Investigation of uranium biosorption from aqueous solutions by Dictyopteris polypodioides brown algae

The biosorption of uranium from aqueous solutions by Dictyopteris polypodioides brown algae was investigated. The effect of pH, uranium concentration, mass of the adsorbent, temperature and contact time on the removal efficiency were studied and the results were simulated by Langmuir, Freundlich and Dubinin-Radushkevich isotherm models. Kinetics data could be satisfactorily reproduced by the pseudo-second order equation and thermodynamic parameters were determined in order to evaluate the uranium uptake behavior. SEM/EDS and FTIR were additionally used to characterize the algae and comprehend the sorption process which can be described as a combination of several mechanisms, including physical sorption, ion exchange and complexation.