Effect of Calcium on Thermal Regeneration of GAC

Calcium commonly accumulates on granular activated carbon (GAC), and when it is chelated by natural organic matter (NOM), it is drawn into the pores of the GAC. Internally loaded calcium greatly catalyzes regeneration reactions, leading to accelerated internal mass loss. Optimal conditions for the regeneration of a GAC not loaded with calcium lead to severe overregeneration if applied to a calcium‐loaded GAC. The pore structure and capacity of the GAC are adversely affected by this overregeneration. The authors of this article found that calcium‐loaded GACs could be regenerated to yield a GAC with the properties of the virgin GAC by reducing the regeneration time or temperature.