Study on Discharge Characteristics of Needle-plate Electrode Plasma and Physicochemical Properties of Activated Water

Since the reaction process of preparing plasma-activated water by gas-liquid two-phase discharge is extremely complex, the influence of discharge parameters on the physical and chemical properties of plasma-activated water is not clear. Plasma activated water was prepared by self-made needle-plate electrode device. The discharge characteristics of gas-liquid two-phase and the physical and chemical properties of activated water were studied. The results show that with the increase of discharge voltage, the discharge mode of the needle-plate electrode device transits from filamentary discharge to spark discharge, and the discharge power and energy are positively correlated with the voltage. The pH value of the solution decreased with the increase of discharge voltage, and the conductivity and redox potential increased. With the increase of activation time, the changes of these parameters are more significant. When the activation time is 1 min, the pH value decreases rapidly from 6.87 to 3.75, and then the pH value decreases slowly. The conductivity increases from 11 μS/cm to 110 μS/cm, and the redox potential increases significantly from 79 mA to 309 mA.These data have certain reference value in practical applications.