The simultaneous biosorption of Cu(II) and Zn on Rhizopus arrhizus: application of the adsorption models

The biosorption of two divalent metal ions-copper(II) and zinc-in single co mponent and binary systems has been studied using Rhizopus arrhizus. The mo nocomponent equilibrium data have been analysed using the Langmuir, the Fre undlich and the three parameter Redlich-Peterson isotherms. The non-competi tive Freundlich isotherms have been found to have the highest regression co rrelation coefficients and the minimum average percentage errors between th e predicted and the experimental values. The effects of the presence of Cu( II) and Zn ions together on the biosorption of Cu(II) and Zn ions have been investigated in terms of initial rates of biosorption and equilibrium isot herms. The competitive Freundlich model has also been demonstrated to provi de the best correlation for the biosorption of the two metal ions on R, arr hizus. (C) 1998 Published by Elsevier Science B.V. All rights reserved.