An investigation into the role of VOCs in SOA and ozone production in Beijing, China

Li, Qianqian; Su, Guoshao; Li, Chuanqi; Liu, Pengfei; Zhao, Xiaoxi; Zhang, Chenglong; Sun, Xingming; Mu, Yujing; Wu, Mingge; Wang, Qingliang; Sun, Bohua

doi:10.1016/j.scitotenv.2020.137536

Cited by 161 publications

(67 citation statements)

References 61 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Beijing is a megacity (population of 21.4 million) with an atmospheric reactive VOC mix with both biogenic and anthropogenic influences (e.g. Li et al, 2020). Mean diurnal cycles of ozone, NO, and isoprene and a range of gasand aerosol-phase isoprene oxidation products measured at a city-centre site in summer 2017 (Shi et al, 2019) are shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

“…Both are tracers for non-NOdriven chemistry. While 2-methyltetrol-OS is formed via the ISOPOO + HO 2 IEPOX pathway (Paulot et al, 2009;Surratt et al, 2010;Lin et al, 2012), 2-MGA-OS (Lin et al, 2013) is formed from the OH-initiated oxidation of MPAN (peroxymethacrylic nitric anhydride) (Kjaergaard et al, 2012;Nguyen et al, 2015a), with further oxidation leading to 2-MGA (Surratt et al, 2010;Chan et al, 2010;Nguyen et al, 2015a). MPAN is a product of the OH-initiated oxidation of MACR in an environment with a high NO 2 /NO ratio.…”

Section: Resultsmentioning

confidence: 99%

“…For isoprene, the low-NO oxidation pathway leads to low-volatility products, such as isoprene hydroperoxides (ISOPOOH), that can go on to form significant quantities of SOA via formation of isoprene epoxides (IEPOX) ( Fig. 1) (Paulot et al, 2009;Surratt et al, 2010;Lin et al, 2012). The high-NO pathway can also form SOA via the formation of methacrolein (MACR), which can react further to form SOA constituents such as 2-methylglyceric acid (2-MGA) and corresponding oligomers (Kroll et al, 2006;Surratt et al, 2006Surratt et al, , 2010Nguyen et al, 2015a) (Fig.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Low-NO atmospheric oxidation pathways in a polluted megacity

et al. 2021

View full text Add to dashboard Cite

Abstract. The impact of emissions of volatile organic compounds (VOCs) to the atmosphere on the production of secondary pollutants, such as ozone and secondary organic aerosol (SOA), is mediated by the concentration of nitric oxide (NO). Polluted urban atmospheres are typically considered to be “high-NO” environments, while remote regions such as rainforests, with minimal anthropogenic influences, are considered to be “low NO”. However, our observations from central Beijing show that this simplistic separation of regimes is flawed. Despite being in one of the largest megacities in the world, we observe formation of gas- and aerosol-phase oxidation products usually associated with low-NO “rainforest-like” atmospheric oxidation pathways during the afternoon, caused by extreme suppression of NO concentrations at this time. Box model calculations suggest that during the morning high-NO chemistry predominates (95 %) but in the afternoon low-NO chemistry plays a greater role (30 %). Current emissions inventories are applied in the GEOS-Chem model which shows that such models, when run at the regional scale, fail to accurately predict such an extreme diurnal cycle in the NO concentration. With increasing global emphasis on reducing air pollution, it is crucial for the modelling tools used to develop urban air quality policy to be able to accurately represent such extreme diurnal variations in NO to accurately predict the formation of pollutants such as SOA and ozone.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Low-NO atmospheric oxidation pathways in a polluted megacity

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Volatile organic compounds (VOCs) play an essential role in the formation of ground-level ozone (O 3 ) and secondary organic aerosols (SOA) (Zhang et al, 2014). Researches had found that under suitable meteorological conditions such as high temperature, intense light, low humidity, low wind speed, etc., VOCs emitted from various sources can react with NO x and OH radicals to generate ozone and SOA (Hui et al, 2019;Li et al, 2020). By analyzing the VOCs pollution characteristics of a liquefied petroleum gas (LPG) during 1 day, Chen et al (2001) found the alkanes with short carbon chain contributed 10% of ozone production in Santiago.…”

Section: Introductionmentioning

confidence: 99%

Pollution Characteristics and Key Reactive Species of Volatile Organic Compounds in Beijing-Tianjin-Hebei Area, China

Guan

Zhang

et al. 2020

Aerosol Air Qual. Res.

View full text Add to dashboard Cite

Volatile organic compounds (VOCs) are important precursors in the formation of ground-level ozone. In this study, the hourly mixing ratios of 61 ambient VOC species were monitored from 2018 till 2019 in 10 cities in the Beijing-Tianjin-Hebei (BTH) area of China, and the VOC distributions, speciation and photochemistry were also examined. The highest mixing ratios were found in the south, viz., Langfang (LF), Baoding (BD), Handan (HD) and Shijiazhuang (SJZ), and the lowest ones, in the north, viz., Chengde (CD) and Zhangjiakou (ZJK). In all of the cities, alkanes were the most abundant VOC component (50%), whereas ethane and propane were the most concentrated species. The mixing ratios of the VOCs exhibited a daily double peak as a result of the varying intensity of the photochemical reactions and the formation of the inversion layer. Additionally, the chemical reactivity of the VOCs was evaluated by calculating the loss rate of OH (L OH) for each species. Our results indicated that the alkenes and aromatics possessed higher L OH values as well as higher ozone formation potential (OFP) and secondary organic aerosol formation potential (SOAp) values than the alkanes. Based on the diagnostic ratios of propane/n-butane, propane/i-butane, cis-2-butane/trans-2-butane, toluene/benzene and xylene/ethylbenzene, motor vehicle emissions contributed significantly to the ambient VOCs in the area.

show abstract

“…6,10,11 Beijing is a megacity which continues to suffer from severe air pollution events despite recent reductions in primary emission of PM [12][13][14] and nitrogen oxides (NO x ). 15 These have been associated with high emissions of VOC from diverse sources 16,17 which lead to enhanced ozone production 18,19 and SOA formation 20 alongside regional transport which is an important source of semi-volatile organic compounds (SVOC), intermediate-volatility organic compounds (IVOC), POA and SOA in Beijing during the summertime. 21,22 Historically, source apportionment of OA has been limited to low timeresolution high molecular precision offline measurements of molecular tracers, focusing on the behaviour of specic VOC systems including isoprene, [23][24][25][26] apinene 27 and toluene.…”

Section: Introductionmentioning

confidence: 99%