ABSTRACT
Usually, the ion exchangers with high specificity have polar groups which form strong complexes or tend to form precipitates with the ion in question, e. g., dipicrylamine with potassium, dimethylglyoxime with nickel. The volume of a feed that can be treated by a given volume of exchanger regenerated with a given dosage of regenerant depends on the ionic concentration and on the ionic selectivities. If two or three ions have nearly the same selectivities, all will be removed at the same time. Only when the selectivity values are much different can one ion be preferentially removed when in the presence of other ions. Thus it would be difficult to remove zinc from a solution containing magnesium ions, since the selectivities of the two ions are nearly the same. Information on the use of the ion exchangers for specific commercial applications is quite limited.
