A Usable Kinetic Model of Suspended Ion Exchange Processes for Natural Organic Matter Removal

Shaoying S. Qi, Treavor H. Boyer, Yue Hu

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


The suspended ion exchange (SIEX) process is an emerging technology for the removal of dissolved natural organic matter (NOM). To facilitate the SIEX selection, design, and operation, a usable mechanistic model is proposed. The simple kinetic model unifies the Lagergren equation and the Glueckauf model and has analytical solutions for common SIEX processes. It is shown, through comparison with experimental data, that the proposed model describes SIEX effectively. The plug-flow and the mixed-flow processes, such as SIX and MIEX, treat the removable NOM well. At (removable NOM) removal efficiency above 50%, though, both SIEX processes increasingly run into poor resin capacity utilization due to the process thermodynamic constraint and, to a lesser extent, the kinetic effect. The choice of chloride-form or bicarbonate-form resin has little effect on the adsorption distribution constant of removable NOM. Replacing chloride with bicarbonate as the counterion, however, increases the nonremovable NOM fraction, i.e., causes an additional amount of NOM unable to access the adsorption sites. The result of counterion binding suggests that the nonremovable NOM fraction is just a mixture of the NOM compounds that have insufficient affinity to displace resin counterion from adsorption sites and raises question on the hypothesis in the literature that attributes the nonremovable NOM to the uncharged NOM species only.

Original languageEnglish (US)
Article number04021068
JournalJournal of Environmental Engineering (United States)
Issue number12
StatePublished - Dec 1 2021


  • Mathematical model
  • Natural organic matter (NOM)
  • Suspended ion exchange (SIEX)
  • Water treatment

ASJC Scopus subject areas

  • General Environmental Science
  • Environmental Engineering
  • Environmental Chemistry
  • Civil and Structural Engineering


Dive into the research topics of 'A Usable Kinetic Model of Suspended Ion Exchange Processes for Natural Organic Matter Removal'. Together they form a unique fingerprint.

Cite this