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2003 Progress Report: Development and Evaluation of Field Sensors for Monitoring Bioaugmentation with Anaerobic Dehalogenating Cultures for In-Situ Treatment of TCE
EPA Grant Number: R828772C007Subproject: this is subproject number 007 , 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: Development and Evaluation of Field Sensors for Monitoring Bioaugmentation with Anaerobic Dehalogenating Cultures for In-Situ Treatment of TCE
Investigators: Ingle, James D.
Institution: Oregon State University
EPA Project Officer: Lasat, Mitch
Project Period: September 1, 2001 through August 31, 2003
Project Period Covered by this Report: September 1, 2003 through August 31, 2004
Project Amount: Refer to main center abstract for funding details.
RFA: Hazardous Substance Research Centers - HSRC (2001)
Research Category: Hazardous Waste/Remediation
Description:
Objective:The objectives of this research project are to: (1) refine and use redox sensors based on redox indicators as monitoring tools for assessing and optimizing redox conditions for treatment of perchloroethylene (PCE) and trichloroethylene (TCE) with dehalogenating cultures; (2) deploy, evaluate, and refine redox indicators for online monitoring of the redox conditions in two collaborative situations involving a bioaugmentation approach; and (3) understand the nature of the redox conditions under which dechlorination microbial processes occur.
Rationale. Better online monitoring techniques for redox status are needed for: (1) the initial assessment of laboratory samples or models and subsurface conditions at a site; (2) continued assessment of the progress of remediation; and (3) control of injections of amendments (such as substrates, nutrients) during remediation. We have shown that redox sensors based on redox indicators exhibit promise for monitoring environmental redox levels. Research is needed to: (1) understand the nature of the response of these indicators; (2) improve the monitoring devices for practical use; and (3) demonstrate that these devices can be employed for online monitoring of the status of anaerobic dehalogenating cultures in laboratory systems.
Approach. Redox indicators immobilized on transparent films have been shown to be able to differentiate between different microbial redox levels (Fe(III)-reducing, sulfate-reducing, methanogenic). These redox indicator flow sensors will be deployed in two primary situations for calibration and demonstration of their applicability: (1) continuous monitoring of redox conditions of cultures inside bioreactors or microcosm bottles as a tool for the optimizing conditions for effective dechlorination of PCE and TCE with enriched halorespiratory cultures; and (2) online monitoring of the redox status of the material in a physical aquifer model (PAM) bioaugmented with the developed dehalogenating cultures. The design and characteristics of the redox sensor monitoring systems will be improved for low-oxygen permeation and portability for easy operation in the field.
Progress Summary:We have refined the portable, immobilized redox-monitoring system and used it to monitor sulfate-reducing and methanogenic conditions in a PAM containing a wastewater slurry. We also used it for dechlorinating cultures in bioreactors and modified microcosm bottles. The enriched dechlorinating culture (Lewis Semprini laboratory) was loaded into our bioreactors and microcosm bottles to calibrate the response of the redox indicators to the dechlorination of PCE. The indicator data support the concept that the dechlorinating process is increasingly reducing as PCE is dechlorinated, with the most reducing step in the process being the dechlorination of vinyl chloride to ethene. Specifically, the reduction of Thionine indicates degradation of PCE and formation of TCE and cis-dichloroethylene; whereas approximately 50 percent reduction of Cresyl Violet (CV) correlates to the formation of vinyl chloride and the production of ethane, which only is observed when CV is nearly or fully reduced. We now are more closely working with Dr. Semprini and his students to address concerns about oxygen contamination during culture transfer steps and while monitoring with our redox flow monitoring system. Refining techniques for transfer of highly oxygen-sensitive cultures is critical for eventual column and PAM studies.
We have developed a method to precipitate finely divided platinum particles into membranes with immobilized indicators through reduction of platinum (Pt2+) solutions. H2 levels as low as 0.01 percent by volume in the headspace reduce the indicator in the platinum embedded membranes. The indicator Phenosafranine (PSaf) is useful for monitoring dechlorinating cultures because, without Pt, PSaf is not reduced by reductants in dechlorinating cultures. Reduction of a PSaf membrane with embedded Pt indicates active fermentation and H2 production necessary for dechlorination. The rate of reduction of the indicator changes with varying H2 concentrations. Although the results are preliminary, this approach could be the basis for a convenient and inexpensive method to determine if H2 concentrations in cultures are sufficient for an effective dechlorination laboratory without the need to run expensive gas chromatography testing. Methods to lower the detection limit will be explored.
Future Activities:We will: (1) refine and use redox sensors, and assess and optimize redox conditions; (2) deploy, evaluate, and refine redox indicators; and (3) seek to understand the nature of redox conditions.
Journal Articles:No journal articles submitted with this report: View all 1 publications for this subproject
Supplemental Keywords:risk assessment, methods/techniques, bioremediation, groundwater, microbial activity, ecosystem protection, environmental exposure and risk, waste, water, aquatic ecosystem restoration, chemical engineering, engineering, chemistry, physics, environmental chemistry, environmental engineering, groundwater remediation, hazardous, hazardous waste, remediation, restoration, perchloroethylene, PCE, tetrachloroethene, trichloroethylene, TCE, trichloroethene, TCE degradation, advanced treatment technologies, aquatic ecosystems, aquifer remediation, aquifer remediation design, bioaugmentation, biodegradation, bioremediation model, biotechnology, contaminated aquifers, contaminated groundwater, dechlorination, degrade trichloroethylene, dehalogenate, dehalogenation, groundwater pollution, hazardous waste treatment, in situ remediation, in situ treatment, in situ bioremediation, in situ biotransformation, microbial degradation, microbiology, monitoring, push-pull test, redox tools, reductive dechlorination, physical aquifer model, PAM. , Ecosystem Protection/Environmental Exposure & Risk, Water, Scientific Discipline, Waste, RFA, Remediation, Engineering, Chemistry, & Physics, Restoration, Chemical Engineering, Aquatic Ecosystem Restoration, Hazardous Waste, Environmental Engineering, Environmental Chemistry, Groundwater remediation, Hazardous, Bioremediation, dehalogenation, bioaugmentation, biodegradation, microbial degradation, in-situ biotransformation, biotechnology, groundwater, monitoring, contaminated aquifers, aquifer remediation design, reductive dehalogenation, groundwater pollution, redox tools, in-situ bioremediation, bioremediation model, aquatic ecosystems, microbiology, groundwater contamination, degrade trichloroethylene, TCE, in situ treatment, reductive dechlorination, TCE degradation, advanced treatment technologies, contaminated groundwater, hazardous waste treatment, dehalogenate, dechlorination, in situ remediation, aquifer remediation
Relevant Websites:
http://wrhsrc.oregonstate.edu/ 
Progress and Final Reports:
2001 Progress Report
Original Abstract
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