Rapid Inactivation of Airborne Bacteria Using Atmospheric Pressure Dielectric Barrier Grating Discharge

• Published in: IEEE transactions on plasma science Vol. 35; no. 5; pp. 1501 - 1510
• Main Authors: Gallagher, M.J., Vaze, N., Gangoli, S., Vasilets, V.N., Gutsol, A.F., Milovanova, T.N., Anandan, S., Murasko, D.M., Fridman, A.A.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-10-2007; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Air cleaners; Air flow; air sterilization; Airborne microorganism; Atmospheric-pressure plasmas; Bacteria; Barriers; Devices; dielectric barrier discharge; Dielectric properties; Dielectrics; Discharge; E coli; Electric discharges; Electrical equipment; Escherichia coli; Exact sciences and technology; Gratings; Inactivation; Laboratories; Microorganisms; nonthermal plasma; Other gas discharges; Physics; Physics of gases, plasmas and electric discharges; Physics of plasmas and electric discharges; Plasma; Plasma devices; Reduction; Surface discharges; Surface treatment; Ventilation; Airborne microorganism; Atmospheric pressure; Dielectric barrier discharge; Sterilization; Theoretical study; Surface treatments; air sterilization; Air; nonthermal plasma; E. coli; Capacitive discharge
• ISSN: 0093-3813; 1939-9375
• DOI: 10.1109/TPS.2007.905209

Dielectric barrier discharge plasma has been known to inactivate many different microorganisms on surfaces when treatment times are on the order of seconds or minutes in duration. In this paper, a unique plasma air cleaning facility was created which combines a dielectric barrier grating discharge (DBGD) with a filterless laboratory-scale ventilation system and is used to treat concentrated bacterial bioaerosol in a moving air stream at air flow rates of 25 L/s. Results indicate that plasma treatment times on the order of milliseconds corresponding to one pass through the DBGD device can achieve 1.5-log reduction in culturable E. coli immediately after contact with plasma and 5-log reduction totally following in the minutes after the plasma treatment. A numerical characterization study was performed to help predict and understand the mechanism of bacteria inactivation in the DBD plasma from a variety of plasma factors.