Modeling the photolysis of ammonium dinitramide in natural waters

Photolytic rate constants for the novel energetic compound ammonium dinitra mide (ADN) were determined in order to understand the fate of ADN in natura l bodies of water. Quantum yields were measured between 290 and 400 nm usin g a lamp system, and these values were combined with absorption of light in a water column to model photolysis rates as a function of depth. The valid ity of this model was tested in field trials in Onondaga Lake, Syracuse, Ne w York, USA. For a summertime irradiation, half-lives ranged from similar t o6 min at the surface to similar to 15 years at a depth of 2 m. The predict ed and observed degradation rates of ADN were sufficiently similar to justi fy use of this simple model. It was also found that the degradation of ADN is not enhanced to any measurable degree by sensitized photoreactions in hu mic solutions. Thus, the photodegradation of ADN can be predicted throughou t the water column of a body of water.