聚乙烯亚胺/苎麻纤维自撑膜对铀酰离子的去除性能

Research on the uranium ion removal performance of polyethyleneimine/ramie fiber self-supporting membranes

  • 摘要: 为应对日益严重的能源和环境污染问题,含铀废水的处理已成为当务之急。为了高效便捷地处理含铀废水,通过低共熔溶剂(DES) (氯化胆碱-草酸体系)处理苎麻纤维后接枝聚乙烯亚胺(PEI)制备聚乙烯亚胺/苎麻纤维自撑膜(PEI/RAM),并将其用于水溶液中铀酰离子(\rmUO_2^2 + )的去除。研究了\rmUO_2^2 + 初始浓度、溶液pH值、吸附时间、温度等条件对吸附剂性能的影响。当铀酰离子初始浓度为20 mg/L、溶液pH为6时,铀酰离子吸附平衡容量达到302 mg·g−1;PEI/RAM的铀吸附过程更接近Langmuir模型和准二级动力学模型。在干扰金属离子(Ca2+、K+、Mg2+、Na+)存在时,PEI/RAM吸附剂表现出对铀酰离子较好的选择性,对\rmUO_2^2 + (20 mg/L)的吸附能力将近其他金属离子(20 mg/L)的70倍。

     

    Abstract: In order to deal with the increasingly serious energy and environmental pollution problems, the treatment of uranium containing wastewater has become an urgent matter. In order to treat uranium containing wastewater efficiently and conveniently, polyethylenimide/ramie fiber self-sustaining membrane (PEI/RAM) was prepared by grafting PEI onto ramie fiber after treatment with low eutic solvent (DES) (choline chloride-oxalic acid system), and was used to remove uranyl ion (\rmUO_2^2 + ) in aqueous solution. The effects of initial concentration of \rmUO_2^2 + , pH value of solution, adsorption time and temperature on the properties of the adsorbent were studied. When the initial concentration of uranyl ion is 20 mg/L and the solution pH is 6, the adsorption equilibrium capacity of uranium reaches 302 mg·g−1. The uranium adsorption process of PEI/RAM is closer to Langmuir model and quasi-second-order kinetic model. In the presence of interfering metal ions (Ca2+, K+, Mg2+, Na+), the poly-ethylenimide/ramie fiber self-supported film (PEI/RAM) adsorbent showed good selectivity for uranyl ions, and its adsorption capacity for \rmUO_2^2 + (20 mg/L) was nearly 70 times that of other metal ions (20 mg/L).

     

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