Pollution characteristics and sources of carbonyl compounds in a typical city of Fenwei Plain, Linfen, in summer

Jieya Sun; Youjiang He; Yi Ning; Zhigang Xue; Hengyuan Wang; Yujie Zhang; Jinghua Ma; Xuan Chen; Fahe Chai

doi:10.1016/j.envpol.2022.120913

Pollution characteristics and sources of carbonyl compounds in a typical city of Fenwei Plain, Linfen, in summer

Environ Pollut. 2023 Mar 1:320:120913. doi: 10.1016/j.envpol.2022.120913. Epub 2022 Dec 20.

Authors

Jieya Sun¹, Youjiang He², Yi Ning¹, Zhigang Xue², Hengyuan Wang³, Yujie Zhang², Jinghua Ma², Xuan Chen⁴, Fahe Chai²

Affiliations

¹ State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China; Zhth Research Institute for Environmental Science, Beijing, 100085, China.
² State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
³ Beijing Pengyu Changya Environmental Technology CO., Ltd., Beijing, 102200, China.
⁴ State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China. Electronic address: chenxuan@craes.org.cn.

PMID: 36563991
DOI: 10.1016/j.envpol.2022.120913

Abstract

Field measurements of atmospheric carbonyl compounds (carbonyls) and essential precursors of O₃ were carried out in the urban area of Linfen City (Linfen) where serious O₃ pollution has occurred in recent years due to its unique terrain. Carbonyls were sampled using an automatic carbonyl sampler in August 2019 to determine their pollution characteristics and sources. An average concentration of ten carbonyls was 27 ± 5.7 μg m^-3 detected using an HPLC-UV system. The concentrations of most detected carbonyls in August were significantly higher than those in the winter months in China. Acetone, formaldehyde and acetaldehyde were the most abundant species, accounting for 73% of all detected carbonyls. Formaldehyde, acetaldehyde, and methacrolein (MACR) were the most significant contributors to OH• reactivity and ozone generation, indicating that these three carbonyls were the key species influencing the production of O₃. The concentrations of formaldehyde, acetaldehyde, and MACR showed similar diurnal variations on most days, with high values during the daytime reaching a peak at 10:00. However, the concentrations of the latter two species varied less than that of formaldehyde during the day. The acetone concentration generally increased continuously from morning to night, with the maximum value around 22:00. The C1/C2 ratio in summer was higher than that in winter. These results indicated that the carbonyls in Linfen were not only affected by anthropogenic sources such as vehicle exhaust but also by secondary photochemical production. The results of formaldehyde source apportionment showed that the contributions of background, primary, and secondary sources to the observed formaldehyde concentration were 27.6%, 36.6%, and 35.8%, respectively. Additionally, this study revealed for the first time that the vertical transport of air masses containing high concentrations of O₃ and NO₃ radicals above the boundary layer could increase the secondary generation of formaldehyde at night in summer.

Keywords: Anthropogenic emissions; Backward trajectory; Carbonyl compounds; Diurnal variation; Photochemical production; Source identification.

MeSH terms

Acetaldehyde / analysis
Acetone / analysis
Air Pollutants* / analysis
China
Environmental Monitoring / methods
Formaldehyde / analysis
Volatile Organic Compounds* / analysis

Substances

Air Pollutants
Acetone
Formaldehyde
Acetaldehyde
methacrylaldehyde
Volatile Organic Compounds