Characterization and Evaluation of Copper and Nickel Biosorption on Acidic Algae Sargassum Filipendula

International audienceThe marine algae Sargassum filipendula was collected from São Paulo seashore (Brazil) and submitted to treatment with acid. The biosorption mechanisms of Cu 2+ and Ni 2+ ions onto acidic algae Sargassum filipendula were examined using various analytical techniques: Fourier-transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and potentiometric titration (pH ZPC). The effect of acidic treatment on algae by hydrochloric acid (pH 2.0, 3.0, 4.0 and 5.0) was evaluated for Cu 2+ and Ni 2+ adsorption. Alginate was extracted from raw algae and the two types of acids present in the biomass (β-D-mannuronic (M) and α-L-guluronic (G) acid) were characterized by 13 C NMR. The M/G ratio was found to be 0.50. According to the pH ZPC analysis, at a pH higher than 5.5 the acidified algae surface presents a negative charge. The FT-IR analyses showed that the main chemical groups involved in the biosorption were carboxylic, alcoholic, sulfonate and amino groups