Hot Laboratory Center, Atomic Energy Authority of Egypt, P.O. 13759, Inshas, Cairo, Egypt.
Hot Laboratory Center, Atomic Energy Authority of Egypt, P.O. 13759, Inshas, Cairo, Egypt.
Environ Res. 2020 Jun;185:109402. doi: 10.1016/j.envres.2020.109402. Epub 2020 Mar 16.
The feasibility of using Cyanex 301 impregnated onto biopolymer resin for removing cobalt from radioactive waste streams is investigated. The emulsion compositions for resin preparation were optimized to ensure compliance with nuclear grade resin specifications on particle size distribution and chemical stabilities using multi-variant analysis. The enhanced chemical stabilities of the resins in different solutions are attributed to the interaction between Cyanex 301 and the emulsifier with alginate via a reaction with the glycosidic bond. The structure and morphology of the three optimized samples were studied using FTIR, SEM, and TGA and their end-of-life cycle treatment was preliminarily investigated. Equilibrium sorption investigations revealed that the sorption is taking place via bi-layers onto two sites on the surface layer independently from the cobalt contamination level and the nature of these sites were characterized by determining the energy barriers and fraction of the weak and strong sites. Cobalt adsorption is chemical spontaneous endothermic reaction and the loaded material spectroscopic analysis and thermodynamics calculations referred to chemical coordination and hydrogen bonding. The enhanced radiological stabilities of the optimum resins at irradiation fields <100 KGy were explained and the relations between the loss of exchange capacity and the doses were quantified. The resins could be regenerated using 0.5 M HCl and the effect of the elution cycles on cobalt uptake was presented.
研究了用负载在生物聚合物树脂上的 Cyanex 301 从放射性废水中去除钴的可行性。通过多变量分析优化了树脂制备的乳液组成，以确保符合核级树脂在粒度分布和化学稳定性方面的规格。树脂在不同溶液中的化学稳定性增强归因于 Cyanex 301 与乳化剂之间通过与糖苷键反应与藻酸盐的相互作用。使用 FTIR、SEM 和 TGA 研究了三个优化样品的结构和形态，并初步研究了它们的使用寿命结束后的处理方法。平衡吸附研究表明，吸附是通过双层独立于钴污染水平和这些位点的性质在表面层上的两个位点上发生的，这些位点的性质通过确定能量障碍和弱位点和强位点的分数来表征。钴吸附是化学自发的吸热反应，负载材料的光谱分析和热力学计算涉及化学配位和氢键。解释了最佳树脂在辐照场<100KGy 下的增强放射稳定性，并量化了交换容量损失与剂量之间的关系。树脂可以用 0.5M HCl 再生，并提出了洗脱循环对钴吸收的影响。
