北京
环境科学
环境化学
煤燃烧产物
臭氧
污染
汽油
空气污染
氮氧化物
柴油
挥发性有机化合物
燃烧
环境工程
中国
化学
气象学
地理
生物
有机化学
考古
生态学
作者
Yafei Liu,Mengdi Song,Xingang Liu,Yuepeng Zhang,Lirong Hui,Liuwei Kong,Yingying Zhang,Chen Zhang,Qian Yu,Junling An,Depeng Ma,Qinwen Tan,Miao Feng
标识
DOI:10.1016/j.envpol.2019.113599
摘要
Concentrations of 99 volatile organic compounds (VOCs) were continuously measured online at an urban site in Beijing, China, in January, April, July, and October 2016. Characterization and sources of VOCs and their related changes during days with heavy ozone (O3) pollution were analysed. The total observed concentration of VOCs (TVOCs) was 44.0 ± 28.9 ppbv. The VOC pollution level has decreased in Beijing but remains higher than in other Chinese cities. Alkanes comprised the highest proportion among seven major sampled VOC groups. The concentrations and sources of ambient VOCs showed obvious temporal variations. Six emission sources were identified by the positive matrix factorization (PMF), including biomass burning, coal combustion, gasoline vehicles, diesel vehicles, solvent usage, and biogenic + secondary emissions. The combustion source was the key control factor for VOC reduction in Beijing. From the potential source contribution function (PSCF) and concentration-weighted trajectory (CWT) model, Beijing, Tianjin, Hebei, Shanxi, Inner Mongolia, Shandong, and Henan were identified as major potential source regions of ambient VOCs. O3 formation was sensitive to VOCs in Beijing according to the VOC/NOx ratio (ppbC/ppbv, 8:1 threshold). High- and low-O3 days in July were identified, and high O3 levels were due to both enhanced VOC emission levels and meteorological conditions favourable to the production of O3. These findings provide evidence that the fuel combustion and regional transport have a great impact on concentrations and sources of VOCs in urban Beijing.
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