Accumulation of copper by the aquatic macrophyte Salvinia biloba Raddi (Salviniaceae)

Abstract

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.

Variations in the Phytoremediation Efficiency of Metal-polluted Water with Salvinia biloba: Prospects and Toxicological Impacts

“…Selected S. biloba specimens were gently rinsed with deionized water and placed (10.0 g wet basis) in beaker glass (500 mL) with artificially-contaminated water at independently equal molar concentrations (50 ± 2 and 100 ± 1 µM) of Cd (5.6 ± 0.2 and 11.2 ± 0.1 mg/L), Cu (3.2 ± 0.1 and 6.4 ± 0.1 mg/L), Pb (10.4 ± 0.4 and 20.7 ± 0.2 mg/L) or Zn (3.3 ± 0.1 and 6.5 ± 0.1 mg/L). Metal concentrations were selected in accordance with previously reported data [12][13][14][15][16][17][18][19]. The experiments were carried out in controlled conditions at an average room temperature of 24 ± 2 • C under artificial light with a photon flux intensity of 50 µmol m −2 s −1 (Osram Dulux L HE, Munich, Germany) and 12 h photoperiod according to [18,19].…”

“…The Salvinia species most amply found in Argentina are S. auriculata Aubl., S. minima Baker, S. natans (L.) All., and S. biloba Raddi (synonym: S. herzogii de la Sota). Only a reduced number of studies have analyzed the capacity of S. biloba to phytoremediate water contaminated with heavy metals (e.g., Cd, Cr, Zn, Ni, Cu, and Pb) [12][13][14][15][16][17][18][19]. In general, most of them have focused on individual metals, at different concentrations [12,13,[17][18][19].…”

“…Only a reduced number of studies have analyzed the capacity of S. biloba to phytoremediate water contaminated with heavy metals (e.g., Cd, Cr, Zn, Ni, Cu, and Pb) [12][13][14][15][16][17][18][19]. In general, most of them have focused on individual metals, at different concentrations [12,13,[17][18][19]. To the best of our knowledge, only three of such works [14][15][16] have analyzed S. biloba metal-phytoremediation efficiency for two or more metals, but submitting plants to different metal molarity (i.e., the molar amount of cation ions at the sample solution was different between the analyzed metals), rendering comparisons between elements difficult to carry out.…”

A green approach for the treatment of dye and surfactant contaminated industrial wastewater

“…Recently, the development of inexpensive and environmentally friendly methods for the treatment of wastewater containing pollutants becomes important (Ramírez et al, 2018). Physical and chemical treatment methods are expensive but biological treatment is cost-effective and eco-friendly (Freitas et al, 2018). The use of biological materials as bacteria, fungi, yeast, and algae for removal of pollutants is defined as biological treatment.…”

Assessment of phytoremediation potencial of Allium cepa L. in raw sewage treatment

“…Phytoremediation provides huge environmental benefits at a cost lower than physicochemical methods. This area of study has gained momentum in the last ten years, with the discovery of the biotransformation capacity that plant roots have over exogenous organic molecules Baracuhy et al, 2015;Silva et al, 2015;Freitas et al, 2018).…”