Spatial distribution, geochemical behaviors and risk assessment of antimony in rivers around the antimony mine of Xikuangshan, Hunan Province, China.

Pollutants derived from antimony (Sb) mining can easily cause pollution of surrounding water bodies. However, qualitative source analysis of river pollution is mostly conducted, and quantitative source analysis is still lacking. A total of 21 water samples were collected to analyze the pollution status of the heavy metal element Sb, explore the Xikuangshan (XKS) area river heavy metals pollution mechanism, undertake quantitative analysis of the sources of pollution, and carry out irrigation water suitability assessment and potential ecological risk assessment. The results showed that, compared with the mining non-affected area, the maximum excess multiple of Sb in surface water and rivers in Hunan XKS area is 411.31. When the river fluid flows through the mining-affected area, the heavy metal element Sb content increases rapidly, and then decreases due to dilution process. Positive matrix factorization (PMF) source analysis showed that the main source of Sb pollution in the rivers is the impact of mining and smelting (83.60%), followed by the role of waste rock leaching (16.40%). After irrigation, 27.78% of the river water had strong ecological risks, and 16.67% had extremely strong ecological risks. This achievement provides a theoretical basis and technical guarantee for protecting and using the local water body of the mining area.