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Sample records for chemical ion exchangers

  1. 10 CFR Appendix E to Part 110 - Illustrative List of Chemical Exchange or Ion Exchange Enrichment Plant Equipment and Components...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 2 2013-01-01 2013-01-01 false Illustrative List of Chemical Exchange or Ion Exchange.... 110, App. E Appendix E to Part 110—Illustrative List of Chemical Exchange or Ion Exchange Enrichment... chemical exchange and solid-liquid ion exchange. A. In the liquid-liquid chemical exchange...

  2. 10 CFR Appendix E to Part 110 - Illustrative List of Chemical Exchange or Ion Exchange Enrichment Plant Equipment and Components...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 2 2012-01-01 2012-01-01 false Illustrative List of Chemical Exchange or Ion Exchange.... 110, App. E Appendix E to Part 110—Illustrative List of Chemical Exchange or Ion Exchange Enrichment... chemical exchange and solid-liquid ion exchange. A. In the liquid-liquid chemical exchange...

  3. 10 CFR Appendix E to Part 110 - Illustrative List of Chemical Exchange or Ion Exchange Enrichment Plant Equipment and Components...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 2 2014-01-01 2014-01-01 false Illustrative List of Chemical Exchange or Ion Exchange.... 110, App. E Appendix E to Part 110—Illustrative List of Chemical Exchange or Ion Exchange Enrichment... chemical exchange and solid-liquid ion exchange. A. In the liquid-liquid chemical exchange...

  4. 10 CFR Appendix E to Part 110 - Illustrative List of Chemical Exchange or Ion Exchange Enrichment Plant Equipment and Components...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false Illustrative List of Chemical Exchange or Ion Exchange.... 110, App. E Appendix E to Part 110—Illustrative List of Chemical Exchange or Ion Exchange Enrichment... chemical exchange and solid-liquid ion exchange. A. In the liquid-liquid chemical exchange...

  5. 10 CFR Appendix E to Part 110 - Illustrative List of Chemical Exchange or Ion Exchange Enrichment Plant Equipment and Components...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Illustrative List of Chemical Exchange or Ion Exchange.... 110, App. E Appendix E to Part 110—Illustrative List of Chemical Exchange or Ion Exchange Enrichment... chemical exchange and solid-liquid ion exchange. A. In the liquid-liquid chemical exchange...

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

    EPA Science Inventory

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

  7. The chemical precipitation of nickel on ion exchangers and active carbons

    NASA Astrophysics Data System (ADS)

    Khorol'Skaya, S. V.; Zolotukhina, E. V.; Polyanskii, L. N.; Peshkov, S. V.; Kravchenko, T. A.; Krysanov, V. A.

    2010-12-01

    The chemical precipitation of nickel in the form of poorly soluble precipitates in ion exchanger matrices and on active carbons from solutions of nickel chloride and chemical nickel plating electrolytes was studied. The sorption of nickel ions from a solution of nickel chloride occurs most effectively on Purolite D24002 macroporous chelate forming ion exchanger, KU-23-15/100 sulfo cation exchanger, and KU-2-8 gel sulfo cation exchanger. Nickel enters sulfo cation exchangers in the form of counterions, and is adsorbed on Purolite D24002 largely because of complex formation. The subsequent precipitation of nickel in the solid state in matrix pores liberates ionogenic centers, which allows repeated sorption cycles to be performed. After three chemical precipitation cycles under static conditions, the amount of nickel is higher by 170-250% than the ion exchange capacity of the sorbents. The electrolyte of chemical nickel plating contains nickel predominantly in the form of negatively charged and neutral complexes with glycine, which cannot form bonds with the matrices under study. It is therefore reasonable to perform sorption at decreased solution pH values.

  8. Chemical modification of corn fiber with ion-exchanging groups

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pretreated corn fiber was chemically modified with quaternary ammonium group or/and sulfonated with 3-chloro-2-hydroxypropanesulfonic acid under vacuum or at ambient pressure. The soluble fraction was dialyzed through 1 kDa MWCO dialysis tubing and the material retained inside the tubing was filtere...

  9. Ion Exchange Equilibrium and Kinetic Properties of Polyacrylate Films and Applications to Chemical Analysis and Environmental Decontamination

    NASA Technical Reports Server (NTRS)

    Tanner, Stephen P.

    1997-01-01

    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.

  10. Ion exchange technology assessment report

    SciTech Connect

    Duhn, E.F.

    1992-01-01

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

  11. Ion exchange technology assessment report

    SciTech Connect

    Duhn, E.F.

    1992-12-31

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

  12. Swelling behavior of ion exchange resins incorporated in tri-calcium silicate cement matrix: I. Chemical analysis

    NASA Astrophysics Data System (ADS)

    Neji, M.; Bary, B.; Le Bescop, P.; Burlion, N.

    2015-12-01

    This paper presents the first part of a theoretical and experimental work aiming at modeling the chemo-mechanical behavior of composites made up of ion exchange resins (IER) solidified in a tri-calcium silicate cement paste (C3S). Because of ion exchange processes, the volume change of the IER may cause internal pressures leading to the degradation of the material. In this study, a predictive modeling is developed for describing the chemical behavior of such material. It is based on thermodynamic equilibria to determine the evolution of the ion exchange processes, and the potential precipitation of portlandite in the composite. In parallel, a phenomenological study has been set up to understand chemical phenomena related to the swelling mechanisms. The model created has been finally implemented in a finite elements software; the simulation of a laboratory test has been performed and the results compared to experimental data.

  13. A Novel Ion Exchange System to Purify Mixed ISS Waste Water Brines for Chemical Production and Enhanced Water Recovery

    NASA Technical Reports Server (NTRS)

    Lunn, Griffin Michael; Spencer, LaShelle E.; Ruby, Anna Maria; McCaskill, Andrew

    2014-01-01

    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.

  14. Pharmaceutical Applications of Ion-Exchange Resins

    ERIC Educational Resources Information Center

    Elder, David

    2005-01-01

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

  15. Ion exchange phenomena

    SciTech Connect

    Bourg, I.C.; Sposito, G.

    2011-05-01

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

  16. Increasing RO efficiency by chemical-free ion-exchange and Donnan dialysis: Principles and practical implications.

    PubMed

    Vanoppen, Marjolein; Stoffels, Griet; Demuytere, Célestin; Bleyaert, Wouter; Verliefde, Arne R D

    2015-09-01

    Ion-exchange (IEX) and Donnan dialysis (DD) are techniques which can selectively remove cations, limiting scaling in reverse osmosis (RO). If the RO concentrate could be recycled for regeneration of these pre-treatment techniques, RO recovery could be largely increased without the need for chemical addition or additional technologies. In this study, two different RO feed streams (treated industrial waste water and simple tap water) were tested in the envisioned IEX-RO and DD-RO hybrids including RO concentrate recycling. The efficiency of multivalent cation removal depends mainly on the ratio of monovalent to multivalent cations in the feed stream, influencing the ion-exchange efficiency in both IEX and DD. Since the mono-to-multivalent ratio was very high in the waste water, the RO recovery could potentially be increased to 92%. For the tap water, these high RO recoveries could only be reached by adding additional NaCl, because of the low initial monovalent to multivalent ratio in the feed. In both cases, the IEX-RO hybrid proved to be most cost-efficient, due to the high current cost of the membranes used in DD. The membrane cost would have to decrease from ±300 €/m² to 10-30 €/m² - comparable to current reverse osmosis membranes - to achieve a comparable cost. In conclusion, the recycling of RO concentrate to regenerate ion exchange pre-treatment techniques for RO is an interesting option to increase RO recovery without addition of chemicals, but only at high monovalent/multivalent cation-ratios in the feed stream. PMID:25996753

  17. Composite ion exchange materials

    SciTech Connect

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

    1994-12-31

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

  18. Pharmaceutical Applications of Ion-Exchange Resins

    NASA Astrophysics Data System (ADS)

    Elder, David P.

    2005-04-01

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

  19. Charge exchange molecular ion source

    DOEpatents

    Vella, Michael C.

    2003-06-03

    Ions, particularly molecular ions with multiple dopant nucleons per ion, are produced by charge exchange. An ion source contains a minimum of two regions separated by a physical barrier and utilizes charge exchange to enhance production of a desired ion species. The essential elements are a plasma chamber for production of ions of a first species, a physical separator, and a charge transfer chamber where ions of the first species from the plasma chamber undergo charge exchange or transfer with the reactant atom or molecules to produce ions of a second species. Molecular ions may be produced which are useful for ion implantation.

  20. Chemical fractionation and speciation modelling for optimization of ion-exchange processes to recover palladium from industrial wastewater.

    PubMed

    Folens, K; Van Hulle, S; Vanhaecke, F; Du Laing, G

    2016-01-01

    Palladium is used in several industrial applications and, given its high intrinsic value, intense efforts are made to recover the element. In this hydrometallurgic perspective, ion-exchange (IEX) technologies are principal means. Yet, without incorporating the chemical and physical properties of the Pd present in real, plant-specific conditions, the recovery cannot reach its technical nor economic optimum. This study characterized a relevant Pd-containing waste stream of a mirror manufacturer to provide input for a speciation model, predicting the Pd speciation as a function of pH and chloride concentration. Besides the administered neutral PdCl2 form, both positively and negatively charged [PdCln](2-n) species occur depending on the chloride concentration in solution. Purolite C100 and Relite 2AS IEX resins were selected and applied in combination with other treatment steps to optimize the Pd recovery. A combination of the cation and anion exchange resins was found successful to quantitatively recover Pd. Given the fact that Pd was also primarily associated with particles, laboratory-scale experiments focused on physical removal of the Pd-containing flow were conducted, which showed that particle-bound Pd can already be removed by physical pre-treatment prior to IEX, while the ionic fraction remains fully susceptible to the IEX mechanism. PMID:27054747

  1. Biological Ion Exchanger Resins

    PubMed Central

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

    1971-01-01

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

  2. Comparison of methods for nutrient measurement in calcareous soils: Ion-exchange resin bag, capsule, membrane, and chemical extractions

    USGS Publications Warehouse

    Sherrod, S.K.; Belnap, J.; Miller, M.E.

    2002-01-01

    Four methods for measuring quantities of 12 plant-available nutrients were compared using three sandy soils in a series of three experiments. Three of the methods use different ion-exchange resin forms-bags, capsules, and membranes-and the fourth was conventional chemical extraction. The first experiment compared nutrient extraction data from a medium of sand saturated with a nutrient solution. The second and third experiments used Nakai and Sheppard series soils from Canyonlands National Park, which are relatively high in soil carbonates. The second experiment compared nutrient extraction data provided by the four methods from soils equilibrated at two temperatures, "warm" and "cold." The third experiment extracted nutrients from the same soils in a field equilibration. Our results show that the four extraction techniques are not comparable. This conclusion is due to differences among the methods in the net quantities of nutrients extracted from equivalent soil volumes, in the proportional representation of nutrients within similar soils and treatments, in the measurement of nutrients that were added in known quantities, and even in the order of nutrients ranked by net abundance. We attribute the disparities in nutrient measurement among the different resin forms to interacting effects of the inherent differences in resin exchange capacity, differences among nutrients in their resin affinities, and possibly the relatively short equilibration time for laboratory trials. One constraint for measuring carbonate-related nutrients in high-carbonate soils is the conventional ammonium acetate extraction method, which we suspect of dissolving fine CaCO3 particles that are more abundant in Nakai series soils, resulting in erroneously high Ca2+ estimates. For study of plant-available nutrients, it is important to identify the nutrients of foremost interest and understand differences in their resin sorption dynamics to determine the most appropriate extraction method.

  3. Ion-exchange hollow fibers

    NASA Technical Reports Server (NTRS)

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

    1976-01-01

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

  4. Ion-exchange hollow fibers

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

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

  5. Ion-exchange hollow fibers

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

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

  6. Porous Ceramic Spheres from Ion Exchange Resin

    NASA Technical Reports Server (NTRS)

    Dynys, Fred

    2005-01-01

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

  7. Electrically switched ion exchange

    SciTech Connect

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

    1997-10-01

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

  8. Ion exchange - Simulation and experiment

    NASA Technical Reports Server (NTRS)

    Herrmann, Cal C.; Finn, John E.

    1991-01-01

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

  9. Modeling of Crystalline Silicotitanate Ion Exchange Columns

    SciTech Connect

    Walker, D.D.

    1999-03-09

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

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

    DOEpatents

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

    1979-01-01

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

  11. Solvent Extraction and Ion Exchange in Radiochemistry

    NASA Astrophysics Data System (ADS)

    Skarnemark, G.

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

  12. Vitrification of ion exchange resins

    DOEpatents

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

    2001-01-01

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

  13. A Colorful Ion Exchange Experiment

    NASA Astrophysics Data System (ADS)

    Mendes, Adélio

    1999-11-01

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

  14. Electrically Switched Cesium Ion Exchange

    SciTech Connect

    JPH Sukamto; ML Lilga; RK Orth

    1998-10-23

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

  15. Phosphonic acid based ion exchange resins

    DOEpatents

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

    1994-01-25

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

  16. Phosphonic acid based ion exchange resins

    DOEpatents

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

    1996-07-23

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

  17. Phosphonic acid based ion exchange resins

    DOEpatents

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

    1996-01-01

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

  18. Phosphonic acid based ion exchange resins

    DOEpatents

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

    1994-01-01

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

  19. Grafted methylenediphosphonate ion exchange resins

    DOEpatents

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

    1997-04-08

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

  20. Grafted methylenediphosphonate ion exchange resins

    DOEpatents

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

    1997-01-01

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

  1. Grafted methylenediphosphonate ion exchange resins

    DOEpatents

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

    1998-01-27

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

  2. Radiation Studies with Argentine Ion Exchange Material

    SciTech Connect

    Crawford, C.L.

    2002-06-28

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

  3. Chemical and radiation stability of SuperLig{reg_sign}644, resorcinol-formaldehyde, and CS-100 cesium ion exchange materials

    SciTech Connect

    Brown, G.N.; Adami, S.R.; Bray, L.A.

    1995-09-01

    At the request of the Initial Pretreatment Module Project within Westinghouse Hanford Company, Pacific Northwest Laboratory (PNL) conducted this study for the Efficient Separations and Processing Crosscutting Program (ESP) under the task ``Develop and Test Sorbents.`` The purpose of the study was to assess and compare the chemical and radiolytic stability of several cesium-selective ion exchange materials in simulated alkaline Hanford tank waste matrices. Pretreatment of nuclear process wastes to remove of cesium and other radionuclides by ion exchange was proposed previously as one method of minimizing the amount of high-level radioactive waste at Hanford. In this study, PNL evaluated three cesium-selective materials SuperLig{reg_sign}644, resorcinol-formaldehyde (R-F), and CS-100 for chemical and radiation stability in 1 M NaOH and a simulated neutralized current acid waste (NCAW). The objective of the study is to investigate the stability of the newly produced SuperLig{reg_sign}644 under a variety of conditions in an attempt to simulate and predict the degradation process. The following specific conclusions and recommendations resulted from the study.

  4. Modelling of the interaction between chemical and mechanical behaviour of ion exchange resins incorporated into a cement-based matrix

    NASA Astrophysics Data System (ADS)

    Neji, M.; Bary, B.; Burlion, N.; Le Bescop, P.

    2013-07-01

    In this paper, we present a predictive model, based on experimental data, to determine the macroscopic mechanical behavior of a material made up of ion exchange resins solidified into a CEM III cement paste. Some observations have shown that in some cases, a significant macroscopic expansion of this composite material may be expected, due to internal pressures generated in the resin. To build the model, we made the choice to break down the problem in two scale's studies. The first deals with the mechanical behavior of the different heterogeneities of the composite, i.e. the resin and the cement paste. The second upscales the information from the heterogeneities to the Representative Elementary Volume (REV) of the composite. The heterogeneities effects are taken into account in the REV by applying a homogenization method derived from the Eshelby theory combined with an interaction coefficient drawn from the poroelasticity theory. At the first scale, from the second thermodynamic law, a formulation is developed to estimate the resin microscopic swelling. The model response is illustrated on a simple example showing the impact of the calculated internal pressure, on the macroscopic strain.

  5. Ion Exchange and Liquid Column Chromatography.

    ERIC Educational Resources Information Center

    Walton, Harold F.

    1980-01-01

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

  6. Effect of resin charged functional group, porosity, and chemical matrix on the long-term pharmaceutical removal mechanism by conventional ion exchange resins.

    PubMed

    Wang, Wei; Li, Xiaofeng; Yuan, Shengliu; Sun, Jian; Zheng, Shaokui

    2016-10-01

    This study attempted to clarify the long-term pharmaceutical removal mechanism from sewage treatment plant effluent during the cyclical adsorption-regeneration operation of 5 commercial resin-based fixed-bed reactors with the simultaneous occurrence of electrostatic interactions and complex non-electrostatic interactions. It examined 12 pharmaceuticals belonging to 10 therapeutic classes with different predominant existing forms and hydrophobicities. Furthermore, the effect of the resin charged functional group (strong-base vs. strong-acid vs. non-ionic), porosity (macroporous vs. gel), and chemical matrix (polystyrenic vs. polyacrylic) on the mechanism was investigated to optimize resin properties and achieve higher pharmaceutical removal. The results reported herein indicate the importance of non-electrostatic interactions between pharmaceuticals and the resin backbone during short-term cyclical operation (i.e., the 1st adsorption-regeneration cycle). With the development of cyclical operation, however, non-electrostatic interaction-induced pharmaceutical removal generally decreased and even disappeared when equilibrium was achieved between the influent and the resin. Despite pharmaceutical therapeutic class or hydrophilicity, anion (or cation) exchange resin preferentially removed those pharmaceuticals that were predominantly present as organic anions (or cations) by ion exchange process during long-term cyclical operation (i.e., ≥6 adsorption-regeneration cycles). Besides pharmaceuticals predominantly present as undissociated molecules, some amphoteric pharmaceuticals containing large amounts of zwitterions were also difficult to remove by ion exchange resin. Additionally, neither resin porosity nor chemical matrix had any significant effect on the long-term pharmaceutical removal mechanism. PMID:27367175

  7. Ion exchange purification of scandium

    DOEpatents

    Herchenroeder, Laurie A.; Burkholder, Harvey R.

    1990-10-23

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

  8. Ion exchange purification of scandium

    DOEpatents

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

    1990-10-23

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

  9. Electrically controlled cesium ion exchange

    SciTech Connect

    Lilga, M.

    1996-10-01

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

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

    EPA Science Inventory

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

  11. PRTR ion exchange vault column sampling

    SciTech Connect

    Cornwell, B.C.

    1995-03-14

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

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

    DOEpatents

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

    2007-12-25

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

  13. Facility produced charge-exchange ions

    NASA Technical Reports Server (NTRS)

    Carruth, M. R., Jr.

    1981-01-01

    These facility produced ions are created by charge-exchange collisions between neutral atoms and energetic thruster beam ions. The result of the electron transfer is an energetic neutral atom and an ion of only thermal energy. There are true charge-exchange ions produced by collisions with neutrals escaping from the ion thruster and being charge-exchange ionized before the neutral intercepts the tank wall. The facility produced charge-exchange ions will not exist in space and therefore, represent a source of error where measurements involving ion thruster plasmas and their density are involved. The quantity of facility produced ions in a test chamber with a 30 cm mercury ion thruster was determined.

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

    ERIC Educational Resources Information Center

    Johnson, Brian J.

    2014-01-01

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

  15. Ion Exchange Formation via Sulfonated Bicomponent Nonwovens

    NASA Astrophysics Data System (ADS)

    Stoughton, Hannah L.

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

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

    PubMed

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

    2016-05-01

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

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

    PubMed

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

    2015-03-01

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

  18. Titania bound sodium titanate ion exchanger

    DOEpatents

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

    1999-03-23

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

  19. Ion Exchange and Adsorption of Inorganic Contaminants

    EPA Science Inventory

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

  20. Ion exchange in the nuclear industry

    SciTech Connect

    Bibler, J.P.

    1990-12-31

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

  1. Ion exchange in the nuclear industry

    SciTech Connect

    Bibler, J.P.

    1990-01-01

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

  2. Ion Exchange Membrane Influence on Ohmic Resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    DOEpatents

    Dreyfuss, Robert M.

    1976-01-01

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

  4. Heat Exchanger Lab for Chemical Engineering Undergraduates

    ERIC Educational Resources Information Center

    Rajala, Jonathan W.; Evans, Edward A.; Chase, George G.

    2015-01-01

    Third year chemical engineering undergraduate students at The University of Akron designed and fabricated a heat exchanger for a stirred tank as part of a Chemical Engineering Laboratory course. The heat exchanger portion of this course was three weeks of the fifteen week long semester. Students applied concepts of scale-up and dimensional…

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

    SciTech Connect

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

    2011-01-03

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

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

    SciTech Connect

    Not Available

    1994-04-01

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

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

    SciTech Connect

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

    2013-04-24

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

  8. Silicon Removal from Waste Simulants via Ion Exchange

    SciTech Connect

    Wilmarth, W.R.

    2002-09-23

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

  9. The many faces of ion-exchange resins

    SciTech Connect

    McNutty, J.T.

    1997-06-01

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

  10. ION EXCHANGE SOFTENING: EFFECTS ON METAL CONCENTRATIONS

    EPA Science Inventory

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

  11. Radiation testing of organic ion exchange resins

    SciTech Connect

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

    1995-09-01

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

  12. Inorganic ion exchangers for nuclear waste remediation

    SciTech Connect

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

    1997-10-01

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

  13. 21 CFR 173.20 - Ion-exchange membranes.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

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

  14. 21 CFR 173.20 - Ion-exchange membranes.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

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

  15. 21 CFR 173.20 - Ion-exchange membranes.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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

  16. 21 CFR 173.20 - Ion-exchange membranes.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

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

  17. 21 CFR 173.20 - Ion-exchange membranes.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  18. Cesium Separation Using Electrically Switched Ion Exchange

    SciTech Connect

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

    2001-09-01

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

  19. MINOR ACTINIDE SEPARATIONS USING ION EXCHANGERS OR IONIC LIQUIDS

    SciTech Connect

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

    2011-09-20

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

  20. Evaluation of electrochemical ion exchange for cesium elution

    SciTech Connect

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

    1996-04-01

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

  1. Effect of polyamine reagents on exchange capacity in ion exchangers

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

    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.

  2. Ion thruster charge-exchange plasma flow

    NASA Technical Reports Server (NTRS)

    Carruth, M. R., Jr.; Gabriel, S. B.; Kitamura, S.

    1982-01-01

    The electron bombardment ion thruster has been under development for a number of years and during this time, studies of the plasmas produced by the thrusters and their interactions with spacecraft have been evaluated, based on available data. Due to diagnostic techniques used and facility effects, there is uncertainty as to the reliability of data from these early studies. This paper presents data on the flow of the charge-exchange plasma produced just downstream of the thruster's ion optics. The 'end-effect' of a cylindrical Langmuir probe is used to determine ion density and directed ion velocity. Results are compared with data obtained from a retarding potential analyzer-Faraday cup.

  3. Organic ion exchange resin separation methods evaluation

    SciTech Connect

    Witwer, K.S.

    1998-05-27

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

  4. Commercial Ion Exchange Resin Vitrification Studies

    SciTech Connect

    Cicero-Herman, C.A

    2002-06-28

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

  5. Cesium-specific phenolic ion exchange resin

    DOEpatents

    Bibler, Jane P.; Wallace, Richard M.

    1995-01-01

    A phenolic, cesium-specific, cation exchange resin is prepared by neutralizing resorcinol with potassium hydroxide, condensing/polymerizing the resulting intermediate with formaldehyde, heat-curing the resulting polymer to effect cross-linking and grinding it to desired particle size for use. This resin will selectively and efficiently adsorb cesium ions in the presence of a high concentration of sodium ions with a low carbon to cesium ratio.

  6. Cesium-specific phenolic ion exchange resin

    DOEpatents

    Bibler, J.P.; Wallace, R.M.

    1995-08-15

    A phenolic, cesium-specific, cation exchange resin is prepared by neutralizing resorcinol with potassium hydroxide, condensing/polymerizing the resulting intermediate with formaldehyde, heat-curing the resulting polymer to effect cross-linking and grinding it to desired particle size for use. This resin will selectively and efficiently adsorb cesium ions in the presence of a high concentration of sodium ions with a low carbon to cesium ratio. 2 figs.

  7. Waste separation and pretreatment using crystalline silicotitanate ion exchangers

    SciTech Connect

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

    1997-10-01

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

  8. Thermal Analysis of LANL Ion Exchange Column

    SciTech Connect

    Laurinat, J.E.

    1999-06-16

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

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

    SciTech Connect

    1995-01-01

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

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

    SciTech Connect

    1996-01-01

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

  11. Use of mixed-mode ion exchange sorbent for the passive sampling of organic acids by polar organic chemical integrative sampler (POCIS).

    PubMed

    Fauvelle, Vincent; Mazzella, Nicolas; Delmas, François; Madarassou, Karine; Eon, Mélissa; Budzinski, Hélène

    2012-12-18

    Acidic herbicides are increasingly monitored in freshwater, since their high solubility favors their rapid transfer to the water phase. Therefore, contaminant levels in the water can vary rapidly and passive sampling would be preferred over spot sampling to integrate all pollution events over a given exposure time. In this work, we propose to compare the conventional pharmaceutical polar organic chemical integrative sampler (POCIS) with modified POCISs containing two different receiving phases: a standard polystyrene divinylbenzene polymer with a higher specific surface area (Chromabond HR-X) and a mixed-mode anion exchange sorbent providing additional strong anion exchange interaction sites (Oasis MAX). Due to its hydrophobic character, Chromabond HR-X had little interaction with water (no sampling of acidic herbicides); whereas Oasis MAX provided acceptable sampling parameters (longer kinetic regime together with higher sampling rates). Additional experiments with POCIS-MAX showed no influence of nitrates on analyte uptakes, and linear isotherms reaching 10 μg L⁻¹, supporting the applicability of this device for the sampling of organic acids in continental water. The performance and reference compound (PRC) approach would be then applicable for POCIS-MAX if no competition is observed with other anions, especially organic acids (e.g., humic acids). PMID:23176704

  12. SPEEDUP{trademark} ion exchange column model

    SciTech Connect

    Hang, T.

    2000-03-06

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

  13. Liquid membrane coated ion-exchange column solids

    DOEpatents

    Barkey, Dale P.

    1989-01-01

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

  14. Liquid membrane coated ion-exchange column solids

    DOEpatents

    Barkey, Dale P.

    1988-01-01

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

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

    SciTech Connect

    Holst, L.; Hesboel, R.

    1995-12-31

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

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

    ERIC Educational Resources Information Center

    Johnson, Steven D.

    1996-01-01

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

  17. ION EXCHANGE ADSORPTION PROCESS FOR PLUTONIUM SEPARATION

    DOEpatents

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

    1961-07-11

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

  18. Poisson-Fermi Modeling of the Ion Exchange Mechanism of the Sodium/Calcium Exchanger.

    PubMed

    Liu, Jinn-Liang; Hsieh, Hann-Jeng; Eisenberg, Bob

    2016-03-17

    The ion exchange mechanism of the sodium/calcium exchanger (NCX) crystallized by Liao et al. in 2012 is studied using the Poisson-Fermi theory developed by Liu and Eisenberg in 2014. A cycle of binding and unbinding is proposed to account for the Na(+)/Ca(2+) exchange function of the NCX molecule. Outputs of the theory include electric and steric fields of ions with different sizes, correlations of ions of different charges, and polarization of water, along with number densities of ions, water molecules, and interstitial voids. We calculate the electrostatic and steric potentials of the four binding sites in NCX, i.e., three Na(+) binding sites and one Ca(2+) binding site, with protein charges provided by the software PDB2PQR. The energy profiles of Na(+) and Ca(2+) ions along their respective Na(+) and Ca(2+) pathways in experimental conditions enable us to explain the fundamental mechanism of NCX that extrudes intracellular Ca(2+) across the cell membrane against its chemical gradient by using the downhill gradient of Na(+). Atomic and numerical details of the binding sites are given to illustrate the 3 Na(+):1 Ca(2+) stoichiometry of NCX. The protein NCX is a catalyst. It does not provide (free) energy for transport. All energy for transport in our model comes from the ions in surrounding baths. PMID:26906748

  19. Porous solid ion exchange wafer for immobilizing biomolecules

    DOEpatents

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

    2007-12-11

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

  20. Exchange coupled ferrite nanocomposites through chemical synthesis.

    PubMed

    Dai, Qilin; Patel, Ketan; Ren, Shenqiang

    2016-08-16

    Exchange coupling between magnetically hard and soft phases has the potential to yield a large gain in the energy product. In this work, we present a scalable chemical synthetic route to produce magnetic iron oxide based nanocomposites, consisting of cobalt ferrite (CoFe2O4) and strontium ferrite (SrFe12O19) components. PMID:27476744

  1. Di-D-fructose dianhydride-enriched products by acid ion-exchange resin-promoted caramelization of D-fructose: chemical analyses.

    PubMed

    Suárez-Pereira, Elena; Rubio, Enrique M; Pilard, Serge; Ortiz Mellet, Carmen; García Fernández, José M

    2010-02-10

    Caramelization commonly occurs when sugars, or products containing a high proportion of sugars, are heated either dry or in concentrated aqueous solutions, alone or in the presence of certain additives. Upon thermal treatment of sugars, dehydration and self-condensation reactions occur, giving rise to volatiles (principally 2-hydroxymethylfurfural, HMF), pigments (melanoidines) and oligosaccharidic material, among which di-D-fructose dianhydrides (DFAs) and glycosylated DFA derivatives of different degree of polymerization (DP) have been identified. This study reports a methodology to produce caramel-like products with a high content of DFAs and oligosaccharides thereof from commercial D-fructose based on the use of acid ion-exchange resins as caramelization promotors. The rate of formation of these compounds as a function of D-fructose concentration, catalyst proportion, temperature, catalyst nature and particle size has been investigated. The use of sulfonic acid resins allows conducting caramelization at remarkable low temperatures (70-90 degrees C) to reach conversions into DFA derivatives up to 70-80% in 1-2 h, with relative proportions of HMF < 2%.The relative abundance of individual DFA structures can be modulated by acting on the catalyst nature and reaction conditions, which offers a unique opportunity for nutritional studies of DFA-enriched products with well-defined compositions. PMID:20039676

  2. Charge exchange lifetimes for ions in the magnetosphere

    NASA Technical Reports Server (NTRS)

    Smith, P. H.; Bewtra, N. K.

    1977-01-01

    Latest and best measurements of physical quantities involved in complete calculation of the charge exchange lifetime of mirroring magnetospheric ions are coalesced and summarized. It is critical that the charge exchange lifetimes for ions be known as accurately as possible in order to apply the charge exchange mechanism to ion phenomena within the earth's magnetosphere.

  3. 21 CFR 173.21 - Perfluorinated ion exchange membranes.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

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

  4. 21 CFR 173.21 - Perfluorinated ion exchange membranes.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

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

  5. 21 CFR 173.21 - Perfluorinated ion exchange membranes.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  6. 21 CFR 173.21 - Perfluorinated ion exchange membranes.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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

  7. 21 CFR 173.21 - Perfluorinated ion exchange membranes.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

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

  8. Cesium and strontium ion specific exchangers

    SciTech Connect

    Yates, S.

    1996-10-01

    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.

  9. PRTR ion exchange vault water removal

    SciTech Connect

    Ham, J.E.

    1995-11-01

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

  10. Ion Exchange Temperature Testing with SRF Resin

    SciTech Connect

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

    2012-03-01

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

  11. Radiation degradation in EPICOR-2 ion exchange resins

    SciTech Connect

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

    1990-09-01

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

  12. Potentiometric sensors with ion-exchange Donnan exclusion membranes.

    PubMed

    Grygolowicz-Pawlak, Ewa; Crespo, Gastón A; Ghahraman Afshar, Majid; Mistlberger, Günter; Bakker, Eric

    2013-07-01

    Potentiometric sensors that exhibit a non-Hofmeister selectivity sequence are normally designed by selective chemical recognition elements in the membrane. In other situations, when used as detectors in separation science, for example, membranes that respond equally to most ions are preferred. With so-called liquid membranes, a low selectivity is difficult to accomplish since these membranes are intrinsically responsive to lipophilic species. Instead, the high solubility of sample lipids in an ionophore-free sensing matrix results in a deterioration of the response. We explore here potentiometric sensors on the basis of ion-exchange membranes commonly used in fuel cell applications and electrodialysis, which have so far not found their way into the field of ion-selective electrodes. These membranes act as Donnan exclusion membranes as the ions are not stripped of their hydration shell as they interact with the membrane. Because of this, lipophilic ions are no longer preferred over hydrophilic ones, making them promising candidates for the detection of abundant ions in the presence of lipophilic ones or as detectors in separation science. Two types of cation-exchanger membranes and one anion-exchange membrane were characterized, and potentiometric measuring ranges were found to be Nernstian over a wide range down to about 10 μM concentrations. Depending on the specific membrane, lipophilic ions gave equal response to hydrophilic ones or were even somewhat discriminated. The medium and long-term stability and reproducibility of the electrode signals were found to be promising when evaluated in synthetic and whole blood samples. PMID:23731350

  13. Novel silica-based ion exchange resin

    SciTech Connect

    1997-11-01

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

  14. Ion exchange properties of humus acids

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

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

  15. Sorption of tellurium ion from aqueous solutions by anion-exchangers and amphoteric ion-exchangers

    SciTech Connect

    Dreipa, E.F.; Pakholkov, V.S.; Luk'yanov, S.A.

    1981-10-20

    Sorption of tellurium from solutions of telluric acid under dynamic and static conditions by anion-exchangers and amphoteric ion-exchangers containing various ionic groups was studied and the influence of the ion form, pH of the medium, presence of electrolytes, and the H/sub 6/TeO/sub 6/ concentration in the original solutions was determined. The mechanism of sorption of tellurium (VI) by anion-exchangers was deduced from sorption and IR-spectroscopic data. Differences in the behavior of tellurium and selenium were used for separating these elements in 0.05 N H/sub 2/SeO/sub 4/ + 0.05 N H/sub 6/TeO/sub 6/ solution of pH = 1.0 with the aid of EDE-10P anion-exchange resin.

  16. Separation of uranium isotopes by chemical exchange

    DOEpatents

    Ogle, P.R. Jr.

    1974-02-26

    A chemical exchange method is provided for separating /sup 235/U from / sup 238/U comprising contacting a first phase containing UF/sub 6/ with a second phase containing a compound selected from the group consisting of NOUF/sub 6/, NOUF/sub 7/, and NO/sub 2/UF/sub 7/ until the U Fsub 6/ in the first phase becomes enriched in the /sup 235/U isotope. (Official Gazette)

  17. Anion exchangers with branched functional ion exchange layers of different hydrophilicity for ion chromatography.

    PubMed

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

    2015-08-21

    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

  18. A novel electrochemical ion exchange system and its application in water treatment.

    PubMed

    Li, Yansheng; Li, Yongbin; Liu, Zhigang; Wu, Tao; Tian, Ying

    2011-06-01

    A novel electrochemical ion exchange system with porous cylinder electrodes is proposed for treatment of wastewater. This system can be used for desalination without the costly ion-exchange membrane and extra chemical reagents. Since the electrodes are completely uniform and no ion-exchange membrane was used in this system, it can be operated by switching anodes and cathodes flexibly for eliminating the scaling on the surface of electrodes. The strong base ion-exchange resin grains placed among the anode and cathode have played as supporting electrolyte, which is capable for the treatment of wastewater with low conductivity. The concentrated and neutralized anolyte containing chlorine is effective for disinfection and contaminants removal. Under the experimental conditions, the removal percentage of total dissolved salts was 83% and the removal percentage of chemical oxygen demand was 92% without consumption of extra chemical reagents. PMID:25084577

  19. Solidification of ion exchange resin wastes

    SciTech Connect

    Not Available

    1982-08-01

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

  20. Ion exchange polymers and method for making

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

  1. Biodegradation of ion-exchange media

    SciTech Connect

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

    1988-01-01

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

  2. Erbium doping of lithium niobate by the ion exchange process for high-gain optical amplifiers

    NASA Astrophysics Data System (ADS)

    Caccavale, Frederico; Fedorov, Vyacheslav A.; Korkishko, Yuri N.; Morozova, Tamara V.; Sada, Cinzia; Segato, Francesco

    2000-04-01

    The erbium-lithium ion exchange is presented as a method for the erbium local doping of lithium niobate crystals. Ion exchange process is performed immersing the LiNbO3 substrates in a liquid melt, containing erbium ions; due to their high mobility, the lithium ions migrate from the crystal to the melt, and are replaced by erbium ions. A systematic analysis of the doping process is performed, and the influence of the process parameters is investigated: exchange time and temperature, crystal cut direction, composition and chemical reactivity of the Er ions liquid source. By structural (X-Ray Diffraction and Rutherford Backscattering Spectrometry), compositional (Secondary Ion Mass Spectrometry) and spectroscopic techniques (optical spectroscopy and micro-luminescence), the formation of lithium deficient phases and the incorporation of the Er ions into the LiNbO3 matrix is studied.

  3. Selectivity of ion exchangers in extracting cesium and rubidium from alkaline solutions

    NASA Astrophysics Data System (ADS)

    Shelkovnikova, L. A.; Kargov, S. I.; Gavlina, O. T.; Ivanov, V. A.; Al'tshuler, G. N.

    2013-01-01

    We compare the ion exchange selectivity of phenol-type sorbents based on phenol formaldehyde resins, products of condensation of diatomic phenols with formaldehyde, and crosslinked polymer based on C-phenyl[4]resorcinarene resin, for cesium and rubidium ions. It is shown that phenol formaldehyde sorbents are the ones most selective. The interaction of alkali metal cations with the anion of calix[4]arene is investigated via quantum-chemical modeling. It is shown that the selectivity toward cesium and rubidium ions in ion exchangers of the phenolic type is not due to specific interactions of ions with phenolic groups.

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

    DOEpatents

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

    1985-05-07

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

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

    ERIC Educational Resources Information Center

    Foster, N.; And Others

    1985-01-01

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

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

    DOEpatents

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

    1985-05-07

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

  7. Multicomponent liquid ion exchange with chabazite zeolites

    SciTech Connect

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

    1993-10-01

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

  8. Radionuclide Leaching from Organic Ion Exchange Resin

    SciTech Connect

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

    1999-04-02

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

  9. 21 CFR 173.25 - Ion-exchange resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  10. 21 CFR 173.25 - Ion-exchange resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1982-01-01

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

  12. Stabilization of copper nanoparticles with volume- and surface-distribution inside ion-exchange matrices

    NASA Astrophysics Data System (ADS)

    Kravchenko, T. A.; Sakardina, E. A.; Kalinichev, A. I.; Zolotukhina, E. V.

    2015-09-01

    Nanocomposites characterized by the surface and volume distributions of deposited copper nanoparticles are obtained via the chemical deposition of copper onto sulfonic acid and carboxylic cation exchanger and strongly basic anion exchanger matrices. The electrode behavior of the synthesized composites in CuSO4 solution is studied by open-circuit chronopotentiometry. The effect the nature of the fixed centers of the ion-exchange matrix has on the initial state of metallic particles and the processes that occur in solutions of their metal ions is established from the deviation of the nanocomposites' electrode potential from the potential of a compact electrode and the nature of its change over time. It is shown that the mechanism behind the interaction of the matrix and metal ions (ion exchange, non-exchange absorption, complexation) determines not only the initial size and distribution of metal particles, but also the rate at which they achieve aggregative stability.

  13. Effects of ionizing radiation on modern ion exchange materials

    SciTech Connect

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

    1993-10-01

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

  14. Coupled acoustic-gravity field for dynamic evaluation of ion exchange with a single resin bead.

    PubMed

    Kanazaki, Takahiro; Hirawa, Shungo; Harada, Makoto; Okada, Tetsuo

    2010-06-01

    A coupled acoustic-gravity field is efficient for entrapping a particle at the position determined by its acoustic properties rather than its size. This field has been applied to the dynamic observation of ion-exchange reactions occurring in a single resin bead. The replacement of counterions in an ion-exchange resin induces changes in its acoustic properties, such as density and compressibility. Therefore, we can visually trace the advancement of an ion-exchange reaction as a time change in the levitation position of a resin bead entrapped in the field. Cation-exchange reactions occurring in resin beads with diameters of 40-120 microm are typically completed within 100-200 s. Ion-exchange equilibrium or kinetics is often evaluated with off-line chemical analyses, which require a batch amount of ion exchangers. Measurements with a single resin particle allow us to evaluate ion-exchange dynamics and kinetics of ions including those that are difficult to measure by usual off-line analyses. The diffusion properties of ions in resins have been successfully evaluated from the time change in the levitation positions of resin beads. PMID:20462180

  15. Scintillating 99Tc Selective Ion Exchange Resins

    SciTech Connect

    Mitchell Greenhalgh; Richard D. Tillotson

    2012-07-01

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

  16. Pyrolysis of Spent Ion Exchange Resins - 12210

    SciTech Connect

    Braehler, Georg; Slametschka, Rainer

    2012-07-01

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

  17. Waste treatment by selective mineral ion exchanger

    SciTech Connect

    Polito, Aurelie

    2007-07-01

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

  18. Proton/calcium ion exchange behavior of calcite.

    PubMed

    Villegas-Jiménez, Adrián; Mucci, Alfonso; Paquette, Jeanne

    2009-10-21

    The characterization of the proton sorptive properties of calcite in aqueous solutions at 25 +/- 1 degrees C over a relatively wide range of chemical conditions (7.16 ions is consistently observed, greatly exceeding the theoretical number of reactive surface sites. These observations are interpreted as a fast proton/calcium exchange equilibrium between the solution and "exchangeable cation sites" (e.g., lattice positions) at and/or beneath the calcite surface (species identified by "(exc)"), , that leads to a transient, "apparent" incongruent dissolution regime and the formation of a stable calcium-deficient, proton-enriched layer within the calcite lattice under circum-neutral and alkaline regimes at standard conditions. The 2H(+)/Ca(2+) ion exchange is quantitatively described by the Langmuir-power exchange function under the Vanselow convention: where n = 1 and log(10)K(ex) = 13.0 +/- 0.3. This calcite behavior, never reported before, masks surface equilibria and directly impacts the aqueous speciation of carbonate-rock systems with poor CO(2)(g) ventilation (e.g., aquifers, pore and deep sea waters, industrial reactors) via the buffering of pH and calcite dissolution. In contrast, at fixed pCO(2) conditions, aqueous speciation remains unaffected upon CO(2)(g) sequestration resulting from ion exchange-induced calcite precipitation: ([triple bond]CaCO3)2(exc) + CO2(g) + H2O <==> [triple bond]Ca(HCO3)2(exc) + CaCO3(s). Accordingly, reliable predictions of aqueous speciation in natural or engineered calcite-containing systems at variable pCO(2) conditions must consider this exchange reaction and the associated K(ex). The postulated proton/calcium exchange may have far

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

    SciTech Connect

    RAMSEY AA; THORSON MR

    2010-12-28

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

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

    SciTech Connect

    Ham, J.E.

    1996-01-04

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

  1. Ion exchange properties of novel hydrous metal oxide materials

    SciTech Connect

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

    1996-12-31

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

  2. Sorption of beryllium from fluorine-containing solutions by amino-phosphonate amphoteric ion-exchange resins

    SciTech Connect

    Pakholkov, V.S.; Rychkov, V.N.

    1981-10-20

    Sorption of beryllium ions by a series of amino-phosphonate amphoteric ion-exchange resins from BeF/sub 2/ solutions containing HF, NH/sub 4/F.HF, and NH/sub 4/F has been studied. The influence of the salt form of the resin, concentration of fluoride ions, and beryllium content in the original solutions was demonstrated. The mechanism of ion exchange on amphoteric ion-exchangers was postulated on the basis of chemical analysis and sorption and IR-spectroscopic data. Conclusions are drawn regarding the participation of phosphorus-containing groups of the resins in exchange. Data are presented on desorption of complex fluoride ions and beryllium from amphoteric ion-exchange resins by solutions of hydrofluoric, hydrochloric, and sulfuric acids, ammonium fluoride, and ammonium hydrogenfluoride.

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

    SciTech Connect

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

    2013-09-17

    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

  4. Small Column Ion Exchange Monitor System Final Report

    SciTech Connect

    CASELLA, VITO

    2004-09-30

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

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

    SciTech Connect

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

    1999-04-10

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

  6. Gadolinium-hydrogen ion exchange of zirconium phosphate

    NASA Technical Reports Server (NTRS)

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

    1972-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  8. Desalination by electrodialysis with the ion-exchange membrane prepared by radiation-induced graft polymerization

    NASA Astrophysics Data System (ADS)

    Choi, Seong-Ho; Han Jeong, Young; Jeong Ryoo, Jae; Lee, Kwang-Pill

    2001-01-01

    Ion-exchange membranes modified with the triethylamine [-N(CH 2CH 3) 3] and phosphoric acid (-PO 3 H) groups were prepared by radiation-induced grafting of glycidyl methacrylate (GMA) onto the polyolefin nonwavon fabric (PNF) and subsequent chemical modification of poly(GMA) graft chains. The physical and chemical properties of the GMA-grafted PNF and the PNF modified with ion-exchange groups were investigated by SEM, XPS, TGA, and DSC. Furthermore, electrochemical properties such as specific electric resistance, transport number of K +, and desalination were examined. The grafting yield increased with increasing reaction time and reaction temperature. The maximum grafting yield was obtained with 40% (vol.%) monomer concentration in dioxane at 60°C. The content of the cation- and anion-exchange group increased with increasing grafting yield. Electrical resistance of the PNF modified with TEA and -PO 3 H group decreased, while the water uptake (%) increased with increasing ion-exchange group capacities. Transport number of the PNF modified with ion-exchange group were the range of ca. 0.82-0.92. The graft-type ion-exchange membranes prepared by radiation-induced graft copolymerization were successfully applied as separators for electrodialysis.

  9. Ion exchange capacity of Nafion and Nafion composites

    SciTech Connect

    Chen, T.Y.; Leddy, J.

    2000-03-21

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

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

    SciTech Connect

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

    1998-09-01

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

  11. Tc-99 Ion Exchange Resin Testing

    SciTech Connect

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

    2010-08-01

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

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

    PubMed

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

    2016-01-01

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

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

    SciTech Connect

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

    2007-07-01

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

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

    DOEpatents

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

    1989-01-01

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

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

    SciTech Connect

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

    1995-03-01

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

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

    EPA Science Inventory

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

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

    ERIC Educational Resources Information Center

    Cornelius, Richard

    1980-01-01

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

  18. 21 CFR 173.25 - Ion-exchange resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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

  19. 21 CFR 173.25 - Ion-exchange resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

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

  20. 21 CFR 173.25 - Ion-exchange resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

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

  1. Semi-aerobic stabilized landfill leachate treatment by ion exchange resin: isotherm and kinetic study

    NASA Astrophysics Data System (ADS)

    Zamri, Mohd Faiz Muaz Ahmad; Kamaruddin, Mohamad Anuar; Yusoff, Mohd Suffian; Aziz, Hamidi Abdul; Foo, Keng Yuen

    2015-03-01

    This study was carried out to investigate the treatability of ion exchange resin (Indion MB 6 SR) for the removal of chromium (VI), aluminium (III), zinc (II), copper (II), iron (II), and phosphate (PO4)3-, chemical oxygen demand (COD), ammonia nitrogen (NH3-N) and colour from semi-aerobic stabilized leachate by batch test. A range of ion exchange resin dosage was tested towards the removal efficiency of leachate parameters. It was observed that equilibrium data were best represented by the Langmuir model for metal ions and Freundlich was ideally fit for COD, NH3-N and colour. Intra particle diffusion model, pseudo first-order and pseudo second-order isotherm models were found ideally fit with correlation of the experimental data. The findings revealed that the models could describe the ion exchange kinetic behaviour efficiently, which further suggests comprehensive outlook for the future research in this field.

  2. Ion-exchange sorption and preparative chromatography of biologically active materials

    SciTech Connect

    Samsonov, G.V.

    1986-01-01

    This book presents information on the following topics: the problems of fine physico-chemical biotechnology; types of highly permeable network polyelectrolytes; methods for studying the permeability and porosity of network polyelectrolytes; the conformation state and flexibility of the structural elements of network polyelectrolytes; ion-exchange processes without the sorption of physiologically active substances; ion exchange, hydration, and swelling; nucleosides, nucleotides, alkaloids, sulfonamides, and miscellaneous physiologically active subtances; sharp front formation for the exchange of ions with the same valences; standard quasi-equilibrium frontal chromatography on ionites; sorption kinetics in ionites with structural heterogeneity; experimental investigations of the diffusivities of organic and physiologically active ions in ionite beads; and increasing the efficiency of low-pressure chromatography by using surface-layer and bidispersed ionites.

  3. Anion selective membrane. [ion exchange resins and ion exchange membrane electrolytes for electrolytic cells

    NASA Technical Reports Server (NTRS)

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

    1975-01-01

    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.

  4. Partition Coefficients of Selected Compounds Using Ion Exchange Separation of Cesium From High Level Waste

    SciTech Connect

    Toth, James J.; Blanchard, David L.; Arm, Stuart T.; Urie, Michael W.

    2004-04-24

    The removal of cesium radioisotope (137Cs) from the High Level Waste stored in underground storage tanks at the Hanford site is a formidable chemical separations challenge for the Waste Treatment Plant. An eluatable organic-based ion exchange resin was selected as the baseline technology (1). The baseline technology design employs a proprietary macrocyclic weak-acid ion exchange resin to adsorb the cesium (137Cs) during the process loading cycle in a fixed bed column design. Following loading, the cesium is eluted from the resin using a nitric acid eluant. Previous work provided limited understanding of the performance of the resin, processed with actual wastes, and under multiple load and elute conditions, which are required for the ion exchange technology to be underpinned sufficiently for resolution of all process-related design issues before flowsheet and construction drawings can be released. By performing multiple ion exchange column tests with waste feeds, and measuring the chemical and radionuclide compositions of the waste feeds, column effluents and column eluants, ion exchange stream composition information can be provided for supporting resolution of selected design issues.

  5. Exchange-coupled nanocomposites: chemical synthesis, characterization and applications.

    PubMed

    Liu, Fei; Hou, Yanglong; Gao, Song

    2014-12-01

    Nanocomposites containing soft and hard magnetic phases have attracted immense attention for energy-related and biomedical applications. With exchange coupling between nanoscale grains in the composites, magnetization of the soft magnetic phase can rotate coherently with that of the hard magnetic phase. In particular, good control of the soft and hard phases at the nanoscale in the composites is of great importance for effective exchange coupling, allowing us to make the best of the strengths of soft and hard magnetic phases and to optimize the magnetic properties for targeted applications. In this review, we present the recent progress in the chemical synthesis and applications of exchange-coupled nanocomposites. Firstly, the principle of nanomagnetism and exchange coupling is introduced. Secondly, the characterization of exchange-coupled nanocomposites is summarized. Thirdly, the chemical methods for the production of different exchange-coupled nanocomposites are presented. Finally, applications of exchange-coupled nanocomposites in magnetic energy storage and biomedicine are addressed. PMID:25130706

  6. Updating of sewage - purification facilities of electroplating enterprises with counterflow ion-exchange filters

    NASA Astrophysics Data System (ADS)

    Torosyan, V. F.; Torosyan, E. S.; Sorokin, P. D.; Telitsyn, A. A.

    2015-09-01

    The paper focuses on work of electroplating sewage-purification facilities of mechanical engineering production; drawbacks caused by specific features of physical and chemical processes of coagulation and technological malfunctions have been revealed. Additional equipment - ion-exchanging filters have been selected on the basis of designed methods, they make it possible for enterprises of mechanical engineering to implement conversion to water rotation systems.

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

    PubMed

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

    2014-03-01

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

  8. Ion momentum and energy transfer rates for charge exchange collisions

    NASA Technical Reports Server (NTRS)

    Horwitz, J.; Banks, P. M.

    1973-01-01

    The rates of momentum and energy transfer have been obtained for charge exchange collisions between ion and neutral gases having arbitrary Maxwellian temperatures and bulk transport velocities. The results are directly applicable to the F-region of the ionosphere where 0+ - 0 charge is the dominant mechanism affecting ion momentum and energy transfer.

  9. ELUTION OF URANIUM VALUES FROM ION EXCHANGE RESINS

    DOEpatents

    Kennedy, R.H.

    1959-11-24

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

  10. Desalination of brackish waters using ion-exchange media

    SciTech Connect

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

    2006-06-21

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

  11. Desalination of brackish waters using ion exchange media.

    SciTech Connect

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

    2005-01-01

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

  12. Microsecond pulsed hydrogen/deuterium exchange of electrosprayed ubiquitin ions stored in a linear ion trap.

    PubMed

    Rajabi, Khadijeh

    2015-02-01

    A pulse of D2O vapour on the order of microseconds is allowed to react with the +6 to +9 charge states of ubiquitin confined in a linear ion trap (LIT). Two envelopes of peaks are detected for the ions of ubiquitin, corresponding to the ions that exchange more quickly and more slowly. The deuterium uptake of the protonated sites on ubiquitin ions accounts for the ion population with the fast exchange. The hydrogen/deuterium exchange (HDX) kinetics of ubiquitin ions trapped in the LIT for 200 ms showed comparable structural transitions to those trapped for 300 ms. When ions are trapped for longer, i.e. up to 2000 ms, mainly the slow exchanging ion population is detected. In all experiments the +7 ions exchange the most, suggesting a short distance between the surface protonated sites and nearby charged sites, and concomitantly high accessibility of surface protonated sites towards D2O. The +6 ions are more compact than the +7 ions but have one fewer protonated site, therefore fewer surface availabilities for D2O attack. The data suggest that the +6 ions keep most of their solution-phase contacts intact while the hydrophobic core is slightly interrupted in the +7 ions, possibly due to the exposure of charged His68 that is normally buried in the hydrophobic pocket. The +8 and +9 ions have more protonated sites but are less compact than the +7 ions because of Coulombic repulsion, resulting in a larger distance between the protonated sites and the basic sites. The data indicate that the HDX mechanism of ions with the slower exchange corresponding to the second envelope of peaks is primarily governed via a relay mechanism. The results suggest that the pulsed HDX MS method is sampling a population of ubiquitin ions with a similar backbone fold to the solution. PMID:25553956

  13. Quantitative ion-exchange separation of plutonium from impurities

    SciTech Connect

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

    1981-09-01

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

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

    SciTech Connect

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

    2004-12-01

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

  15. Ligand-exchange chromatography of aromatic amines on resin-bound cobalt ion

    SciTech Connect

    Pehlivan, E.; Vural, U.S.; Ayar, A.; Yildiz, S.

    1996-06-01

    The use of cobalt metal for the selective separation of aromatic amines is completed with a chemically bonded diamine and glyoxime functional groups onto Lycopodium clavatum. Oximes and amines are excellent complexing agents for transition metal ions. Cobalt(II) metal ions can easily be immobilized on bis-diaminoethyl-glyoximated sporopollenin (bDAEG-sporopollenin). The ligand-exchange behavior of modified Lycopodium clavatum with respect to aromatic amines was investigated. This will permit the evaluation of bDAEG-sporopollenin ligand exchangers for their utilization as sorbents in the recovery, pollution control, and elimination of amines from wastewater.

  16. Fractionation of Aspergillus niger cellulases by combined ion exchange affinity chromatography

    SciTech Connect

    Boyer, R.F.; Allen, T.L.; Dykema, P.A.

    1987-02-05

    Eight chemically modified cellulose supports were tested for their ability to adsorb components of the Aspergillus niger cellulase system. At least two of the most effective adsorbents, aminoethyl cellulose and carboxymethyl cellulose, were shown to be useful for the fractionation of cellulases. These supports apparently owe their resolving capacity to both ion exchange and biospecific binding effects; however, the relative importance of each effect is unknown. These observations form the basis for a new cellulase fractionation technique, combined ion exchange-affinity chromatography. 22 references.

  17. Determining Clumped Isotope (Δ47) Signatures of CO2 During Ion-Molecule Isotopic Exchange Reactions

    NASA Astrophysics Data System (ADS)

    Sarna, J.; Priyadarshi, A.; Pourmorady, P.; Tripati, A.; Estaris, J.

    2015-12-01

    The abundance of multiply-substituted isotopologues such as 13C16O18O can be used to understand fundamental mechanisms that controls isotopic fractionation in chemical reactions. Knowledge of the energy-dependent ion-molecule isotopic exchange rate for 13C16O18O may also provide important insights into the CO2 ion-molecular exchange that occurs in the source of the mass spectrometer. It may offer an explanation for the recently observed nonlinearities associated with clumped isotope measurements. We designed a controlled set of laboratory experiments to investigate variations in the abundance of 13C16O18O associated with different ion-molecular isotopic exchange reactions. In our experiments, we characterize the effects of changing ionization energy, reaction time, CO2 amount, the presence of different compounds, and reaction chamber temperature on the clumped isotopic composition of CO2.

  18. Ion exchange polymers for anion separations

    DOEpatents

    Jarvinen, Gordon D.; Marsh, S. Fredric; Bartsch, Richard A.

    1997-01-01

    Anion exchange resins including at least two positively charged sites and a ell-defined spacing between the positive sites are provided together with a process of removing anions or anionic metal complexes from aqueous solutions by use of such resins. The resins can be substituted poly(vinylpyridine) and substituted polystyrene.

  19. Ion exchange polymers for anion separations

    DOEpatents

    Jarvinen, G.D.; Marsh, S.F.; Bartsch, R.A.

    1997-09-23

    Anion exchange resins including at least two positively charged sites and a well-defined spacing between the positive sites are provided together with a process of removing anions or anionic metal complexes from aqueous solutions by use of such resins. The resins can be substituted poly(vinylpyridine) and substituted polystyrene.

  20. THERMODYNAMICS OF ION-EXCHANGED NATURAL CLINOPTILOLITE

    EPA Science Inventory

    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...

  1. Hydrous oxide ion-exchange compound catalysts

    DOEpatents

    Dosch, Robert G.; Stephens, Howard P.

    1990-01-01

    A catalytic material of improved activity which comprises a hydrous, alkali metal or alkaline earth metal or quaternary ammonium titanate, zirconate, niobate, or tantalate, in which the metal or ammonium cations have been exchange with a catalytically effective quantity of a catalyst metal, and which has been subsequently treated with a solution of a Bronsted acid.

  2. Properties of a Novel Ion-Exchange Film

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

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

  3. Properties of a Novel Ion-Exchange Film

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

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

  4. Catalysis using hydrous metal oxide ion exchanges

    DOEpatents

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

    1985-01-01

    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.

  5. Catalysis using hydrous metal oxide ion exchangers

    DOEpatents

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

    1983-07-21

    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.

  6. Recovery of boric acid from ion exchangers

    DOEpatents

    Pollock, Charles W.

    1976-01-01

    The recovery of boric acid from an anion exchange resin is improved by eluting the boric acid with an aqueous solution of ammonium bicarbonate. The boric acid can be readily purified and concentrated by distilling off the water and ammonium bicarbonate. This process is especially useful for the recovery of boric acid containing a high percentage of .sup.10 B which may be found in some nuclear reactor coolant solutions.

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

    SciTech Connect

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

    1985-11-01

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

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

    NASA Technical Reports Server (NTRS)

    Smith, J. K.

    1975-01-01

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

  9. Charge-exchange plasma generated by an ion thruster

    NASA Technical Reports Server (NTRS)

    Kaufman, H. R.

    1977-01-01

    The charge exchange plasma generated by an ion thruster was investigated experimentally using both 5 cm and 15 cm thrusters. Results are shown for wide ranges of radial distance from the thruster and angle from the beam direction. Considerations of test environment, as well as distance from the thruster, indicate that a valid simulation of a thruster on a spacecraft was obtained. A calculation procedure and a sample calculation of charge exchange plasma density and saturation electron current density are included.

  10. Synthesis and characterization of a novel hybrid nano composite cation exchanger poly-o-toluidine Sn(IV) tungstate: Its analytical applications as ion-selective electrode

    NASA Astrophysics Data System (ADS)

    Khan, Asif Ali; Shaheen, Shakeeba

    2013-02-01

    A novel organic-inorganic nano composite cation exchanger poly-o-toluidine Sn(IV) tungstate has been synthesized by incorporation of a polymer material into inorganic precipitate. The material is a class of hybrid ion-exchanger with good ion-exchange properties, reproducibility, stability and good selectivity for heavy metals. The physico-chemical properties of this nano composite material were characterized by using XRD, TGA, FTIR, SEM and TEM. The ion-exchange capacity, pH titrations, elution behavior and chemical stability were also carried out to study ion-exchange properties of the material. Distribution studies for various metal ions revealed that the nano composite is highly selective for Cd(II). An ion-selective membrane electrode was fabricated using this material for the determination of Cd(II) ions in solutions. The analytical utility of this electrode was established by employing it as an indicator electrode in electrometric titrations.

  11. Rupture loop annex ion exchange RLAIX vault deactivation

    SciTech Connect

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

    1996-08-01

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

  12. Electrodialytic separation of alkali-element ions with the aid of ion-exchange membranes

    SciTech Connect

    Gurskii, V.S.; Moskvin, L.N.

    1988-03-20

    Electrodialytic separation of ions bearing charges of the same sign with the aid of ion-exchange membranes has been examined in the literature in relation to the so-called ideal membranes, which do not exhibit selectivity with respect to one ion type in ion exchange. It has been shown that separation on such membranes is effective only for counterions differing in size of charge. A matter of greater importance from the practical standpoint is the possibility of using electrodialysis for separating ions bearing like charges and having similar properties, including ionic forms of isotopes of the same element. In this paper they report a comparative study of ion separation, with reference to the Cs-Na pair, by electrodialysis through various types of cation-exchange membranes. Changes of the solution concentration in the cathode compartment were monitored by measurement of /sup 22/Na and /sup 137/Cs activities.

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

    NASA Technical Reports Server (NTRS)

    Rembaum, A. (Inventor)

    1977-01-01

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

  14. Alkaline Anion-Exchange Membranes Containing Mobile Ion Shuttles.

    PubMed

    Ge, Xiaolin; He, Yubin; Guiver, Michael D; Wu, Liang; Ran, Jin; Yang, Zhengjin; Xu, Tongwen

    2016-05-01

    A new class of alkaline anion-exchange membranes containing mobile ion shuttles is developed. It is achieved by threading ionic linear guests into poly(crown ether) hosts via host-guest molecular interaction. The thermal- and pH-triggered shuttling of ionic linear guests remarkably increases the solvation-shell fluctuations in inactive hydrated hydroxide ion complexes (OH(-) (H2 O)4 ) and accelerates the OH(-) transport. PMID:26972938

  15. Synthesis, Characterization and Ion Exchange of New Na/Nb/M(4+)/O/H(2)O(M=Ti,Zr) Phases

    SciTech Connect

    Nenoff, Tina M.; Nyman, May

    1999-05-07

    Due to the vast diversity of chemical media in which metal separations are executed, a wide range of ion separation materials are employed. This results in an ongoing effort to discover new phases with novel ion exchange properties. We present here the synthesis of a novel class of thermally and chemically stable microporous, niobate-based materials. Ion exchange studies show these new phases are highly selective for Sr2+ and other bivalent metals.

  16. Ion Exchange Resin and Clay Vitrification by Plasma Discharges

    NASA Astrophysics Data System (ADS)

    Díaz A., Laura V.; Pacheco S., Joel O.; Pacheco P., Marquidia; Monroy G., Fabiola; Emeterio H., Miguel; Ramos F., Fidel

    2006-12-01

    The lack of treatment of a low and intermediate level radioactive waste (LILRW) lead us to propose a vitrification process based on a plasma discharge; this technique incorporates LILRW into a matrix glass composed of ceramic clays material. The Mexican Institute of Nuclear Research (ININ), uses an ion exchange resin IRN 150 (styrene-divinilbence copolymer) in the TRIGA MARK III nuclear reactor. The principal objective of this resin is to absorb particles containing heavy metals and low-level radioactive particles. Once the IRN 150 resin filter capacity has been exceeded, it should be replaced and treated as LILRW. In this work, a transferred plasma system was realized to vitrify this resin taking advantage of its high power density, enthalpy and chemical reactivity as well as its rapid quenching and high operation temperatures. In order to characterize the morphological structure of these clay samples, Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and Thermogravimetric analysis (TGA) techniques were applied before and after the plasma treatment.

  17. Ion Exchange Resin and Clay Vitrification by Plasma Discharges

    SciTech Connect

    Diaz A, Laura V.

    2006-12-04

    The lack of treatment of a low and intermediate level radioactive waste (LILRW) lead us to propose a vitrification process based on a plasma discharge; this technique incorporates LILRW into a matrix glass composed of ceramic clays material. The Mexican Institute of Nuclear Research (ININ), uses an ion exchange resin IRN 150 (styrene-divinilbence copolymer) in the TRIGA MARK III nuclear reactor. The principal objective of this resin is to absorb particles containing heavy metals and low-level radioactive particles. Once the IRN 150 resin filter capacity has been exceeded, it should be replaced and treated as LILRW. In this work, a transferred plasma system was realized to vitrify this resin taking advantage of its high power density, enthalpy and chemical reactivity as well as its rapid quenching and high operation temperatures. In order to characterize the morphological structure of these clay samples, Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and Thermogravimetric analysis (TGA) techniques were applied before and after the plasma treatment.

  18. Studies of negative ions by collision-induced decomposition and hydrogen-deuterium exchange techniques.

    PubMed Central

    Hunt, D F; Sethi, S K; Shabanowitz, J

    1980-01-01

    Development of two new techniques for studying the gas phase chemistry of negative ions is reported. Collision induced dissociation (CID) of (M-1)- ions has been accomplished in a newly constructed triple stage quadrupole mass spectrometer. This instrument was assembled by adding two additional Finnigan quadrupole mass filters to a Finnigan Model 3200 CI mass spectrometer. Generation of (M-1)- ions is accomplished by allowing OH- and sample to react under CI conditions in the ion source. The first quadrupole mass filter, Q1, is then employed to selectively pass the (M-1)- ion into a second quadrupole filter containing argon or neon at 10(-3) torr. On collision with the inert gas the (M-1)- ions dissociate into fragments which are then mass analyzed in the third quadrupole filter, CID spectra of (M-1)- ions from twelve carbonyl compounds are presented in this paper. Ion molecule isotope exchange reactions in the CI ion source can be used to count the number of hydrogen atoms in many different chemical environments. Collisions between sample (M-1)- ions and deuterium-labeled reagent gases (ND3, D2O, EtOD) facilitate incorporation of deuterium into the negative ion if the basicities of the sample and reagent anions are similar. Thus it is possible to selectively incorporate deuterium into many organic samples by controlling the exothermicity of the acid base, ion-molecule chemistry. PMID:7428745

  19. Optimal sampling schedule for chemical exchange saturation transfer.

    PubMed

    Tee, Y K; Khrapitchev, A A; Sibson, N R; Payne, S J; Chappell, M A

    2013-11-01

    The sampling schedule for chemical exchange saturation transfer imaging is normally uniformly distributed across the saturation frequency offsets. When this kind of evenly distributed sampling schedule is used to quantify the chemical exchange saturation transfer effect using model-based analysis, some of the collected data are minimally informative to the parameters of interest. For example, changes in labile proton exchange rate and concentration mainly affect the magnetization near the resonance frequency of the labile pool. In this study, an optimal sampling schedule was designed for a more accurate quantification of amine proton exchange rate and concentration, and water center frequency shift based on an algorithm previously applied to magnetization transfer and arterial spin labeling. The resulting optimal sampling schedule samples repeatedly around the resonance frequency of the amine pool and also near to the water resonance to maximize the information present within the data for quantitative model-based analysis. Simulation and experimental results on tissue-like phantoms showed that greater accuracy and precision (>30% and >46%, respectively, for some cases) were achieved in the parameters of interest when using optimal sampling schedule compared with evenly distributed sampling schedule. Hence, the proposed optimal sampling schedule could replace evenly distributed sampling schedule in chemical exchange saturation transfer imaging to improve the quantification of the chemical exchange saturation transfer effect and parameter estimation. PMID:23315799

  20. Microspheres aided introduction of ionophore and ion-exchanger to the ion-selective membrane.

    PubMed

    Wojciechowski, Marcin; Kisiel, Anna; Bulska, Ewa; Michalska, Agata

    2012-01-15

    In this work a novel method for introduction of ionophore and ion-exchanger to the ion-selective polyacrylate based membrane is proposed. These compounds (and optionally primary ions) are introduced to polyacrylate microspheres, used to prepare ion-selective membrane. The approach proposed here can be used to prepare membranes containing primary ions equally distributed through the receptor phase, i.e. membranes that do not require conditioning in primary ions solution and are free from problems related to slow diffusion of primary ions. Thus obtained sensors were characterized with linear responses (also at relatively high activities) and high selectivities, despite considerable reduction of ionophore and ion-exchanger amount introduced to the membrane. To be able to prepare ion-selective membranes using this approach, a method for quantification of ionophore and ion-exchanger introduced into microspheres is required. In this work a novel method utilizing high performance liquid chromatography (HPLC) with DAD or FLD detection is proposed. Incorporation of ionophore and ion-exchanger into the microspheres was achieved either by absorption into ready spheres or in course of photopolymerization of polymeric beads. The obtained results have proven that both procedures led to incorporation of ionophore/ion-exchanger into polymeric spheres, however, the content of the compounds in the spheres post process is different from their ratio in solution from which they had been introduced. These effects need to be considered/compensated while preparing microspheres containing ion-selective membranes. As a model system poly(n-butyl acrylate) spheres, silver selective ionophore and sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate were chosen, resulting ultimately in silver-selective electrodes. PMID:22265471

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

    PubMed

    Geise, Geoffrey M; Cassady, Harrison J; Paul, Donald R; Logan, Bruce E; Hickner, Michael A

    2014-10-21

    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 charge density and polarizability

  2. ATPases, ion exchangers and human sperm motility.

    PubMed

    Peralta-Arias, Rubén D; Vívenes, Carmen Y; Camejo, María I; Piñero, Sandy; Proverbio, Teresa; Martínez, Elizabeth; Marín, Reinaldo; Proverbio, Fulgencio

    2015-05-01

    Human sperm has several mechanisms to control its ionic milieu, such as the Na,K-ATPase (NKA), the Ca-ATPase of the plasma membrane (PMCA), the Na(+)/Ca(2) (+)-exchanger (NCX) and the Na(+)/H(+)-exchanger (NHE). On the other hand, the dynein-ATPase is the intracellular motor for sperm motility. In this work, we evaluated NKA, PMCA, NHE, NCX and dynein-ATPase activities in human sperm and investigated their correlation with sperm motility. Sperm motility was measured by Computer Assisted Semen Analysis. It was found that the NKA activity is inhibited by ouabain with two Ki (7.9 × 10(-9) and 9.8 × 10(-5) M), which is consistent with the presence of two isoforms of α subunit of the NKA in the sperm plasma membranes (α1 and α4), being α4 more sensitive to ouabain. The decrease in NKA activity is associated with a reduction in sperm motility. In addition, sperm motility was evaluated in the presence of known inhibitors of NHE, PMCA and NCX, such as amiloride, eosin, and KB-R7943, respectively, as well as in the presence of nigericin after incubation with ouabain. Amiloride, eosin and KB-R7943 significantly reduced sperm motility. Nigericin reversed the effect of ouabain and amiloride on sperm motility. Dynein-ATPase activity was inhibited by acidic pH and micromolar concentrations of Ca(2) (+). We explain our results in terms of inhibition of the dynein-ATPase in the presence of higher cytosolic H(+) and Ca(2) (+), and therefore inhibition of sperm motility. PMID:25820902

  3. PbSe films by ion exchange of synthetic plumbonacrite layers immersed in a selenium ionic solution

    NASA Astrophysics Data System (ADS)

    Mendívil-Reynoso, T.; Ochoa-Landín, R.; Ramírez-Rodríguez, L. P.; Gutierrez-Acosta, K.; Ramírez-Bon, R.; Castillo, S. J.

    2016-06-01

    Plumbonacrite is a lead compound with chemical formula Pb10(CO3)6(OH)6O, where several groups can be substituted by ion exchange in mild conditions. Plumbonacrite layers can be deposited by means of the chemical bath deposition technique. In this work it is studied the structural and morphological evolution of a plumbonacrite layer as a function of the immersion time in an aqueous solution containing Se-2 ions. The 1.39 μm thick plumbonacrite layer was chemically deposited on a glass substrate and immersed in an aqueous solution with Se-2 ions for 10, 20, 30 and 50 min. The as grown plumbonacrite layer as well as the immersed ones were analyzed by X-rays Diffraction, Scanning Electron Microscopy and Raman Spectroscopy measurements. The results show that the plumbonacrite layer is gradually converted to PbSe one by ion exchange process, where Se-2 ions substitute the groups of plumbonacrite.

  4. EVALUATING ION EXCHANGE FOR REMOVING RADIUM FROM GROUNDWATER

    EPA Science Inventory

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

  5. DEVELOPMENT OF INORGANIC ION EXCHANGERS FOR NUCLEAR WASTE REMEDIATION

    EPA Science Inventory

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

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

    DOEpatents

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

    2002-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    1996-08-01

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

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

    SciTech Connect

    Oji, L.N.

    1999-02-17

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

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

    SciTech Connect

    Adu-Wusu, K.

    2003-12-22

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

  10. SELENIUM REMOVAL FROM DRINKING WATER BY ION EXCHANGE

    EPA Science Inventory

    Strong-base anion exchangers were shown to remove selenate and selenite ions from drinking water. Because selenium species are usually present at low concentrations, the efficiency of removal is controlled by the concentration of the common drinking water anions, the most importa...

  11. Determination of boron in silicates after ion exchange separation

    USGS Publications Warehouse

    Kramer, H.

    1955-01-01

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

  12. Ion exchange in a zeolite-molten chloride system

    SciTech Connect

    Woodman, R.H.; Pereira, C.

    1997-07-01

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

  13. Thermal Analysis for Ion-Exchange Column System

    SciTech Connect

    Lee, Si Y.; King, William D.

    2012-12-20

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

  14. ION-EXCHANGE PROCESSES AND MECHANISMS IN GLASSES

    EPA Science Inventory

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

  15. EVALUATING ION EXCHANGE FOR REMOVING RADIUM FROM GROUNDWATER

    EPA Science Inventory

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

  16. Planar Waveguides Formed by Ag Na Ion Exchange in Nonlinear Optical Glasses: Diffusion and Optical Properties

    NASA Astrophysics Data System (ADS)

    Martin, Marc; Videau, Jean J.; Canioni, Lionel; Adamietz, Frédéric; Sarger, Laurent; Le Flem, Gilles

    2000-01-01

    All-optical communication systems are the subject of intense research related to the integration of nonlinear optical materials. In sodiocalcic borophosphate glasses that contain niobium oxide and exhibit high nonlinear optical indices, planar waveguides have been formed by a Ag Na ion-exchange technique. WKB analysis has been used to characterize the diffusion profiles of silver ions exchanged in glass substrate samples chemically by an electron microprobe technique and optically by an M -line technique. These methods permit the Ag penetration depth and diffusion profile shape and index profiles to be determined. The results are analyzed and discussed in relation to Ca 2 concentration and exchange conditions in glasses. The Ag diffusion in these glasses can be almost entirely controlled for index-profile engineering.

  17. Water exchange dynamics around H3O+ and OH- ions

    NASA Astrophysics Data System (ADS)

    Roy, Santanu; Dang, Liem X.

    2015-05-01

    In this letter, we report the first computer simulation of the dynamics of water exchanging between the first and second solvation shells of H3O+. Employing different rate theories for chemical reactions such as the transition state theory, the Grote-Hynes theory, the reactive flux method, and the Impey-Madden-McDonald method, we calculate the solvent exchange rates from molecular dynamics simulations that account for explicit polarization effects. In addition, we also study water exchanges around OH- and find that the corresponding time scale is much smaller than that for H3O+.

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

    PubMed

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

    2012-08-21

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

  19. Graphene/Ionic Liquid Composite Films and Ion Exchange

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2014-01-01

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

  1. Graphene/Ionic Liquid Composite Films and Ion Exchange

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

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

  2. Radon (222Rn) in ground water of fractured rocks: A diffusion/ion exchange model

    USGS Publications Warehouse

    Wood, W.W.; Kraemer, T.F.; Shapiro, A.

    2004-01-01

    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.

  3. Radon (222Rn) in ground water of fractured rocks: a diffusion/ion exchange model.

    PubMed

    Wood, Warren W; Kraemer, Thomas F; Shapiro, Allen

    2004-01-01

    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 degrees 56'N, 71 degrees 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. PMID:15318778

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

    PubMed

    Duong-Ly, Krisna C; Gabelli, Sandra B

    2014-01-01

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

  5. Effect of Mono- and Poly-CH/P Exchange(s) on the Aromaticity of the Tropylium Ion.

    PubMed

    Puri, Ankita; Gupta, Raakhi

    2016-01-01

    In view of the fact that the phosphorus atom in its low co-ordination state (coordination numbers 1 and 2) has been termed as the carbon copy, there have been attempts to investigate, theoretically as well as experimentally, the effect of the exchange(s) of CH- moiety with phosphorus atom(s) (CH/P) on the structural and other aspects of the classical carbocyclic and heterocyclic systems. Tropylium ion is a well-known non-benzenoid aromatic system and has been studied extensively for its aromatic character. We have now investigated the effect of mono- and poly-CH/P exchange(s) on the aromaticity of the tropylium ion. For this purpose, the parameters based on the geometry and magnetic properties, namely bond equalization, aromatic stabilization energies (ASE), Nucleus-Independent Chemical Shift (NICS) values, (NICS(0), NICS(1), NICS(1)zz), proton nucleus magnetic resonance (¹H-NMR) chemical shifts, magnetic susceptibility exaltation and magnetic anisotropic values of mono-, di-, tri- and tetra-phosphatropylium ions have been determined at the Density Functional Theory (DFT) (B3LYP/6-31+G(d)) level. Geometry optimization reveals bond length equalization. ASEs range from -46.3 kcal/mol to -6.2 kcal/mol in mono- and diphospha-analogues which are planar. However, the ions having three and four phosphorus atoms lose planarity and their ASE values approach the values typical for non-aromatic structures. Of the three NICS values, the NICS(1)zz is consistently negative showing aromatic character of all the systems studied. It is also supported by the magnetic susceptibility exaltations and magnetic anisotropic values. Furthermore, ¹H-NMR chemical shifts also fall in the aromatic region. The conclusion that mono-, di-, tri- and tetra-phosphatropylium ions are aromatic in nature has been further corroborated by determining the energy gap between the Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) (HOMO - LUMO gap), which falls in the

  6. Electrosorptive desalination by carbon nanotubes and nanofibres electrodes and ion-exchange membranes.

    PubMed

    Li, Haibo; Gao, Yang; Pan, Likun; Zhang, Yanping; Chen, Yiwei; Sun, Zhuo

    2008-12-01

    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. PMID:18929385

  7. Single Motional Quantum Exchange between Independently Trapped Ions

    NASA Astrophysics Data System (ADS)

    Brown, K. R.; Ospelkaus, C.; Colombe, Y.; Wilson, A. C.; Leibfried, D.; Wineland, D. J.

    2011-05-01

    The Coulomb coupling of ions in separate potential wells is a key feature of proposals to implement quantum simulation and could enable logic operations to be performed in a multi-zone quantum information processor without the requirement of bringing the ion qubits into the same trapping potential. It might also extend the capabilities of quantum logic spectroscopy to ions that cannot be trapped in the same potential well as the measurement ion, such as oppositely charged ions or even antimatter particles. We report recent results demonstrating tunable coupling of two 9Be+ ions held in trapping potentials separated by 40 μm. The ions are trapped 40 μm above the surface of a microfabricated planar trap with independently tunable axial frequencies of ~4 MHz. The trap is cooled to 4.2 K with a helium bath cryostat to suppress anomalous heating and to extend the lifetime of ions from minutes to days. By preparing approximate motional number states with n=0 and n=1 in the respective wells, and tuning the confining wells into resonance, a single quantum of motion is exchanged between the ions in ~200 μs. Work supported by IARPA, DARPA, ONR, and the NIST Quantum Information Program.

  8. Ion exchange selectivity for cross-linked polyacrylic acid

    NASA Technical Reports Server (NTRS)

    May, C. E.; Philipp, W. H.

    1983-01-01

    The ion separation factors for 21 common metal ions with cross-linked polyacrylic acid were determined as a function of pH and the percent of the cross-linked polyacrylic acid neutralized. The calcium ion was used as a reference. At a pH of 5 the decreasing order of affinity of the ions for the cross-linked polyacrylic acid was found to be: Hg++, Fe+++, Pb++, Cr+++, Cu++, Cd++, Al+++, Ag+, Zn++, Ni++, Mn++, Co++, Ca++, Sr++, Ba++, Mg++, K+, Rb+, Cs+, Na+, and Li+. Members of a chemical family exhibited similar selectivities. The Hg++ ion appeared to be about a million times more strongly bound than the alkali metal ions. The relative binding of most of the metal ions varied with pH; the very tightly and very weakly bound ions showed the largest variations with pH. The calcium ion-hydrogen ion equilibrium was perturbed very little by the presence of the other ions. The separation factors and selectivity coefficients are discussed in terms of equilibrium and thermodynamic significance.

  9. Mechanism of extracellular ion exchange and binding-site occlusion in a sodium/calcium exchanger.

    PubMed

    Liao, Jun; Marinelli, Fabrizio; Lee, Changkeun; Huang, Yihe; Faraldo-Gómez, José D; Jiang, Youxing

    2016-06-01

    Na(+)/Ca(2+) exchangers use the Na(+) electrochemical gradient across the plasma membrane to extrude intracellular Ca(2+) and play a central role in Ca(2+) homeostasis. Here, we elucidate their mechanisms of extracellular ion recognition and exchange through a structural analysis of the exchanger from Methanococcus jannaschii (NCX_Mj) bound to Na(+), Ca(2+) or Sr(2+) in various occupancies and in an apo state. This analysis defines the binding mode and relative affinity of these ions, establishes the structural basis for the anticipated 3:1 Na(+)/Ca(2+)-exchange stoichiometry and reveals the conformational changes at the onset of the alternating-access transport mechanism. An independent analysis of the dynamics and conformational free-energy landscape of NCX_Mj in different ion-occupancy states, based on enhanced-sampling molecular dynamics simulations, demonstrates that the crystal structures reflect mechanistically relevant, interconverting conformations. These calculations also reveal the mechanism by which the outward-to-inward transition is controlled by the ion occupancy, thereby explaining the emergence of strictly coupled Na(+)/Ca(2+) antiport. PMID:27183196

  10. Exploring the favorable ion-exchange ability of phthalylated cellulose biopolymer using thermodynamic data.

    PubMed

    de Melo, Júlio C P; da Silva Filho, Edson C; Santana, Sirlane A A; Airoldi, Claudio

    2010-09-01

    A phthalylated ion-exchange biopolymer was obtained by adding cellulose to molten phthalic anhydride in a quasi solvent-free procedure. Through this route 2.99+/-0.07 mmolg(-1) of pendant groups containing ester and carboxylic acid moieties were incorporated into the polymeric structure that was characterized by elemental analysis, solid-state carbon nuclear magnetic resonance (CP/MAS), infrared spectroscopy, X-ray diffraction, and thermogravimetry. The chemically modified polysaccharide is able to exchange cations from aqueous solution as demonstrated by batchwise methodology. The data were adjusted to a modified Langmuir equation to give 2.43+/-0.12 and 2.26+/-0.11 mmolg(-1) for divalent cobalt and nickel cations, respectively. The net thermal effects obtained from calorimetric titration measurements were also adjusted to a modified Langmuir equation, and the enthalpy of the interaction was calculated to give endothermic values of 2.11+/-0.28 and 2.50+/-0.31kJmol(-1) for these cations, respectively. The spontaneity of this ion-exchange process is reflected in negative Gibbs energy and with a contribution of positive entropic values. This set of thermodynamic data at the solid-liquid interface suggests a favorable ion-exchange process for this anchored biopolymer for cation exchange from the environment. PMID:20673881

  11. Highly sensitive determination of hydrazine ion by ion-exclusion chromatography with ion-exchange enhancement of conductivity detection.

    PubMed

    Mori, Masanobu; Tanaka, Kazuhiko; Xu, Qun; Ikedo, Mikaru; Taoda, Hiroshi; Hu, Wenzhi

    2004-06-11

    An ion-exclusion chromatography method with ion-exchange enhancement of conductivity was developed for the selective separation and sensitive determination of hydrazine ion from alkali/alkaline earth metal cations and ammonium ion. Hydrazine ion was separated by ion-exclusion/penetration effect from other cations on a weakly basic anion-exchange column in the OH- form (TSKgel DEAE-5PW). Moreover, two different ion-exchange resin columns were inserted between the separating column and conductimetric detector in order to improve the sensitivity of hydrazine ion. The first enhancement column packed with a strongly basic anion-exchange resin in the SO4(2-) form (TSKgel SAX) for hydrazine ion can convert from N2H5OH to (N2H5)2SO4. Moreover, the second enhancement column packed with a strongly acidic cation-change resin in the H+ form (TSKgel SCX) can convert to H2SO4. As a result, the sensitivity of hydrazine ion using two conductivity enhancement columns could be 26.8-times greater than using the separating column alone. This method was effectiveness also for the enhancement of ammonium ion (6.1-times) and sodium ion (1.2-times). The calibration graph of hydrazine ion detected as H2SO4 was linear over the concentration range of 0.001-100 ppm (r2 = 0.9988). The detection limit of hydrazine ion in this system was 0.64 ppb. Therefore, hydrazine ion in real boiler water sample could be accurately determined, avoiding the interference of other cations. PMID:15250415

  12. Ion exchange and surface charge on montmorillonite clay

    SciTech Connect

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

    1999-05-01

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

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

    SciTech Connect

    Norato, M.A.

    2000-12-19

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

  14. Synthesis, structural characterization, and performance evaluation of resorcinol-formaldehyde (R-F) ion-exchange resin

    SciTech Connect

    Hubler, T.L.; Franz, J.A.; Shaw, W.J.; Bryan, S.A.; Hallen, R.T.; Brown, G.N.; Bray, L.A.; Linehan, J.C.

    1995-08-01

    The 177 underground storage tanks at the DOE`s Hanford Site contain an estimated 180 million tons of high-level radioactive wastes. It is desirable to remove and concentrate the highly radioactive fraction of the tank wastes for vitrification. Resorcinol-formaldehyde (R-F) resin, an organic ion-exchange resin with high selectivity and capacity for the cesium ion, which is a candidate ion-exchange material for use in remediation of tank wastes. The report includes information on the structure/function analysis of R-F resin and the synthetic factors that affect performance of the resin. CS-100, a commercially available phenol-formaldehyde (P-F) resin, and currently the baseline ion-exchanger for removal of cesium ion at Hanford, is compared with the R-F resin. The primary structural unit of the R-F resin was determined to consist of a 1,2,3,4-tetrasubstituted resorcinol ring unit while CS-100, was composed mainly of a 1,2,4-trisubstituted ring. CS-100 shows the presence of phenoxy-ether groups, and this may account for the much lower decontamination factor of CS-100 for cesium ion. Curing temperatures for the R-F resin were found to be optimal at 105--130C. At lower temperatures, insufficient curing, hence crosslinking, of the polymer resin occurs and selectivity for cesium drops. Curing at elevated temperatures leads to chemical degradation. Optimal particle size for R-F resin is in the range of 20--50 mesh-sized particles. R-F resin undergoes chemical degradation or oxidation which destroys ion-exchange sites. The ion-exchange sites (hydroxyl groups) are converted to quinones and ketones. CS-100, though it has much lower performance for cesium ion-exchange, is significantly more chemically stable than R-F resin. To gamma radiation, CS-100 is more radiolytically stable than R-F resin.

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

    NASA Technical Reports Server (NTRS)

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

    1978-01-01

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

  16. Implications of using approximate Bloch-McConnell equations in NMR analyses of chemically exchanging systems: application to the electron self-exchange of plastocyanin

    NASA Astrophysics Data System (ADS)

    Flemming Hansen, D.; Led, Jens J.

    2003-08-01

    enhancement of the nuclear relaxation rates, the paramagnetic chemical shift, the electron relaxation rate, the electron self-exchange rate, and the distances between the nuclei and the paramagnetic metal ion, viz. the Cu 2+ ion.

  17. Reverse electrodialysis using bipolar ion-exchange membranes as a source of electric energy

    SciTech Connect

    Pivovarov, N.Ya.; Greben`, V.P.; Kovarskii, N.Ya.

    1994-06-01

    It is established that, in the regime of the H{sup +} and OH{sup {minus}} ions recombination, voltage on the bipolar membranes and the efficiency of the latter, as a transformer of chemical energy into electric, increases in the series of ionogen groups contained in the bipolar region. This is due to an increase in the recombination rate constants in the bipolar contact for the H{sup +} and OH{sup {minus}} ions. As the sodium and chlorine ions penetrate the bipolar transition region, they sharply decrease the membrane potential and the voltage drop on the bipolar membranes, because the ionogen groups turn into salt form, which is catalytically inactive in the H{sup +} and OH{sup {minus}} ions recombination reaction. It is shown that the source of current, containing the MB-24 (bipolar), MF-4sk (cation-exchange), and AMV (anion-exchange) ion-exchange membranes, has a specific power of 0.11 W/dm{sup 2} (calculated in terms of one bipolar membrane) and efficiency of 29% for 0.5 M solution of hydrochloric acid and sodium hydroxide, and 0.5 A/dm{sup 2} current density.

  18. Ion exchange at the critical point of solution.

    PubMed

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

    2016-03-11

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

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

    PubMed

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

    2015-05-01

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

  20. Detoxification of lignocellulose hydrolysates with ion-exchange resins.

    PubMed

    Nilvebrant, N O; Reimann, A; Larsson, S; Jönsson, L J

    2001-01-01

    Lignocellulose hydrolysates contain fermentation inhibitors causing decreased ethanol production. The inhibitors include phenolic compounds, furan aldehydes, and aliphatic acids. One of the most efficient methods for removing inhibiting compounds prior to fermentation is treatment of the hydrolysate with ion-exchange resins. The performance and detoxification mechanism of three different resins were examined: an anion exchanger, a cation exchanger, and a resin without charged groups (XAD-8). A dilute acid hydrolysate of spruce was treated with the resins at pH 5.5 and 10.0 prior to ethanolic fermentation with Saccharomyces cerevisiae. In addition to the experiments with hydrolysate, the effect of the resins on selected model compounds, three phenolics (vanillin, guaiacol, and coniferyl aldehyde) and two furan aldehydes (furfural and hydroxymethyl furfural), was determined. The cation exchanger increased ethanol production, but to a lesser extent than XAD-8, which in turn was less effective than the anion exchanger. Treatment at pH 10.0 was more effective than at pH 5.5. At pH 10.0, the anion exchanger efficiently removed both anionic and uncharged inhibitors, the latter by hydrophobic interactions. The importance of hydrophobic interactions was further indicated by a substantial decrease in the concentration of model compounds, such as guaiacol and furfural, after treatment with XAD-8. PMID:11963864

  1. Nanostructured Ion-Exchange Membranes for Fuel Cells: Recent Advances and Perspectives.

    PubMed

    He, Guangwei; Li, Zhen; Zhao, Jing; Wang, Shaofei; Wu, Hong; Guiver, Michael D; Jiang, Zhongyi

    2015-09-23

    Polymer-based materials with tunable nanoscale structures and associated microenvironments hold great promise as next-generation ion-exchange membranes (IEMs) for acid or alkaline fuel cells. Understanding the relationships between nanostructure, physical and chemical microenvironment, and ion-transport properties are critical to the rational design and development of IEMs. These matters are addressed here by discussing representative and important advances since 2011, with particular emphasis on aromatic-polymer-based nanostructured IEMs, which are broadly divided into nanostructured polymer membranes and nanostructured polymer-filler composite membranes. For each category of membrane, the core factors that influence the physical and chemical microenvironments of the ion nanochannels are summarized. In addition, a brief perspective on the possible future directions of nanostructured IEMs is presented. PMID:26270555

  2. Solidification of ion exchange resin wastes in hydraulic cement

    SciTech Connect

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

    1982-01-01

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

  3. Design software for ion-exchanged glass waveguide devices

    NASA Astrophysics Data System (ADS)

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

    1993-04-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-06-01

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

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

    DOEpatents

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

    1958-04-15

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

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

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

    EPA Science Inventory

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

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

  9. A Cu(II)2 Paramagnetic Chemical Exchange Saturation Transfer Contrast Agent Enabled by Magnetic Exchange Coupling.

    PubMed

    Du, Kang; Harris, T David

    2016-06-29

    The ability of magnetic exchange coupling to enable observation of paramagnetic chemical exchange saturation transfer (PARACEST) in transition metal ions with long electronic relaxation times (τs) is demonstrated. Metalation of the dinucleating, tetra(carboxamide) ligand HL with Cu(2+) in the presence of pyrophosphate (P2O7)(4-) affords the complex [LCu(II)2(P2O7)](-). Solution-phase variable-temperature magnetic susceptibility data reveal weak ferromagnetic superexchange coupling between the two S = 1/2 Cu(II) centers, with a coupling constant of J = +2.69(5) cm(-1), to give an S = 1 ground state. This coupling results in a sharpened NMR line width relative to a GaCu analogue, indicative of a shortening of τs. Presaturation of the amide protons in the Cu2 complex at 37 °C leads to a 14% intensity decrease in the bulk water (1)H NMR signal through the CEST effect. Conversely, no CEST effect is observed in the GaCu complex. These results provide the first example of a Cu-based PARACEST magnetic resonance contrast agent and demonstrate the potential to expand the metal ion toolbox for PARACEST agents through introduction of magnetic exchange coupling. PMID:27276533

  10. Momentum transfer in relativistic heavy ion charge-exchange reactions

    NASA Technical Reports Server (NTRS)

    Townsend, L. W.; Wilson, J. W.; Khan, F.; Khandelwal, G. S.

    1991-01-01

    Relativistic heavy ion charge-exchange reactions yield fragments (Delta-Z = + 1) whose longitudinal momentum distributions are downshifted by larger values than those associated with the remaining fragments (Delta-Z = 1, -2,...). Kinematics alone cannot account for the observed downshifts; therefore, an additional contribution from collision dynamics must be included. In this work, an optical model description of collision momentum transfer is used to estimate the additional dynamical momentum downshift. Good agreement between theoretical estimates and experimental data is obtained.