夏季北海市大气烷烃类挥发性有机物变化特征及来源解析  

Variation characteristics and source analysis of alkane volatile organic compounds in ambient air in Beihai City during summer

作　　者：吴琴琴 吴影 陈福坤[1] 张丽微[1] WU Qinqin;WU Ying;CHEN Fukun;ZHANG Liwei(Guangxi Eco-engineering Vocational and Technical College,Liuzhou 545004,Guangxi,China;Research Institute of Environmental Protection of Guangxi Zhuang Autonomous,Nanning 530022,China)

机构地区：[1]广西生态工程职业技术学院,广西柳州545004 [2]广西壮族自治区环境保护科学研究院,南宁530022

出　　处：《安全与环境学报》2025年第4期1609-1621,共13页Journal of Safety and Environment

基　　金：2023年度广西高校中青年教师科研基础能力提升项目(2023KY1269)。

摘　　要：北海市是广西北部湾城市群典型的沿海城市,研究在2022年夏季对烷烃类挥发性有机物进行了观测,共测量了29种烷烃类挥发性有机物。观测发现,北海市夏季烷烃类挥发性有机物的平均体积分数为1.875×10-9,不同烷烃日出峰情况不同,每日出现3~7个峰不等;各烷烃间相关性与含C数、烷烃结构、来源占比相关,含C数相近且来源构成相似的烷烃,相关性较高。研究利用一级反应动力学估算烷烃类有机物寿命,发现其平均反应速率常数为(0.23±0.17) h-1,平均寿命为(10.73±22.59) h。利用正定矩阵因子分解模型(Positive Matrix Factorization, PMF)进行来源解析发现,北海市夏季烷烃类挥发性有机物主要来源于油气挥发(35.9%)、汽油车排放(28.9%)、溶剂使用(23.3%)、柴油车船排放(6.5%)和燃烧(5.3%)。其中,溶剂使用是北海市夏季烷烃类挥发性有机物中的臭氧生成潜势估算(Ozone Formation Potential, OFP)最大贡献源,占比为39.70%;次要贡献源包括汽油车排放、油气挥发源、柴油车船排放源和燃烧源,贡献率分别为24.50%、18.87%、10.58%和6.35%。Beihai City is a typical coastal city in the Beibei Bay city cluster of Guangxi.In the summer of 2022,the observation study of alkane volatile organic compounds was carried out,and a total of 29 kinds of alkane volatile organic compounds were measured.It is found that the average volume concentration in Beihai City in summer is 1.875×10-9.In terms of proportions,ethane constitutes the largest share,accounting for 24.02%of the total alkanes.Other notable components include propane,isopentane,n-butane,isobutane,and n-pentane,with respective proportions of 14.91%,13.06%,10.50%,6.37%,and 5.69%.The combined proportions of the remaining alkanes are all below 5%.Different alkanes exhibit varying peak patterns,with 3 to 7 peaks appearing daily.The correlation between various alkanes is related to the number of carbon atoms,alkane structure,and source composition.Alkanes with similar carbon numbers and similar source compositions show higher correlations.The lifetime of alkane organic compounds is estimated using first-order reaction kinetics,with an average reaction rate constant of(0.23±0.17)h 1 and an average lifetime of(10.73±22.59)h.Among them,3-methylpentane has the shortest lifetime,which is(3.42±1.43)h.In contrast,ethane has the longest lifetime,with an average of(37.83±34.95)h.According to the source analysis of the PMF receptor model,the main sources of volatile organic compounds in summer in Beihai City are oil and gas volatilization(35.9%),gasoline vehicle emission(28.9%),solvent use(23.3%),diesel vehicle emission(6.5%)and combustion(5.3%).Combining the calculations of Maximum Incremental Reactivity(MIR)to assess the Ozone Formation Potential(OFP)of alkane volatile organic compounds,it is found that solvent usage and gasoline vehicle emissions are the largest contributors to the OFP of alkanes in the summer in Beihai City,accounting for 39.70%and 24.50%respectively.Secondary contributors include oil and gas volatilization,diesel vehicle emissions,and combustion,with contribution rates of 18.87%,10.58%,and

关 键 词：环境学 挥发性有机物 烷烃 正定矩阵因子分解模型 寿命 

分 类 号：X511[环境科学与工程—环境工程]