Effects of acidity in electrolyzed ozone water on the ozone decay time

This article presents the synergic effects of the acidity in electrolyzed ozone water (EOW) on the sterilization and the detailed properties of ozone behavior, including the increase in the ozone decay time caused by lowering the pH value of the water. A theoretical model developed for sterilization of microbes by EOW indicates that the main synergic effect of the acidity in EOW is the increase in the ozone decay time at a low pH value, thereby effectively killing endospores of Bacillus atrophaeus, demonstrating a potential for cleanup of a large contaminated area in a very short time, and reinstating the contaminated environment as free from biological agents. The experimental observations agree remarkably well with theoretical results. In general, the ozone concentration decays with a decay time that decreases an increasing concentration of organic contaminants. The ozone decay time is measured for a broad range of physical parameters, including various values of ethanol concentration and different pH values. The decay time increases as the pH value decreases from pH = 8 to pH =3. Particularly, the decay time of ozone increases drastically as the pH value decreases from pH = 6 to pH = 4. Finally, this article presents the decay properties of the ozone concentration in EOW contaminated by broths used in sterilization experiments.