Tianjin Key Laboratory of Marine Resources and Chemistry, College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, Tianjin, 300457, China.
Tianjin Key Laboratory of Marine Resources and Chemistry, College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, Tianjin, 300457, China.
J Hazard Mater. 2019 Jun 5;371:694-704. doi: 10.1016/j.jhazmat.2019.03.047. Epub 2019 Mar 12.
A novel ammonium molybdophosphate (AMP)/ polyvinyl alcohol (PVA)/ sodium alginate (SA) composite hydrogel (APS) was prepared for Cs removal and enrichment from radioactive wastewater. Batch experiments with the subject of AMP concentration, pH value, initial Cs concentration, contact time, temperature, competing ions were investigated. The results showed this APS hydrogel with high permeability and stability could effectively adsorb Cs at widely broad pH value range and low Cs concentration within a short time. Adsorption thermodynamic parameters indicated the endothermic and spontaneous nature of the adsorption process, and the Lagergren pseudo-second order model was found to exhibit the best correlation with the adsorption results. Equilibrium data was better described by the Langmuir isotherm equation, and the maximum adsorption capacity of APS hydrogel calculated was in consistent with the experimental results. Furthermore, the APS hydrogel could be easily reused at least five times without obvious decrease in absorption activity and selectivity using ammonia nitrate as the eluent, and what's more, the Cs concentration in eluent was approximately concentrated for 2 times after single cycle. All the results suggest that the environmental friendly and low-cost APS hydrogel could be used as effective and selective material for Cs removal and enrichment from wastewater.
一种新型的铵磷钼酸盐（AMP）/聚乙烯醇（PVA）/海藻酸钠（SA）复合水凝胶（APS）被制备出来，用于从放射性废水中去除和富集铯。对该水凝胶进行了 AMP 浓度、pH 值、初始 Cs 浓度、接触时间、温度、竞争离子等方面的批量实验研究。结果表明，这种具有高渗透性和稳定性的 APS 水凝胶可以在广泛的 pH 值范围和低 Cs 浓度下，在短时间内有效地吸附 Cs。吸附热力学参数表明吸附过程是吸热和自发的，而 Lagergren 拟二级动力学模型与吸附结果具有最佳的相关性。平衡数据更符合 Langmuir 等温线方程，并且计算得到的 APS 水凝胶的最大吸附容量与实验结果一致。此外，APS 水凝胶可以在至少五次的使用中被重复利用，而没有明显降低其吸附活性和选择性，并且使用硝酸铵作为洗脱剂后，洗脱液中的 Cs 浓度在单次循环后可浓缩约 2 倍。所有结果表明，环境友好且成本低廉的 APS 水凝胶可以作为一种从废水中去除和富集 Cs 的有效且选择性的材料。
