Electro-osmotic fluxes in multi-well electro-remediation processes

Abstract

In recent years, electrokinetic techniques on a laboratory scale have been studied but few applications have been assessed at full-scale. In this work, a mock-up plant with two rows of three electrodes positioned in semipermeable electrolyte wells has been used to study the electro-osmotic flux distribution. Water accumulated in the cathodic wells when an electric voltage gradient was applied between the two electrode-well rows. Likewise, slight differences in the water flux were observed depending on the position and number of electrodes used and on the voltage gradient applied. Results show that the electro-osmotic flow did not increase proportionally with the number of electrodes used. During the start-up of the study, there was an abrupt change in the current density, pH and conductivity of the soil portions closest to electrodic wells due to electrokinetic processes. These differences can be explained in terms of the complex current distributions from anode and cathode rows.

Keywords:

• Electro-osmosis
• electrochemical technology
• soil remediation
• electrolytic well
• mock-up

Acknowledgments

This work was supported by the MCT (Ministerio de Ciencia y Tecnología, Spain) and by the EU (European Union) through projects CTM2007-60472/TECNO and CTM2010-18833/TECNO.