Potential of Lead and Cadmium Accumulation in Washingtonia filifera

Abstract

In the present study, one-year-old Washingtonia filifera was used to determine the comparative study of uptake of the toxic heavy metals Cd and Pb. Seedlings were evaluated under 0, 50, 250 and 500 mg dm−3 concentrations of both heavy metals for 45 days. Some growth parameters such as shoots and roots length, collar diameter, fresh and dry weights and also uptake of heavy metals were determined in response to Cd and Pb stress. Results showed that Cd and Pb treatments decreased growth parameters and Cd was found to be more detrimental than Pb treatments. The total fresh and dry weights and plant height were lower by 50, 56, 55 and 17%, 18%, 30% in Cd and Pb treatments, respectively, compared with the control. The amounts of accumulated Pb and particularly Cd were much higher in the roots than in aboveground parts of all treatments. W. filifera accumulated large amounts of the toxic heavy metals Cd (1166–5800 mg kg−1) and Pb (826–2433 mg kg−1) in roots and about 4046 mg kg−1 of Cd and 1873 mg kg−1 of Pb were determined in aboveground parts. Based on the calculated Bio-Concentration Factor and Translocation Factor values, W. filifera has the potential for phytostabilization programs. Also it was found to be the candidate for phytoremediation programs of polluted soils with Cd better than Pb.