Phytoremediation potential of Cd and Pb-contaminated soils by Paspalum fasciculatum Willd. ex Flugge

The phytoremediation capacity of Paspalum fasciculatum Willd. ex Flugge, was evaluated in soils from a gold mine contaminated with cadmium (Cd) and lead (Pb), using three concentration levels of each metal (15, 30, and 50 mg kg(-1)). Their ability to assimilate Cd and Pb in its different tissues was evaluated during 90 days of exposure. Plant growth behavior, accumulation of Cd and Pb, and translocation (TF) and bioaccumulation (BAF) factors were also determined. During the first 60 days of exposure, Cd had an inductive effect on the growth of P. fasciculatum; however, after 90 days, this metal had begun to show toxic effects. Plants showed a similar pattern of accumulating Cd and Pb in their tissues with concentrations decreasing in the order roots > leaves > stem. However, the accumulated concentrations of Cd were generally higher than those of Pb with the highest metal uptakes being observed during the first 30 days of exposure. P. fasciculatum was shown to have a phytostabilization effect with regard to Cd, high concentrations of metals in tissues and little translocation, whereas it showed phytoextraction capacity for Pb. In addition, it can increase pH and organic matter in the soil rhizosphere.