Experimental 3D concentration profiles along an electrodialysis channel reveal a strong effect of natural convection

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22340%2F23%3A43926888" target="_blank" >RIV/60461373:22340/23:43926888 - isvavai.cz</a>

Alternative codes found

RIV/60461373:22810/23:43926888 RIV/49777513:23640/23:43968952

Result on the web

<a href="http://dx.doi.org/10.1016/j.desal.2022.116302" target="_blank" >http://dx.doi.org/10.1016/j.desal.2022.116302</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.desal.2022.116302" target="_blank" >10.1016/j.desal.2022.116302</a>

Result language

angličtina

Original language name

Experimental 3D concentration profiles along an electrodialysis channel reveal a strong effect of natural convection

Original language description

Electrodialysis and electrodeionization separate ionic components from processed water solutions by applying a DC electric field on a stack of ion-exchange membranes. The ion separation indicates ionic concentration changes along the channels in the membrane modules. Simultaneously, concentration polarization at the ion-exchange membranes causes ionic concentration variations across the channels. We constructed a milifluidic cell with a diluate channel to measure spatial concentration profiles under single-path electrodialysis conditions. Desalination of 0.1 M NaCl solution showed that the concentration decreases linearly along the channel when connecting relatively low average current densities (&lt; 30 A/m2), yielding &lt;70 % desalination. Higher average current densities causing desalination close to 100 % produced nonlinear concentration profiles characterized by a steep linear drop followed by an almost constant and small concentration region. We show that at a current density of 50 A/m2, only one-third of the diluate channel is employed for desalination. Interestingly, uniform concentration profiles developed across the channels even at high polarization current densities. Unlike constant concentrations across the channel, we found substantial concentration variation in the vertical direction of the channel, indicating the effect of density gradients and natural convection. This effect was confirmed by optical microscopy and particle image velocimetry of this convection in stagnant solution layers. Natural convection, thus, can represent a mechanism intensifying the mass transfer from the solution bulk to the membrane surfaces. © 2022

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

20402 - Chemical process engineering

Project

<a href="/en/project/GA20-21263S" target="_blank" >GA20-21263S: Analysis of electrodialysis in milifluidic flow-through systems</a><br>

Continuities

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

Publication year

2023

Confidentiality

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

Name of the periodical

Desalination

ISSN

0011-9164

e-ISSN

—

Volume of the periodical

548

Issue of the periodical within the volume

548

Country of publishing house

NL - THE KINGDOM OF THE NETHERLANDS

Number of pages

10

Pages from-to

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UT code for WoS article

000904568000003

EID of the result in the Scopus database

2-s2.0-85143793308