Field observations and quantifications of atmospheric formaldehyde partitioning in gaseous and particulate phases.
Sci Total Environ
; 808: 152122, 2022 Feb 20.
Article
em En
| MEDLINE
| ID: mdl-34871687
ABSTRACT
Formaldehyde (HCHO) can possibly be taken by atmospheric particles due to its moderate solubility. Although previous model studies have proposed that uptake by particles was a large sink for HCHO, direct observation of HCHO partitioning and estimation of HCHO uptake coefficient (γ) for tropospheric conditions are still limited. In this work, online measurements of gaseous HCHO (HCHOg) and particulate HCHO (HCHOp) were carried out simultaneously at an urban site in Beijing in winter and spring. The results indicated that the average concentrations of HCHOp ranged from 0.15 to 0.4 µg m-3, accounting for 1.2% to 10% of the total HCHO (i.e., HCHOg + HCHOp). The median values of estimated γ based on the measured data were in the range of about 1.09 ∗ 10-5-2.42 ∗ 10-4, with lower values during PM2.5 pollution episodes. Besides, the pH and liquid water content of aerosols that are mainly determined by ambient relative humidity (RH) and inorganic salt composition were identified as the main influencing factors of γ. We propose that the HCHO uptake process was mainly driven by hydrone and hydrogen ions in particles.
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Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Poluentes Atmosféricos
/
Gases
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Sci Total Environ
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
China