scholarly journals Effect of Surface Inhomogeneity of Ion-Exchange Membranes on the Mass Transfer Efficiency in Pulsed Electric Field Modes

Membranes ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 40 ◽  
Author(s):  
Dmitrii Butylskii ◽  
Ilya Moroz ◽  
Kseniya Tsygurina ◽  
Semyon Mareev
Keyword(s):  
Mass Transfer ◽  
Ion Exchange ◽  
Electric Field ◽  
Membrane Separation ◽  
Rapid Development ◽  
Concentration Field ◽  
Pulsed Electric Field ◽  
Limiting Current ◽  
Ion Exchange Membranes ◽  
Low Frequencies

Despite the growing interest in pulsed electric field modes in membrane separation processes, there are currently not many works devoted to studying the effect of the surface properties and composition of ion-exchange membranes on their efficiency in these modes. In this paper, we have shown the effect of increasing mass transfer using different kinds of ion-exchange membranes (heterogeneous and homogeneous with smooth, undulated, and rough surfaces) during electrodialysis in the pulsed electric field modes at underlimiting and overlimiting currents. It was found that the maximum increment in the average current is achieved when the average potential corresponds to the right-hand edge of the limiting current plateau of the voltammetric curve, i.e., at the maximum resistance of the system in the DC mode. For the first time, the development of electroconvective vortices was visualized in pulsed electric field modes and it was experimentally shown that even at relatively low frequencies, a non-uniform concentration field is preserved at the time of a pause, which stimulates the rapid development of electroconvection when pulses are switched on again. In the case of relatively high pulse frequencies, the electroconvective vortices formed during a pulse lapse do not completely decay during a pause; they only slightly decrease in size.

scholarly journals 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 ◽  
Vol 11 (11) ◽  
pp. 811
Author(s):  
Natalia Pismenskaya ◽  
Myriam Bdiri ◽  
Veronika Sarapulova ◽  
Anton Kozmai ◽  
Julie Fouilloux ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Electric Field ◽  
Transport Properties ◽  
Food Industry ◽  
Limiting Current ◽  
Electrochemical Characteristics ◽  
Anion Exchange Membranes ◽  
Ion Exchange Membranes ◽  
High Concentration ◽  
Scientific Publications

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.

scholarly journals Evaluation of Electrodialysis Desalination Performance of Novel Bioinspired and Conventional Ion Exchange Membranes with Sodium Chloride Feed Solutions

Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 217
Author(s):  
AHM Golam Hyder ◽  
Brian A. Morales ◽  
Malynda A. Cappelle ◽  
Stephen J. Percival ◽  
Leo J. Small ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Cation Exchange ◽  
Current Density ◽  
Feed Solution ◽  
Laboratory Scale ◽  
Cation Exchange Membrane ◽  
Limiting Current ◽  
Ion Exchange Membranes ◽  
Experimental Apparatus ◽  
Exchange Membrane

Electrodialysis (ED) desalination performance of different conventional and laboratory-scale ion exchange membranes (IEMs) has been evaluated by many researchers, but most of these studies used their own sets of experimental parameters such as feed solution compositions and concentrations, superficial velocities of the process streams (diluate, concentrate, and electrode rinse), applied electrical voltages, and types of IEMs. Thus, direct comparison of ED desalination performance of different IEMs is virtually impossible. While the use of different conventional IEMs in ED has been reported, the use of bioinspired ion exchange membrane has not been reported yet. The goal of this study was to evaluate the ED desalination performance differences between novel laboratory‑scale bioinspired IEM and conventional IEMs by determining (i) limiting current density, (ii) current density, (iii) current efficiency, (iv) salinity reduction in diluate stream, (v) normalized specific energy consumption, and (vi) water flux by osmosis as a function of (a) initial concentration of NaCl feed solution (diluate and concentrate streams), (b) superficial velocity of feed solution, and (c) applied stack voltage per cell-pair of membranes. A laboratory‑scale single stage batch-recycle electrodialysis experimental apparatus was assembled with five cell‑pairs of IEMs with an active cross-sectional area of 7.84 cm2. In this study, seven combinations of IEMs (commercial and laboratory-made) were compared: (i) Neosepta AMX/CMX, (ii) PCA PCSA/PCSK, (iii) Fujifilm Type 1 AEM/CEM, (iv) SUEZ AR204SZRA/CR67HMR, (v) Ralex AMH-PES/CMH-PES, (vi) Neosepta AMX/Bare Polycarbonate membrane (Polycarb), and (vii) Neosepta AMX/Sandia novel bioinspired cation exchange membrane (SandiaCEM). ED desalination performance with the Sandia novel bioinspired cation exchange membrane (SandiaCEM) was found to be competitive with commercial Neosepta CMX cation exchange membrane.

scholarly journals Water Splitting and Transport of Ions in Electromembrane System with Bilayer Ion-Exchange Membrane

Membranes ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 346 ◽  
Author(s):  
Stanislav Melnikov ◽  
Denis Bondarev ◽  
Elena Nosova ◽  
Ekaterina Melnikova ◽  
Victor Zabolotskiy
Keyword(s):  
Ion Exchange ◽  
Water Splitting ◽  
Surface Film ◽  
Effective Rate Constant ◽  
Effective Rate ◽  
Limiting Current ◽  
Ion Exchange Membranes ◽  
Bipolar Membranes ◽  
The Matrix ◽  
Exchange Membrane

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.

scholarly journals Study of Chromium Removal by the Electrodialysis of Tannery and Metal-Finishing Effluents

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Ruan C. A. Moura ◽  
Daniel A. Bertuol ◽  
Carlos A. Ferreira ◽  
Franco D. R. Amado
Keyword(s):  
Wastewater Treatment ◽  
Ion Exchange ◽  
Electric Field ◽  
Driving Force ◽  
Membrane Separation ◽  
Physicochemical Process ◽  
Separation Technique ◽  
Chromium Removal ◽  
Metal Finishing ◽  
Interesting Alternative

The metal-finishing and tannery industries have been under strong pressure to replace their current wastewater treatment based on a physicochemical process. The electrodialysis process is becoming an interesting alternative for wastewater treatment. Electrodialysis is a membrane separation technique, in which ions are transported from one solution to another through ion-exchange membranes, using an electric field as the driving force. Blends of polystyrene and polyaniline were obtained in order to produce membranes for electrodialysis. The produced membranes were applied in the recovery of baths from the metal-finishing and tannery industries. The parameter for electrodialysis evaluation was the percentage of chromium extraction. The results obtained using these membranes were compared to those obtained with the commercial membrane Nafion 450.

Effect of pulsed electric field on electrodialysis of a NaCl solution in sub-limiting current regime

2015 ◽  
Vol 164 ◽  
pp. 267-280 ◽  
Author(s):  
P. Sistat ◽  
P. Huguet ◽  
B. Ruiz ◽  
G. Pourcelly ◽  
S.A. Mareev ◽  
...  
Keyword(s):  
Electric Field ◽  
Pulsed Electric Field ◽  
Limiting Current ◽  
Nacl Solution ◽  
Current Regime

Additions and Corrections - Solvent Mass Transfer across Ion-Exchange Membranes

1968 ◽  
Vol 90 (16) ◽  
pp. 4515-4515
Author(s):  
A. S. Tombalkian ◽  
M. Worsley ◽  
W. F. Graydon
Keyword(s):  
Mass Transfer ◽  
Ion Exchange ◽  
Ion Exchange Membranes
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