SO/sub 2/ flux to a falling raindrop in a polluted atmosphere

Journal Article · Mon Jan 01 04:00:00 EST 1979 · AIChE Symp. Ser.; (United States)

OSTI ID:7135909

Aneja, V P; Overton, Jr, J H; Durham, J L

An analysis of the transfer of sulfur dioxide to droplets is presented. A physicochemical model for the accumulation of sulfur species in raindrops is developed in which account is taken of the mass transfer of sulfur dioxide and ozone into ideal raindrops (of radii 0.1 and 0.001 cm) and of the oxidation of SO/sub 2/ in the presence of O/sub 3/ and catalysts. Ignoring charge separation, we use equations which describe the time development of chemical species within droplets. The model predicts the formation of sulfate due to ozone, catalytic oxidation, and ammonia. The expressions provide an analysis of rain composition as a function of fall distance for various atmospheric conditions of pH, SO/sub 2/, O/sub 3/, and catalyst concentration and fall velocities. After a fall distance 2,000 meters, the concentration of sulfate in the droplets is a function of droplet radius and background pollutant concentrations. The calculations indicate that the pH of the precipitation varies from 3.9 to 6.4 in polluted regions and is independent of the initial pH of the droplet. However, for the large droplet and initial pH of 10, the droplet remained basic.

• OSTI ID: 7135909
• Journal Information: AIChE Symp. Ser.; (United States), Journal Name: AIChE Symp. Ser.; (United States) Vol. 75:188; ISSN ACSSC
• Country of Publication: United States
• Language: English

Related Subjects

500200* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AIR POLLUTION
ATMOSPHERIC PRECIPITATIONS
CHALCOGENIDES
DROPLETS
ECOLOGICAL CONCENTRATION
ENVIRONMENTAL TRANSPORT
MASS TRANSFER
OXIDES
OXYGEN COMPOUNDS
OZONE
PARTICLE SIZE
PARTICLES
PH VALUE
POLLUTION
RAIN
SIZE
SULFATES
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES