The process of reversing the direction of osmosis by applying the pressure higher than the osmotic pressure to the solution of higher concentration is called reverse osmosis. During reverse osmosis, the pure solvent flows out of the solution through the semi permeable membrane. Reverse osmosis is used in desalination of sea water. When pressure, more than osmotic pressure (30 atm at 25°C) is applied to the sea water, pure water is squeezed out of the sea water through the semi permeable membrane as shown in figure.
