vvEPA
United States
Environmental Protection
Agency
Hazardous Waste Engineering
Research Laboratory
Cincinnati OH 4526"8
EPA/600/8-86/017
July 1986
Research and Development
Treatment
Technology Briefs
Alternatives to
Hazardous Waste
Landfills
U.S. Environmental Protection Agency
Region V, libra,-;/
230 South Dearl-:.™ Street
Chicago, Illinois 6Cu04
-------
Acknowledgments
The descriptions of technologies, their status and applicabilities are the result of
the efforts of many contributors, notably the participants of the RCRA/CERCLA
Alternative Treatment Technology Seminars. The contributions of the following
persons are especially appreciated:
M. Amdurer E. Martin
N. Chung R. Mournighan
L. Doucet J. Nash
J. Exner D. Oberacker
H. Freeman R. Olexsey
F. Hall H. Owens
S. G. Howell C. Rogers
R. Landreth S. Taub
C. Lanker R. Traver
R. Lewis R. Turner
J. LeLacheur W. Westbrook
M. Lieberman
-------
Table of Contents
Page
Acknowledgments i
Introduction -. 1
Technology:
Advanced Biological Methods 2
Aerobic Biological Treatment 3
Air Stripping 4
Alkali Metal Dechlorination 4
Alkali Metal/Polyethylene Glycol (PEG) 5
Alkaline Chlorination 5
Anaerobic Biologial Treatment 6
Asphalt-Based Stabilization/Solidification (Thermoplastic
Microencapsulation) 7
Blast Furnaces (Iron and Steel) 7
Carbon Adsorption 8
Catalytic Dehydrochlorination 11
Centrifugation 11
Chemical Precipitation 12
Circulating Bed Combustor 14
Distillation 15
Electric Reactors 16
Electrolytic Oxidation 16
Evaporation 16
Extraction/Soil Flushing or Washing 18
Filtration 19
Fluidized Bed Incinerators 20
Fly Ash or Lime-Based Pozzolan Stabilization/Solidification 21
Fuel Blending 21
Granular Media Filtration 21
Hydrolysis 22
Industrial Boilers 22
Industrial Kilns (Cement, Lime, Aggregate, Clay) 22
Infrared Incineration Systems 23
In-Situ Adsorption (Permeable Treatment Beds) 23
In-Situ Chemical Immobilization 23
In-Situ Thermal Destruction 24
Ion Exchange 24
Liquid Injection Incineration 25
Macroencapsulation/Overpacking 25
-------
Table of Contents (Continued)
Page
Molten Glass 25
Molten Salt 26
Multiple Hearth Incinerator 26
Neutralization 26
Oxidation by Hydrogen Peroxide (H202> 27
Oxidation by Hypochlorites 27
Ozonation 27
Plasma Systems 28
Polymerization 28
Portland Cement Pozzolan Stabilization/Solidification 29
Pyrolysis Processes 29
Rotary Kiln Incineration 30
Soil Flushing/Soil Washing 30
Sorption 30
Steam Stripping 31
Sulfur Regeneration Units 31
Supercritical Extraction 32
Supercritical Water Oxidation 32
Ultraviolet Photolysis 33
Vitrification 33
Wet Air Oxidation 34
Bibliography 35
-------
Introduction
Technologies other than landfill and containment need to be applied in the
management of hazardous wastes. Acceptance of treatment technologies other
than those currently being used is slow in coming. The Hazardous Solid Waste
Act Amendments (HSWA) of 1984 modifying RCRA and the EPA policies of
CERCLA cleanups using RCRA requirements at least as guidelines will require
new approaches to the problem.
The treatment technology material included in this summary relates to
technology which is available and applicable to hazardous waste disposal now.
That is, further research is not required for application in the field. What remains
is to apply the technology and derive the necessary design parameters and the
costs for large-scale application. These derivations require, as a minimum,
pilot-scale and more appropriately full-scale application at waste disposal sites
and generator locations.
The selections of processes for presentation in this compendium is based on
opinions resulting from technical evaluation. The purpose of making these briefs
available is to remind the reader that processes and techniques are available and
to encourage a search for additional information. Information in the briefs is not
sufficient to permit direct evaluation of a process or technology. For evaluations
involving specific sites or waste streams, the reader should consult sources that
provide operational, effectiveness, and cost data.
-------
Technology: Advanced Biological
Methods
Brief Description: Two Processes—(1) Aerobic Status/Availability: Biological systems are avail-
fluidized bed (suspended sand and oxygen), to provide able.
large surface areas to improve microbial degradation
of soluble solids. (2) Membrane aerobic reactor Manufacturer: Dorr-Oliver
systems prevent loss of cell mass and thereby provide .. r
high concentrations of cells to destroy pollutants. Users ^enera^ Motors
Applicability/Limitation. Process requires prede- EPA Contact: Charles Rogers, (513) 569-7757
veloped microbes to be added to treatment systems.
Natural microbes have been demonstrated to destroy
pollutants in paint sludges.
-------
Technology:
Aerobic Biological
Treatment
Brief Description: Microorganisms metabolize bio-
degradable organics in aqueous waste. This treat-
ment includes conventional activated sludge pro-
cesses as well as modifications such as sequencing
batch reactors, and aerobic attached growth biological
processes such as rotating biological contactors and
trickling filters. Aerobic processes are capable of
significantly reducing a wide range of organic toxic
and hazardous compounds; however, only dilute
aqueous wastes «1%) are normally treatable. Recent
developments with genetically engineered bacteria
have been reported to be effective for biological
treatment of specific hazardous waste which is
relatively uniform in composition.
Applicability/Limitation: Used to treat aqueous
wastes contaminated with low levels (BOD <10,000
mg/l) of non-halogenated organic and/or certain
halogenated organics. The treatment requires con-
sistent, stable operating conditions.
Design Criteria: There are numerous variations of
the activated sludge process, however, fundamentally
the principles of the unit operations are the same. The
first step in the process involves aeration in an open
tank, in which the organic biodegradable matter in
the waste is degraded by microorganisms in the
presence of oxygen. The hydraulic detention time of
this unit operation is usually from 6 to 24 hours,
although depending on the process mode, shorter or
longer detection times may be incorporated. This is
followed by a sludge-liquid separation step in a
clarifier. Organic loading rates can vary from 10 to
180 Ibs of BOD applied per 1000ft3 depending on the
MLSS concentration, the F/M ratio, and oxygen
supply. Variations of the conventional activated
sludge system that incorporate pure oxygen or
powdered activated carbon have reported excellent
pollutant removals for typically difficult to treat waste.
Status/Availability: Commercially available.
Manufacturer: Polybac Corporation, Mike Cawthray
Detox, Inc., Evan K. Nyer (fixed film), (513) 433-7394
Ground Decontamination Systems, Joe Mahan, (201)
265-6727
Users: OH Materials, Joe Kirk, (219) 423-3526
EPA Contact: Ron Turner, (513) 569-7775
Schematic of rotating biological contactor.
Influent Wastwater
With Organic Material
CH4and CO2
i
Effluent Wastewater
With Oxidized Organics
Rotating Biological Contactor
(Courtest of Envirex)
-------
Technology: Air Stripping
Brief Description: Air stripping is a mass transfer
process in which volatile contaminants in water or
soil are transferred to air. Design considerations-
factors important in removal or organics from waste-
water in air stripping are temperature, pressure, air-
to-water ratio, and surface area available for mass
transfer. A packed tower air stripper is shown on the
next page. Practical tower diameters range from 1 to
12 ft with packing heights as high as 50 ft, air-to-
water volumetric ratios may range from 10 to 1 up to
300 to 1. The resulting residuals are the contaminated
off-gas and the "stripped" effluent.
Applicability/Limitation: Used to treat aqueous
organic wastes with relatively high volatility, low
water solubility (e.g., chlorinated hydrocarbons such
as tetrachloroethylene, and aromatics such as tolu-
ene). Limitations include concentrations of VOCs less
than 100 ppm, temperature dependence and the
presence of suspended solids.
Status/Availability: Commercially available.
Manufacturer: See buyer's guides from trade
journals.
Users: Superfund Sites: Triangle Chemical, McKin
site and Verona Wellfield
£PA Contact: Ron Turner, (513) 569-7775
Schematic of air stripping.
Organic
Vapors
Feed
Hold Down
Plate
Perforated Tray
Liquid
Redistribution
Liquid
Level
Effluent
Technology: Alkali Metal Dechlorination
Brief Description: Several chemical dechlorination
processes are based on a method developed by the
Goodyear Tire and Rubber Company in 1980. The
original method uses sodium plus naphthalene in
tetrahydrofuran (that is, sodium naphthalide) to strip
chlorine atoms from PCBs resulting in polymerizing
the biphenyl into inert condensible sludge. The
reactor is blanketed with nitrogen and an excess of
reagent to chlorine content is required. The Goodyear
Company has not commercially developed the tech-
nology. However, several companies have modified
the method by substituting their own proprietary
reagent for the naphthalene. The equipment is mobile
and can be transported on semitrailers.
Applicability/Limitation: Used to treat PCBs, ch lo-
rinated hydrocarbons, acids, thiols, chlorides and
dioxins. Moisture content adversely affects rates of
reactions.
Status/Availability: Commercially available.
Manufacturer: American Mobile Purification, Peter
Lawson-Johnson, (212) 267-7073
SunOhio, Doug Toman, (216) 452-0837
PPM, Inc., (404) 934-0902
Acurex, Jim Thompson, (415) 964-3200
Chemical Waste Management, Peter Daily, (312)
841 -8360
Exceltech, Inc., John Sedwick, (415) 659-0404
EPA Contact: Charles Rogers, (513) 569-7757
-------
Technology:
Alkali Metal/Polyethylene
Glycol (PEG)
Brief Description: In 1978 the EPA sponsored
research which led to the development of the first of a
series of A/PEG reagents which were shown to
effectively dechlorinate PCBs in oils. Essentially,
these reagents were alkali metal polyethylene gly-
colates which react rapidly to dehalogenate halo-
organic compounds of all types under ambient and
high temperature conditions. In the A/PEG reagents,
the alkali metal ion is held in solution by the large
polyethylene glycolate anion. PCBs and other halo-
genated molecules are uniquely soluble in A/PEG
reagents. These qualities combine to give a single-
phase system in which the high concentration of
anions readily displaces the halogen atoms on
halogenated molecules. The reaction of halogenated
aromatics with PEGs results in a substitution of the
PEG for the chlorine atom to form a PEG ether. The
PEG ether, in turn, may then decompose to a phenol.
The biotoxicity of reaction by-products is under
investigation.
Applicability/Limitation: Heat and excess reagent
are required for the process to function effectively in
soils containing more than seven percent moisture.
Status/A vailability:
field test.
Laboratory scale. Ready for
EPA Contact: Charles Rogers, (513) 569-7757.
Technology: Alkaline Chlorination
Brief Description: In this process, chlorine gas
(with caustic), chlorine dioxide, or hypochlorite
(sodium or calcium) are routinely used to destroy
cyanide which is converted to nitrogen gas and
carbon dioxide gas.
Applicability/Limitation: Used to treat free cya-
nides and complex cyanides although combinations
with Fe or Ni will take a longer time. Limitations
include the exothermic heat of the reaeration, pH,
non-selective competitions with other species and
additional chlorine demands. Fairly close pH control
(7.5 to 9.0) required to avoid toxic volatiles release.
Reduction efficiency about 99.6 percent.
Status /Availability: Generally available.
Manufacturer: See buyer's guides in trade journals.
Users: Electroplating industry.
EPA Contact: S. Garry Howell, (513) 569-7756.
-------
Technology:
Anaerobic Biological
Treatments
Brief Description: The anaerobic biological treat-
ment process encompasses the reduction of organic
matter in an oxygen-free environment to methane
and carbon dioxide. The most common anaerobic
attached growth treatment process is the anaerobic
filter. This process consists of a column filled with
solid media. A number of proprietary anaerobic
biotechnology processes are actively being marketed,
each with distinct features, but all utilizing the
fundamental anaerobic conversion to methane.
Applicability/Limitation: Used to treat aqueous
wastes with low to moderate levels of organics.
Anaerobic digestion can handle certain halogenated
organics better than aerobic treatment. Stable,
consistent operating conditions must be maintained.
Anaerobic degradation can take place in native soils
but when used as a controlled treatment process, an
air tight reactor is required. Hazardous organic
substances that have been found to be amenable to
anaerobic treatment include acetaldehyde, acetic
anhydride, acetone, acrylic acid, aniline, benzoic acid,
butanol, cresol, ethyl acrylate, MEK, phenol and vinyl
acetate.
Status/Availability: No mobile units are available.
Current, state-of-the-art processes available.
Manufacturer: FMC, GDS and several other pro-
viders of selected microbes, nutrients, or systems
designs.
EPA Contact: Ronald Lewis, (513) 569-7856.
Schematic of anaerobic filter system.
Influent
Wastewater
Surge Tank
-0*
Flare
To Gas Storage
Anaerobic Filter
Treated
Effluent
To Discharge or
Next Treatment
Process
-------
Technology:
Asphalt-Based Stabilization/
Solidification (Thermoplastic
Microencapsulation)
Brief Description: Involves the mixing of heated,
dried wastes within either an asphalt bitumen,
paraffin or polyethylene matrix resulting in a solid
waste mass for landfill disposal. The advantages are
waste volume reduction, low impermeability, elim-
ination of free liquid, improved handling and good
strength.
Applicability/Limitation: This method is applicable
to hazardous wastes that are complex and difficult to
treat. Wastes that should not be treated using this
technology are: wastes with high water content;
strongly oxidizing contaminants; anhydrous inorganic
salts; tetraborates; iron and aluminum salts; and
organics with low molecular weights and high vapor
pressures (volatile). The disadvantages include ex-
pensive equipment, high processing cost and air
pollution potential.
Status/Availability: Commercially available.
Manufacturer: Werner A. Pfleidier, Waldick, New
Jersey
Aerojet Energy Conversion Company, Sacramento,
California
Newport News Industrial Corporation, Newport News,
Virginia
Users:
EPA Contact: Robert Landreth, (513) 569-7836.
Technology:
Blast Furnaces (Iron and
Steel)
Brief Description: Blast furnace temperatures may
reach up to 3400°F, and are generally above 3000°F.
High heat content hazardous wastes can be used to
supplement coke and other fuel requirements for
blast furnace. A blast furnace produces molten iron
from iron ore and other iron bearing feed materials.
Iron ore, carbon (coke) and limestone feed to the top of
the furnace and iron product and slag are removed in
different layers from the bottom. HWF can be injected
just above slag layer.
Applicability/Limitation: Composition (trace ele-
ments) of HWF must be controlled to avoid product
quality problems. Waste oils were fired into blast
furnace in HWERL test programs.
Status/Availability: Less than 80 blast furnaces
currently operating in U.S.
Manufacturer: Several—Must be field constructed.
Users: Cadence Chemicals, Mike Benoit, (219)
879-0371
EPA Contact: Robert Mournighan, (513) 569-7408
-------
Technology: Carbon Adsorption
Brief Description: Removes dissolved organics
from aqueous wastes, and organics from air streams
due to the surface attachment between organic
solutes and the large internal pore surface area of
activated carbon grains. The residuals are spent
carbon and regenerant (steam or solvent).
Applicability/Limitation: Used to treat single-
phase aqueous organic wastes with high molecular
weight and boiling point and low solubility and
polarity, chlorinated hydrocarbons such astetrachlo-
roethylene, and aromatics such as phenol. Limitations
are organic contaminant concentrations <10,000
ppm, suspended solids <50 ppm, dissolved inorganics
and oil and grease <10 ppm.
Status/Availability: EPA Environmental Emergen-
cy Response Unit—two transportable systems (50-
gpm and 600-gpm units).
Manufacturer: Calgon Carbon Corporation, Dave
Jordan, (201)526-4646
Carbon Air Services, Inc., (612) 935-1844
Zimpro, Inc., (715) 359-7211
Chemical Waste Management, John Fink, (714) 940-
7971
Users: IT Corporation, California
EPA Contact: Ron Turner, (513) 569-7775
Richard Traver, (201) 321-6677
Schematic of carbon adsorption.
• To Service
Liquid
Feed
Carbon
Adsorption
Column
#1
Carbon
Adsorption
Column
#2
Spent Carbon * "
(One Unit Changed
Per Time)
•*- To
Regeneration
Toxic Compounds Removed from Water Using the Carbon Adsorption System in the Hazardous Material Spills Treatment Trailer
Compound
DNBP
PCS
Toxaphene
Chlordane
Heptachlor
Aldrin
Dieldrin
Kepone
Pentachlorophenol
Location of Incident
Clarksburgh, New Jersey
Seattle, Washington
The Plains, Virginia
Strongstown, Pennsylvania
Strongstown, Pennsylvania
Strongstown, Pennsylvania
Strongstown, Pennsylvania
Hopewell, Virginia
Haverford, Pennsylvania
Quantity
Treated
(gallons)
2,000,000
600,000
250,000
100,000
3,000
100,000
3,000
100,000
3,000
100,000
3,000
225,000
215,000
Contact
Time
(minutes)
26
30-40
26
17
240
17
240
17
240
17
240
45.5
26
Influent
Concen-
tration
(ppb)
8
400
36
13
1,430
6.1
80
8.5
60.5
11
60.5
4,000
10,000
Effluent
Concen-
tration
(ppb)
<.002
<.075
1
.35
.43
.06
.1
.19
.15
<.01
<.01
<1
<1
Percent
Removal
99.98
99.98*
97.22
97.3
99.99
99.02
99.87
97.76
99.75
99.99*
99.99*
99.98
99.98
-------
Toxic Compounds Removed from Water Using the Carbon Adsorption System in the Hazardous Material Spills Treatment Trailer
(Continued)
Compound
Methylene Chloride
Carbon Tetrachloride
Benzene
Toluene
Xylene
Trichloroethane
Trichloroethylene
Location of Incident
Oswego, New York
Oswego, New York
Oswego, New York
Oswego, New York
Oswego, New York
Oswego, New York
Oswego, New York
Quantity
Treated
(gallons)
250,000
250,000
250,000
250,000
250,000
250,000
250,000
Contact
Time
(minutes)
8.5
8.5
8.5
8.5
8.5
8.5
8.5
Influent Effluent
Concen- Concen-
tration tration
(ppb) (ppb)
190 51
1.1 <1
1 .1
120 .3
140 <1
12 <.1
21 .3
Percent
Removal
73.15
90.91*
90
99.75
99.92*
99.17*
98.57
Source: Becker, D. L, S. C. Wilson, 1978.
Amenability of Typical Organic Compounds to Activated Carbon Adsorption
Compound
Alcohols
Met Hanoi
Ethanol
Propanol
Butanol
n-Amyl alcohol
n-Hexanol
Isopropanol
Ally! alcohol
Isobutanol
t-Butanol
2-Ethyl butanol
2-Ethyl hexanol
Aldehydes
Formaldehyde
Acetaldehyde
Propionaldehyde
Butyraldehyde
Acrolein
Crotonaldehyde
Benzaldehyde
Paraldehyde
Amines
Di-N-Propylamine
Butylamine
Di-N-Butylamine
Allylamine
Ethylenediamine
Diethylenetriamine
Monethanolamine
Diethanolamine
Triethanolamine
Monoisopropanolamine
Diisopropanolamine
Pyridines & Morpholines
Pyridine
2-Methyl-5-ethyl pyridine
IM-Methyl morpholine
N-Ethyl morpholine
Molecular
Weight
32.0
46.1
60.1
74.1
88.2
102.2
60.1
58.1
74.1
74.1
102.2
130.2
30.0
44.1
58.1
72.1
56.1
70.1
106.1
132.2
101.2
73.1
129.3
57.1
60.1
103.2
61.1
105.1
149.1
75.1
133.2
79.1
121.2
101.2
115.2
Aqueous
Solubility
(%)
-
-
-
7.7
1.7
0.58
-
-
8.5
-
0.43
0.07
-
-
22
7.1
20.6
15.5
0.33
10.5
_
-
-
_
-
-
-
95.4
_
-
87
_
si. sol.
-
-
Concentration
mg/l
Initial
(C0)
1,000
1,000
1,000
,000
,000
,000
,000
,010
,000
,000
,000
700
1,000
,000
,000
,000
,000
,000
,000
,000
,000
,000
,000
,000
1,000
1,000
1,012
996
1,000
1,000
1,000
1,000
1,000
1,000
1,000
Final
(C,)
964
901
811
466
282
45
874
789
581
705
145
10
908
881
723
472
694
544
60
261
198
480
130
686
893
706
939
722
670
800
543
527
107
575
467
Adsorbability
% compound/
% carbon
0.007
0.020
0.038
0.107
0.155
0.191
0.025
0.024
0.084
0.059
0.170
0.138
0.018
0.022
0.057
0.106
0.061
0.092
0.188
0.148
0.174
0.103
0.174
0.063
0.021
0.062
0.015
0.057
0.067
0.040
0091
0.095
0.179
0.085
0.107
Percent
Reduction
3.6
10.0
18.9
53.4
71.8
95.5
12.6
21.9
41.9
29.5
85.5
98.5
9.2
11.9
27.7
52.8
30.6
45.6
94.0
73.9
80.2
52.0
87.0
31.4
10.7
29,4
7.2
27.5
33.0
20.0
45.7
47.3
893
42.5
53.3
-------
Amenability of Typical Organic Compounds to Activated Carbon Adsorption (Continued)
Compound
Aromatics
Benzene
Toluene
Ethyl benzene
Phenol
Hydroquinone
Aniline
Styrene
Nitrobenzene
Esters
Methyl acetate
Ethyl acetate
Propylacetate
Butyl acetate
Primary amyl acetate
Isopropyl acetate
Isobutyl acetate
Vinyl acetate
Ethylene glycol monoethyl ether
acetate
Ethyl acrylate
Butyl acrylate
Ethers
Isopropyl ether
Butyl ether
Dichloroisopropylene ether
Glycols & Glycol Ethers
Ethylene glycol
Diethylene glycol
Tnethylene glycol
Tetraethylene glycol
Propylene glycol
Dipropylene glycol
Hexylene glycol
Ethylene glycol monomethyl ether
Ethylene glycol monoethyl ether
Ethylene glycol monobutyl ether
Ethylene glycol monohexyl ether
Diethylene glycol monoethyl ether
Diethylene glycol monobutyl ether
Ethoxytriglycol
Halogenated
Ethylene dichlonde
Propylene bichloride
Ketones
Acetone
Methylethyl ketone
Methyl propyl ketone
Methyl butyl ketone
Methyl isobutyl ketone
Methyl isoamyl ketone
Dnsobutyl ketone
Cyclohexanone
Acetophenone
Isophorone
Organic Acids
Formic acid
Acetic acid
Propionic acid
Butyric acid
Valeric acid
Caproic acid
Acrylic acid
Benzoic acid
Oxides
Propylene oxide
Styrene oxide
Molecular
Weight
78.1
92 1
106.2
94
110.1
93.1
104.2
123.1
74.1
88.1
102.1
116.2
130.2
102.1
116.2
86.1
132.2
100.1
128.2
102.2
130.2
171.1
62 1
106.1
150.2
194.2
76.1
134.2
1182
76.1
90.1
118.2
146.2
134.2
162 2
178.2
990
113.0
58.1
72.1
86.1
100.2
1002
114.2
142.2
98.2
120.1
1382
46.0
60.1
74.1
88.1
102 1
1162
72.1
12.1
58.1
120.2
Aqueous
Solubility
(%)
0.07
0047
0.02
6.7
6.0
3.4
003
0.19
31.9
8.7
2
068
0.2
2.9
063
2.8
229
2.0
02
1 2
0.03
0.17
-
-
-
-
-
-
-
-
-
-
0.99
-
-
-
0.81
0.30
-
26.8
4.3
v. si sol.
1 9
0.54
0.05
2.5
0.55
1.2
-
-
-
-
2.4
1.1
-
029
40.5
0.3
Concentration
mg/l
Initial
(Co)
416
317
115
1,000
1,000
1,000
180
1,023
1,030
1,000
1,000
1,000
985
1,000
1,000
1,000
1,000
1,015
1,000
1,023
197
1,008
1,000
1,000
1,000
1,000
1,000
1,000
1,000
1,024
1,022
1,000
975
1,010
1,000
1,000
1,000
1,000
1,000
1,000
1,000
988
1,000
986
300
1,000
1,000
1,000
1,000
1,000
1,000
1,000
1,000
1,000
1,000
1,000
1,000
1,000
Final
(Ct)
21
66
18
194
167
251
18
44
760
495
248
154
119
319
180
357
342
226
43
203
nil
nil
932
738
477
419
884
835
386
886
705
441
126
570
173
303
189
71
782
532
305
191
152
146
nil
332
28
34
765
760
674
405
203
30
355
89
739
47
Adsorbability
% compound/
% carbon
0.080
0.050
0019
0.161
0 167
0.150
0028
0.196
0.054
0.100
0.149
0.169
0175
0.137
0.164
0.129
0132
0.157
0 193
0.162
0.039
0.200
0.0136
0.053
0.105
0.116
0.024
0033
0.122
0.028
0063
0 112
0 170
0.087
0.166
0 139
0 163
0.183
0043
0094
0.139
0.159
0 169
0 169
0.060
0134
0.194
0 193
0.047
0.048
0065
0.119
0.159
0.194
0.129
0 183
0052
0190
Percent
Reduction
95.0
79.2
843
80.6
833
74.9
888
95.6
26.2
50.5
75.2
84.6
88.0
68.1
82.0
643
65.8
~nn
95.9
80.0
100.0
1000
6.8
262
52.3
58.1
11.6
165
61.4
13.5
31.0
55.9
871
43.6
82.7
69 7
81.1
929
21.8
46.8
69.5
80.7
84.8
852
1000
66.8
97.2
96.6
23.5
24.0
32 6
59.5
79.7
97.0
64.5
91.1
26.1
95.3
10
-------
Technology: Catalytic
Dehydrochlorination
Brief Description: Catalytic dehydrochlorination is
based on the reaction of polychlorinated hydrocarbons
with high-pressure hydrogen gas in the presence of a
catalyst. The feed must be in either liquid or gaseous
form with the inorganic and inert constituents
removed. The choice of catalyst depends on the
process requirements. The operating temperatures
are 671 ° to 707°F under 30to 50atms pressure. The
quantity of catalyst (usually 61 percent Ni on Kiesel-
guher or 10 percent palladium in C for PCB com-
pounds) is about 0.2 percent of pollutant weight.
Applicability/Limitation: In general, supported
catalysts are quickly deactivated by impurities such
as tars, sulfur compounds, etc. These processes are
excessively costly and often require the use of
hazardous chemicals.
Status/Availability: Laboratory scale.
Manufacturer: :_
Users:
EPA Contact: Charles Rogers, (513) 569-7757
Technology: Centrifugation
Brief Description: Centrifugation is a physical
separation process in which the components of a fluid
mixture are separated mechanically, based on their
density, by rapidly rotating the mass of fluid within a
rigid vessel. Centripetal forces in Centrifugation are
similar to gravitational forces in sedimentation except
that centripetal forces are thousands of times stronger
than gravitational forces, depending on diameter and
rotational speed of the centrifuge.
Applicability/Limitation: Dewatering, separating
oil and water, clarification of viscous gums and
resins, and recovery of metals. Centrifuges are gener-
ally better suited than vacuum filters for dewatering
sticky or gelatinous sludges. Disc-type centrifuges
can be used to separate a three-component mixture
(i.e., oil, water, solids). Centrifuges cannot generally
be used for clarification since they may fail to remove
solids which are not large or dense particles. Recovery
and removal efficiencies may be improved if filter
paper or cloth are incorporated in the centrifuges.
Status/Availability: Commercially available.
Western States Machine
Manufacturer:
Bird, Fletcher
Sharpies
Dorr-Oliver
Users: Widespread
EPA Contact: S. Garry Howell, (513) 569-7756
Basket centrifuge.
Feed
I) y Basket Wall
solids-
rake
/r
,£
t
|
~T^
a
6
4
t
t
4
V—
Revolving /
Basket Frame
\
tt
T^
*T-
/ \
_^^ /
1&
fT:
^
/
1
- — ~ — - — .
™
t
t
«
f
*>
X
;
f
4,
i
V-
(Used with
Perforated Wall)
- Solids
Cake Buildup
1
i Effluent
_1
Solid bowl centrifuge.
Drive Assembly
Rotor Drive Assembly
Feed
Solids
Discharge
Clarified
Effluent
11
-------
Technology: Chemical Precipitation
Brief Description: Chemical precipitation facilities
remove dissolved metals from aqueous wastes by
chemically converting the metals into insoluble form.
Metals may be precipitated from solution as hydrox-
ides, sulfides, carbonates or other salts. Hydroxide
precipitation with lime is most common; however,
sodium sulfide is sometimes used to achieve lower
effluent metal concentrations. This involves pH
adjustment followed by sodium sulfide and flocculant
aid additions. Solids separation is effected by standard
flocculation coagulation techniques. The resulting
residuals are metal sludge and the treated effluent
with an elevated pH and, in the case of sulfide
precipitation, excess sulfide.
Applicability/Limitation: This technology is used
to treat aqueous wastes containing metals including:
zinc, arsenic, copper, manganese, mercury, cadmium,
trivalent chromium, lead and nickel. Selective precip-
itation of barium as barium sulfate and silver as silver
chloride are other applications. Limitations include
optimum pH for the mix of metals present and
chelating or complexing agents. Organics are not
removed. The resulting sludge may be hazardous by
definition but often may be delisted by specific
petition. Sulfide precipitation has been successfully
used at a plating facility (as shown in the following
table).
Status/Availability: Commercially available.
Manufacturer: Mobile Systems—Rexnord CRIG,
Richard Ostawski, (414) 643-2762
Ecolochem, Inc., Richard Smallwood, (800)446-8004
Dravo Corporation, Ogden demons, (412) 777-5235
Users: Widespread
EPA Contact: S. Garry Howell, (513) 569-7756
Solubilities of metal hydroxides as a function of pH.
100
8 9 10
Solution pH
11
12
-------
Treatment of Industrial Plating Wastewaters by Sulfide Precipitation and Settling
Initial conditions of wastewater
pH = 7.1 ±0.1
Zn = 82.7 mg/l = 1.264mM
Ni = 4.7 mg/l = 0.080 mM
Total Metals = 1.344 mM
Run
No.
35
36
37
38
39
40
41
42
43
44
Residual Metal,
mg/l
PH
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
7.2
7.4
t, min
10.0
10.0
15.0
15.0
5.0
5.0
10.0
10.0
10.0
10.0
S* Dosage
1.1 5x
0
1.1 5x
0
1.1 5x
0
I.Ox
0.8x
0.8x
1.1 5x
Zn
5.0
3.4
4.4
>5.0
0.76
3.6
4.7
>5.0
>5.0
>5.0
Ni
0.04
0.05
0.11
0.08
0.15
0.09
0.10
0.20
1.05
>5.0
Removal Efficiency, %
Zn
<93.95
95.89
94.68
<93.95
99.08
95.65
94.32
<93.95
<93.95
<93.95
Ni
99.15
98.94
97.66
98.30
96.81
98.09
97.87
95.74
77.66
0
Overall
<94.34
96.15
94.94
<94.29
99.03
95.87
94.61
<94.41
93.06
88.44
Ref: Peters, 1984.
Chemical precipitation and associated process steps.
Chemical
Precipitants
Chemical
Flocculants/
Settling Aids
Liquid
Feed
Flocculation Flocculating
Well Paddles
Baffle
Precipitator
Tank
Effluent
Flocculator-
Clarifier
Sludge
13
-------
Technology: Circulating Bed Combustor
Brief Description: The GA circulating bed com-
bustor is designed to be an improvement over
conventional fluidized beds. The system operates at
higher velocities and with finer sorbents than fluidized
bed systems. This permits a unit that is more compact
and easier to feed. The unit also produces lower
emissions and uses less sorbent materials than the
fluidized bed systems. No off-gas scrubber is neces-
sary in the circulating bed combustor and heat can be
recovered as an added benefit.
The key to the high efficiency of the circulating bed
combustor is the high turbulence that is achieved
within the combustor. This feature allows efficient
destruction of all types of halogenated hydrocarbons,
including BCBs and other aromatics, at relatively low
temperatures (less than 850°C). All acid gases are
captured within the combustion chamber by injected
limestone. Compounds containing high levels of
phosphorus, sulfur, cyanide, etc., can be processed
with emissions of NO,, CO and acid gases. In addition
to the turbulence a large combustion zone with
uniform (and lower) temperature throughout also
contributes to high efficiency. The circulating bed
combustor also features longer residence times of the
combustibles and sorbents in the combustion zone.
Applicability/Limitation: The system is capable of
treating solids, sludges, slurries and liquids contain-
ing such compounds as chlorobenzenes, acetonitrile,
carbon tetrachloride, trichloroethane, sodium fluo-
ride, tributyl phosphate, aniline, malathion, sodium
silicates and lead oxide.
The system is capable of handling feeds of liquids,
sludges or solids. The process requires no atomizer or
multiple feed ports for successful treatment. The high
degree of turbulence and mixing ensures treatment
of a wide variety of wastes. The wastes however must
be homogenous in composition when fed to the
combustor.
An additional benefit of the circulating bed incin-
erator is the possibility of heat recovery. Energy can
be recovered either as steam or hot water. The system
takes advantage of good heat transfer in the com-
bustor rather than utilizing a separate waste heat
boiler for heat recovery. This is possible because the
combustion chamber is of "water wall" construction,
therefore, cooling tubes need not be located in the
direct path of hot gases.
Status/Availability: Ready for field-scale testing.
Manufacturer: G. A. Technologies
Users:
EPA Contact: Donald Oberacker, (513) 569-7341
14
-------
Technology: Distillation
Brief Description: Separates miscible organic liquids
for solvent reclamation and waste volume reduction.
The resulting residuals are still bottoms and "slop" or
intermediate distillate cuts. Two major types of
distillation processes are batch distillation and con-
tinuous fractional distillation.
Applicability/Limitation: Used to treat liquid organic
wastes, primarily spent solvents, either halogenated
such as, spent 1,1,1-trichloroethane degreasing
solvent or non-halogenated compound such as
methyl ethyl ketone solvent mixture from paint line
clean-out. Liquids to be separated must have different
volatilities. The limitations are heat-sensitive sus-
pended solids and azeotropes. Batch distillation in a
heated still pot with condensation of the overhead
vapors is easily controlled and flexible, but cannot
achieve the high product purity of continuous frac-
tional distillation. Small packaged batch stills treating
one drum per day or less are becoming popular for
on-site recovery of solvents. Continuous fractional
distillation is accomplished in tray columns or packed
towers ranging up to 40 feet in diameter and 200 feet
high. Each is equipped with a reboiler, a condenser,
and an accumulator. The capacity of a unit is a
function of the waste being processed, purity re-
quirements, reflux ratio and heat input.
Status /A vailability:
Manufacturer: Exceltech, Inc., John Sedwick, (415)
659-0404
Kipin Industries, Peter Kipin, (41 2) 495-6200
Mobile Solvent Reclaimers, Inc., Larry Lambing, (816)
271-4392
Users: —
EPA Contact: Ron Turner, (513) 569-7775
Batch distillation.
Continuous fractional distillation.
Feed-»J
Batch
Still
Condenser
Partial Recycle
Accumulator
Distillate
Steam
• Condensate
Distillation
Column
Volatile
Liquids
Perforated Tray Type
Distillation Plate
Bottom
Product
Accumulator
Distillate
r c^~\—"— Steam
Reboiler \J1/' • • Condensate
Still Bottoms
(Residue)
15
-------
Technology: Electric Reactors
Brief Description: Use an electrically heated fluid
wall reactor to pyrolyze waste contaminants from
particles such as soils. Emissions and residuals
include mostly Na, H20 and CI2 and/or HCI trapped in
the scrubber ash components in the residue. The
advantages are that it is transportable, has a high
treatment efficiency, and emissions are low.
Applicability/Limitation: Used to treat organics,
inorganics in solid, liquid or gas (solid or liquid may
require pretreatment) and for PCB or dioxin contam-
inated soils. It is limited to treating solids less than
-35 U.S. mesh and liquids atomized to <1 500 micron
droplets.
Status/Availability: Commercial units are under
construction, none in use.
Manufacturer: Thagard Research Corporation,
Costa Mesa, California
J. M. Huber Construction, Jim Boyd (806) 274-5040
Users: Two units in Borger, Texas.
EPA Contact: Harry Freeman, (513) 569-7529
Technology: Electrolytic Oxidation
Brief Description: In this process cathodes and
anodes are immmersed in a tank containing a waste
to be oxidized, and a direct electrical current is
imposed on the system. The process is particularly
applicable to cyanide bearing waste. The products of
decomposition for cyanide waste are ammonia, urea,
and carbon dioxide. During the decomposition, metals
present are plated out on a cathode.
Applicability/Limitation: Used to treat high con-
centrations (up to 10 percent) of cyanide and to
separate metals and allow their potential recovery.
Limitations include physical form (such as sludge or
solids), non-selective competition with other species
and long process time at up to 200°F.
Status/Availability: Commercially available.
Manufacturer: Stauffer Chemical Company
Users:
EPA Contact: S. Garry Howell, (513) 569-7756
Technology: Evaporation
Brief Description: Evaporation is the physical
separation of a liquid from a dissolved or suspended
solid by the application of energy to volatilize the
liquid. In hazardous waste treatment, evaporation
may be used to concentrate a hazardous material
thus reducing the volume of waste requiring subse-
quent treatment or disposal.
Applicability/Limitation: Evaporation can be ap-
plied to any mixture of liquids and non-volatile solids
provided the liquid is volatile enough to evaporate
under reasonable heating or vacuum conditions.
(Both the liquid and the solid should be stable under
those conditions.) If the liquid is water, evaporation
can be carried out in a large pond with solar providing
the energy. Evaporation of aqueous wastes can also
be done in closed process vessels with energy
provided by steam and the resulting water vapor
condensed for possible reuse. Energy requirements
are usually minimized by such techniques as vapor
recompression or multiple-effect evaporators.
Evaporation is applied to solvent wastes comtami-
nated with nonvolatile impurities such as oil, grease,
paint solids, or polymeric resins. Mechanically agi-
tated or wiped thin film evaporators are used. Solvent
is evaporated and recovered for reuse. The residue is
the bottom stream, typically containing 30 to 50
percent solids.
Status/Availability: Commercially available.
Manufacturer:
(Mobile Brine
Washington
Resources Convervation Company,
Concentration Systems), Bellevue,
Users:
EPA Contact: Ron Turner, (513) 569-7775
16
-------
Schematic of single and multiple effect evaporators.
Exhaust
Vacuum
Pump
Condensate
Distilled Vapor
— 1
" Cooling
] water
Heat
Exchanger
• Steam
Steam Condensate
Vapor
Chamber
Dilute Liquid
o—
Feed
Pump
Concentrated Liquid
Transfer
Pump
Typical Single Effect Evaporator—Falling Film Type
Exhaust |
|"~\ Uaa»
Vacuum 1 )
Pump ^r
T 1 f
Condenser Cooling
| Water
Excr
(T
r*1
1 /3rd s
f Effect
Condensate VaP°r 1 ^"
Chamber j, f
(TVP) f 1st]
Stage
V /
Condensate
Dilute Liauid
U
Feed
_J
Pump
an
yp
/-*^
S
ger
Distilled
Vapor f^— f ^
-. ,
J
r
*s
/2nd N
Effect
^
r
2nd
Stage
\ /
X_
P
~~~^mm^
S
Distilled
Vapor r*^"^
•" 1
—
\
_J
7^
s
/1st\
Effect
•* Steam
1 Steam
^\S Condensate
<
3rd I
Stage
\ /
V.
^r
Concentrate
f *> •*
l— (1 Liquid (Typ.)
Transfer
Pump
(Typ
Typical Multi-Effect (Triple Effect) Evaporator—Falling Film Type
17
-------
Technology: Extraction/Soil Flushing or
Washing
Brief Description: Removes toxic/hazardous or- Users: Volk Air National Guard Base, Wisconsin
ganics and inorganics from soil or sludge by extracting (found not viable)
contaminants by partitioning. The site is flooded with Lee's Farm, Wisconsin, (31 2) 535-2318
the appropriate flushing solution and the elutriate is Celtor Chemical Works
collected. The resulting waste-containing elutriate is Hoopa Indian Reservation, Nick Morgan, (916) 243-
treated. 5831
Applicability/Limitation: Used to remove both EPA Contact: Ron Turner, (513) 569-7775
organics and inorganics if they are sufficiently soluble Richard P. Traver, ( .02)321-6677
in a solvent. Surfactants can be used for hydrophobic
organics.
Status/'Availability: Commercially available.
EPA Mobile In-Situ/Containment Treatment Unit
Manufacturer: Critical Fluid Systems, Peter Dunlap,
(617)492-1631
IT Corporation, Dave Sikes, (41 5) 228-5100
18
-------
Technology: Filtration
Brief Description: Granular media filtration usually
uses gravity to remove solids from a fluid by passage
of the fluid through a bed of granular material.
Several mechanisms are involved in the removal of
suspended solids by granular media filtration. They
include straining, physical adsorption and coagula-
tion-flocculation. In vacuum and high-pressure filtra-
tion pressure (either negative or positive) is used to
move water through the filter media and leaving the
solids behind. These filters may be precoated with a
filter aid such as a ground cellulose, diatomaceous
earth, etc.
Applicability/Limitation: Filtration is used for the
dewatering of sludges and slurries as a pretreatment
for other processes. Filtration does not reduce the
toxicity of the waste. Although sometimes powdered
activated carbon may be used as a combination
adsorbent and filter aid, it merely reduces the volume
of waste to be treated. Filtration should not be used
with sticky or gelatinous sludges, this is due to
likelihood of filter media plugging. Granular media
should be preceded by gravity separation if suspended
solids are greater than 100 mg/l. Design criteria—In
granular bed filtration rates range from 2 gpm/sf for
shallow beds of fine sand to over 15 gpm/sf for deep
bed filters using coarse sand or multiple media beds.
Vessels are from 21/a to 20 feet in diameter, with
media depth of 11/2 to over 15 feet.
Status/Availability: Commercially available.
Granular Media Filters
Corporation, Dave Jordan,
(201]
Manufacturer:
Calgon Carbon
526-4646
Carbon Air Services, Inc., (612) 935-1844
Chemical Waste Management, John Fink, (714) 940-
7971
Packaged granular media gravity filter.
Wash Trough
\ |— Adjustable Weir
Influent
Piping
Backwash
Inlet
Note:
Arrows Indicate Route
of Backwash
Backwash
Effluent
Underdrain System
Dorr-Oliver
Krauss-Maffei, (316) 945-5251
Komline Sanderson, (201) 234-1000
Bird Machine Co., (617) 668-0400
DR Sperry, Inc., (312) 892-4361
Users: Widely used.
EPA Contact: S. Garry Howell, (513) 569-7756
Vacuum filter.
Rotary
Drum
Filter press unit.
Gasket
Slurry
Inlet
Filtrate
Outlet
19
-------
Technology: Fluidized Bed Incinerators
Brief Description: Utilize a very turbulent bed of
inert granular material (usually sand) to improve the
transfer of heat to the waste streams to be inciner-
ated. Residues and emissions include acid gases
trapped in the bed, low particulates, low nitrogen
oxides and ash components (for low-ash wastes).
Advantages of this technology include low tempera-
ture with no ash agglomeration, low gas emissions,
low particulate emissions and a long residence time.
Operating temperatures range from 1300 to 2100°F,
gas residence times are usually several seconds, and
excess air rates are normally 40 percent. Heat release
rates range from 100,000 to 200,000 Btu/hr/ft3.
Applicability/Limitation: Not presently used for
hazardous waste commercially. Refractory wastes
may not be destroyed.
Status/Availability: Commercially available.
Manufacturer: Battelle, Jack Conner, Columbus,
Ohio
GA Technologies, William Rickman, (619) 455-3860
Dorr-Oliver
Waste-Tech Services, Inc., (208) 522-0850
(303) 987-1790 (mobile)
Users:
EPA Contact: Harry M. Freeman, (513) 569-7529
Energy Resources Company's pilot-plant FBC facility.
Freeboard Upper Temperature
Analysis f
Freeboard Cooling Tubes J
^ Fly Ash
In-Bed Cooling Tubes
Fluidized-Bed Temperature
Freeboard Lower Temperature ..
Feed Hopper
Rotary Valve
Preheat Burner
•Air
Fluidizing-Air Blower
20
-------
Technology:
Fly Ash or Lime-Based
Pozzolan Stabilization/
Solidification
Brief Description: This technology involves the
addition of large amounts of a siliceous material
combined with a setting agent such as lime, cement
or gypsum resulting in dewatering, stabilized, solidi-
fied product. Also can use thermoplastic (asphalt,
polyethylene).
Applicability/Limitation: Used for sludges and
contaminated soils including metals, waste oils and
solvents. Materials such as borates, sulfates and
carbohydrates interfere with the process. Long-term
stability and resistance to leaching unknown in some
cases.
Status/Availability: Commercially available.
Manufacturer: Different silicate processes avail-
able.
Users:
EPA Contact: Carlton Wiles, (513) 569-7795
Technology: Fuel Blending
Brief Description: Method to reuse waste organics
as fuel substitutes. The objective is the controlled
blending of segregated wastes of known character-
istics into a fuel product whose chemical and physical
characteristics meet the fuel specifications of the fuel
user.
Applicability/Limitation: Used to combine waste
oils, solvents and organic sludges to produce a
material with a fuel value usually greater than 10,000
Btu/lb. Limitations include chlorine and water con-
tent, the waste viscosity and the need for low solids.
In addition, the presence of certain hazardous con-
stituents (such as PCBs) and the corrosivity of the
waste can be limiting criteria for certain wastes.
Status /Availability: In use for lime and cement
manufacturing, process heating and blast furnace
operation where permitted.
Manufacturer:
Users: Solid Tek Systems, Inc., (404) 361 -6181
EPA Contact: Ron Turner, (51 3) 569-7775
Technology: Granular Media Filtration
Brief Description: Granular media filtration uses
gravity to remove solids from a fluid by passage of the
fluid through a bed of granular material. Several
mechanisms are involved in the removal of suspended
solids by granular media filtration. They include
straining, physical adsorption and coagulation-floc-
culation. A granular media filter therefore can remove
particles much smaller than the void size of the filter
media. Filters may be open top with gravity feed, or
enclosed in a pressurized vessel. The range of
configurations available include many proprietary
designs related primarily to improvements in the
backwashing operation.
Applicability/Limitation: Granular media filtration
is typically used after gravity separation processes for
additional removal of suspended solids and oils prior
to the other treatment processes and as a polishing
step for treated wastes to reduce suspended solids
and associated contaminants to low levels. Pretreat-
ment by filtration is appropriate for membrane
separation processes, ion exchange, and carbon
adsorption in order to prevent plugging or overloading
of these processes. Filtration of settled waste is often
required to remove undissolved heavy metals which
are present as suspended solids to ensure meeting
effluent quality requirements. Granular media filtra-
tion should be preceded by pretreatment processes if
the suspended solid concentration exceeds about
100 mg/l. Otherwise, premature plugging will occur.
Status/Availability: Commercially available.
Manufacturer: Calgon Carbon Corporation, Dave
Jordan, (201)526-4646
Carbon Air Services, Inc., (612) 935-1844
Chemical Waste Management, John Fink, (714) 940-
7971
Users:
EPA Contact: S. Garry Howell, (51 3) 569-7756
21
-------
Technology: Hydrolysis
Brief Description: Enhances cleavage rates of
organic molecules (breakdown to simpler, less-toxic
compounds) by acceleration of acid or base-catalyzed
hydrolysis rates through adjustment of soil/ground-
water/sludge pH.
Applicability/Limitation: Applicable in-situ treat-
ment, e.g., pesticide spills. Acid hydrolysis not
recommended for in-situ treatment because of poten-
tial mobilization of heavy metals. Base-catalyzed
hydrolysis attractive because of pH adjustment by
lime, alkaline fly ash, or sodium carbonate.
Status/Availability: Used at several sites.
Manufacturer: Not applicable.
Users:
EPA Contact: Donald Sanning, (513) 569-7875
Technology: Industrial Boilers
Brief Description: Hazardous waste is used as
supplementary fuel to coal, oil or natural gas in fire
tube and water tube industrial boilers. Hazardous
waste fuel (HWF) (generally limited to liquid wastes)
can be blended with primary fuel and fired into a
boiler with primary fuel or it can be fired alone
through other burners. The heat release rate of
boilers that have been tested with HWF ranges from
100 to 800 x 103 Btu/ftVhr.
Applicability/Limitation: Chlorine and sulfur must
be limited to HWF to minimize corrosion of boiler
materials of construction and to avoid increases in
HCI and sulfur oxide air emissions. Solids hazardous
wastes such as contaminated soils are not applicable
for use as HWF in boilers. Particularly useful for the
disposal of hazardous wastes generated on site.
Status/Availability: Only a small fraction of the
nations 23,000fossil fueled boilers are in use burning
HWF.
Manufacturer: Various manufacturers. May be
package units or field constructed.
Users: Hazardous waste generators may use on-
site boilers to destroy combustible wastes.
EPA Contact: Robert E. Mournighan, (513) 569-
7408
Technology:
Industrial Kilns (Cement,
Lime, Aggregate, Clay)
Brief Description: Rotary kilns constructed of steel
casings lined with refractory brick. Blended feed
material is fed into the upper (higher) end of the kiln
and fuel (coal, gas, oil, or hazardous waste) is fired at
the lower end. Kiln temperatures are about 3000°F
for lime kilns, and less than 2000°F for aggregate and
clay drying kilns. Hazardous waste fuel usually fired
into kiln with separate burner than primary fuel.
Waste blending may be necessary to obtain desired
fuel characteristics.
Applicability/Limitation: Generally limited to liq-
uid waste. Chlorine and sulfur content of waste fuel
must be controlled to prevent kiln operating and
product quality problems. Contaminated soils are not
good candidates for treatment in industrial kilns.
Status/Availability: 280 cement and lime kilns but
use of hazardous waste fuel not widespread. At least
11 cement kilns now burn HWF as supplemental fuel.
Manufacturer: Various manufacturers. Kilns are
field constructed.
Users: Off-site HWF generators.
EPA Contact: Robert Mournighan, (513) 569-7408
22
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Technology:
Infrared Incineration
Systems
Brief Description: The primary chamber consists of
a rectangular cross section "box" of carbon steel
lined with layers of lightweight ceramic fiber blanket.
Infrared energy is provided by silicon carbide resis-
tance heating elements. The material to be processed
is conveyed through the furnace on a woven wire belt
through the furnace. When the material reaches the
discharge end of the furnace, it drops off of the belt
into a hopper. The residuals are the gaseous products
of waste combustion, low particulates and solid
residuals. The advantages include a quiescent com-
bustion zone for low paniculate emissions, reduced
gaseous emissions since no fossil fuel is used, up to
50 percent turndown, the system allows a high
degree of control and long residence times are
achievable.
Applicability/Limitation: Used to treat solids,
sludges and contaminated soils. The process is used
primarily for solids or sludges, but liquid or gaseous
injection systems are available.
Status/Availability: Operational units at several
locations, mobile units under construction, pilot-test
unit available.
Manufacturer: Shirco Infrared Systems, Jim Welsh,
(214)630-7511
EPA Contact: Harry M. Freeman, (513) 569-7529
Technology:
In-Situ Adsorption
(PermeableTreatment Beds)
Brief Description: A trench, excavated down to a
confining layer, is filled with adsorbent or chemical
treatment material, such as activated carbon, diato-
maceous earth, fly ash, zeolites, lime or sodium
carbonate(to raise pH). Contaminatedgroundwater is
treated as it percolates through the beds.
Applicability/Limitation: Beds must be sufficiently
permeable to allow passage of ground water. Bed
pores may clog up, beds require renovation or
replacement.
Status/Availability: Not used in full scale yet.
Manufacturer:
Users:
EPA Contact: Donald Sanning, (51 3) 569-7875
Technology:
In-Situ Chemical
Immobilization
Brief Description: Heavy metals are stabilized in
the ground as insoluble precipitates (sulfides, phos-
phates, hydroxides, carbonates) or oxidized forms
(e.g., ferric hydroxide with Mn coprecipitate). Alter-
natively some reduced forms are more stable (Cr[lll],
Se[IV]). Certain organic monomers can be stabilized
as polymers.
Applicability/Limitation: Applies mostly to heavy
metals. The in-situ conditions must be maintained to
avoid reversion of the stabilized form to a more mobile
form (e.g., sulfides can be oxidized to sulfates,
remobilizing the heavy metals).
Status/Availability: EPA Mobile In-Situ/Contain-
ment Treatment Unit.
Manufacturer: Not applicable.
Users:
EPA Contact: Donald Sanning, (51 3) 569-7875
Richard Traver, (201) 321-6677
23
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Technology: In-SituThermal Destruction
Brief Description: Radio-frequency (RF) electrodes
placed along the ground surface heat the shallow
subsurface and generate superheated steam from
ground water. Organics are destroyed or mobilized by
vaporization, thermal decomposition, or distillation.
Applicability/Limitation: High operating costs
(electric power). Probably most applicable to volatile,
low boiling point, or easily decomposed organic
compounds.
Status/Availability: Not used on full scale yet.
Manufacturer: Illinois Institute of Technology has
done research.
Users:
EPA Contact: Donald Sanning, (513) 569-7875
Technology: Ion Exchange
Brief Description: Removes toxic metal ions from
solution to recover concentrated metal solutions for
recycling by exchanging one ion, electrostatically
attached to a solid resin material for a dissolved toxic
ion. The resulting residuals include spent resins and
spent regenerants such as acid, caustic or brine.
Applicability/Limitation: This technology is used
to treat metal wastes including cations (Ni2+, Cd2+,
Hg2+) and anions (Cr042~, Se04 , HAsO*2'). Limita-
tions are selectively/competition, pH, and suspended
solids. The oxidizing agent concentration should be
greater than 50 meq/l for practical operation. Highly
concentrated waste streams (>2500 mg/l contam-
inants) or high solid concentrations (>50 mg/l)
should be avoided.
Status/Availability: Commercially available.
Manufacturer: See buyer's guides from trade
journals.
Users: Used on full commercial scale for water
treatment/conditioners.
EPA Contact: S. Garry Howell, (513) 569-7756.
Schematic of ion exchange.
To Storage Tank or
Other Treatment System
To Storage Tank or
Other Treatment System
Influent
Backflush
Water
Acid
"Regenerant
Cation Exchange
System
Backflush
Water
Treated
Wastewater
— Caustic
Regenerant
Anion Exchange
System
To Storage Tank or
Other Treatment System
To Storage Tank or
Other Treatment System
24
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Technology: Liquid Injection Incineration
Brief Description: Waste material is introduced to
the combustion chamber in various droplet sizes to
mix with air and fuel, as needed. Following combus-
tion, the resulting gases are cooled and treated to
remove particulates and to neutralize acid gases.
Pretreatment such as blending, may be required for
wastes to provide efficient mixing with the oxygen
source. Operating temperatures range from 1200° to
1300°F and the gas residence time ranges from 0.1 to
2.0 seconds. Typical heat output ranges from 1 to 100
MMBtu/hr.
Applicability/Limitation: Can be applied to all
pumpable organic wastes including wastes with high
moisture content. Care must be taken in matching
waste to specific nozzle designs. Wastes with high
moisture content, high inorganic content or which
contain heavy metals are restricted.
Status/Availability: Ensco has a mobile unit avail-
able, used with rotary kilns. EPA Mobile Unit/
Incineration System is available.
Manufacturer:
trade journals.
Several, see buyer's guide from
Users: EPA Region VII, James Denny Farm,
Missouri (dioxin destruction).
EPA Contact: Donald Oberacker, (513) 569-7431
Frank J. Freestone, (201) 321-6632
Technology: Macroencapsulation/
Overpacking
Brief Description: Encapsulates large particles in
an environmentally secure barrier using lime or
cement pozzolan, thermoplastic or organic polymer. A
matrix is formed from reactive components, but the
waste not uniformly dispersed. The product contain-
ing the waste is in nodule form. Product placement
technique is very important.
Applicability/Limitation: Some processes are ap-
plicable to both organics and inorganics. Advantages—
The waste nodules are isolated, improved handling,
low permeability, minimum treatment, good beaming
strength. Disadvantages—Presence of free liquid and
the resultant product can be teachable.
Status /A vailability:
Manufacturer:
Users:
EPA Contact: Robert Landreth, (513) 569-7839
Technology: Molten Glass
Brief Description: Uses a pool of molten glass as
the heat transfer mechanism to destroy organics and
to capture ash and inorganics. The emissions include
acid gas and particulates and all residue is contained
in the glass. The advantages include significant
volume reduction, most wastes are treatable, the
residual is stabilized glass. Process is based on
existing glassmaking technology.
Applicability/Limitation: Used to treat a ny sol id or
liquid such as plastics, asphalt, PCB or pesticides.
Sodium sulfates greater than 1 percent of the final
glass may pose a problem. It is inappropriate for soils
or high ash waste and it requires additional treatment
for off-gas.
Status/Availability: Commercially available for
uses other than hazardous waste incinerators.
Manufacturer: Penberthy Electromelt International,
Inc., (206) 762-4244
Battelle—Northwest, (509) 375-2927
Users:
EPA Contact: Harry M. Freeman, (513) 569-7529
25
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Technology: Molten Salt
Brief Description: Waste material is injected be-
neath a bed of molten sodium carbonate for incinera-
tion. Inorganics trapped in the salt include phos-
phorus, sulfur, arsenic and halogens. The salt acts as
a gas scrubber so there are low concentrations or no
acid gas emissions, the scrubber controls particulates
and the salt/ash mixture makes up the solid residue.
Reaction temperatures in the bed range from 1500to
2000°F and residence times are typically 0.75
seconds.
Applicability/Limitation: Used to treat low ash,
low water content solid or liquid wastes. Limitations
are that low ash, and low water content are required
and molten salt can be corrosive. The neutralization
of acid gases results in the formation of other salts
that can change the fluidity of the bed and hence,
require frequent replacement of bed material.
Status/Availability: Pilot-scale units available.
Manufacturer: Rockwell International, (213) 700-
8200
Users:
EPA Contact: Harry M. Freeman, (513) 569-7529
Technology: Multiple Hearth Incinerator
Brief Description: Sludge or granulated solid com-
bustible waste feeds through the furnace roof where
a rotating air-cooled central shaft with air-cooled
rabble arms and teeth plows the waste across the top
hearth to dropholes where it falls to the next
successive hearth until the ash is discharged at the
bottom.
Applicability/Limitation: Disposes of sludges, tars,
solids, gases and liquid combustible wastes (through
nozzles). Not recommended for hazardous wastes.
Status/Availability: Commercially available.
Manufacturer: See buyer's guide for trade journals.
Users: Most widely used sewage sludge incinera-
tion method.
EPA Contact: Donald Oberacker, (513) 569-7431
Technology: Neutralization
Brief Description: Renders acid or caustic wastes
non-corrosive by pH adjustment. The resulting resid-
uals include insoluble salts, metal hydroxide sludge,
and neutral effluent containing dissolved salts. The
final desired pH is usually between 6.0 and 9.0.
Applicability/Limitation: Used to treat corrosive
wastes, both acids and bases. Limitations may include
concentration, the physical form such as sludges or
solids and the need for corrosion-resistant equip-
ment.
Status/Availability: Commercially available.
Manufacturer: Newpark Waste Treatment Sys-
tems, Inc., James Hobby, (419) 586-6683
Solid Tek Systems, Inc., (404) 361-6181
Ecolochem, Inc., RichardSmallwood,(800)446-8004
CECOS, Ernest C. Neal, (716) 873-4200
Users: Widespread.
EPA Contact: S. Garry Howell, (513) 569-7756
26
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Technology:
Oxidation by Hydrogen
Peroxide (H2O2)
Brief Description: Addition of H202 to oxidize
organic compounds. H202 can be used as a source of
oxygen for biodegradation.
Applicability/Limitation: Non-specific reaction.
May be exothermic/explosive or require addition of
heat and/or catalysts. Probably not applicable for in-
situ treatment; may be used for surface treatment of
contaminated ground water/sludges.
Status/Availability: Common industrial unit pro-
cess.
Manufacturer Various, FMC sells hydrogen per-
oxide and nutrient for biodegradation specifically for
petroleum treatment.
Users:
EPA Contact: Ronald Lewis, (513) 569-7856
Technology: Oxidation by Hypochlorites
Brief Description: Addition of sodium or calcium
hypochlorite (bleaching agents) to oxidize organic
wastes.
Applicability/Limitation: May produce toxic chlo-
rinated organic by-products. Must be done under
controlled (not in-situ) conditions, i.e., batch reactors.
Non-specific reaction.
Status/Availability: Used in industrial processes.
Manufacturer: See buyer's guide in trade journals.
Users:
EPA Contact: Donald Sanning, (513) 569-7875
Technology: Ozonation
Brief Description: Ozonation is a chemical oxida-
tion process appropriate for aqueous streams which
contain less than 1.0 percent oxidizable compounds.
Applicability/Limitation: Ozone can be used to
pretreat wastes to breakdown refractory organics or
as a polishing step after biological or other treatment
processes to oxidize untreated organics. Ozone is
currently used for treatment of hazardous wastes to
destroy cyanide and phenolic compounds. The rapid
oxidation of cyanides with ozone offers advantages
over the slower alkaline chlorination method. Limita-
tions include the physical form (i.e., sludges and
soilds) and nonselective competition with other
species.
Status/Availability: Commercially available.
Manufacturer: See buyer's guides or trade journal.
Users: Widespread.
EPA Contact: S. Garry Howell, (513) 569-7756
Donald Sanning, (513) 569-7875
27
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Technology: Plasma Systems
Brief Description: This technology uses a plasma
arc device to create extremely high temperatures
(temperatures approach 10,000°C) for waste destruc-
tion in highly toxic liquids. Gaseous emissions (mostly
H2, CO), acid gases in the scrubber and ash com-
ponents in scrubber water are the residuals. The
system's advantages are that it can destroy refractory
compounds, the equipment can be made portable and
typically the process has a very short on/off cycle.
Applicability/Limitation: Used to treat liquid
wastes containing organics, pesticides, PCBs, dioxins
or halogenated organics. The process is limited to
liquids and continuous operation has not been
demonstrated.
Status/Availability: Pilot-plant stage with demon-
stration in progress, mobile pilot plant available.
Manufacturer: Pyrolysis Systems, Inc., Ed Fox
(416)735-2401
Applied Energetics, Inc., John Dicks, (615) 455-0631
Westinghouse
Users:
EPA Contact: Harry M. Freeman, (513) 569-7529
Process schematic of the psi plasma pyrolysis unit.
Off Gases to Flare
Emergency Carbon Filter
Gas Chromatograph-
Mass Selectivity Unit
Laboratory
Analysis Equipment
Gas Chromatograph
Cooling Water
Salt Water to Dram
Technology: Polymerization
Brief Description: Polymerization uses catalysts to
convert a monomer or a low-order polymer of a
particular compound to a larger chemical multiple of
itself which has different properties for in-place
stabilization.
Applicability/Limitation: This technology treats
organics including aromatics, aliphatics and oxygen-
ated monomers such as styrene, vinyl chloride,
isoprene acrylonitrile, etc. Limited application to spills
of these compounds.
Status/Availability: Has been used at spills.
Manufacturer: Not applicable.
Users:
EPA Contact: Carlton Wiles, (513) 569-7795
28
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Technology:
Portland Cement Pozzolan
Stabilization/Solidification
Brief Description: Mixes the waste with Portland
cement to incorporate the waste into the cement
matrix. This improves handling and is inexpensive
(plentiful raw materials).
Applicability/Limitation: Effective for metal cat-
ions, latex and solid plastic wastes. Large amounts of
dissolved sulfate salts, or metallic anions such as
arsenate and borates will hamper solidification.
Organic matter, lignite, silt or clay will increase setting
time.
Status/Availability: Commercially available.
Manufacturer: Aerojet Energy Conversion
Company, Sacramento, California
ATCOR, Inc., Peekskill, New York
Chem-Nuclear Systems, Inc., Bellevue, Massachu-
setts
Delaware Custom Materials, Cleveland, Ohio
Energy, Inc., Idaho Falls, Idaho
General Electric Company, San Jose, California
Hittman Nuclear and Development Company,
Columbia, Maryland
Stock Equipment Company, Cleveland, Ohio
Todd Research and Technical Division, Galveston,
Texas
United Nuclear Industries, Richland, Washington
Westinghouse Electric Company, Pittsburgh, Penn-
sylvania
Users:
EPA Contact: Robert Landreth, (513) 569-7836
Technology: Pyrolysis Processes
Brief Description: Pyrolysis consists of heating
material in the absence of air in order to thermally
degrade to a volatile gaseous portion and residual
solid comprised of fixed carbon and ash. There are two
main ways to heat the material. One is by direct
heating where the material is heated by direct contact
with hot combustion products. The result of direct
heating is an off-gas that is a combination of volatiles
from the waste and burner flue products. Another
method is indirect heating. This method keeps the
burner flue products from mixing with the volatiles.
Indirect heating is the necessary mode of heating if
resource recovery is to be attempted, but it is also
more complex and more expensive than direct heating.
Indirect heating will probably prove economical only in
very large units. Because of the drawbacks of indirect
heating Midland-Ross is concentrating on smaller
units that can convert the waste to a preheated
gaseous fuel and burn the fuel near the pyrolyzer. In
this way direct heating imposes almost no penalty on
overall fuel efficiency.
The pyrolysis equipment is designed to convert
waste that is not suited for boiler fuel, into a gaseous
fuel. The main objective of this system is to convert
waste material from a disposal problem to a gaseous
fuel source.
Applicability/Limitation: This technology is used
to treat viscous liquids, sludges, solids, high ash
materials, salts and metals and halogenated wastes.
The limitations are that it requires a homogeneous
waste input and metals and salts in the residue can be
teachable.
Status/Availability: Commercially available batch
and continuous.
Manufacturer: Midland-Ross Corporation, (419)
547-6444
Users:
EPA Contact: Harry M. Freeman, (513) 569-7529
29
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Technology: Rotary Kiln Incineration
Brief Description: Wastes and auxiliary fuel are
introduced to the high end of the kiln which is slightly
inclined to horizontal. Wastes are oxidized, or com-
busted as they move through the kiln due to its
rotation. Exhaust gases from the kiln pass to a
secondary chamber, or afterburner for further oxida-
tion. Ash residues are discharged and collected from
the low end of the kiln. Exhaust gases may require
acid gas and particulate removal, and the ashes may
require solidification before landfilling.
Applicability /Limitation: Most types of solid, liquid
and gaseous organic wastes can be treated with this
technology. Wastes with high inorganic salt content
and heavy metals as well as explosive wastes require
special evaluation.
Status /A vailability:
wide use.
Commercially availableand in
Manufacturer: S. D. Myers, Inc., Joe Isle, (415)
794-6301
American Industrial Waste of ENCSO, Inc., (Mobile),
(615)383-1691
Exceltech, Inc., (415) 659-0404
International Waste Energy System, Dwight Brown,
(314)389-7275
Winston Technology, Inc., (Mobile), (914) 273-6533
Industronics, Inc., (203) 289-1551
VolundUSA, (312)655-1490
Thermal
TR Systems
C & H Combustion
CE Raymond
Von Roll
Users: EPA-ORD, Denny Farm Site near McDonnell,
Missouri.
EPA Contact: James Yezzi, (201) 321-6677
Technology: Soil Flushing/Soil Washing
Brief Description: Soil flushing is in-situ extraction
of inorganic or organic compounds from soils by
passing extractant solutions through the soils. These
solutions may include water, surfactants, acids or
bases (for inorganics), chelating agents, oxidizing and
reducing agents. Soil washing consists of similar
treatment, but the soil is excavated and treated at the
surface in a soil washer.
Applicability/Limitation: Soil flushing/washing
fluids must have good extraction coefficients, low
volatility and toxicity, be safe and easy to handle, and
most important, be recoverable/recyclable. Most
promising for extraction of heavy metals, problems
likely in dry or organic-rich soils. Care must be taken
that the soil pores are not clogged. This can happen
with certain surfactants tested for in-situ extraction.
Status/Availability: Limited full-scale testing.
Manufacturer: USEPA, Edison, New Jersey, has
mobile soil washer, other systems under develop-
ment.
Users: Technology has been developed by oil indus-
try (tertiary recovery) and mining (metal leaching).
EPA Contact: Richard Traver, (201) 321-6677
Technology: Sorption
Brief Description: Contaminants are bound up in
pozzolan-type matrices by physical sorption or chemi-
sorption yielding a stabilized material which is easier
to handle. Liquid immobilization depends on added
ingredients. This process results in high concentra-
tions of contaminants at the surface of the material
and contaminants may leach. The treated material is
permeable.
Applicability/Limitation: For organics and inorgan-
ics. Advantages to this technology include plentiful
raw materials, mixing technology known, improved
handling, inexpensive additives, minimum pretreat-
ment, bearing strength adequate for landfill. Dis-
advantages—large volume of additives, poor leachate
control, placement sensitive, limited bearing strength,
free water may be released under high pressure and
there is temperature sensitivity.
Status/ A vailability:
Manufacturer:
Users:
EPA Contact: Robert Landreth, (513) 569-7836
30
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Technology: Steam Stripping
Brief Description: Uses steam to remove organics
from aqueous wastes. Steam stripping is essentially a
continuous fractional distillation process carried out
in a packed or tray tower. Clean steam rather than
reboiled bottoms provides direct heat to the tower.
The resulting residuals are contaminated steam
condensate, recovered solvent, and "stripped" efflu-
ent.
Applicability/Limitation: Used to treat aqueous
wastes contaminated with chlorinated hydrocarbons,
aromatics such as xylenes, ketones such as acetone
or MEK, alcohols such as methanol and high boiling
point chlorinated aromatics such as penta-chloro-
phenol. Steam stripping will treat less volatile and
more soluble wastes than air stripping and can
handle a wide concentration range from less than
100 ppm to 10 percent organics.
Status /Availability: USEPA has transportable unit.
Manufacturer:
Users:
EPA Contact: Ron Turner, (513) 569-7775
Steam stripping column—perforated tray type.
Organic
Vapors
Liquid
Feed
Flow
Steam
Heat
Stripped
Effluent
Source: Pfaudler, Rochester, New York
Technology: Sulfur Regeneration Units
Brief Description: Proprietary sulfuric acid regen-
eration unit is used to combust high sulfur refinery
waste. Sulfur is recovered from the combustion gases
using a double contact-double absorption sulfuric
acid plant. The furnace operates above 1600°F, and
has a long residence time (greater than 1 second).
Applicability/Limitation: Can destroy hazardous
waste with high sulfur content. Particularly appicable
to high sulfur, high Btu refinery wastes.
Status/Availability: Limited.
Manufacturer:
cess.
Stauffer Chemical proprietary pro-
Users: Destroys on-site generated wastes.
EPA Contact: Harry Freeman, (513) 569-7529
31
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Technology: Supercritical Extraction
Brief Description: At a certain combination of
temperature and pressure, fluids reach their critical
point beyond which their solvent properties are
greatly altered. These properties make extraction
more rapid and efficient than processes using distil-
lation and conventional solvent extraction methods.
This technology has not been applied to PCBs. No cost
or time estimates are available. Presently, the EPA
has contracted Critical Fluid Systems, Inc., to investi-
gate the use of supercritical carbon dioxide to extract
hazardous organics from aqueous streams.
Applicability/Limitation: This technology is used
to extract hazardous waste from the soil. It is limited
at this time because it is new and it appears that the
capital cost is high.
Status/Availability: Laboratory tests only.
Manufacturer:
Users:
EPA Contact: Charles Rogers, (513) 569-7757
Technology: Supercritical Water
Oxidation
Brief Description: The supercritical water oxidation
process is basically a high temperature, high pressure
wet air oxidation. The unique properties of water
above 500°C or 705°F (supercritical region) cause it
to act as an excellent non-polar solvent for nearly all
organic materials. Aqueous solutions or slurries
(organic content >5 percent) are mixed with high-
pressure oxygen (3200 to 3600 psi or >218 atms) to
chemically oxidize wastes in less than one minute
with >99.99 percent efficiency. The process is an
emerging technology which may be less expensive
than high-temperature incineration for destruction of
organically contaminated aqueous wastes.
Two processing approaches have been evaluated:
an above-ground pressure vessel reactor (MODAR)
and the use of an 8,000 to 10,000-ft well reactor
(Vertox). The SCW process is best suited for large
volume (200 to 1000 gpm) dilute (1.0 to 10,000 mg/l
COD) aqueous wastes that are of a volatile nature and
that contain sufficient Btu's to sustain the process. In
many applications, high Btu non-hazardous wastes
can be mixed with low Btu hazardous wastes to
provide the heat energy needed to make the process
self sustaining. Emissions/residues include gaseous
effluent (nitrogen and carbon dioxide), precipitation of
inorganic salts and the liquid containing only soluble
inorganic acids and salts. The advantages are rapid
oxidation rates, complete oxidation of organics,
efficient removal of inorganics and no off-gas pro-
cessing is required.
Applicability/Limitation: Used to treat aqueous
organic solution/slurry and mixed organic/inorganic
waste. Sophisticated equipment and operations and
long-term continuous operation have not been
demonstrated, thereby limiting its use.
Status/Availability: Demonstration completed in
1985, commercial unit available in 1987.
Manufacturer: Vertox Corporation, Dallas, Texas
MODAR, Inc., Natick, Texas (pilot scale)
Users:
EPA Contact: Harry M. Freeman, (513) 569-7529
Charles Rogers, (513) 569-7757
32
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Technology: Ultraviolet Photolysis
Brief Description: Ultraviolet photolysis (UV) is a
process that destroys or detoxifies hazardous chem-
icals in aqueous solutions utilizing UV irradiation.
Natural photolysis of dioxins has been observed on
soil surfaces although the degree of reaction is
limited by the depth of penetration of the UV. Ultra-
violet light has been used for degradation of dioxins in
waste sludge. This process requires extraction of the
dioxins into a clean transparent solvent. Reaction
products are dechlorinated phenolic materials includ-
ing ethoxylated phenol. Use of UV photolysis on a
liquid dioxin waste required six extractions to reduce
the dioxin content from 343 ppm to 0.2 ppm.
Photolysis of the extracted dioxin reduced dioxin level
to less than 0.1 ppm after 20 hours. Overall destruc-
tion efficiency was 99.94 percent.
Applicability/Limitation: The inability of UV light
to penetrate and destroy pollutants in soil or opaque
solutions is a limitation of this approach. Photolysis
can be enhanced by simultaneous introduction of
ozone.
Status/Availability: Laboratory scale.
Manufacturer: SYNTEX
Users:
EPA Contact: Charles Rogers, (513) 569-7757
Technology: Vitrification
Brief Description: Large electrodes are inserted
into soils containing significant levels of silicates.
Graphite on the soil surface connects the electrodes.
A high current of electricity passes through the
electrodes and graphite. The heat causes a melt that
gradually works downward through the soil. Some
contaminant organics are volatilized and escape from
the soil surface and may be collected by a vacuum
system. Inorganics and some organics are trapped in
the melt that as it cools becomes a form of obsidian or
very strong glass.
Applicability/Limitation: Originally tested as a
means of solidification/immobilization of low level
radioactive metals. May also be useful for forming
barrier walls (e.g., equivalent to slurry wall construc-
tion). This later use needs testing and evaluation to
determine how uniform the wall would be and stability
of the material over a period of time.
Status /A vailability:
Manufacturer: Battelle Northwest has developed
methods. Currently negotiating for commercial li-
cense by others.
Users:
EPA Contact: Donald Sanning, (513) 569-7875
33
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Technology: Wet Air Oxidation
Brief Description: Uses elevated temperature and
pressure to oxidize organics. The oxidation products
stay in liquid as do the inorganics. The off-gas low in
nitrogen oxides, sulfur oxides and particulates. Off-
gas treatment may be used for hydrocarbon emissions.
The advantages are that it is thermally self-sustaining,
accepts waste with organic concentrations range
between biological treatment and incineration,
detoxifies priority pollutants and the products of
oxidation and stay in the liquid phase. Wet air
oxidation is particularly well suited for treating
organic compounds in aqueous waste streams that
are too dilute (<15 percent organics) to treat econom-
ically by incineration. Oxidation of the organic
compounds occurs when the aqueous solution is
heated to about 300°C and 137 atm in the presence of
compressed air. Typically, 80 percent of the organic
substances will be completely oxidized. The system
can accommodate some partially halogenated com-
pounds, but highly chlorinated species such as PCBs,
are too stable for complete destruction without the
addition of catalysts.
Applicability/Limitation: Used to treat aqueous
waste streams with less than 5 percent organics and
with some pesticides, phenolics and organic sulfur,
cyanide wastewaters. It is not recommended for
aromatic halogenated organics. This technology is
not economical for dilute or concentrated wastes and
it is not appropriate for solids or viscous liquids.
Status/Availability: Available at commercial scale.
Manufacturer: Zimpro, Inc., William Copa, (715)
359-7211
MODAR, Inc., (617) 655-7741
Vertech Treatment Systems, (303) 452-8800
Users:
unit.
Casmalia Resources, 10-gpm demonstration
EPA Contact: Harry M. Freeman, (513) 569-7529
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Bibliography
1. Martin, Edward J., Oppelt, E. T., and Smith, B. P., Chemical, Physical,
Biological Treatment of Hazardous Wastes, Paper to the 5th U.S./Japan
Conference of Solid Wastes Management, Tokyo, Japan, Sept. 1982.
2. Oppelt, E. T., Pretreatment of Hazardous Wastes, Paper to the U.S./Spain
Joint Seminar on the Treatment and Disposal of Hazardous Wastes, Madrid,
Spain, May 1986.
3. Metcalf & Eddy, Inc., Engineers Briefing: Technologies Applicable to
Hazardous Waste, for USEPA, HWERL, Cincinnati, Ohio, May 1985.
4. Contributions by various participants of the RCRA/CERCLA Alternative
Treatment Technology Seminar, CERI (Center for Environmental Research
Information), USEPA, Cincinnati, Ohio, May 1986.
5. Turner, Ronald J., A Review of Treatment Alternatives for Wastes
Containing Nonsolvent Halogenated Organics, USEPA, HWERL, Cincinnati,
Ohio, 1986.
6U.S. GOVERNMENT PRINTING OFFICE: 1986-646-116 40606
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