United States
Environmental Protection
Agency
Office of Research and Development (481)
Office of Solid Waste and
Emergency Response (5102G)
EPA542-F-96-010A
September 1996
&EPA
TM
Lasagna1"" Public-Private
Partnership
RTDF
Remediation Technologies
Development Forum
Action
Teams
Lasagna Partnership
Bioremediation Consortium
Permeable Barriers Action
Team
DIVERT Soil-Metals Action
Team
Sediments Remediation
Action Team
What is the Lasagna™ Public-Private
Partnership?
In early 1994, the U.S. Environmental Protection Agency (EPA) signed a
Cooperative Research and Development Agreement (CRADA) with a pri-
vate Research Consortium—consisting of Monsanto, DuPont, and General
Electric—to jointly develop an integrated, in-situ remedial technology
referred to as the Lasagna™ process. In 1995, with significant funding from
the Department of Energy (DOE), a field experiment was initiated at the
DOE Paducah Gaseous Diffusion Plant (PGDP) in Kentucky, to test the
Lasagna™ process. This collaborative effort between the federal
government and industry evolved as a separate Action Team of the
Remediation Technologies Development Forum (RTDF). The RTDF was
established in 1992 by EPA after industry representatives met with the
Administrator to identify ways of working together to solve complex
hazardous waste site contamination problems.
What is the Problem of Concern ?
Contamination in low permeability soils poses a significant technical
challenge to in-situ remediation efforts. Accessibility of the contaminants
and delivery of treatment reagents have posed problems, rendering
traditional technologies, such as vapor extraction and pump-and-treat,
rather ineffective when applied to low permeability soils present at many
contaminated sites.
What is the Lasagna™ Process?
The Lasagna™ process, so named because of its treatment layers, combines
electroosmosis with treatment zones that are installed directly in the con-
taminated soils to form an integrated in-situ remedial process.
Electroosmosis, used for years by civil engineers, is well 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 groundwater 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 both the horizontal and vertical configura-
tions of the Lasagna™ process.
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Vertical Configuration of the Lasagna Process
Electrode
APPLIED ELECTRICAL POTENTIAL
Note: Electroosmotic now is reversed upon switching electrical polarity.
As illustrated in the diagrams, the outer layers consist of
either positively or negatively charged electrodes. The
electric field created by the electrodes moves contami-
nants in soil pore fluids into or through the treatment
layers.
Jn-Situ decontamination using the Lasagna
occur by:
process can
f Creating zones in close proximity to one another
throughout the contaminated soil region, and convert-
ing them into sorption/degradation zones by introduc-
ing 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. In the vertical configuration, sheet
piling, trenching, and slurry walls can be used to
create the treatment zones.
"f Utilizing electroosmosis as a liquid pump for
flushing contaminants from the soil into the treatment
zones for degradation. Locating these zones close to
one another minimizes the time it takes for the liquid
to be moved by electroosmosis from one zone to the
next. In the horizontal configuration, hydrofracturing
is used to place graphite or other granular, electrically
conductive materials in zones above and below the
contaminated soil area to form the electrodes in place.
For highly non-polar contaminants, surfactants can be
introduced into the water or incorporated into the
treatment zones to solubilize the organics.
'f Reversing liquid flow by switching the electrical
polarity may increase the efficiency of contaminant
removal from the soil, as well as allow multiple passes
of the contaminants through the treatment zones for
complete sorption/degradation. Polarity reversal also
minimizes complications associated with long-term
applications of one-directional electroosmotic proc-
esses. Optionally, the cathode effluent (high pH) can be
recycled back to the anode side (low pH), which
provides a convenient means for pH neutralization and
water management.
The orientation of the electrodes and the treatment zones
depends on the site/contaminant characteristics. In general,
the vertical configuration is probably applicable to more
shallow contamination (i.e., within 50 feet of the ground
Horizontal Configuration of the Lasagna Process
contaminated
soil
Degradation
Zone
Granular
Electrode
Note: Electroosmotic flow Is reversed upon switching electrical polarity.
surface), whereas the horizontal configuration, using
hydraulic fracturing or related methods, is uniquely capable
of treating much deeper contam ination.
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
dense soils. The overall goal of the Partnership is to
sufficiently develop the Lasagna™ technology so that it can
be utilized for site remediation. The initial focus of the
study was development of the vertical process for remedia-
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tion of chlorinated solvents. The Partnership members
collectively performed research to integrate a viable
treatment process via a combination of electrokinetics and
treatment zones; destruction via bioremediation, catalysis,
or other technique; and adsorption. Laboratory and field
tests, process simulation, and cost analyses were performed
and modifications were made, which ultimately led to the
field demonstration of the vertical configuration of the
Lasagna™ process (Phase I-Vertical test) at Paducah, KY.
What Has Been Accomplished?
The Phase I-Vertical field test, which operated for 120 days
at the DOE PGDP, was completed in May 1995. One of the
key objectives of this study was to successfully demonstrate
the coupling of electroosmotic flushing of trichloroethylene
(TCE) from the clay soil with its removal from the pore
water by in-situ adsorption. The test site measured 15 feet
wide by 10 feet across and 15 feet deep. Steel panels were
used as electrodes and the treatment zones consisted of
wickdrains containing granular activated carbon. In Phase
I-Vertical, carbon was used in the treatment zones to
perform mass-balance calculations. Sampling and analysis
of the carbon at the end of the study accounted for a substan-
tial amount of the TCE. Monitoring TCE levels in the air
during the test showed that only 4% of the total TCE was lost
through evaporation. Scale-up from laboratory units was
successfully achieved with respect to electrical parameters
and electroosmotic flow. Soil samples taken throughout the
test site before and after the test indicate a 98% removal of
TCE from a tight clay soil (i.e., hydraulic conductivity <10'
cm/sec), with some samples showing greater than 99%
removal. TCE soil levels were reduced from the 100 to
500 ppm range to an average concentration of 1 ppm.
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; they are
currently examining the survival of a methanotropic
microorganism in a treatment zone while the electrodes
above and below are energized to move water by electroos-
motic processes. The treatment zone is composed of
granular activated carbon, which was seeded with microor-
ganisms and nutrients before it was installed via hydrofrac-
turing. The microorganism was isolated from a group of
organisms and was selected for its ability to degrade TCE.
Preliminary tests have been conducted at sites in Ohio and
Nebraska to determine their suitability for a field test of the
horizontal Lasagna™ configuration.
What Are the Partners' 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 electrokinetics, catalytic dechlorina-
tion, bioremediation, process simulation, and cost analysis
to support development and evaluation of the Lasagna™
process. DOE brings to the project knowledge of electroki-
netics and bioremediation and provides funding and
analytical and field support for the studies at the PGDP.
EPA's National Risk Management Research Laboratory
(EPA/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, EPA/NRMRL is using hydrofrac-
turing to create electrodes and treatment zones in subsurface
soils and is selecting microorganisms that can degrade
contaminants and survive electroosmosis. EPA/NRMRL is
also investigating the basic geochemistry of the Lasagna™
process to provide a sound basis for optimization. The
Partnership is facilitated by Clean Sites under a cooperative
agreement with EPA's Technology Innovation Office and by
The Scientific Consulting Group under a contract with
EPA's Office of Research and Development.
What Activities Are Planned?
The success of the Phase I-Vertical field experiment has led
to plans for conducting additional field studies incorporat-
ing reactive treatment zones, such as iron filings, to destroy
TCE in situ. The Phase II-Vertical field experiment, which
Lasagna'M Partnership Members
DuPont (Anaerobic Bioredegradation/
Vertical Zone Installation)
DOE (Site Selection
and Field Support)
EPA (Hydrofracture/
Biodegradation)
I
Integrated In-Situ
Remediation Technology
General Electric
(EK and Physicochemical
Treatment)
Monsanto (Lasagna"/
Elect roosmosis/Biodegradation)
April 19%
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stage (Phase Ha- Vertical), the Lasagna™ process will be used to treat approxi-
mately 20 times more soil than was treated in Phase I-Vertical. This study will
help resolve any scale-up questions, substantiate technology cost estimates,
and evaluate the performance of zero-valent iron in the treatment zones. If the
test is successful, the PGDP Environmental Restoration Program is planning
to use the technology to remediate the entire Solid Waste Management Unit.
Direct treatment costs for a typical one-acre site are estimated at $50/yd3 of soil
and the remediation could occur over a period of 3 years. In the spring of 1 996,
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 the
widespread use of the
LasagnaT* technology.
Results from Phase Ila-
Vertical and Phase lib-
Vertical field studies 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 contam inants, such as DN APLs, heavy metals, and m ixed wastes.
The work on gas generation and electrical/fluid connections for horizontal
emplacements in clean soil was completed during the summer of 1 996. Phase
I-Horizontal field tests in TCE-contaminated soils will be conducted in the fall
of 1996 at sites in Ohio and Nebraska, where preliminary testing has already
been conducted.
Who are the Members of the Lasagna7
Partnership?
DuPont
General Electric
Monsanto
To request other RTDF factsheets, please
write/fax to:
EPA/NCEPI
11305 Reed Hartman Highway, Suite 219
Cincinnati, OH 45241
Fax: (513)489-8695
U.S. Environmental
Protection Agency
U.S. Department of Energy
Additional organizations
involved in the projects include
Lockheed Martin Energy
Systems, Nilex, API, COM
Federal, University of Cincin-
nati, the State of Kentucky, and
the U.S. Air Force.
KIDF
Remediation Technologies
Development Forum
Would You
Like
More Information?
For more information on the Lasagna™
Partnership, please contact:
Michael Roulier, Ph.D.
I :.S. Environmental Protection Agency
26 West Martin Luther King Drive
Cincinnati. Oil 45268
Tel: (513)569-7796
Email: roulier.michael@epamaiLepa.gov
Phil Brodsky, PhJ>.
Monsanto Company
800 N. Lindbergh Boulevard
St. Louis, MO 63167
Teb (314) 694-3235
Email: phbrod@ccmaiLmonsanto.coin
For information on the RTDF or the
other Action Teams, please contact:
Robert Olexsey
I -S. Environmental Protection Agency
Tel: (513)569-7861
Email: olexsey.bob@epaiiiail.eDa.gov
Walter Kowdick, Jr., Ph.D.
I -S. Environmental Protection Agency
Tel: (703) 605-9910
Email: kovalick.vralter@enamail.epa.gov
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