What is the Reverse Osmosis (RO) Process?
Reverse Osmosis Systems (RO) : Water pressure is used to force water molecules through a very fine membrane leaving the contaminants behind. Purified water is collected from the "clean" or [permeate" side of the membrane, and water containing the concentrated contaminants is flushed down the drain from the "contaminated" or [concentrate" side. The average RO system is a unit consisting of a sediment/chlorine pre filter, the reverse-osmosis membrane, a storage tank, and an activated-carbon post filter.
Reverse osmosis removes salt and most other inorganic material present in the water, and for that reason, RO lends itself to use in places where the drinking water is brackish (salty), contains nitrates or other dissolved minerals which are difficult to remove by other methods.