Acta Universitatis Sapientiae Agriculture and Environment, 1 (2009) 20-30 20 Cadmium biosorption on native Saccharomyces cerevisiae cells in aqueous suspension Katalin T`LOS 1 , Csilla P`GER 1 , Szende TONK 2 , Cornelia MAJDIK 2 , BØla KOCSIS 3 , Ferenc KIL`R 1 , Tmea PERNYESZI 1 1 Department of Analytical and Environmetal Chemistry, Faculty of Science, University of PØcs, 6 IfjœsÆg, H-7624 PØcs, Hungary, e-mail: ptimea@ttk.pte.hu 2 University Babe -Bolyai; Faculty of Chemistry and Chemical Engineering, 11 Arany J., RO-400293 Cluj-Napoca, Romania 3 Department of Medical Microbiology and Immunology, Faculty of Medicine, University of PØcs, 12 Szigeti, H-7624 PØcs, Hungary Manuscript received 24.08. 2009; revised 20.09. 2009, accepted; 22.09.2009 Abstract: In the present study, sorption of cadmium (II) ions from aqueous suspension on to native Saccharomyces cerevisiae cells of different origin was studied. Bakers yeast, waste yeast from brewery and cultivated yeast cells were used as biosorbents for cadmium removal in solution. The kinetics of cadmium biosorption by native Bakers yeast was investigated at different initial concentrations of the metal ion (5, 12.5, 25, 50 mg/L) at a pH 6. The adsorption equilibrium was reached within sixty minutes. The biosorption experiments were carried out at the natural state of pH 6 in the biomass suspensions using batch technique. Cadmium adsorption isotherms were determined on Bakers yeast at different sorbent dosages and yeast biomasses of different origin in the initial concentration range of 10 - 250 mg/L. The adsorption equilibrium of cadmium from aqueous solutions by yeast biomasses can be well described by Freundlich equation. The amount sorbed at equilibrium was found to be directly proportional to the initial metal ion concentration divided by the sorbent mass. Keywords: heavy metal, adsorption, Bakers yeast, cultivated yeast, waste yeast from brewery, isotherm, kinetics 1. Introduction Water pollution due to heavy metals is an issue of great environmental concern. Cadmium is one of the most toxic metals affecting the environment, which poses serious health hazards through entry into the food chain by anthropogenic pathways.