Sample records for ion exchange applications

  1. Analytical applications of ion exchangers

    CERN Document Server

    Inczédy, J


    Analytical Applications of Ion Exchangers presents the laboratory use of ion-exchange resins. This book discusses the development in the analytical application of ion exchangers. Organized into 10 chapters, this book begins with an overview of the history and significance of ion exchangers for technical purposes. This text then describes the properties of ion exchangers, which are large molecular water-insoluble polyelectrolytes having a cross-linked structure that contains ionic groups. Other chapters consider the theories concerning the operation of ion-exchange resins and investigate th

  2. Pharmaceutical Applications of Ion-Exchange Resins (United States)

    Elder, David


    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…

  3. Organic Ion Exchangers. Synthesis, Characterization and Applications

    Institute of Scientific and Technical Information of China (English)

    E. S. Dragan


    @@ 1Introduction Organic ion exchangers in beads form are the most widely utilized materials in the purification, concentration and separation processes of inorganic and organic ions in many fields of science and industry[1,2]. Some original contributions in the preparation and characterization of porous organic ion exchangers will be summarized first. The main types of synthetic ion exchangers were obtained by polymer-analogous reactions performed on porous styrene-divinylbenzene copolymers (S-DVB)[3,4] and porous acrylonitrile-DVB copolymers (AN-DVB) [5,6]. Porous S-DVB copolymers were used as substrate for the synthesis of weak and strong base anion exchangers by chloromethylation reaction followed by the reaction with secondary or tertiary amines.Different chloromethylation agents were employed. Weak base anion exchangers with tertiary or primary amine groups were prepared starting from AN-DVB copolymers by aminolyse-hydrolyse reaction with asymmetrical diamines or ethylenediamine (EDA), respectively. Strong base anion exchangers were obtained by quaternization reaction with alkyl halides of the tertiary amine groups. Chelating ion exchangers with iminodiacetic groups were prepared by the carboxymethylation reaction of the primary amine groups above mentioned and of those contained in a vinylamine-ethylacrylate-DVB copolymer, vinylamine units being generated by a Hofmann degradation reaction of the primary amide groups contained in the acrylamide-ethylacrylate-DVB copolymerp[7]. An amphoteric ion exchanger was prepared by the hydrolysis of the ester groups after the Hofmann degradation.

  4. Ion exchange membranes in seawater applications : processes and characteristics

    NARCIS (Netherlands)

    Galama, A.H.


    Officiële titel ENG: Ion exchange membranes in seawater applications. Processes and characteristics Officiële titel NL: Ionwisselende membranen in zeewatertoepassingen. Processen en eigenschappen Auteur: A.H.Galama Jaar: 2015 ISBN: 978-94-6257-225-6 Samenvatting Zeewaterontzouting stelt me

  5. Ion-Exchange Chromatography: Basic Principles and Application. (United States)

    Cummins, Philip M; Rochfort, Keith D; O'Connor, Brendan F


    Ion-Exchange Chromatography (IEC) allows for the separation of ionizable molecules on the basis of differences in charge properties. Its large sample-handling capacity, broad applicability (particularly to proteins and enzymes), moderate cost, powerful resolving ability, and ease of scale-up and automation have led to it becoming one of the most versatile and widely used of all liquid chromatography (LC) techniques. In this chapter, we review the basic principles of IEC, as well as the broader criteria for selecting IEC conditions. By way of further illustration, we outline basic laboratory protocols to partially purify a soluble serine peptidase from bovine whole brain tissue, covering crude tissue extract preparation through to partial purification of the target enzyme using anion-exchange chromatography. Protocols for assaying total protein and enzyme activity in both pre- and post-IEC fractions are also described.


    Energy Technology Data Exchange (ETDEWEB)



    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.

  7. Recent progress and applications of ion-exclusion/ion-exchange chromatography for simultaneous determination of inorganic anions and cations. (United States)

    Nakatani, Nobutake; Kozaki, Daisuke; Mori, Masanobu; Tanaka, Kazuhiko


    One of the ultimate goals of ion chromatography is to determine both anions and cations found in samples with a single chromatographic run. In the present article, recent progress in ion-exclusion/ion-exchange chromatography for the simultaneous determinations of inorganic anions and cations are reviewed. Firstly, the principle and the control for the simultaneous separation and detection of analyte ions using ion-exclusion/cation-exchange chromatography with a weakly acidic cation-exchange column are outlined. Then, advanced chromatographic techniques in terms of analytical time, selectively and sensitivity are summarized. As a related method, ion-exclusion/anion-exchange chromatography with an anion-exchange column could be used for the simultaneous determination of inorganic nitrogen species, such as ammonium, nitrite and nitrate ions. Their usefulness and applications to water-quality monitoring and related techniques are also described.

  8. Ion exchange equilibrium constants

    CERN Document Server

    Marcus, Y


    Ion Exchange Equilibrium Constants focuses on the test-compilation of equilibrium constants for ion exchange reactions. The book first underscores the scope of the compilation, equilibrium constants, symbols used, and arrangement of the table. The manuscript then presents the table of equilibrium constants, including polystyrene sulfonate cation exchanger, polyacrylate cation exchanger, polymethacrylate cation exchanger, polysterene phosphate cation exchanger, and zirconium phosphate cation exchanger. The text highlights zirconium oxide anion exchanger, zeolite type 13Y cation exchanger, and

  9. Ion-exchange chromatographic protein refolding

    NARCIS (Netherlands)

    Freydell, E.; Wielen, van der L.; Eppink, M.H.M.; Ottens, M.


    The application of ion-exchange (IEX) chromatography to protein refolding (IExR) has been successfully proven, as supported by various studies using different model proteins, ion-exchange media and flow configurations. Ion-exchange refolding offers a relatively high degree of process

  10. Ion-exchange chromatographic protein refolding

    NARCIS (Netherlands)

    Freydell, E.; Wielen, van der L.; Eppink, M.H.M.; Ottens, M.


    The application of ion-exchange (IEX) chromatography to protein refolding (IExR) has been successfully proven, as supported by various studies using different model proteins, ion-exchange media and flow configurations. Ion-exchange refolding offers a relatively high degree of process intensification

  11. Ion Exchange Equilibrium and Kinetic Properties of Polyacrylate Films and Applications to Chemical Analysis and Environmental Decontamination (United States)

    Tanner, Stephen P.


    One of the goals of the original proposal was to study how cross-linking affects the properties of an ion exchange material(IEM) developed at Lewis Research Center. However, prior to the start of this work, other workers at LERC investigated the effect of cross-linking on the properties of this material. Other than variation in the ion exchange capacity, the chemical characteristics were shown to be independent of the cross-linking agent, and the degree of cross-linking. New physical forms of the film were developed (film, supported film, various sizes of beads, and powder). All showed similar properties with respect to ion exchange equilibria but the kinetics of ion exchange depended on the surface area per unit mass; the powder form of the IEM exchanging much more rapidly than the other forms. The research performed under this grant was directed towards the application of the IEM to the analysis of metal ions at environmental concentrations.

  12. New ion exchange resin designs and regeneration procedures yield improved performance for various condensate polishing applications

    Energy Technology Data Exchange (ETDEWEB)

    Najmy, S.W. [Dow Chemical Co., Midland, MI (United States)


    Condensate polishing is an application with many different design and operational aspects. The past decade has brought new challenges for improved water quality with respect to both soluble and insoluble contaminants. Nonetheless, the endeavors to understand the compositional complexities of the ion exchange resin bead and the convoluted dynamics of ion exchange chemistry and chemical engineering mechanisms occurring within the mixed bed condensate polisher have brought new ideas and expectations for ion exchange resin in deep-bed condensate polishers than ever before. The new products and procedures presented here are a collaboration of a great deal of effort on the part of researchers, consultants, system engineers, station chemists, lab technicians and others. The studies discussed in this paper unequivocally demonstrate the merits of: 1. A specially designed cation resin to achieve greater than 95% insoluble iron removal efficiency, 2. A less-separable mixed resin for improved control of reactor water sulfate in BWR primary cycles, 3. Applying increased levels of regeneration chemicals and retrofitting the service vessels with re-mixing capability to improve the operation of deep-bed condensate polishers in PWR secondary cycles. (authors)

  13. Ion exchange phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Bourg, I.C.; Sposito, G.


    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).

  14. Application of the new thermodynamic approach to the description of superequivalent sorption by ion exchangers (United States)

    Khokhlova, O. N.


    Using the example of sorption systems with the participation of amino acids, it is shown that the novel thermodynamic approach to describing superequivalent sorption as a combination of ion exchange and nonexchangeable absorption allows us to adequately describe such equilibria. Results from calculating the activity coefficients of components of a sorbent phase and the thermodynamic constants of ion exchange equilibrium and the superequivalent absorption of phenylalanine by AV-17-8 anion exchange resin are presented.

  15. Systematic generation of buffer systems for pH gradient ion exchange chromatography and their application. (United States)

    Kröner, Frieder; Hubbuch, Jürgen


    pH gradient protein separations are widely used techniques in the field of protein analytics, of which isoelectric focusing is the most well known application. The chromatographic variant, based on the formation of pH gradients in ion exchange columns is only rarely applied due to the difficulties to form controllable, linear pH gradients over a broad pH range. This work describes a method for the systematic generation of buffer compositions with linear titration curves, resulting in well controllable pH gradients. To generate buffer compositions with linear titration curves an in silico method was successfully developed. With this tool, buffer compositions for pH gradient ion exchange chromatography with pH ranges spanning up to 7.5 pH units were established and successfully validated. Subsequently, the buffer systems were used to characterize the elution behavior of 22 different model proteins in cation and anion exchange pH gradient chromatography. The results of both chromatographic modes as well as isoelectric focusing were compared to describe differences in between the methods.

  16. Evaluation of Alternate Ion Exchange Designs for CST Non-Elutable Ion Exchange Process

    Energy Technology Data Exchange (ETDEWEB)

    Yen, S.N.; Pike, J.A.; Jacobs, R.A.; Poirier, M.R.; Sahawneh, B.M.; Leugemors, R.K.


    A study of alternative column designs was initiated in late 2000 to explore ion exchange column design concepts outside of the baseline case. The study, which is discussed in detail in the report, has identified two promising commercially proven ion-exchange column designs as candidates to be developed further for application to CST ion-exchange technology.

  17. Mass and Heat Transfer in Ion-Exchange Membranes Applicable to Solid Polymer Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Otteroey, M.


    In this doctoral thesis, an improved emf method for determination of transference numbers of two counter ions in ion-exchange membranes is presented. Transference numbers were obtained as a continuous function of the composition. The method avoids problems with diffusion by using a stack of membranes. Water transference coefficients in ion-exchange membranes is discussed and reversible and irreversible water transfer is studied by emf methods. Efforts were made to get data relevant to the solid polymer fuel cell. The results support the findings of other researchers that the reversible water transfer is lower than earlier predicted. A chapter on the conductivity of ion-exchange membranes establishes a method to separate the very thin liquid layers surrounding the membranes in a stack. Using the method it was found that the conductivity is obtained with high accuracy and that the liquid layer in a membrane stack can contribute significantly to the total measured resistance. A four point impedance method was tested to measure the conductivity of membranes under fuel cell conditions. Finally, there is a discussion of reversible heat effects and heat transfer in ion-exchange membranes. 155 refs., 45 figs., 13 tabs.

  18. Mass and Heat Transfer in Ion-Exchange Membranes Applicable to Solid Polymer Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Otteroey, M.


    In this doctoral thesis, an improved emf method for determination of transference numbers of two counter ions in ion-exchange membranes is presented. Transference numbers were obtained as a continuous function of the composition. The method avoids problems with diffusion by using a stack of membranes. Water transference coefficients in ion-exchange membranes is discussed and reversible and irreversible water transfer is studied by emf methods. Efforts were made to get data relevant to the solid polymer fuel cell. The results support the findings of other researchers that the reversible water transfer is lower than earlier predicted. A chapter on the conductivity of ion-exchange membranes establishes a method to separate the very thin liquid layers surrounding the membranes in a stack. Using the method it was found that the conductivity is obtained with high accuracy and that the liquid layer in a membrane stack can contribute significantly to the total measured resistance. A four point impedance method was tested to measure the conductivity of membranes under fuel cell conditions. Finally, there is a discussion of reversible heat effects and heat transfer in ion-exchange membranes. 155 refs., 45 figs., 13 tabs.

  19. Macroreticular chelating ion-exchangers. (United States)

    Hirsch, R F; E Gancher, R; Russo, F R


    Two macroreticular chelating ion-exchangers have been prepared and characterized. One contains the iminodiacetate group and the second contains the arsonate group as the ion-exchanging site. The macroreticular resins show selectivities among metal ions similar to those of the commercially available naicroreticular chelating resins. Chromatographie separations on the new resins are rapid and sharp.

  20. Electrically switched ion exchange

    Energy Technology Data Exchange (ETDEWEB)

    Lilga, M.A. [Pacific Northwest National Lab., Richland, WA (United States); Schwartz, D.T.; Genders, D.


    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.

  1. Development and properties of crystalline silicotitanate (CST) ion exchangers for radioactive waste applications

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J.E.; Brown, N.E.


    Crystalline silicotitanates (CSTs) are a new class of ion exchangers that were jointly invented by researchers at Sandia National Laboratories and Texas A&M University. One particular CST, known as TAM-5, is remarkable for its ability to separate parts-per-million concentrations of cesium from highly alkaline solutions (pH> 14) containing high sodium concentrations (>5M). It is also highly effective for removing cesium from neutral and acidic solutions, and for removing strontium from basic and neutral solutions. Cesium isotopes are fission products that account for a large portion of the radioactivity in waste streams generated during weapons material production. Tests performed at numerous locations with early lab-scale TAM-5 samples established the material as a leading candidate for treating radioactive waste volumes such as those found at the Hanford site in Washington. Thus Sandia developed a Cooperative Research and Development Agreement (CRADA) partnership with UOP, a world leader in developing, commercializing, and supplying adsorbents and associated process technology to commercialize and further develop the material. CSTs are now commercially available from UOP in a powder (UOP IONSIV{reg_sign} IE-910 ion exchanger) and granular form suitable for column ion exchange operations (UOP IONSIV{reg_sign} IE-911 ion exchanger). These materials exhibit a high capacity for cesium in a wide variety of solutions of interest to the Department of Energy, and they are chemically, thermally, and radiation stable. They have performed well in tests at numerous sites with actual radioactive waste solutions, and are being demonstrated in the 100,000 liter Cesium Removal Demonstration taking place at Oak Ridge National Laboratory with Melton Valley Storage Tank waste. It has been estimated that applying CSTs to the Hanford cleanup alone will result in a savings of more than $300 million over baseline technologies.

  2. Thermal potential of ion-exchange membranes and its application to thermoelectric power generation


    Jokinen, Miikka; Manzanares Andreu, Jose; Kontturi, Kyösti; Murtomäki, Lasse


    The low efficiency and high price of thermoelectric semiconductors has generated interest in unconventional forms of thermoelectric materials. In this article, ionic thermoelectricity has been studied with commercial ion-exchange membranes for different aqueous 1:1 electrolytes. The theory of thermal membrane potential has been derived taking into account the ionic heats of transport, the non-isothermal Donnan potentials, the temperature polarization, and the thermally-induced concentration p...

  3. Ion-Exchange Interdiffusion Model with Potential Application to Long-Term Nuclear Waste Glass Performance

    Energy Technology Data Exchange (ETDEWEB)

    Neeway, James J.; Kerisit, Sebastien N.; Liu, Jia; Zhang, Jiandong; Zhu, Zihua; Riley, Brian J.; Ryan, Joseph V.


    Abstract: Ion exchange is an integral mechanism influencing the corrosion of glasses. Due to the formation of alteration layers in aqueous conditions, it is difficult to conclusively deconvolute the process of ion exchange from other processes, principally dissolution of the glass matrix. Therefore, we have developed a method to isolate alkali diffusion that involves contacting glass coupons with a solution of 6LiCl dissolved in functionally inert dimethyl sulfoxide. We employ the method at temperatures ranging from 25 to 150 °C with various glass formulations. Glass compositions include simulant nuclear waste glasses, such as SON68 and the international simple glass (ISG), glasses in which the nature of the alkali element was varied, and glasses that contained more than one alkali element. An interdiffusion model based on Fick’s second law was developed and applied to all experiments to extract diffusion coefficients. The model expands established models of interdiffusion to the case where multiple types of alkali sites are present in the glass. Activation energies for alkali ion exchange were calculated and the results are in agreement with those obtained in glass strengthening experiments but are nearly five times higher than values reported for diffusion-controlled processes in nuclear waste glass corrosion experiments. A discussion of the root causes for this apparent discrepancy is provided. The interdiffusion model derived from laboratory experiments is expected to be useful for modeling glass corrosion in a geological repository when the silicon concentration is high.

  4. Reversible ion exchange and structural stability of garnet-type Nb-doped Li7La3Zr2O12 in water for applications in lithium batteries (United States)

    Liu, Cai; Rui, Kun; Shen, Chen; Badding, Michael E.; Zhang, Gaoxiao; Wen, Zhaoyin


    H+/Li+ ion exchange and structural stability of the high ionic conductivity Nb-doped Zr-garnet Li6.75La3Nb0.25Zr1.75O12 (LLNZO) are investigated in this study. Relationships between ion exchange and Li-population per unit cell, which are necessary to establish the practical framework of garnet electrolytes, are deduced for garnet oxides within ion-exchange process. H+/Li+ ion exchange of cubic LLNZO powder is performed continuously in distilled water and products with various exchange levels are obtained via this simple method. FTIR spectra show the evolution of H-O bonding through the ion-exchange process. A maximum of 74.8% exchange of Li+ by H+ was found, consistent with a preferential replacement of octahedrally coordinated Li. The cubic garnet phase is maintained throughout all levels of proton exchange observed. The formation of garnet-type solid solution of Li6.75-xHxLa3Nb0.25Zr1.75O12 is indicated by well-resolved lattice fringes as well as the linear evolution of crystal lattice parameters with the ion exchange level. The reverse ion exchange of H+ by Li+ is successfully achieved in Li+ containing aqueous solutions, demonstrating its high structural stability and good compatibility for promising applications in lithium batteries.

  5. Long-term stable silver subsurface ion-exchanged glasses for SERS applications. (United States)

    Simo, Anne; Joseph, Virginia; Fenger, Robert; Kneipp, Janina; Rademann, Klaus


    We report on the formation of silver subsurface ion-exchanged metal oxide (silver SIMO) glasses and their surface-enhanced Raman scattering (SERS) activity. The samples were prepared by a combined thermal and chemical three-step methodology and characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM), environmental electron scanning microscopy (ESEM), and UV/Vis spectroscopy. This unique method provides SERS substrates with protection against contamination and strong, reliable and reproducible SERS enhancement. The Raman enhancement factors of the long-term stable SIMO glasses were estimated to approximately 10(7).

  6. Radiation induced grafting of tetrafluoroethylene on Nafion Films for ion exchange membrane application

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    Geraldes, Adriana Napoleao; Silva, Dionisio Furtunato da; Ferreto, Helio Fernando Rodrigues; Souza, Camila Pinheiro; Parra, Duclerc Fernandes; Lugao, Ademar Benevolo [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)


    Grafting of TFE nanocomposites onto Nafion was studied for synthesis of ion exchange membranes. Radiation-induced grafting of TFE gas onto Nafion films was investigated after simultaneous irradiation using a {sup 60}Co source. The thermal degradation of polytetrafluoroethylene (PTFE) waste has been used for production of TFE. Nafion films were irradiated at 15 kGy dose at room temperature and chemical changes were monitored after contact with TFE gas for grafting. The modified films were evaluated by differential scanning calorimetry analysis (DSC), thermogravimetric analysis (TG), scanning electron microscopy (SEM) and X-ray diffraction (XRD). Characterization by XRD suggests crystallinity changes after TFE grafting. The ion exchange capacity (IEC) of membranes was determined by acid-base titration and the values for modified films were achieved similar to Nafion pristine films. DSC measurements revealed a displacement in the endothermic peaks and it was probably associated with the TFE graft. The graft forces the Nafion polymer chains to re-organize themselves and form a more cross-linked structure within the clusters. (author)

  7. Electrically Switched Cesium Ion Exchange

    Energy Technology Data Exchange (ETDEWEB)

    JPH Sukamto; ML Lilga; RK Orth


    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.

  8. Application of tracer packet technique for multielemental uptake studies on the inorganic ion exchanger zirconium vanadate

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Kamalika; Basu, S.; Ramaswami, A.; Lahiri, Susanta E-mail:


    The conception of tracer packet was first started with the irradiation of a thick cobalt target with {sup 16}O, {sup 7}Li and {sup 12}C beams, consecutively. This produced carrier-free radiotracers of Mn, Cu, Zn, Ga, Ge, As and Se. These elements are adjacent members in the periodic table and are of nutritional importance. Another 'tracer packet', which was subsequently designed, was of heavy and toxic metals. A gold target irradiated with medium energy {sup 7}Li and {sup 12}C produced {sup 197}Hg, {sup 200}Tl, {sup 200}Pb, {sup 204}Bi, {sup 204}Po. The uptake of these elements has been studied using two different ion exchangers, one of inorganic origin and the other of chelating type.

  9. Transport, charge exchange and loss of energetic heavy ions in the earth's radiation belts - Applicability and limitations of theory (United States)

    Spjeldvik, W. N.


    Computer simulations of processes which control the relative abundances of ions in the trapping regions of geospace are compared with observations from discriminating ion detectors. Energy losses due to Coulomb collisions between ions and exospheric neutrals are considered, along with charge exchange losses and internal charge exchanges. The time evolution of energetic ion fluxes of equatorially mirroring ions under radial diffusion is modelled to include geomagnetic and geoelectric fluctutations. Limits to the validity of diffusion transport theory are discussed, and the simulation is noted to contain provisions for six ionic charge states and the source effect on the radiation belt oxygen ion distributions. Comparisons are made with ion flux data gathered on Explorer 45 and ISEE-1 spacecraft and results indicate that internal charge exchanges cause the radiation belt ion charge state to be independent of source charge rate characteristics, and relative charge state distribution is independent of the radially diffusive transport rate below the charge state redistribution zone.

  10. Inorganic ion exchangers for nuclear waste remediation

    Energy Technology Data Exchange (ETDEWEB)

    Clearfield, A.; Bortun, A.; Bortun, L.; Behrens, E. [Texas A& M Univ., College Station, TX (United States)


    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.

  11. Ionic Polymer-Metal Composites (IPMCs) with Various Ion Exchange Membranes and Their Potential Use in IPMC Applications (United States)

    Park, Jiyeon

    Ionic polymer metal composites (IPMCs) have been widely studied and drawn great attention for the last several years in robotics and medical fields due to their great potential as actuators, artificial muscles, and more. Each part of an IPMC is important, but the role of ionic exchange membrane should be emphasized because, after all, it is where ions migrate when voltage is applied to produce motion. So far, most researches have been done on IPMCs made with commercially available ionic exchange membranes such as Nafion or Flemion. In this thesis, the research is mainly focused on fabricating IPMCs with several other ionic exchange membranes that are commercially available and characterization of optical, physical, and electromechanical properties of those IPMCs. Five different ion exchange membranes of DuPont (N115), Golden Energy Fuel Cells Inc (GEFC-700)., fuMA Tech (F-14100), Membranes International Inc. (CMI-7000S) and University of Nevada Las Vegas (19-PSU-S1) are the chosen membranes. N115, GEFC-700, and F-14100 have the same structure. CMI-7000S is a reinforced membrane by mixing fibers with the ion exchange membrane. 19-PSU-S1 is a membrane that was made at UNLV for fuel cell application. The physical properties of the ionic exchange membranes were studied by examining water uptake. The thermal analysis also was carried out with Differential Scanning Calorimetry (DSC). Water uptake and ion exchange capacities were measured to confirm the physical properties of IPMCs. The structure of the IPMCs was observed under Scanning Electron Microscopy (SEM). The structures of fabricated IPMCs were observed by SEM and DSC. Capacitance was also measured by drawing impedance curves. Young's modulus (E) was measured to determine the stiffness of each IPMC. Lastly, bending actuation test was carried out to observe the actual performance of each IPMC in water. The water uptake of all IPMCs is less than 40%. 19-PSU-S1 absorbed the most water (35.2 %) and CMI-7000S absorbed

  12. Fabrication of electrospun polyacrylonitrile ion-exchange membranes for application in lysozyme adsorption

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    Full Text Available Ion exchange (IEX chromatography is commonly used in separation and purification systems. However, micropore blockage within its resin structure can easily lead to a reduction in the effectiveness of purification. To tackle this problem, we adopted the concept of membrane separation by combining electrospinning techniques with rapid alkaline hydrolysis to prepare a weak acid IEX nanofibrous membrane (AEA-COOH, consisting of polyethyleneterephthalate (PET meltblown fabric as a supporting layer, with upper and lower IEX layers consisting of polyacrylonitrile (PAN nanofibrous membranes. To determine the characteristics of the AEA-COOH membrane, we used the commercial product Sartobind© C IEX membrane as the standard of comparison. Results showed that the base weight and thickness of AEACOOH were 33 and 64%, relative to Sartobind© C membrane. The thermo-degradable temperature of AEA-COOH membrane (320°C was far higher than that of Sartobind© C (115°C, indicating high thermal stability. Finally, comparisons between the lysozyme adsorption rates and capacity of various IEX membranes confirmed that AEA-COOH was lighter, thinner, faster, possessing higher protein adsorption efficiency than Sartobind© C membrane.

  13. Application of mixture design to optimize cementation of simulated spent radioactive ion exchange resins

    Institute of Scientific and Technical Information of China (English)

    GAN Xue-Ying; BAO Liang-Jin; LIN Mei-Qiong; James D.NAVRATIL


    The aim of this study was to assess the usefulness of a mixture design for spent resin immobilization in cement as well as to examine the cement-slag-ash system for spent resin solidification. Eighteen distinct combinations, consisting of Portland cement, blast furnace slag, fly ash, organic ion exchange resins and water, were selected by a mixture design computer procedure to compose representative experiment points. The measured properties of solidified forms resulting from the combinations included 28-day compressive strength, 42-day immersion strength,42-day immersion weight and slump. These data were fit to a mathematic model with the aid of Scheffe quadratic polynomial, and the effects of each ingredient on the measured properties were identified through an analysis of the response trace plots and contour plots. Utilization of an optimality function singled out an optimal combination comprising water=0.16(wt/wt), slag=0.21, ash=0.10, cement=0.27 and resin=0.26 from which the resulting response was 1 1MPa for the 28-day strength, 110mm for the slump and 5.4% for the 42-day increase in strength.

  14. Characterization of Cr ion exchange with hydrotalcite. (United States)

    Terry, Patricia A


    Experiments were performed to characterize the removal of chromium from water with uncalcined hydrotalcite, a clay mineral ion exchange media. The process was characterized as a function of pH, temperature, contact time, and both Cr and hydrotalcite concentrations. A Freundlich isotherm, used to describe adsorption equilibria, was used as a model and Freundlich constants were determined. The kinetics of the ion exchange reaction were also modeled using a pseudo-first order reaction rate. Finally, an equilibrium stage process was modeled with sequential batch separations to determine if hydrotalcite ion exchange could reduce aqueous Cr levels to below the EPA limit of 0.1mgl(-1). It was shown that the process is highly pH dependent, only yielding significant removals at pH levels between 2.0 and 2.1. While hydrotalcite concentration, Cr concentration, and time did effect the ion exchange, temperature was not found to be a factor. Under optimal conditions, maximum removals of greater than 95% were achieved. Finally, sequential batch tests performed on initial Cr solutions ranging from 5mgl(-1) to 40mgl(-1), demonstrated that the water could be purified to a level that was not statistically different than the EPA limit, thus demonstrating the applicability of hydrotalcite ion exchange.

  15. Ion Exchange and Liquid Column Chromatography. (United States)

    Walton, Harold F.


    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)

  16. Electrically controlled cesium ion exchange

    Energy Technology Data Exchange (ETDEWEB)

    Lilga, M. [Pacific Northwest Lab., Richland, WA (United States)


    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.

  17. Ion-exchange chromatography: basic principles and application to the partial purification of soluble mammalian prolyl oligopeptidase. (United States)

    Cummins, Philip M; Dowling, Oonagh; O'Connor, Brendan F


    Ion-exchange chromatography (IEC) allows for the separation of ionizable molecules on the basis of differences in charge properties. Its large sample-handling capacity, broad applicability (particularly to proteins and enzymes), moderate cost, powerful resolving ability, and ease of scale-up and automation have led to it becoming one of the most versatile and widely used of all liquid chromatography (LC) techniques. In this chapter, we review the basic principles of IEC, as well as the broader criteria for selecting IEC conditions. By way of further illustration, we outline protocols necessary to partially purify a serine peptidase from bovine whole brain cytosolic fraction, covering crude tissue extract preparation through to partial purification of the target enzyme using anion-exchange chromatography. Protocols for assaying total protein and enzyme activity in both pre- and post-IEC fractions are also described. The target serine peptidase, prolyl oligopeptidase (POP, EC3.4.21.26), is an 80-kDa enzyme with endopeptidase activity towards peptide substrates of ≤30 amino acids. POP is a ubiquitous post-proline cleaving enzyme with particularly high expression levels in the mammalian brain, where it participates in the metabolism of neuroactive peptides and peptide-like hormones (e.g. thyroliberin, gonadotropin-releasing hormone).

  18. Evidence of ammonium ion-exchange properties of natural bentonite and application to ammonium detection. (United States)

    Zazoua, A; Kazane, I; Khedimallah, N; Dernane, C; Errachid, A; Jaffrezic-Renault, N


    Ammonium exchange with hybrid PVC-bentonite (mineral montmorillonite clay) thin film was revealed using FTIR spectroscopy, EDX, cyclic voltammetry and electrochemical impedance spectroscopy. The effect of ammonium exchange on the charge transfer resistance of PVC-bentonite hybrid thin film was attributed to a modification of the intersheet distance and hydration of bentonite crystals. The obtained impedimetric ammonium sensor shows a linear range of detection from 10(-4)M to 1M and a detection limit around 10(-6)M. © 2013.

  19. Synthesis, characterization and application of ion exchange resin as a slow-release fertilizer for wheat cultivation in space (United States)

    Li, Bowei; Dong, Chen; Chu, Zhengpei; Zhang, Weizhe; Wang, Minjuan; Liu, Hong; Xie, Beizhen


    In addition to the bio-regenerative air revitalization, water recycling and waste management systems and their associated challenges, enhancing the crop yield with less fertilizer input for sustainable food production in space is also a challenge that needs to be overcome. The purpose of this study is to investigate the feasibility of applying ion exchange resin as a slow-release fertilizer for wheat cultivation in space. Strong-acid cationic exchange resins and weak-base anion exchange resins soaked in 1X, 5X, 10X and 15X Hoagland nutrient solutions, respectively, were used as fertilizers in clinoptilolite to cultivate wheat plants, and the morphological and physiological characteristics of the wheat plants were studied and compared with that of the wheat planted in vermiculite and nutrient solutions. The results showed that more ions were attached on the surface of the ion exchange resins as the solution concentration increased. After 14 days, the fresh weight of wheat planted in the ion exchange resin-clinoptilolite (IER-clinoptilolite) treated with 10X and 15X solutions were 190% and 192% higher than that of wheat planted in nutrient solution with the same concentration. Chlorophyll content of wheat plants cultivated in the two kinds of solid medium is significantly higher than that of liquid cultivation. The lowest peroxidase (POD) activity and malondialdehyde (MDA) contents of wheat plants cultivated in the IER-clinoptilolite appeared on the 14th day. According to all the experimental data, it's promising to produce slow-release nutrient fertilizer by using strong-acid cationic exchange resins and weak-base anion exchange resins for wheat cultivation in space.

  20. Effects of ionizing radiation on modern ion exchange materials

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  1. Ion exchange model for α phase proton exchange waveguide in LiNbO3

    DEFF Research Database (Denmark)

    Veng, Torben Erik; Skettrup, Torben


    An H+/Li+ exchange model is found to be applicable to describe the diffusion of protons when optical waveguides are formed in LiNbO3 by proton exchange methods where the proton doped crystal structure stays in the pure α phase. The H + and Li+ self-diffusion coefficients in the ion exchange model...

  2. Electrostatic model for protein adsorption in ion-exchange chromatography and application to monoclonal antibodies, lysozyme and chymotrypsinogen A. (United States)

    Guélat, Bertrand; Ströhlein, Guido; Lattuada, Marco; Morbidelli, Massimo


    A model for the adsorption equilibrium of proteins in ion-exchange chromatography explicitly accounting for the effect of pH and salt concentration in the limit of highly diluted systems was developed. It is based on the use of DLVO theory to estimate the electrostatic interactions between the charged surface of the ion-exchanger and the proteins. The corresponding charge distributions were evaluated as a function of pH and salt concentration using a molecular approach. The model was verified for the adsorption equilibrium of lysozyme, chymotrypsinogen A and four industrial monoclonal antibodies on two strong cation-exchangers. The adsorption equilibrium constants of these proteins were determined experimentally at various pH values and salt concentrations and the model was fitted with a good agreement using three adjustable parameters for each protein in the whole range of experimental conditions. Despite the simplifications of the model regarding the geometry of the protein-ion-exchanger system, the physical meaning of the parameters was retained.

  3. A nano-silver composite based on the ion-exchange response for the intelligent antibacterial applications. (United States)

    Wang, Chan; Huang, Xiaobo; Deng, Weilin; Chang, Chengliang; Hang, Ruiqiang; Tang, Bin


    As a kind of antimicrobial agent, nano-silver composites have attracted a great deal of interest in biomedical applications. However, the typical loadings of silver nanoparticles (AgNPs) in such composites could result in dose-related cytotoxicity. In this study, a nano-silver composite leading to antimicrobial activity without cytotoxicity was fabricated by loading AgNPs into a dried alginate hydrogel. The biological performance of this composite mainly depended on the release of AgNPs, which needed to be triggered by the ion-exchange response and was further influenced by the loadings of AgNPs in the composite. The antimicrobial activity against E. coli and S. aureus demonstrated that the released silver no less than 678 ppb in the medium caused a reduction of 7log10CFU/mL (100%) bacteria. Significantly, the dose (~1.10×10(3) ppb) of released silver was not toxic and allowed attachment, and growth of MC3T3-E1 pre-osteoblast cells. These results supported that the composite was compatible with in vitro mammalian cells yet exhibited antimicrobial activity by carefully designing the loadings of AgNPs within the alginate. Thus, it indicated that the performance of this composite might permit management of bacterial infection in wound beds without impairment of wound healing.

  4. Novel silica-based ion exchange resin

    Energy Technology Data Exchange (ETDEWEB)



    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.

  5. Using Ion Exchange Chromatography to Separate and Quantify Complex Ions (United States)

    Johnson, Brian J.


    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"…

  6. Using Ion Exchange Chromatography to Separate and Quantify Complex Ions (United States)

    Johnson, Brian J.


    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"…

  7. Ion-exchanged glass waveguide technology: a review (United States)

    Tervonen, Ari; West, Brian R.; Honkanen, Seppo


    We review the history and current status of ion exchanged glass waveguide technology. The background of ion exchange in glass and key developments in the first years of research are briefly described. An overview of fabrication, characterization and modeling of waveguides is given and the most important waveguide devices and their applications are discussed. Ion exchanged waveguide technology has served as an available platform for studies of general waveguide properties, integrated optics structures and devices, as well as applications. It is also a commercial fabrication technology for both passive and active wave-guide components.

  8. Ion Exchange Formation via Sulfonated Bicomponent Nonwovens (United States)

    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.

  9. [Ion specificity during ion exchange equilibrium in natural clinoptilolite]. (United States)

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


    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.

  10. Regulation of protein multipoint adsorption on ion-exchange adsorbent and its application to the purification of macromolecules. (United States)

    Huang, Yongdong; Bi, Jingxiu; Zhao, Lan; Ma, Guanghui; Su, Zhiguo


    Ion-exchange chromatography (IEC) using commercial ionic absorbents is a widely used technique for protein purification. Protein adsorption onto ion-exchange adsorbents often involves a multipoint adsorption. In IEC of multimeric proteins or "soft" proteins, the intense multipoint binding would make the further desorption difficult, even lead to the destruction of protein structure and the loss of its biological activity. In this paper, DEAE Sepharose FF adsorbents with controllable ligand densities from 0.020 to 0.183 mmol/ml were synthesized, and then the effect of ligand density on the static ion-exchange adsorption of bovine serum albumin (BSA) onto DEAE Sepharose FF was studied by batch adsorption technique. Steric mass-action (SMA) model was employed to analyze the static adsorption behavior. The results showed that the SMA model parameters, equilibrium constant (K(a)), characteristic number of binding sites (υ) and steric factor (σ), increased gradually with ligand density. Thus, it was feasible to regulate BSA multipoint adsorption by modulating the ligand density of ion-exchange adsorbent. Furthermore, IEC of hepatitis B surface antigen (HBsAg) using DEAE Sepharose FF adsorbents with different ligand densities was carried out, and the activity recovery of HBsAg was improved from 42% to 67% when the ligand density was decreased from 0.183 to 0.020 mmol/ml. Taking the activity recovery of HBsAg, the purification factor and the binding capacity into account, DEAE Sepharose FF with a ligand density of 0.041 mmol/ml was most effective for the purification of HBsAg. Such a strategy may also be beneficial for the purification of macromolecules and multimeric proteins.

  11. Oxidation of cyclohexane catalyzed by metal-ion-exchanged zeolites. (United States)

    Sökmen, Ilkay; Sevin, Fatma


    The ion-exchange rates and capacities of the zeolite NaY for the Cu(II), Co(II), and Pb(II) metal ions were investigated. Ion-exchange equilibria were achieved in approximately 72 h for all the metal ions. The maximum ion exchange of metal ions into the zeolite was found to be 120 mg Pb(II), 110 mg Cu(II), and 100 mg Co(II) per gram of zeolite NaY. It is observed that the exchange capacity of a zeolite varies with the exchanged metal ion and the amount of metal ions exchanged into zeolite decreases in the sequence Pb(II) > Cu(II) > Co(II). Application of the metal-ion-exchanged zeolites in oxidation of cyclohexane in liquid phase with visible light was examined and it is observed that the order of reactivity of the zeolites for the conversion of cyclohexane to cyclohexanone and cyclohexanol is CuY > CoY > PbY. It is found that conversion increases by increase of the empty active sites of a zeolite and the formation of cyclohexanol is favored initially, but the cyclohexanol is subsequently converted to cyclohexanone.

  12. Modification of the cation exchange resin properties by impregnation in polyethyleneimine solutions: application to the separation of metallic ions. (United States)

    Amara, Mourad; Kerdjoudj, Hacène


    A commercial cation exchange resin Amberlite 200 has been modified after immersion in solutions of polyethyleneimine (PEI). The kinetic of fixation of the metallic ions have been determined. The modification of the surface of the resin deals with a change in the order of the affinities of the resins towards cations. The retention is the function of the formation and the stability of the complex. The conditions of modification (pH, PEI concentration and time of immersion) have been examined and the modification was confirmed by the determination of the exchange capacities, the distribution coefficient (P) and the selectivity factors (S). The obtained results revealed the effect of PEI on the exchange properties of the resin. The pH range selected (6-8) permitted a good adherence of PEI onto the resin surface. The quantity of the adsorbed PEI was increased by raising the initial concentration and the immersion period. The exchange capacity for copper ion passed from 2.6 mmol g(-1), in the case of unmodified resin, to 3.9 mmol g(-1) for the modified one.

  13. Ion exchange in the nuclear industry

    Energy Technology Data Exchange (ETDEWEB)

    Bibler, J.P.


    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.

  14. Ion exchange in the nuclear industry

    Energy Technology Data Exchange (ETDEWEB)

    Bibler, J.P.


    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.

  15. Ion-exchange chromatographic protein refolding. (United States)

    Freydell, Esteban J; van der Wielen, Luuk; Eppink, Michel; Ottens, Marcel


    The application of ion-exchange (IEX) chromatography to protein refolding (IExR) has been successfully proven, as supported by various studies using different model proteins, ion-exchange media and flow configurations. Ion-exchange refolding offers a relatively high degree of process intensification, represented by the possibility of performing protein refolding, product purification and product concentration, in one unit operation. Besides its high degree of process intensification, IExR offers an additional set of key advantages including: spatial isolation of the bound protein molecules and the controllable change in chemical composition using gradients. Despite of the acknowledgement of the former advantages, the lack of mechanistic understanding on how they influence the process performance of the ion-exchange refolding reactor, limits the ability to exploit them in order to optimize the performance of the unit. This paper presents a quantitative analysis that assesses the effect that the spatial isolation and the urea gradient, have on the IExR performance, judged on the basis of the refolding yield (Y(N)) and the fractional mass recovery (f(Prot,Rec)). Additionally, this work discusses the effect of the protein load, the protein loading state (i.e., native, denatured, denatured and reduced (D&R)) and the adsorbent type on f(Prot,Rec). The presented work shows: (1) that the protein load has a direct effect on f(Prot,Rec), and the magnitude of this effect depends on the loading state of the protein solution and the adsorbent type; (2) that irrespectively of the type of adsorbent used, the saturation capacity of a denatured protein is less than the native protein and that this difference can be linked to differences in accessible binding surface area; (3) that there is a clear correlation between fractional surface coverage (θ) and f(Prot,Rec), indicating that the former could serve as a good descriptor to assess spatial isolation, and (4) that the urea

  16. Application of a Re-Pd bimetallic catalyst for treatment of perchlorate in waste ion-exchange regenerant brine. (United States)

    Liu, Jinyong; Choe, Jong Kwon; Sasnow, Zachary; Werth, Charles J; Strathmann, Timothy J


    Concentrated sodium chloride (NaCl) brines are often used to regenerate ion-exchange (IX) resins applied to treat drinking water sources contaminated with perchlorate (ClO(4)(-)), generating large volumes of contaminated waste brine. Chemical and biological processes for ClO(4)(-) reduction are often inhibited severely by high salt levels, making it difficult to recycle waste brines. Recent work demonstrated that novel rhenium-palladium bimetallic catalysts on activated carbon support (Re-Pd/C) can efficiently reduce ClO(4)(-) to chloride (Cl(-)) under acidic conditions, and here the applicability of the process for treating waste IX brines was examined. Experiments conducted in synthetic NaCl-only brine (6-12 wt%) showed higher Re-Pd/C catalyst activity than in comparable freshwater solutions, but the rate constant for ClO(4)(-) reduction measured in a real IX waste brine was found to be 65 times lower than in the synthetic NaCl brine. Through a series of experiments, co-contamination of the IX waste brine by excess NO(3)(-) (which the catalyst reduces principally to NH(4)(+)) was found to be the primary cause for deactivation of the Re-Pd/C catalyst, most likely by altering the immobilized Re component. Pre-treatment of NO(3)(-) using a different bimetallic catalyst (In-Pd/Al(2)O(3)) improved selectivity for N(2) over NH(4)(+) and enabled facile ClO(4)(-) reduction by the Re-Pd/C catalyst. Thus, sequential catalytic treatment may be a promising strategy for enabling reuse of waste IX brine containing NO(3)(-) and ClO(4)(-).

  17. Separation processes in biotechnology. Ion-exchange processes. (United States)

    Shuey, C D


    Through the use of several differentiating mechanisms, ion exchangers can separate ionic and nonionic materials, solutions containing only ionic species, and even completely nonionic mixtures. Although the mechanisms are distinct in their mode of operation, the resin characteristics that influence the results are largely the same. A practical understanding of the resin properties involved is all that is necessary to begin to use ion-exchange resins successfully. Ion exchange owes most of its history to water treatment, which has provided the economic and technological driving force in the past for the development of improved resins. However, specialty applications such as those in biotechnology are steadily becoming major factors in industry, perhaps not in shear volumes of resin used, but certainly in the value added by the process. The field of biotechnology no doubt holds many of the exciting new applications for ion exchange.

  18. Application of the Nernst-Planck approach to lead ion exchange in Ca-loaded Pelvetia canaliculata. (United States)

    Costa, Joana F de Sá S; Vilar, Vítor J P; Botelho, Cidália M S; da Silva, Eduardo A B; Boaventura, Rui A R


    Ca-loaded Pelvetia canaliculata biomass was used to remove Pb(2+) in aqueous solution from batch and continuous systems. The physicochemical characterization of algae Pelvetia particles by potentiometric titration and FTIR analysis has shown a gel structure with two major binding groups - carboxylic (2.8 mmol g(-1)) and hydroxyl (0.8 mmol g(-1)), with an affinity constant distribution for hydrogen ions well described by a Quasi-Gaussian distribution. Equilibrium adsorption (pH 3 and 5) and desorption (eluents: HNO(3) and CaCl(2)) experiments were performed, showing that the biosorption mechanism was attributed to ion exchange among calcium, lead and hydrogen ions with stoichiometry 1:1 (Ca:Pb) and 1:2 (Ca:H and Pb:H). The uptake capacity of lead ions decreased with pH, suggesting that there is a competition between H(+) and Pb(2+) for the same binding sites. A mass action law for the ternary mixture was able to predict the equilibrium data, with the selectivity constants alpha(Ca)(H)=9+/-1 and alpha(Ca)(Pb)=44+/-5, revealing a higher affinity of the biomass towards lead ions. Adsorption (initial solution pH 4.5 and 2.5) and desorption (0.3M HNO(3)) kinetics were performed in batch and continuous systems. A mass transfer model using the Nernst-Planck approximation for the ionic flux of each counter-ion was used for the prediction of the ions profiles in batch systems and packed bed columns. The intraparticle effective diffusion constants were determined as 3.73x10(-7)cm(2)s(-1) for H(+), 7.56x10(-8)cm(2)s(-1) for Pb(2+) and 6.37x10(-8)cm(2)s(-1) for Ca(2+). Copyright 2010 Elsevier Ltd. All rights reserved.

  19. Speciation of selenoamino acids, selenonium ions and inorganic selenium by ion exchange HPLC with mass spectrometric detection and its application to yeast and algae

    DEFF Research Database (Denmark)

    Larsen, Erik Huusfeldt; Hansen, M.; Fan, T.


    Cation and anion exchange HPLC were used to separate a mixture of 12 selenium species comprising selenoamino acids, selenonium ions and inorganic selenium. The cationic species were separated from each other and from the co-injected anions using a cation exchange column with gradient elution...... by aqueous pyridinium formate at pH similar to 3 as the mobile phase. The anionic species were separated using an anion exchange column with isocratic elution by an aqueous salicylate-TRIS mobile phase at pH 8.5. The separated selenium species were detected as Se-80 by ICP-dynamic reaction cell (DRC......)-MS. The analytical methods were applied to the analysis of yeast and algae enriched in selenium. The yeast was treated with beta -glucosidase followed by a protease mixture for dissolution of the cell walls and selenium-containing peptides, respectively. The second to largest HPLC peak after that corresponding...

  20. 离子交换材料在药物传递系统的应用%Application of Ion Exchange Material on Drug Delivery System

    Institute of Scientific and Technical Information of China (English)

    李国芝; 周冬菊


    Ion exchange material as a kind of new pharmaceutical polymer material was widely used in pharmaceutics in recent years,and the research on the drug delivery system(DDS) was rapid.But there were many shortcomings in the application.The types and performance of ion exchange material,and the application on DDS were summed up.The future direction of ion exchange material was offered.%离子交换材料作为一种新型的药用高分子材料近年来在药剂学中的应用广泛,在药物传递系统中的应用研究迅速。但离子交换技术及离子交换材料在药剂学中的应用仍存在许多不足。归纳了离子交换材料的种类、特性,以及离子交换材料作为药物载体在药物制剂方面的应用。提出了研制功能性离子交换树脂辅料将是未来发展方向。

  1. UV-exposed Bragg gratings for laser applications in silver-sodium ion-exchanged phosphate glass waveguides. (United States)

    Yliniemi, Sanna; Albert, Jacques; Wang, Qing; Honkanen, Seppo


    High reflectivity Bragg gratings have been written by ArF excimer laser through a phase mask into IOG-1 hybrid phosphate glass. After grating exposure, a waveguide was fabricated by silver-sodium ion-exchange. Reflectivities around 80% at a wavelength of ~ 1535 nm were measured from the waveguide for both quasi-TE and -TM polarizations. Waveguide laser operation with the photowritten waveguide grating as another mirror was demonstrated. Output power of 3.8 mW with a pump power of 199 mW could be extracted from the laser configuration.

  2. Recent advances in polymer monoliths for ion-exchange chromatography. (United States)

    Nordborg, Anna; Hilder, Emily F


    The use of polymeric materials in ion-exchange chromatography applications is advantageous because of their typically high mechanical stability and tolerance of a wide range of pH conditions. The possibility of using polymeric monoliths in ion-exchange chromatography is therefore obvious and many of the same strategies developed for polymeric particles have been adapted for use with polymeric monoliths. In this review different strategies for the synthesis of polymeric monoliths with ion-exchange functionality are discussed. The incorporation of ion-exchange functionality by co-polymerization is included, as also are different post-polymerization alterations to the monolith surface such as grafting. The formulations and strategies presented include materials intended for use in analytical separations in ion-exchange chromatography, sample pre-treatment or enrichment applications, and materials for capillary electrochromatography. Finally, examples of the use of polymeric monoliths in ion-exchange chromatography applications are included with examples published in the years 2003 to 2008.

  3. Two-step K(+)-Na+ and Ag(+)-Na+ ion-exchanged glass waveguides for C-band applications. (United States)

    Zou, Jizuo; Zhao, Feng; Chen, Ray T


    A two-step K(+)-Na+ and Ag(+)-Na+ ion-exchange technique is introduced to fabricate single-mode channel waveguides in BK7 glass for the telecom-wavelength region. The dependencies of insertion loss, polarization-dependent loss (PDL), end bending loss of curved waveguides on channel width, diffusion time, and annealing time are investigated. Results show that postannealing is a required process for improving waveguide properties and an optimal annealing time exists. Although relatively narrow mask openings are used in most one-step ion-exchange processes, a wider channel width, to as wide as 10 microm, is preferred for this two-step method. The minimum coupling loss to/from single-mode fiber and the propagation loss is found to be 0.4 dB and 0.3 dB/cm, respectively. For 5-cm-long waveguides the PDL is less than 0.1 dB. For the S-bend structure the cosine curve exhibit apparently a lower bending loss than the double-arc curve.


    Directory of Open Access Journals (Sweden)

    George Halsey Beall


    Full Text Available In the past few years ion-exchange in glasses has found a renewed interest with a lot of new development and research in industrial and academic labs and the commercialization of materials with outstanding mechanical properties. These glasses are now widely used in many electronic devices including hand-held displays and tablets. The exchange is generally conducted in a bath of molten salt below the transition temperature of the glass. The exchange at the surface of an alkali ion by a bigger one brings compressive stress at the surface. The mechanical properties are dependent on the stress level at the surface and the depth of penetration of the bigger ion. As compared to glasses, glass-ceramics have the interest to display a wide range of aspects (transparent to opaque and different mechanical properties (especially higher modulus and toughness. There has been little research on ion-exchange in glass-ceramics. In these materials the mechanisms are much more complex than in glasses because of their polyphasic nature: ion-exchange generally takes place mostly in one phase (crystalline phase or residual glass. The mechanism can be similar to what is observed in glasses with the replacement of an ion by another in the structure. But in some cases this ion-exchange leads to microstructural modifications (for example amorphisation or phase change.This article reviews these ion-exchange mechanisms using several transparent and opaque alumino-silicate glass-ceramics as examples. The effect of the ion exchange in the various glass-ceramics will be described, with particular emphasis on flexural strength.

  5. Ion Exchange in Glass-Ceramics (United States)

    Beall, George; Comte, Monique; Deneka, Matthew; Marques, Paulo; Pradeau, Philippe; Smith, Charlene


    In the past few years ion-exchange in glasses has found a renewed interest with a lot of new development and research in industrial and academic labs and the commercialization of materials with outstanding mechanical properties. These glasses are now widely used in many electronic devices including hand-held displays and tablets. The exchange is generally conducted in a bath of molten salt below the transition temperature of the glass. The exchange at the surface of an alkali ion by a bigger one brings compressive stress at the surface. The mechanical properties are dependent on the stress level at the surface and the depth of penetration of the bigger ion. As compared to glasses, glass-ceramics have the interest to display a wide range of aspects (transparent to opaque) and different mechanical properties (especially higher modulus and toughness). There has been little research on ion-exchange in glass-ceramics. In these materials the mechanisms are much more complex than in glasses because of their polyphasic nature: ion-exchange generally takes place mostly in one phase (crystalline phase or residual glass). The mechanism can be similar to what is observed in glasses with the replacement of an ion by another in the structure. But in some cases this ion-exchange leads to microstructural modifications (for example amorphisation or phase change). This article reviews these ion-exchange mechanisms using several transparent and opaque alumino-silicate glass-ceramics as examples. The effect of the ion exchange in the various glass-ceramics will be described, with particular emphasis on flexural strength.

  6. Quantitatively measured photorefractive sensitivity of proton-exchanged lithium niobate, proton-exchanged magnesium oxide-doped lithium niobate, and ion-exchanged potassium titanyl phosphate waveguides. (United States)

    Kondo, Y; Miyaguchi, S; Onoe, A; Fujii, Y


    The photorefractive sensitivities of proton-exchanged lithium niobate waveguides and Rb-ion-exchanged potassium titanyl phosphate waveguides are quantitatively measured, and their influence on waveguide applications is estimated.

  7. Effect of polyamine reagents on exchange capacity in ion exchangers (United States)

    Petrova, T. I.; Dyachenko, F. V.; Bogatyreva, Yu. V.; Borodastov, A. K.; Ershova, I. S.


    Effect of compounds involved in complex reagents is described using Helamin 906H reagent as an example. The working exchange capacity of KU-2-8chs cation exchanger in hydrogen form and Amberlite IRA 900Cl anion exchanger in OH form remained almost unchanged when they were used repeatedly to purify water that contained Helamin 906H reagent; in addition, this capacity was the same upon filtration of water that did not contain this reagent. Leakage of total organic carbon was observed earlier than that of calcium ions upon filtration of the solution through the cation exchanger layer. The test results obtained in industrial conditions indicated that using H-OH filters to purify turbine condensate enables the decrease of the concentration of organic and other impurities therein.

  8. Modeling of Crystalline Silicotitanate Ion Exchange Columns

    Energy Technology Data Exchange (ETDEWEB)

    Walker, D.D.


    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.

  9. Adsorption and solvent desorption behavior of ion-exchanged modified Y zeolites for sulfur removal and for fuel cell applications. (United States)

    Lin, Ligang; Zhang, Yuzhong; Zhang, Hongyu; Lu, Fuwei


    Typical ion-exchanged modified Y zeolites (AgY and CeY) were prepared for sulfur removal. The adsorption and desorption behavior of typical sulfur and hydrocarbon molecules in various Y zeolites has been investigated by the adsorption breakthrough and on site solvent washing experiments, as well as computer simulation. Breakthrough experiments showed that the adsorption capacity for thiophenic sulfur increased for the studied adsorbents as follows: CeY > AgY > NaY. The higher initial sulfur concentration accelerated the appearance of breakthrough, and the outlet sulfur concentration, in all cases, cannot reach the corresponding initial sulfur level. The concentration profile of washing solvent during desorption process showed that most of the sulfur compounds could be recovered at initial desorption stage. The desorption rates of typical Y zeolites follow the order: NaY > AgY > CeY, which is the reverse as that found in adsorption capacity. The distinct adsorption and desorption behavior of CeY, AgY, and NaY zeolites was markedly related with their various binding force (S-M coordination, π-complexation, and Van der Waals force) with sulfur compounds. The adsorption isotherms and density distribution snapshots study by computer simulation confirmed the preferential adsorption of thiophenic sulfur.

  10. Hybrids perfluorosulfonic acid ionomer and silicon oxide membrane for application in ion-exchange polymer-metal composite actuators

    Institute of Scientific and Technical Information of China (English)


    This paper reports a new technique to fabricate an ion-exchange polymer-metal composite (IPMC) actuator. This technique is based on a hybrid organic-inorganic composite membrane. In the fabrication course, silica oxide particles, prepared from hydrolysis of tetraethyl orthosilicate in situ with sol-gel reaction, co-crystallize with perfluorosulfonate acid (PFSA) ionomer. Attenuated total reflectance fourier transform infrared spectroscopy (ATR-FTIR) analyses demonstrate that a highly water-saving hybrid membrane is formed. Measurements of mechanical properties reveal that elastic modulus and hardness of the hybrid membrane are about 2 times compared to a commercial PFSA membrane. Scanning electron microscopy (SEM) results show that the hybrid membrane has a high porosity. Inside the membrane pores, there exists a great quantity of micro scale channels in the range of 100―300 nm. After fabrication of IPMC actuator, an electric current sensor, a force sensor, and a high speed camera are assembled and used to evaluate IPMC performance. It is shown that, compared to an IPMC actuator made from a commercial membrane, the electromechanical performance of the new actuator increases 6―8 times; when it is actuated in air, its stable non-water working time is prolonged for 6―7 times.

  11. Phosphorus-contained polycondensation type ion-exchange resins

    Directory of Open Access Journals (Sweden)

    Tulkun Tursunov


    Full Text Available This work describes synthesis and research of new polycondensation type phosphorus-contained ion-exchange polymers by phosphorylation of polymers received through the interaction of furfural (accessible and cheap product of hydrolytic and cotton scraping industry of Uzbekistan with benzyl bromide (chloride. Furfural and its derivatives possess high reactionary ability thanks to presence of carbonyl groups, and presence of a heterocyclic cycle gives to the received polymers high thermal and chemical stability. Polycondensation reaction kinetics of furfural and benzyl bromide, and phosphorylation reaction of the received benzyl bromide-furfural polymer were studied. Sorption, kinetic and thermo-chemical properties of received ion-exchange resins were studied using physico-chemical and chemical analyses to find out specific objects of practical application. Particularly, sorption and selective properties of received ion-exchange resins to ions of such metals as copper, nickel, calcium, magnesium, and uranyl ion were studied. Received results support the application of the investigated ion-exchange resins in processes of clearing of industrial and waste waters of hydrometallurgical manufactures.


    Institute of Scientific and Technical Information of China (English)



    Water sorption isotherms available in the literatures of Na+-from of Dowex 50W×4 and×8,BioRex-70,Amberlyst-15,Nafion-117,hydrous titanium oxide,crystalline zirconium phosphate and zinc hexacyanoferrate(Ⅱ),have been analysed by the D′Arcy and Watt equation.Hydration of Na+ in the ion exchangers is the predominant interaction of sorbed water.The correlation between the hydration numbers and those obtained for electrolyte solution is found in this paper.Qualitative implications of the state of sorbed water in the ion exchangers on its various characteristic quantities like selectivity,are briefly discussed.

  13. Ion exchange tempering of glass ophthalmic lenses. (United States)

    Keeney, A H; Duerson, H L


    We performed low velocity drop-ball tests using 5/8-, 7/8-, and 1-inch diameter steel balls on ophthalmic crown glass lenses chemically tempered by the ion exchange process. Four representative dioptric strengths (+ 2.50 spherical, - 2.50 spherical, -2.50 cylindrical, and plano) were studied with the isolated lenses mounted, convex side up, on the American National Standards Institute Z80 test block. New ion exchange lenses exhibited a 100 to 350% greater capacity for attenuation of energy from low velocity, large size missiles than matched lenses of similar strength prepared by the conventional heat-treating and air-quenching process.

  14. Determination of boron in silicates after ion exchange separation (United States)

    Kramer, H.


    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.

  15. Ion exchange performance of commercial crystalline silicotitanates for cesium removal

    Energy Technology Data Exchange (ETDEWEB)

    Braun, R.; Dangieri, T.J.; Fennelly, D.J. [and others


    A new class of inorganic ion exchangers called crystalline silicotitanates (CST), invented by researchers at Sandia National Laboratories and Texas A&M University, has been commercialized in a joint Sandia-UOP effort. The original developmental materials exhibited high selectivity for the ion exchange of cesium, strontium, and several other radionuclides from highly alkaline solutions containing molar concentrations of Na{sup +}. The materials also showed excellent chemical and radiation stability. Together, the high selectivity and stability of the CSTs made them excellent candidates for treatment of solutions such as the Hanford tank supernates and other DOE radwastes. Sandia National Laboratories and UOP have teamed under a Cooperative Research and Development Agreement (CRADA) to develop CSTs in the powdered form and in an engineered form suitable for column ion exchange use. A continuous-flow, column ion exchange process is expected to be used to remove Cs and other radionuclides from the Hanford supernatant. The powder material invented by the Sandia and Texas A&M team consists of submicron-size particles. It is not designed for column ion exchange but may be used in other applications.

  16. Thermal Analysis of LANL Ion Exchange Column

    Energy Technology Data Exchange (ETDEWEB)

    Laurinat, J.E.


    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.

  17. Radiation effects on ion exchange materials

    Energy Technology Data Exchange (ETDEWEB)

    Gangwer, T.E.; Goldstein, M.; Pillay, K.K.S.


    An extensive literature review and data compilation has been completed on the radiation-damage of ion exchange resins. The primary goal of the study has been to review the available literature on ion exchange materials used in, as well as those with potential for use in, the nuclear fuel and waste reprocessing areas. The physical and chemical properties of ion exchangers are reviewed. Experimental parameters useful in characterizing the effects of radiation on synthetic ion exchange resins are identified or defined. In compiling the diverse types of data, an effort was made to present the experimental data or experimentally based parameters in a format that would be useful for inter-comparing radiation effects on resins. When subject to radiation there are various general trends or qualitative effects displayed by the different types of resins. These radiation-trends and effects have been formulated into qualitative statements. The present day level of understanding of the behavior of resins under ionizing radiation is too limited to justify quantitative predictive modeling. The limitations and deficiencies of the literature are discussed and the experimentation needed to achieve quantitative modeling are outlined. 14 figs., 108 references.

  18. Specific ion effects on membrane potential and the permselectivity of ion exchange membranes

    KAUST Repository

    Geise, Geoffrey M.


    © the Partner Organisations 2014. Membrane potential and permselectivity are critical parameters for a variety of electrochemically-driven separation and energy technologies. An electric potential is developed when a membrane separates electrolyte solutions of different concentrations, and a permselective membrane allows specific species to be transported while restricting the passage of other species. Ion exchange membranes are commonly used in applications that require advanced ionic electrolytes and span technologies such as alkaline batteries to ammonium bicarbonate reverse electrodialysis, but membranes are often only characterized in sodium chloride solutions. Our goal in this work was to better understand membrane behaviour in aqueous ammonium bicarbonate, which is of interest for closed-loop energy generation processes. Here we characterized the permselectivity of four commercial ion exchange membranes in aqueous solutions of sodium chloride, ammonium chloride, sodium bicarbonate, and ammonium bicarbonate. This stepwise approach, using four different ions in aqueous solution, was used to better understand how these specific ions affect ion transport in ion exchange membranes. Characterization of cation and anion exchange membrane permselectivity, using these ions, is discussed from the perspective of the difference in the physical chemistry of the hydrated ions, along with an accompanying re-derivation and examination of the basic equations that describe membrane potential. In general, permselectivity was highest in sodium chloride and lowest in ammonium bicarbonate solutions, and the nature of both the counter- and co-ions appeared to influence measured permselectivity. The counter-ion type influences the binding affinity between counter-ions and polymer fixed charge groups, and higher binding affinity between fixed charge sites and counter-ions within the membrane decreases the effective membrane charge density. As a result permselectivity decreases. The

  19. Simultaneously Tailoring Surface Energies and Thermal Stabilities of Cellulose Nanocrystals Using Ion Exchange: Effects on Polymer Composite Properties for Transportation, Infrastructure, and Renewable Energy Applications. (United States)

    Fox, Douglas M; Rodriguez, Rebeca S; Devilbiss, Mackenzie N; Woodcock, Jeremiah; Davis, Chelsea S; Sinko, Robert; Keten, Sinan; Gilman, Jeffrey W


    Cellulose nanocrystals (CNCs) have great potential as sustainable reinforcing materials for polymers, but there are a number of obstacles to commercialization that must first be overcome. High levels of water absorption, low thermal stabilities, poor miscibility with nonpolar polymers, and irreversible aggregation of the dried CNCs are among the greatest challenges to producing cellulose nanocrystal-polymer nanocomposites. A simple, scalable technique to modify sulfated cellulose nanocrystals (Na-CNCs) has been developed to address all of these issues. By using an ion exchange process to replace Na(+) with imidazolium or phosphonium cations, the surface energy is altered, the thermal stability is increased, and the miscibility of dried CNCs with a nonpolar polymer (epoxy and polystyrene) is enhanced. Characterization of the resulting ion exchanged CNCs (IE-CNCs) using potentiometry, inverse gas chromatography, dynamic vapor sorption, and laser scanning confocal microscopy reveals that the IE-CNCs have lower surface energies, adsorb less water, and have thermal stabilities of up to 100 °C higher than those of prepared protonated cellulose nanocrystals (H-CNCs) and 40 °C higher than that of neutralized Na-CNC. Methyl(triphenyl)phosphonium exchanged cellulose nanocrystals (MePh3P-CNC) adsorbed 30% less water than Na-CNC, retained less water during desorption, and were used to prepare well-dispersed epoxy composites without the aid of a solvent and well-dispersed polystyrene nanocomposites using a melt blending technique at 195 °C. Predictions of dispersion quality and glass transition temperatures from molecular modeling experiments match experimental observations. These fiber-reinforced polymers can be used as lightweight composites in transportation, infrastructure, and renewable energy applications.

  20. SPEEDUP{trademark} ion exchange column model

    Energy Technology Data Exchange (ETDEWEB)

    Hang, T.


    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.

  1. An Empirical Formula From Ion Exchange Chromatography and Colorimetry. (United States)

    Johnson, Steven D.


    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)

  2. Multi-modal applicability of a reversed-phase/weak-anion exchange material in reversed-phase, anion-exchange, ion-exclusion, hydrophilic interaction and hydrophobic interaction chromatography modes. (United States)

    Lämmerhofer, Michael; Nogueira, Raquel; Lindner, Wolfgang


    We recently introduced a mixed-mode reversed-phase/weak anion-exchange type separation material based on silica particles which consisted of a hydrophobic alkyl strand with polar embedded groups (thioether and amide functionalities) and a terminal weak anion-exchange-type quinuclidine moiety. This stationary phase was designed to separate molecules by lipophilicity and charge differences and was mainly devised for peptide separations with hydroorganic reversed-phase type elution conditions. Herein, we demonstrate the extraordinary flexibility of this RP/WAX phase, in particular for peptide separations, by illustrating its applicability in various chromatographic modes. The column packed with this material can, depending on the solute character and employed elution conditions, exploit attractive or repulsive electrostatic interactions, and/or hydrophobic or hydrophilic interactions as retention and selectivity increments. As a consequence, the column can be operated in a reversed-phase mode (neutral compounds), anion-exchange mode (acidic compounds), ion-exclusion chromatography mode (cationic solutes), hydrophilic interaction chromatography mode (polar compounds), and hydrophobic interaction chromatography mode (e.g., hydrophobic peptides). Mixed-modes of these chromatographic retention principles may be materialized as well. This allows an exceptionally flexible adjustment of retention and selectivity by tuning experimental conditions. The distinct separation mechanisms will be outlined by selected examples of peptide separations in the different modes.

  3. Porous solid ion exchange wafer for immobilizing biomolecules (United States)

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


    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.


    NARCIS (Netherlands)



    The film-diffusion-limited ion exchange kinetics for the HCl-NaCl and HCl-CaCl2 systems on a Lewatit S100 ion exchanger are investigated. The ion exchange processes are modelled using the Maxwell-Stefan transport equations. The model uses only one fitting parameter. the film thickness, the Maxwell-S

  5. Cesium and strontium ion specific exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Yates, S.


    This work is one of two parallel projects that are part of an ESP task to develop high-capacity, selective, solid extractants for cesium, strontium, and technetium from nuclear wastes. In this subtask, Pacific Northwest National Laboratory (PNNL) is collaborating with AlliedSignal, Inc. (Des Plaines, Illinois) to develop inorganic ion exchangers that are selective for strontium and cesium from alkaline high-level waste and groundwater streams.

  6. PRTR ion exchange vault water removal

    Energy Technology Data Exchange (ETDEWEB)

    Ham, J.E.


    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.

  7. Polymethylmethacrylate open tubular ion exchange columns: nondestructive measurement of very small ion exchange capacities. (United States)

    Zhang, Min; Yang, Bingcheng; Dasgupta, Purnendu K


    We describe an approach to prepare an open tubular ion exchange (OTIE) column by coating a monolayer of anion exchange nanoparticle to a 16-20 μm bore polymethylmethacrylate (PMMA) capillary. The latex nanoparticle was electrostatically attached to carboxylate groups on the inner wall of capillary, pretreated with strong base for hydrolyzing the ester. Several approaches to nondestructively measure ion exchange capacities (IEC) of the columns were examined: (a) adsorption-desorption of an intensely fluorescent ion, e.g. fluorescein, and off-line fluorometry, (b) loading a weakly retained ion (e.g., IO3(-)), frontal displacement by a strongly bound ion (e.g., Cl(-)), and online optical or conductometric boundary detection, and (c) similar to the above except displacement being accompanied by reaction (e.g., acid-base titration). To our knowledge, this is the first time on-column titration has been used to measure capacities. By using different pH displacer solutions, we demonstrate for the first time the possibility of pKa-differentiated ion exchange capacity measurements. The cation exchange capacity of bare PMMA capillaries was on the order of 1 pequiv/mm(2) with little dependence on time and temperature of hydrolysis conditions. After AS18 latex coating, the strong base anion exchange capacity was on the order of 10 pequiv/mm(2), very close to what would be estimated on the basis of monolayer coverage of the surface by individual latex particles. The latex used contained a significant, additional amount of weak base character, about the same as the strong base ion exchange capacity.

  8. Novel silica-based ion exchange resin

    Energy Technology Data Exchange (ETDEWEB)

    Gula, M.; Harvey, J.


    Shortcomings of chelating resins have been addressed by a new class of ion exchange resins called dual mechanism bifunctional polymers (DMBPs). DMBPs use hydrophilic cation exchange ligands with rapid uptake kinetics and use chelating ligands for selectivity for one or more metals; result is a resin that quickly recognizes and removes targeted metals from waste, remediation, and process streams. Eichrom`s Diphonix {reg_sign} resin is the first DMBP to be widely released as a commercial product; it is polystyrene based. Objective of this work is to synthesize commercial quantities of a silica-based ion exchange resin with the same or better metal ion selectivity, metal uptake kinetics, and acid stability as Diphonix. Feasibility was determined, however the process needs to be optimized. Studies at Eichrom and ANL of the performance of Diphonix resin over a broad range of HNO3 and HCl conditions and inorganic salt loadings are discussed together with the proposed method of incorporating similar characteristics into a silica-based resin. The new, silica-based resin functionalized with diphosphonic acid ligands can be used in environmental restoration and waste management situations involving processing of low-level, transuranic, and high-level radioactive wastes; it can also be used for processing liquid mixed waste including wastes contaminated with organic compounds.

  9. The rapid and direct determination of ATPase activity by ion exchange chromatography and the application to the activity of heat shock protein-90. (United States)

    Bartolini, Manuela; Wainer, Irving W; Bertucci, Carlo; Andrisano, Vincenza


    Adenosine nucleotides are involved as substrates or co-factors in several biochemical reactions, catalyzed by enzymes, which modulate energy production, signal transduction and cell proliferation. We here report the development and optimization of an ion exchange liquid chromatography (LC) method for the determination of ATP, ADP and AMP. This method is specifically aimed at the determination of the ATP-ase activity of human heat shock protein 90 (Hsp90), a molecular chaperone that has emerged as target enzyme in cancer therapy. Separation of the three nucleotides was achieved in a 15-min run by using a disk shaped monolithic ethylene diamine stationary phase of small dimensions (2mm×6mm i.d.), under a three-solvent gradient elution mode and UV detection at 256nm. The described direct LC method resulted highly specific as a consequence of the baseline separation of the three adenosine nucleotides and could be applied to the determination of the enzymatic activity of ADP/ATP generating or consuming enzymes (such as kinases). Furthermore, comparison of the LOD and LOQ values of the LC method with those obtained with the malachite green assay, which is one of the most used indirect screening methodologies for ATP-ase activity, showed that the LC method has a similar range of application without presenting the drawbacks related to contamination by inorganic phosphate ions and glycerol, which are present in Hsp90 commercial samples.

  10. 全钒液流电池隔膜材料进展%Ion Exchange Membranes for Vanadium Redox Flow Battery Applications

    Institute of Scientific and Technical Information of China (English)

    刘红丽; 高艳; 谢光有


    全钒液流电池是一种新型的高效储能电池, 离子交换膜作为其核心功能部件之一, 得到广泛研究. 本文综述了商业化和改性阳离子交换膜、 阴离子交换膜、 两性离子交换膜的制备方法、 结构特点、 电池效率, 并从钒电池电堆和系统性能及寿命出发, 讨论了上述膜材料的优缺点.%Vanadium Redox Flow Battery ( VRB) is receiving more attention due to its technical advantages for large scale energy storage applications. As the key component of VRB, Ion Exchange Membrane ( IEM ) is responsible for transferring ions and preventing electrolyte from crossing over between positive and negative electrodes during the charge and discharge process of VRB. In this paper, the recent R&D progress of three types of IEM, including cation, anion and amphoteric membranes, are reviewed in terms of their fabrication method, composition and performance. Also, the pros and cons of the membranes are discussed regarding their VRB stack and system performance and lifetime.

  11. Electrically switched cesium ion exchange. FY 1997 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Lilga, M.A.; Orth, R.J.; Sukamto, J.P.H. [and others


    This paper describes the Electrically Switched Ion Exchange (ESIX) separation technology being developed as an alternative to ion exchange for removing radionuclides from high-level waste. Progress in FY 1997 for specific applications of ESIX is also outlined. The ESIX technology, which combines ion exchange and electrochemistry, is geared toward producing electroactive films that are highly selective, regenerable, and long lasting. During the process, ion uptake and elution can be controlled directly by modulating the potential of an ion exchange film that has been electrochemically deposited onto a high surface area electrode. This method adds little sodium to the waste stream and minimizes the secondary wastes associated with traditional ion exchange techniques. Development of the ESIX process is well underway for cesium removal using ferrocyanides as the electroactive films. Films having selectivity for perrhenate (a pertechnetate surrogate) over nitrate also have been deposited and tested. Based on the ferrocyanide film capacity, stability, rate of uptake, and selectivity shown during performance testing, it appears possible to retain a consistent rate of removal and elute cesium into the same elution solution over several load/unload cycles. In batch experiments, metal hexacyanoferrate films showed high selectivities for cesium in concentrated sodium solutions. Cesium uptake was unaffected by Na/Cs molar ratios of up to 2 x 10{sup 4} , and reached equilibrium within 18 hours. During engineering design tests using 60 pores per inch, high surface area nickel electrodes, nickel ferrocyanide films displayed continued durability. losing less than 20% of their capacity after 1500 load/unload cycles. Bench-scale flow system studies showed no change in capacity or performance of the ESIX films at a flow rate up to 13 BV/h, the maximum flow rate tested, and breakthrough curves further supported once-through waste processing. 9 refs., 24 figs.

  12. Using ion exchange chromatography to purify a recombinantly expressed protein. (United States)

    Duong-Ly, Krisna C; Gabelli, Sandra B


    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.

  13. Ion exchange properties of humus acids (United States)

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


    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.

  14. Anion exchangers with branched functional ion exchange layers of different hydrophilicity for ion chromatography. (United States)

    Shchukina, O I; Zatirakha, A V; Smolenkov, A D; Nesterenko, P N; Shpigun, O A


    Novel polystyrene-divinylbenzene (PS-DVB) based anion exchangers differing from each other in the structure of the branched functional ion exchange layer are prepared to investigate the role of linker and functional site on ion exchange selectivity. The proposed method of synthesis includes the obtaining of aminated PS-DVB particles by means of their acylation with following reductive amination with methylamine. Further modification of the obtained secondary aminogroups is provided by the alkylation with either 1,4-butanediol diglycidyl ether (1,4-BDDGE) or resorcinol diglycidyl ether (RDGE), which form the linkers of different hydrophobicity, and amination of terminal epoxide rings with trimethylamine (TMA), dimethylethanolamine (DMEA), methyldiethanolamine (MDEA) or triethanolamine (TEA). The variation of the structure and hydrophobicity of the linker and terminal quaternary ammonium sites in the functional layer allows the alteration of selectivity and separation efficiency of the obtained adsorbents. The ion exchange selectivity and separation efficiency of the anion exchangers are evaluated using the model mixtures of anions (F(-), HCOO(-), Cl(-), NO2(-), Br(-), NO3(-), HPO4(2-) and SO4(2-)) in potassium hydroxide eluents. The adsorbents show the decrease of selectivity with increasing the hydrophilicity of the terminal functional site. The anion exchangers having more flexible and hydrophilic 1,4-BDDGE linker provide smaller separation factors for most of the analytes as compared with RDGE-containing adsorbents with the same terminal ion exchange sites, but are characterized with higher column efficiencies and better peak symmetry for polarizable anions. In case of 1,4-BDDGE-modified anion exchangers of the particle size of 3.3μm functionalized with DMEA and MDEA the calculated values of column efficiencies for polarizable NO3(-) and Br(-) are up to 49,000 and 53,000N/m, respectively, which is almost twice higher than the values obtained for the RDGE

  15. Microbial treatment of ion exchange resins

    Energy Technology Data Exchange (ETDEWEB)

    Kouznetsov, A.; Kniazev, O. [D. Mendeleyev University of Chemical Technology of Russia, Dept. Biotechnology, Mocow (Russian Federation)


    A bioavailability of ion exchange resins to a microbial destruction as one of the alternative methods of compacting used ionites from the nuclear fuel manufacturing cycle enterprises has been investigated. The bio-destruction was studied after a preliminary chemical treatment or without it. A sensitivity of the ion exchange resins (including highly acidic cationite KU-2-8) to the microbial destruction by heterotrophic and chemo-litho-trophic microorganisms under aerobic conditions was shown in principle. The biodegradation of the original polymer is possible in the presence of the water soluble fraction of the resin obtained after its treatment by Fenton reagent and accelerated in the presence of Mn-ions in optimal concentration 1-2 g of Mn per liter of medium. Thus, the process of bio-destruction of ionite polymer by heterotrophic microorganisms can be compared with the bio-destruction of lignin or humic substances. The optimum parameters of bio-destruction and microorganisms used must be different for resins with different functional groups. (authors)

  16. Optimization of ion exchange in polishers at PWRs

    Energy Technology Data Exchange (ETDEWEB)

    Miller, A.D. [Pedro Point Technology, Inc., Pacifica, CA (United States); Fruzzetti, K. [Electric Power Research Inst., Palo Alto, CA (United States)


    Blowdown polishers are indispensable components in the secondary systems of pressurized water reactors. The application of advanced amines to reduce iron levels in final steam generator feedwater influences the resin selection for and operation of condensate polishers. There are many opportunities to optimize blowdown polisher performance. This paper summarizes the work currently underway to optimally use resin properties such as ion selectivity and capacity and operational parameters to maximize water quality while minimizing cost. It is shown that the best amine for a given power plant is a complex function of amine properties, ion exchange resin choice, purification systems and other plant design and operational parameters. (orig.)

  17. Characterization of oligosaccharides with capillary high performance anion exchange chromatography hyphenated to pulsed amperometric detection and ion trap mass spectrometry : application to the analysis of human lysosomal disorders

    NARCIS (Netherlands)

    Bruggink, Cornelis


    The development of a capillary ion chromatograph is described together with a matching desalter. This desalter made it possible to use on-line a mass spectrometer. The mass spectrometer enables partly to characterize carbohydrates eluting from the anion exchange column. This separation technology is

  18. Application of linear pH gradients for the modeling of ion exchange chromatography: Separation of monoclonal antibody monomer from aggregates. (United States)

    Kluters, Simon; Wittkopp, Felix; Jöhnck, Matthias; Frech, Christian


    The mobile phase pH is a key parameter of every ion exchange chromatography process. However, mechanistic insights into the pH influence on the ion exchange chromatography equilibrium are rare. This work describes a mechanistic model capturing salt and pH influence in ion exchange chromatography. The pH dependence of the characteristic protein charge and the equilibrium constant is introduced to the steric mass action model based on a protein net charge model considering the number of amino acids interacting with the stationary phase. This allows the description of the adsorption equilibrium of the chromatographed proteins as a function of pH. The model parameters were determined for a monoclonal antibody monomer, dimer, and a higher aggregated species based on a manageable set of pH gradient experiments. Without further modification of the model parameters the transfer to salt gradient elution at fixed pH is demonstrated. A lumped rate model was used to predict the separation of the monoclonal antibody monomer/aggregate mixture in pH gradient elution and for a pH step elution procedure-also at increased protein loadings up to 48 g/L packed resin. The presented model combines both salt and pH influence and may be useful for the development and deeper understanding of an ion exchange chromatography separation.


    Institute of Scientific and Technical Information of China (English)

    LingDaren; LiuYucheng; 等


    The self-diffusion of Eu3+ ion in porous resins D72 and D751 was studied by isotope exchange reaction.Applying Kataoka's bidisperse pore model,the intraparticle effective diffusivity De were resolved into a solid diffusivity Dg and a macropore diffusivity Dp.The experiments show that De.Dp and Dg all increase with the increase of reaction temperature;the response Dp and Dg of D751 resin is smaller than that of D72 resin;the diffusivity of Eu3+ ion in solution is larger than Dp,which leads to the conclusion that the diffusion of ion in the pore of resin can not completely be equal to that in solution.

  20. Ion exchange materials, method of forming ion exchange materials, and methods of treating liquids (United States)

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


    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.

  1. Grafted megaporous materials as ion-exchangers for bioproduct adsorption. (United States)

    Bibi, Noor Shad; Fernández-Lahore, Marcelo


    Megaporous chromatographic materials were manufactured by a three-step procedure, including backbone synthesis, chemical grafting, and introduction of ion-exchange functionality. The backbone of the adsorbent cylindrical bodies was prepared by polymerization of methacrylic acid and poly(ethylene glycol) diacrylate at sub-zero temperatures. Grafting was performed employing glycidyl methacrylate and a chemical initiator, cerium ammonium nitrate. The degree of grafting was adjusted by modifying the concentration of the initiator in the reaction mixture to a range of values (23, 39, 62, 89, and 105%). Further, the pendant epoxy-groups generated by the previous step were reacted to cation- and anion-exchanging moieties utilizing known chemical routes. Infrared spectroscopy studies confirmed the incorporation of epoxy and ion-exchanger groups to the backbone material. Optimized materials were tested for chromatography applications with model proteins; the dynamic binding capacity, as recorded at 10% breakthrough and 2.0 × 10(-4) m/s superficial velocity, were 350 and 58 mg/g for the cation-exchanger and the anion-exchanger material, respectively. These results may indicate that long tentacle-type polymer brushes were formed during grafting therefore increasing the ability of the megaporous body to efficiently capture macromolecules.

  2. Ion Exchange Chromatography and Spectrophotometry: An Introductory Undergraduate Laboratory Experiment. (United States)

    Foster, N.; And Others


    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)

  3. Multicomponent liquid ion exchange with chabazite zeolites

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  4. Birefringence control for ion-exchanged channel glass waveguides. (United States)

    Ayräs, P; Conti, G N; Honkanen, S; Peyghambarian, N


    We show that at 1.55-mum wavelength the waveguide birefringence of ion-exchanged channel waveguides in glass can be broadly tuned by a potassium and silver double-ion exchange. Two different potassium and silver double-ion-exchange processes are used to make surface waveguides with negligible waveguide birefringence. This process is crucially important in the manufacture of devices for dense wavelength-division multiplexing systems. The dependence of the waveguide birefringence on the channel width is also reported.

  5. Mineral Separation in a CELSS by Ion-exchange Chromatography (United States)

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


    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.

  6. Preparation and characterization of electrically conducting polypyrrole Sn(IV phosphate cation-exchanger and its application as Mn(II ion selective membrane electrode

    Directory of Open Access Journals (Sweden)

    A.A. Khan


    Full Text Available Polypyrrole Sn(IV phosphate, an organic–inorganic composite cation-exchanger was synthesized via sol-gel mixing of an organic polymer, polypyrrole, into the matrices of the inorganic precipitate of Sn(IV phosphate. The physico-chemical properties of the material were determined using Atomic Absorption Spectrometry (AAS, CHN elemental analysis (inductively coupled plasma mass spectrometry, ICP-MS, UV–VIS spectrophotometry, FTIR (Fourier Transform Infra-Red, SEM (Scanning Electron Microscopy, TGA–DTA (Thermogravimetric Analysis–Differential Thermal Analysis, and XRD (X-ray diffraction. Ion-exchange behavior was observed to characterize the material. On the basis of distribution studies, the material was found to be highly selective for toxic heavy metal ion Mn2+. Due to its selective nature, the material was used as an electroactive component for the construction of an ion-selective membrane electrode. The proposed electrode shows fairly good discrimination of mercury ion over several other inorganic ions. The analytical utility of this electrode was established by employing it as an indicator electrode in electrometric titrations for Mn(II in water.

  7. Zeolitic ammonium ion exchange for portable hemodialysis dialysate regeneration. (United States)

    Patzer, J F; Yao, S J; Wolfson, S K


    Ammonia removal from a recirculating dialysate stream is a major challenge in developing a truly portable, regenerable hemodialysis system. Three zeolites, type F, type W, and clinoptilolite, were found to have good ammonia ion exchange capacity with linear equilibrium ion exchange coefficients of 0.908, 0.488, and 0.075 L/g, respectively. The linear equilibrium ion exchange coefficient relates dialysate ammonia concentration (mumol/L) to the amount of ammonia absorbed by zeolite (mumol/g) at equilibrium. Ammonia uptake by zeolite powders was fast, with equilibrium reached within 15 sec. Zeolite ammonia ion exchange and regeneration through multiple cycles was studied using an ion exchange column containing clinoptilolite pellets. Zeolite ion exchange capability was regenerated by flushing the column with 2 mol/L sodium chloride after an ion exchange run. The column maintained ammonia ion exchange capacity through six ion exchange/regeneration cycles, demonstrating multiple dialysis use possibilities. Atomic absorption spectroscopy of the column effluent showed no detectible (< 1 part per million) Si or Al leached from the zeolite.


    Institute of Scientific and Technical Information of China (English)

    HAOJinku; ZHAOWeijun; 等


    Gas phase reduction of carbon monoxide to formaldehyde and ethylene was found in electrochemical cell with an inorganic ion exchanger α-Zr(HPO4)2·H2O used as solid proton-conducting electrolyte at room temperature and atmospheric pressure.The type and amount of the electroreduction of CO depend on the different metal electrodes and current densities,which gives a lank between heterogeneous catalysis and electrochemistry.

  9. Characterization of ion-exchange membrane materials: properties vs structure. (United States)

    Berezina, N P; Kononenko, N A; Dyomina, O A; Gnusin, N P


    This review focuses on the preparation, structure and applications of ion-exchange membranes formed from various materials and exhibiting various functions (electrodialytic, perfluorinated sulphocation-exchange and novel laboratory-tested membranes). A number of experimental techniques for measuring electrotransport properties as well as the general procedure for membrane testing are also described. The review emphasizes the relationships between membrane structures, physical and chemical properties and mechanisms of electrochemical processes that occur in charged membrane materials. The water content in membranes is considered to be a key factor in the ion and water transfer and in polarization processes in electromembrane systems. We suggest the theoretical approach, which makes it possible to model and characterize the electrochemical properties of heterogeneous membranes using several transport-structural parameters. These parameters are extracted from the experimental dependences of specific electroconductivity and diffusion permeability on concentration. The review covers the most significant experimental and theoretical research on ion-exchange membranes that have been carried out in the Membrane Materials Laboratory of the Kuban State University. These results have been discussed at the conferences "Membrane Electrochemistry", Krasnodar, Russia for many years and were published mainly in Russian scientific sources.

  10. Raman microspectroscopy investigation of Ag ion-exchanged glass layers. (United States)

    Rahman, A; Giarola, M; Cattaruzza, E; Gonella, F; Mardegan, M; Trave, E; Quaranta, A; Mariotto, G


    The ion-exchange process is widely used to dope silicate glass layers with silver, aimed at controlling the Ag state in view of possible applications, ranging from light waveguide fabrication to nanostructured composite glass synthesis. The silver doped glass structure as well as its prescribed properties depend on both the preparation parameters and the subsequent treatments. Several structural aspects are still open with regard either to the modification of the glass incorporating the dopant, or to clustering phenomena silver undergoes as a function of its local concentration and state, which are in turn strongly dependent on the preparation route. Systematic characterizations of these systems are mandatory to address the role of the various synthesis parameters in giving rise to the observed features, thus pointing out the effective methodologies for the fabrication of silicate glass layers with the desired properties. In this work, the results of micro-Raman, optical absorption and photoluminescence characterizations are presented for soda-lime glass slides doped with silver by Ag(+)-Na+ exchange and subsequent thermal treatments in air. In particular, a cross-section profiling analysis by Raman micro-spectroscopy was performed on Ag ion-exchanged samples after treatment at some different temperatures. The experimental findings allow to elucidate the role of the treatment temperature in the clustering process related to the local Ag concentration inside the exchanged glass layer.

  11. Solid Phase Luminescence of Several Rare Earth Ions on Ion-Exchange Films (United States)

    Tanner, Stephen P.; Street, Kenneth W., Jr.


    The development and characterization of a novel ion-exchange film for solid-phase fluorometry and phosphorimetry is reported. This new cation-exchange material is suitable for spectroscopic applications in the ultraviolet and visible regions. It is advantageous because it, as a single entity, is easily recovered from solution and mounted in the spectrofluorometers. After preconcentration on the film, the luminescence intensity of lanthanide ions is several orders of magnitude greater than that of the corresponding solution, depending on the volume of solution and the amount of film. This procedure allows emission spectral measurements and determination of lanthanide ions at solution concentrations of < 5 (micro)g/L. The film may be stored for subsequent reuse or as a permanent record of the analysis. The major drawback to the use of the film is slow uptake of analyte due to diffusion limitations.

  12. Scintillating 99Tc Selective Ion Exchange Resins

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell Greenhalgh; Richard D. Tillotson


    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.

  13. Application of resistivity measurements to the control of protein elutions using cellulose ion-exchangers; Application de la mesure de resistivite au controle d'une elution de proteines a partir de celluloses echangeuses d'ions

    Energy Technology Data Exchange (ETDEWEB)

    Duplaa, A.M.; Brandolin, G. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires


    The eluate obtained by chromatography of a mixture of proteins on columns of cellulose ion-exchangers (DEAE-cellulose and CM-cellulose) sometimes have very low proteins concentrations. The resistivity measurement gives more information than the UV control which is often inadequate. The modifications undergone by elution buffers are recorded and the best conditions for the extraction of an enzymatic protein are determined. The tests are performed without proteins on the columns; they consist in a double control of resistivity and ph of elution buffers after they pass on the exchangers columns. (author) [French] Apres chromatographie d'un melange de proteine; sur colonnes d'echangeurs d'ions tels que DEAE-cellulose et CM-cellulose, les eluats obtenus ont quelquefois des concentrations en proteines tres faibles. Au controle en UV souvent insuffisant, on a ajoute la mesure de resistivite apportant des donnees complementaires. Des essais, realises en l'absence de proteines et consistant a effectuer un double controle de resistivite et de pH des tampons d'elution apres leur passage sur colonnes d'echangeurs, ont permis d'enregistrer les modifications subies par ces tampons et de determiner leurs meilleures conditions d'utilisation pour l'extraction d'une proteine enzymatique. (auteur)

  14. Controlled porosity monolithic material as permselective ion exchange membranes. (United States)

    Huang, Xiaojia; Dasgupta, Purnendu K


    Ion exchange membranes (IEMs) are used in a variety of analytical devices, including suppressors, eluent generators and other components used in ion chromatography. Such membranes are flexible and undergo substantial dimensional changes on hydration. Presently the push to miniaturization continues; a resurgent interest in open tubular ion chromatography requires microscale adaptation of these components. Incorporating IEMs in microscale devices is difficult. Although both macroporous and microporous ion exchange materials have been made for use as chromatographic packing, ion exchange material used as membranes are porous only on a molecular scale. Because such pores have vicinal ion exchange sites, ions of the same charge sign as those of the fixed sites are excluded from the IEMs. Monolithic polymers, including ion exchangers derived therefrom, are presently extensively used. When used in a separation column, such a monolithic structure contains an extensively connected porous network. We show here that by controlling the amount of porogen added during the synthesis of monolithic polymers derived from ethylene dimethacrylate - glycidyl methacrylate, which are converted to an anion exchanger by treatment with trimethylamine, it is possible to obtain rigid ion exchange polymers that behave like IEMs and allow only one charge type of ions to pass through, i.e., are permselective. We demonstrate successful open tubular cation chromatography suppressor performance.

  15. Ion-exchange chromatography separation applied to mineral recycle in closed systems (United States)

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


    As part of the controlled ecological life support system (CELSS) program, a study is being made of mineral separation on ion-exchange columns. The purpose of the mineral separation step is to allow minerals to be recycled from the oxidized waste products of plants, man, and animals for hydroponic food production. In the CELSS application, relatively large quantities of minerals in a broad concentration range must be recovered by the desired system, rather than the trace quantities and very low concentrations treated in analytical applications of ion-exchange chromatography. Experiments have been carried out to assess the parameters pertinent to the scale-up of ion-exchange chromatography and to determine feasibility. Preliminary conclusions are that the column scale-up is in a reasonable size range for the CELSS application. The recycling of a suitable eluent, however, remains a major challenge to the suitability of using ion exchange chromatography in closed systems.

  16. Study on actinoid isolation by antimonide ion exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Tsuji, Masamichi [Tokyo Inst. of Tech. (Japan). Faculty of Science; Kubota, Masumitsu; Yamagishi, Isao


    To establish a containment of long-life nuclides and an effective reduction of waste volume is important to reduce the loadings on the natural environment. Chemical isolation of radioactive nuclides from wastes was attempted by using inorganic ion exchanger with high specificity and thermal stability. In this study, titanium antimonide was used as an ion exchanger to investigate the adsorption of trivalent metallic ions according to Kielland plot curves. When the ionic equivalent fraction (X-bar{sub M}) was around 0.005, Kielland plot curve of either of 3-valent metallic ions was bent, suggesting the exchanger had two different adsorption sites. The slope of the curve became smaller as an elevation of temperature. These results show that the ion radius was decreased resulting from partial elimination of the hydrated water of ion and thus, the steric conditions around the exchange site might be improved. (M.N.)

  17. Local structures of ions at ion-exchange resin/solution interface. (United States)

    Harada, Makoto; Okada, Tetsuo


    The local structures of Cl- and Br- in anion-exchange resins have been studied by X-ray absorption fine structure (XAFS), and separation selectivity is discussed on the basis of results. When two different anion-exchange resins having trimethylammonium and dimethylammonium groups as anion-exchange groups are employed for ion-exchange experiments, slightly higher Br- selectivity has been obtained with the former. XAFS has indicated that the average hydration numbers for a given anion is not affected by the structure of the ion-exchange group, but that the extent of ion-association between the anion and the ion-exchange groups depends on the type of the ion-exchange group. Shorter interaction distance (and in turn stronger ion-association) has been confirmed for the dimethylammonium-type resin, and is consistent with lower Br- selectivity of this resin.

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


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


    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 co...

  19. New Inorganic Ion-exchange Material for the Selective Removal of Fluoride from Potable Water Using Ion-selective Electrode

    Directory of Open Access Journals (Sweden)

    Rasheed M.A.Q. Jamhour


    Full Text Available An ion-exchange procedure involving the selective retention of fluoride ions from aqueous solutions containing 1, 5, 10, 20 and 50 mg F- L-1 using a new inorganic ion exchanger zirconium(IV oxide-ethanolamine ZrO-EA and its application to fluoride removal from potable water has been described. A column equilibrium studies, batch process and different analytical parameters such as concentration, pH and temperature for the quantitative recoveries of F- ion using ZrO-EA exchanger were investigated and determined by an ion selective electrode. The effect of some other anions that might be present with the analyte was also examined. The column experiments showed a quantitative collection of fluoride at low concentration in water samples with more than 96% recovery.

  20. 离子交换非织造布在电去离子技术中的应用%Application of the ion exchange nonwovens in the electrodeionization (EDI) technology

    Institute of Scientific and Technical Information of China (English)

    刘慧; 左惟昌; 高雨芹; 黄惠娟; 朱新生


    Electrodeionization ( EDI) is a new membrane separation technology of combining electrodialysis and ion exchange.One of the core EDI techniques is the seeking and application of filling materials.The effect of the filling pattern of ion exchange nonwovens on the EDI current, the electrical conductivities of the dilute and the concentrate exit waters, and the removal of copper ions were investigated.The results indicated that ion exchange nonwovens not only shortens the distance of directional diffusion and migration of ions, but also improves the filling uniform of ion exchange resin.As a result, the rate of ion migration of EDI stack increases significantly, and thus both the conductivity of concentrate exit water and the copper ( II) removal of the dilute exit soar up substantially, while the conductivity of the dilute exit decrease remarkably.For the membrane stack constructions of three-dilute two-concentrate system, the conductivity of dilute exit water was decreased by 90% while that of the concentrate exit rised by 9 times, and the copper ion removal reached up to nearly 100%, while the construction with all ion exchange nonwovens filled was compared with that only with the ion exchange resin.This finding exposes a broad prospect of the ion exchange nonwovens in the heavy metal ions wastewater treatment.%电去离子技术(EDI)是将电渗析与离子交换有机结合形成的一种新型膜分离技术,EDI膜堆的核心技术之一是填充材料的选择与应用。探讨了离子交换非织造布填充方式对膜堆电流、淡水室和浓水室出水电导率以及铜离子去除率等性能的影响。实验结果表明:采用离子交换非织造布缩短了离子的定向扩散和迁移距离,并有利于离子交换树脂的均匀填充,可明显提高离子迁移速率,使淡水室出水电导率大幅下降,浓水室出水电导率大幅上升,铜离子去除率提高;在三淡二浓膜堆结构中,全部填充离子交

  1. A Simple and Efficient Method for Purification of Egg White Major Proteins Using Ion Exchange Chromatography


    Sh. Veisi; A. Mostafaie; Z. Mohammad Hasan


    Introduction & Objective: Egg white contains four high-quantity proteins which have numerous applications. In this research, a simple and efficient method for the purification of those proteins was designed and performed based on ion exchange chromatography.Materials & Methods: In this experimental study egg white was initially separated from insoluble substances by acidic pH. The resulting extract was isolated after two steps of ion exchange chromatography using CM-Sepharose and DEAE-Sepharo...

  2. Influence of Ionic Liquids on the Selectivity of Ion Exchange-Based Polymer Membrane Sensing Layers. (United States)

    Mendecki, Lukasz; Callan, Nicole; Ahern, Meghan; Schazmann, Benjamin; Radu, Aleksandar


    The applicability of ion exchange membranes is mainly defined by their permselectivity towards specific ions. For instance, the needed selectivity can be sought by modifying some of the components required for the preparation of such membranes. In this study, a new class of materials -trihexyl(tetradecyl)phosphonium based ionic liquids (ILs) were used to modify the properties of ion exchange membranes. We determined selectivity coefficients for iodide as model ion utilizing six phosphonium-based ILs and compared the selectivity with two classical plasticizers. The dielectric properties of membranes plasticized with ionic liquids and their response characteristics towards ten different anions were investigated using potentiometric and impedance measurements. In this large set of data, deviations of obtained selectivity coefficients from the well-established Hofmeister series were observed on many occasions thus indicating a multitude of applications for these ion-exchanging systems.

  3. Enhanced capacity and stability for the separation of cesium in electrically switched ion exchange

    Energy Technology Data Exchange (ETDEWEB)

    Tawfic, A.F.; Dickson, S.E.; Kim, Y. [McMaster University, Hamilton, ON (Canada); Mekky, W. [AMEC NSS, Power and Process America, Toronto (Canada)


    Electrically switched ion exchange (ESIX) can be used to separate ionic contaminants from industrial wastewater, including that generated by the nuclear industry. The ESIX method involves sequential application of reduction and oxidation potentials to an ion exchange film to induce the respective loading and unloading of cesium. This technology is superior to conventional methods (e.g electrodialysis reversal or reverse osmosis) as it requires very little energy for ionic separation. In previous studies, ESIX films have demonstrated relatively low ion exchange capacities and limited film stabilities over repeated potential applications. In this study, the methodology for the deposition of electro-active films (nickel hexacyanoferrate) on nickel electrodes was modified to improve the ion exchange capacity for cesium removal using ESIX. Cyclic voltammetry was used to investigate the ion exchange capacity and stability. Scanning electron microscopy (SEM) was used to characterize the modified film surfaces. Additionally, the films were examined for the separation of cesium ions. This modified film preparation technique enhanced the ion exchange capacity and improves the film stability compared to previous methods for the deposition of ESIX films. (authors)


    Directory of Open Access Journals (Sweden)

    M.A.S.D. de Barros


    Full Text Available Ion exchange isotherms are very important tools to achieve a better comprehension of cation removal by means of zeolite treatment. In this work, three isotherms were obtained (at 298K, at 313K and at 333K from natural pretreated Na+ clinoptilolite. The ion exchange was carried out with Cr+3 ions. The isotherms’ shape is similar to the classical type "b" isotherm, according to the arrangement proposed by Breck (1984. Mathematical fitting was applied to the experimental points (Table Curve software to obtain a representative curve thereof. From such fittings, points were simulated and then used to construct the Kielland plots, whose shape was associated with an ion exchange mechanism. Straight lines were obtained as an indication that, although the zeolite used is of natural occurrence and presents impurities such as mordenite and clays, only one site is involved in the ion exchange process

  5. Hydrolyzed Poly(acrylonitrile) Electrospun Ion-Exchange Fibers. (United States)

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


    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.

  6. Application of a chromatography model with linear gradient elution experimental data to the rapid scale-up in ion-exchange process chromatography of proteins. (United States)

    Ishihara, Takashi; Kadoya, Toshihiko; Yamamoto, Shuichi


    We applied the model described in our previous paper to the rapid scale-up in the ion exchange chromatography of proteins, in which linear flow velocity, column length and gradient slope were changed. We carried out linear gradient elution experiments, and obtained data for the peak salt concentration and peak width. From these data, the plate height (HETP) was calculated as a function of the mobile phase velocity and iso-resolution curve (the separation time and elution volume relationship for the same resolution) was calculated. The scale-up chromatography conditions were determined by the iso-resolution curve. The scale-up of the linear gradient elution from 5 to 100mL and 2.5L column sizes was performed both by the separation of beta-lactoglobulin A and beta-lactoglobulin B with anion-exchange chromatography and by the purification of a recombinant protein with cation-exchange chromatography. Resolution, recovery and purity were examined in order to verify the proposed method.

  7. A study on dry decontamination using ion exchange polymer

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Ki Jung; Ahn, Byung Gil


    Through the project of {sup A} study on dry decontamination using ion exchange polymer{sup ,} the followings were investigated. 1. Highly probable decontamination technologies for the decontamination were investigated. 2. Development of gel type decontamination agent using ion-exchange resin powder (mixed type) as an ion exchanger. 3. Manufacturing of contaminated specimens (5 kinds) with Cs-137 solution and dust / Cs-137 solution. 4. Decontamination performance evaluation of the manufactured agent. 5. Analysis of composition (XRF) and the structure of surface of specimens (optic micrography). (author). 20 refs., 11 figs.

  8. Sers-Active Silver Nanoparticles in Ion-Exchanged Glass (United States)

    Chen, Ya; Jaakola, Janne; Säynätjoki, Antti; Tervonen, Ari; Honkanen, Seppo

    We study synthesis and SERS activity of glass-embedded ion-exchanged silver nanoparticles formed by two different methods. Silver-sodium ion-exchange process with heat treatment was utilized on commercial microscope slides, while masked ion-exchange technique was performed on glass Corning 0211. The distribution of particles was studied by absorption spectroscopy and atomic force microscopy. After etching the glass surface to expose the particles, SERS performance of these particles was investigated with micro-Raman spectroscopy using Rhodamine 6G as the analyte.

  9. Ion Exchange Testing with SRF Resin FY2012

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  10. Superheated water ion-exchange chromatography: an experimental approach for interpretation of separation selectivity in ion-exchange processes. (United States)

    Shibukawa, Masami; Shimasaki, Tomomi; Saito, Shingo; Yarita, Takashi


    Cation-exchange selectivity for alkali and alkaline-earth metal ions and tetraalkylammonium ions on a strongly acidic sulfonic acid cation-exchange resin has been investigated in the temperature range of 40-175 degrees C using superheated water chromatography. Dependence of the distribution coefficient (ln KD) on the reciprocal of temperature (1/T) is not linear for most of the ions studied, and the selectivity coefficient for a pair of alkali metal ions or that of alkaline-earth metal ions approaches unity as temperature increases. On the other hand, the retention order of tetraalkylammonium ions is reversed at 160 degrees C or above when eluted with Na2SO4 aqueous solution and the larger ions are eluted faster than the smaller ones contrary to the retention order obtained at ambient temperature. The change in ion-exchange selectivity with temperature observed with superheated water chromatography has been discussed on the basis of the effect of temperature on hydration of the ions and specific adsorption or distribution of ionic species between the external solution and ion-exchange resin. In superheated water, the electrostatic interaction or association of the ions with the fixed ion becomes a predominant mechanism resulting in different separation selectivity from that obtained at ambient temperature.

  11. Tc-99 Ion Exchange Resin Testing

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  12. Ion exchange at TNX using the SKID unit

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, M.L.; Bibler, J.P.


    An ion exchange unit has been manufactured for WSRC by British Nuclear Fuels, Ltd. This unit consists of three columns, ancillary valving, pumps, lines, and computer controls. It has been delivered to TNX for use in testing a cesium-specific ion exchange resin, developed at WSRC as a potential second generation process for the decontamination of Defense Waste Processing Facility (DWPF) supernate. This resin also has Department of Energy applications at both Oak Ridge and Hanford. Oak Ridge is interested in decontaminating the Melton Valley storage tank supernate, while Hanford is interested in decontaminating the 101-AW and 101-SY supernate streams. Another potential developmental interest is the Savannah River Site (SRS) DWPF recycle stream. The three primary waste streams of interest are the Oak Ridge, Hanford, and SRS, SWPF supernate streams. For these three waste streams, the cesium decontamination factor (DF) will be measured for a non-radioactive, simulated, high-level waste solution. The test objectives, process outlines, and broad characterization of the waste streams are described.

  13. Modeling radial flow ion exchange performance for condensate polisher conditions

    Energy Technology Data Exchange (ETDEWEB)

    Shallcross, D. [University of Melbourne, Melbourne, VIC (Australia). Department of Chemical Engineering; Renouf, P.


    A theoretical model is developed which simulates ion exchange performance within an annular resin bed. Flow within the mixed ion exchange bed is diverging, with the solution flowing outwards away from the bed's axis. The model is used to simulate performance of a mixed annular bed operating under condensate polisher conditions. The simulation predictions are used to develop design envelope curves for practical radial flow beds and to estimate potential cost savings flowing from less expensive polisher vessels. (orig.)

  14. Samarium Ion Exchanged Montmorillonite for High Temperature Cumene Cracking Reaction (United States)

    Binitha, N. N.; Silija, P. P.; Suraj, V.; Yaakob, Z.; Sugunan, S.


    Montmorillonite clay is cation exchanged with samarium and its catalytic influence in cumene cracking reaction is investigated. Effect of exchange with sodium ions on further exchange with samarium ions is also noted. Acidity measurements are done using Temperature Programmed Desorption (TPD) of ammonia. The retention of basic structure is proved from FTIR spectra and XRD patterns. Elemental analysis result shows that samarium exchange has occurred, which is responsible for the higher catalytic activity. Surface area and pore volume remains more or less unaffected upon exchange. Thermogravimetric analysis indicates the enhanced thermal stability on exchanging. Cumene cracking reaction is carried out at atmospheric pressure in a fixed bed glass reactor at 673 K. The predominance of Brønsted acidity is confirmed from high selectivity to benzene.

  15. Samarium Ion Exchanged Montmorillonite for High Temperature Cumene Cracking Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Binitha, N N; Silija, P P; Yaakob, Z [Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, National University of Malaysia, 43600 UKM Bangi, Selangor (Malaysia); School of Materials Engineering, Universiti Malaysia Perlis, Taman Muhibah, 02600, Jejawi, Perlis (Malaysia); Suraj, V [Department of Applied Chemistry, CUSAT, Cochin 22, Kerala (India); Sugunan, S, E-mail: [National Institute of Technology, Calicut, Kerala (India)


    Montmorillonite clay is cation exchanged with samarium and its catalytic influence in cumene cracking reaction is investigated. Effect of exchange with sodium ions on further exchange with samarium ions is also noted. Acidity measurements are done using Temperature Programmed Desorption (TPD) of ammonia. The retention of basic structure is proved from FTIR spectra and XRD patterns. Elemental analysis result shows that samarium exchange has occurred, which is responsible for the higher catalytic activity. Surface area and pore volume remains more or less unaffected upon exchange. Thermogravimetric analysis indicates the enhanced thermal stability on exchanging. Cumene cracking reaction is carried out at atmospheric pressure in a fixed bed glass reactor at 673 K. The predominance of Broensted acidity is confirmed from high selectivity to benzene.

  16. Degradation mechanism of sulfonated poly(ether ether ketone) (SPEEK) ion exchange membranes under vanadium flow battery medium. (United States)

    Yuan, Zhizhang; Li, Xianfeng; Hu, Jinbo; Xu, Wanxing; Cao, Jingyu; Zhang, Huamin


    The degradation mechanism of hydrocarbon ion exchange membranes under vanadium flow battery (VFB) medium was investigated and clarified for the first time. This work will be highly beneficial for improving the chemical stability of hydrocarbon ion exchange membranes, which is one of the most challenging issues for VFB application.


    Energy Technology Data Exchange (ETDEWEB)

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


    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.


    NARCIS (Netherlands)



    In ion exchange, water and several ions diffuse simultaneously, with different velocities. They are driven by activity, electrical and pressure gradients. We describe these complicated processes with the Maxwell-Stefan equation. This equation for multicomponent diffusion requires one diffusivity or

  19. Advanced ion exchange resins for PWR condensate polishing

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, B. [Rohm and Haas Co. (United States); Tsuzuki, S. [Rohm and Haas Co. (Japan)


    The severe chemical and mechanical requirements of a pressurized water reactor (PWR) condensate polishing plant (CPP) present a major challenge to the design of ion exchange resins. This paper describes the development and initial operating experience of improved cation and anion exchange resins that were specifically designed to meet PWR CPP needs. Although this paper focuses specifically on the ion exchange resins and their role in plant performance, it is also recognized and acknowledged that excellent mechanical design and operation of the CPP system are equally essential to obtaining good results. (authors)

  20. Determination of Sc by Ion-exchanger Colorimetry

    Institute of Scientific and Technical Information of China (English)


    Ion-exchanger colorimetry for scandium in the form of ternary color system "Sc(Ⅲ)-CPA-pc-Ac" was developed. The influences of types and grain sizes of resin, adsorption modes and the acidity on the determination were studied systematically, and the optimum operating conditions and the allowable amounts of foreign ions were determined. In comparison with the ordinary solution colorimetry, both of the sensitivity and the selectivity of this ion-exchanger colorimetry are improved obviously. The preliminary uses of this method to the determination of Sc(Ⅲ) in two synthetic samples were satisfied.

  1. Rate theory on water exchange in aqueous uranyl ion (United States)

    Dang, Liem X.; Vo, Quynh N.; Nilsson, Mikael; Nguyen, Hung D.


    We report a classical rate theory approach to predict the exchange mechanism that occurs between water and aqueous uranyl ion. Using our water and ion-water polarizable force field and molecular dynamics techniques, we computed the potentials of mean force for the uranyl ion-water pair as a function of different pressures at ambient temperature. These potentials of mean force were used to calculate rate constants using transition rate theory; the transmission coefficients also were examined using the reactive flux method and Grote-Hynes approach. The computed activation volumes are positive; thus, the mechanism of this particular water-exchange is a dissociative process.

  2. Negative Joule Heating in Ion-Exchange Membranes


    Biesheuvel, P. M.; D. Brogioli; Hamelers, H. V. M.


    In ion-exchange membrane processes, ions and water flow under the influence of gradients in hydrostatic pressure, ion chemical potential, and electrical potential (voltage), leading to solvent flow, ionic fluxes and ionic current. At the outer surfaces of the membranes, electrical double layers (EDLs) are formed (Donnan layers). When a current flows through the membrane, we argue that besides the positive Joule heating in the bulk of the membrane and in the electrolyte outside the membrane, t...


    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  4. Ion-exchange chromatographic analysis of peroxynitric acid. (United States)

    Nakashima, Yoichi; Ikawa, Satoshi; Tani, Atsushi; Kitano, Katsuhisa


    Ion-exchange chromatographic analysis of peroxynitric acid (O2NOOH) was performed by combining an acidic eluate with an UV-vis detector and immersing the separation column in an ice-water bath. The decomposition behavior of peroxynitric acid in the solution was also studied using this system. The fraction for the peroxynitric acid peak was collected. Ion-exchange chromatographic analysis of this fraction, after standing at room temperature for 24h, showed that the decomposition products were mainly nitrate ions with a very small amount of nitrous acid. The peroxynitric acid peak area correlated perfectly with the total amount of decomposition products. The ion-exchange chromatographic isolation allowed us to evaluate the molar extinction coefficient of peroxynitric acid precisely in a wider wavelength range than previous reports. The value decreases monotonically from 1729±26M(-1)cm(-1) at 200nm to 12.0±0.5M(-1)cm(-1) at 290nm.

  5. Study on the permselectivity of ion exchange membrane

    Institute of Scientific and Technical Information of China (English)


    Ion exchange membranes with high permselectivity (the character of separating cations from anions or anions from cations) and high selectivity (the character of separating cations or anions of different valencies) are important for electrodialysis process. The Donnan equilibrium theory, based on the equilibrium of ions and no electric field, can not exactly explain the permselectivity of ion exchange membrane for ED process, since it is impossible to set up a ion exchange equilibrium between membrane and solution and to neglect the influence of electrical driving force on ions during ED process. A novel model named "anti-electric potential " is established to interpret the permselectivity of ion exchange membrane, according to the determination of electric potential between membranes and the variation of elements content in solutions and membranes. The results of experiment prove that the "anti-electric potential" really exists within membranes. As for the selectivity, the results reveal that electric potential and hydration energy have great influence on the concentration and mobility of ions in membranes.

  6. Cementation of residue ion exchange resins at Rocky Flats

    Energy Technology Data Exchange (ETDEWEB)

    Dustin, D.F.; Beckman, T.D.; Madore, C.M.


    Ion exchange resins have been used to purify nitric acid solutions of plutonium at Rocky Flats since the 1950s. Spent ion exchange resins were retained for eventual recovery of residual plutonium, typically by incineration followed by the aqueous extraction of plutonium from the resultant ash. The elimination of incineration as a recovery process in the late 1980s and the absence of a suitable alternative process for plutonium recovery from resins led to a situation where spent ion exchange resins were simply placed into temporary storage. This report describes the method that Rocky Flats is currently using to stabilize residue ion exchange resins. The objective of the resin stabilization program is: (1) to ensure their safety during interim storage at the site, and (2) to prepare them for ultimate shipment to the Waste Isolation Pilot Plant (WIPP) in New Mexico. Included in the discussion is a description of the safety concerns associated with ion exchange resins, alternatives considered for their stabilization, the selection of the preferred treatment method, the means of implementing the preferred option, and the progress to date.

  7. Effects of ion-exchange treatment on bromate formation and oxidation efficiency during ozonation


    Echigo, S.; Itoh, S.; Niwa, A


    Ion-exchange treatment is a promising technique for removing hydrophilic compounds during drinking water treatment. In this study, we applied several different ion exchangers (i.e., anion exchange resins and a hydrotalcite compound) to bromide removal to minimize bromate formation during ozonation. It was found that ion-exchange treatment affected ozone and hydroxyl radical concentration profiles as well as bromate ion concentration after ozonation. Selecting an appropriate ion exchanger is i...

  8. Ion exchange in KTiOPO4 crystals irradiated by copper and hydrogen ions. (United States)

    Zhang, Ruifeng; Lu, Fei; Lian, Jie; Liu, Hanping; Liu, Xiangzhi; Lu, Qingming; Ma, Hongji


    Cs(+)-K+ ion exchanges were produced on KTiOPO4 crystals which is prior irradiated by Cu+ can H+ ions. The energy and dose of implanted Cu+ ions are 1.5 MeV and 0.5 x 10(14) ions/cm2, and that of H+ are 300 keV and 1 x 10(16) ions/cm2, respectively. The temperature of ions exchange is 430 degrees C, and the time range from 15 minutes to 30 minutes. The prism coupling method is used to measure the dark mode spectra of the samples. Compared with results of ion exchange on the sample without irradiations, both the number of guided mode and its corresponding effective refractive index are decreased. The experimental results indicate that the ion exchange rate closely related with the lattice damage and the damage layers formed in the depth of maximum nuclear energy deposition act as a barrier to block the ions diffuse into the sample and the concentration of defects can modify the speed of ion exchange..

  9. Ion Exchange Testing with SRF Resin FY 2012

    Energy Technology Data Exchange (ETDEWEB)

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


    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.


    Natural clinoptilolite from Castle Creek, Idaho, and its cation-exchanged variants (Na-Cpt, NaK-Cpt, K-Cpt, and Ca-Cpt) were studied by high-temperature calorimetry. The hydration enthalpy for all clinoptilolites is about -30 kJ/mol H2O (liquid water reference state) at 25 C. T...

  11. Intensification of ammonia removal from waste water in biologically active zeolitic ion exchange columns. (United States)

    Almutairi, Azel; Weatherley, Laurence R


    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


    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  13. Development of a transparent, non-cytotoxic, silver ion-exchanged glass with antimicrobial activity and low ion elution. (United States)

    Shim, Gyu-In; Kim, Seong-Hwan; Eom, Hyung-Woo; Kim, Kwang-Mahn; Choi, Se-Young


    We investigated the antimicrobial, cytotoxicity, skin irritation, and ion elution behaviors of glass doped with silver ions with respect to its application to electronic equipment such as phones and tablet screens. The microbes tested were Escherichia coli, Staphylococcus aureus, and Penicillium funiculosum. AgNO3 powder was spread on both sides of aluminosilicate glass, and it was heated to 250-280°C for 10min. Under optimized heating conditions (260°C, 10min), the antimicrobial activity of ion-exchanged glass against bacteria and fungi was over 99.9% after 24 weeks. The glass failed to irritate the skin of experimental animals and was considered non-cytotoxic. The maximum amount of Ag ions that were eluted from the ion-exchanged glass into drinking water was measured at 0.037±0.003μgL(-1), an amount which is several orders of magnitude below the standard limit of 0.1mgL(-1) in drinking water. Ag ion-exchanged glass had characteristics suitable for use as a display screen, such as a light transmittance of 90% and a surface roughness of 0.704nm. Our findings suggest that glass doped with silver ions is more hygienic than non-doped glass is, and should be applied to display screens and glassware.

  14. Evaluation of electrochemical ion exchange for cesium elution

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  15. Catalysis using hydrous metal oxide ion exchanges (United States)

    Dosch, Robert G.; Stephens, Howard P.; Stohl, Frances V.


    In a process which is catalyzed by a catalyst comprising an active metal on a carrier, said metal being active as a catalyst for the process, an improvement is provided wherein the catalyst is a hydrous, alkali metal or alkaline earth metal titanate, zirconate, niobate or tantalate wherein alkali or alkaline earth metal cations have been exchanged with a catalytically effective amount of cations of said metal.

  16. Catalysis using hydrous metal oxide ion exchangers (United States)

    Dosch, R.G.; Stephens, H.P.; Stohl, F.V.


    In a process which is catalyzed by a catalyst comprising an active metal on a carrier, said metal being active as a catalyst for the process, an improvement is provided wherein the catalyst is a hydrous, alkali metal or alkaline earth metal titanate, zirconate, niobate or tantalate wherein alkali or alkaline earth metal cations have been exchanged with a catalytically effective amount of cations of said metal.

  17. Chromatographic separation of inorganic ions on thin layers of titanium phosphate ion-exchanger. (United States)

    Ghoulipour, Vanik; Safari, Moharram


    The chromatographic behavior of 30 inorganic cations has been studied on thin layers of titanium phosphate ion-exchanger using several aqueous, organic and mixed mobile phases. The separation of one ion from several other ions and also ternary and binary separations have been developed. Some important analytical separations are reported. The effect of pH of the mobile phase on retention factor (Rf) values of the cations in the presence of complex-forming anion along with the separation power of the ion-exchanger were studied. This ion-exchanger exhibits high sorption capacity and varying selectivity towards metal ions and makes it a suitable stationaiy phase in thin layer chromatography.

  18. Chromatographic separation of inorganic ions on thin layers of titanium phosphate ion-exchanger

    Institute of Scientific and Technical Information of China (English)

    Vanik GHOULIPOUR; Moharram SAFARI


    The chromatographic behavior of 30 inorganic cations has been studied on thin layers of titanium phosphate ion-exchanger using several aqueous,organic and mixed mobile phases. The separation of one ion from several other ions and also ternary and binary separations have been developed. Some important analytical separations are reported. The effect of pH of the mobile phase on retention factor(Rf)values of the cations in the presence of complex-forming anion along with the separation power of the ion-exchanger were studied. This ion-exchanger exhibits high sorption capacity and varying selectivity towards metal ions and makes it a suitable stationary phase in thin layer chromatography.

  19. Ultrafiltration Membrane Fouling and the Effect of Ion Exchange Resins

    KAUST Repository

    Jamaly, Sanaa


    Membrane fouling is a challenging process for the ultrafiltration membrane during wastewater treatment. This research paper determines the organic character of foulants of different kinds of wastewater before and after adding some ion exchange resins. Two advanced organic characterization methods are compared in terms of concentration of dissolved organic carbons: The liquid chromatography with organic carbon (LC-OCD) and Shimadzu total organic carbon (TOC). In this study, two secondary wastewater effluents were treated using ultrafiltration membrane. To reduce fouling, pretreatment using some adsorbents were used in the study. Six ion exchange resins out of twenty were chosen to compare the effect of adsorbents on fouling membrane. Based on the percent of dissolved organic carbon’s removal, three adsorbents were determined to be the most efficient (DOWEX Marathon 11 anion exchange resin, DOWEX Optipore SD2 polymeric adsorbent, and DOWEX PSR2 anion exchange), and three other ones were determined to the least efficient (DOWEX Marathon A2 anion exchange resin, DOWEX SAR anion exchange resin, and DOWEX Optipore L493 polymeric adsorbent). Organic characterization for feed, permeate, and backwash samples were tested using LC-OCD and TOC to better understand the characteristics of foulants to prevent ultrafiltration membrane fouling. The results suggested that the polymeric ion exchange resin, DOWEX SD2, reduced fouling potential for both treated wastewaters. All the six ion exchange resins removed more humic fraction than other organic fractions in different percent, so this fraction is not the main for cause for UF membrane fouling. The fouling of colloids was tested before and after adding calcium. There is a severe fouling after adding Ca2+ to effluent colloids.

  20. Rupture loop annex ion exchange RLAIX vault deactivation

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  1. Ion-exchanged Tm3+:glass channel waveguide laser. (United States)

    Choudhary, Amol; Kannan, Pradeesh; Mackenzie, Jacob I; Feng, Xian; Shepherd, David P


    Continuous wave laser action around 1.9 μm has been demonstrated in a Tm(3+)-doped germanate glass channel waveguide laser fabricated by ion-exchange. Laser action was observed with an absorbed power threshold of only 44 mW and a slope efficiency of up to 6.8% was achieved. Propagation loss at the lasing wavelength was measured to be 0.3 dB/cm. We believe this to be the first ion-exchanged Tm(3+)-doped glass waveguide laser.

  2. Waste separation and pretreatment using crystalline silicotitanate ion exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Tadros, M.E.; Miller, J.E. [Sandia National Lab., Albuquerque, NM (United States); Anthony, R.G. [Texas A& M Univ., College Station, TX (United States)


    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.

  3. A novel silica based click lysine anion exchanger for ion exchange chromatography. (United States)

    Guo, Hongyue; Chu, Changhu; Li, Yan; Yang, Bingcheng; Liang, Xinmiao


    Ion chromatography (IC) is one of the most powerful analysis technologies for the determination of charged compounds. A novel click lysine stationary phase was prepared via Cu(I) catalyzed alkyne-azide 1,3-dipolar cycloaddition (CuAAC) and applied to the analysis of inorganic ions. The chromatographic evaluation demonstrated good performance (e.g. the plate number of thiocyanate is ∼50,000 plates m(-1)) and effective separation ability for the common inorganic anions with aqueous Na(2)SO(4) eluent. The separation mechanism was observed to be mainly dominated by ion exchange interaction. The retention of these analytes is highly dependent on the pH value of eluent. Compared with the lysine stationary phase prepared via the conventional manner, the click lysine exchanger demonstrated shorter retention time and better ion separation characteristics under the same chromatographic conditions, which is a great advantage for rapid separation and analysis of inorganic ions.

  4. Carbonate and Bicarbonate Ion Transport in Alkaline Anion Exchange Membranes (United States)


    Bicarbonate Ion Transport in Alk Block 13: Supplementary Note © 2013 . Published in Journal of the Electrochemical Society , Vol. Ed. 0 160, (9) (2013...for public release; distribution is unlimited. ... 60325.7-CH-II F994 Journal of The Electrochemical Society , 160 (9) F994-F999 (2013) 0013-4651/2013...160(9)/F994/6/$31.00 © The Electrochemical Society Carbonate and Bicarbonate Ion Transport in Alkaline Anion Exchange Membranes Andrew M. Kiss,a

  5. Preparation of a Cation Exchanger from Cork Waste: Thermodynamic Study of the Ion Exchange Processes

    Institute of Scientific and Technical Information of China (English)


    An ion exchanger was prepared by sulfonation of cork-waste chars. The exchange properties of the resultant materialwere characterized using Na+, Ca2+ or Fe3+ aqueous solutions, The content of metal ions in the solutions weredetermined by atomic absorption spectrometry. On the basis of the results obtained, the chemical equilibrium andits thermodynamic aspects related to the ion exchange process were studied. It was found that equilibrium constantK varies by the order: Na+<Ca2+<Fe3+, its value increasing with increasing temperature, and that △H°>0 and△S°>0, with -△G° following the sequence: Ca2+>Na+>Fe3+,

  6. Synthesis, characterization and ion exchange properties of zirconium(IV) tungstoiodophosphate, a new cation exchanger

    Indian Academy of Sciences (India)

    Weqar Ahmad Siddiqui; Shakeel Ahmad Khan


    Zirconium(IV) tungstoiodophosphate has been synthesized under a variety of conditions. The most chemically and thermally stable sample is prepared by adding a mixture of aqueous solutions of 0.5 mol L-1 sodium tungstate, potassium iodate and 1 mol L-1 orthophosphoric acid to aqueous solution of 0.1 mol L-1 zirconium(IV) oxychloride. Its ion exchange capacity for Na+ and K+ was found to be 2.20 and 2.35 meq g-1 dry exchanger, respectively. The material has been characterized on the basis of chemical composition, pH titration, Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis. The effect on the exchange capacity of drying the exchanger at different temperatures has been studied. The analytical importance of the material has been established by quantitative separation of Pb2+ from other metal ions.

  7. Stydy on the Model of Ion Exchange Kinetics

    Institute of Scientific and Technical Information of China (English)

    ChenFengrong; JiangZhixin


    In this paper, a macrokinetics model equation describing the characteristics of the solid-liquid mass transfer has been proposed.The qualitative analysis and experimental verification have been done for this mode equation.The model equation can explain the ion exchange process considerably well.


    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...

  9. Thermal Analysis for Ion-Exchange Column System

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Si Y.; King, William D.


    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.

  10. Ion-exchange selectivity of diclofenac, ibuprofen, ketoprofen, and naproxen in ureolyzed human urine. (United States)

    Landry, Kelly A; Sun, Peizhe; Huang, Ching-Hua; Boyer, Treavor H


    This research advances the knowledge of ion-exchange of four non-steroidal anti-inflammatory drugs (NSAIDs) - diclofenac (DCF), ibuprofen (IBP), ketoprofen (KTP), and naproxen (NPX) - and one analgesic drug-paracetamol (PCM) - by strong-base anion exchange resin (AER) in synthetic ureolyzed urine. Freundlich, Langmuir, Dubinin-Astakhov, and Dubinin-Radushkevich isotherm models were fit to experimental equilibrium data using nonlinear least squares method. Favorable ion-exchange was observed for DCF, KTP, and NPX, whereas unfavorable ion-exchange was observed for IBP and PCM. The ion-exchange selectivity of the AER was enhanced by van der Waals interactions between the pharmaceutical and AER as well as the hydrophobicity of the pharmaceutical. For instance, the high selectivity of the AER for DCF was due to the combination of Coulombic interactions between quaternary ammonium functional group of resin and carboxylate functional group of DCF, van der Waals interactions between polystyrene resin matrix and benzene rings of DCF, and possibly hydrogen bonding between dimethylethanol amine functional group side chain and carboxylate and amine functional groups of DCF. Based on analysis of covariance, the presence of multiple pharmaceuticals did not have a significant effect on ion-exchange removal when the NSAIDs were combined in solution. The AER reached saturation of the pharmaceuticals in a continuous-flow column at varying bed volumes following a decreasing order of DCF > NPX ≈ KTP > IBP. Complete regeneration of the column was achieved using a 5% (m/m) NaCl, equal-volume water-methanol solution. Results from multiple treatment and regeneration cycles provide insight into the practical application of pharmaceutical ion-exchange in ureolyzed urine using AER.

  11. A new hybrid ion exchanger: Effect of system parameters on the adsorption of vanadium (V)

    Energy Technology Data Exchange (ETDEWEB)

    Yeom, Bong-Yeol [Nonwovens Cooperative Research Center, College of Textiles, North Carolina State University, Raleigh, NC 27695-8301 (United States); Lee, Chang-Soo [School of Applied Chemistry and Biological Engineering, College of Engineering, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Hwang, Taek-Sung, E-mail: [School of Applied Chemistry and Biological Engineering, College of Engineering, Chungnam National University, Daejeon 305-764 (Korea, Republic of)


    The hybrid ion exchanger consisted of PONF-g-GMA anion fibrous exchanger and IRA-96 bead-type anion exchanger was developed by combining different types of layers with hot-melt adhesive. Its ion exchange capacity and the pressure drop with flow rate of water were measured and the adsorption of vanadium (V) ions on the hybrid ion exchanger was evaluated with various process parameters such as pH, initial concentration, and temperature. It was observed that the adsorption kinetics of vanadium (V) ions on the hybrid ion exchanger could be analyzed with pseudo-second-order model.

  12. Photowritten gratings in ion-exchanged glass waveguides. (United States)

    Roman, J E; Winick, K A


    The fabrication of an ion-exchanged waveguide beam deflector containing a photowritten grating is described. The planar waveguide was fabricated by thermal K(+) exchange in a borosilicate glass. The grating was written by photobleaching an absorption defect centered at 330 am, which was created by gamma-ray irradiation of the glass. The bleaching was accomplished with the 351-nm line from an argon laser. The device achieved 35% deflection efficiency at 633 nm, which corresponded to a grating with a photoinduced index change of 2.6 x 10(-5). This is to our knowledge the first demonstration of an ion-exchanged glass waveguide device containing a permanent photowritten grating.

  13. Controlled charge exchange between alkaline earth metals and their ions (United States)

    Gacesa, Marko; Côté, Robin


    We theoretically investigate the prospects of realizing controlled charge exchange via magnetic Feshbach resonances in cold and ultracold collisions of atoms and ions. In particular, we focus on near-resonant charge exchange in heteroisotopic combinations of alkaline earth metals, such as 9Be++10 Be9 Be+10Be+ , which exhibit favorable electronic and hyperfine structure. The quantum scattering calculations are performed for a range of initial states and experimentally attainable magnetic fields in standard coupled-channel Feshbach projection formalism, where higher-order corrections such as the mass-polarization term are explicitely included. In addition, we predict a number of magnetic Feshbach resonances for different heteronuclear isotopic combinations of the listed and related alkaline earth elements. Our results imply that near-resonant charge-exchange could be used to realize atom-ion quantum gates, as well as controlled charge transfer in optically trapped cold quantum gases. This work is partially supported by ARO.

  14. Effect of the type of ion exchange membrane on performance, ion transport, and pH in biocatalyzed electrolysis of wastewater

    NARCIS (Netherlands)

    Rozendal, R.A.; Sleutels, T.H.J.A.; Hamelers, H.V.M.; Buisman, C.J.N.


    Previous studies have shown that the application of cation exchange membranes (CEMs) in bioelectrochemical systems running on wastewater can cause operational problems. In this paper the effect of alternative types of ion exchange membrane is studied in biocatalyzed electrolysis cells. Four types of

  15. Effect of the type of ion exchange membrane on performance, ion transport, and pH in biocatalyzed electrolysis of wastewater

    NARCIS (Netherlands)

    Rozendal, R.A.; Sleutels, T.H.J.A.; Hamelers, H.V.M.; Buisman, C.J.N.


    Previous studies have shown that the application of cation exchange membranes (CEMs) in bioelectrochemical systems running on wastewater can cause operational problems. In this paper the effect of alternative types of ion exchange membrane is studied in biocatalyzed electrolysis cells. Four types of

  16. 离子交换型缓蚀填料在防腐蚀涂层中的应用Ⅰ阳离子交换型填料%Application of Ion-exchange Compounds as Corrosion Inhibiting Pigments to Organic Anticorrosion Coatings Ⅰ Cation-exchange Pigments

    Institute of Scientific and Technical Information of China (English)

    吴俊升; 肖葵; 李欣荣; 董超芳; 李晓刚


    铬酸盐等重金属类缓蚀性颜填料会对环境造成严重的污染,未来该类有害物质在防腐蚀涂层中的应用将被禁止。新型的离子交换型填料因其具有可同时释放缓蚀性离子和吸附固定侵蚀性离子(H+、Cl-、SO24-等)的双重功效,被认为是替代传统重金属类颜填料的理想材料。本文对Zn2+、Ce3+、Ca2+等缓蚀性阳离子改性膨润土、氧化硅、分子筛等新型离子交换型缓蚀填料在有机防腐蚀涂层中的应用进行了综述。%It is well documented that chromate pigments and other heavy metal compounds must be eliminated from organic anticorrosion coatings due to their toxic nature and carcinogenic effects in the future. The novel ion-exchange pigments can play a double role of absorbing the harmful ions such as H+ ,C1- ,SO24- and releasing the inhibiting ions on contact with aggressive electrolyte invading the coating. The released inhibitors can provide active corrosion protection to the defects in the coating and substrate, on the other hand, the uptake of harmful ions decreases the aggressiveness of the corrosive medium, and thereby reduces the rate of ecorrosion processes. Therefore, such new inhibiting compounds have been developed as the potential alternate materials of the traditional toxic pigments, and have attracted a lot of attention. In this paper, the application of ion-exchange pigments, such as Ce3+ , Znz+ cation-exchanged bentonite, Ca2+ cation-exchanged silica and MoO22+ cation-exchanged zeolite, to organic anticorrosion coatings is reviewed.

  17. Systematics of heavy-ion charge-exchange straggling (United States)

    Sigmund, P.; Schinner, A.


    The dependence of heavy-ion charge-exchange straggling on the beam energy has been studied theoretically for several ion-target combinations. Our previous work addressed ions up to krypton, while the present study focuses on heavier ions, especially uranium. Particular attention has been paid to a multiple-peak structure which has been predicted theoretically in our previous work. For high-Z1 and high-Z2 systems, exemplified by U in Au, we identify three maxima in the energy dependence of charge-exchange straggling, while the overall magnitude is comparable with that of collisional straggling. Conversely, for U in C, charge-exchange straggling dominates, but only two peaks lie in the energy range where we presently are able to produce credible predictions. For U-Al we find good agreement with experiment in the energy range around the high-energy maximum. The position of the high-energy peak - which is related to processes in the projectile K shell - is found to scale as Z12 , in contrast to the semi-empirical Z13/2 dependence proposed by Yang et al. Measurements for heavy ions in heavy targets are suggested in order to reconcile a major discrepancy between the present calculations and the frequently-used formula by Yang et al.

  18. Application study on ion exchange chromatography in human serum albumin manufacture process%离子交换层析在人血白蛋白生产中的应用研究

    Institute of Scientific and Technical Information of China (English)

    井金荣; 周安; 范加金; 菅长永; 冯卫国; 臧恒昌


    Objective To study ion exchange chromatography application in human serum albumin (HSA) manufacture process.Methods The factor Ⅳ supernatant separated by cold ethanol fractionation was dealcoholized by ultrafiltration and purifed by ion exchange chromatography.The column gel was selected,and sample pH,conductivity and sample load for ion exchange chromatography were optimized.The purity of HSA intermediates and final products were detected by high performance liquid chromatography (HPLC).Results Capto DEAE gel was used for ion exchange chromatography,and the optimized chromatographic conditions were sample pH6.9,conductivity 5 mS/cm and sample load ≤1.2 g protein/ml gel.HPLC results showed that the purity of HSA intermediates prepared by optimized cold ethanol fractionation were 99.44%-1.00.00%,and the purity of HSA final products prepared by optimized cold ethanol fractionation (97.77%) was higher than that by traditional cold ethanol fractionation (93.82%).Conclusion Ion exchange chromatography can be applied in HSA manufacture process.%目的 研究离子交换层析在人血白蛋白生产中的应用.方法 将采用低温乙醇分离工艺分离的组分Ⅳ上清液超滤脱醇后,采用离子交换层析进行纯化.筛选层析用凝胶并优化离子交换层析的样品pH、电导率和上样量.同时采用高效液相色谱检测人血白蛋白中间品和成品的纯度.结果 选用Capto DEAE凝胶作为层析用介质,最适层析条件为:样品pH值6.9、电导率5.0 mS/cm、上样量≤1.2g蛋白/ml凝胶.高效液相色谱检测显示,优化低温乙醇工艺制备的人血白蛋白中间品纯度可达99.44%~100.00%,而且优化低温乙醇工艺制备的人血白蛋白成品纯度(97.77%)高于传统低温乙醇工艺(93.82%).结论 该离子交换层析工艺可在人血白蛋白生产中应用.

  19. Separation of americium from curium by oxidation and ion exchange. (United States)

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


    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.

  20. Studies on the solid-state ion exchange of nickel ions into zeolites using DRS technique (United States)

    Zanjanchi, M. A.; Ebrahimian, A.


    The coordination of Ni 2+ ions in the dehydrated nickel-exchanged zeolites was investigated from the analysis of diffuse reflectance spectra. Solid-state ion exchange method was used to prepare nickel-containing mordenite, Y, L and mazzite zeolites. In the dehydrated mordenite and zeolite Y, nickel cations are presented in both forms of tetrahedral and distorted tetrahedral symmetries. The relative amount of tetrahedral and distorted tetrahedral nickel species are related to the heating temperature and heating time used for calcinations. In the dehydrated zeolite L and mazzite, Ni 2+ ions are mainly in the distorted octahedral symmetries.

  1. Separation of seven arsenic species by ion-pair and ion-exchange high performance liquid chromatography

    DEFF Research Database (Denmark)

    Larsen, Erik Huusfeldt; Hansen, Sven Hedegaard


    Arsenite, arsenate, monomethylarsonate, dimethylarsinate, arsenobetaine, arsenocholine and the tetramethylarsonium ion were subjected to ion-exchange and ion-pair reversed phase HPLC. The ion exchange method was superior in selectivity and time of analysis for the arsenic anions. The ammonium ions...... used for the ion-pair method only resulted in separation of some of the anionic arsenic compounds. Flame atomic absorption spectrometry was used for on-line arsenic-specific detection....

  2. Porous metal oxide microspheres from ion exchange resin (United States)

    Picart, S.; Parant, P.; Caisso, M.; Remy, E.; Mokhtari, H.; Jobelin, I.; Bayle, J. P.; Martin, C. L.; Blanchart, P.; Ayral, A.; Delahaye, T.


    This study is devoted to the synthesis and the characterization of porous metal oxide microsphere from metal loaded ion exchange resin. Their application concerns the fabrication of uranium-americium oxide pellets using the powder-free process called Calcined Resin Microsphere Pelletization (CRMP). Those mixed oxide ceramics are one of the materials envisaged for americium transmutation in sodium fast neutron reactors. The advantage of such microsphere precursor compared to classical oxide powder is the diminution of the risk of fine dissemination which can be critical for the handling of highly radioactive powders such as americium based oxides and the improvement of flowability for the filling of compaction chamber. Those millimetric oxide microspheres incorporating uranium and americium were synthesized and characterizations showed a very porous microstructure very brittle in nature which occurred to be adapted to shaping by compaction. Studies allowed to determine an optimal heat treatment with calcination temperature comprised between 700-800 °C and temperature rate lower than 2 °C/min. Oxide Precursors were die-pressed into pellets and then sintered under air to form regular ceramic pellets of 95% of theoretical density (TD) and of homogeneous microstructure. This study validated thus the scientific feasibility of the CRMP process to prepare bearing americium target in a powder free manner.

  3. Ion-exchange chromatography for the characterization of biopharmaceuticals. (United States)

    Fekete, Szabolcs; Beck, Alain; Veuthey, Jean-Luc; Guillarme, Davy


    Ion-exchange chromatography (IEX) is a historical technique widely used for the detailed characterization of therapeutic proteins and can be considered as a reference and powerful technique for the qualitative and quantitative evaluation of charge heterogeneity. The goal of this review is to provide an overview of theoretical and practical aspects of modern IEX applied for the characterization of therapeutic proteins including monoclonal antibodies (Mabs) and antibody drug conjugates (ADCs). The section on method development describes how to select a suitable stationary phase chemistry and dimensions, the mobile phase conditions (pH, nature and concentration of salt), as well as the temperature and flow rate, considering proteins isoelectric point (pI). In addition, both salt-gradient and pH-gradient approaches were critically reviewed and benefits as well as limitations of these two strategies were provided. Finally, several applications, mostly from pharmaceutical industries, illustrate the potential of IEX for the characterization of charge variants of various types of biopharmaceutical products.

  4. Desalination of Saline Sludges Using Ion-Exchange Column with Zeolite

    Directory of Open Access Journals (Sweden)

    Abdel E. Ghaly


    Full Text Available A flushing process followed by a zeolite based ion-exchange process were developed for the treatment of saline sludges from oil and gas exploration sites. The particle size distribution of sludge sample indicated the presence of very fine sand and clay. The electrical conductivity of the sludge was 42.2 dS m-1 indicating very saline sludge and the Cation Exchange Capacity (CEC was 40 cmoL kg-1 which was very suitable for ion-exchange process. A 500 g sample of saline sludge (containing CaCl2:MgCl2:NaCl ratio as 1:1.16:36.61 was washed using demineralized water in a mixed reactor and the sludge was allowed to settle for 36 h. The optimal number of washes was determined to be two washes with an overall salt removal efficiency of 94.47%. The treated sludge contained 515 mg salt kg-1 sludge (or 0.05% w w-1 and was suitable for agricultural application. The washwater was passed through a Mountain Stronach zeolite (chabazite based ion-exchange column for salt reduction. The sodium salt removal efficiency was 75.34%. This was increased to 99.79% when using two ion-exchange columns. The Ca and Mg ions were under regulatory limits and required no further treatment. The final salt concentration in the wash water was 314.0 mg L-1 which was below the limits established by the Canadian Guidelines. For complete removal of total salts, a series of ion-exchange columns with different zeolites (for removal of NaCl, MgCl2 and CaCl2 will be required.

  5. Charge Exchange Effect on Space-Charge-Limited Current Densities in Ion Diode

    Institute of Scientific and Technical Information of China (English)



    The article theoretically studied the charge-exchange effects on space charge limited electron and ion current densities of non-relativistic one-dimensional slab ion diode, and compared with those of without charge exchange.

  6. Trends in Effective Diffusion Coefficients for Ion-Exchange Strengthening of Soda-Lime-Silicate Glasses

    Directory of Open Access Journals (Sweden)

    Stefan Karlsson


    Full Text Available Monovalent cations enable efficient ion-exchange processes due to their high mobility in silicate glasses. Numerous properties can be modified in this way, e.g., mechanical, optical, electrical, or chemical performance. In particular, alkali cation exchange has received significant attention, primarily with respect to introducing compressive stress into the surface region of a glass, which increases mechanical durability. However, most of the present applications rely on specifically tailored matrix compositions in which the cation mobility is enhanced. This largely excludes the major area of soda-lime-silicates (SLS such as are commodity in almost all large-scale applications of glasses. Basic understanding of the relations between structural parameters and the effective diffusion coefficients may help to improve ion-exchanged SLS glass products, on the one hand in terms of obtainable strength and on the other in terms of cost. In the present paper, we discuss the trends in the effective diffusion coefficients when exchanging Na+ for various monovalent cations (K+, Cu+, Ag+, Rb+, and Cs+ by drawing relations to physicochemical properties. Correlations of effective diffusion coefficients were found for the bond dissociation energy and the electronic cation polarizability, indicating that localization and rupture of bonds are of importance for the ion-exchange rate.

  7. Trends in Effective Diffusion Coefficients for Ion-exchange Strengthening of Soda Lime Silicate Glasses (United States)

    Karlsson, Stefan; Wondraczek, Lothar; Ali, Sharafat; Jonson, Bo


    Monovalent cations enable efficient ion exchange processes due to their high mobility in silicate glasses. Numerous properties can be modified in this way, e.g., mechanical, optical, electrical or chemical performance. In particular, alkali cation exchange has received significant attention, primarily with respect to introducing compressive stress into the surface region of a glass, which increases mechanical durability. However, most of the present applications rely on specifically tailored matrix compositions in which the cation mobility is enhanced. This largely excludes the major area of soda lime silicates (SLS) such as are commodity in almost all large-scale applications of glasses. Basic understanding of the relations between structural parameters and the effective diffusion coefficients may help to improve ion-exchanged SLS glass products, on the one hand in terms of obtainable strength and on the other in terms of cost. In the present paper, we discuss the trends in the effective diffusion coefficients when exchanging Na+ for various monovalent cations (K+, Cu+, Ag+, Rb+ and Cs+) by drawing relations to physico-chemical properties. Correlations of effective diffusion coefficients were found for the bond dissociation energy and the electronic cation polarizability, indicating that localization and rupture of bonds are of importance for the ion exchange rate.

  8. Buried waveguides for passive integrated optics by Cs+ -ion-exchange (United States)

    Ross, L.; Lilienhof, H.-J.; Holscher, H. W.


    Cs4-ion-exchange in glass is compared with the commonly used K+-, Ag+- and T1+-ion-exchange in glass in the process of waveguide fabrication. It will be shown that the Cs4-ion-exchange in the special substrate glass BGG21 represents an alternative method. As in the case of Ag+ AND T14 it is possible to fabricate buried waveguides by a double ion-exchange. The field-assisted ion-exchange is preferred due to the low CO+-ion mobility.

  9. Ion exchange at the critical point of solution. (United States)

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


    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.

  10. Thermal annealing of K(+)-Na(+) ion-exchanged waveguides. (United States)

    Giorgetti, E; Grando, D; Palchetti, L; Sottini, S


    The process of thermal annealing of K(+)(-)Na(+) ion-exchanged waveguides in soda lime glass is characterized and compared with a simple theoretical model. The discrepancies between theory and experiments in the case of initially thick guides disappear if the existence of a stress-induced contribution to the refractive index is assumed that is not proportional to the concentration of the doping ions. The results obtained for initially thin guides are exploited for the design of annealed single-mode channel waveguides: 0.4-dB coupling losses with commercial single-mode fibers at lambda = 1.321 microm were measured.

  11. Diffusion kinetics of the ion exchange of benzocaine on sulfocationites (United States)

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


    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.

  12. Hybrid metallic ion-exchanged waveguides for SPR biological sensing (United States)

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


    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.

  13. Determination of ammonium ion in biological nitrification-denitrification process water by ion exclusion chromatography with ion exchange enhancement of conductivity detection.


    田中, 一彦; 黒川, 利一; 中島, 良三; Fritz, James S.


    Ammonium ion in biological nitrification-denitrification process with batchwise treatment was determined by ion exclusion chromatography using water as an eluent with ion exchange enhancement of conductivity. Ammonium ion was selectively separated by ion exclusion from alkali metal and alkaline earth metal cations. The detection sensitivity of the ammonium ion was improved about 11-fold with two ion exchange enhancement columns inserted in series between the separation column packed with OH--...

  14. Removal of chromium from electroplating industry effluents by ion exchange resins. (United States)

    Cavaco, Sofia A; Fernandes, Sandra; Quina, Margarida M; Ferreira, Licínio M


    Effluent discharged from the chromium electroplating industry contains a large number of metals, including chromium, copper, nickel, zinc, manganese and lead. The ion exchange process is an alternative technique for application in the treatment of industrial wastewater containing heavy metals and indeed it has proven to be very promising in the removal and recovery of valuable species. The main objective of the present work is to evaluate the performance of commercial ion exchange resins for removing chromium trivalent from industrial effluents, and for this purpose two resins were tested: a chelating exchange resin (Diaion CR11) and a weak cationic resin (Amberlite IRC86). In order to evaluate the sorption capacity of the resins some equilibrium experiments were carried out, being the temperature and pH the main variables considered. The chromium solutions employed in the experiments were synthetic solutions and industrial effluents. In addition, a transient test was also performed as an attempt to understand the kinetic behaviour of the process.

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

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, J.B.


    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.

  16. Dimerisation of isobutene on acidic ion-exchange resins


    Honkela, Maija


    Dimerisation of isobutene produces diisobutenes that can be hydrogenated to isooctane (2,2,4-trimethyl pentane). Isooctane can be used as a high octane gasoline component. The aim of this work was to study the selective production of diisobutenes through the dimerisation of isobutene on ion-exchange resin catalysts and to construct kinetic models for the reactions in the system for reactor design purposes. High selectivities for diisobutenes were obtained in the presence of polar componen...

  17. Pyrolysis of spent ion exchange resins; Die Pyrolyse von verbrauchten Ionentauscherharzen

    Energy Technology Data Exchange (ETDEWEB)

    Braehler, Georg; Slametschka, Rainer [NUKEM Technologies GmbH, Alzenau (Germany)


    Ion exchangers are employed in all nuclear power plants with water loops to remove radionuclides from the primary coolant. Cation and anion exchangers are used as coarse-grained spherical resins in pressurized water reactors and as finely ground powder resins in boiling water reactors. In new plants there is a trend to exploit all possibilities of avoiding contaminated liquids and, should solutions occur nevertheless, clean them by ion exchange to such an extent that they can be disposed of as non-radioactive waste. This means less use of evaporator facilities or even giving them up altogether. Regeneration, which is possible in principle, is hardly employed at all. As a rule, ion exchangers consist of cross-linked polystyrene. As no use is made of regeneration in nuclear power plants, unlike conventional technology, the material must be disposed of as radioactive waste. In this connection, it is important to bear in mind that spent ion exchangers are too moist for direct disposal and are made up of inorganic matter. Consequently, a process is needed which reduces volume, produces an inert or mineralized product, works at temperatures not exceeding approx. 600 C, and can be run in a simple plant. NUKEM further developed a pyrolysis technique known from other technical applications. These ion exchangers can be decomposed by pyrolysis very effectively; the product is inert and chemically resistant. No additives are needed. The entire radioactivity inventory remains in the pyrolysate. The pyrolysate is a flowable solid. This makes it easy to handle and allows it to be compacted or cemented, depending on interim and repository storage conditions and on the activity inventory. (orig.)

  18. Ion exchange properties of titanic fiber of layered structure

    Energy Technology Data Exchange (ETDEWEB)

    Fujiki, Yoshinori; Komatsu, Yu; Sasaki, Takayoshi


    Usually, titanic acid is produced by hydrolyzing titanium tetrachloride, titanium sulfate or titanium alkoxide and is obtained in the form of precipitate in an amorphous gel state. The present authors have synthesized two types of titanic fibers of a layered crystaline structure to provide new ion exchangers. Three synthetic techniques, namely, flux process, annealing baking process and melt process, have been developed. This report deals with the structure and properties of these materials. In the flux process, a mixture of TiO/sub 2/, K/sub 2/CO/sub 3/ and K/sub 2/MoO/sub 4/ (flux) is melted at 1150 deg C and annealed at about 950 deg C to provide a K/sub 2/Ti/sub 4/O/sub 3/ fiber of a layered structure, which is subsequently converted into H/sub 2/Ti/sub 4/O/sub 9/ center dot nH/sub 2/O fiber. In the melt process, a mixture of materials is heate up to 1100 deg C to produce molten K/sub 2/Ti/sub 2/O/sub 5/, which is quenched to form K/sub 2/Ti/sub 2/O/sub 5/ fiber of a layered structure. Then it is converted into H/sub 2/Ti/sub 2/O/sub 5/ center dot nH/sub 2/O fiber. The annealing baking process provides K/sub 2/Ti/sub 4/O/sub 9/, which is converted into K/sub 2/Ti/sub 2/O/sub 5/ fiber. In this report, the crystal structure of H/sub 2/Ti/sub 4/O/sub 9/ center dot nH/sub 2/O is discussed and the ion exchanging properties are analized. Examination is made on the ion exchanging reactions involving potassium, alkali metal ions, alkaline earth metal ions and divalent transition metal ions. Various ion exchangers, including the present ones, are compared in terms of the partition coefficient and separation factor. (Nogami, K.).


    Institute of Scientific and Technical Information of China (English)

    WU Chinyung; YANG Chaoshiung; YANG Chong


    The present article deals with the exchange process of bivalent metal ions, such as Zn2 +, Cd2 + and Hg2+, etc., taken up by non-crosslinked carboxylated polypropylene (CPP) resin. The control factor of the exchange rate deduced from the kinetic data is governed basically by the chemical reaction rather than the mass transfer effect particle diffusion and/or liquid film diffusion. In solution, all the graft chains in the outer shell ofa CPP resin could form a "quasi-macromolecular solution" domain. This opinion further demonstrates the structural pattern of CPP resin proposed in earlier paper[1].

  20. The Effects of Sulfonated Poly(ether ether ketone Ion Exchange Preparation Conditions on Membrane Properties

    Directory of Open Access Journals (Sweden)

    Rebecca S. L. Yee


    Full Text Available A low cost cation exchange membrane to be used in a specific bioelectrochemical system has been developed using poly(ether ether ketone (PEEK. This material is presented as an alternative to current commercial ion exchange membranes that have been primarily designed for fuel cell applications. To increase the hydrophilicity and ion transport of the PEEK material, charged groups are introduced through sulfonation. The effect of sulfonation and casting conditions on membrane performance has been systematically determined by producing a series of membranes synthesized over an array of reaction and casting conditions. Optimal reaction and casting conditions for producing SPEEK ion exchange membranes with appropriate performance characteristics have been established by this uniquely systematic experimental series. Membrane materials were characterized by ion exchange capacity, water uptake, swelling, potential difference and NMR analysis. Testing this extensive membranes series established that the most appropriate sulfonation conditions were 60 °C for 6 h. For mechanical stability and ease of handling, SPEEK membranes cast from solvent casting concentrations of 15%–25% with a resulting thickness of 30–50 µm were also found to be most suitable from the series of tested casting conditions. Drying conditions did not have any apparent impact on the measured parameters in this study. The conductivity of SPEEK membranes was found to be in the range of 10−3 S cm−1, which is suitable for use as a low cost membrane in the intended bioelectrochemical systems.

  1. Ag clustering investigation in laser irradiated ion-exchanged glasses by optical and vibrational spectroscopy (United States)

    Trave, E.; Cattaruzza, E.; Gonella, F.; Calvelli, P.; Quaranta, A.; Rahman, A.; Mariotto, G.


    Ion exchange process is widely used to dope silicate glass layers with silver for several applications, ranging from light waveguide to nanostructured composite glass fabrication. The silver-doped structure and its physical properties depend on the preparation parameters as well as on subsequent treatments. In particular, laser irradiation of the ion exchanged glasses has been demonstrated to be an effective tool to control cluster size and size distribution. Nevertheless, a complete comprehension of the basic phenomena and a systematic characterization of these systems are still lacking. In this paper, an extended optical characterization is presented for soda-lime glass slides, doped with silver by Ag+-Na+ ion exchange, thermally treated and irradiated with a Nd:YAG laser beam at different wavelengths, and for different energy density. The samples were characterized by various spectroscopic techniques, namely, optical absorption, photoluminescence and micro-Raman analysis. The availability of all these characterization techniques allowed pointing out a suitable scenario for the Ag clustering evolution as a function of the ion exchange, annealing and laser irradiation parameters.

  2. The load and release characteristics on a strong cationic ion-exchange fiber: kinetics, thermodynamics, and influences. (United States)

    Yuan, Jing; Gao, Yanan; Wang, Xinyu; Liu, Hongzhuo; Che, Xin; Xu, Lu; Yang, Yang; Wang, Qifang; Wang, Yan; Li, Sanming


    Ion-exchange fibers were different from conventional ion-exchange resins in their non-cross-linked structure. The exchange was located on the surface of the framework, and the transport resistance reduced significantly, which might mean that the exchange is controlled by an ionic reaction instead of diffusion. Therefore, this work aimed to investigate the load and release characteristics of five model drugs with the strong cationic ion-exchange fiber ZB-1. Drugs were loaded using a batch process and released in United States Pharmacopoeia (USP) dissolution apparatus 2. Opposing exchange kinetics, suitable for the special structure of the fiber, were developed for describing the exchange process with the help of thermodynamics, which illustrated that the load was controlled by an ionic reaction. The molecular weight was the most important factor to influence the drug load and release rate. Strong alkalinity and rings in the molecular structures made the affinity between the drug and fiber strong, while logP did not cause any profound differences. The drug-fiber complexes exhibited sustained release. Different kinds and concentrations of counter ions or different amounts of drug-fiber complexes in the release medium affected the release behavior, while the pH value was independent of it. The groundwork for in-depth exploration and further application of ion-exchange fibers has been laid.

  3. Negative Joule Heating in Ion-Exchange Membranes

    CERN Document Server

    Biesheuvel, P M; Hamelers, H V M


    In ion-exchange membrane processes, ions and water flow under the influence of gradients in hydrostatic pressure, ion chemical potential, and electrical potential (voltage), leading to solvent flow, ionic fluxes and ionic current. At the outer surfaces of the membranes, electrical double layers (EDLs) are formed (Donnan layers). When a current flows through the membrane, we argue that besides the positive Joule heating in the bulk of the membrane and in the electrolyte outside the membrane, there is also negative Joule heating in one of the EDLs. We define Joule heating as the inner product of the two vectors current and field strength. Also when fluid flows through a charged membrane, at one side of the membrane there is pressure-related cooling, due to the osmotic and hydrostatic pressure differences across the EDLs.

  4. Hydrous Tantalum Phosphates for Ion Exchange Purposes: A Systematic Study

    Directory of Open Access Journals (Sweden)

    M.L.C.P.da Silva


    Full Text Available This work describes two methods of preparation of hydrous tantalum phosphates and their characterization as ion exchangers. The hydrous metallic phosphate compounds were chemically and physically characterized by thermal gravimetric analysis, X-ray diffractometry and surface area measurements. By the first method, tantalum phosphate was prepared by alkaline fusion of Ta2O5 with an excess of K2CO3, followed by lixiviation of the tantalate fusion product with hot water, and precipitation with diluted H3PO4. Preparation II was performed using metallic Ta dissolved in concentrated HF/HNO3 acidic mixture followed by hydrolysis of fluortantalic acid intermediary and precipitation with diluted H3PO4. Both freshly prepared materials (I and II were exaustively refluxed with concentrated H3PO4, in its boiling point temperature, resulting respectively in Ta2O5. 2.1 H2O, (IR and Ta2O5. 1.3 H2O, (IIR. Characterization of the prepared products have presented the following values: surface area of 108.27 ± 2.80; 220.14 ± 2.67; 117.07 ± 5.25 and 141.61 ± 0.27 m².g-1 respectively for I, IR, II and IIR. All these materials were amorphous. The ion exchange behavior for all four hydrous tantalum phosphates was studied using Na+, K+ and Ba+2 as the exchanged species. The values for typical ion exchange capacity were 1.64; 1.23; 1.47 and 1.01 miliequivalent.g-1, respectively for I, IR, II and IIR products.

  5. Chaotic behavior of ion exchange phenomena in polymer gel electrolytes through irradiated polymeric membrane

    Energy Technology Data Exchange (ETDEWEB)

    Rawat, Sangeeta; Saha, Barnamala; Prasad, Awadhesh [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Chandra, Amita, E-mail: [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India)


    A desktop experiment has been done to show the nonlinearity in the I–V characteristics of an ion conducting electrochemical micro-system. Its chaotic dynamics is being reported for the first time which has been captured by an electronic circuit. Polyvinylidene fluoride-co-hexafluoropropene (PVdF-HFP) gel electrolyte comprising of a combination of plasticizers (ethylene carbonate and propylene carbonate) and salts have been prepared to study the exchange of ions through porous polyethylene terephthalate (PET) membranes. The nonlinearity of this system is due to the ion exchange of the polymer gel electrolytes (PGEs) through a porous membrane. The different regimes of spiking and non-spiking chaotic motions are being presented. The possible applications are highlighted. -- Highlights: ► For the first time, the nonlinear dynamics of an electrochemical micro-system has been reported. ► The nonlinearity generates due to the ion exchange of polymer gel electrolytes through irradiated polymeric membrane. ► The nonlinearity can be tailored by changing the pore size of irradiated membrane. ► Sprott's circuit has been modified to capture the phenomena of ion transport through membrane. ► Attractor formation and Lyapunov exponent confirms the chaotic behavior of presently investigated system.

  6. Binary ion exchange of metal ions in Y and X zeolites

    Directory of Open Access Journals (Sweden)

    M.A.S.D. Barros


    Full Text Available The ion exchange of Na for Cr/K, Cr/Mg and Cr/Ca in Y and X zeolites was studied using breakthrough curves. It was observed that Cr3+ ions were able to remove some competitive ions that had already been exchanged at the zeolitic sites, producing a sequential ion exchange. Some mass transfer parameters such as length of unused bed, overall mass transfer coefficient, operational ratio and dimensionless variance were studied. Chromium uptake was influenced much more by the competing ion in the NaX zeolite columns. The dimensionless variance indicated that Cr/K solution produced a greater axial dispersion than the Cr/Mg and Cr/Ca systems, probably due to some interaction between Cr3+ and K+ ions. The order of dynamic selectivity, provided by the cation uptake, was Cr3+ > Ca2+, Cr3+ > Mg2+ and Cr3+ > K+ for NaY zeolite and Ca2+ ~Cr3+, Mg2+ > Cr3+ and Cr3+ > K+ for NaX zeolite. Due to the more favorable mass transfer parameters and higher affinity for Cr3+, it was concluded that NaY zeolite was more efficient at chromium uptake in competitive systems.


    Institute of Scientific and Technical Information of China (English)

    TAOZuyi; WANGChangshou


    The general procedure based on the potentiometric titration has developed.According to the procedure,the rational equilibrium constants of the ion exchange reactions RH/Na,RH/Ca,RH/Sr,RH/Ba for the weak acid cation exchange resin D725 and ROH/Cl for the weak base anion exchange resin D705 have been determined.

  8. Structural Insight into the Ion-Exchange Mechanism of the Sodium/Calcium Exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Jun; Li, Hua; Zeng, Weizhong; Sauer, David B.; Belmares, Ricardo; Jiang, Youxing (UTSMC)


    Sodium/calcium (Na{sup +}/Ca{sup 2+}) exchangers (NCX) are membrane transporters that play an essential role in maintaining the homeostasis of cytosolic Ca{sup 2+} for cell signaling. We demonstrated the Na{sup +}/Ca{sup 2+}-exchange function of an NCX from Methanococcus jannaschii (NCX{_}Mj) and report its 1.9 angstrom crystal structure in an outward-facing conformation. Containing 10 transmembrane helices, the two halves of NCX{_}Mj share a similar structure with opposite orientation. Four ion-binding sites cluster at the center of the protein: one specific for Ca{sup 2+} and three that likely bind Na{sup +}. Two passageways allow for Na{sup +} and Ca{sup 2+} access to the central ion-binding sites from the extracellular side. Based on the symmetry of NCX{_}Mj and its ability to catalyze bidirectional ion-exchange reactions, we propose a structure model for the inward-facing NCX{_}Mj.

  9. Ion exchange substrates for plant cultivation in extraterrestrial stations and space crafts (United States)

    Soldatov, Vladimir


    Ion exchange substrates Biona were specially designed at the Belarus Academy of Sciences for plants cultivation in spacecrafts and extraterrestrial stations. The first versions of such substrates have been successfully used in several space experiments and in a long-term experiment in which three soviet test-spacemen spent a full year in hermetic cabin imitating a lunar station cabin (1067-1968). In this experiment the life support system included a section with about one ton of the ion exchange substrate, which was used to grow ten vegetations of different green cultures used in the food of the test persons. Due to failure of a number of Soviet space experiments, decay of the Soviet Union and the following economic crisis the research in this field carried out in Belarus were re-directed to the needs of usual agriculture, such as adaptation of cell cultures, growing seedlings, rootage of cuttings etc. At present ion exchange substrate Biona are produced in limited amounts at the experimental production plant of the Institute of Physical Organic Chemistry and used in a number of agricultural enterprises. New advanced substrates and technologies for their production have been developed during that time. In the presentation scientific principles of preparation and functioning of ion exchange substrates as well as results of their application for cultivation different plants are described. The ion exchange substrate is a mixture of cation and anion exchangers saturated in a certain proportions with all ions of macro and micro elements. These chemically bound ions are not released to water and become available for plants in exchange to their root metabolites. The substrates contain about 5% mass of nutrient elements far exceeding any other nutrient media for plants. They allow generating 3-5 kg of green biomass per kilogram of substrate without adding any fertilizers; they are sterile by the way of production and can be sterilized by usual methods; allow regeneration

  10. Charge exchange spectroscopy as a fast ion diagnostic on TEXTORa) (United States)

    Delabie, E.; Jaspers, R. J. E.; von Hellermann, M. G.; Nielsen, S. K.; Marchuk, O.


    An upgraded charge exchange spectroscopy diagnostic has been taken into operation at the TEXTOR tokamak. The angles of the viewing lines with the toroidal magnetic field are close to the pitch angles at birth of fast ions injected by one of the neutral beam injectors. Using another neutral beam for active spectroscopy, injected counter the direction in which fast ions injected by the first beam are circulating, we can simultaneously measure a fast ion tail on the blue wing of the Dα spectrum while the beam emission spectrum is Doppler shifted to the red wing. An analysis combining the two parts of the spectrum offers possibilities to improve the accuracy of the absolute (fast) ion density profiles. Fast beam modulation or passive viewing lines cannot be used for background subtraction on this diagnostic setup and therefore the background has to be modeled and fitted to the data together with a spectral model for the slowing down feature. The analysis of the fast ion Dα spectrum obtained with the new diagnostic is discussed.

  11. Tungstate and Carbonate Ions Sorption Using Anion Exchangers AV-17-8 and Purolite A400

    Directory of Open Access Journals (Sweden)

    Chegrintsev S.


    Full Text Available The current paper shows the results of tungstate and carbonate ion sorption using strongly basic anion exchangers AV-17-8 and Purolite A400. It has been established that anion exchanger AV-17-8 in the chloride form with parameters of 168 g of tungstate ion and 157 g of carbonate ion per 1 kg of anion exchanger has the maximum capacity for the tungstate and carbonate ions.

  12. Advantages of ion-exchange chromatography for oligonucleotide analysis. (United States)

    Cook, Ken; Thayer, Jim


    The rapid development of therapeutic oligonucleotides (ONs) has created a need for in-depth characterization of ONs, beyond previous requirements. The natural migration to LC-MS requires the use of chromatography with MS-compatible eluents to introduce the large, highly charged biopolymers into the mass spectrometer. Most frequently this employs ion-pair reversed-phase liquid chromatography, which may leave gaps in the characterization, but these can be filled with the use of high-resolution ion-exchange chromatography. Several classes of isobaric isomers are among the impurities that will require further separation prior to MS analysis. This review shows how the use of ion exchange as an additional orthogonal analytical method can be used as standalone or interfaced with MS to achieve the highest possible analytical coverage in the characterization and quantification of impurities present in single- and double-stranded ON formulations. Some of these techniques have been in use for some time and the importance of others is just being recognized.

  13. Design of high efficiency fibers for ion exchange and heavy metal removal (United States)

    Dominguez, Lourdes

    Ion exchange materials coated on glass fiber substrates have a number of advantages over the conventional ion exchange beads. These include simplification of the overall synthesis including faster more efficient functionalization and elimination of toxic solvents. Other benefits include the ability to be fabricated in the form of felts, papers, or fabrics, improving media contact efficiency and enhancing both the rates of reaction and regeneration. In addition, physical and mechanical requirements of strength and dimensional stability are achieved by use of glass fiber substrates. Investigations were focused on design of: (1) polymeric cationic exchange fibers and their application for lead and mercury removal, (2) polymeric anionic exchange fibers and their application for arsenate removal, (3) enhancement of anionic fiber selectivity for monovalent ions over divalent ions through bulkier triaklylamine functional groups, and (4) polymeric mercaptyl fibers for the application of arsenite removal. The design and characterization of a cationic exchange fiber is described. Dynamic mode (breakthrough) experiments for calcium, lead, and mercury ion solutions are also presented. The second system consists of the preparation and characterization of anionic exchange fibers with equilibrium adsorption isotherms and dynamic mode kinetic experiments for arsenate removal. Modification of the resin with bulkier functional groups (trimethylamine, triethylamine, tripropylamine, tributylanmine), thereby effecting a change in the selectivity from divalent species to monovalent species, is considered in the separation of nitrates from sulfates. The ability of a thiol group to bind to the highly toxic arsenite ion (as is done in proteins and enzymes) provided the model used to chemically modify and characterize a polyvinyl alcohol mercaptyl fibrous system, coated on a fiberglass substrate, for the purpose of arsenite (As3+) removal from water. Physical/chemical aspects of naturally

  14. Ion Exchange and Solvent Extraction: Supramolecular Aspects of Solvent Exchange Volume 21

    Energy Technology Data Exchange (ETDEWEB)

    Gloe, Karsten [Technischen Universität Dresden; Tasker, Peter A [ORNL; Oshima, Tatsuya [University of Miyazaki; Watarai, Hitoshi [Institute for NanoScience Design at Osaka University; Nilsson, Mikael [University of California, Irvine


    Preface The theme of supramolecular chemistry (SC), entailing the organization of multiple species through noncovalent interactions, has permeated virtually all aspects of chemical endeavor over the past several decades. Given that the observed behavior of discrete molecular species depends upon their weak interactions with one another and with matrix components, one would have to conclude that SC must indeed form part of the fabric of chemistry itself. A vast literature now serves to categorize SC phenomena within a body of consistent terminology. The word supramolecular itself appears in the titles of dozens of books, several journals, and a dedicated encyclopedia. Not surprisingly, the theme of SC also permeates the field of solvent extraction (SX), inspiring the framework for this volume of Ion Exchange and Solvent Extraction. It is attempted in the six chapters of this volume to identify both how supramolecular behavior occurs and is studied in the context of SX and how SC is influencing the current direction of SX. Researchers and practitioners have long dealt with supramolecular interactions in SX. Indeed, the use of polar extractant molecules in nonpolar media virtually assures that aggregative interactions will dominate the solution behavior of SX. Analytical chemists working in the 1930s to the 1950s with simple mono- and bidentate chelating ligands as extractants noted that extraction of metal ions obeyed complicated mass-action equilibria involving complex stoichiometries. As chemists and engineers developed processes for nuclear and hydrometallurgical applications in the 1950s and 1960s, the preference for aliphatic diluents only enhanced the complexity and supramolecular nature of extraction chemistry. Use of physical techniques such as light scattering and vapor-pressure measurements together with various spectroscopic methods revealed organic-phase aggregates from well-defined dimers to small aggregates containing a few extractant molecules to large

  15. 离子交换型缓蚀填料在防腐蚀涂层中的应用Ⅱ阴离子交换型填料%Application of Ion-exchange Compounds as Corrosion Inhibiting Pigments to Organic Anticorrosion Coatings Ⅱ Anion-exchange Pigments

    Institute of Scientific and Technical Information of China (English)

    吴俊升; 肖葵; 李欣荣; 董超芳; 李晓刚


    铬酸盐等重金属类缓蚀性颜填料会对环境造成严重的污染,未来该类有害物质在防腐蚀涂层中的应用将被禁止.新型的离子交换型填料因其具有可同时释放缓蚀性离子和吸附固定侵蚀性离子(H+、Cl-、SO2-4等)的双重功效,被认为是替代传统重金属类颜填料的理想材料.本文对[V10O28]6-、MoO2-4等缓蚀性阴离子改性水滑石类层状新型离子交换型缓蚀填料在有机防腐蚀涂层中的应用进行综述.%It is well documented that chromate pigments and other heavy metal compounds must be eliminated from organic anticorrosion coatings due to their toxic nature and carcinogenic effects in the future. The novel ion-exchange pigments can play a double role of absorbing the harmful ions such as H+ , Cl- , SO2-4 and releasing the inhibiting ions on contact with aggressive electrolyte invading the coating. The released inhibitors can provide active corrosion protection to the defects in the coating and substrate. On the other hand, the uptake of harmful ions decreases the aggressiveness of the corrosive medium, and thereby reduces the rate of corrosion processes. Therefore, such new inhibiting compounds have been developed as the potential alternate materials of the traditional toxic pigments, and have attracted a lot of attention. In this paper, the application of anion-exchange pigments, such as [V10O28]6- , MoO2-4 exchanged hydrotalcite, in organic anticorrosion coatings is reviewed.

  16. Kinetic study of heavy metal ions removal by ion exchange in batch conical air spouted bed

    Directory of Open Access Journals (Sweden)

    T.M. Zewail


    Full Text Available Spouted bed contactor is a hybrid of fixed and fluidized bed contactors, which retains the advantages of each with good hydrodynamic conditions. The aim of the present study is to investigate the performance of a batch conical air spouted vessel for heavy metal removal by strong cation exchange resins (AMBERJET 1200 Na. The effect of various parameters such as type of heavy metal ions (Ni+2 and Pb+2, contact time, superficial air velocity and initial heavy metal ion concentration on % heavy metal ion removal has been investigated. It has been found that under optimum conditions 98% and 99% removal of Ni+2 and Pb+2 were achieved respectively. Several kinetic models were used to test the experimental data and to examine the controlling mechanism of the sorption process. The present results of Ni+2 and Pb+2 well fit pseudo second order kinetic model with a high correlation coefficient. Both film diffusion and intra-particle diffusion contribute to the ion exchange process. The present study revealed that spouted bed vessel may provide an effective alternative for conducting ion exchange reactions.


    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.; King, W.


    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. The modification of ion exchange heterogeneous catalysts for biodiesel synthesis (United States)

    Hartono, R.; Mulia, B.; Sahlan, M.; Utami, T. S.; Wijanarko, Anondho; Hermansyah, Heri


    Conventionally, biodiesel is produced by using the homogeneous catalyst which has difficulty in high cost of the separation process. The heterogeneous catalysts ion exchange resin by its Solid phase can make an easier separation process, able to be reactivated and used repeatedly. In this research, the heterogeneous catalyst from various source such as Lewatit macro porous resin, Amberlite gel resin and natural zeolite bayah was investigated their performance to produced biodiesel from used cooking oil. Initially, the preparation of the ion exchange process with variations in time, temperature, the concentration of HCl and NaOH solution was investigated. Then, the activity of heterogeneous catalyst to produced biodiesel under the variation of stirring rate, zeolite particle size, and comparison of different ion exchange catalysts were also investigated. Finally, the stability test and regeneration treatment were also investigated. The optimum operating conditions of biodiesel synthesis process is at the temperature of 60 °C for 2 h with a stirring speed of 700 rpm. Natural zeolite Bayah with 6 M of NaOH solution produced 16.19%, Amberlite gel with 6 M HCL produced 65.22% of biodiesel yield and material Lewatit macro porous with 6 M of NaOH solution produced 85.94% as the maximum result. As the best result, Material Lewatit macro porous selected as the material which was used in the variation of stirring speed, temperature, and reaction time, the concentration of base and stability test. According to the results of analysis, calculations yield methyl oleic HPLC produced by Lewatit macro porous with 6 M NaOH at 62.95%.

  19. Ion-exchange separation of radioiodine and its application to production of {sup 124}I by alpha particle induced reactions on antimony

    Energy Technology Data Exchange (ETDEWEB)

    Shuza Uddin, Md. [Forschungszentrum Juelich (Germany). Inst. fuer Neurowissenschaften und Medizin, INM-5: Nuklearchemie; Atomic Energy Research Establishment, Inst. of Nuclear Science and Technology, Dhaka (Bangladesh); Qaim, Seyed M.; Spahn, Ingo; Spellerberg, Stefan; Scholten, Bernhard; Coenen, Heinz H. [Forschungszentrum Juelich (Germany). Inst. fuer Neurowissenschaften und Medizin, INM-5: Nuklearchemie; Hermanne, Alex [Vrije Univ. Brussel (Belgium). Cyclotron Lab.; Hossain, Syed Mohammod [Atomic Energy Research Establishment, Inst. of Nuclear Science and Technology, Dhaka (Bangladesh)


    The basic parameters related to radiochemical separation of iodine from tellurium and antimony by anion-exchange chromatography using the resin Amberlyst A26 were studied. The separation yield of {sup 124}I amounted to 96% and the decontamination factor from {sup 121}Te and {sup 122}Sb was > 10{sup 4}. The method was applied to the production of {sup 124}I via the {sup 123}Sb(α, 3n) reaction. In an irradiation of 110 mg of {sup nat}Sb{sub 2}O{sub 3} (thickness ∝0.08 g/cm{sup 2}) with 38 MeV α-particles at 1.2 μA beam current for 4 h, corresponding to the beam energy range of E{sub α} = 37 → 27 MeV, the batch yield of {sup 124}I obtained was 12.42 MBq and the {sup 125}I and {sup 126}I impurities amounted to 3.8% and 0.7%, respectively. The experimental batch yield of {sup 124}I amounted to 80% of the theoretically calculated value but the level of the radionuclidic impurities were in agreement with the theoretical values. About 96% of the radioiodine was in the form of iodide and the inactive impurities (Te, Sb, Sn) were below the permissible level. Due to the relatively high level of radionuclidic impurity the {sup 124}I produced would possibly be useful only for restricted local consumption or for animal experiments.

  20. Modified ion exchange resins - synthesis and properties. Pt. 1

    Energy Technology Data Exchange (ETDEWEB)

    Doescher, F.; Klein, J.; Pohl, F.; Widdecke, H.


    Sulfomethylated resins are prepared by polymer analogous reactions, starting from macroporous poly(styrene-co-divinylbenzene) matrices. Different reaction paths are discussed and used in the synthesis. Sulfomethylation can be achieved by reaction of a chloromethylated resin with dimethyl sulfide and sodium sulfonate or alternatively by oxidation of polymer-bound thiol groups. Both methods give high conversions as shown by IR spectra and titration of the sulfonic acid groups. Poly(1-(4-hydroxysulfomethylphenyl)ethylene) (3) is obtained by reaction of poly(1-(4-hydroxyphenyl)ethylene) (2) resin with formaldehyde/sodium sulfonate. The thermal stability, catalytic activity, and ion exchange equilibria of the sulfomethylated resin are investigated.

  1. Multistep ion exchange processes of gradient refractive index rod lens. (United States)

    Lv, Hao; Liu, Aimei; Tong, Jufang; Yi, Xunong; Li, Qianguang; Wang, Xinmin; Ding, Yaoming


    A mathematical model for research on the refractive index profile (RIP) of multistep ion exchange processes (IEPs) of gradient refractive index rod lenses (GRINs) is established by the different initial condition and boundary condition, based on the Fickian diffusion equation. GRIN rod lenses have been fabricated using the three-step IEPs. Research results indicate that the experimental deviations of refractive index (DRI) are in good agreement with the theoretical data. The DRI of three-step IEPs is superior to the one- and two-step IEPs and smaller than 10(-5).

  2. Predicting Carbonate Ion Transport in Alkaline Anion Exchange Materials (United States)


    Electrochemical Society , 2013. 2. Wilson K. S. Chiu, "Part 1. Role of the 3-D Electrode Microstructure on Charge Transfer, Mass Transfer, and Electrochemical Reactions in Solid Oxide Fuel Cells; Part 2. Ion and Water Transport in Alkaline Anion Exchange Membranes," technical seminar for the Army Research Laboratory (host: Dr. Deryn Chu), Adelphi, MD, August 13, 2012. (c) Presentations Number of Presentations: 2.00 Non Peer-Reviewed Conference Proceeding publications (other than abstracts): Received Paper TOTAL: Number of Non Peer-Reviewed

  3. Complexity analysis of the glutamic acid ion-exchanged wastewater

    Institute of Scientific and Technical Information of China (English)

    林艳; 王瑞明; 徐国华; 王腾飞; 井瑞洁


    In this paper,the glutamic acid ion-exchanged wastewater has been studied.Kjeldahl determination method,Fehling reagent.muffle furnace method.and so on were used.It can be sure that the wastewater's COD is 50250 mg/L.and total solids is contains:glutamic acid 0.3%:total reducing sugar 0.414%;fat 0.4274%;ammonium sulphate 10.0758%;microbial protein 0.8045%;ash 0.27%:others 1.4683%.

  4. Separation of ammonia from wastewater using clinoptilolite as ion exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Czaran, E.; Meszaros-Kis, A.; Domokos, E.; Papp, J.


    The cation exchange properties of a Hungarian clinoptilolite rock from the Tokaj mountains have been studied. The aim of this work has been to prepare suitable cation containing forms for NH/sub 4//sup +/-removal and regeneration of the NH/sub 4//sup +/-form. The process has been followed from the start with static laboratory experiments through laboratory dynamic measurements up to pilot plant. The static CEC of the clinoptilolite containing rock proved to be 1.2 meq/q. However, under dynamic conditions this value is only 0.2 - 0.3 depending on the circumstances, thus this material is capable of the elimination of 3 - 5 mg NH/sub 3/ per g rock. The exhausted clinoptilolite can be regenerated more efficiently by potassium ions than by the usually applied sodium ions.


    Kennedy, J.


    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.

  6. Use of Novel Highly Selective Ion Exchange Media for Minimizing the Waste Arising from Different NPP and Other Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Tusa, Esko; Harjula, Risto; Lehto, Jukka


    Highly selective inorganic ion exchangers give new possibilities to implement and operate new innovative treatment systems for radioactive liquids. Because of high selectivity these ion exchangers can be used even in liquids of high salt concentrations. Only selected target nuclides will be separated and inactive salts are left in the liquid, which can be released or recategorized. Thus, it is possible to reduce the volume of radioactive waste dramatically. On the other hand, only a small volume of highly selective material is required in applications, which makes it possible to design totally new types of compact treatment systems. The major benefit of selective ion exchange media comes from the very large volume reduction of radioactive waste in final disposal. It is also possible to save in investment costs, because small ion exchanger volumes can be used and handled in a very small facility. This paper describes different applications of these highly selective ion exchangers, both commercial fullscale applications and laboratory tests, to give the idea of their efficiency for different liquids.

  7. Application of ion exchange and extraction chromatography to the separation of actinium from proton-irradiated thorium metal for analytical purposes. (United States)

    Radchenko, V; Engle, J W; Wilson, J J; Maassen, J R; Nortier, F M; Taylor, W A; Birnbaum, E R; Hudston, L A; John, K D; Fassbender, M E


    Actinium-225 (t1/2=9.92d) is an α-emitting radionuclide with nuclear properties well-suited for use in targeted alpha therapy (TAT), a powerful treatment method for malignant tumors. Actinium-225 can also be utilized as a generator for (213)Bi (t1/2 45.6 min), which is another valuable candidate for TAT. Actinium-225 can be produced via proton irradiation of thorium metal; however, long-lived (227)Ac (t1/2=21.8a, 99% β(-), 1% α) is co-produced during this process and will impact the quality of the final product. Thus, accurate assays are needed to determine the (225)Ac/(227)Ac ratio, which is dependent on beam energy, irradiation time and target design. Accurate actinium assays, in turn, require efficient separation of actinium isotopes from both the Th matrix and highly radioactive activation by-products, especially radiolanthanides formed from proton-induced fission. In this study, we introduce a novel, selective chromatographic technique for the recovery and purification of actinium isotopes from irradiated Th matrices. A two-step sequence of cation exchange and extraction chromatography was implemented. Radiolanthanides were quantitatively removed from Ac, and no non-Ac radionuclidic impurities were detected in the final Ac fraction. An (225)Ac spike added prior to separation was recovered at ≥ 98%, and Ac decontamination from Th was found to be ≥ 10(6). The purified actinium fraction allowed for highly accurate (227)Ac determination at analytical scales, i.e., at (227)Ac activities of 1-100 kBq (27 nCi to 2.7 μCi). Copyright © 2014 Elsevier B.V. All rights reserved.

  8. An orientation sensitive approach in biomolecule interaction quantitative structure-activity relationship modeling and its application in ion-exchange chromatography. (United States)

    Kittelmann, Jörg; Lang, Katharina M H; Ottens, Marcel; Hubbuch, Jürgen


    Quantitative structure-activity relationship (QSAR) modeling for prediction of biomolecule parameters has become an established technique in chromatographic purification process design. Unfortunately available descriptor sets fail to describe the orientation of biomolecules and the effects of ionic strength in the mobile phase on the interaction with the stationary phase. The literature describes several special descriptors used for chromatographic retention modeling, all of these do not describe the screening of electrostatic potential by the mobile phase in use. In this work we introduce two new approaches of descriptor calculations, namely surface patches and plane projection, which capture an oriented binding to charged surfaces and steric hindrance of the interaction with chromatographic ligands with regard to electrostatic potential screening by mobile phase ions. We present the use of the developed descriptor sets for predictive modeling of Langmuir isotherms for proteins at different pH values between pH 5 and 10 and varying ionic strength in the range of 10-100mM. The resulting model has a high correlation of calculated descriptors and experimental results, with a coefficient of determination of 0.82 and a predictive coefficient of determination of 0.92 for unknown molecular structures and conditions. The agreement of calculated molecular interaction orientations with both, experimental results as well as molecular dynamic simulations from literature is shown. The developed descriptors provide the means for improved QSAR models of chromatographic processes, as they reflect the complex interactions of biomolecules with chromatographic phases.

  9. Ion-Isotopic Exchange Reaction Kinetics using Anion Exchange Resins Dowex 550A LC and Indion-930A

    Directory of Open Access Journals (Sweden)

    P.U. Singare


    Full Text Available The present paper deals with the characterization of ion exchange resins Dowex 550A LC and Indion-930A based on kinetics of ion-isotopic exchange reactions for which the short lived radioactive isotopes 131I and 82Br were used as a tracers. The study was performed for different concentration of ionic solution varying from 0.001 mol/L to 0.004 mol/L and temperature in the range of 30.0 °C to 45.0 °C. The results indicate that as compared to bromide ion-isotopic exchange reaction, iodide exchange reaction take place at the faster rate. For both the ion-isotopic exchange reactions, under identical experimental conditions, the values of specific reaction rate increases with increase in the ionic concentration and decreases with rise in temperature. It was observed that at 35.00C, 1.000 g of ion exchange resins and 0.002 mol/L labeled iodide ion solution for iodide ion-isotopic exchange reaction, the values of specific reaction rate (min-1, amount of ion exchanged (mmol, initial rate of ion exchange (mmol/min and log Kd were 0.270, 0.342, 0.092 and 11.8 respectively for Dowex 550A LC resin, which was higher than the respective values of 0.156, 0.241, 0.038 and 7.4 as that obtained for Indion-930A resins. From the results, it appears that Dowex 550A LC resins show superior performance over Indion-930A resins under identical experimental conditions.

  10. Anion selective membrane. [ion exchange resins and ion exchange membrane electrolytes for electrolytic cells (United States)

    Alexander, S. S.; Geoffroy, R. R.; Hodgdon, R. B.


    Experimental anion permselective membranes were prepared and tested for their suitability as cell separators in a chemical redox power storage system being developed at NASA-Lewis Research Center. The goals of long-term (1000 hr) oxidative and thermal stability at 80 C in FeCl3 and CrCl3 electrolytes were met by most of the weak base and strong base amino exchange groups considered in the program. Good stability is exhibited by several of the membrane substrate resins. These are 'styrene' divinylbenzene copolymer and PVC film. At least four membrane systems produce strong flexible films with electrochemical properties (resistivity, cation transfer) superior to those of the 103QZL, the most promising commercial membrane. The physical and chemical properties of the resins are listed.

  11. Impact of natural organic matter properties on the kinetics of suspended ion exchange process. (United States)

    Bazri, Mohammad Mahdi; Mohseni, Madjid


    Removal kinetics of four standard organic matter isolates under the application of strongly basic ion exchange resins (IEX) in suspended mode was studied under commercial application conditions. Suwannee River natural organic matter (SRNOM), SR fulvic acid (SRFA), and Pony Lake fulvic acid (PLFA) were greatly removed (>90%) and highly preferred by IEX resins (α > 5, over Cl(-), and HCO3(-)) while SR humic acid (SRHA) was the least preferred organic structure among the four isolates studied (α ≈ 1). Moreover, the efficacy of removal for fulvic acids (i.e., SRFA, PLFA) was consistent over consecutive reuse of IEX resins (i.e., loading cycles) whereas it decreased for SRNOM and SRHA over the course of operation. The stoichiometric correlation between the chloride released from the resins as a result of organic molecules uptake indicated that ion exchange was the dominant mechanism. Results obtained indicated that molecular weight and charge density of isolates played a major role in the performance of ion exchange process for organic matter removal. Furthermore, various empirical and physical models were evaluated using the experimental data and pore diffusion was found to be the rate-liming step during the uptake of organic matters; hence, it was used as the appropriate model to predict the kinetics of removal. Consequently, free liquid diffusivities and effective pore diffusion coefficients of organic molecules were estimated and findings were in agreement with the literature data that were obtained from spectrophotometric methods.

  12. Capillary ion-exchange chromatography with nanogram sensitivity for the analysis of monoclonal antibodies. (United States)

    Rea, Jennifer C; Freistadt, Benny S; McDonald, Daniel; Farnan, Dell; Wang, Yajun Jennifer


    Ion-exchange chromatography (IEC) is widely used for profiling the charge heterogeneity of proteins, including monoclonal antibodies (mAbs). Despite good resolving power and robustness, ionic strength-based ion-exchange separations are generally product specific and can be time consuming to develop. In addition, conventional analytical scale ion-exchange separations require tens of micrograms of mAbs for each injection, amounts that are often unavailable in sample-limited applications. We report the development of a capillary IEC (c-IEC) methodology for the analysis of nanogram amounts of mAb charge variants. Several key modifications were made to a commercially available liquid chromatography system to perform c-IEC for charge variant analysis of mAbs with nanogram sensitivity. We demonstrate the method for multiple monoclonal antibodies, including antibody fragments, on different columns from different manufacturers. Relative standard deviations of <10% were achieved for relative peak areas of main peak, acidic and basic regions, which are common regions of interest for quantifying monoclonal antibody charge variants using IEC. The results herein demonstrate the excellent sensitivity of this c-IEC characterization method, which can be used for analyzing charge variants in sample-limited applications, such as early-stage candidate screening and in vivo studies.

  13. High performance disulfonated poly(arylene sulfone) co- and terpolymers for proton exchange membranes for fuel cell and transducer applications: Synthesis, characterization and fabrication of ion conducting membranes (United States)

    Wiles, Kenton Broyhill


    The results described in this dissertation have demonstrated several alternative proton exchange membranes (PEM) for hydrogen-air and direct methanol fuel cells (DMFC) that perform as well or better than the state of the art Nafion perfluorosulfonic acid membrane. Direct aromatic nucleophilic substitution polycondensations of disodium 3,3'-disulfonate-4,4 '-difluorodiphenylsulfone (SDFDPS), 4,4'-difluorodiphenylsulfone (DFDPS) (or their chlorinated analogs, SDCDPS, DCDPS) and 4,4' -thiobisbenzenethiol (TBBT) in the presence of potassium carbonate were investigated. Electrophilic aromatic substitution was employed to synthesize the SDFDPS or SDCDPS comonomers in high yields and purity. High molecular weight disulfonated poly(arylene thioether sulfone) (PATS) copolymers were easily obtained using the SDFDPS monomers, but in general, slower rates and a lower molecular weight copolymer was obtained using the analogous chlorinated monomers. Tough and ductile membranes were solution cast from N,N-dimethylacetamide for both series of copolymers. The degrees of disulfonation (20--50%, PATS 20--50) were controlled by varying the ratio of disulfonated to unsulfonated comonomers. Composite membranes were prepared by homogeneous solution blending the copolymers with phosphotungstic acid (PTA) in dimethylacetamide (DMAc). The composite PATS membranes exhibited moderate PTA molecule water extraction after acidification treatments performed at either room or boiling temperatures. The membranes containing HPA showed improved conductivity at high temperatures (120°C) and low relative humidities when compared to the pure copolymers. Molecular weight of the copolymers plays a critical role in the overall copolymer physical behavior. It is well known that molecular weight has an enormous impact on practically all of the physical properties of polymeric systems. This dissertation discusses the influence of molecular weight on the characteristics of a specific family of PEM PATS

  14. Ag clustering investigation in laser irradiated ion-exchanged glasses by optical and vibrational spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Trave, E., E-mail: [Department of Molecular Sciences and Nanosystems, Ca' Foscari University of Venezia, Dorsoduro 2137, I-30123 Venezia (Italy); Cattaruzza, E.; Gonella, F.; Calvelli, P. [Department of Molecular Sciences and Nanosystems, Ca' Foscari University of Venezia, Dorsoduro 2137, I-30123 Venezia (Italy); Quaranta, A. [Department of Materials Engineering and Industrial Technologies, University of Trento, via Mesiano 77, I-38050 Povo (Italy); Rahman, A.; Mariotto, G. [Department of Computer Science, University of Verona, Strada le Grazie 15, 37134 Verona (Italy)


    Highlights: Black-Right-Pointing-Pointer We modify the properties of Ag{sup +} exchanged glasses by thermal and laser treatment. Black-Right-Pointing-Pointer The induced microstructural changes are analyzed by optical and Raman spectroscopy. Black-Right-Pointing-Pointer Ag-based species in the glass show a peculiar PL activity in the UV-Vis range. Black-Right-Pointing-Pointer Raman and OA analysis allow for determining the Ag cluster size evolution. Black-Right-Pointing-Pointer Laser processing leads to different cluster formation and fragmentation mechanisms. - Abstract: Ion exchange process is widely used to dope silicate glass layers with silver for several applications, ranging from light waveguide to nanostructured composite glass fabrication. The silver-doped structure and its physical properties depend on the preparation parameters as well as on subsequent treatments. In particular, laser irradiation of the ion exchanged glasses has been demonstrated to be an effective tool to control cluster size and size distribution. Nevertheless, a complete comprehension of the basic phenomena and a systematic characterization of these systems are still lacking. In this paper, an extended optical characterization is presented for soda-lime glass slides, doped with silver by Ag{sup +}-Na{sup +} ion exchange, thermally treated and irradiated with a Nd:YAG laser beam at different wavelengths, and for different energy density. The samples were characterized by various spectroscopic techniques, namely, optical absorption, photoluminescence and micro-Raman analysis. The availability of all these characterization techniques allowed pointing out a suitable scenario for the Ag clustering evolution as a function of the ion exchange, annealing and laser irradiation parameters.

  15. Expanded-bed adsorption utilizing ion-exchange resin to purify extracellular beta-galactosidase. (United States)

    Pereira, J A; Vieira E Rosa, P De T; Pastore, G M; Santana, C C


    The application of expanded-bed ion-exchange resins allows the elimination of intermediary particulate separation steps like filtration or centrifugation prior to adsorption steps in enzyme-purification processes from crude fermentation broths. This work is concerned with the experimental evaluation data of a process related to the adsorption of an extracellular p-galactosidase from the fungi Scopulariopsis. The protein recovery in the ion-exchange resin Accell Plus QMA was accomplished using a continuous-monitoring method. The direct adsorption step was followed by a elution step with concentrated NaCl solutions aiming to improve the enzyme-specific activity. Experimental data for fixed and expanded bed were compared.

  16. A Simple and Efficient Method for Purification of Egg White Major Proteins Using Ion Exchange Chromatography

    Directory of Open Access Journals (Sweden)

    Sh. Veisi


    Full Text Available Introduction & Objective: Egg white contains four high-quantity proteins which have numerous applications. In this research, a simple and efficient method for the purification of those proteins was designed and performed based on ion exchange chromatography.Materials & Methods: In this experimental study egg white was initially separated from insoluble substances by acidic pH. The resulting extract was isolated after two steps of ion exchange chromatography using CM-Sepharose and DEAE-Sepharose columns, respectively. Purification degree and yield of each fraction were analyzed by electrophoresis densitometry.Results: The results showed that purification degrees of ovalbumin, ovotransferrin, ovomucoid and lysozyme were 97, 98, 85 and 99 percent and their yields were 98, 98 95 and 99 percent, respectively.Conclusion: High yields, reproducibility and feasibility on low or high scales are considered as the strengths of this method.

  17. Controlled oxidative protein refolding using an ion-exchange column. (United States)

    Langenhof, Marc; Leong, Susanna S J; Pattenden, Leonard K; Middelberg, Anton P J


    Column-based refolding of complex and highly disulfide-bonded proteins simplifies protein renaturation at both preparative and process scale by integrating and automating a number of operations commonly used in dilution refolding. Bovine serum albumin (BSA) was used as a model protein for refolding and oxido-shuffling on an ion-exchange column to give a refolding yield of 55% after 40 h incubation. Successful on-column refolding was conducted at protein concentrations of up to 10 mg/ml and refolded protein, purified from misfolded forms, was eluted directly from the column at a concentration of 3 mg/ml. This technique integrates the dithiothreitol removal, refolding, concentration and purification steps, achieving a high level of process simplification and automation, and a significant saving in reagent costs when scaled. Importantly, the current result suggests that it is possible to controllably refold disulfide-bonded proteins using common and inexpensive matrices, and that it is not always necessary to control protein-surface interactions using affinity tags and expensive chromatographic matrices. Moreover, it is possible to strictly control the oxidative refolding environment once denatured protein is bound to the ion-exchange column, thus allowing precisely controlled oxido-shuffling.

  18. UREA/ammonium ion removal system for the orbiting frog otolith experiment. [ion exchange resins for water treatment during space missions (United States)

    Schulz, J. R.; Anselmi, R. T.


    The feasibility of using free urease enzyme and ANGC-101 ion exchange resin to remove urea and ammonium ion for space system waste water applications was studied. Specifically examined is the prevention of urea and ammonia toxicity in a 30-day Orbiting Frog Otolith (OFO) flight experiment. It is shown that free urease enzyme used in conjunction with ANGC-101 ion-exchange resin and pH control can control urea and amonium ion concentration in unbuffered recirculating water. In addition, the resin does not adversely effect the bullfrogs by lowering the concentration of cations below critical minimum levels. Further investigations on bioburden control, frog waste excretion on an OFO diet, a trade-off analysis of methods of automating the urea/ammonium ion removal system and fabrication and test of a semiautomated breadboard were recommended as continuing efforts. Photographs of test equipment and test animals are shown.

  19. Isotope exchange by Ion Cyclotron Wall Conditioning on JET

    Energy Technology Data Exchange (ETDEWEB)

    Wauters, T., E-mail: [Laboratory for Plasma Physics, ERM/KMS, TEC Partner, 1000 Brussels (Belgium); Douai, D.; Kogut, D. [CEA, IRFM, F-13108 St-Paul-Lez-Durance (France); Lyssoivan, A. [Laboratory for Plasma Physics, ERM/KMS, TEC Partner, 1000 Brussels (Belgium); Brezinsek, S. [Forschungszentrum Jülich, Institut für Energie- und Klimaforschung Plasmaphysik, 52425 Jülich (Germany); Belonohy, E. [Max-Planck Institut für Plasmaphysik, 85748 Garching (Germany); Blackman, T. [JET-EFDA, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Bobkov, V. [Max-Planck Institut für Plasmaphysik, 85748 Garching (Germany); Crombé, K. [Laboratory for Plasma Physics, ERM/KMS, TEC Partner, 1000 Brussels (Belgium); Drenik, A. [Jožef Stefan Institute, 1000 Ljubljana (Slovenia); Graham, M. [JET-EFDA, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Joffrin, E. [CEA, IRFM, F-13108 St-Paul-Lez-Durance (France); Lerche, E. [Laboratory for Plasma Physics, ERM/KMS, TEC Partner, 1000 Brussels (Belgium); Loarer, T. [CEA, IRFM, F-13108 St-Paul-Lez-Durance (France); Lomas, P.L.; Mayoral, M.-L.; Monakhov, I. [JET-EFDA, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Oberkofler, M. [Max-Planck Institut für Plasmaphysik, 85748 Garching (Germany); Philipps, V. [Forschungszentrum Jülich, Institut für Energie- und Klimaforschung Plasmaphysik, 52425 Jülich (Germany); Plyusnin, V. [IST, Instituto de Plasmas e Fusão Nuclear, 1049-001 Lisboa (Portugal); and others


    The isotopic exchange efficiencies of JET Ion Cyclotron Wall Conditioning (ICWC) discharges produced at ITER half and full field conditions are compared for JET carbon (C) and ITER like wall (ILW). Besides an improved isotope exchange rate on the ILW providing cleaner plasma faster, the main advantage compared to C-wall is a reduction of the ratio of retained discharge gas to removed fuel. Complementing experimental data with discharge modeling shows that long pulses with high (∼240 kW coupled) ICRF power maximizes the wall isotope removal per ICWC pulse. In the pressure range 1–7.5 × 10{sup −3} Pa, this removal reduces with increasing discharge pressure. As most of the wall-released isotopes are evacuated by vacuum pumps in the post discharge phase, duty cycle optimization studies for ICWC on JET-ILW need further consideration. The accessible reservoir by H{sub 2}-ICWC at ITER half field conditions on the JET-ILW preloaded by D{sub 2} tokamak operation is estimated to be 7.3 × 10{sup 22} hydrogenic atoms, and may be exchanged within 400 s of cumulated ICWC discharge time.

  20. A comparative study of chelating and cationic ion exchange resins for the removal of palladium(II) complexes from acidic chloride media. (United States)

    Hubicki, Zbigniew; Wołowicz, Anna


    The increasing demand for palladium for technological application requires the development of ion exchange chromatography. Recently ion exchange chromatography has developed largely as a result of new types of ion exchangers available on the market of which two types are widely applied. One of them are selective (chelating) and modified ion exchangers and the other one are liquid exchangers. Two types of ion exchange resins such as chelating (Lewatit TP 214, Purolite S 920) and cationic (Chelite S, Duolite GT 73) ion exchangers are used for the recovery of palladium(II) complexes from chloride media (0.1-2.0M HCl-1.0M NaCl-0.0011 M Pd(II); 0.1-2.0M HCl-2.0M NaCl-0.0011M Pd(II)). The influence of concentration of hydrochloric acid, sodium chloride as well as the phase contact time on the degree of recovery of palladium(II) complexes was studied. Moreover, the amount of palladium(II) chlorocomplexes sorbed onto ion exchangers, the working ion exchange capacities and the weight and bed distribution coefficients were calculated in order to judge which of two types of resins possesses the best performance towards palladium(II) complexes.

  1. Ammonia removal from wastewater by ion exchange in the presence of organic contaminants. (United States)

    Jorgensen, T C; Weatherley, L R


    The scope of this study was the removal of ammonium by ion exchange from simulated wastewater. The study looks at the effect of organics upon ammonium ion exchange equilibrium uptake. The ion exchangers included a natural zeolite clinoptilolite, and two polymeric exchangers, Dowex 50w-x8, and Purolite MN500. The organic compounds studied included citric acid and a number of proteins. The traditional method for removal of ammonium and organic pollutants from wastewater is biological treatment, but ion exchange offers a number of advantages including the ability to handle shock loadings and the ability to operate over a wider range of temperatures. The results show that in most of the cases studied, the presence of organic compounds enhances the uptake of ammonium ion onto the ion exchangers.


    Institute of Scientific and Technical Information of China (English)

    ZHANGHui; SHAOTong; 等


    The adsorption isotherms of glycine,alanine and oxidized glutathion on strong acid cation and strong base anion exchange resins from aqueous solutions were measured and the superequivalent adsorptions of glycine and alanine observed.The infrared spectra of glycine adsorbed on the cation and the anion exchange resins,001×7 and 201×7,were measured.From these results,it is concluded that the amino acid adsorption on the ion exchange resin proceeds not only through ion exchange and proton transfer mechanisms,but also through aminecarboxylate interaction between the adsorbed amino acid molecules,and the formation of second layer of amino acid molecules is the mechanism of superequivalent adsorption of amino acid,the carboxylate or amine groups of the first layer of amino acid molecules on the ion exchange resin act as the exchange sites for the second layer of amino acid molecules.


    Institute of Scientific and Technical Information of China (English)

    YangGengliang; ZhangXiaomin; 等


    In this paper,the kinetic moment expressions and rate laws are derived for pellicular ion exchange materials with various geometrical forms under the conditions that ion exchange rate is controlled by both the partical diffusion and the film diffusion in finite solution volume.In addition,for strong acidic cation ion exchange fibre,by using the equations obtained we calculated the partical diffusion coefficients and the transfer coefficients in the film under different experimental conditions.

  4. Programmatic Re-Evaluation of Ion Exchange as a 1st Generation ITP Replacement

    Energy Technology Data Exchange (ETDEWEB)

    Scott, A.B. [Westinghouse Savannah River Company, AIKEN, SC (United States)


    This re-evaluation differs from previous work in that (1) the Ion Exchange option was evaluated from a standpoint assuming that ITP would never start up, thus Ion Exchange was the only viable option, (2) the DOE prescribed balanced assumptions were quite different than the WSRC Assumptions used previously, and (3) other Site events and changes within HLWM have tended to reduce the disadvantages of Ion Exchange relative to ITP as the first generation salt decontamination process.

  5. Potassium-and silver-double-ion-exchanged slab glass waveguides: characterization and modeling. (United States)

    Auger, P L; Najafi, S I


    Double-ion-exchanged glass waveguides are made first by a potassium-ion exchange followed by a silver-ion exchange. The inverse WKB method is used to determine the index profile. It is shown that a combination of a truncated quadratic function and a complementary error function represents the refractive index best. A direct WKB method is employed to find the maximum index change and the diffusion coefficient of the second exchange process. The concentration of silver, potassium, and sodium ions are measured by an x-ray photoelectron spectroscopy technique. The results agree well with the index profile when a quadratic function is used.

  6. Reactive ion exchange synthesis of high pure nano-CeO2

    Institute of Scientific and Technical Information of China (English)

    ZHU Shao-min; FENG Ying-chun; WEN Yang; JIANG Yu-ling


    This paper presents a reactive ion exchange synthesis method of nano-CeO2 with positive cerium preexchanged ion exchange resin as precursor and (NH4)2CO3 as precipitant.The resultant precipitate was dried at 100 ℃ for 12 h and then was calcined at 500 K in air.The effects of ion exchange temperature and reaction time on the diameter of CeO2 particle were discussed.The TEM images show that the samples prepared with one step reactive ion exchange method are composed of nano-club with the length about 300 nm.

  7. The use of fuel cell ion exchange membranes in electrolytic cells les membranes echangeuses d'ions des piles a combustibles

    Energy Technology Data Exchange (ETDEWEB)

    Damien, A.; Sohm, J.C.


    Ion exchange membranes, previously used in fuel cells, were studied in order to examine their application to water electrolysis. State-of-the-art is reviewed from the bibliography, comparing this process with a classic one. Results show that only the cationic membranes are adequate for electrolytic cell use, being sufficiently resistant to heat and oxidation.

  8. Assessment of potential toxicity and aquatic community impacts associated with membrane and ion exchange water treatment facility effluents in coastal North Carolina (United States)

    US Fish and Wildlife Service, Department of the Interior — The application of reverse osmosis and ion exchange water treatment of groundwater to meet the growing potable water demand in eastern North Carolina has prompted...

  9. Ion Exchange Column Tests Supporting Technetium Removal Resin Maturation

    Energy Technology Data Exchange (ETDEWEB)

    Nash, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); McCabe, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hamm, L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Smith, F. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Morse, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)


    The primary treatment of the tank waste at the DOE Hanford site will be done in the Waste Treatment and Immobilization Plant, currently under construction. The baseline plan for this facility is to treat the waste, splitting it into High Level Waste (HLW) and Low Activity Waste (LAW). Both waste streams are then separately vitrified as glass and sealed in canisters. The LAW glass will be disposed on site. There are currently no plans to treat the waste to remove technetium, so its disposition path is the LAW glass. Due to the soluble properties of pertechnetate and long half-life of 99Tc, effective management of 99Tc is important. Options are being explored to immobilize the supplemental LAW portion of the tank waste, as well as to examine the volatility of 99Tc during the vitrification process. Removal of 99Tc, followed by off-site disposal has potential to reduce treatment and disposal costs. A conceptual flow sheets for supplemental LAW treatment and disposal that could benefit from technetium removal will specifically examine removing 99Tc from the LAW feed stream to supplemental immobilization. SuperLig® 639 is an elutable ion exchange resin. In the tank waste, 99Tc is predominantly found in the tank supernate as pertechnetate (TcO4-). Perrhenate (ReO4-) has been shown to be a good non-radioactive surrogate for pertechnetate in laboratory testing for this ion exchange resin. This report contains results of experimental ion exchange distribution coefficient and column resin maturation kinetics testing using the resin SuperLig® 639a to selectively remove perrhenate from simulated LAW. This revision includes results from testing to determine effective resin operating temperature range. Loading tests were performed at 45°C, and the computer modeling was updated to include the temperature effects. Equilibrium contact testing indicated that this batch of

  10. Studies of removal of palladium(II) ions from chloride solutions on weakly and strongly basic anion exchangers. (United States)

    Hubicki, Z; Wołowicz, A; Leszczyńska, M


    Palladium and its compounds find wide application in industry as a catalytic agent in different manufacture processes. Recovery of precious metals from industrial wastes is difficult and time consuming but in spite of these disadvantages it becomes profitable. Palladium(II) ions sorption from various chloride solutions of the composition: 0.1-6.0M HCl-0.00056 M Pd(II), 1.0M ZnCl(2)-0.1M HCl-0.00056 M Pd(II), 1.0M AlCl(3)-0.1M HCl-0.00056 M Pd(II) on the weakly and strongly basic anion exchangers (Varion ATM, Varion ADM and Varion ADAM) was discussed. The sorption research of Pd(II) ions on these resins was carried out by means of static and dynamic methods. The dynamic processes were applied in order to determine the breakthrough curves of Pd(II) ions. Moreover, the working ion-exchange capacities as well as the weight and bed distribution coefficients were determined from the Pd(II) breakthrough curves. The recovery factors of Pd(II) ions (% R) depending on the phase contact time were obtained by means of static methods. The highest ion-exchange capacities for the 0.1-6.0M HCl-0.00056 M Pd(II) systems were obtained for the weakly basic ion-exchange resin Varion ADAM.

  11. Ultra-low vanadium ion diffusion amphoteric ion-exchange membranes for all-vanadium redox flow batteries (United States)

    Liao, J. B.; Lu, M. Z.; Chu, Y. Q.; Wang, J. L.


    An amphoteric ion-exchange membrane (AIEM) from fluoro-methyl sulfonated poly(arylene ether ketone) bearing content-controlled benzimidazole moiety, was firstly fabricated for vanadium redox flow battery (VRB). The AIEM and its covalently cross-linked membrane (AIEM-c) behave the highly suppressed vanadium-ion crossover and their tested VO2+ permeability are about 638 and 1117 times lower than that of Nafion117, respectively. This is further typically verified by the lower VO2+ concentration inside AIEM that is less than half of that inside Nafion117 detected by energy dispersive X-ray spectrometry, in addition of the nearly 3 times longer battery self-discharge time. The ultra-low vanadium ion diffusion could be ascribed to the narrower ion transporting channel originated from the acid-base interactions and the rebelling effect between the positively-charged benzimidazole structure and VO2+ ions. It is found that, VRB assembled with AIEM exhibits the equal or higher Coulombic efficiency (99.0% vs. 96.4%), voltage efficiency (90.7% vs. 90.7%) and energy efficiency (89.8% vs. 87.4%) than that with Nafion117 and keeps continuous 220 charge-discharge cycles for over 25 days, confirming that the AIEM of this type is a potentially suitable separator for VRB application.

  12. Increasing parvovirus filter throughput of monoclonal antibodies using ion exchange membrane adsorptive pre-filtration. (United States)

    Brown, Arick; Bechtel, Charity; Bill, Jerome; Liu, Hui; Liu, Jun; McDonald, Dan; Pai, Satyan; Radhamohan, Asha; Renslow, Ryan; Thayer, Brooke; Yohe, Stefan; Dowd, Chris


    Pre-filtration using ion exchange membrane adsorbers can improve parvovirus filter throughput of monoclonal antibodies (mAbs). The membranes work by binding trace foulants, and although some antibody product also binds, yields > or =99% are easily achieved by overloading. Results show that foulant adsorption is dependent on pH and conductivity, but independent of scale and adsorber brand. The ability to use ion exchange membranes as pre-filters is significant because it provides a clean, well defined, chemically stable option for enhancing throughput. Additionally, ion exchange membranes facilitate characterization of parvovirus filter foulants. Examination of adsorber elution samples using sedimentation velocity analysis and SEC-MALS/QELS revealed the presence of high molecular weight species ranging from 8 to 13 nm in hydrodynamic radius, which are similar in size to parvoviruses and thus would be expected to plug the pores of a parvovirus filter. A study of two identical membranes in-series supports the hypothesis that the foulants are soluble, trace level aggregates in the feed. This study's significance lies in a previously undiscovered application of membrane chromatography, leading to a more cost effective and robust approach to parvovirus filtration for the production of monoclonal antibodies.

  13. Tailoring orthogonal proteomic routines to understand protein separation during ion exchange chromatography. (United States)

    Cabrera, Rosa; Zhelyazkova, Petya; Galvis, Leonardo; Fernandez-Lahore, Marcelo


    Surface charge, molecular weight, and folding state are known to influence protein chromatographic behaviour onto ion exchangers. Experimentally, information related to such factors can be gathered via 2-DE methods. The application of 2-D PAGE under denaturing/reducing conditions was already shown to reveal separation trends within a large protein population from cell extracts. However, ion-exchange chromatography normally runs under native conditions. A tailored protocol consisting in a first separation based on IEF on Immobiline strips under native conditions followed by a second dimension SDS-PAGE run was adopted. The chromatographic versus electrophoretic separation behaviours of two model proteins, thaumatin (TAU) and BSA, were compared to better understand which proteomic routine would be better suited to anticipate IEX chromatographic separations. It was observed that the information contained in the pI value obtained with the adapted 2-DE protocol showed better correlation with the IEX chromatographic behaviour. On the other hand, chromatographic separations performed in the presence of urea as a denaturant have demonstrated the potential influence of hydrodynamic radius/conformation on protein separation. Moreover, the information provided by such 2-D system correlated well with the chromatographic behaviour of an additional set of pure proteins. An initial prediction of protein ion-exchange chromatographic behaviour could be possible utilizing an experimental approach based on 2-DE running under milder chemical conditions. This technique provides information that more closely resembles the separation behaviour observed with a complex biotechnological feedstock.

  14. Physico-chemical study of the thermal degradation of ions exchange resins of nuclear origin: research of conditions to limit the pollution transfer, application to electric cables; Etude physico-chimique de la degradation thermique des resines echangeuses d'ions d'origine nucleaire: recherche des conditions limitant le transfert de pollution, application aux cables electriques

    Energy Technology Data Exchange (ETDEWEB)

    Antonetti, P


    The ions exchange resins are one solid form of radioactive wastes. They are found mainly during the demineralization operations of the water from reactors cooling systems. This study aims to determine the conditions of a thermal processing leading to the production of a smaller residue, containing the whole activity. A protocol is proposed and validated on resins allowing a decrease of the volume of 63% for 99,93% of the activity. (A.L.B.)


    Directory of Open Access Journals (Sweden)

    I. A. Dyomichev


    Full Text Available We present spectra of the alkali-silicate glasses with copper ions in near-surface area, introduced by ion exchange of different temperature and duration. It is shown that the reduction of Cu2+ in the near-surface area causes existence of Cu+ and neutral atoms in glass after the ion-exchange in divalent salt. The ion-exchange itself involves only Cu+ and Na+ ions. The formation of subnanometer clusters Cun is due to neutral copper atoms staying in near-surface zone. We have shown that the waveguide layer in near-surface area, made by ion-exchange, has а visible luminescence with the excitation by UVradiation. At the same time, the contribution to luminescence is made by Cu+ ions, molecular clusters Cun and by dimers Cu+ - Cu+ . During the high-temperature ion-exchange at 600 °С the formation and destruction equilibrium shift of molecular clusters Cun can be seen. An hour ion-exchange leads to molecular clusters Cun destruction, while at time periods less than 30 min and around 18 hours it leads to the formation of Cun. The sample turns green after 18,5 hours ion-exchange showing formation of a considerable amount of divalent copper ions Cu2+ therein.

  16. Solvent and irradiation doses effects on the ion exchange capacity of sulfonated styrene grafted PVDF

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Henrique P.; Parra, Duclerc F.; Lugao, Ademar B. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)


    Polymers exhibiting ion exchange capacity are studied for many years due to their application in several fields, such as membranes for proton exchange fuel cells, filtration membranes, heavy ions recovery and artificial muscles and sensors. Radiation induced grafting followed by sulfonation is a well-known way to obtain ion exchange polymers. Fluorinated polymers are frequently used as polymeric matrix for grafting due to their excellent physicochemical properties. Radiation induced grafting of styrene into poly (vinylidene fluoride) (PVDF) by simultaneous method in 1:1 styrene/toluene or styrene/N,N-dimethylformamide solutions was studied. Irradiations were performed under nitrogen atmosphere, room temperature and at doses of 5, 10 and 20 kGy with dose rate of 5 kGy.h{sup -1} from a {sup 60}Co gamma source. After washing, grafted materials were sulfonated in 10% chlorosulfonic acid/1,2-dichloroethane solutions for 4 h at room temperature. Characterization shows that increasing irradiation dose corresponds to increases in the grafting yield (GY %) gravimetrically calculated and these different solvents shows different grafting behaviors. Toluene allows no more than 3 % of grafting while DMF allows up to 55 % of grafting in the same condition. Grafting in toluene solution occurs on the surface and in DMF solution it occurs in the bulk, as confirmed by SEM. Both irradiation doses and solvent used have direct effects in the ion exchange capacities (calculated after titrations). FT-IR spectra exhibit new peaks after grafting and after sulfonation, attributed to grafted monomer and sulfonic groups attached to the styrene. DSC shows differences in thermal behavior of the polymer before and after each step. (author)

  17. Charge Exchange Collisions between Ultracold Fermionic Lithium Atoms and Calcium Ions

    CERN Document Server

    Haze, Shinsuke; Saito, Ryoichi; Mukaiyama, Takashi


    An observation of charge exchange collisions between ultracold fermionic 6Li atoms and 40Ca+ ions is reported. The reaction product of the charge exchange collision is dentified via mass spectrometry where the motion of the ions is excited parametrically. We measure the cross section of the charge exchange collisions between the 6Li atoms in the ground state and the 40Ca+ ions in the ground and metastable excited states. Investigation of the inelastic collision characteristics in the atom-ion mixture is an important step toward ultracold chemistry based on ultracold atoms and ions.

  18. Determination of effective capacities of ion-exchangeable materials by measuring the equilibrium conductivity. (United States)

    Okabe, Toshiaki; Yokoyama, Yukio


    The effective ion-exchange capacities of ion-exchange materials were determined by measuring the change in the equilibrium conductivity of a column packed with analyte. The developed instrumental method can provide effective ion-exchange capacities for both cation and anion exchangers with simple operations. The cation-exchange capacity of a weak-acid cation-exchange resin (TSKgel SuperIC-Cation column) depended on the conditioning pH and the molar concentration of the conditioning agent. Plots of effective cation-exchange capacities over the conditioning pH exhibited three inflection points, suggesting the presence of two carboxy groups and one phenolic OH group in the resin, probably due to the inherent base polymer. This method was applied to several commercial analytical columns for ion chromatography, and could provide scientifically useful results for characterizing the resin properties.

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

    Energy Technology Data Exchange (ETDEWEB)

    Baroch, C.J. [Wastren, Inc., Westminster, CO (United States); Grant, P.J. [Wastren, Inc., Hummelstown, PA (United States)


    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.

  20. Advanced integrated solvent extraction and ion exchange systems

    Energy Technology Data Exchange (ETDEWEB)

    Horwitz, P. [Argonne National Lab., IL (United States)


    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.

  1. Copper ion-exchanged channel waveguides optimization for optical trapping. (United States)

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


    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.

  2. Solidification of Spent Ion Exchange Resin Using ASC Cement

    Institute of Scientific and Technical Information of China (English)

    周耀中; 云桂春; 叶裕才


    Ion exchange resins (IERs) have been widely used in nuclear facilities. However, the spent radioactive IERs result in major quantities of low and intermediate level radioactive wastes. This article describes a laboratory experimental study on solidification processing of IERs using a new type of cement named ASC cement. The strength of the cementation matrix is in the range of 18-20 MPa (28 d); the loading of the spent IER in the cement-resin matrix is over 45% and leaching rates of 137Cs, 90Sr and 60Co are 7.92×10-5, 5.7×10-6, and 1.19×10-8 cm/d. The results show that ASC cement can be a preferable cementation material for immobilization of radioactive spent IER.

  3. Ion exchange of ammonium in natural and synthesized zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yifei [College of Biology and Chemical Engineering, Jiaxing University, Jiaxin, Zhejiang 314001 (China); Department of Chemistry, XiXi Campus, Zhejiang University, Hangzhou, Zhejiang 310028 (China)], E-mail:; Lin Feng [Department of Chemistry, XiXi Campus, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Pang Wenqin [Department of Chemistry, State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, Changchun, Jilin 130023 (China)


    In this study, zeolite Na-P and Na-Y was prepared by hydrothermal treatment of the Chinese natural clinoptilolite with NaOH. The ion exchange of NH{sub 4}{sup +} into the three zeolites in the temperature range of 288-333 K was also investigated, and the thermodynamic parameters were calculated. The selectivity sequence for NH{sub 4}{sup +} entering the sodium form of the three materials was Na-clinoptilolite > Na-Y > Na-P, as indicated by values of {delta}G{sup o}. The results demonstrated that the Si/Al molar ratio of zeolites determined the selectivity for NH{sub 4}{sup +}.

  4. Investigation of the Ion-Exchange Behavior of Zeolite Y in the Presence of Resin

    Institute of Scientific and Technical Information of China (English)

    Zhang Yi; Zheng Jinyu; Liu Zhongqing; Gao Xiuzhi; Luo Yibin; Zong Baoning


    Ion-exchange process of zeolite Y using ammonium-type resin as an exchange reagent was successfully carried out. The effect of temperature, space velocity and ion concentration on the breakthrough curves was carefully investigated. At the ifrst exchange section, the maximum proportion of qualiifed zeolites (QR) was obtained at a temperature of 70℃, a weight hourly space velocity of 0.61 h-1, and an ion concentration of 197 mg/L. The minimum length of mass-transfer zone (MTZ) of the resin bed was achieved at a temperature of 70℃, a space velocity of 0.61 h-1, and an ion concentration of 423 mg/L. At the second exchange section, the length of MTZ of the resin bed was signiifcantly increased, and the exchange of Na+ions contained in zeolite Y was more dififcult than that achieved at the ifrst exchange section. In both the ifrst and the second exchange sections, the zeolite Y subjected to ion exchange with the resin maintained the similar physical and chemi-cal properties as compared to those exchanged by the conventional approaches, but the zeolite Y, which was obtained after ion exchange, contained a signiifcantly lower content of Na2O.

  5. Zinc--bromide secondary cell. [C anode, C or Zr cathode with ion exchange diaphragm between

    Energy Technology Data Exchange (ETDEWEB)

    Leddy, J.J.; Gritzner, G.


    A zinc-bromine secondary cell is divided into two compartments by an ion exchange diaphragm. The electrolyte system includes an essentially bromide-ion-free, aqueous solution containing a zinc ion as an anolyte and a bromide ion containing catholyte. A method of operating the cell is disclosed. 2 figures, 2 tables. (auth)

  6. Effects of ion exchange on stream solute fluxes in a basin receiving highway deicing salts (United States)

    Shanley, J.B.


    At Fever Brook, a 1260-ha forested basin in central Massachusetts, highway deicing salt application increased the solute flux in streamflow by 120% above background flux (equivalent basis) during a 2-yr period. Attempts to isolate the nonsalt component of stream solute fluxes have commonly subtracted salt contributions based on the net Cl flux (Cl output in streamflow minus Cl input in precipitation). In these studies, any net Na flux in excess of the amount needed to balance the net Cl flux has been attributed to weathering. At Fever Brook, however, the net output of Na was less than the net output of Cl, suggesting a loss of Na within the basin. The Na sink was inferred to be cation exchange of Na for Ca and Mg in the soil. A method was developed to quantify the exchange based on a Na budget, which included an independent estimate of the Na flux from weathering. The amount of exchange was apportioned to Ca and Mg based on their relative concentrations in the stream. The background fluxes of Ca and Mg (i.e., those that would occur in the absence of deicing salts) were calculated by subtracting the amounts from ion exchange plus the much smaller direct contributions in deicing salts from the observed fluxes. Ion exchange and direct salt contributions increased the net output fluxes of Ca and Mg, each by 44% above background. In basins that receive deicing salts, failure to account for cation exchange thus may result in an underestimate of the flux of Na from weathering and overestimates of the fluxes of Ca and Mg from weathering.

  7. Ion beam analysis fundamentals and applications

    CERN Document Server

    Nastasi, Michael; Wang, Yongqiang


    Ion Beam Analysis: Fundamentals and Applications explains the basic characteristics of ion beams as applied to the analysis of materials, as well as ion beam analysis (IBA) of art/archaeological objects. It focuses on the fundamentals and applications of ion beam methods of materials characterization.The book explains how ions interact with solids and describes what information can be gained. It starts by covering the fundamentals of ion beam analysis, including kinematics, ion stopping, Rutherford backscattering, channeling, elastic recoil detection, particle induced x-ray emission, and nucle

  8. Theoretical investigations on optical properties of magneto-optical thin film on ion-exchanged glass waveguide (United States)

    Hocini, Abdesselam; Bouras, Mounir; Amata, Hadi


    In this work, we report on the theoretical study of magneto-optical waveguides on an ion-exchanged glass waveguide, this latter is made by sol-gel process and doped with magnetic nanoparticles with two kinds of matrix (SiO2/TiO2 and SiO2/ZrO2). The mode propagation and the lateral light confinement for both polarizations TE and TM are simulated using software based on a film mode matching method. We propose from those results magneto-optical waveguides on ion-exchanged glass waveguide geometries for optical integrated applications.

  9. Metal nanoparticles immobilized on ion-exchange resins:A versatile and effective catalyst platform for sustainable chemistry

    Institute of Scientific and Technical Information of China (English)

    Francesca Liguori; Carmen Moreno-Marrodan; Pierluigi Barbaro


    This paper reviews the recent achievements in the immobilization of metal nanoparticles on ion-exchange resins and the related catalytic application. The focus is on the production processes for fine and commodity chemicals for which a low environmental impact has been demonstrated. The most significant papers that appeared in the literature from January 2010 to July 2014 have been covered. Their uses in unselective processes, bulk chemicals production, fuel cells compo-nents, as well as the use of metal-free ion-exchange resins in acid/base-catalysed reactions, were not included.

  10. Evaluation of the thermal effect on separation selectivity in anion-exchange processes using superheated water ion-exchange chromatography. (United States)

    Shibukawa, Masami; Taguchi, Akihiko; Suzuki, Yusuke; Saitoh, Kazunori; Hiaki, Toshihiko; Yarita, Takashi


    The thermal effect on retention and separation selectivity of inorganic anions and aromatic sulfonate ions in anion-exchange chromatography is studied on a quaternized styrene-divinylbenzene copolymer anion-exchange column in the temperature range of 40-120 °C using superheated water chromatography. The selectivity coefficient for a pair of identically charged anions approaches unity as temperature increases provided the ions have the same effective size, such that the retention of an analyte ion decreases with an increase in temperature when the analyte ion has stronger affinity for the ion-exchanger than that of the eluent counterion, whereas it increases when it has weaker affinity. The change in anion-exchange selectivity with temperature observed with superheated water chromatography has been discussed on the basis of the effect of temperature on hydration of the ions. At elevated temperatures, especially in superheated water, the electrostatic interaction or association of the ions with the fixed ion in the resin phase becomes a predominant factor resulting in a different separation selectivity from that obtained at ambient temperature.

  11. Multicusp sources for ion beam lithography applications

    Energy Technology Data Exchange (ETDEWEB)

    Leung, K.N.; Herz, P.; Kunkel, W.B.; Lee, Y.; Perkins, L.; Pickard, D.; Sarstedt, M.; Weber, M.; Williams, M.D.


    Application of the multicusp source for Ion Projection Lithography is described. It is shown that the longitudinal energy spread of the positive ions at the extraction aperture can be reduced by employing a magnetic filter. The advantages of using volume-produced H{sup {minus}} ions for ion beam lithography is also discussed.

  12. Multicusp sources for ion beam lithography applications

    Energy Technology Data Exchange (ETDEWEB)

    Leung, K.N.; Herz, P.; Kunkel, W.B.; Lee, Y.; Perkins, L.; Pickard, D.; Sarstedt, M.; Weber, M.; Williams, M.D. [Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720 (United States)


    Application of the multicusp source for ion projection lithography is described. It is shown that the longitudinal energy spread of the positive ions at the extraction aperture can be reduced by employing a magnetic filter. The advantages of using volume-produced H{sup {minus}} ions for ion beam lithography are also discussed. {copyright} {ital 1995} {ital American} {ital Vacuum} {ital Society}

  13. Modelling the ion-exchange equilibrium in nanoporous materials

    Directory of Open Access Journals (Sweden)

    M. Lukšič


    Full Text Available Distribution of a two component electrolyte mixture between the model adsorbent and a bulk aqueous electrolyte solution was studied using the replica Ornstein-Zernike theory and the grand canonical Monte Carlo method. The electrolyte components were modelled to mimic the HCl/NaCl and HCl/CaCl2 mixtures, respectively. The matrix, invaded by the primitive model electrolyte mixture, was formed from monovalent negatively charged spherical obstacles. The solution was treated as a continuous dielectric with the properties of pure water. Comparison of the pair distribution functions (obtained by the two methods between the various ionic species indicated a good agreement between the replica Ornstein-Zernike results and machine calculations. Among thermodynamic properties, the mean activity coefficient of the invaded electrolyte components was calculated. Simple model for the ion-exchange resin was proposed. The selectivity calculations yielded qualitative agreement with the following experimental observations: (i selectivity increases with the increasing capacity of the adsorbent (matrix concentration, (ii the adsorbent is more selective for the ion having higher charge density if its fraction in mixture is smaller.

  14. Recovery of tetrachloroaurate through ion exchange with Dowex 11 resin

    Directory of Open Access Journals (Sweden)

    Alguacil, F. J.


    Full Text Available The recovery of the tetrachloroaurate complex by the anionic ion exchange resin Dowex 11 has been studied. The kinetics of gold adsorption were dependent of both gold and resin concentrations and temperature. The adsorption isotherm can be described by the expression Q = kCn. The loaded resin could be eluted by an acidic thiourea solution at 20°C. After several adsorption-elution cycles there is not any apparent loss in the adsorption properties of the resin.

    Se estudia la recuperación del ion tetracloroaurato mediante la resina aniónica Dowex 11. La extracción de oro depende tanto de las concentraciones del metal y la resina como de la temperatura. La isoterma de adsorción responde a la ecuación Q = kCn. La resina cargada con oro puede ser eluida con una disolución acida de tiourea a 20°C. Después de varios ciclos de adsorción-desorción no hay pérdida de carga por parte de la resina.

  15. 离子膜在填料型微生物燃料电池中的应用%Application of Ion Exchange Membrane in Packing-type Microbial Fuel Cell

    Institute of Scientific and Technical Information of China (English)

    王波; 梁鹏; 袁璐璐; 黄霞; 张传义


    Different inexpensive ion exchange membranes were applied as separation materials in packing-type microbial fuel cells ( MFC). The internal resistances, polarization curves, power density, membrane resistance as well as diffusions of organic matter and oxygen were investigated. Compared to MFC with cation exchange membrane as separation material, MFC with anion exchange membrane as separation material had lower internal resistance and higher power density (up to 2.4 W/m2). The internal resistance and membrane resistance of MFC with anion exchange membrane changed less during long-term operation. After long-term operation, cation exchange membranes deposited more salts on the cathode side, which was not observed on the anion exchange membrane. Anion exchange membrane had lower rejection efficiency for NaAc than cation exchange membrane. There was little difference in the rejection of glucose between the anion and cation exchange membranes. CM3 was the best in the rejection of oxygen and organic matter.%利用不同廉价离子交换膜作为填料型微生物燃料电池(MFC)的分隔材料,考察其运行情况,表征其内阻、极化曲线、功率密度、膜面电阻以及对有机物和氧气的扩散系数.结果表明:相比以阳离子交换膜作为分隔材料的MFC(CMFC),以阴离子交换膜作为分隔材料的MFC(AMFC)内阻更低,功率密度更高,最大功率密度可达2.4 W/m2.在长期运行过程中AMFC的内阻及膜面电阻变化均较小.长期运行后,阳离子交换膜靠着阴极侧沉积较多的盐类,而阴离子交换膜则未观测到.阴离子交换膜对NaAc的阻隔效果较阳离子交换膜差,而对葡萄糖的阻隔效果与阳离子交换膜相差不大,阻隔氧和有机物最好的为CM3型阳离子膜.

  16. Er3+/Yb3+ Codoped Phosphate Glass for Ion-Exchanged Planar Waveguide Amplifiers

    Institute of Scientific and Technical Information of China (English)

    Shilong Zhao; Baoyu Chen; Zhuping Liu; Lili Hu


    A novel Er3+/Yb3+ codoped phosphate glass was developed, which exhibited good chemical durability in molten salts and excellent spectroscopic properties. Preliminary results of ion exchange at different time and temperature, and with varying melt concentrations indicated that WM4 glass was suitable for ion-exchange experiments and there was no deterioration of surface quality.

  17. Er~(3+)/Yb~(3+) Codoped Phosphate Glass for Ion-Exchanged Planar Waveguide Amplifiers

    Institute of Scientific and Technical Information of China (English)


    A novel Er3+/Yb3+ codoped phosphate glass was developed, which exhibited good chemical durability in molten salts and excellent spectroscopic properties. Preliminary results of ion exchange at different time and temperature, and with varying melt concentrations indicated that WM4 glass was suitable for ion-exchange experiments and there was no deterioration of surface quality.

  18. Modeling of Crystalline Silicotitanate Ion Exchange Columns Using Experimental Data from SRS Simulated Waste

    Energy Technology Data Exchange (ETDEWEB)

    Walker, D.D.


    Non-elutable ion exchange using crystalline silicotitanate is being considered for removing cesium from Savannah River Site radioactive waste. The construction cost of this process depends strongly on the size of the ion exchange column required to meet product specifications.

  19. Selective ion exchange recovery of rare earth elements from uranium mining solutions (United States)

    Rychkov, Vladimir N.; Kirillov, Evgeny V.; Kirillov, Sergey V.; Bunkov, Grigory M.; Mashkovtsev, Maxim A.; Botalov, Maxim S.; Semenishchev, Vladimir S.; Volkovich, Vladimir A.


    A comparative study of rare earth, ferric and aluminum ions ion exchange behavior on gel sulfonated p;olystyrene cation exchange resins depending on the degree of the matrix cross-linking and pH of the solution is presented. Selective ion exchange of REEs is possible at the pH range of 1.5-2.0 using strongly acidic cation exchange resins containing more than 8 % of DVB. The preliminary results of testing the efficiency of REEs recovery from the industrial uranium underground leaching solutions are also presented.

  20. Technological aspects of vegetable oils epoxidation in the presence of ion exchange resins: a review

    Directory of Open Access Journals (Sweden)

    Milchert Eugeniusz


    Full Text Available A review paper of the technology basics of vegetable oils epoxidation by means of peracetic or performic acid in the presence of acidic ion exchange resins has been presented. The influence of the following parameters: temperature, molar ratio of acetic acid and hydrogen peroxide to ethylenic unsaturation, catalyst loading, stirring intensity and the reaction time on a conversion of ethylenic unsaturation, the relative percentage conversion to oxirane and the iodine number was discussed. Optimal technological parameters, mechanism of epoxidation by carboxylic peracids and the possibilities of catalyst recycling have been also discussed. This review paper shows the application of epoxidized oils.

  1. Electrical Resistance and Transport Numbers of Ion-Exchange Membranes Used in Electrodialytic Soil Remediation

    DEFF Research Database (Denmark)

    Hansen, Henrik; Ottosen, Lisbeth M.; Villumsen, Arne


    causes damage to the membrane. This work presents the result from transport number and electrical resistance measurements done on four sets of ion-exchange membranes (Ionics, Inc. CR67 HMR412 cation-exchange membranes and Ionics, Inc. AR204 SXZR anion-exchange membranes), which have been used in four......Electrodialytic soil remediation is a recently developed method to decontaminate heavy metal polluted soil using ion-exchange membranes. In this method one side of the ion-exchange membrane is in direct contact with the polluted soil. It is of great importance to know if this contact with the soil...... different electrodialytic soil remediation experiments. The experiments showed that after the use in electrodialytic soil remediation, the ion-exchange membranes had transport numbers in the same magnitude as new membranes. The electrical resistance for six membranes did not differ from that of new...

  2. Nonlinear Inverse Problem for an Ion-Exchange Filter Model: Numerical Recovery of Parameters

    Directory of Open Access Journals (Sweden)

    Balgaisha Mukanova


    Full Text Available This paper considers the problem of identifying unknown parameters for a mathematical model of an ion-exchange filter via measurement at the outlet of the filter. The proposed mathematical model consists of a material balance equation, an equation describing the kinetics of ion-exchange for the nonequilibrium case, and an equation for the ion-exchange isotherm. The material balance equation includes a nonlinear term that depends on the kinetics of ion-exchange and several parameters. First, a numerical solution of the direct problem, the calculation of the impurities concentration at the outlet of the filter, is provided. Then, the inverse problem, finding the parameters of the ion-exchange process in nonequilibrium conditions, is formulated. A method for determining the approximate values of these parameters from the impurities concentration measured at the outlet of the filter is proposed.

  3. Application of MIEX-DOC(R) Ion Exchange Resin in Arsenic Removal from Drinking Water%MIEX-DOC(R)离子交换树脂的饮用水除砷研究

    Institute of Scientific and Technical Information of China (English)

    王鸣涛; 李腾; 朱迟; 赵良元; 蒋金辉; 杨劭


    The performance of MIEX-DOC(R) Ion exchange resin in the arsenic removal from drinking water was investigated, including the removal capacity for arsenic,the removal capability for As(Ⅲ) and As(V),and the effects of different ions and pH values on removal capabilities for As( Ⅲ) and As( V ). The result showed that MIEX-DOC(R) Resin's removal capacity for arsenic was about 0. 0051 mg (R) mL-l ,and its capabilities of removing As(Ⅲ) and As(V) showed no significance (P>0. 05). Different ions showed significantly negative or positive effect on the arsenic removal of MIEX-DOC(R) Resin. pH Value also could greatly affect the arsenic removal, especially for As (Ⅲ), however, the arsenic removal was kept above 50% at the initial concentration of 0.1 mg (R) L-1. The field experiment showed that, by application of MIEX-DOC(R) Resin under the concentration condition of around 10 mg (R) L-1 ,the arsenic concentration decreased to below 0. 05 mg (R) L-1, which reached the (GB 5749 - 2006) on the rural small-scale centralized water supply and decentralized water supply. The localized equipment using MIEX-DOC(R) Resin was the same as the imported equipment in effeciency of arsenic removal,but cheaper in the cost. The running cost was 0. 56 Yuan per ton water for the localized equipment. In consequence,MIEX-DOC(R) Resin has a significant potential in arsenic removal and can be applied to the China's countryside areas suffered from the high-arsenic drinking water.%对新型阴离子交换树脂MIEX-DOC(R)的除砷性能进行了研究,考察了该树脂除砷容量、对三价砷[As(Ⅲ)]和五价砷[As(Ⅴ)]的去除能力、不同离子和水体pH值对树脂除砷[包括As(Ⅲ)和As(Ⅴ)]效率的影响.结果表明,MIEX-DOC(R)树脂对人工配制高砷水(0.1 mg·L-1)的除砷容量约为0.0051 mg·mL-1;对As(Ⅲ)和As(Ⅴ)的去除能力相当;常见的共存离子对树脂除砷效率有抑制或促进影响;不同pH值下,MIEX-DOC(R)树脂除砷效率不同,但对0

  4. Low loss two-step ion-exchanged waveguides with high surface refractive index (United States)

    Hassanzadeh, Abdollah; Mittler, Silvia


    Two-step ion-exchanged waveguides with high surface refractive indices are fabricated under a variety of conditions. By modifying the conventional two-step ion exchange, the losses and the effective diffusion depth can be decreased without a significant effect on the surface refractive index. The influence of the first step, K+-Na+ ion exchange, performed time dependably on the surface refractive index change is investigated. Energy-dispersive x-ray spectroscopy is performed to establish the diffusion profiles of various ions.

  5. Ion Mobility Spectrometry-Hydrogen Deuterium Exchange Mass Spectrometry of Anions: Part 1. Peptides to Proteins (United States)

    Donohoe, Gregory C.; Khakinejad, Mahdiar; Valentine, Stephen J.


    Ion mobility spectrometry (IMS) coupled with hydrogen deuterium exchange (HDX)-mass spectrometry (MS) has been used to study the conformations of negatively-charged peptide and protein ions. Results are presented for ion conformers of angiotensin 1, a synthetic peptide (SP), bovine insulin, ubiquitin, and equine cytochrome c. In general, the SP ion conformers demonstrate a greater level of HDX efficiency as a greater proportion of the sites undergo HDX. Additionally, these ions exhibit the fastest rates of exchange. Comparatively, the angiotensin 1 ions exhibit a lower rate of exchange and HDX level presumably because of decreased accessibility of exchange sites by charge sites. The latter are likely confined to the peptide termini. Insulin ions show dramatically reduced HDX levels and exchange rates, which can be attributed to decreased conformational flexibility resulting from the disulfide bonds. For the larger ubiquitin and protein ions, increased HDX is observed for larger ions of higher charge state. For ubiquitin, a conformational transition from compact to more elongated species (from lower to higher charge states) is reflected by an increase in HDX levels. These results can be explained by a combination of interior site protection by compact conformers as well as decreased access by charge sites. The elongated cytochrome c ions provide the largest HDX levels where higher values correlate with charge state. These results are consistent with increased exchange site accessibility by additional charge sites. The data from these enhanced IMS-HDX experiments are described in terms of charge site location, conformer rigidity, and interior site protection.

  6. Overloading ion-exchange membranes as a purification step for monoclonal antibodies


    Brown, Arick; Bill, Jerome; Tully, Timothy; Radhamohan, Asha; Dowd, Chris


    The present study examined the overloading of ion-exchange membrane adsorbers, a form of frontal chromatography, as the final purification step in the production of mAbs (monoclonal antibodies) produced from CHO (Chinese-hamster ovary) cells. Preferential binding of impurities over antibody product was exploited using commercially available cation- and anion-exchange membranes. Three different antibody feedstreams previously purified over Protein A and ion-exchange column chromatography were ...

  7. Application of ion-exchange cartridge clean-up in food analysis. VI. Determination of six penicillins in bovine tissues by liquid chromatography-electrospray ionization tandem mass spectrometry. (United States)

    Ito, Yuko; Goto, Tomomi; Oka, Hisao; Matsumoto, Hiroshi; Takeba, Kazue


    A multiresidue analytical method was developed for the quantification of benzylpenicillin (PCG), phenoxymethylpenicillin (PCV), oxacillin (MPIPC), cloxacillin (MCIPC), nafcillin (NFPC) and dicloxacillin (MDIPC) in bovine tissues using liquid chromatography- electrospray ionization tandem mass spectrometry (LC-ESI MS/MS) with a multiple reaction monitoring technique. Using the deuterated PCG and NFPC as internal standard was effective for improvement of repeatability and accuracy. We chose [M-H-141]- as a monitor ion of MRM analysis and [M-H]- as a precursor ion for each penicillin. Combination of an ion-exchange cartridge clean-up and ion-pair LC enable us to determine the residual penicillins using the standard curves made from standard solutions without the influence of sample matrix on the MS. The average recoveries of PCG, PCV, MPIPC, MCIPC, NFPC and MDIPC from bovine liver, kidney and muscle at the same concentrations as the tolerance levels of PCG (50 microg/kg) ranged from 77 to 101% with the coefficients of variation ranging from 0.7 to 4.2% (n = 5). The limits of quantification for the six penicillins were 2-10 microg/kg in bovine muscle, liver and kidney (S/N ratio >10).

  8. Revised Thermal Analysis of LANL Ion Exchange Column

    Energy Technology Data Exchange (ETDEWEB)

    Laurinat, J


    This document updates a previous calculation of the temperature distributions in a Los Alamos National Laboratory (LANL) ion exchange column.1 LANL operates two laboratory-scale anion exchange columns, in series, to extract Pu-238 from nitric acid solutions. The Defense Nuclear Facilities Safety Board has requested an updated analysis to calculate maximum temperatures for higher resin loading capacities obtained with a new formulation of the Reillex HPQ anion exchange resin. The increased resin loading capacity will not exceed 118 g plutonium per L of resin bed. Calculations were requested for normal operation of the resin bed at the minimum allowable solution feed rate of 30 mL/min and after an interruption of flow at the end of the feed stage, when one of the columns is fully loaded. 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. At low temperatures, resin bed temperatures increase primarily due to decay heat. At {approx}70 C a Low Temperature Exotherm (LTE) resulting from the reaction between 8-12 M HNO{sub 3} and the resin has been observed. The LTE has been attributed to an irreversible oxidation of pendant ethyl benzene groups at the termini of the resin polymer chains by nitric acid. The ethyl benzene groups are converted to benzoic acid moities. The resin can be treated to permanently remove the LTE by heating a resin suspension in 8M HNO{sub 3} for 30-45 minutes. No degradation of the resin performance is observed after the LTE removal treatment. In fact, heating the resin in boiling ({approx}115-120 C) 12 M HNO{sub 3} for 3 hr displays thermal stability analogous to resin that has been treated to remove the LTE. The analysis is based on a previous study of the SRS Frames Waste Recovery (FWR) column, performed in support of the Pu-238 production campaign for NASA's Cassini mission. In that study, temperature transients

  9. Praseodymium ion doped phosphate glasses for integrated broadband ion-exchanged waveguide amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Shen, L.F. [School of Textile and Material Engineering, Dalian Polytechnic University, Dalian 116034 (China); Department of Electronic Engineering, City University of Hong Kong, Kowloon, Hong Kong (China); Chen, B.J. [Department of Electronic Engineering, City University of Hong Kong, Kowloon, Hong Kong (China); Lin, H., E-mail: [School of Textile and Material Engineering, Dalian Polytechnic University, Dalian 116034 (China); Department of Electronic Engineering, City University of Hong Kong, Kowloon, Hong Kong (China); Pun, E.Y.B. [Department of Electronic Engineering, City University of Hong Kong, Kowloon, Hong Kong (China)


    Highlights: • Effective near-infrared emission (1380-1525 nm) is observed in Pr{sup 3+}-doped phosphate glasses. • Effective bandwidth of {sup 1}D{sub 2} → {sup 1}G{sub 4} transition emission is obtained to be 124 nm. • Channel waveguides have been fabricated by K{sup +}-Na{sup +} ion-exchange method. • Pr{sup 3+}-doped phosphate glasses are promising in developing integrated broadband waveguide amplifier. - Abstract: Effective near-infrared emission covering the fifth optical telecommunication window (1380-1525 nm) has been observed in Pr{sup 3+}-doped phosphate (NMAP) glasses. Judd-Ofelt parameters Ω{sub 2} (6.38 × 10{sup −20} cm{sup 2}), Ω{sub 4} (20.30 × 10{sup −20} cm{sup 2}) and Ω{sub 6} (0.40 × 10{sup −20} cm{sup 2}) indicate a high inversion asymmetrical and strong covalent environment in the optical glasses. The effective bandwidth (Δλ{sub eff}) of the corresponding {sup 1}D{sub 2} → {sup 1}G{sub 4} transition emission is obtained to be 124 nm, and the maximum stimulated emission cross-section (σ{sub em-max}) at 1468 nm is derived to be 1.14 × 10{sup −20} cm{sup 2}. Channel waveguide was fabricated successfully by K{sup +}-Na{sup +} ion-exchange method with mode field diameter of 8.8 μm in the horizontal direction and 6.7 μm in the vertical direction. Broad effective bandwidth, large emission cross-section and perfect thermal ion-exchangeability indicate that Pr{sup 3+}-doped NMAP phosphate glasses are promising in developing integrated broadband waveguide amplifier, especially operating at E- and S-bands which belong to the fifth optical telecommunication window.

  10. Multivariate analysis of Ion Beam Induced Luminescence spectra of irradiated silver ion-exchanged silicate glasses (United States)

    Valotto, Gabrio; Quaranta, Alberto; Cattaruzza, Elti; Gonella, Francesco; Rampazzo, Giancarlo

    A multivariate analysis is used for the identification of the spectral features in Ion Beam Induced Luminescence (IBIL) spectra of soda-lime silicate glasses doped with silver by Ag+-Na+ ion exchange. Both Principal Component Analysis and multivariate analysis were used to characterize time-evolving IBIL spectra of Ag-doped glasses, by means of the identification of the number and of the wavelength positions of the main luminescent features and the study of their evolution during irradiation. This method helps to identify the spectral features of the samples spectra, even when partially overlapped or less intense. This analysis procedure does not require additional input such as the number of peaks.

  11. The selective separation of Cs and Sr ion on the inorganic ion-exchanger zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hun Hwee; Min, Byeog Heon [Hoseo University, Taegu (Korea)


    This study shows the selective separation of Cs and Sr ion on the inorganic ion-exchanger zeolites such as clinoptilolite, Y-type CBV760, CBV780 and A-type 3A. The selective separation of Cs and Sr on these zeolites was examined using batch and continuous column experiments. For the selective separation of Cs and Sr from a synthetic wastewater, adsorption rate of Cs increased in the order, clinoptilolite> 3A>> CBV760> CBV780, adsorption rate of Sr increased in the other, 3A>> clinoptilolite> CBV760> CBV780. For the clinoptilolite, the adsorption rate of Cs reached about 96 {approx} 98% within 3h. The adsorption rate of Sr on 3A reached about 99% within 3h. (author). 40 refs., 27 figs., 4 tabs.

  12. Electrically controlled exchange bias for spintronic applications (United States)

    He, Xi; Polisetty, Srinivas; Binek, Christian


    Electrically controlled exchange bias (EB) is proposed for novel spintronic applications [1]. Basic effects of electrically controlled EB and its magnetoelectric (ME) switching are studied in a Cr2O3(111)/(Co/Pt)3 heterostructure. Exchange coupling between the ME antiferromagnet Cr2O3 and a ferromagnetic CoPt multilayer exhibits perpendicular EB. The latter is controlled by applied axial electric fields inducing excess magnetization at the interface. The enhancement of this hitherto weak tuning effect is explored when replacing ME bulk pinning systems by epitaxal thin films. Recently, the sign of the EB field has been tuned via field cooling the system in either parallel or antiparallel axial magnetic and electric fields [2].Here, the crossover from bulk to thin film ME pinning systems is studied and spintronic applications are suggested based on the electrically controlled EB. Pure voltage control of magnetic configurations of tunneling magnetoresistance spin valves is proposed as an alternative to current-induced magnetization switching. In addition we suggest an XOR operation realized in a MEally pinned giant magneto resistance structure. [1] Ch. Binek, B.Doudin, J. Phys. Condens. Matter 17, L39 (2005). [2] P. Borisov et al., Phys. Rev. Lett. 94, 117203 (2005).

  13. Enhanced performance of anion exchange membranes via crosslinking of ion cluster regions for fuel cells (United States)

    Lai, Ao Nan; Guo, Dong; Lin, Chen Xiao; Zhang, Qiu Gen; Zhu, Ai Mei; Ye, Mei Ling; Liu, Qing Lin


    Development of anion exchange membranes (AEMs) with high hydroxide conductivity, good dimensional and alkaline stabilities is still a challenge for the practical application of AEM fuel cells. In this study, we report a new strategy to prepare high-performance AEMs with crosslinked ionic regions. A series of phenolphthalein-containing poly(arylene ether sulfone)s crosslinked AEMs was synthesized by grafting ion groups selectively and densely on the phenolphthalein units to form ion clusters that are further crosslinked to generate the hydrophilic ionic regions. The crosslinking reaction not only improved the dimensional stability of the AEMs, but also increased the aggregation of the ion clusters leading to the formation of hydrophilic/hydrophobic phase-separated morphology and ion-conducting channels. As a result, enhancements in both ion conductivity and dimensional stability can be achieved. The crosslinked AEMs showed high hydroxide conductivities in the range of 52.2-143.4 mS cm-1 from 30 to 80 °C and a superb ratio of relative conductivity to relative swelling at 80 °C. Furthermore, the crosslinked AEMs also exhibited good mechanical properties, thermal and alkaline stabilities and desirable single cell performance. This work presents a promising strategy for the synthesis of high-performance AEMs for fuel cells.

  14. Ion-exchange and hydrophobic interactions affecting selectivity for neutral and charged solutes on three structurally similar agglomerated ion-exchange and mixed-mode stationary phases. (United States)

    Kazarian, Artaches A; Taylor, Mark R; Haddad, Paul R; Nesterenko, Pavel N; Paull, Brett


    The nature and extent of mixed-mode retention mechanisms evident for three structurally related, agglomerated, particle-based stationary phases were evaluated. These three agglomerated phases were Thermo Fisher ScientificIon PacAS11-HC - strong anion exchange, Thermo Fisher Scientific IonPac CS10--strong cation-exchange PS-DVB, and the Thermo Fisher Scientific Acclaim Trinity P1silica-based substrate, which is commercially marketed as a mixed-mode stationary phase. All studied phases can exhibit zwitterionic and hydrophobic properties, which contribute to the retention of charged organic analytes. A systematic approach was devised to investigate the relative ion-exchange capacities and hydrophobicities for each of the three phases, together with the effect of eluent pH upon selectivity, using a specifically selected range of anionic, cationic and neutral aromatic compounds. Investigation of the strong anion-exchange column and the Trinity P1 mixed-mode substrate, in relation to ion-exchange capacity and pH effects, demonstrated similar retention behaviour for both the anionic and ampholytic solutes, as expected from the structurally related phases. Further evaluation revealed that the ion-exchange selectivity of the mixed-mode phase exhibited properties similar to that of the strong anion-exchange column, with secondary cation-exchange selectivity, albeit with medium to high anion-exchange and cation-exchange capacities, allowing selective retention for each of the anionic, cationic and ampholytic solutes. Observed mixed-mode retention upon the examined phases was found to be a sum of anion- and cation-exchange interactions, secondary ion-exchange and hydrophobic interactions, with possible additional hydrogen bonding. Hydrophobic evaluation of the three phases revealed logP values of 0.38-0.48, suggesting low to medium hydrophobicity. These stationary phases were also benchmarked against traditional reversed-phase substrates namely, octadecylsilica YMC-Pac Pro C18

  15. A surface complexation and ion exchange model of Pb and Cd competitive sorption on natural soils (United States)

    Serrano, Susana; O'Day, Peggy A.; Vlassopoulos, Dimitri; García-González, Maria Teresa; Garrido, Fernando


    The bioavailability and fate of heavy metals in the environment are often controlled by sorption reactions on the reactive surfaces of soil minerals. We have developed a non-electrostatic equilibrium model (NEM) with both surface complexation and ion exchange reactions to describe the sorption of Pb and Cd in single- and binary-metal systems over a range of pH and metal concentration. Mineralogical and exchange properties of three different acidic soils were used to constrain surface reactions in the model and to estimate surface densities for sorption sites, rather than treating them as adjustable parameters. Soil heterogeneity was modeled with >FeOH and >SOH functional groups, representing Fe- and Al-oxyhydroxide minerals and phyllosilicate clay mineral edge sites, and two ion exchange sites (X - and Y -), representing clay mineral exchange. An optimization process was carried out using the entire experimental sorption data set to determine the binding constants for Pb and Cd surface complexation and ion exchange reactions. Modeling results showed that the adsorption of Pb and Cd was distributed between ion exchange sites at low pH values and specific adsorption sites at higher pH values, mainly associated with >FeOH sites. Modeling results confirmed the greater tendency of Cd to be retained on exchange sites compared to Pb, which had a higher affinity than Cd for specific adsorption on >FeOH sites. Lead retention on >FeOH occurred at lower pH than for Cd, suggesting that Pb sorbs to surface hydroxyl groups at pH values at which Cd interacts only with exchange sites. The results from the binary system (both Pb and Cd present) showed that Cd retained in >FeOH sites decreased significantly in the presence of Pb, while the occupancy of Pb in these sites did not change in the presence of Cd. As a consequence of this competition, Cd was shifted to ion exchange sites, where it competes with Pb and possibly Ca (from the background electrolyte). Sorption on >SOH

  16. 12th International Symposium on Electron Beam Ion Sources and Traps and Their Applications

    CERN Document Server

    Schwarz, Stefan; Baumann, Thomas M


    The EBIST symposia date back to 1977 and have taken place every 3 to 4 years to specifically discuss progress and exchange ideas in the design, development, applications of electron beam ion sources and traps, and the physics with highly charged ions. The topics to be covered in 2014 are: - Progress and status of EBIS/T facilities, - Atomic spectroscopy of highly charged ions, - Charge-exchange and surface interaction with highly charged ions, - Charge breeding of stable and radioactive isotopes, - Nuclear physics with highly charged ions.

  17. A Novel Ion Exchange System to Purify Mixed ISS Waste Water Brines for Chemical Production and Enhanced Water Recovery (United States)

    Lunn, Griffin; Spencer, LaShelle; Ruby, Anna-Maria; McCaskill, Andrew


    Current International Space Station water recovery regimes produce a sizable portion of waste water brine. This brine is highly toxic and water recovery is poor: a highly wasteful proposition. With new biological techniques that do not require waste water chemical pretreatment, the resulting brine would be chromium-free and nitrate rich which can allow possible fertilizer recovery for future plant systems. Using a system of ion exchange resins we can remove hardness, sulfate, phosphate and nitrate from these brines to leave only sodium and potassium chloride. At this point modern chlor-alkali cells can be utilized to produce a low salt stream as well as an acid and base stream. The first stream can be used to gain higher water recovery through recycle to the water separation stage while the last two streams can be used to regenerate the ion exchange beds used here, as well as other ion exchange beds in the ISS. Conveniently these waste products from ion exchange regeneration would be suitable as plant fertilizer. In this report we go over the performance of state of the art resins designed for high selectivity of target ions under brine conditions. Using ersatz ISS waste water we can evaluate the performance of specific resins and calculate mass balances to determine resin effectiveness and process viability. If this system is feasible then we will be one step closer to closed loop environmental control and life support systems (ECLSS) for current or future applications.

  18. Validity of the second Fick's law for modeling ion-exchange diffusion in non-crystalline viscoelastic media (glasses) (United States)

    Tagantsev, D. K.; Ivanenko, D. V.


    It is shown that, in general case, the diffusion equation (or the second Fick's law) does not provide an adequate description of ion-exchange transport phenomena in viscoelastic media, including glassy or any other non-crystalline media. In this connection the general phenomenological model of ion-exchange diffusion in viscoelastic media has been developed. A theoretical analysis of the model shows that, in the case of a linear dependence of medium density on the concentration of diffusing ions, the necessary and sufficient condition of the absolute validity of the diffusion equation in viscoelastic media is Φ ≫ 1, where Φ = τD/τR is the dimensionless value (or criterion of similarity), with τD = L2/D being the characteristic time of diffusion and τR = η/G being the characteristic time of stress relaxation, where L, D, η, and G are the characteristic length of diffusion, the diffusivity, the viscosity, and the shear modulus, respectively. The value of 1/Φ characterizes the accuracy which is provided if the second Fick's law is used in the simulation of ion-exchange diffusion in viscoelastic media. We have demonstrated the applicability of this criterion experimentally. Our experimental studies on ion-exchange diffusion in an oxide glass (typical viscoelastic media) have shown that under the condition the Φ > 105 the experimental concentration profiles are close to those predicted by the second Fick's law to within an accuracy of 1%.

  19. Lysozyme-immobilized electrospun PAMA/PVA and PSSA-MA/PVA ion-exchange nanofiber for wound healing. (United States)

    Tonglairoum, Prasopchai; Ngawhirunpat, Tanasait; Rojanarata, Theerasak; Opanasopit, Praneet


    Abstract This research was aimed to develop the lysozyme immobilized ion-exchange nanofiber mats for wound healing. To promote the healing process, the PSSA-MA/PVA and PAMA ion-exchange nanofiber mats were fabricated to mimic the extracellular matrix structure using electrospinning process followed by thermally crosslinked. Lysozyme was immobilized on the ion-exchane nanofibers by an adsorption method. The ion-exchange nanofibers were investigated using SEM, FTIR and XRPD. Moreover, the lysozyme-immobilized ion-exchange nanofibers were further investigated for lysozyme content and activity, lysozyme release and wound healing activity. The fiber diameters of the mats were in the nanometer range. Lysozyme was gradually absorbed into the PSSA-MA/PVA nanofiber with higher extend than that is absorbed on the PAMA/PVA nanofiber and exhibited higher activity than lysozyme-immobilized PAMA/PVA nanofiber. The total contents of lysozyme on the PSSA-MA/PVA and PAMA/PVA nanofiber were 648 and 166 µg/g, respectively. FTIR and lysozyme activity results confirmed the presence of lysozyme on the nanofiber mats. The lysozyme was released from the PSSA-MA/PVA and PAMA/PVA nanofiber in the same manner. The lysozyme-immobilized PSSA-MA/PVA nanofiber mats and lysozyme-immobilized PAMA/PVA nanofiber mats exhibited significantly faster healing rate than gauze and similar to the commercial antibacterial gauze dressing. These results suggest that these nanofiber mats could provide the promising candidate for wound healing application.

  20. Ion exchange pretreatment of alkaline radwaste for cesium removal

    Energy Technology Data Exchange (ETDEWEB)

    Bibler, J.P. [Westinghouse Savannah River Co., Aiken, SC (United States). Savannah River Technology Center


    A cation exchange resin has been tested for its ability to remove the Cs ion from simulants of highly alkaline liquid nuclear wastes found at the Savannah River Site, Oak Ridge, and Hanford. The resin is a condensation polymer of the K salt of resorcinol and formaldehyde. It removes milli- and micromolar amounts of Cs{sup +} from solutions that contain as high as 11 molar Na{sup +}. Small column tests indicate that approximately 200 column volumes of SRS simulant and 205 column volumes of OR Tank 25 supernatant simulant can be processed before the resin requires regeneration. For these two wastes, a carousel arrangement of two columns in series and a third in reserve can be used effectively in a process. Hanford 101-AW simulant generates a less sharp breakthrough profile with this resin, though an operation using a maximum of three columns in series with another column off-line for regeneration would be effective if the resin beds are allowed to reach about 90% breakthrough before taking them out of service. Parameters that effect the performance of the resin with a particular feed solution are the concentrations of the two primary ions of interest, Cs{sup +} and Na{sup +}, as well as the concentrations of K{sup +} and OH{sup {minus}}. A further ramification of the hydroxide ion concentration is its role in assisting oxidation of the resin, thereby destroying its usefulness in cesium removal. Although the performance of the resin is unaffected at doses of 1 E+8 rad ionizing radiation, it shows noticeable degradation after storage for 100 hours in alkaline solutions, generating quinone and ketone groups, as determined from C-13 NMR and by an increase in total organic C content of the contacting solution. Gases detected from the radiolysis of the resin/simulant mixture are CO{sub 2} from the resin, N{sub 2}O from nitrate in the simulant, and H{sub 2} possibly from resin and simulant. Oxygen depletion in the mixture results from radiolysis and chemical degradation.

  1. Crystalline Silicotitanate Ion Exchange Support for Salt-Alternatives

    Energy Technology Data Exchange (ETDEWEB)

    Fondeur, F.F.


    The current version of crystalline silicotitanate (TAM5) is commercially available from UOP under the trade name IONSIV IE-911. TAM5 was extensively tested by several researchers and was determined as the best currently available material for removing radioisotopes from various types of nuclear wastes salt solutions stored at various DOE sites. The studies at Savannah River Technology Center (SRTC) indicated that the CST granules tend to leach into the nuclear waste simulants as it is processed by the ion exchange columns that is packed with CST granules from UOP. We, at Texas A and M University, agreed to conduct research to compliment the efforts at SRTC so that IONSIV IE-911 could be used for the treatment of nuclear waste stored at the DOE Savannah River facility. After consultation, we developed a Task Plan in January 2000. According to the agreement between Westinghouse Savannah River Company, Savannah River Technology Center, Aiken SC 29808 and, College Station, TX 77843, synthesis and the performance evaluations of crystalline silicotitanates (CST) were performed the during period of April 1 - September 30, 2000. Our main goals were delivery of a kilogram of CST (TAM5-4) synthesized at Texas A and M University in July to SRTC, performance evaluation of CST in nuclear waste simulants, and consultation mainly by telephone.

  2. Protein-surface interaction maps for ion-exchange chromatography. (United States)

    Freed, Alexander S; Cramer, Steven M


    In this paper, protein-surface interaction maps were generated by performing coarse-grained protein-surface calculations. This approach allowed for the rapid determination of the protein-surface interaction energies at a range of orientations and distances. Interaction maps of lysozyme indicated that there was a contiguous series of orientations corresponding to several adjacent preferred binding regions on the protein surface. Examination of these orientations provided insight into the residues involved in surface interactions, which qualitatively agreed with the retention data for single-site mutants. Interaction maps of lysozyme single-site mutants were also generated and provided significant insight into why these variants exhibited significant differences in their chromatographic behavior. This approach was also employed to study the binding behavior of CspB and related mutants. The results indicated that, in addition to describing general trends in the data, these maps provided significant insight into retention data of the single-site mutants. In particular, subtle retention trends observed with the K12 and K13 mutants were well-described using this interaction map approach. Finally, the number of interaction points with energies stronger than -2 kcal/mol was shown to be able to semi-quantitatively predict the behavior of most of the mutants. This rapid approach for calculating protein-surface interaction maps is expected to facilitate future method development for separating closely related protein variants in ion-exchange systems.

  3. New ion-exchanged zeolite derivatives: antifungal and antimycotoxin properties against Aspergillus flavus and aflatoxin B1 (United States)

    Savi, Geovana D.; Cardoso, Willian A.; Furtado, Bianca G.; Bortolotto, Tiago; Da Agostin, Luciana O. V.; Nones, Janaína; Torres Zanoni, Elton; Montedo, Oscar R. K.; Angioletto, Elidio


    Zeolites are microporous crystalline hydrated aluminosilicates with absorbent and catalytic properties. This material can be used in many applications in stored-pest management such as: pesticide and fertilizer carriers, animal feed additives, mycotoxin binders and food packaging materials. Herein, four 4A zeolite forms were prepared by ion-exchange and their antifungal effect against Aspergillus flavus was highlighted. Additionally, the antimycotoxin activity and the aflatoxin B1 (AFB1) adsorption capacity of these zeolites as well as their toxic effects on Artemia sp. were investigated. The ion-exchanged zeolites with Li+ and Cu2+ showed the best antifungal activity against A. flavus, including effects on conidia germination and hyphae morphological alterations. Regarding to antimycotoxin activity, all zeolite samples efficiently inhibited the AFB1 production by A. flavus. However, the ion-exchanged zeolites exhibited better results than the 4A zeolite. On the other hand, the AFB1 adsorption capacity was only observed by the 4A zeolite and zeolite-Li+. Lastly, our data showed that all zeolites samples used at effective concentrations for antifungal and antimycotoxin assays (2 mg ml-1) showed no toxic effects towards Artemia sp. Results suggest that some these ion-exchanged zeolites have great potential as an effective fungicide and antimycotoxin agent for agricultural and food safety applications.

  4. Design and performance evaluation of a microfluidic ion-suppression module for anion-exchange chromatography. (United States)

    Wouters, Sam; Wouters, Bert; Jespers, Sander; Desmet, Gert; Eghbali, Hamed; Bruggink, Cees; Eeltink, Sebastiaan


    A microfluidic membrane suppressor has been constructed to suppress ions of alkaline mobile-phases via an acid-base reaction across a sulfonated poly(tetrafluoroethylene)-based membrane and was evaluated for anion-exchange separations using conductivity detection. The membrane was clamped between two chip substrates, accommodating rectangular microchannels for the eluent and regenerant flow, respectively. Additionally, a clamp-on chip holder has been constructed which allows the alignment and stacking of different chip modules. The response and efficacy of the microfluidic chip suppressor was assessed for a wide range of eluent (KOH) concentrations, using 127 and 183μm thick membranes, while optimizing the flow rate and concentration of the regenerant solution (H2SO4). The optimal operating eluent flow rate was determined at 5μL/min, corresponding to the optimal van-Deemter flow velocity of commercially-available column technology, i.e. a 0.4mm i.d.×250mm long column packed with 7.5μm anion-exchange particles. When equilibrated at 10mM KOH, a 99% decrease in conductivity signal could be obtained within 5min when applying 10mM H2SO4 regenerant at 75μL/min. A background signal as low as 1.2μS/cm was obtained, which equals the performance of a commercially-available electrolytic hollow-fiber suppressor. When increasing the temperature of the membrane suppressor from 15 to 20°C, ion suppression was significantly improved allowing the application of 75mM KOH. The applicability of the chip suppressor has been demonstrated with an isocratic baseline separation of a mixture of seven inorganic ions, yielding plate numbers between 5300 and 10,600 and with a gradient separation of a complex ion mixture.

  5. The heats of exchange of transition metal ions on the Na form of clinoptilolite (United States)

    Tarasevich, Yu. I.; Krysenko, D. A.; Polyakov, V. E.; Aksenenko, E. V.


    Direct calorimetric measurements were used to determine the heats of exchange of the Mn2+, Co2+, Cu2+, and Ni2+ cations on the Na form of clinoptilolite over the entire range of solid phase fillings with sorbed cations. In parallel, ion exchange isotherms for the systems were measured by the sorption-analytic method. The integral free energies and entropies of ion exchange were calculated. It was shown that the solution phase of the clinoptilolite-electrolyte solution two-phase system contributed significantly to the total thermodynamic characteristics of ion exchange. The differentiation of the dependence of the integral enthalpy on the degree of filling was performed to show that the clinoptilolite structure contained at least two types of exchange sites having different interaction energies with transition metal ions.

  6. Preparation and characterization of polysulfone/PEG heterogeneous ion exchange membrane for reverse electrodialysis (RED) (United States)

    Ariono, D.; Khoiruddin; Prabandari, D.; Wulandari, R.; Wenten, I. G.


    Heterogeneous cation-exchange membrane is synthesized using solution casting method. The casting solution is prepared by dispersing finely ground cation-exchange resin particles in N,N-dimethylacetamide (DMAc) solutions of polysulfone (PSf) while polyethylene glycol (PEG400) is used as a modifier. The results show that the PEG400 can increase water uptake, conductivity, and ion-exchange capacity (IEC) of the heterogeneous cation-exchange membrane due to the hydrophilic nature of PEG400. The more hydrophilic membrane results in higher water uptake and wider access for functional sites. However, when the concentration of PEG400 is increased further, the IEC and conductivity tend to decrease. This tendency is more pronounced when the ion-exchange resin particle is increased from 50 to 60%-wt. It could be attributed to the washed out of some ion-exchange particle during membrane immersion due to lower bonding between membrane matrix and the particles.


    Energy Technology Data Exchange (ETDEWEB)

    Hamm, L


    The expected performance of a proposed ion exchange column using SuperLig{reg_sign} 644 resin for the removal of cesium from Hanford high level radioactive alkaline waste is discussed. This report represents a final report on the ability and knowledge with regard to modeling the Cesium-SuperLig{reg_sign} 644 resin ion exchange system. Only the loading phase of the cycle process is addressed within this report. Pertinent bench-scale column tests and batch equilibrium experiments are addressed. The methodology employed and sensitivity analyses are also included (i.e., existing methodology employed is referenced to prior developmental efforts while updated methodology is discussed). Pilot-scale testing is not assessed since no pilot-scale testing was available at the time of this report. Column performance predictions are made considering three selected feed compositions under nominal operating conditions. The sensitivity analyses provided help to identify key parameters that aid in resin procurement acceptance criteria. The methodology and application presented within this report reflect the expected behavior of SuperLig{reg_sign} 644 resin manufactured at the production-scale (i.e, 250 gallon batch size level). The primary objective of this work was, through modeling and verification based on experimental assessments, to predict the cesium removal performance of SuperLig{reg_sign} 644 resin for application in the RPP pretreatment facility.

  8. Phosphate recovery from wastewater using engineered superparamagnetic particles modified with layered double hydroxide ion exchangers. (United States)

    Drenkova-Tuhtan, Asya; Mandel, Karl; Paulus, Anja; Meyer, Carsten; Hutter, Frank; Gellermann, Carsten; Sextl, Gerhard; Franzreb, Matthias; Steinmetz, Heidrun


    An innovative nanocomposite material is proposed for phosphate recovery from wastewater using magnetic assistance. Superparamagnetic microparticles modified with layered double hydroxide (LDH) ion exchangers of various compositions act as phosphate adsorbers. Magnetic separation and chemical regeneration of the particles allows their reuse, leading to the successful recovery of phosphate. Based upon the preliminary screening of different LDH ion exchanger modifications for phosphate selectivity and uptake capacity, MgFe-Zr LDH coated magnetic particles were chosen for further characterization and application. The adsorption kinetics of phosphate from municipal wastewater was studied in dependence with particle concentration, contact time and pH. Adsorption isotherms were then determined for the selected particle system. Recovery of phosphate and regeneration of the particles was examined via testing a variety of desorption solutions. Reusability of the particles was demonstrated for 15 adsorption/desorption cycles. Adsorption in the range of 75-97% was achieved in each cycle after 1 h contact time. Phosphate recovery and enrichment was possible through repetitive application of the desorption solution. Finally, a pilot scale experiment was carried out by treating 125 L of wastewater with the particles in five subsequent 25 L batches. Solid-liquid separation on this scale was carried out with a high-gradient magnetic filter (HGMF).

  9. Anion and cation mixed-bed ion exchange for enhanced multidimensional separations of peptides and phosphopeptides. (United States)

    Motoyama, Akira; Xu, Tao; Ruse, Cristian I; Wohlschlegel, James A; Yates, John R


    Shotgun proteomics typically uses multidimensional LC/MS/MS analysis of enzymatically digested proteins, where strong cation-exchange (SCX) and reversed-phase (RP) separations are coupled to increase the separation power and dynamic range of analysis. Here we report an on-line multidimensional LC method using an anion- and cation-exchange mixed bed for the first separation dimension. The mixed-bed ion-exchange resin improved peptide recovery over SCX resins alone and showed better orthogonality to RP separations in two-dimensional separations. The Donnan effect, which was enhanced by the introduction of fixed opposite charges in one column, is proposed as the mechanism responsible for improved peptide recovery by producing higher fluxes of salt cations and lower populations of salt anions proximal to the SCX phase. An increase in orthogonality was achieved by a combination of increased retention for acidic peptides and moderately reduced retention of neutral to basic peptides by the added anion-exchange resin. The combination of these effects led to approximately 100% increase in the number of identified peptides from an analysis of a tryptic digest of a yeast whole cell lysate. The application of the method to phosphopeptide-enriched samples increased by 94% phosphopeptide identifications over SCX alone. The lower pKa of phosphopeptides led to specific enrichment in a single salt step resolving acidic phosphopeptides from other phospho- and non-phosphopeptides. Unlike previous methods that use anion exchange to alter selectivity or enrich phosphopeptides, the proposed format is unique in that it works with typical acidic buffer systems used in electrospray ionization, making it feasible for online multidimensional LC/MS/MS applications.



    Roto, Roto; Tahir, Iqmal; Sholikhah, Umi Nur


    Synthesis of Zn-Al-SO4 hydrotalcite and its application as anion exchanger for hexacyanoferrat (II) have been studied. Synthesis of Zn-Al-SO4 hydrotalcite was carried out by stoichiometric method and hydrothermal treatment. Sulphate in hydrotalcite interlayer was exchanged by hexacyanoferrat (II) that was assumed as pollutant. Kinetics of ion exchange was also investigated. The product of ion exchange was characterized by XRD, IR spectrophotometry and atomic absorption spectrometry. Zn-Al-SO4...

  11. Intercalation of gaseous thiols and sulfides into Ag+ ion-exchanged aluminum dihydrogen triphosphate. (United States)

    Hayashi, Aki; Saimen, Hiroki; Watanabe, Nobuaki; Kimura, Hitomi; Kobayashi, Ayumi; Nakayama, Hirokazu; Tsuhako, Mitsutomo


    Ag(+) ion-exchanged layered aluminum dihydrogen triphosphate (AlP) with the interlayer distance of 0.85 nm was synthesized by the ion-exchange of proton in triphosphate with Ag(+) ion. The amount of exchanged Ag(+) ion depended on the concentration of AgNO(3) aqueous solution. Ag(+) ion-exchanged AlP adsorbed gaseous thiols and sulfides into the interlayer region. The adsorption amounts of thiols were more than those of sulfides, thiols with one mercapto group > thiol with two mercapto groups > sulfides, and depended on the amount of exchanged Ag(+) ion in the interlayer region. The thiols with one mercapto group were intercalated to expand the interlayer distance of Ag(+) ion-exchanged AlP, whereas there was no expansion in the adsorption of sulfide. In the case of thiol with two mercapto groups, there was observed contraction of the interlayer distance through the bridging with Ag(+) ions of the upper and lower sides of the interlayer region.

  12. Separation of 1,3-Propanediol from Aqueous Solutions by Ion Exchange Chromatography

    Directory of Open Access Journals (Sweden)

    Rukowicz Beata


    Full Text Available 1,3-propanediol is a promising monomer with many applications and can be produced by bioconversion of renewable resources. The separation of this product from fermentation broth is a difficult task. In this work, the application of cation exchange resin for the separation of 1,3-propanediol from model aqueous solution was examined. The best effect of separation of 1,3-propanediol from glycerol using sorption method was obtained for H+ resin form, although the observed partition coefficient of 1,3-propanediol was low. On the basis of the results of the sorption of 1,3-propanediol, the ionic forms of the resin were selected and used in the next experiments (H+, Ca2+, Ag+, Na+, Pb2+, Zn2+. The best results in ion exchange chromatography were obtained for cation exchange resin in H+ and Ca2+ form. The use of smaller particle size of resin and a longer length of the column allows to obtain better separation of mixtures.

  13. Ion Exchange Technology Development in Support of the Urine Processor Assembly (United States)

    Mitchell, Julie; Broyan, James; Pickering, Karen


    exchange resins has demonstrated that the most effective implementation for an ion exchange resin is a cartridge, or column, in which the resin is contained. Based on the results of equilibrium and sub-scale dynamic column testing, a possible solution for mitigating the calcium precipitation issue on the ISS has been identified. From an original pool of 13 ion exchange resins, two candidates have been identified that demonstrate substantial calcium removal on the sub-scale. The dramatic reduction in resin performance from published calcium uptake demonstrates the need for thorough evaluation of resins at the low pH and strong oxidizing environment present in the UPA. Chemical variations in the influent (calcium concentrations and pretreatment dosing) appear to have a noticeable impact on the calcium capacity of the resin. Low calcium concentrations and high pretreatment dosing will likely result in a decrease in calcium capacity. Conversely, low pre trea t - ment dosing will likely result in an increase in calcium capacity. In contrast, investigations at a variety of flow rates, length-to-diameter ratios, resin volumes, and flow regimes (continuous versus pulsed) show that changes in physical parameters do not have substantial impacts on resin performance in the very low specific velocity ranges of interest. This result is particularly useful because most commercial applications at higher specific velocities do show a relatively strong relationship between flow and capacity. The lack of a strong relationship will allow more flexibility in the implementation of an ion exchange bed for flight. Verification of subscale tests with flight-scale resin beds is recommended prior to implementation in the on-orbit UPA.

  14. A comparative study of ion exchange kinetics in zinc/lead-modified zeolite-clinoptilolite systems. (United States)

    Trgo, M; Perić, J; Medvidović, N Vukojević


    The kinetics of zinc and lead ions removal by modified zeolite-clinoptilolite has been investigated. The rate of the ion exchange process for lead ions is faster than for zinc ions, as well as the time needed to reach the equilibrium. The ion exchange capacity of zeolite of lead ions is doubly higher than that of zinc ions. Diffusion models according to the Vermeulen's approximation, the parabolic diffusion model and the homogeneous diffusion model have been tested with the experimental data of ion exchange for zinc and lead. For both systems examined, the best fit of the models proposed with the experimental data was shown by the Vermeulen's approximation and the homogeneous diffusion model with t-->t(infinity). The diffusion coefficients are calculated from kinetic models of lead ions they are of the order of 10(-6)cm(2)/min, constant for all examined initial concentrations and not dependent on time. The diffusion coefficients in the system of zinc ions is of the order of 10(-8)cm(2)/min, also independent of initial concentrations, but decreasing with time from the beginning of ion exchange to the equilibrium.

  15. Cation immobilization in pyrolyzed simulated spent ion exchange resins

    Energy Technology Data Exchange (ETDEWEB)

    Luca, Vittorio, E-mail: [Programa Nacional de Gestion de Residuos Radiactivos, Centro Atomico Constituyentes, Comision Nacional de Energia Atomica, Av. General, Paz 1499, 1650 San Martin, Provincia de Buenos Aires (Argentina); Bianchi, Hugo L. [Gerencia de Quimica, Centro Atomico Constituyentes, Comision Nacional de Energia Atomica, Av. General, Paz 1499, 1650 San Martin, Provincia de Buenos Aires (Argentina); ECyT, Universidad Nacional de General San Martin, Campus Miguelete, Ed. Tornavias, Martin de Irigoyen 3100, 1650 San Martin (Argentina); Conicet, Av. Rivadavia 1917, 1033 Buenos Aires (Argentina); Manzini, Alberto C. [Programa Nacional de Gestion de Residuos Radiactivos, Comision Nacional de Energia Atomica, Av. Del Libertador 8250, CP 1429, Ciudad Autonoma de Buenos Aires (Argentina)


    Significant quantities of spent ion exchange resins that are contaminated by an assortment of radioactive elements are produced by the nuclear industry each year. The baseline technology for the conditioning of these spent resins is encapsulation in ordinary Portland cement which has various shortcomings none the least of which is the relatively low loading of resin in the cement and the poor immobilization of highly mobile elements such as cesium. The present study was conducted with cationic resin samples (Lewatit S100) loaded with Cs{sup +}, Sr{sup 2+}, Co{sup 2+}, Ni{sup 2+} in roughly equimolar proportions at levels at or below 30% of the total cation exchange capacity. Low temperature thermal treatment of the resins was conducted in inert (Ar), or reducing (CH{sub 4}) gas atmospheres, or supercritical ethanol to convert the hydrated polymeric resin beads into carbonaceous materials that contained no water. This pyrolytic treatment resulted in at least a 50% volume reduction to give mechanically robust spherical materials. Scanning electron microscope investigations of cross-sections of the beads combined with energy dispersive analysis showed that initially all elements were uniformly distributed through the resin matrix but that at higher temperatures the distribution of Cs became inhomogeneous. Although Cs was found in the entire cross-section, a significant proportion of the Cs occurred within internal rings while a proportion migrated toward the outer surfaces to form a crustal deposit. Leaching experiments conducted in water at 25 Degree-Sign C showed that the divalent contaminant elements were very difficult to leach from the beads heated in inert atmospheres in the range 200-600 Degree-Sign C. Cumulative fractional loses of the order of 0.001 were observed for these divalent elements for temperatures below 500 Degree-Sign C. Regardless of the processing temperature, the cumulative fractional loss of Cs in water at 25 Degree-Sign C reached a plateau or

  16. Electrospun Zeolite/Cellulose Acetate Fibers for Ion Exchange of Pb2+

    Directory of Open Access Journals (Sweden)

    Daniel N. Tran


    Full Text Available The ion exchange capability of electrospun cellulose acetate (CA fibers containing zeolite A nanoparticles is reported. Solid and porous CA fibers were used to make a zeolite-embedded filter paper, which was then used to ion exchange Na+ with Cu2+ and Pb2+. The composite Linde Type A (LTA zeolite CA fibers exchanged 0.39 mmol/g more Pb2+ than LTA nanoparticles in the solid CA fibers. These fibers could provide a simple and effective method for heavy metal ion removal in water.

  17. Analyzing the effect of ion exchange on flexural strength of cermaco II and colorlogic veneer porcelains

    Directory of Open Access Journals (Sweden)

    N. Rashidan


    Full Text Available   The major foible of dental ceramics is their brittle nature. Therefore, the producers of these materials have focused on the “strength” issue. A method of increasing strength is ion exchange on porcelain surface which leads to formation of a compressive crust that opposing forces should overcome before developing a crack. In current study, ion exchange in two types of porcelain, Ceramco II which is used in PFM restorations and Colorloic veneer which is used for laminates, veneers, inlays and onlays, are evaluated. Additionally, laminate porcelains, etching effect on strength of porcelain and interaction of acid etching and ion exchange have been studied.

  18. Mixed ion exchange supports as useful ion exchangers for protein purification: purification of penicillin G acylase from Escherichia coli. (United States)

    Fuentes, Manuel; Batalla, Pilar; Grazu, Valeria; Pessela, Benevides C C; Mateo, Cesar; Montes, Tamara; Hermoso, Juan A; Guisan, Jose M; Fernandez-Lafuente, Roberto


    A support having similar amounts of carboxymethyl and amino groups has been prepared and evaluated as an ion exchanger. It has been found that this support was able to adsorb a high amount of protein from a crude extract of proteins (approximately 55%) at pH 5. Moreover, it was able to adsorb approximately 60% of the protein that did not become adsorbed on supports bearing just one kind of ionic groups. The use of divalent cations reinforced the adsorption of proteins on these supports. These results suggest that the adsorption of proteins on supports bearing almost neutral charge is not driven by the existence of opposite charges between the adsorbent and the biomacromolecule but just by the possibility of forming a high number of enzyme-support ionic bonds. This support has been used to purify the enzyme penicillin G acylase (PGA) from Escherichia coli. PGA was not significantly adsorbed at any pH value on either amino- or carboxyl-activated supports, while it can be fully adsorbed at pH 5 on this new carboxyl-amino matrix. Thus, we have been able to almost fully purify PGA from crude extracts with a very high yield by using these new supports.

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

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Viani, B.E.; Bruton, C.J. [Lawrence Livermore National Lab., CA (United States)


    Potential disposal of high-level nuclear waste at Yucca Mtn., Nevada requires the means to simulate ion-exchange behavior of clays and 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 and Sr on clinoptilolite, but a two-site Vanselow exchange model is necessary to describe K contents of natural clinoptilolites. 15 refs., 5 figs., 1 tab.

  1. High-speed ion-exclusion chromatography of dissolved carbon dioxide on a small weakly acidic cation-exchange resin column with ion-exchange enhancement columns of conductivity detection. (United States)

    Mori, Masanobu; Ikedo, Mikaru; Hu, Wenzhi; Helaleh, Murad I H; Xu, Qun; Itabashi, Hideyuki; Tanaka, Kazuhiko


    The high-speed ion-exclusion chromatographic determination of dissolved carbon dioxide, i.e., carbonic acid, hydrogencarbonate or carbonate, with conductivity detection was obtained using a small column packed with a weakly acidic cation-exchange resin in the H+-form (40 mm long x 4.6 mm i.d., 3 microm-particle and 0.1 meq./ml-capacity). Two different ion-exchange resin columns, which were a strongly acidic cation-exchange resin in the K+-form and a strongly basic anion-exchange resin in the OH- -form, were connected after the separation column. The sequence of columns could convert dissolved carbon dioxide to KOH having high conductivity response. The enhancement effect for dissolved carbon dioxide could retain even on the vast chromatographic runs, by using the enhancement columns with high ion-exchange capacity above 1.0 meq./ml. The retention time was in 60 s at flow-rate of 1.2 ml/min. The calibration graph of dissolved carbon dioxide estimated as H2CO3- was linear in the range of 0.005-10 mM. The detection limit at signal to noise of 3 was 0.15 microM as H2CO3-. This method was applicable to several rainwater and tap water samples.

  2. Application of ion beams in electronics

    Energy Technology Data Exchange (ETDEWEB)

    Rosinski, W.


    Application of ion beams to change surface layer properties of solids has been discussed. Examples and application possibilities in the range of semiconducting materials, magnetic and ceramic materials as well as in metalurgy have been described.

  3. Application of explosive welding to heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Arthur, G.


    The subject is discussed under the headings: advantages of explosive welding; principle of explosive welding; explosive welding of tubes; metallurgy of explosive welds (micrographs; microhardness); tubular heat exchangers; plugging; sleeving; retubing; construction of new heat exchangers; thermal sleeves.

  4. Quantitative Analysis of Water Confined in Ion-Exchanged Zeolites (United States)

    Wang, J.; Neuhoff, P. S.


    Zeolites, which host large quantities of water, are among the most important rock-forming and environmental minerals in the surface and near-surface regions of the Earth. The physical properties and geochemical behavior of water confined in zeolites differs substantially from that of bulk liquid water, and the energectics of confined water exerts a profound influence on the stability and behavior of zeolites in natural and engineered systems. Because the cations and water molecules are both located in the zeolitic channels, changes in cation content can influence the amount and site occupancies of water molecules in zeolites. In order to find out the relationship between the behavior of confined water and cation composition in zeolites, thermogravimetric and calorimetric experiments were conducted on the mordenite (one of the most common zeolites) samples of mixing Na+ and K+. These mordenite solid solutions were generated by binary ion exchange between pure synthetic Na-mordenite (CBV 10A, obtained from Zeolyst International) and chloride solutions containing Na+ and K+ of different equivalent concentration ratios. The results from dehydration and hydration of the mordenite solid solutions show that when the mole fraction of K+ in mordenite increases, the maximum water content of mordenite decreases and the enthalpy of hydration becomes less exothermic. More importantly, both maximum water content and enthalpy of hydration of mordenite are demonstrated to change linearly with mole fraction of K+. Two energetically distinct sets of water molecules have been observed in mordenite: W1 (relatively less energetic) and W2 (relatively high energetic). Thermodynamic analysis on the hydration of W1 and W2 reveals that these two sets of water molecules behave differently when cation composition of mordenite changes. The water content of W2 is independent of cation composition, whereas W1 loses water with when mole fraction of K+ increases; the enthalpy of hydration of W1

  5. Understanding ion and solvent transport in anion exchange membranes under humidified conditions (United States)

    Sarode, Himanshu

    Anion exchange membranes (AEM) have been studied for more than a decade for potential applications in low temperature fuel cells and other electrochemical devices. They offer the advantage of faster reaction kinetics under alkaline conditions and ability to perform without costly platinum catalyst. Inherently slow diffusion of hydroxide ions compared to protons is a primary reason for synthesizing and studying the ion transport properties in AEMs. The aim of this thesis is to understand ion transport in novel AEMs using Pulse Gradient stimulated Spin Echo Nuclear Magnetic Resonance technique (PGSE NMR), water uptake, ionic conductivity, Small Angle X-ray Scattering (SAXS) etc. All experiments were performed under humidified conditions (80--95% relative humidity) and fuel cell operating temperatures of 30--90°C. In this work, the NMR tube design was modified for humidifying the entire NMR tube evenly from our previous design. We have developed a new protocol for replacing caustic hydroxide with harmless fluoride or bicarbonate ions for 19F and 13 C NMR diffusion experiments. After performing these NMR experiments, we have obtained in-depth understanding of the morphology linked ion transport in AEMs. We have obtained the highest fluoride self-diffusion coefficient of > 1 x 10-5 cm2/sec ( 55°C) for ETFE-g-PVBTMA membrane which is a result of low tortuosity of 1 obtained for the membrane. This faster fluoride transport combined with low tortuosity of the membrane resulted in > 100mS/cm hydroxide conductivity for the membrane. Polycyclooctene (PCOE) based triblock copolymers are also studied for in-depth understanding of molecular weight, IEC, mechanical and transport properties. Effect of melting temperature of PCOE has favorable effect on increasing ion conductivity and lowering activation energy. Mechanical properties of these types of membranes were studied showing detrimental effect of water plasticization which results in unsuitable mechanical properties

  6. Bioactive and Antibacterial Glass Powders Doped with Copper by Ion-Exchange in Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Marta Miola


    Full Text Available In this work, two bioactive glass powders (SBA2 and SBA3 were doped with Cu by means of the ion-exchange technique in aqueous solution. SBA2 glass was subjected to the ion-exchange process by using different Cu salts (copper(II nitrate, chloride, acetate, and sulphate and concentrations. Structural (X-ray diffraction-XRD, morphological (Scanning Electron Microscopy-SEM, and compositional (Energy Dispersion Spectrometry-EDS analyses evidenced the formation of crystalline phases for glasses ion-exchanged in copper(II nitrate and chloride solutions; while the ion-exchange in copper(II acetate solutions lead to the incorporation of higher Cu amount than the ion-exchange in copper(II sulphate solutions. For this reason, the antibacterial test (inhibition halo towards S. aureus was performed on SBA2 powders ion-exchanged in copper(II acetate solutions and evidenced a limited antibacterial effect. A second glass composition (SBA3 was developed to allow a greater incorporation of Cu in the glass surface; SBA3 powders were ion-exchanged in copper(II acetate solutions (0.01 M and 0.05 M. Cu-doped SBA3 powders showed an amorphous structure; morphological analysis evidenced a rougher surface for Cu-doped powders in comparison to the undoped glass. EDS and X-ray photoelectron spectroscopy (XPS confirmed the Cu introduction as Cu(II ions. Bioactivity test in simulated body fluid (SBF showed that Cu introduction did not alter the bioactive behaviour of the glass. Finally, inhibition halo test towards S. aureus evidenced a good antimicrobial effect for glass powders ion-exchanged in copper(II acetate solutions 0.05 M.

  7. Negligible birefringence in dual-mode ion-exchanged glass waveguide gratings. (United States)

    Yliniemi, Sanna; Albert, Jacques; Laronche, Albane; Castro, Jose M; Geraghty, David; Honkanen, Seppo


    Polarization dependence of UV-written Bragg gratings in buried ion-exchanged glass waveguides is investigated. A polarization-dependent shift in Bragg wavelength of less than 0.02 nm is measured, both for the even and the odd modes of a laterally dual-mode waveguide. The measured wavelength shift corresponds to a waveguide birefringence of the order of 10(-5), which is negligible for most applications in optical communications. It is observed that the UV-induced birefringence is small, within the limits of the measurement accuracy. The thermal stability of the fabricated gratings is also very good. The results are of particular importance for devices considered here since they require a polarization-independent mode-converting waveguide Bragg grating. Polarization-independent performance of these gratings enables the fabrication of a new class of integrated optical devices for telecommunication applications.

  8. Experimental Findings On Minor Actinide And Lanthanide Separations Using Ion Exchange

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, D. T.; Shehee, T. C.; Clearfield, A.


    This project seeks to determine if inorganic or hybrid inorganic ion-exchange materials can be exploited to provide effective americium and curium separations. Specifically, we seek to understand the fundamental structural and chemical factors responsible for the selectivity of the tested ion-exchange materials for actinide and lanthanide ions. During FY13, experimental work focused in the following areas: (1) investigating methods to oxidize americium in dilute nitric acid with subsequent ion-exchange performance measurements of ion exchangers with the oxidized americium and (2) synthesis, characterization and testing of ion-exchange materials. Ion-exchange materials tested included alkali titanates, alkali titanosilicates, carbon nanotubes and group(IV) metal phosphonates. Americium oxidation testing sought to determine the influence that other redox active components may have on the oxidation of Am(III). Experimental findings indicated that Pu(IV) is oxidized to Pu(VI) by peroxydisulfate, but there are no indications that the presence of plutonium affects the rate or extent of americium oxidation at the concentrations of peroxydisulfate being used. Tests also explored the influence of nitrite on the oxidation of Am(III). Given the formation of Am(V) and Am(VI) in the presence of nitrite, it appears that nitrite is not a strong deterrent to the oxidation of Am(III), but may be limiting Am(VI) by quickly reducing Am(VI) to Am(V). Interestingly, additional absorbance peaks were observed in the UV-Vis spectra at 524 and 544 nm in both nitric acid and perchloric acid solutions when the peroxydisulfate was added as a solution. These peaks have not been previously observed and do not correspond to the expected peak locations for oxidized americium in solution. Additional studies are in progress to identify these unknown peaks. Three titanosilicate ion exchangers were synthesized using a microwave-accelerated reaction system (MARS) and determined to have high affinities

  9. Tuning a High Transmission Ion Guide to Prevent Gas-Phase Proton Exchange During H/D Exchange MS Analysis. (United States)

    Guttman, Miklos; Wales, Thomas E; Whittington, Dale; Engen, John R; Brown, Jeffery M; Lee, Kelly K


    Hydrogen/deuterium exchange (HDX) mass spectrometry (MS) for protein structural analysis has been adopted for many purposes, including biopharmaceutical development. One of the benefits of examining amide proton exchange by mass spectrometry is that it can readily resolve different exchange regimes, as evidenced by either binomial or bimodal isotope patterns. By careful analysis of the isotope pattern during exchange, more insight can be obtained on protein behavior in solution. However, one must be sure that any observed bimodal isotope patterns are not artifacts of analysis and are reflective of the true behavior in solution. Sample carryover and certain stationary phases are known as potential sources of bimodal artifacts. Here, we describe an additional undocumented source of deuterium loss resulting in artificial bimodal patterns for certain highly charged peptides. We demonstrate that this phenomenon is predominantly due to gas-phase proton exchange between peptides and bulk solvent within the initial stages of high-transmission conjoined ion guides. Minor adjustments of the ion guide settings, as reported here, eliminate the phenomenon without sacrificing signal intensity. Such gas-phase deuterium loss should be appreciated for all HDX-MS studies using such ion optics, even for routine studies not focused on interpreting bimodal spectra. Graphical Abstract ᅟ.

  10. Negative Ions for Emerging Interdisciplinary Applications (United States)

    Guharay, Samar K.


    In many applications related to ion beam-materials interactions negative ions are particularly desirable due to its merit to yield a very low surface charge-up voltage, ˜ a few volts, for both electrically isolated surfaces and insulators. Some important applications pertaining to ion beam-material interactions include surface analysis by secondary ion mass spectrometry (SIMS), voltage-contrast microscopy for semiconductor device inspection, materials processing, and ion beam lithography. These applications primarily require vacuum environments. On the other hand, a distinct area of activities constitutes formation of ions and ion transport in ambient environmental conditions, i.e., at atmospheric pressures. In this context, ion mobility spectrometry (IMS) is an important analytical device that uses negative ions and operates at ambient conditions. IMS is widely used in both physical and biological sciences including monitoring environmental conditions, security screening and disease detection. This article highlights several critical issues related to the ionization sources and ion transport in IMS. Additionally, the critical issues related to ion sources, transport and focusing are discussed in the context of SIMS with sub-micrometer spatial resolution.

  11. Free volume and gas permeation in ion-exchanged forms of the Nafion® membrane (United States)

    Mohamed, Hamdy F. M.; Kobayashi, Y.; Kuroda, C. S.; Ohira, A.


    Variations of free volume and gas permeability of the Nafion® membrane upon ion-exchange of H+ with Cs+ or Pt2+ was studied as a function of temperature. Free volume was quantified using the positron annihilation lifetime technique. Our results showed that the free volume (VFV,Ps) of the dried membrane is enlarged by thermal expansion. It was found that the ion-exchange significantly expands the free volume and at the same time decreases the permeabilities of O2 and H2. Good linear correlations between the logarithm of permeabilities of O2 and H2 at different temperatures and 1/VFV,Ps for the ion-exchanged forms of Nafion® in the dried state suggest an important role played by the free volume in gas permeation. Considerable downward deviation of the correlations for the ion-exchanged ionomers from the H+-form suggested the importance of polymer stiffening in gas permeation.

  12. Non-centrosymmetric behavior of a clay film ion-exchanged with chiral metal complexes. (United States)

    Suzuki, Yasutaka; Matsunaga, Ryoya; Sato, Hisako; Kogure, Toshihiro; Yamagishi, Akihiko; Kawamata, Jun


    SHG measurements on a highly transparent clay film ion-exchanged with chiral metal complexes revealed that the mono-molecular layer of the chiral complexes in an interlayer space acquired a non-centrosymmetric character.

  13. Adsorption Mechanisms of Heavy Metal Ions from Drinking Water by Weakly Basic Anion Exchange Resins

    Institute of Scientific and Technical Information of China (English)

    赵璇; 何仕均; 杨磊


    Heavy metal micro-contaminants can be removed from water sources technologies. Weakly basic anion exchange resins offer the best ability to remove trace amounts of heavy metals with high selectivity. This paper discusses how weakly basic resins adsorb heavy metals using two different approaches. The removal of mercury, cadmium, and lead ions is based on the fundamental theory of coordination chemistry. The mechanism is not ion exchange but extractive adsorption of heavy metal salts. However, the marked preferential adsorption of chromate by weakly basic anion exchange can be explained using the traditional theory of ion exchange. A lab-scale study produced positive results for the removal of trace amounts of heavy metal ions from drinking water.


    Energy Technology Data Exchange (ETDEWEB)

    Smith, F; Luther Hamm, L; Sebastian Aleman, S; Johnston Michael, J


    The performance of spherical Resorcinol-Formaldehyde ion-exchange resin for the removal of cesium from alkaline radioactive waste solutions has been investigated through computer modeling. Cesium adsorption isotherms were obtained by fitting experimental data using a thermodynamic framework. Results show that ion-exchange is an efficient method for cesium removal from highly alkaline radioactive waste solutions. On average, two 1300 liter columns operating in series are able to treat 690,000 liters of waste with an initial cesium concentration of 0.09 mM in 11 days achieving a decontamination factor of over 50,000. The study also tested the sensitivity of ion-exchange column performance to variations in flow rate, temperature and column dimensions. Modeling results can be used to optimize design of the ion exchange system.

  15. Media selection in ion-exchange chromatography in a single microplate. (United States)

    Cabanne, Charlotte; Santarelli, Xavier


    High-throughput process development is more and more used in chromatography. Limitations are the tools provided by the manufacturers. Here, we describe a method to select chromatographic media for ion-exchange chromatography using a 96-well filter microplate.


    Energy Technology Data Exchange (ETDEWEB)

    King, W


    This report summarizes the results of literature reviews conducted to support the selection of a cesium removal technology for application in a small column ion exchange (SCIX) unit supported within a high level waste tank. SCIX is being considered as a technology for the treatment of radioactive salt solutions in order to accelerate closure of waste tanks at the Savannah River Site (SRS) as part of the Modular Salt Processing (MSP) technology development program. Two ion exchange materials, spherical Resorcinol-Formaldehyde (RF) and engineered Crystalline Silicotitanate (CST), are being considered for use within the SCIX unit. Both ion exchange materials have been studied extensively and are known to have high affinities for cesium ions in caustic tank waste supernates. RF is an elutable organic resin and CST is a non-elutable inorganic material. Waste treatment processes developed for the two technologies will differ with regard to solutions processed, secondary waste streams generated, optimum column size, and waste throughput. Pertinent references, anticipated processing sequences for utilization in waste treatment, gaps in the available data, and technical comparisons will be provided for the two ion exchange materials to assist in technology selection for SCIX. The engineered, granular form of CST (UOP IE-911) was the baseline ion exchange material used for the initial development and design of the SRS SCIX process (McCabe, 2005). To date, in-tank SCIX has not been implemented for treatment of radioactive waste solutions at SRS. Since initial development and consideration of SCIX for SRS waste treatment an alternative technology has been developed as part of the River Protection Project Waste Treatment Plant (RPP-WTP) Research and Technology program (Thorson, 2006). Spherical RF resin is the baseline media for cesium removal in the RPP-WTP, which was designed for the treatment of radioactive waste supernates and is currently under construction in Hanford, WA

  17. Application of ion-exchange cartridge clean-up in food analysis III. Determination of benzylpenicillin, phenoxymethyl-penicillin, oxacillin, cloxacillin, nafcillin and dicloxacillin in bovine liver and kidney by liquid chromatography with ultraviolet detection. (United States)

    Ito, Y; Ikai, Y; Oka, H; Matsumoto, H; Kagami, T; Takeba, K


    A multiresidue analytical method was developed for the simultaneous determination of benzylpenicillin (PCG), phenoxymethylpenicillin (PCV), oxacillin (MPIPC), cloxacillin (MCIPC), nafcillin (NFPC) and dicloxacillin (MDIPC) in bovine liver and kidney. The method involves the use of an ion-exchange cartridge for sample clean-up followed by ion-pair high-performance liquid chromatography with ultraviolet detection. The recoveries of PCG, PCV, MPIPC, MCIPC, NFPC and MDIPC from bovine liver spiked at levels of 0.5 mg/kg and 0.1 mg/kg were in the range of 73-91% and 83-96% with coefficients of variation of 1.4-4.2% and 3.4-8.7%, respectively. For bovine kidney spiked at levels of 0.5 mg/kg and 0.1 mg/kg, the recoveries of these compounds were 79-92% and 82-92% with RSDs of 1.8-5.9% and 2.7-7.8%, respectively. The detection limits for the six penicillins were 0.02-0.05 mg/kg in bovine liver and kidney.

  18. 75 FR 51295 - In the Matter of the Application of BATS Y-Exchange, Inc. for Registration as a National... (United States)


    ... behalf of the Exchange, including operation of the Exchange's arbitration program. BATS Y Exchange... International Securities Exchange LLC's application for registration as a national securities exchange). \\94\\ Id...

  19. Biomineralization of hydroxyapatite in silver ion-exchanged nanocrystalline ZSM-5 zeolite using simulated body fluid. (United States)

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


    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.

  20. Ion Exchange Modeling Of Cesium Removal From Hanford Waste Using Spherical Resorcinol-Formaldehyde Resin

    Energy Technology Data Exchange (ETDEWEB)

    Aleman, S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hamm, L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Smith, F. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)


    This report discusses the expected performance of spherical Resorcinol-Formaldehyde (RF) ion exchange resin for the removal of cesium from alkaline Hanford radioactive waste. Predictions of full scale column performance in a carousel mode are made for the Hot Commissioning, Envelope B, and Subsequent Operations waste compositions under nominal operating conditions and for perturbations from the nominal. Only the loading phase of the process cycle is addressed in this report. Pertinent bench-scale column tests, kinetic experiments, and batch equilibrium experiments are used to estimate model parameters and to benchmark the ion-exchange model. The methodology and application presented in this report reflect the expected behavior of spherical RF resin manufactured at the intermediate-scale (i.e., approximately 100 gallon batch size; batch 5E-370/641). It is generally believed that scale-up to production-scale in resin manufacturing will result in similarly behaving resin batches whose chemical selectivity is unaffected while total capacity per gram of resin may vary some. As such, the full-scale facility predictions provided within this report should provide reasonable estimates of production-scale column performance.

  1. Hydrogen adsorption over Zeolite-like MOF materials modified by ion exchange

    Energy Technology Data Exchange (ETDEWEB)

    Calleja, G.; Botas, J.A.; Orcajo, M.G. [Department of Chemical and Energy Technology, ESCET, Universidad Rey Juan Carlos, C/Tulipan s/n, 28933 Mostoles, Madrid (Spain); Sanchez-Sanchez, M. [Instituto de Catalisis y Petroleoquimica, CSIC, C/Marie Curie 2, 28049 Madrid (Spain)


    Novel porous Zeolite-like metal-organic framework (ZMOF) materials with Rho and Sod topologies are promising adsorbents for hydrogen storage due to their high surface area and, more importantly, to their capacity of being ion-exchanged, potentially changing their affinity for hydrogen. In this work, we have successfully synthesized both Rho and SodZMOF materials, optimizing experimental conditions for scaling-up the procedure already published to produce grams of material. The resultant materials were alkaline-cation-exchanged, widely characterized and finally tested as hydrogen adsorbents. RhoZMOF is converted into an amorphous phase during some of the ion-exchange processes, whereas SodZMOF, whose ion-exchange capacity has not been investigated so far, always maintains its topology for any tested exchange cation and conditions. Additionally, thermogravimetric analyses and thermal treatments followed by in-situ powder X-ray diffraction analysis have evidenced a significantly higher thermal stability of both as-prepared and ion-exchanged SodZMOF materials in comparison to their Rho-structured homologues. Moreover, the thermal stability of the cation-exchanged ZMOF samples improves when methanol is the ion-exchange solvent rather than the reported ethanol-water mixture. Nitrogen and hydrogen adsorption isotherms at 77 K suggested that alkali-exchanged materials have lower affinity for hydrogen than the as-prepared samples compensated by imidazolium ion; however, due to the smaller size of Na{sup +} or Li{sup +} cations, their lower affinity is easily compensated by the inherent increase in surface area and pore volume as exchange degree increases. (author)

  2. Crystalline Silicotitanate: a New Type of Ion Exchanger for Cs Removal from Liquid Waste

    Institute of Scientific and Technical Information of China (English)


    The research and developments of a new type of inorganic ion exchanger, crystalline silicotitanate (CST) are reviewed.This material is stable against radiation, and the CST has high selectivity for Cs over Na, K and Rb. It performs well in acidic, neutral, and basic solutions. The results of ion exchange tests show that CST is an excellent candidate for Cs removal from high-level liquid waste.

  3. Analyzing the effect of ion exchange on flexural strength of cermaco II and colorlogic veneer porcelains


    N. Rashidan; HA. Mahgoli


      The major foible of dental ceramics is their brittle nature. Therefore, the producers of these materials have focused on the “strength” issue. A method of increasing strength is ion exchange on porcelain surface which leads to formation of a compressive crust that opposing forces should overcome before developing a crack. In current study, ion exchange in two types of porcelain, Ceramco II which is used in PFM restorations and Colorloic veneer which is used for laminates, veneers, inlays an...

  4. Experimental Ion Exchange Column With SuperLig 639 And Simulant Formulation

    Energy Technology Data Exchange (ETDEWEB)

    Morse, Megan; Nash, C.


    SuperLig®639 ion exchange resin was tested as a retrieval mechanism for pertechnetate, through decontamination of a perrhenate spiked 5M Simple Average Na{sup +} Mass Based Simulant. Testing included batch contacts and a three-column ion exchange campaign. A decontamination of perrhenate exceeding 99% from the liquid feed was demonstrated. Analysis of the first formulation of a SBS/WESP simulant found unexpectedly low concentrations of soluble aluminum. Follow-on work will complete the formulation.

  5. Lawps ion exchange column gravity drain of spherical resorcinol formaldehyde resin

    Energy Technology Data Exchange (ETDEWEB)

    Duignan, M. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Herman, D. T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Restivo, M. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Burket, P. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)


    Experiments at several different scales were performed to understand the removal of spherical resorcinol formaldehyde (sRF) ion exchange resin using a gravity drain system with a valve located above the resin screen in the ion exchange column (IXC). This is being considered as part of the design for the Low Activity Waste Pretreatment System (LAWPS) to be constructed at the DOE Hanford Site.

  6. "One-Pot" Ion-Exchange and Mesopore Formation During Desilication

    DEFF Research Database (Denmark)

    Holm, Martin Spangsberg; Hansen, Martin Kalmar; Christensen, Claus Hviid


    A desilication protocol using tetramethylammonium hydroxide was applied to zeolite beta. The new route presented here integrates the desilication and ion-exchange post-treatment steps allowing for a subsequent ion-exchange step to be avoided. It is shown that the acidic and highly mesoporous zeol...... zeolite is obtained directly upon calcination. Thus, careful choice of base and post-treatment conditions lead to the fabrication of a hierarchical meso- and microporous structure with completely retained crystallinity. (...

  7. Assessment of commercially available ion exchange materials for cesium removal from highly alkaline wastes

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, K.P.; Kim, A.Y.; Kurath, D.E.


    Approximately 61 million gallons of nuclear waste generated in plutonium production, radionuclide removal campaigns, and research and development activities is stored on the Department of Energy`s Hanford Site, near Richland, Washington. Although the pretreatment process and disposal requirements are still being defined, most pretreatment scenarios include removal of cesium from the aqueous streams. In many cases, after cesium is removed, the dissolved salt cakes and supernates can be disposed of as LLW. Ion exchange has been a leading candidate for this separation. Ion exchange systems have the advantage of simplicity of equipment and operation and provide many theoretical stages in a small space. The organic ion exchange material Duolite{trademark} CS-100 has been selected as the baseline exchanger for conceptual design of the Initial Pretreatment Module (IPM). Use of CS-100 was chosen because it is considered a conservative, technologically feasible approach. During FY 96, final resin down-selection will occur for IPM Title 1 design. Alternate ion exchange materials for cesium exchange will be considered at that time. The purpose of this report is to conduct a search for commercially available ion exchange materials which could potentially replace CS-100. This report will provide where possible a comparison of these resin in their ability to remove low concentrations of cesium from highly alkaline solutions. Materials which show promise can be studied further, while less encouraging resins can be eliminated from consideration.

  8. Photosensitivity of ion-exchanged Er-doped phosphate glass using 248nm excimer laser radiation. (United States)

    Pissadakis, Stavros; Ikiades, Aris; Hua, Ping; Sheridan, Anna; Wilkinson, James


    The photosensitivity to 248nm excimer laser radiation of Er-doped Schott IOG-1 phosphate glass is presented. The photosensitive mechanism is investigated by employing a grating recording process. Index changes of up to ~2.0x10(-3) were measured in silver ion-exchanged samples using diffraction efficiency measurements; whereas changes of only ~10(-5) were measured for non-ion-exchanged samples. Absorption measurements allowed the identification of specific color center bands, which were attributed to the glass matrix and to the silver ions. Investigation of the exposed ion-exchanged glass using scanning electron microscopy and energy dispersive x-ray microanalysis revealed that in addition to the color centers formed, silver ion migration and ionization contribute significantly to the UV-induced index changes.

  9. Effect of grinding and fluoride-gel exposure on strength of ion-exchanged porcelain. (United States)

    Anusavice, K J; Hojjatie, B; Chang, T C


    Strengthening of dental porcelain through a diffusion heat treatment at 450 degrees C of a potassium-enriched, ion-exchange surface coating has been demonstrated in several recent studies. However, little attention has been focused on the potential strength reduction of these materials when the treated surfaces are ground or etched under clinically simulated conditions. The objective of this study was to test the hypothesis that partial removal of the surface layers of ion-exchanged porcelains by grinding or exposure to acidulated fluoride gel will significantly reduce their flexure strength. Nine groups of body porcelain disks were ion-exchanged at 450 degrees C for 30 min. One of these groups was subjected to ion exchange and no further surface treatment. Eight specimen groups were subjected to the following procedures after ion exchange: grinding to depths of 50 microns, 100 microns, 150 microns, 200 microns, and 250 microns, and exposure to acidulated fluoride for 30 min, 60 min, and 300 min. A tenth group (FC) was fired at 960 degrees C and fast-cooled in air, but the disks were not subjected to the ion-exchange treatment. Surface stress was calculated from measured values of cracks induced in the treated surfaces. Fluoride exposure for up to 60 min resulted in a significant decrease in surface compression (P 0.05).

  10. Reducing ion exchange resins rad-wastes, experience at EDF PWRs

    Energy Technology Data Exchange (ETDEWEB)

    Fene, G. [Rohm and Haas Co. (France); Hoffman, B. [Rohm and Haas Co. (United States)


    Life time of an ion exchange resin in a Nuclear Power Station (EDF PWR). At the end of its life, an ion exchange resin which has been used to treat radioactive streams becomes a radwaste itself. Its level of radioactivity depends on the point of use and consequently on the circuit where it was used. Roughly speaking, in a Nuclear Power Station PWR we can consider two types of radwaste families: High radioactive family Ion exchange resins which come from primary circuit: reactor control and storage pools. Ion exchange resins which have worked in a decontamination circuit: waste water treatment. Low radioactive family Ion exchange resins which come from secondary circuit: Steam Generator Blowdown By understanding and carefully applying some critical properties of ion exchange resins, such as total capacity, selectivity, and physical structure, it is possible for nuclear power stations to minimize radwaste volumes, while at the same time improving plant performance. This type of improvement can be facilitated by close cooperation and communication between the resin producer and the nuclear power user. (authors)


    Energy Technology Data Exchange (ETDEWEB)

    Herman, D.


    SRNL was requested to quantify the amount of 'fines passage' through the 0.5 micron membranes currently used for the rotary microfilter (RMF). Testing was also completed to determine if there is any additional benefit to utilizing a 0.1 micron filter to reduce the amount of fines that could pass through the filter. Quantifying of the amount of fines that passed through the two sets of membranes that were tested was accomplished by analyzing the filtrate by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) for titanium. Even with preparations to isolate the titanium, all samples returned results of less than the instrument's detection limit of 0.184 mg/L. Test results show that the 0.5 micron filters produced a significantly higher flux while showing a negligible difference in filtrate clarity measured by turbidity. The first targeted deployment of the RMF is with the Small Column Ion Exchange (SCIX) at the Savannah River Site (SRS). SCIX uses crystalline silicotitanate (CST) to sorb cesium to decontaminate a clarified salt solution. The passage of fine particles through the filter membranes in sufficient quantities has the potential to impact the downstream facilities. To determine the amount of fines passage, a contract was established with SpinTek Filtration to operate a 3-disk pilot scale unit with prototypic filter disk and various feeds and two different filter disk membranes. SpinTek evaluated a set of the baseline 0.5 micron filter disks as well as a set of 0.1 micron filter disks to determine the amount of fine particles that would pass the membrane and to determine the flux each set produced. The membrane on both disk sets is manufactured by the Pall Corporation (PMM 050). Each set of disks was run with three feed combinations: prototypically ground CST, CST plus monosodium titanate (MST), and CST, MST, plus Sludge Batch 6 (SB6) simulant. Throughout the testing, samples of the filtrate were collected, measured for turbidity


    Energy Technology Data Exchange (ETDEWEB)

    Nash, C.; Duignan, M.


    This report presents characterization data for two spherical resorcinol-formaldehyde (sRF) resin beds that had processed cesium in non-radioactive and radioactive cycles. All column cycle operations for the resin beds including loading, displacements, elution, regeneration, breakthroughs, and solution analyses are reported in Nash and Duignan, 2009a. That report covered four ion exchange (IX) campaigns using the two {approx}11 mL beds in columns in a lead-lag arrangement. The first two campaigns used Savannah River Site (SRS) Tank 2F nonradioactive simulant while the latter two were fed with actual dissolved salt in the Savannah River National Laboratory (SRNL) Shielded Cells. Both radioactive cycles ran to cesium breakthrough of the lead column. The resin beds saw in excess of 400 bed volumes of feed in each cycle. Resin disposal plans in tank farm processing depend on characterizations of resin used with actual tank feed. Following a final 30 bed volume (BV) elution with nitric acid, the resin beds were found to contain detectable chromium, barium, boron, aluminum, iron, sodium, sulfur, plutonium, cesium, and mercury. Resin affinity for plutonium is important in criticality safety considerations. Cesium-137 was found to be less than 10E+7 dpm/g of resin, similar to past work with sRF resin. Sulfur levels are reasonably consistent with other work and are expected to represent sulfur chemistry used in the resin manufacture. There were low but detectable levels of technetium, americium, and curium. Toxicity Characteristic Leaching Procedure (TCLP) work on the used (eluted) resin samples showed significant contents of mercury, barium, and chromium. One resin sample exceeded the TCLP level for mercury while the other metals were below TCLP levels. TCLP organics measurements indicated measurable benzene in one case, though the source was unknown. Results of this work were compared with other work on similar sRF resin characterizations in this report. This is the first

  13. Recent Excitation, Charge Exchange, and Lifetime Results in Highly Charged Ions Relevant to Stellar, Interstellar, Solar and Comet Phenomena (United States)

    Chutjian, A.; Hossain, S.; Mawhorter, R. J.; Smith, S. J.


    Recent JPL absolute excitation and charge exchange cross sections, and measurements of lifetimes of metastable levels in highly-charged ions (HCIs) are reported. These data provide benchmark comparisons to results of theoretical calculations. Theoretical approaches can then be used to calculate the vast array of data which cannot be measured due to experimental constraints. Applications to the X-ray emission from comets are given.

  14. Synthesis, Characterization and Ion Exchange Properties of a New Composite of Inorganic Ion Exchanger: Polyacrylonitrile Cerium(IV) Molybdophosphate%Synthesis, Characterization and Ion Exchange Properties of a New Composite of Inorganic Ion Exchanger: Polyacrylonitrile Cerium(IV) Molybdophosphate

    Institute of Scientific and Technical Information of China (English)

    Ahmadi, Seyed Javad; Yavari, Ramin; Ashtari, Parviz'; Gholipour, Vanik; Kamel, Leila; Rakhshandehru, Farokh


    In this work, the synthesis of the composite of cerium(IV) molybdophosphate (CMP) and polyacrylonitrile (PAN) was reported (CMP-PAN). The material has been characterized by elemental and spectral (FT-IR), X-ray and thermal (TGA) analysis. Also the size analysis of the composite was done by scanning electron microscopy (SEM). Its chemical stability in acidic, basic and saline solutions and radiation stability up to 100 kGy total expose dose were assessed. Whereas the synthesized composite has ion exchange properties, its ion exchange capacity and behavior toward several metal ions were also investigated. Further, the distribution coefficients of the metal ions were calculated. Finally, the ability of the synthesized CMP-PAN composite for the decontamination of low level liquid waste (LLLW) was investigated.

  15. Competitive migration behaviors of multiple ions and their impacts on ion-exchange resin packed microbial desalination cell. (United States)

    Zuo, Kuichang; Yuan, Lulu; Wei, Jincheng; Liang, Peng; Huang, Xia


    Mixed ion-exchange resins packed microbial desalination cell (R-MDC) could stabilize the internal resistance, however, the impacts of multiple ions on R-MDC performance was unclear. This study investigated the desalination performance, multiple ions migration behaviors and their impacts on R-MDCs fed with salt solution containing multiple anions and cations. Results showed that R-MDC removed multiple anions better than multiple cations with desalination efficiency of 99% (effluent conductivity NO3(-)>Cl(-) for anions and Ca(2+)≈Mg(2+)>NH4(+)>Na(+) for cations, jointly affected by both their molar conductivity and exchange selectivity on resins. After long-term operation, the existence of higher concentration Ca(2+) and Mg(2+) caused the electric conductivity of mixed resins decrease and scaling on the surface of cation-exchange membrane adjoined with cathode chamber, suggesting that R-MDC would be more suitable for desalination of water with lower hardness.

  16. Ion sources for cyclotron applications

    Energy Technology Data Exchange (ETDEWEB)

    Leung, K.N.; Bachman, D.A.; McDonald, D.S.; Young, A.T.


    The use of a multicusp plasma generator as an ion source has many advantages. The development of both positive and negative ion beams based on the multicusp source geometry is presented. It is shown that these sources can be operated at steady state or cw mode. As a result they are very suitable for cyclotron operations.

  17. Electrochemical ion exchanger in the water circuit to measure cation conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Bengtsson, Bernt; Ingemarsson, Rolf; Settervik, Gustav [Ringhals AB, Vaeroebacka (Sweden); Velin, Anna [Vattenfall Research and Development AB, Stockholm (Sweden)


    At Ringhals Nuclear Power Plant (NPP), more than four years of successful operation with a full-scale electrode ionization (EDI) unit for the recycling of steam generator blowdown gave the inspiration to modify and scale down this EDI process. As part of this project, the possibility of replacing the cation exchanger columns used for cation conductivity analysis with some small and integrated electrochemical ion exchange cells was explored. Monitoring the cation conductivity requires the use of a small cation resin column upstream of the conductivity probe and is one of the most important analyses at power plants. However, when operating with high alkaline treatment in the steam circuit, there is the disadvantage of rapid exhaustion of the resins, necessitating frequent replacement or regeneration. This causes interruptions in the monitoring and gives rise to a high workload for the maintenance staff. This paper reports on the optimization and testing of two different two-compartment electrochemical cells for possible replacement of the cation resin columns for analyzing cation conductivity in the secondary steam circuit at Ringhals NPP. Field tests during start-up conditions and more than four months of steady operation together with real and simulated tests for impurity influences indicate that an electrical ion exchange (ELIX) process could be successfully used to replace the resin columns in Ringhals while operating with high-pH all-volatile treatment (AVT) using hydrazine and ammonia. Installation of an ELIX system downstream of a particle filter and upstream of a small cation resin column will introduce additional safety and further reduce the maintenance and possible interruptions. Performance of the ELIX process together with other chemical additives (morpholine, ethanolamine, 3-methoxypropylamine, dimethylamine) and dispersants may be further evaluated to qualify the ELIX process as well as steam generator blowdown electrodeionization for wider use in

  18. Negative Halogen Ions for Fusion Applications

    Energy Technology Data Exchange (ETDEWEB)

    Grisham, L.R.; Kwan, J.W.; Hahto, S.K.; Hahto, S.T.; Leung, K.N.; Westenskow, G.


    Over the past quarter century, advances in hydrogen negative ion sources have extended the usable range of hydrogen isotope neutral beams to energies suitable for large magnetically confined fusion devices. Recently, drawing upon this experience, negative halogen ions have been proposed as an alternative to positive ions for heavy ion fusion drivers in inertial confinement fusion, because electron accumulation would be prevented in negative ion beams, and if desired, the beams could be photo-detached to neutrals. This paper reports the results of an experiment comparing the current density and beam emittance of Cl+ and Cl- extracted from substantially ion-ion plasmas with that of Ar+ extracted from an ordinary electron-ion plasma, all using the same source, extractor, and emittance scanner. At similar discharge conditions, the Cl- current was typically 85 – 90% of the positive chlorine current, with an e-/ Cl- ratio as low as seven without grid magnets. The Cl- was as much as 76% of the Ar+ current from a discharge with the same RF drive. The minimum normalized beam emittance and inferred ion temperatures of Cl+, Cl-, and Ar+ were all similar, so the current density and optical quality of Cl- appear as suitable for heavy ion fusion driver applications as a positive noble gas ion of similar mass. Since F, I, and Br should all behave similarly in an ion source, they should also be suitable as driver beams.

  19. 22 CFR Appendix B to Part 62 - Exchange Visitor Program Services, Exchange-Visitor Program Application (United States)


    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Exchange Visitor Program Services, Exchange-Visitor Program Application B Appendix B to Part 62 Foreign Relations DEPARTMENT OF STATE PUBLIC DIPLOMACY... information on program. IF TRAINING PROGRAM, identify appropriate fields: 01—Arts & Culture;...

  20. Synthesis and characterization of functional peek for ion-exchange membranes

    CSIR Research Space (South Africa)

    Luo, H


    Full Text Available The sulfonated and sulfinated polyetheretherketone (SsPEEK) was prepared via a novel method. SsPEEK has two types of functional groups, the functional groups for ion-exchange and the functional groups for further strengthening of the ion...

  1. Effect of Rare Earth Elements on Exchange Performances of Cesium Ion-Sieve

    Institute of Scientific and Technical Information of China (English)

    张惠源; 王榕树; 林灿生; 张先业


    The exchange performances and the distribution coefficient of Cesium Ion-Sieve (Cs-IS) for cesium and for some rare earth elements were compared. In particular, the effects of neodymium on the cesium ion exchange and the Cs+ selectivity variation on Cs-IS owing to introduction of rare earth elements into HLLW were studied. Though rare earth elements exhibit a small influence on the distribution coefficient for Cs+, they impair Cs-exchange capacity of Cs-IS to some extent. This interruption on the selectivity to Cs+ can be significantly eliminated provided an appropriate ratio of liquid to solid V:m is used.

  2. Quantifying exchange coupling in f-ion pairs using the diamagnetic substitution method

    Energy Technology Data Exchange (ETDEWEB)

    Lukens, Wayne W.; Walter, Marc D.


    One of the challenges in the chemistry of actinide and lanthanide (f-ion) is quantifying exchange coupling between f-ions. While qualitative information about exchange coupling may be readily obtained using the diamagnetic substitution approach, obtaining quantitative information is much more difficult. This article describes how exchange coupling may be quantified using the susceptibility of a magnetically isolated analog, as in the diamagnetic substitution approach, along with the anisotropy of the ground state as determined by EPR spectroscopy. Several examples are used to illustrate and test this approach.

  3. 离子交换法处理含镍电镀废水的工程应用%Engineering application of ion-exchange method to the treatment of nickel-containing electroplating wastewater

    Institute of Scientific and Technical Information of China (English)



    According to the characteristics of the quality and quantity of nickel-containing electroplating wastewater in a hygienic bath company in Hangzhou,the wastewater has been treated by the integrated treatment process,multi-medium pre-filtering+resin ion exchange. The project operating practice shows that when the quantity of the wastewa-ter to be treated is 6.5 m3/h,and the nickel mass concentration of the influent 100-150 mg/L,the filtration velocity of multi-medium filter 8.3 m/h,and the total residence time of ion exchange 37 min,the treated effluent nickel mass concentration is≤0.5 mg/L,turbidity≤1.0 NTU,electrical conductivity≤100μS/cm,meeting the limit value re-quirement of the Discharge Standard of Electroplatng Pollutants(GB 21900—2008). This project has the advantages of stable treatment effect and obvious environment benefit.%杭州某卫浴公司针对含镍电镀废水的水质和水量特点,采用了多介质预过滤与树脂离子交换相结合的处理工艺对其进行处理. 工程运行实践表明,在处理废水量为6.5 m3/h,进水镍质量浓度为100~150 mg/L,多介质过滤器滤速为8.3 m/h,离子交换总停留时间为37 min的条件下,处理出水镍质量浓度≤0.5 mg/L,浊度≤1.0 NTU,电导率≤100μS/cm,达到《电镀污染物排放标准》(GB 21900—2008)的限值要求.该工程具有处理效果稳定和环境效益明显的优点.

  4. Modelisation of the contribution of the Na/Ca exchanger to cell membrane potential and intracellular ion concentrations. (United States)

    Bahlouli, S; Hamdache, F; Riane, H


    Modelisation plays a significant role in the study of ion transfer through the cell membrane and in the comprehension of cellular excitability. We were interested in the selective ion transfers through the K(Ca), Na(v), Ca(v) channels and the Na/Ca exchanger (NCX). The membrane behaves like an electric circuit because of the existence of ion gradients maintained by the cell. The non-linearity of this circuit gives rise to complex oscillations of the membrane potential. By application of the finite difference method (FDM) and the concept of percolation we studied the role of the NCX in the regulation of the intracellular Ca(2+) concentration and the oscillations of the membrane potential. The fractal representation of the distribution of active channels allows us to follow the diffusion of intracellular Ca(2+) ions. These calculations show that the hyperpolarization and the change in the burst duration of the membrane potential are primarily due to the NCX.


    Institute of Scientific and Technical Information of China (English)

    YuXintian; SunZhaoxiang


    In this paper,a new complex inorganic ion exchanger Titanium Phosphate-Ammonium Tungstophosphate(abbreviated as Tip-AWP) was synthesized,whose exchange character and chemical structure were studied.This compound exhibits high exchange capacity and selectivity for Cs+,its exchange capacity accains 0.95 mmol/g in the medium of 0.1mol/L HNO3,and which almost doesn′t change in the 1AW imitated waste solution.There are no change in exchange capacity and structute after several times of exchanging,eluting,regenerating,which is of great importance to the separation and uptaking of radio-nuclides.Further more,this exchanger has good thermal and redioactive stability.

  6. Composite Membranes Containing Nanoparticles of Inorganic Ion Exchangers for Electrodialytic Desalination of Glycerol (United States)

    Dzyazko, Yu S.; Rozhdestvenska, L. M.; Vasilyuk, S. L.; Kudelko, K. O.; Belyakov, V. N.


    Composite membranes were obtained by modification of heterogeneous polymer cation and anion-exchange membranes with nanoparticles of zirconium hydrophosphate and hydrated zirconium dioxide, respectively. The ion-exchange materials were investigated with the methods of electron microscopy, potentiometry, voltammetry, and impedance spectroscopy. Single nanoparticles, which were precipitated in aqueous media, form aggregates, when the composites are in a contact with polar organic solvent. Both single nanoparticles (up to 10 nm) and their aggregates (up to 200 nm) were precipitated in ion-exchange polymers in glycerol media. Non-aggregated nanoparticles improve electrical conductivity of the ion-exchange materials, the aggregates are barriers against fouling. The membranes were applied to NaCl removal from highly concentrated glycerine-water mixture containing organic additives (byproduct of biodiesel production). As opposite to pristine materials, the composites demonstrate stability against fouling.

  7. Preparation and emanation properties of an ion-exchanged solid thoron source. (United States)

    Tang, F; Zhuo, W; He, L; Zhao, C; Xu, Y


    For the calibration purpose of thoron ((220)Rn) measurements, solid sources with constant (220)Rn emanation are generally desired. In this study, Th(4+) in the thorium nitrate powder was successfully exchanged to the surfaces of sodium benzenesulphonate resins with a bead diameter of ∼0.5 mm by using the ion-exchange method. Tests of (220)Rn emanating from the ion-exchanged resin indicated that the emanation rates were nearly constant, provided both the air humidity and air temperature were controlled. As the resin can be easily prepared to be of various sizes and activities of sources, the ion-exchanged resin is considered as a promising standard source for calibrations of (220)Rn measurements.

  8. Preparation of bioconjugates by solid-phase conjugation to ion exchange matrix-adsorbed carrier proteins

    DEFF Research Database (Denmark)

    Houen, G.; Olsen, D.T.; Hansen, P.R.;


    A solid-phase conjugation method utilizing carrier protein bound to an ion exchange matrix was developed. Ovalbumin was adsorbed to an anion exchange matrix using a batch procedure, and the immobilized protein was then derivatized with iodoacetic acid N-hydroxysuccinimid ester. The activated......, and immunization experiments with the eluted conjugates showed that the more substituted conjugates gave rise to the highest titers of glutathione antibodies. Direct immunization with the conjugates adsorbed to the ion exchange matrix was possible and gave rise to high titers of glutathione antibodies. Conjugates...... of ovalbumin and various peptides were prepared in a similar manner and used for production of peptide antisera by direct immunization with the conjugates bound to the ion exchanger. Advantages of the method are its solid-phase nature, allowing fast and efficient reactions and intermediate washings...

  9. Separation of hemicellulose-derived saccharides from wood hydrolysate by lime and ion exchange resin. (United States)

    Wang, Xiaojun; Zhuang, Jingshun; Fu, Yingjuan; Tian, Guoyu; Wang, Zhaojiang; Qin, Menghua


    A combined process of lime treatment and mixed bed ion exchange was proposed to separate hemicellulose-derived saccharides (HDS) from prehydrolysis liquor (PHL) of lignocellulose as value added products. The optimization of lime treatment achieved up to 44.2% removal of non-saccharide organic compounds (NSOC), mainly colloidal substances, with negligible HDS degradation at 0.5% lime level and subsequent neutralization by phosphoric acid. The residual NSOC and calcium ions in lime-treated PHL were eliminated by mixed bed ion exchange. The breakthrough curves of HDS and NSOC showed selective retention toward NSOC, leading to 75% HDS recovery with 95% purity at 17 bed volumes of exchange capacity. In addition, macroporous resin showed higher exchange capacity than gel resin as indicated by the triple processing volume. The remarkable selectivity of the combined process suggested the feasibility for HDS separation from PHL.

  10. Electrochemically Controlled Ion-exchange Property of Carbon Nanotubes/Polypyrrole Nanocomposite in Various Electrolyte Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Daiwon [Pacific Northwest National Laboratory, 902 Battelle Boulevard P.O. Box 999 Richland WA 99352 USA; Zhu, Chengzhou [School of Mechanical and Materials Engineering, Washington State University, Pullman, Washington 99164-2920 United States; Fu, Shaofang [School of Mechanical and Materials Engineering, Washington State University, Pullman, Washington 99164-2920 United States; Du, Dan [School of Mechanical and Materials Engineering, Washington State University, Pullman, Washington 99164-2920 United States; Engelhard, Mark H. [Pacific Northwest National Laboratory, 902 Battelle Boulevard P.O. Box 999 Richland WA 99352 USA; Lin, Yuehe [Pacific Northwest National Laboratory, 902 Battelle Boulevard P.O. Box 999 Richland WA 99352 USA; School of Mechanical and Materials Engineering, Washington State University, Pullman, Washington 99164-2920 United States


    The electrochemically controlled ion-exchange properties of multi-wall carbon nanotube (MWNT)/electronically conductive polypyrrole (PPy) polymer composite in the various electrolyte solutions have been investigated. The ion-exchange behavior, rate and capacity of the electrochemically deposited polypyrrole with and without carbon nanotube (CNT) were compared and characterized using cyclic voltammetry (CV), chronoamperometry (CA), electrochemical quartz crystal microbalance (EQCM), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). It has been found that the presence of carbon nanotube backbone resulted in improvement in ion-exchange rate, stability of polypyrrole, and higher anion loading capacity per PPy due to higher surface area, electronic conductivity, porous structure of thin film, and thinner film thickness providing shorter diffusion path. Chronoamperometric studies show that electrically switched anion exchange could be completed more than 10 times faster than pure PPy thin film. The anion selectivity of CNT/PPy film is demonstrated using X-ray photoelectron spectroscopy (XPS).

  11. Effects of magnetic ion-exchange resin addition during coagulation on floc properties and membrane filtration. (United States)

    Choi, Yang Hun; Kweon, Ji Hyang; Jeong, Young Mi; Kwon, Soonbuhm; Kim, Hyung-Soo


    The application of magnetic ion-exchange resin (MIEX) during chemical coagulation was investigated for the removal of organic matters responsible for fouling in membrane processes. Two different coagulants were used-polyaluminium chloride (PAC1) and polyaluminum chloride silicate (PACS). The MIEX addition during coagulation with both PAC1 and PACS considerably enhanced removal of dissolved organic carbon. Coagulation with MIEX treatment substantially removed all portions of natural organic matter (NOM), while the MIEX treatment alone effectively removed the hydrophobic and transphilic portions of NOM. The enhanced NOM removal by PAC1 coagulation with the addition of MIEX had positive effects on membrane flux at moderate transmembrane pressure conditions. However, the almost identical flux patterns were reported in the experiments of coagulation with PACS and PACS with MIEX addition. The results of the specific cake resistances indicated that the MIEX addition substantially decreased the resistances. The larger size distributions of PAC1 with MIEX corresponded well with the flux improvement.

  12. Ion exchange synthesis and thermal characteristics of some $[\\text{N}^{+}_{2222}]$ based ionic liquids

    Indian Academy of Sciences (India)

    Vasishta D Bhatt; Kuldip Gohil


    Eight salts were obtained by reacting tetraethylammonium cation $[\\text{N}^{+}_{2222}]$ with inorganic anions like BF$^{-}_{4}$, NO$^{-}_{3}$, NO$^{-}_{2}$, SCN-, BrO$^{-}_{3}$, IO$^{-}_{3}$, PF$^{-}_{6}$ and HCO$^{-}_{3}$ using ion exchange method. These ionic liquids (ILs) were characterized using thermal methods, infrared spectroscopy and densitometry. Thermophysical properties such as density, coefficient of volume expansion, heat of fusion, heat capacity and thermal energy storage capacity were determined. Thermal conductivity of the samples was determined both in solid and liquid phases. Owing to high values of thermal energy storage capacity coupled with handsome liquid phase thermal conductivity, ILs under investigation were recommended as materials for thermal energy storage (TES) as well as heat transfer applications.

  13. Ion exchange separation of chromium from natural water matrix for stable isotope mass spectrometric analysis (United States)

    Ball, J.W.; Bassett, R.L.


    A method has been developed for separating the Cr dissolved in natural water from matrix elements and determination of its stable isotope ratios using solid-source thermal-ionization mass spectrometry (TIMS). The separation method takes advantage of the existence of the oxidized form of Cr as an oxyanion to separate it from interfering cations using anion-exchange chromatography, and of the reduced form of Cr as a positively charged ion to separate it from interfering anions such as sulfate. Subsequent processing of the separated sample eliminates residual organic material for application to a solid source filament. Ratios for 53Cr/52Cr for National Institute of Standards and Technology Standard Reference Material 979 can be measured using the silica gel-boric acid technique with a filament-to-filament standard deviation in the mean 53Cr/52Cr ratio for 50 replicates of 0.00005 or less. (C) 2000 Elsevier Science B.V. All rights reserved.

  14. Effect of modulator sorption on gradient shape in ion-exchange chromatography (United States)

    Velayudhan, A.; Ladisch, M. R.; Mitchell, C. A. (Principal Investigator)


    Mobile phase additives, or modulators, are used in gradient elution chromatography to facilitate separation and reduce separation time. The modulators are usually assumed to be linearly adsorbed or unadsorbed. Here, the consequences of nonlinear modulator adsorption are examined for ion-exchange gradient elution through a series of simulations. Even when the buffer salt is identical to the modulator salt, gradient deformation is observed; the extent of deformation increases as the volume of the feed is increased. When the modulator salt is different from the buffer salt, unusual effects are observed, and the chromatograms are quite different from those predicted by classical gradient elution theory. In particular, local increases in the buffer concentration are found between feed bands, and serve to improve the separation. These effects become more pronounced as the feed volume increases, and could therefore prove valuable in preparative applications.

  15. Standard practice for The separation of americium from plutonium by ion exchange

    CERN Document Server

    American Society for Testing and Materials. Philadelphia


    1.1 This practice describes the use of an ion exchange technique to separate plutonium from solutions containing low concentrations of americium prior to measurement of the 241Am by gamma counting. 1.2 This practice covers the removal of plutonium, but not all the other radioactive isotopes that may interfere in the determination of 241Am. 1.3 This practice can be used when 241Am is to be determined in samples in which the plutonium is in the form of metal, oxide, or other solid provided that the solid is appropriately sampled and dissolved (See Test Methods C758, C759, and C1168). 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  16. Fractioning electrodialysis: a current induced ion exchange process

    NARCIS (Netherlands)

    Galama, A.H.; Daubaras, G.; Burheim, O.S.; Rijnaarts, H.; Post, J.W.


    In desalination often multi ionic compositions are encountered. A preferential removal of multivalent ions over monovalent ions can be of interest to prevent scaling in the desalination process. Recently, a novel fractionating electrodialysis stack is described by Zhang et al., 2012 (in Sep. purify.

  17. Fractioning electrodialysis : a current induced ion exchange process

    NARCIS (Netherlands)

    Galama, A. H.; Daubaras, G.; Burheim, O. S.; Rijnaarts, H. H. M.; Post, J. W.


    In desalination often multi ionic compositions are encountered. A preferential removal of multivalent ions over monovalent ions can be of interest to prevent scaling in the desalination process. Recently, a novel fractionating electrodialysis stack is described by Zhang et al., 2012 (in Sep. purify.

  18. Continuous Separation of Cesium Based on NiHCF/PTCF Electrode by Electrochemically Switched Ion Exchange

    Institute of Scientific and Technical Information of China (English)

    孙斌; 郝晓刚; 王忠德; 张忠林; 刘世斌; 官国清


    Nickel hexacyanoferrate (NiHCF) film was synthesized on porous three-dimensional carbon felt (PTCF) substrate by repetitious batch chemical depositions, and the NiHCF/PTCF electrode was used as electrochemically switched ion exchange (ESIX) electrode in a packed bed for continuous separation for cesium ions. The morphologies of the prepared electrodes were characterized by scanning electron microscopy and the effects of solution concentration on the ion-exchange capacity of the electrodes were investigated by cyclic voltammetry technique. Cycling stability and long-term storage stability of NiHCF/PTCF electrodes were also studied. The NiHCF/PTCF electrodes with excellent ion-exchange ability were used to assemble a diaphragm-isolated ESIX reactor for cesium separation. Continuous separation of cesium and regeneration of NiHCF/PTCF electrode based on the diaphragm-isolated reactor were performed in a laboratory-scale two-electrode system.

  19. The influence of silver ion exchange on the luminescence properties of Er-Yb silicate glasses (United States)

    Stanek, S.; Nekvindova, P.; Svecova, B.; Vytykacova, S.; Mika, M.; Oswald, J.; Barkman, O.; Spirkova, J.


    A set of zinc-silicate glasses with different ratios of Er-Yb as well amount of Zn was fabricated. The preparation of silver doped glasses was carried out using the Ag-Na ion-exchange method to enhance Er-Yb luminescence properties of the material. The samples were also annealed for 1-5 h to further support the creation of silver nanoparticles. Intensive absorption at 980 nm was observed in absorption spectra after ion exchange and annealing as well. Also luminescence spectra in the near-infrared range were measured and results showed positive effect of ion exchange process on luminescence properties. Luminescence intensity at 1530 nm was increased almost three times. Possible mechanisms responsible for the increase of the luminescence intensity are also discussed in this paper. We suggest that the enhancement of erbium luminescence intensity is caused by the energy transfer from isolated Ag+ ions to Er.

  20. Anion Effects on the Ion Exchange Process and the Deformation Property of Ionic Polymer Metal Composite Actuators

    Directory of Open Access Journals (Sweden)

    Wataru Aoyagi


    Full Text Available An ionic polymer-metal composite (IPMC actuator composed of a thin perfluorinated ionomer membrane with electrodes plated on both surfaces undergoes a large bending motion when a low electric field is applied across its thickness. Such actuators are soft, lightweight, and able to operate in solutions and thus show promise with regard to a wide range of applications, including MEMS sensors, artificial muscles, biomimetic systems, and medical devices. However, the variations induced by changing the type of anion on the device deformation properties are not well understood; therefore, the present study investigated the effects of different anions on the ion exchange process and the deformation behavior of IPMC actuators with palladium electrodes. Ion exchange was carried out in solutions incorporating various anions and the actuator tip displacement in deionized water was subsequently measured while applying a step voltage. In the step voltage response measurements, larger anions such as nitrate or sulfate led to a more pronounced tip displacement compared to that obtained with smaller anions such as hydroxide or chloride. In AC impedance measurements, larger anions generated greater ion conductivity and a larger double-layer capacitance at the cathode. Based on these mechanical and electrochemical measurements, it is concluded that the presence of larger anions in the ion exchange solution induces a greater degree of double-layer capacitance at the cathode and results in enhanced tip deformation of the IPMC actuators.

  1. Composite optical waveguide composed of a tapered film of bromothymol blue evaporated onto a potassium ion-exchanged waveguide and its application as a guided wave absorption-based ammonia-gas sensor. (United States)

    Qi, Z M; Yimit, A; Itoh, K; Murabayashi, M; Matsuda, N; Takatsu, A; Kato, K


    For what is the first time to our knowledge, we have successfully evaporated a tapered film of bromothymol blue (BTB) onto a potassium ion-exchanged (PIE) waveguide to form a composite optical waveguide (COWG) for trace-ammonia detection. The BTB film has a high refractive index (1.69) and a smooth surface and is transparent to a 633-nm laser beam in air. In the COWG structure, the BTB film serves as a single-mode waveguide, and adiabatic transition of the TE(0) mode was realized between the BTB waveguide and the PIE waveguide with both BTB tapers. In the presence of ammonia, the BTB film changes color from yellow to blue, which causes absorption of the 633-nm guided wave. Our experimental results demonstrate that such a guided wave absorption-based ammonia-gas sensor is much more sensitive than one based on evanescent-wave absorption. A detection limit of part in 10(9) of ammonia has been realized for a BTB film-PIE glass COWG.

  2. Lithium-ion batteries fundamentals and applications

    CERN Document Server

    Wu, Yuping


    Lithium-Ion Batteries: Fundamentals and Applications offers a comprehensive treatment of the principles, background, design, production, and use of lithium-ion batteries. Based on a solid foundation of long-term research work, this authoritative monograph:Introduces the underlying theory and history of lithium-ion batteriesDescribes the key components of lithium-ion batteries, including negative and positive electrode materials, electrolytes, and separatorsDiscusses electronic conductive agents, binders, solvents for slurry preparation, positive thermal coefficient (PTC) materials, current col

  3. Thin Robust Anion Exchange Membranes for Fuel Cell Applications (United States)


    provide inexpensive compact power from a wider variety of fuels than is possible with a proton exchange membrane (PEM) fuel cell, has continued aqueous solution. Interestingly though, while the proton transfer events in the anion exchange membrane are more frequent as would be ECS...release; distribution is unlimited. (Invited) Thin Robust Anion Exchange Membranes for Fuel Cell Applications The views, opinions and/or findings

  4. Central metal ion exchange in a coordination polymer based on lanthanide ions and di(2-ethylhexyl)phosphoric acid: exchange rate and tunable affinity. (United States)

    Tasaki-Handa, Yuiko; Abe, Yukie; Ooi, Kenta; Tanaka, Mikiya; Wakisaka, Akihiro


    In this paper the exchange of lanthanide(III) ions (Ln(3+)) between a solution and a coordination polymer (CP) of di(2-ethylhexyl)phosphoric acid (Hdehp), [Ln(dehp)3], is studied. Kinetic and selectivity studies suggest that a polymeric network of [Ln(dehp)3] has different characteristics than the corresponding monomeric complex. The reaction rate is remarkably slow and requires over 600 h to reach in nearly equilibrium, and this can be explained by the polymeric crystalline structure and high valency of Ln(3+). The affinity of the exchange reaction reaches a maximum with the Ln(3+) possessing an ionic radius 7% smaller than that of the central Ln(3+), therefore, the affinity of the [Ln(dehp)3] is tunable based on the choice of the central metal ion. Such unique affinity, which differs from the monomeric complex, can be explained by two factors: the coordination preference and steric strain caused by the polymeric structure. The latter likely becomes predominant for Ln(3+) exchange when the ionic radius of the ion in solution is smaller than the original Ln(3+) by more than 7%. Structural studies suggest that the incoming Ln(3+) forms a new phase though an exchange reaction, and this could plausibly cause the structural strain.

  5. Selective separation of sodium ions from a mixture with phenylalanine by Donnan dialysis with a profiled sulfogroup cation exchange membrane (United States)

    Vasil'eva, V. I.; Goleva, E. A.


    The possibility of separating ions of metal from a mixture with ampholyte (an amino acid) by Donnan dialysis with an MK-40 sulfogroup cation exchange membrane is demonstrated. Conditions ensuring the selectivity and intensity of the mass transfer of sodium ions from a mixture with bipolar phenylalanine ions into a diffusate containing hydrochloric acid through a cation exchange membrane are found.

  6. Silicene for Na-ion battery applications

    KAUST Repository

    Zhu, Jiajie


    Na-ion batteries are promising candidates to replace Li-ion batteries in large scale applications because of the advantages in natural abundance and cost of Na. Silicene has potential as the anode in Li-ion batteries but so far has not received attention with respect to Na-ion batteries. In this context, freestanding silicene, a graphene-silicene-graphene heterostructure, and a graphene-silicene superlattice are investigated for possible application in Na-ion batteries, using first-principles calculations. The calculated Na capacities of 954mAh/g for freestanding silicene and 730mAh/g for the graphenesilicene superlattice (10% biaxial tensile strain) are highly competitive and potentials of >0.3 V against the Na/Na potential exceed the corresponding value of graphite. In addition, the diffusion barriers are predicted to be <0.3 eV.

  7. Silicene for Na-ion battery applications (United States)

    Zhu, Jiajie; Schwingenschlögl, Udo


    Na-ion batteries are promising candidates to replace Li-ion batteries in large scale applications because of the advantages in natural abundance and cost of Na. Silicene has potential as the anode in Li-ion batteries but so far has not received attention with respect to Na-ion batteries. In this context, freestanding silicene, a graphene-silicene-graphene heterostructure, and a graphene-silicene superlattice are investigated for possible application in Na-ion batteries, using first-principles calculations. The calculated Na capacities of 954 mAh/g for freestanding silicene and 730 mAh/g for the graphene-silicene superlattice (10% biaxial tensile strain) are highly competitive and potentials of \\gt 0.3 {{V}} against the Na{}+/Na potential exceed the corresponding value of graphite. In addition, the diffusion barriers are predicted to be \\lt 0.3 {eV}.

  8. Lithium-ion batteries advances and applications

    CERN Document Server

    Pistoia, Gianfranco


    Lithium-Ion Batteries features an in-depth description of different lithium-ion applications, including important features such as safety and reliability. This title acquaints readers with the numerous and often consumer-oriented applications of this widespread battery type. Lithium-Ion Batteries also explores the concepts of nanostructured materials, as well as the importance of battery management systems. This handbook is an invaluable resource for electrochemical engineers and battery and fuel cell experts everywhere, from research institutions and universities to a worldwi

  9. Thermodynamics of ion exchange equilibrium for some uni-univalent and divalent reaction systems using strongly basic anion exchange resin Indion FF-IP

    Directory of Open Access Journals (Sweden)

    P.U. Singare


    Full Text Available The study on thermodynamics of ion exchange equilibrium for uni-univalent Cl-/I-, Cl-/Br-, and uni-divalent Cl-/SO42-, Cl-/C2O42- reaction systems was carried out using ion exchange resin Indion FF-IP. The equilibrium constant K was calculated by taking into account the activity coefficient of ions both in solution as well as in the resin phase. For uni-univalent ion exchange reaction systems, the equilibrium constant K’ were also calculated by considering mole fraction of ions in the resin phase. The K values calculated for uni-univalent and uni-divalent anion exchange reaction systems were observed to increase with rise in temperature, indicating the endothermic exchange reactions having enthalpy values of 22.45, 28.57, 17.84, 15.97 kJ/mol, respectively.

  10. Ion exchange properties of Wyodak premium coal samples

    Energy Technology Data Exchange (ETDEWEB)

    Vorres, K.S.


    Low rank coals (lignite and subbituminous) contain exchangeable cations. A sample of {minus}20+200 mesh Argonne Premium Wyodak coal was washed with nitric acid in a burette fitted with a coarse glass frit at the base of the graduations to remove the exchangeable cations from the system. The eluent was passed to a flow-through pH electrode and a titration curve was obtained on a computer file. A series of electrodes (pH, calcium, sodium and potassium) were used in separate experiments to follow the elution from the coal. Some implications for coal structure are also indicated.

  11. Experimental measurement and modeling of the distribution of solvent and ions between an aqueous phase and an ion exchange resin

    DEFF Research Database (Denmark)

    Christensen, Søren Gregers; Thomsen, Kaj


    The distribution of solutes and solvent between an aqueous solution of salt and an ion exchange resin has been measured at ambient temperature. The experiments have been performed for aqueous solutions of KNO3, KCl, Ca(NO3)2 and CaCl2 in the concentration range of 0-3N. The absorption has been...

  12. Effect of field cooling process and ion-beam bombardment on the exchange bias of NiCo/(Ni, Co)O bilayers

    Energy Technology Data Exchange (ETDEWEB)

    Li, X. [Department of Electrical and Electronic Engineering, The University of Hong Kong (Hong Kong); Lin, K.-W., E-mail: [Department of Materials Science and Engineering, National Chung Hsing University, Taichung 402, Taiwan (China); Liu, H.-Y. [Department of Materials Science and Engineering, National Chung Hsing University, Taichung 402, Taiwan (China); Wei, D.-H. [National Synchrotron Radiation Research Center, Hsinchu 300, Taiwan (China); Li, G.J. [Department of Electrical and Electronic Engineering, The University of Hong Kong (Hong Kong); Pong, P.W.T., E-mail: [Department of Electrical and Electronic Engineering, The University of Hong Kong (Hong Kong)


    The research on exchange coupled ferromagnetic/antiferromagnetic (FM/AF) bilayers has been the foundation of spintronic applications such as hard disk reading heads and spin torque oscillators. In order to further explore the exchange bias behavior of NiCo/(Ni, Co)O bilayers, effect of field cooling process, magnetic angular dependence, and ion-beam bombardment was investigated. The difference in film composition resulted in remarkable distinction in crystalline structures and domain patterns. The exchange bias field (H{sub ex}) in the bilayer systems exhibited a strong angular dependence. The negative H{sub ex} after a field cooling process indicated that the polarity of H{sub ex} can be defined by aligning the magnetization orientation of the FM NiCo layer with the applied field. Moreover, enhanced exchange bias effect was observed in the NiCo/(Ni, Co)O bilayers that resulted from the surface of the (Ni, Co)O layers bombarded with different Ar{sup +} ion-beam energies using End-Hall voltages from 0 V to 150 V. The interface spin structures as well as the surface domain patterns were altered by the ion-beam bombardment process. These results indicated that the exchange bias field of NiCo/(Ni, Co)O bilayer systems could be tailored by field cooling process, angular dependence of magnetic properties, and post ion-beam bombardment. - Highlights: • Strong angular dependence was observed in the exchange bias of NiCo/(Ni, Co)O bilayers. • The field cooling process resulted in negative exchange bias. • Moderate ion-beam bombardment on (NiCo)O layers enhanced exchange bias at 298 K. • High-energy ion bombardment strengthened the exchange coupling in field cooled bilayer. • The structural deformation was responsible for the change in magnetic properties.

  13. Data Exchange over Web-based Applications with DXL

    NARCIS (Netherlands)

    Zwol, van Roelof; Jeronimus, V.; Fokkinga, M.; Apers, Peter M.G.; Lacroix, Z.


    With large volumes of data being exchanged on the Internet, query languages are needed to bridge the gap between databases and the web. Furthermore, the differentiation in data types used by webbased applications is ever growing, despite all standardization efforts. The Data eXchange Language (DXL)

  14. Modelling of graded index waveguide fabricated by ion exchange on Er3+ doped glass

    Institute of Scientific and Technical Information of China (English)

    Shao Gong-Wang; Jin Guo-Liang


    A general numerical tool, based on thermal diffusion equation and full-vectorial eigen-mode equation, has been presented for the systematic analysis of graded index channel waveguide fabricated by ion exchange on Er3+ doped glass. Finite difference method with full-vectorial formulation (FV-FDM) is applied to solving the full-vectorial modes of graded index channel waveguide for the first time. The coupled difference equations based on magnetic fields in FV-FDM are derived from the Taylor series expansion and accurate formulation of boundary conditions. Hybrid nature of vectorial guided modes for both pump (980 nm) and signal light (1550 nm) are demonstrated by the simulation. Results show that the fabrication parameters of ion exchange, such as channel opening width and time ratio of second step to first step in ion exchange, have large influence on the properties of waveguide. By optimizing the fabrication parameters, maintenance of monomode for signal light and improvement of the gain dynamics can be achieved in Er3+ doped waveguide amplifier (EDWA) fabricated by ion exchange technique. This theoretical model is significant for the design and fabrication of EDWA with ion exchange technique. Furthermore, a single polarization EDWA, which operates at wavelength from 1528 nm to 1541 nm for HE polarization, is numerically designed.

  15. Construction and Ion Exchange Properties of Supramolecular Complexes with Organic Ligands and Metal Ions

    Institute of Scientific and Technical Information of China (English)

    SUN; WeiYin


    Supramolecular architectures with specific topologies such as closed threedimensional molecular cages present a large range of applications in material science, medicine and chemical technology.1,2 In the past decades, a number of such frameworks, e.g. M6L4, M12L8 and M18L6, have been synthesized by assembly of organic ligands with transitional metal salts.3-5 However, the M3L2 type cage-like complexes are not well known up to now.6,7 We report herein the generation of M3L2 type cages by tripodal ligands and various metal salts, and the anion exchange, molecular recognition properties of these metallosupramolecular cages.  ……

  16. Construction and Ion Exchange Properties of Supramolecular Complexes with Organic Ligands and Metal Ions

    Institute of Scientific and Technical Information of China (English)

    SUN WeiYin; FAN Jian


    @@ Supramolecular architectures with specific topologies such as closed threedimensional molecular cages present a large range of applications in material science, medicine and chemical technology.1,2 In the past decades, a number of such frameworks, e.g. M6L4, M12L8 and M18L6, have been synthesized by assembly of organic ligands with transitional metal salts.3-5 However, the M3L2 type cage-like complexes are not well known up to now.6,7 We report herein the generation of M3L2 type cages by tripodal ligands and various metal salts, and the anion exchange, molecular recognition properties of these metallosupramolecular cages.

  17. Study of plasma off-gas treatment from spent ion exchange resin pyrolysis. (United States)

    Castro, Hernán Ariel; Luca, Vittorio; Banchi, Hugo Luis


    Polystyrene divinylbenzene-based ion exchange resins are employed extensively within nuclear power plants (NPPs) and research reactors for purification and chemical control of the cooling water system. To maintain the highest possible water quality, the resins are regularly replaced as they become contaminated with a range of isotopes derived from compromised fuel elements as well as corrosion and activation products including (14)C, (60)Co, (90)Sr, (129)I, and (137)Cs. Such spent resins constitute a major proportion (in volume terms) of the solid radioactive waste generated by the nuclear industry. Several treatment and conditioning techniques have been developed with a view toward reducing the spent resin volume and generating a stable waste product suitable for long-term storage and disposal. Between them, pyrolysis emerges as an attractive option. Previous work of our group suggests that the pyrolysis treatment of the resins at low temperatures between 300 and 350 °C resulted in a stable waste product with a significant volume reduction (>50%) and characteristics suitable for long-term storage and/or disposal. However, another important issue to take into account is the complexity of the off-gas generated during the process and the different technical alternatives for its conditioning. Ongoing work addresses the characterization of the ion exchange resin treatment's off-gas. Additionally, the application of plasma technology for the treatment of the off-gas current was studied as an alternative to more conventional processes utilizing oil- or gas-fired post-combustion chambers operating at temperatures in excess of 1000 °C. A laboratory-scale flow reactor, using inductively coupled plasma, operating under sub-atmospheric conditions was developed. Fundamental experiments using model compounds have been performed, demonstrating a high destruction and removal ratio (>99.99%) for different reaction media, at low reactor temperatures and moderate power


    Institute of Scientific and Technical Information of China (English)

    HuangXiwen; ShiFang; 等


    The adsorption characteristics of inosine from fermentation solution on anion exchange resin under the condition of different pH,resin type are investigated.Besides,the desorption conditions are studied under different temperature.The adsorption and desorption mechanism are described to obtain the optimum technological condition of inosine extraction.

  19. Kilogram-scale purification of americium by ion exchange

    Energy Technology Data Exchange (ETDEWEB)

    Wheelwright, E. J.


    Sequential anion and cation exchange processes have been used for the final purification of /sup 241/Am recovered during the reprocessing of aged plutonium metallurgical scrap. Plutonium was removed by absorption of Dowex 1, X-3.5 (30 to 50 mesh) anion exchange resin from 6.5 to 7.5 M HNO/sub 3/ feed solution. Following a water dilution to 0.75 to 1.0 M HNO/sub 3/, americium was absorbed on Dowex 50W, X-8 (50 to 100 mesh) cation exchange resion. Final purification was accomplished by elution of the absorbed band down 3 to 4 successive beds of the same resin, preloaded with Zn/sup 2 +/, with an NH/sub 4/OH buffered chelating agent. The recovery of mixed /sup 241/Am-/sup 243/Am from power reactor reprocessing waste has been demonstrated. Solvent extraction was used to recover a HNO/sub 3/ solution of mixed lanthanides and actinides from waste generated by the reprocessng of 13.5 tons of Shippingport Power Reactor blanket fuel. Sequential cation exchange band-displacement processes were then used to separate americium and curium from the lanthanides and then to separate approx. 60 g of /sup 244/Cm from 1000 g of mixed /sup 241/Am-/sup 243/Am.

  20. Energy exchange via multi-species streaming in laser-driven ion acceleration (United States)

    King, M.; Gray, R. J.; Powell, H. W.; Capdessus, R.; McKenna, P.


    Due to the complex electron dynamics and multiple ion acceleration mechanisms that can take place in the interaction of an ultra-intense laser pulse with a thin foil, it is possible for multiple charged particle populations to overlap in space with varying momentum distributions. In certain scenarios this can drive streaming instabilities such as the relativistic Buneman instability and the ion-ion acoustic instability. The potential for such instabilities to occur are demonstrated using particle-in-cell simulations. It is shown that if a population of ions can be accelerated such that it can propagate through other slowly expanding ion populations, energy exchange can occur via the ion-ion acoustic instability.

  1. Bactericidal and ammonia removal activity of silver ion-exchanged zeolite. (United States)

    Krishnani, K K; Zhang, Yu; Xiong, Laj; Yan, Yushan; Boopathy, Raj; Mulchandani, Ashok


    The antimicrobial activity of silver-zeolite against Escherichia coli, Vibrio harveyi, Vibrio cholerae and Vibrio parahaemolyticus was examined in liquid medium and agar well diffusion assays. The minimum inhibitory concentration for silver ion-exchanged zeolite against E. coli and V. harveyi was 40 μg/ml, and 50-60 μg/ml for V. cholerae and V. parahaemolyticus. The diameter of the inhibition zones for E. coli, V. harveyi, V. cholerae and V. parahaemolyticus, respectively, increased from 0.5 to 2.3 cm, 0.6 to 2.4 cm, 0.3 to 1.65 cm and 0.3 to 1.7 cm with increasing concentrations of silver ion-exchanged zeolite from 10 to 400 μg. Silver-zeolite removed 20-37% ammonia from aqueous solutions. This study suggests that silver ion-exchanged zeolite could impact disease and environmental management in shrimp aquaculture.

  2. Mathematical modeling of salt-gradient ion-exchange simulated moving bed chromatography for protein separations

    Institute of Scientific and Technical Information of China (English)



    The salt-gradient operation mode used in ion-exchange simulated moving bed chromatography (SMBC) can improve the efficiency of protein separations. A detailed model that takes into account any kind of adsorption/ion-exchange equilibrium, salt gradient, size exclusion, mass transfer resistance, and port periodic switching mechanism, was developed to simulate the complex dynamics. The model predictions were verified by the experimental data on upward and downward gradients for protein separations reported in the literature. All design and operating parameters (number, configuration, length and diameter of columns, particle size, switching period, flow rates of feed, raffinate, desorbent and extract, protein concentrations in feed, different salt concentrations in desorbent and feed) can be chosen correctly by numerical simulation. This model can facilitate the design, operation, optimization, control and scale-up of salt-gradient ion-exchange SMBC for protein separations.

  3. Livestock wastewater treatment by zeolite ion exchange and gamma-ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Ryul; Kim, Tak Hyun; Lee, Myun Joo [Radiation Research Center for Industry and Environment, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)


    Livestock wastewater containing high concentrations of organic matters and ammonia-nitrogen has been known as one of the recalcitrant wastewater. It is difficult to treat by conventional wastewater treatment techniques. This study was carried out to evaluate the feasibility of zeolite ion exchange and gamma-ray irradiation treatment of livestock wastewater. The removal efficiencies of SCOD{sub Cr} and NH3-N were significantly enhanced by gamma-ray irradiation after zeolite ion exchange as a pre-treatment. However, the effects of zeolite particle size on the SCOD{sub Cr} and NH{sub 3}-N removal efficiencies were insignificant. These results indicate that the combined process of zeolite ion exchange and gamma-ray irradiation has potential for the treatment of livestock wastewater.

  4. Synthesis, characterization and antimicrobial activity of alkaline ion-exchanged ZnO/bentonite nanocomposites

    Institute of Scientific and Technical Information of China (English)

    Hamideh Pouraboulghasem; Mohammad Ghorbanpour; Razieh Shayegh; Samaneh Lotfiman


    Nanocomposites of zinc/bentonite clay were synthesized for use as an antibacterial material by a quick and simple alkaline ion exchange method. The synthesis of zinc doped bentonite nanocomposite was accomplished by placing bentonite in a melting bath of ZnSO4 for 10, 20, 40, 60 and 90 min. The complexes were characterized by XRD, SEM and DRS. XRD analyses and SEM observations confirmed the diffusion of zinc to the clay surfaces. Antibacterial activity tests againstEscherichia coli showed that bentonite did not present any antibacterial properties, but after alkaline ion exchange treatment, inhibition was noted. The highest antibacterial activity was observed with ZnO/bentonite composite alkaline ion exchange for 60 and 90 min. Interestingly, the leaching test indicated that ZnO/bentonite did not present any risk for drinking water treatment.


    Institute of Scientific and Technical Information of China (English)



    In this paper,the self-regeneration process of the mixed resins consisting of cation and anion ion exchangers in the electrolialyser of the packed bed is analyzed,and an electric regeneration method is put forward to supply the desalinated water by mixed bed.The electric regeneration technology is a new one used for regeneration of the exhausted ion exchangers in the mixed bed,instead of the traditional regenerating process by using acid and alkali liquor.Electric energy is consumed to regenerate the ion exchangers loaded by salts from water treatment without any chemicals-acid and alkali.The advantage of the electric regeneration process exhibited convenient operation,no discharge any waste,and therefore no pollution to the receiving water body and the environmental ground.

  6. Influence of anodic surface treatment of activated carbon on adsorption and ion exchange properties

    Energy Technology Data Exchange (ETDEWEB)

    Park, S.J.; Kim, K.D.


    The effect of anodic surface treatment of activated carbon on adsorption and ion exchange characteristics was investigated in the condition of 35 wt% NaOH electrolyte for 60 s. The acid and base values were determined by a titration technique, and surface and pore structures were studied in terms of BET volumetric measurement with N{sub 2} adsorption. The ion exchange capacity of the anodized activated carbons was characterized by a dry weight capacity technique. It was observed that an increase in current intensity leads to an increase in the surface functional groups of activated carbons, resulting in increasing pH, acid-base values, and anion-cation exchange capacities, without significant change of surface and pore structures (i.e., specific surface area, total pore volume, micropore volume, and average pore diameter). Also, anodically treated activated carbons are more effectively evaluated on the base value or cation exchange capacity than on the oppose properties in this electrolytic system.

  7. Chromium (III) recovery from waste acid solution by ion exchange processing using Amberlite IR-120 resin: batch and continuous ion exchange modelling


    Alguacil,Francisco José; Alonso Gámez, Manuel; Lozano, Kuis Javier


    The use of ion exchange technology was studied to remove chromium (III) from acidic waste solution by Amberlite IR-120 resin. Batch and column experimental tests were conducted to provide data for theoretical models and verify the system performance of the adsorption process. Results of batch equilibrium tests indicated that Langmuir isotherm describes well the adsorption process, whereas experimental data also provide evidence that, under the present experimental conditions, chro...

  8. High performance ion chromatography of haloacetic acids on macrocyclic cryptand anion exchanger. (United States)

    Bruzzoniti, Maria Concetta; De Carlo, Rosa Maria; Horvath, Krisztian; Perrachon, Daniela; Prelle, Ambra; Tófalvi, Renáta; Sarzanini, Corrado; Hajós, Péter


    A new high performance ion chromatographic method has been developed for the separation of the nine chlorinated-brominated haloacetic acids (HAAs) that are the disinfection by-products of chlorination of drinking water, using a macrocycle-based adjustable-capacity anion-exchange separator column (IonPac Cryptand A1). A gradient method based on theoretical and experimental considerations has been optimized in which 10 mM NaOH-LiOH step gradient was performed at the third minute of the analysis. The optimized method allowed us to separate the nine HAAs and seven possibly interfering inorganic anions in less than 25 min with acceptable resolution. The minimum concentrations detectable for HAAs were between 8.0 (MBA) and 210 (TBA) microg L(-1), with linearity included between 0.9947 (TBA) and 0.9998 (MBA). To increase sensitivity, a 25-fold preconcentration step on a reversed phase substrate (LiChrolut EN) has been coupled. Application of this method to the analysis of haloacetic acids in real tap water samples is illustrated.

  9. Electrochemical Ion-Exchange Regeneration and Fluidized Bed Crystallization for Zero-Liquid-Discharge Water Softening. (United States)

    Chen, Yingying; Davis, Jake R; Nguyen, Chi H; Baygents, James C; Farrell, James


    This research investigated the use of an electrochemical system for regenerating ion-exchange media and for promoting the crystallization of hardness minerals in a fluidized bed crystallization reactor (FBCR). The closed-loop process eliminates the creation of waste brine solutions that are normally produced when regenerating ion-exchange media. A bipolar membrane electrodialysis stack was used to generate acids and bases from 100 mM salt solutions. The acid was used to regenerate weak acid cation (WAC) ion-exchange media used for water softening. The base solutions were used to absorb CO2 gas and to provide a source of alkalinity for removing noncarbonate hardness by WAC media operated in H(+) form. The base solutions were also used to promote the crystallization of CaCO3 and Mg(OH)2 in a FBCR. The overall process removes hardness ions from the water being softened and replaces them with H(+) ions, slightly decreasing the pH value of the softened water. The current utilization efficiency for acid and base production was ∼75% over the operational range of interest, and the energy costs for producing acids and bases were an order of magnitude lower than the costs for purchasing acid and base in bulk quantities. Ion balances indicate that the closed-loop system will accumulate SO4(2-), Cl(-), and alkali metal ions. Acid and base balances indicate that for a typical water, small amounts of base will be accumulated.

  10. Metal ion exchange process by natural and modified clinoptilolite

    Energy Technology Data Exchange (ETDEWEB)

    Athanasiadis, K.; Petter, C.; Hilliges, R.; Helmreich, B.; Wilderer, P.A. [TU Muenchen (Germany). Lehrstuhl fuer Wasserguete- und Abfallwirtschaft


    Clinoptilolite, one of the most frequently studied natural zeolites, was shown to have high selectivity for certain heavy metals such as lead, cadmium and nickel. The aim of this study is to present equilibrium and kinetic data for Pb{sup 2+}, Cu{sup 2+} and Zn{sup 2+} exchange on natural and modified clinoptilolite for two different pH values. Selectivity series and kinetic data from these three heavy metals are presented. (orig.)

  11. Tungsten Recovery from Spent SCR Catalyst Using Alkaline Leaching and Ion Exchange

    Directory of Open Access Journals (Sweden)

    Wen-Cheng Wu


    Full Text Available The recovery of tungsten (W from a honeycomb-type spent selective catalytic reduction (SCR catalyst using an alkaline leaching–ion exchange method was investigated. Spent SCR catalyst mainly consists of TiO2 and other oxides (6.37% W, 1.57% vanadium (V, and 2.81% silicon (Si, etc.. The ground catalyst was leached at the optimal conditions, as follows: NaOH concentration of 0.3 kg/kg of catalyst, pulp density of 3%, leaching temperature of 70 °C, particle size of −74 μm, and leaching time of 30 min. In this study, the leaching rate values of V and W under the above conditions were 87 wt %, and 91 wt %, respectively. The pregnant solution was then passed through a strong base anion exchange resin (Amberlite IRA900. At high pH conditions, the use of strong base anion exchange resin led to selective loading of divalent WO42− from the solution, because the fraction of two adjacent positively-charged sites on the IRA900 resin was higher and separate from the coexisting VO43−. The adsorbed W could then be eluted with 1 M NaCl + 0.5 M NaOH. The final concentrated W solution had 8.4 g/L of W with 98% purity. The application of this process in industry is expected to have an important impact on the recovery of W from secondary sources of these metals.

  12. Technical note: Efficiency of total demineralization and ion-exchange column for DNA extraction from bone. (United States)

    Seo, Seung Bum; Zhang, Aihua; Kim, Hye Yeon; Yi, Jin A; Lee, Hye Young; Shin, Dong Hoon; Lee, Soong Deok


    We investigated whether a combination of recently introduced methods, total demineralization and ion-exchange columns, would increase DNA recovery from old bone. Ten bone samples taken after a burial period of approximately 60 years were used in this study. Bone powder was digested using total or incomplete demineralization. DNA was extracted by the standard organic method. The DNA extract was purified with ion-exchange columns or QIAquick spin columns. The efficiency of different DNA extraction methods was compared in terms of DNA concentration, inhibitors generated by real-time PCR, and conventional STR typing results. The mean DNA concentration using the total demineralization method is approximately 3 times higher than that using the incomplete demineralization method. For DNA purification, the method using QIAquick spin columns appeared to yield approximately double the DNA than the method using ion-exchange columns. Furthermore, 2 out of 10 samples showed higher levels of inhibition with C(T) values of IPC > or =30 cycles when using only ion-exchange columns. In STR results, total demineralization yielded more locus profiles by 4.2 loci than incomplete demineralization, and QIAquick spin columns also yielded more locus profiles by 3.5 loci than ion-exchange columns. Total demineralization of bone powder significantly increased DNA yield and improved STR typing results. However, the use of ion-exchange columns was not efficient when compared with the method using QIAquick spin columns. It is suggested that the combination of total demineralization and QIAquick spin columns lead to greatly improved STR typing results.

  13. Gold Loading on Ion Exchange Resins in Non-Ammoniacal Resin-Solution Systems


    Abrar Muslim


    The loading of gold using strong base anion exchange resin in non-ammoniac resin-solution (NARS) systems has been studied. The loading of gold onto ion exchange resins is affected by polythionate concentration, and trithionate can be used as the baseline in the system. The results also show that resin capacity on gold loading increases due to the increase in the equilibrium thiosulfate concentration in the NARS system. Gold loading performances show the need of optimization the equilibrium co...

  14. Modeling of salt and pH gradient elution in ion-exchange chromatography. (United States)

    Schmidt, Michael; Hafner, Mathias; Frech, Christian


    The separation of proteins by internally and externally generated pH gradients in chromatofocusing on ion-exchange columns is a well-established analytical method with a large number of applications. In this work, a stoichiometric displacement model was used to describe the retention behavior of lysozyme on SP Sepharose FF and a monoclonal antibody on Fractogel SO3 (S) in linear salt and pH gradient elution. The pH dependence of the binding charge B in the linear gradient elution model is introduced using a protein net charge model, while the pH dependence of the equilibrium constant is based on a thermodynamic approach. The model parameter and pH dependences are calculated from linear salt gradient elutions at different pH values as well as from linear pH gradient elutions at different fixed salt concentrations. The application of the model for the well-characterized protein lysozyme resulted in almost identical model parameters based on either linear salt or pH gradient elution data. For the antibody, only the approach based on linear pH gradients is feasible because of the limited pH range useful for salt gradient elution. The application of the model for the separation of an acid variant of the antibody from the major monomeric form is discussed.

  15. Disease-associated changes in the expression of ion channels, ion receptors, ion exchangers and Ca(2+)-handling proteins in heart hypertrophy. (United States)

    Zwadlo, Carolin; Borlak, Jürgen


    The molecular pathology of cardiac hypertrophy is multifactorial with transcript regulation of ion channels, ion exchangers and Ca(2+)-handling proteins being speculative. We therefore investigated disease-associated changes in gene expression of various ion channels and their receptors as well as ion exchangers, cytoskeletal proteins and Ca(2+)-handling proteins in normotensive and spontaneously hypertensive (SHR) rats. We also compared experimental findings with results from hypertrophic human hearts, previously published (Borlak, J., and Thum, T., 2003. Hallmarks of ion channel gene expression in end-stage heart failure. FASEB J. 17, 1592-1608). We observed significant (P ion exchangers (Atp1A1, NCX-1, SERCA2a), ion channels (L-type Ca(2+)-channel, K(ir)3.4, Na(v)1.5) and RyR-2 in hypertrophic hearts, while gene expression was repressed in diseased human hearts. Further, the genes coding for calreticulin and calmodulin, PMCA 1 and 4 as well as alpha-skeletal actin were significantly (P diseased human and rat hearts. Our study enabled an identification of disease-associated candidate genes. Their regulation is likely to be the result of an imbalance between pressure load/stretch force and vascular tonus and the observed changes may provide a rational for the rhythm disturbances observed in patients with cardiac hypertrophy.

  16. Relation between stabilization energy, crystal field coefficient and themagnetic exchange interaction for Tb3+ ion

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiangmu; MA Wenjuan; CUI Shuwen; WANG Lihua


    Based on a single ion model, Hamiltonian of the simplest form about magnetocrystalline anisotropy for Tb3+ ion was solved by using the numerical method. The relation between the stabilization energy, crystal field coefficient B20 and the magnetic exchange interaction was studied as temperature approaches to 0K. The results show that the stabilization energy contributed by Tb3+ is linear with crystal field coefficient B20 approximately, but it is insensitive to the change of magnetic exchange interaction for the strong magnetic substancessuch as TbCo5, Tb2Co17 and Tb2Fe14B compounds.

  17. Processing of indium (III) solutions via ion exchange with Lewatit K-2621 resin

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Diaz-Pavon, A.; Cerpa, A.; Alguacil, F. J.


    The processing of indium(III)-hydrochloric acid solutions by the cationic ion exchange Lewatit K-2621 resin has been investigated. The influence of several variables such as the hydrochloric acid and metal concentrations in the aqueous solution and the variation of the amount of resin added has been studied. Moreover, a kinetic study performed in the uptake of indium(III) by Lewatit K-2621, shows that either the film-diffusion and the particle-diffusion models fit the ion exchange process onto the resin, depending upon the initial metal concentration in the aqueous solution. The loaded resin could be eluted by HCl solutions at 20 degree centigrade. (Author)

  18. Lability of heavy metal species in aquatic humic substances characterized by ion exchange with cellulose phosphate. (United States)

    Rocha, J C; Toscano, I A; Burba, P


    Labile metal species in aquatic humic substances (HSs) were characterized by ion exchange on cellulose phosphate (CellPhos) by applying an optimized batch procedure. The HSs investigated were pre-extracted from humic-rich waters by ultrafiltration and a resin XAD 8 procedure. The HS-metal species studied were formed by complexation with Cd(II), Ni(II), Cu(II), Mn(II) and Pb(II) as a function of time and the ratio ions to HSs. The kinetics and reaction order of this exchange process were studied. At the beginning ( Pb > Mn > Ni > Cd. The required metal determinations were carried out by atomic absorption spectrometry.

  19. Features of the sorption of phenylalanine by profiled ion-exchange membranes (United States)

    Vasil'eva, V. I.; Goleva, E. A.; Selemenev, V. F.


    Features of the equilibrium sorption of phenylalanine from neutral media by profiled ion-exchange membranes in a wide range of concentrations is studied under static conditions. The mechanism of phenylalanine sorption by ion-exchange membranes with profiled and smooth surfaces is discussed. It is shown that phenylalanine sorption is accompanied by the formation of spatial associative structures of the aminoacid in an external equilibrium solution, and in a solution of the membrane's pore spaces or on its surface. The increased sorption capacity of the profiled membranes is explained by features of the microstructure of their surface and volume.

  20. Nanofiltration: ion exchange system for effective surfactant removal from water solutions

    Directory of Open Access Journals (Sweden)

    I. Kowalska


    Full Text Available A system combining nanofiltration and ion exchange for highly effective separation of anionic surfactant from water solutions was proposed. The subjects of the study were nanofiltration polyethersulfone membranes and ion-exchange resins differing in type and structure. The quality of the treated solution was affected by numerous parameters, such as quality of the feed solution, membrane cut-off, resin type, dose and the solution contact time with the resin. A properly designed purification system made it possible to reduce the concentration of anionic surfactant below 1 mg L-1 from feed solutions containing surfactant in concentrations above the CMC value.

  1. Patchiness of ion-exchanged mica revealed by DNA binding dynamics at short length scales (United States)

    Billingsley, D. J.; Lee, A. J.; Johansson, N. A. B.; Walton, A.; Stanger, L.; Crampton, N.; Bonass, W. A.; Thomson, N. H.


    The binding of double-stranded (ds) DNA to mica can be controlled through ion-exchanging the mica with divalent cations. Measurements of the end-to-end distance of linear DNA molecules discriminate whether the binding mechanism occurs through 2D surface equilibration or kinetic trapping. A range of linear dsDNA fragments have been used to investigate length dependences of binding. Mica, ion-exchanged with Ni(II) usually gives rise to kinetically trapped DNA molecules, however, short linear fragments (ion-exchanged mica is heterogeneous, and contains patches or domains, separating different ionic species. These results correlate with imaging of dsDNA under aqueous buffer on Ni(II)-mica and indicate that binding domains are of the order of 100 nm in diameter. Shorter DNA fragments behave intermediate to the two extreme cases of 2D equilibration and kinetic trapping. Increasing the incubation time of Ni(II) on mica, from minutes to hours, brings the conformations of the shorter DNA fragments closer to the theoretical value for kinetic trapping, indicating that long timescale kinetics play a role in ion-exchange. X-ray photoelectron spectroscopy (XPS) was used to confirm that the relative abundance of Ni(II) ions on the mica surface increases with time. These findings can be used to enhance spatial control of binding of DNA to inorganic surfaces with a view to patterning high densities arrays.

  2. General Top-Down Ion Exchange Process for the Growth of Epitaxial Chalcogenide Thin Films and Devices

    KAUST Repository

    Xia, Chuan


    We demonstrate a versatile top-down ion exchange process, done at ambient temperature, to form epitaxial chalcogenide films and devices, with nanometer scale thickness control. To demonstrate the versatility of our process we have synthesized (1) epitaxial chalcogenide metallic and semiconducting films and (2) free-standing chalcogenide films and (3) completed in situ formation of atomically sharp heterojunctions by selective ion exchange. Epitaxial NiCo2S4 thin films prepared by our process show 115 times higher mobility than NiCo2S4 pellets (23 vs 0.2 cm(2) V-1 s(-1)) prepared by previous reports. By controlling the ion exchange process time, we made free-standing epitaxial films of NiCo2S4 and transferred them onto different substrates. We also demonstrate in situ formation of atomically sharp, lateral Schottky diodes based on NiCo2O4/NiCo2S4 heterojunction, using a single ion exchange step. Additionally, we show that our approach can be easily extended to other chalcogenide semiconductors. Specifically, we used our process to prepare Cu1.8S thin films with mobility that matches single crystal Cu1.8S (25 cm(2) V-1 s(-1)), which is ca. 28 times higher than the previously reported Cu1.8S thin film mobility (0.58 cm(2) V-1 s(-1)), thus demonstrating the universal nature of our process. This is the first report in which chalcogenide thin films retain the epitaxial nature of the precursor oxide films, an approach that will be useful in many applications.

  3. Nuclear quantum effects in water exchange around lithium and fluoride ions

    CERN Document Server

    Wilkins, David M; Dang, Liem X


    We employ classical and ring polymer molecular dynamics simulations to study the effect of nuclear quantum fluctuations on the structure and the water exchange dynamics of aqueous solutions of lithium and fluoride ions. While we obtain reasonably good agreement with experimental data for solutions of lithium by augmenting the Coulombic interactions between the ion and the water molecules with a standard Lennard-Jones ion-oxygen potential, the same is not true for solutions of fluoride, for which we find that a potential with a softer repulsive wall gives much better agreement. A small degree of destabilization of the first hydration shell is found in quantum simulations of both ions when compared with classical simulations, with the shell becoming less sharply defined and the mean residence time of the water molecules in the shell decreasing. In line with these modest differences, we find that the mechanisms of the exchange processes are unaffected by quantization, so a classical description of these reaction...

  4. Effects of swift argon-ion irradiation on the proton-exchanged LiNbO3 crystal (United States)

    Huang, Qing; Liu, Peng; Liu, Tao; Guo, Sha-Sha; Wang, Xue-Lin


    A proton-exchanged LiNbO3 crystal was subjected to 70-MeV argon-ion irradiation. The lattice damage was investigated by the Rutherford backscattering and channeling technique. It was found that the lattice disorder induced by the proton exchange process was partially recovered and the proton-exchanged layer was broadened. It indicated that the lithium ions underneath the initial proton-exchanged layer migrated to the surface during the swift argon-ion irradiation and supplemented the lack of lithium ions in the initial proton-exchanged layer. This effect was ascribed to the great electronic energy deposition and relaxation. The swift argon-ion irradiation induced an increase in extraordinary refractive index and formed another waveguide structure beneath the proton-exchanged waveguide.

  5. Effects of swift argon-ion irradiation on the proton-exchanged LiNbO3 crystal

    Institute of Scientific and Technical Information of China (English)

    Huang Qing; Liu Peng; Liu Tao; Guo Sha-Sha; Wang Xue-Lin


    A proton-exchanged LiNbO3 crystal was subjected to 70-MeV argon-ion irradiation.The lattice damage was investigated by the Rutherford backscattering and channeling technique.It was found that the lattice disorder induced by the proton exchange process was partially recovered and the proton-exchanged layer was broadened.It indicated that the lithium ions underneath the initial proton-exchanged layer migrated to the surface during the swift argon-ion irradiation and supplemented the lack of lithium ions in the initial proton-exchanged layer.This effect was ascribed to the great electronic energy deposition and relaxation.The swift argon-ion irradiation induced an increase in extraordinary refractive index and formed another waveguide structure beneath the proton-exchanged waveguide.

  6. Modified DIX model for ion-exchange equilibrium of L-phenylalanine on a strong cation-exchange resin☆

    Institute of Scientific and Technical Information of China (English)

    Jinglan Wu; Pengfei Jiao; Wei Zhuang; Jingwei Zhou; Hanjie Ying


    L-phenylalanine, one of the nine essential amino acids for the human body, is extensively used as an ingredient in food, pharmaceutical and nutrition industries. A suitable equilibrium model is required for purification of L-phenylalanine based on ion-exchange chromatography. In this work, the equilibrium uptake of L-phenylalanine on a strong acid-cation exchanger SH11 was investigated experimental y and theoretical y. A modified Donnan ion-exchange (DIX) model, which takes the activity into account, was established to predict the uptake of L-phenyl-alanine at various solution pH values. The model parameters including selectivity and mean activity coefficient in the resin phase are presented. The modified DIX model is in good agreement with the experimental data. The optimum operating pH value of 2.0, with the highest L-phenylalanine uptake on the resin, is predicted by the model. This basic information combined with the general mass transfer model wil lay the foundation for the prediction of dynamic behavior of fixed bed separation process.

  7. Improved durability of proton exchange membrane fuel cells by introducing Sn (IV) oxide into electrodes using an ion exchange method (United States)

    Poulsen, M. G.; Larsen, M. J.; Andersen, S. M.


    Electrodes of Proton Exchange Membrane Fuel Cells (PEMFCs), consisting of catalyst-coated gas diffusion layers, were subjected to an optimized ion exchange procedure, in which tin (IV) oxide (SnO2) nanoparticles were introduced into them. Both methanol and sulfuric acid were tested as ion exchange solvents. SnO2 has previously been shown to exhibit radical scavenging abilities towards radicals inside the electrocatalyst layers. Its presence inside the electrodes was confirmed using X-ray photoelectron spectroscopy and X-ray fluorescence. After exposure to an accelerated stress test in a three-electrode setup, the electrodes containing SnO2 were found to have retained approximately 73.0% of their original Pt, while only 53.2% was retained in electrodes treated identically, but without Sn. Similarly, the SnO2-treated electrodes also experienced a smaller loss in electrochemical surface area in comparison to before the accelerated stress test. A membrane electrode assembly (MEA) constructed with a SnO2-containing anode was evaluated over 500 h. The results showed remarkably reduced OCV decay rate and end of test hydrogen crossover compared to the control MEA, indicating that SnO2 aids in impeding membrane thinning and pinhole formation. The results point toward a positive effect of SnO2 on fuel cell durability, by reducing the degradation of the membrane as well as of the ionomer in the electrocatalyst layer.

  8. Effect of diffusion potential, osmosis and ion-exchange on transdermal drug delivery: theory and experiments. (United States)

    Hirvonen, J; Murtomäki, L; Kontturi, K


    Equations expressing the effect of the diffusion potential on the trace ion transfer across a porous charged membrane have been derived. These equations have been tested with experiments with human cadaver skin. The transfer of sotalol and salicylate was measured varying the salt (NaCl) concentration in the donor and receiver compartments. It appears that osmotic pressure and ion-exchange make a significant contribution to the flux enhancement by the diffusion potential.

  9. Acid Extraction - Ion Exchange Recovery of Cinchona Alkaloids Process and Plant Development (United States)


    farther and farther into the almost impenetrable rain forests of the Andes in search of drug- bearing bark. b. Labor and Transportation. In these...a certain percentage of the ion exchanger still bearing its hydrogen ion charge. As long as this situation exists, a certain amount of COp will...extraction medium. Hence, the contact time need be no greater than that re- quired to soften and disintegrate the gummy contents of the cell, plus


    Institute of Scientific and Technical Information of China (English)

    DOUHuiyuan; WANGChangshou; 等


    The potentiometric behavior of the chelating ion exchange resin D751 containing iminodiacetic acid groups has been studied at 25℃ by batch titration with alkali and acid in water and in ethanol-water mixture solvent.The titrtion curves,the amount of chemically bound counter-ions and invasive electrolytes in the resin phase,and the solvent contents the resin have been investigated.

  11. Nitroguanidine Wastewater Pollution Control Technology: Phase III. Ion Exchange and Carbon Adsorption Treatment (United States)


    SD are synthetic cross-linked resins provided as moist spherical beads nominally of 50 percent water content. The clinoptilolite was supplied presized...Na+ i3 provided by a resin (either naturally occurring or synthetic ). Usually, the resin is prepared in a fixed-bed column, and hard water ion is...these :.ons as well as NQ. I/’ I . , I * MATERIALS AND METHODS RESINS AND CARBONS Three ion-exchange materials were studied: clinoptilolite , an

  12. Denitration of Rocky Flats Ion-Exchange Resins: Recommendation of Denitration Processes, October 19, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Jacob Espinoza; Mary Barr; Wayne Smith


    Resin denitration via anion-exchange is an implementable process that can effectively mitigate the hazards associated with stored resins in which the bulk of the nitrate consists of an "exchangeable nitrate" ionically bound to the cationic sites of the anion-exchange resins. Salicylate has been selected as the exchange anion of choice because of its superior selectivity for the Rocky Flats resins and its unique potential for comprehensive recovery and recycle. This report outlines a single recommended resin denigration procedure that is reasonably independent of the resin composition and the current stored form. This procedure is not optimized but rather seeks to `over-treat' the resins so that a single procedure works for the variety of stored resins. The recommended treatment with sodium salicylate reduces resins by 95-99+% the measured exothermic behavior of the ion-exchange.

  13. Effect of formaldehyde on Cu(II) removal from synthetic complexed solutions by ion exchange. (United States)

    Juang, Ruey-Shin; Lin, Su-Hsia; Kao, Hsiang-Chien; Theng, Ming-Huei


    The effect of formaldehyde (HCHO) on the ion exchange of Cu(II) from an equimolar EDTA (ethylenediaminetetraacetic acid, H(4)L) solution with a strong-base Amberlite IRA-400 resin was studied. Experiments were conducted as a function of the initial concentration of Cu(II) (0.5-10 mM), solution pH (1.0-6.0), HCHO concentration (0-6 vol%), and temperature (15-35 degrees C). It was shown that the amount of exchange of Cu(II), which exists in the form of complexed anions CuL(2-), increased with increasing solution pH and reached a plateau at an equilibrium pH (pH(e)) of 3.5. However, the amount of exchange decreased with increasing HCHO concentration up to 3 vol% but then slightly decreased with a further increase in HCHO concentration. Such effect of added HCHO was determined by the following two factors: the competitive exchange of HCOO(-) anions and the enhanced exchange of Cu(I) in the form of complexed anions CuL(3-). The exchange isotherm obtained at a fixed pH(e) could be well described by the Langmuir equation. The isosteric enthalpy change for the present ion exchange process was also evaluated and discussed.

  14. Ion exchanger in the brain: Quantitative analysis of perineuronally fixed anionic binding sites suggests diffusion barriers with ion sorting properties (United States)

    Morawski, Markus; Reinert, Tilo; Meyer-Klaucke, Wolfram; Wagner, Friedrich E.; Tröger, Wolfgang; Reinert, Anja; Jäger, Carsten; Brückner, Gert; Arendt, Thomas


    Perineuronal nets (PNs) are a specialized form of brain extracellular matrix, consisting of negatively charged glycosaminoglycans, glycoproteins and proteoglycans in the direct microenvironment of neurons. Still, locally immobilized charges in the tissue have not been accessible so far to direct observations and quantifications. Here, we present a new approach to visualize and quantify fixed charge-densities on brain slices using a focused proton-beam microprobe in combination with ionic metallic probes. For the first time, we can provide quantitative data on the distribution and net amount of pericellularly fixed charge-densities, which, determined at 0.4-0.5 M, is much higher than previously assumed. PNs, thus, represent an immobilized ion exchanger with ion sorting properties high enough to partition mobile ions in accord with Donnan-equilibrium. We propose that fixed charge-densities in the brain are involved in regulating ion mobility, the volume fraction of extracellular space and the viscosity of matrix components.

  15. Charge-exchange Induced Modulation of the Heliosheath Ion Distribution Downstream of the Termination Shock (United States)

    Fahr, H. J.; Fichtner, H.; Scherer, K.


    We consider the evolution of the solar wind ion distribution function alongthe plasma flow downstream from the termination shock induced by chargeexchange processes with cold interstellar H-atoms. We start from a kineticphase space transport equation valid in the bulk frame of the plasma flowthat takes into account convective changes, cooling processes, energydiffusion and ion injection, and describes solar wind and pick-up ionsas a co-moving, isotropic, joint ion population. From this kinetic transportequation one can ascend to an equation for the pressure moment of the iondistribution function, a so-called pressure transport equation, describingthe evolution of the ion pressure in the comoving rest frame. Assuming thatthe local ion distribution can be represented by an adequate kappa functionwith a kappa parameter that varies with the streamline coordinate, weobtain an ordinary differential equation for kappa as function of thestreamline coordinate s. With this result then we gain the heliosheath iondistribution function downstream of the termination shock. The latter thencan be used to predict the Voyager-2 measured moments of the distributionfunction like ion density and ion temperature, and it can also be used topredict spectral fluxes of ENA`s originating from these ions and registeredby IBEX-Hi and IBEX-Lo.We especially analyse the solar wind ion temperature decreasemeasured by Voyager-2 between the years 2008 to 2011 and try to explain itas a charge-exchange induced cooling of the ion distribution function duringthe associated ion convection period.

  16. Purification of a recombinant baculovirus of Autographa californica M nucleopolyhedrovirus by ion exchange membrane chromatography. (United States)

    Grein, Tanja A; Michalsky, Ronald; Vega López, Maria; Czermak, Peter


    Significant progress in the application of viral vectors for gene delivery into mammalian cells and the use of viruses as biopesticides requires downstream processing that can satisfy application-specific demands on performance. In the present work the stability and ion exchange membrane chromatography of a recombinant of Autographa californica M nucleopolyhedrovirus is studied. To adjust the degree of purification the effect of ionic conductivity or pH on the viral infectivity was assessed (0.77-78.00mS/cm, pH 3-8). Infectivity decreased rapidly by several orders of magnitude at below 5mS/cm (i.e., 0.49MPa osmotic pressure change) or at below pH 5.5 (rationalized with particle aggregation). The virus was concentrated and purified via adsorption (0.2-1.1×10(16)pfu/m(3) chromatographic bed volume, 0.6-1.1×10(12)pfu/m(2) membrane area facing the incident fluid flow) and elution at pH 6.1 and 6.35mS/cm from three strong anion exchange membranes. Virus recovery and concentration in accord with the volume reduction were obtained using a polyether sulfone-based membrane with quaternary ammonium ligands. The level of host cell protein (down to below the detection limit) and suspended DNA (below 93pg DNA per 10(6)pfu) are reported for each membrane employed, for the purpose of comparability, under equal adsorption or elution conditions respectively.

  17. Interaction between the exchanged Mn2+ and Yb3+ ions confined in zeolite-Y and their luminescence behaviours (United States)

    Ye, Shi; Sun, Jiayi; Yi, Xiong; Wang, Yonggang; Zhang, Qinyuan


    Luminescent zeolites exchanged with two distinct and interacted emissive ions are vital but less-studied for the potential applications in white light emitting diodes, solar cells, optical codes, biomedicine and so on. Typical transition metal ion Mn2+ and lanthanide ion Yb3+ are adopted as a case study via their characteristic transitions and the interaction between them. The option is considered with that the former with d-d transition has a large gap between the first excited state 4T1 and the ground state 6A1 (normally >17,000 cm-1) while the latter with f-f transition has no metastable excited state above 10,000 cm-1, which requires the vicinity of these two ions for energy transfer. The results of various characterizations, including BET measurement, photoluminescence spectroscopy, solid-state NMR, and X-ray absorption spectroscopy, etc., show that Yb3+ would preferably enter into the zeolite-Y pores and introduction of Mn2+ would cause aggregation of each other. Herein, cation-cation repulsion may play a significant role for the high valence of Mn2+ and Yb3+ when exchanging the original cations with +1 valence. Energy transfer phenomena between Mn2+ and Yb3+ occur only at elevated contents in the confined pores of zeolite. The research would benefit the design of zeolite composite opto-functional materials.

  18. The ion exchange properties and equilibrium constants of Li+, Na+ and K+ on zirconium phosphate highly dispersed on a cellulose acetate fibers surface

    Directory of Open Access Journals (Sweden)

    Borgo Claudemir Adriano


    Full Text Available Highly dispersed zirconium phosphate was prepared by reacting celullose acetate/ZrO2 (ZrO2 = 11 wt%, 1.0 mmol g-1 of zirconium atom per gram of the material with phosphoric acid. High power decoupling magic angle spinning (HPDEC-MAS 31P NMR and X-ray photoelectron spectroscopy data indicated that HPO4(2- is the species present on the membrane surface. The specific concentration of acidic centers, determined by ammonia gas adsorption, is 0.60 mmol g-1. The ion exchange capacities for Li+, Na+ and K+ ions were determined from ion exchange isotherms at 298 K and showed the following values (in mmol g-1: Li+= 0.05, Na+= 0.38 and K+= 0.57. Due to the strong cooperative effect, the H+/Na+ and H+/K+ ion exchange is of non ideal nature. These ion exchange equilibria were treated with the use of models of fixed tridentate centers, which consider the surface of the sorbent as polyfunctional sorption centers. Both the observed ion exchange capacities with respect to the alkaline metal ions and the equilibrium constants are discussed by taking into consideration the sequence of the ionic hydration radii for Li+, Na+ and K+. The matrix affinity for the ions decreases with increasing the cations hydration radii from K+ to Li+. The high values of the separation factors S Na+/Li+ and S K+/Li+ (up to several hundreds support the application of this material for the quantitative separation of Na+ and K+ from Li+ from a mixture containing these three ions.

  19. Instrumentation: Ion Chromatography. (United States)

    Fritz, James S.


    Discusses the importance of ion chromatography in separating and measuring anions. The principles of ion exchange are presented, along with some applications of ion chromatography in industry. Ion chromatography systems are described, as well as ion pair and ion exclusion chromatography, column packings, detectors, and programming. (TW)

  20. Energy efficient reconcentration of diluted human urine using ion exchange membranes in bioelectrochemical systems. (United States)

    Tice, Ryan C; Kim, Younggy


    Nutrients can be recovered from source separated human urine; however, nutrient reconcentration (i.e., volume reduction of collected urine) requires energy-intensive treatment processes, making it practically difficult to utilize human urine. In this study, energy-efficient nutrient reconcentration was demonstrated using ion exchange membranes (IEMs) in a microbial electrolysis cell (MEC) where substrate oxidation at the MEC anode provides energy for the separation of nutrient ions (e.g., NH4(+), HPO4(2-)). The rate of nutrient separation was magnified with increasing number of IEM pairs and electric voltage application (Eap). Ammonia and phosphate were reconcentrated from diluted human urine by a factor of up to 4.5 and 3.0, respectively (Eap = 1.2 V; 3-IEM pairs). The concentrating factor increased with increasing degrees of volume reduction, but it remained stationary when the volume ratio between the diluate (urine solution that is diluted in the IEM stack) and concentrate (urine solution that is reconcentrated) was 6 or greater. The energy requirement normalized by the mass of nutrient reconcentrated was 6.48 MJ/kg-N (1.80 kWh/kg-N) and 117.6 MJ/kg-P (32.7 kWh/kg-P). In addition to nutrient separation, the examined MEC reactor with three IEM pairs showed 54% removal of COD (chemical oxygen demand) in 47-hr batch operation. The high sulfate concentration in human urine resulted in substantial growth of both of acetate-oxidizing and H2-oxidizing sulfate reducing bacteria, greatly diminishing the energy recovery and Coulombic efficiency. However, the high microbial activity of sulfate reducing bacteria hardly affected the rate of nutrient reconcentration. With the capability to reconcentrate nutrients at a minimal energy consumption and simultaneous COD removal, the examined bioelectrochemical treatment method with an IEM application has a potential for practical nutrient recovery and sustainable treatment of source-separated human urine.

  1. Commercial Ion Exchange Resin Vitrification in Borosilicate Glass

    Energy Technology Data Exchange (ETDEWEB)

    Cicero-Herman, C.A.; Workman, P. [Westinghouse Savannah River Co., Aiken, SC (United States); Poole, K.; Erich, D.; Harden, J. [Clemson Environmental Technologies Laboratory, Anderson, SC (United States)


    Bench-scale studies were performed to determine the feasibility of vitrification treatment of six resins representative of those used in the commercial nuclear industry. Each resin was successfully immobilized using the same proprietary borosilicate glass formulation. Waste loadings varied from 38 to 70 g of resin/100 g of glass produced depending on the particular resin, with volume reductions of 28 percent to 68 percent. The bench-scale results were used to perform a melter demonstration with one of the resins at the Clemson Environmental Technologies Laboratory (CETL). The resin used was a weakly acidic meth acrylic cation exchange resin. The vitrification process utilized represented a approximately 64 percent volume reduction. Glass characterization, radionuclide retention, offgas analyses, and system compatibility results will be discussed in this paper.

  2. Development of laser ion source for heavy ion applications

    Energy Technology Data Exchange (ETDEWEB)

    Shibuya, Shinji, E-mail: [Accelerator Engineering Corporation, 3-8-5 Konakadai, Inage-ku, Chiba 263-0043 (Japan); Hattori, Toshiyuki, E-mail: [Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan); Hayashizaki, Noriyosu, E-mail: [Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan); Kashiwagi, Hirotsugu, E-mail: [Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki-shi, Gunma 370-1292 (Japan); Maruyama, Toshiyuki, E-mail: [Toyama Co., Ltd., 4-13-16 Hibarigaoka, Zama-shi, Kanagawa 252-0003 (Japan); Mochizuki, Tetsuro, E-mail: [Toyama Co., Ltd., 4-13-16 Hibarigaoka, Zama-shi, Kanagawa 252-0003 (Japan); Momota, Sadao, E-mail: [Kochi University of Technology, 185 Tosa-yamada-cyo, Kami-shi, Kochi 782-8502 (Japan); Nakagawa, Jun, E-mail: [Toyama Co., Ltd., 4-13-16 Hibarigaoka, Zama-shi, Kanagawa 252-0003 (Japan); Takeuchi, Takeshi, E-mail: [Accelerator Engineering Corporation, 3-8-5 Konakadai, Inage-ku, Chiba 263-0043 (Japan)


    We have been developing a high-performance laser ion source (LIS) for practical applications since 2009. Ideally, the LIS should generate a carbon beam with a peak current of 20 mA and a pulse duration of over 1 {mu}s. We selected a Nd:YAG laser with a Gaussian-coupled resonator as the laser source based on our experience of generating high-charge-state ion beams. This laser can produce fundamental pulses with a power of 650 mJ and durations of about 6 ns. The graphite target used is 10 cm high and 10 cm in diameter, as it can be irradiated with up to 10{sup 5} laser shots. The maximum extraction voltage was designed to be 50 kV. We have already finished designing the LIS and we commenced fabrication. We intend to measure the source performance by performing plasma and beam tests up to the end of March 2011.

  3. Beam propagation in Cu +-Na + ion exchange channel waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Villegas Vicencio, L. J.; Khomenko, A. V.; Salazar, D.; Marquez, H. [Centro de Investigacion Cientifica y de Educacion Superior de Ensenada, Baja California (Mexico); Porte, H. [Universite de Franche-Comte, UFR des Sciences et Techniques, Besancon, Cedex (France)


    We employ the fast Fourier transform beam propagation method to simulate the propagation of light in graded index channel waveguides, these have been obtained by solid state diffusion of copper ions in soda-lime glass substrates. Longitudinal propagation has been simulated, the input light beam has a gaussian profile. Two cases have been analyzed, in the first, the Gaussian beam is collinear center to center with respect to waveguide; in the second, a small lateral offset and angular tilt have been introduced. Modal beating and bending effects have been founded. We have proven the validity of our numerical results in detailed comparison with experimental data. [Spanish] Se ha empleado el metodo de propagacion de haces por la transformada rapida de Fourier para simular la propagacion de la luz en guias de onda de indice de gradiente. Estas han sido fabricadas por difusion de iones de cobre en estado solido en substratos de vidrios sodicos-calcicos. Se han simulado dos casos, el primero, el perfil de luz de entrada, que es gaussiano, es colineal centro a centro respecto al centro de la guia de ondas: el segundo, se ha dado un pequeno corrimiento lateral y una inclinacion angular. Como consecuencia de los casos anteriores se ha observado efectos de batimiento modal. Los resultados de la simulacion se han validado con resultados experimentales.


    Institute of Scientific and Technical Information of China (English)

    ZhuXingbao; YuJinchun; 等


    There exists a universal phenomena that sodium ions are leaked from the strong basic anion exdchanger in operation,which has been puzzling the researchers working in the field of water treatment for years.It is well known that the leakage of sodium ions will seriously affect the pruity of effluent.On the basis of lots of laboratory and industrial experiments,the mechanism of the sodium ions leaked from an anion exchanger has been preliminarily made out and some new chemical reaction equations as well as some improving measures have been put forward in this article.

  5. Synthesis and Characterization of Templated Ion Exchange Resins for the Selective Complexation of Actinide Ions

    Energy Technology Data Exchange (ETDEWEB)

    Uy, O. Manual


    The purpose of this research is to develop a polymeric extractant for the selective complexation of uranyl ions (and subsequently other actinyl and actinide ions) from aqueous solutions (lakes, streams, waste tanks and even body fluids). Chemical insights into what makes a good complexation site will be used to synthesize reagents tailor-made for the complexation of uranyl and other actinide ions. These insights, derived from studies of molecular recognition include ion coordination number and geometry, ionic size and ionic shape, as well as ion to ligand thermodynamic affinity. Selectivity for a specific actinide ion will be obtained by providing the polymers with cavities lined with complexing ligands so arranged as to match the charge, coordination number, coordination geometry, and size of the actinide metal ion. These cavity-containing polymers will be produced by using a specific ion (or surrogate) as a template around which monomeric complexing ligands will be polymerized. The complexing ligands will be ones containing functional groups known to form stable complexes with a specific ion and less stable complexes with other cations. Prior investigator's approaches for making templated resins for metal ions have had marginal success. We have extended and amended these methodologies in our work with Pb(II) and uranyl ion, by changing the order of the steps, by the inclusion of sonication, by using higher complex loading, and the selection of functional groups with better complexation constants. This has resulted in significant improvements to selectivity. The unusual shape of the uranyl ion suggests that this approach will result in even greater selectivities than already observed for Pb(II). Preliminary data obtained for uranyl templated polymers shows unprecedented selectivity and has resulted in the first ion selective electrode for uranyl ion.

  6. Release of proteins via ion exchange from albumin-heparin microspheres

    NARCIS (Netherlands)

    Kwon, Glen S.; Bae, You Han; Cremers, Harry; Feijen, Jan; Kim, Sung Wan


    Albumin-heparin and albumin microspheres were prepared as ion exchange gels for the controlled release of positively charged polypeptides and proteins. The adsorption isotherms of chicken egg and human lysozyme, as model proteins, on microspheres were obtained. An adsorption isotherm of chicken egg

  7. Corrosion of steel drums containing cemented ion-exchange resins as intermediate level nuclear waste

    Energy Technology Data Exchange (ETDEWEB)

    Duffó, G.S. [Departamento de Materiales, Comisión Nacional de Energía Atómica, Av. Gral. Paz 1499, 1650 Buenos Aires (Argentina); Universidad Nacional de San Martín, Av. Gral. Paz 1499, 1650 Buenos Aires (Argentina); Consejo Nacional de Investigaciones Científicas y Tecnológicas – CONICET, Av. Gral. Paz 1499, 1650 Buenos Aires (Argentina); Farina, S.B., E-mail: [Departamento de Materiales, Comisión Nacional de Energía Atómica, Av. Gral. Paz 1499, 1650 Buenos Aires (Argentina); Universidad Nacional de San Martín, Av. Gral. Paz 1499, 1650 Buenos Aires (Argentina); Consejo Nacional de Investigaciones Científicas y Tecnológicas – CONICET, Av. Gral. Paz 1499, 1650 Buenos Aires (Argentina); Schulz, F.M. [Consejo Nacional de Investigaciones Científicas y Tecnológicas – CONICET, Av. Gral. Paz 1499, 1650 Buenos Aires (Argentina)


    Highlights: • There are no works related to the corrosion of drums containing radioactive waste. • Chloride induces high corrosion rate and after 1 year it drops abruptly. • Decrease in the corrosion rate is due to the lack of water to sustain the process. • Cementated ion-exchange resins do not pose risks of corrosion of the steel drums. -- Abstract: Exhausted ion-exchange resins used in nuclear reactors are immobilized by cementation before being stored. They are contained in steel drums that may undergo internal corrosion depending on the presence of certain contaminants. The objective of this work is to evaluate the corrosion susceptibility of steel drums in contact with cemented ion-exchange resins with different aggressive species. The corrosion potential and the corrosion rate of the steel, and the electrical resistivity of the matrix were monitored for 900 days. Results show that the cementation of ion-exchange resins seems not to pose special risks regarding the corrosion of the steel drums.

  8. Ion-exchanged glass waveguides with low birefringence for a broad range of waveguide widths. (United States)

    Yliniemi, Sanna; West, Brian R; Honkanen, Seppo


    Optical communications networks require integrated photonic components with negligible polarization dependence, which typically means that the waveguides must feature very low birefringence. Recent studies have shown that waveguides with low birefringence can be obtained, e.g., by use of silica-on-silicon waveguides or buried ion-exchanged glass waveguides. However, many integrated photonic circuits consist of waveguides with varying widths. Therefore low birefringence is consequently required for waveguides having different widths. This is a difficult task for most waveguide fabrication technologies. We present experimental results on waveguide birefringence for buried silver-sodium ion-exchanged glass waveguides. We show that the waveguide birefringence of the order of 10(-6) for waveguide mask opening widths ranging from 2 to 10 microm can be obtained by postprocessing the sample through annealing at an elevated temperature. The measured values are in agreement with the values calculated with our modeling software for ion-exchanged glass waveguides. This unique feature of ion-exchanged waveguides may be of significant importance in a wide variety of integrated photonic circuits requiring polarization-independent operation.

  9. CFD Modeling of Flow and Ion Exchange Kinetics in a Rotating Bed Reactor System

    DEFF Research Database (Denmark)

    Larsson, Hilde Kristina; Schjøtt Andersen, Patrick Alexander; Byström, Emil


    be achieved by making the baffles deeper. Two-phase simulations were performed, which managed to reproduce the deflection of the gas–liquid interface in an unbaffled system. A chemical reaction was implemented in the model, describing the ion-exchange phenomena in the porous material using four different...

  10. Prediction of ion-exchange column breakthrough curves by constant-pattern wave approach. (United States)

    Lee, I-Hsien; Kuan, Yu-Chung; Chern, Jia-Ming


    The release of heavy metals from industrial wastewaters represents one of major threats to environment. Compared with chemical precipitation method, fixed-bed ion-exchange process can effectively remove heavy metals from wastewaters and generate no hazardous sludge. In order to design and operate fixed-bed ion-exchange processes successfully, it is very important to understand the column dynamics. In this study, the column experiments for Cu2+/H+, Zn2+/H+, and Cd2+/H+ systems using Amberlite IR-120 were performed to measure the breakthrough curves under varying operating conditions. The experimental results showed that total cation concentration in the mobile-phase played a key role on the breakthrough curves; a higher feed concentration resulted in an earlier breakthrough. Furthermore, the column dynamics was also predicted by self-sharpening and constant-pattern wave models. The self-sharpening wave model assuming local ion-exchange equilibrium could provide a simple and quick estimation for the breakthrough volume, but the predicted breakthrough curves did not match the experimental data very well. On the contrary, the constant-pattern wave model using a constant driving force model for finite ion-exchange rate provided a better fit to the experimental data. The obtained liquid-phase mass transfer coefficient was correlated to the flow velocity and other operating parameters; the breakthrough curves under varying operating conditions could thus be predicted by the constant-pattern wave model using the correlation.

  11. A hydrogen-oxygen fuel cell using an ion-exchange membrane as an electrolyte

    NARCIS (Netherlands)

    Duin, P.J. van; Kruissink, C.A.


    Using an acidic type of water leached ion exchange membrane, cell current outputs of the order of 100 mA▪cm-2 at 0,6 V cell voltage have been obtained; the removal of produced water largely limits the cell performance. Cells using the alkaline type of membrane exhibit much smaller current densities,

  12. Charge exchange process with low energy multicharged ions: n, l populations

    Energy Technology Data Exchange (ETDEWEB)

    Chetioui, A.; Rozet, J.P.; Vernhet, D.; Wohrer, K.; Bouisset, P.; Touati, A.; Stephan, C.


    Theoretical models for low energy charge exchange collisions of highly charged ions are reviewed in connection with population final states. A simple experimental method is presented which provides the most populated n level, the percentage of p substates and the mean l value. Results are reported for 10 keV/q Al S collisions on H2 and He. (orig.).


    Energy Technology Data Exchange (ETDEWEB)

    Duignan, M; Charles Nash, C; Timothy Punch, T


    A principal role of the DOE Savannah River Site is to safely dispose of a large volume of liquid nuclear waste held in many storage tanks. An in-tank ion exchange unit is being considered for cesium removal to accelerate waste processing. This unit is planned to have a relatively high bed height to diameter ratio (10:1). Complicating the design is the need to cool the ion exchange media; therefore, the ion exchange column will have a central cooling core making the flow path annular. To separate cesium from waste the media being considered is made of resorcinol formaldehyde resin deposited on spherical plastic beads and is a substitute for a previously tested resin made of crystalline silicotitanate. This spherical media not only has an advantage of being mechanically robust, but, unlike its predecessor, it is also reusable, that is, loaded cesium can be removed through elution and regeneration. Resin regeneration leads to more efficient operation and less spent resin waste, but its hydraulic performance in the planned ion exchange column was unknown. Moreover, the recycling process of this spherical resorcinol formaldehyde causes its volume to significantly shrink and swell. To determine the spherical media's hydraulic demand a linearly scaled column was designed and tested. The waste simulant used was prototypic of the wastes' viscosity and density. This paper discusses the hydraulic performance of the media that will be used to assist in the design of a full-scale unit.

  14. Synthesis of Anomeric Methyl Fructofuranosides and Their Separation on an Ion-Exchange Resin (United States)

    Nurminen, Erkki; Poijarvi, Paivi; Koskua, Katja; Hovinen, Jari


    Treatment of d-fructose with methanol in the presence of acid as a catalyst gives a mixture of methyl-[beta]-d-fructopyranoside, methyl-[alpha]-D-fructofuranoside, and methyl-[beta]-d-fructofuranoside, which were separated on an ion exchange column and characterized polarimetrically.

  15. Controlled transdermal delivery of leuprorelin by pulsed iontophoresis and ion-exchange fiber. (United States)

    Malinovskaja, Kristina; Laaksonen, Timo; Hirvonen, Jouni


    Poor transport efficacy and issues related to biological variation are major concerns in the development of novel iontophoretic devices for the transdermal delivery of therapeutic peptides. The objective of this study was to examine the impact of constant and pulsed current on the transport of nonapeptide leuprorelin acetate across porcine epidermis. Also, the potential of drug delivery system combining iontophoresis and ion-exchange fibers as drug matrices for the delivery of the same peptide was tested. The present study demonstrated the benefit of pulsed current (Tn=2.59×10(-4)) over constant current (Tn=1.7×10(-4)) in terms of more efficient transdermal peptide transport. An increase in the delivery of electroosmotic marker by pulsed current was due to the combined effect of more pronounced electroosmotic transport and reduced inhibition of passive transport. We also showed a promising approach using ion-exchange fibers for controlling the release and iontophoretic transdermal delivery of peptides. Positively charged leuprorelin acetate was bound to the ion-exchange groups of cation-exchange fibers until it was gradually released by mobile counter ions in the external solution. Transdermal flux from acrylic acid grafted Smopex®-102 fibers remained higher (Jss=0.71μg/hcm(2)) than from sulfonic acid grafted Smopex®-101 fibers (Jss=0.31μg/hcm(2)) due to better drug release.

  16. Rate-determining steps in fuel cells with ion exchange membranes

    NARCIS (Netherlands)

    Duin, P.J. van; Kruissink, C.A.


    It has been shown by impedance measurements that over a large range of potentials the current at the oxygen electrode of hydrogen-oxygen ion exchange membrane fuel cells is controlled by a charge tra11sfer reaction. The frequency range used covered six decades.

  17. Reactivity of Phenol Allylation Using Phase-Transfer Catalysis in Ion-Exchange Membrane Reactor

    Directory of Open Access Journals (Sweden)

    Ho Shing Wu


    Full Text Available This study investigates the reactivity of phenol allylation using quaternary ammonium salt as a phase-transfer catalyst in three types of membrane reactors. Optimum reactivity and turnover of phenol allylation were obtained using a respond surface methodology. The contact angle, water content, and degree of crosslinkage were measured to understand the microenvironment in the ion exchange membrane.

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

    Energy Technology Data Exchange (ETDEWEB)

    Collins, J.L.; Davidson, D.J.; Chase, C.W.; Egan, B.Z. (Oak Ridge National Lab., TN (United States)); Ensor, D.D.; Bright, R.M.; Glasgow, D.C. (Tennessee Technological Univ., Cookeville, TN (United States))


    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Collins, J.L.; Davidson, D.J.; Chase, C.W.; Egan, B.Z. [Oak Ridge National Lab., TN (United States); Ensor, D.D.; Bright, R.M.; Glasgow, D.C. [Tennessee Technological Univ., Cookeville, TN (United States)


    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.

  20. Separation and characterisation of beta2-microglobulin folding conformers by ion-exchange liquid chromatography and ion-exchange liquid chromatography-mass spectrometry. (United States)

    Bertoletti, Laura; Regazzoni, Luca; Aldini, Giancarlo; Colombo, Raffaella; Abballe, Franco; Caccialanza, Gabriele; De Lorenzi, Ersilia


    In this work we present for the first time the use of ion-exchange liquid chromatography to separate the native form and a partially structured intermediate of the folding of the amyloidogenic protein beta2-microglobulin. Using a strong anion-exchange column that accounts for the differences in charge exposure of the two conformers, a LC-UV method is initially optimised in terms of mobile phase pH, composition and temperature. The preferred mobile phase conditions that afford useful information were found to be 35 mM ammonium formate, pH 7.4 at 25°C. The dynamic equilibrium of the two species is demonstrated upon increasing the concentration of acetonitrile in the protein sample. Then, the chromatographic method is transferred to MS detection and the respective charge state distributions of the separated conformers are identified. The LC-MS results demonstrate that one of the conformers is partially unfolded, compared with the native and more compact species. The correspondence with previous results obtained in free solution by capillary electrophoresis suggest that strong ion exchange LC-MS does not alter beta2-microglobulin conformation and maintains the dynamic equilibrium already observed between the native protein and its folding intermediate.

  1. Compact microwave ion source for industrial applications. (United States)

    Cho, Yong-Sub; Kim, Dae-Il; Kim, Han-Sung; Seol, Kyung-Tae; Kwon, Hyeok-Jung; Hong, In-Seok


    A 2.45 GHz microwave ion source for ion implanters has many good properties for industrial application, such as easy maintenance and long lifetime, and it should be compact for budget and space. But, it has a dc current supply for the solenoid and a rf generator for plasma generation. Usually, they are located on high voltage platform because they are electrically connected with beam extraction power supply. Using permanent magnet solenoid and multi-layer dc break, high voltage deck and high voltage isolation transformer can be eliminated, and the dose rate on targets can be controlled by pulse duty control with semiconductor high voltage switch. Because the beam optics does not change, beam transfer components, such as focusing elements and beam shutter, can be eliminated. It has shown the good performances in budget and space for industrial applications of ion beams.

  2. Ion Exchange Extraction of Boron from Aqueous Fluids by Amberlite IRA 743 Resin

    Institute of Scientific and Technical Information of China (English)

    肖应凯; 廖步勇; 刘卫国; 肖云; SWIHART,GeorgeH.


    The ion exchange characteristics d Amherlite IRA 743 resin for extracting boron from aqueous fluids have been investigated in detail. The results show that AmherHte IRA 743 resin, a boron specific ion exchange resin, can quantitatively extract boron as the B (OH)4- spedes from weakly basle solution. Some exchangeable anions such as CI- and SO42- are present, resulting in an increase in pH value of the loeded solution within the nan, and the boron in natural aqueous fluids with low nH is also extracted by Amberlite IRA 743 resin. However, the voiume of loaded solution must be restricted. The maximum voiume of loaded solution giving quantitative extraction of boron decreases for sample soh.,tiom of lower pH value. Warm HCI solution is more effective than room temperature HCI solution for eluting boron from Amberllte IRA 743 resin.

  3. Removal of Carbon Dioxide from Gas Mixtures Using Ion-Exchanged Silicoaluminophosphates (United States)

    Hernandez-Maldonado, Arturo J (Inventor); Rivera-Ramos, Milton E (Inventor); Arevalo-Hidalgo, Ana G (Inventor)


    Na+-SAPO-34 sorbents were ion-exchanged with several individual metal cations for CO2 absorption at different temperatures (273-348 K) and pressures (<1 atm). In general, the overall adsorption performance of the exchanged materials increased as follows: Ce3+exchanged materials excelled at low-pressure ranges, exhibiting very sharp isotherms slopes at all temperatures. The Sr2+ species were responsible for the surface strong interaction and the cations were occupying exposed sites (SII') in the materials Chabazite cages. All the sorbent materials exhibited higher affinity for CO2 over the other gases tested (i.e., CH4, H2, N2 and O2) due to strong ion-quadrupole interactions. Sr2+-SAPO-34 sorbents are by far the best option for CO2 removal from CH4 mixtures, especially at low concentrations.


    Energy Technology Data Exchange (ETDEWEB)

    Aleman, S.; Hamm, L.; Smith, F.


    fixed ionogenic groups that make up sRF. Recent literature reviews and scoping titration tests strongly indicate that sRF is a polyfunctional cation exchange resin with at least three dominant types of ring groups playing a role in its isotherm behavior over the wide pH range of operations. Also three types of fixed ionogenic acid groups are present: sulfonic (SO{sub 3}H{sup -}) groups; carboxylic (COOH{sup -}) groups, and resorcylic (OH{sup -}) groups. It is this premise that we are working under in the development of a robust isotherm model for sRF over its entire planned pH operating range. The application of prototypic isotherms for modeling ion-exchange column behavior is demonstrated in Section 3 of this report. This preliminary work served to focus the development effort on the use of a mass-action based isotherm. In Section 4 of this report, the foundational material required to develop a robust isotherm model for sRF is provided. The paths taken, and choices made, are given for the reader to better understand our current status with respect to this goal and to highlight our most recent understanding of sRF exchange equilibria. Our ultimate goal is to update the CERMOD code (Aleman and Hamm, 2007) with a robust isotherm model for sRF that spans the entire pH and concentration ranges of planned operations. The isotherm model will then be used in the VERSE-LC code to model an entire ion-exchange cycle.

  5. Radon (222Rn) in ground water of fractured rocks: A diffusion/ion exchange model (United States)

    Wood, W.W.; Kraemer, T.F.; Shapiro, A.


    Ground waters from fractured igneous and high-grade sialic metamorphic rocks frequently have elevated activity of dissolved radon (222Rn). A chemically based model is proposed whereby radium (226Ra) from the decay of uranium (238U) diffuses through the primary porosity of the rock to the water-transmitting fracture where it is sorbed on weathering products. Sorption of 226Ra on the fracture surface maintains an activity gradient in the rock matrix, ensuring a continuous supply of 226Ra to fracture surfaces. As a result of the relatively long half-life of 226Ra (1601 years), significant activity can accumulate on fracture surfaces. The proximity of this sorbed 226Ra to the active ground water flow system allows its decay progeny 222Rn to enter directly into the water. Laboratory analyses of primary porosity and diffusion coefficients of the rock matrix, radon emanation, and ion exchange at fracture surfaces are consistent with the requirements of a diffusion/ion- exchange model. A dipole-brine injection/withdrawal experiment conducted between bedrock boreholes in the high-grade metamorphic and granite rocks at the Hubbard Brook Experimental Forest, Grafton County, New Hampshire, United States (42??56???N, 71??43???W) shows a large activity of 226Ra exchanged from fracture surfaces by a magnesium brine. The 226Ra activity removed by the exchange process is 34 times greater than that of 238U activity. These observations are consistent with the diffusion/ion-exchange model. Elutriate isotopic ratios of 223Ra/226Ra and 238U/226Ra are also consistent with the proposed chemically based diffusion/ion-exchange model.

  6. Alkaline aluminum phosphate glasses for thermal ion-exchanged optical waveguide (United States)

    Wang, Fei; Chen, Baojie; Pun, Edwin Yue Bun; Lin, Hai


    Alkaline aluminum phosphate glasses (NMAP) with excellent chemical durability for thermal ion-exchanged optical waveguide have been designed and investigated. The transition temperature Tg (470 °C) is higher than the ion-exchange temperature (390 °C), which is favorable to sustain the stability of the glass structure for planar waveguide fabrication. The effective diffusion coefficient De of K+-Na+ ion exchange in NMAP glasses is 0.110 μm2/min, indicating that ion exchange can be achieved efficiently in the optical glasses. Single-mode channel waveguide has been fabricated on Er3+/Yb3+ doped NMAP glass substrate by standard micro-fabrication and K+-Na+ ion exchange. The mode field diameter is 9.6 μm in the horizontal direction and 6.0 μm in the vertical direction, respectively, indicating an excellent overlap with a standard single-mode fiber. Judd-Ofelt intensity parameter Ω2 is 5.47 × 10-20 cm2, implying a strong asymmetrical and covalent environment around Er3+ in the optical glasses. The full width at half maximum and maximum stimulated emission cross section of the 4I13/2 → 4I15/2 are 30 nm and 6.80 × 10-21 cm2, respectively, demonstrating that the phosphate glasses are potential glass candidates in developing compact optoelectronic devices. Pr3+, Tm3+ and Ho3+ doped NMAP glasses are promising candidates to fabricate waveguide amplifiers and lasers operating at special telecommunication windows.

  7. Comparison of ion exchange and cw CO2 laser treatment of Nd-doped phosphate laser glass (United States)

    Hui, Gong; Chengfu, Li


    In recent years, the effect of laser pre-irradiation and ion exchange on glasses surface were widely carried out to stabilize their damage thresholds. But comparison of ion exchange and CW CO2 laser treatment is never studied, this paper is devoted to the investigation of this question. Nd-doped phosphate laser glasses were heated with CW CO2 laser radiation and were strengthened by ion exchange. Laser damage thresholds of the surface were measured with 1064 nm 10 ns pulses focused to small spots irradiation. Both ion exchange treatment and CW CO2 laser treatment result in residual compress stress occurred at surface, peak-to- volley and microcracks decreased in surface appearance, and damage thresholds of surfaces increased by a factor of over 2. Polariscope, reflected optical microscope and atomic force microscope are used for stress, damage morphologies and surface topography analysis on glass surface. It is shown that laser condition mechanism is consistent with ion exchange treatment mechanism.

  8. Electrosorptive desalination by carbon nanotubes and nanofibres electrodes and ion-exchange membranes. (United States)

    Li, Haibo; Gao, Yang; Pan, Likun; Zhang, Yanping; Chen, Yiwei; Sun, Zhuo


    A novel membrane capacitive deionization (MCDI) device, integrating both the advantages of carbon nanotubes and carbon nanofibers (CNTs-CNFs) composite film and ion-exchange membrane, was proposed with high removal efficiency, low energy consumption and low cost. The CNTs-CNFs film was synthesized by low pressure and low temperature thermal chemical vapor deposition. Several experiments were conducted to compare desalination performance of MCDI with capacitive deionization (CDI), showing that salt removal of the MCDI system was 49.2% higher than that of the CDI system. The electrosorption isotherms of MCDI and CDI show both of them follow Langmuir adsorption, indicating no change in adsorption behavior when ion-exchange membranes are introduced into CDI system. The better desalination performance of MCDI than that of CDI is due to the minimized ion desorption during electrosorption.

  9. Indirect UV detection-ion-exclusion/cation-exchange chromatography of common inorganic ions with sulfosalicylic acid eluent. (United States)

    Kozaki, Daisuke; Mori, Masanobu; Nakatani, Nobutake; Arai, Kaori; Masuno, Tomoe; Koseki, Masakazu; Itabashi, Hideyuki; Tanaka, Kazuhiko


    Herein, we describe indirect UV detection-ion-exclusion/cation-exchange chromatography (IEC/CEC) on a weakly acidic cation-exchange resin in the H(+)-form (TSKgel Super IC-A/C) using sulfosalicylic acid as the eluent. The goal of the study was to characterize the peaks detected by UV detector. The peak directions of analyte ions in UV at 315 nm were negative because the molar absorbance coefficients of analyte anions and cations were lower than that of the sulfosalicylic acid eluent. Good chromatographic resolution and high signal-to-noise ratios of analyte ions were obtained for the separations performed using 1.1 mM sulfosalicylic acid and 1.5 mM 18-crown-6 as the eluent. The relative standard deviations (RSDs) of the peak areas ranged from 0.6 to 4.9%. Lower detection limits of the analytes were achieved using indirect UV detection at 315 nm (0.23 - 0.98 μM) than those obtained with conductometric detection (CD) (0.61 - 2.1 μM) under the optimized elution conditions. The calibration curves were linear in the range from 0.01 to 1.0 mM except for Cl(-), which was from 0.02 to 2.0 mM. The present method was successfully applied to determine common inorganic ions in a pond water sample.

  10. Removal of charged micropollutants from water by ion-exchange polymers -- effects of competing electrolytes. (United States)

    Bäuerlein, Patrick S; Ter Laak, Thomas L; Hofman-Caris, Roberta C H M; de Voogt, Pim; Droge, Steven T J


    A wide variety of environmental compounds of concern, e.g. pharmaceuticals or illicit drugs, are acids or bases that may predominantly be present as charged species in drinking water sources. These charged micropollutants may prove difficult to remove by currently used water treatment steps (e.g. UV/H(2)O(2), activated carbon (AC) or membranes). We studied the sorption affinity of some ionic organic compounds to both AC and different charged polymeric materials. Ion-exchange polymers may be effective as additional extraction phases in water treatment, because sorption of all charged compounds to oppositely charged polymers was stronger than to AC, especially for the double-charged cation metformin. Tested below 1% of the polymer ion-exchange capacity, the sorption affinity of charged micropollutants is nonlinear and depends on the composition of the aqueous medium. Whereas oppositely charged electrolytes do not impact sorption of organic ions, equally charged electrolytes do influence sorption indicating ion-exchange (IE) to be the main sorption mechanism. For the tested polymers, a tenfold increased salt concentration lowered the IE-sorption affinity by a factor two. Different electrolytes affect IE with organic ions in a similar way as inorganic ions on IE-resins, and no clear differences in this trend were observed between the sulphonated and the carboxylated cation-exchanger. Sorption of organic cations is five fold less in Ca(2+) solutions compared to similar concentrations of Na(+), while that of anionic compounds is three fold weaker in SO(4)(2-) solutions compared to equal concentrations of Cl(-).

  11. 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+

    Energy Technology Data Exchange (ETDEWEB)

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


    Fridriksson and others consistency among the equilibrium constants for three binary pairs was 900 J per mole of charge equivalents (eq) for the 55 C experiments and 2300 J eq-1 for the 85 C experiments. The applicability of the present experimental results and thermodynamic models was assessed by calculating the composition of heulandite in Icelandic geothermal systems from known compositions using the regressed thermodynamic properties of Ca{sup 2+}-Na{sup +} exchange at 85 C. Calculations predict an average Ca mole fraction [defined as Ca/(Ca+Na)] in heulandite of 0.74, in excellent agreement with observed compositions of heulandite from geothermal and metamorphic systems in Iceland (0.75). Thermodynamic data for heulandite ion exchange derived in this study can be used to predict partitioning of Ca, K, Na, and Sr between heulandite and aqueous solutions in geologic systems. Because heulandite is the most effective sink for Sr in basaltic aquifers that have undergone zeolite facies metamorphism, the experimental results of this study will provide essential data for modeling Sr transport in aquifers in low-grade metabasalts.

  12. Model-based prediction of monoclonal antibody retention in ion-exchange chromatography. (United States)

    Guélat, Bertrand; Delegrange, Lydia; Valax, Pascal; Morbidelli, Massimo


    In order to support a model-based process design in ion-exchange chromatography, an adsorption equilibrium model was adapted to predict the protein retention behavior from the amino acid sequence and from structural information on the resin. It is based on the computation of protein-resin interactions with a colloidal model and accounts for the contribution of each ionizable amino acid to the protein charge. As a verification of the protein charge model, the experimental titration curve of a monoclonal antibody was compared to its predicted net charge. Using this protein charge model in the computation of the protein-resin interactions, it is possible to predict the adsorption equilibrium constant (i.e. retention factor or Henry constant) with an explicit pH and salt dependence. The application of the model-based predictions for an in silico screening of the protein retention on various stationary phases or, alternatively, for the comparison of various monoclonal antibodies on a given cation-exchanger was demonstrated. Furthermore, considering the structural differences between charge variants of a monoclonal antibody, it was possible to predict their individual retention times. The selectivity between the side variants and the main isoform of the monoclonal antibody were computed. The comparison with the experimental data showed that the model was reliable with respect to the identification of the operating conditions maximizing the selectivity, i.e. the most promising conditions for a monoclonal antibody variant separation. Such predictions can be useful in reducing the experimental effort to identify the parameter space.

  13. 离子交换法处理含氟氨氮硫酸根废水技术研究与应用%Research and Application of Technology on Waste Water Containing Fluorine,Ammonia Nitrogen and Sulfuric Acid Root by Ion Exchange

    Institute of Scientific and Technical Information of China (English)

    郭永忠; 胡根火; 宋金华


    对钽铌湿法冶炼含氟氨氮硫酸根废水进行了离子交换试验研究。研究结果表明,通过吸附-淋洗-解吸,能实现NH4+、F-、SO2-4三者有效分离:通过吸附过程,能将NH4+与F-、SO2-4分离;通过淋洗过程,用一定浓度的H2 SO4淋洗交换柱,能实现F-与SO2-4分离。工业应用表明:离子交换过程中产生的含低浓度NH3·H2 O溶液、含低浓度HF溶液及含Na2 SO4溶液分别用于蒸馏提浓、洗渣、多效蒸发生产Na2 SO4。%Waste water containing fluorine,ammonia nitrogen and sulfuric acid root of the tantalum niobium hydrometallurgical was carried out in experimental study of ion exchange in this paper. The research results show that through the adsorption-elution-desorption,NH4+,F- and SO2-4 will be sep-arated effectively:NH4+ can be separated from SO2-4 and F- by the process of adsorption;it will be realized the separation of F- and SO2-4 with a certain concentration of H2 SO4 eluting ion exchange column in the elution process. The industrial application shows that in the process of ion exchange which can produce containing low concentration of NH3 ·H2 O solution,low hydrofluoric acid solu-tion and Na2 SO4 solution are used for distillation concentration,wash the tantalum niobium residue, multi effect evaporation production Na2 SO4 ,respectively.

  14. Industrial Application of Ion Beams in KOMAC

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jaesang; Lee, Chanyoung; Kim, Bomsok; Choi, Hyukjun; Kim, Yongki; Kim, Hyungjin; Park, Jaewon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)


    For the last 5 years, we have performed extensive R and D efforts by ion beam to characterize metallic, ceramic, polymeric materials and have supported users from a broad range of institutions, including a large number of industries. So, in this study, through verification on the industrialization feasibility by experiments, it is going to get it started, with cooperation of participatory company, to enter into markets with developed technology and products. Through the ion beam service to users by using ion beam facilities in KOMAC, we are successfully achieved several industrial applications by ion beams. Based on verification on the industrialization feasibility by experiments, we hope to get it started to enter markets with developed technology and products. Ion implantation technology, which is one of ultramodern technologies, can be used in enhancing chemical and physical properties of materials, such as anti-corrosion, wear resistance and electrical conductivity. Comparing with conventional surface modification technologies, it does not generate toxic wastes, which can threaten the environment. It provides precise control of surface thickness and strong adherence of surface material. Therefore, this technology will be used in surface modification along with steady improvement of ion implantation technology.

  15. Testing of CoTreat Inorganic Ion Exchange Media for the Removal of 60Co from Thorp Pond Water

    Energy Technology Data Exchange (ETDEWEB)

    Harjula, R.; Paajanen, A.; Lehto, J.; Tusa, E.; Strandring, P.


    CoTreat, a new inorganic ion exchange media, has been studied in the laboratory to support its application as a pre- coat to existing Funda filters in THORP feed pond plant (Sellafield, UK). This is a novel way of application of CoTreat, which is usually utilized in fixed-bed ion exchange columns in a granular form. The results present the effect of operating conditions (CoTreat dose, pond water chemistry) on CoTreat performance for the removal of Co-57 tracer from simulated pond water. Major findings include the strong dependence of Co-57 decontamination factor (DF) on feed activity. At the 200 Bq/L feed level, the observed DF was 10-20 but rose to 1000 and above when the feed level was increased to 20000 Bq/L. Calcium present in the feed was found to decrease the DF at concentrations higher than 1 ppm. The laboratory studies showed significantly higher DF's than what has been observed in large-scale THORP tests. This discrepancy is likely to be due to the technique used in applying the Co Treat layer to the Thorp HEFP Funda filter. Options for improving Co Treat performance (i.e. application technique) under Funda filter operating conditions are being investigated by BNFL based on this laboratory work.

  16. Analyzing freely dissolved concentrations of cationic surfactant utilizing ion-exchange capability of polyacrylate coated solid-phase microextraction fibers. (United States)

    Chen, Yi; Droge, Steven T J; Hermens, Joop L M


    A 7-μm polyacrylate (PA) coated fiber was successfully employed to determine freely dissolved concentrations of cationic surfactants by solid-phase microextraction (SPME) and utilizing the capability of the PA-coating to sorb organic cations via ion-exchange at carboxylic groups. Measured fiber-water partitioning coefficients (K(fw)) were constant below a fiber loading of 2mmol per liter polyacrylate, allowing for simple and accurate analysis in a concentration range that is relevant from a risk assessment point of view. Ion-exchange was confirmed to be the main sorption mechanism because of a decreasing K(fw) with either higher CaCl(2) concentrations or lower pH, and maximum fiber uptake at the polyacrylate cation-exchange capacity (CEC, at 30mmol/L PA). Fiber-water sorption isotherms were established in various aqueous media in toxicological relevant concentrations. The developed SPME method has a high potential for application in ecotoxicological studies, as demonstrated in sorption studies with humic acid in different electrolyte solutions at aqueous concentrations down to the sub nM range. Cationic surfactant sorption affinities for humic acid also depend on medium composition but are orders of magnitude higher than to the PA fiber on a sorbent weight basis.

  17. Microcrystalline hexagonal tungsten bronze. 1. Basis of ion exchange selectivity for cesium and strontium. (United States)

    Griffith, Christopher S; Luca, Vittorio; Hanna, John V; Pike, Kevin J; Smith, Mark E; Thorogood, Gordon S


    The structural basis of selectivity for cesium and strontium of microcrystalline hexagonal tungsten bronze (HTB) phase Na(x)WO(3+x/2).zH(2)O has been studied using X-ray and neutron diffraction techniques, 1D and 2D (23)Na magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy, and radiochemical ion exchange investigations. For the HTB system, this study has shown that scattering techniques alone provide an incomplete description of the disorder and rapid exchange of water (with tunnel cations) occurring in this system. However, 1D and 2D (23)Na MAS NMR has identified three sodium species within the HTB tunnels-species A, which is located at the center of the hexagonal window and is devoid of coordinated water, and species B and C, which are the di- and monohydrated variants, respectively, of species A. Although species B accords with the traditional crystallographic model of the HTB phase, this work is the first to propose and identify the anhydrous species A and monohydrate species C. The population (total) of species B and C decreases in comparison to that of species A with increasing exchange of either cesium or strontium; that is, species B and C appear more exchangeable than species A. Moreover, a significant proportion of tunnel water is redistributed by these cations. Multiple ion exchange investigations with radiotracers (137)Cs and (85)Sr have shown that for strontium there is a definite advantage in ensuring that any easily exchanged sodium is removed from the HTB tunnels prior to exchange. The decrease in selectivity (wrt cesium) is most probably due to the slightly smaller effective size of Sr(2+); namely, it is less of a good fit for the hexagonal window, ion exchange site. The selectivity of the HTB framework for cesium has been shown unequivocally to be defined by the structure of the hexagonal window, ion exchange site. Compromising the geometry of this window even in the slightest way by either (1) varying the cell volume through

  18. Synthesis and exchange properties of sulfonated poly(phenylene sulfide) with alkali metal ions in organic solvents

    Energy Technology Data Exchange (ETDEWEB)

    Son, Won Keun [Chungnam National Univ., Taejon (Korea, Republic of); Kim, Sang Hern [Taejon National Univ., Taejon (Korea, Republic of); Park, Soo Gil [Chungbuk National Univ., Cheongju (Korea, Republic of)


    Sulfonated poly(phenylene sulfide) (SPPS) polymers were prepared by sulfonation of poly[methyl[4-(phenylthio)phenyl] sulfonium trifluoromethanesulfonate] (PPST) with fumic sulfonic acid (10% SO{sub 3}-H{sub 2}SO{sub 4}) and demethylation with aqueous NaOH solution. The equilibrium constants of ion exchange reactions between alkali metal cations (Li{sup +}, Na{sup +}, and K{sup +}) and SPPS ion exchanger in organic solvents such as in organic solvents such as tetrahydrofuran (THF) and dioxane were measured. The equilibrium constants of ion exchange reactions increased as the polarity of the solvent increased, and the reaction temperature decreased. The equilibrium constants of the ion exchange reaction (K{sub eq}) also increased in the order of Li{sup +}, Na{sup +}, and K{sup +}. To elucidate the spontaneity of the exchange reaction in organic solvents, the enthalpy, entropy, and Gibbs free energy were calculated. The enthalpy of reaction ranged from -0.88 to -1.33 kcal/mol, entropy ranged from 1.42 to 4.41 cal/Kmol, and Gibbs free energy ranged from -1.03 to -2.55 kcal/mol. Therefore, the exchange reactions were spontaneous because the Gibbs free energies were negative. The SPPS ion exchanger and alkali metal ion bounding each other produced good ion exchange capability in organic solvents.

  19. Determination of the maximum retention of cobalt by ion exchange in h-zeolites

    Directory of Open Access Journals (Sweden)

    A. S. Zola


    Full Text Available This work aimed to determine the maximum content of cobalt that can be incorporated by ion exchange in zeolites H-USY, H-Beta, H-Mordenite, and H-ZSM-5. To reach this goal, batch isotherms at 75ºC were constructed after addition of zeolite samples in flasks filled with cobalt nitrate solution. The equilibrium data were fitted to Langmuir, Freundlich, and Tóth adsorption isotherm models. Langmuir was the best model for zeolites H-Beta, H-Mordenite, and H-ZSM-5, whereas experimental data for H-USY were better fitted to the Freundlich isotherm model. From the isotherms, it was possible to determine the maximum cobalt exchange level (q max that can be incorporated in each zeolite through ion exchange. In this sense, H-USY presented the highest q max value (2.40 meq/g zeol, while H-ZSM-5 showed the lowest one (0.64 meq/g zeol. These results also show the influence of the zeolite framework related to the channel system, pore opening, presence of cavities and secondary porosity and SiO2/Al2O3 ratio (SAR on the maximum capacity and behavior of cobalt ion exchange in protonic zeolites.

  20. Preparation of Ion Exchange Films for Solid-Phase Spectrophotometry and Solid-Phase Fluorometry (United States)

    Hill, Carol M.; Street, Kenneth W.; Tanner, Stephen P.; Philipp, Warren H.


    Atomic spectroscopy has dominated the field of trace inorganic analysis because of its high sensitivity and selectivity. The advantages gained by the atomic spectroscopies come with the disadvantage of expensive and often complicated instrumentation. Solid-phase spectroscopy, in which the analyte is preconcentrated on a solid medium followed by conventional spectrophotometry or fluorometry, requires less expensive instrumentation and has considerable sensitivity and selectivity. The sensitivity gains come from preconcentration and the use of chromophore (or fluorophore) developers and the selectivity is achieved by use of ion exchange conditions that favor the analyte in combination with speciative chromophores. Little work has been done to optimize the ion exchange medium (IEM) associated with these techniques. In this report we present a method for making ion exchange polymer films, which considerably simplify the solid-phase spectroscopic techniques. The polymer consists of formaldehyde-crosslinked polyvinyl alcohol with polyacrylic acid entrapped therein. The films are a carboxylate weak cation exchanger in the calcium form. They are mechanically sturdy and optically transparent in the ultraviolet and visible portion of the spectrum, which makes them suitable for spectrophotometry and fluorometry.

  1. Overloading ion-exchange membranes as a purification step for monoclonal antibodies. (United States)

    Brown, Arick; Bill, Jerome; Tully, Timothy; Radhamohan, Asha; Dowd, Chris


    The present study examined the overloading of ion-exchange membrane adsorbers, a form of frontal chromatography, as the final purification step in the production of mAbs (monoclonal antibodies) produced from CHO (Chinese-hamster ovary) cells. Preferential binding of impurities over antibody product was exploited using commercially available cation- and anion-exchange membranes. Three different antibody feedstreams previously purified over Protein A and ion-exchange column chromatography were tested. Feedstream conductivity and pH were adjusted to induce product and impurity adsorption. Membranes were then overloaded in a normal flow mode, resulting in retention of impurities and breakthrough of purified antibody. Although some amount of the product also binds to the membranes (usually or =99% were achieved by marginalizing the losses, typically by loading more than 3 kg mAb/l membrane. Analyses of the purified pools show consistent removal of impurities despite strong mAb-ligand interactions and high membrane loadings. The clearance of host cell proteins was affected by pH and conductivity, but was unaffected by flow rate, membrane properties or scale. The importance of the present study lies in our demonstration of an alternative use of ion-exchange membranes for fast, effective and high yielding purification of mAbs.

  2. Effect of solution concentration and composition on the electrochemical properties of ion exchange membranes for energy conversion (United States)

    Fontananova, E.; Messana, D.; Tufa, R. A.; Nicotera, I.; Kosma, V.; Curcio, E.; van Baak, W.; Drioli, E.; Di Profio, G.


    The electrochemical properties of ion exchange membranes (IEMs) applied for salinity-gradient power (SGP) harvesting, are usually measured using diluited NaCl aqueous solutions because of the prevalence of its constituents ions in natural solutions (e.g. seawater). However, in real applications, the IEMs come in contact with other ionic species than Na+ and Cl- that can have a relevant effect on their properties. As a consequence, the obtained results in many cases are not really representative. The aim of the present study was to investigate the effect of solution concentration and compositions on permselectivity, membrane and interface resistance, for both anion and cation exchange membranes (AEMs and CEMs). Special attention was paid to the influence of the most common multivalent ions in seawater (Mg2+, Ca2+ and SO42-) on the electrochemical properties of the AEM and the CEM. It was possible to discriminate the impact on the AEM from that on the CEM. The results highlighted a strong negative effect of Mg2+ on the CEM (relevant increase of ionic resistance and permselectivity) and, at minor extent, on the AEM (moderate reduction of permselectivity).

  3. Nano-cerium vanadate: a novel inorganic ion exchanger for removal of americium and uranium from simulated aqueous nuclear waste. (United States)

    Banerjee, Chayan; Dudwadkar, Nilesh; Tripathi, Subhash Chandra; Gandhi, Pritam Maniklal; Grover, Vinita; Kaushik, Chetan Prakash; Tyagi, Avesh Kumar


    Cerium vanadate nanopowders were synthesized by a facile low temperature co-precipitation method. The product was characterized by X-ray diffraction and transmission electron microscopy and found to consist of ∼25 nm spherical nanoparticles. The efficiency of these nanopowders for uptake of alpha-emitting radionuclides (233)U (4.82 MeV α) and (241)Am (5.49 MeV α, 60 keV γ) has been investigated. Thermodynamically and kinetically favorable uptake of these radionuclides resulted in their complete removal within 3h from aqueous acidic feed solutions. The uptake capacity was observed to increase with increase in pH as the zeta potential value decreased with the increase in pH but effect of ionic strength was insignificant. Little influence of the ions like Sr(2+), Ru(3+), Fe(3+), etc., in the uptake process indicated CeVO4 nanopowders to be amenable for practical applications. The isotherms indicated predominant uptake of the radioactive metal ions in the solid phase of the exchanger at lower feed concentrations and linear Kielland plots with positive slopes indicated favorable exchange of the metal ions with the nanopowder. Performance comparison with the other sorbents reported indicated excellent potential of nano-cerium vanadate for removing americium and uranium from large volumes of aqueous acidic solutions.

  4. Disiloxanes and Functionalized Silica Gels: One Route, Two Complementary Outcomes-Guanidinium and Pyridinium Ion-Exchangers.

    Directory of Open Access Journals (Sweden)

    Łukasz Tabisz

    Full Text Available Five novel disiloxane compounds comprising guanidinium and pyridinium moieties were obtained with high yields and purity. The verified synthetic pathways were then applied for modification of pre-functionalized silica gel, producing materials with the analogous organic side-chains. These halide-containing compounds and materials were then compared as to their ion-exchange properties: two disiloxanes proved to be effective in leaching different anions (nitrate, benzoate and ascorbate from solid to organic phase, and pyridinium-functionalized silica gels showed selectivity towards perchlorate ion, removing it from methanolic solutions with preference to other singly charged anions. The results presented demonstrate that both compounds and materials containing silicon-carbon bonds can be produced using the same methodology, but offer strikingly different application opportunities. Comparison of their properties provides additional insight into the binding mode of different anions and hints at how the transition from a flexible siloxane bridge to immobilization on solid surface influences anion-binding selectivity. Additionally, one of the siloxane dipodands was found to form a crystalline and poorly soluble nitrate salt (1.316 g/L, water, although it was miscible with a wide range of solvents as a hydrochloride. A possible explanation is given with the help of semi-empirical calculations. A simple, time- and cost-efficient automated potentiometric titration methodology was used as a viable analytical tool for studying ion-exchange processes for both compounds and materials, in addition to standard NMR, FT-IR and ESI-MS methods.

  5. Kinetics and adsorption isotherm of C-phycocyanin from Spirulina platensis on ion-exchange resins

    Directory of Open Access Journals (Sweden)

    L. Sala


    Full Text Available C-phycocyanin is a natural blue dye extracted from Spirulina platensis, which has many applications in the food and pharmaceutical industries. In this paper the effect of pH and temperature on the adsorption of C-phycocyanin onto two different ion exchange resins (Streamline DEAE and Streamline Q XL for expanded bed adsorption chromatography was investigated. Moreover, the kinetics and adsorption isotherm were evaluated. The equilibrium for the Q XL matrix was reached after 60 min, while for DEAE it was only reached after 140 min. C-phycocyanin showed the highest partition coefficient at pH 7.5 for both resins at 25 ºC. The C-phycocyanin adsorption isotherm was very well represented by the Langmuir, Freundlich and Langmuir-Freundlich models, where the estimated values for Qm and Kd obtained by the Langmuir isotherm were, respectively, 33.92 mg.mL-1 and 0.123 mg.mL-1 for DEAE, and 28.12 mg.mL-1 and 0.082 mg.mL-1 for the Q XL matrix. A negative cooperativity was observed for C-phycocyanin binding when the Q XL matrix was used, while the cooperativity was purely independent using the DEAE matrix.

  6. Separation of pegylated recombinant proteins and isoforms on CIM ion exchangers. (United States)

    Gašperšič, Jernej; Podgornik, Aleš; Kramberger, Petra; Jarc, Marko; Jančar, Janez; Žorž, Mirjan; Krajnc, Nika Lendero


    Protein pegylation is a process of covalent attachment of a polyethylene glycol (PEG) group to the protein tertiary structure that can "mask" the agent from the immune system and also increases the hydrodynamic size of the agent. Usually the pegylation prolongs the protein stability in the organism due to reduced renal clearance and provides superior water solubility to hydrophobic molecules. The mono-pegylated form of protein is usually prefered for medical applications. Different conditions with different PEG reagents have to be tested to find optimal pegylation procedure with specific protein. The goal of this study was to prepare screening method for separation of random mono-pegylated protein. Cytochrome C and beta lactoglobulin were pegylated with four reagents and a complete screening of several chromatographic monoliths in ion exchange mode with different buffers was performed to optimaly separate each mono-pegylated protein. The screening method was developed that produces optimal separation of target pegylated protein on CIM monoliths. Because of short chromatographic run time, CIM monoliths are perfect candidates to test alot of parameters. The results obtained show that each protein has its own unique separation parameters (pH, ionexchange ligand, buffer type). Two biopharmaceuticals were isolated using protocol: super human leptin antagonist (SHLA) was purified from inclusion bodies and mono-pegylated super mouse leptin antagonist (SMLA) from pegylated mixture. During study it was observed that the convective interaction media (CIM) monoliths additionally discriminate between protein isoforms pegylated on different sites in 3D structure of the protein.

  7. Exploration of bovine milk proteome in colostral and mature whey using an ion-exchange approach. (United States)

    Le, Anh; Barton, L Douglas; Sanders, Jeff T; Zhang, Qiang


    In addition to milk's nutritional role, it contains immunoglobulins (antibodies) and immunoregulatory proteins that are active in the digestive tract of newborns. However, knowledge of the repertoire of milk proteins remains meager. In this work, we report an ion-exchange-based protein fractionation method that allows in-depth exploration of the whey proteome in bovine milk; 293 unique gene products were identified, of which 176 were newly identified in whey. This work also demonstrated qualitatively for the first time the consistency, albeit differing in protein levels, in milk proteome between colostrum and mature milk (3 mo. post calving). Semiquantitative analysis showed a number of up-regulated proteins in colostrum that may provide extra natural defenses for the neonate. Increased understanding of the composition and functions of bovine milk proteins and their potential health benefits may, in the future, play an important role in nutritional and biomedical applications as properly processed cow's milk proteins could potentially confer the same bioactivity as their human counterparts.

  8. Environmentally benign hardness removal using ion-exchange fibers and snowmelt. (United States)

    Greenleaf, John E; Sengupta, Arup K


    Many industrial unit operations and unit processes require near-complete removal of hardness to avoid scaling in heat-transfer equipment, fouling in membranes, and high consumption of detergents and sequestering chemicals in cooling and wash water. Lime softening and cation exchange are the most commonly used processes practiced to date for hardness removal. Herein, we report and discuss the results and attributes of a new hardness removal process using ion-exchange fibers (IX-fibers). Most importantly, the process uses harvested snowmelt (or rainwater) as the regenerant chemical along with sparged carbon dioxide. Consequently, the spent regenerant does not contain a high concentration of aggressive chemicals such as sodium chloride or acid like traditional ion-exchange processes nor does the process produce voluminous sludges similar to lime softening. The bulk of carbon dioxide consumed during regeneration remains sequestered in the aqueous phase as alkalinity. IX-fibers form the heart of the process. They are essentially thin cylindrical polymeric strands 10-20 microm in diameter. The weak-acid carboxylate functional groups reside near to the surface of these cylindrical fibers. Low intraparticle diffusional resistance is the underlying reason IX-fibers are amenable to efficient regeneration with snowmelt sparged with carbon dioxide. When the carbon dioxide partial pressure is increased to 6.8 atm, over 90% calcium desorption efficiency is obtained. On the contrary, commercial weak-acid ion-exchange resins in spherical bead forms are ineffective for regeneration with carbon-dioxide-sparged snowmelt due to extremely slow ion-exchange kinetics involving counter-transport of Ca2+ and H+.

  9. Characterization of cross-linked cellulosic ion-exchange adsorbents: 2. Protein sorption and transport. (United States)

    Angelo, James M; Cvetkovic, Aleksandar; Gantier, Rene; Lenhoff, Abraham M


    Adsorption behavior in the HyperCel family of cellulosic ion-exchange materials (Pall Corporation) was characterized using methods to assess, quantitatively and qualitatively, the dynamics of protein uptake as well as static adsorption as a function of ionic strength and protein concentration using several model proteins. The three exchangers studied all presented relatively high adsorptive capacities under low ionic strength conditions, comparable to commercially available resins containing polymer functionalization aimed at increasing that particular characteristic. The strong cation- and anion-exchange moieties showed higher sensitivity to increasing salt concentrations, but protein affinity on the salt-tolerant STAR AX HyperCel exchanger remained strong at ionic strengths normally used in downstream processing to elute material fully during ion-exchange chromatography. Very high uptake rates were observed in both batch kinetics experiments and time-series confocal laser scanning microscopy, suggesting low intraparticle transport resistances relative to external film resistance, even at higher bulk protein concentrations where the opposite is typically observed. Electron microscopy imaging of protein adsorbed phases provided additional insight into particle structure that could not be resolved in previous work on the bare resins.

  10. Comparison of the ion exchange uptake of ammonium ion onto New Zealand clinoptilolite and mordenite. (United States)

    Weatherley, L R; Miladinovic, N D


    In this study the uptake performances of the naturally occurring zeolite, clinoptilolite, and of New Zealand mordenite are compared. The uptake of fully ionised ammonium ion from aqueous solutions in the concentration range 0-200 mg/l on to these two materials was compared. The influence of other cations present in water upon the ammonia uptake was also determined. The cations studied were potassium, calcium and magnesium. In all cases the anionic counterion present was chloride. The results showed that the mordenite exhibited higher overall uptake concentrations at equilibrium compared with clinoptilolite at solution concentrations greater than 80 mg/l. Beyond this value, the difference in solid-phase equilibrium concentrations on the mordenite became greater at higher solution-phase ammonium ion concentrations. The effect of the other cations upon uptake of ammonium ion was relatively small. In all cases, the ammonium ion showed the highest uptake on to both the mordenite and the clinoptilolite. In the case of clinoptilolite this was rather an unexpected result since the majority of other work shows clinoptilolite exhibiting a higher affinity for potassium ion compared with ammonium ion. This may be explained by the fact that the clinoptilolite came from volcanic deposits in New Zealand. This is the first such study on this material. At solution-phase equilibrium concentrations of greater than 80 mg/l, the mordenite showed smaller reductions in ammonium ion uptake in the presence of the other cations when compared with clinoptilolite.

  11. Unidirectional Flux Balance of Monovalent Ions in Cells with Na/Na and Li/Na Exchange: Experimental and Computational Studies on Lymphoid U937 Cells.

    Directory of Open Access Journals (Sweden)

    Igor A Vereninov

    Full Text Available Monovalent ion traffic across the cell membrane occurs via various pathways. Evaluation of individual fluxes in whole cell is hampered by their strong interdependence. This difficulty can be overcome by computational analysis of the whole cell flux balance. However, the previous computational studies disregarded ion movement of the self-exchange type. We have taken this exchange into account. The developed software allows determination of unidirectional fluxes of all monovalent ions via the major pathways both under the balanced state and during transient processes. We show how the problem of finding the rate coefficients can be solved by measurement of monovalent ion concentrations and some of the fluxes. Interdependence of fluxes due to the mandatory conditions of electroneutrality and osmotic balance and due to specific effects can be discriminated, enabling one to identify specific changes in ion transfer machinery under varied conditions. To test the effectiveness of the developed approach we made use of the fact that Li/Na exchange is known to be an analogue of the coupled Na/Na exchange. Thus, we compared the predicted and experimental data obtained on U937 cells under varied Li+ concentrations and following inhibition of the sodium pump with ouabain. We found that the coupled Na/Na exchange in U937 cells comprises a significant portion of the entire Na+ turnover. The data showed that the loading of the sodium pump by Li/Na exchange involved in the secondary active Li+ transport at 1-10 mM external Li+ is small. This result may be extrapolated to similar Li+ and Na+ flux relationships in erythrocytes and other cells in patients treated with Li+ in therapeutic doses. The developed computational approach is applicable for studying various cells and can be useful in education for demonstrating the effects of individual transporters and channels on ion gradients, cell water content and membrane potential.

  12. Unidirectional Flux Balance of Monovalent Ions in Cells with Na/Na and Li/Na Exchange: Experimental and Computational Studies on Lymphoid U937 Cells. (United States)

    Vereninov, Igor A; Yurinskaya, Valentina E; Model, Michael A; Vereninov, Alexey A


    Monovalent ion traffic across the cell membrane occurs via various pathways. Evaluation of individual fluxes in whole cell is hampered by their strong interdependence. This difficulty can be overcome by computational analysis of the whole cell flux balance. However, the previous computational studies disregarded ion movement of the self-exchange type. We have taken this exchange into account. The developed software allows determination of unidirectional fluxes of all monovalent ions via the major pathways both under the balanced state and during transient processes. We show how the problem of finding the rate coefficients can be solved by measurement of monovalent ion concentrations and some of the fluxes. Interdependence of fluxes due to the mandatory conditions of electroneutrality and osmotic balance and due to specific effects can be discriminated, enabling one to identify specific changes in ion transfer machinery under varied conditions. To test the effectiveness of the developed approach we made use of the fact that Li/Na exchange is known to be an analogue of the coupled Na/Na exchange. Thus, we compared the predicted and experimental data obtained on U937 cells under varied Li+ concentrations and following inhibition of the sodium pump with ouabain. We found that the coupled Na/Na exchange in U937 cells comprises a significant portion of the entire Na+ turnover. The data showed that the loading of the sodium pump by Li/Na exchange involved in the secondary active Li+ transport at 1-10 mM external Li+ is small. This result may be extrapolated to similar Li+ and Na+ flux relationships in erythrocytes and other cells in patients treated with Li+ in therapeutic doses. The developed computational approach is applicable for studying various cells and can be useful in education for demonstrating the effects of individual transporters and channels on ion gradients, cell water content and membrane potential.

  13. Potentiometric Multisensory Systems with Novel Ion-Exchange Polymer-Based Sensors for Analysis of Drugs

    Directory of Open Access Journals (Sweden)

    Olga V. Bobreshova


    Full Text Available This paper examines potentiometric multisensory systems that consist of novel cross-sensitive PD-sensors (Potential Donnan-sensors. The analytical signal of PD-sensors is the Donnan potential at the ion-exchange polymer/electrolyte test solution interface. The use of novel sensors for the quantitative analysis of multicomponent aqueous solutions of amino acids, vitamins and medical substances is based on protolytic and ion-exchange reactions at the interfaces of ion-exchangers and test solutions. The potentiometric sensor arrays consist of PD-sensors and ion-selective electrodes. Such systems were developed for the multicomponent quantitative analysis of lysine monohydrochloride, thiamine chloride and novocaine hydrochloride solutions that contained salts of alkaline and alkaline-earth metals, as well as for mixed solutions of nicotinic acid and pyridoxine hydrochloride. Multivariate methods of analysis were used for sensor calibration and the analysis of the total response of sensor arrays. The errors of measurement of the electrolytes in aqueous solutions did not exceed 10%. The developed multisensory systems were used to determine the composition of a therapeutic “Mineral salt with low content of sodium chloride” and to determine concentrations of novocaine in sewage samples from a dental clinic.

  14. Adsorption of gaseous formaldehyde and carboxylic acids by ammonium-ion-exchanged alpha-zirconium phosphate. (United States)

    Hayashi, A; Fujimoto, Y; Ogawa, Y; Nakayama, H; Tsuhako, M


    Ammonium-ion-exchanged alpha-Zr(HPO(4))(2)H(2)O (alpha-ZrP) was obtained as a single phase with the interlayer distance of 9.4 A by the ion-exchange of proton with ammonium ion. The ammonium ion-exchanged alpha-ZrP could adsorb ill-smelling gases, such as formaldehyde and carboxylic acids (formic acid, acetic acid, propionic acid, and butyric acid). The adsorption amounts of carboxylic acids increased in the order, butyric acid

  15. Combination of Metal Coordination Tetrahedra and Asymmetric Coordination Geometries of Sb(III) in the Organically Directed Chalcogenidometalates: Structural Diversity and Ion-exchange Properties. (United States)

    Feng, Mei-Ling; Wang, Kai-Yao; Huang, Xiao-Ying


    Chalcogenidometalates exhibit rich and diverse structures and properties applicable to ion exchange, thermoelectrics, photocatalysis, nonlinear optics, and so on. This personal account summarizes our recent progress in constructing chalcogenidometalates by combining metal coordination tetrahedra and the asymmetric coordination geometries of Sb(3+) in the presence of organic species (typically organic amines and metal-organic amine complexes), which has been demonstrated as an effective strategy for synthesizing chalcogenidometalates with diversified structures and interesting properties. The linkage modes of asymmetric SbQn (n = 3, 4) geometries and group 13 (or 14) metal coordination tetrahedra are analyzed, and the secondary building units (SBUs), with different compositions and architectures, are clarified. The crucial role and function of organic species in the formation of chalcogenidometalates are explored, with an emphasis on their powerful structure-directing features. In particular, some chalcogenidometalates in this family exhibit excellent ion-exchange properties for Cs(+) and/or Sr(2+) ions; the factors affecting ion-exchange properties are discussed to understand the underlying ion-exchange mechanism.

  16. Chromatofocusing of peptides and proteins using linear pH gradients formed on strong ion-exchange adsorbents. (United States)

    Kang, Xuezhen; Frey, Douglas D


    Although it is commonly believed that a column packing used for chromatofocusing must have an "even" buffering capacity in order to produce a linear pH gradient, it is demonstrated here that linear pH gradients suitable for chromatofocusing can be produced on a column packing having a minimal buffering capacity. In particular, if either a strong-acid cation-exchange column packing or a strong-base anion-exchange column packing is presaturated with either a weak acid titrated with a strong base, or a weak base titrated with a strong acid, respectively, to the initial pH, then a linear or nearly linear pH gradient can be formed using a polyampholyte elution buffer by taking advantage of the presence of small quantities of weak-acid or weak-base functional groups that generally exist on these types of column packings. Experimental and theoretical studies are used to demonstrate that such systems have potential advantages over traditional chromatofocusing methods in terms of the speed of the separation, the resolution achieved, and the range of applications possible. Among other techniques described, a method for separating tryptic peptides using chromatofocusing and a strong-acid cation-exchange column packing is demonstrated to be a useful alternative to capillary isoelectric focusing and ion-exchange chromatography using a salt gradient for this purpose.

  17. Fate and impact of organics in an immersed membrane bioreactor applied to brine denitrification and ion exchange regeneration. (United States)

    McAdam, Ewan J; Pawlett, Mark; Judd, Simon J


    The application of membrane bioreactors (MBRs) to brine denitrification for ion exchange regeneration has been studied. The developed culture was capable of complete brine denitrification at 50 gNaCl.l(-1). Denitrification reduced to c.60% and c.70% when salinity was respectively increased to 75 and 100g.l(-1), presumed to be due to reduced growth rate and the low imposed solids retention time (10 days). Polysaccharide secretion was not induced by stressed cells following salt shocking, implying that cell lysis did not occur. Fouling propensity, monitored by critical flux, was steady at 12-15l.m(-2).h(-1) during salinity shocking and after brine recirculation, indicating that the system was stable following perturbation. Low molecular weight polysaccharide physically adsorbed onto the nitrate selective anion exchange resin during regeneration reducing exchange capacity by c.6.5% when operating up to complete exhaustion. However, based on a breakthrough threshold of 10 mgNO(3)(-)-N.l(-1) the exchange capacity was comparative to that determined when using freshly produced brine for regeneration. It was concluded that a denitrification MBR was an appropriate technology for IEX spent brine recovery and reuse.

  18. Charge exchange between two nearest neighbour ions immersed in a dense plasma (United States)

    Sauvan, P.; Angelo, P.; Derfoul, H.; Leboucher-Dalimier, E.; Devdariani, A.; Calisti, A.; Talin, B.


    In dense plasmas the quasimolecular model is relevant to describe the radiative properties: two nearest neighbor ions remain close to each other during a time scale of the order of the emission time. Within the frame of a quasistatic approach it has been shown that hydrogen-like spectral line shapes can exhibit satellite-like features. In this work we present the effect on the line shapes of the dynamical collision between the two ions exchanging transiently their bound electron. This model is suitable for the description of the core, the wings and the red satellite-like features. It is post-processed to the self consistent code (IDEFIX) giving the adiabatic transition energies and the oscillator strengths for the transient molecule immersed in a dense free electron bath. It is shown that the positions of the satellites are insensitive to the dynamics of the ion-ion collision. Results for fluorine Lyβ are presented.

  19. Charge-exchange recombination spectroscopy of the plasma ion temperature at the T-10 tokamak (United States)

    Krupin, V. A.; Tugarinov, S. N.; Barsukov, A. G.; Dnestrovskij, A. Yu.; Klyuchnikov, L. A.; Korobov, K. V.; Krasnyanskii, S. A.; Naumenko, N. N.; Nemets, A. R.; Sushkov, A. V.; Tilinin, G. N.


    Charge-exchange recombination spectroscopy (CXRS) based on a diagnostic neutral beam has been developed at the T-10 tokamak. The diagnostics allows one to measure the ion temperature profile in the cross section of the plasma column. In T-10 experiments, the measurement technique was adjusted and the elements of the CXRS diagnostics for ITER were tested. The used spectroscopic equipment makes it possible to reliably determine the ion temperature from the Doppler broadening of impurity lines (helium, carbon), as well as of the spectral lines of the working gas. The profiles of the plasma ion temperature in deuterium and helium discharges were measured at different plasma currents and densities, including with the use of active Doppler measurements of lines of different elements. The validity and reliability of ion temperature measurements performed by means of the developed CXRS diagnostics are analyzed.

  20. Ion exchange equilibrium for some uni-univalent and uni-divalent reaction systems using strongly basic anion exchange resin Duolite A-102 D

    Directory of Open Access Journals (Sweden)

    R.S. Lokhande


    Full Text Available The study on thermodynamics of ion exchange equilibrium for uni-univalent Cl-/I-, Cl-/Br-, and uni-divalent Cl-/SO42-, Cl-/C2O42- reaction systems was carried out using ion exchange resin Duolite A-102 D. The equilibrium constant K was calculated by taking into account the activity coefficient of ions both in solution as well as in the resin phase. The K values calculated for uni-univalent and uni-divalent anion exchange reaction systems was observed to increase with rise in temperature, indicating the endothermic exchange reactions having enthalpy values of 13.7, 38.0, 23.9, 22.9 kJ/mol, respectively.