Interaction of water droplets with dielectric barrier discharge plasma

This work studies the interaction of water droplets at different sizes with an atmospheric dielectric barrier discharge (DBD) plasma. The droplet sizes are either less than 1 mm or greater than 1 mm in diameter. The water droplets pass through a 2.5 cm wide and 6 cm long column of DBD plasma and are observed using a high-speed camera and the plasma properties are determined using electrical measurements and optical emission spectroscopy. The treated water droplets are then collected and analyzed for changes in chemical properties such as nitrates, nitrites, H₂O₂ and physical properties like pH and conductivity. The initial observations show that plasma power consumption increases in the presence of droplets, the nitrate concentration increases with an increase in input power, and the pH reduces (acidic) and the conductivity increases after interaction with plasma. The charge of the treated droplets is calculated using electrical properties and larger droplets have significantly more charge than the smaller droplets. Further analysis and measurements are planned to be performed and validated with numerical modeling.