GAC pore structure in Cincinnati during full-scale treatment/reactivation

In order to stay in compliance with recent and upcoming disinfection by-product regulations, many utilities are considering advanced treatment processes such as granular activated carbon (GAC). However, there is a lack of research concerning the full-scale performance of GAC and changes in GAC's pore structure after multiple cycles of water treatment and thermal reactivation. This article examines how the changes in GAC pore structure that occur after successive reactivations influence adsorption of total organic carbon (TOC). The authors show that when implemented prior to chlorination, GAC can proficiently adsorb TOC at full scale. Further, they show that although GAC's extensive internal pore structure is altered, GAC still adsorbs TOC proficiently through as many as six cycles of water treatment and thermal reactivation. As regulations become increasingly strict, many utilities may be interested in the long-term "real-world" effectiveness of GAC for removing TOC.