Characterization and evaluation of seaweed-based sorbents for treating toxic metal-bearing solutions

Marine algal varieties Ascophyllum nodosum, Lessonia flavicans, Laminaria h yperborea and Durvillea potatorum as well as processed seaweed residues ari sing from the algin extraction industry have been evaluated for toxic metal sorption. Biosorption isotherms have been obtained for copper, cadmium and nickel at controlled solution pH4. Potentiometric titrations and esterific ation of algal biomass indicate that carboxylate groups are: primarily resp onsible for metal sorption. Proton/metal interactions play an important rol e in the biosorption process. Swelling of biosorbents is discussed in the c ontext of potential large-scale fixed-bed column applications.