School of Environmental and Resources, Southwest University of Science and Technology, Mianyang, Sichuan, 621010, PR China; School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, Sichuan, 621010, PR China; National Co-innovation Center for Nuclear Waste Disposal and Environmental Safety, Southwest University of Science and Technology, Mianyang, Sichuan, 621010, PR China; State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, PR China.
School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, Sichuan, 621010, PR China; National Co-innovation Center for Nuclear Waste Disposal and Environmental Safety, Southwest University of Science and Technology, Mianyang, Sichuan, 621010, PR China; State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, PR China.
J Hazard Mater. 2020 Mar 5;385:121588. doi: 10.1016/j.jhazmat.2019.121588. Epub 2019 Nov 8.
Further understanding absorption uranium mechanism of the regenerational biosorbent is very interesting in application of the biosorbent. The regeneration adsorbent of Saccharomyces cerevisiae biomass was made by hydrochloric acid. Using it to absorb uranium at low constant pH(2.50), accompanied with proton releasing the ratio almost 1:2 which is to be analyzed in this paper. The type and amount of functional groups in the biomass such as carboxyl, amino, phosphoryl were determined by Potentiometric titrations and FTIR analysis. Chemical modification showed that the contribution of functional groups to uranium adsorption was carboxyl, phosphoryl and amino in turn. Analysis of SEM-EDX and staining microscopy showed that uranium on the surface of cells did not exist in the form of precipitation at lower pH 2.98, but at higher pH 4.52. The effects of phosphorus release and pH on uranium species was analyzed by MINTEQ software 3.0. Based on the above boundary conditions of the model construction, a multi-site of functional groups model equation of ion exchange absorption mechanism was built in which the final uranium ion concentration and pH as functions. It could well describe the exchange equilibrium of proton with uranium ion at pH2.50 to pH4.00.
进一步了解再生生物吸附剂对铀的吸收机制在生物吸附剂的应用中非常有趣。通过盐酸制备了酿酒酵母生物质的再生吸附剂。在低恒定 pH（2.50）下用它来吸附铀，伴随着质子释放，其比例几乎为 1:2，这是本文要分析的。通过电位滴定和 FTIR 分析确定了生物质中羧基、氨基、磷酸基等官能团的类型和数量。化学修饰表明，官能团对铀吸附的贡献依次为羧基、磷酸基和氨基。SEM-EDX 分析和染色显微镜表明，在较低的 pH 值 2.98 下，铀并不以沉淀的形式存在于细胞表面，而是在较高的 pH 值 4.52 下存在。通过 MINTEQ 软件 3.0 分析了磷释放和 pH 值对铀形态的影响。基于模型构建的上述边界条件，建立了一个多官能团离子交换吸附机制的方程，其中最终的铀离子浓度和 pH 值作为函数。它可以很好地描述在 pH 值 2.50 到 pH 值 4.00 范围内质子与铀离子的交换平衡。
