PM2.5 Chemical Compositions and Aerosol Optical Properties in Beijing during the Late FallReport as inadecuate

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Key Laboratory of Reservoir Aquatic Environment of CAS, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China


School of Chemistry and Environment, Beihang University, Beijing 100191, China


Key Lab of Aerosol Chemistry & Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xian 710075, China


School of Physics, Peking University, Beijing 100871, China


State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, School of Environment, Tsinghua University, Beijing 100084, China


Author to whom correspondence should be addressed.

Academic Editors: Ru-Jin Huang and Robert W. Talbot

Abstract Daily PM2.5 mass concentrations and chemical compositions together with the aerosol optical properties were measured from 8–28 November 2011 in Beijing. PM2.5 mass concentration varied from 15.6–237.5 μg∙m−3 and showed a mean value of 111.2 ± 73.4 μg∙m−3. Organic matter, NH4NO3 and NH42SO4 were the major constituents of PM2.5, accounting for 39.4%, 15.4%, and 14.9% of the total mass, respectively, while fine soil, chloride salt, and elemental carbon together accounted for 27.7%. Daily scattering and absorption coefficients σsc and σap were in the range of 31.1–667 Mm−1 and 8.24–158.0 Mm−1, with mean values of 270 ± 200 Mm−1 and 74.3 ± 43.4 Mm−1. Significant increases in σsc and σap were observed during the pollution accumulation episodes. The revised IMPROVE algorithm was applied to estimate the extinction coefficient bext. On average, organic matter was the largest contributor, accounting for 44.6% of bext, while NH42SO4, NH4NO3, elemental carbon, and fine soil accounted for 16.3% 18.0%, 18.6%, and 2.34% of bext, respectively. Nevertheless, the contributions of NH42SO4 and NH4NO3 were significantly higher during the heavy pollution periods than those on clean days. Typical pollution episodes were also explored, and it has been characterized that secondary formation of inorganic compounds is more important than carbonaceous pollution for visibility impairment in Beijing. View Full-Text

Keywords: PM2.5; visibility; aerosol optical properties; chemical composition PM2.5; visibility; aerosol optical properties; chemical composition

Author: Huanbo Wang 1, Xinghua Li 2, Guangming Shi 1, Junji Cao 3, Chengcai Li 4, Fumo Yang 1,* , Yongliang Ma 5 and Kebin He 5



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