Filtration of bioaerosols using a granular metallic filter with micrometer-sized collectors

Experimental studies with granular bed filters composed of sized metallic granules have demonstrated their use in aerosol filtration. However, the effectiveness of metallic membrane filters against bioaerosols has not been established. In this work, the filtration efficiency and filter quality of these filters against airborne B. subtilis endospore and MS2 virus were determined as a function of face velocity and loading time. In experiments, a physical removal efficiency greater than 99.9% and a viable removal efficiency greater than 99.999% were observed for both bacterial spore and viral aerosols. A lower face velocity produced both higher collection efficiency and filter quality for virus but was not a statistically significant factor for spore filtration. Although the filter had high filtration efficiency of the test bioaerosols, its high pressure drop resulted in a low filter quality (0.25-0.75∈∈kPa-1). Overall, filters with micrometer-sized collectors capture bioaerosols effectively but their applications in aerosol filtration may be limited by their high pressure drop.