Nanosecond-pulsed microbubble plasma reactor for plasma-activated water generation and bacterial inactivation

In this study, a microbubble-enabled plasma reactor driven by a nanosecond-pulsed generator was developed to provide an effective means for transferring highly reactive plasma species into liquids for plasma-activated water (PAW) production. The physicochemical characteristics of PAW at different temperatures were evaluated, and the corresponding antimicrobial effects of PAW against Escherichia coli cells were investigated. Results show that the microbubble-enabled PAW at a lower temperature (10°C) had the highest antimicrobial activity, resulting in a 2.43 ± 1.02-log₁₀ reduction of E. coli in PAW. The excellent energy efficiency of the total reactive oxygen and nitrogen species production in PAW is 10.37 g kW⁻¹ h⁻¹. Overall, this study provides much-needed insights into the microbubble-enabled plasma chemistries for optimizing the biochemical activity of PAW.