上海中心城区夏季挥发性有机物(VOCs)的源解析

2006～2008年夏季在上海徐家汇地区对大气中的挥发性有机物(VOCs)进行连续3h采样(6:00～9:00),共取得72个有效样本.同时,应用PCA/APCS(principal component analysis/absolute principal component scores)受体模型对大气中VOCs来源进行了分析.结果表明,上海夏季中心城区大气中VOCs主要有5个来源,分别为交通工具尾气排放、燃料挥发(液化石油气/天然气泄漏和汽油蒸发)、溶剂使用、工业生产和生物质/生物燃料燃烧+海洋源,其贡献率分别为34%、24%、16%、14%、12%.其中,芳香烃主要来自于溶剂使用、交通工具尾气排放、工业生产和燃料挥发,其分担率分别为35%、26%、22%、17%.烯烃主要来自于交通工具尾气排放和燃料挥发,其分担率为49%和40%.烷烃主要来自于交通工具尾气排放、燃料挥发和溶剂使用,其分担率分别为45%、32%、12%.模拟结果和已知源成分谱符合较好,说明PCA/APCS受体模型源解析结果可信.

Source apportionment of VOCs at city centre of Shanghai in summer

VOCs were sampled from 6:00~9:00 am nearly every day from 2006~2008 in Xujiahui-the city centre of Shanghai. A receptor model based on principal component analysis/absolute principal component scores (PCA/APCS) was used to identify the major sources of VOCs and evaluate their contributions. In summer, 34% of the total VOC concentrations were attributed to vehicle related emissions, 24% to fuel evaporation (including LPG/NG leakage and gasoline evaporation), 16% to solvent usage, 14% to industrial production, and 12% to biomass/biofuel burning and ocean sources. For aromatics, 35% was attributed to solvent usage, 26% to vehicle related emissions, 22% to industrial production and 17% to fuel evaporation. For alkenes, vehicle related emissions and fuel evaporation are the main sources, accounting for 49% and 40%, respectively. For alkanes, vehicle related emissions accounted for 45%, fuel evaporation for 32% and solvent usage for 12%. Finally, the simulated values fit the known VOC source profiles, thus the PCA/APCS receptor model is verified.