Evaluation of mass and photon transfer enhancement by an impinging jet atomization photoreactor for photocatalytic degradation of p-nitrophenol

Abstract

In this study, the photocatalytic degradation of p-nitrophenol (PNP) was investigated in a slurry impinging jet atomization reactor and TiO2 nanoparticles have been applied as the photo-catalyst. Formation of the thin leaf-like liquid sheet with high mixing and turbulence intensity due to the collision of two jets, brings a perfect mass transfer. Moreover, the low thickness of the sheet will enhance photon transfer which is an integral factor in UV/TiO2 processes. The impact of different parameters consisting of initial PNP concentration (30−70 mg/L), catalyst loading (0.2−0.8 gr/L) and Reynolds number (15000–31000) on the PNP conversion were investigated in the operating time of 180 min. Based on the results, the optimum experimental condition for the PNP initial concentration of 50 mg/L was 0.5 g/L catalyst loading and Reynolds number of 31,000 with the removal percentage of 55.78 % during 180 min that has been enhanced to 71.91 % by increasing the operation time to 360 min. DLS**Dynamic light scattering analysis has also been conducted for investigation of TiO2 loading effect on particles agglomeration. A pseudo-first-order kinetic model, which is the modified form of Langmuir-Hinshelwood kinetic model, was applied for prediction of p-nitrophenol photocatalytic degradation. A good compatibility between the predicted and experimental data has been observed.