大气挥发性有机物污染特征及源解析——以“2+26”城市之一濮阳市为例

Pollution characteristics and source analysis of atmospheric VOCs:taking Puyang,one of the“2+26”cities,as an example

依据“2+26”城市之一濮阳市2021年大气挥发性有机物(VOCs)监测结果,对VOCs进行污染特征分析、臭氧生成潜势分析以及污染来源解析。研究表明:濮阳市大气VOCs中组分占比表现为烷烃>烯烃>芳香烃>炔烃。乙烷、丙烷、乙烯、正己烷、乙炔、异丁烷、正丁烷、异戊烷、甲苯、苯、甲醛、乙醛等浓度水平较高。根据臭氧生成贡献分析,烷烃是浓度水平较高的组分,但臭氧生成活性较小;而烯烃和芳香烃相比烷烃是浓度水平较低的组分,但对臭氧生成活性较高。臭氧生成关键活性组分是乙烯、间/对二甲苯、甲苯、甲醛、乙醛、己醛等。濮阳市的臭氧生成对VOCs浓度比较敏感。VOCs关键物种的浓度水平随风向变化表现出一定的变化特征。濮阳市大气VOCs有5种主要污染来源,分别为移动源、燃烧源、石油化工源、溶剂使用源和天然排放源,其中移动源贡献较大。VOCs中苯系物来源主要与石油化工生产、化石燃料燃烧有关。

According to the monitoring results of atmospheric VOCs in Puyang in 2021,one of the“2+26”cities,the pollution characteristics,ozone generation potential and pollution sources of VOCs were analyzed.The research showed that:the proportion of each component was alkane>olefin>aromatic hydrocarbon>alkyne.The concentration levels of ethane,propane,ethylene,n-hexane,acetylene,isobutane,n-butane,isopentane,toluene,benzene,formaldehyde and acetaldehyde were relatively high.According to the analysis of contribution to ozone generation,alkanes were the components with higher concentrations and less ozone generation activity,while olefins and aromatic hydrocarbons were components with lower concentrations and high ozone generation activity.The key active substances were ethylene,m/p-xylene,toluene,formaldehyde,acetaldehyde and hexanal.The formation of ozone in Puyang was sensitive to the concentration of VOCs.The concentration level of VOCs key substances with wind direction showed certain variation characteristics.There were five main pollution sources of atmospheric VOCs in Puyang,including mobile sources,combustion sources,petrochemical sources,solvent use sources and natural emission sources,among which mobile sources contribute the most.The pollution sources of benzene series in VOCs were mainly related to petrochemical production and fossil fuel combustion.