Generation of Plasma Activated Water by Aeration of Gas Transported from Pin-to-Pin Spark Discharge in Confined Airflow

In recent years, Plasma-Activated Water (PAW) generated using atmospheric pressure plasma has been gradually recognized as having positive effects on plant growth. To facilitate extensive validation and widespread application of these effects, the development of equipment for cost-effectively synthesizing large quantities of clean PAW is necessary. In this study, we developed the Confined-type pin-to-pin spark discharge in Airflow for generation of PAW with Aeration of gas (CAA) system. PAW was generated using both the CAA and the previously developed Open-type pin-to-water-surface spark discharge with Natural dissolution of discharged Gas (OWN) system to compare their reactive oxygen and nitrogen species (RONS) components. As a result, the CAA system generated four times as much NO3- than the OWN system. On the other hand, the power consumption of the CAA system was three-quarters that of the OWN system. Furthermore, analysis revealed that while PAW generated with the OWN system contained Fe and Pt components, PAW generated with the CAA system did not. These results demonstrate that the newly developed CAA system is capable of generating metal-contamination free PAW more cost-effectively.