Remediation of 2,4-dichlorophenol-contaminated soil by electrokinetic delivery of persulfate technology

2,4-Dichlorophenol (2,4-DCP) is difficult to degrade rapidly in the environment due to its stable chemical properties, so it was easy to lead to serious chlorophenol pollution in soil. Consequently, a remediation method which is efficient, safe, and economical is required. In this study, electrokinetic (EK) remediation was used to transfer sodium persulfate (Na₂S₂O₈) into soil to degrade 2,4-DCP, and the effect of several factors (including the addition location of Na₂S₂O₈, applied voltage, and running time) on the remediation efficiency was explored. The concentration of Na₂S₂O₈, residual efficiency of 2,4-DCP and distribution characteristics of pH, and electrical conductivity were analyzed. The results showed that the cathode was the optimal position to add Na₂S₂O₈. Under this condition, Na₂S₂O₈ was uniformly distributed in the whole soil column through electromigration. The optimal removal efficiency of 2,4-DCP in soil by adding Na₂S₂O₈ was approximately 26% when the voltage gradient was 1.0 V/cm and the operating time was 9 days, which was mainly due to the degradation of S₂O₈^2-.