Reverse Osmosis, a common method for both domestic and commercial water purification has surprisingly been around since 1748! Or at least the idea for reverse of osmosis has been. Jean-Antoine Nollet first observed the phenomena of osmosis through semipermeable membranes in his laboratory over 200 years before the first U.S municipality installed the first large scale reverse osmosis system in 1977.
So how does it work?
Osmosis is actually a natural process. It occurs when two liquids of different concentrations are separated by a semipermeable membrane. This sounds more complicated than it is. Basically it just means that water wants to flow from one place to another, and if you put a filter between these two places you can get yourself some nice clean water! In home osmosis systems this filter is usually made of a thin-film composite membrane, or a TFC.
TFCs are three layered membranes composed of a thin polyamide layer, a porous ployethersulfone layer, and a non-woven fabric support sheet. Each of these layers is designed to accomplish some incredibly complex scientific process. In the end your water is scrubbed and clean, stripped of all the nasty and harmful stuff, and ready for drinking.
Not just for Water!
Water is not the only liquid that can be purified through the use of reverse osmosis. If you have ever enjoyed some warm, fluffy pancakes smothered in sticky-sweet maple syrup you have likely consumed a product that has undergone reverse osmosis! In 1946 many maple syrup producers adopted the use of reverse osmosis. They send the sap they extract from maple trees through a reverse osmosis system to remove water and give them a more pure sap extract. That sap is then boiled down giving us the delicious maple syrup we enjoy with our breakfasts 6-7 days a week!