Susceptibility constants of airborne bacteria to dielectric barrier discharge for antibacterial performance evaluation

Highlights: ► We characterized DBD by measuring concentrations of reactive species and ions. ► The inactivation efficiency was deduced using aerosol- and colony-counting methods. ► Susceptibility constant (Z) was introduced for performance evaluation of DBD. ► Modified Z was suggested for evaluation of DBD reactors of different sizes. ► Our methodology will be used for design optimization and performance evaluation. -- Abstract: Dielectric barrier discharge (DBD) is a promising method to remove contaminant bioaerosols. The collection efficiency of a DBD reactor is an important factor for determining a reactor's removal efficiency. Without considering collection, simply defining the inactivation efficiency based on colony counting numbers for DBD as on and off may lead to overestimation of the inactivation efficiency of the DBD reactor. One-pass removal tests of bioaerosols were carried out to deduce the inactivation efficiency of the DBD reactor using both aerosol- and colony-counting methods. Our DBD reactor showed good performance for removing test bioaerosols for an applied voltage of 7.5 kV and a residence time of 0.24 s, with ηCFU, ηNumber, and ηInactivation values of 94%, 64%, and 83%, respectively. Additionally, we introduce the susceptibility constant of bioaerosols to DBD as a quantitative parameter for the performance evaluation of a DBD reactor. The modified susceptibility constant, which is the ratio of the susceptibility constant to the volume of the plasma reactor, has been successfully demonstrated for the performance evaluation of different sized DBD reactors under different DBD operating conditions. Our methodology will be used for design optimization, performance evaluation, and prediction of power consumption of DBD for industrial applications