偕胺肟基接枝聚酰胺微孔膜吸附材料的制备及其盐湖水提铀性能研究  

Preparation of amidoxime grafted polyamide microporous membrane adsorbent and its uranium extraction performance investigation from salt lake water

作　　者：高思凡 蒋纪宇 骆微 廖学品[1] 石碧[1] GAO Si-fan;JIANG Ji-yu;LUO wei;LIAO Xue-pin;SHI Bi(College of Biomass Science and Engineering,Sichuan University,Chengdu 610065,China)

机构地区：[1]四川大学轻工科学与工程学院,四川成都610065

出　　处：《化学研究与应用》2024年第5期1056-1066,共11页Chemical Research and Application

基　　金：国家自然科学基金区域创新发展联合基金(U21A20304)资助;中国海水提铀技术创新联盟2021-2022年度创新发展基金(CNNC-CXLM-202210)资助。

摘　　要：以聚酰胺微孔膜为基材,通过自由基引发将丙烯腈接枝于膜表面,并用盐酸羟胺肟化得到偕胺肟基接枝聚酰胺微孔膜吸附材料(PA-AO),该膜吸附材料结合了膜分离处理量大和吸附分离选择性高的优点。研究结果表明,在纯水体系中,当pH=6.0,铀初始浓度为1.0mmol·L^(-1),303K条件下,PA-AO对UO_(2)^(2+)的平衡吸附量可达0.47mmol·g^(-1)。吸附过程符合Langmuir模型和准二级动力学方程,盐湖水中存在的阴离子以及阳离子对铀吸附的影响很小,PA-AO对铀表现出较高的吸附选择性。使用1.0mol·L^(-1)的Na2CO3和0.1mol L-1的H_(2)O_(2)的混合溶液可将铀从PA-AO上解吸下来,解吸率达到90.2%,且重复利用性能较好。连续吸附实验表明,当铀的初始进料浓度为0.05mmol·L^(-l),流速为4.0mL·min^(-1)时,PA-AO的处理能力达到275.02L·m^(-2),对铀的回收率达到90%以上。将PA-AO用于提取1L模拟盐湖水中的铀,铀的提取量达到了235.59μg,提取率达81.0%,这表明PA-AO可用于盐湖水中铀的高效提取。Amidoxime grafted polyamide microporous membrane adsorbent(PA-AO)was prepared by grafting acrylonitrile onto the surface of the polyamide microporous membrane via free radical polymerization and then modification with hydroxylamine hydrochloride.The membrane adsorbent combines the advantages of a large processing capacity of membrane separation and high selectivity of adsorption separation.The experimental results showed that the equilibrium adsorption capacity of UO_(2)^(2+)by PA-AO was up to 0.47 mmol·g^(-1)in the pure water system at 303 K,pH=6.0,and the initial uranium concentration was 1.0 mmol·L^(-1).Furthermore,the adsorption process of uranium by PA-AO was well described by the Langmuir model and the pseudo-second-order kinetic equations.The coexisting anions and cations in the salt lake water had litle effect on uranium adsorption,and PA-AO showed excellent adsorption selectivity for uranium.Uranium can be desorbed from PA-AO using a mixture of 1.0 mol L^(-1)Na_(2)CO_(3) and O.1 mol L^(-1)H_(2)O_(2)with a desorption efficiency of 90.2%and PA-AO has good reusability.The continuous adsorption experiments showed that when the initial concentration of uranium was 0.05 mmol·L^(-1)and the flow rate was 4.0 mL·min^(-1),the processing capacity of PA-AO reached 275.02 L·m^(-2),and the recovery rate of uranium reached more than 90%.The PA-AO was used to extract uranium fromI L of simulated salt lake water,and the amount of uranium extracted reached 235.59μg with an extraction efficiency of 81.0%,which indicates that PA-AO can be used for the efficient extraction of uranium from salt lake water.

关 键 词：偕胺肟基 铀 膜吸附分离 聚酰胺微孔膜 盐湖水 

分 类 号：O633.22[理学—高分子化学]