Biodegradation of nitramines in water

n this study biodegradation of nitramines were investigated at low concentrations in a biodegradation simulation test. The experiments were conducted with natural lake and river water as bacterial inocula, and over periods of 56 days (2 months). Biotransformation was determined by liquid chromatography – triple quadrupole mass spectrometry (LC-MS-MS-QQQ), and degradation rates determined by non-linear regression analyses. Biodegradation was mainly associated with nitramines containing OH-groups. The degradation decreased in cold water, comparing water temperatures from 20 to 5°C, and Q10-values were suggested for of the chemicals. Biodegradation experiments with AMP-NO₂ was performed in water from the Mongstad area and compared with local water (Trondheim), showing that degradation was comparable between the water sources. A biodegradation database was used to suggest degradation pathways, showing that hydroxyl and methyl groups were reaction sites rather than nitramine/amine sites.