Photocatalytic ceramic membrane: Effect of the illumination intensity and distribution
Shuyana A. Heredia Deba, B.A. Wols, Doekle Yntema, Rob G. H. Lammertink
Abstract
The principles and application of heterogeneous photocatalytic processes have gained wide attention, especially to the effectiveness of the process. In this work a mono and a multi-LED lamp are used to study the impact of the UV light intensity and distribution on the semiconductor surface during the degradation of organic compounds in water. A well-defined scan of the electromagnetic radiation profile on the surface of the membrane was obtained and evaluated. Comparing two lamp configurations with a total photon flux of 210 W.m−2 and using a filtration rate of 9.7 L.m−2.h−1, resulted in 20 % more degradation for the most homogeneous light distribution. Furthermore, the reaction rate relation to the photon flux was also studied, with a surface reaction model that includes possible mass transfer limitations. The surface reaction constant increased linearly with the irradiation intensity for the complete studied range [50 to 550 W.m−2] for the most homogeneous illumination distribution. A less uniform distribution resulted in a less than proportional reaction rate constant with respect to the incident photon flux between 100 and 210 W.m−2. This work adds valuable information to the photocatalysis field to improve the light efficiency in a photoreactor to enhance the degradation of pollutants.