Biosorption of Strontium Ions in Aqueous Solution by Beer Yeast

The biosorption of strontium ions on beer yeast was investigated under the different adsorption conditions. The results of this study showed that the beer yeast has some abilities to adsorb Sr(II) from solution. Different variables, such as solution pH, contact time, adsorbent dose and initial strontium ions concentration influenced the adsorptive quantity. The process of biosorption has nearly reached equilibrium within 30 min and the optimum pH is near 4.5. Increasing the initial concentration of Sr(II) and biosorbent dosage results in higher adsorptive quantity. The SEM analysis showed that the interactions were between Sr(II) ions and functional groups on the cell wall surface of waste beer yeast. Consequently, waste beer yeast is an inexpensive, readily available adsorbent for strontium ions.