| Title: | Observation and modeling of organic nitrates on a suburban site in southwest China |
| Author(s): | Li C; Wang H; Chen X; Zhai T; Ma X; Yang X; Chen S; Li X; Zeng L; Lu K; |
| Address: | "State Key Joint Laboratory of Environmental Simulation and Pollution Control, The State Environmental Protection Key Laboratory of Atmospheric Ozone Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China. School of Atmospheric Sciences, Sun Yat-sen University, Zhuhai 519082, China; Guangdong Provincial Observation and Research Station for Climate Environment and Air Quality Change in the Pearl River Estuary, Key Laboratory of Tropical Atmosphere-Ocean System, Ministry of Education, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, China. Electronic address: wanghch27@mail.sysu.edu.cn. State Key Joint Laboratory of Environmental Simulation and Pollution Control, The State Environmental Protection Key Laboratory of Atmospheric Ozone Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China. Electronic address: k.lu@pku.edu.cn" |
| DOI: | 10.1016/j.scitotenv.2022.160287 |
| ISSN/ISBN: | 1879-1026 (Electronic) 0048-9697 (Linking) |
| Abstract: | "Here we report the measurements of two types of organic nitrates (ONs), peroxy nitrates (PNs) and alkyl nitrates (ANs), in Chengdu, China, during summer 2019. The average concentrations of PNs and ANs were 1.3 +/- 1.1 ppbv and 0.5 +/- 0.3 ppbv during the day, with peaks of 7.7 ppbv and 1.9 ppbv, respectively, which were in the middle and upper end of the reported levels in China. Much higher PNs and ANs concentrations were found during the photochemical pollution period than during the clean period. Box model simulation was capable of reproducing PNs during photochemical pollution episodes but showed overestimation in other periods, which was likely caused by the simplification of PNs sinks. The OH oxidation of aldehydes and ketones was the most important source of the PNs precursors, PAs (peroxyacyl radicals), except for the thermal decomposition of PNs, which was further confirmed by the relative incremental reactivity (RIR) analysis. The model basically reproduced the observed ANs by the refinement of related mechanisms, with isoprene contributing to its formation by 29.2 %. The observed PNs and total oxidants (O(x) = NO(2) + O(3)) showed a good positive correlation, with a ratio of PNs to O(x) of 0.079, indicating a strong suppression of PNs chemistry to ozone formation. The model quantified the suppression of PNs chemistry on the peak ozone production rate by 21.3 % on average and inhibited ozone formation up to 20 ppbv in total. The RIR analysis suggests that the production of both O(3) and ANs was in the VOC-limited regime and highlights the importance of VOC control (especially aromatics) to mitigate photochemical pollution in Chengdu. The study deepens the understanding of photochemical pollution in urban areas of western China and further emphasizes the impacts of ONs chemistry on ozone pollution" |
| Keywords: | *Air Pollutants/analysis *Volatile Organic Compounds/analysis Environmental Monitoring *Ozone/analysis Environmental Pollution/analysis China Nitrates/analysis Alkyl nitrates Budge Organic nitrates Ozone pollution Peroxy nitrates Photochemistry; |
| Notes: | "MedlineLi, Chunmeng Wang, Haichao Chen, Xiaorui Zhai, Tianyu Ma, Xuefei Yang, Xinping Chen, Shiyi Li, Xin Zeng, Limin Lu, Keding eng Netherlands 2022/11/22 Sci Total Environ. 2023 Feb 10; 859(Pt 2):160287. doi: 10.1016/j.scitotenv.2022.160287. Epub 2022 Nov 21" |
