Absorption and Accumulation of Pb and Cd by Three Pasture Plants

Phytoremediation is a relatively new technique for remediation of contaminated environments. However, until now, no ideal plant has been found for effective remove of lead (Pb) and cadmium (Cd) from soil. The aim of this study was to evaluate the ability of millet (Pennisetum glaucum), couch grass (Triticum repens) and alfalfa (Medicago sativa L.) plants for remediation of Pb and Cd contaminated clay loam soil under greenhouse condition. This experiment was conducted as a factorial experiment based on randomized complete blocks design with two factors of Pb and Cd concentrations (0, 150, 400, 800 and 1500 mg Pb kg-1 and 0, 5, 20, 60 and 100 mg Cd kg-1) and three plants with three replications. Results indicated that Increasing Pb concentration resulted in lesser extraction of Pb by millet and couch grass while alfalfa accumulated higher Pb in its shoots. Uptake of Cd by plants increased as Cd concentration in soil increased. Couch grass and millet showed the maximum and minimum accumulation potential of both Pb and Cd, respectively. Shoot dry mass of the studied plants decreased with increase of Pb concentration in soil.