摘要
基于大学城站点冬季霾污染时段在线气相色谱连续观测数据,分析了高污染时段VOCs污染特征和不同霾污染情况下VOCs光化学反应活性物种.观测期间共检测到55种VOCs物种(PAMs),735个有效样本,ΣVOCs体积分数范围在25.5×10^(-9)~1 320.3×10^(-9)(avg±SD,240×10^(-9)±181×10^(-9))之间.甲苯和间/对-二甲苯是两个高污染时段的特征污染物,其体积分数超过工业区边界站的体积分数,且高污染时段与工业区站点有相似的组分特征,可能受到附近工业区影响较大.VOCs组分小时变化呈现夜间高白天低的特点,臭氧的小时体积分数变化与之相反.通过分析污染物的光化学反应活性,芳香烃对OFP的贡献率最高,达到70.0%,其次是烯炔烃(16.7%).西北风向的OFP值为2 078.2×10^(-9),是其他风向的4倍,平均MIR值也高于本市其他工业区点位;该地区不同程度霾污染下芳烃均是OFP贡献的主导污染物,其中,甲苯和间/对-二甲苯的贡献率之和超过50%.应用PMF5.0对污染物进行来源解析,得到4个因子,分别为含汽油污染源及机动车尾气排放、石油炼制加工、溶剂使用、有机合成材料制造;其贡献率分别为:33.1%、31.5%、30.5%、4.9%.
Based on the online measurements of VOCs of high pollution process at the university site in winter,VOCs＇ characteristics and species at different levels of haze pollution were analyzed. Fifty-five VOCs were detected during sampling. Σ55VOCs concentrations ranged between 25. 5 × 10^-9-1 320. 3 × 10^-9（ avg ± SD,240 × 10^-9 ± 181 × 10^-9 ）. Toluene and xylene were the major pollutants during high pollution process,the concentrations of which were higher than those of industrial area. The university site shared a similar VOC composition with that of industrial area,which suggested that it might be influenced by the surrounding industries. VOCs species exhibited high concentrations in nighttime while low concentrations in daytime. The ozone concentrations were on the contrary. Aromatic hydrocarbons were predominant with a high percentage of contribution（ 70. 0%） to OFP（ ozone formation potential）. Alkenes and alkynes were the second highest group（ 16. 7%）. The OFP of VOCs was 2 078. 2 × 10^（-9）under the west-south wind direction,about 4 times higher than the value under other wind directions（ 505. 8 × 10^（-9））. Aromatic hydrocarbons exhibited a predominant contribution to OFP at different levels of haze pollution in this area,among which,Toluene and xylene contributed more than 50% to OFP. The newest version of EPA PMF model was used to identify the major source of VOCs and evaluate their contributions. Gasoline sources and vehicle exhaust,refinery and petroleum products,solvent use and organic synthetic materials were the identified VOC sources in the study area,contributing 33. 1%,31. 5%,30. 5%,and 4. 9%,respectively to the Σ55VOCs concentrations.
作者
高爽
张坤
高松
修光利
程娜
潘研
GAO Shuang ZHANG Kun GAO Song XIU Guang-li CHENG Na PAN Yan(State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Processes, School of Resources ＆ Environmental Engineering, East China University of Science and Technology, Shanghai 200237, China Shanghai Environmental Monitoring Center, Shanghai 200235, China Shanghai High School, Shanghai 200231, China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2017年第3期855-866,共12页
Environmental Science
基金
国家重点研发计划项目(2016YFC0200500)
国家自然科学基金项目(21277044)
