Journal articles: 'Ion exchange processes'

1

Dyer, A. "Ion-exchange processes." TrAC Trends in Analytical Chemistry 10, no. 1 (January 1991): 7–8. http://dx.doi.org/10.1016/0165-9936(91)85037-r.

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Sengupta, Arup K., and Lois Lim. "Modeling chromate ion-exchange processes." AIChE Journal 34, no. 12 (December 1988): 2019–29. http://dx.doi.org/10.1002/aic.690341211.

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Pismenskaya, Natalia, and Victor Nikonenko. "Ion-Exchange Membranes and Processes." Membranes 11, no. 11 (October 26, 2021): 814. http://dx.doi.org/10.3390/membranes11110814.

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4

Kedem, O., and L. Bromberg. "Ion-exchange membranes in extraction processes." Journal of Membrane Science 78, no. 3 (April 1993): 255–64. http://dx.doi.org/10.1016/0376-7388(93)80005-i.

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5

Hajiev, S. N., S. V. Kertman, U. A. Leykin, and A. N. Amelin. "Thermochemical study of ion-exchange processes." Thermochimica Acta 139 (March 1989): 327–32. http://dx.doi.org/10.1016/0040-6031(89)87032-7.

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6

Sherry, Howard. "The design of ion-exchange processes." Zeolites 13, no. 5 (June 1993): 377–83. http://dx.doi.org/10.1016/0144-2449(93)90153-t.

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7

Fernández, A., M. Díaz, and A. Rodrigues. "Kinetic mechanisms in ion exchange processes." Chemical Engineering Journal and the Biochemical Engineering Journal 57, no. 1 (March 1995): 17–25. http://dx.doi.org/10.1016/0923-0467(94)02865-8.

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Pismenskaya, Natalia, and Semyon Mareev. "Ion-Exchange Membranes and Processes (Volume II)." Membranes 11, no. 11 (October 26, 2021): 816. http://dx.doi.org/10.3390/membranes11110816.

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Гомеля, М. Д., A. I. Петриченко, Г. Г. Трохименко, and Я. П. Мартинюк. "Research processes of ion exchange removal phosphates." WATER AND WATER PURIFICATION TECHNOLOGIES. SCIENTIFIC AND TECHNICAL NEWS 21, no. 1 (May 10, 2017): 12–23. http://dx.doi.org/10.20535/2218-93002112017121427.

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10

Ramkumar, Jayshree, and Tulsi Mukherjee. "Role of Ion exchange in permeation processes." Talanta 71, no. 3 (February 28, 2007): 1054–60. http://dx.doi.org/10.1016/j.talanta.2006.05.082.

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11

Slater, M. J. "Ion exchange and sorption processes in hydrometallurgy." Hydrometallurgy 20, no. 1 (March 1988): 131–32. http://dx.doi.org/10.1016/0304-386x(88)90033-3.

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Warner, N. A. "Ion Exchange and Sorption Processes in Hydrometallurgy." Chemical Engineering Science 44, no. 1 (1989): 203–4. http://dx.doi.org/10.1016/0009-2509(89)85249-2.

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13

Marcus, Yizhak. "Ion exchange and sorption processes in hydrometallurgy." Reactive Polymers, Ion Exchangers, Sorbents 9, no. 2 (November 1988): 219–20. http://dx.doi.org/10.1016/0167-6989(88)90035-9.

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14

Jancevičiūtė, Renata, and Audronė Gefenienė. "SORPTION OF COPPER (II) AND NONIONIC SURFACTANT BY ION EXCHANGERS AND ACTIVATED CARBON." JOURNAL OF ENVIRONMENTAL ENGINEERING AND LANDSCAPE MANAGEMENT 14, no. 4 (December 31, 2006): 191–97. http://dx.doi.org/10.3846/16486897.2006.9636897.

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Ion exchange resins, which are widely used for the removal of copper (II) ions from effluents, can also sorb nonionic surfactants entering into the wastewater with copper (II) ions simultaneously after various industrial processes. The study of equilibrium sorption of copper (II) and nonionic surfactant Lutensol AO‐10 under laboratory conditions by different types of ion exchangers and activated carbon has shown that the Purolite S950 chelating ion exchanger has the highest sorption capacity for copper (II) ions. Ion exchangers with carboxylic functional groups demonstrate the highest affinity for nonionic surfactant. Purolite C107E weak acid cation exchanger could be suitable for the cosorption of copper (II) ions and nonionic surfactant Lutensol AO‐10. Kinetic study of this ion exchange resin leads to a conclusion that the sorption of copper (II) ions was a fast process, and after 30 min the equilibrium was attained. When the concentration of copper (II) solution decreases, difference between the sorption capacity of various ion exchangers decrease. The influence of nonionic surfactant on the sorption of copper (II) is insignificant.

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15

Mishchuk, N. A., L. L. Lysenko, and T. A. Nesmeyanova. "Nonstationary processes in an ion-exchange membranes-diaphragm-ion-exchange resin system. 2. Electroosmosis." Colloid Journal 75, no. 6 (November 2013): 690–97. http://dx.doi.org/10.1134/s1061933x13050116.

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Montero-Orille, Carlos, Héctor González-Núñez, Xesús Prieto-Blanco, Vicente Moreno, Dolores Mouriz, María C. Nistal, and Jesús Liñares. "Optimising zero-order suppression in ion-exchanged phase gratings." EPJ Web of Conferences 238 (2020): 03006. http://dx.doi.org/10.1051/epjconf/202023803006.

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Ion-exchange in glass is a well-known technique to fabricate phase optical elements. For elements with reduced dimensions, the side diffusion, intrinsic to ion-exchange processes, can affect the performance of these elements if it is not taken into account. Here we present a procedure to optimise the zero-order suppression of ion-exchanged phase gratings.

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17

Safonyk, Andrij, Ihor Prysiazhniuk, Olena Prysiazhniuk, and Oleksandr Naumchuk. "MATHEMATICAL MODELING SINGULARLY PERTURBED PROCESSES OF WATER SOFTENING ON SODIUM-CATIONITE FILTERS." Informatyka Automatyka Pomiary w Gospodarce i Ochronie Środowiska 9, no. 1 (March 3, 2019): 37–40. http://dx.doi.org/10.5604/01.3001.0013.0901.

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Mathematical model of the process of water softening using ion exchange pre-treatment of waters to desalination, with a view to removal of scale forming components, such as calcium and magnesium, are formed in the paper. In this process, no additional chemicals, except for brines formed during desalination, are required for regeneration of ion-exchanger in operation cycles. An asymptotic approximation of a solution of a corresponding model problem is constructed. Theoretical description and modelling assumptions included the set of differential equations of mass balance, initial, boundary and operational conditions. The paper deals with the development of a computer model for description and prediction of the performance of ion exchange columns.

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Mishchuk, N. A., L. L. Lysenko, T. A. Nesmeyanova, and N. O. Barinova. "Nonstationary processes in an ion-exchange membranes-diaphragm-ion-exchange resin system. 1. Concentration polarization." Colloid Journal 75, no. 6 (November 2013): 677–89. http://dx.doi.org/10.1134/s1061933x13050104.

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19

Ivanenko, V. I., R. I. Korneikov, E. P. Lokshin, and A. M. Petrov. "Ion-Exchange Processes in Deactivated Liquid Radioactive Waste." Ecology and Industry of Russia 22, no. 1 (January 26, 2018): 20–25. http://dx.doi.org/10.18412/1816-0395-2018-1-20-25.

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20

Marsagishvili, T., M. Machavariani, G. Tatishvili, R. Khositashvili, and N. Lekishvili. "Ion-Exchange Processes in the Channels of Zeolites." Asian Journal of Chemistry 25, no. 10 (2013): 5605–6. http://dx.doi.org/10.14233/ajchem.2013.oh33.

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21

Strathmann, H. "Application of ion-exchange membranes in industrial processes." Makromolekulare Chemie. Macromolecular Symposia 70-71, no. 1 (May 1993): 363–77. http://dx.doi.org/10.1002/masy.19930700137.

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22

Audinos, R. "Ion-Exchange membrane processes for clean industrial chemistry." Chemical Engineering & Technology 20, no. 4 (May 1997): 247–58. http://dx.doi.org/10.1002/ceat.270200405.

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23

Dloczik, Larissa, and Rolf Koenenkamp. "Nanostructured metal sulfide surfaces by ion exchange processes." Journal of Solid State Electrochemistry 8, no. 3 (February 1, 2004): 142–46. http://dx.doi.org/10.1007/s10008-003-0427-3.

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24

Trilisky, E. I., and A. M. Lenhoff. "Sorption processes in ion-exchange chromatography of viruses." Journal of Chromatography A 1142, no. 1 (February 2007): 2–12. http://dx.doi.org/10.1016/j.chroma.2006.12.094.

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25

Malovanyy, Myroslav, Kateryna Petrushka, and Ihor Petrushka. "Improvement of Adsorption-Ion-Exchange Processes for Waste and Mine Water Purification." Chemistry & Chemical Technology 13, no. 3 (July 15, 2019): 372–76. http://dx.doi.org/10.23939/chcht13.03.372.

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26

Niftaliev, Sabukhi I., Yuriy S. Peregudov, Olga A. Kozaderova, and Kseniya B. Kim. "ENTHALPY OF INTERACTION OF ION-EXCHANGE HETEROGENEOUS MEMBRANES AND THEIR GRANULAR ANALOGUES WITH AMMONIUM NITRATE SOLUTION." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 59, no. 7 (July 17, 2018): 29. http://dx.doi.org/10.6060/tcct.20165907.5391.

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Ion-exchange membranes are widely used for extraction, separation and concentration of aqueous nitrogen-containing solutions. In the study the heterogeneous ion-exchange membranes of cationic type- MK-40, Ralex CM (H) -PP, MK-41 – and anionic type - MA-41, Ralex AM (H) -PP and also their granular analogues – cation exchanger KУ-2·8 and anion exchanger AB-17·8 were used. Sorption of nitrate ions and ammonium ions was conducted from the ammonium nitrate solution with concentration of 0.012 mole / dm³. To determine sorption thermochemical characteristics of the studied ions the calorimetric method was used. It was found that for all the studied types of membranes and ion exchangers the processes were accompanied by heat evolution. From the calorimetric measurements the thermokinetic interaction curves of cation-exchange membranes and KУ-2×8 with the ammonium nitrate solution and anion-exchange membranes and AB-17×8 with the solution of the same salt were obtained. According to the curves the power of heat evolution and time of the process were determined. It was shown that the ion exchangers KУ-2·8 and AB-17·8 are characterized by a longer time to achieve the maximum of heat evolution and process time than for the similar membranes. This fact is explained by the different number and accessibility of the functional groups in the membranes and ion exchangers. From the thermo-kinetic curves the enthalpies of interaction were calculated. The process of the interaction between the granular ion exchangers and ions is characterized by higher values of the enthalpy than for the membranes which large steric effects are common for. Saline concentration, nature of exchangeable ions and type of functional groups of the ion exchanger and also its moisture content influence the enthalpy value. Experimental calorimetric data indicated that the energy costs connected with the effects of dehydration and conformational changes in the sorbent polymer chains do not overlap the exothermic sorption effect. The calorimetric method is informative to determine the nature and mechanism of sorption.

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27

Righini, Giancarlo C., and Jesús Liñares. "Active and Quantum Integrated Photonic Elements by Ion Exchange in Glass." Applied Sciences 11, no. 11 (June 4, 2021): 5222. http://dx.doi.org/10.3390/app11115222.

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Ion exchange in glass has a long history as a simple and effective technology to produce gradient-index structures and has been largely exploited in industry and in research laboratories. In particular, ion-exchanged waveguide technology has served as an excellent platform for theoretical and experimental studies on integrated optical circuits, with successful applications in optical communications, optical processing and optical sensing. It should not be forgotten that the ion-exchange process can be exploited in crystalline materials, too, and several crucial devices, such as optical modulators and frequency doublers, have been fabricated by ion exchange in lithium niobate. Here, however, we are concerned only with glass material, and a brief review is presented of the main aspects of optical waveguides and passive and active integrated optical elements, as directional couplers, waveguide gratings, integrated optical amplifiers and lasers, all fabricated by ion exchange in glass. Then, some promising research activities on ion-exchanged glass integrated photonic devices, and in particular quantum devices (quantum circuits), are analyzed. An emerging type of passive and/or reconfigurable devices for quantum cryptography or even for specific quantum processing tasks are presently gaining an increasing interest in integrated photonics; accordingly, we propose their implementation by using ion-exchanged glass waveguides, also foreseeing their integration with ion-exchanged glass lasers.

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28

Poltavtsev, V. I. "Continuous processes of ion-exchange catalysis, extraction, and ion exchanger regeneration, and the related technological features." Pharmaceutical Chemistry Journal 30, no. 1 (January 1996): 53–54. http://dx.doi.org/10.1007/bf02218930.

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29

Howden, M. "Radioactive Effluent Treatment Plant—Sellafield Reprocessing Factory." Proceedings of the Institution of Mechanical Engineers, Part A: Power and Process Engineering 201, no. 1 (February 1987): 1–15. http://dx.doi.org/10.1243/pime_proc_1987_201_002_02.

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This paper outlines the reprocessing of spent radioactive fuel at the British Nuclear Fuels plant, Sellafield, and describes the development, construction and commissioning of a new site ion exchange effluent plant (SIXEP). Gives details of the processes involved including the ion exchange columns, the ion exchanger, the carbonating tower, the waste storage tanks, the tank emptying system, and pumps and valves Reviews the initial operation of the plant and discusses future developments in radioactive waste treatment.

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Zhang, Shaoling, Akihiko Tanioka, and Hidetoshi Matsumoto. "De Novo Ion-Exchange Membranes Based on Nanofibers." Membranes 11, no. 9 (August 25, 2021): 652. http://dx.doi.org/10.3390/membranes11090652.

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The unique functions of nanofibers (NFs) are based on their nanoscale cross-section, high specific surface area, and high molecular orientation, and/or their confined polymer chains inside the fibers. The introduction of ion-exchange (IEX) groups on the surface and/or inside the NFs provides de novo ion-exchangers. In particular, the combination of large surface areas and ionizable groups in the IEX-NFs improves their performance through indices such as extremely rapid ion-exchange kinetics and high ion-exchange capacities. In reality, the membranes based on ion-exchange NFs exhibit superior properties such as high catalytic efficiency, high ion-exchange and adsorption capacities, and high ionic conductivities. The present review highlights the fundamental aspects of IEX-NFs (i.e., their unique size-dependent properties), scalable production methods, and the recent advancements in their applications in catalysis, separation/adsorption processes, and fuel cells, as well as the future perspectives and endeavors of NF-based IEMs.

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31

Maltseva, Tetiana, Eugene Kolomiets, and Yulliya Dzyazko. "ELECTRICAL CONDUCTIVITY AND SORPTION PROPERTIES OF THE COMPOSITES BASED ON ION EXCHANGE POLYMERS." Ukrainian Chemistry Journal 85, no. 4 (June 7, 2019): 81–97. http://dx.doi.org/10.33609/0041-6045.85.4.2019.81-97.

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The review is devoted to the conditions for the creation and functional properties of organіс-inorganic ion-exchange materials, which in the form of sorbents and membranes can be applied in the processes of ion separation, as well as the purification of water and combined solutions of technological origin. The structure of air dry and hydrated organic ion-exchange polymers, conditions for the creation of organiс-inorganic ion-exchange materials, as well as their components, interaction of components and the corresponding classification are considered. Dry ion-exchange materials contain heterogeneities of different sizes, which are formed during the synthesis of polymer, with the smallest heterogeneities represent clusters, and the larger ones are related to crystallinity. The structure of hydrated ion- exchange materials adequately describes the cluster channel model of Hsu and Girke. The number of charged particles transferred corresponds to the contribution of clusters and channels (volume fractions) to total porosity. The size of the clusters and channels can be determined by the method of small-angle X-ray scattering. The complex porous structure of ion-exchange polymers makes it possible to form inorganic particles in the one’s pores. The introduction of inorganic ion exchangers into the polymer leads to the appearance of additional osmotically active centers (fixed ions and antimony modifiers) that influence the compression pressure of composites. Regarding the functional properties of organiс-inorganic materials, data on the influence of the form and size of the nanoparticles of the inorganic component on the electrical conductivity of composites, examples of the use of organiс-inorganic sorbents in ion-exchange columns, and also effective diffusion coefficients corresponding to the exchange of two-charge metal cations (Zn2+, Pb2+, Cu2+, Ca2+, Ni2+) on H+ organic-inorganic sorbents, for the most part, organic resin- Dowex HCR-S with incorporated particles of zirconium hydrophosphate, are presented. The prospect of application of such materials in ion-exchange and membrane processes of separation and purification of aqueous solutions, as well as in the processes of efficient selective extraction of target ions, is shown.

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Ostapova, Elena V., Sergey Yu Lyrschikov, and Heinrich N. Altshuler. "Equilibrium constants of the sorption of pyridinecarboxylic acids by polystyrene type sulfocationite." Butlerov Communications 64, no. 10 (October 31, 2020): 55–62. http://dx.doi.org/10.37952/roi-jbc-01/20-64-10-55.

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The processes of sorption of pyridine-3-carboxylic (nicotinic) and pyridine-4-carboxylic (isonicotinic) acids by sulfonic acid cation exchangers of the polystyrene type (CU-2-4 and CU-2-8) from aqueous solutions with different pH values were studied. Analysis of the FTIR spectra of isonicotinic acid, isonicotinic acid sulfate, and CU-2-8 sulfonic cation exchanger filled with isonicotinic acid showed that pyridinecarboxylic acid is in the protonated form in the polymer phase. Experimental data of the equilibrium distribution of acids in the aqueous solution-cation exchange system have been obtained. The values of the equilibrium constants for ion exchange and ligand sorption processes involving various forms of pyridinecarboxylic acid, sulfonic cation exchanger, and protons were calculated. The equilibrium constants for the ion exchange of sulfocationite protons by pyridinecarboxylic acid cations from solution are in the range 3.3-4.4. The selectivity of sulfonic cation exchangers to cations increases in the sequences proton < nicotinic acid cation < isonicotinic acid cation. The values of the equilibrium constant for ligand sorption of molecules are 195-220 dm3/mol for isonicotinic acid and reach 320-330 dm3/mol for nicotinic acid, i.e. the sorption activity of the H-form of the cation exchanger is higher in relation to nicotinic acid molecules. A change in the amount of a crosslinking agent (from 4% to 8% divinylbenzene) in a polystyrene type sulfonic cation exchanger does not significantly affect its sorption activity towards pyridinecarboxylic acids.

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33

Stenina, Irina A., and Andrey B. Yaroslavtsev. "Ionic Mobility in Ion-Exchange Membranes." Membranes 11, no. 3 (March 11, 2021): 198. http://dx.doi.org/10.3390/membranes11030198.

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Membrane technologies are widely demanded in a number of modern industries. Ion-exchange membranes are one of the most widespread and demanded types of membranes. Their main task is the selective transfer of certain ions and prevention of transfer of other ions or molecules, and the most important characteristics are ionic conductivity and selectivity of transfer processes. Both parameters are determined by ionic and molecular mobility in membranes. To study this mobility, the main techniques used are nuclear magnetic resonance and impedance spectroscopy. In this comprehensive review, mechanisms of transfer processes in various ion-exchange membranes, including homogeneous, heterogeneous, and hybrid ones, are discussed. Correlations of structures of ion-exchange membranes and their hydration with ion transport mechanisms are also reviewed. The features of proton transfer, which plays a decisive role in the membrane used in fuel cells and electrolyzers, are highlighted. These devices largely determine development of hydrogen energy in the modern world. The features of ion transfer in heterogeneous and hybrid membranes with inorganic nanoparticles are also discussed.

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34

Zerdoumi, Ridha, Kafia Oulmi, and Salah Benslimane. "Enhancement of counter-ion transport through ion-exchange membranes in electrodialytic processes." Desalination and Water Treatment 56, no. 10 (October 17, 2014): 2631–36. http://dx.doi.org/10.1080/19443994.2014.972734.

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35

SENO, Manabu, and Kazutoshi IWAMOTO. "Recent developments on ion-exchange membrane processes; Progress report." membrane 10, no. 5 (1985): 289–96. http://dx.doi.org/10.5360/membrane.10.289.

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36

Bogatyryov, V. L. "Effect of high pressures on ion-exchange chromatographic processes." Journal of Chromatography A 364 (September 1986): 125–33. http://dx.doi.org/10.1016/s0021-9673(00)96202-2.

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37

TAKAHASHI, Hiroshi. "Development of Separation Processes Accompanied by Ion-exchange Reaction." Journal of Ion Exchange 24, no. 3 (2013): 61–67. http://dx.doi.org/10.5182/jaie.24.61.

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38

FUH, WEA-SHANG, and BEEN-HUANG CHIANG. "Purification of Steviosides by Membrane and Ion Exchange Processes." Journal of Food Science 55, no. 5 (September 1990): 1454–57. http://dx.doi.org/10.1111/j.1365-2621.1990.tb03956.x.

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39

Hübsch, E., G. Fleith, J. Fatisson, P. Labbé, J. C. Voegel, P. Schaaf, and V. Ball. "Multivalent Ion/Polyelectrolyte Exchange Processes in Exponentially Growing Multilayers." Langmuir 21, no. 8 (April 2005): 3664–69. http://dx.doi.org/10.1021/la047258d.

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Al-Jibbouri, Sattar. "Scale-up of chromatographic ion-exchange processes in biotechnology." Journal of Chromatography A 1116, no. 1-2 (May 2006): 135–42. http://dx.doi.org/10.1016/j.chroma.2006.03.033.

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Sata, T. "Ion exchange membranes and separation processes with chemical reactions." Journal of Applied Electrochemistry 21, no. 4 (April 1991): 283–94. http://dx.doi.org/10.1007/bf01020210.

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Prieto-Blanco, Xesús, and Carlos Montero-Orille. "Theoretical Modelling of Ion Exchange Processes in Glass: Advances and Challenges." Applied Sciences 11, no. 11 (May 30, 2021): 5070. http://dx.doi.org/10.3390/app11115070.

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In the last few years, some advances have been made in the theoretical modelling of ion exchange processes in glass. On the one hand, the equations that describe the evolution of the cation concentration were rewritten in a more rigorous manner. This was made into two theoretical frameworks. In the first one, the self-diffusion coefficients were assumed to be constant, whereas, in the second one, a more realistic cation behaviour was considered by taking into account the so-called mixed ion effect. Along with these equations, the boundary conditions for the usual ion exchange processes from molten salts, silver and copper films and metallic cathodes were accordingly established. On the other hand, the modelling of some ion exchange processes that have attracted a great deal of attention in recent years, including glass poling, electro-diffusion of multivalent metals and the formation/dissolution of silver nanoparticles, has been addressed. In such processes, the usual approximations that are made in ion exchange modelling are not always valid. An overview of the progress made and the remaining challenges in the modelling of these unique processes is provided at the end of this review.

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43

Sayee Kannan, R., S. Siva, K. Kavitha, and N. Kannan. "Phenol and Formaldehyde Cationic Resin Blended with Sulphonated Aegle Marmelos Charcoal." Materials Science Forum 699 (September 2011): 281–91. http://dx.doi.org/10.4028/www.scientific.net/msf.699.281.

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This paper represents a simple method for preparing and characterizing of low-cost ion exchangers of sulfonated carbon prepared from Aegle Marmelos., as a source of cheap plant material blended with phenol-formaldehyde as a cross linking agent. The prepared ion exchange resins (IERS) are characterized by infrared (IR) spectral and thermal studies. All the important physico chemical properties of the ion exchangers have been determined. It is concluded from the present study that PER sample could be blended with 30% (W/W) of sulfonated Aegle Marmelos charcoal (SAMC) without affecting its physico chemical, spectral and thermal properties. Hence blending with SAMC will be finitely lower the cost of the ion exchange resin. Ion exchange process is suitable in the treatment of waste water containing metal ions discharge from plating and other industries. Also, it is a convenient way to concentrate and remove the ions of valuable metals like copper, mercury, cadmium, Nickel and Barium special processes using selective IERS are also available for the recovery of precisious noble metals like gold, platinum and silver. The present study is aimed at to synthesize and characterize new composite ion exchangers of PhOH – HCHO type, blended with SAMC and to determine the column/cation exchange capacity (or) ion exchange capacity (IEC) for some selective metal ions.

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44

Shibukawa, Masami, Tomomi Shimasaki, Shingo Saito, and Takashi Yarita. "Superheated Water Ion-Exchange Chromatography: An Experimental Approach for Interpretation of Separation Selectivity in Ion-Exchange Processes." Analytical Chemistry 81, no. 19 (October 2009): 8025–32. http://dx.doi.org/10.1021/ac9011864.

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45

Rogoziński. "Stresses Produced in the BK7 Glass by the K+–Na+ Ion Exchange: Real-Time Process Control Method." Applied Sciences 9, no. 12 (June 21, 2019): 2548. http://dx.doi.org/10.3390/app9122548.

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The paper presents the results of tests on stresses produced by the K+↔Na+ ion exchange method in BK7 glass. Diffusion ion exchange processes were carried out in glass plates with a surface area of a few cm2. The duration of these processes ranged from several hours to several hundred hours; process temperatures from 370 to 402 degree Celsius were used. The area of the glass in which the ion exchange took place shows refractive changes which are also accompanied by stresses. The planar waveguides produced in this way were tested by optical methods (for wavelength = 677 nm) and the refractive index profiles for the Transverse Electric (TE)and Transverse Magnetic (TM) olarization states were determined. On the basis of elasto-optic constants, the resulting stresses were determined. The temperature characteristics of diffusion coefficients of exchanged ions were also determined. Based on them a numerical simulation of real-time diffusion processes was possible, which allowed to predict the stresses arising in the glass. A good agreement between these predictions and the results of measurements was obtained.

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46

Pedregal Montes, Angela Isabel, Janith Abeywickrama, Nils Hoth, Marlies Grimmer, and Carsten Drebenstedt. "Modeling of Ion Exchange Processes to Optimize Metal Removal from Complex Mine Water Matrices." Water 13, no. 21 (November 4, 2021): 3109. http://dx.doi.org/10.3390/w13213109.

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The modeling of ion exchange processes could significantly enhance their applicability in mine water treatment, as the modern synthetic resins give unique advantages for the removal of metals. Accurate modeling improves the predictability of the process, minimizing the time and costs involved in laboratory column testing. However, to date, the development and boundary conditions of such ion exchange systems with complex mine waters are rarely studied and poorly understood. A representative ion exchange model requires the definition of accurate parameters and coefficients. Therefore, theoretical coefficients estimated from natural exchange materials that are available in geochemical databases often need to be modified. A 1D reactive transport model was developed based on PhreeqC code, using three case scenarios of synthetic mine waters and varying the operating conditions. The first approach was defined with default exchange coefficients from the phreeqc.dat database to identify and study the main parameters and coefficients that govern the model: cation exchange capacity, exchange coefficients, and activity coefficients. Then, these values were adjusted through iterative calibration until a good approximation between experimental and simulation breakthrough curves was achieved. This study proposes a suitable methodology and challenges for modeling the removal of metals from complex mine waters using synthetic ion exchange resins.

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Petrov, Oleksandr, Natalia Iwaszczuk, Irina Bejanidze, Tina Kharebava, Volodymyr Pohrebennyk, Nato Didmanidze, and Nunu Nakashidze. "Study of the Electrical Conductivity of Ion-Exchange Resins and Membranes in Equilibrium Solutions of Inorganic Electrolytes." Membranes 12, no. 2 (February 20, 2022): 243. http://dx.doi.org/10.3390/membranes12020243.

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The study of the electrical conductivity of ion-exchange membranes in equilibrium electrolyte solutions is of great importance for the theory of membrane processes, in particular for practical electrodialysis. The purpose of the work is to determine the electrical conductivity of industrial ion-exchange membranes MK-40 and MA-40, as well as their basis—granules of a bulk layer of industrial ion exchangers KU-2-8 and EDE-10p, by differential and modified contact methods in electrolyte solutions and the development of a new methodology that will give the values that are closest to the true ones; determination of the dependence of electrical membrane conductivity depending on the type of counterion and concentration equilibrium solution and granules of a bulk layer of ion exchangers on the volume fraction of a dry ion exchanger with different degrees of compaction. It is shown that the dependence of the electrical conductivity of diaphragms on the electrolyte concentration, according to theoretical ideas, disappears under compression. It has been experimentally established that the difference method gives lower values of electrical conductivity in the region of low concentrations. The data obtained by the contact method are in good agreement with the results obtained for compressed diaphragms. The membrane conductivity decreases with increasing ion size.

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Mukhtarova, Nigora, Bakhodir Aliev, Sadritdin Turabdzhanov, and Latofat Rakhimova. "Studies of factors affecting stability and efficiency of anion exchanger." E3S Web of Conferences 177 (2020): 03020. http://dx.doi.org/10.1051/e3sconf/202017703020.

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Various industries such as mining and the chemical industry are one of the most used ion exchange processes for water and wastewater treatment. The first section of this work presents the mechanism of the polycondensation reaction to obtain the polymer matrix of anion exchanger. Elemental analytical data conformed that anion exchanger holds 34,99% of nitrogen atoms and 44,47% oxygen atoms in the structure. In addition to the synthesis of the anion exchanger, physicochemical factors have a significant effect. The temperature of reactions for a certain time using a Lewis catalyst, the choice of the optimal solvent for improving swelling capacity of the starting monomers, due to their advantages as effective materials at a low price, are described in the second section. The information in the last section of the paper is devoted to the sorption properties and the ion-exchange processes in where the obtained anion exchanger was studied and used.

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Ko, Tae Ho, Jun Seong Yun, Tae Yang Son, and Sang Yong Nam. "Preparation and Characterization of Pore Filled Hybrid Composite Membrane Composed of Cation Exchange Materials and Polyethylene Support." Journal of Nanoscience and Nanotechnology 20, no. 11 (November 1, 2020): 6802–6. http://dx.doi.org/10.1166/jnn.2020.18789.

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This study investigated ion exchange membranes for application to seawater desalination processes. This can provide better energy efficiency than the conventional reverse osmosis process. In this experiment, the problem of decreasing ion exchange performance when the ion exchange composite membrane was prepared could be improved through nanoparticles. The nanoparticle added ion exchange hybrid membrane showed ion exchange capacity similar to that of the conventional pristine film. In addition, the polymer having a high ion exchange capacity has poor mechanical strength, but has excellent mechanical strength of 30 MPa or more by the introduction of a polyethylene support.

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Singha, Kamini, Li Li, Frederick D. Day-Lewis, and Aaron B. Regberg. "Quantifying solute transport processes: Are chemically “conservative” tracers electrically conservative?" GEOPHYSICS 76, no. 1 (January 2011): F53—F63. http://dx.doi.org/10.1190/1.3511356.

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The concept of a nonreactive or conservative tracer, commonly invoked in investigations of solute transport, requires additional study in the context of electrical geophysical monitoring. Tracers that are commonly considered conservative may undergo reactive processes, such as ion exchange, thus changing the aqueous composition of the system. As a result, the measured electrical conductivity may reflect not only solute transport but also reactive processes. We have evaluated the impacts of ion exchange reactions, rate-limited mass transfer, and surface conduction on quantifying tracer mass, mean arrival time, and temporal variance in laboratory-scale column experiments. Numerical examples showed that (1) ion exchange can lead to resistivity-estimated tracer mass, velocity, and dispersivity that may be inaccurate; (2) mass transfer leads to an overestimate in the mobile tracer mass and an underestimate in velocity when using electrical methods; and (3) surface conductance does not notably affect estimated moments when high-concentration tracers are used, although this phenomenon may be important at low concentrations or in sediments with high and/or spatially variable cation-exchange capacity. In all cases, colocated groundwater concentration measurements are of high importance for interpreting geophysical data with respect to the controlling transport processes of interest.

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Journal articles on the topic 'Ion exchange processes'

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