Hamza Mohammed F, Mubark Amal E, Wei Yuezhou, Vincent Thierry, Guibal Eric
Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials, School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China.
Nuclear Materials Authority, POB 530, El-Maadi, Cairo11835, Egypt.
Gels. 2020 Mar 30;6(2):12. doi: 10.3390/gels6020012.
The necessity to recover uranium from dilute solutions (for environmental/safety and resource management) is driving research towards developing new sorbents. This study focuses on the enhancement of U(VI) sorption properties of composite algal/Polyethylenimine beads through the quaternization of the support (by reaction with glycidyltrimethylammonium chloride). The sorbent is fully characterized by FTIR, XPS for confirming the contribution of protonated amine and quaternary ammonium groups on U(VI) binding (with possible contribution of hydroxyl and carboxyl groups, depending on the pH). The sorption properties are investigated in batch with reference to pH effect (optimum value: pH 4), uptake kinetics (equilibrium: 40 min) and sorption isotherms (maximum sorption capacity: 0.86 mmol U g). Metal desorption (with 0.5 M NaCl/0.5 M HCl) is highly efficient and the sorbent can be reused for five cycles with limited decrease in performance. The sorbent is successfully applied to the selective recovery of U(VI) from acidic leachate of uranium ore, after pre-treatment (cementation of copper, precipitation of rare earth elements with oxalate, and precipitation of iron). A pure yellow cake is obtained after precipitation of the eluate.
从稀溶液中回收铀（出于环境/安全和资源管理的需要）推动了新型吸附剂研发方面的研究。本研究聚焦于通过载体的季铵化（与缩水甘油基三甲基氯化铵反应）来增强复合藻类/聚乙烯亚胺珠对U(VI)的吸附性能。该吸附剂通过傅里叶变换红外光谱（FTIR）、X射线光电子能谱（XPS）进行了全面表征，以确认质子化胺和季铵基团对U(VI)结合的贡献（根据pH值，羟基和羧基可能也有贡献）。参照pH值影响（最佳值：pH 4）、吸附动力学（平衡时间：40分钟）和吸附等温线（最大吸附容量：0.86 mmol U g），采用分批法对吸附性能进行了研究。金属解吸（用0.5 M NaCl/0.5 M HCl）效率很高，该吸附剂可重复使用五个循环，性能仅有有限下降。经过预处理（铜的置换沉淀、草酸盐沉淀稀土元素以及铁的沉淀）后，该吸附剂成功应用于从铀矿酸性浸出液中选择性回收U(VI)。洗脱液沉淀后得到了纯黄饼。
