United States
Environmental Protection
Agency
Solid Waste
Emergency Response
(5102W)
EPA 542-N-94-004
May 1994
The Applied Technologies Journal for Superfund Removals & Remedial Actions & RCRA Corrective Actions
CANADIAN BIO-REACTOR ADVANCES
KNOWLEDGE OF HYDROCARBON
REMEDIATION
By Alex Lye, Environment Canada, Groundwater and Soil Remediation
Program, and Lin Callow, Canadian Association of Petroleum Producers
The Bio-Reactor Project tests the
premise that hydrocarbon contaminated
soils and soil-like wastes with high levels
of salts can be treated effectively and
efficiently by combining leaching with
soil biological processes. To date, two
types of wastes have been tested in the
Bio-Reactor agricultural topsoil
PICKING
PARTNERS
The emphasis of this issue of TECH
TRENDS is on public-private
partnerships that foster innovative
technology. In addition to the Bio-
Reactor Project article on this page,
don t miss the article on EPA s
Public-Private Partnership to Evaluate
Innovative Technologies, on page 3.
contaminated with crude oil and brine
from a pipeline break (Waste 1) and
saline diesel invert mud drill cuttings
(hereinafter DIMR ) from a drilling site.
Results from the first two years
laboratory and field operations have
demonstrated that the Bio-Reactor
concept is viable. The project is co-
funded by the Canadian Association of
Petroleum Producers (CAPP); by
Environment Canada through its
contributions to the Development and
Demonstration of Site Remediation
Technology Program (DESRT),
Groundwater and Soil Remediation
Program (GASReP) and Federal Program
on Energy Research and Development
(PERD); and by the Alberta Environ-
mental Research Trust. The research is
conducted by the Alberta Environmental
BIO-REACTOR CELL
LEACHATE COLLECTION
Schematic cross section of a Bio-Reactor Cell
Soil-like
Waste J
Centre in Vegreville and the University
of Calgary. The Bio-Reactor is located
at the Morrison Petroleums, Ltd. Nevis
Sour Gas Plant.
In contrast to landfarming of oily
wastes, the Bio-Reactor exerts strict
controls on all inputs, the physical-
chemical environment and the fate of the
transformed waste products. The Bio-
Reactor can take wastes highly contamin-
ated with oily wastes, that are not soil in
the context of genesis, composition and
function, and process them into stable soil-
like solids with characteristics conducive to
bioremediation and leaching. The wastes
are thus processed in a soil-like environ-
ment with enhanced soil fertility, soil
structure, soil chemistry and activity of
soil organisms. Salts are removed by
leaching prior to hydrocarbon reduction.
The Nevis sour gas plant provides
essential services, such as heat, electricity,
water and non treatable liquid waste
disposal. In addition to using existing
mixing equipment, a novel materials
aggregator was developed. The Bio-
Reactor was constructed consisting of nine
cells in a linear array, each 3x10 meters
(m), with independent controls for the
following features: leachate containment
and disposal (deep well injection);
irrigation system to provide water, leach
out salts and add soluble fertilizers;
utilization of gas plant waste heat; forced
Bio-Reactor continued on page 2
Recycled/Recyclable
Printed with Soy/Canola Ink on paper that
contains at least 50% recycled fiber
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SITE
s
FLUID EXTRACTION-BIOLOGICAL
DEGRADATION OF ORGAIMICS
By Annette Gatchett, Risk Reduction Engineering Laboratory
E'PA's Emerging Technology SITE
(Superfund Innovative Technology
Evaluation) Program has evaluated a
pilot-scale fluid extraction-biological
degradation (FEED) process that
remediates organic contaminants in soil.
The system, developed by the Institute of
Gas Technology, combines three distinct
technologies: (1) fluid extraction, which
removes the organics from contaminated
solids: (2) separation, which transfers the
pollutants from the extract to a
biologically compatible solvent; and
(3) biological treatment, which degrades
the pollutants to innocuous end-
products. The evaluation results show
that the FEED process was able to
effectively extract 206 ring polycyclic
aromatic hydrocarbons (PAH) at low
temperatures and moderate pressures.
Total contaminant concentrations in
three different soil tests were 1925
micrograms per gram of soil for soil 1,
1504 micrograms per gram for soil 2 and
1969 micrograms per gram for soil 3.
Soil 1, from a wood treatment site in
Texas, was sandy with a 14% clay
content. Soils 2 and 3, from two
different gas sites, were almost entirely
sand. The effectiveness of the extraction
process was determined by following the
fate of 16 compounds; and, examples of
removal rates for extraction and
biological treatment are given below.
In the fluid extraction step, excavated
soils were placed in a pressure vessel and
extracted with a recirculated stream of
supercritical or near-supercritical carbon
dioxide (CO2). An extraction co-solvent
increased removal of the contaminants.
Extraction tests were performed in a
supercritical fluid extraction unit. Soil 1
tests varied temperature, pressure, CO2 to
contaminant ratio and the addition of
5% methanol co- solvent. Temperatures
were not varied in the extraction tests for
soils 2 and 3. Clay in soil 1 did not
appear to interfere with the extraction of
the PAH contaminants. Increases in
pressure and CO2 and the addition of 5%
methanol co-solvent increased extraction
levels. The average 2 ring PAH
extraction removal rates were 98.7% for
soil 1, 50% for soil 2 and 99.4% for soil
3. The average 3 ring PAH extraction
removal rates were 97.7% for soil 1,
89.5% for soil 2 and 99% for soil 3. The
average 4 ring PAH extraction removal
rates were 87.7% in soil 1, 82.2% in soil
2 and 97.9% in soil 3.
Following extraction, organic contaminants
were transferred to a biologically-compatible
separation solvent such as water or a water/
methanol mixture. The separation solvent was
sent to the final stage of the process, where
bacteria degraded the waste to C02 and water.
Biodegradation of the extracts ranged from
92% to 96%. Clean extraction solvent was
recycled to the extraction stage.
Biodegradation occurred in above-
ground aerobic bioreactors, using
mixtures of bacterial cultures capable of
degrading the contaminants. Selection of
cultures was based on site characteristics.
For example, for a site contaminated
mainly with PAHs, such as the soils for
this evaluation, cultures able to
metabolize or cometabolize these hydro-
carbons would be used. In this SITE
evaluation, the microbial consortium
effectively metabolized and transformed
the PAHs in batch-fed and continuous
feed reactors. Growth or metabolic
activities of the microbial consortium
were not inhibited by methanol extract.
For more information, contact Annette
Gatchett of EPA s Risk Reduction
Engineering Laboratory at 513-569-
7697. Also, a summary report of the
evaluation will be available by Fall 1994.
PAHs
Extraction &
Bio-Reaction
Bio-Reactor continued from page 1
subsurface aeration; tillage via a rail-
mounted rototiller; and instrumentation
to monitor moisture and temperature,
and provisions to sample for oxygen, salts,
oil content, carbon dioxide, volatile
hydrocarbons and soil characteristics.
Waste 1, the crude oil spill in
agricultural topsoil, arrived at the Bio-
Reactor in a state totally unsuitable for
leaching and bioremediation; it was a
wet, oily, structureless mass of soil clods.
To distribute the oil throughout the 40
tons of material, the waste was mixed by
a hydraulicalry driven rototiller.
However, the waste still lacked crucial
features of arable soil structure and
stability. Without structure, it could
not be easily handled or leached, nor
would it support biological activity.
The aggregation problem was solved
with the development of a specially
designed aggregator; and, the aggregated
material with N and P fertilizer was
loaded into the Bio-Reactor to a depth
of 15 centimeters (cm). The irrigation
system was then used to rapidly leach
out the salts (mainly NaCl); and, the
degradation of the hydrocarbons was
initiated by the native microflora.
During the residence time in the Bio-
Reactor, the oil content decreased
substantially: and, the use of waste heat
increased the losses of oil. However, oil
losses were unaffected by forced
aeration, likely because of good
aggregation and a shallow treatment
depth.
After 11 months in the Bio-Reactor,
Waste 1 was transferred to a specially
designed secondary treatment unit, the
Bio-Pile. It is a simplified design
Bio-Reactor continued on page 4
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Partners
PUBLIC-PRIVATE PARTNERSHIP TO
EVALUATE TECHNOLOGIES
By Daniel Powell, EPA Technology Innovation Office
The U.S. Environmental Protection
Agency (EPA), state environmental
departments and other Federal
departments are joining in partnerships
with Fortune 500 companies to develop
innovative treatment systems to address
contamination problems of mutual
concern. The goal of this public-private
partnership concept is to obtain market,
regulatory and public acceptance of
innovative technologies through full-scale
demonstrations of innovative hazardous
waste treatment systems and treatment
trains at Federal facility sites. The
partnership will actively promote the use
of less costly, environmentally sound
technologies.
The public and private partners realize
that there are benefits to pooling the
expertise and initiative of EPA
laboratories and State programs, other
Federal research centers and private
industries engineering departments. The
effort can lead to faster identification and
implementation of cost-effective,
permanent treatment technologies and
can encourage community acceptance of
innovative alternatives to incineration
through education.
The partnership is managed by EPA s
Technology Innovation Office (TIO)
and, through a cooperative agreement, is
facilitated by Clean Sites, Inc. It brings
together Fortune 500 firms, who are
potentially responsible parties (PRPs) or
operators of numerous Superfund and
Resource Conservation and Recovery Act
(RCRA) sites; Federal facility technology
users: and regulators (EPA and States).
The partners participate in technology
selection, demonstration design and
documentation of results. By including
all of these parties from the earliest stages,
full-scale cost and performance
information on demonstrated tech-
nologies can be more easily transferred by
both Federal and private parties to other
sites.
The first partnership effort is now in
the advanced planning stage at the
McClellan Air Force Base site in
Sacramento, California. The demon-
strations at McClellan represent the pilot
application of the public-private
partnership concept. Partners at
McClellan are EPA s Office of Solid
Waste and Emergency Response,
Office of Research and Development
Risk Reduction Engineering Laboratory
and Region 9; the State of California; the
Air Force (Headquarters and McClellan
Air Force Base): and seven private
companies (Dow, DuPont, Monsanto,
Xerox, AT&T, Beazer East and Southern
California Edison).
Presently, the partnership is in the
process of designing test plans for two
demonstrations - a two-phase vacuum
extraction system for treating organic
contamination in the saturated zone and
a photolytic destruction unit to treat off-
gases from a soil vapor extraction system.
The demonstrations should commence in
August, with an opening ceremony to be
held shortly thereafter.
In addition to two-phase vacuum
extraction, the partnership may consider
other ground water technologies for
evaluation, including cometabolic
biotreatment and high-energy electron
irradiation. To address the off-gas that
results from soil vapor extraction
operations, three technologies in
addition to photolytic destruction are
potential candidates for evaluation -
Purus Padre resin system, Carona
Reactor electro-oxidation technology,
and electron beam technology.
The performance and cost data
collected at McClellan will be valuable
components of technology transfer from
one site to another. The public-private
partnership can provide a more stream-
lined remedy selection process at other
Air Force facilities and at the private
company sites around the country,
whose contamination problems may be
similar to those found at McClellan.
In addition to the McClellan site,
TIO is pursuing demonstrations at up to
four additional Federal facilities,
including sites operated by the
Department of Energy (DOE), the
Army and the Navy. Clean Sites and
TIO are already in the process of
working with DOE s Innovative
Remediation Technology Demon-
stration Program to demonstrate
innovative enhancements to a ground
water treatment system at DOE s
Pinellas, Florida facility. Clean Sites and
TIO are also supporting the Remedial
Technology Development Forum which
will develop and test the Lasagna
technology at DOE s Paducah,
Kentucky Gaseous Diffusion Plant. The
Lasagna technology uses hydrofracturing
to place horizontal granular sheet
electrodes and treatment zones in low
permeable subsurface soil. Electro-
osmosis is then used to move
contaminated fluids through the
treatment zones where biological or
chemical activity destroys contaminants.
For more information on the public-
private partnership concept or the project,
call Dan Powell in EPA's Technology
Innovation Office at 703-308-8827 or
Ellen Fitzpatrick of Clean Sites, Inc. at
703-739-1262. We will update you from
time to time as the partnership progresses.
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Bio-Reactor continued from page 2
consisting of a single above-ground cell
(10xl2xlm) contained by a berm with
a PVC liner, drainage collection system
and dual controls for forced aeration,
below ground heating and irrigation.
Provisions were made to monitor
oxygen, temperature and oil content
and depth. The capacity of the Bio-
Pile is 80 tons. No fertilization was
necessary in the Bio-Pile; and, the oil
degraded uniformly with depth. After
five months of treatment in the Bio-
Pile, the concentration of hydrocarbon
content dropped from 2.6% to 2.2%.
The beginning waste concentration was
4.3% prior to the initial treatment in
Bio-Reactor. Toxicity testing
conducted on the treated Waste 1 with
2.2% residual hydrocarbon content
found no toxicity in: seed germination,
root elongation, microtox, earthworm
and algal test examinations. Plant yield
tests are currently being conducted.
For the second test, a new rototiller
was used which rode on the wails of the
Bio-Reactor to precisely till selected cells
without compacting the material. A high
volume aggregator was designed and
constructed. The second waste to be
treated, the DIMR, required less
pretreatment. In view of this, thorough
examination of major factors affecting
aeration were made in the nine test cells.
These included forced aeration, tillage
and aggregation in all combinations.
Work on the DIMR was aimed to
test long-held assumptions that tillage is
beneficial and lack of aeration limits the
degradation of hydrocarbons. All cells
were heated to 30 degrees Centigrade,
fertilized and irrigated as needed.
Surprisingly, no major differences in
hydrocarbon degradation could be
attributed to the three treatments.
During the four months of treatment,
hydrocarbons decreased over 80% from
an initial concentration of 10.8%.
The results from these two Bio-Reactor
tests show that highly contaminated
materials can be processed to produce
stable soil-like solids with characteristics
conducive to bioremediation. Tillage
and forced aeration may not be necessary
to achieve rapid oil degradation: but,
hydrocarbon wastes can be rapidly
degraded in heated units. Salts can be
readily leached and disposed of using
minimal quantities of water. Both the
Bio-Reactor and the Bio-Pile can be
operated 12 months of the year in the
Alberta climate.
We will keep you informed of future
B&Reactor developments, such as the
results ofwaste 3 tests (flare pit sludge).
For more detailed information on the Bio-
Reactor Project, contact Alex Lye of
GASReP at 905-336-6438. For progress
reports and more detailed reports, contact
Lisa Crichton at CAPP by phone at 403-
267-1 100 or by FAX at 403-261-4622.
There is a charge for the reports.
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OH 45242-04 19. Please refer to the document number on the cover of the issue if available.
Tech Trends welcomes readers' comments and contributions. Address correspondence to: Managing Editor, Tech Trends (5102W)
U.S. Environmental Protection Agency, 401 M Street, SW., Washington, DC 20460
United States
Environmental Protection Agency
National Center for Environmental
Publications and Information
P.O. Box 42419
Cincinnati, OH 45242-0419
EPA 542-N-94-004
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