Effect of concentration and exposure time on copper accumulation in Eichhornia crassipes (Mart.) Solms. (Pontederiaceae)

Abstract

Different factors can influence the absorption and storage of substances in plant biomass. In this study, we evaluated the effect of copper concentration in growth medium and plant exposure time on copper accumulation in Eichhornia crassipes (Mart.) Solms. (Pontederiaceae) roots and leaves under controlled conditions. Plants were subjected to four treatments of copper concentrations of 1, 3 and 5 μg.mL-1, with a control treatment of 0 μg.mL-1, and evaluated at seven-day intervals over 21 days. Copper concentration in biomass was analysed by atomic absorption spectroscopy with flame atomisation. The results showed that copper concentration in the growth medium and time of exposure had a significant effect on the amount of copper accumulated by E. crassipes roots and leaves, with roots more efficient compared to leaves. It is likely that E. crassipes has mechanisms for the translocation of metal from the root system to the leaves. Symptoms of copper toxicity were observed in the vegetative parts of the plants at the end of the experiments. This study demonstrates that E. crassipes presents great potential in the absorption and accumulation of copper under laboratory conditions, indicating its effectiveness for applications in phytoremediation processes.

Keywords

• bioaccumulation, aquatic macrophytes, heavy metals, water resources