Phytoremedial potential of aquatic macrophytes for the removal of copper in contaminated waters

Abstract

The aim of this study is to identify the potential aquatic macrophytes to be used for phytoremediation and to compare the reduction of copper by two species of aquatic plants. Two aquatic plants; Centella asiatica and Eichhornia crassipes, the effectiveness were evaluated for their capabilities of copper removal from copper solution. The aquatic macrophytes were placed for 7 days in 6 liters of solution that contained 1 mg/L, 3 mg/L and 5 mg/L of copper. Atomic absorption spectrometer (AAS) was used to conduct analyses of heavy metals contents. It was shown in the results that Centella asiatica achieved complete removal of 1 mg/L copper concentration after the third day of treatment. Centella asiatica also displayed maximum removal of 92% of 3 mg/L copper concentration and 62% for 5 mg/L copper concentration. The peak efficiency at the end of the experiments were at almost similar for Eichhornia crassipes, 83% for the 1 mg/L concentration, 80% for the 3 mg/L concentration and 83% for the 5 mg/L concentration. Overall, Centella asiatica exhibit faster removal rate of copper compared to Eichhornia crassipes. In terms of effectiveness, the percentage removal in solution was higher using Centella asiatica at lower concentration of copper. However, at higher concentration of copper (5 mg/L), Eichhornia crassipes was found to be more effective in removing copper compared to Centella asiatica.