It is used before ion exchange system as a means for pre-desalination and can extend the regeneration cycle of the ion exchange system.

A great deal of saline wastewater containing Cl -, Ca2 + and Mg2 + from the ion exchange system of steam boiler is discharged during the regeneration of resin.

At present, nuclear engineers clean cobalt from the system by trapping it in what are known as ion-exchange resins.