title: Characteristics of secondary inorganic aerosol and sulfate species in size-fractionated aerosol particles in Shanghai.
abstract: Sulfate, nitrate and ammonium (SNA) are the dominant species in secondary inorganic aerosol, and are considered an important factor in regional haze formation. Size-fractionated aerosol particles for a whole year were collected to study the size distribution of SNA as well as their chemical species in Shanghai. SNA mainly accumulated in fine particles and the highest average ratio of SNA to particulate matter (PM) was observed to be 47% in the fine size fraction (0.49-0.95 μm). Higher sulfur oxidation ratio and nitrogen oxidation ratio values were observed in PM of fine size less than 0.95 μm. Ion balance calculations indicated that more secondary sulfate and nitrate would be generated in PM of fine size (0.49-0.95 μm). Sulfur K-edge X-ray absorption near-edge structure (XANES) spectra of typical samples were analyzed. Results revealed that sulfur mainly existed as sulfate with a proportion (atomic basis) more than 73% in all size of PM and even higher at 90% in fine particles. Sulfate mainly existed as (NH4)2SO4 and gypsum in PM of Shanghai. Compared to non-haze days, a dramatic increase of (NH4)2SO4 content was found in fine particles on haze days only, which suggested the promoting impact of (NH4)2SO4 on haze formation. According to the result of air mass backward trajectory analysis, more (NH4)2SO4 would be generated during the periods of air mass stagnation. Based on XANES, analysis of sulfate species in size-fractionated aerosol particles can be an effective way to evaluate the impact of sulfate aerosols on regional haze formation.
authors: Shanghai Institute of Applied Physics Chinese Academy of Sciences, Shanghai 201800, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: longshilei@sinap.ac.cn.
authors: Shilei
authors: S
authors: Long
authors: Shanghai Institute of Applied Physics Chinese Academy of Sciences, Shanghai 201800, China.
authors: Jianrong
authors: J
authors: Zeng
authors: Shanghai Institute of Applied Physics Chinese Academy of Sciences, Shanghai 201800, China. Electronic address: ly@sinap.ac.cn.
authors: Yan
authors: Y
authors: Li
authors: Shanghai Institute of Applied Physics Chinese Academy of Sciences, Shanghai 201800, China.
authors: Liangman
authors: L
authors: Bao
authors: Shanghai Institute of Applied Physics Chinese Academy of Sciences, Shanghai 201800, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors: Lingling
authors: L
authors: Cao
authors: Shanghai Institute of Applied Physics Chinese Academy of Sciences, Shanghai 201800, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors: Ke
authors: K
authors: Liu
authors: Shanghai Institute of Applied Physics Chinese Academy of Sciences, Shanghai 201800, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors: Liang
authors: L
authors: Xu
authors: Shanghai Institute of Applied Physics Chinese Academy of Sciences, Shanghai 201800, China.
authors: Jun
authors: J
authors: Lin
authors: Shanghai Institute of Applied Physics Chinese Academy of Sciences, Shanghai 201800, China.
authors: Wei
authors: W
authors: Liu
authors: Shanghai Institute of Applied Physics Chinese Academy of Sciences, Shanghai 201800, China.
authors: Guanghua
authors: G
authors: Wang
authors: Shanghai Institute of Applied Physics Chinese Academy of Sciences, Shanghai 201800, China.
authors: Jian
authors: J
authors: Yao
authors: Synchrotron Radiation Laboratory, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
authors: Chenyan
authors: C
authors: Ma
authors: Synchrotron Radiation Laboratory, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
authors: Yidong
authors: Y
authors: Zhao
mesh_terms: D000336:Aerosols; D000393:Air Pollutants / Q000737:chemistry*; D002681:China; D010316:Particle Size; D013431:Sulfates / Q000737:chemistry*; D013997:Time Factors
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D013431:Sulfates
keywords: XANES; haze; particulate matter; sulfate