Tracing the cycling and fate of the explosive 2,4,6-trinitrotoluene in coastal marine systems with a stable isotopic tracer, 15N-[TNT]

Environmental Science & Technology
By: , and 

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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 (15N-[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 δ15N analysis of sediments, SPM, and tissues revealed large quantities of 15N 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 15N 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.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Tracing the cycling and fate of the explosive 2,4,6-trinitrotoluene in coastal marine systems with a stable isotopic tracer, 15N-[TNT]
Series title Environmental Science & Technology
DOI 10.1021/acs.est.5b02907
Volume 49
Issue 20
Year Published 2015
Language English
Publisher American Chemical Society
Contributing office(s) National Research Program - Eastern Branch, Toxic Substances Hydrology Program
Description 9 p.
First page 12223
Last page 12231
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