Impact of Cold Atmospheric Plasma Treatment Duration on Distilled Water Physicochemical Characteristics

Abstract

A thrilling technological advance is plasma-activated water, or PAW, with potential applications in various fields. Nevertheless, additional research is required for a comprehensive understanding of its physicochemical properties and how they can be optimized for specific applications. The current study employed different analytical methods to examine the effects of varying exposure durations of PAW generated using air as a working gas (ranging from 0 to 15 minutes) on the temperature, electric conductivity (EC), contact angle, pH, H2O2, and NO−2 measurements of PAW. Additionally, the study explored the effects of PAW storage at a temperature of -20°C and the stability of pH, hydrogen peroxide (H2O2), and nitrite anion (NO-2) levels over a period of up to 20 days after its production. The results clarified that the PAW contains reactive oxygen (ROS) and nitrogen species (RNS), specifically H2O2, and NO−2, which can be stored for at least over 20 days at -20°C without significant changes in concentration. Plasma treatment increases the conductivity of water over time, and the pH decreases with prolonged exposure. The study provides valuable insights into the diverse applications of PAW in distinct research and industrial domains.