Production of ultrapure water by continuous electrodeionization

The process of continuous electrodeionization (CEDI) has now been in commercial use for over twenty years and has gained widespread acceptance in the production of ultrapure process water for industrial use. Likely the chief reason for its commercial success is that CEDI is a green process. It substitutes electricity for the hazardous chemicals normally used to regenerate ion exchange resins, and thereby eliminates the waste stream associated with resin regeneration. This paper describes the mechanisms of operation, types of device construction, and principal industrial applications of this relatively new water purification technology.