摘要：土壤重金属污染具有普遍性、隐蔽性、滞后性、长期潜伏性、治理难[1]且周期长等特点，常见的重金属污染物主要有铬、汞、镉、铅、铜以及类金属砷等。电动技术应用于重金属污染土壤修复，可提高经济效益，减少与有害物质的直接接触，更为安全高效。论文采用电动修复技术对铬和铜污染高岭土进行了实验室修复研究，重点考察电动修复重金属污染土壤的修复效果及影响因素。

实验结果表明，土壤中铬的去除率与施加电压、停留时间、含水率呈正相关，与污染物初期浓度呈负相关，及时更换电极与增大电极反应接触面积可以提高去除率，最大去除率可达98.2%。在污染物初始浓度为5.24mg铬/kg土时确定最佳电压梯度为1v/cm，含水率在35%以上，污染物初始浓度分别为2.62、5.24、7.86mg铬/kg土时2天后铬的去除率分别可达96.2%、92.3%、72.1%，说明在较低浓度污染时，污染物初始浓度与去除效率成反比。在修复过程中，阳极石墨电极溶出严重，电流密度先短暂上升然后缓慢下降，在每次更换电极时有小幅度上升，但在1小时内回归趋势；铬向阳极方向迁移，靠阴极土样去除效率大于靠阳极土样；阴阳池中电解液pH变化迅速，10min后阳极液pH为2~3，阴极液pH为10~11，电解作用明显；土壤含水率在处理过程中出现上升。

在铜污染土壤的电动实验中，选用硝酸铜作为污染物，0.05mol/L的氯化钾溶液作为电解液，污染物初始浓度为5mg/kg时，施加电压梯度为1V/cm，可知铜向阴极方向迁移，在第3天时去除效率较前两天有大幅度提高，为最佳经济停留时间，最大去除效率可达80%左右。与电动修复铬污染土壤相比，最终处理效果较差且达到相同处理效果所需时间较长。

关键词：电动修复，重金属污染，电流密度，电压梯度

Abstract：Soil heavy metal pollution has the characteristics of universality, concealment, hysteresis, long-term latency, difficult management[1] and long cycle. Common heavy metal pollutants are chromium, mercury, cadmium, lead, copper and metal arsenic and so on.Electric technology used in heavy metal pollution of soil remediation, can improve economic efficiency and reduce direct contact with harmful substances, more safe and efficient.In this paper, the electromechanical repair technology was used to study the chromium and copper contaminated kaolin.Focusing on the effect of electric repairing heavy metal contaminated soil and its influencing factors.

The results showed that the removal rate of chromium in soil was positively correlated with the applied voltage, residence time and water content, and negatively correlated with the initial concentration of pollutants.Replace the electrode with the use of coarse graphite electrode can improve the removal rate.The maximum removal rate of up to 98.2%.When the initial concentration of pollutants is 5.24mg chromium / kg soil, the optimum voltage gradient is 1v/cm, the water content is better more than 35%.The removal rates of chromium were 96.2%, 92.3% and 72.1%, respectively, when the initial concentration of pollutants was 2.62, 5.24 and 7.86 mg chromium /kg soil.It is shown that the initial concentration of pollutants is inversely proportional to the removal efficiency at lower concentrations.During the repair process, the anode graphite electrode dissolves out seriously.The current density rises briefly and then slowly decreases, with a slight increase in the replacement of each electrode, but returns within 1 hour.The chromium moves toward the anode,The removal efficiency of chromium near the cathode soil is greater than that of the anode soil.Electrolyte pH changes rapidly,After 10min, the pH of the anolyte was 2 ~ 3, the pH of the catholyte was 10 ~ 11, show that the electrolysis effect was obvious.The soil moisture content in the processing process has increased.