Phytoremediation of Chromium and Lead Using Water Lettuce (Pistia stratiotes L.)

Heavy metal pollution of water is of concern for human health and ecosystem. Under present investigation Pistia stratiotes L. (water lettuce) has been tested for removal of two important heavy metals chromium (Cr) and lead (Pb) from metal solution. This species was grown at four concentrations of Cr and Pb, i.e. 5.0, 10.0, 15.0 and 20.0 mg/L, respectively in single metal solution. This aquatic macrophyte has successfully removed up to 80% of Cr and 93% of Pb after 10 days. The bioconcentration factor (BCF) value ranged between 299 and 1026 for Cr and between 1672 and 1852 for Pb, respectively. The amount of BCF in Pistia stratiotes showed that removal of Pb was higher than removal of Cr. The accumulation of heavy metals was more obvious in the roots as compared to leaves. These findings contribute to the application of aquatic macrophytes to lead and chromium removal from moderately contaminated waters.