What is Osmosis?

Osmosis is a natural process discovered more than 200-years ago and is common in many plant and animal membranes.

Osmosis can be defined as the spontaneous flow of a liquid from a dilute solution to a highly concentrated solution through a semi-permeable membrane, which allows the passage of solvent, but not that of dissolved substances.

In the case of aqueous solutions, water flows from one side of the membrane to the other until a differential pressure is built up, which prevents a further flow of water. The pressure, which has been reached, is equal to the osmotic pressure of the concentrated solution.

Osmosis is a reversible process. If the concentrated solution is subjected to an external pressure, which is higher than the osmotic pressure, the water flows in the opposite direction. This represents reverse osmosis. In this way, pure water can be expelled from an aqueous solution by mechanical work.

Our Reverse Osmosis systems feature large areas of synthetic sheet membrane wrapped in a spiral and inserted in a pressure housing – this is called a membrane module. Water is pumped into the module of a fixed rate and pressure. A percentage of the volume passes through the membrane and is collected as fresh water – the remaining water flowing over the membrane surface, carries the excess salts, and impurities to waste. This action prevents the membrane surface from fouling.