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How Reverse Osmosis Desalinators Work


Using Reverse Osmosis Desalinators
Reverse osmosis desalinators make seawater into delicious freshwater.
Reverse osmosis desalinators make seawater into delicious freshwater.
©iStockphoto.com/romakoshel

Reverse osmosis desalinators can operate on both large and small scales. A backpacker or boating enthusiasts can purchase a reverse osmosis desalination system for personal use, or they can be acquired by larger industrial or community groups in need of freshwater.

Many communities in equatorial zones, arid environments and coastal areas are good candidates for reverse osmosis desalination systems because they generally have available seawater but lack freshwater. For example, places like California, Florida, the Caribbean, Central and South America, the Mediterranean, the Middle East and the Pacific Rim are areas in which reverse osmosis desalination could be a viable option for the production of freshwater on a large scale.

In comparison to two other desalination processes, distillation and freeze-thawing, reverse osmosis is the most cost effective and energy efficient. For example, while distillation require 30-186 horsepower of mechanical energy to remove one gallon (3.7 liters) of water from saline solution, reverse osmosis desalination only needs about 0.5-1.4 horsepower [source: Desalination: FAQ].

In addition to being energy efficient, reverse osmosis desalinators are also smaller in size than other desalination units. On a larger scale, they are also less costly to purchase and operate. Most desalinators are run by electricity; however, if electricity is not available or too expensive, you can also use a diesel or solar-powered desalinator. Although solar powered desalinators are initially more expensive to purchase, the energy savings may pay off in the end.

To take care of your reverse osmosis desalinator, make sure to keep an eye on the day-to-day operation of the system. Make sure to adjust the calibration and pumps for leaks or structural damage. The main problem that you can run into with reverse osmosis desalinators is fouling, when membrane pours become clogged. To prevent fouling, clean the unit every four months or so and replace filter elements about once every eight weeks.