Phytoremediation of Metal Contamination: Evaluating Pistia stratiotes and Eichhornia crassipes for Lead and Cadmium Removal

Abstract

Phytoremediation is a cost-effective and ecologically friendly way to remove heavy metals from water. A small-scale experiment was conducted to determine the phytoremediation effectiveness of two macrophytes, Pistia stratiotes and Eichhornia crassipes, in removing lead (Pb) and cadmium (Cd) from prepared metal solutions with varying concentrations (2, 4, 10, and 15 mg/L) over a 28-day period. Atomic absorption spectroscopy (AAS) was used to measure the concentrations of Cd and Pb in the root and shoot tissues. Both aquatic macrophytes removed and accumulated lead and cadmium, albeit to variable degrees. E. crassipes and P. stratiotes accumulated the highest levels of Cd and Pb, at 15 mg L-1, according to the data. The concentrations of Cd in roots and shoots were 52.02 mg kg-1 and 53.82 mg kg-1, respectively. Significant Pb was also observed, with values reaching 73.02 mg kg-1. E. crassipes had the highest bioaccumulation values (78.95 mg kg-1 for Cd and 89.91 mg kg-1 for Pb), but P. stratiotes had the highest accumulation (178.53 mg kg-1 for Cd and 365.10 mg kg-1 for Pb). Translocation factors were low, suggesting the plants are efficient in sequestering metals in their tissues, making them effective for heavy metal cleanup. Higher absorbance of metals was observed in roots as compared to the leaves of both macrophytes. The concentration of metals in the solution significantly decreased from day 1 to day 30. The results of one-way ANOVA showed that removal of Cd and Pb was significantly (p < .05) greater in P. stratiotes.