In situ electrokinetic remediation of toxic metal-contaminated soil driven by solid phase microbial fuel cells with a wheat straw addition

BACKGROUND: Toxic metals may accumulate within organisms and inevitably threaten humans and ecosystems, through the food chain. Thus, developing effective and cheap ways to control and remediate toxic metal pollution in soil is a considerable challenge to research and application. This preliminary study illustrates how a solid phase microbial fuel cell (SMFC) can drive the in situ electrokinetic (EK) remediation of toxic metal-contaminated soil. RESULTS: SMFCs with different concentrations of wheat straw, using several configurations, were tested and compared. SMFCs were used to drive the electromigration of Pb and Zn in contaminated soil, and the removal efficiency of these SMFCs gradually increased with the straw ratio. After operating for 100 days, the removal efficiencies for Pb and Zn were 37.2% and 15.1%, respectively, in the anode region of the SMFC with 3% straw. The Pb and Zn fractions were analyzed after the SMFC treatments using a sequential extraction method. The different distributions of the fractions of Pb and Zn in the soil led to variations in removal efficiency. CONCLUSIONS: Compared with the use of traditional EK remediation, use of SMFC-driven EK remediation technology in soil could reduce energy input, reuse biomass energy and reduce the risk of toxic metal leaching into groundwater. This study provides a simple, low cost and environment-friendly method for soil remediation.