Low-intensity radiolysis study of free-radical reactions in cloudwater: H sub 2 O sub 2 production and destruction. [Gamma radiation]

Journal Article · Mon Apr 01 04:00:00 EST 1991 · Environmental Science and Technology; (United States)

DOI:https://doi.org/10.1021/es00016a027· OSTI ID:5156344

Weinstein-Lloyd, J; Schwartz, S E ^[1]

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1. Brookhaven National Lab., Upton, NY (United States)

Reactions in cloudwater can be important pathways for chemical transformation of atmospheric trace gases. One such reaction is the oxidation of dissolved sulfur dioxide by hydrogen peroxide. H{sub 2}O{sub 2} is formed by the disproportionation of hydroperoxyl and superoxide radicals, O{sub 2}({minus}I). The authors report measurements of the rate of H{sub 2}O{sub 2} production from O{sub 2}({minus}I) radicals generated by low-intensity cobalt-60 radiolysis of synthetic cloudwater solutions and actual precipitation samples. The authors results, employing O{sub 2}({minus}I) production rates comparable to those expected upon transfer of HO{sub 2} from interstitial cloud air to cloudwater, confirm model predictions that H{sub 2}O{sub 2} production if frequently the major fate of O{sub 2}({minus}I) radicals. However, there is evidence of significant reaction between S(IV) and O{sub 2}({minus}I), with a rate coefficient of (3 {plus minus} 2) {times} 10{sup 4} at pH 4.96. In addition, the presence of 1 {mu}M dissolved iron decreases the H{sub 2}O{sub 2} yield, principally because of destruction of H{sub 2}O{sub 2} by Fe(II).

• DOE Contract Number: AC02-76CH00016
• OSTI ID: 5156344
• Journal Information: Environmental Science and Technology; (United States), Journal Name: Environmental Science and Technology; (United States) Vol. 25:4; ISSN ESTHA; ISSN 0013-936X
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400600* -- Radiation Chemistry
54 ENVIRONMENTAL SCIENCES
540120 -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
ABSORPTION SPECTROSCOPY
AQUEOUS SOLUTIONS
ATMOSPHERIC CHEMISTRY
CHALCOGENIDES
CHEMICAL ANALYSIS
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMISTRY
CHROMATOGRAPHY
CLOUDS
DATA
DECOMPOSITION
DISPERSIONS
EARTH ATMOSPHERE
ELECTROMAGNETIC RADIATION
ELEMENTS
EXPERIMENTAL DATA
G VALUE
GAMMA RADIATION
HYDROGEN COMPOUNDS
HYDROGEN PEROXIDE
HYDROXYL RADICALS
INFORMATION
IONIZING RADIATIONS
KINETICS
LIQUID COLUMN CHROMATOGRAPHY
MATHEMATICAL MODELS
METALS
MIXTURES
NUMERICAL DATA
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PEROXIDES
QUANTITATIVE CHEMICAL ANALYSIS
RADIATION EFFECTS
RADIATIONS
RADICALS
RADIOLYSIS
REACTION KINETICS
REDUCTION
SEPARATION PROCESSES
SOLUTIONS
SPECTROSCOPY
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES
SUPEROXIDE RADICALS
SYNTHESIS
TRANSITION ELEMENTS
TROPOSPHERE
WATER