Reverse Osmosis is a process that was discovered and understood well enough to be made reliable about 40 years ago
On the right is a diagram which depicts a “Reverse Osmosis Plant”. Though much simplified basic it is showing the the size of the hole in the membrane
which the water passes is smaller the even the size of say a virus. This diagram is not to scale represents the process approximately.
Reverse osmosis is now used in commonly in the home as well as industries such has medicine and pharmaceuticals as away of purifying or separating water and other impurities from it.
Reverse Osmosis: A Scientific View (Explained Simply)
Reverse Osmosis explained simply is hard to do but it is a considered complex process which uses a series membranes under pressure to separate relatively pure water (or other solvent) from a less pure solutions. When 2 aqueous (liquid) solutions of different concentrations are separated by a semi-permeable membrane, water can pass through the membrane in the direction of the more concentrated solution as a result of osmotic pressure. If enough counter pressure is applied to the concentrated solution to overcome the osmotic pressure, the flow of water will be reversed.
Here is a great prezi which explains the process.
Quality of Reverse Osmosis Product Water
The amount of dissolved solids in water produced by reverse osmosis is approximately a constant percentage of those in the feed water. So if you live in an with a great deal of disolved solids in the water you will need to replace the cartridges in you system more often to keep the Reverse Osmosis system in peek condition. You can buy replace cartridges here or a complete 5-stage reverse osmosis system which fits under your sink