Effects of pH controlling to enhance the electrokinetic coupled with nZVI barrier, for remediation of Cr (VI) contaminated kaolinite

Contamination of soils by heavy metals has become an important issue in environmental problems. Chromium contamination has been found in industrial areas and occurs intwo oxidation states in soils: Cr (VI) as a toxic metal by significantly high mobility and Cr (III) as anontoxic with lower mobility compared to Cr (VI) which strongly adsorbed onto soils. Electrokinetic (EK) coupled with permeable reactive barriers (PRB)-particularly nano scale zero valent iron (nZVI)- is among innovative technologies of soil remediation.The effectiveness of pH controlling at EK process reservoirs, in the case of electrokinetic-nZVI barrier is investigated in the present study. the research showed that the reduction efficiency could be improved to 20% when nZVI barrier is used. pH value in EK-nZVI experiments was maintained at 2 and 4 in anode reservoir as well as anode-cathode reservoirs. The results revealed that in lower pH conditions, the reduction efficiency was improved up to 82%.