De-Ionisation

De-ionised water, also known as de-mineralised water (DI water), is water that has had its mineral ions removed, such as Cations from sodium, calcium, iron, copper and Anions such as chloride and bromide.

De-ionisation is a physical process which uses specially-manufactured ion exchange resins which bind to and filter out the mineral salts from water. As the majority of water impurities are dissolved salts, de-ionisation produces a high purity water that is generally similar to distilled water, and this process is quick and without the problems associated with scale build up. However, de-ionisation does not significantly remove uncharged organic molecules, viruses or bacteria, except by incidental trapping in the resin. Specially made strong base anion resins can remove Gram-negative bacteria. Deionisation can be done continuously and inexpensively using electrode-ionisation.