Theory of shock electrodialysis II: Mechanisms of selective ion removal
| Autor: | Martin Z. Bazant, Mohammad A. Alkhadra, Huanhuan Tian |
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| Rok vydání: | 2021 |
| Předmět: |
Work (thermodynamics)
Materials science 02 engineering and technology Electrolyte Electrodialysis 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Streaming current 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Ion Shock (mechanics) Biomaterials Electrokinetic phenomena Colloid and Surface Chemistry Chemical physics Water treatment 0210 nano-technology |
| Zdroj: | Journal of Colloid and Interface Science. 589:616-621 |
| ISSN: | 0021-9797 |
| DOI: | 10.1016/j.jcis.2020.11.127 |
| Popis: | Shock electrodialysis (shock ED), an emerging nonlinear electrokinetic process for water treatment, has recently showed its capability to selectively remove multivalent cations from electrolyte mixtures. However, the mechanisms have not been understood yet. Based on the depth-averaged model developed in the first-part of the series paper for planer shock ED system, this work focuses on the mechanisms of selective ion removal. We first assume plug feed flow and do scaling analysis, and identify three possible mechanisms of selective removal of multivalent cations: smaller concentration left behind deionization zone, affinity to the charged surface where non-slip boundary slows down the velocity, and stronger push-back by streaming potential. Then we use numerical simulations to prove our hypothesis and show additional contribution from electroosmotic flow. Simulation results show that Mg is more removed from Na-Mg-Cl mixture at overlimiting current, which is qualitatively consistent with experiment results in literature. |
| Databáze: | OpenAIRE |
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