Lead is present in different types of industrial effluents, being responsible for environmental pollution. Biosorption has attracted the attention in recent years as an alternative to conventional methods for heavy metal removal from water and wastewater. The biosorption of Pb(II) ions present in the storage battery industry wastewaters intensively, by Rhizopus arrhizus has been investigated in this study. This microorganism has been preferred since its biosorption feature was well known. A detailed study was conducted for the removal of Pb(H) ions which was very toxic even in low quantities to the receiving environment, from storage battery industry wastewater by biosorption system as advanced treatment technique, and to investigate the effects of the several parameters on its removal. The average Pb(H) ions concentration in the storage battery industry wastewater found 3.0mg/L and reducing this value below 0.5 mg/L was aimed. In this study, the effects of the media conditions (pH, temperature, biomass concentration) on the biosorption of Pb(H) ions to R. arrhizus have been investigated in a batch reactor. Optimum biosorption conditions have been found of initial pH 4.5, temperature 30 degrees C and biomass concentration 1.0 g/L. The maximum biosorption capacity was obtained as 2.643 mg Pb(II)/g microorganism. (c) 2007 Elsevier Inc. All rights reserved.