Journal des bioprocédés et des biotechniques

Biosorption of Co(II) by Schizosaccharomyces pombe: Kinetic and Thermodynamic Studies for Process Design

Abstract

Ahmet Alp Sayar, Nihat Alpagu Sayar, Selcen Durmaz-Sam, Gizay Odabasi

The characterisation of biosorption by Schizosaccharomyces pombe of Co(II) was done under varying experimental conditions including pH, temperature, initial metal concentration and biosorbent dose. Optimum pH was found to be 5.0 with optimal biosorbent dose for highest adsorption capacity at 1.0 g L^-1. Higher initial metal concentrations helped enhance q_e slightly with the highest value, 2.7 mg g^-1, being achieved at 25°C and 50 mg L^-1 initial Co(II). Temkin isotherm model showed the best statistical fit for equilibrium data while Freundlich isotherm model exhibited thermodynamic consistency. Pseudo-first order kinetics was found to represent Co(II) biosorption. Increasing ΔG⁰ values calculated with respect to higher operational temperatures were in agreement with kinetic profiling simulations whereby higher temperatures were found to be less favourable. Overall efficiency of S. pombe as a biosorbent for Co(II) was found to be significantly less than Ni(II), for this reason it can be regarded as a potential bioseparation agent for aqueous mixtures containing both Co(II) and Ni(II).