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

摘要

Volatile organic compounds (VOCs) are readily emitted from furniture and cleaningagents and cause indoor air pollution. In Taiwan, the indoor concentrations of VOCsroughly range from 1 to 10 ppm. There is interest in effectively reducing indoor VOCs’emissions with high efficiency and longtermcontrol techniques, such as the reasonableand low cost control techniques found in UV/TiO2 control systems.This study evaluated the performance of a photoreactorpacked with TiO2/Quartzand ZrO2/Quartz, ZnO/Quartz, initiated by UV irradiation. The synthesized TiO2 photocatalyst was made from commercial TiO2 (Degussa P25)with a solgelprocess. A 14-watt lowpressuremercury lamp produced the incident UV light with a wavelength of254nm. Reactants and products were analyzed quantitatively by gas chromatography witha flame ionization detector (GC/FID). It is important to understand the influence ofoperation parameters, such as concentration, catalyst, and retention time. The inletconcentrations of VOCs varied from 100 to 400 ppm. The results showed that the VOCsconcentration increased and the degradation efficiency decreased at the same retentiontime. The degradation efficiency was 99%, 87%, 54%, and 52% with TiO2/Quartz at 100,200, 300 and 400ppm, respectively. Additionally, the retention time increased anddegradation efficiency increased. The degradation efficiency was 99%, 18 – 35%, and 7 -22 % with TiO2/Quartz, ZrO2/Quartz, and ZnO/Quartz, individually, at retention time0.17 -0.67 min and inlet concentration 100ppm. In accordance with the LangmuirHinshelwood model’s predicted results, the reaction rate constant (kc) was 50.1, 7.2, and3.0 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 obeypseudo firstorder kinetics.