Kinetics and equilibrium studies on removal of zinc(II) by untreated and anionic surfactant treated dead biomass of yeast: Batch and column mode

The present study was carried out using dead biomass of isolated yeast species viz. Candida rugosa and Candida laurentii as biosorbents for the removal of Zn(II) from aqueous environment. C. rugosa and C. laurentii exhibited 65.4% and 54.8% removal of zinc at pH 6.0 in presence of 90 mg L-1 Zn(II) at 30 degrees C in batch system. Remarkable increase in Zn(II) removal was noted using dead yeast biomass treated with anionic surfactant sodium dodecyl sulphate (SDS) which was confirmed through SEM analysis. Kinetic studies based on various models were carried out and the results showed a very good compliance with the fractional power model. The experimental data were analyzed using two, three and four parameter isotherm models. The most appropriate equation for describing the isotherm profile was Freundlich model. The biosorbent performance was evaluated in column mode packed with SOS treated dead biomass of C. rugosa entrapped in sodium alginate beads. FT-IR analysis showed the involvement of -NH, -C=O and -COOH functional groups in the binding of Zn(11) by yeast. The present study confirmed that immobilized SDS treated dead biomass of C. rugosa may serve as potential and eco-friendly biosorbent for removal of Zn(II) ions from aqueous solution. (C) 2012 Elsevier B.V. All rights reserved.