Biosorption of iron(III)-cyanide complex anions to Rhizopus arrhizus: application of adsorption isotherms

The biosorption of iron(III)-cyanide complex anions to Rhizopus arrhizus wa s investigated. The iron(III)-cyanide complex ion binding capacity of the b iosorbent was a function of initial pH, initial iron(III)-cyanide complex i on and biosorbent concentration. These results indicated that a significant reduction of iron(III)-cyanide complex ions was achieved at pH 13, a highl y alkaline condition. The maximum loading capacity of biosorbent was 612.2 mg g(-1) at 1996.2 mg litre(-1) initial iron(III)-cyanide complex ion conce ntration at this pH. The Freundlich, Langmuir and Redlich-Peterson adsorpti on models were fitted to the equilibrium data at pH 3.0, 7.0 and 13.0. The equilibrium data could be best fitted to by all the adsorption models over the entire concentration range (50-2000 mg litre(-1)) at pH 13. (C) 1999 El sevier Science Ltd. All rights reserved.