Chen Can, Hu Jun, Wang Jianlong
Collaborative Innovation Center for Advanced Nuclear Energy Technology, INET, Tsinghua University, Beijing, 100084, PR China.
Collaborative Innovation Center for Advanced Nuclear Energy Technology, INET, Tsinghua University, Beijing, 100084, PR China; Beijing Key Laboratory of Radioactive Waste Treatment, Tsinghua University, Beijing, 100084, PR China.
J Environ Radioact. 2020 Mar;213:106158. doi: 10.1016/j.jenvrad.2020.106158. Epub 2020 Jan 7.
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.
制备了一种新型生物吸附剂并将其应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，使用0.5 mol/L的硫酸钠包埋酿酒酵母的活细胞（2% w/v）。检测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。通过扫描电子显微镜（SEM）、透射电子显微镜（TEM）和傅里叶变换红外光谱（FTIR）技术观察了它们的超微结构和性质。研究了接触时间、初始铀浓度和初始pH等影响因素。当铀的平衡浓度分别为0.9和43.9 μmol/L时，生物吸附剂的吸附容量从0.75增加到113.4 μmol/g。铀的吸附遵循准一级动力学模型。扫描电子显微镜 - 能谱（SEM - EDS）和透射电子显微镜 - 能谱（TEM - EDS）观察表明，铀吸附在生物吸附剂的表面和内部。傅里叶变换红外光谱（FTIR）和X射线光电子能谱（XPS）结果证实了氧在从水溶液中捕获铀中的作用。X射线光电子能谱分析表明，生物吸附剂表面存在U（VI）和U（IV）的混合物，这证明铀被微生物还原。
