Fundamentals of ion exchange fixed-bed operations

As a physical phenomenon, ion exchange is basically a subject of physical chemistry, while fixed bed is a common reactor studied in chemical engineering. Furthermore, it is a subject bringing together the experimentalists and the modeling scientists, who in the typical case have different views on the same system. This interrelation of several sciences and approaches is by no means a particularity of ion exchange fixed-beds field. The experience of the authors and the study of the related published research in journals for many years indicate a clear gap in many scientific publications, where authors are frequently missing aspects which are well known to other scientists working on the same subject. This chapter comes to fill the gap and in the same time to balance between all these different views of scientists with different approaches and background. It should be mentioned that the principal target of this work is to analyze the fundamentals of the operation (fixed bed) and not the physical chemistry of the phenomenon (ion exchange), which is a subject of other chapters in the present book. From this point of view, the authors have followed the most common approach, in which ion exchange is treated as a sorption process when it comes to the design of fixed-bed processes. Consequently, the authors consider this chapter as an added value for the related literature.