Design and evaluation of a new electrostatic precipitation-based portable low-cost sampler for bioaerosol monitoring

Abstract

The importance of bioaerosols to human and ecosystem health is evident as we tackle the on-going coronavirus pandemic. Understanding the airborne migration of pathogens and the consequent transmission of diseases such as COVID-19 requires an ability to monitor bioaerosols at high spatio-temporal resolution. For such monitoring, there is an immediate need for bioaerosol samplers that are easy to deploy and optimized for downstream analysis. In this study, we introduce a small, inexpensive, low-power, and a low-pressure drop device, called TracB, that integrates low-cost aerosol sensing with bioaerosol sampling using electrostatic precipitation technique. The device was designed for an efficient collection of particles in the size range of 0.01–10 µm, making it suitable for a wide range of downstream microbial analysis. A low-cost particle charger has been integrated with the device to improve the collection efficiency of the sampled particles. The performance of the device was tested with Bacillus thuringiensis var. kurtsaki (Btk) as the biological test organism for different operating conditions. The ability of the device to efficiently collect bio-particles when the charger was oriented parallel to the particle flow was confirmed with computational fluid dynamics simulations. Over 50% of biological and nonbiological test particles were collected in the device when operated with an ionizer and a precipitation electric field of 8 kV/cm. Our results demonstrate the potential of the device to be used as an autonomous unit suitable for long-term air sampling at diverse indoor and outdoor locations. Copyright © 2020 American Association for Aerosol Research.