Principles of Reverse Osmosis Membrane

(1) Osmosis

Osmosis is a natural phenomenon, the spontaneous passage of water through a semi-permeable membrane. When two fluids, fresh water and brine water, are separated by a semi-permeable membrane that is permeable to fresh water but not to salt, brine water will become more diluted by absorbing fresh water through the membrane or fresh water. It will start flowing through the membrane to the brine side. This process is named osmosis.

(2) Osmotic Equilibrium

Osmotic pressure varies according to temperature and concentration of the brine water, however, as fresh water passes through the membrane, the levels of the two solutions become unequal. The resulting difference in pressure eventually brings the migration to a stop. This pressure difference is called osmotic pressure of the brine water.

(3) Reverse Osmosis

Reverse osmosis is the process of forcing the water from the salt waterside through a membrane to the fresh waterside by applying excess pressure.

This process is used in treating sea water to get fresh water.