SEPA NRMRL
www.epa.gov/nrmrl
NATIONAL RISK MANAGEMENT RESEARCH LABORATORY
GROUND WATER AND ECOSYSTEMS RESTORATION RESEARCH
Treatment of Source Zone Chlorinated Solvents Using
Emulsfied Zero-Valent Iron Nanoparticles
Background
Source zone dense nonaqueous-phase liquid (DNAPL) serves as a
persistent source of dissolved contamination and is a major impediment
to cost-effective remediation and attainment of site closure. Effective
treatment technologies are needed to remediate the source zones. One
such technology is the use of emulsified zero-valent iron (EZVI), a
surfactant-stabilized, biodegradable emulsion that forms emulsion
droplets consisting of an oil-liquid membrane surrounding zero-valent
iron particles in water. Increased destruction of chlorinated solvents
may be achieved using EZVI through increased contact between the
DNAPL and the nanosized iron, and by providing vegetable oil to
augment biological degradation.
This project is a pilot field study that focuses on treatment of source
zone chlorinated solvents (perchloroethylene and its degradation
products) using EZVI nanoparticles at the Parris Island Marine Corps
Recruit Depot, South Carolina. The joint project is an Environmental
Security Technology Certification Program demonstration. The project
is also a pilot program project under EPA's Office of Solid Waste and
Emergency Response, and a project under Remediation Technologies
Development Forum Permeable Reactive Barrier.
Objectives
•	Evaluate the ability of two injection technologies (pneumatic
and direct push) to evenly distribute the EZVI in the subsurface
•	Evaluate dechlorination pathways (biotic versus abiotic)
•	Identify and evaluate the mechanisms of formation of corrosion
products of injected EZVI
•	Evaluate the long-term performance of EZVI to decrease the
DNAPL mass
Approaches
There are both field and laboratory components in this research. Field
sampling and analysis are coupled with laboratory instrumentation and
detailed analysis using a variety of techniques for wet-chemical and
solid-phase characterization. Compound-specific stable carbon (! C) and overall volatile organic chlorine C CI)
isotopes analysis will be performed on field-collected samples. The results will be compared before and after EZVI
injection at the Parris Island site. Although both abiotic and biotic dechlorination reactions will result in enrichment
•	*	13	12	*	* *	37	35 *	*	*
of the heavier carbon isotope ( T over ~C) and heavier chlorine isotope C CI over CI) in the residual fraction of
The National Risk Management Research Laboratory's mission is to advance scientific and engineering
solutions that enable EPA and others to effectively manage current and future environmental risks.
NRMRL possesses unique strengths and capabilities and is dedicated to providing credible
technological information and scientific solutions that support national priorities
and protect human health and the environment.

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chlorinated solvents, there may be significant differences in the degree of the enrichment. These differences may be
sufficiently large to be used to separate the biotic and abiotc degradation pathways. Identification of iron corrosion
products will be performed and several analytical tools (XRD, SEM, FTIR, AFM, ICP-OES) will be used for this
purpose. Well waters at the Parris Island site will be monitored for at least two years after EZVI injection.
Accomplishments to Date (June 2007)
Injection of EZVI was conducted in October 2006. Soil cores were
taken immediately to evaluate the distribution of EZVI. Baseline
characterization of ground water and sediments was undertaken before
injection. Post-injection monitoring of ground water was performed in
November and December 2006; January, March, and July 2007; January
and July 2008; and March 2009. Data summary and interpretation are
being conducted with respect to the changes in geochemistry of ground
water and characterization of solid phases. A potential long-term
outcome from this research would be development of novel approaches
for site remediation and characterization of the extent and conditions
under which nanoparticles may be transported in ground water. The
results would enhance E PA' s capability to meet new challenges of environmental significance
Investigators
Robert W. Puis
U.S. EPA
Ground Water and Ecosystem Restoration Division
Ada, Oklahoma 74820
580-436-8543
Chunming Su
U.S. EPA
Ground Water and Ecosystem Restoration Division
Ada, Oklahoma 74820
580-436-8638
Collaborators
GeoSyntec Consultants
NASA
U.S. Navy
The National Risk Management Research Laboratory's mission is to advance scientific and engineering
solutions that enable EPA and others to effectively manage current and future environmental risks.
NRMRL possesses unique strengths and capabilities and is dedicated to providing credible
technological information and scientific solutions that support national priorities
and protect human health and the environment.

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