[Analysis of Water Soluble Organic Aerosol in Spring PM2.5 with Soot Particle Aerosol Mass Spectrometry (SP-AMS)]

Wen-Qian Huang; Yan-Tong Chen; Xu-Dong Li; Zhu-Zi Zhao; Shuai-Shuai Ma; Zhao-Lian Ye; Xin-Lei Ge

doi:10.13227/j.hjkx.201907263

[Analysis of Water Soluble Organic Aerosol in Spring PM_2.5 with Soot Particle Aerosol Mass Spectrometry (SP-AMS)]

Huan Jing Ke Xue. 2020 Feb 8;41(2):609-619. doi: 10.13227/j.hjkx.201907263.

[Article in Chinese]

Authors

Wen-Qian Huang¹, Yan-Tong Chen¹, Xu-Dong Li¹, Zhu-Zi Zhao¹, Shuai-Shuai Ma¹, Zhao-Lian Ye¹, Xin-Lei Ge²

Affiliations

¹ School of Chemical and Environmental Engineering, Jiangsu University of Technology, Changzhou 213001, China.
² Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Science and Engineering, Nanjing University of Information Science&Technology, Nanjing 210044, China.

PMID: 32608719
DOI: 10.13227/j.hjkx.201907263

Abstract

To investigate the chemical composition and pollution characteristics of spring fine particles (PM_2.5) in Changzhou, a total of 84 PM_2.5 samples were collected from March 1st to May 30th, 2017. We measured and analyzed conventional components, such as water-soluble ions (WSIIs) and carbonaceous components (OC and EC). The water-soluble organic aerosol (WSOA) was also analyzed by an aerodyne soot particle aerosol mass spectrometer (SP-AMS). During the sampling period, the average daily PM_2.5 concentration was 101.97 μg·m^-3, with more than 73.8% sampling days exceeding the Target-2 standard of the national ambient air quality standard of China. The air quality during the sampling period was dominated by light, moderate, and heavy pollution, accounting for 39.3%, 21.4%, and 13.1% of the total days, respectively. The total WSIIs accounted for 39.86% of PM_2.5 mass, of which secondary ions (SO₄^2-, NH₄⁺, and NO₃^-) accounted for 81.85% of the total WSIIs. The slope of the linear fitted line of the anion and cation charge balance (AE/CE) was greater than 1 (1.09), which indicated that PM_2.5 was weakly acidic. The average OC/EC ratio was 2.53, indicating that PM_2.5 was influenced by the secondary conversion. WSOA included C_xH_y⁺(32.1%), C_xH_yO⁺(30.4%), C_xH_yO₂⁺(25.4%), and H_yO⁺(4.7%) identified by SP-AMS. The average oxygen-to-carbon (O/C), hydrogen-to-carbon (H/C), nitrogen-to-carbon (N/C), and organic matter-to-organic carbon (OM/OC) ratios of the WSOA were 0.72, 1.53, 0.04, and 2.15, respectively. Higher O/C indicated higher contributions from secondary photochemical reaction conversion in spring. Positive matrix factorization (PMF) analysis for AMS mass spectra of WSOA identified three sources, namely hydrocarbon-like (HOA), semi-volatile oxygenated OA (SVOOA)-biomass burning OA (BBOA), and low-volatility oxygenated OA (LVOOA), which on average accounted for 18.4%, 34.1%, and 47.4% of the total WSOA, respectively.

Keywords: fine particle (PM2.5); positive matrix factorization (PMF); soot particle aerosol mass spectrometer (SP-AMS); source apportionment; water-soluble organic aerosol (WSOA).

Publication types

English Abstract