Study on Pyrolytic Characteristics of Dead Yeast Powder and Biosorption Mechanism on Cu²+

Pyrolysis process of dead beer yeast powder was studied through thermogravimetric analyzer. Cu²⁺ adsorption mechanism was analysed by SEM and FTIR. The results showed: in thermogravimetric test, TG and DTG figures indicated five pyrolytic stages, weight losting in the third(247degC- 309degC) and fourth(309degC-420degC) stages, most important stages, accounted for 68.3% of total weight losting and 50.5% of total sample weight. SEM figures indicated that before adsorption on Cu²⁺, the cell surface of yeast powder and immobilized yeast were smooth, but after adsorption, many "spots" and something like spininess deposition appeared on cell surface, inorganic- precipitation mechanism and redox mechanism might work in the process. After adsorption, FTIR figures changed little, the main structure and components of yeast kept unchanged, -OH -. -CONH₂ and -COOH all played an important role in adsorption process.