Statistical and isotopic analysis of sources and evolution of groundwater

Identified the hydrochemical and the sulfur cycle process in subsidence area of Pingyu mining area using multi-isotopes combined with hydrochemistry methods

“…The first components affecting groundwater hydrochemistry are Cl − , NO 3 − , Ca 2+ , Mg 2+ , SO 4 2− and Na + , with the respective loadings of 0.872, 0.850, 0.793, 0.723, 0.688 and 0.520. In general, Ca 2+ and Mg 2+ in groundwater mainly generated by the dissolution of silicates and carbonates in aquifers, while Cl − and NO 3 − mostly comes from human activities (Jacob et al 2023;Liu et al 2020). In summary, the main factors affecting SO 4 2− and hydrochemical types in the studied area were water-rock interaction and human production activities.…”

“…Therefore, when the mEq ratio of (Na + +K + )/Cl − is over 1, it is mainly the dissolution of rock salt that occurs in groundwater; when the ratio is below 1, it can be deduced that the dissolution of silicate also takes place. When it comes to Ca 2+ , Mg 2+ , HCO 3 − and SO 4 2− in groundwater, they are mainly derived from the weathering and dissolution of carbonates such as calcites and dolomites and evaporites such as gypsum (Jacob et al 2023), and thus, when the (Ca 2+ +Mg 2+ )/(HCO 3 − +SO 4 2− ) mEq ratio is over 1, Ca 2+ and Mg 2+ in solution mainly come from the dissolution of carbonate. ; if the ratio is below 1, it indicates that Ca 2+ and Mg 2+ are generated by the dissolution of silicates and evaporites.…”