2001 Progress Report: Developing and Optimizing Biotransformation Kinetics for the Bio- remediation of Trichloroethylene at NAPL Source Zone Concentrations

EPA Grant Number: R828772C001
Subproject: this is subproject number 001 , established and managed by the Center Director under grant R828772
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: HSRC (2001) - Western Region Hazardous Substance Research Center for Developing In-Situ Processes for VOC Remediation in Groundwater and Soils
Center Director: Semprini, Lewis
Title: Developing and Optimizing Biotransformation Kinetics for the Bio- remediation of Trichloroethylene at NAPL Source Zone Concentrations
Investigators: Semprini, Lewis , Dolan, Mark E.
Institution: Oregon State University
EPA Project Officer: Lasat, Mitch
Project Period: November 1, 2001 through October 31, 2003
Project Period Covered by this Report: November 1, 2001 through October 31, 2002
Project Amount: Refer to main center abstract for funding details.
RFA: Hazardous Substance Research Centers - HSRC (2001) RFA Text |  Recipients Lists
Research Category: Hazardous Waste/Remediation , Land and Waste Management

Objective:

The objectives of this research project are to: (1) develop a culture with the ability to reductively dechlorinate trichloroethylene (TCE) to ethylene at very high concentrations (above 1,000 µM), and in the presence of dense nonaqueous phase liquid (DNAPL); (2) characterize microbial growth and measure maximum substrate utilization rates and half velocity coefficients for successive dechlorinations of TCE to ethylene; (3) characterize the microbial consortium by investigating molecular methods to evaluate the diversity of the mixed culture developed in the kinetic studies; and (4) provide kinetic information and cultures in support of these Center projects: "Development of the Push-Pull Test to Monitor the Bioaugmentation of Dehalogenating Cultures," and "Development and Evaluation of Field Sensors for Monitoring Bioaugmentation With Anaerobic Dehalogenating Cultures for In Situ Treatment of TCE."

Although TCE reductive dechlorination has been demonstrated under a variety of conditions, most laboratory and field projects have been conducted at TCE concentrations of 100 mg/L or less. However, near nonaqueous phase liquid (NAPL), source concentrations of chlorinated aliphatic hydrocarbons approach their solubilities (>1,000 mg/L for TCE, and >150 mg/L for tetrachloroethylene (PCE). Studies with different enrichment cultures isolated from contaminated sites have shown good potential for treatment of high concentrations of PCE and TCE. The cultures have different dehalogenation kinetic properties, which indicate that a more effective enrichment culture might be obtained by combining cultures. Research is needed to optimize the transformation kinetics for the consortium with the ability to reductively dechlorinate high concentrations of TCE and PCE to stoichiometric quantities of ethylene. This project will prove useful for the remediation of chlorinated aliphatic compounds in the NAPL source zone.

Progress Summary:

A culture is being developed that can rapidly degrade high concentrations of PCE and TCE to ethylene by mixing two enrichment cultures. The Point Mugu (PM) enrichment rapidly transforms TCE to vinyl chloride (VC), and slowly transforms VC to ethylene (ETH) at very high PCE and TCE concentrations. The Evanite (EV) enrichment rapidly transforms PCE to cis-1,2-dichloroethylene (DCE) and vinyl chloride to ethylene. By mixing both cultures, we hope to achieve rapid transformation of PCE and TCE to ethylene. Batch kinetic studies are being used to determine optimum electron donors for the transformation, and we will use molecular methods to track the two microbial communities. We also are determining electron transfer efficiencies for halorespiration and hydrogen thresholds. We also will evaluate the effect of varying environmental conditions on reductive dechlorination kinetics. These conditions include the apparent oxidation/reduction potential, pH, electron donor type and concentration, and hydrogen partial pressure.

Kinetic studies are being performed to characterize the three different mixed cultures: PM culture, EV culture, and a binary mixed BM culture containing PM and EV cultures. The PM culture showed reductive dechlorination of TCE up to a concentration of 3.4 mM, but dechlorinated PCE at a very slow rate. The PM culture rapidly dechlorinates TCE and cis-DCE to VC, but slowly transforms VC to ETH. The EV enrichment is capable of reductively dechlorinating PCE at its solubility limit (0.9 mM), and completely dechlorinates PCE to ETH, but slowly transforms cis-DCE to VC. The kmaxX of PM culture for PCE, TCE, cis-DCE, and VC at 20°C were found to be 1.4, 102, 1,280, and 40 µM/day with KS values of 1.3, 5.1, 8.3, and 604 µM, respectively. These kinetic values for PCE and VC explain why PCE and VC reductively were dechlorinated at very slow rates by PM culture. The kmaxX values of EV culture for PCE, TCE, cis-DCE, and VC were 104, 95, 65, and 205 µM/day, with KS values of 2.8, 1.8, 4.2, and 51 µM, respectively. These results reflect why the EV culture slowly transforms cis-DCE to VC. Kinetic studies currently are being performed on PCE, TCE, cis-DCE, and VC transformation by the binary mixed culture. Work also is in progress to better characterize these cultures using molecular techniques, and to quantify the dehalogenators that are present to determine the kmax values and to estimate growth yield. Tests also are planned to assess the long-term stability of the binary enrichment in maintaining the observed transformation rates. Model simulations with these kinetic values will be compared with the results from batch reactor studies containing PCE/ NAPL.

Future Activities:

Future activities include continuing culture development, as well as continuing kinetic studies to make further observations, and to discover and present more detailed conclusions.


Journal Articles on this Report : 1 Displayed | Download in RIS Format

Other subproject views: All 2 publications 1 publications in selected types All 1 journal articles
Other center views: All 158 publications 63 publications in selected types All 60 journal articles
Type Citation Sub Project Document Sources
Journal Article Yu S, Semprini L. Comparison of trichloroethylene reductive dehalogenation by microbial communities stimulated on silicon-based organic compounds as slow-release anaerobic substrates. Water Research 2002;36(20):4985-4996. R828772 (2002)
R828772 (Final)
R828772C001 (2001)
  • Abstract from PubMed
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  • Supplemental Keywords:

    groundwater, reductive dechlorination, microbial activity, nonaqueous phase liquids, NAPLs, environmental chemistry, groundwater remediation, hazardous waste, trichloroethylene, TCE, TCE degradation, bioremediation, biotransformation, chemical mixtures, chlorinated organic compounds, chlorinated solvents., RFA, Scientific Discipline, Waste, TREATMENT/CONTROL, POLLUTANTS/TOXICS, Chemical Engineering, Remediation, Environmental Chemistry, Treatment Technologies, Chemicals, Hazardous Waste, Bioremediation, Groundwater remediation, Hazardous, Environmental Engineering, dechlorination, NAPL, Trichloroethylene, chlorinated organic compounds, TCE degradation, biotransformation, reductive dechlorination, chlorinated organics, reductive dechlorination rates, NAPLs, chlorinated solvents, TCE

    Relevant Websites:

    http://wrhsrc.orst.edu/ Exit

    Progress and Final Reports:

    Original Abstract
  • 2002
  • Final

  • Main Center Abstract and Reports:

    R828772    HSRC (2001) - Western Region Hazardous Substance Research Center for Developing In-Situ Processes for VOC Remediation in Groundwater and Soils

    Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
    R828772C001 Developing and Optimizing Biotransformation Kinetics for the Bio- remediation of Trichloroethylene at NAPL Source Zone Concentrations
    R828772C002 Strategies for Cost-Effective In-situ Mixing of Contaminants and Additives in Bioremediation
    R828772C003 Aerobic Cometabolism of Chlorinated Aliphatic Hydrocarbon Compounds with Butane-Grown Microorganisms
    R828772C004 Chemical, Physical, and Biological Processes at the Surface of Palladium Catalysts Under Groundwater Treatment Conditions
    R828772C005 Effects of Sorbent Microporosity on Multicomponent Fate and Transport in Contaminated Groundwater Aquifers
    R828772C006 Development of the Push-Pull Test to Monitor Bioaugmentation with Dehalogenating Cultures
    R828772C007 Development and Evaluation of Field Sensors for Monitoring Bioaugmentation with Anaerobic Dehalogenating Cultures for In-Situ Treatment of TCE
    R828772C008 Training and Technology Transfer
    R828772C009 Technical Outreach Services for Communities (TOSC) and Technical Assistance to Brownfields Communities (TAB) Programs
    R828772C010 Aerobic Cometabolism of Chlorinated Ethenes by Microorganisms that Grow on Organic Acids and Alcohols
    R828772C011 Development and Evaluation of Field Sensors for Monitoring Anaerobic Dehalogenation after Bioaugmentation for In Situ Treatment of PCE and TCE
    R828772C012 Continuous-Flow Column Studies of Reductive Dehalogenation with Two Different Enriched Cultures: Kinetics, Inhibition, and Monitoring of Microbial Activity
    R828772C013 Novel Methods for Laboratory Measurement of Transverse Dispersion in Porous Media
    R828772C014 The Role of Micropore Structure in Contaminant Sorption and Desorption