Equilibrium, kinetics and thermodynamics study on biosorption of Cr(VI) by fresh biomass of Saccharomyces cerevisiae

The low cost fresh biomass of Saccharomyces cerevisiae ( S. cerevisiae ) was utilized for removal of Chromium ion from aqueous solution. The maximum biosorption was found to occur at pH 1.0. The biosorption capacity of S. cerevisiae was found to be 3.89 mg/g for a solution with initial Cr(VI) concentration of 50 mg/L at 35 °C. Several biosorption isotherms were used to fit the equilibrium data, indicating biosorption relied mainly on physical adsorption onto heterogeneous surface. Kinetic models were evaluated and we found that pseudo-second-order rate kinetic model showed better correlation, and the biosorption of Cr(VI) was governed by film diffusion as well as intraparticle diffusion. Thermodynamic constants indicated that the biosorption was spontaneous and endothermic. Fourier transform infra-red (FTIR) spectroscopy was used to reveal the main function groups of biosorption, which were hydroxyl, amine groups, C-H of the alkanes, C=O and S=O.