TY - JOUR
T1 - The correlation between photocatalytic oxidation performance and chemical/physical properties of indoor volatile organic compounds
AU - Yu, Kuo Pin
AU - Lee, Grace W.M.
AU - Huang, Wei Ming
AU - Wu, Chihcheng
AU - Yang, Shinhao
N1 - Funding Information:
The authors would like to thank National Science Council of Republic of China for funding this research project.
PY - 2006/1
Y1 - 2006/1
N2 - In this study, six species of volatile organic compounds (VOCs), n-hexane, iso-butanol, toluene, p-xylene, m-xylene, and mesitylene, were selected as the target pollutants to investigate how the photocatalytic oxidation (PCO) performance is related to their physical/chemical properties. The PCO kinetics were well fit by a Langmuir-Hinshelwood (L-H) model for bimolecular surface reaction and competitive adsorption at gas flow rate above 1000 mL min -1 (reaction-controlling region), where the gas-phase mass transfer effect was negligible. The rate constants of PCO for toluene, p-xylene, m-xylene, and mesitylene ranged from 1.22 to 4.00 μmol m-2 s -1, and were proportional to VOC-hydroxyl radical rate constant (kOH). The Langmuir adsorption constants of the four aromatic VOCs investigated and water ranged from 0.95 to 1.35 ppm-1 and from 5.61×10-3 to 1.44×10-3 ppm-1, respectively. A strongly linear positive relationship was found between the reciprocal of the Langmuir adsorption constants of the four aromatic VOCs investigated and Henry's Law constants. Conversely, the reciprocal of Langmuir adsorption constants of water showed a strong negative relationship with Henry's Law constants (in units kPa m3 mol-1) of the four aromatic VOCs investigated. The relationships noted above were not found between different classes of VOCs (n-hexane, iso-butanol, and aromatic VOCs investigated). The percentage of residual intermediates (partially oxidized and incompletely mineralized organic compound from the primary VOCs) decreased as the inlet VOCs concentration decreased.
AB - In this study, six species of volatile organic compounds (VOCs), n-hexane, iso-butanol, toluene, p-xylene, m-xylene, and mesitylene, were selected as the target pollutants to investigate how the photocatalytic oxidation (PCO) performance is related to their physical/chemical properties. The PCO kinetics were well fit by a Langmuir-Hinshelwood (L-H) model for bimolecular surface reaction and competitive adsorption at gas flow rate above 1000 mL min -1 (reaction-controlling region), where the gas-phase mass transfer effect was negligible. The rate constants of PCO for toluene, p-xylene, m-xylene, and mesitylene ranged from 1.22 to 4.00 μmol m-2 s -1, and were proportional to VOC-hydroxyl radical rate constant (kOH). The Langmuir adsorption constants of the four aromatic VOCs investigated and water ranged from 0.95 to 1.35 ppm-1 and from 5.61×10-3 to 1.44×10-3 ppm-1, respectively. A strongly linear positive relationship was found between the reciprocal of the Langmuir adsorption constants of the four aromatic VOCs investigated and Henry's Law constants. Conversely, the reciprocal of Langmuir adsorption constants of water showed a strong negative relationship with Henry's Law constants (in units kPa m3 mol-1) of the four aromatic VOCs investigated. The relationships noted above were not found between different classes of VOCs (n-hexane, iso-butanol, and aromatic VOCs investigated). The percentage of residual intermediates (partially oxidized and incompletely mineralized organic compound from the primary VOCs) decreased as the inlet VOCs concentration decreased.
KW - Aromatic hydrocarbons
KW - CO yield rate
KW - Henry's Law constant
KW - Hydroxyl radical
KW - Langmuir-Hinshelwood model
KW - Photocatalytic rate constant
UR - http://www.scopus.com/inward/record.url?scp=29144496913&partnerID=8YFLogxK
U2 - 10.1016/j.atmosenv.2005.09.045
DO - 10.1016/j.atmosenv.2005.09.045
M3 - Article
AN - SCOPUS:29144496913
SN - 1352-2310
VL - 40
SP - 375
EP - 385
JO - Atmospheric Environment
JF - Atmospheric Environment
IS - 2
ER -