Application of Electrochemical Technologies to Treat Polluted Soil by Diesel

Abstract

This study reports on the effects of electrokinetic remediation to remove organic contaminants and heavy metals from contaminated soil by using different electrolytes. Ti/Ru_0.3Ti_0.7O₂ electrode with an area of 50 cm² was used as anode, while as cathode a grid of Ti. Different electrokinetic total petroleum hydrocarbon(TPH) removal efficiencies were achieved, depending on the supporting electrolyte used, as follows: Na₂SO₄ (96.46%), citric acid (81.36 %) and NaOH (68.03 %) during the first 15 days of electrochemical treatment. The results described here suggest that the application of electrokinetics can be a promising soil remediation technology; if the soil parameters (electric current and electrolyte) are appropriately controlled based on the understanding of interaction between organic pollutants and soil. The main removal mechanism of diesel from soil was electroosmosis. On the other hand, wastewater collected from the electrokinetic remediation process, which was polluted with TPH, it was successfully oxidized by using electrochemical oxidation treatment. The level of degradation achieved was considerably high (>70%) in all cases, after 10 h of electrolysis.