MAJOR ION CHEMISTRY OF GROUNDWATER FROM LIMESTONE AQUIFER IN TAOYUAN COAL MINE, NORTHERN ANHUI PROVINCE, CHINA

摘要

More and more attention has been paid towards the deep-buried groundwater in China with the increasing demand for water shortage. Major ion levels of ground-water samples from a limestone aquifer in Taoyuan coal mine, northern Anhui Province - China, with up to 700-m depth, have been studied for evaluating their quality and the operating mechanisms. The results suggest that they are medium to slightly alkaline but cannot be used for drinking directly because of their high concentration of total dissolved solids as well as ion concentrations (e.g. Na, Ca, Cl and SO_4) relative to the water standards of World Health Organization, and most of them are classified as Ca-Mg-Na-SO_4-Cl type. The correlation between ion concentrations (e.g. Na-Cl, Ca-Mg), as well as some indices (e.g. chloro-alkaline) imply that chemical composition of the groundwater in the aquifer is controlled by multiple processes, including silicate weathering (e.g. feldspar), mineral dissolution (e.g. calcite and gypsum), and ion exchange (e.g. Na-Ca).