United States
Environmental Protection
Agency
Solid Waste and
Emergency Response
(5102W) •
EPA-S42-N-95-002
April 1995
Issue No. 11
HYDROCARBON FILTRATION RECOVERY SYSTEM
By Laurel Staley, EPA Risk Reduction Engineering Laboratory
The InPlant Systems, Inc.
SFC Oleofiltration System
_.. _(SFC System) is a hydrocar-
bon recovery technology that
utilizes an innovative amine-
coated ceramic granule to
separate suspended and me-
chanically emulsified hydro-
carbons from aqueous solu-
tions. These granules form
an oleophilic filtration system
(the Oleofilter) that separates
some chemical emulsions and
reduces concentrations of dis-
solved hydrocarbons. The
Superfund Innovative Tech-
nology Evaluation (SITE)
Program conducted a dem-
onstration of the SFC 0.5
System at the Petroleum Prod-
ucts Corporation site near
Fort Lauderdale, Florida dur-
ing June 1994. The site is a
former oil recycling facility
where the ground water has
been contaminated with a va-
riety of organic and inorganic
constituents. Accidental re-
leases during the operation of
the facility deposited approxi-
mately 29,000 gallons of used
oil on the ground water sur-
face. The SFC System re-
moved at least 90% of the to-
tal recoverable petroleum hy-
drocarbon CTRPH) from the
emulsified oil/water feed
stream.
The SFC System com-
bines a conventional oil/wa-
ter separator, a coalescing
unit and the innovative
Oleofilter into one unit, re-
portedly capable of treating
virtually any oil/water mix-
ture. Units are available in
sizes capable of treating 2.2
to 50 gallons per minute
(gpm); other systems utilizing
stand-alone components are
capable of treating up to 600
gpm. All units operate at at-
mospheric pressure.
The oil/water mixture
feeds into the top of the unit
through a port, Port A, where
free floating oil is removed by
the oil/water separator. The
emulsified oil then flows
downward inside the outer
shell of the unit and upward
through a middle portion of
the unit that contains plates
that coalesce the oil. This oil,
together with the oil initially
captured by the oil/water
separator, is discharged from
the system through a second
port, Port B, at the top of the
unit. Final cleansing occurs
as the remaining material
flows upward through the
center of the unit and then
drains through the bed of
oleophilic granules. The
treated water than exits the
system through Port C.
For the SITE demonstra-
tion, the feed oil was recov-
ered from the site and thinned
with lighter petroleum prod-
ucts. The feed stream to the
SFC System was generated by
emulsifying the feed oil and
ground water using an air-
powered inline blender. The
average TRPH concentra-
tions for the feed streams
ranged from 422 to 2,267
milligrams per Liter (mg/L).
As stated, the SFC System re-
moved at least 90% of the
TRPH from the emulsified
oil/water feed stream —with
remaining TRPH concentra-
tions in the treated water at
15 mg/L or less. The effec-
tiveness of the oleophilic
granules were evaluated by
comparing the TRPH con-
centration in the water before
passing through the granules.
The granules were respon-
sible for a 95% reduction in
TRPH concentration for the
runs with similar feed oil.
The oleophilic granules ;are
produced by "grafting" a hy-
drophobic amine to a ceramic
substrate through a series of
substitution reactions. The
amine's hydrophobic proper-
ties attract hydrocarbons pre-
sent in an emulsion in water.
The hydrocarbons remain
attached to the amine by
weak charges while the
treated water exits the system.
When the Oleofilter becomes
saturated with hydrocarbons
and suspended solids, it can
regenerate itself by back-
flushing, which is built into
the SFC System.
EPA is publishing a Tech-
nology Capsule and Innova-
tive Technology Evaluation
Report this Spring.
For more information about
the technology and the report,
call Laurel Staley at EPA s
Risk Reduction Engineering
Laboratory at 513-569-7863.
I his may heyour last issue of
GROUND WATER
CURRENTS ifyoudaaot
immediaislf let as know that
yoirsvaBt to stay on. die rming
list The same message agplks
on. the malaiglSsts for these
4S5>-aS5>5}or mail csquesttb
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Road* BuEdiHg; 5> Ckdnnarij,
have the November 1994 issue
use the convenient form
inserted therein.
Recycled/Recyclable
Printed with Soy/Canola ink on paper that contains at least 60% recycled fibe
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BIOREACTOR
By Daniel Sullivan, EPA Risk
The ZenoGem™ process
is an integrated bioreactor
and ultrafiltration (UF)
membrane system that is
designed to remove biode-
gradable materials, includ-
ing most organic contami-
nants, from ground water
and wastewater. The Zeno-
Gcm™ technology was
evaluated at a Superfund In-
novative Technology Evalu-
ation (SITE) Program dem-
onstration at the Nascolite
Superfund site in New Jer-
sey. The ground water at
this 17.5 acre site had been
contaminated from past op-
erations at the facility,
which included manufactur-
ing of polymethyl methacry-
late plastic sheets, com-
monly known as plexiglass.
Methyl methacrylate
(MMA) is the major con-
taminant at the site, with
ground water levels approxi-
mating 12,000 milligrams
per liter (mg/L). In addi-
tion to the other volatile or-
ganic compounds at the
site, chemical oxygen de-
mand (COD) levels often
approximated 20,000 mg/L.
The ZenoGem™ SITE
demonstration achieved
100% removal of MMA
and between 84% and 95%
for COD.
Here's how ZenoGem'™
works. The wastewater en-
ters the enclosed tank bio-
reactor where a biomass
containing bacterial cultures
breaks down the organic
contaminants. In order to
maintain sufficient aerobic
AND MEMBRANE FOR VOCS
Reduction Engineering Laboratory
conditions and optimal pro-
cess temperatures, the con-
tents are constantly mixed
by the introduction of .air
bubbles through a series of
manifolds from the tank
bottom. Air is recycled, ex-
cept for the air that is emit-
ted into the atmosphere
through a pressure purge
vent, but not before it first
passes through a-carbon-ad-—
sorption unit.
Feed flow wastewater
treated in the bioreactor is
continuously fed into the
UF membrane system. The
membrane system consists
of a series of tubes, in ten-
foot modules and approxi-
mately three inches in di-
ameter, into which the cy-
lindrical membrane filters
are inserted. UF is a pres-
sure-driven cross flow filtra-
tion process (typically at 60
to 70 pounds per square
inch) in which the water to
be processed flows tangen-
tially over the surface of the
membrane filter that is ca-
pable of separating both in-
soluble..materials.(bacteria, _
colloids, suspended solids)
and higher molecular
weight soluble materials
from the treated water.
Thus, the treated filtrate
from the bioreactor flows
through the membrane
while the remaining feed, a
mixture of sludge solids and
unfiltered wastewater, is
concentrated and recycled
to the bioreactor where it
remains in the treatment
system for further treatment
for several weeks. Because
of the long sludge retention
time, the bioreactor size is
significantly reduced.
The SITE evaluation ran
for 89 days. During the
evaluation, shock loading
tests were performed that
demonstrated the flexibility
of the process to handle a
sudden increase (a four-fold
increase)-o£ concentration—-
of contaminants. Overall,
the process ran very
smoothly and could recover
quickly from upsets en-
countered in Superfund op-
erations such as loss of elec-
tricity, quadrupling of feed
concentration, free product
in feedstock and adverse
weather conditions. The
system was computer con-
trolled with an alarm that
activated a beeper retained
by the operator, demon-
strating that unattended op-
eration is extremely viable
for extended periods.
The resulting treated
water product from the pro-
cess was clear, odorless and
free of suspended solids.
For this project, the prod-
uct was sent to the publicly
owned treatment works
(POTW) which accepted
"the-produet-for*disposal at—
$22.50 per 6,000-gallon
tanker. The bioreactor,
which had processed ap-
proximately 28,000 gallons
of water, contained only
400 gallons of nonhazard-
ous sludge at the end of the
89-day period. The sludge
was stabilized and sent to a
landfill.
For more information, call
Dan Sullivan at EPA s Risk
Reduction Engineering Labo-
ratory at 908-321-6677.
, EpAJias_alimited-supply,,,
of some back issues of
both GROUND WATER
CURRENTS and TECH
TRENDS. To order copies
of these back issues, contact
our repository, the National
Center for Environmental
Publications (NCEPI). You
can order by FAX (513-489-
8695) or by mail (NCEPI,
P.O. Box 42419, Cincin-
nati, OH 45242-2419).
Please refer to the Docu-
ment Numbers when
ordering. Xhe
Number for GROUND
WATER CURRENTS is:
EPA-542-E-95-002. The
Document Number for
TECH TRENDS is: EPA-
542-E-95-001.
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ULTRASOUND EXAMINED FOR IN SITU MONITORING
By William H. Engelmann, EPA Environmental Monitoring Systems Laboratory, Las Vegas
Itrasound is a new con-
cept for field screening appli-
cable to in situ ground water
monitoring. EPA's Environ-
mental Monitoring Systems
Laboratory, Las Vegas
(EMSL-LV) has been exam-
ining the potential of com-
bining sonication (i.e., ultra-
sound) with existing measure-
ment technologies for moni-
toring specific classes of or-
ganic pollutants in water.
The research to date has ad-
dressed using ultrasound pro-
cessors to decompose aqueous
organochlorine compounds
into ions as a method to
screen organochlorine pollut-
ants in water. The research
demonstrated diat sonication
could produce anions specific
to the inorganic components
and that changes in ion con-
centrations before and after
sonication could be used to
monitor these pollutants.
Success to date with com-
pounds such as trichloroeth-
ylene (C2HC13), chloroform
(CHC13) and carbon tetra-
chloride (CC14) serve as
proof-ofiprinciple and form a
rationale for expanding the
research to other pollutant
classes.
In the research design, the
above compounds were tested
in the range of 3-40 parts per
million. The equipment
used was an ultrasonic system
with either a cup-horn or a
1/2 inch diameter horn-
probe; commercially available
probes such as ion selective
electrodes (ISEs), conductiv-
ity cells and pH electrodes.
The following parameters
were investigated: sonication
times (1-90 minutes); con-
tinuous vs. pulsed ultrasonic;
sample temperature (constant
30 degrees Celsius); sample
volumes (8-15 milliliters);
and water sources (deionized,
tap, well). The research on
sonochemistry of orga-
nochlorine compounds in
water gave much support for
using sonication in combina-
tion with changes in chloride
ion, conductivity and/or pH.
Common denominator in
the aqueous sonochemistry is
HC1, as it was the major
ionic product. However, the
mechanism and rate of the
reaction may differ markedly
depending on the conditions
under which the sonication is
performed.
Sufficient chloride ion was
formed under the sonication
conditions used to allow
measurement using a com-
mercially available chloride
ISE. It was apparent that 5
minutes sonication with the
cup horn at 60% pulse mode
or one minute sonication
with the 1/2 inch horn probe
resulted in close to 3% or
higher yields of chloride ion.
This was sufficient to achieve
detection with the commer-
cial chloride ISE for 37-40
ppm of C2HC13, CHC13 and
CC14. Lower concentrations
of these compounds should
be detectable by increasing
the chloride-ion yield.
It is believed that pH may
be useful in driving the reac-
tion toward HC1 as the final
product. Results from the
present research confirmed
the pH decreases. It also ap-
pears from the work that the
sonolysis of organochlorine
compounds was inhibited at
higher pHs. Bicarbonate arid
carbonate may act as hy-
droxyl radical scavengers,
thus inhibiting the orga-
nochlorine compound de-
composition. However,
more research is needed on
real-world samples to better
understand the implications
of pH for monitoring meth-
ods development using ultra-
sound.
Overall, the potential of
combining sonication with
commercially available mea-
surement technologies for
monitoring specific pollut-
ants in water is judged to be
high. The approach in using
sonication is applicable to
other organic compounds,
halides, phosphorus, nitrogen
and sulfur.
For more information, call the
principal researchers, Edward
J. Poziomek (phone: 804-683-
5643; FAX: 804-683-4628)
and Grazyna E. Orzechowska
(phone: 804-683-4105; FAX:
804-683-4628). A report on
the research, "Potential Use of
Ultrasound in Chemical
Monitoring," (Order No.
PB94-188190; cost: $17.50,
subject to change) can be or-
dered only from National
Technical Information Service,
5285 Port Royal Road,
Springfield, VA 22161 (tele-
phone: 703-487-4650). The
EPA Project Officer is Bill En-
gelmann at EMSL-LV at 702-
798-2664 by phone or 702-
798-2107 by FAX.
DNAPL TECHNOLOGIES EVALUATED
The EPA's Robert S. Kerr
Environmental Research
Laboratory has published a
report of a project that re-
viewed and evaluated in situ
technologies for remedia-
tion of dense nonaqueous
phase liquids (DNAPLs)
contamination occuring be-
low the ground water table.
The report reviews various
in situ technologies and
evaluates them on the basis
of their theoretical back-
ground; field implementa-
tion; level of demonstration
and performance; waste,
technical and site applica-
bility/limitations; and cost
and availability. The pro-
cesses discussed are: bio-
logical; electrolytic; con-
tainment and ground modi-
fication; soil washing; air
stripping; and thermal.
A summary of the project's
conclusions follows.
The report concludes that
the remediation of DNAPLs
faces challenges posed by
the site stratigraphy and
(continued on page 4)
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ii ii i i i • i ii in • iiiiiiiiniili!iii|i"
•••^
(continuedfrom page 3)
heterogeneity, the distribu-
tion of the contamination
and the physical and chemi-
cal properties of the
DNAPL. A successful tech-
nology has to be able to
overcome the problems
posed by the site complex-
ity and be able to modify
the properties of the DNAPL
to facilitate recovery, im-
mobilization or degrada-
tion. In addition, method-
ology must be adaptable to
different site conditions and
must be able to meet the"
regulatory goals.
Thermally based tech-
nologies are regarded as
among the most promising,
with steam enhanced ex-
traction (SEE) as probably
the most promising candi-
date. The CROW® pro-
cess relies on similar mecha-
nisms; however, it was not
clear whether the injection
of hot water and low qual-
ity steam offers an advan-
tage over SEE. Radio fre-
quency heating, which re-
lies on in-situ steam gen-
eration to be effective, has
only been tested in the va-
dose zone.
The report concluded
that the next group of
promising technologies are
the soil washing technolo-
gies because they can ma-
nipulate chemical equilibria
and reduce capillary forces.
A blend of akalis, cosol- — -
~ venTrarrd'surfactants V
probably the best combii.^.__
tion for a soil washing ap-
plication, each important
for its own reasons. Alkalis
can saponify certain DNAPLs
and affect wetability and
sorption; cosolvents pro-
vide viscous stability and
enhance solubility and mass
transfer between the aque-
ous phase and the DNAPL;
surfactants have the largest
impacts on solubilty and in-
terfacial tension reduction.
Water flooding is best ap-
plied in highly contaminated
areas as a precursor to these
methods.
The thermal and soil
washing technologies are
considered as best suited for
areas that are highly con-
taminated with DNAPLs.
However, these techniques
by themselves still may not
be able to achieve the cur-
' ptly mandated regulated
leanup standarclsr~TrTus7~'
consideration should be
given to using these tech-
nologies in combination
with the technologies suit-
able for long-term plume
management. The bio-
remediation techniques and
permeable treatment walls
hold the best promise.
A special problem is posed
by mixed wastes, heavy
metals and radionuclides
mixed with DNAPLs since
recovery at the ground sur-
face may not be desirable in
many instances. In such in-
stances, solidification/stabi-
lization (S/S) and vitrifica-
tion are among the most vi-
able in situ technologies.
Excluding radionuclides, in
situ S/S is the most promis-
ing candidate because of its
broadly demonstrated effec-
tiveness, cost and applicabil-
ity to the saturated zone.
A copy of the report,
NOLOGIES FOR IN-SITU
CLEANUP OF DNAPL
CONTAMINATED
SITES" (Order No. PB94-
195039), can be obtained for
$27.00 (subject to change)
from the National Technical
Information Service, 5285
Port Royal Road, Springfield,
VA 22161 (Telephone: 703-
487-4650).
MAILING LIST/ORDER INFO
To order additional copies of GtourKtWatee Co/rente, or to be incfucted on the permanent tnaitog tet,semJ a fax request to the National
Owner for Environments? Publicattens »nd Wbrmstion {NCEPf) at S f W89-8$95* or sand a ftwit r«j««t *» NCEPI* P«O, Sox 424) 9 > Cmdnnatf, OH 4524MW 9-,
Rease refer to the document number ott the cover of the issue if available.
*' <;o Wiettts Mid tontrB>« tons. Address <;ojTe^f>ortdehSe tP!
Crounrf Water tutt&Os, NCEPI, P,O, Box 42419 , Cincinnati, OH 45242-24(9!.
United States
Environmental Protection
Agency
Solid Waste and
Emergency Response
(5102W)
EPA-542-N-95-002
April 1995
Issue No. 11
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