raw wastes emerging from regular household activity, or to the influx of sewage into nature. Besides this, the most common chemicals involved are petroleum hydrocarbons, polynuclear aromatic hydrocarbons (such as naphthalene and benzopyrene), solvents, pesticides, and heavy metals. The main concern regarding soil contamination is primarily the health risks, either through direct contact with contaminated soil, vapor from contaminated soil, or from secondary contamination of water from soil for day-to-day works. In developed countries like those in North America and Western Europe, the land is under the direct supervision of environmental regulatory acts. So, most lands are demarked under environmental regulatory acts. But in developing countries like China and India there are less tight environmental regulatory acts for controlling industrialization and urbanization. Remediation and reclamation of contaminated soil from sewage sludge, pesticides application, industrial waste, radioactive materials, etc., are complicated

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tasks due to numerous social, political, economic, and environmental regulatory acts. Since the mid-1980s, concern about terrestrial ecology with respect to privatization of land has created a herculean task of resolving issues related to the recovery of contaminated land.

4.1 Major soil pollutants Basically, the origin of land is due to the slow deposition of residue aroused due to the physical and chemical weathering of bedrock over thousands of years. The thin top cover on Earth’s land surface is due to the decayed remains of plants and animals. The safe and secure persistence of soil is necessary for agriculture and the production of sufficient food [3]. Soil being a “universal sink” bears the greatest burden from environmental pollution. Mainly two types of soil contamination occur, namely manmade and natural. There is urgency in controlling soil pollution in order to conserve its structure, and saving biodiversity by controlling soil fertility and water retaining capacity. Mainly agriculture depends on the quality of soil of a particular geographic location. Both the human and animal kingdoms depend on crops and other domestic animals as primary sources of food. But this natural resource is being damaged by human activity. So, it is high time to have control over the input of the enormous quantity of manmade waste products, sludge, and other products that threaten the life of the planet. The irresponsible attitude of humans contributes majorly to land pollution. Humans have caused contaminated soil to pass on pollutants to the food chain and to reach top consumers through autotrophs or soil animates. The process of the movement of pollutants from soil to top consumers is known as biomagnification. In this process, toxic chemicals like pesticides, heavy metals, or polychlorinated biphenyls (PCBs) present in the soil move through the food chain to top consumers like birds, snakes, mammalians, animals, and human beings (Fig. 4.3).

4.1.1 Manmade Anthropogenic soil pollution may be due to the disposal of untreated household wastes or it may be accidental. Various environmental factors may cause manmade pollution to accelerate by multiple magnitudes. Manmade pollution compromises the environment at the cost of risk to human life. Manmade pollution is generally a byproduct of human activity such as wastes disposal, mismanaged industrial activity, transport, and energy generation. 1. Accidental spills and leaks Land is prone to hazardous materials and substances that have the potential to harm human life and the environment. The main sources of hazardous materials are industrial chemicals and pesticides used for

4.1 Major soil pollutants

FIGURE 4.3 Biological accumulation/ magnification process of toxic materials in interlinked food web chain

agricultural practices. Spills of hazardous materials result from the careless handling of containers having hazardous solids, powders, and liquid solvents. About 800,000 hazmat shipment transit shipment occurs per day. This was an official report from the US Department of Transport Pipeline and Hazardous Materials Safety Administration, 2017. In addition, this report says that about

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3391 incidents of hazmat spill occurred in 2017 (www.airseacontainers.com). Details on soil pollution due to oil spills have been given in Chapter 1 Section 1.1.9.1.1. 2. Soil contamination due to wastes disposal The mismanagement of handling and disposing chemical wastes from industry into nature alter the structure and function of soil. Sewage and municipal wastes contain a variety of hazardous chemicals harmful for both soils and marine systems [4,5]. Mostly it comes from agricultural effluent from animal husbandry and the drainage of irrigation water and urban runoff. Sewage water irrigation causes heavy damage to soil structure and function. Physical changes like leaching, changes in humus content, and porosity, and chemical changes such as soil reaction, base exchange status, salinity, and the quantity and availability of nutrients like nitrogen, potash, phosphorus, etc., are mainly caused due to soil contamination. The input of sewage sludge into the soil gets accumulated with toxic metals like lead, nickel, zinc, cadmium, etc., and is responsible for phytotoxicity in plants [2,6]. Organic wastes are also rich in borates, phosphate, detergents, and phenols. If untreated they will affect the vegetative growth of plants and beneficial microflora. Asbestos, combustible materials, and gases like methane, carbon dioxide, hydrogen sulfide, carbon monoxide, and sulfur dioxide are also indirectly accumulated in soil. Radioactive materials like uranium, thorium, strontium, etc., also cause dangerous soil pollution. The fallout of strontium mostly remains in soil and is concentrated in the sediment [7]. 3. Pesticides Before World War II, nicotine from tobacco plants was applied to control pests in agriculture. Subsequently, dichloro diphenyl trichloroethane (DDT) gained popularity to control Malaria and pests. During the post-war period, people started using DDT widely to control rodents, weeds, insects, etc. But soon the harmful effect of this chemical was realized, which ultimately led to the banning of this chemical in many parts of the world. As the result of such a consequence, less-persistent, organic, and more-biodegradable substances such as carbamates and organophosphates were introduced in the market. Currently, the use of pesticides is common to control several types of pests. Pesticides control pests, but are harmful to microorganisms, which support the growth and development of plants. Prolonged accumulation of pesticides in soil is toxic to soil flora and fauna. Residual pesticides in the soil move to plants or crops through water and ultimately get into the food chain. Aromatic organic pesticides, due to their prolonged half-life period, persist in the soil, for years even (Table 4.1). Besides killing target pests, pesticides also damage the structure and function of soil. Mainly, pesticides damage the microflora of soil, particularly when these chemicals are overused or misused. However, contradictory

4.1 Major soil pollutants

Table 4.1 Persistence time for some select pesticides. S. No.

Nature of particles

Persistence time

1 2 3 4 5 6 6 6 9

BHC Dichloro diphenyl trichloroethane 2,4-D Aldrin Diuron Atrazine Simazine Chlordane 2,3,4-Trichlorobenzene

11 years 10 years 2 8 weeks 9 years 16 months 18 months 17 months 12 years 2.5 years

reports also appear on the beneficial effects of pesticides as some microbes have the potential to degrade pesticides and also to assimilate them [8]. The effect of pesticides on soil microorganisms is influenced by the persistence, concentration, and toxicity of the applied pesticide, and the prevailing soil structure related to the surrounding environmental conditions [9]. So, it is unwise to draw any final conclusions on the interactions of pesticides with soil ecosystems. However, long-term exposure of pesticides can alter the structure and function of soil [10,11]. Besides this, soil conservation can be hampered due to the long-term persistence of contaminated soil [12,13], and may also be responsible for decreased biodiversity. Avoiding the overuse of pesticides may increase the water holding capacity and other qualities of soil, which would be favorable for the survival of plants, microflora, and productivity [14]. Mainly, the persistence of pesticides in soil is dependent on degradation and sorption in the soil. This process is regulated by the chemical nature and half-life of pesticides. Such processes control the transportation from soil to water, and, in turn, to air and food. Proper interaction of microorganisms in soil result in the degradation of organic matter in the soil. So, it is necessary to perform quick soil remediation by physical, chemical, or biological processes [15]. 4. Inorganic toxic compounds Discharge from industry contains both organic and inorganic hazardous materials [16]. The nature of pollutants from industry are mainly dependent on the types of industry and manufacturing processes. The major pollutants from industry include heavy metals like copper, mercury, cadmium, lead, nickel, and arsenic, sulfur dioxide from thermal plants and other plants, fluorides in the atmosphere from superphosphate, phosphoric acid, aluminum, steel, and ceramic industries that return to the land surface through rain, copper and mercury from fungicides, and smoke from automobiles containing lead, which gets adsorbed by soil particles [17] causing the deformation of

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soil structure and function by increasing acidity and damaging soil flora and fauna. Heavy metals are of high density ( . 5). Generally, heavy metals bind on inorganic or organic colloids. They are widely distributed in the environment, soil, plants, and animals, in their tissues. Still, heavy metals are essential for plants and animals in trace amounts. Mainly, the sources of heavy metals are urban and industrial aerosols, the combustion of fuels, liquids and solids from animals and human beings, mining wastes, and industrial and agricultural chemicals. In agricultural soil, the magnitude of heavy metal concentrations increases with the application of pesticides, sewage sludge, farm slurries, etc. 5. Radioactive pollutants Nuclear power plants, explosive devices, atomic tests, and atomic activities in laboratories are main sources of radioactive pollutants. Radiation106, Rhodium-106, Iodine-131, Barium-40, Lanthanum-40, and Cerium-144 are a few pollutants commonly known to contaminate soil due to improper handling. These radionuclides emit gamma radiations, which are harmful to soil flora and fauna. 6. Mining and smelting Mining and smelting processes are responsible for some of the largest releases of heavy metals in the nature. In addition, they also release other hazardous air pollutants like sulfur oxide and nitrogen with tons of waste tailings, slags, and acid drainages. The smelting process involved in the extraction of metals from ore is associated with the highest exposures and environmental releases of heavy metals. Mainly, lead, cadmium, and mercury are the primary pollutants that leach during the smelting process. Besides this, the erosion of exposed soils, extracted mineral ores, tailings, and fine materials in waste rock piles can result in substantial sediment loading in surface waters and drainage pathways. Due to continuous and prolonged exposure to heavy metals, mining workers suffer from a range of neurological deficits in both children and adults. Exposure to airborne silica and asbestos can cause lung cancer, pneumoconiosis, and numerous other health problems. For example, in 2010, more than 400 children were dead in Zamfara and Nigeria due to acute lead toxicity by unsafe mining and the processing of lead-containing gold ore. Generally, people grind lead-containing gold ore at home as a part time job. This sort of unfair practice at home has led to lead contamination in over 180 villages. 7. Acid rain Industries such as chemical processing units, fertilizer generation, crude oil distillation, the burning of fossil fuels, sugar factories, the textile industry, cement factories, graphite manufacturing units, metal fabrication units, etc., are responsible for soil pollution. Effluent discharge from all these industries gets into the soil system, and over time, with interactions with soil microflora or decomposition, oxides of nitrogen, sulfur, and carbon are released into the

4.1 Major soil pollutants

atmosphere. Ultimately these gases interact with atmospheric water vapor and are responsible for acid rain. Acid rain damages the basic properties of soil necessary for vegetation or crop cultivation. 8. Soil erosion The natural process of soil erosion results from interactions between the forces of gravity, air, water, and the loss of vegetation coverage. Some of the principal causes of soil erosion include rain and rain water runoff, mismanaged farming, sloping land, lack of vegetation, and wind. The main issue of soil erosion is its uncertainty. This process may be slow or quick depending on the weather or climatic changes. It can be a slow process that isn’t noticeable. However, the occurrence of severe weather conditions or other causes can contribute to rapid soil erosion, which greatly harms the area and its inhabitants. Soil erosion brings the loss of topsoil, soil compaction, reduction in organic components, poor drainage, and loss of plant and animal diversity.

4.1.2 Natural causes of soil pollutants Mainly, volcanic eruptions, alterations in rainfall patterns, earthquakes, geographical changes, air pollution, and the melting of glaciers are primary causes of natural soil pollution. 1. Volcanic eruption Volcanic activity is the best example of a nonanthropogenic source of pollution. During volcanic eruptions huge quantities of greenhouse gases and other aerosols are released into the atmosphere. The hazardous gases get accumulated in the sky as massive clouds. This process of accumulation of gasses is known as outgassing or offgassing. Volcano gases are emitted in a complex form of gas consisting of water vapor (H2O), carbon dioxide (CO2), sulfur dioxide (SO2), hydrogen sulfide (H2S), carbon monoxide (CO), hydrogen chloride (HCl), and hydrogen fluoride (HF). This combination of outgas particulates have tremendous detrimental impacts on the land and sea. Sulfur dioxide released during volcanic eruptions combines with water vapor in the atmosphere, causing acid rain on a global scale. In 1883, the volcanic eruption of Krakatau in Indonesia caused outgas aerosol particulates to be dispersed all the way to New York, 13 days after this volcanic eruption. Volcanic clouds act as barriers to solar radiation and cause decreases in the Earth’s surface temperature, which may take about five years to return to normal. 2. Earthquakes and tsunamis Earthquakes can cause damage to land, air, and waterbodies. The 2008 Sichuan earthquake in China caused the collapse of civilian structures, roads, bridges, and factories. The collapse of factories, in particular, caused great disaster by the subsequent release of chemicals and gases stored in huge tanks, and resulting in soil, water, and air pollution. In 2004, the Sumatra

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earthquake caused a massive tsunami in the Indian Ocean, causing saltwater contamination of drinking water, and millions of acres of farmlands were contaminated with saltwater. It was difficult and highly expensive to make the land once again suitable for crop development. Japan’s 2011 earthquake and tsunami caused a nuclear power plant to fail, and radiation to leak into the ocean and escape into the atmosphere. 3. Flood Flooding resulting from large rivers causes damage to nearby industries, which is ultimately responsible for the exposure to harmful effluents, chemicals, and gases of nature. Fertilizers from crop fields and hazardous chemicals from chemical processing units are swept downstream and deposited on land. Freshwater ecosystems including dams get contaminated with wastes and harmful chemicals, thus, making drinking water unfit for consumption and use. Crop lands then become unfit for many years for cultivation due to changes in the physical and chemical properties of soil. The addition of excess nutrition or the depletion of soil fertility causes the growth of aquatic weeds and algal blooms. Besides this, the soil flora and fauna that support the growth and development of vegetation get lost.

4.2 Soil quality management Environmental monitoring and conservation have been burning issues for the past few decades. Environmental factors such as climate change, dwindling water resources, and threatened habitats are emerging issues that fuel the urgency of monitoring the environment, especially the land. As discussed previously in this chapter, many natural and manmade factors interfere with the qualities of soil that make it favorable for agricultural practice, vegetation, and biodiversity. It was noticed that soil quality management improves infiltration, aeration, and biological activity, which could lead to significant gains in crop yields. Among the factors important for soil quality management are soil moisture, water holding capacity, porosity, microbial consortium, soil stability, and pH.

4.2.1 Moisture Moisture levels are dependent on soil type. Clay soil has a poor moisture penetration property due to its compact nature. Loose and sandy soils drain quickly and need timely irrigation for maintaining moisture. Loam soil is rich in organic matter and has a high moisture retention capacity. Soil moisture can be improved by the addition of a suitable quantity of compost, peat, and other organic matter to the soil before plantation. The cheapest way to maintain soil moisture is to shield the soil’s surface with mulch. Mulching is the practice of covering the soil’s surface with straw or

4.2 Soil quality management

compost for the prevention of excessive soil moisture evaporation. A mulched bed still requires irrigation to replenish the moisture in the soil as plants use it. Plastic and landscape fabric are also used as synthetic mulch. The former is used to prevent both weed growth and soil moisture evaporation in excessive quantities. Whereas the latter is used for preventing weed growth. The only drawback with plastic mulching is the prevention of rain water entry into the soil. So, it is advisable to use perforated plastic sheeting in a drip irrigation process. Generally, soil needs water when the top one inch gets dry. Soil watering should be maintained early in the day so the moisture can penetrate the soil before it can evaporate.

4.2.2 Enhance organic matter On farms, the primary sources of organic matter are plant litter (plant roots, stubble, leaves, and mulch) and animal manures. Earthworms (EWs) and microorganisms decompose these materials. The process of decomposition releases nutrients that support crop/plant growth and development. EWs are beneficial to soil because they can enhance soil nutrient cycling through the rapid incorporation of detritus into soils. The mucus production accompanied by water excretion in EWs’ guts support soil microorganism activity. Due to such activity, large quantities of nutrients (N, P, K, and Ca) become available to plants. EWs are well recognized for their role in nitrogen mineralization through direct and indirect effects on the microbial community. Generally, soil organic matter is added every year to maintain sustainability in organic matter available to agricultural crops. The regular addition of organic matter on a monitoring basis improves soil structure, enhances water and nutrient holding capacity, protects soil from erosion and compaction, and maintains microbial consortia, thereby supporting the growth and development of plants/crops. The practice of leaving crop remains after harvest, crop rotation, using optimum nutrients and proper water management practices, growing cover crops, applying manure or compost in a timely fashion, using no tillage systems, growing perennial forage crops, and mulching help in enhancing soil organic contents.

4.2.3 Avoid excessive tillage Tillage is a practice used to loosen the soil’s surface, prepare seedbeds, and control weeds and pests. But tillage can break up the soil structure, speed the decomposition and loss of organic matter, and make the soil prone to erosion. Tillage also reduces crop residues, which help cushion the force of pounding raindrops.

4.2.4 Manage pests and nutrients efficiency The most important function of soil is to buffer and detoxify chemicals and excess fertilizers. Soil buffering stops nutrient or pH changes by absorption.

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The buffering effect of soil is also helpful in releasing ions and absorbing nutrients. In spite of the beneficial effects of pesticides and inorganic fertilizers, they target microorganisms that support the growth and development of crops and other vegetation. Relative acidity or alkalinity is measured by pH. pH indicates the hydrogen ion concentration of soil water. Hydrogen ion is an acid cation. Increases in the concentration of hydrogen ions result in the reduction of pH. The concentration of hydrogen ions in the soil solution is directly proportionate to and in equilibrium with the hydrogen ions retained in the soil’s cation exchange complex. Thus hydrogen ions retained by clay particles replenish or buffer the hydrogen ions in water.

4.2.5 Prevent soil compaction Soil compaction is the process of the densification of soil by the application of a stress. In this process, air from the soil is displaced from the pores between the soil grains. But when water is displaced due to any stress, the process is known as consolidation. Soil compaction occurs due to compression by heavy machinery on the soil’s surface or due to the passage of animals. From a soil sciences and agronomy point of view, soil compaction is usually a result of both engineering compaction and consolidation. This may be due to a lack of water in the soil, the applied stress being internal suction as the result of water evaporation. Soil compaction increases soil density, reduces porosity, and results in increases in penetration resistance and degradation of the soil structure. The tillage of soil breaks compacted soils and provides aeration. The increase in the application of heavy machineries has dramatically increased soil compaction. Besides this, tillage also has negative effects on soil compaction. Tillage can alleviate the effect of topsoil compaction on sandy soil. The effect of topsoil compaction reduces yields, in spite of tillage. Subsoil compaction is below the depth of normal tillage operations. Subsoil compaction cannot be rectified by freeze thaw and wetting drying cycles on any soil type. The effects of subsoil compaction are due to the use of high axle loads (10 tons and heavier) on wet soil and are noticed in all types of soil including sandy soil.

4.2.6 Coverage of ground The loss of one millimeter of topsoil is equivalent to 10 tons of soil per hectare. This loss is supposed to take thousands of years to be replaced through the weathering of parent materials. Bare soil is prone to climate changes, water flow, and erosion. Well protected land provides habitats for flora and fauna including microbial consortia that support the growth and development of plants. It is essential to maintain at least 70% ground cover for low slopes and up to 100% on steep areas to protect soil from erosion. This will reduce the soil damage caused by runoff, particularly under high-intensity storm rain, and improve the

4.2 Soil quality management

FIGURE 4.4 Geotextile sand bags used for soil erosion.

water quality. Reducing surface runoff minimizes the risk of erosion. But some runoff is essential to provide water streams to dams and farms. Ground can be covered by leaving crop residues on the surface or by planting cover crops. Cover crops such as vetch, rye, and clove are excellent plants for erosion control. These hardy and easy to grow plants spread nets of roots that help hold topsoil in place while also reducing competitive weeds. So, the simplest and most natural way to prevent erosion is through planting vegetation. Plants establish root systems, which stabilizes soil and prevents soil erosion. Geotextiles are the best materials to be used for soil coverage. Geotextiles are permeable fabrics. These can be used in association with soil to facilitate the ability to separate, filter, reinforce, protect, or drain. They are made from polypropylene or polyester (Fig. 4.4).

4.2.7 Diversity management by multiple cropping Multiple cropping is beneficial for several reasons. Each plant has their own unique root system for holding soil. Root networks prevent soil from being blown or washed away. Tree roots also protect the soil structure because root growth breaks up soil to create space for air and water, which improves aeration and drainage. Nutrients are added to the soil from the tree roots. Diversified soil organisms can be helpful in controlling pest populations. Soil organisms live in close proximity and use organic matter as a source of carbon. The activity of soil microbes not only support plant growth, but are also helpful in managing soil structure and function. The practices of buffer strips, small fields, or control strip cropping help in land management (Fig. 4.5).

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FIGURE 4.5 Crop diversity of different localities.

The structure and function of soil is closely linked with the culture and civilization of a given ethnic group of a particular geographical location. This is also closely related to their religion, thoughts, and lifestyle. Because, the survival of normal life depends on agricultural productivity and environmental conservation. So, a close link exists between the soil and culture, civilization, livelihood, and health. This could only be possible due to the ethical attitudes people possess about soil resources.

4.3 Control of soil pollution Soil contamination occurs due to the interference of hazardous chemicals such as pesticides, ammonia, petroleum hydrocarbons, and heavy metals emerging from human activity. The primary cause of such issues is a lack of awareness on the adverse effects of pollutants on human life and ecosystems. It is better to take preventive measures for avoiding soil pollution than to spend billions of dollars for soil remediation. However, due to certain unavoidable circumstances, nature gets contaminated with a variety of pollutants and this threatens the continuity of habitable life on Earth. Various physical, mechanical, and chemical remediation techniques (Fig. 4.6) commonly used for contaminated soil are extraction, pump-and-treat, stabilization/ solidification, soil washing, air stripping, precipitation, vitrification, thermal desorption, and biological remediation (Fig. 4.7). Some important techniques presently in use are thermal remediation, encapsulation, air sparging, in situ oxidation, and bioremediation. Section 1.9.1.1 of Chapter 2 covers these issues in detail.

FIGURE 4.6 Various physical, chemical, and biological methods used for contaminated soil management. Adapted from Sanahhlid MS, Niazi NK, Murtaza B, Bibi I, Dumat C. A comparison of technologies for remediation of heavy metal contaminated soil. J Geochem Explor 2017;182:247 68 [18].

FIGURE 4.7 Various remediation techniques used for heavy metal contamination. Courtesy Koul B, Taak P. Biotechnological strategies for effective remediation of polluted soils. Springer; 2018. p. 59 75 [19].

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4.3.1 Nanoremediation for contaminated soil Nanoremediation is the use of nanoparticles for environmental remediation purposes. It is applicable for soil, groundwater, and wastewater treatment processes [20,21]. This technique was discovered in 2009, and since then it has been documented in at least 44 clean-up sites around the world, predominately in the United States [22 24]. In Europe it is being taken up by the European Commission funded NanoRem Project [25]. In nanoremediation, a nanoparticle agent is brought into contact with the target contaminant under conditions that allow for a detoxifying or immobilizing reaction. This process typically involves a pump-and-treat process or in situ application. Nanoparticles have a highly active surface area per unit mass [22], and due to their extremely small size they can penetrate into small pores in the soil or sediment, and be sorbed to target sites. By Brownian motion, nanoparticles move freely in soil to target sites. The flow of groundwater is enough for the movement of nanoparticles in the soil. Nanoparticles can remain suspended in soil water for a long period and react with target molecules in in situ processes [26]. Nanoparticles either degrade the targeted complex molecule or adsorb to the contaminant to immobilize it. Magnetic nanoiron adsorbed complexes may be separated from targeted molecules (pesticides or organic solvents) by removing the contaminant [27]. Since 2012, nano zero-valent iron (nZVI) coated with palladium, silver, or copper as catalyst has been used for remediation of contaminated soil. These coated nZVI particles are known as bimetallic nanoparticles [3] and have been in use both in laboratory and field tests [21]. This bimetallic nZVI is used for degrading organic contaminants including chlorinated organic compounds such as PCBs and trichloroethene [22,28]. In nonpathological reactions, nZVI is injected below ground into contaminated zones for in situ groundwater remediation.

4.3.2 Immobilization techniques Immobilization techniques are practical approaches for metal contaminated soil. Both ex situ and in situ techniques are used for the remediation of metal contaminated soil. The ex situ immobilization technique is applicable to highly contaminated soils, which is supposed to be removed after remediation and stored elsewhere with high ecological risk. The benefits of this technique are its easily applicable process and that it can be managed with low budgetary provision. Still, this technique has certain limitations due to the generation of enormous amounts of solid wastes, the need for the storage of byproducts with risk, and a proper method of disposal of byproducts is necessary.

4.3 Control of soil pollution

The basic principles of the in situ technique are the same as in the case of the ex situ technique, but selective fixing agents are used for this purpose. The benefits include its low invasive property and it being easy to handle, inexpensive, and socially acceptable. It is a temporary solution having certain drawbacks like reclamation being restricted to the surface layer of the soil, and it needing regular monitoring [29,30]. Immobilization techniques are applicable for organic and inorganic amendment to restrict the mobility of metal and toxic contaminants in soils. In this technique, metals in contaminated soil are brought to geochemically stable phases via sorption, precipitation, and complexation processes [31]. For this purpose the most common and cheap amendments are the use of clay, cement, zeolites, minerals, phosphates, organic compounds, and microbes [32]. Besides this, low-cost industrial residues such as red mud [33,34] and termitaria [35] can be best used for heavy metal remediation of soil. The technical reasons for such immobilization by the mentioned materials are not yet clear, but is assumed that precipitation, chemical adsorption and ion exchange, surface precipitation, the formation of stable complexes with organic legends, and redox reaction may be responsible for heavy metal immobilization in the remediation of soil [36]. The in situ immobilization process is less expensive with lower labor and energy requirements, while the ex situ method is expensive and tedious.

4.3.2.1 Solidification Solidification is a technique that involves the binding of contaminated materials to structurally stabilize the heavy metal contaminated soil and restrict it mobility. This is done by bringing contaminates to a solidified form and seizing their mobility. This is mainly carried out by encapsulation [37]. The process of encapsulation is given in detail in Section 1.9.1.1 of Chapter 1. It is a well-known technology for soil heavy metal and other hazardous contamination in many parts of the world [38]. Mostly, clay (bentonite and kaolinite), charcoal, cement, fly ash, blast furnace slag, calcium carbonate, Fe/Mn oxides, zeolite [39], and organic stabilizers such as bitumen, compost, and manure [40], or a combination of organic and inorganic amendments may be used. The mechanisms by which such solidification occurs are immobilization and precipitation of hydroxides within the solid matrix [41,42]. This technique is not applicable for metals such as species that 2 exist as oxyanions (e.g., Cr2 O22 7 , AsO3 ) or metals that do not have low-stability hydroxides (e.g., Hg).

4.3.2.2 In situ vitrification for soil remediation In situ vitrification (ISV) is a treatment technology that uses electricity to heat contaminated soil sufficiently to produce an inert glass-like product. It can be applied both in situ and above ground in a treatment unit (ex situ). Organic contaminants are destroyed by pyrolysis or they are stripped out of the soil with the escaping steam and trapped in an off-gas treatment system (Fig. 4.8).

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FIGURE 4.8 In situ soil remediation by vitrification. Courtesy Koul B, Taak P. Biotechnological strategies for effective remediation of polluted soils. Springer; 2018. p. 59 75 [19].

4.3.2.2.1 In situ vitrification In the ISV technique, by means of electricity, soil is melted at 1600 C. In this process, the contaminated soil is melted to glass-like beds that start near the ground surface and move down. With the progress of the melting process, electrodes sink further into the ground, causing deeper soil to melt. Once the electrodes are disconnected, the melted soil gets cool and vitrifies. The vitrification process causes the ground surface in the area to sink slightly. The sunken area is filled with clean soil. The soil contaminants are trapped in the vitrified block, which is left in place. The vitrification product is a chemically stable inner crystalline material like basalt rock. Both volatile and organic contaminants are destroyed in this process. By means of a vacuum hood, the off-gases of the treated soil are removed.

4.3.2.2.2 Ex situ vitrification Ex situ vitrification is like ISV, except that it is done inside a chamber. Plasma torches or electric furnaces are used as heating devices. A rotary hearth having the provision of a plasma torch is loaded with contaminated soil. In the operation process, the waste and molten materials are held against the side by centrifugal force. The molten materials are removed by slowing down the hearth rotation and slag flow through a bottom opening. Effluent gases are generally kept in a separate container where high temperatures oxidize the contents. Advance-type

4.3 Control of soil pollution

furnaces have the provision of carbon electrodes, cooled sidewalls, a continuous feed system, and an off-gas treatment system.

4.3.3 Soil washing Soil washing is an ex situ remediation technique that removes hazardous contaminants from soil by washing the soil with liquid containing chemical additives, scrubbing the soil, and then separating the clean soil from the contaminated soil and wash water. It is often used in conjunction with other physical separation techniques. The soil washing process is carried out to separate soil by particle size. Inorganic and organic contaminants bind to clay, silt, and organic soil particles. Most silts and clays are stuck to larger particles (i.e., sand and gravel). Washing separates the small particles from the larger particles by breaking adhesive bonds. Acid and chelator soil washing are the most common methods used for remediating contaminated soil [43]. In the in situ process, contaminated soil is subjected to flushing by forcing a washing solution through the in-place soil matrix. The ex situ process is carried out in a reactor having the provision of an influx of washing solution. In some cases, electroremediation is done. It involves the electrokinetic movement of charged particles suspended in the soil solution, initiated by an electric gradient [44]. The metal is removed by precipitation at electrodes. Soil contaminated with both metals and organic compounds may not be separated with a single washing. In this case, sequential washing, using different wash formulations may be required. Wash water requires proper treatment before it is discharged into nature or recycled. Soils contaminated with volatile organic matter need special types of emission controls. Soil washing systems are used for contaminated soil having volatile organic compounds (VOCs), fuel, and heavy metals including radionuclides. This technique can also be used on selected VOCs and pesticides. Thus for soil washing to be successful, the level of contamination in the treated bulk must be below a sitespecific action limit based on risk assessment. Several types of chemicals are recommended for soil washing water formulations. Chemicals used for soil washing include surfactants, cosolvents, cyclodextrins, chelating agents, and organic acids [45 50]. The formulation of soil washing water suspension depends on the type of contaminants present and the location of the place. Often strong acid water washing damages the soil’s crystalline structure and contact time. So it is better to go for soil washing with a mild acidic water suspension in combination with other additives like chelating agents [51]. Generally, oxalic, citric, formic, acetic, succinic, malonic, lactic, aconitic, and fumaric acids are natural products of root exudates, microbial secretions, and plant and animal residues decomposed in soil [52]. These acids are better options for the formulation of soil washing water mixtures [53]. Chelating organic acids are helpful in dislodging the exchangeable, carbonate, and reducible fractions of heavy metals by the washing process [43]. Many chelating compounds such as

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citric acid [50], tartaric acid [54], and EDTA [43,55,56] can be used for mobilizing heavy metals, but their application in optimized conditions is still uncertain. Soil washing is used extensively in Europe. However, commercial soil washing techniques have restricted use.

4.4 Regulatory aspects of soil pollution control 4.4.1 International law for soil protection There are three main international treaties that are relevant to soil protection, namely the United Nations Convention to Combat Desertification (UNCCD) of 1994, the Convention on Biological Diversity (CBD) of 1992, and the United Nations Framework Convention on Climate Change (UNFCC) of 1992. The main aims of the Desertification Convention are to combat desertification and to mitigate the effects of drought. The preservation and sustainable use of biological diversity are covered in the Convention on Biological Diversity of terrestrial ecosystems. The Climatic Framework Convention explains the agreements on mitigation and adaptation measures, which include greenhouse gas sinks and reservoirs. In addition, as per Alpine Convention held on 1991, there are also regional laws for soil conservation. The three main international treats are as follows: 1. Convention to Combat Desertification In 1994, the UNCCD was signed as the sole legally binding international agreement linking the environment and development to sustainable land management. The convention addresses specifically arid, semiarid and dry subhumid areas, known as drylands, where some of the most vulnerable ecosystems and peoples can be found. The new UNCCD 2018 2030 Strategic Framework is the most comprehensive global commitment to achieve Land Degradation Neutrality (LDN) in order to restore the productivity of vast expanses of degraded land, improve the livelihoods of more than 1.3 billion people, and reduce the impacts of drought on vulnerable populations. The UNCCD aims to solve the root cause of the issue with local participants in combating desertification and land degradation. 2. The Convention on Biological Diversity The CBD, also known as the Biodiversity Convention, is a multilateral treaty having three main objectives including the conservation of biological diversity (or biodiversity), the sustainable use of its components, and the fair and equitable sharing of benefits resulting from genetic resources. The convention was opened for signature at the Earth Summit in Rio de Janeiro June 5, 1992, and entered into force on December 29, 1993. The CBD has two supplementary agreements, namely the Cartagena Protocol and the Nagoya Protocol. The former is based on biosafety as an additional agreement

4.4 Regulatory aspects of soil pollution control

to the CBD, and in the latter emphasis is placed on access to genetic resources and the fair and equitable sharing of benefits arising from their utilization (ABS). 3. United Nations Framework Convention on Climatic Change The UNFCC is an international environmental treaty adopted on May 9, 1992, and that entered into force on March 21, 1994. The aim of the UNFCC is to bring stability to greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. The framework sets nonbinding limits on greenhouse gas emissions for individual countries without any enforcement.

4.4.2 European law The Directive on Industrial Emissions, the Waste Framework Directory, and the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) Regulation, in particular, contain provisions related to soil protection. In 2010, European Parliament and the Council on industrial emissions (the Industrial Emission Directive or IED) framed and introduced the main instrument regulating pollutant emissions from industrial installations. The IED entered into force on January 6, 2011 and was transposed by member states in 2013. The IED aims to achieve a high level of protection of human health and the environment from harmful industrial emissions across the European Union. The Waste Framework Directory was introduced to address the impacts of the generation and management of waste on the environment and human health and for ensuring the efficient use of resources, which are crucial for the transition to a circular economy. In 2015, the European Union adopted an action plan for a circular economy, and the revised Waste Framework Directive entered into force in July 2018. REACH is an EU regulation dating from December 18, 2006. REACH addresses the production and use of chemical substances, and their potential impacts on both human health and the environment. REACH is applicable to all chemical substances, not only those used in industrial processes, but also in our day-to-day lives, for example, in cleaning products and paints as well as in articles such as clothing, furniture, and electrical appliances. Prior to 2006, few EU member states had specific legislation on soil protection. So, it was not subject to a comprehensive and coherent set of rules in the Union. The existing EU policies in areas such as agriculture, water, waste, chemicals, and presentation are indirectly linked with the protection and conservation of soil. On September 22, 2006, the European Union adopted the Soil Thematic Strategy (COM(2006)231) to protect soils across the European Union. In May, 2014, the commission decided to with draw the proposal for the Soil Framework Directive, the seventh Environmental Action Program, which was entered into force on January 17, 2014, recognizing that soil degradation is a serious challenge. It has the provision to bring sustainability into land management by 2020.

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In addition, it is suggested that an adequate action plan should be taken to reduce soil erosion, to increase soil organic matter, and to remediate contaminated sites.

4.4.3 National law On February 29, 1936, US federal law allowed the government to pay farmers to reduce production so as to conserve soil and prevent erosion. The Federal Soil Protection Act and Federal Soil Protection and Contaminated Sites Ordinance aim to sustainably secure or restore soil function. The broader spectrum of these acts include the presentation of harmful soil changes, the rehabilitation of the soil of contaminated sites and of water contaminated by such sites, and taking precautions against negative soil impacts. Emphasis is also given on the soil disruption rather than giving important to archive of natural and cultural history. The Federal Soil Protection Act of March 17, 1998 (BBodSchG), is only applicable when other legislation like the Fertilizer Act or urban planning and building laws do not regulate the effects on soil condition. The detailed provisions concerned are listed in Article 3 of the BBodSchG. The primary focus of the BBodSchG is the rehabilitation of contaminated sites. The resolution acts explain precisely the evaluation of contaminated sites and decision making processes. In addition, the BBodSchG also prescribes the necessary steps to be met in precautionary soil protection.

4.4.4 Building law and regional planning law Building law and regional planning law also have the provision of soil protection and conservation. On the basis of Section 1a, the Federal Building Code states that “land shall be used sparingly and with due consideration.” This principle must be taken into account in urban planning in particular. Regional planning law contains information regarding overall area planning and the use of land and soil.

4.4.5 Close Cycle Management Act Waste management regulations such as those in the Close Cycle Management Act of February 24, 2012, which entered into force on June 1, 2012, have significant value for soil protection. Sewage Sludge Ordinance and Ordinance on Biowaste are also relevant in this context. The legal regulations regarding waste contain guidelines for environment-friendly recycling and disposal of waste.

4.4.6 Nature conservation law The federal Nature Conservation Act (BNatSchG) aims to place restrictions on interventions in nature and landscapes for their conservation and protection. Article 15 (7) of the BNatSchG states that a statutory ordinance can regulate the details of offsetting intervention.

References

The overall target of this act is to conserve, preserve, and develop nature and landscapes, both in populated and nonpopulated areas, which will be helpful in maintaining ecological balance, preserving the exploitability of nature, conserving fauna and flora, and safeguarding the variety, and particularly the beauty, of nature and landscapes.

References [1] Jordan AJ, Adelle C, editors. Environmental Policy in the European Union: Contexts, actors and policy dynamics (3e). London and Sterling, VA: Earthscan; 2012. [2] Swartjes FA. Risk-based assessment of soil and groundwater quality in the Netherlands: standards and remediation urgency. Risk Anal 1999;19:1235 48. [3] Belluck DA, Benjamin SL, Baveye P, Sampson J, Johnson B. Widespread arsenic contamination of soils in residential areas and public spaces: an emerging regulatory or medical crisis? Int J Toxicol 2003;22:109 28. [4] Tarazona JV, Fernandez MD, Vega MM. Regulation of contaminated soils in Spain. J Soil Sediment 2005;5:121 4. [5] Evans J, Wood G, Miller A. The risk assessment-policy gap: an example from the UK contaminated land regime. Environ Int 2006;32:1066 71. [6] Crane M, Giddings JM. ‘Ecologically acceptable concentrations’ when assessing the environmental risks of pesticides under European Directive 91 414/EEC. Hum Ecol Risk Assess 2004;10:733 47. [7] Nathanail P, McCaffrey C, Earl N, Forster ND, Gillett AG, Ogden R. A deterministic method for deriving site-specific human health assessment criteria for contaminants in soil. Hum Ecol Risk Assess 2005;11:389 410. [8] Li J, Zhou B, Liu Y, Yang Q, Cai W. Influence of coexisting contaminants on bisphenol A sorption and desorption in soil. J Hazard Mater 2008;151:389 93. [9] Gennings C, Carter Jr WH, Casey M, Moser V, Carchman R, et al. Analysis of functional effects of five pesticides using a ray design. Environ Toxicol Pharmacol 2004;14:115 26. [10] Hussain S, Siddique T, Saleem M, Arshad M, Khalid A. Chapter 5: Impact of pesticides on soil microbial diversity, Enzymes, and biochemical reactions. Adv Agron 2009;102:159 200. [11] Abdel-Mallek AY, Moharram AM, Abdel-Kader MI, Omar SA. Effect of soil treatment with the organophosphorus insecticide Profenfos on the fungal flora and some microbial activities. Microbiol Res 1994;149(2):167 71. [12] Sources of common contaminants and their health effects. Emergency Response Program. EPA. Archived from the original on 2008-12-20. Retrieved October 10, 2007. [13] Johnston AE. Soil organic-matter, effects on soils and crops. Soil Use Manag 1986;2 (3):97 105. [14] Lotter DW, Seidel R, Liebhardt W. The performance of organic and conventional cropping systems in an extreme climate year. Am J Altern Agric 2003;18 (3):146 54. [15] Arias-Este´vez M, Lo´pez-Periago E, Mart´ınez-Carballo E, Simal-Ga´ndara J, Mejuto JC, Garc´ıa-R´ıo L. The mobility and degradation of pesticides in soils and the pollution of groundwater resources. Agric Ecosyst Environ 2008;123(4):247 60.

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[16] Richardson GM, Bright DA, Dodd M. Do current standards of practice in Canada measures what is relevant to human exposure at contaminated sites? II: Oral bioaccessibility of contaminants in soil. Hum Ecol Risk Assess 2006;12:606 18. [17] Van Zorge JA. Exposure to mixtures of chemical substances: is there a need for regulations? Food Chem Toxicol 1996;34:1033 6. [18] Sanahhlid MS, Niazi NK, Murtaza B, Bibi I, Dumat C. A comparison of technologies for remediation of heavy metal contaminated soil. J Geochem Explor 2017;182:247 68. [19] Koul B, Taak P. Biotechnological strategies for effective remediation of polluted soils. Springer; 2018. p. 59 75. [20] Crane RA, Scott TB. Nanoscale zero-valent iron: future prospects for an emerging water treatment technology. J Hazard Mater 2012;211 12. [21] U.S. EPA. Nanotechnologies for environmental cleanup; 2012. [22] Karn B, Kuiken T, Otto M. Nanotechnology and in situ remediation: a review of the benefits and potential risks. Environ Health Perspect 2009;117(12):1823 31. [23] Project on emerging nanotechnologies. Nanoremediation Map. Retrieved November 11, 2013. [24] Mueller NC, Braun J, Bruns J, ern´ık M, Rissing P, Rickerby D, et al. Application of nanoscale zero valent iron (NZVI) for groundwater remediation in Europe. Environ Sci Pollut Res 2012;19(2):550 8. [25] Nanotechnology for contaminated land remediation. Retrieved December 3, 2014. [26] Zhang W, Cao J, Elliot D. Iron nanoparticles for site remediation. In: Karn B, Masciangioli T, Zhang W, Colvin V, Alivisatos P, editors. Nanotechnology and the environment: applications and implications. Washington, DC: Oxford University Press; 2005. p. 248 61. [27] Sa´nchez A, Recillas S, Font X, Casals E, Gonza´lez E, Puntes V. Ecotoxicity of, and remediation with, engineered inorganic nanoparticles in the environment. TrAC Trends Anal Chem 2011;30(3):507 16. [28] Theron J, Walker JA, Cloete TE. Nanotechnology and water treatment: applications and emerging opportunities. Crit Rev Microbiol 2008;34(1):43 69. [29] Martin TA, Ruby MV. Review of in situ remediation technologies for lead, zinc and cadmium in soil. Remediation 2004;14(3):35 53. [30] USEPA. Recent developments for in situ treatment of metal contaminated soils. Tech. Rep. EPA-542-R-97-004. Washington, DC: USEPA; 1997. [31] Hashimoto Y, Matsufuru H, Takaoka M, Tanida H, Sato T. Impacts of chemical amendment and plant growth on lead speciation and enzyme activities in a shooting range soil: an X-ray absorption fine structure investigation. J Environ Qual 2009;38(4):1420 8. [32] Finˇzgar N, Kos B, Leˇstan D. Bioavailability and mobility of Pb after soil treatment with different remediation methods. Plant Soil Environ 2006;52(1):25 34. [33] Boisson J, Mench M, Vangronsveld J, Ruttens A, Kopponen P, De Koe T. Immobilization of trace metals and arsenic by different soil additives: evaluation by means of chemical extractions. Commun Soil Sci Plant Anal 1999;30 (3 4):365 87. [34] Lombi E, Zhao FJ, Zhang G, et al. In situ fixation of metals in soils using bauxite residue: chemical assessment. Environ Pollut 2002;118(3):435 43. [35] Anoduadi CO, Okenwa LB, Okieimen FE, Tyowua AT, Uwumarongie-Ilori EG. Metal immobilization in CCA contaminated soil using laterite and termite mound soil. Evaluation by chemical fractionation. Nigerian J Appl Sci 2009;27:77 87.

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[36] Bhargavi VLN, Sudha PN. Removal of heavy metal ions from soil by electrokinetic assisted phytoremediation method. Intern J ChemTech Res 2015;8:192 202. [37] Wang LQ, Luo L, Ma YB, Wei DP, Hua L. In situ immobilization remediation of heavy metals-contaminated soils: a review. Chin J Appl Ecol 2009;20(5):1214 22. [38] Evanko FR, Dzombak DA. Remediation of metals contaminated soils and groundwater, Tech. Rep. TE-97-01. Pittsburgh, PA: Groundwater Remediation Technologies Analysis Centre; 1997. [39] Fawzy EM. Soil remediation using in situ immobilisation techniques. Chem Ecol 2008;24(2):147 56. [40] Farrell M, Perkins WT, Hobbs PJ, Griffith GW, Jones DL. Migration of heavy metals in soil as influenced by compost amendments. Environ Pollut 2010;158(1):55 64. [41] Bishop P, Gress D, Olafsson J. Cement stabilization of heavy metals: Leaching rate assessment. Industrial Wastes- Proceedings of the 14th Mid-Atlantic Industrial Waste Conference. Lancaster, PA: Technomics; 1982. [42] Shively W, Bishop P, Gress D, Brown T. Leaching tests of heavy metals stabilized with Portland cement. J Water Pollut Control Federation 1986;58(3):234 41. [43] Peters RW. Chelant extraction of heavy metals from contaminated soils. J Hazard Mater 1999;66(1 2):151 210. [44] Reed SC, Crites RW, Middlebrooks EJ. Natural systems for waste management and treatment. 2nd ed. New York: McGraw-Hill; 1995. [45] USEPA. Engineering bulletin: soil washing treatment. Tech. Rep. EPA/540/2-90/017. Washington, DC: Office of Emergency and Remedial Response, United States Environmental Protection Agency; 1990. [46] Wood AL, Bouchard DC, Brusseau ML, Rao PSC. Cosolvent effects on sorption and mobility of organic contaminants in soils. Chemosphere 1990;21(4 5):575 87. [47] Chu W, Chan KH. The mechanism of the surfactant-aided soil washing system for hydrophobic and partial hydrophobic organics. Sci Total Environ 2003;307 (1 3):83 92. [48] Gao Y, He J, Ling W, Hu H, Liu F. Effects of organic acids on copper and cadmium desorption from contaminated soils. Environ Int 2003;29(5):613 18. [49] Maturi K, Reddy KR. Extractants for the removal of mixed contaminants from soils. Soil Sediment Contamination 2008;17(6):586 608. [50] Zhang H, Dang Z, Zheng LC, Yi XY. Remediation of soil co-contaminated with pyrene and cadmium by growing maize (Zea mays L.). Int J Environ Sci Technol 2009;6(2):249 58. [51] Yu J, Klarup D. Extraction kinetics of copper, zinc, iron, and manganese from contaminated sediment using disodium ethylenediaminetetraacetate. Water, Air, Soil Pollut 1994;75:205 25. [52] Naidu R, Harter RD. Effect of different organic ligands on cadmium sorption by and extractability from soils. Soil Sci Soc Am J 1998;62(3):644 50. [53] Labanowski J, Monna F, Bermond A, et al. Kinetic extractions to assess mobilization of Zn, Pb, Cu, and Cd in a metal-contaminated soil: EDTA vs. citrate. Environ Pollut 2008;152(3):693 701. [54] Ke X, Li PJ, Zhou QX, Zhang Y, Sun TH. Removal of heavy metals from a contaminated soil using tartaric acid. J Environ Sci 2006;18(4):727 33. [55] Tejowulan RS, Hendershot WH. Removal of trace metals from contaminated soils using EDTA incorporating resin trapping techniques. Environ Pollut 1998;103:135 42. [56] Sun B, Zhao FJ, Lombi E, McGrath SP. Leaching of heavy metals from contaminated soils using EDTA. Environ Pollut 2001;113(2):111 20.

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5

Chapter Outline 5.1 Atmosphere as a primary sink of air pollutants ..................................................170 5.1.1 The troposphere .............................................................................170 5.1.2 The stratosphere.............................................................................170 5.1.3 Mesosphere ...................................................................................172 5.1.4 The thermosphere...........................................................................172 5.2 Air pollutants ...................................................................................................172 5.2.1 Types of air pollutants.....................................................................172 5.2.2 Suspended particulate matter..........................................................172 5.2.3 Gaseous pollutants .........................................................................173 5.2.4 Secondary pollutants ......................................................................177 5.2.5 Odors ............................................................................................177 5.3 Clean air implementation..................................................................................180 5.3.1 Particulate matter...........................................................................181 5.4 Regulation of air pollution ................................................................................183 5.4.1 European Union .............................................................................183 5.4.2 Australia........................................................................................185 5.4.3 Brazil ............................................................................................185 5.4.4 Canada ..........................................................................................186 5.4.5 China ............................................................................................187 5.4.6 India .............................................................................................188 5.4.7 France...........................................................................................189 5.4.8 United States.................................................................................189 5.4.9 Israel.............................................................................................190 5.4.10 Japan ..........................................................................................190 5.4.11 South Africa.................................................................................191 5.4.12 Switzerland..................................................................................191 5.4.13 The United Kingdom.....................................................................192 5.5 Air pollution control measures ..........................................................................192 5.5.1 Control of particulates.....................................................................192 5.5.2 Biological treatment of air pollution .................................................195 References .............................................................................................................198

Environmental Technology and Sustainability. DOI: https://doi.org/10.1016/B978-0-12-819103-3.00005-6 © 2020 Elsevier Inc. All rights reserved.

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5.1 Atmosphere as a primary sink of air pollutants As reported by the Blacksmith Institute, in 2008 two major pollution incidents were taken place, mainly due to negligence in urban quality management [1]. The Blacksmith Institute, formerly known as Pure Earth (New York), is an international nongovernmental organization (NGO) that works to identify, clean up, and solve pollution problems in low- and middle-income countries where high concentrations of toxic pollutants have been devastating human health, especially in children. As reported by an international agency, outdoor air pollution alone causes 2.1 4.21 million premature deaths annually [2 5]. So, it is necessary to understand air pollution and how various air pollutants impact the structure and function of the atmosphere. Besides this, in order to save the planet from polluted air, it is necessary to know what would be efficient precautionary measures for the remediation of air pollution. Before getting into detail about the paradigm of air pollution, it is necessary to understand the structure and function of the atmosphere covering the vast surface of the Earth. The surface of the Earth is blanketed with atmosphere. The atmosphere has a series of layers that include, from the ground level, (1) the troposphere, (2) stratosphere, (3) mesosphere, (4) thermosphere, and (5) exosphere.

5.1.1 The troposphere The troposphere is the first layer just above the Earth’s surface and contains half of all the Earth’s atmosphere. The most prevalent gases above the surface include nitrogen (78%) and oxygen (21%) with the remaining 1% consisting of argon, and traces of hydrogen, ozone, and other constituents (Fig. 5.1). The temperature and water vapor content in the troposphere decrease rapidly with attitude. The troposphere starts at the Earth’s surface and extends 8 14.5 km high (5 9 mi). This part of the atmosphere is the densest. Almost all weather is in this region. Sulfur dioxide and nitrogen oxide are emitted into the atmosphere and transported by wind and air currents. These gases react with water vapor, oxygen, and other chemicals to form sulfuric and nitric acids. These are then mixed with water and other materials before falling to the ground (Fig. 5.2). Acid rain is responsible for severe environmental destruction across the world and occurs most commonly in the north eastern parts of the United States and eastern Europe, and is becoming increasingly high in parts of China and India. It is mainly found in the troposphere (the lowest layer of the atmosphere).

5.1.2 The stratosphere The stratosphere is the immediate layer after the troposphere. The bottom of the stratosphere is around 10 km (6.2 mi or about 33,000 ft.) above the ground at middle latitudes. The top of the stratosphere occurs at an altitude of 50 km (31 mi).

5.1 Atmosphere as a primary sink of air pollutants

FIGURE 5.1 Gaseous composition of the troposphere.

FIGURE 5.2 Diagrammatic presentation of acid rain. Adapted from: https://images.app.goo.gl/QvJCcUuPfMDzfkCE9.

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The ozone layer is mainly found in the lower portion of the stratosphere from approximately 20 30 km (12 19 mi) above Earth’s surface, though the thickness varies seasonally and geographically. Ozone is produced naturally in the stratosphere when highly energetic solar radiation strikes molecules of oxygen and causes the oxygen atoms to split apart in a photolysis process. The average thickness of the ozone layer is about 300 DU or 3 mm thick. According to NASA, the annual ozone hole reached an average area coverage of 8.83 million square miles (22.9 km2) in 2018. The ozone layer (stratospheric ozone) is a layer of highly concentrated ozone molecules at an altitude of about 30 50 km (stratosphere). The main function of the ozone layer is to absorb the sun’s ultraviolet radiation, hence, protecting the Earth from its harmful effects. Jet aircrafts fly in the stratosphere because it is highly stable.

5.1.3 Mesosphere The mesosphere is directly above the stratosphere and below the thermosphere. It extends from about 50 85 km (31 53 mi) above the surface of the planet. Temperature decreases with height throughout the mesosphere.

5.1.4 The thermosphere The thermosphere is the layer directly above the mesosphere and below the exosphere. Within this layer of the atmosphere, ultraviolet radiation causes the photoionization/photodissociation of molecules creating ions in the ionosphere.

5.2 Air pollutants 5.2.1 Types of air pollutants On the basis of the physicochemical nature of air pollutants (Fig. 5.3) they can be broadly grouped into (1) suspended particulate matter (SPM), (2) gaseous pollutants, and (3) odors.

5.2.2 Suspended particulate matter These pollutants are anthropogenic (manmade) or result from natural mishaps. Particulate matter (PM) is microscopic solid or liquid matter suspended in the Earth’s atmosphere. SPM includes diesel exhaust fumes, coal fly ash, mineral dusts (e.g., coal, asbestos, limestone, and cement), metal dust and fumes (e.g., zinc, copper, iron, lead), acid mists (e.g., sulfuric acid), fluorides, paint pigments, pesticide mists, carbon black, and oil smoke. These SPMs are responsible for variety of health problems such as respiratory infection [6 11], asthma [12 14], lung cancer [15 17], and pregnancy disorders [18 20]. PM is primarily a

5.2 Air pollutants

Particulate matter Volatile organic compounds

Groundlevel ozone

Common air pollutants Carbon monoxide

Sulfur dioxide

Nitrogen dioxide

FIGURE 5.3 Types of air pollutants.

problem in the wintertime in the Bay Area, when seasonal wood-burning makes a substantial contribution. Suspended particulate pollutants are also responsible for damaging plant life. Particulate pollutants result from human activity from a variety of stationary and mobile sources or are formed in the atmosphere by the transformation of gaseous emissions. Some PM is directly emitted from stationary sources such as construction sites, unpaved roads, or field or smock stack fires. Most particles form in the atmosphere as a result of complex reactions of chemicals such as sulfur dioxide and nitrogen oxides, which are pollutants emitted from power plants, industries, and automobiles. Mobile sources of SPM are derived from a variety of human activities. These types of activities include agricultural operations, industrial processes, combustion of wood and fossil fuels, construction and demolition activities, and entrainment of road dust into the air. Secondary pollutants result from thermal, chemical, or photochemical reactions. Due to the thermal action of sulfur dioxide, sulfur trioxide is formed. Sulfur trioxide can dissolve in water and form sulfuric acid mist (catalyzed by manganese and iron oxides).

5.2.3 Gaseous pollutants Gaseous pollutants include sulfur compounds [e.g., sulfur dioxide (SO2) and sulfur trioxide (SO3)], carbon monoxide, nitrogen compounds [e.g., nitric oxide

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(NO), nitrogen dioxide (NO2), ammonia], organic compounds [e.g., hydrocarbons (polycylic aromatic hydrocarbon (PAHs)), aldehyde], halogen compounds and halogen derivatives (e.g., HF and HCI), hydrogen sulfide and mercaptans (odors). Carbon dioxide is a leading air pollutant. The global emission of CO2, in 2018, was 2.7% higher than the previous year. It is a natural component of the atmosphere, essential for plant life, and given off by the human and animal respiratory systems. The largest source of greenhouse gas emissions is from human activities.

5.2.3.1 China China’s greenhouse gas emissions are almost twice those of the United States. At present, China accounts for about 23% of all global CO2 emissions. According to estimates by the US government it is projected that, barring major reform, China will double its emissions by 2040, due to its heavy reliance on fossil fuels for steel production and electricity.

5.2.3.2 United States The United States has never entered into any binding agreement to curb greenhouse gases, but has cut more CO2 emissions than any other nation nevertheless.

5.2.3.3 India India faces challenges in curbing its greenhouse gases even as its population and economy continue to grow. India is the third largest emitter of carbon dioxide, pushing Russia down to the fourth position. Currently, the CO2 load in the atmosphere is about 410 ppm of the Earth’s atmosphere, compared to the about 289 ppm in preindustrial times [21].

5.2.3.4 Sulfur oxide Sulfur oxides (SOx) are mainly produced by volcanoes and in various industrial processes. Coal and petroleum often contain sulfur compounds, and their combustion generates sulfur dioxide. Further oxidation of sulfur dioxide, usually, in the presence of a catalyst such as NO2 forms H2SO4 and, thus, acid rain (Fig. 5.4). This is one of the causes for concern regarding the environmental impact of the use of these fuels as power sources.

5.2.3.5 Nitrogen oxides Particularly, nitrogen oxides (NOx) are emitted from high temperature combustion, and are also produced during thunderstorms by electric discharges, and some are produced by plants, soil, and water. This reddish-brown toxic gas has a characteristic sharp, biting odor. Nitrogen dioxide is an important air pollutant because it contributes to the formation of photochemical smog, which adversely affects human health. The major source of nitrogen dioxide is the burning of fossil fuels, coal, oil, and gas. In urban localities, this gas is produced from motor vehicle exhausts. Other

5.2 Air pollutants

FIGURE 5.4 Formation of acid rain.

sources of nitrogen dioxide are petrol and metal refining, electricity generation from coal-fired power stations, manufacturing industries, and food processing.

5.2.3.6 Carbon monoxide The sources of carbon monoxide (CO) include the combustion of fuel such as natural gas or coal or from the burning of wood. It creates a smog-type formation in the air that has been linked to many lung dieses and has harmful effects on plants and animals. Burning 1 gallon of gas will emit over 20 lbs of carbon monoxide into air [22].

5.2.3.7 Volatile organic compounds Volatile organic compounds (VOCs) are carbon-containing gases and vapors such as gasoline fumes and solvents (excluding carbon dioxide, carbon monoxide, methane, and chlorofluorocarbons). In general, they are categorized as either methane (CH4) or nonmethane VOCs (NMVOCs). Methane is an extremely harmful greenhouse gas which is responsible for enhancing gaseous pollution by helping ozone layer formation and prolong the life of methane in the atmosphere. The aromatic NMVOCs benzene, toluene, and xylene, are suspected carcinogens and may lead to leukemia with prolonged exposure. 1,3-butadiene is another dangerous compound often associated with industrial use.

5.2.3.8 Fluoride Commonly, fluorides are present in the air in the form of hydrogen fluoride (HF), SiF6, and F2. Fluorides in the form of particulates include Ca3AlF6 (cryolite), CaF2, AlF6, CaSiF, NaF, and Na2SiF6. Aerosols are often formed from NaF, NaAIF6. Hydogen fluoride (HF) is the most harmful air pollutant. Brickworks, aluminum factories, glassworks, steelworks, ceramic factories, phosphate fertilizer plants, and uranium smelters are the main sources of fluoride pollutants [23].

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There are mainly two forms of fluorides, namely gaseous form such as hydrogen fluoride and silicon tetrafluoride and the form of solid particles present in the air. Gaseous fluorides are absorbed by plants that are present near to industries, and solid fluoride particles fall to the ground. Mainly, cattle, sheep, horses, and pigs are affected by solid fluoride particles [24 28]. Fluoride mainly effects the structure and function of the bones [29,30] of animals. It also induces tooth destruction in grazing animals, lameness, and stiffening of the bone joints [31].

5.2.3.9 Chlorine The concentration of chlorine in the atmosphere changes on the basis of climatic condition. Even light rain fall can minimize the chlorine concentration in the atmosphere. Large quantities of chlorine are released from evaporated ocean spray as sea salt (sodium chloride) particles. But this chlorine does not reach the stratosphere because it is quickly taken up by clouds, snow, or rain droplets, and, thus, reaches the Earth’s surface. Volcanoes emit large quantities of hydrogen chloride, but this gas is rapidly converted into hydrochloric acid, which dissolves in rain water, ice, and snow and does not reach the stratosphere. In contrast, halohydrocarbons such as chlorofluorocarbons and carbon tetrachloride do not dissolve in water, do not react with snow or other natural surfaces, and are not broken down chemically in the lower atmosphere.

5.2.3.10 Hydrogen chloride The combustion of polyvinyl chloride (PVC) and other hydrocarbon materials emits hydrogen chloride (HCl) gas into the atmosphere. This gas is extremely hydrophobic and changes quickly to hydrochloric acid by reacting with atmospheric moisture and forming aerosol droplets. The burning of coal (particularly from coal-fired power stations) and the incineration of wastes emit hydrogen chloride gas. Coal and food wastes contain common salt (sodium chloride). When these are burned, sodium chloride reacts with hydrogen to give hydrogen chloride. Volcanoes also emit HCl gas during eruption. HCl gas is highly corrosive and causes damage to metallic structures, especially buildings (mostly at sea shores) and monuments.

5.2.3.11 Ammonia Ammonia (NH3) is a highly reactive and soluble alkaline gas. The largest source of NH3 emission is agricultural activity including animal husbandry and NH3based fertilizer application. Decaying organic matter also emits ammonia gas. Ammonia is also generated from the break down and vitalization of urea. Other agriculture-related emissions of ammonia include biomass burning. Ammonia is also generated from a range of nonagricultural sources such as catalytic converters in petrol cars, landfill sites, sewage works, composting of organic materials, combustion, industry, and wild mammals and birds [32,33]. Excess nitrogen brings eutrophication and acidification changes and other deleterious effects [34 40].

5.2 Air pollutants

5.2.4 Secondary pollutants Secondary pollutants may be formed by thermal, chemical, or photochemical reactions. The best example of a secondary air pollutant is ozone. It is formed when hydrocarbons (HC) and nitrogen oxide (NOx) combine in the presence of sunlight, forming NO2 and acid rain, which is formed when dioxide sulfur or nitrogen oxides react with water (Fig. 5.5). Mostly, aquatic environments such as streams, lakes, and marshes are affected by acid rain. The main target in aquatic environments is fish. As it flows through the soil, acidic rain water can leach aluminum from soil clay particles and then flow into streams and lakes. The release of aluminum into aquatic bodies depends on the intensity of the acid rain of a particular locality. The survival of aquatic life depends on the fluctuation of pH caused due to acid rain (Fig. 5.6). Nature has its own way of protecting Earth’s land from acid rain. Many forests, streams, and lakes do not suffer from acid rain because the soil of those areas can buffer the acid rain by neutralizing the acidity in the rain water flowing through it. Photochemical reactions between nitrogen oxide and reactive hydrocarbons can produce ozone (O3). Formaldehyde and peroxyacetyl nitrate (PAN) react together in presence of HCl and formaldehyde, and for bis-chloromethyl ether.

5.2.5 Odors Unpleasant odors are potentially harmful air pollutants and may indirectly affect mental attitude and be a barrier for getting pleasure from nature. Some odors are known to be caused by specific chemical agents such as hydrogen sulfide (H2S),

FIGURE 5.5 Simplified diagram of the ecological effects by nitrogen, sulphur and other greenhouse gas; PM, particulate matter; VOC, volatile organic compound.

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FIGURE 5.6 Critical pH level for animal survival.

carbon disulfide (CS2), and mercaptans (R-SH or R1-S-R2), while others are difficult to define chemically. Odors originate from a variety of sources, but the typical kinds of odors are mainly from industrial sources, sewage treatment facilities, abattoirs, animal renderers, landfills, and composting facilities. Common air pollutants and their sources are presented in Table 5.1.

5.2 Air pollutants

Table 5.1 Examples of the main pollutants associated with some industrial air pollution sources [41]. Category

Source

Emitted pollutants

Agriculture Mining and quarrying

Open burning Coal mining Crude petroleum and natural gas production Nonferrous ore mining Stone quarrying Food, beverages, and tobacco Textile and leather industries Wood products Paper products, printing

SPM, CO, VOC SPM, SO2, NOx, VOC SO2

Manufacturing

Manufacture of chemicals

Phthalic anhydride Chlor-alkali Hydrochloric acid Hydrofluoric acid Sulfuric acid Nitric acid Phosphoric acid Lead oxide and pigments Ammonia Sodium carbonate Calcium carbide Adipic acid Alkyl lead Maleic anhydride and terephthalic acid Fertilizer and pesticide production Ammonium nitrate Ammonium sulfate Synthetic resins, plastic materials, and fibers Paints, varnishes, and lacquers Soap Carbon black and printing ink Trinitrotoluene

Petroleum refineries

Miscellaneous products of petroleum and coal

SPM, Pb SPM SPM, CO, VOC, H2S SPM, VOC SPM, VOC SPM, SO2, CO, VOC, H2S, R-SH SPM, SO2, CO, VOC Cl2 HCl HF, SiF4 SO2, SO3 NOx SPM, F2 SPM, Pb SPM, SO2, NOx, CO, VOC, NH3 SPM, NH3 SPM SPM, NOx, CO, VOC Pb CO, VOC SPM, NH3 SPM, NH3, HNO3 VOC SPM, VOC, H2S, CS2 SPM, VOC SPM SPM, SO2, NOx, CO, VOC, H2S SPM, SO2, NOx, SO3, HNO3 SPM, SO2, NOx, CO, VOC (Continued)

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Table 5.1 Examples of the main pollutants associated with some industrial air pollution sources [41]. Continued Category

Source

Nonmetallic mineral products Glass products manufacture Structural clay products

Basic metal industries

Cement, lime, and plaster Iron and steel

Power generation

Nonferrous industries Electricity, gas, and steam

Wholesale and retail trade Transport

Fuel storage, filling operations

Community services

Municipal incinerators

Emitted pollutants SPM, SO2, NOx, CO, VOC, F SPM, SO2, NOx, CO, VOC, F2 SPM, SO2, NOx, CO SPM, SO2, NOx, CO, VOC, Pb SPM, SO2, F, Pb SPM, SO2, NOx, CO, VOC, SO3, Pb VOC SPM, SO2, NOx, CO, VOC, Pb SPM, SO2, NOx, CO, VOC, Pb

5.3 Clean air implementation In 2005, the World Health Organization (WHO) recommended limits for healthharmful concentrations of key air pollutants both outdoors and inside buildings and homes. It covers annual and daily concentrations of fine particulates, nitrogen dioxide, carbon monoxide, and ozone. In 2009, the WHO incorporated the limitations of gaseous pollutants from indoor mold and dampness, and in 2010, it incorporated emission norms for gases and chemicals from cooking and heating stoves as well as recommendations regarding clean fuel use. In 2014, the WHO issued the first-ever health-based guidelines on clean fuels and technologies for house cooking, heating, and lighting. The guidelines also incorporated limitations for unprocessed coal as a household fuel, instead of using kerosene as a household fuel. Like water and soil pollution, air pollution is also a major concern and risk to habitable life, especially to human beings. Reducing diseases like stroke, heart disease, lung cancer, and both chronic and acute respiratory diseases including asthma may be helpful in reducing the burden of disease on Earth. In 2005, the WHO prescribed guidelines for assessing human health on the basis of air quality. Until 2016, about 91% of the world’s population were deprived of the minimum facility of health care as prescribed by the WHO. In 2016, about 4.2 million premature deaths occurred due to outdoor air pollution. As reported by the WHO, about 91% of premature deaths occurred in low- and middle-income countries. The greatest number was in the South-East and Western Pacific region. Outdoor air pollution affects all people, irrespective of whether they are from low-, middle-, or high-income countries. Casualties due to air pollution are mainly

5.3 Clean air implementation

due to PM with diameters of 2.5 µm or less (PM2.5), which are responsible for cardiovascular and respiratory diseases and cancer. As reported in 2016, by the WHO, about 58% of deaths were due to outdoor air pollution mainly caused by ischemic heart disease and strokes, 16% of deaths were due to chronic obstructive pulmonary disease and acute lower respiratory infections respectively, and 6% of deaths were due to lung cancer. Some noncommunicable diseases like lung cancer may result from the combined effects of smoking and ambient air pollution. In 2013, a survey report by the WHO’s International Agency for Research on Cancer (IARC) says that the presence of PM is one of the main causes of lung cancer. Ambient air pollution is supposed to be a key protecting incident to have control over the intensity of noncommunicable disease both in urbanized and peripheral parts of developed and developing countries. The modernization of science and technology, and the regulation of manufacturing processes have improved the intensity of ambient air pollutants in transport sectors, urban planning, power generation, and industrial sectors. Improvements in industrial manufacturing processes as per cGMP norms has reduced the emission of solid and liquid suspended particles in ambient air polluted localities. Improved management of urban and agricultural wastes includes the capture of methane gas emitted from waste sites as an alternative to incineration (for use as biogas). The use of firewood causes, especially in rural areas, ambient air pollution. This can be avoided by the use of biogas (methane) from agricultural wastes [6]. Controlling logistics systems with green supply chain management [7]; proper urbanization planning with nonconventional energy efficient building development; using low-emission fuels and renewable combustionfree power sources (like solar, wind, or hydropower); the cogeneration of heat and power and distributed energy generation (e.g., minigrids and rooftop solar power generation) [8]; and strategies for waste reduction, waste separation, recycling and reuse, or waste reprocessing [9] are important strategies to reduce ambient air pollution both in urbanized and rural areas. Indoor smoke from household air pollution is equally as bad as that caused due to ambient pollution. About 3 billion people who cook and heat their homes with fuel and coal are at risk. Some 3.8 million casualties were caused due to household air pollution in 2016. The 2005, WHO guidelines prescribed limitations for atmospheric and ambient air pollution causing health risks. It was suggested by the WHO that a reduction in particulate size from 70 to 20 µm/m3 can minimize air pollution related deaths to 15%. Currently, the WHO is in the process of updating the guidelines, and these are expected to be finalized by 2020.

5.3.1 Particulate matter PM is an important indicator for air quality assessment. As it is directly linked to the inhalation of polluted air. The health risk is more intensified due to air pollutants as compared to other pollutants. As previously mentioned, the major

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components of air pollutants are sulfate, nitrates, ammonia, sodium chloride, black carbon, and mineral dusts. Solid and liquid suspended particles of organic and inorganic substances of about 2.5 10 µm or less in size can penetrate and lodge deep inside the lungs. Chronic exposure to particles contributes to the risk of developing cardiovascular and respiratory diseases as well as lung cancer. Small particulate pollution has health impacts even at very low concentrations. The WHO guidelines are aimed at achieving the lowest concentrations of PM by 2025. Exposure to other gaseous pollutants like ozone (O3), nitrogen dioxide (NO2), and sulfur dioxide (SO2) can cause serious health risks. Asthma, bronchial symptoms, lung inflammation, and reduction in the efficiency of the functioning of the lungs are caused by these gaseous pollutants.

5.3.1.1 Ozone The natural amount of ozone in ambient air pollution is about 0.04 ppm, which is not harmful to human health. Vegetation can also emit organic chemicals that help to form ozone. The WHO also made the differences between ozone at ground level and ozone in the upper atmosphere clear, which is one of the major constituents of photochemical smog.

5.3.1.2 Nitrogen dioxide The limitation of nitrogen dioxide is 40 µg/m3 annual mean and 200 µg/m3 1 hour mean. The value of 40 µg/m3 (annual mean) was set to protect the public from the health effects of gaseous NO2.

5.3.1.3 Sulfur dioxide Sulfur dioxide levels should not exceed 500 µg/m3 over average periods of 10 minutes. Respiratory symptoms appear after a period of exposure to SO2 as short as 10 minutes. The WHO is the custodial agency for three air pollution related indicators of the Sustainable Development Goals, which include mortality from air pollution, access to clean fuel and technologies, and air quality in cities. The WHO developed the Health Economic Assessment Tool (HEAT), the Sustainable Transport Health Assessment Tool (STHAT), and the Integrated Transport and Health Impact Modelling Tool (ITHIM) for overall air pollutants limitation in ambient air and indicators for quick assessment. The WHO is developing a clean Household Energy Solutions Toolkit (CHEST) to provide countries and programs with the tools needed to create policies that expand on clean household energy access and use. This is important as pollutants released in and around households (household air pollution) contribute significantly to ambient pollution. CHEST involves assessment, guidance on standards and testing for household energy devices, monitoring and evaluation, and materials to empower the health sector to tackle household air pollution.

5.4 Regulation of air pollution

The WHO also helps member states in monitoring and implementing methods of exposure assessment of ambient air pollution on the risks to health. Besides this, the WHO assists joint task forces on the health aspects of air pollution and provides supporting documents. In order to increase the efficacy in working out the program on Transport Health and Environment (PEP) the WHO has been helping regional model under the sponsorship of Pan European Program on Transport Health and Environment (PEP).

5.4 Regulation of air pollution The past decade has witnessed the overall development of diverse jurisdiction’s regulation of both stationary and mobile sources of air pollution caused by oxides of nitrogen, sulfur, and carbon as well as ozone and other hazardous pollutants like PM and suspended particles. Besides this, the regulation of the use of fuel quality, renewable fuel requirement, and vehicle emission standards are also covered. On the basis of the nature of the pollution, geographical location, and political scenario, the regulation aspects on air pollution vary from country to country. Examples of the jurisdictions of different countries including supranational entities (the European Union) are countries having common law legal systems (Australia, Canada, India, and the United Kingdom), some civil law countries (Brazil, China, France, Israel, Japan, and Switzerland), some countries have federal systems of law (the United States, India, Brazil, Germany, and Mexico), and countries with mixed legal systems (South Africa). Some of countries are unitary in nature, while others have federated governments.

5.4.1 European Union The overall aim of the European Union is to conserve natural resources and to develop their functional efficacy, to maintain natural greenery, create a competitive low-carbon economy, and safeguard EU citizens from environment-related risks to health and wellbeing by 2020. In order to succeed, the European Union has framed a wide range of legislative measures to fight air pollution and improve air quality. International commitments were incorporated into EU legislation. The legislation prescribed lower limitations of ambient air quality, vehicle emission standards to reduce greenhouse gas emissions, fuel quality standards, establishes an emission trading scheme, limits industrial pollution, and is applicable to all members states. "Europe air pollution act" to control industrial gaseous pollutants emission is a part of pollution regulatory acts for discharge of wastewater and generation of waste.This is with reference to European Parliament and Council on Industrial emission implemented with effect from 2010/75/EU (the Industrial Emission Directive or IED). It is mainly to control emission of ambient air pollutants from

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industrial operational process in improper way. The IED was adopted on November 21, 2010. It is based on a commission proposal recasting seven previously existing directives (including, in particular, the IPPC Directive). The technology entertainment design (TED) entered into force on January 6, 2011, and had to be transposed by member states by January 7, 2013. The IED aims to minimize industrial emissions across the European Union. The IED functions on the basis of several pillars which include (1) an integrated approach, (2) availing the best available techniques and methods, (3) flexibility, (4) inspections, and (5) public participation. 1. Integrated approach This is mainly based on the overall performance an industry and its output of pollutants in the form of air pollutants, effluents containing solid and liquid wastes, the selection and screening of raw materials to be used for manufacturing processes, energy efficiency of unit operation systems, and the involvement of international regulatory norms like good manufacture practice (GMP), current good manufacture practice (cGMP) in industrial operation systems. 2. Availing the best available technologies The ambient air pollutants emission limit should be within the limit of advanced technologies available in a state. The implementation of this program is in association with member states, experts from industry, and environmental organizations. The overall action plan is coordinated by the European IPPC Bureau at the EU Joint Research Centre in Seville (Spain). The data resulted in exercising BAT can be used while implementing action plan by the European IPPC (Integrated pollution prevention and Control) Bureau. Ultimately, the IED requires that these BAT conclusions are the reference for setting permit conditions. 3. Flexibility In order to have better understanding between regulatory operations and implementation bodies and industries, flexibility in the lower limitation value for ambient air pollutants can be set in specific cases. The competent authority shall always document its justification for granting such derogations. 4. Environmental inspection Environmental inspection is a mandatory requirement for the IED. Member states shall set up a system of environmental inspections and draw up inspection plans accordingly. The IED requires a sit in visit to take place at least every 1 3 years using risk-based criteria. 5. Right to participate The public has the right to exercise their power to participate in the decisionmaking process in the implementation of environmental regulation for ambient air quality analyses. Besides this, through the European Pollutant Release and Transfer Register (E-PRTR) emission data reported by member states are made accessible on major industrial activities.

5.4 Regulation of air pollution

As prescribed in the IED (Articles 309 and 73), the commission has to review emissions from certain types of animal rearing and combustion plants. In addition, on the basis of IED Article 73 the information obtained by the Member States has to be brought into the notice of the industries for taking precautionary majors on how to reduce ambient air contamination. IED Article 73 requires the commission to report on the implementation of the directive on the basis of information reported by member states.

5.4.2 Australia The Australian federal government in collaboration with state and territory governments has framed air quality emission standards through the National Environment Protection Measures. The National Clean Air Agreement, signed in 2015, provides the basis for a joint work program related to reducing air pollution and improving air quality. The federal government has also framed national fuel quality standards and vehicle emission standards for new and newly imported vehicles; emission standards for in service vehicles are the responsibility of state and territory governments. In Australia currently, Australian’s air pollution regulatory act is not standard enough to have control over ambient air pollution. More than 3000 Australians die from exposure to air pollution each year. Thousands of people are affected by stroke, heart disease, and asthma. In Australia, national air pollution limits currently exceed the WHO norms for ambient air quality standards significantly. Whereas much stricter standards have been adopted in most other countries including the United States, the European Union, and China. In Australia, coal-fired power stations are a major contributor to air pollution, mainly nitrogen oxide (NOx) and sulfur dioxide (SO2). The dumping of coal ash into natural aquatic systems causes heavy pollution. Pond water is contaminated by coalfired power stations with waste byproducts leaching into local land and waterways. Australia’s emission standards are based on European regulations for light-duty and heavy-duty vehicles with the acceptance of selected US and Japanese standards. The current policy is to fully harmonize Australian regulations with UN and Economic Commission for Europe (ECE) standards. The Euro 5 emission standards for light vehicles were introduced in November, 2013. The National Transport Commission (NTC) and Australian Design Rules (ADR) jointly developed emission standards for highway vehicles and engines. Under such a regulation, all new vehicles manufactured or sold in the country must comply with the standards, which are tested by running the vehicle or engine in a standardized test cycle.

5.4.3 Brazil In 1999, the law that governs the environmental policy was amended to establish a new environmental policy and a national system of the environment. So, the National Council of Environment (CONAMA), which was established in 1981,

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updated its environmental policy to have better control over pollution in order to lower health risks, especially from ambient air contamination. Prior to this, there were pollution emission guidelines that allowed industries to pollute to a certain extent without being liable for any environmental damage. However, after this policy was passed, strict liability was applied, which determined that industries were accountable for all the pollution they were causing. In addition, authorized public prosecutors are allowed to act in defense of the any environmental issues. Later, NGOs were given the right to do the same as public prosecutors for environment protection. The Brazil Ministry of the Environment employ agents for coordinating, supervising, and controlling the Brazil Environmental Policy. The federal government has developed the National Environment System (SISNAMA) in association with local state government agencies, the CONAMA, and Brazil Institute of Environment and Renewable Natural Resources (IBAMA) in order to facilitate environmental licensing before any potentially damaging and polluting activities take place in any part of Brazil’s territory. CONAMA is also in charge of regulating atmospheric emission limits for air pollutants. In this capacity, CONAMA has issued several resolutions including, among other things, the Program for Control of Air Pollution by Automotive Vehicles, the National Air Pollution Control Program, the Program for the Control of Air pollution by Motorcycles and Similar Vehicles, Vehicle pollution Control Plans, and Maintenance Programs for Vehicles in use. The CONAMA has been given the privilege to represent industry, municipal government, and civil society to participate in decision making toward limiting ambient air pollution. Besides this, Brazil has encouraged industrialists to produce ethanol and biodiesel to minimize the use of fossil fuels. Brazil could be able to introduce about 45% of energy and 18% of fuels from renewable sources. The Ministry of Environment is responsible for Brazil’s national environmental policy. The Ministry of Environment has specific departments to deal with climatic change and environmental quality, regulation of industrial emission into the atmosphere, biodiversity and forests, water resources, sustainable urban and rural development, and environmental citizenship. Other authorities include the National Council on the Environment, the National Council of Amazon, the National Council of Water Resources, and the Chico Mendes Institute for Biodiversity Conservation (ICMBIO). Brazil Institute of Environment, Renewable Natural Resources (IBAMA), and the Board of Management of Public Forests are also involved in regulating environmental pollution, directly or in directly.

5.4.4 Canada Federal Parliament and the provincial legislative authority jointly look after the environmental protection and conservation. In 1999, Canada’s main federal legislation framed regulation acts for environmental protection. The Canada federal government has issued regulations to control emissions of criteria air contaminants (CAC) (nitrogen oxide, sulfur dioxide, carbon monoxide, PM, etc.) as well

5.4 Regulation of air pollution

as greenhouse gases. Generally, the Canadian approach has been to harmonize emission standards with the United States Environmental Protection Agency’s federal standards. On October 5, 2016, Canada was also a member of the signatories of the Paris Agreement. Canada’s Nationally Determined Contribution (NDC) is to reduce greenhouse gas emissions by 30% by 2030. The Canadian Environmental Protection Act, 1999 (CEPA), target is to prevent pollution and protect the environment. At the federal level, Environment and Climate Change Canada (ECCC) and Transport Canada (TC) have the mandate to regulate emissions from internal combustion engines. Under CEPA, ECCC has the “authority to regulate emission from on-road engines, as well as from most categories of off-road engines.” The CEPA “transfers the legislative authority for regulating emissions from on-road vehicles and engines to Environment Canada from Transport Canada’s Motor Vehicle Safety Act.” TC has been authorized to regulate emissions from aircrafts, railway locomotives, and commercial marine vessels. The National Pollutant Release Inventory (NPRI) keeps track of the overall status of pollution in Canada. As per the NPRI, the general citizens of Canada have access to the inventory of pollutant release to air, water, and land. In addition, Canadians also have access to tools and techniques for the disposal and transfer of wastes for recycling processes. The NPRI publish reports for ECCC related to industrial facilities (meeting certain criteria) under the authority of CEPA, 1999. Besides this, the NPRI provide information on pollutant emissions from various nonindustrial sources, which are helpful in identifying and monitoring sources of pollution in Canada, and for developing indicators for the quality of air, water, and land.

5.4.5 China Since 1979, under the Law on Prevention and Control of Air Pollution, China has passed many laws, regulations, and standards addressing environment protection including air pollution prevention and control. In this connection, the industries have to take prior permission to keep limitation on emission of air pollutants into ambient atmosphere. Entities must obtain a pollution discharge permit for industrial emissions or the emission of specific hazardous and toxic atmospheric pollutants. From January 1, 2018, a newly designed environmental protection tax replaced the pollution discharge fee. The tax applies to specific air pollutants, not including carbon dioxide. China has been implementing vehicle emission standards that mainly follow EU standards. The China standard for light-duty vehicles is similar to the Euro 5 standard with some deviation. China has also fixed national standards for fuel consumption limits for various type of vehicles. As per this act Phase IV standards passenger car model developed in January 1, 2016 should have average mileage 5.0/L/100 km, manufactured after 2020. China has created a New Energy Vehicle (NEV) credit system under which passenger car manufacturers will be required to earn NEV credits starting in 2019. Excess NEV credits, if any, may be used to offset automakers’ negative

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FIGURE 5.7 Annual sales of new energy vehicles in China between January 2011 and December 2018.

corporate average fuel consumption (CAFC) points that occur by exceeding the CAFC target set by the state. The new energy vehicles in China is the world’s largest selling vehicle with cumulative sales of almost 3 million units through 2018 (Fig. 5.7). The Chinese government uses the term NEVs to designate plug-in electric vehicles eligible for public subsidies, and including only battery electric vehicles, plug-in hybrid electric vehicles, and fuel cell electric vehicles.

5.4.6 India India was one of the signatories in the Stockholm Declaration (UN Conference on the Human Environment), held in June, 1972. The main target of the Stockholm

5.4 Regulation of air pollution

Declaration was the preservation of the environment and the prevention and control of pollution. Under Article 253, the constitution of India passed the Air (Prevention and Control of Pollution) Act in 1981 for the prevention, control, and abatement of air pollution. The Air Act was passed in the same pattern as the Water Act, 1974. As stated in Air Act, air pollution means the presence of any “air pollutant” in the atmosphere that is injurious to health. The Air Act confers regulatory power to the Central Pollution Control Board (CPCB) and the State Pollution Control Board (SPCB) to prevent and control air pollution. The CPCB and SPCB have been empowered to improve the quality of air and to prevent, control, or abate air pollution. Section 16 and Section 17 explain the operation and implementation of air pollution acts to control and limit air pollutants in the atmosphere. The CPCB is under the direct control of the central government, and the SPCB is under the CPCB and the state government.

5.4.7 France The French air quality regulation is based on a mixture of international agreements, European Directives, and domestic legislation. In 1961, the French government introduced the first domestic legislation on air pollution. Since 1996, French law has recognized the people’s right to breathe clean air that is not harmful to health. Various regulatory measures are adopted at the national and local levels to maintain ambient air quality. The Central Laboratory for Air Quality Monitoring in association with license-holding local nonprofit organizations monitor air quality. This air quality monitoring system informs the implementation of air quality improvement measures. Emissions of certain substances are prohibited on the basis of manufacturing technical standards (like failure to follow GMP or cGMP), sale, storage, maintenance, and/or disposal of outdated products. In 2015, the government authorized the local authorities to establish traffic zones in urban areas and other localities on the basis of atmosphere protection. French air quality control also relies on national objectives on the emission of several air pollutants including a national carbon budget on a priority basis. The National Low-Carbon Strategy (for the national carbon budget) and National Atmospheric Pollutant Emissions Reduction Plan have joint strategies for long-term plans to have control over atmospheric sulfur dioxide, nitrogen oxide, NMVOCs, ammonia, and fine particles.

5.4.8 United States In 1963, the United States federal law was designed to control air pollution on a national level. It is the most compressive and influential environmental law in the world. It is mainly governed by the US Environmental Protection Agency (US EPA) in association with state, local, and tribal government. The 1955 Air pollution Control Act was the first US federal legislation that pertained to air

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pollution and funding federal government research on air pollution. The 1963 act accomplished this by establishing a federal program within the US Public Health Service and authorizing research into techniques for monitoring and controlling air pollution. In 1965, certain amendments were introduced by the Motor Vehicle Air Pollution Act, which authorized the federal government to set required standards for controlling the emission of pollutants from certain automobiles, beginning with the 1968 model. Again, in 1967, a second amendment was incorporated into the Air Quality Act. Targeting the federal government to increase its activities on the control over interstate ambient air pollution due to transport systems, and air pollutants emitted from stationary sources. Besides this, the 1967 amendments also authorized expanded studies of air pollutant emission inventories, ambient monitoring techniques, and control techniques. In due course, by the end of 1970, all the states of the United States had adopted air pollution controlling programs. Further amendments were incorporated, keeping in view acid rain, ozone depletion, toxic air pollution, and greenhouse gases. In addition, the amendments also established new auto gasoline reformulation requirements and set Reid vapor pressure (RVP) standards to control evaporative emissions from gasoline. The RVP is a common measure of the volatility of gasoline and other petroleum products. The test method measures the vapor pressure of gasoline, volatile crude oil, jet fuel, naphtha, and other volatile petroleum products, but it is not applicable for liquefied petroleum gases. In 1990, the Clean Air Act was amended with the provision for citizen suits. In the United States, a citizen suit is a lawsuit by a private citizen to enforce a status. Citizen suits are particularly common in the field of environmental law. The Clean Air Act was the first major environmental law in the United States to include a provision for citizen suits. Subsequently, it was implemented in numerous states, and local governments have enacted similar legislation, implementing federal programs.

5.4.9 Israel Israel is the signatory to a number of environmental protection international agreements including the 2016 Paris Agreement. Israel has an extensive legislative and regulatory provision to have control over atmospheric and ambient air pollutants like ozone, greenhouse gases, and other hazardous chemicals in the form of particulate or suspended particles. A wide range of action plans have been designed on the development of clean air strategies and standards for the production of renewable fuels.

5.4.10 Japan Japan legislation has a well-framed air pollution act to protect ozone layer depletion. The Ozone Layer Protection Act governs the manufacturing process of specific products responsible for emitting gaseous pollutants causing ozone layer depletion. The

5.4 Regulation of air pollution

use, management, and disposal of fluorocarbons are strictly regulated by the Fluorocarbons Management Act, the Home Appliances Recycling Law, and the Automobile Recycling Law. In the Air Pollution Control Act and Road Transport Vehicle Act, the emission standards for automobiles, nitrogen oxide, and PM have been controlled. Under the Air Pollution Act, the Ministry of Environment may prescribe maximum permissible limits for the properties of automobile fuel or maximum permissible limits for the quantity of substances contained in automobile fuel. Under the Act on Rationalizing Energy Use, the Ministry of Economy, Trade, and Industry (METI) and the Ministry of Land, Infrastructure, Transport, and Tourism (MLIT) have established standards for the improved fuel efficiency of automobiles taking into consideration the highest level of fuel efficiency.

5.4.11 South Africa In 2004, South Africa implemented the Air Quality Act to have control over various aspects of pollution including national norms and standards for the regulation of air quality in the country. The Ministry of Environmental Affairs is authorized to enforce the regulatory measures for air pollution control. In 2007, national legislation implemented the National Framework for Air Quality Management. After a gap of two years, in 2009, the Ministry issued national ambient air quality standards for seven pollutants including carbon dioxide and ozone. In 2012, the Minister replaced the 2007 National Framework and issued national ambient quality standards for PM with an aerodynamic diameter of less than 2.5 µm. In 2013, the Minister issued emission standards for a number of listed activities detrimental to the environment. In 2015, the Minister issued regulations for the phasing out of certain ozone-depleting substance. After a gap of two years, in 2017, the Minister declared a number of greenhouse gases including carbon dioxide and methane as pollutants contributing to the greenhouse effect. South Africa does not have vehicle fuel emission regulatory acts, but in place imposes environmental levies on carbon dioxide emissions of new vehicles manufactured in South Africa. It is also applicable to imported vehicles from other countries.

5.4.12 Switzerland While framing the national air pollution act, Switzerland has incorporated several air pollution acts dealing with greenhouse emissions and air pollution, selecting from various international treaties. Switzerland uses various measures to minimize air pollution and greenhouse gas emissions into the ambient atmosphere. In addition, restriction in emitting greenhouse gases responsible for ozone layer depletion is also taken into consideration. Levies incentive taxes on petrol and diesel, extra-light fuel oil, volatile organic compounds, and the production, extraction, and import of thermal fuel; participates in emission trading; set building and vehicle emission standards; requires

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fuel importers and operators of fossil-thermal power plants to compensate for CO2 emission; make voluntary agreements with industry sectors to reduce emission; promotes climate program training and communication; and set up a technology funds to guarantee loans for companies that are developing and marketing new products and methodologies for reducing greenhouse gas emission are major provision provided by the government to reduce the burden of air pollutants load on the ambient atmosphere

5.4.13 The United Kingdom The United Kingdom has a wide range of robust legislations to monitor air pollution. The United Kingdom has incorporated number of legislation of EU Air pollution act to make the air pollution act stronger. The government has entitled local authorities to exercise legislative power to maintain ambient air pollution standards as prescribed in the EU Air Pollution Act. It is also working to reduce the amount of pollutants in car emissions. The United Kingdom is party to the European Union’s Emissions Trading Scheme, which has established a cap on the amount of carbon emission specified installations are permitted to be produced each year, allowing them to either take measures to reduce the amount of emission or purchase allowances through auctions to overproduce the emission.

5.5 Air pollution control measures Air pollution control involves reducing the atmospheric pollutant load by which normal harmony in lifestyle can be maintained without disturbance to neighboring ecosystems. When the ambient air contains more than the permissible limit of air pollutants, as prescribed in a state or country’s legislative act or the norms of the WHO standards, it is known as polluted air. The atmosphere is prone to pollution from natural sources as well as from human activities. As described previously, some natural phenomena such as volcanic eruptions and forest fires may have, not only local and regional effects, but also long-lasting global ones. The best way to protect air quality is to avoid the emission of pollutants rather than using huge budgets for designing mechanical devises to remove air pollutants from exhaust gas at the site of generation. These devices are described here.

5.5.1 Control of particulates A variety of mechanical devises like cyclones, scrubbers, electrostatic precipitators, and baghouse filters are presently being used to clean contaminated air. Particulate, dusts, and suspended solid particles are accumulated in the equipment by forming agglomerates that can be removed from the equipment and disposed of. The use of specific equipment mainly depends on the nature of the pollutant

5.5 Air pollution control measures

in ambient air. The physical characteristics of particles or particulates that influence the agglomerate are corrosivity, reactivity, shape, density, and especially size and size distribution. Other factors include airstream characteristics (e.g., pressure, temperature, and viscosity), flow rate, removal efficiency, and allowable resistance to airflow. 1. Cyclones Particulates from contaminated air can be removed by a cyclonic separation process. This is a process by which, without using any filter system, the particulates from air, gas, or liquid streams can be separated. The system used for the removal of particulates from liquid streams is known as a hydrocyclone. From gas, a gas cyclone is used. Rotational effects and gravity are used to separate mixtures of solids and fluids. These methods can be used to separate fine droplets of liquid from gaseous streams. Several cyclone separators can operate in parallel, and this system is known as a multicyclone. The size of the cyclone can vary drastically depending on the volume of the flue gas to be used for cleaning. The size can range from a relatively small 1.2 1.5 m tall (about 4 5 ft.) to around 9 m (30 ft.) (Fig. 5.8). Cyclone separators work much like a centrifuge, but with a continuous feed of dirty air/flue gas. In a cyclone separator, dirty flue gas is fed into a chamber. The inside of the chamber creates a spiral vortex, similar to a tornado. This spiral formation and the separation is shown in Fig. 5.8. The lighter component of the gas has less inertia, so it is easier for it to be influenced by a vortex and travel up it. Contrarily, larger components of PM have more inertia and are not as easily influenced by the vortex. Since these larger particles have difficulty following the high-speed spiral motion of the gas and the vortex, the particles hit the inside walls of the container and drop down into a collection hopper. These chambers are shaped like an upsidedown cone to promote the collection of these particles at the bottom of the container. The clean flue gas escapes out the top of the chamber. 2. Scrubbers Scrubber air pollution control devices are used to separate PM from contaminant liquid or flue gas. This atomized liquid (typically water) entrains particles and pollutant gases in order to effectively wash them out of the gas flow. Scrubbers have a wide range of functions with the potential to remove solids, mists, and gases simultaneously while also providing cooling. Explosive and flammable gases can also be handled. The main drawback of scrubbers is their corrosion of inner wall with waste slurry streams that are not convenient for recycling and disposal.

5.5.1.1 Wet industrial scrubber Wet industrial scrubbers are widely used in industry. In its most basic form, water is encapsulated in a metal or composite container. Contaminated gas is passed through the water, and the water absorbs the contaminants. Other liquids can be

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Cleaner air

Gas outlet tube Inlet

Dirty air

Cyclone body

Conical section

Dirt

FIGURE 5.8 A diagrammatic profile view of a cyclone separator.

used to effectively remove varied contaminates. These liquids can be anything from highly positively or negatively charged to noncharged. Because pollutants can differ in their charge, scrubbers can be packed with a liquid that will bind most effectively to remove specific contaminates from gas. In wet scrubbers, liquid gas association increases the moisture level of the gas that is being expelled from the scrubber. The increase in the moisture level of the gas will create a visible cloud existing within the scrubber.

5.5.1.2 Dry industrial scrubber In dry industrial scrubbers, neither water nor any other liquid is utilized. A dry industrial scrubber uses sorbent or dry reaction material that absorbs contaminants that are mixed with the polluted gas. Dry scrubbers are used primarily to remove acids found within gases.

5.5 Air pollution control measures

5.5.1.3 Electrostatic precipitators In electrostatic precipitators, charged energy is used to remove dust and other contaminates from flue gas. It is important to match the polarity and type of the charge to bind to and remove the pollutants from the gas. An example of a design of an electrostatic precipitator is a plate precipitator. The plate is a sheet of metal that is charged with a specific type of charge. These plates are designed to run parallel with the piping so that the gas will pass by the plates and the plates will remove dust or contaminates. In addition to metal plate electrostatic precipitators, there are also wet electrostatic precipitators that help to remove high-moisture-content gases. Some of the chemicals that can be removed from gas include sulfuric acid. The resulting slurry that contains the bound pollutants is rotated away from the electrostatic precipitator to remove the contaminates and maintain an effectively charged surface for further pollutant removal.

5.5.2 Biological treatment of air pollution Mostly, aerobic microbes (mainly mesophilic bacteria) are used for biological remediation of contaminated air. Mesophilic bacteria can be fed on both organic and inorganic compounds in waste gas. Microbes metabolically degrade contaminates and form carbon dioxide, water, and salts. This technology is mainly used in Europe. There are two main types of biological treatment technologies: 1. Biofilters Biofilter technology is the simplest and cheapest technique used to treat contaminated gas. It mainly consists of a bed of compost mixed with tree bark, peat, heather, or soil, about 1 m deep, through which contaminated gas is blown. The biofilter bed is mixed with a wide range of mesophilic bacteria having the potential to convert air pollutants into carbon dioxide, water, and salts. This technology is widely used in treating malodorous compounds and water-soluble VOCs. Mostly the food processing industry, animal product processing units, off-gas from wastewater treatment facilities, pharmaceuticals, wood products manufacturing, paint and coatings application and manufacturing, and resin manufacturing and application units use this technique successfully. The main drawback with the biofilter technique is the need of huge amounts land for making the biofilter bed. A large biofilter ( . 200,000 acfm) may occupy as much or more land than a football field. 2. Bioscrubbers A bioscrubber mainly consists of a gas scrubber and a biological reactor. The basic function of a gas scrubber is to remove water-soluble components from contaminated air/flue gas using wash water. In an activated-sludge reactor, pollutants

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that have been absorbed by the wash water are biologically degraded. The purified scrubbing liquid is circulated to the scrubber, where it is able to reabsorb pollutants (Fig. 5.9). Mesophilic bacteria present in the activated-sludge reactor convert hydrocarbon into water and carbon dioxide. Nondegradable hydrocarbons remain in the wash water. Components such as H2S and NH3 are converted into sulfate and nitrate respectively. Regular drainage of salt precipitin residual water from the bioreactor is needed in order to keep the salt content and the levels of nondegradable hydrocarbons down. The monitoring of salt precipitated water is carried out on the basis of conductivity or via fixed discharge. The level of discharge is determined by the flue gas composition. It has been noticed that a conductivity of 5 mS/cm is favorable for stable biological degradation. The hydraulic residence time for wash water was noticed to be 20 40 days [36].

Bioscrubber Opslag waswater

Clean gas

Raw gas

Scrubber

Scrubbing water

Pump Fan

Pump

Polluted scrubbing water

Activated sludge reactor

Sedimentator

Air Sluice

Return of sludge

Recirculation pump

FIGURE 5.9 Activated-sludge bioscrubber.

5.5 Air pollution control measures

A gas scrubber should have the provision of a flue gas/polluted air detention time of about 1 s. Spray nozzles should be free from the problem of the blocking of biosludge. In order to maintain the growth of mesophilic microbes, special nutrients containing nitrogen, phosphorus, and trace elements should be supplied as per need. In addition, the provision of bubbling sufficient clean air/or oxygen should be included in a bioscrubber to support the growth of microorganisms. Advantages and disadvantages Advantages

• A wide range of hydrocarbon-rich pollutants can be used and no VOCs • • •

residues are left Easily degradable and rich in degradable pollutants of which high concentrations can be handled High concentration of acidifying sulfur, nitrogen, and chlorine can be easily handled Compared to biofilters and biotrickling, it is a better option for handling large quantities air pollutants. Disadvantages

• A continuous and stable flue gas stream is required, and any fluctuation in flue gas stream may hamper the process

• Mostly suitable for soluble components • Problem of sludge disposal due to safety concerns • Discharge water needs additional treatment.

5.5.2.1 Trickling-filter scrubbers Biotrickling-filters have the provision of three chambers. The bottom chamber is the carrier of odorous air, which is fed to the middle chamber having an immobilized biological catalyst mainly consisting of autotrophic bacteria in the lower part and heterotrophic bacteria in the upper part of the middle chamber. Odorous air is forced into the middle chamber. The microbial systems present in the middle chamber absorb the pollutants in the water-soluble air and the foul odor present in the flue gas/or contaminated gas. The clean air is fluxed out from the system. As with the activated-sludge scrubber, gaseous contaminants are transferred into the liquid phase with a counter current scrubber. Instead of being fed into an activated sludge pond, however, the pollutant-laden scrubber wastewater is spread over a trickling filter. The technology has the upper hand over the activated sludge treatment process. The main advantage with biofiltration is its low operation costs. In some cases, where gas streams have high or highly variable contaminant concentrations, the biotrickling-filter can be coupled with conventional scrubbing or activated carbon. The activated carbon removes the majority of pollutants and precedes the biofilter to obtain emissions within the capability of the biofilter.

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References [1] Reports. WorstPolluted.org. Archived from the original on August 11, 2010. [2] 7 million premature deaths annually linked to air pollution. WHO; March 25, 2014. [3] Lelieveld J, Klingmu¨ller K, Pozzer A, Burnett RT, Haines A, Ramanathan V. Effects of fossil fuel and total anthropogenic emission removal on public health and climate. Proc Natl Acad Sci US A 2019;116(15):7192 7. [4] Energy and Air Pollution; 2016. Iea.org. https://www.iea.org › newsroom › news › june › energy-and-air-pollution. [5] Study links 6.5 million deaths each year to air pollution. The New York Times; 2016. [6] D’Amato G, Liccardi G, D’Amato M, Holgate S. Environmental risk factors and allergic bronchial asthma. Clin Exp Allergy 2005;35:1113 24. [7] Wang L, Pinkerton KE. Air pollutant effects on fetal and early postnatal development. Birth Defects Res C Embryo Today 2007;81:144 54. [8] Chauhan AJ, Johnston SL. Air pollution and infection in respiratory illness. Br Med Bull 2003;68:95 112. [9] Darrow LA, Klein M, Flanders WD, Mulholland JA, Tolbert PE, Strickland MJ. Air pollution and acute respiratory infections among children 0-4 years of age: an 18year time-series study. Am J Epidemiol 2014;180:968 77. [10] Le TG, Ngo L, Mehta S. Effects of short-term exposure to air pollution on hospital admissions of young children for acute lower respiratory infections in Ho Chi Minh City, Vietnam. Res Rep Health Eff Inst 2012;5 72 discussion 73 83. [11] Jacquemin B, Siroux V, Sanchez M. Ambient air pollution and adult asthma incidence in six European cohorts (ESCAPE). Environ Health Perspect 2015;123:613 21. [12] Diaz-Sanchez D, Tsien A, Fleming J, Saxon A. Combined diesel exhaust particulate and ragweed allergen challenge markedly enhances human in vivo nasal ragweedspecific IgE and skews cytokine production to a T helper cell 2-type pattern. J Immunol 1997;158:2406 13. [13] Muranaka M, Suzuki S, Koizumi K. Adjuvant activity of diesel-exhaust particulates for the production of IgE antibody in mice. J Allergy Clin Immunol 1986;77:616 23. [14] Tunnicliffe WS, Burge PS, Ayres JG. Effect of domestic concentrations of nitrogen dioxide on airway responses to inhaled allergen in asthmatic patients. Lancet 1994;344:1733 6. [15] Mathers CD, Boerma T, Ma Fat D. Global and regional causes of death. Br Med Bull 2009;92:7 32. [16] Yu XJ, Yang MJ, Zhou B. Characterization of somatic mutations in air pollutionrelated lung cancer. EBioMedicine 2015;2:583 90. [17] Cohen AJ, Ross AH, Ostro B. The global burden of disease due to outdoor air pollution. J Toxicol Environ Health A 2005;68:1301 7. [18] Selevan SG, Kimmel CA, Mendola P. Identifying critical windows of exposure for children’s health. Environ Health Perspect 2000;108(Suppl. 3):451 5. [19] Luck W, Nau H, Hansen R, Steldinger R. Extent of nicotine and cotinine transfer to the human fetus, placenta and amniotic fluid of smoking mothers. Dev Pharmacol Ther 1985;8:384 95. [20] Salvi S. Health effects of ambient air pollution in children. Paediatr Respir Rev 2007;8:275 80. [21] Graphic: ehe relentless rise of carbon dioxide. Climate Change: Vital Signs of the Planet. NASA.

References

[22] Vehicles, Air Pollution, and Human Health. Union of Concerned Scientists, ,www. ucsusa.org/clean-vehicles/vehicles-air-pollution-and-human-health.. [23] Stein L. Environmental sources and forms of fluoride, biologic effects of atmospheric pollutants- fluorides. Washington, DC, N.A.S: National Academy of SciencesNational Research Council; 1971. p. 5 28. [24] Shupe JL. Fluorosis of livestock, air quality monograph No. 69-4. New York: American Petroleum Institute; 1969. [25] Zipkin I. Effects on the skeleton of man, fluorides and human health, World Health Organization monograph No. 59. Geneva: WHO; 1970. p. 185 201. [26] Zipkin I. Air pollutants affecting the performance of domestic animals, agricultural handbook No. 380. U.S. Dept. of Agriculture; 1972. revised 109 pp. [27] Zipkin I, Lee WA, Leone NC, Amer J. Air pollutants and fluorides effects. Pub. Health 1957;47:848. [28] Suttle JW. Effects of fluoride on animals, biological effects of atmospheric pollutants fluorides. Washington, DC, N.A.S. National Academy of Sciences-National Research Council; 1971. p. 133 62. [29] Hobbes CS, Merriman GM. Fluoride and animal’s health. Univ. of Tenn. Agri. Exp. Sta. Bull. no. 351; 1963. p. 24:964. [30] Johnson LC. In: Simons JH, editor. Histogenesis and mechanisms in the development of osteofluorosis, fluorine chemistry, vol. IV. NY: Academic Press; 1965. [31] Greenall L. Industrial fluoride pollution in British Columbia. Vancouver: Canadian Scientific Pollution and Environmental Control Society; 1971. [32] Sutton MA, Dragosits U, Tang YS, Fowler D. Ammonia emissions from nonagricultural sources in the UK. Atmos Environ 2000;34:855 69. [33] Wilson LJ, Bacon PJ, Bull J, Dragosits U, Blackall TD, Dunn TE, et al. Modelling the spatial distribution of ammonia emissions from seabirds in the UK. Environ Pollut 2004;131:173 85. [34] Bobbink R, Hicks K, Galloway J, Spranger T, Alkemade R, Ashmore M, et al. Global assessment of nitrogen deposition effects on terrestrial plant diversity: a synthesis. Ecol Appl 2010;20:30 59. [35] Krupa SV. Effects of atmospheric ammonia (NH3) on terrestrial vegetation: a review. Environ Pollut 2003;124:179 221. [36] Common waste water and waste gas treatment and management systems in the chemical sector, BREF document, European IPPC Bureau, ,http://eippcb.jrc.es.; 2002. [37] Pitcairn CER, Leith ID, Sheppard LJ, Sutton MA, Fowler D, Munro RC, et al. The relationship between nitrogen deposition, species composition and foliar nitrogen concentrations in woodland flora in the vicinity of livestock farms. Environ Pollut 1998;102:41 8. [38] Sheppard LJ, Leith ID, Crossley A, Dijk N, Fowler D, Sutton MA, et al. Stress responses of Calluna vulgaris to reduced and oxidised N applied under ‘real world conditions’. Environ Pollut 2008;154:404 13. [39] Van den Berg LJL, Peters CJH, Ashmore MR, Roelofs JGM. Reduced nitrogen has a greater effect than oxidised nitrogen on dry heathland vegetation. Environ Pollut 2008;154:359 69. [40] Wiedermann MM, Gunnarsson U, Nilsson MB, Nordin A, Ericson L. Can smallscale experiments predict ecosystem responses? An example from peatlands. Oikos 2009;118:449 56. [41] Economopoulos. 1993. Air Pollution Management- ILO Encyclopadia.

199

Index Note: Page numbers followed by “f” and “t” refer to figures and tables, respectively.

A Absolute liability, 17 18 Absolute obligations and due diligence, 17 ABT Summer, 85t Accidental spills and leaks, 146 148 Achromobacter, 88 Acid and chelator soil washing, 161 Acid rain, 84, 150 151, 170, 171f formation of, 175f Acinetobacter, 88 Activated carbon (AC), 30 32, 62, 197 Activated-sludge bioscrubber, 196f Activated-sludge scrubber, 197 Active sludge/trickling filter techniques, 94 Adsorption cycles, 63f for CO2 separation process, 63t Aerobic bioremediation, 33 35 Aerobic metabolism, 33 34 Aerobic microbes, 29, 119 120, 195 Aerobic respiration, 33 34 Agenda 21, 4 Agriculture, as source of GHGs, 48 Air (Prevention and Control of Pollution) Act (1981), 189 Air pollutants, 172 179 atmosphere as primary sink of, 170 172 mesosphere, 172 stratosphere, 170 172 thermosphere, 172 troposphere, 170 gaseous pollutants, 173 176 ammonia (NH3), 176 carbon monoxide (CO), 175 in China, 174 chlorine, 176 fluoride, 175 176 hydrogen chloride (HCl), 176 in India, 174 nitrogen oxides (NOx), 174 175 sulfur oxide, 174 in United States, 174 volatile organic compounds (VOCs), 175 odors, 177 179 secondary pollutants, 177 suspended particulate matter, 172 173 types of, 172, 173f Air pollution, 74 78 biological treatment of, 195 197

trickling-filter scrubbers, 197 clean air implementation, 180 183 nitrogen dioxide, 182 ozone, 182 sulfur dioxide, 182 183 control of particulates, 192 195 dry industrial scrubber, 194 electrostatic precipitators, 195 wet industrial scrubber, 193 194 regulation of, 183 192 Australia, 185 Brazil, 185 186 Canada, 186 187 China, 187 188 European Union, 183 185 France, 189 India, 188 189 Israel, 190 Japan, 190 191 South Africa, 191 Switzerland, 191 192 United Kingdom, 192 United States, 189 190 Air Pollution Control Act, 189 191 Air Quality Act, 189 191 Air quality development, filling gap in improving, 8 9 Air sparging, 26, 30 32, 156 Alcanivorax, 88 Aldehyde, 173 174 Aldrin, 149t Algenol, 126 127 biofuels, 46 Alkanes, 89f, 90 Alkanolamines, 58t, 60 61 Alphaproteobacteria, 102 Alpine Convention, 162 163 Alternaria, 89 90 Alteromonas, 88 Alum, 94 Aluminum sulfate (Al2(SO4)3), 82 83 Amazon River System, 75t Ambient air pollution, 181, 183, 185 Amino acids, 58t, 60 61 Ammonia, 58t, 173 174, 181 182 Ammonia treatment, 117 Amoco Cadiz, 85t Amur River System, 75t

201

202

Index

Anabaena azolla, 45 Anabaena variabilis, 105 106 Anaerobic atmosphere, 109 Anaerobic bacteria, 100 102 Anaerobic biodegradation, 92 Anaerobic hydrocarbon degradation, 92 Anaerobic respiration, 33 34 Anode, 115 117 Anthraquinone-2,5, 99 Anthropocene extinction, 22 Anthropogenic soil pollution, 146 151 Aqueous amino acid salt, 58t Aqueous-phase conservation and management, 73 hydrogen production, 123 marine microalgae for carbon sequestration or sink, 123 127 marine systems, 74 78 rivers, lakes, and brackish systems, 73 74 sustainable energy management from waterbodies, 96 119 microbial fuel cell. See Microbial fuel cell (MFC) water pollution control regulation, 96 water quality control, 79 95 brine treatment, 79 81 oil spills and grease removal from contaminated water, 84 92 removal of biodegradable organic wastes, 94 removal of other organic materials from wastewater, 94 95 sewage wastewater treatment, 92 94 solid removal technology, 82 83 Aqueous piperzine (PZ), 58t, 61 Archaea for oil spill remediation, 87 89 Arctic Azolla Event, 45 46 Aromatic organic pesticides, 148 149 Article 253, 189 Aspergillus, 89 90 Atlantic Empress/Aegean Captain, 85t Atmosphere as primary sink of air pollutants, 170 172 mesosphere, 172 stratosphere, 170 172 thermosphere, 172 troposphere, 170 Atrazine, 149t Australia, air pollution regulation in, 185 Australian Design Rules (ADR), 185 Australian federal government, 185 Australian’s air pollution regulatory act, 185 Australia’s emission standards, 185 Automobile Recycling Law, 190 191 Azo dye degradation by microbial fuel cell, 121f Azollafiliculoides, 45 46 as carbon capture biological system, 45 46

B Bacteria and archaea, for oil spill remediation, 87 89 Bacterial degradation process, 88 89 Bare soil, 154 Battery manufacturing, 80t Bayer MaterialScience (BMS) CO2-to-plastic, 54 55 “Bermuda triangle” region, 125 126 BHC, 149t Bimetallic nanoparticles, 158 Bioaugmentation, 32 33 Biocatalytic oxidation of organic compounds, 104, 105f Biochemical energy, 104 Biodegradable organic wastes removal, 94 Biodiversity, filling gaps in restoration of, 10 11 Biodiversity data mining, 11 Bioelectrochemical systems, 98 Biofilters, 195 Biofiltration system, 30 32 Biological accumulation/magnification process of toxic materials, 147f Biological fuel cell, 99 Biological oxygen demand (BOD), 79 sensing, 123 Biological sequestration, 45 Biological treatment technologies, 195 Biomagnification, 146 Bioremediation, 32 33 of contaminant soil, 27 Bioscrubbers, 195 advantages, 197 disadvantages, 197 Biosurfactants, 90 92 Biotrickling-filters, 197 Black carbon, 181 182 Board of Management of Public Forests, 186 Botanical Information Network and Ecology Network (BIEN), 11 Brahmaputra River System, 75t Brasicajuncea L., 28 29 Brazil, air pollution regulation in, 185 186 Brazil Environmental Policy, 185 186 Brazil Institute of Environment, 186 Brazil Institute of Environment and Renewable Natural Resources (IBAMA), 185 186 Brine treatment, 79 81 Brownfield site, 23 Brundtland Commission, 3 4 Building law, 164 Burkholderia, 88 1,3-Butadiene, 175

Index

C Calcium oxide, 61 Canada, air pollution regulation in, 186 187 Canada’s Nationally Determined Contribution (NDC), 186 187 Canadian Environmental Protection Act (CEPA), 187 Canadian Environmental Quality Guidelines, 23 24 Candida, 89 90 Candida apicola, 92 Candida maltose, 92 Candida tropicalis, 92 Carbon capturing process, commercialization of, 52 55 Bayer MaterialScience CO2-to-plastic, 54 55 Covestro manufacturing plastic from carbon dioxide, 55 George Olah carbon dioxide recycling plant, 53 54 solar energy and hydrogen research (ZSW), 52 53 Carbon dioxide, 43, 55, 174 Carbon dioxide adsorption, different cycle for, 62 65 cryogenic distillation, 62 64 hollow fiber membrane, 65 membrane separation, 64 inorganic membrane, 64 mixed matrix membrane, 65 polymeric membrane, 64 65 Carbon dioxide capture, 60f basic approaches of, 57f and recycling, natural process of, 50f Carbon dioxide separation methods, 55 62 absorption, 57 61 nature of solvent, 60 61 adsorption, 61 physical, 62 methods on, 56f solvents for, 58t Carbon electrodes, 116 Carbon fiber, 116 117 Carbon monoxide (CO), 49, 148, 151, 173 175 Carbon-neutral fuel, 49 methods for, 49 Carbon paper, 117 118 Carbon Recycling International (CRI), 50 51 Carbon sequestration process, 44 52 biological process, 45 48 agriculture, 48 Azollafiliculoides as carbon capture biological system, 45 46

forestry residues, 48 marine algae as source of alternate fuel, 46 48 chemical technology for carbon capture, 49 52 methods for carbon-neutral fuel, 49 synthetic hydrocarbon from flue gas, 49 52 Carbon sequestration/sink, marine microalgae for, 123 127 Cartagena Protocol, 162 163 Cartagena Protocol on Biosafety to the Convention on Biological Diversity, 4 5 Castillo de Bellver, 85t Cathode, 117 118 Central Laboratory for Air Quality Monitoring, 189 Central Pollution Control Board (CPCB), 189 Cephalosporium, 89 90 Chang Jiang (Yangtze) River System, 75t Chemical absorption process, 60 61 Chemical oxygen demand (COD), 120 Chemical waste, 148 Chemisorption, 61 Chico Mendes Institute for Biodiversity Conservation (ICMBIO), 186 Chilled ammonia process (CAP), 61 China, air pollution regulation in, 187 188 Chlordane, 149t Chlorella sp., 126t Chlorination, 94 Cladosporium, 89 90 Clay soil, 152 Clean Air Act, 190 Clean Household Energy Solutions Toolkit (CHEST), 182 Climate change, 2 3 framework convention on, 5 Climatic Framework Convention, 162 163 Close Cycle Management Act, 164 Coal-fired power stations, 174 176, 185 Coal mine wastewater treatment process, 83f Coastal and Marine Ecological Classification Standard, 9 10 Cobalt-tetramethoxy-phenylporphyrin (CoTMPP), 117 118 “Command-and-control” regulation, 96 Computer-based mapping, 21 Conceptual development, for clean environment, 1 air quality development, filling gap in improving, 8 9 biodiversity, filling gaps in restoration of, 10 11 developing binding framework of environmental principles, 11 14 environmental governance tools, 13 14

203

204

Index

Conceptual development, for clean environment (Continued) Earth Day, 5 6 ecological restoration, 21 23 environmental management and green economy, 35 37 Green Economy Index, 36 37 green energy for green economy, 37 pillars for green economy success, 36 environmental policy gaps, filling, 6 8 environmental remediation, 23 35 contaminated water remediation, 29 conventional raw water treatment, 29 35 soil remediation types and techniques, 25 29 environmental restoration, 20 21 global climate change regime, 14 15 laws of environmental liability, 18 20 liability for environmental damage, 15 18 absolute liability, 17 18 fault liability, 16 17 marine pollution, filling gaps in monitoring, 9 10 from Rio Earth Summit to Earth Day, 3 5 conceptual development of summit, 3 5 Framework Convention on Climate Changes, 5 Conferences of the Parties (COP), 14 Consolidation, 154 Contaminant soil, bioremediation of, 27 Contaminated land management, 144 Contaminated Sites Ordinance, 164 Contaminated soil, preferential management of, 144f Convention on Biological Diversity (CBD), 4 5, 162 163 Convention to Combat Desertification, 162 Conventional raw water treatment process for drinking, 30f Copenhagen Accord, 14 Corfu Channel standard, 16 17 Corporate average fuel consumption (CAFC), 187 188 Cover crops, 155 Covestro AG, 55 Covestro manufacturing plastic, from carbon dioxide, 55 Criteria air contaminants (CAC), 186 187 Crop diversity, 156f Cryogenic distillation, 55, 62 64 Cryogenic separation process, 62 Crypthecodiniumcohnii, 126t Cyanobacteria mutants, 126 Cyanobacteria stock culture, 126 Cycloclasticus, 88

Cyclones, 192 193 Cyclone separator, 193, 194f Cylindrothecasp., 126t Cytochrome P450 (CYP) alkane hydroxylase, 91 Cytochrome P450 (CYP) enzyme, 92

D 2,4-D, 149t Dairy farming, 44 Danube River System, 75t Dark fermentation process, 47 48 Data mining, nature of for filling gaps, 7t Declaration of the UN Conference on the Human Environment, 12 Deepwater Horizon, 85t Denitrification, 44 Dense inorganic membrane, 64 Desalination MFCs, 110 Desertification Convention, 162 163 Desulfovibrio desulfuricans, 105 106 Dichlorodiphenyltrichloroethane (DDT), 148 149, 149t Diethanolamine, 58t Dietzia, 88 Directive on Industrial Emissions, 163 Diuron, 149t Dnieper River System, 75t Doha Amendment, 14 Double-chamber microbial fuel cells, 110 111, 111f Dry industrial scrubber, 194 Drylands, 162 Dual-phase vacuum extraction (DPVE) method, 32, 33f

E Earth Day, 5 6 Earthquakes and tsunamis, 151 152 Earth Summit, in Rio de Janeiro, 3 5, 14, 162 163 Earthworms (EWs), 153 Ecological restoration, 21 23, 22f Economic Commission for Europe (ECE), 18 19, 185 Economic instruments, 13 Ecosystem, different stages of remediation of, 24f Effluent, 92 Electricity generation directly from plants, 121 123 Electricity production, 44 Electric power plants, 80t Electric swing adsorption (ESA), 62, 63f Electrodialysis, 79

Index

Electron carriers, 99, 106 Electron transfer mechanisms, 100f, 107f Electron transport chain, 99, 101 Electrostatic precipitators, 192 193, 195 Emission-to-liquid (ETL) technology, 53 54 Encapsulation, 25 26, 159 Energy storage tank, 120 Enterobacter, 88 Enterococcus faecalis, 102 Enterococcus gallinarum, 102 EnvironAtlas, 7 Environmental Action Program, 163 164 Environmental full cost accounting (EFCA), 35 36 Environmental Liability Act, 18 Environmental Permitting Regulations (EPR), 144 Environmental policy gaps, filling, 6 8 Environmental protection laws, 18 20 Environmental Quality Index (EQI), 8 Environmental remediation, 23 35 tools and techniques used in, 24 35 contaminated water remediation, 29 conventional raw water treatment, 29 35 soil remediation types and techniques, 25 29 Environmental restoration, 20 21 Environment and Climate Change Canada (ECCC), 187 Environment impact assessment, 144 Environment Protection Regulation Act (EP Act), 143 144 Escherichia coli, 105 Estuaries, 9 10, 74 ETH Zurich technology, 49 EU Air Pollution Act, 192 Euro 5 emission standards, 185 Europe air pollution act, 183 184 European Community (EC), 96 European law, 163 164 European Parliament and Council on Industrial emission, 183 184 European Pollutant Release and Transfer Register (E-PRTR) emission data, 184 European Union, 23 24, 144 air pollution regulation in, 183 185 European Union Emission Trading Scheme, 13, 192 Ex situ immobilization technique, 158 Ex situ remediation technique, 161 Ex situ vitrification, for soil remediation, 160 161

F Fault liability, 16 17 Federal Building Code, 164 Federal Parliament, 186 187

Federal Soil Protection Act, 164 Fergana Valley, 85t Fermentation, 33 34, 47 48 Fertilizer Act, 164 Flocs, 94 Flood, 152 Flue gas, 44, 49 50, 57 60 Fluorinated solvent, 58t Fluorocarbons Management Act, 190 191 Food and Agriculture Organization (FAO), 18 19 Food processing industry, 80t, 82 83 Food processing plans, 80t Forestry residues, 48 Formaldehyde, 177 Framework Convention on Climate Changes, 5 United Nations Convention to Combat Desertification (UNCCD), 5 France, air pollution regulation in, 189 French air quality regulation, 189 Fusarium, 89 90

G Gaocladium, 89 90 Gaseous contaminants, 197 Gaseous fluorides, 176 Gaseous pollutants, 172 176 ammonia (NH3), 176 carbon monoxide (CO), 175 China, 174 chlorine, 176 fluoride, 175 176 hydrogen chloride (HCl), 176 India, 174 nitrogen oxides (NOx), 174 175 sulfur oxide, 174 United States, 174 volatile organic compounds (VOCs), 175 Gas scrubber, 195 197 General Assembly and Security Council, 18 19 Geneva Convention on Long-range Transboundary Air Pollution (1979), 3 Geobacter metallireducens, 102 103, 105 Geobacter sulfurreducens, 102 105, 104f George Olah carbon dioxide recycling plant, 53 54 Geotextiles, 155 Geotextile sand bags, 155f Geotrichum, 89 90 German Federal Ministry of Education and Research (BMBF), 54 55 German Renewable Act, 37 Global annual mean temperature curve, 42 43 Global Biodiversity Information Facility (GBIF), 11

205

206

Index

Global climate change regime, 14 15 Global CO2 emissions, 15f Global Green Economy Index (GGEI), 36 37 Gluconeogenesis, 90 91 Glycol, 58t Glycol carbonate, 58t Good mediators, 106 Gram-positive bacteria, 97 98 Granulated activated carbon (GAC), 29 30 Graphene oxide (GO), 109 Graphite, 117 Great Lakes Water Quality Agreement (1978), 3 Green crude, 47 Green economy, 35 37 green energy for, 37 Green Economy Index, 36 37 Green Economy Roadmap, 36 Green economy success, pillars for, 36 Green energy technology, 97, 119 120 Greenhouse effect, 41 43, 42f, 191 Greenhouse gases (GHGs), 41 65 carbon capturing process, commercialization of, 52 55 Bayer MaterialScience CO2-to-plastic, 54 55 Covestro manufacturing plastic from carbon dioxide, 55 George Olah carbon dioxide recycling plant, 54 55 solar energy and hydrogen research (ZSW), 52 53 carbon dioxide adsorption, different cycle for, 62 65 cryogenic distillation, 62 64 hollow fiber membrane, 65 membrane separation, 64 mixed matrix membrane, 65 polymeric membrane, 64 65 carbon dioxide separation methods, 55 62 absorption, 57 61 adsorption, 61 carbon sequestration process, 44 52 biological process, 45 48 carbon capture, chemical technology for, 49 52 history, 41 43 separation, 55 62 sources of, 43 44 dairy farming, 44 electricity production, 44 transport systems, 43 44 Groundwater, 30 32 biological treatment of, 32 33 Groundwater contaminates, 33 34 Groundwater contamination process, 31f Gulf War oil spill, 85t

H Halogen compounds, 173 174 Halogen derivatives, 173 174 Health Economic Assessment Tool (HEAT), 182 Heavy metals, 28 29, 109, 145 146, 149 150 Helianthus annuus L., 28 29 Helsinki Agreement (1985), 3 High-molecular-weight hydrocarbons, 90 Hollow fiber membrane, 65 Holocene extinction, 22 Home Appliances Recycling Law, 190 191 Household air pollution, 181 182 Huang Ho River (Yellow River) System, 75t Human Ecology Symposium, 5 6 Hydogen fluoride (HF), 175 176 Hydrocarbon clastic bacteria, 88 Hydrocarbon-consuming bacteria, 88 Hydrocarbon degradation process, 88 Hydrocarbon-degrading bacteria, 88, 90 Hydrocarbon-degrading fungi, 89 90 oil spill degrading algae and cyanobacteria, 90 Hydrocarbons, 84, 173 174 Hydrocyclone, 193 Hydrofluorocarbons, 55 Hydrogen chloride (HCl), 176 Hydrogen production, 123 Hydrogen sulfide (H2S), 148, 151, 173 174, 177 178 2-Hydroxy-1,4-naphthoquinone (HNQ), 105 106

I IED Article 73, 185 India, air pollution regulation in, 188 189 Indoor smoke, 181 Indus River System, 75t Industrial air pollution sources pollutants associated with, 179t Industrial Emissions Directive (IED), 183 184 best available technologies, 184 environmental inspection, 184 flexibility, 184 integrated approach, 184 right to participate, 184 Industrial manufacturing process, 181 Industrial oil contamination, 80t Industrial wastewater, sources of, 80t Information technology (IT), 6 Inorganic toxic compounds, 149 150 In situ anaerobic bioremediation, 34 In situ bioremediation (ISB), 27f, 32 33 In situ immobilization process, 159 In situ oxidation, 29 In situ soil remediation, by vitrification, 160f In situ vitrification (ISV), for soil remediation, 160 Integrated Ocean Observing System (IOOS), 9

Index

Integrated Transport and Health Impact Modelling Tool (ITHIM), 182 Intergovernmental Panel on Climate Change (IPCC), 42 43 International Agency for Research on Cancer (IARC), 181 International Atomic Energy Agency (IAEA), 18 19 International Chamber of Commerce (ICC), 36 International Civil Aviation Organization (ICAO), 19 20 International Environmental Law (IEL), 11, 20 International Labor Organization (ILO), 19 20 International Law Commission’s (ILC’s) Draft Articles on State Responsibility, 17 International Maritime Organization (IMO), 18 19 International Monetary Fund (IMF), 35 36 Ionic liquid, 58t Iron(II) sulfate (FeSO4), 82 83 Iron(III) chloride (FeCl3), 82 83 Iron and steel industry, 80t Iron and steel processing, 80t Irrawaddy River System, 75t Irtysh River System, 75t Israel, air pollution regulation in, 190 Ixtoc I, 85t

J Japan, air pollution regulation in, 190 191 Japan legislation, 190 191

K Kocuria, 88 Krebs cycle, 99 Kuwaiti Oil Fires, 85t Kuwaiti Oil Lakes, 85t Kyoto Protocol, 14, 20

L Lakes, 73 74 Lakeview Gusher, 85t Land Degradation Neutrality (LDN), 5, 162 Landfill leachate, 119, 121 Law on Prevention and Control of Air Pollution, 187 Laws of environmental liability, 18 20 Lena River System, 75t Liability for environmental damage, 15 18 types of, 16 18 absolute liability, 17 18 fault liability, 16 17 Light detection and ranging (LIDAR) technology, 9 10

Lithium salt, 61 Living modified organisms (LMOs), 4 5 Loam soil, 152 Low- and middle-income countries (LMIC), 8, 170, 180

M Mackenzie River System, 75t Madeira River System, 75t Magnesium peroxide, 34 35 Manmade pollution, 146 151 Mariculture-raised cyanobacteria H2 productions by, 127f photobiological H2 production by, 128f Marine algae, 46 48, 123 125 as source of alternate fuel, 46 48 algenol biofuels, 46 sapphire energy, 47 Seambiotic Ltd., 48 solazyme, 47 48 Solix biofuels, 46 47 Marine ecosystems, 9, 87 Marine microalgae, 124 127 for carbon sequestration, 123 127 Marine pollution, filling gaps in monitoring, 9 10 Marine protected areas (MPAs), 9 Marine systems, 74 78 Marinobacter, 88 Marinobacterium, 88 Market-based instruments (MBIs), 13 Marxist economics, 35 36 “Mediator-less” MFC, 99 Mekong River System, 75t Membrane-bound oxidative phosphorylation, 99 Membrane filtration, 29 30 Membrane separation method, 64 inorganic membrane, 64 Mercaptans, 173 174, 177 178 Mesophilic bacteria, 195 196 Mesosphere, 170, 172 Metal carbonates, 61 Metal oxides, 61 Metal plate electrostatic precipitators, 195 Methane, 43, 55, 108, 175 Methanol, 48, 50 51 renewable, 53 54 Methyldiethanolamine (MDEA), 58t, 60 Microbes, 106 Microbial degradation of hydrocarbon, 88f, 91f Microbial film formation, 117 Microbial fuel cell (MFC) applications of, 119 123 biological oxygen demand (BOD) sensing, 123

207

208

Index

Microbial fuel cell (MFC) (Continued) generation of electricity directly from plants, 121 123 microbial fuel cell for landfill, 121 wastewater treatment, 120 bacterial metabolism and electron transfer in, 103 108 components of, 115 119 anode, 115 117 cathode, 117 118 proton exchange membrane, 119 for energy from wastewater, 97 101 factors affecting electricity generation, 108 109 for landfill, 121 power generation in, 109 110 technology, 97 101 types of, 110 115 double-chamber microbial fuel cells, 110 111 plant microbial fuel cell, 112 115 single-chamber microbial fuel cells, 111 112 stacked microbial fuel cell, 112 tubular microbial fuel cell, 115 up flow-style microbial fuel cells, 112 types of microbes in, 102 103 typical MFC, 97f Microbial soil remediation, 27 28 Mineral dusts, 172 173, 181 182 Mines and quarries, 80t Mining and smelting, 150 Ministry of Economy, Trade, and Industry (METI), 191 Ministry of Environment, 186 Ministry of Environmental Affairs, 191 Ministry of Land, Infrastructure, Transport, and Tourism (MLIT), 191 Mississippi River System, 75t Mixed matrix membrane, 65 Monoethanolamine (MEA), 58t, 60 Montreal Protocol on Transboundary Movement of Hazardous Wastes (1988), 3 Motor Vehicle Air Pollution Act, 189 190 Mucor, 89 90 Mulching, 152 153 Multicyclone, 193 Multiple cropping, 155 diversity management by, 155 156 Murray River System, 75t

N Nagoya Protocol, 162 163 on ABS, 4 5 Nanoengineering technology, 117 Nanoparticles, 158

Nanoremediation, 158 for contaminated soil, 158 Nanowires, 99 100 Nano zero-valent iron (nZVI), 158 National Air Pollution Control Program, 186 National Ambient Air Quality Standards, 8 National Atmospheric Pollutant Emissions Reduction Plan, 189 National Clean Air Agreement, 185 National Consortium for Data Science (NCDS), 6 8 National Council of Amazon, 186 National Council of Environment (CONAMA), 185 186 National Council of Water Resources, 186 National Council on Environment, 186 National Environment Protection (Assessment of Site Contamination) Measure 1999 (the ASC NEPM), 143 144 National Environment Protection Measures, 185 National Environment System (SISNAMA), 185 186 National Framework for Air Quality Management, 191 National law, 164 National Low-Carbon Strategy, 189 National Oceanic Atmospheric Administration (NOAA), 9 National Ocean Service (NOS), 9 10 National Pollutant Release Inventory (NPRI), 187 National Transport Commission (NTC), 185 Natural water resources conservation and management, 144 Nature Conservation Act, 164 Nature Conservation Law, 164 165 Neutral red (NR), 99 New Energy Vehicle (NEV) credit system, 187 188 New environmental policy instruments, 13 New instruments of environmental policy, 13 Niger River System, 75t Nile River System, 75t Nitrates, 181 182 Nitric oxide, 173 174 Nitrification, 44 Nitrogen and sulfur air pollution ecological effects caused by, 177f Nitrogen dioxide (NO2), 173 175, 182 Nitrous oxide, 43, 55 Nitzschia sp., 126t Nondegradable hydrocarbons, 196 Nongovernmental organizations (NGOs), 42 43, 170 Nonmethane VOCs (NMVOCs), 175

Index

Nowruz Field Platform, 85t Nuclear industry, 80t

O Obligation of conduct, 17 Obligation of result, 17 Ob River, 75t Oceans, 74 Ochrobactrum sp., 88 89 Odors, 177 179 Offgassing, 151 Office of Superfund Remediation and Technology Innovation (OSRTI), 32 33 Oil pollution, regions of world with, 86t Oil release to water surface, 86f Oil spill degrading algae and cyanobacteria, 90 Oil spills and grease removal from contaminated water, 84 92 bacteria and archaea for oil spill remediation, 87 89 damage caused by oil spills, 87 hydrocarbon-degrading fungi, 89 90 oil spill degrading algae and cyanobacteria, 90 mechanisms of oil spill bioremediation, 90 92 oil spills interaction with waterbodies, 87 Oleispira, 88 One-chamber microbial fuel cell, 112f Ordinance on Biowaste, 164 Organic chemicals manufacturing, 80t Organic contaminants, 159 Organic material loading, 108 Organic materials removal from wastewater, 94 95 Organic wastes, 148 Organisation for Economic Co-operation and Development (OECD), 96 Orinoco River System, 75t Outdoor air pollution, 180 181 Outgassing, 151 Oxidation pathways, 33 34 Oxygen, 33 34, 94, 98, 118 Ozone (O3), 43, 182 Ozone layer, 172 Ozone Layer Protection Act, 190 191 Ozone treatment, 94

P Paecilomyces, 89 90 Pandoraea, 88 Pan European Program on Transport Health and Environment (PEP), 183 Paraguay River System, 75t Parana River System, 75t

Paris Agreement, 14 15, 190 Particulate matter (PM), 181 183 nitrogen dioxide, 182 ozone, 182 sulfur dioxide, 182 183 Particulate pollutants, 173 Particulates, control of, 192 195 dry industrial scrubber, 194 electrostatic precipitators, 195 wet industrial scrubber, 193 194 Penicillium, 89 90 Perfluorocarbons, 55 Peroxide compounds, 34 35 Peroxyacetyl nitrate (PAN), 177 Pesticides, 148 149 persistence time for, 149t Pests and nutrients efficiency, managing, 153 154 Petroleum-derived products, types of, 34f Petroleum refineries, 80t Phaeodactylum tricornutum, 126t Photosynthesis, 48, 122 Physical absorption process, 60 Physisorption, 62 Phytoremediation methods, 27 28, 28f Plant microbial fuel cell (PMFC), 112 115, 114f, 122f Pleurotus, 89 90 Plexiglas cylinder, 112 “Polluter pays principle” (PPP), 96 Polychlorinated biphenyls (PCBs), 28 29, 146 Polyether polycarbonate polyols (PPPs), 54 55 Polymeric membrane, 64 65 Polyporus, 89 90 Polyurethanes, 54 55 Populus deltoids, 28 29 Porous inorganic membrane, 64 Power-to-gas (P2G) process, 52 53, 52f Power-to-Gas Baden-Wuttemberg, 52 53 Preoxidation, 29 30 Pressure-driven process, 64 Pressure swing adsorption (PSA), 62, 63f Price-based instruments, 13 Prochiorococcus, 90 Proteobacteria, 102 Proteus vulgaris, 105 Proton exchange membrane, 119 Pseudomonas, 88 Pseudomonas aeruginosa, 88 89 Pulp and paper industry, 80t Pure Earth (New York), 170 Purus River System, 75t

R Radioactive materials, 18, 145 146, 148

209

210

Index

Radioactive pollutants, 150 Radionuclides, 150, 161 Raw water treatment, conventional, 29 35 Rectisol, 58t Regional planning law, 164 Registration, Evaluation, Authorization and Restriction of Chemicals (REACH), 163 Regulatory instruments, 13 14 Reid vapor pressure (RVP), 189 190 Renewable Natural Resources (IBAMA), 186 Reverse osmosis, 79 Rhodoferax ferrireducens, 105 Rhodopseudomonas palustris, 103 104, 110t Rhodotolura, 89 90 Rio Conference, 3 Rio Declaration, 96 Rio Declaration on Environment and Development, 4, 12 Rio Forest Principles, 4 River systems, 73 in the world, 75t River water contamination, by garbage, 78f Rizopus, 89 90 Road Transport Vehicle Act, 191

S Saccharomyces, 89 90 Salween River System, 75t Sao Francisco River System, 75t Sapphire energy, 47 Schizochytrium sp., 126t Scrubber air pollution control devices, 193 Scrubbers, 193 Seambiotic Ltd., 48 Seas, 74 Seashore contamination, 78f Seawater for synthetic liquid fuel, 51 Secondary pollutants, 173, 177 Sedimentation methods, 82 83 Selexol, 58t Sewage Sludge Ordinance, 164 Sewage wastewater treatment, 92 94 primary treatment, 92 93 secondary treatment, 93 tertiary treatment, 94 Shewanella oneidensis, 102, 103f Shewanella putrefaciens, 103f, 105 Shewanella spp., 102 Short-chain alkanes, 90 Silicon tetrafluoride, 176 Simazine, 149t Single-bed CO2 adsorption process, 62 Single-chamber microbial fuel cells, 111 112 Sludge, 92 93

Society for Ecological Restoration (SER), 22 Sodium chloride, 181 182 Soil-based microbial fuel cells (SMFCs), 110 Soil buffering, 153 154 Soil compaction, 151, 154 Soil contamination, 25, 146, 156 due to wastes disposal, 148 Soil erosion, 151 Soil management, strategies for, 143 major soil pollutants, 146 152 manmade, 146 151 natural causes of soil pollutants, 151 152 physical, chemical, and biological methods, 157f soil pollution, control of, 156 162 immobilization techniques, 158 161 nanoremediation for contaminated soil, 158 soil washing, 161 162 soil pollution control, regulatory aspects of, 162 165 building law and regional planning law, 164 Close Cycle Management Act, 164 European law, 163 164 international law for soil protection, 162 163 national law, 164 Nature Conservation Law, 164 165 soil quality management, 152 156 diversity management by multiple cropping, 155 156 excessive tillage, avoiding, 153 ground, coverage of, 154 155 moisture, 152 153 organic matter, enhancing, 153 pests and nutrients efficiency, managing, 153 154 soil compaction, preventing, 154 Soil organic matter, 153, 163 164 Soil pollutants, 146 152 manmade, 146 151 natural causes of, 151 152 earthquakes and tsunamis, 151 152 flood, 152 volcanic eruption, 151 Soil pollution, control of, 156 162 immobilization techniques, 158 161 ex situ vitrification, 160 161 in situ vitrification (ISV), 160 solidification, 159 nanoremediation for contaminated soil, 158 regulatory aspects of, 162 165 building law and regional planning law, 164 Close Cycle Management Act, 164 European law, 163 164 international law for soil protection, 162 163 national law, 164

Index

Nature Conservation Law, 164 165 soil washing, 161 162 Soil protection, 163 164 Soil quality management, 152 156 diversity management by multiple cropping, 155 156 excessive tillage, avoiding, 153 ground, coverage of, 154 155 moisture, 152 153 organic matter, enhancing, 153 pests and nutrients efficiency, managing, 153 154 soil compaction, preventing, 154 Soil remediation types and techniques, 25 29 Soil vapor extraction (SVE) method, 26 27 Soil washing, 25, 161 162 systems, 161 water formulations, 161 162 Solar energy and hydrogen research (ZSW), 52 53 Solazyme, 47 48 Solidification, 159 Solid removal technology, 82 83 Solix biofuels, 46 47 Sorghastrum nutans, 28 29 South Africa, air pollution regulation in, 191 Soviet Cosmos 954 satellite, 17 18 Special Report on Climate Change and Land (SRCCL), 42 43 sPlot Core Team, 11 Stabilized sludge, 93 Stacked microbial fuel cell, 112 Stainless steel noncorrosive electrode, 116 Stapphylococcus, 88 State Pollution Control Board (SPCB), 189 Stenotrophomonas maltophilia, 88 89 Stockholm conference, 3 Stockholm Declaration, 16 17, 188 189 Stratosphere, 170 172 Stream-Catchment (StreamCat), 7 Streptobacillus, 88 Streptococcus, 88 Subsoil compaction, 154 Sulfate, 92, 181 182 Sulfur dioxide (SO2), 173 174, 182 183 Sulfur hexafluoride, 55 Sulfur trioxide, 173 174 Sunflower plants, 29, 29f Suspended particulate matter (SPM), 172 173 Sustainable Development Goals, 98, 182 Sustainable energy management, from waterbodies, 96 119 microbial fuel cells, 102 115

bacterial metabolism and electron transfer in, 103 108 components of, 115 119 factors affecting electricity generation, 108 109 power generation in, 109 110 types of, 110 115 types of microbes in, 102 103 microbial fuel cell technology for energy from wastewater, 97 101 Sustainable Transport Health Assessment Tool (STHAT), 182 Switzerland, air pollution regulation in, 191 192 Synnechococcus, 90 Synthetic hydrocarbon, 51 from flue gas, 49 52 Synthetic liquid fuel, seawater for, 51

T Talaromuces, 89 90 Tarim River System, 75t Taylor energy, 85t Technology entertainment design (TED), 183 184 Temperature swing adsorption (TSA), 62, 63f TerraVia, Holding Inc., 47 48 Tetraselmis suecia, 126t Textile dying, 80t Thallassolituus, 88 Thermal soil remediation, 25 Thermal treatment technology, 25, 25f Thermochemical conversion process, 49 Thermosphere, 172 Thiobacillus ferrooxidans, 106 Thionin, 105 Tigris River System, 75t Tillage, 153 Torulopsis, 89 90 Total energy consumption, 96 Trail smelter rule, 16 Transport Canada (TC), 187 Transport systems, 43 44 Treaty-management, 19 20 Tricarboxylic acid cycle, 90 91 2,3,4-Trichlorobenzene, 149t Trickling biofilter, 94 Trickling filter, 94, 95f Trickling-filter scrubbers, 197 Troposphere, 170 gaseous composition of, 171f Tubular cathode, 115 Tubular microbial fuel cell, 115 Tubular up-flow air-cathode microbial fuel cell, 116f

211

212

Index

U UN and Economic Commission for Europe (ECE) standards, 185 UNCCD 2018 2030 Strategic Framework, 162 UN Climate Change Conference, 14 UN Education, Scientific, and Culture Organization (UNESCO) Conference, 5 6 UNEP Green Economy, 35 UNESCO, 19 20 UN General Assembly, 20 United Kingdom, air pollution regulation in, 192 United Nations (UN) General Assembly, 3 United Nations Conference on Environment and Development (UNCED), 2 3 United Nations Conference on Human Environment, 3 United Nations Convention to Combat Desertification (UNCCD), 5, 162 163 United Nations Environmental Program (UNEP), 3, 11 12, 42 43 United Nations Framework Convention on Climate Change (UNFCCC), 5, 42 43, 162 163 United Nations General Assembly, 42 43 United States, air pollution regulation in, 189 190 United States federal law, 189 190 Universal sink, 146 UN Sustainable Development Goal 14 (SDG 14), 9 Up-flow membraneless microbial fuel cell (UFML MFC), 120 Up flow style microbial fuel cells, 112, 113f Ural River System, 75t US Environmental Protection Agency (US EPA), 6 8, 46, 84, 143 144, 189 190 US Naval Research Laboratory (NRL), 51 52 US Public Health Service, 5 6, 189 190

V Vacuum swing adsorption (VSA), 62, 63f Vietnam Moratorium Committee, 5 6 Vitrification process, 160 Volatile organic compounds (VOCs), 161 Volcanic eruption, 151 152, 192 Volga River System, 75t Voluntary agreements, 13, 191 Voluntary instruments, 13

W Waste Framework Directory, 163 Waste management regulations, 164 Wastes management, 144

Wastewater treatment, 120 sequential stages of, 93f Water Act (1974), 189 Waterbodies contamination of, 29 oil spills interaction with, 87 Water pollutants, 79 Water pollution control regulation, 96 Water quality control, 79 95 biodegradable organic wastes removal, 94 brine treatment, 79 81 oil spills and grease removal from contaminated water, 84 92 bacteria and archaea for oil spill remediation, 87 89 damage caused by oil spills, 87 hydrocarbon-degrading fungi, 89 90 mechanisms of oil spill bioremediation, 90 92 oil spills interaction with waterbodies, 87 organic materials removal from wastewater, 94 95 sewage wastewater treatment, 92 94 primary treatment, 92 93 secondary treatment, 93 tertiary treatment, 94 solid removal technology, 82 83 Water quality management, 144 Water remediation, contaminated, 29 Water resource management, 96 Water treatment industries, 80t Water vapor, 43, 55 Weak acid cation exchange, 79 Web-based Interspecies Correlation Estimation (Web-ICE), 7 8 Wet industrial scrubber, 193 194 Wetlands, 21, 88, 119, 121 122 World Bank, 8, 35 36 World Commission on Environmental and Development (WCED), 17 18 World Health Organization (WHO), 18 19 World Meteorological Organization, 42 43 World Metrological Organization, 18 19

Y Yenisei River System, 75t Yukon River System, 75t

Z Zaire River (Congo River) System, 75t Zambezi River System, 75t