Impact of UV-H₂O₂ advanced oxidation and aging processes on GAC capacity for the removal of cyanobacterial taste and odor compounds

Cyanobacteria and their taste and odor (T&O) compounds are a growing concern in water sources globally. Geosmin and 2-methylisoborneol (MIB) are the most commonly detected T&O compounds associated with cyanobacterial presence in drinking water sources. The use of ultraviolet and hydrogen peroxide (H₂O₂) as an advanced oxidation treatment for T&O control is an emerging technology. However, residual H₂O₂ (>80% of the initial dose) has to be removed from water prior final disinfection. Recently, granular activated carbon (GAC) is used to remove H₂O₂ residual. The objective of this study is to assess the impact of H₂O₂ quenching and aging processes on GAC capacity for the removal of geosmin and MIB. Pilot columns with different types of GAC and presence/absence of H₂O₂ have been used for this study. H₂O₂ removal for the operational period of 6 months has no significant impact on GAC capacity to remove the geosmin and MIB from water.