Effect of chemical composition of PM2.5 on visibility in Guangzhou, China, 2007 spring--颗粒学报PARTICUOLOGY

Tao, J., Ho, K.-F., Chen, L., Zhu, L., Han, J., & Xu, Z. (2009). Effect of chemical composition of PM2.5 on visibility in Guangzhou, China, 2007 spring. Particuology, 7(1), 68–75. https://doi.org/10.1016/j.partic.2008.11.002

Effect of chemical composition of PM_2.5on visibility in Guangzhou, China, 2007 spring

Jun Tao ^{a b *}, Kin-Fai Ho ^{a b}, Laiguo Chen ^a, Lihua Zhu ^a, Jinglei Han ^a, Zhencheng Xu ^a

a South China Institute of Environmental Sciences, SEPA, Guangzhou 510655, China
b The Hong Kong Polytechnic University, Hong Kong, China

10.1016/j.partic.2008.11.002

Volume 7, Issue 1, 18 February 2009, Pages 68-75

Received 2 July 2008, Accepted 3 November 2008, Available online 13 January 2009.

E-mail: taojun@scies.com.cn

Highlights

Abstract

The object of this study was to investigate the correlation of visibility with chemical composition of PM_2.5 in Guangzhou. In April 2007, 28 PM_2.5 samples were collected daily at the monitoring station of the South China Institute of Environmental Sciences (SCIES), in urban Guangzhou. Water-soluble ionic species (Cl⁻, NO³⁻, SO₄²⁻, NH₄⁺, K⁺, Na⁺, Ca²⁺, and Mg²⁺) and carbonaceous contents (OC and EC) of the PM_2.5 samples were determined to characterize their impact on visibility impairment. The results showed that sulfate was the dominant species that affected both light scattering and visibility. The average percentage contributions of the visibility-degrading species to light scattering coefficient were 40% for sulfate, 16% for nitrate, 22% for organics, and 22% for elemental carbon. Because of its foremost effect on visibility, sulfate reduction in PM_2.5 would effectively improve the visibility of Guangzhou.

Graphical abstract

Keywords

Visibility; PM_2.5; Carbonaceous aerosols; Water-soluble ions

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