基于铀多元配位的磁性生物吸附剂构建及选择性吸附铀酰离子机理

The biosorption method has been considered as the research hotspot for the uranium-containing wastewater treatment, because of its low cost, low energy consumption, being friendly to environment and its other advantages. Furthermore, the research on biosorption is focused on the construction and recycling of efficient adsorbent with strong selectivity. This study plans to design and synthesize a kind of magnetic biosorbent with multi-ligand for uranium，which has excellent mechanical properties, strong regeneration performance and high cyclic utilization rate. The method for preparing magnetic biosorbent can be carried out according to the following steps: at first, built a kind of hydrophilic magnetic biological carrier with riched amino through domesticating the uranium-philic aspergillus Niger fungus of excellent magnetic property by hydroxylamine hydrochloride, whose magnetic property can come from the excipient of magnetic iron oxide; then, use calix[6]arene as skeleton molecules, whose cavity diameter matched the size of uranyl ion well, and with carboxyl introduced in its benzene ring structure and uranium-philic bidentate ligand amidoxime introduced on its phenolic hydroxyl groups, the calixarene derivatives with multi-ligand for uranium can be synthesized; finally, graft the calixarene derivatives with magnetic fungus carrier by N-acylation, and the last products will be magnetic biosorbent. Based on the physical and chemical characteristics of functional adsorbent and its adsorption experiments on low concentration of uranium-containing wastewater, we can explore its behavior and mechanism of selective bonding uranyl ion so as to provide theoretical basis for preferential adsorption for uranium, and meanwhile provide reference for the radioactive liquid waste disposal and the separation and extraction of uranium from low-grade uranium mine.

生物吸附法因其成本低、能耗低、对环境友好等优点一直是含铀废水治理领域研究热点，而其研究重点在于选择性强且高效的吸附剂的构建与回收。本研究拟通过磁性四氧化三铁固定亲铀真菌黑曲霉，赋予其优良的磁性能，通过盐酸羟胺驯化获得富含氨基的亲水磁性生物载体；以空腔直径与铀酰离子尺寸匹配的杯[6]芳烃为骨架分子，在苯环结构中引入羧基，在酚羟基上引入亲铀的双齿配体偕胺肟基，设计与合成多元配位铀酰离子的功能化杯芳烃衍生物；然后通过Ｎ-酰化反应将杯芳烃衍生物与磁性真菌载体接枝，构建一种机械性能优良、再生性能强、循环利用率高的多元配位铀的磁性生物吸附剂。通过研究该功能吸附剂物理化学特性并结合吸附低浓度含铀废水（0.1~1mg/L）实验，探讨其选择性键合铀酰离子行为与机理，为选择性吸附铀提供理论依据，同时为低品位铀矿中铀的分离提取及核废液处理提供参考。

生物吸附法因其成本低、能耗低、对环境友好等优点一直是含铀废水治理领域的研究热点，其研究重点在于选择性强且高效的吸附剂的构建与回收。本研究通过磁性四氧化三铁固定亲铀真菌黑曲霉，赋予其优良的磁性能，通过盐酸羟胺驯化获得富含氨基的亲水磁性生物载体；以空腔直径与铀酰离子尺寸匹配的杯[6]芳烃为骨架分子，在苯环结构中引入羧基，在酚羟基上引入亲铀的双齿配体偕胺肟基，设计与合成多元配位铀酰离子的功能化杯芳烃衍生物；然后通过N-酰化反应将杯芳烃衍生物与磁性真菌载体接枝，构建了一系列机械性能优良、再生性能强、循环利用率高的多元配位铀的磁性生物吸附剂。本项目合成得到的杯芳烃衍生物修饰的黑曲磁性生物吸附剂（CDAB）用于吸附低浓度铀的实验结果表明CDAB对铀的去除率可以达到83.6 %且具有较好的选择性；合成得到的偕胺肟修饰的磁性纳米Fe3O4-黑曲霉生物吸附剂（ANFAN）用于吸附低浓度铀的实验结果表明ANFAN最大铀吸附率可达92.35 %；合成得到的黑曲霉磁性生物吸附剂（NFAN）用于吸附低浓度铀的实验结果表明NFAN对6 mg/L铀吸附效果良好，铀吸附量为60.05 mg/g，铀吸附率可达76.36 %；合成得到的复合磁性纳米材料(EPPTMS-MN)用于吸附低浓度铀的实验结果表明EPPTMS-MN对20 mg/L铀溶液的吸附率可高达97.6 %；合成得到的4-磺酰杯[6]芳烃修饰的Fe3O4功能化磁性纳米粒子（MFS）用于吸附低浓度铀的实验结果表明MFS对铀溶液的最大吸附率可达到94.39 %；合成得到的4-磺酰杯[6]芳烃修饰的磁性黑曲霉生物吸附剂（MFSC）用于吸附低浓度铀的实验结果表明MFSC对铀溶液的最大吸附率可达到91.18 %。通过研究得到的功能吸附剂物理化学特性并结合吸附低浓度含铀废水实验，探讨了其选择性键合铀酰离子的行为与机理，为选择性吸附铀提供了理论依据，同时可以为低品位铀矿中铀的分离提取及核废液处理提供参考。