Integrated solar electrokinetic remediation of soil contaminated with copper

Abstract

Electrokinetic remediation is an emerging in-situ technology for cleaning contaminated soil. The contaminants are mobilized by passing a low-level direct current between a row of positively charged electrodes (anode) and negatively charged electrodes (cathode). Due to the low electric current required by the technology, solar power can be an excellent option for providing the electric field. Along with the environmental benefits of solar power, solar cells can provide electricity in remote sites with no access to power lines. The electrolysis reactions in electrokinetic process generate an acid front at the anode and a base front near the cathode. The acid front travels by electroosmosis and electromigration towards the cathode, while the base front moves by electromigration to the anode. The base front reacts with the cations in the soil pore fluid causing premature precipitation of the cations as heavy metal hydroxides at a distance from the cathode equal 0.3 to 0.5 times the distance between the electrodes.