Mobilization of fluoride in sediments at high fluoride area enhanced by microorganisms

Abstract

As one of the most widely distributed element in nature, fluorineis essential for human body health. Microbes play a key role in the biogeochemical cycle of various elements in natural environment. This study focus on the mobilization of fluorine from sediment mediated by microorganism activities, using samples from Yuncheng Basin, Shanxi Province, an area with high fluorine-content groundwater. Our study suggest that fluoride content in sediments range between 206.2-781.0 mg/kg with feldspar, mica, calcite, chlorite and amphibole as the major fluoride bearing minerals. The fluorine concentration in the culturesolution showed a good consistency with the growth curve of microorganisms.The fluorine concentration increased rapidly at the early stage of culture, then gradually eased, and showed a downward trend after 14 days.Among them, clay type sediments release more fluoride than sand type sediments.These results indicate that the metabolic activities of the native microorganisms can significantly promote the release of fluorine from sediments. It is also observed that the release characteristics of fluorine is lithology dependent.The research of this paper will be helpful for the full understand of the cycle of fluorine in natural environment.

Keywords

• sediment
• fluorine
• mobilization
• microorganism
• high fluoride groundwater