Chemical Characteristics of PM2.5 and PM10 in Haze-Fog Episodes in Beijing

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• 作者：Yele Sun ; Guoshun Zhuang ; Aohan Tang ; Ying Wang ; and Zhisheng An
• 刊名：Environmental Science & Technology
• 出版年：2006
• 出版时间：May 15, 2006
• 年：2006
• 卷：40
• 期：10
• 页码：3148 - 3155
• 全文大小：331K
• 年卷期：v.40,no.10(May 15, 2006)
• ISSN：1520-5851

文摘

Aerosol samples of PM_2.5 and PM₁₀ in a period of intensivehaze-fog (HF) events were collected to investigate thechemical characteristics of air pollution in Beijing. The airquality in HF episodes was much worse than that innonhaze-fog (NHF) days. The concentrations of elementsand water-soluble (WS) ions (K⁺, SO₄^2-, and NO₃^-) inHF episodes were more than 10 times higher than thosein NHF days. Most of the chemical species in PM_2.5 and thesecondary species (NH₄⁺, SO₄^2-, and NO₃^-) in PM₁₀showed significant difference between HF from westerlydirection (HFW) and southerly direction (HFS). Theconcentrations of secondary species in HFS were muchhigher than those in HFW, and other chemical species in HFSwere lower than those in HFW. The sources of PM_2.5were more from areas on the regional scale due to itstendency for long-range transport, while PM₁₀ was morelimited to the local sources. Aerosol particles were moreacidic in HFS and more alkaline in HFW. The secondary specieswere the major chemical components of the aerosol inHF episodes, and their concentrations increased in the orderof NHF < HFW < HFS. High concentrations of thesecondary aerosol in HF episodes were likely due to thehigher sulfur and nitrogen oxidation rate in aqueous-phasereactions. The serious air pollution in HF episodes wasstrongly correlated with the meteorological conditions andthe emissions of pollutants from anthropogenic sources.