三维电极电吸附动态反应器的除氟特征研究

采用自制的单极性复合型三维阳极作为第三维电极对含氟水进行动态电促吸附实验,通过研究不同填充床高度、阴阳极板间距、隔膜材料对电促吸附除氟效果的影响,确定反应器的最佳结构参数为:填充床高度20 cm、阴阳极板间距4 cm、隔膜为nafion117膜。工作电压、进水pH、进水流速、共存物质对氟离子去除效果的影响结果表明:在一定范围内增大工作电压,降低进水pH或进水流速均可提高除氟效果。相应的最佳操作条件为:工作电压7 V、进水流速4 mL/min、酸性pH;腐殖酸和碳酸根离子的存在会对氟离子去除产生较强抑制作用,低浓度的氯离子可促进氟离子的电促吸附。扫描电镜(SEM)-电子能谱(EDX)的表征结果显示三维颗粒电极的表面及孔隙内部均可吸附氟离子,且电吸附后并未出现电极腐蚀现象。

Studies on fluoride removal by electroadsorption in three-dimensional electrode dynamic reactor

Electroadsorption dynamic reactor with self-made hydroxyl zirconium oxide as the three-dimensional electrode particles was employed to purify drinking-water contaminated by excessive fluoride.The results showed that the optimum structure parameters for this dynamic reactor with the nafion 117 membrane as the diaphragm was 20 cm height of packed bed,and 4 cm electrode distance.Furthermore,either the voltage increase or the inflow velocity or pH value decrease within a certain range would result in the improvement of fluoride removal efficiency,and the optimal operation conditions gained in this study were voltage of 7 V,inflow velocity of 4 mL/min and acid pH values.The obviously negative effects of humic acid and carbonate ions on fluoride removal efficiency were observed,however,lower chloride ion concentration in the raw water can promote adsorption efficiency of fluoride.In addition,fluoride ions on the surface of three-dimensional electrode particles after electroadsorption were detected by SEM-EDX measurements,and no corrosion was observed.