title: Tracing the Cycling and Fate of the Explosive 2,4,6-Trinitrotoluene in Coastal Marine Systems with a Stable Isotopic Tracer, (15)N-[TNT].
abstract: 2,4,6-Trinitrotoluene (TNT) has been used as a military explosive for over a hundred years. Contamination concerns have arisen as a result of manufacturing and use on a large scale; however, despite decades of work addressing TNT contamination in the environment, its fate in marine ecosystems is not fully resolved. Here we examine the cycling and fate of TNT in the coastal marine systems by spiking a marine mesocosm containing seawater, sediments, and macrobiota with isotopically labeled TNT ((15)N-[TNT]), simultaneously monitoring removal, transformation, mineralization, sorption, and biological uptake over a period of 16 days. TNT degradation was rapid, and we observed accumulation of reduced transformation products dissolved in the water column and in pore waters, sorbed to sediments and suspended particulate matter (SPM), and in the tissues of macrobiota. Bulk δ(15)N analysis of sediments, SPM, and tissues revealed large quantities of (15)N beyond that accounted for in identifiable derivatives. TNT-derived N was also found in the dissolved inorganic N (DIN) pool. Using multivariate statistical analysis and a (15)N mass balance approach, we identify the major transformation pathways of TNT, including the deamination of reduced TNT derivatives, potentially promoted by sorption to SPM and oxic surface sediments.
authors.affiliation: Department of Marine Sciences, University of Connecticut , 1080 Shennocossett Road, Groton, Connecticut 06340, United States.|Global Aquatic Research LLC, 6276 Ridge Road, Sodus, New York 14551, United States.
authors.forename: Richard W
authors.initials: RW
authors.lastname: Smith
authors.affiliation: Department of Marine Sciences, University of Connecticut , 1080 Shennocossett Road, Groton, Connecticut 06340, United States.
authors.forename: Penny
authors.initials: P
authors.lastname: Vlahos
authors.affiliation: U.S. Geological Survey, 431 National Center, Reston, Virginia 20192, United States.
authors.forename: J K
authors.initials: JK
authors.lastname: Böhlke
authors.affiliation: Department of Marine Sciences, University of Connecticut , 1080 Shennocossett Road, Groton, Connecticut 06340, United States.
authors.forename: Thivanka
authors.initials: T
authors.lastname: Ariyarathna
authors.affiliation: Department of Marine Sciences, University of Connecticut , 1080 Shennocossett Road, Groton, Connecticut 06340, United States.
authors.forename: Mark
authors.initials: M
authors.lastname: Ballentine
authors.affiliation: Department of Marine Sciences, University of Connecticut , 1080 Shennocossett Road, Groton, Connecticut 06340, United States.
authors.forename: Christopher
authors.initials: C
authors.lastname: Cooper
authors.affiliation: Naval Air Warfare Center Weapons Division, Chemistry Division, China Lake, California 93555, United States.
authors.forename: Stephen
authors.initials: S
authors.lastname: Fallis
authors.affiliation: Naval Air Warfare Center Weapons Division, Chemistry Division, China Lake, California 93555, United States.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Groshens
authors.affiliation: Department of Marine Sciences, University of Connecticut , 1080 Shennocossett Road, Groton, Connecticut 06340, United States.
authors.forename: Craig
authors.initials: C
authors.lastname: Tobias
mesh_terms: D017753:Ecosystem; D007553:Isotope Labeling; D008903:Minerals / Q000737:chemistry; D009584:Nitrogen / Q000032:analysis; D009587:Nitrogen Isotopes; D052638:Particulate Matter / Q000032:analysis; D012623:Seawater / Q000737:chemistry*; D012995:Solubility; D014303:Trinitrotoluene / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D008903:Minerals; D009587:Nitrogen Isotopes; D052638:Particulate Matter; D014874:Water Pollutants, Chemical; D014303:Trinitrotoluene; D009584:Nitrogen