Ion Exchange Resins for Water Treatment - Part 1: Theoretical

The success of the course launched in 2021 motivated us to expand and review all topics, which is even better and more complete now. The presentation has improved both image and sound quality. We counted around 80 students until February/2025 in this plataform (in Portuguese version).

The training is extensive and covers everything from historical aspects of ion exchange resins to a very detailed theoretical basis – including the concept of separation factors, the various configurations of the four types of resins available on the market.

The course is divided into seven chapters, and we will briefly comment on each of them (this course is about chapters 1, 2 and 3).

In the first chapter, we will cover the basic concepts necessary to understand this technology. Main topics covered: historical review, chemical structure and types of resins, units, water contaminants that can be removed with this technology, and the first simple examples of softener sizing calculations.

In the second chapter, the concepts are expanded, and we will see what “Service Flow Rate”, “Linear Flowrate”, "Selectivity" and "Cross-linking" represent. The theory of Selectivity and Separation Factors will also be presented, which explains why very simplified calculations can result in large sizing errors, simply because the water contains a more selective contaminant than the species to be removed.

Finally, we will learn how to calculate dimensional systems using another calculation method, presented by Anderson in 1975.

In the third chapter, the enemies of resins will be presented and what type of damage they cause to them, as well as "Preferred Paths" or "Channeling" and the applicability of WAC-type resins for alkalinity removal.