Characterization of photochemical losses of volatile organic compounds and their implications for ozone formation potential and source apportionment during summer in suburban Jinan, China

Zhenguo Liu; Baolin Wang; Chen Wang; Yuchun Sun; Chuanyong Zhu; Lei Sun; Na Yang; Guolan Fan; Xiaoyan Sun; Zhiyong Xia; Guang Pan; Changtong Zhu; Yichao Gai; Xiaoyu Wang; Yang Xiao; Guihuan Yan; Chongqing Xu

doi:10.1016/j.envres.2023.117158

Characterization of photochemical losses of volatile organic compounds and their implications for ozone formation potential and source apportionment during summer in suburban Jinan, China

Environ Res. 2023 Dec 1;238(Pt 1):117158. doi: 10.1016/j.envres.2023.117158. Epub 2023 Sep 17.

Authors

Zhenguo Liu¹, Baolin Wang², Chen Wang³, Yuchun Sun¹, Chuanyong Zhu¹, Lei Sun¹, Na Yang¹, Guolan Fan⁴, Xiaoyan Sun⁴, Zhiyong Xia⁴, Guang Pan⁴, Changtong Zhu¹, Yichao Gai¹, Xiaoyu Wang¹, Yang Xiao⁵, Guihuan Yan⁶, Chongqing Xu⁷

Affiliations

¹ School of Environmental Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353, China.
² School of Environmental Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353, China. Electronic address: wangbaolin@qlu.edu.cn.
³ School of Environmental Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353, China. Electronic address: wangchen@qlu.edu.cn.
⁴ Jinan Eco-environmental Monitoring Center of Shandong Province, Jinan, 250101, China.
⁵ Zibo Eco-environmental Monitoring Center of Shandong Province, Zibo, 255000, China.
⁶ Ecology Institute of Shandong Academy of Sciences, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250103, China.
⁷ School of Environmental Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353, China; Ecology Institute of Shandong Academy of Sciences, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250103, China.

PMID: 37726031
DOI: 10.1016/j.envres.2023.117158

Abstract

Volatile organic compounds (VOCs) undergo substantial photochemical losses during their transport from emission sources to receptor sites, resulting in serious implications for their source apportionment and ozone (O₃) formation. Based on the continuous measurements of VOCs in suburban Jinan in August 2022, the effects of photochemical losses on VOC source contributions and O₃ formation were evaluated in this study. The observed and initial concentrations of total VOCs (TVOC) were 12.0 ± 5.1 and 16.0 ± 7.4 ppbv, respectively. Throughout the observation period, alkenes had the most prominent photochemical losses (58.2%), followed by aromatic hydrocarbons (23.1%), accounting for 80.6% and 6.9% of the total losses, respectively. During high O₃ episodes, the photochemical loss of VOCs was 6.9 times higher than that during the cleaning period. Alkene losses (exceeding 67.3%), specifically losses of isoprene, propylene, ethylene, and n-butene, dominated the total losses of VOCs during the O₃ increase period. Eight sources of VOCs were identified by positive matrix factorization (PMF) based on the observed and initial concentration data (OC-PMF and IC-PMF, respectively). Concentrations of all emission sources in the OC-PMF were underestimated by 2.4%-57.1%. Moreover, the contribution of each emission source was over- or underestimated compared with that in case of the IC-PMF. The contributions of biogenic and motor vehicle exhaust emissions were underestimated by 5.3 and 2.8 percentage points, respectively, which was associated with substantial oxidation of the emitted high-reactive species. The contributions of coal/biomass burning and natural gas were overestimated by 2.4 and 3.9 percentage points, respectively, which were related to the emission of low-reactive species (acetylene, ethane, and propane). Based on our results, the photochemical losses of VOCs grossly affect their source apportionment and O₃ formation. Thus, photochemical losses of VOCs must be thoroughly accounted to establish a precise scientific foundation for air-pollution control strategies.

Keywords: Ozone formation potential; Photochemical losses; Source apportionment; Volatile organic compounds.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Air Pollutants* / analysis
China
Environmental Monitoring
Ozone* / analysis
Vehicle Emissions / analysis
Volatile Organic Compounds* / analysis

Substances

Ozone
Air Pollutants
Volatile Organic Compounds
Vehicle Emissions