Validation of Stable Isotope Ratio Analysis to Document the Biodegradation and Natural Attenuation of RDX

ER-201208

Objective

The objective of this project is to validate a compound-specific isotope analysis (CSIA) method to quantify aerobic and anaerobic biodegradation of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) at field sites. This technique will provide critical information concerning the potential for natural attenuation of RDX at former and current Department of Defense (DoD) installations.

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Technology Description

CSIA is increasingly being applied as an analytical tool to quantify the biodegradation and environmental fate of industrial and military pollutants, including chlorinated solvents, gasoline oxygenates, perchlorate, and explosives. This technique relies on the fact that bacteria biodegrade heavier isotopomers (e.g., RDX with 15N rather than 14N in its structure) more slowly than lighter ones due to the greater bond stability of the heavier molecules, leading to enrichment in the heavier isotopes within the residual parent molecules as biodegradation proceeds. An analysis of stable isotope ratios of a contaminant along the flow path of a plume or in contaminated groundwater compared to the contaminant source material can be used to document degradation and natural attenuation in situ, as well as provide information on specific reaction mechanisms, particularly if isotopes of multiple elements are evaluated. Thus, CSIA is a powerful and versatile technique in environmental assessment.

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Benefits

This project will provide DoD with a validated CSIA approach for quantifying RDX biodegradation at ranges and other field locations with large dilute plumes where in situ or ex situ remedial options are costly or impractical. Because RDX degrades to several terminal products that are common in nature (e.g., HCHO, N2O, NO3-, NO2-, CO2), this methodology may be critical to determining the potential success of monitored natural attenuation (MNA) as a selected remedial option at such locations. At the conclusion of this method validation project, a DoD Guidance Document will be developed to describe the stable isotope approach for RDX in detail and discuss the appropriate application and interpretation of results for MNA applications. (Anticipated Project Completion - 2014)

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Points of Contact

Principal Investigator

Dr. Paul Hatzinger

CB&I Federal Services

Phone: 609-895-5356

Fax: 609-936-9221

Program Manager

Environmental Restoration

SERDP and ESTCP

Document Types

  • Fact Sheet - Brief project summary with links to related documents and points of contact.
  • Final Report - Comprehensive report for every completed SERDP and ESTCP project that contains all technical results.
  • Cost & Performance Report - Overview of ESTCP demonstration activities, results, and conclusions, standardized to facilitate implementation decisions.
  • Technical Report - Additional interim reports, laboratory reports, demonstration reports, and technology survey reports.
  • Guidance - Instructional information on technical topics such as protocols and user’s guides.
  • Workshop Report - Summary of workshop discussion and findings.
  • Multimedia - On demand videos, animations, and webcasts highlighting featured initiatives or technologies.
  • Model/Software - Computer programs and applications available for download.
  • Database - Digitally organized collection of data available to search and access.