Kinetics of hydrogen peroxide--sulfur(IV) reaction in rainwater collected at a northeastern U. S. Site
The kinetics of the reaction of dissolved S(IV) with H/sub 2/O/sub 2/ was studied in freshly collected precipitation samples in order to examine whether there exist any important influences on this reaction from trace constituents present in natural atmospheric liquid water, that is, rainwater and snowmelt. The kinetic study was carried out on over 300 freshly collected precipitation samples obtained at Brookhaven National Laboratory, Long Island, New York, during the period from October 1983 to September 1985. The second-order rate constant k/sup (2)/, defined as -d(H/sub 2/O/sub 2/)/dt = k/sup (2)/(H/sub 2/O/sub 2/)(S(IV)), which was determined using the precipitation samples covering pH range 3.3--5.6, was found to be linearly dependent on H/sup +/ concentration, conforming to results previously obtained with purified water. The observed scatter in rate constant ( +- 30%, standard deviation) is comparable to interlaboratory scatter observed for purified water; the average rate constant is 15% less than values obtained in our laboratory using purified water at the same pH and ionic strength. The scatter and the systematic bias of the data were examined in terms of experimental techniques employed as well as chemical composition of the samples. Sample scatter is attributed in large part to uncertainty in measured pH. The difference in the average rate constant is small compared to the large scatter exhibited by the data. Causes of the negative bias were not clearly identified, but pH uncertainty, ionic strength, and the presence of formaldehyde were ruled out.
- Research Organization:
- Environmental Chemistry Division, Department of Applied Science, Brookhaven National Laboratory, Upton, New York
- OSTI ID:
- 7068002
- Journal Information:
- J. Geophys. Res.; (United States), Vol. 91:D12
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ATMOSPHERIC PRECIPITATIONS
WATER CHEMISTRY
BNL
CHEMICAL REACTION KINETICS
DISSOLVED GASES
HYDROGEN PEROXIDE
PH VALUE
SULFUR OXIDES
CHALCOGENIDES
CHEMISTRY
FLUIDS
GASES
HYDROGEN COMPOUNDS
KINETICS
NATIONAL ORGANIZATIONS
OXIDES
OXYGEN COMPOUNDS
PEROXIDES
REACTION KINETICS
SOLUTES
SULFUR COMPOUNDS
US AEC
US DOE
US ERDA
US ORGANIZATIONS
500200* - Environment
Atmospheric- Chemicals Monitoring & Transport- (-1989)