Power dependence of reactive species generation in a water falling film dielectric barrier discharge system

The short-lived and long-lived reactive species generated in plasma-liquid interactions determine their potential applications in wastewater purification and plant growth stimulation. In this work, plasma-generated reactive species including hydroxyl radicals (center dot OH), hydrogen peroxide (H2O2), ozone (O3), hydronium (H3O+), and ni-trate (NO3-) were quantified in a water falling film dielectric barrier discharge system. The reaction kinetics of short-lived center dot OH were analyzed based on the quantification of center dot OH and degradation of salicylic acid, focusing on the contribution and utilization of center dot OH. The interconversion of center dot OH with H2O2 and O3 was also calculated. The accumulation rates of H3O+ and NO3- indicated the potential of this dielectric barrier discharge system in sustainable fertilizer production. In addition, the toxicity prediction of salicylic acid degradation intermediates and the cultivation of soybean seeds verified the feasibility of plasma-liquid interactions in organic wastewater recycling.