Phytoremediation Potential of Populus Alba and Morus alba for Cadmium, Chromuim and Nickel Absorption from Polluted Soil

Metal pollution has become one of the most serious environmental problems resulting from human activity. Phytoremediation utilizes plants to uptake contaminants and can potentially be used to remediate metal-contaminated sites. The present study investigates heavy metal uptake (Cd, Cr, and Ni) from soil by different organs of Populus alba and Morus alba. For this purpose, Cd (40, 80, and 160 mg/kg), Cr (60, 120, and 240 mg/kg) and Ni (120, 240, and 480 mg/kg) were added to the soil in pot experiments over the course of a growing season in open air. The total concentration of these metals was measured in the roots, stems, green leaves, fallen leaves, and the corresponding soil. Our results show that the highest accumulation of all studied metals was found in the leaves. Furthermore, the fallen leaves had higher concentrations of Cd and Cr in P. alba and Cr and Ni in M. alba when compared to the green leaves. In the two species, Cd and Ni did not transport from the leaves to the roots and stems, or vice versa, in the fall season, but Cr was transported from the roots and stems to the leaves in the 240 and 480 mg/kg treatments.In addition, the determination of a bioconcentration factor and a translocation factor showed that P. alba and M. alba were suitable for phytoextraction of Cd and Ni in all treatments respectively; however, none of the plants was suitable for phytostabilization.