Ceratophyllum demersum L. as Phytoindicator and Potential Phytoremediator of Lead Under Hydroponic Conditions

[EN] The contamination of water by heavy metals like Pb is a huge problem for the environment. In this paper, we test Ceratophyllum demersum L. plants as phytoindicator. These were exposed to different concentrations of Pb for 1¿21 days, under hydroponic conditions, where they exhibited both adsorption and absorption efficiency. These efficiencies influenced in concentration and duration in a dependent manner. For the three initial treatments 0.125, 0.250, 0.500 ¿g/ml, the values of regression coefficients described the occurred variance on the rapid decrease in the Pb concentration in the hydroponic media, reflecting highest removal efficiency by C. demersum. Significant variation (P< 0.05) was recorded between the concentration of Pb accumulated in C. demersum at 0.125 and 0.250 ¿g/ml, while a highly significant value (P< 0.01) was recorded between them at 0.500 ¿g/ml. The regression coefficient denotes the pronounced impact of treatment concentration on the accumulation rate (R^2 = 0.9987). The adsorption efficiency of C. demersum appeared to be influenced by the Pb hydroponic media concentration, where after 21 days, the higher Pb adsorption was recorded at 0.125 ¿g/ml and the lowest one was obtained at 0.500 ¿g/ml. Results suggest that plants responded positively to the increase of Pb concentrations and they accumulated a high amount of metal. Due to metal removal coupled with detoxification potential, the plant appears to have potential for its use as phytoremediator species in aquatic environments.