(1. 中南大学 资源与安全工程学院，长沙 410083;
2. 南华大学 铀矿冶生物技术国防重点学科实验室，衡阳 421001;
3. 南华大学 化学化工学院，衡阳 421001)
摘 要: 以纳米Fe3O4磁性微粒负载啤酒酵母菌，制备一种新型铀吸附剂，考察其吸附铀的主要影响因素，即溶液pH值、铀初始浓度、吸附剂投加量及其粒度，分析吸附过程的反应动力学和等温吸附规律，并用扫描电镜和能谱仪分析吸附机理。结果表明：纳米Fe3O4负载啤酒酵母菌(NFSC)吸附铀的最佳条件是pH值为7.0，铀初始浓度为60 mg/ L，NFSC加入量为50 mg，NFSC的最佳粒径为12 nm。NFSC对铀的吸附动力学较好地符合准二级动力学模型，相关系数为0.999 6；吸附等温线均能符合Langmuir和Freundlich等温线模型，说明该吸附体系是一个单层覆盖与多层吸附相结合的模式。扫描电镜和能谱图表明：NFSC吸附铀后表面形态发生变化，且吸附过程中共存物理吸附和化学吸附，属于混合吸附类型。
关键字: 纳米Fe3O4啤酒酵母菌；负载；吸附性能；吸附机理；铀
saccharomyces cerevisiae loaded by nano-Fe3O4 on uranium
（1. School of Resources and Safety Engineering, Central South University, Changsha 410083, China;
2. Key Discipline Laboratory for National Defence for Biotechnology in Uranium Mining and Hydrometallurgy,
University of South China, Hengyang 421001, China;
3. School of Chemistry and Chemical Engineering, University of South China, Hengyang 421001, China）
Abstract:A novel biosorbent was prepared by loading saccharomyces cerevisiae onto nano-Fe3O4 saccharomyces cerevisiae (NFSC), and the factors, including pH value, initial concentration, adsorbent dosage and adsorbent particle size, impacting the adsorption of NFSC on uranium were investigated. The kinetics and adsorption isotherm law were analyzed, and the mechanisms of uranium a, dsorption were discussed by SEM and energy spectrum analysis. The results show that NFSC has high adsorption rate on uranium at the solution pH of 7.0, the adsorbent dosage of 50 mg and the optimal NFSC particle size of 12 nm when the initial concentration of uranium is 60 mg/L. The kinetic model of NFSC can be described by the pseudo-second-order model well, its correlation coefficient is 0.999 6, and the isotherm model is fitted to Langmuir and Freundlich adsorption models, which explains that the adsorption process is monolayer over and multilayer adsorption. The surface form changes because of adsorbing uranium of NFSC. And the adsorption mechanism is mixture adsorption, including the physical and chemical adsorption.
Key words: nano-Fe3O4 saccharomyces cerevisiae; load; adsorption behavior; adsorption mechanism; uranium
