为了解长沙市臭氧(O3)污染特征及来源成因,文章基于2023年长沙市环境空气质量国家监测站点和光化学组分监测数据,分析长沙市夏季臭氧浓度变化特征,并对长沙市雨花区的一次持续5天的臭氧污染进行了深入分析。结果表明,2023年8月16~20日...为了解长沙市臭氧(O3)污染特征及来源成因,文章基于2023年长沙市环境空气质量国家监测站点和光化学组分监测数据,分析长沙市夏季臭氧浓度变化特征,并对长沙市雨花区的一次持续5天的臭氧污染进行了深入分析。结果表明,2023年8月16~20日长沙市雨花区出现的一次持续的臭氧污染,主要是在不利气象条件及较高浓度前体物影响下的本地生成和传输影响形成的连续臭氧污染。长沙市雨花区臭氧浓度日变化峰型出现双峰和明显的拖尾峰,说明污染受传输影响较大,可能受较高海拔丘陵以及微环境地形地貌影响,污染易堆积。气象与臭氧污染分析显示夏季臭氧高浓度集中在温度大于33℃、湿度低于70%的时候。在南偏西风方向3级以下风力下,O3出现高值。烷烃和芳香烃的浓度在污染前、污染中和污染后三个阶段的前体物特征变化均最高。前十臭氧生成潜势(OFP)组分中间/对二甲苯、1,2,3-三甲苯和甲苯、异戊烷和正丁烷浓度有明显升高。基于观测的模型分析显示长沙市雨花区目前处在VOCs控制区,芳香烃对臭氧生成影响最大;VOCs源解析结果显示雨花区VCOs来源机动车尾气占比最高,达36.1%,其次为工业排放源,从OFP贡献占比来看,机动车尾气源贡献最大,占比达33.5%,其次为溶剂使用源,占28.4%。Based on the 2023 National Monitoring Station of Environmental Air Quality in Changsha City and the monitoring data of photochemical components, the characteristics of summer ozone concentration changes and 5-day continuous ozone pollution in the Yuhua District of Changsha City were analyzed for exploring the characteristics and causes of ozone (O3) pollution. The results indicate that sustained ozone pollution occurred in Yuhua District, Changsha City from August 16 to 20, 2023, mainly due to local generation and transport effects under adverse meteorological conditions and high concentrations of precursor substances. The daily variation peak pattern of ozone concentration in Yuhua District, Changsha City shows a bimodal and obvious tailing peak, indicating that pollution is greatly affected by transmission and may be influenced by high-altitude hills and micro environmental topography, making pollution prone to accumulation. The correlation analysis between meteorology and ozone pollution shows that high concentrations of ozone in summer are concentrated when the temperature is greater than 33˚C and the humidity is below 70%. Under wind speeds below level 3 in the southwesterly direction, O3 shows a high value. Compared with the changes in the characteristics of precursors before, during, and after pollution, the concentrations of alkanes and aromatics were the highest during the pollution period. The top ten components with significantly increased ozone generation potential (OFP) were m/p-xylene, 1,2,3-trimethylbenzene, and toluene, while the concentrations of isopentane and n-butane increased significantly. Observational model analysis shows that Yuhua District is currently in the VOCs controlled area, with aromatic hydrocarbons having the greatest impact on ozone generation. Sources apportionment of VOC show that the proportion of vehicle exhaust is the highest, reaching 36.1%, followed by industrial emission sources. In terms of the contribution of OFP, the contribution of vehicle exhaust sources is the highest, accounting for 33.5%, followed by solvent use sources, accounting for 28.4%.展开更多
文摘为了解长沙市臭氧(O3)污染特征及来源成因,文章基于2023年长沙市环境空气质量国家监测站点和光化学组分监测数据,分析长沙市夏季臭氧浓度变化特征,并对长沙市雨花区的一次持续5天的臭氧污染进行了深入分析。结果表明,2023年8月16~20日长沙市雨花区出现的一次持续的臭氧污染,主要是在不利气象条件及较高浓度前体物影响下的本地生成和传输影响形成的连续臭氧污染。长沙市雨花区臭氧浓度日变化峰型出现双峰和明显的拖尾峰,说明污染受传输影响较大,可能受较高海拔丘陵以及微环境地形地貌影响,污染易堆积。气象与臭氧污染分析显示夏季臭氧高浓度集中在温度大于33℃、湿度低于70%的时候。在南偏西风方向3级以下风力下,O3出现高值。烷烃和芳香烃的浓度在污染前、污染中和污染后三个阶段的前体物特征变化均最高。前十臭氧生成潜势(OFP)组分中间/对二甲苯、1,2,3-三甲苯和甲苯、异戊烷和正丁烷浓度有明显升高。基于观测的模型分析显示长沙市雨花区目前处在VOCs控制区,芳香烃对臭氧生成影响最大;VOCs源解析结果显示雨花区VCOs来源机动车尾气占比最高,达36.1%,其次为工业排放源,从OFP贡献占比来看,机动车尾气源贡献最大,占比达33.5%,其次为溶剂使用源,占28.4%。Based on the 2023 National Monitoring Station of Environmental Air Quality in Changsha City and the monitoring data of photochemical components, the characteristics of summer ozone concentration changes and 5-day continuous ozone pollution in the Yuhua District of Changsha City were analyzed for exploring the characteristics and causes of ozone (O3) pollution. The results indicate that sustained ozone pollution occurred in Yuhua District, Changsha City from August 16 to 20, 2023, mainly due to local generation and transport effects under adverse meteorological conditions and high concentrations of precursor substances. The daily variation peak pattern of ozone concentration in Yuhua District, Changsha City shows a bimodal and obvious tailing peak, indicating that pollution is greatly affected by transmission and may be influenced by high-altitude hills and micro environmental topography, making pollution prone to accumulation. The correlation analysis between meteorology and ozone pollution shows that high concentrations of ozone in summer are concentrated when the temperature is greater than 33˚C and the humidity is below 70%. Under wind speeds below level 3 in the southwesterly direction, O3 shows a high value. Compared with the changes in the characteristics of precursors before, during, and after pollution, the concentrations of alkanes and aromatics were the highest during the pollution period. The top ten components with significantly increased ozone generation potential (OFP) were m/p-xylene, 1,2,3-trimethylbenzene, and toluene, while the concentrations of isopentane and n-butane increased significantly. Observational model analysis shows that Yuhua District is currently in the VOCs controlled area, with aromatic hydrocarbons having the greatest impact on ozone generation. Sources apportionment of VOC show that the proportion of vehicle exhaust is the highest, reaching 36.1%, followed by industrial emission sources. In terms of the contribution of OFP, the contribution of vehicle exhaust sources is the highest, accounting for 33.5%, followed by solvent use sources, accounting for 28.4%.
