title: Column transport studies of 3-nitro-1,2,4-triazol-5-one (NTO) in soils.
abstract: Development of the new, insensitive, energetic compound, NTO (3-nitro-1,2,4-triazol-5-one), creates need for the data on NTO's fate and transport to predict its behavior in the environment and potential for groundwater contamination. To measure the transport of NTO in soils, we conducted miscible-displacement experiments under steady state and interrupted flow conditions using eight soils having varying physical and geochemical properties. The breakthrough curve (BTC) data were analyzed using temporal moment analysis and simulated using HYDRUS-1D to determine transport parameters and better understand the mechanisms of sorption and transformation. Parameters determined from the miscible-displacement study were compared to results obtained from batch experiments conducted for the same soils, and examined in relation to soil properties. Column NTO linear adsorption coefficients (Kd) were low and correlated well (P = 0.000049) with measurements from the batch studies. NTO transformation rate constants increased and NTO recovery decreased with increase in soil organic carbon (OC) content. Autoclaved soils had slower transformation rates and greater NTO recoveries indicating that microorganisms play a role in NTO transformation. In addition, the transformation rate increased with time in soils with higher OC. Monod-type kinetics was implemented in HYDRUS-1D to simulate the observed increase in transformation rate with time. We think this phenomenon is due to bacterial growth. Results indicate very low adsorption of NTO in a range of soils, but natural attenuation through transformation that, depending on soil OC content and hydraulic residence time, could result in complete removal of NTO.
authors.affiliation: Dept. of Soil, Water, and Environmental Science, Univ. 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, Univ. 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, Univ. 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, Univ. 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
authors.affiliation: Dept of Environmental Sciences, Univ. of California Riverside, Riverside, CA 92521, USA.
authors.forename: Jiří
authors.initials: J
authors.lastname: Šimůnek
mesh_terms: D000327:Adsorption; D060587:Groundwater / Q000737:chemistry; D007700:Kinetics; D009574:Nitro Compounds / Q000032:analysis / Q000737:chemistry*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis / Q000737:chemistry*; D014230:Triazoles / Q000032:analysis / Q000737:chemistry*
chemical_list: C505897:3-nitro-1,2,4-triazol-5-one; D009574:Nitro Compounds; D012987:Soil; D012989:Soil Pollutants; D014230:Triazoles
keywords: Energetic materials; Insensitive munitions; NTO; Natural attenuation; Transport