Plasma activated water generation in pin-to-plate gas phase DBD-based plasma source for enhanced biochemical activity

Plasma-activated water (PAW) has remarkable biochemical activity owing to the synergistic action of reactive oxygen and nitrogen species. However, optimization of the plasma source is required to facilitate seamless translation of PAW into practical applications. In this paper, a study of PAW generation is conducted to understand the effect of changes in electrode and dielectric material, conductivity of liquid, and gap distance on the resulting biochemical activities while maintaining a consistent plasma discharge in a pin-to-plate gas phase dielectric barrier discharge source. During the bipolar-pulse discharge operation at a voltage of 5 kV and frequency of 20 kHz, a substantial amount of hydroxyl radicals, are produced, reaching a concentration of 108.5 mu M. This was attributed to the erosion of high-voltage electrodes in the PAW system. Despite minimal electrode loss, the generated reactive oxidants effectively eliminate bio-contaminants, as confirmed by a 3-log reduction in E. coli during optimal PAW operation.