In this paper, the effects of three coexisting ion systems (Cs, Sr), (Cr, Sr) and (Cs, Cr, Sr) on the adsorption of Sr(II) by irradiated Saccharomyces cerevisiae in solution were investigated. The three systems generally inhibited the adsorption of Sr(II) by yeast. The effects of several environmental factors on yeast adsorption of Sr(II) in coexisting ionic solutions were determined. Three adsorption models, Langmuir, Freundlich and Linear, were used to fit the experimental data. FTIR results showed that the mechanism by which Cs(I) and Cr(III) inhibited the adsorption of Sr(II) was related to the functional groups on the cell wall. [ABSTRACT FROM AUTHOR]