Premium
Kinetics of the sulfate radical‐mediated photo‐oxidation of humic substances
Author(s) -
Gara Pedro M. David,
Bosio Gabriela N.,
Gonzalez Mónica C.,
Mártire Daniel O.
Publication year - 2008
Publication title -
international journal of chemical kinetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.341
H-Index - 68
eISSN - 1097-4601
pISSN - 0538-8066
DOI - 10.1002/kin.20287
Subject(s) - chemistry , radical , flash photolysis , kinetics , sulfate , humic acid , aqueous solution , enthalpy , photochemistry , standard enthalpy of formation , organic chemistry , reaction rate constant , thermodynamics , fertilizer , physics , quantum mechanics
The kinetics of the aqueous phase reaction of sulfate radicals with commercial humic acids and with organic matter extracted from vermicompost (VC) was studied by flash‐photolysis. The results can be interpreted by a mechanism that in a first step considers the reversible binding of the sulfate radicals by the humic substances. Both the bound and free sulfate radicals decay to oxidized products. From experiments performed with Aldrich humic acids in the temperature range from 283 to 303 K, the enthalpy change associated with the binding process was estimated to be −(36 ± 11) kJ mol −1 . © 2007 Wiley Periodicals, Inc. Int J Chem Kinet 40: 19–24, 2008