for ionic range (aqueous salts)
Reverse Osmosis, or RO, is the finest available membrane separation technique. RO separates very fine particles or other suspended matters, with a particle size up to 0.0001 microns, from a liquid. It is capable of removing metal ions and fully removing aqueous salts. The basis for RO is nature’s tendency to be at equilibrium (osmosis ). It is a simple phenomena: two non identical fluids by nature want to mix and dilute until at equilibrium. If separated by semi-permeable membrane the exchange will continue until at both sides osmotic pressure is equal. Forcing these flows in reversed order is also possible. By applying enough pressure on one side of the membrane the natural osmotic tendency to equilibrium can be reversed, hence substances are separated. Reverse Osmosis most common application is to desalinate seawater and /or brackish water to fresh water suitable for human consumption. A widely used abbreviation for this process of desalination is SWRO. RO is the finest of membrane filtration it removes all organic material, minerals and desalinated to pure water.