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Sample records for acid exchange resins

  1. Phosphonic acid based exchange resins

    DOEpatents

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

    1995-01-01

    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.

  2. Phosphonic acid based exchange resins

    DOEpatents

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

    1995-09-12

    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.

  3. 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.

  4. 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.

  5. Phosphonic acid based ion exchange resins

    DOEpatents

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

    1994-01-25

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

  6. Phosphonic acid based ion exchange resins

    DOEpatents

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

    1996-07-23

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

  7. Bifunctional phenyl monophosphonic/sulfonic acid ion exchange resin and process for using the same

    DOEpatents

    Alexandratos, Spiro; Shelley, Christopher A.; Horwitz, E. Philip; Chiarizia, Renato; Gula, Michael J.; Xue, Sui; Harvey, James T.

    2002-01-01

    A cross-linked water-insoluble ion exchange resin comprised of polymerized monomers having a phenyl ring is disclosed. A contemplated resin contains (i) polymerized phenyl ring-containing monomers having a phosphonic acid ligand linked to the phenyl ring, (ii) about 2 to about 5 millimoles per gram (mmol/g) of phosphorus as phosphonic acid ligands, and (iii) a sufficient amount of a sulfonic acid ligand such that the ratio of mmol/g of phosphonic acid to mmol/g sulfonic acid is up to 3:1. A process for removing polyvalent metal cations from aqueous solution, and a process for removing iron(III) cations from acidic copper(II) cation-containing solutions that utilize the contemplated resin or other resins are disclosed.

  8. Bifunctional phenyl monophosphonic/sulfonic acid ion exchange resin and process for using the same

    DOEpatents

    Alexandratos, Spiro; Shelley, Christopher A.; Horwitz, E. Philip; Chiarizia, Renato

    2001-01-01

    A cross-linked water-insoluble ion exchange resin comprised of polymerized monomers having a phenyl ring is disclosed. A contemplated resin contains (i) polymerized phenyl ring-containing monomers having a phosphonic acid ligand linked to the phenyl ring, (ii) about 2 to about 5 millimoles per gram (mmol/g) of phosphorus as phosphonic acid ligands, and (iii) a sufficient amount of a sulfonic acid ligand such that the ratio of mmol/g of phosphonic acid to mmol/g sulfonic acid is up to 3:1. A process for removing polyvalent metal cations from aqueous solution, and a process for removing iron(III) cations from acidic copper(II) cation-containing solutions that utilize the contemplated resin or other resins are disclosed.

  9. Some investigations on the radiation stability of a strongly acidic cation exchange resin

    NASA Astrophysics Data System (ADS)

    Dessouki, A. M.; Zahran, A. H.; Rabie, A. M.; Amer, S. I.

    The radiation-chemical stability of Merck Cation Exchanger I, a strongly acidic sulphonated cation exchanger of the polymerization type based on styrene-divinylbenze (DVB) copolymers was investigated. The radiation stability of the resin was assessed from the change in exchange capacity, loss in weight, change in swelling behaviour and formation of new exchange groups. The loss in capacity was 44 and 32% for resin specimens in the H +-form irradiated to 1000 Mrad in air and in vacuum, respectively. The Na +-form of the exchanger showed high resistance to radiation and the loss in capacity did not exceed 7% at a dose of 1000 Mrad. The loss in capacity was accompanied by a loss in weight and a decrease in the degree of swelling of the irradiated resin. The formation of new functional groups of the carboxylic and phenolic types was confirmed. The amount of these group increases with the increase in the integral dose. The amount of sulphuric acid formed as a result of irradiating the resin in the dry and moist states was determined. An increase in the moisture content of the resin resulted in a marked decrease in its radiation stability.

  10. Elution profiles of lanthanides with α-hydroxyisobutyric acid by ion exchange chromatography using fine resin.

    PubMed

    Trikha, Rahul; Sharma, Bal Krishan; Sabharwal, Kanwal Nain; Prabhu, Krishan

    2015-11-01

    Experiments were carried out using a strong acid cation exchange resin with a particle size of 75-150 μm, termed as "fine resin" in hydrogen ion form for the elution of individual lanthanides Sm, Eu, Gd, Tb, and Dy that are produced as fission products in the spent nuclear fuel and generated in the effluent during reprocessing of spent nuclear fuel. Batch experiments were carried out to study the effect of concentration of nitric acid on distribution coefficient. The distribution coefficient values for these individual lanthanides were determined in nitric acid medium in the concentration range of 0.01-4.0 N. Uptake of each individual lanthanide by resin was increased with increased nitric acid concentration from 0.01 to 0.5 N and remained similar from 0.5 to 1.0 N and decreased thereafter up to 4.0 N. Column experiments were also carried out using the same resin to study the parameters like pH of the eluent, flow rate, and resin bed height under isocratic elution conditions for eluting lanthanide elements using α-hydroxyisobutyric acid as eluent. The results of this study have indicated the possibility for the elution of individual lanthanides. PMID:26333182

  11. Synthesis and properties of a cation exchange resin prepared by the pyrolysis of starch in the presence of phytic acid

    SciTech Connect

    Lehrfeld, J.

    1995-12-01

    A material having cation exchange and adsorption properties was prepared by the controlled pyrolysis of starch in the presence of a commercial phytic acid solution. Resins can be prepared with binding capacities of 0.7-5.7 meq/g. These resins also have the ability to remove atrazine from aqueous solutions.

  12. Isolation and separation of transplutonium elements from other actinides on ion exchange resins from aqueous and aqueous ethanol solutions of sulfuric acid

    SciTech Connect

    Guseva, L.I.; Tikhomirova, G.S.; Stepushkina, V.V.

    1987-11-01

    The behavior of Am, Cm, Bk, Cf, Es, and other actinides, as well as Zr, on an anion exchange resin and a cation exchange resin in aqueous and aqueous alcohol solutions of sulfuric acid was investigated as a function of the concentration of various components of the solution. It was found that the presence of alcohol in sulfuric acid solutions leads to an increase in the distribution coefficients both on cation exchange resins and on anion exchange resins. The possibility of using ion exchange resins for the concentration and separation of transplutonium elements from U, Np, Pu, Zr, and other elements that form strong complexes with sulfate ions in a wide range of sulfuric acid concentrations was demonstrated.

  13. 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.

  14. 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.

  15. Ion-exclusion chromatography with conductimetric detection of aliphatic carboxylic acids on a weakly acidic cation-exchange resin by elution with benzoic acid-beta-cyclodextrin.

    PubMed

    Tanaka, Kazuhiko; Mori, Masanobu; Xu, Qun; Helaleh, Murad I H; Ikedo, Mikaru; Taoda, Hiroshi; Hu, Wenzhi; Hasebe, Kiyoshi; Fritz, James S; Haddad, Paul R

    2003-05-16

    In this study, an aqueous solution consisting of benzoic acid with low background conductivity and beta-cyclodextrin (beta-CD) of hydrophilic nature and the inclusion effect to benzoic acid were used as eluent for the ion-exclusion chromatographic separation of aliphatic carboxylic acids with different pKa values and hydrophobicity on a polymethacrylate-based weakly acidic cation-exchange resin in the H+ form. With increasing concentration of beta-cyclodextrin in the eluent, the retention times of the carboxylic acids decreased due to the increased hydrophilicity of the polymethacrylate-based cation-exchange resin surface from the adsorption of OH groups of beta-cyclodextrin. Moreover, the eluent background conductivity decreased with increasing concentration of beta-cyclodextrin in 1 mM benzoic acid, which could result in higher sensitivity for conductimetric detection. The ion-exclusion chromatographic separation of carboxylic acids with high resolution and sensitivity was accomplished successfully by elution with a 1 mM benzoic acid-10 mM cyclodextrin solution without chemical suppression. PMID:12830884

  16. 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.

  17. 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.

  18. 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.

  19. Separation of Bk(IV) and Ce(IV) from trivalent transplutonium and rare earth elements on ion exchange resins in solutions of sulfuric acid

    SciTech Connect

    Guseva, L.I.; Stepushkina, V.V.

    1987-11-01

    Th behavior of Am, Cm, Bk, Cf, Es, Ce, Eu, and Pr on an anion exchange resin and a cation exchange resin in a mixture with PbO/sub 2/ was investigated in sulfuric acid solutions. A substantial difference was detected in the distribution coefficients of Bk and Ce, on the one hand, and the remaining transplutonium and rare earth elements, on the other, associated with oxidation of the first two elements to the tetravalent state. Methods are proposed for the concentration and separation of Bk(IV) and Ce(IV) from the other transplutonium and rare earth elements on an anion exchange resin in solution of 0.01-0.25 M H/sub 2/SO/sub 4/ and a cation exchange resin in 0.75-1.0 M H/sub 2/SO/sub 4/.

  20. Use of potassium-form cation-exchange resin as a conductimetric enhancer in ion-exclusion chromatography of aliphatic carboxylic acids.

    PubMed

    Iwata, Tomotaka; Mori, Masanobu; Itabashi, Hideyuki; Tanaka, Kazuhiko

    2009-09-15

    In this study, a cation-exchange resin (CEX) of the K(+)-form, i.e., an enhancer resin, is used as a postcolumn conductimetric enhancer in the ion-exclusion chromatography of aliphatic carboxylic acids. The enhancer resin is filled in the switching valve of an ion chromatograph; this valve is usually used as a suppressor valve in ion-exchange chromatography. An aliphatic carboxylic acid (e.g., CH(3)COOH) separated by a weakly acidic CEX column of the H(+)-form converts into that of the K(+)-form (e.g., CH(3)COOK) by passing through the enhancer resin. In contrast, the background conductivity decreases because a strong acid (e.g., HNO(3)) with a higher conductimetric response in an eluent converts into a salt (e.g., KNO(3)) with a lower conductimetric response. Since the pH of the eluent containing the resin enhancer increases from 3.27 to 5.85, the enhancer accelerates the dissociations of analyte acids. Consequently, peak heights and peak areas of aliphatic carboxylic acids (e.g., acetic acid, propionic acid, butyric acid, and valeric acid) with the enhancer resin are 6.3-8.0 times higher and 7.2-9.2 times larger, respectively, than those without the enhancer resin. Calibrations of peak areas for injected analytes are linear in the concentration range of 0.01-1.0mM. The detection limits (signal-to-noise ratio=3) range from 0.10 microM to 0.39 microM in this system, as opposed to those in the range of 0.24-7.1 microM in the separation column alone. The developed system is successfully applied to the determination of aliphatic carboxylic acids in a chicken droppings sample. PMID:19615503

  1. 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.

  2. Utilization of cation exchange resins for the isolation and separation of transplutonium elements from others in aqueous and non aqueous-alcohol solutions of hydrochloric and nitric acids

    SciTech Connect

    Guseva, L.I.; Tikhomirova, G.S.

    1985-07-01

    The authors study the sorption of several transplutonium and fission elements on cation exchange resins in relation to the acid concentration and content of alcohol in solution. They observe a significant increase in sorption of the TPE on the cation exchanges from nitric acid solutions containing more than 50% of alcohol. On the basis of the experimental results they determine the optimum conditions for the concentration of TPE on cation exchangers with their subsequent separation from certain fission and other elements by means of hydrochloric acid and nitric acid solutions.

  3. 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}.

  4. Determination of some aliphatic carboxylic acids in anaerobic digestion process waters by ion-exclusion chromatography with conductimetric detection on a weakly acidic cation-exchange resin column.

    PubMed

    Ito, Kazuaki; Takayama, Yohichi; Ikedo, Mikaru; Mori, Masanobu; Taoda, Hiroshi; Xu, Qun; Hu, Wenzhi; Sunahara, Hiroshi; Hayashi, Tsuneo; Sato, Shinji; Hirokawa, Takeshi; Tanaka, Kazuhiko

    2004-06-11

    The determination of seven aliphatic carboxylic acids, formic, acetic, propionic, isobutyric, n-butyric, isovaleric and n-valeric acids in anaerobic digestion process waters was examined using ion-exclusion chromatography with conductimetric detection. The analysis of these biologically important carboxylic acids is necessary as a measure for evaluating and controlling the process. The ion-exclusion chromatography system employed consisted of polymethacrylate-based weakly acidic cation-exchange resin columns (TSKgel OApak-A or TSKgel Super IC-A/C). weakly acidic eluent (benzoic acid), and conductimetric detection. Particle size and cation-exchange capacity were 5 microm and 0.1 meq./ml for TSKgel OApak-A and 3 microm and 0.2 meq./ml for TSKgel Super IC-A/C, respectively. A dilute eluent (1.0-2.0 mM) of benzoic acid was effective for the high resolution and highly conductimetric detection of the carboxylic acids. The good separation of isobutyric and n-butyric acids was performed using the TSKgel Super IC-A/C column (150 mm x 6.0 mm i.d. x 2). The simple and good chromatograms were obtained by the optimized ion-exclusion chromatography conditions for real samples from mesophilic anaerobic digestors, thus the aliphatic carboxylic acids were successfully determined without any interferences. PMID:15250416

  5. 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

  6. 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.

  7. 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.

  8. Preparation and characterization of anion exchange resin decorated with magnetite nanoparticles for removal of p-toluic acid from aqueous solution

    NASA Astrophysics Data System (ADS)

    Davarpanah, Morteza; Ahmadpour, Ali; Rohani Bastami, Tahereh

    2015-02-01

    Polystyrene resin was covalently functionalized with diethanolamine and then decorated with magnetite nanoparticles by a novel and simple co-precipitation method using iron(II) sulfate as precursor. The products were characterized by Fourier transform infrared spectroscopy, elemental analysis, X-ray diffraction, Mössbauer spectroscopy, field-emission scanning electron microscopy and vibrating sample magnetometer. Adsorption of p-toluic acid (p-TA) onto magnetite-decorated polystyrene (MAG-PS) was studied and compared with that of diethanolamine-functionalized polystyrene and a commercial anion exchange resin. Results showed that the magnetite nanoparticles with an average size of 20.4 nm were successfully formed on the surface of polystyrene resin, and MAG-PS was exhibited high affinity for the removal of p-TA.

  9. Evaluation of Elution Parameters for Cesium Ion Exchange Resins

    SciTech Connect

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

    2006-08-28

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

  10. 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.

  11. Rapid removal of copper with magnetic poly-acrylic weak acid resin: quantitative role of bead radius on ion exchange.

    PubMed

    Fu, Lichun; Shuang, Chendong; Liu, Fuqiang; Li, Aimin; Li, Yan; Zhou, Yang; Song, Haiou

    2014-05-15

    A novel magnetic weak acid resin NDMC was self-synthesized for the removal of Cu(2+) from aqueous solutions. NDMC showed superior properties on the removal of Cu(2+) compared to commercial resins C106 and IRC-748, which was deeply investigated by adsorption isotherms and kinetic tests. The equilibrium adsorption amount of Cu(2+) onto NDMC (267.2mg/g) was almost twice as large as that onto IRC-748 (120.0mg/g). The adsorption kinetics of Cu(2+) onto the three resins fitted well with the pseudo-second-order equation. The initial adsorption rate h of NDMC was about 4 times that of C106 and nearly 8 times that of IRC-748 at the initial concentration of 500mg/L. External surface area was determined to be the key factor in rate-controlling by further analyzing the adsorption thermodynamics, kinetics parameters and physicochemical properties of the resins. NDMC resin with the smallest bead radius possessed the largest external surface and therefore exhibited the fastest kinetics. The adsorption amount of Cu(2+) onto NDMC was not influenced as the concentration of Na(+) increased from 1.0 to 10.0mM/L. Dilute HCl solution could effectively desorb Cu(2+). NDMC demonstrated high stability during 10 adsorption/desorption cycles, showing great potential in the rapid removal of Cu(2+) from wastewater. PMID:24681592

  12. Commercial Ion Exchange Resin Vitrification in Borosilicate Glass

    SciTech Connect

    Cicero-Herman, C.A.; Workman, P.; Poole, K.; Erich, D.; Harden, J.

    1998-05-01

    Bench-scale studies were performed to determine the feasibility of vitrification treatment of six resins representative of those used in the commercial nuclear industry. Each resin was successfully immobilized using the same proprietary borosilicate glass formulation. Waste loadings varied from 38 to 70 g of resin/100 g of glass produced depending on the particular resin, with volume reductions of 28 percent to 68 percent. The bench-scale results were used to perform a melter demonstration with one of the resins at the Clemson Environmental Technologies Laboratory (CETL). The resin used was a weakly acidic meth acrylic cation exchange resin. The vitrification process utilized represented a approximately 64 percent volume reduction. Glass characterization, radionuclide retention, offgas analyses, and system compatibility results will be discussed in this paper.

  13. 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.

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

    SciTech Connect

    Duncan, J.B.

    1998-08-25

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

  15. Enrichment and low-level determination of glyphosate, aminomethylphosphonic acid and glufosinate in drinking water after cleanup by cation exchange resin.

    PubMed

    Küsters, Markus; Gerhartz, Michael

    2010-04-01

    For the determination of glyphosate, aminomethylphosphonic acid and glufosinate in drinking water, different procedures of enrichment and cleanup were examined using anion exchange or SPE. In many cases interactions of, e.g. alkaline earth metal ions especially calcium could be observed during enrichment and cleanup resulting in loss of analytes. For that reason, a novel cleanup and enrichment procedure for the determination of these phosphonic acid herbicides has been developed in drinking water using cation-exchange resin. In summary, the cleanup procedure with cation-exchange resin developed in this study avoids interactions as described above and is applicable to calcium-rich drinking water samples. After derivatization with 9-fluorenylmethylchloroformate followed by LC with fluorescence detection, LOD of 12, 14 and 12 ng/L and mean recoveries from real-world drinking water samples of 98+/-9, 100+/-16 and 101+/-11% were obtained for glyphosate, aminomethylphosphonic acid and glufosinate, respectively. The low LODs and the high precision permit the analysis of these phosphonic acid herbicides according to the guidelines of the European Commission. PMID:20183819

  16. Use of a polystyrene-divinylbenzene-based weakly acidic cation-exchange resin column and propionic acid as an eluent in ion-exclusion/adsorption chromatography of aliphatic carboxylic acids and ethanol in food samples.

    PubMed

    Mori, Masanobu; Hironaga, Takahiro; Kajiwara, Hiroe; Nakatani, Nobutake; Kozaki, Daisuke; Itabashi, Hideyuki; Tanaka, Kazuhiko

    2011-01-01

    We developed an ion-exclusion/adsorption chromatography (IEAC) method employing a polystyrene-divinylbenzene-based weakly acidic cation-exchange resin (PS-WCX) column with propionic acid as the eluent for the simultaneous determination of multivalent aliphatic carboxylic acids and ethanol in food samples. The PS-WCX column well resolved mono-, di-, and trivalent carboxylic acids in the acidic eluent. Propionic acid as the eluent gave a higher signal-to-noise ratio, and enabled sensitive conductimetric detection of analyte acids. We found the optimal separation condition to be the combination of a PS-WCX column and 20-mM propionic acid. Practical applicability of the developed method was confirmed by using a short precolumn with a strongly acidic cation-exchange resin in the H(+)-form connected before the separation column; this was to remove cations from food samples by converting them to hydrogen ions. Consequently, common carboxylic acids and ethanol in beer, wine, and soy sauce were successfully separated by the developed method. PMID:21558657

  17. Evaluation of a new, macroporous polyvinylpyridine resin for processing plutonium using nitrate anion exchange

    SciTech Connect

    Marsh, S.F.

    1989-04-01

    Anion exchange in nitric acid is the major aqueous process used to recover and purify plutonium from impure scrap materials. Most strong-base anion exchange resins incorporate a styrene-divinylbenzene copolymer. A newly available, macroporous anion exchange resin based on a copolymer of 1-methyl-4-vinylpyridine and divinylbenzene has been evaluated. Comparative data for Pu(IV) sorption kinetics and capacity are presented for this new resin and two other commonly used anion exchange resins. The new resin offers high capacity and rapid sorption kinetics for Pu(IV) from nitric acid, as well as greatly stability to chemical and radiolytic degradation. 8 refs., 14 figs.

  18. 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…

  19. 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.

  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. Ion Exchange Temperature Testing with SRF Resin - 12088

    SciTech Connect

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

    2012-07-01

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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Adsorption of o-cresol and benzoic acid in an adsorber packed with an ion-exchange resin: A comparative study of diffusional models

    SciTech Connect

    Run-Tun Huang; Teh-Liang Chen; Hung-Shan Weng

    1994-10-01

    Both solid- and pore-diffusion models were employed to simulate the adsorption of o-cresol and benzoic acid in a fixed-bed adsorber packed with an anion-exchange resin. The equilibrium adsorption data were modeled by a Langmuir isotherm. When the shape of the adsorption isotherm was approximately linear (as in the case of o-cresol), both models agreed well with the experimental break-through data, and they could be effectively applied to predict the breakthrough curve of longer columns. For a favorable adsorption isotherm (say, benzoic acid), however, better results were obtained by using the solid-diffusion model. In addition to the shape of the adsorption isotherm, several factors, such as the type of adsorbent, modeling of equilibrium data, computation efficiency, and concentration dependence of the intraparticle diffusivity, should also be taken into account for selecting a suitable diffusion model.

  7. 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.

  8. CHARACTERIZATION OF CYCLED SPHERICAL RESORCINOL-FORMALDEHYDE ION EXCHANGE RESIN

    SciTech Connect

    Nash, C.; Duignan, M.

    2010-02-23

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

  9. 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

  10. 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.

  11. A mechanism for enhancing ionic accessibility into selective ion exchange resins

    SciTech Connect

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

    1998-07-01

    A bifunctional monophosphonic/sulfonic acid ion exchange resin with high capacity has been synthesized. Metal ion studies have been carried out with europium, americium, and ferric nitrate in solutions of varying acidity, with and without sodium nitrate added. The bifunctional resin complexes far higher levels of Eu(III) from 0.5 and 1 N nitric acid than the monofunctional phosphonic acid resin. It is postulated that the sulfonic acid ligand provides an access mechanism for the metal ions into the polymer matrix by hydrating the matrix and preventing its collapse in high ionic strength solutions thus allowing for rapid ionic complexation by the selective phosphonic acid ligands. The bifunctional monophosphonic/sulfonic acid resin has both ligands bound to a polystyrene support. It complexes higher levels of metal ions than a comparable resin differing only by having the monophosphonic acid ligand directly bound to the C-C backbone. Results are compared to a diphosphonic/sulfonic acid resin.

  12. K Basin Sludge Conditioning Process Testing Project Results from Test 4, ''Acid Digestion of Mixed-Bed Ion Exchange Resin''

    SciTech Connect

    Pool, K.H.; Delegard, C.H.; Schmidt, A.J.; Thornton, B.M.; Silvers, K.L.

    1999-04-02

    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. Ultimately, it is planned to transfer the K Basins sludge to the Hanford double shell tanks (DSTs). The Hanford Spent Nuclear Fuel (HSNF) project has conducted a number of evaluations to examine technology and processing alternatives to pretreat K Basin sludge to meet storage and disposal requirements. From these evaluations, chemical pretreatment has been selected to address criticality issues, reactivity, and the destruction or removal of PCBs before the K Basin sludge can be transferred to the DSTs. Chemical pretreatment, referred to as the K Basin sludge conditioning process, includes nitric acid dissolution of the sludge (with removal of acid insoluble solids), neutrons absorber addition, neutralization, and reprecipitation. Laboratory testing is being conducted by the Pacific Northwest National Laboratory (PNNL) to provide data necessary to develop the sludge conditioning process.

  13. 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.

  14. Organic ion exchange resin separation methods evaluation

    SciTech Connect

    Witwer, K.S.

    1998-05-27

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

  15. Carboxymethylated polyethylenimine-polymethylenepolyphenylene isocyanate chelating ion exchange resin preconcentration for inductively coupled plasma spectrometry

    SciTech Connect

    Horvath, A.; Barnes, R.M.

    1986-06-01

    A carboxymethylated polyethylenimine-polylmethylenepolyphenylene isocyanate chelating ion exchange resin was prepared, characterized, and used for metals preconcentration for inductively coupled plasma spectrometry. The uptake of copper, cadmium, lead, and zinc by the resin was quantitative in the presence of high concentrations of ammonium, calcium, magnesium, potassium, sodium, and acetate and citrate salts. These metals could be collected from artificial seawater, Dead Sea water, and dissolved bone with a recovery of nearly 100%. The resin also chelates heavy metals and rare earths. Complexed metals can be eluted from the resin column with strong acids. The resin does not change volume with ionic form changes and can be regenerated for repeated use.

  16. 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...

  17. 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...

  18. CATALYTIC PROMOTION OF THE ADSORPTION OF VANADIUM ON AN ANIONIC EXCHANGE RESIN

    DOEpatents

    Bailes, R.H.; Ellis, D.A.

    1958-08-26

    An improvement in the process for the recovery of vanadium from acidic phosphatic solutions is presented. In this process the vanadium is first oxidized to the pentavaleat state, and is then separated by contacting such solutions with an anion exchange resin whereby adsorption of the complexed pentavalent vanadium is effected. The improvement lies in the fact that adsorp tion of the vanadium complex by the anion exchange resin is promoted and improved by providing fiuoride ions in solution to be contacted.

  19. Anion-exchange resin-based desulfurization process

    SciTech Connect

    Sheth, A.C.; Dharmapurikar, R.

    1992-01-01

    Under DOE Grant No. DE-FG22-90PC90309, the University of Tennessee Space Institute (UTSI) is contracted to further develop its anion-exchange, resin-based desulfurization concept to desulfurize alkali metal sulfates. From environmental as well as economic viewpoints, it is necessary to remove soluble sulfates from the wastes created by flue gas desulfurization systems. In order to do this economically, a low-cost desulfurization process for spent sorbents is necessary. UTSI's anion-exchange resin-based desulfurization concept is believed to satisfy these requirements. During the reporting period, October 1, 1992--December 31, 1992, UTSI has completed the batch mode experiments to evaluate the performance enhancement effect caused by organic acids on the resin's exhaustion efficiency. At present, batch mode experiments are being conducted to locate the position of the CO[sub 3]= and SO[sub 4]= ions in the affinity chart, and also reviewing/assessing the ASPEN Code's capabilities for use in the development of the Best Process Schematic and related economics.

  20. Method for digesting spent ion exchange resins and recovering actinides therefrom using microwave radiation

    DOEpatents

    Maxwell, III, Sherrod L.; Nichols, Sheldon T.

    1999-01-01

    The present invention relates to methods for digesting diphosphonic acid substituted cation exchange resins that have become loaded with actinides, rare earth metals, or heavy metals, in a way that allows for downstream chromatographic analysis of the adsorbed species without damage to or inadequate elution from the downstream chromatographic resins. The methods of the present invention involve contacting the loaded diphosphonic acid resin with concentrated oxidizing acid in a closed vessel, and irradiating this mixture with microwave radiation. This efficiently increases the temperature of the mixture to a level suitable for digestion of the resin without the use of dehydrating acids that can damage downstream analytical resins. In order to ensure more complete digestion, the irradiated mixture can be mixed with hydrogen peroxide or other oxidant, and reirradiated with microwave radiation.

  1. Management of Spent Organic Ion-Exchange Resins by Photochemical Oxidation

    SciTech Connect

    Srinivas, C.; Sugilal, S.; Wattal, P. K.

    2003-02-26

    Management of spent ion-exchange resin waste arising from nuclear reactor operations by traditional practice of encapsulation in cement is associated with problems such as swelling and disintegration. Complete oxidation (mineralization) is an attractive alternative option. This paper reports the development of photochemical mineralization process for organic ion-exchange resins of poly (styrene-divinyl benzene) type with sulfonic acid and quaternary ammonium functional groups. It is a two-step process consisting of dissolution (conversion of solid resin into water-soluble reaction products) and photo-Fenton mineralization of the dissolved resin. Cation and anion resin dissolution was effected by reaction of the resin with H2O2 at 50-60 C in the presence of ferrous/copper sulphate catalyst. Direct dissolution of mixed resin was not efficient. However, the cation resin portion in the mixed resin could be selectively dissolved without affecting the anion portion. The solid anion resin after separation from the cation resin solution could be dissolved. About 0.5 liters of 50% H2O2 was required for dissolution of one kg of wet resin. The reaction time was 4-5 hours. Dissolution experiments were conducted on up to 8 liters of wet resin. The second step, viz., photo-Fenton mineralization of the dissolved resin was effected at ambient temperature(25-35 C). Kinetic results of laboratory scale experiments in immersion type photo-reactor and pilot scale experiments in tubular flow photo-reactor were presented. These results clearly demonstrated the photo-Fenton mineralization of dissolved resin at ambient temperature with stoichiometric quantity of H2O2 as against 70-200% excess H2O2 requirement in chemical mineralization experiments under Fenton oxidation conditions at 90-95 C. Based on these studies, a treatment scheme was developed and presented in this paper.

  2. 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.

  3. 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.

  4. Bifunctional anion-exchange resins with improved selectivity and exchange kinetics

    DOEpatents

    Alexandratos, Spiro D.; Brown, Gilbert M.; Bonnesen, Peter V.; Moyer, Bruce A.

    2000-01-01

    Disclosed herein are a class of anion exchange resins containing two different exchange sites with improved selectivity and sorptive capability for chemical species in solution, such as heptavalent technetium (as pertechnetate anion, TcO.sub.4.sup.-). The resins are prepared by first reacting haloalkylated crosslinked copolymer beads with a large tertiary amine in a solvent in which the resin beads can swell, followed by reaction with a second, smaller, tertiary amine to more fully complete the functionalization of the resin. The resins have enhanced selectivity, capacity, and exchange kinetics.

  5. 21 CFR 176.110 - Acrylamide-acrylic acid resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Acrylamide-acrylic acid resins. 176.110 Section... Paper and Paperboard § 176.110 Acrylamide-acrylic acid resins. Acrylamide-acrylic acid resins may be...) Acrylamide-acrylic acid resins are produced by the polymerization of acrylamide with partial hydrolysis or...

  6. Anion-exchange resin-based desulfurization process. Final report

    SciTech Connect

    Sheth, A C; Dharmapurikar, R; Strevel, S D

    1994-01-01

    The following investigations were performed: (1) batch mode screening of eleven(11) commercially available resins and selection of three candidate resins for further evaluation in a fixed-bed setup. (2) Process variables study using three candidate resins in the fixed-bed setup and selection of the ``best`` resin for process economics development. (3) Exhaustion efficiency and solution concentration were found to be inversely related necessitating a trade-off between the resin cost versus the cost of evaporation/concentration of ensuing effluents. (4) Higher concentration of the HCO{sub 3}{sup {minus}} form of active sites over less active CO{sub 3}{sup 2{minus}} form of sites in the resin was believed to be the main reason for the observed increase in the equilibrium capacity of the resin at an elevated static CO{sub 2}-pressure. This Increase in capacity was found to level off around 80--120 psig range. The increase in CO{sub 2}-pressure, however, did not appear to affect the overall ion-exchange kinetics. (5) In the fixed-bed mode, the solution concentration was found to affect the equilibrium capacity of candidate resins. Their relationship was well satisfied by the Langmuir type non-linear equilibrium isotherm. Alternatively, the effect of solution concentration on overall ion-exchange kinetics varied from resin to resin. (6) Product inhibition effect on the resin was observed as an initial increase followed by a significant decrease in the resin`s equilibrium capacity for SO{sub 4}{sup 2{minus}} as the HCO{sub 3}{sup {minus}}/SO{sub 4}{sup 2{minus}} molar ratio in the solution was increased from 0 to 1.0. This ratio, however, did not affect the overall ion-exchange kinetics.

  7. 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.

  8. 21 CFR 173.25 - Ion-exchange resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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

  9. 21 CFR 173.25 - Ion-exchange resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

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

  10. 21 CFR 173.25 - Ion-exchange resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

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

  11. The sorption capacity of boron on anionic-exchange resin

    SciTech Connect

    Lou, J.; Foutch, G.L.; Na, J.W.

    1999-11-01

    Boron sorption capacities on anionic-exchange resins vary with temperature, concentration, and resin crosslinkage. A semiempirical correlation, developed from boron solution chemistry, is presented to account for these variations. The relationship, based on boron chemistry and changes in Gibb's energy, can be stated approximately as Q = a{sub 1}C{sub B}{sup a{sub 2}}Z{sup a{sub 3}} exp[{minus}(a{sub 4}T + a{sub 5}T{sup 2} + a{sub 6}Z{sup 0.5})]. Correlation parameters, which vary with resin type, are evaluated experimentally. Parameter values for macroporous resin Diaion PA 300 and for gel-type resins Diaion SA10 and Amberlite IRN 78LC are presented. The resulting expression is used to determine boron sorption and desorption limitations on ion exchangers at various temperatures and concentrations, and to determine the interfacial boron concentration in equilibrium and rate models.

  12. 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.

  13. The effects of ionizing radiation on Reillex trademark HPQ, a new macroporous polyvinylpyridine resin, and on four conventional polystyrene anion exchange resins

    SciTech Connect

    Marsh, S.F.

    1990-11-01

    This study compares the effects of ionizing radiation on Reillex{trademark} HPQ, a recently available macroporous copolymer of 1-methyl-4-vinylpyridine/divinylbenzene, and on four conventional strong-base polystyrene anion exchange resins. The polystyrene resins investigated included one gel type, Dowex{trademark} 1 {times} 4, and three macroporous resins: Dow{trademark} MSA-1, Amberlite{trademark} IRA-900, and Lewatit{trademark} MP-500-FK. Each resin, in 7 M nitric acid, was subjected to seven different levels of {sup 60}Co gamma radiation ranging from 100 to 1000 megarads. Irradiated resins were measured for changes in dry weight, wet volume, chloride and Pu(IV) exchange capacities, and thermal stability. In separate experiments, each resin was subjected to approximately 340 megarads of in situ alpha particles from sorbed plutonium. Resin damage from alpha particles was less than half that caused by gamma rays, which may be a consequence of different production rates of radiolytic nitrite and nitro radicals in the two systems. Reillex{trademark} HPQ resin provided the greatest radiation stability, whereas Lewatit{trademark} MP-500-FK was the least stable of the resins tested. Thermogravimetric analyses of dry, nitrate-form resin revealed that dry Reillex{trademark} HPQ resin offered the best thermal stability for absorbed gamma doses to 370 megarads, but the worst thermal stability after exposures of 550 megarads or more. 25 refs., 11 figs., 13 tabs.

  14. Improved recovery and purification of plutonium at Los Alamos using macroporous anion exchange resin

    SciTech Connect

    Marsh, S.F.; Mann, M.J.

    1987-05-01

    For almost 30 years, Los Alamos National Laboratory has used anion exchange in nitric acid as the major aqueous process or the recovery and purification of plutonium. One of the few disadvantages of this system is the particularly slow rate at which the anionic nitrato complex of Pu(IV) equilibrates with the resin. The Nuclear Materials Process Technology Group at Los Alamos recently completed an ion exchange development program that focused on improving the slow sorption kinetics that limits this process. A comprehensive investigation of modern anion exchange resins identified porosity and bead size as the properties that most influence plutonium sorption kinetics. Our study found that small beads of macroporous resin produced a dramatic increase in plutonium process efficiency. The Rocky Flats Plant has already adopted this improved ion exchange technology, and it currently is being evaluated for use in other DOE plutonium-processing facilities.

  15. Modeling Ion-Exchange Processing With Spherical Resins For Cesium Removal

    SciTech Connect

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

    2012-09-19

    The spherical Resorcinol-Formaldehyde and hypothetical spherical SuperLig(r) 644 ion-exchange resins are evaluated for cesium removal from radioactive waste solutions. Modeling results show that spherical SuperLig(r) 644 reduces column cycling by 50% for high-potassium solutions. Spherical Resorcinol Formaldehyde performs equally well for the lowest-potassium wastes. Less cycling reduces nitric acid usage during resin elution and sodium addition during resin regeneration, therefore, significantly decreasing life-cycle operational costs. A model assessment of the mechanism behind ''cesium bleed'' is also conducted. When a resin bed is eluted, a relatively small amount of cesium remains within resin particles. Cesium can bleed into otherwise decontaminated product in the next loading cycle. The bleed mechanism is shown to be fully isotherm-controlled vs. mass transfer controlled. Knowledge of residual post-elution cesium level and resin isotherm can be utilized to predict rate of cesium bleed in a mostly non-loaded column. Overall, 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. This evaluation justifies further development of a spherical form of the SL644 resin.

  16. Phenolic cation exchange resin material for recovery of cesium and strontium

    DOEpatents

    Ebra, Martha A.; Wallace, Richard M.

    1983-01-01

    A phenolic cation exchange resin with a chelating group has been prepared by reacting resorcinol with iminodiacetic acid in the presence of formaldehyde at a molar ratio of about 1:1:6. The material is highly selective for the simultaneous recovery of both cesium and strontium from aqueous alkaline solutions, such as, aqueous alkaline nuclear waste solutions. The organic resins are condensation polymers of resorcinol and formaldehyde with attached chelating groups. The column performance of the resins compares favorably with that of commercially available resins for either cesium or strontium removal. By combining Cs.sup.+ and Sr.sup.2+ removal in the same bed, the resins allow significant reduction of the size and complexity of facilities for processing nuclear waste.

  17. Phenolic cation-exchange resin material for recovery of cesium and strontium. [Patent application

    DOEpatents

    Ebra, M.A.; Wallace, R.M.

    1982-05-05

    A phenolic cation exchange resin with a chelating group has been prepared by reacting resorcinol with iminodiacetic acid in the presence of formaldehyde at a molar ratio of about 1:1:6. The material is highly selective for the simultaneous recovery of both cesium and strontium from aqueous alkaline solutions, such as, aqueous alkaline nuclear wate solutions. The organic resins are condensation polymers of resorcinol and formaldehyde with attached chelating groups. The column performance of the resins compares favorably with that of commercially available resins for either cesium or strontium removal. By combining Cs/sup +/ and Sr/sup 2 +/ removal in the same bed, the resins allow significant reduction of the size and complexity of facilities for processing nuclear waste.

  18. 21 CFR 573.120 - Acrylamide-acrylic acid resin.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Acrylamide-acrylic acid resin. 573.120 Section 573... Food Additive Listing § 573.120 Acrylamide-acrylic acid resin. Acrylamide-acrylic acid resin... acrylamide with partial hydrolysis, or by copolymerization of acrylamide and acrylic acid with the...

  19. 21 CFR 573.120 - Acrylamide-acrylic acid resin.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Acrylamide-acrylic acid resin. 573.120 Section 573... Food Additive Listing § 573.120 Acrylamide-acrylic acid resin. Acrylamide-acrylic acid resin... acrylamide with partial hydrolysis, or by copolymerization of acrylamide and acrylic acid with the...

  20. 21 CFR 573.120 - Acrylamide-acrylic acid resin.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Acrylamide-acrylic acid resin. 573.120 Section 573... Food Additive Listing § 573.120 Acrylamide-acrylic acid resin. Acrylamide-acrylic acid resin... acrylamide with partial hydrolysis, or by copolymerization of acrylamide and acrylic acid with the...

  1. 21 CFR 573.120 - Acrylamide-acrylic acid resin.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Acrylamide-acrylic acid resin. 573.120 Section 573... Food Additive Listing § 573.120 Acrylamide-acrylic acid resin. Acrylamide-acrylic acid resin... acrylamide with partial hydrolysis, or by copolymerization of acrylamide and acrylic acid with the...

  2. 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.

  3. Use of Cation Exchange Resins for Production of U{sub 3}O{sub 8} Suitable for the Al-U{sub 3}O{sub 8} Powder Metallurgy Process

    SciTech Connect

    Mosley, W.C.

    2001-09-17

    This report describes the production of U{sub 3}O{sub 8} powders from three types of cation exchange resins: Dowex 50W, a strong acid, sulfonate resin; AG MP-50, a macroporous form of sulfonate resin; and Bio-Rex 70, a weak acid, carboxylic resin.

  4. 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

  5. 21 CFR 176.110 - Acrylamide-acrylic acid resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylamide-acrylic acid resins. 176.110 Section 176... Substances for Use Only as Components of Paper and Paperboard § 176.110 Acrylamide-acrylic acid resins. Acrylamide-acrylic acid resins may be safely used as components of articles intended for use in...

  6. 21 CFR 176.110 - Acrylamide-acrylic acid resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Acrylamide-acrylic acid resins. 176.110 Section... Substances for Use Only as Components of Paper and Paperboard § 176.110 Acrylamide-acrylic acid resins. Acrylamide-acrylic acid resins may be safely used as components of articles intended for use in...

  7. 21 CFR 176.110 - Acrylamide-acrylic acid resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Acrylamide-acrylic acid resins. 176.110 Section... Substances for Use Only as Components of Paper and Paperboard § 176.110 Acrylamide-acrylic acid resins. Acrylamide-acrylic acid resins may be safely used as components of articles intended for use in...

  8. 21 CFR 176.110 - Acrylamide-acrylic acid resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Acrylamide-acrylic acid resins. 176.110 Section... Substances for Use Only as Components of Paper and Paperboard § 176.110 Acrylamide-acrylic acid resins. Acrylamide-acrylic acid resins may be safely used as components of articles intended for use in...

  9. Gamma radiation effect on gas production in anion exchange resins

    NASA Astrophysics Data System (ADS)

    Traboulsi, A.; Labed, V.; Dauvois, V.; Dupuy, N.; Rebufa, C.

    2013-10-01

    Radiation-induced decomposition of Amberlite IRA400 anion exchange resin in hydroxide form by gamma radiolysis has been studied at various doses in different atmospheres (anaerobic, anaerobic with liquid water, and aerobic). The effect of these parameters on the degradation of ion exchange resins is rarely investigated in the literature. We focused on the radiolysis gases produced by resin degradation. When the resin was irradiated under anaerobic conditions with liquid water, the liquid phase over the resin was also analyzed to identify any possible water-soluble products released by degradation of the resin. The main products released are trimethylamine (TMA), molecular hydrogen (H2g) and carbon dioxide (CO2g). TMA and H2g are produced in all the irradiation atmospheres. However, TMA was in gaseous form under anaerobic and aerobic conditions and in aqueous form in presence of liquid water. In the latter conditions, TMAaq was associated with aqueous dimethylamine (DMAaq), monomethylamine (MMAaq) and ammonia (NH). CO2g is formed in the presence of oxygen due to oxidation of organic compounds present in the system, in particular the degradation products such as TMAg.

  10. 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.

  11. Regeneration of strong-base anion-exchange resins by sequential chemical displacement

    SciTech Connect

    Brown, Gilbert M.; Gu, Baohua; Moyer, Bruce A.; Bonnesen, Peter V.

    2002-01-01

    A method for regenerating strong-base anion exchange resins utilizing a sequential chemical displacement technique with new regenerant formulation. The new first regenerant solution is composed of a mixture of ferric chloride, a water-miscible organic solvent, hydrochloric acid, and water in which tetrachloroferrate anion is formed and used to displace the target anions on the resin. The second regenerant is composed of a dilute hydrochloric acid and is used to decompose tetrachloroferrate and elute ferric ions, thereby regenerating the resin. Alternative chemical displacement methods include: (1) displacement of target anions with fluoroborate followed by nitrate or salicylate and (2) displacement of target anions with salicylate followed by dilute hydrochloric acid. The methodology offers an improved regeneration efficiency, recovery, and waste minimization over the conventional displacement technique using sodium chloride (or a brine) or alkali metal hydroxide.

  12. Separation of hemicellulose-derived saccharides from wood hydrolysate by lime and ion exchange resin.

    PubMed

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

    2016-04-01

    A combined process of lime treatment and mixed bed ion exchange was proposed to separate hemicellulose-derived saccharides (HDS) from prehydrolysis liquor (PHL) of lignocellulose as value added products. The optimization of lime treatment achieved up to 44.2% removal of non-saccharide organic compounds (NSOC), mainly colloidal substances, with negligible HDS degradation at 0.5% lime level and subsequent neutralization by phosphoric acid. The residual NSOC and calcium ions in lime-treated PHL were eliminated by mixed bed ion exchange. The breakthrough curves of HDS and NSOC showed selective retention toward NSOC, leading to 75% HDS recovery with 95% purity at 17 bed volumes of exchange capacity. In addition, macroporous resin showed higher exchange capacity than gel resin as indicated by the triple processing volume. The remarkable selectivity of the combined process suggested the feasibility for HDS separation from PHL. PMID:26859331

  13. HIGH ASPECT RATIO ION EXCHANGE RESIN BED - HYDRAULIC RESULTS FOR SPERICAL RESIN BEADS

    SciTech Connect

    Duignan, M; Charles Nash, C; Timothy Punch, T

    2007-09-27

    A principal role of the DOE Savannah River Site is to safely dispose of a large volume of liquid nuclear waste held in many storage tanks. An in-tank ion exchange unit is being considered for cesium removal to accelerate waste processing. This unit is planned to have a relatively high bed height to diameter ratio (10:1). Complicating the design is the need to cool the ion exchange media; therefore, the ion exchange column will have a central cooling core making the flow path annular. To separate cesium from waste the media being considered is made of resorcinol formaldehyde resin deposited on spherical plastic beads and is a substitute for a previously tested resin made of crystalline silicotitanate. This spherical media not only has an advantage of being mechanically robust, but, unlike its predecessor, it is also reusable, that is, loaded cesium can be removed through elution and regeneration. Resin regeneration leads to more efficient operation and less spent resin waste, but its hydraulic performance in the planned ion exchange column was unknown. Moreover, the recycling process of this spherical resorcinol formaldehyde causes its volume to significantly shrink and swell. To determine the spherical media's hydraulic demand a linearly scaled column was designed and tested. The waste simulant used was prototypic of the wastes' viscosity and density. This paper discusses the hydraulic performance of the media that will be used to assist in the design of a full-scale unit.

  14. Anion-exchange resin-based desulfurization process

    SciTech Connect

    Sheth, A.C.; Strevel, S.D.

    1991-01-01

    Under the current grant (FG22-90PC90309), the University of Tennessee Space Institute (UTSI) will carry out the necessary bench scale experiments to further develop it anion-exchange, resin-based desulfurization concept to desulfurize alkali metal sulfates. In particular, it is planned to screen commercially available resins and then carry out process optimization work with three selected resins. Further optimization of the resin regeneration step as well as evaluation of the effect of various performance enhancers will then be carried out with one selected resin. A process schematic, to be developed based on the bench scale results, will be used to estimate the related economics. Some limited scope testing will also be carried out using the spent-seed and sorbent materials obtained from both the coal-fired magnetohydrodynamics (MHD) and the in-duct sorbent injection pilot scale facilities. During this reporting period, 90% of the planned batch mode screening experiments for the eleven samples of candidate resins were completed. Preliminary evaluation of the resulting data is continuing in order to select a smaller number (3--4) of samples for screening in the fixed-bed setup. The installation of the semi-automated fixed-bed setup is about 70% complete and shakedown experiments will be started in 3--4 weeks. Progress made in relation to these activities is presented below. 2 figs., 3 tabs.

  15. Vitrification of cesium-contaminated organic ion exchange resin

    SciTech Connect

    Sargent, T.N. Jr.

    1994-08-01

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

  16. Regeneration of anion exchange resins by catalyzed electrochemical reduction

    DOEpatents

    Gu, Baohua; Brown, Gilbert M.

    2002-01-01

    Anion exchange resins sorbed with perchlorate may be regenerated by a combination of chemical reduction of perchlorate to chloride using a reducing agent and an electrochemical reduction of the oxidized reducing agent. Transitional metals including Ti, Re, and V are preferred chemical reagents for the reduction of perchlorate to chloride. Complexing agents such as oxalate are used to prevent the precipitation of the oxidized Ti(IV) species, and ethyl alcohol may be added to accelerate the reduction kinetics of perchlorate. The regeneration may be performed by continuously recycling the regenerating solution through the resin bed and an electrochemical cell so that the secondary waste generation is minimized.

  17. Denitration of Rocky Flats Ion-Exchange Resins: Recommendation of Denitration Processes, October 19, 1995

    SciTech Connect

    Jacob Espinoza; Mary Barr; Wayne Smith

    1998-12-01

    Resin denitration via anion-exchange is an implementable process that can effectively mitigate the hazards associated with stored resins in which the bulk of the nitrate consists of an "exchangeable nitrate" ionically bound to the cationic sites of the anion-exchange resins. Salicylate has been selected as the exchange anion of choice because of its superior selectivity for the Rocky Flats resins and its unique potential for comprehensive recovery and recycle. This report outlines a single recommended resin denigration procedure that is reasonably independent of the resin composition and the current stored form. This procedure is not optimized but rather seeks to `over-treat' the resins so that a single procedure works for the variety of stored resins. The recommended treatment with sodium salicylate reduces resins by 95-99+% the measured exothermic behavior of the ion-exchange.

  18. Evaluation of ion exchange resins for the removal of dissolved organic matter from biologically treated paper mill effluent.

    PubMed

    Bassandeh, Mojgan; Antony, Alice; Le-Clech, Pierre; Richardson, Desmond; Leslie, Greg

    2013-01-01

    In this study, the efficiency of six ion exchange resins to reduce the dissolved organic matter (DOM) from a biologically treated newsprint mill effluent was evaluated and the dominant removal mechanism of residual organics was established using advanced organic characterisations techniques. Among the resins screened, TAN1 possessed favourable Freundlich parameters, high resin capacity and solute affinity, closely followed by Marathon MSA and Marathon WBA. The removal efficiency of colour and lignin residuals was generally good for the anion exchange resins, greater than 50% and 75% respectively. In terms of the DOM fractions removal measured through liquid chromatography-organic carbon and nitrogen detector (LC-OCND), the resins mainly targeted the removal of humic and fulvic acids of molecular weight ranging between 500 and 1000 g mol(-1), the portion expected to contribute the most to the aromaticity of the effluent. For the anion exchange resins, physical adsorption operated along with ion exchange mechanism assisting to remove neutral and transphilic acid fractions of DOM. The column studies confirmed TAN1 being the best of those screened, exhibited the longest mass transfer zone and maximum treatable volume of effluent. The treatable effluent volume with 50% reduction in dissolved organic carbon (DOC) was 4.8 L for TAN1 followed by Marathon MSA - 3.6L, Marathon 11 - 2.0 L, 21K-XLT - 1.5 L and Marathon WBA - 1.2 L. The cation exchange resin G26 was not effective in DOM removal as the maximum DOC removal obtained was only 27%. The resin capacity could not be completely restored for any of the resins; however, a maximum restoration up to 74% and 93% was achieved for TAN1 and Marathon WBA resins. While this feasibility study indicates the potential option of using ion exchange resins for the reclamation of paper mill effluent, the need for improving the regeneration protocols to restore the resin efficiency is also identified. Similarly, care should be taken

  19. Adsorptive Membranes vs. Resins for Acetic Acid Removal from Biomass Hydrolysates

    SciTech Connect

    Han, B.; Carvalho, W.; Canilha, L.; da Silva, S. S.; e Silva, J. B. A.; McMillan, J. D.; Wickramasinghe, S. R.

    2006-01-01

    Acetic acid is a compound commonly found in hemicellulosic hydrolysates. This weak acid strongly influences the bioconversion of sugar containing hydrolysates. Previous investigators have used anion exchange resins for acetic acid removal from different hemicellulosic hydrolysates. In this study, the efficiency of an anion exchange membrane was compared to that of an anion exchange resin, for acetic acid removal from a DI water solution and an acidic hemicellulose hydrolysate pretreated using two different methods. Ion exchange membranes and resins have very different geometries. Here the performance of membranes and resins is compared using two dimensionless parameters, the relative mass throughput and chromatographic bed number. The relative mass throughput arises naturally from the Thomas solution for ion exchange. The results show that the membrane exhibit better performance in terms of capacity, and loss of the desired sugars. In addition acetic acid may be eluted at a higher concentration from the membrane thus leading to the possibility of recovery and re-use of the acetic acid.

  20. Activation product behavior on borated mixed-bed ion exchange resin

    SciTech Connect

    Kudera, D.E.

    1981-01-01

    The Loss-of-Fluid Test (LOFT) Facility uses two separate mixed-bed ion exchange systems to decontaminate solutions. The radioactive solutions to be decontaminated are demineralized water containing boric acid (500 to 3500 ppM B) and lithium hydroxide (approx. 1 ppM Li). Many activation products are formed during nuclear operation. This paper describes the capability of the mixed cation-anion (Li-OH) type resin to remove these activation products from solution. Problems in measuring decontamination factors (DF) are discussed. The tendency of certain isotopes to give early indication of resin exhaustion is shown. Typical DF (ratio of before-ion-exchange concentration to after-ion-exchange concentration) have been determined for 22 different isotopes in the LOFT purification systems.

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

    NASA Astrophysics Data System (ADS)

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

    1998-10-01

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

  2. 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)

  3. Cesium Ion Exchange Loading Kinetics Testing with SRF Resin

    SciTech Connect

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

    2012-11-02

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

  4. Fractionation of sulphite spent liquor for biochemical processing using ion exchange resins.

    PubMed

    Fernandes, D L A; Silva, C M; Xavier, A M R B; Evtuguin, D V

    2012-12-31

    Sulphite spent liquor (SSL) is a side product from acidic sulphite pulping of wood, which organic counterpart is composed mainly by lignosulphonates (LS) and sugars. The last are a prominent substrate for the bioprocessing although a previous purification step is necessary to eliminate microbial inhibitors. In this study a fractionation of hardwood SSL (HSSL) has been accomplished employing ion exchange resins in order to separate sugars fraction from concomitant inhibitors: LS, acetic acid, furan derivatives, phenolics, acetic acid and excess of inorganic salts. The fractionation of HSSL has been carried out using two fixed-bed ion exchangers in series (cationic+anionic). The first cation exchange column packed with Dowex 50WX2 resin was able to eliminate free cations and partially separate sugars from high molecular weight LS and furan derivatives. The second anion exchange column packed with Amberlite IRA-96 sorbed remaining LS, phenolics and acetic acid. Overall, the series arrangement under investigation has removed 99.99% of Mg(2+), 99.0% of Ca(2+), 99.6% of LS, and 100% of acetic acid, whereas the yield of recovered sugars was at least 72% of their total amount in HSSL. PMID:22465600

  5. Technical Task and Quality Assurance Plan in Support of BNFL Part B: Studies of Ion Exchange Resin Integrity under Flowsheet Extremes: Part II

    SciTech Connect

    Nash, C.A.

    2000-08-23

    This task will address four items related to ion exchange stability: (1) process upset evaluation of resin in contact with 1 molar sodium permanganate at 25 and 40 degrees C, (2) accelerated aging with nitric acid solution used during normal regeneration operations, (3) prolonged contacting of SuperLig 644 resin with 5 molar nitric acid at room temperature, and (4) prolonged contacting of SuperLig 644 resin with deionized water at 60 plus/minus 5 degrees C.

  6. Evaluating ion exchange resin efficiency and oxidative capacity for the separation of uranium(IV) and uranium(VI)

    PubMed Central

    2013-01-01

    Background Previously described methods to separate dissolved U(IV) from dissolved U(VI) under acidic anoxic conditions prior to laboratory analysis were ineffective with materials currently available commercially. Three strong anion exchange resins were examined for their efficiency in separating, recovering, and preserving both redox states during separation. Results Under oxic conditions, recovery of U(VI) from three exchange resins (Bio-Rad AG® 1x8 Poly-Prep® prefilled columns, Bio-Rad AG® 1x8 powder, and Dowex® 1x8 powder) ranged from 72% to 100% depending on the dosed mass, eluent volume, and resin selected. Dowex® 1x8 resin was the only resin found to provide 100% recovery of U(VI) with fewer than 5 bed volumes of eluent. Under anoxic conditions, all three resins oxidized U(IV) in aqueous solutions with relatively low U(IV) concentrations (<3x10-6 M). Resin-induced oxidation was observed visually using a leuco dye, safranin-o. Oxidants associated with the resin were irreversibly reduced by the addition of Ti(III). After anoxic resin pre-treatment, a series of U(IV)/U(VI) mixtures at micro-molar levels were prepared and separated using the Dowex® 1x8 resin with 100% recovery of both U(IV) and U(VI) with no resin-induced changes in oxidation state. Conclusions Currently available anion exchange resins with apparently identical physical properties were found to have significantly different recoveries for hexavalent uranium at micro-molar concentrations. A novel qualitative technique was developed to visually assess oxidative capacities of anion exchange resins under acidic anoxic conditions. A protocol was developed for pre-treatment and use of currently available anion exchange resins to achieve quantitative separation of U(IV) and U(VI) in aqueous solutions with low U(IV) concentrations. This method can be applied to future work to quantitatively assess dissolved U(IV) and U(VI) concentrations in both laboratory and field samples. PMID:23363052

  7. High throughput determination of cleaning solutions to prevent the fouling of an anion exchange resin.

    PubMed

    Elich, Thomas; Iskra, Timothy; Daniels, William; Morrison, Christopher J

    2016-06-01

    Effective cleaning of chromatography resin is required to prevent fouling and maximize the number of processing cycles which can be achieved. Optimization of resin cleaning procedures, however, can lead to prohibitive material, labor, and time requirements, even when using milliliter scale chromatography columns. In this work, high throughput (HT) techniques were used to evaluate cleaning agents for a monoclonal antibody (mAb) polishing step utilizing Fractogel(®) EMD TMAE HiCap (M) anion exchange (AEX) resin. For this particular mAb feed stream, the AEX resin could not be fully restored with traditional NaCl and NaOH cleaning solutions, resulting in a loss of impurity capacity with resin cycling. Miniaturized microliter scale chromatography columns and an automated liquid handling system (LHS) were employed to evaluate various experimental cleaning conditions. Cleaning agents were monitored for their ability to maintain resin impurity capacity over multiple processing cycles by analyzing the flowthrough material for turbidity and high molecular weight (HMW) content. HT experiments indicated that a 167 mM acetic acid strip solution followed by a 0.5 M NaOH, 2 M NaCl sanitization provided approximately 90% cleaning improvement over solutions containing solely NaCl and/or NaOH. Results from the microliter scale HT experiments were confirmed in subsequent evaluations at the milliliter scale. These results identify cleaning agents which may restore resin performance for applications involving fouling species in ion exchange systems. In addition, this work demonstrates the use of miniaturized columns operated with an automated LHS for HT evaluation of chromatographic cleaning procedures, effectively decreasing material requirements while simultaneously increasing throughput. Biotechnol. Bioeng. 2016;113: 1251-1259. © 2015 Wiley Periodicals, Inc. PMID:26552005

  8. Controlled methyl-esterification of pectin catalyzed by cation exchange resin.

    PubMed

    Peng, Xiaoxia; Yang, Guang; Fan, Xingchen; Bai, Yeming; Ren, Xiaomeng; Zhou, Yifa

    2016-02-10

    This study developed a new method to methyl-esterify pectin using a cation exchange resin. Homogalacturonan (HG)-type pectin (WGPA-3-HG) and rhamnogalacturonan (RG)-I-type pectin (AHP-RG) obtained from the roots of Panax ginseng and sunflower heads, respectively, were used as models. Compared to commonly used methyl-esterification methods that use either methyl iodide or acidified methanol, the developed method can methyl-esterify both HG- and RG-I-type pectins without degrading their structures via β-elimination or acid hydrolysis. In addition, by modifying reaction conditions, including the mass ratio of resin to pectin, reaction time, and temperature, the degree of esterification can be controlled. Moreover, the resin and methanol can be recycled to conserve resources, lower costs, and reduce environmental pollution. This new methodology will be highly useful for industrial esterification of pectin. PMID:26686175

  9. Ion exhange and molecular sorption of oxalic acid with a highly basic anion exchanger

    NASA Astrophysics Data System (ADS)

    Krisilova, E. V.; Oros, G. Yu.; Krisilov, A. V.; Selemenev, V. F.

    2014-04-01

    Ab initio modeling of a matrix fragment of resin and geometry optimization of the molecular structure of oxalic acid were performed. The isotherm of oxalic acid sorption with AV-17-8 anion exchange resin was obtained by the variable concentrations technique. The ion-exchange and molecular components of sorbate fixation with the ion exchanger were determined. The hydration of the highly basic anion exchanger that absorbed different quantities of dicarboxylic acid was evaluated by the centrifuging method. The dependence of the amount of water and sorbate concentration in the resin was linear antibatic.

  10. Qualification of Reillex{trademark} HPQ anion exchange resin for use in SRS processes

    SciTech Connect

    Crooks, W.J. III

    2000-05-18

    The Phase 2 portion of the HB-Line facility was built in the early 1980's to process plutonium and neptunium from nitric acid solutions into oxide suitable for storage in a vault. Although the other portions of HB-Line were started up in the mid 1980's and have operated since that time, the anion exchange and precipitation processes in Phase 2 were never started up. As part of the material stabilization efforts, Phase 2 is currently being started up. A new anion exchange resin is needed because the resins that were proposed for use 10 years ago are limited by performance characteristics, disposal requirements, or are no longer commercially available. SRTC is responsible for qualifying all resins prior to their use in Nuclear Materials Stabilization and Storage (NMSS) processes. Qualification consists of both process suitability and thermal stability with nitric acid. This report describes the thermal stability qualification of Reillex{trademark} HPQ, the new resin proposed for processing plutonium and neptunium in the HB Line facility.

  11. Ion Exchange Testing with SRF Resin FY2012

    SciTech Connect

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

    2013-06-11

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

  12. Cation immobilization in pyrolyzed simulated spent ion exchange resins

    NASA Astrophysics Data System (ADS)

    Luca, Vittorio; Bianchi, Hugo L.; Manzini, Alberto C.

    2012-05-01

    Significant quantities of spent ion exchange resins that are contaminated by an assortment of radioactive elements are produced by the nuclear industry each year. The baseline technology for the conditioning of these spent resins is encapsulation in ordinary Portland cement which has various shortcomings none the least of which is the relatively low loading of resin in the cement and the poor immobilization of highly mobile elements such as cesium. The present study was conducted with cationic resin samples (Lewatit S100) loaded with Cs+, Sr2+, Co2+, Ni2+ in roughly equimolar proportions at levels at or below 30% of the total cation exchange capacity. Low temperature thermal treatment of the resins was conducted in inert (Ar), or reducing (CH4) gas atmospheres, or supercritical ethanol to convert the hydrated polymeric resin beads into carbonaceous materials that contained no water. This pyrolytic treatment resulted in at least a 50% volume reduction to give mechanically robust spherical materials. Scanning electron microscope investigations of cross-sections of the beads combined with energy dispersive analysis showed that initially all elements were uniformly distributed through the resin matrix but that at higher temperatures the distribution of Cs became inhomogeneous. Although Cs was found in the entire cross-section, a significant proportion of the Cs occurred within internal rings while a proportion migrated toward the outer surfaces to form a crustal deposit. Leaching experiments conducted in water at 25 °C showed that the divalent contaminant elements were very difficult to leach from the beads heated in inert atmospheres in the range 200-600 °C. Cumulative fractional loses of the order of 0.001 were observed for these divalent elements for temperatures below 500 °C. Regardless of the processing temperature, the cumulative fractional loss of Cs in water at 25 °C reached a plateau or steady-state within the first 24 h increasing only marginally up 120 h

  13. 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.

  14. 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.

  15. Removal of perfluorooctane sulfonate from wastewater by anion exchange resins: effects of resin properties and solution chemistry.

    PubMed

    Deng, Shubo; Yu, Qiang; Huang, Jun; Yu, Gang

    2010-10-01

    Perfluorooctane sulfonate (PFOS) is a new persistent organic pollutant of substantial environmental concern, and its removal from industrial wastewater is critical to eliminate its release into water environment. In this paper, six anion exchange resins with different polymer matrix, porosity, and functional group were evaluated for PFOS removal from simulated wastewater. Resin matrix displayed significant effect on the sorption kinetics and capacity of PFOS, and the polyacrylic resins including IRA67 and IRA958 exhibited faster sorption and higher sorption capacity for PFOS than the polystyrene resins due to the hydrophilic matrix. Sorption isotherms illustrated that the sorption capacity of PFOS on IRA67 and IRA958 was up to 4-5 mmol/g, and the amount of PFOS sorbed on the resins was more than chloride released from resins, indicating that other interactions besides anion exchange were involved in the sorption. Solution pH had little impact on the sorption of PFOS on IRA958, but displayed significant effect on IRA67 at pH above 10 due to the deprotonation of amine groups. The coexisting sulfate and hexavalent chromium in wastewater interfered with the sorption of PFOS because of their competitive sorption on the exchange sites. The spent resins were successfully regenerated using the mixture of NaCl and methanol solution. This work provided an understanding of sorption behavior and mechanism of PFOS on different anion exchange resins, and should result in more effective applications of ion exchange for PFOS removal from industrial wastewater. PMID:20605036

  16. Quaternized agricultural by-products as anion exchange resins.

    PubMed

    Wartelle, Lynda H; Marshall, Wayne E

    2006-01-01

    The objectives of this study were the chemical modification of readily available, low-cost agricultural by-products to anion exchange resins and the selection of the best modified by-product for further use in anion removal. Resins were prepared through the quaternization of a series of 12 agricultural by-products with N-(3-chloro-2-hydroxypropyl) trimethylammonium chloride (CHMAC). Phosphate ion adsorption assays were conducted at pH 7 in order to compare adsorption properties among the by-products. Quaternized corn stover showed the highest phosphorus adsorption at 0.66 mmole/g. Since corn stover exhibited the best uptake of phosphate ion, it was compared to a commercially available, cellulose-based anion exchange resin. Additionally, adsorption capacities of quaternized corn stover for arsenate, chromate, and selenate were evaluated and adsorption efficiencies were determined in simulated wastewater samples. Our results indicate that modified corn stover demonstrates good adsorption uptake for arsenate and selenate and especially for chromate. PMID:16144735

  17. Assessment of cadmium in aquatic sediment using dialysis samplers with ion-exchange-resin collection

    SciTech Connect

    Shi, B.; Allen, H.E.; Desnoyers, C.

    1998-05-01

    Simultaneously extracted metals (SEM) and acid volatile sulfide (AVS) show the potential for toxicity on the basis of their ratio. Accordingly, the authors spiked cadmium in a range for which Cd/AVS ratios were from 0.2 to 10 in the sediment with its weight about 8 kg in each batch. Dialysis samplers with a cation ion-exchange resin (Dowex 50W-X4) collection were used in a laboratory for the determination of free cadmium concentrations in pore water of the collected sediment. When equilibrium was reached among cadmium in pore water, sediment, and ion-exchange resin, cadmium exchanged onto resin phase was regenerated with 1 N hydrochloric acid (OPTIMA grade) and determined using an atomic absorption spectrophotometer (Zeeman 5000) with a graphite furnace accessory. Cadmium determined using the dialysis sampler is considered as free cadmium which is related to the metal bioavailability toward aquatic biota. The developed methodology provides a new technique for assessment of free metal in aquatic sediment systems.

  18. 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

  19. Evaluation of chelating ion-exchange resins for separating Cr(III) from industrial effluents.

    PubMed

    Cavaco, Sofia A; Fernandes, Sandra; Augusto, Cátia M; Quina, Margarida J; Gando-Ferreira, Licínio M

    2009-09-30

    In this study two chelating resins containing iminodiacetic acid groups (Amberlite IRC 748 and Diaion CR 11) and a chelating resin based on sulfonic and diphosphonic acid groups (Diphonix) were investigated in order to separate Cr(III) from industrial effluents produced in hard and decorative electroplating. Samples of two industrial plants were characterized during a period of about one year and a half in terms of the metals content (Cr, Cu, Na, Ca, Fe and Ni), Total Suspended Solids (TSS), Total Dissolved Solids (TDS), Chemical Oxygen Demand (COD) and pH. Some of the physical properties of the resins, namely the moisture content, apparent density, intraparticle porosity and the particle size distribution were also evaluated. To quantify the sorption capacity of the resins, batch experiments were performed using synthetic solutions of Cr(III), as well as solutions of Fe in the case of Diphonix. The Langmuir and Langmuir-Freundlich isotherms enabled a good description of the ion-exchange equilibrium data, and the maximum sorption capacity determined for Amberlite and Diaion was 3.6 mequiv./g(dry resin). For Diphonix that parameter was 3.4 mequiv./g(dry resin). The Diphonix resin exhibits a high selectivity for transition metals (Fe, Ni) over the chromium trivalent. Therefore, it was screened as the most suitable for selectively removing those metal impurities from chromium electroplating effluents. For this resin, the sorption capacity is strongly dependent on the initial pH of the solution. Though, high regeneration efficiencies of Diphonix for stripping Cr(III) were found by using a mixture of NaOH/H(2)O(2). The mathematical model tested for describing the dynamics of the process allowed a good fitting to the experimental data and enabled the estimation of effective pore diffusivity of Cr(III). The saturations of Diphonix with industrial effluents demonstrated that the breakthrough capacity of the resin is affected by the presence of other species in solution

  20. Methylene crosslinked calix[6]arene hexacaarboxylic acid resin: a highly efficient solid phase extractant for decontamination of lead bearing effluents.

    PubMed

    Adhikari, Birendra Babu; Gurung, Manju; Kawakita, Hidetaka; Jumina; Ohto, Keisuke

    2011-10-15

    Calixarene-based cation exchange resin has been developed by methylene crosslinking of calix[6]arene hexacarboxylic acid derivative and the resin has been exploited for solid phase extraction of some toxic heavy metal ions. The selectivity order of the resin towards some metal ions follows the order Pb(II) > Cu(II)> Zn(II), Ni(II), Co(II). The maximum lead ion binding capacity of the resin was found to be 1.30 mmol g(-1) resin. The loaded lead was quantitatively eluted with dilute acid solution regenerating the resin. Mutual separation of Pb(II), Cu(II) and Zn(II) was achieved by using the column packed with the resin. PMID:21835544

  1. Recovery of uranium from acid media by macroporous bifunctional phosphinic acid resin

    SciTech Connect

    Sabharwal, K.N.; Srinivasan, T.G.; Rao, P.R.V.; Nandy, K.K.

    1996-11-01

    The extraction of uranium from various acid media such as nitric acid, sulphuric acid, hydrochloric acid, phosphoric acid and perchloric acid by a macroporous bifunctional phosphinic acid resin (MPBPA) has been studied. The distribution coefficients for the extraction of uranium by the MPBPA resin are compared with the corresponding values reported in literature for the conventional sulphonic acid resin. The results clearly indicate the suitability of the MPBPA resin to recover uranium from different types of acid solutions of widely ranging acidities. 17 refs., 6 figs., 5 tabs.

  2. 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.)

  3. An investigation of the applicability of the new ion exchange resin, Reillex{trademark}-HPQ, in ATW separations. Milestone 4, Final report

    SciTech Connect

    Ashley, K.R.; Ball, J.; Grissom, M.; Williamson, M.; Cobb, S.; Young, D.; Wu, Yen-Yuan J.

    1993-09-07

    The investigations with the anion exchange resin Reillex{trademark}-HPQ is continuing along several different paths. The topics of current investigations that are reported here are: The sorption behavior of chromium(VI) on Reillex{trademark}-HPQ from nitric acid solutions and from sodium hydroxide/sodium nitrate solutions; sorption behavior of F{sup {minus}} on Reillex{trademark}-HPQ resin in acidic sodium nitrate solution; sorption behavior of Cl{sup {minus}} on Reillex{trademark}-HPQ resin in acidic sodium nitrate solution; sorption behavior of Br{sup {minus}} on Reillex{trademark}-HPQ resin in acidic sodium nitrate solution; and the Honors thesis by one of the students is attached as Appendix II (on ion exchange properties of a new macroperous resin using bromide as the model ion in aqueous nitrate solutions).

  4. The use of Diphonix{sup {trademark}} ion exchange resin as a preconcentration step for the lanthanides and actinides in analytical applications

    SciTech Connect

    Rollins, A.N.; Thakkar, A.H.; Fern, M.J.

    1995-12-01

    Diphonix ion exchange resin is a chelating ion exchange resin containing sulfonic and gemdiphosphonic acid groups. This resin has a high specificity for the lanthanides and actinides, especially at acidities below pH = 3. Currently, we are investigating new ways to use Diphonix resin as a preconcentration step to separate the lanthanides and actinides from interfering elements present in a variety of environmental matrices. Once the lanthanides and actinides have been separated from the interfering matrix constituents, the elements are removed from the resin and passed through subsequent separation schemes. This presentation will outline the use of Diphonix resin with a variety of problem matrices, and demonstrate its usefulness for analysis of the lanthanides and actinides.

  5. Ion exchange of Th(IV), U(VI), and Pu(IV) on macroreticular resins in TBP-Shell Sol-T solutions

    SciTech Connect

    Mayankutty, P.C.; Jangida, B.L.; Sundaresan, M.

    1982-01-01

    Absorption of thorium, uranium, and plutonium by macroreticular cation and anion exchange resins from solutions of TBP in Shell Sol-T as a function of TBP and HNO/sub 3/ concentrations in the organic phase has been investigated.The absorption behavior is compared with that on conventional gel-type resins from TBP medium on the one-hand and on macroreticular resins from aqueous nitric acid on the other.

  6. Ion Exchange Testing with SRF Resin FY 2012

    SciTech Connect

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

    2014-07-02

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

  7. Purification Or Organic Acids Using Anion Exchange Chromatography.

    DOEpatents

    Ponnampalam; Elankovan

    2001-09-04

    Disclosed is a cost-effective method for purifying and acidifying carboxylic acids, including organic acids and amino acids. The method involves removing impurities by allowing the anionic form of the carboxylic acid to bind to an anion exchange column and washing the column. The carboxylic anion is displaced as carboxylic acid by washing the resin with a strong inorganic anion. This method is effective in removing organic carboxylic acids and amino acids from a variety of industrial sources, including fermentation broths, hydrolysates, and waste streams.

  8. Removal of CdTe in acidic media by magnetic ion-exchange resin: a potential recycling methodology for cadmium telluride photovoltaic waste.

    PubMed

    Zhang, Teng; Dong, Zebin; Qu, Fei; Ding, Fazhu; Peng, Xingyu; Wang, Hongyan; Gu, Hongwei

    2014-08-30

    Sulfonated magnetic microspheres (PSt-DVB-SNa MPs) have been successfully prepared as adsorbents via an aqueous suspension polymerization of styrene-divinylbenzene and a sulfonation reaction successively. The resulting adsorbents were confirmed by means of Fourier transform infrared spectra (FT-IR), X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope equipped with an energy dispersive spectrometer (SEM-EDS) and vibrating sample magnetometer (VSM). The leaching process of CdTe was optimized, and the removal efficiency of Cd and Te from the leaching solution was investigated. The adsorbents could directly remove all cations of Cd and Te from a highly acidic leaching solution of CdTe. The adsorption process for Cd and Te reached equilibrium in a few minutes and this process highly depended on the dosage of adsorbents and the affinity of sulfonate groups with cations. Because of its good adsorption capacity in strong acidic media, high adsorbing rate, and efficient magnetic separation from the solution, PSt-DVB-SNa MPs is expected to be an ideal material for the recycling of CdTe photovoltaic waste. PMID:25128764

  9. Evaluation and application of anion exchange resins to measure groundwater uranium flux at a former uranium mill site.

    PubMed

    Stucker, Valerie; Ranville, James; Newman, Mark; Peacock, Aaron; Cho, Jaehyun; Hatfield, Kirk

    2011-10-15

    Laboratory tests and a field validation experiment were performed to evaluate anion exchange resins for uranium sorption and desorption in order to develop a uranium passive flux meter (PFM). The mass of uranium sorbed to the resin and corresponding masses of alcohol tracers eluted over the duration of groundwater installation are then used to determine the groundwater and uranium contaminant fluxes. Laboratory based batch experiments were performed using Purolite A500, Dowex 21K and 21K XLT, Lewatit S6328 A resins and silver impregnated activated carbon to examine uranium sorption and extraction for each material. The Dowex resins had the highest uranium sorption, followed by Lewatit, Purolite and the activated carbon. Recoveries from all ion exchange resins were in the range of 94-99% for aqueous uranium in the environmentally relevant concentration range studied (0.01-200 ppb). Due to the lower price and well-characterized tracer capacity, Lewatit S6328 A was used for field-testing of PFMs at the DOE UMTRA site in Rifle, CO. The effect on the flux measurements of extractant (nitric acid)/resin ratio, and uranium loading were investigated. Higher cumulative uranium fluxes (as seen with concentrations>1 ug U/gram resin) yielded more homogeneous resin samples versus lower cumulative fluxes (<1 ug U/gram resin), which caused the PFM to have areas of localized concentration of uranium. Resin homogenization and larger volume extractions yield reproducible results for all levels of uranium fluxes. Although PFM design can be improved to measure flux and groundwater flow direction, the current methodology can be applied to uranium transport studies. PMID:21798572

  10. 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.

  11. Use of ion exchange resins in the analysis of rocks and minerals: Separation of sodium and potassium

    USGS Publications Warehouse

    Reichen, L.E.

    1958-01-01

    This procedure was developed primarily for analyses in which limited amounts of sample are available. Sodium and potassium can be separated from the other constituents of silicate rocks by cation exchange resin (Amberlite IR-120). The sample is decomposed with hydrofluoric and sulfuric acids and passed through the resin bed after expulsion of the fluorine. The column is eluted with 0.12N hydrochloric acid at a fast flow rate of 4 ml. per sq. cm. per minute and the sodium and potassium are recovered together within a reasonable time. Other constituents of the sample, except silica, can be determined on the same portion of sample.

  12. Cation exchange resin immobilized bimetallic nickel-iron nanoparticles to facilitate their application in pollutants degradation.

    PubMed

    Ni, Shou-Qing; Yang, Ning

    2014-04-15

    Nanoscale zerovalent iron (nZVI) usually suffers from reduction of reactivity by aggregation, difficulty of assembling, environmental release and health concerns. Furthermore, data are lacking on the effect of cheap nickel on debromination of decabromodiphenyl ether (DBDE) by immobilized nZVI in aqueous system. In this study, strong acid polystyrene cation-exchange resins with particle diameter from 0.4 to 0.6 mm were utilized as matrices to immobilize bimetallic nickel-iron nanoparticles in order to minimize aggregation and environmental leakage risks of nZVI and to enhance their reactivity. Elemental distribution mapping showed that iron particles distributed uniformly on the surface of the resin and nickel particles were dispersed homogeneously into Fe phase. The reaction rate of resin-bound nZVI is about 55% higher than that of dispersed nZVI. The immobilized bimetallic nanoparticles with 9.69% Ni had the highest debromination percent (96%) and reaction rate (0.493 1/h). The existence of Ni significantly improved the debromination rate, due to the surface coverage of catalytic metal on the reductive metal and the formation of a galvanic cell. The environmental dominant congeners, such as BDE 154, 153, 100, 99 and 47, were produced during the process. Outstanding reactive performance, along with magnetic separation assured that resin-bound bimetallic nickel-iron nanoparticles are promising material that can be utilized to remediate a wide variety of pollutants contaminated sites including polybrominated diphenyl ethers. PMID:24559714

  13. 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.)

  14. 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)

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

    SciTech Connect

    Rideaux, J.

    1999-03-08

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

  16. Porous metal oxide microspheres from ion exchange resin

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

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

  17. Separation of Molybdenum-Uranium by a Process Combining Ion Exchange Resin and Membranes

    NASA Astrophysics Data System (ADS)

    Lounis, A.; Setti, L.; Djennane, A.; Melikchi, R.

    The purpose of this study is to determine whether the electrodeionization with ion-exchange resin is suitable for removing uranium from a solution containing molybdenum. A hybrid process combining ion exchange (resins and membranes) using electric current. For this electroextraction process, the cation exchange resin is introduced into an electrodialysis cell and compressed between two cations exchange membranes. We have investigated a continuous electroextraction process. As important result we note that: The factor of selectivity,r, for molybdenum versus uranium is superior to 3; the concentration in radio active element (U3O8) is lower than 1.5 mg L-1 and small cell voltage is observed.

  18. Novel simple process for tocopherols selective recovery from vegetable oils by adsorption and desorption with an anion-exchange resin.

    PubMed

    Hiromori, Kousuke; Shibasaki-Kitakawa, Naomi; Nakashima, Kazunori; Yonemoto, Toshikuni

    2016-03-01

    A novel and simple low-temperature process was used to recover tocopherols from a deodorizer distillate, which is a by-product of edible oil refining. The process consists of three operations: the esterification of free fatty acids with a cation-exchange resin catalyst, the adsorption of tocopherols onto an anion-exchange resin, and tocopherol desorption from the resin. No degradation of tocopherols occurred during these processes. In the tocopherol-rich fraction, no impurities such as sterols or glycerides were present. These impurities are commonly found in the product of the conventional process. This novel process improves the overall recovery ratio and the mass fraction of the product (75.9% and 51.0wt%) compared with those in the conventional process (50% and 35wt%). PMID:26471519

  19. Removal of chlorophenols from aqueous solution by anion-exchange resins

    SciTech Connect

    Kuen-Chyr Lee; Young Ku

    1996-11-01

    The effects of pH value and chloride ion concentration in the removal of chlorophenols from aqueous solutions by Purolite A-510 resin [macroreticular polystyrene-divinylbenzene resin with R(CH{sub 3}){sub 2}(C{sub 2}H{sub 4}OH)N{sup +} group] are discussed by the species distributions of chlorophenols. Those chlorophenols include phenol, 2-chlorophenol, 2,4-dichlorophenol, and 2,4,6-trichlorophenol. The investigations showed that the chlorophenols could be removed effectively at alkaline conditions where the ion-exchange reaction was dominant. Also, the removal of chlorophenols increased with the number of chlorine atoms on the chlorophenols. The removal of chlorophenols via the ion-exchange reaction was hindered by the presence of chloride ions. The effect of chloride ions, however, was diminished in acidic solutions where the adsorption reaction was dominant. The proposed equilibrium model, which considers both adsorption and ion-exchange reactions, adequately describes the sorption behavior of chlorophenols. The partition constants of the protonated chlorophenols can be estimated from the octanol/water partition coefficients of the phenolic compounds.

  20. 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

  1. Synthesis of biodiesel from pongamia oil using heterogeneous ion-exchange resin catalyst.

    PubMed

    Jaya, N; Selvan, B Karpanai; Vennison, S John

    2015-11-01

    Biodiesel is a clean-burning renewable substitute fuel for petroleum. Biodiesel could be effectively produced by transesterification reaction of triglycerides of vegetable oils with short-chain alcohols in the presence of homogeneous or heterogeneous catalysts. Conventionally, biodiesel manufacturing processes employ strong acids or bases as catalysts. But, separation of the catalyst and the by-product glycerol from the product ester is too expensive to justify the product use as an automobile fuel. Hence heterogeneous catalysts are preferred. In this study, transesterification of pongamia oil with ethanol was performed using a solid ion-exchange resin catalyst. It is a macro porous strongly basic anion exchange resin. The process parameters affecting the ethyl ester yield were investigated. The reaction conditions were optimized for the maximum yield of fatty acid ethyl ester (FAEE) of pongamia oil. The properties of FAEE were compared with accepted standards of biodiesel. Engine performance was also studied with pongamia oil diesel blend and engine emission characteristics were observed. PMID:26254204

  2. 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.

  3. Effects of Gamma Radiation on Individual and Mixed Ion Exchange Resins

    SciTech Connect

    Baumann, E.W.

    2003-01-06

    The ion exchange resins that are used to deionize moderator in the reactor purification systems may accumulate sufficient radiation dose to damage the resins. This radiation damage would be manifested by: (1) loss of useful exchange capacity of the bed, which is costly since resins from the reactor deionizers are not reused; (2) shrinking or swelling of the resins, which may have some effect on the hydraulic behavior of the beds; (3) release of resin degradation products into the process stream, which pollutes moderator with impurities and precursors of the neutron-induced radioisotopes. This document details results of a laboratory study to determine the magnitude of these three effects by gamma irradiation of individual resins and their mixtures.

  4. An investigation of the radiolytic stability of a resorcinol- formaldehyde ion exchange resin

    SciTech Connect

    Crawford, C.L.; Bibler, N.E.; Bibler, J.P.

    1993-12-31

    Radiolytic stability of a resorcinol-formaldehyde polycondensation-type cation exchange resin was investigated for up to lE09 rads total dose. The resorcinol-formaldehyde resin is a resin that has potential cesium decontamination applications at Pacific Northwest and Savannah River. We have determined both radiation and storage effects on performance of the resin using 101-AW Hanford simulant and ASTM Type-I water. Distribution coefficient determinations, total carbon analysis, and physical observations lead us to conclude that radiation up to lE08 rads does not significantly affect the performance of the resin. The resin is more stable to radiation in water than in 101-AW Hanford simulant. Also radiation or storage does not affect the thermal stability of the resin. Gas production rates for several resin slurries increased in the order of resin/101-AW Hanford simulant, resin/ASTM water, and resin/0.5 M HNO{sub 3}. H{sub 2} is produced from radiolysis of resin in 101-AW Hanford simulant with a G value of G(H{sub 2}) of 0.11 {plus_minus} 0.02 molecules/100eV and in 0.5 M HNO{sub 3} with a G value of G(H{sub 2}) of 0.27 {plus_minus} 0.02 molecules/lOOeV.

  5. Deuterium isotopic exchangeability of resin and amber at low thermal stress under hydrous conditions

    NASA Astrophysics Data System (ADS)

    Gonzalez, G.; Tappert, R.; Wolfe, A. P.; Muehlenbachs, K.

    2012-04-01

    Hydrous deuterium-exchange experiments have shown that a significant fraction of the original D/H composition of bulk kerogens, bitumens and expelled oils may participate in isotopic exchange reactions during burial diagenesis. However, it is unknown to what extent plant-derived secondary metabolites, namely resins and their fossil counterpart amber, exchange hydrogen isotopes following their biosynthesis. This situation hinders the application of resin D/H measurements in paleoenvironmental reconstruction. Here, we assess explicitly hydrogen exchange in resins and ambers using a series of immersion experiments in deuterated (D-enriched) waters over a period of several months at several temperatures. We are especially interested in assessing whether significant H-isotopic exchange occurs between resins and meteoric waters during early thermal maturation and polymerization. At 90°C, equivalent to ~3km of burial in most diagenetic regimes, modern conifer and angiosperm resins have an average post-metabolic H exchange of 4.6%, compared to only 1.1% for mature, polymerized ambers. At 55°C the degree of exchange is considerably lower: 1.9% for resins and 0.6% for ambers. These results indicate that most D/H isotopic exchange occurs prior to polymerization reactions, thereby confirming that D/H measurements from amber constitute a potentially sensitive proxy for environmental change.

  6. Uranium Adsorption on Ion-Exchange Resins - Batch Testing

    SciTech Connect

    Mattigod, Shas V.; Golovich, Elizabeth C.; Wellman, Dawn M.; Cordova, Elsa A.; Smith, Ronald M.

    2010-12-01

    The uranium adsorption performance of five resins (Dowex 1, Dowex 21K 16-30 [fresh], Dowex 21K 16-30 [regenerated], Purofine PFA600/4740, and ResinTech SIR-1200) were tested using unspiked, nitrate-spiked, and nitrate-spiked/pH adjusted source water from well 299-W19-36. These batch tests were conducted in support of a resin selection process in which the best resin to use for uranium treatment in the 200-West Area groundwater pump-and-treat system will be identified. The results from these tests are as follows: • The data from the high-nitrate (1331 mg/L) tests indicated that Dowex 1, Dowex 21K 16-30 (fresh), Purofine PFA600/4740, and ResinTech SIR-1200 all adsorbed uranium similarly well with Kd values ranging from ~15,000 to 95,000 ml/g. All four resins would be considered suitable for use in the treatment system based on uranium adsorption characteristics. • Lowering the pH of the high nitrate test conditions from 8.2 to 7.5 did not significantly change the uranium adsorption isotherms for the four tested resins. The Kd values for these four resins under high nitrate (1338 mg/L), lower pH (7.5) ranged from ~15,000 to 80,000 ml/g. • Higher nitrate concentrations greatly reduced the uranium adsorption on all four resins. Tests conducted with unspiked (no amendments; nitrate at 337 mg/L and pH at 8.2) source water yielded Kd values for Dowex 1, Dowex 21K 16-30 (fresh), Purofine PFA600/4740, and ResinTech SIR-1200 resins ranging from ~800,000 to >3,000,000 ml/g. These values are about two orders of magnitude higher than the Kd values noted from tests conducted using amended source water. • Compared to the fresh resin, the regenerated Dowex 21K 16-30 resin exhibited significantly lower uranium-adsorption performance under all test conditions. The calculated Kd values for the regenerated resin were typically an order of magnitude lower than the values calculated for the fresh resin. • Additional testing using laboratory columns is recommended to better

  7. Fouling of anion exchange resin by fluorescence analysis in advanced treatment of municipal wastewaters.

    PubMed

    Li, Haibo; Li, Aimin; Shuang, Chendong; Zhou, Qing; Li, Wentao

    2014-12-01

    The application of anion exchange resins (AERs) has been limited by the critical problem of resin fouling, which increases the volume of the desorption concentrate and decreases treatment efficiency. To date, resin fouling has not been well studied and is poorly understood compared to membrane fouling. To reflect the resin fouling level, a resin fouling index (RFI) was established in this work according to the decrease of DOC removal after regeneration of the resin for the advanced treatment of municipal wastewater. Comparing the linear fitting results between the RFI and the fluorescence intensity indicated that the resin fouling was related to the protein-like substances with fluorescence peak T in the region of excitation wavelength <250 nm and emission wavelength <380 nm. Using their fluorescent characteristics as a label, the protein-like substances causing the fouling were further identified as hydrophilic components with molecular weights greater than 6500 Da. PMID:25218660

  8. Radiation effects on amberlite IRA-938 and bio-rad AG MP-50 ion exchange resins. [Gamma radiation

    SciTech Connect

    Kazanjian, A.R.; Killion, M.E.

    1982-01-15

    The radiation stability of Amberlite IRA-938, an anion exchange resin, and Bio-Rad AG MP-50, a cation exchange resin, was investigated. The resins were gamma irradiated and analyzed for exchange capacity, gas generation, thermal stability, and plutonium capacity. The radiation stabilities were comparable to those of Dowex 11 and Dowex 50W-X8, the resins presently used in Rocky Flats recovery operations.

  9. Vitrification of Cesium-Laden Organic Ion Exchange Resin in a Stirred Melter

    SciTech Connect

    Cicero-Herman, C.A; Sargent, T.N.; Overcamp, T.J.; Bickford, D.F.

    1997-07-09

    The goal of this research was a feasibility study for vitrifying the organic ion exchange resin in a stirred-tank melter. Tests were conducted to determine the fate of cesium including the feed, exit glass, and offgas streams and to assess any impact of feeding the resin on the melter or its performance.

  10. Preparation of polymer-coated, scintillating ion-exchange resins for monitoring of 99Tc in groundwater.

    PubMed

    Seliman, Ayman F; Samadi, Azadeh; Husson, Scott M; Borai, Emad H; DeVol, Timothy A

    2011-06-15

    The present study was oriented to prepare new scintillating anion-exchange resins for measurement of (99)TcO(4)(-) in natural waters. The organic fluor 2-(1-naphthyl)-5-phenyloxazole was diffused into (chloromethyl)polystyrene resin. Thereafter, a thin layer of poly[[2-(methacryloyloxy)ethyl]trimethylammonium chloride] was grafted from the resin surface by surface-initiated atom transfer radical polymerization as an attempt to overcome potential problems related to the leaching of fluor molecules during usage. The residual chloromethyl groups of the polymer-coated resin were aminated by reaction with two different tertiary amines, triethylamine (TEA) and methyldioctylamine (MDOA). Off- and on-line quantification of (99)Tc was achieved with high detection efficiencies of 60.72 ± 1.93% and 72.83 ± 0.81% for resin with TEA and MDOA functional groups, respectively. The detection limit was determined to be less than the maximum contaminant level (33 Bq L(-1)) established under the Safe Drinking Water Act. The two functionalized resins were demonstrated to be selective for pertechnetate from synthetic groundwater containing up to 1000 ppm Cl(-), SO(4)(2-), and HCO(3)(-) and up to 1200 ppb Cr(2)O(7)(2-) in an acidic medium. PMID:21609030

  11. Adsorption of three pharmaceuticals on two magnetic ion-exchange resins.

    PubMed

    Jiang, Miao; Yang, Weiben; Zhang, Ziwei; Yang, Zhen; Wang, Yuping

    2015-05-01

    The presence of pharmaceuticals in aquatic environments poses potential risks to the ecology and human health. This study investigated the removal of three widely detected and abundant pharmaceuticals, namely, ibuprofen (IBU), diclofenac (DC), and sulfadiazine (SDZ), by two magnetic ion-exchange resins. The adsorption kinetics of the three adsorbates onto both resins was relatively fast and followed pseudo-second-order kinetics. Despite the different pore structures of the two resins, similar adsorption patterns of DC and SDZ were observed, implying the existence of an ion-exchange mechanism. IBU demonstrated a combination of interactions during the adsorption process. These interactions were dependent on the specific surface area and functional groups of the resin. The adsorption isotherm fittings verified the differences in the behavior of the three pharmaceuticals on the two magnetic ion-exchange resins. The presence of Cl- and SO4(2-) suppressed the adsorption amount, but with different inhibition levels for different adsorbates. This work facilitates the understanding of the adsorption behavior and mechanism of pharmaceuticals on magnetic ion-exchange resins. The results will expand the application of magnetic ion-exchange resins to the removal of pharmaceuticals in waters. PMID:25968278

  12. TREATMENT FOR IMPROVING THE OPERATION OF STRONG BASE ANION EXCHANGE RESINS

    DOEpatents

    Stevenson, P.C.

    1960-11-29

    A process is offered for improving quaternary ammonium type strongly basic anion exchange resins so that centain zinc and cadmium residues, which normally stick to and "poison" this type of resin, can be removed by elution. Specifically, the resin as obtained commercially is treated with an aqueous solution of sodium hydroxide of about 1 to 4 M concentration by heating therein and periodically adding small amounts of oxidizing agent selected from hydrogen peroxide, sodium peroxide and hypochlorite. Zinc and cadmium values may then be adsorbed onto the resin from a 0.1 to 3 M HCl and thereafter eluted therefrom with very dilute HCl solutions.

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

    SciTech Connect

    Bagosi, S.; Csetenyi, L.J.

    1999-04-01

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

  14. Evaluation of Selective Ion Exchange Resins for Removal of Mercury from the H-Area Water Treatment Unit

    SciTech Connect

    Serkiz, S.M.

    2000-09-05

    This study investigated the ability of seven ion exchange (IX) resins, some of which were mercury specific, to remove mercury in H-Area WTU waters from three sources (Reverse Osmosis (RO) Feed, RO Permeate from Train A, and a mercury ''hot spot'' extraction well HEX 18). Seven ion exchange resins, including ResinTech CG8 and Dowex 21K (the cation and anion exchange resins currently used at the H-Area WTU) were screened against five alternative ion exchange materials plus an experimental blank. Mercury decontamination factors (DFs), mercury breakthrough, and post-test contaminant concentrations of IX resins were determined for each IX material tested.

  15. Anion exchange resins: Structure, formulation, and applications. (Latest citations from the Rubber and Plastics Research Association database). Published Search

    SciTech Connect

    Not Available

    1994-07-01

    The bibliography contains citations concerning the formulation and synthesis of anion exchange resins based on such resins as amides, polyethylenes, and styrenes. Osmotic, sorption, and electrical properties; exchange kinetics behavior; structure studies; and temperature related performance effects on anion exchange resins are considered. Anion exchange chromatography of liquids, and applications in water purification, pollution control, and protein and metallic ion separation are included. (Contains a minimum of 222 citations and includes a subject term index and title list.)

  16. Cement waste-form development for ion-exchange resins at the Rocky Flats Plant

    SciTech Connect

    Veazey, G.W.; Ames, R.L.

    1997-03-01

    This report describes the development of a cement waste form to stabilize ion-exchange resins at Rocky Flats Environmental Technology Site (RFETS). These resins have an elevated potential for ignition due to inadequate wetness and contact with nitrates. The work focused on the preparation and performance evaluation of several Portland cement/resin formulations. The performance standards were chosen to address Waste Isolation Pilot Plant and Environmental Protection Agency Resource Conservation and Recovery Act requirements, compatibility with Rocky Flats equipment, and throughput efficiency. The work was performed with surrogate gel-type Dowex cation- and anion-exchange resins chosen to be representative of the resin inventory at RFETS. Work was initiated with nonactinide resins to establish formulation ranges that would meet performance standards. Results were then verified and refined with actinide-containing resins. The final recommended formulation that passed all performance standards was determined to be a cement/water/resin (C/W/R) wt % ratio of 63/27/10 at a pH of 9 to 12. The recommendations include the acceptable compositional ranges for each component of the C/W/R ratio. Also included in this report are a recommended procedure, an equipment list, and observations/suggestions for implementation at RFETS. In addition, information is included that explains why denitration of the resin is unnecessary for stabilizing its ignitability potential.

  17. An evaluation of organic substance fraction removal during ion exchange with Miex-DOC resin.

    PubMed

    Wolska, Małgorzata

    2015-07-01

    In this study, the usefulness of Miex-DOC resin in eliminating organic substances and their fractions from water sources for drinking water was evaluated. The objects of study were samples from three surface water sources and one infiltration water source taken at water treatment plants before treatment in technical conditions. In particular, the effectiveness of removing biodegradable and non-biodegradable fractions as a function of resin dosages and water-resin contact times was evaluated. The ion exchange process with the Miex-DOC resin achieved a high effectiveness in removing aromatic non-biodegradable organic substances, and therefore a reduction in UV254 absorbance. The biodegradable fraction is much less susceptible to removal yet its removal effectiveness allows for a significant reduction in hazards connected with secondary microorganism development. The results of this study indicate the possibility of using ion exchange with the Miex-DOC resin for effective removal of disinfection by-product precursors. PMID:25976333

  18. RESORCINOL-FORMALDEHYDE ION EXCHANGE RESIN CHEMISTRY FOR HIGH LEVEL WASTE TREATMENT

    SciTech Connect

    Nash, C.; Duignan, M.

    2010-01-14

    A principal goal at the Savannah River Site is to safely dispose of the large volume of liquid nuclear waste held in many storage tanks. In-tank ion exchange technology is being considered for cesium removal using a polymer resin made of resorcinol formaldehyde that has been engineered into microspheres. The waste under study is generally lower in potassium and organic components than Hanford waste; therefore, the resin performance was evaluated with actual dissolved salt waste. The ion exchange performance and resin chemistry results are discussed.

  19. Russian studies of the safety of anion exchange in nitric acid

    SciTech Connect

    Hyder, M.L.; Bartenev, S.A.; Lazarev, L.N.

    1997-07-01

    Synthetic ion exchange resins came into use in the Soviet Union in the 1950`s, and domestic anion exchange resins based on quaternary amine groups have long been used in the Russian nuclear industry. These resins are similar to resins used in the West, and include pyridine-based resins, as well as the more conventional aryl polymers with substituted methyl amines. (Slide 1) The sensitivity of these amines to reaction with nitric acid and other oxidants has been a concern in Russia as in the West, and numerous laboratory studies have been conducted on the reactions involved. Several incidents involving pressure or temperature excursions have provided incentives for such studies. (Slide 2) This report briefly summarizes this work. A report by the Russian authors of this paper providing greater detail is to be issued as a U.S. Dept. of Energy document. Additionally, a second report by these authors, describing new studies on anion exchange resin safety, will also be issued as a DOE report. The separation of plutonium, neptunium, etc. from other materials by ion exchange requires rather strong nitric acid (6-8 M). In some systems, such as the processing of {sup 238}Pu, intense ionizing radiation may also be present during ion exchange separation. As a result, it is necessary to consider not only thermal hydrolysis and oxidation and their effects on the resin, but also radiolysis. All of these were investigated in the Russian studies.

  20. A simple method for classification of antibiotics using ion exchange resins added to agar plates.

    PubMed

    Yoshida, K; Kondo, F

    1994-01-01

    Using two different ion-exchange resins (Dowex 50W-X4 as cation and Dowex 1-X4 as anion) added directly to assay plates seeded with Bacillus subtilis or Micrococcus luteus, the size of the inhibitory zone produced by 36 antimicrobial agents around a disc or cup was characterized into various types, such as acidic, basic or amphoteric. An increase of the inhibition zone following addition of 15% Dowex 50W-X4 was evident in penicillins except for ampicillin and penicillin-G, and polyethers. Aminoglycosides, macrolides and colistin, lincomycin, and sulphonamides on assay medium treated with Dowex 1-X4 showed a similar effect on the inhibition zone. Tetracyclines, virginiamycin, oxolinic acid and furazoridone revealed no effects on the inhibition zone with either of the resins. These antibiotics could be divided into various groups on the basis of their chemical structure. This simple and rapid method may be useful for routine laboratory testing of residual antibiotics in meat. PMID:8152391

  1. Storage and Aging Effects on Spherical Resorcinol-Formaldehyde Resin Ion Exchange Performance

    SciTech Connect

    Fiskum, Sandra K.; Arm, Stuart T.; Edwards, Matthew K.; Steele, Marilyn J.; Thomas, Kathie K.

    2007-09-10

    Bechtel National, Inc. (BNI) is evaluating the alternate Cs ion exchanger, spherical resorcinol-formaldehyde (RF), for use in the River Protection Project-Waste Treatment Plant (RPP-WTP).( ) Previous test activities with spherical RF indicate that it has adequate capacity, selectivity, and kinetics to perform in the plant according to the flowsheet needs. It appears to have better elution and hydraulic properties than the existing alternatives: ground-gel RF and SuperLig® 644 (SL 644).( ) To date, the spherical RF performance testing has been conducted on freshly manufactured resin (within ~2 months of manufacture). The ion exchange resins will be manufactured and shipped to the WTP up to 1 year before being used in the plant. Changes in the resin properties during storage could reduce the capacity of the resin to remove Cs from low-activity waste solutions. Active sites on organic SL-644 resin have been shown to degrade during storage (Arm et al. 2004). Additional testing was needed to study the effects of storage conditions and aging on spherical RF ion exchange performance. Variables that could have a significant impact on ion exchange resins during storage include storage temperature, medium, and time. Battelle—Pacific Northwest Division (PNWD) was contracted to test the effects of various storage conditions on spherical RF resin. Data obtained from the testing will be used by the WTP operations to provide direction for suitable storage conditions and manage the spherical RF resin stock. Storage test conditions included wet and dry resin configurations under nitrogen at three temperatures. Work was initially conducted under contract number 24590-101-TSA-W000-00004 satisfying the needs defined in Appendix C of the Research and Technology Plan( ) TSS A-219 to evaluate the impact of storage conditions on RF resin performance. In February 2007, the contract mechanism was switched to Pacific Northwest National Laboratory (PNNL) Operating Contract DE-AC05-76RL

  2. Reactivity of Resorcinol Formaldehyde Resin with Nitric Acid

    SciTech Connect

    King, William D.; Fondeur, Fernando F.; Wilmarth, William R.; Pettis, Myra E.

    2005-10-25

    Solid-state infrared spectroscopy, differential scanning calorimetry, and elemental analysis have been used to evaluate the reactivity of resorcinol formaldehyde resin with nitric acid and characterize the solid product. Two distinct reactions were identified within the temperature range 25-55 C. The first reaction is primarily associated with resin nitration, while the second involves bulk oxidation and degradation of the polymer network leading to dissolution and off-gassing. The threshold conditions promoting reaction have been identified. Reaction was confirmed with nitric acid concentrations as low as 3 M at 25 C applied temperature and 0.625 M at 66 C. Although a nitrated resin product can be isolated under appropriate experimental conditions, calorimetry testing indicates no significant hazard associated with handling the dry material.

  3. REACTIVITY OF RESORCINOL FORMALDEHYDE RESIN WITH NITRIC ACID

    SciTech Connect

    King, W; Fernando Fondeur, F; Bill Wilmarth, B; Myra Pettis, M; Shirley Mccollum, S

    2006-06-14

    Solid-state infrared spectroscopy, differential scanning calorimetry, and elemental analysis have been used to evaluate the reactivity of resorcinol formaldehyde resin with nitric acid and characterize the solid product. Two distinct reactions were identified within the temperature range 25-55 C. The first reaction is primarily associated with resin nitration, while the second involves bulk oxidation and degradation of the polymer network leading to dissolution and off-gassing. Reaction was confirmed with nitric acid concentrations as low as 3 M at 25 C applied temperature and 0.625 M at 66 C. Although a nitrated resin product can be isolated under appropriate experimental conditions, calorimetry testing indicates no significant hazard associated with handling the dry material.

  4. Purification of organic acids by chromatography with strong anionic resins: Investigation of uptake mechanisms.

    PubMed

    Lemaire, Julien; Blanc, Claire-Line; Lutin, Florence; Théoleyre, Marc-André; Stambouli, Moncef; Pareau, Dominique

    2016-08-01

    Bio-based organic acids are promising renewable carbon sources for the chemical industry. However energy-consuming purification processes are used, like distillation or crystallization, to reach high purities required in some applications. That is why preparative chromatography was studied as an alternative separation technique. In a previous work dealing with the purification of lactic, succinic and citric acids, the Langmuir model was insufficient to explain the elution profiles obtained with a strong anionic resin. Consequently the Langmuir model was coupled with a usual ion-exchange model to take into account the retention of their conjugate bases (<2%), which are commonly neglected at low pH (<1.5). Elution simulations with both uptake mechanisms fitted very well with experimental pulse tests. Only two parameters were optimized (equilibrium constant of acid uptake and ion-exchange selectivity coefficient of conjugate base) and their value were coherent with experimental and resin suppliers' data. These results confirmed that the singular tailing and apparent delay observed with succinic and citric acids can be explained by the high affinity of succinate and citrate for resin cationic sites. The model was implemented in a preparative chromatography simulation program in order to optimize operating parameters of our pilot-scale ISMB unit (Improved Simulated Moving Bed). The comparison with experimental ISMB profiles was conclusive. PMID:27373374

  5. Taste Masked Orodispersible Formulation of Fexofenadine Hydrochloride Using Ion Exchange Resins.

    PubMed

    Suares, Divya; Hiray, Arti

    2015-01-01

    The objective of this research work was to mask the intense bitter taste of fexofenadine hydrochloride using weak cation exchange resins and to formulate orodispersible tablet of taste masked drug-resin complex. Five resins indion 204, indion 234, indion 414, kyron T-114 and kyron T-314 were used. Depending on maximum drug loading capacity of resins indion 234 and kyron T-314 were finalized for further study. Drug-resin complex was optimized by considering parameters such as drug to resin ratio, soaking time of resins, stirring time, temperature and pH on maximum drug loading. The drug-resin complex was characterized by Fourier transform infrared spectroscopy. The drug-resin complex was also subjected to various evaluation studies such as taste mask evaluation by panel method, drug content and in vitro drug release at salivary and gastric pH. The orodispersible tablets of taste masked drug-resin complex for indion 234 and kyron T-314 were prepared by direct compression method. Formulated orodispersible tablets were subjected to various evaluation parameters such as diameter and thickness measurement, hardness test, weight variation test, in vitro United States Pharmacopoeia disintegration test, wetting time, test for content uniformity, assay, friability test and in vitro dissolution studies. The results indicate that orodispersible tablets of fexofenadine hydrochloride containing indion 234 and kyron T-314 are palatable and provide quick disintegration and fast drug release without addition of superdisintegrants. PMID:26798169

  6. Taste Masked Orodispersible Formulation of Fexofenadine Hydrochloride Using Ion Exchange Resins

    PubMed Central

    Suares, Divya; Hiray, Arti

    2015-01-01

    The objective of this research work was to mask the intense bitter taste of fexofenadine hydrochloride using weak cation exchange resins and to formulate orodispersible tablet of taste masked drug-resin complex. Five resins indion 204, indion 234, indion 414, kyron T-114 and kyron T-314 were used. Depending on maximum drug loading capacity of resins indion 234 and kyron T-314 were finalized for further study. Drug-resin complex was optimized by considering parameters such as drug to resin ratio, soaking time of resins, stirring time, temperature and pH on maximum drug loading. The drug-resin complex was characterized by Fourier transform infrared spectroscopy. The drug-resin complex was also subjected to various evaluation studies such as taste mask evaluation by panel method, drug content and in vitro drug release at salivary and gastric pH. The orodispersible tablets of taste masked drug-resin complex for indion 234 and kyron T-314 were prepared by direct compression method. Formulated orodispersible tablets were subjected to various evaluation parameters such as diameter and thickness measurement, hardness test, weight variation test, in vitro United States Pharmacopoeia disintegration test, wetting time, test for content uniformity, assay, friability test and in vitro dissolution studies. The results indicate that orodispersible tablets of fexofenadine hydrochloride containing indion 234 and kyron T-314 are palatable and provide quick disintegration and fast drug release without addition of superdisintegrants. PMID:26798169

  7. PILOT-SCALE HYDRAULIC TESTING OF RESORCINOL FORMALDEHYDE ION EXCHANGE RESIN

    SciTech Connect

    Adamson, D

    2006-11-08

    Savannah River National Laboratory (SRNL) performed pilot-scale hydraulic/chemical testing of spherical resorcinol formaldehyde (RF) ion exchange (IX) resin for the River Protection Project-Hanford Tank Waste Treatment & Immobilization Plant (WTP) Project. The RF resin cycle testing was conducted in two pilot-scale IX columns, 1/4 and 1/2 scale. A total of twenty-three hydraulic/chemical cycles were successfully completed on the spherical RF resin. Seven of the cycles were completed in the 12 inch IX Column and sixteen cycles were completed in the 24 inch IX Column. Hydraulic testing showed that the permeability of the RF resin remained essentially constant, with no observed trend in the reduction of the permeability as the number of cycles increased. The permeability during the pilot-scale testing was 2 1/2 times better than the design requirements of the WTP full-scale system. The permeability of the resin bed was uniform with respect to changes in bed depth. Upflow Regeneration and Simulant Introduction in the IX columns revealed another RF resin benefit; negligible radial pressures to the column walls from the swelling of resin beads. In downflow of the Regeneration and Simulant Introduction steps, the resin bed particles pack tightly together and produce higher hydraulic pressures than that found in upflow. Also, upflow Simulant Introduction produced an ideal level bed for the twenty cycles completed using upflow Simulant Introduction. Conversely, the three cycles conducted using downflow Simulant Introduction produced an uneven bed surface with erosion around the thermowells. The RF resin bed in both columns showed no tendency to form fissures or pack more densely as the number of cycles increased. Particle size measurements of the RF resin showed no indication of particle size change (for a given chemical) with cycles and essentially no fines formation. Micrographs comparing representative bead samples before and after testing indicated no change in bead

  8. PILOT-SCALE HYDRAULIC TESTING OF RESORCINOL FORMALDEHYDE ION EXCHANGE RESIN

    SciTech Connect

    Adamson, D

    2007-01-09

    Savannah River National Laboratory (SRNL) performed pilot-scale hydraulic/chemical testing of spherical resorcinol formaldehyde (RF) ion exchange (IX) resin for the River Protection Project Hanford Tank Waste Treatment & Immobilization Plant (WTP) Project. The RF resin cycle testing was conducted in two pilot-scale IX columns, 1/4 and 1/2 scale. A total of twenty-three hydraulic/chemical cycles were successfully completed on the spherical RF resin. Seven of the cycles were completed in the 12-inch IX Column and sixteen cycles were completed in the 24-inch IX Column. Hydraulic testing showed that the permeability of the RF resin remained essentially constant, with no observed trend in the reduction of the permeability as the number of cycles increased. The permeability during the pilot-scale testing was 2 1/2 times better than the design requirements of the WTP full-scale system. The permeability of the resin bed was uniform with respect to changes in bed depth. Upflow Regeneration and Simulant Introduction in the IX columns revealed another RF resin benefit; negligible radial pressures to the column walls from the swelling of resin beads. In downflow of the Regeneration and Simulant Introduction steps, the resin bed particles pack tightly together and produce higher hydraulic pressures than that found in upflow. Also, upflow Simulant Introduction produced an ideal level bed for the twenty cycles completed using upflow Simulant Introduction. Conversely, the three cycles conducted using downflow Simulant Introduction produced an uneven bed surface with erosion around the thermowells. The RF resin bed in both columns showed no tendency to form fissures or pack more densely as the number of cycles increased. Particle size measurements of the RF resin showed no indication of particle size change (for a given chemical) with cycles and essentially no fines formation. Micrographs comparing representative bead samples before and after testing indicated no change in bead

  9. EVALUATION OF POTENTIAL ELUANTS FOR NON-ACID ELUTION OF CESIUM FROM RESORCINOL-FORMALDEHYDE RESIN

    SciTech Connect

    Adu-Wusu, K.; Pennebaker, F.

    2010-12-22

    Small-column ion exchange (SCIX) units installed in high-level waste tanks to remove Cs-137 from highly alkaline salt solutions are among the waste treatment plans in the DOE-complex. Spherical Resorcinol-Formaldehyde (sRF) is the ion exchange resin selected for use in the Hanford Waste Treatment and Immobilization Plant (WTP). It is also the primary ion exchange material under consideration for SCIX at the Hanford site. The elution step of the multi-step ion exchange process is typically done with 0.5 M nitric acid. An acid eluant is a potential hazard in the event of a spill, leak, etc. because the high-level waste tanks are made of carbon steel. Corrosion and associated structural damage may ensue. A study has been conducted to explore non-acid elution as an alternative. Batch contact sorption equilibrium screening tests have been conducted with 36 potential non-acid eluants. The sorption tests involve equilibrating each cesium-containing eluant solution with the sRF resin for 48 hours at 25 C in a shaker oven. In the sorption tests, an eluant is deemed to have a high cesium elution potential if it minimizes cesium sorption onto the sRF resin. The top candidates (based on lowest cesium sorption distribution coefficients) include ammonium carbonate, ammonium carbonate/ammonium hydroxide, ammonium bicarbonate, rubidium carbonate, ammonium acetate, ammonium acetate/ammonium hydroxide, ammonium bicarbonate/ammonium hydroxide, calcium chloride, and magnesium chloride. A select few of the top candidate eluants from the screening tests were subjected to actual sorption (loading) and elution tests to confirm their elution ability. The actual sorption (loading) and elution tests mimicked the typical sRF-cesium ion exchange process (i.e., sorption or loading, caustic wash, water rinse, and elution) via batch contact sorption and quasi column caustic wash/water rinse/elution. The eluants tested included ammonium carbonate, ammonium acetate, calcium acetate, magnesium

  10. 21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Partial phosphoric acid esters of polyester resins... of polyester resins. Partial phosphoric acid esters of polyester resins identified in this section... prescribed conditions: (a) For the purpose of this section, partial phosphoric acid esters of...

  11. Anion-exchange resin-based desulfurization process. Quarterly technical progress report, October 1, 1992--December 31, 1992

    SciTech Connect

    Sheth, A.C.; Dharmapurikar, R.

    1992-12-31

    Under DOE Grant No. DE-FG22-90PC90309, the University of Tennessee Space Institute (UTSI) is contracted to further develop its anion-exchange, resin-based desulfurization concept to desulfurize alkali metal sulfates. From environmental as well as economic viewpoints, it is necessary to remove soluble sulfates from the wastes created by flue gas desulfurization systems. In order to do this economically, a low-cost desulfurization process for spent sorbents is necessary. UTSI`s anion-exchange resin-based desulfurization concept is believed to satisfy these requirements. During the reporting period, October 1, 1992--December 31, 1992, UTSI has completed the batch mode experiments to evaluate the performance enhancement effect caused by organic acids on the resin`s exhaustion efficiency. At present, batch mode experiments are being conducted to locate the position of the CO{sub 3}= and SO{sub 4}= ions in the affinity chart, and also reviewing/assessing the ASPEN Code`s capabilities for use in the development of the Best Process Schematic and related economics.

  12. Effect of humic acid on ciprofloxacin removal by magnetic multifunctional resins

    PubMed Central

    Wang, Wei; Cheng, Jiade; Jin, Jing; Zhou, Qing; Ma, Yan; Zhao, Qingqing; Li, Aimin

    2016-01-01

    Background organic matter significantly influences the removal of emerging contaminants in natural water. In this work, the adsorption of ciprofloxacin (CPX) onto a series of magnetic multifunctional resins (GMA10-GMA90) in the presence and absence of humic acid (HA) was conducted to demonstrate the effect of HA. Both hydrophobic and ion exchange interactions contributed to CPX adsorption. Negative charge-assisted hydrogen bonds also participated in the adsorption process, resulting in the high adsorption amount of anionic CPX onto the negatively charged GMA30 under basic solutions. HA could impact CPX adsorption not only as a competitive adsorbate but also as an additional adsorbent. At pH 5.6, the additional adsorption sites provided by adsorbed HA molecules on the resins dominated and thus facilitated the adsorption process. While at pH 10, HA inhibited the adsorption of CPX by directly competing for ion exchange sites and coexisting with CPX in the solution. The ratio of the amount of CPX adsorbed by dissolved HA to that by the resin reached as high as 1.61 for GMA90. The adsorbed HA molecules onto the resins could provide additional adsorption sites for CPX as proven by the enhanced CPX adsorption in HA-preloading systems at pH 5.6. PMID:27464502

  13. Effect of humic acid on ciprofloxacin removal by magnetic multifunctional resins.

    PubMed

    Wang, Wei; Cheng, Jiade; Jin, Jing; Zhou, Qing; Ma, Yan; Zhao, Qingqing; Li, Aimin

    2016-01-01

    Background organic matter significantly influences the removal of emerging contaminants in natural water. In this work, the adsorption of ciprofloxacin (CPX) onto a series of magnetic multifunctional resins (GMA10-GMA90) in the presence and absence of humic acid (HA) was conducted to demonstrate the effect of HA. Both hydrophobic and ion exchange interactions contributed to CPX adsorption. Negative charge-assisted hydrogen bonds also participated in the adsorption process, resulting in the high adsorption amount of anionic CPX onto the negatively charged GMA30 under basic solutions. HA could impact CPX adsorption not only as a competitive adsorbate but also as an additional adsorbent. At pH 5.6, the additional adsorption sites provided by adsorbed HA molecules on the resins dominated and thus facilitated the adsorption process. While at pH 10, HA inhibited the adsorption of CPX by directly competing for ion exchange sites and coexisting with CPX in the solution. The ratio of the amount of CPX adsorbed by dissolved HA to that by the resin reached as high as 1.61 for GMA90. The adsorbed HA molecules onto the resins could provide additional adsorption sites for CPX as proven by the enhanced CPX adsorption in HA-preloading systems at pH 5.6. PMID:27464502

  14. Effect of humic acid on ciprofloxacin removal by magnetic multifunctional resins

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Cheng, Jiade; Jin, Jing; Zhou, Qing; Ma, Yan; Zhao, Qingqing; Li, Aimin

    2016-07-01

    Background organic matter significantly influences the removal of emerging contaminants in natural water. In this work, the adsorption of ciprofloxacin (CPX) onto a series of magnetic multifunctional resins (GMA10-GMA90) in the presence and absence of humic acid (HA) was conducted to demonstrate the effect of HA. Both hydrophobic and ion exchange interactions contributed to CPX adsorption. Negative charge-assisted hydrogen bonds also participated in the adsorption process, resulting in the high adsorption amount of anionic CPX onto the negatively charged GMA30 under basic solutions. HA could impact CPX adsorption not only as a competitive adsorbate but also as an additional adsorbent. At pH 5.6, the additional adsorption sites provided by adsorbed HA molecules on the resins dominated and thus facilitated the adsorption process. While at pH 10, HA inhibited the adsorption of CPX by directly competing for ion exchange sites and coexisting with CPX in the solution. The ratio of the amount of CPX adsorbed by dissolved HA to that by the resin reached as high as 1.61 for GMA90. The adsorbed HA molecules onto the resins could provide additional adsorption sites for CPX as proven by the enhanced CPX adsorption in HA-preloading systems at pH 5.6.

  15. Potential mechanisms for bioregeneration of perchlorate-containing ion-exchange resin.

    PubMed

    Sharbatmaleki, Mohamadali; Unz, Richard F; Batista, Jacimaria R

    2015-05-15

    Ion-exchange (IX) is the most feasible technology for perchlorate removal from drinking water. Reuse of resins present challenges, however. Selective resins are non-regenerable, and are incinerated after one time use, while non-selective resins, when regenerable, produce a waste stream that contains high concentration of perchlorate that must be disposed of. A process to bioregenerate spent resin containing perchlorate with perchlorate-reducing bacteria (PRB) has been recently developed. In this research, potential mechanisms for bioregeneration of resin-attached perchlorate (RAP) were investigated. Batch bioregeneration experiments were performed using gel-type and macroporous-type resins. Various initial chloride concentrations and various resin bead sizes were used. The results of the bioregeneration experiments suggested that chloride, i.e. the product of perchlorate biodegradation, is more likely the desorbing agent of RAP; and increasing the concentration of chloride enhances the bioregeneration process. Both film and pore diffusion were found to be relevant with respect to the rate of perchlorate mass-transfer to the bulk liquid. Bioregeneration was found to be more effective for macroporous than for gel-type resins, especially in the case of macroporous resins with relatively small bead size in the presence of higher chloride concentration. PMID:25746957

  16. PILOT-SCALE HYDRAULIC TESTING OF RESORCINOL FORMALDEHYDE ION EXCHANGE RESIN

    SciTech Connect

    Adamson, D.

    2009-05-28

    Savannah River National Laboratory (SRNL) performed pilot-scale hydraulic/chemical testing of spherical resorcinol formaldehyde (RF) ion exchange (IX) resin for the River Protection Project-Hanford Tank Waste Treatment & Immobilization Plant (WTP) Project. The RF resin hydraulic cycle testing was conducted in two pilot-scale IX columns, 1/4 and 1/2 scale. A total of twenty-three hydraulic/chemical cycles were successfully completed on the spherical RF resin. Sixteen of these cycles were completed in the 24-inch IX Column (1/2 scale column). Hydraulic testing showed that the permeability of the RF resin remained essentially constant, with no observed trend in the reduction of the permeability as the number of cycles increased. The permeability during the pilot-scale testing was 3 times better than the design requirements of the WTP full-scale IX system. The RF resin bed showed no tendency to form fissures or pack more densely as the number of cycles increased. Particle size measurements of the RF resin showed no indication of particle size change (for a given chemical) with cycles and essentially no fines formation. The permeability of the resin bed was uniform with respect to changes in bed depth. Upflow Regeneration and Simulant Introduction in the IX columns revealed another RF resin benefit; negligible radial pressures to the column walls from the swelling of resin beads. The hydraulic and chemical performance of the spherical RF resin during cycle testing was found to be superior to all other tested IX resins. The pilot-scale testing indicates that the RF resin is durable and should hold up to many hydraulic cycles in actual radioactive Cesium (Cs) separation.

  17. The characteristic assessment of spent ion exchange resin from PUSPATI TRIGA REACTOR (RTP) for immobilization process

    SciTech Connect

    Wahida, Nurul; Yasir, Muhamad Samudi; Majid, Amran Ab; Irwan, M. N.; Wahab, Mohd Abd; Marzukee, Nik; Paulus, Wilfred; Phillip, Esther; Thanaletchumy

    2014-09-03

    In this paper, spent ion exchange resin generated from PUSPATI TRIGA reactor (RTP) in Malaysian Nuclear Agency were characterized based on the water content, radionuclide content and radionuclide leachability. The result revealed that the water content in the spent resin is 48%. Gamma spectrometry analysis indicated the presence of {sup 134}Cs, {sup 137}Cs, {sup 152}Eu, {sup 54}Mn, {sup 58}Co, {sup 60}Co and {sup 65}Zn. The leachability test shows a small concentrations (<1 Bq/l) of {sup 152}Eu and {sup 134}Cs were leached out from the spent resin while {sup 60}Co activity concentrations slightly exceeded the limit generally used for industrial wastewater i.e. 1 Bq/l. Characterization of spent ion exchange resin sampled from RTP show that this characterization is important as a basis to immobilize this radioactive waste using geopolymer technology.

  18. The characteristic assessment of spent ion exchange resin from PUSPATI TRIGA REACTOR (RTP) for immobilization process

    NASA Astrophysics Data System (ADS)

    Wahida, Nurul; Yasir, Muhamad Samudi; Majid, Amran Ab; Wahab, Mohd Abd; Marzukee, Nik; Paulus, Wilfred; Phillip, Esther; Thanaletchumy, Irwan, M. N.

    2014-09-01

    In this paper, spent ion exchange resin generated from PUSPATI TRIGA reactor (RTP) in Malaysian Nuclear Agency were characterized based on the water content, radionuclide content and radionuclide leachability. The result revealed that the water content in the spent resin is 48%. Gamma spectrometry analysis indicated the presence of 134Cs, 137Cs, 152Eu, 54Mn, 58Co, 60Co and 65Zn. The leachability test shows a small concentrations (<1 Bq/l) of 152Eu and 134Cs were leached out from the spent resin while 60Co activity concentrations slightly exceeded the limit generally used for industrial wastewater i.e. 1 Bq/l. Characterization of spent ion exchange resin sampled from RTP show that this characterization is important as a basis to immobilize this radioactive waste using geopolymer technology.

  19. Processing of Spent Ion Exchange Resins in a Rotary Calciner - 12212

    SciTech Connect

    Kascheev, Vladimir; Musatov, Nikolay

    2012-07-01

    Processing Russian nuclear ion exchange resin KU-2 using a 'Rotary' calciner was conducted. The resulting product is a dry free flowing powder (moisture content 3 wt.%, Angle of repose of ≅ 20 deg.). Compared with the original exchange resin the volume of the final product is about 3 times less.. Rotary calciner product can be stored in metal drums or in special reinforced concrete cubicles. After thermal treatment in a rotary calciner, the spent resin product can be solidified in cement yielding the following attributes: - The cemented waste is only a 35% increase over the volume of powder product; - The volume of cement calciner product is almost 9 times less (8.7) than the volume of cement solidified resin; - The mechanical strength of cemented calciner product meets the radioactive waste regulations in Russia. (authors)

  20. High-Capacity and Rapid Removal of Refractory NOM Using Nanoscale Anion Exchange Resin.

    PubMed

    Johnson, Billy R; Eldred, Tim B; Nguyen, Andy T; Payne, William M; Schmidt, Emily E; Alansari, Amir Y; Amburgey, James E; Poler, Jordan C

    2016-07-20

    As human health concerns over disinfection byproducts (DBP) in drinking water increase, so does the need to develop new materials that remove them rapidly and at high capacity. Ion exchange (IEX) is an effective method for the removal of natural organic matter (NOM), especially anion exchange resins (AERs) with quaternary ammonium functional groups. However, capacity is limited in existing commercial resin materials because adsorbates can only interact with the outermost surface area, which makes these products inefficient on a mass basis. We have synthesized a novel "NanoResin" exploiting the enhanced NOM removal of the quaternary ammonium resin while utilizing the vast surface area of SWCNTs, which act as scaffolding for the resin. Our nanomaterials show increased adsorption capacity compared to commercially available adsorbents, in a fraction of the time. This NanoResin requires only about 10 s to reach ion-exchange equilibrium. Comparatively, commercial AERs only achieved partial removal after more than 30 min. High capacity adsorption of a low molecular weight (MW) surrogate has been measured. NOM removal was demonstrated in solutions of both low and high specific UV absorbance (SUVA) composition with these nanomaterials. Additionally, the NanoResin showed enhanced removal of a NOM concentrate sample taken from Myrtle Beach, SC, demonstrating NanoResin is an effective method of removal for refractory NOM in a natural aqueous environment. Synthesis and characterization of the polymers and nanomaterials are presented below. Adsorption capacity, adsorption kinetics, and the regeneration and reusability of these new materials for NOM removal are described. The open matrix microstructure precludes any intraparticle diffusion of adsorbates; thus, these nanomaterials act as a "contact resin". PMID:27348616

  1. DEVELOPMENT OF AN APPROACH TO MODELING LOADING AND ELUTION OF SPHERICAL RESORCINOL FORMALDEHYDE ION-EXCHANGE RESIN

    SciTech Connect

    Aleman, S.; Hamm, L.; Smith, F.

    2011-10-03

    fixed ionogenic groups that make up sRF. Recent literature reviews and scoping titration tests strongly indicate that sRF is a polyfunctional cation exchange resin with at least three dominant types of ring groups playing a role in its isotherm behavior over the wide pH range of operations. Also three types of fixed ionogenic acid groups are present: sulfonic (SO{sub 3}H{sup -}) groups; carboxylic (COOH{sup -}) groups, and resorcylic (OH{sup -}) groups. It is this premise that we are working under in the development of a robust isotherm model for sRF over its entire planned pH operating range. The application of prototypic isotherms for modeling ion-exchange column behavior is demonstrated in Section 3 of this report. This preliminary work served to focus the development effort on the use of a mass-action based isotherm. In Section 4 of this report, the foundational material required to develop a robust isotherm model for sRF is provided. The paths taken, and choices made, are given for the reader to better understand our current status with respect to this goal and to highlight our most recent understanding of sRF exchange equilibria. Our ultimate goal is to update the CERMOD code (Aleman and Hamm, 2007) with a robust isotherm model for sRF that spans the entire pH and concentration ranges of planned operations. The isotherm model will then be used in the VERSE-LC code to model an entire ion-exchange cycle.

  2. Repeated use of ion-exchange resin membranes in calcareous soils

    USGS Publications Warehouse

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

    2003-01-01

    This study compared the consistency of nutrient extraction among repeated cycles of ion-exchange resin membrane use. Two sandy calcareous soils and different equilibration temperatures were tested. No single nutrient retained consistent values from cycle to cycle in all treatments, although both soil source and temperature conferred some influence. It was concluded that the most conservative use of resin membranes is single-use.

  3. Hydraulic Testing of Ion Exchange Resins for Cesium Removal from Hanford Tank Waste

    SciTech Connect

    Brooks, Kriston P.; Augspurger, Brian S.; Blanchard, David L.; Cuta, Judith M.; Fiskum, Sandra K.; Thorson, Murray R.

    2006-08-28

    Forty years of cold war nuclear weapons production activities have resulted in the by-product of millions of gallons of highly radioactive liquid and solid wastes stored in underground tanks at the Hanford Site in southeastern Washington State. The Department of Energy has contracted the construction of a waste-treatment processing plant to remove the major portions of radioactive isotopes from the liquid waste portion for follow-on processing and vitrification of the high-activity waste separately from the low-activity waste. The plant will use ion exchange processing for 137Cs removal from the supernatant portion of Hanford tank wastes. Currently, SuperLig? 644 (IBC Advanced Technologies, Utah) is the ion exchange resin of choice. However, during pilot-scale testing, significant pressure build-up occurred after multiple load-elute cycles. Current testing activities are evaluating resorcinol-formaldehyde (RF) resin as an alternative to achieve comparable loading and elution performance with improved hydraulic performance. Studies have been conducted with both a ground gel RF resin (Boulder Scientific, Colorado) and a spherical RF resin developed by Microbeads (Trondheim, Norway). The purpose of this testing was then to compare the vertical and radial forces of the expanding resin, the breakage of the resin beads, and the differential pressure across the resin bed during multiple load-elute cycles. These tests were done in a small-scale column with high flow rates to simulate the hydraulic conditions that would be experienced in a full-scale column.

  4. Separation of the rare earths by anion-exchange in the presence of lactic acid

    NASA Technical Reports Server (NTRS)

    Faris, J. P.

    1969-01-01

    Investigation of adsorption of rare earths and a few other elements to an anion-exchange resin from mixed solvents containing lactic acid shows that the lanthanides are absorbed more strongly than from the alpha-hydroxyisobutryric acid system, but with less separation between adjacent members of the series.

  5. Polymer resins with amino acid containing pendants for sorption of bilirubin. II. Polyamide resins with various basic amino acids.

    PubMed

    Henning, D S; Brown, G R; St-Pierre, L E

    1986-01-01

    Short peptides, three to eight amino acids in length, containing various combinations of alanine, arginine, lysine, histidine and tyrosine have been synthesized onto water-swellable polyamide resin by the solid phase peptide synthesis method. The amount of bilirubin adsorbed from aqueous buffer solution (pH = 7.8) by the resins increases with increasing basicity of the amino acids in the pendant. As the number of basic amino acids on the pendant is increased from one to five a 4.7 fold enhancement in the adsorption capacity is seen for arginine while a 9.3 fold enhancement is obtained for lysine. A corresponding increase in length for the non-basic histidine results in a 6 fold enhancement. With alanine the adsorption capacity is uneffected by an increase in pendant length. PMID:3957453

  6. Fatty and resinic acids extractions from crude tall oil

    SciTech Connect

    Nogueira, J.M.F.

    1996-11-01

    The separation of fatty and resinic acidic fractions from crude tall-oil soap solutions with n-heptane by the technique of dissociation extraction is discussed. The theory of the overall process is supported by a systematic study developed to cover the high selectivity demonstrated in the differential solubility and the aptness between fatty and diterpenic acids to both liquids phases. To study the main factors affecting those liquid-liquid extraction systems and the amphiphilic behavior of such molecules involved, sodium salts aqueous solutions of crude tall oil and synthetic mixtures as molecular acidic models were used.

  7. New Anion-Exchange Resins for Improved Separations of Nuclear Material

    SciTech Connect

    Barr, Mary E.; Bartsch, Richard A.; Jarvinen, Gordon D.

    2000-06-01

    We are developing bifunctional anion-exchange resins that facilitate anion uptake by carefully controlling the structure of the anion receptor site. Our new ion-exchange resins interface the rapidly developing field of ion-specific chelating ligands with robust, commercial ion-exchange technology. The basic scientific issues addressed are actinide complex speciation along with modeling of the metal complex/functional site interactions in order to determine optimal binding site characteristics. Resin materials that actively facilitate the uptake of actinide complexes from solution should display both improved selectivity and kinetic properties. Our implementation of the 'bifunctionality concept' involves N-derivatization of pyridinium units from a base poly(4- vinylpyridine) resin (PVP) with a second cationic site, such that the two anion-exchange sites are linked by 'spacer' arms of varying length and flexibility. The overall objective of our research is to develop a predictive capability that allows the facile design and implementation of multi-functionalized anion-exchange materials to selectively sorb metal complexes of interest from targeted process, waste, and environmental streams. Various Focus Areas and Crosscutting Programs have described needs that would be favorably impacted by the new materials:Tanks, Plutonium; Subsurface Contaminants; Mixed Waste; and Efficient Separations. Sites within the DOE complex which would benefit from the improved anion exchange technology include Hanford, Idaho, Los Alamos, Oak Ridge, and Savannah River.

  8. 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.

  9. Hydraulic Permeability of Resorcinol-Formaldehyde Ion-Exchange Resin - Effects of Oxygen Uptake and Radiation

    SciTech Connect

    Taylor, Paul Allen

    2009-01-01

    An ion-exchange process, using spherical resorcinol-formaldehyde (RF) resin is the baseline process for removing cesium from the dissolved salt solution in the high-level waste tanks at the U.S. Department of Energy's (DOE) Hanford site in Washington State. The RF resin is also being evaluated for use in the proposed Small Column Ion Exchange (SCIX) system, which is an alternative treatment option at DOE's Savannah River Site (SRS)in South Carolina. Testing at ORNL will determine the impact of radiation exposure and oxygen uptake by the RF resin on the hydraulic permeability of the resin. Samples of the resin will be removed periodically to measure physical properties (bead size and compressibility) and cesium capacity. The proposed full-scale treatment system at Hanford, the Waste Treatment Plant (WTP), will use an ion-exchange column containing nominally 680 gal of resin, which will treat 30 gpm of waste solution. The ion-exchange column is designed for a typical pressure drop of 6 psig, with a maximum of 9.7 psig. The lab-scale column is 3-in. clear PVC pipe and is prototypic of the proposed Hanford column. The fluid velocity in the lab-scale test will be much higher than for the full-scale column, in order to generate the maximum pressure drop expected in that column (9.7 psig). The frictional drag from this high velocity will produce similar forces on the resin in the lab-scale column as would be expected at the bottom of the full-scale column. The chemical changes in the resin caused by radiation exposure and oxygen uptake are expected to cause physical changes in the resin that could reduce the bed porosity and reduce the hydraulic permeability of the resin bed. These changes will be monitored by measuring the pressure drop through the lab-scale column and by measuring the physical properties of samples of the resin. The test loop with the lab-scale column is currently being fabricated, and operation will start by late May. Testing will be completed by the

  10. Comparison of XAD macroporous resins for the concentration of fulvic acid from aqueous solution

    USGS Publications Warehouse

    Aiken, G.R.

    1979-01-01

    Five macroreticular, nonlonlc AmberlHe XAD resins were evaluated for concentration and Isolation of fulvlc acid from aqueous solution. The capacity of each resin for fulvlc acid was measured by both batch and column techniques. Elution efficiencies were determined by desorptlon with 0.1 N NaOH. Highest recoveries were obtained with the acrylic ester resins which proved to be most efficient for both adsorption and elution of fulvlc acid. Compared to the acrylic ester resins, usefulness of the styrene dvlnybenzene resins to remove fulvlc acid is limited because of slow diffusion-controlled adsorption and formation of charge-transfer complexes, which hinders elution. ?? 1979 American Chemical Society.

  11. Retention behavior of C1-C6 aliphatic monoamines on anion-exchange and polymethacrylate resins with heptylamine as eluent.

    PubMed

    Ohta, Kazutoku; Ohashi, Masayoshi; Jin, Ji-Ye; Takeuchi, Toyohide; Fujimoto, Chuzo; Choi, Seong-Ho; Ryoo, Jae Jeong; Lee, Kwang-Pill

    2004-06-11

    Retention behavior of C1-C6, aliphatic monoamines (methylamine, ethylamine, propylamine, butylamine, amylamine and hexylamine) on columns (150 mm x 6 mm i.d.) packed with various anion-exchange resins (styrene-divinylbenzene (PS-DVB) copolymer-based strongly basic anion-exchange resin: TSKgel SAX, polymethacrylate-based strongly basic anion-exchange resin: TSKgel SuperQ-5PW and polymethacrylate-based weakly basic anion-exchange resin: TSKgel DEAE-5PW) and unfunctionized polymethacrylate resins (TSKgel G5000PW and TSKgel G3000PWXL) was investigated with basic solutions (sodium hydroxide and heptylamine) as the eluents. Due to strongly electrostatic repulsion (ion-exclusion effect) between these anion-exchange resins and these amines, peak resolution between these amines on these anion-exchange resin columns was unsatisfactory with both sodium hydroxide and heptylamine as the eluents. In contrast, these polymethacrylate resins were successfully applied as the stationary phases for the separation of these C1-C6 amines with heptylamine as eluent, because of both small hydrophobicity and small cation-exchange ability of these resins. Excellent simultaneous separation, highly sensitive conductimetric detection and symmetrical peaks for these C1-C6 amines were achieved on the TSKgel G3000PWXL column in 35 min with 5 mM heptylamine at pH 11.1 as the eluent. PMID:15250421

  12. Polystyrene sulphonic acid resins with enhanced acid strength via macromolecular self-assembly within confined nanospace

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaomin; Zhao, Yaopeng; Xu, Shutao; Yang, Yan; Liu, Jia; Wei, Yingxu; Yang, Qihua

    2014-01-01

    Tightening environmental legislation is driving the chemical industries to develop efficient solid acid catalysts to replace conventional mineral acids. Polystyrene sulphonic acid resins, as some of the most important solid acid catalysts, have been widely studied. However, the influence of the morphology on their acid strength—closely related to the catalytic activity—has seldom been reported. Herein, we demonstrate that the acid strength of polystyrene sulphonic acid resins can be adjusted through their reversible morphology transformation from aggregated to swelling state, mainly driven by the formation and breakage of hydrogen bond interactions among adjacent sulphonic acid groups within the confined nanospace of hollow silica nanospheres. The hybrid solid acid catalyst demonstrates high activity and selectivity in a series of important acid-catalysed reactions. This may offer an efficient strategy to fabricate hybrid solid acid catalysts for green chemical processes.

  13. Performance testing of grout-based waste forms for the solidification of anion exchange resins

    SciTech Connect

    Morgan, I.L.; Bostick, W.D.

    1990-10-01

    The solidification of spent ion exchanges resins in a grout matrix as a means of disposing of spent organic resins produced in the nuclear fuel cycle has many advantages in terms of process simplicity and economy, but associated with the process is the potential for water/cement/resins to interact and degrade the integrity of the waste form solidified. Described in this paper is one possible solution to preserving the integrity of these solidified waste forms: the encapsulation of beaded anion exchange resins in grout formulations containing ground granulated blast furnace slag, Type I-II (mixed) portland cement, and additives (clays, amorphous silica, silica fume, and fly ash). The results of the study reported herein show the cured waste form tested has a low leach rate for nitrate ion from the resin (and a low leach rate is inferred for Tc-99) and acceptable durability as assessed by the water immersion and freezing/thawing test protocols. The results also suggest a tested surrogate waste form prepared in vinyl ester styrene binder performs satisfactorily against the wetting/drying criterion, and it should offer additional insight into future work on the solidification of spent organic resins. 26 refs., 4 figs., 5 tabs.

  14. A continuous process for biodiesel production in a fixed bed reactor packed with cation-exchange resin as heterogeneous catalyst.

    PubMed

    Feng, Yaohui; Zhang, Aiqing; Li, Jianxin; He, Benqiao

    2011-02-01

    Continuous esterification of free fatty acids (FFA) from acidified oil with methanol was carried out with NKC-9 cation-exchange resin in a fixed bed reactor with an internal diameter of 25 mm and a height of 450 mm to produce biodiesel. The results showed that the FFA conversion increased with increases in methanol/oil mass ratio, reaction temperature and catalyst bed height, whereas decreased with increases in initial water content in feedstock and feed flow rate. The FFA conversion kept over 98.0% during 500 h of continuous esterification processes under 2.8:1 methanol to oleic acid mass ratio, 44.0 cm catalyst bed height, 0.62 ml/min feed flow rate and 65°C reaction temperature, showing a much high conversion and operational stability. Furthermore, the loss of sulfonic acid groups from NKC-9 resin into the production was not found during continuous esterification. In sum, NKC-9 resin shows the potential commercial applications to esterification of FFA. PMID:21078550

  15. Selective Anion Exchange Resins for the Removal of Perchlorate [(CIO{sub 4}{sup -})] from Groundwater

    SciTech Connect

    Gu, B.

    1999-05-20

    The primary objective of this project was to evaluate a novel bifunctional anion exchange resin for the cost-effective, in situ treatment of groundwater contaminated with perchlorate (ClO{sub 4}{sup -}). Both laboratory and field studies were performed to determine the selectivity and capacity of the bifunctional synthetic resins to sorb ClO{sub 4}{sup -} from simulated or actual contaminated groundwater. A number of synthetic bifunctional resins, including two commercial versions made by Purolite International and three commercially available, mono-functional resins, were tested. Initial laboratory batch and column breakthrough studies determined the best synthetic resins and the optimal conditions for the field experiment. Laboratory results indicated that the bifunctional synthetic resins, D-3696 and RO-02-119 were highly selective toward ClO{sub 4}{sup -} and performed {approx}5 times better than the best commercial nitrate resin (Purolite{reg_sign} A-520E) and more than an order of magnitude better than some nonselective commercial resins (e.g. Amberlite{reg_sign} IRA-900). The bifunctional resins were particularly effective in removing trace quantities of ClO{sub 4}{sup -} in groundwater to below the detection limit ({approx} 3 {micro}g/L). A field trial demonstrated that the bifunctional resin (D-3696) was able to treat {approx} 110,000 bed volumes of groundwater before a 10% breakthrough of ClO{sub 4}{sup -} occurred under the column flow-through conditions (running at {approx} 2 bed volumes per minute). On the other hand, the Purolite{reg_sign} A-520E resin was able to treat {approx} 23,000 bed volumes of groundwater under the same experimental conditions. No pretreatment was needed to remove either dissolved organic matter or other competing anions (such as SO{sub 4}{sup 2-} or NO{sub 3}{sup -}) in the groundwater, and the treatment process did not alter the water quality by removing or adding secondary by-products because of the high selectivity of the

  16. Batch and fixed-bed assessment of sulphate removal by the weak base ion exchange resin Amberlyst A21.

    PubMed

    Guimarães, Damaris; Leão, Versiane A

    2014-09-15

    This paper investigated sulphate removal from aqueous solutions by Amberlyst A21, a polystyrene weak base ion exchange resin. Both the pH and initial sulphate concentration were observed to strongly affect sorption yields, which were largest in acidic environments. Working under optimum operational conditions, sulphate sorption by Amberlyst A21 was relatively fast and reached equilibrium after 45 min of contact between the solid and liquid phases. Sorption kinetics could be described by either the pseudo-first order (k1=3.05 × 10(-5)s(-1)) or pseudo-second order model (k2=1.67 × 10(-4)s(-1)), and both the Freundlich and Langmuir models successfully fitted the equilibrium data. Sulphate uptake by Amberlyst A21 was a physisorption process (ΔH=-25.06 kJ mol(-1)) that occurred with entropy reduction (ΔS=-0.042 kJ mol(-1)K(-1)). Elution experiments showed that sulphate is easily desorbed (∼ 100%) from the resin by sodium hydroxide solutions at pH 10 or pH 12. Fixed-bed experiments assessed the effects of the initial sulphate concentration, bed height and flow rate on the breakthrough curves and the efficiency of the Amberlyst A21 in the treatment of a real effluent. In all studied conditions, the maximum sulphate loading resin varied between 8 and 40 mg(SO4(2-))mL(resin)(-1). PMID:25151243

  17. Removal of chromium from electroplating industry effluents by ion exchange resins.

    PubMed

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

    2007-06-18

    Effluent discharged from the chromium electroplating industry contains a large number of metals, including chromium, copper, nickel, zinc, manganese and lead. The ion exchange process is an alternative technique for application in the treatment of industrial wastewater containing heavy metals and indeed it has proven to be very promising in the removal and recovery of valuable species. The main objective of the present work is to evaluate the performance of commercial ion exchange resins for removing chromium trivalent from industrial effluents, and for this purpose two resins were tested: a chelating exchange resin (Diaion CR11) and a weak cationic resin (Amberlite IRC86). In order to evaluate the sorption capacity of the resins some equilibrium experiments were carried out, being the temperature and pH the main variables considered. The chromium solutions employed in the experiments were synthetic solutions and industrial effluents. In addition, a transient test was also performed as an attempt to understand the kinetic behaviour of the process. PMID:17336455

  18. Development of Volume-Reduction System for Ion Exchange Resin Using Inductively Coupled Plasma

    NASA Astrophysics Data System (ADS)

    Fujisawa, Morio; Katagiri, Genichi

    The spent ion exchange resin generated as radioactive waste in water purifying system at nuclear power stations or related facilities of nuclear power has been stored in the site, and its volume has been increasing year by year. We had developed a full-scale system of IC plasma volume-reduction system for the spent resin, and have performed basic performance test using some samples imitating the spent resin. As the results, the imitation of the resin can be reduced in volume by more than 90% so that the processing performance in actual scale was proved to be effective. In addition, it was clarified that the residuum after volume-reduction process is easy to mix with cement, and solidity containing 30wt% residuum provides high strength of 68MPa. Therefore, we evaluate the application of this process to stabilization of the disposal to be very effective.

  19. 1-Butanol absorption in poly(styrene-divinylbenzene) ion exchange resins for catalysis.

    PubMed

    Pérez-Maciá, M A; Curcó, D; Bringué, R; Iborra, M; Rodríguez-Ropero, F; van der Vegt, N F A; Aleman, Carlos

    2015-12-21

    The swelling behaviour of poly(styrene-co-divinylbenzene), P(S-DVB), ion exchange resins in 1-butanol (BuOH) has been studied by means of atomistic classical molecular dynamics simulations (MD). The topological characteristics reported for the resin in the dry state, which exhibited complex internal loops (macropores), were considered for the starting models used to examine the swelling induced by BuOH contents ranging from 10% to 50% w/w. Experimental measurements using a laser diffraction particle size analyzer indicate that swelling causes a volume variation with respect to the dry resin of 21%. According to MD simulations, such a volume increment corresponds to a BuOH absorption of 31-32% w/w, which is in excellent agreement with the indirect experimental estimation (i.e. 31% w/w). Simulations reveal that, independently of the content of BuOH, the density of the swelled resin is higher than that of the dry resin, evidencing that the alcohol provokes important structural changes in the polymeric matrix. Thus, BuOH molecules cause a collapse of the resin macropores when the content of alcohol is ≤20% w/w. In contrast, when the concentration of BuOH is close to the experimental value (∼30% w/w), P(S-DVB) chains remain separated by pores faciliting the access of the reactants to the reaction centers. On the other hand, evaluation of both bonding and non-bonding interactions indicates that the mixing energy is the most important contribution to the absorption of BuOH into the P(S-DVB) resin. Overall, the results displayed in this work represent a starting point for the theoretical study of the catalytic conversion of BuOH into di-n-butyl ether in P(S-DVB) ion exchange resins using sophisticated electronic methods. PMID:26411792

  20. 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.

  1. New anion-exchange resins for improved separations of nuclear materials. Mid-year progress report

    SciTech Connect

    Barr, M.E.

    1997-06-01

    'The authors are developing multi-functional anion-exchange resins that facilitate anion uptake by carefully controlling the structure of the anion receptor site. The new ion-exchange resins interface the rapidly developing field of ion-specific chelating ligands with robust, commercial ion exchange technology. The overall objective of the research is to develop a predictive capability which allows the facile design and implementation of multi-functionalized anion exchange materials which selectively sorb metal complexes of interest from targeted process, waste, and environmental streams. The basic scientific issues addressed are actinide complex speciation along with modeling of the metal complex/functional site interactions in order to determine optimal binding-site characteristics. Their approach uses a thorough determination of the chemical species both in solution and as bound to the resin to determine the characteristics of resin active sites which can actively facilitate specific metal-complex sorption to the resin. The first year milestones were designed to allow us to build off of their extensive expertise with plutonium in nitrate solutions prior to investigating other, less familiar systems. While the principle investigators have successfully developed actinide chelators and ion-exchange materials in the past, the authors were fully aware that integration of this two fields would be challenging, rewarding and, at times, highly frustrating. Relatively small differences in the substrate (cross-linkage, impurities), the active sites (percent substitution, physical accessibility), the actinide solution (oxidation state changes, purity) and the analytical procedures (low detection limits) can produce inconsistent sorption behavior which is difficult to interpret. The potential paybacks for success, however, are enormous. They feel that they have learned a great deal about how to control these numerous variables to produce consistent, reliable analysis of

  2. Uptake of metal ions by a new chelating ion exchange resin. Part 3: Protonation constants via potentiometric titration and solid state [sup 31]P NMR spectroscopy

    SciTech Connect

    Nash, K.L.; Rickert, P.G.; Muntean, J.V.; Alexandratos, S.D.

    1994-01-01

    A new chelating ion exchange resin which incorporates methylenediphosphonate, carboxylate, and sulfonate functional groups in a polystyrene-divinylbenzene matrix has been prepared. This resin exhibits exceptionally high affinity for polyvalent cations even from moderately acidic aqueous media. Metal ion coordination occurs primarily at the diphosphonate group with the secondary binding sites contributing to charge neutralization when necessary and possible, and to increasing hydrophilicity of the resin pores. In the present investigation, the protonation equilibria of the phosphonate groups in the resin are investigated via potentiometric titration and solid-state [sup 31]P NMR spectroscopy of the resin. Intrinsic equilibrium constants for the first two diphosphonate protonation reactions are pK[sub 4] = 10.47 and pK[sub 3] = 7.24. The last two protons added to the diphosphonate group are acidic having pK[sub a] values less than 2.5. These protonation constants are consistent with those reported previously for monomer analog 1,1-diphosphonic acids. This result implies that thermodynamic data available in the literature can be used to predict the relative affinity of the resin for polyvalent cations. 17 refs., 2 figs., 3 tabs.

  3. Improvement of technology for treatment of spent radioactive ion-exchange resins at nuclear power stations

    NASA Astrophysics Data System (ADS)

    Korchagin, Yu. P.; Aref'ev, E. K.; Korchagin, E. Yu.

    2010-07-01

    Results from tests of technology for decontaminating spent radioactive ion-exchange resins at the Balakovo and Kalinin nuclear power stations are presented. Versions of technological schemes with cleaning and repeated use of decontaminating solution are considered. The possibility of considerably reducing the volume of radioactive wastes is demonstrated.

  4. Investigation of an anion exchange resin for cleanup of a coolant used to machine nuclear materials

    SciTech Connect

    Hinton, E.R. Jr.; Tucker, H.L.; Asbury, W.L.

    1986-01-01

    This article describes the interaction of Dowex SBR-P, which is a strongly basic anion exchange resin, with ions found in a used machining coolant. The coolant is used in machining enriched uranium and contains uranium, chloride, nitrite, borate ions, water, and propylene glycol.

  5. EFFECTS OF PH AND COMPETING ANIONS ON THE SOLUTION SPECIATION OF ARSENIC BY ION EXCHANGE RESINS

    EPA Science Inventory

    Anion-exchange resins (AER) are used to differentiate As(V) and As(III) by retaining As(V) and allowing As(III) to pass through. AERs allow rapid speciation of As in the field which precludes the effects sample preservation on As speciation. Aqueous environmental samples contai...

  6. Sulfur geochemistry of hydrothermal waters in Yellowstone National Park, Wyoming, USA. III. An anion-exchange resin technique for sampling and preservation of sulfoxyanions in natural waters

    PubMed Central

    Druschel, Greg K; Schoonen, Martin AA; Nordstrom, D Kirk; Ball, James W; Xu, Yong; Cohn, Corey A

    2003-01-01

    A sampling protocol for the retention, extraction, and analysis of sulfoxyanions in hydrothermal waters has been developed in the laboratory and tested at Yellowstone National Park and Green Lake, NY. Initial laboratory testing of the anion-exchange resin Bio-Rad™ AG1-X8 indicated that the resin was well suited for the sampling, preservation, and extraction of sulfate and thiosulfate. Synthetic solutions containing sulfate and thiosulfate were passed through AG1-X8 resin columns and eluted with 1 and 3 M KCl, respectively. Recovery ranged from 89 to 100%. Comparison of results for water samples collected from five pools in Yellowstone National Park between on-site 1C analysis (U.S. Geological Survey mobile lab) and IC analysis of resin-stored sample at SUNY-Stony Brook indicates 96 to 100% agreement for three pools (Cinder, Cistern, and an unnamed pool near Cistern) and 76 and 63% agreement for two pools (Sulfur Dust and Frying Pan). Attempts to extract polythionates from the AG1-X8 resin were made using HCl solutions, but were unsuccessful. Bio-Rad™ AG2-X8, an anion-exchange resin with weaker binding sites than the AG1-X8 resin, is better suited for polythionate extraction. Sulfate and thiosulfate extraction with this resin has been accomplished with KCl solutions of 0.1 and 0.5 M, respectively. Trithionate and tetrathionate can be extracted with 4 M KCl. Higher polythionates can be extracted with 9 M hydrochloric acid. Polythionate concentrations can then be determined directly using ion chromatographic methods, and laboratory results indicate recovery of up to 90% for synthetic polythionate solutions using AG2-X8 resin columns.

  7. Sulfur geochemistry of hydrothermal waters in Yellowstone National Park, Wyoming, USA. III. An anion-exchange resin technique for sampling and preservation of sulfoxyanions in natural waters

    USGS Publications Warehouse

    Druschel, G.K.; Schoonen, M.A.A.; Nordstorm, D.K.; Ball, J.W.; Xu, Y.; Cohn, C.A.

    2003-01-01

    A sampling protocol for the retention, extraction, and analysis of sulfoxyanions in hydrothermal waters has been developed in the laboratory and tested at Yellowstone National Park and Green Lake, NY. Initial laboratory testing of the anion-exchange resin Bio-Rad??? AG1-X8 indicated that the resin was well suited for the sampling, preservation, and extraction of sulfate and thiosulfate. Synthetic solutions containing sulfate and thiosulfate were passed through AG1-X8 resin columns and eluted with 1 and 3 M KCl, respectively. Recovery ranged from 89 to 100%. Comparison of results for water samples collected from five pools in Yellowstone National Park between on-site IC analysis (U.S. Geological Survey mobile lab) and IC analysis of resin-stored sample at SUNY-Stony Brook indicates 96 to 100% agreement for three pools (Cinder, Cistern, and an unnamed pool near Cistern) and 76 and 63% agreement for two pools (Sulfur Dust and Frying Pan). Attempts to extract polythionates from the AG1-X8 resin were made using HCl solutions, but were unsuccessful. Bio-Rad??? AG2-X8, an anion-exchange resin with weaker binding sites than the AG1-X8 resin, is better suited for polythionate extraction. Sulfate and thiosulfate extraction with this resin has been accomplished with KCl solutions of 0.1 and 0.5 M, respectively. Trithionate and tetrathionate can be extracted with 4 M KCl. Higher polythionates can be extracted with 9 M hydrochloric acid. Polythionate concentrations can then be determined directly using ion chromatographic methods, and laboratory results indicate recovery of up to 90% for synthetic polythionate solutions using AG2-X8 resin columns. ?? The Royal Society of Chemistry and the Division of Geochemistry of the American Chemical Society 2003.

  8. Corrosion of steel drums containing cemented ion-exchange resins as intermediate level nuclear waste

    NASA Astrophysics Data System (ADS)

    Duffó, G. S.; Farina, S. B.; Schulz, F. M.

    2013-07-01

    Exhausted ion-exchange resins used in nuclear reactors are immobilized by cementation before being stored. They are contained in steel drums that may undergo internal corrosion depending on the presence of certain contaminants. The objective of this work is to evaluate the corrosion susceptibility of steel drums in contact with cemented ion-exchange resins with different aggressive species. The corrosion potential and the corrosion rate of the steel, and the electrical resistivity of the matrix were monitored for 900 days. Results show that the cementation of ion-exchange resins seems not to pose special risks regarding the corrosion of the steel drums. The corrosion rate of the steel in contact with cemented ion-exchange resins in the absence of contaminants or in the presence of 2.3 wt.% sulphate content remains low (less than 0.1 μm/year) during the whole period of the study (900 days). The presence of chloride ions increases the corrosion rate of the steel at the beginning of the exposure but, after 1 year, the corrosion rate drops abruptly reaching a value close to 0.1 μm/year. This is probably due to the lack of water to sustain the corrosion process. When applying the results obtained in the present work to estimate the corrosion depth of the steel drums containing the cemented radioactive waste after a period of 300 years, it is found that in the most unfavourable case (high chloride contamination), the corrosion penetration will be considerably lower than the thickness of the wall of the steel drums. Cementation of ion-exchange resins does not seem to pose special risks regarding the corrosion of the steel drums that contained them; even in the case the matrix is highly contaminated with chloride ions.

  9. Evaluation of anion exchange resins Tulsion A-30 and Indion-930A by application of radioanalytical technique

    NASA Astrophysics Data System (ADS)

    Singare, P. U.

    2014-07-01

    Radioanalytical technique using 131I and 82Br was employed to evaluate organic based anion exchange resins Tulsion A-30 and Indion-930A. The evaluation was based on performance of these resins during iodide and bromide ion-isotopic exchange reactions. It was observed that for iodide ion-isotopic exchange reaction by using Tulsion A-30 resin, the values of specific reaction rate (min-1), amount of iodide ion exchanged (mmol), initial rate of iodide ion exchange (mmol/min) and log K d were 0.238, 0.477, 0.114, and 11.0, respectively, which was higher than 0.155, 0.360, 0.056, and 7.3, respectively as that obtained by using Indion-930A resins under identical experimental conditions of 40.0°C, 1.000 g of ion exchange resins and 0.003 M labeled iodide ion solution. Also at a constant temperature of 40.0°C, as the concentration of labeled iodide ion solution increases 0.001 to 0.004 M, for Tulsion A-30 resins the percentage of iodide ions exchanged increases from 59.0 to 65.1%, and from 46.4 to 48.8% for Indion-930A resins under identical experimental conditions. The identical trend was observed for both the resins during bromide ion-isotopic exchange reactions. The overall results indicate that under identical experimental conditions, Tulsion A-30 show superior performance over Indion-930A resins. The results of present experimental work have demonstrated that the radioanalytical technique used here can be successfully applied for characterization of different ion exchange resins so as to evaluate their performance under various process parameters.

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

    SciTech Connect

    Aleman, S.; Hamm, L.; Smith, F.

    2007-06-27

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

  11. ION EXCHANGE MODELING FOR REMOVAL OF CESIUM FROM HANFORD WASTE USING SUPERLIG 644 RESIN

    SciTech Connect

    Hamm, L

    2004-05-01

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

  12. Using Process Knowledge to Manage Disposal Classification of Ion-Exchange Resin - 13566

    SciTech Connect

    Bohnsack, Jonathan N.; James, David W.

    2013-07-01

    It has been previously shown by EPRI [1] that Class B and C resins represent a small portion by volume of the overall generation of radioactively contaminated resins. In fact, if all of the resins were taken together the overall classification would meet Class A disposal requirements. Lowering the classification of the ion exchange resins as they are presented for disposal provides a path for minimizing the amount of waste stored. Currently there are commercial options for blending wastes from various generators for Class A disposal in development. The NRC may have by this time introduced changes and clarifications to the Branch Technical Position (BTP) on Concentration Averaging and Encapsulation [2] that may ultimately add more flexibility to what can be done at the plant level. The BTP has always maintained that mixtures of resins that are combined for ALARA purposes or operational efficiency can be classified on the basis of the mixture. This is a point often misinterpreted and misapplied. This paper will address options that can be exercised by the generator that can limit B and C waste generation by more rigorous tracking of generation and taking advantage of the normal mix of wastes. This can be achieved through the monitoring of reactor coolant chemistry data and coupled with our knowledge of radionuclide production mechanisms. This knowledge can be used to determine the overall accumulation of activity in ion-exchange resins and provides a 'real-time' waste classification determination of the resin and thereby provide a mechanism to reduce the production of waste that exceeds class A limits. It should be noted that this alternative approach, although rarely used in a nuclear power plant setting, is acknowledged in the original BTP on classification [3] as a viable option for determining radionuclide inventories for classification of waste. Also included is a discussion of an examination performed at the Byron plant to estimate radionuclide content in the

  13. Biodiesel production from yellow horn (Xanthoceras sorbifolia Bunge.) seed oil using ion exchange resin as heterogeneous catalyst.

    PubMed

    Li, Ji; Fu, Yu-Jie; Qu, Xue-Jin; Wang, Wei; Luo, Meng; Zhao, Chun-Jian; Zu, Yuan-Gang

    2012-03-01

    In this study, biodiesel production from yellow horn (Xanthoceras sorbifolia Bunge.) seed oil using ion exchange resin as heterogeneous catalyst was investigated. After illustration of the mechanisms of transesterification reactions catalyzed by typical ion exchange resins, the factors affecting microwave-assisted transesterification process were studied. A high conversion yield of about 96% was achieved under optimal conditions using high alkaline anion exchange resins as catalyst. Analyzing the FAMEs composition by GC-MS and main physical-chemical properties demonstrated that the biodiesel product prepared from yellow horn seed oil was of high quality. Compared with conventional alkali catalyst, the outstanding characteristics of reusability and operational stability made the resin catalyst more predominant for biodiesel production. In addition, a comprehensive kinetic model was established for analyzing the reaction. The results of present research showed that microwave-assisted transesterification process catalyzed by high alkaline anion exchange resin was a green, effective and economic technology for biodiesel industry. PMID:22284757

  14. 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.

  15. Effect of blastfurnace slag addition to Portland cement for cationic exchange resins encapsulation

    NASA Astrophysics Data System (ADS)

    Lafond, E.; Cau Dit Coumes, C.; Gauffinet, S.; Chartier, D.; Le Bescop, P.; Stefan, L.; Nonat, A.

    2013-07-01

    In the nuclear industry, cement-based materials are extensively used to encapsulate spent ion exchange resins (IERs) before their final disposal in a repository. It is well known that the cement has to be carefully selected to prevent any deleterious expansion of the solidified waste form, but the reasons for this possible expansion are not clearly established. This work aims at filling the gap. The swelling pressure of IERs is first investigated as a function of ions exchange and ionic strength. It is shown that pressures of a few tenths of MPa can be produced by decreases in the ionic strength of the bulk solution, or by ion exchanges (2Na+ instead of Ca2+, Na+ instead of K+). Then, the chemical evolution of cationic resins initially in the Na+ form is characterized in CEM I (Portland cement) and CEM III (Portland cement + blastfurnace slag) cements at early age and an explanation is proposed for the better stability of CEM III material.

  16. Mathematical modelling and reactor design for multi-cycle bioregeneration of nitrate exhausted ion exchange resin.

    PubMed

    Ebrahimi, Shelir; Roberts, Deborah J

    2016-01-01

    Nitrate contamination is one of the largest issues facing communities worldwide. One of the most common methods for nitrate removal from water is ion exchange using nitrate selective resin. Although these resins have a great capacity for nitrate removal, they are considered non regenerable. The sustainability of nitrate-contaminated water treatment processes can be achieved by regenerating the exhausted resin several times rather than replacing and incineration of exhausted resin. The use of multi-cycle exhaustion/bioregeneration of resin enclosed in a membrane has been shown to be an effective and innovative regeneration method. In this research, the mechanisms for bioregeneration of resin were studied and a mathematical model which incorporated physical desorption process with biological removal kinetics was developed. Regardless of the salt concentration of the solution, this specific resin is a pore-diffusion controlled process (XδD ¯CDr0(5+2α)<1). Also, Thiele modulus was calculated to be between 4 and 12 depending on the temperature and salt concentration. High Thiele modulus (>3) shows that the bioregeneration process is controlled by reaction kinetics and is governed by biological removal of nitrate. The model was validated by comparison to experimental data; the average of R-squared values for cycle 1 to 5 of regeneration was 0.94 ± 0.06 which shows that the developed model predicted the experimental results very well. The model sensitivity for different parameters was evaluated and a model bioreactor design for bioregeneration of highly selective resins was also presented. PMID:26595098

  17. Removal of aqueous cyanide with strongly basic ion-exchange resin.

    PubMed

    Simsek, Halis; Kobya, Mehmet; Khan, Eakalak; Bezbaruah, Achintya N

    2015-01-01

    The removal of cyanide (CN-) from aqueous solutions using a strongly basic ion-exchange resin, Purolite A-250, was investigated. The effects of contact time, initial CN- concentration, pH, temperature, resin dosage, agitation speed, and particle size distribution on the removal of CN- were examined. The adsorption equilibrium data fitted the Langmuir isotherm very well. The maximum CN- adsorption capacity of Purolite A-250 was found to be 44 mg CN- g(-1) resin. More than 90% CN- adsorption was achieved for most CN- solutions (50, 100, and 200 mg CN- L(-1)) with a resin dose of 2 g L(-1). The equilibrium time was ∼20 min, optimum pH was 10.0-10.5, and optimum agitation speed was 150 rpm. An increase in adsorption of CN- with increasing resin dosage was observed. Adsorption of CN- by the resin was marginally affected (maximum 4% variation) within an environmentally relevant temperature range of 20-50 °C. Fixed-bed column (20.5 mm internal diameters) experiments were performed to investigate the effects of resin bed depth and influent flow rate on breakthrough behaviour. Breakthrough occurred in 5 min for 0.60 cm bed depth while it was 340 min for 5.40 cm bed depth. Adsorption capacity was 25.5 mg CN- g(-1) for 5 mL min(-1) flow rate and 3.9 mg CN- g(-1) for 20 mL min(-1) flow rate. The research has established that the resin can be effectively used for CN- removal from aqueous solutions. PMID:25558868

  18. Evaluation of ion exchange resins and various enzymes in thiamine analysis.

    PubMed

    Ellefson, W C; Richter, E; Adams, M; Baillies, N T

    1981-11-01

    Four ion exchange resins and 9 enzyme preparations are evaluated for use in the official AOAC thiamine method because Decalso and Clarase or Mylase P either are no longer available or are available in a form that is not suitable for use in the assay. The enzymes are prepared in the same manner described for Clarase or Mylase P in the AOAC method and are compared with Clarase T300 for their effectiveness in releasing thiamine from thiamine phosphate, and their ability to produce similar results on samples. Rhozyme S is 90-100% as effective as Clarase T300 in both of these respects. The other enzymes tested were not satisfactory. Further study is necessary because Rhozyme S also is no longer manufactured. The ion exchange resins are prepared for use in the manner described for Decalso in the AOAC method. Recoveries of thiamine range from 95 to 100%, using Bio-Rex 70 (hydrogen form) ion exchange resin. The other resins tested were not satisfactory. PMID:7309654

  19. Removal of natural organic matter from water using ion-exchange resins and cyclodextrin polyurethanes

    NASA Astrophysics Data System (ADS)

    Nkambule, T. I.; Krause, R. W.; Mamba, B. B.; Haarhoff, J.

    Natural organic matter (NOM) consists of a complex mixture of naturally occurring organic compounds. Although it is not considered toxic by itself, NOM present during water disinfection may result in the formation of disinfection by-products (DBPs), many of which are either carcinogenic or mutagenic. Although it is difficult to completely characterize NOM due to its complex and large structure, a consideration of its structure is necessary for a better understanding of the mechanism of NOM removal from water. In this study, water from the Vaalkop water treatment plant was characterized for its NOM composition by fractionation over ion-exchange resins. Fractionation at different pH with different resins resulted in the isolation of the neutral, basic and acidic fractions of both the hydrophobic and hydrophilic NOM. The hydrophilic basic fraction was found to be the most abundant fraction in the source water. Each of the isolated NOM fractions were percolated through cyclodextrin (CD) polyurethanes, resulting in an adsorption efficiency of between 6% and 33%. The acidic fractions were the most adsorbed fractions by the CD polyurethanes, while the neutral fractions being the least adsorbed. The water samples were then subjected to an ozonation regime at the treatment plant and then fractionated as before. As expected there were decreases of the neutral and basic fractions after ozonation. The application of CD polyurethanes to the fractions after ozonation resulted in a removal efficiency of up to 59%, nearly double that of the non-treated sample. Also, in the case of the ozone pre-treated samples, it was mainly the hydrophilic basic fraction which was removed. All the fractions were subjected to a chlorination test to determine the trihalomethane (THM) formation potential. All six NOM fractions resulted in THM formation, but the hydrophilic basic fraction was found to be the most reactive and formed the highest THM concentration. The effect of the combination of

  20. Affinity purification of the voltage-sensitive sodium channel from electroplax with resins selective for sialic acid

    SciTech Connect

    James, W.M.; Emerick, M.C.; Agnew, W.S. )

    1989-07-11

    The voltage-sensitive sodium channel present in the eel (Electrophorus electricus) has an unusually high content of sialic acid, including {alpha}-(2{yields}8)-linked polysialic acid, not found in other electroplax membrane glycopeptides. Lectins from Limax flavus (LFA) and wheat germ (WGA) proved the most effective of 11 lectin resins tried. The most selective resin was prepared from IgM antibodies against Neisseria meningitidis {alpha}-(2{yields}8)-polysialic acid which were affinity purified and coupled to Sepharose 4B. The sodium channel was found to bind to WGA, LFA, and IgM resins and was readily eluted with the appropriate soluble carbohydrates. Experiments with LFA and IgM resins demonstrated binding and unbinding rates and displacement kinetics, which suggest highly specific binding at multiple sites on the sodium channel protein. In preparative-scale purification of protein previously fractionated by anion-exchange chromatography, without stabilizing TTX, high yields were reproducibly obtained. Further, when detergent extracts were prepared from electroplax membranes fractionated by low-speed sedimentation, a single step over the IgM resin provided a 70-fold purification, yielding specific activities of 3,200 pmol of ({sup 3}H)TTX-binding sites/mg of protein and a single polypeptide of {approximately}285,000 Da on SDS-acrylamide gels. No small peptides were observed after this 5-h isolation. The authors describe a cation-dependent stabilization with millimolar levels of monovalent and micromolar levels of divalent species.

  1. REAL WASTE TESTING OF SPHERICAL RESORCINOL-FORMALDEHYDE ION EXCHANGE RESIN

    SciTech Connect

    Nash, C.; Duignan, M.

    2009-10-30

    This report presents data on batch contact and column testing tasks for spherical resorcinol-formaldehyde (sRF) resin. The testing used a non-radioactive simulant of SRS Tank 2F dissolved salt, as well as an actual radioactive waste sample of similar composition, which are both notably high in sodium (6 M). The resin was Microbeads batch 5E-370/641 which had been made on the hundred gallon scale. Equilibrium batch contact work focused on cesium at a temperature of 25 C due to the lack of such data to better benchmark existing isotherm models. Two campaigns were performed with small-scale ion exchange columns, first with Tank 2F simulant, then with actual dissolved salt in the Shielded Cells. An extrapolation of the batch contact results with radioactive waste over-predicted the cesium loaded onto the IX sRF resin bed by approximately 11%. This difference is not unexpected considering uncertainties from measurement and extrapolation and because the ion exchange that occurs when waste flows through a resin bed probably cannot reach the same level of equilibrium as when waste and resin are joined in a long term batch contact. Resin was also characterized to better understand basic chemistry issues such as holdup of trace transition metals present in the waste feed streams. The column tests involved using two beds of sRF resin in series, with the first bed referred to as the Lead column and the second bed as the Lag column. The test matrix included two complete IX cycles for both the simulant and actual waste phases. A cycle involves cesium adsorption, until the resin in the Lead column reaches saturation, and then regenerating the sRF resin, which includes eluting the cesium. Both the simulated and the actual wastes were treated with two cycles of operation, and the resin beds that were used in the Lead and Lag columns of simulant test phase were regenerated and reused in the actual waste test phase. This task is the first to demonstrate the treatment of SRS waste

  2. Two solid-phase recycling method for basic ionic liquid [C4mim]Ac by macroporous resin and ion exchange resin from Schisandra chinensis fruits extract.

    PubMed

    Ma, Chun-hui; Zu, Yuan-gang; Yang, Lei; Li, Jian

    2015-01-22

    In this study, two solid-phase recycling method for basic ionic liquid (IL) 1-butyl-3-methylimidazolium acetate ([C4mim]Ac) were studied through a digestion extraction system of extracting biphenyl cyclooctene lignans from Schisandra chinensis. The RP-HPLC detection method for [C4mim]Ac was established in order to investigate the recovery efficiency of IL. The recycling method of [C4mim]Ac is divided into two steps, the first step was the separation of lignans from the IL solution containing HPD 5000 macroporous resin, the recovery efficiency and purity of [C4mim]Ac achieved were 97.8% and 67.7%, respectively. This method cannot only separate the lignans from [C4mim]Ac solution, also improve the purity of lignans, the absorption rate of lignans in [C4mim]Ac solution was found to be higher (69.2%) than that in ethanol solution (57.7%). The second step was the purification of [C4mim]Ac by the SK1B strong acid ion exchange resin, an [C4mim]Ac recovery efficiency of 55.9% and the purity higher than 90% were achieved. Additionally, [C4mim]Ac as solvent extraction of lignans from S. chinensis was optimized, the hydrolysis temperature was 90°C and the hydrolysis time was 2h. PMID:25463641

  3. Development and Evaluation of Sustained Release Tablet of Betahistine Hydrochloride Using Ion Exchange Resin Tulsion T344

    PubMed Central

    Wagh, Vijay D.; Pawar, Nilesh

    2012-01-01

    An attempt was made to sustain the release of Betahistine hydrochloride by complexation technique using strong cation-exchange resin, Tulsion T344. The drug loading onto ion-exchange resin was optimized for mixing time, activation, effect of pH, swelling time, ratio of drug : resin, and temperature. The resinate was evaluated for micromeritic properties and characterized using XRPD and IR. For resinate sustained release tablets were formulated using hydoxypropyl methylcellulose K100M. The tablets were evaluated for hardness, thickness, friability, drug content, weight variation, and in vitro drug release. Tablets thus formulated (Batch T-3) provided sustained release of drug over a period of 12 h. The release of Betahistine HCl from resinate controls the diffusion of drug molecules through the polymeric material into aqueous medium. Results showed that Betahistine HCl was formulated into a sustained dosage form as an alternative to the conventional tablet. PMID:22779010

  4. Development and evaluation of sustained release tablet of betahistine hydrochloride using ion exchange resin tulsion t344.

    PubMed

    Wagh, Vijay D; Pawar, Nilesh

    2012-01-01

    An attempt was made to sustain the release of Betahistine hydrochloride by complexation technique using strong cation-exchange resin, Tulsion T344. The drug loading onto ion-exchange resin was optimized for mixing time, activation, effect of pH, swelling time, ratio of drug : resin, and temperature. The resinate was evaluated for micromeritic properties and characterized using XRPD and IR. For resinate sustained release tablets were formulated using hydoxypropyl methylcellulose K100M. The tablets were evaluated for hardness, thickness, friability, drug content, weight variation, and in vitro drug release. Tablets thus formulated (Batch T-3) provided sustained release of drug over a period of 12 h. The release of Betahistine HCl from resinate controls the diffusion of drug molecules through the polymeric material into aqueous medium. Results showed that Betahistine HCl was formulated into a sustained dosage form as an alternative to the conventional tablet. PMID:22779010

  5. Destruction of Ion-Exchange Resin In Waste From the HFIR, T1 and T2 Tanks Using Fenton's Reagent

    SciTech Connect

    Taylor, P.A.

    2002-11-06

    The use of Fenton's reagent (hydrogen peroxide and a ferrous iron catalyst) has been tested as a method for destroying ion-exchange resin in radioactive waste from three underground storage tanks at the Oak Ridge National Laboratory. The resin in these wastes must be destroyed before they can be transferred to the Melton Valley Storage Tanks (MVSTs) prior to solidification and disposal at the Waste Isolation Pilot Plant. The reaction with ion-exchange resin requires a dilute acidic solution (pH = 3 to 5) and moderate temperatures (T = 60 to 100 C). Laboratory-scale tests of the process have been successfully completed using both simulants and actual waste samples. The ion-exchange resin is oxidized to carbon dioxide and inorganic salts. The reaction rate is quite slow for temperatures below 70 C but increases almost linearly as the temperature of the slurry increases from 70 to 90 C. Pilot-scale tests have demonstrated the process using larger samples of actual waste slurries. A sample from the High Flux Isotope Reactor (HFIR) tank, containing 500 mL of settled solids (resin and inorganic sludge) in a total volume of 1800 mL, was successfully treated to meet MVST waste acceptance requirements in 9 h of processing time, using 1650 mL of 50 wt% hydrogen peroxide. A composite sample from the T1 and T2 tanks, which contained 1000 mL of settled solids in a total volume of 2000 mL required 8 h of treatment, using 1540 mL of 50 wt% peroxide, to meet waste acceptance requirements. Hydrogen peroxide reaction rates were 0.71 to 0.74 g H{sub 2}O{sub 2}/L/min, with very low (<2000 mg/L) concentrations of peroxide in the slurry. The reaction produces mostly carbon dioxide gas during the early part of the treatment, when organic carbon concentrations in the slurry are high, and then produces increasing amounts of oxygen as the organic carbon concentration drops. Small amounts (<3 vol%) of carbon monoxide are also generated. The off-gas from the pilot-scale tests, which was 81

  6. Radium-228 determination of natural waters via concentration on manganese dioxide and separation using Diphonix ion exchange resin.

    PubMed

    Nour, S; El-Sharkawy, A; Burnett, W C; Horwitz, E P

    2004-12-01

    The objective of this work was to establish a new procedure for 228Ra determination of natural waters via preconcentration of radium on MnO2 and separation of its daughter, 228Ac, using Diphonix ion exchange resin. Following removal of potential interferences via passage through an initial Diphonix Resin column, the first daughter of 228Ra, 228Ac, is isolated by chromatographic separation via a second Diphonix column. A holding time of > 30 h for 228Ac ingrowth in between the two column separations ensures secular equilibrium. Barium-133 is used as a yield tracer. Actinium-228 is eluted from the second Diphonix Resin with 5 ml 1M 1-Hydroxyethane-1,1-diphosphonic acid (HEDPA) and quantified by addition of scintillation cocktail and LSC counting. Radium (and 133Ba) from the load and rinse solutions from the 2nd Diphonix column may be prepared for alpha spectrometry (for determination of 223Ra, 224Ra, and 226Ra) by BaSO4 microprecipitation and filtration. Decontamination tests indicate that U, Th, and Ra series nuclides do not interfere with these measurements, although high contents of 90Sr (90Y) require additional treatment for accurate measurement of 228Ra. Addition of stable Sr as a "hold back" carrier during the initial MnO2 preconcentration step was shown to remove most 90Sr interference. PMID:15388106

  7. DEVELOPMENT OF WET-OXIDATION TREATMENT SYSTEM FOR FILTER BACKWASH SLUDGE AND ION EXCHANGE RESINS

    SciTech Connect

    Miyamoto, T.; Motoyama, M.; Shibuya, M.; Wada, H.; Yamazaki, K.

    2003-02-27

    Decomposition of organic compounds contained in filter backwash sludge and spent ion exchange resins is considered effective in reducing the waste volume. A system using the wet-oxidation process has been studied for the treatment of the sludge and resins stored at Tsuruga Power Station Unit 1, 357MWe BWR, owned by The Japan Atomic Power Company. Compared with various processes for treating sludge and resin, the wet-oxidation system is rather simple and the process conditions are mild. Waste samples collected from storage tanks were processed by wet-oxidation and appropriate decomposition of the organic compounds was verified. After the decomposition the residue can be solidified with cement or bitumen for final disposal. When compared with direct solidification without decomposition, the number of waste packages can be reduced by a factor of a few dozens for the sludge and three for the resin. Additional measures for conditioning secondary waste products have also been studied, and their applicability to the Tsuruga Power Station was verified. Some of the conditions studied were specific to the Tsuruga Power Station, but it is expected that the system will provide an effective solution for sludge and resin treatment at other NPPs.

  8. Semisynthesis of the antiviral abietane diterpenoid jiadifenoic acid C from callitrisic acid (4-epidehydroabietic acid) isolated from sandarac resin.

    PubMed

    González, Miguel A; Zaragozá, Ramón J

    2014-09-26

    The semisynthesis of the antiviral abietane diterpenoid (+)-jiadifenoic acid C starting from the available methyl ester of callitrisic acid (4-epidehydroabietic acid) isolated from sandarac resin is reported. A protocol for the isolation of methyl callitrisate (methyl 4-epidehydroabietate) in gram quantities from sandarac resin is also described. Allylic C-17 oxygenation was introduced by regioselective dehydrogenation of the isopropyl group of methyl callitrisate with DDQ followed by selenium-catalyzed allylic oxidation. Ester hydrolysis afforded (+)-jiadifenoic acid C in 22% overall yield from methyl callitrisate. This semisynthetic route provides a convenient source of this anti-Coxsackie virus B natural product for further biological studies. PMID:25166492

  9. LAB STUDY ON REGENERATION OF SPENT DOWEX 21K 16-20 MESH ION EXCHANGE RESIN

    SciTech Connect

    DUNCAN, J.B.

    2007-01-24

    Currently the effort to remove chromate from groundwater in the 100K and 100H Areas uses DOWEX 21K 16-20. This report addresses the procedure and results of a laboratory study for regeneration of the spent resin by sodium hydroxide, sulfuric acid, or sodium sulfate to determine if onsite regeneration by the Effluent Treatment Facility is a feasible option.

  10. COMBINED USE OF ION EXCHANGE RESINS AND GRANULAR ACTIVATED CARBON FOR THE CONTROL OF ORGANIC MATTER AND DISINFECTION BY PRODUCTS

    EPA Science Inventory

    The use of anion exchange resin as a pretreatment step to granular activated carbon is evaluated. erformance is evaluated by DOC, SAC, TOXFP, and THMFP parameters. hio River water and Palm Beach groundwater are used. he results show that resin pretreatment is significant in exten...

  11. Surface and line-edge roughness in acid-breakable resin-based positive resist

    NASA Astrophysics Data System (ADS)

    Sakamizu, Toshio; Shiraishi, Hiroshi

    2003-06-01

    A positive chemical amplification resist based on acid-catalyzed fragmentation of acetal groups in its main-chain has been developed as a means for reducing line-edge roughness. The resist consists of an acid-generator, an acid-diffusion controller and an acid-breakable (AB) resin that is synthesized through a co-condensation reaction between polyphenol and aromatic multi-functional vinylether compound. The effects of the fractionation of AB resins on resin properties and line-edge roughness (LER) are evaluated. Although AB resins have wide molecular-weight distributions, the density of acetal groups in this AB resin is found to be almost constant except in the lower molecular-weight components. The resist with a fractionated resin from which such components removed provides the high resolution of 60-nm line-and-space (L/S) patterns with fairly low LER. AFM analysis shows the surface roughness (SR) for the resist with the fractionated resin is smaller than that for a resist using non-fractionated AB resin, and that the SR value is not altered throughout the range of exposure doses up to just below the beginning of dissolution. By using the fractionated AB resin, the AB resin-based resist (ABR) is capable of forming sub-100 nm L/S patterns with less than 5 nm of LER (3σ).

  12. New anion-exchange resins for improved separations of nuclear materials

    SciTech Connect

    Barr, M.E.; Bartsch, R.A.

    1998-06-01

    'The overall objective of this research is to develop a predictive capability which allows the facile design and implementation of multi-functionalized anion-exchange materials which selectively sorb metal complexes of interest from targeted process, waste, and environmental streams. The basic scientific issues addressed are actinide complex speciation along with modeling of the metal complex/functional-site interactions in order to determine optimal binding-site characteristics. The new ion-exchange resins interface the rapidly developing field of ion-specific chelating ligands with robust, commercial ion-exchange technology. Various Focus Areas and Crosscutting Programs have described needs that would be favorably impacted by the new materials: Efficient Separations and Processing; Plutonium; Plumes; Mixed Waste; High-Level Tank Waste. Sites within the DOE complex which would benefit from the improved anion-exchange technology include Hanford, INEL, Los Alamos, Oak Ridge, and Savannah River. As of April 1998, this report summarizes work after 1.6 years of a 3-year project. The authors technical approach combines empirical testing with theoretical modeling (applied in an iterative mode) in order to determine optimal binding-site characteristics. They determine actinide-complex speciation in specific media, then develop models for the metal complex/functional-site interactions Synthesis and evaluation of multi-functionalized extractants and ion-exchange materials that implement key features of the optimized binding site provide feedback to the modeling and design activities. Resin materials which actively facilitate the uptake of actinide complexes from solution should display both improved selectivity and kinetic properties. The implementation of the bifunctionality concept involves N-derivatization of pyridinium units from a base poly(4-vinylpyridine) resin with a second cationic site such that the two anion-exchange sites are linked by spacer arms of varying

  13. Recovery of gallium(III) from strongly alkaline media using a Kelex-100-loaded ion-exchange resin

    SciTech Connect

    Nakayama, Morio; Egawa, Hiroaki

    1997-10-01

    Kelex-100 [7-(4-ethyl-1-methyloctyl)-8-hydroxyquinoline] is an important liquid-chelating ion exchanger in hydrometallurgy and a highly selective extractant for gallium (Ga). In this study, Kelex-100-loaded ion-exchange resins were prepared for the recovery of Ga(III) from sodium aluminate solutions (Bayer solution) used in the Bayer process. When macroporous type ion-exchange resins were used as polymer matrices for loading Kelex-100, the physical pore structure and the ion-exchange group significantly affected the adsorption of Ga(III) from strongly alkaline media on the Kelex-100-loaded resin. In particular, the Kelex-100-loaded carboxylic type resin having a macroporous structure showed a high capacity for Ga(III) in concentrated NaOH solution and effectively recovered Ga(III) from the Bayer solution containing large amounts of aluminum(III).

  14. Preliminary flowsheet: Ion exchange process for the separation of cesium from Hanford tank waste using Duolite{trademark} CS-100 resin

    SciTech Connect

    Eager, K.M.; Penwell, D.L.; Knutson, B.J.

    1994-12-01

    This preliminary flowsheet document describes an ion exchange process which uses Duolite{trademark} CS-100 resin to remove cesium from Hanford Tank waste. The flowsheet describes one possible equipment configuration, and contains mass balances based on that configuration with feeds of Neutralized Current Acid Waste, and Double Shell Slurry Feed. Process alternatives, unresolved issues, and development needs are discussed which relate to the process.

  15. Engineering study for the treatment of spent ion exchange resin resulting from nuclear process applications

    SciTech Connect

    Place, B.G.

    1990-09-01

    This document is an engineering study of spent ion exchange resin treatment processes with the purpose of identifying one or more suitable treatment technologies. Classifications of waste considered include all classes of low-level waste (LLW), mixed LLW, transuranic (TRU) waste, and mixed TRU waste. A total of 29 process alternatives have been evaluated. Evaluation parameters have included economic parameters (both total life-cycle costs and capital costs), demonstrated operability, environmental permitting, operational availability, waste volume reduction, programmatic consistency, and multiple utilization. The results of this study suggest that there are a number of alternative process configurations that are suitable for the treatment of spent ion exchange resin. The determinative evaluation parameters were economic variables (total life-cycle cost or capital cost) and waste volume reduction. Immobilization processes are generally poor in volume reduction. Thermal volume reduction processes tend to have high capital costs. There are immobilization processes and thermal volume reduction processes that can treat all classifications of spent ion exchange resin likely to be encountered. 40 refs., 19 figs., 17 tabs.

  16. Solidification of microbiologically treated ion-exchange resins using Portland cement-based systems

    SciTech Connect

    Voima Oy, I.

    1993-12-31

    Pretreated inactive ion exchange resins from the Loviisa nuclear power plant (NPP) were first reduced to one tenth of the original volume through microbiological treatment. During the process, the granular ion exchange resins were decomposed to result in dregs, which were solidified with two types of Portland cements. The objective of the present experiments was to investigate whether commercial cements are suitable solidification agents for this kind of waste. A total of ten mixtures were pretested for their rheological and setting properties. On the basis of the pretest results, four additional mixtures were chosen and tested for the spread value, density, air content, setting time and bleeding of the fresh waste product and for the dimensional stability and compressive strength of the hardened waste product. The cementing systems incorporated in the tests were ASTM type V Portland cement and ASTm type P Portland Composite cements. The dregs used in the tests were taken from a Pilot-Plant experiment at the Loviisa NPP and contained 2 wt-% solids. The test results were promising in showing that microbiological dregs can very easily be soldified with Portland cements to form a high-quality waste product. Thus, the microbiological treatment of spent ion exchange resins will drastically decrease the amount of solidified waste to be disposed of at the Loviisa NPP.

  17. THERMAL MODELING OF ION EXCHANGE COLUMNS WITH SPHERICAL RF RESIN

    SciTech Connect

    Lee, S.; King, W.

    2009-12-30

    Models have been developed to simulate the thermal performance of RF columns fully loaded with radioactive cesium. Temperature distributions and maximum temperatures across the column were calculated during Small Column Ion Exchange (SCIX) process upset conditions with a focus on implementation at Hanford. A two-dimensional computational modeling approach was taken to include conservative, bounding estimates for key parameters such that the results will provide the maximum centerline temperatures achievable under the design configurations using a feed composition known to promote high cesium loading on RF. The current full-scale design for the SCIX system includes a central cooling tube, and one objective of these calculations was to examine its elimination to simplify the design. Results confirmed that a column design without a central cooling tube is feasible for RF, allowing for the possibility of significant design simplifications if it can be assumed that the columns are always filled with liquid. With active cooling through the four outer tubes, the maximum column diameter expected to maintain the temperature below the assumed media and safety limits is 26 inches, which is comparable to the current design diameter. Additional analysis was conducted to predict the maximum column temperatures for the previously unevaluated accident scenario involving inadvertent drainage of liquid from a cesium-saturated column, with retention of the ion exchange media and cesium in the column. As expected, much higher maximum temperatures are observed in this case due to the poor heat transfer properties of air versus liquid. For this hypothetical accident scenario involving inadvertent and complete drainage of liquid from a cesium-saturated column, the modeling results indicate that the maximum temperature within a 28 inch diameter RF column with external cooling is expected to exceed 250 C within 2 days, while the maximum temperature of a 12 inch column is maintained below

  18. The Exchangeability of Amino Acids in Proteins

    PubMed Central

    Yampolsky, Lev Y.; Stoltzfus, Arlin

    2005-01-01

    The comparative analysis of protein sequences depends crucially on measures of amino acid similarity or distance. Many such measures exist, yet it is not known how well these measures reflect the operational exchangeability of amino acids in proteins, since most are derived by methods that confound a variety of effects, including effects of mutation. In pursuit of a pure measure of exchangeability, we present (1) a compilation of data on the effects of 9671 amino acid exchanges engineered and assayed in a set of 12 proteins; (2) a statistical procedure to combine results from diverse assays of exchange effects; (3) a matrix of “experimental exchangeability” values EXij derived from applying this procedure to the compiled data; and (4) a set of three tests designed to evaluate the power of an exchangeability measure to (i) predict the effects of amino acid exchanges in the laboratory, (ii) account for the disease-causing potential of missense mutations in the human population, and (iii) model the probability of fixation of missense mutations in evolution. EX not only captures useful information on exchangeability while remaining free of other effects, but also outperforms all measures tested except for the best-performing alignment scoring matrix, which is comparable in performance. PMID:15944362

  19. Simultaneous removal of dissolved organic matter and bromide from drinking water source by anion exchange resins for controlling disinfection by-products.

    PubMed

    Phetrak, Athit; Lohwacharin, Jenyuk; Sakai, Hiroshi; Murakami, Michio; Oguma, Kumiko; Takizawa, Satoshi

    2014-06-01

    Anion exchange resins (AERs) with different properties were evaluated for their ability to remove dissolved organic matter (DOM) and bromide, and to reduce disinfection by-product (DBP) formation potentials of water collected from a eutrophic surface water source in Japan. DOM and bromide were simultaneously removed by all selected AERs in batch adsorption experiments. A polyacrylic magnetic ion exchange resin (MIEX®) showed faster dissolved organic carbon (DOC) removal than other AERs because it had the smallest resin bead size. Aromatic DOM fractions with molecular weight larger than 1600 Da and fluorescent organic fractions of fulvic acid- and humic acid-like compounds were efficiently removed by all AERs. Polystyrene AERs were more effective in bromide removal than polyacrylic AERs. This result implied that the properties of AERs, i.e. material and resin size, influenced not only DOM removal but also bromide removal efficiency. MIEX® showed significant chlorinated DBP removal because it had the highest DOC removal within 30 min, whereas polystyrene AERs efficiently removed brominated DBPs, especially brominated trihalomethane species. The results suggested that, depending on source water DOM and bromide concentration, selecting a suitable AER is a key factor in effective control of chlorinated and brominated DBPs in drinking water. PMID:25079839

  20. New Anion-Exchange Resins for Improved Separations of Nuclear Materials

    SciTech Connect

    Bartsch, Richard A.; Barr, Mary E.

    2001-04-30

    Improved separations of nuclear materials will have a significant impact upon a broad range of DOE activities. DOE-EM Focus Areas and Crosscutting Programs have identified improved methods for the extraction and recovery of radioactive metal ions from process, waste, and environmental waters as critical needs for the coming years. We propose to develop multifunctional anion-exchange resins that facilitate anion uptake by carefully controlling the structure of the anion receptor site. Our new ion-exchange resins interface the field of ion-specific chelating ligands with robust, commercial ion-exchange technology to provide materials which exhibit superior selectivity and kinetics of sorption and desorption. The following Focus Areas and Crosscutting Programs have described needs that would be favorably impacted by the new material: Efficient Separations and Processing - radionuclide removal from aqueous phases; Plutonium - Pu, Am or total alpha removal to meet regulatory requirement s before discharge to the environment; Plumes - U and Tc in groundwater, U, Pu, Am, and Tc in soils; Mixed Waste - radionuclide partitioning; High-Level Tank Waste - actinide and Tc removal from supernatants and/or sludges. The basic scientific issues which need to be addressed are actinide complex speciation along with modeling of metal complex/functional site interactions in order to determine optimal binding-site characteristics. Synthesis of multifunctionalized extractants and ion-exchange materials that implement key features of the optimized binding site, and testing of these materials, will provide feedback to the modeling and design activities. Resin materials which actively facilitate the uptake of actinide complexes from solution should display both improved selectivity and kinetic properties. The long-range implications of this research, however, go far beyond the nuclear complex. This new methodology of ''facilitated uptake'' could revolutionize ion-exchange technology

  1. Protection of live bacteria from bile acid toxicity using bile acid adsorbing resins.

    PubMed

    Edwards, Alexander D; Slater, Nigel K H

    2009-06-12

    We previously demonstrated that a dry, room temperature stable formulation of a live bacterial vaccine was highly susceptible to bile, and suggested that this will lead to significant loss of viability of any live bacterial formulation released into the intestine using an enteric coating or capsule. We found that bile and acid tolerance is very rapidly recovered after rehydration with buffer or water, raising the possibility that rehydration in the absence of bile prior to release into the intestine might solve the problem of bile toxicity to dried cells. We describe here a novel formulation that combines extensively studied bile acid adsorbent resins with the dried bacteria, to temporarily adsorb bile acids and allow rehydration and recovery of bile resistance of bacteria in the intestine before release. Tablets containing the bile acid adsorbent cholestyramine release 250-fold more live bacteria when dissolved in a bile solution, compared to control tablets without cholestyramine or with a control resin that does not bind bile acids. We propose that a simple enteric coated oral dosage form containing bile acid adsorbent resins will allow improved live bacterial delivery to the intestine via the oral route, a major step towards room temperature stable, easily administered and distributed vaccine pills and other bacterial therapeutics. PMID:19490986

  2. Determination of boron concentration in oilfield water with a microfluidic ion exchange resin instrument.

    PubMed

    Floquet, Cedric F A; Sieben, Vincent J; MacKay, Bruce A; Mostowfi, Farshid

    2016-07-01

    We developed and validated a microfluidic instrument for interference-free determination of boron in produced water. The instrument uses a boron-specific chelating resin to separate the analyte from its complex matrix. Ten produced water samples were analyzed with the instrument and the results were successfully validated against ICP-MS measurements. Removing interference effects enables precise boron measurement for wastewater even with high total dissolved solid (TDS) levels. 1,4-Piperazinediethanesulfonic acid conditions the resin and maintains the optimum pH for boron adsorption from the sample. Boron is then eluted from the resin using a 10% sulfuric acid solution and its concentration measured with the colorimetric carminic acid assay in 95% sulfuric acid. The use of a microfluidic mixer greatly enhances the sensitivity and kinetics of the carminic acid assay, by factors of 2 and 7.5, respectively, when compared against the same assay performed manually. A maximum sensitivity of 2.5mg(-1)L, a precision of 4.2% over the 0-40.0mgL(-1) measuring range, a 0.3mgL(-1) limit of detection, and a sampling rate of up to four samples per hour were achieved. Automation and microfluidics reduce the operator workload and fluid manipulation errors, translating into safer and higher-quality measurements in the field. PMID:27154679

  3. 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.

  4. Understanding and modeling removal of anionic organic contaminants (AOCs) by anion exchange resins.

    PubMed

    Zhang, Huichun; Shields, Anthony J; Jadbabaei, Nastaran; Nelson, Maurice; Pan, Bingjun; Suri, Rominder P S

    2014-07-01

    Ionic organic contaminants (OCs) are a growing concern for water treatment and the environment and are removed inefficiently by many existing technologies. This study examined removal of anionic OCs by anion exchange resins (AXRs) as a promising alternative. Results indicate that two polystyrene AXRs (IRA910 and IRA96) have higher sorption capacities and selectivity than a polyacrylate resin (A860). For the polystyrene resins, selectivity follows: phenolates ≥ aromatic dicarboxylates > aromatic monocarboxylates > benzenesulfonate > aliphatic carboxylates. This trend can be explained based on hydration energy, the number of exchange groups, and aromaticity and hydrophobicity of the nonpolar moiety (NPM) of the anions. For A860, selectivity only varies within a narrow range (0.13-1.64). Despite the importance of the NPM of the anions, neutral solutes were sorbed much less, indicating synergistic combinations of electrostatic and nonelectrostatic interactions in the overall sorption. By conducting multiple linear regression between Abraham's descriptors and nature log of selectivity, induced dipole-related interactions and electrostatic interactions were found to be the most important interaction forces for sorption of the anions, while solute H-bond basicity has a negative effect. A predictive model was then developed for carboxylates and phenolates based on the poly parameter linear free energy relationships established for a diverse range of 16 anions and 5 neutral solutes, and was validated by accurate prediction of sorption of five test solutes within a wide range of equilibrium concentrations and that of benzoate at different pH. PMID:24877792

  5. A combined process of activated carbon adsorption, ion exchange resin treatment and membrane concentration for recovery of dissolved organics in pre-hydrolysis liquor of the kraft-based dissolving pulp production process.

    PubMed

    Shen, Jing; Kaur, Ishneet; Baktash, Mir Mojtaba; He, Zhibin; Ni, Yonghao

    2013-01-01

    To recover dissolved organics in pre-hydrolysis liquor (PHL) of the kraft-based dissolving pulp production process, a new combined process concept of sequential steps of activated carbon adsorption, ion exchange resin treatment, and membrane concentration, was proposed. The removal of lignin in the PHL was achieved in the activated carbon adsorption step, which also facilitates the subsequent operations, such as the membrane filtration and ion exchange resin treatment. The ion exchange resin treatment resulted in the removal/concentration of acetic acid, which opens the door for acetic acid recovery. The membrane filtration is to recover/concentrate the dissolved sugars. The combined process resulted in the production of PHL-based concentrate with relatively high concentration of hemicellulosic sugars, i.e., 22.13%. PMID:23131623

  6. Vitrification of ion-exchange (IEX) resins: Advantages and technical challenges

    SciTech Connect

    Jantzen, C.M.; Peeler, D.K.; Cicero, C.A.

    1995-12-31

    Technologies are being developed by the US Department of Energy`s (DOE) Savannah River Site (SRS) in conjunction with the Electric Power Research Institute (EPRI) and the commercial sector to convert low-level radioactive ion exchange (IEX) resin wastes from the nuclear utilities to solid stabilized waste forms for permanent disposal. One of the alternative waste stabilization technologies is vitrification of the resin into glass. Wastes can be vitrified at elevated temperatures by thermal treatment. One alternative thermal treatment is conventional Joule heated melting. Vitrification of wastes into glass is an attractive option because it atomistically bonds both hazardous and radioactive species in the glass structure, and volume reduces the wastes by 70-80%. The large volume reductions allow for large associated savings in disposal and/or long term storage costs.

  7. Performance of selected anion exchange resins for the treatment of a high DOC content surface water.

    PubMed

    Humbert, Hugues; Gallard, Hervé; Suty, Hervé; Croué, Jean-Philippe

    2005-05-01

    The objective of this study was first to compare the performance of four strong anion exchange resins (AERs) (MIEX from Orica Pty Ltd, DOWEX-11 and DOWEX-MSA from DOW chemical and IRA-938 from Rohm and Haas) for their application in drinking water treatment (natural organic matter (NOM), mineral anions (nitrate, sulfate and bromide) and pesticide removal) using bench-scale experimental procedures on a high DOC content surface water. The efficiency of MIEX for NOM and mineral anions removal was furthermore evaluated using bench-scale dose-response experiments on raw, clarified and post-ozonated waters. NOM removal was assessed using the measurement of dissolved organic carbon (DOC), UV absorbance at 254 nm (UV254) and the use of high-performance size exclusion chromatography with UV (HPSEC/UV) and fluorescence detection (HPSEC/FLUO). The MIEX and IRA938 anionic resins exhibit a faster removal of NOM and mineral anions compared to the DOWEX11 and MSA AERs. All the resins were found to be very effective with similar performances after 30 to 45 min of contact time. As expected, only limited sorption of atrazine and isoproturon (C0=1 microg/L) occurred with MIEX, DOWEX11 and MSA AERs. MIEX resin proved to be very efficient in eliminating NOM of high-molecular weight but also a large part of the smallest UV absorbing organic compounds which were refractory to coagulation/flocculation treatment. Remaining DOC levels after 30 min of contact with MIEX were found similar in raw water, clarified water and even post-ozonated water implying no DOC benefit can be gained by employing conventional treatment prior to MIEX treatment. Removal of bromide (initial concentration 110 microg/L) was also observed and ranged from 30% to 65% for resin dose increasing from 2 to 8 mL/L. T PMID:15899268

  8. Kafirin adsorption on ion-exchange resins: isotherm and kinetic studies.

    PubMed

    Kumar, Prashant; Lau, Pei Wen; Kale, Sandeep; Johnson, Stuart; Pareek, Vishnu; Utikar, Ranjeet; Lali, Arvind

    2014-08-22

    Kafirin is a natural, hydrophobic and celiac safe prolamin protein obtained from sorghum seeds. Today kafirin is found to be useful in designing delayed delivery systems and coatings of pharmaceuticals and nutraceuticals where its purity is important and this can be obtained by adsorptive chromatography. This study is the first scientific insight into the isotherm and kinetic studies of kafirin adsorption on anion- and cation-exchange resins for practical applications in preparative scale chromatography. Adsorption isotherms of kafirin were determined for five anion- and two cation-exchange resins in batch systems. Isotherm parameters such as maximum binding capacity and dissociation constant were determined from Langmuir isotherm, and adsorptive capacity and affinity constant from Freundlich isotherm. Langmuir isotherm was found to fit the adsorption equilibrium data well. Batch uptake kinetics for kafirin adsorption on these resins was also carried out and critical parameters including the diffusion coefficient, film mass transfer coefficient, and Biot number for film-pore diffusion model were calculated. Both the isotherm and the kinetic parameters were considered for selection of appropriate resin for kafirin purification. UNOsphere Q (78.26 mg/ml) and Toyopearl SP-650M (57.4 mg/ml) were found to offer better kafirin binding capacities and interaction strength with excellent uptake kinetics under moderate operating conditions. With these adsorbents, film diffusion resistance was found to be major governing factor for adsorption (Bi<10 and δ<1). Based on designer objective function, UNOsphere Q was found be best adsorbent for binding of kafirin. The data presented is valuable for designing large scale preparative adsorptive chromatographic kafirin purification systems. PMID:25022481

  9. Analysis of trihalomethane precursor removal from sub-tropical reservoir waters by a magnetic ion exchange resin using a combined method of chloride concentration variation and surrogate organic molecules.

    PubMed

    Phetrak, Athit; Lohwacharin, Jenyuk; Takizawa, Satoshi

    2016-01-01

    In small reservoirs in tropical islands in Japan, the disinfection by-product formation potential is high due to elevated concentrations of dissolved organic matter (DOM) and bromide. We employed a combined method of variation of chloride concentrations and the use of DOM surrogates to investigate removal mechanisms of bromide and different fractions of DOM by chloride-based magnetic ion exchange (MIEX®) resin. The DOM in reservoir waters was fractionated by resins based on their hydrophobicity, and characterized by size-exclusion chromatography and fluorescence excitation-emission matrix spectrophotometry. The hydrophobic acid (HPO acid) fraction was found to be the largest contributor of the trihalomethane (THM) precursors, while hydrophilic acid (HPI acid) was the most reactive precursors of all the four THM species. Bromide and DOM with a molecular weight (MW) greater than 1kDa, representing HPO acid (MW 1-3kDa) and HPI acid (MW 1-2kDa), were effectively removed by MIEX® resin; however, DOM with a MW lower than 1kDa, representing HPI non-acid, was only moderately removed. The removal of THM precursors by MIEX® resin was interfered by high chloride concentrations, which was similar to the removal of glutamic acid (HPI acid surrogate) and bromide. However, elevated chloride concentrations had only a minor effect on tannic acid (HPO acid surrogate) removal, indicating that HPO acid fraction was removed by a combination of ion exchange and physical adsorption on MIEX® resin. Our study demonstrated that the combined use of DOM surrogates and elevated chloride concentrations is an effective method to estimate the removal mechanisms of various DOM fractions by MIEX® resin. PMID:26360458

  10. Advanced treatment of textile dyeing secondary effluent using magnetic anion exchange resin and its effect on organic fouling in subsequent RO membrane.

    PubMed

    Yang, Cheng; Li, Li; Shi, Jialu; Long, Chao; Li, Aimin

    2015-03-01

    Strict regulations are forcing dyeing factory to upgrade existing waste treatment system. In this study, advanced treatment of dyeing secondary effluent by magnetic anion exchange resin (NDMP) was investigated and compared with ultrafiltration (UF); NDMP as a pre-treatment of reverse osmosis (RO) was also studied. NDMP resin (20 mL/L) gave higher removal of dissolved organic carbon (DOC) (83.9%) and colority (94.9%) than UF with a cut-off of 10 kDa (only 48.6% and 44.1%, respectively), showing that NDMP treatment was effective to meet the stringent discharge limit of DOC and colority. Besides, NDMP resin (20 mL/L) as a pretreatment of RO increased the permeate flux by 12.5% and reduced irreversible membrane fouling by 6.6%, but UF pretreatment did not mitigate RO membrane fouling. The results of excitation-emission matrix fluorescence spectra and resin fractions showed that NDMP had more efficient removal than UF for transphilic acid and hydrophilic fraction, such as protein-like organic matters and soluble microbial products, which contributed to a significant proportion of RO membrane fouling. In sum, NDMP resin treatment not only gave effective removal of DOC and colority of dyeing secondary effluent, but exhibited some improvement for RO membrane flux and irreversible fouling. PMID:25463217

  11. Cation exchange resin nanocomposites based on multi-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Fathy, Mahmoud; Abdel Moghny, Th.; Awad Allah, Ahmed Elsayed; Alblehy, AbdElhamid

    2014-01-01

    Carbon nanotubes (CNTs) are of great interest due to their potential applications in different fields such as water treatment and desalination. The increasing exploitation of multi-walled carbon nanotubes (MWCNTs) into many industrial processes has raised considerable concerns for environmental applications. The interactions of soluble salt with MWNCTs influence in the total salt content in saline water. In this work, we synthesized two cation exchange resins nano composites from polystyrene divinylbenzene copolymer (PSDVB) and pristine MWNCTs. The prepared compounds were characterized using infra red spectroscopy, thermal stability, X-ray diffraction, and electro scan microscope. Also, the ion capacities of prepared cation exchange resins were determined by titration. Based on the experimental results, it was found that the thermal stability of prepared nanocomposites in the presence of MWNCTs increased up to 617 °C. The X-ray of PSDVB and its sulfonated form exhibits amorphous pattern texture structure, whereas the nano composite exhibits amorphous structure with indication peak at 20° and 26° for the PSDVB and MWCNTs, respectively. The ion-exchange capacity increased from 225.6 meq/100 g to 466 mg/100 g for sulfonated PSDVB and sulfonated PSDVB MWNCTs-pristine, respectively.

  12. The oxidative degradation of polystyrene resins on the removal of Cr(VI) from wastewater by anion exchange.

    PubMed

    Xiao, Ke; Xu, Fuyuan; Jiang, Linhua; Dan, Zhigang; Duan, Ning

    2016-08-01

    Cr(VI) is a powerful oxidant and is capable of oxidizing most of the organic materials. Therefore, it is possible for Cr(VI) to oxidize the polymeric resins and change the sorption properties of the resins on the removal of Cr(VI) from wastewater by anion exchange. In this study, three polystyrene resins (D201, D202, and D301) with different functional groups (-N(+)(CH3)3, -N(+)(CH3)2(C2H4OH), and N(CH3)2) were assessed on oxidation stability for Cr(VI) removal from wastewater in fixed-bed column experiments. After a 10-cycle operation, due to the oxidation of the resin, the sorption capacity of D201, D202, and D301 resins decreased by 23.5, 29.3, and 17.3%, when approximately 20-34%, 31-50%, and 18-30% of Cr(VI) was reduced to Cr(III) during each cycle respectively. The results of the Fourier transform infrared spectroscopy (FT-IR) showed that both the cleavage of CN and the formation of CO bonds occurred on the polystyrene resins during the Cr(VI) removal process. The resin simulation experiments further validated the oxidation of CC and CN bonds connected with phenethyl groups. Based upon the results from column operations and the resin simulated experiments, the oxidation mechanism of the polystyrene resin was proposed. PMID:27183334

  13. Dissolved organic matter removal using magnetic anion exchange resin treatment on biological effluent of textile dyeing wastewater.

    PubMed

    Fan, Jun; Li, Haibo; Shuang, Chendong; Li, Wentao; Li, Aimin

    2014-08-01

    This study investigated the removal of dissolved organic matter (DOM) from real dyeing bio-treatment effluents (DBEs) with the use of a novel magnetic anion exchange resin (NDMP). DOMs in two typical DBEs were fractionized using DAX-8/XAD-4 resin and ultrafiltration membranes. The hydrophilic fractions and the low molecular weight (MW) (<3kDa) DOM fractions constituted a major portion (>50%) of DOMs for the two effluents. The hydrophilic and low MW fractions of both effluents were the greatest contributors of specific UV254 absorbance (SUVA254), and the SUVA254 of DOM fractions decreased with hydrophobicity and MW. Two DBEs exhibited acute and chronic biotoxicities. Both acute and chronic toxicities of DOM fractions increased linearly with the increase of SUVA254 value. Kinetics of dissolved organic carbon (DOC) removal via NDMP treatment was performed by comparing it with that of particle active carbon (PAC). Results indicated that the removal of DOC from DBEs via NDMP was 60%, whereas DOC removals by PAC were lower than 15%. Acidic organics could be significantly removed with the use of NDMP. DOM with large MW in DBE could be removed significantly by using the same means. Removal efficiency of NDMP for DOM decreased with the decrease of MW. Compared with PAC, NDMP could significantly reduce the acute and chronic bio-toxicities of DBEs. NaCl/NaOH mixture regenerants, with selected concentrations of 10% NaCl (m/m)/1% NaOH (m/m), could improve desorption efficiency. PMID:25108712

  14. Preliminary Ion Exchange Modeling for Removal of Cesium from Hanford Waste Using SuperLig 644 Resin

    SciTech Connect

    Hamm, L.L.

    2000-08-23

    A proposed facility is being designed for the immobilization of Hanford high-level radioactive waste. One unit process in the facility is designed to remove radioactive cesium by ion-exchange from the strongly alkaline aqueous phase. A resin specifically designed with high selectivity of cesium under alkaline conditions is being investigated. The resin also is elutable under more acidic conditions. The proposed design of the facility consists of two sets of two packed columns placed in series (i.e., a lead column followed by a lag (guard) column configuration). During operation, upon reaching a specified cesium concentration criterion at the exit of the lag column, operation is switched to the second set of lead and lag columns. The cesium-loaded lead column is processed (i.e., washed and eluted) and switched to the lag position. the previous lag column is then placed in the lead position (without eluting) and the system is ready for use in the next cycle. For a well designed process, the loading and elution processes result in significant volume reductions in aqueous high-level waste.

  15. In vitro adsorption removal of paraquat by activated carbon and cation exchange resin

    SciTech Connect

    Kitakouji, M.; Miyoshi, T.; Tanada, M.S.; Nakamura, T. )

    1989-06-01

    With the modernization of agriculture, environmental pollution and accidental poisoning by agricultural chemicals have become a great social problem. With the remarkable increase in the amount of paraquat used, the number of deaths by swallowing of paraquat has also increased in recent years. Presently, an effective antidote and treatment for paraquat poisoning is not available. For primary treatment, administration of an adsorbent is done at the same time as gastrointestinal lavage. As an adsorbent for paraquat poisoning, the efficacy of activated carbon, Fuller's Earth, bentonite, and a cation exchange resin have been reported. In this work, the authors discuss the adsorption characteristics of paraquat in artificial gastric juice and normal saline solution.

  16. Formulation Study on Immobilization of Spent Ion Exchange Resins in Polymer Cements

    SciTech Connect

    Lili Xia; Meiqiong Lin; Bao Liangjin

    2006-07-01

    Applying normal design and correlative computer software, a new matrix material and an excellent waste formulation were developed. Based on the theory calculations and normal design in this paper, using polymer complex cement as immobilization matrix that mixed with simulating spent ion exchange resin a new waste formulation was carried out. The characterization of solidified waste had been done after 28 days curing. The results conformed to the treatment of the waste about the requests of the national standard [GB14569-93-1]. Leach index of the solidified waste was excellent. An optimized formulation was recommended. (authors)

  17. Radiation curing of polyester resin modified with acrylic acid and its salts

    NASA Astrophysics Data System (ADS)

    Szalińska, H.; Pietrzak, M.; Janowska, G.

    Polyester resin containing acrylic acid or its salts was cured with γ 60Co radiation. The course of curing was examined, the gel content and polymerization shrinkage were measured and also thermographic and IR absorption analyses were carried out. It was found that manganese, iron and copper acrylates inhibited the curing of resin while the remaining additives showed a slightly stimulating action. All the additives decreased the polymerization shrinkage by a factor of 2-3 and iron acrylate by as much as 8 times (up to 1%). They also increased the activation energy of the thermal decomposition of resin, and calcium, barium and copper acrylates increased the thermal stability of resin by 20 K. IR absorption spectra showed that acrylic acid and its salts reacted mainly with the monomeric component of the resin (styrene) whereas iron and copper acrylates first attacked the unsaturated bonds of the oligoester.

  18. Microbiology and biodegradation of resin acids in pulp mill effluents: a minireview.

    PubMed

    Liss, S N; Bicho, P A; Saddler, J N

    1997-07-01

    Resin acids, a group of diterpenoid carboxylic acids present mainly in softwood species, are present in many pulp mill effluents and toxic to fish in recipient waters. They are considered to be readily biodegradable. However, their removal across biological treatment systems has been shown to vary. Recent studies indicate that natural resin acids and transformation products may accumulate in sediments and pose acute and chronic toxicity to fish. Several resin acid biotransformation compounds have also been shown to bioaccumulate and to be more resistant to biodegradation than the original material. Until recently, the microbiology of resin-acid degradation has received only scant attention. Although wood-inhabiting fungi have been shown to decrease the level of resin present in wood, there is no conclusive evidence that fungi can completely degrade these compounds. In contrast, a number of bacterial isolates have recently been described which are able to utilize dehydroabietic or isopimaric acids as their sole carbon source. There appears to be an unusually high degree of substrate specificity with respect of the utilization of abietane congeners and the presence of substituents. Pimaranes do not appear to be attacked to the same extent as the abietanes. This paper reviews the occurrence, chemistry, toxicity, and biodegradation of resin acids in relation to the biological treatment of pulp and paper mill effluents. PMID:9246738

  19. 2-Chlorotrityl chloride resin. Studies on anchoring of Fmoc-amino acids and peptide cleavage.

    PubMed

    Barlos, K; Chatzi, O; Gatos, D; Stavropoulos, G

    1991-06-01

    The esterification of 2-chlorotrityl chloride resin with Fmoc-amino acids in the presence of DIEA is studied under various conditions. High esterification yields are obtained using 0.6 equiv. Fmoc-amino acid/mmol resin in DCM or DCE, in 25 min, at room temperature. The reaction proceeds without by product formation even in the case of Fmoc-Asn and Fmoc-Gln. The quantitative and easy cleavage of amino acids and peptides from 2-chlorotrityl resin, by using AcOH/TFE/DCM mixtures, is accomplished within 15-60 min at room temperature, while t-butyl type protecting groups remain unaffected. Under these exceptionally mild conditions 2-chlorotrityl cations generated during the cleavage of amino acids and peptides from resin do not attack the nucleophilic side chains of Trp, Met, and Tyr. PMID:1917309

  20. Vinyl polymer agglomerate based transition metal cation chelating ion-exchange resin containing the 8-hydroxyquinoline functional group

    SciTech Connect

    Landing, W.M.; Haraldsson, C.; Paxeus, N.

    1986-12-01

    A simple synthetic route has been developed for the immobilization of 8-hydroxyquinoline onto Fractogel TSK, a highly porous, mechanically and chemically stable, hydrophilic organic resin gel. The product exhibits an exchange capacity comparable to the highest values reported for silica-immobilized 8-hydroxyquinoline but is more stable at high pH. The resin's selectivity and efficiency of collection of cationic metal species from freshwater and seawater were investigated. The resin was used in a column sequence to obtain concentration and speciation data for Al, Mn, Fe, Co, Cu, Zn, and Cd in an organic-rich freshwater sample.

  1. Radiolysis of the AV-17×8 ČS anion-exchange resin

    NASA Astrophysics Data System (ADS)

    Bartoníček, B.; Habersbergerová, A.; Janovský, I.; Kysela, J.; Pejša, R.

    The mixture of the anion exchange resin AV-17×8 čs in borate form and of a deaerated aqueous solution containing H 3BO 3 and NH 3 ( pH = 7) was irradiated with gamma rays in both static and dynamic conditions. A loss of strong-base exchange capacity and an increase of weak-base capacity was observed. In the solution, (CH 3) 3N, (CH 3) 2NH and CH 3NH 2 were found as the radiolytic products, their relative ratio being 15.7 : 3.7 : 1. Further, NH 3 is formed with the concentration of the same order as that of CH 3NH 2. Beside hydrogen, which is the prevailing gaseous product of the radiolysis of the mixture, methane and ethane arise, their ratio in the dynamic irradiation being 2.8 to 6.0. The main features of the radiolysis are outlined.

  2. 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.

  3. The effects of anion exchange functional-group variations on the sorption of Pu(IV) from nitric acid

    SciTech Connect

    Marsh, S.F.

    1995-12-01

    A macroporous, polyvinylpyridine anion exchange resin has been used for more than five years at the Los Alamos Plutonium Facility to recover plutonium from nitrate media. This strong-base anion exchanger, Reillex{trademark} HPQ, offers higher capacity, faster kinetics, and significantly higher resistance to chemical and radiation damage than conventional polystyrene-based resins. In this study, we measured the sorption of Pu(IV) on Reillex{trademark} HPQ and on three macroporous, strong-base anion exchange resins that differ from Reillex{trademark} HPQ only in the alkyl group used to quaternize the pyridinium. nitrogen. These four resins, prepared by Reilly Industries, Inc., are copolymers of 1-alkyl-4-vinylpyridine, where the alkyl groups are methyl, butyl, hexyl, and octyl. We compare the trends in Pu(IV) sorption on these four resins to those obtained in our previous study of four polystyrene anion exchange resins having trimethyl, triethyl, tripropyl, and tributyl ammonium functionality. The Pu(IV) sorption was measured from 1 M to 9 M nitric acid in both studies.

  4. Solid-Phase Synthesis with Attachment of Peptide to Resin through an Amino Acid Side Chain: [8-Lysine]-Vasopressin

    PubMed Central

    Meienhofer, Johannes; Trzeciak, Arnold

    1971-01-01

    It is proposed that the scope of solid-phase peptide synthesis could be considerably broadened by attaching peptides to the solid-phase through functional side-chain groups rather than through the commonly used α-carboxyl groups. Side-chain attachment offers the use of a large variety of chemical linkages to solid supports. Attachment through the ε-amino group of the lysine residue to a polystyrene resin has been applied to a solid-phase synthesis of lysine-vasopressin. Nα-tert-butyl-oxycarbonyl-L-lysyl-glycinamide was condensed with chloroformoxymethyl polystyrene-2% divinylbenzene resin. After removal of the Nα-protecting tert-butyloxycarbonyl group, the peptide chain was elongated by standard Merrifield procedures to give Tos-Cys(Bzl)-Tyr-Phe-Glu-(NH2) - Asp(NH2) - Cys(Bzl) - Pro - Lys(Z - resin) - Gly-NH2. Cleavage from the resin with HBr in dioxane or trifluoroacetic acid gave a partially protected nonapeptide hydrobromide. For purification, it was converted into a fully protected peptide by treatment with benzyl p-nitro-phenyl carbonate and crystallized. Deprotection by sodium in liquid ammonia, oxidative cyclization, IRC-50 desalting, and ion-exchange chromatography gave lysinevasopressin with high potency in a rat-pressor assay. PMID:5280519

  5. PRELIMINARY REPORT ON EVALUATION OF POTENTIAL ELUANTS FOR NON-ACID ELUTION OF CESIUM FROM RESORCINOL-FORMALDEHYDE RESIN

    SciTech Connect

    Adu-Wusu, K.; Pennebaker, F.

    2010-09-01

    Small-column ion exchange (SCIX) units installed in high-level waste tanks to remove Cs-137 from highly alkaline salt solutions are among the waste treatment plans in the DOE-complex. Spherical Resorcinol-Formaldehyde (sRF) is the ion exchange resin selected for use in the Hanford Waste Treatment and Immobilization Plant (WTP). It is also the primary ion exchange material under consideration for SCIX at the Hanford site. The elution step of the multi-step ion exchange process is typically done with 0.5 M nitric acid. An acid eluant is a potential hazard in the event of a spill, leak, etc. because the high-level waste tanks are made of carbon steel. Corrosion and associated structural damage may ensue. Studies are ongoing to explore non-acid elution as an alternative. Batch contact sorption equilibrium screening tests have been conducted with 36 potential non-acid eluants. The sorption tests involve equilibrating each cesium-containing eluant solution with the sRF resin for 48 hours at 25 C in a shaker oven. In the sorption tests, an eluant is deemed to have a high cesium elution potential if it minimizes cesium sorption onto the sRF resin. The top candidates (based on lowest cesium sorption distribution coefficients) include ammonium carbonate, ammonium carbonate/ammonium hydroxide, ammonium bicarbonate, rubidium carbonate, ammonium acetate, ammonium acetate/ammonium hydroxide, ammonium bicarbonate/ammonium hydroxide, calcium chloride, and magnesium chloride. The next phase of testing for this work will focus on the following down selected eluants: Ammonium carbonate, ammonium acetate, calcium acetate, magnesium acetate, nitric acid, and ammonium hydroxide. The next testing phase is a confirmation of the elution ability of the selected eluants. It will mimic a typical sRF cesium ion exchange process i.e., sorption or loading, caustic wash, water rinse, and elution via batch contact sorption and quasi column caustic wash/water rinse/elution. Due to corrosion

  6. Separation of salvianic acid A from the fermentation broth of engineered Escherichia coli using macroporous resins.

    PubMed

    Bai, Chen-Long; Zhao, Guang-Rong

    2015-08-01

    Salvianic acid A (also known as danshensu) is a plant-derived polyphenolic acid, and has a variety of physiological and pharmacological activities. Our laboratory previously constructed an unprecedented artificial biosynthetic pathway in Escherichia coli and established the fermentation process to produce salvianic acid A. Here, we developed an efficient method for separating salvianic acid A from the fermentation broth of engineered Escherichia coli by macroporous resins. Among ten tested macroporous resins, the static and dynamic adsorption/desorption experiments demonstrated that X5 resin was the best to separate salvianic acid A from fermentation broth. Other parameters during static and dynamic procedures were also investigated. Under the optimum separation conditions, the average adsorption capacity of SAA were 10.66±0.54 mg/g dry resin and the desorption ratio was 85.6±4.1%. The purity and recovery yield of salvianic acid A in the final dry product were 90.2±1.5 and 81.5±2.3%, respectively. The results show that adsorption separation with macroporous resin X5 was an efficient method to prepare salvianic acid A from fermentation broth. This work will benefit the development and application of plant-derived salvianic acid A and its derivatives. PMID:26097085

  7. REMOVAL OF CESIUM FROM SAVANNAH RIVER SITE WASTE WITH SPHERICAL RESORCINOL FORMALDEHYDE ION EXCHANGE RESIN EXPERIMENTAL TESTS

    SciTech Connect

    Duignan, M.; Nash, C.

    2010-03-31

    A principal goal at the Savannah River Site (SRS) is to safely dispose of the large volume of liquid nuclear waste held in many storage tanks. In-tank ion exchange (IX) columns are being considered for cesium removal. The spherical form of resorcinol formaldehyde ion exchange resin (sRF) is being evaluated for decontamination of dissolved saltcake waste at SRS, which is generally lower in potassium and organic components than Hanford waste. The sRF performance with SRS waste was evaluated in two phases: resin batch contacts and IX column testing with both simulated and actual dissolved salt waste. The tests, equipment, and results are discussed.

  8. Single vial sample preparation of markers of nerve agents by dispersive solid-phase extraction using magnetic strong anion exchange resins.

    PubMed

    Singh, Varoon; Chinthakindi, Sridhar; Purohit, Ajay Kumar; Pardasani, Deepak; Tak, Vijay; Dubey, Devendra Kumar

    2015-05-22

    A sample preparation method involving extraction, enrichment and derivatization of acidic degradation products of nerve agents was developed using magnetic strong anion exchange resins (MSAX). The method was performed in a single vial involving magnetic dispersive solid phase extraction (MDSPE). Analytes were derivatized with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) in the presence of resins. MSAX were custom synthesized using Fe3O4 nanoparticles as core, 4-vinylpyridine-co-divinylbenzene as polymer shell and quaternary pyridinium function as anion-exchanger. Hydroxide ions were the counter-anions of MSAX to effectively capture the acidic alkyl alkylphosphonic acids (AAPAs) and alkylphosphonic acids (APAs). Quantitative measurements of analytes were performed in the selected ion monitoring mode of GC-MS. Full scan mode of analysis was followed for identifications. Under the optimized conditions analytes were recovered in the range of 39.7-98.8% (n=3, relative standard deviations (RSD) from 0.3 to 6.5%). Limits of detection (LODs) were in the range of 0.1-1.1ngmL(-1); and the linear dynamic range was 5-1000ngmL(-1) with r(2) of 0.9977-0.9769. Applicability of the method was tested with rain-, tap-, muddy-water and Organization for Prohibition of Chemical Weapons (OPCW) Proficiency Test samples. PMID:25863924

  9. Optimizing liquid waste treatment processing in PWRs: focus on modeling of the variation of ion-exchange resins selectivity coefficients

    SciTech Connect

    Gressier, Frederic; Van der Lee, Jan; Schneider, Helene; Bachet, Martin; Catalette, Hubert

    2007-07-01

    A bibliographic survey has highlighted the essential role of selectivity on resin efficiency, especially the variation of selectivity coefficients in function of the resin saturation state and the operating conditions. This phenomenon has been experimentally confirmed but is not yet implemented into an ion-exchange model specific for resins. This paper reviews the state of the art in predicting sorption capacity of ion-exchange resins. Different models accounting for ions activities inside the resin phase are available. Moreover, a comparison between the values found in the literature and our results has been done. The results of sorption experiments of cobalt chloride on a strong cationic gel type resin used in French PWRs are presented. The graph describing the variation of selectivity coefficient with respect to cobalt equivalent fraction is drawn. The parameters determined by the analysis of this graph are injected in a new physico-chemical law. Implementation of this model in the chemical speciation simulation code CHESS enables to study the overall effect of this approach for the sorption in a batch. (authors)

  10. Salbutamol versus cation-exchange resin (kayexalate) for the treatment of nonoliguric hyperkalemia in preterm infants.

    PubMed

    Yaseen, Hakam; Khalaf, Mona; Dana, Ahmed; Yaseen, Noha; Darwich, Maha

    2008-03-01

    Our objective was to compare the efficacy and safety of rectal cation-exchange resin (Kayexalate) versus salbutamol infusion for the treatment of nonoliguric hyperkalemia (NOHK) in preterm infants. Data of all neonates born with NOHK during the study period of 6 years and 8 months were recorded. Diagnostic criteria of NOHK included serum potassium (SK) concentration > or = 7 mmol/L during the first 72 hours of life with urine output > or = 1 mL/kg/hour. This before-after study was divided according to the date of admission; the first 15 patients were treated with Kayexalate enema 1 g/kg every 4 hours, and the remaining 30 patients were treated with intravenous salbutamol infusion as 4 mug/kg every 4 hours. Treatment discontinued when SK became < 6 mmol/L. SK was measured every 4 hours. Daily urine was collected. Fluid intake and output, serum electrolytes, urea, creatinine, and glucose concentrations were obtained in all infants every 12 hours. All infants were observed with a cardiorespiratory monitor and oxygen saturation and blood pressure measurements. Perinatal characteristics in both groups were comparable. Mean gestational age was 26 and 28 weeks for salbutamol and Kayexalate, respectively. The peak of SK ranged between 7 and 9.3 mmol/L in the Kayexalate group and between 7 and 8.7 mmol/L in the salbutamol group ( P = 0.64). At 12 hours of treatment, SK became normal in only 4 patients (26%) in the Kayexalate group compared with 18 patients (60%) in the salbutamol group ( P = 0.003). The number of doses of Kayexalate administration was significantly higher than the doses of salbutamol ( P = 0.003). No significant side effects were detected in the salbutamol-treated infants. In contrast, there were two cases of severe ventricular tachycardia and one case of intestinal obstruction in the cation-exchange resin group. We concluded that salbutamol infusion is more effective with faster action and safer than cation-exchange resin (Kayexalate) for the treatment of

  11. Incorporation of multi-walled carbon nanotubes in microspheres used as anion exchange resin via suspension polymerization

    NASA Astrophysics Data System (ADS)

    Fathy, Mahmoud; Abdel Moghny, Th.; Awadallah, Ahmed E.; El-Bellihi, Abdel-Hameed A.-A.

    2014-06-01

    Amination of vinylbenzyl chloride-divinylbenzene (VBC-DVB) copolymers is an effective method for preparation of anion-exchange resins. Conventionally, the starting polymer is produced by chloromethylation of a styrene-divinylbenzene copolymer that utilizes chloromethyl methyl ether, a known carcinogen. An alterative approach is to copolymerize vinylbenzyl chloride with divinylbenzene to generate the necessary VBC-DVB. This method provides precise control over the density of the ion-exchange groups. The regiochemistry of the vinylbenzyl chloride methods was realized using solvent-ion exchange groups. These resulting anion-exchange polymers were characterized by a variety of techniques such as analytical titrations, transform infrared spectroscopy and thermal gravimetric analysis. Testing of these copolymers for breakthrough was performed. The results indicate that these anion exchangers have a meaningful increase in thermal stability over commercial anionic exchange beads. Resins containing MWCNTs achieved anion exchange capacity value of 323.6 meq/100 g over than that of copolymer resins and that useful in water desalination or treatment.

  12. Development and validation of a novel modeling framework integrating ion exchange and resin regeneration for water treatment.

    PubMed

    Zhang, Jie; Amini, Adib; O'Neal, Jeremy A; Boyer, Treavor H; Zhang, Qiong

    2015-11-01

    Models have been developed to simulate the process of ion exchange for water treatment. However the modeling of resin regeneration process, which can predict regeneration efficiency and residual stream for determining technology sustainability, was not incorporated into previous models. Therefore a model integrating both ion exchange and resin regeneration considering regeneration efficiency is needed for evaluating and improving ion exchange technology. This study developed an integrated model aiming to simulate ion exchange and resin regeneration in different configurations (fixed bed, fluidized bed) for the first time. The integrated model has been validated via comparing model predictions with experimental data. The impacts of dimensionless groups (i.e. the Péclet number, the diffusion modulus, and the Biot number) on ion exchange breakthrough curve have been analyzed using this model. In addition, this integrated model has been used to optimize the regeneration frequency to improve the overall performance of ion exchange. It demonstrated this integrated model could be a useful tool for further studies in ion exchange technology. PMID:26253896

  13. Fully automated synthesis of O-(3-[18F]fluoropropyl)-L-tyrosine by direct nucleophilic exchange on a quaternary 4-aminopyridinium resin.

    PubMed

    Tang, Ganghua; Tang, Xiaolan; Wang, Mingfang; Luo, Lei; Gan, Manquan

    2003-06-01

    A fully automated synthesis of O-(3-[18F]fluoropropyl)-L-tyrosine (FPT), an amino acid tracer for tumor imaging with positron emission tomography, is described. FPT was prepared by a two-step reaction sequence. Direct nucleophilic fluorination substitution of [18F]fluoride with 1,3-di(4-methylphenylsulfonyloxy)propane on a quaternary 4-(4-methylpiperidinyl)pyridinium functionalized polystyrene anion exchange resin, followed by [18F]fluoro-1-(4-methylphenylsulfonyloxy)propane yielded FPT. The overall radiochemical yield with no decay correction was about 12%; the whole synthesis time was about 52 min, and the radiochemical purity was above 95%. PMID:12798378

  14. Effects of experimental conditions on extraction yield of extracellular polymeric substances by cation exchange resin.

    PubMed

    Cho, Jinwoo; Hermanowicz, Slawomir W; Hur, Jin

    2012-01-01

    Effects of experimental conditions on the yield of extracellular polymeric substances (EPSs) extraction by cation exchange resin (CER) were investigated using activated sludge flocs. The experimental variables included resin dose, extraction time, sample dilution, and storage time. An empirical model was proposed to describe the kinetics of extraction process. The extraction yield increases with the extraction time and CER dose until it reached the maximum amount of EPS extraction. The maximum yield of EPS was affected as well by the sample dilution, exhibiting a decreasing trend with increasing dilution factor. It was also found that the amount of EPS extracted from a raw sample depends on the storage time. Once EPS was extracted from the sample, however, the EPS keeps its original quantity under storage at 4°C. Based on the model, the maximum amount of EPS extraction and yield rate could be estimated for different conditions. Comparing the model parameters allows one to quantitatively compare the extraction efficiencies under various extracting conditions. Based on the results, we recommend the original sample should be diluted with the volume ratio of above 1:2 and a raw sample should be treated quickly to prevent the reduction of sample homogeneity and original integrity. PMID:22919352

  15. Effect of pH on the release of radionuclides and chelating agents from cement-solidified decontamination ion-exchange resins collected from operating nuclear power stations

    SciTech Connect

    McIsaac, C.V.; Akers, D.W.; McConnell, J.W. )

    1991-06-01

    Data are presented on the physical stability and leachability of radionuclides and chelating agents from cement-solidified decontamination ion-exchange resin wastes collected from two operating commercial light water reactors. Small-scale waste--form specimens collected during solidifications performed at the Brunswick Steam Electric Plant Unit 1 and at the James A. FitzPatrick Nuclear Power Station were leach-tested and subjected to compressive strength testing in accordance with the Nuclear Regulatory Commission's Technical Position on Waste Form'' (Revision 1). Samples of untreated resin waste collected from each solidification vessel before the solidification process were analyzed for concentrations of radionuclides, selected transition metals, and chelating agents to determine the quantities of these chemicals in the waste-form specimens. The chelating agents included oxalic, citric, and picolinic acids. In order to determine the effect of leachant chemical composition and pH on the stability and leachability of the waste forms, waste-form specimens were leached in various leachants. Results of this study indicate that differences in pH do not affect releases from cement-solidified decontamination ion-exchange resin waste forms, but that differences in leachant chemistry and the presence of chelating agents may affect the releases of radionuclides and chelating agents. Also, this study indicates that the cumulative releases of radionuclides and chelating agents are similar for waste- form specimens that decomposed and those that retained their general physical form. 36 refs., 60 figs., 28 tabs.

  16. Ion chromatographic separation of inorganic ions using a combination of hydrophilic interaction chromatographic column and cation-exchange resin column.

    PubMed

    Arai, Kaori; Mori, Masanobu; Hironaga, Takahiro; Itabashi, Hideyuki; Tanaka, Kazuhiko

    2012-04-01

    A combination of hydrophilic interaction chromatographic (HILIC) column and a weakly acidic cation-exchange resin (WCX) column was used for simultaneous separation of inorganic anions and cations by ion chromatography (IC). Firstly, the capability of HILIC column for the separation of analyte ions was evaluated under acidic eluent conditions. The columns used were SeQuant ZIC-HILIC (ZIC-HILIC) with a sulfobetaine-zwitterion stationary phase (ZIC-HILIC) and Acclaim HILIC-10 with a diol stationary phase (HILIC-10). When using tartaric acid as the eluent, the HILIC columns indicated strong retentions for anions, based on ion-pair interaction. Especially, HILIC-10 could strongly retain anions compared with ZIC-HILIC. The selectivity for analyte anions of HILIC-10 with 5 mmol/L tartaric acid eluent was in the order of I(-) > NO3(-) > Br(-) > Cl(-) > H2PO4(-). However, since HILIC-10 could not separate analyte cations, a WCX column (TSKgel Super IC-A/C) was connected after the HILIC column in series. The combination column system of HILIC and WCX columns could successfully separate ten ions (Na+, NH4+, K+, Mg2+, Ca2+, H2PO4(-), Cl(-), Br(-), NO3(-) and I(-)) with elution of 4 mmol/L tartaric acid plus 8 mmol/L 18-crown-6. The relative standard deviations (RSDs) of analyte ions by the system were in the ranges of 0.02% - 0.05% in retention times and 0.18% - 5.3% in peak areas through three-time successive injections. The limits of detection at signal-to-noise ratio of 3 were 0.24 - 0.30 micromol/L for the cations and 0.31 - 1.2 micromol/L for the anions. This system was applied for the simultaneous determination of the cations and the anions in a vegetable juice sample with satisfactory results. PMID:22799200

  17. Production of U{sub 3}O{sub 8} Using Macroporous Sulfonate Cation Exchange Resins in the Bead Form

    SciTech Connect

    Mosley, W.C.

    2001-08-16

    The use of cation exchange resin to product U{sub 3}O{sub 8} suitable for powder metallurgy fabrication of reactor fuel tubes with Al-U{sub 3}O{sub 8} cores is being investigated. This report presents the results of those studies.

  18. Direct Encapsulation of Spent Ion-exchange Resins at the Dukovany Nuclear Power Plant, Czech Republic - 12367

    SciTech Connect

    Fletcher, Paul; Rima, Steve

    2012-07-01

    At the Dukovany Nuclear Power Plant there are large amounts of spent ion exchange resins contained within storage tanks. These resins are a product of the operation of an Active Water Purification System within the Power Plant. Activity levels of the resins are in the range of 105 to 10{sup 6} Bq/l and the main isotopes present are Co-60, Cs-137, Mn-54 and Ag-110m. In order to maintain storage tank availability throughout the planned lifetime of the Power Plant these resins must be removed and disposed of safely. The storage tanks do not have an effective retrieval route for the resins and the installed agitation system is inoperable. A proven system for retrieving and directly encapsulating these resins to a standard required for the Czech repository is described, together with an overview of operational performance. Experience gained from this and other projects has highlighted some common challenges relating to the treatment of ion-exchange resins and sludges. There are common approaches that can assist in overcoming these challenges. 1. Transport resin / sludge type waste over as short a distance as possible to avoid issues with line plugging. 2. Transport these wastes once and once only wherever possible. 3. Try to keep the treatment process as simple as possible. With sludge or resin handling equipment consider the physical properties foremost - radiological issues can be addressed within any subsequent design. 4. Consider the use of dry-mix technologies. This avoids the requirement for expensive and complicated grouting plant. 5. Avoid the use of make up water for transport purposes if at all possible - it introduces secondary waste that needs to be treated at additional cost. 6. Consider alternative disposal techniques. SIAL{sup R} is AMEC's preferred technology as we developed it and understand it well - additionally the waste loading factors are much higher than for cement. 7. Consider final waste volumes when selecting the disposal technique. Disposal

  19. WEAK-ACID ION EXCHANGE FOR REMOVING BARIUM, RADIUM, AND HARDNESS

    EPA Science Inventory

    Weak-acid resin in the hydrogen form was found to effectively remove barium, radium, and hardness, without increasing the sodium content of the product water. The maximum capacity of the weak-acid resin was about 2.3 times that of strong-acid resin, and much less spent regenerant...

  20. Treatment of Perchlorate-Contaminated Groundwater Using Highly-Selective, Regenerable Anion-Exchange Resins at Edwards Air Force Base

    SciTech Connect

    Gu, B.

    2003-05-30

    Selective ion exchange is one of the most effective treatment technologies for removing low levels of perchlorate (ClO{sub 4}{sup -}) from contaminated water because of its high efficiency without adverse impacts on the water quality caused by adding or removing any chemicals or nutrients. This report summarizes both the laboratory and a field pilot-scale studies to determine the ability and efficiency of the bifunctional synthetic resins to remove ClO{sub 4}{sup -} from the contaminated groundwater at the Edwards Air Force Base in California. Regeneration of the resins after groundwater treatment was also evaluated using the FeCl{sub 3}-HCl regeneration technique recently developed at Oak Ridge National Laboratory. On the basis of this study, the bifunctional resin, D-3696 was found to be highly selective toward ClO{sub 4}{sup -} and performed much better than one of the best commercial nitrate-selective resins (Purolite A-520E) and more than an order of magnitude better than the Purolite A-500 resin (with a relatively low selectivity). At an influent concentration of {approx} 450 {micro}g/L ClO{sub 4}{sup -} in groundwater, the bifunctional resin bed treated {approx} 40,000 empty bed volumes of groundwater before a significant breakthrough of ClO{sub 4}{sup -} occurred. The presence of relatively high concentrations of chloride and sulfate in site groundwater did not appear to affect the ability of the bifunctional resin to remove ClO{sub 4}{sup -}. However, the presence of high iron or iron oxyhydroxides and/or biomass in groundwater caused a significant fouling of the resin beds and greatly influenced the effectiveness in regenerating the resins sorbed with ClO{sub 4}{sup -}. Under such circumstances, a prefilter ({approx} 0.5-1 {micro}m) was found to be necessary to remove these particulates and to reduce the risk of fouling of the resin beds. Without significant fouling, the resin bed could be effectively regenerated by the FeCl{sub 3} displacement technique

  1. Unfolding and aggregation of monoclonal antibodies on cation exchange columns: effects of resin type, load buffer, and protein stability.

    PubMed

    Guo, Jing; Carta, Giorgio

    2015-04-01

    The chromatographic behavior of a monoclonal antibody (mAb) that exhibits a pronounced two-peak elution behavior is studied for a range of strong cation exchange resins and with varying load buffer pH and composition. Six stationary phases are considered, including two tentacle-type resins (Fractogel EMD SO3-(M) and Eshmuno S), a resin with grafted polymeric surface extenders (Nuvia S), a resin with a bimodal pore size distribution (POROS HS 50), and two macroporous resins without polymer grafts (Source 30S and UNOsphere Rapid S). The two-peak elution behavior is very pronounced for the tentacle and polymer-grafted resins and for POROS HS 50, but is essentially absent for the two macroporous resins. The extent of this behavior decreases as the buffer pH and concentration increase and, consequently, mAb binding becomes weaker. Replacing sodium with arginine as the buffer counterion, which is expected to decrease the mAb binding strength, nearly completely eliminates the two-peak behavior, while replacing sodium with tetra-n-butylammonium hydroxide, which is expected to increase the mAb binding strength, dramatically exacerbate the effect. As shown by hydrogen-deuterium exchange mass spectrometry (HX-MS), the two-peak elution behavior is related to conformational changes that occur when the mAb binds. These changes result in increased solvent exposure of specific peptides in the Fc-region for either the Fractogel or the Nuvia resin. No significant conformational changes were seen by HX-MS when the mAb was bound to the UNOsphere resin or on the Fractogel resin when arginine was used in lieu of sodium as the load buffer counterion. Experiments with two additional mAbs on the Fractogel resin show that the two-peak elution behavior is dependent on the particular antibody. Circular dichroism suggests that the propensity of different mAbs to either precipitate directly or to form stabilizing intermolecular structures upon exposure to thermal stress can be related to their

  2. Isolation of hydrophilic organic acids from water using nonionic macroporous resins

    USGS Publications Warehouse

    Aiken, G.R.; McKnight, Diane M.; Thorn, K.A.; Thurman, E.M.

    1992-01-01

    A method has been developed for the isolation of hydrophilic organic acids from aquatic environments using Amberlite* * Use of trade names in this report is for identification purposes only and does not constitute endorsement by the U.S. Geological Survey. XAD-4 resin. The method uses a two column array of XAD-8 and XAD-4 resins in series. The hydrophobic organic acids, composed primarily of aquatic fulvic acid, are removed from the sample on XAD-8, followed by the isolation of the more hydrophilic organic acids on XAD-4. For samples from a number of diverse environments, more of the dissolved organic carbon was isolated on the XAD-8 resin (23-58%) than on the XAD-4 resin (7-25%). For these samples, the hydrophilic acids have lower carbon and hydrogen contents, higher oxygen and nitrogen contents, and are lower in molecular weight than the corresponding fulvic acids. 13C NMR analyses indicate that the hydrophilic acids have a lower concentration of aromatic carbon and greater heteroaliphatic, ketone and carboxyl content than the fulvic acid. ?? 1992.

  3. Synthesis of Anomeric Methyl Fructofuranosides and Their Separation on an Ion-Exchange Resin

    ERIC Educational Resources Information Center

    Nurminen, Erkki; Poijarvi, Paivi; Koskua, Katja; Hovinen, Jari

    2007-01-01

    Treatment of d-fructose with methanol in the presence of acid as a catalyst gives a mixture of methyl-[beta]-d-fructopyranoside, methyl-[alpha]-D-fructofuranoside, and methyl-[beta]-d-fructofuranoside, which were separated on an ion exchange column and characterized polarimetrically.

  4. Radioactive Spent Ion-Exchange Resins Conditioning by the Hot Supercompaction Process at Tihange NPP - Early Experience - 12200

    SciTech Connect

    Braet, Johan; Charpentier, David; Centner, Baudouin; Vanderperre, Serge

    2012-07-01

    Spent ion-exchange resins are considered to be problematic waste that, in many cases, requires special approaches and precautions during their conditioning to meet the acceptance criteria for disposal. In Belgium, for economical reasons, the Volume Reduction Factor is a key criterion. After Tractebel Engineering performed a technical and economical comparison of the industrially available systems, Tihange NPP decided to install a spent ion-exchange resins hot supercompaction unit with Tractebel Engineering in the role of architect-engineer. The treatment and conditioning unit processes the spent ion-exchange resins through the following steps: dewatering of the resins, drying the resins under deep vacuum, discharging the dried resins into compactable drums, super-compacting the drums to generate pellets, grouting the pellets into standard 400 litres waste drums (overpacks) licensed for final disposal in the near-surface repository in Belgium. Several developments were required to adapt the reference process and equipment to PWR spent ion-exchange bead resins and Belgian radioactive waste acceptance criteria. In order to avoid cracks on the compacted drum, and external surface contamination from resin leaks, some improvements were achieved to minimize spring-back as well as the risk of cracking the drum wall. Placing the compactable drum inside a second, slightly larger drum, guarantees clean and reproducible pellets. Currently the commissioning phase is on-going. Numerous process validation tests have been completed. An acceptance file was transmitted to the Belgian Waste Management Authority recently. This will be followed by demonstration tests necessary to obtain their final acceptance of the installation. More than 3 800 drums of mixed powdered and bead resins have been processed by the reference Hot Compaction process, achieving a Volume Reduction Factor (VRF) of 2.5. The equipment has been proven to be a reliable technology with low operation and maintenance

  5. Large scale purification of puerarin from Puerariae Lobatae Radix through resins adsorption and acid hydrolysis.

    PubMed

    Guo, Hai-Dong; Zhang, Qing-Feng; Chen, Ji-Guang; Shangguang, Xin-Cheng; Guo, Yu-Xian

    2015-02-01

    Puerarin is the major isoflavone of Puerariae Lobatae Radix. A method for large scale purification of puerarin was developed through resins adsorption and acid hydrolysis. The adsorption properties of six macroporous resins (D101, S-8, H103, X-5, HPD600, AB-8) were compared through the adsorption kinetics and equilibrium adsorption isotherms. Results showed that H103 resin had the best adsorption rate and capacity. The mass transfer zone motion model was further used for analyzing the fixed bed adsorption of H103 resin. Its length of mass transfer zone with 2mg/ml of puerarin in water and 10% ethanol at flow rate of 10ml/min were 41.6 and 47.5cm, while the equilibrium adsorption capacity was 165.03 and 102.88mg/g, respectively. By using 75% ethanol, puerarin could be well desorbed from the resin with recovery of 97.4%. Subsequently, H103 resin was successfully used for puerarin purification from Puerariae Lobatae Radix. The content of total isoflavones and puerarin in the resin adsorption product were 69.25% and 41.78%, respectively, which were about three times increased compared to the crude extract. Then, the product was hydrolyzed by 2.5M HCl at 90°C for 1h. Puerarin with purity of 90% and a byproduct daidzein with purity of 78% were obtained. PMID:25553536

  6. Diterpene resin acids: Major active principles in tall oil against Variegated cutworm,Peridroma saucia (Lepidoptera: Noctuidae).

    PubMed

    Xie, Y; Isman, M B; Feng, Y; Wong, A

    1993-06-01

    Tall oil, a by-product of the kraft process for pulping softwood, has been shown to have insecticidal properties. In the present study, the active principles in tall oil against the variegated cutworm,Peridroma saucia Hübner, were investigated. GC-MS analysis showed that abietic, dehydroabietic, and isopimaric acids were major resin acid components of crude tall oil and depitched tall oil. When crude tall oil samples of differing resin acid composition were incorporated into artificial diet at a concentration of 2.0% fresh weight, they suppressed larval growth by 45-60% compared to controls. This suppression was significantly (P≤0.05) correlated with the equivalent contents of abietic, dehydroabietic, isopimaric, and total resin acids. These results were also evident from a diet choice test, showing that the second-instar larvae obviously selected diets with low levels of resin acids when different diets were randomly arranged in a Petri dish. Bioassays with pure resin acids (abietic, dehydroabietic, and isopimaric acids) demonstrated that all individual chemicals have similar bioactivity against this insect. Comparison of the bioactivities of depitched tall oil and an equivalent mixture of pure resin acids in thePeridroma chronic growth bioassay indicated that pure resin acids and depitched tall oil share a common mode of action to this insect. This study confirms that resin acids are major active principles in tall oil against the variegated cutworm, but other chemicals likely also contribute to the bioactivity of tall oil. PMID:24249127

  7. Permanganate Degradation of Reillex HPQ Ion Exchange Resin for Use in HB-Line

    SciTech Connect

    Walker, B.W.

    1999-06-02

    This study evaluated the use of Reillex TM HPQ resin as a replacement for the Ionac A-641 resin currently authorized for use in H B-Line. The study concentrated on the ability of the existing alkaline permanganate digestion process to convert spent resin for disposal.

  8. Removing hexavalent chromium from subsurface waters with anion-exchange resin

    SciTech Connect

    Torres, R.A.

    1995-06-01

    Some subsurface waters at Lawrence Livermore National Laboratory (LLNL) are contaminated with volatile organic compounds (VOCs). Hexavalent chromium, Cr(VI), is also present in the ground water; however, the source of the Cr(VI) may be natural. The Cr(VI) still must be treated if brought to the surface because its concentration exceeds discharge standards. We are planning facilities for removing the VOCs and Cr(VI) to a level below the discharge standards. The planned treatment includes the following steps: (1) Pumping the water to the surface facility. (2) Purging the VOCs with air and absorbing them on activated carbon. The VOCs in LLNL`s subsurface waters are primarily chlorinated organic solvents, such as dichloroethylene (DCE), trichloroethylene (TCE), perchloroethylene (PCE), and chloroform (CHCl{sub 3}). Contamination levels range from tens to thousands of parts per billion. (3) Filtering the water. (4) Passing the water through anion-exchange resin to remove the Cr. The Cr in LLNL subsurface waters occurs almost entirely as Cr(VI), which exists as the chromate anion, CrO{sub 4}{sup 2-}, at environmental pH. Cr levels range from tens to hundreds of parts per billion. (5) Discharging the treated water into the local arroyos. The relevant discharge criteria are 5 ppb total VOCs, 11 ppb Cr(VI), and pH between 6.5 and 8.5, inclusive. This report describes laboratory experiments undertaken to learn how the proposed treatment facility can be expected to operate. The laboratory results are expected to supply vendors with the detailed performance specifications needed to prepare bids on the Cr removal portion of the treatment facility. The treatment facility is expected to process 60 gallons per minute (gpm) of water by stripping VOCs with 720 standard cubic feet per minute (scfm) of air and removing Cr(VI) with 60 ft{sup 3} of resin.

  9. 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

  10. Dental resins based on dimer acid dimethacrylates: a route to high conversion with low polymerization shrinkage.

    PubMed

    Lu, Hui; Trujillo-Lemon, Marianela; Ge, Junhao; Stansbury, Jeffrey W

    2010-05-01

    Incomplete polymerization, volumetric shrinkage, and shrinkage stress are among the primary disadvantages of current resin-based dental composites. Generally, any attempt to increase final double bond conversion only exacerbates polymerization shrinkage and stress. The use of dimer acid-derived dimethacrylate (DADMA) monomers in novel dental resin formulations is examined in this article as a potential means to address these disparate goals. A series of high molecular weight DADMA monomers with different functional groups used to connect the C36 dimer acid core and the methacrylates were formulated with urethane dimethacrylate (UDMA) and/or ethoxylated bisphenol A dimethacrylate (Bis-EMA) at various compositions to manipulate comonomer compatibility and polymeric mechanical properties. Along with reaction kinetics, dynamic polymerization shrinkage and shrinkage stress were assessed. Specific DADMA monomers demonstrated limited miscibility with either Bis-EMA or UDMA. Appropriate ternary resin formulations produced homogeneous monomeric mixtures capable of controlled polymerization-induced phase separation (PIPS) to yield heterogeneous final polymers. Reduced polymerization shrinkage and stress along with higher conversion was observed for DADMA ternary systems compared with a bisphenol A glycidyl methacrylate (Bis-GMA)/triethylene glycol dimethacrylate (TEGDMA) resin control. The PIPS process resulted in a modest volume recovery and stress relaxation in the later stages of polymerization. These results indicate that certain dimer acid-derived dimethacrylates possess the potential to replace TEGDMA as a reactive diluent in dental resins that display a favorable and unique combination of properties. PMID:20521567

  11. Single-crystalline ceramic whisker-reinforced carboxylic acid-resin composites with fluoride release.

    PubMed

    Xu, H H; Eichmiller, F C; Antonucci, J M; Flaim, G M

    2000-01-01

    Currently available glass-ionomer, resin-modified glass-ionomer, and compomer materials have relatively low strength and toughness and, therefore, are inadequate for use in large stress-bearing posterior restorations. In the present study, ceramic single-crystalline whiskers were mixed with fluorosilicate glass particles and used as fillers to reinforce experimental carboxylic acid-resin composites. The carboxylic acid was a monofunctional methacryloxyethyl phthalate (MEP). Five mass fractions of whisker/(whisker + fluorosilicate glass), and corresponding resin (resin + MEP), were evaluated. Four control materials were also tested for comparison: a glass ionomer, a resin-modified glass ionomer, a compomer, and a hybrid composite resin. Flexural specimens were fabricated to measure the flexural strength, elastic modulus, and work-of-fracture (an indication of toughness). Fluoride release was measured by using a fluoride ion selective electrode. The properties of whisker composites depended on the whisker/(whisker + fluorosilicate glass) mass fraction. At a mass fraction of 0.8, the whisker composite had a flexural strength in MPa (mean +/- sd; n = 6) of 150 +/- 16, significantly higher than that of a glass ionomer (15 +/- 7) or a compomer control (89 +/- 18) (Tukey's multiple comparison test; family confidence coefficient = 0.95). Depending on the ratio of whisker:fluorosilicate glass, the whisker composites had a cumulative fluoride release up to 60% of that of a traditional glass ionomer. To conclude, combining ceramic whiskers and fluorosilicate glass in a carboxylic acid-resin matrix can result in fluoride-releasing composites with significantly improved mechanical properties. PMID:11203805

  12. Acid-Breakable Resin-Based Chemical Amplification Positive Resist for Electron-Beam Mastering: Design and Lithographic Performance

    NASA Astrophysics Data System (ADS)

    Sakamizu, Toshio; Shiraishi, Hiroshi

    2004-07-01

    A positive chemical amplification resist based on acid-catalyzed fragmentation of acetal groups in its main chain has been developed as a means of reducing line-edge roughness. The resist consists of an acid generator, an acid-diffusion controller and an acid-breakable (AB) resin that is synthesized through a co-condensation reaction between polyphenol and aromatic multifunctional vinylether compound. The effects of the fractionation of AB resins on resin properties and line-edge roughness (LER) are evaluated. Although AB resins have wide molecular weight distributions, the density of acetal groups in this AB resin is found to be almost constant except in the lower molecular weight components. The resist with a fractionated resin from which such components are removed provides high-resolution patterns (70-nm-wide pit) with fairly low LER. AFM analysis shows that the surface roughness (SR) of the resist with the fractionated resin is smaller than that of a resist using nonfractionated AB resin, and that the SR value is not altered throughout the range of exposure doses up to just below the start of dissolution. By using the fractionated AB resin, the AB resin-based resist (ABR) is capable of forming sub-100 nm L/S patterns with less than 5 nm of LER (3σ).

  13. EVALUATION OF POTENTIAL ELUANTS FOR NON-ACID ELUTION OF CESIUM FROM SPHERICAL RESORCINOL-FORMALDEHYDE RESIN

    SciTech Connect

    Adu-Wusu, K.; Nash, C.; Pennebaker, F.

    2011-10-23

    Ion Exchange column loading and elution of cesium from spherical resorcinol-formaldehyde resin have been conducted for two potential non-acid eluants -(NH{sub 4}){sub 2}CO{sub 3} and CH{sub 3}COONH{sub 4}. The results revealed encouraging cesium elution performance. 100% elution was achieved in at most 22 hours ({approx}28 bed volumes) of elution. Elution performance was fairly high at 6 hours ({approx}8 bed volumes) of elution for some of the eluants and also practically comparable to the benchmark acid eluant (HNO{sub 3}). Hence, it is quite possible 100% percent elution will be closer to the 6th hour than the 22nd hour. Elution is generally enhanced by increasing the concentration and pH of the eluants, and combining the eluants.

  14. Chemically modified polymeric resins for separation of cations, organic acids, and small polar moleculea by high performance liquid chromatography

    SciTech Connect

    Morris, J.B.

    1993-07-01

    This thesis is divided into 4 parts: a review, ion chromatography of metal cations on carboxylic resins, separation of hydrophilic organic acids and small polar compounds on macroporous resin columns, and use of eluent modifiers for liquid chromatographic separation of carboxylic acids using conductivity detection.

  15. Gamma irradiation-induced modifications of polymers found in nuclear waste embedding processes Part II: The ion-exchange resin

    NASA Astrophysics Data System (ADS)

    Debré, O.; Nsouli, B.; Thomas, J.-P.; Stevenson, I.; Colombini, D.; Romero, M.-A.

    1997-08-01

    Ion exchange resins (IERs) saturated in cesium and borate ions are well representative of low and medium activity nuclear waste to be embedded in an epoxy resin/amine hardener, such a conditioning procedure being under qualification. In order to test these materials in realistic conditions they are externally irradiated (air and water), in mixed beds saturated in fixed ions (cesium and borate) and water. Irradiation effects are evidenced with the HSF-SIMS technique by the variation of the emission characteristic of both the fixed ions, the chemical structure of the IERs and their interrelationship, both from the analysis of the solid material and of the residual or rinsing water. It appears that the fixed ions can be released in surrounding water as a consequence of radiation-induced resin fragments solubility.

  16. SURFACE DEGRADATION OF COMPOSITE RESINS BY ACIDIC MEDICINES AND pH-CYCLING

    PubMed Central

    Valinoti, Ana Carolina; Neves, Beatriz Gonçalves; da Silva, Eduardo Moreira; Maia, Lucianne Cople

    2008-01-01

    This study evaluated the effects of acidic medicines (Dimetapp® and Claritin®), under pH-cycling conditions, on the surface degradation of four composite resins (microhybrid: TPH, Concept, Opallis and Nanofilled: Supreme). Thirty disc-shaped specimens (Ø = 5.0 mm / thickness = 2.0 mm) of each composite were randomly assigned to 3 groups (n = 10): a control and two experimental groups, according to the acidic medicines evaluated. The specimens were finished and polished with aluminum oxide discs, and the surface roughness was measured by using a profilometer. After the specimens were submitted to a pH-cycling regimen and immersion in acidic medicines for 12 days, the surface roughness was measured again. Two specimens for each material and group were analyzed by scanning electron microscopy (SEM) before and after pH-cycling. Data were analyzed by the Student's-t test, ANOVA, Duncan's multiple range test and paired t-test (α=0.05). Significant increase in roughness was found only for TPH in the control group and TPH and Supreme immersed in Claritin® (p<0.05). SEM analyses showed that the 4 composite resins underwent erosion and surface degradation after being subjected to the experimental conditions. In conclusion, although the roughness was slightly affected, the pH-cycling and acidic medicines caused surface degradation of the composite resins evaluated. Titratable acidity seemed to play a more crucial role on surface degradation of composite resins than pH. PMID:19089257

  17. Protein adsorption on ion exchange resins and monoclonal antibody charge variant modulation.

    PubMed

    Guélat, Bertrand; Khalaf, Rushd; Lattuada, Marco; Costioli, Matteo; Morbidelli, Massimo

    2016-05-20

    A novel multicomponent adsorption equilibrium model for proteins on ion-exchange resins is developed on a statistical thermodynamic basis including surface coverage effects and protein-resin and protein-protein interactions. The resulting model exhibits a general competitive Langmuirian behavior and was applied to the study and optimization of the separation of monoclonal antibody charge variants on two strong cation exchangers. The model accounts explicitly for the effect of both pH and salt concentration, and its parameters can be determined in diluted conditions, that is, through physically sound assumptions, all model parameters can be obtained using solely experiments in diluted conditions, and be used to make predictions in overloaded conditions. The parameterization of the model and optimization of the separation is based on a two-step approach. First, gradient experiments in diluted conditions are undertaken in order to determine the model parameters. Based on these experiments and on information about the proteins of interest and the stationary phase used, all the model parameters can be estimated. Second, using the parameterized model, an initial Pareto optimization is undertaken where overloaded operating conditions are investigated. Experiments from this Pareto set are then used to refine the estimation of the model parameters. A second Pareto optimization can then be undertaken, this time with the refined parameters. This can be repeated until a satisfactory set of model parameters is found. This iterative approach is shown to be extremely efficient and to provide large amounts of knowledge based on only a few experiments. It is shown that due to the strong physical foundation of the model and the very low number of adjustable parameters, the number of iterations is expected to be at most two or three. Furthermore, the model based tool is improved as more experimental knowledge is provided, allowing for better estimations of the chromatographic

  18. Sodium Concentration Measurement during Hemodialysis through Ion-Exchange Resin and Conductivity Measure Approach: In Vitro Experiments

    PubMed Central

    Tura, Andrea; Sbrignadello, Stefano; Mambelli, Emanuele; Ravazzani, Paolo; Santoro, Antonio; Pacini, Giovanni

    2013-01-01

    Sodium measurement during hemodialysis treatment is important to preserve the patient from clinical events related to hypo- or hyper-natremia Usually, sodium measurement is performed through laboratory equipment which is typically expensive, and requires manual intervention. We propose a new method, based on conductivity measurement after treatment of dialysate solution through ion-exchange resin. To test this method, we performed in vitro experiments. We prepared 40 ml sodium chloride (NaCl) samples at 280, 140, 70, 35, 17.5, 8.75, 4.375 mEq/l, and some “mixed samples”, i.e., with added potassium chloride (KCl) at different concentrations (4.375-17.5 mEq/l), to simulate the confounding factors in a conductivity-based sodium measurement. We measured the conductivity of all samples. Afterwards, each sample was treated for 1 min with 1 g of Dowex G-26 resin, and conductivity was measured again. On average, the difference in the conductivity between mixed samples and corresponding pure NaCl samples (at the same NaCl concentration) was 20.9%. After treatment with the exchange resin, it was 14.7%, i.e., 42% lower. Similar experiments were performed with calcium chloride and magnesium chloride as confounding factors, with similar results. We also performed some experiments on actual dialysate solution during hemodialysis sessions in 15 patients, and found that the correlation between conductivity measures and sodium concentration improved after resin treatment (R=0.839 before treatment, R=0.924 after treatment, P<0.0001). We conclude that ion-exchange resin treatment coupled with conductivity measures may improve the measurement of sodium compared to conductivity measures alone, and may become a possible simple approach for continuous and automatic sodium measurement during hemodialysis. PMID:23844253

  19. Potential problems associated with ion-exchange resins used in the decontamination of light-water reactor systems

    SciTech Connect

    Soo, P.; Adams, J.W.; Kempf, C.R.

    1987-01-01

    During a typical decontamination event, ion-exchange resin beds are used to remove corrosion products (radioactive and nonradioactive) and excess decontamination reagents from waste streams. The spent resins may be solidified in a binder, such as cement, or sealed in a high-integrity container (HIC) in order to meet waste stability requirements specified by the Nuclear Regulatory Commission. Lack of stability of low-level waste in a shallow land burial trench may lead to trench subsidence, enhanced water infiltration and waste leaching, which would result in accelerated transport of radionuclides and the complexing agents used for decontamination. The current program is directed at investigating safety problems associated with the handling, solidification and containerization of decontamination resin wastes. The three tasks currently underway include freeze-thaw cycling of cementitious and vinyl ester-styrene forms to determine if mechanical integrity is compromised, a study of the corrosion of container materials by spent decontamination waste resins, and investigations of resin degradation mechanisms.

  20. 21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Partial phosphoric acid esters of polyester resins. 175.260 Section 175.260 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) INDIRECT FOOD ADDITIVES: ADHESIVES AND COMPONENTS OF COATINGS Substances for Use as Components of Coatings § 175.260...

  1. 21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Partial phosphoric acid esters of polyester resins. 175.260 Section 175.260 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: ADHESIVES AND COMPONENTS OF COATINGS Substances for Use...

  2. 21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Partial phosphoric acid esters of polyester resins. 175.260 Section 175.260 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: ADHESIVES AND COMPONENTS OF COATINGS Substances for Use...

  3. 21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Partial phosphoric acid esters of polyester resins. 175.260 Section 175.260 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: ADHESIVES AND COMPONENTS OF COATINGS Substances for Use...

  4. REMOVAL OF TECHNETIUM 99 FROM THE EFFLUENT TREATMENT FACILITY (ETF) BASIN 44 USING PUROLITE A-530E & REILLEX HPQ & SYBRON IONAC SR-7 ION EXCHANGE RESINS

    SciTech Connect

    DUNCAN JB

    2004-10-29

    This report documents the laboratory testing and analyses as directed under the test plan, RPP-20407. The overall goal of this task was to evaluate and compare candidate anion exchange resins for their capacity to remove Technetium-99 from Basin 44 Reverse Osmosis reject stream. The candidate resins evaluated were Purolite A-530E, Reillex HPQ, and Sybron IONAC SR-7.

  5. Curing time effect on the fraction of {sup 137}Cs from cement-ion exchange resins-bentonite clay composition

    SciTech Connect

    Plecas, Ilija; Dimovic, Slavko

    2007-07-01

    To assess the safety of disposal of radioactive waste material in cement, curing conditions and time of leaching radionuclides {sup 137}Cs have been studied. Leaching tests in cement-ion exchange resins-bentonite matrix, were carried out in accordance with a method recommended by IAEA. Curing conditions and curing time prior to commencing the leaching test are critically important in leach studies since the extent of hydration of the cement materials determines how much hydration product develops and whether it is available to block the pore network, thereby reducing leaching. Incremental leaching rates R{sub n}(cm/d) of {sup 137}Cs from cement ion exchange resins-bentonite matrix after 180 days were measured. The results presented in this paper are examples of results obtained in a 20-year concrete testing project which will influence the design of the engineer trenches system for future central Serbian radioactive waste storing center. (authors)

  6. Immobilization of the Radionuclides from Spent Ion-Exchange Resins Using Vitrification

    SciTech Connect

    Hutson, N. D.; Crawford, C. L.; Russo, D. O.; Sterba, M. E.

    2002-02-25

    Approximately 60 g of an iron-enriched borosilicate glass was made in the radiochemical labs of the Savannah River Technology Center (SRTC). The glass was made to demonstrate the immobilization of the radioisotopes contained on representative Argentine ion exchange resins (similar to those used at the Embalse plant). The product was approximately 90% amorphous and was quite durable as measured by the release rates from the Product Consistency Test (PCT). The release rates were considerably better than those of the U. S. High Level Waste (HLW) benchmark DWPF EA glass. The release rate of the Cs-137 was predictably similar to that of Na and Li. No Co-60 or Sr-90 was measured in the PCT leachate. The mass balances for the inactive additives were quite good. Of the radioisotopes, approximately 71% of Cs-137 was accounted for in the glass product. This was similar to the Na mass balance. Approximately 89% of the Co-60 was accounted for in the glass product.

  7. Adsorption equilibrium and kinetics of monomer-dimer monoclonal antibody mixtures on a cation exchange resin.

    PubMed

    Reck, Jason M; Pabst, Timothy M; Hunter, Alan K; Wang, Xiangyang; Carta, Giorgio

    2015-07-10

    Adsorption equilibrium and kinetics are determined for a monoclonal antibody (mAb) monomer and dimer species, individually and in mixtures, on a macroporous cation exchange resin both under the dilute limit of salt gradient elution chromatography and at high protein loads and low salt based on batch adsorption equilibrium and confocal laser scanning microscopy (CLSM) experiments. In the dilute limit and weak binding conditions, the dimer/monomer selectivity in 10mM phosphate at pH 7 varies between 8.7 and 2.3 decreasing with salt concentration in the range of 170-230mM NaCl. At high protein loads and strong binding conditions (0-60mM NaCl), the selectivity in the same buffer is near unity with no NaCl added, but increases gradually with salt concentration reaching high values between 2 and 15 with 60mM added NaCl. For these conditions, the two-component adsorption kinetics is controlled by pore diffusion and is predicted approximately by a dual shrinking core model using parameters based on single component equilibrium and kinetics measurements. PMID:26028510

  8. Kinetics of Ethyl Acetate Synthesis Catalyzed by Acidic Resins

    ERIC Educational Resources Information Center

    Antunes, Bruno M.; Cardoso, Simao P.; Silva, Carlos M.; Portugal, Ines

    2011-01-01

    A low-cost experiment to carry out the second-order reversible reaction of acetic acid esterification with ethanol to produce ethyl acetate is presented to illustrate concepts of kinetics and reactor modeling. The reaction is performed in a batch reactor, and the acetic acid concentration is measured by acid-base titration versus time. The…

  9. 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.

  10. Enrichment of boron-10 by inverse-frontal chromatography using quaternized 4-vinylpyridine-divinylbenzene anion-exchange resin

    SciTech Connect

    Mardan, A.

    1997-08-01

    In order to enrich {sup 10}B, 40 meter band migration of boric acid-mannitol with hydrochloric acid solution was performed by inverse frontal chromatography on a porous, 25% crosslinked, 38% quaternized 4-vinylpyridine-divinylbenzene resin. The maximum enrichment (R{sub L}) of {sup 10}B was 94.15%. The overall process parameters, namely slope coefficient (k) and separation coefficient (e), were found to be 0.1282 cm{sup {minus}1} and 0.02967, respectively.

  11. Degradation of 2,4,6-Trichlorophenol Using Hydrogen Peroxide Catalyzed by Nanoscale Zero-Valent Iron Supported on Ion Exchange Resin.

    PubMed

    Tai, Chao; She, Jiaping; Yin, Yongguang; Zhao, Tongqian; Wu, Li

    2016-06-01

    Nanoscale zero-valent iron (NZVI) supported on ion exchange resin was prepared and characterized by scanning electron microscope and energy dispersive spectroscopy, with a simple model developed for describing the catalyst. The degradation of 2,4,6-trichlorophenol (2,4,6-TCP) by hydrogen peroxide using NZVI supported on ion exchange resin as the catalyst, was studied. The results showed that 2,4,6-TCP with a concentration of 1 mmol L(-1) could be well degraded into low molecule weight organic acids in two hours. The optimized condition was as follows: pH, 3.0; temperature, 35 degrees C; catalyst dosage, 1.5 g; and hydrogen peroxide, 0.16 mmol L(-1). The catalyst has good reusability, with no catalytic efficiency decreasing even after ten times recycles. A possible mechanism of 2,4,6-TCP degradation was proposed, based on the products indentified by GC-MS after derived using trimethylsulfonium hydroxide. PMID:27427643

  12. Stability Of A Carbon-Dioxide-Removing Resin

    NASA Technical Reports Server (NTRS)

    Wydeven, Theodore; Wood, Peter

    1990-01-01

    Report describes experiments determing long-term chemical stability of IRA-45, commerical ion-exchange resin candidate for use in removing CO2 from atmosphere of Space Station. In proposed system, cabin air passes through resin, and acidic CO2 absorbed by weakly-basic hydrated diethylenetriamine bonded to porous resin substrate. When resin absorbs all CO2, disconnects from airstream and heated with steam to desorb CO2. Resin reuseable. Removed by post-treating process air with phosphoric acid on charcoal. Other chemicals removed by trace-contaminant-control subsystem of Space Station.

  13. New selective anion-exchange resins for nitrate removal from contaminated drinking water and studies on analytical anion-exchange chromatography

    SciTech Connect

    Lockridge, J.E.

    1989-01-01

    Phosphonium resins and ammonium resins of composition resin-R{sub 3}P{sup +}A{sup {minus}} where R is varied from methyl to pentyl were evaluated for nitrate/sulfate selectivity, capacity and nitrate decontamination of drinking water. Phosphonium resins were found to be more nitrate selective and have higher capacities than ammonium resins. A mixed bed process, where nitrate removal and water softening is accomplished in a single column, was also evaluated. A small piece of silver wire, coated with an insoluble silver salt, works well as a selective potentiometric detector for halide ions in ion chromatography. A silver-silver chloride electrode was found to be a selective and reproducible detector for chloride, bromide, iodide, thiocyanate and thiosulfate anions separated by ion chromatography. Calibration curves were non-linear and had slopes ranging from 40 to 60 mV/log concentrations. A working range of 0.05 to 2 mM was used. Two methods for the determination of aluminum by anion chromatography are presented. In the first method, a standard excess of fluoride ion is added to the sample. Evidence is given for the formation of a strong complex of neutral aluminum trifluoride which elutes very quickly from an anion exchange column. The excess fluoride is retained and can be determined. The aluminum concentration can then be related to the difference in fluoride peak height between the sample and standard. In a second method, Al(III) is determined directly by anion chromatography when sodium phthalate is used as an eluent. It was found that Al(III)-phthalate complexes thus formed would show some retention on an anion exchange column. The method is uniquely insensitive to the presence of many foreign cations. Al(III) was successfully determined, by this method, in a 40-fold molar excess of iron(III).

  14. Determination of uranium isotopes in environmental samples by anion exchange in sulfuric and hydrochloric acid media.

    PubMed

    Popov, L

    2016-09-01

    Method for determination of uranium isotopes in various environmental samples is presented. The major advantages of the method are the low cost of the analysis, high radiochemical yields and good decontamination factors from the matrix elements, natural and man-made radionuclides. The separation and purification of uranium is attained by adsorption with strong base anion exchange resin in sulfuric and hydrochloric acid media. Uranium is electrodeposited on a stainless steel disk and measured by alpha spectrometry. The analytical method has been applied for the determination of concentrations of uranium isotopes in mineral, spring and tap waters from Bulgaria. The analytical quality was checked by analyzing reference materials. PMID:27451111

  15. 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.

  16. Simultaneous separation and detection of actinides in acidic solutions using an extractive scintillating resin.

    PubMed

    Roane, J E; DeVol, T A

    2002-11-01

    An extractive scintillating resin was evaluated for the simultaneous separation and detection of actinides in acidic solutions. The transuranic extractive scintillating (TRU-ES) resin is composed of an inert macroporous polystyrene core impregnated with organic fluors (diphenyloxazole and 1,4-bis-(4-methyl-5-phenyl-2-oxazolyl)benzene) and an extractant (octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide in tributyl phosphate). The TRU-ES resin was packed into FEP Teflon tubing to produce a flow cell (0.2-mL free column volume), which is placed into a scintillation detection system to obtain pulse height spectra and time series data during loading and elution of actinides onto/from the resin. The alpha-particle absolute detection efficiencies ranged from 77% to 96.5%, depending on the alpha energy and quench. In addition to the on-line analyses, off-line analyses of the effluent can be conducted using conventional detection methods. The TRU-ES resin was applied to the quantification of a mixed radionuclide solution and two actual waste samples. The on-line characterization of the mixed radionuclide solution was within 10% of the reported activities whereas the agreement with the waste samples was not as good due to sorption onto the sample container walls and the oxidation state of plutonium. Agreement between the on-line and off-line analyses was within 35% of one another for both waste samples. PMID:12433098

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

    SciTech Connect

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

    1999-04-02

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

  18. Sorption of uranyl ions from various acido systems by amphoteric epoxy amine ion-exchange resins

    SciTech Connect

    Rychkov, V.N.; Radionov, B.K.; Molochnikov, L.S.

    1995-03-01

    Sorption of uranyl ions by epoxy amine ampholytes with N-monomethylenephosphonic acid groups modified with pyridine or quaternary ammonium groups was studied under dynamic conditions. Heterocyclic nitrogen favors sorption of uranyl ion from fluoride, sulfate, and fluoride-sulfate solutions. The ESR studies of mono- and bimetallic forms of nitrogen-containing ampholytes with copper(II) as paramagnetic marker revealed the characteristics of uranium(VI) interaction with cation- and anion-exchange groups and its dependence on the fluoride content in solution.

  19. Acute effects of chlorinated resin acid exposure on juvenile rainbow trout, Oncorhynchus mykiss

    SciTech Connect

    Kennedy, C.J.; Sweeting, R.M.; Farrell, A.P.; McKeown, B.A.; Johansen, J.A.

    1995-06-01

    The effects of an acute exposure to either 14-monochlorodehydroabietic acid (MCDHAA) or 12,14-dichlorodehydroabietic acid (DCDHAA) were examined in juvenile rainbow trout, Oncorhynchus mykiss. The experimentally determined 96-h LC50 values (and their 95% confidence limits) were 1.03 (0.72, 1.48) and 0.91 (0.70, 1.21) mg/L, for MCDHAA and DCDHAA, respectively. To measure effects on several biochemical parameters, swimming performance, and disease resistance, juvenile trout were exposed for 24 h to sublethal concentrations of one or the other resin acid in an intermittent-flow respirometer. Hematocrit, plasma lactate, and liver protein were significantly affected by exposure to the highest dose (80% of the 96-h LC50 value) of either of the resin acids. Plasma cortisol levels were 14- and 3-fold higher than were controls. Resistance to infection by Aeromonas salmonicida was significantly reduced; the cumulative percent mortalities due to furunculosis in fish exposed to MCDHAA or DCDHAA reached 20 and 26%, respectively. Swimming performance, measured as critical swimming speed (mean values 6.32 {+-} 0.20 and 5.93 {+-} 0.15 body lengths per second for MCDHAA and DCDHAA, respectively), was not significantly affected by resin acid exposure.

  20. Efficiencies and Optimization of Weak Base Anion Ion-Exchange Resin for Groundwater Hexavalent Chromium Removal at Hanford

    SciTech Connect

    Nesham, Dean O.; Ivarson, Kristine A.; Hanson, James P.; Miller, Charles W.; Meyers, P.; Jaschke, Naomi M.

    2014-02-03

    The U.S. Department of Energy’s (DOE’s) contractor, CH2M HILL Plateau Remediation Company, has successfully converted a series of groundwater treatment facilities to use a new treatment resin that is delivering more than $3 million in annual cost savings and efficiency in treating groundwater contamination at the DOE Hanford Site in southeastern Washington State. During the production era, the nuclear reactors at the Hanford Site required a continuous supply of high-quality cooling water during operations. Cooling water consumption ranged from about 151,417 to 378,541 L/min (40,000 to 100,000 gal/min) per reactor, depending on specific operating conditions. Water from the Columbia River was filtered and treated chemically prior to use as cooling water, including the addition of sodium dichromate as a corrosion inhibitor. Hexavalent chromium was the primary component of the sodium dichromate and was introduced into the groundwater at the Hanford Site as a result of planned and unplanned discharges from the reactors starting in 1944. Groundwater contamination by hexavalent chromium and other contaminants related to nuclear reactor operations resulted in the need for groundwater remedial actions within the Hanford Site reactor areas. Beginning in 1995, groundwater treatment methods were evaluated, leading to the use of pump-and-treat facilities with ion exchange using Dowex™ 21K, a regenerable, strong-base anion exchange resin. This required regeneration of the resin, which was performed offsite. In 2008, DOE recognized that regulatory agreements would require significant expansion for the groundwater chromium treatment capacity. As a result, CH2M HILL performed testing at the Hanford Site in 2009 and 2010 to demonstrate resin performance in the specific groundwater chemistry at different waste sites. The testing demonstrated that a weak-base anion, single-use resin, specifically ResinTech SIR-700 ®, was effective at removing chromium, had a significantly

  1. Measurement of gas-phase ammonia and amines in air by collection onto an ion exchange resin and analysis by ion chromatography

    NASA Astrophysics Data System (ADS)

    Dawson, M. L.; Perraud, V.; Gomez, A.; Arquero, K. D.; Ezell, M. J.; Finlayson-Pitts, B. J.

    2014-02-01

    Ammonia and amines are common trace gases in the atmosphere and have a variety of both biogenic and anthropogenic sources, with a major contribution coming from agricultural sites. In addition to their malodorous nature, both ammonia and amines have been shown to enhance particle formation from acids such as nitric, sulfuric and methanesulfonic acids, which has implications for visibility, human health and climate. A key component of quantifying the effects of these species on particle formation is accurate gas-phase measurements in both laboratory and field studies. However, these species are notoriously difficult to measure as they are readily taken up on surfaces, including onto glass surfaces from aqueous solution as established in the present studies. We describe here a novel technique for measuring gas-phase ammonia and amines that involves uptake onto a weak cation exchange resin followed by extraction and analysis using ion chromatography. Two variants, one for ppb concentrations in air and the second with lower (ppt) detection limits, are described. The latter involves the use of a custom-designed high-pressure cartridge to hold the resin for in-line extraction. These methods avoid the use of sampling lines, which can lead to significant inlet losses of these compounds. They also have the advantages of being relatively simple and inexpensive. The applicability of this technique to ambient air is demonstrated in measurements made near a cattle farm in Chino, CA.

  2. Measurement of gas-phase ammonia and amines in air by collection onto an ion exchange resin and analysis by ion chromatography

    NASA Astrophysics Data System (ADS)

    Dawson, M. L.; Perraud, V.; Gomez, A.; Arquero, K. D.; Ezell, M. J.; Finlayson-Pitts, B. J.

    2014-08-01

    Ammonia and amines are common trace gases in the atmosphere and have a variety of both biogenic and anthropogenic sources, with a major contribution coming from agricultural sites. In addition to their malodorous nature, both ammonia and amines have been shown to enhance particle formation from acids such as nitric, sulfuric and methanesulfonic acids, which has implications for visibility, human health and climate. A key component of quantifying the effects of these species on particle formation is accurate gas-phase measurements in both laboratory and field studies. However, these species are notoriously difficult to measure as they are readily taken up on surfaces, including onto glass surfaces from aqueous solution as established in the present studies. We describe here a novel technique for measuring gas-phase ammonia and amines that involves uptake onto a weak cation exchange resin followed by extraction and analysis using ion chromatography. Two variants - one for parts per billion concentrations in air and the second with lower (parts per trillion) detection limits - are described. The latter involves the use of a custom-designed high-pressure cartridge to hold the resin for in-line extraction. These methods avoid the use of sampling lines, which can lead to significant inlet losses of these compounds. They also have the advantages of being relatively simple and inexpensive. The applicability of this technique to ambient air is demonstrated in measurements made near a cattle farm in Chino, CA.

  3. An investigation of the applicability of the new Reillex(tm)-HPQ anion exchange resin system for technetium/rhenium and uranium in the Hanford waste tanks

    NASA Astrophysics Data System (ADS)

    Ashley, K. R.; Ball, J. R.; Cobb, S. L.; Adams, J. M.; Young, D. A.

    1994-09-01

    Results of the measurements of the exchange capacity and K(sub d) values for ReO4(-) on Reillex(tm)-HPQ as a function of nitric acid and hydroxide concentration, temperature, and ten months time will be reported. Results of the breakthrough volumes for UO2(2+) on Reillex-HPQ chromatography columns as a function of carbonate ion concentration in high nitrate ion concentrations and various column sizes will be reported. Individual sections of this report describe the following: the sorption behavior of ReO4(-) on the Reillex-HPQ between pH 2 and 12 in 1.00 M NaNO3; results of the measurements of the K(sub d) values for ReO4(-) on Reillex-HPQ and on Reillex-HP as a function of nitrate and hydroxide ion concentrations; the sorption behavior of ReO4(-) on Reillex-HPQ resin in base with time as a variable; the results of the early attempts at determining the K(sub d) values for Na4UO2(CO3)3 on Reillex-HPQ resin; and the breakthrough of UO2(NO3)2 in varying nitric acid solutions on Reillex-HPQ columns.

  4. Effect of acidic solutions on the surface degradation of a micro-hybrid composite resin.

    PubMed

    Münchow, Eliseu A; Ferreira, Ana Cláudia A; Machado, Raissa M M; Ramos, Tatiana S; Rodrigues-Junior, Sinval A; Zanchi, Cesar H

    2014-01-01

    Composite resins may undergo wear by the action of chemical substances (e.g., saliva, alcohol, bacterial acids) of the oral environment, which may affect the material's structure and surface properties. This study evaluated the effect of acidic substances on the surface properties of a micro-hybrid composite resin (Filtek Z-250). Eighty specimens were prepared, and baseline hardness and surface roughness (KMN0 and Ra0, respectively) were measured. The specimens were subjected to sorption (SO) and solubility (SL) tests according to ISO 4049:2009, but using different storage solutions: deionized water; 75/25 vol% ethanol/water solution; lactic acid; propionic acid; and acetic acid. The acids were used in two concentrations: PA and 0.02 N. pH was measured for all solutions and final hardness (KMN1) and surface roughness (Ra1) were measured. Data were analyzed with paired t-tests and one-way ANOVA and Tukey's test (a=5%). All solutions decreased hardness and increased the Ra values, except for the specimens stored in water and 0.02 N lactic acid, which maintained the hardness. All solutions produced similar SO and SL phenomena, except for the 0.02 N lactic acid, which caused lower solubility than the other solutions. Ethanol showed the highest pH (6.6) and the 0.02 N lactic acid the lowest one (2.5). The solutions affected negatively the surface properties of the composite resin; in addition, an acidic pH did not seem to be a significant factor that intensifies the surface degradation phenomena. PMID:25250496

  5. Continuous biodiesel production in a fixed bed reactor packed with anion-exchange resin as heterogeneous catalyst.

    PubMed

    Ren, Yanbiao; He, Benqiao; Yan, Feng; Wang, Hong; Cheng, Yu; Lin, Ligang; Feng, Yaohui; Li, Jianxin

    2012-06-01

    A continuous biodiesel production from the transesterification of soybean oil with methanol was investigated in a fixed bed reactor packed with D261 anion-exchange resin as a heterogeneous catalyst. The conversion to biodiesel achieved 95.2% within a residence time 56 min under the conditions: reaction temperature of 323.15K, n-hexane/soybean oil weight rate of 0.5, methanol/soybean oil molar ratio of 9:1 and feed flow rate of 1.2 ml/min. The resin can be regenerated in-situ and restored to the original activity to achieve continuous production after the resin deactivation. The product obtained was mainly composed of methyl esters. No glycerol in the product was detected due to the resin adsorbing glycerol in the fixed bed, which solved the issue of glycerol separation from biodiesel. It is believed that the fixed bed reactor with D261 has a potential commercial application in the transesterification of triglyceride. PMID:22138595

  6. 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.

  7. Experimental design approach for identification of the factors influencing the γ-radiolysis of ion exchange resins

    NASA Astrophysics Data System (ADS)

    Rébufa, C.; Traboulsi, A.; Labed, V.; Dupuy, N.; Sergent, M.

    2015-01-01

    Gamma radiolysis was investigated on a nuclear grade mixed bed ion exchange resin and its pure components under different irradiation conditions. Screening designs were performed to identify the factors influencing gas production after their γ-radiolysis and to compare their γ-degradation stability. Only hydrogen and trimethylamine quantities were considered as the response in the experimental designs. The other detected gases and water-soluble products were used to improve the resins degradation. Aerobic irradiation atmosphere decreased the H2g production of AmbOH, MB400, and amines. The water presence increased the H2g quantities for AmbH and decreased those for MB400 resin. Liquid water had no effect on H2g production from AmbOH but was favorable to increased amine production. The H2g production of AmbH increased with the absorbed dose that had little effect on the AmbOH resin. No impact of dose on the H2g production was detected for MB400 that appeared to be less degraded.

  8. Adsorption and removal of clofibric acid and diclofenac from water with MIEX resin.

    PubMed

    Lu, Xian; Shao, Yisheng; Gao, Naiyun; Chen, Juxiang; Zhang, Yansen; Wang, Qiongfang; Lu, Yuqi

    2016-10-01

    This study demonstrates the use of MIEX resin as an efficient adsorbent for the removal of clofibric acid (CA) and diclofenac (DCF). The adsorption performance of CA and DCF are investigated by a batch mode in single-component or bi-component adsorption system. Various factors influencing the adsorption of CA and DCF, including initial concentration, contact time, adsorbent dosage, initial solution pH, agitation speed, natural organic matter and coexistent anions are studied. The Langmuir model can well describe CA adsorption in single-component system, while the Freundlich model gives better fitting in bi-component system. The DCF adsorption can be well fitted by the Freundlich model in both systems. Thermodynamic analyses show that the adsorption of CA and DCF is an endothermic (ΔH(o) > 0), entropy driven (ΔS(o) > 0) process and more randomness exists in the DCF adsorption process. The values of Gibbs free energy (ΔG(o) < 0) indicate the adsorption of DCF is spontaneous but nonspontaneous (ΔG(o) > 0) for CA adsorption. The kinetic data suggest the adsorption of CA and DCF follow the pseudo-first-order model in both systems and the intra-particle is not the unique rate-limiting step. The adsorption process is controlled simultaneously by external mass transfer and surface diffusion according to the surface diffusion modified Biot number (Bis) ranging from 1.06 to 26.15. Moreover, the possible removal mechanism for CA and DCF is respectively proposed based on the ion exchange stoichiometry. PMID:27448753

  9. 40 CFR 414.50 - Applicability; description of the thermosetting resins subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... the products classified under SIC 28214 thermosetting resins including those resins and resin groups listed below. Product groups are indicated with an asterisk (*). *Alkyd Resins Dicyanodiamide Resin *Epoxy Resins *Fumaric Acid Polyesters *Furan Resins Glyoxal-Urea Formaldehyde Textile Resin...

  10. 40 CFR 414.50 - Applicability; description of the thermosetting resins subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... the products classified under SIC 28214 thermosetting resins including those resins and resin groups listed below. Product groups are indicated with an asterisk (*). *Alkyd Resins Dicyanodiamide Resin *Epoxy Resins *Fumaric Acid Polyesters *Furan Resins Glyoxal-Urea Formaldehyde Textile Resin...

  11. 40 CFR 414.50 - Applicability; description of the thermosetting resins subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... the products classified under SIC 28214 thermosetting resins including those resins and resin groups listed below. Product groups are indicated with an asterisk (*). *Alkyd Resins Dicyanodiamide Resin *Epoxy Resins *Fumaric Acid Polyesters *Furan Resins Glyoxal-Urea Formaldehyde Textile Resin...

  12. 40 CFR 414.50 - Applicability; description of the thermosetting resins subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the products classified under SIC 28214 thermosetting resins including those resins and resin groups listed below. Product groups are indicated with an asterisk (*). *Alkyd Resins Dicyanodiamide Resin *Epoxy Resins *Fumaric Acid Polyesters *Furan Resins Glyoxal-Urea Formaldehyde Textile Resin...

  13. 40 CFR 414.50 - Applicability; description of the thermosetting resins subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... the products classified under SIC 28214 thermosetting resins including those resins and resin groups listed below. Product groups are indicated with an asterisk (*). *Alkyd Resins Dicyanodiamide Resin *Epoxy Resins *Fumaric Acid Polyesters *Furan Resins Glyoxal-Urea Formaldehyde Textile Resin...

  14. 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.

  15. Fully automated synthesis module for preparation of S-(2-[(18)F]fluoroethyl)-L-methionine by direct nucleophilic exchange on a quaternary 4-aminopyridinium resin.

    PubMed

    Tang, Ganghua; Wang, Mingfang; Tang, Xiaolan; Luo, Lei; Gan, Manquan

    2003-07-01

    A fully automated preparation of S-(2-[(18)F]fluoroethyl)-L-methionine (FEMET), an amino acid tracer for tumor imaging with positron emission tomography, is described. [(18)F]F(-) was produced via nuclear reaction (18)O(p,n) [(18)F] at PETtrace Cyclotron. Direction nucleophilic fluorination reaction of [(18)F]fluoride with 1,2-di(4-methylphenylsulfonyloxy)ethane on a quaternary 4-(4-methylpiperidinyl)pyridinium functionalized polystyrene anion exchange resin gave 2-[(18)F]-1-(4-methylphenyl-sulfonyloxy)ethane, and then [(18)F]fluoroalkylation of L-homocysteine thiolactone with 2-[(18)F]-1-(4-methylphenylsulfonyloxy)ethane yielded FEMET. The overall radiochemical yield with no decay correction was about 10%, the whole synthesis time was about 52 min, and the radiochemical purity was above 95%. PMID:12831988

  16. Bonding effectiveness of self-adhesive and conventional-type adhesive resin cements to CAD/CAM resin blocks. Part 2: Effect of ultrasonic and acid cleaning.

    PubMed

    Kawaguchi, Asuka; Matsumoto, Mariko; Higashi, Mami; Miura, Jiro; Minamino, Takuya; Kabetani, Tomoshige; Takeshige, Fumio; Mine, Atsushi; Yatani, Hirofumi

    2016-01-01

    The present study assessed the effect of ultrasonic and acid cleaning on resin cement bonding to CAD/CAM resin blocks. One of two resin cements, PANAVIA V5 (PV5) or PANAVIA SA CEMENT HANDMIX (PSA), were bonded to one of 24 CAD/CAM blocks (KATANA AVENCIA BLOCK). Each cement group was divided into four subgroups: no cleaning (Ctl), ultrasonic cleaning (Uc), acid cleaning (Ac) and Uc+Ac. Micro-tensile bond strengths (µTBSs) were measured immediately and 1, 3, and 6 months after water storage. Block surfaces after each treatment were analyzed by scanning electron microscopy. Analysis of variance revealed a statistically significant effect for the parameters 'surface treatment' (p<0.001, F=40), 'resin cement' (p<0.001, F=696) and 'water aging' (p<0.001, F=71). The PV5 group exhibited higher µTBS values than the PSA group. Although cleaning after sandblasting was effective in removing residual alumina particles, it did not affect the long-term bonding durability with non-contaminated CAD/CAM resin blocks. PMID:26830822

  17. The Role of Lactic Acid Adsorption by Ion Exchange Chromatography

    PubMed Central

    Zhang, Tongcun; Zhang, Jian; Jia, Shiru; Yu, Changyan; Jiang, Kunyu; Gao, Nianfa

    2010-01-01

    Background The polyacrylic resin Amberlite IRA-67 is a promising adsorbent for lactic acid extraction from aqueous solution, but little systematic research has been devoted to the separation efficiency of lactic acid under different operating conditions. Methodology/Principal Findings In this paper, we investigated the effects of temperature, resin dose and lactic acid loading concentration on the adsorption of lactic acid by Amberlite IRA-67 in batch kinetic experiments. The obtained kinetic data followed the pseudo-second order model well and both the equilibrium and ultimate adsorption slightly decreased with the increase of the temperature at 293–323K and 42.5 g/liter lactic acid loading concentration. The adsorption was a chemically heterogeneous process with a mean free energy value of 12.18 kJ/mol. According to the Boyd_plot, the lactic acid uptake process was primarily found to be an intraparticle diffusion at a lower concentration (<50 g/liter) but a film diffusion at a higher concentration (>70 g/liter). The values of effective diffusion coefficient Di increased with temperature. By using our Equation (21), the negative values of ΔG° and ΔH° revealed that the adsorption process was spontaneous and exothermic. Moreover, the negative value of ΔS° reflected the decrease of solid-liquid interface randomness at the solid-liquid interface when adsorbing lactic acid on IRA-67. Conclusions/Significance With the weakly basic resin IRA-67, in situ product removal of lactic acid can be accomplished especially from an open and thermophilic fermentation system without sterilization. PMID:21085600

  18. Fundamental aspects related to batch and fixed-bed sulfate sorption by the macroporous type 1 strong base ion exchange resin Purolite A500.

    PubMed

    Guimarães, Damaris; Leão, Versiane A

    2014-12-01

    Acid mine drainage is a natural process occurring when sulfide minerals such as pyrite are exposed to water and oxygen. The bacterially catalyzed oxidation of pyrite is particularly common in coal mining operations and usually results in a low-pH water polluted with toxic metals and sulfate. Although high sulfate concentrations can be reduced by gypsum precipitation, removing lower concentrations (below 1200 mg/L) remains a challenge. Therefore, this work sought to investigate the application of ion exchange resins for sulfate sorption. The macroporous type 1 strong base IX resin Purolite A500 was selected for bath and fixed-bed sorption experiments using synthetic sulfate solutions. Equilibrium experiments showed that sulfate loading on the resin can be described by the Langmuir isotherm with a maximum uptake of 59 mg mL-resin(-1). The enthalpy of sorption was determined as +2.83 kJ mol(-1), implying an endothermic physisorption process that occurred with decreasing entropy (-15.5 J mol(-1).K(-1)). Fixed-bed experiments were performed at different bed depths, flow rates, and initial sulfate concentrations. The Miura and Hashimoto model predicted a maximum bed loading of 25-30 g L-bed(-1) and indicated that both film diffusion (3.2 × 10(-3) cm s(-1) to 22.6 × 10(-3) cm s(-1)) and surface diffusion (1.46 × 10(-7) cm(2) s(-1) to 5.64 × 10(-7) cm(2) s(-1)) resistances control the sorption process. It was shown that IX resins are an alternative for the removal of sulfate from mine waters; they ensure very low residual concentrations, particularly in effluents where the sulfate concentration is below the gypsum solubility threshold. PMID:25014887

  19. Production of large quantities of 90Y by ion-exchange chromatography using an organic resin and a chelating agent.

    PubMed

    Castillo, Abmel Xiques; Pérez-Malo, Marylaine; Isaac-Olivé, Keila; Mukhallalati, Heyam; González, Edgar Casanova; Berdeguez, Mirta Torres; Díaz, Néstor Cornejo

    2010-11-01

    The performance of a system composed of an organic cation exchanger (Dowex 50Wx8) and a chelating agent (EDTA) previously described for the successful production of (90)Y via a (90)Sr/(90)Y generator is assessed under dynamic conditions. In an attempt to overcome the established limitation of ion-exchange resins for the separation of subcurie quantities of activity, (90)Y is repeatedly isolated from an 11.8-GBq (320 mCi) (90)Sr cow using a three-column tandem arrangement. The high recovery and radionuclidic purity obtained for (90)Y and the parameters of the separation (time, eluant concentration, pH and flow rate range) strongly suggest that Ci quantities of (90)Y can be handled satisfactorily by the ion-exchange method. No replacement or treatment of the cow, low waste generation and (90)Sr losses less than 0.1% after each run were observed during the present study which, in combination with the low cost of this resin, may result in an attractive alternate method for the production of large quantities of (90)Y. PMID:21055624

  20. Impact of anionic ion exchange resins on NOM fractions: Effect on N-DBPs and C-DBPs precursors.

    PubMed

    Bazri, Mohammad Mahdi; Martijn, Bram; Kroesbergen, Jan; Mohseni, Madjid

    2016-02-01

    The formation potential of carbonaceous and nitrogenous disinfection by-products (C-DBPs, N-DBPs) after ion exchange treatment (IEX) of three different water types in multiple consecutive loading cycles was investigated. Liquid chromatography with organic carbon detector (LC-OCD) was employed to gauge the impact of IEX on different natural organic matter (NOM) fractions and data obtained were used to correlate these changes to DBPs Formation Potential (FP) under chlorination. Humic (-like) substances fractions of NOM were mainly targeted by ion exchange resins (40-67% removal), whereas hydrophilic, non-ionic fractions such as neutrals and building blocks were poorly removed during the treatment (12-33% removal). Application of ion exchange resins removed 13-20% of total carbonaceous DBPs FP and 3-50% of total nitrogenous DBPs FP. Effect of the inorganic nitrogen (i.e., Nitrate) presence on N-DBPs FP was insignificant while the presence of dissolved organic nitrogen (DON) was found to be a key parameter affecting the formation of N-DBPs. DON especially the portion affiliated with humic substances fraction, was reduced effectively (∼77%) as a result of IEX treatment. PMID:26547880

  1. Summary of pilot-scale activities with resorcinol ion exchange resin

    SciTech Connect

    Cicero, C.A.; Bickford, D.F.; Sargent, T.N.; Andrews, M.K.; Bibler, J.P.; Bibler, N.E.; Jantzen, C.M.

    1995-10-02

    The Mixed Waste Focus Area (MWFA) of the Department of Energy (DOE) is currently investigating vitrification technology for treatment of low level mixed wastes (LLMW). They have chartered the Savannah River Technology Center (SRTC) to study vitrification of the wastes through an Office of Technology Development (OTD) Technical Task Plan (TTP). SRTC`s efforts have included crucible-scale studies and pilot scale testing on simulated LLMW sludges, resins, soils, and other solid wastes. Results from the crucible-scale studies have been used as the basis for the pilot-scale demonstrations. As part of the fiscal year (FY) 1995 activities, SRTC performed crucible-scale studies with organic resins. This waste stream was selected because of the large number of DOE sites, as well as commercial industries, that use resins for treatment of liquid wastes. Pilot-scale studies were to be completed in FY 1995, but could not be due to a reduction in funding. Instead, a compilation of pilot-scale tests with organic resins performed under the guidance of SRTC was provided in this report. The studies which will be discussed used a resorcinol- formaldehyde resin loaded with non-radioactive cesium, which was fed with simulated wastewater treatment sludge feed. The first study was performed at the SRTC in the mini-melter, 1/100th scale of the Defense Waste Processing Facility (DWPF) melter, and also involved limited crucible-scale studies to determine the resin loading obtainable. The other study was performed at the DOE/Industrial Center for Vitrification Research (Center) and involved both crucible and pilot-scale testing in the Stir-Melter stirred-melter. Both studies were successful in vitrifying the resin in simulated radioactive sludge and glass additive feeds.

  2. Large Scale Solid Phase Synthesis of Peptide Drugs: Use of Commercial Anion Exchange Resin as Quenching Agent for Removal of Iodine during Disulphide Bond Formation

    PubMed Central

    Reddy, K. M. Bhaskara; Kumari, Y. Bharathi; Mallikharjunasarma, Dokka; Bulliraju, Kamana; Sreelatha, Vanjivaka; Ananda, Kuppanna

    2012-01-01

    The S-acetamidomethyl (Acm) or trityl (Trt) protecting groups are widely used in the chemical synthesis of peptides that contain one or more disulfide bonds. Treatment of peptides containing S-Acm protecting group with iodine results in simultaneous removal of the sulfhydryl protecting group and disulfide formation. However, the excess iodine needs to be quenched or adsorbed as quickly as possible after completion of the disulfide bond formation in order to minimize side reactions that are often associated with the iodination step. We report here a simple method for simultaneous quenching and removal of iodine and isolation of disulphide bridge peptides. The use of excess inexpensive anion exchange resin to the oxidized peptide from the aqueous acetic acid/methanol solution affords quantitative removal of iodine and other color impurities. This improves the resin life time of expensive chromatography media that is used in preparative HPLC column during the purification of peptide using preparative HPLC. Further, it is very useful for the conversion of TFA salt to acetate in situ. It was successfully applied commercially, to the large scale synthesis of various peptides including Desmopressin, Oxytocin, and Octreotide. This new approach offers significant advantages such as more simple utility, minimal side reactions, large scale synthesis of peptide drugs, and greater cost effectiveness. PMID:23118772

  3. Preparation and evaluation of orally disintegrating tablets of taste masked phencynonate HCl using ion-exchange resin.

    PubMed

    Ge, Zhenzhong; Yang, Meiyan; Wang, Yuli; Shan, Li; Gao, Chunsheng

    2015-06-01

    This study was intended to design an orally disintegrating tablet (ODT) formulation that can mask the extremely bitter and metallic taste of phencynonate HCl by novel ion-exchange resins. The drug-resin complexes (DRCs) were prepared and characterized by scanning electron microscopy, X-ray powder diffraction and differential scanning calorimetry. In vitro properties (dissolution, wetting time and disintegration time) and in vivo behavior (disintegration time and taste-masking effect) in healthy volunteers of the prepared ODTs were also investigated. The drug was changed from the crystal structure to the amorphous form in the DRC. Compared with commercial tablets, the in vitro and in vivo disintegration of optimized DRC-loaded ODTs with a drug-resin ratio of 1:1 was greatly improved and better palatability with a low bitterness index (0.33) was obtained. The current DRC-loaded ODT could promise a good way to mask the unpleasant taste of certain drugs and accordingly improve the patient compliance. PMID:24785576

  4. Neopentane and solid acids: direct hydron exchange before cracking.

    PubMed

    Walspurger, Stéphane; Sun, Yinyong; Souna Sido, Abdelkarim Sani; Sommer, Jean

    2006-09-21

    The hydrogen/deuterium exchange reaction of 2,2-dimethylpropane (neopentane) over D(2)O-exchanged zeolites (MOR, FAU, BEA, MFI) using a batch recirculation reactor was studied by means of gas chromatography coupled with mass spectrometer. In the temperature range 473-573 K, H/D exchange proceeds without side reaction such as cracking at short contact times. Indeed the C-H bond has appeared favorably involved in the activation of neopentane compared to the less accessible C-C bond. The transition state allowing hydron exchange is most likely a carbonium species (pentacoordinated carbon) as in the case of the H/D exchange between methane and solid acid. The activation energies of the H/D exchange between neopentane and zeolites are the same for all zeolites indicating a common carbonium ion type transition state. On the basis of previous results in the case of the exchange between methane and liquid superacids, the deuterium exchange rates in neopentane were tentatively related to the acidity of the solids. However the order of activity MOR > MFI > BEA > FAU seems to be related to the size of the pores, which may suggest the involvement of a confinement effect in the zeolites cavities. Moreover we found that H/D exchange takes also place between neopentane and deuterated sulfated zirconia (SZ) emphasizing its strong acidity. PMID:16970460

  5. On the real performance of cation exchange resins in wastewater treatment under conditions of cation competition: the case of heavy metal pollution.

    PubMed

    Prelot, Benedicte; Ayed, Imen; Marchandeau, Franck; Zajac, Jerzy

    2014-01-01

    Sorption performance of cation-exchange resins Amberlite® IRN77 and Amberlite™ IRN9652 toward Cs(I) and Sr(II) has been tested in single-component aqueous solutions and simulated waste effluents containing other monovalent (Effluent 1) or divalent (Effluent 2) metal cations, as well as nitrate, borate, or carbonate anions. The individual sorption isotherms of each main component were measured by the solution depletion method. The differential molar enthalpy changes accompanying the ion-exchange between Cs+ or Sr2+ ions and protons at the resin surface from single-component nitrate solutions were measured by isothermal titration calorimetry and they showed a higher specificity of the two resins toward cesium. Compared to the retention limits of both resins under such idealized conditions, an important depression in the maximum adsorption capacity toward each main component was observed in multication systems. The overall effect of ion exchange process appeared to be an unpredictable outcome of the individual sorption capacities of the two resins toward various cations as a function of the cation charge, size, and concentration. The cesium retention capacity of the resins was diminished to about 25% of the "ideal" value in Effluent 1 and 50% in Effluent 2; a further decrease to about 15% was observed upon concomitant strontium addition. The uptake of strontium by the resins was found to be less sensitive to the addition of other metal components: the greatest decrease in the amount adsorbed was 60% of the ideal value in the two effluents for Amberlite® IRN77 and 75% for Amberlite™ IRN9652. It was therefore demonstrated that any performance tests carried out under idealized conditions should be exploited with much caution to predict the real performance of cation exchange resins under conditions of cation competition. PMID:24728575

  6. Breadboard wash water renovation system. [using ferric chloride and ion exchange resins to remove soap and dissolved salts

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A total wash water renovation system concept was developed for removing objectionable materials from spacecraft wash water in order to make the water reusable. The breadboard model system described provides for pretreatment with ferric chloride to remove soap by chemical precipitation, carbon adsorption to remove trace dissolved organics, and ion exchange for removal of dissolved salts. The entire system was put into continuous operation and carefully monitored to assess overall efficiency and equipment maintenance problems that could be expected in actual use. In addition, the capacity of the carbon adsorbers and the ion-exchange resin was calculated and taken into consideration in the final evaluation of the system adequacy. The product water produced was well within the Tentative Wash Water Standards with regard to total organic carbon, conductivity, urea content, sodium chloride content, color, odor, and clarity.

  7. Shear bond strength of resin cement to an acid etched and a laser irradiated ceramic surface

    PubMed Central

    Motro, Pelin Fatma Karagoz; Yurdaguven, Haktan

    2013-01-01

    PURPOSE To evaluate the effects of hydrofluoric acid etching and Er,Cr:YSGG laser irradiation on the shear bond strength of resin cement to lithium disilicate ceramic. MATERIALS AND METHODS Fifty-five ceramic blocks (5 mm × 5 mm × 2 mm) were fabricated and embedded in acrylic resin. Their surfaces were finished with 1000-grit silicon carbide paper. The blocks were assigned to five groups: 1) 9.5% hydrofluoric-acid etching for 60 s; 2-4), 1.5-, 2.5-, and 6-W Er,Cr:YSGG laser applications for 60 seconds, respectively; and 5) no treatment (control). One specimen from each group was examined using scanning electron microscopy. Ceramic primer (Rely X ceramic primer) and adhesive (Adper Single Bond) were applied to the ceramic surfaces, followed by resin cement to bond the composite cylinders, and light curing. Bonded specimens were stored in distilled water at 37℃ for 24 hours. Shear bond strengths were determined by a universal testing machine at 1 mm/min crosshead speed. Data were analyzed using Kruskal-Wallis and Mann-Whitney U-tests (α=0.05). RESULTS Adhesion was significantly stronger in Group 2 (3.88 ± 1.94 MPa) and Group 3 (3.65 ± 1.87 MPa) than in Control group (1.95 ± 1.06 MPa), in which bonding values were lowest (P<.01). No significant difference was observed between Group 4 (3.59 ± 1.19 MPa) and Control group. Shear bond strength was highest in Group 1 (8.42 ± 1.86 MPa; P<.01). CONCLUSION Er,Cr:YSGG laser irradiation at 1.5 and 2.5 W increased shear bond strengths between ceramic and resin cement compared with untreated ceramic surfaces. Irradiation at 6 W may not be an efficient ceramic surface treatment technique. PMID:23755333

  8. Minimization of short-term low-pressure membrane fouling using a magnetic ion exchange (MIEX(®)) resin.

    PubMed

    Jutaporn, Panitan; Singer, Philip C; Cory, Rose M; Coronell, Orlando

    2016-07-01

    Two challenges to low-pressure membrane (LPM) filtration are limited rejection of dissolved organic matter (DOM) and membrane fouling by DOM. The magnetic ion exchange resin MIEX(®) (Ixom Watercare Inc.) has been demonstrated to remove substantial amounts of DOM from many source waters, suggesting that MIEX can both reduce DOM content in membrane feed waters and minimize LPM fouling. We tested the effect of MIEX pretreatment on the reduction of short-term LPM fouling potential using feed waters varying in DOM concentration and composition. Four natural and two synthetic waters were studied and a polyvinylidene fluoride (PVDF) hollow-fiber ultrafiltration membrane was used in membrane fouling tests. To evaluate whether MIEX removes the fractions of DOM that cause LPM fouling, the DOM in raw, MIEX-treated, and membrane feed and backwash waters was characterized in terms of DOM concentration and composition. Results showed that: (i) the efficacy of MIEX to reduce LPM fouling varies broadly with source water; (ii) MIEX preferentially removes terrestrial DOM over microbial DOM; (iii) microbial DOM is a more important contributor to LPM fouling than terrestrial DOM, relative to their respective concentrations in source waters; and (iv) the fluorescence intensity of microbial DOM in source waters can be used as a quantitative indicator of the ability of MIEX to reduce their membrane fouling potential. Thus, when ion exchange resin processes are used for DOM removal towards membrane fouling reduction, it is advisable to use a resin that has been designed to effectively remove microbial DOM. PMID:27107140

  9. [Enhanced Performance of Rolled Membrane Electrode Assembly by Adding Cation Exchange Resin to Anode in Microbial Fuel Cells].

    PubMed

    Mei, Zhuo; Zhang, Zhe; Wang, Xin

    2015-11-01

    The membrane electrode assembly (MEA) with an anode-membrane-cathode structure ban reduce the distance between anode and cathode to improve the power of microbial fuel cells (MFCs). Here in order to further promote the performance of MFCs, a novel MEA was constructed by rolling-press method without noble metal material, and the Ohmic resistance decreased to 3-5 Ω. The maximum power density was 446 mW x m(-2) when acetate was used as the substrate. Solid spheres (like polystyrene balls and glass microspheres) were added into anode to enhance the transportation of electrolyte to cathode, resulting in a 10% increase in power density by producing macropores on and in the anode during rolling process. Cation exchange resin was added to accelerate the transportation of proton through the anode so that the power density further increased to 543 mW x m(-2). Meanwhile, the stability of cell voltage and Coulomb efficiency of MFC were both enhanced after the addition of cation exchange resin. PMID:26911023

  10. Leach studies on cement-solidified ion exchange resins from decontamination processes at operating nuclear power stations

    SciTech Connect

    McIsaac, C.V.; Akers, D.W.; McConnell, J.W.; Morcos, N.

    1992-08-01

    The effects of varying pH and leachant compositions on the physical stability and leachability of radionuclides and chelating agents were determined for cement-solidified decontamination ion-exchange resin wastes collected from two operating commercial light water reactors. Small scale waste-form specimens were collected during waste solidifications performed at the Brunswick Steam Electric Plant Unit 1 and at the James A. FitzPatrick Nuclear Power Station. The collected specimens were leach tested, and their compressive strength was measured in accordance with the Nuclear Regulatory Commission`s ``Technical Position on Waste Form`` (Revision 1), from the Low-Level Waste Management Branch. Leachates from these studies were analyzed for radionuclides, selected transition metals, and chelating agents to assess the leachability of these waste form constituents. Leachants used for the study were deionized water, simulated seawater, and groundwater compositions similar to those found at Barnwell, South Carolina and Hanford, Washington. Results of this study indicate that initial leachant pH does not affect leachate pH or releases from cement-solidified decontamination ion-exchange resin waste forms. However, differences in leachant composition and the presence of chelating agents may affect the releases of radionuclides and chelating agents. In addition, results from this study indicate that the cumulative releases of radionuclides and chelating agents observed for forms that disintegrated were similar to those for forms that maintained their general physical integrity.

  11. Leach studies on cement-solidified ion exchange resins from decontamination processes at operating nuclear power stations

    SciTech Connect

    McIsaac, C.V.; Akers, D.W.; McConnell, J.W.; Morcos, N.

    1992-01-01

    The effects of varying pH and leachant compositions on the physical stability and leachability of radionuclides and chelating agents were determined for cement-solidified decontamination ion-exchange resin wastes collected from two operating commercial light water reactors. Small scale waste-form specimens were collected during waste solidifications performed at the Brunswick Steam Electric Plant Unit 1 and at the James A. FitzPatrick Nuclear Power Station. The collected specimens were leach tested, and their compressive strength was measured in accordance with the Nuclear Regulatory Commission's Technical Position on Waste Form'' (Revision 1), from the Low-Level Waste Management Branch. Leachates from these studies were analyzed for radionuclides, selected transition metals, and chelating agents to assess the leachability of these waste form constituents. Leachants used for the study were deionized water, simulated seawater, and groundwater compositions similar to those found at Barnwell, South Carolina and Hanford, Washington. Results of this study indicate that initial leachant pH does not affect leachate pH or releases from cement-solidified decontamination ion-exchange resin waste forms. However, differences in leachant composition and the presence of chelating agents may affect the releases of radionuclides and chelating agents. In addition, results from this study indicate that the cumulative releases of radionuclides and chelating agents observed for forms that disintegrated were similar to those for forms that maintained their general physical integrity.

  12. AUTOMATIC EXCHANGE RESIN PILOT PLANT FOR REMOVAL OF TEXTILE DYE WASTES

    EPA Science Inventory

    The report gives results of an investigation of the use of adsorption resins to remove colored dyes from textile dyeing wastewaters, using an automated benchscale pilot unit. This could make possible the reuse of the treated wastewaters in subsequent dyeing operations. The scale ...

  13. Potential heat exchange fluids for use in sulfuric acid vaporizers

    NASA Technical Reports Server (NTRS)

    Lawson, D. D.; Petersen, G. R.

    1979-01-01

    A series of perhalocarbons are proposed as candidate heat exchange fluids for service in thermochemical cycles for hydrogen production that involve direct contact of the fluid with sulfuric acid and vaporization of the acid. The required chemical and physical criteria of the liquids are described and the results of some preliminary high temperature test data are presented.

  14. Phosphoric acid esters cannot replace polyvinylphosphonic acid as phosphoprotein analogs in biomimetic remineralization of resin-bonded dentin.

    PubMed

    Mai, Sui; Kim, Young Kyung; Toledano, Manuel; Breschi, Lorenzo; Ling, Jun Qi; Pashley, David H; Tay, Franklin R

    2009-10-01

    Polyvinylphosphonic acid (PVPA), a biomimetic analog of phosphoproteins, is crucial for recruiting polyacrylic acid (PAA)-stabilized amorphous calcium phosphate nanoprecursors during biomimetic remineralization of dentin collagen matrices. This study tested the null hypothesis that phosphoric acid esters of methacrylates in dentin adhesives cannot replace PVPA during bimimetic remineralization of resin-dentin interfaces. Human dentin specimens were bonded with: (I) XP Bond, an etch-and-rinse adhesive using moist bonding; (II) XP Bond using dry bonding; (III) Adper Prompt L-Pop, a self-etching adhesive. The control medium contained only set Portland cement and a simulated body fluid (SBF) without any biomimetic analog. Two experimental Portland cement/SBF remineralization media were evaluated: the first contained PAA as the sole biomimetic analog, the second contained PAA and PVPA as dual biomimetic analogs. No remineralization of the resin-dentin interfaces could be identified from specimens immersed in the control medium. After 2-4 months in the first experimental medium, specimens exhibited either no remineralization or large crystal formation within hybrid layers. Only specimens immersed in the second remineralization medium produced nanocrystals that accounted for intrafibrillar remineralization within hybrid layers. The null hypothesis could not be rejected; phosphoric acid esters in dentin adhesives cannot replace PVPA during biomimetic remineralization of adhesive-bonded dentin. PMID:19481792

  15. Enhancement of uranium loading on ion exchange resin from carbonate leachate by lowering pH from 8 to 6. 5

    SciTech Connect

    Otto, J.B.

    1984-06-01

    This paper discusses a laboratory study that shows the saturation ion-exchange loading of uranium from carbonate leachate can be doubled by lowering the pH of the leachate from 8 to 6.5. Small column and batch resin loading tests using Dowex 21K ion-exchange resin are described. The leachate contained 3,300 ppm chloride, 2,400 ppm carbonate, and 220 ppm U/sub 3/O/sub 8/, and had a pH of 8. Even at this rather mild salinity the saturation ion-exchange loading was found to be only about 3 to 4 lbm U/sub 3/O/sub 8//cu ft resin (48 to 64 g/dm/sup 3/) because of competition with the chloride ion for exchange sites on the anionic resin. Lowering the pH of the leachate to 6.5 by CO/sub 2/ gas addition, however, increased loading to about 8 lbm U/sub 3/O/sub 8//cu ft resin (128 g/dm/sup 3/). The pH-lowering effect worked especially well at relatively high salt concentration. The same leachate, with its chloride content increased to 12,000 ppm, loaded only 0.5 lbm U/sub 3/O/sub 8//cu ft resin (8 g/dm/sup 3/) at pH 8 but loaded 5.5 lbm U/sub 3/O/sub 8//cu ft resin (88 g/dm/sup 3/) at pH 6.5.

  16. Thermal and Mechanical Characteristics of Polymer Composites Based on Epoxy Resin, Aluminium Nanopowders and Boric Acid

    NASA Astrophysics Data System (ADS)

    Nazarenko, O. B.; Melnikova, T. V.; Visakh, P. M.

    2016-01-01

    The epoxy polymers are characterized by low thermal stability and high flammability. Nanoparticles are considered to be effective fillers of polymer composites for improving their thermal and functional properties. In this work, the epoxy composites were prepared using epoxy resin ED-20, polyethylene polyamine as a hardener, aluminum nanopowder and boric acid fine powder as flame-retardant filler. The thermal characteristics of the obtained samples were studied using thermogravimetric analysis and differential scanning calorimetry. The mechanical characteristics of epoxy composites were also studied. It was found that an addition of all fillers enhances the thermal stability and mechanical characteristics of the epoxy composites. The best thermal stability showed the epoxy composite filled with boric acid. The highest flexural properties showed the epoxy composite based on the combination of boric acid and aluminum nanopowder.

  17. Radioluminescence of polyester resin modified with acrylic acid and its salts

    NASA Astrophysics Data System (ADS)

    Szalińska, H.; Wypych, M.; Pietrzak, M.; Szadkowska-Nicze, M.

    Polimal-109 polyester resin and its compounds containing acrylic acid and its salts such as: sodium, potassium, magnesium, calcium, barium, iron, cobalt, copper and manganese acrylates were studied by the radioluminescence method, including isothermal luminescence (ITL) at a radiation temperature of 77 K, thermoluminescence (RTL) and spectral distributions of isothermal luminescence. Measurements of optical absorption at 77 K before and after irradiation of the investigated samples were also carried out. The results obtained have shown that metal ions play a significant part in the processes taking place in the polyester matrix under the influence of γ 60Co radiation.

  18. A ten liter stacked microbial desalination cell packed with mixed ion-exchange resins for secondary effluent desalination.

    PubMed

    Zuo, Kuichang; Cai, Jiaxiang; Liang, Shuai; Wu, Shijia; Zhang, Changyong; Liang, Peng; Huang, Xia

    2014-08-19

    The architecture and performance of microbial desalination cell (MDC) have been significantly improved in the past few years. However, the application of MDC is still limited in a scope of small-scale (milliliter) reactors and high-salinity-water desalination. In this study, a large-scale (>10 L) stacked MDC packed with mixed ion-exchange resins was fabricated and operated in the batch mode with a salt concentration of 0.5 g/L NaCl, a typical level of domestic wastewater. With circulation flow rate of 80 mL/min, the stacked resin-packed MDC (SR-MDC) achieved a desalination efficiency of 95.8% and a final effluent concentration of 0.02 g/L in 12 h, which is comparable with the effluent quality of reverse osmosis in terms of salinity. Moreover, the SR-MDC kept a stable desalination performance (>93%) when concentrate volume decreased from 2.4 to 0.1 L (diluate/concentrate volume ratio increased from 1:1 to 1:0.04), where only 0.875 L of nonfresh water was consumed to desalinate 1 L of saline water. In addition, the SR-MDC achieved a considerable desalination rate (95.4 mg/h), suggesting a promising application for secondary effluent desalination through deriving biochemical electricity from wastewater. PMID:25075560

  19. Glucosinolates and derived products in cruciferous vegetables: total glucosinolates by retention on anion exchange resin and enzymatic hydrolysis to measure released glucose.

    PubMed

    VanEtten, C H; Daxenbichler, M E

    1977-07-01

    Details are given for determining total glucosinolates in Cruciferae plants by a procedure measuring released glucose. The glucosinolates are separated from about 90% of other material in the plant extract by adsorption on an anion exchange resin. Then, by a selective thioglucosidase hydrolysis of the glucosinolates retained on the exchange resin, the glucose and aglucons are separated from other substances retained by the resin. Glucose is released into an aqueous medium and is equivalent to the total glucosinolates. The aglucons formed by the hydrolysis are extracted into methylene chloride and determined by gas-liquid chromatography. Based on 29 determinations of the glucose from sinigrin, analyzed under different conditions, accuracy of the total glucosinolate determination was 94.8 +/- 7.3%. The coefficient of variation, determined by duplicate analyses on extracts from 58 cabbage samples, was 4.6%. PMID:893313

  20. UREA/ammonium ion removal system for the orbiting frog otolith experiment. [ion exchange resins for water treatment during space missions

    NASA Technical Reports Server (NTRS)

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

    1976-01-01

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

  1. Citric Acid Enhanced Copper Removal by a Novel Multi-amines Decorated Resin

    NASA Astrophysics Data System (ADS)

    Ling, Chen; Liu, Fuqiang; Pei, Zhiguo; Zhang, Xiaopeng; Wei, Mengmeng; Zhang, Yanhong; Zheng, Lirong; Zhang, Jing; Li, Aimin; Xing, Baoshan

    2015-05-01

    Cu removal by a novel multi-amines decorated resin (PAMD) from wastewater in the absence or presence of citric acid (CA) was examined. Adsorption capacity of Cu onto PAMD markedly increased by 186% to 5.07 mmol/g in the presence of CA, up to 7 times of that onto four commercial resins under the same conditions. Preloaded and kinetic studies demonstrated adsorption of [Cu-CA] complex instead of CA site-bridging and variations of adsorbate species were qualitatively illustrated. The interaction configuration was further studied with ESI-MS, FTIR, XPS and XANES characterizations. The large enhancement of Cu adsorption in Cu-CA bi-solutes systems was attributed to mechanism change from single-site to dual-sites interaction in which cationic or neutral Cu species (Cu2+ and CuHL0) coordinated with neutral amine sites and anionic complex species (CuL- and Cu2L22-) directly interacted with protonated amine sites via electrostatic attraction, and the ratio of the two interactions was approximately 0.5 for the equimolar bi-solutes system. Moreover, commonly coexisting ions in wastewaters had no obvious effect on the superior performance of PAMD. Also, Cu and CA could be recovered completely with HCl. Therefore, PAMD has a great potential to efficiently remove heavy metal ions from wastewaters in the presence of organic acids.

  2. Self-assembly of resins and asphaltenes facilitates asphaltene dissolution by an organic acid.

    PubMed

    Hashmi, Sara M; Firoozabadi, Abbas

    2013-03-15

    Asphaltene precipitation occurs in petroleum fluids under certain unfavorable conditions, but can be controlled by tuning composition. Aromatic solvents in large quantities can prevent precipitation entirely and can dissolve already precipitated asphaltenes. Some polymeric surfactants can dissolve asphaltenes when added at much lower concentrations than required by aromatic solvents. Other dispersants can truncate asphaltene precipitation at the sub-micron length scale, creating stable colloidal asphaltene dispersants. One particular asphaltene dispersant, dodecylbenzene sulfonic acid (DBSA), can do both, namely: (1) stabilize asphaltene colloids and (2) dissolve asphaltenes to the molecular scale. Acid-base interactions are responsible for the efficiency of DBSA in dissolving asphaltenes compared to aromatic solvents. However, many details remain to be quantified regarding the action of DBSA on asphaltenes, including the effect of petroleum fluid composition. For instance, resins, naturally amphiphilic components of petroleum fluids, can associate with asphaltenes, but it is unknown whether they cooperate or compete with DBSA. Similarly, the presence of metals is known to hinder asphaltene dissolution by DBSA, but its effect on colloidal asphaltene stabilization has yet to be considered. We introduce the concepts of cooperativity and competition between petroleum fluid components and DBSA in stabilizing and dissolving asphaltenes. Notably, we find that resins cooperatively interact with DBSA in dissolving asphaltenes. We use UV-vis spectroscopy to investigate the interactions responsible for the phase transitions between unstable suspensions, stable suspensions, and molecular solutions of asphaltenes. PMID:23351475

  3. Citric Acid Enhanced Copper Removal by a Novel Multi-amines Decorated Resin

    PubMed Central

    Ling, Chen; Liu, Fuqiang; Pei, Zhiguo; Zhang, Xiaopeng; Wei, Mengmeng; Zhang, Yanhong; Zheng, Lirong; Zhang, Jing; Li, Aimin; Xing, Baoshan

    2015-01-01

    Cu removal by a novel multi-amines decorated resin (PAMD) from wastewater in the absence or presence of citric acid (CA) was examined. Adsorption capacity of Cu onto PAMD markedly increased by 186% to 5.07 mmol/g in the presence of CA, up to 7 times of that onto four commercial resins under the same conditions. Preloaded and kinetic studies demonstrated adsorption of [Cu-CA] complex instead of CA site-bridging and variations of adsorbate species were qualitatively illustrated. The interaction configuration was further studied with ESI-MS, FTIR, XPS and XANES characterizations. The large enhancement of Cu adsorption in Cu-CA bi-solutes systems was attributed to mechanism change from single-site to dual-sites interaction in which cationic or neutral Cu species (Cu2+ and CuHL0) coordinated with neutral amine sites and anionic complex species (CuL− and Cu2L22−) directly interacted with protonated amine sites via electrostatic attraction, and the ratio of the two interactions was approximately 0.5 for the equimolar bi-solutes system. Moreover, commonly coexisting ions in wastewaters had no obvious effect on the superior performance of PAMD. Also, Cu and CA could be recovered completely with HCl. Therefore, PAMD has a great potential to efficiently remove heavy metal ions from wastewaters in the presence of organic acids. PMID:25962970

  4. Surface roughness of flowable resin composites eroded by acidic and alcoholic drinks

    PubMed Central

    Poggio, Claudio; Dagna, Alberto; Chiesa, Marco; Colombo, Marco; Scribante, Andrea

    2012-01-01

    Aim: The aim of this study is to evaluate the surface roughness of four flowable resin composites following exposure to acidic and alcoholic drinks. Materials and Methods: SureFil SDR flow, TetricEvoFlow, Esthet-X Flow and Amaris Flow HT samples were immersed in artificial saliva, Coca Cola and Chivas Regal Whisky. Each specimen was examined using a Leica DCM 3D microscope: Arithmetical mean height of the surface profiles was measured (Sa). Results: Kruskal-Wallis test showed significant differences among various groups (P<0,001). Mann Whitney test was applied and control groups showed significantly lower Sa values than other groups (P=0,008). Coca Cola groups showed highest Sa values (P<0,021). No significant differences (P=0,14) in surface texture were found among the specimens of the different materials. No significant differences were found among TetricEvoFlow, Esthet-X Flow and Amaris Flow under control conditions nor after Coca Cola application. Under control condition and after Coca Cola application SureFil SDR flow showed significantly higher Sa values. Moreover, after whisky application Amaris Flow showed significantly lower Sa values then the other three groups that showed no significant differences among them. Conclusions: Acidic and alcoholic drinks eroded the surface roughness of all evaluated flowable resin composites. PMID:22557811

  5. Application of electrolyzed acid water to sterilization of denture base part 1. Examination of sterilization effects on resin plate.

    PubMed

    Nagamatsu, Y; Tajima, K; Kakigawa, H; Kozono, Y

    2001-06-01

    Bactericidal activities of electrolyzed strong and weak acid waters for acrylic denture base resin were evaluated in order to discuss the applicability of these waters for sterilization of denture base. Only 1-minute immersion in the electrolyzed strong or weak acid water could completely eliminate the attached bacteria, Staphylococcus aureus 209P, on the resin plate. When the resin was relined with tissue conditioner, 5-minute immersion or 1- to 2-minute ultrasonic cleaning reduced the number of the bacteria from 10(5)/cm2 level to 10(1)/cm2 and no surviving bacteria could be detected after 10-minute treatment. These findings suggest that both the electrolyzed strong and weak acid waters are well applicable to the disinfectant for acrylic denture base showing excellent bactericidal activities in a significantly shorter treatment as compared with the conventional denture cleaning. PMID:11523978

  6. Immobilized humic substances on an anion exchange resin and their role on the redox biotransformation of contaminants.

    PubMed

    Cervantes, Francisco J; Gonzalez-Estrella, Jorge; Márquez, Arturo; Alvarez, Luis H; Arriaga, Sonia

    2011-01-01

    A novel technique to immobilize humic substances (HS) on an anion exchange resin is presented. Immobilized HS were demonstrated as an effective solid-phase redox mediator (RM) during the reductive biotransformation of carbon tetrachloride (CT) and the azo model compound, Reactive Red 2 (RR2). Immobilized HS increased ∼4-fold the extent of CT reduction to chloroform by a humus-reducing consortium in comparison to incubations lacking HS. Immobilized HS also increased 2-fold the second-order rate constant of decolorization of RR2 as compared with sludge incubations lacking HS. To our knowledge, the present study constitutes the first demonstration of immobilized HS serving as an effective solid-phase RM during the reductive biotransformation of priority contaminants. The immobilizing technique developed could be appropriate for enhancing the redox biotransformation of recalcitrant pollutants in anaerobic wastewater treatment systems. PMID:20801024

  7. Effects of pH and Competing Anions on the Solution Speciation of Arsenic by Ion Exchange Resins

    SciTech Connect

    Impellitteri, Christopher A.; Ryan, JAmes A.; Al-Abed, Souhail R.; Scheckel, Kirk G.; Randall, Paul M.; Richardson, Collin A.

    2003-03-26

    Anion-exchange resins (AER) are used to differentiate As(V) and As(III) by retaining As(V) and allowing As(III) to pass through. AERs allow rapid speciation of As in the field which precludes the effects of sample preservation on As speciation. Aqueous environmental samples contain anions that may interfere with the speciation of As. This study compares the speciation of As by two commercially available AERs. A silica-based AER was selected for further study. As(V) and As(III) were passed through the AER in the presence of NO3 -, SO4 2-, HPO4 2-, Cl- and HCO3 - at pH 4, 6 and 8. Recoveries of As species in mixed systems range between 90 to 100%. Breakthrough curves for As(V) are presented which allow calculation of loading rates. HPO4 2- has the greatest effect on the speciation of As by AER.

  8. Effect of nano-silica spheres template on CO2 capture of exchange resin-based nanoporous carbons.

    PubMed

    Meng, Long-Yue; Park, Soo-Jin

    2013-01-01

    In this work, a nanoporous carbon-based adsorbent with a higher specific surface area was directly prepared from polystyrene-based cation exchange resin (PCER) by carbonization of a mixture of nano-silica spheres. The silica/PCER composites were carbonized at 1173 K with different silica/PCER ratios. The effects of nano-silica spheres content on the pore structures of nanoporous carbons were investigated by N2 full isotherms. The CO2 capture capacity was measured by CO2 isothermal adsorption at 298 K and 1 bar. From the results, it was found that the nano-silica spheres/PCER ratio had a major influence on the CO2 capture capacity and the textural properties of the prepared nanoporous carbons. The specific surface area and total pore volume, as well as the pore size of the nanoporous carbons increased with increasing silica/PCER ratio. PMID:23646745

  9. Conversion of ion-exchange resins, catalysts and sludges to glass with optional noble metal recovery using the GMODS process

    SciTech Connect

    Forsberg, C.W.; Beahm, E.C.

    1996-11-01

    Chemical processing and cleanup of waste streams (air and water) typically result in products, clean air, clean water, and concentrated hazardous residues (ion exchange resins, catalysts, sludges, etc.). Typically, these streams contain significant quantities of complex organics. For disposal, it is desirable to destroy the organics and immobilize any heavy metals or radioactive components into stable waste forms. If there are noble metals in the residues, it is desirable to recover these for reuse. The Glass Material Oxidation and Dissolution System (GMODS) is a new process that directly converts radioactive and hazardous chemical wastes to borosilicate glass. GMODS oxidizes organics with the residue converted to glass; converts metals, ceramics, and amorphous solids to glass; converts halides (eg chlorides) to borosilicate glass and a secondary sodium halide stream; and recovers noble metals. GMODS has been demonstrated on a small laboratory scale (hundreds of grams), and the equipment needed for larger masses has been identified.

  10. Direct injection analysis of fatty and resin acids in papermaking process waters by HPLC/MS.

    PubMed

    Valto, Piia; Knuutinen, Juha; Alén, Raimo

    2011-04-01

    A novel HPLC-atmospheric pressure chemical ionization/MS (HPLC-APCI/MS) method was developed for the rapid analysis of selected fatty and resin acids typically present in papermaking process waters. A mixture of palmitic, stearic, oleic, linolenic, and dehydroabietic acids was separated by a commercial HPLC column (a modified stationary C(18) phase) using gradient elution with methanol/0.15% formic acid (pH 2.5) as a mobile phase. The internal standard (myristic acid) method was used to calculate the correlation coefficients and in the quantitation of the results. In the thorough quality parameters measurement, a mixture of these model acids in aqueous media as well as in six different paper machine process waters was quantitatively determined. The measured quality parameters, such as selectivity, linearity, precision, and accuracy, clearly indicated that, compared with traditional gas chromatographic techniques, the simple method developed provided a faster chromatographic analysis with almost real-time monitoring of these acids. PMID:21360668

  11. Identification of dehydroabietc acid from Boswellia thurifera resin as a positive GABAA receptor modulator.

    PubMed

    Rueda, Diana C; Raith, Melanie; De Mieri, Maria; Schöffmann, Angela; Hering, Steffen; Hamburger, Matthias

    2014-12-01

    In a two-microelectrode voltage clamp assay with Xenopus laevis oocytes, a petroleum ether extract (100 μg/mL) of the resin of Boswellia thurifera (Burseraceae) potentiated GABA-induced chloride currents (IGABA) through receptors of the subtype α₁β₂γ₂s by 319.8% ± 79.8%. With the aid of HPLC-based activity profiling, three known terpenoids, dehydroabietic acid (1), incensole (2), and AKBA (3), were identified in the active fractions of the extract. Structure elucidation was achieved by means of HR-MS and microprobe 1D/2D NMR spectroscopy. Compound 1 induced significant receptor modulation in the oocyte assay, with a maximal potentiation of IGABA of 397.5% ± 34.0%, and EC₅₀ of 8.7 μM ± 1.3 μM. This is the first report of dehydroabietic acid as a positive GABAA receptor modulator. PMID:25200370

  12. Antibacterial and Biofilm-Disrupting Coatings from Resin Acid-Derived Materials.

    PubMed

    Ganewatta, Mitra S; Miller, Kristen P; Singleton, S Parker; Mehrpouya-Bahrami, Pegah; Chen, Yung P; Yan, Yi; Nagarkatti, Mitzi; Nagarkatti, Prakash; Decho, Alan W; Tang, Chuanbing

    2015-10-12

    We report antibacterial, antibiofilm, and biocompatible properties of surface-immobilized, quaternary ammonium-containing, resin acid-derived compounds and polycations that are known to be efficient antimicrobial agents with minimum toxicities to mammalian cells. Surface immobilization was carried out by the employment of two robust, efficient chemical methods: Copper-catalyzed azide-alkyne 1,3-dipolar cycloaddition click reaction, and surface-initiated atom transfer radical polymerization. Antibacterial and antibiofilm activities against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli were strong. Hemolysis assays and the growth of human dermal fibroblasts on the modified surfaces evidenced their biocompatibility. We demonstrate that the grafting of quaternary ammonium-decorated abietic acid compounds and polymers from surfaces enables the incorporation of renewable biomass in an effective manner to combat bacteria and biofilm formation in biomedical applications. PMID:26324023

  13. Study the adsorption of sulfates by high cross-linked polystyrene divinylbenzene anion-exchange resin

    NASA Astrophysics Data System (ADS)

    Fathy, Mahmoud; Moghny, Th. Abdel; Awadallah, Ahmed E.; El-Bellihi, Abdel-Hameed A.-A.

    2014-11-01

    In response to rising concerns about the effect of sulfate on water quality, human health, and agriculture, many jurisdictions around the world are imposing tighter regulations for sulfate discharge. This is driving the need for environmental compliance in industries like mining, metal processing, pulp and paper, sewage treatment, and chemical manufacturing. The sulfate removal from synthetic water by high cross-linked polystyrene divinylbenzene resin was studied at batch experiments in this study. The effect of pH, contact time, sulfates concentration, and adsorbent dose on the sulfate sequestration was investigated. The optimum conditions were studied on Saline water as a case study. The results showed that with increasing of the absorbent amount; contact time, and pH improve the efficiency of sulfate removal. The maximum sulfates uptake was obtained in pH and contact time 3.0 and 120 min, respectively. Also, with increasing initial concentration of sulfates in water, the efficiency of sulfate removal decreased. The obtained results in this study were matched with Freundlich isotherm and pseudo-second-order kinetic. The maximum adsorption capacity (Qm) and constant rate were found 0.318 (mg/g) and 0.21 (mg/g.min), respectively. This study also showed that in the optimum conditions, the sulfate removal efficiency from Saline water by 0.1 mg/L sulfates was 65.64 %. Eventually, high cross-linked polystyrene divinylbenzene resin is recommended as a suitable and low cost absorbent to sulfate removal from aqueous solutions.

  14. Technology transfer: Ion exchange resins for Technetium-99 removal from X-705 raffinates

    SciTech Connect

    Deacon, L.E.; Greiner, M.J.

    1982-12-03

    An ion exchange process will be used at Portsmouth to remove Technetium-99 from uranium recovery waste solutions (raffinates). Subsequent treatment will then remove nitrates from the raffinates by a biodenitrification process prior to discharge to receiving streams to meet environmental standards for liquid wastes. Ion exchange process parameters affecting safe and efficient raffinate treatment have been examined in the laboratory, and results are described in this report. 4 refs., 3 figs., 6 tabs.

  15. Influence of ozone and paracetic acid disinfection on adhesion of resilient liners to acrylic resin

    PubMed Central

    2016-01-01

    PURPOSE The aim of this study was to evaluate the effect of paracetic acid (PAA) and ozone disinfection on the tensile bond strength (TBS) of silicone-based resilient liners to acrylic resins. MATERIALS AND METHODS One hundred and twenty dumbbell shaped heat-polymerized acrylic resins were prepared. From the mid segment of the specimens, 3 mm of acrylic were grinded off and separated parts were reattached by resilient liners. The specimens were divided into 2 control (control1, control7) and 4 test groups of PAA and ozone disinfection (PAA1, PAA7, ozone1 and ozone7; n=10). While control groups were immersed in distilled water for 10 min (control1) and 7 days (control7), test groups were subjected to PAA (16 g/L) or ozone rich water (4 mg/L) for 1 cycle (10 min for PAA and 60 min for ozone) per day for 7 days prior to tensile tests. Measurements of the TBS were analyzed using 3-way ANOVA and Tukey's HSD test. RESULTS Adhesive strength of Mollosil decreased significantly by application of ozone disinfection. PAA disinfection had no negative effect on the TBS values of Mollosil and Molloplast B to acrylic resin. Single application of ozone disinfection did not have any negative effect on TBS values of Molloplast B, but prolonged exposure to ozone decreased its adhesive strength. CONCLUSION The adhesion of resilient liners to acrylic was not adversely affected by PAA disinfection. Immersion in ozonated water significantly decreased TBS of Mollosil. Prolonged exposure to ozone negatively affects adhesion of Molloplast B to denture base materials. PMID:27555898

  16. Iodine adsorption on ion-exchange resins and activated carbons: batch testing

    SciTech Connect

    Parker, Kent E.; Golovich, Elizabeth C.; Wellman, Dawn M.

    2014-09-30

    Iodine sorption onto seven resins and six carbon materials was evaluated using water from well 299-W19-36 on the Hanford Site. These materials were tested using a range of solution-to-solid ratios. The test results are as follows. The efficacy of the resin and granular activated carbon materials was less than predicted based on manufacturers’ performance data. It is hypothesized that this is due to the differences in speciation previously determined for Hanford groundwater. The sorption of iodine is affected by the iodine species in the source water. Iodine loading on resins using source water ranged from 1.47 to 1.70 µg/g with the corresponding Kd values from 189.9 to 227.0 mL/g. The sorption values when the iodine is converted to iodide ranged from 2.75 to 5.90 µg/g with the corresponding Kd values from 536.3 to 2979.6 mL/g. It is recommended that methods to convert iodine to iodide be investigated in fiscal year (FY) 2015. The chemicals used to convert iodine to iodate adversely affected the sorption of iodine onto the carbon materials. Using as-received source water, loading and Kd values ranged from 1.47 to 1.70 µg/g and 189.8 to 226.3 mL/g respectively. After treatment, loading and Kd values could not be calculated because there was little change between the initial and final iodine concentration. It is recommended the cause of the decrease in iodine sorption be investigated in FY15. In direct support of CH2M HILL Plateau Remediation Company, Pacific Northwest National Laboratory has evaluated samples from within the 200W pump and treat bioreactors. As part of this analysis, pictures taken within the bioreactor reveal a precipitate that, based on physical properties and known aqueous chemistry, is hypothesized to be iron pyrite or chalcopyrite, which could affect iodine adsorption. It is recommended these materials be tested at different solution-to-solid ratios in FY15 to determine their effect on iodine

  17. Potential heat exchange fluids for use in sulfuric acid vaporizers

    NASA Technical Reports Server (NTRS)

    Lawson, D. D.; Petersen, G. R.

    1981-01-01

    A series of liquids have been screened as candidate heat exchange fluids for service in thermochemical cycles that involve the vaporization of sulfuric acid. The required chemical and physical criteria of the liquids is described with the results of some preliminary high temperature test data presented.

  18. Heat-Exchange Fluids for Sulfuric Acid Vaporizers

    NASA Technical Reports Server (NTRS)

    Lawson, D. D.; Petersen, G. R.

    1982-01-01

    Some fluorine-substituted organic materials meet criteria for heat-exchange fluids in contact with sulfuric acid. Most promising of these are perfluoropropylene oxide polymers with degree of polymerization (DP) between 10 and 50. It is desirable to have DP in high range because vapor pressure of material decreases as DP increases, and high-DP liquids have lower loss due to vaporization.

  19. Separation of certain carboxylic acids utilizing cation exchange membranes

    DOEpatents

    Chum, Helena L.; Sopher, David W.

    1984-01-01

    A method of substantially separating monofunctional lower carboxylic acids from a liquid mixture containing the acids wherein the pH of the mixture is adjusted to a value in the range of from about 1 to about 5 to form protonated acids. The mixture is heated to an elevated temperature not greater than about 100.degree. C. and brought in contact with one side of a perfluorinated cation exchange membrane having sulfonate or carboxylate groups or mixtures thereof with the mixture containing the protonated acids. A pressure gradient can be established across the membrane with the mixture being under higher pressure, so that protonated monofunctional lower carboxylic acids pass through the membrane at a substantially faster rate than the remainder of the mixture thereby substantially separating the acids from the mixture.

  20. Separation of certain carboxylic acids utilizing cation exchange membranes

    DOEpatents

    Chum, H.L.; Sopher, D.W.

    1983-05-09

    A method of substantially separating monofunctional lower carboxylic acids from a liquid mixture containing the acids wherein the pH of the mixture is adjusted to a value in the range of from about 1 to about 5 to form protonated acids. The mixture is heated to an elevated temperature not greater than about 100/sup 0/C and brought in contact with one side of a perfluorinated cation exchange membrane having sulfonate or carboxylate groups or mixtures thereof with the mixture containing the protonated acids. A pressure gradient can be established across the membrane with the mixture being under higher pressure, so that protonated monofunctional lower carboxylic acids pass through the membrane at a substantially faster rate than the remainder of the mixture thereby substantially separating the acids from the mixture.

  1. Separation of nucleic acids by high-performance ion-exchange chromatography.

    PubMed

    Yamazaki, K; Tomizawa, H; Miyanaga, A; Ishikawa, O; Nakatani, S; Moriyama, H

    1995-01-01

    Separation of various nucleic acids was evaluated by high-performance ion-exchange chromatography on non-porous resin, TSKgel DNA-NPR. A 1 kb ladder DNA was studied as a model DNA on operational variables like flow rate, gradient time, temperature, sample load, etc.. As results, various DNA fragments were well separated within 15 min by 20 min linear gradient at a flow rate between 0.5 and 0.75 ml/min at room temperature while the resolutin was dependent on molecular weight of the sample. The relationship between sample load and its peak area was examined on polymerase chain reaction (PCR) product. The product was found to be quantitatively recovered even with nanogram loads. The detection limit was 3.8 ng at signal to noise level (S/N) of 3. This non-porous ion-exchanger also showed high resolution on separation of ther nucleic acids like transfer RNA, oligonucleotides (single-stranded) DNA. PMID:8841596

  2. Swelling behavior of ion exchange resins incorporated in tri-calcium silicate cement matrix: II. Mechanical analysis

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    This paper presents the second part of a study aiming at modelling the mechanical behavior of composites made up of ion exchange resins (IER) solidified in a tri-calcium silicate cement paste (C3S). Such composites may be subjected to internal pressures due to ion exchange processes between ionic species which are in IER and interstitial solution of the cement paste. The reactive transport model developed in the companion paper is coupled in this study to a multi-scale approach describing the mechanical behavior of the material. It is based on an analogy with thermomechanics for taking in account the IER internal pressures, and on Eshelby-based homogenization techniques to estimate both mechanical and coupling parameters. A laboratory test has been set up to measure the macroscopic strain caused by the swelling phenomenon. The model has been finally implemented in a finite elements software. The simulation of the laboratory tests has been performed and the results have been analyzed and compared to experimental data.

  3. The influence of EI-21 redox ion-exchange resins on the secondary-coolant circuit water chemistry of vehicular nuclear power installations

    NASA Astrophysics Data System (ADS)

    Moskvin, L. N.; Rakov, V. T.

    2015-06-01

    The results obtained from testing the secondary-coolant circuit water chemistry of full-scale land-based prototype bench models of vehicular nuclear power installations equipped with water-cooled water-moderated and liquid-metal reactor plants are presented. The influence of copper-containing redox ionexchange resins intended for chemically deoxygenating steam condensate on the working fluid circulation loop's water chemistry is determined. The influence of redox ion-exchange resins on the water chemistry is evaluated by generalizing an array of data obtained in the course of extended monitoring using the methods relating to physicochemical analysis of the quality of condensate-feedwater path media and the methods relating to metallographic analysis of the state of a faulty steam generator's tube system surfaces. The deoxygenating effectiveness of the normal state turbine condensate vacuum deaeration system is experimentally determined. The refusal from applying redox ion-exchange resins in the condensate polishing ion-exchange filters is formulated based on the obtained data on the adverse effect of copper-containing redox ionexchange resins on the condensate-feedwater path water chemistry and based on the data testifying a sufficient effect from using the normal state turbine condensate vacuum deaeration system. Data on long-term operation of the prototype bench model of a vehicular nuclear power installation without subjecting the turbine condensate to chemical deoxygenation are presented.

  4. Ion-exchange resin for removing hexavalent chromium from ground water at treatment facility C: Data on removal capacity, regeneration efficiency, and operation

    SciTech Connect

    Bahowick, S.; Dobie, D.; Kumamoto, G.

    1996-12-31

    Lawrence Livermore National Laboratory (LLNL) is operated for the Department of Energy by the University of California. In July 1987, LLNL was placed on the National Priorities List based on the presence of volatile organic compounds (VOCs) in ground water. The July 1992 Record of Decision stipulates air stripping for treatment of VOCs and ion-exchange to treat chromium in the ground water for Treatment Facility C (TFC). TFC, which was activated in October 1993, was designed to treat influent ground water at 60 gpm with concentrations of hexavalent chromium averaging 30 ppb. The ion exchange system removes the hexavalent chromium to below its limit of detection (2 ppb). The resin used is a strongly basic Type I quaternary ammonium anion exchange resin with a styrene-divinylbenzene copolymer gel matrix. The total hexavalent chromium removed from the ground water as of October 8, 1995 was 660 grams. An initial operating capacity was achieved of 6.4 grams CrO{sub 4}{sup 2{minus}} removal per ft{sup 3} of resin, but this was observed to vary over the next two years. Variation was observed in the rate of breakthrough. The regeneration process was optimized to minimize waste produced and maximize regeneration of the resin. Elevated levels of chloride, sulfate, nitrate, potassium 40 and uranium have been observed in the regeneration waste. Because of the potassium and uranium content, the regenerated waste had to be disposed of as mixed waste.

  5. 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.

  6. Comparison of ion-exchange resin counterions in the nutrient measurement of calcareous soils: Implications for correlative studies of plant-soil relationships

    USGS Publications Warehouse

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

    2003-01-01

    For more than 40 years, ion-exchange resins have been used to characterize nutrient bioavailability in terrestrial and aquatic ecosystems. To date, however, no standardized methodology has been developed, particularly with respect to the counterions that initially occupy resin exchange sites. To determine whether different resin counterions yield different measures of soil nutrients and rank soils differently with respect to their measured nutrient bioavailability, we compared nutrient measurements by three common counterion combinations (HCl, HOH, and NaHCO3). Five sandy calcareous soils were chosen to represent a range of soil characteristics at Canyonlands National Park, Utah, and resin capsules charged with the different counterions equilibrated in saturated pastes of these soils for one week. Data were converted to proportions of total ions of corresponding charge for ANOVA. Results from the different methods were not comparable with respect to any nutrient. Of eleven nutrients measured, all but iron (Fe2+), manganese (Mn2+), and zinc (Zn2+) differed significantly (p ??? 0.05) as a function of soil x counterion interactions; Fe2+ and Zn2+ varied as functions of counterion alone. Of the counterion combinations, HCl-resins yielded the most net ion exchange with all measured nutrients except Na+, NH4+, and HPO42-, the three of which desorbed in the greatest quantities from HOH-resins. Conventional chemical extractions using ammonium acetate generally yielded high proportional values of Ca2+, K+, and Na+. Further, among-soil rankings of nutrient bioavailability varied widely among methods. This study highlights the fact that various ion-exchange resin techniques for measuring soil nutrients may have differential effects on the soil-resin environment and yield data that should not be compared nor considered interchangeable. The most appropriate methods for characterizing soil-nutrient bioavailability depends on soil characteristics and likely on the physiological

  7. Comparison of ion-exchange resin counterions in the nutrient measurement of calcareous soils: implications for correlative studies of plant-soil relationships

    USGS Publications Warehouse

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

    2003-01-01

    For more than 40 years, ion-exchange resins have been used to characterize nutrient bioavailability in terrestrial and aquatic ecosystems. To date, however, no standardized methodology has been developed, particularly with respect to the counterions that initially occupy resin exchange sites. To determine whether different resin counterions yield different measures of soil nutrients and rank soils differently with respect to their measured nutrient bioavailability, we compared nutrient measurements by three common counterion combinations (HCl, HOH, and NaHCO3). Five sandy calcareous soils were chosen to represent a range of soil characteristics at Canyonlands National Park, Utah, and resin capsules charged with the different counterions equilibrated in saturated pastes of these soils for one week. Data were converted to proportions of total ions of corresponding charge for ANOVA. Results from the different methods were not comparable with respect to any nutrient. Of eleven nutrients measured, all but iron (Fe2+), manganese (Mn2+), and zinc (Zn2+) differed significantly (pa??0.05) as a function of soilcounterion interactions; Fe2+ and Zn2+ varied as functions of counterion alone. Of the counterion combinations, HCl-resins yielded the most net ion exchange with all measured nutrients except Na+, and the three of which desorbed in the greatest quantities from HOH-resins. Conventional chemical extractions using ammonium acetate generally yielded high proportional values of Ca2+, K+, and Na+. Further, among-soil rankings of nutrient bioavailability varied widely among methods. This study highlights the fact that various ion-exchange resin techniques for measuring soil nutrients may have differential effects on the soil-resin environment and yield data that should not be compared nor considered interchangeable. The most appropriate methods for characterizing soil-nutrient bioavailability depends on soil characteristics and likely on the physiological uptake mechanisms of

  8. 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.

  9. Effect of long-term organic removal on ion exchange properties and performance during sewage tertiary treatment by conventional anion exchange resins.

    PubMed

    Sun, Jian; Li, Xiaofeng; Quan, Ying; Yin, Yunjun; Zheng, Shaokui

    2015-10-01

    This study evaluated the long-term dissolved organic matter (DOM), phosphorus and nitrogen removal performance of a commercially available conventional anion exchange resin (AER) from actual secondary effluent (SE) in a sewage treatment plant based on a pilot-scale operation (2.2 m(3) d(-1), 185 cycles, 37,000 bed volume, 1.5 years). Particular emphasis was given to the potential effect of DOM fouling on the ion exchange properties and performance during the long-term operation. Despite the large range of COD (15.6-33.5 mg L(-1)), BOD5 (3.0-5.6 mg L(-1)), DOC (6.5-24.2 mg L(-1)), and UV254 (UV absorption at 254 nm) (0.108-0.229 cm(-1)) levels in the SE, the removal efficiencies of the AER for the aforementioned parameters were 43±12%, 46±15%, 45±9%, and 72±4%, respectively. Based on three-dimensional fluorescence excitation-emission matrix data, i.e., the fluorescence intensities of four regions (peaks A-D), all organic components of the SE were effectively removed (peak A 74%, peak B 48%, peak C 55%, and peak D 45%) following the adsorption. The AER effluent still has considerable polycyclic aromatic hydrocarbons' ecological hazard on freshwater fishes when they were significantly removed from SE. The obvious DOM fouling on the AER, identified by color change, had no significant influence on the long-term removal of the representative inorganic anions (averaging 95±4% phosphate, 100±0% SO4(2-), and 62±17% NO3(-)) and AER properties (including total exchange capacity, moisture content, and true density). The conventional AER can produce high quality reclaimed water from SE at a low operational cost. PMID:25996990

  10. FINAL REPORT. NEW ANION-EXCHANGE RESINS FOR IMPROVED SEPARATIONS OF NUCLEAR MATERIALS

    EPA Science Inventory

    The overall objective of this project was to develop a predictive capability that would enable us to design and implement new anion-exchange materials that selectively sorb metal complexes. Our approach was to extend the principles applied to optimization of chelating ligands (i....

  11. Fixed bed adsorption of 2-naphthalenesulfonic acid from aqueous solution by composite resin.

    PubMed

    Jia, Dong M; Li, Ya P; Li, Yue J; Li, Yong G; Li, Chang H

    2014-02-01

    Adsorption behavior of the iron impregnated, weakly basic resin D301 (Fe-D301) for removal of 2-naphthalenesulfonic acid (2-NSA) from aqueous solution was studied by using a fixed-bed column. The effects of process variables such as bed height, flow rate, and coexisting ions were investigated. The results indicated that the breakpoint and exhaustion point increased with increasing bed height and decreased with increasing 2-NSA flowrate. Experimental data showed a strong fit to the Bed Depth Service Time model. The coexisting ions in the 2-NSA solution had a clear effect on the breakthrough volume. The high extent of recovery of 2-NSA with good reproducibility provided an effective method for the separation of 2-NSA by the adsorbent Fe-D301. PMID:24645539

  12. Low pressure process for continuous fiber reinforced polyamic acid resin matrix composite laminates

    NASA Technical Reports Server (NTRS)

    Druyun, Darleen A. (Inventor); Hou, Tan-Hung (Inventor); Kidder, Paul W. (Inventor); Reddy, Rakasi M. (Inventor); Baucom, Robert M. (Inventor)

    1994-01-01

    A low pressure processor was developed for preparing a well-consolidated polyimide composite laminate. Prepreg plies were formed from unidirectional fibers and a polyamic acid resin solution. Molding stops were placed at the sides of a matched metal die mold. The prepreg plies were cut shorter than the length of the mold in the in-plane lateral direction and were stacked between the molding stops to a height which was higher than the molding stops. The plies were then compressed to the height of the stops and heated to allow the volatiles to escape and to start the imidization reaction. After removing the stops from the mold, the heat was increased and 0 - 500 psi was applied to complete the imidization reaction. The heat and pressure were further increased to form a consolidated polyimide composite laminate.

  13. Recovery of nickel and cobalt from organic acid complexes: adsorption mechanisms of metal-organic complexes onto aminophosphonate chelating resin.

    PubMed

    Deepatana, A; Valix, M

    2006-09-21

    This study examined the recovery of nickel and cobalt from organic acid complexes using a chelating aminophosphonate Purolite S950 resin. These metal complexes are generated by bioleaching nickel laterite ores, a commercial nickel and cobalt mineral oxide, with heterotrophic organism and their metabolites or organic acid products. Equilibrium adsorption tests were conducted as a function of Ni and Co concentrations (15-2000 mg/L), solution pH (0.01 and 0.1 M acids) and three metabolic complexing agents (citrate, malate and lactate). It was shown that the adsorption of the various Ni- and Co-complexes on Purolite were quite low, 16-18 and 5.4-9 mg/g of resin, respectively, in comparison to the smaller nickel ions and nickel sulfate. This was attributed to the bulky organic ligands which promoted crowding effect or steric hindrance. The adsorption of these complexes was further hampered by the strong affinity of the resin to H+ ions under acidic conditions. Mechanisms of adsorption, as inferred from the fitted empirical Langmuir and Freundlich models, were correlated to the proposed steric hindrance and competitive adsorption effects. Nickel and cobalt elution from the resin were found be effective and were independent of the type of metal complexes and metal concentrations. This study demonstrated the relative challenges involved in recovering nickel and cobalt from bioleaching solutions. PMID:16698178

  14. [Determination of trace nickel in bi-based superconductor powder by inductively coupled plasma atomic emission spectroscopy after separation with anion exchange resin and extraction with methylbenzene].

    PubMed

    Fan, Li-xin; Li, Jian-qiang; Fan, Hui-li; Sun, Jian-ling; Zhang, Xia; Bao, Rui; Lu, Qing; Wang, Jie

    2011-12-01

    A new method for the determination of trace nickel in superconductor powder by ICP-AES was proposed. The instrument parameters were optimized, and the matrix effects as well as the method of eliminating interferences were also studied systemically. The results showed that matrix interference in the superconductor powder was serious when the amount of matrix increased, and the repeatability as well as the accuracy was poor, so it was necessary to used separation and preconcentration to improve the accuracy and precision. In this experiment, Ni-diacetyl dioxime complexes were enriched by toluene extraction in alkaline condition after eliminating the interference of major element Bi and partial Pb, Sr, Ca and Cu by eluting with anion exchange resin, then the Ni-complexes were back extracted by diluted hydrochloric acid. The enrichment conditions were investigated in detail and the recovery rate of Ni was higher than 95%. Under the optimal condition, an artificial sample was analysed, the result showed that the found values were identical with reference values, and the RSD and detection limit were 1.9% and 0.19 microg x g(-1), respectively. The method has been applied to the determination of trace nickel in Bi-based superconductor powder samples with satisfactory results. PMID:22295798

  15. Comparative assessment of the methods for exchangeable acidity measuring

    NASA Astrophysics Data System (ADS)

    Vanchikova, E. V.; Shamrikova, E. V.; Bespyatykh, N. V.; Zaboeva, G. A.; Bobrova, Yu. I.; Kyz"yurova, E. V.; Grishchenko, N. V.

    2016-05-01

    A comparative assessment of the results of measuring the exchangeable acidity and its components by different methods was performed for the main mineral genetic horizons of texturally-differentiated gleyed and nongleyed soddy-podzolic and gley-podzolic soils of the Komi Republic. It was shown that the contents of all the components of exchangeable soil acidity determined by the Russian method (with potassium chloride solution as extractant, c(KCl) = 1 mol/dm3) were significantly higher than those obtained by the international method (with barium chloride solution as extractant, c(BaCl2) = 0.1 mol/dm3). The error of the estimate of the concentration of H+ ions extracted with barium chloride solution equaled 100%, and this allowed only qualitative description of this component of the soil acidity. In the case of the extraction with potassium chloride, the error of measurements was 50%. It was also shown that the use of potentiometric titration suggested by the Russian method overestimates the results of soil acidity measurement caused by the exchangeable metal ions (Al(III), Fe(III), and Mn(II)) in comparison with the atomic emission method.

  16. Sorption of beryllium from sulfate solutions by amino-carboxylic amphoteric ion-exchange resins (polyampholytes)

    SciTech Connect

    Pakholkov, V.S.; Tsevin, A.P.; Rychkov, V.N.

    1986-05-10

    In studies of sorption of beryllium ions from BeSO4 solutions by a series of aminocarboxylic polyampholytes the influence of pH and of the H2SO4, (NH4)2SO4, and BeSO4 concentrations was demonstrated. The mechanism of the process is postulated on the basis of sorption data and the results of IR-spectroscopic studies. It is concluded that carboxyl groups of polyampholytes take part in ion exchange.

  17. BARIUM AND RADIUM REMOVAL FROM GROUNDWATER BY ION EXCHANGE

    EPA Science Inventory

    The primary objective of this study was to determine the applicability of weak acid exchange resin in the hydrogen form for removal of hardness, barium and radium from groundwater. Weak acid resin in the hydrogen form eliminates the addition of sodium to drinking water. The capac...

  18. Synthesis and Characterization of Templated Ion Exchange Resins for the Selective Complexation of Actinide Ions

    SciTech Connect

    Uy, O. Manual

    2001-03-01

    The purpose of this research is to develop a polymeric extractant for the selective complexation of uranyl ions (and subsequently other actinyl and actinide ions) from aqueous solutions (lakes, streams, waste tanks and even body fluids). Chemical insights into what makes a good complexation site will be used to synthesize reagents tailor-made for the complexation of uranyl and other actinide ions. These insights, derived from studies of molecular recognition include ion coordination number and geometry, ionic size and ionic shape, as well as ion to ligand thermodynamic affinity. Selectivity for a specific actinide ion will be obtained by providing the polymers with cavities lined with complexing ligands so arranged as to match the charge, coordination number, coordination geometry, and size of the actinide metal ion. These cavity-containing polymers will be produced by using a specific ion (or surrogate) as a template around which monomeric complexing ligands will be polymerized. The complexing ligands will be ones containing functional groups known to form stable complexes with a specific ion and less stable complexes with other cations. Prior investigator's approaches for making templated resins for metal ions have had marginal success. We have extended and amended these methodologies in our work with Pb(II) and uranyl ion, by changing the order of the steps, by the inclusion of sonication, by using higher complex loading, and the selection of functional groups with better complexation constants. This has resulted in significant improvements to selectivity. The unusual shape of the uranyl ion suggests that this approach will result in even greater selectivities than already observed for Pb(II). Preliminary data obtained for uranyl templated polymers shows unprecedented selectivity and has resulted in the first ion selective electrode for uranyl ion.

  19. Efficiency of pretreatment of aqueous samples using a macroporous strong anion-exchange resin on the determination of nerve gas hydrolysis products by gas chromatography-mass spectrometry after tert.-butyldimethylsilylation.

    PubMed

    Kataoka, M; Tsuge, K; Seto, Y

    2000-09-01

    A pretreatment procedure, using a macroporous strong anion-exchange resin (MSA) has been established for the determination of nerve gas hydrolysis products by gas chromatography-mass spectrometry (GC-MS) after tert.-butyldimethylsilyl (TBDMS) derivatization. Aqueous solutions of methylphosphonic acid (MPA) and three alkyl methylphosphonic acids (AMPAs) (ethyl, isopropyl and pinacolyl methylphosphonic acid), were retained on the MSA column, and then quantitatively eluted with 0.1 M hydrochloric acid. The neutralized column eluate was dried, and MPA and AMPAs were derivatized with N-methyl-N-(tert.-butyldimethylsilyl)-trifluoroacetamide and analyzed by GC-MS. The column eluate was also analyzed in order to determine the exact hydrolysis product levels by capillary electrophoresis using borate and benzoate buffer (pH 6). The MSA pretreatment was examined for the clean-up of aqueous extracts of three types of soils and an aqueous solution containing 10% sucrose, which is regarded as model for a typical soft drink, after spiking with MPA and AMPAs. MPA and AMPAs were quantitatively recovered in the MSA eluate fraction from those samples, except for MPA from volcanic acid and alluvial soils. The yields of TBDMS derivatives were remarkably improved, compared with for which no pretreatment was used and also for those in which a strong cation-exchange resin was used. The achieved detection limits of MPA and AMPAs ranged from 0.12 to 0.18 microg/g of soil (S/N=3). The established MSA method was applied to the pretreatment of spiked sea water, two types of beverages, Pepsi Cola and canned coffee. Although the yields of TBDMS derivatives of MPA and AMPAs in sea water (in a range between 44 and 96%) and AMPAs in Pepsi Cola (in a range between 58 and 92%) were rather high, those for MPA in the Pepsi Cola (27%) and those for MPA and AMPAs in the canned coffee (in a range between 5 and 17%) were low. PMID:11043790

  20. Isotopic exchange of hydrogen in aromatic amino acids

    SciTech Connect

    Pshenichnikova, A.B.; Karnaukhova, E.N.; Mitsner, B.I.

    1993-10-20

    The kinetics of the isotopic replacement of hydrogen in the aromatic amino acids L-tryptophan, L-tyrosine, and L-phenylalanine in solutions of deuterochloric and deuterosulfuric acids in deuterium oxide were investigated by PMR spectroscopy. The reactions were shown to be of first orders with respect both to the concentration of the substrate and to the activity of the deuterium ion. The isotopic effects of hydrogen and the values of the activation energy of H-D exchange in different positions of the aromatic ring in tryptophan and tyrosine were determined. The effect of properties of the medium on the rate of the isotopic exchange of hydrogen is discussed. 17 refs., 2 figs., 2 tabs.

  1. Use of strong anion exchange resins for the removal of perfluoroalkylated substances from contaminated drinking water in batch and continuous pilot plants.

    PubMed

    Zaggia, Alessandro; Conte, Lino; Falletti, Luigi; Fant, Massimo; Chiorboli, Andrea

    2016-03-15

    In recent years abnormally high levels of perfluoroalkylated substances (PFAS) have been detected both in surface and underground water sampled in an area covering approximately 150 square kilometers in the Veneto region (Italy) indicating the presence of a pollution point source (fluorochemicals production plant). Adsorption on granular activated carbon is an emergency measure which is poorly effective requiring frequent replacement. This work focuses on the application of three strong anion exchange resins (Purolite® A520E, A600E and A532E) for the removal of traces of PFOA, PFOS, PFBA and PFBS (concentration of hundreds of ng L(-1)) from drinking water. This technology is attractive for the possibility of reusing resins after an in-situ regeneration step. A strong relationship between the hydrophobicity of the exchange functional group of the resin and its capacity in removing PFAS exists. A600E (non hydrophobic) and A520E (fairly hydrophobic) show a reduced sorption capacity compared to A532E (highly hydrophobic). While A600E and A520E can be regenerated with solvent-less dilute solutions of non-toxic NH4Cl and NH4OH, A532E requires concentrated solutions of methanol or ethanol and 1% NH4Cl and for the sake of this work it was regarded as non-regenerable. The volume of regeneration effluents requiring incineration can be efficiently reduced by more than 96.5% by using reverse osmosis coupled with under-vacuum evaporation. Transmission electron analysis on saturated resins showed that large molecular macro-aggregates of PFAS can form in the intraparticle pores of resin indicating that ion exchange is not the only mechanism involved in PFAS removal. PMID:26774262

  2. Structure/function studies of resorcinol-formaldehyde (R-F) and phenol-formaldehyde (P-F) copolymer ion-exchange resins

    SciTech Connect

    Hubler, T.L.; Franz, J.A.; Shaw, W.J.; Hogan, M.O.; Hallen, R.T.; Brown, G.N.; Linehan, J.C.

    1996-09-01

    he U.S. Department of Energy`s (DOE) Hanford Site was established to produce plutonium for the U.S. defense mission. Over the course of decades, hazardous, toxic, and radioactive chemical wastes were generated and disposed of in a variety of ways including storage in underground tanks. An estimated 180 million tons of high-level radioactive wastes are stored in 177 underground storage tanks. During production of fissile plutonium, large quantities of 90Sr and 137CS were produced. The high abundance and intermediate length half- lives of these fission products are the reason that effort is directed toward selective removal of these radionuclides from the bulk waste stream before final tank waste disposal is effected. Economically, it is desirable to remove the highly radioactive fraction of the tank waste for vitrification. Ion-exchange technology is being evaluated for removing cesium from Hanford Site waste tanks. This report summarizes data and analysis performed by Pacific Northwest National Laboratory (PNNL)for both resorcinol-formaldehyde (R-F) and phenol-formaldehyde (P-F) resins and relates their observed differences in performance and chemical stability to their structure. The experimental approach used to characterize the resins was conducted using primarily two types of data: batch distribution coefficients (Kds) and solid-state 13C NMR. Comparison of these data for a particular resin allowed correlation of resin performance to resin structure. Additional characterization techniques included solid-state 19F NMR, and elemental analyses.

  3. Radiological implications of readings with a NaI(Tl) monitor set on an ion exchange resin column for purifying primary coolant water.

    PubMed

    Fukui, M

    1994-12-01

    Changes in readings of a NaI(Tl) monitor set on the surface of an ion exchange resin column used to purify primary coolant water at the Kyoto University Research Reactor were examined with mathematical models to clarify the radiological meanings. The concentration distributions of the nuclides in the interstitial water of the resin bed and those adsorbed on the resins were determined by use of the dispersion-convection theory coupled with the linear isotherm adsorption relation. The adsorbed amount that was assessed by this model was theoretically related to that made by a compartmental model. The buildup concentrations of nuclides in the core water and the decreased accompanying power operation and shut-down were modeled using the value representing the cleanup rate by the purification circuit. The values of this parameter were determined by the least squares method for observed concentrations of 24Na, a major radionuclide in the core water. Recognizing that the adsorption band had remained within the top 10 cm during the circulation of water through the column, the change in the amount of radionuclide adsorbed on the resin was calculated using a compartmental model. The amount of radionuclide adsorbed on the resin predicted by the model agreed well with the readings of the NaI(TI) monitor. Factors that affect the reading are discussed in relation to early detection of fuel defects. PMID:7960785

  4. Conductivity measures coupled with treatment with ion-exchange resin for the assessment of sodium concentration in physiological fluids: analyses on artificial solutions

    NASA Astrophysics Data System (ADS)

    Tura, A.; Sbrignadello, S.; Mambelli, E.; Ravazzani, P.; Santoro, A.; Pacini, G.

    2013-09-01

    In humans, sodium is essential for the regulation of blood volume and pressure. During hemodialysis, sodium measurement is important to preserve the patient from hypo- or hyper-natremia Usually, sodium measurement is performed through laboratory equipment which is typically expensive, and requires manual intervention. We propose a new method, based on conductivity measurement after treatment of dialysate solution through ion-exchange resin. To test this method, we performed in vitro experiments. We prepared 40 ml sodium chloride (NaCl) samples at 280, 140, 70, 35, 17.5, 8.75, 4.375 mEq/l, and some "mixed samples", i.e., with added potassium chloride (KCl) at different concentrations (4.375-17.5 mEq/l), to simulate the confounding factors in a conductivity-based sodium measurement. We measured the conductivity of all samples. Afterwards, each sample was treated for 1 min with 1 g of Dowex G-26 resin, and conductivity measured again. On average, the difference ɛ in the conductivity between mixed samples and corresponding pure NaCl samples (at the same NaCl concentration) was 20.9%. With treatment with the resin, it was 9.9%, only. We conclude that ion-exchange resin treatment coupled with conductivity measures may be a possible simple approach for continuous and automatic sodium measurement during hemodialysis.

  5. The Isomerization of (-)-Menthone to (+)-Isomenthone Catalyzed by an Ion-Exchange Resin

    ERIC Educational Resources Information Center

    Ginzburg, Aurora L.; Baca, Nicholas A.; Hampton, Philip D.

    2014-01-01

    A traditional organic chemistry laboratory experiment involves the acid-catalyzed isomerization of (-)-menthone to (+)-isomenthone. This experiment generates large quantities of organic and aqueous waste, and only allows the final ratio of isomers to be determined. A "green" modification has been developed that replaces the mineral acid…

  6. Evaluation of SuperLig 639 Ion Exchange Resin for the Removal of Rhenium from Hanford Envelope A Simulant

    SciTech Connect

    King, W.D.

    2000-07-27

    Hanford Radioactive Waste materials have been categorized into four envelopes labeled A through D as specified in the Tank Waste Remediation Contract between BNFL and DOE. 1 Envelopes A, B and C contain only solubilized species and are specified as Low-Activity Waste (LAW). Each envelope is defined based on compositional maximums of chemical and radioactive constituents. Envelopes A and B contain low concentrations of organic species and the primary form of technetium is pertechnetate (TcO4-). Envelope C contains higher levels of organic species and technetium which is primarily in the nonpertechnetate form (presumably complexed TcO2). Envelope D is sludge which has been separated from the supernate and is referred to as High Activity Waste. The current plant design utilizes SuperLig ion exchange resins to remove cesium and technetium (the primary radioactive constituents) from the Hanford LAW. The process is designed to produce a decontaminated waste stream and a concentrated eluate waste stream for vitrification into low and high activity glasses, respectively.

  7. Optimization of Cesium Removal from Hanford Envelope A Simulant with SuperLig 639 Ion Exchange Resin

    SciTech Connect

    King, W.D.

    2000-07-27

    Hanford RadioactiveWaste materials have been categorized into four envelopes labeled A through D as specified in the Tank Waste Remediation Contract between BNFL and DOE. 1 Envelopes A, B and C contain only solubilized species and are specified as Low-Activity Waste (LAW). Each envelope is defined based on compositional maximums of chemical and radioactive constituents. Envelopes A and B contain low concentrations of organic species and the primary form of technetium is pertechnetate (TcO4-). Envelope C contains higher levels of organic species and technetium which is primarily in the nonpertechnetate form (presumably complexed TcO2). Envelope D is sludge which has been separated from the supernate and is referred to as High Activity Waste. The current plant design utilizes SuperLig ion exchange resins to remove cesium and technetium (the primary radioactive constituents) from the Hanford LAW. The process is designed to produce a decontaminated waste stream and a concentrated eluate waste stream for vitrification into low and high activity glasses, respectively.

  8. Production of citric acid using its extraction wastewater treated by anaerobic digestion and ion exchange in an integrated citric acid-methane fermentation process.

    PubMed

    Xu, Jian; Chen, Yang-Qiu; Zhang, Hong-Jian; Tang, Lei; Wang, Ke; Zhang, Jian-Hua; Chen, Xu-Sheng; Mao, Zhong-Gui

    2014-08-01

    In order to solve the problem of extraction wastewater pollution in citric acid industry, an integrated citric acid-methane fermentation process is proposed in this study. Extraction wastewater was treated by mesophilic anaerobic digestion and then used to make mash for the next batch of citric acid fermentation. The recycling process was done for seven batches. Citric acid production (82.4 g/L on average) decreased by 34.1 % in the recycling batches (2nd-7th) compared with the first batch. And the residual reducing sugar exceeded 40 g/L on average in the recycling batches. Pigment substances, acetic acid, ammonium, and metal ions in anaerobic digestion effluent (ADE) were considered to be the inhibitors, and their effects on the fermentation were studied. Results indicated that ammonium, Na(+) and K(+) in the ADE significantly inhibited citric acid fermentation. Therefore, the ADE was treated by acidic cation exchange resin prior to reuse to make mash for citric acid fermentation. The recycling process was performed for ten batches, and citric acid productions in the recycling batches were 126.6 g/L on average, increasing by 1.7 % compared with the first batch. This process could eliminate extraction wastewater discharge and reduce water resource consumption. PMID:24522611

  9. Comparative investigations of anion-exchange resins of the AM-3 and amberlite IRA-93 type in relati ion to water Treatment

    SciTech Connect

    Davydova, G.N.; Kulyako, N.I.; Znauenskii, Y.P.; Zorina, A.I.

    1985-10-01

    The typical kinetic curves for sorption of HC1 by the anion-exchangers IRA-93 and AM-3-10 are shown. The principal experimental data on all the samples studied are presented and it follows that all the AM-3 samples are somewhat inferior to the kinetic properties of Amberlite IRA-93. It is suggested that for improvement of the kinetic properties of AM-3 resins it is necessary to alter the structure of the micrograins, increasing their permeability.

  10. Process for the preparation of lactic acid and glyceric acid

    DOEpatents

    Jackson, James E [Haslett, MI; Miller, Dennis J [Okemos, MI; Marincean, Simona [Dewitt, MI

    2008-12-02

    Hexose and pentose monosaccharides are degraded to lactic acid and glyceric acid in an aqueous solution in the presence of an excess of a strongly anionic exchange resin, such as AMBERLITE IRN78 and AMBERLITE IRA400. The glyceric acid and lactic acid can be separated from the aqueous solution. Lactic acid and glyceric acid are staple articles of commerce.

  11. Separation of Technetium in Nitric Acid Solution With an Extractant Impregnated Resin

    SciTech Connect

    Jei Kwon Moon; Eil Hee Lee; Chong-Hun Jung; Byung Chul Lee

    2006-07-01

    An extractant impregnated resin (EIR) was prepared by impregnation of Aliquat 336 into Amberlite XAD-4 for separation of technetium from rhodium in nitric acid solution. The prepared EIR showed high preference for rhenium (chemical analogue of technetium) over rhodium. The adsorption isotherms for rhenium were described well by Langmuir equation in both the single and multi-component systems. Maximum adsorption capacities obtained by modelling the isotherms of rhenium were 2.01 meq g{sup -1} and 1.97 meq g{sup -1} for the single and the multi-component systems, respectively. Column tests were also performed to confirm the separation efficiency of rhenium using a jacketed glass column (diam. 11 x L 150). The EIR column showed successful separation of rhenium with the breakthrough volume of about 122 BV for the breakthrough concentration of 0.08. Also the breakthrough data were modelled successfully by assuming a homogeneous diffusion model in the particle phase. The diffusivities obtained from the modelling were in the order of 10{sup -7} cm{sup 2} min{sup -1} for a rhenium. The rhenium adsorbed on the bed could be eluted with a high purity by using a nitric acid solution. (authors)

  12. Novel bioactive polyester scaffolds prepared from unsaturated resins based on isosorbide and succinic acid.

    PubMed

    Smiga-Matuszowicz, Monika; Janicki, Bartosz; Jaszcz, Katarzyna; Łukaszczyk, Jan; Kaczmarek, Marcin; Lesiak, Marta; Sieroń, Aleksander L; Simka, Wojciech; Mierzwiński, Maciej; Kusz, Damian

    2014-12-01

    In this study new biodegradable materials obtained by crosslinking poly(3-allyloxy-1,2-propylene succinate) (PSAGE) with oligo(isosorbide maleate) (OMIS) and small amount of methyl methacrylate were investigated. The porous scaffolds were obtained in the presence of a foaming system consisted of calcium carbonate/carboxylic acid mixture, creating in situ porous structure during crosslinking of liquid formulations. The maximum crosslinking temperature and setting time, the cured porous materials morphology as well as the effect of their porosity on mechanical properties and hydrolytic degradation process were evaluated. It was found that the kind of carboxylic acid used in the foaming system influenced compressive strength and compressive modulus of porous scaffolds. The MTS cytotoxicity assay was carried out for OMIS using hFOB1.19 cell line. OMIS resin was found to be non-toxic in wide range of concentrations. On the ground of scanning electron microscopy (SEM) observations and energy X-ray dispersive analysis (EDX) it was found that hydroxyapatite (HA) formation at the scaffolds surfaces within short period of soaking in phosphate buffer solution occurs. After 3h immersion a compact layer of HA was observed at the surface of the samples. The obtained results suggest potential applicability of resulted new porous crosslinked polymeric materials as temporary bone void fillers. PMID:25491802

  13. Effect of Buffers on Aqueous Solute-Exclusion Zones around Ion-Exchange Resins

    PubMed Central

    Zheng, Jian-ming; Wexler, Adam

    2009-01-01

    Interaction between charged surfaces in aqueous solution is a fundamental feature of colloid science. Theoretically, surface potential falls to half its value at a distance equal to a Debye length, which is typically on the order of tens to hundreds of nanometers. This potential prevents colloids from aggregating. On the other hand, long-range surface effects have been frequently reported. Here we report additional long-range effects. We find that charged latex particles in buffer solutions are uniformly excluded from several-hundred-micron-thick shells surrounding ion-exchange beads. Exclusion is observed whether the beads are charged similarly or oppositely to the particles. Hence, electrostatic interactions between bead and microsphere do not cause particle exclusion. Rather, exclusion may be the consequence of water molecules re-orienting to produce a more ordered structure, which then excludes the particles. PMID:19185312

  14. SEPARATION OF PLUTONIUM FROM AQUEOUS SOLUTIONS BY ION-EXCHANGE

    DOEpatents

    Schubert, J.

    1958-06-01

    A process is described for the separation of plutonium from an aqueous solution of a plutonium salt, which comprises adding to the solution an acid of the group consisting of sulfuric acid, phosphoric acid, and oxalic acid, and mixtures thereof to provide an acid concentration between 0.0001 and 1 M, contacting the resultant solution with a synthetic organic anion exchange resin, and separating the aqueous phase and the resin which contains the plutonium.

  15. Characterization of Group V Dubnium Homologs on DGA Extraction Chromatography Resin from Nitric and Hydrofluoric Acid Matrices

    SciTech Connect

    Despotopulos, J D; Sudowe, R

    2012-02-21

    somewhere between Nb and Pa. Much more recent studies have examined the properties of Db from HNO{sub 3}/HF matrices, and suggest Db forms complexes similar to those of Pa. Very little experimental work into the behavior of element 114 has been performed. Thermochromatography experiments of three atoms of element 114 indicate that the element 114 is at least as volatile as Hg, At, and element 112. Lead was shown to deposit on gold at temperatures about 1000 C higher than the atoms of element 114. Results indicate a substantially increased stability of element 114. No liquid phase studies of element 114 or its homologs (Pb, Sn, Ge) or pseudo-homologs (Hg, Cd) have been performed. Theoretical predictions indicate that element 114 is should have a much more stable +2 oxidation state and neutral state than Pb, which would result in element 114 being less reactive and less metallic than Pb. The relativistic effects on the 7p{sub 1/2} electrons are predicted to cause a diagonal relationship to be introduced into the periodic table. Therefore, 114{sup 2+} is expected to behave as if it were somewhere between Hg{sup 2+}, Cd{sup 2+}, and Pb{sup 2+}. In this work two commercially available extraction chromatography resins are evaluated, one for the separation of Db homologs and pseudo?homologs from each other as well as from potential interfering elements such as Group IV Rf homologs and actinides, and the other for separation of element 114 homologs. One resin, Eichrom's DGA resin, contains a N,N,N',N'-tetra-n-octyldiglycolamide extractant, which separates analytes based on both size and charge characteristics of the solvated metal species, coated on an inert support. The DGA resin was examined for Db chemical systems, and shows a high degree of selectivity for tri-, tetra-, and hexavalent metal ions in multiple acid matrices with fast kinetics. The other resin, Eichrom's Pb resin, contains a di-t-butylcyclohexano 18-crown-6 extractant with isodecanol solvent, which separates

  16. 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.

  17. Reduction of aldehydes and hydrogen cyanide yields in mainstream cigarette smoke using an amine functionalised ion exchange resin

    PubMed Central

    2011-01-01

    Background Cigarette smoking is a well recognized cause of diseases such as lung cancer, chronic obstructive pulmonary disease and cardiovascular disease. Of the more than 5000 identified species in cigarette smoke, at least 150 have toxicological activity. For example, formaldehyde and acetaldehyde have been assigned as Group 1 and Group 2B carcinogens by IARC, and hydrogen cyanide has been identified as a respiratory and cardiovascular toxicant. Active carbon has been shown to be an effective material for the physical adsorption of many of the smoke volatile species. However, physical adsorption of acetaldehyde, formaldehyde and also hydrogen cyanide from smoke is less effective using carbon. Alternative methods for the removal of these species from cigarette smoke are therefore of interest. A macroporous, polystyrene based ion-exchange resin (Diaion®CR20) with surface amine group functionality has been investigated for its ability to react with aldehydes and HCN in an aerosol stream, and thus selectively reduce the yields of these compounds (in particular formaldehyde) in mainstream cigarette smoke. Results Resin surface chemistry was characterized using vapour sorption, XPS, TOF-SIMS and 15N NMR. Diaion®CR20 was found to have structural characteristics indicating weak physisorption properties, but sufficient surface functionalities to selectively remove aldehydes and HCN from cigarette smoke. Using 60 mg of Diaion®CR20 in a cigarette cavity filter gave reductions in smoke formaldehyde greater than 50% (estimated to be equivalent to >80% of the formaldehyde present in the smoke vapour phase) independent of a range of flow rates. Substantial removal of HCN (>80%) and acetaldehyde (>60%) was also observed. The performance of Diaion®CR20 was found to be consistent over a test period of 6 months. The overall adsorption for the majority of smoke compounds measured appeared to follow a pseudo-first order approximation to second order kinetics. Conclusions This

  18. Amino acid analysis

    NASA Technical Reports Server (NTRS)

    Winitz, M.; Graff, J. (Inventor)

    1974-01-01

    The process and apparatus for qualitative and quantitative analysis of the amino acid content of a biological sample are presented. The sample is deposited on a cation exchange resin and then is washed with suitable solvents. The amino acids and various cations and organic material with a basic function remain on the resin. The resin is eluted with an acid eluant, and the eluate containing the amino acids is transferred to a reaction vessel where the eluant is removed. Final analysis of the purified acylated amino acid esters is accomplished by gas-liquid chromatographic techniques.

  19. A novel approach to measure elemental concentrations in cation exchange resins using XRF-scanning technique, and its potential in water pollution studies

    NASA Astrophysics Data System (ADS)

    Huang, Jyh-Jaan; Lin, Sheng-Chi; Löwemark, Ludvig; Liou, Ya-Hsuan; Chang, Queenie; Chang, Tsun-Kuo; Wei, Kuo-Yen; Croudace, Ian W.

    2016-04-01

    X-ray fluorescence (XRF) core-scanning is a fast, and convenient technique to assess elemental variations for a wide variety of research topics. However, the XRF scanning counts are often considered a semi-quantitative measurement due to possible absorption or scattering caused by down core variability in physical properties. To overcome this problem and extend the applications of XRF-scanning to water pollution studies, we propose to use cation exchange resin (IR-120) as an "elemental carrier", and to analyze the resins using the Itrax-XRF core scanner. The use of resin minimizes the matrix effects during the measurements, and can be employed in the field in great numbers due to its low price. Therefore, the fast, and non-destructive XRF-scanning technique can provide a quick and economical method to analyze environmental pollution via absorption in the resin. Five standard resin samples were scanned by the Itrax-XRF core scanner at different exposure times (1 s, 5 s, 15 s, 30 s, 100 s) to allow the comparisons of scanning counts with the absolute concentrations. The regression lines and correlation coefficients of elements that are generally used in pollution studies (Ca, Ti, Cr, Ni, Cu, Zn, and Pb) were examined for the different exposure times. The result shows that within the test range (from few ppm to thousands ppm), the correlation coefficients are all higher than 0.97, even at the shortest exposure time (1 s). Therefore, we propose to use this method in the field to monitor for example sewage disposal events. The low price of resin, and fast, multi elements and precise XRF-scanning technique provide a viable, cost- and time-effective approach that allows large sample numbers to be processed. In this way, the properties and sources of wastewater pollution can be traced for the purpose of environmental monitoring and environmental forensics.

  20. Method of uranium reclamation from aqueous systems by reactive ion exchange. [US DOE patent application; anion exchange resin of copolymerized divinyl-benzene and styrene having quarternary ammonium groups and bicarbonate ligands

    DOEpatents

    Maya, L.

    1981-11-05

    A reactive ion exchange method for separation and recovery of values of uranium, neptunium, plutonium, or americium from substantially neutral aqueous systems of said metals comprises contacting said system with an effective amount of a basic anion exchange resin of copolymerized divinyl-benzene and styrene having quarternary ammonium groups and bicarbonate ligands to achieve nearly 100% sorption of said actinyl ion onto said resin and an aqueous system practically free of said actinyl ions. The method is operational over an extensive range of concentrations from about 10/sup -6/ M to 1.0 M actinyl ion and a pH range of about 4 to 7. The method has particulr application to treatment of waste streams from Purex-type nuclear fuel reprocessing facilities and hydrometallurgical processes involving U, Np, P, or Am.

  1. An investigation of the applicability of the new Reillex{trademark}-HPQ anion exchange resin system for technetium/rhenium and uranium in the Hanford waste tanks. Milestone 4 final report

    SciTech Connect

    Ashley, K.R.; Ball, J.R.; Cobb, S.L.; Adams, J.M.; Young, D.A.

    1994-09-30

    Results of the measurements of the exchange capacity and K{sub d} values for ReO{sub 4}{sup {minus}} on Reillex{trademark}-HPQ as a function of nitric acid and hydroxide concentration, temperature, and ten months time will be reported. Results of the breakthrough volumes for UO{sub 2}{sup 2+} on Reillex-HPQ chromatography columns as a function of carbonate ion concentration in high nitrate ion concentrations and various column sizes will be reported. Individual sections of this report describe the following: the sorption behavior of ReO{sub 4}{sup {minus}} on the Reillex-HPQ between pH 2 and 12 in 1.00 M NaNO{sub 3}; results of the measurements of the K{sub d} values for ReO{sub 4}{sup {minus}} on Reillex-HPQ and on Reillex-HP as a function of nitrate and hydroxide ion concentrations; the sorption behavior of ReO{sub 4}{sup {minus}} on Reillex-HPQ resin in base with time as a variable; the results of the early attempts at determining the K{sub d} values for Na{sub 4}UO{sub 2}(CO{sub 3}){sub 3} on Reillex-HPQ resin; and the breakthrough of UO{sub 2}(NO{sub 3}){sub 2} in varying nitric acid solutions on Reillex-HPQ columns.

  2. Metal-Carbon Hybrid Electrocatalysts Derived from Ion-Exchange Resin Containing Heavy Metals for Efficient Hydrogen Evolution Reaction.

    PubMed

    Zhou, Yucheng; Zhou, Weijia; Hou, Dongman; Li, Guoqiang; Wan, Jinquan; Feng, Chunhua; Tang, Zhenghua; Chen, Shaowei

    2016-05-01

    Transition metal-carbon hybrids have been proposed as efficient electrocatalysts for hydrogen evolution reaction (HER) in acidic media. Herein, effective HER electrocatalysts based on metal-carbon composites are prepared by controlled pyrolysis of resin containing a variety of heavy metals. For the first time, Cr2 O3 nanoparticles of 3-6 nm in diameter homogeneously dispersed in the resulting porous carbon framework (Cr-C hybrid) is synthesized as efficient HER electrocatalyst. Electrochemical measurements show that Cr-C hybrids display a high HER activity with an onset potential of -49 mV (vs reversible hydrogen electrode), a Tafel slope of 90 mV dec(-1) , a large catalytic current density of 10 mA cm(-2) at -123 mV, and the prominent electrochemical durability. X-ray photoelectron spectroscopic measurements confirm that electron transfer occurs from Cr2 O3 into carbon, which is consistent with the reported metal@carbon systems. The obtained correlation between metals and HER activities may be exploited as a rational guideline in the design and engineering of HER electrocatalysts. PMID:27061759

  3. Enzymatic hydrolysis and physical characterization of commercial celluloses and cellulose-based ion-exchange powdered mixed resins.

    PubMed

    Clarkin, S D; Clesceri, L S

    2002-12-01

    Commercial celluloses (BH20, Epicote, FC+) and their cellulose-containing powdered mixed resins (PMR) were evaluated using enzymatic and physical methods. Samples were hydrolyzed with purified Trichoderma viride cellulase extract and measured for released reducing sugar using the dinitrosalicylic acid method. Physical characterization was performed with gross specific surface areas (GSSA) and relative crystalline indices (RCI). In addition, FC+ was exposed to physical and chemical processing commonly encountered in spent PMR processing to determine potential effects on reducing sugar release in high intensity containers. Reducing sugar released from the celluloses by T. viride cellulase ranged from 135.37 to 244.48 mg day(-1); the celluloses were highly crystalline, ranging from 82.47 to 84.57%; and the GSSA medians for the celluloses ranged from 1,298.60 cm(2) g(-1) to 2,493.20 cm(2) g(-1). Most processing treatments on the FC+ reduced the amount of reducing sugar released and increased RCI. Cellulose hydrolysis rates did not show a strong correlation with the physical characterization. These results suggest that (1) celluloses and PMR can serve as abundant sources of bioavailable carbon in water treatment systems, and (2) the use of correlative physical characteristics to evaluate a cellulose-based commercial product may not accurately predict microbial activity; a complementary microbial test such as cellulose hydrolysis with cellulase may prove useful. PMID:12466892

  4. Relative sensitivity of five benthic invertebrate species to reference toxicants and resin-acid contaminated sediments

    SciTech Connect

    Hickey, C.W.; Martin, M.L.

    1995-08-01

    Five sediment-dwelling native New Zealand freshwater invertebrate species (amphipod, Chaetocorophium c.f. lucasi; clam, Sphaerium novaezelandiae; oligochaete, Lumbriculus variegatus; tanaid, Tanais standfordi; and the burrowing mayfly, Ichthybotus hudsoni) were assessed for their suitability for sediment toxicity testing by comparison of sensitivity to reference toxicants [phenol and pentachlorophenol (PCP)] and contaminated sediments. The 96-h EC50 values at 20 C showed a greater range in test sensitivity for phenol (30-fold range) from the most sensitive test, amphipod (8.1 mg/L), to the least sensitive one, clam (243 mg/L), compared with PCP (14-fold range), with amphipod the most sensitive test species (0.13 mg/L) and tanaid the least sensitive (1.8 mg/L). Clam reburial was a more sensitive end point than was lethality for phenol (by 20-fold) and PCP (by 2.4-fold). Four of the test species, excluding the tanaid, showed good 10-d survival in reference muds ({ge}87%) but lower survival in sand sediments ({ge}79%). Bleached kraft mill sediment containing high resin-acid concentrations (total 1,900 mg/kg dry weight) showed significant reductions in amphipod survival (15%), clam reburial (30%), and oligochaete survival (17%), and reproduction (49%). Amphipods, clams, and oligochaetes were the most promising species for sublethal test development.

  5. Atmospheric Ionic Deposition in Tropical Sites of Central Sulawesi Determined by Ion Exchange Resin Collectors and Bulk Water Collector.

    PubMed

    Köhler, S; Jungkunst, H F; Gutzler, C; Herrera, R; Gerold, G

    2012-09-01

    In the light of global change, the necessity to monitor atmospheric depositions that have relevant effects on ecosystems is ever increasing particularly for tropical sites. For this study, atmospheric ionic depositions were measured on tropical Central Sulawesi at remote sites with both a conventional bulk water collector system (BWS collector) and with a passive ion exchange resin collector system (IER collector). The principle of IER collector to fix all ionic depositions, i.e. anions and cations, has certain advantages referring to (1) post-deposition transformation processes, (2) low ionic concentrations and (3) low rainfall and associated particulate inputs, e.g. dust or sand. The ionic concentrations to be measured for BWS collectors may easily fall below detection limits under low deposition conditions which are common for tropical sites of low land use intensity. Additionally, BWS collections are not as independent from the amount of rain fallen as are IER collections. For this study, the significant differences between both collectors found for nearly all measured elements were partly correlated to the rainfall pattern, i.e. for calcium, magnesium, potassium and sodium. However, the significant differences were, in most cases, not highly relevant. More relevant differences between the systems were found for aluminium and nitrate (434-484 %). Almost five times higher values for nitrate clarified the advantage of the IER system particularly for low deposition rate which is one particularity of atmospheric ionic deposition in tropical sites of extensive land use. The monthly resolution of the IER data offers new insights into the temporal distribution of annual ionic depositions. Here, it did not follow the tropical rain pattern of a drier season within generally wet conditions. PMID:22865942

  6. Enhanced Ionic Conductivity and Power Generation Using Ion-Exchange Resin Beads in a Reverse-Electrodialysis Stack.

    PubMed

    Zhang, Bopeng; Gao, Haiping; Chen, Yongsheng

    2015-12-15

    Reverse electrodialysis (RED) is a promising technique for harvesting energy by mixing seawater with river water. The energy production is usually limited by ionic conductivity in dilute compartments of a RED system. Novel tests were conducted in this research, which used ion-exchange resin beads (IERB) to replace nonconductive spacer fabrics in RED compartments with dilute NaCl solution in a modified stack containing Fumasep FKS and Fumasep FAS membranes. We compared the conductivity of an IERB packed bed with that of an inert glass-beads-packed bed as a control to confirm IERB's effectiveness. When applied in a RED system, IERB decreased the stack resistance by up to 40%. The maximum gross power density improved by 83% in the RED stack compared to that in a regular RED stack at 1.3 cm/s average linear flow velocity. IERB-filled stack resistance was modeled. The model results fit well with experimental data, thereby confirming the effectiveness of the new approach presented here. The net power density is also estimated based on the measured pressure drop and pumping energy model. Both gross and net power density was improved by over 75% at higher flow rate. A net power density of 0.44 W/m(2) was achieved at a cell thickness of 500 μm. To the best of our knowledge, this research is the first to study the impact of IERB on power generation and establishes a new approach to improving the power performance of a RED system. PMID:26560232

  7. ELUTION OF URANIUM FROM RESIN

    DOEpatents

    McLEan, D.C.

    1959-03-10

    A method is described for eluting uranium from anion exchange resins so as to decrease vanadium and iron contamination and permit recycle of the major portion of the eluats after recovery of the uranium. Diminution of vanadium and iron contamination of the major portion of the uranium is accomplished by treating the anion exchange resin, which is saturated with uranium complex by adsorption from a sulfuric acid leach liquor from an ore bearing uranium, vanadium and iron, with one column volume of eluant prepared by passing chlorine into ammonium hydroxide until the chloride content is about 1 N and the pH is about 1. The resin is then eluted with 8 to 9 column volumes of 0.9 N ammonium chloride--0.1 N hydrochloric acid solution. The eluants are collected separately and treated with ammonia to precipitate ammonium diuranate which is filtered therefrom. The uranium salt from the first eluant is contaminated with the major portion of ths vanadium and iron and is reworked, while the uranium recovered from the second eluant is relatively free of the undesirable vanadium and irons. The filtrate from the first eluant portion is discarded. The filtrate from the second eluant portion may be recycled after adding hydrochloric acid to increase the chloride ion concentration and adjust the pH to about 1.

  8. Extraction and isolation of TPE from other elements on ion exchangers in aqueous and aqueous-organic solutions of phosphoric acid

    SciTech Connect

    Guseva, L.I.; Tikhomirova, G.S.; Stepushkina, V.V.

    1988-07-01

    The behavior of Am-Es and other actinides on anion and cation exchange resins in aqueous and aqueous-organic solutions of phosphoric acid has been studied in a wide range of concentration of various components of the solution. The sorptivity of transplutonium elements (TPE) on anion exchangers from dilute H/sub 3/PO/sub 4/ with a concentration less than or equal to 1 M in presence of organic solvents (alcohols, ketones, etc.) and on cation exchangers from concentrated H/sub 3/PO/sub 4/ has been found to be significant. The possibility of use of phosphoric acid solutions for isolation of TPE from Th, Pa, U, Np, Pu, and Zr and separation of TPE in different oxidation states in presence of a high-purity oxidant has been shown.

  9. Synthesis and evaluation of different thio-modified cellulose resins for the removal of mercury (II) ion from highly acidic aqueous solutions.

    PubMed

    Takagai, Yoshitaka; Shibata, Atsushi; Kiyokawa, Shigemi; Takase, Tsugiko

    2011-01-15

    Seven different types of thio- and/or amine-modified cellulose resin materials were synthesized and their mercury (II) ion adsorption properties determined. All seven resins showed good mercury (II) adsorption capability in the more neutral pH regions. However, the o-benzenedithiol- and o-aminothiophenol-modified cellulosic resins were found to be very effective in removing mercury (II) ions from strongly acidic media. For example, 93.5-100% mercury (II) ion recoveries from very acid aqueous solutions (nitric acid concentration ranged from 0.1 to 2.0 mol/L) were obtained using the o-benzenedithiol-modified resin while recoveries ranged from ca. 50% to 60% for the o-aminothiophenol-modified resin. An adsorption capacity of 23 mg (as Hg atoms) per gram of resin was observed for the o-benzenedithiol-modified cellulose in the presence of 1.0 mol/L nitric acid. This same resin shows very good selectivity for mercury (II) as only ruthenium (II) also somewhat adsorbed onto it out of 14 other metal ions studied (Ag(+), Al(3+), As(3+), Co(2+), Cd(2+), Cr(3+), Cu(2+), Fe(3+), Mn(2+), Ni(2+), Pt(2+), Pb(2+), Ru(2+), and Zn(2+)). PMID:20974469

  10. Investigation of the swelling behavior of cationic exchange resins saturated with Na{sup +} ions in a C{sub 3}S paste

    SciTech Connect

    Lafond, E.; Cau Dit Coumes, C.; Gauffinet, S.; Chartier, D.; Le Bescop, P.; Stefan, L.; Nonat, A.

    2015-03-15

    Ion exchange resins (IERs) are widely used by the nuclear industry to decontaminate radioactive effluents. Spent products are usually encapsulated in cementitious materials. However, the solidified waste form can exhibit strong expansion, possibly leading to cracking, if the appropriate binder is not used. In this work, the interactions between cationic resins in the Na{sup +} form and tricalcium silicate are investigated during the early stages of hydration in order to gain a better understanding of the expansion process. It is shown that the IERs exhibit a transient swelling of small magnitude due to the decrease in the osmotic pressure of the external solution. This expansion, which occurs just after setting, is sufficient to damage the material which is poorly consolidated for several reasons: low degree of hydration, precipitation of poorly cohesive sodium-bearing C–S–H, and very heterogeneous microstructure with zones of high porosity.

  11. The erosion kinetics of conventional and resin-modified glass-ionomer luting cements in acidic buffer solutions.

    PubMed

    Hazar-Yoruc, Binnaz; Bavbek, Andac Barkin; Özcan, Mutlu

    2012-01-01

    This study investigated the erosion kinetics of conventional and resin-modified glass-ionomer luting cements in acidic buffer solutions as a function of time. Disc shaped specimens were prepared from conventional (Ketac-Cem: KTC) and resin-modified glass ionomer cements (Fuji Plus: FP) and immersed in three acidic buffer solutions (0.01 M) namely, acetic acid/sodium acetate (AA(B)), lactic acid/sodium lactate (LA(B)) and citric acid/sodium citrate (CA(B)) with a constant pH of 4.1 and stored for 1, 8, 24, 48, 80, 120 and 168 h. F concentration was determined using ion-specific electrode. Si, Ca and Al concentrations were determined by atomic absorption spectroscopy. Ca, Al, Si and F solubility rates in both FP and KTC were the highest in CA(B) solution. The erosion rates of both FP and KTC in all buffer solutions increased as a function of immersion time. The amount of F eluted from FP was more than that of KTC. The total amount of elements released from FP was less than KTC in all solutions. PMID:23207217

  12. Inhibition of Streptococcus mutans biofilm formation on composite resins containing ursolic acid

    PubMed Central

    Kim, Soohyeon; Song, Minju; Roh, Byoung-Duck; Park, Sung-Ho

    2013-01-01

    Objectives To evaluate the inhibitory effect of ursolic acid (UA)-containing composites on Streptococcus mutans (S. mutans) biofilm. Materials and Methods Composite resins with five different concentrations (0.04, 0.1, 0.2, 0.5, and 1.0 wt%) of UA (U6753, Sigma Aldrich) were prepared, and their flexural strengths were measured according to ISO 4049. To evaluate the effect of carbohydrate source on biofilm formation, either glucose or sucrose was used as a nutrient source, and to investigate the effect of saliva treatment, the specimen were treated with either unstimulated whole saliva or phosphate-buffered saline (PBS). For biofilm assay, composite disks were transferred to S. mutans suspension and incubated for 24 hr. Afterwards, the specimens were rinsed with PBS and sonicated. The colony forming units (CFU) of the disrupted biofilm cultures were enumerated. For growth inhibition test, the composites were placed on a polystyrene well cluster, and S. mutans suspension was inoculated. The optical density at 600 nm (OD600) was recorded by Infinite F200 pro apparatus (TECAN). One-way ANOVA and two-way ANOVA followed by Bonferroni correction were used for the data analyses. Results The flexural strength values did not show significant difference at any concentration (p > 0.01). In biofilm assay, the CFU score decreased as the concentration of UA increased. The influence of saliva pretreatment was conflicting. The sucrose groups exhibited higher CFU score than glucose group (p < 0.05). In bacterial growth inhibition test, all experimental groups containing UA resulted in complete inhibition. Conclusions Within the limitations of the experiments, UA included in the composite showed inhibitory effect on S. mutans biofilm formation and growth. PMID:23741708

  13. REMOVING BARIUM AND RADIUM THROUGH CALCIUM CATION EXCHANGE

    EPA Science Inventory

    The removal of barium (Ba) and radium (Ra), which are found in many groundwater sources, was achieved in laboratory studies with an ion exchange process. In the studies, a strong acid resin in the calcium form effectively removed Ba(+2) and Ra (+2) to meet standards. The resin wa...

  14. Thermodynamic modeling of Cl(-), NO3(-) and SO4(2-) removal by an anion exchange resin and comparison with Dubinin-Astakhov isotherms.

    PubMed

    Dron, Julien; Dodi, Alain

    2011-03-15

    The removal of chloride, nitrate, and sulfate ions from wastewaters by a macroporous ion-exchange resin is studied through the experimental results obtained for six ion exchange systems, OH(-)/Cl(-), OH(-)/NO3(-), OH(-)/SO4(2-), and HCO3(-)/Cl(-), Cl(-)/NO3(-), Cl(-)/SO4(2-). The results are described through thermodynamic modeling, considering either an ideal or a nonideal behavior of the ionic species in the liquid and solid phases. The nonidealities are determined by the Davies equation and Wilson equations in the liquid and solid phases, respectively. The results show that the resin has a strong affinity for all the target ions, and the order of affinity obtained is OH(-) < HCO3(-) < Cl(-) < NO3(-) < SO4(2-). The calculation of the changes in standard Gibbs free energies (ΔG(0)) shows that even though HCO3(-) has a lower affinity to the resin, it may affect the removal of Cl(-), and in the same way that Cl(-) may affect the removal of NO3(-) and SO4(2-). The application of nonidealities in the thermodynamic model leads to an improved fit of the model to the experimental data with average relative deviations below 1.5% except for the OH(-)/SO4(2-) system. On the other hand, considering ideal or nonideal behaviors has no significant impact on the determination of the selectivity coefficients. The thermodynamic modeling is also compared with the Dubinin-Astakhov adsorption isotherms obtained for the same ion exchange systems. Surprisingly, the latter performs significantly better than the ideal thermodynamic model and nearly as well as the nonideal thermodynamic model. PMID:21332215

  15. Selected resin acids in effluent and receiving waters derived from a bleached and unbleached kraft pulp and paper mill

    USGS Publications Warehouse

    Quinn, B.P.; Booth, M.M.; Delfino, J.J.; Holm, S.E.; Gross, T.S.

    2003-01-01

    Water samples were collected on three dates at 24 sites influenced by effluent from Georgia-Pacific's Palatka Pulp and Paper Mill Operation, a bleached and unbleached kraft mill near Palatka, Florida, USA. The sampling sites were located within the mill retention ponds, Rice Creek, and the St. John's River. Samples were analyzed by gas chromatography-mass spectrometry for abietic, dehydroabietic, and isopimaric acids, all of which are potentially toxic by-products of pulp production. Isopimaric acid concentrations greater than 12 mg/L were measured at the mill's effluent outfall but were less than 20 ??g/L at the end of Rice Creek. This result indicates that the waters of Rice Creek provide dilution or conditions conducive for degradation or sorption of these compounds. Large differences in resin acid concentrations were observed between sampling events. In two sampling events, the maximum observed concentrations were less than 2 mg/L for each analyte. In a third sampling event, all of the compounds were detected at concentrations greater than 10 mg/L. Data from the three sample dates showed that resin acid concentrations were below 20 ??g/L before the confluence of Rice Creek and the St. John's River in all cases.

  16. Nitric acid-organic mixtures surveyed for use in separation by anion exchange methods

    NASA Technical Reports Server (NTRS)

    Bloomquist, C. A. A.; Faris, J. P.; Stewart, D. C.

    1968-01-01

    Column elution-spectrographic analysis technique compares certain solvents directly to the methanol system, using inert rare earths instead of actinides. Distribution ratios for americium between 90 percent solvent, 10 percent 5 M nitric acid and Dowex 1 nitrate form resin for a large group of organics miscible in water was determined.

  17. Biocidal quaternary ammonium resin

    NASA Technical Reports Server (NTRS)

    Janauer, G. E.

    1983-01-01

    Activated carbon (charcoal) and polymeric resin sorbents are widely used in the filtration and treatment of drinking water, mainly to remove dissolved organic and inorganic impurities and to improve the taste. Earlier hopes that activated carbon might "disinfect' water proved to be unfounded. The feasibility of protecting against microbial infestation in charcoal and resin beds such as those to be incorporated into total water reuse systems in spacecraft was investigated. The biocidal effect of IPCD (insoluable polymeric contact disinfectants) in combination with a representative charcoal was assessed. The ion exchange resins (IPCD) were shown to adequately protect charcoal and ion exchange beds.

  18. Preparation of molecularly imprinted cross-linked chitosan/glutaraldehyde resin for enantioselective separation of L-glutamic acid.

    PubMed

    Monier, M; El-Sokkary, A M A

    2010-08-01

    In the present study, separation of L-glutamic acid from dilute aqueous solution by solid-phase extraction based on molecular imprinting technique using cross-linked chitosan/glutaraldehyde resin was investigated. L-Glutamic acid imprinted cross-linked chitosan (LGIC) was prepared by cross-linking of chitosan by glutaraldehyde cross-linker, in the presence of L-glutamic acid. Non-imprinted cross-linked chitosan (NIC) as control was also prepared by the same procedure in the absence of template molecules. The morphological structures of both LGIC and NIC were examined by scanning electron microscope (SEM). LGIC particles were applied to determine the optimum operational condition for l-glutamic acid separation from dilute aqueous solution. In adsorption step, optimum pH and retention time were 5.5 and 100 min, while corresponding values in extraction step were 2.5 and 60 min, respectively. The adsorption isotherms indicated that the maximum adsorption capacities of L- and D-glutamic acid on LGIC were 42+/-0.8 and 26+/-1.2mg/g, respectively, while in case of NIC, both L- and D-glutamic acid present the same maximum adsorption capacity 7+/-0.6 mg/g, which confirm that the molecular imprinting technique creates an enantioselectivity of LGIC toward L-glutamic acid. In addition, chiral resolution of l-, d-glutamic acid racemic mixture was carried out using column of LGIC. PMID:20441776

  19. Vapor-phase esterification of acetic acid with ethanol catalyzed by a macroporous sulfonated styrene-divinylbenzene (20%) resin

    SciTech Connect

    Gimenez, J.; Costa, J.; Cervera, S.

    1987-02-01

    The kinetics of the vapor-phase (85-120/sup 0/C) esterification of acetic acid with ethyl alcohol, at atmospheric pressure, catalyzed by a macroporous sulfonated styrene-divinylbenzene (DVB;20%) resin, has been studied. A simple first-order model (r = kp/sub 1/) fits experimental kinetic data properly for a constant reactants ratio. Discussion by means of L-H-H-W models shows that the rate-controlling step is the surface reaction with a single-site mechanism. The apparent activation energy is 4000 cal/mol.

  20. Eichrom`s Diphonix{reg_sign} resin: Production-scale applications in radioactive waste treatment and iron control in copper electrowinning

    SciTech Connect

    Gula, M.J.; Chang, F.; Dreisinger, D.B.; Horwitz, E.P.

    1997-12-31

    Eichrom`s Diphonix{reg_sign} resin has been phased through synthetic scale-up, pilot testing, and production installation in radioactive waste treatment and hydrometallurgical applications. The geminal diphosphonic acid groups of Diphonix resin allow selective retention by cation-exchange and/or chelation. The resin is effective at low pH where sulfonic and carboxylic acid resins are ineffective. Diphonix resin has been used in nuclear facilities to reduce actinide concentrations in radioactive waste effluents and to reduce waste volumes. The high retention of iron(III) by Diphonix resin in acidic sulfate media has led to an installation capable of removing one ton of iron per day from a copper electrowinning stream. This iron control process diminishes cobalt losses in the electrowinning circuit and significantly reduces operating costs. The authors will discuss the development of these Diphonix resin applications.

  1. An Efficient Protocol for Preparation of Gallic Acid from Terminalia bellirica (Gaertn.) Roxb by Combination of Macroporous Resin and Preparative High-Performance Liquid Chromatography.

    PubMed

    Zou, Denglang; Chen, Tao; Chen, Chen; Li, Hongmei; Liu, Yongling; Li, Yulin

    2016-08-01

    In this article, macroporous resin column chromatography and preparative high-performance liquid chromatography were applied for preparation of gallic acid from Terminalia bellirica (Gaertn.) Roxb. In the first step, six kinds of resins were investigated by adsorption and desorption tests and AB-8 macroporous resin was selected for the enrichment of gallic acid. As a result, 20 g of gallic acid at a purity of 71% could be separated from 100 g of crude extract in which the content of gallic acid was 16.7% and the recovery of gallic acid reached 85.0%. In the second step, preparative high-performance liquid chromatography was selected to purify gallic acid. As a result, 640 mg of gallic acid at a purity of 99.1% was obtained from 1 g of sample in 35 min. The results demonstrated that macroporous resin coupled with preparative high-performance liquid chromatography was suitable for preparation of gallic acid from T. bellirica (Gaertn.) Roxb. PMID:27076561

  2. Separation of berkelium (IV) from trivalent transplutonium elements on ion-exchangers in solutions of phosphoric acid

    SciTech Connect

    Guseva, L.I.; Stepushkina, V.V.; Tikhomirova, G.S.

    1985-01-01

    The dependences of Am, Cm, Bk, Cf and Es behavior on anion- and cation-exchangers in solutions of 0.1-8.0 M H/sub 3/PO/sub 4/ on acid concentration and oxidant content in solution (KBrO/sub 3/) or in resin (PbO/sub 2/) have been studied. Significant differences in distribution coefficients of Bk and other transplutonium elements (TPE) have been found that can be explained by Bk oxidation to the tetravalent state. A simple and effective method of Bk (IV) separation from trivalent TPE has been developed. The method was applied to the isolation of isotopes Bk-249 and Bk-250; the purification factor of Bk (IV) from other TPE is 10/sup 4/-10/sub 6/ per cycle. The possibility of Bk separation from bromate and phosphate ions by its sorption on a cation-exchanger from diluted H/sub 3/PO/sub 4/ solutions with subsequent desorption by the mineral acid has been shown. 20 references, 8 figures.

  3. Cleanup of TMI-2 demineralizer resins

    SciTech Connect

    Bond, W.D.; King, L.J.; Knauer, J.B.; Hofstetter, K.J.; Thompson, J.D.

    1985-01-01

    Radiocesium is being removed from Demineralizers A and B (DA and DB by a process that was developed from laboratory tests on small samples of resin from the demineralizers. The process was designed to elute the radiocesium from the demineralizer resins and then to resorb it onto the zeolite ion exchangers contained in the Submerged Demineralizer System (SDS). The process was also required to limit the maximum cesium activities in the resin eluates (SDS feeds) so that the radiation field surrounding the pipelines would not be excessive. The process consists of 17 stages of batch elution. In the initial stage, the resin is contacted with 0.18 M boric acid. Subsequent stages subject the resin to increasing concentrations of sodium in NaH/sub 2/BO/sub 3/-H/sub 3/BO/sub 3/ solution (total B = 0.35 M) and then 1 M sodium hydroxide in the final stages. Results on the performance of the process in the cleanup of the demineralizers at TMI-2 are compared to those obtained from laboratory tests with small samples of the DA and DB resins. To date, 15 stages of batch elution have been completed on the demineralizers at TMI-2 which resulted in the removal of about 750 Ci of radiocesium from DA and about 3300 Ci from DB.

  4. A Robust Epoxy Resins @ Stearic Acid-Mg(OH)2 Micronanosheet Superhydrophobic Omnipotent Protective Coating for Real-Life Applications.

    PubMed

    Si, Yifan; Guo, Zhiguang; Liu, Weimin

    2016-06-29

    Superhydrophobic coating has extremely high application value and practicability. However, some difficult problems such as weak mechanical strength, the need for expensive toxic reagents, and a complex preparation process are all hard to avoid, and these problems have impeded the superhydrophobic coating's real-life application for a long time. Here, we demonstrate one kind of omnipotent epoxy resins @ stearic acid-Mg(OH)2 superhydrophobic coating via a simple antideposition route and one-step superhydrophobization process. The whole preparation process is facile, and expensive toxic reagents needed. This omnipotent coating can be applied on any solid substrate with great waterproof ability, excellent mechanical stability, and chemical durability, which can be stored in a realistic environment for more than 1 month. More significantly, this superhydrophobic coating also has four protective abilities, antifouling, anticorrosion, anti-icing, and flame-retardancy, to cope with a variety of possible extreme natural environments. Therefore, this omnipotent epoxy resins @ stearic acid-Mg(OH)2 superhydrophobic coating not only satisfies real-life need but also has great application potential in many respects. PMID:27265834

  5. Nanostructured gadolinium-doped ceria microsphere synthesis from ion exchange resin: Multi-scale in-situ studies of solid solution formation

    SciTech Connect

    Caisso, Marie; Lebreton, Florent; Horlait, Denis; Neuville, Daniel R.; Dardenne, Kathy; Rothe, Jörg; Delahaye, Thibaud

    2014-10-15

    In the current nano-sized material revolution, the main limitations to a large-scale deployment of nanomaterials involve health concerns related to nano-dissemination via air. Developing new chemical routes benefiting from nano-size advantages while avoiding their hazards could overcome these limitations. Addressing this need, a chemical route leading to soft nano-particle agglomerates, i.e., macroscopic precursors presenting the ability to be decomposed into nano-sized materials, was developed and applied to Ce{sub 0.8}Gd{sub 0.2}O{sub 2−δ}. Using cerium/gadolinium-loaded ion exchange resin, the Ce{sub 0.8}Gd{sub 0.2}O{sub 2−δ} solid solution formation as a function of temperature was studied in-situ through X-ray diffraction, X-ray absorption spectroscopy and Raman spectroscopy. Temperatures corresponding to the organic skeleton decomposition and to the mixed oxide crystallization were identified. An optimal heat treatment, leading to nanostructured soft agglomerates, was established. Microsphere processing capabilities were evaluated and particle size distribution measurements were recorded. A very low fracture strength was calculated, and a nanometric particle size distribution (170 nm) was determined. - Graphical abstract: The elaboration of micro-spherical precursors leading to the formation of nano-oxide soft agglomerates was studied and approved through the use of ion exchange resin loaded with cerium and gadolinium. The formation of the solid solution was followed through in-situ measurements such as XAS, XRD, Raman, TGA and DSC. Key temperatures were identified for the formation of the mixed-oxide. Following this study, the microstructure and particle size of oxide microspheres formed highlight the formation of soft nano-arrangments. - Highlights: • Soft microspherical agglomerates able to be decomposed into nano-sized materials. • In situ study of cerium/gadolinium-loaded ion exchange resin conversion in oxide. • In situ multi-scale study

  6. Ion Exchange Studies for Removal of Sulfate from Hanford Tank Waste Envelope C (241-AN-107) Using SuperLig 655 Resin

    SciTech Connect

    DE Kurath; JR Bontha; DL Blanchard; SK Fiskum; BM Rapko

    2000-08-23

    BNFL Inc. is evaluating various pretreatment technologies to mitigate the impacts of sulfate on the LAW vitrification system. One pretreatment technology for separating sulfate from LAW solutions involves the use of SuperLig{reg_sign} 655 (SL-655), a proprietary ion exchange material developed and supplied by IBC Advanced Technologies, Inc., American Fork, UT. This report describes testing of SL-655 with diluted ([Na] {approximately} 5 M) waste from Hanford Tank 241-AN-107 at Battelle, Pacific Northwest Division. Batch contact studies were conducted from 4 to 96 hours to determine the sulfate distribution coefficient and reaction kinetics. A small-scale ion exchange column test was conducted to evaluate sulfate removal, loading, breakthrough, and elution from the SL-655. In all of these tests, an archived 241-AN-107 tank waste sample (pretreated to remove Cs, Sr, and transuranics elements) was used. The experimental details and results are described in this report. Under the test conditions, SL-655 was found to have no significant ion exchange affinity for sulfate in this matrix. The batch contact study resulted in no measurable difference in the aqueous sulfate concentration following resin contact (K{sub d} {approximately} 0). The column test also demonstrated SL-655 had no practical affinity for sulfate in the tested matrix. Within experimental error, the sulfate concentration in the column effluent was equal to the concentration in the feed after passing 3 bed volumes of sample through the columns. Furthermore, some, if not all, of the decreased sulfate concentration in these first three column volumes of effluent can be ascribed to mixing and dilution of the 241-AN-107 feed with the interstitial liquid present in the column at the start of the loading cycle. Finally, ICP-AES measurements on the eluate solutions showed the presence of barium as soon as contact with the feed solution is completed. Barium is a metal not detected in the feed solution. Should the

  7. Effect of adhesive hydrophilicity and curing-time on the permeability of resins bonded to water vs. ethanol-saturated acid-etched dentin

    PubMed Central

    Cadenaro, Milena; Breschi, Lorenzo; Rueggeberg, Frederick A.; Agee, Kelli; Di Lenarda, Roberto; Carrilho, Marcela; Tay, Franklin R.; Pashley, David H.

    2009-01-01

    Objective This study examined the ability of five comonomer blends (R1-R5) of methacrylate-based experimental dental adhesives solvated with 10 mass% ethanol, at reducing the permeability of acid-etched dentin. The resins were light-cured for 20, 40 or 60 s. The acid-etched dentin was saturated with water or 100% ethanol. Method Human unerupted third molars were converted into crown segments by removing the occlusal enamel and roots. The resulting crown segments were attached to plastic plates connected to a fluid-filled system for quantifying fluid flow across smear layer-covered dentin, acid-etched dentin and resin-bonded dentin. The degree of conversion of the resins was measured using Fourier transform infrared spectroscopy. Result Application of the most hydrophobic comonomer blend (R1) to water-saturated dentin produced the smallest reductions in dentin permeability (31.9, 44.1 and 61.1% after light-curing for 20, 40 or 60 s respectively). Application of the same blend to ethanol-saturated dentin reduced permeability of 74.1, 78.4 and 81.2%, respectively (p<0.05). Although more hydrophilic resins produced larger reductions in permeability, the same trend of significantly greater reductions in ethanol-saturated dentin over that of water-saturated dentin remained. This result can be explained by the higher solubility of resins in ethanol vs. water. Significance The largest reductions in permeability produced by resins were equivalent but not superior, to those produced by smear layers. Resin sealing of dentin remains a technique-sensitive step in bonding etch-and-rinse adhesives to dentin. PMID:18571228

  8. Uranium removal from contaminated groundwater by synthetic resins.

    PubMed

    Phillips, D H; Gu, B; Watson, D B; Parmele, C S

    2008-01-01

    Synthetic resins are shown to be effective in removing uranium from contaminated groundwater. Batch and field column tests showed that strong-base anion-exchange resins were more effective in removing uranium from both near-neutral-pH (6.5)- and high-pH (8)-low-nitrate-containing groundwaters, than metal-chelating resins, which removed more uranium from acidic-pH (5)-high-nitrate-containing groundwater from the Oak Ridge Reservation (ORR) Y-12 S-3 Ponds area in Tennessee, USA. Dowex 1-X8 and Purolite A-520E anion-exchange resins removed more uranium from high-pH (8)-low-nitrate-containing synthetic groundwater in batch tests than metal-chelating resins. The Dowex 21K anion-exchange resin achieved a cumulative loading capacity of 49.8 mg g(-1) before breakthrough in a field column test using near-neutral-pH (6.5)-low-nitrate-containing groundwater. However, in an acidic-pH (5)-high-nitrate-containing groundwater, metal-chelating resins Diphonix and Chelex-100 removed more uranium than anion-exchange resins. In 15 m L of acidic-pH (5)-high-nitrate-containing groundwater spiked with 20 mg L(-1) uranium, the uranium concentrations ranged from 0.95 mg L(-1) at 1-h equilibrium to 0.08 mg L(-1) at 24-h equilibrium for Diphonix and 0.17 mg L(-1) at 1-h equilibrium to 0.03 mg L(-1) at 24-h equilibrium for Chelex-100. Chelex-100 removed more uranium in the first 10 min in the 100mL of acidic-(pH 5)-high-nitrate-containing groundwater ( approximately 5 mg L(-1) uranium); however, after 10 min, Diphonix equaled or out-performed Chelex-100. This study presents an improved understanding of the selectivity and sorption kenetics of a range of ion-exchange resins that remove uranium from both low- and high-nitrate-containing groundwaters with varying pHs. PMID:17697694

  9. Uranium Removal from Contaminated Groundwater by Synthetic Resins

    SciTech Connect

    Phillips, Debra H.; Gu, Baohua; Watson, David B; Parmele, C. S.

    2008-01-01

    Synthetic resins are shown to be effective in removing uranium from contaminated groundwater. Batch and field column tests showed that strong-base anion-exchange resins were more effective in removing uranium from both near-neutral-pH (6.5)- and high-pH (8)-low-nitrate-containing ground waters, than metal-chelating resins, which removed more uranium from acidic-pH (5)-high-nitrate-containing groundwater from the Oak Ridge Reservation (ORR) Y-12 S-3 Ponds area in Tennessee, USA. Dowex 1-X8 and Purolite A-520E anion-exchange resins removed more uranium from high-pH (8)-low-nitrate-containing synthetic groundwater in batch tests than metal-chelating resins. The Dowex{trademark} 21K anion-exchange resin achieved a cumulative loading capacity of 49.8 mg g{sup -1} before breakthrough in a field column test using near-neutral-pH (6.5)-low-nitrate-containing groundwater. However, in an acidic-pH (5)-high-nitrate-containing groundwater, metal-chelating resins Diphonix and Chelex-100 removed more uranium than anion-exchange resins. In 15 mL of acidic-pH (5)-high-nitrate-containing groundwater spiked with 20 mg L{sup -1} uranium, the uranium concentrations ranged from 0.95 mg L{sup -1} at 1-h equilibrium to 0.08 mg L{sup -1} at 24-h equilibrium for Diphonix and 0.17 mg L{sup -1} at 1-h equilibrium to 0.03 mg L{sup -1} at 24-h equilibrium for Chelex-100. Chelex-100 removed more uranium in the first 10 min in the 100 mL of acidic-(pH 5)-high-nitrate-containing groundwater (5 mg L{sup -1} uranium); however, after 10 min, Diphonix equaled or out-performed Chelex-100. This study presents an improved understanding of the selectivity and sorption kinetics of a range of ion-exchange resins that remove uranium from both low- and high-nitrate-containing groundwaters with varying pHs.

  10. Adsorption of Rh(III) complexes from chloride solutions obtained by leaching chlorinated spent automotive catalysts on ion-exchange resin Diaion WA21J.

    PubMed

    Shen, Shaobo; Pan, Tonglin; Liu, Xinqiang; Yuan, Lei; Wang, Jinchao; Zhang, Yongjian; Guo, Zhanchen

    2010-07-15

    It was found that Rh, Pd and Pt contained in the spent ceramic automotive catalysts could be effectively extracted by dry chlorination with chlorine. In order to concentrate Rh(III) ions contained in the chloride solutions obtained, thermodynamic and kinetics studies for adsorption of Rh(III) complexes from the chloride solutions on an anionic exchange resin Diaion WA21J were carried out. Rh, Pd, Pt, Al, Fe, Si, Zn and Pb from the chloride solution could be adsorbed on the resin. The distribution coefficients (K(d)) of Rh(III) decreased with the increase in initial Rh(III) concentration or in adsorption temperature. The isothermal adsorption of Rh(III) was found to fit Langmuir, Freundlich and Dubinin-Kaganer-Radushkevich models under the adsorption conditions. The maximum monolayer adsorption capacities Q(max) based on Langmuir adsorption isotherms were 6.39, 6.61 and 5.81 mg/g for temperatures 18, 28 and 40 degrees C, respectively. The apparent adsorption energy of Rh was about -7.6 kJ/mol and thus Rh(III) adsorption was a physical type. The experimental data obtained could be better simulated by pseudo-first-order kinetic model and the activation energy obtained was 6.54 J/mol. The adsorption rate of Rh(III) was controlled by intraparticle diffusion in most of time of adsorption process. PMID:20346581

  11. METHOD OF SEPARATING RARE EARTHS BY ION EXCHANGE

    DOEpatents

    Spedding, F.H.; Powell, J.E.

    1960-10-18

    A process is given for separating yttrium and rare earth values having atomic numbers of from 57 through 60 and 68 through 71 from an aqueous solution whose pH value can range from 1 to 9. All rare earths and yttrium are first adsorbed on a cation exchange resin, and they are then eluted with a solution of N-hydroxyethylethylenediaminetriacetic acid (HEDTA) in the order of decreasing atomic number, yttrium behaving like element 61; the effluents are collected in fractions. The HEDTA is recovered by elution with ammonia solution and the resin is regenerated with sulfuric acid. Rare earths are precipitated from the various effluents with oxalic acid, and each supernatant is passed over cation exchange resin for adsorption of HEDTA and nonprecipitated rare earths: the oxalic acid is not retained by the resin.

  12. 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.

  13. Effect of ascorbic acid, ethanol and acetone on adhesion between the treated fiber posts and composite resin cores

    PubMed Central

    Zahra, Khamverdi

    2012-01-01

    PURPOSE The aim of the present study was to assess the effect of ascorbic acid, ethanol and acetone on microtensile bond strength between fiber posts pre-treated with hydrogen peroxide and composite resin cores. MATERIALS AND METHODS Twenty four fiber posts were pre-treated with 24% hydrogen peroxide and divided into 4 groups as follows: G1: no treatment, as control group; G2: treatment with 10% ascorbic acid solution for 5 minutes; G3: treatment with 70% ethanol solution for 5 minutes; and G4: treatment with 70% acetone solution for 5 minutes. Each fiber post was surrounded by a cylinder-shaped polyglass matrix which was subsequently filled with composite resin. Two sections from each sample were selected for microtensile test at a crosshead with speed of 0.5 mm/min. Statistical analyses were performed using one-way ANOVA and a post hoc Tukey HSD test. Fractured surfaces were observed under a stereomicroscope at ×20 magnification. The fractured surfaces of the specimens were observed and evaluated under a SEM. RESULTS Means of microtensile bond strength values (MPa) and standard deviations in the groups were as follows: G1: 9.70±0.81; G2: 12.62±1.80; G3: 16.60±1.93; and G4: 21.24±1.95. G4 and G1 had the highest and the lowest bond strength values, respectively. A greater bond strength value was seen in G3 compared to G2. There were significant differences between all the groups (P<.001). All the failures were of the adhesive mode. CONCLUSION Application of antioxidant agents may increase microtensile bond strength between fiber posts treated with hydrogen peroxide and composite cores. Acetone increased bond strength more than ascorbic acid and ethanol. PMID:23236569

  14. A method to buffer the concentrations of free Zn and Cd ions using a cation exchange resin in bacterial toxicity studies

    SciTech Connect

    Knight, B.; McGrath, S.P.

    1995-12-01

    The chemical form or species of metal present in a growth system is crucial to the toxicity of that metal. A growth medium is described in which the free metal concentration of either Zn or Cd is known. A method using a cation exchange resin as a buffer to maintain free metal ion concentrations during microbial growth is discussed. Using a buffered system, free concentrations of 3.4 {micro}g Cd L{sup {minus}1} and 57 {micro}g Zn L{sup {minus}1} reduced the growth rate of a sensitive isolate of Rhizobium leguminosarum biovar trifolii. The results demonstrate that to assess the true toxicity of Cd and Zn, the free ion concentration must be considered and that small free concentrations must be buffered.

  15. Selective determination of ammonium ions by high-speed ion-exclusion chromatography on a weakly basic anion-exchange resin column.

    PubMed

    Mori, Masanobu; Tanaka, Kazuhiko; Helaleh, Murad I H; Xu, Qun; Ikedo, Mikaru; Ogura, Yutaka; Sato, Shinji; Hu, Wenzhi; Hasebe, Kiyoshi

    2003-05-16

    This paper describes an ion-exclusion chromatographic system for the rapid and selective determination of ammonium ion. The optimized ion-exclusion chromatographic system was established with a polymethacrylate-based weakly basic anion-exchange resin column (TSKgel DEAE-5PW) as the separation column, an aqueous solution containing 0.05 mM tetramethylammonium hydroxide (pH 9.10) as eluent with conductimetric detection for the analyte determination. Under the optimum chromatographic conditions, ammonium ion was determined within 2.3 min with a detection limit (S/N=3) better than 0.125 microM. Ammonium ion in rain and river waters was precisely determined using this ion-exclusion chromatographic system. PMID:12830892

  16. Synergic Catalysis of PdCu Alloy Nanoparticles within a Macroreticular Basic Resin for Hydrogen Production from Formic Acid.

    PubMed

    Mori, Kohsuke; Tanaka, Hiromasa; Dojo, Masahiro; Yoshizawa, Kazunari; Yamashita, Hiromi

    2015-08-17

    Highly dispersed PdCu alloy nanoparticles have been successfully prepared within a macroreticular basic resin bearing N(CH3 )2 functional groups. This previously unappreciated combination of alloy is first proven to be responsible for the efficient production of high-purity H2 from formic acid (HCOOH) dehydrogenation for chemical hydrogen storage. By the addition of Cu, the electronically promoted Pd sites show significantly higher catalytic activity as well as a better tolerance towards CO poisoning as compared to their monometallic Pd counterparts. Experimental and DFT calculation studies revealed not only the synergic alloying effect but also cooperative action by the N(CH3 )2 groups within the resin play crucial roles in achieving exceptional catalytic performances. In addition to the advantages such as, facile preparation method, free of additives, recyclable without leaching of active component, and suppression of unfavorable CO formation less than 3 ppm, the present catalytic system is cost-effective because of the superior catalytic activity compared with that of well-established precious PdAg or PdAu catalysts. The present catalytic system is particularly desirable for an ideal hydrogen vector in terms of potential industrial application for fuel cells. PMID:26178687

  17. Revised Thermal Analysis of LANL Ion Exchange Column

    SciTech Connect

    Laurinat, J

    2006-04-11

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

  18. An Engineering Evaluation of Spherical Resorcinol Formaldehyde Resin

    SciTech Connect

    Birdwell Jr, Joseph F; Lee, Denise L; Taylor, Paul Allen; Collins, Robert T; Hunt, Rodney Dale

    2010-09-01

    A small column ion exchange (SCIX) system has been proposed for removal of cesium from caustic, supernatant, and dissolved salt solutions stored or generated from high-level tank wastes at the US Department of Energy (DOE) Hanford Site and Savannah River Sites. In both instances, deployment of SCIX systems, either in-tank or near-tank, is a means of expediting waste pretreatment and dispositioning with minimal or no new infrastructure requirements. Conceptually, the treatment approach can utilize a range of ion exchange media. Previously, both crystalline silicotitanate (CST), an inorganic, nonelutable sorbent, and resorcinol-formaldehyde (RF), an organic, elutable resin, have been considered for cesium removal from tank waste. More recently, Pacific Northwest National Laboratory (PNNL) evaluated use of SuperLig{reg_sign} 644, an elutable ion exchange medium, for the subject application. Results of testing indicate hydraulic limitations of the SuperLig{reg_sign} resin, specifically a high pressure drop through packed ion exchange columns. This limitation is likely the result of swelling and shrinkage of the irregularly shaped (granular) resin during repeated conversions between sodium and hydrogen forms as the resin is first loaded then eluted. It is anticipated that a similar flow limitation would exist in columns packed with conventional, granular RF resin. However, use of spherical RF resin is a likely means of mitigating processing limitations due to excessive pressure drop. Although size changes occur as the spherical resin is cycled through loading and elution operations, the geometry of the resin is expected to effectively mitigate the close packing that leads to high pressure drops across ion exchange columns. Multiple evaluations have been performed to determine the feasibility of using spherical RF resin and to obtain data necessary for design of an SCIX process. The work performed consisted of examination of radiation effects on resin performance

  19. Upgrade to Ion Exchange Modeling for Removal of Technetium from Hanford Waste Using SuperLig® 639 Resin

    SciTech Connect

    Hamm, L.; Smith, F.; Aleman, S.; McCabe, D.

    2013-05-16

    This report documents the development and application of computer models to describe the sorption of pertechnetate [TcO₄⁻], and its surrogate perrhenate [ReO₄⁻], on SuperLig® 639 resin. Two models have been developed: 1) A thermodynamic isotherm model, based on experimental data, that predicts [TcO₄⁻] and [ReO₄⁻] sorption as a function of solution composition and temperature and 2) A column model that uses the isotherm calculated by the first model to simulate the performance of a full-scale sorption process. The isotherm model provides a synthesis of experimental data collected from many different sources to give a best estimate prediction of the behavior of the pertechnetate-SuperLig® 639 system and an estimate of the uncertainty in this prediction. The column model provides a prediction of the expected performance of the plant process by determining the volume of waste solution that can be processed based on process design parameters such as column size, flow rate and resin physical properties.

  20. Polar modified post-cross-linked resin and its adsorption toward salicylic acid from aqueous solution: Equilibrium, kinetics and breakthrough studies.

    PubMed

    Fu, Zhenyu; He, Chunlian; Huang, Jianhan; Liu, You-Nian

    2015-08-01

    A novel polar modified post-cross-linked resin PDMPA was synthesized, characterized and evaluated for adsorption of salicylic acid from aqueous solution. PDMPA was prepared by a suspension polymerization of methyl acrylate (MA) and divinylbenzene (DVB), a Friedel-Crafts reaction and an amination reaction. After characterization of the chemical and pore structure of PDMPA, the adsorption behaviors of salicylic acid on PDMPA were determined in comparison with the precursor resins. The equilibrium adsorption capacity of salicylic acid on PDMPA was much larger than the precursor resins and the equilibrium data were correlated by both of the Langmuir and Freundlich models. The pseudo-second-order rate equation fitted the kinetic data better than the pseudo-first-order rate equation, and the micropore diffusion model could characterize the kinetic data very well. The dynamic experimental results showed that the breakthrough point and saturated point of salicylic acid on PDMPA were 40.3 and 92.4BV (1BV=10mL) at a feed concentration of 995.8mg/L and a flow rate of 1.4mL/min, and the resin column could be regenerated by 16.0BV of a mixture desorption solvent containing 0.01mol/L of NaOH (w/v) and 50% of ethanol (v/v). PMID:25863446

  1. Proton exchange in acid-base complexes induced by reaction coordinates with heavy atom motions

    NASA Astrophysics Data System (ADS)

    Alavi, Saman; Taghikhani, Mahdi

    2012-06-01

    We extend previous work on nitric acid-ammonia and nitric acid-alkylamine complexes to illustrate that proton exchange reaction coordinates involve the rocking motion of the base moiety in many double hydrogen-bonded gas phase strong acid-strong base complexes. The complexes studied involve the biologically and atmospherically relevant glycine, formic, acetic, propionic, and sulfuric acids with ammonia/alkylamine bases. In these complexes, the magnitude of the imaginary frequencies associated with the proton exchange transition states are <400 cm-1. This contrasts with widely studied proton exchange reactions between symmetric carboxylic acid dimers or asymmetric DNA base pair and their analogs where the reaction coordinate is localized in proton motions and the magnitude of the imaginary frequencies for the transition states are >1100 cm-1. Calculations on complexes of these acids with water are performed for comparison. Variations of normal vibration modes along the reaction coordinate in the complexes are described.

  2. Asparagine promotes cancer cell proliferation through use as an amino acid exchange factor

    PubMed Central

    Krall, Abigail S.; Xu, Shili; Graeber, Thomas G.; Braas, Daniel; Christofk, Heather R.

    2016-01-01

    Cellular amino acid uptake is critical for mTOR complex 1 (mTORC1) activation and cell proliferation. However, the regulation of amino acid uptake is not well-understood. Here we describe a role for asparagine as an amino acid exchange factor: intracellular asparagine exchanges with extracellular amino acids. Through asparagine synthetase knockdown and altering of media asparagine concentrations, we show that intracellular asparagine levels regulate uptake of amino acids, especially serine, arginine and histidine. Through its exchange factor role, asparagine regulates mTORC1 activity and protein synthesis. In addition, we show that asparagine regulation of serine uptake influences serine metabolism and nucleotide synthesis, suggesting that asparagine is involved in coordinating protein and nucleotide synthesis. Finally, we show that maintenance of intracellular asparagine levels is critical for cancer cell growth. Collectively, our results indicate that asparagine is an important regulator of cancer cell amino acid homeostasis, anabolic metabolism and proliferation. PMID:27126896

  3. Computing in mammalian cells with nucleic acid strand exchange

    NASA Astrophysics Data System (ADS)

    Groves, Benjamin; Chen, Yuan-Jyue; Zurla, Chiara; Pochekailov, Sergii; Kirschman, Jonathan L.; Santangelo, Philip J.; Seelig, Georg

    2016-03-01

    DNA strand displacement has been widely used for the design of molecular circuits, motors, and sensors in cell-free settings. Recently, it has been shown that this technology can also operate in biological environments, but capabilities remain limited. Here, we look to adapt strand displacement and exchange reactions to mammalian cells and report DNA circuitry that can directly interact with a native mRNA. We began by optimizing the cellular performance of fluorescent reporters based on four-way strand exchange reactions and identified robust design principles by systematically varying the molecular structure, chemistry and delivery method. Next, we developed and tested AND and OR logic gates based on four-way strand exchange, demonstrating the feasibility of multi-input logic. Finally, we established that functional siRNA could be activated through strand exchange, and used native mRNA as programmable scaffolds for co-localizing gates and visualizing their operation with subcellular resolution.

  4. Computing in mammalian cells with nucleic acid strand exchange

    PubMed Central

    Pochekailov, Sergii; Kirschman, Jonathan L.; Santangelo, Philip J.; Seelig, Georg

    2015-01-01

    DNA strand displacement has been widely used for the design of molecular circuits, motors, and sensors in cell-free settings. Recently, it has been shown that this technology can also operate in biological environments, but capabilities remain limited. Here, we look to adapt strand displacement and exchange reactions to mammalian cells and report DNA circuitry that can directly interact with a native mRNA. We began by optimizing the cellular performance of fluorescent reporters based on four-way strand exchange reactions and identified robust design principles by systematically varying the molecular structure, chemistry and delivery method. Next, we developed and tested AND and OR logic gates based on four-way strand exchange, demonstrating the feasibility of multi-input logic. Finally, we established that functional siRNA could be activated through strand exchange, and used native mRNA as programmable scaffolds for co-localizing gates and visualizing their operation with subcellular resolution. PMID:26689378

  5. Computing in mammalian cells with nucleic acid strand exchange.

    PubMed

    Groves, Benjamin; Chen, Yuan-Jyue; Zurla, Chiara; Pochekailov, Sergii; Kirschman, Jonathan L; Santangelo, Philip J; Seelig, Georg

    2016-03-01

    DNA strand displacement has been widely used for the design of molecular circuits, motors, and sensors in cell-free settings. Recently, it has been shown that this technology can also operate in biological environments, but capabilities remain limited. Here, we look to adapt strand displacement and exchange reactions to mammalian cells and report DNA circuitry that can directly interact with a native mRNA. We began by optimizing the cellular performance of fluorescent reporters based on four-way strand exchange reactions and identified robust design principles by systematically varying the molecular structure, chemistry and delivery method. Next, we developed and tested AND and OR logic gates based on four-way strand exchange, demonstrating the feasibility of multi-input logic. Finally, we established that functional siRNA could be activated through strand exchange, and used native mRNA as programmable scaffolds for co-localizing gates and visualizing their operation with subcellular resolution. PMID:26689378

  6. Catalytic Upgrading of bio-oil using 1-octene and 1-butanol over sulfonic acid resin catalysts

    SciTech Connect

    Zhang, Zhijun; Wang, Qingwen; Tripathi, Prabhat; Pittman, Charles U.

    2011-02-04

    Raw bio-oil from fast pyrolysis of biomass must be refined before it can be used as a transporation fuel, a petroleum refinery feed or for many other fuel uses. Raw bio-oil was upgraded with the neat model olefin, 1-octene, and with 1-octene/1-butanol mixtures over sulfonic acid resin catalysts frin 80 to 150 degrees celisus in order to simultaneously lower water content and acidity and to increase hydrophobicity and heating value. Phase separation and coke formation were key factors limiting the reaction rate during upgrading with neat 1-octene although octanols were formed by 1-octene hydration along with small amounts of octyl acetates and ethers. GC-MS analysis confirmed that olefin hydration, carboxylic acid esterification, acetal formation from aldehydes and ketones and O- and C-alkylations of phenolic compounds occurred simultaneously during upgrading with 1-octene/1-butanol mixtures. Addition of 1-butanol increased olefin conversion dramatically be reducing mass transfer restraints and serving as a cosolvent or emulsifying agent. It also reacted with carboxylic acids and aldehydes/ketones to form esters, and acetals, respectively, while also serving to stabilize bio-oil during heating. 1-Butanol addition also protected the catalysts, increasing catalyst lifetime and reducing or eliminationg coking. Upgrading sharply increased ester content and decreased the amounts of levoglucosan, polyhydric alcohols and organic acids. Upgrading lowered acidity (pH value rise from 2.5 to >3.0), removed the uppleasant ordor and increased hydrocarbon solubility. Water content decreased from 37.2% to < 7.5% dramatically and calorific value increased from 12.6 MJ kg to about 30.0 MJ kg.

  7. Selective exchange of divalent transition metal ions in cryptomelane-type manganic acid with tunnel structure

    SciTech Connect

    Tsuji, M. ); Komarneni, S. )

    1993-03-01

    The ion-exchange selectivity of divalent transition metal ions on cryptomelane-type manganic acid (CMA) with tunnel structure has been studied using the distribution coefficients ([ital K][sub [ital d

  8. On-line cation exchange for suppression of adduct formation in negative-ion electrospray mass spectrometry of nucleic acids.

    PubMed

    Huber, C G; Buchmeiser, M R

    1998-12-15

    One major difficulty in the analysis of nucleic acids by electrospray mass spectrometry is represented by the affinity of the polyanionic sugar-phosphate backbone for nonvolatile cations, especially ubiquitous sodium and potassium ions. A simple on-line sample preparation system comprising a microflow pumping system and 45 x 0.8-mm-i.d. microcolumns packed with weak or strong cation-exchange resins is described for the efficient removal of cations from nucleic acid samples. Samples were analyzed by flow injection analysis at a 3-5 microL/min flow of 10 mM triethylamine in 50% water-50% acetonitrile. After on-line desalting, mass spectra of oligonucleotides revealed no significant sodium adduct peaks. Moreover, signal-to-noise ratios were greatly enhanced compared to direct injection of the samples. Electrospray mass spectrometry with on-line sample preparation allowed accurate molecular mass determinations of picomole amounts of crude oligonucleotide preparations ranging in size from 8 to 80 nucleotides within a few minutes. The good linearity of the calibration plot (R2 = 0.9988) over at least 2 orders of magnitude and a relative standard deviation in peak areas of less than 9% permitted the sensitive quantitative measurement of oligonucleotides in a concentration range of 0.2-20 microM with selected-ion monitoring. Finally, the on-line sample preparation system was evaluated for the mass spectrometric analysis of complex oligonucleotide mixtures. PMID:9868919

  9. CATION EXCHANGE METHOD FOR THE RECOVERY OF PROTACTINIUM

    DOEpatents

    Studier, M.H.; Sullivan, J.C.

    1959-07-14

    A cation exchange prccess is described for separating protactinium values from thorium values whereby they are initially adsorbed together from an aqueous 0.1 to 2 N hydrochloric acid on a cation exchange resin in a column. Then selectively eluting the thorium by an ammonium sulfate solution and subsequently eluting the protactinium by an oxalate solution.

  10. Separation and conductimetric detection of C1-C7 aliphatic monocarboxylic acids and C1-C7 aliphatic monoamines on unfunctionized polymethacrylate resin columns.

    PubMed

    Ohta, Kazutoku; Towata, Atsuya; Ohashi, Masayoshi; Takeuchi, Toyohide

    2004-06-11

    The application of unfunctionized polymethacrylate resin (TSKgel G3000PWXL) as a stationary phase in liquid chromatography with conductimetric detection for C1-C7 aliphatic monocarboxylic acids (formic acid, acetic acid, propionic acid, butyric acid, isovaleric acid, valeric acid, 3,3-dimethylbutyric acid, 4-methylvaleric acid, hexanoic acid, 2-methylhexanoic acid, 5-methylhexanoic acid and heptanoic acid) and C1-C7 aliphatic monoamines (methylamine, ethylamine, propylamine, isobutylamine, butylamine, isoamylamine, amylamine, 1,3-dimethylbutylamine, hexylamine, 2-heptylamine and heptylamine) was attempted with C8 aliphatic monocarboxylic acids (2-propylvaleric acid, 2-ethylhexanoic acid, 2-methylheptanoic acid and octanoic acid) and C8 aliphatic monoamines (1,5-dimethylhexylamine, 2-ethylhexylamine, 1-methylheptylamine and octylamine) as eluents, respectively. Using 1 mM 2-methylheptanoic acid at pH 4.0 as the eluent, excellent separation and relatively high sensitive detection for these C1-C7 carboxylic acids were achieved on a TSKgel G3000PWXL column (150 mm x 6 mm i.d.) in 60 min. Using 2 mM octylamine at pH 11.0 as the eluent, excellent separation and relatively high sensitive detection for these C1-C7 amines were also achieved on the TSKgel G3000PWXL column in 60 min. PMID:15250420

  11. Preparation of biodiesel from rice bran fatty acids catalyzed by heterogeneous cesium-exchanged 12-tungstophosphoric acids.

    PubMed

    Srilatha, K; Sree, Rekha; Prabhavathi Devi, B L A; Sai Prasad, P S; Prasad, R B N; Lingaiah, N

    2012-07-01

    Biodiesel synthesis from rice bran fatty acids (RBFA) was carried out using cesium exchanged 12-tungstophosphoric acid (TPA) catalysts. The physico-chemical properties of the catalysts were derived from X-ray diffraction (XRD), Fourier transform infrared (FTIR), temperature programmed desorption (TPD) of NH(3) and scanning electron microscopy (SEM). The characterization techniques revealed that the Keggin structure of TPA remained intact as Cs replaced protons. The partial exchange of Cs for protons resulted in an increase in acidity and the catalysts with one Cs(+) (Cs(1)H(2)PW(12)O(40)) showed highest acidity. Under optimized conditions about 92% conversion of RBFA was obtained. The catalyst was reused for five times and retained of its original activity. Pseudo-first order model was applied to correlate the experimental kinetic data. Modified tungstophosphoric acids are efficient solid acid catalysts for the synthesis of biodiesel from the oils containing high FFA. PMID:22609655

  12. Functional role of polar amino acid residues in Na+/H+ exchangers.

    PubMed Central

    Wiebe, C A; Dibattista, E R; Fliegel, L

    2001-01-01

    Na(+)/H(+) exchangers are a family of ubiquitous membrane proteins. In higher eukaryotes they regulate cytosolic pH by removing an intracellular H(+) in exchange for an extracellular Na(+). In yeast and Escherichia coli, Na(+)/H(+) exchangers function in the opposite direction to remove intracellular Na(+) in exchange for extracellular H(+). Na(+)/H(+) exchangers display an internal pH-sensitivity that varies with the different antiporter types. Only recently have investigations examined the amino acids involved in pH-sensitivity and in cation binding and transport. Histidine residues are good candidates for H(+)-sensing amino acids, since they can ionize within the physiological pH range. Histidine residues have been shown to be important in the function of the E. coli Na(+)/H(+) exchanger NhaA and in the yeast Na(+)/H(+) exchanger sod2. In E. coli, His(225) of NhaA may function to interact with, or regulate, the pH-sensory region of NhaA. In sod2, His(367) is also critical to transport and may be a functional analogue of His(225) of NhaA. Histidine residues are not critical for the function of the mammalian Na(+)/H(+) exchanger, although an unusual histidine-rich sequence of the C-terminal tail has some influence on activity. Other amino acids involved in cation binding and transport by Na(+)/H(+) exchangers are only beginning to be studied. Amino acids with polar side chains such as aspartate and glutamate have been implicated in transport activity of NhaA and sod2, but have not been studied in the mammalian Na(+)/H(+) exchanger. Further studies are needed to elucidate the mechanisms involved in pH-sensitivity and cation binding and transport by Na(+)/H(+) exchangers. PMID:11415429

  13. Improvement of enamel bond strengths for conventional and resin-modified glass ionomers: acid-etching vs. conditioning*

    PubMed Central

    Zhang, Ling; Tang, Tian; Zhang, Zhen-liang; Liang, Bing; Wang, Xiao-miao; Fu, Bai-ping

    2013-01-01

    Objective: This study deals with the effect of phosphoric acid etching and conditioning on enamel micro-tensile bond strengths (μTBSs) of conventional and resin-modified glass ionomer cements (GICs/RMGICs). Methods: Forty-eight bovine incisors were prepared into rectangular blocks. Highly-polished labial enamel surfaces were either acid-etched, conditioned with liquids of cements, or not further treated (control). Subsequently, two matching pre-treated enamel surfaces were cemented together with one of four cements [two GICs: Fuji I (GC), Ketac Cem Easymix (3M ESPE); two RMGICs: Fuji Plus (GC), RelyX Luting (3M ESPE)] in preparation for μTBS tests. Pre-treated enamel surfaces and cement-enamel interfaces were analyzed by scanning electron microscopy (SEM). Results: Phosphoric acid etching significantly increased the enamel μTBS of GICs/RMGICs. Conditioning with the liquids of the cements produced significantly weaker or equivalent enamel μTBS compared to the control. Regardless of etching, RMGICs yielded stronger enamel μTBS than GICs. A visible hybrid layer was found at certain enamel-cement interfaces of the etched enamels. Conclusions: Phosphoric acid etching significantly increased the enamel μTBSs of GICs/RMGICs. Phosphoric acid etching should be recommended to etch the enamel margins before the cementation of the prostheses such as inlays and onlays, using GICs/RMGICs to improve the bond strengths. RMGICs provided stronger enamel bond strength than GICs and conditioning did not increase enamel bond strength. PMID:24190447

  14. Investigation of the gas-phase hydrogen/deuterium exchange behavior of aromatic dicarboxylic acids in a quadrupole ion trap

    NASA Astrophysics Data System (ADS)

    Chipuk, Joseph E.; Brodbelt, Jennifer S.

    2007-11-01

    Gas-phase hydrogen/deuterium (H/D) exchange reactions of four deprotonated aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid and 2,6-naphthalic acid) with D2O were performed in a quadrupole ion trap mass spectrometer. Experimental results showed significant differences in the rate and extent of exchange when the relative position of the carboxylic acid groups varied. Spontaneous and near complete exchange of one aromatic hydrogen atom occurred when the carboxylic acid groups were in the meta-position, whereas no additional exchange was observed for either the ortho- or para-isomers or for the structurally similar naphthalic acid. Computational investigations support the participation of several possible exchange mechanisms with the contribution of each relying heavily on the relative orientation of the acid moieties. A relay mechanism that bridges the deprotonation site and the labile hydrogen site appears to be responsible for the H/D exchange of not only the labile hydrogen atom of isophthalic acid, but also for the formation of a stable carbanion and corresponding subsequent exchange of one aromatic hydrogen atom. The impact of hydrogen bonding on the relay mechanism is demonstrated by the reaction of phthalic acid as the extent and rate of reaction are greatly retarded by the favorable interaction of the two carboxylic acid groups. Finally, a flip-flop mechanism is likely responsible for the exchange of both terephthalic acid and 2,6-naphthalic acid where the reactive sites are too remote for exchange via relay.

  15. Deuterium exchange during acid-demineralisation. [of Murchison meteorite

    NASA Technical Reports Server (NTRS)

    Kerridge, John F.; Chang, Sherwood; Shipp, Ruth

    1988-01-01

    Isotopic analyses of residues prepared by demineralization of the Murchison meteorite using D-labelled reagents provide evidence for measurable exchange of H-isotopes between residue and reagents. Precise quantification of this effect is precluded by substantial inhomogeneity of the meteoritic organic matter. A conservative estimate of the degree of exchange is 3-5 percent of the H pyrolyzable as H2O. This could affect the shape of the curve defining D release as a function of temperature, but does not change conclusions previously drawn concerning the nature of the bulk D enrichment of insoluble organic matter in meteorites.

  16. ANALYSIS OF VENTING OF A RESIN SLURRY

    SciTech Connect

    Laurinat, J.; Hensel, S.

    2012-03-27

    A resin slurry venting analysis was conducted to address safety issues associated with overpressurization of ion exchange columns used in the Purex process at the Savannah River Site (SRS). If flow to these columns were inadvertently interrupted, an exothermic runaway reaction could occur between the ion exchange resin and the nitric acid used in the feed stream. The nitric acid-resin reaction generates significant quantities of noncondensable gases, which would pressurize the column. To prevent the column from rupturing during such events, rupture disks are installed on the column vent lines. The venting analysis models accelerating rate calorimeter (ARC) tests and data from tests that were performed in a vented test vessel with a rupture disk. The tests showed that the pressure inside the test vessel continued to increase after the rupture disk opened, though at a slower rate than prior to the rupture. Calculated maximum discharge rates for the resin venting tests exceeded the measured rates of gas generation, so the vent size was sufficient to relieve the pressure in the test vessel if the vent flow rate was constant. The increase in the vessel pressure is modeled as a transient phenomenon associated with expansion of the resin slurry/gas mixture upon rupture of the disk. It is postulated that the maximum pressure at the end of this expansion is limited by energy minimization to approximately 1.5 times the rupture disk burst pressure. The magnitude of this pressure increase is consistent with the measured pressure transients. The results of this analysis demonstrate the need to allow for a margin between the design pressure and the rupture disk burst pressure in similar applications.

  17. Polybenzimidazole film containing phosphoric acid as proton exchange membrane (PEM)

    NASA Astrophysics Data System (ADS)

    Ameri, Roya

    Polybenzimidazole is a linear polymer with a very high glass transition temperature. It has exceptional properties at elevated temperature such as stability, retention of stiffness, and toughness. PBI containing phosphoric acid has high proton conductivity and low water vapor permeability. A new way of direct film casting of PBI containing phosphoric acid, has been found. The use of trifluoroacetic acid as a solvent resulted in a new and quick way to prepare PBI film containing phosphoric acid which showed about four times more conductivity at a given doping level than PBI doped with phosphoric acid from DMAc solution. Mechanical property studies of different molecular weight PBI films etasb{inh} = 0.91 to 142 dl/g) have shown that increasing molecular weight linearly improved mechanical properties of PBI films with pronounced effect on toughness. As PBI film was doped with sulfuric acid, mechanical properties decreased with very sharp drop in toughness. More reduction in mechanical properties was observed as the concentration of sulfuric acid in the film increased. Doping PBI film with low concentrations of phosphoric acid improved modulus and strength at break while lowering the toughness. Increasing the concentration of acid in these films lowered the strength and modulus of PBI film. However, toughness first increased up to concentration of 200-300M% phosphoric acid and then decreased. Comparison of phosphoric acid doped PBI film and PBI film cast from PBI/TFA/Hsb3POsb4 solution reveals that phosphoric acid doped PBI film has at least three times better mechanical properties: toughness, modulus, and strength. X-ray photographs of PBI film cast from PBI/TFA/Hsb3POsb4 solution shows a crystalline pattern with a monoclinic unit cell of dimensions: a = 15.8 A, b = 13.23 A, c = 16.83 A, and gamma = 79.1sp0. On the other hand, phosphoric acid doped PBI film has relatively low crystallinity. PBI can cocrystallize with some complexing agent like trifluoroacetic acid

  18. Flow injection online spectrophotometric determination of uranium after preconcentration on XAD-4 resin impregnated with nalidixic acid.

    PubMed

    Shahida, Shabnam; Ali, Akbar; Khan, Muhammad Haleem; Saeed, Muhammad Mufazzal

    2013-02-01

    In this work, spectrophotometer was used as a detector for the determination of uranium from water, biological, and ore samples with a flow injection system coupled with solid phase extraction. In order to promote the online preconcentration of uranium, a minicolumn packed with XAD-4 resin impregnated with nalidixic acid was utilized. The system operation was based on U(VI) ion retention at pH 6 in the minicolumn at flow rate of 15.2 mL min(-1). The uranium complex was removed from the resin by 0.1 mol dm(-3) HCl at flow rate of 3.2 mL min(-1) and was mixed with arsenazo III solution (0.05 % solution in 0.1 mol dm(-3) HCl, 3.2 mL min(-1)) and driven to flow through cell of spectrophotometer where its absorbance was measured at 651 nm. The influence of chemical (pH and HCl (as eluent and reagent medium) concentration) and flow (sample and eluent flow rate and preconcentration time) parameters that could affect the performance of the system as well as the possible interferents was investigated. At the optimum conditions for 60 s preconcentration time (15.2 mL of sample volume), the method presented a detection limit of 1.1 μg L(-1), a relative standard deviation (RSD) of 0.8 % at 100 μg L(-1), enrichment factor of 30, and a sample throughput of 42 h(-1), whereas for 300 s of the preconcentration time (76 mL of sample volume), a detection limit of 0.22 μg L(-1), a RSD of 1.32 % at 10 μg L(-1), enrichment factor of 150, and a sampling frequency of 11 h(-1) were reported. PMID:22580790

  19. The use of modified divinylbenzene-polystyrene resins in the separation of fermentation products. A case study utilizing amino acids and a dipeptide.

    PubMed

    Casillas, J L; Addo-Yobo, F; Kenney, C N; Aracil, J; Martínez, M

    1992-01-01

    The adsorption of phenylalanine, aspartic acid, asparagine and aspartame from phosphate-buffered aqueous solutions with modified divinyl-benzene-polystyrene resins has been investigated using high pressure liquid chromatography (HPLC). The pH studied was 2.8, the temperature range was 293-313 K and the ionic strength was maintained at 1.0 mol dm-3. Over the range of variables investigated, the adsorption isotherms are linear and may be characterized by temperature and pH-dependent apparent adsorption equilibrium constants, characteristic of the resin-adsorbate system. By studying the dependence on temperature of this adsorption constant, heats of adsorption and entropy of adsorption have been estimated. In terms of the heat liberated on adsorption, the amino acids and a dipeptide can be ranked thus: aspartame > phenylalanine > aspartic acid > asparagine. PMID:1368901

  20. Sequential injection analysis of lead using time-based colorimetric detection and preconcentration on an anionic-exchange resin.

    PubMed

    Aracama, Nestor Zárate; Araújo, Alberto N; Perez-Olmos, Ricardo

    2004-04-01

    The development of a sequential injection analysis manifold for the colorimetric determination of lead in water samples is described The concentration of lead was assessed from its catalytic effect on the reaction of resazurine reduction caused by sulfide in an alkali medium. To that effect, the reaction zone was stopped at the detector, and the time interval required for the attainment of an absorbance decrease of 0.800 at the wavelength of 610 nm was estimated. Interference of other transition metals of the samples was minimized by adding potassium iodide to the sample and retaining the iodocomplexes formed in an on-line anionic resin (AGI X8). Elution was made with a 2 mol/L sodium hydroxide solution. The relationship [SIA] microg/L = 0.99 (+/- 0.11) x [ETAAS] microg/L + 0 (+/- 4) was obtained upon comparing the results given by the proposed system and by electrothermal atomization atomic absorption spectrometry (ETAAS) after the analysis of ten water samples. PMID:15116968

  1. Composition of exchangeable bases and acidity in soils of the Crimean Mountains

    NASA Astrophysics Data System (ADS)

    Kostenko, I. V.

    2015-08-01

    Acid forest and mountainous meadow soils of the Crimean Mountains were studied. The amount of hydrogen and aluminum ions extracted from these soils depended on the pH of extracting agents. The maximum values of the soil acidity were obtained upon the extraction with a strongly alkaline solution of sodium acetate in 0.05 N NaOH. The application of this extractant made it possible to determine the total exchange acidity, the total amount of extractable aluminum, and the total cation exchange capacity of the soils after the extraction of all the acidic components from them. The values of these characteristics were significantly higher than the values of the potential acidity and cation exchange capacity obtained by the routine analytical methods. Hydrogen predominated among the acidic components of the exchange acidity in the humus horizons, whereas aluminum predominated among them in the underlying mineral horizons. Hydrothermic conditions and the character of vegetation and parent materials were the major factors affecting the relationships between bases and acidic components in the soil adsorption complex.

  2. Carboxylic-Acid-passivated metal oxide nanocrystals: ligand exchange characteristics of a new binding motif.

    PubMed

    De Roo, Jonathan; Justo, Yolanda; De Keukeleere, Katrien; Van den Broeck, Freya; Martins, José C; Van Driessche, Isabel; Hens, Zeger

    2015-05-26

    Ligand exchange is central in the processing of inorganic nanocrystals (NCs) and requires understanding of surface chemistry. Studying sterically stabilized HfO2 and ZrO2 NCs using (1) H solution NMR and IR spectroscopy as well as elemental analysis, this paper demonstrates the reversible exchange of initial oleic acid ligands for octylamine and self-adsorption of oleic acid at NC surfaces. Both processes are incompatible with an X-type binding motif of carboxylic acids as reported for sulfide and selenide NCs. We argue that this behavior stems from the dissociative adsorption of carboxylic acids at the oxide surface. Both proton and carboxylate moieties must be regarded as X-type ligands yielding a combined X2 binding motif that allows for self-adsorption and exchange for L-type ligands. PMID:25866095

  3. ESTIMATION OF RADIOLYTIC GAS GENERATION RATE FOR CYLINDRICAL RADIOACTIVE WASTE PACKAGES - APPLICATION TO SPENT ION EXCHANGE RESIN CONTAINERS

    SciTech Connect

    Husain, A.; Lewis, Brent J.

    2003-02-27

    Radioactive waste packages containing water and/or organic substances have the potential to radiolytically generate hydrogen and other combustible gases. Typically, the radiolytic gas generation rate is estimated from the energy deposition rate and the radiolytic gas yield. Estimation of the energy deposition rate must take into account the contributions from all radionuclides. While the contributions from non-gamma emitting radionuclides are relatively easy to estimate, an average geometry factor must be computed to determine the contribution from gamma emitters. Hitherto, no satisfactory method existed for estimating the geometry factors for a cylindrical package. In the present study, a formulation was developed taking into account the effect of photon buildup. A prototype code, called PC-CAGE, was developed to numerically solve the integrals involved. Based on the selected dimensions for a cylinder, the specified waste material, the photon energy of interest and a value for either the absorption or attenuation coefficient, the code outputs values for point and average geometry factors. These can then be used to estimate the internal dose rate to the material in the cylinder and hence to calculate the radiolytic gas generation rate. Besides the ability to estimate the rates of radiolytic gas generation, PC-CAGE can also estimate the dose received by the container material. This is based on values for the point geometry factors at the surface of the cylinder. PC-CAGE was used to calculate geometry factors for a number of cylindrical geometries. Estimates for the absorbed dose rate in container material were also obtained. The results for Ontario Power Generation's 3 m3 resin containers indicate that about 80% of the source gamma energy is deposited internally. In general, the fraction of gamma energy deposited internally depends on the dimensions of the cylinder, the material within it and the photon energy; the fraction deposited increases with increasing

  4. Determination of resin acids during production of wood pellets--a comparison of HPLC/ESI-MS with the GC/FID MDHS 83/2 method.

    PubMed

    Axelsson, Sara; Eriksson, Kåre; Nilsson, Ulrika

    2011-10-01

    Resin acids are constituents of natural and technical products of widespread use. Exposure is known to cause health effects in the airways and on the skin. Liquid chromatography/positive ion electrospray-mass spectrometry (HPLC/pos ESI-MS) was investigated for determination of 7-oxodehydroabietic (7-OXO), dehydroabietic (DHAA) and abietic acid (AA) in wood dust-containing air samples as a derivatisation-free alternative to the GC/FID HSE method 83/2, developed by the Health and Safety Executive UK. The resin acid 7-OXO was measured as a marker for oxidised resin acids, which are known to be the main contact allergens in colophonium. The found detection limits were 0.42 ng m(-3) for 7-OXO, 5.2 ng m(-3) for DHAA and 9.4 ng m(-3) for AA, respectively, which are considerably lower than with the GC/FID method (24, 115 and 89 ng m(-3)). The two methods correlated well, although consistently and significantly lower concentrations of 7-OXO were detected with LC/MS. The higher concentration of this compound with MDHS 83/2 is suggested to be an artefact from the derivatisation step in the presence of soluble wood dust remains. PMID:21874165

  5. Voltage-dependent processes in the electroneutral amino acid exchanger ASCT2

    PubMed Central

    Zander, Catherine B.; Albers, Thomas

    2013-01-01

    Neutral amino acid exchange by the alanine serine cysteine transporter (ASCT)2 was reported to be electroneutral and coupled to the cotransport of one Na+ ion. The cotransported sodium ion carries positive charge. Therefore, it is possible that amino acid exchange is voltage dependent. However, little information is available on the electrical properties of the ASCT2 amino acid transport process. Here, we have used a combination of experimental and computational approaches to determine the details of the amino acid exchange mechanism of ASCT2. The [Na+] dependence of ASCT2-associated currents indicates that the Na+/amino acid stoichiometry is at least 2:1, with at least one sodium ion binding to the amino acid–free apo form of the transporter. When the substrate and two Na+ ions are bound, the valence of the transport domain is +0.81. Consistently, voltage steps applied to ASCT2 in the fully loaded configuration elicit transient currents that decay on a millisecond time scale. Alanine concentration jumps at the extracellular side of the membrane are followed by inwardly directed transient currents, indicative of translocation of net positive charge during exchange. Molecular dynamics simulations are consistent with these results and point to a sequential binding process in which one or two modulatory Na+ ions bind with high affinity to the empty transporter, followed by binding of the amino acid substrate and the subsequent binding of a final Na+ ion. Overall, our results are consistent with voltage-dependent amino acid exchange occurring on a millisecond time scale, the kinetics of which we predict with simulations. Despite some differences, transport mechanism and interaction with Na+ appear to be highly conserved between ASCT2 and the other members of the solute carrier 1 family, which transport acidic amino acids. PMID:23669717

  6. Ion-exclusion chromatographic behavior of aliphatic carboxylic acids and benzenecarboxylic acids on a sulfonated styrene--divinylbenzene co-polymer resin column with sulfuric acid containing various alcohols as eluent.

    PubMed

    Ohta, Kazutoku; Towata, Atsuya; Ohashi, Masayoshi

    2003-05-16

    The addition of C1-C7 alcohols (methanol, ethanol, propanol, butanol, heptanol, hexanol and heptanol) to dilute sulfuric acid as eluent in ion-exclusion chromatography using a highly sulfonated styrene-divinylbenzene co-polymer resin (TSKgel SCX) in the H+ form as the stationary phase was carried out for the simultaneous separations of both (a) C1-C7 aliphatic carboxylic acids (formic, acetic, propionic, isobutyric, butyric, isovaleric, valeric, 2-methylvaleric, isocaproic, caproic, 2,2-dimethyl-n-valeric, 2-methylhexanoic, 5-methylhexanoic and heptanoic acids) and (b) benzenecarboxylic acids (pyromellitic, hemimellitic, trimellitic, o-phthalic, m-phthalic, p-phthalic, benzoic and salicylic acids and phenol). Heptanol was the most effective modifier in ion-exclusion chromatography for the improvement of peak shapes and a reduction in retention volumes for higher aliphatic carboxylic acids and benzenecarboxylic acids. Excellent simultaneous separation and relatively highly sensitive conductimetric detection for these C1-C7 aliphatic carboxylic acids were achieved on the TSKgel SCX column (150 x 6 mm I.D.) in 30 min using 0.5 mM sulfuric acid containing 0.025% heptanol as eluent. Excellent simultaneous separation and highly sensitive UV detection at 200 nm for these benzenecarboxylic acids were also achieved on the TSKgel SCX column in 30 min using 5 mM sulfuric acid containing 0.075% heptanol as eluent. PMID:12830881

  7. Comparison of adsorption equilibrium models for the study of CL-, NO3- and SO4(2-) removal from aqueous solutions by an anion exchange resin.

    PubMed

    Dron, Julien; Dodi, Alain

    2011-06-15

    The removal of chloride, nitrate and sulfate ions from aqueous solutions by a macroporous resin is studied through the ion exchange systems OH(-)/Cl(-), OH(-)/NO(3)(-), OH(-)/SO(4)(2-), and HCO(3)(-)/Cl(-), Cl(-)/NO(3)(-), Cl(-)/SO(4)(2-). They are investigated by means of Langmuir, Freundlich, Dubinin-Radushkevitch (D-R) and Dubinin-Astakhov (D-A) single-component adsorption isotherms. The sorption parameters and the fitting of the models are determined by nonlinear regression and discussed. The Langmuir model provides a fair estimation of the sorption capacity whatever the system under study, on the contrary to Freundlich and D-R models. The adsorption energies deduced from Dubinin and Langmuir isotherms are in good agreement, and the surface parameter of the D-A isotherm appears consistent. All models agree on the order of affinity OH(-)exchange processes under study among other adsorption isotherms. The nonlinear regression results are also compared with linear regressions. While the parameter values are not affected, the evaluation of the best fitting model is biased by linearization. PMID:21497015

  8. LA-ICP-MS of rare earth elements concentrated in cation-exchange resin particles for origin attribution of uranium ore concentrate.

    PubMed

    Asai, Shiho; Limbeck, Andreas

    2015-04-01

    Rare earth elements (REE) concentrated on cation-exchange resin particles were measured with laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to obtain chondrite-normalized REE plots. The sensitivity of REE increased in ascending order of the atomic number, according to the sensitivity trend in pneumatic nebulization ICP-MS (PN-ICP-MS). The signal intensities of REE were nearly proportional to the concentrations of REE in the immersion solution used for particle-preparation. Minimum measurable concentration calculated from the net signals of REE was approximately 1 ng/g corresponding to 0.1 ng in the particle-preparation solution. In LA analysis, formation of oxide and hydroxide of the light REE and Ba which causes spectral interferences in the heavy REE measurement was effectively attenuated due to the solvent-free measurement capability, compared to conventional PN-ICP-MS. To evaluate the applicability of the proposed method, the REE-adsorbed particles prepared by immersing them in a U-bearing solution (commercially available U standard solution) were measured with LA-ICP-MS. Aside from the LA analysis, each concentration of REE in the same U standard solution was determined with conventional PN-ICP-MS after separating REE by cation-exchange chromatography. The concentrations of REE were ranging from 0.04 (Pr) to 1.08 (Dy) μg/g-U. The chondrite-normalized plot obtained through LA-ICP-MS analysis of the U standard sample exhibited close agreement with that obtained through the PN-ICP-MS of the REE-separated solution within the uncertainties. PMID:25640124

  9. Nanostructured gadolinium-doped ceria microsphere synthesis from ion exchange resin: Multi-scale in-situ studies of solid solution formation

    NASA Astrophysics Data System (ADS)

    Caisso, Marie; Lebreton, Florent; Horlait, Denis; Picart, Sébastien; Martin, Philippe M.; Bès, René; Renard, Catherine; Roussel, Pascal; Neuville, Daniel R.; Dardenne, Kathy; Rothe, Jörg; Delahaye, Thibaud; Ayral, André

    2014-10-01

    In the current nano-sized material revolution, the main limitations to a large-scale deployment of nanomaterials involve health concerns related to nano-dissemination via air. Developing new chemical routes benefiting from nano-size advantages while avoiding their hazards could overcome these limitations. Addressing this need, a chemical route leading to soft nano-particle agglomerates, i.e., macroscopic precursors presenting the ability to be decomposed into nano-sized materials, was developed and applied to Ce0.8Gd0.2O2-δ. Using cerium/gadolinium-loaded ion exchange resin, the Ce0.8Gd0.2O2-δ solid solution formation as a function of temperature was studied in-situ through X-ray diffraction, X-ray absorption spectroscopy and Raman spectroscopy. Temperatures corresponding to the organic skeleton decomposition and to the mixed oxide crystallization were identified. An optimal heat treatment, leading to nanostructured soft agglomerates, was established. Microsphere processing capabilities were evaluated and particle size distribution measurements were recorded. A very low fracture strength was calculated, and a nanometric particle size distribution (170 nm) was determined.

  10. B and N isolate-doped graphitic carbon nanosheets from nitrogen-containing ion-exchanged resins for enhanced oxygen reduction

    NASA Astrophysics Data System (ADS)

    Wang, Lei; Yu, Peng; Zhao, Lu; Tian, Chungui; Zhao, Dongdong; Zhou, Wei; Yin, Jie; Wang, Ruihong; Fu, Honggang

    2014-06-01

    B,N-codoped carbon nanostructures (BNCS) can serve as alternative low-cost metal-free electrocatalysts for oxygen reduction reactions (ORR). However, the compensation effect between the p- (B atoms) and n-type (N atoms) dopants would make the covalent boron-nitride (BN) easily formed during the synthesis of BNCS, leading to a unsatisfactory ORR activity. Therefore, it has been challenging to develop facile and rapid synthetic strategies for highly active BNCS without forming the direct covalent BN. Here, a facile method is developed to prepare B and N isolate-doped graphitic nanosheets (BNGS) by using iron species for saving N element and simultaneous doping the B element from nitrogen-containing ion-exchanged resins (NR). The resulting BNGS exhibits much more onset potential (Eonset) compared with the B-doped graphitic carbon nanosheets (BGS), N-doped graphitic carbon nanosheets (NGS), as well as B,N-codoped disorder carbon (BNC). Moreover, the BNGS shows well methanol tolerance propery and excellent stability (a minimal loss of activity after 5,000 potential cycles) compared to that of commercial Pt/C catalyst. The goog performance for BNGS towards ORR is attributed to the synergistic effect between B and N, and the well electrons transport property of graphitic carbon in BNGS.

  11. B and N isolate-doped graphitic carbon nanosheets from nitrogen-containing ion-exchanged resins for enhanced oxygen reduction

    PubMed Central

    Wang, Lei; Yu, Peng; Zhao, Lu; Tian, Chungui; Zhao, Dongdong; Zhou, Wei; Yin, Jie; Wang, Ruihong; Fu, Honggang

    2014-01-01

    B,N-codoped carbon nanostructures (BNCS) can serve as alternative low-cost metal-free electrocatalysts for oxygen reduction reactions (ORR). However, the compensation effect between the p- (B atoms) and n-type (N atoms) dopants would make the covalent boron-nitride (BN) easily formed during the synthesis of BNCS, leading to a unsatisfactory ORR activity. Therefore, it has been challenging to develop facile and rapid synthetic strategies for highly active BNCS without forming the direct covalent BN. Here, a facile method is developed to prepare B and N isolate-doped graphitic nanosheets (BNGS) by using iron species for saving N element and simultaneous doping the B element from nitrogen-containing ion-exchanged resins (NR). The resulting BNGS exhibits much more onset potential (Eonset) compared with the B-doped graphitic carbon nanosheets (BGS), N-doped graphitic carbon nanosheets (NGS), as well as B,N-codoped disorder carbon (BNC). Moreover, the BNGS shows well methanol tolerance propery and excellent stability (a minimal loss of activity after 5,000 potential cycles) compared to that of commercial Pt/C catalyst. The goog performance for BNGS towards ORR is attributed to the synergistic effect between B and N, and the well electrons transport property of graphitic carbon in BNGS. PMID:24898033

  12. 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.

  13. The rules of variation: Amino acid exchange according to the rotating circular genetic code

    PubMed Central

    Castro-Chavez, Fernando

    2011-01-01

    General guidelines for the molecular basis of functional variation are presented while focused on the rotating circular genetic code and allowable exchanges that make it resistant to genetic diseases under normal conditions. The rules of variation, bioinformatics aids for preventive medicine, are: (1) same position in the four quadrants for hydrophobic codons, (2) same or contiguous position in two quadrants for synonymous or related codons, and (3) same quadrant for equivalent codons. To preserve protein function, amino acid exchange according to the first rule takes into account the positional homology of essential hydrophobic amino acids with every codon with a central uracil in the four quadrants, the second rule includes codons for identical, acidic, or their amidic amino acids present in two quadrants, and the third rule, the smaller, aromatic, stop codons, and basic amino acids, each in proximity within a 90 degree angle. I also define codifying genes and palindromati, CTCGTGCCGAATTCGGCACGAG. PMID:20371250

  14. Chemically modified polymeric resins for solid-phase extraction and group separation prior to analysis by liquid or gas chromatography

    SciTech Connect

    Schmidt, L.W.

    1993-07-01

    Polystyrene divinylbenzene was modified by acetyl, sulfonic acid, and quaternary ammonium groups. A resin functionalized with an acetyl group was impregnated in a PTFE membrane and used to extract and concentrate phenolic compounds from aqueous samples. The acetyl group created a surface easily wetted, making it an efficient adsorbent for polar compounds in water. The membrane stabilized the resin bed. Partially sulfonated high surface area resins are used to extract and group separate an aqueous mixture of neutral and basic organics; the bases are adsorbed electrostatically to the sulfonic acid groups, while the neutraons are adsorbed hydrophobically. A two-step elution is then used to separate the two fractions. A partially functionalized anion exchange resin is used to separate organic acids and phenols from neutrals in a similar way. Carboxylic acids are analyzed by HPLC and phenols by GC.

  15. Wear-resistant and electromagnetic absorbing behaviors of oleic acid post-modified ferrite-filled epoxy resin composite coating

    NASA Astrophysics Data System (ADS)

    Wang, Wenjie; Zang, Chongguang; Jiao, Qingjie

    2015-03-01

    The post-modified Mn-Zn ferrite was prepared by grafting oleic acid on the surface of Mn-Zn ferrite to inhibit magnetic nanoparticle aggregation. Fourier Transform Infrared (FT-IR) spectroscopy was used to characterize the particle surfaces. The friction and electromagnetic absorbing properties of a thin coating fabricated by dispersing ferrite into epoxy resin (EP) were investigated. The roughness of the coating and water contact angle were measured using the VEECO and water contact angle meter. Friction tests were conducted using a stainless-steel bearing ball and a Rockwell diamond tip, respectively. The complex permittivity and complex permeability of the composite coating were studied in the low frequency (10 MHz-1.5 GHz). Surface modified ferrites are found to improve magnetic particles dispersion in EP resulting in significant compatibility between inorganic and organic materials. Results also indicate that modified ferrite/EP coatings have a lower roughness average value and higher water contact angle than original ferrite/EP coatings. The enhanced tribological properties of the modified ferrite/EP coatings can be seen from the increased coefficient value. The composite coatings with modified ferrite are observed to exhibit better reflection loss compared with the coatings with original ferrite.

  16. 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.

  17. 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.

  18. EXCHANGE

    SciTech Connect

    Boltz, J.C.

    1992-09-01

    EXCHANGE is published monthly by the Idaho National Engineering Laboratory (INEL), a multidisciplinary facility operated for the US Department of Energy (DOE). The purpose of EXCHANGE is to inform computer users about about recent changes and innovations in both the mainframe and personal computer environments and how these changes can affect work being performed at DOE facilities.

  19. Removal of Cr(VI) and As(V) ions from aqueous solutions by polyacrylate and polystyrene anion exchange resins

    NASA Astrophysics Data System (ADS)

    Jachuła, Justyna; Hubicki, Zbigniew

    2013-09-01

    The sorption of Cr(VI) and As(V) from the aqueous solutions with the polyacrylate anion exchangers of the strong base functional groups Amberlite IRA 458 and Amberlite IRA 958 was studied. The studies were carried out by the static-batch method. The concentration of Cr(VI) and As(V) ions in the aqueous solution was determined by the UV-VIS spectrophotometer. The influence of several parameters was studied with respect to sorption equilibrium. The phase contact time and the concentration affect the sorption process. The equilibrium state was established already after 15 min of phase contact time. Maximum uptake of Cr(VI) and As(V) occurred at pH 5 and 10, respectively. The determined kinetic parameters imply that the sorption process proceeds according to the equation type of pseudo second-order. Sorption equilibrium data were correlated with the Langmuir and Freundlich isotherms. Removal of As(V) ions on macroporous Amberlite IRA 900 decreased about 12 % in presence of other anions (Cl-, NO3 -, SO4 2-) in the solution. The sorption was temperature dependent.

  20. Method of continuously forming polyester resins

    SciTech Connect

    Mansour, M.L.

    1984-09-18

    A method of forming a polyester resin from dicarboxylic acid anhydrides and monoepoxides in a specially designed mixing apparatus. The mixing apparatus is a vessel having a centrally disposed vertical draft tube and a centrifugal impeller at the lower end of the draft tube. A plurality of vertical heat exchange tubes surround the draft tube. The reactants are admitted into the vessel and drawn down through the draft tube by the impeller which mixes the reactants and forces the reactants up through the heat exchange tubes. The heat exchange tube portion of the vessel acts as a plug flow reactor, and the upper and lower portions of the vessel act as a back mix reactor. As reactants are admitted into the vessel, product is drawn off from the vessel.