What is Reverse Osmosis?

Soon, everyone will know the benefits of reverse osmosis. Reverse Osmosis equipment has only been manufactured for the household consumer for just a few years. Until recently, it was used primarily by major corporations and the U.S. Government for purifying non-potable water supplies throughout the world. It was, and still is, used on large military and commercial ships for purifying seawater making it suitable for human consumption.

Reverse Osmosis (RO) is often described as filtration, but it is much more complex than that. People sometimes explain it as a filter because it is much easier to visualize using those terms. We should remember that osmosis is how we feed each cell in our bodies: As our blood is carried into the smallest of capillaries in our bodies, nutrients actually pass through the cell wall to sustain it's life. Reverse osmosis is just the opposite: We take water with "nutrients" (in this case, junk) in it, and apply pressure to it against a certain type of membrane, and, presto -- out comes "clean" water.

For example: If you take a jar of water and place a semi-permeable membrane (like a cell wall) in it, dividing the jar into two sections, then place water in both sides to an equal level, nothing happens. But, if you place salt (or other such dissolved substance) into one side of the jar, you will notice that, after awhile, the water level in the salty side begins to rise higher as the unsalted side lowers. This is osmotic pressure at work: The two solutions will continue to try to reach the same level of salt (equilibrium) on each side by the unsalted water passing through the membrane to dilute the salty water. This will continue until the "head" pressure of the salt water overcomes the "osmotic" pressure created by the differences in the two solutions.

On the other hand, researchers have discovered that if we take that membrane and feed water with sufficient pressure to overcome the osmotic pressure of the two waters, we can 'manufacture' clean water on the side of the membrane that has no pressure.



We sometimes say we "filter" the water through the membrane. Depending on the membrane design, and the material it is made from, the amount of TDS (total dissolved solids) reduction will range from 80 to over 99 per cent. Different minerals have different rejection rates, for instance, the removal rate for a typical TFC (Thin Film Composite) membrane is 99.5% for Barium and Radium 226/228; but only 85.9% for Fluoride and 94.0% for Mercury. Removal rates are also very dependant on feed-water pressures.

Reverse osmosis is a fairly new, advanced leading-edge technique which separates the very smallest particles, molecules and ions. Reverse osmosis supplements conventional filtration techniques, it takes up where the conventional filtration methods are not able to show any effects.

With conventional techniques little of "the pollutants" are separated compared with reverse osmosis which separates a percentage of pure water and leaves behind all the substances which the water contained before becoming pure water.

The water supplied by most municipal water works and most softened well waters are an excellent base product or feed water for reverse osmosis, which produces excellent pure water – drinking water.