Electrochemical characteristics of thin heterogeneous ion exchange membranes

Козадерова, О. А.; Kim, K. B.; Gadzhiyeva, C. S.; Нифталиев, С. И.

doi:10.1016/j.memsci.2020.118081

Cited by 17 publications

(10 citation statements)

References 14 publications

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“…Standard procedure for determining the limiting current density (i lim exp ) is shown at Figure 11b. The CVC of a pristine membrane in model solution 1 (Figure 11a), which contains only a mixture of KCl and KHT, has the traditional shape described in much research [62,[67][68][69]. The curve contains the initial section I, the section of the inclined plateau II and the "overlimiting" section III.…”

Section: Current-voltage Curves Of the Cjma-6 Membrane Before And Aft...mentioning

confidence: 97%

Electrodialysis Tartrate Stabilization of Wine Materials: Fouling and a New Approach to the Cleaning of Aliphatic Anion-Exchange Membranes

et al. 2022

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Electrodialysis (ED) is an attractive method of tartrate stabilization of wine due to its rapidity and reagentlessness. At the same time, fouling of ion-exchange membranes by the components of wine materials is still an unsolved problem. The effect of ethanol, polyphenols (mainly anthocyanins and proanthocyanidins) and saccharides (fructose) on the fouling of aliphatic ion-exchange membranes CJMA-6 and CJMC-5 (manufactured by Hefei Chemjoy Polymer Materials Co. Ltd., Hefei, China) was analyzed using model solutions. It was shown that the mechanism and consequences of fouling are different in the absence of an electric field and during electrodialysis. In particular, a layer of colloidal particles is deposited on the surface of the CJMA-6 anion-exchange membrane in underlimiting current modes. Its thickness increases with increasing current density, apparently due to the implementation of a trap mechanism involving tartaric acid anions, as well as protons, which are products of water splitting and “acid dissociation”. A successful attempt was made to clean CJMA-6 in operando by pumping a water-alcohol solution of KCl through the desalination compartment and changing electric field direction. It has been established that such a cleaning process suppresses the subsequent biofouling of ion-exchange membranes. In addition, selective recovery of polyphenols with high antioxidant activity is possible.

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Section: Current-voltage Curves Of the Cjma-6 Membrane Before And Aft...mentioning

confidence: 97%

Electrodialysis Tartrate Stabilization of Wine Materials: Fouling and a New Approach to the Cleaning of Aliphatic Anion-Exchange Membranes

et al. 2022

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“…Using analogy with strong electrolytes, many researchers explain the relatively low current efficiency [ 126 , 181 ] and high energy consumption [ 126 , 192 ], as well as the problems with achieving high concentrations of ammonium cations in ED concentration compartments by the insufficient selectivity of CEMs, for which NH 4 + is counterion [ 179 , 190 , 191 ]. Indeed, an increase in selectivity and a decrease in the diffusion permeability of CEM lead to a decrease in the ammonium cations fluxes [ 231 ] and a decrease in energy consumption for the ED recovery of ammonium salts [ 232 ]. At the same time, the so-called “facilitated” diffusion of ammonium cations through AEM [ 169 , 205 , 233 ] ( Figure 22 b) can also significantly affect the mass transfer characteristics of the membrane systems with ammonium-containing solutions.…”

Section: Fundamentals Of Phosphates and Ammonia Transport In Electrom...mentioning

confidence: 99%

Recovery of Nutrients from Residual Streams Using Ion-Exchange Membranes: Current State, Bottlenecks, Fundamentals and Innovations

2022

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The review describes the place of membrane methods in solving the problem of the recovery and re-use of biogenic elements (nutrients), primarily trivalent nitrogen NIII and pentavalent phosphorus PV, to provide the sustainable development of mankind. Methods for the recovery of NH4+ − NH3 and phosphates from natural sources and waste products of humans and animals, as well as industrial streams, are classified. Particular attention is paid to the possibilities of using membrane processes for the transition to a circular economy in the field of nutrients. The possibilities of different methods, already developed or under development, are evaluated, primarily those that use ion-exchange membranes. Electromembrane methods take a special place including capacitive deionization and electrodialysis applied for recovery, separation, concentration, and reagent-free pH shift of solutions. This review is distinguished by the fact that it summarizes not only the successes, but also the “bottlenecks” of ion-exchange membrane-based processes. Modern views on the mechanisms of NH4+ − NH3 and phosphate transport in ion-exchange membranes in the presence and in the absence of an electric field are discussed. The innovations to enhance the performance of electromembrane separation processes for phosphate and ammonium recovery are considered.

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“…There are a number of studies pointing to increased water splitting at anion-exchange membranes (AEMs) in ammonia-containing solutions [ 19 , 20 , 21 , 22 ]; in addition, the AEM permeability for ammonium ions is higher than for other anions [ 22 , 23 ]. The results of these studies allow us to suggest that the specific behavior of AEMs in ammonium-containing solutions is due to protonation–deprotonation reactions involving nitrogen ammonia species, which are coupled with a pH shift in these membranes in relation to the pH of the external solution.…”

Section: Introductionmentioning

confidence: 99%

High Diffusion Permeability of Anion-Exchange Membranes for Ammonium Chloride: Experiment and Modeling

Skolotneva

Tsygurina

Mareev

et al. 2022

IJMS

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It is known that ammonium has a higher permeability through anion exchange and bipolar membranes compared to K+ cation that has the same mobility in water. However, the mechanism of this high permeability is not clear enough. In this study, we develop a mathematical model based on the Nernst–Planck and Poisson’s equations for the diffusion of ammonium chloride through an anion-exchange membrane; proton-exchange reactions between ammonium, water and ammonia are taken into account. It is assumed that ammonium, chloride and OH− ions can only pass through membrane hydrophilic pores, while ammonia can also dissolve in membrane matrix fragments not containing water and diffuse through these fragments. It is found that due to the Donnan exclusion of H+ ions as coions, the pH in the membrane internal solution increases when approaching the membrane side facing distilled water. Consequently, there is a change in the principal nitrogen-atom carrier in the membrane: in the part close to the side facing the feed NH4Cl solution (pH < 8.8), it is the NH4+ cation, and in the part close to distilled water, NH3 molecules. The concentration of NH4+ reaches almost zero at a point close to the middle of the membrane cross-section, which approximately halves the effective thickness of the diffusion layer for the transport of this ion. When NH3 takes over the nitrogen transport, it only needs to pass through the other half of the membrane. Leaving the membrane, it captures an H+ ion from water, and the released OH− moves towards the membrane side facing the feed solution to meet the NH4+ ions. The comparison of the simulation with experiment shows a satisfactory agreement.

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Electrochemical characteristics of thin heterogeneous ion exchange membranes

Cited by 17 publications

References 14 publications

Electrodialysis Tartrate Stabilization of Wine Materials: Fouling and a New Approach to the Cleaning of Aliphatic Anion-Exchange Membranes

Electrodialysis Tartrate Stabilization of Wine Materials: Fouling and a New Approach to the Cleaning of Aliphatic Anion-Exchange Membranes

Recovery of Nutrients from Residual Streams Using Ion-Exchange Membranes: Current State, Bottlenecks, Fundamentals and Innovations

High Diffusion Permeability of Anion-Exchange Membranes for Ammonium Chloride: Experiment and Modeling

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