Experimental study of the disinfection performance of a 222-nm Far-UVC upper-room system on airborne microorganisms in a full-scale chamber
Building and Environment
; 236, 2023.
Article
in English
| Scopus | ID: covidwho-2305491
ABSTRACT
222-nm Far-UVC light is an emerging and promising tool for rapidly inactivating airborne pathogens. In this study, we experimentally evaluated the performance of a 222-nm Far-UVC upper-room disinfection system with a 15 W Far-UVC lamp in a full-scale chamber (11.9 m3). One gram-positive bacteria, namely Staphylococcus epidermidis and two gram-negative bacteria, namely Escherichia coli and Salmonella enterica were selected for the experiments. The aerosolized bacteria were injected into the chamber and exposed to 222-nm Far-UVC light. The first-order decay rates of indoor bioaerosols concentration with and without Far-UVC treatment were estimated. According to the results, the 222-nm Far-UVC induced decay rates of three bacteria were 0.0611 ± 0.003, 0.409 ± 0.048, and 0.474 ± 0.015 min−1, respectively. Besides, the UV susceptibility constants (Z-values) of these three bacteria were estimated as 0.157, 0.974, and 1.18 m2/J, respectively. The gram-positive bacteria, S. epidermidis, showed higher resistance to Far-UVC light as compared to the gram-negative bacteria, E. coli and S. enterica. In addition, a case study on airborne SARS-CoV-2 indoor transmission was simulated, and the infection risk of SARS-CoV-2 was compared using the Far-UVC and enhanced ventilation approaches. The results showed that both UV inactivation and ventilation approaches can significantly reduce the infection risk. More importantly, the Far-UVC may be a feasible and sustainable solution for reducing infection risk and improving indoor air quality. © 2023 Elsevier Ltd
222-nm Far-UVC; Airborne microorganisms; Infection risk; Upper-room germicidal irradiation; UV susceptibility constants; Air quality; Coronavirus; Decay (organic); Disinfection; Indoor air pollution; Salmonella; Decay rate; Gram-negative bacteria; Gram-positive bacterium; Performance; Room systems; UV susceptibility constant; Escherichia coli
Full text:
Available
Collection:
Databases of international organizations
Database:
Scopus
Language:
English
Journal:
Building and Environment
Year:
2023
Document Type:
Article
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