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Mechanistic Modeling of Transport in Nanofiltration

Membrane Separation and Transport

  1. Anthony Szymczyk

Published Online: 27 SEP 2013

DOI: 10.1002/9781118522318.emst147

Encyclopedia of Membrane Science and Technology

Encyclopedia of Membrane Science and Technology

How to Cite

Szymczyk, A. 2013. Mechanistic Modeling of Transport in Nanofiltration. Encyclopedia of Membrane Science and Technology. 1–29.

Author Information

  1. Université de Rennes 1, Rennes Cedex, France

Publication History

  1. Published Online: 27 SEP 2013

Abstract

This article discusses macroscopic modeling of the transport mechanisms of ions through nanofiltration membranes. The modeling is based on mechanistic approaches that consider nanofiltration membranes as bundles of (nano)pores and ionic transport as resulting from hindered diffusion, electromigration, and convection. The governing equations are presented and the main assumptions and approximations are reviewed and discussed. Special attention is given to the uniform potential approximation (also called homogeneous approximation), which forms the basis of most current transport models used in nanofiltration. The impact of steric hindrance, membrane fixed charge density, and salt concentration on the rejection of single-salt solutions and electrolyte mixtures is illustrated through a series of examples. Some recent advances in nanofiltration modeling (introduction into transport models of the dielectric exclusion phenomena and spatial inhomogeneities of the fixed charge) are also briefly discussed.

Keywords:

  • nanofiltration;
  • transport phenomena;
  • modeling;
  • charged membranes;
  • transport theory