Biosorption of Cr(III) and Cr(VI) onto the cell surface of Pseudomonas aeruginosa

Biosorption of the chromium ions Cr(III) and Cr(VI) onto the cell surface of Pseudomonas aeruginosa was investigated. Batch experiments were conducted with various initial concentrations of chromium ions to obtain the sorption capacity and isotherms. It was found that the sorption isotherms of P aeruginosa for Cr(III) were described well by Langmuir isotherm models, while Cr(VI) appeared to fit Freundlich models. The results of FT-IR analysis suggested that the chromium binding sites on the bacterial cell surface were most likely carboxyl and amine groups. The bacterial surface of P. aeruginosa seemed to engage in reductive and adsorptive reactions with respect to Cr(VI) biosorption. (c) 2006 Elsevier B.V. All rights reserved.