Photocatalytic degradation of metformin on a rectangular baffled reactor: CFD modeling and validation investigation

Abstract

Solar-irradiated photocatalysis is an advanced oxidation process (AOP) commonly used for water purification due to its excellent potential to break down a diverse range of persistent organic compounds into non-toxic byproducts. Reactor design is crucial in the photocatalysis process's efficiency, effectiveness, and scalability. Computational fluid dynamics (CFD) is an effective tool to study and comprehend reactor designs, reduce system cost, design time, and optimise reactor performance. This investigation focuses on designing and developing a rectangular baffled photocatalytic reactor that can effectively degrade metformin (MTF). The experimental study optimized the value of pH and catalyst dosage for efficient removal. The photoreactor demonstrated an efficiency of 58.14 % and was validated. The CFD results, including velocity profile and mass fraction of metformin, strongly agreed with the experimental results with an R2 value of 0.9826. The combination of various baffle sizes and spacing configurations was modeled and analyzed to develop a rectangular baffled photocatalytic reactor with maximum removal efficiency. The inclusion of baffles increased the flow path, improved mixing and enhanced the degrading efficiency. The investigation findings indicated the highest degradation efficiency of 78.03 % with the seven number of baffles.