BACKGROUND: The alginate extraction residue from Brazilian Sargassum filipendula was employed as biosorbent for Zn(II) removal through a fixed-bed column in order to explore its adsorptive properties and to establish a new use for this waste. RESULTS: The best operating conditions were 0.5 mL min(-1) and 1.0 mmol L-1 (inlet concentration), providing lower mass transfer zone and higher uptake. Elution percentages of 52 and 73% were obtained for the first and second desorption cycles, respectively, using CaCl2 as eluent. The Yan et al. model was more representative of the experimental data. Characterization revealed that ion exchange is involved between zinc ions and light metals (Ca, Na, K and Mg). A decrease was observed in real and apparent densities of biomass, with an increase in particle porosity of the residue after process. CONCLUSION: The study revealed that this biomass has potential for Zn removal from aqueous solution, encouraging its application as a biosorbent in future studies involving multicomponent systems. (C) 2017 Society of Chemical Industry