Electrodeionisation (EDI) is a technology which uses ion exchange resins and ion-selective membranes in combination with direct current to remove ions from the water. The fact that it is possible to regenerate an ion exchanger not only with acids and alkalis, but also using an electric field, was a revolutionary idea and laid the foundation for the development of modern electrodeionisation processes.
About the process: An EDI module consists of several chambers that are separated by ion-selective membranes. The chambers are filled with ion exchange resin and are placed between two DC electrodes. The DC voltage applied makes the ions in the EDI feed water migrate to the corresponding electrode: Cations are attracted by the cathode and anions by the anode. Because the ion-selective membranes are positioned inversely, the ions are collected in the channels between the chambers and carried out of the module by a partial stream, the EDI concentrate flow.
EnviroFALK electrodeionisation units are available
- in various sizes,
- flow capacities and materials
- with chamber systems and resin fillings