The remediation of arsenic polluted soil from a mining area in China using the electrokinetics process coupled with zero-valent iron permeable reaction barrier was researched. The influence of soil moisture content and enhancement reagents on arsenic removal was investigated. The changes of distribution and valence state of arsenic before and after the remediation were analyzed. In addition

surface features of the fresh and used zero-valent iron were characterized by X-ray photoelectron spectroscopy (XPS). Then synergistic effects of EK/PRB in the remediation of arsenic-contaminated soil was discussed. The results showed that in the EK/PRB remediation process

fraction of the EK removal mechanism was 22% to 43%

while fraction of the PRB removal mechanism was 52% to 71%

so the PRB process was dominate. When the enhancement reagents was absent

arsenic mainly tends to move toward the anolyte

which indicated the mainly removal mechanisms was electromigration. However

when the enhancement reagents was added

the proportion of arsenic collected from the cathode solution was significantly increased. After EK/PRB remediation

the percentage content of As(Ⅴ) and As (Ⅲ) in soil

electrode liquid and PRB had no substantial changes

only the content ratio of As(Ⅴ) raised slightly. Pentavalent arsenic will not be reduced into trivalent arsenic with higher toxicity. There were no As(0) but As(Ⅲ) and As(Ⅴ) on the surface of the used Fe0. Therefore

arsenic was removed in PRB only through adsorption of the iron surface oxides.