Abstract：This paper analyzed the morphologies, elemental compositions and sulfuration characteristics of the fine particles collected in Beijing from March to April 2011under different weather conditions by means of Transmission Electron Microscopy (TEM). The fine particles of the dust weather in March 2010and the fog weather samples in November, 2010were also investigated with the same methods. The results showed that particles could be subdivided into 4major morphological categories, including soot aggregates, fly ash, mineral and secondary particles. Particle types have no obvious variation under different weather conditions. According to elemental compositions, mineral particles can be classified into 9categories, namely, “Si-rich” (occupying 46% by number), “Ca-rich” (17%), “S-rich” (13%), “Fe-rich” (7%), “Na-rich” (6%), and other particles including “Ti-rich”, “Al-rich”, “Cl-rich” and “Mg-rich”. The proportion of these different particles in PM10was influenced by weather conditions, with the number percentage of the “Si-rich” particles in dust storm (83%) being obviously higher than those on cloudy day (36%) and foggy day (32%). A higher number of “S-rich” particles were found in the cloudy and foggy days, being 10.7% and 26% respectively, indicating that the cloudy and foggy weather is favorable for secondary reactions and formation of S-rich particles. Sulfuration characteristics analysis of S-containing particles shows that, contain S mineral content differences in different weather, cloudy 16%, fog 36%, and it was barely found in sunny day and dust storm, it shows that at certain SO2concentration, the atmospheric humidity higher, the sulfation is more obvious. The Sulfation on the surface of particles in foggy day is quite serious, in the high sulfur content particles, most also contains Ca, Na, Si and Fe elements, indicating that alkaline mineral in the air which contains Ca, Na, Si and Fe elements have some buffer action to the acid mist.
李泽熙, 邵龙义, 樊景森, 胡颖, 侯聪. 北京市不同天气条件下单颗粒形貌及元素组成特征[J]. 中国环境科学, 2013, 33(9): 1546-1552.
LI Ze-Xi, SHAO Long-Yi, FAN Jing-Sen, HU Ying, HOU Cong. Morphologies and elemental compositions of individual particles under different weather conditions in Beijing. CHINA ENVIRONMENTAL SCIENCECE, 2013, 33(9): 1546-1552.
