Cadmium and lead bioaccumulation potentials of an aquatic macrophyte Ceratophyllum demersum L.: A laboratory study

Cadmium (Cd) and lead (Pb) pollutions caused by industrial activities are one of the most serious threats to aquatic ecosystems. The aim of this study is to investigate the Cd and Pb bioaccumulations and diverse physiological and biochemical properties of Ceratophyllum demersum L. exposed to different concentrations of Cd (0.5-2.0 mg/L) and Pb (25-100 mg/L) in aqueous media for 1, 3 and 5 days. Cd and Pb accumulations increased with increase in the exposure times and concentrations, and the highest accumulation values of Cd and Pb were recorded at 2 mg/L (2668.33 mg/kg dw) and 100 mg/L (22,504.10 mg/kg dw), respectively, after 5 days. However, higher bioconcentration factors (BCF) were calculated as 645.43 at 25 mg/L Pb and as 1357.92 at 1 mg/L Cd after 5 days. The results showed that photosynthetic pigments (chlorophyll a, b and carotenoids) and protein contents of the plants exposed to Cd and Pb toxicities decreased with increasing metal concentration and exposure time, whereas their malondialdehyde (MDA) contents increased. Additionally, the single and synergistic effects of duration and metal concentration on the fresh and dry weights of the plant were determined. The results of this study reveal that C. demersum, propagated by tissue culture technique, can be used effectively in the phytoremediation of aquatic environments contaminated by Cd and Pb. This study will also make a positive contribution to the progression of new phytotechnologies on the purpose of the remediation of wastewater by plants in future.