EDTA Enhanced Phytoextraction Capacity of Scirpus Maritimus L. Grown on Pb-Cr Contaminated Soil and Associated Potential Leaching Risks

Abstract

A pot experiment was conducted to study phytoextraction efficiency of Scirpus maritimus L. for lead and chromium and to determine EDTA (ethylenediaminetetraacetic acid) enhancement of the mobility and phytoextraction of Pb and Cr and the potential for leaching of metals. The results revealed that the bioconcentration factors of underground organs were relatively higher and metals concentrations in the plant organs decreased in the order of roots› rhizomes› leaves› stems. Thus, the plant species would be applicable for Pb and Cr phytostabilization. Addition of EDTA (2.5, 5, 10 mmol kg −1 ) to polluted pots significantly enhanced the mobility of soil metals and led to elevated soil solution concentrations of Pb and Cr. Positive correlation coefficients were found between treatment time and metals concentrations in the plant organs. Optimum phytoextraction was observed when 5 mmol kg -1 EDTA was added in single dosage 60 days after the plant cultivation and consequently soil metals concentration decreased with the passage of time. It can be concluded that of Scirpus maritimus L can remediate Pb-Cr contaminated soils and EDTA (at low doses) had potential to promote the uptake of Pb and Cr for the plant species in eco-friendly manner.