English

Deionization Shock Driven by Electroconvection in a Circular Channel

Fluid Dynamics 2020-08-25 v2

Abstract

In a circular channel passing over-limiting current (faster than diffusion), transient vortices of bulk electroconvection are observed in salt-depleted region within the horizontal plane. The spatiotemporal evolution of the salt concentration is directly visualized, revealing the propagation of a deionization shock wave driven by bulk electroconvection up to millimeter scales. This novel mechanism leads to quantitatively similar dynamics as for deionization shocks in charged porous media, which are driven instead by surface conduction and electro-osmotic flow at micron to nanometer scales. The remarkable generality of deionization shocks under over-limiting current could be used to manipulate ion transport in complex geometries for desalination and water treatment.

Keywords

Cite

@article{arxiv.1901.10648,
  title  = {Deionization Shock Driven by Electroconvection in a Circular Channel},
  author = {Zhibo Gu and Bingrui Xu and Peng Huo and Shmuel M. Rubinstein and Martin Z. Bazant and Daosheng Deng},
  journal= {arXiv preprint arXiv:1901.10648},
  year   = {2020}
}

Comments

5 pages, 4 figures

R2 v1 2026-06-23T07:26:33.992Z