Background Mining activities in polymetallic sulfide mines significantly disrupt regional hydrogeochemical equilibrium, leading to the formation of acid mine drainage (AMD). Consequently, severe pollution of aquatic environments occurs, posing a threat to regional water resource security. To lay the foundation for the prevention and control of AMD-induced pollution, it is necessary to investigate the formation and evolution mechanisms of AMD and establish a low-cost, sustainable risk management and control mode.
Methods Based on field sampling and literature research, this study made statistics of the hydrochemical characteristics of AMD from different polymetallic sulfide mining areas across China and elucidated the processes driving the formation of AMD under the combined influence of hydrodynamic, hydrochemical, and microbial fields. Furthermore, in combination with three major challenges in the prevention and control of AMD-induced pollution, this study proposed pathways for reverse hydrogeochemical control.
Results and Discussion Statistical analysis reveals significant variations in the hydrochemical characteristics of AMD from different polymetallic sulfide mining areas across China. Specifically, samples with total dissolved solids (TDS) and \mathrmSO_4^2- - concentrations exceeding the thresholds for Class III water quality specified in the Standard for Groundwater Quality (GB/T 14848-2017) accounted for 78% and 76%, respectively. Accordingly, this study developed a risk assessment system consisting of preliminary, general, and detailed surveys, as well as risk assessment. Furthermore, it determined the limited treatment objective of low-cost, sustainable risk management focusing on environmental control and established the drainage-blocking-treatment-management integrated risk control mode. Following the hierarchical prevention and control principle comprising treatment, control, and prevention strategies for high, medium, and low risks, respectively, the proposed mode adopts measures including priority given to drainage and blocking, blocking-treatment integration, end treatment, and comprehensive management. This mode provides a novel philosophy for low-cost, sustainable prevention and control of AMD-induced pollution.
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