Hydroscopic and hydrate water in aerosols and their effect on fine-particle mass and on atmospheric extinction

Conference · Fri Jan 01 04:00:00 EST 1982

OSTI ID:6527655

Rote, D M

Regression analyses of a large body of fine-particle mass (FP mass) and fine-particle sulfate ion (FPSO/sub 4//sup =/) concentration data have shown that for a regression equation of the form, chi/sub FPmass/ = a + b.Chi/sub FPSO/sub 4//sup =/, the slope (b) ranges from 1.8 to 2.53 depending on the time of year. Values of r/sup 2/ obtained from these regression fits ranged from 0.79 to 0.84. The regression line slope is of special interest because it measures the ratio of that portion of the fine particle mass that is correlated with the sulfate ions to the mass of the sulfate ions. A simple model of a fine particle atmospheric aerosol containing a mixture of sulfuric acid, ammonium bisulfate, and ammonium sulfate with a ratio of ammonium ions to SO/sub 4//sup =/ of about 1.25 would lead to a ratio of total sulfate mass to SO/sub 4//sup =/ mass of about 1.24. Comparing this ratio with the ratio of that portion of the FP mass that is correlated with the sulfate ions to the mass of the SO/sub 4//sup =/ shows a considerable discrepancy. The question therefore arises as to how to account for the numerical range of 1.8 to 2.53 of the mass ratio obtained from the regression analyses. By invoking some plausible assumptions regarding mixtures including both hygroscopic water and hydrated states of sulfate compounds, a model is hypothesized that is able to account for mass ratio of about 1.64 +- 0.33. An additional hypothesis is invoked to explain the occurrence of higher mass ratios. The results of this aerosol model were combined with a long-range transport sulfate model and a visual range algorithm to predict visual ranges over eastern United States for various relative humidities. Numerical results are presented.

• Research Organization: Argonne National Lab., IL (USA)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 6527655
• Report Number(s): CONF-8204111-1; ON: DE83007672
• Country of Publication: United States
• Language: English

Related Subjects

500200* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AEROSOL MONITORING
AEROSOLS
AIR POLLUTION
AMMONIUM COMPOUNDS
AMMONIUM SULFATES
ANIONS
CATIONS
CHARGED PARTICLES
CHEMICAL COMPOSITION
COLLOIDS
COMPARATIVE EVALUATIONS
DISPERSIONS
HYDRATES
HYDROGEN COMPOUNDS
HYGROSCOPICITY
INORGANIC ACIDS
IONS
MASS
MATHEMATICAL MODELS
MATHEMATICS
MONITORING
OXYGEN COMPOUNDS
PARTICLE SIZE
PARTICLES
PARTICULATES
POLLUTION
QUANTITY RATIO
REGRESSION ANALYSIS
SIZE
SOLS
STATISTICS
SULFATES
SULFUR COMPOUNDS
SULFURIC ACID
VISIBILITY
WATER