Abstract
Formation of haze is a phenomenon dependent on the relative atmospheric humidity and concentration of aerosol particles. The physical and chemical reactions on particle surfaces would lead to variations in particle sizes. This paper focuses on the physical behaviour of aerosol particles under the influence of atmospheric humidity, which produces liquid bridging forces and electrostatic interactions among particles. By water absorption experiment, a correlation between relative humidity (RH) and water content on particles was obtained. Through theoretical derivation, a relationship between the relative humidity and humidity ratio was established for calculating liquid bridging forces. The findings from experiments on atmospheric particles charging, showed most aerosols were negatively or positively charged and the average charges on these particles was more than one. An extended soft-sphere discrete element method (DEM) was used to simulate the evolution of aerosol particles, encapsulated in water vapour by considering liquid bridging forces, electrostatic interactions and Brownian forces. Results suggest that the agglomeration rate of particles would increase with a rise in the atmospheric humidity due to the increased liquid bridging forces that enhance the agglomeration velocity. The higher humidity would enhance the ionization on particle surfaces, which could affect electrostatic interactions. This paper provides an insight of a mechanism for formation of haze in atmosphere.
| Original language | English |
|---|---|
| Pages (from-to) | 141-149 |
| Number of pages | 9 |
| Journal | Atmospheric Environment |
| Volume | 197 |
| DOIs | |
| Publication status | Published - 2019 Jan 15 |
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Keywords
- Aerosol particles
- Agglomeration rate
- Atmospheric humidity
- Electrostatic interactions
- Haze formation
- Liquid bridging forces
- Particle charging
ASJC Scopus subject areas
- Environmental Science(all)
- Atmospheric Science
Cite this
Atmospheric humidity and particle charging state on agglomeration of aerosol particles. / He, Yuanping; Gu, Zhaolin; Lu, Weizhen; Zhang, Liyuan; Okuda, Tomoaki; Fujioka, Kentaro; Luo, Hui; Yu, Chuck Wah.
In: Atmospheric Environment, Vol. 197, 15.01.2019, p. 141-149.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Atmospheric humidity and particle charging state on agglomeration of aerosol particles
AU - He, Yuanping
AU - Gu, Zhaolin
AU - Lu, Weizhen
AU - Zhang, Liyuan
AU - Okuda, Tomoaki
AU - Fujioka, Kentaro
AU - Luo, Hui
AU - Yu, Chuck Wah
PY - 2019/1/15
Y1 - 2019/1/15
N2 - Formation of haze is a phenomenon dependent on the relative atmospheric humidity and concentration of aerosol particles. The physical and chemical reactions on particle surfaces would lead to variations in particle sizes. This paper focuses on the physical behaviour of aerosol particles under the influence of atmospheric humidity, which produces liquid bridging forces and electrostatic interactions among particles. By water absorption experiment, a correlation between relative humidity (RH) and water content on particles was obtained. Through theoretical derivation, a relationship between the relative humidity and humidity ratio was established for calculating liquid bridging forces. The findings from experiments on atmospheric particles charging, showed most aerosols were negatively or positively charged and the average charges on these particles was more than one. An extended soft-sphere discrete element method (DEM) was used to simulate the evolution of aerosol particles, encapsulated in water vapour by considering liquid bridging forces, electrostatic interactions and Brownian forces. Results suggest that the agglomeration rate of particles would increase with a rise in the atmospheric humidity due to the increased liquid bridging forces that enhance the agglomeration velocity. The higher humidity would enhance the ionization on particle surfaces, which could affect electrostatic interactions. This paper provides an insight of a mechanism for formation of haze in atmosphere.
AB - Formation of haze is a phenomenon dependent on the relative atmospheric humidity and concentration of aerosol particles. The physical and chemical reactions on particle surfaces would lead to variations in particle sizes. This paper focuses on the physical behaviour of aerosol particles under the influence of atmospheric humidity, which produces liquid bridging forces and electrostatic interactions among particles. By water absorption experiment, a correlation between relative humidity (RH) and water content on particles was obtained. Through theoretical derivation, a relationship between the relative humidity and humidity ratio was established for calculating liquid bridging forces. The findings from experiments on atmospheric particles charging, showed most aerosols were negatively or positively charged and the average charges on these particles was more than one. An extended soft-sphere discrete element method (DEM) was used to simulate the evolution of aerosol particles, encapsulated in water vapour by considering liquid bridging forces, electrostatic interactions and Brownian forces. Results suggest that the agglomeration rate of particles would increase with a rise in the atmospheric humidity due to the increased liquid bridging forces that enhance the agglomeration velocity. The higher humidity would enhance the ionization on particle surfaces, which could affect electrostatic interactions. This paper provides an insight of a mechanism for formation of haze in atmosphere.
KW - Aerosol particles
KW - Agglomeration rate
KW - Atmospheric humidity
KW - Electrostatic interactions
KW - Haze formation
KW - Liquid bridging forces
KW - Particle charging
UR - http://www.scopus.com/inward/record.url?scp=85055435353&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85055435353&partnerID=8YFLogxK
U2 - 10.1016/j.atmosenv.2018.10.035
DO - 10.1016/j.atmosenv.2018.10.035
M3 - Article
AN - SCOPUS:85055435353
VL - 197
SP - 141
EP - 149
JO - Atmospheric Environment
JF - Atmospheric Environment
SN - 1352-2310
ER -