为探究粤港澳大湾区秋季高浓度臭氧(O3)事件的污染特征及形成机制,本研究综合观测数据,利用基于观测的模型(OBM)和经验动力学方法(EKMA),以香港为例,分析该地区3次高浓度O3污染事件中O3浓度及前体物挥发性有机物(VOCs)的排放特征,评估VOCs对O3生成敏感性机制的影响和对O3生成的贡献.结果表明:在3次事件中,O3峰值分别为382.65、302.67和301.76μg/m3,对应的VOCs浓度均值分别为23.6×10-9、25.4×10-9和32.1×10-9.含氧挥发性有机物(OVOCs)在观测物种中占据主导地位,其中甲醇、甲醛和丙酮是体积分数前三的VOCs.EKMA曲线证实O3-氮氧化物(NOx)-VOCs之间的非线性关系取决于NOx与VOCs的即时浓度,观测期间上午时段为VOCs控制区,下午时段为NOx-VOCs协同控制区.光化学初始浓度(PIC)较实测值高8.2×10-9,表明忽视实际消耗的VOCs会低估本地VOCs光化学反应对O3生成的贡献.此外,由于O3前体物和自由基的种类及浓度的差异,导致了O3生成和损耗速率的不同,证实VOCs作为前体物对O3净生成过程的促进效应.通过对臭氧生成潜势(OFP)与羟基消耗速率(LOH)的计算可知,对OFP贡献率最高的VOCs组分依次为OVOCs(68.9%),烯烃(17.5%)和芳香烃(13.6%).甲醛和异戊二烯分别是香港秋季驱动O3生成以及羟基(OH)消耗的优势物种,其中甲醛的OFP为42.1~73.1μg/m3,异戊二烯的LOH为1.35~2.12s-1.基于后向轨迹聚类分析,香港背景点主要受东北风驱动的三类气团影响:长距离输送(52%)、短距离输送(28%)和本地源(20%).研究结果揭示本地VOCs光化学反应、不同VOCs对O3生成敏感性的响应特征以及区域传输与本地排放的协同作用对香港秋季O3污染具有重要影响.
Abstract
To investigate the pollution characteristics and formation mechanisms of ozone episodes in the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) during autumn, ozone (O3) concentrations and emission characteristics of volatile organic compounds (VOCs) were analyzed during three ozone episodesin Hong Kong.Observational data combined withobservation-based model(OBM) and the empirical kinetics modeling approach (EKMA) wasemployed to assess the impact of VOCs on O3 formation sensitivity mechanisms and contribution to O3 formation. The peak O3 values recorded during the three episodes were 382.65, 302.67, and 301.76μg/m3, with corresponding concentrations of VOCs measuring 23.6×10-9, 25.4×10-9, and 32.1×10-9, respectively. Oxygenated volatile organic compounds (OVOCs)were the most dominant of the observed species, with methanol, formaldehyde, and acetone being the three most prevalent by volume fraction. EKMA curves confirmedthat the nonlinear relationship among O3-nitrogen oxides (NOx)-VOCs depends ontheir instantaneous concentrations. The morning hours were characterized as VOC-limited regimes, while the afternoon hourswerethe transitional regime. The photochemical initial concentration (PIC) was 8.2×10-9 higher than measured concentration, indicating that neglecting photochemically VOCs consumption may lead to an underestimation of the contribution of local VOCs photochemical reactions to O3 formation. Furthermore, differences in the types and concentrations of O3 precursors and radicals resulted in varying O3 formation and loss rates, confirming the promoting effect of VOCs as precursors on net O3 formation. Based on O3 formation potential (OFP) and OH loss rate (LOH) calculations, the VOCs with the highest contribution to the OFP were OVOCs (68.9%), alkenes (17.5%), and aromatics (13.6%). Formaldehyde and isoprene were the dominant species driving O3 formation and hydroxyl radical (OH) consumption in the autumn in Hong Kong, respectively. The OFP of formaldehyde ranged from 42.1 to 73.1μg/m3, and the LOH of isoprene varied from 1.35 to 2.12s-1. Backward trajectory cluster analysis revealed that Hong Kong’s background site was primarily influenced by three air mass types driven by northeasterly winds: long-range transport (52%), short-range transport (28%), and local sources (20%). Results reveal that the photochemical reactions of VOCs, the response characteristics of different VOCs to the sensitivity of O3 formation, and the synergistic effect of regional transport and local emissions have a significant impact on the O3 pollution in Hong Kong during autumn.
关键词
臭氧 /
VOCs /
污染特征 /
香港 /
基于观测的模型(OBM)
Key words
ozone /
VOCs /
pollution characteristics /
Hong Kong /
observation-based model (OBM)
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] 钟博闻,周 俊,王 燕,等.我国臭氧生成敏感性研究进展 [J]. 中国环境科学, 2024,44(12):6522-6537. Zhong B W, Zhou J, Wang Y, et al. Review of ozone formation sensitivity in China [J]. China Environmental Science, 2024,44(12): 6522-6537.
[2] Wang T, Xue L K, Brimblecombe P, et al. Ozone pollution in China: A review of concentrations, meteorological influences, chemical precursors, and effects [J]. Science of the Total Environment, 2017, 575:1582-1596.
[3] Liu H, Liu S, Xue B, et al. Ground-level ozone pollution and its health impacts in China [J]. Atmospheric environment, 2018,173:223-230.
[4] Guo C, Wang X N, Wang Q, et al. Plant defense mechanisms against ozone stress: Insights from secondary metabolism [J]. Environmental and Experimental Botany, 2024,217:105553.
[5] Wang Y, Wang H, Guo H, et al. Long-term O3–precursor relationships in Hong Kong: field observation and model simulation [J]. Atmospheric Chemistry and Physics, 2017,17(18):10919-10935.
[6] HKSAR (the Hong Kong Special Administrative Region). Air quality in Hong Kong 2018 [R]. Hong Kong, China: The Government of the Hong Kong Special Administrative Region, 2018.
[7] 杨丽蓉,许 萌,徐学哲,等.银川市大气臭氧生成敏感性与VOCs来源解析 [J]. 环境科学, 2024,45(8):4419-4431. Yang L R, Xu M, Xu X Z,et al. Sensitivity analysis of atmospheric ozone and source apportionment of volatile organic compounds in Yinchuan city [J]. Environmental Science, 2024,45(8):4419-4431.
[8] 尉晴晴,杨威强,裴成磊,等.珠三角夏秋转换季臭氧污染成因及前体物减排策略分析 [J]. 环境科学, 2024,45(10):5695-5705. Yu Q Q, Yang W Q, Pei C L, et al. Analysis of ozone pollution and precursor control strategies in the Pearl River Delta during summer and autumn transition season [J]. Environmental Science, 2024,45(10): 5695-5705.
[9] 周婕萍,袁 斌,彭钰雯,等.珠三角冬季臭氧污染成因分析—以2020年1月一次污染过程为例 [J]. 中国环境科学, 2023,43(5):2198- 2209. Zhou J P, Yuan B, Peng Y W, et al. Causes of ozone pollution in the Pearl River Delta in Winter - A case study of pollution process in January 2020 [J]. China Environmental Science, 2023,43(5):2198- 2209.
[10] Feng X, Guo J, Wang Z, et al. Investigation of the multi-year trend of surface ozone and ozone-precursor relationship in Hong Kong [J]. Atmospheric Environment, 2023,315:120139.
[11] Wang F, Ho S S H, Man C L, et al. Characteristics and sources of oxygenated VOCs in Hong Kong: Implications for ozone formation [J]. Science of The Total Environment, 2024,912:169156.
[12] 裴成磊,牟江山,张英南,等.广州市臭氧污染溯源:基于拉格朗日光化学轨迹模型的案例分析 [J]. 环境科学, 2021,42(4):1615-1625. Pei C L, Mu J S, Zhang Y N, et al. Source apportionment of ozone pollution in Guangzhou: case study with the application of lagrangianphotochemical trajectory model [J]. Environmental Science, 2021,42(4):1615-1625.
[13] 张鹏辉,胡冬梅,彭 林,等.晋城市大气VOCs污染特征及来源解析 [J]. 中国环境科学, 2023,43(9):4525-4533. Zhang P H, Hu D M, Peng L, et al. Characteristics and sources of atmospheric VOCs pollution in Jincheng [J]. China Environmental Science, 2023,43(9):4525-4533.
[14] Zeng P, Lyu X P, Guo H, et al. Causes of ozone pollution in summer in Wuhan, Central China [J]. Environmental Pollution, 2018,241:852- 861.
[15] Xu J, He Y J, Li M Z, et al. A high ozone event over Beijing after the May 2017 Belt and Road Forum [J]. Atmospheric Pollution Research, 2021,12(3):334-344.
[16] Tan Y, Han S W, Chen Y, et al. Characteristics and source apportionment of volatile organic compounds (VOCs) at a coastal site in Hong Kong [J]. Science of The Total Environment, 2021,777: 146241.
[17] Cui L, Zhang Z, Huang Y, et al. Measuring OVOCs and VOCs by PTR-MS in an urban roadside microenvironment of Hong Kong: relative humidity and temperature dependence, and field intercomparisons [J]. Atmospheric measurement techniques, 2016,9 (12):5763-5779.
[18] De Gouw J, Warneke C. Measurements of volatile organic compounds in the earth's atmosphere using proton-transfer-reaction mass spectrometry [J]. Mass spectrometry reviews, 2007,26(2):223-257.
[19] McKeen S A, Liu S C, Hsie E Y, et al. Hydrocarbon ratios during PEM-WEST A: A model perspective [J]. Journal of Geophysical Research: Atmospheres, 1996,101(D1):2087-2109.
[20] Liu B S, Gu Y, Wu Y T, et al. Review of source analyses of ambient volatile organic compounds considering reactive losses: methods of reducing loss effects, impacts of losses, and sources [J]. Atmospheric Chemistry and Physics, 2024,24(22):12861-12879.
[21] 张英南,薛丽坤,陈天舒,等.基于观测的模型(OBM)的发展历程及其在我国大气化学研究中的应用与展望 [J]. 环境科学研究, 2022, 35(3):621-632. Zhang Y N, Xue L K, Chen T S, et al. Development history of observation-based Model (OBM) and its application and prospect in atmospheric chemistry studies of China [J]. Research of Environmental Sciences, 2022,35(3):621-632.
[22] Liu TT, Hong Y W, Li M R, et al. Atmospheric oxidation capacity and ozone pollution mechanism in a coastal city of southeastern China: analysis of a typical photochemical episode by an observation-based model [J]. Atmospheric Chemistry and Physics, 2022,22(3):2173- 2190.
[23] Dodge M C. Combined use of modeling techniques and smog chamber data to derive ozone-precursor relationships [C] // International conference on photochemical oxidant pollution and its control: Proceedings. US Environmental Protection Agency, Environmental Sciences Research Laboratory Research Triangle Park, NC, 1977,2: 881-889.
[24] 黄继章,高 健,余美芳,等.广州市2022年臭氧污染特征与成因分析 [J]. 中国环境科学, 2024,44(6):3100-3110. Huang J Z, Gao J, Yu M F, et al. Analysis of characteristics and cause of ozone pollution in Guangzhou in 2022 [J]. China Environmental Science, 2024,44(6):3100-3110.
[25] Chen D Y, Zhou L, Wang C, et al. Characteristics of ambient volatile organic compounds during spring O3 pollution episode in Chengdu, China [J]. Journal of Environmental Sciences, 2022,114:115-125.
[26] Carter W P L. Development of the SAPRC-07 chemical mechanism [J]. Atmospheric Environment, 2010,44(40):5324-5335.
[27] Atkinson R, Arey J. Atmospheric degradation of volatile organic compounds [J]. Chemical reviews, 2003,103(12):4605-4638.
[28] Shan W P, Yin Y Q, Lu H X, et al. A meteorological analysis of ozone episodes using HYSPLIT model and surface data [J]. Atmospheric Research, 2009,93(4):767-776.
[29] 林尤静,颜为军,徐文帅,等.海南区域背景点光化学污染特征及VOCs来源解析 [J]. 中国环境科学, 2024,44(5):2418-2430. Lin Y J, Yan W J, Xu W S, et al. Characteristics of photochemical pollution and sources analysis of atmospheric volatile organic compounds in the regional background station of Hainan [J]. China Environmental Science, 2024,44(5):2418-2430.
[30] Wang H, Lyu X P, Guo H, et al. Ozone pollution around a coastal region of South China Sea: interaction between marine and continental air [J]. Atmospheric Chemistry and Physics, 2018,18(6):4277-4295.
[31] He C, Lu X, Wang H L, et al. The unexpected high frequency of nocturnal surface ozone enhancement events over China: characteristics and mechanisms [J]. Atmospheric Chemistry and Physics, 2022,22(23):15243-15261.
[32] 麦健华,于玲玲,邓 涛,等.海陆风对环珠江口地区臭氧污染的影响 [J]. 中国环境科学, 2025,45(3):1198-1209. Mai J H, Yu L L, Deng T, et al. Impact of sea-land breezes on the ozone pollution over the Pearl River Estuary [J]. China Environmental Science, 2025,45(3):1198-1209.
[33] Yu D, Tan Z F, Lu K D, et al. An explicit study of local ozone budget and NOx-VOCs sensitivity in Shenzhen China [J]. Atmospheric Environment, 2020,224:117304.
[34] Kovač-Andrić E, Radanović T, Topalović I, et al. Temporal variations in concentrations of ozone, nitrogen dioxide, and carbon monoxide at Osijek, Croatia [J]. Advances in Meteorology, 2013,2013(1):469786.
[35] 王 玫,郑有飞,柳艳菊,等.京津冀臭氧变化特征及与气象要素的关系 [J]. 中国环境科学, 2019,39(7):2689-2698. Wang M, Zheng Y F, Liu Y J, et al. Characteristics of ozone and its relationship with meteorological factors in Beijing-Tianjin-Hebei Region [J]. China Environmental Science,2019,39(7):2689-2698.
[36] Ma W, Feng Z M, Zhan J L, et al. Influence of photochemical loss of volatile organic compounds on understanding ozone formation mechanism [J]. Atmospheric Chemistry and Physics, 2022,22(7): 4841-4851.
[37] Li Y, Ye C, Ma X F, et al. Radical chemistry and VOCs-NOx- O3-nitrate sensitivity in the polluted atmosphere of a suburban site in the North China Plain [J]. Science of The Total Environment, 2024, 947:174405.
[38] Liu Y, Yuan B, Li X, et al. Impact of pollution controls in Beijing on atmospheric oxygenated volatile organic compounds (OVOCs) during the 2008 Olympic Games: observation and modeling implications [J]. Atmospheric Chemistry and Physics, 2015,15(6):3045-3062.
[39] Xie X, Shao M, Liu Y, et al. Estimate of initial isoprene contribution to ozone formation potential in Beijing, China [J]. Atmospheric Environment, 2008,42(24):6000-6010.
[40] 谢晓栋,胡建林,张远航.我国臭氧污染研究热点与趋势的文献计量分析 [J]. 中国环境科学, 2024,44(12):6513-6521. Xie X D, Hu J L, Zhang Y H, et al. Research topic and trend analysis of ozone pollution in China based on bibliometric review [J]. China Environmental Science, 2024,44(12):6513-6521.
基金
山东省自然科学基金资助项目(ZR2022QD111);国家自然科学基金资助项目(22106081)
PDF(2570 KB)
京公网安备 11010802030352号 
