What is the method of resin renewal called?

The correct term for the method of resin renewal in water treatment is regeneration. This process refers specifically to the restoration of the ion exchange capacity of the resin beads that have been exhausted after extended use. During regeneration, a concentrated solution of salt or other chemical is typically used to displace the ions that have accumulated on the resin, allowing it to regain its effectiveness in removing impurities from water.

Regeneration is essential to maintain the efficiency of ion exchange systems, such as water softeners, which rely on resin to remove hardness-causing ions like calcium and magnesium. This method ensures that the resin can continue to perform its function over time, minimizing the need for complete replacement of the resin material itself.

In contrast, terms like reactivation, replacement, and rejuvenation may suggest other processes that are not specifically aligned with the standard procedure for restoring ion exchange resins. Reactivation might pertain to the revival of spent granules, replacement suggests a complete swap of the resin, and rejuvenation doesn't adequately capture the specific chemical process involved in restoring the ion exchange capability of resin.