Enhancing photocatalytic degradation: A comprehensive study on radiation field and photon distribution in concentric...

This study aimed to quantify photon absorption and optimize photocatalytic degradation of oxytetracycline (OTC) in a concentric annular photoreactor. Radiometric measurements were combined with 3D Computational Fluid Dynamics (CFD) simulations, validated against laboratory data. Mass and energy balance models showed excellent agreement with experiments (error <5%), enabling estimation of total transmitted, scattered, and backscattered photons. Results revealed a non-uniform UVC photon distribution, with photon flux concentrated near the lamp and decreasing radially, while catalyst concentration had negligible influence on photon transport. These findings indicate that photon availability, rather than catalyst loading, is the primary limiting factor in photocatalytic efficiency. Evaluation of a spiral reactor design demonstrated improved photon distribution and enhanced OTC degradation efficiency, confirming that reactor design significantly influences light utilization. Therefore, this work highlights the novelty of integrating validated CFD modeling with reactor geometry optimization to advance photocatalytic treatment of emerging contaminants.