After water passes through a reverse osmosis filter, it is essentially pure water. In addition to removing all organic molecules and viruses. Reverse osmosis filters have the smallest size of membrane of al filtration methods about 0.0001 microns. Reverse osmosis removes turbidity, monovalent ions (desalination) including microbes and virtually all dissolved substances.
To understand how reverse osmosis works, it is helpful to understand osmosis. Osmosis occurs when a semi-permeable membrane separates two salt solutions of different concentrations. Water will migrate from the weaker solution to the stronger solution until the two solutions have the same concentration because the semipermeable membrane allows the water to pass through, but not the salt.
In reverse osmosis, the two solutions are still separated by a semi-permeable membrane, but pressure is applied to reverse the natural flow of the water. This forces the water to move from the more concentrated solution to the weaker one. Thus, the contaminants end up on one side of the semi-permeable membrane and the pure water on the other.
Reverse osmosis treatment system can be a worthwhile investment for healthy and safe drinking water.