Staff Publications

  • external user (warningwarning)
  • Log in as
  • language uk
Record number 503315
Title On-line method to study dynamics of ion adsorption from mixtures of salts in capacitive deionization
Author(s) Dykstra, J.E.; Dijkstra, J.; Wal, A. van der; Hamelers, H.V.M.; Porada, S.
Source Desalination 390 (2016). - ISSN 0011-9164 - p. 47 - 52.
DOI https://doi.org/10.1016/j.desal.2016.04.001
Department(s) Sub-department of Environmental Technology
WU Plant SciencesDepartment of Plant Sciences
Publication type Refereed Article in a scientific journal
Publication year 2016
Keyword(s) Capacitive Deionization - Electrosorption - Ionic mixtures - Salt removal - Selective ion removal
Abstract

Capacitive Deionization (CDI) is a water desalination technology that adsorbs ions into two oppositely polarized porous carbon electrodes, under the action of an applied voltage. Here, we introduce a novel method to analyze the effluent concentration of multiple ionic species in mixtures of salt solutions by directing the outflow of a CDI cell to an inductively coupled plasma optical emission spectroscopy (ICP-OES) instrument. Compared to previous methods based on manual sampling, the on-line use of ICP-OES allows collecting more accurate time-dependent ion adsorption data, and therefore, ion dynamics can be studied even at very short half-cycle times. We use this method to study ion adsorption from a mixed solution containing two monovalent cations with similar radius, namely potassium and sodium. We find that potassium ions are preferentially adsorbed over sodium ions, due to their higher mobility. Furthermore, we compare our experimental findings with a novel multicomponent electromigration model that calculates dynamic adsorption of ions from solutions of multiple salts. Whereas we find good agreement between data and theory at low half cycle times, we observe a considerable discrepancy at higher values.

Comments
There are no comments yet. You can post the first one!
Post a comment
 
Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.