Theoretical Analysis of the Effect of Ion Concentration in Solution Bulk and at Membrane Surface on the Mass Transfer at Overlimiting Currents
- 作者: Uzdenova A.1, Kovalenko A.2, Urtenov M.2, Nikonenko V.2
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隶属关系:
- Karachaevo-Cherkessky State University Named after U.D. Aliev
- Kuban State University
- 期: 卷 53, 编号 11 (2017)
- 页面: 1254-1265
- 栏目: Article
- URL: https://journals.rcsi.science/1023-1935/article/view/189121
- DOI: https://doi.org/10.1134/S1023193517110179
- ID: 189121
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详细
Overlimiting current modes are of considerable interest for the practice of electrodialysis (ED). However, the economical expedience of such ED modes is evident only for desalination of dilute solutions. Here, we show the theoretical analysis of the effect of concentration on the behavior of an ED cell with homogeneous ion-exchange membranes. The study is based on numerical solution of the two-dimensional system of coupled equations of Nernst–Planck–Poisson–Navier–Stokes. It is shown that as the electrolyte concentration in solution that enters the ED desalination chamber increases, the intensity of electroconvection decreases, which induces a decrease in the relative mass-transfer rate (the decrease in the ratio of current density to its limiting value). This effect is stronger in the region of high potential differences where the electroconvective instability of Rubinstein–Zaltzman is realized under the conditions of a nonuniform concentration field caused by solution desalination. In contrast, the increase in the counterion concentration at the membrane surface (associated with the increase in the surface charge) intensifies the electroconvection.
作者简介
A. Uzdenova
Karachaevo-Cherkessky State University Named after U.D. Aliev
编辑信件的主要联系方式.
Email: uzd_am@mail.ru
俄罗斯联邦, Karachaevsk, 369202
A. Kovalenko
Kuban State University
Email: uzd_am@mail.ru
俄罗斯联邦, Krasnodar, 350040
M. Urtenov
Kuban State University
Email: uzd_am@mail.ru
俄罗斯联邦, Krasnodar, 350040
V. Nikonenko
Kuban State University
Email: uzd_am@mail.ru
俄罗斯联邦, Krasnodar, 350040