Chemical Closure Study on Hygroscopic Properties of Urban Aerosol Particles in Sapporo, Japan

详细信息    查看全文

• 作者：Shankar Gopala Aggarwal ; Michihiro Mochida ; Yasuyuki Kitamori ; Kimitaka Kawamura
• 刊名：Environmental Science & Technology
• 出版年：2007
• 出版时间：October 15, 2007
• 年：2007
• 卷：41
• 期：20
• 页码：6920 - 6925
• 全文大小：189K
• 年卷期：v.41,no.20(October 15, 2007)
• ISSN：1520-5851

文摘

To assess the link between hygroscopicity of atmosphericparticles and the chemical composition, we performeda chemical closure study on the hygroscopicity of organic-inorganic mixed particles nebulized from water extractsof ambient aerosols collected in Sapporo, Japan duringsummer 2005. The hygroscopicity of 100 nm particles wasmeasured using a hygroscopicity tandem differentialmobility analyzer (HTDMA) at 5-95% relative humidity.The chemical analyses of the extracts showed that inorganicsalts accounted for 32-84% of the water-soluble fractionand that the remaining was water-soluble organicmatter (WSOM). The liquid water content (LWC) of particleswas primarily governed by the relative abundance ofinorganic salts in particles. The chemical closure with athermodynamic model did not indicate a significantperturbation of LWC by WSOM at 85% RH with theconsideration of the uncertainties estimated. However, apositive perturbation by WSOM was suggested at 50% RH.Individual oxygenated compounds identified using gaschromatography were not abundant enough to substantiallyincrease the LWC at 85% RH.