Batch zinc biosorption by a bacterial nonliving Streptomyces rimosus biomass

The zinc biosorption capacity of a Streptomyces rimosus biomass was studied in the batch mode. After a heat pretreatment, optimum conditions of biosorption were found to be: an average saturation contact time of 4 h, a biomass particle size between 140 and 250 mu m, the ambient temperature, a stirring speed of 250 rpm, and pH of 7.5. The equilibrium data could be fitted by a Langmuir isotherm equation. Under these optimal conditions, up to 30 mg(Zn)/g(biomass), was fixed. Moreover, additional chemical treatment of the biomass by NaOH (1 mol/L), increased the biosorption Capacity of about 80 mg(Zn)/g(biomass). (C) 1999 Elsevier Science Ltd. All rights reserved.