The distribution and formation mechanism of the fluorine in shallow groundwater of Huaibei plain in Anhui province

Fluoride is an important kind of essential elements in groundwater in HuaiBei plain in Anhui province, but excessive fluorine can cause endemic fluorine disease for human such as dental fluorine. In the north-central area of the area,according to the survey, the fluorine from groundwater is more than the standards of drinking water. From northwest to southeast, fluorine content of shallow groundwater in Huaibei plains decrease gradually, and content of fluorine exceeds standard in some areas. Fluorine-containing mineral constantly dissolving is the main reason for causing fluorine ion concentration enrichment in the shallow groundwater. The climate and runoff conditions in Huaibei plain are important external factors for the concentration of fluoride. However, deposit environment is alos the interior factor. The complex hydrochemical condition makes fluoride to be more dissolved or more undissolved. However, the alkaline conditions and the low hardness conditions of the groundwater are in favor of fluoride dissolved.