An Enhanced Electrokinetic/Waste Fe(OH)3 Permeable Reactive Barrier System for Soil Remediation in Sulfide Mine Areas

Traditional electrokinetic (EK) technology can remove contaminants from soil, but the efficiency is generally low. This study reports on the combination of enhanced EK and a waste ferric hydroxide (Fe(OH)3) permeable reactive barrier (PRB) for the remediation of soil in sulfide mine areas. Hydroxyethylene diphosphonic acid (HEDP) and FeCl3 were used as a compound chelating agent. The experimental results showed that EK combined with PRB technology (95.32% Cd removal) was more effective than single EK in removing cadmium (Cd) from the contaminated soil, because of the compound chelating agent and PRB filled with sustainable Fe(OH)3 adsorbent. Additionally, the application of PRB in combination with HEDP was able to increase the sulfate removal rate to 96.19%. The accumulated energy consumption of these two systems was 182.4 and 356 kWh/m3, respectively, after EK remediation using PRB.