Reagentless-Continuous Flow Method for Determination of Aqueous Ozone with Thin Film Semiconductor and Application to an Advanced Water Treatment Plant

A method without any reagent for the determination of ultra-trace aqueous ozone, utilizing a glass tube-separation process and a thin film semiconductor, is proposed. The glass tube was used as the separator to transfer ozone from water into a gas phase. Ozone was transferred into clean air flowing in the tube and then was continuously monitored at the thin film semiconductor. Signals were proportional to concentration of aqueous ozone more than 5 µ g/L. The relative standard deviation (n = 7) las 3.8 % at 7.6 µ g/L. The interference from hydrogen peroxide, mono-chloramine, and dichloramine, was completely eliminated. The present method was applied to an advanced water treatment pilot-plant incorporating two parallel treatment trains and was examined for its potential for monitoring aqueous ozone in treatment processes.