| 春节与疫情管控期间珠三角VOCs的组成和来源变化 |
| 摘要点击 2129 全文点击 710 投稿时间：2021-06-29 修订日期：2021-09-08 |
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| 中文关键词 疫情 珠江三角洲 挥发性有机物(VOCs) 变化特征 大气氧化性 来源 |
| 英文关键词 epidemic Pearl River Delta volatile organic compounds (VOCs) characteristics oxidation sources |
| 作者 | 单位 | E-mail | | 江明 | 广东省生态环境监测中心, 国家环境保护区域空气质量监测重点实验室, 广州 510308 | jm787@139.com | | 袁鸾 | 广东省生态环境监测中心, 国家环境保护区域空气质量监测重点实验室, 广州 510308 | | | 温丽容 | 广东省生态环境监测中心, 国家环境保护区域空气质量监测重点实验室, 广州 510308 | | | 张莹 | 广东省生态环境监测中心, 国家环境保护区域空气质量监测重点实验室, 广州 510308 | | | 方洪波 | 东莞市生态环境监测中心站, 东莞 523000 | | | 杨满芽 | 中山市生态环境监测中心站, 中山 528400 | | | 李成柳 | 壹点环境科技(广州)有限公司, 广州 510220 | willow@szopec.com |
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| 中文摘要 |
| 挥发性有机物（VOCs）是对流层中臭氧（O3）生成过程的关键前体物，是O3与PM2.5协同治理的重要管控对象.基于2020年1月1日~2月29日珠江三角洲（珠三角）4个站点的在线VOCs观测数据，分析了春节与疫情管控期间珠三角地区VOCs组分、活性、臭氧生成潜势和来源的变化.结果表明，春节与疫情管控期间珠三角地区φ（VOCs）的平均值为15.89×10-9，最大小时体积分数平均值为45.43×10-9，较春节放假前分别降低了44%和60%；各VOCs组分的降幅中以芳香烃降幅最大，且珠三角城区降幅（74%）明显大于郊区（56%），使芳香烃对总VOCs的贡献率降低至不足10%.春节与疫情管控期间珠三角地区VOCs与·OH反应的活性（L·OH）及臭氧生成潜势（OFP）均显著下降，珠三角城区总L·OH和总OFP分别较春节放假前平均下降了60%和63%；大气氧化性也明显降低，Ox浓度平均值较春节放假前下降了28%.甲苯/苯的比值显示，春节与疫情管控期间工业源影响基本消失，与工业相关的溶剂使用源代表组分甲苯、乙苯和间/对-二甲苯总体积分数下降了72%~91%.提出了溶剂使用源和机动车尾气排放源是当前珠三角区域O3污染防控需重点关注的VOCs来源，而在进一步降低O3本底浓度工作中不可忽视石化源的影响. |
| 英文摘要 |
| Volatile organic compounds (VOCs) are the key precursors of the ozone (O3) formation processes in the troposphere and are important control objects for the coordinated governance of O3 and PM2.5. The Spring Festival of 2020 was affected by the novel coronavirus (COVID-19) pneumonia epidemic:companies stopped work and production, and traffic was restricted, providing scientific experimentation opportunities for pollutant emission reduction research. This study analyzed the variety of the composition, chemical reaction activity, and sources of VOCs in the Pearl River Delta during the Spring Festival and the epidemic control period, using real-time online monitoring data of VOCs obtained at four sites(Guangzhou, Dongguan, Zhongshan, and Duanfen)in the Pearl River Delta from January 1, 2020 to February 29, 2020. The results showed that during the Spring Festival and the epidemic control period, the average of φ (VOCs) in the Pearl River Delta was 15.89×10-9, and the maximum hourly average concentration was 45.43×10-9, values that were 44% and 60% lower, respectively, than those before the Spring Festival holiday. Among the VOCs component concentration decreases, the aromatic hydrocarbon component decreased the most, and the decrease in the urban area of the Pearl River Delta (74%) was significantly greater than that in the suburban area (56%). As a result, the contribution rate of aromatic hydrocarbons to the total VOCs was reduced to less than 10%. The analysis of the·OH reaction activity of VOCs(L·OH)and ozone formation potential(OFP)showed that the L·OH and OFP of VOCs decreased significantly in the Pearl River Delta during the Spring Festival and the epidemic control period. Compared with those before the Spring Festival holiday, the total L·OH and total OFP decreased by an average of 60% and 63% in the urban area of the Pearl River Delta, respectively. Additionally, the atmospheric oxidation had also been significantly reduced, which showed a 28% decrease in ρ(Ox). The ratio of toluene/benzene showed that the influence of industrial sources had almost disappeared during the Spring Festival and the epidemic control period, and the total points of the representative components of industrial-related solvent-use sources such as toluene, ethylbenzene, and m/p-xylene dropped by 72% to 91%. The results of this study suggest that solvent-use sources and vehicle exhaust emission sources are the current sources of VOCs that need to be paid attention to in the prevention and control of O3 pollution in the Pearl River Delta region, and the impact of petrochemical sources cannot be ignored in the work of further reducing the background concentration of O3. |
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