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Ramirez P, Cervera J, Nasir S, Ali M, Ensinger W, Mafe S. Electrochemical impedance spectroscopy of membranes with nanofluidic conical pores. J Colloid Interface Sci 2024; 655:876-885. [PMID: 37979293 DOI: 10.1016/j.jcis.2023.11.060] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 10/31/2023] [Accepted: 11/09/2023] [Indexed: 11/20/2023]
Abstract
Electrochemical impedance spectroscopy (EIS) constitutes a useful tool in membrane science and technology because it provides valuable structural and functional information. The different arcs observed in the impedance spectra permit to decouple and understand distinct physico-chemical phenomena occurring under operating conditions. By using EIS techniques, we have characterized here multipore asymmetric membranes with conical pores that exhibit a broad range of ionic conduction properties, including current rectification. These properties can be modulated by tuning the electrical interaction between the charges functionalized on the pore surface and the nanoconfined ionic solution. In particular, the membrane electrical response is studied as a function of the amplitude and frequency of the external voltage signal, the electrolyte type and concentration, and the solution pH. Remarkably, significant chemical inductance effects are observed. The scalability and biocompatibility of these pores suggest good potential for use in hybrid biodevices and interfaces.
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Affiliation(s)
- Patricio Ramirez
- Departament de Física Aplicada, Universitat Politècnica de València, E-46022 València, Spain.
| | - Javier Cervera
- Departament de Física de la Terra i Termodinàmica, Universitat de València, E-46100 Burjassot, Spain
| | - Saima Nasir
- Materials Research Department, GSI Helmholtzzentrum für Schwerionenforschung, D-64291 Darmstadt, Germany; Department of Material- and Geo-Sciences, Technische Universität Darmstadt, D-64287 Darmstadt, Germany
| | - Mubarak Ali
- Materials Research Department, GSI Helmholtzzentrum für Schwerionenforschung, D-64291 Darmstadt, Germany; Department of Material- and Geo-Sciences, Technische Universität Darmstadt, D-64287 Darmstadt, Germany
| | - Wolfgang Ensinger
- Department of Material- and Geo-Sciences, Technische Universität Darmstadt, D-64287 Darmstadt, Germany
| | - Salvador Mafe
- Departament de Física Aplicada, Universitat Politècnica de València, E-46022 València, Spain; Departament de Física de la Terra i Termodinàmica, Universitat de València, E-46100 Burjassot, Spain
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Pismenskaya N, Rybalkina O, Solonchenko K, Butylskii D, Nikonenko V. Phosphates Transfer in Pristine and Modified CJMA-2 Membrane during Electrodialysis Processing of Na xH (3-x)PO 4 Solutions with pH from 4.5 to 9.9. MEMBRANES 2023; 13:647. [PMID: 37505013 PMCID: PMC10386648 DOI: 10.3390/membranes13070647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 06/27/2023] [Accepted: 07/03/2023] [Indexed: 07/29/2023]
Abstract
Phosphate recovery from different second streams using electrodialysis (ED) is a promising step to a nutrients circular economy. However, the relatively low ED performance hinders the widespread adoption of this environmentally sound method. The formation of "bonded species" between phosphates and the weakly basic fixed groups (primary and secondary amines) of the anion exchange membrane can be the cause of decrease in current efficiency and increase in energy consumption. ED processing of NaxH(3-x)PO4 alkaline solutions and the use of intense current modes promote the formation of a bipolar junction from negatively charged bound species and positively charged fixed groups. This phenomenon causes a change in the shape of current-voltage curves, increase in resistance, and an enhancement in proton generation during long-term operation of anion-exchange membrane with weakly basic fixed groups. Shielding of primary and secondary amines with a modifier containing quaternary ammonium bases significantly improves ED performance in the recovery of phosphates from NaxH(3-x)PO4 solution with pH 4.5. Indeed, in the limiting and underlimiting current modes, 40% of phosphates are recovered 1.3 times faster, and energy consumption is reduced by 1.9 times in the case of the modified membrane compared to the pristine one. Studies were performed using a new commercial anion exchange membrane CJMA-2.
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Affiliation(s)
- Natalia Pismenskaya
- Russian Federation, Kuban State University, 149, Stavropolskaya Str., 350040 Krasnodar, Russia
| | - Olesya Rybalkina
- Russian Federation, Kuban State University, 149, Stavropolskaya Str., 350040 Krasnodar, Russia
| | - Ksenia Solonchenko
- Russian Federation, Kuban State University, 149, Stavropolskaya Str., 350040 Krasnodar, Russia
| | - Dmitrii Butylskii
- Russian Federation, Kuban State University, 149, Stavropolskaya Str., 350040 Krasnodar, Russia
| | - Victor Nikonenko
- Russian Federation, Kuban State University, 149, Stavropolskaya Str., 350040 Krasnodar, Russia
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Pismenskaya N, Rybalkina O, Solonchenko K, Pasechnaya E, Sarapulova V, Wang Y, Jiang C, Xu T, Nikonenko V. How Chemical Nature of Fixed Groups of Anion-Exchange Membranes Affects the Performance of Electrodialysis of Phosphate-Containing Solutions? Polymers (Basel) 2023; 15:polym15102288. [PMID: 37242863 DOI: 10.3390/polym15102288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 05/03/2023] [Accepted: 05/09/2023] [Indexed: 05/28/2023] Open
Abstract
Innovative ion exchange membranes have become commercially available in recent years. However, information about their structural and transport characteristics is often extremely insufficient. To address this issue, homogeneous anion exchange membranes with the trade names ASE, CJMA-3 and CJMA-6 have been investigated in NaxH(3-x)PO4 solutions with pH 4.4 ± 0.1, 6.6 and 10.0 ± 0.2, as well as NaCl solutions with pH 5.5 ± 0.1. Using IR spectroscopy and processing the concentration dependences of the electrical conductivity of these membranes in NaCl solutions, it was shown that ASE has a highly cross-linked aromatic matrix and mainly contains quaternary ammonium groups. Other membranes have a less cross-linked aliphatic matrix based on polyvinylidene fluoride (CJMA-3) or polyolefin (CJMA-6) and contain quaternary amines (CJMA-3) or a mixture of strongly basic (quaternary) and weakly basic (secondary) amines (CJMA-6). As expected, in dilute solutions of NaCl, the conductivity of membranes increases with an increase in their ion-exchange capacity: CJMA-6 < CJMA-3 << ASE. Weakly basic amines appear to form bound species with proton-containing phosphoric acid anions. This phenomenon causes a decrease in the electrical conductivity of CJMA-6 membranes compared to other studied membranes in phosphate-containing solutions. In addition, the formation of the neutral and negatively charged bound species suppresses the generation of protons by the "acid dissociation" mechanism. Moreover, when the membrane is operated in overlimiting current modes and/or in alkaline solutions, a bipolar junction is formed at the CJMA- 6/depleted solution interface. The CJMA-6 current-voltage curve becomes similar to the well-known curves for bipolar membranes, and water splitting intensifies in underlimiting and overlimiting modes. As a result, energy consumption for electrodialysis recovery of phosphates from aqueous solutions almost doubles when using the CJMA-6 membrane compared to the CJMA-3 membrane.
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Affiliation(s)
- Natalia Pismenskaya
- Russian Federation, Kuban State University, 149, Stavropolskaya Str., 350040 Krasnodar, Russia
| | - Olesya Rybalkina
- Russian Federation, Kuban State University, 149, Stavropolskaya Str., 350040 Krasnodar, Russia
| | - Ksenia Solonchenko
- Russian Federation, Kuban State University, 149, Stavropolskaya Str., 350040 Krasnodar, Russia
| | - Evgeniia Pasechnaya
- Russian Federation, Kuban State University, 149, Stavropolskaya Str., 350040 Krasnodar, Russia
| | - Veronika Sarapulova
- Russian Federation, Kuban State University, 149, Stavropolskaya Str., 350040 Krasnodar, Russia
| | - Yaoming Wang
- Anhui Provincial Engineering Laboratory of Functional Membrane Science and Technology, Department of Applied Chemistry, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230026, China
| | - Chenxiao Jiang
- Anhui Provincial Engineering Laboratory of Functional Membrane Science and Technology, Department of Applied Chemistry, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230026, China
| | - Tongwen Xu
- Anhui Provincial Engineering Laboratory of Functional Membrane Science and Technology, Department of Applied Chemistry, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230026, China
| | - Victor Nikonenko
- Russian Federation, Kuban State University, 149, Stavropolskaya Str., 350040 Krasnodar, Russia
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Solonchenko K, Kirichenko A, Kirichenko K. Stability of Ion Exchange Membranes in Electrodialysis. MEMBRANES 2022; 13:52. [PMID: 36676859 PMCID: PMC9866250 DOI: 10.3390/membranes13010052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 12/26/2022] [Accepted: 12/29/2022] [Indexed: 06/17/2023]
Abstract
During electrodialysis the ion exchange membranes are affected by such factors as passage of electric current, heating, tangential flow of solution and exposure to chemical agents. It can potentially cause the degradation of ion exchange groups and of polymeric backbone, worsening the performance of the process and necessitating the replacement of the membranes. This article aims to review how the composition and the structure of ion exchange membranes change during the electrodialysis or the studies imitating it.
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Affiliation(s)
- Ksenia Solonchenko
- Physical Chemistry Department, Faculty of Chemistry and High Technologies, Kuban State University, 149 Stavropolskaya St., 350040 Krasnodar, Russia
| | - Anna Kirichenko
- Department of Electric Engineering, Thermotechnics, Renewable Energy Sources, Faculty of Energetics, Kuban State Agrarian University named after I.T. Trubilin, 13 Kalinina St., 350004 Krasnodar, Russia
| | - Ksenia Kirichenko
- Physical Chemistry Department, Faculty of Chemistry and High Technologies, Kuban State University, 149 Stavropolskaya St., 350040 Krasnodar, Russia
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Nir O, Oren Y, Musie, Atshba W, Chandra A, Geller Y, Chaudhary M, Monat L, Singh P, Zevenhoven R. Reactive transport in membrane separation modeling: a perspective. Chem Eng Res Des 2022. [DOI: 10.1016/j.cherd.2022.09.054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Recovery of Nutrients from Residual Streams Using Ion-Exchange Membranes: Current State, Bottlenecks, Fundamentals and Innovations. MEMBRANES 2022; 12:membranes12050497. [PMID: 35629823 PMCID: PMC9145069 DOI: 10.3390/membranes12050497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 04/28/2022] [Accepted: 05/01/2022] [Indexed: 11/23/2022]
Abstract
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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Two mechanisms of H+/OH− ion generation in anion-exchange membrane systems with polybasic acid salt solutions. J Memb Sci 2022. [DOI: 10.1016/j.memsci.2022.120449] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Rybalkina OA, Moroz IA, Gorobchenko AD, Pismenskaya ND, Nikonenko VV. Development of Electroconvection at the Undulate Surface of an Anion-Exchange Membrane in Sodium Chloride and Sodium Hydrogen Tartrate Solutions. MEMBRANES AND MEMBRANE TECHNOLOGIES 2022. [DOI: 10.1134/s2517751622010061] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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9
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A critical analysis on ion transport of organic acid mixture through an anion-exchange membrane during electrodialysis. Chem Eng Res Des 2022. [DOI: 10.1016/j.cherd.2021.11.035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Pismenskaya N, Rybalkina O, Moroz I, Mareev S, Nikonenko V. Influence of Electroconvection on Chronopotentiograms of an Anion-Exchange Membrane in Solutions of Weak Polybasic Acid Salts. Int J Mol Sci 2021; 22:ijms222413518. [PMID: 34948329 PMCID: PMC8708104 DOI: 10.3390/ijms222413518] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 12/10/2021] [Accepted: 12/13/2021] [Indexed: 12/25/2022] Open
Abstract
Visualization of electroconvective (EC) vortices at the undulated surface of an AMX anion-exchange membrane (Astom, Osaka, Japan) was carried out in parallel with the measurement of chronopotentiograms. Weak polybasic acid salts, including 0.02 M solutions of tartaric (NaHT), phosphoric (NaH2PO4), and citric (NaH2Cit) acids salts, and NaCl were investigated. It was shown that, for a given current density normalized to the theoretical limiting current calculated by the Leveque equation (i/ilimtheor), EC vortex zone thickness, dEC, decreases in the order NaCl > NaHT > NaH2PO4 > NaH2Cit. This order is inverse to the increase in the intensity of proton generation in the membrane systems under study. The higher the intensity of proton generation, the lower the electroconvection. This is due to the fact that protons released into the depleted solution reduce the space charge density, which is the driver of EC. In all studied systems, a region in chronopotentiograms between the rapid growth of the potential drop and the attainment of its stationary values corresponds to the appearance of EC vortex clusters. The amplitude of the potential drop oscillations in the chronopotentiograms is proportional to the size of the observed vortex clusters.
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Polezhaev P, Belloň T, Vobecká L, Slouka Z. Molecular sieving of alkyl sulfate anions on strong basic gel-type anion-exchange resins. Sep Purif Technol 2021. [DOI: 10.1016/j.seppur.2021.119382] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Pismenskaya N, Bdiri M, Sarapulova V, Kozmai A, Fouilloux J, Baklouti L, Larchet C, Renard E, Dammak L. A Review on Ion-Exchange Membranes Fouling during Electrodialysis Process in Food Industry, Part 2: Influence on Transport Properties and Electrochemical Characteristics, Cleaning and Its Consequences. MEMBRANES 2021; 11:membranes11110811. [PMID: 34832040 PMCID: PMC8623251 DOI: 10.3390/membranes11110811] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 10/19/2021] [Accepted: 10/19/2021] [Indexed: 12/17/2022]
Abstract
Ion-exchange membranes (IEMs) are increasingly used in dialysis and electrodialysis processes for the extraction, fractionation and concentration of valuable components, as well as reagent-free control of liquid media pH in the food industry. Fouling of IEMs is specific compared to that observed in the case of reverse or direct osmosis, ultrafiltration, microfiltration, and other membrane processes. This specificity is determined by the high concentration of fixed groups in IEMs, as well as by the phenomena inherent only in electromembrane processes, i.e., induced by an electric field. This review analyzes modern scientific publications on the effect of foulants (mainly typical for the dairy, wine and fruit juice industries) on the structural, transport, mass transfer, and electrochemical characteristics of cation-exchange and anion-exchange membranes. The relationship between the nature of the foulant and the structure, physicochemical, transport properties and behavior of ion-exchange membranes in an electric field is analyzed using experimental data (ion exchange capacity, water content, conductivity, diffusion permeability, limiting current density, water splitting, electroconvection, etc.) and modern mathematical models. The implications of traditional chemical cleaning are taken into account in this analysis and modern non-destructive membrane cleaning methods are discussed. Finally, challenges for the near future were identified.
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Affiliation(s)
- Natalia Pismenskaya
- Department of Physical Chemistry, Kuban State University, 149 Stavropolskaya Str., 350040 Krasnodar, Russia; (N.P.); (V.S.); (A.K.)
| | - Myriam Bdiri
- Institut de Chimie et des Matériaux Paris-Est (ICMPE), Université Paris-Est Créteil, CNRS, ICMPE, UMR 7182, 2 Rue Henri Dunant, 94320 Thiais, France; (M.B.); (J.F.); (C.L.); (E.R.)
| | - Veronika Sarapulova
- Department of Physical Chemistry, Kuban State University, 149 Stavropolskaya Str., 350040 Krasnodar, Russia; (N.P.); (V.S.); (A.K.)
| | - Anton Kozmai
- Department of Physical Chemistry, Kuban State University, 149 Stavropolskaya Str., 350040 Krasnodar, Russia; (N.P.); (V.S.); (A.K.)
| | - Julie Fouilloux
- Institut de Chimie et des Matériaux Paris-Est (ICMPE), Université Paris-Est Créteil, CNRS, ICMPE, UMR 7182, 2 Rue Henri Dunant, 94320 Thiais, France; (M.B.); (J.F.); (C.L.); (E.R.)
| | - Lassaad Baklouti
- Department of Chemistry, College of Sciences and Arts at Al Rass, Qassim University, Ar Rass 51921, Saudi Arabia;
| | - Christian Larchet
- Institut de Chimie et des Matériaux Paris-Est (ICMPE), Université Paris-Est Créteil, CNRS, ICMPE, UMR 7182, 2 Rue Henri Dunant, 94320 Thiais, France; (M.B.); (J.F.); (C.L.); (E.R.)
| | - Estelle Renard
- Institut de Chimie et des Matériaux Paris-Est (ICMPE), Université Paris-Est Créteil, CNRS, ICMPE, UMR 7182, 2 Rue Henri Dunant, 94320 Thiais, France; (M.B.); (J.F.); (C.L.); (E.R.)
| | - Lasâad Dammak
- Institut de Chimie et des Matériaux Paris-Est (ICMPE), Université Paris-Est Créteil, CNRS, ICMPE, UMR 7182, 2 Rue Henri Dunant, 94320 Thiais, France; (M.B.); (J.F.); (C.L.); (E.R.)
- Correspondence: ; Tel.: +33-145171786
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Rybalkina OA, Solonchenko KV, Nikonenko VV, Pismenskaya ND. Investigation of Causes of Low Current Efficiency in Electrodialysis of Phosphate-Containing Solutions. MEMBRANES AND MEMBRANE TECHNOLOGIES 2021. [DOI: 10.1134/s2517751621040065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Investigation of ion-exchange membranes by means of chronopotentiometry: A comprehensive review on this highly informative and multipurpose technique. Adv Colloid Interface Sci 2021; 293:102439. [PMID: 34058435 DOI: 10.1016/j.cis.2021.102439] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 05/06/2021] [Accepted: 05/07/2021] [Indexed: 11/21/2022]
Abstract
Electrodialysis is mostly used for drinking water production but it has gained applicability in different new fields in recent decades. Membrane characteristics and ion transport properties strongly influence the efficiency of electrodialysis and must be evaluated to avoid an intense energy consumption and ensure long membrane times of usage. To this aim, conducting studies on ion transport across membranes is essential. Several dynamic characterization methods can be employed, among which, chronopotentiometry has shown special relevance because it allows a direct access to the contribution of the potential in different states of the membrane/solution system. The present paper provides a critical review on the use of chronopotentiometry to determine the main membrane transport properties and to evaluate mass transfer phenomena. Properties, such as limiting current density, electrical resistances, plateau length, transport number of counter-ions in the membrane, transition times, and apparent fraction of membrane conductive area have been intensively discussed in the literature and are presented in this review. Some of the phenomena evaluated using this technique are concentration polarization, gravitational convection, electroconvection, water dissociation, and fouling/scaling, all of them also shown herein. Mathematical and experimental studies were considered. New trends in chronopotentiometric studies should include ion-exchange membranes that have been recently developed (presenting anti-fouling, anti-microbial, and monovalent-selective properties) and a deeper discussion on the behaviour of complex solutions that have been often treated by electrodialysis, such as municipal wastewaters. New mathematical models, especially 3D ones, are also expected to be developed in the coming years.
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Barros KS, Martí-Calatayud MC, Ortega EM, Pérez-Herranz V, Espinosa DCR. Chronopotentiometric study on the simultaneous transport of EDTA ionic species and hydroxyl ions through an anion-exchange membrane for electrodialysis applications. J Electroanal Chem (Lausanne) 2020. [DOI: 10.1016/j.jelechem.2020.114782] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Water Splitting and Transport of Ions in Electromembrane System with Bilayer Ion-Exchange Membrane. MEMBRANES 2020; 10:membranes10110346. [PMID: 33207651 PMCID: PMC7697576 DOI: 10.3390/membranes10110346] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 11/10/2020] [Accepted: 11/10/2020] [Indexed: 12/03/2022]
Abstract
Bilayer ion-exchange membranes are mainly used for separating single and multiply charged ions. It is well known that in membranes in which the layers have different charges of the ionogenic groups of the matrix, the limiting current decreases, and the water splitting reaction accelerates in comparison with monolayer (isotropic) ion-exchange membranes. We study samples of bilayer ion-exchange membranes with very thin cation-exchange layers deposited on an anion-exchange membrane-substrate in this work. It was revealed that in bilayer membranes, the limiting current’s value is determined by the properties of a thin surface film (modifying layer). A linear regularity of the dependence of the non-equilibrium effective rate constant of the water-splitting reaction on the resistance of the bipolar region, which is valid for both bilayer and bipolar membranes, has been revealed. It is shown that the introduction of the catalyst significantly reduces the water-splitting voltage, but reduces the selectivity of the membrane. It is possible to regulate the fluxes of salt ions and water splitting products (hydrogen and hydroxyl ions) by changing the current density. Such an ability makes it possible to conduct a controlled process of desalting electrolytes with simultaneous pH adjustment.
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