An Overview of Soil Pollution and Remediation Strategies in Coal Mining Regions

Abstract

Coal remains a very important source of energy for the global economy. Surface and underground coal mining are the two major methods of coal extraction, and both have benefits and drawbacks. Surface coal mining can have a variety of environmental impacts including ecosystem losses, landscape alteration, soil destruction, and changes to surface and groundwater quality and quantity. In addition, toxic compounds such as heavy metals, radioactive elements, polycyclic aromatic hydrocarbons (PAHs), and other organic contaminants are released in the environment, ultimately affecting the health of ecosystems and the general population. Underground mining has large impacts on underground water supplies and water quality, but generally has less visual surface impacts such as leaving waste and tailings on the surface and subsidence problems. In response to the concern about these environmental issues, many strategies have been developed by scientists and practitioners to minimize land degradation and soil pollution due to mining. Reclamation laws passed in numerous countries during the past 50 years have instituted practices to reduce the impacts of soil pollution including burying toxic materials, saving and replacing topsoil, and vegetating the land surface. While modern mining practices have decreased the environmental impacts, many sites are inadequately reclaimed and present long-lasting soil pollution problems. The current review summarizes progress in comprehending (1) coal mining impacts on soil pollution, (2) the potential risks of soil pollution associated with coal mining, and (3) different types of strategies for remediating these contaminated soils. Research and prospective directions of soil pollution in coal mining regions include refinements in assessing pollutant levels, the use of biochars and other amendments, phytoremediation of contaminated soils, and the release of toxic elements such as mercury and thallium.

A review of soil pollution by potentially toxic elements and remediation strategies in copper mining areas in Iran

“…Acid mine drainage (AMD) occurs when pyrite and other sulfate metals (such as tailing pits and dams open exposed cuts, and ore and waste-rock piles) oxidize due to exposure to air and microbial activity in mining areas. Numerous studies have demonstrated the critical role that water plays in the distribution and mobility of PTEs in the vicinity of mining sites (Han et al 2017;Liao et al 2016;Rouhani et al 2023b). High levels of PTEs and sulfate, as well as low pH values, are features associated with AMD.…”

Source and Migration Pathways of Heavy Metals in Soils from an Iron Mine in Baotou City, China

“…The exploitation of mineral resources generates various types of waste, which often contains high levels of heavy metals. The improper treatment of accumulation and discharge can lead to serious pollution of the water and soils in the mining area [6][7][8][9]. At present, land area contaminated by mining in China exceeds 2 million hectares and is increasing at a rate of 33,000-47,000 hectares per year [10].…”

Seasonal changes of soil microbiota and its association with environmental factors in coal mining subsidence area

“…As a special type of wetland, new wetland in coal mining subsidence area is obviously different from natural wetland and other types of constructed wetland in terms of formation process and human disturbance degree. Studies on coal mining subsidence land at home and abroad are more focused on subsidence land reclamation technology, subsidence land ecological restoration technology, and subsidence land restoration and management technology (Li et al 2022 ; Rouhani et al 2023 ; Bi et al 2018 ). There are relatively few studies on the evolution law of nascent wetland ecosystems in coal mining subsidence areas, which focus on the change of soil fertility, biochemical properties of soil, and microbial communities in subsidence areas (Ma et al 2019 ; Sun et al 2023 ; Fang et al 2023 ).…”