Answer:-

Reverse osmosis:- osmosis is a flow of solvent through a semipermeable membrane into the solution. The direction of osmosis can be reversed by applying a pressure larger than the osmotic pressure.

The pure solvent then flows from solution into pure solvent through semipermeable
membrane. This phenomenon is called reverse osmosis. Fig. shows the schematic set up for reverse osmosis. Fresh water and salty water are separated by a semipermeable membrane. When the pressure larger than the osmotic pressure of solution is applied to solution, pure water from salty water passes into fresh pure water through the membrane.