United States
Environmental Protection
Agency
Research and Development (481)
Solid Waste and
Emergency Response (5102G)
EPA542-F-97-012a
November 1997
vvEPA
Lasagna™ Public-Private
Partnership
RTDF
Remediation Technologies
Development Forum
Teams
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What Is the Lasagna™ Public-Private
Partnership?
In early 1994, the U.S. Environmental Protection Agency (EPA) signed a
Cooperative Research and Development Agreement with a private research
consortium—consisting of Monsanto, DuPont, and General Electric—to
jointly develop an integrated, in situ remedial technology, referred to as the
Lasagna™ p'rocess. In 1995, with significant funding from the Department of
Energy (DOE), a field experiment to test the Lasagna™ process was initiated
at the DOE Paducah Gaseous Diffusion Plant in Kentucky. This collaborative
effort between the federal government and industry evolved into one of seven
Action Teams of the Remediation Technologies Development Forum (RTDF).
The RTDF was established in 1992 by EPA to foster collaboration between the
public and private sectors in developing innovative solutions to mutual
hazardous waste problems.
What Is the Problem of Concern?
Contamination in low-permeability or heterogeneous soils poses a significant
technical challenge to in situ remediation efforts. Difficulty in accessing the
contaminants and delivering treatment reagents has rendered traditional tech-
nologies—such as vapor extraction and pump-and-treat—rather ineffective
when applied to the low-permeability soils at many contaminated sites.
Another major problem involves mixed wastes (organics plus heavy
metals/radionuclides). The incompatibility of treatment methods for these two
contrasting types of contaminants has created considerable difficulty in
treating this type of waste.
What Is the Lasagna™ Process?
The Lasagna™ process, so named because of its treatment layers, combines
electrokinetics (EK) with treatment zones that are installed directly in the
contaminated soils to form an integrated in situ remedial process.
Electrokinetics includes electroosmosis (EO, transport of water) and
electromigration (EM, transport of ions). EO, used for years by civil engi-
neers, is known for its effectiveness in moving water uniformly through low-
permeability soils at very low power consumption. Conceptually, the
Lasagna™ process would be used to treat organic and inorganic contaminants
as well as mixed wastes.
The Lasagna™ process is designed to treat soil and ground-water contami-
nants completely in situ, without the use of injection or extraction wells. If
successful, it could replace the more conventional methods for containing and
treating contaminants in low-permeability soils. The schematic diagrams on
the next page depict two typical configurations (horizontal and vertical) of the
Lasagna™ process. Other variations also are possible. Treatment zones can be
discrete or continuous (dispersed in the soil) or a combination of the two.
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Vertical Configuration of the Lasagna™ Process
ground surface
atlon
Degr
ation
Electrode
APPLIED EtECTRICAL POTENTIAL
As the diagrams illustrate, the outer layers consist of positively
or negatively charged electrodes. The electric field created by
the electrodes moves contaminants in soil pore fluids into or
through the treatment layers.
In situ decontamination using the Lasagna™ process can
occur by:
>• Creating zones in close proximity to one another
throughout the contaminated soil region and converting
them into sorpdon/degradation zones by introducing
appropriate materials (e.g., sorbents, catalytic agents,
microbes, oxidants, buffers, etc.). Hydraulic fracturing
and related technologies may provide an effective and
low-cost means for creating such zones horizontally in the
subsurface soil. The degradation zones can also be
emplaced vertically, as depicted in the schematic above,
using sheet piling, trenching, and slurry walls. Methods
such as pneumatic fracturing, jet grouting, and soil mixing
could be used to create dispersed or homogeneous treat-
ment zones.
>• Utilizing electrokinetics to transport contaminants from
the soil into the treatment zones for degradation. Locating
these zones close to one another minimizes the time it
takes for the contaminants to be moved by EK from one
zone to the next. In the horizontal configuration,
hydrofraeturing can be used to place graphite or other
granular, electrically conductive materials in zones above
and below the contaminated soil area to form the elec-
trodes in place. For highly nonpolar contaminants, surfac-
tants can be introduced into the water or incorporated into
the treatment zones to solubilize the organics. For mixed
wastes, treatment zones containing mixed reagents or
multiple zones containing different reagents could be used
to handle organics and metals/radionuclides simultane-
ously or sequentially.
>• Recycling the cathode effluent (high pH) back to the
anode side (low pH), which provides a convenient
means for pH neutralization and water management.
The electrical polarity can be periodically reversed, if
needed, to minimize complications associated with
long-term applications of one-directional EK processes.
Polarity reversal also allows multiple passes of the cont-
aminants through the treatment zones for complete
sorption/degradation.
The orientation of the electrodes and treatment zones
depends on the site/contaminant characteristics. In general,
Horizontal Configuration of the Lasagna™ Process
electrode wells
ground surface
—"^-^C
——-U«I& Granular Electrode
T
—^ y
> Degradation Zone
> Degradation Zone
^> Degradation Zone
Granular Electrode
the vertical configuration is probably applicable to more
shallow contamination (i.e., within 50 feet of the ground
surface), whereas the horizontal configuration, using
hydraulic fracturing or related methods, is capable of
treating much deeper contamination.
What Is the Mission of the
Partnership?
The mission of the Lasagna™ Partnership—which includes
private industry, DOE, and EPA—is to pool expertise and
resources to advance the development of the Lasagna™
process to remediate organic and inorganic contaminants in
low-permeability soils. The overall goal of the Partnership
is to sufficiently develop the Lasagna™ technology so that
it can be utilized for site remediation.
What Has Been Accomplished?
In the Phase I-Vertical field test, completed in 1995 at
Paducah, the Lasagna™ process achieved a 98 percent
removal of TCE, from a tight clay soil (i.e., hydraulic
conductivity <1O7 cm/sec), with some samples showing
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greater than 99 percent removal. TCE soil levels were
reduced from the 100 to 500 ppm range to an average
concentration of 1 ppm. This success led to full-scale testing
of the Lasagna™ process (called Phase HA-Vertical), incor-
porating reactive treatment zones to destroy TCE in situ. The
full-scale test began in August 1996 and covered an area
measuring 30 feet by 21 feet by 45 feet deep. High levels
of TCE in pre-test samples strongly indicated the presence
of pure TCE droplets (Dense Non-Aqueous Phase Liquids
or DNAPLs) in the soil. Two electrodes (one on each end
of the test site) were used, with three treatment zones at
2- and 5-foot intervals to help determine the optimal spacing.
Each electrode or treatment zone measured 21 feet across,
1.5 inches thick, and 45 feet deep.
Despite finding at least 30 times more TCE contamination
than expected and encountering an undefined sand lens (at
a depth of 20 to 25 feet) that may have caused unpre-
dictable hydraulic movement at the test site, the test was
successful. Samples taken after about 10 months of opera-
tion showed 99.8 percent TCE removal in the soil region
bracketed between the 2-foot-spacing treatment zones.
This corresponded to an average TCE level of 0.1 ppm,
substantially lower than the Kentucky soil cleanup target.
Two soil sections downstream of the last treatment zone
showed about 70 percent TCE removal, clearly suggesting
that cleanup was achieved. Well water samples and
analysis of reaction products also suggested DNAPL
movement and its in situ degradation by iron filings. Based
on the test data, DuPont has determined that the cost of the
Lasagna™ treatment is $50 to $100/yd3 for cleanup of a 1-
acre or larger site. As a result of this demonstration, DOE
is pursuing regulatory approval through the CERCLA
process to clean up the entire Solid Waste Management
Unit using Lasagna™.
The University of Cincinnati, through a Cooperative
Agreement funded by EPA, is conducting laboratory and
field research on hydrofracturing and biodegradation to
develop the horizontal configuration. This work, which has
been performed in clean soils, has focused on developing
durable electrical and fluid connections to the horizontal
(hydraulic fracture) electrodes and treatment zones and
solving the problem of gas generation in the electrodes. Six
different horizontal test units have been installed at a clean
site near Cincinnati. The survival of a methanotropic
microorganism in a treatment zone is being examined
while the electrodes above and below are energized to
move water by electroosmotic processes. The treatment
zone is composed of granular activated carbon, which was
seeded with microorganisms and nutrients through
hydrofracturing before it was installed. The microorganism
was isolated from a group of organisms and was selected
for its ability to degrade TCE. Two small-scale horizontal
cells have been installed in TCE-contaminated soil
at Rickenbacker Air National Guard Base (ANGB) in
Columbus, Ohio. The treatment zones in one cell use
reductive dechlorination (zero-valent iron); the other
cell has a single biological treatment zone. A
30 percent reduction in TCE concentrations has been
observed in soils in the biological treatment cell. Both
cells are in operation and are being sampled periodically
to track TCE concentrations and determine when treat-
ment can be terminated. The infrastructure for two large-
scale horizontal cells has been installed in TCE-contami-
nated soil at Offutt Air Force Base (AFB) in Omaha,
Nebraska. The computer-controlled power supply, instru-
ment building, and utilities are in place, and the materials
to install the graphite electrodes and zero-valent iron treat-
ment zones have been ordered.
Lasagna™ Partnership Members
DuPont (Anaerobic Blodogradatlon/
Vertical Zone Installation)
DOE (Site Selection/
and Field Support)
I'
General Electric |^
(ElectroMnvtlc/PhysIcochemtcal
TVeatment)
4 EPA (Hydrofracture/
Blodogrftdatlon)
Integrated In-Situ
Remediation Technology
Monsanto (La«agna™ /
ElBctrootmosls/Blodogradatlon)
What Are the Partners9 Roles?
Each Partner brings particular knowledge and expertise, as
well as contributes the resources necessary to complete the
Partnership's research and development mission. The three
companies share proprietary technologies and their collec-
tive understanding of EK, catalytic dechlorination, biore-
mediation, process simulation, and cost analysis to support
development and evaluation of the Lasagna™ process.
DOE brings to the project knowledge of EK and bioreme-
diation and provides funding and analytical and field
support for the studies at Paducah. EPA's National Risk
Management Research Laboratory (NRMRL) in
Cincinnati is leading the investigation of emplacement and
operation of the horizontal configuration of the Lasagna™
process. In conjunction with the University of Cincinnati,
NRMRL is using hydrofracturing to create electrodes and
treatment zones in subsurface soils and is selecting
microorganisms that can degrade contaminants and survive
electroosmosis. NRMRL and the University of Cincinnati
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also are investigating the basic geochemistry of the Lasagna™ process to
provide a sound basis for optimization. The Partnership is facilitated by Clean
Sites, Inc., under a cooperative agreement with EPA's Technology Innovation
Office, and by The Scientific Consulting Group.
What Activities Are Planned?
In the spring of 1996, the Partnership's Phase HA-Vertical Lasagna™
demonstration was selected for inclusion in the federal government's Rapid
Commercialization Initiative (RCI). Participation of California EPA,
Southeastern States Energy Board, the Western Governors Association, and
various state environmental agencies in RCI will help facilitate regulatory
acceptance and widespread use of the Lasagna™ technology. Results from
Phase IIA-Vertical and the subsequent cleanup (Phase IIB-Vertical) will be
used to produce verified cost and performance data for the Lasagna™
process, which will also greatly increase its acceptance and use. Various
treatment processes are currently being investigated in the laboratory to
address other types of contaminants, such as DNAPLs, heavy metals, and
mixed wastes. Additional test sites are being sought to further demonstrate
the effectiveness of the technology. Monsanto also is actively working on the
commercialization of the Lasagna™ technology through licensing and part-
nership agreements.
The work on gas generation and electrical/fluid
connections for horizontal emplacements in clean soil
was completed during the spring and summer of
1996. The horizontal field test at Rickenbacker
ANGB will continue in 1997-1998 until treatment is
completed. The horizontal test cells are scheduled for installation at Offutt
AFB in the fall of 1997 and will operate during 1997-1998.
Who Are the Members of the
Lasagna™ Partnership?
DuPont
General Electric
Monsanto
U.S. Department of Energy
U.S. Environmental Protection Agency
Additional organizations involved in the projects include Lockheed Martin
Energy Systems, Nilex, API, CDM Federal, the University of Cincinnati, the
State of Kentucky, and the U.S. Air Force.
RTDF
Remediation Technologies
Development Forum
Lusagna is a trademark of the Monsanto Company.
Would You Like
More Information?
For more information on the vertical config-
uration of the Lasagna™ Process, please
contact:
Sa V. Ho, Ph.D. (Principal Investigator)
B. Mason Hughes, Ph.D. (Project Manager)
Monsanto Company
800 N. Lindbergh Boulevard
St. Louis, MO 63167
Tel: 314-694-5179 or 314-694-1466
E-mail: sa.v.ho@monsanto.com or
b.mason.hughes @ monsanto.com
For more information on the
horizontal configuration of the Lasagna™
Process, please contact:
Michael Roulier, Ph.D.
U.S. Environmental Protection Agency
26 West Martin Luther King Drive
Cincinnati, OH 45268
Tel: 513-569-7796
E-Mail: roulier.michael @ epamail.epa.gov
For information on the RTDF or other
Action Teams, please visit the RTDF World
Wide Web site at www.rtdf.org or contact:
Robert Olexsey
U.S. Environmental Protection Agency
26 West Martin Luther King Drive
Cincinnati, OH 45268
Tel: 513-569-7861
E-mail: olexsey.bob@epamail.epa.gov
Walter W. Kovalick, Jr., Ph.D.
U.S. Environmental Protection Agency
401 M Street, SW (5102G)
Washington, DC 20460
Tel: 703-603-9910
E-mail: kovalick.walter@epamail.epa.gov
To request other RTDF fact sheets, please
write/fax to:
EPA/NCEPI
11305 Reed Hartman Highway, Suite 219
Cincinnati, OH 45241
Fax: 513-489-8695
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