Effects of water matrix on virus inactivation using common virucidal techniques for condensate urine disinfection

Abstract

Three common virucidal techniques (chlorine, UV and UV/TiO2) were applied to inactivate virus (MS2 and Phi X174) in condensate water after the evaporation of source-separated urine for reclaimed water. The inactivation efficiencies were compared with the results of previous studies, with the emphasis on the analysis of water matrix effects. Results showed that all virus inactivation in condensate water were lower than the control (in sterilized DI water). As for UV/TiO2 disinfection, both nitrate and ammonia nitrogen could promote slightly viral inactivation, while the inhibition by urea was dominant. Similarly, ammonia nitrogen had greater impacts on chlorine disinfection than urea and nitrate. In contrast, all water matrices (urea, nitrate and ammonia nitrogen) had little influence on UV disinfection. Based on the findings in this study, UV disinfection could be recommended for disinfecting the reclaimed water from the evaporation of source-separated urine.

Disinfection Processes

“…Resistance of E. coli O157:H7 strain 961019 and ATCC 25922 strain to UV radiation increased after freezing and thawing; the ATCC 29522 strain was generally more resistant, but the resistance of the O157:H7 strain 961019 strain increased with increasing freeze-thaw cycles (Gao and Leung, 2015). Zuo, Chu, and Hu (2015) found that ammonia, nitrate and nitrite has little effect on disinfection of MS2 and X174 coliphage in condensate water after the evaporation of source-separated urine for reclaimed water, while disinfection by UV/TiO2 was inhibited by urea and promoted slightly by nitrate and ammonia.…”

Review on heterogeneous photocatalytic disinfection of waterborne, airborne, and foodborne viruses: Can we win against pathogenic viruses?

“…In another research, Zuo et al used Phi X174 and MS2 viruses as viral disinfection models [78] . They applied three disinfection procedures (UV, chlorine, and UV/TiO 2 ) to eliminate the abovementioned viruses.…”

“… Photocatalyst Virus Operational condition Light source Disinfection efficiency Type of virus Ref. Catalystloading(mg/L) Virus level(PFU*/mL) TiO 2 Phage MS2 1000 6 × 10 4 UV 2.8-log in 65 min waterborne [41] TiO 2 Phage MS2 1000 6 × 10 5 18 W BLB* lamp 1.8-log in 180 min waterborne [61] TiO 2 Bacteriophage Qβ 1000 1 × 10 6 UV lamp 3.5-log in 2 min waterborne [64] TiO 2 Phage f2 1000 10 10 –10 11 6 W black light lamp 6-log in 15 min waterborne [78] TiO 2 Influenza virus No data 4.0 × 10 8 1 mW black light Eliminated in 5 min airborne [83] TiO 2 Influenza virus No data 0.0 or 0.1 mg ml −1 20 W black light 4-log in a short irradiation time airborne [84] TiO 2 H1N1 No data No data UV-LED lamp Eliminated in 7 min airborne [85] TiO 2 MNV-1 No data No data UV lamp 3.2-log in 10 min food...…”

Identification of the inactivating factors and mechanisms exerted on MS2 coliphage in concentrated synthetic urine

“…In non-hydrolyzed synthetic urine, which lacks ammonia, MS2 inactivation is consequently very slow. Zuo et al (2015) reported a protective effect of (non-hydrolyzed) concentrated urine constituents against common virucidal techniques (chlorine, UV and UV/TiO 2 ). It has been reported that osmotic pressure is one of the inactivating factors for viruses, but the susceptibility to salinity depends on virus type.…”