Overlimiting mechanisms of heterogeneous cation- and anion-exchange membranes: A side-by-side comparison

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22340%2F24%3A43931356" target="_blank" >RIV/60461373:22340/24:43931356 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/49777513:23640/24:43970893

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0011916423007257?via%3Dihub" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0011916423007257?via%3Dihub</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.desal.2023.117093" target="_blank" >10.1016/j.desal.2023.117093</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Overlimiting mechanisms of heterogeneous cation- and anion-exchange membranes: A side-by-side comparison

Popis výsledku v původním jazyce

Overlimiting ionic transfer attainable at ion-exchange membranes is a potential way to intensify electromembrane separation processes, such as electrodialysis. The primary mechanisms responsible for overlimiting current are electroconvection, natural convection, and water splitting. For the first time, the present study experimentally investigates all three mechanisms on heterogeneous anion- and cation-exchange membranes, using direct membrane observation and indirect measurement of pH changes in 0.01 M KCl solution. Although the anion- and cation-exchange systems are designed to exhibit the same behavior with different counterions, our results indicate significant differences in the overlimiting ionic transfer. The strong polarization of cationexchange membranes produced an intensive electroconvective vortex with characteristic velocities in hundreds of mu m/s superimposed by an upward electrolyte motion caused by natural convection. No pH changes associated with the water-splitting reaction were observed. The same conditions applied to the anion-exchange membrane resulted in profound pH changes, weaker electroconvection, and natural convection, reaching similar characteristic velocities to the other studied system. Generally, anion-exchange systems were characterized by more significant fluctuations in measured characteristics and were susceptible to fouling by one of the negatively charged markers. The obtained data provide a unified description of phenomena that may occur in the elec-trodialysis of low-concentrated ionic solutions.

Název v anglickém jazyce

Overlimiting mechanisms of heterogeneous cation- and anion-exchange membranes: A side-by-side comparison

Popis výsledku anglicky

Overlimiting ionic transfer attainable at ion-exchange membranes is a potential way to intensify electromembrane separation processes, such as electrodialysis. The primary mechanisms responsible for overlimiting current are electroconvection, natural convection, and water splitting. For the first time, the present study experimentally investigates all three mechanisms on heterogeneous anion- and cation-exchange membranes, using direct membrane observation and indirect measurement of pH changes in 0.01 M KCl solution. Although the anion- and cation-exchange systems are designed to exhibit the same behavior with different counterions, our results indicate significant differences in the overlimiting ionic transfer. The strong polarization of cationexchange membranes produced an intensive electroconvective vortex with characteristic velocities in hundreds of mu m/s superimposed by an upward electrolyte motion caused by natural convection. No pH changes associated with the water-splitting reaction were observed. The same conditions applied to the anion-exchange membrane resulted in profound pH changes, weaker electroconvection, and natural convection, reaching similar characteristic velocities to the other studied system. Generally, anion-exchange systems were characterized by more significant fluctuations in measured characteristics and were susceptible to fouling by one of the negatively charged markers. The obtained data provide a unified description of phenomena that may occur in the elec-trodialysis of low-concentrated ionic solutions.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20401 - Chemical engineering (plants, products)

Projekt

<a href="/cs/project/GA20-21263S" target="_blank" >GA20-21263S: Analýza elektrodialýzy v milifluidních průtočných systémech</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2024

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

DESALINATION

ISSN

0011-9164

e-ISSN

1873-4464

Svazek periodika

571

Číslo periodika v rámci svazku

117093

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

12

Strana od-do

—

Kód UT WoS článku

001104562300001

EID výsledku v databázi Scopus

2-s2.0-85175343114