Chemical composition of PM2.5 during winter in Tianjin, China--颗粒学报PARTICUOLOGY

Gu, J., Bai, Z., Li, W., Wu, L., Liu, A., Dong, H., & Xie, Y. (2011). Chemical composition of PM2.5 during winter in Tianjin, China. Particuology, 9(3), 215–221. https://doi.org/10.1016/j.partic.2011.03.001

Chemical composition of PM_2.5 during winter in Tianjin, China

Jinxia Gu ^{a b}, Zhipeng Bai ^b *, Weifang Li ^b, Liping Wu ^{a b}, Aixia Liu ^c, Haiyan Dong ^d, Yiyang Xie ^c

a Tianjin Institute of Urban Construction, Tianjin 300384, China
b State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China
c Tianjin Institute of Meteorological Instruments, Tianjin 300074, China
d Tianjin Environmental Monitoring Central Station, Tianjin 300191, China

10.1016/j.partic.2011.03.001

Volume 9, Issue 3, June 2011, Pages 215-221

Received 13 December 2009, Revised 1 July 2010, Accepted 3 March 2011, Available online 26 March 2011.

E-mail: zbai@nankai.edu.cn

Highlights

Abstract

PM_2.5 samples for 24 h were collected during winter in Tianjin, China. The ambient mass concentration and chemical composition of the PM_2.5 were determined. Ionic species were analyzed by ion chromatography, while carbonaceous species were determined with the IMPROVE thermal optical reflectance (TOR) method, and inorganic elements were measured by inductively coupled plasma-atomic emission spectrometer. The daily PM_2.5 mass concentrations ranged from 48.2 to 319.2 μg/m³ with an arithmetic average of 144.6 μg/m³. The elevated PM_2.5 in winter was mostly attributed to combustion sources such as vehicle exhaust, heating, cooking and industrial emissions, low wind speeds and high relative humidity (RH), which were favorable for pollutant accumulation and formation of secondary pollutants. By chemical mass balance, it was estimated that about 89.1% of the PM_2.5 mass concentrations were explained by carbonaceous species, secondary particles, crustal matters, sea salt and trace elements. Organic material was the largest contributor, accounting for about 32.7% of the total PM_2.5 mass concentrations. SO₄²⁻, NO₃⁻, Cl⁻ and NH₄⁺ were four major ions, accounting for 16.6%, 11.5%, 4.7% and 6.0%, respectively, of the total mass of PM_2.5.

Graphical abstract

Keywords

PM_2.5; Water-soluble ions; Organic carbon (OC); Elemental carbon (EC); Crustal matter

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