| EDTA was used as eluent to wash heavy metals from abandoned lead and zinc smelting corporate contaminated soils in
soil columns and studied the removal of heavy metals in the soil under the three conditions of different concentrations, different flow rates and different washing time. The redistributions of heavy metals were determined using the sequential extraction procedure before and after treatment. The results were as followsing:(1) When the concentration of EDTA was 0.01 mol/L, the flow rate was 1 mL/min, the washing time was 24 h, the removal rate of Cu, Pb, Zn were 57.01%, 47.5% and 61.6% respectively. (2) EDTA was very effective in removing the exchangeable, carbonate, Fe-Mn oxide bound and organic-bound states of heavy metals from the contaminated soils. The average removal rates were 76.02%, 60.9%, 57.69%, respectively. The removal of residual heavy metals was not very good. Exchangeable, carbonate and Fe-Mn oxide bound states of heavy metals were with relatively high mobile capabilities and bioavailability, they were more harmful to the environmental. EDTA could effectively remove the forms of heavy metal. So remediation of heavy metals from contaminated soil by washing with EDTA was feasible. |
