Study on electrokinetic remediation efficiencies of different fractions of heavy metals in soils
动电修复不同形态重金属污染土壤效果研究

The research focused on the relationship between the removal effictiveness of heavy metals by the electrokinetics and the forms of heavy metal in soil near Longyan steel and iron works and analyzed the electric energy expenditures. The order of removal rates of heavy metals by electrokinetics in its different speciations was exchangeable fraction>carbonates >Fe/Mn oxides>organic/sulfides>residual fraction in the identical kind of heavy metals.The removal efficiencies of high mobile and weakly bound heavy metals were higher, such as the exchange fraction were more than 95% by electrokinetic treatment, but immobile and strongly bound fraction were not significantly removed, such as organic and residual fraction were less than 29% removal efficiencies.The removal efficiencies of Cd,Cu and Zn in their various forms were significantly higher than corresponding that of Pb. The results of energy consumption analysis indicated that the energy expenditures increased significantly, but the removal rates of the heavy metals elevated a little when the test time continued for more than 96 hours.