Phenol degradation of waste and stormwater on a flat plate photocatalytic reactor with TiO2 on glass slide: An experimental and modelling investigation

Abstract

Heterogeneous photocatalytic oxidation process using TiO2 (titanium dioxide) and UV light is a promising method to degrade a wide variety of recalcitrant organic substances such as phenol, pesticides, herbicides, etc. from waste and stormwater. Due to lack of suitable computational fluid dynamics (CFD) model, the industrial-scale application of this technique poses a few challenges indicating the need to clearly understand the hydrodynamic behaviour of the photocatalytic system and investigate the ways of improving their performance. Inadequate mixing and turbulence in a fixed photocatalytic reactor limit the performance of the reactor in terms of pollutant mass transport to the catalyst surface and pollutant degradation. In this study, a 3D flat plate photocatalytic reactor was designed and developed, and numerically analysed using CFD code FLUENT to investigate the performance of the reactor. The CFD modelling results were validated against the experimental data at various flow conditions. The CFD results including velocity and phenol concentration was found in strong agreement with the experimental results with R2 value of 0.998. The experimental results shows that the phenol degradation was 85.5% when the irradiation was 70.6 Wm−2 and initial concentration of phenol was 20 PPM The experimental results also show that the phenol degradation increases with the increase of irradiation but decreases with the increase of initial concentration. The results show that phenol degradation of the reactor decreases with the increase in flow rate as expected. The CFD model can accurately predict the velocity and the concentration of phenol at different flow rates.