How Do These RO Membranes Work?
The most important part of any RO system are the membranes. In a typical RO system, membranes are made of two- to eight-inch diameter sized, spiral wound sheets of semi-permeable material designed to let pure water flow through, while keeping back all other impurities. Within industrial applications, the standard length of each membrane has been set to forty inches. These membranes, typically six at a time, are loaded into single housings, which are then arranged into several parallel flow streams, or stages. Typically, reverse osmosis systems contain multiple stages in a single series, as explained above. The more stages, the less water is wasted as each stage reclaims some of the wastewater from the previous stage.
Using pressure and force (typically from a pumping system), the natural process of osmosis is reversed via feed water being pushed through the semi-permeable membranes, overcoming the natural process of osmosis, and leaving the impurities behind, while the filtered water continues through the system. Once this has been achieved, the highly purified water can be reused for a plethora of other purposes, while the “rejected” impurities are flushed to drain or are recycled for cooling water or other potential uses.