What is the exchange rate of typical sodium ion exchange resin regenerated with 10 lbs of salt per cubic foot?

The exchange rate of typical sodium ion exchange resin is often associated with how much hardness (in grains) can be removed per cubic foot of resin when it is regenerated with a specific quantity of salt. In this case, a regeneration with 10 lbs of salt typically yields an exchange capacity of about 25,000 grains per cubic foot. This figure is derived from established standards in water treatment processes, which indicate that approximately 10 lbs of sodium chloride is sufficient to fully regenerate one cubic foot of a standard softening resin to attain this exchange capacity.

The exchange capacity can vary based on factors such as the specific formulation of the resin, the concentration of the brine used, and system efficiency, but the widely accepted value for commercial softening applications hovers around this number. Therefore, the choice reflecting an exchange rate of 25,000 grains per cubic foot as a result of using 10 lbs of salt is consistent with the expected performance of typical sodium ion exchange resins under normal operating conditions.