The Biosorption Effect and Mechanism of Pb(II) on Waste Beer Yeast

The biosorption of Pb(II) ions on dried wasted beer yeast was investigated with respect to the adsorption conditions. The results of this study indicated that different variables, such as contact time, adsorbent dose, solution pH and initial heavy metal ions concentration influenced the adsorptive quantity. The best adsorption parameters and quantitative analysis of Pb²⁺ by dried waste beer yeast revealed that at optimum conditions (pH = 4.5; Pb²⁺ initial concentration = 1.0 mmol/L; biomass dose = 4.0 g/L; contact time = 90 min), the highest metal uptake values obtained above 60 mg/g and the adsorptive efficiency was above 93%. The SEM analysis showed that the interactions between Pb(II) ions and functional groups on the cell wall surface of dried waste beer yeast. Consequently, dried waste beer yeast is an inexpensive, readily available adsorbent for metals and especially has a high adsorption capacity for Pb(II) ions.