Characterization and source identification of ambient volatile organic compounds (VOCs) in a heavy pollution episode in Beijing, China
نویسندگان
چکیده
102 ambient VOC species were measured online by a gas chromatography-mass spectrometry/flame ionization detector (GC/MS-FID) at an urban site in Beijing during a heavy pollution episode in December 2014. VOC sources were identified by correlation analysis of particular species pairs. The interspecies correlations of benzene-acetylene, toluene-acetylene, isobutane-propane and ethane-propane were analyzed by calculating the correlation coefficients. Major sources were concluded by comparing the linear regression slopes with previous studies. Alkanes provided the largest contribution to ambient VOCs, accounting for 38.9% of total VOCs; followed by alkenes and alkynes, accounting for 28.7% and 11.8%, respectively. The most abundant VOC species include ethene, ethane, acetylene and propane, with hourly average mixing ratios of 14.85, 14.47, 9.69 and 7.27 ppbv, respectively. VOC groups including alkanes, alkenes and alkynes, and the most abundant species followed a similar pattern of average diurnal variation. VOC mixing ratios decreased after sunrise and reached a minimum value at noon (12:00–14:00), then increased in the afternoon and reached a peak value at night (22:00–23:00). This likely resulted from a descending boundary layer at night and possible night emissions. There was no pronounced diurnal variation in oxygenated VOCs (OVOCs). LPG-related sources and combustion sources were major VOC sources in this heavy pollution episode.
منابع مشابه
Atmospheric Volatile Organic Compounds in a Typical Urban Area of Beijing: Pollution Characterization, Health Risk Assessment and Source Apportionment
Atmospheric volatile organic compounds (VOCs) measurement was carried out using gas chromatography-flame ionization detector (GC-FID) technique (Airmo VOCs online analyzer) in a typical urban area in Beijing from April 2014 to January 2015. Ambient levels, variation characteristics and influential factors contributing to the formation of near-ground-ozone and secondary organic aerosols as well ...
متن کاملSource Apportionment Of High Reactive Volatile Organic Compounds In a Region With The Massive Hydrocarbon Processing Industries
In the Persian Gulf region, conditions are highly favorable for ozone air pollution and the region is a hot spot of photochemical smog. The vast activities in processing oil and gas play a major role in it. It was found that the elevated concentrations of reactive hydrocarbons co-emitted with nitrogen oxides from Hydrocarbon Processing facilities lead to substantial ozone production. South Pars...
متن کاملCharacterization of ambient volatile organic compounds and their sources in Beijing, before, during, and after Asia-Pacific Economic Cooperation China 2014
Ambient volatile organic compounds (VOCs) were measured using an online system, gas chromatography– mass spectrometry/flame ionization detector (GC-MS/FID), in Beijing, China, before, during, and after Asia-Pacific Economic Cooperation (APEC) China 2014, when stringent air quality control measures were implemented. Positive matrix factorization (PMF) was applied to identify the major VOC contri...
متن کاملA temporally and spatially resolved validation of emission inventories by measurements of ambient volatile organic compounds in Beijing, China
Understanding the sources of volatile organic compounds (VOCs) is essential for ground-level ozone and secondary organic aerosol (SOA) abatement measures. We made VOC measurements at 27 sites and online observations at an urban site in Beijing from July 2009 to January 2012. Based on these measurement data, we determined the spatial and temporal distribution of VOCs, estimated their annual emis...
متن کاملVehicular volatile organic compounds losses due to refueling and diurnal process in China: 2010-2050.
Volatile organic compounds (VOCs) are crucial to control air pollution in major Chinese cities since VOCs are the dominant factor influencing ambient ozone level, and also an important precursor of secondary organic aerosols. Vehicular evaporative emissions have become a major and growing source of VOC emissions in China. This study consists of lab tests, technology evaluation, emissions modeli...
متن کامل