Biosorption of Cu(II) Ions by Kelps, Large Brown Algae Seaweeds, Saccharina japonica and Saccharina sculpera

Abstract

The adsorption experiments of two kinds of kelps, large brown algae seaweeds, Saccharina japonica and Saccharina sculpera, have been carried out for the aqueous solution Cu2+ ions. A copper uptake of around 0.3 mmol per gram of kelp powder with particle size under 250 μm was observed for the former brown algae at the equilibrium copper concentration of 19 mg/L. It was found that further increase in the copper concentration gave rise to the increase in the metal uptake, reaching 1.9 mmol/g kelp at 47 mg/L. This increase was presumably due to the diffusion of the ion through the gel, formed at the initial stage of the adsorption, into the inner alginates of the kelp. Titration measurements allowed us to gain a quantitative understanding of the apparent surface concentration of the adsorption sites as well as the adsorption capacity.