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J Air Waste Manag Assoc

Title:		The effect of ozone on the removal effectiveness of photocatalysis on indoor gaseous biogenic volatile organic compounds
Author(s):		Yu KP; Lee GW; Huang GH;
Address:		"Institute of Environmental and Occupational Health Sciences, National Yang-Ming University, Taipei, Taiwan, Republic of China"
Journal Title:		J Air Waste Manag Assoc
Year:		2010
Volume:		60
Issue:		7
Page Number:		820 - 829
DOI:		10.3155/1047-3289.60.7.820
ISSN/ISBN:		1096-2247 (Print) 1096-2247 (Linking)
Abstract:		"In this study, the degradation of d-limonene by photocatalytic oxidation (PCO) (titanium dioxide [TiO2]/ultraviolet [UV]) and by the combination of PCO and ozone (O3) (TiO2/UV/O3) was investigated to evaluate the enhancement effect of O3. The degradation of d-limonene by UV/O3 was also investigated for comparison. The experiments were conducted with a quartz photoreactor under various gas flow rates (600-1600 mL min(-1)), d-limonene concentrations (0.5-9 parts per million [ppm]), and relative humidity (RH) (20-80%). The d-limonene removal efficiency of TiO2/UV/O3, TiO2/UV, and UV/O3 ranged from 62 to 99%, from 49 to 99%, and from 46 to 75%, respectively. The addition of 120-ppb O3 can enhance the d-limonene removal efficiency of PCO up to 12%. The apparent kinetic parameters (apparent rate constants, kapparent and Langmuir adsorption constants, Kapparent of TiO2/UV and TiO2/UV/O3 reactions obtained from fitting Langmuir-Hinshelwood models are TiO2/UV: kapparent = 1.45 x 10(-3) ppm-m sec(-1), Kapparent = 0.34 ppm(-1); TiO2/ UV/O3: kapparent = 1.83 x 10(-3) ppm-m sec(-1), and Kapparent = 0.35 ppm(-1). When RH was higher than 40%, the residual intermediates yield rates of d-limonene of TiO2/UV/O3, TiO2/UV, and UV/O3 reactions ranged from 0.39 to 0.51 micromol carbon m(-2) sec(-1), 0.56 to 1.96 micromol carbon m(-2) sec(-1), and 157 to 177 micromol carbon m(-3) sec(-1), respectively. In the photocatalytic reaction experiments, the addition of 120-parts per billion (ppb) O3 can reduce the residual intermediates yield rates of d-limonene by up to 1.46 micromol carbon m(-2) sec(-1). These experimental results showed that O3 can enhance the effectiveness of photocatalysis on the removal of d-limonene"
Keywords:		"Air Pollutants/*chemistry Air Pollution, Indoor/*prevention & control Carbon Dioxide Catalysis Cyclohexenes/*chemistry Humidity Limonene Molecular Structure Oxidation-Reduction Ozone/*chemistry Photochemistry/*instrumentation/methods Terpenes/*chemistry V;"
Notes:		"MedlineYu, Kuo-Pin Lee, Grace Whei-may Huang, Guo-Hao eng Research Support, Non-U.S. Gov't 2010/08/05 J Air Waste Manag Assoc. 2010 Jul; 60(7):820-9. doi: 10.3155/1047-3289.60.7.820"