The use of eleetrokinetic processes for treatment of polluted soils has attracted considerable attention, partly because experiences with electroosmotic procedures in soil dewatering and partly because of the relative simplicity of the field application method. The procedure relies heavily on the fundamental aspects of electrochemistry that govern the movement of ionic species, i.e. anions and cations, to the selective electrodes. In this paper, the fundamental laws that govern the electrochemical movements as well as the resulting changes of the electrochemical properties of polluted soils are discussed. Experimental results obtained from the application of electrokinetic processes are also discussed. Furthermore, enhancement ofthe electrokinetic remediation via the use of ion selective membranes is discussed. The experimental results have shown the potential advantage of using ion selective membranes in to combat the shortcomings of the traditional use of electrokinetic remediation.
In 1939, Leo Casagrand used electrokinetic process to stabilize railroad in Salzgitter, Germany (Casagrande, 1983). Since then, the process has been investigated and used by geotechnical engineers to improve the stability of excavated earth materials, increase the strength of pile foundations, stabilize soft sediments (Lo et al., 1991; Shang and Dunlap, 1996, 1998), and dewater sludge (Mohamed and Saleh, 1997), dredged sediments, and mine tailings. Recently, geoenvironmental engineers have used the electrokinetic process to divert polluted plume, modify groundwater flow, contain polluted soil and groundwater (Yeung and Mitchell, 1993), repair failing containment barrier systems, and treat in-situ polluted soils (Segall and Bruell, 1992; Probstein and Hicks, 1993; Allen and Chen, 1993; Acar et el., 1994; Hicks and Tondorf, 1994; Yeung and Datla, 1995; Moharned, 1997a&b) In-situ electrochemical soil remediation is a recent technology that may be applied to fine grained, low hydraulic conductivity soils, for which most other remediation techniques are in- efficient. Electrochemical remediation, variably named electrokinetic soil processing, electroreelamation.
