Biosorption of mercury by Macrocystis pyrifera and Undaria pinnatífida. Influence of zinc, cadmium and nickel

PLAZA CAZÓN JOSEFINA ; MARISA VIERA; EDGARDO DONATI; ERIC GUIBAL

JOURNAL OF ENVIRONMENTAL SCIENCES-CHINA

SCIENCE PRESS

Año: 2011 vol. 23 p. 1778 - 1786

1001-0742

Abstract: This study investigates the adsorption of Hg(II) on Macrocystis pyrifera and Undaria pinnatifida in monometallic system and in the presence of Zn(II), Cd(II) and Ni(II). The two biosorbent reach the same maximum sorption capacity (qm=0.8 mmol.g-1) for mercury. U. pinnatifida shows a greater affinity (given by the b coefficient of the Langmuir equation) for mercury compared to M. pyrifera (4.4 versus 2.7 L mmol-1 respectively). Mercury uptake was significantly reduced (by more than 50 %) in the presence of competitor heavy metals such as Zn(II), Cd(II) and Ni(II). Mercury was heterogeneously sorbed at the surface of both M. pyrifera and U. pinnatifida, while the other heavy metals were homogeneous distributed (SEM-EDX characterization). The biosorbents were analyzed by FT- IR spectrometry: S=O (sulfonate) and N-H (amine) functional groups, were identified as the main responsible of Hg(II) binding.