我国机动车和燃油锅炉颗粒有机物排放特征

颗粒有机物是大气污染物的重要成分,对人体健康、雾霾形成具有重要影响。化石燃料燃烧是其最主要的来源之一。本研究选取我国不同燃油类型的机动车和燃油锅炉,利用稀释通道法采集了机动车及锅炉运行中排放的细颗粒物,并利用柱前衍生化GC-MS方法分析了其有机成分。在定量分析的约195种有机化合物中,机动车排放的理想示踪物霍烷和甾烷类物质均可被检出;芘/苯并a]芘的值、苯并ghi]苝和晕苯可以用来区分汽油车和柴油车排放;燃油锅炉排放的正构烷烃、正构烷酸、正构烷醇和多环芳烃与柴油车排放有相似之处,在颗粒物源解析研究中应单独考虑,否则可能会高估机动车的贡献;芳香酸可以用来区分燃油锅炉和其他污染源。与国外有机污染物排放源谱相比,我国机动车排放因子偏高,不同类别机动车排放因子具有较大差异。相同工况条件下,燃油类型对燃油锅炉排放因子有着较大影响。基于上述分析建立了我国不同类型机动车和燃油锅炉排放颗粒有机物的源成分谱。

Characters of Airborne Particular Matter from Vehicular Exhausts and Oil-Powered Boiler Emissions

Particulate organic matter (POM), generated primarily from fossil fuel burning, is an important ingredient in air pollution, significantly impacts on human health, and contributes to haze. In this study, particulate matter (PM) from vehicular exhaust and oil-powered boiler emissions was collected by bench test and dilution tunnel, respectively, then POM was analyzed by GC-MS with pre-column derivatization method. In total, nearly 195 organic species were identified, including hopanoids and steranes, the tracers of combustion of fossil fuels. Our results suggest that the ratio of PYR to BaPYR, as well as the concentrations of COR and BghiP can be used to distinguish between gasoline and diesel powered vehicular emissions. We also found that the emissions of n-alkanes, n-alkanoic acids, n-alkanols and PAHs were similar between oil-power boiler emissions and diesel power vehicular emissions. This finding suggests that recent research may overestimate the source contribution of vehicular emissions by ignoring emissions from oil-powered boilers. Aromatic acids could be used as the tracer of oil-power boiler combustion. The emission factor of vehicle, influenced by its categories, was higher in China than other countries overall. The types of fuel in our study had a large impact on the emission factors of oil-powered boilers. The source profiles of vehicle and oil-powered boiler emissions were built based on discussion above.