| Title: | "Assessment of summertime O(3) formation and the O(3)-NO(X)-VOC sensitivity in Zhengzhou, China using an observation-based model" |
| Author(s): | Wang X; Yin S; Zhang R; Yuan M; Ying Q; |
| Address: | "Research Institute of Environmental Science, College of Chemistry, Zhengzhou University, Zhengzhou 450001, China. Research Institute of Environmental Science, School of Ecology and Environment, Zhengzhou University, Zhengzhou 450001, China. Electronic address: shashayin@zzu.edu.cn. Research Institute of Environmental Science, School of Ecology and Environment, Zhengzhou University, Zhengzhou 450001, China. Environmental Protection Monitoring Center Station of Zhengzhou, Zhengzhou 450007, China. Department of Civil and Environmental Engineering, Texas A&M University, College Station, TX 77843-3136, USA. Electronic address: qying@civil.tamu.edu" |
| DOI: | 10.1016/j.scitotenv.2021.152449 |
| ISSN/ISBN: | 1879-1026 (Electronic) 0048-9697 (Linking) |
| Abstract: | "Zhengzhou, the provincial capital of Henan province in Central China and a major hub of the country's transportation network, has been suffering from severe summertime ozone (O(3)) pollution. Simultaneous field measurements of O(3) and its precursors, including NO(x), CO, HONO, and 106 volatile organic compounds (VOCs), were conducted at an urban site (the municipal environmental monitoring station, MEM) in Zhengzhou in July 2019. The Community Multiscale Air Quality (CMAQ) model, which incorporates the Master Chemical Mechanism (MCMv3.3.1), was modified to work as a 0-D observation-based photochemical box model to assess the sources and sinks of HO(x) radicals and O(3), and the OH reactivity (K(OH)) and ozone formation potential (OFP) of major VOC groups. In addition, the O(3)-NO(x)-VOC sensitivity was evaluated using the relative incremental reactivity (RIR) and O(3) formation isopleth techniques. The OH radicals were mainly generated from the propagation reaction of HO(2) + NO (91-95%). The daily average mixing ratios of OH and HO(2) radicals were significantly higher during high O(3) days, reaching as high as 4.8 x 10(6) and 7.7 x 10(8) molecules cm(-3), respectively. Photochemical O(3) formation was mostly due to the conversion of NO to NO(2) by HO(2) radicals (52-54%), while the NO(2) + OH reaction was the main contributor to O(3) destruction (70- 76%). Alkenes and aromatics were the main anthropogenic VOC contributors to K(OH) and OFP. Contributions of biogenic VOCs became much more important on high O(3) days, correlating with the increase in temperature and solar radiation. RIR analysis showed that the O(3) formation was under the VOC-limited on low O(3) days but was in the transition regime during the O(3) pollution buildup and persisting days. These results are generally consistent with those based on the O(3) formation isopleth. This paper provides important corroborative scientific evidence urgently needed by local governments to formulate O(3) pollution control strategies" |
| Keywords: | *Air Pollutants/analysis *Air Pollution China Environmental Monitoring *Ozone/analysis *Volatile Organic Compounds/analysis Central China Master chemical mechanism O(3)-NO(x)-VOC sensitivity Ozone Volatile organic compounds; |
| Notes: | "MedlineWang, Xudong Yin, Shasha Zhang, Ruiqin Yuan, Minghao Ying, Qi eng Netherlands 2021/12/24 Sci Total Environ. 2022 Mar 20; 813:152449. doi: 10.1016/j.scitotenv.2021.152449. Epub 2021 Dec 20" |
