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Hygroscopic properties of organic and inorganic aerosols[Dissertation 17260]

Abstract

The atmosphere contains gases and particulate matter (aerosol). Organic material is present both in the gas phase and in the aerosol phase. Biogenic sources such as vegetation and anthropogenic sources such as biomass burning, fossil fuel use and various industries contribute to their emissions. The study of organic compounds in aerosol particles is of importance because they affect the water uptake (hygroscopicity) of inorganic aerosol, and hence the radiation budget of the Earth through the direct and indirect aerosol effects. The hygroscopicity of mixed organic/inorganic aerosol particles produced in the laboratory was characterized. This work reports on the following substances, and mixtures of them with ammonium sulfate (AS): adipic acid (AA), citric acid (CA), glutaric acid (GA) and humic acid sodium salt (NaHA). The AA and NaHA mixtures with AS were found to require up to tens of seconds for equilibrium water content to be reached. Therefore, measurements carried out on timescales shorter than a few seconds underestimate the hygroscopic growth factor (GF) with up to 10%, for samples containing a solid phase. Conversely, the GA and CA mixtures with AS were found to take up water readily and were well described by the Zdanovskii-Stokes-Robinson (ZSR) mixing rule. The distinct  More>>
Publication Date:
Jul 01, 2007
Product Type:
Thesis/Dissertation
Report Number:
ETDE-CH-10012
Resource Relation:
Other Information: TH: Diss. (Doctor of Sciences)
Subject:
54 ENVIRONMENTAL SCIENCES; AEROSOLS; DUSTS; PARTICULATES; HYGROSCOPICITY; AIR POLLUTION; GREENHOUSE EFFECT; BENCH-SCALE EXPERIMENTS; COMPARATIVE EVALUATIONS; INORGANIC COMPOUNDS; AMMONIUM SULFATES; ORGANIC COMPOUNDS; ADIPIC ACID; CITRIC ACID; HUMIC ACIDS; GLUTARIC ACID; COMBUSTION; SMOKES; REVIEWS; DYNAMICS; GROWTH FACTORS; NITRIC ACID; DESERTS; ALPS; CONDENSATION NUCLEI; EARTH ATMOSPHERE
Sponsoring Organizations:
Paul Scherrer Institut (PSI), Laboratory of Atmospheric Chemistry (LAC), Villigen (Switzerland)
OSTI ID:
21318454
Research Organizations:
Paul Scherrer Institut (PSI), Villigen (Switzerland)
Country of Origin:
Switzerland
Language:
English
Other Identifying Numbers:
TRN: CH08E1175
Availability:
Commercial reproduction prohibited; OSTI as DE21318454
Submitting Site:
CH
Size:
124 pages
Announcement Date:
Jul 02, 2010

Citation Formats

Sjoegren, N O Staffan. Hygroscopic properties of organic and inorganic aerosols[Dissertation 17260]. Switzerland: N. p., 2007. Web.
Sjoegren, N O Staffan. Hygroscopic properties of organic and inorganic aerosols[Dissertation 17260]. Switzerland.
Sjoegren, N O Staffan. 2007. "Hygroscopic properties of organic and inorganic aerosols[Dissertation 17260]." Switzerland.
@misc{etde_21318454,
title = {Hygroscopic properties of organic and inorganic aerosols[Dissertation 17260]}
author = {Sjoegren, N O Staffan}
abstractNote = {The atmosphere contains gases and particulate matter (aerosol). Organic material is present both in the gas phase and in the aerosol phase. Biogenic sources such as vegetation and anthropogenic sources such as biomass burning, fossil fuel use and various industries contribute to their emissions. The study of organic compounds in aerosol particles is of importance because they affect the water uptake (hygroscopicity) of inorganic aerosol, and hence the radiation budget of the Earth through the direct and indirect aerosol effects. The hygroscopicity of mixed organic/inorganic aerosol particles produced in the laboratory was characterized. This work reports on the following substances, and mixtures of them with ammonium sulfate (AS): adipic acid (AA), citric acid (CA), glutaric acid (GA) and humic acid sodium salt (NaHA). The AA and NaHA mixtures with AS were found to require up to tens of seconds for equilibrium water content to be reached. Therefore, measurements carried out on timescales shorter than a few seconds underestimate the hygroscopic growth factor (GF) with up to 10%, for samples containing a solid phase. Conversely, the GA and CA mixtures with AS were found to take up water readily and were well described by the Zdanovskii-Stokes-Robinson (ZSR) mixing rule. The distinct deliquescence and efflorescence points of AS could be seen to gradually disappear as the CA content was increased. Furthermore mineral dust (standard Arizona test dust) was investigated, as well as the influence of nitric acid (HNO{sub 3}) uptake thereon. Mineral dust is hydrophobic, but after processing with HNO{sub 3} turns slightly hygroscopic. Large amounts of dust are injected to the atmosphere (largely from the Sahara and the Gobi deserts, but also from human land-use). Mineral dust is important as ice nuclei, and due to its larger sizes it can also contribute as cloud condensation nuclei. Mineral dust also offers surface for heterogeneous chemistry, and can play an important role in the HNO{sub 3} cycle in the atmosphere through scavenging of HNO{sub 3} on the mineral dust surface. Hygroscopicity measurements in the atmosphere at the high alpine site Jungfraujoch (JFJ) were performed. At the JFJ the aerosol consists most of the time of organic and inorganic salts, mostly as an internal homogeneous mixture. However, about 5% of the time (yearly average) air trajectories passing the Sahara are encountered which carry mineral dust from there. For these occasions a fraction of particles with lower hygroscopicity was observed. No distinct phase transitions were observed in the range of relative humidity (RH) studied (10-90% RH). It was shown that the hygroscopic growth of the aerosol as a function of RH can be well described with a single-parameter empirical model, and that the GF could be estimated with the ZSR relation by using the measured aerosol composition at the JFJ. (author)}
place = {Switzerland}
year = {2007}
month = {Jul}
}