Advanced and Emerging Technologies for Resource Recovery from Wastes (Green Chemistry and Sustainable Technology) [1st ed. 2021] 9811592667, 9789811592669

Citation preview

Green Chemistry and Sustainable Technology

Laleh Nazari Chunbao (Charles) Xu Madhumita B. Ray

Advanced and Emerging Technologies for Resource Recovery from Wastes

Green Chemistry and Sustainable Technology Series Editors Liang-Nian He State Key Lab of Elemento-Organic Chemistry, Nankai University, Tianjin, China Pietro Tundo Department of Environmental Sciences, Informatics and Statistics, Ca’ Foscari University of Venice, Venice, Italy Z. Conrad Zhang Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China

Aims and Scope The series Green Chemistry and Sustainable Technology aims to present cutting-edge research and important advances in green chemistry, green chemical engineering and sustainable industrial technology. The scope of coverage includes (but is not limited to): – Environmentally benign chemical synthesis and processes (green catalysis, green solvents and reagents, atom-economy synthetic methods etc.) – Green chemicals and energy produced from renewable resources (biomass, carbon dioxide etc.) – Novel materials and technologies for energy production and storage (bio-fuels and bioenergies, hydrogen, fuel cells, solar cells, lithium-ion batteries etc.) – Green chemical engineering processes (process integration, materials diversity, energy saving, waste minimization, efficient separation processes etc.) – Green technologies for environmental sustainability (carbon dioxide capture, waste and harmful chemicals treatment, pollution prevention, environmental redemption etc.) The series Green Chemistry and Sustainable Technology is intended to provide an accessible reference resource for postgraduate students, academic researchers and industrial professionals who are interested in green chemistry and technologies for sustainable development.

More information about this series at http://www.springer.com/series/11661

Laleh Nazari Chunbao (Charles) Xu Madhumita B. Ray •

•

Advanced and Emerging Technologies for Resource Recovery from Wastes

123

Laleh Nazari Department of Chemical and Biochemical Engineering Western University London, ON, Canada

Chunbao (Charles) Xu Department of Chemical and Biochemical Engineering Western University London, ON, Canada

Madhumita B. Ray Department of Chemical and Biochemical Engineering Western University London, ON, Canada

ISSN 2196-6982 ISSN 2196-6990 (electronic) Green Chemistry and Sustainable Technology ISBN 978-981-15-9266-9 ISBN 978-981-15-9267-6 (eBook) https://doi.org/10.1007/978-981-15-9267-6 © Springer Nature Singapore Pte Ltd. 2021 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature Singapore Pte Ltd. The registered company address is: 152 Beach Road, #21-01/04 Gateway East, Singapore 189721, Singapore

To my beautiful daughter, Helia, who inspired me to start writing this book. You make me want to be the best version of myself and you will always be the miracle of my life. And to my wonderful husband, Sadra, who is my greatest support, my biggest comfort, and my strongest motivation. Thank you for helping me to make this happen. —Laleh

Preface

This book provides information on waste generation and introduces the technologies to recover energy and resources from different waste streams as an environmentally friendly option for waste management. Economic development and population growth have resulted in a rise in waste generation from residential, industrial, and commercial establishments, which consequently increased environmental and health concerns in urban regions in many parts of the world. Waste handling and management are critical challenges that societies are facing today. The 4R principle (reduce, reuse, recycle, and recover) has been widely used in solid waste management, specifically, to reduce consumption at the source, reuse goods as much as possible, recycle to the maximum, and recover energy or resources. An important aim of this book is to introduce different types of energy and resources that can be recovered from various waste streams such as municipal wastewater and sludge, e-waste, waste plastics and resins, crop residues, forestry residues, and lignin. The book provides an overview of waste generation and characterization as well as their health and environmental impacts. It also includes an introduction to conventional and advanced technologies for waste management such as landfilling, incineration, pyrolysis, hydrothermal liquefaction, fractionation, de-polymerization, gasification, and carbonization. Each chapter discusses various technologies to recover energy and resource from a specific waste stream via converting them into high-value chemicals and materials. The book can serve as an essential guide to dealing with various types of wastes and the methods of disposal, recovery, recycling, and reuse. As such it is a valuable resource for a wide readership, including graduate students, academic researchers, industrial researchers, and practitioners in chemical engineering, waste management, waste to energy and resources conversion, and biorefinery. London, Canada January 2021

Laleh Nazari, PhD, P.Eng Chunbao (Charles) Xu, PhD, P.Eng, FCIC, FCAE Madhumita B. Ray, PhD, P.Eng

vii

Contents

1 Wastes Generation, Characterization, Management Strategies and Health and Environmental Impacts . . . . . . . . . . . . . . . . . 1.1 Wastes Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 Wastes Characterization . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2.1 Hazardous Wastes . . . . . . . . . . . . . . . . . . . . . . . . . 1.2.2 Non-hazardous Wastes . . . . . . . . . . . . . . . . . . . . . . 1.3 Waste Management Strategies . . . . . . . . . . . . . . . . . . . . . . 1.3.1 Waste Management Hierarchy . . . . . . . . . . . . . . . . 1.3.2 Waste Management Strategies in Canada . . . . . . . . 1.4 Health and Environmental Impacts of Wastes and Waste Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.1 Impacts of Waste on Human Health and the Environment . . . . . . . . . . . . . . . . . . . . . . . 1.4.2 Impacts of Waste Management on the Environment . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . .

1 1 3 3 5 9 9 10

.....

15

..... ..... .....

15 22 25

. . . . . . . .

. . . . . . . .

. . . . . . . .

2 Conventional Approaches for Waste Management—A Canadian Perspective . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1 Waste Generation in Canada . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 Conventional Approaches for Non-hazardous Solid Waste Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.1 Landfills . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.2 Thermal Treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3 Conventional Approaches for Hazardous Solid Waste Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4 Waste Diversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4.1 Recycling at Material Recovery Facility (MRF) . . . . . . . 2.4.2 Composting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . .

.. ..

27 28

.. .. ..

29 31 35

. . . .

40 43 45 48

. . . .

ix

x

Contents

2.5 Conventional Approaches for Wastewater Management 2.5.1 Treatment of Municipal Wastewater . . . . . . . . . 2.5.2 Treatment of Industrial Wastewater . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . .

. . . .

. . . .

. . . .

. . . .

. . . .

. . . .

. . . .

49 49 51 52

3 Advanced Technologies (Biological and Thermochemical) for Waste-to-Energy Conversion . . . . . . . . . . . . . . . . . . . . 3.1 Thermochemical Conversion Technologies . . . . . . . . . . 3.1.1 Combustion . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1.2 Pyrolysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1.3 Hydrothermal Liquefaction . . . . . . . . . . . . . . . . 3.1.4 Gasification . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2 Biochemical Conversion Technologies . . . . . . . . . . . . . 3.2.1 Anaerobic Digestion . . . . . . . . . . . . . . . . . . . . 3.2.2 Mechanical Biological Treatment . . . . . . . . . . . 3.2.3 Fermentation . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . .

. . . . . . . . . . .

. . . . . . . . . . .

. . . . . . . . . . .

. . . . . . . . . . .

. . . . . . . . . . .

. . . . . . . . . . .

. . . . . . . . . . .

55 57 57 62 68 73 76 76 81 84 90

. . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . .

97 98 98 98 99 100 100 101 101 104 104 109 114 116 116 118 118

4 Nitrogen and Phosphorous Recovery from Municipal Wastewater and Sludge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1 Wastewater Treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1.1 Preliminary Treatment . . . . . . . . . . . . . . . . . . . . . . . . . 4.1.2 Primary Treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1.3 Secondary Treatment . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1.4 Tertiary Treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1.5 Advanced Treatment Processes . . . . . . . . . . . . . . . . . . . 4.2 Wastewater Sludge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.1 Sludge Treatment Methods . . . . . . . . . . . . . . . . . . . . . . 4.3 Nutrient Removal/Recovery from Wastewater . . . . . . . . . . . . . 4.3.1 Nitrogen Removal/Recovery from Wastewater . . . . . . . . 4.3.2 Phosphorous Removal/Recovery from Wastewater . . . . . 4.3.3 Simultaneous Removal of Phosphorous and Nitrogen . . 4.4 Nutrient Removal/Recovery from Sludge . . . . . . . . . . . . . . . . . 4.4.1 Phosphorous Removal/Recovery from Sludge . . . . . . . . 4.4.2 Nitrogen Removal/Recovery from Sludge . . . . . . . . . . . 4.5 Nutrient Recovery Technologies Across the World . . . . . . . . . . 4.6 Economic Analysis of Nutrient Recovery from Municipal Wastewater and Sludge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.7 Environmental Impacts of the Nutrient Recovery from Municipal Wastewater and Sludge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . 121 . . 122 . . 123

Contents

5 Recovery of Metals from Electronic Waste . . . . . . . . . . . . 5.1 Environmental and Health Issues of Electronic Devices 5.2 International Legislation on E-Waste . . . . . . . . . . . . . . 5.3 Economic Values of E-Waste . . . . . . . . . . . . . . . . . . . 5.4 E-Waste Recycling . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 Recovery of Metals from E-Waste . . . . . . . . . . . . . . . . 5.6 Physical Methods for Metals Recovery . . . . . . . . . . . . 5.7 Thermo-Chemical Methods for Metals Recovery . . . . . 5.7.1 Pyrolysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.7.2 Gasification and Plasma Technology . . . . . . . . . 5.8 Metallurgical Methods for Metals Recovery . . . . . . . . . 5.8.1 Pyrometallurgical Processing . . . . . . . . . . . . . . 5.8.2 Hydrometallurgical Processing . . . . . . . . . . . . . 5.8.3 Recovery of Precious Metals . . . . . . . . . . . . . . 5.8.4 Biometallurgical Processing . . . . . . . . . . . . . . . 5.9 Industrial Applications of E-Waste Recycling . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

xi

. . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . .

127 129 129 130 130 131 132 134 134 135 135 135 138 143 148 152 155

. . . . . .

. . . . . .

. . . . . .

157 158 158 159 161 162

6 Waste Plastics Management and Conversion into Liquid Fuels and Carbon Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.1 Plastics Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.1.1 Synthetic Resins . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.1.2 Additives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2 Plastics Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3 Waste Plastics Generation and Disposal . . . . . . . . . . . . . . . . . 6.4 Conversion of Waste Plastics and Resins into Liquid Fuels and Carbon Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.4.1 Liquid Fuels or Oils from Waste Plastics . . . . . . . . . . 6.4.2 Carbon Materials from Waste Plastics . . . . . . . . . . . . . 6.5 Industrial Application Examples of Waste Plastics Conversion Technologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.6 Economic and Environmental Benefits of Waste Plastics Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . 176 . . . 176

7 Resource Utilization of Agricultural/Forestry Residues via Fractionation into Cellulose, Hemicellulose and Lignin . . . . 7.1 Lignocellulosic Biomass . . . . . . . . . . . . . . . . . . . . . . . . 7.2 Pre-treatments of Lignocellulosic Biomass . . . . . . . . . . . 7.3 Physical Pre-treatment Methods . . . . . . . . . . . . . . . . . . . 7.3.1 Mechanical Methods . . . . . . . . . . . . . . . . . . . . . 7.3.2 Microwave-Assisted Methods . . . . . . . . . . . . . . . 7.3.3 Extrusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.3.4 Ultrasonication . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . .

. . . . . . . .

. . . . . . . .

. . . . . . . .

. . . . . . . .

. . . 163 . . . 163 . . . 166 . . . 172

. . . . . . . .

. . . . . . . .

179 181 182 184 185 185 186 186

xii

Contents

7.4 Chemical Pre-treatment Methods . . . . . . . . . . . . . . . . . . 7.4.1 Acidic Pre-treatment . . . . . . . . . . . . . . . . . . . . . 7.4.2 Alkaline and Kraft Pulping Pre-treatment . . . . . . 7.4.3 Oxidative Pre-treatment . . . . . . . . . . . . . . . . . . . 7.4.4 Organosolv Fractionation Processes . . . . . . . . . . 7.4.5 Fractionation Using Ionic Liquids . . . . . . . . . . . . 7.4.6 Pre-treatment with Deep Eutectic Solvents (DES) 7.5 Physico-chemical Methods . . . . . . . . . . . . . . . . . . . . . . 7.5.1 Steam Explosion (SE) . . . . . . . . . . . . . . . . . . . . 7.5.2 Ammonia-Based Pre-treatment . . . . . . . . . . . . . . 7.5.3 Supercritical Fluid Pre-treatment . . . . . . . . . . . . . 7.5.4 Hydrothermal Processes . . . . . . . . . . . . . . . . . . . 7.6 Biological Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . .

. . . . . . . . . . . . . .

. . . . . . . . . . . . . .

. . . . . . . . . . . . . .

. . . . . . . . . . . . . .

. . . . . . . . . . . . . .

. . . . . . . . . . . . . .

186 187 188 189 191 195 198 198 198 199 200 200 201 202

8 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205

Chapter 1

Wastes Generation, Characterization, Management Strategies and Health and Environmental Impacts

Abstract Waste generation refers to the discarded materials from residential and commercial activities that enforce economic and environmental costs for its management and disposal. The first step in waste management approaches is to reduce the waste generation at the manufacturing or consumer level. This means using fewer natural resources, avoiding waste generation, qualitative and quantitative reduction at source and reuse of products. The next step is to divert waste through recycling and composting. Diversion is performed by reusing and diverting the waste from landfills into new products. It provides cost-effective solutions for hazardous waste and hardto-recycle waste from landfills. The next approach is energy and resource production from waste through incineration, gasification, de-polymerization, pyrolysis, etc. The produced energy is in the form of electricity, heat or steam. The least preferred method for waste management is disposal by landfill and incineration. They are usually the most cost-efficient way to dispose of the waste; however, they are associated with some environmental and health concerns. A good waste management strategy is fundamental for protecting human health, reducing the environmental impacts and enhancing business activities. The waste management approaches and strategies are reviewed in this Chapter. In addition, the Canadian government waste strategy and regulations are reviewed. Keywords Waste generation · Characterization · Hazardous waste · Non-hazardous waste · Waste management strategies · Environmental impacts · Health impacts

1.1 Wastes Generation Waste is referred to any unwanted or unusable material that is disposed after use. It includes all types of waste or side-products generated from residential, institution and commercial establishments. Waste is usually generated in a solid, liquid, or gaseous state as a result of human activities such as living, eating and production and consumption of materials. It is a function of what we purchase and consume in our daily lives. © Springer Nature Singapore Pte Ltd. 2021 L. Nazari et al., Advanced and Emerging Technologies for Resource Recovery from Wastes, Green Chemistry and Sustainable Technology, https://doi.org/10.1007/978-981-15-9267-6_1

1

2

1 Wastes Generation, Characterization, Management Strategies …

The growth of population, industrialization, improved standards of living and most importantly consumerism have resulted in an increase in waste generation, which subsequently raised the concerns on environmental degradation [1]. The greatest increase in waste generation began during the industrial revolution in the nineteenth century and continues today [2]. For instance, the global waste generation increased from 365 Mt in 1965 to 1999 Mt in 2015 [3]. Taking Municipal Solid Wastes (MSW) as an example, current global MSW generation levels climb to over 2 billion tonnes per year [4], and the world-average per capita waste generation rate is approx. 1.2 kg per person per day, or 438 kg per capita [5]. Figure 1.1 presents MSW for disposal (kg per capita) in 20 major OECD (Organization for Economic Co-operation and Development) countries [6]. As shown in the Figure, Canada produced nearly 800 kg per capita of MSW for disposal in 2014, the highest waste generation rate among the 20 countries [7]. This amount of waste generation is well above the average waste generation of around 500 kg per capita for the 16 countries and twice as much as that of Japan. Canada produces a large amount of waste in the form of solid and semi-solid, mainly the oil sands tailings (such as sand and fine tailings), mine tailings, mine waste rock, livestock manure and MSW. The oil sands industry, a major energy producer in Canada, is however, the largest solid waste producer in the country, creating vast and fast-growing quantities of waste every year. In 2008, it generated 645 million tonnes of tailings from surface mining operation [2]. The major environmental threats from oil sands tailings waste include contamination of groundwater and surface water. In Canada, wastewater discharges contribute to the greatest emission of waste by volume into the environment, and according to Statistic Canada municipal wastewater

Fig. 1.1 MSW generation (kg per capita per year) in 20 major countries based on 2014 data. Reprinted with permission from [8]

1.1 Wastes Generation

3

discharges were 6.4 billion tonnes in 2006, and industrial wastewater discharges were 29.9 billion tonnes in 2009 [2].

1.2 Wastes Characterization Generally, wastes generated from residential, industrial and commercial establishments can be classified into hazardous or non-hazardous wastes. Hazardous wastes are materials that are potentially dangerous or harmful to human health or the environment. They cannot be treated by the normal waste and recycling approaches due to their health hazard or environmental harmfulness [2]. Non-hazardous wastes are typically the curbside household garbage and similar wastes generated by businesses and institutions, e.g., printed paper and packaging (such as plastics, paper, glass, aluminum and steel), organics from food and yard waste, tires, cement, metals and glass from construction and demolition [9].

1.2.1 Hazardous Wastes Hazardous waste may be flammable, corrosive or toxic and they usually need special pre-treatments before being disposed or recycled [2]. Transportation of Dangerous Goods Regulations (TDGR) administered by Transport Canada has divided the hazardous waste into nine classes according to their type of danger, as summarized as follows [10–12]: Class 1—Explosives: Explosives are substances that are capable of producing a large amount of gas (vapor) in a short period of time as a result of chemical reactions, generating a high pressure or high-speed blast wave that would damage the surroundings. They can also be explosive or pyrotechnic if exposed to heat, light, and sound, gas or smoke through self-sustaining exothermic chemical reactions. Class 2—Gases: This class of hazardous waste includes a gas, or a mixture of gases with one or more vapors of substances included in other classes. Gases in this category include flammable gases that are ignitable at ambient conditions in a mixture of 13 vol. % or less with air, or toxic gases that are known to be toxic or corrosive to humans, or have a lethal concentration value (LC50 ) less than or equal to 5000 mL/m3 . Class 3—Flammable liquids: This class includes substances that are liquids or liquid solutions or suspension containing solids that have a flashpoint less than or equal to 60 °C or they are intended or expected to be at a temperature greater than or equal to their flashpoint. Class 4—Flammable solids: Substances included in this class are liable to spontaneous combustion, or water-reactive substances that emit flammable gases if they come in contact with water.

4

1 Wastes Generation, Characterization, Management Strategies …

Class 5—Oxidizing substances and organic peroxides: This class includes the substances that yield oxygen and lead or contribute to the combustion of other materials. It also includes organic peroxides which are thermally unstable and contain oxygen in the bivalent “-O-O-” structure, are likely to undergo exothermic self-accelerating decomposition, liable to explosive decomposition, are sensitive to impact or friction, can burn rapidly and react dangerously with other substances and can cause damage to the eyes. Class 6—Toxic and infectious substances: Toxic substances can cause death or serious injury or can cause harm to human health if they are swallowed or inhaled or if they come into contact with skin. Infectious substances contain microorganisms such as bacteria, viruses, rickettsia, parasites, fungi, etc., that can cause disease in humans or animals. Class 7—Radioactive materials: Radioactive materials include the radioactive elements found in the environment such as uranium (U-238 or U-235), thorium (Th232) and potassium (K-40) and any of their radioactive decay products, such as radium (Ra-226) and radon (Rn-222). Class 8—Corrosive substances: This category includes the substances that can cause destruction of human skin, permanent skin lesions, destruction of all layers of the outer skin through to the internal tissues, or exhibit a corrosion rate that exceeds 6.25 mm per year on a solid surface at a test temperature of 55 °C. Class 9—Miscellaneous products, substances or organics: Any other type of hazardous waste that is not included in the previous classification can be in this group, e.g., a marine pollutant and hazardous household wastes, including but not limited to medication, paints or solvents, unwanted engine oil or anti-freeze, dead or unwanted car batteries or any other type of batteries (that contain heavy metals), discarded electronic devices such as cell phones and televisions, and burnt out fluorescent lights/tubes (that contain mercury), etc. The nine classes of hazardous waste are usually represented by dangerous goods safety marks derived from the United Nations-based, as illustrated in Fig. 1.2. Not

Fig. 1.2 Safety labels of hazardous materials [12]

1.2 Wastes Characterization

5

all countries use precisely the same graphics (label, placard and/or text information) in their national regulations [12].

1.2.1.1

Management of Hazardous Waste and Recyclable Materials

In most developed countries, hazardous waste is mostly disposed, but some fractions can be recycled. For instance, in Canada, there are three levels of government that deal with the hazardous waste disposal or recycling: (1) the municipal government is responsible for the collection, recycling, composting and disposal programs, (2) the provincial and territorial governments are responsible for licensing hazardous waste generators, carriers and treatment facilities as well as controlling movements of waste within their authority, and (3) the federal government controls the transboundary movements of hazardous wastes and recyclables and negotiates international agreements with regards to chemicals and wastes [13]. In Canada, imports and exports of hazardous waste and hazardous recyclable materials are controlled by the Canadian Environmental Protection Act 1999 (CEPA 1999). This act controls and tracks the transboundary movement of hazardous waste and hazardous recyclable material between Canada and other countries. In 2010, more than 358,000 tonnes of hazardous waste including solid waste no longer suitable for metal recovery, industrial residues and other environmentally hazardous waste were imported to Canada, mainly from the United States. Almost 60 percent of the total hazardous waste import consisted of recyclable materials such as batteries, metal-bearing waste, liquors from metallurgical processes, lubricating oil and manufacturing residues. In the same year, more than 425,000 tonnes of hazardous waste were exported from Canada of which 83% were recyclable materials and were mainly sent to the United States [2].

1.2.2 Non-hazardous Wastes Non-hazardous waste includes non-recyclable and recyclable materials produced by the residential (households) and Industrial, Commercial and Institutional (IC&I) sector. According to the information from the Ontario Ministry of Environment, approximately 12.5 million tonnes of non-hazardous waste is annually generated in Ontario. About 60% of this waste is generated by the IC&I sectors and the rest is produced by the residential sector [14]. Municipal governments are responsible for collecting and managing the waste generated by the residential sector, while the IC&I sector is responsible for managing the waste they produce. They contract private companies to collect and transport the waste to landfills or to the recycling facilities [14]. Non-hazardous waste can be classified into MSW, natural resource residuals, livestock manure and organic waste (food and yard waste).

6

1 Wastes Generation, Characterization, Management Strategies …

Municipal solid waste (MSW): Commonly known as trash or garbage that is discarded by the public consisting of product packaging, furniture, clothing, old computers, food scraps, bottles and cans, newspapers and appliances. The composition of the MSW varies greatly with municipality and time, and can also be influenced by factors such as culture, economic development, climate, and energy sources. On average, MSW in the world is composed of mainly organic waste (46%), paper (17%), plastic (10%), glass (5%), metal (4%), and other (18%) including textiles, leather, rubber, multi-laminates, e-waste, appliances, ash, other inert materials, as illustrated in Fig. 1.3. The sources of all types of MSW composition are presented in Table 1.1. MSW is commonly disposed in landfills, burned in incinerators or diverted through composting or recycling [2]. Natural resource residuals: Refer to a broad collection of byproducts, generated as a result of extraction and production processes associated with natural resources Miscellaneous, 2% Inerts , 13% Textiles , 3% Metal , 4% Organic, 46%

Glass, 5%

Plastics, 10%

Paper , 17%

Fig. 1.3 Global MSW composition in 2013 [15]

Table 1.1 Types of MSW and their sources. Reprinted with permission from [5] Type

Sources

Organic Food scraps, yard (leaves, grass, brush) waste, wood, process residues Paper

Paper scraps, cardboard, newspapers, magazines, bags, boxes, wrapping paper, telephone books, shredded paper, paper beverage cups. Although paper is mostly organic but unless it is contaminated by food residue, paper is not classified as organic

Plastic

Bottles, packaging, containers, bags, lids, cups

Glass

Bottles, broken glassware, light bulbs, colored glass

Metal

Cans, foil, tins, non-hazardous aerosol cans, appliances (white goods), railings, bicycles

Other

Textiles, leather, rubber, multi-laminates, e-waste, appliances, ash, other inert materials

1.2 Wastes Characterization

7

such as land (including fossil fuels, minerals, etc.), water (oceans, lakes rivers, etc.), soil, plants (including forest, crops, etc.), and animals. Examples of these residuals include waste rocks and overburden, rejected mineral ores and mine tailings from metal and non-metal mining, oil sands mining and processing, agricultural/forestry residues, etc. These residuals can result in the release of chemicals and metals to water and soil [2]. Canada’s oil sands (naturally occurring mixtures of sand, clay or other minerals, water, and bitumen) are the third-largest proven oil reserve in the world, representing 166.3 billion barrels (or 97%) of Canada’s 171 billion barrels of proven oil reserves. It produced 2.2 million barrels of synthetic crude oil per day from oil sands in 2014 [16]. However, as previously mentioned, Canada’s oil sands industry is the largest solid waste producer in Canada, creating vast and fast-growing quantities of waste every year [2]. In 2008, it generated 645 million tonnes of tailings from surface mining operation [2]. Nevertheless, Canada’s oil sands industry is committed to reducing its environmental footprint, reclaiming all lands affected by operations and maintaining biodiversity, and continuing to reduce Greenhouse Gas (GHG) emissions intensity [17]. Agricultural/forestry residues are the main bio-renewable resources worldwide [18, 19]; Table 1.2 provides the estimated annual availability of biomass resources (agricultural/forestry residues). Livestock manure: Livestock manure, a solid waste generated from livestock farms, is an organic matter that can be used as an organic fertilizer in agriculture by providing nutrients such as nitrogen and phosphorous. However, excess manure can result in a spill and pollution of surface water and groundwater. Canadian livestock farms for beef cattle, milk cows and calves produced more than 180 million tonnes of manure in 2006 [2]. According to the Iowa Environmental Council’s analysis (2012), illegal manure spills killed more than 1.2 million fish in Iowa in the prior ten years [23]. Organic waste: Organic waste is referred to as leaf and yard waste, food waste from households and food waste from the IC&I sector, representing about one-third of the total non-hazardous waste [14]. For instance, almost 3.7 million tonnes of food Table 1.2 Estimated annual availability of biomass resources (agricultural/forestry residues) worldwide Country/Region

Production capacity (ton of dry biomass)

BOE (barrels of oil energy equivalent)a

References

U.S

1.3 × 109

3.8 × 109

[18]

China

7.0 ×

20 × 109

[20]

Canada

0.4 × 108

0.13 × 109

[21, 22]

Europe

4.4 ×

1.4 ×

[18]

Africa

1.1 × 109

3.5 × 109

Latin America

1.0 × 109

3.2 × 109

a Each

109 108

109

metric ton of dry biomass equals 3.15 BOE

8

1 Wastes Generation, Characterization, Management Strategies …

Fig. 1.4 Percentage of the total annual food wasted by sector in Canada. Reprinted with permission from [24, 25]

and organic waste was generated in Ontario in 2015, 55% of which is generated by the residential sector and the remaining 45% by the IC&I sector. Figure 1.4 shows the percentage of the total annual food wasted by sector in Canada based on the 2014 data: According to the data from the Canadian Ministry of the Environment and Climate Change in 2017, about $31 billion worth of food was wasted in Canada annually, corresponding to about $868 worth of food wasted per person per year [26].

1.2.2.1

Management of Non-hazardous Waste and Recyclable Material

Non-hazardous waste is either disposed or diverted. In Canada, the disposal of nonhazardous waste is through landfill or incineration and the diversion of non-hazardous waste is through reducing, reusing or recycling. The government of Ontario is responsible for dealing with the non-hazardous waste management through the Ministry of the Environment. Waste management is governed by the Environmental Protection Act (EPA), the Environmental Assessment Act (EAA) and the Waste Diversion Act, 2002 (WDA) [14]. It is also responsible for approving new municipal and privatesector waste management sites, facilities and systems such as lands and buildings and the required equipment [14]. Under the WDA, the provincial government has established an arm’s-length organization called Waste Diversion Ontario (WDO) that is responsible for developing, implementing and operating waste diversion programs for certain wastes and to monitor the effectiveness of the programs [14]. However, with the proclamation of the Waste-Free Ontario Act 2016, the Waste Diversion Ontario was overhauled as the Resource Productivity and Recovery Authority, with the responsibility to oversee programs continued under the Waste Diversion Transition Act 2016 and enforce compliance with regulations established under the Resource Recovery and Circular Economy Act 2016 [27].

1.3 Waste Management Strategies

9

1.3 Waste Management Strategies 1.3.1 Waste Management Hierarchy The waste management hierarchy is a tool for evaluation of the waste management approaches. The waste management sector follows a generally accepted hierarchy that is usually presented in a diagram of a pyramid, as illustrated in Fig. 1.5. The earliest known usage of the ‘waste management hierarchy’ appears to be Ontario’s Pollution Probe in the early 1970s. The hierarchy started as the ‘three Rs’— reduce, reuse, recycle—but now a fourth R is frequently added—recovery (aerobic composting and digestion). The aim of this hierarchy is to generate the maximum amount of beneficial products from the available wastes and minimize waste production. According to the hierarchy, the preferred order of waste management approaches is: Reducing waste at the source (i.e., the green chemistry or green engineering principle) > Reusing the waste > Recycling and composting > Energy and materials recovery (digestion and composting) > disposal (landfill and incineration). However, landfilling is still the most common method for MSW disposal worldwide, with approx. 340 million tonnes of MSW landfilled annually, as illustrated in Fig. 1.6 [5].

Fig. 1.5 Waste management hierarchy. Reprinted with permission from [5]

10

1 Wastes Generation, Characterization, Management Strategies …

Fig. 1.6 Amounts of MSW disposed annually, based on approximate values in various years Worldwide. Reprinted with permission from [5]

1.3.2 Waste Management Strategies in Canada In 2016, local governments across Canada spent $3.3 billion for waste management, including the costs for collection and transportation, disposal/processing facilities and tipping fees [7]. Each province and territory in Canada has its own waste management policy and legislative framework for waste management. Some of the policies include numeric targets for waste diversion or upper limit for waste disposal. For example, Ontario’s Extended Producer Responsibility (EPR) programs had a target of 60% diversion by 2008, and Quebec targeted to achieve 70% recycling, and an upper limit of 700 kg/capita waste disposal by 2015 [7]. However, due to the increasing cost of the waste management, sometimes the targets set by the governments are not met. For example, Ontario’s diversion rate was only 25% in 2016, so new, lower targets were set as 30% waste diversion by 2020, 50% by 2030 and 80% by 2050. However, Quebec was successful in reducing the landfill disposal rate to 685 kg/capita in 2015 [8].

1.3.2.1

Overview of the Current Strategies

Strategy 1: Waste prevention and reduction at source The most important challenge for Canada to achieve more sustainable waste management practices is to prevent and reduce the amount of solid waste generated and increase the amount of waste diverted from landfills by improving the recycling and recovering procedures [6]. Waste prevention and reduction means reducing the amount of waste generated at the source and reducing the hazardous content of the waste. It involves using fewer natural resources, avoiding waste generation, qualitative and quantitative reduction at source and re-use of products [7]. This policy can be applied through two general procedures:

1.3 Waste Management Strategies

11

(a) Upstream waste prevention at the manufacturing level. Strategies for waste prevention include source reduction by increasing source efficiency and minimizing raw material input, improving eco-friendly designs for products and packaging, reorganizing production processes by using the waste of one industry as a valued input to another (industrial ecology approach), transferring additional waste management responsibilities to producers and consumers, and developing and implementing the ISO 14,001 strategy [7, 28]. (b) Consumer or commercial/institutional-level waste prevention. It includes educating and informing consumers about reuse and waste reduction, taking initiatives to limit purchases of disposable products and encourage consumers to buy materials made from recovered or reused items, implementing bulk-purchasing policies and paper usage reduction policies for institutional and commercial sectors [7, 28]. Strategy 2: Waste diversion (recycling and composting) Waste diversion refers to recycling and composting without energy recovery. From 2000 to 2010 in Canada, the total amount of waste diverted to recycling and composted increased by 33% from 6.1 million tonnes to 8.1 million tonnes [7]. Strategies for waste diversion include increasing the opportunity for reuse and recycling, increasing the effectiveness of the existing recycling programs, targeting specific materials and waste streams for reusing, recycling and diversion and targeting specific sectors to improve diversion rates [28]. For instance, there are different recycling and composting programs Canada-wide for various waste streams: Packaging and Printed Paper (PPP), beverage containers, paper, plastic bags, electronic products, household hazardous and special wastes (consumer batteries, aerosols, solvents, mercurycontaining lamps, paint, pharmaceuticals and sharps), automotive products (used oils, containers and filters, glycerol, end-of-life tires and lead-acid batteries). Composting is another option for diversion and refers to the biodegradation of organic waste such as food waste, manure, leave, crop residue, etc., into a valuable organic fertilizer. The composting rate of the organics (food and yard waste) in Canada increased markedly by 125% from 0.98 million tonnes in 2000 to 2.2 million tonnes in 2010 partially due to limited landfill space [7]. Some municipalities in different provinces have introduced specific organic composting programs, as presented in Table 1.3. Residential composting reduces the amount of landfill waste and as a result reduces the amount of GHG emission from the decomposing of organic material in landfills. Table 1.3 Organic composting programs of various Canadian cities [29] Municipality

Composting program

Introduced in

Collection plan

Ottawa

Green bin program

2010

Weekly

Moncton

Wet/Dry waste separation program

1999

Weekly

Hamilton

Green cart program

2006

Weekly

Edmonton

Edmonton waste management centre

2000

Weekly

Vancouver

Food scraps recycling program

2010

Biweekly or weekly

12

1 Wastes Generation, Characterization, Management Strategies …

Table 1.4 Existing large waste to energy conversion facilities in Canada. Regenerated with permission from [7] Facility/Location

Feedstock

Annual volume of waste processed (tonnes/year)

Type of energy generated

Energy from waste facility/Burnaby, BC

MSW, ICI, non-hazardous, non-recyclable residual waste

285,000

Electricity

Wainwright/AB

MSW, ICI, biomedical non-recyclable residual waste

11,000

Steam

Peel Region/ON

MSW, non-hazardous, non-recyclable residual waste

180,000

Electricity

Ville de Quebec/QC

MSW, ICI, sludge, non-hazardous, non-recyclable residual waste

300,000

Steam

Energy from waste facility/PEI

MSW, non-hazardous, non-recyclable and sawmill residual waste

33,000

Steam

Strategy 3: Energy and materials recovery from waste Waste to energy conversion refers to the generation of energy in the form of electricity, heat or steam from waste. The most common methods for waste to energy conversion are thermal treatment (incineration with energy recovery, gasification, de-polymerization and pyrolysis) and non-thermal treatment (anaerobic digestion). Canada has five large waste-to-energy facilities operating that use mixed MSW as the feedstock and convert them into heat or steam, as listed in Table 1.4. Strategy 4: Waste disposal The least preferable but by far the most common waste management strategy in Canada is waste disposal by landfill and incineration. Landfill refers to the burial of waste materials and is the oldest form of waste treatment. They are usually the most cost-efficient way to dispose of the waste. However, there are some environmental and health concerns associated with landfill disposal such as contamination of groundwater by landfill leachate and emission of methane—a GHG, as discussed in the later sections. After recycling and recovering, the residual MSW is landfilled in almost 2000 operating landfill sites across Canada [7]. Each province or territory has specific guidelines and standards for landfill site design and operation of which some include landfill bans for specific materials such as hazardous waste or the materials that can be recycled through recycling programs [7]. Incineration is another option for waste disposal, which refers to the waste thermal treatment process that involves the combustion of organic substances of the waste

1.3 Waste Management Strategies

13

with no energy recovery from the combustion process. This method is less popular than landfilling in Canada. One of the advantages of incineration is the reduction of the overall volume of the waste, however, incineration contributes to air pollution (SOx , NOx , dioxins, PM and heavy metals). There are small and mobile incinerators across the country, except a large MSW incinerator in Quebec (>25 tonnes/day), treating both MSW and small quantities of hazardous waste.

1.3.2.2

New Strategies for Waste Management

Waste management has become a legally, technically and commercially complex process. New development in waste management has been focused on preventing and minimizing waste production as well as reusing waste through recycling or recovering. This required changes to the waste collection, diversion and disposal systems. This could be done through some new approaches: command and control strategies, economic and institutional policies as well as education and monitoring, as described below. (1) Command and control strategies Command and control refer to direct regulations or activities by legislation to set a standard and guideline for all to follow. Examples of these regulations include federal, provincial and municipal laws and policies regarding waste disposal and diversion such as laws for banning specific items and wastes from landfilling and pollution control regulations. Under the Constitution Act, 1867, environmental matters and issues are assigned to federal and provincial levels of government. The federal government is involved with the regulations and management of toxic substances (and prescribed nonhazardous waste destined for final disposal) regulated under the Canadian Environmental Protection Act (CEPA), waste management on federal lands and in federal facilities, nuclear wastes (regulated under the Atomic Energy Control Act) and the transboundary transportation of hazardous wastes which requires the supplier to provide the WHMIS labels and Safety Data Sheets (SDS) for sale or importation [28, 30]. Provincial governments play an important role in waste management. They have specific rules and regulations to govern the disposal and recycling of wastes. Most of the regulations regarding hazardous waste management are assigned to the provincial governments and the definitions for hazardous waste and regulations for their use and disposal might vary from one province to another [28]. In Ontario, there are several key laws and regulations regarding waste and recycling. These include R.R.O. 1990, Regulation 347- General Waste Regulation, which provides regulations on garbage, municipal waste, asbestos, hazardous waste and liquid industrial wastes; the Environmental Protection Act (EPA) of Ontario, which provides regulations for protection and conservation of the natural environment; Waste Audit and Reduction Work Plan Regulation; Packaging Audits and Packaging Reduction Work Plans; Waste Management Projects; IC&I Source Separation Programs; the Waste

14

1 Wastes Generation, Characterization, Management Strategies …

Diversion Act, which promotes the waste reduction, reuse and recycling; the Environmental Assessment Act, which provides strategies for protection, conservation and wise management of the environment; and the Planning Act, which provides policies for sustainable economic development in a healthy natural environment [31]. Municipalities can also form their own by-laws and policies as mentioned in Municipal Government Act through three primary approaches: passing by-laws for waste disposal, passing regulations through local health authorities and developing zoning by-laws for waste disposal and handling facilities [28]. For example, the city of London, Ontario, by-laws for waste management include: Municipal Waste and Resource Materials Collection By-law-WM-12, which regulates the collection of municipal waste and resource materials in the City of London; Waste Discharge Bylaw-WM-16, which regulates the discharge of wastes into the public sewage works and of hauled liquid waste; and Wastewater and Stormwater By-law-WM-28, which is for wastewater and stormwater drainage system [32]. In addition, Extended Producer Responsibility (EPR) has been adopted as an effective command and control strategy for waste management [28]. The EPR refers to a strategy in which the producer’s physical and financial responsibility for the treatment or disposal of product is extended to the post-consumer stage of a product’s life cycle. It is designed to provide incentives to prevent waste at the source, improve the environmentally friendly designs for the product, and support the recycling and materials management goals. The intention of EPR is to shift the public sector responsibility for waste to the brand owners, first importers and manufacturers [7, 28]. In Canada, both EPR and “product stewardship” programs are used to manage products at their end-of-life. Product stewardship programs assign responsibilities to provincial/territorial or municipal governments and use legislated governmental fees or public funds as the funding base. The Canadian Council of Ministers of the Environment (CCME) has developed a Canada-wide action plan for EPR to support the move toward greater producer responsibility, including work towards transforming “product stewardship” initiatives into full EPR programs [33]. (2) Economic and institutional policies Economic and institutional policies in the form of employing incentives, taxes and providing investments for emerging technologies can influence waste management and recycling behavior [37]. Government can introduce policies to encourage waste minimization and recycling by providing policy-based incentives to the supplyside, demand-side and both demand and supply sides. The best policy is a balance between practicality, affordability, and political and social acceptability. Examples of the policy-based incentives to encourage improved recycling include employing taxes on waste disposal and developing programs for deposit-refund (for example, for beverage containers), charges for single-use items and packaging, electronic stewardship program, etc. [28]. (3) Education and monitoring Education and awareness are essential to changing the traditional view about waste and influencing their lifestyle choices to support resource recovery. Examples include

1.3 Waste Management Strategies

15

supporting participation in resource recovery and waste reduction through communities, waste characterization studies and waste audits, school programs and training [28, 34]. Admittedly, educational studies take time to penetrate people’s lives and alter their behavior related to waste production and management, so that incentivebased programs such as considering a reward for participation could be beneficial to achieve short-term success in people’s participation and perception toward waste management plans [28].

1.4 Health and Environmental Impacts of Wastes and Waste Management Waste that is improperly managed, untreated, or inadequately disposed may result in serious environmental and health problems. Waste management and minimizing its impact on the environment (such as land, air and water), the plants, animals and human health is a challenging task for many countries [2].

1.4.1 Impacts of Waste on Human Health and the Environment Organic waste: Organic waste can affect human health by the growth of microbial pathogens and the production of GHG and contributing to climate change. The direct handling of organic solid waste can result in various infectious and chronic diseases in waste workers [35]. Hazardous waste: Exposure to hazardous waste can cause both acute and chronic health problems such as chemical poisoning, cancer, respiratory conditions and heart disease. Some of the chemical ingredients found in solvents, paints and varnishes might result in dizziness, headache and stomach discomfort. Chemicals such as xylene may cause unconsciousness and death at high levels of exposure [35, 36]. Agricultural/industrial waste: Waste from agriculture and industries can have chemical and radioactive hazards. Pesticides and fertilizers, contaminated water, soil erosion and sedimentation, livestock waste, pests and weeds are the main sources of pollution and can contaminate the water body or groundwater source. The contaminants can impair vital body organs and the immune system, destroy the nervous system and spread the parasites and bacteria through drinking water contributing to disease and fatality [35]. Hospital and medical waste: Hospital and medical waste can cause severe illness and even death. AIDS, cholera, typhoid, Hepatitis B and SARS are some of the serious illnesses that can be caused by improperly managed hospital waste. Other types of infectious disease include skin disease/allergy, diarrhea, dysentery, tuberculosis and malaria [35].

16

1 Wastes Generation, Characterization, Management Strategies …

Heavy metals: Heavy metals are metallic elements that have a high atomic weight and a density of at least five times greater than that of water [37]. High amounts of heavy metals can be introduced to the environment through multiple industrial, agriculture, domestic and medical applications, as well as usage of wastes or fertilizers. Chromium (Cr), arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb) are the main types of heavy metals that are toxic to human health, and they are widely distributed in the environment [38]. For instance, Cr (VI) in drinking water has been found to cause cancer in the oral cavity and small intestine. It can also cause irritation or ulcers in the stomach and intestines, and toxicity in the liver. In the U.S., the OSHA Permissible Exposure Limit (PEL) for airborne exposures to Cr (VI) is 5 µg/m3 (0.005 mg/m3 ). The above five elements have a strong affinity for sulfur; in the human body they usually bind, via thiol groups (–SH), to enzymes responsible for controlling the speed of metabolic reactions. The resulting sulfur-metal bonds inhibit the proper functioning of the enzymes involved; human health deteriorates, sometimes fatally [38]. Cr (VI) and As are carcinogens; Cd causes a degenerative bone disease; and Hg and Pb damage the central nervous system. Lead is the most prevalent heavy metal contaminant [39]. Other heavy metals noted for their potentially hazardous nature, usually as toxic environmental pollutants, include manganese (central nervous system damage), nickel (carcinogens), copper/zinc/silver (endocrine disruption, congenital disorders, or general toxic effects in fish, plants, birds or other aquatic organisms). As such, the WHO has a strict drinking water standard to give the maximum permissible level, as shown in Table 1.5. Air pollutants: Air pollutants include sulfur oxides (SOx ), nitrogen oxides (NOx ), Volatile Organic Compounds (VOC), carbon monoxide (CO), particular matter including heavy metals, ammonia (NH3 ) and polyaromatic hydrocarbons (PAH) [2, 13]. The total air pollutant emissions by a source in Canada in 2015 are summarized in Table 1.6. As shown in the Table, the total annual emissions of air pollutants in Canada are 1.1 million tonnes (Mt) SOx , 1.9 Mt NOx , 1.9 Mt VOC, 5.6 Mt CO, 0.49 Table 1.5 WHO drinking water standard. Regenerated with permission from [40]

Metal ions

Maximum permissible level in drinking water (mg/L or ppm)

Cu(II)

2

Zn (II)

3

Ni (II)

0.02

Cd (II)

0.003

Pb (II)

0.01

Fe (III)

No guideline

As (III)

0.01

Ag (I)

No guideline

Cr (VI)

0.05

Hg (II)

0.001

Mn (II)

0.5

0.02

19,000 5500

17

23,000 7200

Dust

Fires

Total

15

0.02

3.7

6.4

Agriculture

52

43

Paints and Solvents

52

Transportation and Mobile Equipment

Incineration and Waste

110

Manufacturing

7.3

1300

19

Electric Power Generation (Utilities)

13

96

190

17

Oil and Gas Industry

3200

240

Ore and Minerals Industries

16,000

10

1000

0.012

2.7

180

320

40

19

3.8

10

33

4.9

82

4.0

1000

74

150

470

82

NOx (kt)

14

290

98

310

110

1.6

690

13

0.04 1100

2.0 1900

5.9 1900

5600

130

0.0004

18

1200

0.90

3000

140

39

540

520

490

0.018

4.3

3.1

450

7.2

12

0.38

2.2

1.2

Cd (kg)

Hg (kg)

PAH (kg) 220

74

8.3

86

130

800

0.14

50

24

100,000

0.32

120

11

6

2900

1400 690

1100 550

76

180

580

130

160,000 7800 4400 110,000

560

3200

64

27,000

5800

1400

510

120,000 5400 1400 5400

VOC CO (kt) NH3 (kt) Pb (kg) (kt)

50%), nitrogen oxide (NO) cause adverse effects • Industrial sectors and nitrogen dioxide on respiratory systems (NO2 ) of humans and animals, • Formed in all types of • Can cause damage to vegetation, and combustions in air via materials and can the pathways of contribute to thermal-NOx , fuel-NOx acidification of aquatic and prompt-NOx • NO2 can dissolve in and terrestrial water vapor in the air or ecosystems rain to form nitric acid • NO2 and VOCs can form ground-level ozone and PM25

VOCs

• Are carbon-containing gases and vapors, excluding CO2 . CO, CH4 and CFCs, that participate in atmospheric photochemical reactions]

• Have direct toxic • Natural resources effects on human health (92%) such as carcinogenesis • Industrial and transportation sectors or neurotoxicity • Can combine with nitrogen oxides (NOx ) in photochemical reactions in the atmosphere and form ground-level ozone (a major component of smog) and PM25 (continued)

1.4 Health and Environmental Impacts of Wastes and Waste Management

19

Table 1.7 (continued) Air pollutant Characteristics

Environment impacts

Sources

CO

• Is a colorless, odourless • Can enter the • Transportation and tasteless gas, bloodstream through produced from the the lungs and form incomplete combustion carboxyhemoglobin, of organic matters inhibiting the blood’s capacity to carry oxygen to the organs and tissues • Can lead to impairing exercise capacity, affect visual perception, manual dexterity, learning functions, and ability to perform complex tasks • Can cause death of human being at excessive exposure (100 ppm or greater)

PM

• Is a complex mixture of • They have the ability to • Unpaved roads, extremely small penetrate deep into the construction, particles and liquid lungs and blood stream agriculture and forest droplets that get into and cause serious fires (96% of TPM) the air health effects such as asthma, bronchitis and emphysema and to various forms of heart disease. They can also adversely affect vegetation and structures and contribute to regional haze

NH3

• Is a colorless gas with a • Has the ability to • Livestock waste characteristic pungent combine with sulphates management and smell noticeable at and nitrates in the fertilizer production concentrations above atmosphere to form (90%) 50 ppm, PM2.5 • Is primarily produced in agriculture sector

(1) Sulfur oxides (SOx ) SOx , consisting mainly of sulfur dioxide (SO2 ), is formed from the sulfur in raw materials such as coal, oil and metal-containing ores during combustion and refining processes. SO2 dissolves in water vapor in air to form acids, and interacts with other gases and particles in the air to form sulfates and other products that can be harmful to people and environment. SO2 in its untransformed state has negative effects on

20

1 Wastes Generation, Characterization, Management Strategies …

the respiratory systems of humans and animals, and causes damage to vegetation. The acid form of SO2 can contribute to the acidification of aquatic and terrestrial ecosystems and the sulfate particles could contribute to the formation and emission of fine particulate matter (PM25 ) by reacting with ammonia in the atmosphere. PM25 has adverse effects on human health and the environment and can lead to visibility impairment and regional haze [13]. 60–70% of the total SOx emissions were produced from the ore/mineral and oil/gas industries, and 20–30% were from the electric power generation, as shown previously in Table 1.7 [2, 41]. (2) Nitrogen oxides (NOx ) NOx are a group of gases consisting mainly of nitrogen oxide (NO) and nitrogen dioxide (NO2 ), formed in all types of combustions in air via the pathways of thermalNOx , fuel-NOx and prompt-NOx . NO2 can dissolve in water vapor in the air or rain, forming nitric acid and other products. Nitrogen oxides and nitric acid can cause adverse effects on respiratory systems of humans and animals, can cause damage to vegetation, and materials and contribute to the acidification of aquatic and terrestrial ecosystems. NO2 and volatile organic compounds can form ground-level ozone and PM25 . Between 1985 and 2009, transportation was the highest emitter of nitrogen oxides, responsible for more than half of the NOx emissions, while other industrial sectors were the second largest source of NOx emission (Table 1.7) [2,41]. (3) Volatile organic compounds (VOCs). VOCs are carbon-containing gases and vapors, excluding carbon dioxide, carbon monoxide, methane and chlorofluorocarbons, that participate in atmospheric photochemical reactions [2,13]. Most VOCs have direct toxic effects on human health such as carcinogenesis or neurotoxicity. The more reactive VOCs can combine with nitrogen oxides (NOx ) in photochemical reactions in the atmosphere and form ground-level ozone (which is a major component of smog) and PM25 [13]. In 2009, more than 92% of the VOC emissions were from natural resources, while industrial and transportation sectors were responsible for the second and third highest emissions [2]. (4) Carbon monoxide (CO) CO is a colorless, odorless and tasteless gas, produced from the incomplete combustion of organic matters. It can enter the bloodstream through the lungs and form carboxyhemoglobin, a compound that inhibits the blood’s capacity to carry oxygen to the organs and tissues. It can lead to impairing exercise capacity, affect visual perception, manual dexterity, learning functions, and ability to perform complex tasks, and cause the death of human being at excessive exposure [13]. On average, exposures at 100 ppm or greater is dangerous to human health [42]. Commonly the major source of carbon monoxide emissions is transportation [2, 41]. (5) Particulate matter (PM) PM is a complex mixture of extremely small particles and liquid droplets that get into the air. Total Particulate Matter (TPM) refers to the particles with a diameter of

1.4 Health and Environmental Impacts of Wastes and Waste Management

21

less than 100 m. PM10 and PM2.5 are defined as particles with diameters less than 10 and 2.5 m diameter, respectively. They have the ability to penetrate deep into the lungs and bloodstream and cause serious health effects such as asthma, bronchitis and emphysema and various forms of heart disease. They can also adversely affect vegetation and structures and contribute to regional haze [13]. In 2009, open dust sources such as unpaved roads, construction, agriculture and forest fires contributed to 96% of TPM, 93% of PM10 and 72% of PM2.5 . Industrial sources and residential fuel combustion were the second largest emitters of PM10 and PM2.5 , respectively [2]. (6) Ammonia (NH3 ) NH3 has long been recognized as an important air pollutant contributing to harmful effects on human health and the environment. It is a colorless gas with a characteristic pungent smell noticeable at concentrations above 50 ppm. Ammonia is primarily produced in the agriculture sector as a result of livestock waste management and fertilizer production, accounting for almost 90% of the total NH3 emission in Canada (Table 1.7) [41]. It has the ability to combine with sulfates and nitrates in the atmosphere to form PM2.5 [13]. (7) GHG and short-Live climate pollutants: GHG are gases that trap the heat in the atmosphere, resulting in global warming and climate change. The primary GHG in the earth’s atmosphere are water vapor, carbon dioxide (CO2 ), nitrous oxide (N2 O) and ozone. Short-lived climate pollutants (SLCPs) are gases and particles that contribute to global warming but have a shorter atmospheric lifetime compared to GHGs. They include black carbon, methane (CH4 ) and fluorinated gases such as hydrofluorocarbons, perfluorocarbons, sulfur hexafluoride, and nitrogen trifluoride [13]. According to the International Energy Agency (IEA) [43], global CO2 emissions rose to a historic high of 32.5 billion tonnes in 2017 due to higher energy demand and the slowing of energy efficiency improvements. Fossil fuels combustion for energy is the dominating source of CO2 , contributing to about 80% of the global CO2 emission, while the MSW management (incineration, landfills, etc.) also generates a significant amount of CO2 , accounting for almost 5% of total global CO2 emissions [5]. The highest GHG emissions in Canada between the years of 1990 and 2016 were 745 megatonnes (Mt) of CO2 equivalent in 2007. The total GHG emissions in 2016 were 704 Mt of CO2 equivalent. The decrease in emissions is primarily owing to reduced emissions from the electricity generation sector [13]. CO2 is by far the most common GHG emitted and the energy production and stationary combustion sources are the largest source of GHG emissions (Fig. 1.7) [2, 44].

22

1 Wastes Generation, Characterization, Management Strategies …

Fig. 1.7 Compositions of Canadian GHG and break down of the emissions in 2018 expressed as carbon dioxide equivalents. Reprinted with permission from Environment and Climate Change Canada [44]

1.4.2 Impacts of Waste Management on the Environment As discussed previously, the collected waste is commonly disposed either by landfilling or thermal treatment (such as incineration) or diverted from incinerators and landfills to recycling or composting [45]. However, landfilling and incineration are usually associated with various health and environmental problems such as surface and groundwater pollution, soil and water contamination by the leachates, and emission of toxic gases (e.g., H2 S, SO2 , dioxins, etc.) and GHG (CO2 and CH4 ). Diversion to recycling or composting or other valorization is thus an environmentally friendly way to deal with waste management.

1.4 Health and Environmental Impacts of Wastes and Waste Management

23

A major problem from improperly managed waste in landfills is the leachate generation that causes a significant threat to the surface- and groundwater and subsequently causing problems for plants and animals living downstream. Leachate generation, as a result of moisture penetration existing in the waste, is a major problem for municipal solid waste landfills. Leachate is a liquid that passes through the landfills, picks up a variety of toxic and pollutant components and can potentially contaminate ground and surface water [2]. The quantity of leachate generation depends on local climate conditions, surface slope of the landfill site, cap material and surface cover materials [46]. Leachate from a landfill mostly contains high levels of acids, organics such as chlorinated compounds, solvents and metals. Table 1.8 presents compositions of landfill leachates in various countries/regions. Table 1.8 Comparison between the compositions of landfill leachates in various countries/regions Parameter Taiwana (mg L−1 )

Hong Kongb

Kuwaitc

Saudi Arabiad

USAe

Germanye

Age (Year)

10–16

11

–

2–3

–

–

pH (−)

7.03–8.50

7.2–8.4

6.9–8.2

5.94–6.32

5.1–6.9

5.7–8.1

EC (dS m−1 )

3.58–14.16 2.5–11.8

1.2–16.9

4.25–6.32

–

–

COD

320–1340

K

198–778

78–416

–

2408–4622

–

–

Na

320–1342

132–743

–

4136–7770

–

–

Ca

47.2–137.5 –

5.6–122

5300–8600

254.1–2300

70–290

Mg

27.8–103

8–26

5.2–268

693–2612

233–410

100–270

Cd