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Sample records for ion-exchanged a-type zeolite

  1. Multicomponent liquid ion exchange with chabazite zeolites

    SciTech Connect

    Robinson, S.M.; Arnold, W.D. Jr.; Byers, C.W.

    1993-10-01

    In spite of the increasing commercial use of zeolites for binary and multicomponent sorption, the understanding of the basic mass-transfer processes associated with multicomponent zeolite ion-exchange systems is quite limited. This study was undertaken to evaluate Na-Ca-Mg-Cs-Sr ion exchange from an aqueous solution using a chabazite zeolite. Mass-transfer coefficients and equilibrium equations were determined from experimental batch-reactor data for single and multicomponent systems. The Langmuir isotherm was used to represent the equilibrium relationship for binary systems, and a modified Dubinin-Polyani model was used for the multicomponent systems. The experimental data indicate that diffusion through the microporous zeolite crystals is the primary diffusional resistance. Macropore diffusion also significantly contributes to the mass-transfer resistance. Various mass-transfer models were compared to the experimental data to determine mass-transfer coefficients. Effective diffusivities were obtained which accurately predicted experimental data using a variety of models. Only the model which accounts for micropore and macropore diffusion occurring in series accurately predicted multicomponent data using single-component diffusivities. Liquid and surface diffusion both contribute to macropore diffusion. Surface and micropore diffusivities were determined to be concentration dependent.

  2. A zeolite ion exchange membrane for redox flow batteries.

    PubMed

    Xu, Zhi; Michos, Ioannis; Wang, Xuerui; Yang, Ruidong; Gu, Xuehong; Dong, Junhang

    2014-03-01

    The zeolite-T membrane was discovered to have high proton permselectivity against vanadium ions and exhibit low electrical resistance in acidic electrolyte solutions because of its enormous proton concentration and small thickness. The zeolite membrane was demonstrated to be an efficient ion exchange membrane in vanadium redox flow batteries. PMID:24396857

  3. Ion exchange in a zeolite-molten chloride system

    SciTech Connect

    Woodman, R.H.; Pereira, C.

    1997-07-01

    Electrometallurgical treatment of spent nuclear fuel results in a secondary waste stream of radioactive fission products dissolved in chloride salt. Disposal plans include a waste form that can incorporate chloride forms featuring one or more zeolites consolidated with sintered glass. A candidate method for incorporating fission products in the zeolites is passing the contaminated salt over a zeolite column for ion exchange. To date, the molten chloride ion-exchange properties of four zeolites have been investigated for this process: zeolite A, IE95{reg_sign}, clinoptilolite, and mordenite. Of these, zeolite A has been the most promising. Treating zeolite 4A, the sodium form of zeolite A , with the solvent salt for the waste stream-lithium-potassium chloride of eutectic melting composition, is expected to provide a material with favorable ion-exchange properties for the treatment of the waste salt. The authors constructed a pilot-plant system for the ion-exchange column. Initial results indicate that there is a direct relationship between the two operating variable of interest, temperature, and initial sodium concentration. Also, the mass ratio has been about 3--5 to bring the sodium concentration of the effluent below 1 mol%.

  4. Immobilization of caesium-loaded ion exchange resins in zeolite-cement blends

    SciTech Connect

    Bagosi, S.; Csetenyi, L.J.

    1999-04-01

    In several countries, low-level radioactive waste immobilization strategies are based on cementitious materials. Water leaching of caesium (Cs)-loaded cemented ion exchange resin and the mechanism of Cs immobilization were studied in the cement-resin-zeolite (mainly clinoptilolite) system. Present work focuses on the reduction of significant Cs leaching (in terms of the total Cs adsorbed on the resin) by blending natural untreated and chemically treated zeolites to the cement. Addition of natural zeolites decreased Cs release by up to 70--75% (of the quantity originally bonded in the resin) in the course of a 3-year leaching period.

  5. Intensification of ammonia removal from waste water in biologically active zeolitic ion exchange columns.

    PubMed

    Almutairi, Azel; Weatherley, Laurence R

    2015-09-01

    The use of nitrification filters for the removal of ammonium ion from waste-water is an established technology deployed extensively in municipal water treatment, in industrial water treatment and in applications such as fish farming. The process involves the development of immobilized bacterial films on a solid packing support, which is designed to provide a suitable host for the film, and allow supply of oxygen to promote aerobic action. Removal of ammonia and nitrite is increasingly necessary to meet drinking water and discharge standards being applied in the US, Europe and other places. Ion-exchange techniques are also effective for removal of ammonia (as the ammonium ion) from waste water and have the advantage of fast start-up times compared to biological filtration which in some cases may take several weeks to be fully operational. Here we explore the performance of ion exchange columns in which nitrifying bacteria are cultivated, with the goal of a "combined" process involving simultaneous ion-exchange and nitrification, intensified by in-situ aeration with a novel membrane module. There were three experimental goals. Firstly, ion exchange zeolites were characterized and prepared for comparative column breakthrough studies for ammonia removal. Secondly effective in-situ aeration for promotion of nitrifying bacterial growth was studied using a number of different membranes including polyethersulfone (PES), polypropylene (PP), nylon, and polytetra-fluoroethylene (PTFE). Thirdly the breakthrough performance of ion exchange columns filled with zeolite in the presence of aeration and in the presence of nitrifying bacteria was determined to establish the influence of biomass, and aeration upon breakthrough during ammonium ion uptake. The methodology adopted included screening of two types of the naturally occuring zeolite clinoptilolite for effective ammonia removal in continuous ion-exchange columns. Next, the performance of fixed beds of clinoptilolite in the

  6. Biomineralization of hydroxyapatite in silver ion-exchanged nanocrystalline ZSM-5 zeolite using simulated body fluid.

    PubMed

    Kaur, Balwinder; Srivastava, Rajendra; Satpati, Biswarup; Kondepudi, Kanthi Kiran; Bishnoi, Mahendra

    2015-11-01

    Silver ion-exchanged nanocrystalline zeolite (Ag-Nano-ZSM-5) and silver ion-exchanged conventional zeolite (Ag-ZSM-5) were synthesized. Zeolites were incubated in simulated body fluid at 310K for different time periods to grow hydroxyapatite in their matrixes. Significant large amount of hydroxyapatite was grown in Ag-Nano-ZSM-5 matrix after incubation in simulated body fluid when compared to Ag-ZSM-5. The resultant material was characterized using X-ray diffraction, N2-adsorption, scanning/transmission electron microscopy, energy dispersive X-ray, and inductively coupled plasma analysis. Mechanical properties such as compressive modulus, compressive strength, and strain at failure of the parent materials were evaluated. Biocompatibility assays suggested that Ag-Nano-ZSM-5 and hydroxyapatite grown in Ag-Nano-ZSM-5 were compatible and did not impose any toxicity to RAW 264.7 cells macrophase and Caco2 cells suggesting considerable potential for biomedical applications such as bone implants. PMID:26255163

  7. Use of multi-transition-metal-ion-exchanged zeolite 13X catalysts in methane emissions abatement

    SciTech Connect

    Hui, K.S.; Chao, C.Y.H.; Kwong, C.W.; Wan, M.P.

    2008-04-15

    Methane is a potent greenhouse gas. It has a global warming potential (GWP) 23 times greater than carbon dioxide. Reducing methane emissions would lead to substantial economic and environmental benefits. This study investigated the performance of multi-transition-metal-(Cu, Cr, Ni, and Co)-ion-exchanged zeolite 13X catalysts in methane emissions abatement. The catalytic activity in methane combustion using multi-ion-exchanged catalysts was studied with different parameters including the molar percentage of metal loading, the space velocity, and the inlet methane concentration under atmospheric pressure and at a relatively low reaction temperature of 500 C. The performance of the catalysts was determined in terms of the apparent activation energy, the number of active sites of the catalyst, and the BET surface area of the catalyst. This study showed that multi-ion-exchanged catalysts outperformed single-ion-exchanged and acidified 13X catalysts and that lengthening the residence time led to a higher methane conversion percentage. The enhanced catalytic activity in the multi-ion-exchanged catalysts was attributed to the presence of exchanged transition ions instead of acid sites in the catalyst. The catalytic activity of the catalysts was influenced by the metal loading amount, which played an important role in affecting the apparent activation energy for methane combustion, the active sites, and the BET surface area of the catalyst. Increasing the amount of metal loading in the catalyst decreased the apparent activation energy for methane combustion and also the BET surface area of the catalyst. An optimized metal loading amount at which the highest catalytic activity was observed due to the combined effects of the various factors was determined. (author)

  8. Vectorial electron transport at ion-exchanged zeolite-Y-modified electrodes

    SciTech Connect

    Li, Z.; Mallouk, T.E.

    1987-01-29

    Chemically modified SnO/sub 2/ electrodes were prepared, using zeolite Y which had been ion-exchanged with a metal tris(bipyridyl) complex, M(bpy)/sub 3//sup 2 +/ (M = Ru, Os), metallocene cation, M(CpR)/sub 2//sup +/ or M(Cp)(CpR)/sup +/ (M = Co, Fe; Cp = eta/sub 5/sup -// cyclopentadienyl; R = -H, -CH/sub 3/, -NH/sub 2/, -COOCH/sub 3/, -CH/sub 2/N(CH/sub 3/)/sub 3/). The rate of charge transfer between the electrode and the metallocene contained within the zeolite is enhanced at least tenfold by adsorbing M(bpy)/sub 3//sup 2 +/ onto the zeolite surface. Both oxidation and reduction of the metallocene are facile if the potentials of the M(bpy)/sub 3//sup 2 +/ and M(CpR)/sub 2//sup +/ couples are matched, but only one of these processes occurs if the potentials are dissimilar. This behavior is attributed to a rapid electron-transfer cross reaction between the two complexes. The equilibrium potentials of the zeolite-bound M(CpR)/sub 2//sup +/0/ couples were found to be 300-600-mV positive of the corresponding potentials in polar organic solvents. The charge transport diffusion coefficient for Co(CpCH/sub 3/)/sub 2//sup +/0/ in zeolite Y, from linear sweep voltammetry, was found to be ca. 2 x 10/sup -10/ cm/sup 2//s.

  9. Radium-thorium disequilibrium and zeolite-water ion exchange in a Yellowstone hydrothermal environment

    NASA Astrophysics Data System (ADS)

    Sturchio, N. C.; Bohlke, J. K.; Binz, C. M.

    1989-05-01

    Whole rock samples of hydrothermally altered Biscuit Basin rhyolite from Yellowstone drill cores Y-7 and Y-8 were analyzed for 226Ra and 230Th to determine the extent of radioactive disequilibrium and its relation to the rates and mechanisms of element transport in the shallow portion of an active hydrothermal system. The ( 226Ra/230Th) activity ratios range from 0.73 to 1.46 and are generally correlated with Th-normalized Ba concentrations (Ba N). Values of ( 226Ra/230Th) and Ba N > 1 were found in samples containing large modal fractions of clinoptilolite; whereas values of ( 226Ra/230Th) and Ba N < 1 were found in samples containing large modal fractions of mordenite. Composition clinoptilolite and mordenite in these samples are consistent with ion exchange equilibrium between zeolites and coexisting thermal waters. Average K d mineral-waterBa values are 1.0·10 5 mL/g for clinoptilolite and 1.4·10 4 mL/g for mordenite. Apparent diffustvities through matrix porosity estimated for Ra and Ba range from ˜10 -12 to ˜10 -10 cm 2s -1 in thoroughly zeolitic rhyolite; these rates of diffusion are too low to account for the observed distance scale of ( 226Ra/230Th) disequilibrium. The correlated values of ( 226Ra /230Th) disequilibrium and Ba N represent zeolite-water ion exchange equilibrium that is caused by porous flow of water through the rock matrix and by the relatively rapid diffusion of cations within the zeolite lattices. A water flux of at least ˜2.5 ( cm water3/cm rock3) yr -1 is required to produce measurable ( 226Ra/230Th) disequilibrium, whereas at least ˜23 ( cm water3/cm rock3) yr -1 is r for the sample exhibiting the most extreme ( 226Ra/230Th) disequilibrium; these fluxes are much higher than those that can be inferred from net mass transfers of stable species. The zeolite-water ion exchange process appears to have been operating for at least 8000 yr in the environment of the Y-7 and Y-8 drill holes.

  10. Radium-thorium disequilibrium and zeolite-water ion exchange in a Yellowstone hydrothermal environment

    SciTech Connect

    Sturchio, N.C.; Bohlke, J.K. ); Binz, C.M. )

    1989-05-01

    Whole rock samples of hydrothermally altered Biscuit Basin rhyolite from Yellowstone drill cores Y-7 and Y-8 were analyzed for {sup 226}Ra and {sup 230}Th to determine the extent of radioactive disequilibrium and its relation to the rates and mechanisms of element transport in the shallow portion of an active hydrothermal system. The ({sup 226}Ra/{sup 230}Th) activity ratios range from 0.73 to 1.46 and are generally correlated with Th-normalized Ba concentrations (Ba{sub N}). Compositions of clinoptilolite and mordenite in these samples are consistent with ion exchange equilibrium between zeolites and coexisting thermal waters. Average K{sup Ba}{sub d mineral-water} values are 1.0 {center dot} 10{sup 5} mL/g for clinoptilolite and 1.4 {center dot} 10{sup 4} mL/g for mordenite. Apparent diffusivities through matrix porosity estimated for R and Ba range from {approximately}10{sup {minus}12} to {approximately}10{sup {minus}10} cm{sup 2} s{sup {minus}1} in thoroughly zeolitic rhyolite; these rates of diffusion are too low to account for the observed distance scale of ({sup 226}Ra/{sup 230}Th) disequilibrium. The correlated values of ({sup 226}Ra/{sup 230}Th) disequilibrium and Ba{sub N} represent zeolite-water ion exchange equilibrium that is caused by porous flow of water through the rock matrix and by the relatively rapid diffusion of cations within the zeolite lattices. A water flux of at least {approximately}2.5 (cm{sup 3}{sub water}/cm{sup 3}{sub rock}) yr{sup {minus}1} is required to produce measurable ({sup 226}Ra/{sup 230}Th) disequilibrium, whereas at least {approximately}23 (cm{sup 3}{sub water}/cm{sup 3}{sub rock}) yr{sup {minus}1} is required for the sample exhibiting the most extreme ({sup 226}Ra/{sup 230}Th) disequilibrium; these fluxes are much higher than those that can be inferred from net mass transfers of stable species.

  11. Thermodynamics of ion-exchange between Na{sup +}/Sr{sup 2+} solutions and the zeolite mineral clinoptilolite

    SciTech Connect

    Pabalan, R.T.; Bertetti, F.P.

    1994-12-31

    Ion-exchange experiments were conducted at 25{degrees}C between the zeolite mineral clinoptilolite and aqueous solutions of varying equivalent ratios of Na{sup +} and Sr{sup 2+} and total concentrations of 0.005, 0.05, and 0.5 N. The experiments were designed to investigate the effects of changes in total solution concentration and in the relative concentrations of exchangeable cations on the following ion-exchange equilibrium: Sr{sup 2+} + 2NaZ {r_reversible} SrZ{sub 2} + 2Na{sup +}. Using the isotherm data at 0.05 N solution concentration, a thermodynamic model for the ion-exchange reaction was derived using a Margules formulation for the activity coefficients of zeolite components and the Pitzer ion-interaction approach for activity coefficients of aqueous ions. The results of the forward experiments showed that the ion-exchange isotherm strongly depends on the total solution concentration. Additional experiments demonstrated that the above ion-exchange reaction is reversible. The derived equilibrium constant, K, and Gibbs energy of ion-exchange, {Delta}G{sup 0}, are equal to 0.321{+-}0.021 and 2,820 {+-} 170 J/mol, respectively. Using thermodynamic parameters derived from the 0.05 N isotherm experiment, the model was used to predict isotherm values at 0.005 and 0.5 N, which showed excellent agreement with measured data. Because the thermodynamic model used in this study can be easily extended to ternary and more complicated mixtures, it may be useful for modeling ion-exchange equilibria in multicomponent geochemical systems.

  12. Ion exchange and dehydration experimental studies of clinoptilolite: Implications to zeolite dating

    SciTech Connect

    WoldeGabriel, G.

    1995-02-01

    Variable effects were noted on the argon (Ar) and potassium (K) contents of clinoptilolite fractions used in ion-exchange and dehydration experiments. The K contents of clinoptilolite fractions were differently affected during cation exchange with Ca-, Cs-, K-, and Na-chloride solutions. Ar was generally less affected during these experiments, except for a Na-clinoptitolite fraction exchanged for five days. Loss of Ar during organic heavy-liquid treatment and cleaning using acetone and deionized water does occur, as indicated by comparing the amounts of radiogenic Ar of treated and untreated fractions. Moreover, a regular decrease in radiogenic Ar contents was noted in clinoptilolite fractions during dehydration experiments at different temperatures for 16 hours. Comparable losses do not occur from saturated samples that were heated in 100 C for more than five months. Water appears to play a vital role in stabilizing the clinoptilolite framework structure and in the retention of Ar. The radiogenic Ar depletion pattern noted in clinoptilolite fractions dehydrated in unsaturated environment at different temperatures is similar to variations in the amount of radiogenic Ar observed in clinoptilolite samples from the unsaturated zone of an altered tuff. These results can be used to evaluate the extent of zeolitic water (and hence Ar) retention in unsaturated geologic settings. The utility of alkali zeolites (e.g., phillipsite, clinoptilolite, and mordenite) from low-temperature, open-hydrologic alteration as potential dateable minerals was evaluated using the K/Ar method as part of the Yucca Mountain Site Characterization Project, which is evaluating Yucca Mountain, Nevada, as a potential high-level radioactive waste repository site.

  13. Electron and energy transfer as probes of interparticle ion-exchange reactions in zeolite Y

    SciTech Connect

    Brigham, E.S.; Snowden, P.T.; Kim, Y.I.; Mallouk, T.E. )

    1993-08-19

    Photoinduced electron transfer and energy transfer reactions of tris(2,2[prime]-bipyridyl)ruthenium(II) (Ru(bpy)[sub 3][sup 2+]) with methylviologen (MV[sup 2+]) and tris(2,2[prime]-bipyridyl)osmium(II) (Os(bpy)[sub 3][sup 2+]) ion-exchanged onto/into separate zeolite Y particles were studied by emission spectroscopy. The kinetics of interparticle exchange were probed by observing the quenching of the MLCT excited state of-Ru(bpy)[sub 3][sup 2+] by mobile MV[sup 2+] or OS(bpy)[sub 3][sup 2+] ions. The exchange reactions occur on time scales of seconds to hours, depending on the ionic strength of the surrounding medium. The time-dependent luminescence data were fitted to a dispersed kinetics model, from which average rate constants for the exchange reactions could be extracted. Time constants for interparticle exchange of MV[sup 2+] and Os(bpy)[sub 3][sup 2+] ions, in the range 10[sup 3]-10[sup 5] s at electrolyte concentrations of 0.1-3 mM, are significantly longer than the time scales (10[sup [minus]7]-10[sup 1] s) of most electrochemical and photochemical intrazeolitic reactions involving these and similar electroactive ions. These results argue for reaction mechanisms that invoke intrazeolite electron transfer, rather than exchange of electroactive ions followed by solution-phase electron transfer, in these systems. 25 refs., 6 figs., 1 tab.

  14. Investigation of phosphate removal using sulphate-coated zeolite for ion exchange.

    PubMed

    Choi, Jae-Woo; Hong, Seok-Won; Kim, Dong-Ju; Lee, Sang-Hyup

    2012-01-01

    Sulphate-coated zeolite (SCZ) was characterized and employed for the removal of phosphate from aqueous solutions using both batch and column tests. Batch experiments were conducted to assess the sulphate dilution ratio, reaction time for coating, surface washing and calcination temperature during the synthesis of SCZ. Langmuir isotherm and pseudo-first-order models were suitable to explain the sorption characteristics of phosphate onto the SCZ. Equilibrium tests showed that SCZ was capable of removing phosphate, with a maximum binding energy beta = 30.2 mg g(-1), compared to other adsorbents, such as activated alumina and ion exchange resin. The Thomas model was applied to the adsorption of phosphate to predict the breakthrough curves and the parameters of a column test. The model was found to be suitable for describing the adsorption process of the dynamic behaviour of the SCZ column. The total adsorbed quantity and equilibrium uptake ofphosphate related to the effluent volumes were determined by evaluating the breakthrough curves obtained under the allowed conditions. The results of batch and column experiments, as well as the low cost of the adsorbent, suggested that SCZ could be used as an adsorbent for the efficient and cost-effective removal of phosphate from aqueous solution. PMID:23393974

  15. Ammonium Ion Exchanged Zeolite for Laser Desorption/Ionization Mass Spectrometry of Phosphorylated Peptides

    PubMed Central

    Yang, Mengrui; Fujino, Tatsuya

    2015-01-01

    α-Cyano-4-hydroxycinnamic acid (CHCA), an organic matrix molecule for matrix-assisted laser desorption/ionization mass spectrometry, was adsorbed to NH4+-type zeolite surface, and this new matrix was used for the detection of low-molecular-weight compounds. It was found that this matrix could simplify the mass spectrum in the low-molecular-weight region and prevent interference from fragments and alkali metal ion adducted species. CHCA adsorbed to NH4+-type ZSM5 zeolite (CHCA/NH4ZSM5) was used to measure atropine and aconitine, two toxic alkaloids in plants. In addition, CHCA/NH4ZSM5 enabled us to detect phosphorylated peptides; peaks of the protonated peptides had higher intensities than the peaks observed using CHCA only. PMID:26448749

  16. Perturbed angular correlation study of the ion exchange of indium into silicalite zeolites

    NASA Astrophysics Data System (ADS)

    Ramallo-López, J. M.; Requejo, F. G.; Rentería, M.; Bibiloni, A. G.; Miró, E. E.

    1999-09-01

    Two indium-containing silicalite zeolites (In/H ZSM5) catalysts prepared by wet impregnation and ionic exchange were characterized by the Perturbed Angular Correlation (PAC) technique using 111In as probe to determine the nature of the indium species. Some of these species take part in the catalytic reaction of the selective reduction (SCR) of NOx with methane. PAC experiments were performed at 500ºC in air before and after reduction reoxidation treatments on the catalysts in order to determine the origin of the different hyperfine interactions and then the degree of ionic exchange. Complementary catalytic activity characterizations were also performed. PAC experiments performed on the catalyst obtained by wet impregnation showed that all In-atoms form In2O3 crystallites while almost 70% of In-atoms form In2O3 in the catalyst obtained by ionic exchange. The PAC experiments of both catalysts performed after the reduction reoxidation treatment revealed the presence of two hyperfine interactions, different from those corresponding to indium in In2O3. These hyperfine interactions should be associated to disperse In species responsible of the catalytic activity located in the ionic exchange-sites of the zeolites.

  17. Adsorption of hydrofluorocarbons HFC-134 and HFC-134A on X and Y zeolites: Effect of ion-exchange on selectivity and heat of adsorption

    SciTech Connect

    Savitz, S.; Siperstein, F.R.; Huber, R.; Tieri, S.M.; Gorte, R.J.; Myers, A.L.; Grey, C.P.; Corbin, D.R.

    1999-09-30

    Adsorption isotherms and heats of adsorption were measured for HFC-134 (1,1,2,2-tetrafluoroethane) and HFC-134a (1,1,1,2-tetrafluoroethane) on a series of ion-exchanged (H, Li, Na, Rb, Cs) faujasites using volumetric and calorimetric techniques. The species and number of ions present in the zeolite strongly influence the heats of adsorption and the preferential adsorption of HFC-134 compared to HFC-134a. The selectivity is considerably higher in X than in Y zeolites because of the larger number of nonframework ions in X zeolites. The saturation capacity is six molecules per supercavity for both HFCs. The differences in observed heats of adsorption (except for RbX) can be explained by reasonable and consistent values of dispersion and ion-dipole electrostatic energies. The high selectivities for NaX and RbX indicate that either zeolite would be highly effective for gas separation.

  18. Equilibrium study of selected divalent d-electron metals adsorption on A-type zeolite.

    PubMed

    Majdan, Marek; Pikus, Stanisław; Kowalska-Ternes, Monika; Głdysz-Płaska, Agnieszka; Staszczuk, Piotr; Fuks, Leon; Skrzypek, Henryk

    2003-06-15

    The objective of the presented study was to investigate the adsorption of Cu, Co, Mn, Zn, Cd and Mn on A-type zeolite. The isotherms for adsorption of metals from their nitrates were registered. The following adsorption constants K of metals were found: 162,890, 124,260, 69,025, 16,035, 10,254, and 151 [M(-1)] for Cu, Co, Mn, Zn, Cd, and Ni, respectively, for the concentration range 10(-4)-10(-3) M. On the other hand, the investigation of pH influence on the distribution constants of metals showed that the adsorption of metals proceeds essentially through an ion-exchange process, surface hydrolysis, and surface complexation. The supplementary results from DRIFT, scanning electron microscopy, and X-ray diffraction methods confirmed the presumption about the possible connection between the electronic structure of divalent ions and their adsorption behavior, showing that ions with d5 and d10 configurations such as Mn2+, Zn2+, Cd2+, with much weaker hydrolytic properties than Cu2+ and Ni2+, strongly interact with the zeolite framework and therefore their affinity to the zeolite phase is much stronger when compared with that of the Ni2+ ion, but at the same time not as strong as the affinity of the Cu2+ ion, the latter forming a new phase during the interaction with zeolite framework. For Zn2+, during inspection of the correlation between the proton concentration H/Al and zinc concentration Zn/Al on the zeolite surface, the formation of the surface complex [triple bond]S-OZn(OH) was proposed. A correlation between the heterogeneity of proton concentrations H/Al on Me-zeolite surfaces and the hydrolysis constants pKh of Me2+ ions was found. PMID:16256612

  19. Adsorption behaviors of thiophene, benzene, and cyclohexene on FAU zeolites: Comparison of CeY obtained by liquid-, and solid-state ion exchange

    NASA Astrophysics Data System (ADS)

    Qin, Yucai; Mo, Zhousheng; Yu, Wenguang; Dong, Shiwei; Duan, Linhai; Gao, Xionghou; Song, Lijuan

    2014-02-01

    Cerium containing Y zeolites were prepared by liquid- (L-CeY) and solid- (S-CeY) state ion exchange from NaY and HY, respectively. The structural and textural properties were characterized by XRD and N2 adsorption, and acidity properties were characterized by NH3 temperature-programmed desorption (NH3-TPD) and in situ FTIR spectrum of chemisorbed pyridine (in situ Py-FTIR). Furthermore, the single component adsorption and multi-component competitive adsorption behavior of thiophene, benzene and cyclohexene on those zeolites have also been studied by using vapor adsorption isotherms, solution adsorption breakthrough curves, thermogravimetry and derivative thermogravimetry (TG/DTG), frequency response (FR) and in situ FTIR techniques. The results indicate that the primary adsorption mode of benzene is simply micropore filling process, but the nature of effect of aromatics on selective adsorption of thiophene is competitive adsorption. The strong chemical adsorptions and protonization reactions of thiophene and cyclohexene occur upon the Brönsted acid sites of the HY and L-CeY zeolites, and the preferable acid catalytic protonization reactions of olefins hinder the further adsorption of sulfur compounds.

  20. Physicochemical and catalytic characteristics of La-H-ZSM-5 zeolite in converting dimethyl ether to the mixtures of gasoline hydrocarbons: Effect of ion exchange conditions

    NASA Astrophysics Data System (ADS)

    Kitaev, L. E.; Bukina, Z. M.; Yushchenko, V. V.; Ionin, D. A.; Kolesnichenko, N. V.; Khadzhiev, S. N.

    2014-03-01

    The effect of the manner and conditions of introducing lanthanum cations into NH4-ZSM-5 zeolite on the properties of catalysts for the conversion of dimethyl ether into the mixtures of gasoline hydrocarbons is studied. The physicochemical properties of synthesized catalysts are studied by means of temperature-programmed ammonia desorption, the adsorption of benzene, atomic absorption spectroscopy, differential scanning calorimetry, and thermogravimetry. It is shown that the degree to which lanthanum cations are replaced by ammonium cations both depends on the conditions of ion exchange in the zeolite and affects its acidity spectrum and the selectivity of the formation of paraffin hydrocarbons with isostructure. It is concluded that an increase in the amount of introduced lanthanum leads to an increase in the content of iso-paraffins from 69 to 76 wt % and a decrease in the content of aromatic hydrocarbons from 10.5 to 5.5 wt % and that of durene from 1.5 to 0.2 wt % in the products.

  1. Atomic sites and stability of Cs+ captured within zeolitic nanocavities

    PubMed Central

    Yoshida, Kaname; Toyoura, Kazuaki; Matsunaga, Katsuyuki; Nakahira, Atsushi; Kurata, Hiroki; Ikuhara, Yumi H.; Sasaki, Yukichi

    2013-01-01

    Zeolites have potential application as ion-exchangers, catalysts and molecular sieves. Zeolites are once again drawing attention in Japan as stable adsorbents and solidification materials of fission products, such as 137Cs+ from damaged nuclear-power plants. Although there is a long history of scientific studies on the crystal structures and ion-exchange properties of zeolites for practical application, there are still open questions, at the atomic-level, on the physical and chemical origins of selective ion-exchange abilities of different cations and detailed atomic structures of exchanged cations inside the nanoscale cavities of zeolites. Here, the precise locations of Cs+ ions captured within A-type zeolite were analyzed using high-resolution electron microscopy. Together with theoretical calculations, the stable positions of absorbed Cs+ ions in the nanocavities are identified, and the bonding environment within the zeolitic framework is revealed to be a key factor that influences the locations of absorbed cations. PMID:23949184

  2. Treatment technology for transuranic waste streams: Cementation, vitrification, and incineration testing for the treatment of spent ion exchange media

    SciTech Connect

    Place, B.G.

    1992-04-01

    This document reports the results of testing of spent ion exchange media pretreatment technologies. Emphasis of the testing activities has been on screening pretreatment technologies, such as drying and emulsification, which are compatible with vitrification, cementation, and incineration. Ion exchange media tested for cementation and incineration pretreatment technologies were typical organic ion exchange resins and inorganic zeolites. The ion exchange medium tested for vitrification pretreatment technologies was inorganic zeolite. The results of testing activities are discussed in detail in this report.

  3. [Ion specificity during ion exchange equilibrium in natural clinoptilolite].

    PubMed

    He, Yun-Hua; Li, Hang; Liu, Xin-Min; Xiong, Hai-Ling

    2015-03-01

    Zeolites have been widely applied in soil improvement and environment protection. The study on ion specificity during ion exchange equilibrium is of important significance for better use of zeolites. The maximum adsorption capacities of alkali ions during ion exchange equilibrium in the clinoptilolite showed obvious specificity. For alkali metal ions with equivalent valence, the differences in adsorption capacity increased with the decrease of ionic concentration. These results cannot be well explained by the classical theories including coulomb force, ionic size, hydration, dispersion force, classic induction force and surface complexation. We found that the coupling of polarization effects resulted from the quantum fluctuation of diverse alkali metal ions and electric field near the zeolite surface should be the primary reason for specific ion effect during ion exchange in zeolite. The result of this coupling effect was that the difference in the ion dipole moment increased with the increase of surface potential, which further expanded the difference in the adsorption ability between zeolite surface and ions, resulting in different ion exchange adsorption ability at the solid/liquid interface. Due to the high surface charge density of zeolite, ionic size also played an important role in the distribution of ions in the double diffuse layer, which led to an interesting result that distinct differences in exchange adsorption ability of various alkali metal ions were only detected at high surface potential (the absolute value was greater than 0.2 V), which was different from the ion exchange equilibrium result on the surface with low charge density. PMID:25929073

  4. Material Exhibiting Efficient CO2 Adsorption at Room Temperature for Concentrations Lower Than 1000 ppm: Elucidation of the State of Barium Ion Exchanged in an MFI-Type Zeolite.

    PubMed

    Itadani, Atsushi; Oda, Akira; Torigoe, Hiroe; Ohkubo, Takahiro; Sato, Mineo; Kobayashi, Hisayoshi; Kuroda, Yasushige

    2016-04-01

    Carbon dioxide (CO2) gas is well-known as a greenhouse gas that leads to global warming. Many efforts have been made to capture CO2 from coal-fired power plants, as well as to reduce the amounts of excess CO2 in the atmosphere to around 400 ppm. However, this is not a simple task, particularly in the lower pressure region than 1000 ppm. This is because the CO2 molecule is chemically stable and has a relatively low reactivity. In the present study, the CO2 adsorption at room temperature on MFI-type zeolites exchanged with alkaline-earth-metal ions, with focus on CO2 concentrations <1000 ppm, was investigated both experimentally and by calculation. These materials exhibited a particularly efficient adsorption capability for CO2, compared with other presented samples, such as the sodium-form and transition-metal ion-exchanged MFI-type zeolites. Ethyne (C2H2) was used as a probe molecule. Analyses were carried out with IR spectroscopy and X-ray absorption, and provided significant information regarding the presence of the M(2+)-O(2-)-M(2+) (M(2+): alkaline-earth-metal ion) species formed in the samples. It was subsequently determined that this species acts as a highly efficient site for CO2 adsorption at room temperature under very low pressure, compared to a single M(2+) species. A further advantage is that this material can be easily regenerated by a treatment, e.g., through the application of the temperature swing adsorption process, at relatively low temperatures (300-473 K). PMID:26990497

  5. Ion exchange phenomena

    SciTech Connect

    Bourg, I.C.; Sposito, G.

    2011-05-01

    Ion exchange phenomena involve the population of readily exchangeable ions, the subset of adsorbed solutes that balance the intrinsic surface charge and can be readily replaced by major background electrolyte ions (Sposito, 2008). These phenomena have occupied a central place in soil chemistry research since Way (1850) first showed that potassium uptake by soils resulted in the release of an equal quantity of moles of charge of calcium and magnesium. Ion exchange phenomena are now routinely modeled in studies of soil formation (White et al., 2005), soil reclamation (Kopittke et al., 2006), soil fertilitization (Agbenin and Yakubu, 2006), colloidal dispersion/flocculation (Charlet and Tournassat, 2005), the mechanics of argillaceous media (Gajo and Loret, 2007), aquitard pore water chemistry (Tournassat et al., 2008), and groundwater (Timms and Hendry, 2007; McNab et al., 2009) and contaminant hydrology (Chatterjee et al., 2008; van Oploo et al., 2008; Serrano et al., 2009).

  6. Composite ion exchange materials

    SciTech Connect

    Amarasinghe, S.; Zook, L.; Leddy, J.

    1994-12-31

    Composite ion exchange materials can be formed by sorbing ion exchange polymers on inert, high surface area substrates. In general, the flux of ions and molecules through these composites, as measured electrochemically, increases as the ratio of the surface area of the substrate increases relative to the volume of the ion exchanger. This suggests that fields and gradients established at the interface between the ion exchanger and substrate are important in determining the transport characteristics of the composites. Here, the authors will focus on composites formed with a cation exchange polymer, Nafion, and two different types of microbeads: polystyrene microspheres and polystyrene coated magnetic microbeads. For the polystyrene microbeads, scanning electron micrographs suggest the beads cluster in a self-similar manner, independent of the bead diameter. Flux of Ru(NH3)63+ through the composites was studied as a function of bead fraction, bead radii, and fixed surface area with mixed bead sizes. Flux was well modeled by surface diffusion along a fractal interface. Magnetic composites were formed with columns of magnetic microbeads normal to the electrode surface. Flux of Ru(NH3)63+ through these composites increased exponentially with bead fraction. For electrolyses, the difference in the molar magnetic susceptibility of the products and reactants, Dcm, tends to be non-zero. For seven redox reactions, the ratio of the flux through the magnetic composites to the flux through a Nafion film increases monotonically with {vert_bar}Dcm{vert_bar}, with enhancements as large as thirty-fold. For reversible species, the electrolysis potential through the magnetic composites is 35 mV positive of that for the Nafion films.

  7. ZEOLITES: EFFECTIVE WATER PURIFIERS

    EPA Science Inventory

    Zeolites are known for their adsorption, ion exchange and catalytic properties. Various natural zeolites are used as odor and moisture adsorbents and water softeners. Due to their acidic nature, synthetic zeolites are commonly employed as solid acid catalysts in petrochemical ind...

  8. Ion exchange technology assessment report

    SciTech Connect

    Duhn, E.F.

    1992-01-01

    In the execution of its charter, the SRS Ion Exchange Technology Assessment Team has determined that ion exchange (IX) technology has evolved to the point where it should now be considered as a viable alternative to the SRS reference ITP/LW/PH process. The ion exchange media available today offer the ability to design ion exchange processing systems tailored to the unique physical and chemical properties of SRS soluble HLW's. The technical assessment of IX technology and its applicability to the processing of SRS soluble HLW has demonstrated that IX is unquestionably a viable technology. A task team was chartered to evaluate the technology of ion exchange and its potential for replacing the present In-Tank Precipitation and proposed Late Wash processes to remove Cs, Sr, and Pu from soluble salt solutions at the Savannah River Site. This report documents the ion exchange technology assessment and conclusions of the task team.

  9. Ion exchange technology assessment report

    SciTech Connect

    Duhn, E.F.

    1992-12-31

    In the execution of its charter, the SRS Ion Exchange Technology Assessment Team has determined that ion exchange (IX) technology has evolved to the point where it should now be considered as a viable alternative to the SRS reference ITP/LW/PH process. The ion exchange media available today offer the ability to design ion exchange processing systems tailored to the unique physical and chemical properties of SRS soluble HLW`s. The technical assessment of IX technology and its applicability to the processing of SRS soluble HLW has demonstrated that IX is unquestionably a viable technology. A task team was chartered to evaluate the technology of ion exchange and its potential for replacing the present In-Tank Precipitation and proposed Late Wash processes to remove Cs, Sr, and Pu from soluble salt solutions at the Savannah River Site. This report documents the ion exchange technology assessment and conclusions of the task team.

  10. UTILITY OF ZEOLITES IN HAZARDOUS METAL REMOVAL FROM WATER

    EPA Science Inventory

    Zeolites are well known for their ion exchange, adsorption and acid catalysis properties. Different inorganic pollutants have been removed from water at room temperature by using synthetic zeolites. Zeolite Faujasite Y has been used to remove inorganic pollutants including arseni...

  11. Radionuclide Leaching from Organic Ion Exchange Resin

    SciTech Connect

    Delegard, C.H.; Rinehart, D.E.

    1999-04-02

    Laboratory tests were performed to examine the efficacy of leach treatments for decontaminating organic ion exchange resins (OIER), which have been found in a number of samples retrieved from K East Basin sludge. Based on process records, the OIER found in the K Basins is a mixed-bet strong acid/strong base material marketed as Purolite{trademark} NRW-037. Radionuclides sorbed or associated with the OIER can restrict its disposal to the Environmental Restoration Disposal Facility (ERDF). The need for testing to support development of a treatment process for K Basin sludge has been described in Section 4.2 of ''Testing Strategy to Support the Development of K Basins Sludge Treatment Process'' (Flament 1998). To help understand the effects of anticipated OIER elutriation and washing, tests were performed with well-rinsed OIER material from K East Basin floor sludge (sample H-08 BEAD G) and with well-rinsed OIER having approximately 5% added K East canister composite sludge (sample KECOMP). The rinsed resin-bearing material also contained the inorganic ion exchanger Zeolon-900{trademark}, a zeolite primarily composed of the mineral mordenite. The zeolite was estimated to comprise 27 weight percent of the dry H-08 BEAD G material.

  12. Ion-exchange hollow fibers

    NASA Technical Reports Server (NTRS)

    Rembaum, A.; Yen, S. P. S.; Klein, E. (Inventor)

    1976-01-01

    An ion-exchange hollow fiber is prepared by introducing into the wall of the fiber polymerizable liquid monomers, and polymerizing the monomers therein to form solid, insoluble, crosslinked, ion-exchange resin particles which embed in the wall of the fiber. Excess particles blocking the central passage or bore of the fiber are removed by forcing liquid through the fiber. The fibers have high ion-exchange capacity, a practical wall permeability and good mechanical strength even with very thin wall dimensions. Experimental investigation of bundles of ion-exchange hollow fibers attached to a header assembly have shown the fiber to be very efficient in removing counterions from solution.

  13. Ion-exchange hollow fibers

    NASA Technical Reports Server (NTRS)

    Rembaum, Alan (Inventor); Yen, Shiao-Ping S. (Inventor); Klein, Elias (Inventor)

    1980-01-01

    An ion-exchange hollow fiber is prepared by introducing into the wall of the fiber polymerizable liquid monomers, and polymerizing the monomers therein to form solid, insoluble, cross-linked, ion-exchange resin particles which embed in the wall of the fiber. Excess particles blocking the central passage or bore of the fiber are removed by forcing liquid through the fiber. The fibers have high ion-exchange capacity, a practical wall permeability and good mechanical strength even with very thin wall dimensions. Experimental investigation of bundles of ion-exchange hollow fibers attached to a header assembly have shown the fiber to be very efficient in removing counterions from solution.

  14. Ion-exchange hollow fibers

    NASA Technical Reports Server (NTRS)

    Rembaum, Alan (Inventor); Yen, Shiao-Ping S. (Inventor); Klein, Elias (Inventor)

    1977-01-01

    An ion-exchange hollow fiber is prepared by introducing into the wall of the fiber polymerizable liquid monomers, and polymerizing the monomers therein to form solid, insoluble, cross-linked, ion-exchange resin particles which embed in the wall of the fiber. Excess particles blocking the central passage or bore of the fiber are removed by forcing liquid through the fiber. The fibers have high ion-exchange capacity, a practical wall permeability and good mechanical strength even with very thin wall dimensions. Experimental investigation of bundles of ion-exchange hollow fibers attached to a header assembly have shown the fiber to be very efficient in removing counterions from solution.

  15. Biological Ion Exchanger Resins

    PubMed Central

    Damadian, Raymond; Goldsmith, Michael; Zaner, K. S.

    1971-01-01

    Biological selectivity is shown to vary with medium osmotic strength and temperature. Selectivity reversals occur at 4°C and at an external osmolality of 0.800 indicating that intracellular hydration and endosolvent (intracellular water) structure are important determinants in selectivity. Magnetic resonance measurements of line width by steady-state nuclear magnetic resonance (NMR) indicate a difference in the intracellular water signal of 16 Hz between the K form and Na form of Escherichia coli, providing additional evidence that changes in the ionic composition of cells are accompanied by changes in endosolvent structure. The changes were found to be consistent with the thermodynamic and magnetic resonance properties of aqueous electrolyte solutions. Calculation of the dependence of ion-pairing forces on medium dielectric reinforces the role of endosolvent structure in determining ion exchange selectivity. PMID:4943653

  16. Electrically switched ion exchange

    SciTech Connect

    Lilga, M.A.; Schwartz, D.T.; Genders, D.

    1997-10-01

    A variety of waste types containing radioactive {sup 137}Cs are found throughout the DOE complex. These waste types include water in reactor cooling basins, radioactive high-level waste (HLW) in underground storage tanks, and groundwater. Safety and regulatory requirements and economics require the removal of radiocesium before these wastes can be permanently disposed of. Electrically Switched Ion Exchange (ESIX) is an approach for radioactive cesium separation that combines IX and electrochemistry to provide a selective, reversible, and economic separation method that also produces little or no secondary waste. In the ESIX process, an electroactive IX film is deposited electrochemically onto a high-surface area electrode, and ion uptake and elution are controlled directly by modulating the potential of the film. For cesium, the electroactive films under investigation are ferrocyanides, which are well known to have high selectivities for cesium in concentrated sodium solutions. When a cathode potential is applied to the film, Fe{sup +3} is reduced to the Fe{sup +2} state, and a cation must be intercalated into the film to maintain charge neutrality (i.e., Cs{sup +} is loaded). Conversely, if an anodic potential is applied, a cation must be released from the film (i.e., Cs{sup +} is unloaded). Therefore, to load the film with cesium, the film is simply reduced; to unload cesium, the film is oxidized.

  17. Ion exchange - Simulation and experiment

    NASA Technical Reports Server (NTRS)

    Herrmann, Cal C.; Finn, John E.

    1991-01-01

    A FORTRAN program for simulating multicomponent adsorption by ion-exchange resins was adapted for use as both an ASPEN-callable module and as a free-standing simulator of the ion-exchange bed. Four polystyrene-divinylbenzene sulfonic acid resins have been characterized for three principal ions. It is concluded that a chelating resin appears appropriate as a heavy-metal trap. The same ASPEN-callable module is used to model this resin when Wilson parameters can be obtained.

  18. Vitrification of ion exchange resins

    DOEpatents

    Cicero-Herman, Connie A.; Workman, Rhonda Jackson

    2001-01-01

    The present invention relates to vitrification of ion exchange resins that have become loaded with hazardous or radioactive wastes, in a way that produces a homogenous and durable waste form and reduces the disposal volume of the resin. The methods of the present invention involve directly adding borosilicate glass formers and an oxidizer to the ion exchange resin and heating the mixture at sufficient temperature to produce homogeneous glass.

  19. UTILITY OF ZEOLITES IN REMOVAL OF INORGANIC AND ORGANIC WATER POLLUTANTS

    EPA Science Inventory

    Zeolites are well known for their ion exchange, adsorption and acid catalysis properties. Different inorganic and organic pollutants have been removed from water at room temperature using various zeolites. Synthetic zeolite Faujasite Y has been used to remove inorganic pollutants...

  20. Electrically Switched Cesium Ion Exchange

    SciTech Connect

    JPH Sukamto; ML Lilga; RK Orth

    1998-10-23

    This report discusses the results of work to develop Electrically Switched Ion Exchange (ESIX) for separations of ions from waste streams relevant to DOE site clean-up. ESIX combines ion exchange and electrochemistry to provide a selective, reversible method for radionuclide separation that lowers costs and minimizes secondary waste generation typically associated with conventional ion exchange. In the ESIX process, an electroactive ion exchange film is deposited onto. a high surface area electrode, and ion uptake and elution are controlled directly by modulating the potential of the film. As a result, the production of secondary waste is minimized, since the large volumes of solution associated with elution, wash, and regeneration cycles typical of standard ion exchange are not needed for the ESIX process. The document is presented in two parts: Part I, the Summary Report, discusses the objectives of the project, describes the ESIX concept and the approach taken, and summarizes the major results; Part II, the Technology Description, provides a technical description of the experimental procedures and in-depth discussions on modeling, case studies, and cost comparisons between ESIX and currently used technologies.

  1. Grafted methylenediphosphonate ion exchange resins

    DOEpatents

    Trochimcznk, A.W.; Gatrone, R.C.; Alexandratos, S.; Horwitz, E.P.

    1997-04-08

    An ion exchange resin is disclosed that is comprised of an insoluble copolymer onto which are grafted pendent groups that provide 1.0 to about 10 mmol/g dry weight phosphorus. The pendent groups have the formula as shown in the patent wherein R is hydrogen, a cation or mixtures thereof; and R{sup 1} is hydrogen or an C{sub 1}-C{sub 2} alkyl group. The resin also contains zero to about 5 mmol/g dry weight of pendent aromatic sulfonate groups. Processes for making and using an ion exchange resin are also disclosed.

  2. Grafted methylenediphosphonate ion exchange resins

    DOEpatents

    Trochimcznk, Andrzej W.; Gatrone, Ralph C.; Alexandratos, Spiro; Horwitz, E. Philip

    1997-01-01

    An ion exchange resin is disclosed that is comprised of an insoluble copolymer onto which are grafted pendent groups that provide 1.0 to about 10 mmol/g dry weight phosphorous. The pendent groups have the formula ##STR1## wherein R is hydrogen, a cation or mixtures thereof; and R.sup.1 is hydrogen or an C.sub.1 -C.sub.2 alkyl group. The resin also contains zero to about 5 mmol/g dry weight of pendent aromatic sulfonate groups. Processes for making and using an ion exchange resin are also disclosed.

  3. Grafted methylenediphosphonate ion exchange resins

    DOEpatents

    Trochimcznk, Andrzej W.; Gatrone, Ralph C.; Alexandratos, Spiro; Horwitz, E. Philip

    1998-01-27

    An ion exchange resin is disclosed that is comprised of an insoluble copolymer onto which are grafted pendent groups that provide 1.0 to about 10 mmol/g dry weight phosphorous. The pendent groups have the formula ##STR1## wherein R is hydrogen, a cation or mixtures thereof; and R.sup.1 is hydrogen or an C.sub.1 -C.sub.2 alkyl group. The resin also contains zero to about 5 mmol/g dry weight of pendent aromatic sulfonate groups. Processes for making and using an ion exchange-resin are also disclosed.

  4. A Colorful Ion Exchange Experiment

    NASA Astrophysics Data System (ADS)

    Mendes, Adélio

    1999-11-01

    A colorful ion-exchange experiment is described. The use of a resin with an adsorbed acid-base indicator allows students to follow the progress of the ion-exchange front along the column. In parallel, students can follow the ion-exchange breakthrough curve using a continuous conductometric cell at the column outlet. In the present example, K+ (KCl) exchanges with H+ (HCl) in a strong cationic resin (Amberlite IR 120). The adsorbed indicator is methyl violet. Sorption equilibrium is favorable to the K+ ions. Monovalent ions, used in this experiment, have the disadvantage of usually being colorless (except perhaps permanganate, but this is an extremely strong oxidant which attacks the resin). On the other hand, many divalent ions are colorful but the shape of the concentration front is hard to explain qualitatively as well as quantitatively. That is because the shape of the front depends on the total ionic concentration. However, color can be introduced in a monovalent ion-exchange system by adding an appropriate acid-base indicator to the resin. The text describes this experiment qualitatively. A simplified quantitative description, using the solute movement theory, can be found online.

  5. Phosphonic acid based ion exchange resins

    DOEpatents

    Horwitz, E.P.; Alexandratos, S.D.; Gatrone, R.C.; Chiarizia, R.

    1994-01-25

    An ion exchange resin is described for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene diphosphonic acid with styrene, acrylonitrile and divinylbenzene. 9 figures.

  6. Phosphonic acid based ion exchange resins

    DOEpatents

    Horwitz, E.P.; Alexandratos, S.D.; Gatrone, R.C.; Chiarizia, R.

    1996-07-23

    An ion exchange resin is described for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene diphosphonic acid with styrene, acrylonitrile and divinylbenzene. 10 figs.

  7. Phosphonic acid based ion exchange resins

    DOEpatents

    Horwitz, E. Philip; Alexandratos, Spiro D.; Gatrone, Ralph C.; Chiarizia, Ronato

    1996-01-01

    An ion exchange resin for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene diphosphonic acid with styrene, acrylonitrile and divinylbenzene.

  8. Phosphonic acid based ion exchange resins

    DOEpatents

    Horwitz, E. Philip; Alexandratos, Spiro D.; Gatrone, Ralph C.; Chiarizia, Ronato

    1994-01-01

    An ion exchange resin for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene disphosphonic acid with styrene, acrylonitrile and divinylbenzene.

  9. Pharmaceutical Applications of Ion-Exchange Resins

    ERIC Educational Resources Information Center

    Elder, David

    2005-01-01

    The historical uses of ion-exchanged resins and a summary of the basic chemical principles involved in the ion-exchanged process are discussed. Specific applications of ion-exchange are provided that include drug stabilization, pharmaceutical excipients, taste-masking agents, oral sustained-release products, topical products for local application…

  10. Radiation Studies with Argentine Ion Exchange Material

    SciTech Connect

    Crawford, C.L.

    2002-06-28

    A recent technology exchange between Argentina Nuclear Energy Commission (CNEA) and the US Department of Energy involved vitrification studies of ion exchange resins. Details of the spent ion exchange resins currently stored at two Argentine nuclear power plants, Atucha I and Embalse, have been presented in earlier reports. The present study examines irradiation of simulant samples of ion exchange resins.

  11. Electrically controlled cesium ion exchange

    SciTech Connect

    Lilga, M.

    1996-10-01

    Several sites within the DOE complex (Savannah River, Idaho, Oak Ridge and Hanford) have underground storage tanks containing high-level waste resulting from nuclear engineering activities. To facilitate final disposal of the tank waste, it is advantageous to separate and concentrate the radionuclides for final immobilization in a vitrified glass matrix. This task proposes a new approach for radionuclide separation by combining ion exchange (IX) and electrochemistry to provide a selective and economic separation method.

  12. PRTR ion exchange vault column sampling

    SciTech Connect

    Cornwell, B.C.

    1995-03-14

    This report documents ion exchange column sampling and Non Destructive Assay (NDA) results from activities in 1994, for the Plutonium Recycle Test Reactor (PRTR) ion exchange vault. The objective was to obtain sufficient information to prepare disposal documentation for the ion exchange columns found in the PRTR Ion exchange vault. This activity also allowed for the monitoring of the liquid level in the lower vault. The sampling activity contained five separate activities: (1) Sampling an ion exchange column and analyzing the ion exchange media for purpose of waste disposal; (2) Gamma and neutron NDA testing on ion exchange columns located in the upper vault; (3) Lower vault liquid level measurement; (4) Radiological survey of the upper vault; and (5) Secure the vault pending waste disposal.

  13. UTILITY OF ZEOLITES IN ARSENIC REMOVAL FROM WATER

    EPA Science Inventory

    Zeolites are well known for their ion exchange and adsorption properties. So far the cation exchanger properties of zeolites have been extensively studied and utilized. The anion exchanger properties of zeolites are less studied. Zeolite Faujasite Y has been used to remove arseni...

  14. Ion exchange purification of scandium

    DOEpatents

    Herchenroeder, Laurie A.; Burkholder, Harvey R.

    1990-10-23

    An improvement in purification of scandium through ion exchange chromatography is disclosed in which the oxidation potential of the eluting solution is altered by the addition of potassium chlorate or ammonium chloride so that removal of contaminants is encouraged. The temperature, pH and concentration of the eluent HEDTA are controlled in order to maintain the scandium in the column while minimizing dilution of the scandium band. Recovery of scandium is improved by pumping dilute scandium over the column prior to stripping the scandium and precipitation. This eliminates the HEDTA ion and other monovalent cations contaminating the scandium band. This method maximizes recovery of scandium while maintaining purity.

  15. Ion exchange purification of scandium

    DOEpatents

    Herchenroeder, L.A.; Burkholder, H.R.

    1990-10-23

    An improvement in purification of scandium through ion exchange chromatography is disclosed in which the oxidation potential of the eluting solution is altered by the addition of potassium chlorate or ammonium chloride so that removal of contaminants is encouraged. The temperature, pH and concentration of the eluent HEDTA are controlled in order to maintain the scandium in the column while minimizing dilution of the scandium band. Recovery of scandium is improved by pumping dilute scandium over the column prior to stripping the scandium and precipitation. This eliminates the HEDTA ion and other monovalent cations contaminating the scandium band. This method maximizes recovery of scandium while maintaining purity. 2 figs.

  16. Inorganic ion exchange evaluation and design: Silicotitanate ion exchange waste conversion

    SciTech Connect

    Balmer, M.L.; Bunker, B.C.

    1995-03-01

    Ion exchange materials are being evaluated for removing Cs, SR from tank waste. Thermal conversion of a variety of compositions within the Cs{sub 2}O-TiO{sub 2}-SiO{sub 2} phase diagram yielded both glass and crystalline materials, some of which show low leach rates and negligible Cs losses during heat treatment. A new material, CsTiSi{sub 2}0{sub 6}, with a structure isomorphous to pollucite (CsAlSi{sub 2}0{sub 6}) has been identified. This material represents a new class of crystalline zeolite materials which contain large amounts of titanium. Direct conversion of Cs loaded silicotitanate ion exchangers to CsTiSi{sub 2}O{sub 6} is an excellent alternative to dissolving the Cs-loaded or Cs-eluted exchangers in borosilicate glass because: CsTiSi{sub 2}O{sub 6} is formed using a simple, one step heat treatment. The unique crystalline pollucite-like structure of CsTiSi{sub 2}O{sub 6} traps Cs, and exhibits extremely low Cs leach rates. CsTiSi{sub 2}O{sub 6} is converted to solid waste at a low processing temperature of 700 to 800 C (nominal melter operating temperatures are 1150 C). CsTiSi{sub 2}0{sub 6} concentrates the waste, thus generating lower volumes of expensive HLW. Cs losses due to volatilization during processing of CsTiSi{sub 2}O{sub 6} are extremely low.

  17. Design and characterization of chitosan/zeolite composite films--Effect of zeolite type and zeolite dose on the film properties.

    PubMed

    Barbosa, Gustavo P; Debone, Henrique S; Severino, Patrícia; Souto, Eliana B; da Silva, Classius F

    2016-03-01

    Chitosan films can be used as wound dressings for the treatment of chronic wounds and severe burns. The antimicrobial properties of these films may be enhanced by the addition of silver. Despite the antimicrobial activity of silver, several studies have reported the cytotoxicity as a factor limiting its biomedical applications. This problem may, however, be circumvented by the provision of sustained release of silver. Silver zeolites can be used as drug delivery platforms to extend the release of silver. The objective of this study was to evaluate the addition of clinoptilolite and A-type zeolites in chitosan films. Sodium zeolites were initially subjected to ion-exchange in a batch reactor. Films were prepared by casting technique using a 2% w/w chitosan solution and two zeolite doses (0.1 or 0.2% w/w). Films were characterized by thermal analysis, color analysis, scanning electron microscopy, X-ray diffraction, and water vapor permeation. The results showed that films present potential for application as dressing. The water vapor permeability is one of the main properties in wound dressings, the best results were obtained for A-type zeolite/chitosan films, which presented a brief reduction of this property in relation to zeolite-free chitosan film. On the other hand, the films containing clinoptilolite showed lower water vapor permeation, which may be also explained by the best distribution of the particles into the polymer which also promoted greater thermal resistance. PMID:26706528

  18. Ion Exchange and Liquid Column Chromatography.

    ERIC Educational Resources Information Center

    Walton, Harold F.

    1980-01-01

    Emphasizes recent advances in principles and methodology in ion exchange and chromatography. Two tables list representative examples for inorganic ions and organic compounds. Cites 544 references. (CS)

  19. Pharmaceutical Applications of Ion-Exchange Resins

    NASA Astrophysics Data System (ADS)

    Elder, David P.

    2005-04-01

    The historical uses of ion-exchange resins and a summary of the basic chemical principles involved in the ion-exchange process are discussed. Specific applications of ion-exchange resins are provided. The utility of these agents to stabilize drugs are evaluated. Commonly occurring chemical and physical incompatibilities are reviewed. Ion-exchange resins have found applicability as inactive pharmaceutical constituents, particularly as disintegrants (inactive tablet ingredient whose function is to rapidly disrupt the tablet matrix on contact with gastric fluid). One of the more elegant approaches to improving palatability of ionizable drugs is the use of ion-exchange resins as taste-masking agents. The selection, optimization of drug:resin ratio and particle size, together with a review of scaleup of typical manufacturing processes for taste-masked products are provided. Ion-exchange resins have been extensively utilized in oral sustained-release products. The selection, optimization of drug:resin ratio and particle size, together with a summary of commonly occurring commercial sustained-release products are discussed. Ion-exchange resins have also been used in topical products for local application to the skin, including those where drug flux is controlled by a differential electrical current (ionotophoretic delivery). General applicability of ion-exchange resins, including ophthalmic delivery, nasal delivery, use as drugs in their own right (e.g., colestyramine, formerly referred to as cholestyramine), as well as measuring gastrointestinal transit times, are discussed. Finally, pharmaceutical monographs for ion-exchange resins are reviewed.

  20. Titania bound sodium titanate ion exchanger

    DOEpatents

    DeFilippi, Irene C. G.; Yates, Stephen Frederic; Shen, Jian-Kun; Gaita, Romulus; Sedath, Robert Henry; Seminara, Gary Joseph; Straszewski, Michael Peter; Anderson, David Joseph

    1999-03-23

    This invention is method for preparing a titania bound ion exchange composition comprising admixing crystalline sodium titanate and a hydrolyzable titanium compound and, thereafter drying the titania bound crystalline sodium titanate and subjecting the dried titania bound ion exchange composition to optional compaction and calcination steps to improve the physical strength of the titania bound composition.

  1. Ion Exchange and Adsorption of Inorganic Contaminants

    EPA Science Inventory

    In the first part of the chapter, the fundamentals of ion exchange and adsorption processes are explained, with the goal of demonstrating how these principles influence process design for inorganic contaminant removal. In the second part, ion exchange and adsorption processes th...

  2. Ion exchange in the nuclear industry

    SciTech Connect

    Bibler, J.P.

    1990-12-31

    Ion exchange is used in nearly every part of the nuclear fuel cycle -- from the purification of uranium from its ore to the final recovery of uranium and transmutation products. Ion exchange also plays a valuable role in the management of nuclear wastes generated in the fuel cycle.

  3. Ion exchange in the nuclear industry

    SciTech Connect

    Bibler, J.P.

    1990-01-01

    Ion exchange is used in nearly every part of the nuclear fuel cycle -- from the purification of uranium from its ore to the final recovery of uranium and transmutation products. Ion exchange also plays a valuable role in the management of nuclear wastes generated in the fuel cycle.

  4. Ion Exchange Formation via Sulfonated Bicomponent Nonwovens

    NASA Astrophysics Data System (ADS)

    Stoughton, Hannah L.

    For many years ion exchange resins were used to: remove heavy metals from water, recover materials from wastewater, and eliminate harmful gases from the air. While use of these resin beads dominates the ion exchange industry, the beads have limitations that should be considered when decisions are made to employ them. For instance, officials must balance the inherent zero sum surface area and porosity of the materials. This series of studies investigates the use of bicomponent nonwovens as a base substrate for producing high surface area ion exchange materials for the removal of heavy metal ions. Functionalized materials were produced in a two-step process: (1) PET/PE spunbond bicomponent fibers were fractured completely, producing the high surface area nonwoven to be used as the base ion exchange material, and (2) the conditions for functionalizing the PET fibers of the nonwoven webs were investigated where an epoxy containing monomer was grafted to the surface followed by sulfonation of the monomer. The functionalization reactions of the PET fibers were monitored based on: weight gain, FTIR, TOF-SIMS, and SEM. Ion exchange properties were evaluated using titration and copper ion removal capacity from test solutions. The relationship between web structure and removal efficiency of the metal ions was defined through a comparison of the bicomponent and homocomponent nonwovens for copper ion removal efficiency. The investigation revealed that utilizing the high surface area, fractured bicomponent nonwoven ion exchange materials with capacities comparable to commercially available ion exchange resins could be produced.

  5. Distribution of Components in Ion Exchange Materials Taken from the K East Basin and Leaching of Ion Exchange Materials by Nitric/Hydrofluoric Acid and Nitric/Oxalic Acid

    SciTech Connect

    Delegard, C.H.; Rinehart, D.E.; Hoopes, F.V.

    1999-04-02

    Laboratory tests were performed to examine the efficacy of mixed nitric/hydrofluoric acid followed by mixed nitric/oxalic acid leach treatments to decontaminate ion exchange materials that have been found in a number of samples retrieved from K East (KE)Basin sludge. The ion exchange materials contain organic ion exchange resins and zeolite inorganic ion exchange material. Based on process records, the ion exchange resins found in the K Basins is a mixed-bed, strong acid/strong base material marketed as Purolite NRW-037. The zeolite material is Zeolon-900, a granular material composed of the mineral mordenite. Radionuclides sorbed or associated with the ion exchange material can restrict its disposal to the Environmental Restoration Disposal Facility (ERDF). The need for testing to support development of a treatment process for K Basin sludge has been described in Section 4.2 of ''Testing Strategy to Support the Development of K Basins Sludge Treatment Process'' (Flament 1998). Elutriation and washing steps are designed to remove the organic resins from the K Basin sludge. To help understand the effects of the anticipated separation steps, tests were performed with well-rinsed ion exchange (IX) material from KE Basin floor sludge (sample H-08 BEAD G) and with well-rinsed IX having small quantities of added KE canister composite sludge (sample KECOMP). Tests also were performed to determine the relative quantities of organic and inorganic IX materials present in the H-08 K Basin sludge material. Based on chemical analyses of the separated fractions, the rinsed and dry IX material H-08 BEAD G was found to contain 36 weight percent inorganic material (primarily zeolite). The as-received (unrinsed) and dried H-08 material was estimated to contain 45 weight percent inorganic material.

  6. Porous Ceramic Spheres from Ion Exchange Resin

    NASA Technical Reports Server (NTRS)

    Dynys, Fred

    2005-01-01

    A commercial cation ion exchange resin, cross-linked polystyrene, has been successfully used as a template to fabricate 20 to 50 micron porous ceramic spheres. Ion exchange resins have dual template capabilities. Pore architecture of the ceramic spheres can be altered by changing the template pattern. Templating can be achieved by utilizing the internal porous structure or the external surface of the resin beads. Synthesis methods and chemical/physical characteristics of the ceramic spheres will be reported.

  7. 21 CFR 173.20 - Ion-exchange membranes.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ion-exchange membranes. 173.20 Section 173.20 Food... for Food Treatment § 173.20 Ion-exchange membranes. Ion-exchange membranes may be safely used in the processing of food under the following prescribed conditions: (a) The ion-exchange membrane is prepared...

  8. 21 CFR 173.20 - Ion-exchange membranes.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ion-exchange membranes. 173.20 Section 173.20 Food... Polymer Substances and Polymer Adjuvants for Food Treatment § 173.20 Ion-exchange membranes. Ion-exchange... ion-exchange membrane is prepared by subjecting a polyethylene base conforming to § 177.1520 of...

  9. 21 CFR 173.20 - Ion-exchange membranes.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ion-exchange membranes. 173.20 Section 173.20 Food... Polymer Substances and Polymer Adjuvants for Food Treatment § 173.20 Ion-exchange membranes. Ion-exchange... ion-exchange membrane is prepared by subjecting a polyethylene base conforming to § 177.1520 of...

  10. 21 CFR 173.20 - Ion-exchange membranes.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ion-exchange membranes. 173.20 Section 173.20 Food... Polymer Substances and Polymer Adjuvants for Food Treatment § 173.20 Ion-exchange membranes. Ion-exchange... ion-exchange membrane is prepared by subjecting a polyethylene base conforming to § 177.1520 of...

  11. 21 CFR 173.20 - Ion-exchange membranes.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ion-exchange membranes. 173.20 Section 173.20 Food... Polymer Substances and Polymer Adjuvants for Food Treatment § 173.20 Ion-exchange membranes. Ion-exchange... ion-exchange membrane is prepared by subjecting a polyethylene base conforming to § 177.1520 of...

  12. Solvent Extraction and Ion Exchange in Radiochemistry

    NASA Astrophysics Data System (ADS)

    Skarnemark, G.

    In 1805, Bucholz extracted uranium from a nitric acid solution into ether and back-extracted it into pure water. This is probably the first reported solvent-extraction investigation. During the following decades, the distribution of neutral compounds between aqueous phases and pure solvents was studied, e.g., by Peligot, Berthelot and Jungfleisch, and Nernst. Selective extractants for analytical purposes became available during the first decades of the twentieth century. From about 1940, extractants such as organophosphorous esters and amines were developed for use in the nuclear fuel cycle. This connection between radiochemistry and solvent-extraction chemistry made radiochemists heavily involved in the development of new solvent extraction processes, and eventually solvent extraction became a major separation technique in radiochemistry. About 160 years ago, Thompson and Way observed that soil can remove potassium and ammonium ions from an aqueous solution and release calcium ions. This is probably the first scientific report on an ion-exchange separation. The first synthesis of the type of organic ion exchangers that are used today was performed by Adams and Holmes in 1935. Since then, ion-exchange techniques have been used extensively for separations of various radionuclides in trace as well as macro amounts. During the last 4 decades, inorganic ion exchangers have also found a variety of applications. Today, solvent extraction as well as ion exchange are used extensively in the nuclear industry and for nuclear, chemical, and medical research. Some of these applications are discussed in the chapter.

  13. Modeling of Crystalline Silicotitanate Ion Exchange Columns

    SciTech Connect

    Walker, D.D.

    1999-03-09

    Non-elutable ion exchange is being considered as a potential replacement for the In-Tank Precipitation process for removing cesium from Savannah River Site (SRS) radioactive waste. Crystalline silicotitanate (CST) particles are the reference ion exchange medium for the process. A major factor in the construction cost of this process is the size of the ion exchange column required to meet product specifications for decontaminated waste. To validate SRS column sizing calculations, SRS subcontracted two reknowned experts in this field to perform similar calculations: Professor R. G. Anthony, Department of Chemical Engineering, Texas A&038;M University, and Professor S. W. Wang, Department of Chemical Engineering, Purdue University. The appendices of this document contain reports from the two subcontractors. Definition of the design problem came through several meetings and conference calls between the participants and SRS personnel over the past few months. This document summarizes the problem definition and results from the two reports.

  14. Organic ion exchange resin separation methods evaluation

    SciTech Connect

    Witwer, K.S.

    1998-05-27

    This document describes testing to find effective methods to separate Organic Ion Exchange Resin (OIER) from a sludge simulant. This task supports a comprehensive strategy for treatment and processing of K-Basin sludge. The simulant to be used resembles sludge that has accumulated in the 105KE and 105KW Basins in the 1OOK area of the Hanford Site. The sludge is an accumulation of fuel element corrosion products, organic and inorganic ion exchange materials, canister gasket materials, iron and aluminum corrosion products, sand, dirt, and other minor amounts of organic matter.

  15. Commercial Ion Exchange Resin Vitrification Studies

    SciTech Connect

    Cicero-Herman, C.A

    2002-06-28

    In the nuclear industry, ion exchange resins are used for purification of aqueous streams. The major contaminants of the resins are usually the radioactive materials that are removed from the aqueous streams. The use of the ion exchange resins creates a waste stream that can be very high in both organic and radioactive constituents. Therefore, disposal of the spent resin often becomes an economic problem because of the large volumes of resin produced and the relatively few technologies that are capable of economically stabilizing this waste. Vitrification of this waste stream presents a reasonable disposal alternative because of its inherent destruction capabilities, the volume reductions obtainable, and the durable product that it produces.

  16. ION EXCHANGE SOFTENING: EFFECTS ON METAL CONCENTRATIONS

    EPA Science Inventory

    A corrosion control pipe loop study to evaluate the effect of ion exchange water softening on metal leaching from household plumbing materials was conducted on two different water qualities having different pH's and hardness levels. The results showed that removing hardness ions ...

  17. Thermal Analysis of LANL Ion Exchange Column

    SciTech Connect

    Laurinat, J.E.

    1999-06-16

    This document reports results from an ion exchange column heat transfer analysis requested by Los Alamos National Laboratory (LANL). The object of the analysis is to demonstrate that the decay heat from the Pu-238 will not cause resin bed temperatures to increase to a level where the resin significantly degrades.

  18. Ion Exchange Membrane Influence on Ohmic Resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selection of the proper ion exchange membrane can have a significant influence on bioelectrochemical system (BES) power densities. Because ions move across the membrane to achieve electroneutrality, the ion transport resistance (ohmic loss) needs to be minimized to increase power densities. Ohmic ...

  19. Cesium Separation Using Electrically Switched Ion Exchange

    SciTech Connect

    Lilga, Michael A.); Orth, Rick J.); Sukamto, Johanes H.); Rassat, Scot D.); Genders, J D.; Gopal, R

    2001-09-01

    Electrically Switched Ion Exchange (ESIX) is a separation technology being developed at Pacific Northwest National Laboratory as an alternative to conventional ion exchange for removing metal ions from wastewater. In ESIX, which combines ion exchange and electro-chemistry, ion uptake and elution can be controlled directly by modulating the potential of an ion exchange film that has been electrochemically deposited onto an electrode. This paper presents the results of experiments on high surface area electrodes and the development of a flow system for cesium ion separation. Bench-scale flow system studies showed no change in capacity or performance of the ESIX films at a flow rate up to 113 BV/h, the maxi-mum flow rate tested, and breakthrough curves supported once-through waste processing. A comparison of results for a stacked 5-electrode cell versus a single-electrode cell showed enhanced breakthrough performance. In the stacked configuration, break-through began at about 120 BV for a feed containing 0.2 ppm cesium at a flow rate of 13 BV/h. A case study for the KE Basin (a spent nuclear fuel storage basin) on the Hanford Site demonstrated that KE Basin wastewater could be processed continuously with minimal waste generation, reduced disposal costs, and lower capital expenditures.

  20. Development and testing of ion exchangers for treatment of liquid wastes at Oak Ridge National Laboratory

    SciTech Connect

    Collins, J.L.; Davidson, D.J.; Chase, C.W.; Egan, B.Z. ); Ensor, D.D.; Bright, R.M.; Glasgow, D.C. )

    1993-03-01

    This report addresses three areas of waste treatment: (1) treatment of newly generated low-level liquid waste and Melton Valley Storage Tank (MVST) supernate using inorganic ion exchangers; (2) treatment of processing streams at the Radiochemical Engineering Development Center (REDC); and (3) removal of radionuclides from organic solutions. Distribution of various radionuclides between simulated waste solutions and several sorbents was determined in batch tests. Inorganic ion exchangers were prepared in the form of microspheres by an intemal gelation process. Microspheres of hydrous titania, hydrous zirconia, hydrous titania containing embedded sodium cobalt hexacyanoferrate, and the corresponding phosphate forms of these materials were prepared. Several zeolites (PDZ-140, PDZ-300, EE-96, CBV-10A) and inorganic ion exchangers (hydrous titania, hydrous zirconia, polyantimanic acid, sodium cobalt hexacyanoferrate) were tested for the removal of cesium and strontium from the acidic simulated Cleanex raffinate generated at REDC. A resorcinol-based ion-exchange resin and three types of sodium titanate were tested for removal of cesium and strontium from the REDC caustic dissolver solution. Hydrous titania, hydrous zirconia, and their corresponding phosphates were tested for the removal of Eu[sup 3+] from various solutions of di-2-ethylbexyl phosphoric acid (HDEHP) in toluene or dodecane.

  1. Development and testing of ion exchangers for treatment of liquid wastes at Oak Ridge National Laboratory

    SciTech Connect

    Collins, J.L.; Davidson, D.J.; Chase, C.W.; Egan, B.Z.; Ensor, D.D.; Bright, R.M.; Glasgow, D.C.

    1993-03-01

    This report addresses three areas of waste treatment: (1) treatment of newly generated low-level liquid waste and Melton Valley Storage Tank (MVST) supernate using inorganic ion exchangers; (2) treatment of processing streams at the Radiochemical Engineering Development Center (REDC); and (3) removal of radionuclides from organic solutions. Distribution of various radionuclides between simulated waste solutions and several sorbents was determined in batch tests. Inorganic ion exchangers were prepared in the form of microspheres by an intemal gelation process. Microspheres of hydrous titania, hydrous zirconia, hydrous titania containing embedded sodium cobalt hexacyanoferrate, and the corresponding phosphate forms of these materials were prepared. Several zeolites (PDZ-140, PDZ-300, EE-96, CBV-10A) and inorganic ion exchangers (hydrous titania, hydrous zirconia, polyantimanic acid, sodium cobalt hexacyanoferrate) were tested for the removal of cesium and strontium from the acidic simulated Cleanex raffinate generated at REDC. A resorcinol-based ion-exchange resin and three types of sodium titanate were tested for removal of cesium and strontium from the REDC caustic dissolver solution. Hydrous titania, hydrous zirconia, and their corresponding phosphates were tested for the removal of Eu{sup 3+} from various solutions of di-2-ethylbexyl phosphoric acid (HDEHP) in toluene or dodecane.

  2. Conceptual study of in-tank cesium removal using an inorganic ion exchange material

    SciTech Connect

    Goheen, R.S.; Kurath, D.E.

    1996-04-01

    Presently, the Hanford Site contains approximately 230,000 m{sup 3} of mixed waste stored in 177 underground tanks. Approximately 55,000 m{sup 3} of this waste is sludge, 90,000 m{sup 3} is salt cake, and 80,000 m{sup 3} is supernate. Although the pretreatment and final disposal requirements for the waste have not been entirely defined, it is likely that some supernatant pretreatment will be required to remove {sup 137}Cs and possibly {sup 90}Sr and the transuranic components. The objective of this study was to estimate the number of HLW glass canisters resulting from the use of inorganic ion exchanger materials as in-tank pretreatment technology. The variables in the study were: number of contacts between waste and ion exchange material; ion exchange material; and decontamination requirement. This conceptual study investigates a generic in-tank Cs removal flowsheet using crystalline silico-titanates and IE-96 zeolites, and the impact of each ion exchanger on the number of glass canisters produced. In determining glass formulation, data based on current reference technology was used. Sample calculations from the worksheets and summaries of final calculated results are included at the end of this report.

  3. An Empirical Formula From Ion Exchange Chromatography and Colorimetry.

    ERIC Educational Resources Information Center

    Johnson, Steven D.

    1996-01-01

    Presents a detailed procedure for finding an empirical formula from ion exchange chromatography and colorimetry. Introduces students to more varied techniques including volumetric manipulation, titration, ion-exchange, preparation of a calibration curve, and the use of colorimetry. (JRH)

  4. Modeling ion exchange in clinoptilolite using the EQ3/6 geochemical modeling code

    SciTech Connect

    Viani, B.E.; Bruton, C.J.

    1992-06-01

    Assessing the suitability of Yucca Mtn., NV as a potential repository for high-level nuclear waste requires the means to simulate ion-exchange behavior of zeolites. Vanselow and Gapon convention cation-exchange models have been added to geochemical modeling codes EQ3NR/EQ6, allowing exchange to be modeled for up to three exchangers or a single exchanger with three independent sites. Solid-solution models that are numerically equivalent to the ion-exchange models were derived and also implemented in the code. The Gapon model is inconsistent with experimental adsorption isotherms of trace components in clinoptilolite. A one-site Vanselow model can describe adsorption of Cs or Sr on clinoptilolite, but a two-site Vanselow exchange model is necessary to describe K contents of natural clinoptilolites.

  5. Porous solid ion exchange wafer for immobilizing biomolecules

    DOEpatents

    Arora, Michelle B.; Hestekin, Jamie A.; Lin, YuPo J.; St. Martin, Edward J.; Snyder, Seth W.

    2007-12-11

    A porous solid ion exchange wafer having a combination of a biomolecule capture-resin and an ion-exchange resin forming a charged capture resin within said wafer. Also disclosed is a porous solid ion exchange wafer having a combination of a biomolecule capture-resin and an ion-exchange resin forming a charged capture resin within said wafer containing a biomolecule with a tag. A separate bioreactor is also disclosed incorporating the wafer described above.

  6. 21 CFR 173.21 - Perfluorinated ion exchange membranes.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Perfluorinated ion exchange membranes. 173.21... ion exchange membranes. Substances identified in paragraph (a) of this section may be safely used as ion exchange membranes intended for use in the treatment of bulk quantities of liquid food under...

  7. 21 CFR 173.21 - Perfluorinated ion exchange membranes.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Perfluorinated ion exchange membranes. 173.21... ion exchange membranes. Substances identified in paragraph (a) of this section may be safely used as ion exchange membranes intended for use in the treatment of bulk quantities of liquid food under...

  8. 21 CFR 173.21 - Perfluorinated ion exchange membranes.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Perfluorinated ion exchange membranes. 173.21... ion exchange membranes. Substances identified in paragraph (a) of this section may be safely used as ion exchange membranes intended for use in the treatment of bulk quantities of liquid food under...

  9. 21 CFR 173.21 - Perfluorinated ion exchange membranes.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Perfluorinated ion exchange membranes. 173.21... ion exchange membranes. Substances identified in paragraph (a) of this section may be safely used as ion exchange membranes intended for use in the treatment of bulk quantities of liquid food under...

  10. 21 CFR 173.21 - Perfluorinated ion exchange membranes.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Perfluorinated ion exchange membranes. 173.21... Polymer Adjuvants for Food Treatment § 173.21 Perfluorinated ion exchange membranes. Substances identified in paragraph (a) of this section may be safely used as ion exchange membranes intended for use in...

  11. Properties of Zeolite A Obtained from Powdered Laundry Detergent: An Undergraduate Experiment.

    ERIC Educational Resources Information Center

    Smoot, Alison L.; Lindquist, David A.

    1997-01-01

    Presents experiments that introduce students to the myriad properties of zeolites using the sodium form of zeolite A (Na-A) from laundry detergent. Experiments include extracting Na-A from detergent, water softening properties, desiccant properties, ion-exchange properties, and Zeolite HA as a dehydration catalyst. (JRH)

  12. ZEOLITE PERFORMANCE AS AN ANION EXCHANGER FOR ARSENIC SEQUESTRATION IN WATER

    EPA Science Inventory

    Zeolites are well known for their use in ion exchange and acid catalysis reactions. The use of zeolites in anion or ligand exchange reactions is less studied. The NH4+ form of zeolite Y (NY6, Faujasite) has been tested in this work to evaluate its performance for arsenic removal...

  13. PRTR ion exchange vault water removal

    SciTech Connect

    Ham, J.E.

    1995-11-01

    This report documents the removal of radiologically contaminated water from the Plutonium Recycle Test Reactor (PRTR) ion exchange vault. Approximately 57,000 liters (15,000 gallons) of water had accumulated in the vault due to the absence of a rain cover. The water was removed and the vault inspected for signs of leakage. No evidence of leakage was found. The removal and disposal of the radiologically contaminated water decreased the risk of environmental contamination.

  14. Ion Exchange Temperature Testing with SRF Resin

    SciTech Connect

    Russell, Renee L.; Rinehart, Donald E.; Brown, Garrett N.; Peterson, Reid A.

    2012-03-01

    Ion exchange using the Spherical Resorcinol-Formaldehyde (SRF) resin has been selected by the U.S. Department of Energy’s Office of River Protection for use in the Pretreatment Facility of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) and for potential application in an at-tank deployment for removing 137Cs. Recent proposed changes to the WTP ion exchange process baseline indicate that higher temperatures (50°C) to alleviate post-filtration precipitation issues prior to reaching the ion exchange columns may be required. Therefore, it is important to understand the behavior of SRF resin performance under the conditions expected with the new equipment and process changes. This research examined the impact of elevated temperature on resin loading and resin degradation during extended solution flow using elevated temperature (45°, 50°, 55°, 60°, 65°, 75°C). Testing for extended times at elevated temperatures showed that the resin does degrade and loading capacity is reduced at and above 45°C. Above 60°C the resin appears to not load at all.

  15. SPEEDUP{trademark} ion exchange column model

    SciTech Connect

    Hang, T.

    2000-03-06

    A transient model to describe the process of loading a solute onto the granular fixed bed in an ion exchange (IX) column has been developed using the SpeedUp{trademark} software package. SpeedUp offers the advantage of smooth integration into other existing SpeedUp flowsheet models. The mathematical algorithm of a porous particle diffusion model was adopted to account for convection, axial dispersion, film mass transfer, and pore diffusion. The method of orthogonal collocation on finite elements was employed to solve the governing transport equations. The model allows the use of a non-linear Langmuir isotherm based on an effective binary ionic exchange process. The SpeedUp column model was tested by comparing to the analytical solutions of three transport problems from the ion exchange literature. In addition, a sample calculation of a train of three crystalline silicotitanate (CST) IX columns in series was made using both the SpeedUp model and Purdue University's VERSE-LC code. All test cases showed excellent agreement between the SpeedUp model results and the test data. The model can be readily used for SuperLig{trademark} ion exchange resins, once the experimental data are complete.

  16. Solidification of ion exchange resin wastes

    SciTech Connect

    Not Available

    1982-08-01

    Solidification media investigated included portland type I, portland type III and high alumina cements, a proprietary gypsum-based polymer modified cement, and a vinyl ester-styrene thermosetting plastic. Samples formulated with hydraulic cement were analyzed to investigate the effects of resin type, resin loading, waste-to-cement ratio, and water-to-cement ratio. The solidification of cation resin wastes with portland cement was characterized by excessive swelling and cracking of waste forms, both after curing and during immersion testing. Mixed bed resin waste formulations were limited by their cation component. Additives to improve the mechanical properties of portland cement-ion exchange resin waste forms were evaluated. High alumina cement formulations dislayed a resistance to deterioration of mechanical integrity during immersion testing, thus providing a significant advantage over portland cements for the solidification of resin wastes. Properties of cement-ion exchange resin waste forms were examined. An experiment was conducted to study the leachability of /sup 137/Cs, /sup 85/Sr, and /sup 60/Co from resins modified in portland type III and high alumina cements. The cumulative /sup 137/Cs fraction release was at least an order of magnitude greater than that of either /sup 85/Sr or /sup 60/Co. Release rates of /sup 137/Cs in high alumina cement were greater than those in portland III cement by a factor of two.Compressive strength and leach testing were conducted for resin wastes solidified with polymer-modified gypsum based cement. /sup 137/Cs, /sup 85/Sr, and /sup 60/Co fraction releases were about one, two and three orders of magnitude higher, respectively, than in equivalent portland type III cement formulations. As much as 28.6 wt % dry ion exchange resin was successfully solidified using vinyl ester-styrene compared with a maximum of 25 wt % in both portland and gypsum-based cement.

  17. Ion exchange polymers and method for making

    NASA Technical Reports Server (NTRS)

    Philipp, Warren H. (Inventor); Street, Kenneth W., Jr. (Inventor)

    1994-01-01

    An ion exchange polymer comprised of an alkali metal or alkaline earth metal salt of a poly(carboxylic acid) in a poly(vinyl acetal) matrix is described. The polymer is made by treating a mixture made of poly(vinyl alcohol) and poly(acrylic acid) with a suitable aldehyde and an acid catalyst to cause acetalization with some cross-linking. The material is then subjected to an alkaline aqueous solution of an alkali metal salt or an alkali earth metal salt. All of the film forming and cross-linking steps can be carried out simultaneously, if desired.

  18. ION EXCHANGE ADSORPTION PROCESS FOR PLUTONIUM SEPARATION

    DOEpatents

    Boyd, G.E.; Russell, E.R.; Taylor, M.D.

    1961-07-11

    Ion exchange processes for the separation of plutonium from fission products are described. In accordance with these processes an aqueous solution containing plutonium and fission products is contacted with a cation exchange resin under conditions favoring adsorption of plutonium and fission products on the resin. A portion of the fission product is then eluted with a solution containing 0.05 to 1% by weight of a carboxylic acid. Plutonium is next eluted with a solution containing 2 to 8 per cent by weight of the same carboxylic acid, and the remaining fission products on the resin are eluted with an aqueous solution containing over 10 per cent by weight of sodium bisulfate.

  19. Biodegradation of ion-exchange media

    SciTech Connect

    Bowerman, B.S.; Clinton, J.H.; Cowdery, S.R.

    1988-01-01

    The purpose of this study was to investigate further the potential for ion-exchange media (resin beads or powdered filter media) to support biological growth. A mixed microbial culture was grown from resin wastes obtained from the BNL HFBR by mixing the resin with a nutrient salt solution containing peptone and yeast extract. Bacterial and fungal growths appeared in the solution and on the resins after 7 to 10 days incubation at 337)degree)C. The mixed microbial cultures were used to inoculate several resin types, both irradiated and unirradiated. 12 refs., 5 tabs.

  20. Novel silica-based ion exchange resin

    SciTech Connect

    1997-11-01

    Eichrom`s highly successful Diphonixo resin resembles a conventional ion exchange resin in its use of sulfonic acid ligands on a styrene- divinylbenzene matrix. Diphonix resin exhibits rapid exchange kinetics that allow economical operation of ion exchange systems. Unlike conventional resins, Diphonix resin contains chelating ligands that are diphosphonic acid groups that recognize and remove the targeted metals and reject the more common elements such as sodium, calcium and magnesium. This latter property makes Diphonix ideal for many industrial scale applications, including those involving waste treatment. For treatment of low-level, transuranic (TRU) and high- level radioactive wastes, Diphonix`s polystyrene backbone hinders its application due to radiolytic stability of the carbon-hydrogen bonds and lack of compatibility with expected vitrification schemes. Polystyrene-based Diphonix is approximately 60% carbon- hydrogen. In response to an identified need within the Department of Energy for a resin with the positive attributes of Diphonix that also exhibits greater radiolytic stability and final waste form compatibility, Eichrom has successfully developed a new, silica-based resin version of Diphonix. Target application for this new resin is for use in environmental restoration and waste management situations involving the processing of low-level, transuranic and high-level radioactive wastes. The resin can also be used for processing liquid mixed waste (waste that contains low level radioactivity and hazardous constituents) including mixed wastes contaminated with organic compounds. Silica-based Diphonix is only 10% carbon-hydrogen, with the bulk of the matrix silica.

  1. Inorganic ion exchangers for nuclear waste remediation

    SciTech Connect

    Clearfield, A.; Bortun, A.; Bortun, L.; Behrens, E.

    1997-10-01

    The objective of this work is to provide a broad spectrum of inorganic ion exchangers that can be used for a range of applications and separations involving remediation of groundwater and tank wastes. The authors intend to scale-up the most promising exchangers, through partnership with AlliedSignal Inc., to provide samples for testing at various DOE sites. While much of the focus is on exchangers for removal of Cs{sup +} and Sr{sup 2+} from highly alkaline tank wastes, especially at Hanford, the authors have also synthesized exchangers for acid wastes, alkaline wastes, groundwater, and mercury, cobalt, and chromium removal. These exchangers are now available for use at DOE sites. Many of the ion exchangers described here are new, and others are improved versions of previously known exchangers. They are generally one of three types: (1) layered compounds, (2) framework or tunnel compounds, and (3) amorphous exchangers in which a gel exchanger is used to bind a fine powder into a bead for column use. Most of these exchangers can be regenerated and used again.

  2. Ion exchange properties of humus acids

    NASA Astrophysics Data System (ADS)

    Shoba, V. N.; Chudnenko, K. V.

    2014-08-01

    Ion exchange equilibriums in a complex of brown humic acids (HAs) and related fulvic acids (FAs) with cations (H+, K+, Na+, Ca2+, Mg2+, Zn2+, Mn2+, Cu2+, Fe3+, and Al3+) have been studied, and the activity coefficients of the acid monoionic forms have been determined. The composition of the stoichiometric cell in the system of black and brown HAs and related FAs in a leached chernozem of the Ob' region has been calculated with consideration for the earlier studies of the ion exchange properties of black HAs and related FAs. It has been shown that hydrogen, calcium, magnesium, aluminum, and iron are the major components in the exchange complex of humus acids in the leached chernozem with the other cations being of subordinate importance. In spite of some differences between the analytical and calculated compositions of the humus acids, the results of the calculations can be considered satisfactory. They indicate that calculations are feasible for such complex objects as soils, and their accuracy will improve with the expansion of the experimental studies. The physicochemical simulation of the transformation of the humus acid composition under different acid-base conditions shows that the contents of most cations decrease under alkalization, and hydroxides or carbonates become the most stable forms of these cations. Under the acidification of solutions, the binding of alkaline and alkaline-earth elements by humus acids decreases and the adsorption of iron and aluminum by humus acids increases.

  3. Liquid membrane coated ion-exchange column solids

    DOEpatents

    Barkey, Dale P.

    1989-01-01

    This invention relates to a method for improving the performance of liquid embrane separations by coating a liquid membrane onto solid ion-exchange resin beads in a fixed bed. Ion-exchange beads fabricated from an ion-exchange resin are swelled with water and are coated with a liquid membrane material that forms a film over the beads. The beads constitute a fixed bed ion-exchange column. Fluid being treated that contains the desired ion to be trapped by the ion-exchange particle is passed through the column. A carrier molecule, contained in the liquid membrane ion-exchange material, is selected for the desired ion in the fluid. The carrier molecule forms a complex with the desired ion, transporting it through the membrane and thus separating it from the other ions. The solution is fed continuously until breakthrough occurs at which time the ion is recovered, and the bed is regenerated.

  4. Liquid membrane coated ion-exchange column solids

    DOEpatents

    Barkey, Dale P.

    1988-01-01

    This invention relates to a method for improving the performance of liquid membrane separations by coating a liquid membrane onto solid ion-exchange resin beads in a fixed bed. Ion-exchange beads fabricated from an ion-exchange resin are swelled with water and are coated with a liquid membrane material that forms a film over the beads. The beads constitute a fixed bed ion-exchange column. Fluid being treated that contains the desired ion to be trapped by the ion-exchange particle is passed through the column. A carrier molecule, contained in the liquid membrane ion-exchange material, is selective for the desired ion in the fluid. The carrier molecule forms a complex with the desired ion, transporting it through the membrane and thus separating it from the other ions. The solution is fed continuously until breakthrough occurs at which time the ion is recovered, and the bed is regenerated.

  5. Antimicrobial Activity of Silver Ions Released from Zeolites Immobilized on Cellulose Nanofiber Mats.

    PubMed

    Rieger, Katrina A; Cho, Hong Je; Yeung, Hiu Fai; Fan, Wei; Schiffman, Jessica D

    2016-02-10

    In this study, we exploit the high silver ion exchange capability of Linde Type A (LTA) zeolites and present, for the first time, electrospun nanofiber mats decorated with in-house synthesized silver (Ag(+)) ion exchanged zeolites that function as molecular delivery vehicles. LTA-Large zeolites with a particle size of 6.0 μm were grown on the surface of the cellulose nanofiber mats, whereas LTA-Small zeolites (0.2 μm) and three-dimensionally ordered mesoporous-imprinted (LTA-Meso) zeolites (0.5 μm) were attached to the surface of the cellulose nanofiber mats postsynthesis. After the three zeolite/nanofiber mat assemblies were ion-exchanged with Ag(+) ions, their ion release profiles and ability to inactivate Escherichia coli (E. coli) K12 were evaluated as a function of time. LTA-Large zeolites immobilized on the nanofiber mats displayed more than an 11 times greater E. coli K12 inactivation than the Ag-LTA-Large zeolites that were not immobilized on the nanofiber mats. This study demonstrates that by decorating nanometer to micrometer scale Ag(+) ion-exchanged zeolites on the surface of high porosity, hydrophilic cellulose nanofiber mats, we can achieve a tunable release of Ag(+) ions that inactivate bacteria faster and are more practical to use in applications over powder zeolites. PMID:26788882

  6. 21 CFR 173.25 - Ion-exchange resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...,” February 4, 1998, which is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ion-exchange resins. 173.25 Section 173.25 Food and... Substances and Polymer Adjuvants for Food Treatment § 173.25 Ion-exchange resins. Ion-exchange resins may...

  7. 21 CFR 173.25 - Ion-exchange resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...,” February 4, 1998, which is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ion-exchange resins. 173.25 Section 173.25 Food... for Food Treatment § 173.25 Ion-exchange resins. Ion-exchange resins may be safely used in...

  8. Thermodynamics of ion exchange between clinoptilolite and aqueous solutions of Na{sup +}/K{sup +} and Na{sup +}/Ca{sup 2+}

    SciTech Connect

    Pabalan, R.T.

    1994-11-01

    Because of their ion-exchange, adsorption, and molecular sieve properties, zeolite minerals have generated worldwide interest for use in a broad range of applications such as nuclear and municipal waste water treatment, stack-gas cleanup, natural gas purification, petroleum production, and in agriculture and aquaculture. To provide a thermodynamic basis for understanding zeolite-water interactions in geologic systems, ion-exchange experiments were conducted at 25{degrees}C between clinoptilolite, which is the predominant zeolite mineral in altered pyroclastic and volcaniclastic rocks, and aqueous mixtures of Na{sup +}/K{sup +} and Na{sup +}/Ca{sup 2+}. Isotherm points were obtained by equilibrating Na-clinoptilolite, which was prepared from clinoptilolite-rich tuff from Death Valley Junction, California, USA, and Na{sup +}/K{sup +} and Na{sup +}/Ca{sup 2+} chloride solutions having different ionic concentration ratios, but constant total normalities of 0.5, 0.05, or 0.005 N. The experimental data were interpreted using a Margules thermodynamic formulation for zeolite solid solutions, coupled with the Pitzer model for aqueous activity coefficients. The isotherm data for 0.5 N Na{sup +}/K{sup +} and Na{sup +}/Ca{sup 2+} solutions were used to derive equilibrium constants and Gibbs free energies for the ion-exchange reactions, as well as parameters for the Margules model. Using the same parameters derived from the 0.5 N data, isotherms were calculated for the 0.05 and 0.005 N solutions. The predicted values agree very well with experimental data. The results of this study indicate that a Margules solid solution model for zeolites, coupled with an activity coefficient model for aqueous solutions (e.g., Pitzer model), can successfully describe and predict binary ion-exchange equilibria between aqueous solutions and the zeolite mineral clinoptilolite over a wide range of solution composition and concentration.

  9. Synthesis and testing of nanosized zeolite Y

    NASA Astrophysics Data System (ADS)

    Karami, Davood

    kept constant. The extent to which the nanosized zeolite Y was formed depended on the types and amount of the organic templates as well as the ageing duration. The activity testing of four FCC catalysts prepared by using CREY (Calcined Rare Earth ion-exchanged) zeolites with different particle sizes was carried out in a fluidized bench-scale batch riser simulator reactor. The starting zeolites NaY of different particle sizes were subjected to two cycles of ion exchange treatment. The particle size of the supported zeolites was varied between 150 and 1800 nm. The preparation of FCC catalysts was conducted by mixing the CREY zeolite with silica-alumina matrix and silica sol binder. Each catalyst contained 25% zeolite. The results of catalytic cracking demonstrated the significant effect of size reduction of the starting zeolite Y on catalytic performance of FCC catalyst. Keywords. Zeolite NaY, Faujasite, Nanosized particles, Nanozeolite, Nanotechnology, Synthesis, Crystallization, Seeding, Ageing, Precipitated silica, Sylopol silica, Fumed silica, Silica sol, Soluble silicates, Alumina, SAR or SiO2/Al2O3 Ratios, Sodium hydroxide, Sodium aluminate, Organic templates, TMAOH, Surfactant (CTAB), Ammonium Sulfate, BET surface area, BJH Pore Size Distribution, Zetasizer Particle Size Distribution, Powder XRD, 27Al Solid-State NMR, Catalytic Impregnation, CREY Zeolite, Silica-Alumina Matrix, Ion Exchange, FCC Catalyst, Catalytic cracking, Riser SimulatorRTM, Steaming, Zeolite HY, Utrastable Zeolite Y (USY)

  10. Scintillating 99Tc Selective Ion Exchange Resins

    SciTech Connect

    Mitchell Greenhalgh; Richard D. Tillotson

    2012-07-01

    Scintillating technetium (99Tc) selective ion exchange resins have been developed and evaluated for equilibrium capacities and detection efficiencies. These resins can be utilized for the in-situ concentration and detection of low levels of pertechnetate anions (99TcO4-) in natural waters. Three different polystyrene type resin support materials were impregnated with varying amounts of tricaprylmethylammonium chloride (Aliquat 336) extractant, several different scintillating fluors and wavelength shifters. The prepared resins were contacted batch-wise to equilibrium over a wide range of 99TcO4- concentrations in natural water. The measured capacities were used to develop Langmuir adsorption isotherms for each resin. 99Tc detection efficiencies were determined and up to 71.4 ± 2.6% was achieved with some resins. The results demonstrate that a low level detection limit for 99TcO4- in natural waters can be realized.

  11. Pyrolysis of Spent Ion Exchange Resins - 12210

    SciTech Connect

    Braehler, Georg; Slametschka, Rainer

    2012-07-01

    Organic ion exchangers (IEX) play a major and increasing role in the reactor coolant and other water purification processes. During their operation time they receive significant amounts of radioactivity, making their disposal, together with their organic nature, as medium active waste challenging. Processes applied so far do not eliminate the organic matter, which is unwanted in disposal facilities, or, if high temperatures are applied, raise problems with volatile radionuclides. NUKEM Technologies offers their well introduces process for the destruction of spent solvent (TBP), the pebble bed pyrolysis, now for the treatment of spent IEX (and other problematic waste), with the following benefits: the pyrolysis product is free of organic matter, and the operation temperature with approx. 500 deg. C keeps Cs radionuclides completely in the solid residue. (authors)

  12. TECHNICAL COMPARISON OF CANDIDATE ION EXCHANGE MEDIA FOR SMALL COLUMN ION EXCHANGE (SCIX) APPLICATIONS IN SUPPORT OF SUPPLEMENTAL LAW PRETREATMENT

    SciTech Connect

    RAMSEY AA; THORSON MR

    2010-12-28

    At-tank supplemental pretreatment including both filtration and small column ion exchange is currently under evaluation to facilitate salt waste retrieval and processing in the Hanford tank farms. Spherical resorcinol formaldehyde (sRF) resin is the baseline ion exchange resin for use in the Waste Treatment and Immobilization Plant (WTP). This document provides background and technical rationale to assist in determining whether spherical resorcinol formaldehyde (sRF) is also the appropriate ion exchange resin for supplemental LAW pretreatment processes and compares sRF with crystalline silicotitanate (CST) as potential supplemental pretreatment ion exchange media.

  13. Ion exchange materials, method of forming ion exchange materials, and methods of treating liquids

    DOEpatents

    Wertsching, Alan K.; Peterson, Eric S.; Wey, John E.

    2007-12-25

    The invention includes an ion affinity material having an organic component which is sulfonated and which is chemically bonded to an inorganic substrate component. The invention includes a method of forming a metal binding material. A solid support material comprising surface oxide groups is provided and an organic component having at least one alkyl halide is covalently linked to at least some of the surface oxide groups to form a modified support material. The at least one alkyl halide is subsequently converted into an alkyl sulfonate. The invention further includes a method and system for extracting ions from a liquid. An ion exchange material having a sulfonated alkyl silane component covalently bonded to a metal oxide support material is provided and a liquid is exposed to the ion exchange material.

  14. Rupture Loop Annex (RLA) ion exchange vault entry and characterization

    SciTech Connect

    Ham, J.E.

    1996-01-04

    This engineering report documents the entry and characterization of the Rupture Loop Annex Ion Exchange (RLAIX) Vault located near the 309 Building`s Plutonium Recycle Test Reactor (PRTR). Twelve ion exchange columns were found in the vault. Some of which contained transuranics, Cs 137, and Co 60. The characterization information is necessary for future vault cleanout and column disposal.

  15. Anisotropic microporous supports impregnated with polymeric ion-exchange materials

    DOEpatents

    Friesen, Dwayne; Babcock, Walter C.; Tuttle, Mark

    1985-05-07

    Novel ion-exchange media are disclosed, the media comprising polymeric anisotropic microporous supports containing polymeric ion-exchange or ion-complexing materials. The supports are anisotropic, having small exterior pores and larger interior pores, and are preferably in the form of beads, fibers and sheets.

  16. Ion Exchange Chromatography and Spectrophotometry: An Introductory Undergraduate Laboratory Experiment.

    ERIC Educational Resources Information Center

    Foster, N.; And Others

    1985-01-01

    Describes an experiment in which students use ion exchange chromatography to separate a mixture of chloro complexes of transition metal ions and then use spectrophotometry to define qualitatively the efficiency of the ion exchange columns. Background information, materials needed, and procedures used are included. (JN)

  17. Anisotropic microporous supports impregnated with polymeric ion-exchange materials

    DOEpatents

    Friesen, D.; Babcock, W.C.; Tuttle, M.

    1985-05-07

    Novel ion-exchange media are disclosed, the media comprising polymeric anisotropic microporous supports containing polymeric ion-exchange or ion-complexing materials. The supports are anisotropic, having small exterior pores and larger interior pores, and are preferably in the form of beads, fibers and sheets. 5 figs.

  18. Using Ion Exchange Chromatography to Separate and Quantify Complex Ions

    ERIC Educational Resources Information Center

    Johnson, Brian J.

    2014-01-01

    Ion exchange chromatography is an important technique in the separation of charged species, particularly in biological, inorganic, and environmental samples. In this experiment, students are supplied with a mixture of two substitution-inert complex ions. They separate the complexes by ion exchange chromatography using a "flash"…

  19. Radiation testing of organic ion exchange resins

    SciTech Connect

    Carlson, C.D.; Bray, L.A.; Bryan, S.A.

    1995-09-01

    A number of ion exchange materials are being evaluated as part of the Tank Waste Remediation System (TWRS) Pacific Northwest Laboratory (PNL) Pretreatment Project for the removal of {sup 137}Cs from aqueous tank wastes. Two of these materials are organic resins; a phenol-formaldehyde resin (Duolite CS-100) produced by Rohm and Haas Co. (Philadelphia, Pennsylvania) and a resorcinol-formaldehyde (RF) resin produced by Boulder Scientific Co. (Mead, Colorado). One of the key parameters in the assessment of the organic based ion exchange materials is its useful lifetime in the radioactive and chemical environment that will be encountered during waste processing. The focus of the work presented in this report is the radiation stability of the CS-100 and the RF resins. The scope of the testing included one test with a sample of the CS-100 resin and testing of two batches of the RF resin (BSC-187 and BSC-210). Samples of the exchangers were irradiated with a {sup 60}Co source to a total absorbed dose of 10{sup 9} R over a period of 5 months in a static (no flow) and a flowing configuration with neutralized current acid waste (NCAW) simulant as a feed. Based on a maximum concentration of {sup 137}Cs on the resin that would result from processing NCAW, this dose represents an operational period of at least 150 days for the RF resin and at least 1260 days for the CS-100 resin. Gas generation in the static experiment was continuously monitored and G values (molecules of gas per 100 eV) were determined for each species. Resin samples were obtained periodically and the equilibrium behavior of the resins was assessed by determining the distribution coefficients (K{sub d}s). Structural information was also obtained by {sup 13}C cross polarization magic angle (CPMAS) nuclear magnetic resonance (NMR) spectrometry and Fourier Transform Infrared (FTIR) spectroscopy so that changes to the chemical structure could be correlated with changes in K{sub d}.

  20. Waste treatment by selective mineral ion exchanger

    SciTech Connect

    Polito, Aurelie

    2007-07-01

    STMI, subsidiary company of the AREVA Group with over 40 years in the D and D business, has been continuously innovating and developing new decontamination techniques, with the objectives of achieving more efficient decontaminations on a growing spectrum of media. In the field of liquid waste treatment, STMI manufactures uses and commercialises selective inorganic ion exchangers (RAN). These are hydrated synthetic inorganic compounds prepared from very pure raw materials. Different types of RANs (POLYAN, OXTAIN, Fe-Cu, Fe-CoK, Si-Fe-CoK) can be used to trap a large number of radioactive elements in contaminated effluents. Different implementations could be applied depending on technical conditions. STMI's offers consist in building global solution and preliminary design of installation either in dispersed form (batch) or in column (cartridge filtration). Those products are used all over the world not only in the nuclear business (Canada, US, Belgium, France...) but also in other fields. Indeed, it provides competitive solutions to many domains of application especially water pollution control, liquid waste treatment in the nuclear business by decreasing the activity level of waste. The following paper will focus on the theoretical principle of the mineral exchanger, its implementation and the feed back collected by STMI. (author)

  1. Tc-99 Ion Exchange Resin Testing

    SciTech Connect

    Valenta, Michelle M.; Parker, Kent E.; Pierce, Eric M.

    2010-08-01

    Pacific Northwest National Laboratory was contracted by CHPRC to evaluate the release of 99Tc from spent resin used to treat water from well 299-W15-765 and stored for several years. The key questions to be answered are: 1) does 99Tc readily release from the spent ion exchange resin after being in storage for several years; 2) if hot water stripping is used to remove the co-contaminant carbon tetrachloride, will 99Tc that has been sequestered by the resin be released; and 3) can spent resin be encapsulated into a cementitious waste form; if so, how much 99Tc would be released from the weathering of the monolith waste form? The results from the long term stability leach test results confirm that the resin is not releasing a significant amount of the sequestered 99Tc, evident by the less than 0.02% of the total 99Tc loaded being identified in the solution. Furthermore, it is possible that the measured 99Tc concentration is the result of 99Tc contained in the pore spaces of the resin. In addition to these results, analyses conducted to examine the impact of hot water on the release of 99Tc suggest that only a small percentage of the total is being released. This suggest that hot water stripping to remove carbon tetrachloride will not have a significant affect on the resin’s ability to hold-on to sequestered 99Tc. Finally, encapsulation of spent resin in a cementitious material may be a viable disposal option, but additional tests are needed to examine the extent of physical degradation caused by moisture loss and the effect this degradation process can have on the release of 99Tc.

  2. Zeolite thin films: from computer chips to space stations.

    PubMed

    Lew, Christopher M; Cai, Rui; Yan, Yushan

    2010-02-16

    Zeolites are a class of crystalline oxides that have uniform and molecular-sized pores (3-12 A in diameter). Although natural zeolites were first discovered in 1756, significant commercial development did not begin until the 1950s when synthetic zeolites with high purity and controlled chemical composition became available. Since then, major commercial applications of zeolites have been limited to catalysis, adsorption, and ion exchange, all using zeolites in powder form. Although researchers have widely investigated zeolite thin films within the last 15 years, most of these studies were motivated by the potential application of these materials as separation membranes and membrane reactors. In the last decade, we have recognized and demonstrated that zeolite thin films can have new, diverse, and economically significant applications that others had not previously considered. In this Account, we highlight our work on the development of zeolite thin films as low-dielectric constant (low-k) insulators for future generation computer chips, environmentally benign corrosion-resistant coatings for aerospace alloys, and hydrophilic and microbiocidal coatings for gravity-independent water separation in space stations. Although these three applications might not seem directly related, they all rely on the ability to fine-tune important macroscopic properties of zeolites by changing their ratio of silicon to aluminum. For example, pure-silica zeolites (PSZs, Si/Al = infinity) are hydrophobic, acid stable, and have no ion exchange capacity, while low-silica zeolites (LSZs, Si/Al < 2) are hydrophilic, acid soluble, and have a high ion exchange capacity. These new thin films also take advantage of some unique properties of zeolites that have not been exploited before, such as a higher elastic modulus, hardness, and heat conductivity than those of amorphous porous silicas, and microbiocidal capabilities derived from their ion exchange capacities. Finally, we briefly discuss our

  3. FRACTIONATION OF COMPLEX MIXTURES USING AND ION-EXCHANGE METHODOLOGY

    EPA Science Inventory

    Fractionation of particle emission extracts captured from complex combustion mixtures gas performed upon environmental samples using an ion-exchange technique. aptured emissions from hazardous waste, municipal and medical/pathological incinerators along with urban air imputed by ...

  4. Hydrolyzed Poly(acrylonitrile) Electrospun Ion-Exchange Fibers

    PubMed Central

    Jassal, Manisha; Bhowmick, Sankha; Sengupta, Sukalyan; Patra, Prabir K.; Walker, Douglas I.

    2014-01-01

    Abstract A potential ion-exchange material was developed from poly(acrylonitrile) fibers that were prepared by electrospinning followed by alkaline hydrolysis (to convert the nitrile group to the carboxylate functional group). Characterization studies performed on this material using X-ray photoelectron spectroscopy, scanning electron microscopy, Fourier-Transform infra-red spectroscopy, and ion chromatography confirmed the presence of ion-exchange functional group (carboxylate). Optimum hydrolysis conditions resulted in an ion-exchange capacity of 2.39 meq/g. Ion-exchange fibers were used in a packed-bed column to selectively remove heavy-metal cation from the background of a benign, competing cation at a much higher concentration. The material can be efficiently regenerated and used for multiple cycles of exhaustion and regeneration. PMID:24963270

  5. Ion Exchange Separation of the Oxidation State of Vanadium.

    ERIC Educational Resources Information Center

    Cornelius, Richard

    1980-01-01

    Describes an experiment that emphasizes the discrete nature of the different oxidation states of vanadium by the separation of ammonium metavanadate into all four species by ion exchange chromatography. (CS)

  6. WASTEWATER DEMINERALIZATION BY CONTINUOUS COUNTER-CURRENT ION EXCHANGE PROCESS

    EPA Science Inventory

    A wastewater demineralization study employing a 38 lpm (10 gpm) continuous counter-current ion exchange pilot plant, manufactured by the Chemical Separations Corporation, Oak Ridge, Tennessee, has been conducted at the County Sanitation Districts, Pomona Research Facility, Pomona...

  7. Mineral Separation in a CELSS by Ion-exchange Chromatography

    NASA Technical Reports Server (NTRS)

    Ballou, E. V.; Spitze, L. A.; Wong, F. W.; Wydeven, T.; Johnson, C. C.

    1982-01-01

    Operational parameters pertinent to ion exchange chromatography separation were identified. The experiments were performed with 9 mm diameter ion exchange columns and conventional column accessories. The cation separation beds were packed with AG 50W-X2 strong acid cation exchange resin in H(+) form and 200-400 dry mesh particle size. The stripper beds used in some experiments were packed with AG 1-XB strong base cation exchange resin in OH(-) form and 200-400 dry mesh particle size.

  8. 21 CFR 173.25 - Ion-exchange resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...,” February 4, 1998, which is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ion-exchange resins. 173.25 Section 173.25 Food... Polymer Substances and Polymer Adjuvants for Food Treatment § 173.25 Ion-exchange resins....

  9. 21 CFR 173.25 - Ion-exchange resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...,” February 4, 1998, which is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ion-exchange resins. 173.25 Section 173.25 Food... Polymer Substances and Polymer Adjuvants for Food Treatment § 173.25 Ion-exchange resins....

  10. 21 CFR 173.25 - Ion-exchange resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...,” February 4, 1998, which is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ion-exchange resins. 173.25 Section 173.25 Food... Polymer Substances and Polymer Adjuvants for Food Treatment § 173.25 Ion-exchange resins....

  11. MODELING RESULTS FROM CESIUM ION EXCHANGE PROCESSING WITH SPHERICAL RESINS

    SciTech Connect

    Nash, C.; Hang, T.; Aleman, S.

    2011-01-03

    Ion exchange modeling was conducted at the Savannah River National Laboratory to compare the performance of two organic resins in support of Small Column Ion Exchange (SCIX). In-tank ion exchange (IX) columns are being considered for cesium removal at Hanford and the Savannah River Site (SRS). The spherical forms of resorcinol formaldehyde ion exchange resin (sRF) as well as a hypothetical spherical SuperLig{reg_sign} 644 (SL644) are evaluated for decontamination of dissolved saltcake wastes (supernates). Both SuperLig{reg_sign} and resorcinol formaldehyde resin beds can exhibit hydraulic problems in their granular (nonspherical) forms. SRS waste is generally lower in potassium and organic components than Hanford waste. Using VERSE-LC Version 7.8 along with the cesium Freundlich/Langmuir isotherms to simulate the waste decontamination in ion exchange columns, spherical SL644 was found to reduce column cycling by 50% for high-potassium supernates, but sRF performed equally well for the lowest-potassium feeds. Reduced cycling results in reduction of nitric acid (resin elution) and sodium addition (resin regeneration), therefore, significantly reducing life-cycle operational costs. These findings motivate the development of a spherical form of SL644. This work demonstrates the versatility of the ion exchange modeling to study the effects of resin characteristics on processing cycles, rates, and cold chemical consumption. The value of a resin with increased selectivity for cesium over potassium can be assessed for further development.

  12. Gadolinium-hydrogen ion exchange of zirconium phosphate

    NASA Technical Reports Server (NTRS)

    Liu, D. C.; Power, J. L.

    1972-01-01

    The Gd(+3)/H(+) ion exchange on a commercial zirconium phosphate ion exchanger was investigated in chloride, sulfate, and phosphate solutions of Gd(+3) at gadolinium concentrations of 0.001 to 1 millimole per cc and in the pH range of 0 to 3.5. Relatively low Gd(+3) capacities, in the range of 0.01 to 0.1 millimole per g of ion exchanger were found at room temperature. A significant difference in Gd(+3) sorption was observed, depending on whether the ion exchanger was converted from initial conditions of greater or lesser Gd(+3) sorption than the specific final conditions. Correlations were found between decrease in Gd(+3) capacity and loss of exchanger phosphate groups due to hydrolysis during washing and between increase in capacity and treatment with H3PO4. Fitting of the experimental data to ideal ion exchange equilibrium expressions indicated that each Gd(+3) ion is sorbed on only one site of the ion exchanger. The selectivity quotient was determined to be 2.5 + or - 0.4 at room temperature on gadolinium desorption in chloride solutions.

  13. Ion exchange defines the biological activity of titanate nanotubes.

    PubMed

    Rónavári, Andrea; Kovács, Dávid; Vágvölgyi, Csaba; Kónya, Zoltán; Kiricsi, Mónika; Pfeiffer, Ilona

    2016-05-01

    One-dimensional titanate nanotubes (TiONTs) were subjected to systematic ion exchange to determine the impact of these modifications on biological activities. Ion exchanged TiONTs (with Ag, Mg, Bi, Sb, Ca, K, Sr, Fe, and Cu ions) were successfully synthesized and the presence of the substituted ions was verified by energy dispersive X-ray spectroscopy (EDS). A complex screening was carried out to reveal differences in toxicity to human cells, as well as in antibacterial, antifungal, and antiviral activities between the various modified nanotubes. Our results demonstrated that Ag ion exchanged TiONTs exerted potent antibacterial and antifungal effects against all examined microbial species but were ineffective on viruses. Surprisingly, the antibacterial activity of Cu/TiONTs was restricted to Micrococcus luteus. Most ion exchanged TiONTs did not show antimicrobial activity against the tested bacterial and fungal species. Incorporation of various ions into nanotube architectures lead to mild, moderate, or even to a massive loss of human cell viability; therefore, this type of biological effect exerted by TiONTs can be greatly modulated by ion exchange. These findings further emphasize the contribution of ion exchange in determining not only the physical and chemical characteristics but also the bioactivity of TiONT against different types of living cells. PMID:26972521

  14. Modification of commercial NaY zeolite to give high water diffusivity and adsorb a large amount of water.

    PubMed

    Katoh, Masahiro; Kimura, Michisato; Sugino, Mao; Horikawa, Toshihide; Nakagawa, Keizo; Sugiyama, Shigeru

    2015-10-01

    By using NaY zeolites as desiccant materials, commercial NaY zeolite was alkali treated with 1 M NaOH aqueous solution and then Mg(2+) ion-exchanged by 0.5 M Mg(NO3)2 aqueous solution. Alkali treatment (AT) of NaY zeolite removed silicon atoms selectivity from the framework of Y-type zeolite and enhanced water diffusivity of Y-type zeolite. On the other hand, Mg(2+) ion-exchange of NaY zeolite increased the amount of water adsorbed. Prepared Y-AT-Mg zeolite had both water adsorption velocity and a large difference of water adsorbed amount between adsorption at 30 °C and desorption at 100 °C. PMID:26072446

  15. Concept of advanced spent fuel reprocessing based on ion exchange

    SciTech Connect

    Suzuki, Tatsuya; Takahashi, Kazuyuki; Nogami, Masanobu; Nomura, Masao; Fujii, Yasuhiko; Ozawa, Masaki |; Koyama, Shinichi; Mimura, Hitosi; Fujita, Reiko

    2007-07-01

    Reprocessing based on ion exchange separation is proposed as a safe, proliferation-resistant technology. Tertiary pyridine resin was developed for ion exchange reprocessing. Working medium of the separation system is not nitric acid but hydrochloric acid aqueous solution. The system does not involve strong oxidizing reagent, such as nitric acid but involve chloride ions which works as the week neutron absorbers. The system can be operated at ambient temperatures and pressure. Thus the HCl-ion-exchange reprocessing is regarded as an inherently safe technology. Another advantage of HCl ion-exchange reprocessing is the proliferation-resistant nature. Both U(VI) and Pu(IV) ions are adsorbed in the pyridine type anion exchange resin at relatively high HCl concentration of 6 M. At this condition, the adsorption distribution coefficient of Pu(IV) is smaller than that of U(VI). When uranium is eluted from the resin in the column, plutonium is simultaneously eluted from the column; Pu is recovered with uranium in the front part of uranium adsorption band. Pu(IV) can not be left in the resin after elution of uranium. The use of HCl in the ion-exchange reprocessing causes the problem of the plant materials. Sophisticated material technology is necessary to realize the ion exchange reprocessing using HCl. The technology is so sophisticated that only highly developed countries can hold the technology, thus the technology holding countries will be limited. The plant, therefore, cannot be built under hidden state. In addition, another merit of the process would be the simplicity in operation. One phase, i.e., ion exchange resin is immobile, and the aqueous solution is the only mobile phase. Plant operation is made by the control of one aqueous solution phase. The plant simplicity would ease the international safeguard inspection efforts to be applicable to this kind of reprocessing plant. The present work shows the basic concept of ion exchange reprocessing using HCl medium

  16. Interpenetrating polymer network ion exchange membranes and method for preparing same

    DOEpatents

    Alexandratos, Spiro D.; Danesi, Pier R.; Horwitz, E. Philip

    1989-01-01

    Interpenetrating polymer network ion exchange membranes include a microporous polymeric support film interpenetrated by an ion exchange polymer and are produced by absorbing and polymerizing monomers within the support film. The ion exchange polymer provides ion exchange ligands at the surface of and throughout the support film which have sufficient ligand mobility to extract and transport ions across the membrane.

  17. Development of a Waste Water Regenerative System - Using Sphagnum Moss Ion-exchange

    NASA Astrophysics Data System (ADS)

    McKeon, M.; Wheeler, R.; Leahy, Jj

    The use of inexpensive, light weight and regenerative systems in an enclosed environment is of great importance to sustained existence in such habitats as the International Space Station, Moon or even Mars. Many systems exist which utilise various synthetic ion exchangers to complete the process of waste water clean-up. These systems do have a very good exchange rate for cations but a very low exchange rate for anions. They also have a maximum capacity before they need regeneration. This research proposes a natural alternative to these synthetic ion-exchangers that utilises one of natures greatest ion-exchangers, that of Sphagnum Moss. Sphagna can be predominantly found in the nutrient poor environment of Raised Bogs, a type of isolated wetland with characteristic low pH and little interaction with the surrounding water table. All nutrients come from precipitation. The sphagna have developed as the bog's sponges, soaking up all available nutrients (both cation & anion) from the precipitation and eventually distributing them to the surrounding flora and fauna, through the water. The goal of this research is to use this ability in the processing of waste water from systems similar to isolated microgravity environments, to produce clean water for reuse in these environments. The nutrients taken up by the sphagna will also be utilised as a growth medium for cultivar growth, such as those selected for hydroponics' systems.

  18. Ion exchange properties of novel hydrous metal oxide materials

    SciTech Connect

    Gardner, T.J.; McLaughlin, L.I.

    1996-12-31

    Hydrous metal oxide (HMO) materials are inorganic ion exchangers which have many desirable characteristics for catalyst support applications, including high cation exchange capacity, anion exchange capability, high surface area, ease of adjustment of acidity and basicity, bulk or thin film preparation, and similar chemistry for preparation of various transition metal oxides. Cation exchange capacity is engineered into these materials through the uniform incorporation of alkali cations via manipulation of alkoxide chemistry. Specific examples of the effects of Na stoichiometry and the addition of SiO{sub 2} to hydrous titanium oxide (HTO) on ion exchange behavior will be given. Acid titration and cationic metal precursor complex exchange will be used to characterize the ion exchange behavior of these novel materials.

  19. ION EXCHANGE PERFORMANCE OF TITANOSILICATES, GERMANATES AND CARBON NANOTUBES

    SciTech Connect

    Alsobrook, A. N.; Hobbs, D. T.

    2013-04-24

    This report presents a summary of testing the affinity of titanosilicates (TSP), germanium-substituted titanosilicates (Ge-TSP) and multiwall carbon nanotubes (MWCNT) for lanthanide ions in dilute nitric acid solution. The K-TSP ion exchanger exhibited the highest affinity for lanthanides in dilute nitric acid solutions. The Ge-TSP ion exchanger shows promise as a material with high affinity, but additional tests are needed to confirm the preliminary results. The MWCNT exhibited much lower affinities than the K-TSP in dilute nitric acid solutions. However, the MWCNT are much more chemically stable to concentrated nitric acid solutions and, therefore, may candidates for ion exchange in more concentrated nitric acid solutions. This technical report serves as the deliverable documenting completion of the FY13 research milestone, M4FT-13SR0303061 – measure actinide and lanthanide distribution values in nitric acid solutions with sodium and potassium titanosilicate materials.

  20. Bend stresses arising from ion-exchange diffusion in glasses

    SciTech Connect

    Babukova, M.V.; Glebov, L.B.; Nikonorov, N.V.; Petrovskii, G.T.

    1985-11-01

    This paper demonstrates experimental confirmation of the presence of gigastresses arising under ion exchange, for the purpose of providing data relating to the magnitudes of stress greater than 1 GPa in these ion-exchange layers. To determine the stresses, a bend method was used on a specimen under nonuniform load. Small values of bend were determined on an IT-70 inferometer. With larger values of bend the radius of curvature of the surface was determined by measuring the focal distance in the beam of a He-Ne laser reflected from the specimen. Bending is observed in silicate glass subjected to unilateral ion-exchange diffusion of K/sup +/. It is shown that the bending of the specimens is caused by compressive stresses arising in the diffusion layer and having a value of greater than 1.5 GPa. The changes in the refractive index (RI) in the diffusion layer are determined primarily by the photoelastic effect.

  1. Evaluation of electrochemical ion exchange for cesium elution

    SciTech Connect

    Bontha, J.D.; Kurath, D.E.; Surma, J.E.; Buehler, M.F.

    1996-04-01

    Electrochemical elution was investigated as an alternative method to acid elution for the desorption of cesium from loaded ion exchange resins. The approach was found to have several potential advantages over existing technologies, in particular, electrochemical elution eliminates the need for addition of chemicals to elute cesium from the ion exchange resin. Also, since, in the electrochemical elution process the eluting solution is not in direct contact with the ion exchange material, very small volumes of the eluting solution can be used in a complete recycle mode in order to minimize the total volume of the cesium elute. In addition, the cesium is eluted as an alkaline solution that does not require neutralization with caustic to meet the tank farm specifications. Other advantages include easy incorporation of the electrochemical elution process into the present cesium recovery schemes.

  2. Silicon Removal from Waste Simulants via Ion Exchange

    SciTech Connect

    Wilmarth, W.R.

    2002-09-23

    examine a number of silica removal technologies to assist the processing of DWPF recycle water. Ion exchange is used commercially to remove soluble silicate ions and colloidal silica from various process waters. Three candidate ion exchange resins were selected after a literature search showed a potential applicability for DWPF Recycle. The results of these scouting tests showed the resins to be chemically stable in the alkaline environment of DWPF recycle. However, the resins were not effective at removing silicon. Additionally, results of silica analyses showed the silicon solubility in these feed solutions for ion exchange were still high after further acidification with respect to the goal of silicon removal. This suggests very strongly that pH adjustment (from 14 to 9), as a silicon removal technology is not viable.

  3. Ion-exchange properties of strontium hydroxyapatite under acidic conditions

    SciTech Connect

    Sugiyama, Shigeru; Nishioka, Hitoshi; Moriga, Toshihiro; Hayashi, Hiromu; Moffat, J.B.

    1998-09-01

    The ion exchange of strontium hydroxyapatite (SrHAp) with Pb{sup 2+} has been investigated under acidic conditions at 293 K. The addition of various acids to the exchanging solution enhanced the exchange capacity in the order HCl > HBr > HF > HNO{sub 3} > no acid, corresponding to the formation of halogen apatites with the former three acids or hydrogen phosphate with HNO{sub 3}. Since the ion-exchange capacity of SrHAp under nonacidic conditions is higher than that of chlorapatite, the aforementioned observations can be attributed to the participation of the protons introduced by the acids.z

  4. Rupture loop annex ion exchange RLAIX vault deactivation

    SciTech Connect

    Ham, J.E.; Harris, D.L., Westinghouse Hanford

    1996-08-01

    This engineering report documents the deactivation, stabilization and final conditions of the Rupture Loop Annex Ion Exchange (RLAIX) Vault located northwest of the 309 Building`s Plutonium Recycle Test Reactor (PRTR). Twelve ion exchange columns, piping debris, and column liquid were removed from the vault, packaged and shipped for disposal. The vault walls and floor were decontaminated, and portions of the vault were painted to fix loose contamination. Process piping and drains were plugged, and the cover blocks and rain cover were installed. Upon closure,the vault was empty, stabilized, isolated.

  5. EVALUATING ION EXCHANGE FOR REMOVING RADIUM FROM GROUNDWATER

    EPA Science Inventory

    This article, the second in a series, focuses on the results of bench- and pilot-scale studies of ion exchange processes for radium removal from groundwater in Lemont, Ill. Batch and column studies indicated a very high resin selectivity for radium compared with common cations. E...

  6. Pyrolysis of ion exchange resins for volume reduction and inertisation

    SciTech Connect

    Holst, L.; Hesboel, R.

    1995-12-31

    Radioactive ion exchange resins are produced in water cleaning systems in nuclear power plants. Studsvik RadWaste AB and GNS have developed a pyrolysis process for the treatment of resins with the goal of an optimal volume reduction and a transformation of the ion exchange resins into a biological and chemical inert state. The degradation products arising from the pyrolysis are char, tar and gas. In the pyrolysis process used by Studsvik RadWaste and GNS about 1/3 char, 1/3 water and tar and 1/3 gas are produced. The char is supercompacted in order to receive a volume reduction of about 10:1 and a better product for final storage. Ion exchange resins with a specific {beta}/{gamma} activity of 1E12 Bq/m{sup 3} with 50% of Co-60 can be handled. The retention of the activity has been 0.5E6:1. By processing a total of 100 kg ion exchange resins with a total activity of IE9 Bq only some hundred becquerel have been monitored outside the pyrolyzing unit. This means that the products leaving the pyrolyzing unit, in this case tar, water and gas could be handled as non radioactive material in a conventional waste treatment facility.

  7. DEVELOPMENT OF INORGANIC ION EXCHANGERS FOR NUCLEAR WASTE REMEDIATION

    EPA Science Inventory

    This research is concerned with the development of highly selective inorganic ion exchangers for the removal of primarily Cs+ and Sr2+ from nuclear tank waste and from groundwater. In this study, we will probe the, origins of selectivity through detailed structural studies and th...

  8. Method and solvent composition for regenerating an ion exchange resin

    DOEpatents

    Even, William R.; Irvin, David J.; Irvin, Jennifer A.; Tarver, Edward E.; Brown, Gilbert M.; Wang, James C. F.

    2002-01-01

    A method and composition for removing perchlorate from a highly selective ion exchange resin is disclosed. The disclosed approach comprises treating the resin in a solution of super critical or liquid carbon dioxide and one or more quaternary ammonium chloride surfactant compounds.

  9. Direct measurement of birefringence in ion-exchanged planar waveguides

    NASA Astrophysics Data System (ADS)

    Fazio, E.; Ramadan, W. A.; Bertolotti, M.; Righini, G. C.

    1996-08-01

    A direct measurement of the birefringence of a planar waveguide obtained by Na+ - K + ion exchange was performed with a double Lloyd interferometer. The results are compared with those obtained by a round-robin test involving the same sample. Birefringence of as much as Delta n=(2.0+/-0.2) \\times 10-3 was measured.

  10. Copper Removal from A-01 Outfall by Ion Exchange

    SciTech Connect

    Oji, L.N.

    1999-02-17

    Chelex100, a commercially available ion exchange resin, has been identified in this study as having a significant affinity for copper and zinc in the A-01 outfall water. Removal of copper and zinc from A-01 outfall water will ensure that the outfall meets the state of South Carolina's limit on these heavy metals.

  11. Cesium Ion Exchange Using Tank 241-AN-104 Supernate

    SciTech Connect

    Adu-Wusu, K.

    2003-12-22

    The River Protection Project is to design and build a high level nuclear waste treatment facility. The waste treatment plant is to process millions of gallons of radioactive waste stored in tanks at the Hanford Site. The high level nuclear waste treatment process includes various unit operations, such as ultrafiltration, precipitation, evaporation, ion exchange, and vitrification. Ion exchange is identified as the optimal treatment method for removal of cesium-137 and Tc-99 from the waste. Extensive ion exchange testing was performed using small-scale columns with actual waste samples. The objectives of this study were to: demonstrate SuperLig 644 ion exchange performance and process steps for the removal of cesium from actual AN-104 tank waste; pretreat actual AN-104 tank waste to reduce the concentration of cesium-137 in the waste below LAW vitrification limit; produce and characterize cesium eluate solutions for use in eluate evaporation tests. The experiments consisted of batch contact and small-scale column tests. The batch contact tests measured sorption partition coefficients Kds. The Kds were used to predict the effective resin capacity. The small-scale column tests, which closely mimic plant conditions, generated loading and elution profile data used to determine whether removal targets and design requirements were met.

  12. The many faces of ion-exchange resins

    SciTech Connect

    McNutty, J.T.

    1997-06-01

    Ion-exchange resins have been used commercially for over 60 years. Softening and demineralization of water for boiler feed and process use were then, and continue to be, the most familiar and widespread applications of ion-exchange resins throughout the chemical process industries (CPI). Several types of membrane-based technologies, such as electrodialysis, reverse osmosis and, more recently, electrodeionization are recognized as alternative methods for water treatment. Yet, modern versions of ion-exchange resins remain a major player in water treatment. In addition, these versatile materials can be found performing a wide range of tasks in both aqueous and nonaqueous environments. Some of these diverse applications include: acid or base catalysis; manufacture of high-purity solvents and reagent chemicals; separation of by-products of fermentation processes; deacidification of organic solvents; high-purity water production for semiconductor manufacture; recovery of valuable waste from dilute process effluents; controlled release of pharmaceutical products; and chromatography, both on the analytical and the industrial scale. The key to understanding the potential of ion-exchange resins is to look beyond their exchange and adsorptive characteristics, and to see their fundamental nature. In other words, it`s necessary to first consider them as spherical, particulate reactive polymers that perform chemical reactions.

  13. ELUTION OF URANIUM VALUES FROM ION EXCHANGE RESINS

    DOEpatents

    Kennedy, R.H.

    1959-11-24

    A process is described for eluting complex uranium ions absorbed on ion exchange resins. The resin is subjected to the action of an aqueous eluting solution contuining sulfuric acid and an alkali metal, ammonium, or magnesium chloride or nitrate, the elution being carried out until the desired amount of the uranium is removed from the resin.

  14. Desalination of brackish waters using ion-exchange media

    SciTech Connect

    Pless, J.D.; Philips, M.L.F.; Voigt, J.A.; Moore, D.; Axness, M.; Krumhansl, J.L.; Nenoff, T.M.

    2006-06-21

    An environmentally friendly method and materials study for desalinating inland brackish waters (i.e., coal bed methane produced waters) using a set of ion-exchange materials is presented. This desalination process effectively removes anions and cations in separate steps with minimal caustic waste generation. The anion-exchange material, hydrotalcite (HTC), exhibits an ion-exchange capacity (IEC) of around 3 mequiv g{sup -1}. The cation-exchange material, an amorphous aluminosilicate permutite-like material, (Na{sub x}+2yAl{sub x}Si{sub 1}-xO{sub 2+y}), has an IEC of around to 2.5 mequiv g{sup -1}. These ion-exchange materials were studied and optimized because of their specific ion-exchange capacity for the ions of interest and their ability to function in the temperature and pH regions necessary for cost and energy effectiveness. Room temperature, minimum pressure column studies (once-pass through) on simulant brackish water (total dissolved solids (TDS) = 2222 ppm) resulted in water containing TDS = 25 ppm. A second once-pass through column study on actual produced water (TDS = similar to 11 000) with a high carbonate concentration used an additional lime softening step and resulted in a decreased TDS of 600 ppm.

  15. Desalination of brackish waters using ion exchange media.

    SciTech Connect

    Pless, Jason D.; Krumhansl, James Lee; Nenoff, Tina Maria; Voigt, James A.; Phillips, Mark L. F.; Axness, Marlene; Moore, Diana Lynn

    2005-01-01

    An environmentally friendly method and materials study for desalinating inland brackish waters (i.e., coal bed methane produced waters) using a set of ion-exchange materials is presented. This desalination process effectively removes anions and cations in separate steps with minimal caustic waste generation. The anion-exchange material, hydrotalcite (HTC), exhibits an ion-exchange capacity (IEC) of {approx} 3 mequiv g{sup -1}. The cation-exchange material, an amorphous aluminosilicate permutite-like material, (Na{sub x+2y}Al{sub x}Si{sub 1-x}O{sub 2+y}), has an IEC of {approx}2.5 mequiv g{sup -1}. These ion-exchange materials were studied and optimized because of their specific ion-exchange capacity for the ions of interest and their ability to function in the temperature and pH regions necessary for cost and energy effectiveness. Room temperature, minimum pressure column studies (once-pass through) on simulant brackish water (total dissolved solids (TDS) = 2222 ppm) resulted in water containing TDS = 25 ppm. A second once-pass through column study on actual produced water (TDS = {approx}11,000) with a high carbonate concentration used an additional lime softening step and resulted in a decreased TDS of 600 ppm.

  16. Determination of boron in silicates after ion exchange separation

    USGS Publications Warehouse

    Kramer, H.

    1955-01-01

    Existing methods for the determination of boron in silicates are not entirely satisfactory. Separation as the methyl ester is lengthy and frequently erratic. An accurate and rapid method applicable to glass, mineral, ore, and water samples uses ion exchange to remove interfering cations, and boron is determined titrimetrically in the presence of mannitol, using a pH meter to indicate the end point.

  17. Thermal Analysis for Ion-Exchange Column System

    SciTech Connect

    Lee, Si Y.; King, William D.

    2012-12-20

    Models have been developed to simulate the thermal characteristics of crystalline silicotitanate ion exchange media fully loaded with radioactive cesium either in a column configuration or distributed within a waste storage tank. This work was conducted to support the design and operation of a waste treatment process focused on treating dissolved, high-sodium salt waste solutions for the removal of specific radionuclides. The ion exchange column will be installed inside a high level waste storage tank at the Savannah River Site. After cesium loading, the ion exchange media may be transferred to the waste tank floor for interim storage. Models were used to predict temperature profiles in these areas of the system where the cesium-loaded media is expected to lead to localized regions of elevated temperature due to radiolytic decay. Normal operating conditions and accident scenarios (including loss of solution flow, inadvertent drainage, and loss of active cooling) were evaluated for the ion exchange column using bounding conditions to establish the design safety basis. The modeling results demonstrate that the baseline design using one central and four outer cooling tubes provides a highly efficient cooling mechanism for reducing the maximum column temperature. In-tank modeling results revealed that an idealized hemispherical mound shape leads to the highest tank floor temperatures. In contrast, even large volumes of CST distributed in a flat layer with a cylindrical shape do not result in significant floor heating.

  18. ION-EXCHANGE PROCESSES AND MECHANISMS IN GLASSES

    EPA Science Inventory

    Recent performance assessment calculations of a disposal system at Hanford, Washington for low activity waste glass show that a Na ion-exchange reaction can effectively increase the radionuclide release rate by over a factor of 1000 and so is a major factor that currently limits ...

  19. EVALUATING ION EXCHANGE FOR REMOVING RADIUM FROM GROUNDWATER

    EPA Science Inventory

    This article focuses on the results of bench and pilot-scale studies of ion exchange processes for radium removal from groundwater in Lemont, Ill. atch and column studies indicated a very high resin selectivity for radium compared with common cations. xhaustion-regeneration studi...

  20. Waste separation and pretreatment using crystalline silicotitanate ion exchangers

    SciTech Connect

    Tadros, M.E.; Miller, J.E.; Anthony, R.G.

    1997-10-01

    A new class of inorganic ion exchangers called crystalline silicotitanates (CSTs) has been developed jointly by Sandia National Laboratories and Texas A&M University to selectively remove Cs and other radionuclides from a wide spectrum of radioactive defense wastes. The CST exhibits high selectivity and affinity for Cs and Sr under a wide range of conditions. Tests show it can remove part-per-million concentrations of Cs{sup +} from highly alkaline, high-sodium simulated radioactive waste solutions modeled after those at Hanford, Oak Ridge, and Savannah River. The materials exhibit ion exchange properties based on ionic size selectivity. Specifically, crystalline lattice spacing is controlled to be highly selective for Cs ions even in waste streams containing very high (5 to 10 M) concentrations of sodium. The CST technology is being demonstrated with actual waste at several DOE facilities. The use of inorganic ion exchangers. The inorganics are more resistant to chemical, thermal, and radiation degradation. Their high selectivities result in more efficient operations offering the possibility of a simple single-pass operation. In contrast, regenerable organic ion exchangers require additional processing equipment to handle the regeneration liquids and the eluant with the dissolved Cs.

  1. MINOR ACTINIDE SEPARATIONS USING ION EXCHANGERS OR IONIC LIQUIDS

    SciTech Connect

    Hobbs, D.; Visser, A.; Bridges, N.

    2011-09-20

    This project seeks to determine if (1) inorganic-based ion exchange materials or (2) electrochemical methods in ionic liquids can be exploited to provide effective Am and Cm separations. Specifically, we seek to understand the fundamental structural and chemical factors responsible for the selectivity of inorganic-based ion-exchange materials for actinide and lanthanide ions. Furthermore, we seek to determine whether ionic liquids can serve as the electrolyte that would enable formation of higher oxidation states of Am and other actinides. Experiments indicated that pH, presence of complexants and Am oxidation state exhibit significant influence on the uptake of actinides and lanthanides by layered sodium titanate and hybrid zirconium and tin phosphonate ion exchangers. The affinity of the ion exchangers increased with increasing pH. Greater selectivity among Ln(III) ions with sodium titanate materials occurs at a pH close to the isoelectric potential of the ion exchanger. The addition of DTPA decreased uptake of Am and Ln, whereas the addition of TPEN generally increases uptake of Am and Ln ions by sodium titanate. Testing confirmed two different methods for producing Am(IV) by oxidation of Am(III) in ionic liquids (ILs). Experimental results suggest that the unique coordination environment of ionic liquids inhibits the direct electrochemical oxidation of Am(III). The non-coordinating environment increases the oxidation potential to a higher value, while making it difficult to remove the inner coordination of water. Both confirmed cases of Am(IV) were from the in-situ formation of strong chemical oxidizers.

  2. Fly ash based zeolitic pigments for application in anticorrosive paints

    NASA Astrophysics Data System (ADS)

    Shaw, Ruchi; Tiwari, Sangeeta

    2016-04-01

    The purpose of this work is to evaluate the utilization of waste fly ash in anticorrosive paints. Zeolite NaY was synthesized from waste fly ash and subsequently modified by exchanging its nominal cation Na+ with Mg2+ and Ca2+ ions. The metal ion exchanged zeolite was then used as anticorrosive zeolitic pigments in paints. The prepared zeolite NaY was characterized using X-Ray diffraction technique and Scanning electron microscopy. The size, shape and density of the prepared fly ash based pigments were determined by various techniques. The paints were prepared by using fly ash based zeolitic pigments in epoxy resin and the percentages of pigments used in paints were 2% and 5%. These paints were applied to the mild steel panels and the anticorrosive properties of the pigments were assessed by the electrochemical spectroscopy technique (EIS).

  3. Demonstration of an Ion Exchange Resin Addition/Removal System with Superlig 659

    SciTech Connect

    Norato, M.A.

    2000-12-19

    A pilot facility was designed and built in the Thermal Fluids Laboratory at the Savannah River Technology Center to demonstrate the slurry transport of ion exchange resins in and out of ion exchange columns.

  4. Membrane consisting of polyquaternary amine ion exchange polymer network interpenetrating the chains of thermoplastic matrix polymer

    NASA Technical Reports Server (NTRS)

    Rembaum, A.; Wallace, C. J. (Inventor)

    1978-01-01

    An ion exchange membrane was formed from a solution containing dissolved matrix polymer and a set of monomers which are capable of reacting to form a polyquaternary ion exchange material; for example vinyl pyride and a dihalo hydrocarbon. After casting solution and evaporation of the volatile component's, a relatively strong ion exchange membrane was obtained which is capable of removing anions, such as nitrate or chromate from water. The ion exchange polymer forms an interpenetrating network with the chains of the matrix polymer.

  5. RECENT ADVANCES IN ION EXCHANGE MATERIALS AND PROCESSES FOR POLLUTION PREVENTION

    EPA Science Inventory

    The goal of this article was to summarize the recent advances in ion exchange technology for the metal finishing industry. Even though the ion exchange technology is mature and is widely employed in the industry, new applications, approaches and ion exchange materials are emergi...

  6. Sorption properties of radiation-cross-linked polymer hydrogels containing ion-exchange fibers

    NASA Astrophysics Data System (ADS)

    Rezvova, M. A.; Zhevnyk, V. D.; Pak, V.; Borodin, Y. V.; Kachina, E. V.

    2016-02-01

    Polymer hydrogel modification for soft contact lenses by ion-exchange fibers was studied in this work. The obtained results showed that the ion-exchange fiber modifiers have a number of advantages as compared with ion-exchange resin modifiers.

  7. Quantitative ion-exchange separation of plutonium from impurities

    SciTech Connect

    Pietri, C.E.; Freeman, B.P.; Weiss, J.R.

    1981-09-01

    The methods used at the New Brunswick Laboratory for the quantitative ion exchange separation of plutonium from impurities prior to plutonium assay are described. Other ion exchange separation procedures for impurity determination and for isotopic abundance measurements are given. The primary technique used consists of sorption of plutonium(IV) in 8N HNO/sub 3/ on Dowex-1 anion exchange resin and elution of the purified plutonium with 0.3N HCl-0.01N HF. Other methods consist of the anion exchange separation of plutonium(IV) in 12N HCl and the cation exchange separation of plutonium(III) in 0.2 N HNO/sub 3/. The application of these procedures to the subsequent assay of plutonium, isotopic analysis, and impurity determination is described.

  8. Solidification of ion exchange resin wastes in hydraulic cement

    SciTech Connect

    Neilson, R.M. Jr.; Kalb, P.; Fuhrmann, M.; Colombo, P.

    1982-01-01

    Work has been conducted to investigate the solidification of ion exchange resin wastes with portland cements. These efforts have been directed toward the development of acceptable formulations for the solidification of ion exchange resin wastes and the characterization of the resultant waste forms. This paper describes formulation development work and defines acceptable formulations in terms of ternary phase compositional diagrams. The effects of cement type, resin type, resin loading, waste/cement ratio and water/cement ratio are described. The leachability of unsolidified and solidified resin waste forms and its relationship to full-scale waste form behavior is discussed. Gamma irradiation was found to improve waste form integrity, apparently as a result of increased resin crosslinking. Modifications to improve waste form integrity are described. 3 tables.

  9. Ion exchange capacity of Nafion and Nafion composites

    SciTech Connect

    Chen, T.Y.; Leddy, J.

    2000-03-21

    The ion exchange capacity of recast Nafion films and composites of Nafion and polystyrene microbeads is determined by titration. Composite formation enhances exchange capacity; exchange capacity increases with the surface area microbeads in the composite. For recast films, an equivalent weight of 996 {+-} 24 is found, whereas the lowest equivalent weight (highest exchange capacity) found for composite is 878 {+-} 8. This suggests that {approx_gt} 13% of the exchange sites within recast films are inaccessible for ion exchange; for 1,100 equivalent weight material, {approx_gt} 25% of the sulfonates are inaccessible. Equivalent weight results are consistent with an ordered interfacial domain between Nafion and the microbeads. A fractal model based on microbead radii, microbead fraction, and interfacial domain thickness provides a predictive model for designing composites with increased exchange capacity and cation transport.

  10. Separation of americium from curium by oxidation and ion exchange.

    PubMed

    Burns, Jonathan D; Shehee, Thomas C; Clearfield, Abraham; Hobbs, David T

    2012-08-21

    Nuclear energy has the potential to be a clean alternative to fossil fuels, but in order for it to play a major role in the US, many questions about the back end of the fuel cycle must be addressed. One of these questions is the difficult separation of americium from curium. Here, we report the oxidation of Am in two systems, perchloric acid and nitric acid and the affect of changing the acid has on the oxidation. K(d) values were observed and a direct separation factor was calculated and was seen to be as high as 20 for four metal(IV) pillared phosphate phosphonate inorganic organic hybrid ion exchange materials. These ion exchangers are characterized by very low selectivity for cations with low charge but extremely high uptake of ions of high charge. PMID:22827724

  11. Design software for ion-exchanged glass waveguide devices

    NASA Astrophysics Data System (ADS)

    Tervonen, Ari; Honkanen, Seppo; Poyhonen, Pekka; Tahkokorpi, Markku T.

    1993-04-01

    Software tools for design of passive integrated optical components based on ion-exchanged glass waveguides have been developed. All design programs have been implemented on personal computers. A general simulation program for ion exchange processes is used for optimization of waveguide fabrication. The optical propagation in the calculated channel waveguide profiles is modelled with various methods. A user-friendly user's interface has been included in this modelling software. On the basis of the calculated propagation properties, performance of channel waveguide circuits can be modelled and thus devices for different applications may be designed. From the design parameters, the lithography mask pattern to be used is generated for a commercial CAD program for final mask design. Examples of designed and manufactured guided-wave devices are described. These include 1- to-n splitters and asymmetric Mach-Zehnder interferometers for wavelength division multiplexing.

  12. Development and evaluation of ion exchange hollow fibers. [vinyl copolymers

    NASA Technical Reports Server (NTRS)

    Smith, J. K.

    1975-01-01

    An ion exchange hollow fiber impregnated with a vinylpyridine base was developed. The basic exchange resin used to impart the necessary permselectivity to the hollow fiber is a copolymer of vinylpyridine and dibromoethane prepared according to Rembaum. A slight pressure was used to impregnate the exchange monomer mixture into the void structure of the fiber wall, and with maintenance of subambient temperatures, the rate of cross-linking is slow enough to allow the growing polymer to permeate the wall structure before significant increase in polymer molecular weight. These ion exchange fibers are produced from polyacrylonitrile hollow fibers with an appropriate wall structure that enables the impregnating vinylpyridine monomer mixture to form a truly semipermeable anion barrier after curing.

  13. Diffusion kinetics of the ion exchange of benzocaine on sulfocationites

    NASA Astrophysics Data System (ADS)

    Al'tshuler, O. G.; Shkurenko, G. Yu.; Gorlov, A. A.; Al'tshuler, G. N.

    2016-06-01

    The theory of the ion exchange kinetics on strong acid cationites with the participation of weak electrolytes is discussed. The kinetics of desorption of benzocaine in the protonated and molecular forms from strong acid cationites, sulfonated polycalixarene, and KU-23 30/100 sulfocationite, is studied experimentally. It is shown that the flow of protonated benzocaine from cationite upon desorption proceeding by the ion-exchange mechanism is more intense than upon desorption of nonionized benzocaine molecules. It is established that the diffusion coefficient of benzocaine cations is (1.21 ± 0.23) × 10-12 m2/s in KU-23 30/100 sulfocation and (0.65 ± 0.06) × 10-13 m2/s in sulfonated polycalixarene, while the diffusion coefficient of benzocaine molecules is (0.65 ± 0.15) × 10-14 m2/s in sulfonated polycalixarene.

  14. Effects of ionizing radiation on modern ion exchange materials

    SciTech Connect

    Marsh, S.F.; Pillay, K.K.S.

    1993-10-01

    We review published studies of the effects of ionizing radiation on ion exchange materials, emphasizing those published in recent years. A brief overview is followed by a more detailed examination of recent developments. Our review includes styrene/divinylbenzene copolymers with cation-exchange or anion-exchange functional groups, polyvinylpyridine anion exchangers, chelating resins, multifunctional resins, and inorganic exchangers. In general, strong-acid cation exchange resins are more resistant to radiation than are strong-base anion exchange resins, and polyvinylpyridine resins are more resistant than polystyrene resins. Cross-linkage, salt form, moisture content, and the surrounding medium all affect the radiation stability of a specific exchanger. Inorganic exchangers usually, but not always, exhibit high radiation resistance. Liquid ion exchangers, which have been used so extensively in nuclear processing applications, also are included.

  15. Electrical and magnetic properties of ion-exchangeable layered ruthenates

    SciTech Connect

    Sugimoto, Wataru . E-mail: wsugi@shinshu-u.ac.jp; Omoto, Masashi; Yokoshima, Katsunori; Murakami, Yasushi; Takasu, Yoshio

    2004-12-01

    An ion-exchangeable ruthenate with a layered structure, K{sub 0.2}RuO{sub 2.1}, was prepared by solid-state reactions. The interlayer cation was exchanged with H{sup +}, C{sub 2}H{sub 5}NH{sub 3}{sup +}, and ((C{sub 4}H{sub 9}){sub 4}N{sup +}) through proton-exchange, ion-exchange, and guest-exchange reactions. The electrical and magnetic properties of the products were characterized by DC resistivity and susceptibility measurements. Layered K{sub 0.2}RuO{sub 2.1} exhibited metallic conduction between 300 and 13K. The products exhibited similar magnetic behavior despite the differences in the type of interlayer cation, suggesting that the ruthenate sheet in the protonated form and the intercalation compounds possesses metallic nature.

  16. Radiation degradation in EPICOR-2 ion exchange resins

    SciTech Connect

    McConnell, J.W. Jr.; Johnson, D.A.; Sanders, R.D. Sr.

    1990-09-01

    The Low-Level Waste Data base Development -- EPICOR-II Resin/Liner Investigation Program funded by the US Nuclear Regulatory Commission is investigating chemical and physical conditions for organic ion exchange resins contained in several EPICOR-II prefilters. Those prefilters were used during cleanup of contaminated water from the Three Mile Island Nuclear Power Station after the March 1979 accident. The work was performed by EG G Idaho, Inc. at the Idaho Engineering Laboratory. This is the final report of this task and summarizes results and analyses of three samplings of ion exchange resins from prefilters PF-8 and -20. Results are compared with baseline data from tests performed on unirradiated resins supplied by Epicor, Inc. to determine the extent of degradation due to the high internal radiation dose received by the organic resins. Results also are compared with those of other researchers. 18 refs., 23 figs., 7 tabs.

  17. Hybrid metallic ion-exchanged waveguides for SPR biological sensing

    NASA Astrophysics Data System (ADS)

    de Bonnault, S.; Bucci, D.; Zermatten, P.. J.; Charette, P. G.; Broquin, J. E.

    2015-02-01

    Glass substrates have been used for decades to create biosensors due to their biocompatibility, low thermal conductivity, and limited fluorescence. Among the different types of sensors, those based on surface plasmon resonance (SPR) allow exploitation of the sensing lightwave at the vicinity of the sensor surface where small entities such as DNA or proteins are located. In this paper, ion-exchanged waveguides and SPR are combined to create a multianalyte optical sensor integrated onto glass. First the principle of operation is introduced, then the theoretical analysis and design of the sensing element. Simulations have been carried out using the Aperiodic Fourier Modal Method (AFMM) and a custom software that handles ion-exchange index-profiles. Fabrication and characterization processes are also presented. Finally the first experimental spectra are displayed and discussed. The sensor presents a bulk sensibility of 5000nm/RIU.

  18. Graphene/Ionic Liquid Composite Films and Ion Exchange

    PubMed Central

    Mo, Yufei; Wan, Yunfang; Chau, Alicia; Huang, Fuchuan

    2014-01-01

    Wettability of graphene is adjusted by the formation of various ionic surfaces combining ionic liquid (IL) self-assembly with ion exchange. The functionalized ILs were designed and synthesized with the goal of obtaining adjustable wettability. The wettability of the graphene surface bearing various anions was measured systematically. The effect of solvent systems on ion exchange ratios on the graphene surface has also been investigated. Meanwhile, the mechanical properties of the graphene/IL composite films were investigated on a nanometer scale. The elasticity and adhesion behavior of the thin film was determined with respected to the indentation deformation by colloid probe nanoindentation method. The results indicate that anions played an important role in determining graphene/IL composite film properties. In addition, surface wetting and mechanics can be quantitatively determined according to the counter-anions on the surface. This study might suggest an alternate way for quantity detection of surface ions by surface force. PMID:24970602

  19. Graphene/Ionic liquid composite films and ion exchange.

    PubMed

    Mo, Yufei; Wan, Yunfang; Chau, Alicia; Huang, Fuchuan

    2014-01-01

    Wettability of graphene is adjusted by the formation of various ionic surfaces combining ionic liquid (IL) self-assembly with ion exchange. The functionalized ILs were designed and synthesized with the goal of obtaining adjustable wettability. The wettability of the graphene surface bearing various anions was measured systematically. The effect of solvent systems on ion exchange ratios on the graphene surface has also been investigated. Meanwhile, the mechanical properties of the graphene/IL composite films were investigated on a nanometer scale. The elasticity and adhesion behavior of the thin film was determined with respected to the indentation deformation by colloid probe nanoindentation method. The results indicate that anions played an important role in determining graphene/IL composite film properties. In addition, surface wetting and mechanics can be quantitatively determined according to the counter-anions on the surface. This study might suggest an alternate way for quantity detection of surface ions by surface force. PMID:24970602

  20. Graphene/Ionic Liquid Composite Films and Ion Exchange

    NASA Astrophysics Data System (ADS)

    Mo, Yufei; Wan, Yunfang; Chau, Alicia; Huang, Fuchuan

    2014-06-01

    Wettability of graphene is adjusted by the formation of various ionic surfaces combining ionic liquid (IL) self-assembly with ion exchange. The functionalized ILs were designed and synthesized with the goal of obtaining adjustable wettability. The wettability of the graphene surface bearing various anions was measured systematically. The effect of solvent systems on ion exchange ratios on the graphene surface has also been investigated. Meanwhile, the mechanical properties of the graphene/IL composite films were investigated on a nanometer scale. The elasticity and adhesion behavior of the thin film was determined with respected to the indentation deformation by colloid probe nanoindentation method. The results indicate that anions played an important role in determining graphene/IL composite film properties. In addition, surface wetting and mechanics can be quantitatively determined according to the counter-anions on the surface. This study might suggest an alternate way for quantity detection of surface ions by surface force.

  1. Insoluble polyelectrolyte and ion-exchange hollow fiber impregnated therewith

    NASA Technical Reports Server (NTRS)

    Rembaum, A. (Inventor)

    1977-01-01

    The number of quaternary sites and ion exchange capacity of a polyquaternary, cross linked, insoluble copolymer of a vinyl pyridine and a dihalo organic compound is increased by about 15-35% by reaction of the polymer with an amine followed by quaternization, if required. The polymer forms spontaneously in the presence of a substrate such as within the pores of a hollow fiber. The improved resin impregnated fiber may be utilized to remove ions from waste or process steams.

  2. Cyanide recycling using strong-base ion-exchange resins

    NASA Astrophysics Data System (ADS)

    Leão, Versiane Albis; Ciminelli, Virgínia S. T.; Costa, Renato De Souza

    1998-10-01

    Among the techniques available to recover cyanide and metal cyanocomplexes from diluted streams, ion-exchange resins seem attractive because of the possibility of treating either pulps or clear solutions with this process. This article discusses the results of adsorption and elution of metal cyanocomplexes obtained with industrial effluents and selected data from the literature. The behavior of iron and copper cyanocomplexes during elution is emphasized.

  3. Separation of organic ion exchange resins from sludge -- engineering study

    SciTech Connect

    Duncan, J.B.

    1998-08-25

    This engineering study evaluates the use of physical separation technologies to separate organic ion exchange resin from KE Basin sludge prior to nitric acid dissolution. This separation is necessitate to prevent nitration of the organics in the acid dissolver. The technologies under consideration are: screening, sedimentation, elutriation. The recommended approach is to first screen the Sludge and resin 300 microns then subject the 300 microns plus material to elutriation.

  4. Thermal analysis for ion-exchange column system

    SciTech Connect

    Lee, S. Y.; King, W. D.

    2012-07-01

    Models have been developed to simulate the thermal characteristics of Crystalline Silico-titanate (CST) ion exchange media fully loaded with radioactive cesium in a column configuration and distributed within a waste storage tank. This work was conducted to support the Small Column Ion Exchange (SCIX) program which is focused on processing dissolved, high-sodium salt waste for the removal of specific radionuclides (including Cs-137, Sr-90, and actinides) within a High Level Waste (HLW) storage tank at the Savannah River Site. A two-dimensional computational modeling approach for the in-column ion-exchange domain was taken to include conservative, bounding estimates for key parameters such that the results would provide the maximum centerline temperatures achievable under the design configurations using a feed composition known to promote high cesium loading on CST. A primary objective of these calculations was to estimate temperature distributions across packed CST beds immersed in waste supernate or filled with dry air under various accident scenarios. Accident scenarios evaluated included loss of salt solution flow through the bed, inadvertent column drainage, and loss of active cooling in the column. The modeling results demonstrate that the baseline design using one central and four outer cooling tubes provides a highly efficient cooling mechanism for reducing the maximum column temperature. (authors)

  5. Properties of a Novel Ion-Exchange Film

    NASA Technical Reports Server (NTRS)

    Street, Kenneth W.; Hill, Carol M.; Philipp, Warren H.; Tanner, Stephen P.; Gorse, Joseph; Lusk, Amy; Taylor, Jason; Dickens, Jason

    2002-01-01

    A new ion-exchange material (based on polyacrylic acid) and some of its analytical applications have been reported. This paper contains data on the ion-exchange properties of the film form of the material and its potential application to the decontamination of waste water and drinking water. The film has a high exchange capacity of 5 to 6 meq/g and a pK(sub a) of 5.7. The calcium form is the most effective for removing metal ions from solution, and the optimum pH range is between 5 and 7. The exchange rates are slower for the film than for bead and powder forms of the ion-exchange material; otherwise, the properties are similar. The film is effective when hard water solutions are employed and also when metal ions are in the complex matrix of waste water from electroplating. The film can be used in flow systems having a flow channel large enough to allow passage of turbid solutions.

  6. Properties of a Novel Ion-Exchange Film

    NASA Technical Reports Server (NTRS)

    Street, Kenneth W.; Hill, Carol M.; Philipp, Warren H.; Tanner, Stephen P.; Gorse, Joseph; Lusk, Amy; Taylor, Jason; Dickens, Jason

    2004-01-01

    A new ion-exchange material (based on polyacrylic acid) and some of its analytical applications have been reported. This paper contains data on the ion-exchange properties of the film form of the material and its potential application to the decontamination of waste water and drinking water. The film has a high exchange capacity of 5 to 6 meq/g and a pK(sub a) of 5.7. The calcium form is the most effective for removing metal ions from solution, and the optimum pH range is between 5 and 7. The exchange rates are slower for the film than for bead and powder forms of the ion-exchange material; otherwise, the properties are similar. The film is effective when hard water solutions are employed and also when metal ions are in the complex matrix of waste water from electroplating. The film can be used in flow systems having a flow channel large enough to allow passage of turbid solutions.

  7. Ion exchange and surface charge on montmorillonite clay

    SciTech Connect

    Sperry, J.M.; Peirce, J.J.

    1999-05-01

    An ion-exchange model originally developed for pure oxides prepared in the laboratory is extended to study of ion exchange and surface charge on a naturally occurring montmorillonite clay. The range of surface charges measured for montmorillonite with various electrolyte solutions and clay pretreatments is within the range of those measured for a wide variety of oxides prepared in the laboratory, including MnO{sub 2}-IC1, MnO{sub 2}-IC12, MnO{sub 2}-IC22, titanium dioxide, ferric oxide, and aluminum oxide. In addition, fitted parameter values for lateral interaction constants and equilibrium constants for the acid sites that characterize ion exchange on montmorillonite are on the same order of magnitude as those obtained for pure oxides. Surface charge of montmorillonite in sodium nitrate solution is measured to be approximately 15 to 25% greater than that measured between a pH of 4 and 9 in calcium chloride solution. This difference is attributed to the greater charge on the calcium (2{sup +}) ion; thus, its stronger electrostatic attraction to the acid hydroxyl site. An order of magnitude change in solids concentration (C{sub p}) can lead to a difference in measured net surface charge density of the same oxide sample of several orders of magnitude. This difference increases at higher pH, indicating the importance of reporting the corresponding C{sub p} at which experiments are conducted.

  8. Evaluation of Elution Parameters for Cesium Ion Exchange Resins

    SciTech Connect

    Burgeson, Ingrid E.; Deschane, Jaquetta R.; Cook, Bryan J.; Blanchard, David L.; Weier, Dennis R.

    2006-08-28

    Cesium ion exchange is one of the planned processes for treating and disposing of waste at the U.S. Department of Energy Hanford Site. Radioactive supernatant liquids from the waste tanks will undergo ultrafiltration, followed by cesium ion exchange using a regenerable organic ion exchange resin. Two resins, SuperLig?644 and a Resorcinol-formaldehyde resin are being evaluated for cesium removal and cesium elution characteristics. The main purpose of this study is to optimize the cesium elution to provide a resin which after undergoing elution would meet the U.S. Department of Energy/Office of River Protection Project-Waste Treatment Plant processing and resin disposal criteria. Columns of each resin type were loaded to greater or equal to 90% breakthrough with a Hanford waste stimulant and eluted with nitric acid. The temperature, flow rate and nitric acid concentration were varied to determine the optimal elution conditions. Temperature and eluant flow rate were the most important elution parameters. As would be predicted based upon kinetic consideration alone, decreasing the eluant flow rate and increasing the temperature provided the optimal elution conditions. Varying the nitric acid concentration did not have a significant effect on the elution; however, elutions performed using both high acid concentration (1M) and elevated temperature (45 C) resulted in resin degradation, causing gas generation and resin bed disruption.

  9. Removal of ammonium from municipal landfill leachate using natural zeolites.

    PubMed

    Ye, Zhihong; Wang, Jiawen; Sun, Lingyu; Zhang, Daobin; Zhang, Hui

    2015-01-01

    Ammonium ion-exchange performance of the natural zeolite was investigated in both batch and column studies. The effects of zeolite dosage, contact time, stirring speed and pH on ammonium removal were investigated in batch experiments. The result showed that ammonium removal efficiency increased with an increase in zeolite dosage from 25 to 150 g/L, and an increase in stirring speed from 200 to 250 r/min. But further increase in zeolite dosage and stirring speed would result in an unpronounced increase of ammonium removal. The optimal pH for the removal of ammonium was found as 7.1. In the column studies, the effect of flow rate was investigated, and the total ammonium removal percentage during 180 min operation time decreased with the flow rate though the ion-exchange capacity varied to a very small extent with the flow rate ranging from 4 to 9 mL/min. The spent zeolite was regenerated by sodium chloride solution and the ammonia removal capacity of zeolite changed little or even increased after three regeneration cycles. PMID:26510611

  10. Ion Exchange Temperature Testing with SRF Resin - 12088

    SciTech Connect

    Russell, R.L.; Rinehart, D.E.; Brown, G.N.; Peterson, R.A.

    2012-07-01

    Ion exchange using the Spherical Resorcinol-Formaldehyde (SRF) resin has been selected by the U.S. Department of Energy's Office of River Protection for use in the Pretreatment Facility of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) and for potential application in an at-tank deployment for removing Cs-137. Recent proposed changes to the WTP ion exchange process baseline indicate that higher temperatures (50 deg. C) to alleviate post-filtration precipitation issues prior to reaching the ion exchange columns may be required. Therefore, it is important to understand the behavior of SRF resin performance under the conditions expected with the new equipment and process changes. This research examined the impact of elevated temperature on resin loading and resin degradation during extended solution flow at elevated temperature (45 deg., 50 deg., 55 deg., 60 deg., 65 deg., 75 deg. C). Testing for extended times at elevated temperatures showed that the resin does degrade and loading capacity is reduced at and above 45 deg. C. Above 60 deg. C the resin appears to not load at all. It was observed that the resin disintegrated at 75 deg. C until not much was left and partially disintegrated at 65 deg. C, which caused the column to plug in both tests after ∼336 hours. The results indicate that WTP will lose resin loading capacity if the ion exchange process is performed above 25 deg. C, and the resin will disintegrate above 65 deg. C. Therefore, WTP will have a restricted operating range of temperatures to perform the ion exchange process with this resin. PNNL and WTP are currently evaluating the operating limits of the resin in further detail. Aging in 0.5 M HNO{sub 3} also caused the resin to lose capacity above 25 deg. C and to completely dissolve at 55 deg. C. Again, WTP will have a restricted operating range of temperatures when eluting the resin with nitric acid in order to maintain resin loading capacity and avoid disintegration of the resin

  11. Adsorption of hexane isomers on ion-exchanged mordenite

    SciTech Connect

    Huddersman, K.

    1996-10-01

    To remove lead from petrol and thereby promote a cleaner environment, other means must be found to keep the octane number or anti-knock qualities of the petrol high. It is found that this can be accomplished by increasing the proportion of highly branched chain hydrocarbon isomers in the fuel. This in turn promotes processes for the separation of the hydrocarbon isomers and in the case of hexane, it is an easy matter to separate out n-hexane from the more substituted isomers but it is difficult to separate out the mono- from the di-branched isomers. This work addresses itself to such challenging separations using modified zeolites as the separating agent, and by studying the heats of sorption of these isomers on zeolites using gas chromatographic techniques to find a trend in the potential abilities of these modified zeolites to effect a good separation. In this work mordenite zeolite was modified by a range of double cation exchanges and the resulting modified zeolites were investigated for their ability to sorb the hexane isomers 3-methylpentane and 2,3-dimethylbutane. These two isomers are closely related in size as they both have the same kinetic diameter of 0.56 nm. In this work only heats of sorption have been investigated and measurement of the diffusion coefficients, which also affect the ability of the modified zeolites to act as good separating agents, is currently under investigation.

  12. Smart epoxy coating containing Ce-MCM-22 zeolites for corrosion protection of Mg-Li alloy

    NASA Astrophysics Data System (ADS)

    Wang, Yanli; Zhu, Yanhao; Li, Chao; Song, Dalei; Zhang, Tao; Zheng, Xinran; Yan, Yongde; Zhang, Meng; Wang, Jun; Shchukin, Dmitry G.

    2016-04-01

    The epoxy coatings containing MCM-22 and Ce-MCM-22 zeolites were prepared by coating method on the Mg-Li alloy surface. The influence of MCM-22 and Ce-MCM-22 zeolites on corrosion protection of the epoxy coating was studied. The epoxy coating containing Ce-MCM-22 zeolites showed high corrosion resistance. Artificial defects in the epoxy coating containing Ce-MCM-22 zeolites on the Mg-Li surface were produced by the needle punching. The results show that the epoxy coating containing Ce-MCM-22 zeolites exhibits self-healing corrosion inhibition capabilities. It is ascribed to the fact that the Ce3+ ions are released from MCM-22 zeolites based on ion exchange of zeolite in the corrosion process of the Mg-Li alloy substrate. MCM-22 zeolites as reservoirs provided a prolonged release of cerium ions.

  13. Preliminary market analysis for large zeolite crystals. B.S. Thesis

    NASA Technical Reports Server (NTRS)

    Doblmaier, Thomas; Grafing, Paul; Knight, Kim

    1987-01-01

    Zeolite crystals are used in the manufacture of countless products today, which utilize their properties of absorption, ion exchange, and catalysis. It was determined that zeolites grown in space could be much larger in size than any of those currently available on Earth. The objective was to identify and examine some of the potential uses for these larger crystals. Of the several industries examined, the medical and nuclear industries offer the greatest potential.

  14. Vitrification of cesium-contaminated organic ion exchange resin

    SciTech Connect

    Sargent, T.N. Jr.

    1994-08-01

    Vitrification has been declared by the Environmental Protection Agency (USEPA) as the Best Demonstrated Available Technology (BDAT) for the permanent disposal of high-level radioactive waste. Savannah River Site currently uses a sodium tetraphenylborate (NaTPB) precipitation process to remove Cs-137 from a wastewater solution created from the processing of nuclear fuel. This process has several disadvantages such as the formation of a benzene waste stream. It has been proposed to replace the precipitation process with an ion exchange process using a new resorcinol-formaldehyde resin developed by Savannah River Technical Center (SRTC). Preliminary tests, however, showed that problems such as crust formation and a reduced final glass wasteform exist when the resin is placed in the melter environment. The newly developed stirred melter could be capable of overcoming these problems. This research explored the operational feasibility of using the stirred tank melter to vitrify an organic ion exchange resin. Preliminary tests included crucible studies to determine the reducing potential of the resin and the extent of oxygen consuming reactions and oxygen transfer tests to approximate the extent of oxygen transfer into the molten glass using an impeller and a combination of the impeller and an external oxygen transfer system. These preliminary studies were used as a basis for the final test which was using the stirred tank melter to vitrify nonradioactive cesium loaded organic ion exchange resin. Results from this test included a cesium mass balance, a characterization of the semi-volatile organic compounds present in the off gas as products of incomplete combustion (PIC), a qualitative analysis of other volatile metals, and observations relating to the effect the resin had on the final redox state of the glass.

  15. Ion Exchange Testing with SRF Resin FY2012

    SciTech Connect

    Russell, Renee L.; Rinehart, Donald E.; Peterson, Reid A.

    2013-06-11

    Ion exchange using spherical resorcinol-formaldehyde (SRF) resin has been selected by the U.S. Department of Energy’s Office of River Protection (DOE-ORP) for use in the Pretreatment Facility (PTF) of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) and for potential application in at-tank deployment. Numerous studies have shown SRF resin to be effective for removing 137Cs from a wide variety of actual and simulated tank waste supernatants (Adamson et al. 2006; Blanchard et al. 2008; Burgeson et al. 2004; Duignan and Nash 2009; Fiskum et al. 2006a; Fiskum et al. 2006b; Fiskum et al. 2006c; Fiskum et al. 2007; Hassan and Adu-Wusu 2003; King et al. 2004; Nash et al. 2006). Prior work at the Pacific Northwest National Laboratory (PNNL) has focused primarily on the loading behavior for 4 to 6 M Na solutions at 25 to 45°C. Recent proposed changes to the WTP ion exchange process baseline indicate that loading may include a broader range of sodium molarities (0.1 to 8 M) and higher temperatures (50°C) to alleviate post-filtration precipitation issues. This report discusses ion exchange loading kinetics testing activities performed in accordance with Test Plan TP-WTPSP-002, Rev. 3.0 , which was prepared and approved in response to the Test Specification 24590 PTF-TSP-RT-09-002, Rev. 0 (Lehrman 2010) and Test Exception 24590 PTF TEF RT-11-00003, Rev. 0 (Meehan 2011). This testing focused on column tests evaluating the impact of elevated temperature on resin degradation over an extended period of time and batch contacts evaluating the impact on Cs loading over a broad range of sodium concentrations (0.1 to 5 M). These changes may be required to alleviate post-filtration precipitation issues and broaden the data range of SRF resin loading under the conditions expected with the new equipment and process changes.

  16. MMI splitter by ion exchange on K9

    NASA Astrophysics Data System (ADS)

    Yuan, Jing; Luo, Fengguang; Cao, Mingcui; Chen, Wenmin

    2005-11-01

    A wavelength 0.85μm-based optical power splitter designed with Multi Mode Interference (MMI) by ion exchange on K9 glass was introduced. The waveguide material is K9 glass made in China and formed by K +-Na + pure melt salt ion exchange method. The grade index profile of planar ion-exchanged waveguide on K9 was studied and accorded with erfc function through compare of experimental and theoretic index profiles. The fabrication process of planar ionexchanged waveguide device was described. The basic theory of 1×8 MMI optical power splitter was illuminated by using guided-model propagation analysis. The working wavelength is 0.85μm, and the structure parameters of 1×8 MMI splitter were designed. The core pitch on this chip is chosen as 250μm to take the fiber connections into account, and the typical cladding diameter of optical fibers as 125μm. The critical parameters in the fabrication of the MMI power splitter are the multimode section width and length. In general the key performance specifications of the optical power splitter are insertion loss and uniformity. The output performances and the refractive index change's influence of the device were simulated by Bear Propagation Method (BPM). The uniformity was 0.93×10 -2dB, the average insertion loss was 9.12dB, and the maximal insertion loss was 9.14dB. The result shows that the advantages of the method include low loss, ease of fabrication, and low material cost.

  17. HEAT TRANSFER ANALYSIS FOR ION-EXCHANGE COLUMN SYSTEM

    SciTech Connect

    Lee, S.; King, W.

    2011-05-23

    Models have been developed to simulate the thermal characteristics of Crystalline Silicotitanate (CST) ion exchange media fully loaded with radioactive cesium in a column configuration and distributed within a waste storage tank. This work was conducted to support the Small Column Ion Exchange (SCIX) program which is focused on processing dissolved, high-sodium salt waste for the removal of specific radionuclides (including Cs-137, Sr-90, and actinides) within a High Level Waste (HLW) storage tank at the Savannah River Site. The SCIX design includes CST columns inserted and supported in the tank top risers for cesium removal. Temperature distributions and maximum temperatures across the column were calculated with a focus on process upset conditions. A two-dimensional computational modeling approach for the in-column ion-exchange domain was taken to include conservative, bounding estimates for key parameters such that the results would provide the maximum centerline temperatures achievable under the design configurations using a feed composition known to promote high cesium loading on CST. The current full-scale design for the CST column includes one central cooling pipe and four outer cooling tubes. Most calculations assumed that the fluid within the column was stagnant (i.e. no buoyancy-induced flow) for a conservative estimate. A primary objective of these calculations was to estimate temperature distributions across packed CST beds immersed in waste supernate or filled with dry air under various accident scenarios. Accident scenarios evaluated included loss of salt solution flow through the bed, inadvertent column drainage, and loss of active cooling in the column. The modeling results demonstrate that the baseline design using one central and four outer cooling tubes provides a highly efficient cooling mechanism for reducing the maximum column temperature.

  18. Experimental Determination of Thermodynamic Properties of Ion-Exchange in Heulandite: Binary Ion-Exchange Experiments at 55 and 85 oC Involving Ca2+, Sr2+, Na+, and K+

    SciTech Connect

    Fridriksson, T; Neuhoff, P S; Viani, B E; Bird, D K

    2004-04-26

    Heulandite is a common rock-forming zeolite that exhibits wide solid solution of extra framework cations, presumably due to ready ion exchange with aqueous solutions. In order to provide a quantitative basis for interpreting and predicting the distribution of aqueous species between heulandite and aqueous solutions, ion exchange equilibrium between heulandite and aqueous solutions with respect to the binary cation pairs Ca{sup 2+} - K{sup +}, Ca{sup 2+} - Na{sup +}, K{sup +} - Na{sup +}, K{sup +} - Sr{sup 2+}, Na{sup +} - Sr{sup 2+}, and Ca{sup 2+} - Sr{sup 2+} was investigated. Homoionic Ca-, K-, and Na-heulandites prepared from natural heulandite were equilibrated with 0.1 N Cl{sup -} solutions containing various proportions of the cations in a given binary pair at 55 and 85 C to define isotherms describing partitioning of the cations over a wide range of heulandite and solution composition with respect to the cations in each pair. In general, the experiments equilibrated rapidly, within 11-15 weeks at 55 C and 3-4 weeks at 85 C. The exception was the Ca{sup 2+} - Sr{sup 2+} binary exchange, which did not equilibrate even after 3 months at 55 C and 4 weeks at 85 C. Slow exchange of Sr{sup 2+} for Ca{sup 2+} also prohibited preparation of homoionic Sr-heulandite from the natural (Ca-rich) heulandite within 10 weeks in 2N SrCl{sub 2} solution at 90 C, although near homoionic Sr-heulandite was produced by exchange of K- and Na-heulandite. Experimentally determined isotherms were used to derive equilibrium constants for the ion exchange reactions and asymmetric Margules models describing the extent of non-ideality in extra framework solid solutions in heulandite. Regressed equilibrium constants for Ca{sup 2+}-Na{sup +}, Ca{sup 2+}-K{sup +}, and K{sup +}-Na{sup +} binary cation pairs at 55 C are internally consistent among each other (complying with the triangle rule), indicating good accuracy of these data. The maximum departure from internal Heulandite ion exchange

  19. Removal of Radioactive Nuclides by Multi-Functional Microcapsules Enclosing Inorganic Ion-Exchangers and Organic Extractants

    SciTech Connect

    Mimura, H.; Akiba, K.; Onodera, Y.

    2002-02-26

    The microcapsules enclosing two kinds of functional materials, inorganic ion-exchangers and organic extractants, were prepared by taking advantage of the high immobilization ability of alginate gel polymer. The fine powders of inorganic ion-exchanger and oil drops of extractant were kneaded with sodium alginate (NaALG) solution and the kneaded sol readily gelled in a salt solution of CaCl2, BaCl2 or HCl to form spherical gel particles. The uptake properties of various nuclides, 137Cs, 85Sr, 60Co, 88Y, 152Eu and 241Am, for thirty-four specimens of microcapsules in the presence of 10-1-10-4 M HNO3 were evaluated by the batch method. The distribution coefficient (Kd) of Cs+ above 103 cm3/g was obtained for the microcapsules enclosing CuFC or AMP. The Kd of Sr2+ around 102 cm3/g was obtained for the microcapsules containing clinoptilolite, antimonic acid, zeolite A, zeolite X or titanic acid. The microcapsules enclosing DEHPA exhibited relatively large Kd values of trivalent metal ions above 103 cm3/g; for example, the Kd values of Cs+, Sr2+, Co2+, Y3+, Eu3+ and Am3+ for a favorable microcapsule (CuFC/clinoptilolite/DEHPA/CaALG) were 1.1x104, 7.5x10, 1.1x10, 1.0x104, 1.4x104, 3.4x103 cm3/g, respectively. The uptake rates of Cs+, Y3+, Eu3+ and Am3+ for this microcapsule were rather fast; the uptake percentage above 90% was obtained after 19 h-shaking and the uptake equilibrium was attained within 1 d. The AMP/CaALG exhibited high uptake ability for Cs+ even after irradiation of 188 kGy, and DEHPA/CaALG microcapsule had similar Kd values of Cs+, Sr2+, Co2+, Y3+, Eu3+ and Am3+ ions before and after irradiation. The microcapsules with various shapes such as spherical, columnar, fibrous and filmy forms were easily prepared by changing the way of dipping kneaded sol into gelling salt solution. The microcapsules enclosing inorganic ion-exchangers and extractants have a potential possibility for the simultaneous removal of various radioactive nuclides from waste solutions.

  20. Clinoptilolite: A natural zeolite. (Latest citations from the NTIS database). Published Search

    SciTech Connect

    Not Available

    1993-03-01

    The bibliography contains citations concerning clinoptilolite, a natural, inorganic zeolite. Citations discuss the applications of clinoptilolite as a selective ion exchange medium used mainly for the removal of ammonia from waste water and effluents, and the treatment and disposal of radioactive waste. Mineralogy of clinoptilolite deposits is also presented. (Contains a minimum of 91 citations and includes a subject term index and title list.)

  1. Zeolite - A Natural Filter Material for Lead Polluted Water

    NASA Astrophysics Data System (ADS)

    Neamţu, Corina Ioana; Pică, Elena Maria; Rusu, Tiberiu

    2014-11-01

    Reducing the concentration of lead ions in a wastewater using zeolite has proven to be a successful water treatement method, all over the world. Putting the two media (solid and liquid) in contact in static conditions had good results regarding the concentration of the filtered solution, the pH and the electric conductivity, depending on the values of certain parameters such as the amount of the zeolite, volume of the solution or interaction time. The present study highlights the zeolite ability to retain the lead ions from a solution, in dynamic interaction conditions between the two environments, in a short interaction time. The results confirmed the effectiveness of ion exchange water treatment method in the conditions set, emphasizing once again the properties of the filter material - the zeolite

  2. Economical way to synthesize SSZ-13 with abundant ion-exchanged Cu+ for an extraordinary performance in selective catalytic reduction (SCR) of NOx by ammonia.

    PubMed

    Chen, Biaohua; Xu, Ruinian; Zhang, Runduo; Liu, Ning

    2014-12-01

    In this study, an economical way for SSZ-13 preparation with the essentially cheap choline chloride as template has been attempted. The as-synthesized SSZ-13 zeolite after ion exchange by copper nitrate solution exhibited a superior SCR performance (over 95% NOx conversion across a broad range from 150 to 400 °C) to the traditional zeolite-based catalysts of Cu-Beta and Cu-ZSM-5. Furthermore, the opportune size of pore opening (∼3.8 Å) made Cu-SSZ-13 exhibiting the best selectivity to N2 as well as satisfactory tolerance toward SO2 and C3H6 poisonings. The characterization (XRD, XPS, XRF, and H2-TPR) of samples confirmed that Cu-SSZ-13 possessed the most abundant Cu cations among three investigated Cu-zeolites; furthermore, either on the surface or in the bulk the ratio of Cu(+)/Cu(2+) ions for Cu-SSZ-13 is also the highest. New finding was announced that CHA-type topology is in favor of the formation of copper cations, especially generating much more Cu(+) ions than the others, rather than CuO. The activity test of Cu(CuCl)-ZSM-5 (prepared by a solid-state ion-exchange method) clearly indicated that Cu(+) ions could make a major contribution to the low-temperature deNOx activity. The activity of protonic zeolites (H-SSZ-13, H-Beta, H-ZSM-5) revealed the topology effect on SCR performances. PMID:25365767

  3. Evaluation of Ion Exchange Materials in K Basin Floor Sludge and Potential Solvents for PCB Extraction from Ion Exchange Materials

    SciTech Connect

    Schmidt, A.J.; Klinger, G.S.; Bredt, P.R.

    1999-04-10

    Approximately 73 m{sup 3} of heterogeneous solid material, ''sludge,'' (upper bound estimate, Packer 1997) have accumulated at the bottom of the K Basins in the 100 K Area of the Hanford Site. This sludge is a mixture of spent fuel element corrosion products, ion exchange materials (organic and inorganic), graphite-based gasket materials, iron and aluminum metal corrosion products, sand, and debris (Makenas et al. 1996, 1997). In addition, small amounts of polychlorinated biphenyls (PCBs) have been found. These small amounts are significant from a regulatory standpoint. Ultimately, it is planned to transfer the K Basins sludge to the Hanford double shell tanks (DSTs). Chemical pretreatment is required to address criticality issues and the destruction or removal of PCBs before the K Basin sludge can be transferred to the DSTs. Eleven technologies have been evaluated (Papp 1997) as potential pretreatment methods. Based on the evaluations and engineering studies and limited testing, Fluor Daniel Hanford recommended solvent washing of the K Basin sludge, followed by nitric acid dissolution and, potentially, peroxide addition (FDH 1997). The solvent washing (extraction) and peroxide addition would be used to facilitate PCB removal and destruction. Following solvent extraction, the PCBs could be distilled and concentrated for disposal as a low-level waste. The purpose of the work reported here was to continue investigating solvent extraction, first by better identifying the ion exchange materials in the actual sludge samples and then evaluating various solvents for removing the PCBs or possibly dissolving the resins. This report documents some of the process knowledge on ion exchange materials used and spilled in the K Basins and describes the materials identified from wet sieving KE Basin floor and canister sludge and the results of other analyses. Several photographs are included to compare materials and illustrate material behavior. A summary of previous tests on

  4. Understanding Mechanism and Designing Strategies for Sustainable Synthesis of Zeolites: A Personal Story.

    PubMed

    Wang, Yeqing; Xiao, Feng-Shou

    2016-06-01

    Zeolites with intricate micropores have been widely studied for a long time as an important class of porous materials in different areas of industrial processes such as gas adsorption and separation, ion exchange, and shape-selective catalysis. However, their industrial syntheses are not sustainable, and normally require the presence of expensive organic templates and a large amount of solvents such as water. The presence of organic templates not only increases zeolite cost but also produces harmful gases during the removal of these templates by calcination, while the use of solvents significantly increases the amount of polluted water. This Personal Account briefly summarizes recent sustainable routes for the synthesis of zeolites in our group according to our understanding of the synthetic mechanism, and mainly focuses on the organotemplate-free synthesis of zeolites in the presence of zeolite seeds, the design of environmentally friendly templates, and solvent-free synthesis of zeolites. PMID:27009872

  5. Ion exchange at the critical point of solution.

    PubMed

    Savoy, J D; Baird, J K; Lang, J R

    2016-03-11

    A mixture of isobutyric acid (IBA)+water has an upper critical point of solution at 26.7°C and an IBA concentration of 4.40M. We have determined the Langmuir isotherms for the hydroxide form of Amberlite IRN-78 resin in contact with mixtures of IBA+water at temperatures, 27.0, 29.0, 31.0 and 38.0°C, respectively. The Langmuir plot at 38.0°C forms a straight line. At the three lower temperatures, however, a peak in the Langmuir plot is observed for IBA concentrations in the vicinity of 4.40M. We regard this peak to be a critical effect not only because it is located close to 4.40M, but also because its height becomes more pronounced as the temperature of the isotherm approaches the critical temperature. For concentrations in the vicinity of the peak, the data indicate that the larger isobutyrate ion is rejected by the resin in favor of the smaller hydroxide ion. This reversal of the expected ion exchange reaction might be used to separate ions according to size. Using the Donnan theory of ion exchange equilibrium, we link the swelling pressure to the osmotic pressure. We show that the peak in the Langmuir plot is associated with a maximum in the "osmotic" energy. This maximum has its origin in the concentration derivative of the osmotic pressure, which goes to zero as the critical point is approached. PMID:26884137

  6. Epitactic ion-exchange reactions into vanadyl(IV) arsenate

    SciTech Connect

    Martinez-Lara, M.; Bruque, S.; Moreno, L.; Aranda, M.A.G. )

    1991-03-01

    The synthesis, structural characterization, thermal stability, and spectroscopic (IR, UV-vis-diffuse reflectance) properties of three vanadyl arsenates are described. Vanadyl(IV) bis(dihydrogenarsenate), (VO(H{sub 2}AsO{sub 4}){sub 2}) (1), lithium vanadyl arsenate, (Li{sub 4}VO(AsO{sub 4}){sub 2}{center dot}0.5H{sub 2}O) (2), and nickel(II) and lithium vanadyl arsenate, ((Li{sub 2.4}Ni){sub 0.8}VO(AsO{sub 4}){sub 2}{center dot}4H{sub 2}O) (3), have been prepared. (1) Tetragonal ({alpha} = 9.128 {angstrom}; c = 8.128 {angstrom}) is prepared by reduction with isobutanol or ethanol from vanadyl(V) arsenate. (2) Cubic (a = 9.024 {angstrom}) is obtained from (1) by lithium ion-exchange, and (3) tetragonal (a = 9.106 {angstrom}; c = 8.454 {angstrom}) is made from (2) by Ni{sup 2+} ion-exchange. These exchange reactions are epitactic and the overall result is a topotactic transformation.

  7. Small Column Ion Exchange Monitor System Final Report

    SciTech Connect

    CASELLA, VITO

    2004-09-30

    A Small Column Ion Exchange (SCIX) system has been designed by the Oak Ridge and Savannah River National Laboratories (ORNL and SRNL) as a potential way to reduce Cs-137 concentrations in high-level radioactive waste at the Savannah River Site. SRNL was asked to develop gamma-ray monitors at six locations within the SCIX system. Gamma-ray monitors are required to verify the proper operation of the ion exchange system, detect cesium breakthrough, and confirm presence of cesium before and after used resin is transferred to a grinder module. The only observable gamma ray in the decay of Cs-137 is from its short-lived Ba-137m daughter. Chemical processes, such as the SCIX, may disrupt the secular equilibrium between this parent-daughter pair; meaning that measurement of Ba-137m will not necessarily yield information about Cs-137 content. While this is a complicating factor that can not be ignored, it is controllable by either: allowing sufficient time for equilibrium to be reestablished (about 20 minutes), or by making multiple measurements with sufficient statistical precision to determine the extent of disequilibrium. The present work provides a means of measuring the Cs-137 and Ba-137m by taking multiple measurements in a process isolation loop that contains the process solution of interest.

  8. Data quality objectives for Ion Exchange Module (IXM) disposition

    SciTech Connect

    Choi, I.

    1995-01-31

    This Data Quality Objective (DQO) document presents the data needs and accuracy requirements for sampling ion exchange modules at the K Basins, 100 K Area, to determine if there is a hydrogen gas buildup within the modules. This document was produced by PNL, with the assistance of Neptune and Associates, and was partly funded (for facilitator) by DOE-HQ as a demonstration DQO for EM activities. PNL involved a number of PNL, WHC and support contract staff (including external technical consultants) in meetings to define the data needed, along with the necessary accuracy, to resolve issues associated with hydrogen accumulation in Ion Exchange Modules (IXMS) that were generated prior to July 1994 and only have one nuc-fil vent. IXMs generated after July 1994 have multiple nuc-fil vents and do not require sampling. PNL transmitted this DQO to WHC on January 31, 1995. This Supporting Document is to assure that the document is captured into the document retrieval system. WHC review focused on the acceptability of the technical conclusions such that the data collected will meet minimum operational, safety and environmental needs.

  9. Continuous ion exchange separation of zirconium and hafnium

    SciTech Connect

    Begovich, J.M.; Sisson, W.G.

    1981-01-01

    A pressurized continuous annular chromatograph (CAC) has been developed for truly continuous ion exchange preparative separations. This device utilizes a slowly rotating annular bed of sorbent material, fixed multiple feed points, and fixed withdrawal locations. Most of our investigations have been performed with a 28-cm-diam by 60-cm-long CAC, but a larger model has recently been designed and constructed. A detailed study has been made of the separation of copper, nickel, and cobalt components from a simulated carbonate leach liquor of the Caron process for recovering nickel and cobalt from laterite ores. Recent studies have investigated the ion exchange separation of zirconium and hafnium from a sulfate feed solution. Nuclear reactor-grade zirconium, containing < 0.01 wt % hafnium, and hafnium, containing < 1% zirconium, have been continuously prepared using cation exchange resin in the pressurized CAC. This device, because of its continuous feed and product withdrawal, its adaptability to largescale operations, and its ability to separate many components, is expected to make chromatography a more competitive process in the industrial sector.

  10. Enigmatic ion-exchange behavior of myo-inositol phosphates.

    PubMed

    Shelor, C Phillip; Liao, Hongzhu; Kadjo, Akinde Florence; Dasgupta, Purnendu K

    2015-05-01

    The separation of myo-inositol mono-, di-, tri-, tetra-, pentakis-, and hexakisphosphate (InsP1, InsP2, InsP3, InsP4, InsP5, InsP6) was carried out using hydroxide eluent ion chromatography. Acid hydrolysis of InsP6 (phytate) was used to prepare a distribution of InsPs, ranging from InsP1 to InsP5's and including unhydrolyzed InsP6. Counting all possible positional isomers (many of which have stereoisomers that will not be separable by conventional ion exchange), 40 chromatographically separable peaks are possible; up to 22 were separated and identified by mass spectrometry. InsPs show unusual ion-exchange behavior in two respects: (a) the retention order is not monotonically related with the charge on the ion and (b) at the same hydroxide eluent concentration, retention is greatly dependent on the eluent metal cation. The retention of InsP3-InsP6 was determined to be controlled by steric factors while elution was influenced by eluent cation complexation. These highly phosphorylated InsPs have a much greater affinity for alkali metals (Li(+) > Na(+) > K(+)) than quaternary ammonium ions. This difference in cation affinity was exploited to improve separation through the use of a tetramethylammonium hydroxide-sodium hydroxide gradient. PMID:25865157

  11. Low-level liquid waste decontamination by ion exchange

    SciTech Connect

    Campbell, D.O.; Lee, D.D.; Dillow, T.A.

    1991-12-01

    Improved processes are being developed to treat contaminated liquid wastes that have been and continue to be generated at Oak Ridge National Laboratory. Both inorganic and organic ion-exchange methods have given promising results. Nickel and cobalt hexacyanoferrate(2) compounds are extremely selective for cesium removal, with distribution coefficients in excess of 10{sup 6} and remarkable insensitivity to competition from sodium and potassium. They tend to lose effectiveness at pH > {approximately}11, but some formulations are useful for limited periods of time up to pH {approximately}13. Sodium titanate is selective for strontium removal at high pH. The separations are so efficient that simple batch processes can yield large decontamination factors while generating small volumes of solid waste. A resorcinol-based resin developed at the Savannah River Site gave superior cesium removal, compared with other organic ion exchangers; the distribution coefficient was limited primarily by competition from potassium and was nearly independent of sodium. The optimum pH was {approximately}12.5. It was much less effective for strontium removal, which was limited by competition from sodium. 8 refs., 6 figs., 9 tabs.

  12. Changes in the Vibrational Spectra of Zeolites Due to Sorption of Heavy Metal Cations

    NASA Astrophysics Data System (ADS)

    Król, M.; Mozgawa, W.; Barczyk, K.; Bajda, T.; Kozanecki, M.

    2013-11-01

    This work presents the results of spectroscopic (MIR and Raman) studies of zeolite structures after immobilization of heavy metal cations from aqueous solutions. The sorption of Ag+, Cu2+, Cd2+, Pb2+, Zn2+, and Cr3+ ions has been conducted on zeolites belonging to different structural groups, i.e., sodium forms of natural chabazite, mordenite, ferrierite, and clinoptilolite, as well as on synthetic zeolite Y. Systematic changes in intensities and positions of the bands corresponding to the characteristic ring vibrations have been observed in the measured spectra. The most visible changes are observed in the FT-IR spectra of the samples in the range of 850-450 cm-1, and in the Raman spectra in the range of 600-250 cm-1. Depending on the zeolite structure, the bands, which can be regarded as a kind of indicator of ion exchange, were indentifi ed. For example, in the case of IR spectra, these bands are at 766, 703, 648, 578, and 506 cm-1 for zeolite Y, at 733 and 560 cm-1 for mordenite, at 675 cm-1 for clinoptilolite, etc. The degree of changes depends on both the type of cation and its concentration in the initial solution. This is connected with the way of binding of metal ions to the zeolite aluminosilicate framework, i.e., a proportion of the ion exchange and chemisorption in the process. Cations mainly undergoing ion exchange, such as Cd2+ or Pb2+, have the greatest impact on the character of the spectra. On the other hand, Cr3+ ions practically do not modify the spectra of zeolites. Results of IR and Raman spectroscopic studies have been compared with those obtained by atomic absorption spectroscopy (AAS), from which the proportion of ion exchange to chemisorption in the process and the effective cation exchange capacity of the individual samples have been estimated.

  13. Oxidative regeneration of toluene-saturated natural zeolite by gaseous ozone: the influence of zeolite chemical surface characteristics.

    PubMed

    Alejandro, Serguei; Valdés, Héctor; Manéro, Marie-Hélène; Zaror, Claudio A

    2014-06-15

    In this study, the effect of zeolite chemical surface characteristics on the oxidative regeneration of toluene saturated-zeolite samples is investigated. A Chilean natural zeolite (53% clinoptilolite, 40% mordenite and 7% quartz) was chemically modified by acid treatment with hydrochloric acid and by ion-exchange with ammonium sulphate. Thermal pre-treatments at 623 and 823K were applied and six zeolite samples with different chemical surface characteristics were generated. Chemical modification of natural zeolite followed by thermal out-gassing allows distinguishing the role of acidic surface sites on the regeneration of exhausted zeolites. An increase in Brønsted acid sites on zeolite surface is observed as a result of ammonium-exchange treatment followed by thermal treatment at 623K, thus increasing the adsorption capacity toward toluene. High ozone consumption could be associated to a high content of Lewis acid sites, since these could decompose ozone into atomic active oxygen species. Then, surface oxidation reactions could take part among adsorbed toluene at Brønsted acid sites and surface atomic oxygen species, reducing the amount of adsorbed toluene after the regenerative oxidation with ozone. Experimental results show that the presence of adsorbed oxidation by-products has a negative impact on the recovery of zeolite adsorption capacity. PMID:24794812

  14. Cu-Na ion exchange soda-lime glass planar waveguides and their photoluminescence

    NASA Astrophysics Data System (ADS)

    Ti, Yunqiang; He, Xin; Zhang, Jian; Zheng, Jie; Wang, Pengfei; Farrell, Gerald

    2009-11-01

    Copper ion exchange technique was used to fabricate soda-lime glass planar waveguides. Prism coupling method was applied to measure the effective indices, and the refractive index profiles were reconstructed through Inverse WKB (IWKB) method. Optical absorption and photoluminescence analysis were carried out as well. The emission spectra centered at 520nm are attributed to Cu+ located in distorted octahedral sites. It was found that the ion exchange time and temperature both play an important role in the waveguides luminescence properties. The emission spectra intensities decrease with the ion exchange time increasing. The emission peak wavelength slightly blue shifts as the ion-exchange time increasing as well. The emission band intensity nearly increases consistently with the ion-exchange temperature increasing within proper ion-exchange time. Different excitation wavelengths were tested as well in order to study the site effect on photoluminescence properties.

  15. Ammonium removal from high-strength aqueous solutions by Australian zeolite.

    PubMed

    Wijesinghe, D Thushari N; Dassanayake, Kithsiri B; Sommer, Sven G; Jayasinghe, Guttila Y; J Scales, Peter; Chen, Deli

    2016-07-01

    Removal of ammonium nitrogen (NH4(+)-N) particularly from sources which are highly rich in nitrogen is important for addressing environmental pollution. Zeolites, aluminosilicate minerals, are commonly used as commercial adsorbents and ion-exchange medium in number of commercial applications due to its high adsorption capacity of ammonium (NH4(+)). However, detailed investigations on NH4(+) adsorption and ion exchange capacities of Australian natural zeolites are rare, particularly under higher NH4(+) concentrations in the medium. Therefore, this study was conducted to determine NH4(+) adsorption characteristics of Australian natural zeolites at high NH4(+) concentrations with and without other chemical compounds in an aqueous solution. Results showed that initial NH4(+) concentration, temperature, reaction time, and pH of the solution had significant effects on NH4(+) adsorption capacity of zeolite. Increased retention time and temperature generally had a positive impact on adsorption. Freundlich model fitted well with adsorption process of Australian natural zeolites; however, Langmuir model had best fitted for the adsorption process of sodium (Na(+)) treated zeolites. NaCl treatment increased the NH4(+) adsorption capacity of Australian zeolites by 25% at 1000 mg-N, NH4(+) solution. The maximum adsorption capacity of both natural Australian zeolites and Na(+) treated zeolites were estimated as 9.48 and 11.83 mg-N/g, respectively, which is lower than many zeolites from other sources. Compared to the NH4(+) only medium, presence of other competitive ions and acetic acid in the medium (resembling composition in digested swine manure slurries) reduced NH4(+) removal of natural and Na(+) treated zeolites by 44% and 57%, respectively. This suggests detailed investigations are required to determine practically achievable NH4(+) -N removal potential of zeolites for applications in complex mediums such as animal manure slurries. PMID:27050255

  16. Ion exchange resins. (Latest citations from the US Patent bibliographic file with exemplary claims). Published Search

    SciTech Connect

    Not Available

    1994-04-01

    The bibliography contains citations concerning preparation, regeneration, and applications of ion exchange resins. Applications include water and waste treatment; food processing; chemical recovery, separation, purification, and catalysis; desalination; and ore treatment and recovery. Methods are included for the processing of spent ion exchange resins and for protecting ion exchange resins from oxidation and chemical degradation. (Contains 250 citations and includes a subject term index and title list.)

  17. Fixation of radioactive ions in porous media with ion exchange gels

    DOEpatents

    Mercer, Jr., Basil W.; Godfrey, Wesley L.

    1979-01-01

    A method is provided for fixing radioactive ions in porous media by injecting into the porous media water-soluble organic monomers which are polymerizable to gel structures with ion exchange sites and polymerizing the monomers to form ion exchange gels. The ions and the particles of the porous media are thereby physically fixed in place by the gel structure and, in addition, the ions are chemically fixed by the ion exchange properties of the resulting gel.

  18. Planar optical waveguides fabricated by Ag+/K+-Na+ ion exchange in soda lime glass

    NASA Astrophysics Data System (ADS)

    Marzuki, Ahmad; Gregorius, Seran Daton; Widhianingsih, Ika; Lestari, Siti; Suryawan, Joko

    2015-12-01

    This paper reports the optical properties of the optical planar waveguides in a soda lime glass fabricated by ion exchange. Planar waveguide fabrication was carried out by immersing the soda lime glass in molten 100 % AgNO3 bath for different duration (ranging from 15 minutes to 735 minutes) and at temperature of 280°C. The results show that the surface refractive index values of the ion exchanged glasses are independent of both the ion exchange duration and temperature. The number of modes and the effective diffusion depth, however, increase with increasing the duration of ion exchange process.

  19. Closed cycle ion exchange method for regenerating acids, bases and salts

    DOEpatents

    Dreyfuss, Robert M.

    1976-01-01

    A method for conducting a chemical reaction in acidic, basic, or neutral solution as required and then regenerating the acid, base, or salt by means of ion exchange in a closed cycle reaction sequence which comprises contacting the spent acid, base, or salt with an ion exchanger, preferably a synthetic organic ion-exchange resin, so selected that the counter ions thereof are ions also produced as a by-product in the closed reaction cycle, and then regenerating the spent ion exchanger by contact with the by-product counter ions. The method is particularly applicable to closed cycle processes for the thermochemical production of hydrogen.

  20. Small Column Ion Exchange Design and Safety Strategy

    SciTech Connect

    Huff, T.; Rios-Armstrong, M.; Edwards, R.; Herman, D.

    2011-02-07

    Small Column Ion Exchange (SCIX) is a transformational technology originally developed by the Department of Energy (DOE) Environmental Management (EM-30) office and is now being deployed at the Savannah River Site (SRS) to significantly increase overall salt processing capacity and accelerate the Liquid Waste System life-cycle. The process combines strontium and actinide removal using Monosodium Titanate (MST), Rotary Microfiltration, and cesium removal using Crystalline Silicotitanate (CST, specifically UOP IONSIV{reg_sign}IE-911 ion exchanger) to create a low level waste stream to be disposed in grout and a high level waste stream to be vitrified. The process also includes preparation of the streams for disposal, e.g., grinding of the loaded CST material. These waste processing components are technically mature and flowsheet integration studies are being performed including glass formulations studies, application specific thermal modeling, and mixing studies. The deployment program includes design and fabrication of the Rotary Microfilter (RMF) assembly, ion-exchange columns (IXCs), and grinder module, utilizing an integrated system safety design approach. The design concept is to install the process inside an existing waste tank, Tank 41H. The process consists of a feed pump with a set of four RMFs, two IXCs, a media grinder, three Submersible Mixer Pumps (SMPs), and all supporting infrastructure including media receipt and preparation facilities. The design addresses MST mixing to achieve the required strontium and actinide removal and to prevent future retrieval problems. CST achieves very high cesium loadings (up to 1,100 curies per gallon (Ci/gal) bed volume). The design addresses the hazards associated with this material including heat management (in column and in-tank), as detailed in the thermal modeling. The CST must be size reduced for compatibility with downstream processes. The design addresses material transport into and out of the grinder and

  1. Cesium Ion Exchange Loading Kinetics Testing with SRF Resin

    SciTech Connect

    Russell, Renee L.; Rinehart, Donald E.; Brown, Garrett N.; Peterson, Reid A.

    2012-11-02

    Ion exchange using the Spherical Resorcinol-Formaldehyde (SRF) resin has been selected by the U.S. Department of Energy’s Office of River Protection for use in the Pretreatment Facility of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) and for potential application in an at-tank deployment for removing 137Cs. Recent proposed changes to the WTP ion exchange process baseline indicate that loading may include a broader range of sodium molarities (2 to 8 M) due to caustic leaching and higher temperatures (50°C) to alleviate post-filtration precipitation issues prior to reaching the ion exchange columns. Therefore, it is important to understand the behavior of SRF resin performance under the conditions expected with the new equipment and process changes. This research examined the impact of linear load velocity (4, 6, 8 cm/min), initial sodium concentration (2, 5, 8 M), initial sodium-to-cesium ratio (1.4E+05, 2.1E+05, 2.8E+05 mol/mol), initial sodium-to-hydroxide ratio (2.0, 3.0, 4.0 mol/mol), and resin degradation during extended solution flow using elevated temperature (45°, 50°, 55°, 60°, 65°, 75°C). Testing was performed using a~2mL column packed with SRF resin with feed flowing through it in an up-flow pattern. Samples were taken at set intervals and the data analyzed to help understand the impact of these conditions on the SRF resin performance. It was found that the loading kinetics were not significantly impacted by the sodium concentration over the range tested. However, the loading kinetics were impacted by the linear load velocity. These results indicated that at the test temperature, the adsorption of cesium is strongly dependent on mass transfer through the film and not significantly impacted by interparticle diffusion. Testing for extended times at elevated temperatures showed that the resin does degrade and loading capacity is reduced at and above 45°C. Above 60°C the resin appears to not load at all.

  2. Ion Exchange Testing with SRF Resin FY 2012

    SciTech Connect

    Russell, Renee L.; Rinehart, Donald E.; Peterson, Reid A.

    2014-07-02

    Ion exchange using spherical resorcinol-formaldehyde (SRF) resin has been selected by the U.S. Department of Energy’s Office of River Protection (DOE-ORP) for use in the Pretreatment Facility (PTF) of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) and for potential application in at-tank deployment. Numerous studies have shown SRF resin to be effective for removing 137Cs from a wide variety of actual and simulated tank waste supernatants (Adamson et al. 2006; Blanchard et al. 2008; Burgeson et al. 2004; Duignan and Nash 2009; Fiskum et al. 2006a; Fiskum et al. 2006b; Fiskum et al. 2006c; Fiskum et al. 2007; Hassan and Adu-Wusu 2003; King et al. 2004; Nash et al. 2006). Prior work at the Pacific Northwest National Laboratory (PNNL) has focused primarily on the loading behavior for 4 to 6 M Na solutions at 25 to 45°C. Recent proposed changes to the WTP ion exchange process baseline indicate that loading may include a broader range of sodium molarities (0.1 to 8 M) and higher temperatures (50°C) to alleviate post-filtration precipitation issues. This report discusses ion exchange loading kinetics testing activities performed in accordance with Test Plan TP-WTPSP-002, Rev. 3.01, which was prepared and approved in response to the Test Specification 24590-PTF-TSP-RT-09-002, Rev. 0 (Lehrman 2010) and Test Exception 24590-PTF-TEF-RT-11-00003, Rev. 0 (Meehan 2011). This testing focused on column tests evaluating the impact of elevated temperature on resin degradation over an extended period of time and batch contacts evaluating the impact on Cs loading over a broad range of sodium concentrations (0.1 to 5 M). These changes may be required to alleviate post-filtration precipitation issues and broaden the data range of SRF resin loading under the conditions expected with the new equipment and process changes.

  3. Synthesis and characterization of nitrogen substituted zeolites

    NASA Astrophysics Data System (ADS)

    Dogan, Fulya

    The interest in basic solid materials, particularly for basic zeolites has considerably increased in the last two decades because of their potential use in catalysis and separation. Basic zeolites have most often been obtained by ion-exchange or impregnation with alkali metal cations or grafting of organic bases onto zeolite pore walls. Such materials often suffer from instability and/or pore blockage, because none of these approaches places basic sites directly into the zeolite framework. Recently zeolitic materials have been made with some of the bridging oxygen atoms in Si--O--Si and/or Si--O--Al linkages replaced by NH groups, i.e. by substitution of framework oxygen by nitrogen. As a result, the basic strength of the framework increases due to the lower electronegativity of nitrogen with respect to oxygen. In this study, solid base catalysts are obtained by nitrogen substitution of the faujasite type of zeolites under ammonia flow at high temperatures. The efficiency of the reaction is tested by using zeolites with different aluminum contents and extraframework cations and varying the reaction conditions such as ammonia flow rate, reaction temperature and duration. The characterization studies show that high levels of nitrogen substitution can be achieved while maintaining porosity, particularly for NaY and low-aluminum HY zeolites, without a significant loss in the crystallinity. 27Al and 29 Si MAS NMR experiments performed on the nitrogen substituted zeolites show dealumination of the framework and preferential substitution for Si--OH--Al sites at the early stages of the reaction (temperatures at 750--800 °C). No preference is seen for reactions performed at higher temperatures and longer reaction times (e.g., 850 °C and 48 h). X-ray PDF analysis performed on the modified zeolites show that the Si-N distance in the 1st shell is longer than Si-O bond distance and Si-Si/Al bond distance of the Si-O/N-Si/Al linkage decreases, as an indication of a decrease in

  4. Copper ion-exchanged channel waveguides optimization for optical trapping.

    PubMed

    Reshak, A H; Khor, K N; Shahimin, M M; Murad, S A Z

    2013-08-01

    Optical trapping of particles has become a powerful non-mechanical and non-destructive technique for precise particle positioning. The manipulation of particles in the evanescent field of a channel waveguide potentially allows for sorting and trapping of several particles and cells simultaneously. Channel waveguide designs can be further optimized to increase evanescent field prior to the fabrication process. This is crucial in order to make sure that the surface intensity is sufficient for optical trapping. Simulation configurations are explained in detail with specific simulation flow. Discussion on parameters optimization; physical geometry, optical polarization and wavelength is included in this paper. The effect of physical, optical parameters and beam spot size on evanescent field has been thoroughly discussed. These studies will continue toward the development of a novel copper ion-exchanged waveguide as a method of particle sorting, with biological cell propulsion studies presently underway. PMID:23726859

  5. Electrically switched cesium ion exchange. FY 1996 annual report

    SciTech Connect

    Lilga, M.A.; Orth, R.J.; Sukamto, J.P.H.; Schwartz, D.T.; Haight, S.M.; Genders, D.

    1996-12-01

    An electrochemical method for metal ion separations, called Electrically Switched Ion Exchange, is described. Direct oxidation and reduction of an electroactive film attached to an electrode surface is used to load and unload the film with alkali metal cations. The electroactive films under investigation are Ni hexacyanoferrates, which are deposited on the surface by applying an anodic potential to a Ni electrode in a solution containing the ferricyanide anion. Reported film preparation procedures were modified to produce films with improved capacity and stability. Electrochemical behavior of the derivatized electrodes were investigated using cyclic voltammetry and chronocoulometry. The films show selectivity for Cs in concentrated sodium solutions. Raman spectroscopy was used to monitor changes in oxidation state of the film and imaging experiments have demonstrated that the redox reactions are spatially homogenous across the film. Requirements for a bench scale unit were identified.

  6. Advanced integrated solvent extraction and ion exchange systems

    SciTech Connect

    Horwitz, P.

    1996-10-01

    Advanced integrated solvent extraction (SX) and ion exchange (IX) systems are a series of novel SX and IX processes that extract and recover uranium and transuranics (TRUs) (neptunium, plutonium, americium) and fission products {sup 90}Sr, {sup 99}Tc, and {sup 137}Cs from acidic high-level liquid waste and that sorb and recover {sup 90}Sr, {sup 99}Tc, and {sup 137}Cs from alkaline supernatant high-level waste. Each system is based on the use of new selective liquid extractants or chromatographic materials. The purpose of the integrated SX and IX processes is to minimize the quantity of waste that must be vitrified and buried in a deep geologic repository by producing raffinates (from SX) and effluent streams (from IX) that will meet the specifications of Class A low-level waste.

  7. ION EXCHANGE PROCESS FOR THE RECOVERY AND PURIFICATION OF MATERIALS

    DOEpatents

    Long, R.S.; Bailes, R.H.

    1958-04-15

    A process for the recovery of certain metallic ions from aqueous solutions by ion exchange techniques is described. It is applicable to elements such as vanadium, chromium, nnanganese, and the like, which are capable of forming lower valent cations soluble in aqueous solutions and which also form ldgher valent anions soluble in aqueous acidic solutions. For example, small amounts of vanadium occurring in phosphoric acid prepared from phosphate rock may be recovered by reducing the vanadium to a trivalent cation adsorbing; the vanadium in a cationic exchange resin, then treating the resin with a suitable oxidizing agent to convert the adsorbed vanadium to a higher valent state, and finally eluting; the vanadium as an anion from the resin by means of an aqueous acidic solution.

  8. ION EXCHANGE SUBSTANCES BY SAPONIFICATION OF ALLYL PHOSPHATE POLYMERS

    DOEpatents

    Kennedy, J.

    1959-04-14

    An ion exchange resin having a relatively high adsorption capacity tor uranyl ion as compared with many common cations is reported. The resin comprises an alphyl-allyl hydrogen phosphate polymer, the alphyl group being either allyl or a lower alkyl group having up to 5 carbon atoins. The resin is prepared by polymerizing compounds such as alkyl-diallyl phosphate and triallyl phosphate in the presence of a free radical generating substance and then partially hydrolyzing the resulting polymer to cause partial replacement of organic radicals by cations. A preferred free radical gencrating agent is dibenzoyl peroxide. The partial hydrolysis is brought about by refluxing the polymer with concentrated aqueous NaOH for three or four hours.

  9. Electrodialysis-ion exchange for the separation of dissolved salts

    SciTech Connect

    Baroch, C.J.; Grant, P.J.

    1995-12-31

    The Department of Energy generates and stores a significant quantity of low level, high level, and mixed wastes. As some of the DOE facilities are decontaminated and decommissioned, additional and possibly different forms of wastes will be generated. A significant portion of these wastes are aqueous streams containing acids, bases, and salts, or are wet solids containing inorganic salts. Some of these wastes are quite dilute solutions, whereas others contain large quantities of nitrates either in the form of dissolved salts or acids. Many of the wastes are also contaminated with heavy metals, radioactive products, or organics. Some of these wastes are in storage because a satisfactory treatment and disposal processes have not been developed. This report describes the process of electrodialysis-ion exchange (EDIX) for treating aqueous wastes streams consisting of nitrates, sodium, organics, heavy metals, and radioactive species.

  10. Electrotransportation of aniline through a perfluorosulfonate ion-exchange membrane

    SciTech Connect

    Katakura, Katsumi . Dept. of Chemical Engineering); Inaba, Minoru; Toyama, Koji; Ogumi, Zempachi; Takehara, Zenichiro . Division of Energy and Hydrocarbon Chemistry)

    1994-07-01

    Transport phenomena of aniline through Na[sup +]-, K[sup +]-, and Cs[sup +]-form of a perfluorosulfonate ion-exchange membrane, Nafion 117, under a flow of dc current, electrotransportation, were investigated. In each form, an increase in transport number of anilinium cation was observed in the current density range from 0.3 to 1.3 mA cm[sup [minus]2]. The transport number of the anilinium cation in Cs[sup +]-form was larger than that expected from the concentration and diffusion coefficient of the anilinium cation in Cs[sup +]-form Nafion. These aniline transport phenomena may be attributable to a structural change of Nafion or a decrease in hydrophobic interaction between the anilinium cation and Nafion caused by the flow of dc current.

  11. Electrodialysis-ion exchange for the separation of dissolved salts

    SciTech Connect

    Baroch, C.J.; Grant, P.J.

    1995-10-01

    The Department of Energy generates and stores a significant quantity of low level, high level, and mixed wastes. As some of the DOE facilities are decontaminated and decommissioned, additional and possibly different forms of wastes will be generated. A significant portion of these wastes are aqueous streams containing acids, bases, and salts, or are wet solids containing inorganic salts. Some of these wastes are quite dilute solutions, whereas others contain large quantities of nitrates either in the form of dissolved salts or acids. Many of the wastes are also contaminated with heavy metals, radioactive products, or organics. Some of these wastes are in storage because a satisfactory treatment and disposal processes have not been developed. There is considerable interest in developing processes that remove or destroy the nitrate wastes. Electrodialysis-Ion Exchange (EDIX) is a possible process that should be more cost effective in treating aqueous waste steams. This report describes the EDIX process.

  12. Extraction and ion-exchange behavior of mendelevium (II)

    SciTech Connect

    Guseva, L.I.; Tikhomirova, G.S.; Buklanov, G.V.; Pkhar, Z.Z.; Lebedev, I.A.; Katargin, N.V.; Myasoedov, B.F.

    1988-09-01

    Medelevium-256 was obtained via multinucleon transfer reactions upon irradiation of /sup 249/Bk by /sup 22/Ne ions from the extracted beam of a U-300 cyclotron. In order to extract mendelevium and separate it from the products of nuclear reactions, an express ion-exchange method using one column with cationite and zinc amalgam in a solution of 1 mole/liter HCl as the eluent was developed. It was shown that under these conditions mendelevium is reduced and washes out as an alkaline earth element. On the basis of the location of the peaks of the elution curves of Sr/sup 2+/, Eu/sup 2+/, and Md/sup 2+/, the value of the ionic radium of Md/sup 2+/ is estimated and is used to estimate the heat of hydration.

  13. Using ion exchange chromatography to purify a recombinantly expressed protein.

    PubMed

    Duong-Ly, Krisna C; Gabelli, Sandra B

    2014-01-01

    Ion exchange chromatography (IEX) separates molecules by their surface charge, a property that can vary vastly between different proteins. There are two types of IEX, cation exhange and anion exchange chromatography. The protocol that follows was designed by the authors for anion exchange chromatography of a recombinantly expressed protein having a pI of 4.9 and containing two cysteine residues and one tryptophan residue, using an FPLC system. Prior to anion exchange, the protein had been salted out using ammonium sulfate precipitation and partially purified via hydrophobic interaction chromatography (see Salting out of proteins using ammonium sulfate precipitation and Use and Application of Hydrophobic Interaction Chromatography for Protein Purification). Slight modifications to this protocol may be made to accommodate both the protein of interest and the availability of equipment. PMID:24674065

  14. Increase of ionic conductivity in the microporous lithosilicate RUB-29 by Na-ion exchange processes

    NASA Astrophysics Data System (ADS)

    Park, S.-H.; Senyshyn, A.; Paulmann, C.

    2007-12-01

    The ionic conductivity in the zeolite-like lithosilicate RUB-29 (Cs 14Li 24[Li 18Si 72O 172]·14H 2O [S.-H. Park, J.B. Parise, H. Gies, H. Liu, C.P. Grey, B.H. Toby, J. Am. Chem. Soc. 122 (2000) 11023-11024]) increases via simple ion-exchange processes, in particular when Na cations replace a part of Cs + and Li + of the material. The resulting ionic conductivity value of 3.2×10 -3 S cm -1 at 885 K is about two orders higher than that for the original material [S.-H. Park, J.B. Parise, M.E. Franke, T. Seydel, C. Paulmann, Micropor. Mesopor. Mater., in print ( doi:10.1016/j.micromeso.2007.03.040 available online since April 19, 2007)]. The structural basis of a Na +-exchanged RUB-29 sample (Na-RUB-29) at 673 K could be elucidated by means of neutron powder diffraction. Rietveld refinements confirmed the replacement of Na + for both parts of Cs and Li cations, agreeing with idealized cell content, Na 8Cs 8Li 40Si 72O 172. As a result of the incorporation of Na + in large pores, the number of Li + vacancies in dense Li 2O-layers of the structure could increase. This can be one of the main reasons for the improved conductivity in Na-RUB-29. In addition, mobile Na cations may also contribute to the conductivity in Na-RUB-29 as continuous scattering length densities were found around the sites for Na in difference Fourier map.

  15. Ion-exchange chromatography by dicarboxyl cellulose gel.

    PubMed

    Kim, U J; Kuga, S

    2001-06-01

    A new column packing material for ion-exchange chromatography was prepared from cellulose gel by periodate oxidation followed by chlorite oxidation to form spatially paired carboxyl groups (dicarboxyl cellulose, DCC). The carboxyl group was quantitatively introduced to spherical cellulose gel by controlling the extent of oxidation. The DCC gels were examined for their ion-exchange activity for various amines at pH of 2.5-5.5. In this pH range, aromatic amines with acid dissociation constant (pKa) below 2.7 showed no interaction with DCC gels as expected from their lack of protonation. The amines with pKa greater than 3.3, both aromatic and aliphatic, showed strong interaction corresponding to the amount of carboxyl introduced to the gel. However, these amines showed anomalous dependence on pH of the mobile phase, showing a maximum in retention factor at around pH 4. This is in contrast with the nearly constant retention factor of these amines on conventional carboxylated cellulose packing at pH greater than 4.0. The maximum retention factor at pH 4 of DCC gel was 4-5-times greater than that of conventional gel having a similar amount of carboxyls. Since pKa of dicarboxyl groups ranges 3-5 as determined by acid-base titration, the pH giving maximum retention corresponds to the pH at which one of paired carboxyls is dissociated. Possible cause of this anomaly is presented in terms of dissociation state of dicarboxyl groups and its interaction with amines. PMID:11459309

  16. Enhanced DOC removal using anion and cation ion exchange resins.

    PubMed

    Arias-Paic, Miguel; Cawley, Kaelin M; Byg, Steve; Rosario-Ortiz, Fernando L

    2016-01-01

    Hardness and DOC removal in a single ion exchange unit operation allows for less infrastructure, is advantageous for process operation and depending on the water source, could enhance anion exchange resin removal of dissolved organic carbon (DOC). Simultaneous application of cationic (Plus) and anionic (MIEX) ion exchange resin in a single contact vessel was tested at pilot and bench scales, under multiple regeneration cycles. Hardness removal correlated with theoretical predictions; where measured hardness was between 88 and 98% of the predicted value. Comparing bench scale DOC removal of solely treating water with MIEX compared to Plus and MIEX treated water showed an enhanced DOC removal, where removal was increased from 0.5 to 1.25 mg/L for the simultaneous resin application compared to solely applying MIEX resin. A full scale MIEX treatment plant (14.5 MGD) reduced raw water DOC from 13.7 mg/L to 4.90 mg/L in the treated effluent at a bed volume (BV) treatment rate of 800, where a parallel operation of a simultaneous MIEX and Plus resin pilot (10 gpm) measured effluent DOC concentrations of no greater than 3.4 mg/L, even at bed volumes of treatment 37.5% greater than the full scale plant. MIEX effluent compared to simultaneous Plus and MIEX effluent resulted in differences in fluorescence intensity that correlated to decreases in DOC concentration. The simultaneous treatment of Plus and MIEX resin produced water with predominantly microbial character, indicating the enhanced DOC removal was principally due to increased removal of terrestrially derived organic matter. The addition of Plus resin to a process train with MIEX resin allows for one treatment process to remove both DOC and hardness, where a single brine waste stream can be sent to sewer at a full-scale plant, completely removing lime chemical addition and sludge waste disposal for precipitative softening processes. PMID:26624231

  17. Removal of THM precursors by coagulation or ion exchange.

    PubMed

    Bolto, Brian; Dixon, David; Eldridge, Rob; King, Simon

    2002-12-01

    The removal of natural organic matter (NOM) from drinking water supplies can be achieved by different processes, among them coagulation and adsorption. Synthetic waters made from concentrates of humic substances from reservoir and river waters were tested in the laboratory for ease of removAl of NOM by coagulation with cationic organic polymers and with alum, and by adsorption on anion exchangers. For polymers such as high molecular weight polydiallyldimethylammonium chloride (polyDADMAC) and cationic polyacrylamides of high charge, performance was nearly as effective as alum, with colour removals 86-100% of those obtained for alum. Ion exchange using the best commercially available resins designed for this purpose, a gel polystyrene and a macroporous acrylic resin, was more effective than alum treatment for two of the natural waters studied, but inferior for a third. The resins were overall superior to cationic polymers. The NOM was separated into four fractions based on hydrophobic and hydrophilic properties. Alum was not as effective as ion exchange for the elimination of individual ionic NOM fractions. It was better than cationic polymers for removal of humic and fulvic acids, although polyDADMAC was as good for one water. For the removal of charged compounds alum then polyDADMAC were the best performers for that water. Unequivocal evidence was obtained that coagulants remove material that is not adsorbed by resins, and vice versa. A combination of coagulation with a cationic polymer and adsorption by an anion exchanger removed essentially all of the NOM. The preference of the coagulants was for the larger, more hydrophobic molecules, and of resins for smaller highly charged hydrophilic molecules. Each fraction had trihalomethane formation potentials in the range 11-24 microg/mg, except for one water that was more reactive. Hence, the actual amount of each fraction in the original water becomes a crucial factor. PMID:12448555

  18. THREE-DIMENSIONAL THERMAL MODELING ANALYSIS OF CST MEDIA FOR THE SMALL ION EXCHANGE PROJECT

    SciTech Connect

    Lee, S.; King, W.

    2011-09-12

    The Small Column Ion Exchange (SCIX) project is designed to accelerate closure of High Level Waste (HLW) tanks at the Savannah River Site (SRS). The SRS tanks store HLW in three forms: sludge, saltcake, and supernate. An in-tank ion exchange process is being designed to treat supernate and dissolved saltcake waste. Through this process, radioactive cesium from the salt solution is adsorbed into Crystalline Silicotitanate (CST) ion exchange media packed within a flow-through column. A packed column loaded with radioactive cesium generates significant heat from radiolytic decay. The waste supernate solution within the ion exchange bed will boil around 120 C. Solution superheating above the boiling point within the column could lead to violent hazardous energy releases. System heating from loaded CST is also of concern in other process modules, such as the waste tank. Due to tank structural integrity concerns, the wall temperature limit for the SRS waste tanks is 100 C. The transfer of cesium-loaded CST to the tank could result in localized hot spots on the tank floor and walls which may exceed this limit. As a result, thermal modeling calculations have been conducted to predict the maximum temperatures achievable both in the column and in the waste tank. As specified in the associated Technical Task Plan, one objective of the present work was to compute temperature distributions within the ion exchange column module under accident scenarios including loss of salt solution flow through the bed and loss of coolant system flow. The column modeling domain and the scope of the calculations in this case were broadened relative to previous two-dimensional calculations to include vertical temperature distributions within the packed bed of ion exchange media as well as the upper column plenum region containing only fluid. The baseline design conditions and in-column modeling domain for the ion-exchange column module are shown in Figure 1. These evaluations assumed the maximum

  19. The effect of positioning cations on acidity and stability of the framework structure of Y zeolite.

    PubMed

    Deng, Changshun; Zhang, Junji; Dong, Lihui; Huang, Meina; Bin Li; Jin, Guangzhou; Gao, Junbin; Zhang, Feiyue; Fan, Minguang; Zhang, Luoming; Gong, Yanjun

    2016-01-01

    The investigation on the modification of NaY zeolite on LaHY and AEHY (AE refers Ca and Sr and the molar ratio of Ca and Sr is 1:1) zeolites was proformed by XRD, N2-physisorption (BET), XRF, XPS, NH3-TPD, Py-IR, hydrothermal stability, and catalytic cracking test. These results indicate that HY zeolite with ultra low content Na can be obtained from NaY zeolite through four exchange four calcination method. The positioning capability of La(3+) in sodalite cage is much better than that of AE(2+) and about 12 La(3+) can be well coordinated in sodalite cages of one unit cell of Y zeolite. Appropriate acid amount and strength favor the formation of propylene and La(3+) is more suitable for the catalytic cracking of cyclohexane than that of AE(2+). Our results not only elaborate the variation of the strong and weak acid sites as well as the Brönsted and Lewis acid sites with the change of exchanged ion content but also explore the influence of hydrothermal aging of LaHY and AEHY zeolites and find the optimum ion exchange content for the most reserved acid sites. At last, the coordination state and stabilization of ion exchanged Y zeolites were discussed in detail. PMID:26987306

  20. The effect of positioning cations on acidity and stability of the framework structure of Y zeolite

    NASA Astrophysics Data System (ADS)

    Deng, Changshun; Zhang, Junji; Dong, Lihui; Huang, Meina; Bin Li; Jin, Guangzhou; Gao, Junbin; Zhang, Feiyue; Fan, Minguang; Zhang, Luoming; Gong, Yanjun

    2016-03-01

    The investigation on the modification of NaY zeolite on LaHY and AEHY (AE refers Ca and Sr and the molar ratio of Ca and Sr is 1:1) zeolites was proformed by XRD, N2-physisorption (BET), XRF, XPS, NH3-TPD, Py-IR, hydrothermal stability, and catalytic cracking test. These results indicate that HY zeolite with ultra low content Na can be obtained from NaY zeolite through four exchange four calcination method. The positioning capability of La3+ in sodalite cage is much better than that of AE2+ and about 12 La3+ can be well coordinated in sodalite cages of one unit cell of Y zeolite. Appropriate acid amount and strength favor the formation of propylene and La3+ is more suitable for the catalytic cracking of cyclohexane than that of AE2+. Our results not only elaborate the variation of the strong and weak acid sites as well as the Brönsted and Lewis acid sites with the change of exchanged ion content but also explore the influence of hydrothermal aging of LaHY and AEHY zeolites and find the optimum ion exchange content for the most reserved acid sites. At last, the coordination state and stabilization of ion exchanged Y zeolites were discussed in detail.

  1. The effect of positioning cations on acidity and stability of the framework structure of Y zeolite

    PubMed Central

    Deng, Changshun; Zhang, Junji; Dong, Lihui; Huang, Meina; Bin Li; Jin, Guangzhou; Gao, Junbin; Zhang, Feiyue; Fan, Minguang; Zhang, Luoming; Gong, Yanjun

    2016-01-01

    The investigation on the modification of NaY zeolite on LaHY and AEHY (AE refers Ca and Sr and the molar ratio of Ca and Sr is 1:1) zeolites was proformed by XRD, N2-physisorption (BET), XRF, XPS, NH3-TPD, Py-IR, hydrothermal stability, and catalytic cracking test. These results indicate that HY zeolite with ultra low content Na can be obtained from NaY zeolite through four exchange four calcination method. The positioning capability of La3+ in sodalite cage is much better than that of AE2+ and about 12 La3+ can be well coordinated in sodalite cages of one unit cell of Y zeolite. Appropriate acid amount and strength favor the formation of propylene and La3+ is more suitable for the catalytic cracking of cyclohexane than that of AE2+. Our results not only elaborate the variation of the strong and weak acid sites as well as the Brönsted and Lewis acid sites with the change of exchanged ion content but also explore the influence of hydrothermal aging of LaHY and AEHY zeolites and find the optimum ion exchange content for the most reserved acid sites. At last, the coordination state and stabilization of ion exchanged Y zeolites were discussed in detail. PMID:26987306

  2. Formation of metallic nanostructures on the surface of ion- exchange glass by focused electron beam

    NASA Astrophysics Data System (ADS)

    Komissarenko, F. E.; Zhukov, M. V.; Mukhin, I. S.; Golubok, A. O.; Sidorov, A. I.

    2015-11-01

    This paper presents a new method for formation of metallic nanostructures on the surface of ion-exchange glass. The method is based on the interaction of a focused electron beam with ions in ion-exchange glass. In experiments nanostructures with different shapes were obtained, depending on the electrons irradiation conditions.

  3. REMOVAL OF URANIUM FROM DRINKING WATER BY ION EXCHANGE AND CHEMICAL CLARIFICATION

    EPA Science Inventory

    A pilot demonstration was conducted of ion exchange and chemical clarification equipment for removing uranium from drinking water. Four commercial-type ion exchange columns and a prefiltering and regeneration solution system were constructed along with a pilot-scale chemical clar...

  4. Ion exchange resins. (Latest citations from the EI Compendex*plus database). Published Search

    SciTech Connect

    1995-01-01

    The bibliography contains citations concerning preparation, properties, and applications of ion exchange resins. Applications include water and waste treatment, chemical recovery, separation, purification, catalysis, desalination, and ore treatment. Regeneration and disposal of ion exchange resins are also covered. (Contains 250 citations and includes a subject term index and title list.)

  5. Ion exchange resins. (Latest citations from the EI Compendex*plus database). Published Search

    SciTech Connect

    1996-01-01

    The bibliography contains citations concerning preparation, properties, and applications of ion exchange resins. Applications include water and waste treatment, chemical recovery, separation, purification, catalysis, desalination, and ore treatment. Regeneration and disposal of ion exchange resins are also covered. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  6. Ion Exchange Resins for Long-Term Spent Nuclear Fuel Storage

    SciTech Connect

    Rideaux, J.

    1999-03-08

    This paper will specifically address the use and life cycle of ion exchange resins as they relate to the SRS Spent Nuclear Fuel Storage Basins. This paper also chronicles the use of two types of ion exchange resins and their affect on basin water quality from the sixties until today.

  7. Intermediate-Scale Ion Exchange Removal of Cesium and Technetium from Hanford Tank 241-AN-102

    SciTech Connect

    King, W.D.

    2001-02-15

    Ion exchange tests have been completed at the Savannah River Technology Center for British Nuclear Fuels Limited, Inc. as part of the Hanford River Protection Project. Radioactive cesium and technetium (pertechnetate form only) were removed by ion exchange from a sample of Envelope C salt solution from Hanford Tank 241-AN-102 (sample volume: approximately 17 L at 4.8 M Na plus). The original sample was diluted and subjected to strontium/transuranics (Sr/TRU) precipitation and filtration processes before ion exchange processing was performed. Batch contact and column tests for the ion exchange removal of cesium and technetium were then completed on the Sr/TRU-decontaminated product. Previous ion exchange tests were conducted on a smaller portion (0.5 L) of the Tank 241-AN-102 supernate sample, which had been similarly pretreated, and the results were reported in a separate document.

  8. Intermediate-Scale Ion Exchange Removal of Cesium and Technetium from Hanford Tank 241-AN-102

    SciTech Connect

    King, W.D.

    2001-09-10

    Ion exchange tests have been completed at the Savannah River Technology Center for British Nuclear Fuels Limited, Inc. as part of the Hanford River Protection Project. Radioactive cesium and technetium (pertechnetate form only) were removed by ion exchange from a sample of Envelope C salt solution from Hanford Tank 241-AN-102 (sample volume: approximately 18 L at 4.8 M Na plus). The original sample was diluted and subjected to strontium/transuranics (Sr/TRU) precipitation and filtration processes before ion exchange processing was performed. Batch contact and column tests for the ion exchange removal of cesium and technetium were then completed on the Sr/TRU-decontaminated product. Previous ion exchange tests were conducted on a smaller portion (0.5 L) of the Tank 241-AN-102 supernate sample, which had been similarly pretreated, and the results were reported in a separate document.

  9. Ion-exchange selectivities of periderm and cuticular membranes toward alkali cations

    SciTech Connect

    Ersoz, M.; Duncan, H.J.

    1994-08-01

    The ion-exchange selectivities of lithium, sodium, potassium, and cesium on isolated potato periderm (Solanum tuberosum) and pear fruit cuticular membranes were investigated; the general order of preference both for cation selectivities and ion-exchange capacities was lithium > sodium > potassium > cesium. The potato periderm and pear fruit cuticular membranes exhibited a behavior typical of ion-exchange resins of the weak acid type. At constant pH 7, the ion-exchange capacities of periderm and cuticular membranes increased with hydrated ionic radius, and also with increasing pH and neutral salt concentration, and decreased with crystal ionic radius. Counterion selectivities also exhibited the same behavior. The ion-exchange properties are discussed in terms of the structure and function of potato periderm and pear fruit cuticular membranes.

  10. Ion Exchange Media for Reduction of Liquid Radwaste in Commercial Power Plants

    SciTech Connect

    Yarnell, P.A.; Tavares, A.

    2008-07-01

    Ion exchange resins currently make up as much as one-half of all radioactive waste generated by commercial nuclear power plants. A major challenge is reduction of the quantity of ion exchange media requiring disposal. Although the amount of spent ion exchange resins disposed has decreased year after year, a new urgency has arisen with the pending closure of a major disposal site in 2008. This paper explores whether ion exchange resins also can be used to potentially reduce radioactive liquid waste volumes and / or limit them to Class A wastes only. Source term reduction and minimization of manpower exposure to radioactivity are other important goals. Specialty ion exchange products may help to achieve source term reduction of certain radionuclides. Some established operations, data, and process concepts are presented to address these critical issues encountered in liquid radwaste management. (authors)