Effects of some chelators and electrical fields on phytoremediation efficiency of a Pb polluted soil

Pb is one of the important and widespread pollutants in soil which impacts on soil health and subsequently food chain. Phytoextraction has been proposed as an inexpensive, environmental-friendly technology for soil remediation. Application of chelators is widely used to improve phytoremediation efficiency whilst some of scientists, recently, pay more attention to use of electrokinetic in collaboration with chelators. Objective of this study was determining the effectiveness of EDTA as a synthetic chelator, cow manure extract (CME) and poultry manure extract (PME) as organic chelators along with an electrokinetic system to obtain a high efficiency phytoextraction technique. In a pot experiment four graphite electrodes were placed around the pot as anodes. A single cathode was placed in the center of each pot to accumulate Pb cations in central part where a germinated sunflower‟s seed was planted close to cathode. After 30 days, the soils were treated with chelators and 2 weeks later electrical fields were applied for an hour per day for 14 days. After harvesting the plants, Pb concentration in shoots and roots, translocation factor of Pb (TF) and Pb uptake index (UI) was analyzed. Results indicated that electrical fields had no significant impacts on these factors. No interaction was found between electrical fields and chelators. PME increased Pb uptake index (UI) to 0.68 mg pot-1 while EDTA reduced it to 0.11 mg pot-1 compare to control (0.30 mg pot-1). CME had no significant impact on UI. All in all PME was the most effective chelator to improve phytoremediation efficiency.

Effects of some chelators and electrical fields on phytoremediation efficiency of a Pb polluted soil Keywords:

Pb polluted soil , phytoremediation , chelator , electrokinetic