Phytoremediation potential of Pistia stratiotes and Eichhornia crassipes to remove chromium and copper

Phytoremediation is a cost-effective and eco-friendly process to remove heavy metals from water. A small-scale experiment was conducted to determine the phytoremediation efficiency of two macrophytes, i.e. Pistia stratiotes and Eichhornia crassipes for the removal of chromium and copper from the prepared metal solutions of different concentrations (2, 4, 6, 8 mg/L) for a period of one month. Both aquatic macrophytes showed different efficiency for the removal and accumulation of Chromium (Cr) and Copper (Cu). The dry biomass of both macrophytes increased over the period of time. The average accumulation of chromium in roots and leaves of P. stratiotes was 85 mg, 56 mg and copper was 96 mg and 70 mg, respectively whereas the average accumulation of chromium in roots and leaves of E. crassipes was 90 mg, 53 mg and copper was 86 mg, 50 mg, respectively. 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 Cr was significantly (p < .05) greater in E. crassipes and removal of Cu was significantly (p < .05) greater in P. stratiotes.