Influence of Temperature on Plasma Chemistry of the Plasma-Activated Water: A Numerical Study

Plasma-activated water (PAW) is produced through an electrically driven plasma-chemical process. Numerous references confirm that the composition of PAW is sensitive to the parameters such as voltage, gap distance, and temperature. In order to advance the application of PAW, this paper focuses on investigating the impact of temperature on the reactive species in both gaseous and aqueous chemistry in a plasma reactor. A comprehensive model is developed to examine the treatment of deionized water using a dielectric barrier discharge (DBD) plasma reactor, while varying the temperature from 10 °C to 90 °C. The results reveal that as the temperature increases, the concentration of short-lived species in the gas phase, including OH, O, and O2(1Δg), increase. Conversely, the concentration of species such as O3, H2O2, N2O5, and HO2NO2 decrease as a result of decomposition reactions and reactions with the aforementioned short-lived species. Furthermore, the behavior of aqueous chemistry differs from that of the gaseous species, with only N2Oaq, O3aq, and NO3aq− achieving high levels of densities. Within the liquid phase, OHaq emerges as an important species, influencing the densities of H2O2aq, NO2aq, and NO3aq−. It is found that high temperatures decrease the pH value of the liquid, subsequently impacting the densities of weak acids and their conjugate ions. These findings contribute to a deeper understanding of PAW preparation, benefiting its development for future applications.