50 REMOVAL OF CHROMİUM, LEAD AND COPPER IONS FROM INDUSTRIAL WASTE WATERS BY Staphylococcus saprophyticus Semra Ilhan 1* , Macit Nurbaş Nourbakhsh 2 , Serpil Kiliçarslan 2 and Huseyin Ozdag 3 1 Department of Biology, Osmangazi University, 26480 Eskisehir, Turkey 2 Department of Chemical Engineering, Osmangazi University, 26480 Eskisehir, Turkey 3 Department of Mining Engineering, Osmangazi University, 26480 Eskisehir, Turkey ABSTRACT In this study, selective biosorption of chromium, lead and copper ions by microorganisms from industrial wastewaters were investigated. Microorganisms were isolated from soil and in this research a bacterium which was identified as Staphylococcus saprophyticus was used. The effects of pH, temperature and initial concentration of metal ions on the biosorption capacity were investigated. The optimum pH values for chromium, lead and copper biosorption was found to be 2.0, 4.5 and 3.5 respectively. The maximum adsorption was observed for Cr 6+, Pb 2+ and Cu 2+, at the initial concentrations of 193.66 mg Cr 6+ /l; 100 mg Pb 2+ /l and 105 mg Cu 2+ /l and under these conditions the biosorption values were found to be 88.66 mg Cr 6+ /l; 100 mg Pb 2+ /l and 44.94 mg Cu 2+ /l, respectively. The results indicated that S. saprophyticus was suitable for biosorption of lead and chromium from wastewaters. Key words: Biosorption, adsorption, heavy metals, industrial wastewaters Staphylococcus saprophyticus. *Corresponding author. Tel.: +90 222 2290433/2419 fax: +90 222 2393578 E-mail address: silhan@ogu.edu.tr INTRODUCTION Metals are directly and/or indirectly involved in all aspects of microbial growth, metabolism and differentiation. Many metals such as K, Na, Mg, Ca, Mn, Fe, Cu, Ni, Co, Zn, Mo are essential for biological functions, whereas it is not known whether some others, such as Al, Ag, Cd, Sn, Au, Sr, Hg, Tl and Pb have essential biological functions. All these elements can interact with microbial cells and be accumulated as a result of physico-chemical mechanisms and transport systems of varying specificity, independent on, or directly and indirectly dependent on metabolism (Gadd, 1988). Some of these processes are of biotechnological importance being relevant to metal removal and recovery from mineral deposits and industrial effluents for industrial use or environmental bioremediation. Turkish Electronic Journal of Biotechnology Vol 2, p:50-57, 2004 © Biotechnology Association