| Abstract: |
Initially ion exchange (IX) units used the co-current technique, which is regarded as an IX process of first generation deionization systems. In Western Europe today only older, smaller plants or softener units still operate as co-current systems, whereas bigger and more modern plants are operating with counter-current (i.e., fluidized-bed technology). In Asia, Eastern Europe, and the United States, the counter-current, counter-pressure systems used today are widely established, and even used in power plants.
This article provides a general overview of the various existing IX processes classified by co- and counter-current technology. Each process will be described by its characteristics, operation mode, and relevant advantages and/or disadvantages. |