Single and binary component sorption of the fission products Sr2+, Cs+ and Co2+ from aqueous solutions by sulphate reducing bacteria

Abstract

This study investigates the removal of the fission products Sr2+, Cs+ and Co2+ in single and binary metal solutions by a sulphate reducing bacteria (SRB) biomass. The effect of initial concentration and pH on the sorption kinetics of each metal was evaluated in single metal solutions. Binary component equilibrium sorption studies were performed to investigate the competitive binding behaviour of each metal in the presence of a secondary metal ion. Results obtained from single metal equilibrium sorption studies indicated that SRB have a higher binding capacity for Sr2+ (qmax = 416.7 mg g-1), followed by Cs+ (qmax = 238.1 mg g- 1), and lastly Co2+ (qmax = 204.1 mg g-1). Among the binary systems investigated, Co2+ uptake was the most sensitive, resulting in a 76% reduction of the sorption capacity (qmax) in the presence of Cs+. These findings are significant for future development of effective biological processes for radioactive waste management under realistic conditions.