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. The application of chelators is widely used to improve phytoremediation efficiency whilst some of scientists, recently, pay more attention to the use of electrokinetic combined with chelators. The objective of this study was to determine the effect of EDTA, cow manure extract (CME) and poultry manure extract (PME) combined with an electrokinetic system on the efficiency of phytoremediation. In a pot experiment four graphite electrodes were placed around each pot as anodes and a central electrode was placed as a cathode to accumulate Pb cations in central part where a sunflower’s seedling 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 each 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.
Pb polluted soil; phytoremediation; chelator; electrokinetic;