高氟高氯含铀废水中偕胺肟基改性聚丙烯腈纤维螯合铀的研究

以聚丙烯腈纤维（PANF）为基体与盐酸羟胺反应制得偕胺肟基改性纤维（AO-PANF），并通过扫描电镜、红外光谱和批次吸附，探究了AO-PANF对高氟高氯含铀废水中铀的螯合行为。结果表明，偕胺肟化反应将PANF中的氰基成功转化为偕胺肟基团，转化率随盐酸羟胺浓度增加而增大，氰基转化率为22.34%时，AO-PANF对铀的吸附量最大。随废水pH增加，AO-PANF对铀的吸附量先增大后减小，pH为5时，其值最大。F^-和Cl^-浓度变化对AO-PANF的吸附量影响较小。当处理100 ml铀初始浓度为100 mg·L^-1，pH为5的废水，温度为45℃，吸附剂投加量为0.40 g时，转化率为22.34%的AO-PANF对铀的吸附量为19.53 mg·g^-1，3 h左右吸附达到平衡。AO-PANF通过偕胺肟基团中-NH₂与废水中UO₂F₄^2-螯合实现对铀的吸附。该吸附过程符合Freundlich等温吸附模型和准二级动力学方程。研究表明AO-PANF可以有效地螯合高氟高氯含铀废水中的铀，具有良好的应用前景。

Amidoxime modified polyacrylonitrile fiber based uranium chelation from wastewater containing uranium in presence of fluoride and chlorine with high concentration

Amidoxime modified polyacrylonitrile fiber (AO-PANF) was prepared by reacting polyacrylonitrile fiber (PANF) as fundamental materials with hydroxylamine hydrochloride. The chelation behavior of AO-PANF to uranium from wastewater containing uranium in the presence of fluoride and chlorine with high concentration was investigated by Scanning Electron Microscopy, Fourier Transform Infrared Spectra and batch adsorption. The results showed that nitrile groups were successfully transformed into amidoxime groups by the amidoximation reaction. The conversion rate of nitrile groups increased with the increasing concentration of hydroxylamine hydrochloride. The adsorption quantity of uranium reached up the largest value when the conversion rate of nitrile group was 22.34%. The adsorption quantity of AO-PANF to uranium increased and then decreased with increasing pH, and the maximum adsorption quantity was obtained at pH 5. The concentrations of both F^- and Cl^- have little effect on the adsorption quantity of AO-PANF to uranium. The maximum adsorption quantity of AO-PANF (22.34% conversion rate of nitrile groups) to uranium in 100 ml wastewater (100 mg·L^-1 initial concentration of uranium) was 19.53 mg·g^-1 under the condition of pH 5, 45℃ and 0.40 g adsorbent dose, and the adsorption experiment reached equilibrium after 3 h. AO-PANF adsorbed uranium through chelation between the -NH₂ of amidoxime groups and UO₂F₄^2- of wastewater. The adsorption process conformed to Freundlich isothermal adsorption model and pseudo-second order kinetic equation. It was shown that AO-PANF can effectively extract uranium from wastewater containing uranium in the presence of fluoride and chlorine with high concentration, and has a promising application prospect.