Hydrogeochemical Processes and Quality Assessment of Groundwater in Sulin Mining Area, Northern Anhui Province, China

In mining areas, coal production, agriculture, and drinking use had increased the demand for fresh groundwater. It was essential to obtain a deeper understanding of the groundwater evolution processes and the water quality for domestic and irrigation uses in Sulin mining area in the northern Anhui province, China. Thirty-two shallow groundwater (SG), eighteen mid-layer groundwater (MG), and three surface water (SW) samples were analyzed for conventional hydrogeochemical and hydrogen oxygen stable isotopes. Geochemical characterization showed that the predominant ions in both SG and MG were Na+ and HCO3- . In addition, they probably originated from atmospheric precipitation. The ionic milliequivalent ratios demonstrated that the shallow and mid-layer groundwater circulation was mainly controlled by natural processes: rock weathering, silicates dissolution, and ion exchange were the major hydrogeochemical processes occurring. Besides, total dissolved solids, SO42-, Cl-, Na+, and NO3- of SG and total dissolved solids, SO42-, Cl-, Na+ and F- of MG were higher than the values of Chinese Standards for Drinking Water Quality and the guidelines of the World Health Organization for drinking water quality. According to some indices and the classification diagrams of water quality, most SG was suitable for irrigation, while MG with high sodium and salinity hazards was not suitable for irrigation.