Statistical Optimization of Process Parameters for Cr (VI) Biosorption onto Mixed Cultures of Pseudomonas aeruginosa and Bacillus Subtilis

Abstract

In the present study, response surface methodology (RSM) was employed to investigate the effects of different operating conditions on the removal of hexavalent chromium (Cr (VI)) onto mixed cultures of Pseudomonas aeruginosa and Bacillus subtilis (MCOPAABS)using biosorption processes. Box-Behnken design (BBD) was used for optimization of the biosorption process and to evaluate the effects and interactions of the process variables, i. e., biomass concentration, pH, temperature and contact time on the removal of Cr (VI). A synthetic aqueous solution with a Cr (VI) concentration of 10 mg/L was used in the experimental study as a fixed input variable. The optimum conditions for maximum uptake (1.44 mg/g) of Cr (VI) onto the biosorbent were established as 0.5 g/L biosorbent dosage, pH 2 for the aqueous solution, 328C temperature and 23 min contact time.