Cadmium (II) ion and nickel (II) ion biosorption on yeast: Application of equilibrium model

Abstract

Experimental data on cadmium (II) and nickel (II) ion sorption on deactivated protonated yeast over a wide range of sorbent and initial metal concentrations, were analyzed by an equilibrium model based on a thermodynamics approach. Model describes relationships between the equilibrium concentration of metal, metal sorption per unit biomass dosage and concentration of sorbent and initial metal concentrations at constant pH and temperature. It is not found possible to reasonably fit the sorption data for cadmium (II) and nickel (II) ion on deactivated protonated yeast, to a unique isotherm curve when both initial metal ion concentration and biomass concentration are varied at a particular pH. Model fits the data well for the sorption of nickel (II) ion onto deactivated protonated yeast at pH 6.75. However, model could be applied only for a given substrate concentration for sorption of cadmium (II) ion onto sodium form of deactivated protonated yeast at pH 6.5.<b style=""></b>