Grantee Research Project Results

Treatment of Perchlorate Contaminated Water Using a Combined Biotic/Abiotic Process

EPA Grant Number: R831276C010
Subproject: this is subproject number 010 , established and managed by the Center Director under grant CR831276
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: UT Center for Infrastructure Modeling and Management
Center Director: Hodges, Ben R.
Title: Treatment of Perchlorate Contaminated Water Using a Combined Biotic/Abiotic Process
Investigators: Katz, Lynn , Speitel, Gerald E.
Institution: The University of Texas at Austin
EPA Project Officer: Aja, Hayley
Project Period: December 1, 2003 through November 30, 2004
Project Amount: Refer to main center abstract for funding details.
RFA: Gulf Coast Hazardous Substance Research Center (Lamar University) (1996) RFA Text |  Recipients Lists
Research Category: Hazardous Waste/Remediation , Targeted Research

Objective:

Perchlorate, a water contaminant that interferes with the thyroid's ability to use iodine to produce growth hormones, has been found in groundwater in a number of states including Texas and Alabama. While perchlorate is not regulated by the U.S. Environmental Protection Agency at this time, it is listed as one of the contaminants on the EPA Contaminant Candidate List (CCL) because of potential health concerns. In addition, the state of Texas has adopted a four part per billion interim action level for remediation of perchlorate in drinking water based on the limited toxicological data available.

Very few research studies have addressed treatment alternatives for perchlorate, especially for treatment of waters that contain only the part per billion levels of contamination recently identified in groundwaters. A recent literature review suggests that anaerobic biodegradation is one of the most promising treatment technologies available. Indeed, a number of bacteria that are capable of using nitrate as an electron acceptor are also capable of using perchlorate. In addition, chemical treatment techniques such as chemical reduction appear to be favorable based on equilibrium calculations; however, perchlorate removal using this process has not been effective due to extremely slow rates of reaction.

The proposed research will evaluate one potential treatment/remediation scheme that involves a combined biotic/abiotic process using zero valent iron (iron filings) and anaerobic bacteria. Literature reports indicate that this type of combined process has potential for reducing nitrate, and the proposed research is based on the hypothesis that a similar process will work for perchlorate remediation. Preliminary research in our laboratory using the combined system for perchlorate remediation supports this hypothesis, but also highlights the need for further research. Several research issues must be addressed to develop this technology: 1) microbial kinetics, 2) water and soil chemistry characteristics as they affect both the ability to control pH and minimize passivation of the iron surface, and 3) process design and operating considerations in meeting the desired treatment goals (i.e., usually < 4 µg/L).

Approach:

The research will be conducted in three phases. Phase I will provide an improved understanding of the biodegradation process by extending our preliminary work to determine the kinetics of biodegradation at lower perchlorate concentrations and in the presence of varying nitrate concentrations. Phase II will focus on the chemistry aspects of the process, studying the impact of water and soil chemistry characteristics on pH stability and iron passivation. Research in Phases I and II will employ batch reactors. In Phase III, we will demonstrate performance of the combined Fe(0)/biological process in continuous-flow, laboratory-scale column experiments, based on the information developed in Phases I and II. Several columns will be run in parallel to compare the performance under different conditions of water and soil chemistry. The columns will be packed with either Fe(0) or mixtures of Fe(0) and subsurface soil. In all phases, perchlorate and its degradation products, hydrogen, nitrate, pH, and iron will be measured using standard analytical methods.

Expected Results:

The results from the project will allow us to evaluate both in-situ remediation and ex-situ treatment of perchlorate contaminated waters. A project duration of three years is proposed with a first-year budget of $69,442; a budget of approximately $70,000 per year is proposed for the subsequent two years.

Publications and Presentations:

Publications have been submitted on this subproject: View all 1 publications for this subproject | View all 64 publications for this center

Supplemental Keywords:

RFA, Scientific Discipline, Water, Waste, Hazardous, Remediation, Environmental Chemistry, Hazardous Waste, Drinking Water, Environmental Engineering, hazardous waste storage, contaminated sediments, hazardous waste treatment, hazardous wate, contaminant candidate list, contaminated groundwater, contaminated soil, groundwater remediation, contaminant removal, groundwater, drinking water contaminants, drinking water treatment, zero valent iron, anaerobic biodegradation, perchlorate

Progress and Final Reports:

Final

Main Center Abstract and Reports:

CR831276    UT Center for Infrastructure Modeling and Management

Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R831276C001 DNAPL Source Control by Reductive Dechlorination with Fe(II)
R831276C002 Arsenic Removal and Stabilization with Synthesized Pyrite
R831276C003 A Large-Scale Experimental Investigation of the Impact of Ethanol on Groundwater Contamination
R831276C004 Visible-Light-Responsive Titania Modified with Aerogel/Ferroelectric Optical Materials for VOC Oxidation
R831276C005 Development of a Microwave-Induced On-Site Regeneration Technology for Advancing the Control of Mercury and VOC Emissions Employing Activated Carbon
R831276C006 Pollution Prevention through Functionality Tracking and Property Integration
R831276C007 Compact Nephelometer System for On-Line Monitoring of Particulate Matter Emissions
R831276C008 Effect of Pitting Corrosion Promoters on the Treatment of Waters Contaminated with a Nitroaromatic Compounds Using Integrated Reductive/Oxidative Processes
R831276C009 Linear Polymer Chain and Bioengineered Chelators for Metals Remediation
R831276C010 Treatment of Perchlorate Contaminated Water Using a Combined Biotic/Abiotic Process
R831276C011 Rapid Determination of Microbial Pathways for Pollutant Degradation
R831276C012 Simulations of the Emission, Transport, Chemistry and Deposition of Atmospheric Mercury in the Upper Gulf Coast Region
R831276C013 Reduction of Environmental Impact and Improvement of Intrinsic Security in Unsteady-state
R831276C014 Integrated Chemical Complex and Cogeneration Analysis System: Greenhouse Gas Management and Pollution Prevention Solutions
R831276C015 Improved Combustion Catalysts for NOx Emission Reduction
R831276C016 A Large-Scale Experimental Investigation of the Impact of Ethanol on Groundwater Contamination
R831276C017 Minimization of Hazardous Ion-Exchange Brine Waste by Biological Treatment of Perchlorate and Nitrate to Allow Brine Recycle
R831276C018 Integrated Chemical Complex and Cogeneration Analysis System: Greenhouse Gas Management and Pollution Prevention Solutions