Grantee Research Project Results
2002 Progress Report: Strategies for Cost-Effective In-situ Mixing of Contaminants and Additives in Bioremediation
EPA Grant Number: R828772C002Subproject: this is subproject number 002 , 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: Solutions for Energy, AiR, Climate and Health Center (SEARCH)
Center Director: Bell, Michelle L.
Title: Strategies for Cost-Effective In-situ Mixing of Contaminants and Additives in Bioremediation
Investigators: Kitanidis, Peter K. , Criddle, Craig C.
Institution: Stanford University
EPA Project Officer: Aja, Hayley
Project Period: September 1, 2001 through August 31, 2003
Project Period Covered by this Report: September 1, 2001 through August 31, 2002
Project Amount: Refer to main center abstract for funding details.
RFA: Hazardous Substance Research Centers - HSRC (2001) Recipients Lists
Research Category: Hazardous Waste/Remediation , Land and Waste Management
Objective:
The objectives of this research project are to: (1) develop and critically evaluate principles and strategies for mixing, using recirculation units, pairs of extraction-injection wells, sparging, biocurtains, and combined systems and operations that are sequenced in time and space; (2) develop methods for cost-effective chemical delivery and mixing, prevention of clogging, and hydraulic control; (3) define the range of application of these methods and compare them on the same basis in terms of effectiveness and cost; (4) synthesize available knowledge and previous experience on flow, transport, and biochemical reactions using results from field-scale studies; (5) advance and test theories for subsurface mixing at field scales through hydrodynamic dispersion, partitioning, fingering, etc; and (6) develop a set of tools and guidelines for the design of cost-effective in situ delivery and mixing systems.
In the absence of effective mixing and chemical delivery schemes, technologies that could potentially remove contaminants from geologic formations and groundwater will not be translated to practice. This is because these methods usually require the injection of growth promoters (in situ bioremediation), chemical additives (e.g., surfactant-enhanced remediation), or cells (bioaugmentation). To achieve successful mixing and chemical delivery at the field scale, we need to: (1) create a sufficiently large in situ reactor; and (2) regulate residence times.
Progress Summary:
In this research project, we study principles of mixing and the performance of mixing schemes, and we evaluate a broad range of existing and new full-scale mixing and chemical delivery schemes through comprehensive mathematical, technical, and economic analysis. We are guided by case studies.
We have focused on the design of an effective chemical delivery and mixing scheme for in situ bioremediation of uranium (VI) at Oak Ridge National Laboratory. This is a challenging site, characterized by complex hydrogeology and biogeochemistry. The subsurface material is highly weathered saprolite. In addition to high uranium concentration, the pH is exceptionally low, at about 3.5, and nitrates are exceptionally high, at about 10 g/L. Nitrate needs to be removed and the pH needs to be raised in a controlled fashion (to prevent clogging of the porous medium from precipitation of aluminum). The speciation of U(VI) and its mobility is controlled strongly by the pH.
Future Activities:
An elaborate onsite treatment plant has been designed and will be combined with a multistep in situ treatment experiment. They will be implemented in the next few months. We have developed mathematical models of flow, transport, and biogeochemistry and are comparing predictions with the results of experiments and field tests.
Supplemental Keywords:
groundwater, chemical delivery, mixing, biostimulation, cost-benefit, risk management, waste, biochemistry, bioremediation, environmental chemistry, environmental engineering, hazardous, hazardous waste, remediation, biodegradation, biostimulation, biotransformation, chemical mixing, chlorinated solvents, extraction of metals, fate and transport modeling, field-scale studies, field studies, geochemistry, hazardous waste treatment, heavy metals, in situ remediation, in situ bioremediation, in situ biotransformation, mathematical models, mathematical modeling, metal compounds, metal wastes, organic solvents., RFA, Scientific Discipline, Waste, Hazardous, Remediation, Environmental Chemistry, Hazardous Waste, Biochemistry, Bioremediation, Environmental Engineering, biostimulation, heavy metals, biotransformation, geochemistry, in-situ biotransformation, field scale studies, in-situ bioremediation, hazardous waste treatment, fate and transport modeling, biodegradation, in situ remediation, extraction of metals, sparging systems, mathematical models, metal compounds, metal wastes, organic solvents, mathmatical modeling, field studies, chlorinated solvents, recirculationRelevant Websites:
Progress and Final Reports:
Original AbstractMain Center Abstract and Reports:
R828772 Solutions for Energy, AiR, Climate and Health Center (SEARCH) 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
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
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.