Final Report: Phytoremediation and Modeling of Land Contaminated by Hydrons

EPA Grant Number: R825414
Title: Phytoremediation and Modeling of Land Contaminated by Hydrons
Investigators: Munster, Clyde , Corapcioglu, Yavuz , Drew, Malcolm
Institution: Texas A & M University
EPA Project Officer: Lasat, Mitch
Project Period: October 28, 1996 through October 27, 1999 (Extended to January 31, 2001)
Project Amount: $452,020
RFA: DOE/EPA/NSF/ONR Joint Program on Bioremediation (1996) RFA Text |  Recipients Lists
Research Category: Hazardous Waste/Remediation , Land and Waste Management

Objective:

The two primary general objectives of this research project were to: (1) evaluate the effectiveness of a warm season grass (Johnsongrass) and a cool season prairie grass (Canada wild-rye) in the phytoremediation of soil contaminated with a recalcitrant mixture of a polybrominated bromobiphenyl (2,2',5,5'-tetrabromobiphenyl), a polycyclic aromatic hydrocarbon (dibenzo(a,h)anthracene) and TNT (2,4,6?trinitrotoluene) using box and column field lysimeter studies; and (2) use the field data to calibrate and validate a recently developed bioremediation model that is capable of simulating the removal and degradation of organic chemicals from the soil by plant roots and their rhizosphere.

The specific objectives of the research were to:

  1. Determine the amounts of 2,2',5,5'-tetrabromobiphenyl, dibenzo(a,h)anthracene and 2,4,6-trinitrotoluene that are extractable by Canada wild-rye (Elymus canadensis) and Johnsongrass (Sorghum halapense) during three growing seasons and in rotation using box and column lysimeters.

  2. Quantify the concentrations of 2,2',5,5'-tetrabromobiphenyl, dibenzo(a,h)anthracene and 2,4,6-trinitrotoluene in the leachate collected in the lysimeter studies.

  3. Quantify the dissipation of 2,2',5,5'-tetrabromobiphenyl, dibenzo(a,h)anthracene and 2,4,6-trinitrotoluene in the soil for the lysimeter studies.

  4. Validate and calibrate an existing mechanistic model that simulates organic contaminate transport and root uptake from soil as documented in Objectives 1?3. This will require measurement of some soil physical properties as well as root growth characteristics for the grasses grown in soil contaminated by 2,2',5,5'-tetrabromobiphenyl, dibenzo(a,h)anthracene and 2,4,6-trinitrotoluene.

  5. Demonstrate the use of this model as a predictive tool that can be used to quantify the effectiveness of phytoremediation over a wide range of soil and plant conditions.

Summary/Accomplishments (Outputs/Outcomes):

Chemical losses during this 2-year field lysimeter experiment were similar for both lysimeters, at all depths, and between all experimental treatments. The largest and most rapid loss in soil-chemical concentration was TNT, which decreased to < 10 mg kg-1 after 360 days. Chemical concentrations in the herbage were low. The maximum concentration was for the PBB at 64 µg/kg in Johnsongrass on day 185 after germination. In contrast, the chemical concentrations in the roots for the PBB and the PAH were quite high, whereas TNT concentrations in the roots were also low. The maximum concentration in the Johnsongrass roots for the PBB was 1,010 µg/kg, and for the PAH it was 5,000 µg/kg, both on day 32 after germination.

Enumeration of soil microorganisms reveals a robust population in both the bulk soil and root rhizosphere soil, but there were no significant differences between bulk and rhizosphere soil populations.

The simulation results using the phytoremediation computer model were evaluated. Thus far, simulations with TNT demonstrate that the present model can predict contaminant concentration losses with time and depth under actual field conditions. The simulation of the other contaminates continues to be evaluated in associated research projects.

Conclusions. The field lysimeter experiments resulted in the measurement of the phytoremediation parameters necessary for the validation and calibration of the phytoremediation simulation model. The phytoremediation computer model successfully simulated TNT concentrations in the soil when compared with field-measured values. The TNT simulations demonstrate that the phytoremediation model can predict contaminant concentration with time and depth under actual field conditions. The validated and calibrated computer model may provide insight into the selection and optimization of phytoremediation at contaminated sites.


Journal Articles on this Report : 5 Displayed | Download in RIS Format

Other project views: All 16 publications 5 publications in selected types All 5 journal articles
Type Citation Project Document Sources
Journal Article Chang Y, Corapcioglu M. Effect of roots on water flow in unsaturated soils. Journal of Irrigation and Drainage Engineering 1997;123(3):202-209. R825414 (Final)
  • Abstract: ASCE-Abstract
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  • Journal Article Chang Y-Y, Corapcioglu MY. Plant-enhanced subsurface bioremediation of nonvolatile hydrocarbons. Journal of Environmental Engineering-ASCE 1998;124(2):162-169. R825414 (Final)
    R828598C696 (Final)
  • Abstract: ASCE
    Exit
  • Journal Article Sung K, Corapcioglu MY, Drew MC, Munster CL. Plant contamination by organic pollutants in phytoremediation. Journal of Environmental Quality 2001;30(6):2081-2090. R825414 (Final)
    R826694C696 (2000)
    R826694C696 (Final)
    R828598C696 (Final)
  • Abstract from PubMed
  • Full-text: JEQ-Full Text HTML
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  • Abstract: JEQ-Abstract
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  • Other: JEQ-Full Text PDF
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  • Journal Article Sung K, Yavuz CM, Drew MC. Heat and mass transfer in the vadose zone with plant roots. Journal of Contaminant Hydrology 2002;57(1-2):99-127. R825414 (Final)
    R826694C696 (2000)
    R826694C696 (Final)
    R828598C696 (Final)
  • Abstract from PubMed
  • Full-text: Science Direct-Full Text HTML
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  • Abstract: Science Direct-Abstract
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  • Other: Science Direct-Full Text PDF
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  • Journal Article Sung K, Corapcioglu MY, Drew MC. Plant aided bioremediation in the vadose zone: model development and applications. Journal of Contaminant Hydrology 2004;73(1-4):65-98. R825414 (Final)
    R826694C696 (2000)
    R826694C696 (Final)
  • Abstract from PubMed
  • Full-text: Science Direct
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  • Abstract: Science Direct
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  • Other: Science Direct
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  • Supplemental Keywords:

    phytoremediation, PAHs, PBBs, TNT, lysimeter experiment, computer model simulation;, Scientific Discipline, Toxics, Waste, Ecosystem Protection/Environmental Exposure & Risk, Bioavailability, Contaminated Sediments, Remediation, Environmental Chemistry, HAPS, pesticides, Bioremediation, Biology, sediment treatment, Canada wild rye grass, biostabilization of PCBs, contaminant transport, polychlorinated biphenyls (PCBs), rhizospheric, hydrocarbon, bioremediation model, biodegradation, PCBs, sediment transport, transport contaminants, contaminated sediment, chemical contaminants, PAH, contaminants in soil, polychlorinated biphenyls, PCB, bioremediation of soils, recalcitrant hydrocarbons, bioremediation simulation, contaminant release, hydrocarbons, phytoremediation, TNT, leachate, vegetated soil, greenhouse experiment

    Progress and Final Reports:

    Original Abstract
  • 1997
  • 1998
  • 1999 Progress Report
  • 2000