Aquatic macrophytes have properties and mechanisms which are useful for the removal of substances in solution, commonly used in phytoremediation processes in aquatic environments. This study evaluated the performance of copper (Cu) accumulation by Salvinia biloba Raddi (Salviniaceae) in different metal concentrations (1, 3 and 5 µg mL -1 ), as well as the control treatment, measured at intervals of 0, 7 and 14 days under laboratory conditions, with control as to pH and luminosity. After the experiment, the S. biloba biomass was washed, kiln dried, crushed and subjected to the process of digestion, and subsequently the accumulated copper content was determined by atomic absorption spectroscopy. The results showed that S. biloba is apt at accumulating copper, varying significantly between different treatments and days of exposure to the contaminant, as well as its interaction (treatment × days). The highest accumulation values were observed in treatment with 5 µg mL -1 , which at 14 days, with 11,861 µg g-1 of copper. We observed symptoms of toxicity and mortality in plants, probably indicating the effect of copper on the species when at high levels. Salvinia biloba is an efficient species in the removal of copper in solution, its recommendation as a remediating agent in aquatic ecosystems being possible.Keywords: aquatic ecosystems, phytoremediation, aquatic plants, bioaccumulation, water resources.Acumulação de cobre pela macrófita aquática Salvinia biloba Raddi (Salviniaceae) ResumoMacrófitas aquáticas apresentam propriedades e mecanismos úteis à remoção de substâncias presentes em solução, comumente, utilizadas em processos de fitorremediação de ambientes aquáticos. Este estudo avaliou o desempenho de acumulação de cobre (Cu) por Salvinia biloba Raddi (Salviniaceae) em diferentes concentrações do metal (1, 3 e 5 µg mL), além do tratamento controle, avaliados em intervalos de 0, 7 e 14 dias, sob condições laboratoriais, com controle de pH e luminosidade. Após o experimento a biomassa de S. biloba, foi lavada, seca em estufa, triturada e submetida ao processo de digestão, sendo, posteriormente, o teor de cobre acumulado determinado por espectroscopia de absorção atômica. Os resultados evidenciaram que S. biloba é hábil em acumular cobre em sua biomassa, variando significativamente entre os diferentes tratamentos e dias de exposição ao contaminante, bem como por sua interação (tratamentos × dias). Os maiores teores de acúmulo foram observados no tratamento com 5 µg mL -1 , que aos 14 dias apresentou até 11.861 µg g -1 de Cu. Observamos sintomas de toxicidade e mortalidade nas plantas, evidenciando, provavelmente, o efeito do cobre sobre a espécie quando em elevados níveis. Salvinia biloba é uma espécie eficiente na remoção do cobre em solução, sendo possível sua recomendação como agente de remediação em ecossistemas aquáticos.Palavras-chave: ecossistemas aquáticos, fitorremediação, plantas aquáticas, bioacumulação, recursos hídricos. Freitas, F. et al.

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.

Aquatic plants are often exposed to metal contamination. The study evaluated the bioaccumulation of copper (Cu) ions in aqueous solution by the biomass of leaves and roots of the macrophyte Salvinia natans. Plants of S. natans were submitted to culture solutions with different concentrations of Cu ions, evaluated at intervals of seven days. The leaf and root samples were separately subjected to atomic absorption spectroscopy with flame atomization to assess the concentration of copper accumulated in its biomass. The results demonstrated a pattern of accumulation dependent on the concentration of the metal in the culture medium and the time of exposure of the plants to the contamination. The accumulation was greater in the biomass of the roots when compared to the leaves. Throughout the experiment, toxicity symptoms were observed in the morphology of plants subjected to all copper concentrations, demonstrating the macrophyte's viability for bioindicating the toxicity of this metal in aquatic environments. A high accumulation of copper ions was obtained both in the biomass of the roots and leaves of the plants, confirming their potential bioaccumulator of Cu. The analysis of biomass suggests an important characteristic of metal compartmentalization by the plant, associating the absorption by the roots and the possible transfer to the leaves. In general, our results show that S. natans is an organism with a potential bioindicator and bioaccumulator of Cu and consists of a viable cost-effective option for phytoremediation of aquatic environments contaminated by metals