Electrokinetic Remediation for Environmental Security and Sustainability

1An Overview of the Modeling of Electrokinetic Remediation

Maria Villen‐Guzman, Maria del Mar Cerrillo‐Gonzalez, Juan Manuel Paz‐Garcia, and Jose Miguel Rodriguez‐Maroto

Department of Chemical Engineering, Faculty of Science, University of Malaga, Malaga 29071, Spain

1.1 Introduction

Electrokinetic remediation (EKR) is based on the application of an electric field to porous solid matrices [1] or suspensions (i.e. solid particles suspended in a well‐stirred aqueous solution) [2]. Due to transport phenomena associated with the applied electric field, ionic and non‐ionic species are mobilized toward the electrodes. Electrokinetic technology has also been widely applied to mobilize reactive particles, such as zero‐valent iron (n‐ZVI), through the soil and groundwater [3].

The basic principle of EKR is the application of an electric potential between two or more electrodes inserted into a solid matrix, resulting in a direct electric current through the medium [4]. At the electrode‐electrolyte interface, the electric current transported by electron flow is transformed into ionic current that flows through the system. The electric current, transported mainly by ionic species, generates hydraulic, chemical, and electric potential gradients through the solid‐fluid system. In EKR, five transport mechanisms coexist: (i) electromigration – movement of ion species (cations and anions) induced by an applied electric current toward the electrode of the opposite charge; (ii) electroosmosis ...