How does ammonium removal and regeneration using zeolites work?

Ammonium removal with zeolite works through an ion-exchange process. The zeolite’s structure has exchangeable sodium ions, which are replaced by ammonium ions (NH4+) in wastewater or other sources. Over time, as the zeolite becomes saturated with ammonium, its adsorption capacity decreases. To regenerate the zeolite, a concentrated sodium chloride solution is used. The sodium ions displace the ammonium ions from the zeolite, restoring its ion-exchange capacity. After rinsing out the displaced ammonium and salt, the zeolite can be reused for ammonium removal.