1. Home
  2. Environment - Safety
  3. Water technologies

  4. Membrane filtration (RO, NF, UF) - Membranes and modules presentation

Article | REF: W4090 V1

Membrane filtration (RO, NF, UF) - Membranes and modules presentation

Authors: Jean-Christophe REMIGY, Sandrine DESCLAUX

Publication date: March 10, 2007

You do not have access to this resource.
Click here to request your free trial access!

Already subscribed? Log in!

Overview

Français

Read this article from a comprehensive knowledge base, updated and supplemented with articles reviewed by scientific committees.

Read the article

AUTHORS

  • Jean-Christophe REMIGY: Senior Lecturer - ENSIC engineer - Chemical Engineering Laboratory (CNRS-UMR 5503) - Paul-Sabatier University (Toulouse III)

  • Sandrine DESCLAUX: Design engineer - Chemical Engineering Laboratory (CNRS – UMR 5503) - Université Paul-Sabatier (Toulouse III) for documentation (Doc. J 2 791v2)

 INTRODUCTION

Filtration membranes (reverse osmosis RO, nanofiltration NF, ultrafiltration UF, microfiltration MF) are semi-permeable (permselective) membranes that retain solutes or particles in a solvent. Membranes are usually composed of a selective layer ensuring separation, combined with a support reinforcing mechanical resistance. Their performance, which corresponds to that of the selective layer, is characterized by their solvent permeability (see [J 2 790] ) and selectivity.

The latter characteristic is linked to membrane pore size, expressed in terms of cut-off (molar mass of the compound retained at 90% (cf. ) (UF, NF), salt retention (NF, OI) or micrometer size (MF). Figure 1 shows schematically the correspondence between membrane filtration operations, pore size and retained compounds.

Positioning of membrane filtration operations relative to pore size and retained compounds (from Osmonics doc.)
Figure 1  -  Positioning of membrane filtration operations relative to pore size and retained compounds (from Osmonics doc.)

In practical terms, a membrane must have high permeability combined with high selectivity, and thermal, chemical and mechanical resistance, at a controlled installation and renewal cost in line with the product application in question.

Permeability is related not only to pore size and density, but also to the thickness of the selective layer, as shown by Poiseuille's law (see

You do not have access to this resource.

Exclusive to subscribers. 97% yet to be discovered!

You do not have access to this resource.
Click here to request your free trial access!

Already subscribed? Log in!

The Ultimate Scientific and Technical Reference

A Comprehensive Knowledge Base, with over 1,200 authors and 100 scientific advisors
+ More than 10,000 articles and 1,000 how-to sheets, over 800 new or updated articles every year
From design to prototyping, right through to industrialization, the reference for securing the development of your industrial projects

This article is included in

Water technologies

This offer includes:

Knowledge Base

Updated and enriched with articles validated by our scientific committees

Services

A set of exclusive tools to complement the resources

Practical Path

Operational and didactic, to guarantee the acquisition of transversal skills

Doc & Quiz

Interactive articles with quizzes, for constructive reading

Subscribe now!

Ongoing reading
Membrane filtration (RO, NF, UF)
Outline