Exchange electrode-electrokinetic remediation of Cr-contaminated soil using solar energy

The present work focused on analyzing the effects of solar energy on the electrokinetic remediation (EKR) of Cr-contaminated soil, compared to direct current (DC) power supply. Meanwhile, to control the remedied soil pH and focusing phenomena, the exchange electrode-EKR (EE-EKR) has also been employed. Four runs of tests were conducted using DC power supply with the conventional EKR (run A, run D), DC power supply with EE-EKR (run B) and solar energy with EE-EKR (run C) respectively. Important electrokinetic parameters such as electrical voltage and current, electroosmotic flow, soil pH, the remediation efficiency of total Cr, Cr(VI), Cr(III) and cost analysis were investigated to evaluate EE-EKR using solar energy. The results show that run B had the highest removal efficiency of total Cr (43.65%), Cr(VI) (91.88%), and Cr(III) (19.32%), and run C, run A, run D follow in turn. It was proved that EE-EKR could increase the removal efficiency of Cr, especially Cr(III) from contaminated soil, because it could reduce focusing phenomena and enhance electrical current. Meanwhile, the experimental results also indicated that the combination of electrokinetics and solar energy was feasible and effective to some extent for the remediation of Cr-contaminated soil.