Copper biosorption by Cystoseira crinitophylla dry biomass was studied in a batch sorption experiment as well as a continuous regenerable column configuration. The algal biomass showed a very high adsorption capacity of 160 mg g(-1) at 600 mg l(-1) equilibrium concentration at pH 4.5. Sorption isotherms were fitted with the Langmuir and Freundlich model equations showing very good agreement with the data. Flowthrough experiments were performed in a column containing Cystoseira protonated dry biomass. The data were fitted with the Thomas and Clark models for heterogenous ion exchange and the role of pH, flow rate, bed height and feed concentration was investigated. Regeneration studies of the column showed 100% efficiency even after 35 sorption/desorption cycles at pH 4.5 and 96% for pH 2.6. (C) 2015 Elsevier B.V. All rights reserved.