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.