Reverse Osmosis (RO) is a water purification technology that uses a semipermeable membrane to remove ions, molecular contaminants and larger particles from water. In reverse osmosis, an applied pressure greater than the osmotic pressure of the pure water is used to drive the purified water across the membrane. Reverse osmosis can remove many types of dissolved and suspended species from water, including bacteria, which remain on the pressurized side of the membrane, and is used in both industrial processes and the production of potable water.