Biosorption of Mercury(II) with Different Marine Algae

Five species of algae (Lessonia nigrescens Bory, Prionitis decipiens, Grateloupia doryphora, Lessonia trabeculata and Macrocystis integrifolia) collected from Peruvian coast have been tested for mercury recovery from synthetic solutions. Preliminary experiments showed that optimum sorption occurred at pH 6-7 and that Lessonia algae were the most efficient sorbents for Hg(II). The biomass was cross-linked with calcium chloride. Stabilized biosorbent showed sorption capacity as high as 267 mg g-1 at pH 6. The sorption isotherm was described by the Langmuir equation, while the pseudo-second order equation was used for modeling uptake kinetics. Salt addition strongly affected mercury sorption following the sequence: NaNO3 << Na2SO4 <<< NaCl.