Dai Qun-Wei, Dong Fa-Qin, Zhang Wei
Key Laboratory of Solid Waste Treatment and the Resource Recycle (SWUST, Ministry of Education), Mianyang 621010, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2009 Jul;29(7):1788-92.
The biosorption of lead ions on dried waste beer yeast was investigated with respect to the adsorption conditions and the biosorption mechanism was analyzed with the instruments of AAS, SEM/EDS and FTIR. The results show that the metal uptake value obtained was 47.6 mg x g(-1) and the adsorptive efficiency was above 90%. Under our experiment conditions, the biosorption of Pb2+ on dried waste beer yeast is a fast process. The biosroption quantity of Pb2+ on beer yeast cells was 47.6 mg x g(-1) and the adsorption efficiency obtained was 91.6% in fisrt 30 min, then the metal uptake value obtained was 48.8 mg x g(-1) and the adsorptive efficiency was above 94% at 90 min. The cells cracking and breaking off were seen after the biosorption of lead ions on beer yeast through SEM analysis, and the cytoplasts from yeast cell should be responsible for the last period biosorption of lead ions. EDS analysis also proved that lead ions were absorbed on the yeast cells. FTIR analysis showed that the infrared spectrograms are different at different pH and biosorption time, especially hydroxyl groups, carboxylate groups and amide groups have obviously changed. Amylase and amide of protein were considered as main components to participate the chemical absorption of lead ions on yeast cells. Consequently, dried waste beer yeast is an inexpensive, readily available adsorbent for metals and especially has a high adsorption capacity for lead ions.
研究了干燥废啤酒酵母对铅离子的生物吸附，考察了吸附条件，并采用原子吸收光谱法（AAS）、扫描电子显微镜/能谱仪（SEM/EDS）和傅里叶变换红外光谱仪（FTIR）分析了生物吸附机理。结果表明，获得的金属吸附量为47.6 mg·g⁻¹，吸附效率高于90%。在实验条件下，Pb²⁺在干燥废啤酒酵母上的生物吸附是一个快速过程。啤酒酵母细胞对Pb²⁺的生物吸附量在最初30分钟为47.6 mg·g⁻¹，吸附效率为91.6%，90分钟时获得的金属吸附量为48.8 mg·g⁻¹，吸附效率高于94%。通过扫描电子显微镜分析发现，铅离子在啤酒酵母上生物吸附后细胞出现破裂和脱落，酵母细胞的细胞质应负责铅离子后期的生物吸附。能谱分析也证明铅离子被吸附在酵母细胞上。傅里叶变换红外光谱分析表明，不同pH值和生物吸附时间下的红外光谱图不同，尤其是羟基、羧基和酰胺基有明显变化。蛋白质中的淀粉酶和酰胺被认为是参与酵母细胞对铅离子化学吸附的主要成分。因此，干燥废啤酒酵母是一种廉价、易得的金属吸附剂，尤其对铅离子具有较高的吸附容量。
