The Effect of Using EDTA on the Uptake of Lead and Cadmium by Wheat

Lead (Pb) and cadmium (Cd) are among heavy metals which enter water, soil, plants and ultimately the human and animals food chain from various resources. Several methods has been suggested for remediation of contaminated soils which are mostly very expensive and therefore the use of less expensive methods to remove contaminated soils can help to purify and use these lands optimally. Phytoremedian is one of the low cost and environmentally friendly methods. Use of chelates is one of the effective approaches for increasing the bioavailability of heavy metals. Therefore, In this study, the effect of Ethylene Diamine Tetra-acetic Acid (EDTA) as a chelating agent on incresing absorption of Pb and Cd by Wheat (Bahareh) were studied. A pot experiment was conducted in the greenhouse with a factorial and completely randomized design with three replications. Factors including: 1- EDTA application in two levels (0 and 2.7 mmolkg-1 soil), 2- Pb at three levels ( 0, 150 and 500 mgkg-1 soil) and 3- Cd in three levels (0, 3 and 10 mgkg-1 soil). Consequently, a non-contaminated soil was selected and contaminated with different amounts of Pb and Cd. Then, Wheat seeds were planted and after harvest, Pb and Cd concentration in plants (grain and straw) and soil was measured. The results showed that EDTA application was able to increase Pb and Cd solubility in soil solution, resulting an increase in absorption of Pb in straw (12.5 times) and grain (68.8 times) and Cd in straw (26 %).