Reverse Osmosis is the process which occurs when a saline solution is put in contact with a water permeable membrane (but impermeable to the dissolved solids) at a pressure higher than the osmotic pressure of the solution. A high pressure pump is used to increase the pressure on the salt side of the RO and force the water to flow across the semi-permeable membrane., leaving most part (approximately 95%-99%) of the dissolves salts behind the stream. Within the membrane system, the feed water will be split into a low-saline product, called permeate, and a high saline solution, called concentrate, brine or reject stream Reverse osmosis is capable of removing dissolved salts (ions), particles, colloids, organics, bacteria and pyrogens from the water.