Kinetics of the Sulfate Radical-Mediated Photo-oxidation of Humic Substances

PEDRO DAVID GARA; GABRIELA BOSIO; MONICA GONZALEZ; DANIEL MARTIRE

INTERNATIONAL JOURNAL OF CHEMICAL KINETICS

JOHN WILEY & SONS INC

Año: 2008 p. 19 - 24

0538-8066

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 flashphotolysis. 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