镍钴水滑石负载偕胺肟化竹纤维在铀吸附中的应用研究

Research on the Application of Nickel-Cobalt Hydrotalcite-Supported Amidoximized Bamboo Fibers Composite Material in Uranium Adsorption

为设计一种具有实际应用价值且对U(VI)具有高吸附容量的吸附材料,采用乙烯基三乙氧基硅烷作为偶联剂将丙烯腈接枝在可大面积编织的天然竹纤维上,再利用盐酸羟胺水解制备偕胺肟化竹纤维(AOBS)。以AOBS为基底材料,尿素提供碱性条件,利用水热法直接制备镍钴水滑石负载偕胺肟化竹纤维(NiCoLDH/AOBS)。利用XRD表征可知AOBS表面NiCoLDH主要为CoOOH和Ni(OH)_(2),而且NiCoLDH/AOBS具有超亲水特性,可在1s达到完全浸润状态。NiCoLDH/AOBS的最佳吸附pH为6.0,拥有259.80mg·g^(-1)的饱和吸附容量,吸附过程符合准二级动力学方程和Freundlich吸附模型。因此,NiCoLDH/AOBS复合吸附材料是一种具有较高吸附容量和实际应用价值的吸附材料。

In order to design an adsorption material with practical application value and high adsorption capacityf or U(Ⅵ),vinyltriethoxysilane is used as a coupling agent to graft acrylonitrile on the natural bamboo fibers with macro braidability,and the amidoximized bamboo fibers(AOBS)are prepared by hydrolysis of hydroxylamine hydrochloride.Subsequently,AOBS and urea were used as the base material and the basic condition,respectively,and the nickel-cobalt hydrptalcite-supported amidoximized bamboo fibers(NiCoLDH/AOBS) are directly prepared by hydrothermal method.According to the result of XRD characterization,the NiCoLDH on AOBS surface is mainly CoOOH and Ni(OH)_(2).Furthermore,the NiCoLDH/AOBS has super-hydrophilic properties and can reach a fully wetted state within 1 s.The optimum adsorption pH of the NiCoLDH/AOBS is 6.0,and the adsorption capacity is 259.80 mg·g^(-1).The adsorption process is matching with the pseudo-second-order kinetic equation and the Freundlich adsorption model.Therefore,the NiCoLDH/AOBS composite adsorbent is a promising adsorbent with high adsorption capacity and practical application value.