Using Isotopic and Hydrochemical Indicators to Identify Sources of Sulfate in Karst Groundwater of the Niangziguan Spring Field, China

Karst groundwater in the Niangziguan spring fields is main source to supply domestic and industrial water demands Yangquan City, China. However, safety of this region has recently suffered from deteriorating quality levels. Therefore, identifying pollution sources causes crucial for maintaining a reliable supply. In study, systematic sample collection karst was implemented identify hydrochemical characteristics through comprehensive analyses hydrochemistry (piper diagram, ion ratios,) stable isotopes (S H-O). The results show that categorized as SO4·HCO3-Ca·Mg, HCO3·SO4-Ca·Mg, SO4-Ca types. K+, Cl-, Na+ are mainly sourced urban sewage coal mine drainage. addition, SO42? supplied by dissolution gypsum oxidation FeS2 coal-bearing strata. It noteworthy that, based on H-O S isotopes, 75% contaminated acidic mines at different degrees. field, proportions derived were 60.6% (N50, Chengxi spring), 30.3% (N51, Wulong 26.0% (N52, Four springs mixed with water). Acid drainage directly recharges pollutes faults or abandoned boreholes, discharges rivers, indirectly river infiltration carbonate exposed areas. rapid increase sulfate acid mines.