Technical background and details on reverse osmosis

Primary function: The Reverse Osmosis Water Purification Unit is a proven system that is capable of treating water from any available source.

Reverse osmosis (RO) is a method of purifying water for industrial processes and human consumption. RO can remove mineral salts and contaminants such as bacteria and pesticides. Advances in water treatment technologies have enhanced and complemented the conventional RO process, reducing energy and water consumption, lowering capital and operating costs, and producing purer water.

 Reverse Osmosis

Reverse osmosis is often used to treat saltwater or brackish water to create potable water. It is also used in a number of industrial processes to produce water with a high level of purity, reducing dissolved minerals and pollutants in the treated water. A stream of water, called the feed water, enters the RO system and is pressurized against a semi-permeable membrane (Figure 1).

Two streams exit the system, the concentrate and the permeate streams. The permeate is filtered, purified water. The concentrate is rejected water containing a high level of dissolved minerals. The concentrate is sent to drain, or a portion of it is recycled back to the feed stream to increase the system’s overall water recovery. The recovery rate (i.e., the ratio of the volume of permeate to the volume of the feed water) is typically about 75% for a conventional RO system operating on a city water supply.