Chemical formation and source apportionment of PM2.5 at an urban site at the southern foot of the Taihang mountains

Xiaoyong Liu; Mingshi Wang; Xiaole Pan; Xiyue Wang; Xiaolong Yue; Donghui Zhang; Zhigang Ma; Yu Tian; Hang Liu; Shandong Lei; Yuting Zhang; Qi Liao; Baozhu Ge; Dawei Wang; Jie Li; Yele Sun; Pingqing Fu; Zifa Wang; Hong He

doi:10.1016/j.jes.2020.10.004

Chemical formation and source apportionment of PM_2.5 at an urban site at the southern foot of the Taihang mountains

J Environ Sci (China). 2021 May:103:20-32. doi: 10.1016/j.jes.2020.10.004. Epub 2020 Oct 24.

Authors

Xiaoyong Liu¹, Mingshi Wang², Xiaole Pan³, Xiyue Wang⁴, Xiaolong Yue⁵, Donghui Zhang⁶, Zhigang Ma⁵, Yu Tian⁷, Hang Liu⁷, Shandong Lei⁷, Yuting Zhang⁷, Qi Liao⁷, Baozhu Ge⁸, Dawei Wang⁸, Jie Li⁸, Yele Sun⁸, Pingqing Fu⁹, Zifa Wang¹⁰, Hong He¹¹

Affiliations

¹ Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; University of Chinese Academy of Sciences, Beijing 100049, China.
² Henan Polytechnic University, Jiaozuo 454003, China.
³ State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China. Electronic address: [email protected].
⁴ Jiaozuo Ecological Environment Monitoring Center, Jiaozuo 454003, China. Electronic address: [email protected].
⁵ Jiaozuo Environmental Science Research Institute, Jiaozuo 454003, China.
⁶ Jiaozuo Ecological Environment Monitoring Center, Jiaozuo 454003, China.
⁷ State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; University of Chinese Academy of Sciences, Beijing 100049, China.
⁸ State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.
⁹ Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China.
¹⁰ Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; College of Earth Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
¹¹ Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.

PMID: 33743902
DOI: 10.1016/j.jes.2020.10.004

Abstract

The region along the Taihang Mountains in the North China Plain (NCP) is characterized by serious fine particle pollution. To clarify the formation mechanism and controlling factors, an observational study was conducted to investigate the physical and chemical properties of the fine particulate matter in Jiaozuo city, China. Mass concentrations of the water-soluble ions (WSIs) in PM_2.5 and gaseous pollutant precursors were measured on an hourly basis from December 1, 2017, to February 27, 2018. The positive matrix factorization (PMF) method and the FLEXible PARTicle (FLEXPART) model were employed to identify the sources of PM_2.5. The results showed that the average mass concentration of PM_2.5 was 111 μg/m³ during the observation period. Among the major WSIs, sulfate, nitrate, and ammonium (SNA) constituted 62% of the total PM_2.5 mass, and NO₃^- ranked the highest with an average contribution of 24.6%. NH₄⁺ was abundant in most cases in Jiaozuo. According to chemical balance analysis, SO₄^2-, NO₃^-, and Cl^- might be present in the form of (NH₄)₂SO₄, NH₄NO₃, NH₄Cl, and KCl. The liquid-phase oxidation of SO₂ and NO₂ was severe during the haze period. The relative humidity and pH were the key factors influencing SO₄^2- formation. We found that NO₃^- mainly stemmed from homogeneous gas-phase reactions in the daytime and originated from the hydrolysis of N₂O₅ in the nighttime, which was inconsistent with previous studies. The PMF model identified five sources of PM_2.5: secondary origin (37.8%), vehicular emissions (34.7%), biomass burning (11.5%), coal combustion (9.4%), and crustal dust (6.6%).

Keywords: Chemical components; PM(2.5); Source identification.

Publication types

Observational Study

MeSH terms

Aerosols / analysis
Air Pollutants* / analysis
China
Cities
Environmental Monitoring
Particulate Matter / analysis
Seasons
Vehicle Emissions / analysis

Substances

Aerosols
Air Pollutants
Particulate Matter
Vehicle Emissions