Electrokinetic Remediation of Contaminated Soils

Abstract

Electrokinetic remediation is an emerging technology that can be used to remove contaminants from heterogeneous fine-grained soils in situ. Contaminants in the subsurface are removed by the application of a low level direct current electric field across the contaminated soil. The primary contaminant transport and removal mechanisms are electroosmotic advection and ionic migration. However, there are many complex physicochemical reactions occurring simultaneously during the process that may enhance or retard the cleanup process. Nevertheless, the feasibility of the process has been demonstrated by results obtained from many bench scale and large scale laboratory and pilot scale field experiments performed on various soils. This paper reviews the fundamental concepts and the practical aspects of the technology. Laboratory studies of the technique are outlined and major factors affecting the removal process are examined. Enhancement techniques and hybrid process are considered and examples of field trials are described.