基于电絮凝法处理矿区高浓度含氟地下水动力学分析

采用铝电极电絮凝体系对矿区高含氟地下水进行处理，研究了高氟浓度下电絮凝除氟过程，分别考察了电流密度、极板间距、进水氟质量浓度及pH对除氟效果和动力学常数的影响，并建立了电絮凝除氟动力学方程模型。结果表明：最佳除氟参数为电流密度为450 A·m⁻³，极间距为5 mm，pH为6.0~7.0；当进水氟质量浓度为12.1 mg·L⁻¹时，经60 min电絮凝除氟后可使进水氟质量浓度由12.1 mg·L⁻¹降为0.6 mg·L⁻¹以下，整个除氟过程遵循一级反应动力学模型且除氟动力学常数取决于电流密度、极板间距和进水氟质量浓度。絮体结构与成分分析表明，在pH=6.0~7.0条件下，电絮凝体系中主要形成的无定型羟基铝化合物使除氟效果达到最好，较高的进水氟质量浓度有助于提高铝离子利用效率。

Kinetic analysis of treating high fluorine groundwater in mining area by electrocoagulation

The defluoridation process with aluminum electrode electrocoagulation was used to treat high fluorine groundwater in the mining area. The effects of current density, electrode distance, initial influent fluoride concentration and pH values on the defluoridation effect and kinetic constant were investigated, respectively. The kinetic equation model of defluoridation was also established. The results showed that the fluoride concentration could be reduced from 12.1 mg·L−1 to 0.6 mg·L−1 after 60 minutes of electrocoagulation reaction at the optimal operational parameters: current density of 450 A·m−3, electrode distance of 5 mm and pH 6.0~7.0. The defluorination process followed the first-order reaction kinetic model, and the kinetic constant for defluoridation depended on the current concentration, electrode distance and initial fluoride concentration. The analysis of floc structure and composition showed that the amorphous hydroxy aluminum compound occurred in the electro-flocculation system at pH=6.0~7.0, which resulted in the best fluoride removal effect and high fluoride concentration in the influent water was conducive to the increase of the utilization efficiency of aluminum ions.