Reverse Osmosis is a technical breakthrough initially developed by the US government to provide fresh drinking water for the Navy and NASA. Following World War II, the US government began investing hundreds of millions of dollars to determine the best methods of treating drinking water against harmful chemicals and minerals.
Although the idea of reversing osmosis has been known for many years, the practical, affordable application in day to day living is a recent development. Today, reverse osmosis remains the most viable and economical method of fully treating our drinking water.
Understanding Osmosis
Assume a membrane is semi-permeable, allowing water to pass through while being closed to dissolved salts. If you place this membrane between two compartments in a container, with a salt solution in one half of the container and pure water in the other half, a fundamental scientific principle comes into play.
The two different concentrations of liquids within the same system will try to reach equilibrium (i.e. the same concentration of contaminants) on both sides of the membrane. Of course, the only way for this to happen is for pure water to pass through the membrane to the salt water side in an attempt to dilute the salt solution.
This attempt to reach equilibrium is called osmosis.
Understanding Reverse Osmosis
Reverse Osmosis is the reversal of the natural flow of osmosis.
In a water purification system, the goal is not to dilute the salt solution, but to separate the pure water from the salt and other contaminants.
When the natural osmotic flow is reversed, water from the salt solution is forced through the membrane in the opposite direction by application of pressure - thus the term Reverse Osmosis.
Through this process, we are able to produce pure water by screening out the salts and other contaminants.
Home Drinking Water
Reverse Osmosis (RO) can be used to purify tapwater for drinking in homes. This application is generally referally to "as point of use" (POU).
In addition to removing excess or harmful minerals, reverse osmosis removes odor, color and other organic compounds, which contribute to bad taste or health concerns.
Benefits of RO water include:
Safer drinking water: Consumers want safe, healthy, good-tasting water. RO purified water meets the requirements of the Safe Drinking Water Act and EPA standards for drinking water.
Good taste: RO removes excess minerals, odor, color, and other organic compounds that contribute to bad taste.
Health: RO membranes provide a barrier to bacteria and virus resulting in healthier water for drinking and cooking (better tasting coffee and other beverages, soups and water for general cooking). RO purified water is also better facial rinsing water.
