Wang Gehui, Kawamura Kimitaka, Xie Mingjie, Hu Shuyuan, Cao Junji, An Zhisheng, Waston John G, Chow Judith C
State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xian 710075, China.
Environ Sci Technol. 2009 Sep 1;43(17):6493-9. doi: 10.1021/es803086g.
Size-segregated aerosol samples were collected in urban Nanjing, China during summer and autumn of 2007 including a period of hazy days during June 1-5. Organic aerosols in the haze event were characterized by elevated concentrations of levoglucosan, high molecular weight (HMW) n-alkanes, and HMW fatty acids due to the emissions from field burning of wheat straw. In contrast, organic aerosols on nonhazy days were characterized by a predominance of fossil fuel combustion products. Levoglucosan (4030 n g m(-3)), n-alkanes (1520 ng m(-3)), fatty acids (2629 ng m(-3)), and PAHs (57 ng m(-3)) in the haze samples were 3-40 times more abundant than those in nonevent samples. Approximately 30-90% ofthe organics during the haze period can be attributed to wheat straw burning. Concentrations of particulate material (PM) mass, n-alkanes, and low molecular weight (LMW) PAHs showed a unimodal size distribution, peaking at 0.7-1.1 microm during the hazy days, and a bimodal distribution, peaking at 0.7-1.1 microm and 4.7-5.8 microm during nonhazy days. The geometric mean diameters (GMDs) of organic aerosols are larger in the fine mode (<2.1 microm) during the hazy days, suggesting aerosols emitted from the wheat straw burning are larger than those from fossil fuel combustion, and fine particle coagulation and organic compound repartitioning were enhanced.
2007年夏秋季节，在中国南京市区采集了按粒径分类的气溶胶样本，其中包括6月1日至5日的一段雾霾天。由于麦秸田间焚烧排放，雾霾事件中的有机气溶胶具有左旋葡聚糖、高分子量（HMW）正构烷烃和HMW脂肪酸浓度升高的特征。相比之下，非雾霾天的有机气溶胶以化石燃料燃烧产物为主。雾霾样本中的左旋葡聚糖（4030 ng m(-3)）、正构烷烃（1520 ng m(-3)）、脂肪酸（2629 ng m(-3)）和多环芳烃（PAHs，57 ng m(-3)）比非事件样本中的含量高3至40倍。雾霾期间约30 - 90%的有机物可归因于麦秸燃烧。颗粒物（PM）质量、正构烷烃和低分子量（LMW）多环芳烃的浓度呈单峰粒径分布，在雾霾天峰值出现在0.7 - 1.1微米，在非雾霾天呈双峰分布，峰值出现在0.7 - 1.1微米和4.7 - 5.8微米。雾霾天细模态（<2.1微米）有机气溶胶的几何平均直径（GMDs）更大，这表明麦秸燃烧排放的气溶胶比化石燃料燃烧排放的气溶胶更大，并且细颗粒凝聚和有机化合物重新分配得到增强。
