A Review of Electrokinetic Treatment Technique for Improving the Engineering Characteristics of Low Permeable Problematic Soils

Abstract

The use of electrokinetic (EK) treatment which is a comparatively new methodology is being investigated in some parts of the world as a viable in situ soil remediation and treatment method. The principles of EK treatment method involve applying a low direct current or a low potential gradient to electrodes inserted in the low permeable soils that cannot readily drained. The transportation of charged species across the soil involves several complex mechanisms such as electrolysis, electro-osmosis, electro-migration and electrophoresis. This technique can also be applied/enhanced by introducing desirable non-toxic chemical compounds such as lime or cement solutions to the soil by introducing them at the appropriate electrode. The combined effect of these processes together with various geochemical reactions alters the chemical composition of the soil porous medium and thereby alters the physicochemical properties of the soil. Although the technology has been approved to be practical in many laboratory bench scale experiments and small-scale pilot field tests, complicated features such as many electrochemical reactions and soil contaminant interactions are still not fully understood, therefore there is a need for further research to be conducted for a better understanding of physicochemical changes in problematic soils and efficiency of this newly developed technology.