LAUSR

Abstract The single and combined effects of phyto and electro remediation to decontaminate metal contaminated soil were evaluated in this study. Leaching risks of metals from top soil to groundwater after chelator application were compared under different conditions. Soil from Guiyu (China), a notorious e-waste recycling centre, was remediated by different methods including chelator addition, electric field application and their combination. Ethylene diamine tetraacetic acid (EDTA) was applied as chelator. In electrokinetic and combined remediation experiments, stainless steel sheets were adhered to stems to charge the plant negatively. Chelator can significantly enhance the plant's ability to absorb metals and impel the metals moving from top to deep soil layers. Individual effects of electric field with varied voltages on phytoremediation efficiency were different. The ability of plants to accumulate metals increased with the increase of voltages. The biomass production of plants was enhanced at low (2 V) and moderate (4 V) voltages and decreased at high (10 V). Metal leaching in electrokinetic remediation processes was less significant than in EDTA treatment and the control. Phytoremediation efficiency improved by combining chelator and electric field was up to twice as much as by individual chelator. These results indicated that phytoremediation assisted by electric field is a potential technology to decontaminate large scale fields.