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- Herausgeber: John Wiley & Sons
- Kategorie: Wissenschaft und neue Technologien
- Sprache: Englisch
Eco-Restoration of Mine Land An authoritative introduction to the ecosystem-based approach for restoring land after coal and mineral mining operations. Mining activities, in particular where metal ores have been mined, often leave behind vast areas of dumps and disused mine lands that have become environmental hazards. Soil degradation and poisoning are major environmental concerns in these areas, requiring comprehensive and long-term interventions in order to restore those lands to an ecologically productive state. Eco-Restoration of Mine Land provides a comprehensive overview of ecosystem-based solutions for remediating polluted soil and re-establishing vegetation in disused mine lands, synthesizing cutting-edge research, experiential knowledge, and longstanding best practices to offer a holistic introduction to the science of mine land restoration. Eco-Restoration of Mine Land readers will also find: * A basic introduction to soil contamination, risk assessment, and phytoremediation of mine land * Discussion of carbon sequestration potential of restored mine soils and other environmental benefits of remediated mine land * The use of biological soil quality indicators to assess progress in ecosystem restoration Eco-Restoration of Mine Land is a valuable guide for researchers and advanced students in the environmental and ecological sciences, as well as professionals working in environmental remediation, providing a much-needed survey of this increasingly critical subject.
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Veröffentlichungsjahr: 2022
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Table of Contents
Cover
Title Page
Copyright Page
Foreword
Preface
Acknowledgments
About the Authors
1 Mine Land and its Environmental Impacts
1.1 Introduction
1.2 Environmental Impacts of Mine Land and Ecological Disruption
1.3 Economic Valuation of Impacts on Environment
1.4 Environment Protection and Policy Implication
1.5 Management and Reclamation
1.6 Progressive Reclamation
1.7 Conclusion
References
2 Soil Contamination, Risk Assessment, and Phytoremediation of Mine Land
2.1 Introduction
2.2 Soil Contamination
2.3 Risk Assessment
2.4 Phytoremediation of Mine Land
2.5 Conclusion
References
3 Bio‐Geotechnologies in Mine Land Restoration
3.1 Introduction
3.2 Potential Approaches for Mine Land Restoration
3.3 Insights and Lessons Learned for the Practice of Mine Land Restoration
3.4 Conclusion
References
4 Carbon Sequestration Potential of Restored Coal Mine Soils
4.1 Introduction
4.2 Generation and Management of Mine Waste
4.3 Carbon Sequestration in Reclaimed Mine Soils
4.4 Carbon Fractionation: Importance and Challenges in Coal Mining Areas
4.5 Carbon Indices
4.6 Mine Soil Amendments
4.7 Carbon Sequestration in Revegetated Coal Mine Soils: A Chronosequence Approach
4.8 Conclusion
References
5 Assessing Mine Restoration Success Using Biological Soil Quality Indicators
5.1 Introduction
5.2 Revegetation of Mine Lands
5.3 Reclaimed Mine Soil Quality Indicators
5.4 Development and Use of Soil Quality Index
5.5 Overview
References
6 Ecosystem Services on Restored Mine Land
6.1 Introduction
6.2 Rehabilitated Mine Land
6.3 Ecosystem Services on Rehabilitated Coal Mine Land
6.4 Restored Mine Land and United Nations Sustainable Development Goals
6.5 Important Case Studies of Mine Restoration
6.6 Policy Restructuring for Fusing Circular Economy and Mine Land Restoration
6.7 Conclusion
References
Notes
Index
End User License Agreement
List of Tables
Chapter 1
Table 1.1 Effects of mining activities on environment.
Table 1.2 Toxic pollutants released from mine dumps created by mining and p...
Chapter 2
Table 2.1 Classes of single indices to estimate soil quality.
Table 2.2 Classes of complex indices to study soil quality.
Table 2.3 ERM and ERL values for elements.
Chapter 3
Table 3.1 Different definitions of phytoremediation.
Table 3.2 Plant varieties effective in revegetation of degraded sites.
Table 3.3 Pioneer woody species in site reclamation.
Table 3.4 Some potential plant varieties in aided phytostabilization.
Table 3.5 Fungi and plants used in mine site rehabilitation.
Table 3.6 Different reclamation strategies benefits and drawbacks.
Chapter 4
Table 4.1 Soil organic carbon stock (Mg C ha
−1
) in afforested coal mi...
Table 4.2 Application of conventional and nonconventional soil amendments a...
Chapter 5
Table 5.1 Tree species commonly used for revegetation of post‐mining lands ...
Table 5.2 Tree species commonly used for revegetation of post‐mining lands ...
Table 5.3 Types of grass and shrub species commonly used for revegetation o...
Table 5.4 Soil biological parameters used as an indicator to assess reclaim...
Table 5.5 Status of soil microbial biomass carbon in the coal mine dumps.
Table 5.6 Soil respiration rate in different reclaimed mine soils.
Chapter 6
Table 6.1 Ecosystem services of restored coal mine lands.
List of Illustrations
Chapter 1
Figure 1.1 Impact of mining on environment.
Chapter 2
Figure 2.1 Effects of mining on environment.
Chapter 3
Figure 3.1 Schematic representation of phytoremediation strategies.
Chapter 4
Figure 4.1 Coal production scenario of the (a) world and (b) India since 201...
Figure 4.2 Typical steps of surface mining and reclamation (a) clearing of n...
Figure 4.3 Types of carbon pool in reclaimed mine soil. Organic carbon contr...
Figure 4.4 (a) Soil organic carbon stock (0–60 cm) in restored coal mine soi...
Chapter 5
Figure 5.1 Land degradation and deforestation due to surface mining activiti...
Figure 5.2 A distance view of the grass–legume mixture growing on mine overb...
Figure 5.3 Soil parameters used to evaluate mine soil quality.
Figure 5.4 Major steps of developing a soil quality index (SQI).
Chapter 6
Figure 6.1 Three‐step moto for sustainable restoration of lands.
Figure 6.2 A notional depiction showing possible ways to poverty reduction a...
Figure 6.3 The basics of a circular economy.
Figure 6.4 Circular economy transition.
Guide
Cover Page
Title Page
Copyright Page
Foreword
Preface
Acknowledgments
About the Authors
Table of Contents
Begin Reading
Index
WILEY END USER LICENSE AGREEMENT
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Eco‐Restoration of Mine Land
Vimal Chandra Pandey
Babasaheb Bhimrao Ambedkar University, Lucknow, India
Jitendra Ahirwal
Department of Forestry, Mizoram University, Aizawl, India
Roopali Roychowdhury
Department of Biotechnology, Techno India University, Kolkata, India
Ritu Chaturvedi
Department of Botany, St. John’s College, Agra, India
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Library of Congress Cataloging‐in‐Publication Data applied forHardback ISBN 9781119872252
Cover image: WileyCover design by Courtesy of Vimal Chandra Pandey and Jitendra Ahirwal
Foreword
Environmental degradation by mining is a major concern worldwide. Mining activities have led to the formation of dumps and abandoned mine lands which have negative impacts on the environment immediately and even after several years. Mine lands pose environmental risk due to the presence of moving and transforming heavy metals and metalloids. Several risk assessment methods via calculation of pollution indices have been designed to perform an extensive geochemical assessment to analyze soil quality of mine lands, to carry out ecological and human health risk assessment, to determine the origin of natural or anthropogenic pollutants, and to study the degree of soil degradation. Reversing soil degradation, regaining soil fertility, and remediation of polluted soil are the major challenges and need redressal immediately after mining operations. Revegetation emerges out to be a feasible solution for ecosystem restoration. To overcome this challenge, the book addresses the scope of mine land restoration for achieving the United Nations Sustainable Development Goals.
This book is useful to select specific plant species according to site specificity of the mined land. As this book explores, there are clearly some potential opportunities in mine land restoration. This book provides a concept of ecological restoration of mined land for regaining ecosystem services and raising livelihoods. It is also the intention of this book to enable the reader to become better informed with the mechanisms of plant’s adaptation to adverse conditions prevailing on mine land. General public has become more aware of the importance of preserving the environment and human health through eco‐restoration of mine land. This authored book is well timed and has up to date information that offer a cutting‐edge synthesis of scientific, recent experiential, and established knowledge as a single source on different aspects of mine land restoration.
I congratulate the authors, Dr Vimal Chandra Pandey, Dr Jitendra Ahirwal, Dr Roopali Roychowdhury, and Dr Ritu Chaturvedi, for bringing out this valuable book published by a renowned publisher Wiley. The book consists of six chapters covering various aspects of Eco‐Restoration of Mine Land. I believe this book will be a notable asset for mining industry professionals, eco‐engineers, eco‐planners, researchers, PhD scholars, plant scientists, environmentalists, practitioners, entrepreneurs, policy makers, and other stakeholders alike.
28 June 2022Dr Jan FrouzProfessor and DirectorEnvironmental Centre, Charles University, Prague, Czech Republic
Preface
Mining is an integral part of the national economy. The excavation of land resources is essential to fulfilling energy demands but causes multitudinous effects on the environment. The global mining market is expected to grow at a rate of 12% per annum which can further imperil ecological processes and functions. Asia Pacific is the largest mining market accounting for 70% of the global mining activities followed by North America and Western Europe. The mining of minerals, coal, and metals such as iron, copper, zinc, lead, and nickel are dominant in mining sectors. However, coal, anthracite, and lignite mining alone contributed to more than half of the mining markets. Correspondingly, land degradation due to mining activities is increasing at an alarming rate. Thus, repairing these degraded lands is essential to reinstate ecosystems and becomes a part of sustainable mining strategies.
Surface mining leads to changes in geological settings and removal of vegetation cover, alters soil properties, and degrades large pieces of land. Mining is site specific, and land degradation due to mining is highly dependent on the stripping ratio – ratio of ore extracted to overburden materials. These activities are also responsible for relocating indigenous populations that affect their livelihood and alter land use patterns in many parts of the world. Mining is therefore responsible for environmental, social, and economic transformation. Land degradation and environmental pollution caused by mining activities have attracted a great deal of scientific and political attention. Several restoration efforts have been taken to restore the mine‐degraded lands, and most of them are based on reforestation and afforestation. These revegetation activities improve soils, biogeochemical cycles, and biodiversity; reduce toxicity; and maintain the overall aesthetic values of the post‐mining lands.
Eco‐Restoration of Mine Land is focused on a continuum of restoration activities namely environmental, social, and economic in terms of ecological restoration that is primarily based on post‐mining lands. This textbook is a compact and precise collection of relevant literature and scientific practices designed to combat land degradation and biodiversity losses, restore soil fertility, and phytomanagement of mine waste. In general, ecological restoration is the process of assisting the recovery of any degraded, damaged, and destroyed ecosystem to bring it back to its original conditions. This attempts to reinstate species composition, ecosystem productivity, and structure prior to disturbance. This textbook comprises different chapters that describe basic theory of restoration science and numerous facts and findings related to the ecological restoration of mined lands. Mining and its overall impact on the environment, soil contamination, and its phytomanagement, different bio‐geotechnologies employed to improve ecosystem structure and functions such as soil fertility and carbons sequestration, and how to assess the impact of restoration practices by selective indicator parameters are the major focus of this book. Besides, how a restoration of mine degraded lands provides ecosystem services such as supporting, regulatory, provisioning, and cultural are described in brief. How mine restoration is helpful in achieving the United Nations sustainable development goals and its link to the circular economy are also discussed.
Eco‐Restoration of Mine Land addresses the basis theory and practices of ecological restoration of mine degraded land. This book is a collection of specific literature that comprehensively deals with the impact of mining on the environment and human health, techniques of mine restoration, ecosystem services including carbon sequestration provided through mine restoration, metal toxicity reduction by plants, soil fertility management, and sustainable mining practices. This book is designed for a restoration practitioner working in different mining areas. This book will be helpful to students belonging to different fields of applied ecology and environmental sciences such as restoration ecology, earth sciences, ecotoxicology, environmental engineering, microbiology, and environmental pollution. This book will also serve as a reference guide for policy planners, land managers, and restoration ecologists to manage post‐mining lands. Finally, we believe this book will integrate environmental, biological, engineering, ecological, social, and economic aspects of ecosystem management and thereby assist readers to develop multidisciplinary approaches to restoring mine degraded lands.
Vimal Chandra PandeyBabasaheb Bhimrao Ambedkar University, Lucknow, IndiaJitendra AhirwalMizoram University, Aizawl, IndiaRoopali RoychowdhuryTechno India University, Kolkata, IndiaRitu ChaturvediSt. John’s College, Agra, India
Acknowledgments
We sincerely thank Rituparna Bose (editor), Mandy Collison (managing editor), and Frank Weinreich (publisher) from Wiley for their excellent support, guidance, and coordination during the production of this fascinating project. We thank all the reviewers for their careful and insightful review of the book chapters. The authors are highly thankful to Professor Jan Frouz, Director, Environmental Centre, Charles University, Prague, Czech Republic for writing the foreword at short notice. We would like to thank our respective families for their endless support and encouragement.
About the Authors
Dr Vimal Chandra Pandey featured in the world’s top 2% scientists curated by Stanford University, United States. Dr Pandey is a leading researcher in the field of environmental engineering, particularly phytomanagement of polluted sites. His research focuses mainly on the remediation and management of degraded lands, including heavy metal‐polluted lands and post‐industrial lands polluted with fly ash, red mud, mine spoil, and others, to regain ecosystem services and support a bio‐based economy with phytoproducts through affordable green technology such as phytoremediation. Dr Pandey's research interests also lie in exploring industrial crop‐based phytoremediation to attain bioeconomy security and restoration, adaptive phytoremediation practices, phytoremediation‐based biofortification, carbon sequestration in waste dumpsites, climate resilient phytoremediation, fostering bioremediation for utilizing polluted lands and attaining UN Sustainable Development Goals. His phytoremediation work has led to the extension of phytoremediation beyond its traditional application. He is now engaged to explore profitable phytoremediation with least risk, low input, and minimum care. Dr Pandey worked as a CSIR‐Pool Scientist and DS Kothari Postdoctoral Fellow at Babasaheb Bhimrao Ambedkar University, Lucknow; a consultant at the Council of Science and Technology, Uttar Pradesh; and DST‐Young Scientist at CSIR‐National Botanical Research Institute, Lucknow. He is the recipient of a number of awards/honors/fellowships and is a member of the National Academy of Sciences India. Dr Pandey serves as a subject expert and panel member for the evaluation of research and professional activities in India and abroad for fostering nature sustainability. He has published over 100 scientific articles/book chapters in peer‐reviewed journals/books. Dr Pandey is also the author and editor of 10 books published by Elsevier and CRC Press, with several more forthcoming. He is an associate editor of Land Degradation and Development (Wiley); an editor of Restoration Ecology (Wiley); an associate editor of Environment, Development and Sustainability (Springer); an associate editor of Ecological Processes (Springer Nature); an academic editor of PLOS ONE (PLOS); an advisory board member of Ambio (Springer); an editorial board member of Environmental Management (Springer), Discover Sustainability (Springer Nature), and Bulletin of Environmental Contamination and Toxicology (Springer). He also works/ worked as guest editor for many reputed journals.
Dr Jitendra Ahirwal is a postdoctoral researcher in the Department of Forestry, Mizoram University, Aizawl, India. Dr Ahirwal received his PhD on the topic “Reclaimed mine soil quality and carbon sequestration potential of mining induced land use changes in a dry tropical climate” from Indian Institute of Technology (Indian School of Mines), Dhanbad, India. His main research areas are ecological restoration, carbon sequestration, land use change, CO2 flux, and climate change. He has published over 30 research papers in reputed journals and several book chapters with leading international Publishers. Dr Ahirwal received the Presidential International Fellowship Initiative (PIFI) award for postdoctoral research from the Chinese Academy of Sciences at CAS‐Institute of Botany, Beijing, China. Dr Ahirwal serves as an active reviewer for several reputed international journals and a member of Society for Ecological Restoration (SER), USA.
Dr Roopali Roychowdhury is currently engaged in bioremediation and phytoremediation of polluted sites as well as in deciphering the mechanisms of enhanced bioremediation. She obtained her PhD in environmental biotechnology from the Department of Biotechnology, Techno India University, West Bengal, India. She has published 22 research papers in reputed international and national journals and 3 book chapters.
Dr Ritu Chaturvedi recently received her PhD degree on the topic “Risk Assessment and Phytoremediation Efficiency of AMF‐assisted Vegetable Plants under Heavy Metal Stress” working in the Department of Botany, St. John’s College, Agra, Uttar Pradesh, India. Her early research was focused on bioremediation of heavy metal through fungi and EDTA. She is also working on plant‐based bioremediation or phytoremediation. Till now she has published 6 research papers in reputed international journals, 1 review article and 6 book chapters with Springer and Elsevier Publishers. She also serves as a potential reviewer for several reputed national and international journals.
1Mine Land and its Environmental Impacts
Abstract
Exploration of mineral resources and mining is indispensable for the economic development of any nation, but its ruinous impact on environment is inevitable. Though mining sector significantly contributes to gross domestic product (GDP) and employment of workforce in any nation, it causes irreversible harm to the environment. This sector is known to afflict environment by causing disturbance in air quality, pollution of water bodies, depletion of soil fertility, desertification, deforestation, endangerment of wildlife, etc. Therefore, any mining project must necessarily include a mine reclamation closure plan in order to exploit resources judiciously, not at the cost of environment. This chapter highlights the environmental impacts of mining and presents the solutions that can be adopted with mining to protect the environment.
Keywords:Mining; pollution; ecological disruption; acid mine drainage; reclamation;
CONTENTS
1.1 Introduction
1.2 Environmental Impacts of Mine Land and Ecological Disruption
1.2.1 Soil Erosion
1.2.2 Loss of Soil Fertility and Desertification
1.2.3 Loss of Biodiversity
1.2.4 Air Quality
1.2.5 Emission of Greenhouse Gas and Climate Change
1.2.6 Water Quality Deterioration
1.2.7 Sedimentation in Streams and Rivers
1.2.8 Groundwater Regime
1.2.9 Noise Pollution
1.2.10 Human Health
1.2.11 Formation of Mine Dumps
1.2.12 Visual Impacts
1.2.13 Social Impacts
1.2.14 Other Issues
1.3 Economic Valuation of Impacts on Environment
1.4 Environment Protection and Policy Implication
1.5 Management and Reclamation
1.6 Progressive Reclamation
1.7 Conclusion
References
1.1 Introduction
Mineral wealth accounts to more than 70% of resources required worldwide (Pashkevich 2017). Mining activities pertain to extraction of nonrenewable resources (fuels, metallic, nonmetallic, and minor minerals) from a resource‐rich ore. Mining resources are pivotal to promote economic growth and expansion of any nation. In India, mining industry contributes around 10–11% to gross domestic product (GDP) of total industrial sector. Around 80% of mining in India pertains to coal, and the rest is related to remaining minerals. India is the largest producer of mica blocks and mica splitting and produces ~60% of world’s mica. As of 2019, India was fourth largest producer of iron ore and chromium; fifth largest producer of bauxite, zinc, and graphite; seventh largest producer of manganese, lead, and sulfur; and eleventh largest producer of titanium and uranium worldwide (Corporate Catalyst India [CCI] 2010). Post announcement of New Mineral Policy in 1993, mining sector in India was opened to foreign direct investment (FDI), but the investment remained low due to restrictions in obtaining approvals (Mehta 2002). Since then the FDI policy in the mining sector has been gradually liberalized, for example, by introducing automatic approval route, and has remained successful to attract FDI. However, there are certain challenges that need to be addressed in mining sector such as upgrading and adapting to eco‐friendly technologies, curtailing environmental degradation and post‐mine rehabilitation, and addressing social issues dealing with displacement and marginalization of native dwellers and its economic consequences. In India, premier organizations such as Geological Survey of India (GSI) and Mineral Exploration Corporation Ltd (MECL) carry out survey and mineral exploration activities, while Indian Bureau of Mines (IBM) is engaged in regulation and conservation. Though IBM updates the inventory of mineral deposits every five years, immense research and exploration still need to be carried as India has diverse mineral deposits yet to be discovered (Kumar 2019).
Environmental damage and mining scale do have an unequivocal relationship (Li et al. 2016). Around 90–95% of extracted mineral resources are lost as wastes, which result in the formation of technogenic dumps (Pashkevich and Petrova 2015). It is well documented that both active and abandoned mine sites affect terrestrial (soil fertility and erosion), aquatic (water quality and biota), and atmospheric (air quality) components of ecosystem adversely (Favas et al. 2018). It becomes alarming when active mine sites or abandoned mine lands are categorized as devastated landscape, where the natural tendency of auto regeneration is lost and only human intervention can lead to reclamation. Large‐scale mining projects involve more technology, generate more wastes, and run for longer time, i.e. exposing environment to more damaging effects. Moreover, the topography and climate of a mine site also govern the level of environmental damage that is bound to occur. The mobilization of heavy metals (such as Cd, Cu, Hg, Mn, Ni, Pb, and Zn) and metalloids (As and Sb) during mining through extraction from ores and processing releases these toxic elements into the environment. Precipitation, temperature, wind flow, humidity, and other factors strongly determine the extent of diffusion of pollutants to surrounding environment. The atmosphere plays key roles in dispersion of air pollutants, whereas precipitation influences spread of water pollutants (Li et al. 2016).
Different mining projects vary in their plan according to the physical and chemical properties of the ore being mined. A proposed mining project begins with an explorative phase whereby the extent and value of the ore are evaluated via surveys, field studies, test drillings, and excavations and concludes with a post‐closure phase. Each of these phases can be held responsible for a range of outcomes on environmental health. Even if the findings of explorative phase render the mining project unsuitable, the area is already de‐vegetated and profoundly disturbed in the name of exploration. Whereas if the exploration proves that the ore is of sufficient grade and the mining project is economical, further developments (not without adverse impacts) are made including clearing of vast areas and construction of access roads. Thereafter, the active mining phase, i.e. extraction and beneficiation of target metal from its ore, begins. Metallic ores are generally buried under huge amount of waste rock or overburden, which needs to be removed by any of the processes depending on the type of ore. Strip ratio, i.e. the ratio between the amount of overburden generated and the mineral ore, is generally more than one or much higher. The overburden may contain toxic elements which either get deposited on‐site or dumped into a landfill. If the ore is buried very deep in the ground, it is accessed through open‐pit mining which results in high volume of overburden removal. Environmentally, it is the most destructive mining process especially in tropical forests, as it involves clearing of vegetated areas by cutting or burning native vegetation. Moreover, the constant increase in demand for minerals can be met from open cast mines ultimately leading to massive deforestation. But it is lower in cost and suitable for lower‐grade ore mining (Environmental Law Alliance Worldwide 2010).
In another technique, placer mining is used if the metal is associated with stream sediments or floodplains, e.g. gold. Since it takes place within a streambed, it discharges high load of sediments which adversely affect surface water to great extent. An environmentally less destructive way to access ore is through underground mining as it minimally affects landscape, but it is costlier and poses safety risks as compared to open‐pit mining. It can affect hydrogeological conditions and may induce earthquakes (Li et al. 2016).
After successful removal of overburden, the ore is extracted using heavy machinery and transported to processing units for beneficiation. Beneficiation includes physical and/or chemical processes to separate metals from nonmetallic components of ore. Even high‐grade ores often contain toxic metal(loid)s such as lead, cadmium, and arsenic. Techniques such as milling, magnetic separation, solvent extraction, and leaching are employed for this purpose. However, these processes generate waste in the form of dumps, tailings, and leach materials. Exploitation of different types of minerals results in divergent environmental impacts. Combustible organic materials generate solid wastes and emit toxic gases. Mining of metallic ores leads to heavy metal(loid) pollution (Li et al. 2016). Beneficiation of gold and silver ores requires spraying of cyanide solution over finely milled ore to dissolve target metals and collected thereafter. Likewise, leaching of copper requires sulfuric acid and releases high‐volume waste in the form of tailings which need to be addressed for proper disposal in order to prevent mobilization and release of toxic compounds into the environment. The involvement of cyanide calls for special attention for its fate and impact on environment, since it disrupts oxygen metabolism and causes acute toxicity at all trophic levels even at low concentrations and for over long periods (González‐Valoys et al. 2022).
Post‐mining, the ultimate aim of any mining project should be to reclaim the mining site almost to its pre‐mining condition. And hence, mining closure plan must be designed scientifically justifying actions and measures adopted to prevent pollution and the insurance of funds for reclamation.
1.2 Environmental Impacts of Mine Land and Ecological Disruption
Minerals obtained from mine lands are limited and nonrenewable in nature. Due to their applications in various industries, reckless exploitation of these natural resources often leads to environmental imbalances. Mining activities are known to impact forest ecology, wildlife, local climate, and water balance of the area. The Sustainable Development Networking Programme, India states how mining activities in a region affect natural resources in an area (Table 1.1). Figure 1.1 illustrates the pathway of receptivity of pollutants from mine sites to plants, animals, and humans.
Table 1.1 Effects of mining activities on environment.
Air
Water
Dust emission due to blasting operations in surface mines
Release of GHGs such as methane and carbon dioxide from coal mines
Release of heavy metal(loid)s and SO
x
during smelting operations
Mining operations require large amounts of water which is sourced from underground or nearby water bodies
SO
x
compounds released into air react with water and form sulfuric acid which pollutes groundwater or water bodies
Land
Life
Blasting activities and creation of sink holes affect land integrity
Mining leads to deforestation and loss of biodiversity
Mining leads to soil erosion and contamination, affecting soil quality and fertility adversely
Underground mining activities can be hazardous due to poor ventilation and visibility
Rock falls and explosions in mining sites are hazardous for all forms of life
Exposure to dust and radiations poses health risks to workers
Mining activities amend the landscape completely to a hostile state and are responsible for multiplex environmental issues. The magnitude of ecological impacts is not just limited to aesthetics and visual features but extend from soil erosion to pollution of air and water, habitat destruction to loss of species, resulting in overall perturbance to environment. These disruptions reduce the range of biological activities in proximity of mine site leading to decline in function and stability of the ecosystem (Li et al. 2016). Mining activities not only lead to pollution but also modify the landscape significantly, and hence disrupting the micro‐climate of that region.
1.2.1 Soil Erosion
Clearing vegetation and excavations are the first phases of any mining project. Open‐pit sites, overburden heaps, tailing piles, dump leaches, etc. contribute chemical pollutants and are prime sources of sediment loading. The eroded sediment as a part of surface runoff often gets deposited in nearby floodplains or loads into surrounding water bodies. The minerals present in contaminated sediments may lead to reduction in pH of soil as well as water, affecting the physicochemical properties thereby. Lower soil pH renders the soil unsuitable for vegetation and also facilitates mobilization of heavy metals, enabling them leaching into subsoil or groundwater. Increase in particulate matter in water bodies due to surface runoff may prove toxic for the fishes and affect the complete food chain (Geelani et al. 2013; Pashkevich 2017). Erosion followed by sedimentation is responsible for the accumulation of sediments and rock dust in water bodies and floodplains, causing reduction of storage capacity in surface water and modification of aquatic habitat (Barve and Muduli 2011).
Figure 1.1 Impact of mining on environment.
1.2.2 Loss of Soil Fertility and Desertification
Mining activities habitually reform the even and tranquil landscape by continuously uncovering mining material. Since a large area is involved under mining, huge quantities of earthen material are exposed on sites especially in case of hard rock mining (Geelani et al. 2013). Mining activities transform the nature of these mine lands and make them less fertile by removing the topsoil layer, leaving them more prone to soil hazards (Buta et al. 2019). Stripping off topsoil and exposing the subsoil layer to heavy equipment and machinery subject them to damage. Operations requiring high temperature render the soil dehydrated, making it dense and compact. Fire used to clear off vegetation also affects minerals present in soil, altering structure and composition. Burning primarily reduces soil’s productivity by destroying humus and nutrients like nitrogen and phosphorous. Such soil with altered texture is easy to break and less fertile (Li et al. 2016). Mining wastes and effluents from dumps are highly acidic and their release results in altered pH of soil, ultimately leading to loss of habitat for various microbes and plants (Barve and Muduli 2011). It becomes apparent in the form of reduced crop yield and survival.
1.2.3 Loss of Biodiversity
The very first phase of mining, i.e. exploration, involves clearing of vegetation and removal of topsoil besides releasing pollutants into the soil in upcoming phases. Disturbances caused in the natural habitat due to air, water, and noise pollution lead to displacement of fauna. As we know that habitat loss is the primary cause of species extinction, the extent to which mining activities affect biodiversity can be understood. Habitat fragmentation as a consequence of mining has been shown to affect amphibian diversity and distribution in Western Ghats, India (Krishnamurthy 2003). As plant and animal communities are interdependent and depend on common natural resources which get polluted by mining, entire communities get affected. The massive adverse effect of mining on abiotic factors which is responsible for the change in natural biota can be depicted by low Simpson’s diversity index (SDI) in mining areas. Mining activities perturb homeostasis of environmental factors which leads to disturbed ecosystem (Basavaraja and Kumar 2020). Mining activities affect abiotic components of environment directly, which in turn perturb the distribution of biotic components, i.e. natives might be replaced by exotics as a consequence of unplanned mining and rehabilitation. Invasion is of, by and large, occurrence in areas disturbed due to land transformation and anthropogenic activities. Several invasive exotic plant species have been identified in areas undergoing reclamation, which are able to disrupt the growth of other plants either by covering the canopy and competing for sunlight or by possessing deep root systems and competing for nutrient absorption (Yusuf and Arisoesilaningsih 2017). Invasive exotic species often invade recent reclaimed mine sites, if they lie in close proximity to older reclaimed mine lands. Such plants not only compromise revegetation success and ecosystem succession but also are a threat to the existence of native and desirable species (Zipper et al. 2019).
Additionally, increase in concentration of SO2 in air due to operations such as blasting and combustion of fossil fuels is deleterious to sensitive species. Alteration in species composition leads to reduction in primary productivity and perturbs trophic relationships, hence possesses extensive effects for both floral and faunal communities.
1.2.4 Air Quality
Mining operations namely, excavation, blasting, and erosion mobilize and disperse large amounts of particulate matter into air, which is the primary pollutant of concern. Operation of heavy machinery and vehicles generates large amounts of dust which flows due to high wind velocity. Combustion of fuels by transportation facilities and equipments such as generators and smelting furnace contributes to gaseous emissions (containing volatile organic compounds [VOCs], SOx, NOx, CO, and volatile heavy metals) and leads to deterioration of air quality. Air polluted with particulate matter has reduced oxygen saturation and is capable of causing discomfort in living organisms (DeMeo et al. 2004). Polluted air also carries more SO2 which can inhibit photosynthesis by disrupting photosynthesis mechanism. SO2 promotes stomatal opening in plants and leads to excessive water loss due to transpiration. It is detrimental to both quality and quantity of plant yield. Another indirect consequence of SO2 pollution is occurrence of acid rain that is capable of leaching out nutrients from plant canopy and soil (Varshney et al. 1979).
Mercury, generally present in gold ore, gets vaporized during processing operations and gets released in atmosphere. Inhalation of iron and manganese mine dusts for extended durations can lead to siderosis and manganosis, which are occupational diseases causing damage to respiratory system. Pollutants upon entering the environment undergo physical and chemical changes and ultimately impact life forms adversely (Basavaraja and Kumar 2020).
1.2.5 Emission of Greenhouse Gas and Climate Change
Heavy machinery, power generation, and transportation facilities employed during mining operation are known to release massive amounts of gases such as CH4, CO2, NOx, which are detrimental to ozone layer and known as greenhouse gases (GHGs). Some of these gases such as CO2 and NOx are responsible for acid rain and also act as secondary pollutants (Li et al. 2016). Increase in the emission of GHGs due to anthropogenic activities is primarily responsible for increased greenhouse effect, i.e. global warming. Melting of glaciers, rising sea level, desertification, etc., are the alarming consequences of global warming which have threatened the existence of life on Earth. Depletion of ozone layer will lead to more UV rays entering atmosphere and reaching Earth’s surface, causing magnitude of impact on plants, animals, and humans (Basavaraja and Kumar 2020).
Moreover, mining projects need to be evaluated for their carbon impact as they potentially modify global carbon budget. Life cycle assessment methodology can be used to estimate environmental impacts and has been applied to different mineral processes (Franks et al. 2010). Tropical forests act as lungs for the planet by absorbing CO2 and releasing O2, but this equilibrium gets hampered when a proposed mining project demands destruction of forests.
1.2.6 Water Quality Deterioration
Water is the most crucially affected resource during mining operations and is called “mining’s most common victim.” Mining by its tendency consumes, diverts, and pollutes water resources, and its impacts can be broadly classified in four major types: acid mine drainage (AMD) or acid rock drainage (ARD), processing chemicals discharge, heavy metal pollution and leaching, and erosion and sedimentation (Emmanuel et al. 2018). Large quantities of wastewater containing heavy metals, reagents, acids, suspended solids, sewage, etc., are generated in due course of mining. Huge amount, complex composition, wide range, and long duration are the features of wastewater emission that make it worth concern (Li et al. 2016).
Mining below the water table, i.e. underground mines and open pits, provide a direct conduit to aquifers. Infiltration of wastewater through overburden piles also potentially deteriorates groundwater (Thakur et al. 2013). The presence of hydraulic connections between surface water and groundwater is also a major source of contamination. During beneficiation, the chemicals used for leaching process dissolve metals and other toxic contaminants and form a highly acidic, metal‐rich solution. This is the most potential source of water pollution as it leads to acid drainage and contaminant leaching in metal‐mined areas. Since pH is the key factor in determining the leachability of heavy metals, a decrease in pH favors their mobility (Król et al. 2020). Leaching and blasting also result in raised concentrations of cyanide and nitrogen compounds in waters at mine sites. AMD or ARD occurs upon oxidation of metal sulfides and possesses long‐term devastating impact on water bodies resulting in pH < 4, which challenges survival of flora and fauna. Natural weathering process also brings about oxidation of mineral metal sulfides leading to the formation of sulfuric acid, but that is a slow process. Mining and beneficiation expose sulfide‐containing overburden to air and water and magnify the rate of chemical reactions leading to AMD (Geelani et al. 2013). It can also dissolve and discharge heavy metals into water bodies which are toxic, nondegradable, and persistent contaminants of environment having carcinogenic effects on living organisms as a result of bio‐magnification. The effects of the presence of heavy metals in water bodies may be immediate (toxicity resulting in death) to sublethal, i.e. affecting growth and development. It is practically impossible to stop AMD after mining has begun for an acid‐generating mine and to permit such project is least sustainable.
The mobility of pollutants from all the abovementioned sources is magnified in events of rainfall or snowfall, as these bring more water to mine site and contribute to runoff quantity, ultimately getting discharged and polluting water bodies (Geelani et al. 2013).
During the framing of mining project, the question that needs to be addressed is whether the water quality in mining‐affected region will be fit for human consumption in future or whether it will be adequate to support native aquatic and terrestrial organisms. If not, then a treatment and recycle strategy must be designed based on the requirement. Water polluted due to mining may contain suspended solids, be highly saline, or acidic and/or contain special pollutants such as fluoride, heavy metals, and radioactive elements. Several purification techniques are, however, available and can be implemented for the treatment of mine water such as “high‐efficiency clarification plus gravity valveless filter” for water containing suspended solids, reverse osmosis for highly saline mine water, limestone trench method or sulfate reduction bacteria reactor for acid mine water, ion exchange method for fluoride containing water and precipitation method for heavy metals (Wang et al. 2021). Treating and reusing mine water will not only lead to reduction in pollution due to discharge of wastewater but also avoid water shortage in future.
1.2.7 Sedimentation in Streams and Rivers
Both surface water and underground water are exploited during different phases of mining. In case of open‐pit mining, a pit that extends up to below groundwater table is created and water is pumped out for mining to take place. This leads to the formation of pit lakes, and groundwater supply is turned off. On the other hand, placer mining pollutes surface waters by discharging large amounts of sediments into it. Sediment‐laden surface runoff generally arises as sheet flow and gets collected in rills or gullies before being finally deposited in water bodies or floodplains (Geelani et al. 2013).
Additionally, disposal of tailings in streams and rivers is one of the worst practices done during mining operations. Mining waste deposits contain high amounts of potentially toxic elements and affect smaller stream sediments along with main streams close to their confluence. Toxic elements are then transported across long distances along major watercourse, thus resulting in regional pollution (Miler et al. 2022). A water management plan must be an indispensable part of any mining project as any meagre design may lead to high levels of dissolved as well as suspended solids in water resources nearby mine sites.
1.2.8 Groundwater Regime
The reaction of groundwater system to hydrological stresses and anthropogenic intervention is groundwater regime which is known to govern surface hydrology, soil texture, and vegetation (Basavaraja and Kumar 2020). Deep mine excavations under the groundwater table lower the groundwater level in adjacent areas. The water present is pulled by the action of gravity into the empty space and may lead to dewatering of wells, irrevocable loss of soil moisture and proves detrimental to revegetation during reclamation. Both quality and quantity of groundwater are affected adversely if the backfill material is significantly different from parent material or if a mine is situated in groundwater recharge zone.
1.2.9 Noise Pollution
Almost all the processes during mining involve use of heavy machinery during excavation, blasting, drilling, and transportation and are significant sources of noise pollution. Blasting operations are also the cause of vibrations experienced in areas near mine sites. Operation of heavy machinery and vehicles usually during overburden handling creates massive intensity of noise.
The World Health Organization (WHO) classifies noise above 65 dB as noise pollution. Noise above 75 dB is considered to be harmful and painful if it exceeds 120 dB. Noise level in mine sites often exceeds 90–120 dB, which is far above permissible limits. This may affect both physical and mental health such as damage hearing mechanism, severely affect memory, cause dizziness, insomnia, and fatigue, leading to disturbance among humans nearby and also affects wildlife distribution (Li et al. 2016).
1.2.10 Human Health
“Red Alert” – a documentary made by Saki (Non‐governmental Organization) – highlights health problems faced by mine workers and shows that lung infections and heart problems are of high prevalence in mining areas (Basavaraja and Kumar 2020). Pollutants released from mine sites may enter humans from oral, dermal, or inhalation routes. The concentration of pollutants present in environment and its intake by organisms are taken into account to estimate the health risk. The amount of food ingested or the amount of air inhaled is useful for the calculation of daily consumption values, which is then compared with permissible limits (Pashkevich 2017). For substances like heavy metals, determining transfer effect (i.e. ratio of concentration in plants and soil) is important as plants are the basic component of food chain. Such pollutants tend to bio‐accumulate while moving ahead in trophic levels. Heavy metals such as cadmium, zinc, and thallium are readily absorbed by the roots of plants, whereas arsenic, chromium, and mercury tend to settle on above ground parts. Various indices namely, estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI), and target cancer risk (TCR) have been stated by U.S. Environmental Protection Agency (US EPA) which are calculated using heavy metal concentration of edible portion of plants, reference dose (i.e. permissible limit), exposure duration, exposure frequency, average life span, and body weight of target population. They are used to estimate and highlight the risks associated with dietary exposure to potentially toxic elements over lifetime (Antoine et al. 2017).
1.2.11 Formation of Mine Dumps
The disposal of overburden leads to the formation of mine dumps, which transform the natural system to a technogenic landscape. Mine dump formation adversely affects the nature of underlying rocks along with modifying hydrological and hydrogeological regimes of surrounding area (Pashkevich and Petrova 2016). Additionally, it leads to the reduction of agricultural area, pollution and erosion of soil, and degradation of atmosphere in vicinity (Alekseenko and Pashkevich 2016). The volume and chemical properties of the wastes determine the magnitude of hazards associated with the dump site. Besides, the mobility and migration ability of wastes along with the degree of resistance provided by the environment are also pivotal in determining toxicity. Such anthropogenic alteration of soil and water composition in addition to air quality of an area modifies it to technogenic geochemical fluxes and halos (Pashkevich 2017).
On the basis of their genesis, mine dumps can be categorized into the following:
Piled dumps – consisting of structurally damaged soils, solid and mineral wastes of industrial origin, and solid wastes of domestic origin.
Hydraulic‐filled dumps – consisting of hydraulically stacked soils, household and mineral wastes (tailings and sludges).
Technogenic sediments – consisting of solid mineral wastes redeposited through air and water (precipitated particles, technogenic sediments, and artificial soils). Sand, fly ash, salts, chemicals, and other inorganic compounds are examples of mineral pollutants, whereas materials of plant or animal origin along with resins, phenols, and alcohols constitute organic pollutants. Pathogenic microbes present in sewage water tending to enter water bodies are biological contaminants.
Table 1.2 Toxic pollutants released from mine dumps created by mining and processing industries.
Mine dump/industry
Pollutants released
Ferrous resources
Heavy metal(loid)s such as arsenic, cadmium, lead, mercury, chromium, nickel, zinc, and vanadium; acids and alkalis; and organic contaminants such as mineral oils
Non‐ferrous resources
Heavy metal(loid)s such as arsenic, antimony, beryllium, cadmium, chromium, copper, lead, mercury, nickel, selenium, thallium, vanadium, and zinc; aromatic organic compounds such as cresol; and cyanides, fluorides, acids, and alkalis
Coal
Heavy metal(loid)s such as arsenic, chromium, lead, and zinc; organic compounds such as cresol, mineral oils, benzene, phenols, anthracene, toluene, xylene, and naphthalene; fluorides, acids, and bases
Petroleum
Heavy metal(loid)s such as arsenic, copper, chromium, lead, selenium, vanadium, and zinc; organic compounds such as anthracene, benzene, gasoline, mineral oil, naphthalene, phenol, and tar oil; acids and alkalis
The composition of mine dumps and range of pollutants they release vary with different mining industries. A list of potentially toxic pollutants has been enumerated in Table 1.2 (Pashkevich 2017).
Another factor that determines the degree of toxicity due to a mine dump is the migration of contaminants, which is controlled by a range of internal as well as external factors. External migration factors include temperature and pressure for atmosphere and lithosphere (Martínez‐Sánchez et al. 2012); physicochemical conditions such as pH and Eh and parameters such as chemical bonds and gravitational properties are key determinants for hydrosphere (Chalov et al. 2016). Factors such as locomotion ability are crucial for biotic pollutants such as pathogenic bacteria. In case of atmospheric migration, pollutants migrate in a suspended state or in gaseous form and affect the receptors, i.e. plants, animals, and humans directly. In case of migration through water, both contaminated surface and groundwater merge into water bodies and reach receptors. But soils are generally considered to be indirect and intermediate mode of dissemination that particularly acts through food chains (soil–plants/animals–humans) (Pérez‐Sirvent et al. 2016). A peculiar feature soils possess is their ability to accumulate, filter, neutralize, and decompose certain pollutants. Moreover, soils are naturally rich in microbes, support vegetation, and hence undergo remediation naturally.
1.2.12 Visual Impacts
Visual impacts are related to aesthetic aspects and rehabilitation of a mined site. Nearly all stages of mining from clearing of vegetation followed by removal of overburden and dumping deteriorate the aesthetics of a site. Rain splashes on overburden dumps lead to sheet, reel, or full erosion which further damages the aesthetic value of the site (Geelani et al. 2013). Mine dumps are known to affect terrain topography, geological structure, soil cover, hydrography, climate, and vegetation (Pashkevich 2017). Besides, disturbance in water drainage, water logging, soil erosion, destruction of vegetation, and dust blow are some direct impacts of mine dumps on human population residing nearby. The reduction in visual landscape value is characterized by declining landscape value. It is a parameter that cannot be measured quantitatively and is of subjective value (Geelani et al. 2013).
1.2.13 Social Impacts
While discussing the adverse effects of mining activities, its impact on environment is taken much into consideration; what is often taken for granted is the dislocation of forest dwellers and their lost home, land, and livelihood. The social impacts of mining are contentious. Though it can lead to creation of roads, employment of labor, development of inaccessible areas, and generation of wealth, the benefits are unevenly shared. Any commercial activity must ensure that the basic needs of dwellers are fulfilled and rights are not violated. This means they should get right to use land, get livelihood, and have access to clean water and safe place to dwell. They must be compensated fairly for the damages caused by mining to them. As per human laws, all citizens are equal and hence the marginal groups need to be protected. But in mining areas, the ones who are rich and powerful exploit the natural resources ruthlessly leading to depletion. The consequences are then faced by marginal dwellers whose livelihood relies on biomass‐related products collected from immediate environment. Upon disappearance of forests and siltation of water bodies, their biomass‐based subsistence economy is massively affected (Basavaraja and Kumar 2020). Even the common property resources such as community forests, village ponds, pastures, and wastelands, which must be available to all inhabitants, can be expected to be transferred under private ownership due to scarcity of resources as a result of rampant mining (Guha 2006).
1.2.14 Other Issues
Mining in India is disrespectful for human rights violation and adverse impacts on environment. Second, appropriate assessment of resources is not complete yet; several areas still remain unexplored in terms of mineral presence. Since the distribution of minerals is uneven and fluctuates substantially from one area to another, absence of a genuinely evaluated data is a challenging issue.
Besides the abovementioned environmental problems, safety of mine workers and residents nearby also requires attention. Physical stability of mines is a crucial long‐term concern keeping repercussions of slope failure in mind whereby toxic contaminants release and find a direct pathway to receptors (Mehta 2002). A pre‐mining design with overburden disposal plan is a prerequisite of any mining project. An underestimation of the amount of overburden composing the slope may lead to failure. Besides slope failure, landslides in hilly terrains during mining operations are also not uncommon.
1.3 Economic Valuation of Impacts on Environment
Environment pays a huge cost for every mining project. These outcomes namely erosion, pollution, fertility loss, safety issues, and health risks should be estimated and evaluated with the production cost. It is necessary to accentuate the costs associated with the disposal of overburden which needs to be both physically and biologically stabilized. Assessment of abandonment cost of the mine inclusive of closure activities namely wire fencing surrounding work site, dismantling and demolition of structures, cleaning of site and machinery, remediation and reclamation, post‐environmental monitoring and supervision charges, power cost, and miscellaneous costs needs to be done in order to ascertain economical valuation.
Moreover, conservation of resources and their administration should be done scientifically, usage of resources should be judicious, wastage should be minimal in extraction process, substitutes of the minerals being widely used should be sought out, logical recycling of used metals and scraps should be followed, and discovery of new deposits needs to be carried out in order to justify the costs associated with mining process.
