Reverse osmosis membranes should possess the following characteristics: (1) high desalination rate at high flow rates; (2) high mechanical strength and service life; (3) ability to function at low operating pressures; (4) tolerance to chemical or biochemical effects; (5) minimal impact from factors such as pH and temperature; and (6) readily available raw materials, simple processing, and low cost.
Reverse osmosis membranes are classified into two types: asymmetric membranes and homogeneous membranes. Currently used membrane materials are mainly cellulose acetate and aromatic polyamides. Their components include hollow fiber, spiral wound, plate and frame, and tubular types. They can be used for separation, concentration, purification, and other chemical unit operations, primarily in pure water preparation and water treatment industries.