A novel biosorbent was prepared and applied for the removal of uranium from aqueous solution. A new immobilization method was studied and used to embed living yeast cells of Saccharomyces cerevisiae (2% w/v) by sodium sulfate (0.5 mol/L) based on saturated boric acid-alginate calcium cross-linking method. The swelling ratio, hydraulic and chemical stability and bioactivity of immobilized microbial cells were examined. Their ultra-microstructure and property were observed by SEM, TEM and FTIR techniques. The influencing factors, such as contact time, initial uranium concentration, and initial pH were investigated. The adsorption capacity of biosorbent increased from 0.75 to 113.4 μmol/g when the equilibrium concentration of U was 0.9, and 43.9 μmol/L, respectively. U adsorption followed pseudo first-order kinetic model. SEM-EDS and TEM-EDS observation indicated that uranium was adsorbed both on the surface and the inner parts of the biosorbent. FTIR and the XPS results confirmed the role of oxygen in capturing uranium from aqueous solution. XPS analysis showed that the mixture of U (VI) and U (IV) existed on the surface of biosorbent, which evidenced that uranium was microbiologically reduced.

中文翻译：

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固定化酿酒酵母对铀的生物吸附。

制备了一种新型生物吸附剂，并用于从水溶液中去除铀。研究了一种新的固定化方法，并基于饱和硼酸-海藻酸钙交联法，用硫酸钠（0.5 mol / L）嵌入酿酒酵母（2％w / v）的活酵母细胞。检查了固定化微生物细胞的溶胀率，水力和化学稳定性以及生物活性。通过SEM，TEM和FTIR技术观察了它们的超微结构和性能。研究了影响时间的因素，如接触时间，初始铀浓度和初始pH。当U的平衡浓度为0.9和43.9μmol/ L时，生物吸附剂的吸附容量从0.75增加到113.4μmol/ g。U吸附遵循伪一级动力学模型。SEM-EDS和TEM-EDS观察表明，铀被吸附在生物吸附剂的表面和内部。FTIR和XPS结果证实了氧气在从水溶液中捕获铀方面的作用。XPS分析表明，U（VI）和U（IV）的混合物存在于生物吸附剂表面，这表明铀在微生物学上被还原。