Photolysis of Fe(III)-hydroxy complexes as a source of hydroxyl radicals in atmospheric waters

Conference · Thu Sep 01 04:00:00 EDT 1988 · Preprints of Papers Presented at National Meeting, Division of Water, Air and Waste Chemistry, American Chemical Society; (USA)

OSTI ID:7019800

Faust, B C ^[1]; Hoigne, J ^[2]

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1. Duke Univ., Durham, NC (USA)
2. EAWAG, Duebendorf (Switzerland)

The authors initiated an investigation to measure rates of Fe(OH){sup 2+} photolysis under conditions which closely approximate the chemical conditions of acidified clouds, rain, and fog. To this end experiments were performed, using sunlight or monochromatic light, with air-saturated solutions containing 10{sup {minus}5} M soluble, monomeric Fe(III), at pH = 3-4. A critical review of 40 years of literature provided quantum yields for this reaction, which together with their own measurements of quantum yields were used in a photochemical model to predict rates of Fe(OH){sup 2+} photolysis in sunlight. Their experimental and model results indicate that the sunlight photolysis rate of Fe(OH){sup 2+} is significantly faster than previous conservative estimates. Additional results are presented on model calculations of the sunlight photolysis of Fe(III) dimers, Fe{sub 2}(OH){sub 2}{sup 4+}, as a source of OH radicals, and on their experimental investigations of the photolysis of Fe(III)-oxalate complexes as a source of Fe(II). A general discussion is given on photochemical reactions of Fe(III) complexes as a direct aqueous phase source of OH radicals, and as a source of OH radicals, and on their experimental investigations of the photolysis of Fe(III)-oxalate complexes as a source of Fe(II). A general discussion is given on photochemical reactions of Fe(III) complexes as a direct aqueous phase source of OH radicals, and as an indirect aqueous phase source of oxy-radicals produced in the re-oxidation of Fe(II) to Fe(III).

• OSTI ID: 7019800
• Report Number(s): CONF-8909232--
• Conference Information: Journal Name: Preprints of Papers Presented at National Meeting, Division of Water, Air and Waste Chemistry, American Chemical Society; (USA) Journal Volume: 28:2
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540120* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
ACID RAIN
AQUEOUS SOLUTIONS
ATMOSPHERIC CHEMISTRY
ATMOSPHERIC PRECIPITATIONS
CATIONS
CHARGED PARTICLES
CHEMICAL REACTIONS
CHEMISTRY
CLOUDS
COMPLEXES
DECOMPOSITION
DISPERSIONS
FOG
HYDROGEN COMPOUNDS
HYDROXIDES
HYDROXYL RADICALS
IONS
IRON COMPLEXES
MATHEMATICAL MODELS
MEDIUM TEMPERATURE
MIXTURES
OXYGEN COMPOUNDS
PH VALUE
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
RADICALS
RAIN
SOLUTIONS
TRANSITION ELEMENT COMPLEXES