Generation and biological collection efficiency of MS2 bioaerosol for the evaluation of aerosol filtration devices

Bioaerosol;MS2;Activated Carbon Fiber Cloth (ACFC)

Vargas Herrera, Annia Maria ; Nguyen ; Helen ; Rood ; Mark J.

关键词: Bioaerosol;    MS2;    Activated Carbon Fiber Cloth (ACFC);   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/45639/Annia%20Maria_Vargas%20Herrera.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Exposure to bioaerosol in indoor environments is associated with adverse health effects.There is need to develop control devices to separate bioaerosols from gas streams in heating andventilation systems to protect human health and enhance national security. The goal of thisresearch is to develop an experimental setup to evaluate the virus removal efficiency of anelectrothermally regenerated activated carbon fiber cloth (ACFC) filter. MS2 bacteriophage wasused as a model virus. Three tasks were conducted. The first task involved the development of amodified Liquid Sparging Aerosolizer (LSA) generator, which was fabricated to produce a stablesupply of tested bioaerosol. The second task involved the determination of the biologicalcollection efficiency of the SKC BioSampler for bacteriophage MS2. The BioSampler is used tocharacterize the biological removal efficiency of the ACFC filter by capturing the bioaerosol in aliquid medium before and after the ACFC filter. The biological collection efficiency of theBioSampler was calculated based on the results of infectivity assay. A 100 kDalton membranewas used to collect aerosolized MS2 particles at the inlet of the BioSampler. Infectivity assaywas used to determine the infectious MS2 particles on the membrane filter and in the collectionmedia of the BioSampler. Under 1 slpm (standard liter per minute) (20 °C, 1 atm) flow rate ofthe filter, 6 slpm (20 °C, 1 atm) flow rate of the BioSampler, and 50% relative humidity (RH),the biological collection efficiency calculated based on the results of the infectivity assays was7.9 ± 0.42% based on three independent tests. The third task was to determine the ACFC’sability to physically remove nanometer diameter particles. ACFC was tested with 40 nm and 95nm diameter PSL beads. A particle physical removal of 97 ± 0.07% of the particles wasmeasured based on the difference of the outlet and inlet particle number concentrations.This research comprises the preparatory steps into the development of an indoor airfilteringdevice. A stable bioaerosol generator was built and tested; the physical removalefficiency of the filter and the biological collection efficiency of the BioSampler were quantified.The low biological bioaerosol collection efficiencies found in this research provide anopportunity for future research, which should involve the evaluation of the biological collectionefficiency under variable conditions of RH, flow rate, and viral concentration for differentnanodiameter sized viruses. Based on these results, a more accurate testing of the ACFC’sremoval efficiency for viral particles should be conducted. Finally, electrothermal heatingexperiments must be performed, which will incorporate the evaluation of the amount of electricalpower applied to the ACFC filter and the effect of increased electrical power on the infectivity ofcollected bioaerosols. All these experiments will test the ACFC’s capability to removebioaerosols from airstreams and thus become a potential filter device for air conditioning andventilation (HVAC) systems.