磁性壳聚糖复合材料的制备及其对铀吸附性能研究

Preparation of magnetic chitosan composites and their adsorption properties on uranium

  • 摘要: 对于壳聚糖的回收困难问题,通过引入磁性铁酸锌颗粒来构筑核壳结构的复合纳米颗粒。进一步引入两种不同的官能团,接枝到壳聚糖包覆的磁性铁酸锌/二氧化硅纳米颗粒上,制备出新型、高选择性、耐酸、可重复使用的两种功能化磁性壳聚糖基复合材料(ZSC-P和ZSC-D)。通过调节溶液pH、吸附时间、铀溶液初始浓度、吸附温度探究复合材料的吸附性能;通过动力学和热力学模型对复合材料的铀吸附过程进行研究。pH=4时,ZSC-P吸附容量达到122.16 mg/g;pH=5时,ZSC-D吸附容量达到122.76 mg/g。两种吸附材料的吸附过程均符合准二级动力学模型和 Freundlich模型。ZSC-P和ZSC-D材料均展现出较好的对铀酰离子选择性吸附性能和再生性能。

     

    Abstract: For the difficult recycling problem of chitosan, composite nanoparticles with core-shell structure were constructed by introducing magnetic zinc ferrate particles. Two different functional groups were further introduced and grafted onto the chitosan-coated magnetic zinc ferrate/silica nanoparticles to prepare novel, highly selective, acid-resistant and reusable two functionalized magnetic chitosan-based composites (ZSC-P and ZSC-D). The adsorption properties of the composites were investigated by adjusting the solution pH, adsorption time, initial concentration of uranium solution, and adsorption temperature; and the uranium adsorption process of the composites was investigated by kinetic and thermodynamic modelling.The maximum adsorption capacity of the composites was reached by the adsorbent of ZSC-P at 122.16 mg/g for pH=4, and that of ZSC-D was reached by the adsorbent of ZSC-D at 122.76 mg/g for pH=5. The adsorption processes of both adsorbent materials are as follows. The adsorption processes of the two adsorbent materials were in accordance with the quasi-secondary kinetic model and the Freundlich model, and both ZSC-P and ZSC-D materials showed good selective adsorption and regeneration properties for uranyl ions.

     

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