Electrokinetic remediation of uranium(VI)-contaminated red soil using composite electrolyte of citric acid and ferric chloride

In the process of electrokinetic (EK) remediation of uranium-contaminated soil, the existence form of uranium in soil pore fluid will affect on its migration behavior. In this paper, a novel type of electrolyte (citric acid + ferric chloride, CA+ FeCl₃) has been investigated for the EK remediation of uranium-contaminated red soil. The effects of different electrolyte and the concentrations of FeCl₃ on migration behavior of U(VI) and environmental risks were investigated after EK remediation. The result showed that the optimum concentration was 0.1 mol/L CA mixed with 0.03 mol/L FeCl₃ in this study. At this time, the removal efficiency of uranium was about 61.55 ± 0.41%, and the cumulative energy consumption was 0.2559 kWh. Compared with deionized water and single CA, combined CA with FeCl₃ has the advantages of high removal efficiency, low leaching toxicity, and less damage to the soil after the electrokinetic remediation treatment.