Reverse Osmosis (RO) is a process of physical separation of dissolved solids and minerals present in water. This technology uses the principle of osmosis, wherein the mineral concentration of raw water is reduced by applying high pressure through a semi-permeable membrane.

In the process of Reverse Osmosis, a high pressure pump is used to increase pressure on the salt side of RO and force water across the semi-permeable RO membrane that leaves around 95% to 99% of dissolved salts. Amount of Pressure required depends upon the concentration of salt in the feed water.