大连市臭氧前体物季节变化特征研究

Study on the Seasonal Variation Characteristics of Ozone Precursors in Dalian City

2018~2020年,在大连市开展了城市大气中VOCs(臭氧前体物)的连续自动监测。采用SynSpec GC955-611/811在线气相色谱仪对大连地区VOCs组分进行了监测。结果表明:2018~2020年,大连市环境空气自动监测VOCs平均体积浓度为9.27×10^(-9),体积浓度从高到低为:烷烃>芳香烃>炔烃>烯烃。采用臭氧生成潜势(OFP)计算方法计算了各种VOCs组分和物种的活性水平:2018~2020年,大连市活性浓度为13.22×10^(-9),烷烃和芳香烃的臭氧生成贡献最高。大连市TVOCs体积浓度体现为:秋季高,春季低,烷烃、芳烃和炔烃体积浓度秋季最高。关键VOCs活性物种甲苯、丙烷、正丁烷、间/对二甲苯和异戊烷等排名靠前。

From 2018 to 2020,continuous automatic monitoring of VOCs(ozone precursors)in the urban atmosphere has been carried out in Dalian City.VOCs in Dalian area were monitored by Synspec GC955-611/811 online gas chromatograph.The results show that from 2018 to 2020,the average volume concentration of VOCs automatically monitored in the ambient air in Dalian City is 9.27×10^(-9),and the volume concentration from high to low is alkane>aromatic>alkyne>olenes.Ozone Formation Potential(OFP)calculation method was used to calculate the activity levels of various VOCs components and species.From 2018 to 2020,the active concentration in Dalian City is 13.22×10^(-9),and the contribution of alkanes and aromatic hydrocarbons to ozone generation is the highest.The volume concentration of TVOCs in Dalian City is high in autumn and low in spring,and the volume concentration of alkanes,aromatics and alkynes is the highest in autumn.The key active species of VOCs such as toluene,propane,n-butane,m-xylene and isopentane are ranked high.