Biosorption of strontium(II) from aqueous solutions by Bacillus cereus isolated from strontium hyperaccumulator Andropogon gayanus

The biosorption of strontium(II) from aqueous solutions using dead bacteria biomass was investigated in this study. Phylogenetic analysis based on 16S rDNA sequence demonstrates that the isolated strain belonged to Bacillus cereus. The bacteria exhibited the highest strontium sorption capacity at an initial pH of 5.0, contact time of 50 min, biomass dosage of 3.0 g L−1 and agitation speed of 120 rpm. The adsorption profile was better matched by Langmuir than Freundlich model. The maximum biosorption capacity obtained by Langmuir model was 58.79 mg g−1. Adsorption kinetics indicate that the pseudo-second order model was appropriate to describe the biosorption process. Fourier transform infrared (FT-IR) spectroscopy analysis indicates that the main functional groups responsible for biosorption of strontium(II) were hydroxyl, carboxyl and amino. The isolated bacteria B. cereus can be a great potential biosorbent to remove strontium ions from aqueous solutions.