Contamination Characteristics and Source Identification of Groundwater in Xishan Coal Mining Area of Taiyuan Based on Hydrochemistry and Sulfur–Oxygen Isotopes

Xishan mining area in Taiyuan is a typical coal industry cluster with variety of coal-related industrial sites such as mines, power plants and coking plants, which seriously pollute the native ecological environment. Study hydrochemical characteristics pollution sources groundwater can contribute to protection remediation regional resources. In this study, we collected surface water samples from measured analyzed sulfur–oxygen isotopes. Results showed that 64.7% study exceeded sulfate standard due influence industry, some karst up 2000 mg/L. runoff discharge groundwater, proportion anthropogenic input SO42− increased, led type gradually changing HCO3-Ca·Mg (recharge area) SO4-Ca·Mg (discharge area). isotope tests indicated δ34SSO4 δ18OSO4 values were −10.01~24.42‰ −4.90~12.40‰, respectively, close dissolved end sulfide minerals, indicating their mainly came oxidation pyrite. Sulfate parsed using IsoSource model. Calculated results revealed pore mostly originated pyrite oxidation, recharge was influenced by atmosphere precipitation, while areas significantly affected accounting for 90% groundwater. Comparing 1989, 2016 2022, found 2022 decreased significantly, expansion area. This highlights agglomerations, requires urgent restoration.