title: Adsorption and attenuation behavior of 3-nitro-1,2,4-triazol-5-one (NTO) in eleven soils.
abstract: NTO (3-nitro-1,2,4-triazol-5-one) is one of the new explosive compounds used in insensitive munitions (IM) developed to replace traditional explosives, TNT and RDX. Data on NTO fate and transport is needed to determine its environmental behavior and potential for groundwater contamination. We conducted a series of kinetic and equilibrium batch experiments to characterize the fate of NTO in soils and the effect of soil geochemical properties on NTO-soil interactions. A set of experiments was also conducted using sterilized soils to evaluate the contribution of biodegradation to NTO attenuation. Measured pH values for NTO solutions decreased from 5.98 ± 0.13 to 3.50 ± 0.06 with increase in NTO concentration from 0.78 to 100 mg L(-1). Conversely, the pH of soil suspensions was not significantly affected by NTO in this concentration range. NTO experienced minimal adsorption, with measured adsorption coefficients being less than 1 cm(3) g(-1) for all studied soils. There was a highly significant inverse relationship between the measured NTO adsorption coefficients and soil pH (P = 0.00011), indicating the role of NTO and soil charge in adsorption processes. In kinetic experiments, 1st order transformation rate constant estimates ranged between 0.0004 h(-1) and 0.0142 h(-1) (equivalent to half-lives of 72 and 2 d, respectively), and correlated positively with organic carbon in the soil. Total attenuation of NTO was higher in untreated versus sterilized samples, suggesting that NTO was being biodegraded. The information presented herein can be used to help evaluate NTO potential for natural attenuation in soils.
authors.affiliation: Dept. of Soil, Water, and Environmental Science, University of Arizona, 1177 E. Fourth St. PO Box 210038, Shantz Bldg. #38, Tucson, AZ 85721-0038, USA.
authors.forename: Noah
authors.initials: N
authors.lastname: Mark
authors.affiliation: Dept. of Soil, Water, and Environmental Science, University of Arizona, 1177 E. Fourth St. PO Box 210038, Shantz Bldg. #38, Tucson, AZ 85721-0038, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Arthur
authors.affiliation: Dept. of Soil, Water, and Environmental Science, University of Arizona, 1177 E. Fourth St. PO Box 210038, Shantz Bldg. #38, Tucson, AZ 85721-0038, USA; Biosphere 2, University of Arizona, Marshall Building, Room 523, 845 N, Park Avenue, Tucson, AZ 85721-0158, USA. Electronic address: dontsova@email.arizona.edu.
authors.forename: Katerina
authors.initials: K
authors.lastname: Dontsova
authors.affiliation: Dept. of Soil, Water, and Environmental Science, University of Arizona, 1177 E. Fourth St. PO Box 210038, Shantz Bldg. #38, Tucson, AZ 85721-0038, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Brusseau
authors.affiliation: Cold Regions Research and Engineering Laboratory, U.S. Army Engineer Research and Development Center, 72 Lyme Road, Hanover, NH 03755-1290, USA.
authors.forename: Susan
authors.initials: S
authors.lastname: Taylor
mesh_terms: D000327:Adsorption; D001673:Biodegradation, Environmental; D053834:Explosive Agents / Q000032:analysis*; D007700:Kinetics; D008962:Models, Theoretical; D009574:Nitro Compounds / Q000032:analysis*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*; D014230:Triazoles / Q000032:analysis*
chemical_list: C505897:3-nitro-1,2,4-triazol-5-one; D053834:Explosive Agents; D009574:Nitro Compounds; D012987:Soil; D012989:Soil Pollutants; D014230:Triazoles
keywords: Energetic materials; Insensitive munitions; NTO; Soil adsorption