LAUSR

Abstract A circulating water electrolysis system was developed to produce highly concentrated O3-dissolved water (ozone water). It enabled the production of 160 and 112 mg/L ozone water in batch and continuous-withdrawal operation, respectively. The ratios of the actual gas-phase O3 concentrations to those calculated from the dissolved O3 concentration using Henry's law at 1 atm were about 0.5, suggesting the supersaturation of ozone water. Once the O3 gas dissolved in the electrolysis cell operated at 0.15 MPa/G, it should have taken time for the ozone water to reach the gas-liquid equilibrium. The electric conductivity of the ozone water increased to 1.2 mS/cm and the formation of ClO2 was observed at the end of the run. The electrophoretic migration of Cl− ions from the catholyte to the ozone water is considered to be the cause of this impurity. The time dependence of the dissolved O3 concentration and the maximum dissolved O3 concentration obtained in the experiment were well reproduced by a circulating water electrolysis simulator.