Tolerance of Vallisneria sp. for Different Concentrations of Cadmium and Lead

This study was done to recognize the tolerance of Vallisneria sp. for different concentrations of cadmium and lead in aqueous ecosystem. The concentrations of 30, 40, 50 mg/L were used for Cd and Pb in three replications for each concentration for 30 days. The results found that the plant was tolerated 50 mg/L of Pb, and 40 mg/L of Cd. Significant differences were found in removing capacity by plant for Cd and Pb, in all concentrations 30, 40, 50 mg/L during experiment period. There were no morphological changes in the first day of the experiment period, but it was appeared after the threeth days of the experiment, and it continued till the end of the experiment. The highest removal ratio for Pb was 97.66% in the concentration 30 mg/L, and the lowest removal ratio was 57.4% in the concentration 50 mg/L. For Cd the highest removal ratio 80.06% in concentrations 30 mg/L and the lowest removal ratio was 76.2% mg/L in concentrations 50 mg/L.