United States
Environmental Protection
Agency
Municipal Environmental Research
Laboratory
Cincinnati OH 45268
Research and Development
EPA-600/S2-83-115 Dec. 1983
Project Summary
Three New Techniques for
Floating Pollutant Spill
Control and Recovery
William W. Bannister, Alfred H. Donatelli, William A. Curby, David L. Kan,
William J. Dalton, and David A. Porta
Three new techniques were investi-
gated for controlling and recovering oil
and floating hazardous material (HM)
spills in water bodies: amine carbamate
gelling agents, fluorescent agents for
nighttime operations, and environmen-
tal sonic sensing. The last two methods
are aimed at solving the serious prob-
lems posed by the poor visibility that
often accompanies spill situations.
Operational capability is nonexistent at
night or during other periods of low
visibility. But fast, continuous action is
essential to recovery operations, since
cleared areas can be covered again in
just a few hours as the unharvested
contaminant drifts back over the cleared
track. Moreover, skimmer operations
are most efficient with thicker pollutant
films. Thus, the spreading of the mate-
rial both increases the operational area
and decreses cleanup efficiency.
Amine carbamate gelling agents can
be used to gel oil and floating HM spills
quickly and completely to a solid con-
sistency. This gel is much more visible
than the liquid pollutant, does not
readily flow or spread, is very easily,
quickly, and completely recovered by
nets or sieves, is much less volatile (and
thus less hazardous with regard to fire
and toxicity), does not permeate sand or
other porous materials, and can be easily
regenerated into the original pollutant
and gelling components.
Cheap, nontoxic, and highly efficient
fluorescent agents can be applied in low
(50 ppm) concentrations onto spill areas
by conventional crop dusting or spray-
ing techniques. In open water with no
floating pollutant cover, the fluorescer
is dissipated into the water column; but
it is preferentially retained without
extraction into the water wherever there
are pollutant patches. At night, com-
mercial UV (ultraviolet, or "black" light)
display lights (or modified ordinary
mercury vapor street lights) can be
beamed over the spill area. Vivid fluor-
escent illumination occurs only from
pollutant spill patches, thereby making
such areas easily visible and extending
spill control and recovery operations
into nighttime hours.
Underwater sonic sensing techniques
were shown to be excellent means of
locating near-surface pollutants. In typ-
ical spill situations, a large portion of
the pollutant is in a floating globule near
the water surface as a result of surface
wave action. This condition is particu-
larly common for high-density mate-
rials. Sonic sensing can also provide
much-needed information on the rate of
dissipation of pollutant into the water
column. Sonic sensing and fluorescent
techniques also have excellent syner-
gistic capabilities when used together.
though both techniques are excellent
alone.
This Project Summary was developed
by EPA's Municipal Environmental Re-
search Laboratory, Cincinnati. OH. to
announce key findings of the research
project that is fully documented in a
separate report of the same title (see
Project Report ordering information at
back).
Introduction
Large quantities of oil and hazardous
materials (HM) are constantly being han-
dled by inland and marine transportation
and support equipment. Spills during
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transit or at producer and user storage
facilities pose a serious threat to the
health and welfare of the general public
and the environment. This study investi-
gates improved techniques for controlling
and recovering spills of oil and floating,
immiscible HM, particularly during per-
iods of poor visibility. Several concepts
were considered feasible: The use of
amine carbamate gelling agents, fluores-
cent agents, and environmental sonic
sensing equipment.
Amine carbamate gelling agents have
advantages over presently used absorbent
or gelling agents as a means of immobil-
izing the pollutants. They also consider-
ably increase visibility and greatly facili-
tate recovery with unconventional
equipment such as nets, sieves, etc.
The use of fluorescent agents provides
nighttime operational capabilities in
which long wave length ultraviolet (UV)
light causes floating patches of pollutant
to stand out vividly in the darkness. This
advantage could be extremely important
in high latitudes where winter nights are
quite prolonged and there is little or no
daylight. The system would also be quite
advantageous in tracking pollutant slicks
at night in any area of the world and
enabling spill control and recovery opera-
tors to maintain round-the-clock working
hours.
Environmental sonic sensing equip-
ment can be used to track near-surface
pollutant dispersed below the water
surface by wave action. This technique
has also proved invaluable for determin-
ing the rate of dissipation of the pollutant
into the water column.
Combinations of the above techniques
can also be used to afford synergistic
effects.
The purpose of this study was to inves-
tigate the effectiveness and practicality of
these concepts in simulated and actual
field environments. Tests were performed
at (1) the U.S. Environmental Protection
Agency (EPA) Oil and Hazardous Material
Simulated Environmental Test Tank
(OHMSETT)at Leonardo, NJ; (2) Bay F test
facilities in Edison, NJ; (3) the U.S. Naval
Submarine Base at New London, CT; and
(4) aboard EPA's ocean survey vessel
Antelope in Cape Cod Bay south of
Boston, MA.
Description of Techniques
Amine Carbamate Gelling
Agents
Recovery and control of pollutants on
inland and open waters is an environ-
mental problem of prime importance. One
of the greatest difficulties in such efforts
is the inability to attain complete recovery
of the pollutant, largely because of the
spread of unharvested pollutant back on
the track previously cleaned by skimmer
or similar equipment. Thus continued
passage of the recovery craft over the
contaminated water surface only reduces
the film thickness. Each time the craft
passes, the pollutant tends to flow back
over the cleaned track, seriously limiting
recovery efficiency.
Additives have been used in the past to
facilitate collection of pollutant spills by
gelation or other agglomerative process-
es. But invariably problems have arisen
with viscous interfaces between the
pollutant and the gelant that tend to
prevent complete and rapid distribution.
This project has developed an amine
gelling agent that can gel oil and HM
spills to a solid consistency quickly, safely,
and economically using readily available
amines. The latter are first added as a
spray to the pollutant to form a complete
solution before gelation, thus avoiding
the formation of viscous interfaces. Car-
bon dioxide is then added to react with the
amine and form a zwitterionic carbamate
salt that sets up a gelling matrix within
the spill:
R-NH2 + C02 - R-NHz-C02~
A three-component solution is used,
consisting of 70% dehydroabietylamine
(Amine D™, Hercules Corp.*), 15% eth-
anol, 15% 6,6-dimethylbicyclo [3.3.1]
hept-2-ene-2-ethanol ("Nopol"). The
ethanol is used to decrease the viscosity
of the amine, and the Nopol increases the
uptake of water into the gel, providing
increased gel strength. A dose rate of
approximately 15% of the gelling agent
formulation in the pollutant is required
for good gel consistency to occur.
This process provides several other
significant advantages in addition to
enabling fast and complete mixing before
carbonation to form the gel. The visibility
of the spill is greatly enhanced. The vivid
white color of the gelled pollutant makes
harvesting much easier, particularly in
conditions of low visibility. The rigidity of
the gel drastically reduces its mobility and
greatly lessens its tendencies to spread
back over previously cleaned tracks or
over ever-increasing areas. The rigidity of
the gelled pollutant also enables easier
'Mention of trade names or commercial products
does not constitute endorsement or recommenda-
tion for use.
and safer transportation after recovery
since free surface ("sloshing") effects are
eliminated. Thus solidified pollutant can
be transported by barge or other recovery
vessels much more quickly and safely,
particularly under adverse weather condi-
tions. Furthermore, simple containers
such as fiber pack drums, cardboard
boxes, and plastic or burlap bags can be
used for transporting and storing the
gelled pollutant. Should gelled pollutant
wash up on a beach or be accidentally
spilled onto a wood or other porous
surface, this solid form will not readily
permeate, whereas liquid pollutant will
be absorbed readily. Gelled pollutant also
has greatly reduced evaporation rates
and correspondingly increased flash
points. Thus flammability and toxicity are
also reduced.
Recovery of the gelled pollutant is
virtually complete, and there is no residual
sheen. The gelled pollutant is very com-
patible with conventional harbor skimmer
craft in spill control and recovery opera-
tions. Furthermore, it is relatively im-
mobile, with little or no tendency to move
away from the recovery craft or to drift
back over previously cleared areas.
Upon completion of the recovery pro-
cedure, the gelled pollutant can be sub-
jected to pressure filtration, and more
than 90% of the original pollutant (oil or
HM) can be extracted, uncontaminated by
gelling agent. The filter cake can then be
heated to about 100°C to drive off the
carbon dioxide and regenerate the amine
and Nopol for reuse.
Some limitations exist for this process.
Since a concentration of about 15% of the
amine mixture is needed to effect gelation
of pollutant, this process would probably
not be practical for very large spills.
Assuming that it would be feasible to
stockpile and transport twenty-five 55-
gal barrels of gelling agent, spills of about
10,000 gal could be handled by this
process. Also, high-viscosity pollutant
spills are probably poor candidates be-
cause of poor mixing of the gelling agent.
A few important types of pollutants are
not easily gelled—some lubricating oils,
vegetable oils, and highly acidic materials,
for example, which preferentially react
with the basic amine gelling agent. But
the great majority of floating pollutant
spills (including all organic materials cited
in Table 1) are compatible with this gelling
system.
The principle problem that remained
upon entering the final development work
in this phase of the overall project was the
means of delivering the gelling agents
(the liquid amine and Nopol combination
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on the one hand and the carbamating CO2
in a subsequent treatment) onto the spill.
Preferably the method would involve a
single pass with one recovery and control
craft.
Fluorescent Agents for
Nighttime Operations
Because considerable advantages were
derived from the enhanced visibility of
gelled oil and floating HM pollutants,
fluorescent agents were studied for their
ability to provide operational visibility at
night for pollutant spills (gelled or un-
gelled). The early work on this project
showed that commercially available, non-
toxic, and highly efficient fluorescent
agents with both oil and water compatibil-
ity could be applied in very low concentra-
tions to pollutant spills with excellent
results. Under laboratory conditions, such
fluorescent.agents were retained exclu-
sively in the patches of pollutant floating
on water surfaces, with little or no
extraction of the agent into the water
column over weeks or even months. With
illumination only by relatively low inten-
sity, long-wave UV irradiation, very vivid
fluorescent illumination from the floating
patches made them readily visible. More-
over, the organic materials most frequent-
ly involved in spill situations (Table 1)
were all shown to be compatible with the
fluorescence system. All that remained
was to demonstrate the process in the
field, with the main problems being the
delivery of the agent over such contam-
inated water surfaces and the means of
providing adequate UV illumination safely
and efficiently.
Environmental Sonic Sensing
Techniques
A large proportion of pollutant spills are
found near rather than at the water
surface. Such is particularly true of high-
density, low-viscosity, and/or high-polar-
ity (and thus more soluble) materials, and
of course it is especially the case in
turbulent waters. The rate of pollutant
dissipation into the water column is of
great importance from the standpoint of
ecology as well as recovery. Recently in
the IXTOX-1 oil spill, underwater sonic
sensing techniques were very useful in
locating near-surface pollutant.
The possible use of underwater sonic
sensing in association with fluorescent
agents was also investigated to deter-
mine the capability of the systems.
Tab/6 1. Chemicals Most Frequently Involved in Transportation Incidents
Commodity
All Modes
Deaths Injuries Incidents Deaths
Highway
Injuries Incidents Deaths
Railway
Injuries Incidents
Paints, enamel, lacquer
Corrosive liquids
Wet batteries
Flammable liquid"
Paint remover
Sulfuric acid
Hydrochloric acid
Electrolyte battery fluid
Plastic and resin solutions
Flammable or poisonous insecticides
Ink
Alcohof
Phosphoric acid
Sodium hydroxide
Acids'
Anhydrous ammonia
Nitric acid
Solvents"
Corrosive solids'
Compressed gases"
Radioactive materials
Methanol
Rust preventers and removers
Acetone
Xylene
Subtotal
All other hazardous materials
Total
0
12
0
5
0
2
0
0
0
0
1
0
0
2
1
13
4
0
0
2
0
0
0
0
1
43
168
211
28
306
23
211
60
422
104
5
12
28
0
13
32
178
79
404
82
4
56
62
2
10
1
4
7
2,133
3.180
5,313
13.304
7.959
5.429
3.076
2.828
2.218
1,760
1.310
1.206
894
829
760
671
635
573
470
437
374
370
512
377
350
266
219
216
47.043
22.988
70,031
0
10
0
5
0
2
0
0
0
0
1
0
0
2
1
12
1
0
0
2
0
0
0
0
1
37
128
165
26
263
20
188
59
212
76
5
;;
25
0
8
11
120
35
265
76
4
28
61
0
7
1
0
3
1.504
1.740
3.244
13.075
7.660
5.334
2.763
2.781
1.555
1.502
1.273
1.138
876
819
626
278
451
537
129
395
349
350
465
262
236
265
171
178
43.468
19.790
63,258
0
2
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
3
39
42
0
35
0
19
1
210
28
0
0
3
0
4
21
54
44
139
2
0
0
1
0
3
0
3
0
567
1.264
1,831
57
235
29
224
17
639
237
17
30
13
3
92
384
173
25
336
31
13
15
28
7
1O6
O
38
29
2.778
2.671
5.449
'Not otherwise specified. Note: Data are for reported incidents. 1971-78. Source: Department of Transportation.
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Procedures
A number of tests were performed
during the course of the investigation.
Their characteristics and objectives were
as follows:
1. Preliminary investigations were
sponsored by the U.S. Navy (1975-
76). These were conducted primarily
in the laboratories of the University
of Lowell and in the test facilities of
the JBF Company at Wilmington,
MA, to determine the tentative feasi-
bility of the amine gelation system.
2. Preliminary extrapolation of the
amine gelation system was made to
larger-scale situations by EPA in
1976-77. These were conducted
initially at the University of Lowell
and then extrapolated to OHMSETT.
This facility has a water surface 203
m long and 20 m wide, with moving
bridges for towing floating equipment
at speeds up to 3 m/s and wave-
making equipment capable of impos-
ing regular or harbor chop waves up
to 1.2 m high.
3. Tests at the EPA indoor tank (Bay F)
facility at Edison, NJ, were conducted
in 1978 to determine the feasibility of
using liquid or gaseous COz rather
than the solid dry ice previously used.
4. Prototype floating pollutant spill con-
trol and recovery equipment was
designed, constructed, and tested in
1978. This series of tests at
OHMSETT involved a control and
recovery craft that would affect gela-
tion of HM spills by simultaneous
spraying and carbonation of the spill
in a single pass.
5. Prototype portable pollutant spill
control and recovery equipment was
designed, constructed, and tested in
1979. This testing was performed at
the Bay F tank and involved prelim-
inary design of a recovery and control
craft that could be easily stored and
transported to remote spill sites.
6. Field tests of the recovery and control
craft were conducted at the U.S.
Naval Submarine Base in New
London, CT (1980-81). These tests
indicated the need for improvements
in design of the craft. As a result, a
prototype trimaran (three-hulled) raft
was constructed to meet the criteria
and requirements for a portable
recovery and control craft for use in
amine gelation work.
7. Fluorescent agents and acoustic
sensing were used for nighttime
floating pollutant spill control and
recovery operations (1978 to pres-
ent). These tests were performed at
the EPA OHMSETT facility, the Uni-
versity of Lowell, Sias Laboratories of
the La hey Clinic Foundation, Data-
sonics. Inc., Massachusetts Maritime
Academy, and on board the EPA
ocean survey vessel Antelope at sea
in Cape Cod Bay. The objectives of
these tests were to demonstrate full
operational capabilities of these
systems.
Results and Conclusions
Amine Carbamate Gelling
Agents
1. Amine D (70%) /Nopol (15%) /ethy
alcohol (15%) is an optimum gelling
agentfor pollutant spills. The extract-
ability of amine from a pollutant spill
into the water column affords low
concentrations in the water (about 1
ppm). The toxicity of Amine D to
marine life is low—of the same order
as that of ordinary hydrocarbons.
Gelled pollutant compositions are not
readily emulsified under ordinary
turbulent water conditions.
2. Commercially available, liquified CO2
(pressurized in cylinders or tanks) is
the optimum carbamating agent.
3. Conventional motor whaleboats or
similar craft or trimaran-type rafts
can be used as a single-pass, amine-
spraying/carbamating craft. On
either type of craft, a 1,700-lb CO2
transit tank can be installed along
with suitable containers of amine
gelling agent (e.g., kegs or barrels).
The amine is sprayed at the bow of
the vessel into the oncoming floating
pollutant spill, which is directed
either into carbonator chutes (on
either side of the boat) or between
the hulls (in the case of the trimaran).
C02 is directed from the transit tank
shortly behind the amine sprayers,
and the gelled oil is ejected astern.
Large spill areas (an acre or more)
could be gelled quickly—within 10
min or less. For relatively calm water
conditions, the trimaran design is
considered superior in terms of its
increased load of gelling agent, larger
crew, and easier equipment handling.
For waters with considerable harbor
chop conditions, the whaleboat de-
sign may be required.
Fluorescent Agents for
Nighttime Operations
1. Fluorescent agents can be applied by
spraying on liquid solutions or by
dusting with powder formulations.
Current tests strongly suggest that
dusting operations would be more
feasible, but both techniques have
proved extremely promising.
2. Very small concentrations of fluo-
rescer (about 50 ppm) in HM spills
provide excellent nighttime visibility.
3. The best dust formulations appear to
be intimate mixtures of the fluorescer
in powdered gypsum (CaS04). The
optimum spray formulation appears
to be a solution of the fluorescer in
di-ortri-propyleneglycolmonomethyl
ether solvents.
4. Uvitex OB™ (Ciba-Geigy Corp.) and
Yellow 131SC™ (Morton Chemical
Co.) have proved to be excellent,
nontoxic, cheap, and highly efficient
fluorescers.
5. The gypsum powder base is entirely
nontoxic and has no fire or other
hazards associated with it. Glycol
ether solvents have very low fire and
toxicity effects, and in the concentra-
tions contemplated for use, they
would probably present no significant
hazard.
Environmental Sonic Sensing
Techniques
1. Underwater sonic sensing tech-
niques were shown in an actual sea
trial to provide excellent synergistic
effects when used with the fluores-
cence technique. But both techniques
are also excellent when used alone.
2. Sonic sensing is particularly invalu-
able when a need exists to determine
the rate of pollutant dissipation into
the water column.
Recommendations
In view of the successful results of the
research discussed here and in the full
report, further work is proposed to extrap-
olate these results to full-scale opera-
tional situations. Construction, testing,
evaluation, and full use of appropriate
equipment and procedures are recom-
mended with the following objectives:
1. A prototype trimaran craft for use in
spill recovery and control operations
4
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in inland waters and in harbor situa-
tions should be designed, construc-
ted, tested, and used. The craft must
be portable, easy to assemble and
disassemble, and capable of support-
ing a load of approximately 12,000 Ib
for control and recovery operations
over an area of about an acre in about
5 min, (gelling up to 2,200 gal of
pollutant in a track up to 17 ft wide
and 1 -1/2 miles long). Equipmentfor
operations with fluorescent agents
under nighttime conditions will be
available. When disassembled, the
craft could be stored and transported
in a truck trailer space of about 8x12
x 6 ft along with all required chemi-
cals and supplies.
2. Full-scale tests should be performed
with applications of fluorescer from
aircraft or ships onto floating spills in
open water. Subsequent illumination
at night by UV light should be pro-
vided by modified conventional high-
way lighting equipment to permit
full-scale nighttime recovery and
control operations. Acoustic sensing
gear operated from recovery vessels
should be used to help locate and
track such spills and determine the
course of recovery and control work.
The full report was submitted in fulfill-
ment of Grant Nos. R804628-0 and
R806118-01 by The University of Lowell
under the sponsorship of the U.S. Environ-
mental Protection Agency.
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William W. Bannister and Alfred A. Donate/If are with the University of Lowell.
Lowell. MA 01854; William A. Curby is with the Sias Medical Research
Laboratories, Lahey Clinic Foundation, Burlington, MA 01803; DavidL. Kan is
with the Massachusetts Maritime Academy, Buzzards Bay, MA 02532; and
William J. Dalton and David A. Porta are with Datasonics, Inc.. Cataumet. MA
02534.
Uwe Frank is the EPA Project Officer (see below).
The complete report, entitled "Three New Techniques for Floating Pollutant Spill
Control and Recovery," (Order No. PB 84-123 694; Cost: $16.00, subject to
change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Municipal Environmental Research Laboratory—Cincinnati
U.S. Environmental Protection Agency
Edison, NJ 08837
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use $300
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