A versatile filter test system to assess removal efficiency for viruses in aerosols

Type
01A - Journal article
Editors
Editor (Corporation)
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Parent work
Aerosol and Air Quality Research
Special issue
DOI of the original publication
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Series number
Volume
21
Issue / Number
12
Pages / Duration
210224
Patent number
Publisher / Publishing institution
Taiwan Association for Aerosol Research
Place of publication / Event location
Edition
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Abstract
Mitigation measures to reduce indoor transmission of SARS-CoV-2 and other pathogenic microorganisms are urgently needed to combat the current pandemic and to prevent future airborne epidemics or pandemics. Very efficient exhaust filters for nanoparticles down to sizes of only a few nanometers have been available for many years; they are used, for example, in diesel and, more recently, gasoline vehicles to reduce emissions. The size of soot particles emitted by combustion engines, i.e., primary particles and aggregates, includes those of viruses. Therefore, such particle filters should also efficiently remove viruses. This study aimed to design a filter test system with a controlled airflow allowing to aerosolize particles at the aerosol inlet and collect samples before and after the particle filter. As an example, results obtained for the NanoCleaner®, a filter designed to clean cabin air in vehicles, are presented. Validation with soot particles produced with a CAST soot generator revealed a filter efficiency higher than 99.5%. To assess the relevance of the test filter system to measure efficiency for viral particles removal, MS2 bacteriophages, also called Escherichia virus MS2, were used as virus surrogate and aerosolized into the filter test system with the commercially available Emser nebulizer. Filter efficiencies of more than 99% for MS2 bacteriophages were achieved using the NanoCleaner® in the filter test system. Experiments with ceramic wall-flow filters showed similar results. To enlighten the versatility of the filter test system, a typical aircraft cabin air filter was also characterized. The measurements confirmed the high filter efficiency, and in addition, we show a decrease of bacteriophage’s survival on the filter material over 48 h post-exposure. In conclusion, we have established a versatile system that is modular to test any filter system for the efficiency of eliminating MS2 bacteriophages as virus surrogates from air.
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ISBN
ISSN
1680-8584
2071-1409
Language
English
Created during FHNW affiliation
Yes
Strategic action fields FHNW
Publication status
Published
Review
Peer review of the abstract
Open access category
Gold
License
'https://creativecommons.org/licenses/by/4.0/'
Citation
Rüggeberg, T., Milosevic, A., Specht, P., Mayer, A., Frey, J., Petri-Fink, A., Burtscher, H., & Rothen-Rutishauser, B. (2021). A versatile filter test system to assess removal efficiency for viruses in aerosols. Aerosol and Air Quality Research, 21(12), 210224. https://doi.org/10.4209/aaqr.210224