A reverse osmosis water treatment system is a system that purifies water by using pressure to push the water through a membrane to remove impurities. Osmosis is the process of liquid moving from an area of high water potential and low solute or particulate matter through a membrane or filter to an area of low water potential and high solute or particulate matter. During the process of osmosis, no external pressure is applied; the water is allowed to move naturally through the membrane. Reverse osmosis occurs when external pressure is applied to move liquid across a membrane from an area high in solutes to an area low in solutes.
Of the many water purification techniques, a reverse osmosis water treatment system is the most reliable at removing many different types of impurities from water. Although it may seem a bit complicated, the system is comparatively simple. Besides the membrane, which acts like a filter, the most important part of a reverse osmosis water treatment system is the amount of pressure applied to move the water through the membrane. The amount of externally applied pressure must be greater than the natural pressure to maintain salt ions or other impurities within the water.
When considering drinking water purification systems, a reverse osmosis water treatment system is commonly used by people who do not have access to treated drinking water. While relatively simple to understand, this system usually includes a number of steps. The system must have a membrane or filter to trap impurities. Activated charcoal is often used to filter out organic chemicals and chlorine. Specific systems may have an activated charcoal filter on each side of the membrane to capture as much organic material as possible, and an ultra-violet lamp is sometimes used to destroy any germs that escape the other filters.
In the United States, Los Angeles and other major cities use a reverse osmosis water treatment system to purify storm drain water for use in landscaping. The United States military possesses its own reverse osmosis water treatment system. These units are called Reverse Osmosis Water Purification Units (ROWPU), and they are industrial-sized water treatment tanks that can sustain a military unit of more than 1,000 soldiers. The reverse osmosis units can remove salts and sediments as well as nuclear, biological and chemical agents. The size of the membrane’s pores determines the size of the particles it is capable of filtering out.