School of Chemistry and Chemical Engineering, University of South China, Hengyang, 421001, People's Republic of China.
Hunan Key Laboratory for the Design and Application of Actinide Complexes, Hengyang, 421001, People's Republic of China.
Environ Sci Pollut Res Int. 2024 Apr;31(17):26204-26216. doi: 10.1007/s11356-024-32943-5. Epub 2024 Mar 18.
In this paper, we prepared three types of porous glasses (PGs) with specific surface areas of 311.60 m/g, 277.60 m/g, and 231.38 m/g, respectively, via borosilicate glass phase separation. These glasses were further modified with amidoxime groups (AO) using the hydroxylamine method, yielding adsorbents named 1.5-PG-AO, 2-PG-AO, and 3-PG-AO. The adsorption performance of these adsorbents under various conditions was investigated, including sorption kinetics and adsorption mechanisms. The results reveal that the number of micropores and specific surface area of PG are significantly reduced after AO modification. All three adsorbents exhibit similar adsorption capabilities. Particularly, pH has a pronounced effect on U (VI) adsorption of PG-AO, with a maximum value at pH = 4.5. Equilibrium adsorption is achieved within 2 h, with a maximum adsorption capacity of 129 mg/g. Notably, a uranium removal rate of 99.94% is attained. Furthermore, the adsorbents show high selectivity in uranium solutions containing Na or K. Moreover, the adsorbents demonstrate exceptional regeneration ability, with the removal rate remaining above 80% even after undergoing five adsorption-desorption cycles. The adsorption reaction of uranium on PG-AO involves a combination of multiple processes, with monolayer chemisorption being the dominant mechanism. Both the complex adsorption of AO and the ion exchange and physical adsorption of PG contribute to the adsorption of uranyl ions on the PG-AO adsorbents.
本文通过硼硅酸盐玻璃分相法制备了比表面积分别为 311.60 m/g、277.60 m/g 和 231.38 m/g 的三种多孔玻璃（PG）。然后，采用羟胺法将这些玻璃进一步修饰成偕胺肟基团，得到了三种吸附剂，分别命名为 1.5-PG-AO、2-PG-AO 和 3-PG-AO。研究了这些吸附剂在不同条件下的吸附性能，包括吸附动力学和吸附机制。结果表明，AO 修饰后 PG 的微孔数量和比表面积显著减少。三种吸附剂的吸附能力相似。特别地，pH 值对 PG-AO 吸附铀（VI）有显著影响，在 pH=4.5 时达到最大值。2 h 内达到吸附平衡，最大吸附容量为 129 mg/g。值得注意的是，铀的去除率达到 99.94%。此外，吸附剂在含有 Na 或 K 的铀溶液中表现出高选择性。此外，吸附剂具有出色的再生能力，即使经过五次吸附-解吸循环，去除率仍保持在 80%以上。铀在 PG-AO 上的吸附反应涉及多种过程的复合，单层化学吸附是主要机制。AO 的络合吸附以及 PG 的离子交换和物理吸附都有助于 PG-AO 吸附剂对铀酰离子的吸附。
