Study on the Performance Assessment and Kinetic Characteristics of Homogeneous and Heterogeneous Photocatalyst for Indoor Volatile Organic 2 Compounds Removal. Comment: According to style guide.

摘要

Volatile organic compounds (VOCs) are readily emitted from furniture and cleaning agents and cause indoor air pollution. In Taiwan, the indoor concentrations of VOCs roughly range from 1 to 10 ppm. There is interest in effectively reducing indoor VOCs’ emissions with high efficiency and longterm control techniques, such as the reasonable and low cost control techniques found in UV/TiO2 control systems. This study evaluated the performance of a photoreactor packed with TiO2/Quartz and ZrO2/Quartz, ZnO/Quartz, initiated by UV irradiation. The synthesized TiO2 photo catalyst was made from commercial TiO2 (Degussa P25) with a solgel process. A 14-watt lowpressure mercury lamp produced the incident UV light with a wavelength of 254nm. Reactants and products were analyzed quantitatively by gas chromatography with a flame ionization detector (GC/FID). It is important to understand the influence of operation parameters, such as concentration, catalyst, and retention time. The inlet concentrations of VOCs varied from 100 to 400 ppm. The results showed that the VOCs concentration increased and the degradation efficiency decreased at the same retention time. The degradation efficiency was 99%, 87%, 54%, and 52% with TiO2/Quartz at 100, 200, 300 and 400ppm, respectively. Additionally, the retention time increased and degradation efficiency increased. The degradation efficiency was 99%, 18 – 35%, and 7 - 22 % with TiO2/Quartz, ZrO2/Quartz, and ZnO/Quartz, individually, at retention time 0.17 -0.67 min and inlet concentration 100ppm. In accordance with the Langmuir Hinshelwood model’s predicted results, the reaction rate constant (kc) was 50.1, 7.2, and 3.0 ppm/min with TiO2/Quartz, ZrO2/Quartz, and ZnO/Quartz, respectively. In contrast, individually the previous catalyst revealed that the adsorption equilibrium constant (K) was 10.0, 21.9, and 2.4 ppm1. The photoreaction rate of VOCs was also found to obey pseudo first order kinetics.