Experimental characterization of multi-point corona discharge devices for direct ozonization of liquids

Experimental investigations were carried out with the aim of evaluating the ozone generation characteristics of a class of multi-point corona electrodes employed for direct treatment of potable and industrial water. The corona electrodes were supplied from an AC high-voltage generator, 0, …, 25 kV, 5 mA, 50 Hz. The efficiency of ozonization depended on the following factors: (i) number and density of the discharge points of the corona electrode; (ii) gap length between the discharge points and the surface of the liquid; (iii) thickness of the liquid layer; (iv) duration of the exposure to the corona discharge and (v) presence of a dielectric barrier between the collecting electrode and the liquid. Typically, the multi-point corona electrode devices produces more than 9 g of ozone absorbed in 1000 l of water for each 1 kWh of energy provided by the high-voltage power supply. The conclusions of the present research work could guide the design of optimized devices for the direct ozonization of liquids.