Selective extraction of U(VI) over Th(IV) from acidic streams using di-bis(2-ethylhexyl) malonamide anchored chloromethylated polymeric matrix.
Selective extraction of U(VI) over Th(IV) from acidic streams using di-bis(2-ethylhexyl) malonamide anchored chloromethylated polymeric matrix.
复制标题
使用二-双(2-乙基己基)丙二酰胺锚定的氯甲基化聚合物基质从酸性流中选择性萃取 U(VI) 而非 Th(IV)。
DOI：
10.1016/j.talanta.2004.06.003
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发表时间：
2004
期刊：
影响因子：
6.1
通讯作者：
M. S. Subramanian
中科院分区：
文献类型：
--
作者：
D. Prabhakaran;M. S. Subramanian
以二-双（2-乙基己基）丙二酰胺（DB2 EHM）为锚定物，以梅里菲尔德氯甲基化树脂为吸附剂，制备了一种新型螯合吸附剂。用13 C CPMAS NMR、FT-NIR-FIR、CHN元素分析和热重分析对改性树脂进行了表征。制备的吸附剂显示出优越的上级的U（VI）的Th（IV）和其他不同的离子的结合亲和力，即使在高酸度。各种物理化学参数，如溶液酸度、相交换动力学、金属吸附能力、电解质耐受性研究等，采用静态和动态两种方法研究了影响树脂金属萃取性能的因素。在宽范围的溶液酸度（0.01- 10 M）进行的分批萃取研究表明，即使高达4 M的酸度，分配比（D）在100 - 103的顺序，可以实现选择性萃取U（VI）。U（VI）和Th（IV）的相交换动力学研究表明，99.5%的提取时间<15min was sufficient for >。但是当对三价镧系元素进行类似的研究时，得到非常低的D值（<50），萃取时间延长至60分钟。在5 M HNO 3下对U（VI）和Th（IV）进行的金属吸附研究分别为62.5和38.2mgg− 1。在推断电解质物种和无机阳离子的存在下的提取效率也进行了检查。用10- 15 mL的1 M（NH_4）_2CO_3或0.5M α-羟基异丁酸（HIBA）解吸金属离子是有效的。在5 M酸度的色谱柱上进行的提取研究发现，给富集因子值为310和250的U（VI）和Th（IV），分别。使用合成的核乏燃料溶液测试了所制造的螯合吸附剂的实际效用及其从酸性废物流中提取锕系元素的效率。R.S.D.三次测量（n = 3）获得的值在5.2%以内。
A new chelating polymeric sorbent has been developed using Merrifield chloromethylated resin anchored with di-bis (2-ethylhexyl) malonamide (DB2EHM). The modified resin was characterized by13C CPMAS NMR spectroscopy, FT–NIR–FIR spectroscopy, CHN elemental analysis and also by thermo gravimetric analysis. The fabricated sorbent showed superior binding affinity for U(VI) over Th(IV) and other diverse ions, even under high acidities. Various physio-chemical parameters, like solution acidity, phase exchange kinetics, metal sorption capacity, electrolyte tolerance studies, etc., influencing the resin’s metal extractive behavior were studied by both static and dynamic method. Batch extraction studies performed over a wide range of solution acidity (0.01–10M) revealed that selective extraction of U(VI) could be achieved even up to 4M acidity with distribution ratios (D) in the order of ∼103. The phase exchange kinetics studies performed for U(VI) and Th(IV) revealed that time duration of <15min was sufficient for >99.5% extraction. But similar studies when preformed for trivalent lanthanides gave very low D values (<50), with the extraction time extending up to 60min. The metal sorption studies performed for U(VI) and Th(IV) at 5M HNO3was found to be 62.5 and 38.2mgg−1,respectively. Extraction efficiency in the presence of inferring electrolyte species and inorganic cations were also examined. Metal ion desorption was effective using 10-15mL of 1M (NH4)2CO3or 0.5M α-hydroxy isobutyric acid (HIBA). Extraction studies performed on a chromatographic column at 5M acidity were found to give enrichment factor values of 310 and 250 for U(VI) and Th(IV), respectively. The practical utility of the fabricated chelating sorbent and its efficiency to extract actinides from acidic waste streams was tested using a synthetic nuclear spent fuel solution. The R.S.D. values obtained on triplicate measurements (n = 3) were within 5.2%.