DOI: 10.1016/j.atmosenv.2015.09.056
Scopus记录号: 2-s2.0-84944039580
论文题名: Phase considerations in the gas/particle partitioning of organic amines in the atmosphere
作者: Pankow J ; F
刊名: Atmospheric Environment
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2015
卷: 122 起始页码: 448
结束页码: 453
语种: 英语
英文关键词: Amines
; Free-base
; OPM
; Organic particulate matter
; Secondary organic aerosol
; SOA
Scopus关键词: Aerosols
; Amines
; Carbon
; Gases
; Ions
; Liquids
; Protonation
; Salts
; Solvation
; Water absorption
; Free base
; OPM
; Organic particulate matters
; Secondary organic aerosols
; SOA
; Organic chemicals
; amine
; organic compound
; absorption
; aerosol formation
; ammonium compound
; anthropogenic source
; atmospheric particle
; concentration (composition)
; conceptual framework
; gas phase reaction
; organic pollutant
; particulate inorganic matter
; partition coefficient
; solid solution
; Article
; atmosphere
; conceptual framework
; exhaust gas
; gas analysis
; particle size
; particulate matter
; phase transition
; priority journal
; proton transport
; secondary organic aerosol
; solid
; water transport
; Nicotiana tabacum
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: Amines in the atmosphere are of interest because of their likely role in new particle formation, and because of anthropogenic emissions of amines at post-combustion carbon capture (PCCC) facilities. A conceptual framework for considering the partitioning of a monobasic amine (Am = unprotonated, "free-base form") from the gas phase to atmospheric particulate matter (PM) is presented for cases when the PM may be composed of multiple liquid phases. Three types of liquid phases are considered as being individually or simultaneously possible for absorptive uptake of atmospheric amines: w) a mostly water phase; α) a mostly (by mass) organic phase that has at least some polarity (e.g., predominantly secondary organic aerosol (SOA), may contain significant water on a mole fraction basis); and β) a mostly organic phase that is less polar than an α phase (e.g., predominantly primary organic aerosol (POA), containing little water). That one or more salts may contain the aminium ion AmH+ (formed by protonation of Am) is subject to the fact that the trace levels of individual amines in the atmosphere make formation of a pure solid such as AmHHSO4(s) exceedingly unlikely: when solid salts of AmH+ are indeed present, by far the most likely form is as a solid solution, e.g., (NH4+)1-y(AmH+)yHSO4(s)- where y << 1. Neglecting dissolution in solid salts, and considering only partitioning to liquid phases, the overall gas/particle partitioning constant is Kp,tot(m3μg-1) = cp,tot/cg = ∑θfθKp,fbθ/αfbθ. The quantity cp,tot (μg μg-1) is the total Am concentration (Am + AmH+) in the PM as summed over all phases using the index θ (= w, α, β); cg is the gas-phase concentration of Am; f θ is the mass fraction of the total PM that is the θ phase; Kp,fbθ is the gas/particle partitioning constant for the free-base (Am) form to the θ phase; and 0 < αfbθ < 1 is the fraction of the amine in the θ phase that is in the free-base form. To date, most treatments of the partitioning of amines to PM have only considered contributions to Kp,tot from absorption into a mostly water phase, according to the term fwKp,fbw/αfbw. However, unless the PM contains little or no organic-phase material, the α and/or β terms are likely to also be relevant. The Am form of a low MW amine will in general have reasonable affinities for both α and β type phases, so in general Kp,fbw, Kp,fbα, and Kp,fbβ will all be roughly similar in magnitude. And, with significant water uptake into an α phase certain to occur at moderate to high RH values, solvation of ions will often be possible in an α phase. This will assist protonation of Am to AmH+ (as is known to occur for nicotine in tobacco smoke PM). The overall result is that to a first approximation, αfbw and αfbα can be similar in magnitude, making Kp,fbα/αfbα likely to be generally comparable to Kp,fbw/αfbw. In a β phase, ion solvation will not be as good, so that for acidic aerosol αfbβ will generally be closer to one than the other two αfb values, making Kp,fbβ/αfbβ smaller than both Kp,fbw/αfbw and Kp,fbα/αfbα Overall, modeling of amine behavior in the atmosphere should include consideration of partitioning into organic PM. Unfortunately, this will be more difficult than water-phase only modeling because prediction of αfb values in multiphase PM will be greatly complicated by the needs to: 1) have estimated values of acidity constants in mostly organic phases of variable composition; and 2) allow distribution of chemicals over multiple liquid phases. © 2015 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/81391
Appears in Collections: 气候变化事实与影响
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作者单位: Department of Chemistry, Portland State University, Portland, OR, United States; Department of Civil and Environmental Engineering, Portland State University, Portland, OR, United States
Recommended Citation:
Pankow J,F. Phase considerations in the gas/particle partitioning of organic amines in the atmosphere[J]. Atmospheric Environment,2015-01-01,122