In the last blog post we learned what osmosis was and saw a visual of what it was. To reiterate, in Osmosis cleaner water moves from the less concentrated side of a semipermeable membrane into the side where there is contamination. The problem with this is is that we can never achieve high purity water because there will always be contaminants on both side of the membrane.

Enter Reverse Osmosis. In this process we apply pressure, generally via pump to the contaminated side of the membrane, counteract the osmotic pressure, and literally force clean water out the other end of the semipermeable membrane. Hence the name, Reverse Osmosis.

It is important to note the the osmotic pressure that the pump must overcome in order to send water in the reverse direction of osmosis increases with the amount of solute/salts/ minerals in the feed water. As an example, a simple tap water RO unit can operate on as little as 50 psi while salt water systems may require 600 psi or even more.

STAY TUNED FOR PART THREE – BUILDING AN RO SYSTEM