Deionization

Whereas softening simply exchanges undesirable hardness ions for soft water ions, the deionization process actually removes all salts. Higher pressure boilers, power generators, chemical processors, electronics manufactures and even car washes have a need for water that has little or no residual salts that can react, plate out, contribute to conductivity or “poison” pharmaceuticals and so on. One of the best methods for removing salts (considered contaminants) from feed streams is the ion exchange demineralizer. These are often teamed with membrane systems and EDI for economics and reduced chemical usage.

Deminerizers regenerate spent resin using a strong acid such as hydrochloric or sulfuric acid and strong bases such as caustic to restore capacity. For this reason, ion exchange demineralizers are not commonly used in residential applications other than via portable exchange (PEDI). (See the ion exchange page for a process description.)