Jiangxi Province Key Laboratory of Synthetic Chemistry, East China University of Technology, 330013 Nanchang, China; State Key Laboratory for Nuclear Resources and Environment, East China University of Technology, 418 Guanglan Road, 330013 Nanchang, China.
State Key Laboratory for Nuclear Resources and Environment, East China University of Technology, 418 Guanglan Road, 330013 Nanchang, China.
Int J Biol Macromol. 2024 Nov;279(Pt 2):135011. doi: 10.1016/j.ijbiomac.2024.135011. Epub 2024 Aug 23.
The biosorption is considered to be highly efficient for the separation of radionuclide from radioactive wastewater. Herein, the crosslinked chitosan assisted EDTA intercalated Ca-Mg-Al layered double hydroxides composite foam (CS-EDTA-LDH) was synthesized by combining EDTA intercalation and freeze-drying methods. The macroporous and ultralight properties of CS-EDTA-LDH facilitates its rapid adsorption and facile recovery, and the inorganic/organic incorporation can avoid pore collapse and provide numerous adsorption sites, while the EDTA intercalation can enhance the complex capture of U(VI). The CS-EDTA-LDH presents various functional groups (carboxyl, hydroxyl and amino groups) for U(VI) adsorption, and the adsorption capacity for U(VI) reached 272.3 mg/g at pH 5.0 and 298 K. The adsorption kinetics of U(VI) conformed to PSO equation, whereas the isotherms conformed to the Freundlich model, indicating heterogeneous adsorption with diffusion process as a rate-controlling step. The thermodynamic parameters indicate that U(VI) adsorption by CS-EDTA-LDH is endothermic and spontaneous in nature. The adsorption mechanism is related to the synergic complexation by multi-functional groups, ion exchange, and possible isomeric substitution. Overall, CS-EDTA-LDH could be a promising biosorbent for the cleanup of radioactive pollution due to its high performance for U(VI) adsorption and facile recovery.
吸附被认为是从放射性废水中分离放射性核素的一种高效方法。在此，通过结合 EDTA 插层和冷冻干燥方法，合成了交联壳聚糖辅助 EDTA 插层 Ca-Mg-Al 层状双氢氧化物复合泡沫（CS-EDTA-LDH）。CS-EDTA-LDH 的大孔和超轻特性有利于其快速吸附和易于回收，并且无机/有机掺入可以避免孔塌陷并提供众多吸附位点，而 EDTA 插层可以增强 U(VI)的复杂捕获。CS-EDTA-LDH 具有各种官能团（羧基、羟基和氨基），可用于 U(VI)吸附，在 pH 5.0 和 298 K 时，对 U(VI)的吸附容量达到 272.3 mg/g。U(VI)的吸附动力学符合 PSO 方程，而等温线符合 Freundlich 模型，表明吸附过程是一个扩散控制的非均相吸附。热力学参数表明，CS-EDTA-LDH 对 U(VI)的吸附是吸热和自发的。吸附机制与多官能团的协同络合、离子交换和可能的同晶取代有关。总的来说，CS-EDTA-LDH 由于其对 U(VI)的高吸附性能和易于回收的特点，有望成为一种用于放射性污染清理的生物吸附剂。
