Analysis of metal ion content and sources in water bodies of a typical mining area in China.

Against the backdrop of growing global energy demand and transboundary environmental pollution, heavy metal pollution from coal mining poses a significant environmental risk, necessitating strengthened governance to ensure water security and ecological sustainability. The concentration, spatial pattern and pollution sources of Li, Fe, Mn, Pb, Cr, Cd, Cu and As in the water body of Shenmu City, Shaanxi Province, which is a typical energy base in China, were systematically analyzed. Using high-density sampling (299 water samples), combined with GIS spatial interpolation, correlation analysis, and principal component analysis (PCA), the sources and ecological risks of heavy metals were identified. Results revealed that the maximum concentrations of Fe, Mn, Cr, and As in few samples exceeded the limits set by the Surface Water Environmental Quality Standard by 5.5, 9.3, 10.3, and 10.3 times, respectively. The average potential ecological risk index (RI) was 44.54, indicating an overall light ecological hazard level. Even, the ecological risk coefficients of Cr, Cd, and As at certain points reached a strong hazard level. Correlation and source analysis indicated that Fe, Mn, and Pb mainly originate from coal mining and industrial activities, while the abnormal enrichment of Li and As is relative to intensive human activity. The study recommends establishing a dynamic monitoring network for highly polluted areas and formulating differentiated prevention and control strategies to balance energy development with ecological protection.