Plasma Acid Production in a Gliding Arc Plasmatron

Plasma acid is an acidic solution simply produced from water and a carrier gas in an electrical discharge. These produced solutions are of high value for biological decontamination and industrial pollutant abatement applications. While several electrical discharges have been shown to produce plasma acid, the subject of this study is the gliding arc plasmatron, a rotating gliding arc discharge. Air and oxygen were used as gases to carry for distilled water through the discharge, and pH and conductivity of the resulting solution was measured. Consistent with other studies of plasma acid, solutions with a lower pH were obtained with air at the carrier gas than with oxygen, and the conductivity increased appropriately with the pH decrease. Other studies noted a transient change in plasma acid after treatment in an air carrier gas, whereas in this study, oxygen also was observed to temporally decrease the acidity over several days.