Adsorptive-desorptive performance of Chlorellavulgaris for the removal of vanadium from aqueous solutions.

Studies on Vanadium (V) adsorption in aqueous systems employing biomaterials friendly to the environment are rare. This study investigated the adsorption performance of the living and non-living Chlorella vulgaris (C. vulgaris) for V from aquatic systems. Vanadium inhibited the growth of living C. vulgaris. The results of isothermal equations showed that the non-living C. vulgaris biomass was favourable for V adsorption. At 400 mg L−1 V, 50 mg algae biomass, 40°C, and 0.01 M ionic strength for 24 h, the maximum adsorption capacity reached 94.00 mg g−1. The results of the kinetic studies indicated that chemisorption dominated the V adsorption process. Analysis on the surface of non-living C. vulgaris biomass revealed that hydroxyl groups, carboxylate groups, amide groups, aromatic carbons, and organic halogenated hydrocarbon groups played crucial roles in V biosorption. Vanadium was bound to the active sites on the surface of C. vulgaris through ion exchange action as opposed to redox reaction. Desorption experiments were conducted by eluting the non-living C. vulgaris biomass with 1 M NaOH solution, and the maximum desorption rate of V reached 98%. The results demonstrate that C. vulgaris is a green and highly effective biosorbent for vanadium removal from aquatic systems. [ABSTRACT FROM AUTHOR]