The Effect of EDTA Addition on the Phytoremediation Efficiency of Pb and Cr by Echinochloa crus galii (L.) Beave and Associated Potential Leaching Risk

Abstract

Metal-contaminated soils constitute a serious environmental problem with adverse consequences for human health. This study was conducted to determine phytoextraction efficiency of Echinochloa crus galii for Pb and Cr and the EDTA-assisted (0. 2.5, 5, 10 mmol kg⁻¹) phytoextraction and the potential for leaching of the metals during the phytoextraction process. The results revealed that the bioconcentration factors of roots of the plant were relatively higher than the bioconcentration factors of the shoot. Thus, the plant species of E. crus galii would be applicable for Pb and Cr phytostabilization. Addition of EDTA had virtually a significant effect on uptake of the metals by the plant and elevated Pb and Cr concentrations in plant organs as compared with the control. Optimum phytoextraction was observed when 5 mmol kg⁻¹ EDTA was added in a single dosage 60 days after the plant cultivation and consequently soil Pb and Cr concentration decreased with the passage of time.

Keywords:

• Contaminated soil
• EDTA
• Heavy metals
• Echinochloa crus galii

Acknowledgements

The authors thank Shole Baghbani for field assistance in collecting the sediment and plant samples, and Ali Nazarzade for analysis of metals.