Response surface methodology for cadmium biosorption on Pseudomonas aeruginosa

Abstract

In this research the effects of various physicochemical factors on Cd2 biosorption such as initial metal concentration, pH and contact exposure time were studied. This study has shown a Cd2 biosorption, equilibrium time of about 5 min for Pseudomonas aeruginosa and the adsorption equilibrium data were well described by Langmuir equation. The maximum capacity for biosorption has been extrapolated to 0.56 mmol.g for P. aeruginosa. The thermodynamic properties G0, H0, and S0 of Cd2 for biosorption were analyzed by the equilibrium constant value obtained from experimented data at different temperatures. The results show that biosorption of Cd2 by P. aeruginosa are endothermic and spontaneous with H value of 36.35 J.mol-1. By response surface methodology, the quadratic model has adequately described the experimental data based on the adjusted determination coefficient (R2 0.98). The optimum conditions for maximum uptake onto the biosorbent were established at 0.5 g.l1 biosorbent concentration, pH 6 for the aqueous solution, and a temperature of 30 WC.