复合重金属污染高岭土的电动修复

根据电子废弃物拆解场地的污染特征,以复合重金属(Cu,Cd,Pb)污染高岭土为研究对象,考察了电动技术对污染土壤的修复效果。实验结果表明:在电压梯度为1 V/cm、阳极液为自来水、阴极液为柠檬酸-柠檬酸钠缓冲液(pH=5)、靠近阴极设置活性炭渗透反应墙(PRB)的条件下电动修复96 h后,Cu,Cd,Pb的平均去除率分别可达79.93%,99.43%,39.36%;土壤的酸碱性对电动修复效果影响显著,通过在阴极添加缓冲液维持土壤偏酸性条件,有利于重金属污染物的电动去除;在靠近阴极设置活性炭PRB可富集重金属,减少阴极液的污染;迁移率大的酸可提取态重金属较易去除,残渣态重金属稳定性强,去除率较低。

Electrokinetic remediation of kaolin contaminated with multiple heavy metals

According to pollution characteristics of e-waste dismantling sites,kaolin contaminated with heavy metals （Cu,Cd,Pb） was selected as the research object,and the remediation effect by electrokinetics method was investigaeted. The experimental results showed that：Under the conditions of voltage gradiant 1 V/cm,using tap water as the anolyte and the citric acid-sodium citrate buffer solution （pH=5） as the catholyte,installing the activated carbon permeable reactive barrier （PRB） near the cathode and electrokinetic remediation time 96 h,the average removal rate of Cu,Cd,Pb was 79.93%,99.43%,39.36%,respectively;The pH of kaolin had significant impact on electrokinetic remediation,the electrokinetic removal of heavy metals was benefited from keeping a slightly acidic kaolin condition through the addition of buffering solution;The pollution of the catholyte could be reduced by enriching heavy metals on the activated carbon PRB near the cathode;The removal of acid-extractable-form heavy metals with high mobility was relatively easy,while the removal rate of residual-form heavy metals with high stability was low.