w.
United States
Environmental Protection
Agency
Office of Solid Waste and
Emergency Response
Washington, DC 20460
May 1994
•PA Proceedings
Fifth Forum on Innovative
Hazardous Waste
Treatment Technologies:
Domestic and International
Chicago, Illinois • May 3-5, 1994
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EPA/540/R-94/503
May 1994
ABSTRACT PROCEEDINGS
FIFTH FORUM ON INNOVATIVE HAZARDOUS WASTE
TREATMENT TECHNOLOGIES:
DOMESTIC AND INTERNATIONAL
Chicago, Illinois
May 3-5, 1994
TECHNOLOGY INNOVATION OFFICE
OFFICE OF SOLID WASTE AND EMERGENCY RESPONSE
U.S. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, DC 20460
AND
RISK REDUCTION ENGINEERING LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OH 45268
Printed on Recycled Paper
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NOTICE
j
Although this document has been published by the U.S. Environmental Protection
Agency, it does not necessarily reflect the views of the Agency, and no ;official
endorsement should be inferred. Mention of trade names or commercial products does
not constitute endorsement or recommendation for use.
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ACKNOWLEDGEMENTS
The Fifth Forum on Innovative Hazardous Waste Treatment Technologies: Domestic and
International was sponsored by the U.S. Environmental Protection Agency's Technology
Innovation Office (TIO), Walter Kovalick, Director. The Forum programs and activities
were planned by a committee consisting of the following members: Thomas De Kay, U.S.
EPA, TIO; Deborah Griswold, U.S. EPA, Region VI; Fran Kremer, U.S. EPA, Center for
Environmental Research Information; Lisa Kulujian, Science Applications International
Corporation (SAIC); Donna Kuroda, U.S. Army Corps of Engineers; Steve Mangion, U.S.
EPA, Region V; and Donald Sanning, U.S. EPA, Risk Reduction Engineering Laboratory.
The Forum was planned in partial fulfillment of Contract No. 68-W2-0026 by SAIC under
sponsorship of the U.S. Environmental Protection Agency. Thomas R. De Kay of TIO
was the Work Assignment Manager responsible for coordinating this project.
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ABSTRACT
On May 3-5, 1994, the U.S. Environmental Protection Agency's Technology Innovation
Office and Risk Reduction Engineering Laboratory hosted an international conference in
Chicago, Illinois to exchange solutions to hazardous waste treatment problems. During
this conference, the Fifth Forum on Innovative Hazardous Waste Treatment Technologies:
Domestic and International, scientists and engineers representing government agencies,
industry, and academia attended over 40 technical presentations and case studies
describing domestic and international technologies for the treatment of waste, sludges,
and contaminated soils at uncontrolled hazardous waste disposal sites. A Session was
also held on opportunities in research and commercialization, which included
presentations on export assistance programs and partnerships with EPA in developing
innovative technologies. Over 70 posters were on display.
This compendium includes the abstracts of the presentations from the conference and
many of the posters that were on display. The abstracts are published as received from
the individual authors and their institutions.
IV
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PAPER PRESENTATION ABSTRACTS
Radio Frequency Heating
Thermal Desorption of Coal-Tar Contaminated Soil from Manufactured Gas Plants 6
The ECO LOGIC Process - a Gas Phase Chemical Reduction Process for PCB Destruction 11
Advanced Waste Management Indirect Thermal Treatment Technologies .... 16
Bioremediation of Soils and Sediments Using Daramend™ ................... 21
Biodegradation of Dinoseb Using the Simplot Process 26
Biological Slurry Treatment as Part of an Inner City Model Remediation Project of a 10 000 M3 Soil
Contaminated with Methylated Phenoles Underneath the GOLDBEKHAUS in Hamburg' Germany . . 29
BTEX, Mineral Oil, and Pesticides Remediations Using the UVB Technology 35
Controlling Fugitive Emissions from Excavation of Contaminated Soil: a Case Study 40
Remediation of an Area Containing Chemical Warfare Agents 45
Technology for Hazardous Gaseous Pollutants Treatment by Double Electron Beam Gas
Excitation
Installation for Sewage Sludge Hygienization by Electron Beam Application 53
Soil Washing, from Characterization to Tailor-Made Flow-Diagrams, Results of Full-Scale
Installations
"*""""""••••••••••••••".•• O /
Soil Washing and Terramet™ Lead Leaching/Recovery Process at the Twin Cities Armv
Ammunition Plant _ •
: • 52
The B.E.S.T.® Solvent Extraction Process for Remediation of Pesticide Contaminated Wastes 67
Cleaning Organically Contaminated Soil by Steam Extraction - Pilot-Scale Experiments and
Implementation on an Industrial Scale 72
Hydraulic Fracturing to Improve Remediation of Contaminated Soil 79
X-Ray Treatment of Organically Contaminated Aqueous Solutions 84
Thermal Desorption of SVOC, VOC, and Pesticide Contaminated Soil at the Pristine Facility Trust
Superfund Site, Reading, Ohio 89
Thermal Desorption/Base Catalyzed Decomposition (BCD) - a Non-oxidative Method for Chemical
Dechlormation of Organic Compounds 90
Radiation Processing of Groundwater for Chlorinated Solvents With and Without Combination of
Ozone . 97
The Oxyjet Technology: an Innovative Approach for the Wet Oxidation of Hazardous Wastes 102
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Full-Scale Application of Advanced Photochemical Oxidation to Groundwater Treatment •• 108
113
The CAV-OX® Process
A New Air Stripping Method to Economically Remove VOCs from Groundwater 121
Pilot Scale Investigations of the In Situ Immobilization of Highly Arsenic Contaminated Soil ....... 125
Colloid Polishing Filter Removal of Heavy Metals, Uranium and Transuranic Pollutants from
Groundwater at the DOE Rocky Flats Plant . •
Application of Mineral Beneficiation Processes for Lead Removal at a Camp Pendleton, CA,
Small Arms Firing Range
129
136
POSTER PRESENTATION ABSTRACTS
Contaminated Soil Treatment Through Davy International IPDOCS Process ;.. .
Controlled Vapor Circulation in Subsurface Materials to Enhance the Bioremediation of Organic
Contaminants •
141
142
Acoustic Barrier Particulate Separator : • •
Air-Driven, In-S'rtu Remediation Technologies
Applications of Chemical Oxidation and Electrochemical Iron Generation for Removing Arsenic
and Heavy Metals from Water - v
Application of Full-Scale Soil/Sediment Washing for the U.S. Corps of Engineers & Toronto ;
Harbour Commissioners • ' '
144
145
Application of Sonotech's Cello Burners in Superfund Sites Cleanup Applications
Applications of Transferred and Non-transferred Plasma Torches in Hazardous Waste Treatment .146
!
Biological Removal of Perchloroethylene from Saturated Soils • •
Bioremediation of Cyclodiene Pesticide-Contaminated Soil
Bioventing PAH Contamination at the Reilly Tar and Chemical Corporation Site, the First Year
Results '.....
Capabilities of a Trailer-Mounted Debris Washing System Developed Under the SITE Program .. .
Combined Anaerobic In-Situ/Aerobic Ex-Situ Bioremediation of Chlorinated Ethenes Using an
Immobilized Cell Bioreactor
A Commercial Zero-Effluent Process for Utilization of the Acidic Waste Effluent from Titanium
Dioxide (T'O2) Pigment Plants to Produce a Chemical for Treatment of Waste Water and ,
Sewage
147
148
149
150
151
152
153
154
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The CROW™ Process for In Situ Treatment of Hazardous Waste Sites . , 155
CURE - Wastewater Treatment System . . . , .156
Development of a Gas-Phase Methanotrophic Bioreactor to Degrade Volatile Chlorinated Organic
Compounds • 157
Demonstration of Ambersorb® 563 Adsorbent Technology 158
Development of Fungal Composting Systems for Degradation of Polyaromatic Hydrocarbons
Associated with Manufactured Gas Plant Sites 159
Development of the UDRI Photothermal Detoxification Unit • • • • 160
Du Pont/Oberlin Microfiltration Technology (SITE) . .,.-...- 161
The ECO LOGIC Process - a Gas Phase Chemical Reduction Process for PCB Destruction 162
Electron Beam Treatment of Uncontrolled Hazardous Waste Leachate 163
Evaluation of Slurry-Phase Bioreactors for Treating PAH-Contaminated Soil 164
HRUBOUT® Thermal Oxidation Process 165
IGTs Novel Technologies for MGP Site Remediation . . . . 166
Innovative Bioslurty Treatment of Polynuclear Aromatic Hydrocarbons 167
Integration of Photocatalytic Oxidation with Air Stripping 168
In Situ Bioremediation Using Oxygen Microbubbles 169
In Situ Vitrification: Scope of Potential Applications 170
Low Temperature In-Situ Thermal Desorption of Organics from Soils . . 171
Photocatalytic Remediation of PCB-Contaminated Waters and Sediments 172
Photolysis/Biodegradation Treatment of PCB and PCDD/PCDF Contaminated Soils 173
Pneumatic Fracturing of Low Permeability Formations . . 174
The Reactor Filter System: Air Toxics Control for Soil Thermal Treatment Processes .......... 175
Reductive Photo-Dechlorination of Hazardous Wastes 176
Remediation of Chlorinated Volatile Organic Compounds in Groundwater Using the EnviroMetal
Process • ^77
Removal of Dissolved Heavy Metals Using Forager™ Sponge 178
Removal of Organics from Soils Using CF Systems® Solvent Extraction Technology 179
The Rochem DT Process 180
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SAREX® Chemical Fixation Process for Organic Contaminated Sludges and Soils 181
Site EOS: Removal of Heavy Metals with a Centrifugal Jig 182
Spouted Bed Reactor 183
Steam Enhanced Extraction for In Situ Soil and Ground Water Treatment 184
Sulchem Process - Destruction of Organics and Stabilization of Heavy Metals 185
The SWS® Bio-Sparging Technology ... 186
Terra-Kleen Solvent Extraction System for Contaminated Soil and Debris 187
Three-Phase Ruidized Bed Biological Waste Water Treatment System |. .. . 188
The Treatment of High Concentration Industrial NOx Waste Gas by Dry Method I .... 189
Treatment of Mixed Waste Contaminated Soil 190
Treatment of Wood-Preserving Waste by Lignin-Degrading Fungi 191
Treatment on Soils Contaminated with Heavy Metals and VOCs ; .. . 192
Two-Stage Fluidized-Bed/Cyclonic Agglomerating Combustor 193
The Ultrox® UV/Oxidation Process , 194
Use of Secondary Lead Smelters for the Recovery of Lead from Lead Contaminated Materials ... 195
Vitrification of Heavy Metal Contaminated Soils • . . . 196
Warren Spring Laboratory Soil Washing Process '..'.'... i ... 197
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RADIO FREQUENCY HEATING
Guggilam Sresty and Harsh Dev
III Research Institute, 10 W. 35th Street, Chicago, II 60616
Paul Carpenter
AL/EQW, USAF, Tyndall Air Force Base, Florida,; 32403
Clifton Blanchard
HALLIBURTON NUS Corporation, Oak Ridge, Tennessee 37830
INTRODUCTION
The in situ radio frequency (RF) heating process utilizes electromagnetic energy in the radio
frequency band to heat soil rapidly. The process can be used to heat the soil to a temperature range of
150-250 °C. The contaminants are vaporized and/or boiled out along with water vapor formed by the
boiling of native soil moisture. The gases and vapors formed upon heating the soil are recovered and
treated on site.
In situ heating is performed by energizing an array of electrodes emplaced in bore holes drilled
through the soil. The process can be used for the removal of organic chemicals which exhibit
reasonable vapor pressure (about 10 mm of Hg) in the treatment temperature range. The chemical
contaminants are removed from the soil as vapors along with steam and air.
The feasibility of the in situ RF soil decontamination process was first demonstrated for
petroleum hydrocarbons at a site of a jet fuel spill (1). In this field experiment approximately 500 cu. ft.
of sandy soil was heated to a temperature range of 150-160°C. It was desmonstrated that 94 to 99
percent of the aliphatic and aromatic hydrocarbons present in the spill site were removed (1). The
second demonstration, performed at Rocky Mountain Arsenal (RMA), showed that pesticides contained
in clayey soil can be thermally decomposed and removed. The total concentration of pesticides was
reduced from an initial value of about 5,000 ppm to>a final value of about 50 ppm (2). The third
demonstration was conducted at the Kelly AFB during the summer of 1993. A petroleum contaminated
site consisting of clay and cobble was successfully heated to the target tesmperature.
In various laboratory feasibility studies, the treatment conditions for the removal of the following
contaminants has been established: perchloroethylene and chlorobenzene from sandy soil (3), jet fuel
from clayey soil (4), PCBs from sandy/clayey soils (3,6), phenanthrene, pentachlorophenol and phenol
from sandy/clayey soils (5) and creosote from clayey soil (6). All of these studies except the one with
jet fuel and creosote were done with clean soils which were spiked with the contaminants in the
laboratory.
METHODOLOGY
The RF soil decontamination process heats an appropriate volume of soil in situ to temperatures
of 150° to 250°C by means of an electrode array inserted in bore holes drilled through the soil. Se-
lected electrodes are specially designed to permit the application of RF power while collecting vapors by
application of a vacuum down hole. Figure 1 is an artist's illustration of the process. The vapor
collection system is an integral part of the electrode array since vapor collection points are physically
integrated and embedded in the array. A vapor containment barrier is used to prevent fugitive
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emissions, and provides thermal insulation to prevent excessive cooling of the near surface zones.
Gases and vapors rising up to the heated soil surface are also collected at the surface by means of
horizontal collection lines placed below the vapor barrier. These lines are also connected to the vacuum
system. Power to the electrode array is provided by means of a power amplifier designed to generate
electromagnetic energy in the frequency range of 1 to 10 MHz. The actual frequency used depends
upon the volume and depth of the treated soil, and the dielectric properties of the soil. A power
transmission system is needed to provide power to the array. It consists of coaxial cables and a
matching network.
On-alta Vapor Recovery and Treatment
V
;.; Contaminated Soil •
Figure 1. Radio Frequency In Situ Heating Process
Prior laboratory and field experiments (1-9) have shown that high boiling contaminants can be
boiled out of the soil at much lower temperatures than their actual boiling point. This occurs due to two
reasons: first, the presence of an autogenously established steam sweep helps to improve vaporization
rate of such high boiling materials; second, the long residence time in situ permits significant removal,
albeit at a rate which is slower than that obtainable in above ground thermal treatment systems. Another
phenomenon which operates during in situ heating is the development of effective permeability to gas
flow. The increase in permeability is confined to the heated zone, thus creating a preferred path of gas
and vapor flow towards the soil surface.
There are several important advantages of the in situ RF soil decontamination process. These
are: true in situ treatment minimizes earth removal, excavation etc., thereby minimizing attendant
hazards related to odors, fugitive emissions and dust. Only 0.5 to 1 percent of the treated volume will
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require removal for the formation of the electrode bore holes. A concentrated gas stream containing air
Sr " Pr°dUCed WNCh ' "^ °" **
nm.Mt , "Rations of the process are: unable to treat metals, salts, and inorganic '''''.
pollutants; if large buned metal objects are present in portions of the treatment zone then the
applicability of the process may be limited to zones free of such objects. In its current state of
development the process is applicable for the treatment of a contiguous volume of soil extendina -
downward from the surface. Methods to heat selected layers of soil at depth are under development
RESULTS
Laboratory Studies
S,?VeTral laborat;ory treatab''lity studies on various types of soils and contaminants have been
?' f . were done to determine the optimum temperature and treatment time for
drfferent types of contaminants found m different soil types. The treatability studies have focussed on
chlorinated solvents volatHe aromatic hydrocarbons such as benzene, toluene, etc. (BTEX), petroleum
hydrocarbons (IPH), phenols, chlorinated biphenyls (RGBs), and polynudear aromatic hydrocarbons
The laboratory treatability studies showed that organic contaminants can be removed from soil
at temperatures that are considerably below the normal .boiling point of the pure contamSs A
summary of the treatability studies is published elsewhere (7). In most instances, it was possfcle , to
reduce the concentration of the contaminants by more than 90%. Temperatures of 200°C or more were
necessary to remove high boiling point compounds such as PAHs and Aroclor 1 242.
Field Experiment at Volk ANGB
r.,arH R m P8*01™*1 at a former *"« training pit located on Volk Air National
Guard Base (ANGB) in Camp Douglas, Wisconsin to show the feasibility of the in situ RF soil
decontamination process. In this field experiment 500 cu. ft. of sandy soil was heated to an average
depth of 7 fee . The area of the heated zone was 72 sq. ft. The soil in the site was approximately 98 %
sriica sand wh.ch had been contaminated with JP-4 jet fuel was spilled during routine fi°e training
exercises conducted at the site. The soil was heated to a temperature range of 150-160°C in
4 days ""* * ™ ™ ™ ^ S°UrCe' " WaS maintained **» treat™nt temperature
Numerous soil samples were obtained from the test volume and the soil in the immediate
surrounding v.cmity. Pre and post test soil samples were analyzed to determine the percentage
removal of the aliphatic and aromatic hydrocarbons present in the soil. It was shown that greater than
99 percent of the volatile hydrocarbons and 94 to 99 percent of the semivolatile hydrocarbons were
removed from the site. Hexadecane, with a normal boiling point of 289° C, was used as a tarqet
compound to represent the semivolatile aliphatic compounds. On an average 83. percent removal of
hexadecane was achieved. -
fl, ,-H A0"1"'"9- th! ^IT °f I'ff1,109' a tracer injection study was Performed to determine the flow of soil
5 and iSSSS 6y; 2f f? °f^Hal°121?2 (a 'iqUid at ambient temPerat^«) was injected at a depth of 6
ft, and at a distance of 4 ft outside the heated zone. The hot gases leaving the treatment zone were
sampled and analyzed for the presence of the tracer. The tracer was detected in the hot oases
approximately 100 minutes after the tracer was injected into the soil. , a,
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Soil samples obtained from the immediate surrounding vicinity of the heated zone indicated a
net loss of contaminants. Together with the results of the tracer study, it was concluded that no:net
outward migration of the contaminants occurred during the experiment.
Field Experiment at RMA
A second field experiment was successfully completed on Basin F soil at the Rocky Mountain
Arsenal. The pilot test demonstrated the ability of the RF heating technology to heat Basin F soil to over
250°C, and in the process reduce organochloro pesticide (OCP) concentrations near to or below
Preliminary Remediation Goals. Table 1 compares the removal of OCRs with two proposed remediation
goals. Aldrin and dieldrin achieved the irj4 biological worker goal, but not the 10 worker goal. Endrin
achieved both goals, but isodrin achieved neither. OCP destruction efficiencies in the soil heated to
250°C or higher were 97 to 99%, from initial concentrations which were up to 5,000 milligrams per
kilogram (mg/kg) (8).
Table 1 FINAL CONCENTRATIONS OF COMPOUNDS VERSUS SOILTEMPERATURE
Parameter
Aldrin
Dieldrin
OMMP
DMPA
TOC
200-250°C
Concentration
(mg/kg)
0.97
0.59
1.7
1.3
0.0034
0.13
2.1%
360
Standard
Deviation
1.0
0.35
2.0
.
0.0012
0.0
1.8%
520
250-300°C
Concentration
(mg/kg)
31
8.0
5.6
48
0.0028
0.022
3.4%
180
Standard
Deviation
40
8.0
5.3
62
0.0016
0.036
1.7%
110
>300°C
Concentration
(mg/kg)
1.8
1.1
' 1.0
49
0.0028
0.40
2.6%
110
Standard
Deviation
3.1
1.5
1.5
90
0.0019
O.B9
1.5%
25
Preliminary Remediation Goals
(4) :
10* Biological
Worker
(mg/kg)
56
40
17
3.6
••• -
-
-
-
10-1 Biological
Worker
(mg/kg)
0.56
0.40
17
3.6:
-
-
- :
The vapors produced during heating were treated in a vapor treatment system which removed
both the semi-volatile and volatile organic contaminants, and the condensate was stored for later
treatment and disposal.
A conceptual design has been prepared for treatment of Basin F by RF heating. [9] The cost is
complicated by the presence of a 5-ft deep clay cap. If this is considered to be contaminated, then it
must be treated. Furthermore basin F was divided into two zones, a deep zone (15 ft) and a shallow
zone (10 ft). The present worth cost to treat the shallow zones to 250°C was $43 million, or $110 per
ton of soil treated, or $221/ton of contaminated soil treated. The present worth cost for the deep zone
was $19 million, or $102/ton of soil treated, or $153/ton of contaminated soil treated. If the cap can be
scraped away before treatment, these costs will be less.
SITE Demonstration at Kelly AFB
An additional demonstration of the technology was conducted under the EPA SITE program at
Kelly AFB during the summer of 1993. Approximately 100 cubic yards of clayey soil-containing cobbles
and contaminated with petroleum fractions was heated to a depth of about 20 ft. Ground water level at
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pump water
REFERENCES
1.
2.
3.
4.
5.
6.
7'
Soil Decontamination
No. 83482402. June 1990
FOR MORE INFORMATION
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THERMAL DESORPTION OF COAL-TAR CONTAMINATED SOIL FROM MANUFACTURED GAS PLANTS
Neal A. Maxymillian
Stephen A. Warren
Clean Berkshires, Inc.
86 South Main Street
Lanesboro, MA 01237
(413) 499-9862
Edward F. Neuhauser
Niagara Mohawk Power Corporation
300 Erie Boulevard West
Syracuse, NY 13202
(315)428-3355
INTRODUCTION ;
Clean Berkshires, Inc. (CBI) conducted a full-scale demonstration test of its thermal desorption
technology on coal-tar contaminated soils as part of a Research and Development Program conducted
by Niagara Mohawk Power Corporation and supported by the EPA SITE program.
Niagara Mohawk is taking a proactive role in remediating its Manufactured Gasi Plant (MGP)
sites by experimenting with alternative technologies at the Harbor Point Site in Ut.ca NY CBI s
Thermal Desorption System (TDS) was chosen through national competition as the finrt technology to
be demonstrated. The TDS proved to be effective in remediating soils contaminated w.th poiynuclear
aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs) and cyanide.
THE CLEAN BERKSHIRES THERMAL DESORPTION SYSTEM ;
The Clean Berkshires transportable Thermal Desorption System (TDS) is based on rotary kiln
technology to decontaminate soils. The thermal treatment process involves two steps: volat,hzation of
oontamfnants followed by gas treatment. During the volatilization step, contammated materials are
exoosTdtchigh temperatures in a co-current flow rotary desorber, causing contaminants to volatilize
togas phase "The clean soils are then discharged and stockpiled for testing. The gas strearr.passe,, to
the downstream pollution control equipment, where contaminants are destroyed prior to release to the
atmosphere.
The TDS is a full-scale remediation system available for large commercial applications. The
system is of modular design and can be transported and mobilized on-site within two to three months.
Its compact design requires only a 100' x 150' footprint.
The TDS consists of a series of separate components, linked together and centrally controlled
by an operator in the process control room. The system includes of the following components:
• Computer controlled feed system '•
• Rotary kiln drum volatilizer
• Cyclone
• Afterburner
• Quench tower
• Baghouse
• ID fan and Exhaust Stack
• Multi-stage dust suppression system
• Process control room
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specific
Scru^-Vstemfortreatmentof
system n
temporary storage for the waste fee mTtenas
stockpl,e which has been taste, to determine
*"*
pr°vide
Ki.n.
where the Plant Operator controls the feed rTe
be,t that leads to the
scale, displayed in the Control Trailer,
Soil is fed from the incline conveyor belt intn the \c,\ .,
thermally transferred from the soil into the ^s stream Th I ;hW^ *" contamina"ts are
soils and contaminants are exposed to heat from the Hi r ThJSf.thtrmal transfer takes place as the
the Kiln. The Kiln burner can be fired with ehS No Tful, ? ™ ^^ 8t the feed end «'"
removal permits longer soil residence times « t o^timnm ! t°r °r natural 9as' Quick moisture
firing rate can be varied according to Sec^ "so!?SL£ ^^ i23''0" -?mPw«^^- The Ki.n burner
can support soil exit temperatures ranging fro^ = ' ^ ^ bumer
l-ne the Ki.n, providing for a wide ran/e o^ soil
The para^ ^^^^^ ** end to the discharge end;
med,a. Parallel flow also ensures that alf airborne dus nit ' <3XChange between the two
because they have traveled the length of Se K?n. *'* thiOrpu9h|V decontaminated
greater surface area to the hot gases fo proved volafi.izatSn T^" ? ^ ^ Which exP°ses
by the firing rate of the burner. Residence time te a^nS, /«, -1 <3XIt temPer*ure is controlled
of the Ki.n. Residence time may be vari££Tm le to ten m InC:"'ne an9'e "* r°tati°n Speed
des,red temperature exposure. Decontaminate 3 * 6nsure that soils achieve
0-scharge Cooler (SOC). The SOC is the first
«"« of speciany designed^
stream and a controlled volume of water Water ,^n J ^^ rem°Ved from the 0as
both cools the sol, and controls fug'.v^ ^dus? Soi "S ^f ^ ble"ded into the soil" which
and stored temporary prior to testing. ,^2,; %%&**%
^ .
negative pressure. Negative pressure prevents fud 1 ^ °? D^ Fan' °perates under
system to the atmosphere. Prevents fugitive em.ss.ons of gases and paniculate from the
lnto the
co.
Induced Draft Fan through
force
"" CVd°"e are drawn bV
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The Afterburner subjects the contaminated gases to very high temperatures to destroy the
contaminants entrained in the gas stream. The Afterburner is designed to achieve • 99.96 U
Destruction and Removal Efficiency (ORE). As in the Kiln, destruct.on of contammants m the
Afterburner is a factor of turbulence, temperature, and residence time. Turbulence is created by
fangent Sentry of the gases into the swirling flame of the Afterburner. This enhances the mixmg
S^TSSSd gases around the flame. Temperature and residence time of the gases are
control™ b ™e burner firing rate and the volume of air flow. A No. 2 fuel o.l or natural gas fired
burner generates the flame that produces the high temperatures for destroymg contammants m the
process gases. ;
Exit gas temperatures from the Afterburner can range from 1 400°F to 2000°F. At all
times the Afterburner operates at a temperature sufficiently high to destroy contammants in the
process gases Real-time data is monitored to ensure that adequate destruct.on takes place.
Gases are drawn by the Induced Draft Fan from the Afterburner through a refractory lined
duct to the Quench tower. The purpose of the Quench is to cool the process gases prior to
enter ng tne Baghouse. Gases pass through highly atomized water mists in the Quench. Cooling
the oases reduces their velocity, causes additional particulate drop out, and protects the Baghouse
Lexcessrve temperature. As in the Cyclone, particulate matter that drops out of the gas stream
"Se^SiTlJTsoharBed from the bottom of this component into the Mum-stage Dust
Suppression System. The gases continue through ductwork into the Baghouse.
The Baqhouse is a dry filtering device that consists of a series of fourteen compartments,
each of which contaTns forty eight Triloft filtering bags. Gases are drawn from the exterior surface
o? the bags to the nterior surface, leaving any remaining particles and dust on the outside surface
of he bags Particulate released from the bag cleaning process falls to the hopper auger and ,.
transported through a rotary air lock to the Multi-stage Dust Suppress.on System.
The Induced Draft Fan is the prime mover of gases through the system. Gases are pulled
emry point in the Kiln through to the Induced Draft Fan. Cooled contam.nant and
freezes are then forced out the exhaust stack. Exhaust stack ex.t temperatures
range from 300°F to 350°F. :
METHODOLOGY
The Demonstration included treating four waste streams from four separate areas of the
site, including: Coke Plant, Purifier Soils, Harbor Sediments and Water Gas Plant aoils.
from
and lead.
Contaminant levels for each of the source areas were as follows.
TABLET. CONTAMINANT LEVELS FOR SOURCE AREA WASTE STREAMS
Range of Contaminants
Waste Stream
~Coke Plant
Purifier Soils
Harbor Sediments
Water Gas Plant
"72.6 - 2089.6 ppm total PAH
205.2 - 1220.1 ppm total PAH
554.0 - 1879.4 ppm total PAH
1375.0 - 3321.6 ppm total PAH
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combining source materials.
and blending would assist in
Experimental testing, stack emissions samj no was expanded to inST® " T"1" ^ °*
volatile*, semi-volatiles, metals and partlculaS AdditSv^ ^ CB. sote^th?' 7 ^ ^
so that a Destruction and Removal Efficiency (ORE) could be' cafcu^ed " naphthalene
'" ^ TD3 at the best
RESULTS
CONCLUSIONS
streams found on this and other MGP sites
FOR MORE INFORMATION
NealMaxymillian
Clean Berkshires, Inc.
Ten Post Office Square, Suite 600S
Boston, MA 02109
(617) 695-9770
successfully process all waste
-------
TABLE 2. SUMMARY
OF TDS PARAMETERS AND RESULTS DURING THE HARBOR POINT DEMONSTRATION
==========
Run
MI imhpr
IMUlllUGI
..
CG-057
CG-058
CG-059
CG-060'
CG-076'
CG-077'
CG-078'
PS-061
PS-062
PS-063
PS-064
ps-oes'
PS-079'
PS-OSO'
PS-081'
HS-088
HS-089
HS-090
HS-091*
HS-092t
HS-093'
HS-094'
WG-084
WG-085
WG-086
WG-087*
wG-ogs*
WG-096*
WG-097*
Throughput
(tons /hour)
13tph
18tph
18 tph
12tph
15 tph
15 tph
15 tph
15 tph
15 tph
25 tph
25 tph
20 tph
20 tph
20 tph
20 tph
1 5 tph
1 5 tph
15 tph
17 tph
17 tph
17 tph
1 7 tph
14 tph
17 tph
1 8 tph
18 tph
18 tph
18 tph
18 tph
Soil Exit
Temperature*
600°F
600°F
550°F
600°F
600°F
600°F
600°F
600°F
700°F
600°F
550°F
800°F
850°F
850°F
850°F
600°F
700°F
800°F
750°F
750°F
750°F
750°F
700°F
800°F
850°F
800°F
800°F
800°F
800°F
— — =^====:
Moisture
Content*
15%
16%
13%
13%
18%
18%
19%
13%
18%
17%
17%
19%
22%
23%
25%
24%
24%
19%
28%
28%
26%
28%
21%
13%
16%
18%
30%
29%
26%
'
Infeed
Total PAH'
2089.55 ppm
539.30 ppm
478.79 ppm
443.11 ppm
98.10 ppm
99.90 ppm
72.80 ppm
749.46 ppm
825.88 ppm
772.73 ppm
'1220. 10 ppm
879.48 ppm
692.00 ppm
243.90 ppm
303.00 ppm
893.56 ppm
710.13 ppm
849.12 ppm
893.84 ppm
795.60 ppm
954.00 ppm
812.00 ppm
2261. 02 ppm
1770.70 ppm
2522.68 ppm
2427. 12 ppm
1375.00 ppm
1448.00 ppm
1610.00 ppm
========
Outfeed
Total PAH*
0.00 ppm
0.00 ppm
22.23 ppm
3.55 ppm
0.00 ppm
0.00 ppm
0.00 ppm
33.63 ppm
9.42 ppm
9.54 ppm
64.55 ppm
0.00 ppm
0.00 ppm
0.00 ppm
0.00 ppm
4.92 ppm
4.46 ppm
0.00 ppm
12.86 ppm
2.23 ppm
3.82 ppm
2.54 ppm
3.48 ppm
0.00 ppm
0.00 ppm
0.00 ppm
7.29 ppm
10.14 ppm
4.93 ppm
.
ORE1
99.9980%
99.9930%
99.9953%
99.9978%
99.9983%
99.9969%
99.9944%
99.9958%
99.9994%
99.9991%
99.9993%
99.9982%
99.9985%
99.7218%
99.9935%
99.9987%
_ . .- • ss
Waste Stream
Coke Plant
Experimental Phase
Formal Phase
Purifier Soils
Experimental Phase
Formal Phase
Harbor Sediments
Experimental Phase
Formal Phase
Water Gas
Experimental Phase
Formal Phase
« Afterburner exit temperature 1800° F.
/J*;r^
5 Calculated by TRC Environmental Consultants, Inc.
-------
INTRODUCTION
Douglas J. Hallett, Ph.D.
Kelvin R. Campbell, P.Eng.
ELI Eco Logic International Inc
143 Denms Street
Rockw°od-n Ontario, Canada
(519) 856-9591
.,
PROCESS CHEMISTRY
and
11
-------
Figure 1
ECO LOGIC PROCESS REACTIONS
H
ci ci
OO ->•
CI CI
PCB molecule & hydrogen react
2 O
+ 4 HCI
to produce benzene & hydrogen chloride.
CI
d^cr^ci
Dioxinmole * hydrogen react to produce benzene, hydrogen chloride * water.
3H
PAH
molecule & hydrogen react to produce benzene & ethylene.
+ 9 H2 —"~ 6 CH*
Benzene & hydrogen react to produce methane.
C2 H4 + Z n 2 *
Ethylene & hydrogen react to produce methane.
CnH(2n+2) - (n-DH2 n CH4
Hydrocarbons & hydrogen react to produce methane.
WATER SHIFT REACTION
CH4 + H20. •- CO + 3H2
Methane & water react to produce carbon monoxide & hydrogen.
12
-------
a sidest™ „, sc^r^S^orwrtc cortwiS** g»fj^ {{*>,&«» .
., Throughout wast* nm^.,, .. y yt'"-ra"on.
», „ _« i h*' ^-Ow t< LllfHSnfilri To i \e* r*f* 4._ _ . v«i iv* MI\JL*Co^ tiiriT™r\l n\/^4-«™« _ i j_t
. and the
The CIMS a]so
and stored
TESTING
13
-------
of 99.999«
stack emissions.
» second ^ of tests of
Jable
USEPA SITE PROGRAM RESULTS
Concentration
(mg/kg)
Desorption Efficiency
Concentration
(rag/kg)
II I 1 QIC I ^r====
14
-------
CURRENT STATUS
.
^
owners of
It can
Pr°Vide a
offer a
'
n'lectical
15
-------
Author: G. Edward Someus
La Raiderie, St. Peter Port, G^'™"
Tel: (44-481) 726 426 Fax: (44-481)
PCS PROCESS METHOLOGY AND TECHNOLOGY DESCR^ON:
THE PROBLEM: waste has no
The ,em, y
the gas-ISl p%™ sof »e organic and/or inonjanio matena,.
importance concerning this process.
CS^^^^^
sense that the technology starts » ™ '"SoseS d^ing, Rash Pyrolysis reactor, gas-vapour
^
Clean flue gas
Material charge
Water tretament
•VZater
Staarage
16
-------
entering £ pT/CheT" *, 'eSS 'ta 5 ™» « "
conient of (he waste from 45 % toless tha TheS, HV ""* °'°sed dryer lowere
-------
reactor rota.es aroundits symmetn,-
from each other.
The main features of the PCS Flash Pyrolysis reactor:
1.
2.
3.
4.
5.
6.
7.
SSasSsssK
Synchronised auxiliary installations.
medium.
The heat transfer contains three phases:
ground down to a maximum
permanently mixed, which mixing ^
material is to be permanently replaced by
conductivity of the ' 1
11
the reaclor body. The heated
and again. Therefore the thermal
d can be witnin a wider range. This is a
^n Son to the solid wastes which are usually bad
secondary. Radiation hea, Uansfer fnom the inner top surface otthe reactor body.
Tertian: Over the temperature of 275 -C (530 °F> an exothermic reaction starts durtng the
decomposition of the material.
lt is to be noted, that the basic
temperatures of 275 °C ^^'
process. Therefore the extended
*
vacuum control compensate the action.
i not result in an explosive
production of pyrolysis gas-vapours
and "» a*stable pemanert
thermal engineer design of thereaaor Is
and the extremely qualitative v^n^reSSpo™^ »« be separated at a certam
ftSS^^ cafbo" the material is to •" process p
1,boO°C(1,8500F). ;
18
-------
PCS PROCESS DEVELOPMENT STATUS:
Mmpounds
° "* "" PTOIUas-
A.
B.
C.
200
'nput -»» PW for lreatmen, of hospta, waste
PCS PROCESS PATENT STATUS:
wide:
PCS PROCESS PILOT PUNT:
no, measural),e
O.l2mo/m3
19
-------
PCS PROCESS LIMITATIONS: :
limited by the size of the PCS reactor.
PCS PROCESS APPLICATION:
, 15,000 ,ons,yea,
, 15,000 tons/year.
c. Waste
organjc nudear waste.
PCS PROCESS ECONOMY: tp
Amortiserings time:
RFSULTS AND CONCLUSIONS:
5 years
available reality, even far beyond the
Oon*s,ons: CDs* advanced
on
(decentralised waste management
FOR MORE INFORMATION:
20
-------
A.G. Seech, s.M. Burwell, |.j. Marvan, P.
INTRODUCTION
TECHNOLOGY DESCRIPTION
21
-------
PILOT SCALE DEMONSTRATIONS :
Wood Treatment Soils ,
ou
— : r;
» was
and homogenized by tilling. The
whloh may
-------
to
u>
I
i
to
E3J
o »
•n
CO
S
Concentration (mg PAH/kg)
S! 2.
3 a
Concentration (mgchlorophenols/kg)
rr co
3 CD 0) CD O
3 & S § -
§CQ o Sg
^ CD 0) CD 3
"cfs-
S S
I§
~;- —K
S o
' CD =r
_. Q. CD
rr co T3
CD O =
D
m
to
Q.
w"
§ s
Q-co
CD CO
S^
3 o^
5 O"
—y
0) o
Q. tu
w CD"
§|
S? o
35
£o
, §
lu ' 55 w »
o g a{?«
c?«" cT c
tu o ~* cr
i^S 8'
r-t
S
CO
I
CD
"If
CO
CD
CD
Q. CD
CQ jf
CD C5
CD CD a ^
1^1^
P CD ^ tt
CO
CD
CD cr
CQ
a>
—' — w 3 =•
3* CO J J
f|8ff
of
-------
Figure 3:
Cluysene
Btnzo(b)fluoranthene
zssssssssssas
-
Sediment- Hx-Situ Application
Thls Pi,o, sca,e demonstration ds
De
monstration. Ex-SItu and In^u, Applications
SITE demonstration program.
24
-------
1,400
Figure 4:
during
COMMERC/AL SITES
^
25
-------
Dane Higdem
J R. Simplot Company
P.O. Box 91 2
Pocatello, Idaho 83201
(208)234-5367
INTRODUCTION _ process was deve,oped
'
Degrades the dinoseb ^^JSTSwr. RDX and HMX.
effective on other mtroaromat.es such dearadation of dinoseb. This
METHODOLOGY -th aaitation and monitoring equipment.
with minimai effort. mnor^ure The pH range for
"
bioreactor.
During treatability
-
26
-------
-
RESULTS
prooess,
2)
3)
4)
5)
6)
7}
-a--.
-S
27
-------
«. specific and will need ,o be determined by ,rea,ab,«ty Sadies. ^^^ ^
The Simplot process is a cost effective alternative to ot er pro ^^ ^ particulates during
28
-------
ms£le*k^^^
^^^^^
, JSd™*y^^
GOLDBEKHAII.Q
Postfach 104629
20032 Hamburg
_. Germany
Phone:(-f+
INTRODUCTION
The Remediation Site
THE CONTAMINATION
produato"
facility the contaminants
are we/I
1.
2.
3.
Phenol
Methylated Phenols
Dimethylphenol
29
-------
Legal Standard I oxicty
Substance lwf*
Solubility
350 mg/
oo mg/
130mg/i
5rng/l
15 mg/l
10 mg/l
Dimethylpnenoi
toxicity to humans (nervous and
site and a high standard
RESULTS OF SITE EVALUATION
the factory. chemical weapons. Prior to
BIOLOGICAL DEGRADATION STUDIES
TheoplmUro
25° C.
30 '
-------
comaminants are detected by HPLC -
analysis.
used
to DIN
KOH
TECHNICAL CONCEPTION
and m0s,
a
.
A so ca«ed preve^er is mounted onto the concrete ,ayer
'ing, clean
Right after this process
"'
Handling and Transport of Sluny
Removal and Transportation in Numbers
contaminated soil
surface of
contaminated soil
maximum depth
maximum concentration
number of drilling units
number of vaccum units
number of barches
holding capacity
begin/end of operation
average production
31
14,800 cubic yards
1,400 sqft.
59 ft
63,000 mg/kg phenolic substances
2
3
4
98 cubic yards
7/28/92-10/27/93
112 cubic yards/clay
-------
maximum production
distance from remediation
site to external treatment site
number of transports
234 cubic yards/day
11 miles
426
EXTERNAL TREATMENT
s«4SS^^
the required security, rnui iu 3
fractions listed as follows:
with
Material
gravel 2-8 mm
target value is
reached
sieve with flushing
device
screw classifier
derrick-machine
fine sand
150 urn - 500 |im
landfarming
with inoculation
belt press
bioreactor
organics and minerals
63 urn-100
neutralisation
inoculation of
adapted micro-
organisms
water, organics
and minerals < 63 urn
EXTERNAL TREATMENT IN NUMBERS
area of treatment facility:
machinery:
landfarming area
Infrastructure
total
1,568sq.yd
4,312 sq.yd
392 sq.yd
6,272 sq.yd
electrical installation
personnel:
195 kw
5
32
-------
COSTS
transportation
DM 80.00 per m3 (~ (JS$ 45
separation/biological
treatment
DM 200.00 per m3 (~ US$ 115.00)
DM 30.00 per m3 (~ US$ 18.00)
workers protection fees
(according to German
guide line 2H 1/183)
recycling of
treated material
DM 25.00 per m3 (~ US$ 14.
CONCLUSIONS:
^
* fu» biological clean-ups;
• 100% recycling of treated material;
**. „, Qaseous mn^ants i
in
and a
33
-------
Processwater
2500 cbm
flocculaiion
cleaning purposes
filter cake
(organic) /
36001 ^
conc.<5mg/kg
Mass balance
(external treatment)
stony input
0-8 mm solids
water
22.500 cbm
av.conc.2500mg/kg
waste water
15.000 cbm
cone. <20 mg/1
Gravel
V 2-8 mm
23001 ;
/ conc.<20mg/kg
Sand /fine-sand
3400 1
conc.<20mg/kg
34
-------
, USA,
+49(7021)861293
K"-chheim/Teck, Germany, Tel.,
INTRODUCTION
uenoeo(a-----^^
;'
•n situ bioremediation can h -Ump ln the we" c*sing Thus
as a by.product S^S^^1^^ '"^sed wfthne^8
cannot drop producing new Slim,9 r°Undwater bX We same strippi
especially when they are fou?d in T °the™ise- For hydrocarbons
The contaminated wate^ enter h P S' 3 downward ope °
the well through S,^^ JT" -^h the uppt
. activated carbon or
UVB can be
°f «V9f" supplied^
oro tS' Carb°n
h $' S° the pH'a
"" W3ter (LNAPL>-
"
occur the
ad
C0ntamin^ts in the ofl ^ ^ a S ed,groundwa^r leaves
or
or to i
-in the we,, casing
"
35
-------
activated carbon
activated carbon
I fresh air
ventilator
Dripping zone
.air introduction
resting water level
soil air removed vo
;tion (optional I
working water level
purrp to support
the water flow
Figure 1.
stripping zone
air introduction
working water level
•gating water level
groundwater circulation
'aquifer bottom
UVB technics combining in, *, strippin,3 and ^^^S^M^
8 XSSESrS^ 23--n. * **- «• p—••nilrate
UVB
Figure 2
RESULTS
1- BTEX and Mineral Oil in Berlin, Germany
36
-------
aquifer ha<= a «;• , m> gray clayey marls mak* „« - nes form intermittent
TWO I A/R o'wvc'i is U,2.
data of removed hydrocarbonT" ^»"9\UpStream from "VB , '" September
values '"
are
a
the entire aquifer thickness and n(,ydrOCarbons' on'y dissolved in n JVBj5ystem) were found
3as co.8ntr °
,he inltia, 474 days of
mon"°"n9
P'Ume <3 m fr™ * WB S h" '"K"" """"tralton
^
37
-------
measured results.
Cases: Pilot test for pesticides in Germany
: Po es
-
during the pilot test.
' -" -
rtthebtowme. been installed within the casing
REFERENCES
1.
173-195.
38
-------
2.
3.
pp. 56.80.
Sick, M Alesi E J
(«,.,. Alr Sparging^ ?Sshers e'ooa
39
-------
R. Donald Rigger
.,.
345 Courtland Street, m
Atlanta, ^°*9%a 3°365
(404) 347-3931
INTRODUCTION _ excavation and on-site
« tne Basket CreaK Surface ^P-V^arund rLoval program
areVare as follows:
Mercury
Trichloroethylene
isobutyl Ketone
Ethyl Ketone
390
9,400
8,600
220,000
66,000
23,000
40
-------
METHODOLOGY
« - »* to
temperature thermal desertion v?P°f .ext««lon and low
i :ss :s\ssjrsi -f? as, Fr™ •"- rg™
the
development of an air ha^^n •
exhausting a sufficient m ?? system capa.ble of
a safe
- installation of an
to remove
41
-------
extraction system an 8,000 cfm induced draft
exhausting the building *ir/* ^stream and duct work tOj
removing particulate from the air J«e™pacity thermal oxidizer
the culminated air stream.
In October of ^-^^^T
conjunction with a trial burn on the tnerm ^ soil was
3 SS cScLd the
'aiIB
ss=i
basis. Mass
and dioxin/furan and reported to
-
rates were
jt for Toxic Substances
Agency ^ ^
oxidiZer would not pose a
threat to public health.
the air handling system and *°u^2 ^"/oxidized at 1,600
the thermal oxidizer where the VOCB »|r«2x ne contaminated soil
degrees F. After a grid
cona
were collected. If
.
These horizontal vapor extraction weiis ^ building.
Sot sections of well screen.
The controls put in place tc >
preventing off-site exposur eJQ °r^r^?c|i safety concern was the
L-site worker safety. ^^^Itmosphere within the^
potential to develop an exPi°°x^5acticai to eliminate all
Enclosure. Because it was not practical^ hasis was placed on
ignition sources infj^.^ethe concentration of combustible gas.
controlling and *°n^oring the ^ ± of VOCs in the air was
The key to controlling the G°^JJ the VOCs as they were
42
-------
of vpcs. Additionaily,
were
w
Indicator was used to monlto?
gas in the airspace A Jtalt of
Combustible Gas
°f
of
inside
for
explosive atmosphere n thS evs°P an
and outside thePenclosure
all components of the air
exaction piping,
RESULTS
can be virtually eliminated. from VOC contaminated sites
Phase of the project
the former impoundmen X ? removed
^
to 80% of the VOC removal took SMS ^Si1;; ^^
extraction system. The remain *?i , stockPile vapor
liberated during the excava?toi? ;emoval consisted of VOCs
All of the reco^erel VOCs were rSSpS*?*^1" ?andlin5 Processes.
treatment. The vapor exL^T^^? tO the thermal oxidizer for
weeks after excavation m^mi^ ^ waf .°Pe^ted for three
soil then demonstrate^ St S SJl wf^11?5 °f the st°°kpiled
waste and it was subsequently disposed of n° J°n?er a regulated
cost. VOC removal during excavation«nS • f:Slte at mini™al
system resulted in tota^vSs In Jhe sSf J ^ ^he VaS°r extraction
approximately 30 ,000 ppm to leS thL SjJ p|m?5 raduced from
n caf bToSStSjiSS0^ ^ tO cl— ^rate that
handling soil contaminated SiS^iiSinS;^^ • f:cavatin* ™*
A rigorous air monitoring and saSni fS! iy ^olatile contaminants
to evaluate the effectiveness Sfthe fua??i^01 was . implemented
system. Based on the fact
43
-------
and 400 ppm.
CONCLUSIONS
SS5t
of scale were encountered.
The fact that uncontrolled hazardous waste sites pose a
44
-------
WOLFGANG P.W. SPYRA
Abstract
• Developing and testing protective equipment
- Experiments in the field of detoxification
' Developing and testing chemical warfare aaente
-I^SX^^^^^
• Laboration of munition
•«* could be there fc tear gas, stemu|ators
s:
bottte-
— - to be remida,, A recovery
head to be classifid Into 3 remediate i calories C°Very strate» "azardons situatS
Before starting ,h9 remldialion procedure differen, prelnves,igat|ons
- Ferromagnetic investigations
- Evaluation of pictures of the British Royal Air Force
- Test of soil for toxic substances, etc.
to identify potential areas of danger.
-** ••
"-*"1 **
•» ""am lterature on chemlca,
compared «o the hazards to which
45
-------
^
^
traffic junS of both the public transportation and the ,nd.v,dual traff .c.
The size of this danger area is determined by the hazard. The following criteria are applied to determe
the degree of hazardousness:
-released amount of chemical warfare agent ,
- dangerousness of the relcared chemical warfare agent
- how was the agent released ,
- weather conditions
- effective protective measures
the degree of protection we found suitable
200gTabun
200 g Hydrocyanic acid
500 g Phosgene
The recovery of chemical warfare agents principally bears the risk of selling free these highly toxic
Thus* S? measures are devised in a way to ensure that
£ source of the harmful substance is tg be seated imrnsdeately, and
- the released warfare agent is bond. ;
The used recovery techniques varied from mechanical procedures to the treatment of archeology
finds.
sasrJr^JKssssawaft
consideration and aspect of on - the - job safety.
time a temperature higher than their interior body temperatur of 38 Grad Celsius.
considers also socio-political and social aspects.
be used agSS to be assumed that future recovery project will qpst much more less.
46
-------
47
-------
Janusz Licki
institute of Atomic Energy, Otwock-Swierk, Poland
Michal Romanowski
DO Proatom, Warszawa, Poland
INTRODUCTION
The hazardous wastes in the
Especially harmful for a n»" and
. no doubt,
NOX emitted during fossile fuels
Poland, where coal is mostly used as a
and NOX annualy. The above numbers
oooJSTR^ ed n
or air stripping) contain these compounds as well.
Qf these poi)utants ; the waste
h-rd°us — emitted mav reach thouse
. reach 4 and 1 .5 million tons
- respectively.
gre vo,atjle organic
the USA
reLdiation of soil of 9round water
PROCESS DESCRIPTION
An electron beam accelerator is . * I «- -Process
are
nitrate) are then collected and "sed as a
The process has been successfuly
[1,2,3,41, waste incinerator (S02, NOX ,
and so'il remedition off-gases (VOQ [6,7]. treatment is in operation in Poland
The biggest industrial plant for elect ?" £earntiua Q % f of SQ and 80%
treatment at power plants (SO,, NOXI
?,unnels (NOx ) 15! and other industnal
The scheme of industrial pilot plant is given
48
-------
\ • ? »n '
------L. yj
Figure 1
Scheme of industrial pilot plant.
49
-------
EB/MW COMBINED PROCESS
The experiments, set up for invest*.
has been built on the base of electron
to investigate a combined
energy to produce cold plasma '"
The reaction vessel
axially. The ^^
It passes titanium foil window. More tnen
Inder. The microwave streams are propagated
perpendicuiarly to the axis of the vessel.
^. energy is concentrated in
stream Qf the gs are
or can ,
orbicularly.
The prehmtw
efficienc.es of the
this combined method
. possible to find such condition with, where the
simu,taneous use the electron beam and
K 0fYthe removal process to compare with
°btain the technical and economical advantaaes
of gaseous, liquid and solid hazardous
forms (aerosol).
INDUSTRIAL PLANT DESIGN
Banned industrfa, p^an, wi,, be cons,™^ a
irradiation principle.
CONCLUSIONS
-------
Figure 2
Scheme of industrial demonstration plant.
51
-------
REFERENCES
1 . S. Machi, 0. Tokunaga et a., Radiat.Phys.Chem., 9, 371-388 (1977).
2. N. Frank, W. Kawamura, G. Miller; Radiat.Phys.Chem., 25(1-3), 35-45
(1985).
3. H.R. Paur, S. Jordan; Radiat.Phys.Chem, 31(1-3), 9-13 (1988).
7 7imek- Applications of Isotopes and
. SM-325,1 24, ,AEA,
Vienna, 1992.
^
Germany, 1992, SM-325/1 16.
6. H.R. Paur, H. Matzing; Rad.Phys.Chem., 42(4-6), 719-722, 1993.
7. S.M. Mathews et a., Rad.Phys.Chem., 42(4-6), 689-693 (1993).
8 A.G. Chmielewski, E. Iller, Z. Zimek, J. Licki; Rad.Phys.Chem.,
40(4), 321-325 (1992).
52
-------
INSTALLATION FOR SEWAGE SLUDGE HYGIENIZATION BY ELECTRON BEAM APPLICATION
A.G. Chmielewski, Z. Zimek, T. Bryi-Sandelewska
Institute of Nuclear Chemistry and Technology, Dorodna 16,
03-195 Warsaw, Poland .
A. Kubera
Swea-System, Warsaw ,
L Kalisz, M. Kazmierczuk
Institute of Environmental Protection, Warsaw
INTRODUCTION
Many kinds of hazardous wastes are presently produced by men and environmental
pollution has become more and more serious problem in industrialized countries. Different
methods of disposing or recycling must be applied depending on the specifity of the wastes, for
instance, chemical wastes from industry, agricultural wastes from big farms, biological wastes
from sewage treatment plants, hospitals and international airport. In some cases combustion is
the only safe method of neutralization, however, recycling of wastes after specific treatment is
usually considered as the best method of their disposal.
The main danger caused by hospital, airport and sewage treatment plant is sanitary one.
All methods of destroying microorganisms and parasites (and their eggs) may be suitable for the
elimination of that danger. In some cases hazardous wastes of organic origin make the problem,
too.A lot of investigations have been done to solve the .problem of wastes. It appears that
irradiation is one of the methods of treatment which makes the wasteis harmless and enables
their recycling (1-3, and references therein).
Sludges collected in municipal sewage treatment plant contain organic and inorganic
components valuable for the agriculture, and their beneficial use is passible but after effective
hygienization. Investigations performed in many countries show conslusively that sewage
sludges not overcharged much by heavy metals, while treated with gamma rays or electron
beam (EB) are sanitary safe and can be used with good result as soil fertilizer.
GENERAL OUTLINE OF THE PROCESS
Experiments which have been performed in our Institutes proved that irradiation with 10
MeV EB decreases bacteria content in the sludges to the safe level (including Mycrobacterium
tuberculosis) and kills all parasites and their ova.
Preliminary tests on the effect of EB treated sludges on the growth and yield of vegetables
in pot cultures showed significant positive effect of sludge addition compared to plants grown
on untreated soil.
On the basis of experiments mentioned above the installation has been designed for the
sewage station in Polish city Otwock. Scheme of installation for sewage sludge hygienization
with electron beam, and vertical and horizontal projection of radiation processing unit are shown
on figures 1 and 2, respectively. Dewatered sludges (containing about 30% of dry metter) are
spreaded on the transporter and disinfected by electron irradiation with a dose of 5 kGy.
Capacity of the installation is 70 tons of sludges (day what corresponds to about 48000 m ) day
of sewage. Capital costs of irradiation processing unit is 4.0 million US dollars, what mainly
depends on the cost of accelerator and its building.
53
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E
co
0)
.Q
O
SLUDGE
.FERMENTATION
CHAMBER
SLUDGE
RETENTION
TANK
MECHANICAL DEWATERED
DEWATERING SLUDGE
STATION WAREHOUSE
ELECTRON
ACCELERATOR
CHAMBER
c
O
TO
N
ra
0)
01
D)
(D
Q)
CO
O
co
•M
CO
o
0}
E
03
jr
o
-------
B
Figure 2
Radiation processing unit.A-vertica! projection, B-horizontal projection
1-electron accelerator, 2-conveyor, 3-shielding walls, 4-dewatered sewage sludges feeder.
55
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Hygienized with EB sewage sludges can be spreaded on the soil (as fertilizer) immediately
after leaving the installation and no place for long storage of these sludges is needed, in the
contrary to conventional methods applied recently in sewage stations.
RADIATION PROCESSING UNIT
Construction and equipment costs:
- dewatered sludge warehouse
- centrifugal machine
- building for accelerator and auxiliary equipment
- electron accelerator of 10 MeV, 15 kW
- water cooling system (closed cycle)
- disinfected sludge warehouse
- conveyors
- roads, squares, illumination
Plant parameters:
- building area
- usable area
- cubature
- power installed
- water consumption
Manpower:
- one shift operation
- two shift operation
Performance:
- capacity of communal liquid waste
- capacity of dewatered sludges
- dose
- two shift operation
REFERENCES
0.4 Mio USD
0.15
1.6
1.0
0.2
0.15
0.3
0.2
752 m2
1150 m2
7000 m3
300 kW
0.3 m3 /day
7.persons
12 persons
48000 m3 /day
70 t/day
5kGy
3840 h/year
1. Swinwood, J., Sludge Recycling with Irradiation-Disinfection. Paper
presented at 4th Nordion Gamma Processing Seminar, May 26-31, 1991.
2. Marconi, E., Aoude D., Kuntz, F., Trescher, J.S., Wild, F.,
Schmitt, M.P., Bientz, M., and Hasselmann, C. Hospital Wastes
Sterilization with an Electron Beam Accelerator. Paper presented on
International Symposium on Application of Isotopes and Radiation in
Conservation of the Environment, Karlsruhe, Germany, March 9-13, 1992.
3. Cooper, W., Nickelsen, M.G., Meacnam, D.E. and Cadavid, E.M, High
Energy Electron Beam Irradiation: An Innowative Process for the
Treatment of Aqueous Based Organic Hazardous Wastes. J.Environ. Sci.
Health, A27/1/, 219-244, 1992 .
56
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SOIL WASHING. FROM CHARACTERIZATION TO TAILOR-MADE FLOW
DIAGRAMS. RESULTS OF FULL-SCALE INSTALLATIONS
MARC F. PRUIJN
Heidemij Realisatie BV, P.O.BOX 660, 5140 AR Waalwijk, The Netherlands, tel. 31-416044044
1. INTRODUCTION
The principle of soil washing technology is to concentrate the contaminants in a small residual fraction
by separation. The soil is mixed with water into a slurry and then several separation/classification-
technologies are used to remove the contaminants such as screening, hydrocycloning, gravity separation and
froth flotation. The sand product can be reused, the residue has to be landfilled or treated. Soil washing is
applicable to a wide variety of contaminations such as heavy metals, Polycyclic Aromatic Hydrocarbons
(PAH), mineral oils, pesticides, cyanides and others.
The objectives of soil washing are two fold. The first is to decrease the level of the concentration of
contaminant. The second is to decrease the quantity of the concentrated residue,, Often these two objectives
interfere. Adding an extra separation step will create more residue, not adding a step means a higher
concentration of contaminant in the product.
In designing a soil washing process it is important to understand in what form the contaminant is present
within the contaminated soil. This characterization is the key to find an optimum in the two objectives; the
lowest concentration of contaminant in the product and a minimal quantity of residue.
2. METHODOLOGY
The characterizing of contaminated soil consists of a characterization of the contaminant and a
characterization of the soil. In the dutch legislation the standards for the contaminants are made referring to
their chemical form (like benzo(a)pyrene) or to then- absolute concentration (like total lead). The physical
form in which the contaminant occurs within the soil is still not clear when the concentration is known.
Determination of this physical form is the objective of the characterization.
2.1. Contaminant-characterization
In general there are four main physical forms in which a contaminant can occur in the soil.
- Partiples that have a high concentration of contaminant. These particles can be pure contaminant, like
lead-dust or pesticide pellets, or not pure, like tar particles or slags.
- Coatings of contaminants on the sand particles.
An example is the lead-coating that often is found on shooting range sand.
- Water soluble components. Since soil contains 10-20 % of water, the pollution of the water will also pollute
the soil. Phenol is a good example for this type of contaminant, but also some metal-salts are soluble enough
to give significant soil contamination.
- Contaminants that adsorb to the soil. Adsorption is possible whenever the contaminant is (slightly) water
soluble. From the water phase the contaminant adsorbs to a place with a higher binding energy. In this way
the contaminant can migrate from one soil fraction to another. Almost all contaminants show this
adsorption-behaviour. Very often absorption takes place onto the fine clay-fraction and onto organic"
material.
The actual contamination in a soil is often a combination of more characterbation-types. All kinds of
contaminants occur in the soil, and every contaminant can have different occurrence. The first step for a
proper characterization consists of evaluation of the historical information available concerning the source of
the contamination. Examples for common sources are: chemical industry-calamities and spillage, gasoline-
station-spillage, use of slag-material in road-construction, hunting and waste-dumping. After the initial
contamination of the soil, the physical occurrence of the contaminant can and can change, for example
because of the adsorption-processes.
The above mentioned historical analysis gives a prediction in what physical form the contaminants are
present but needs to be confirmed by soil characterization. This physical and chemical analysis includes wet
screening, Scanning Electron Microscopy (SEM), stereomicroscope, density separation and absolute
chemical analyses. , .
As an example the physical and chemical form of some contaminations are related to the four
characterization-types in table 1.
TABLE 1. SOME EXAMPLES OF DIFFERENT PHYSICAL OCCURRENCE OF THE SAME CONTAMINANT
Particles
Coating
Hater
Adsorbed
Lead
Benzo(a)pyrene
Arseni c
dust
slags
fungicide powder
shooting range sand leadchloride
tars low cone.
as complexes
at clay
at clay
organic mat.
57
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2.2. Soil-characterization
The characterization of the soil is very straight-forward. Important factors are the particle size
distribution, the organic matter content and the calciumcarbonate content.
This physical characterization is important for the amount of residue that the process will generate. Also a
large content of certain fractions like the sludge, the organic matter or the oversize can cause operating
problems in the process.
2.3. Conclusion ,...,. • <• - • •
A combination of the soil- and the contaminant characterization is the best starting point for developing
a successful soil washing process. The effort that is put into the characterization phase will result in lower
concentrations contaminant in the clean sand product, lower production costs and lower quantities of resi-
due. This way the environmental and the commercial efficiencies are optimized. Heidemij has a large
experience in translating the characterization to a real-scale soil washing process. The translation-path is
visualised in figure 1.
Laboratory
Piloting
Full-scale
(Characterization) (Upscaling) (Production)
FIGURE 1. Linking characterization and full-scale soil washing.
3. RESULTS
3.1. Introduction
In each case study presented, the characterization results as well as the actual process used are
explained. The projects are realised with a capacity that varies between 15 and 40 tonnes/hour. The product
sand in all projects was reused. The residual sludge and oversize are landfilled or treated with other
Special attention is paid to the contamination level of the soil before and after soil washing. The
efficiency for each component is presented. These efficiencies are, of course, only valid in relation with the
described project.
3.2. Case studies
3.2.1. Case study 1. ,.,.,... L i jm j
Characterization. In this case study the soil was contaminated with dredged sediment that was landhlled.
The sediment was contaminated with cadmium coming from industrial activities, metallurgical as well as
phosphate-processing. The concentration of cadmium was 8-18 ppm.
The relation between particle size and contaminant-concentration is shown La Fig 2. This figure was
assembled from concentration analysis data derived from samples with a different content of fines.
Concentration cadmium in ppm
0 S 10 15 20 25 30 35 4O 45 50 56 60
Fraction < 63 micron in %
FIGURE 2. Relation fines content and cadmium-concentration for case study 1.
There is a clear relation between fines-content (defined as fraction smaller then 63 u.m) and cadmium-
concentration. In this case the contaminant appears to be associated only with the fines.
The cadmium might be readsorbed to the fine particles. ;
Process. The soil was wet screened to separate the coarse particles (clay lumps, gravel, waste material).
:er wet screening the fines were separated from the sand fraction using hydrocyclones. The fines were
After •
removed almost completely. The sand product was reused at a residual cadmium concentration of 0.4 - 0.8
ppm (removal efficiency approx. 95%). Figure 3 shows the schematic flow diagram.
58
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— Clean sand
Oversize Sludge
FIGURE 3. Schematic flow diagram case study 1.
3.2.2. Case study 2.
Characterization. Shooting at clay-doves with lead-pellets (usually 1,1-1.3 mm) contaminated surface soils
over a large area. The top-layer of the soil was contaminated'with lead shot, but the pellets also leached out
due to acid rain. The leachate readsorbed to the soil, specifically to the clay fraction and the organic matter
The pellets also disintegrated due to mechanical forces and corrosion. Therefore also lead-slices with a '
diameter smaller then 1.0 mm were found. Figure 4 shows the relation between lead-content and particle
size. In the plus 1,000 u,m fractions the lead content varied between 5,000 ppm and 200,000 ppm. Higher
concentrations than 5,000 ppm are not presented hi the graph.
Concentration lead in ppm (Thousands)
O'M 30-U 3W< U-tH Uft-HO MO-400 BOO-WOO >1OCO
Particle oiza fraction in micron
FIGURE 4. Distribution of lead over the size fractions.
The lowest concentration of lead is found in the 63-600 p-m fraction, which is also the main soil size
fraction.
Pr°cess. The soil with an input lead concentration of 1,000-5,000 ppm was first wet screened to remove
oversize material. In a next screening step the soil was screened at 600 jun to remove the lead pellets. The
clay fraction was separated by use of hydrocyclones. The remaining soil was scrubbed and leached with
slightly acidic solution and finally dewatered. The sand product contained 50-60 ppm lead (removal
efficiency approx. 98%).
The schematic flow diagram is presented in figure 5.
— Clean sand
Contaminated —
soil
Wet
screening
Wet
screening
Hydro
eye Ion ing
—
Acid
scrubbing
1
Oversize Lead-pellets Sludge
FIGURE 5. Schematic flow diagram case study 2.
3.2.3 . Case study 3.
Characterizaripn. The historical analysis of this case study showed that the soil was contaminated with
slag-residue produced from metallurgical industrial activities. The slag material was easily visible in the soil
and appeared to be lighter than sand. They were also disintegrated and leached-out to the groundwater.
Soil samples were wet screened and in the different size-fractions the contamination-content was
analyzed. There turned out to be a clear correlation between the three contaminants. This indicates that the
characterization of the three different contaminants are the same, except for the fines, where the relation
was different probably due to different solubilities of the metal-salts. The results are shown in figure 6.
59
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Zinc and lead Concentration In ppm Cadmium
3000 —~"~~ZIZIIZZIZZZZ
•i ZlM HZ Laid ~ Cadmium <
tfca—,
0-fO 20-« ea-fM 2W-«0 600-10001000-4000 MOOO
Pvtlde *iza fraction In micron
FIGURE 6. Relation cadmium, lead and zinc content as a function of particle size.
The sand fraction (38-2,000 (un) was analyzed with Scanning Electron Microscopical analysis to identify
the physical form of the heavy metal contaminants present. The condensed results of this analyses are shown
in table 2.
TABLE 2. ELEMENTAL COMPOSITION OF CONTAMINANTS AS IDENTIFIED BY SEM-ANALYSIS.
Elemental analysis
Mineralogical description
Zn. Si, (Fe, K. Al)
Zn. C, (Ca, Al, Si, Fe, Pb)
Zn. 0, Si
Zn. Pb. Al, Si
Zn, S. Si, 0
Pb, S
Zn, S
Zn on silicate matrix
Zn on organic matrix
pure ZnO with Si
Zn/Pb on Al /Si -matrix
Zn-sulfide on SiOz matrix
Pb-sulfide
Zn-sulfide
It was frequently found that zinc and lead contaminants were present in the form of different discrete
particles in a "free" form or attached to organic (slag) material. From the mineralogical analysis it appeared
that a great variety of zinc and lead containing compounds were present.
The presence of non-discrete zinc and lead within slag particles could not be detected by the SEM-
analysis technique but chemical analysis showed that these slag particles also contained high concentrations
zinc and lead in their structure.
The great variety of mineralogical forms in which zinc and lead were found is typical for thermal
processes that produce slag materials and can be directly related to the original source of the contamination:
pyro-metallurgical industrial processes.
Process. The soil was screened to remove oversize material and large slag-particles. Hydrocyclones were
used to remove the fine particles. The low-density slag-particles were removed by gravity separation, other
slag-particles were removed by froth-flotation. The concentration of the contaminants are listed hi table 3.
Figure 7 shows the flow diagram.
TABLE 3. CONTAMINATION LEVELS IN PPM OF INPUT AND OUTPUT OF CASE STUDY 3.
Input
Output
Efficiency (%)
Lead
140-611
60
57-90
Cadmium
5-17
1.3
74-92
Zinc
640-2822
200
69-93
Contaminated —
soil
Met
screening
Hydro-
eye Ion ing
Froth
flotation
— Clean sand
Oversize Sludge Organic waste Concentrate
FIGURE 7. Schematic flow diagram case study 3.
60
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3.2.4. Case study 4.
£haracterjsa.tiori. The soil in this case study is contaminated with coal-ashes containing Polycvclic
Aromatic Hydrocarbons (PAH). There is a side-contamination of copper, lead and zinc due to traffic
emissions and other urban activities. This case study focuses on the PAH-occurrence and process
nH?n?vnn,Ce t pCf»e PA? ^"J* ^tical conBminant; In The Netherlands it is common to use a selection
ot ten types of PAH as a total PAH-content. This so called 10-PAH-conti;nt is used in this study. The PAH-
content averaged 85 ppm. «.**-«»
Figure 8 shows the distribution of the PAH over the size fractions. The size distribution of the sand is
also presented.
Concentration PAH In ppm Mass distribution in %
120 _ 60
o-a« 3«-es «»•«« as-260 aeo-5oo«oo-iooo >iooo
Particle size fraction in micron
FIGURE 8. Distribution of total-PAH over the size fractions for case study 4.
The PAH-concentration is the lowest in the main size fractions. The readsorbtion to the fines is not very
large, but still important. '
Prsssss. The coarse particles were removed by wet screening. Special attention was paid to the
hydrocycloning because of the high efficiency required. It was necessary to remove practically all the fines
The PAH-contaming low-density particles were removed in gravity separation step. Other PAH-containing
particles were removed by froth-flotation. Figure 9 shows the flow diagram of the used process The
concentration of the PAH is also given after each treatment step
Contaminated —
soil
85 ppm
Wet
screening
Over:
—
Hydro-
cycloning
21 ppm
size Sludc
res ic
—
Gravity
separation
13 ppm
je Low c
iue
—
Froth
flotation
4 ppm
iensity Com
— Clean sand
2 ppm
rentrate
FIGURE 9. Schematic flow diagram case study 4 with total-l'AH concentration.
The overall removal efficiency for PAH was 98%. The side contaminants were also removed to
satisfactory levels.
4. CONCLUSIONS
Based on a good characterization of the soil and the contaminant it is possible to design optimized
tailor-made flow diagrams. The characterization starts with a historical analysis and is completed with an
extensive chemical and physical characterization. v
For the case studies presented it was shown that differences in the physical occurrence of the soil and
the contaminants resulted into different optimized flow diagrams. The case studies presented indeed have
different flow diagrams. The difference in flow diagrams sometimes meant little adjustments in the process
in other cases it was also necessary to redesign the installation completely.
For the case studies presented removal efficiencies higher than 90% were achieved. These removal
efficiencies are typical for soil washing. In each project the sand was treated to a contaminant level that
made reuse possible.
The fundamental approach from characterization to tailor-made flow diagrams lead to optimum results
in the rea isation of soil washing projects. Using this concept of tailor-made flow diagrams, Heidemij has
successfully treated more than 200,000 tonnes of contaminated soil -B««"«a, ™iuc«uj i.-u,
61
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SOIL WASHING AND TERRAMET™ LEAD LEACHING/RECOVERY PROCESS
AT THE TWIN CITIES ARMY AMMUNITION PLANT
William E. Fristad
COGNIS, Inc., 2330 Circadian Way, Santa Rosa, CA 95407
Phone: (707) 576-6235 Fax: (707)575-7833
Craig Jones
Bescorp, Box 73520, Fairbanks, AK 99707
Phone: (907) 452-2512 Fax: (907) 452-5018
INTRODUCTION
COGNIS and Bescorp have successfully combined acid extraction (TerraMet™ metal
leaching/recovery process) with soil washing to remove eight heavy metals from contaminated soil at
Site F, an ammunition test burning area, at the Twin Cities Army Ammunition Plant (TCAAP) in New
Brighton, MN. Eight heavy metals, primarily lead and copper, were treated to the RCRA cleanup
criteria of background, in addition to live and spent ordnance removal. This represents the most
ambitious metal clean up ever undertaken. The lead contamination was a result of particulate lead,
ranging in size from 6" chunks to 400 mesh particles, as well as ionic lead adsorbed onto soil particles.
The lead concentration was lowered from an initial 3,000 - 6,000 ppm to the state cleanup criteria of <
300 ppm. AH the excavated soil fractions were treatable and returned to the site. Bescorp's soil
washing process generates three fractions: oversize, sand, and fines. The sand is density treated to
remove particulate lead and copper. The TerraMet metal extraction process then leaches and recovers
heavy metals from the sand and fines fractions with a proprietary aqueous leaching solution. Through
the combined density pretreatment and leaching process, both metallic lead fragments and dust as well
as soil bound lead salts and oxides have been treated. The lead recovered from the process is
recycled at a secondary lead smelter. The TCAAP treatability study and field-scale results will be
described.
SOIL WASHING/SOIL LEACHING PROCESS
A flow chart for the COGNIS-Bescorp remediation process is shown in Figure 1. Bescorp was
responsible for the physical separation steps, and COGNIS was responsible for the chemical leaching
and metal recovery technology. The soil is fed into the trommel where attrition breaks the soil material
down into its constituent particles of rock, gravel, sand, silt and clay. The clean oversize rock, gravel
and ordnance are rinsed and removed by a 1/4" screen. The oversize is sorted on a conveyer belt and
ordnance removed for proper disposal. The clean oversize rock and gravel exits the plant. The sand
and sill/clay fines are separated in a patented vertical separation chamber which separates the sand
from the fines by hydraulic settling forces. The metal containing fines are swept into a clarifier where
they are flocced and allowed to settie. The settled fines are pumped through a series of leaching
clarifiers. The leached fines are dewatered and neutralized before being combined with the clean
oversize and sand fractions. The sand fraction is run through a mineral jig to remove the bulk of the
metallic lead and copper particles, flecks, and dust. The partially cleaned sand fraction is then
subjected to counter-current leaching. The leached sand is dewatered and neutralized before being
combined with the fines and oversize. The metal loaded leachant is fed into the metal recovery units
where the dissolved contaminant metals are reduced out and recovered in metallic form for recycle.
The leaching-metal recovery concept is illustrated in Rgure 2. The contaminated soil fraction is
contacted with a leaching agent which dissolves a portion of the lead. The lead is removed from the
lead-rich leachant in a metal recovery stage. The lead-depleted leachant is then ready for additional
62
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contacting with new soil. The leaching process is conducted in a counter-current fashion to maximize
its efficiency. The leaching is controllable so that the lead concentration in the soil is acceptably low.
This approach completely recycles the leaching agent. Thus, the metal bearing leachant never leaves
the process, no liquid waste streams are generated, and metal recovery can be tailored to the site.
Soil Washing/Soil Leaching Process
!.:
>?:
Leach -
Ordnance.. Removal.
.Q......
Ordnance
Disposal
Recycle at
Smelter
Clean Soil
Return to Site
w*
§"
Rgure 1. COGNIS and Bescorp Field-Scale Process
63
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TerraMet® Soil Remediation Systems
Metal loaded
leachant
Recovered
Metals
regenerated
leachant
Figure 2. Lead Leaching - Recovery Concept
The preferred recovery process for lead is direct reduction of the dissolved ionic lead to lead metal.
Other metal recovery options have been tested, and the most appropriate recovery process for a
specific site depends on the leachant required and the amount and type of metals present.
RESULTS
In the treatability study, soil from the ammunition test burning area at TCAAP was studied. At
Site F both metallic lead fragments as well as ionic lead were found. Because of the high density of
lead relative to most soil constituents, the coupling of soil washing with density separation was a logical
pretreatment to leaching. Soil was first size classified to generate a sand fraction which was subjected
to density separation using standard mineral processing equipment to remove heavy lead fragments.
The results of density separation lowered the lead concentration in the sand significantly (Table 1).
Table 1.
Density Separation of Lead Particles
J&tei;.
PaitcJe Sfee^
+8
+30
+50
+100
+200
-200
,*V '
^Before ,
2050
4190
2410
4060
2900
4360
y#«JC0rJC;
'triad !
After ;
996
389
494
842
2960
2490
i Sefote^ & Affef
Removed
51
91
80
79
0
43
'Density $e
Before
NA
1436
1025
901
940
679
pwetort $
trial 2.
After \
NA
168
187
138
416'
739
Pfft) ' '' "•""
Removed
NA
88
82
85
56
0
64
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Tables 2 and 3 show the results of leaching the fines and density pretreated sand fraction. Leaching
the fines was very effective and gave residual lead concentrations of <20 ppm with leachants #2. The
results on the sand were equally satisfactory. Residual lead concentration of < 70 ppm was also
achieved with leachant #2.
Table 2.
Leaching1 of TCAAP -200 Mesh Fines
'''''• '•?
s -.^v. •. j,ff j f f
- Leaenant -
2
2
Cumulative % Pfc Leached;
teaching Cowtact #-
1 ,
59
64
,£
90
92
3
96
97
,4
97
98
$
97
98
IfiWaP "~
m -
, fo*»$ '
575
608
TFHaP
»-:
'frp»)
16
11
Table 3.
Leaching1 of TCAAP Denslty-Pretreated +200 Mesh Sand
% Pb ijeacheil
- PI
4
49
71
81
85
88
585
69
75
87
90
92
93
190
14
Data is from five consecutive contacts of soil samples with leachant
*Based upon the total Pb detected in leachant plus Pb retained in soil as
determined by nitric acid digestion.
'Based upon EPA acid digestion of treated soil.
reporting limit
After the small bench-scale experiments proved the success of the multiple leaching concept,
additional larger scale continuous leaching experiments verified the leaching results obtained earlier.
The continuous-scale apparatus more closely approximates full-scale treatment. It employs an agitated
leaching vessel from which a soil slurry is pumped into a clarifier. The clariller separates the slurry into
a clarified feed at the overflow and a thickened slurry at the underflow. The underflow is continuously
returned to the leaching vessel. The overflow is pumped into the metal recovery unit where the lead is
removed from the leachant and the lead recovered as solid lead powder. The lead-depleted leachant is
then returned to the leaching vessel for continued leaching. After leaching is complete, the soil-
leachant slurry is dewatered and neutralized. Thus, the entire leaching, clarification, and metal
recovery process operates continuously on the batch of soil in the leaching vessel. Table 4 illustrates
typical data on TCAAP soil. Routinely < 100 ppm residual lead and TCLP passage was observed. The
lead concentrations shown under the influent and effluent columns are the concentrations of lead in the
leachant entering and exiting the metal recovery unit
65
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Table 4.
CONTINUOUS-SCALE LEACHING EXPERIMENT TCAAP SOIL (DENSITY PRETREATED)
<&.s-s^/*S. *--::"--" - -"
4\,- ,!->X>^- ',, -
i^^lfetrix
"-''• f, ^5 y^w**- -.*,
Soil (Avg)
Replicate 1
Replicate 2
Replicate 3
^V -. "• s -. X: s "• •• •"•.-._. •<• ••••••••••,, "" •>
"h|;|^&'6te*» -V
Sample 1
Sample 2
Sample 3
Sample 4
Sample 5
Sample 6
Sample 7
* ,V '-Uwi-Oonceptrieeeafi (|)*g/g)
•t --^ ^ •• •"
, -ftsHjeschlrig; -
250 - 350
^yH^*it(i*gM3
15.4
10.6
4.6
2.5
1.4
0.9
0.5
- -JUeerehed
31.1
32.6
28.2
33.2
EfHueal C)*9ftni4
2.5
2.1
1.3
0.7
<0.5
<0.5
<0.5
CONCLUSIONS
The Bescorp and COGNIS soil washing/soil leaching treatment at TCAAP allows all the
excavated soil material to be treated and returned to the site. Particulate metal contaminante are
physically separated for recycle, and the ionic metal contaminants are leached and recovered for
recycle. The combined plant utilizes full recycle of all aqueous solutions and 1,600 tons of lead-
contaminated soil were processed through the full-scale system at TCAAP in mid-September through
October, 1993. The project will be completed in the Spring of 1994.
Soil washing/soil leaching has been proven at field-scale, reducing lead to < 300 ppm and
seven other heavy metals to background. However, the process is not a generic, fixed process, but
one which can be site-specifically tailored to meet the requirements of each site by utilizing the
necessary unit operations. Factors such as contaminant type and level, clean up criteria, soil
mineralogy, soil particle size distribution, and process throughput all affect processability and cost
For More Information:
Dr. William E. Fristad, .
Director, TerraMet™ Technology
COGNIS, Inc.
2330 Circadian Way
Santa Rosa, CA 95407
Phone: (707) 576-6235
Fax: (707) 575-7833
Mr. Craig Jones
Project Manager
Bescorp
Box 73520
Fairbanks, AK 99707
Phone: (907) 452-2512
Fax: (907) 452-5018
66
-------
THE B.E.S.T.® SOLVENT EXTRACTION PROCESS FOR
REMEDIATION OF PESTICIDE CONTAMINATED WASTES
Lanny D. Weimer, James Npwak & William Hems
Resources Conservation Company
3630 Cornus Lane
Ellicott City, MD 21042
INTRODUCTION
Resources Conservation Company's (RCC) patented B.E.S.T. Solvent •Fxtraction Process is
commerciany proven, cost effective treatment alternative for remediating pesticide contaminated soils
sludges and sediments. Bench scale and pilot scale treatability test data clew E eSwthl ttoB^E ST
tofSSX efff!V,ely remOVe P6StiddeS fr°m contaminate« soils (removal efficifncL >99^ £ ™
3BHC H SSLSf °PM- C°nCeHtratl0^ -(<1,PPm)' P8StiGide comP°^s removed from soils include: DDT,
PBHC (Lindane), Eldnn, Dieldrm, Aldrm, Isodrin, and Toxaphene. Process performance data are
Car°lina' ColoLdo SSornS and The
During the 1960's, the B.E.S.T. process was developed by the Boeing Company for use aboard the
to ?hUiIdin9t°nHthiS ear* Development, RCC has ad^^^S^Tbf
™ntm> ' : n° f P0mt "^ " IS a cosl effective «e*™rt alternative for pesticide
contaminated soils. Development of the B.E.S.T. process has included extensive
testin9' desisn> construction and operation of three
This paper discusses the many lessons learned as the B.E.S.T. process was develooed
s,te treatment technology for treating pesticide contaminated soils, sludges art fle^t!
research provded data on the physical and chemical properties of the B.E.S.T probe^S "solvent
2S> 7 n6- P6nCh SCa'e treatability testin9 wa= "sed to develop a testinc, protocol thai ctosely
pred,cts full scale process performance. Operation of the first two pilot scale test units provided the
necessary data for design of a continuous B.E.S.T. process configuration fo tiS^™w?w2te8
such sewage sludges and petroleum refining oily sludges. pumpabie wastes,
The full scale commercial B.E.S.T. process unit was used to treat 3,700 yd3 of PCB contaminated
ony sludges at the General Refining Superfund site located near Savannah, GA. -Tlif uS w?
sSelmrpi np^ PtT3^ S,HUd9eS- RCC leamed'tnat ^ effectively remediate hazardous waste
sites the process needs to treat both pumpable and non-pumpable wastes (soils). The third pilot scale
test unj was designed to operate in batch mode to allow the process to treat both pumpable and non
16 te? (SO'!S)- ^ Pi'0t Unit has been used at several sites to d :monstSrPerformance of
TcS^10"- LaSt year' RCC successful|y completed a Superfund Innovative TeThnofogy
(SITE) demonstration of the B.E.S.T. process with PCB contaminated sediments from the
Grand Calumet River. In early 1994, a B.E.S.T. process pilot plant conducted a series of
demonstration tests with pesticide contaminated soils at a federal facility in Colorado.
METHODOLOGY
>E
-------
The geometry of the triethylamine molecule is tetrahedral. A nitrogen atom is at the center of a three-
sided pyramid; the four points of the structure are occupied by three ethyl functional groups and one
electron cloud. This structure gives triethylamine the dual polarity which is responsible .for its unique
properties.
The property that is the key to the success of triethylamine extraction is the property of inverse
immiscibility. At temperatures below 60°F, triethylamine is miscible with water (i.e., triethylamine and
water are soluble in each other). Above this temperature, triethylamine and water are only partially
miscible. This physical property can be exploited by using cold triethylamine (below 60°F) to solvate
oil and water simultaneously.
The B.E.S.T. Process utilizes the physical property of inverse miscibility by mixing thelfeedstock
with chilled triethylamine solvent to create a single-phase extraction liquid. The liquid is a
homogeneous solution of triethylamine and the water present in the feedstock. This solution solvates
the organic contaminants (such as oils) present in the feedstock and enables the triethylamine to
achieve intimate contact with solutes at nearly ambient temperatures and pressures. This allows the
B.E.S.T. Process to maintain efficient extraction when handling feed mixtures with high water content.
Therefore, by utilizing solvent chilled below 60°F, solids can be dewatered while organic contaminants
are simultaneously extracted. Afterwards the remaining organic contaminants can be removed at
temperatures above 60°F. In addition to inverse miscibility, characteristics that enhance triethylamine's
use in a solvent extraction system include the following:
• A high vapor pressure (therefore the solvent can be recovered from the extract by way of
simple steam stripping)
• Formation of a low boiling azeotrope with water (therefore the solvent can be recovered from
the extract to very low residual levels)
• A heat of vaporization one-seventh of water (therefore, solvent can be recovered from solids by
simple heat with a low energy input)
Triethylamine is alkaline (pH=10); therefore some heavy metals can be converted to hydroxide
>H nro/-initatp and Avit thfi nrnfiess with the treated solids.
• Triethylamine is alkaline (pn=iuj; tnereiore some neavy meiaib uan
form, which precipitate and exit the process with the treated solids.
There are four basic operations involved in the B.E.S.T. process: extraction, solvent recovery and
oil polishing, solids drying, and water stripping. The extraction operation for materials having relatively
high content is additionally broken down into two types of extraction cycles. The initial primary
extraction cycles are termed "cold extractions"; secondary extractions are termed 'warm' and 'hot
extractions' depending on the temperature range at which they are conducted.
BENCH SCALE TREATABILITY TEST RESULTS
RCC has conducted several bench scale treatability tests with pesticide contaminated soils,
sludges, and sediments. The primary objective of these tests was to determine the feasibility and cost
effectiveness of the B.E.S.T. process. RCC's bench scale treatability tests are designed to provide data
that closely simulates full scale performance. The data generated by the tests allows RCC to evaluate
feasibility of the process and to estimate treatment costs.
The bench scale treatability test objectives are:
• To record observations and data to predict full-scale performance of the B.E.S.T. process
treatment train. .•....•
68
-------
• Take samples during simulation of the treatment train and conducl analysis sufficient to
determine the removal efficiency of the process for the treatment compounds of concern.
• To calculate the extraction efficiency of target compounds.
Bench-scale treatability testing of the B.E.S.T. process is conducted at RCC's Treatability Test
Laboratory located in Bellevue, Washington, USA.
c^i PU?°Se °ltheJ bench-scale treatability testing is to provide guidelines for pilot-scale and full-
scale operator* To effectively simulate the B.E.S.T. Process on a small scale, RCC utilizes laboratory
ecppment resembling pilot and full scale components. The data collected include settling data
tCh0pm|Stnnalhd1Ia;hPH data' f nd SOH a99|omeration observations. Settling data are collected to predict
the level to wh.ch the matenal would settle and the amount of time required to reach that level
SSS'tl0nhaltinHf°r^ti0n iscomPiled by the RCC laboratory to determine the amount of material to be
Smlnt * ? Obs!rvf ons such as centrifugation performance and soil agglomeration helps the
treatment system operator to recognize discrepancies from normal occurrences
Delta Engineering - The Netherlands
Bench Scale TreatabiHty Test Data
—
PESTICIDE COMPOUND
Aldrin
Dieldrin
Endrin
Endrin Ketone
Endrin Acetone
Isodrin
^===
^^~ —
FEEDSTOCK
(mg/kg)
56
150
140
280
70
340
""" — —
'-•• '-——I i —
TREATED
SOLIDS
(mg/kg)
0.1
0.3
0.02
0.5
0.1
0.28
•
==!==
REMOVAL
EFFICIENCY
(%)
>99
>99
>99.9
>99.9
>99.9
>99.9
Elf AutoChem Superfund Site - NJ
Bench Scale Treatability Test Data
PESTICIDE COMPOUND
P-BHC (Lindane)
4,4'-DDD
4,4'-DDE
4,4'-DDT
Dieldrin
=========
FEEDSTOCK
(mg/kg)
10.2
32.6
18.0
28.6
4.2
=======
TREATED
SOLIDS
(mg/kg)
0.09
0.03
0.48
0.02
0.09
—
=====
REMOVAL
EFFICIENCY
(%)
99
99.9
97
99.9
98
69
-------
FMC Superfund Site - CA
Bench Scale Treatability Test Data
PESTICIDE COMPOUND
Endosulfan
4,4'-DDT
4,4'-DDE
4,4'-DDD
Dieldrin
Endrin
FEEDSTOCK
(mg/kg)
390
500
84
190
37
140
TREATED
SOLIDS
(mg/kg)
<0.02
0.05
0.5
0.05
<0.02
0.02
REMOVAL
EFFICIENCY
(%) ,
>99.99
>99
>99
>99.9
>99.9
>99.9
Federal Facility - CO
Bench Scale Treatability Test Data
PESTICIDE COMPOUND
Aldrin
DDT
Dieldrin
Endrin
Isodrin
FEEDSTOCK
(mg/kg)
360
4.2
780
470
150
TREATED
SOLIDS
(mg/kg)
0.05
<0.01
0.039
0.04
0.28
REMOVAL
EFFICIENCY
(%)
>99.99
>99.9
>99.99
>99.99
>99.9
Plattsburgh AFB - NY
Bench Scale Treatability Test Data
PESTICIDE COMPOUND
4,4-DDT (Composite)
4,4'-DDT (Hot Spot)
FEEDSTOCK
(mg/kg)
500
3900
TREATED
SOLIDS
(mg/kg)
0.01
0.20
REMOVAL
EFFICIENCY
(%)
>99.9
>99.9
70
-------
Hercules 009 Landfill - NC
Bench Scale Treatability Test Data
PESTICIDE COMPOUND
TREATED
SOLIDS
(mg/kg)
REMOVAL
EFFICIENCY
o
CONCLUSIONS
The B.E.S.T. Solvent Extraction Process:
' Removal efficiencies for pesticide compounds is excellent, typically >99o/0,
• Residual pesticide concentrations in treated solids are very low, typically <1 .0 mg/kg,
FOR MORE INFORMATION CONTACT:
Lanny D. Weimer
Resources Conservation Company
3630 Cornus Lane
Ellicott City, MD 21042
(301)596-6066
(410)465-2887 (FAX)
71
-------
M FAMlMfi ORGANICALLY CONTAMINATED SOIL BY STEAM FXTRACT1ON
yr-SCALE EXPERIMENTS AND IMPLEMENTATION ON AN INDUSTRIAL SCALE
Hudel, K., Forge, F., Fries, A.1, Klein, M.2 , Dohmann, M.
Institut fur Siedlungswasserwirtschaft (ISA), RWTH Aachen,
Templergraben 55, 52070 Aachen, phone: 0241 /158745
1.
INTRODUCTION
The findings presented here were compiled by the institute of Aachen Technical University for Water
Management in Residential Areas (ISA) in collaboration with Bonnenberg u. Drescher Ingenieur-
gesellschaft mbH, Aldenhoven in the context of a research project sponsored by the Federal Ministry
for Research and Technology (BMFT).
Public sponsorship of the first-ever industrial-scale implementation of the process by DERA GmbH,
Aldenhoven, implemented in the form of a demonstration project, is currently being sought from the
BMFT under the auspices of the Federal Environmental Protection Agency, Berlin.
2. PROCESS PRINCIPLES
The elaborated remedial action technique can be classified as a thermpphysical process in the low-
temperature range CT = 100 to 250°C). Soil cleaning by steam is carried out by steam distillation. This
method Is the most important special application of carrier distillation. It enables high-boil.ng sub-
stances that are immiscible or difficult to mix with water to be distilled often at the relatrvely low
temperature of 100°C. From a thermodynamic viewpoint the reduction of the boiling point of not easily
volatile substances can be explained by the fact that they form a heterogeneous aceotrope in the water
mixture (1 2) When the material is subsequently heated in the mixing apparatus (steaming and jacket
heater), "microboiling" takes place inside the pores of the adsorbate. The second mechanism that is
effective is the desorption of the contamination from the solid matrix.
Steam extraction offers the following benefits:
- In contrast to processes that use hot air or inert gases, such as N2, as the heating and transport
medium the use of steam as the carrier gas reduces the boiling point of the contaminants.
- The chosen "ploughshare mixer type of reactor mechanically generates a fluidized bed, unlike
drum-type furnaces or screw conveyors. In conjunction with the disintegration of the soil agglo-
merations that form by high-speed rotating knife heads, this makes certain of a secondary stripping
effect with an optimum flow around the individual grains (Section 3 contains further details on the
- Vapour that is not entirely saturated with contaminants can easily be recycled by an injector (vapour
- Besides disintegrating soil agglomerations, the reactor used for the steam extraction process has an
additional conditioning effect: the decontaminated soil can be cooled and wetted by injecting water
before it is discharged.
No catalytic or adsorptive waste air purification is required owing to the complete condensability ot
the carrier medium. Following mechanical separation of the highly concentrated contaminant
1 DERA GmbH, Aldenhoven
2 Bonnenberg u. Drescher Ing. ges. mbH, Aldenhoven
72
-------
3.
PROCESS IMPLEMENTATION ON PILOT AND INDUSTRIAL SCALE:
comprises a cylindrical dram with axial
mixer)
operation at several such sites 6Ct'Ve author'2ati°» under mining law for
^
^^
73
-------
effluent in an oil separator (for thermal disposal or recycling as used oil). This contaminatedI aqueous
condensate can be treated by conventional industrial waste water treatment methods. Ow,ng to the
predominantly low solubility products of organically contaminated soil, adsorption P"™""^™*
favourable, especially in conjunction with relatively inexpensive lignite coke. This is illustrated by the
ZXSE^
of condensate. The theoretical water solubility of diesel fuel cdiesel/water is 20 mg/l. Therefore, 108.7
ka of the total 104 kg of contamination extracted from the soil are present as a skimmable contaminant
chase Only 03 kg are dissolved in the waste water. Two-stage coke filtration, each stage havingia
volume of Vadsorber - 5 m3, is able to adsorb 500 I contaminated oil before the material has to be
renewed (assuming a 5 % contaminant load by volume).
contamir
4j
batch
ms90-130 kg
wat«r
^— y steam
K_ generator
power
flu'u
-j> bed
mix
cttam
m=26-100ka;h
p=1-S bar
Tsio(M60'C
J
decontarr
lated soi
i
iized
er
stas
(wa
imf
I
Disp
cooling water
p=4 bar; T=1S°C
V=1 m'/h
A
- conden- ^
"^ ser
m
terand
jurities)
I 4
linated soil sew
eondensa
p=1 bar
T=20*C
\
erage
osal/Reuse
orga
(qua
pent
of in
phase se-
paration
nic phase
ntity de-
ls on grade
ipurities)
purifie
activated
corbon
filter
te watery and
non-cond.
steamphase
d water |
sewerage
txhaused act carbon
- (quantity depends on
grade of impurities)
regeneration/disposal
Figure 1: Flowchart of the pilot plant for the steam-extraction of contaminated soil
Figure 2:
Left:
Right:
Ploughshare mixer showing the mechanical fluidized bed \
Mixer with centrifuge and knife head manufactured by Lodige, Paderborn (4)
74
-------
r ' n °"t P°nf S ° a f;tSr ''fe °f 1'35° S0i' batches °r 227 irking days (two-shift operation). In order
to operate as close to the theoretical solubility limit as possible in practice, .especially close attention is
L ? i t°)COmpete Phase ^Paration in the industrial-scale configuration (utilizing coalescence
separators Mo emulsion formation was detected during the pilot-plant trials. As a consequence of the
s.mple method of grav.ty phase separation in a vessel, however, single drop* of diesel oil in the
aqueous phase increased the hydrocarbon content to 5 to 10 times the theoretical: value
In the context of the DERA project, the exhausted lignite coke will be disposed of in 'the hazardous
waste incinerator operated by the same company on the same site.
Besides designing effluent treatment provisions with the objective of feeding the cleaned condensate
mto the municipal sewer system, the technical and economic feasibility of further treating the process
water for reuse ,n steam generation is to be investigated. Owing to the stringent requirements as
regards the purity of the boiler feed water, membrane processes may have to be employed iHerT
4. DECONTAMINATION RESULTS , ,
Table 1 lists the experimental parameters and decontamination results of a number of trials. Note the
relatively low process temperatures at which a favourable decontamination .efficiency can be achieved
«- "—the Lence of
n h,nHH thUS far demonstrate that soil P°lluted ^h BTX/CHC (chlorinated hydrocarbons)
can be thoroughly decontaminated by steam treatment lasting from only 15 minutes to one hour. A
higher specific steam consumption is required with highly adsorbent matrices. The influence of adsorp-
f ? f m°re SiQnifiCant With mineral ol- hydrocarbon, whose COC values aTe
those of volatile substances by several powers of ten, This is illustrated by the reduced
° mSnt ^^ a l° SOH °0ntaining Clay and siit that '* artificially contam"
n nCy 96%' °f- T3ble 1) C°mpared With that <*«"* whe"
predommanty sandy soil by steam extraction (decontamination efficiency > 99%). Both this
1 wh h *? ? ?We 1 With hybHd contamination "«* taken from a thoroughly contaminated
dur^n frtS V ,P°"UtantS °V6r 3 Peri°d °f ma"y years" A 'eduction in the necessary
duraton of treatment can be anticipated with fine-grained soil owing to the shift in the
temperatures in conjunction
reSU'tS obtained with the three PCB-contaminated samples
h thS Iab°rat0ry Scale3 verifV the influenc« of stripping effects
h H T reS'd"Vreated in a distillation "ask with an inserted giass tube acting as a steam
had an oily or sludgy consistency. It was therefore "boiled" during the steam treatement at
temperatures between 100 and. 140°C, but drying and swiriing were omitted The PCB
mtrin th , f Um'Ce" 3nd "Si'ica Sand" batches' which occurred ^ a loose heap of
material in the still and was therefore more effectively enveloped by the injected steam. '
3 For safety reasons; results of pilot-plant trials available at the end of '93
75'
-------
-4
0\
Soil/residue
Fine sand 0 - 2 mm
Soil with 8 % clay
and 22 % silt
Alumina (exhausted
adsorbent, AlpO^)
Sandy soil with silty
secondary components
Soil with 8 % clay
and 22 % silt
Sandy soil with
silty secondary
components
Loess soil
(> 80 % clay/silt)
Grit chamber residue
Pumice *)
Silica sand *
Contamination
Volatile substances
Mineral oil
Hybrid contamination
(chlorophenols, HCB,
HC)
PAH
PCB**)
BTX/CHC cocktail*)
1 % by weight
BTX/CHC cocktail *)
1 % by weight
CHC, 4.1% by weight
as BOX
Diesel oil contamination
HC = 0.16 %
Diesel oil contamination
*)
HC - 1 %
HC = 0.85 %, HCB = 320
g/kg as EOX, chloro-
phenols*) = 400 g/kg
(Dimethyl-) Naphalene,
Fluorene, Phenanthrene,
Acenaphtene, 740 mg/kg
I4.7mg/kg
198.8 mg/kg
60 mg/kg
Experimental parameters
Mixer
[°C]
104
100-130
103
103
130
104
120
100-140
100-140
100-140
Batch
[kg]
110
110
100
90
130
89
100 g
25 g
100 g
Duration of
treatment
[min]
15
60
60
120
150
120
150
180
180
180
Spec, steam
consumption
mp/mB [-]
0.14
0.66
1
0.53
1.78
0.98
1-7
6-7
30-40
0.8-2
Decontamination
efficiency
[%]
99.95
99.975
99.8
>99
96
99.9
99
92
>99.9
97-98
Table 1: Decontamination results of steam extraction
*) Contaminated artificially **) Laboratory scale
from soil and residues (excerpt)
-------
5.
PROCESS APPLICATION AREA
In principle, the process can be used with volatile contaminants (chlorinated hydrocarbons, BTX), but
especially with contaminants with a higher boiling range that are volatile in stearn. The following sub-
stance classes of contaminations are considered volatile in steam (1, 5, 6, 7):
Hydrocarbons and mineral oils
(boiling range
TB = 200 to 3550 °C)
(TB = 180 to 350 °C)
(TB = 270 to 400 °cj
(TB =300 to 410 °C)
Chlorinated aromatic compounds and phenols
Polycyclic aromatic hydrocarbons
Polychlorinated biphenyls
Polychlorinated dibenzodioxins.
Steam extraction reaches its application limits in the presence of extremely high boiling PAHs, such as
occur in the form of the tar pitch residue from coal tar processing. While production residues with an
volatile contamination spectrum can be advantageously treated, contaminated sites with exclusively
volatile contaminations can probably be cleaned less expensively by the in-situ method of soil air
extraction.
COSTS
Table 2 contains an investment and operating cost estimate for the demonstration plant described in
Section 3. The calculation is based on two-shift operation and an assumed relatively small number of
operating days, namely 200 a year. This value takes account of down-times that may be necessary
owing to technical modification and optimization measures. The investment costs of the machines and
equipment are depreciated over three years (usual period for a publicly sponsored R&D project).
Besides the principal assemblies, that is the steam generator, ploughshare mixer and condenser, the
investment cost of the plant components in the amount of DM 57.2 million (line B.1) also covers the soil
pretreatment and steam extraction unit loading equipment, and the treatment facility for the
contaminated condensate. The personnel expenses for 3 plant operators per shift, contained under
general costs (line C.1), make up some 20 % of the overall capital requirement.
The cost of supplies (line C.2) primarily contain energy costs for steam generation and the procure-
ment of electricity to drive the mechanical fluidized bed reactor; it also contains the cost of industrial
water. The cost of residual material disposal embraces the disposal or reprocessing of the oil-con-
taminated condensate and the regeneration or disposal of the exhausted active coke from the effluent
treatment stage.
The most significant cost factor of the new steam extraction process is the general costs (personnel,
insurance, maintenance). The investment requirement makes up about one-third of the total budget,'
while the cost of supplies and residual material disposal accounts for less than 1 o %.
77
-------
A
A.1
A.2
A.3
B
R1
B.2
B.3
R,4
0
C.1
0?
C.3
D
Estimates for financing and engineering
Depreciation period
Machines and equipment
Construction engineering
Investment costs
Plant components
Planing, authorization
Miscellaneous
2 Investment costs
3.0 a
3.0 a
DM '000
5,720
320
262
6,302
Operating costs
General costs
(personnel, maintenance etc.)
Cost of supplies, residual material disposal
S Operating costs
Total cost of demonstration plant
Capacity
Capacity/h
Oper. hours/d
Capacity/d
Oper. days/a
Oper. hours/a
Annual cap.
DM '000/a
2,091 .00
88.47
105.42
2,284.89
DM '000/a
3,405.76
604.80
4,010.56
6,295.45
5.20 t/h
16.00 h/d
62.40 t/d
200.00 d/a
3,200.00 h/a
1 2,480.00 t/a
•-•. DM/t :
125.66
5.32
6.34
137.31
DM/t
204.67
36.35
241.02
378.34
% •
33.21
1.41
1.68
36.29
%
54.10
9.63
63.71
100
Table 2: Cost estimate for the construction and operation of an industrial-scale plant for cleaning
organically contaminated soil by steam extraction
7.
BIBLIOGRAPHY
1. Sattler, K. Thermische Trennverfahren, VCH Verlagsgesellschaft mbH, Weinheim, 1988
2. Grassmann, P. Physikalische Grundlageri der Verfahrenstechnik; Salle+Saueriander, Frankfurt,
1983
3. Figuera, Maria E. Ober die Wasserdampfregeneration von Aktivkohle - Beitrag zum Entfernen von
Schadstoffen bis in den umweltreievanten Konzentrationsbereich, Dissertation Universitat Kaisers-
lautern, 1987
4. N.N. Herstellungsprogramm Pflugscharmischer, Firmenprospekt Fa. Lodige, Paderborn, 1990
5. N.N. Kraftstoff - die treibende Kraft, Firmenbroschure der BP Tankstellen GmbH; Hamburg,
2.Auflage 1990 .
6. Victorelli, J.C., de Andrade, P.S., Elkaim, J.-C; Chlorinated Hydrocarbons Liquid Wastes: Steam
Extraction In Place Of lncineration;Water Science and Technology; Volume 24; Nr.12; 1991
7. Veith, G.D., Kivus, L.M.; An Exhaustive SteanvDestillation and Solvent Extraction Unit for Pestici-
des and Industrial Chemicals; Bulletin of Environmental Contamination and Toxicology; Bd. 17;
1977;
78
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HYDRAULIC FRACTURING TO IMPROVE REMEDIATION OF CONTAMINATED SOIL
William W. Slack
MarkKemper
Lawrence C. Murdoch
Center for GeoEnvironmental Science and Technology
University of Cincinnati
1275 Section Road
Cincinnati, Ohio, 45237-2615
INTRODUCTION
In situ methods of removing contaminants from soil offer cost effectiveness and limit additional
exposure to the contaminants. However, those techniques that depend on movement of water or air
through the soil are hampered by low permeability at many sites. -
Hydraulic fracturing provides the potential of dramatically improving the effectiveness of most
remedial technologies that require fluid flow in the subsurface; these include soil vapor extraction (SVE
or vapex), bioremediation, soil flushing, and pump and treat. Hydraulic fractures can also be used as in
situ reservoirs of materials, such as compounds that release oxygen and nutrients, to enhance
bioremediation.(1) Fractures can be filled with electrically conductive materials to induce contaminant
migration by electroosmosis or electrophoresis or to improve Joule heating, which may increase
microorganism populations and metabolic activity, volatilize contaminants, .or cause vitrification.
Long recognized as a method of increasing the yields of oil wells, hydraulic fracturing has been
adapted for use in the subsurface as a method to enhance environmental remediation. The technology
is particularly suited to sites underlain by soils where the lateral component of stress exceeds the vertical
stress applied by the weight of the overburden (these soils are termed overconsolidated.) Fractures
created in overconsolidated soils tend to propagate in a horizontal to sub horizontal plane, allowing the
fractures to reach maximum dimension without intersecting the ground surface. In general, they are 1 to
3 centimeters thick, slightly elongate in plan, asymmetric with respect to their parent borehole, and as
much as 14 meters (m) in diameter. This geometry, in most cases, will be the most favorable for in situ
technologies that utilize vertical wells. Glacial drift of the Midwest and Northeast, swelling clays of the
Gulf coast, and similar soils are frequently overconsolidated and suitable for hydraulic fracturing.
Depositional stratigraphy may also influence the geometry of fractures, so normally consolidated soils
that are strongly bedded may also be amenable to hydraulic fracturing.
The technology is most effectively applied to low permeability (less than 10'5 centimeter per
second [cm/s]) silts, clays, or rock. By causing a substantial increase in effective permeability, hydraulic
fracturing can improve the extent of influence of wells and spatial distribution) of in situ remediation
processes, decrease remediation time, and minimize the number of wells needed for remediation.
Indeed, without fractures many sites could not be considered candidates for in situ remediation.
Under the auspices of the SITE program, hydraulic fracturing has been demonstrated at three
sites.(2) Field studies at the US EPA Center Hill Solid and Hazardous Waste Research facility were
conducted to determine the performance of hydraulic fracturing in silty clays. Sand filled hydraulic
fractures were also created at a contaminated site in Oak Brook, Illinois (the Oak Brook Site) where SVE
is being tested for removal of chlorinated solvents from soil. Another contaminated site in Dayton, Ohio
(the Dayton site) was studied to determine the effectiveness of this technology in enhancing
bioremediation of petroleum fuels. The demonstrations showed that flow rates through wells completed
with hydraulic fractures were 15 to 40 times greater than unfractured wells. Hydraulic fractures extended
the zone of influence around wells by a factor of 10 or more. At the Oak Brook site, an order of
magnitude increase in contaminant yield was observed.
79
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METHODOLOGY
A hydraulic fracture is created when fluid is pumped into a borehole until a critical pressure is
reached and the enveloping soil fractures. Sand-laden slurry is pumped at rates between 60 to 100 liters
per minute into the fracture as it propagates away from the borehole. The base fluid in the slurry is a
viscous aqueous solution of cross linked guar gum that can easily entrain and transport sand grains. The
slurry system also contains enzymes that degrade the guar gum polymer several hours after pumping is
completed. The aqueous solution loses viscosity as the gel degrades, drains away, and leaves behind a
highly permeable pathway for delivery or recovery of fluids in the subsurface.
Initiation of a horizontal fracture is facilitated by creating fracture nucleation sites, usually at the
perimeter of a horizontal disk-shaped void within the soil. The void can be created by rotating a
horizontal high pressure jet around the side of a borehole and thereby eroding a notch extending 10 to 15
cm into the wall of the borehole. These operations are commonly executed in an open hole section
below casing that has been driven into soil: The lateral pressure of the soil oh the outer wall of the
casing effectively seals the casing and prevents leakage.
Location and growth of fractures can be monitored during installation by observing the upward
displacement of the ground surface with a leveling telescope. The uplift pattern typically appears as a
broad, shallow dome several meters in diameter and 1 to 2 cm in altitude. Based on our results, uplift
appears to equal the thickness of the shallow, gently dipping fracture.
The equipment necessary for hydraulic fracturing include a mixer for preparing a slurry of
several hundred liters of gel and hundreds of kilograms of sand within a few dozen minutes, a pump to
inject slurry, and supporting equipment. The equipment used for SITE program demonstrations cost
approximately $93,000. This equipment allowed installation of as many as six fractures in a day. Cost
of material used in a single fracture varies but typically ranges from $150 to $300.
RESULTS
Demonstrations at three sites have documented the improvement in rates of fluid movement into
or out of wells and the expansion of influence of wells that can be accomplished by using hydraulic
fractures. These three sites, all underlain by the glacial till that occurs in much of the Midwest, are in
Cincinnati and Dayton, Ohio, and Oak Brook, Illinois.
Center Hill Site
This site, an uncontaminated US EPA testing facility in Cincinnati, is underlain by a silty clay with
lesser amounts of sand and gravel, the characteristics of soil amenable to hydraulic fracturing. Five
wells were installed to compare the differences of fractured and unfractured wells, to determine the effect
on performance from venting of the fracture to the surface, and to assess the performance of wells with
multiple fractures. Three wells with hydraulic fractures were installed. One well had hydraulic fractures
at 1.5 and 3 m below ground surface (bgs). A second well had a single fracture at a depth of 1.5 m that
vented to the surface 7 meters (m) from the well. The third well had a single fracture at 1.5 m that
remained below the surface. Two conventional wells were screened in unfractured ground. The wells
were connected to a vacuum blower that was capable of 300 cm of water of suction. Pneumatic
piezometers were installed around the wells to measure suction head in the soil.
Well discharge, as both vapor and liquid flow rate, was an order of magnitude greater for the
fractured wells than the unfractured wells.(2) For the fractured wells, rate correlated strongly with
precipitation; after heavy rainstorms yields of vapor would decrease, substantial water would be
produced over the next few days, and the system would gradually recover. The vented fracture was
more responsive to rainfall than the unvented fractures. The conventional wells were unaffected by rain.
80
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Suction head was detectable at greater distance from the wells with fractures than from the wells
without. Around the conventional wells, suction was about 3 cm of water at a distance of 1 m. In
contrast, the same suction head could be observed 8 m from the fractured wells. Also, suction around
the fractured wells was influenced by rainfall events. Suction head would decrease gradually during
drying of the soil and increase significantly after heavy precipitation.
Oak Brook Site
Contaminants consisting of trichloroethene (TCE), 1,1,1-trichloroethane (TCA), 1,1-
dichloroethane (DCA), tetrachloroethene (PCE), and other solvents are present in silty clay till to depths
of 6 m bgs. Hydraulic conductivity varies from 10'7 to 1Q-8 cm/s. The low conductivity hinders vapor
extraction. In order to improve extraction rates, hydraulic fractures were created at depths of 1.8, 3, and
4.6 m bgs at two locations. Ground surface uplift measurements showed a maximum thickness of 2.5
cm and indicated a lateral extent of about 6 m. Multi-level recovery wells, Wells No. RW3 and RW4,
were installed to connect each fracture individually to a two-phase vapor extraction system. The vapor
recovery rates from these two wells were compared to rates from similarly screened zones in unfractured
Well No. RW2. A multi-level monitoring system consisting of as many as six pneumatic piezometers per
borehole was installed at radial distances of 1.5, 3, 4.6, and 7.6 m from each recovery well.
The vapor flow rates and contaminant concentration were measured using variable area flow
meters and gas chromatography. Other parameters of interest included water discharge from the vapor
extraction system, soil moisture content, and soil vacuum at the recovery wells and the monitoring holes.
Vapor discharge rates from Wells Nos. RW2, RW3, and RW4 are presented in Table 1. The
average discharge rates from the fractured wells, RW3 and RW4, were 15 to 20 times greater than
unfractured Well No. RW2. Discharge from fractured wells tended to fluctuate, while that for Well No.
RW2 was more consistent. The fluctuation may have been due to Changes in subsurface caused by
precipitation events.
TABLE 1 - VAPOR DISCHARGE RATES AT THE OAK BROOK SITE
Well
No.
RW2
RW3
RW4*
RW4**
Range of
Rates
liter / sec
0.047 - 2.2
1.0-10.4
13.2-20.1
8.1 - 14.0
Average Rate
liter / sec
0.52
6.7
16.1
10.7
Fraction
discharged from
1 .68 to 1 .98 m bgs
0.47
0.61
0.34
Not Applicable
Fraction
discharged from
2.90 to 3.20 m bgs
0.27
0.09
0.36
Not Available
Fraction
discharged from
4.42 to 4.72m bgs
0.24
0.30
0.23
Not Available
' The 1.8m fracture at Well No. RW4 vented to the surface. Data for this line include discharge when
suction was applied simultaneously to all three fractures.
** This line shows data from when suction was applied to the 3 m and 4.6 m fracture only; hence, well
discharge was less than when suction was applied to all three fractures.
Mass recoveries for ten targeted compounds were computed for each well from concentration
and discharge measurements (Table 2). Mass recoveries from hydraulically fractured wells were
approximately one order of magnitude greater than that from the unfractured well. Mass recovery rate
from all wells decreased through time.
81
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TABLE 2 - RECOVERY OF CONTAMINANTS FROM OAK BROOK SITE
Well"
No.
RW2
RW3
RW4
Time
(days)
60
60
' 60
Mass of
VOCs
Recovered
(kilograms)
2.3
10.4
3.6
Time
(days)
110
110
110
Mass of
VOCs
Recovered
(kilograms)
2.7
16
7.3
Time
(days)
160
160
160
Mass of
VOCs
Recovered
(kilograms)
2 7
19
8.6
S ? i « measurements provide insight into the extent of influence of a well. Suction head
abruR X Wlth dlstance from the unfractured well.from 670 cm of water suction in Well No
c*!? '"l"161^ jmm) of water at * Piezometer 1.5 m away. On the other hand, suction head
decreased gradually with d.stance from the fractured wells, ranging through pressures of 40, 33, 1 and
0.5 cm of water at distances of 1 .5, 3, 4.6, and 7.6 m from the well, respectively.
Dayton Site
D*0n, % H* ""d6^01"1* ^^^ tanks (USPs) were removed prior .to fracturing work
™ ™ In° * b!nZ6ne' t0'Uene' ethy|benzene- *V'ene (BETX), and other petroleum
hydrocarbons. The site is underlain by stiff sandy to silty clay with traces of gravel Hydraulic fractures
were p ace at depths of 2.1, 2.4, 3, and 3.7 m bgs. Water containing hydrogen peraddeS bSSST
nutrients was introduced into a fractured well and an unfractured well. .uiuiugicai
samp'e!,wf re collected at distances of 1 .5, 3, and 4.6 m from the wells using a split spoon
f 1 , T9, remldiation- The samP|e from each spoon was analyzed for moisture
?lf!l(Sred We" were 25 to 4° times 9reater than into tne unfractured well, and
a,fff?e,d?e m°IStUre in the soiL After 1 month- soil moist"^ content 1.5 m from
nrr n th "? 1 >4 '*?«? ^m?S 9feater tha" tfl6 unfract"--ed well. Moisture content generally were
greater near he fracture with the largest increase near the uppermost fracture. The same trends in
moisture content were also observed 3 and 4.6 m from the wells
TABLE 3 - CONTAMINANT DEGRADATION AT THE DAYTON SITE
At 5 feet from
Fractured Well
Unfractured Well
At 10 feet from
Fractured Well
Unfractured Well
At 15 feet from
Fractured Well
Unfractured Well
Percent Degradation After 1 month
Benzene
Nl*
Nl
47
Nl
Ethyl
benzene
Toluene
TPH
97
8
Nl .
Nl
77
0
79
72
Nl
Nl
58
27
64
Nl
73
Nl
Nl
Nl
51
Nl
Percent Dearadation After 6 months
Benzene
80
Nl
12
Nl
38
Nl
Ethyl
60
37
Nl
90
56
Nl
No Impact
Toluene
Nl
Nf
Nl
Nl
Nl
Nl
TPH
71
55
54
67
68
82
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Effectiveness of bioremediation was gauged by reduction in BETX and TPH concentrations in
soil samples. Percentages of contaminant degradation, compared to baseline measurements, are
reported in Table 3. Generally, reduction was greater around the fractured well than the conventional
well. Considerable variation among the degradation data is evident and may be due to local variations in
contaminant concentration that was unresolved by sampling, or other factors.
CONCLUSIONS
Hydraulic fractures can substantially improve performance of in situ remediation projects such as
vapor extraction, bioremediation, and free product recovery. Using a well intersecting a hydraulic
fracture, these improvements are realized as increased rate of removal or addition of fluids through the
well and more wide-spread influence of the well. The rate of discharge or injection appears to be more
than 10 times greater than for a conventional well. Wells intersecting hydraulic fractures appear to affect
the pressure distribution 10 times further distant (and 100 times the area) than their conventional
counterparts. These improvements in physical performance are matched by similar improvements in
remediation, according to available data.
REFERENCES
1 Vesper, Murdoch, Hayes, and Hoover. Solid Oxygen Sources for
Bioremediation in Subsurface Soils. J. Hazardous Materials. Accepted
2 Hydraulic Fracturing Technology. EPA/540/R-93/505, U.S. Environmental
Protection Agency, Cincinnati, Ohio, 1993.
3 Wolf, A. and Murdoch, L.C. The Effect of Sand Filled Hydraulic Fractures on
Subsurface Air Flow. Outdoor Action Conference. 1993.
FOR MORE INFORMATION
Contact: Dr. William W. Slack
(513) 556-2526
Fax (513) 556-2522
83
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X-RAY TREATMENT OF ORGANICALLY CQNTAMINATt=n AQUEOU
Vernon L. Bailey, Jr. and Heinz Lackner
Titan/Pulse Sciences, Inc.
600 McCormick Street
San Leandro, CA, USA 94577
(510)632-5100
Esparanza P. Renard
U.S. EPA, RREL
2890 Woodbridge Avenue
Edison, NJ, USA 08902
(908) 321-4355
Randy Curry
Tetra Corporation
3701 Hawkins Street
Albuquerque, NM, USA 87109
(505)345-8623
Norma Lewis
U.S. EPA, RREL
26 W. Martin Luther King Drive
Cincinnati, OH, USA 45268
(513)569-7665
UTI
INTRODUCTION
Hie* rac"ation !s hj9h|y effective in decomposing or modifying organic compounds This paper
discusses the use of lomzmg radiation, namely x-rays, to decompose toxic organic substances X-ray
matment of organically contaminated aqueous solutions is based on the in-depth deposition of ionizlnq
s±Xn> ? f nS Of,ehne^etic Photons (™^ wi'h Batter generate a shower of towe energy
%£?£?« IT Thm f contaminated waste material. The secondary electrons cause onization
and excitation of the atom.c electrons, break up the complex molecules of the contaminants, aSm the
ox.diz.ng hydroxyl ! radical (OH-) and the reducing aqueous electron (eaq) and hydrogen radical (H-) that
react with ithe contaminant materials to form nontoxic by-products suchaa water, carbon dSe and
oxygen S.nce h.gh energy x-rays and electrons transfer their energy to the background med a b'v similar
interactions, x-ray processing should be similar to direct electron beam processing wXas also
shown to be a highly effective means of destroying organic contaminants in
th» cam effeCtce penetra|ion dfPth °f an x-ray in a material is much larger than that of a electron of
the same energy For example, a 1 MeV x-ray has an effective penetration depth of 27 cm in wateTwh e
^ USl? f r0" hdep°Slts lts energ/ within 4 mm- At 1° MeV the effective range of an x-ray in watens 66
cm while that of the same energy electron is 5 cm. While x-rays have a larger effective penetration
than electrons, the efficiency of producing x-rays is much less than that ftj • etectrons X?ays fo ?ad
p ocessmg are obtained by first producing a high energy electron beam which is directedfnto a h gh
atomic number material (called a converter) thereby producing bremsstrahlung radiation as thl electrons
slow down The conversion efficiency from energy of the incident ^titromto^^^^S^
?nHS n M v?n? frCt'0n °f hS 6nergy °f the incident electrons' ™e usef"' conversbn efficlncy oM 5
and 10 MeV electrons in a tantalum converter are 1.6%, 8.4%, and 16 6% resDectivelv Thl
energy of eitherx-rays or electrons used in radiation processing ^i, generalj "SSSto'; 10
nuclear activation (photo-disintegration reaction) of the working media.
84
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Even though x-ray treatment is inherently less efficient than direct electron beam treatment, x-ray
treatment is either the preferred method or the only option available when the depth of penetration is
important such as treatment of thick waste streams (> 2 inches), soils, and solids. Since electrons do not
penetrate deeply, contaminated material must be presented to the beam in thin sections and handling can
be a problem especially if the contaminated liquid is stored in a barrel or tank. The deeper penetration of
similar energy x-rays offers the potential for in-situ treatment of contaminants in a barrel or a tank.
Because of the much larger efficiency, direct electron beam treatment is preferred when the depth of
penetration of the electrons is not a problem such as treatment of thin streams of liquids.
A high power, high energy electron accelerator plus x-ray converter generate the x-rays used in
the treatment process. The accelerator energy which must be small enough to avoid activation and as
large as possible in order to improve the bremsstrahlung conversion efficiency will most likely be « 8-10
MeV. A pulse of electrons 50 to 100 nanoseconds long is directed onto a cooled high atomic number
converter to efficiently generate x-rays.
The viability of x-ray treatment of organic wastes depends on the existence or development of an
efficient high power, high energy electron accelerator. RF linacs can easily obtain the energies of interest
but are limited to power levels of approximately 50 kW and electrical conversion efficiencies of less than
20%. New developments in RF sources will most likely increase the power levels to » 100 kW but the
efficiency is expected to remain low. Electron accelerators such as the insulated core transformer or
Cockcroft-Walton (Dynamitron) are very large accelerators and are limited to energies < 5 MeV. The
linear induction accelerator (LIA) in which the beam passes through a large number of acceleration gaps
thereby summing the energy of the gaps, can be efficient electrically (« 50%), easily produce the energies
of interest (50 MeV ATA accelerator) and high power (> 175 kW based on existing sources). A compact,
transportable induction accelerator called the Spiral Line Induction Accelerator (SLIA) is being developed
by Titan/Pulse Sciences, Inc. (PSI). The estimated size, weight, and cost of a transportable 400 kW (8
MeV, 1.8 kA, 25 nsec, 1.1 kHz) SLIA are 12 m3 for the size, 4.5 tons for the weight, and $3 M for the cost
of the accelerator.
METHODOLOGY
The U.S. Environmental Protection Agency (EPA) and the Department of Energy (DOE) under the
SITE Emerging Technology Program have entered into a cooperative agreement with Titan/PSI to eval-
uate the x-ray treatment process for the remediation of liquid wastes contaminated with volatile (VOCs)
and semi-volatile (SVOCs) organic compounds. The objective of the program was to demonstrate in small
scale experiments the efficacy of x-ray treatment for liquid wastes contaminated with VOCs and SVOCs,
and to determine the x-ray doses required to reduce the organic contamination to acceptable levels.
A linear induction accelerator at PS! was used to generate a 1.2-1.4 MeV, 800-1000 A, 55 nsec
electron beam at the rate of 1-2 pulses per second. The energy of the electron beam was converted to x-
rays in a high atomic number bremsstrahlung converter. The converter consisted of an electron beam
vacuum window (2 mil titanium foil), a high "Z" material (5 mil tantalum foil) and a beam stop (0.2 inch
graphite). The converter was water cooled to allow continuous operation. At a 10 cm distance from the
converter an x-ray dose of 5-8 rads per pulse was applied to the samples uncier test. To accumulate a
large x-ray dose in the sample, multiple radiation pulses were applied to the sample at the repetition rate
of one pulse per second. The samples were continuously rotated during irradiation thereby allowing a
more uniform dose of x-rays to be applied to the samples. A closed irradiation chamber allowed the
samples to be irradiated in a nitrogen atmosphere to prevent ozone formation.
Radiation dosimeters were placed directly on each of the samples being irradiated. Below 20
krads lithium fluoride TLDs (thermoluminescence detectors) were used to measure the dose and above 20
85
-------
krads the x-ray dose was measured with radiochromic film. Both dosimetry techniques have been
calibrated against NISTstandards. .,,,,.-
The samples which were irradiated were either prepared by certified laboratories from neat (no
solvents) solutions of VOCs or SVOCs in reagentgrade water or were from contaminated wells There
were two sources of contaminated well water. Florida International University (FIU) provided well water
primarily contaminated with carbon tetrachloride. A certified laboratory then added a known amount of
additional contaminant to these samples before they were irradiated. Contaminated well water samples
from a Superfund site (Lawrence Livermore National Laboratory, LLNL) were also included in the
investigation. The samples were generally prepared in 40 mi VOA vials.
Samples with the identical contaminant concentration levels were irradiated at increasing dose
levels to determine the rate (concentration versus dose) at which the contaminants were being destroyed
and the x-ray dose required to reduce the organic contamination to acceptable levels. After irradiation the
samples were analyzed by a certified analytical laboratory.
RESULTS
The results of the x-ray irradiation of the samples prepared with a neat solution of the contaminant
in reagent grade water are shown in Table 1. Twelve different contaminants in 15 aqueous matrices were
investigated. The compounds such as chloroform, methylene chloride, 1,1,1 trichloroethane and carbon
tetrachloride which do not contain a double bond and do not react as strongly with the hydroxyl radical
required a much large dose to destroy than the VOCs which do react with the hydroxyl radical.
TABLE 1. SUMMARY OF X-RAY RADIOLYSIS EXPERIMENTS ON NEAT SOLUTIONS OF
CONTAMINANTS IN REAGENTGRADE WATER.
Compound
TCE ;
TCE
fVmf^pm
TCE
••pyM^fV
TCE
*-ff-^f—
PCE
Chloroform
Methylene Chloride
Trans 1,2 Dichloroethene
Cis1,2Dichloroethene :
1,1,1 Trichloroethane
Carbon Tetrachloride
Benzene
Toluene
Ethylbenzene
Xylene
Matrix
Deionized
Water
*
Initial
Concentration
(ppb)
64,000
2100
1000
490
230
2000
270
260
13
' 590
180
240
150
890
240
Final
Concentration
(ppb)
< .5
< .5
<,.5 .
< .5
3.6
4.4
3.1
.78
54
14
< 5
3.6
1.2
X-ray
Dose
(kR)
180
20
10
10
4.2
178
145.9
10.6
10.6
207.1
224
88
w. w
4.83
20.4
5.6
Test
Method
8010
8010
8010
8010
8010
8010
8010
8010
801 n
Uw I w
8010
8010
anon
otj4£u
8090
UwJ^W
8020
8020
Table 2 summarizes the results for the well water samples from FIU and the Superfund site at
LLNL. The doses required to destroy the VOCs which react strongly with the OH- radical increased for
the well water sample. For example, benzene concentrations of 240 ppb and 262 ppb were irradiated in
deionized water and well water. In deionized water, 8.8 krads mineralized the benzene while 30 9 krads
were required for the mineralization of a similar initial concentration of benzene in well water Both the
spiked FIU well water samples and the two sets of samples from the Superfund site had high concen-
86
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trations of carbonate and bicarbonate ions.which have large reaction rates with the OH- radical. The
carbonate and bicarbonate ions appear to act as OH- scavengers thus impeding the destruction of the
VOCs which react strongly with the OH- radicals.
TABLE 2. SUMMARY OF X-RAY RADIOLYSIS EXPERIMENTS ON CONTAMINATED WELL WATER.
Compound
Benzene/carbon tetrachloride
Ethylbenzene/carbon
tetrachloride
D-xylene/carbon tetrachloride
Matrix
FIU Well
Water
FIU Well
Water
FIU Well
Water
Initial
Concentration
(ppb)
262/400
1000/430
221/430
Final
Concentration
(ppb)
< .5/196
,
<. 5/70.9
< ,5/85
X-ray
Dose
(kR)
39.9/93.8
33.2/185
20.5/171
Test
Method
FIU
FIU
FIU
Superfund Well Water Sample #1 :
TCE
PCE
1,1 Dichloroethane
1,1 Dichloroethene
1,1,1 Trichloroethane
Cis 1 ,2 Dichloroethene
SFWW1
SFWW1
SFWW1
SFWW1
SFWW1
SFWW1
3400
500
<10
25
13
44
<.5
< .5
1
<1
2.0
<.5
99.Q
99.0
145.4
49.9
145.4
49.9
8240
8240
8240
8240
8240
8240
Superfund Well Water Sample #2:
TCE
PCE
Chloroform
Carbon tetrachloride
1 ,2 Dichloroethane
1,1 Dichloroethane
Freon
SFWW2
SFWW2
SFWW2
SFWW2
SFWW2
SFWW2
SFWW2
5000
490
250
14
38
11
71 ;
<1.0
1.6
81 .
4
17
6.8
32
291
291
291
291
291
291
291
8240
8240
8240
8240
8240
8240
8240
An x-ray dose of 150 krads was sufficient to reduce ail the contaminants in the first (sample,*!)
Superfund water samples to values which were below those established by the California Primary Drinking
Water Standards. For the second more highly contaminated sample #2, a maximum dose of 291 krads
was applied to the sample. This dose reduced three out of the seven contaminants to below the drinking
water standards. It is estimated that a maximum dose of 500 krads would be required to reduce all of the
contaminants to concentrations below the drinking water standards. , :
High contaminant levels of TCE and PCE in aqueous solutions were treated with x-rays to
investigate the potential for hazardous by-product formation. Preliminary analysis of five out of six sets of
experimental samples showed concentrations of chlorinated hydrocarbons which were below the detection
limit (< .5 ppb). In one set of experiments in which chlorinated hydrocarbons were found a problem with
the analytical analysis is suspected. Analysis of the final set of samples for evidence of the aldehydes or
organic acids is in progress.
CONCLUSION i
A large number of VOC and SVOC contaminants found in Superfund sites were successfully
decomposed (destroyed) by x-ray treatment (radiolysis) of the contaminated aqueous solutions. The ,
87
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concentrations of all of the VOC and SVOC contaminants which were investigated were significantly
reduced during x-ray irradiation. When no OH- scavengers were present, contamination levels of a few
?^ PPb were destroyed by doses of a few 10's of kilorads for the contaminants which react strongly
with the hydroxyl radical. Much larger doses were required to remediate the contaminants which
ofonn. w Str°ngly With the hydroxvl radical- For these contaminants
a few 100 s of kilorads were required to destroy initial concentrations of a few 100's ppb.
The five sets of experiments carried out with contaminated well water demonstrated the effects of
having OH- scavengers present in solutions with an OH- active contaminant. Approximately a factor of
five higher x-ray doses were required for the OH- active contaminants when the OH- scavenger carbonate
and bicarbonate ions were present. As would be expected the rate of remediation for carbon
tetrachloride, which is not OH- active, was not effected by the carbonate and bicarbonate ion in the
contaminated FIU well water. The addition of an OH- active contaminant to the well water did not effect
the rate of decomposition of the carbon tetrachloride.
The contamination levels of the moderately contaminated sample of well water from LLNL a
Superfund site, were reduced to less than those set by the California Primary Drinking Water Standards
by an x-ray dose of 150 krads. For the more highly contaminated LLNL well water sample the dose to
reduce the contamination levels to drinking water standards was estimated to be 500 krads based on the
expenmental data. The amount of x-ray radiation required to decompose the organic contaminants in an
aqueous solu ion is a strong function of the contaminants present and the exact chemical composition of
the solution. In principle, the rate coefficients which were determined from the data can be used to predict
the dose level required to destroy mixtures of multiple VOC contaminants and OH- scavengers.
Experiments with high concentrations of TCE and PCE are being completed to determine reaction
by-products Preliminary analysis of the results showed no evidence of chlorinated hydrocarbons when
he TCE or PCE concentrations had been reduced to below detectable levels. As with high energy elec-
tron beam destruction of TCE and PCE, low level concentrations of the aldehydes and organic acids are
expected.
X-ray treatment of organically contaminated aqueous solutions is a viable method for reducing the
contamination to acceptable levels when a large depth of treatment is desired or required such as for con-
taminants ,n thick streams of liquids (> 2 inches), barrels, or tanks. When a large depth of penetration into
the contaminated material is not required (e.g. thin streams of liquids), the bremsstrahiung x-ray converter
can be removed from the accelerator and the contaminated material treated directly with the high energy
electron beam. *'
REFERENCES
(1) Cooper, W.J., Nickelsen, M.G., Meacham, D.E., Waite, T.D., and Kurucz, C N High Energy
Electron Beam Irradiation: An Innovative Process For The Treatment of Aqueous-Based
Organic Hazardous Wastes, J. Environ. Sci HpaitK,, A27(1 ), 21 9-244.
FOR MORE INFORMATION
Vernon L. Bailey, Jr.
Titan/Pulse Sciences, Inc.
600 McCormick Street
San Leandro, CA, USA 94577
(510)632-5100
-------
THERMAL DESORPTION OF SVOC. VOC. AND PESTICIDE CONTAMINATED SOIL
AT THE PRISTINE FACILITY TRUST SITPRRFIJND SITE. READING. OHIO
Robert Shanks, Technical Supervisor, SoilTech ATP Systems, Inc.
94 Inverness Terrace East, Suite 100, Englewood, CO 80112, (303) 790-1747
Anthony J. Trentini, Site Manager, SoilTech ATP Systems, Inc.
800 Canonic Drive, Porter, IN 46304, (219) 929-4343
In September 1993, SoilTech ATP Systems, Inc. (SoilTech) mobilized their 10 tph
Transportable Anaerobic Thermal Processor (ATP) System to the Pristine Facility Trust
Superfund Site (Pristine) in Reading, Ohio to treat approximately 13,500 tons of SVOC,
VOC, and Pesticide contaminated soil and sediment. The SoilTech ATP System anaerobically
desorbs organic contaminants from a solid matrix at temperatures in excess of 900 degrees
Farenheight (°F). The principle products of this process are clean treated soil and vapor
condensate containing the organic constituents. SoilTech is operating a 25 gpm Waste Water
Treatment System at the Pristine Site to remove organic contaminants from the vapor
condensate. The treated condensate is added as quench water to the processed soils while the
organic phase will be sent for off-site disposal.
Site specific conditions that are presenting new challenges to SoilTech include limited
site access, adverse feed soil characteristics, and strict delisting criteria for the processed soil.
Mobilization logistics were extensive because the site had no road frontage and limited access
was available only through neighboring industrial facilities. The feed material is a wet clay
containing a high percentage of fines which poses significant material handling difficulties.
Samples of the feed soil indicate elemental sulfur in the range of 1 to 6 percent which
significantly increases the potential for high sulfur dioxide emissions; and corrosion of process
internals. SoilTech successfully met the performance criteria of 99.99% destruction and
removal efficiency (DRE) for organic contaminants in stack emissions required by the U.S.
Environmental Protection Agency. The low concentrations of individual organic
contaminants meant that addition of surrogate compounds to the feed was necessary to
demonstrate that the ATP System could meet the performance criteria. The soil delisting
criteria includes maximum total concentrations for 51 organic compounds and TCLP limits
for 9 inorganic compounds.
The ATP System, under normal operating conditions, concentrates organic contaminants
to the extent that compounds below detection limits in the feed soils can sometimes be
detected in the organic concentrate. During waste profiling activities, PCBs were
unexpectedly detected in the organic concentrate resulting in potential increased cost for off-
site disposal. SoilTech instituted a significant operational change that greatly reduced the
volume of organic waste generated for off-site disposal.
To date, SoilTech has processed and met the delisting criteria, without failure, for over
11,600 tons of site feed soils. The completion of processing, equipment decontamination,
and demobilization is expected to be March 1994. A technical paper will be available
subsequent to that time.
89
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Thermal Desorption/Base Catalyzed Decomposition (BCD)
A Non-oxidative Method For Chemical Dechlorination
Of Organic Compounds
Introduction
Thermal desorption has become an acceptable and effective alternative for the non-
oxidative treatment of organic contaminated soils, sediments and sludges Physical
separation of the contaminants from the media through indirect heated thermal desorption
results in lower volume off-gas which allows for contaminant recovery through condensation
of the organic compounds from the off-gas. The Base Catalyzed Decomposition (BCD)
Technology detoxifies and chemically decomposes contaminants by removing chlorine atoms
The BCD process can be combined with medium temperature thermal desorption (MTTD)
to dechlorinate high-hazard organics including polychlorinated dibenzo-p-dioxins (PCDD)
potychlonnateddibenzofurans (PCDF), pentachlorophenol (PCP), polychlorinated biphenyls
(PCB) and pesticides/herbicides. The combination of MTTD with BCD allows for meeting
the objectives of minimi/ing/ concentrating the organics requiring BCD, treating the
contaminated media for recycling as backfill, minimizing air and water discharges and
recovering the dechlorinated organic compounds for utilization as a fuel supplement in an
industrial boiler. *v
EPA's Risk Reduction Engineering Laboratory (RREL) in Cincinnati Ohio
developed and patented the BCD technology. RREL initiated research to develop
innovative alternatives for treatment of chlorinated organic compounds in 1980 The
challenge was to modify catalytic transfer hydrogenation process extensively utilized in the
chemical process industry to result in a cost effective commercial process which would meet
applicable regulatory standards. In January, 1989 experimental results confirmed that a
process for chemical dechlorination had indeed been developed on a laboratory scale «
The Federal Technology Transfer Act (FTTA) allows private sector firms like ETG
Environmental, Inc. ("ETC") and Separation and Recovery Systems ("SRS") to conduct BCD
and other technology commercialization in conjunction with the USEPA.
ETG/SRS has worked with RREL/USEPA since 1991 to develop the SAREX*
Therm-O-Detox system to be used with the BCD process on a commercial level Through
a cooperative effort between the EPA SITE Program, EPA Region 4, and the NC-DEHNR
a BCD technology demonstration was conducted by ETG and SRS at the Koppers
Superfund site in MorrisvUle, North Carolina in September, 1993.
Methodology
The principle of the BCD process is the utilization of hydrogen radicals (Acceptor-H)
generated from a hydrogen donor to completely replace the chlorine ions in the chlorinated
hydrocarbons^ >. The key operating vairables for the reactions are temperature, base catalyst
and hydrogen donor concentrations.
90
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Indirect heated thermal desorption of organics from contaminated soils and sludges
is well studied and documented(3). Indirect heated systems transl'er heat from steam, hot
oil, molten salt or electricity through metal surfaces to the waste materials. A sweep gas
with low oxygen content is used to physically separate the organic contaminants from the
media (e.g. soil) through thermal desorption. Desorbed organic compounds are condensed
and recovered. Carbon adsorption may be used to polish the off-gias prior to discharge into
the atmosphere. Particuiate carryover is minimized due to the decreased volume of exhaust
gas. Condensed water is recycled to the treated media for cooling, dust suppression, and
to provide a moisture content suitable for backfill compaction.
ETG/SRS have observed through their own field experience, as well as published
information, that heat transfer to the waste and degree of waste mixing are two of the most
critical factors for effective thermal desorption. Increased mixing 'will lead to the reduction
of material residence times. A thermal desorption system that processes a material quieldy
and thoroughly also has less chance for thermal decomposition of organic compounds or
forming coke in the system caused by higher hydrocarbon concentration from the feed
material A continuing trend is to increase the process temperature of the thermal
desorption system to a higher range (750°F to 950'F) defined by ETG/SRS as medium
temperature thermal desorption (MTTD), for the removal of heavy organic and chlorinated
organic compounds.
The SAREX* Therm-O-Detox* system as shown in Figure 1 includes an indirect
heated MTTD unit to physically separate moisture and organics from the media, an
extensive vapor recovery system including condensing unit(s) and carbon adsorption, and a
BCD liquid tank reactor (LTR) unit. The contaminated/screened materials are fed to a
feed hopper and conveyed through an enclosed hopper to the solids reactor (MTTD).
Dechlorination agents are added in the feed conveyor to allow premixing with the
contaminated media.
The indirect heated MTTD can be controlled to a desirable temperature and
residence time as required by the BCD process. Vapors are discharged to the scrubbing and
condensing system and a carbon polishing system prior to atmospheric discharge. Clean
media is discharged to an enclosed cooling conveyor where condensed, polished water from
the vapor recovery system is recycled and utilized to cool the media, as well as to control
dust and produce a material with proper moisture content for compaction as on-site backfill.
The organic contaminants recovered from the vapor recovery system are sent to the
BCD LTR. The LTR is prepared to treat contaminants by adding base (i.e., sodium
hydorxide), a catalyst, and a hydrocarbon which serves as the reaction medium and the
hydrogen donor. The LTR contents are heated to a temperature of 320° - 340'C (610 -
650°F) to effect dechlorination of contaminants. After dechlorination reactions are
completed, the LTR contents can be reused to treat other contaminants with chemical
additions or used as a fuel supplement in an industrial boiler such as a cement kiln.
91
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The BCD chemistry^ in the LTR is illustrated as follows:
620T-650°F
Catalyst
->R-H+NaCl+R"
9 4 r» o ^ shown can be,any halogenated compound such as PCDDs, PGDFs PCBs
2,4-D or 2,4,5-T. In principal R is a hydrogen donor whose oxidation potential is sufficiently
low to generate nucleophilic hydrogen in the presence of base Na+ (sodium hydroxide) and
at temperatures between 250 - 350 C Under these conditions, chlorine on R-C1 is replaced
Si -H° P£?1Ce R"? Wlt^.1°SS °f hydr°gen from R> to R" ^ the fonnation of sodium
chloride. Tins reaction achieves complete dechlorination of chlorinated compounds.
The MUD/BCD system has the following advantages:
• The unit has a high heat transfer surface area resulting in high heat transfer
g t nci cn,cy«
• The MTTD unit provides complete local mixing action exposing most of the
particles of the process mass to the heat transfer surface. This reduces the
dependency of heat movement on the thermal conductivity of the process.
• System equipment components are proven effective and commercially available
No new or experimental equipment is required.
• The MTTD system can be modified to incorporate stabilization/fixation additives
if heavy metals are present.
• The uniform bed conditions will promote direct surface thermal desorption
comparing to the ineffective diffusion phenomena when the particles are stuck
together in lump or cake. The homogenous bed will result in the reduction of the
retention time required to meet the treatment standards.
• The MTTD unit can process sludge, sediment and clayey soils directly to meet
treatment requirements. No pre-drying is required.
• There is no large volume of sweep gas flow through the MTTD indirect heat
unit, resulting in true, non-oxidative physical separation. The off-gas can be
S^f/Rnr? T the ,^quirement of an afterburner (incinerator). The
MTTD/BCD system will have les? environmental fmpscj and permitting
rejELUirements. f —*
92
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• BCD reagents are inexpensive and do not require reuse, in contrast to other
dechlorination processes (APEG/KPEG).
• Lower cost than incineration and other higher temperature thermal desorption
systems.
. The higher material temperature and uniform material t>ed will assure the higher
removal rate for high boning point contaminants.
SITE Demonstration
In late 1992, ETG/SRS was contacted by the USEPA Office of Research and
Development (ORD) to demonstrate the MTTD/BCD technology using the SAREX*
Therm-O-Detox* system at a Superfund site in Morrisville, North Carolina under the
Superfund Innovative Technology Evaluation (SITE) program(5). The objectives of this
demonstration are listed below:
• Assess the effectiveness of the MTTD/BCD process in treating PCP, dioxins, and
furans to levels below those stated in the ROD.
• Determine if treatment residuals (air, water, oil) also meet appropriate clean-up
levels.
• Develop information to evaluate the cost-effectiveness of MTTD/BCD for future
Superfund projects, RCRA corrective actions, or voluntary remediation projects.
The Koppers site in Morrisville was a former wood preserving operation utilizing the
Cellon process, which involves pressure treating of wood with PCP and subsequent steaming
for wood preservation. The rinsate was placed in unlined lagoons where leaching into the
soil occurred. Contaminants included PCP in excess of 10,000 ppm, and lesser
concentrations of dioxins and furans.
Following completion of bench-scale testing and approval of the Quality Assurance
Project Plan, an MTTD/BCD system capable of handling 0.25 - .5 TPH throughput was
mobilized. The equipment was placed into a portable containment pad with approximate
dimensions of 60' x 80'. Soil was excavated from the documented "hot spots" on the site and
hand screened to less than 0.5 inches and placed in 55 gallon dirums for transport to the
processing area.
Results
One test ran was completed per day during the demonstration. The operating
parameters were recorded (drum weight, reagent dosage, retention time, operating
temperature, contaminant concentration, etc.) throughout the demonstration. Each of seven
total test runs lasted between four and eight hours and processed. 2,000 to 4,000 pounds of
feed per run(7). Samples of treated solids, air, water, and organics were collected during
93
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, Preli^ary results look encouraging and appear to be similar to the bench-scale
treatabihty results. Final results will be reported in the USEPA's SITE Demonstration
summary Report expected to be released in 1994.
x^rr SCale analytical testing on the contaminated soils indicated that the
MTTD/BCD process was very successful in dechlorinating the PCP, dioxins and furans. As
indicated in Table 1 destruction and removal efficiencies of 99.99% or greater were
achieved in most cases®. These results indicate that the treatment standards of 95 ppm for
PCP and 7 ppb for dioxins specified in the Morrisville, North Carolina ROD will be easily
JJLLCL*
Table 1
Treatability Test Results For A Soil Sample From
The Koppers Site, Morrisville, NC
Soil Following
F Treatment
Percent | Treatment
Removal Standard
Contaminant
2,3,7,8 TCDD equivalent
94
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Based on the operating data and equipment efficiency monitored during the USEPA
SITE Demonstration, ETG/SRS have developed preliminary cost estimates for the
MTTD/BCD system of $150 - $250/feed ton for sites containing more than 10,000 yd3 of
contaminated soils. Systems capable of handling 5-15 TPH are currently under construction
and are available immediately after a 2-3 month (typical) treatalbility study. Treatability
bench and/or pilot-scale studies typically cost $20,000 - $200,000. System economics are
determined by a number of factors including volume and concentrations of contaminated
material, required clean-up standards, utility availability, physical, nature of contaminated
wastes (necessity of pre-treatment), and permitting requirements. Due to the varying nature
of these factors, treatability studies are strongly recommended.
Conclusions
Medium Temperature Thermal Desorption (MTTD) is a proven commercial process
to physically separate organic contaminants (VOCs, SVOCs, Coal Tar, etc.) from
contaminated media (soil, process sludges) by indirect heating. The low volume of off-gas
results in condensation and ultimate recycling of the organic contaminants. The technology
has proven to be technically and economically effective at a number of oil refining and
chemical industry sites for soil and process sludge treatment.
MTTD can be combined with Base Catalyzed Decomposition (BCD) to chemically
dechlorinate high-hazard organics such as chlorinated dibenzodioxins and furans,
polychlorinated biphenyls (PCBs), pentachlorophenol (PCP), and pesticides/herbicides (2,4-
D 2,4,5-T, silvex, DDT, DDD, lindane, etc.). Bench-scale testing indicates destruction and
removal efficiencies in excess of 99.9% can be achieved. For a site containing greater than
10,000 yd3 of contaminated soils, the estimated remediation costs of $150 - $250/ton of feed
are applicable for a 5-15 TPH system.
References
1. Rogers, CJ.; Kernel, A.; Sparks, H.L.; USEPA/RREL; The Development of
Catalytic Transfer Hydrogenation Process for the Destruction of Toxic and
Hazardous Compounds; unpublished paper.
2. Rogers, CJ.; Kernel, A; Sparks, H.L.; Haz Pac '91, Hazardous Waste
Management in Pacific Basin. Randol International, Ltd., Golden, CO, 1991.
3. Shieh, Y.S.; ETG Environmental, Inc.; Thermal Desorption - A Physical
Separation Method to Treat Soils and Sludges Contaminated with Organic
Compounds; paper presented at 1993 HMCRI Superfund XTV Conference,
November 30 - December 2, 1993.
4. Rogers, C J.; Kornel, A; Sparks, H.L.; Method for the Destruction of Halogenated
Compounds in a Contaminated Medium. Patents: Number 5,019,175 (May 28,
1991); 5,039,350 (August 13, 1991), and 5,064,506 (November 12, 1991),
95
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5.
6.
7.
USEPA, OSWER,; SITE Program Fact Sheet, Demonstration of the Base
Catalyzed Decomposition Technology and SAREX* Therm-O-Detoxtm System-
August, 1993. 3
The PRC SITE Team, Final QAPP for Base Catalyzed Decomposition (BCD)
Technology SITE Demonstration at Koppers Company, Inc., Morrisville, NC.
MiUer, B.H.; Sheehan, W.J.; Swanberg, C.J.; Separation and Recovery Systems,
Inc.; The Base Catalyzed Decomposition (BCD) Process for Treating Heavy
Halocarbons in Soils and Sludges; paper presented at 1993 HMCRI Superfund
XTV Conference; November 30 - December 2, 1993.
For more information, please contact:
Yei-Shong Shieh, Ph.D., P.E.
ETG Environmental, Inc.
660 Sentry Parkway
Blue Bell, Pennsylvania 19422
(610) 832-0700
CONTAMINATED
MATERIALS
OR SCREENED SOILS
VAPOR DISCHARGES
DECHLORINATON
REAGENTS
FEED CONVEYOR
VAPOR RECOVERY SYSTEM
OIL WATER CONDENSING
SCRUBBERS SCRUBBERS UNIT
TO 1
ATMOSPHERE I
BCD SOLIDS REACTOR
MEDIUM TEMPERATURE
THERMAL DESORPTION
(MTTD)
ON-SITE BACKFILL
OR
OFF-SITE DISPOSAL
DECONTAMINATED SOUDS
CONTAINER
COOLING WATER
SAREX8 THERM-O-DETOX8 SYSTEM
BCD PROCESS
Rev. | 4.5 | Drown By: M. Brocker | Dote: 2/4/94~
Dwg. f
4010
FIGURE 1
96
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RADIATION PROCESSING OF GRQUNDWATER FOR CHLORINATED SOLVENTS WITH AND
WITHOUT COMBINATION OF OZONE
Peter Gehringer, Helmut Eschweiler, Walter Szinovatz, Helmut Fiedler and Gerald Sonneck.
Austrian Research Centre Seibersdorf, A-2444 Seibersdorf, Austria.
Phone number: 01143-(2254)-780-0
INTRODUCTION
Of the various organic contaminants found in groundwater the widely used industrial solvents
trichloroethylene (TCE) and perchloroethylene (PCE) are the most common. However/to a minor
extent also 1,1,1-trichloroethane and its decomposition product 1,1-dichloroethylene (DCE) have
been detected. The conventional methods for the treatment of such polluted water, i.e. adsorption
onto activated carbon do remove the contaminants from the water but they do not destroy them.
This might often result in a mere displacement of the problem from the water to the carbon.
An attractive solution of this problem offers the mineralization of the contaminants by oxidation
directly in water because such a process remediates the water and disposes of the contaminants in
a single step. At present on a technical scale the only oxidant for trace amounts of these chlorinated
compounds in water is the hydroxy free radical (OH).
Hydroxy free radicals are generated in water by the so-called Advanced Oxidation Processes
(AOPs). Application on a technical scale has been reported for the combinations ozone/UV,
ozone/hydrogen peroxide and hydrogen peroxide/UV. All these AOPs have in common that the OH
originates from one single source only (ozone or hydrogen peroxide). An AOP based on the
combination of ozone with ionizing radiation generates the hydroxy free radicals from two sources:
- directly from the water to be remediated by water radiolysis and
- from ozone decomposition promoted by the reducing species formed during water radiolysis.
The resulting OH concentration is significantly higher than those of the above mentioned AOPs.
The combination ozone/electron beam irradiation, therefore, is especially apt for the remediation of
groundwater containing pollutants in trace amounts only - a situation which often occurs with
chlorinated solvents.
METHODOLOGY
The ionisation and excitation of water molecules by high-energy radiation are known to result in
the formation of free radical and molecular species. For low level contamination of groundwater
« 1 mg.dm'3) just the highly reactive free radical species OH, e" and H are of interest for pollutant
decomposition. The pollutants compete for the free radical species with the natural solutes and the
oxygen contained in the water.
In air-saturated groundwater containing the chlorinated compounds as micropollutants most of
the solvated electrons e" and the hydrogen radicals H are scavenged by the oxygen present forming
superoxide radical anion and hydroperoxy radical H02, respectively. The latter is in an acid-base
equilibrium with the superoxide anion (pK = 4.7). At the usual pH-values of groundwater the
equilibrium is shifted towards the superoxide anion i.e. most of the reducing species are converted
into the superoxide anion which is a rather inert radical. It certainly does not react with PCE, TCE,
DCE and 1,1,1-trichloroethane. Its probable fate is its disproportionation into H2QZ and 02. Roughly
speaking only OH remains as active species for pollutant decomposition in irradiated groundwater.
In other words more than 50 % of the radiation energy is wasted.
97
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Under the conditions given and as long as the nitrate concentration is low only bicarbonate ions
S6S TT5 for OH accordi"9 to their high concentration. For nitrate concentrations
rn t h i 3 W Ppn\scaven9in9 of seated electrons and subsequent formation of nitrite
cannot be longer .gnored. N.trite scavenges OH radicals very effectively and considerably
worsens the conditions of pollutant decomposition. Moreover, nitrite itself belongs to hazardous
r?™ h 9 IT/' C°nfquentlv a process for sroundwater clean-up based on irradiation
fJ "« H I8 ? P"ed f°r dnnkm9 W3ter Production because of exceeding the limit values of
as well as hydrogen peroxide in drinking water.
n™™n,h ishcompletelv Chan9ed when tn« water irradiation is performed in the presence of
ozone. On the one hand, ozone is known to oxidize nitrite to nitrate very fast; on the other hand
ozone also reacts w,th hydrogen peroxide. Therefore, a residual ozone concentration present after
the jrad.at.on mdicates that inadmissible amounts of nitrite as well as hydrogen peroxide do not
OX I ST.*
nromnth aCtS M additional OH source ™ it decomposes into OH; the decomposition is
promoted by the reducing spec.es formed during water radiolysis. In this way almost the whole
radiation energy is used for OH generation.
miw-th ****** aqueous solution (f|9ure 1>: the 02/03 mixture from the ozone-generator is
mixed w,th purified water at elevated pressure. In the gas seperator the excess O2 is removed. The
ozonewater is then m.xed with the polluted groundwater and irradiated with fast Electrons
U compress or
oiooa—
destruction
COJiTAMINATED
GROUNDIATER
electron beam
accelerator
coolaaxt
irradiation.
chamber
Figure i. Prototype for continuous ozone/electron beam irradiation treatment of water.
98
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RESULTS
In a water work south of Vienna groundwater contaminated with about 50 ppb PCE and about
5 ppb TCE is purified by activated carbon filtration. The plant flow is 300 dm3/s (about 6.9 million
gallons a day), the total capital cost amounted to 2.5 million US dollar, the operating cost are
expected to be around 4-5 cents per m3 treated water.
Experiments applied with this groundwater have demonstrated that 250 Gy in combination with
3 ppm initial ozone concentration reduce the PCE below 10 ppb (see figure 2) and TCE below
1 ppb. Based on these results an appropriate ozone/electron beam facility would amount to about
2.35 million US dollar with operating cost of about 8 cents per m3 treated water.
Among the chlorinated ethylenes PCE is most resistent against OH attack, its decomposition
need relatively high radiation doses together with relatively high ozone demand, therefore. On the
other hand adsorption onto activated carbon is best for PCE. That means worst conditions of
oxidation have to compete with best conditions of adsorption - and this is reflected in the cost.
However, the advantages in improved water quality and reduced environmental pollution may
outweigh purely economic considerations in some areas.
60
J_
Initial Os-conc.
T 1 ppm. Oa
^ Z ppm. Oi
O 3 ppm. Oi
D
BOO
Figure Z.
Decomposition of PCE (O,n,°)
and DCE (v,A), respectively in
jroundwater (297 ppm bicarbonate,
18 ppm nitrate, 1 ppm DOC) l>y
ozone/electron beam irradiation
treatment
Figure 3.
Decomposition of TCE in gronnd-
iraier (402 ppm bicailxraate,
30 ppm nitrate, 0.5 ppm DOC) by
ozone/electron beam itrradiation
treatment.
The unit of the radiation dose is Gray (Gy). IGy = 1 J,k;~
99
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Also contained in figure 2 is the decomposition of 10 ppb DCE in relation to radiation dose and
initialozone concentration. DCE is the most toxic compound among the chlorinated ethylenes
mentioned; ,ts limit concentration in potable water is restricted to 0.3 ppb, therefore. Regarding the
competion conditions between activated carbon and oxidation the inverse situation to PCE is valid
e T°9ether With the required low limit concentration the
should be also economically the better alternative.
In the drinking water works of Niederrohrdorf near Zurich, Switzerland an ozone/UV-combination
r,?r0 W3ter remediation contaminated with about 100 ppb TCE was installed by '
about 0^' nnTnnr TH6 9r°und,Water ™!tain3s about 402 PPm bicarbonate, 30 ppm nitrate and
ozte " 18° "^ ** * ™ "***»
TABLE 1. COST EVALUATION OZONE/UV VERSUS OZONE/ELECTRON BEAM
(FOR GROUNDWATER REMEDIATION)
i^—^^-•j^—. —-^^^•-•^^•j
Process and Cost Parameter
for 810 m3/h = 500 million gallons/day
0,/UV radiation
0,/electrons
Radiation source
Energy consumption
03-demand
02-consumption
Energy consumption
Energy (total)
Capital requirement
Radiation source
Ozone generator
Capital cost (9.5 %
interest ave., 10 years)
Hourly charge (8500 h/yr)
Variable cost
Electric power (15 C/kWh)
Oxygen (45 0/m3)
Total cost
UV-medium pressure
35 kW UVC
234 kWh
5.85 kg/h
50 m3/h
50 kWh
284 kWh
675 000 $
420000 $
175000 $/yr
21 $/h
42.6 $/h
22.5 $/h
86 $/h
800 kV-accelerator
67.5 kW
135 kWh
2.25 kg/h
20 m3/h
20 kWh
155 kWh
1 700 000 $
186000 $
302000 $/yr
36 $/h
23.1 $/h
9.0 $/h
68 $/h
n,o? KWS dfcomP°SItion °f about 100 ppb TCE in simulated Niederrohrdorf water by
ozone/electron beam .rrad.at.on treatment as a function of the radiation dose and the initial ozone
concentration.^ contrary to the ozone/UV-combination which needs about 6-7 ppm S ozone
aoa^alreSrw£ Jj? V-> ^ ^ ™™ 1° PPb the ozone/el^tron beam treatment meets this
goal already with about 2 ppm initial ozone concentration. Using 5-6 ppm initial ozone concentration
100
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in the ozone/electron beam combination would result in a residual TCE concentration near 1 ppb,
almost one order of magnitude better than the ozone/UV-combination. Both results are clear
indications for the higher OH free radical concentrations yielded by the ozone/electron beam
combination.
The cost comparison of the two processes is shown in table 1 and is based on the following
considerations. Both processes use ozone and radiation, both processes produce ozone water with
a high ozone concentration and add it to the polluted ground water before irradiation. Maintaining
that in both processes the ozone water production can be performed exactly in the same way
reduces the cost comparison of the two processes to a cost comparison of the radiation sources
and the ozone production. According to the capital cost of an electron beam accelerator the
ozone/electron beam process should be preferably applied to high throughput capacities. Therefore,
a throughput of about 5 million gallons a day was chosen for the evaluation.
As the capital cost for an electron beam accelerator are rather high - in the present case 3 times
more than the UV-lamps - the hourly charges are $ 36 to $ 21 only. However, the operating cost
show the opposite situation according to the lower ozone demand and the lower energy
consumption of the accelerator. As a consequence the resulting total cost are in favour of the
ozone/electron beam process!
CONCLUSIONS
The combination ozone/electron beam irradiation is unique among the AOPs because of two
outstanding features: (1) the energy absorption proceeds via the water to be remediated initiating
(2) two different OH generation processes simultaneously. Compared to -the other AOPs a higher
OH concentration results which causes a lower residual pollutant concentration (when the same
ozone concentration is considered) or less ozone consumption (when the same residual pollutant
level is considered). Moreover, a high efficacy at low pollutant levels exists bringing about
throughput capacities of 5-6 million gallons a day and more at competitive cost. Accordingly the
ozone/electron beam irradiation process is especially apt for the remediation of low level
contaminated groundwater.
For more information: Dr. P. Gehringer, Austrian Research Centre Seibersdorf,
A-2444 Seibersdorf, Austria. Phone number: 01143-(2254)-780-3434.
101
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THE OXYJET TECHNOLOGY: AN INNOVATIVE APPROACH FOR
THE WET OXIDATION OF HAZARDOUS WASTES
Santiago Gasso(1), Margarita Gonzalez'1', Esteban Chornet(2)
and Jose M. Baldasano"'
m Institute de Tecnologia y Modelizacion Ambiental (ITEMA), Universidad Politecnica de Cataluna
(UPC). Apdo Corrects 508, 08220 Terrassa (Barcelona, Spain), ftel. 34 O3 739 839O)
^Kemestrie Inc., 2255 Rue Vermont, Sherbrooke, Quebec J1J 1G9 (Canada)
INTRODUCTION
The potentially harmful effects of organic substances present in many hazardous wastes have
generated interested in establishing effective treatment technologies for these wastes. Technologies
used for the treatment of such wastes should preferably accomplish transformation of the hazardous
components to innocuous end products.
Wet Oxidation is an attractive alternative for the treatment of hazardous wastes with relatively
high nonbiodegradable organic material content (COD ranging from 10 to 200 g/l). This treatment
consists of oxidizing organic and inorganic compounds in an aqueous solution by means of molecular
oxygen at elevated pressures and temperatures. The temperature in the reactor depends on the nature
of the organic compounds to be destroyed and the degree of oxidation required, and it ranges from 175
to 325 °C. The total pressure to be applied (2 to 20 MPa) is the sum of the steam pressure and the
necessary oxygen pressure to reach a sufficient concentration of oxygen in the aqueous phase (2,7).
The oxidation end products may be inorganic salts, simpler forms of biodegradable compounds (mainly
consist of low molecular carboxylic acids) or may lead to complete oxidation to carbon dioxide and
water (5,8,14,15).
Wet oxidation is an established technology which has been demonstrated to be effective in
treating a wide variety of hazardous organics contained wastes (6). It has been used extensively for
the treatment of: hazardous waste (chemical and pharma-chemical industry), landfill leachate, paper-mill
black liquor, petrochemical, activated carbon regeneration, cyanide wastewaters, herbicide and pesticide
wastes, etc. (1,4,10,13).
In the conventional wet oxidation technologies, like ZIMPRO (16,17) or WETOX (12) processes,
the mass transfer is often the controlling step (depending on the relative mass transfer and intrinsic
kinetic rates). This fact besides the relatively moderate temperatures of wet oxidation results in long
reaction times (from 30 to 60 minutes).
Oxyjet technology is an innovative wet oxidation system based on jet-mixers that was initially
developed by Chomet (3). The Oxyjet process consists of a high interfacial area contactor placed at
the entrance of a tubular reactor, followed by a secondary spray chamber where additional oxidant (i.e.
O3 or H2O,,) can complete the oxidation when needed. One of the special features of the Jet-Mixer
placed in Oxyjet is contacting gas and liquid in such a way that the kinetic energy of the gas is used
to disperse the liquid into fine droplets. With this configuration the gas-liquid interfaciai area is
enhanced, the mass transfer resistance is minimized and the oxidation process is fully governed by the
kinetics of chemical reactions. The net effect is that the residence times required in the Oxyjet system
are smaller than in conventional bubbling or stirring technologies (8).
This new approach was tested in a pilot-scale plant. The treatment capacity of this experimental
unit ranged from 0.1 to 0.3 l/min (1.7-W6 - 5-1Q-6 m3/s) of aqueous wastes. The experiments performed
in the pilot plant proved that wet oxidation process using compact jet-mixers reactors is a promising
technology for the treatment of organic industrial wastes. It should be noted that in these experiments,
102
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the same reaction extent was attained with retention times about ten times lower than those required
in conventional wet oxidation technologies (9).
An Oxyjet Demonstration Unit has been designed and constructed. Due to the special
characteristics of the Oxyjet technology, this demonstration unit is a necessary previous step to a full
scale development of this process in order to establish the most favourable conditions, select the most
suitable equipment and materials and assess the reliability of this new approach.
The purpose of this paper is to illustrate the application of the Oxyjet technology to treatment of
a high strength industrial waste. This is done through the review of the main engineering feature and
economic evaluation of the ODP, currently in operation, for the treatment of a problem waste stream
produced in an existing chemical facility.
METHODOLOGY
The ODP has been installed in Sant Celoni's site (Barcelona, Spain) and has a treatment
capacity of 3 l/min of waste (50-10"6 m3/s), with organic loads ranging from 20;000 to 200,000 mg/l of
COD. It is a compact industrial plant with a modular and versatile structure. This implies that the ODP
has been designed for wide working conditions depending on the specific characteristics of the organic
aqueous waste to be treated. The Oxyjet process consists of four zones: 1) feeding an organic waste
and oxygen to the reaction system, 2) mixing of both streams, 3) reaction in an aqueous phase
between oxygen and organic compounds, and 4) separation of gas and liquid phases. The principles
of operation can be best understood by referring to the Oxyjet process diagram. Figure 1 shows this
process flowsheet.
I '^ j^ w i sirI
\TU%C-/VD1~~VD2"1 I
E2 V
To biological
Treatment
Fig. 1 Diagram process of the Oxyjet Demonstration Plant
Hazardous waste, as an aqueous solution, is fed to the Oxyjet process from an agitated storage
tank (T1) through a high pressure diaphragm pump (P1). The pump has a nominal capacity of 180 l/h
(5-10"s m3/s), and a maximum discharge pressure of 20 MPa. The pressurized liquid passes through
a heat exchanger (E1) which preheats it to a maximum of 260 °C using a hot organic heat-transfer
103
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fluid. The heat exchanger is designed with one pass on the shell and four passes on the tube side. The
heat-transfer fluid flows through the shell side and waste in the tube side.
At the entrance of the Jet-Mixer (M1), the incoming preheated liquid encounters the injected
oxygen. One special feature of the Jet-Mixer is that the kinetic energy of the gas is used to disperse
the liquid into fine droplets. The technological aspects of jet-mixers devices were initially described in
previous publications (11,3). The Jet-Mixer used in this work is an advanced version of the same
principle.
The two-phase mist formed at the jet mixers device enters a tubular reactor (R1). In the reactor,
temperatures are increased to needed levels (between 200 ° C and 350 ° C) through both indirect heat
exchange with organic heat-transfer fluid and the heat released exothermically by the oxidation
reactions. For aqueous wastes having COD values greater than 10 to 15 g/l, additional external energy
is only required during start-up. The tubular reactor consist of a shell, 0.8 m in width and 1.6 m high.
Three concentric coils are placed inside the shell. The three coils have a total length of 174 m. The
heat-transfer fluid flows through the shell side and the two-phase mist moves inside coils. This
configuration gives operational flexibility to the reactor system, since cojls can be easily added or
removed. The tubular reactor had to a back-pressure regulating valve (VR1). The pressure drop through
this valve ranges from 3.2 to 15.2 MPa.
The hot oxidized liquid waste is cooled, after valve (VR1), in a heat exchanger ,(E3). The
pressure is dropped to atmospheric by two control valves (VD1 and VD2) and the liquid and
non-condensible gases are disengaged in the separator drum (S1) and discharged separately. The
treated aqueous waste is collected in a storage tank (T2). The residual gas, mainly composed of
oxygen added in excess, carbon dioxide and water, is released, in the OOP, to the atmosphere.
Besides the equipment described above, the Oxyjet system has as auxiliary facilities the oxygen
supply plant and the heat transfer circuit.
Oxygen Supply Plant. Liquid oxygen is received and stored in a low pressure (0,8 MPa)
cryogenic tank with a capacity of 30001. From this tank, oxygen is pumped with a positive-displacement
pump through a vaporizer (atmospheric heat is used to vaporize the oxygen) and introduced into a high
pressure (20 MPa) receiver with a capacity of 840 Nm3/h. Oxygen is injected in the Jet-Mixer at specific
flowrates and pressures, which are controlled by a control loop composed of: a PID controller, a
mass-flow meter, and a control valve.
Heat Transfer Circuit. The heat needed to preheat the feed and trigger the oxidation is
transferred via a synthetic, organic heat-transfer fluid which, is moved by forced circulation with a
centrifugal pump, to the heat exchanger (E1) and reactor (R1). The fluid is heated by seven electrical
resistances of 20 kW (total electric power of 140 kW). During operation, when excess of heat derived
from the reaction, must be removed the thermal fluid is cooled by a water-cooler heat exchanger. All
pipes and devices that compose the heat transfer circuit are adequately insulated against heat losses.
Instrumentation and Control. The temperatures are measured eleven points of the oxidation
process by temperature transmitters inserted into thermowells immersed in the aqueous phase. Eight
gauge pressure transmitters have been installed to measure and control the pressure in several zones
of the ODP. Flow rates for feed and treated aqueous waste are measured using magnetic f lowrneters.
All these parameters are measured on-line and recorded in a data acquisition system.
Laboratory Support. During operation, direct control is provided by the system instrumentation.
COD of feed and effluent are determined in-situ. Other waste analysis such as TOC and pH are also
performed periodically. Additional state-of-the-art analyses include: gas chromatography using a mass
selective detector (GC/MS), gas chromatography using with a flame ionization detector (GC/FID), gas
chromatography using with a thermic conductivity detector (GC/TCD) and high performance liquid
chromatography using with a UV detector.
104
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RESULTS
The OOP was designed and constructed in 1992. It was located in Sant Celoni (Catalonia Spain)
at an industrial site in January 1 993 and started-up in February 1993. Until September 1 993 the OOP
has been operated for 250 hours with a high-load phenolic waste generated in a phenolic resin
polyrr.enzat.on unit. The characteristics of the phenolic waste stream are-
• COD ranging from 120,000 to 170,000 mg/l
• Temperature about 20 ° C
• PH= 9
• Average waste stream generation rate 10 m3/week (2 rrvVhour)
was chosen because its treatment by means of existing biological
due '° rts Wgh organic material concentration and toxicity. Moreover its
be h ", C°f f? 'Ve-dUe t0 JtS Ngh Water C0ntent Wet oxidation is a s^able op ion
because the bIOlog,cal mh.b.tion is reduced and energy recovery from the relatively high COD waste
Lnnn eorSf n^nta'-W?r^r?P C°nditi°nS and results "* P^ented In Table 1 A significant
amount (>90%) of the mrtial COD can be eliminated at the most severe operating conditions (ie
temperatures h,gher than 305-C and pressures greater than 16 MPa). At lower sevens e'
temperatures lowerthan 300 °C and pressures of 15 MPa), the COD reduction ranges from 35 to 70%
h SS H TH UCt'°n (Te tha" "%) °f the initial °r9anic """Pounds (expressed as phenol)'
is achieved during the wet oxidation process at the severities studied.
'f utS °bSerVed dUring aqueous oxidation are in agreement with the
in l.qud phase proposed in the literature (5,14,15). Basically the wet oxidation
GCD .v i f ?h 9e 7'f U'!S (initia' Phen°'S) l° Carb°n dioxide (which was confirmed by
bv I^LC/a?V I i° ^f ?"? ? an? STTa"er oxygenated °W™ molecules (which were detected
V V ! L ,6 "qUl^ P^Se)- TheSe Sma"er °rganic sPecies remaining in solution consist
trr Tir,aClf ^Ch M f°rmi°' 3CetiC' °Xalie' etc') which a^e s^ oxidized
blode9radablllty of ^e feed waste is significantly increased during the wet oxidation
It should be noted that in the experiments carried out using the OOP the residence time
compnsed between 1 and 10 minutes, which is far below that of conventional
TABLE 1 EXPERIMENTAL DATA OF THE OXYJET DEMONSTRATION UNIT
'liquid
(l/h)
24
124
124
128
128
129
124
124
124
124
124
125
125
124
124
126
127
F3as
(l/min)
354
445
426
438
434
434
455
445
450
450
430
435
435
435
435
450
450
p
reactor
(MPa)
15.1
15.9
16.0
16.0
16.0
17.0
15.9
16.0
16.0
16.0
16.0
16.5
16.5
16.5
16.5
15.0
15.0
reactor
(fiC)
298
307
308
317
318
320
299
319
317
321
323
308
318
323
312
317
304
COD,
(mg/l)
145000
120000
120000
168700
168700
168700
168700
168700
168700
168700
168700
168700
168700
168700
168700
168700
168700
COD,
(mg/l)
67500
78000
59000
13900
14300
15000
110000
14000
11500
15600
12600
45000
70000
15750
13000
13400
12000
CODr
53.4
35.0
50.8
91.8
91.5
91.1
34.8
91.7
93.2
90.8
92.5
73.3
58.5
90.7
92.3
92.1
92.9
(mg/l)'
5000
4800
4800
12500
12500
12500
12500
14000
14000
14000
14000
6000
6000
6000
6000
6000
6000
C6HSOH,
(mg/l)
0.8
0.6
0.6
12.0
14.5
4.0
2.0
9.0
8
10
8
2
2
8
3
60
40
I I
rC6H5OH
100.0
100.0
100.0
99.9
99.9
100.0
100.0
99.9
100.0
100.0
100.0
100.0
100.0
100.0
100.0
99.0
99.3
105
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The total purchased equipment cost (PEC) of the demonstration plant installed in Sant Celoni
was of 214 600 USD. It should be noted that the oxygen supply plant and heat transfer system, taken
together, account for almost 70% of the total PEC of $214,600. Cost of jet mixer-and tubular reactor
represent only 10% of the PEC. The total capital investment for the OOP is 347,000 USD Capital
investment was divided in direct costs, indirect costs and working capital both were estimated based
on real data of the Oxyjet plant.
Operation costs of the demonstration unit are function of the combination of temperature,
residance time and oxygen needed for the oxidation, which is related to the organics present in the
aqueous waste. In our case the treatment cost of the waste has range from 6.5 to 19.5 PTA/I (0,05 to
0,15 USD/I). It should be pointed out that the cost to incinerate these wastes ranges from 40 to 60
PTA/I (0.31-0.46 USD/I). In a commercial unit; based on the experience ganed during the demonstration
step, costs lower than those mentioned would be achieved.
Investment and operating costs are given on the basis of December 1992 costs, at the exchange
rate of 1 USD equal to 130 PTA.
CONCLUSIONS
A demonstration unit based on the Oxyjet technology has been designed and constructed. It is
currently in operation and has a capacity to treat a wastewater rate comprised between 1 to 3 I/mm
(17-10-6 to 50-10-6 m3/s). In the design of the OOP, the Jet-Mixer and the tubular reactor present the
greatest degree of uncertainty, particularly because they involves a two-phase reaction where diffusion
and mixing can have a major role in the determining overall reaction rate. Therefore, it has been
necessary to install operational flexibility into the reactor system (i.e. the tubular reactor has been
designed so that reactors coils can be easily added or removed).
Moreover, the auxiliary systems, i.e the preheater and the thermal fluid circuits have been
designed with sufficient spare capacity in order to explore a wide range of oxidation conditions.
In addition to the need for flexibility and integrated design, it must be remembered that a
demonstration plant is a data gathering device. Therefore, the OOP has been equipped with adequate
instrumentation, laboratory support, and sample gathering devices so that all aspects of the process
can be confirmed.
The results obtained with nonbiodegradable phenolic wastewater have shown that under the OOP
configuration at the most severe conditions (temperatures around 310 ° C, pressures about 16 MPa and
with about 5 minutes as reaction times), it is possible to achieve 90% reduction of COD and 99%
reduction of initial compounds (expressed as total phenols).
In summary, this paper shows that for those wastes which are too diluted to be incinerated
economically and are not biotreatable, Oxyjet process is a feasible and economically attractive method
to reduce oxygen demand and to increase the biodegradabiiity of hazardous wastes.
ACKNOWLEDGEMENT
Financial support from the Program MEDSPA 91-1-E/014/E/01 of EEC, Junta de Residus
(Catalonia, Spain), Resinas Sinteticas, S.A. (Cataluna, Spain) and Argon, S.A. (Spain) is gratefully
acknowledged. Thanks are expressed to Manuel Pena and Teresa Lacorte for their technical and
analytical contributions.
REFERENCES
1. Avezzu, F., Bissolotti, G. and Collivignarelli, C. (1989). LandfillLeachate Treatment by means
of a Wet Oxidation-Biological Combined Process: First Results. Proceedings the 2nd
International Landfill Symposium-Sardinia '89. 20pp.
106
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2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
wAi' W" Re9enas> W- a"d Wiedmann, W. (1979). Design of Reactors for the
Wet Air Ox.dat.on of Industrial Waste Water by Means of Computer Simulation. Computers &
Chemical Engineering, 3, 161-165. 'A-*«e/o «
Chornet, E. and Jaulin, L. (1988). Oxidation of Wastewaters. U.S. Patent 4, 767, 543 Aug. 30.
Chowdhury A. K and Wilhelmi, A. R. (1980). Treatment of Spent Caustic Liquors by Wet
Oxidation. Presented at 8th Annual Industrial Pollution Conference. Sponsored by Water and
Wastewater Eqmpment Manufacturer's Association, Houston, 4pp.
Foussard, J., Debellefontaine, H. and Besomes-Vailhe, J.
Liquid Wastes: Wet Air Oxidation. Journal of'
Efficient Elimination of
2,
n J'M" Gonz^le2 M- Abatzoglou N., Lemonnier, J.P. and Chornet E
' .°xldatlon via Two-Phase Flow Reactors and High Mass-Transfer Reafmes
Industrial Engineering Chemistry Research, 31, (8), 2057-2062 " ransier Hegimes.
Gonzalez M., Baldasano J.M., Lemonnier J.P., Abatzoglou N y Chornet E (1992W
Wet Oxidation of Organic Aqueous Effluents via the Oxyjet System Proceedinas of 6th
International Solid Wastes Congress ISWA-ATEGRUS,
WA' fnd™Mml'A- R' !1 985)- Wet Air Oxidation-A Treatment Means for Aqueous
Hazardous Waste Streams. Journal of Hazardous Materials, 12, 1 87-200,
Jaulin, L. and Chornet, E. (1987). High Shear Jet-Mixers as Two-Phase
f PhenolinA^ous Media. The Canadian
- An
Conrn|//LT- "S Robey'^ ^83). Wet Air Oxidation for Hazardous. Waste
Control. Journal of Hazardous Materials, 8, 1-9.
Component ln Waste
spe* or9a*
Air Oxidation-An
to
Zimmermann, F. J. (1958). New Waste Disposal Process. Chembal Engineering, 25, 117-120.
107
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FULL-SCALE APPLICATION OF ADVANCED PHOTOCHEMICAL
OXIDATION TO GROUNDWATER TREATMENT
Christopher L. Giggy
Vulcan Peroxidation Systems, Inc.
5151 E. Broadway, Suite 600
Tucson, AZ 85711
(602) 790-8383
INTRODUCTION
Photochemical oxidation of organic contaminants in water has been studied since the
early 1900s. However, commercial photochemical oxidation systems became available as
recently as the early 1980s. The technology has been advancing rapidly since that time due
to aggressive research by several independent companies. To date, well over one hundred
treatment processes have incorporated photochemical oxidation equipment into the final
treatment design. Full-scale applications range from groundwater remediation at Superfund
sites to treatment of wastewater for reuse, and include organic contaminant destruction in
landfill leachates, tank bottoms, drinking water, stream condensate and chemical process
streams. A wide variety of organic contaminants have been destroyed including volatile
organic compounds (VOCs), semi-VOCs, aromatics, alcohols, ketones, aldehydes, phenols,
ethers, phthalates, glycols, pesticides, ordnance compounds, dioxins, PCBs, PAHs, COD,
BOD, TOC and most other forms of organic carbon. Photochemical oxidation is most
effective for contaminant concentrations below 500 mg/1, and is capable of destruction to
below the lowest detection limit.
A common application of photochemical oxidation is groundwater remediation.
While the type of contaminants varies between sites, the organic matrix often includes
halogenated VOCs. Therefore, enhanced destruction of these compounds has been the
primary driving force behind the advances in the leading commercial photochemical
oxidation system, the perox-pure™ Process developed by Vulcan Peroxidation Systems, Inc.
Improvements in equipment and process implementation during the last ten years have
resulted in as much as a 20 fold increase in the full-scale destruction rates for some
contaminants.
The latest generation of the perox-pure™ full-scale equipment was evaluated by the
EPA during a SITE demonstration in September 1992. Although more than eighty full-scale
perox-pure™ systems have been installed in the United States, Canada, Europe and the
Caribbean, the SITE demonstration afforded the opportunity for the EPA to verify treatment
results and evaluate all aspects of the perox-pure™ Process. The results of the SITE
demonstration are provided below along with treatment cost projections.
108
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METHODOLOGY
The perox-pure™ photochemical oxidation process utilizes high intensity broad-band
ultraviolet (UV) radiation and hydrogen peroxide (HA) to photolyze and oxidize organic
compounds present in aqueous media. Hydroxyl radicals, the active oxidant, are produced
by the direct photolysis of H2O2. The perox-pure™ UV lamps are designed to produce a
high intensity peak at 254 nm, the wavelength which results in the highest quantum yield
of hydroxyl radicals. The hydroxyl radicals attack organic molecules resulting in
dissociation. The reaction is aided by the direct photolysis of the organic molecule by the
UV light which breaks or weakens certain atomic bonds making the molecule more
susceptible to oxidation. With sufficient oxidation and exposure to UV energy, the reaction
by-products are carbon dioxide and water. There-are no air emissions or solid by-products
formed by the perox-pure™ Process. Neither are there toxic or hazardous reaction products
formed by the recombination of molecules as can occur in high temperature/high pressure
or air-phase oxidation systems.
A perox-pure™ Model SSB-30R full-scale system was used during the SITE
demonstration. This unit was chosen because it was small in size (5-feet long by 3-feet
wide by 7-feet high), provided an extended oxidation time at the planned flow rate of 10
gpm, yet had a hydraulic capacity of several hundred gpm so that higher flows could be
evaluated if desired. Ancillary equipment provided for the demonstration included a H,O,
storage and feed unit, and acid/caustic feed .systems for in-line pH adjustment and
monitoring.
The full-scale perox-pure™ equipment is a single skid mounted unit consisting of an
oxidation chamber, an electrical enclosure and a control panel. In the case of the SSB-30R
the oxidation chamber is made up of six horizontal sub-chambers, each housing one UV
lamp inside a high-purity quartz tube. The water to be-treated enters the lowest sub-
chamber and flows through the annular space between the chamber wall and the quartz tube
where it is exposed to the UV light. The water passes through each of the identical sub-
chamber in series. H2O2 is added at the influent to the first sub-chamber, and can be added
between each sub-chamber to provide a constant oxidant supply throughout the oxidation
chamber.
In photochemical oxidation reactors, the UV density, surface area to volume ratio
and turbulent mixing are of paramount importance. The oxidation chamber of the latest
generation perox-pure™ equipment, which was used during the SITE demonstration, has
been designed to optimize the parameters listed above. Various UV lamp types and sub-
chamber configurations are available to address the needs of the different contaminant and
water quality matrices. The SSB-30R chosen for the SITE demonstration has six sub-
chambers with one 5-kilowatt UV lamp inside. The chamber configuration is ideal for
treatment of low level VOCs in groundwater and produces effective turbulent mixing at a
minimum flow rate of 5 gpm. The design also allows for flexibility in power turn-down
capability and multi-point sampling while maintaining consistent UV density
109
-------
Oxidation reactions can be affected by factors other than the UV source and reactor
design. Process variables include contaminant type and concentration, water quality, pH
of the water, oxidant dosage and fouling of the quartz tubes. In most cases, bench or pilot-
scale testing is required to evaluate these parameters and provide a reliable full-scale system
design. The majority of these variables were evaluated during the SITE demonstration.
RESULTS
The SITE demonstration with the full-scale perox-pure™ System was conducted at
the Lawrence Livermore National Laboratories (LLNL) Site 300 Testing Facilities. The
groundwater selected for the study was contaminated with approximately 1000 jug/1 of
trichloroethene (TCE) and 100 jig/1 of tetrachloroethene (PCE). A detailed description of
the demonstration can be found elsewhere1.
Fourteen tests were conducted with the perox-pure™ equipment to evaluate the effects of
pH adjustment, H2O2 dosage^ and quartz tube fouling. The best treatment results were
achieved without pH adjustment (pH 8.0) using a H2O2 dosage of 40 mg/1. Higher H2O2
dosages reduced the treatment efficiency of the TCE and PCE. The lower pH values did
not effect treatment. The results from the best test (Test 8) are shown in Table 1 below.
As shown, the contaminants were destroyed to below the analytical detection limit by fist
sample time. It is likely that similar or improved contaminant destruction rates could be
achieved using a H2O2 dosage lower than 40 mg/1.
Testing was also conducted on the groundwater after spiking with approximately 150 /xg/1
each of chloroform, 1,1-dichloroethane (DCA) and 1,1,1-trichloroethane (TCA). The pH
and H2O2 dosages were not optimized for the spiked water, but were selected based on field
data available during the demonstration from the earlier tests on the unspiked groundwater.
Accordingly, pH adjustment to 5 was used along with a total H2O2 dosage of approximately
85 mg/1. The treatment results for the contaminants spiked into the groundwater are shown
in Table 1 below. As shown, the contaminant destruction proceeds rapidly towards the
detection limit. Destruction of the,contaminants to below the detection limit can be
achieved with additional oxidation time.
Other findings from the SITE demonstration were: (1) the perox-pure™ System met
California drinking water action levels (CADWAL) and federal drinking water maximum
contaminant levels for all of the contaminants tested at the 95% confidence level, and (2)
the automatic quartz tube wiper employed by the perox-pure™ System was effective in
keeping the tubes clean for consistently high performance.
110
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TABLE 1. perox-pure™ TREATMENT RESULTS FROM SITE DEMONSTRATION
Contaminant 0*g/l)
Unsoiked Groundwater
Trichloroethene
Tetrachloroethene
Soiked Groundwater
Chloroform
1 , 1 -Dichloroethane
1,1, 1-Trichloroethane
, Oxidation Time (rnin.)
0
1300
150
150
160
110
0.063
<1
<1
—
..__
—
0.25
89
23
84
0.75
36
<5
47
1.5
14
7.8
The treatment costs associated with the perox-pure™ Process for both the spiked and
unspiked contaminant concentrations from Table 1 are shown iii Table 2 below. In each
case, the projections are for contaminant destruction to the CADWALs at a flow rate of 50
gpm. The power rate was assumed to be $0.06 per kWh and tile H2O2 cost was assumed
to be $0.50 per pound on a 50% basis. Acid for pH adjustment is not considered since it
was not demonstrated to improve treatment performance. Maintenance costs are estimated
at 8% of the capital investment per year. Labor for repair and maintenance is estimated at
2% of the capital investment per year. Other operator attention, is not normally required.
TABLE 2. DIRECT COSTS FOR perox-pure™
TREATMENT OF SITE DEMONSTRATION GROUNDWATER
Capital Investment ($)
Power ($71000 gallons)
50% H2O2 ($71000 gallons)
Maintenance Parts ($71000 gallons)
Maintenance Labor ($71000 gallons)
Total Operating Cost ($71000 gallons)
Unspiked
$55,000
0.10
0.34+
0.17
0.04
0.65
Spiked
$125,000
0.90
0.71+
0.38
0.10
2.09
+ Based on non-optimized H2O2 dosage.
Ill
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CONCLUSIONS s
The results of the SITE demonstration with the full-scale perox-pure™ equipment
show that unsaturated VOCs can be rapidly destroyed by more than three orders of
magnitude in a few seconds. With the latest generation oxidation chamber design, saturated
VOCs are also rapidly destroyed. The total treatment cost associated with the perox-pure™
System can be lower that $1 per 1000 gallons and is economically competitive with
conventional treatment processes which produce solid or vapor-phase emissions.
The perox-pure™ technology is ideal for those applications where carbon adsorption
and air stripping are not economical or viable. For example, some priority pollutants such
as methyl-tert-butyl ether, vinyl chloride and methylene chloride are not readily adsorbed
by carbon. Other organics, such as alcohols, phthalates and certain PAHs, are resistant to
air stripping. Further, multi-contaminant matrices present difficulties for consistent
performance because of competitive adsorption effects. The perox-pure™ Process provides
reliable, consistent destruction in each of these cases. In certain instances, it is advisable
to combine the perox-pure™ System with a conventional treatment method to provide the
most economical treatment scheme.
FOR MORE INFORMATION
Additional information on the perox-pure™ photochemical oxidation process can be
obtained by contacting Christopher Giggy of Vulcan Peroxidation Systems, Inc. at (800)
552-8064. This contact can also be used to determine if the perox-pure™ Process is
applicable to a specific, contamination problem or obtain a written estimate of treatment
considerations and economics.
REFERENCE
1 "perox-pure™" Chemical Oxidation Technology", EPA Applications Analysis
Report, EPA/540/ART93/501, July 1993.
112
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TEE CAV-OX* PROCESS
Date W. Cor
j Magnum WatCT- TVj
600 Lairport Street, El Segundo,CA 90245
Phone:(310)640-7000
INTRODUCTION
The CAV-OX* Process is a synergistic combination of hydrodynamic cavitation and ultraviolet radiation
which oxidizes contaminants in water. It is a cost effective method of removing organic contaminants from waste
streams and/or ground water without releasing VOC's. The Process can achieve reduction levels necessary for
meeting discharge specifications in most aqueous contaminant situations. The; total CAV-OX* Process consists of
either the CAV-OX*! Low Energy UV Module and/or the CAV-QX*n High Energy UV Module. "Easy"
contaminants such as gasoline or TCE require only a CAV-OX*! system, while more difficult contaminant streams
such as PGP require a CAV-OX*n system. The CAV-OX* process generally reduces contaminants by 95% to
99.99%.
The CAV-OX* technology is covered by three issued U.S. Patents and one pending Patent Applications.
CAV-OX* is a Registered Trademark.
HYDBODYNAMIG CAVITATION
When a body of liquid is heated under constant pressure, or when its pressure is reduced at constant
temperature by static or dynamic means, a state is ultimately reached at which vapor or gas and vapor-filled micro
bubbles, or cavities, become visible and grow. The bubble growth will be explosive if it is primarily the result of
vaporization into the cavity.
The condition is known as "boiling" if it is caused by temperature rise and 'cavitation* if it is caused by
dynamic pressure reduction at essentially constant temperature. Cavitation involves the entire sequence of
physical events beginning with bubble formation and extending through cavity collapse.
Cavitation is very useful in the breakdown of organic chemicals and living organisms. (Figure 1). Quoting
Scientific American Feb. 1959, in cavitating water: "The heat from cavity implosion decomposes water into
extremely reactive hydrogen atoms and hydroxyl radicals. During the quick cooling phase, hydrogen atoms and
hydroxyl radicals recombine to form hydrogen peroxide and molecular hydrogen. If other compounds are added
to the water, a wide range of secondary reactions can occur. Organic compounds can be oxidized or reduced".
"The heat from cavity imploskms decomposes
water into extremely reactive Iiydrogen atoms
and hilmgl rarHoalg --- Organic
compounds can be oxidized, or reduced."
Scientific-American 1959
FIGURE 1
113
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In recent cavitation experiments, quoted in Science Sept. 1991, "the temperature of collapsing bubbles
have been determined experimentally to be 5075 degrees K +/-156 degrees K" (Figure 2). This high
temperature provides insight into the efficacy of the cavitation process to break down complex organic
compounds." When the micro bubble collapse occurs, in addition to instantaneous temperatures of up to 5000
degrees K, pressures of over 1000 atmospheres are produced.
th«* temperature of the «*olk»jpjang bubbles
has been determined experimentally to be
5075K+/- 156K
Science 1991
FIGURE 2
CAV-OX* APPUCATION
In the CAV-OX* system organic wastes are oxidized into carbon dioxide by a free radical mechanism.
Free radicals are generated and maintained by the combination of cavitation, seeding with hydrogen peroxide,
metal catalysts and UV excitation. If required, reaction initiators are first added to the waste water entering the
cavitation chamber. The oxidation process begins in the cavitation chamber, then in the UV reactor and
continues after the stream leaves. Eecycling back through the entire process can be controlled either after
cavitation, after UV oxidation, or with a combination of the two. During the oxidation, organic carbon is
converted to carbon dioxide and the sulfides to sulfates. No solids are generated. The effluent from the system is
low in organics and is disinfected by the high intensity UV and carbon transition.
RESULTS: CAV-OX* CHA"MKMI^ONLYTest Data
As stated above the CAV-OX* Process is a synergistic combination of three chemical processes in treating
contaminated waste water:
(1) hydrodynamic cavitation (from the CAV-OX* Chamber)
(2) ultra-violet radiation (from the UV reactors)
(3) hydrogen peroxide injection (as necessary)
The best results are always attained in using the above combination in the process. However,
occasionally it is desirable to use the CAV-OX* CHAMBER ONLY applications, that is NO hydrogen peroxide,
NO ultraviolet. Table 1 shows test results with BETX and TCE. Test Analyses were by SHIMADZU GC-14A
Gas Chromatograph using EPA Method 8021.
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EXAMPLE 1: EDWARDS AIR FORCE BASE TESTS.
TABLE I
CAV-OX* CHAMBER ONLYTEST DATA
PERCENT REDUCTION
Benzene
PBQTOCOLA
57%
54%
41%
32%
PBQTOCOLB
37%
37%
40%
PBOTOCOLC
23%
17%
19%
16%
Ethyl
Benzene
11%
39.6%
71%
20%
44%
43%
ND
54%
60%
53%
24%
Toluene
37%
52%
49%
43%
38%
37%
55%
31%
26%
26%
20%
Xylene
+
51%
59%
ND
38%
37% .
ND
38%
42%
35%
23% ....
TCE
65%
60%
45%
41%
38%
37%
33%
24%
22%
19%
18%
NOTE:
NOUV;NOH202.
EXAMPLE 2:
SOUTHERN CALD7ORNIA EDISON COMPANY
CAV-OX* CHAMHKR ONLY tests were done for Southern California. Edison Company. A tank with 3
million gallons of contaminated salt water was to be cleaned to discharge levels using only CAV-OX*. (No HoOo,
NO UV.) The contaminants were oils, surfactants, dyes & ferric oxide. The contaminated salt water did not
meet discharge criteria. The following test data is from the SCE Laboratory. In the opinion of SCE, if CAV-OX*
ONLY was used, no PERMITS were required since the CAV-OX* pump moved the salt water from a tank to a
discharge line that met discharge criteria. Economic cost data for this proposed installation was $0.13 per 1,000
gallons.
Results: 86% reduction in BOD
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BESULTS FROM TEE SHE DEMONSTRATION, EDWARDS A3B FOKCE BASE
The preferred operating conditions for the CAV-OX*! Low Energy configuration was an influent
hydrogen peroxide concentration of 23.4 mg/L and a flow rate of 0.6 gallon per minute (gpm). At these conditions
the effluent TCE and benzene levels were generally below target levels (5 ug/L and 1 ug/L, respectively). The
average removal efficiencies for TCE and BTEX were about 99.9 percent.
The preferred operating conditions for the 5-kW CAV-OX*n High Energy configuraton was an influent
hydrogen peroxide concentration of 48.3 mg/L and an flow rate of 1.4 gpm. At these conditions, the effluent TCE
and benzene levels were generally below target levels (5 ug/L and 1 ug/L, respectively). Average removal
efficiencies for TCE and benzene were about 99.8 percent.
The preferred operating conditions for the 10-kW CAV-OX*n High Energy configuraton was an influent
hydrogen peroxide concentration of 48.3 mg/L and an flow rate of 1.4 gpm. At these conditions, the effluent TCE
and benzene levels were generally below target levels (5 ug/L and 1 ug/L, respectively). Average removal
efficiencies for TCE and benzene were about 99.7 and 99.8 percent, respectively.
RESULTS FBOM SELECTED CASE STUDIES
Superfund Site, Pensacola, Florida
Pentachlorophenol reduced by 96%.
CHEVEON Service Station, Long Beach, California
TPH reduced by 99.94%.
US Army - Presidio, San Francisco, Califonia
TPH, ethylbenzene reduced to Non-Detectable
Steel Mill, South Korea
Cyanide, phenol reduced by 99.9%.
Chicken Farm, Virginia
2,000,000 cfu/mL Salmonella reduced to .01 cfu/mL.
Chemical Plant, Baltimore, Maryland
BOD reduced by 94.1%.
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DEVELOPMENT STATUS
Tables IE and IDE give a list of CAV-OX* installations and CAV-OX* demonstrations sites.
TABLEn
CAV-OX* Systems hare been installed at:
Chevron Environmental Services
Southern California Edison Co.
Advanced Micro Devices Corp.
International Technology Corp.
U.S. Army Presidio
Private Ranch-Well water for
drinking purposes
10 gpm CAV-OX*!
1 gpm CAV-OX*!
10 gpm CAV-OX*!
10 gpm CAV-OX*!
20 gpm CAV-OX*!
5 gpm CAV-OX*!
TABLE HI
CAV-OX* Systems have been demonstrated at:
EPA Superfund Site - Pensacola, Florida
Edwards Air Force Base - SITE Demonstration
EPA Superfund Site Bog Creek Farm Site - New Jersey
San Bernardino Water Department
Orange County Water District
Geological Research Inc.
CMIMSA S.A. de C.V., Saltfflo, Mexico
Resources of the Pacific Ltd., Fiji Islands
MEDIA AND POLLUTANTS TREATED
CAV-OX* is only applicable to aqueous streams with low contaminant levels: for example, BETX below
approximately 100 ppm. Grease, oil and turbidity decrease the efficiency of the UV reactors. However, the
cavitation chamber is unaffected by such factors. Tables IV, V, and VI give specific chemicals treated by the CAV-
OX* Process.
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TABLE IV
Contaminants Treated by the CAV-OX* Process
Atrazine . Cyanides
Chlorinated organics . . Phenol
Halogenated organics . Bacteria
Petroleum hydrocarbons . Viruses
Polychlorinated biphenyls (PCB)
Polynuclear aromatic hydrocarbons
(PAH)
Benzene, toluene, ethylbenzene,
and xylenes (BTEX)
TABLEV
The CAV-OX* process can treat the following
cantamoiaQts in industrial
Amines
Chlorinated solvents
Complex cyanides
Hydra aine compounds
Methyl ethyl ketone (MEK)
Methyl isobutyl ketone (MIBK) .
PCP
Polynitrophenols
2,4,6-Trinitrotoluene
Xylene
Aniline
Chlorobenzene
Creosote
Isopropanol
Methylene chloride
PCB
Pesticides
Cyclonite
Toluene
TABLE VI
The CAV-OX* process can treat the faiQawing
Bis(2-chloroethyl) ether
1,2-Dichloroethane
Dioxins
Freon 113
MEBK
PCBs
Pesticides
Tetrachloroethene
Trichlorothene
Triglycol dichloride ether
Creosote
Dichloroethene
Dioxanes
MEK
Methylene chloride
PCP
PAHs
1,1,1-Trichloroethane
Tetrahydrofuran
Vinyl chloride
118
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TNTITAL AND FINAL POU.T3TANT CONCENTBATION
The cavitation chamber ONLY process reduces contaminant concentrations by about 20 to 50 percent.
The synergistic combination of cavitation and UV radiation can reduce contaminant concentrations from 95 to
99.99 percent.
The CAV-OX* process produces no air emissions and generates no residue, sludge, or spent media that
require further processing, handling, or disposal. If contaminants are reduced to non detectable levels, the
effluent consists of water with some dissolved carbon dioxide gas, halides (for example, chloride), and in some
cases organic acids. No VOCs are released to the atmosphere. Any remaining contaminants remain in the
effluent.
RATED TFmnm m HI rr
Theoretically any size CAV-OX* System can be built. The largest built to date is a 50 gallon per minute
unit. A 20 gpm unit is used at a U.S. Army site and several 10 gpm units are employed cleaning up ground water
from gasoline stations.
ECONOMIC ANALYSIS
Table VII give economic cost data for the CAV-OX* Systems.
TABLE
Typical operating costs tar the CAY-OX* process; are:
. CAV-OX* cavitation chamber only r about $0.50
PER 1,000 gallons of treated water
. CAV-OX* cavitation chamber with low-enerjgy UV
radiation and hydrogen peroxide - about
$2.00 per 1,000 gallons of treated water
to $4.00 per 1,000 gallons.
. CAV-OX* cavitation chamber with high-energy UV
radiation and hydrogen peroxide - about
$4.00 per 1000 gallons of treated \vater
to $10.00 per 1,000 gallons.
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Table Vlil presents cost data for the CAV-OX*! Low Energy System process with UV radiation plus
hydrogen peroxide. The contaminant of concern was benzene, and the treatment goal was to reduce
concentration from 50,000 micrograms per liter (ug/L) to 50 ug/L.
TABLE Vm
ECONOMIC ANALYSIS FOE GROUNDWATER TREATMENT
Process rate:
25gpm
CAV-OX*!
LOW-ENERGY
PROCESS
CAPITAL COST
Equipment
Installation
Total
58,000
3,000
61,000
ANNUAL OPERATING COSTS
Power ($0.08/kWh)
Carbon
Chemicals
Maintenance
Amortization
(20% per yr.)
Labor (air monitoring)
TOTAL
Treatment
Cost/1,000 gal
3,592
0
1,741
5,114
11,600
0
22,047
$1.67
CONCLUSION
The CAV-OX* Process has been proven in various installations and demonstrated in a variety of
contaminant situations. The EPA SITE Demonstration at Edwards Air Force Base has produced an Applications
Analysis Report giving precise technical details of the CAV-OX* Process. Also, a technical video is available on
the CAV-OX* SITE tests available from the EPA.
The CAV-OX* Process is economically cost effective and is less expensive than other Advanced Oxidation
Systems.
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A NEW AIR STRIPPING METHOD TO
ECONOMICALLY REMOVE VOCS FROM GROUNDWATER
Andreas Beck, triplan GmbH, Alemannenstr. 16 D-86/51 Monchsdeggingen Germany
Wayne Schuliger, T1GG Corporation, 31 Moffett St. Pittsburgh, PA, U.S.A 15243 (412) 563-4300
INTRODUCTION
The use of air for stripping volatile organic contaminants (VOCs) from water is well established and
is an accepted treatment process in the environmental field. By choosing the proper stripper
dimensions, number of stripping stages, and air-to-water ratio, a wide range of water flows and VOC
concentrations can be treated, in many instances, to meet non-detectable levels.
Frequently, the regulations limit the amount of VOCs that can be emitted into the air. This in turn
requires the use of offgas treatment such as carbon adsorption or catalytic incineration. Both of these
processes add significant capital and operating costs to the cleanup operation.
The development of triplan's vacuum stripper extends the range where a stripper is a viable
technology. Since the air-to-water ratio, for the same removal, is significantly reduced, the
concentration of the VOCs in the offgas is proportionately higher. Because! triplan manufactures both
atmospheric and vacuum strippers, an unbiased evaluation can be made as to which technology is
appropriate. ;
METHODOLOGY
The design of the stripping tower is based on the theoretical height and number of transfer units
concept. This means that the packing height is the result of the product of the height of a transfer unit
(HTU) and the number of transfer units (NTU's). The height of a transfer unit is directly proportional
to the liquid flow per unit cross sectional area and inversely propoitional to the initial VOC
concentrations, the overall liquid mass transfer coefficient, and specific interfacial area of the packing.
The number of transfer units is a function of the desired concentration change, the air-to-water
ratio, Henry's constant and the system pressure. The latter three factors relate, as shown below, to
quantify the stripping factor: •
R = (H/PsKG/L)
where:
R = stripping factor
Ps = system pressure
H = Henry's constant
G = air rate
L = water rate
The larger the stripping factor the better the VOC removal.
greater than two.
Usually the stripping factor should be
An inspection of the aforementioned equation shows that in a conventional air stripper, operating
at atmospheric pressure and a given temperature, the only variable is the air-to-water ratio. However,
it's also obvious that, if the pressure is reduced, the stripping factor is increased. This leads to two
advantages which the engineer can evaluate. First, the same performance can be achieved by reducing
the air-to-water ratio in direct proportion to the reduction in pressure. Secondly, when compounds
such as naphthalene and ammonia, which have low Henry's constants, must be removed, the stripping
121
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factor, and thus the performance at the same or lower air-to-water ratio, can be increased by reducing
the pressure.
Typically, the vacuum stripper is designed with an air-to-water ratio one-tenth that of an
atmospheric stripper. As a result the same VOC removal is obtained.at a similar consumption of
energy. This reduction in air volume results in a proportionate reduction in the size of the offgas
treatment equipment. In addition, the resultant increase in the concentration of contaminants can
result in a 30-100% increase in the capacity of activated carbon. Likewise, catalytic oxidation
efficiency is improved. Furthermore, with favorable Henry constants, the vacuum technique can
remove contaminants to stringent effluent water specifications without additional treatment such as
liquid phase carbon being required.
Figure 1 shows the flow scheme of a vacuum stripper system which typically includes: stripping
tower(s), fluid pump(s); vacuum pump(s); a dehumidifier; and an offgas treatment system! The pumps
are especially selected for removing treated water from the stripper. The offgas treatment system is
somewhat independent, but normally consists of activated carbon adsorption or catalytic oxidizer
components. Atmospheric strippers have similar components except for the vacuum pump.
AIR
STRIPPER
AIR INLET
TREATED
WATER
DFFGAS
TREATMENT
SYSTEM
EFFLUENT
PUMP
VACUUM
PUMP
IK-
TREATED
AIR
WATER TO BE
TREATED
PREHEATER CONDENSER
Figure 1. Schematic of a typical system
As with other contactors, proper packing and good air and liquid distribution are important so
that the vacuum effect will not be impaired and its theoretical advantages achieved. Another
requirement is that the liquid to be stripped should not contain appreciable amounts of foaming
constituents or oils.
RESULTS
To date there are five operating systems that have operated a total of 20,000 hours. Thus, the
technology is not a laboratory curiosity but is field proven. Most liquids which contain strippable
compounds can be treated via this technology. At the present time it does not appear that there
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are any limitations to the degree of removal that can be obtained, especially with the use of two
towers in series.
Table 1 summarizes the operating conditions for three vacuum air stripper systems utilizing two
stripping towers in series. An inspection of the data in this table reveals the effectiveness of this
technology.
TABLE 1. SUMMARY OF PERFORMANCE OF THREE SYSTEMS
CASE
NO.
1*
2**
3
WATER
GPM
(m3/h)
4.5
(1)
119
(27)
35
(8)
AIR
SCFM
(m3/h)
3
(5)
30
(50)
12
(20)
CONTAMINANTS
Xylene,
Methylene
chloride
BTX, chlorinated
hydrocarbons
Trichloroethylene
INFLUENT
ppm
27 .
47
125
EFFLUENT
ppb
<20
250
7
REMOVAL
%
99.93
99.47
99.99
* In this case the iron level was 11 mg/l. Hardness was >300 mg/l.
** In this case the iron level was 3 mg/l.
A beneficial feature of the vacuum technique, which is not part of the theory, is the ability to
minimize microbiological growth and fouling of the packing due to chemical precipitation. In a
vacuum stripper the growth of the microorganisms is suppressed because of the low pressure and
low air-to-water rates. As a result, downtime for cleaning and replacing packing is significantly
reduced. These effects were observed in Cases 1 and 2. In Case 1 the stripper column did not
require the initial cleaning until 4000 operating hours. This compares to an expected 400-500
hours for conventional strippers. It's obvious that this will result in lowered operating costs and
greater convenience.
As would be expected, the capital cost of a vacuum stripper is higher than capital for traditional
atmospheric stripping. The column(s) must be built for the vacuum duty, and instrumentation is
more elaborate. This extra capital is in the range of 30-40%. However, this is somewhat offset by
the lower capital cost of the off gas treatment section.
The electrical operating costs for the vacuum system are about 10% above those for the
atmospheric systems. The major operating cost savings occur in the offgas treatment system.
Because of the typical 10:1 reduction in air flow the treatment systems are smaller and more
efficient. Operating costs for these systems can be on the order of one half that of traditional
systems. Further savings are experienced in those instances where there would be less frequent
cleaning due to minimization of biological fouling and chemical precipitates.
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CONCLUSIONS
Vacuum stripping is becoming an established treatment method in Germany. In a series of full
scale applications, this technology has demonstrated highly efficient water purification
performance at low air-to-water ratios which resulted in reduced off gas production. It is
compatible with all standard offgas treatment schemes such as adsorption, solvent recovery, and
catalytic incineration.
Advantages are found in the insensitivity of the technique to fouling due to bacterial and
chemical precipitation with lower attendant maintenance; high stripping efficiency; smaller, higher
efficiency offgas treatment equipment; and in many cases, the elimination of the need for liquid
phase carbon following the stripper. Because of these inherent technical and practical advantages,
vacuum stripping is very versatile and can be adapted to numerous field variables and challenges.
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PILOT SCALE INVESTIGATIONS OF THE IN SITU IMMOBILIZATION OF HIGHLY ARSENIC CONTA-
MINATED SOIL
Manfred Stammler
Rainer Rohde
Dieter Koerner
Harry Jehring
envi sann GmbH
Lehrter Str. 16-17
10557 Berlin
Germany
Tel.: 030-3948647
Fax : 030 - 394 3944
INTRODUCTION
The site of about 100 000 m2 (25 acres) is located in an industrialized area within the boundaries
of Berlin. At the beginning of this century it was owned by a chemical company which produced sulfuric
acid by roasting sulfide minerals such as arsenopyrites. The solid residues of the roasting process were
probably deposited on the company site.
Since 1926 the site is owned by an Oil Company. Various buildings and storage tanks were erec-
ted. Later, roads and railroad tracks were added. The site is still commercially used by the Oil Compa-
ny. First reports on groundwater pollution became known in the 1980th, when an approximately 2 km
distant waterwork observed arsenic in some of its production wells. An extensive investigation was
initiated which indicated that the contamination source is on the site in question, and covers an area of
approximately 10 000 m2 (2,5 acres).
The main contamination sources are in the eastern part of the area with arsenic concentrations of
> 1 g/ kg. Peak values of up to 78 g As/kg were measured. The contamination has penetrated to depths
of > 7 m. The waterwork is located about 2 km east of the site, therefore the groundwater flow
direction is toward east.
The goal of this project is to protect the waterwork wells from As-contamination with as little as
possible disturbances of the commercial operations at the site.
CHARACTERIZATION OF THE AS-CONTAMINATION
Roasting sulfides for instance FeAsS results in the formation of SO2 (gas) and oxidic iron and arse-
nic compounds. Of specific interest here are the oxidic arsenic compounds. All of them have an ap-
preciable solubility in water, which is of the order of >10 g/Liter and which explains the contamination
of the waterwork wells. To reduce the solubility substantially, for instance by reforming the sulfides in
situ, using H2S, (NH4) 2S or similar compounds bears the danger of large scale secondary contamina-
tion. Besides, the formed sufides show either an appreciable carbonic acid oir NH4* solubility . Therefo-
re a literature search was initiated.lt showed that from the point of view of stability and insolubility ferric
arsenates are promissing candidates for an immobilization process.
LABORATORY STUDIES
The laboratory experiments were aimed to obtain information on the
- selection of suitable compounds for the As-immobilization in the soil
- conditions for the immobilization of As
- process parameters (concentration, volume of required solutions,
PH, and reaction time) for the fixation.
The geological and chemical site analyses revealed the following facts:
- The As-contamination reached peak values of up to 80 g As/kg Soil
- As-concentrations of >1 g As/kg soil were found in depths of up to 7 m
- The water and carbonate solubility of Arsenic-compounds is considerable.
The arsenic compounds contain predominately As(V). As long as the soil is atidic(PH<6), arsenates
and arsenttes will go into solution. VWth increasing PH-values ferric-hydroxide gels and ferric-arsenates
are precipitated.
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METHODOLOGY
A total of 6 glas-columns were filled with 1,25 kg of contaminated soil containing 800-7700 mg As/kg
soil. Two sets of experiments were conceived to immobilize the arsenic.
Ferric chloride (FeCy was used in set 1 while ferric acetate was injected in set 2. All experiments
were carried out over a time period of 264 h.
An appreciable mobilization of As occurs, when Fe CI3 (Set 1) is injected. This mobilization is ac-
companied by a rapid drop of the PH-value to 1.4, The PH-value recovered only very slowly with time.
The injection of ferric acetate also causes a reduction of the PH-value, however, only to a PH = 5,
with a rapid recovery to neutral.
After a short mobilization phase no further arsenic was detectable in the leachate.
The PH-stability has been ascertained between 3,0 and 7,8. However, it can be assumed that the
stability range of the formed ferric arsenate is wider than that.
RESULTS
Before conceiving and planning a field experiment H: was decided to verify the results on a larger scale.
In addition we wanted to obtain information on
- horizontal flow conditions
- on site preparation of ferric-salt solutions
- methods to externally precipitate the mobilized As.
The experiments were carried out using a containment with the dimensions
length: 2,0 m; width: 1,0 m; height: 1,5 m
The containment was filled with contaminated soil from the site with known As-content and compacted.
A typical sequence of operations shows an oxidation period of approximately 12 days, and an immobil-
zation time of about 30 days.
The As teachability during this time period shows that the mobilization phase starts at about day 28
(during the injection of ferric acetate) and ends at about day 65 with continuously dropping As-values in
the leachate. After about 80 days 0,07 mg As/Liter were found in the leachate with steadily decreasing
values.
REMEDIATION COSTS
As mentioned earlier, no field tests have been performed which would permit a more accurate cost
comparison with other suitable methods. Regardless, we have attempted to calculate the remediation
cost for a defined area and compare them with a possible alternative, the soil washing, a technology
also practised in Europe.
The cost calculations for the in situ immobilization of arsenic in soil are based on the following site
parameter
Site parameter:
Total area : 100 000 m*~ 25 acres
Contaminated area: 10000 m2~ 2,5 acres
Contamination depth (average) : 4,5 m
total contaminated volume
density ~ 2,0:
Average As-contamination:
Total As-content in soil:
Soil permeability:
45 000 m3-90 0001
>100 mg As/kg soil
9t
>10'7 m/s
Depending upon the distribution of the contaminants in horizontal and vertical direction, hydraulically
closed circuits will be established consisting of several remediation islands.
Each island consists of an arrangement of injection and discharge wells.
As a rough estimate we assume about 2500 Injection probes and approximately 100 discharge wells
The probes are in average about 2 m apart from each other.
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INVESTMENTS (in 103 DM )
- 2500 injection probes
-100 discharge welte, 15 m deep
- pipes, connectors, pumps
- Equipment: chemical tanks
storage tanks, precipitators
2.500,- DM
500,- DM
1.500,-DM
1.700.-DM
6.200,-DM
ANNUAL OPERATING COSTS (in 103 DM )
- chemicals, other materials 300,- DM
- personnel costs 350,— DM
- energy, disposal, others 250.- DM
900,- DM
Add up to a total of DM7.100.000,-
Considering the uncertainties involved in this rough estimate one can figure the total remediations costs
for the 45 000 m3 to be of the order of
~ 12 000 000,-DM
or - 7 000 000,-US $
Specifically the costs can be expressed to
DM 270,-/m3 ~ US $ 157/m3
or on a weight basis
DM 135,-/ton ~ US $ 80,-/ton
for the in situ immobilization.
Currency exchange rate: 1 US $ = 1,7 DM.
A comparison of remediation costs per ton for the in situ immobilization of heavy metals and the
soil cleaning methods (from organic contaminants) is finally shown below:
In situ immobilization : 80 US $ / ton
Soil washing (Harbauer) (1) 125-200 US $/ton
Soil Cleaning (MTB Umwelttechnik AG) (2) 250 US $/ton
Because these Figures are encouraging, We are looking for a suitable site to field test the described
method.
CONCLUSIONS
An in situ immobilization of arsenic contaminated soil is possible, using state of the art technologies.
A precondition for the described process is a certain permeability of the soil for water.
Due to the high carbonic acid solubility of arsenic sulfides the conversion to ferric arsenates is
favored. Using on-site preparation methods of ferric acetate, secondary pollution is minimized/The
PHstability-range of ferric arsenttes lies between 6 and 8.
During the injection phase, mobilization of As has been observed.
By properly placing discharge and monitoring wells around the in srtu-treatment zone, further spreading
of the contamination can be avoided.
The As-leachability dropped to below 0,07 mg As/liter. No field test has yet been carried out. This
was mainly due to a change of the anticipated utilization of the site in question.
However, we believe that the described method is suited as a remediation of heavy metal contamina-
ted soil, in particular arsenic, where excavation is uneconomical and where possible commercial opera-
tions must continue during remediation. The cost comparison to soil washing methods is favorable.
127
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REFERENCES AND ACKNOWLEDGEMENTS
(1) W. Groeschel, FIVE YEARS OF OPERATIONAL EXPERIENCE WITH THE HARBAUER SOIL
WASCHING PLANTS, 4. Forum on Innovative Hazardous Waste.Treatment Technologies, San
Francisco CA, Nov. 17-19,1992, (Page 16-17).
(2) A. Bachmann, SOIL REMEDATION AT SCHWEIZERHALLE: A CASE STUDY , 4. Forum on Inno-
vative Hazardous Waste.Treatment Technologies, San Francisco CA,, Nov. 17-19,1992,
(Page 21).
The cooperation of the BGI Corp and the K & K Corp during the course of this work is greatly apprecia
ted.
This work was supported by the Senate of the city of Berlin.
128
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Colloid Polishing Filter Removal of Heavy Metals, Uranium andTransuranic Pollutants
from Groundwater at The DOE Rocky Flats Plant
Tod S. Johnson, Ph.D.
Filter Flow Technology, Inc.
3027 Marina Bay Dr., Suite 110
League City, TX 77573
INTRODUCTION
DOE Rocky Flats Plant and ITPH
The U.S.D.O.E.(DOE) Rocky Flats Plant is located in northern Jefferson County, Colorado
about 16 mile NNW of downtown Denver. The RFP consists of a 400 acre plant site situated
inside a 6,550 acre restricted zone. Agricultural land and mountains are situated just North of
the plant, with residential and commercial industrial development to the East and West. A
lake is located immediately South of the site. Five Solar Ponds were placed into service
between August, 1956 and June, 1960 and used until 1986 as illustrated in figure 1. The solar
ponds were used for storage of nuclear weapons production liquid wastes, contaminated
groundwater, sewer sludge, sanitary treatment plant effluent and treated acidic wastewater.
Examples of pollutants known to have been introduced into the Solar Ponds are listed below.
Low-level radionuclides(tritium, &
long-lived alpha emitters
Nitrates/nitrites
Solvents
Acids (HC1, H2SO4» HNO3)
Aluminum hydroxide
Hexavalent chromium
Ammonium persulfates
Bicarbonate
Cyanide solutions
Ferric chloride
Lithium chloride
Lithium metals
The integrity of the Solar Pond liners was breached by physical and. chemical action by the late
1970's and early 1980's, thereby contaminating the groundwater. The ground water flow
from the five solar ponds is North initially, were an interceptor trench pump house (ITPH)
collects the contaminated groundwater, while an interceptor trench system (ITS) on the hill
side just North of the Solar Ponds.collects surface water. In 1992 three (3) 500,000 gallon,
plastic lined, metal storage tanks (OU4 IM/IRA tamls) were install^ on the hillside at a higher
elevation, West of the ITPH (see figure 1).
Colloid Polishing Filter Method (CPFM)
The Colloid Polishing Filter was developed as an economical, yet high performance sorption
filter for removing trace heavy metal and non-tritium radionuclide pollutants from water. By
using efficient, insoluble, inorganic sorption bed material (i.e. Fitler Flow-1000) , together
129
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with specially designed and engineered equipment to control fluidics and then optimizing the
influent water chemistry and flux rate, it is feasible to efficiently remove a side spectum of
inorganic metallic pollutants from water that exist not only as soluble ions, but colloids, and
complexed and chelated forms. The sorption filter functions predominantly via efficient
surface sorption and charge dependent chemical complexing phenomena and to a lesser extent
(appx. 5%) by physical particle filtration. This report describes the U.S.E.P.A. (EPA) SITE
Demonstration experimental testing and results obtained for the Colloid Sorption Filter
treatment of the DOE Rocky Flats Plant ITPH groundwater removal of representative heavy
metal pollutants and Uranium, Plutonium-239 and Americium-241 radionulcides1-
METHODS OF PROCEDURE
The EPA SITE Demonstration at the DOE Rocky Flats Plant was carried out jointly with the
EPA. Regon VIE office, Denver, CO.and DOE under a Memorandum of Understanding
between the EPA and DOE Headquarters. The purpose of the demonstration was to evaluate
the Colloid Polishing Filter as an alternative methodology for treating and remediatiing Total
Uranium, Uranium-238, Uranium-234, Plutonium-239 and Americium-241 pollutants in the
ITPH groundwater.
ITPH groundwater bench testing was carried out at the Rocky Flats Plant during 1992 and 1993
and the SITE Demonstrattion was conducted in September, 1994, using ITPH groundwater
that had been pumped to the OU4 IM/IRA storage tanks West of the ITPH. The groundwater
had been pumped into the tanks in June, 1993 in preparation for evaporator tests, but due to
delays the water was stored in the tanks during late June, July and August prior to the
demonstration and a heavy algae bloom was evident as fine green, cloudy particles in the 25
to 28°C, stored in the tanks by early September. The Colloid Polishing Filter equipment,
together with mixing tanks, an incline plate clarifier, pre-filter assembly, pumps, pipes and
electrical and electronic control panels was transported from Houston, TX to the Rocky Flats
Plant. Following radiologically survey and inspection of the trailer and equipment, the trailer
was moved to a pre-staging area for final checkout, then moved to the demonstration staging
area at the OU4 IM/IRA tanks as illustrated in figure 1.
Figure 2 shows a CAD drawing of the Colloid Polishing Filter and equipment treatment train
used for the demonstration. The tank stored ITPH groundwater was pumped at 5 gpm from
the middle tank to a mixing tank and second reaction tank (for optional chemical
conditioning), the bulk solids removed in an incline clarifier and overflow water positive
pressure pumped through a pre-filter(10 micron, polypropylene, bag filter) and into the
manifold assembly for distibuting the water in serial or parallel mode to two, vertically
mounted, Colloid Polishing Filters. Effluent water from the polishing filters was collected in a
third tank for final pH adjustment, then the water pumped to a different OU4 IM/IRA storage
tank. A series of tests were conducted at 5 gpm, continuous flow using 4 hr test periods plus a
15 hr run, where samples of the influent groundwater (untreated, Control), intermediate (post
clarifier, but pre-polishing filters) and effluent water (treated, downstream from the polishing
filters). PRC Environmental Management, Inc. (Denver, CO) prepared the demonstration
130
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Rgure 1. Drawing of the DOE Rocky Flats Plant showing the iaction of the Interceptor
Trench Pump House (ITPH) relative to the Solar Ponds (i.e., 207C, 207A, 207B North,
207B Center and 207B South) contamination source. The SITE Demonstration staging
area is shown (upper Jeft) at the OU4 CM/IRA tanks.
pipeline rnou ITPH
HUONSTRATION
STACINO AREA
INTERCEPTOR TRENCH KOf HOUSE
-------
plan'- provided the demonstration test staging, health safety, QC/QA and support and was
responsible for all sampling and laboratory analysis procedures. An EPA Program Fact Sheet2
and Demonstration Bulletin' were prepared by the EPA. The sampling procedures followed
the GA/QC outlined in the SITE Demonstration Plan based on EPA guidelines2-4. An
independent, EPA certified commercial laboratory was responsible for the analytical
chemistry, heavy metals and radiochemistry, which was carried out following standard EPA
procedures. This report describes results obtained for treating the ITPH groundwater at the
DOE Rocky Flats Plant heavy metals, uranium, Plutonium-239 and Americium-241.
RESULTS AND CONCLUSIONS
Table I shows representative analytical data obtained for the influent (Control) versus Colloid
Polishing Filter treated (effluent) ITPH groundwater at the DOE Rocky Flats Plant, based on
the bench and pilot testing. With the exception of mercury (concentrations to low to evaluate)
and Silicon (influent conentration low), which was 98% the Percent Removal Efficiency for 18
seventeen heavy metals was 99.4% to >99.9%. Considereing the complex water chemistry
for the ITPH groundwater, it was concluded that the Colloid Polishing Filter Method
performance for removing metals from the goundwater was competitive with conventional
nucrofiltration, ultrafiltration, ion exchange and reverse osmosis (RO) techniquies. The
advantages of the methodology for treating groundwater metal pollutants, would be expected to
be higher removal efficiencies for colloidal and complexed/chelated forms not readily removed
by ion exchange and RO and lower capital equipment and operational costs. In addition, the
Colloid Polishing Filter Method has application for removing colloidal and soluble ions at
moderate to higher flux rates not achievable with the micromembrane filtration methods.
Figure 3A shows the histogram plots for the bench tests The radiochemical data are plotted as
isotope activity (pico Curies per liter, pCi/1) representing the influent (Control) versus effluent
(treated) ) groundwater samples. For the bench tests (figure 3A) the influent mean (and two
sigma) Total Uranium was 98 12 PCi/l compared to 0.15 0.12 pCi/1 for the Colloid Sorption
Filter treated samples or an estimated >99 % Removal Efficiency. Influent Uranium-234 (56
10 pCi/1) and Uranium-238 (35 6 pCi/1) were observed to be reduced down to <0.03 pCi/1
each based on alpha spectrometry. Control (Influent) Plutonium-239 (7 1 pCi/1) and
Amencium-241 (22 4 pCi/1) were removed by the "polishing" filter down to the alpha
spectroscopy, radiochemical lower limit of detection ranges of <0.01 pCi/L. These results
indicate that the Colloid Sorption Filter efficiently removed the Plutonium-239 and
Amencium-241 transuranic pollutants from the groundwater at a > 99 % Removal Efficiency.
Represenative radiochemical data obtained, for the continuous demonstration at the Rocky
Flats Plant, Golden, CO. are plotted in figure 3B. The ITPH groundwater (containing algae)
was treated at 5 gpm with the Colloid Sorption Filter Method using trailer-mounted equipment
in September of 1993. The concentrations of influent Uranium, Plutonium-239 and
Amencmm-241 were very similar to the bench test data, despite a one year period between the
tests. The influent (Control) groundwater contained 98 12 pCi/1 Total Uranium that was
reduced to 0.15 0.12 pCi/1 after Colloid Sorption Filter treatment (>99 % Removal
Efficiency). Isotopic alpha spectroscopy data obtained for Uranium-234 and Uranium-238
132
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Table I. Extnpies of bench and demonstration data obtained for heavy metals. Data (statistical means) are shown for the Influent (Control)
versus Effluent (Treated) using the Colloid Sorption Filter Method in tests at the DOE Rocky Flats Plant, Golden, CO.
Heavy Metal
Boron
Cadmium
Chromium + •*
Cobalt
Copper
Iron
Lead
Mercury
Molybdenum
Nickel
Selenium "*" *
Selenium + 6
Silicon
Silver
Strontium
Tellurium
Thallium
Vanadium
Zinc
Control (Influent)
mg/l (mean)
0.660
0.033
2.971
0.046
35.290
0.230
4.461
< 0.0002
47.565
1.540
1.715
0.750
0.021
0.055
0.751
0.103
0.032
6.740
58.357
Test (Effluent)
mg/L (mean)
0.006
<0.001
0.006
< 0.002
0.003
< 0.001
0.008
< 0.0002
0.018
0.009
0.004
0.003
< 0.003
< 0.005
0.007
0.004
< 0.001
0.006
0.005
Figure 3. Examples of performance achieved by the Colloid Polishing Filter for the
removal of Uranium, F!utonium-239 and Amnericium-241 pollutants from the ITPH
groundwater. (A) Bench test experiments and (B) pilot demonstration tests.
B
Uranium U-234 U-23» Pv239 Am-241
Radiochemical Pollutant Assayed
U-23« U-238 Pu-239
Radiochemical Pollutant Assayed
133
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indicated that the influent activities were 56 10 and 35 6 pCi/1 respectively and the "polished"
effluent reduced to the 0.02 to <0.01 pCi/1 range (>99 % Removal Efficiency). Similarly,
>99% Removal Efficiency was observed for the transuranics. The influent Plutonium-239 7
1 pCi/1 and Americium-241 22 4 pCi/1 activities were lowered to <0.01 pCi/1 by the Colloid
Politshing Filter Method consistent with high performance "polishing" of these transuranic
pollutants.
Uranium, Plutonium and Americium isotopes are Actinides and characterized by long-lived,
alpha emitting decay products which are major environmental and health hazards, due to high
biological toxicity. For both the bench and pilot tests - Uranium, Plutonium-239 and
Americium-241 was experimentally tested for removal by the Colloid Sorption Filter in the +6
and +4 oxidation-reduction states and no significatnt difference was observed in the %
Removal Efficiency for these radionuclides for removal as +6 or +4. Under these testing
conditions for the ITPH groundwater (pH 7 to 9), the Actinides, would be expected to form
comnplexes with anions in aqueous mileau.that produce polyhydroxyl colloidal species.
Based on the bench and demonstration tests conducted at the DOE Rocky Flats Plant, Goldent,
CO described in this report, it was concluded that the Colloid Polishing Filter Method
performed efficiently (>99% Removal Efficiency) as a "polishing" filter for heavy metal,
Uranium, Plutonium-239 and Americium-241 pollutants in the ITPH groundwater. The
methodology has application as an inorganic metallics "polishing" filter for a wide range of
soluble ionic as well as colloidal, complexed and chelated forms. An operational requirement
of the methodology is for low suspended solids influent water, optimized water chemistry and
carefully designed bed volume and configuration for site specific applications. The equipment
tested performed adequately. The methodolgy evaluated in the EPA and DOE bench and
demonstration tests1'5'9 should provide an alternative treatment and remediation strategy for
inorganic metallaic polluted groundwater at Superfund and weapons sites.
The Colloid Polishing Filter Method can be used as trailer or skid mounted equipment; as a
"polishing" filter for in-line systems; as an efficient treatment system for removing heavy
metals and non-tritium radionulcides from sludge or soil washing wastewater; and for
remediation of secondary wastewater generated from Decontamination and. Decommissioning
projects with mixed-waste, LLRW or Uranium and transuranic pollutant contaminated concrete
and scrap metals. A detailed review and evaluation of the capital equipment costs and
operational costs is in progress.and will be reported.
REFERENCES
1.
2.
Demonstration Plan for the CPFM Technology. SITE Superfund Innovative
Technology Evaluation, Final Report, October, 1993. U.S.E.P.A. Office of
Research and Development, Risk Reduction Engineering Laboratory,
Cincinnati, OH.
Interim Guidelines and Specifications for Preparing Quality Asurance Project
Plans: QAMS-005/80. EPA-600/4-83-004, February, 1983.
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3. Quality Assurance Quality Control Guidance for Temoval Activities: Sampling
QA/QC Plan and Data Validation Procedures: Interim Final. EPA 540/G-90-004,
April, 1990.
4. Preparation Aids for the Development of Category I Quality Assurance
Project Plans. EPA/6008-91/003, February, 1991.
5. Filter Flow Technology, Inc.: Heavy Metals and Radionucli.de Filtration. IN: The
Superfund Innovative Technology Evaluation Program; Technology SSProfiles
Fourth Edition, pp 82-83, EPA/540/5-91/oo8, November, 1991.
6. Program Fact Sheet, September, 1993. Demonstration of title Colloid Polishing
Filter Method, Rocky Flats Plant, Golden, Colorado, U.S.E.P.A., Office of Solid
Waste and Energency Response, Washington D.C.,, August, 1993.
7. Demonstration Bulletin. Colloid Polishing Filter Method, Filter Flow Technology,
Inc. SITE Superfund Innovative Technology Evaluation. EPA/540/MR-
94/XXX, January, 1994.
8. Laul, J.C., O. Erlich, C. Tice, T.C. Greengard, T.S. Johnson and R.O.
Hoffland. Removal of Uranium, Plutonium and Americium From Rocky Flats
Waste Water. Proceedings of The International Topical Meeting, Nuclear
and Hazardous Waste Management, SPECTRUM '92, Boise, Idaho,
August, pp 637-642, 1992.
9. Johnson, T.S., R.O. Hoffland and J.C. Laul. Removal of Trace Heavy Metals,
Uranium, and Transuranic Pollutants From Water Using The Colloid Sorption
Method. International Symposium on Environmental Contamination in Central
and Eastern Europe, BUDAPEST '92; October 12-16, 1992, pp 812-816
10. Environmental Restoration and Waste Management. Five-Year Plan Fiscal Years
1993-1997. U.S.D.O.E., Washington D.C., August, 1991.
11, Cleaning Up The Nation's Waste Sites: Markets and Technology Trends.
EPA/542/R-92/012, PEIL, 1993.
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APPLICATION OF MINERAL BENEFICIATION PROCESSES FOR LEAD REMOVAL
AT A CAMP PENDLETON. CA. SMALL ARMS FIRING RANGE
By Jerdd L Johnson and W. Richard McDonald, Metallurgists, U.S. Bureau of Mines,
Salt Lake City Research Center, 729 Arapeen Dr., Salt Lake City, UT, (801) 584-4157
and
Barbara Nelson, Leslie Karr, Doris Tong, and Jeffrey Heath,
Naval Facilities Engineering Service Center, Code L71, Port Hueneme, CA, (805) 982-1668
INTRODUCTION
The U.S. Bureau of Mines, Salt Lake City Research Center (SLRC), and the Naval Facilities
Engineering Service Center (NFESC) assembled and operated a 1,500 Ib/hr pilot plant designed for the
removal of heavy-metal contamination at active and abandoned small-arms firing ranges. The plant,
designed to be mobile for on-site treatment of contaminated soil, was transported to Marine Corps Base
(MCB) Camp Pendleton, OceanskJe, CA. The pilot plant operated for a 2-week period processing over
15 tons of lead-contaminated soil. This paper describes the field testing of the mobile plant, evaluation
of its performance, and the future of the process.
To identify the extent of environmental problems associated with small arms ranges, an extensive
characterization of several ranges was conducted by the NFESC. The study revealed that the build-up
of bullets in the target and impact berms creates source areas for metals contamination. Lead
concentrations have been found to be as high as 33,000 ppm. Left unattended, contamination may be
dispersed into the environment along various pathwaysjncluding surface-water runoff and airborne dust
migration. Thus, these berms and their surrounding areas, if not property managed and remediated, are
potential sources of groundwater and non point-source pollution. Furthermore, the presence of high
levels of toxic metals in the soil may be a threat to humans, wildlife, and plants.
Traditional berm maintenance consisted of excavation and landfilling of the soil. Not only is
disposal of the soil as a hazardous waste costly and environmentally unfriendly, it does not solve the
problem of possible future contamination. This process solves the problem by removing the heavy
metals from the soil.
Vegetation samples obtained from small arms ranges indicate that lead levels for plants growing in
contaminated soil may be 100 times that of background samples. Copper levels are slightly elevated.
The majority of lead and copper in the berm exist as large fragments, but significant amounts of fine
particles, smeared lead, and weathered products were also found during mineralogical examination.
Heavy-metal contamination in surface soil samples increases parallel to the direction of fire for the small
arms range. Similar profiles extend to a depth of more than three feet in the impact berms. Elevated
lead levels have been observed in the area behind the berm due to stray rounds and runoff.
The remediation study consisted of applying techniques used in mineral beneficiation of ores
produced by mining to firing range soils. Metallurgical testing generally begins with a liberation/gravity
amenability study. The procedure consists of screening the sample into a series of particle size intervals
and processing each interval by some gravity technique such as tabling.
The case of the firing range soils is similar to gold placer ores where the heavy metals are not
locked in the matrix of the particles and do not need to be liberated by grinding. However, the
liberation/gravity amenability study was very useful in evaluating the distribution of the metals through
the particle size range. The liberation/gravity amenability tests identified four major characteristics of the
soil which determined the process selection, (1) a size was identified where bullets and large fragments
136
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could be efficiently collected simply by screening, (2) gravity beneficiation was very effective in
recovering the free heavy metal, (3) residual lead not recovered by gravity concentration was smeared or
attached to the soil grains, and (4) the lead contamination was elevated in the ultra-fine grain fraction
(particle diameters less than 10X10"6 m) of the soil.
Gravity separation techniques were therefore selected as the first step to remove the free heavy
metals from the soil. Leaching was the method selected to remove the lead smeared or attached to the
soil grains and the fine lead particles, described in characteristics 3 and 4. The residual lead in the
gravity tails was present as well-exposed smears and should be amenable to leaching. Selection of a
lixh/ant involved a literature search which identified nitric acid and acetic acid as reagents that efficiently
dissolve lead. Acetic acid was selected over nitric acid because it Is more selective and less harsh to
the environment. Laboratory tests showed that an acid concentration of 2.5 volume percent was of
sufficient strength to dissolve the lead.
The volume of soil (gravity plant tailings) with smeared lead produced from a full size plant could be
considerable. A method used in the mineral industry to easily leach large volumes is the heap leach. A
heap leach comprises piling the soil on some kind of impervious liner, pumping the leach solutions onto
the heap, and collecting the solution after it has percolated down through the heap. This method allows
for construction of the heap as fast as the tailings are produced. The soil can then be leached upon
completion of the heap without throughput constraints.
The fines cannot be placed in the heap because they will inhibit percolation of the leach liquor.
Therefore, the fines are leached in agitated tanks as they are produced. Since the duration of this leach
could run for days, the rate the fines could be processed would be limited to a rate slow enough to fill
reasonably sized and quantity of mixing tanks. The controlling step in the digiestion of lead by acetic
acid is the oxidation of elemental lead. This required the addition of an oxidizer to the leach liquor;
bleach (NaOCI) was found to be an effective oxidant.
METHODOLOGY
The pilot-scale study at MCB Camp Pendleton demonstrated methods to remove three forms of
metal contamination: large fragments, fines and smears. The plant was divided into three main circuits,
the gravity plant, fines leach, and heap leach circuits. Each circuit is briefly described below.
The gravity plant removed the large bullet fragments.
1. First the soil was screened into three size fractions;
a. The coarsest size fraction contained particles larger than 0.25 inch.
b. The middle size fraction (minus 0.25 plus 0.05 inch) was processed by a mineral jig.
c. The undersize (minus 0.05 inch) from the second screen was fed to a classifier.
2. The mineral jig used a pulsed upward flow of water to collect the metal fragments which settle
into the concentrate hutch. The lower density soil particles spilled over the top and were used to
construct the heap pile.
3. The classifier removed the fine particles or fines (<0.003 in.) from the minus 0.05 inch fraction.
With the fines removed, the classifier sand fraction was then fed to a spiral concentrator.
137
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4. The densest fraction of the classifier sand was collected by the spiral concentrator (the
concentrate) and fed to a shaking table where the lead concentration was upgraded and the rest of the
classifier sand joined the jig tailings to construct the heap pile.
5. The fines from the classifier were first fed to the Mozley Multi-Gravity Separator (MGS) which
removed lead particles larger than 5 x 10"6 m. The tailings from the MGS were fed to the fines leach
circuit.
The fines leach circuit was run concurrently with the gravity plant and leached the MGS tailings to
extract the fine lead. The leach solution was then washed from the residue in a three-stage wash. The
lead-bearing water was recycled after the lead level was reduced using beads containing a metal-sorbing
biomass. This lead-bearing water was batch fed into tanks containing the beads. This was continued
until the beads reached the break through point and could not remove any more metals. The metals
were then stripped from the beads using a nitric acid solution. The beads were then reconditioned with
a sodium hydroxide solution before being reused to clean more water. Leach solutions were kept
separate from the gravity circuit water to reduce the volume of water requiring extensive cleaning prior
to disposal.
The heap leach pile was constructed using the tailings produced while the gravity plant was in
operation. Following the week-long test of the gravity plant, the heap was leached using a dilute acetic
acid and bleach solution.
RESULTS
The overall on-site plant performance showed good results and full potential to perform as
designed. The gravity circuit removed 96% of the total lead and produced four lead-bearing byproducts.
The coarsest soil fraction contained 78% of the total lead, the mineral jig collected 13%, the spiral/table
collected 4%, and the MGS collected 1%. The gravity circuit lowered the lead contamination from 1.2%
to 0.05%. The heap residue, after the 4-day run, had 2 out of 20 soil samples pass the TCLP limit (5
Mg/l Pb) with values about 3 Mg/l Pb. About 10% of the soil had a TCLP lead value of 6.5 Mg/l Pb.
The overall average was 10 Mg/l Pb, showing that the leach was terminated prematurely and has the
potential to clean the soil. The fines leach circuit tested three leach conditions with one of five samples
approaching the TCLP value of 15 Mg/l Pb. With the fines leach residue at 15 Mg/l Pb, they could be
recombined with heap leach residue (3 Mg/l Pb) producing overall clean soil (5 Mg/l Pb). There were
some difficulties experienced at MCB Camp Pendleton and they are discussed below for each circuit.
The gravity circuit efficiency could be improved by preventing the following conditions. The soil was
processed wet to reduce airborne lead-bearing dust. The feed pile was kept damp to reduce air
emission, but resulted in the soil sticking to the feed conveyor. A second problem was low screen
efficiency with 10 to 20 weight percent of the undersize from each screen short circuiting to the oversize
fraction. This resulted in lower efficiencies for the concentrating equipment, the mineral jig, and
spiral/table. This drop in efficiency can be easily seen in table 1 which gives the analysis of screen
fractions of the jig feed and tailings. The short circuit fraction contained 9.8% of the lead in the feed, but
70% of the lead in the tails. The jig very effectively removed the lead from the - 0.25 + 0.05 inch size
fraction, dropping the grade from 0.32% to 0.009% lead. Even with the short circuited undersize, the jig
efficiency was 95%. .......
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TABLE 1. COMPARISON OF JIG CONCENTRATION EFFICIENCY ON DESIRED FEED SIZE
AND SHORT CIRCUITED UNDERSIZE
Size
™
interval, inch
0.25 + 0.05
-0.05
Wpinhf -
percent
85.8
14.2
Jig feed
Lead, %
Grade
0.32
0.21
Dist
90.2
9.8
weignt -
percent
83.0
17.0
Jig tailings
Lead, %
Grade
0.009
0,103
Dist
29.9
70.1
The fines leach circuit experienced difficulty in keeping the fines suspended. This was largely due
to improper size and shape of the rented tanks, tanks of the desired specifications were not available.
The heap leach circuit could be improved by two changes; first, improved screening will raise the
concentration efficiency by processing each particle size interval in the proper apparatus. Second, a
longer heap time will allow the acetic acid to pass completely through the heap pile coming into contact
with more of the lead.
Initially, the water treatment plant effectively removed the lead from the fines wash water, allowing it
to be recycled with very low recirculating lead loads. During the first two load-strip-recondition cycles,
the beads removed over 95% of the lead in the liquor. However, after the third cycle, the beads lost
their loading capacity, see table 2, The system does not appear to be over loaded with lead as can be
seen by the similar cycle feed concentrations; the problem appears to be in the stripping. The nitric acid
solution was recycled for the first five cycles without any regeneration. After cycle number 5, the lead
from the stripping acid was precipitated with sodium sulfate and more nitric acid was added (but not to
the strength of the original strip). This regeneration step appeared to restore only part of the loading
capacity. Attempts to clean the water prior to final disposal were marginally successful due to this
lowered loading capacity of the beads. Further studies are being conducted to solve this problem.
TABLE 2. LOADING EFFICIENCY OF THE IMMOBILIZED BIO-MASS BEADS! IN REMOVING LEAD
FROM LEAD BEARING FINE WASH WATER
Cycle
feed,
Cycle Mg/l Pb
Percent of lead removed, 1 period = 4(30 liters
Period 1 Period 2 Periods Period 4 Periods Periods
3 131
4 150
5 146
7 222
87
87
44
74
81
30
8
61
70
26
0
49
74
9
0
44
75
NR
0
38
66
NR
0
31
NR Not run.
Recycling heavy metal byproducts for their metal content was another goal of this research. There
were five lead-bearing byproducts resulting from cleaning the soil in the on-site plant, the pounds of
product per ton of soil processed is provided in the {}:
139
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1. The plus 0.25 inch fraction was upgraded from about 5% metal to 82% metal by using a water
elutrlator, {82}.
2. Mineral jig concentrate (can be upgraded to 82% metal by eiutriation), {2.8}.
3. Non-magnetic fraction of the shaking table concentrate (50% lead), {1.6}.
4. MGS concentrate. From processing the minus 0.003 inch fraction of the soil and includes metal
fragments down to 3 x 10"6 m (1.3% lead), {13}.
5. A sulfate precipitate is produced from the water treatment which is mainly calcium, 20% with
2.5% lead, {not determined}.
Two secondary lead smelters were sent samples of these products, plus one sample made of
weighted portions of samples 1 through 4. They felt samples 1, 2, 3, and the weighted combination,
could technically be recycled but there were significant problems.
The copper content is very high and unless the smelter has a copper bleed from their circuit, there
would be a recirculating load problem if significant quantities were recycled. However, they felt there are
applications where these byproducts could be used. The other contaminates (soil) would reduce the
metal value and Increase the amounts of waste to be disposed. Both of these problems reduce the
value of these byproducts. The price that would be paid for these materials is very low because of the
abundance of lower-contaminated scrap. One smelter concluded that limited quantities could be
accepted but they would have treatment charge beyond the value of their metal contents.
Samples 4 and 5 are too low in metal content and neither smelter felt they could, by themselves, be
recycled.
CONCLUSIONS
This on-site test was very beneficial toward commercialization of this technology. First, it was
established that a plant of this nature could be transported to a contaminated site, reconstructed, and
operated. Second, the importance of efficient screening and classifying was learned. Third, the
immobilized bio-mass beads appear to be a viable method of treating lead-bearing liquors produced
from the leach circuits if the stripping stage is improved. Fourth, the heap leach residue approached the
TCLP limit for lead. This, coupled with the bench scale work and in-house pilot plant work, seems to
show the technology will work. Finally, though the fines leach residue failed the TCLP, the lead
contamination was lowered. With more efficient leach conditions, the TCLP value might be lowered to
allow a single cleaned soil product when combined with the heap residue.
The SLRC and NFESC are in the planning stages to perform a second on-site demonstration plant.
This second plant will be used to evaluate engineering changes made after the MCB Camp Pendleton
project, capable of removing lead contaminates from all Navy small arms range impact berms, and to
finalize the engineering data needed to construct a full size mobile plant.
FOR MORE INFORMATION
For more information contact either Jerold Johnson, USBM, 729 Arapeen Dr. Salt Lake City, UT,
84108, (801) 584-4157; or Barbara Nelson, NFESC Code L71, Port Hueneme, CA, 93043, (805) 982-1668.
140
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ACOUSTIC BARRIER PA.RTIQI'! ATE SEPARATOR
Robert R. Goforth
General Atomics/ Nuclear Remediation Technologies Division
3550 General Atomics Court
San Diego, Ca 9212
(619) 455-2499
^ acoustic barrier paniculate separator is a new technology for separation of particulates in a aas
flow. The purpose of this study is to design, construct, and test a pilot scale device. The technology
previously demonstrated at the lab scale, is applicable to removal of particulates from the off-gas stream of
incinerators and thermal treatment processes. The pilot scale system is a 300 dm prototype module
suitable for parallel arrangement to treat larger gas flows.
The test gas is generated by heating an air stream, then injecting a measured dust feed into it to
produce a synthetic flue gas. The test gas flows through a muffler into an acoustic agglomerator section
then vertically against an acoustic wave of a specific waveform propagating opposite the gas flow The '
acoustic wave exerts a nonlinear force on the particulates such that they are stagnated and dritt to the wall
of the separator chamber. There the particulates form cake that falls into a solids collection hopper that
also serves as an acoustic absorber. The clean test gas flows around the acousilic hom and out through
another muffler.
The sound is generated using a gas siren. The waveform is tailored by the pattern of apertures in
the siren rotor and stator. The spent siren air is diverted by an isolator to minimize dilution of the test gas
The siren air is generated by a blower and flows through mufflers both before and after the siren.
The pilot scale test will integrate two separate acoustic effects to provide for removal of the entire
spectrum of particulate sizes. Acoustic agglomeration will be used to convert fines to larger aggreqates
and the acoustic barrier effect will be used to remove those aggregates.
Subscale testing is scheduled to begin in May 1993. This will be followed by up to full scale
operation in unheated gas, then prototype testing in heated gas.
For More Information: Robert R. Goforth
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AIR-DRIVEN. JN-SITU REMEDIATION TECHNOLOGIES
Robert Piniewski
Rolf Laukant
Terra Vac
One Oak Hill Center
Westmont, IL 60559
(708) 850-9358
Terra Vac has designed, installed and operated over 300 in-situ remediation systems based on
air-driven techniques. Air-driven techniques rely on the mass transfer of contaminants from the dissolved,
adsorbed, vapor and free phase to the vapor phase. These techniques are typically orders of magnitude
faster when compared to pump and treat. The air-driven techniques will generally include the process of
vacuum extraction for the recovery of the contaminant. Several enhancements have been developed to
increase the effectiveness of vacuum extraction (VE) in different hydrogeologic settings, address different
contaminant types, and allow VE to be combined synergistically with other techniques to address not only
the unsaturated soils, but contamination in the saturated zone also.
One major development has been the Dual Vacuum Extraction technology. This technique combines
VE with groundwater recovery, thus remediating both the source and contaminated groundwater. In some
situations, Groundwater Sparging (the injection of air into the aquifer) can be combined with VE to also
address the source and contaminated groundwater, especially when disposal of groundwater is a
problem. In low permeability settings, Terra Vac has successfully used VE combined with Pneumatic Soil
Fracturing (injection of high pressure air into the clays to create subsurface flow paths) to achieve site
closure. Other, less aggressive techniques, BioVac and Biosparging, rely on enhancing the natural rates
of blodegradation of petroleum contaminants by increasing the subsurface oxygen levels with VE.
Each of these techniques has been developed to further improve the effectiveness of the basis
vacuum extraction technology. These enhancement techniques now provide a toolbox of technologies, all
based on vacuum extraction, which can remediate soils and groundwater, address low permeability soils,
or use natural biodegradation to remediate soils and groundwater.
For More Information Contact: Robert: Piniewski, Terra Vac, Midwest Division (800) 825-0013 or Rolf
Laukant, Terra Vac, One Oak Hill Center, Westmont, IL (708) 850-9358
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Applications of Chemical Oxidation and Electrochemical
Iron Generation for Removing Arsenic and Heavy Metals from Water
Michael D. Brewster
Environmental Engineer
(Formerly with Andco Environmental Processes, Inc.)
Argonne National Laboratory
9700 South Cass Avenue
Argonne, IL 60439
708-252-9911
and
I
Gary Peck
Vice President Marketing
Andco Environmental Processes, Inc.
595 Commerce Drive
Buffalo, NY 14228-2380
716-691-2100
As a result of many power generation operations, .groundwater and/or surface water has been
contaminated with arsenic and heavy metals. Simultaneous extraction is complicated due to the
various chemical properties that metals exhibit A comprehensive understanding of solubilities,
oxidation states, and adsorptive mechanisms is needed to accomplish treatment objectives This
paper uses data from treatability and pilot studies to discuss the electrochemical iron addition
process developed by Andco Environmental Processes, Inc. Sacrificial steel electrodes were used
to put ferrous ions into solution. Adjustment to an optimum pH resulted in excellent adsorption
and coprecipitation with a ferrous hydroxide floe. When extremely low residual arsenic
concentrations were needed, an oxidizing environment improved treatment Hydrogen peroxide was
used to convert Fe to Fe^ and arsenite to arsenate. By rapidly and efficiently shifting the
existing equilibrium state, having all of the aqueous arsenic as arsenate, and adjusting pH to create
conditions for 100% anion adsorption, arsenic concentrations below 5 Atg/1 were achieved. The
formation of ferric solids (hydroxide, arsenate) and improved adsorption on the hydrous ferric oxide
floe accounted for increased removal efficiencies. When the necessary treatment conditions were
created and maintained, removal by three major mechanisms resulted in an iron sludge that was
able to pass the regulatory levels listed in conjunction with the Toxicity Characteristic Leaching
Procedure (TCLP). Presented data confirms that arsenic, mercury, cadmium, chromium, lead,
selenium, and copper can be removed simultaneously using this treatment process.
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"APPLICATION OF FULL-SCALE SOIL/SEDIMENT WASHING FOR THE
U.S. CORPS OF ENGINEERS & TORONTO HARBOUR COMMISSIONERS"
Richard P. Traver, P.E., Vice-President & General Manager
Scott C. O'Brien, Director - Process Technology
Bergmann USA
1550 Airport Road
Gallatin, TN 37066
(615) 452-5500
During 1991 and 1992, Bergmann USA provided a 5-10 TPH Soil/Sediment Washing System
to the U.S. Army Corps of Engineers for the full-scale demonstration of volumetric reduction and waste
minimization of PCS contaminated dredge spoil from the Saginaw River in Michigan. The
demonstration project was conducted under the ARCS (Assessment and Remediation of Contaminated
Sediments) Program.
This plant was placed into operation in October 1991 a mile and a half off shore aboard a
120'x33' Army Corps of Engineers dredge support barge. Results indicated a reduction of 88% of the
initial PCB concentration with only .2 mg/kg of PCBs remaining in the "clean" coarse +45 micron (325
mesh) fraction. The -45 micron fines were enriched to a maximum level of 14 mg/kg PCBs, and the
humic fraction (leaves, twigs, roots, grasses, etc.) contained up to 24 mg/kg of PCBs. These materials
were scheduled for a biodegradation during the Summer of 1992. Working with the EPA Hazardous
Waste Engineering Research Laboratory in Cincinnati, this Bergmann USA system was evaluated by
the Superfund Innovative Technology Evaluation (SITE) Program in May/June 1992.
Bergmann USA was contracted with the Toronto Harbor Commission in the operation of a 5-10
TPH Soils Washing system for the demonstration of volumetric remedial operations coupled with an
innovative metal extraction and biodegradation technologies for the treatment of the -63 micron fines
fractions. With the receipt of permits from the Ontario Ministry on the Environment, the demonstration
commenced the first week of January 1992 (-10°F) concluding the initial Phase I operations in
September 1992. Rve varying contaminated soil feeds were processed by the Bergmann plant. In
addition, the Wastewater Treatment Centre of Environment Canada contracted to have the Bergmann
plant process 500 tons of contaminated Toronto harbor sediment, and the Canadian Ministry of
Defense had the Bergmann plant process 200 tons of lead contaminated material shipped in from
Montreal from the Longue Pointe Garrison Site. Based upon the results of this demonstration project it
is anticipated that a full-scale plant would then be designed for installation for a three year, 85 TPH
(300,000 tons per year) remedial project of the Toronto harbor front area. This project was conducted
for the Toronto Harbour Commissioners and evaluated under the USEPA's SITE Program.
For more information, please contact:
Richard P. Traver, P.E.,
Vice President & General Manager
Bergmann USA
1550 Airport Road
Gallatin, TN 37066-3739
(615) 230-2217 FAX: (615) 230-2217
144
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APPLICATION OF SONOTECH'S CELLO BURNERS IN SIJPERFIINn
SITES CLEANUP APPLICATIONS
Zin Plavnik and Ben T. Zinn
Sonotech Inc.
575 Travis Street
Atlanta, Georgia 30318
404-525-8530
Sonotech has developed a novel, frequency tunable, Cello® burner that burns the fuel in
an oscillatory combustion process. Typically, the Cello® burner is used to supply process energy
and generate sound that is used to improve the incineration process performance. In a Superfund
application, a Cello® burner of needed capacity is retrofitted to the incineration system and
operated at a frequency that excites large amplitude sound waves within the incinerator. The gas
oscillations that accompany the excitation of the sound increase the rates of mixing, heat and
mass transfer within the incinerator, resulting in a drastically improved incineration process. The
increase in the rates of transport processes improves the efficiency of the incineration process,
resulting in lower emissions of soot, CO and unburned hydrocarbons, which are often
responsible for puff formation. Furthermore, the improved mixing reduces the amount of air
needed (by other burners) to completely burn the waste, which reduces operating and capital
investment costs associated with the use of large air and gas handling systems. Also, the
reduction in process air flow requirements, reduces stack losses, lowering the process fuel
consumption. Also, the improved mixing eliminates hot spots within the incinerator, resulting in
lower NOX emissions. Finally, since the performance of the incineration system is controlled by
the excited sound waves (and not by the gas velocity), it does not deteriorate when the
incinerator is operated at part load, as is often the case when conventional burners are used.
The Cello® burner can improve the performance of existing and new incineration
systems. When retrofitted to an existing incinerator, the Cello® burner improves the system's
performance and it may increase its capacity. On the other hand, whe;a it is retrofitted to a new
incineration system, it reduces the size of the incineration system required (when conventional
burners are used) to attain complete incineration, which reduces capital investment costs.
145
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APPLICATIONS OF TRANSFERRED AND NON-TRANSFERRED PLASMA TORCHES
IN HAZARDOUS WASTE TREATMENT .
Robert E. Haun
Retech, Inc. ,
P.O. Box 997
Ukiah, CA 95482
(707) 462-6522
Plasma technology for treatment of hazardous waste uses heat from a plasma torch to treat
hazardous waste containing metals and/or organics. Retech's experience using transferred and non-
transferred plasma torches will be presented. Relevant aspects of a treatment system design will also be
presented. The merits of transferred and non-transferred plasma torches to melt metal-bearing solids and
soils as well as thermally destroy organics will be compared and contrasted.
Retech has been developing plasma torches since 1970 when a license from Linde Division of
Union Carbide was obtained. Over the years, Retech has producecLmore than 20 megawatts of plasma
melting equipment for the vacuum metallurgical industry. To date, approximately 90% of the plasma
equipment has been of the transferred arc type. Retech's attempt to develop equipment for treating
hazardous waste is based on our vacuum metallurgical/controlled atmosphere background. So far our
experience with contained treatment of hazardous waste has led to an awareness that a reliable, non-
transferred plasma arc torch can offer definite advantages to the treatment system.
For more information please contact: Robert E. Haun, Retech, Inc., P.O. Box 997, Ukiah, CA
95482, Tel. (707) 462-6522, Fax (707) 462-4103. ,
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BIOLOGICAL REMOVAL OF PERCHLOROETHYLENE FROM SATURATED SOILS
Alex Vira and Daniel Groher
ABB Environmental Services, Inc.
107 Audubon Road
Wakefield, MA 01880
(617) 245-6606
ABB Environmental Services Inc. has conducted EPA sponsored research into the feasibility of
using enhanced bioremediation for the restoration of Perchloroethylene (PCE) contaminated aquifers.
The study was funded under the Emerging Technologies component of the SITE program.
PCE contaminated water was pumped through bench-scale saturated soil columns and the
proposed in situ bioremediation process was simulated. Simultaneous microbiological studies were also
carried out to help define the operating requirements. Two approaches to PCE degradation were
evaluated; anaerobic dechlorination of PCE, yielding ethylene as the end product, and sequential
anaerobic/aerobic degradation of PCE in which PCE is partially dechlorinated anaerobically and t
further degraded by aerobic methane oxidizing bacteria, yielding carbon dioxide as the
end product.
then
Results suggest that complete PCE dechlorination can be accomplished in situ at many sites by
the engineered enhancement of indigenous anaerobic bacteria. Vinyl chloride is expected to be a
significant intermediate product in this process. Therefore, under many circumstances sequential
anaerobic/aerobic treatment may be desirable.
Data demonstrating both anaerobic and anaerobic/aerobic degradation of PCE in bench-scale
will be presented, and the respective processes will be discussed. Data will also be presented which
show that this process may be applied to dense nonaqueous phase liquid (DNAPL). Proposed field
approaches will be presented and discussed.
For More Information: Alex Vira, ABB Environmental Services, Inc., 107 Audubon Road
Wakefield, MA, 01880, (617)245-6606
147
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BIOREMEDIATION OF CYCLODIENE PESTICIDE-CONTAMINATED SOIL
Rod Venterea
Fton Hicks
Groundwater Technology, Inc.
4057 Port Chicago Highway
Concord, California 94520
(510) 671-2387
Cyclodiene insecticides, such as chlordane and heptachlor, have been applied for years in the
preventative treatment of wood frame structures against termites. Cyclodiene pesticides have been
determined to be one of the top 50 most frequently found contaminants at Superfund sites (52 FR
12866,1987). The U.S. Environmental Protection Agency (EPA) has classified chlordane and heptachlor
as priority pollutants and has mandated the restoration of impacted sites. Therefore, there is a great
need for effective and cost-efficient remediation technologies.
Preliminary laboratory studies conducted by our laboratory and others have shown that
bioremodiation is a potentially viable method for treating soils contaminated with chlordane and
heptachlor. However, its effectiveness as a treatment technology has not been demonstrated under field
conditions. Additionally, some studies have indicated that these compounds can be persistent under
natural soil conditions, and resistant to biodegradation by indigenous soil microbial populations.
Several species of lignin-degrading fungus have been shown to degrade recalcitrant organic
contaminants, including chlorinated aromatic hydrocarbons, under select conditions. The efficacy
appears to be due to the generation of enzymes which are used to metabolize naturally-occurring
complex polymers such as lignin. The objective of the present study is to examine the ability of certain
fungal strains to metabolize chlordane and heptachlor in a soil matrix. This is being done in laboratory
microcosm studies examining degradation kinetics and the various factors influencing microbial activity.
Following these tests, a pilot-scale soil reactor study will be conducted with the goal of demonstrating
the effectiveness of fungal bioremediation under conditions simulating a field operation.
For more information, please contact Rod Venterea or Ron Hicks, Groundwater Technology,
Inc., 4057 Port Chicago Highway, Concord, California 94520, (510) 671-2387
148
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BIOViNTINQ HAH CONTAMINATION AT. JJE BE1LLE IAS AND CHEMICAL CORPORATION SITE
THE BBSI le^B
Paul T. McCauley
United States Environmental Protection Agency
Risk Reduction Research Laboratory
26 W. Martin Luther King Dr.
Cincinnati, Ohio 45268-0001
Bruce C. Alleman
Battella Memorial Institute
505 King Avenue
Columbus, Ohio 43201-2693
Bioventing is a proven technology for in situ remediation of various types of hydrocarbon
contaminants. The technology has been successfully used to remediate sites contaminated with
gasoline, aviation fuels (JP-4 and JP-5) and diesel fuel. This demonstration evaluates the potential of
bioventing to remediate soils contaminated with polycyclic aromatic hydrocarbons (PAHs).
The Reilly Tar and Chemical Corporation Site is an abandoned wood-processing facility
contaminated with creosote. The site has appropriate PAH concentrations, geologic characteristics,
and responsible parties willing to establish a cooperative effort.
^ The pilot field study features active venting and monitoring of a "treatment area" and monitoring of a
no treatment control area." These two areas (50 feet x 50 feet) were chosen at the site after a soil
gas survey. Composite soil samples (120 soil borings per area) used for PAH analysis, were prepared
by homogenizing the soil obtained from the 4-8 foot depth of each boring. The resultant bore holes
were filled immediately with bentonite. A single vent bioventing system was installed at the center of
the "treatment area." The vent (injection) well was screened from 7-15 feet below the surface and
packed with sand. T he vent well was then sealed with bentonite from the 7 foot depth to the surface
Twelve soil gas probes were installed along diagonals drawn from the comer of the square "treatment
area," and four were installed in the comers of the "no treatment control area." The soil gas probes
were constructed so that the soil gas withdrawal points and thermocouples were located at 4 6 and 8
feet below the ground surface. Initial O2 and CO2 measurements were obtained as percetages of total
soil gas using the gas probes in both areas. The blower was turned on for 24 hours, then turned off
An initial respiration test was conducted by withdrawing gas samples and measuring O, and CO, levels
at measured intervals over a period of 48 hours. The blower was again turned on, and the air flow to
the area was set at 10 cfm (3.5 inches of H2O). Shut down-respiration tests are being conducted
quarterly. The first two quarterly respiration tests lasted five days. Subsequent quarterly tests were
conducted for two weeks.
Shut down-respiration tests have shown respiration rates ranging from below detection to 0.484
percent O2 per hour. The highest respiration rates were found in the western half of the "treatment
area" where PAH contamination was also shown to be the heaviest. Current measured respiration
rates are consistent with a 14% reduction in PAH contamination per year.
For More Information: Paul T. McCauley, United States Environmental Protection Agency Risk
Reduction Research Laboratory, 26 W. Martin Luther King Dr., Cincinnati, Ohio 45268-0001
(513) 569-7444
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CAPABILITIES OF A TRAILER-MOUNTED DEBRIS WASHING SYSTEM
DEVELOPED UNDER THE SITE PROGRAM
Michael L Taylor and Majid A. Dosani
IT Corporation
11499 Chester Road
Cincinnati, Ohio 45246
513/782-4700
and
Donald A. Banning and Naomi P. Barkiey
Risk Reduction Engineering Laboratory
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
513/569-7854
IT Corporation has, under the EPA SITE Program, developed a full-scale, transportable, semi-
automated debris-washing system (DWS) that can be used on site for the decontamination of debris.
The debris-washing technology was recently utilized at the Summit Scrap Site in Akron, Ohio, by IT
Corporation. During the 4-month period of this site remediation, 3000 tons of PCB-contaminated metallic
debris were cleaned and the level of PCBs was reduced to <7.7 /*g/100 cm2. The decontaminated
debris was subsequently sold to a scrap dealer.
In this poster presentation we describe IT's full-scale, trailer-mounted debris-washing system and
present costs for on-site treatment of metallic debris.
For more Information:
Dr. Michael L Taylor
IT Corporation
11499 Chester Road
Cincinnati, Ohio 45246
513/782-4700
or
Naomi P. Barkiey
Risk Reduction Engineering Laboratory
U.S. Environmental Protection Agency
26 Martin Luther King Drive
Cincinnati, Ohio 45268
513/569-7854
150
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COMBINED ANAFRORTT IN-SITU/AEPQBIC EX-SITII BIOREMEDIATIOM
CHLORINATED ETHENES USING AN IMMOBILIZED TPI .
F.S. Lupton, W.G. Sheridan and L.J. DeFilippi
AlliedSignal Environmental Systems & Services
50 E. Algonquin Rd., Des Plaines, Illinois, 60017
AlliedSignal Environmental Systems and Services has
developed a fixed film bioreactor system that utilizes a high
surface area polymer support that is coated with an active layer
of powdered activated carbon. The biomass support matrix is a
porous polyurethane foam with a surface area greater than 200
square feet per cubic foot. This support matrix is coated with e
powdered activated carbon using a .proprietary procedure that
maintains the carbon in an activated state. The carbon coated
roam support is mixed with a polypropylene Hi Flow pall rings to
provide good mass transfer and fluid dynamic characteristics.
This system is being evaluated for the. co-metabolic
oxidation of chlorinated ethenes using phenol as the co-
substrate. Groundwater contaminated with a mixture of
trichloroethylene, cis-dichloroethylene and vinyl chloride is
pumped to the bioreactor system. Phenol and air are introduced
to the bioreactor for co-metabolism of the chlorinated ethenes
The reactor utilizes both a submerged fixed film and a vapor
phase bi of liter to ensure that the chlorinated ethenes are
biodegraded and not removed by air stripping. Biodegradation of
TCE is greater than 99% in the bioreactor system.
The ex-si tu bioreactor system can be utilized with an in-
srtu anaerobic reductive dechlori nation step. Organic nutrients
aje introduced! nto the soil to promote reductive dechlorination
of TCE to cis-dichloroethylene and vinyl chloride These
compounds are more readily desorbed from the soil matrix and can
be recovered in the groundwater for biodegradation in the above
?r°UroAbi?x?actor' Th1s technology will be demonstrated under
the EPA SITE program at the St. Joseph superfund site, St.
Joseph, Michigan in the summer of 1994.
For More Information:
F.S. Lupton
AlliedSignal, Inc.
50. E. Algonquin Rd.
Des Plaines, IL, 60017
708-391-3224
151
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Contaminated Soil Treatment Through Davy International IPDOCS Process
Authors:
J.R. Donnelly
Davy International-Environmental Division
2440 Camino Ramon, CA 94583
Tel: (510) 866-6363
Fax: (510) 866-6554
Co-Author: Graham Wightman
Davy International-Environmental Division
Ashmore House, Stockton-on-Tees
Cleveland, TS18 3RE England
Tel: 011-44-642-602-221
Fax: 011-44-642-341-001
ABSTRACT
Davy International has been developing a unique resin-in pulp and carbon-in pulp (RIP/CIP) for the
treatment of contaminated soils through the EPA site emerging technology demonstration program.
Davy has named this process the in-pulp decontamination of contaminated soils process (IPDOCS).
The process is based on utilizing either resin or activated carbon in a pulp mode to recover metals or to
remove heavy metal or organic content contaminants from contaminated soils, sludges, dredgings or
sediments. These processes are based on unit operations utilized in the mining and mineral
processing industries. The IPDOCS process is similar to soil washing or solvent extraction. Feed
material is sized prior to entering an agitated tank where a leach reagent is added to extract
the contaminants of concern. The leached solids are then passed through cyclones to separate coarse
and fine materials. The coarse materials is washed and sent to disposal. The fine material in a wash
solution pass to a RIP/CIP contactor where the contaminants are adsorb€»d on ion exchange resins
and/or activated carbon. The resin of carbon pulp is separated from the fine fraction and is sent to a
second contactor for elution and further concentration of the contaminants. The regenerated resin or
carbon is then reused and the concentrated contaminants are further treated or recovered. The
clean/fine fraction is dewatered and disposed or recycled.
Davy has been employing bench-scale proprietary RIP/CIP technology to develop criteria for a 2-ton
per day demonstration plant capable of treating a wide range of contaminated soils, sediments and
sludges. Davy has developed preliminary cost estimates for a full system for a number of different
heavy metal contaminants of concern. This program is continuing with further defining of process
strings for larger scale application.
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CONTROLLED VAPOR CIRCULATION IN SUBSURFACE MATERIALS TO ENHANCE THE
BIOREMEDIATION OF ORGANIC CONTAMINANTS
Timothy J. Mayotte and Steven B. Thompson
Brown & Root Environmental, 4641 Willoughby Road, Holt, Michigan 48842, (517) 694-6200
The Subsurface Volatilization and Ventilation System* (SVVS*) is a bioenhancement process that
promotes the removal and destruction of many xenobiotic organic compounds in subsurface
materials. This technology is applied to promote the growth and activity of certain aerobic
heterotrophs native to aquifer materials that are capable of metabolizing or cometabolizing these
compounds. SVVS* delivers and circulates the terminal electron acceptors required for the
microorganisms to complete oxidation/reduction reactions that result in the transformation or
mineralization of the organic contaminants. Typically, this is accomplished through injection of
oxygen-saturated air to the subsurface. Consequently, compounds possessing high vapor pressures
and of low molecular weight may also be "stripped" from affected media by the circulating air.
Stripped constituents captured within the vapor extraction component of the system are treated ex-
situ with biofilters before discharge.
SVVS* currently is being studied under the Superfund Innovative Technology Evaluation
program to evaluate its effectiveness for remediating petroleum and chlorinated aliphatic
hydrocarbons in soil (alluvial sands), groundwater, and buried paint sludge. Prior to design and
construction of the demonstration system, micrpbial enumerations and geochemical and
contaminant profiles were developed for the site through extensive soil sampling and analyses.
This information was used to estimate the volume of contaminated media and evaluate the
potential for bioenhancement in the affected materials. In-situ respiration tests were also
conducted. The results suggested that the soils originally possessed a viable population (10s
cells/gram of dry soil) of microorganisms that were actively degrading the contaminants of concern.
After initiation of the demonstration in March 1993, soil and offgas monitoring data were collected
to evaluate the stimulation of the indigenous microf lora by SVVS* and corresponding contaminant
destruction by bioremediation, and to calculate mass removals promoted by the vapor extraction
component of the system. These data suggest that, in seven months, at least 70% of the original
contaminant mass has been remediated by SVVS*. Further, it appears that the indigenous microbial
population has increased to approximately 10s cells/gram of dry soil, and that over 40% of the total
contaminant mass remediated was destroyed in-situ through biologically-mediated chemical
transformation reactions.
For more information contact Timothy J. Mayotte at the address and phone number listed
above.
154
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THE CROW™ PROCESS FOR IN SITU TREATMENT OF HAZARDOUS WASTE SITES
Lyle A. Johnson Jr. and L. John Fahy
Western Research Institute
P.O. Box 3395
Laramie, Wyoming 82071
(307) 721-2281
The CROW™ process is an in situ remediation process for dense organic liquids such as coal
tars, chlorinated hydrocarbons, and heavy petroleum products that have contaminated groundwater at
numerous domestic and international industrial sites. Laboratory tests of the process using materials
from MGP and wood treatment sites indicated that 60 to 70% of the MGP contaminant and 84 to 94%
of the wood treatment contaminant can be recovered at the optimum water flushing temperature.
Additionally, removals of 90% or greater can be achieved for MGP materials if surfactants, at 1% by
volume, are incorporated into the flush water.
Plans for the full-scale remediation of a wood treatment and a MGP site are presently being
implemented. The MGP site is a Superfund Site located in Stroudsburg, Pennsylvania. This
remediation will involve the use of six injection and two recovery wells. The project is scheduled to
begin operation in June 1994. The wood treatment project is located at the Bell Lumber and Pole
facilities in New Brighton, Minnesota. The full-scale remediation is scheduled to being in the summer of
1994 and will be carried out as a staged remediation using three five spot patterns. Prior to
implementing the full-scale project at Bell Lumber, a pilot test was operated to demonstrate the
containment and organic removal features of the CROW process. The piliot test was a success in both
areas.
If further remediation of a site is required, the use of bioremediation following the CROW
process has been evaluated by Remediation Technologies Inc. (ReTeC). ReTeC has been successful
in evaluating in situ bioremediation processes for treatment of CROW conditioned soils. In addition,
biological treatment of CROW process product water was demonstrated. Biological treatment of the
CROW product water is being incorporated into the Stroudsburg, Pennsylvania project.
For More Information: Lyle A. Johnson Jr, Western Research Institute, P.O. Box 3395,
Laramie, WY 82071-3395, (307) 721-2281.
155
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DEMONSTRATION OF AMBERSORB® 563 ADSORBENT TECHNOLOGY
Russell E. Turner and Joseph F. Martino
Roy F. Weston, Inc.
1 Weston Way
West Chester, PA 19380
610-430-3097
Deborah A. Plantz and Eric G. Isacoff
Rohm and Haas Company
727 Norristown Road
Spring House, PA 19477
215-641-7478
The overall objective of this SITE project is to demonstrate the technical feasibility and cost
effectiveness of Ambersorb 563 carbonaceous adsorbent for the treatment of groundwater contaminated with
volatile organic compounds (VOCs). Ambersorb carbonaceous adsorbents are a family of patented,
synthetic, tailorable adsorbents that were developed by the Rohm and Haas Company, Philadelphia, PA hi
the 1970's for the remediation of contaminated water,
One of these adsorbents, Ambersorb 563, has been found to be extremely effective in the removal of
low levels of VOCs and synthetic organic compounds (SOCs) from contaminated water. Previous
applications using Ambersorb adsorbents have shown that they exhibit several key performance benefits over
granular activated carbon (GAC). Ambersorb 563 adsorbent can be regenerated on-site using steam.
Ambersorb 563 adsorbent has approximately five to ten times the capacity of GAC for VOC contaminants,
such as chlorinated hydrocarbons, when the contaminants are present at low concentrations. Ambersorb 563
adsorbent can operate at higher flow rates than GAC, while maintaining effluent water quality below
drinking water standards.
The Ambersorb technology demonstration will consist of a continuous pilot (1 gallon per minute)
field study at Site 32/36 at Pease AFB, Newington, NH. The field testing program, scheduled to begin hi
April 1944, will consist of four service cycles and three steam regenerations over a period of approximately
eight weeks. The pilot unit includes two adsorbent columns that will allow direct comparison of the
performance of Ambersorb 563 adsorbent to GAC. The quality of raw contaminated groundwater (influent)
and treated effluent will be monitored for VOCs during each service cycle hi order to establish breakthrough
curves. In addition to monitoring for VOCs, selected influent and effluent column samples will be measured
for pH, conductivity, and alkalinity. After breakthrough, steam regeneration of the columns will be
performed. Steam will be used to strip the VOCs from the Ambersorb adsorbent and the condensate will be
collected. The organic phase which separates from the condensate will be disposed and the aqueous phase
will be treated through the Ambersorb adsorbent column to demonstrate "superloading".
Analytical results and process data will be evaluated to determine the feasibility of using Ambersorb
adsorption technology in groundwater remediation as an alternative to GAC. Cost and performance
characteristics of this remediation system will be developed in order to compare full-scale uses for this
emerging technology to other proven treatment systems.
For More Information:
Mr. Russell E. Turner
Roy F. Weston, Inc.
1 Weston Way
West Chester, PA 19380
610-430-3097
158
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DEVELOPMENT OF FUNGAL COMPOSTING SYSTEMS FOR DEGRADATION OF
POLYAROMATIC HYDROCARBONS ASSOCIATED WITH MANUFACTURED GAS PLANT
SITES ,
Douglas M. Munnecke and Mark Fletcher
Environmental BioTechnologies Inc.
4040 Campbell Ave, Menlo Park, CA 94025
4154626700.
During the first half of this century, the production of manufactured gats from coal resulted in
waste products containing a wide range of polyaromatic hydrocarbons. There are over 2000
contaminated manufactured gas plant (MGP) sites throughout the United States and the cost of
remediation of these sites is estimated to range between $4-6 billion using conventional
technology.
In two research and development programs sponsored by the Electric Power Research
Institute (EPRI), over 15,000 fungal cultures were initially screened for their potential to degrade
polyaromatic hydrocarbons (PAH). Over 500 cultures were screened in a laboratory robotics
program that generated over 500,000 data points on how these fungal cultures responded to
various environmental nutrient conditions and organic pollutants. From this screen, top cultures
were identified for specific chemicals and environmental conditions. Control cultures such as P.
chrysosporium and C. versicolor were used to calibrate how other fungal species responded in
these tests in comparison to these well studied cultures. For most hazardous chemicals
examined, many fungal cultures were identified that had enhanced potential in comparison to the
two control fungal cultures described above.
In a related program at Michigan Biotechnology Institute which was also sponsored by EPRI,
fungal composting systems were developed which would support these fungal cultures. Results'
in soil pan experiments with selected cultures showed that fungi could degrade the 2345
and 6 ring PAH chemicals in soils.
Environmental Biotechnologies Inc. in a grant received from the EPA SITE Emerging
Technology Program, will continue the development of fungal systems for PAH degradation and
apply this process to soils contaminated with MGP wastes. This EPA sponsored program will
examine 20 fungal cultures ranked high for PAH degradation as identified in the earlier screening
program The focus of this program, which started in late 1993, is to optimize degradation
conditions for the cultures which degrade PAH, scale up the process to small scale, and
determine the effectiveness of this process for applications in the utility industry.
159
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DEVELOPMENT OF THE UDRI PHOTOTHERMAL DETOXIFICATION UNIT
John L. Graham
Barry Dellinger
Environmental Science & Engineering
University of Dayton Research Institute
300 College Park
Dayton, Ohio 45469-0132
(513)229-2846
Chien T.Chen
US-EPA/RREL
Mail Stop 104
2890 Woodridge Avenue
Edison, New Jersey 08837-3679
(908) 906-6985
There has long been interest in utilizing photochemical methods for the detoxification of
hazardous organic materials. Unfortunately, classical, low temperature (i.e., ambient or near ambient
temperature) photochemical processes are either too slow or fail to sufficiently mineralize the targeted
wastes to be practical for wide spread use. Researchers at the University of Dayton Research Institute
(UDRI) have recently developed a unique photothermal process that overcomes many of the problems
previously encountered with photochemical detoxification techniques. It has been shown elevated
temperatures (i.e., >200°C) significantly increase the rate of destructive photothermal reactions and that
these reactions result in the complete mineralization of the organic components of the waste feed.
Furthermore, it has been demonstrated that elevated temperatures that the spectral region of absorption
broadens and shifts towards the visible portion of the electromagnetic spectrum thereby increasing the
efficiency of the absorption of ultraviolet (UV) radiation with increasing temperature. These features (i.e.,
fast, efficient, and complete destruction.of organic vapors) makes this process a promising technique for
the on-srte destruction of toxic organic effluents from many soil remediation technologies such as soil
vapor extraction, steam extraction, and thermal desorption. In this poster the authors will present the
theoretical foundation for the photothermal detoxification process along with a summary of the most
recent test results from the Laboratory Scale-Photothermal Detoxification Unit (LS-PDU). The authors will
also show how this data is being used to design a pilot-scale Photothermal Detoxification Unit (PDU).
For More Information: John L. Graham, Environmental Sciences & Engineering, University of Dayton
Research Institute, 300 College Park, Dayton, Ohio 45469-0132, (513) 229-2846.
160
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DU PONT/OBERLIN MICROFILTRATION TECHNOLOGY (SITE)
Dr. Ernest Mayer
E. I. du Pont de Nemours, Inc.
Du Pont Engineering, Louviers 1359
P.O. Box6090
Newark, DE 19714
(302)366-3652
The novel Du Pont/Oberlin Microfiltration Technology has recently been
demonstrated in EPA's Superfund Innovative Technology Evaluation (SITE)
program. Its key features are fine microfiltration at low cost using Du Pont's new
Tyvek®* T-980 flashspun olefin filter media coupled with Oberlin's reliable
automatic pressure filter (APF) and Enviroguard's PROFIX" filter aid for metals
stabilization.
This new microfiltration technology is best suited for contaminated heavy
metal wastewaters and groundwaters. The SITE demonstration (1990) actually
removed Zn, Cu, Cd, Se and Pb from the Palmerton, PA Zinc smelting Superfund
site. Basically, 99.95% removal of Zinc and Total Suspended Solids (TSS); and
firm, dry (41% solids) cakes that passed both the "Paint Filter Test" and TCLP were
demonstrated. Thus, this new technology provides low cost metals
removal/stabilization all in one simple operation.
This poster will describe this new technology in detail, and will present some
typical application results. It will also detail where it has been applied since the
SITE demonstration. .
For more information, please contact Mr. Mike Hughes, Oberlin Filter Co
404 Pilot Court, Waukesha, WI, 53188, (414) 547-4900.
Du Pont's trademark for its flashspun HOPE nonwoven filtration media.
* Enviroguard's trademark for its patented filter aid/stabilization agent.
161
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THE ECO LOGIC PROCESS
A GAS PHASE CHEMICAL REDUCTION PROCESS
FOR PCB DESTRUCTION
Douglas J, Hallett-, Ph.D.
Kelvin. R. Campbell. P.Eng.
ELI EGO Logic International Inc.
143 Dennis Street
Rockwood, Ontario. Canada
(519) 856-9591
The ECO LOGIC Process is a mobile and highly efficient destruction alternative to
incineration. The process is based on a gas phase chemical reduction of hydrogen with organic
and chlorinated organic compounds'. At 85CrC or higher, hydrogen combines with organic compounds
to form smaller, lighter hydrocarbons, primarily methane. For chlorinated organic compounds,
such as PCBs, the reduction products include methane and hydrogen chloride. This reaction is
enhanced by the presence of water, acting as a reducing agent and a hydrogen source. Destruction
removal efficiencies (DREs) of 99,9999* can be achieved.
A distinct advantage of the ECO LOGIC Process over incineration is that there is no
possibility of dioxin or furan formation. In an actively reducing atmosphere with an abundance
of free hydrogen and no free oxygen, the possibility of their formation is eliminated.
The use of hydrogen also creates a product gas of low molecular weight without the formation
of heavier hydrocarbons common to pyrolysis processes. This product gas is continuously
monitored by a very sophisticated on-line mass spectrometer measures organic compounds in the
parts per billion range. Effective monitoring of destruction efficiency is accomplished by
selectively analyzing for trace concentrations of known breakdown products of the hazardous
waste.
This high efficiency has been demonstrated with PCBs, PAHs, chlorobenzenes, and
organochlorine pesticides. The ECO LOGIC Process was demonstrated as part of the US EPA
Superfund Innovative Technology Evaluation (SITE) Program at Middlegrounds Landfill. Bay City,
Michigan. This site is contaminated by a dense oil containing approximately 4Q% PCBs. This oil,
contaminated groundwater and contaminated soil were processed in separate streams. The
evaluation was performed by the US EPA. A destruction removal efficiency for PCBs of 99.9999£
was obtained for each of the test conditions.
The ECO LOGIC Process can be applied for the destruction of contaminated soils and
sediments, and is also suitable for high-strength organic hazardous wastes such as obsolete
pesticides, warfare agents, and industrial by-products.
For More Information:
Jim Nash •
Manager. Sales and Business Development
ELI Eco Logic International Inc.
143 Dennis Street
Rockwood. Ontario, Canada
(519) 856-9591 (tel). (519) 856-9235 (fax)
162
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ELECTRON BEAM TREATMENT OF UMP.nfMTRni I.ED HAZARDOUS WASTE LEACHATF
Michael G. Nickelsen, William J. Cooper, Thomas D. Waite,
Charles N. Kurucz, and David C. Kajdi
High Voltage Environmental Applications, Inc.
9562 Doral Boulevard
Miami, Florida 33178
TEL (305) 593-5330
FAX (305) 593-0071
The need for effective treatment technologies in destroying multi-source hazardous waste leachate is
expanding as increasingly stringent regulations are being enacted to remedy past as well as prevent
future environmental contamination. Multi-source hazardous waste leachates are of particular concern
because these complex components are commonly found in groundwater and surface waters and have
the ability to persist in the environment for long periods of time. The contaminants discussed in this paper
typically originate from industrial process wastewater, spills, contaminated landfill leachate and
groundwater, or disposal operations associated with various governmental and/or civilian installations
The specific contaminants include halogenated solvents, aromatic hydrocarbons, polychlorinated
biphenyls (PCBs), explosives, etc.
High energy electron beam (E-beam) treatment has proven to be an effective process for destroying
hazardous organic compounds in aqueous solution. E-beam treatment is based on aqueous radiation
chemistry where relatively high concentrations of hydroxyl radical (OH-), aqueous electron (e' ) and
hydrogen atom (H-) are generated when high energy electrons penetrate water. Because the'resultinq
solution contains both oxidizing (OH-) and reducing (e'aq, H-) radicals, the process is effective in treating a
myriad of individual organic compounds as well as complex mixtures commonly found in industrial
wastewaters, landfill leachate, and contaminated surface and groundwater. High Voltage Environmental
personnel have studied many of the regulated hazardous compounds at the Electron Beam Research
Facility (EBRF) located in Miami, Florida. The EBRF houses a 1.5 MeV, 50 mA electron accelerator and
water pumping systems capable of delivering 160 gallons per minute. The variable current allows for
absorbed radiation doses between 0 and 800 kilorads. Removal efficiencies have been determined for
various halogenated methanes, ethanes, ethenes, and propanes, phenols, aromatic hydrocarbons and
polynuclear aromatic hydrocarbons (PAHs). Bench scale 60Co-v irradiation studies have also shown the
process to be effective at removing various explosives, chemical warfare agents, PCBs, and dense non-
aqueous phase (DNAPL) and light non-aqueous phase (LNAPL) liquids.
This paper will present a brief overview of the technology, selected results from simulated
groundwater experiments, and results from bench scale experiments on waters containing NAPL
contamination. The economics of full scale treatment systems will also be discussed.
For More Information Contact:
William J. Cooper, Vice President R&D, or
Michael G. Nickelsen, Environmental Chemist R&D
High Voltage Environmental Applications, Inc.
9562 Dorai Boulevard
Miami, Florida 33178
TEL (305) 593-5330
FAX (305) 593-0071
163
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EVALUATION OF SLURRY-PHASE BIOREACTORS FOR
TREATING PAH-CONTAMINATED SOIL
Majid A. Dosani, Jennifer S. Platt, E. Radha Krishnan and Michael L Taylor
IT Corporation
11499 Chester Road
Cincinnati, OH 45246
513/782-4700
and
John A. Glaser and Paul McCauley
Risk Reduction Engineering Laboratory
U.S. Environmental Protection Agency
26 Martin Luther King Drive
Cincinnati, OH 45268
513/569-7657
In slurry-phase biotreatment of contaminated soil, the excavated solids are typically treated in a
continuously stirred reactor to which nutrients, microorganisms, and surfactants may be added to en-
hance the biodegradation of organic contaminants. Various versions of the bioslurry process have been
Implemented in the field; however, the effectiveness of key process parameters has not been sys-
tematically investigated.
A bench-scale bioreactor study was performed at the U.S. EPA Test and Evaluation (T&E) Facil-
ity in Cincinnati, Ohio, on a soil contaminated with pdynuclear aromatic hydrocarbons (PAHs) obtained
from a Superfund site in Minnesota. In this study, ten 6-liter glass bioreactors were employed and levels
of soil- and liquid-bound PAH concentrations, nutrient levels, pH, dissolved oxygen, temperature, and
microblal activity were monitored in an effort to identify and optimize key operating parameters. The
operating parameters included solids concentration, agitation rate for the slurry, and pH. This poster
presents the design of bench-scale equipment and results obtained during the bench-scale study of the
slurry-phase bioreactors.
For more information:
Majid A. Dosani
IT Corporation
11499 Chester Road
Cincinnati, Ohio 45246
513/782-4700
or
Dr. John A. Glaser
Risk Reduction Engineering Laboratory
U.S. Environmental Protection Agency
26 Martin Luther King Drive
Cincinnati, Ohio 45268
513/569-7657
164
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HRUBOUT® THERMAL OXIDATION PROCESS
Michael G. Hrubetz, President
Barbara Hrubetz, Vice-President
Hrubetz Environmental Services, Inc.
5949 Sherry Lane, Suite 525
Dallas, Texas 75225
214/363-7833
«, The KRUBOUT® process (U.S. Patents 5,011,329; 5,251,750;; 5,261,765) is a mobile
thermal treatment process that removes volatile and semivolatile organic compounds
from contaminated soils. In the process, heated air is injected into the soil below the zone
of contamination, evaporating the soil moisture and removing th« volatile organic
compounds (VOC's) and semi-volatile organic compounds (SVOC'sO. Once the moisture is
evaporated, the soil porosity and permeability is increased, allowing for increases in
pressure and temperature. Low-volatility hydrocarbons can then be removed by slow
oxidation at temperatures up to 800 degrees Fahrenheit.
The process is available in three embodiments: in-situ, ex-situ and a containerized
version. In the in-situ method, injection wells are drffled in pre-determined distribution
patterns to a depth below the contaminated zone. The wells are equipped with steel
casing, perforated at the base, and cemented in the hole. Heated compressed air is
introduced at temperatures up to 1200 degrees Fahrenheit. As the vapors reach the
surface, which is covered with an impermeable cover, a vacuum directs the vent gases to
an oxidizer, where they are destroyed at 1500 degrees Fahrenheit,
The ex-situ process involves a horizontal! piping grid overlain with a mound of soil
and remediates approximately 1,100 cubic yards per batch. The mound is covered with an
impermeable membrane and is treated hi the same manner with heated compressed air.
The containerized method remediates approximately 25 cubic yards per batch and
is processed similarly, except that the soil is enclosed in an insulated container.
For More Information:
Michael G. Hrubetz, President
Hrubetz Environmental Services, Imc.
5949 Sherry Lane, Suite 525
Dallas, Texas 75225
Phone: 214/363-7833 Fax: 214/691-3545
165
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IGT'S NOVEL TECHNOLOGIES FOR MGP SITE REMEDIATION
Robert L. Kelley, Bill Liu, J. Robert Paterek
and Vipul J. Srivastava
Institute of Gas Technology
3424 South State St.
Chicago, II 60616
312-949-3809
IGT has developed and demonstrated two processes to efficiently remediate
soils and sludges contaminated with hazardous compounds such as polynuclear
aromatic hydrocarbons (PAHs), volatile hydrocarbons (e.g. BTEX), and polychlorinated
blphenyls (PCBs). These processes combine biological treatment and
physical/chemical treatment as follows: 1) the integrated Chemical/Biological
Treatment (CBT) or MGP-REM Process and 2) the Fluid-Extraction/Biological
Degradation (FEED) process.
The MGP-REM process is version of the integrated chemical/biological process
specifically designed for manufactured gas plant (MGP) sites wastes. Bench-scale
studies as well as the field-scale tests show that the MGP-REM process is effective in
significantly enhancing the rate as well as the extent of degradation of these
contaminants. The field tests results show that the chemically enhanced
bioremediation using the CBT process results In up to 90% improvement over
conventional bioremediation for total PAHs (2-6 ring compounds) degradation and over
100% Improvement over conventional bioremediation for carcinogenic PAHs (4-6 ring
compounds) degradation.
The Fluid Extraction Biodegradation (FEBD) process has the potential to be an
environmentally benign means of extracting organic contaminants from soil, delivering
the contaminants to bioreactors, and biodegrading the contaminants to CO2, water, and
biomass at optimum conditions. PAHs with 2 to 6 rings were successfully extracted
from contaminated soils using supercritical carbon dioxide and supercritical
CO2/methanoI mixtures. The IGT mixed culture successfully degraded the PAHs in the
FEBD extract In batch and continuous reactor systems. Extensive biodegradation up to
92 and 96% were obtained with 0.5 and 1% extract respectively. A minimum hydraulic
retention time of 1.78 days was determined for the efficient removal of PAHs in the
system. The volatile PAHs contributed an insignificant fraction to the total loss of
PAHs.
For More Information:
Robert Kelley, Manager- Biotechnology
institute of Gas Technology
3424 South State Street
Chicago, IL 60616
(312) 949-3809
166
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INNOVATIVE BTOSLURRY TREATMENT OF POLYNUCLEAR AROMATIC HYDROCARBONS
Kandi Brown
John Sanseverino
IT Corporation
Biotechnology Applications Center
312 Directors Drive
Knoxville, Tennessee 37923
(615) 690-3211
IT Corporation (IT) will conduct a pilot-scale investigation using three, 60-liter (L) EIMCO Biolift™ Slurry
Reactors (EIMCO Process Equipment Company, Salt Lake City, Utah) to biodegiade polynuclear aromatic
hydrocarbons (PAH) in soil. The objective of the investigation is to increase the rate and extent of PAH
biodegradation, thereby, making bioslurry treatment a more desirable remediation alternative.
IT will operate the Biolift™ reactors in series in semi-continuous, plug-flow mode. The first reactor will
receive fresh feed daily with supplements of salicylate and succinate. These compounds have been shown to
increase biological activity against naphthalene, phenanthrene and anthracene by inducing the naphthalene
operon. Therefore, the first reactor in series will be utilized to remove easily degradable carbon and increase
biological activity against more recalcitrant PAH (i.e., three-ring compounds and higher).
Effluent from the first reactor will gravity flow to the second reactor in series where Fenton's Reagent will
be added to accelerate oxidation of contaminants. The third reactor in series will be used as a polishing reactor
for the removal of any partially-oxidized contaminants remaining following addition of Fenton's reagent. Slurry
will be removed from this reactor and clarified using gravity settling techniques. The clarified water will be
recycled to slurry additional soils.
This technology is applicable to PAH-contaminated soils and sludges that can be readily excavated for
bioslurry reactor treatment. Soils from coal gasification sites, wood treating facilities, petrochemical facilities,
and coke plants are typically contaminated with PAH and may be remediated using this technology.
IT's bioslurry reactor system was accepted into the SITE Emerging Technology Program in 1993. The
project was initiate in mid-January 1994.
For More Information:
Kandi Brown, IT Project Manager, IT Corporation, 312 Directors Drive,
Knoxville, Tennessee 37923, (615) 690-3211.
167
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INTEGRATION OF PHOTOCATALYTIC OXIDATION WITH AIR STRIPPING
•Gregory B. Raupp, * "Richard Miller and **Robert D. Fox
'Department of Chemical, Bio and Materials Engineering
Arizona State University, Tempe, Arizona 85287-6006
(602) 965-2828
**IT Corporation
312 Directors Dr., Knoxville. Tennessee 37923
(615)690-3211
In a collaborative demonstration program sponsored by the U.S. Environmental Protection
Agency SITE program, ASU and IT Corporation are evaluating the integration of gas-solid ultraviolet
(UV) photocatalytic oxidation (PCO) downstream of an air stripper unit as a technology for cost-
effectively treating water pumped from a chlorinated volatile organic-contaminated aquifer. This
work should also provide valuable information which could be applied to the evaluation of PCO for
other environmental problems, including treatment of the off gases from soil vapor extraction, and
contaminated air from manufacturing processes.
In photocatalytic oxidation, chlorinated VOCs are destroyed at ambient conditions over a UV-
illuminated titanium dioxide thin film catalyst using the water vapor and oxygen in the air as
oxidants. High conversion to carbon dioxide, water and HCI can be achieved for relatively short
residence times. Based on experimental work performed at the bench scale in laboratories at ASU,
engineers at IT Corporation have designed a demonstration scale PCO unit to be tested at a
Superfund site in the Phoenix metropolitan area. The groundwater at this site is contaminated with
triehloroethylene (TCE) as well as other chlorinated solvents, metals, and petroleum hydrocarbons.
The 150-300 cfm PCO demonstration unit is based on a "flow-through" design, which allows
high destruction rates and uniform UV photon flux distribution at low pressure drop. A pH-
controlled, low-profile, acid gas scrubber is integrated with the PCO reactor to remove HCI and
other chlorine-containing byproducts from the PCO reactor exhaust. Process conditions and
emissions are automatically monitored and logged. The entire unit, including controls and monitors,
is skid mounted to allow rapid setup and decommissioning at demonstration sites.
This work should identify operability, reliability, control and safety issues associated with
integration of PCO with air stripping, and will provide necessary engineering scale-up data for full-
scale operation. This information can then be used by process development and design engineers
to fully evaluate the economic viability of PCO for practical environmental remediation applications.
For More Information: Richard Miller, IT Corporation, 312 Directors Drive, Knoxville, TN
37923 Tel: (615) 690-3211
168
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IN SITU BiOREMEDIATION USING OXYGEN MICROBUBBLES
Douglas E. Jerger
Patrick M. Woodhull
OHM Remediation Services Corp.
16406 U.S. Route 224 East
Findlay, OH 45840
419-423-3526
Successful in situ biological treatment of groundwater and soils contaminated with hazardous
wastes depends on accelerating the biodegradation rates of the indigenous microflora. A non-limiting
supply of oxygen as the terminal electron acceptor is necessary to maintain these enhanced rates
under aerobic conditions. Techniques for the subsurface delivery of oxygen include air sparging
hydrogen peroxide, and reinjection of aerated groundwater. An innovative method under development
for in s/fr/bioremediation is oxygen microbubbles. Oxygen microbubbles are generated continuously by
mixing a concentrated surfactant stream with water under pressure. This solution is then mixed with a
continuous supply of oxygen to produce a 65% dispersion of bubbles in the 45 ± 40 micron size range
The microbubble dispersion can be delivered into a saturated or unsaturated soil matrix under pressure
through a well or trench delivery system.
One treatment scenario is to inject the microbubbles into a laminated coarse sand/clay layer
treatment zone. Contaminated groundwater flows through the treatment zone and biodegradation
occurs using the available oxygen. A second approach is to deliver the microbubble dispersion into the
vadose zone. Injection rates would depend on specific matrix conditions.
A preliminary engineering technology comparison of in situ oxygen delivery methods indicated
that microbubbles were a cost effective means to treat 10,000 cubic yards of soil contaminated with
1,000 mg/kg of petroleum hydrocarbons. Other oxygen delivery methods examined were air sparging
hydrogen peroxide, supersaturated water and aerated water.
A field scale demonstration of the oxygen microbubble technology for in situ bioremediation is in
progress at a former fire fighting site contaminated with jet fuel at Tyndall Air Force Base in Panama
City, Rorida.
i
For more information: Douglas E. Jerger, Technical Director, Bioremiediation; OHM Remediation
Services Corp., 16406 U.S. Route 224 East, Findlay, OH 45840, 419-423-3526.
169
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IN SITU VITRIFICATION: SCOPE OF POTENTIAL APPLICATIONS
James E. Hansen
Geosafe Corporation
2950 George Washington Way
Richland, WA 99352
(509) 375-0710 Fax: (509) 375-7721
In Situ Vitrification (ISV) is an innovative technology that has recently been initiated on a large-scale
commercial operation basis. The ISV technology involves electric melting of contaminated earthen
materials (e.g., soil, sediment, tailings, sludges) at high temperatures for purposes of destroying/ remov-
ing organics and volatile contaminants, and permanently immobilizing heavy metals. The product of
ISV is a glass and crystalline vitrified residual that is monolithic in nature and has outstanding physical,
chemical, biotoxicity, and weathering properties; and which has a geologic (permanent) life expectancy.
The ISV technology may be applied to contaminated materials "in situ" (where they presently exist),
or where they have been "staged" for processing. Other application variations include "stacked" pro-
cessing, where one melt is done atop another, and "layered" processing, where the contaminated
material is vitrified and removed in progressively deeper layers. The technology may also be applied in
"stationary-batch" and "stationary-continuous11 modes wherein the processing equipment remains sta-
tionary and materials to be treated are brought to a stationary location for treatment, followed by inter-
mittent or continuous removal.
The primary factors that must be considered in ISV application engineering include: 1) geochemis-
try of the material to be treated, 2) desired residual product properties, 3) contaminant types and con-
centration levels, 4) desired contaminant disposition(s), 5) media moisture content, and the possibility of
groundwater recharge to the treatment zone, and 6) presence of debris, containers, and/or structures
within the treatment zone. The technology may be adapted for a broad range of site-specific condi-
tions.
ISV has been successfully tested, and is currently planned for use, on a large number of contami-
nant types, including organics, heavy metals, and radionuclides. The technology has a unique advan-
tage in the ability to simultaneously process mixtures of contaminant types. Various media tested
include most basic soil types, including limestone and dolomite-rich soils, uranium mill tailings, ocean
harbor sediments, and process tailings containing glass forming oxide materials.
For More Information:
James E. (Jim) Hansen
Geosafe Corporation
2950 George Washington Way
Richland, WA 99352
(509) 375-0710
FAX: (509) 375-7721
170
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LOW TEMPERATURE IN-SITU THERMAL DESORPTIQN OF ORGANICS FROM SOILS
Phillip N. La Mori
NOVATERRA, Inc.
2029 Century Park East
Suite #890
Los Angeles, California 90067
(310) 843-3190
In-situ soils remediation has many advantages over ex-situ
remediation because it remediates the soils without removal from
the ground, does not transport soils to another location and, when
applied with proper controls, does not impact on the local
environment. Several Approaches are commercially available for
in-situ soils remediation, e.g. hot air, steam stripping (HASS),
soil vapor extraction (SVE), stabilization, enhanced vapor
extraction, and others. The report describes an in-situ soil
treatment method which uses in-situ deep soils mixing combined with
the infection of steam and hot air (HASS) to remove volatile
organic compounds (VOC) and semi-volatile organic compounds (SVC).
2°^f aifL and steam are injected into the soil from mixing blades
below the surface. VOC and SVC are heated by the steam and carried
to the surface with air where they are collected in a shroud for
treatment and subsequent disposal. A unique feature of this
technology is that the below ground removal occurs not only bv
heating and vaporization, but also by the formation of organic
compounds - steam azeotropes. These azeotropes facilitate the
removal of the organic species. The limitation in using this
technology is, therefore, the thermal desorption of VOC and SVC
from soil. Examples of thermal desorption as a first order rate
process are given from field studies. The results of a 30,000 yd3
commercial project which received regulatory approval are also
presented. This project was part of a 1990 USEPA Site Report.
This technology has application at sites where it is best
suited. These are: i) . soils where both the vadose and saturated
zones need remediation; 2). soils below the water table; 3). soils
which have strata of varying permeability; and, 4) . removal of hot
SP°J? .in Sltes which can use more than one treatment approach. Use
of this technology requires open areas and sites with manageable
underground obstructions.
For more information contact Phil La Mori of NOVATERRA, Inc.
Jnn^029 Cen^urv Park East' Suite 890, Los Angeles, California
90067, or call (310) 843-3190.
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PHOTOCATALYTIC REMEDIATION OF PCB-CQNTAMINATED
WATERS AND SEDIMENTS
Pengchu Zhang and Ronald. J. Scrudato
Research Center, State University of New York at Oswego, Oswego, NY 13126
The degradation of polychlorinated biphenyls (PCBs) hi aqueous solutions, clay and
sediment suspensions was promoted by sunlight hi the presence of TiO2 as a catalyst. After 4
h irradiation, 83 and 81% of total PCBs were decomposed hi the water solution and clay
suspension, respectively. About 67% of the total PCBs was degraded hi the sediment suspension
after 6 h irradiation, while it took 4.5 h to decompose 98% of the total PCBs in the aqueous
phase of the sediment suspension. It was observed that the lower chlorinated PCB congeners
underwent the highest rate of decomposition in the aqueous systems. Study results indicate that
photocatalytic processes have the potential to be an efficient and low cost technique to remediate
PCB-contaminated water and sediment.
A bench-top photoreactor was built and currently is used to determine the variables for
photocatalytic processes. Two pilot-scale photoreactors are under design and construction to
remediate the PCB-contaminated soil from a casting site and sediments from a federal superfund
site.
For more information:
Pengchu Zhang
Ronald J. Scrudato
Research Center
State University of New York College at Oswego
Oswego, NY 13126
(315)341-3639
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PHOTOLYSIS/BIODEGRADATION TREATMENT OF PCB and PCDD/PCDF CONTAMINATED SOILS
Edward S. Alperin and Arie Groen
IT Corporation
304 Directors Drive
Knoxville, Tennessee 37923
(615)690-3211
The primary project objective of this study was to perform a laboratory-scale evaluation and
demonstration of two-stage detoxification process for the treatment of soils contaminated with
polychlorinated biphenyls (PCBs), polychlorodibenzodioxins (PCDDs) and other chlorinated
aromatics. Earlier work showed a practical rate of photolytic destruction of PCBs and 2,3,7,8-
tetrachlorodibenzo-p-dioxins (TCDDs) on soil when the soil surface was treated with a surfactant
solution and irradiated by ultraviolet (UV) light. It is expected that such a treatment would produce
photolytic by-products that would be less resistant to further degradation by biological treatment.
The first stage of this process involved in situ photolytic degradation by periodic tilling, application
of a surfactant, and irradiation of the soil surface for up to 30 hours. After photolysis, the second
stage consisted of the soil being re-inoculated with indigenous microorganisms enriched from the
original soil and supplied with nutrients to cause in situ biodegradation of less recalcitrant
contaminants.
The results of the initial experiments indicate that the ability of surface irradiation to destroy PCBs
or TCDDs depends on the soil type. Soils with higher content of humic materials or clay were less
successful than on sandy soil. Natural sunlight was also found to be ineffective. Surface
irradiation was found to remove chlorine from the highly substituted PCBs and form the bi and tri
chlorinated PCBs. The initial biotreatment studies show that these compounds are more readily
degraded.
For More Information:
Edward S. Alperin
IT Corporation
304 Directors Drive
Knoxville, Tennessee 37923
(615) 690-3211
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PNEUMATIC FRACTURING OF LOW PERMEABILITY FORMATIONS
John R. Schuring
Hazardous Substance Management Research Center
New Jersey Institute of Technology
Newark, NJ 07102
(201)596-5849
Uwe Frank
U.S. EPA
2890 Woodbridge Avenue
Edison, NJ 08837-3679
(908)321-6626
John J. Liskowitz
Accutech Remedial Systems, Inc.
Cass Road at Route 35
Keyport, NJ 07735
(908) 739-6444
Herbert S. Skovronek
Science Applications International Corp.
Hackensack, NJ 07601
(201)489-5200
Pneumatic fracturing is an innovative technology which enhances the in situ removal and
treatment of volatile organic compounds (VOC's) in low permeability soil and rock formations. The
process may be generally described as injecting air into a contaminated geologic formation at a pressure
which exceeds the natural in situ stresses, and at a flow rate which exceeds the permeability of the
formation. This causes failure of the medium and creates a fracture network radiating from the injection
point. Once established, the fractures enhance the permeability of the formation, thereby increasing the
flow rate of vapors and liquids through the formation for more efficient contaminant removal or treatment.
During August 1992, the U.S. EPA sponsored a Superfund Innovative Technology Evaluation
(SITE) field demonstration of the Pneumatic Fracturing Extraction (PFE) process at an industrial site in
Hillsborough, N. J. For the demonstration, PFE was used to enhance a soil vapor extraction system
installed in the low permeability siltstones and sandstones underlying the site. The test results showed
that PFE significantly improved the ability to extract trichlorethyiene (TCE) and other VOC's from the
formation. Extracted air flow increased from 400% to 19,000%, and the TCE mass removal rate
increased from 700% to 2,300%, depending on the testing configuration. An extended vacuum radius of
influence was also observed, which will result in a reduction of the number extraction wells required to
remediate the site. The application of PFE should decrease remediation time, and in the case of this site,
eliminate the need to excavate or encapsulate the source area.
Work is continuing to expand the applications of pneumatic fracturing to other in situ technologies
such as pump and treat, bioremediation, and thermal treatment. Experience is now available in both the
vadose and saturated zones, and in several geologic formations including clay, silt, silty sand, cemented
sand, fill, sandstone, and siltstone.
For more information: Uwe Frank, U.S. EPA, 2890 Woodbridge Avenue, Edison, New Jersey
08837-3679, Phone: (908) 321-6626.
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THE REACTOR FILTER SYSTEM: AIR TOXICS CONTROL
FOR SOIL THERMAL TREATMENT PROCESSES
Neil C. Widmer and Jerald A. Cole
Energy and Environmental Research Corporation
18 Mason, Irvine, California 92718
(714)859-8851 fax 859-3194
Much of the materials from Superfund sites are sludges, soils and sediments which are contaminated
with both toxic organic chemicals and toxic metals. Currently available thermal treatment systems for
detoxifying these contaminated media may release products of incomplete combustion (PICs) and
volatile toxic metals. Extensive air pollution control devices (APCDs) are then required to prevent release
of air toxics to the atmosphere. Because of physical size and utility requirements APCDs are frequently
not suitable for transport and remote installation at Superfund sites. The Reactor Filter System (RFS) is
designed to avoid some of the logistical problems associated with conventional APCDs . The RFS will
exploit the potential for a fabric filter installed immediately downstream of a thermal treatment process to
capture toxic metals, particulate matter and unburned organic solids. The RFS process involves three
steps:
1) Thermal treatment of the soils, sludges or sediments in a primary chamber that could be any
one of a number of devices including a rotary kiln, fluidized bed unit, or other chamber
designed to thermally treat sludges or solid materials.
2) Injection of a low cost sorbent containing silicates, such as kaolinite, into the flue gases at
temperature near 1300 °C (2370 °F). These sorbents will react with volatile metal species such
as lead, cadmium, selenium and arsenic in the gas stream forming insoluble (nonleachable)
silicate complexes similar to cementitious species.
3) Fabric filtration using an advanced high temperature (up to about 1000 °C, 1830 °F) filter
medium designed to provide additional time for the sorbent particles to react with the metals
and provide additional time for the destruction of organics that are associated with the
particulate matter. Because of the well established relationship between PIC formation and
particle chemistry, this process can virtually eliminate polychlonnated dioxin formation
For More Information: Jerald A. Cole, Manager, Fundamental Research, Energy and Environmental
Research Corporation. 18 Mason, Irvine, California 92718. (714)859-8851 fax 859-3194.
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REDUCTIVE PHOTO-DECHLORINATION OF HAZARDOUS WASTES
Moshe Lavid, Suresh K. Gulati and Moisey A. Teytelboym
M.L. ENERGIA, INC. ,
P.O. Box 1468, PRINCETON, NJ 08542
(609) 799-7970; fax (609) 799-0312
Waste streams containing hazardous chlorinated hydrocarbons
are treated with an innovative process designated "Reductive
Photo-Dechlorination" (RPD). This RPD process uses ultraviolet
light in a reducing atmosphere to remove chlorine atoms from
organo-chlorine waste streams at low to moderate temperatures.
Because chlorinated organics are destroyed in a reducing
environment under mild conditions, process products include
environmentally benign hydrocarbons and hydrogen chloride.
The RPD process is designed specifically to treat volatile
chlorinated wastes in the liquid or gaseous phase. Applications
include in-situ treatment of wastes discharged from soil venting
extraction (SVE) operations, and in-situ regeneration of
activated carbon canisters saturated with chlorocarbons. The
process can also be used for direct treatment of off-gas streams
containing chlorocarbons as well as for pretreatment of gas
streams entering catalytic oxidation systems, reducing chlorine
content and hereby protecting the catalyst against poisoning.
This poster will focus on photo-thermal remediation of
1,1,1-trichloroethane (TCA) yielding greater than 99% conversion.
It will describe bench-scale experimental results, kinetic
modeling predictions, and selected design parameters for an on-
going pilot-scale demonstration unit employing a unique UV lamp.
The RPD process was developed under the EPA/Small Business
Innovation Research (SBIR) program, and in late 1992'was accepted
to the EPA-SITE Emerging Technology Program.
For more information please contact:
Dr. Moshe Lavid
M.L. ENERGIA, INC
P.O. Box 1468
Princeton, NJ 08542-1468
(609) 799-7970 Voice
(609) 799-0312 Fax
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REMEDIATION OF CHLORINATED VOLATILE ORGANIC COMPOUNDS
IN GROUNDWATER USING THE ENVIRQMETAL PROCESS
John Vogan, EnviroMetal Technologies Inc., 42 Arrow Road,
Guelph, Ontario, Canada, N1K 1S6
Stephanie O'Hannesin, University of Waterloo*
Waterloo, Ontario, Canada, N2L 3G1
William Matulewicz, James C. Anderson Associates Inc.,
907 Pleasant Valley Avenue, Mount Laurel, NJ 08054
John Rhodes. Rhodes Engineering, 505 South Lenola Road, Moorestown, NJ 08057
Historic discharges of spent chlorinated industrial Solvents resulted in groundwater contamination
at a small industrial site in Wayne Township, New Jersey. Dissolved chlorinated volatile organic
compounds present in the shallow bedrock aquifer include tetrachloroethene (PCE) at concentrations of
10 to 20 mg/L, and trichloroethene (TCE) at concentrations of up to 1 mg/L. The use of the EnviroMetal
process (metal enhanced reductive dehalogenation) is being evaluated as an innovative technology
alternative to a conventional pump and treat system.
Bench scale studies were completed to confirm that the PCE and TCE in the groundwater would indeed
be degraded using this technology, and to develop design parameters for field application. Groundwater
from the site was pumped through laboratory columns containing the reactive media (metallic iron and silica
sand). Half-lives (the time required to remove one-half, the contaminant mass) of 0.4 hours for PCE and
0.5 hours for TCE were measured in columns containing 100% reactive iron. Small amounts (less than
10%) of cis-1,2-dichloroethene and vinyl chloride were produced as a result of PCE and TCE degradation
but these also subsequently degraded. '
Based on these favourable results, an above-ground pilot-scale field test will be initiated this year at the
facility. If successful, this will be followed by installation of a full-scale in-situ treatment zone in the shallow
bedrock.
For more information, contact John Vogan, EnviroMetal Technologies inc., 42 Arrow Road, Guelph, Ontario,
Canada, N1K 1S6. EnviroMetal Technologies Inc. acknowledges the support of SL Industries of Mount
Laurel, New Jersey in contracting for the EnviroMetal process to be demonstrated at this site.
177
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,TM
REMOVAL OF DISSOLVED HEAVY METALS USING FORAGER SPONGE
Norman B. Rainer, Ph.D.
Dynaphore, Inc.
2709 Willard Road
Richmond, VA 23294
(804)288-7109
Forager™ Sponge, comprised of a chelating polymer disposed within an open-celled cellulosic
matrix, selectively absorbs multivalent heavy metals in cationic and anionic states. The following
affinity sequence is generally exhibited:
Cd"
AsO4**+
This affinity sequence enables the Sponge to abstract trace quantities of heavy metals in the
presence of vast concentrations of commonly abundant ions such as Na, Ca, Al and Mg. Certain metal
ions can be removed to non-detectable levels. The Sponge is not adversely affected by dissolved
organics, oils, or suspended matter. In fact, the Sponge can be utilized to remove metals from thick
sludges.
In the form of V2" cubes, the Sponge is employed in columns, fishnet enclosures, rotating
drums, or stirred tanks. In column operations, removal efficiencies range to 99% at flow rates of 0.1
bed volume/minute.
The Sponge is used to remediate groundwater by either pump-and-treat operations employing
absorption columns, or by in situ operations wherein fishnet enclosures containing the Sponge are
emplaced vertically within wells, or horizontally within trenches. When saturated with metals, the
enclosures are retrieved, and replaced with fresh units. The in situ technique involves no capital
investment and does not require electrical power.
Because fishnet containers filled with the Sponge present essentially no impedance to flow of
water, they are also suited for use in stormwater treatment.
The metal-saturated Sponge can in some instances be eluted and re-used. Alternatively, the
saturated Sponge can be incinerated or compacted to an extremely small volume to facilitate disposal.
The cost effectiveness of the Sponge is dependent upon factors such as the nature of the
metals absorbed, the total chemistry of the water, number of cycles of use, and ultimate disposal
method. In general, costs may range between about 100 and 90C per gram of metal removed.
For More Information: contact N. B. Rainer at the above address.
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REMOVAL OF ORGANICS FROM SOILS USING CF SYSTEMS®SOLVENT EXTRACTION TECHNOLOGY
Susan Erickson
John Maddewicz
CF Systems
3D Gill Street
Woburn, MA 01801
(617) 937-0800
CF Systems patented soil treatment process involves the use of liquified gases as solvents to extract
and separate organic contaminants from soils and sludges. The unique physical properties of liquified
gas solvent, such as their low viscosities, densities and surface tensions, result in significantly higher
rates of extraction compared to conventional solvents. These enhanced physical properties also
accelerate the rate of gravity settling of the soil/solvent mixture following extraction of the organics,
which broadens the applicability of the process to include the treatment of line clays and silty sediments.
This paper discusses the results of several bench- and pilot-scale treatability studies, using CF
Systems Solvent Extraction process, to remove organic contaminants from a variety of soil types.
Technical data will be presented from treatability studies performed on samples from various Superfund
Sites including wood treating sites, PCB contaminated sites, and pesticide/dioxin contaminated sites.
The discussion will include the significance of process operating variables and the effect of different
solvents/co-solvents on the removal efficiency.
Regulatory agencies use a variety of factors, such as risk to human health, future use of the site, and
type of organic contaminant, to set the remedial goals for a contaminated site. CF Systems has
successfully demonstrated its ability to achieve the required treatment goals for a wide range of organic-
contaminants in a variety of soil matrices. As a results of bench and pilot-scale work performed at one
particular Superfund site, CF Systems has been awarded a contract to remediate 95,900 tons of
creosote contaminated soil.
For More Information: Susan Erickson, CF Systems, 3D Gill Street, Woburn, MA 10801, (617) 937-
0800
179
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The Rochem DT process
The Rochem DT process is a membrane separation technology which allows the
removal of hazardous constituents from water. The technology is a concentration
process for the volume reduction of hazardous materials.
The patented Disc Tube system consists of a series of membrane cushions stacked
between spacer discs. The membranes and discs are then inserted into a pressure
vessel to allow operation at high pressures. The open channel flow path and the
hydraulic design of the module allow efficient operation with minimal fouling.
When fouling does occur, the module cleans easily and completely, without
disassembly.
Originally developed for desalinating water, Rochem currently has commercial
systems treating landfill leachate at over 25 landfills in Europe. The first installation
has operated successfully since 1988. The largest installation to date processes in
excess of 1 million gallons per day of leachate discharging 98% of the stream as
purified water. The hazardous components are concentrated to 2% of their original
volume, solidified and returned to the landfill.
The Disc Tube system is currently in use at the French Limited Superfund site in
Crosby, Texas. This unit, which lias been in operation since May, 1993, discharges an
average of 120 gallons per minute of water directly into the San Jacinto River at a
fraction of the cost of alternative means.
A SITE demonstration is scheduled for early summer.
The poster will give a complete description of the technology and will include
analytical data from both French Limited and leachate processing.
For further information, please contact:
Mr. David LaMonica
President
Rochem Separation Systems, Inc.
3904 Del Amo Blvd., Suite 801
Torrance, CA 90503
Tel:(310)370-3160 Fax:(310)370-4988
Mr. Ken Miller
President
Rochem Environmental, Inc.
4721 Garth Road
Baytown, Texas 77521
Tel:(713)420-1408 Fax:(713)420-1408
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SAREX* CHEMICAL FIXATION PROCESS
FOR ORGANIC CONTAMINATED SLUDGES AND SOILS
Bradford H. Miller, William J. Sheehan
Separation and Recovery Systems, Inc.
1762 McGaw Avenue, Irvine, California 92714-4962
Telephone 714-261-8860
The SAREX® Chemical Fixation Process (CFP) is a lime-based process that utilizes a
physical-chemical reaction between proprietary reagents and the hydrocarbon, water, and solids to
produce a physically stable waste product resistant to chemical leaching. Additionally, a heat of hydration
reaction between the lime and interstitial water promotes volatilization of volatile organic compounds
(VOCs).
CFP is ideally suited for heavy organic sludges and soils that also contain elevated levels of
metals. Typical applications include lube oil acid sludges, refinery sludges, tars, F-waste plating sludges,
and halocarbon/metal-impacted soils.
CFP can be utilized either in an "open" or "closed" process configuration. The "open"
configuration is ideally suited for materials that have minimal volatile emissions. The "closed"
configuration is ideally suited for materials where VOC emissions need to be contained. The "closed"
process includes a material feed and slurry system, followed by a secondary reagent feed and mixing
system. Vapors (moisture, organics, and particulates) are captured in a specially designed vapor
recovery system (VRS). The VRS contains direct contact cooling, condensation, and vapor phase carbon
polishing.
SRS has successfully treated over 30,000 cubic yards of waste using the SAREX® CFP. In all
cases CFP rendered the oily wastes into a treated soil-like product with favorable construction and
compaction properties. Recent bench-scale testing on sludge and soil samples have resulted in over 98
percent removal of benzene and trichloroethene (TCE) to levels meeting necessary treatment objectives.
SRS will conduct the SITE demonstration for CFP at a New Jersey Superfund site in the summer
of 1994. This site contains surface impoundment sludges containing elevated concentrations of VOCs,
semiVOCs and metals.
For More Information Contact:
Brad Miller
Separation and Recovery Systems, Inc.
1762 McGaw Avenue, Irvine, California 92714-4962
714-261-8860
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SITE EQ5: REMOVAL OF HEAVY METALS WITH A CENTRIFUGAL JIG
Wallace D. Henderson
Charles R. Hellman
TransMar, Inc., 1936 East 23rd Avenue, Spokane, Washington 99203
Phone (505) 856 - 5510
Gordon Ziesing
Montana Tech
TransMar, Inc. is the owner of all rights and patents for the Campbell Centrifugal Jig
(CCJ) which is a major advance in well proven technology for gravity separation of fine
heavy metal particles from background material. The CCJ is a combination of two widely
used methods of heavy particle separation - jigging and centrifuging. Mineral jigs have been
used for many years to separate solids of different densities in a fluid medium through gravity
induced differential settling. For heavy particles (> 150 microns) the standard gravity jig has
the advantage of high capacity and continuous material flow. However, it is ineffective for
finer particles which tend to remain suspended in the fluid. Centrifuges are very effective in
separating solids from liquids, but not for the differential separation of solids in a slurry.
The CCJ combines the effectiveness of the continuous flow of the standard mineral jig
with the high "g" forces of the centrifuge to effectively segregate and concentrate particles
from 150 microns down to 1 micron, if they have a specific gravity at least 20% greater than
the background material. No chemical are needed to effect separation. Slurry material is fed
to the CCJ through a vertical hollow shaft and is thrown radially outward by the vanes on a
diffuser plate which distributes it over the rotating screen which is covered with oversize
material to make a "bed". This bed is intermittently fluidized by pulses of water in a
direction opposite to the "g" force and acts as a one way valve for heavy particles. Heavy
particles migrate through the bed and screen and enter the hutch to be recovered through the
discharge ports as concentrate. Lighter particles are flushed downward across the jig bed and
become tailings. The CCJ was originally developed for fine gold recovery. However, it has
demonstrated the capability to separate and concentrate a wide variety of materials ranging
from 28x100 mesh pyritic sulphur in fine coal cleaning down to 1 micron particles in gold
recovery. In recent DOE sponsored experiments it demonstrated concentration ratios of over
100:1 in removing a bismuth surrogate for plutonium, from Nevada Test Site soil.
The EOS Grant was made to Montana Tech and is being conducted in their Research
Facility by Montana Tech and TransMar in conjunction with Hydro Processing and Mining,
Inc. the operator of the facility. Materials from four different sites - Ramsey Flats, Colorado
Tailings, Cyprus Tailings and the Contact Tailings have been tested to date. Ramsey Flats
material was unsuitable because the contained Cu,Pb, and Zn were present as alteration
/oxidation products and not liberated from the gangue.The Colorado and Cyprus tails posed
similar problems. Much better results were obtained with the Contact Tailings from
Phillipsburg, MT. Preliminary results are encouraging with recovery of 64% in a single pass
and 77% in two passes (rougher with 20 mesh and scavenger with a 50 mesh screen). To
obtain these results required changing the CCJ screen from 50 to 20 mesh since heavy metals
constituted 13.3% of the feed. Testing is continuing on similar "Block P Tailings" from near
Monarch, MT.
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SPOUTED BED REACTOR
Richard Koppang
Energy and Environmental Research Corporation
18 Mason
Irvine, CA 92718
(714) 859-8851
,. . .The Spouted Bed Reactor (SBR) technology utilizes the unique attributes of the "Spoutinq"
fluidization regime, which can provide heat transfer rates comparable to traditional fluid beds while
providing robust circulation of highly heterogeneous solids, cohcurrent with very ag^essK/Tcomminution
(particle size reduction through abrasion). The primary spouted bed provides a zone for volaSion
pyrolysis and gasification reactions. The gaseous products can then be applied to highly efficient
n«S« Teii nJn c?nventi°nal combustion equipment or, alternatively: gasification products can be
used as syn-fuel or chemical products can be recovered through synthesis of the off qas Thus
gasification provides much greater opportunity for product recovery through Advanced Recycling.
iH«m=i
solids remain
r@3ctions.
beS-n constructed consisting all of the critical system components. Solids
t. & medlum temperature 0 000-1600°F) in a primary vertical reactor. Large
the bed until they are reduced in size through attrition, pyrolysis, and gasification
Steam is used as the spouting fluid, highly superheated by a small in-line oxy-fuel burner
buperneated steam provides heat for endothermic pyrolysis reactions, along with partial oxidation of
wastes which react with sub-stoichiometric levels of oxygen injected into the .spouted bed fprtrnaryl
i«u» £t£eJ?re8eJ1C8 of e?cess st!am at h'9h temperature, toxic organic compounds that may result during
low or medium temperature waste pyrolysis are reduced to H2, CO, CO2, and H2O. Subsequent
purification of the Ha/CO/CC-2 gas stream can be accomplished using conventional paniculate and
scrubbing technologies.
fi^1"9 tec.hnol°9y is primarily applicable to waste with significant heat content
«nn rom n onSnt0D,IC organic c°mP°unds ^ heavy metals. Thei heat content of the waste may
range from 3,000 to 12.000 »u per pound. Soils contaminated with coal tar residues, petroleum refinery
Sfm' rnh ™n'f 'Pal f°lld Wa**teS are /PPropriate for processing in the SBR Advanced Recycling ,
system. Chemical waste, munitions and rocket propellants are also candidate feed materials.
«« Ji^SflSl?Sie*rrts '? d|JfDhf v^1i!1cluded.fne des'9n' construction, shakedown, and preliminary
operation of a pilot scale SBR facility capable of processma 1000-1500 Ib/hr of waste Trouble-free
feeding of "raw" unsegregated Auto Shredder Residue (ASR) plastics has been accomp Shed at a feed
rf ! QD1t4
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STEAM ENHANCED EXTRACTION FOR IN SITU SOIL
TREATMENT
AND GROUND WATER
Kent S. Udell
Berkeley Environmental Restoration Center
6165EtcheverryHall
University of California, Berkeley, 94720 (510)642-2928
Roger Aines, Robin Newmark
P. O. Box 808, L-219
Lawrence Uvermore National Laboratory
Livermore, CA, 94550
(510) 423-7184, (510) 423-3644
The acceleration of recovery rates of second phase liquid contaminants from the subsurface during
gas or water pumping operations is realized by an increase in soil temperature. Of the various methods of
delivery of thermal energy to soils and ground water, steam injection appears to be the most economical
and versatile technique for soils with sufficient permeability. The use of steam injection to recover volatile,
semi-volatile, and non-volatile contaminants from the subsurface also allows the exploitation of various
thermodynamic and hydrodynamic mechanisms. These mechanisms include vaporization of liquids with
boiling points below that of water, enhanced evaporation rates of semi-volatile components, physical
displacement of low viscosity liquids, dilution and displacement of aqueous contaminants, and removal of
residual contaminants from low permeability zones by depressurization and vacuum drying.
A recently completed field-scale demonstration of the patented steam enhanced extraction
technology to remove gasoline at a site at Lawrence Livermore National Laboratory confirms the
effectiveness of this technique and its applicability to contaminants found above and below the water
table. Approximately 90,000 cubic meters of soil were treated with this process. Steam was injected into
six wells surrounding the plume. The steam injection could occur in each well at two different locations:
one in the vadose zone and the other below the water table. After 35 days of injection, the target soils
were at a relatively uniform temperature of 100° C. Gasoline extraction rates were limited by the
aboveground gaseous phase treatment system. Approximately 1,700 gallons of gasoline were
recovered.
An additional 25 days of cyclic steam injection was then applied to the site with continuous pumping
of vapors and liquids for a period of 42 days. Recovery rates increased by an order of magnitude over that
measured during the first phase. Rates were observed to decrease during steam injection and increase
when the steam injection was intermittently ceased. This performance is attributed to steam generation
within the lower permeability zones during the depressurization mode of operation. Soil borings at the
end of this phase showed that soils both above and below the water table were clean in the high
permeability zones with residuals remaining deep in the low permeability clay zones.
A final 35 days of vacuum extraction and ground water pumping was then applied with an additional
1000 gallons of gasoline removed. Recovery rates dropped significantly during this final phase. The total
gasoline volume recovered exceeded 8000 gallons. The initial estimate of the gasoline at the site was
6200 gallons. Hydrocarbon degrading biological activity was found in the zones subjected to steam
temperatures indicating that the technology did not leave the site sterile.
For More Information: Kent S. Udell, Berkeley Environmental Restoration Center, 6165 Etcheverry
Hall, University of California, Berkeley, CA, 94720, (510) 642-2928.
184
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SULCHEM PROCESS - DESTRUCTION OF
AND STABILIZATION OF HFAVY METALS
A. Bruce King and Stephen W. Paff
Center for Hazardous Materials Research
320 William Pitt Way
Pittsburgh, PA 15238
(412) 82(5-5320
The patented Sulchem Process reacts contaminated liquids, soils and sludges with elemental sulfur
at elevated temperatures. All organic compounds react with sulfur. Hydrocarbons are converted to
an inert carbon-sulfur powdered residue and hydrogen sulfide gas. Chlorinated hydrocarbons also
produce HCI. The acid gases can be treated to recover sulfur for reuse.
In addition to destruction of the contained organic compounds, heavy metals are converted to the
sulfides and thereby rendered less leachable. Thus, the Sulchem Process offers the potential to
stabilize heavy metals in the same process step as the organics destruction.
Under a Cooperative Agreement with the U.S. EPA, under the Emerging Technologies E05 Program,
the Center for Hazardous Materials Research (CHMR) is developing the Sulchem Process for metals
stabilization and organics destruction. The process is anticipated to use two reactors. In the first
reactor, the solids are mixed with sulfur and heated to destroy organics and immobilize metals. In
the second reactor, the off-gases from the first reactor (which may contain desorbed organics) are
further reacted with sulfur to destroy the remaining organic compounds.
During the first year of the program, CHMR examined various heavy metals spiked in different soil
blends as well as soils spiked with hydrocarbons. Immobilization of heavy metals is determined by
the concentration of the metals in the Toxicity Characteristic Leaching Procedure (TCLP) leachate
compared to the EPA TCLP regulatory limits. Cadmium, copper, lead, nickel and zinc were found
to provide significant reduction in the TCLP values following treatment oif the soil by the Sulchem
Process. Copper TCLP values were reduced most effectively by this treatment. Lead TCLP values
?J?1?/«duced b?low regulatory targets when concentrations in the original soil were below about
10,000 ppm. Cadmium TCLP values were reduced below TCLP limits for runs at different process
conditions with starting concentrations ranging from below 1 000 ppm to above 3000 Dom
depending on soil type.
Tests with hydrocarbons of varying boiling points have demonstrated that a minimum reaction
oTC^atu re • 25° c is required and that for compounds with boiling points from 250 °C to about
• u u *,.e IS comPetltIon between desorption and reaction in the first stage reactor. Compounds
with boiling points below 250°C tend to desorb and will need to be treated in the second stage
reactor. Compounds with boiling points above about 320°C were effectively destroyed in the
solids reactor. Preliminary tests of this second reactor indicate it is capable of destroying organics
in the vapor phase. '•'.'.,"••.
oorJ^or!Jnformation: A' Bruce King' CHMR» 320 William Pitt Way, Pittsburgh, PA 15238, (412)
026-5320.
185
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r
THE SVVS® BIO-SPARGING TECHNOLOGY ;
Rick M. Billings and Bradford G. Billings
Billings & Associates, Inc.
3816 Academy Parkway North, N.E.
Albuquerque, NM 87109
(505)345-1116
The SVVS® biosparging technology (U.S. Patent Nos. 5,221,159; 5,277,518) was developed in
response to a requirement to cost effectively and timely remediate soils and ground water contaminated
by petroleum hydrocarbons. The technology was proven and commercially developed in New Mexico,
with original testing, theoretical concepts and design development in the late 1980's. The technology was
praised by EPA Office of Underground Storage Tanks, and was sought out by the EPA for inclusion in the
SITE program.
The SWS® technology uses both positive and negative air pressures and flows to simul-
taneously attack and remediate all phases of contamination (dissolved, free phase, soil residual and
vapors). Two processes, physical and biological are stimulated and enhanced to remediate the site. The
system can use single and multiple pumps/blowers to deliver air to injection points and remove vapors
from vacuum wells. Air is normally injected below the water table, and vacuum removal can take place in
the vadose zone. Injection/withdrawal points are placed in lines of sub-surface reactor nests throughout a
site depending upon a number of design criteria and site specific characteristics, such as depth to water,
soil permeabilities, contaminant type and extent, etc.
The SVVS® technology is now in place at over 50 hydrocarbon and chlorinated solvent sites
worldwide, with up to 100 planned and or designed, and pending regulatory approval. A typical site is
normally taken to soil and ground-water standards not arbitrary clean-up levels, within three years, a
substantial improvement over competing technologies.
For more information: Rick M. Billings, Billings & Associates, Inc., 3816 Academy Parkway North
N.E., Albuquerque, NM 87109, (505) 345-1116
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TERRA-KLEEN SOLVENT EXTRACTION SYSTEM FOR CONTAMINATED SOIL AND DEBRIS
Alan B. Cash
Terra-Ween Response Group, Inc.
7321 N. Hammond Avenue
Oklahoma City, OK 73132
(405) 728-0001
(405) 728-0016 FAX
The Terra-Ween technology employs a mobile batch process system that uses a proprietary solvent
blend at ambient temperature and pressure. Soil and debris are loaded into the system with standard earth
moving equipment. Oversized material need not be separated from finer soils. Debris up to 5 feet in length
width, and depth can be co-processed with the soil. The soil and debris are mixed with a solvent blend that
extracts contaminants from the soil. The contaminated solvent is then removed from the soil and pumped
through a proprietary separation process which removes organic contaminants from the solvent The clean
solvent is then used again in a closed loop process. The soil, with the organic contaminants removed can
then be left at the site.
The components of the solvent blend used by Terra-Ween has been approved by the US Food and
Drug Administration as food additives for human consumption. Because of this, the Terra-Ween process
is accepted not only by regulators, but also by communities with problems to solve. The technology has
been used at two Superfund sites, and has been demonstrated to the US EPA Superfund Innovative
Technology Evaluation (SITE) program, the Naval Environmental Leadership Program (NELP) and the
Chemical Regulations Branch, Office of Pesticides & Toxic Substances, US EPA.
The compounds successfully removed by Terra-Ween include PolycMorinated Biphenyls (PCBs)
Pentachlorophenol (PCP), Chlorinated Dibenzo-(p)-dioxins, Chlorinated Dibenzofurans, Polycyclic Aromatic
Hydrocarbons (PAHs), DDT, Toxaphene, Endrin, and other chlorinated pesticides.
The poster display will document findings by the EPA SITE team on the successful removal of PCS
from soils at the North Island Naval Air Station, Coroneido Island, California. For more information:
Alan B. Cash, President
Terra-Ween Response Group, Inc.
7321 N. Hammond Avenue
Oklahoma City, OK 73132
(405) 728-0001
(405) 728-0016 FAX
187
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THREE-PHASE FLUIDIZED BED BIOLOGICAL WASTE WATER TREATMENT SYSTEM
Kozo Konishi
Denka Consultant & Engineering Co., Ltd.
6-5 Goi Minamikaigan, Ichihara-shi
Chiba-ken, Japan
Tel: +81 (436) 21-5172
Akira Hirata
Waseda University
3-4-1 Okubo Shinjuku-ku
Tokyo, Japan
Introduction: The Bio-Dynactor, developed independently by Denka Consultant & Engineering
Co., Ltd, is a three-phase tluidized bed biological waste water treatment system. The system has been
in use since 1988 and has handled the industrial waste water of eight types of industries at 17
locations. The picture shows a Bio-Dynactor with a net volume of 300m3 installed at a paper mill. The
treated water capacity of this Bio-Dynactor is 12,000m3.
Purpose: The Bio-Dynactor is designed to be a compact unit using a simple system to supply
general waste water treatment with no maintenance, and low initial and running costs. The unit's
mechanisms are explained in a structural diagram.
Methodology: Independently developed carriers that immobilize bacteria consist of composite
particles of inorganic powder and polymer. A model of the carrier and a table of the particle
characteristics are shown.
Applications: The Bio-Dynactor is designed to meet specific needs and is capable of a variety
of functions including direct processing of source water, microorganism neutralization, chemical and
microorganism coagulation, sludge-less simultaneous removal of heavy metals, denitrification,
dephosphorization, and decoloration. The basic block flow diagram and engineering data are shown.
The bacteria immobilizing particles are used in the biological odor removal equipment of public sewage
plants at five locations.
Results: The first apparatus won the Presidential Award for Excellence of the Japan Industrial
Machine Industry Association. A comparison between this unit and other methods is shown.
Conclusion: The Bio-Dynactor technology has been well received both in Japan and
internationally. The technology has been licensed to two domestic manufacturers, and three Korean
engineering firms are in the process of negotiating its acquisition.
For more information please contact:
Kozo Konishi
Denka Consultant & Engineering Co., Ltd.
6-5 Goi Minamikaigan, Ichihara-shi
Chiba-ken, Japan
Tel:+81 (436)21-5172
188
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o !?J£jyENT OF HIGH CONCENTRATION INDUSTRAL NOx WASTE GAS BY
DRY METHOD
Zhiquan Tong
Department of Chemical Engineering
Xiangtan University
Xiangtan, Hunan
PR China
Tel: (0732) 292504
In industry, the catalyst production, metallic surface treatment and some other nrtridina
processes often generate a large amount of high concentration NOx waste gas. NOx is one of
h! S'S?1tS^N
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TREATMENT OF MIXED WASTE CONTAMINATED SOIL
Edward S. Alperin, Ronald L. Anderson, Stuart E. Shealy
IT Corporation
304 Directors Drive
Knoxville, Tennessee 37923
(615) 690-3211
Mixed waste represents one of the most challenging waste treatment and disposal problems.
Traditionally, hazardous and radioactive materials have been regulated by separate agencies and
federal and state regulations. A result of this situation is that there are disposal options for
hazardous waste or for low level radioactive waste but no disposal options for combined or mixed
wastes.
Soil contaminated by both hazardous and radioactive constituents are a significant fraction of the
mixed waste problem in the United States. Contamination by these substances has resulted from
disposal of waste residues to the land and from accidental spills and leaks at many of the
Department of Energy, Department of Defense, electrical generation and industrial manufacturing
facilities. The technologies, to be evaluated in this pilot program, thermal desorption, gravimetric
separation and water treatment with ferrate ion, provide simple, cost effective methods of
removing from soil three contaminant classes found at these sites. The removal of these
contaminants, hazardous organics, radionuclides, and heavy metals, will allow the decontaminated
soil to be left at the site. The contaminants are collected as concentrates for recovery or off-site
disposal at commercial hazardous or radiological waste facilities. The focus of the project is on the
many sites where all three types of contamination exist; the data generated will also be applicable
to sites with only one type of contamination.
This project includes both bench- and pilot-scale testing of the three technologies. While bench-
scale testing will require less than 10 kilograms of soil, up to 1000 kilograms will be needed for the
pilot-scale work. The soil for these tests will be obtained from the RCRA storage facility for .the Y-
12 oils land farm soil at the DOE Oak Ridge Facility. This material contains hazardous organics,
heavy metals, and radionuclides.
The goal of the bench-scale tests is to identify optimum operating conditions and performance for
the various treatment technologies. The pilot-scale tests will provide additional performance and
scale-up data needed for evaluation of the potential for full-scale application of these technologies.
For More Information: Edward S. Alperin
IT Corporation
304 Directors Drive
Knoxville, Tennessee 37923
(615) 690-3211
190
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Treatment of Wood-Preserving j/i/asje by Ugnin-Dedradina Fungi
John A. Glaser, Ph.D.
United States Environmental Protection Agency
Risk Reduction Engineering Laboratory
26 W. Martin Luther King Drive
Cincinnati, Ohio 45268
The abilrty of lignm-degrading fungi to detoxify by means of degradation or transformation a wide
range of hazardous organic pollutants has provoked research leading to a more complete
understanding of the use of these organisms in soil remediation technology As part of a
comprehensive program to judge the merits of the emerging fungal technology, a series of three field
evaluations have been undertaken/The last two studies were conducted at the former Brookhaven
Wood Preserving Facility located 70 miles south of Jackson, MS.
The first of these two studies, completed in 1991, was designed to evaluate the performance of a
number of selected fungal strains to degrade pentachlorophenol (POP) and the polynuclear aromatic
hydrocarbons constituents of creosote. Treatment by an inoculum of Phanarochaete sorriiriq
demonstrated the largest decrease in the PCP concentration (89%) in soil having an initial
concentration of 672 mg/Kg PCP. Loss observed in the "no treatment" control was 14% of the initial
PCP concentration.
The following year, the fungal technology was testad in a twenty-week demonstration at the
Mississippi site employing the P. sprdida treatment. Initial soil concentrations ranging from 1058 mg/Kg
to 1210 mg/Kg PCPwere encountered for this study. 'The field study design was composed of three soil
bed plots: one 30.5 m by 30.5 m (treatment plot) and two 7.6 m by 15.25 m (control plots) The
treatment plot received an application of P.. sprdida at a rate of 10% inoculum to soil on a dry weight
basis. One control was a "no treatment" control, and Ihe other control was (amended with the sterile
standard substrate (solid growth substrate for the fungal inoculum) at a rate of 10% on a dry weiaht
basis. ' •
After 20 weeks, the PCP concentration in the treatment plot was decreased by 64% whereas
decreases of 19% and 30% were observed for the "no treatment" and "sterile substrate" controls
respectively Assessment of viable fungal biomass by means of an ergosterol assay on the soil at the
beginning of the study showed a significantly diminished quantity of fungal biomass leading to a lag in
and a reduction of treatment. Weather was another significant factor in this field evaluation Excess
precipitation prohibited tillage of the experimental plots on the prescribed schedule which led to poor
aeration of the soils on occasion.
For More Information: John A. Glaser, Ph.D., United States Environmental Protection Agency Risk
Reduction Engineering Laboratory, 26 W. Martin Luther King Drive, Cincinnati, Ohio 45268,
(513) 569-7568.
191
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TREATMENT ON SOILS CONTAMINATED WITH HEAVY METALS AND VOCs
Edward S. Alperin, Ken G. Sadler, Stuart E. Shealy
IT Corporation
304 Directors Drive
Knoxville, Tennessee 37923
(615)690-3211
Metals and volatile organic compounds (VOCs) are two types of contaminants that are often found
in soils at Superfund sites. Frequently, soils are contaminated with both metals and VOCs. Since
no existing technologies address both metals and VOCs, a two-stage process is required. This
report presents the results of a bench-scale study, a pilot-plant demonstration, and an engineering
assessment for a two-stage physical separation process for the treatment of soils contaminated
with VOCs and heavy metals. Three actual Superfund soils were tested to provide performance
data for different soil matrices.
The two technologies tested were batch steam distillation for the separation of VOCs from the soil,
followed by a multistage, countercurrent extraction with hydrochloric acid (HCI) to remove the
heavy metals, and finally neutralization and precipitation of the spent acid. The treated soils, after
batch steam distillation and extraction, passed the Toxicity Characteristic Leaching Procedure
(TCLP) for volatile organics and heavy metals.
The process demonstrated a removal efficiency of greater than 95 percent for the VOCs and for
most metals, (with the exceptions being mercury, chromium, and nickel). A removal efficiency of
95 percent shows that a multistage process provides a method for remediating Superfund soils
contaminated with VOCs and heavy metals.
An engineering assessment was also performed to assess the cost of a full-scale treatment plant
using each of these technologies to treat Superfund soils. The capital cost estimated for a VOC
removal system ranged from $150IC for 500 ton/year to $670K for a 2500 ton/year system.
Operating cost for these two systems was estimated to be $300 and $230 per ton of soil. The
capital cost for heavy metals extraction was $230K for a 500 ton/year system and $990K for a
2500 ton/year system. Operating costs were $382 to $339 per ton.
For More Information:
Edward S. Alperin
IT Corporation
304 Directors Drive
Knoxville, Tennessee 37923
(615) 690-3211
192
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TWO-STAGE FLUIDIZED-BED/CYCLQNIC AGGLOMERATING COMBUSTOR
Amir Rehmat and Michael Mensinger
Institute of Gas Technology
3424 South State Street
Chicago, Illinois 60616-3896
(312) 949-3900 and 949-3730
Teri L Richardson
U.S. Environmental Protection Agency
Risk Reduction Engineering Laboratory
26 West Martin Luther King Drive
Cincinnati, Ohio 45268
IGT's two-stage combustor (AGGCOM) permits one-step treatment of soils contaminated with both
organic and inorganic compounds. The two-stage combustor combines advances in fluidized-bed com-
bustor technology with those of cyclonic combustor technology. This advanced combustor efficiently
destroys organic contaminants and encapsulates inorganic contaminants within benign, glassy agglom-
erates suitable for disposal in an ordinary landfill.
The first AGGCOM stage is a sloping-grid, agglomerating fluidized-bed reactor that can operate
under either substoichiometric or excess air conditions. In addition to the sloping grid, the first-stage
incorporates a central jet and classification section. Fuel gas and air enter the central jet while only air
is admitted through the grid and the classifier. Contaminated soils are admitted directly into the fluidized
bed. With a unique distribution of fuel and air, the bulk of the fluidized bed is controlled at a tempera-
ture of 1500° to 2000°F, while the temperature at the central jet can be varied from 2000° to 3000°F.
This feature is the key to the combustor's ability to produce benign agglomerates. Upon introduction of
contaminated soils in the bed, the organic fraction is immediately volatilized and partially combusted.
The inorganic fraction undergoes melting and subsequent agglomeration.
The volatilized organic compounds are thermally converted in the second AGGCOM stage. This
stage is a cyclonic combustor, which provides intense mixing to ensure cornpiete combustion of the or-
ganic compounds. Either secondary air or a mixture of natural gas and air is fed to this stage to
maintain a temperature in the range of 1800° to 2400°F. The destruction and removal efficiency (ORE)
of organic contaminants in this system exceeds 99.99%. Fine particulates collected in the cyclonic stage
are returned to the fluidized-bed stage for assimilation in the agglomerates.
A multiyear program is underway to develop a data base for application of the AGGCOM combustor
technology at Superfund sites. In the first phase of the program, a bench-scale unit was constructed
and operated to determine the operating conditions required for soil agglomeration. During the second
phase of the program, a 6-ton/d AGGCOM pilot plant was constructed at IGiT's Energy Development
Center with funding from EPA and IGT's Sustaining Membership Program. Shakedown has been com-
pleted and tests are in progress. This pilot plant provides a natural gas-basad thermal treatment solution
for contaminated soils and a wide variety of industrial wastes. Future efforts; will concentrate on specific
treatment demonstrations in the pilot plant.
For more information contact Michael C. Mensinger, IGT, at (312)-949-3730.
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THE ULTROX® UV/OXIDATION PROCESS
David B. Fletcher, Vice President
Ultrox Division of Zimpro Environmental, Inc.
2435 South Anne Street
Santa Ana, CA 92704-5308
Tel: (714)545-5557
Fax: (714) 557-5396
The Ultrox® process, which utilizes a combination of ultraviolet light, ozone and/or hydrogen
peroxide, can be applied to a number of groundwater, wastewater, industrial waste water, leachate and
process water problems for the removal of organic chemicals.
Though historically each component of the process has an application in drinking or wastewater
treatment, used in combination, they provide a powerful oxidizing regime which exceeds the ability of any
one of the individual components to destroy organic contaminants in water. This was successfully
demonstrated when Ultrox participated in the U.S. EPA SITE Program In 1989. Full scale installations are
currently installed at industrial sites, Superfund sites and Department of Defense and Department of
Energy locations.
The energy-efficient, low maintenance Ultrox® systems are most effective when dealing with higher
flow rates (i.e. above 50 gpm). Such difficult-to-treat man made compounds as PCBs and chlorinated
solvents, TCE, PCE, PCBs, pentachlorophenol and chlorobenzene, which are not broken down by natural
processes in the environment, are easily destroyed or converted .into non-toxic chemicals such as carbon
dioxide, water, various salts or harmless organic acids, in an efficient and cost-effective way, without
creating a need for sludge removal or off-site hauling. Other compounds which respond particularly well
to the Ultrox® process include explosives, pesticides (including DBCP), benzene, toluene, ethyl benzene,
xylene, MTBE, nitrophenols, phenols, chlorophenols, creosote, chlorinated or phosphonated PAHs, dioxin,
methylene chloride, cyanides and vinyl chloride.
If volatile organic compounds are present, Ultrox has developed a patented, low temperature,
catalytic system called D-TOX™ for destroying VOCs in air by oxidizing the compounds through the use
of ozone and a proprietary catalyst.
For More Information: David Fletcher, Ultrox division of Zimpro Environmental, Inc., 2435 South
Anne Street, Santa Ana, CA 92704-5308. (714)545-5557.
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USE OF SECONDARY LEAD SMEITFR«{ FOR THE RECOVERY nF i Fan
FROM LEAD CONTAMINATED MATERIALS
Stephen W. Paff and Brian Bosilovich
Center for Hazardous Materials Research
320 William Pitt Way
Pittsburgh, PA 1 5238
(412)826-5320
The EPA has estimated that there, are over 3,000 sites across the United States contaminated with
f£Tduat SuPe.rfund s|tes and other waste materials. The objective
. whether existing lead smelting technology could be used to recover
Iconomics containin9 between 3 and 70 Per<*nt lead, and to determine the process
Processes waste lead acid batterios using reverberatory and
^ batteries- Both the piast!?cases
the.,sr"elter reclaim«' lead from five sources of materials, including
e.*- Pnmarily battery cases, and one battery breaker/smelter site with a
variety of lead:containing materials. Batches of between 20 and 1500 tons of these materials
d WiJh ^P'03' f umace fe!fs and fed to 1:ne f"««ces, while the research team assessed
o°fna hmace ^W1 fnd performance. Two additional sets of materials, from the
of a house containing lead-based paint, as well as spent bridge blasting abrasive material
from work on a bridge coated with lead paint, were also processed in the smelter The reluks
tShe° material ^ technically feasible to use the secondary lead smelS Z ^reSm kSd Tfrom all of
CHMR also assessed the economics of using secondary lead smelters to reclaim lead from
Hpu»inn™teS' an? de^el°P9d a me.thod ^r estimating the cost of reclaiming lead. This method
develops cost as a function of material excavation, transportation and processing costs combined
-HnroH ?rnoneJltS ^Z ** ** *S* Sme^r- (In th6 form of ^covered lead, reduced fuel usage and/or
reduced iron usage). The overall remediation costs using secondary lead smelters for the sites and
materials studied varied between $57 and $230 per ton, based on current market prices for lead
were.P"maril.y a function of lead concentration, the market price for lead, distance from
nfvand, ^8 ash concentratlon In the material. Materials with high concentrations of lead
fS niflcantlv 'ess exp ensive to remediate than those with low concentrations. The cost to
remediate materials which left few slag residues in the furnace was significantly lower than the
cost to remediate materials which contained significant slagging components.
^5238
Way' Pittsbur9h' PA
195
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VITRIFICATION OF HEAVY METAL CONTAMINATED SOILS
J S Patten, Ph.D., P.J. Lucas, Ph.D., J.M. Santoianni, J.G. Hnat, Ph.D.,
Vortec Corporation, 3770 Ridge Pike, Collegeville, PA 19426, (215) 489-2255
J. St. Clair, Ph.D., DuPont Chemicals, Jackson Laboratory, Deepwater, NJ 08023
(609) 540-3674
There are currently several treatment methods available for the processing of heavy metal contaminated
soils. The most common practice is the solidification of these wastes with the addition of cement forming
reagents. The treatment of heavy metal contaminated soils via vitrification has a number of important
advantages over cementation processes, in that vitrified products have substantially superior long-term
chemical and physical stability, provide more effective resistance to leaching of the heavy metal
contaminants, and, in general, have a smaller volume relative to the waste materials being treated.
The major impediments to the use of vitrification over cementation has been the high operating costs
and relatively low operating capacities of conventional vitrification processes. Vortec Corporation, a leader
in high temperature process technology development, has developed an advanced vitrification process
which is competitive in both cost and capacity v/ith solidification processes. An important advantage of the
Vortec vitrification process is that it can be used for the treatment of soils which contain both heavy metal
and organic contaminants.
In May 1991, Vortec's technology was accepted by the U.S. Environmental Protection Agency's (EPA)
SITE Emerging Technologies Program. Vortec Corporation has now completed a two-year experimental
program to demonstrate its vitrification technology. The poster will summarize the results and conclusions
of several tests performed under Vortec's EPA SITE program. The program verified the effectiveness of
the Vortec Combustion and Melting System (CMS) to produce a fully-reacted, stable vitrified product
which immobilized the heavy metal contaminaots found in hazardous soils. The program also
demonstrated the CMS's flexibility in processing both dry and wet contaminated soils.
For More Information: Dr. John Patten, Vortec Corporation, 3770 Ridge Pike, Collegeville, PA 19426,
(215)489-2255
196
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WARREN SPRING LABORATORY SOIL WASHING PROCESS
Peter Wood, Mike Pearl, Steve Barber
Gary LeJeune, Ian Martin
Warren Spring Laboratory
Gunnels Wood Road
Stevenage
Hertfordshire
SG1 2BX
United Kingdom
011-44-438-741122
and
Mary K. Stinson
US Environmental Protection Agency
2890 Woodbridge Avenue
Edison, New Jersey 08837-3679
(908) 321-6683
Warren Spring Laboratory has developed a soil separation and washing process under the SITE
Emerging Technology Program. This poster presents resufts of a pilot scale test conducted on soil
from a gas works site that was contaminated with PAHs, petroleum hydroaarbons and heavy metals.
The soil was investigated in the laboratory to characterize the distribution oif contamination on the basis
of soil particle size, density, magnetic susceptibility and hydrophoblcity. Tills information was then used
to design the pilot-scale flowsheet
The main contaminants in the soil were: arsenic (> 30 mg/kg), lead (> 800 mg/kg), PAH (<200
mgAg) and petroleum hydrocarbons (> 600 mg/kg). The pilot scale circuit was operated for a period
of some four weeks. The nominal throughput rate was 1 ton per hour with about 40 tons being treated.
The soil was treated as a water based slurry with minimal reagents used as additives. The major
operations involved were size separation, washing and attrition, separation Ijased on combined
size/density differences, flotation and magnetic separation.
The pilot test generated the following product streams:
> 50 mm clean gravel product
10-50 mm clean fine gravel product
10 -1 mm product that may require further treatment
< 1 mm coarse sand from the hydrosizer that may require further treatment
< 10 Aim contaminated product from the hydrocyclones that will require treatment or disposal
< 1 mm - > 500 urn contaminated light gravity concentrate from screen after hydrosizer
froth concentrate with organic contamination
froth concentrate with metal contamination
magnetic concentrate with metal contamination (optional)
< 1 mm treated material.
197
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Data reduction and evaluation provides a material balance around the complete process flowsheet
for soil, individual contaminants, and process water. Performance determination for the complete
process as well as for some individual unit operations is presented. The percentage removal for each
contaminant in any clean products is determined by comparison with the original soil. For each
contaminated product stream further treatment or disposal Is recommended.
For more information:
08837, (908) 321-6683.
Mary K. Stinson, US EPA, 2890 Woodbridge Avenue, Edison, New Jersey
U.S. GOVERNMENT PRINTING OFFICE: 1994— 550-001 /8 0 3 5
198
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United States
Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, OH 45268-1072
Official Business
Penalty for Private Use, $300
EPA/540/R-94/503
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