Enhanced Electrokinetic Techniques in Soil Remediation for Removal of Heavy Metals

Anthropogenic contamination of soil is a serious environmental problem that poses risks to human life and biota. Novel remediation technologies are required to mitigate contamination caused by heavy metals and organic pollutants. Due to the low efficiency of soil remediation under complex conditions like low permeability and heterogeneous subsurfaces, electrokinetics has emerged as a better tool for remediation. In electrokinetic remediation, electrodes with a low electric current or low potential gradient are inserted into the ground to remove soil contaminants. The charge gradient obtained by the applied electric field initiates the mitigation of contaminant metal ions via movement of charged chemicals (electromigration), movement of fluid (electroosmosis), and chemical reactions (electrophoresis). However, soil contaminated with mixed pollutants such as combinations of organic matter, heavy metals, and radionuclides is difficult to remediate with the usual electrokinetic techniques. Therefore, combining electrokinetic techniques with other means of remediation enhances the efficiency of removing heavy metals from severely contaminated soils. This chapter focuses on combinational factors to enhance removing heavy metals from contaminated soils.