Photocatalytic ozonation process for degradation of an anthelmintic drug using ceramic coated TiO2 NPs: CFD simulation coupling with kinetic mechanisms

This paper reports numerical usage for modeling and simulation of the mebendazole (MBZ) photocatalytic ozonation in a stirred tank photoreactor by computational fluid dynamics (CFD) method, from mechanistic aspects in the presence of novel method of TiO2 coating ceramic panels. In the first part of the study, TiO2 nanoparticles (NPs) were fixed on the exterior surface of porous ceramic panels by a new modified sol-gel method. The coated surface presented very high stability and durability for 12 runs during a year of the process implementation. The morphological characteristics of the coated and bare panels were scrutinized by SEM and AFM analysis. The evolutional impacts of input parameters such as pH, inlet ozone dosage and initial MBZ concentration on MBZ removal efficiency were experimentally investigated. More than 95% degradation was achieved only after 35 min. In the second section, a numerical study of MBZ photocatalytic ozonation has been evaluated by CFD method. Assessment of this process was investigated from two viewpoints: momentum and mass balances. The experimental results revealed a high amount of MBZ elimination in the aforementioned photoreactor. Moreover, CFD modeling simulated the mechanisms of MBZ photocatalytic ozonation. The obtained results described that MBZ degradation has occurred via the two homogenous and heterogeneous pathways in the presence of (OH)-O-center dot radicals. Briefly, the CFD results confirmed the experimental results from the standpoint of hydrodynamics and various species concentrations. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.