Deionization technologies are used to remove ions dissolved in water through ion exchange, usually by means of an ion exchange resin or electrical deionization device.
Substances such as calcium, sodium and silica have a positive or negative charge in water and dissolve either as cations (positively charged ions) such as calcium ions or sodium ions or anions (negatively charged ions) such as silicate ion.
These ions are removed from water by means of an ion exchange resin or ion exchange membrane.
For example, in water purification, a spherical resin 0.5 mm in diameter called an ion exchange resin is used to remove ions from water. Based on the functional group on its surface, an ion exchange resin binds with positive ions or negative ions in water, releasing hydrogen ions or hydroxide ions instead. Alternatively, a membrane called an ion exchange membrane that selectively allows certain ions to pass through is used and an electrical current is passed through the water, causing the ions in the water to move and separating them into cations and anions.
Kurita provides water purifiers using ion exchange technologies according to the types and properties of the ions to be removed and the purity of the treated water.