What is 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 and nearly all particlate contamination
How reverse osmosis removes 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.
Advantages and Restrictions
- 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