TITLE:
Influence of Reactive Volatile Organic Compounds on Ozone Production in Houston-Galveston-Brazoria Area
AUTHORS:
Samarita Sarker, Raghava R. Kommalapati, Ziaul Huque
KEYWORDS:
Comprehensive Air Quality Model with Extensions (CAMx), Nitrogen Oxides (NOx) Ozone (O3), Volatile Organic Compound (VOC), Correlation of VOC with O3
JOURNAL NAME:
Journal of Environmental Protection,
Vol.6 No.4,
April
27,
2015
ABSTRACT: Secondary
pollutant ozone (O3) formation in a particular area is often
influenced by various factors. Source of emissions is one of the factors. In
south east Texas, Houston-Galveston-Brazoria (HGB) is a marginal non-attainment
area for ozone (O3). A summer episode of May 28 to July 2, 2006 is
simulated using Comprehensive Air Quality Model with extensions (CAMx). During
this period O3 concentration in HGB often exceeds the National
Ambient Air Quality Standards (NAAQS) 0.075 ppm of average 8 hour O3 concentration. HGB area has numerous point sources. Various studies found that
some specific volatile organic compounds are very reactive in atmosphere. The
objective of this study is to analyze the influence of volatile organic
compounds present in point source emissions on the air quality of HGB area. For
this purpose ozone sensitivity for HGB area is analyzed by the ratio of
hydrogen peroxides (H2O2) to nitric acid (HNO3).
HGB area is found NOx limited but reactive VOCs are found to be influential
too. From (1-4 June, 2006) maximum O3 concentration was found on
weekend, June 3. VOCs such as Acetaldehyde (ALD2), Formaldehyde
(FORM) and Alkane (ETHA) showed good correlation with O3 concentrations on that day. In addition, Peroxyacetyl nitrate (PAN) formation
was found correlated to higher ozone production. Criteria pollutant Sulfur
dioxide (SO2) was found to influence the ALD2 and ETHA
concentrations, and thus indirectly influenced O3 production.