Kesava Raju Ch Siva, Subramanian M S
Department of Chemistry, Indian Institute of Technology, Chennai 600036, India.
J Hazard Mater. 2007 Jun 25;145(1-2):315-22. doi: 10.1016/j.jhazmat.2006.11.024. Epub 2006 Nov 18.
A novel grafted polymer for selective extraction and sequential separation of lanthanides, thorium and uranium from high acidic wastes has been developed by grafting Merrifield chloromethylated (MCM) resin with octyl(phenyl)-N,N-diisobutylcarbamoyl-methylphosphine oxide (CMPO) (MCM-CMPO). The grafting process is well characterized using FT-IR spectroscopy, (31)P and (13)C CPMAS (cross-polarized magic angle spin) NMR spectroscopy and CHNPS elemental analysis. The influence of various physico-chemical parameters during metal ion extraction by the resin phase are studied and optimized by both static and dynamic methods. The resin shows very high sorption capacity values of 0.960mmolg(-1) for U(VI), 0.984mmolg(-1) for Th(IV), 0.488mmolg(-1) for La(III) and 0.502mmolg(-1) for Nd(III) under optimum HNO(3) medium, respectively. The grafted polymer shows faster rate exchange kinetics (<5min is sufficient for 50% extraction) and greater preconcentration ability, with reusability exceeding 20 cycles. During desorption process, sequential separation of the analytes is possible with varying eluting agents. The developed grafted resin has been successfully applied in extracting Th(IV) from high matrix monazite sand, U(VI) and Th(IV) from simulated nuclear spent fuel mixtures. All the analytical data is based on triplicate analysis and measurements are within 3.5% rsd reflecting the reproducibility and reliability of the developed method.
通过将辛基（苯基）-N，N-二异丁基氨基甲酰甲基氧化膦（CMPO）接枝到氯甲基化的Merrifield树脂（MCM）上，制备了一种新型接枝聚合物，用于从高酸性废物中选择性萃取和顺序分离镧系元素、钍和铀（MCM-CMPO）。采用傅里叶变换红外光谱、（31）P和（13）C交叉极化魔角旋转核磁共振光谱以及CHNPS元素分析对接枝过程进行了充分表征。通过静态和动态方法研究并优化了树脂相萃取金属离子过程中各种物理化学参数的影响。在最佳硝酸介质下，该树脂对U（VI）、Th（IV）、La（III）和Nd（III）的吸附容量分别高达0.960 mmol g-1、0.984 mmol g-1、0.488 mmol g-1和0.502 mmol g-1。接枝聚合物显示出更快的交换动力学速率（50%萃取5分钟内即可完成）和更强的预富集能力，可重复使用超过20个循环。在解吸过程中，使用不同的洗脱剂可以实现分析物的顺序分离。所制备的接枝树脂已成功应用于从高基体独居石砂中萃取Th（IV），从模拟核乏燃料混合物中萃取U（VI）和Th（IV）。所有分析数据均基于三次重复分析，测量相对标准偏差在3.5%以内，表明所开发方法具有重现性和可靠性。
