铬污染土壤浸泡与无水电解电动联合修复实验

对TCr质量分数为2 312 mg/kg的污染土壤进行7轮蒸馏水预浸泡处理,然后再进行无水电解电动修复.污染土壤经过水浸泡、85.4 h和203 h的无水电解电动修复后,TCr去除率分别为45％、67％和84％,表明预浸泡处理可以显著降低铬污染土壤电动修复的负荷.通过采用铁阳极和CuSO4阴极工作液,抑制水的电解,使Fe2+离子和SO42-离子分别替代H+离子和OH-离子进入土壤,可以提高铬(Ⅵ)的电迁移数,提高铬污染土壤电动修复的电流效率.

Water dipping and electrokinetic jointed remediation of chromium-contaminated soil without water electrolysis

A heavily chromium-contaminated soil with total chromium (TCr) concentration of 2 312 mg/kg is dipped in distilled water seven times before electrokinetic remediation without water electrolysis (EKRWWE). The TCr removal rates of 45%, 67% and 84% are respectively achieved after water-dipping, 85.4 h EKRWWE and 203 h EKRWWE in order, demonstrating that pre-dipping treatment is able to significantly reduce the load of EKRWWE. In order to prevent electrolysis of water, iron is used as anode and CuSO4 solution is used as cathode electrolyte. Consequently, Fe 2+ ion instead of H + ion and SO 2-4 ion instead of OH - ion migrate into soil and a higher transference number of CrO 2-4 ion is achieved which means a higher efficiency of electrokinetic remediation of chromium-contaminated soil.