Studies on recovery of uranyl carbonate and concentration of the isotopes using high efficient amino acid resins

1.高效氨基酸树脂的合成及树脂性能：采用固相合成法将氨基酸或模拟氨基酸引入聚苯乙烯树脂中，合成了30种氨基酸树脂。引入的氨基酸含量约为2~3.7 mmol/g树脂(引入速率为73~100%)，并通过离子交换容量、水分含量、FT-IR等测试来评价树脂性能。考察了树脂的酸洗、碱浸和重复使用的洗涤效果，表明所研制的树脂是高效的功能性树脂。树脂对铀的捕集能力和选择功能：我们实际上对树脂进行了高度官能化，因为它们具有耐用性和大的平衡吸附量，例如，在Arg和β-Ala-AMR树脂中，超过1gU/g树脂。我们还发现Re…具有很高的吸附活性。树脂对铀的吸附顺序为硝酸盐和溴化物+硫酸盐碳酸盐。树脂中质子化的氨基残基可能是吸附的驱动力，并通过吸附、从钍和重金属混合物中宏观分离以及从海水基质中回收铀的等值分析证实了其选择性吸附作用。此后，树脂向纤维吸附剂的发展将是可取的。铀同位素的分离和浓缩行为：通过与树脂接触，采用间歇法跟踪天然铀同位素的分离和浓缩行为。用α-射线法测得各树脂中~(234)&GT；U/~(238)&GT；U的分离因子。在PST树脂中通过酯键合引入氨基酸的酯型树脂比氨基键合的树脂具有更大的浓缩效应。这表明树脂中氨基酸的氧化-氧化还原作用是浓度的加速因子。虽然这一效果取决于氨基酸的引入、溶液和温度条件，但有些树脂的分离倍数比溶液中的氧化-氧化还原平衡高330倍以上，比络合方法高8600倍以上。用电感耦合等离子体质谱(ICP-MS)法测定~(235)&U/~(238)&~(gt；U)因子。但是，由于测量误差较大，我们不能完全进行意义评估。此外，通过将树脂浸泡在海水中，我们发现了同位素的分离趋势。今后，人们可以预期氨基酸树脂将应用于具有高度多级接触的分离系统。较少

1. Synthesis of high efficient amino acid resins and the resin properties : We have synthesized 30 types of amino acid resin, introducing amino acid or imitative amino acids into poystirene resin according to the solid phase synthetic method of peptides. Amino acid contents introduced were estimated to be about 2-3.7 mmol/g-resin (introducing rates, 73-100%) and the resin properties were evaluated by the measurement of ion exchange capacity, water content, FT-IR and etc.. We alsoinvestigated a washing effect with acids, alkali soaking and repeated uses of the resins, and clarified that the developed resins were highly efficient and functinal ones.2. Collction capacity and selection function of the resins to uranium : We have practically performed a high functionalization of the resins, because they possessed the durability for use and large equilibrium adsorption amounts, e.g., above 1gU/g-resin in Arg-and beta -Ala-AMR resins. We have also recognized high adsorptive activity of the re … More sins toward cabonate species of uranium, and the adsorptive order of uranium salts was nitrate < bromide < acetate < chloride < sulfate carbonate.The protonated amino residue in the resin may behave as a driving force for adsorptions, and the selective adsorptive function was confirmed by the isoterm analysis for adsoption, macro separation from thorium and heavy metal mixtures, and uranium recovery from sea water matrixes. Thereafter, the development of the resin to fibrous adsorbent would be desirable.3. Separation and concentration behaviors of uranium isotopes : The separation and concentration behaviors of natural uranium isotopes were tracesd by contacting the resins using batch method. The separation factors of ^<234>U/^<238>U in each resin were determined by alpha -ray measurement. The ester type resins introduced amino acid by ester bonding into PSt resin showed larger concentration effect than that of amido-bonding types. It suggests that the oxidation -redox action of amino acid within the resin behaved as a acceleration factor for the concentration. Although this effect would depend upon amino acids introduced and solution and temparature conditions, some resing showed separation factors above 330 times comparing with that of the oxidation-redox equilbria in solution and above 8600 times against the complxation method. The factors of ^<235>U/^<238>U were measured by ICP-MS method. But, we could not perform wholly a meaning evaluation, due to large errors at the measurement. Besides, we recognized separation trends of the isotopes by soaking the resins in sea water. Hereafter, one might expect that amino acid resins would be applied to the separation system with high multistage contact. Less