The term reverse osmosis (RO) probably rings a bell but you might not have thought about what it means since your last high school chemistry class. It’s a technology that has been well known for over two hundred years but is only now becoming commonplace in industry and private homes through the increasing use of water purifying systems.
What is Reverse Osmosis?
Just as the name implies, reverse osmosis performs the opposite function that osmosis does naturally. For a refresher course on osmosis think of red blood cells, which have a high concentration of protein and salt, when they are placed in a lower concentration fluid like water, the water will rush into the red blood cells. In reverse osmosis it’s about pulling something out. In nature this can be seen in seagulls that have a unique membrane that filters out the salt from seawater, allowing them to drink fresh water miles out at sea. Today this same technology is being used to ensure purity in our fresh water and to convert seawater to usable water for industry.
How Does Reverse Osmosis Work?
The secret to a reverse osmosis system is semi-permeable, film composite membrane (TFM or TFC) on top of a highly porous, thicker substrate membrane, which is typically made from cellulose acetate, polysulfonate, and polyamide. Applied pressure pushes the liquid through the membrane, separating the unwanted contaminants from the filtrated water. This technology is most often used to convert sea water to fresh water for industrial cooling systems, such as in nuclear plants; however, it is becoming more common in everyday use, as well.
Who Does Reverse Osmosis Benefit?
In developing countries where fresh water is scarce reverse osmosis systems are taking on a lifesaving role by harvesting the water from oceans and turning it into fresh, potable water for cooking and drinking for millions of people. In more advanced nations reverse osmosis is found in homes as part of common water filtration systems. It’s a technology that’s here to stay as we learn more about the chemicals that are a part of our water supply.
A Fresh Water Supply
Reverse osmosis is quickly becoming a commonplace feature in our lives today, thanks to the continued work of designers who learned that chemistry lesson well in their high school days. And because of their ingenuity a fresh water supply will be available to us every time we turn on our faucets.