Abstract
The groundwater of several regions in Xinjiang, China, including the Kuitun and the Manas River Basins in the Junggar Basin, is heavily polluted with arsenic. However, the arsenic content of the groundwater of the Karamay area located within the Junggar Basin is relatively low and below the recommended drinking water limit. In our study, we analyze the factors that result in this anomaly. The geological and geochemical characteristics of the water-bearing system in this area were investigated by analyzing water samples, carrying out hydrogeological surveys, and statistical techniques. Since the Carboniferous, the geological development and subsequent structural evolution resulted in a lower arsenic concentration in groundwater of the Karamay region than that of the Kuitun River Basin and the Manasi River Basin. The missing high-energy sedimentary environment in the Middle-Upper Permian and the composition of sediments controlled the characteristics of the multi-layer aquifer in this area. We find that the lack of arsenic sources, neutral and slightly alkaline environment, water injection to extract oil, and the Irtysh River Diversion to Urumqi Project, result in better groundwater quality and lower arsenic pollution in this area.
Geological and Geochemical Characteristics of Low-Arsenic Groundwater in The Karamay Area Between Two High Arsenic Areas of Xinjiang, China
