摘要
基于西安市超级站重污染时段(2018年12月30日—2019年1月15日)在线连续观测数据,分析了两个污染过程(污染过程Ⅰ:2018年12月30日—2019年1月7日;污染过程Ⅱ:2019年1月8日—1月15日)VOCs特征、老化程度及日变化;利用正交矩阵因子分解法(PMF)解析了重污染期间VOCs来源;通过气溶胶生成系数法(FAC)估算了二次有机气溶胶(SOA)生成潜势。结果表明:污染过程Ⅰ和Ⅱ的体积分数分别为(102.87±31.62)×10^(-9)(、103.57±45.46)×10^(-9),含氧有机物和烷烃二者占比60%以上。与清洁天相比,炔烃的增幅最大,含氧有机物和烷烃增长值最大,烷/乙炔比值在1.0左右,受扩散条件不利影响导致气团老化严重,日变化呈夜高昼低,8时左右有个小高峰特征;PMF模型源解析结果显示VOCs主要来工业源(13.05%)、机动车尾气(27.49%)、溶剂使用源(15.64%)、化石燃烧源(21.38%)、餐饮源(22.43%);通过估算SOA生成潜势,得出芳香烃中的苯系物(BTEX)为SOA污染的主要物质。
The characteristics,aging degree and diurnal variation of VOCs in two pollution processes(pollution process I:from December 30,2018 to January 7,2019;Pollution Process II:from January 8,2019 to January 15,2019)were analyzed,based on the continuous on-line observation data of heavy pollution period at the Xi'an Super Station(December 30,2018-january 15,2019).The sources of VOCs during heavy pollution episode were analyzed by orthogonal matrix factorization(PMF).The formation potential of secondary organic aerosols(SOA)was estimated by the method of aerosol formation coefficient(FAC).Result showed that the concentration of VOCs were(102.87±31.62)×10^(-9),and(103.5±45.46)×10^(-9) in heavy pollution process I and II.The proportion of organic compounds and alkanes was more than 60%.compared with the clean days,alkynes increased the most,oxygen-containing organic compounds and alkanes increased the most,the ratio of alkyl to acetylene was about 1.0,the air mass were old badly because of the adverse influence of diffusion conditions,The diurnal variation was high at night and low at day,with a small peak at about 08:00.The source apportionment results of PMF model showed that VOCs mainly came from industrial sources(13.05%),vehicle exhaust(27.49%),solvent sources(15.64%),fossil fuel sources(21.38%)and food sources(22.43%).By estimating the SOA generation potential,it was concluded that the benzene series compounds(BTEX)in aromatic hydrocarbons were the main substances of SOA pollution.
作者
薛兴钊
陈妙
李顺姬
曹泽磊
杨檬
Xue Xingzhao;Chen Miao;Li Shunji;Cao Zelei;Yang Meng(Xi'an Academy of Environmental Protection Sciences,Xi'an Shannxi 710062,China)
出处
《环境与发展》
2024年第1期71-78,共8页
Environment & Development
基金
国家重点研发计划重点专项课题(2017YFC0212204)。
