Impact of coal mining disturbances on uranium migration in groundwater with prevention and remediation technologies

Coal mining disturbance can elevate uranium concentrations in groundwater by 3-6 orders of magnitude above background levels, often exceeding the World Health Organization drinking water guideline (30 μg/L) by a factor of more than 1000. This study systematically reveals the synergistic mechanisms of cascading coupling among physical fracture fields (a 4- to 22-fold increase in hydraulic conductivity forming preferential flow pathways), chemical forcing (oxidative dissolution by acid mine drainage with pH < 4 followed by neutral carbonate complexation), and microbial regulation (dissimilatory sulfate/iron reduction and phosphate mineralization) that drive uranium mobilization and immobilization. A bimodal risk pattern of “proximal acidic oxidation-driven dissolution and distal neutral carbonate complexation-driven dispersion” is elucidated. A closed-loop source tracing system integrating baseline identification, pathway verification, causal matching, and exclusion analysis is developed to accurately discriminate anthropogenic mining disturbance from natural uranium anomalies. Based on this mechanistic understanding, an integrated collaborative governance framework of “source prevention and control-process interruption-end remediation” is proposed. This framework provides a theoretical basis and a technical pathway for the precise identification and long-term remediation of radioactive groundwater contamination in coal mining areas.