Electrodialysis is a mature process which is applied since more than 50 years on a large industrial scale for the production of potable water from brackish water sources But more recently electrodialysis in combination with bipolar membranes or with ion-exchange resins has found a large number of new interesting applications in the chemical process industry in the food and drug industry as well as in waste water treatment and the production of high quality industrial water In this paper the principle of electrodialysis is described and its advantages and limitations in various applications are pointed out More recent developments in electrodialysis as well as in related processes such as electrodialytic water dissociation or continuous electrodeionization are discussed and their present and potential future applications are indicated Research needs for a sustainable growth of electrodialysis and related processes are pointed out (C) 2010 Elsevier B V All rights reserved