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

Subject Areas : environmental management

Sara Mirzaie ¹ , Mohsen Saeedi ² , Nader Shariatmadari ³ , Hossein Fakhraee ⁴

1 - MSc Student, School of Civil Engineering, Iran University of Science & Technology, Tehran, Iran
2 - Corresponding Author, Environmental Research Laboratory, Department of Hydraulics & Environment, School of Civil Engineering, Iran University of Science & Technology, Tehran, 16846, Iran.
3 - Department of Geotechnical Engineering, School of Civil Engineering, Iran University of Science & Technology, Tehran,16846, Iran.
4 - Health, Safety and Environment Institute, Malek Ashtar University of Technology

Received: 2009-07-23 Accepted : 2010-01-23 Published : 2015-06-22

Keywords:

Abstract :

Introduction:Contamination of soils by heavy metals has become an important issue inenvironmental 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.Material and methods: 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 barrieris investigated in the present study.Results: the research showed that the reduction efficiency could be improved to 20% when nZVIbarrier is used. pH value in EK-nZVI experiments was maintained at 2 and 4 in anode reservoir aswell as anode-cathode reservoirs. The results revealed that in lower pH conditions, the reductionefficiency was improved up to 82%.

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