SO/sub 2/-oxidation by hydrogen peroxide in suspended droplets

Conference · Tue Apr 01 04:00:00 EST 1986 · Am. Chem. Soc., Div. Pet. Chem., Prepr.; (United States)

OSTI ID:5432373

Jaeschke, W A; Herrmann, G J

Recent measurements of gas- and liquid-phase concentrations of hydrogen peroxide in the troposphere substantiate the notion that H/sub 2/O/sub 2/ is the major oxidant leading to the generation of sulfuric acid in atmospheric multiphase systems like fogs and clouds. The oxidation of S(IV)/sub aq/ requires a phase transfer of gaseous SO/sub 2/ into the suspended droplets. This transfer represents a chain of consecutive processes including transport of (SO/sub 2/)/sub g/ to the droplets, phase-transfer through the gas-liquid interface, transport of dissolved S(IV) in the liquid phase and subsequent oxidation of S(IV)/sub aq/ to S(IV)/sub aq/ by dissolved H/sub 2/O/sub 2/. Because of the consecutive nature of this multiphase oxidation process the slowest step of the chain determines the overall rate. Commonly the overall rates of such processes occurring in atmospheric fog and clouds are calculated by linear extrapolations from kinetic data gained in bulk-solution experiments. It is at least doubtful whether the assumed linear relations are exist in atmospheric systems, especially with respect to the liquid water content (LWC) of fogs and clouds because this parameter is the result of the integral over a spectrum of droplets in the range of 1..mu..m < r < 20..mu..m. In this droplet size range, either gas-phase or aqueous-phase mass transport of S(IV) may become rate-determining because the oxidation reaction of S(IV) by H/sub 2/O/sub 2/ is assumed to be very fast. In addition at SO/sub 2/-mass-accommodation-coefficients below 10/sup -2/ the interfacial transport of S(IV)-species may also govern the rate of the multiphase oxidation reaction.

• Research Organization: Center for Environmental Research, J.W. Goethe-Univ., P.O. Box 11 19 32, D-6000 Frankfurt am Main
• OSTI ID: 5432373
• Report Number(s): CONF-860425-
• Conference Information: Journal Name: Am. Chem. Soc., Div. Pet. Chem., Prepr.; (United States) Journal Volume: 31:2
• Country of Publication: United States
• Language: English

Related Subjects

500200* -- Environment
Atmospheric-- Chemicals Monitoring &amp; Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
ACID RAIN
ATMOSPHERIC CHEMISTRY
ATMOSPHERIC PRECIPITATIONS
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMISTRY
CLOUDS
COMPLEXES
DROPLETS
EARTH ATMOSPHERE
ECOLOGICAL CONCENTRATION
ENVIRONMENTAL TRANSPORT
FOG
HYDROGEN COMPOUNDS
HYDROGEN PEROXIDE
MASS TRANSFER
OXIDATION
OXIDES
OXIDIZERS
OXYGEN COMPOUNDS
PARTICLES
PEROXIDES
RAIN
SULFUR COMPLEXES
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES
TROPOSPHERE