Department of Chemistry, Faculty of Science, University of Tabuk, Tabuk 71421, Saudi Arabia; Department of Polymers and Pigments, National Research Centre, Cairo 12311, Egypt.
Chemistry Department, Faculty of Science, Mansoura University, Mansoura, Egypt.
Int J Biol Macromol. 2023 May 15;237:124073. doi: 10.1016/j.ijbiomac.2023.124073. Epub 2023 Mar 20.
The recovery of uranium from aqueous effluents is very important for both the environment and the future of nuclear power. However, issues of sluggish rates and poor selectivity persist in achieving high-efficiency uranium extraction. In this study, uranyl (UO) ions were imprinted on an amino-phenolic chitosan derivative using an ion-imprinting method. First, 3-hydroxy-4-nitrobenzoic acid (HNB) units were joined to chitosan via amide bonding, followed by reducing the -NO residues into -NH. The amino-phenolic chitosan polymer ligand (APCS) was coordinated with UO ions, then cross-linked with epichlorohydrin (ECH), and finally the UO ions were taken away. When compared to non-imprinted sorbent, the resulting UO imprinted sorbent material (U-APCS) recognized the target ions preferentially, allowing for much higher adsorption capacities (q = 309 ± 1 mg/g) and improved adsorption selectivity for UO. The FTIR and XPS analyses supported the pseudo-second-order model's suggestion that chemisorption or coordination is the primary adsorption mechanism by fitting the data well in terms of kinetics. Also, the Langmuir model adequately explained the isotherms, suggesting UO adsorption in the form of monolayers. The pH value was estimated at around 5.7; thus, the optimum uptake pH was achieved between pHs 5 and 6. The thermodynamic properties support the endothermic and spontaneous nature of UO adsorption.
从水废水中回收铀对于环境和核能的未来都非常重要。然而，在实现高效铀提取方面，仍然存在速率缓慢和选择性差的问题。在这项研究中，采用离子印迹法在氨基-酚醛壳聚糖衍生物上印迹铀酰（UO）离子。首先，通过酰胺键将 3-羟基-4-硝基苯甲酸（HNB）单元连接到壳聚糖上，然后将 -NO 残基还原为 -NH。氨基-酚醛壳聚糖聚合物配体（APCS）与 UO 离子配位，然后用环氧氯丙烷（ECH）交联，最后去除 UO 离子。与非印迹吸附剂相比，所得 UO 印迹吸附剂材料（U-APCS）优先识别目标离子，允许更高的吸附容量（q=309±1mg/g）和改善 UO 的吸附选择性。FTIR 和 XPS 分析支持了拟二级模型的建议，即化学吸附或配位是主要的吸附机制，并且很好地拟合了动力学数据。此外，Langmuir 模型充分解释了等温线，表明 UO 以单层形式吸附。pH 值估计在 5.7 左右；因此，在 pH 值为 5 到 6 之间达到了最佳的吸附 pH 值。热力学性质支持 UO 吸附是吸热和自发的。
