United States
Environmental Protection
Agency
x°/EPA
Office of
Research and Development
Cincinnati, OH 45268
EPA/540/R-94/525a
December 1994
Introduction
In 1980, the U.S. Congress passed the
Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA), also known
as Superfund, committed to protecting human health
and the environment from uncontrolled hazardous
waste sites. CERCLA was amended by the Superfund
Amendments and Reauthorization Act (SARA) in 1986.
SARA mandates the implementation of permanent
solutions and the use of alternative treatment
technologies or resource recovery technologies, to the
maximum extent possible, to clean up hazardous waste
sites.
State and Federal agencies, as well as private
parties, are now exploring a growing number of
innovative technologies for treating hazardous wastes.
The sites on the National Priorities List total over 1,200
and comprise a broad spectrum of physical, chemical,
and environmental conditions requiring varying types of
remediation. The U.S. Environmental Protection Agency
(EPA) has focused on policy, technical, and
informational issues related to exploring and applying
new remediation technologies to Superfund sites. One
such initiative is EPA's Superfund Innovative
Technology Evaluation (SITE) Program, which was
established to accelerate development, demonstration,
and use of innovative technologies for site cleanups.
EPA SITE Technology Capsules summarize the latest
information available on selected innovative treatment
and site remediation technologies and related issues.
These capsules are designed to help EPA remedial
project managers, EPA on-scene coordinators,
contractors, and other site cleanup managers
understand the types of data and site characteristics
needed to effectively evaluate a technology's
applicability for cleaning up Superfund sites.
This Capsule provides information on the InPlant
Systems, Inc. (InPlant) Oleofiltration technology, a
technology developed to separate suspended,
emulsified, and a portion of dissolved hydrocarbons
from water. The Oleofiltration technology was
evaluated under EPA's SITE Demonstration Program at
a former oil reprocessing facility in June 1994. This
Capsule presents the following information:
Abstract
Technology Description
Technology Applicability
Technology Limitations
Process Residuals
Site Requirements
Performance Data
Technology Status
Disclaimer
Sources of Further Information
References
Abstract
Oleofiltration is an innovative hydrocarbon recovery
technology that utilizes amine-coated, oleophilic
granules to separate suspended and mechanically
emulsified hydrocarbons from aqueous solutions. The
granules are also reported to separate several types of
chemical emulsions and to reduce concentrations of
dissolved hydrocarbons. The technology was
developed by Exxon Research and Engineering
Company and manufactured under exclusive license
and patent by InPlant of Houston, Texas. North
SUPERFUND INNOVATIVE
TECHNOLOGY EVALUATION
Printed on Recycled Paper
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American Technologies Group, Inc. (NATGI) is the sole
marketer of the technology.
The InPlant SFC System combines an innovative,
vertical-fin, coalescing separator and a patented, amine-
coated, ceramic granule filtration system (the Oleofilter)
into one unit, capable, according to InPlant, of treating
virtually any insoluble hydrocarbon/water mixture.
When the hydrocarbon/water mixture entering the
granules contains less than 500 milligrams/liter (mg/L)
of total recoverable petroleum hydrocarbons (TRPH)
and less than 50 mg/L of suspended solids, InPlant
claims that the SFC System will produce a treated water
effluent that contains 15 rng/L or less of TRPH. SFC
Systems operate at atmospheric pressure and are
available in sizes capable of treating 2.2 to 44 gallons
per minute (gpm). For treatment of larger flow rates
(up to 1,000 gpm), the coalescing unit is manufactured
as a separate stand-alone component from the
Oleofilter. The Oleofilters designed to treat larger flow
rates operate under low pressure [less than 30 pounds
per square inch (psi)]. The units can be operated
independently or installed in series on a single skid.
The latter configuration provides the same treatment
capabilities as the SFC System.
The SFC 0.5 System was evaluated under the EPA
SITE Demonstration Program at a former oil
reprocessing facility in Pembroke Park, Florida. This
Superfund site has a layer of free product (waste oil)
floating on groundwater that is contaminated with a
variety of organic and inorganic constituents.
Demonstration activities were initiated on June 2, 1994
and were concluded on June 18, 1994. The SFC 0.5
System has a treatment capacity of 2.2 gpm. The
waste oil recovered for the demonstration was
significantly more viscous than the oil collected for the
pre-demonstration treatability study. Consequently, the
feed stream to the SFC System was thinned with virgin,
lighter weight motor oil and then emulsified with site
groundwater using an air-powered inline blender. The
unit was evaluated over five separate operating cycles
("runs"). The feed stream was the same for all runs
except Run 4. The feed stream for Run 4 was a 3-to-1
mixture of thinned oil to kerosene emulsified in ground-
water. The TRPH concentration in the feed stream for
Run 4 was two to five times higher than the concentra-
tions for the other runs. These differences in Run 4
were implemented in an attempt to resolve filter back-
flushing difficulties associated with treating a very
viscous oil.
The first critical objective of the demonstration was
to evaluate whether the SFC System could remove at
least 90 percent of the TRPH from the emulsified oil/
water influent stream. Data indicate that the SFC
System met this goal for all runs except Run 4.
The second critical objective was to determine
whether the SFC System could reduce TRPH
concentrations in the treated water exiting the system
to 15 mg/L or less. When data are combined and
evaluated for the runs where the system operated within
normal design parameters (Runs 1 and 5), this goal was
met. For the other runs, the 15 mg/L threshold was
exceeded.
The third critical objective was to evaluate the
effectiveness of the oleophilic granules by comparing
the TRPH concentration in the oil/water emulsion
before and after passing through the granules.
Combined data for the runs with similar feed streams
(Runs 1, 2, 3, and 5) show the granules achieved a 95
percent reduction in TRPH concentration. A 65 percent
reduction in TRPH was obtained in Run 4.
Several noncritical objectives were evaluated for the
demonstration. One of these objectives was evaluation
of the relative effectiveness of the SFC System
hydrocarbon-capturing components. Results indicate
that the coalescing separator accounted for 45 to 62
percent of the total TRPH removed; the oleophilic
granules removed the corresponding 55 to 38 percent.
Another noncritical objective was to evaluate the
ability of the SFC System to remove suspended solids
(measured as non-filterable residue, NFR) from the
oil/water influent. NFR removal ranged from 27 percent
to 58 percent; NFR values in the oil/water influent were
generally below 50 mg/L
The ability of the SFC System to remove selected
semlvolatile organic compounds (SVOCs) was another
noncritical objective. SVOC concentrations in the
oil/water influent for Runs 1, 2, 3, and 5 were too low
to support any conclusions about removal effectiveness.
Run 4 had higher SVOC concentrations in the oil/water
influent. For this run, 75 percent removal of
naphthalene and 81 percent removal of 2-
methylnaphthalene were achieved.
During the demonstration, the SFC System did not
achieve steady-state operating conditions. The lack of
steady-state conditions apparently resulted from treating
the unexpectedly high-viscosity oil during a short-
duration evaluation of the technology. This situation
precluded the evaluation of two noncritical objectives.
An evaluation of the effectiveness of the coalescing
separator at segregating oil from water, as determined
by the percent water in the concentrated oil effluent,
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could not be made since the increased agitation that
occurred during backflushing resulted in overflowing of
backflushing water into the concentrated oil effluent
stream. An acceptable materials mass balance closure
could not be achieved since the amount of oil retained
in the unit was not constant across the runs.
Technology Description
SFC systems, which contain only one internal
moving part (a liquid-level control float), are designed to
be explosion-proof and are operated at atmospheric
pressure. Figure 1 shows the configuration and cross-
sectional view of the liquid flow through the SFC 0.5
System. The hydrocarbon/water mixture (oil/water
influent stream) feeds into the top of the unit through
Port A, moves downward inside the outer shell, and
flows upward past the vertical-fin coalescing separator.
Free-floating and emulsified hydrocarbons passing over
the coalescing fins combine with droplets already
adsorbed on the fins' surface.
The hydrocarbon droplets continue to increase in
size until the buoyancy of the droplets overcomes the
adsorptive forces. The droplets then release from the
fins, float toward the top of the unit, and are discharged
from the system through Port B as the concentrated oil
effluent stream. Final hydrocarbon filtration occurs as
the remaining emulsified and dissolved hydrocarbons
flow upward through the center of the unit and gravity
flow through the bed of amine-coated, oleophilic
granules. The majority of remaining hydrocarbons
attach to the granules, and the treated water (treated
water effluent stream) exits the system through Port C.
When the Oleofilter becomes saturated with
hydrocarbons and suspended solids (InPlant states that
15 to 20 liters of hydrocarbons can be retained by 100
liters of oleophilic granules), the granule bed
regenerates itself automatically by backflushing.
Backflushing is activated when the system reaches a
set pressure differential across the bed. The pressure
drop that initiates backflushing can be adjusted by the
operator to optimize filtration time, while preventing filter
breakthrough.
The backflush cycle takes 20 minutes. Water for
backflushing is pumped into the bottom of the system
through Port C. During the first 4 minutes of the
backflush cycle, only water is introduced. During the
next 8 minutes, both air (supplied by an external
compressor) and water are flushed through the filter.
The air increases the agitation that physically strips the
hydrocarbons from the granules. During the last 8
minutes of the backflush cycle, a water only rinse is
performed. The backflush water flow rate is equal to
the nominal throughput of the filter (2.2 gpm for the
SFC 0.5 System), and the air flow rate is 0.3 standard
cubic feet per minute (scfm) per gpm of water flow
(0.66 scfm for the SFC 0.5 System). Therefore, the
amount of air exiting the SFC 0.5 System during
backflushing is approximately 5 scf. The hydrocarbon/
water mixture generated during backflushing (backflush
water effluent stream) gravity flows from Port D near the
top of the unit (not shown in Figure 1) to a sump or
holding tank. The coalesced hydrocarbons within the
mixture typically separate within 10 to 30 minutes and
can be reprocessed through the SFC System, leaving
only the concentrated hydrocarbons to be recycled or
disposed of.
Although the design of the vertical-fin coalescing
separator within the SFC System is novel, the amine-
coated oleophilic granules are the innovative
component of the system. The granules separate
emulsions not treatable by conventional oil/water
separators. The oleophilic granules use a
montmorillonite (clay) base that has been heated to
800°C [1]*. The high temperature decomposes the
montmorillonite into an aluminum silicate that assumes
a crystalline, ceramic structure. The aluminum silicate
is then crushed into granules with diameters between
0.6 and 1 millimeter.
The granules are subsequently treated to attach the
oleophilic amine (see Figure 2). Through a series of
substitution reactions, an amine molecule bonds to a
silica atom, leaving a long hydrophobic (and oleophilic)
chain (C18H33) to which hydrocarbons are attracted [2,
pp. 15-16]. As the filtration process continues, hydro-
carbons flowing past the granules agglomerate with the
amine-attracted hydrocarbons, forming droplets. The
hydrocarbons remain attached to the amine, while the
separated water exits the system. The magnitude of
hydrocarbon uptake is inversely proportional to the
compounds' solubility in water and is controlled by a
partitioning process [3, p. 2054].
During backflushing, the hydrocarbon droplets
and hydrocarbon-laden solids are physically stripped
from the amines and, along with other entrained solids,
exit the unit with the backflushing water. The
hydrocarbons in the backflushing water are
predominantly coalesced and now can be removed by
conventional oil/water separation techniques. inPlant
has installed several systems where the hydrocarbon/
* [Reference Number, Page Number]
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Concentrated Oil
Outlet (Port B)
Coalesced Oil
Treated Water
Outlet/Backwash
Water Inlet (PortC)
Coalescing Plates
Note: The backwash water outlet
(Port D) is not shown in this view.
Source: Adapted from SFC 0.5x
Operating Manual, 1992.
Oil/Water Inlet
(Port A)
Water for
Oleophilic Filtration
Oleophilic Granules
Figure 1. SFC 0.5 Oleofiltration System Configuration.
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Only the significant parts of the mineral base,
consisting of silica molecules and hydroxyl groups,
are shown below.
OH
I
SI
/ ^
OH
1
SI
/ ^
Substitution of chlorines (chloride
hydroxyl groups.
Reaction with SO2CL
CL
I
SI
/ X
2
CL
1
SI
/ X
OH
1
SI
/ X
ions) for
OH
1
SI
/ X
Substitution of amines for chlorines.
Reaction with RNH2amine. R=C18
H R
X /
N
II
SI
/ X
H R
X /
N
II
SI
/ X
H33
OH
1
SI
/ X
Figure 2. Generation of oleophilic amine-coated
granules. Source: |2]
water mixture from backflushing is fed back into the
system, and the coalesced hydrocarbons are removed
by the vertical-fin coalescing separator. Any emulsified
hydrocarbons are captured by the oleophilic granules.
This approach eliminates the need for disposal of the
hydrocarbon/water mixture resulting from backflushing.
Technology Applicability
The SFC System is reportedly capable of treating
virtually an insoluble hydrocarbon/water mixture. The
stated advantage of this technology over other oil/water
separation techniques is its ability to separate
mechanical and several types of chemical emulsions.
InPlant claims that the SFC System can remove TRPH
from hydrocarbon/water emulsions to levels below 15
mg/L when the emulsion reaching the granules
contains less than 500 mg/L TRPH and less than 50
mg/L of suspended solids. According to InPlant, the
amine-coated granules have been proven effective on
a wide variety of hydrocarbons including gasoline;
crude oil; diesel; benzene, toluene, ethylbenzene, and
xylene (BTEX) compounds; and polynuclear aromatic
hydrocarbons (PAHs). The granules reportedly also
remove chlorinated hydrocarbons such as pentachloro-
phenol (PCP), polychlorinated biphenyls (PCBs), and
trichloroethane (TCA), as well as vegetable and animal
oils.
The ability of the oleophilic granules to separate
hydrocarbon/water emulsions and reduce dissolved
hydrocarbon concentrations to levels consistent with
other secondary treatment systems indicates the
potential for the SFC System to be used in conjunction
with other treatment technologies. Site remediation
techniques, such as steam injection-vapor extraction
and soil flushing, can generate hydrocarbon/water
emulsions that must be treated. Pumps used in
transferring oily water also can produce emulsions that
must be separated prior to further treatment. The SFC
System can be employed in these and other
applications including the remediation of contaminated
groundwater, in-process oil/water separation,
wastewater filtration, onsite waste reduction and
recovery, and bilge and ballast water treatment.
When used as a component of a treatment train,
the technology can significantly reduce hydrocarbon
loading to other downstream treatment equipment such
as air strippers and carbon filtration units. This reduced
loading results in increased on-line time and decreased
operating and maintenance costs for the treatment
train. Depending on local pretreatment standards,
treated water exiting the SFC System may be
acceptable for introduction to the sanitary sewer system
without further treatment.
Table 1 addresses the performance of the SFC
System based upon the nine evaluation criteria used for
decision-making in the Superfund feasibility study (FS)
process. If the SFC System is used as a component in
a treatment train, evaluation of the entire train also
should be performed.
Technology Limitations
The Oleofiltration technology concentrates
contaminants by separating free, emulsified, and some
dissolved hydrocarbons from water. Although the
toxicity of the water phase decreases, the toxicity and
mobility of the concentrated hydrocarbons are
unchanged. The concentrated hydrocarbons must then
be further treated or disposed. Even under ideal
conditions, the treated water typically will contain
between 4 and 15 mg/L of TRPH, requiring further
treatment prior to release at some sites.
Although the oleophilic granules are relatively
durable, collision between granules during filtration and
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Table 1. Nine Evaluation Criteria for the SFC System
Evaluation Criteria
Overall Protection of Human Health
and the Environment
Compliance with Federal applicable
or relevant and appropriate
requirements (ARARs)
Long-Term Effectiveness and
Performance
Reduction of Toxicity, Mobility, or
Volume through Treatment
Short-Term Effectiveness
Implementability
Cost
State Acceptance
Community Acceptance
Performance
• Provides both short-term and long-term protection by reducing
contaminants in groundwater.
• Prevents further groundwater contamination and offsite migration
caused by emissions during treatment.
• Demonstrated capability of reducing TRPH concentrations in
oil /water mixtures to 15 mg/L
• Concentrates but does not destroy contaminants.
• Effluent needs to be treated further to meet Federal Drinking Water
Standards if it is to be re-injected directly into the ground.
• Effluent may meet pretreatment standards for release to the local
publicly-owned treatment plant (POTW).
• May have to meet substantive requirements of a Resource
Conservation and Recovery Act (RCRA) treatment permit if treating
hazardous wastes.
• May have to meet substantive requirements of a Clean Air Act (CAA)
permit for air discharge during backflushing If volatile organic
compounds (VOCs) are present.
• Concentrated oil effluent may be regulated under the Toxic
Substances Control Act (TSCA) if poiychlorinated biphenyls (PCBs)
are present.
• Residuals treatment or recycling may be required (effluent water,
concentrated oil, oily water from backflushing).
• The technology concentrates contaminants, reducing waste volume,
but does not change the contaminants' mobility or toxiclty.
• Community and workers will be protected because the system is
almost entirely self-contained.
• Most systems are shipped pre-assembled or as modules that are
easily connected.
• Pretreatment of feed stream is typically not required.
• System is explosion-proof.
• If VOCs are present, a release (5 to 106 scfm) of contaminated air
will occur during backflushing.
• Additional treatment options may be needed for residuals.
• Oleophilic granules usage life is shortened if treating solutions with
pH>10.5 (granules become brittle) or chlorinated solvents with
concentrations >100 mg/L (weakens amine bonds).
• Backflush initiation needs to be adjusted, If treating oils of various
viscosities, to prevent breakthrough prior to backflushing.
• The cost to remediate 50 million gallons of contaminated
groundwater (22-gpm system with 95% on-line time) is approximately
$2.57 per thousand gallons.
• Since this system will most often be used as a component in a
treatment train, acceptance is tied to overall treatment acceptability.
• Should be generally acceptable to the public since emissions during
treatment are minimal.
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backflushing results in breakage. Broken granules that
are small enough to pass through the retention screen
are discharged from the system during backflushing.
Assuming a backflush frequency of every 10 hours,
InPlant states that approximately 8 percent of the
granules must be replaced every 12 months of
operation.
InPlant reports that the oleophilic granules are
sensitive to two chemical conditions, both of which
shorten the operational life of the granules. Treatment
of solutions having a pH greater than 10.5 for extended
periods of time makes the granules more brittle. The
increased breakage caused by this condition is
estimated to be an additional 4 percent every 12
months of operation. Treatment of solutions with
chlorinated solvents present in concentrations greater
than 100 mg/L weakens the amine bonds. A similar
attrition rate (an additional 4 percent every 12 months)
is reportedly caused by prolonged treatment of these
solutions.
The SFC System is reportedly less effective in
treating chemical emulsions containing anionic
surfactants than other types. Anionic surfactants affect
the ability of the granules' amine coating to attract and
retain hydrocarbons. InPlant states that use of SFC
Systems for the treatment of hydrocarbon/water
emulsions created by anionic surfactants resulted in
TRPH concentrations in the treated water of 50 to 80
mg/L. Although not evaluated during the SITE
demonstration, the granules reportedly are more
effective at removing hydrocarbons from chemical
emulsions containing cationic or nonionic surfactants.
Although the SFC System appears to effectively
treat oils of varying viscosities and densities,
adjustments to the backflushing cycle must be made to
reduce the amount of operator oversight required. The
pressure at which the backflushing cycle is initiated
must be adjusted to maximize filtration time while
preventing breakthrough of the hydrocarbons prior to
backflushing. During the SITE demonstration, the SFC
System apparently exhibited breakthrough prior to
backflushing when a kerosene and oil mixture was used
as the feed oil. InPlant reportedly has implemented
modifications to the system that allow in-field
adjustment of the pressure at which backflushing is
initiated. These modifications, combined with periodic
monitoring of system performance, should eliminate the
difficulties.
Treatment of high viscosity oils may foul the
granules, preventing effective backflushing. InPlant
claims that the use of hot water for backflushing or the
addition of a steam coil attachment to the system will
reduce the viscosity of most retained oils and allow
normal backflushing. During the SITE demonstration,
all but one of the runs used a very viscous oil that had
been thinned with virgin motor oil. Performance of
Runs 1, 2, and 3 resulted in fouling of the granules,
which had to be removed, washed in mineral spirits,
and reinstalled. Subsequent use of the hot water
(approximately 200 °F) increased the effectiveness of
the backflushing. Treatability studies encompassing the
full range of oil properties at a site, along with
provisions for hot water backflushing, if indicated,
should resolve backflushing difficulties.
According to InPlant, when the TRPH concentration
in the pre-granule water exceeds 500 mg/L, the TRPH
concentration in the treated water effluent may exceed
15 mg/L Run 4 of the demonstration had an average
TRPH concentration in the pre-granule water of 1,242
mg/L. The treated water effluent contained an average
concentration of 39 mg/L (these averages do not
include concentrations measured after filter
breakthrough). This reduction represents a 97 percent
removal of TRPH. Pilot-scale treatability testing prior to
full-scale implementation should determine the ability of
the unit to meet site-specific performance goals.
Process Residuals
The SFC System generates three process streams:
treated water, concentrated contaminants (during the
demonstration this wastestream was a concentrated
waste oil), and hydrocarbon-laden water from
backflushing. Additionally, if the feed stream contains
volatile organic compounds (VOCs), air emissions will
be generated during backflushing. Under optimum
conditions, the treated water will reportedly contain
between 4 and 15 mg/L of TRPH. Therefore, this
process stream may need to be further treated with a
tertiary process onsite or transported offsite for further
treatment. The concentrated hydrocarbon effluent
stream can be transported and disposed of offsite. If
the concentrated hydrocarbon is waste oil and meets
the waste oil specifications of 40 CFR 279, it can be
used as fuel. Two options exist for the water from
backflushing. This water can be fed back into the
system where the coalesced hydrocarbons will be
removed and the water filtered. Alternately, the water
from backflushing can be transported offsite for
treatment and disposal.
Depending on the size of the SFC System, air
emissions during backflushing range from 5 to 106 scf.
If the feed stream contains VOCs, a percentage of them
will become entrained in the backflushing air and exit
through the top of the system. Depending on the types
and concentrations of VOCs and applicable regulations,
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emissions controls such as carbon filters may be
required.
Site Requirements
Site requirements for the operation of the SFC
System include a level area, electricity, water, and
compressed air. The SFC System must be operated on
a level, non-shifting surface. A 9-square-yard pad of 6-
inch reinforced concrete will support the largest SFC
units. Additional space for storage of backflush influent
and effluent water must be available. If potable water
is used for backflushing, water lines or a service for
filling the water tank between backflushes must be
available. A water tank, with capacrty in excess of the
backflush volume, must be provided. Storage capacity
for the concentrated hydrocarbons and treated water
must be available (if the water is not being treated or
discharged immediately). Electrical power, consisting
of 4 kilovolt-amp (kVA), 460/230-volt, 3-phase service
must be available to operate the largest SFC Systems.
Smaller systems require 40-amp, 220-volt service.
Alternately, electrical power could be supplied by an
onsite mobile generator.
Current designs of the SFC System use pneumatic
controllers, requiring approximately 0.5 scfm of
compressed air. Additionally, the backflushing cycle
requires compressed air to increase agitation of the
granules. A source of compressed air capable of
producing a volumetric flow rate of 15 scfm and a
minimum air pressure of 100 psi will supply sufficient air
for both purposes on any size SFC System. InPlant has
recently begun replacing pneumatic controllers with
programmable logic controllers on SFC Systems.
Depending on the viscosity of the oil, hot water or
steam may be required for effective backflushing. A
portable hot water washer or steam generator therefore
may be required.
Performance Data
The SFC Oleofiltration System was accepted into
the SITE Demonstration Program in December 1992.
The Petroleum Products Corporation (PPC) Superfund
site in Pembroke Park, Florida was chosen as the
demonstration site. Accidental releases during the
operation of this former oil reprocessing facility resulted
in the deposition of approximately 29,000 gallons of free
product (waste oil) on the groundwater surface. The
groundwater underneath the oil is contaminated with a
variety of organic and inorganic constituents.
Prior to the demonstration, samples of oil from the
site were sent to NATGI for treatability studies. Aliquots
of the oil were combined with different volumes of
water, mixed with a blender, and poured through
separatory funnels containing oleophilic granules.
Samples of the water exiting the funnels were analyzed
for oil and grease by NATGI using EPA Method 413.1
[4]. Results of the study, presented in Table 2, showed
the granules to be effective at removing oil and grease
from the oil/water emulsions.
Table 2. NATGI Treatability Study Results
Six one liter samples of groundwater were contaminated with
20, 100, 300, 500, 2,000, and 10,000 mg/L of oil respectively,
mechanically emulsified with a high-speed mixer for 1 minute,
and manually poured into separatory funnels containing
approximately 0.5 liter of amine-coated ceramic granules. The
effluent (output) was analyzed for Oil and Grease using EPA
Method 413.1. [4]
Input
(mg/L)
20
100
300
500
2,000
10,000
Output
(mg/L)
2.5
4.0
5.0
3.1
3.6
2.5
Percent Removal
(mg/L)
87.5
96.0
98.3
99.4
99.8
99.9
The SFC 0.5 Oleofiltration System (2.2 gpm) was
evaluated during the SITE demonstration in June 1994
at the PPC site. Since the site did not have significant
amounts of oil emulsified in water, an artificial feed,
consisting of recovered waste oil emulsified in the
contaminated groundwater, was formulated to test the
system. The contaminated groundwater was obtained
by diverting a small stream from the site's full-scale
remediation system. This groundwater feed exited the
bottom of the full-scale oil/water separator, passed
through a flow meter, and entered an air-powered inline
blender used to create the emulsion to be used in the
demonstration.
The feed oil was collected from a sump where the
viscous oil had risen to the surface. Approximately 30
gallons of highly viscous oil were mixed with 15 gallons
of 10W-30-weight motor oil to reduce the viscosity of
the oil. The mixed oil had an average viscosity of 56.3
centistokes (cs). A peristaltic pump was used to deliver
the oil through a feed line to the inline blender. The
inline blender then created the oil/water emulsion that
was fed into the system. After passing through the SFC
System, the treated water effluent was returned to the
full-scale oil/water separator. Although the SFC System
was reportedly capable of reprocessing the oil/water
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mixture resulting from backflushing, the water layer
from backflushing was returned to the full-scale
oil/water separator. The concentrated oil effluent and
the oil layer from backflushing were stored in drums for
offsite disposal.
Samples were collected from the groundwater feed,
oil feed, emulsified oil/water influent, water prior to
entering the granules (pre-granule water), treated water
effluent, backflushing effluent, and concentrated oil
effluent.
The demonstration consisted of five separate runs.
Runs 1, 2, 3, and 5 used the mixed feed oil. Run 4
used a 3-to-1 mixture of the previously mixed oil to
kerosene. The feed oil for Run 4 had an average
viscosity of 30.1 cs. Samples were collected for TRPH
analysis using EPA Method 418.1 [4]. Additional
samples were collected and analyzed for NFR, SVOCs,
and percent water using EPA Method 160.2 [4], EPA
Method 8270 [5], and ASTM Method D95-83 [6]. The
average TRPH concentrations for the oil/water influents
ranged from 322 to 2,802 mg/L
Due to operational difficulties associated with filter
backflushing, only one complete run (Run 1) was
accomplished. Runs 2 and 3 were shortened because
the backflushing cycle preceding each run did not clean
the granules sufficiently to allow the pressure differential
across the granule bed to reset to InPlant's
specifications of zero inches of mercury (in. Hg). The
backflush triggering pressure of 16 in. Hg was
consequently reached sooner. The operational
difficulties were apparently caused by the high viscosity
and solids content of the feed oil, which were different
from the oil provided to InPlant for the treatability
studies. InPlant claims that adjustments prior to unit
delivery and the addition of a steam coil attachment
would have resolved the difficulties.
Run 4 was terminated when visible oil appeared in
the treated water effluent. Analytical results confirmed
that filter breakthrough had occurred. Run 5 was
terminated when the level of pre-granule water in the
unit had risen to the height where it was discharging
through the backflush water outlet. Additionally, it was
thought that visible oil appeared again in the treated
water effluent (analytical results indicated that this
conclusion was inaccurate). Table 3 presents TRPH
results for the oil/water influent, pre-granule water, and
treated water effluent for all five runs. Table 4 presents
results for NFR, naphthalene, and 2-methylnaphthalene
for the oil/water influent and treated water effluent.
Results from the first sample collected in each run have
not been presented since the collection time (t = 10
minutes) was less than the calculated residence time of
the unit (i.e., water entering the unit at initiation of the
run had not yet reached the treated water sample port).
Table 5 presents a summary of project objectives,
results, and conclusions for the demonstration.
Due to operational differences among some of the
runs, demonstration data have been evaluated using
several scenarios. Since Runs 1, 2, 3, and 5 used the
same feed oil, data from these runs were pooled and
evaluated together. Within this group, only Runs 1 and
5 were initiated with the granules backflushed
sufficiently for the initial pressure differential across the
granule bed to approach InPlant's specification of zero
in. Hg. Consequently, evaluation of demonstration
objectives state a result for the pooled data from Runs
1, 2, 3, and 5 (13 data points), and a result for the
pooled data from Runs 1 and 5 only (8 data points).
Since Run 4 used a different type of feed oil and oil
feed rate, data from this run were evaluated separately.
During this run, the concentration of TRPH present in
the pre-granule water exceeded InPlant's stated
limitation of 500 mg/L Consequently, the
demonstration objective of achieving 15 mg/L or less in
the treated water effluent was not evaluated. Addition-
ally, InPlant claims that the pressure differential across
the granule bed at which backflushing was triggered (16
in. Hg) was set to accommodate the 500 mg/L
maximum TRPH concentration, and the higher concen-
tration was responsible for the apparent filter
breakthrough. Accordingly, Run 4 was evaluated using
the data for the entire run (5 data points) and also using
only the data prior to filter breakthrough (3 data points).
The SFC System did not achieve steady-state
operating conditions during the demonstration. This
situation precluded the evaluation of two noncriticai
objectives. An evaluation of the effectiveness of the
coalescing separator at segregating oil from water, as
determined by the percent water in the concentrated oil
effluent, could not be made since the increased
agitation that occurred during backflushing resulted in
overflowing of backflushing water into the concentrated
oil effluent stream. An acceptable materials mass
balance closure could not be achieved since the
amount of oil retained in the unit was not constant
across the runs.
InPlant has provided performance data from a
bench-scale study of the ability of the oleophilic
granules to remove TRPH, BTEX, and PAHs [7]. The
study, conducted on tank water bottoms from a
condensate tank at a bulk petroleum storage and
transfer facility in The Netherlands, achieved petroleum
hydro-carbon concentrations in the outlet samples of
1.43 and 2.49 mg/L for times t=10 minutes and t=105
-------
Table 3. Summary of TRPH Analyses
Elasped
Time
Run (min)
1 60
1 120
1 180
1 240
1 300
2 30
2 60
2 90
3 20
3 40
4 45
4 90
4 135
4 180
4 240
5 45
5 75
5 105
5 135
Influent
Concentration
(mg/L)
842
989
1240
1120
1170
366
322
484
988
981
1991
2680
2004
2802
1630
681
NA
565
2448
Pre-granule
Concentration
(mg/L)
691
499
651
445
487
301
227
261
386
137
1260
997
1470
1302
955
456
351
191
189
Effluent
Concentration
(mg/L)
29.4
20.3
13.8
10.9
17.4
16.8
32.2
25.7
25.0
20.7
43.3
26.7
47.5
484
1470
17.2
14.7
7.4
10.1
NA - Not analyzed by laboratory.
10
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Table 4. Summary of NFR and Specific SVOC Analyses
Run
1
1
1
1
1
2
2
2
3
3
4
4
4
4
4
5
5
5
5
Influent
NFR
(mg/L)
19
11
18
24
20
30
23
26
31
37
32
19
40
34
24
29
22
23
20
Effluent
NFR
(mg/L)
14
6
7
6
11
14
14
13
10
16
17
29
20
21
12
9
9
9
6
Influent
Naphthalene
fc>g/L)
13
***
12
***
6j
12
***
12
13
***
210
***
250
***
100
39 j
***
20
***
Effluent Influent
Naphthalene 2-Methylnapnthalene
G/g/L) 0/g/L)
10 u
***
10 u
***
10 u
10 u
***
10 u
10 u
***
10 u
***
25
***
90
20
***
10 u
***
11
***
10
***
5j
7]
***
7]
7j
***
320
***
410
***
140
38]
***
15
***
Effluent
2-Methylnapnthalene
0/g/L)
10 u
***
10 u
***
10 u
10 u
***
10 U
10 u
***
10 u
***
21
***
130
14
***
10 u
***
u below detection limits
j estimated value
*** no sample collected
11
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Table 5. Summary of Project Objectives, Results, and Conclusions
Objective
Results
Conclusions
Critical Objectives
Evaluate claim of 90%
minimum removal of TRPH2
from oil/water emulsion.
Evaluate claim of 15 mg/L
maximum TRPH concen-
tration in effluent. (Test
hypothesis that sample
mean is not statistically
significant from 15 mg/L at
the 90% confidence interval.)
Determine TRPH removal
effectiveness of oleophilic
granules.
Noncritical Objectives
Determine the relative
contributions to TRPH
removal of the coalescing
unit and oleophilic granules.
(Determine percentage of
total TRPH removal
accomplished by the
coalescing unit and by
granules.)
Evaluate the SFC System's
ability to remove suspended
solids from the oil/water
influent.
Examine the difference in %
moisture between feed oil
and oil effluent.
Evaluate the ability of the
SFC System to remove
naphthalene, 2-methyl-
naphthalene and 1,2-
dichlorobenzene.
Determine whether mass
balance closures of 80 to
120% can be achieved for
TRPH and total materials.
Establish a +50 to -30%
treatment cost estimate
The overall TRPH removals were:
98%-Runs 1,2,3, and 5
(98% - Runs 1 and 5 only)
81% - Run 4, all data
(98% - Run 4, data prior to breakthrough)
The average effluent concentrations were:
18.7 mg/L - Runs 1,2,3, and 5
(15.7 mg/L - Runs 1 and 5)
414.3 mg/L - Run 4, all data
(39.2 mg/L - Run 4, data prior to
breakthrough)
The TRPH removals of granules were:
95% - Runs 1,2,3, and 5
(96% •• Runs 1 and 5)
65% - Run 4, all data
(97% Run 4, data prior to breakthrough)
The TRPH removals for coalescing unit:
61% - Runs 1,2,3, and 5
(62% • Runs 1 and 5)
57% -Run 4, all data
(45% • Run 4, data prior to breakthrough)
The TRPH removals for granules were:
39% - Runs 1,2,3, and 5
(38% - Runs 1 and 5)
43% - Run 4, all data
(55% - Run 4, data prior to breakthrough)
The NFRl! removals were:
57%- Runs 1,2,3, and 5
(58% - Runs 1 and 5)
34% - Run 4, all data
(27% - Run 4, data prior to breakthrough)
Could not be evaluated as system did not reach
steady-state conditions during demonstration.
The SVOC4 removals were:
75% - Naphthalene for Run 4, all data
81% - 2-Methylnaphthalene for Run 4,
afl data
Mass balance closures were not possible due to
lack of steady-state conditions.
Cost for treating 50,000,000 gallons of water
(95% on-line time) is $2.57 per 1,000 gallons
Runs 1, 2, 3, and 5 met the objective. Runs 1 and 5
met the objective. Overall objective not met for
Run 4 using all data. Objective met for Run 4 using
data prior to breakthrough.
The average of Runs 1, 2, 3, and 5 is statistically
different from the objective. The average of Runs 1
and 5 is not statistically different from the objective.
For Run 4, the TRPH concentration in the pre-
granule water exceeded the developer's stated
limits. Therefore, no conclusions about this
objective are stated for Run 4.
The granules were able to significantly reduce TRPH
concentrations.
For Runs 1, 2, 3, and 5, the coalescing unit
removed more TRPH than the granules by a factor
of 1.56. For Runs 1 and 5, the coalescing unit
removed more TRPH than the granules by a factor
of 1.63. For Run 4 using all data, the coalescing
unit removed more TRPH than the granules by a
factor of 1.32. For Run 4 prior to breakthrough, the
granules removed more TRPH than the coalescing
unit by a factor of 1.22.
For Runs 1, 2, 3, and 5 and Runs 1 and 5, the NFR
removal was significant. The NFR removal was less
for Run 4 using all data and for Run 4 using data
prior to breakthrough.
No conclusions can be made regarding the ability
of the coalescing unit to produce a low-moisture,
concentrated oil stream.
No conclusions can be made regarding the removal
of specific SVOCs for Runs 1, 2, 3, and 5 due to low
influent concentrations. The SFC System
significantly removed both naphthalene and 2-
methylnaphthalene during Run 4. (1,2-
dichlorobenzene was not present above detection
limit.)
No conclusions can be made regarding either TRPH
or total mass balance closure.
Cost estimates are highly dependent on site-specific
factors. Actual costs may vary significantly.
1 Indicated results obtained by combining data from specified Runs 3
(e.g., "Runs 1 and 5" Indicates data pooled from those Runs only) 4
2 TRPH Is total recoverable petroleum hydrocarbons (EPA Method 418.1)
NFR is non-filterable residue (a measure of suspended solids)
SVOC Is semlvolatlle organic compound
12
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minutes, respectively. The study also indicated effective
removal of PAHs but less effective removal of BTEX.
Technology Status
The SFC System is currently being used in industrial
applications including:
• Treatment of process water at a laboratory in
Oildale, California
• Treatment of wash water effluent at a car wash -
the effluent reportedly meets the pretreatment
water standards for Santa Clara, California
• Treatment of wash rack waste water in Ventura,
California
• Treatment of storm water runoff in order to meet
National Pollution Discharge Elimination System
(NPDES) regulations in Houston, Texas
Disclaimer
Although the technology conclusions presented in
this report may not change, the data have not been
reviewed by EPA Risk Reduction Engineering
Laboratory Quality Assurance personnel.
Sources of Further Information
EPA Contact:
SITE Project Manager
Laurel Staley
U.S. EPA
Risk Reduction Engineering Laboratory
26 West Martin Luther King Drive
Cincinnati, Ohio 45268
(513) 569-7863
Technology Contact:
Cathryn Wimberly
Aprotek
3316Corbin Way
Sacramento, CA 95827
(916) 366-6165
References
1. Aprotek Product Literature, Aprotek, Inc.,
Sacramento, California, 1993.
2. Subra Company Product Literature,
Company, New Iberia, Louisiana, 1993.
Subra
3. Smith, J.A. and P.R. Jaff6. Comparison of
Tetrachloromethane Sorption to an Alkylammonium
Clay and an Alkyldiammonium Clay. Environmental
Science and Technology, Vol. 25, pp. 2054-2058,
1991.
4. U.S. Environmental Protection Agency. Methods for
Chemical Analysis of Water and Wastes. EPA
600/4-79-020, 1983.
5. U.S. Environmental Protection Agency. Test
Methods for Evaluation of Solid Waste, Third Edition.
SW-846, December 1987.
6. American Society for Testing and Materials. Annual
Book of ASTM Standards, 1992.
7. Treatability study performed by HEAD Consultancy
at the University of Twente, The Netherlands, May
1993.
13
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