Veolia Water Technologies Ireland

Dublin Road 


Co. Kildare

Tel: + 353 1 630 3333
Fax: + 353 1 630 3344



Reverse Osmosis

Reverse osmosis (RO), with its exceptional purifying efficiency, is a very cost-effective technology for the removal of the majority of impurities. RO membranes are typically thin film polyamide and are stable over a wide pH range.

RO membranes are used to remove:

  • Water contaminants that are less than 1 nm diameter
  • Typically over 90% of ionic contamination, most organic contamination
  • Nearly all particulate contamination

How RO Works TO Remove Contaminants

During reverse osmosis, feedwater is pumped past the input side of a RO membrane under pressure (typically 4-15 bar, 60-220 psi) in cross-flow fashion. Typically 15-30% of feedwater passes through the membrane as permeate and the rest exits the membrane as a concentrate that contains most of the salts, organics, and essentially all particulates.


  • Effective removal of contaminants such as colloids, pyrogens etc
  • Minimal maintenance and easy to monitor


  • Gases are not removed
  • Pre-treatment is required to avoid contaminants damaging membrane