Photochemical formation of H/sub 2/O/sub 2/ in natural waters exposed to sunlight
Hydrogen peroxide is formed in most natural waters when they are exposed to sunlight. The rate at which H/sub 2/O/sub 2/ accumulates is related to the concentration of light-absorbing (>295 nm) organic substances in these waters. The photochemical accumulation rate of H/sub 2/O/sub 2/ in sunlight has been measured for several surface waters and ground waters and was found to be 2.7 /times/ 10/sup /minus/7/ to 48 /times/ 10/sup /minus/7/ mol L/sup /minus/1/ h/sup /minus/1/, in waters ranging from 0.53 to 18 mgL/sup -1/ dissolved organic carbon (DOC), respectively. These rates were determined in midday sunlight, 0.4 W m/sup /minus/2/ (295-385 nm), latitude 24.3/degrees/ N. Apparent quantum yields of H/sub 2/O/sub 2/ have been determined for natural waters at different wavelengths. These quantum yields decreased with increasing wavelength, from 10/sup /minus/3/ in the near-ultraviolet to 10/sup /minus/6/ in the visible spectral range. The quantum yields have been used in a photochemical model to calculate H/sub 2/O/sub 2/ accumulation rates of natural water samples. Model calculations agree with H/sub 2/O/sub 2/ accumulation rates obtained from exposing three different water samples to sunlight.
- Research Organization:
- Florida International Univ., Miami (USA)
- OSTI ID:
- 6211279
- Journal Information:
- Environ. Sci. Technol.; (United States), Vol. 22:10
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
HYDROGEN PEROXIDE
PHOTOCHEMICAL REACTIONS
GROUND WATER
MATHEMATICAL MODELS
ORGANIC MATTER
SOLAR RADIATION
SURFACE WATERS
WATER CHEMISTRY
CHEMICAL REACTIONS
CHEMISTRY
HYDROGEN COMPOUNDS
OXYGEN COMPOUNDS
PEROXIDES
RADIATIONS
STELLAR RADIATION
WATER
520200* - Environment
Aquatic- Chemicals Monitoring & Transport- (-1989)