Capacity of ion exchange resins:

The capacity of ion exchange resins to erase impurity ions is provided in Table 2 along within other information on resins.   For example, every cubic foot of a mixed-bed resin is capable of exchanging along with 19.8 moles every of monovalent cations and anions. The Mixed-bed resins are available commercially and in practical applications various cubic feet are used in a purification system.

The ion exchange procedure is reversible. The exchange might reverse, and undesirable ions or other substances which were previously removed if too much solution is passed by the ion exchanger (that is, the capacity of the resin has been exceeded), will be returned to the solution at the effluent. Thus, it is essential to periodically monitor the performance of the ion exchanger and either replace or reproduce the resin while denoted. Ion exchanger performance is measured through comparing the solution conductivity, concentration, or radioactivity at the effluent and influent. The parameter measured depends upon the reason of the ion exchanger. The word generally applied to ion exchanger efficiency is decontamination factor (DF), that is described as a ratio of the concentration (or activity) of the fluid at the inlet compared to the concentration (or activity) at the effluent, that expresses the efficiency of an ion exchange procedure.

DF = Influent conductivity, concentration, or radioactivity/Effluent concentration, conductivity, or radioactivity