Effect of Microplastics on the Flow-Through Electro-Peroxone Process: A Computational Fluid Dynamics Simulation

Abstract

Current research on advanced oxidation processes often focuses on removing individual organic contaminants, sometimes overlooking the impact of microplastics (MPs) on mass transfer. Real-time and precise monitoring through experimental measurements is challenging. In this study, we used computational fluid dynamics simulations to examine the effect of MPs on mass transfer in a flow-through electro-peroxone process. Our findings revealed that MPs decreased the concentration of hydroxyl radicals at the electrochemical cathode/solution interface. However, there was no significant impact on the concentrations and diffusion pathways of O₃ in the inlet gas phase and hydrogen peroxide on the electrochemical cathode surface. Additionally, the average size of MPs increased from 135.0 to 750.0 μm, and their count rose from 7474 to 10,924 particles/L. This was accompanied by increases in average turbulent kinetic energy and turbulent dissipation rate by 0.027 and 0.018 km²/s², and 0.041 and 0.702 m²/s³, respectively. These changes suggested that the enlargement and increased count of MPs hindered liquid flow, reducing the efficiency of converting gaseous O₃ to aqueous O₃. Consequently, this diminished the removal efficiency of pollutants in the electro-peroxone process. These insights are crucial for developing more efficient advanced oxidation processes for the simultaneous removal of MPs and pollutants.