Definition given by Wikipedia
Reverse osmosis (RO) is a water purification process that uses a reverse osmosis membrane to separate any impurities larger than 0.0001micron such as ions, unwanted molecules and larger particles from drinking water. In the process of reverse osmosis, applied pressure is used to overcome osmotic pressure. Reverse osmosis can remove many types of dissolved and suspended chemical species as well as biological ones (principally bacteria) from water, and is used in both industrial processes and the production of potable water.
Simply put, Reverse Osmosis is a technology that is used to remove a large majority of contaminants from water by pushing the water under pressure through a semi-permeable membrane named reverse osmosis.
Understanding Reverse Osmosis
Reverse osmosis, commonly referred to as RO, is a process in which water is demineralized or deionized by pushing water through a semi-permeable reverse osmosis membrane under pressure.
Osmosis Explained
To understand the purpose and process of reverse osmosis, you must first understand the naturally occurring osmosis process. Osmosis is a naturally occurring phenomenon and one of the most important processes in nature. In this process, the weaker saline solution tends to migrate to the strong saline solution. An example of osmosis is that the roots of plants absorb water from the soil, while our kidneys absorb water from the blood.
Reverse Osmosis Explained
To reverse the osmosis process, you need to apply more energy to the saline solution. A reverse osmosis membrane is a semi-permeable membrane that allows water molecules to pass through, but does not allow most of the dissolved salts, organic matter, bacteria and pyrogens to pass through. However, you need to “push” the water through the reverse osmosis membrane by applying a pressure greater than the natural osmotic pressure, so that the water is filtered (desalination or deionization) in the process, allowing pure water through while holding back a majority of contaminants. An example of reverse osmosis is seagulls filter seawater into drinkable freshwater, while seawater containing impurities and highly concentrated salts is spit out.