Biosorption of mercury by Macrocystis pyrifera and Undaria pinnatifida: Influence of zinc, cadmium and nickel

JOSEFINA PLAZA, MARISA VIERA, EDGARDO DONATI, ERIC GUIBAL

JOURNAL OF ENVIRONMENTAL SCIENCES-CHINA

SCIENCE PRESS

Lugar: Editorial Elsevier; Año: 2011 vol. 23

1001-0742

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 biosorbents reach the same maximum sorption capacity (qm = 0.8 mmol/g) 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] . 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). Samples analysis using an environmental scanning electron microscopy equipped with an energy dispersive X-ray [.2] microanalysis showed that mercury was heterogeneously adsorbed at the surface of both biomaterials, while the other heavy metals were homogeneous distributed. The biosorbents were analyzed by Fourier transform infrared spectrometry[.3] : Hg(II) binding occurs on S=O (sulfonate) and N--H (amine) functional groups.