The main goal of this paper was to elaborate the possibility of industrial application of biosorption properties of Enteromorpha prolifera (production of mineral feed additives for livestock). In this study, biosorption process was used in the binding of chromium(III) ions from aqueous solution by the green macroalga. The kinetics of biosorption process was studied in a batch system with respect to the initial pH, temperature, initial metal ion concentration, and initial biomass concentration. E. prolifera demonstrated good biosorption properties. The equilibrium biosorption capacity increased with pH and with initial concentration of metal ions. The uptake of chromium(III) ions by the dried alga was affected by the temperature, but in small extent. With increase of the biomass concentration, the decrease of biosorption capacity at equilibrium was observed. The best biosorption conditions were determined as the initial pH 5, temperature 25 degrees Celsius, the initial chromium(III) ions concentration 400 mg/L, and biosorbent concentration 1.0 g/L. Biosorption capacity at equilibrium reached at these conditions was 100 mg/g. The mechanism of the biosorption of chromium(III) ions by E. prolifera was analyzed in equilibrium experiments. Equilibrium data were fitted to Langmuir, Dubinin-Radushkevich, and Freundlich adsorption isotherms. The most suitable model for describing the obtained data was Langmuir model. The experimental results and the analysis of the solution before and after biosorption process suggested ion-exchange mechanism.