*2.1.4 Electrokinetic remediation*

Electrokinetic remediation is an in-situ process in which an electrical field is created in a soil matrix by applying a low-voltage direct current (DC) to electrodes placed in the soil. As a result of the application of this electric field, heavy metal contaminants may be mobilized, concentrated at the electrodes, and extracted from the soil [22]. In this method the separation of heavy metals (loids) in soil is accomplished via lectrophoresis, electric seepage, or electromigration and thus decrease the contamination [12]. Other techniques and processes, such as electrokinetic microbe joint remediation, electrokinetic-chemical joint remediation, electrokineticoxidation/reduction joint remediation, coupled electrokinetic phytoremediation, electrokinetics coupled with electrospun polyacrylonitrile nanofiber membrane, and electrokinetic remediation conjugated with permeable reactive barrier, are also used in conjunction with electrokinetic remediation methods [23, 24]. Soils with low permeability respond well to electrokinetic remediation. Because electrokinetic remediation is simple to set up and utilize, it is cost-effective [25]. Pollutant concentrations in soil are reduced when electrochemical adsorption is combined with extraction using low-molecular-weight organic acids [26–28]. Fluctuations in soil pH are the key limiting factor for direct electrokinetic remediation since it cannot sustain soil pH value [3].
