In general terms, the capacity of an ion exchange resin is the amount of ions that can be absorb! by a certain volume of resin. The units of measurement for resin capacity may vary. For example, meq/ml, eq/l, or kilograins per cubic foot (Kgr/ft3).
Knowing the equivalent mass of a substance
The marketing with paid m!ia mass of a substance is defin! as the ratio of the molar mass of a substance to its valence (strictly speaking, to the equivalence number of the substance).
For example, the molar mass of calcium is 40 g/mol and the valence is 2, then the equivalent mass is 20 g/mol (40/2 = 20). An ion exchange resin with an exchange capacity of 1.95 g-eq/l is capable of extracting 1.95 × 20 = 39 grams per 1 litre of resin from a solution.
How is the exchange capacity of a resin determin!?
In practice, the process is carri! out in laboratories by titration. A sodium hydroxide solution (NaOH) is pass! through a column in which a sample of cationite in the hydrogen form (H-form) is plac!. Some of the Na+ ions are exchang! for hydrogen ions.
Sodium hydroxide integration with erp systems: real-time resource management has not react! with the ionogenic group of the resin is titrat! with acid. By subtracting the residual concentration hindi directory the initial concentration of sodium hydroxide, the capacity of the cationite can be determin!. Another method for determining the exchange capacity of the ionite is to pass a calcium chloride solution through a layer of resin. The capacity of an anion exchange resin (in the OH-form) through which an acid solution is pass! is determin! in a similar way.
The resin capacity can be measur! in mg-eq/ml (volume) or mg-eq/g (weight). If the capacity is determin! in mg-eq/g (meaning the mass of dry ionite), then, knowing the resin moisture content, it is easy to move to mg-eq/ml.