DOI: 10.1016/j.atmosenv.2014.09.049
Scopus记录号: 2-s2.0-84907919388
论文题名: Effect of nitrate and sulfate relative abundance in PM2.5 on liquid water content explored through half-hourly observations of inorganic soluble aerosols at a polluted receptor site
作者: Xue J ; , Griffith S ; M ; , Yu X ; , Lau A ; K ; H ; , Yu J ; Z
刊名: Atmospheric Environment
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2014
卷: 99 起始页码: 24
结束页码: 31
语种: 英语
英文关键词: Aerosol chemical composition
; Aerosol chemistry
; Chinese aerosols
; Ionic aerosol constituents
; Liquid water content
Scopus关键词: Aerosol chemical composition
; Aerosol chemistry
; Ionic aerosol constituents
; Liquid water content
; Receptor sites
; Relative abundance
; nitrate
; sulfate
; aerosol
; ammonium
; chemical composition
; concentration (composition)
; emission
; heterogeneity
; inhibition
; nitrate
; observational method
; particulate matter
; sulfate
; thermodynamics
; water content
; aerosol
; air pollutant
; Article
; chemical composition
; Chinese
; crystallization
; Hong Kong
; reduction
; thermodynamics
; water content
Scopus学科分类: Environmental Science: Water Science and Technology
; Earth and Planetary Sciences: Earth-Surface Processes
; Environmental Science: Environmental Chemistry
英文摘要: Liquid water content (LWC) is the amount of liquid water on aerosols. It contributes to visibility degradation, provides a surface for gas condensation, and acts as a medium for heterogeneous gas/particle reactions. In this study, 520 half-hourly measurements of ionic chemical composition in PM2.5 at a receptor site in Hong Kong are used to investigate the dependence of LWC on ionic chemical composition, particularly on the relative abundance of sulfate and nitrate. LWC was estimated using a thermodynamic model (AIM-III). Within this data set of PM2.5 ionic compositions, LWC was highly correlated with the multivariate combination of sulfate and nitrate concentrations and RH (R2 = 0.90). The empirical linear regression result indicates that LWC is more sensitive to nitrate mass than sulfate. During a nitrate episode, the highest LWC (80.6±17.9μgm-3) was observed and the level was 70% higher than that during a sulfate episode despite a similar ionic PM2.5 mass concentration. A series of sensitivity tests were conducted to study LWC change as a function of the relative nitrate and sulfate abundance, the trend of which is expected to shift to more nitrate in China as a result of SO2 reduction and increase in NOx emission. Starting from a base case that uses the average of measured PM2.5 ionic chemical composition (63% SO4 2-, 11% NO3 -, 19% NH4 +, and 7% other ions) and an ionic equivalence ratio, [NH4 +]/(2[SO4 2-]+[NO3 -]), set constant to 0.72, the results show LWC would increase by 204% at RH=40% when 50% of the SO4 2- is replaced by NO3 - mass concentration. This is largely due to inhibition of (NH4)3H(SO4)2 crystallization while PM2.5 ionic species persist in the aqueous phase. At RH=90%, LWC would increase by 12% when 50% of the SO4 2- is replaced by NO3 - mass concentration. The results of this study highlight the important implications to aerosol chemistry and visibility degradation associated with LWC as a result of a shift in PM2.5 ionic chemical composition to more nitrate in atmospheric environments as is expected in many Chinese cities. © 2014 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/80499
Appears in Collections: 气候变化事实与影响
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作者单位: Division of Environment, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong; Department of Chemistry, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
Recommended Citation:
Xue J,, Griffith S,M,et al. Effect of nitrate and sulfate relative abundance in PM2.5 on liquid water content explored through half-hourly observations of inorganic soluble aerosols at a polluted receptor site[J]. Atmospheric Environment,2014-01-01,99