Drinking water and process water
In an abstract sense reverse osmosis can be seen as a form of filtration whereby water under pressure passes through semi-permeable membranes. The soluble salts are retained.
The application of pressure on the side of the salt solution which exceeds the osmotic pressure reverses the process, i.e. water passes through the membrane from the salt solution to become pure water whereby the salt content of the remaining concentrate and its osmotic pressure increases.
This process is called reverse osmosis. Reverse osmosis is therefore a continuous process at ambient temperatures for the dewatering or thickening of salt solutions where the solution under pressure is directed past a membrane system and in this process gives off a part of its water with only minimal salt content as a permeate through the membranes. The result of the process is therefore a constant flow of pure water with a low salt content.