Monday, February 13, 2012

What is Reverse Osmosis?

By applying a pressure that exceeds the osmotic pressure, the reverse effect occurs. Fluids are pressed back through the membrane, while dissolved solids stay behind.

To purify water by Reverse Osmosis membrane, the natural osmosis effect must be reversed. In order to force the water of the brine stream (high salt concentration) to flow towards the fresh stream (low salt concentration), the water must be pressurized at an operating pressure greater than the osmotic pressure. As a result, the brine side will get more concentrated.
The operating pressure of seawater is around 60 bar.



1. Water flows from a column with a low dissolved solids content to a column with a high dissolved solids content

2. Osmotic pressure is the pressure that is used to stop the water from flowing through the membrane, in order to create balance

3. By pursuing pressure that exceeds the osmotic pressure, the water flow will be reversed; water flows from the column with a high dissolved solids content to the column with a low dissolved solids content