Effect of chemical additives on electrokinetic remediation of Cr-contaminated soil coupled with a permeable reactive barrier

Chromium(Cr) contamination in soil, especially Cr(VI) has a serious threat to the environment and human health. The electrokinetic remediation (EKR) is a promising technology to remediate the Cr(VI). Therefore, EKR coupled with a permeable reactive barrier (PRB) was used to treat the Cr(VI) contaminated soil in this study. The CTMAB-Z, a modified zeolite (prepared by cetyl trimethyl ammonium bromide) alone and a mixture of CTMAB-Z and Fe(0) were used as PRB-1 and PRB-2 reactive media, respectively. The effect of chemical enhancers/additives i.e. dl-tartaric acid and tween 80 on EKR of Cr(VI) was also analysed in the contrasting experiments. While, the effects of repair time, voltage gradient and dl-tartaric acid concentration on Cr(VI) remediation were investigated by utilizing multifactor orthogonal experiment which was based on contrasting experiments. The contrasting experiment results showed that the highest Cr(VI) removal rate(66.27%) and leaching efficiency(71.29%) were observed i...