NAKANISHI Takashi Kanazawa University, Department of Science, Associate Professor, 理学部, 助教授 (00019499)
MICHIGAMI Yoshimasa Kanazawa University, Department of Engineering, Resaearch Associate, 工学部, 助手 (90190678)
|Budget Amount *help
¥6,100,000 (Direct Cost : ¥6,100,000)
Fiscal Year 1997 : ¥1,600,000 (Direct Cost : ¥1,600,000)
Fiscal Year 1996 : ¥4,500,000 (Direct Cost : ¥4,500,000)
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
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.