Optical properties and source identification of black carbon and brown carbon: comparison of winter and summer haze episodes in Xi'an, Northwest China

doi:10.1039/c9em00320g

	Optical properties and source identification of black carbon and brown carbon: comparison of winter and summer haze episodes in Xi'an, Northwest China
	Zhang, Qian 1,4; Shen, Zhenxing 1; Lei, Yali 1; Zhang, Tian 1; Zeng, Yaling 1; Ning, Zhi 5; Sun, Jian 1; Westerdahl, Dane 5; Xu, Hongmei 1; Wang, Qiyuan 2
刊名	ENVIRONMENTAL SCIENCE-PROCESSES & IMPACTS
	2019-12-01
卷号	21 期号:12 页码:2058-2069
ISSN号	2050-7887
DOI	10.1039/c9em00320g
通讯作者	Shen, Zhenxing(zxshen@mail.xjtu.edu.cn) ; Zhang, Renjian(zrj@mail.iap.ac.cn)
英文摘要	Summer and winter fine particulate matter (PM2.5) samples were collected to provide insight into the seasonal variations of the optical properties and source profiles of PM2.5 black carbon (BC) and brown carbon (BrC) in Xi'an, China. The average PM2.5 mass concentration during the winter haze (WH) period was 292.5 mu g m(-3), which was 2.6, 5.0 and 9.2 times higher than that during winter non-haze (WNH), summer haze (SH), and summer non-haze (SNH) periods, respectively. Regarding optical properties, the PM2.5 chemical-derived light extinction coefficient was the highest during the WH period (1019.2 Mm(-1)) and decreased by approximately one-fourth in the SH period (237.6 Mm(-1)). During the WH period, the light absorption coefficient of BC (b(abs)-BC) was considerably higher than that during the SH period; this is attributable to the thick coatings of inorganic ions on BC and intensive fossil fuel and biomass burning emissions in winter. Source apportionment also proved that fossil fuels were the major emission source of BC in SH and WH periods with high light absorption coefficient b(abs)_FF (fossil fuel) fractions (>70%). Biomass burning contributed to 25.8% of BC in the winter haze period, but to only 5.4% of BC in the summer haze period. The mass absorption coefficient of BC (MAC-BC) was higher in summer, as it was considerably influenced by vehicle emissions, whereas it was lower in winter due to the strong influences of biomass burning. Moreover, the high light absorption coefficient of BrC (b(abs)-BrC) in both WH and WNH indicated substantial light absorption during winter; however, this coefficient was considerably lower in summer. A remarkable difference in the diurnal pattern of haze between b(abs)-BrC and b(abs)-BC indicated that BC leads to a severe visibility reduction during traffic rush hours. In addition, the BrC abundance observed in Xi'an revealed different diurnal patterns in WH and SH periods, which can be attributed to different secondary formation processes. SH BrC was generally contributed by photochemical-derived secondary organic carbon (SOC) whereas the abundant WH BrC was mainly transformed from aqueous-SOC.
资助项目	National Natural Science Foundation of China[41573101] ; National Natural Science Foundation of China[41877383] ; Natural Science Foundation of Shaanxi Province, China[2016ZDJC-22] ; State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, CAS[SKLLQG1616] ; China Postdoctoral Science Foundation[2018M643595] ; Natural Science Basic Research Plan in Shaanxi Province of China[2019JQ-177]
WOS关键词	AEROSOL LIGHT-ABSORPTION ; FINE PARTICULATE MATTER ; CHEMICAL-COMPOSITION ; SOURCE APPORTIONMENT ; ORGANIC-CARBON ; SIZE DISTRIBUTION ; ELEMENTAL CARBON ; POLLUTION EVENTS ; GUANZHONG PLAIN ; FOSSIL-FUEL
WOS研究方向	Chemistry ; Environmental Sciences & Ecology
语种	英语
出版者	ROYAL SOC CHEMISTRY
WOS记录号	WOS:000502303700005
资助机构	National Natural Science Foundation of China ; Natural Science Foundation of Shaanxi Province, China ; State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, CAS ; China Postdoctoral Science Foundation ; Natural Science Basic Research Plan in Shaanxi Province of China
内容类型	期刊论文
源URL	[http://ir.ieecas.cn/handle/361006/13082]
专题	中国科学院地球环境研究所
通讯作者	Shen, Zhenxing; Zhang, Renjian
作者单位	1.Xi An Jiao Tong Univ, Dept Environm Sci & Engn, Xian 710049, Shaanxi, Peoples R China 2.Chinese Acad Sci, Inst Earth Environm, Key Lab Aerosol Chem & Phys, Xian, Shaanxi, Peoples R China 3.Chinese Acad Sci, Inst Atmospher Phys, Key Lab Reg Climate Environm Res Temperate East A, Beijing 100029, Peoples R China 4.Xian Univ Architecture & Technol, MOE, Key Lab Northwest Resource Environm & Ecol, Xian 710055, Shaanxi, Peoples R China 5.Hong Kong Univ Sci & Technol, Div Environm & Sustainabil, Hong Kong, Peoples R China
推荐引用方式 GB/T 7714	Zhang, Qian,Shen, Zhenxing,Lei, Yali,et al. Optical properties and source identification of black carbon and brown carbon: comparison of winter and summer haze episodes in Xi'an, Northwest China[J]. ENVIRONMENTAL SCIENCE-PROCESSES & IMPACTS,2019,21(12):2058-2069.
APA	Zhang, Qian.,Shen, Zhenxing.,Lei, Yali.,Zhang, Tian.,Zeng, Yaling.,...&Zhang, Renjian.(2019).Optical properties and source identification of black carbon and brown carbon: comparison of winter and summer haze episodes in Xi'an, Northwest China.ENVIRONMENTAL SCIENCE-PROCESSES & IMPACTS,21(12),2058-2069.
MLA	Zhang, Qian,et al."Optical properties and source identification of black carbon and brown carbon: comparison of winter and summer haze episodes in Xi'an, Northwest China".ENVIRONMENTAL SCIENCE-PROCESSES & IMPACTS 21.12(2019):2058-2069.