| Title: | [Ozone Formation and Key VOCs of a Continuous Summertime O(3) Pollution Event in Ji'nan] |
| Author(s): | Sun XY; Zhao M; Shen HQ; Liu Y; Du MY; Zhang WJ; Xu HY; Fan GL; Gong HL; Li QS; Li DQ; Gao XM; Zhang LN; |
| Address: | "Ji'nan Ecological and Environmental Monitoring Center, Shandong Province, Ji'nan 250101, China. Environment Research Institute, Shandong University, Qingdao 266237, China. School of Water Conservancy and Environment, University of Ji'nan, Ji'nan 250024, China. Laoling Branch of Dezhou Ecological Environment Bureau, Laoling 253600, China" |
| DOI: | 10.13227/j.hjkx.202106068 |
| ISSN/ISBN: | 0250-3301 (Print) 0250-3301 (Linking) |
| Abstract: | "In the summer of 2019, field measurements of ozone (O(3)) and its precursors[volatile organic compounds (VOCs) and nitrogen oxides (NO(x))] were carried out at an urban site in Ji'nan. We found that the daily maximum 8-hour averages phi(O(3)) were (103.0+/-14.5)x10(-9). The average phi(NO(x)) and phi(VOCs), which are ozone precursors, were (16.7+/-11.3)x10(-9)and (22.4+/-9.4)x10(-9), respectively. The .OH reactivity of VOCs was determined (9.6+/-3.8) s(-1). Ji'nan suffered from serious O(3) pollution. An observation-constrained chemical box model was deployed to evaluate in situ photochemical O(3) production, which indicated that chemical reactions made positive contributions to O(3) production rates between 07:00 and 19:00 LT, with the average hourly O(3) production rate of 35.6x10(-9) h(-1). To evaluate the effectiveness of various ozone precursor control strategies in reducing ozone pollution, we combined the observation-based model (OBM) with the relative incremental reactivity (RIR) method. The key indicators that affect the local ozone production rate were identified. Ji'nan was under VOC-limited conditions and the key VOC precursors were alkenes. The O(3) formation mechanism changed from the VOC-limited regime in the morning to the transitional regime in the afternoon. Correspondingly, the simulated local O(3) production rate was increased from 18.3x10(-9) h(-1) to 29.6x10(-9) h(-1). To further explore the role of anthropogenic emissions in ozone pollution, we used the positive matrix factorization (PMF) model to identify the major sources contributing to VOCs. The major sources in Ji'nan were vehicular exhaust and gasoline evaporation, accounting for more than 50% of the observed VOCs. Therefore, constraints on vehicular emissions is the most effective strategy to control O(3) pollution in Ji'nan" |
| Keywords: | *Air Pollutants/analysis China Environmental Monitoring *Ozone/analysis Vehicle Emissions/analysis *Volatile Organic Compounds/analysis Ji'nan VOCs source apportionment ozone(O3) relative incremental reactivity(RIR) sensitivity analysis; |
| Notes: | "MedlineSun, Xiao-Yan Zhao, Min Shen, Heng-Qing Liu, Yang Du, Ming-Yue Zhang, Wen-Juan Xu, Hong-Yu Fan, Guo-Lan Gong, Hua-Lin Li, Qing-Song Li, Da-Qiu Gao, Xiao-Mei Zhang, Li-Na chi China 2022/01/26 Huan Jing Ke Xue. 2022 Feb 8; 43(2):686-695. doi: 10.13227/j.hjkx.202106068" |
