高氟孔隙地下水地球化学成因:以山西东山调水工程区为例

Geochemical Genesis of High-Fluoride Groundwater:A Case Study in the Import Region of the Dongshan Water Transfer Project,Shanxi Province

分析了山西东山调水工程调入区高氟地下水的区域分布规律,并对高氟水形成机制进行了深入研究,发现研究区高氟水的主要水化学特征为HCO-3和Na+浓度高、pH值高,且多为HCO3-Na型水。认为该区高氟水形成的主导性地球化学过程包括含氟矿物溶解、地下水中OH-与氟代羟基云母矿物的离子交换等。另外,排泄区的蒸发浓缩过程和含氟工业废水排放也是研究区部分地区出现高氟水的重要因素。

The distribution of high-fluoride groundwaters in the import region of the Dongshan water transfer project was investigated.Regional hydrogeochemical survey indicates that the high-fluoride groundwaters are characterized with slightly alkaline pH values as well as high concentrations of HCO-3and Na＋,thus their hydrochemical types being predominantly HCO3-Na.The major processes responsible for the formation of high-fluoride groundwaters in the study area include dissolution of fluoride-bearing minerals and ion exchange between OH-in groundwater and F-in mica minerals.In addition,the evaporation in the discharge area and the discharge of industrial wastewaters containing fluoride may also have non-negligible effects on the occurrence of high-fluoride groundwaters.