S-EPA
U.S. Environmental
Protection Agency
Office of Solid Waste
and Emergency
Response
Technology
Innovation Office
EPA/542/N-92/003 No. 9 June 1992
The applied technologies journal for Superfund removals and remedial actions and RCRA corrective actions
In Situ Biosparging with Biovenffing Cleans
Both Saturated and Unsaturated Zones
byD.H. Kampbell,
R.S. Kerr Environmental Research Laboratory
m he technique of biosparging
combined with bioventing is being
tested to remediate an aviation gasoline
spill at the Coast Guard's Traverse City,
Michigan, site. EPA's Robert S. Ken-
Environmental Research Laboratory has
already found that bioventing (injecting
air into the unsaturated zone above the
water table) and biosparging (injecting
air into the saturated zone below the
water table) promote biodegradation of
petroleum hydrocarbons (TPH). The
purpose of air injection is to volatilize
the contaminants into a soil gas
stream in both saturated and
Summer SITEs
unsaturated subsurface zones so that the
contaminants will be more readily
biodegraded by aerobic microorganisms in
the soil. This in situ method should
perform better and should be more cost
effective than above-ground soil removal
treatment or groundwater pump-and-treat
methods. Further, the system produces little or
no air emissions of hydrocarbon contaminants.
Prior to the pilot demonstrations at
Traverse City, laboratory treatability studies
were performed using surface soil from the
spill site. The studies demonstrated that
bioremediation from venting and sparging
would be feasible for this site. For the
Petroleum
hydrocarbons
Biosparging/
bioventing
Soil and
groundwater
w
'e are doing something new In
this issue of Tech Trends. Usually
we only tettyou about Superfund
Innovative Technology Evaluation
(SITE) demonstrations a/tefihey
happen and results are available,
in this Issue, we fet you know about
upcoming SITE demonstrations you
can visit this summer. See page 3
for details,
Also, the ATTIC Database
now contains all pre- and post-
demonstration information from 76
SITE Demonstration Program
Projects, See adjacent pie chart,
actual pilot
demonstration,
grass was
planted on a 75' x 90' rectangular area
over the plume of contamination. Next, a
nutrient solution was applied for
dispersion throughout the unsaturated
subsurface to support enhanced microbial
activity. For the bioventing part of the
demonstration, two blowers in a nearby
building were connected to aeration
transfer piping and to screened air
injection wells with adjustable depths to force
air flow into the unsaturated zone just above
the water table. Blower rates in the injection
(see Biosparging page 2)
SITE Demo Program Technologies in ATTIC
Materials Handling
4%
Solidification/Stablilization
14%
Thermal Destruction
11%
Biological
20%
Physical/Chemical (P/C)
32%
14%
P/C Thermal Desorption
P/C Radioactive
3%
76 technologies reported. Source documents include Demonstration Bulletins, Tech-
nology Profiles, Technology Evaluation Reports, and Applications Analysis Reports.
Printed on Recycled Paper
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SBP Membrane Filtration
Reduces Groundwater
Contaminants
PAHs, POP
Filtration
Groundwater
by Kim Kreiton,
Risk Reduction Engineering Laboratory
iSPA's Superfund Innovative Technology
Evaluation (SITE) Program demonstrated a
membrane microfiltration process that effectively —
separates contaminants and concentrates them into a smaller volume of groundwater
prior to treatment The SBP Technologies, Inc., membrane technology was tested in
Pensacola, Florida, at the American Creosote Works Site, where wood preserving
wastes such as polyaromatic hydrocarbons (PAH) and pentachlorophenol (TCP) had
seeped from capped former waste lagoons into an aquifer.
The membrane filtration unit consists of two stainless steel tubes. The outer
tube acts as a shell that houses the second porous stainless steel tube. There is a
space between the two tubes. On the inside of the inner tube a membrane forms and
is continuously regenerated from the recirculation of an aqueous slurry of membrane
formation chemicals. When feedwater enters the inner tube, the membrane func-
tions as a hyperfiltration unit. It retains contaminants with molecular weights of 200
and higher, while allowing a large portion of the water and the chemical species that
have a lower molecular weight to pass through the membrane walls where they are
collected in the space between the inner and outer tubes. The heavier contaminants
that cannot pass through the membrane wall are collected in a holding tank for sub-
sequent treatment The volume of water containing these heavier contaminants is
significantly less than the initial volume of water fed into the filtration tube, since
much of the water passed through the membrane into the space between the inner
and outer tubes. The permeated water can be disposed of in a manner consistent
with local permitting requirements. The cost of treating the reduced volume of wa-
ter with the greater concentration of heavier contaminants is less than that of treating
the original volume of waste water.
For the SITE demonstration, the filtration unit operated for six days. Each day,
approximately 1,000 gallons of feedwater were run through the unit during a two-
hour period. The concentrated contaminant water was recycled until the desired vol-
ume reduction was achieved. Average PAH concentrations in the feedwater were
approximately 47 milligrams per liter (mg/L) and average PCP concentrations were
2.4 mg/L. The system concentrated the feedwater to 20% of the original volume.
This contained 80% of original contaminants which represents approximately 30%
of the phenolic compounds and greater than 95% of the PAHs.
Based on the SITE demonstration, the SBP system appears effective in concen-
trating waste streams rich in PAHs but probably would not be suitable for phenols.
The system can be customized for a wide range of contaminants—for example,
waste streams containing high molecular weight or non-polar organic contaminants
such as polychlorinated biphenyls. The process may also be useful for separating
other emulsified or dispersed organics that do not lend themselves to simple physi-
cal phase separation.
An Applications Analysis Report and a Technology Evaluation Report describ-
ing the complete SBP SITE demonstration will be available in the Fall of 1992. For
more information now, and to get on the mailing list.for the Report, call Kim Kreiton at
the RiskReduction Engineering Laboratory in Cincinnati, Ohio, at 513-569-7328.
Biosparging
(from page 1)
wells were adjusted to five cubic feet per
minute. This low blower rate created a long
air stream retention time of 24 hours so that
microbes would have a chance to mineralize
the pollutants. The injected air volatilized
the contaminants into soil gas components.
After air injection began, TPH soil gas
levels were near 5,000 mg/L in the plot
area. Venting and subsequent
biodegradation eventually reduced soil gas
levels to less than 50 mg/L.
After completion of bioventing; bio-
sparging was started at the pilot demonstra-
tion. Aeration injection points were inserted
in the saturated zone of the plot area to a
depth of about ten feet below the water ta-
ble. The same blower injection system that
was used for the bioventing was used. The
injected air removed water soluble hydro-
carbons trapped in the soil capillaries and
groundwater by vaporizing the contami-
nants as the air bubbled up through the
groundwater. The contaminants, now in a
vapor phase, were then further aerated up-
ward into the unsaturated zone. Here they
were biodegraded by the bioventing process
described above.
The pilot demonstration showed that
biosparging was effective in removing the
water-solubilized hydrocarbons in the
groundwater. For example, after biosparg-
ing began, soil gas contaminant concentra-
tions in the unsaturated zone increased from
20 mg/L to 6,000 mg/L for volatile TPHs.
Final benzene levels in the underlying
groundwater near the water table were less
than 5 micrograms per liter (Mg/L) com-
pared to initial concentrations of 133 |J.g/L.
We already know that biosparging can
remove water-dissolved phase fuel in the
groundwater. However, when fuel globules
are entrapped in capillary matrices, the cap-
illaries act as a physical barrier that hinders
or prevents the injected air from transform-
ing the fuel into vapors. The full effective-
ness of sparging is being evaluated by
collection and analysis of vertical profile
core samples at different times. Final results
should be available by September, 1992.
For more information, call Don Kamp-
bell at the Robert S. Kerr Environmental
Research Laboratory in Ada, Oklahoma, at
405-332-8800.
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Upcoming SITE Pemes
everal Superfund
Innovative Technology
Evaluation (SITE) program
demonstrations are planned
for this summer. Below is a
brief description of the
technologies to be demon-
strated, the name of the
developers and the EPA
contacts^to call for more
information and visitor days.
Dechlorination
Region 1
Chemical Waste Management's (CWM)
DeChlor/KGME process involves the
dechlorination of liquid-phase haloge-
nated compounds, particularly polychlo-
rinated biphenyls (PCB). KGME, a
CWM proprietary reagent, is the active
ingredient in a nucleophilic substitution
reaction in which the chlorine atoms on
the halogenated compounds are re-
placed with fragments of the reagent.
The products of the reaction are a sub-
stituted aromatic compound (no longer a
PCB aroclor) and an inorganic chloride
salt. For more information, contact
Reinaldo Matias at 513-569-7149.
Thermal Gets Phase
Reduction
Region 5
A patented process from ELI EcoLogic
International, Inc., is based on the gas-
phase, thermochemical reaction of hy-
drogen with organic and chlorinated or-
ganic compounds at elevated tempera-
tures. At 850 degrees Celsius or higher,
hydrogen reacts with organic com-
pounds to produce smaller, lighter hy-
drocarbons. This reaction is enhanced
by the presence of water, which can also
act as a reducing agent. Because hydro-
gen is used to produce a reducing atmo-
sphere devoid of free oxygen, the possibil-
ity of dioxin or furan formation is elimi-
nated. Visitor days are projected for the week
of Septembers, 1992. For more informa-
tion, call Gordon Evans at 513-569-7684.
In Situ Biotreatment
Region 5
The geolock and bio-drain treatment plat-
form from International Environmental
Technology is a bioremediation system
that is installed in the soil or waste matrix.
The technology can be adapted to soil
characteristics, contaminant concentra-
tions and geologic formations in the area.
The system is composed of an in situ tank,
an application system and a bottom water
recovery system. All types and concentra-
tions of biodegradable contaminants can
be treated by mis system. Through direct
degradation or co-metabolism, microor-
ganisms can degrade most organic sub-
stances. Visitor days are projected for
August 1992. For more information, call
Randy Parker at 513-569-7271.
Solvent Extraction
Region 1
A soil restoration unit from Terra-Kleen
Corporation is a mobile solvent
extraction remediation device for the on-
site removal of organic contaminants
from soil. Extraction of soil
contaminants is performed with a mixture
of organic solvents in a closed loop,
counter-current process that recycles all
solvents. Terra-Kleen Corporation uses a
combination of up to 14 solvents, each of
which can dissolve specific contaminants
in the soil and can mix freely with water.
None of the solvents is a listed hazardous
waste, and the most commonly used
solvents are approved by the Food and
Drug Administration as food additives for
human consumption. The solvents are
typically heated to efficiently strip the
contaminants from the soil. For more
information, call Mark Meckes at 513-
569-7348.
Solvent Extraction
Region 5
The BEST Solvent Extraction process
from Resources Conservation Company
is a mobile solvent extraction system that
uses one or more secondary or tertiary
amines [usually triethylamine (TEA)] to
separate organics from soils and sludges.
The BEST technology is based on the
fact that TEA is completely soluble in
water at temperatures below 20 degrees
Celsius. For more information, call Mark
Meckes at 513-569-7348.
Thermal Desorptlon
Region 5
The Soil Tech anaerobic thermal desorp-
tion processor heats and mixes contami-
nated soils, sludges and liquids in a spe-
cial rotary kiln that desorbs, collects and
recondenses hydrocarbons from solids.
The unit can also be used in conjunction
with a dehalogenation process to destroy
halogenated hydrocarbons through a ther-
mal and chemical process. For more infor-
mation, call Paul dePercin at 513-569-7797.
Soil Washing
Region 10
The soil washing system from BESCORP
is a gravity separation system to treat
lead-contaminated soils. The advantage
of the system is that it is a very simple
system derived from mining technology.
It is assumed that solubilized lead will
partition to fine fraction and that using a
density separation system will remove the
dense metallic lead. For more informa-
tion, call Hugh Masters at 908-321-6678.
*U.S. Government Printing Office: 1992— 650-653
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ATTSC
Out of the ATTIC
Finding Cleanup Alternatives for TCE and PCE
• f you are looking for alternatives
for cleaning up a site containing soil
and groundwater contaminated with
trichloroethylene (TCE) and perchlo-
roethylene (PCE), you should con-
sider calling the Alternative Treat-
ment Technology Information Center
(ATTIC) database.
If you search the ATTIC database
using the key word "soil" you will
find over 750 reports. You could nar-
row this list by performing a free-text
search of the Summary Paragraphs for
"TCE" and "PCE". If you decide to
omit the Records of Decisions you
will find 31 reports on technologies
such as biodegradation, in situ soil
venting, radio frequency enhance-
ment, vacuum extraction, low-tem-
perature thermal technology, granular
activated carbon, soil washing, ultra-
violet oxidation and incineration. One
document that might catch your eye is
"Treatment Technologies for Hazard-
ous Waste Part II: Alternative Tech-
niques for Solvent Wastes." Another
document is from the Superfund Innova-
tive Technology Evaluation program and
is called "AWD Technologies, Inc. Inte-
grated Vapor Extraction and Steam Strip-
ping." This second report describes a sys-
tem that simultaneously treats groundwa-
ter and soil contaminated with volatile
organic compounds (VOCs). The tech-
nology can effectively remove over 90
of the 110 volatile compounds listed in
40 CFR Part 161, Appendix VIII., Re^ .
moval efficiencies were as high as
99.99% for VOCs in groundwater and
99.9% for VOCs in soil gas. [Note: This
AWD technology was previously featured
in the March 1991 issue of Tech Trends.]
From the Bulletins section of the
ATTIC system, you can download a
complete text of an EPA engineering bul-
letin on in situ soil vapor extraction, a re-
port of a demonstration of the steam in-
jection technology in Huntington Beach,
California, and an EPA engineering bul-
letin on granular activated carbon treat-
ment You can also download a technol-
ogy update from EPA's Center Hill Re-
search Facility in Cincinnati, Ohio, that de-
scribes advantages of using hydrofracturing
to increase the surface area in extraction wells.
By searching ATTIC'S Risk Reduction
Engineering Laboratory Treatability Data-
base for TCE and PCE, you can find infor-
mation on: chemical and physical proper-
ties; environmental data including risk esti-
mates for carcinogens and water quality cri-
teria; and performance data of water treat-
ment technologies^such^activated sludge,
chemical assisted clarification, air stripping,
trickle filtration, chemical oxidation, granu-
lar activated carbon, reverse osmosis, ultra-
violet radiation and packed activated carbon.
ATTIC provides the names and phone
numbers of several EPA personnel that
could be contacted for more information on
the technologies. There is no charge for ac-
cessing, searching or downloading informa-
tion from the ATTIC system. Information
on the ATTIC system is available from the
system operator at 301-670-6294 or from
Joyce Perdek of EPA's Risk Reduction En-
gineering Laboratory at 908-321-4380.
To order additional copies of this or previous issues of Tech Trends, call the publications unit at CERI at (513) 569-7562 and
refer to the document number on the cover of the issue. To be included on the permanent mailing list for Tech Trends, call
(703) 308-8800.
Tech Trends welcomes readers' comments and contributions. Address correspondence to:
Managing Editor, Tech Trends (OS-110W), U.S. Environmental Protection Agency, 401 M Street, S.W., Washington, DC 20460.
United States
Environmental Protection Agency
Office of Solid Waste and Emergency Response
Technology Innovation Office (OS-110W)
Washington, DC 20460
Official Business
Penalty for Private Use $300
EPA/542/N-92/003
FIRST CLASS MAIL
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
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