This ITG will focus on the chemical and microbiological quality of water produced by reverse osmosis.
Water molecules can form hydrogen bonds in the RO membrane and fit into the membrane matrix.
The water molecules that enter the membrane by hydrogen bonding can be pushed through under pressure. Salt ions, on the other hand, are rejected by a mechanism related to the valence of the ion. Monovalent ions such as chloride ions will not be rejected as efficiently as, for example, divalent sulfate ions. The majority of the commercially manufactured RO membranes are made from cellulose acetate, polysulfonate, and polyamide. Many other kinds of membrane made of a single polymer or a copolymer are also available for specific purposes.