Identification of hydro-geochemical processes in groundwater by using major ion chemistry: a case study

Hydro-geochemistry is important for water disaster controlling as it can be used for either understanding of hydrological evolution or water source discrimination. Groundwater samples from the sandstone aquifer in Xutuan coal mine, northern Anhui Province, China have been collected for major ion chemical analysis to understand the operating mechanism of geochemical processes for variation of groundwater chemistry, which will be useful for improving the understanding of hydro-chemical systems in coal mine. The results suggest that they are medium to slightly (6.8 to 8.64 with an average of 7.61) with high concentration of total dissolved solids (943 and 1362 mg/L with mean of 1171 mg/L)). Most of the groundwater samples are classified as Na- HCO3-Cl and Na-Cl-HCO3 types according to their relative concentrations of cations and anions. Correlation between ion concentrations, as well as principle component analysis imply that dissolution of dolomite, halite, gypsum, silicate weathering and ion exchange are responsible for the chemical variations of the groundwater.