Electrodialysis with Bipolar Membrane System and Process Design

1 Electrodialysis with Bipolar Membrane System and Process Design 

The design of an electrodialysis process with bipolar membranes is closely related to that of a conventional electrodialysis desalination process. 

Because of the relatively high concentrations of the acid and base as well as the salt solution the limiting current density is in general no problem and a bipolar membrane stack can generally be operated at very high current densities compared to an electrodialysis stack operated in desalination. However, membrane scaling due to precipitation of multivalent ions such as calcium or heavy-metal ions is a severe problem in the base-containing flow stream and must be removed from the feed stream prior to the electrodialysis process with a bipolar membrane. 

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