Impact of UV–H₂O₂ Advanced Oxidation and Aging Processes on GAC Capacity for the Removal of Cyanobacterial Taste and Odor Compounds

Abstract

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.

Geosmin and 2-methylisoborneol removal in drinking water treatment

“…Hydrogen peroxide was able to oxidize up to the odor threshold with the maximum dose (1.5 mg/l), when using only the conventional treatment without the application of polymer in the treatment. However, any residual oxidant must be fully removed before the disinfection process, as it exerts a strong chlorine demand and could compromise final disinfection, leading to insufficient chlorine residual within the distribution system (Zamyadi et al 2015b). Xu et al (2019) found that the concentration of 2-MIB decreased with the application of doses between 3.0 and 20.0 mg/l H 2 O 2 after 8 h of reaction, showing that the capacity of H 2 O 2 to eliminate 2-MIB was greater than that of CuSO 4 and KMnO 4 .…”

“…GSM and 2-MIB are compounds that are difficult to remove with conventional water treatment processes, such as coagulation, sedimentation, and filtration; only advanced water treatment processes can be considered as alternative methods to remove GSM and 2-MIB. The processes reported by different authors include oxidation (Park et al 2006), adsorption of activated carbon (Cook et al 2001;Zamyadi et al 2015a;Bong et al 2021), nanofiltration (Dixon et al 2011), and ultraviolet rays with H 2 O 2 (or TiO 2 ) (Rosenfeldt et al 2005;Zamyadi et al 2015b).…”

Monitoring, Managing, and Communicating Risk of Harmful Algal Blooms (HABs) in Recreational Resources across Canada

“… 6 , 7 HABs affect drinking water and wastewater treatment plants by requiring additional pre-treatment or treatment activity; or in extreme cases, by plant closures as a result of treatment failure. 8 – 10 …”

“…6,7 HABs affect drinking water and wastewater treatment plants by requiring additional pre-treatment or treatment activity; or in extreme cases, by plant closures as a result of treatment failure. [8][9][10] Within freshwaters, cyanobacteria (also termed blue-green algae), are a major concern. Although blooms have been reported under a broad range of environments, 11 cyanobacteria are most likely to proliferate under warm, calm, and nutrientrich conditions.…”

Integration of aerobic granulation and UV/H2O2 processes in a continuous flow system for the degradation of sulfolane in contaminated water

“…24 Furthermore, it can react with chlorine, if chlorine is used as disinfectant in downstream process, compromising disinfection before distribution and increasing costs. 25 Therefore, management of H 2 O 2 residual was also investigated in order to establish a more efficient and effective integrated technology for potential field application of sulfolane groundwater remediations. system.…”