What is defined as water that has been forced through an RO membrane?

Product water is the term used to describe the water that has been treated by reverse osmosis (RO) and has successfully passed through the RO membrane. In the RO process, the incoming water, referred to as feed water, is subjected to high pressure to overcome the natural osmotic pressure, forcing water molecules through the semi-permeable membrane. As a result, the treated water that emerges from the other side of the membrane is the product water, which is typically purified and contains fewer contaminants than the original feed water.

The distinction between product water and other types of water in the RO process is important. Feed water refers to the untreated water that is being processed, while brine is the concentrated solution that remains after the separation process and contains the rejected impurities. Distillate is a term linked to distillation processes rather than reverse osmosis. Understanding these terms clarifies the role of product water within the overall RO system.