2021年自贡市O_(3)污染过程VOCs污染特征及来源解析

Analysis of VOCs Pollution Characteristics and Sources of O_(3) Pollution Process in Zigong City in 2021

于2021年6-10月利用CIA-ISQ7000型环境空气VOCs自动在线监测系统,对环境空气中多重类型化合物定性定量分析,分析范围包括117种VOCs(PAMS57种、醛酮类13种、卤代烃类47种),并开展不同O_(3)污染情况下VOCs浓度特征、大气反应活性及来源研究。结果表明,VOCs体积分数浓度范围在(9.2~351.0)×10^(-9)之间,污染日和非污染日VOCs平均体积浓度分别为(133.35±16.12)×10^(-9)和(70.28±18.34)×10^(-9),污染日VOCs浓度较非污染日偏高90%。对于大气反应活性而言,污染日和清洁日VOCs对臭氧生成潜势(Ozone Formation Potential)的贡献均以醛酮类、烷烃类、卤代烃为主,且排名前10的优势物种基本一致,污染日排名前10的物种为乙烷、丙酮、乙炔、氯甲烷、丙烷、萘、甲醛、正丁烷、乙烯、三氯甲烷,非污染日排名前10的物种为乙烷、萘、四氢呋喃、乙炔、丙酮、氯甲烷、丙烷、甲醛、乙烯、三氯甲烷。PMF源解析结果显示,机动车尾气排放、溶剂使用和燃料燃烧为污染日和清洁日VOCs的主要排放源,污染日溶剂使用排放源比非污染日贡献上升了21.4%,这与污染日的高温和强日照有直接联系。建议自贡市应加强6-10月机动车尾气排放、工业涂装、恐龙彩灯制造、印刷和建筑装饰类行业挥发性有机物的综合管控。

From June to October 2021,CIA-ISQ7000 type ambient air VOCs automatic online monitoring system was used to qualitatively and quantitatively analyze multiple types of compounds in ambient air.The analysis scope included 117 VOCs(PAMS57,aldehydes 13,halogenated hydrocarbons 47).The concentration characteristics,atmospheric reactivity and source of VOCs under different O_(3) pollution conditions were studied.The results showed that the VOCs volume fraction concentration range was(9.2~351.0)×10^(-9),and the average volume concentration of VOCs in polluted and non-polluted days was(133.35±16.12)×10^(-9) and(70.28±18.34)×10^(-9),respectively.The VOCs concentration in polluted days was 90% higher than that in non-polluted days.In terms of atmospheric reactivity,aldehydes,alkanes and halogenated hydrocarbons are the main contributions of VOCs to Ozone Formation Potential in pollution days and clean days,and the top 10 dominant species are basically the same.The top 10 species on polluted days were ethane,acetone,acetylene,chloromethane,propane,naphthalene,formaldehyde,n-butane,ethylene,and trichloromethane,while the top 10 species on non-polluted days were ethane,naphthalene,tetrahydrofuran,acetylene,acetone,chloromethane,propane,formaldehyde,ethylene,and trichloromethane.PMF source analysis results showed that vehicle exhaust emissions,solvent use and fuel combustion were the main emission sources of VOCs on pollution days and clean days.Compared with non-pollution days,the contribution of solvent use emission sources on pollution days increased by 21.4%,which was directly related to the high temperature and strong sunshine on pollution days.It is suggested that Zigong City should strengthen the comprehensive control of volatile organic compounds in automobile exhaust emissions,industrial painting,dinosaur lantern manufacturing,printing and building decoration industries from June to October.