| Title: | Characterizing sources and ozone formations of summertime volatile organic compounds observed in a medium-sized city in Yangtze River Delta region |
| Author(s): | Wang W; Fang H; Zhang Y; Ding Y; Hua F; Wu T; Yan Y; |
| Address: | "School of Ecology and Environment, Anhui Normal University, Wuhu, 241000, China. School of Ecology and Environment, Anhui Normal University, Wuhu, 241000, China; Center of Cooperative Innovation for Recovery and Reconstruction of Degraded Ecosystem in Wanjiang City Belt, Wuhu, 241000, China. Electronic address: hfang@ahnu.edu.cn. Wuhu Ecological and Environmental Monitoring Center of Anhui Province, Wuhu, 241005, China. Wuhu Institute of Technology, Wuhu, 241006, China. School of Ecology and Environment, Anhui Normal University, Wuhu, 241000, China; Center of Cooperative Innovation for Recovery and Reconstruction of Degraded Ecosystem in Wanjiang City Belt, Wuhu, 241000, China. Electronic address: wuting19@mail.ahnu.edu.cn. School of Ecology and Environment, Anhui Normal University, Wuhu, 241000, China; Center of Cooperative Innovation for Recovery and Reconstruction of Degraded Ecosystem in Wanjiang City Belt, Wuhu, 241000, China. Electronic address: yanyunzhi@ahnu.edu.cn" |
| DOI: | 10.1016/j.chemosphere.2023.138609 |
| ISSN/ISBN: | 1879-1298 (Electronic) 0045-6535 (Linking) |
| Abstract: | "Volatile organic compounds (VOCs) emitted from various sources into atmosphere could cause serious O(3) pollution in urban areas. Although characterizations of ambient VOCs have been extensively studied in megacities, they are scarcely investigated in medium/small-sized cities, which could present different pollution characterizations due to the factors like emission sources and populations. Herein, field campaigns were conducted concurrently at six sites in a medium-sized city of Yangtze River Delta region to determine ambient levels, O(3) formations and source contributions of summertime VOCs. During the observation period, the total VOC (TVOCs) mixing ratios ranged from 27.10 +/- 3.35 to 39.09 +/- 10.84 ppb at six sites. The ozone formation potential (OFP) results showed that alkenes, aromatics and oxygenated VOCs (OVOCs) were dominant contributors, together sharing 81.4% of total calculated OFPs. Ethene ranked the largest OFP contributor at all six sites. A high VOC site, KC, was selected as a case to detailed analyze diurnal variations of VOCs and its relationship with O(3). Consequently, diurnal patterns varied with VOC groups, and TVOC concentrations were lowest during strong photochemical period (15:00-18:00 p.m.), opposite to the O(3) peak. VOCs/NOx ratios and observation-based model (OBM) analysis revealed that O(3) formation sensitivity was primarily in transition regime in summertime and that the reduction of VOCs rather than NO(X) would be more efficient to suppress O(3) peak at KC during pollution episode. Additionally, source apportionment conducted with positive matrix factorization (PMF) indicated that industrial emission (29.2%-51.7%) and gasoline exhaust (22.4%-41.1%) were major sources for VOCs at all six sites, and that VOCs from industrial emissions and gasoline exhaust were the key precursors for ozone formation. Our results shed light on the importance of alkenes, aromatics and OVOCs in forming O(3) and propose that preferentially reducing VOCs especially those from industrial emission and gasoline exhaust would benefit alleviating O(3) pollution" |
| Keywords: | *Ozone/chemistry Cities *Air Pollutants/analysis *Volatile Organic Compounds/analysis Gasoline/analysis Alkenes China Environmental Monitoring/methods Vehicle Emissions/analysis Medium-sized city Ozone formation Pollution characteristics Source apportionm; |
| Notes: | "MedlineWang, Wenjing Fang, Hua Zhang, Ying Ding, Yueyue Hua, Fei Wu, Ting Yan, Yunzhi eng England 2023/04/07 Chemosphere. 2023 Jul; 328:138609. doi: 10.1016/j.chemosphere.2023.138609. Epub 2023 Apr 4" |
