【作者】 邹宇； 邓雪娇； 王伯光； 李菲；

【机构】 中国气象局广州热带海洋气象研究所； 暨南大学环境工程系；

【摘要】 挥发性有机物(VOCs)是臭氧光化学反应形成的重要前提物质。因此,研究VOCs的变化特征及来源是非常有意义的。2011年5月～2012年5月在广州番禺大气成分站测定环境空气中VOCs,分析VOCs浓度变化规律及组成特征。同时为了更好的鉴别VOCs来源,对采样点附近的工业源、不同VOCs物种的化学生命周期和气象条件等因素进行综合考虑,同时结合分子标志物、后向轨迹模型来探索采样点VOCs的来源。结果表明:VOCs浓度月变化范围40.99ppbv～65.40ppbv,月平均浓度47.95ppbv。气象因素影响VOCs浓度变化,当风向为东东北风和西南风并且风速较低时,有利于采样点VOCs浓度的积累。温度与VOCs浓度呈负相关关系。采样点VOCs的组成特征与工业城市东莞相似。对采样点VOCs来源的分析中,通过异戊二烯与机动车标志性物质3—甲基戊烷和顺式二丁烯线性比对、温度与异戊二烯线性比对和异戊二烯的日变化规律三种方法说明异戊二烯是来源于当地植物排放,而通过VOCs物质的化学生命周期、传输时间和风向判定采样点BTEX(苯、甲苯、乙苯和间对二甲苯)是来源于东部城市东莞的工业排放。不同气团对VOCs的组成特征有影响,经过东莞的气团,芳香烃的比例较高,而来自海洋的气团,烯烃的比例比芳香烃高。在VOCs三类组分周末效应的分析中,芳香烃的周末效应最明显,其次是烷烃,烯烃没有表现出周末效应。通过标志性VOCs物种工作日与非工作日的差异,说明工业的排放和溶剂的挥发是采样点产生周末效应的主要原因。更多还原

【Abstract】 Because Volatile organic compounds(VOCs) are important precursors for ozone photochemical formation,researching the characterizations and sources of VOCs is very rewarding.VOCs were measured from March 2011 to March 2012 in Pan Yu Atmospheric Composition Station,Guangzhou with the purpose of analyzing characterizations and sources of VOCs.At the same time,in order to better analyze the sources of VOCs,the industrial sites around the sampling site,different VOCs chemical life and meteorological condition need to be comprehensive considered.The results show that the monthly concentration variation of VOCs ranges from 40.99ppbv to 65.40ppbv and its monthly average concentration is 47.95ppbv.Meteorological factors have an effect on concentrations of VOCs,especially when the wind directions are ENE and SW and the wind speeds are relatively slow,which contribute to the accumulation of VOCs in sampling site.The temperature has an anti-relation with the concentration of VOCs.VOCs composition characterizations in sampling site is similar to the industrial city Dongguan.In the analysis of sources of VOCs in sampling site,isoprene is emitted from the local vegetation by three methods(Scatter plots for isoprene versus 3-methylpentane,cis-2-Butene,temperature and diurnal variation of isoprene) and BTEX(benzene,toluene,ethyl benzene,m/p-xylene) are emitted from industries in the eastern city Dongguan which can be judged from chemical lifetime,transport time and wind direction.Different air parcels have an effect on composition characterizations of VOCs with the large proportion of aromatics when the air parcel went through Dongguan and with the large ratio of alkenes when the air parcel came from ocean.In the analysis of weekend effect in three categories of VOCs,aromatics have the strongest weekend effect,secondly alkanes,alkenes have no weekend effect.Through the difference between weekend and weekday of some remarkable substances,it’s concluded that industry emission and volatile solvent are major factories for weekend effect.更多还原