Wang Hao, Ma Guihua, Zhang Ke, Jia Zhi, Wang Yuzhuo, Gao Li, Liu Bingxin
School of Mechanical Engineering, Qinghai University, Xining 810016, China.
Materials (Basel). 2023 Jun 25;16(13):4583. doi: 10.3390/ma16134583.
Salt lake brine originating from Qinghai, China has abundant cesium resources and huge total reserves. The inorganic ion exchangers ammonium molybdophosphate (AMP) and zirconium phosphate (ZrP) have the significant advantages of separating and extracting Cs as a special adsorbent. Nevertheless, their high solubility in water leads to a decrease in their ability to adsorb Cs in aqueous solutions, causing problems such as difficulty with using adsorbents alone and a difficult recovery. In this work, an environmentally friendly polyurethane sponge (PU sponge) with a large specific surface area is employed as an adsorbent carrier by physically impregnating dopamine-coated AMP and ZrP onto a PU sponge, respectively. The experiment found that under the same conditions, the AMP/PU sponge performs better than the ZrP/PU sponge for Cs adsorption. When the amount of adsorbent reaches 0.025 g, the adsorption capacity reaches saturation. The adsorption efficiency remains above 80% when the concentration of Cs is 5-35 mg/L. The kinetic calculations show that adsorption is spontaneous, feasible, and has a higher driving force at high temperatures. In addition, the power and mechanism of the interaction between adsorbent and adsorbent are explained using the density functional theory calculation. This efficient, stable, and selective Cs adsorbent provides design guidelines.
源自中国青海的盐湖卤水含有丰富的铯资源，总储量巨大。无机离子交换剂磷酸钼铵（AMP）和磷酸锆（ZrP）作为特殊吸附剂，在分离提取铯方面具有显著优势。然而，它们在水中的高溶解度导致其在水溶液中吸附铯的能力下降，引发了诸如单独使用吸附剂困难以及回收困难等问题。在这项工作中，通过将多巴胺包覆的AMP和ZrP分别物理浸渍到具有大比表面积的环保型聚氨酯海绵（PU海绵）上，将其用作吸附剂载体。实验发现，在相同条件下，AMP/PU海绵对铯的吸附性能优于ZrP/PU海绵。当吸附剂用量达到0.025 g时，吸附容量达到饱和。当铯浓度为5 - 35 mg/L时，吸附效率保持在80%以上。动力学计算表明，吸附是自发、可行的，且在高温下具有较高的驱动力。此外，利用密度泛函理论计算解释了吸附剂与吸附质之间相互作用的能量和机理。这种高效、稳定且具有选择性的铯吸附剂提供了设计指导方针。
