Grantee Research Project Results

2004 Progress Report: Assessment of Electrokinetic Injection of Amendments for Remediation of Acid Mine Drainage

EPA Grant Number: R829515C011
Subproject: this is subproject number 011 , established and managed by the Center Director under grant R829515
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: Center for Comprehensive, optimaL, and Effective Abatement of Nutrients
Center Director: Arabi, Mazdak
Title: Assessment of Electrokinetic Injection of Amendments for Remediation of Acid Mine Drainage
Investigators: Carlson, Kenneth H. , Pruden, Amy
Institution: Colorado School of Mines , Colorado State University
Current Institution: Colorado State University
EPA Project Officer: Aja, Hayley
Project Period: October 1, 2003 through September 30, 2006
Project Period Covered by this Report: October 1, 2003 through September 30, 2004
RFA: Hazardous Substance Research Centers - HSRC (2001) Recipients Lists
Research Category: Hazardous Waste/Remediation , Land and Waste Management

Objective:

The overall objective of this research project is to evaluate the technical feasibility and cost effectiveness of using electrokinetic injection delivery techniques for the remediation of acid mine drainage (AMD). The four specific objectives of this research project are to:

1. determine the transport efficacy of electrokinetic injection for delivery of organic electron donors;
2. determine the efficacy of unamended electrokinetic injection for removal of metal contaminants as oxides and hydroxides;
3. determine the efficacy of electrokinetic injection for delivery of organic electron donors for stabilizing metals in AMD and characterize the microbial community that is stimulated during various electrokinetic injection process configurations;
4. and compare order of magnitude costs and operational issues of electrokinetic injection of electron donors for AMD remediation.

Progress Summary:

Equipment necessary to run the three soil columns has been purchased. Methods have been developed for the analysis of acetate with ion chromatography. Additionally, a small study was conducted to determine the maximum allowable sample hold time for acetate without the use of a preservative, such as chloroform. Tests currently are underway to determine the transport velocity and uniformity of acetate across clay and sand using two different voltage settings. In addition, modifications of the existing cells have been made to accommodate transport studies examining the impact of groundwater flow on electrokinetic injection efficiency.

All reagents have been ordered and prepared for molecular analysis of the microbial communities. The procedure for denaturing gradient gel electrophoresis has been developed and currently is being used to assess inoculum sources for the biological column experiments. Quantification of the different groups of sulfate reducers will be accomplished with the use of real-time polymerase chain reaction (PCR). This method currently is being optimized for the following groups of sulfate reducers: Desulfotomaculum, Desulfobulbus, Desulfobacterium, Desulfococcus, and Desulfovibrio.

Future Activities:

We will conduct unamended and amended electrokinetic remediation tests in two soil medias and under two voltage settings upon completion of the groundwater flow studies. The amended electrokinetic tests will be studied further under the presence of groundwater flow. Recent results indicate that the presence of hydrogen may be critical for operating a sulfate-reducing bacteria barrier without sulfate reduction stalling before completion. The role of hydrogen in the electrokinetic columns will be studied along with different substrates (lactate and citrate). The later part of 2005 will be spent analyzing the microbial communities present in the soil column studies and determining operational costs of electrokinetic injection.

Publications/Presentations:

See the list of publications/presentations included in the 2004 Annual Report Summary for R829515, which is the overall report for the Rocky Mountain Regional Hazardous Substance Research Center.

Supplemental Keywords:

Technical Outreach Services for Communities, TOSC, Technical Assistance to Brownfields, TAB, groundwater, industry sectors, waste, water, ecological risk assessment, ecology, ecosystems, ecology and ecosystems, environmental chemistry, environmental engineering, geology, geochemistry, toxicology, microbiology, hazardous, hazardous waste, mining-NAIC 21, selenium, acid mine drainage, acid mine runoff, aquatic ecosystems, arsenic, contaminant transport, contaminated sediments, contaminated marine sediment, contaminated waste sites, contaminated sites, contaminated soil, field monitoring, mining-impacted runoff, sediment transport, stream ecosystems, suspended sediment, sediments, mining, remediation, metal mobility, subsurface, extraction of metals, heavy metals, leaching of toxic metals, metal release, metal wastes, metals, metals-contaminated soil, mining wastes, remediation technologies, risk assessment,, RFA, Scientific Discipline, Industry Sectors, INTERNATIONAL COOPERATION, TREATMENT/CONTROL, Waste, Hazardous, Remediation, Ecological Risk Assessment, Waste Treatment, Contaminated Sediments, Hazardous Waste, Geology, Mining - NAIC 21, Bioremediation, Environmental Engineering, contaminant transport, heavy metals, metal removal, acid mine drainage, microbial degradation, mining, treatment, anaerobic treatment, mining wastes, risk assessment, electrokinetics, transport models, acid mine runoff, remediation technologies, fate and transport modeling, biodegradation, groundwater, sediment transport, field monitoring, anaerobic degradation, aquatic ecosystems, contaminated waste sites, runoff, treatment technology

Relevant Websites:

http://www.engr.colostate.edu/hsrc/ Exit

Progress and Final Reports:

Original Abstract

2005 Progress Report

Final

Main Center Abstract and Reports:

R829515    Center for Comprehensive, optimaL, and Effective Abatement of Nutrients

Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R829515C001 Redox Transformations, Complexation and Soil/Sediment Interactions of Inorganic Forms of As and Se in Aquatic Environments: Effects of Natural Organic Matter
R829515C002 Fate and Transport of Metals and Sediment in Surface Water
R829515C003 Metal Removal Capabilities of Passive Bioreactor Systems: Effects of Organic Matter and Microbial Population Dynamics
R829515C004 Evaluating Recovery of Stream Ecosystems from Mining Pollution: Integrating Biochemical, Population, Community and Ecosystem Indicators
R829515C005 Rocky Mountain Regional Hazardous Substance Research Center Training and Technology Transfer Program
R829515C006 Technical Outreach Services for Communities and Technical Assistance to Brownfields
R829515C007 Evaluation of Hydrologic Models for Alternative Covers at Mine Waste Sites
R829515C008 Microbial Reduction of Uranium in Mine Leachate by Fermentative and Iron-Reducing Bacteria
R829515C009 Development and Characterization of Microbial Inocula for High-Performance Passive Treatment of Acid Mine Drainage
R829515C010 Reactive Transport Modeling of Metal Removal From Anaerobic Biozones
R829515C011 Assessment of Electrokinetic Injection of Amendments for Remediation of Acid Mine Drainage
R829515C012 Metal Toxicity Thresholds for Important Reclamation Plant Species of the Rocky Mountains
R829515C013 An Improved Method for Establishing Water Quality Criteria for Mining Impacted Streams