HYDROCHEMISTRY OF OF GROUNDWATER FROM THE LOOSE LAYER AQUIFER: QUALITY AND CONTROLLING FACTOR ANALYSIS

Groundwater in the loose layer aquifer system is important for the water supply and safety of mining in the coal mines. In this study, a total of fifty-two groundwater samples from the Zhuxianzhuang coalmine in northern Anhui Province, China have been collected, and their major ion concentrations have been measured for evaluating the quality of the water and identifying the main mechanisms controlling the chemical variations. The results suggest that the groundwater from the loose layer aquifer system have pH values in the permissible range of World Health Organization (WHO), whereas they should be treated before drinking according to their high contents of total dissolved solids (TDS). The groundwater samples were classified to be Na-SO4 and Na-Cl types, which related to the hydrological condition of the water. The Water Quality Index (WQI) values of the groundwater were 79 to 188 (mean = 149), suggesting that these groundwater samples are poor for drinking when considering about only their major ion concentrations. However, they can be used for irrigation according to their sodium absorption ratio (SAR) and residual sodium carbonate (RSC) values. Moreover, Gibbs diagrams, relationships between major ions and factor analysis suggest that water rock interaction and evaporation (related to discharging) are the main mechanisms controlling groundwater chemistry.