Laboratory and modelling study of the hygroscopic properties of two model humic acid aerosol particles
Autor: | R.A. Cox, Francis D. Pope, Ben J. Dennis-Smither, L. Harper, Paul T. Griffiths, Simon L. Clegg |
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Rok vydání: | 2010 |
Předmět: |
Fluid Flow and Transfer Processes
chemistry.chemical_classification Atmospheric Science Environmental Engineering Water activity Chemistry Mechanical Engineering Sodium Inorganic chemistry Mineralogy chemistry.chemical_element complex mixtures Pollution Aerosol Particle Leonardite Humic acid Relative humidity UNIFAC |
Zdroj: | Journal of Aerosol Science. 41:457-467 |
ISSN: | 0021-8502 |
DOI: | 10.1016/j.jaerosci.2010.02.012 |
Popis: | The hygroscopic properties of aerosol particles, composed of two different commercially available humic acids, have been investigated in the temperature range 293–295 K as a function of relative humidity using an electrodynamic balance. The measured mass growth factors of Sigma-Aldrich humic acid sodium salt (NaHA) and leonardite humic acid (LHA) at 90% relative humidity are 1.87±0.02 and 1.20±0.05, respectively. There is a general agreement between the results described in this study with previous TDMA results, which are undertaken with smaller particle ensembles and shorter aerosol–water equilibration times. The measured mass growth factors of Sigma-Aldrich humic acid sodium salt (NaHA) and leonardite humic acid (LHA) at 90% relative humidity are 1.87±0.05 and 1.20±0.05, respectively. The UNIFAC model was used to calculate the relationship between water activity and the concentrations of a modelled LHA molecule, and thus the hygroscopicity. The LHA molecule was modelled by both the Steelink monomer and the Northeastern–Temple–Birmingham humic acid monomer structural models. |
Databáze: | OpenAIRE |
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