What is desalination?

Desalination refers to several processes that remove excess salt and other minerals from water. Processes of separation include reverse osmosis, nanofiltration, ultrafiltration, microfiltration and particle filtration. Each process differs according to the size of material that it can identify and remove.
Water is desalinated in order to convert salt water to fresh water so it is suitable for human consumption or irrigation. Sometimes the process produces table salt as a by-product.
Membrane water treatment systems are part of the desalination process. Water treatment membranes are thin sheets of material that are able to separate contaminants based on properties such as size or charge. Water passes through a membrane and larger particles, microorganisms, and other contaminants are separated out.