Biosorption of copper and zinc by the residual biomass of the alga Sargassum sp. was investigated in a mini packed-bed column. The biomass was immobilized in a polymeric matrix to improve its physicochemical properties for continuous biosorption of heavy metals from aqueous solutions. Adsorption breakthrough curves obtained at different flow rates indicated that an increase in flow rate decreased the volume treated until the breakthrough point as well as the service time of the bed acid the dynamic capacity of the column. At the lowest flow rate of 1.0 ml/min per cm(2) it was possible to treat 446 and 414 bed volumes of copper and zinc up to their respective breakthrough points. At this flow rate, the dynamic capacity of the column was 11.9 mg Cu/g and 21.0 mg Zn/g.