Abstract:
To study the characteristics of volatile organic compounds (VOCs) and their contribution to atmospheric fine particulate matter (PM
2.5) and ozone (O
3), the measurements of VOCs in the atmosphere were conducted by a gas chromatography coupled with a mass spectrometry in a large coal chemical industrial park during the summer of 2021. The levels, composition characteristics, diurnal variation, potential sources of VOCs, and their contributions to the formation of O
3 and secondary organic aerosols (SOA) were analyzed. The results were shown as followed: ①The total mixing ratio of VOCs was (89.21±50.57) ×10
-9 in the coal chemical industrial park during the observed period, which was significantly higher than that detected at the urban site in the city where the coal chemical industrial park was located. ②Oxygenated VOCs (OVOCs) were the most abundant VOCs, accounting for 32.6% of the total VOCs. Ethanol, propionaldehyde and formaldehyde were the top three OVOCs species. ③The total ozone formation potential (OFP) of VOCs was 595.64 μg/m
3. The contributions of VOCs to OFP were OVOCs > alkenes > aromatics > alkanes > halogenated hydrocarbons > sulphur-containing VOC > alkyne. The top ten VOCs species contributing to OFP were OVOCs, alkenes and aromatics, of which propionaldehyde contributed the most (22.2%). ④The top VOCs contributing to SOA formation potential (SOAFP) were 1,2,3-trimethylbenzene, m/p-xylene, o-xylene and ethylbenzene , of which 1,2,3-trimethylbenzene contributed the most (55.7%). Overall, OVOCs and aromatic hydrocarbons (propionaldehyde, formaldehyde, 1,2,3-trimethyl benzene and m/p-xylene) in coal chemical industrial park contribute significantly to the complex air pollution, and should be the key species to carry out the joint control of PM
2.5 and O
3.