Final Report: Phytoremediation of TNT Contaminated Soil and Groundwaters

EPA Grant Number: R825513C013
Subproject: this is subproject number 013 , established and managed by the Center Director under grant R825513
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: HSRC (1989) - South and Southwest HSRC
Center Director: Reible, Danny D.
Title: Phytoremediation of TNT Contaminated Soil and Groundwaters
Investigators: Saunders, F. Michael , Hughes, Joseph B , Constant, William David , Pavlostathis, Spyros G. , Thibodeaux, Louis J. , Valsaraj, Kalliat T. , Shanks, Jacqueline V.
Institution: Georgia Institute of Technology , Rice University , Louisiana State University - Baton Rouge
Current Institution: Georgia Institute of Technology , Louisiana State University - Baton Rouge , Rice University
EPA Project Officer: Hahn, Intaek
Project Period: January 1, 1994 through January 1, 1996
Project Amount: Refer to main center abstract for funding details.
RFA: Hazardous Substance Research Centers - HSRC (1989) RFA Text |  Recipients Lists
Research Category: Hazardous Substance Research Centers , Land and Waste Management


The overall objective of the project was to investigate the use of biochemical reductive processes for remediation of contaminated soils. The specific goal was the development and pilot demonstration of the in-situ remediation of trinitrotoluene (TNT)-contaminated soil using an initial reduction of TNT with natural organic matter as catalysts under controlled conditions followed by enhanced mineralization under oxidizing conditions.

Summary/Accomplishments (Outputs/Outcomes):

Each of the participating institutions had a specific set of objectives on which they worked but overall all pilot-scale demonstration projects and associated research was performed at Georgia Tech, all degradation pathway studies were done at Rice while LSU performed the analytical studies on transport behavior via static and dynamic components.

Project accomplishments are summarized below and are included in project reports developed at the three participating universities.

  • Demonstrated that aquatic plants are capable of TNT transformation and that the activity of plants in aquatic plant systems should dominate over that of aerobic bacteria and other microbes associated with aquatic plants in natural-environment systems.
  • Demonstrated that the ability to transform TNT was widespread in aquatic plant species, including but not limited to Myriophyllum, Hydrilla, Elodea, and Salvinia species.
  • Conducted mass balances of TNT on a range of plant systems and confirmed uptake, binding, and excretion as plant processes influencing TNT and TNT-byproduct distribution in plant and aquatic phases.
  • Established that TNT can inhibit plant biochemical processes and can be toxic to plants at elevated concentrations, indicating the critical need to balance plant transformation of TNT with potential inhibitory effects of aqueous-phase TNT on plant metabolic processes.
  • Established the potential for algae species and cyanobacteria (i.e., Anabaena spiroides) to transform TNT in aquatic systems.
  • Established solubility of TNT as a function of pH and temperature on reference and field samples of TNT. An empirical relationship was developed for solubility of TNT that indicated solubility increased with temperature and decreased with pH.
  • Demonstrate diffusive limitations of removal of TNT from soils and established an average effective diffusivity value of 1.2x10-6 cm2/s for low TNT concentrations (1-10 mg/kg). Slow transport of TNT from a TNT-contaminated, soil bed was established as a major limiting factor in phytoremediation systems to be used to remediate contaminated soils at ammunition plant sites.
  • Dissolution characteristics of TNT were established under various hydrodynamic conditions in stirred batch reactors with reference and field TNT compounds. Dissolution properties were used in prediction models for transport on TNT from contaminated soils to overlying waters for transformation by plants.
  • Established that photolysis of TNT and TNT byproducts by sunlight in aquatic-plants systems was not a significant contributor to the transformation of TNT in phytoremediation systems.
  • Evaluated the potential of aerobic bacterial populations to mineralize soluble TNT metabolites, e.g., amino-nitrotoluenes produced through aquatic-plant transformation processes. No mineralization of these soluble byproducts was observed for these microbes.
  • Verified that intra- and extra-cellular products produced by plants from transformation of TNT were distinct from those produced by bacterial species, further confirming the active role of plants in the remediation of TNT.
  • Developed methods of analysis for conducting mass balance and separation of known TNT intermediates.
  • A field-scale model for a hypothetical TNT remediation unit was developed. This two-stage model included kinetic-parameter estimates for equipment design and operation of a riffle-bed extraction system coupled with a subsequent phytoremediation system. The simplified model developed was shown to closely simulate natural systems for relative ease in field deployment.
  • Confirmed plant-based degradation of aqueous-phase TNT in aquatic plant lagoons with mono- and multi-culture plant populations in pilot-scale systems using a TNT contaminated water at a concentration of 10 mg/L. This system was operated under ambient weather conditions for three seasons and confirmed utility of aquatic plant systems in ultimate reclamation of TNT-contaminated soils.

  • Journal Articles on this Report : 11 Displayed | Download in RIS Format

    Other subproject views: All 32 publications 13 publications in selected types All 11 journal articles
    Other center views: All 392 publications 154 publications in selected types All 106 journal articles
    Type Citation Sub Project Document Sources
    Journal Article Bhadra R, Spanggord RJ, Wayment DG, Hughes JB, Shanks JV. Characterization of oxidation products of TNT metabolism in aquatic phytoremediation systems of Myrilphyllum aquaticum. Environmental Science & Technology 1999;33(19):3354-3361. R825513C006 (Final)
    R825513C013 (Final)
  • Full-text: ACS Publications Full Text
  • Other: ACS Publications PDF
  • Journal Article Bhadra R, Wayment DG, Hughes JB, Shanks JV. Confirmation of conjugation processes during TNT metabolism by axenic plant roots. Environmental Science & Technology 1999;33(3):446-452. R825513C013 (Final)
  • Full-text: ACS Publications Full Text
  • Other: ACS Publications PDF
  • Journal Article Hughes JB, Shanks J, Vanderford M, Lauritzen J, Bhadra R. Transformation of TNT by aquatic plants and plant tissue cultures. Environmental Science & Technology 1997;31(1):266-271. R825513C013 (Final)
  • Full-text: ACS Full Text (PDF)
  • Journal Article Pavlostathis SG, Comstock KK, Jacobson M, Saunders FM. Transformation of 2,4,6-trinitrotoluene (TNT) by the aquatic plant Myriophyllum spicatum. Environmental Toxicology & Chemistry 1998;17(11):2266-2273. R825513C013 (Final)
    not available
    Journal Article Pavlostathis SG, Jackson GH. Biotransformation of 2,4,6-trinitrotoluene (TNT) in Anabaena sp. Cultures. Environmental Toxicology & Chemistry 1999;18(3):412-419. R825513C013 (Final)
    not available
    Journal Article Pavlostathis SG, Jackson GH. Biotransformation of 2,4,6-trinitrotoluene in a continuous-flow Anabaena sp. system. Water Research 2002;36(7):1699-1706. R825513C013 (Final)
    not available
    Journal Article Qaisi KM, Ro KS, Reible DD, Thibodeaux JL, Valsaraj KT, Constant WD. Transport processes of TNT from flooded highly contaminated surface soil beds. Journal of Environmental Science and Health Part A - Environmental Science and Engineering 1996;31(10):2515-2532. R825513C013 (Final)
    not available
    Journal Article Qaisi KM, Ro KS, Constant WD, Smith ML. Soil-water partitioning and mass transfer kinetics of 2,4,6 TNT in highly contaminated soil. Journal of Environmental Science and Health Part A - Environmental Science and Engineering & Toxic and Hazardous Substance Control 1996;A31(9):2079-2085. R825513C013 (Final)
    not available
    Journal Article Saunders FM, Pavlostathis S, Tiller C, Valsaraj KT, Ro K, Constant WD, Thibodeaux LJ, Hughes J, Shanks J. Using vegetation to clean up TNT-contaminated sites. Centerpoint 1996;3(1):4-6. R825513C013 (Final)
    not available
    Journal Article Valsaraj KT, Qaisi KM, Constant WD, Thibodeaux LJ, Ro KS. Diffusive transport of 2,4,6-trinitrotoluene (TNT) from contaminated soil to overlying water. Journal of Hazardous Materials 1998;59(1):1-12. R825513C013 (Final)
  • Full-text: Science Direct Full Text
  • Abstract: Science Direct Abstract
  • Other: Science Direct PDF
  • Journal Article nderford M, Shanks JV, Hughes JB. Phytotransformation of Trinitrotoluene (TNT) and distribution of metobolic products in Myriphyllum aquaticum. Biotechnology Letters 1997;19(3):277-280. R825513C013 (Final)
    not available

    Supplemental Keywords:

    biotransformation, munition, and remediation., RFA, Scientific Discipline, Waste, Water, Ecology, Chemical Engineering, Contaminated Sediments, Remediation, Environmental Chemistry, Chemistry, Biochemistry, Bioremediation, Ecology and Ecosystems, Biology, Environmental Engineering, plant-based remediation, in situ remediation, contaminated soil, soils, bioremediation of soils, contaminants in soil, biotransformation, phytoremediation, plant mediated contaminants, TNT, munitions

    Progress and Final Reports:

    Original Abstract
  • 1994

  • Main Center Abstract and Reports:

    R825513    HSRC (1989) - South and Southwest HSRC

    Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
    R825513C001 Sediment Resuspension and Contaminant Transport in an Estuary.
    R825513C002 Contaminant Transport Across Cohesive Sediment Interfaces.
    R825513C003 Mobilization and Fate of Inorganic Contaminant due to Resuspension of Cohesive Sediment.
    R825513C004 Source Identification, Transformation, and Transport Processes of N-, O- and S- Containing Organic Chemicals in Wetland and Upland Sediments.
    R825513C005 Mobility and Transport of Radium from Sediment and Waste Pits.
    R825513C006 Anaerobic Biodegradation of 2,4,6-Trinitrotoluene and Other Nitroaromatic Compounds by Clostridium Acetobutylicum.
    R825513C007 Investigation on the Fate and Biotransformation of Hexachlorobutadiene and Chlorobenzenes in a Sediment-Water Estuarine System
    R825513C008 An Investigation of Chemical Transport from Contaminated Sediments through Porous Containment Structures
    R825513C009 Evaluation of Placement and Effectiveness of Sediment Caps
    R825513C010 Coupled Biological and Physicochemical Bed-Sediment Processes
    R825513C011 Pollutant Fluxes to Aquatic Systems via Coupled Biological and Physicochemical Bed-Sediment Processes
    R825513C012 Controls on Metals Partitioning in Contaminated Sediments
    R825513C013 Phytoremediation of TNT Contaminated Soil and Groundwaters
    R825513C014 Sediment-Based Remediation of Hazardous Substances at a Contaminated Military Base
    R825513C015 Effect of Natural Dynamic Changes on Pollutant-Sediment Interaction
    R825513C016 Desorption of Nonpolar Organic Pollutants from Historically Contaminated Sediments and Dredged Materials
    R825513C017 Modeling Air Emissions of Organic Compounds from Contaminated Sediments and Dredged Materials title change in last year to "Long-term Release of Pollutants from Contaminated Sediment Dredged Material"
    R825513C018 Development of an Integrated Optic Interferometer for In-Situ Monitoring of Volatile Hydrocarbons
    R825513C019 Bioremediation of Contaminated Sediments and Dredged Material
    R825513C020 Bioremediation of Sediments Contaminated with Polyaromatic Hydrocarbons
    R825513C021 Role of Particles in Mobilizing Hazardous Chemicals in Urban Runoff
    R825513C022 Particle Transport and Deposit Morphology at the Sediment/Water Interface
    R825513C023 Uptake of Metal Ions from Aqueous Solutions by Sediments
    R825513C024 Bioavailability of Desorption Resistant Hydrocarbons in Sediment-Water Systems.
    R825513C025 Interactive Roles of Microbial and Spartina Populations in Mercury Methylation Processes in Bioremediation of Contaminated Sediments in Salt-Marsh Systems
    R825513C026 Evaluation of Physical-Chemical Methods for Rapid Assessment of the Bioavailability of Moderately Polar Compounds in Sediments
    R825513C027 Freshwater Bioturbators in Riverine Sediments as Enhancers of Contaminant Release
    R825513C028 Characterization of Laguna Madre Contaminated Sediments.
    R825513C029 The Role of Competitive Adsorption of Suspended Sediments in Determining Partitioning and Colloidal Stability.
    R825513C030 Remediation of TNT-Contaminated Soil by Cyanobacterial Mat.
    R825513C031 Experimental and Detailed Mathematical Modeling of Diffusion of Contaminants in Fluids
    R825513C033 Application of Biotechnology in Bioremediation of Contaminated Sediments
    R825513C034 Characterization of PAH's Degrading Bacteria in Coastal Sediments
    R825513C035 Dynamic Aspects of Metal Speciation in the Miami River Sediments in Relation to Particle Size Distribution of Chemical Heterogeneity