Accession Number:

ADA383559

Title:

Photochemistry of Hazardous Chemicals in Natural Water

Descriptive Note:

Rept. for 1 Sep 1996-31 Aug 1999

Corporate Author:

STATE UNIV OF NEW YORK AT ALBANY

Personal Author(s):

Report Date:

2000-07-31

Pagination or Media Count:

137.0

Abstract:

The aquatic photo chemistry of two high-energy compounds was investigated as a part of a larger study of their environmental fate. Ammonium dinitramide ADN absorbs light 4OOnm and degrades rapidly upon exposure to sunlight. Half-lives for the photolysis of ADN at the surface of a body of water were calculated as six minutes for a location in Syracuse, NY. However, much of the light that degrades ADN directly is absorbed in the top layer of water the half-life at a depth of 2m was calculated as 15 years. A model of the absorption of light passing through the water column in combination with quantum yields was used in order to compare predicted and observed rates in Onondaga Lake, with good agreement. Dark solutions of ADN were stable indefinitely and indirect photolysis did not provide a significant decay mechanism. Although quadricyclane did not photolyze in distilled water, it degraded if natural dissolved organic matter DOM was also present. This phenomenon was ascribed to the reaction of quadricyclane with hydroperoxy HOe and its conjugate base, superoxide 02 degrees. The kinetics of this reaction were tested through the use of an alternative Hoee2- generator, xanthine-xanthine oxidase and a probe, ferricytochrome C. Using quadricyclan9 as a probe, the pH dependence of the production rate of Hoee2 was determined for a commercial humic solution. Results indicated that the predominant mechanism of formation of Hoee2 was electron transfer from an excited DOM moiety to oxygen and not the reaction of oxygen with hydrated electrons, photejected by excited DOM.

Subject Categories:

  • Inorganic Chemistry
  • Organic Chemistry
  • Solid Wastes and Pollution and Control

Distribution Statement:

APPROVED FOR PUBLIC RELEASE