Fate of Potentially Toxic Elements Derived from Coal Mining in Soil

Coal mining is crucial to satisfying energy demands. However, mining activities create structural and functional changes and release potentially toxic elements (PTEs). Interaction between PTEs and soil physicochemical properties is bidirectional. Therefore, modelling interactions and predicting PTEs is critical for mitigating the consequences of mining activities on soil. The current study is being conducted in Jharkhand state, India, in active mining, abandoned mining, and non-mining locations, to determine soil physicochemical and metallic characteristics. Statistical analysis, including chemometric analysis and multiple linear regression (MLR), was used to investigate the impacts of bidirectional interactions of soil parameters on PTEs. Metals such as Co, Cr, Pb, and Ti have been identified as PTEs. Chemometric study found that PTEs in mining sites are the result of mining activities, but PTEs in non-mining and abandoned mine sites are geological in origin. During the active mining period, mining alters the soil profile and raises PTE concentrations above critical thresholds. The MLR models applied to PTEs of non-mining and active mining sites had R2 values ranging from 88.80% to 99.97%, indicating that a well-defined soil profile allows us to forecast PTEs with high accuracy. In non-mining areas, the PTE concentration is substantially within the critical limits. However, coal mining alters the soil profile and releases PTEs into the earth by breaking down the soil metal complex. The loosened soil contains PTEs in the form of ions or water-dissolved particles. The disturbed soil profile of an abandoned mine makes PTE prediction difficult (R2 prediction as low as 23.43%). Leaching, runoff water, evaporative loss, and phytoremediation processes all help to wash PTEs out of soil over time. Once the soil begins to consolidate into a stable soil profile, the necessary metals, which are more reactive than PTEs, dissociate and bind to the soil complexes restoring the soil health.