Next Article in Journal
Enhanced Mid-Latitude Meridional Heat Imbalance Induced by the Ocean
Previous Article in Journal
Seasonal Analysis of Cloud-To-Ground Lightning Flash Activity in the Western Antarctica
Open AccessArticle

The Characteristics of Ambient Non-Methane Hydrocarbons (NMHCs) in Lanzhou, China

by Yajun Wu 1, Jun Hu 1, Han Wang 1,2, Hui Li 1,2, Hefeng Zhang 1,2,3, Fahe Chai 1,2 and Shulan Wang 1,2,*
1
Atmospheric Environment Institute, Chinese Research Academy of Environmental Sciences, Ministry of Ecology and Environment (MEE), Beijing 100012, China
2
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
3
National Joint Research Center for Tackling Key Problems in Air Pollution Control, Ministry of Ecology and Environment (MEE), Beijing 100012, China
*
Author to whom correspondence should be addressed.
Atmosphere 2019, 10(12), 745; https://doi.org/10.3390/atmos10120745
Received: 1 October 2019 / Revised: 11 November 2019 / Accepted: 24 November 2019 / Published: 26 November 2019
(This article belongs to the Section Air Quality)
Non-methane hydrocarbons (NMHCs) from four sampling sites in Lanzhou, a petrochemical industrialized city in northwest China, was sampled by stainless steel canisters and measured by gas chromatography–mass selective detection/flame ionization detection (GC–MSD/FID) in May and June of 2017. Based on these results, the contributions of NMHCs to the ozone (O3) and secondary organic aerosols (SOA), differences in tracer ratios, and source apportionment by principal component analysis (PCA) were analyzed. The results showed that the total NMHCs concentration in Lanzhou was 48.4 ± 48.3 ppbv (parts per billion by volume) during the observation and it was higher in May (78.6 ppbv) than in June (37.8 ppbv); the highest NMHCs concentration was observed in industrial areas. Alkanes were the dominant group at all sites in Lanzhou and account for more than 60% of the NMHCs, while isopentane, n-butane n-pentane, propane and ethane were the major compounds. Additionally, the NMHCs in Lanzhou have made great contributions to O3 and SOA generation and the S1 site of the industrial area contributed the most to both of them. Propene, toluene, ethylbenzene and n-pentane were found to be more reactive with relatively high contributions to ozone formation. Aromatics and high carbon alkanes were major contributors to SOA formation potential (SOAp) (i.e., toluene, m,p-xylene, dodecane, undecane, n-tanane, benzene and ethylbenzene) in Lanzhou. Based on the specific volatile organic compounds (VOCs) ratio method and the PCA mode,the observation sites in Lanzhou were greatly affected by the surrounding industrial areas. The sources consisted of petrochemical industry, vehicle emissions, solvent usage and combustion sources, which contributed to 33.9%, 31.6%, 19.2% and 7.9% of the total monitored NMHCs, respectively. From different sites, though the influence of regional transport was not very significant on the whole, it also affected the NMHCs of nonindustrial areas based on the ratio of xylene to ethyl-benzene (X/E), especially the S4 site; vehicle emission was less important compared to sources from petrochemical industries in S1, as characterized by relatively higher toluene to benzene (T/B) ratios. However, vehicle emission has significant influence on NMHCs in S4. Overall, local emissions are the main source of NMHCs in Lanzhou and the petrochemical industry has a great influence on the distribution of NMHCs in the whole region.
Keywords: non-methane hydrocarbons (NMHCs); O3 and SOA formation potential; source apportionment non-methane hydrocarbons (NMHCs); O3 and SOA formation potential; source apportionment
MDPI and ACS Style

Wu, Y.; Hu, J.; Wang, H.; Li, H.; Zhang, H.; Chai, F.; Wang, S. The Characteristics of Ambient Non-Methane Hydrocarbons (NMHCs) in Lanzhou, China. Atmosphere 2019, 10, 745.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop