摘要
为探究汾渭平原非采暖期和采暖期大气环境挥发性有机物(VOCs)的污染特征差异及对二次有机气溶胶(SOA)生成的影响因素,本文以运城市为例在城区站点开展了为期5个月(2021年9月−2022年1月)的小时分辨率VOCs连续在线观测实验,采用PMF(Probabilistic Matrix Factorization)源解析模型、随机森林模型和SOA评估等方法,全面对比分析了运城市非采暖期和采暖期VOCs的体积分数、来源差异和对SOAP(SOA生成潜势)的贡献,同时量化了气象和排放因素对TVOCs(总挥发性有机化合物)体积分数整体变化的影响.结果表明:①运城市非采暖期和采暖期TVOCs平均体积分数分别为35.39×10^(-9)±17.79×10^(-9)和59.88×10^(-9)±31.56×10^(-9),表现出采暖期TVOCs体积分数升高的特征.②烷烃和OVOCs(含氧挥发性有机物)为两个时期VOCs的主要组分,燃烧源和工业源在采暖期是VOCs的主要贡献者,相比非采暖期其贡献率分别上升了13.3%和2.7%.③随机森林模型运行结果表明,排放因素对TVOCs体积分数的贡献高于气象因素,其对采暖期TVOCs体积分数的贡献为非采暖期的1.41倍,且采暖期不利的气象因素也促进了TVOCs体积分数的上升.④芳香烃虽然对非采暖期和采暖期TVOCs体积分数的贡献率分别为5.5%和7.0%,但对两个时期SOAP的贡献率分别达85.5%和87.9%,其中间/对-二甲苯、邻-二甲苯和乙苯是对SOAP贡献率较大的物种.研究显示,芳香烃及人为活动的燃烧源分别是运城市采暖期需要VOCs重点管控的组分和潜在来源.
In order to explore the differences in the pollution characteristics of atmospheric volatile organic compounds(VOCs)in the Fenwei Plain during the non-heating and heating periods,and evaluate their impact on the formation of secondary organic aerosols(SOA),a continuous online monitoring system for VOCs with hourly resolution was established.The observation experiment was conducted in the urban area of Yuncheng and lasted for 5 months(from September 2021 to January 2022).The PMF(Probabilistic Matrix Factorization)source apportionment model,random forest model and SOA evaluation method were used to conduct a comprehensive comparative analysis of VOCs concentration levels,source differences and contributions to SOA formation potential(SOAP)during the non-heating and heating periods in Yuncheng.The impact of meteorological and emission factors on the overall change of total volatile organic compounds(TVOCs)concentration was also quantified.The results showed that:(1)The total mixing ratios of TVOCs in the non-heating period and the heating period in Yuncheng were 35.39×10^(-9)±17.79×10^(-9) and 59.88×10^(-9)±31.56×10^(-9) respectively,indicating that TVOCs increased after heating.(2)Alkanes and oxygenated volatile organic compounds(OVOCs)were the main components of VOCs in both periods.During the heating period,combustion sources and industrial sources were the main contributors of VOCs.The contribution proportions increased by 13.3%and 2.7%,respectively,compared with the non-heating period.(3)The result of the random forest model revealed that the contribution of emission factors to TVOCs was greater than that of meteorological factors.The contribution value during the heating period was 1.41 times that of the non-heating period.Unfavorable meteorological factors during the heating period also promoted the increase of TVOCs.(4)Although aromatics accounted for only 5.5%and 7.0%of TVOCs during the non-heating and heating periods respectively,they accounted for 85.5%and 87.9%of SOAP during both periods,of which m/p-xylene,o-xylene,and ethylbenzene were species that contributed most to SOAP.This study shows that aromatics hydrocarbons and anthropogenic emissions combustion sources are the components and potential sources of VOCs that need to be controlled during heating season in Yuncheng City.
作者
唐泽雨
古国红
桂张玲
张欢
阴世杰
闫风雨
刘新罡
刘腾飞
李斌
TANG Zeyu;GU Guohong;GUI Zhangling;ZHANG Huan;YIN Shijie;YAN Fengyu;LIU Xingang;LIU Tengfei;LI Bin(Yuncheng Environmental Protection Bureau,Yuncheng 044000,China;Yuncheng Ecological Environment Protection Comprehensive Administrative Law Enforcement Team,Yuncheng 044000,China;School of Environment,Beijing Normal University,Beijing 100875,China;Beijing Shida Qingtian Environmental Protection Technology Co.,Ltd.,Beijing 101300,China)
出处
《环境科学研究》
CAS
CSCD
北大核心
2024年第4期708-718,共11页
Research of Environmental Sciences
基金
国家重点研发计划项目(No.2023YFC3709500)
“一市一策”驻点跟踪研究项目(No.2211300002)。
