The alternative to ion-exchangers
As an alternative to ion-exchangers, the electrochemical de-ionization (EDI) can be used for residual water desalination. In the EDI the classical ion exchanger technology is coupled with modern membrane technology.
A decisive advantage of the EDI against the pure ion-exchanger procedure is that it is about a continuous procedure. Whereas ion-exchangers have to be regenerated in regular intervals. During these times no desalinated water can be produced. Regeneration of an EDI, however, is done during operation. Therefore, a redundant design of this plant is not necessary for permanent operation.
Since the salt load with EDI is very low, merely a small partial current amount for waste-water respectively electrode cleaning is required. Consequently, there is a high yield with EDI.
For an efficient EDI operation, the carbon acid content in water has to be as low as possible, therefore, we always recommend to install an upstream carbon dioxide degassing unit.