Inactivation of Escherichia coli, Bacteriophage MS2, and Bacillus Spores under UV/H₂O₂ and UV/Peroxydisulfate Advanced Disinfection Conditions

Abstract

Ultraviolet light (UV) combined with peroxy chemicals, such as H2O2 and peroxydisulfate (PDS), have been considered potentially highly effective disinfection processes. This study investigated the inactivation of Escherichia coli, bacteriophage MS2, and Bacillus subtilis spores as surrogates for pathogens under UV/H2O2 and UV/PDS conditions, with the aim to provide further understanding of UV-based advanced disinfection processes (ADPs). Results showed that one additional log of inactivation of E. coli was achieved with 0.3 mM H2O2 or PDS at 5.2 × 10(-5) Einstein·L(-1) photo fluence (at 254 nm) compared with UV irradiation alone. Addition of H2O2 and PDS greatly enhanced the inactivation rate of MS2 by around 15 folds and 3 folds, respectively, whereas the inactivation of B. subtilis spores was slightly enhanced. Reactive species responsible for the inactivation were identified to be •OH, SO4(·-), and CO3(·-) based on manipulation of solution conditions. The CT value of each reactive species was calculated with respect to each microbial surrogate, which showed that the disinfection efficacy ranked as •OH > SO4(·-) > CO3(·-) ≫ O2(·-)/HO2(·). A comprehensive dynamic model was developed and successfully predicted the inactivation of the microbial surrogates in surface water and wastewater matrices. The concepts of UV-efficiency and EE/O were employed to provide a cost-effective evaluation for UV-based ADPs. Overall, the present study suggests that it will be beneficial to upgrade UV disinfection to UV/H2O2 ADP for the inactivation of viral pathogens.

Hydrogen Peroxide: A Key Chemical for Today's Sustainable Development

“…[41] The addition of H 2 O 2 largely also improves UV disinfection processes.I nt he UV disinfection of surfacew ater and wastewater from am unicipal treatment plant, for instance, the inactivation of Escherichia coli bacteria, Bacilluss ubtilis spores, and MS2 bacteriophage viruses proceeded best when UV irradiation was coupled with optimized doses of H 2 O 2 and peroxydisulfate (PDS,S 2 O 8 2À ). [42] Although UV-only treatment performed well with regardt oEscherichia coli,a ny improvement for H 2 O 2 or PDS was marginal, whereas UV/H 2 O 2 far outperformed UV/ PDS with regard to UV-resistant MS2, and only UV/H 2 O 2 succeeded in deactivating Bacillussubtilis.…”

Microbial electrolytic disinfection process for highly efficient Escherichia coli inactivation

“…Subsequently, the culture was centrifuged at 6000 rpm for 10 minutes to harvest the bacteria which were resuspended in 50 mM Na 2 SO 4 . This step was repeated three times to achieve bacterial suspension without any nutrients and metabolites from the cells [24]. E. coli suspension was stocked in 4 °C for further use.…”

“…In terms of hydrogen peroxide generation, it could be accumulated without of Fe 2+ but it seemed not to contribute to disinfection (Figure 2a) as only approximate 3.5 mg/L H 2 O 2 was detected. It was still far below the level needed for disinfection [24]. Therefore it was concluded that the radical oxidative species (e.g.,…”

Factors affecting contaminant transformation by heat-activated persulfate

“…Peroxydisulfate (or simply persulfate, S2O8 2-) is being increasingly used in advanced oxidation processes for treatment of wastewater and industrial waste, and in situ chemical oxidation (ISCO) for remediation of contaminated soil and groundwater (Huling et al, 2006;Tsitonaki et al, 2010;Deng and Ezyske, 2011;Siegrist et al, 2011;Drzewicz et al, 2012;Ahn et al, 2013;Yang et al, 2014;Sun et al, 2016). In these applications, persulfate is activated into sulfate and hydroxyl radicals (SO4 •and • OH), powerful oxidants that can oxidize a wide range of organic contaminants.…”

“…In these applications, persulfate is activated into sulfate and hydroxyl radicals (SO4 •and • OH), powerful oxidants that can oxidize a wide range of organic contaminants. Common persulfate activators include heat Johnson et al, 2009;Constanza et al, 2010), ultraviolet light (Yang et al, 2014;Sun et al, 2016), dissolved metals and metal oxides (Anipsitakis and Dionysiou, 2004;Ahmad et al, 2010;Sra et al, 2010;Drzewicz et al, 2012;Ahn et al, 2013;Liu et al, 2014), and alkaline solutions (Singh and Venkatarao, 1976;Furman et al, 2010).…”