| Title | Direct observations of organic aerosols in common wintertime hazes in North China: insights into direct emissions from Chinese residential stoves |
| Authors | Chen, Shurui Xu, Liang Zhang, Yinxiao Chen, Bing Wang, Xinfeng Zhang, Xiaoye Zheng, Mei Chen, Jianmin Wang, Wenxing Sun, Yele Fu, Pingqing Wang, Zifa Li, Weijun |
| Affiliation | Shandong Univ, Environm Res Inst, Jinan 250100, Shandong, Peoples R China. Chinese Acad Meteorol Sci, Key Lab Atmospher Chem, Beijing 100081, Peoples R China. Peking Univ, Coll Environm Sci & Engn, State Key Joint Lab Environm Simulat & Pollut Con, Beijing 100871, Peoples R China. Fudan Univ, Shanghai Key Lab Atmospher Particle Pollut & Prev, Dept Environm Sci & Engn, Shanghai 200433, Peoples R China. Chinese Acad Sci, Inst Atmospher Phys, State Key Lab Atmospher Boundary Layer Phys & Atm, Beijing 100029, Peoples R China. |
| Keywords | EAST-ASIAN OUTFLOW MASS-SPECTROMETRY BROWN CARBON ATMOSPHERIC PARTICLES COAL COMBUSTION MIXING STATE TAR BALLS BIOMASS PLAIN POLLUTION |
| Issue Date | 2017 |
| Publisher | ATMOSPHERIC CHEMISTRY AND PHYSICS |
| Citation | ATMOSPHERIC CHEMISTRY AND PHYSICS.2017,17(2),1258-1270. |
| Abstract | Many studies have focused on the physicochemical properties of aerosol particles in unusually severe haze episodes in North China instead of the more frequent and less severe hazes. Consistent with this lack of attention, the morphology and mixing state of organic matter (OM) particles in the frequent light and moderate (L & M) hazes in winter in the North China Plain (NCP) have not been examined, even though OM dominates these fine particles. In the present work, morphology, mixing state, and size of organic aerosols in the L & M hazes were systematically characterized using transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy, atomic force microscopy, and nanoscale secondary ion mass spectrometer, with the comparisons among an urban site (Jinan, S1), a mountain site (Mt. Tai, S2), and a background island site (Changdao, S3) in the same hazes. Based on their morphologies, the OM particles were divided into six different types: spherical (type 1), near-spherical (type 2), irregular (type 3), domelike (type 4), dispersed-OM (type 5), and OM-coating (type 6). In the three sampling sites, types 1-3 of OM particles were most abundant in the L & M hazes and most of them were internally mixed with non-OM particles. The abundant near-spherical OM particles with higher sphericity and lower aspect ratio indicate that these primary OM particles formed in the cooling process after polluted plumes were emitted from coal combustion and biomass burning. Based on the Si-O-C ratio in OM particles, we estimated that 71% of type 1-3 OM particles were associated with coal combustion. Our result suggests that coal combustion in residential stoves was a widespread source from urban to rural areas in NCP. Average OM thickness which correlates with the age of the air masses in type 6 particles only slightly increased from S1 to S2 to S3, suggesting that the L & M hazes were usually dry (relative humidity < 60 %) with weak photochemistry and heterogeneous reactions between particles and gases. We conclude that the direct emissions from these coal stoves without any pollution controls in rural areas and in urban outskirts contribute large amounts of primary OM particles to the regional L & M hazes in North China. |
| URI | http://hdl.handle.net/20.500.11897/475579 |
| ISSN | 1680-7316 |
| DOI | 10.5194/acp-17-1259-2017 |
| Indexed | SCI(E) |
| Appears in Collections: | 环境科学与工程学院 环境模拟与污染控制国家重点联合实验室 |
