APPLICATION OF PYRIDINE-TYPE AND AMINE-TYPE ANIONEXCHANGE RESIN FOR SEPARATING FISSION PRODUCT

ELEMENTS IN METHANOL -HYDROCHLORICACm MIXED MEDIA

Rifaid M. Nur*

ABSTRACTAPPLICATION OF PYRIDINE- TYPE AND AMINE- TYPE ANION

EXCHANGE RESIN FOR SEPARATING FISSION PRODUCT ELEMENTS INMETHANOL -HYDROCHLORIC ACID MIXED MEDIA. Column experiments wereconducted by using tertiary pyridine-type resin and some types of amine anion exchange resinwith MeOH -HCI mixed solution as eluent. The aim of this work is to confirm theapplicability of the pyridine-type resin and to investigate the possibility of some types ofamine anion exchange resin to be used for separating some fission product elements,especially 137CS from '"'Sr and '"'V in MeOH -HCI mixed solvent at room temperature.The results show that there are some differencies in retention of the elements. The differenciesin retention of the elements in the column experiment using tertiary pyridine-type orquaternary ammonium resin is higher than that obtained using tertiary, secondary and primaryamine resin when 50% MeOH -0.5 M HCI mixed solution is used as eluent. Therefore, insuch a system, tertiary pyridine-type and quaternary ammonium anion exchange resin can beapplied for separating '"IV from "'Sr and 137CS, if multi stages chromatography is used.In addition, uranium is confirmed to be completely separated from alkali, alkaline earth,rare earth, and most transition metal elements by using the tertiary pyridine-type resin

in such a system.

INTRODUCTION

The management of high-level radioactive wastes generated in nuclearfuel reprocessing is one of the most important items to be solved before thefuture deployment of nuclear energy in the global scale.

Kubota and co-workers at Japan Atomic Energy Research Institute(JAERIY have developed a partitioning technology for separating elementsin high-level liquid waste (HLLW). The HLLW is divided into four groups,those are (I) trans-uranium (TRU) elements, (2) Tc -platinum group metals(PGM), (3) Sr-Cs and (4) the others. AU TRU elements includingpentavalent Np are extracted with diisodecylphosphoric acid (DIDP A) afterthe denitration of HLL W, reducing the nitric acid concentration from 2 M to0.5 M; Tc and PGM are separated by precipitation through denitration or byadsorption with an active carbon; and Sr and Cs are separated by adsorptionwith inorganic ion exchanger (titanic acid and zeolite, respectively).

.Center for Development of Radioactive Waste Management, BATAN, Indonesia

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To prevent corrosion of the high-level nuclear waste storage tanks, theliquid-waste was made alkaline by addition of sodium hydroxide beforerouting to the tanks. The addition of NaOH resulted in the formation of asludge due to the precipitation of insoluble metal salts in a liquid portioncomposed of soluble salts such as sodium nitrate, nitrite and carbonate, andexcess NaOH. In some tanks a salt cake formed from the water soluble saltsdue to evaporation. The sludge portion of waste contains over 99% of theTRU elements and uranium, most of the 9OSr and some of the 99Tc while thesalt cake and liquid contain over 90% of the 137CS, the rest of the 9OSr and 99Tcand traces of the TRUs!

Considerable effort has been expanded in attempting to de;velopchemical methods for pre-treating the waste. Chemical pretreatment ofnuclear waste refers to sequence of separation processes used to partitionsuch waste into a small volume of high level waste for deep geologicdisposal and a large volume of low-level waste for disposal in near-surfacefacilities. The driving force for development of chemical treatment processesfor nuclear waste is the economic advantage of waste minimization asreflected in lower costs for near-surface disposal compared to the very highcost of disposing in a deep geologic repository.

The chemical pretFeatment of the water soluble salt portion of thewaste (which is about 75 volume %) involves primarily the removal of 137CSand 9OSr, which are the major sources of heat and radiation, and 99Tc, whichhas a high tendency to migrate if introduced into the soil or aquaticenvironment, The TRUs in the water soluble portion of the waste are lesserimportance because their concentration are very low but, nevertheless, ,insom~ salt portions of the waste that contain chelating agents, the TRUconcentration can exceed 100 nanocuries per gram. If a waste containsmore than 100 nCi of TRUs per gram of disposed form, it is classified as aTRU waste.

There are currently two !):'Pes of chemical systems that are underdevelopment for removal of 137~S and 9OSr from the water soluble salt waste,in the following referred to as alkaline supernate. The first system involvesthe use of inorganic ion exchange materials such as mixed alkali-transitionmetal ferrocyanides, insoluble salts of heteropolyacids, layered titanium andzirconium phosphates, crystalline silicotitanates (for cesium), and alkalimetal-antimony silicates, sodium titanates, synthetic zeolites, and manganasedioxide (for strontium) [3-6]. The other system involves the use of organicion exchange resins such as the resorcinol-formaldehyde resin (RF)developed at the Savannah River Laboratory and the commercially availableDuoliteTMCS-IOO and DuoliteTMCS-467 [7]. Although the inorganic ionexchangers, in general, exhibit strong retention of Cs and Sr from alkalinesupernate, in several cases they do not exhibit sufficient chemical stability,

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and capacity and reversibility of exchange. Often the two elements cannot beeluted or recovered from the inorganic sorbents. Therefore, the sorbent is thefinal waste form and a packed bed of the material cannot be regenerated.Also, none of the inorganic sorbents will remove TRUs.

Members of the Separation Chemistry Group of the ChemistryDivision of Argonne National Laboratory (ANL) together with members ofthe University of Tennessee, Department of Chemistry, have recentlydeveloped a new class of chelating ion exchange resins called DiphonixcQ) [8].The resin contains the geminally subsituted diphosphonic acid ligandchemically bonded to a styrene-based polymeric matrix. The Diphonix resinalso contains the strongly hydrophilic sulfonic acid acid group in the samepolymeric network together with the diphosophonic acid group, to providethe polymer with the required high hydrophilicity for fast kinetics of metalspecies uptake [9]. Because of the presence of both diphosphonic andsulfonic acid groups, the Diphonix resin can be regarded as a dualmechanism polymer, with a sulphonic acid cation exchange group allowingfor rapid access, mostly non-specific, of ions into the polymeric network,and the diphosphonic acid group responsible for specificity (recognition) fora number of metal cations. The Diphonix resin exhibits an extraordinarilystrong affinity for actinides, especially in the tetra- and hexavalent oxidationstates.9 Therefore, the resin has potential for applications in TRU removalfrom nuclear waste.

The Diphonix resin also exhibits a high affinity for Sr+. As expected,regular Diphonix has been shown to have a strong uptake of Sr from alkalinemedia. On the other hand, the uptake of Cs+ by the regular Diphonix resin isnot very high. The presence of a very large excess of sodium ions, as it isnormally the case in alkaline high-level waste, would likely prevent cesium

sorption [10].To efficiently, selectively and rapidly remove actinide species~ Sr and

Cs simultaneously from alkaline waSte solution, Chiarizia et al [11]. havebeen attached a functional groups exhibiting selectivity for Cs+ ions to theDiphonix polymer. As Cs+ selective functional groups phenolic -OH werechosen, based on their well known affinity for cesium. The new resincontaining diphosphonic acid groups (for actinides and Sr) and phenolicgroups (for Cs) has been named Diphonix-CS to emphasize its similarity tothe Diphonix resin and its specifity for Cs+ ion.

Usuda et al [12]. were successful in separating 137CS, 9OSr and 9OYby using strongly acidic cation exchange resins, MitsubishiChemical Industries Limited MCI GEL CK08Y~ packed into a fluoroplastictube of 1.5 mm inner diameter and 11 cm length, using mixtures of MeOHand HCI solution as eluent at elevated temperatures. Usuda [13] wasalso successful in separating the three elements by using strongly basic

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anion exchange resin made by the same company, MCI GEL CA08S, and thesame eluent at 90 DC.

Recently, a porous tertiary pyridine-type anion-exchange resin wassynthesized [14,15], and the distribution coefficients of some metal ions onthe resin were measured in various concentrations of HCI solution; it wasshown that the tested elements were separated into three groups (stronglyadsorbed, eluted with diluted HCI, and not adsorbed). Adsorption behaviourof uranium, americium, curium, and some lanthanide elements on tertiarypyridine-type anion exchange resin were also studied in MeOH -HCl mixedmedia and LiCI-HClmixed media [16]. The results were very attractive forthe separation of lanthanide and actinide; americium and curium which wereadsorbed on the resin at the solvent condition of 60% MeOH -conc. HCI,while lanthanides were not adsorbed.

In addition, in the previous report [17], the distribution coefficients ofsome fission products and related elements on porous tertiary pyridine-typeanion exchange resin were measured in various combinations ofMeoH -HCI mixed media, and the results were compared with distributioncoefficients in HCI solutions [14,15].

In the present work, based on the batch experiment results reported inthe previous work [17], column experiments were done by using tertiarypyridine-type resin and some types of amine anion exchange resin withMeOH -HCI mixed solution as eluent. The aim of this work is to investigatethe possibility of pyridine-type and some types of amine anion exchangeresin to be used for separating some fission product elements, especially137CS from 9OSr and 9OY in MeOH -HCl mixed solvents at room temperature.

EXPERIMENTAL PROCEDURES

Materials

Resin used in this experiment was the same as that used in previouswork, that is porous tertiary pyridine-type anion exchange resin made in ourlaboratory (beads diameter: 60 ).lm) [15,17]. In order to convert the resin tochloride-form, 10 g resin was immersed in 10 ml 6 M HCl solution for10 minutes, then it was poured into a glass funnel, and aspirator wasused to remove water from the resin. The reagents used in the present work[CH3OH, HCl, metal chloride compounds] were of analytical-grade, andsupplied by Wako Chemical Industries Ltd. The metal chloride compoundsexamined in the present work were dissolved into ion exchange water(conductivity was less than 2 J.lS) to attain 1 M metal ion solutions.

Resin used in Cs, Sr and Y column operation were primary amine,secondary amine, tertiary amine and quaternary ammonium anion exchange

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resin supplied by Asahi Chemical Industry, Co., Ltd. The chemical structures

of the resins are presented in Fig. 1. The resins were used in chloride form,

which were prepared the same way as for pyridine-type resin.

Column experiment

In this experiment, the glass column, 1.2 cm I.D. and 60 cm total

length was filled with pyridine-type anion exchange resin (resin bed lengthof 50 cm). The anion exchange resin packed in the column was pre-treated

with 5 M HCI solution to convert the resin into the chloride-form.

The solution of mixed tested elements containing 10 mM of each element

(amount of 10 ml) was fed into the resin packed in the column.These elements were eluted with 50% MeOH -0.5 M HCl mixed solution.To avoid the contamination of uranium in the analytical instrument for

common elements, uranium chromatography was separately conducted usingthe same column packed with the same resin, and the same type of eluents.

Thus, the solution of 100 mM U(VI) (amount of 10ml) was fed into thecolumn, and eluted by 50% MeOH -0.5 M HCl mixed solution.

The experiment was conducted at room temperature and feed solutionrate was 0.8 ml per minute. The effluents were sampled for every 10ml by

using fraction collector. The samples were determined using differentmethods of chemical analysis: Atomic Absorption Spectrophotometer model

SAS/727, Seiko Instruments Inc. Ltd. for alkali metal elements, UVNisible

Digital Spectrophotometer UVIDE(::-40 JASCO Corporation for uranium,and Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES)

model SPS 1500VR, Seiko Instruments Inc. Ltd. for other elements.In Cs+, Sr+, y3+ separation, the glass column, 0.8 cm I.D. and 105 cm

total length was filled with each type of amine anion exchange resin(resin bed length of 100 cm). The anion exchange resin packed in the columnwas pre-treated with 5 M HCl to convert the resin into chloride-form.

The solution of mixed tested elements containing 10 mM of each element

(amount of 10 ml) was fed into the resin packed in the column.These elements were eluted with 50% MeOH -0.5 M HCl mixed solution.

The eluent was taken by using fraction collector for each 5 mI.The concentrations of metal in the samples of eluent were determined using

Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES)model SPS I 500VR, Seiko Instruments Inc. Ltd.

RESULTS AND DISCUSSION

Based on the results of batch distribution coefficient (Dj ) experimentreported in previous work [17], column packed with pyridine-type resin

(resin bed size: <!> 1.2cm x 50cm) experiment was done for mainly testing the

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system in the separation of U(VI) from Mo(V), and for simultaneouslytesting the system in the group separation of all tested elements simulatingtypical fission products and nuclear materials. The results are shown inFig. 2. It is seen that using 50% MeOH -0.5 M HCI mixed media, themonovalent Cs(l) is firstly eluted; then divalent Sr(lI) and Ni(lI) are eluted;and trivalent rare earth elements [as represented by Y(III)] succeed.Thereafter higher valency ions of Zr(IV), Nb(V), U(VI), and Mo(V) areeluted, while palladium and lead are completely adsorbed by the anion-exchanger. It was found that a portion of Mo(V) remained in the resin bed,and eluted with 0.5 M pure aqueousHCI solution.

The elution curves of Fig. 2 also indicate that Cs(I), Sr(II), and Y(III)were slightly adsorbed by the anion exchanger in 50% MeOH -0.5 M HCI.These adsorptions were not detected by the batchwise study. From thiscolumn experiment with 50% MeOH -0.5 M HC I eluent, with Du(y!) = 1.3 atthe mixed solution composition, Dj value of the other elements can beexpected by using the following relationship:[18]

D.= (VJ J

v U(VIJ X Du(v,) (1)

where JIj and V U(VI) are effluent volume for metal j and U(VI), respectively.The results are presented in Table 1.

The sequence of elution curves from Cs(I) to Y(III) indicates the orderof anion exchange affinity, Cs(I) < Sr(lI} < Y(III) < Zr(IV), Nb(V)« U(VI).Apparently the results indicate that ion with higher charge is preferred by theion exchanger in this system, although some irregularities are seen.

In general, large anion shows large selectivity of anion exchangeresins; for example Cl04- > 1- > Br > Cl- > F-. The anions produced by ionassociation with Cl- ions have different sizes, depending on the size andcharge of the central cations. If we compare the adsorbed cations in the anionexchange resin, large charge cations probably form larger volumes of anions.Although it is well known that alkali and alkaline earth metal cations, unliketransition metal cations, do not form anion complexes with Cl- , such asY(III)CI4- , Sr(II)ClJ- , and Cs(I)CI2- , some retentions of Cs+, Cf+ and yJ+were seen in Fig. 2. This fact may be regarded as the physical sorption ratherthan complexation of their anionic chloride complexes. However it wouldbe more appropriate to consider the ion association of these metal ions withCl- in HCI -MeOH mixed solvent due to reduced dielectric constantof the medium.

The cations with higher valences, of Zr(IV), Nb(V), Mo(V), andU(VI), are oxo ions involving oxygen in the ions, and their apparent valencesof the positive charge are reduced as zrO2+, Nb02+, MoOJ+, and 0022+. It isinteresting that these ions show much larger selectivity than those expected

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from the apparent valences of the positive charges, and behave like the ionswith original positive charge without oxygen atoms in the ions. These highervalence cations are estimated to form higher valence anion complexes withchloride ions rather than the ion association as in the cases of alkali metal,alkaline earth, and lanthanide ions.

The results clarify that the system is usable for group separation ofalkali, alkaline earth, rare earth, transition metal, and actinide elementsgroups and uranium can be completely separated from alkali, alkalineearth, rare earth, and most transition metal elements by using the presentMeOH -HCl system. However, in order to completely separate U(VI) fromMo(V), it is necessary to apply further treatment by using a sufficiently longcolumn chromatography operation.

In the present system, palladium and lead ions are completelyadsorbed in the resin, and not eluted out. These ions can be eluted with thesolutions containing specialligands such as thiourea (H2NCSNHJ in case ofpalladium [19], and chelating agent~ such as ethylenediaminetetraacetic acid(EDT A) in case of lead [20].

In addition, column packed with amine-type resin (resin bed size:~ 0.8 cm x 100 cm) experiment was done for testing the system in theseparation of Cs+ from Sr+ and Y3+. The results of the experiment withprimary, secondary, tertiary and quaternary ammonium resins are shown inFigs. 3, 4, 5 and 6, respectively. As shown in Figs. 3 and 4, it is seen thatusing 50% MeOH -0.5 M HCI mixed media, the monovalent Cs(I) anddivalent Sr(II) are firstly eluted, then trivalent rare earth elements, Y(III),succeeds. Figures 5 and 6 show that using 50% MeOH -0.5 M HCl mixedmedia, the monovalent Cs(I) is firstly eluted, divalent Sr(II) is secondlyeluted, then trivalent rare earth elements, Y(III), succeeds.

The elution curves, especially Figs. 5 and 6 indicate some retention ofCs(I), Sr(II), and Y(III) in the column packed the anion exchanger wheneluted by 50% MeOH -0.5 M HCI. It is interesting that the differences inretention of the elements are higher in quaternary ammonium than intertiary, secondary and primary resins, although the differences in retentionof the elements in tertiary pyridine-type resin (Fig. 2) is higher than inquaternary ammonium resin. These results agree with those obtained byUsuda [21], however, using small column (1.5 mm I.D. and 14 cm lengthwith strongly basic anion exchange resin, MCI GEL CA08S), Usuda [13] hassuccessfully obtained high differences in retention of Cs(I), Sr(II) and Y(III)when eluted Cs+ and Sr+ + y3+ were eluted with 0.5 M HCI -90% EtOH and0.5 M HC1- 90% MeOH, respectively.

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CONCLUSIONS

Uranium is confirmed to be completely separated from alkali, alkalineearth, rare earth, and most transition metal elements by using the system.The differences in retention of the tested elements in the column experimentusing tertiary pyridine-type resin and quaternary ammonium resin are higherthan that obtained using tertiary, secondary and primary amine resin when50% MeOH -0.5 M HCI mixed solution is used as eluent. In such a system,tertiary pyridine-type and quaternary ammonium anion exchange resin canbe applied for separating y3+ from Sr+ and Cs+, if multistageschromatography is used.

Acknowlegments

The author acknowledges all those who have enabled him to completehis work. In particular, Prof. Yasuhiko FUll}. of Tokyo Institute ofTechnology who has given the author his experience, enthusiasm andencouragement and importantly his friendship during the courseof this work.

REFERENCES

M. Kubota, Y. Morita, I. Yamaguchi, T. Fujiwara, M. Watanabe, K.Mizoguchi, and R. Tatsugae, "Development of the Four GroupsPartitioning Process at JAERI," Proc. 2nd NUCEF IntI. Symp. NUCEF'98,210 (1999)

2, J.P. Bibler, R.M. Wallace and L.A. Bray, "Testing a Cesium Specific IonExchange Resin for Decontamination of Alkaline High-Activity Waste,"in Waste Management '90, vol. 2, R.G. Post Ed., 747 (1990)

3 R. Harjula, J. Lehto, E.H. Tusa, and A. Paavola, "Industrial ScaleRemoval of Cesium with Hexacyanoferrate Exchanger -ProcessRealization and Test Run," Nucl. Technol., 107,272(1994)

H. Mimura, T. Kobayashi, and K. Akiba, "Chromatographic Separationof Strontium and Cesium with Mixed Zeolite Column," J Nuc/. Sci.

Techno/., 32(1), 60(1995)

5 A.I. Bortun, L.N. Bortun, and A. Clearfield, "Evaluation of SyntheticInorganic Ion Exchangers for Cesium and Strontium Removed fromContaminated Groundwater and Wastewater," Solvent Extr. Ion Exch.,15(5),909(1997)

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6.

R.R. Brunson, D.F. Williams, W.D. Bond, D.E. Benker, F.R. Chatin, andE.D. Collins, "Removal of Cesium from Aluminum Decladding WastesGenerated in Irradiated Target Processing using a Fixed -Bed Columnof Resorcinol -Formaldehyde Resin," ORNL/TM-12708, Oak RidgeNational Laboratory (1994)

R. Chiarizia, E.P. Horwitz, S.D. Alexandratos, and M.l. Gula, "Diphonixreg-sign Resin: A Review oflts Properties and Applications," Sep. Sci.Techno!., 32(1-4), I (1997)

8 R. Chiarizia, E.P. Horwitz, and S.D. Alexandratos, "Metal Extraction byAlkyl Substituted Diphosphoinc Acid," Solvent Extr. Ion Exch.,12(1), 211 (1997)

9. R. Chiarizia, E.P. Horwitz, H. Diamond, R.C. Gatrone, S.D.Alexandratos, A.W. Trochimczuk, and D.W. Crick, "Argonne NationalLaboratory's Method for Low-level and Mixed Waste Minimization,"So/vent Extr. Ion Exch., 12(1), 211(1997)

10. R. Chiarizia, J.R. Ferraro, K.A.D'Arcy, and E.P. Horwitz, "Uptake ofMetal Ions by a New Chelating Ion Exchange Resin," So/vent Extr. IonExch., 13(6), 1063(1995)

11. R. Chiarizia, E.P. Horwitz, R.A. Beaivais, and S.D. Alexandratos,"Diphonix-cs: a Novel Combined Cesium and Strontium Selective inExchange Resin," So/vent Extr. Ion Exch., 16(3), 875(1997)

12. S. Usuda, N. Shinohara, H. Yoshikawa, "Single Column Ion ExchangeSeparation of the Transplutonium Elements from Uranium TargetsBombarded with Heavy Ions and Catcher Foils," J: Radioana/. Nuc/.Chern., 109(2),353 (1987)

13. S. Usuda, "Anion Exchange Behaviour of the TransplutoniumElementsin Hydrochloric Acid -Alcohol Media at Elevated Temperature," J:Radioanal. Nucl. Chern., 111(2),477 (1987)

14. M. Nogami, M. Aida, Y. Fujii, A. Maekawa, S. Ohe, H. Kawai, and M.Yoneda, "Ion Exchange Selectivity of Tertiary Pyridine-type AnionExchange Resin for Treatment of Spent Nuclear Fuels," Nuc/.Techno/.,115,293(1996)

15. M. Nogami, "Tertiary Pyridine-type Anion Exchange Resin for theTreatment of Spent Nuclear Fuel (in Japanese)," Doctor Thesis, TokyoInstitute of Technology, Tokyo, Japan (1996).

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16.

Rifaid M. Nur, M. Nogami, Y. Fujii, and T. Mitsugashira, "AdsorptionBehaviour of some Actinide and Lanthanide Elements on Pyridine-typeAnion Exchange Resin from Hydrochloric Acid Solution," J Nuc!. Sci.Techno!., 36 (8), 707(1999)

7. Rifaid M. Nur, M. Aida, S.H. Kim, Y. Fujii, and M. Nogami, "Pyridine-type Anion Exchange Resin Selectivity of some Metal Elements inMethanol -Hydrochloric Acid Mixed Media," J: Ion Exchange, 10(3),

89(1999)

18. H. Hatano, Introduction to High-speed Liquid Chromatography (inJapanese), KNRZAN, 102, 1 (1973)

19. Y.Z. Wei, M. Yamaguchi, M. Kumagai, Y. Takashima, T. Hoshikawa,and F. Kawamura, "Separation of Actinides from Simulated Spent FuelSolutions by an Advanced Ion-exchange Process," J Alloys Comp.,

271-273,693(1998)

20. M.A.M Kedziorek, A. Dupuy, A.C.M. Bourg, and F. Compere,"Leaching of Cd and Pb from a Polluted Soil During the Percolation ofEDT A: Laboratory Column Experiments Modeled with a Non-equilibrium Solubilization Step," Environ. Sci. Techno!., 32, 1609(1998)

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Table Estimation of Dj of some elements on pyridine-type resin in 0.5 MHCI -50% MeOH mixed solution, from column experiment result

CH2NH2Primary amine resin

CH2NHCH3Secondary amine resin

CH2N(CH3)2Tertiary amine resin

CH2N+(CH3hQuaternary ammonium resin

Fig. The chemical structures of the amine resins used in the Cs+, Sr+, y3-column experiment.

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Fig. 2. Elution curves of several cations from tertiary pyridine-type anion-exchange resin. Resin bed size: 1\11.2 cm x 50 cm.Eluent : 50% MeOH -0.5M HCI mixed solution.

Cs(I) :.A., Sr(II): "", Ni(II): *, Y(III): ., Zr(IV) : -,Nb(V) : I, Se(IV) :+, U(VI): 0, Mo(V): 0,and Co(Il) : X.

Fig. 3 Elution curves of Cs(I), Sr(II) and Y(III) by using columnpacked primary amine anion exchange resin. Eluent: 0.5 MHCI -50% MeOH.Cs(I) : -0 -, Sr(ll) : -0- , Y(III): -L\-

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Elution curves of Cs(I), Sr(II) and Y(III) by using columnpacked secondary amine anion exchange resin. Eluent: 0.5 MHCI -50% MeOH.

Cs(I) : -0 -.Sr(II) : -0- .Y(III): -A-

Elution curves of Cs(I), Sr(II) and Y(III) by using columnpacked tertiary amine anion exchange resin. Eluent: 0.5 MHCI -50% MeOH.Cs(I) : -0 -, Sr(II) : -0 -, Y(III) : -A -

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Fig. 6. Elution curves of Cs(I), Sr(lI) and Y(III} by using columnpacked quaternary ammonium anion exchange resin. Eluent: 0.5 MHCI -50% MeOH.Cs(I) : -0 -, Sr(lI) : -0 -, Y(III) : -~ -

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