Wednesday, 9 December 2015

REVERSE OSMOSIS

By,
Anupam Shahi

Reverse Osmosis is a water purification technique that uses a semi permeable membrane to remove larger particles from drinking water. In reverse osmosis,an applied pressure is used to overcome osmotic pressure. It can remove many types of molecules or ions from solutions, including bacteria and is used in both industrial processes and the production of potable water. The result is that the solute is retained on the pressurized side of the membrane and the pure solvent is allowed to pass to the other side. This membrane should not allow large molecules or ions through the pores but should allow smaller components of the solution .

                                                       
In this process ,the solvent moves from an area of low solute concentration ,through a membrane, to an area of high solute concentration.Reverse osmosis involves diffusion ,making the process dependent on pressure, flow rate.It is most commonly known for it’s use in drinking water purification from sea water, removing the salt and other effluent materials from the water molecules.
When two liquids with a different concentration  of a solute are separated by semipermeable membrane ,the fluid has a tendency to move from low to high solute concentrations for chemical potential equilibrium.
The most important application of reverse osmosis is the separation of pure water from seawater and brackish water.