Chapter 6 Ion-Exchange Membrane Processes in Water Treatment

Abstract

Abstract Electrodialysis has been one of the first commercially available large scale water desalination processes based on membranes. However, in spite of a long term reliable operation experience in brackish water desalination and waste water treatment electrodialysis is replaced more and more by reverse osmosis and nanofiltration which have especially in the production of potable water from sea water a clear cost advantage. In recent years a number of electrodiaysis related processes such as diffusion dialysis or the electrodialytic water dissociation with bipolar membranes, continuous deionization or capacitive deionization have been developed. These processes are now commercially available and widely used in the treatment of certain industrial effluents, in the production of ultrapure water or in deionization of food and pharmaceutical products. In this chapter the fundamentals and major applications of commercially available electromembrane processes are briefly described. More recently developed products and processes are discussed. Their technical as well as economic advantages are described, and potential future applications indicated. Research needs for a sustainable growth of electromembrane processes are pointed out.