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Merging Ion Concentration Polarization between Juxtaposed Ion Exchange Membranes to Block the Propagation of the Polarization Zone
Published on: February 23, 2017
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Novel ionic separation mechanisms in electrically driven membrane processes
I G Wenten1, K Khoiruddin1, Mohammad A Alkhadra2
1Department of Chemical Engineering, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132, Indonesia; Research Center for Nanosciences and Nanotechnology, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132, Indonesia.
Advances in Colloid and Interface Science
|September 22, 2020
Summary
Electromembrane processes like electrodialysis (ED) are limited by ion diffusion. Novel mechanisms, including deionization shock waves, enable overlimiting current (OLC) for enhanced ion transport and process efficiency.
Area of Science:
- Electrochemistry
- Chemical Engineering
- Materials Science
Background:
- Electromembrane processes, such as electrodialysis (ED), are often constrained by diffusion-limited current (DLC).
- Operating beyond DLC (overlimiting current, OLC) is challenging due to ion depletion at membrane surfaces, leading to inefficiencies and scaling.
- Novel ion transport mechanisms offer potential solutions for enhancing mass transfer in ED and related processes.
Purpose of the Study:
- To review emerging ion transport mechanisms that facilitate overlimiting current (OLC) operation in electromembrane systems.
- To explore the role of these novel mechanisms in enhancing ion transfer and improving process efficiency.
- To contextualize these findings within advanced electromembrane applications like shock electrodialysis (shock ED) and electrodeionization (EDI).
Main Methods:
- Literature review of scientific studies on ion transport phenomena in electromembrane systems.
- Analysis of exotic ion transport mechanisms, including ion concentration polarization in micro/nanofluidics, deionization shock waves, and ionic bridges.
- Examination of the application of these mechanisms in overlimiting current (OLC) operation.
Main Results:
- Overlimiting current (OLC) can be achieved through non-conventional ion transport mechanisms beyond simple diffusion.
- Exotic mechanisms like deionization shock waves and ionic bridges significantly enhance ion transfer rates.
- These mechanisms are crucial for the advancement of processes such as shock ED and electrodeionization (EDI).
Conclusions:
- Novel electrokinetic phenomena provide viable pathways to overcome diffusion limitations in electromembrane processes.
- Understanding and harnessing these mechanisms are key to developing more efficient and effective ion separation technologies.
- The reviewed mechanisms hold significant promise for the future of electromembrane applications, including water treatment and desalination.
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