Tracking the Uptake, Translocation, Cycling, and Metabolism of Munitions Compounds in Coastal Marine Ecosystems Using Stable Isotopic Tracer
Abstract
Stable isotope-labeled TNT and RDX were used in benchtop, aquaria, and large mesocosm experiments to quantify the fate these compounds in coastal marine ecosystems. Both compounds underwent conversion to organic derivatives, sediment sorption, uptake and turnover by biota, and mineralization to inert inorganic constituents. The isotope label was used to quantify the magnitude of each of these fates. Biota was a small sink for both TNT and RDX. Bioconcentration factors (BCFs) were several orders of magnitude below those of hydrophobic compounds known to bioaccumulate. Differences between tissue RDX and TNT concentrations and isotope tracer indicated high amounts of internal processing of both compounds after uptake. Abiotic sorption to sediments, while only a minor fate, was higher than that reported for freshwater sediment. Mineralization to inorganic constituents was the dominant fate (50-60 ) for RDX particularly in high organic sediments. Production of an unmeasured aqueous organic derivative was the primary fate for TNT. The BCFs, and uptake and elimination constants for biota can benefit stakeholders because they can be directly used to parameterize transport and/or risk models. Isotopic evidence of mineralization provides proof of concept that similar tracer approaches can be used at contaminated sites to evaluate natural attenuation in-situ.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 2019
- Accession Number
- AD1084223
Entities
People
- Craig Tobias
Organizations
- University of Connecticut