Use of a mathematical model for prediction of the performance of the simultaneous biosorption of Cr(VI) and Fe(III) on Rhizopus arrhizus in a semi-batch reactor

The simultaneous biosorption of Cr(VI) and Fe(III) ions in single component and binary systems has been studied using Rhizopus arrhizus, a filamentous fungus, in a semi-batch reactor. The mono-component equilibrium data have been analysed using the Langmuir model. For the prediction of the performan ce of the reactor for mono- and bicomponent biosorption of Cr(VI) and Fe(II I) ions, a mathematical model based on mass balances for liquid and solid p hases has been used. The forward and backward rate constants, K-1 and K-2, have been calculated in the case of single metal biosorption and then used for modelling of the multi-component biosorption in the semi-batch reactor. The proposed model was shown to correlate well with single and bicomponent adsorption data. The capacity of Cr(VI) in the binary systems is greater t han that of Fe(III), in agreement with the single component data. (C) 2001 Elsevier Science B.V. All rights reserved.