THE COMPARISON OF OXIDATION EFFICIENCY OF REACTIVE OXYGEN SPECIES (ROS): PILOT SCALE OF MICROBUBBLE TECHNOLOGIES WITH OXYGEN CONCENTRATION

Abstract

The objective of this study is to assess and compare the effectiveness of an oxidizing agent. Within the field of advanced oxidation processes (AOPs), ozone, a highly reactive gas, generates reactive oxygen species (ROS) as byproducts through chemical reactions. The study employed a dielectric barrier discharge (DBD) plasma generator to produce ozone gas. This study was carried out under different gas source conditions, including both air and oxygen. Additionally, the ROS produced as byproducts from the interaction between ozone gas and water were measured using oxidation-reduction potential (ORP) values. The ORP values exhibit strong foundational attributes for both ozone dissolution and ROS oxidation efficiency. To extend the interaction duration between ozone gas and water, a stone diffuser was utilized to introduce ozone gas into the water. This mechanism resulted in the creation of ozone microbubbles through a process known as cavitation. The results illustrate a positive relationship between the flow rate and ozone yield. This trend reached its highpoint with the highest observed ozone concentrations approximately 14.11 mg/L for oxygen and 4.55 mg/L for air both achieved at a flow rate of 11 L/min. Furthermore, the highest ozone concentrations were recorded at 15.17 mg/L for oxygen and 12.59 mg/L for air after a 10 min discharge period. Interestingly, ozone generated from oxygen feed gas exhibited a higher concentration yield than that from air feed gas. Moreover, the ORP value displayed a continuous increase with longer treatment times, eventually stabilizing at around the 15 min. This pattern corresponded to the water reaching its highest the ORP values approximately 821 mV for oxygen and 569 mV for air. In summary, this study emphasizes the potential benefits of utilizing ozone as an effective oxidant in both gaseous (ozone gas) and liquid (ROS) phases. It especially emphasizes the essential role played by the generation of ozone and ROS from an oxygen-fed gas source. Moreover, it highlights the significance of maintaining an optimal flow rate of 11 L/min and a discharge duration of 10 min for achieving the highest ozone concentration. Similarly, a treatment time of 15 min for the liquid phase is recommended to maximize ORP values. Both of these values indicate the highest potential advantages for producing an effective oxidant.