Record Display for the EPA National Library Catalog


Main Title Environmental Photoprocesses Involving Natural Organic Matter.
Author Zepp, R. G. ;
CORP Author Environmental Research Lab., Athens, GA.
Year Published 1987
Report Number EPA/600/D-87/194;
Stock Number PB87-199006
Additional Subjects Photochemical reactions ; Electromagnetic absorption ; Light(Visible radiation) ; Sunlight ; Energy transfer ; Free radicals ; Humic acids ; Reprints ; Humic substances ; Organic materials ; Soil chemistry
Library Call Number Additional Info Location Last
NTIS  PB87-199006 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 30p
Current research is reviewed on the photoreactions that occur when sunlight interacts with soil and aquatic organic matter. The primary focus is on photoprocesses involving humic substances. Investigations of the direct photoreactions of humic substances are discussed, with emphasis on the fading of the uv-visible and fluorescence spectra. The balance of the background paper deals with sunlight-induced reactions between humic substances and trace organic or metallic substrates. Recent studies have shown that these indirect photoreactions are mediated by electronically excited states or reactive intermediates derived therefrom that react with substrates by electronic energy transfer, by electron transfer, and/or by various free radical processes. Concepts and methods that are used to elucidate the nature and concentrations of these transient reactants are discussed, including approaches based on steady-state irradiations and techniques that employ laser flash photolysis.