Volatile organic compounds (VOCs) during non-haze and haze days in Shanghai: characterization and secondary organic aerosol (SOA) formation

Han, Deming; Wang, Zhen; Cheng, Jin; Wang, Qian; Chen, Xiao‐Jia; Wang, Heling

doi:10.1007/s11356-017-9433-3

Cited by 85 publications

(24 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Benzene is an important component of NMHCs, and the ratio of toluene‐to‐benzene (T/B) is often used to identify sources of pollution. When the T/B ratio is approximately 2, this means that the main source of NMHCs is a traffic emission source (Barletta et al, ; D. Han et al, ). When the ratio of T/B is greater than 2, this indicates that volatile organic solvents, such as paint, are also an important source of NMHCs emissions (Xu et al, ), in addition to the traffic source.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Source Apportionment and Secondary Transformation of Atmospheric Nonmethane Hydrocarbons in Chengdu, Southwest China

et al. 2018

View full text Add to dashboard Cite

Nonmethane hydrocarbons (NMHCs) have an important influence on the formation of photochemical smog and secondary organic aerosols in the atmosphere. We investigated 55 NMHCs in Chengdu from 27 October 2016 to 30 September 2017 to identify their sources, pollution levels, and secondary transformation potential. The average concentration of NMHCs in Chengdu was 41.8 ± 20.8 ppbv. Meteorological conditions play a vital role in the formation and dispersion of NMHCs, PM2.5, and O3. The photochemical conversion of NMHCs was inhibited by lower solar radiation, leading to low O3 concentrations and high NMHC concentrations. Aromatics and alkenes played a leading role in the secondary transformation, accounting for 60 ± 16% and 29 ± 11% of the total secondary formation potential, respectively. The southwest air mass trajectory was the most significant transportation path affecting the NMHC concentration in Chengdu. The results of the positive matrix factorization model indicated that there were seasonal differences in the sources of NMHCs in Chengdu. Four major emission sources were identified, namely, vehicle exhaust, industrial, paint solvents, and biogenic sources. Vehicle exhaust emissions were the greatest contributor to NMHCs in Chengdu, accounting for approximately 45% of the NMHCs. Overall, toluene, m/p‐xylene and ethylbenzene constitute a large fraction of the calculated ozone and secondary aerosol formation potential. Future studies should consider targeting these compounds when evaluating ozone and aerosol reduction strategies. However, in terms of total control of NMHC pollution, Chengdu should focus on effective control measures for traffic emissions.

show abstract

Section: Resultsmentioning

confidence: 99%

“…Benzene is an important component of NMHCs, and the ratio of toluene-to-benzene (T/B) is often used to identify sources of pollution. When the T/B ratio is approximately 2, this means that the main source of NMHCs is a traffic emission source (Barletta et al, 2008;D. Han et al, 2017).…”

Section: Specific Ratios Of Nmhcsmentioning

confidence: 99%

Source Apportionment and Secondary Transformation of Atmospheric Nonmethane Hydrocarbons in Chengdu, Southwest China

et al. 2018

View full text Add to dashboard Cite

show abstract

“…In addition, the ratio of xylene/ethylbenzene (X/E) is generally used to illustrate the aging of air masses (Han et al, 2017). The reaction rate of m/p-xylene with OH radicals is faster than ethylbenzene.…”

Section: Diagnostic Ratios Of Vocsmentioning

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

“…Non-methane VOCs (NMVOCs) emitted by biological and anthropogenic sources are important precursors of atmospheric ozone because VOC oxidation in the presence of high NO x concentrations and sunlight leads to the formation of tropospheric ozone [1][2][3]. On the other hand, certain VOC species, i.e., isoprene, benzene and toluene, can transfer to secondary organic aerosols (SOA) and directly contribute to the organic matter in PM 2.5 [4,5]. Therefore, although the VOC content in the atmosphere is small, VOCs do have an important impact on air quality.…”

Section: Introductionmentioning

confidence: 99%

A Retrieval of Glyoxal from OMI over China: Investigation of the Effects of Tropospheric NO2

et al. 2019

View full text Add to dashboard Cite

East China is the 'hotspot' of glyoxal (CHOCHO), especially over the Pearl River Delta (PRD) region, where glyoxal is yielded from the oxidation of aromatics. To better understand the glyoxal spatial-temporal characteristics over China and evaluate the effectiveness of atmospheric prevention efforts on the reduction of volatile organic compound (VOC) emissions, we present an algorithm for glyoxal retrieval using the Ozone Monitoring instrument (OMI) over China. The algorithm is based on the differential optical absorption spectroscopy (DOAS) and accounts for the interference of the tropospheric nitrogen dioxide (NO 2 ) spatial-temporal distribution on glyoxal retrieval. We conduct a sensitively test based on a synthetic spectrum to optimize the fitting parameters set. It shows that the fitting interval of 430-458 nm and a 4th order polynomial are optimal for glyoxal retrieval when using the daily mean value of the earthshine spectrum in the Pacific region as a reference. In addition, tropospheric NO 2 pre-fitted during glyoxal retrieval is first proposed and tested, which shows a ±10% variation compared with the reference scene. The interference of NO 2 on glyoxal was further investigated based on the OMI observations, and the spatial distribution showed that changes in the NO 2 concentration can affect the glyoxal result depending on the NO 2 spatial distribution. A method to prefix NO 2 during glyoxal retrieval is proposed in this study and is referred to as OMI-CAS. We perform an intercomparison of the glyoxal from the OMI-CAS with the seasonal datasets provided by different institutions for North China (NC), South China (SC), the Yangtze River Delta (YRD) and the ChuanYu (CY) region in southwestern China in the year 2005. The results show that our algorithm can obtain the glyoxal spatial and temporal variations in different regions over China. OMI-CAS has the best correlations with other datasets in summer, with the correlations between OMI-CAS and OMI-Harvard, OMI-CAS and OMI-IUP, and OMI-CAS and Sciamachy-IUP being 0.63, 0.67 and 0.67, respectively. Autumn results followed, with the correlations of 0.58, 0.36 and 0.48, respectively, over China. However, the correlations are less or even negative for spring and winter. From the regional perspective, SC has the best correlation compared with other regions, with R reaching 0.80 for OMI-CAS and OMI-IUP in summer. The discrepancies between different glyoxal datasets can be attributed to the fitting parameters and larger glyoxal retrieval uncertainties. Finally, useful recommendations are given based on the results comparison according to region and season.

show abstract

Volatile organic compounds (VOCs) during non-haze and haze days in Shanghai: characterization and secondary organic aerosol (SOA) formation

Cited by 85 publications

References 52 publications

Source Apportionment and Secondary Transformation of Atmospheric Nonmethane Hydrocarbons in Chengdu, Southwest China

Source Apportionment and Secondary Transformation of Atmospheric Nonmethane Hydrocarbons in Chengdu, Southwest China

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

A Retrieval of Glyoxal from OMI over China: Investigation of the Effects of Tropospheric NO2

Contact Info

Product

Resources

About