Heavy metal pollution of soil is a significant environmental problem. It has negative impact on agricultural products and human health. The clean up of metal-contaminated soils by traditional physicochemical methods is both very costly and destructive to the normal properties of the soil. In contrast, phytoremediation, that use of green plants to decontaminate the metals out the soil is an emerging technique with advantages of being in situ, cost effective and environmentally sustainable. Enhanced phytoextraction of heavy metals using chelating agents and agricultural crops is widely discussed as a remediation technique. The objective of this work, therefore, was to examine the effect of EDTA as a synthetic chelator, on the plant growth, the uptake and translocation of Ni and Cd within corn (Zea mays) grown on a contaminated soil. In this study, phytoextraction efficiency of Zea mays after applications of EDTA (3mmol kg-1 soil) was tested on the laboratory scale in a soil contaminated with Cd (10 mg kg-1 soil) and Ni (300 mg kg-1 soil) as pollutants. EDTA effectively increased the mobility of target heavy metals (Ni and Cd) in the soil solution. The results showed that the content of Cd was significantly lower in both, roots and shoots. However, biomass production, leaf area, root volume, and plant height in corn dropped after EDTA addition in the experiment. Moreover, the contents of Ni enhanced in corn shoots. Application of 3mmol kg-1 EDTA to soil significantly decreased remediation factor of Ni and Cd in this experiment. Compared with this results, lonely increased The remediation factor of the metals studied was promoted using Z. mays in the absence of EDTA in polluted soil. This observation may make the use of EDTA not suitable for the remediation of severely heavy metal contaminated soils by Z. mays in a reasonable time frame and may result in substantial environmental pollution under these conditions.

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