Characteristics of Zn2+ biosorption by Saccharomyces cerevisiae.

OBJECTIVE: To investigate the characteristics of Zn2+ biosorption and the release of cations during the process of Zn2+ biosorption by intact cells of Saccharomyces cerevisiae. METHODS: The batch adsorption test was used to study the biosorption equilibrium and isotherm. Zn2+ concentration was measured with atomic adsorption spectrophotometer (AAS) AAS 6 Vario. RESULTS: When the initial concentration of Zn2+ ranged between 0.08 and 0.8 mmol/L, the initial pH was natural (about 5.65), the sorbent concentration was about 1 g/L and the capacity of Zn2+ biosorption was from 74.8 to 654.8 micromol/g. The pH value increased by 0.55-1.28 and the intracellular cations (K+, Mg2+, Na+, Ca2+) of the cells were released during the process of Zn2+ biosorption. CONCLUSION: Ion exchange was one of the mechanisms for Zn2+ biosorption. The biomass of Saccharomyces cerevisiae is a potential biosorbent for the removal of Zn2+ from aqueous solution. More work needs to be done before putting it into practical application.