EPA/540/2-89/041
SUPERFUND TREATABILITY
CLEARINGHOUSE
Document Reference:
Alliance Technologies Corp. 'Technical Resource Document: Treatment
Technologies for Dioxin-Containing Wastes." Technical Report EPA/600/2-86/096.
244pp. October 1986.
EPA LIBRARY NUMBER:
Super-fund Treatability Clearinghouse - FCFR-3 ,q,
U,S. Environmental Protection Agency
Region 5, Library (PL-!?1)
77 West Jackson D;.v - < 2'h Floor
Chicago, IL 60604-:^ " "
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SUPERFUND TREATABILITY CLEARINGHOUSE ABSTRACT
Treatment Process: Thermal Treatment - Circulating Bed Combustion
Media: Soil/Generic
Document Reference: Alliance Technologies Corp. "Technical Resource
Document: Treatment Technologies for Dioxin/
Containing Vastes." Technical Report
EPA/600/2-86/096. 244 pp. October 1986.
Document Type: EPA ORD Report
Contact: Harold Freeman
U.S. EPA, ORD
26 W. St. Clair Street
HWERL-Thermal Destruction Branch
Cincinnati, OH 45268
4513-569-7529
Site Name: Denny Farm Site, MO (Non-NPL)
Location of Test: Denny Farm, MO
BACKGROUND; GA Technologies conducted the circulating bed combustor (CBC)
pilot scale tests using PCB-contaminated soils. This treatability study
compiles available information on those technologies for dioxin containing
solids, liquids and sludges, many of which are in early stages of develop-
ment. Discussion of the CBC pilot test is contained in this abstract.
Other technologies in this document are discussed in Document Numbers
FCFR-4 and FCFR-6. Technologies evaluated were those that destroy or
change the form of dioxin to render it less toxic. Those technologies not
tested on dioxin-containing wastes had been tested on PCB-containing
wastes. The report divides the technologies into thermal and non-thermal
groups for discussion. It was noted that incineration was the only suffi-
ciently demonstrated technology for treatment of dioxin containing wastes
(51 FR 1733) and RCRA Performance Standards for Thermal Treatment require
99.9999 percent destruction removal efficiency (ORE) of the principal
organic hazardous constituent (POHC). Factors which affect the selection/
use of a particular technology are discussed. Technical performance for
treating a specific waste type and costs are both considered in this
discussion. A summary of dioxin treatment processes, their performance/
destruction achieved, and estimated costs are provided in Table 1. QA/QC
is not discussed.
OPERATIONAL INFORMATION; GA Technologies conducted trial burns on PCB-
contaminated soil with 9800 to 12,000 ppm of PCB. Auxiliary fuel was used
to maintain the bed temperature at 1600 to 1800°F. A soil feed rate of
325 to 410 pounds per hour was used.
PERFORMANCE; A destruction efficiency exceeding six nines (99.9999 per-
cent) was achieved. Costs of fluidized bed treatment are dependent on fuel
requirements, scale and site conditions. Cost estimates of from $27/ton to
$150/ton are provided for various assumptions.
3/89-35 Document Number: FCFR-3
NOTE: Quality assurance of data may not be appropriate for all uses.
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CONTAMINANTS;
Analytical data is provided in the treatability study report. The
breakdown of the contaminants by treatability group is:
Treatability Group CAS Number Contaminants
W02-Dioxins/Furans/PCBs 1336-36-3 Total PCBs
Note: This is a partial listing of data. Refer to the document for more
information.
3/89-35 Document Number: FCFR-3
NOTE: Quality assurance of data may not be appropriate for all uses.
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TABLE 1
SUMMARY OF DIOXIN TREATMENT PROCESSES
Process Name
Stationary Rotary
Kiln Incineration
Mobile Rotary
Kiln Incineration
Liquid Injection
Incineration
Fluidized-bed
Incineration
Infrared Incinerator
(Shirco)
High Temperature
Fluid Wall (Huber AER)
Molten Salt
(Rockwell Unit)
Supercritical
Water Oxidation
Plasma Arc
Pyrolysis
In-Situ
Vitrification
Solvent Extraction
Stabilization/
Fixation
UV Photolysis
Chemical Dechlor-
ination APEG processes
Biological in situ
addition of microbes
Degradation using
Ruthemium Tetroxide
Degradation using
Chloroiodides
Performance/Destruction Achieved
Greater than 99.999 DRE demonstrated
on dioxin at combustion research
facility
Greater than 99.9999 DRE for dioxin
by EPA unit; process residuals
delisted
Ocean incinerators only demonstrated
99.9 on dioxin-containing herbicide
orange
Greater than 99.9999 DRE demonstrated
on PCBs
Greater than 99.9999 DRE on
TCDD-contaminated soil
Greater than 99.999 DRE on TCDD-
contaminated soil
Up to eleven nines DRE on
hexachlorobenzene
99.9999 DRE on dioxin-containing
waste reported by developer
Greater than 99.9999 destruction of
PCBs and CC14
Greater than 99.9% destruction on
PCB-contaminated soil
Still bottom extraction: 340 ppm
TCDD reduced to 0.2 ppm; 60-90%
removal from soils.
Tests using cement decreased
leaching of TCDD
Greater than 98.7% reduction of TCDD
Reduction of 2,000 ppb TCDD to below
1 ppb for slurry (batch process)
50-60% metabolism of 2,3,7,8-TCDD
using white rot fungus
Reduction of 70 ppb TCDD to below
10 ppb in 1 hr
Up to 92% degradation on solution
of TCDD in benzene
Cost
$0.25 - $0.70/lb
for PCB solids
NA
$200 - $500/ton
$60 - $320/ton
$200 - $1,200
per ton
$300 - $600/ton
NA
$0.32 - $2.00/
gallon
$300 - $l,400/ton
$120 - $250/M3
NA
NA
$250 - $l,200/ton
$296/ton for in situ,
$ 91/ton for slurry
NA
NA
NA
3/89-35 Document Number: FCFR-3
NOTE: Quality assurance of data may not be appropriate for all uses.
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SUPERFUND TREATABILITY CLEARINGHOUSE ABSTRACT
Treatment Process:
Media:
Document Reference:
Document Type:
Contact:
Site Name:
Location of Test:
Thermal Treatment - Pyrolysis
Soil/Generic
Alliance Technologies Corp. "Technical Resource
Document: Treatment Technologies for Dioxin-
Containing Wastes." Technical Report
EPA/600/2-86/096. 244 pp. October 1986.
EPA ORD Report
Harold Freeman
U.S. EPA, ORD
HWERL-Thermal Destruction Branch
26 W. St. Clair Street
Cincinnati, OH 45268
4513-569-7529
Times Beach, MO (NPL)
Times Beach, MO
BACKGROUND; This report focuses on the pilot scale Advanced Electric
Reactor (AER). This treatability study compiles available information on
those technologies for dioxin containing solids, liquids and sludges, many
of which are in early stages of development. A discussion of the AER pilot
test is contained in this abstract. Other technologies in this document
are discussed in Document Numbers FCFR-3 and FCFR-6. Technologies evalu-
ated were those that destroy or change the form of dioxin to render it less
toxic. Those technologies not tested on dioxin-containing wastes had been
tested on PCB-containing wastes. The report divides the technologies into
thermal and non-thermal groups for discussion. It was noted that inciner-
ation was the only sufficiently demonstrated technology for treatment of
dioxin containing wastes (51 FR 1733) and RCRA Performance Standards for
Thermal Treatment require 99.9999 percent destruction removal efficiency
(ORE) of the principal organic hazardous constituent (POHC). Factors which
affect the selection/use of a particular technology are discussed. Techni-
cal performance for treating a specific waste type and costs are both
considered in this discussion. A summary of dioxin treatment processes,
their performance/destruction achieved, and estimated costs are provided in
Table 1. QA/QC is not discussed.
OPERATIONAL INFORMATION: The AER, owned and operated by J.M. Huber
Corporation, was used to treat, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).
It was also used in other tests including tests at Gulfport, Mississippi,
but these tests reported only removal efficiencies. Only two data points
are present from the Times Beach trials, one from the treated soil and one
from the baghouse catch.
The AER was operated at 3500°F-4000°F. Heating was accomplished using
electrically heated carbon electrodes. A nitrogen purge gas provided the
3/89-36 Document Number: FCFR-4
NOTE: Quality assurance of data may not be appropriate for all uses.
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reaction atmosphere. Since oxygen was not present, it was run in a
pyrolytic manner.
PERFORMANCE; High DREs could not be demonstrated due to the low amount of
contamination (79 ppb in the influent soil). One limitation of the AER is
that it cannot handle two-phase materials such as sludge. Soils should be
dried and sized (smaller than 10 mesh) before being fed into the reactor.
Another limitation is that other types of incineration processes are more
cost effective for high BTU content material. Since no supplementary fuels
are required, this process is better suited for low BTU material. A cost
estimate guideline is included. Recently the U.S. EPA and the Texas Water
Commission jointly issued J.M. Huber Corporation a RCRA permit which
authorizes the incineration of any non-nuclear RCRA hazardous waste in the
AER.
CONTAMINANTS;
Analytical data is provided in the treatability study report. The
breakdown of the contaminants by treatability group is:
Treatability Group CAS Number Contaminants
W02-Dioxins/Furans/PCBs 1746-01-6 2,3,7,8-Tetrachloro-
dibenzo-p-dioxin
1336-36-3 Total PCBs
Notes This is a partial listing of data. Refer to the document for more
information.
3/89-36 Document Number: FCFR-4
NOTE: Quality assurance of data nay not be appropriate for all uses.
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TABLE 1
SUMMARY OF DIOXIN TREATMENT PROCESSES
Process Name
Stationary Rotary
Kiln Incineration
Mobile Rotary
Kiln Incineration
Liquid Injection
Incineration
Fluidized-bed
Incineration
Infrared Incinerator
(Shirco)
High Temperature
Fluid Wall (Huber AER)
Molten Salt
(Rockwell Unit)
Supercritical
Water Oxidation
Plasma Arc
Pyrolysis
In-Situ
Vitrification
Solvent Extraction
Stabilization/
Fixation
UV Photolysis
Chemical Dechlor-
ination APEG processes
Biological in situ
addition of microbes
Degradation using
Ruthemium Tetroxide
Degradation using
Chloroiodides
Performance/Destruction Achieved
Greater than 99.999 ORE demonstrated
on dioxin at combustion research
facility
Greater than 99.9999 ORE for dioxin
by EPA unit; process residuals
delisted
Ocean incinerators only demonstrated
99.9 on dioxin-containing herbicide
orange
Greater than 99.9999 DRE demonstrated
on PCBs
Greater than 99.9999 DRE on
TCDD-contaminated soil
Greater than 99.999 DRE on TCDD-
contaminated soil
Up to eleven nines DRE on
hexachlorobenzene
99.9999 DRE on dioxin-containing
waste reported by developer
Greater than 99.9999 destruction of
PCBs and
Cost
$0.25 - $0.70/lb
for PCB solids
NA
$200 - $500/ton
$60 - $320/ton
$200 - $1,200
per ton
$300 - $600/ton
NA
$0.32 - $2.00/
gallon
$300 - $l,400/ton
$120 - $250/M3
NA
Greater than 99.9% destruction on
PCB-contaminated soil
Still bottom extraction: 340 ppm
TCDD reduced to 0.2 ppm; 60-90%
removal from soils.
Tests using cement decreased NA
leaching of TCDD
Greater than 98.7% reduction of TCDD $250 - $l,200/ton
Reduction of 2,000 ppb TCDD to below
1 ppb for slurry (batch process)
50-60% metabolism of 2,3,7,8-TCDD
using white rot fungus
Reduction of 70 ppb TCDD to below
10 ppb in 1 hr
Up to 92% degradation on solution
of TCDD in benzene
$296/ton fo-r in situ,
$ 91/ton for slurry
NA
NA
NA
3/89-36 Document Number: FCFR-4
NOTE: Quality assurance of data may not be appropriate for all uses.
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SUPERFUND TREATABILITT CLEARINGHOUSE ABSTRACT
Treatment Process: Physical/Chemical - Dechlorination
Media: Soil/Generic
Document Reference: Alliance Technologies Corp. "Technical Resource
Document: Treatment Technologies for Dioxin-
Containing Wastes." Technical Report
EPA/600/2-86/096. 244 pp. October 1986.
Document Type: EPA ORD Report
Contact: Harold Freeman
U.S. EPA, ORD
HWERL-Thermal Destruction Branch
26 W. St. Clair Street
Cincinnati, OH 45268
513-569-7529
Site Name: Denny Farm Site, MO (Non-NPL)
Location of Test: Denny Farm, MO
BACKGROUND; This document summarizes several case studies on the applica-
tions of the Alkali Polyethylene Glycolate (APEG) treatment process applied
to dioxin-contaminated soil. This treatability study compiles available
information on those technologies for dioxin containing solids, liquids and
sludges, many of which are in early stages of development. A discussion of
the APEG technology is contained in this abstract. Other technologies are
discussed in Document Numbers FCFR-3 and FCFR-4. Technologies evaluated
were those that destroy or change the form of dioxin to render it less
toxic. Those technologies not tested on dioxin-containing wastes had been
tested on PCB-containing wastes. The report divides the technologies into
thermal and non-thermal groups for discussion. It was noted that incinera-
tion was the only sufficiently demonstrated technology for treatment of
dioxin containing wastes (51 FR 1733) and RCRA Performance Standards for
Thermal Treatment require 99.9999 percent destruction removal efficiency
(DRE) of the principal organic hazardous constituent (POHC). Factors which
affect the selection/use of a particular technology are discussed. Techni-
cal performance for treating a specific waste type and costs are both
considered in this discussion. A summary of dioxin treatment processes,
their performance/ destruction achieved, and estimated costs are provided
in Table 1. QA/QC is not discussed.
OPERATIONAL INFORMATION; This document summarized several case studies on
the applications of the Alkali Polyethylene Glycolate (APEG) treatment
process applied to dioxin-contaminated soil. All data are either bench or
pilot scale. Two different molecular weight APEG reagents were used.
Three tests were K-400 (potassium-based reagent and polyethylene glycol of
average molecular weight of 400) and two tests were K-120. It is unclear
whether the waste matrix was a solvent, soil, or contaminated debris. All
analyses reported were total waste analyses.
3/89-38 Document Number: FCFR-6
NOTE: Quality assurance of data may not be appropriate for all uses.
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PERFORMANCE; The document concludes that this technology has a potential
for treating soil contaminated with dioxins. Efficiencies improve with
increased temperature. Costs for the slurry process is estimated at
$91/ton and for the in situ process of $296/ton.
CONTAMINANTS!
Analytical data is provided in the treatability study report. The
breakdown of the contaminants by treatability group is:
Treatability Group CAS Number Contaminants
W02-Dioxins/Furans/PCBs 1336-36-3 Total PCBs
1746-01-6 2,3,7,8-Tetrachlorodi-
benzo-p-dioxins
Note: This is a partial listing of data. Refer to the document for more
information.
3/89-38 Document Number: FCFR-6
NOTE: Quality assurance of data may not be appropriate for all uses.
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TABLE 1
SUMMARY OF DIOXIN TREATMENT PROCESSES
Process Name
Stationary Rotary
Kiln Incineration
Mobile Rotary
Kiln Incineration
Liquid Injection
Incineration
Fluidized-bed
Incineration
Infrared Incinerator
(Shirco)
High Temperature
Fluid Wall (Huber AER)
Molten Salt
(Rockwell Unit)
Supercritical
Water Oxidation
Plasma Arc
Pyrolysis
In-Situ
Vitrification
Solvent Extraction
Stabilization/
Fixation
UV Photolysis
Chemical Dechlor-
ination APEG processes
Biological in situ
addition of microbes
Degradation using
Ruthemium Tetroxide
Degradation using
Chloroiodides
Performance/Destruction Achieved
Greater than 99.999 ORE demonstrated
on dioxin at combustion research
facility
Greater than 99.9999 ORE for dioxin
by EPA unit; process residuals
delisted
Ocean incinerators only demonstrated
99.9 on dioxin-containing herbicide
orange
Greater than 99.9999 ORE demonstrated
on PCBs
Greater than 99.9999 ORE on
TCDD-contaminated soil
Greater than 99.999 ORE on TCDD-
contaminated soil
Up to eleven nines ORE on
hexachlorobenzene
99.9999 ORE on dioxin-containing
waste reported by developer
Greater than 99.9999 destruction of
PCBs and
Cost
Greater than 99.9% destruction on
PCB-contaminated soil
Still bottom extraction: 340 ppm
TCDD reduced to 0.2 ppm; 60-90*
removal from soils.
Tests using cement decreased
leaching of TCDD
Greater than 98.7% reduction of TCDD
Reduction of 2,000 ppb TCDD to below
1 ppb for slurry (batch process)
50-60% metabolism of 2,3,7,8-TCDD
using white rot fungus
Reduction of 70 ppb TCDD to below
10 ppb in 1 hr
Up to 92% degradation on solution
of TCDD in benzene
$0.25 - $0.70/lb
for PCB solids
NA
$200 - $500/ton
$60 - $320/ton
$200 - $1,200
per ton
$300 - $600/ton
NA
$0.32 - $2.00/
gallon
$300 - $1,AGO/ton
$120 - $250/M3
NA
NA
$250 - $l,200/ton
$296/ton for in situ,
$ 91/ton for slurry
NA
NA
NA
3/89-38 Document Number: FCFR-6
NOTE: Quality assurance of data nay not be appropriate for all uses.
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united states
Environmental •>rotect on
Agency
~iazaraoL,s vVaste Engineering
^esear:"i Laooratory
Cincinnati OH 45268
E=>A SCO 2-36
Octooe^ ' 985
Research and Development
•-TSI-KT-
Technical Resource
Document:
*
Treatment
Technologies for
Dioxin-Containing
Wastes
-------
EPA/600/2-86/096
October 1986
TECHNICAL RESOURCE DOCUMENT
TREATMENT TECHNOLOGIES FOR DIOXIN-CONTAINING WASTE
by
Mark Ar1ent1
Lisa W1lk
Michael Jasinski
Nancy Prom1nsk1
Alliance Technologies Corporation
Bedford, MA 01730
EPA Contract Number 68-03-3243
Project Officer
Harry M. Freeman
Alternative Technologies Division
Hazardous- Waste Engineering Research Laboratory
Cincinnati, OH. 45268
HAZARDOUS HASTE ENGINEERING RESEARCH LABORATORY
OFFICE OF RESEARCH A DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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FOREWORD
As hazardous waste continues to be one of the more prominent
environmental concerns to the people of the United States and other countries
throughout the world, there are continuous needs for research to characterize
problems and develop and evaluate alterantives to addressing those problems.
The programs of the Hazardous Waste Engineering Research Laboratory are
designed to contribute to satisfying these research needs.
This Technical Resource Document for Treatment Technologies for Dioxin
Containing Wastes compiles available information on those technologies. It is
intended to provide support for the land disposal prohibition, currently being
considered by the EPA, and to provide technical information for those
individuals and organizations concerned with the subject waste streams. Those
wishing additional information on the various technologies should contact the
Hazardous Waste Engineering Research Laboratory.
Thomas R. Hauser
Director
Hazardous Waste Engineering Research Laboratory
iii
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FIGURES
Number Page
3.1 Structure of (a) Dibenzo-p-dioxin and (b) dibenzofuran . . 3-5
4.1.L Schematic of Rollins Environmental Services' incinerator. . 4-6
4.1.2 Schematic of ENSCO stationary incinerator 4-7
4.1.3 Simplified schematic of CRF rotary kiln 4-10
4.2.1 Schematic of EPA mobile incineration system 4-17
4.2.2 Schematic of ENSCO MWP-2000 mobile rotary kiln incinerator. 4-19
4.3.1 Vertically-oriented liquid injection incinerator 4-33
4.4.1 Cross-section of fluidized bed furnace 4-42
It
4.4.2 Schematic of circulating bed combustor 4-44
4.5.1 Advanced electric reactor (AER) 4-53
4.5.2 High temperature fluid vail process configuration for
the destruction of carbon tetrachloride 4-54
4.7.1 Pyroplasma process flow diagram 4-66
4.8.1 Schematic of generalized molten salt incinerator design.. . 4-74
4.9.1 Process schematic for oxidation of an aqueous waste with
a heating value of 1750 Btu/lb 4-81
4.10.1 Schematic of an in situ vitrification operation 4-89
4.10.2 Schematic of large scale off-gas treatment system 4-91
4.10.3 Cost of in situ vitrification for transuranic wastes as a
function of electrical rate and soil moisture 4-94
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TABLES
Number Page
1.1 Dioxin Contaminated Wastes Listed as RCRA Hazardous Wastes,
January 14, 1985, 50 FR 1978 1-2
1.2 Summary of Dioxin Waste Sources and Quantities ........ 1-6
1.3 Summary of Treatment Processes 1-7
2.1 Concentrations of Constituents of Concern Which Will Result
in Banning Listed Wastes from Land Disposal [51 FR 1732] . . 2-5
3.1 Basis for Listing Wastes [50 FR 1978] 3-2
3.2 Physical and Chemical Characteristics of Some
CDDs and CDFs 3-6
3.3 Physical and Chemical Characteristics of Some
Chlorophenols and Chlorophenoxy Compounds 3-10
3.4 Listing of Dioxin Notifiers as of February 18, 1986 3-12
3.5 Constituents of Waste Code F020 3-15
3.6 Constituents of Waste Code F021 3-20
3.7 PCDD and PCDF Concentrations in Manufactured Products and
Chemical Intermediates 3-24
3.8 Characterization of Some Soils Contaminated with
Diozin Constituents ..... 3-28
4.1.1 Vertac Still Bottom Test Burn 4-12
4.1.2 Average Unit Costs for PCB Waste Destruction at Permitted
Stationary Rotary Kiln Facilities . 4-14
4.2.1 Soils Used in the EPA Mobile Incinerator During Preliminary
Testing of the Solids Feed System 4-23
vii
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TABLES (continued)
Number
Page
4.7.2 Typical Operating Data for PCB Tests (One Hour Runs) 4-70
4.7.3 PCB Test Results 4-71
4.8.1 PCB Combustion Tests in Sodium-Potassium-Chloride-Carbonate
Melts 4-77
4.8.2 Summary of Pilot-Scale Test Results 4-78
4.9.1 Composition of Feed Mixtures for Test Runs 4-84
4.9.2 Summary of Results: Oxidation of Organic Chlorides 4-85
4.9.3 Modar Treatment Costs for Organic Contaminated Aqueous
Wastes 4-87
5.1.1 Summary of Data Show Percent Removal of TCDD From
Contaminated Soils Using APEG Dechlorination Process . . . 5-7
5.1.2 Summary of Data Showing Percent Removal of TCDD From
Contaminated Soil at Denny Farm 5-7
5.1.3 Summary of Results of In-Situ Processing - All Soils
Initially at 2000 ppb 5-8
5.1.4 Results of Slurry Processing 5-8
5.1.5 Degradation of 2,3,7,8-TCDD Under Different Conditions
Using the CDP-Process 5-11
5.1.6 Preliminary Economic Analysis of In Situ and Slurry
Processes 5-13
5.2.1 Dissociation Energies for Some Chemical Bonds ... 5-16
5.2.2 Estimated Volumes and Concentrations of 2,3,7,8-TCDD
Produced by the Syntex-IT Photolytic Process 5-20
5.2.3 Design Specifications, Capital, and O&M Costs for 40,000
and 150,000 GPD ULTROX Treatment Plants 5-27
5.3.1 Solubilization of TCDD 5-33
5.4.1 Micro-organisms with Known Capability for Degrading
2,3, 7,8-Tetrachlorodibenzo-p-dioxin 5-37
xx
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SECTION 1
EXECUTIVE SUMMARY
INTRODUCTION
The 1984 Hazardous and Solid Waste Act Amendments to the Resource
Conservation and Recovery Act (RCRA) directed EPA to ban certain
dioxin-containing wastes from land disposal unless EPA determines that
restrictions on land disposal of these wastes are not needed to protect human
health and the environment. Congress, through the 1984 Amendments, fixed a
deadline of 24 months from the enactment of the Amendments for EPA to regulate
the land disposal of these identified wastes (with some exceptions). In the
event that the Agency has not issued regulations by that time (November 1986),
land disposal of all specified dioxin-containing waste streams automatically
will be banned.
An important aspect of the land disposal restrictions is the
identification and evaluation of alternative technologies that can be used to
treat the listed wastes in such a way as to meet proposed treatment levels
which EPA has determined are protective of human health and the environment.
If alternatives to land disposal are not available by November 1986, it may be
necessary to extend the deadline for the restrictions on land disposal. The
purpose of this document is to identify and evaluate alternative technologies
that remove and/or destroy dioxih and related compounds from listed dioxin
wastes in order to achieve constituent levels that allow the safe land
disposal of the treated residues.
SCOPE
A number of potential technologies exist for treating wastes containing
dioxin. Because many of the technologies are currently in early stages of
development, it is not possible to fully assess the effectiveness of these
1-1
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TABLE l.l. DIOXIN CONTAMINATED WASTES LISTED AS RCRA HAZARDOUS WASTES,
JANUARY 14, 1985, 50 FR 1978
EPA
hazardous
waste no.
Hazardous Waste from Nonspecific Source
Hazardous waste
Hazard
code
F020* Wastes** from the production or manufacturing use of (H)
tri- or tetrachlorophenol, or of intermediates
used to produce their derivatives.**
F021* Wastes** from the production or manufacturing use of (H)
pentachlorophenol (POP), or of intermediates used to
produce its derivatives.
F022* Wastes** from the manufacturing use of tetra-, penta-, (H)
or hexachlorobenzene under alkaline conditions.
F023* Wastes** from the production of materials on equipment (H)
previously used for the production or manufacturing
use of tri- or tetrachlorophenols.***
F026* Wastes** from the production of materials on equipment (H)
previously used for the manufacturing of tetra-,
penta-, or hexachlorobenzene under alkaline conditions.*
F027* Discarded unused formulations containing tri-, tetra-, (H)
or pentachlorophenol or discarded unused formulations
derived from these chlorophenols.****
F028 Residues resulting from the incineration or thermal (T)
treatment of soil contaminated with EPA hazardous
waste F020, F021, F022, F023, F026, and FU27.
*A proposed regulation [50 FR 37338] would make residues from the incineration
of these wastes (if the waste contained less than or equal to 10 ppm TCDD
prior to incineration) toxic instead of acute hazardous .
**Except wastewater and spent carbon from hydrogen chloride purification.
***This listing does not include wastes from the production of hexachlorophene
from highly purified 2,4,5-trichlorophenol.
****This listing does not include formulations containing hexachlorophene
synthesized from prepurified 2,4,5-trichlorophenol as the sole component.
(H) - Acute Hazardous Waste
(T) « Toxic Waste
1-3
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wastes requiring treatment at this tine are wastes such as still bottoms and
reactor residues that were generated in the past and remain to be treated.
The only process waste stream that is still being generated, and may continue
to be generated in the future, is from the manufacture of pentachlorophenol
(POP). However, by far the largest quantity of dioxin-bearing wastes that
have been identified are the contaminated soils such as those at Times Beach,
Missouri, and various other CERCLA sites throughout the country.
Table 1.2 shows estimated waste quantities for each of the waste codes.
Several items associated with the information in the table should be noted.
One is that no sources have yet been identified for waste codes F022 and
F026. Another is that waste code F028 is not included because it is expected
that residues from future incineration of contaminated soil will meet EPA
delisting requirements. Finally, contaminated soils are placed in a separate
category both because of their unique physical form relative to most process
wastes, and also because a large fraction of the contaminated soils are at
CERCLA sites whose wastes will not be affected by the RCRA land disposal
restrictions until November 1988.
The estimates of the quantities of wastes generated within each waste
category in Table 1.2 could have a significant impact on future treatment
practices. As shown in the table, there are more than 500,000 metric tons
(MT) of dioxin-contaminated soil that may require treatment. This quantity is
considerably greater than the estimated maximum 7500 HI of process wastes,
such as still bottoms currently requiring treatment and the estimated 2500 HI
of industrial process wastes that will be generated in future years.
Consequently, it would appear that treatment technologies capable of treating
soil wastes are of most importance at this time, particularly those
technologies, such as solvent extraction, that are capable of removing the
toxic constituents from the soil and thereby reducing the total volume of
waste requiring final detoxification/destruction.
TECHNOLOGIES FOR TREATING DIOXIN WASTES
As mentioned previously, a number of technologies for treating dioxin
waste are evaluated in this document. A summary of the status of these
technologies is provided in Table 1.3. Because studies have shown that dioxin
1-5
-------
TABLE 1.3. SUMMARY OF TREATMENT PROCESSES
Procea* name
Stetionery Sotary
Kiln Incineretion
Mobil* Sotary
Kiln Incineration
Liquid Injection
Incineration
Pluidiied-bed
Incineration
(Circulating ted
Combuator)
High Temperature
Fluid Hell
(Huber AES)
Applicable
weate atreama
Solid*, liquida. aludgea
Solid* , liquid*, aludge*
Liquida or aludge* with
viacoaity lea* than
10,000 aau
(I.e., pumpable)
Solid*, aludge*
Primarily for granular
contaminated aoila,
but may alao handle
Stage of
development
Several approved
and commercially
available unita for
PCBa; not yet uaed
for dioxlna
EPA mobile unit la
permitted to treat
dioxin waataa;
EH8CO unit ha* bean
demonstrated on PCS
waet*
Pull *c*l* land-
baaed unita permit-
ted for PCS*; only
ocean loclneretor*
have bandied dioxin
waatea
GA Technologlea
mobile circulating
bed combuator he*
a T8CA permit to
burn PCS* anywhere
ia the nation; not
teated yet on dioxin
Huber etationary
unit i* permitted
to do research on
Performance/
deatruction achieved Coat
Greater than aix nine* DU for 10.25 - |0.70/lb
PCBa; greater than five ninea for PCS aolida
DU demonatrated on dioxin at
combuation reeearch facility
Greater than aix nine* DU for HA*
dioxin by EPA unit; proceaa
realdual* dellated
Greater than aix ninea DU on *200 - 1500/ton
PCB waatee; ocean Inclneretora
only demonatrated three ninea
on dioxin containing herbicide
orang*
Greater than aix ninea DSE .60 - »320/ton
demon* treted by CA unit on for CA unit
PCB*
Pilot acal* mobile unit 1300 - i600/con
demonatrated greater then five
nine* DU on TCDD - contaminated
Keaidual*
genereted
Treated w**te material
(aah), acrubber vaatewater.
particulate from air
filtera. gaaeoue product*
of combuation
Same ea above.
Seme ea ebove, but e*h i*
u*uelly minor becauae
aolid feeda are not
treeted
Treated waate (aah), parti-
culataa from air filtera
Treated waite (olid*
perticulatea from baghouae,
liquida dioxin wa*t*e;
pilot *cale mobile
reactor ha* been
teated at aeveral
location* on dioxin
contaminated eoila
Infrared Incinerator Contaminated aoil*/*ludgee Pilot acal*. port-
(Shirco) «bl« uolt teated on
waat* containing
diosln; full acal*
unita heve been
uaed In other appli-
cation*; not yet
permitted for TCDD
aoil at Time* Beech (79 ppb
reduced to below detection)
Greater than aix ninea DSE on
TCDD-contaminated aoll
Treatment coata
are 1200 - t1,200
per ton
gaaeoua effluent (primarily
nitrogen)
Treated material (aah);
particulate* captured by
acrubber (aeparated from
acrubber water)
•Not available
(continued)
-------
6-1
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circulating bed variation), the plasma arc process, and the molten salt
process. The in situ vitrification process has not shown six nines UKE;
however, it is as much a stabilization process as it is a destruction
process. Therefore, the primary objective of this technology is to prevent
the leaching of dioxin or other toxic constituents from the treated soil;
whether the dioxin is driven out of the soil by volatilization or merely
contained within the vitrified material is a secondary concern (as long as
volatilized dioxin is captured and subsequently destroyed).
Nonthermal technologies evaluated include the following:
• Chemical dechlorination
• Ultraviolet (UV) photolysis
• Solvent extraction
• Biodegradation
• Stabilization/fixation
• Chemical degradation using ruthenium tetroxide
• Chemical degradation using chloroiodides
• Gamma ray radiolysis
Of the nonthermal technologies, those that have shown the most promise
and the highest level of recent investigation and testing are chemical
dechlorination and UV photolysis. Both of these technologies are currently
being field tested on dioxin-contaminated soil. As indicated in Table 1.3,
preliminary field data on the thermal desorption/UV photolysis process
indicate that dioxin was desorbed from soil to a level below I ppb, and then
destroyed efficiently using ultraviolet radiation. The chemical
dechlorination process has also demonstrated a reduction of TCUD in soil to
below 1 ppb, but only on a laboratory scale.
The other nonthermal processes have not shown as much promise with regard
to treating dioxin waste. Solvent extraction is a potentially useful
technology since it could, if successfully applied to soil treatment, reduce
the volume of the waste stream that requires final treatment/destruction by
several orders of magnitude. Unfortunately, this technology has not yet
l-ll
-------
associated waste streams are themselves subject to costly treatment
processes. Therefore, technologies such as solvent extraction or desorption,
which separate the toxic constituents .-from the waste matrix prior to final
treatment should receive further investigation.
Most of the emerging technologies are being designed for operation at the
waste source. This trend to portable or field-erected technologies reflects a
reaction to public opposition to the transport of dioxin waste from source to
waste treatment facilities, and should continue to be encouraged.
In addition, because of the large volume of soil contaminated by
relatively low concentrations of dioxin, it is also important to investigate
methods of in situ treatment. These methods would limit the handling of the
waste so that further dispersion of contaminated materials into the
environment is minimized. Most of the technologies in this category, such as
biodegradation, in situ vitrification, chemical dechlorination, and
stabilization in the near future have not yet been sufficiently demonstrated.
Use in the near future seems improbable without more intense development of
these technologies. Steps should be taken to encourage these developments.
The treatment of dioxin contaminated liquids and low viscosity sludges
does not appear to be as large a problem as is the treatment of contaminated
soils. This is primarily because the quantity of liquids and sludges is much
lower, and also because the liquid waste form generally calls for less
extensive handling and pretreatment. Technologies, such as plasma arc
pyrolysis and supercritical water oxidation, appear to be capable of treating
these wastes, and their development should be fostered, as should other
reasonable activities aimed at the development of emerging technologies.
1-13
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SECTION 2.0
REGULATIONS CONCERNING MANAGEMENT
OF LISTED DIOXIN WASTES
2.1 CURRENT REGULATION UNDER RCRA
Certain dioxin contaminated wastes originally regulated under the Toxic
Substance Control Act (TSCA), 40 CFR Part 775, were listed as hazardous wastes
under the Resource Conservation and Recovery Act (RCRA) on January 14, 1985,
50 FR 1978. The January 14, 1985 RCRA Anendments list as acute hazardous
wastes certain chlorinated dibenzo-p-dioxins, dibenzofurans, and phenols (and
their phenoxy derivatives). A complete listing was presented in Table I.I.
When the RCRA Amendment listing dioxin-contaminated wastes became effective on
July 15, 1985, duplicate listings of certain dioxins under RCRA and TSCA were
revoked.
The inclusion of these dioxin-contaminated wastes under the RCRA regula-
tions was mandated by the RCRA statutory amendments entitled the Hazardous and
Solid Waste Amendments of 1984 (HSWA), signed into law November 8, 1984 as
Public Law 98-616. HSWA, among other things, mandate a RCRA listing status
for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-contaminated wastes, stringent
technical requirements for land disposal facilities, an expanded definition of
land disposal, and various land disposal bans and restrictions.
HSWA state that in the case of any hazardous waste which is prohibited
from one or more methods of land disposal, the storage of such hazardous waste
is prohibited unless such storage is solely for the purpose of the
accumulation of such quantities of hazardous waste as are necessary to
facilitate its proper recovery, treatment, or disposal. In order for interim
storage of these wastes to be excluded from this prohibition, it must be
demonstrated that the storage is solely for the purposes of facilitating
proper recovery, treatment, or disposal. HSWA also specify a two year
(24 months) period during which EPA must decide whether or not to completely
2-1
-------
Pertinent regulatory provisions are summarized below.
2,3,7,8-TCDD-contaminated wastes resulting from the production or
manufacturing use of several chlorophenols and chlorobenzenes,
including contaminated soil, are added to the list of RCRA regulated
acute hazardous wastes (RCRA hazardous waste numbers F020, F021,
F022, F023, F026, F027, F028); RCRA regulated quantity for small
quantity generators is 1 kilogram of 2,3,7,8-TCDD-
contaminated material;
2,3,7,8-TCDD wastes may be disposed only in fully permitted RCRA
(Part B) land disposal facilities (interim status land disposal
facilities are not acceptable);
Interim status facilities that may be acceptable for the management
of 2,3,7,8-TCDD wastes include surface impoundments (for wastewater
sludge; managed pursuant to 40 CFR 264.231), enclosed waste piles
(pursuant to 40 CFR 264.250(c), tanks (pursuant to 40 CFR 264.200),
containers (pursuant to 40 CFR 264.175), incinerators (if certified
pursuant to 265.352), and thermal treatment units (if certified
pursuant to 265.383);
A waste management plan is required for all land disposal facilities
that submit Part B of their RCRA permit application. The waste
management plan will specifically address the means by which the
waste will be managed safely at the land disposal facility;
2,3,7,8-TCDD wastes may not be stored or disposed of in unlined
units;
Interim status incinerators and interim status thermal treatment
units are allowed to burn 2,3,7,8-TCDD wastes if they are
"certified" by the Assistant Administrator for the EPA Office of
Solid Waste and Emergency Response, pursuant to 40 CFK 265.352 and
.383, respectively as meeting 40 CFR Part 264, Subpart 0, RCRA
performance standards;
Incinerators and thermal treatment units that are used to burn
2,3,7,8-TCDD wastes must achieve a ORE of 99.9999 percent (i.e., six
nines DRE); and
Residue resulting from incineration or thermal treatment of
dioxin-containing soils (F028) must be, at a minimum, managed at a
RCRA interim status land disposal facility.
2-3
-------
TABLE 2.1. CONCENTRATIONS OF CONSTITUENTS OF CONCERN WHICH WILL RESULT
IN BANNING LISTED WASTES, FROM LAND DISPOSAL [51 FR 1732]
Constituent* Screening level (mg/1)
2,3,7,8-TCDD 4 x 10~9
Other TCDDs 4 x 10~7
2,3,7,8-tteCDDs 8 x 10~9
Other PeCDDs 8 x 10~7
2,3,7,8-HxCDDs I x 10~7
Other HxCDDs 1 x 10~5
2,3,7,8-TCDFs 4 x 10~8
Other TCDFs 4 x 10~6
2,3,7,8-PeCDFs 4 x 10~8
Other PeCDFs 4 x 10~8
2,3,7,8-HxCDFs 4 x 10~7
Other HxCDFs 4 x 10~5
2,4,5-Trichlorophenol 8.0
2,4,6,-Trichlorophenol 0.04
2,3,4,6-Tetrachlorophenol 2.0
Bentachlorophenol 1.0
r
^Definitions of abbreviations used above
TCDDs and TCDFs "All isomers of tetrachlordibenzo-p-dioxina and
-dibenzofurans respectively.
PeCDDs and PeCDFs " The pentachlorodibenzo-p-dioxins and -dibenzofurans.
HxCDDs and HxCDFs * The hexa-isomers.
2-5
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SECTION 3.0
CHARACTERIZATION AND QUANTIFICATION
OF LISTED DIOXIN WASTES
3.1 INTRODUCTION
The purpose of this section is to characterize the wastes described by
RCRA codes F020, F021, F022, F023, F026, and F027. These codes describe
wastes from the production and manufacturing use of tri-, tetra-, and
pentachlorophenols and from the manufacturing use of tetra-, penta-, and
hexachlorobenzenes under alkaline conditions and elevated temperatures. These
wastes include still bottoms, reactor residues, untreated brines, spent filter
aids, spent carbon adsorbents, and sludges resulting from wastewater
treatment. They also include wastes resulting from the production of
materials on equipment previously used for the production and manufacturing of
tri- and tetrachlorophenols, and formulations containing these chlorophenols
and their derivatives. Waste code F028 is a treatment residue from
incineration or thermal treatment of dioxin-containing soil to six nines DR£.
It is designated a toxic and not an acute hazardous waste, and therefore is
not addressed in this document. The untreated soils, however, that have been
contaminated by spills of wastes in codes F020, F021, F022, F023, F026 and
F027 are defined as hazardous (50 FR 28713) and are addressed.
As shown in Table 3.1, the basis for listing each of these wastes and for
banning them from land disposal is the expected or known presence of
significant quantities of tetra-, penta-, and hexachlorodibenzo-p-dioxins
(CDDs) and chlorinated dibenzofurans (CDFs). These compounds are among the
most potent animal carcinogens known and are potential human carcinogens in
addition to being extremely persistent in the environment. These wastes may
also contain significant concentrations of tri-, tetra-, and
pentachlorophenols and their chlorophenoxy derivatives, some of which are
potential human carcinogens (2,4,6-TCP) and/or are suspected of causing liver
and kidney damage (U.S. EPA, 1985).
3-1
-------
TABLE 3.1 (continued)
EPA code
Waste code description
Hazardous constituents for which listed
F023 Wastes (except wastewater and spent carbon
from hydrogen chloride purification) from
the production of materials on equipment
previously used for the production or manu-
facturing use (as a reactant, chemical in-
termediate, or component in a formulating
process) of tri-and tetrachlorophenols.
(This listing does not include wastes from
equipment used only for the production or
use of hexachlorophene from highly purified
2,4,5-trichlorophenol)•
F026 Wastes (except wastewater and spent carbon
from hydrogen chloride purification) from
the production of materials on equipment
previously used for the manufacturing use
(as a reactant, chemical intermediate, or
component in a formulating process) of
tetra-, penta-, or hexachlorobenzene under
alkaline conditions.
F027 Discarded formulations containing
tri-, tetra-, or pentachlorophenol or
discarded formulation containing hexa-
chlorophene synthesized from prepurified,
2,4,5-trichlorphenol as the sole component.
F028 Residues resulting from the incineration or
thermal treatment of soil contaminated with
EPA Hazardous Waste Nos. F020, F021, F022,
F023, F026, and F027.
Tetra-, and pentachlorodibenzo-p-dioxins;
tetra- and pentachlorodibenzofurans; tri-
and tetra-chlorophenols and their
chlorophenoxy derivative acids, esters,
ethers, amines, and other salts.
Tetra-, penta-, and hexachlorodibenzo-p-
dioxins; tetra-, penta-, and hexachlorodi-
benzofurans.
Tetra-, penta-, and hexachlorobibenzo-p-
dioxins; tetra-, penta-, and hexachlorodi-
benzofurans; tri-, tetra-, and pentachloro-
phenols and their chlorophenoxy derivative
acids, esters, ethers, amines, and other
salts.
Tetra-, penta-, and hexachlorodibenzo-p-
dioxins; tetra-, penta-, and hexachlorodiben-
zofurans; tri, tetra-, and pentachlorophenols
and their chlorophenoxy derivative acids,
esters, ethers, amines, and other salts.
-------
(•) Dibenzo-p-Dioxin
(a) Dibenzofuran
Figure 3.1. Structure of (a) Dibenzo-p-Dioxin and (b) Dibenxofuran
Source: Environment Canada, 1985
3-5
-------
• low vapor pressure;
• absorption of ultraviolet radiation; and
• low rate of biodegradation.
*
PCDDs are characterized by low polarization which results in a very low
water solubility, but a much higher solubility in organic solvents. The water
solubility of 2,3,7,8-TCDD has been measured by a number of investigators.
Recently derived estimates have been in the range of 7 to 20 parts per
trillion. In contrast, the solubility of TCDD in organic solvents such as
benzene, xylene, and toluene ranges from 500 to 1,800 ppm. This results in a
log octanol/water partition coefficient of up to nine. Consequently, in the
environment TCDD is not generally found at high concentrations in aqueous
media. Instead, it is bound to the organic matter in soil where it may remain
for long periods of time. The half-life of TCDD in soil has been estimated to
range between 1.5 and 10 years (U.S. EPA, 1985), but the results of one recent
study indicated virtually zero degradation of TCDD after being in the soil for
twelve years. In addition, the TCDD had only moved about 10 centimeters over
this period of time (Freeman & Schroy, 1986).
Another property of TCDD is that it absorbs ultraviolet light strongly
with a wavelength of maximum absorption lying within the sunlight region
(above 290 nm). As a result, TCDD has been shown to degrade significantly
when exposed to light of this wavelength in the presence of a hydrogen donor
such as hexane or some other organic solvent. Tests have shown that when a
hydrogen doner is not present, degradation of TCDD is negligible (Crosby,
D. G., 1985). Photolytic degradation was applied to 4,300 gallons of still
bottoms containing 343 ppm of 2,3,7,8-TCDD. The dioxin was first extracted
from the still bottoms using hexane, and then the extract was irradiated with
ultraviolet light; 99.9 percent destruction of TCDD was achieved. This
process will be described in more detail in Section 5.
One of the most important properties of TCDD with respect to treatment is
that it is destroyed at temperatures between 1200 and 1400°C (Shaub and Tsang,
1982). When chlorinated compounds are incinerated at lower temperatures,
however, dioxins may be formed in large quantities. The heat of combustion of
PCDD is 2.81 kilocalories per gram which is greater than the heat of
combustion of compounds such as I,I,1-trichloroethane and pentachlorophenol.
3-7
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Chlorophenola and Chlorophenoxy Compounds
In general these compounds are water soluble, and in wastes they
concentrate in the aqueous phase where they are biodegradable by adapted
microorganisms (U.S. EPA, 1985). The biodegradation half-life of 2,4,5-T and
Silvex in water is expected to be one to three weeks. The same compounds have
a similar half-life due to biodegradation in soils. 2,4,5-TCP, however, has
been shown to be persistent in some soils. In one case, where the initial
concentration of 2,4,5-TCP in soil was 5000 ppm, the concentration after three
years was still 1 to 20 ppm (Lautzenheiser, 1980).
Other properties of these compounds include relatively low volatility,
ability to be adsorped by organic matter such as activated carbon, and
susceptibility to photolytic degradation (U.S. EPA, 1985; Lautzenheiser,
1980). Chemical and physical characteristics of these compounds are listed in
Table 3-3.
3.3 WASTE SOURCES, QUANTITIES, AND COMPOSITION
3.3.1 Sources of Data
The primary source of data utilized for waste quantity estimates was a
report prepared by Technical Resources, Inc. (TRI), entitled, "Analysis of
Technical Information to Support RCRA rules for Dioxins - Containing Waste
Streams". This report evaluated previous estimates of waste quantities made
by Radian (Radian, 1984), and determined that they reflected past practices.
TRI presented revised waste generation quantities based on more current
information on manufacturing processes obtained by talking to industry
contacts. Their estimates appear to be the best available at this time;
however, where additional information was available, changes have been made to
their estimates.
There are several other sources of data which may be used in the future
to obtain better estimates of the quantity of vaste containing dioxin. One of
these is EPA's Dioxin Strategy. Tiers one, two and three of the Dioxin
Strategy encompass sites where 2,4,5-TCP and its pesticidal derivatives were
produced or formulated and also sites where wastes from these processes were
disposed. Close to 100 potential sites were identified in Tiers I and 2
3-9
-------
(Radian, 1984); a report will be issued in the near future containing
information related to the extent of contamination at these sites. The
information in this report will hopefully contain data which will allow for a
better estimate of waste quantities and characteristics, particularly for
those sites where waste was disposed (Korb, 1986).
Another potential but unused source of data is RCRA Biennial Reports.
These reports are filed biennially by hazardous waste treatment, storage and
disposal facilities. EPA has indicated that the data from the 1983 reports
are not very accurate both because of a poor response rate, and also because
data reported to states were not carefully verified prior to sending data
summaries to EPA headquarters (Stoll, 1986). In addition, at the time of the
1983 report, the dioxin waste codes (F020-F028) had not yet been developed.
Consequently, the 1983 report only contained data concerning the "U" waste
codes for tri-, and tetra-, and pentachlorophenol and their pesticide
derivatives 2,4,5-T and Silvex. These waste codes have now been replaced by
F027. The 1985 Biennial Reports will contain data on the quantities of waste
in codes F020-F028 that were treated, stored or disposed in 1985. These data
should be available in the fall of 1986. Whether these data will be better
than the data from the 1983 Biennial Reports is unknown at this time.
Finally, facilities that handle (generate, store, treat, or dispose)
wastes covered under the dioxin listing rule were required to notify EPA by
April 15, 1985. Information contained in the notifications does not at this
time include data on the quantities of waste generated or stored, but it does
indicate which waste codes the facility handles, and it also includes data to
indicate the waste treatment and storage capacity at these facilities. TRI
utilized this information to estimate the quantities of F027 waste that will
require treatment.
A recent listing of the dioxin waste notifiers is presented in
Table 3.4. This listing is updated monthly as new facilities notify, or as
facilities that do not belong on the list are deleted. It is expected that
information regarding the quantities of wastes handled by these facilities
will be assembled in the future.
3-11
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3.3.2 Waste Code F020
Sources of Waste—
This waste code includes wastes from the production and manufacturing of
*
tri- or tetrachlorophenols or intermediates used to produce their
derivatives. The major derivatives include phenoxy compounds such as
2,4,5,-trichlorophenoxyacetic acid (2,4,5,-T), 2-(2,4,5-trichlorophenoxy)
propionic acid (Silvex), and hexachlorophene.
The manufacture of 2,4,5-TCP is accomplished by the alkaline hydrolysis
of tetrachlorobenzene. The primary wastes from the process include
distillation bottoms from solvent recovery, spent filter aids, and reactor
bottoms. These wastes, in addition to the product itself, will be
contaminated with CODs, CDFs and chlorophenols. The amount of CDDs formed in
the process is dependent upon reaction temperature, which in turn is dependent
upon the solvent used (methanol, ethanol, ethylene giycol, toluene or
isomyl/amyl alcohols). When methanol or water are used as the solvent, the
process operates at around 220-300°C, a temperature at which lab experiments
have shown the formation of 1.6 g TCDD per kg of 2,4,5-TCP. Using ethylene
giycol the process operates at lower temperatures and CDD formation should be
lower (U.S. EPA, 1985).
2,4,6-trichlorophenol and 2,3,4,6-tetrachlorophenol are most efficiently
produced by the chlorination of phenol. la this process more 1,3,6,8-TCDD
than 2,3,7,8-TCDD is formed. These products also contain up to 50 ppm of CDFs.
The manufacture of 2,4,5-T and other phenoxy compounds utilize 2,4,5-TCP
as one of their starting materials. Since TCDD contaminates 2,4,5-TCP, and
may also be generated in the formation of the phenoxy compound itself, it is
expected to be present in both the product and the wastes from its
manufacture. Phenoxy herbicides such a* 2,4,5-T and Silvex are synthesized oy
reacting the appropriate chlorophenol with a haloalkanoic acid under alkaline
reflux conditions. These conditions are conducive to the formation of CDDs
and CDFs. Careful control of reaction time, temperature,and pH are said to
have an effect in reducing the formation of TCDDs. Wastes from the process
include caustic scrubber water, spent filter aide and/or carbon adsorbent, and
distillation bottoms from solvent recovery. Solvents used are similar to
those used in the production of 2,4,5-TCP. Formerly methanol was used, and
more recently a mixture of ethylene giycol and toluene or xylene was used.
-------
TABLE 3.5. CONSTITUENTS OF WASTE CODE F020
u>
I
Source
Other
2.3.7.8-TCDD TCDO. CDDS CDF*
Other Pouible
Constituent*
Reference*
Herbicide Manufacture
(•tilt botto**, and
reactor icaidue*
fro* the Mnufacture
of 2,4.5-T. 2,*,5-TCP
•nd He*actlorophene)
Non-Aqueou* Fh**e
Le*ch*te (fro*
di*poaal of w**te
fro* Manufacture of
2,4,5-T and phenoxy
herbicide* - Love
Canal. Hyde Perk)
60-1290 ppm
0.6-350 pp*
Filter Aid*
in 2,4,5-TCP
•anufacture
Filter Cake
fro* Heiechlorophene
•anufactur*
Spent Carbon
fro* treet*ent of
•queou* leachate.
0.2-20.2 pp*
0.008-300 pp*
8-2000 ppb
untreated wa*te,
0.004-0.017 ppb;
trected vatte.
0.010 ppb
• Hethanol
Toluene
Xylene
ethylene glycol
eth*nol
• 2,4,5-TCP
e trichloro*ni*ole*
(•ethoiyphenyl*)
• tetrachloro-
bensen*
• *i*il*r to w**te*
described *bove
plu*:
• heevy *et*l*
- *nti*ony
- *r*enic
- lead
- nercury
- alu*inu*
- chro*im
• fluoroorg*nic*
• bro*oorg*nic*
• phoaphide*
a culfide*
• PCS
a lnorg»nic Solid*
a chlorophenol*
• Inorgcnic Solid*
a chlorophenol* or
organic colvent*
• Spent Carbon
• chlorphenol* end
other orginici
30-50Z
1-101
SSZ
0-0.5Z
100-lOOOppm
de* Holier*, 1985;
R*di*n, 1984;
U.S. EPA, 198)
U.S. EPA, 198)
99. SZ
0-0.5Z
99.5Z
O.OSZ
99.5Z
O.OSZ
U.S. EPA, 1985
U.S. EPA, 1985
U.S. EPA, 1985
-------
spent carbon from the treatment of aqueous phase leachate from the Love Canal
Landfill. The TRI report did not include an estimate of the quantity of spent
carbon from treatment of aqueous phase leachate at the Hyde Park Landfill.
EPA Region II personnel have indicated that there are currently several
dumpsters of spent carbon at the site that Calgon (the manufacturer of the
carbon) will not accept for regeneration because of possible dioxin
contamination. Aqueous phase leachate is still being generated at a rate of
approximately 5000 gallons per day, so spent carbon will also continue to oe
generated and require treatment (Gianti, 1986).
, In addition to the non-aqueous phase leachate that is currently stored in
lagoons at Hyde Park, an additional 40 to 200 gallons per day are continuing
to be collected. At an average rate of 120 gallons per day, 200 MT would be
collected in one year. The period of time over which NAPL will continue to be
generated is not known (Gianti, 1986).
In addition to these major sources of waste, there are probably other
smaller sites where 2,4,5-TCP and derivatives were manufactured or formulated
in the past and wastes are currently stored. Possible locations of these
sites have been and are being identified through EPA1s Dioxin Strategy and
also through the provision that all potential handlers of dioxin wastes notify
EPA of their activities. Data on the quantity of wastes at these "other"
sites, however, are not currently available. TRI estimated that the quantity
of F020 waste at these miscellaneous sites is 500 MT.
3.3.3 Waste Code F021
Sources of Waste—
This waste code encompasses wastes from the production and manufacturing
of pentachlorophenol. Pentachlorophenol (PGP) and its sodium salt have
various uses a* fungicides and biocides with the majority (80 percent) being
used as a wood preservative. Since all non-wood uses of PGP will be banned as
a result of a notice of intent to cancel made by EPA on January 8, 1986
(Chemical Regulation Reporter, 1/10/86), it is expected that all future uses
will be as a wood preservative.
The manufacture of pentachlorophenol can be accomplished either by the
chlorination of phenol or by the alkaline hydrolysis of hexachlorobenzene. In
the United States, the former method is used. The chlorination usually
3-17
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formation of PCDDs and PCDFs (des Rosters, 1985). The number of sices
containing these sludges may exceed 100; however, no estimates of the quantity
of sludges has been made. In addition, 23 damage incidents related to wood
treating operations using PCP were included in the Listing Background
Document. These damage incidents include cases where sludges and wastewaters
were stored onsite and contaminated soil and water. This waste stream is
being included in this discussion due to its possible listing as a "dioxin
waste" to be banned from land disposal.
Waste Characteristics—
As mentioned above, the manufacture of PCP does not currently generate a
waste stream containing CDDs. In the future, however, PCP will have to be
purified to reduce HCDD concentrations from 15 ppm to 1 ppm. Radian estimated
the composition of a waste stream generated as a result of the purification of
PCP by distillation (Radian, 1984). This waste stream would consist primarily
of organic solids (nonvolatile), various chlorinated phenols and organic
solvents as indicated in Table 3.6. In addition, a small fraction of the
waste would consist of residual catalyst (aluminum chloride), and total CDDs
could reach 2,000 ppm. Future purification of PCP will probably not be by
distillation, but instead by a solvent extraction and crystallization
process. The wastes from this process are assumed to be similar to those
generated by distillation (TRI.1985).
Waste from wood treatment facilities is expected to contain a large
variety of constituents. The exact composition of the waste will vary from
facility to facility, but in all cases will be a sludge with varying
concentrations of water, chlorophenols, and creosote. Organometallic
compounds such as copper and zinc naphthalenates and arsenicals are also
expected to be potential constituents, in addition to PCBs and waste
solvents. The source of CDDs and CDFs in these wastes would be from the
inherent contamination of PCP with these compounds. Higher concentrations may
be present if waste pits and lagoons containing these wastes were torched to
reduce volume.
3-19
-------
Waste Quantities—
The only current manufacturer of PCP is Vulcan Materials Company.
Previous manufactures include Dow, which ceased production in 1980, and
Reichhold Chemicals, Inc. which ceased production in 1985 (TRI, 1985). TRI
estimated that Vulcan would fill the cArrent U.S. demand for PCP of 15,000 hi
per year. If this is the case, and if purification results in a waste stream
of 5 percent of the end product, the quantity of waste generated through
purification will be 750 MT per year.
Wastes from formulation of PCP are not expected to be generated in the
future since all PCP is expected to be sold directly to wood preservers.
Previous to the ban of non-wood uses of PCP, however, 20 percent of the PCP
was formulated into products for herbicidal, antimicrobial, and disinfectant
use (Chemical Regulation Reporter, 1/10/86). These uses are assumed to have
resulted in the generation of 350 MT per year of scrubber water sludges
contaminated with PCP and HCDO. Three hundred fifty MT are estimated for the
past years (1985) formulation activities, and another 350 MT for the current
years activities. Therefore, as indicated previously in Table 1.2, 700 MT of
waste code F021 presently require treatment.
3.3.4 Waste Code F022
The Radian Report (Radian, 1984) states that there are no known
commercial activities with the processes encompassed by this waste code. The
compound, 2,4,5-trichlorophenol, was manufactured by the alkaline hydrolysis
of tetrachlorobenzene which would subject its wastes to inclusion in this
waste code, in addition to waste code F020. Since 2,4,5-TCP is not being
manufactured at this time, no wastes are currently being generated.
Potentially generated wastes, and wastes generated by this process in the past
are discussed previously under waste code F020.
3.3.5 Waste Code F023
Sources of Waste—
Production trains are often used for the production of chemicals whose
manufacture necessitates the use of similar process equipment. In the
manufacture of chemicals on a production train previously contaminated with
3-21
-------
currently using contaminated equipment and generating contaminated wastes. In
addition, they assumed that current production levels are equal to the
greatest past production levels. These assumptions would seemingly lead to an
upper bound estimate of the quantity of F023 waste generated. The actual
«
quantity probably lies between TRI's estimate of zero and Radians estimate of
573 MT per year.
3.3.6 Waste Code F026
The only manufacturing process that involves the manufacturing use of
tetra-, penta-, or hexachlorobenzenes is the manufacture of
2,4,5-Trichlorophenol. Aa mentioned above, the manufacture of 2,4,5-TCP
involves the alkaline hydrolysis of tetrachlorobenzene. Wastes from the
production of materials on equipment previously used to manufacture 2,4,5-TCP,
however, is regulated under waste code F023. Consequently there should oe no
F026 waste generated..
3.3.7 Waste Code F027
Sources of Waste—
This waste code encompasses discarded, unused formulations of tri-,
tetra-, and pentachlorophenols and their derivatives. These wastes arise
either because the product is off specification, the product was manufactured
but then its use was banned, or an excess amount was produced or acquired.
Because most of these compounds are no longer being manufactured, these wastes
are not currently being generated. The exception to this, as mentioned above,
is pentachlorophenol which is still manufactured, and so wastes from unused
formulations may continue to be generated. For the other compounds of concern
unused formulations which have been generated in past years may still lie in
storage and eventually require final destruction/disposal.
Waste Characteristics--
Measured concentrations of CDDs and CDFs in the products of concern are
presented in Table 3.7. As indicated by the data in this table, the
concentration of CDDs in these products can range from non-detectable levels
3-23
-------
up co hundreds of ppm. The actual concentration will vary from batch to
batch, and compound to compound. In addition, the products may have contained
higher concentrations of CDOs in the past than they have more recently. For
example, the mean concentrations of 2,3*7,8-TCDD in Agent Orange and Agent
Purple (both mixtures of 2,4,5-T and 2,4-D) in the 1960s were 1.98 and 32.8
ppm respectively (Young, 1983) while it was claimed that those prepared in the
1970s contained less than 0.1 ppm (Rappe, 1979). Despite this claim there may
still remain quantities of waste in storage with substantial levels of TCUO.
For example, the Tennessee Valley Authority (TVA) currently has 21 drums of
herbicide orange, one of which contains 5.6 ppm of 2,3,7,8-TCDD (TRI, 19U3).
The only F027 waste being generated on an ongoing basis would be unused
pentachlorophenol. Because of the consent decree requiring POP manufacturers
to reduce the concentration of HCDO in their product from 15 ppm to 1 ppm,
this waste will be of less concern than it has been in the past, since the
majority of the HCDD will be incorporated in the purification wastes.
The physical forms of these wastes will vary from case to case.
Pentachlorophenol is commonly applied to wood as a 5 percent suspension in
fuel oil (sometimes blended with creosote) or dissolved in an organic solvent
(Chemical Products Synopsis, 1983). The other products are generally marketed
as emulsifiable concentrates. These concentrates are prepared by dissolving
the active ingredient (15-80 percent) and a surface active agent (less than
5 percent) in a water emulsifiable organic solvent. The surface active
emulsifiers are generally polyethylene and polypropylene glycols, calcium
sulfonates or various soaps (Sitig, 1980).
Waste Quantities—
TRI estimated the quantity of waste code F027 in storage to be 1,000 MT
per year. This estimate was based on a review of data contained in the Dioxin
Waste Notifications. They estimated that the amount of waste generated that
would place a demand on treatment capacity was equivalent to the storage
capacity at facilities notifying EPA that they were handling waste code F027.
Their estimate does not include facilities which reported capacity for waste
treatment within the plant site because the waste generated at these
facilities would not place a demand on offsite treatment.
3-25
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Large quantities of contaminated soils and sediments also exist in New
York State. Two landfills, Hyde Park and Love Canal, were used for the
disposal of organic solvents and wastes from the production of chlorophenols
and phenoxy herbicides. The Hyde Park landfill is estimated to contain
«
approximately 120 kg of TCDD; leakage of wastes from these landfills has
resulted in the contamination of surrounding soils and sediments. It is
believed that there are 55,000 cu yds of stream bed sediments contaminated
with an average of 70 ppb of TCDD (USEPA, 1985).
Waste Characteristics—
Waste soils, sediments and other solid materials that have been
contaminated with dioxin may have varied compositions and concentrations of
dioxin. As indicated in Table 3.8 concentrations of TCDD in soils and other
solids range from nondetectable (ND) to greater than 26 ppm. The contaminated
materials at some of the sites include not only granular materials such as
soils and sand, but also asphalt, vegetation, rocks and gravel. These
materials may require special procedures to remove and/or destroy the TCDD.
Incinerators many times require the feed material to be of a certain size and
consistency. Consequently, some sort of pretreatment to reduce size and
produce a more uniform feed may be necessary for the treatment of these wastes.
One of the most significant characteristics of TCDD on soils is its very
high soil/water partition coefficient. As shown in Table 3.2 the log of the
partition coefficient can be as high as seven. The conclusions of a recent
study indicate that the most important factor affecting both the concentration
of TCDD in soils, and its partitioning between soil and water is the presence
of other organic* in the soil. The data indicated that in soils with higher
concentrations of solvent-extractable organics (particularly halogenated
semivolatiles) the TCDD concentrations in water extracts were greater. They
further suggested that it is other organic contaminants in the wastes and not
the total organic carbon and clay content of soils that affects the mobility
of TCDD (Jackson, D. R. et al, 1985). This would mean that in cases where
wastes from the manufacture of chlorophenols or chloropnenoxy herbicides were
disposed or leaked into soil media along with other organic wastes, TCDD may
be much more mobile than would be normally expected. In cases where
chlorophenols and organic solvents are not present in the wastes, the TCDD may
be much more strongly bound to the soil, and much more difficult to desorb.
3-27
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Waste Quantities—
It has been estimated that there are 500,000 HI of dioxin-contaminated
soils in Missouri, 160,000 MT at Times Beach alone (Radian, 1984). Radian
made a rough estimate of the total quantity of dioxin-contaminated soil in the
U.S. by assuming an average site size (5 acres with a 1.5 ft. depth) and
multiplying this by the number of tier 1, 2, and 3 sites identified in the
Dioxin Strategy. Their result was 2.3 million MT. Because of the
uncertainties in making an estimate such as this, 500,000 MT was used as the
minimum quantity of dioxin-contaminated soils currently requiring treatment in
the United States. This is the number that is presented in Table 1.2. It
will be possible to make a more accurate estimate of the quantity of
contaminated soil after the sites identified in the Dioxin Strategy are better
characterized.
Wastes which are of concern for this document are those containing an
extractable TCDD or TCDF concentration of greater than 1 ppt>. It is possible
that much of the contaminated soil will contain strongly adsorbed TCOD, and so
will not require treatment with respect to the land disposal ban.
3-29
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Freeman, R.A. and J.M. Schroy. Modeling of the Transport of 2,3,7,8-TCDD
and Other Low Volatility Chemicals in Soils Environmental Progress,
5 (1), 1986.
GCA Technology Division. Assessment of Treatment Alternatives for Wastes
Containing Helogenated Organics. U.S. EPA Contract No. 68-01-6871.
October, 1984.
Gianti, S. U.S. EPA, Region II. Telecon with H. Arienti, GCA Technology
Division. March 6, 1986.
ICF, Incorporated. The RCRA Risk/Cost Analysis Model Phase III Report.
Submitted to U.S. EPA Office of Solid Waste, Economic Analysis Branch.
March 1, 1984.
Industrial Economics, Inc. Regulatory Analysis of Proposed Restrictions
on Land Disposal of Certain Dioxin-Containing Wastes. Draft Final report
prepared for EPA, Office of Solid Waste. January, 1986.
IT Enviroscience, Inc. Study of Potentially Hazardous Waste Streams for
the Industrial Organic Chemical Manufacturing Industry, 1982.
Jackson, D.R. et. al. Leaching Potential of 2,3,7,8-TCDD in Contaminated
Soils. In proceedings of the Eleventh Annual Research Symposium on Land
Disposal of Hazardous Waste. EPA/600/9-8S/013 April 1985.
Junk, G.A. and J.J. Richard. 1981. Dioxins Mot Detected in Effluents
from Coal/Refuse Combustion. Chemosphere 10:1237-1241.
Korb, Barry. U.S. EPA. Telecon with M. Arienti, GCA Technology
Division. February 10, 1986.
Lautzenheiser, J.G. et. al. Non Aquatic Fate and Environmental Bruden of
2,4,5-T, 2,4,5-TP and 2,4,5-TCP. Prepared for U. S. EPA Contract No.
68-01-3867. September, 1980.
Marple, L. et. al. Water Solubility of 2,3,7,8-Tetrachlorodibenzo-p-
dioxin. Environmental Science and Technology. 20 (2) 1986.
Mill, T. SRI International, Menlo Park, CA
Radian Corporation. Assessment of Treatment Practices For Proposed
Hazardous Waste - Listings F020, F021, F022, F023, F026, F027, and F028.
EPA Contract No. 68-02-3148. September, 1984.
3-31
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SECTION 4
THERMAL TECHNOLOGIES FOR LISTED DIOXIN WASTES
In this report, thermal technologies include incineration, pyro lysis and
other processes in which heat is the major agent of destruction. As mentioned
in Section 3, laboratory studies have shown that CDDs break down rapidly when
subjected to temperatures above 1,200°C. As a result, high temperature
incineration and other thermal methods have received much attention with
regard to treatment of waste containing CDDs. This attention has led to the
development by EPA of a mobile incineration system designed specifically for
research on wastes containing dioxin and other toxic substances. This mobile
incinerator has demonstrated greater than six nines (99.9999 percent)
destruction and removal efficiency (DRE) of wastes containing CDDs, and has
led EPA to propose in their January 14, 1986 ruling on land disposal of waste
containing dioxins (FR, Vol. 51, No. 9) that incineration (or an equivalent
thermal technology) be used as the treatment technology for these wastes.
Incineration and other thermal treatment of RCRA-listed dioxin wastes
(codes F020, F021, F022, F023, F026, F027) must be done in accordance with the
criteria specified under 40 CFR Parts 264.343 and 265.362 in the dioxin
listing rule. These criteria specify that processes burning these wastes must
achieve a DRE of 99.9999 percent for each principal organic hazardous
constituent (POHC) designated in its permit. DRE is determined from the
following equation:
(W. - W )
DRB . « 100
in
where: W^a • macs feed rate of one POHC in
the waste stream feeding the incinerator; and
Woug • mass emission rate of the same POHC
present in exhaust emissions prior to release to
the atmosphere.
4-1
-------
This section includes subsections on a variety of thermal technologies.
Methods of incineration include:
Stationary Rotary Kiln *
Mobile Rotary Kiln
Liquid Injection
Fluidized Bed
Infrared
Other thermal destruction technologies include:
High Temperature Fluid Wall
Plasma Arc
Molten Salt
In Situ Vitrification
Supercritical Water Oxidation
Each subsection contains a process description, an evaluation of the
performance of the technology with regard to chlorinated dibenzo-p-dioxins
(CDDs) or similar compounds, an assessment of treatment costs, and a
discussion of the status of the technology. Not all of these units have been
tested using dioxin waste, but most of them have at least been tested using
PCS waste; in these cases, the FOB data have been presented as evidence of
their performance.
4.1 STATIONARY ROTARY KILN INCINERATION
Several commercial rotary kilns have been permitted to burn FOB wastes.
In so doing they have demonstrated six nines ORE for PCBs, and therefore have
the potential to burn dioxin waste*. These units are: the Rollins
incinerator in Deer Park, Texas; the SCA incinerator in Chicago, Illinois; and
the ENSCO incinerator in El Dorado, Arkansas. None of these units has been
demonstrated using dioxin wastes; however, the EPA Combustion Research
Facility in Jefferson, Arkansas, which operates a rotary kiln incinerator,
recently conducted test burns of dioxin wastes. Even though this is not a
commercial incineration facility, the data that were generated by the dioxin
burns are included to indicate the performance of a rotary kiln.
4-3
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Rollins (Rollins, 1985; M. M. Dillon, 1983; Gregory, 1981)--
The configuration of the Rollins stationary incinerator is shown in
Figure 4.1.1. Solids or sludges are conveyed to the rotary kiln in fiber
drums or 55 gallon metal drums. Certain solids (such as capacitors,) need to
be preshredded prior to being fed into the kiln. Liquid wastes can be fed
directly into the afterburner section. The liquids are atomized using
compressed air, which produces a rotary action in the combustion zone.
The combustor is a Loddby furnace measuring 1.6m diameter by 4.9m long.
The fterburner zone measures 4 x 4.3 x 10.6m. Natural gas and/or No. 2 fuel
oil are used as ignition fuel and also as a supplementary fuel if necessary.
Combustor temperatures can reach 1500°C, and afterburner temperatures average
1300°C. Residence times in the afterburner range from 2 to 3 seconds. Kiln
residence times vary widely according to the form of the waste, with residence
time being a function of design, solids content and viscosity. Combustion
gases from the afterburner pass through a combination venturi
scrubber/absorption tower system in which particulates and acid gases are
removed from the gas stream. A fraction of the scrubbing water is dosed with
lime and returned upstream of the venturi throat to increase scrubbing
efficiency. Induced draft fans are used to drive the scrubber gas stream to
the atmosphere.
ENSCO (M. M. Dillon, 1983; McCormick, 1986)—
A schematic of the ENSCO incineration facility is shown in Figure 4.1.2.
Drummed wastes are fed to an enclosed shredder where solids drop into a hopper
and are conveyed by an auger into the rotary kiln. Liquid wastes are mixed
with the shredded solids and conveyed to the kiln or injected directly into
the combustion chamber. The air in the enclosed shredder is drawn by a fan
into the rotary kiln.
The rotary kiln measures 2.1m in diameter by 10.4m long and is angled
slightly so that the solid residue flows by gravity to the ash drop. Flue
gases from the kiln are ducted to the 85 cubic meter combustion chamber where
fuel (often an organic waste) is burned to create a high temperature zone
(outlet temperature 1250°C). This afterburner, which possesses an outlet
4-5
-------
Sludge, semi-solids,
contaminated dirt
Capacitors, ballasts, drums, etc.
Totally enclosed shredder
Liquid organic waste—y
Liquid aqueous waste -v\
Combustion air
Liquid aqueous waste
i— Liquid organic wastes (fuel)
Rotary kiln
2.1 * 10.4 m
Ferrous metal
recovery —
Ash
diop
Combustion air 4-
Exhaust air
84.9 m3
Combustion
chamber
Chemical encipsubtion
of scrubber sludge and
ash for landfill
Deep well injection
of brine
Sludge lagoon
I
84.9 m3 Secondary
combustion
I chamber
Make-up
water
1
Scrubber
Z
Stack
, Oemister
pad
Lime mixing
I
Stack drain
Figure 4.1.2. Schematic of ENSCO stationary incinerator [M.M. Dillon, 1983].
-------
4.1.2 Technology Performance Evaluation
As discussed in the previous subsection, three commercial-scale
•4
stationary rotary kiln incinerators have demonstrated six nines ORE (99.9999%)
for PCBs and are permitted to burn PCBs. Trial burns of dioxin wastes have
not been conducted at any of the commerical-scale stationary rotary kiln
incinerators due to strong public opposition* However, trial burns of
dioxin-containing wastes have been performed using the stationary rotary kiln
incinerator at the U.S. EPA Combustion Research Facility (CRF) in Jefferson,
Arkansas.
The CRF is a 3100 sq.ft. permitted experimental facility built for the
purpose of conducting pilot scale incineration burns and evaluating whether
incineration is an effective treatment/disposal option for various types of
hazardous waste. During September 1985, trial burns were conducted at the CRF
using dioxin-containing toluene still bottoms (Ross, et al., 1986). These
were generated by the Vertac Chemical Company in Jacksonville, Arkansas and
stored there pending an EPA decision on appropriate treatment/disposal.
The CRF contains two pilot-scale incinerators and associated waste
handling, emission control, process control,, and safety equipment
(Games, 1984). Additionally, onsite laboratory facilities are available to
characterize the feed material and process performance samples. As shown in
Figure 4.1.3, the main components of the CRF incineration system include a
standard rotary kiln incinerator, an afterburner and a conventional air
pollution control system (Games, 1984; Ross, et al., 1986;
Ross, et al., 1984). Waste fed into the kiln flows countercurrent to the
primary burner (concurrent configuration is also possible). The
monitoring/control equipment for the kiln includes a propane meter, a pitot
tube to monitor primary combustion air, a shielded thermocouple to control
temperature, and monitoring equipment for combustion gas composition and flow
rate. Organic components are determined by extractive sampling through a
heat-traced sampling line and a liquid impinger (from EPA Method 5) or a
volatile organic sampling train (VOST) (Games, 1984; Ross, et al., 1986;
Ross, et al., 1984).
4-9
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Following combustion in the kiln, the combustion gases are directed
through a refractory-lined transfer duct to the afterburner. A shielded
thermocouple is used to control temperature in the afterburner. Surface
«
temperature, exit gas temperature and combustion gas composition and flow rate
are monitored. Exhaust gases are cleaned in the air pollution control system
which consists of a variable throat venturi scrubber, a fiberglass reinforced
polyester wetted elbow, a packed tower caustic scrubber, and an induced draft
fan (Carnes, 1984; Ross, et al., 1986; Ross, et al., 1984).
A total of four trial burns were performed in 1985 between September 4th
and September 21st. These included a blank burn to establish .background
emission levels, a short-duration (4 hrs.) burn to establish feed capabilities
and to test the sampling protocol, and two full waste burns (10 hr. duration)
to establish the DREs for dioxin (Ross, et al., 1986).
The results of the two full waste burns are presented in Table 4.1.1.
The data show that the 2,3,7,8-TCDO ORE was greater than 99.9997 percent as
measured in the virtual stack (E-DUCT) which would correspond to the stack of
an actual hazardous waste incinerator. The reason six nines DRE could not be
established was that the detection limits experienced in the sampling and
analysis protocols used were not sufficiently low (Ross, et al., 1986; Carnes,
1986). Despite this, it was concluded from the data in the study that
"incineration under the conditions existing in the CFR pilot incineration
system for these tests is capable of achieving 99.9999 percent dioxin DRE"
(Ross, et al., 1986). It was further concluded that land-based incineration
should be considered a viable disposal method for the Vertac still bottoms
waste given that appropriate safeguards are employed (Ross, R. W., et al.,
1986).
The concentrations of 2,3,7,8-TCDD and other CDDs and CDFs were also
measured in the scrubber blowdown water and kiln ash (Ross, et al., 1986).
The maximum concentration of 2,3,7,8-TCDD detected in the scrubber blowdown •
was 0.12 picograms per milliliter (approximately 0.1 ppt). In most samples of
blowdown, all forms of CDDs were undetected at detection limits of 0.006 to
0.020 pg/ml. In one sample, however, 0.78 pg/ml of Octa-CDD was detected. No
2,3,7,8-TCDF was detected in any blowdown samples. Total TCDF was detected at
0.20 pg/ml in all 4 samples. Tetra-, penta-, hexa- and hepta- CDD and CDFs
were not detected in any of the kiln ash samples at detection limits ranging
from 1.3 to 37 picograms per gram (ppt).
4-11
-------
Since in all cases the residues from this incinerator contained CDDs and
CDFs at levels below I ppb, it would be.expected that these residues could De
land disposed in accordance with the screening levels proposed in 51 FR 1602.
These screening levels are based on the use of a different analytical method
(Method 8280) than used in the present situation. Therefore, definite
conclusions cannot be made. Nonetheless, the concentrations of CDDs and CUFs
detected in the treatment residues indicate that a high degree of destruction
did occur.
Several problems encountered during the trial burns should be mentioned.
These include (Ross, et al., 1986):
I. Waste was fed into the kiln through a water-cooled feed lance using
a Moyno cavitation pump. The lance frequently became clogged due to
carbon-buildup from coking of the waste material.
2. The test plan called for continuous monitoring of flue gas, CO^,
02, CO and NOX, at the stack with one set of emission analyzers
and at the kiln exit and afterburner exit on a time-share basis with
another set. However, only one set of emission analyses was
operational during most of the test series. Therefore, no kiln
emission monitoring data were obtained. Very little simultaneous
afterburner exit and stack data were obtained.
3. An air leak in the sample transfer line from the afterburner exit to
the monitors caused the data to be "substantially compromised".
Also, difficulties were encountered while monitoring by means of the
isokinetic Method 5 sampling train (MM5). The glass frit in the MM5
train condensor/XAD2 sorbent cartridge frequently became plugged.
Most exhaust and stack sampling was at less than 50 percent
isokinetic, which compromises the particulate emission results.
4.1.3 Costs of Treatment
Currently, there are no stationary kilns permitted to burn dioxin
wastes. Thus, no costs are available. However, these costs would be expected
to be similar to or greater than the costs for PCBs incineration. Table 4.1.2
lists the average unit coats for PCBs wastes at the currently permitted
stationary rotary kiln facilities.
4-13
-------
4.1.4 Process Status
Land-baaed incineration systems with potential to treat dioxin wastes
«
include commercial incineration facilities which have been approved for PCB
disposal, in addition to RCRA hazardous wastes. These incinerators are
operated by Rollins Environmental Services (Deer Park, Texas), ENSCO
(El Dorado, Arkansas) and SCA (Chicago, Illinois). Each of these systems
contains a rotary kiln incinerator followed by an afterburner section which
can also be used independently as a liquid injection incinerator.
The Rollins and ENSCO facilities can accept both liquid and solid wastes,
but the SCA incinerator has only been approved for the disposal of liquid PCB
wastes. The following are the maximum feed rates for these land-based
incineration systems (GCA, 1985; Clarke, 1986):
Rollins 1,440 Ib/hr for solids
(Deer Park, TX). 6,600 Ib/hr for liquids
ENSCO 2,500 Ib/hr for solids
(El Dorado, AK.) 5,000 Ib/hr for liquids
SCA 2,910 Ibs/hr for solids
(Chicago, IL.) 6,300 Ibs/hr for liquids
Although none of these facilities has conducted trial burns for the
destruction of dioxin-contaminated waste, their ability to demonstrate six
nines DRE for PCBs suggests that they would be able to destroy dioxins.
Results of trial burns using the CRF pilot-scale rotary kiln incinerator show
the potential for dioxin destruction at the RCRA regulated DRE.
4-15
-------
SOL ns HAM
FEED SYSTEM
QUENCH ELBOW
CHEAT
iSTACK GAS ANALYSIS
ITHC. NO.. SOj. Oj. CO COjl
COMBUSTION OAS ANALYSIS
tOjCOCOjt
SECONOAHY
COMBUSTION
CHAMBER
Figure 4.2.1. Schematic of EPA mobile incineration system [U.S. EPA, 1984].
-------
"1 DEAERATOR
WATER TREATMENT
PACKAGE
JMAIfH
J
VO
SECONDARY COUBUSTM
U
D
DRUM
1,
'
1
MAKE-UP WATER f x—
-»
\(
oe
Ul
*
o
8
N
4
V
WASTE HEAT
BOILER
•T——" PUILtH
LriP
I BLOWOOWN
•TLTRATION AIR
Rowrr KILN
HYDROSONICS
SCRUBBER
i
J
IWI
•——1 _^~ "NJ 1^
DCMISTER
J^CIRC TANK
COMCENTRATOR
Figure 4.2.2. Schematic flow diagram of ENSCO MWP-2000 Mobile Rotary Kiln Incinerator
[Pyrotech Systems, 1985].
-------
Operating Parameters—
Operating parameters for the two mobile rotary kiln systems are
«
summarized below (U. S. EPA, 1984; Sickels, 1986; Freestone, et al., 1985):
EPA/MIS ENSCO
Waste Forms Solid*, Solids,
Liquids Liquids
Maximum Waste Feed Rat* (Ib/hr)
-Solids to Rotary Kiln 9,000 10,000
-Liquids to Rotary Kiln 3,000
-Liquids to SCO 1,500 4,000
Kiln Temperature (°F) 1800 1800
SCC Temperature (°F) 2200 2200
SCC Residence Time (sec) 2.2 2
Severe weather conditions can effect the operation of the mobile
incinerator. For instance, extremely cold weather during the initial stages
of the EPA Mobile incinerator trial burns on the Denney Farm site caused the
No. 2 diesel fuel to gel, hydraulic fluids to thicken, and water lines to
freeze (IT Corporation, 1985a; Krogh, 1985).
4.2.2 Technology Performance Evaluation
Initial trial burns with the EPA mobile incinerator were conducted in
Edison, New Jersey using surrogate compounds to mimic RCRA-listed constituents
such as dichlorobenzene, trichlorobenzene, tetracblorobenzene, and PCBs. In
these liquid waste trial burn*, up to six nines DRE of PCBs was demonstrated.
Following this, laboratory studies were conducted to establish optimum
conditions for treating soils contaminated with dioxin. The following
conclusions were made based on these studies (IT Corporation, 1985a):
Thermal treatment of contaminated Missouri soils was capable of
achieving I ppb or lower concentration of residual 2,3,7,8-TCOO and
other chlorinated dioxins and chlorinated furans in the incinerator
ash.
4-21
-------
TABLE 4.2.1.
SOILS USED IN THE EPA MOBILE INCINERATOR DURING
PRELIMINARY TESTING OF THE SOLIDS FEED SYSTEM
Soil type
Test purpose
Particulate
emissions
Denney Farm
Area Soil
Montmorillonite
Coral from Florida
Clarksburg
(New Jersey) Soil
To ensure that there were
no unusual problems with
soil from that area; Site
soil was very dry from being
stored
Planned to be used as the
Solids Carrier in Test 1
of Solids Trial Burn
Potential Future Use of
EPA/MIS for U.S. Air Force
on Johnston Island
Contaminated Coral
Readily Available Soil
in the Missouri Area
18 mg/Nm3
17 mg/Nm3
9 mg/Nm3
Not Available
Reference: IT Corporation, I985a.
4-23
-------
TABLE 4.2.3.
MISSOURI DEPARTMENT OF NATURAL RESOURCES AND EPA DEL1STING
PARAMETERS FOR ORGANIC CONSTITUENTS IN INCINERATOR ASH
AND SCRUBBER WASH WATER
Toxic Constituent
Concentration
Ash
ScruDoer water
Dioxins/Dibenzofurans*
2,3,4-Trichlorophenol
2, 3, 5-Trichlorophenol
2 , 4, 6-Trichlorophenoi
2, 5-Dichlorophenol
3,4-Dichlorophenol
2, 3, 4, 5-Tetrachlorophenol
2,3,4,6-Tetrachlorophenol
1,2,4, 5-Tetrachlorobenzene
1,2,3, 5-Tetrachlorobenzene
Hexachloropnene
Polychlorinated Biphenyla
Benzo(a)pyrene
BenzoC a) anthracene
Chrysene
DibenzoCa, h) anthracene
IndenoC 1,2, 3-c,d) pyre ne
BenzoC b)f louranthene
I ppb
100 ppm
100 ppm
1 ppm
350 ppb
100 ppm
I ppm
I ppm
100 ppm
100 ppm
200 ppm
2 ppm
5 ppm
5 ppm
50 ppm
5 ppm
5 ppm
5 ppm
10 ppt
10 ppm
10 ppm
50 ppb
15 ppb
10 ppm
50 ppb
5U ppb
10 ppm
10 ppm
5 ppm
1 ppm
10 ppb
10 ppo
I ppm
10 ppb
10 ppb
10 ppb
•Weighted average of TCDD«/TCDF», PeDDa/PeDFs, and HxCDDs/HxCDFs using
toxicity weighting factor*.
Reference: Poppiti, 1985; U.S. EPA, 1985.
4-25
-------
Average operating parameters during the trial burn for dioxin-contaminated
soil and liquids were as follows (IT Corporation, 1985 a and b; U. S. EPA,
1985):
Kiln Temperature ' 1800°F
SCC Temperature 2200°F
SCC Combustion Gas 13,500 acfm
Flow Rate
SCC Residence Time 2.6 seconds
Waste Feed Rate 2000 Ib/hr (soil)
250 Ib/hr (liquid)
Auxiliary Fuel
-Kiln 5 to 6 million Btu/hr
-SCC 4 to 5 million Btu/hr
Following the successful (demonstrating 99.9999 percentDRE) completion
of these preliminary trial burns, additional test burns were planned for the
EPA/MIS as summarized in Table 4.2.4. As noted in the table, burns of the
material from five of these sites (Denney Farm, Neosho, Erwin Farm, and Talley
Farm) have been completed. The total amount of dioxin-contaminated material
that was successfully burned (i.e., achieved greater than six nines DRE)
included 2 million pounds of soils and 180,000 pounds of liquids (Hazel, 1986;
Freestone, 1986). The material from the remaining sites listed in Table 4.2.4
is scheduled to be burned as soon as funding becomes available (Hazel, 1986).
Currently, the amount of dioxin-contaminated material that remains to be
burned includes 600,000 pounds of soil and 80,000 pounds of liquid wastes
(Hazel, 1986).
During the incineration of the dioxin-contaminated wastes from these
sites, several parameters were monitored continuously, including: CO, CO.,
0_, NO , operating temperatures and feed rates (Hazel, 1986; Freestone;
1986). Built-in safety controls cause the operations to stop if any of these
parameters are not within the proper range (Hazel, 1986). In addition, the
waste residues from the burns (i.e., ash and water) are continually
monitored. To date, dioxin has never been found in the burn residues (Hazel,
1986). More detailed data will be available in the Final Report scheduled for
release within the next few months (Freestone, 1986).
4-27
-------
TABLE 4.2.5. EMISSION DATA FOR THE ENSCO MOBILE INCINERATOR (MWP-75J
PCB TRIAL BURN
Condition Result
PCB ORE >99.9999Z
Carbon Monoxide 20 ppm
Nitrogen Oxides 300 to 500 ppm
Particulate Met or exceeded all standards
HC1 Scrubbing 99Z at 1,500 Ib UCl/hr
Reference: Sickels, 1986; Pyrotech Systems, 1985.
4-29
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Initially, ENSCO encountered slagging problems which were solved by
adding six chutes to the secondary unit and a cyclone was installed prior to
the secondary unit to remove fine particulates (Pyrotech Systems, 1985).
These modifications increase the treatment costs.
One of the MWP-2000 units is currently located at a site near Tampa,
Florida where it is being used to clean up a site containing liquids
contaminated with chlorinated organics (McCormick, 1986; Lee, 1985). A second
MWP-2000 unit located at the El Dorado, Arkansas facility (i.e., the location
of the ENSCO stationary rotary kiln system) has just completed a series of
dioxin trial burns using wastes from the Vertac Site. The results are
expected to be released in Nay 1986 (McCormick, 1986). The construction of
the third MWP-2000, a computer-operated unit, is not complete yet. Upon
completion, this third unit is scheduled to undergo tests by the Air Force to
handle dioxin-contaminated coral at Johnston Island (Lee, 1985; McCormicK,
1986).
4-31
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EFFLUENT DIRECTLY TJD ATMOSPHERE
OR TO SCRUBBERS AND STACK
FREE STANDING
INTERLOCKING REFRACTORY
MODULES
TEMPERATURE MEASURING
INSTRUMENTS
UPPER NACELLE
TURBO-BLOWER
IGNITION CHAMBER
HIGH VELOCITY
AIR SUPPLY
AIR-WASTE ENTRAINMENT
COMPARTMENT
WASTE LINE
FRESH AIR INTAKE
FOR TUR6O-BLOWER
AND AFTERBURBER FAN
AIR CONE
— DECOMPOSITION CHAMBER
DECOMPOSITION STREAM
AFTER-BURNER FAN
FiAME SENSITI2ER
TURBULENCE COMPARTMENT
LOWER NACELLE
AUXILIARY FUEL LINE
TUBULAR SUPPORT COLUMNS
0^12345 fttt
Appro*imote Scon
ELECTRICAL POWER LINE
Figure 4.3.1. Vertically-oriented Liquid Injection Incinerator
[Bonner, 1981].
4-33
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Operating Parameters—
Typical operating parameters for the vertically-configured LI incinerator
on the Vulcanus are as follows (U. S. EPA, 1983; U. S. EPA, 1978):
Residence Time 0.5 to 2.0 seconds
Temperature 650 to 1750°C (1200 to 3180°F)
Air Feed Rate 65,000 to 75,000 m3/hr
Waste Feed Rate Capacity 7 to 10 tons/hr
4.3.2 Technology Performance Evaluation
The only documented burns of waste containing dioxins in a liquid
injection incinerator are those that took place on board incinerator ships.
These burns took place between July and September 1977. Three shiploads
(totalling approximately 10,400 metric tons) of U.S. Air Force stocks of
Herbicide Orange were incinerated by the M/T Vulcanus in the Pacific Ocean
west of Johnston Atoll (U. S. EPA, 1978). A summary of the DREs achieved in
these burns and other U.S.-sponsored ocean burns is presented in Table 4.3.1.
Operating parameters for these Herbicide Orange trial burns are summarized in
Table 4.3.2.
The Herbicide Orange stock consisted of an approximately 50-50 volume
mixture of the n-butyl esters of 2,4-dichlorophenoxyacetic acid (2,4-0) and
2,4,5-trichlorophenoxyacetic acid (2,4,5-T) (U. S. EPA, 1978). A small
quantity of the stock contained a 50-50 volume mixture of 2,4-D and the
iso-octyl ester of 2,4,5-T. Certain lot* also contained 2,3,7,8-TCDD ranging
in concentration from 0 to 47 ppm (with an average concentration of 1.9 ppm).
Drums containing the waste stock and waste handling equipment were rinsed with
diesel fuel which was subsequently mixed with the waste feed to increase its
heating value for incineration (U. S. EPA, 1978).
4-35
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TABLE 4.3.2. SUMMARY OF OPERATING PARAMETERS FOR
HERBICIDE ORANGE TRIAL BURNS USING LIQUID
INJECTION INCINERATION ON THE VULCANUS
Flame Temperature 1375-1610'C
«
Furnace Wall Temp. UOO-1200°C
Residence Time 1.0 to 2.0 seconds
Reference: U. S. EPA, 1978
During the period from December 1981 through January 1982, the first
ocean burn of PCBs was performed in U.S. waters (U. S. EPA, 1983). A second
shipload of PCB-containing wastes were incinerated aboard the M/T Vulcanus
during August 15-31, 1982 (U. S. EPA, 1983). Operating parameters for the
PCBs burns are sunmarized in Table 4.3.3. An EPA-sponsored test project was
performed during the second PCBs trial burn to measure emissions of
polychlorinated biphenyls (PCBs), chlorobenzenes (CBa),
tetrachlorodibenzofurans (TCDFs), and tetrachlorodibenzo-p-dioxins (TCDDs).
TABLE 4.3.3 SUMMARY OF OPERATING PARAMETERS FOR
PCB TRIAL BURNS USING LIQUID INJECTION
INCINERATION ON THE VULCANUS
Flame Temperature 1648-2048°C
Furnace Wall Temp. 1281-1312°C
Residence Time 1.1 to 1.5 seconds
Feed Rate 5.23-6.79 mt/hr
Reference: U. S. EPA, 1983.
No TCDDs were detected in any sample of waste or stack gas during the
tests. Detection limits for the waste ranged from less than 2 ppb to less
than 22 ppb. TCDFs, however, were detected in the waste feed at ppb levels
and in the stack gas at low ppt levels. [USEPA, 1983]
4-37
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TABLE 4.3.4. SUMMARY OF LIQUID ,INJECTION INCINERATION TRIAL BURN
RESULTS FOR PCBs - GENERAL ELECTRIC, PITTSFIELD, MA
Parameter
Trial burn results
Temperature Inside the Reactor Chamber
Residence (Dwell) Time of Combustion Products
Combustion Efficiency
Oxygen Concentration during PCB Incineration
Waste Oil Firing Rate
PCB Concentration in Oil
Average PCB Destruction Efficiency
Average PCB Destruction and Removal Efficiency
HC1 Scrubber Efficiency
Particulate Emissions @ 12Z
NOX Emissions
RC1 Emissions
HC1 Emissions
Reference: Tnayer, et al.. 1983.
1,262°C - 1,
(2,303°F - 2,085°F)
4.02 sec
99.9932
9.5 - 10.51
1.09 - 119 GPM
18.4 - 20.OZ
99.999982Z
99.999982Z
99.82Z
0.543 Ib/hr
0.0361 gr/dscf
18.3 ppm
0.43 Ib/hr
0.000304 ppm
0.00002542 Ib/hr
0.2752 Ib/hr
4-39
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4.4 FLUIDIZED BED/CIRCULATING FLUIDIZED BED (CFB) SYSTEM
4.4.1 Process Description
The fluidized bed incinerator uses"high temperature oxidation under
controlled conditions to destroy organic constituents in liquid, gaseous, and
solid waste streams. It is typically used for slurries and sludges.
As shown in Figure 4.4.1, a typical fluidized bed incinerator consists of
a vertical refractory-lined cylindrical vessel containing a bed of inert
granular material (typically, sand) on a perforated metal plate. The waste
(in the form of either gas, liquid, slurry, or sludge) is usually injected
into or just above the stationary bed. The granular bed particles are
fluidized by blowing air upward through the medium. The resulting agitation
ensures intimate mixing of all waste material with combustion air (McGaughey,
et al., 1984; Bonner, 1981).
A burner located above the bed is used to heat the bed to start-up
temperature. The large mass and high heat content of the bed causes the waste
to rapidly combust which, in turn, transfers heat back to the bed. The
maximum temperature of the granular bed is limited by the softening point of
the bed material (for sand this temperature is 1100°F). The residence time of
waste material in the bed typically ranges from 12 to 14 seconds for liquid
wastes. TV* solid uncombustible materials in the waste become finely
suspended particul*te matter which is separated in a cyclone while the exhaust
gases pass through an afterburner to destroy vapor-phase residuals (McGaughey,
et al., 1984; Bonner, 1981).
Waste Tech Services, Inc. has developed a Low-Temperature Fluidized Bed
that functions similarly to the conventional fluidized bed except that a
higher air volume is forced through the bed material (Rasaussen, 1986;
Freeman, 1985). Also, the bed is composed of a mixture of a granular
combustion catalyst and limestone. Limestone is continuously added to the bed
and the bed material ia periodically drained from the vessel. A multicyclone
system employing a baghouse to clean the flue gas is used for air-pollution
control. The Waste-Tech fluidized bed is able to operate at lower
temperatures than conventional fluidized bed* and also has reduced
supplemental fuel requirements (Rasmussen, 1986; Freeman, 1985).
4-41
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Another modification of the conventional fluidized bed technique that has
been developed is the Circulating Fluidized Bed Com buster (Figure 4.4.2). It
utilizes contaminated soil as the bed material and air flow rates 3 to 5 times
greater than conventional systems (Rickman, et al., 1985; Vrable, et al.,
I985a and b; Barner, 1985). The high air flow causes increased turbulence
which allows for efficient combustion at much lower operating temperatures
without requiring the use of an afterburner. A comparison of the circulating
fluidized bed combustor with the conventional fluidized bed is shown in
Table 4.4.1.
The startup combustor burner consists of a natural gas fuel system
(Rickman, et al., 1985; Vrable, et al., 1985a and b; Barner, 1985). It has a
4 to 6 hour cold startup period, and an approximately 30 minute hot restart
(with a refractory temperature at or greater than 1400°F). The startup burner
is generally idle during waste burning unless the waste feed is interrupted
and it is required to maintain a low combustor temperature. The combustor is
a carbon-steel tube with refractory lining which consists of an
erosion-resistant inner layer and a thermal insulating outer layer. Prior to
being injected into the combustion chamber the waste feed is mixed with hot
recirculating solids from the cyclone. Both the waste feed and the
recirculated solids are introduced into the combustion chamber. Liquid and
slurry waters are pumped from stirred tanks whereas a metering screw is used
to convey solids and sludges.
The combustor has primary and secondary air ports through which
fluidizing air is provided by a constant-speed, motor-driven forced-draft fan
(GA Technologies, 1985; Rickman, et al., 1985). The high air velocity (15 to
20 feet/second) entrains both the bed and the combustible waste which rise
through the reaction zone to the top of the combustion chamber and pass into a
hot cyclone.
The cyclone is constructed of carbon-steel and lined with castable
refractory lining. The function of the cyclone is to separate bed material
from the combustion gases and recirculate these solids to the combustion
chamber. The hot combustion gases flow to an off-gas heat exchanger where
they are cooled to 375°F and then directed to baghouse filters to remove any
residual products of incomplete combustion (GA Technologies, I9bi; Ricwnan, et
al., 1985).
4-43
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TABLE 4.4.1. COMPARISON OF CONVENTIONAL FLUIDIZED BED WITH
CIRCULATING FLUIDIZED BED COMBUSTOR
Condition
Circulating fluidized bed Conventional fiuidized bed
Feeding
No. of Inlets
Sludge Feeding
Solids Feed-size
Pollution Control
POHCa
Cl.S.P
Upset Response
Effluent
Efficiency
Thermal
Carbon
1-solid; 1-liquid
Direct
7Sl
>98X
5-solid; 5-liquid
Filter/Atomizer
<0.5-0.25 in.
In high temp, combustor
or afterburner
Downstream scruboer
Bypass scrubber pollution
release
Wet Ash Sludge
>75X
>90Z
Reference: Rickman, et al., 1985
4-45
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4.4.2 Technology Performance Evaluation
Fluidized beds have been used Co treat municipal wastewater treatment
plant sludges, oil refinery waste, pulp and paper mill waste, pharmaceutical
t
wastes, phenolic wastes, and methyl methacrylate. Pilot-scale demonstrations
have been performed for other hazardous wastes. Currently, there are more
than 25 circulating bed combustors operating in the U.S. and Europe. However,
there are currently no units operating commercially as hazardous waste
incinerators (Freeman, 1985; Rickman, et al., 1985).
The low-temperature fluidized bed combustor (designed by Waste Tech
Services, Incorporated) was used to conduct trial burns on soil contaminated
with carbon tetrachloride and dichloroethane (Freeman, 1985). Only four nines
DRE was demonstrated. The results of these tests are summarized in Table
4.4.2.
GA Technologies has conducted trial burns on its pilot scale circulating
bed combustor using chlorinated organic liquid wastes. The combustor was
operated at 1540 to 1600°F with a gas velocity of 11 to 12 feet/second and 45
to 60 percent excess air. Limestone was injected into the incinerator with
the liquid waste feed to prevent the formation of HC1 by capturing the
chlorides formed. The following results were obtained (Rickman, et al., 19»5;
Chang and Sorbo, 1985):
NOX emissions 40 ppm (average)
SC>2 emissions 250 to 350 ppm
CO emissions 1000 ppm
Chloride Capture 99Z
Flue Gas Emissions (Z-DRE)
- Ethylbenzene >99.99
- 1,1,2-trichloroethane >99.99
- 1,2-dichloroethane >99.99
- l,l-dichloroethylene >99.99
- 1,2-transdichloroethylene >99.99
- vinyl chloride >99.99
- toluene >99.99
- benzene >99.99
4-47
-------
The pilot-scale unit was also used to conduct trial burns on
PCB-contaminated soil (Rickman, et al., 1985; Chang and Sorbo, 1985). An
auxilliary fuel was used to maintain bed temperature at 1600 to 1800°F. A
destruction efficiency exceeding six nines (99.9999 percent) was achieved. A
<•
summary of the test conditions and results is given in Table 4.4.3.
4.4.3. Costs of Treatment
The costs for the conventional fluidized bed are dependent on fuel
requirements, scale, and site conditions. However, the costs are generally
comparable with conventional rotary kiln incineration technology. Waste-Tech
Services, Inc. lists the costs in Table 4.4.4 as being typical for their
low-temperature fluidized bed (Freeman, 1985).
Costs for the circulating bed combustor vary according to the size of the
incineration unit, and the type of waste being processed. Estimated costs for
a 25 million Btu/hr unit are given in the Table 4.4.5 (Freeman, 1985):
4.4.4 Process Status
Currently, there are several fluidired bed combustors operating
worldwide. Although fluidized beds have been used in various industries, at
the present time there are not any fluidized beds operating commercially as
hazardous waste incinerators. However, the fluidized bed, particularly the
circulating fluidized bed, appear to have significant potential for future use
in the destruction of hazardous wastes.
The low-temperature fluidized bed developed by Waste Tech Services
requires additional testing and/or development, but could potentially be used
for the destruction of dioxin contaminated wastes.
A stationary pilot scale circulating fluidized bed unit capable of
incinerating a ton per hour of hazardous waste is in operation at the GA
Technologies test facility. A transportable incinerator has also been
constructed for use in onsite demonstrations on PCBs contaminated wastes.
Although dioxin trial burns have not been conducted, GA Technologies would be
interested in performing dioxin testing if funding were available (Jensen,
1986).
4-49
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TABLE 4.4.4. WASTE-TECH FLUIDIZED BED COSTS
Item . Cost
Operating Labor 0.0084 t/lb
Consumables and Utilities 0.0138 t/lb
Nonlapor (capital depreciation,
siting cost, maintenance mat'Is,
insurance, tax overhead) 0.0116 $/lb
Limestone for Chlorine Removal,
Waste Excavation, Ash Disposal, etc. 0.043 $/lb
TOTAL COST $150/ton
Note: These cost estimates are for a SO sq.ft. system with a throughput of
9,200 Ib/br for soils having 2 percent organics and 5 percent moisture
content.
TABLE 4.4.5. CIRCULATING FLUIDIZED BED COSTS
Installed Annual Total Cost per
Feed Type Capital Operating Unit of Feed
Costs Costs
Chlorinated
Organic Sludge $2.0 million $0.25 million $60/ton
Contaminated
Soil
Wet Sludge
$1.8 million
$1.8 million
$0.35 million
$0.35 million
$27/ton
$32/ton
Note: Costs are based on the use of a 25 million Btu/hr unit.
4-51
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1. EXPANSION BELLOWS
2 POWER FEEDTHROUGH
COOLING MANIFOLD
4. POWER
FEEDTHROUGH
ASSEMBLY
6. END PLATE
ELECTRODE
10. RADIATION
HEAT SHIELD
77. HEAT SHIELD
INSULATOR
72 COOLING JACKET
3. POWER CLAMP
5. RADIATION
DEFLECTOR
7. ELECTRODE
CONNECTOR
9. POROUS CORE
13. RADIOMETER PORT
. BLANKET GAS INLET
(TYPICAL)
Figure 4.5.1. Advanced Electric Reactor [Huber],
4-53
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residence time (5 seconds). The second postreactor treatment zone is
water-cooled, and its primary purpose is to cool the gas prior to downstream
particulate cleanup.
Off gas cleaning equipment includes a cyclone to collect particles which
do not fall into the solids bin, a bag filter to remove fines, an aqueous
caustic scrubber for acid gas and free chlorine removal, and two banks of five
parallel activated carbon beds in series for removal of trace residual
organics and chlorine.
The stationary pilot scale reactor which has been used for testing
various wastes at their Borger, Texas facility consists of a porous graphite
tube, 1 foot in diameter and 12 feet high, enclosed in a hollow cylinder with
a double wall cooling jacket. This pilot unit is capable of processing 5000
tons/yr of waste. Huber also has a 3 inch diameter mobile unit which has been
transported to hazardous waste sites for testing purposes. Test results are
described below.
Restrictive Waste Characteristics—
The AER cannot currently handle two-phase materials (i.e., sludge); it
can only burn single-phase materials consisting of solids, or liquids, or
gases alone (Schofield, 1985; Boyd, 1986). Generally, a solid feed must be
free flowing, nonagglomerating, and smaller than 100 mesh (less than 149
micrometers or 0.0059 inches) (GCA, 1985; Shofield, 1985). However, depending
on the required destruction, solids larger than 100 mesh (but smaller than
10 mesh) may be suitable. Soils should be dryed and sized before being fed
into the reactor.
Also, the Huber process is not cost competitive with standard thermal
destruction techniques (such as the rotary kiln) for materials with a high Btu
content (Schofield, 1985; Boyd, 1986). It is cost-effective for wastes with a
low Btu content (i.e., PCBs and dioxin) because unlike standard thermal
destruction techniques, the Huber process does not require supplementary fuels
to obtain the necessary Btu content for incineration.
4-55
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TABLE 4.5.1. SUMMARY OF OPERATING PARAMETERS AND RESULTS
FOR HUBER AER RESEARCH/TRIAL BURNS
Condition
Reactor Core
Temperature (F)
Waste Feed
Rate (Ib/tnin)
Nitrogen Feed
Rate («cfm)
Z-DRE
PCBs
(Sept. 1983)
4100
15.5-15.8
147.2
>99. 99999
CC14
(May 1984)
3746-4418
1.1-40.8
104.3-190.0
>99.9999
Dioxins
(Oct/Nov 1984)
3500-4000
0.4-0.6
6-10
>yy.yy9
Reference: Schofield, 1984; Roy F. We•ton, 1985.
4-57
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4.5.3 Costa of Treatment
Operating costs will vary depending on the quantity of material to be
processed and the characteristics of the waste feed (Lee, et al., iy«4).
<•
Pretreatment may be necessary for bulky wastes having a high moisture
content. Typical energy requirements for normal soil range from 8UO to 1000
kwh/ton.
Cost estimates for processing a site containing more than 100,QUO tons of
waste material were approximately $365 to $565/ton in 1985 (Lee, et al., 1984;
Freeman and Olexsey, 1986). The cost breakdown for this estimate was
12 percent for maintenance, 7 percent labor, 29 percent energy, 18 percent
depreciation and 34 percent for other costs (permitting, setup,
post-treatment, etc.). These costs have recently been updated. The new costs
are expected to be released in May 1986 (Boyd, 1986).
4.5.4 Process Status
The J.M. Huber Corporation purchased the patent rights from Thagard
Research Corporation. Huber then modified the design of the reactor
(primarily the feed tube and the core design) to improve the efficiency of the
reactor, extend the lifetime of the electrodes and core material, and to
reduce sticking of vitreous material on the core walls (which lowers
efficiency) (Boyd, et al., 1986).
Huber maintains two fully-equipped reactors at their pilot facility in
Borger, Texas (Schofield, et al., 1985). The smaller reactor, which is
equipped for mobile operation, has a 3-inch core diameter and a capacity of
0.5 Ib/min.. The larger reactor is commercial scale with a 12-inch core
diameter and a capacity of 50 Ib/min. Both of these reactors are used
primarily for research purposes. In May 1984, the Huber reactor was certified
by the EPA under TSCA to burn PCB wastes. Recently, the U.S. EPA and the
Texas Water Commission jointly issued J.M. Huber Corporation a RCRA permit
which authorizes the incineration of any non-nuclear RCRA hazardous waste
(including dioxin-containing wastes) in the Huber Advanced Electric
Reactor (AER)(HMIR, 1986). This was the first commercial permit issued under
4-59
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4.6 INFRARED DESTRUCTION (Shirco)
4.6.1 Process Description (Daily, 1986; Shirco, 1985; Freeman and Olexsey,
1986; HMIR, 1986; Technical Resources Inc., 19b5; Daily, iy»5)
Shirco Infrared Systems, Inc. has developed a portable infrared
incineration system, which can be transported in a 45 ft trailer. The major
components of the system include a feed metering system, an infrared primary
chamber furnace, a combination propane-fired/infrared secondary chamber, a
venturi scrubber system, blower and heating control systems, and a monitoring
and control system.
The waste material is fed by bucket or inclined conveyor onto a metering
conveyor which controls the amount and rate of waste feed into the primary
furnace. The primary furnace chamber is constructed of carbon steel, lined
with multiple layers of ceramic fiber blanket-insulation mounted on stainless
steel studs and retained with ceramic fasteners. The external dimensions of
the primary chamber are 2.5 ft x 9 ft x 7 ft, and it weighs (installed)
3,000 Ibs. Infrared heating elements, consisting of silicon carbide rods with
external electrical connections at each end, are spaced along the length of
the furnace. The chamber can be heated to temperatures ranging from 500 to
1,050°C. Residence times for the feed material are variable ranging between
10 and 180 minutes. The temperatures and times will depend on the
characteristics of the waste.
Following combustion, the ash (or processed material) is conveyed to the
end of the furnace where it drops off the belt and passes through a chute into
an enclosed, tapered hopper. A discharge screw conveyor controls transport of
the discharged material from the hopper into sealed collection drums.
Combustion air is forced through a combustion air preheater and then
injected at 10 points along the length of the primary chamber furnace.
Depending on the waste characteristics, the exhaust gases may be directed to a
secondary combustion chamber to complete gas-phase combustion reactions.
The secondary chamber is a rectangular carbon steel box lined with a
ceramic fiber blanket insulation. The secondary chamber weighs 1,500 Ibs and
has external dimensions of 3 ft x 9 ft x 3 ft. Combustibles in the gas are
ignited via a propane-fired burner and are maintained at a predetermined
setpoint temperature using an array of silicon carbide heating elements which
4-61
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TABLE 4.6.1 OPERATING PARAMETERS AND RESULTS FOR SHIRCO INFRARED
DESTRUCTION PILOT TESTS
Condition Test 1
TCDD in Feed
(ng/g) 227
Solid Phase
Residence Time
Uin) 30
Solid Feed
Rate (Ib/hr) 47.68
Primary Chamber
Temp. -Zone A (°F) 1560
Primary Chamber
Temp. -Zone B (°F) 1550
Secondary Chamber
Temperature (°F) 2250
Emissions Sampling
Duration (hours) 7
Particulate at
7Z 02 (gr/dscf) 0.0010
Gas Phase DRE of
2, 3, 7, 8, -TCDD >99. 999996
at Detection Limit
(pic OR rams) 14
Ash Analysis for
2,3,7,8-TCDD ND
at Detection
Limit (ppt) 38
Test2
156
L5
48.12
1490
1490
2235
2.5
0.0002
>99. 999989
0.4
ND
33
Reference: ERT, 1985; Daily, 1986.
4-63
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4.7 PLASMA ARC PYROLYSIS
4.7.1 Process Description
Operation and Theory—
In this process waste molecules are destroyed by the action of a thermal
plasma field. The field is generated by passing an electrical charge through
a low pressure air stream, thereby ionizing the gas molecules and generating
temperatures up to 10,000'C.
A flow diagram of the plasma pyrolysis system is shown in Figure 4.7.1.
The plasma device is horizontally mounted in a refractory-lined pyrolysis
chamber with a length of approximately 2 meters and a diameter of 1 meter.
Liquid wastes are injected through the colinear electrodes of the plasma
device where the waste molecules dissociate into their atonic elements. These
elements then enter the pyrolysis chamber which serves as a mixing zone where
the atoms recombine to form hydrogen, carbon monoxide, hydrogen chloride and
particulate carbon. The approximate residence times in the atomization zone
and the recombination zone are 500 microseconds and 1 second, respectively.
The temperature in the recombination zone is normally maintained at
900-1,200°C (Barton, 1984).
After the pyrolysis chamber, the product gases are scrubbed with water
and caustic soda to remove hydrochloric acid and particulate matter. The
remaining gases, a high percentage of which are combustible, are drawn by an
induction fan to the flare stack where they are electrically ignited. In the
event of a power failure, the product gases are vectored through an activated
carbon filter to remove any undestroyed toxic material.
The treatment system that is currently being used for testing purposes is
rated at 4 kg/minute of waste feed or approximately 55 gal/hour. The product
gas production rates are 5-6 m /minute prior to flaring. To facilitate
testing, a flare containment chamber and 30 ft stack have also been added to
the system. The gas flow rate at the stack exit is approximately
36 m /minute (Kolak, Barton, Lee, Peduto, 1986).
A major advantage of this system i* that it can be moved from waste site
to waste site as desired. The entire treatment system, including a
laboratory, process control and monitoring equipment, and transformer and
switching equipment, are contained on a 45 ft tractor-trailer bed (Barton,
1984).
4-65
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Two residual streams are generated by this process. These are the
exhaust gases released up the stack as a flare, and the scrubber water
stream. Since the product gas (after scrubbing) is mainly hydrogen, carbon
monoxide, and nitrogen, it burns with a clean flame after being ignited.
«
Analysis of the flare exhaust gases, presented in the following section,
•
indicates virtually complete destruction of toxic constituents.
The scrubber water stream is composed mainly of salt water from
neutralization of HC1 and particulates, primarily carbon. Analyses of the
scrubber water for the waste constituent of concern (e.g., carbon
tetrachloride (CC1.) and PCB in the feed material) have shown that the
constituents were present at low ppb concentrations. The quality of scrubber
water generated would depend on the water feed rate and corresponding product
gas and scrubber waste flowrates. During a test in which 2.5 Itg/min of waste
containing 35 to 40 percent CC1, was fed to the reactor, a scrubber water
effluent flowrate of 30 I/minute was generated (Kolalc, Barton, Lee,
Peduto, 1986).
Restrictive Waste Characteristics—
The reactor as it is currently designed can only be used to treat liquid
waste streams with viscosities up to that of 30 to 40 weight motor oils.
Particulates are removed by a 200 mesh screen prior to being fed into the
reactor. Contaminated soils and viscous sludges cannot be treated. The TCDD
wastes for which this technology has potential include nonaqueous phase
leachate such as that which has been generated at the Love Canal and Hyde Par It
Landfills, unused liquid herbicide solutions such as herbicide orange, and
possibly still bottoms from herbicide production.
4.7.2 Technology Performance Evaluation
The plasma arc system has been tested using several liquid feed materials
including carbon tetrachloride (CC1,), polychlorinated biphenyls (PCBs), and
methyl ethyl ketone (MEK). It has not been tested on wastes or other materials
contaminated with TCDD. However, because of the structural similarity between
TCDD and PCBs, the data presented should provide some indication as to the
potential of this technology towards destroying TCDD.
4-67
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TABLE 4.7.1. CARBON TETRACHLORIDE TEST RESULTS
Parameter
Chlorine Mass Loading (Z)
Scrubber Effluent
CCl4(ppb)
mg/hr
Flare Exhaust
CC14 (ppb)
mg/hr
NOX
ppm(v/v)
Ibs/hr
CO
ppm(v/v)
Ibs/hr
HC1
mg/dscm*
kg/hr
Destruction Removal Efficiency
Test 1
35
1.27
2.29
0.83
12.1
106
1.02
48
0.28
(1)
(1)
99.99998
Test 2
40
5.47
9.85
0.43
4.9
92
0.69
57
0.26
137.7
0.25
99.99998
Test 3
35
3.26
5.87
0.63
7.2
81
0.02
81
0.37
247.7
0.44
99.99998
(1) sample taken was invalidated due to plugging of sampling apparatus
*mg/dscm " milligrams per dry standard cubic meter.
4-69
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TABLE 4.7.3. PCB TEST RESULTS
Run 1
Run 2
Run 3
Stack Gas Parameters
Total PCB, (1)
g/dscm* (2)
Total Dioxins,
g/dscm
Total Furans,
g/dscm
Total BaP,
g/dscm
0.013
0.013
0.076 (3)
0.26
0.18
0.46
0.32
0.43
1.66
0.45
3.0
0.011
0.13
0.30
2.8
Scrubber Effluent Parameters
Total PCB, ppb(l)
(2)
Total Dioxins, ppt
Total Furans, ppt
Total BaP, mg/L
1.56
0.06
5.8
1.5
0.04
2.15
4.7
259
399
0.92
9.4
0.01
1.35
1.35
2.0
Destruction Removal Efficiency
PCB, Percent DRE
(1)
(2)
>99. 99999
99.999999
99.99994
99.99997
>99.9999
99.999999
(1) These values are based upon mono-decachlorobiphenyl.
(2) These values are based upon tri-decachlorobiphenol.
(3) No tetra or penta dioxins were detected at 0.05 ng on a GL column,
except for run tl where 0.06 ng tetra dioxin was reported.
*g/dscm • grams per dry standard cubic meter
Reference: Kolak, et al., 1986.
4-71
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4.8 MOLTEN SALT DESTRUCTION
4.8.1 Process Description
The molten salt destruction process has been under development by
Rockwell International since 1969 (Edwards, 1983). The original intent was to
use the process to gasify coal. A variety of salts can be used, but the most
recent studies have used sodium carbonate (Na-CO-) and potassium carbonate
(K2C03) in the i,450°F to 2,200*F temperature range.
In addition to the Rockwell process, another molten salt process is under
development. The State of New Jersey in late 1982 issued a contract to the
Questex Corporation of New York to evaluate a mobile offsite earth
decontaminator (MOSED), a waste treatment unit based on the molten salt
destruction principle* A status report on the development of this device was
presented at the 1985 Hazpro Conference (Leslie, 1985).
As shown in a schematic of the Rockwell process (Figure 4.8.1), the waste
is fed to the bottom of a vessel containing the liquid salt along with air or
oxygen-enriched air. The molten salt is maintained at an average temperature
of 900°C (l,650°F). The high rate of heat transfer to the waste causes rapid
destruction. Hydrocarbons are oxidized to carbon dioxide and water.
Constituents of the feed such as phosphorous, sulfur, arsenic, and the
halogens react with the salt (i.e., sodium carbonate) to form inorganic salts,
which are retained in the melt. The operating temperatures are Low enough to
prevent NO emissions (Freeman, 1985; GCA, 1985; Edwards, 1983). Any gases
that are formed are forced to pass through the salt melt before being emitted
from the combustor. If particulates are present in the exhaust gases, a
venturi scrubber or baghouse may be used (GCA, 1985; Edwards, 1983).
Eventually, the build-up of inorganic salts must be removed from the
molten bed to maintain its ability to absorb acidic gases. Additionally, ash
introduced by the waste must be removed to maintain the fluidity of the bed.
Ash concentrations in the melt must be below 20 percent to preserve fluidity
(Edwards, 1983).
Melt removal c*n be performed continuously or in a batch mode.
Continuous removal is generally used if the waste feed rates are high. The
melt can be quenched in water and the ash can be separated by filtration while
4-73
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the salt remains in solution. The salt can then be recovered and recycled.
Salt losses, necessary recycle rates, and recycling process design are
strongly dependent on the waste feed characteristics (GCA, 1985; Freeman,
1985; Edwards, 1983).
>
Restrictive Waste Characteristics—
The ash content of the melt should be limited to 20 percent in order to
maintain fluidity for a reasonable per.od of time. The process becomes
inefficient and/or impractical for wastes of high ash content. Also, wastes
wj.th a low water content are destroyed more effectively.
Operating Parameters (Freeman, 1985; GCA, 1985)—
The following are typical parameters for the molten salt incinerator:
Waste Form Solid or Liquid Wastes of
Low ash and water contents
Operating Temperature 800 to 1000°C
(1500° to 1850°F)
Average Residence Time
Gas Phase 5 seconds
Solid (or Liquid Phase) Hours
Energy Requirements Fuel to burn waste
(if not combustible)
Electric power for blowers
4.8.2 Technology Performance Evaluation
Rockwell International has built two bench scale combustors (0.5 to 2
Ib/hr), a pilot plant (55 to 220 Ib/hr), and a portable unit (500 Ib/hr)
(Edwards, 1983). They have also built a 200 Ib/hr coal gasifier based on the
molten salt process.
Many wastes have been tested in the bench scale unit. Chemical warfare
agents GB, Mustard HD, and VX have been destroyed at efficiencies ranging from
99.999988 to 99.9999995 percent. Other chemicals that have been destroyed
using the molten salt combustion process include: chlordane, malathion, Sevin,
DDT, 2,4-0 herbicide, tar, chloroform, perchloroethylene distillation bottoms,
trichloroethane, tributyl phosphate, and PCBs (GCA, 1985; Edwards, 1983).
4-75
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TABLE 4.8.1. PCB COMBUSTION TESTS IN SODIUM-POTASSIUM-CHLORIDE-CARBONATE
MELTS [Edwards, 1983]
Temp
(°F)
1598
1526
1292
1643
1427
1427
Stochionetric
air
(Z)
145
115
160
180
125
90
Concentration
of KC1, NaCl
in melt
(wt Z)
60
74
97
100
100
100
Extent of PCB
destruction4
(Z)
>99. 99995
>99. 99995
>99. 99995
>99. 99993
>99. 99996
>99. 99996
Concentration
of PCB in
off-gas*
( g/m^
52
65
51
59
44
06
aPCBs were not detected in the off-gas, i.e., values shown are detection
limits.
Reference: GCA, 1985; Edwards, 1983.
4-77
-------
4.8.4 Process Status
Rockwell has constructed several molten salt units of varying sizes. The
company has conducted extensive tests in two sizes of units; bench-scale
«
combustors for feeds of up to 10 Ib/hr wastes, and a pilot-scale unit for
feeds of up to 250 Ib/hr of wastes (Freeman, 1985).
Several developments will be needed if molten salt combustion is to be
applied to dioxin-contaminated wastes. The 99.9999 percent ORE required by
the current RCRA regulations must be demonstrated for dioxins, and additional
testing with dioxin-contaminated wastes (both liquids and solids) needs to be
performed on a larger scale. Research to develop more economical construction
materials may also be required.
As indicated above, molten salt combustion is not currently practical for
the treatment of dioxin-contaminated wastes. Additional research and
development is required, but Rockwell has no plans for such further activity.
The status of the New Jersey MOSED unit is not known.
4-79
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WASTE (10* ORGANIC)
WASTF
^
AIR
WASTF
PUMP
AIR
COMPRESSOR
RECYCLE EDUCTOR
SOLIDS
SEPARATOR
OXIOIZER
T
SOLIDS
CO
EXPANDERJl
k TURBINE ^-^
HIGH PRESSURE
LI QUID-VAPOR
SEPARATOR
EXPANDER
TURBINE
WATER
STEAM
GENERATOR
LOW PRESSURE
LIQUID-VAPOR
SEPARATOR
HIGH
PRESSURE
STEAM
CLEAN
WATER
Figure 4.9.1.
Process schematic for supercritical oxidation of an aqueous waste with
a heating value of 1750 Btu/lb (Modeli, et al., 19U4J.
-------
4.9.2 Technology Performance Evaluation
Modar has built and tested bench scale supercritical water reactors for
destruction of urea, chlorinated organips, and dioxin-containing wastes.
•t
Skid-mounted, transportable systems with a capacity of 50 gal/day have been
designed as well as larger-scale stationary units.
A reactor, constructed of Iconel 628 and measuring 19.6 inches long with
an inside diameter of 0.88 inches, was used to investigate urea destruction
(GCA, 1985; GCA, 1984). Additional tests of the supercritical water oxidation
process were conducted using a similarly constructed Haste Hoy C-276 reactor
with dimensions of 24 inches in length and 0.88 inch inside diameter (GCA,
1985; GCA, 1984). Tests on chlorinated organics were performed with this
reactor. Table 4.9.1 summarizes the compositions of the various waste feeds
used in the test runs. Liquid influents and effluents were analyzed for total
organic carbon TOC by GC/MS (Modell, 1982). Gaseous effluents were analyzed
by GC for low molecular weight hydrocarbons (Modell, 1982). The results of
these analyses and the calculated destruction and removal efficiencies (DREs)
are shown in Table 4.9.2. Chlorinated dibenzo-p-dioxins were searched for
specifically, but none were found in the effluents.
A laboratory-scale trial burn was conducted using a feed consisting of
synthesized dioxin added to trichlorobenzene (at 100 ppm concentrations)
(Killiley, 1986). According to Modar, the process achieved greater than six
nine's ORE based on the analytical detection limits for gas and liquid
effluents (Killiley, 1986). Modar has performed studies on dioxin-
contaminated soils for private clients, including a field demonstration using
their pilot scale unit for the New York Environmental Conservation Department
(Killiley, 1986). Although the results of these tests are not available for
release at this time, the DREs for TCDD were reportedly greater than 6 nines
(Killiley, 1986).
4.9.3 Costa of Treatment
The most significant operating cost factor is the cost of oxygen consumed
(GCA, 1985). Although compressed air can be used as the source of oxygen, the
cost of power as well as the high capital cost of appropriate compressors has
4-83
-------
TABLE 4.9.2. SUMMARY OF RESULTS: OXIDATION OF ORGANIC CHLORIDES
|M^
11
1.1
26,700.
2.0
99.993
100.
25.58
59.02
—
—
••~
876.
.023
(2) 99.997
—
--
—
18
—
5
—
—
~~
Analysis
• *oo
, oxf~^-<2
. o^Q — Q
«?«
13
1.1
24,500.
6.4
99.975
100.
37.10
46.86
—
— -
^~
748.
<.028
99.996
—
--
—
18
<4.
<5.
0.2
0.3
~—
>
>•«
14
1.1
38,500.
3.5
99 .991
100.
10.55
70.89
—
~
^^
775.
.032
99.996
—
—
14
—
—
6
—
—
12
15
1.3
33,400.
9.4 .
99.97
100.
19.00
70.20
~
--
^•»
481.
.036
99.993
—
— •
—
—
— —
—
—
36
••—
4-85
-------
TABLE 4.9.3. MODAR TREATMENT COSTS FOR ORGANIC
CONTAMINATED AQUEOUS WASTES3
Waste capacity
gal /day
5,000
10,000
20,000
30,000
ton/day
20
40
80
120
Processing cost
$/galb
$0.75 -
$0.50 -
$0.36 -
$0.32 -
$2.00
$0.90
$0.62
$0.58
$/tonb
$180 -
$120 -
$ 86 -
$ 77 -
$480
$216
$149
$139
*Based upon an aqueous waste with 1800 Btu/lb heating
value and inorganic solids of between IX and 10Z.
''Does not include energy recovery value of approximately
$0.05 per gallon.
Source: Sieber, 1986.
4-87
-------
8«w«* Adapted from
"•"»»••* Laboratory
figure 4.10.1.
Schematic diagram t%e
Con.u™ .lnnt
4-89
op.r.tton
-------
»t*C«
OMNCNIR
ICMMfft »»«rt
MMIUkTO* *« TANK
1
MLfT •*»***
COOTAMMIf NT MOOWlt
Figure 4.10.2. Schematic of large-scale off-gas
treatment system (Jitzpatrick, 1984),
4-91
-------
costs such as labor and annual equipment charges (Oma, et al., 1983).
Specifically, for variations in manpower levels, power source costs, and
degree of heat loss it was determined that the costs for TRU waste
vitrification ranges from 160 to 360 $/m to vitrify to a depth of
5 meters. These costs are a function of*many variables but are most sensitive
to variations in the amount of moisture in the soil and the cost of electrical
power in the vicinity of the process. Figure 4.10.3, developed by PNL,
illustrates the variation in total costs as a function of both electrical
power costs and moisture content of TRU soil experimentally treated. The
vertical line represents the value beyond which it is more cost effective to
lease a portable generator.
Recently, PNL has assessed the cost implications for ISV treatment of
three additional waste categories; i.e., industrial sludges and hazardous
waste (PCB) contaminated soils at both high and low moisture contents (Buelt,
J., 1986). Representatives at PNL indicated that for industrial sludges with
moisture contents of 55 to 75 percent (classified as a slurry), the total
costs would range from 70 to 130 $/m . Treatment of high (greater than 25
percent) moisture content hazardous waste-PCB contaminated soil would cost
3 3
approximately 150 to 250 t/m versus costs of 128 to 230 i/m for low
(approximately 5 percent) moisture content PCB contaminated soil.
As these recent data and past TRU waste cost data suggest, the moisture
content of the contaminated material is particularly important in influencing
treatment costs. High moisture content increases both the energy and length
of time required to treat the contaminated material. Furthermore, PNL
representatives suggest that treatment costs are also influenced by the degree
of off-gas treatment required for a given contaminated material (i.e., ISV
application to hazardous chemical wastes will likely not require as
sophisticated an off-gas treatment system as would TRU waste treatment).
4-93
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4.10.4 Process Status
As briefly indicated above in the "Cost" discussions, PML has recently
assessed the treatment and costs associated with hazardous waste contaminated
soils (Buelt, J., 1986). During the summer of 1985, tests were conducted for
the Electric Power Research Institute (EPRI) on PCS contaminated soil. Note
that while the draft report on these tests has been completed, it has not been
published and/or made available to date. However, an EPRI project summary
publication, dated March 1986, entitled "Proceedings: 1985 EPRI PCB Seminar"
(EPRI CS/EA/EL 4480) has recently been made available to EPRI members.
Preliminary results suggest that a destruction/removal efficiency (ORE) of six
to nine nines was achieved from the off-gas treatment system overall, and that
a vitrification depth of 2 feet was achieved. Additional information will
soon be available to the public. PNL expects to continue with research in the
area of hazardous waste soils.
4-95
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Brown, William. Chemical Waste Management, Inc. Telephone Conversation with
Lisa Farrell, GCA Technology Division, Inc. March 28, 1986.
Buelt, J.L., et al. Battelle Memorial Institute, Pacific Northwest
Laboratories, Richland, Washington. An Innovative Electrical Technique
for In-Place Stabilization of Contaminated Soils. In: Proceedings of
the American Institute of Chemical' Engineers 1984 Summer Meeting in
Philadelphia, Pennsylvania. 1984.
Buelt, J.L. Battelle Memorial Institute, Pacific Northwest Laboratories,
Richland, Washington. Telephone Conversation with Michael Jasinski, GCA
Technology Division, Inc. 1986.
California State Air Resources Board. Technologies for the Treatment and
Destruction of Organic Wastes as Alternatives to Land Disposal. 1982.
Carnes, Richard A., and Frank C. Whitmore. Characterization of the Rotary
Kiln Incinerator System at the U.S. EPA Combustion Research
Facility (CRF). Hazardous Waste, 1(2): 225-236. 1984.
Carnes, Richard A. U.S. EPA, Combustion Research Facility. U.S. EPA
Combustion Research Facility Permit Compliance Test Burn. In:
Proceedings of the Eleventh Annual Research Symposium on Incineration and
Treatment of Hazardous Waste, sponsored by U.S. EPA-HWERL. Cincinnati,
Ohio, April 29-May 1, 1985. EPA/600/9-85/028. September 1985.
Carnes, Richard A. U.S. EPA, Combustion Research Facility. Telephone
Conversation with Lisa Farrell, GCA Technology Division, Inc.
January 29, 1986.
Chang, Daniel P.Y., and Nelson W. Sorbo. University of California, Department
of Civil Engineering. Evaluation of a Pilot Scale Circulating Bed
Combustor with a Surrogate Hazardous Waste Mixture. In: Proceedings of
the Eleventh Annual Research Symposium on Incineration and Treatment of
Hazardous Waste, sponsored by U.S. EPA-HWERL. Cincinnati, Ohio,
April 29-May 1, 1985. EPA/600/9-85/028. September 1985.
Chemical Engineering. New Units Give Boost to Sludge Incineration.
July 9, 1984.
Clark, W.D., J.F. La Fond, O.K. Moyeda, W.F. Richter, W.R. Seeker, and
C.C. Lee. Engineering Analysis of Hazardous Waste Incineration; Failure
Mode Analysis for Two Pilot Scale Incinerators. In: Proceedings of the
Eleventh Annual Research Symposium on Incineration and Treatment of
Hazardous Waste, sponsored by U.S. EPA-HWERL. Cincinnati, Ohio,
April 29-May 1, 1985. EPA/600/9-85/028. September 1985.
Daily, Philip L. Shirco Infrared Systems, Inc. Performance Assessment of
Portable Infrared Incinerator. Storage & Disposal. 1985.
4-97
-------
Freestone, F., R. Miller, and C. Pfrommer. Evaluation of Onsite Incineration
for Cleanup of Dioxin-Contaminated Materials. In: Proceedings of the
International Conference on New Frontiers for Hazardous Waste Management,
sponsored by: U.S. EPA-HWERL, NUS Corporation, National Science
Foundation, and American Academy of Environmental Engineers. Pittsburgh,
Pennsylvania, September 15-18, 1985. EPA/600/9-85/025. September 1985.
4
Freestone, Frank. U.S. EPA-HWERL, Edison, New Jersey. Telephone Conversation
with Lisa Wilk, GCA Technology Division, Inc. August 5, 1986.
GA Technologies, Inc. Brochure: Circulating Bed Waste Incineration. 1984.
GCA Technology Division. Screening to Determine the Need for Standards of
Performance for Industrial and Commercial Incinerators. Prepared for the
U.S. EPA, Office of Air Quality Planning and Standards, under EPA
Contract Nos. 68-02-2607 and 68-02-3057. January 1979.
GCA Technology Division. Draft Final Report: Technology Overview -
Circulating Fluidized Bed Combustion. Prepared for U.S. EPA, Office of
Research and Development, under EPA Contract No. 68-02-2693,
GCA-TR-81-91-G. August 1981.
GCA Technology Division. Utilization of Non-Land Disposal Alternatives to
Handle Superfund Wastes. Prepared for the U.S. EPA, Office of Solid
Waste, Waste Management and Economics Division. July 25, 1984a.
GCA Technology Division. Final Report: Technical Assessment of Treatment
Alternatives for Wastes Containing Halogenated Organics. Prepared for
U.S. Environmental Protection Agency, Office of Solid Waste, Waste
Treatment Branch, under EPA Contract No. 68-01-6871, Work Assignment
No. 9. GCA-TR-84-149-G. October 1984b.
GCA Technology Division. Detailed Review Draft Report: Identification of
Remedial Technologies. Prepared for U.S. EPA, Office of Waste Programs
Enforcement, under EPA Contract No. 68-01-6769, Work Assignment
No. 84-120. GCA-TR-84-109-G-(0). March 1985.
Gregory, R.C. Rollins Environmental Services, Inc. Design of Hazardous Waste
Incinerators. Chemical Engineering Progress. April 1981.
Hazardous Waste Consultant. Stabilizing Organic Wastes: How Predictable Are
The Results? Volume 3, Issue 3, Pages 1-18 to 1-19. May/June 1985.
Hazardous Materials Intelligence Report. EPA Incineration Test, Public
Hearing on AL Waste Law Amendments. December 6, 1985a.
Hazardous Materials Intelligence Report. EPA to Issue Permits for Ocean
Incineration Tests. December 6, 1985b.
Hazardous Materials Intelligence Report. Texas Company Markets Transportable
Infrared Incinerator. January 10, 1986a.
4-99
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Johanson, Kenneth. Shirco Infrared Systems, Inc., Dallas, Texas. Telephone
Conversations with Lisa Farrell, GCA Technology Division, Inc.
February 20, 1986; April 1, 1986; April 3, 1986; April 23, 1986; and
May 5, 1986.
Josephson, Julian. Supercritical Fluids. Environmental Science &
Technology. October 1982.
Killiley, William. Modar, Inc. Telephone Conversation with Lisa Farrell, GCA
Technology Division, Inc. February 25, 1986.
Kolak, Nicholas P., Thomas G. Barton, C.C. Lee, and Edward F. Peduto. Trial
Burns - Plasma Arc Technology. In: Proceedings of the U.S. EPA Twelfth
Annual Research Symposium on Land Disposal, Remedial Action.
Incineration and Treatment of Hazardous Waste. Cincinnati, Ohio.
April 21-23, 1986.
Krogh, Charles. CH2M Hill. Memorandum to Katie Biggs (EPA VII), Steve
Wilhelm (EPA/VII), and John Kingscott (EPA/HQ). Re: Technical Briefing
on the Mobile Incinerator Project. June 7, 1985.
Lee, Anthony. Technical Resources, Inc. Analysis of Technical Information to
Support RCRA Rules for Dioxins-containing Waste Streams. Final Draft
Report submitted to Paul E. des Hosiers, Chairman, U.S. EPA - Dioxin
Advisory Group. July 31, 1985.
Lee, Kenneth W., William R. Schofield, and D. Scott Lewis. Mobile Reactor
Destroys Toxic Wastes in "Space". Chemical Engineering. April 2, 1984.
Leslie, R.H. Development of Mobile Onsite Earth Decontaminator, In:
Proceedings of the Hazardous '85 Conference, Baltimore, Maryland.
May 1985.
Materials Characterization Center (MCC). Nuclear Waste Materials
Handbook—Waste From Test Methods. Department of Energy, Washington,
D.C. DOE/TIC-11400. 1981.
Marson, L. and S. Unger. Hazardous Material Incinerator Design Criteria,
prepared by TRW, Inc. for the U.S. EPA Office of Research and
Development, EPA-600/2-79-198. October 1979.
McCormick, Robert. ENSCO, Inc. Telephone Conversation with Lisa Farrell, GCA
Technology Division, Inc. May 7, 1986.
McGaughey, J.F., M.L. Meech, D.G. Ackerman, S.V. Kulkarni, and M.A. Cassidy.
Radian Corporation. Assessment of Treatment Practices for Proposed
Hazardous Waste Listings F020, F021, F022, F023, F026, F027, and F028.
Prepared for U.S. EPA under EPA Contract No. 68-02-3148, Work Assignment
No. 10. September 1984.
M.M. Dillon, Ltd. Destruction Technologies for Polychlorinated Biphenyls
(PCBs). Prepared for Environment Canada, Waste Management Branch. 1983.
4-101
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Ross, R.W., II, T.H. Backhouse, R.N. Vogue, J.W. Lee, and L.R. Waterland.
Acurex Corporation, Energy & Environmental Division, Combustion Research
Facility. Pilot-Scale Incineration Test Burn of TCDD-Contaminated
Toluene Stillbottoms from Trichlorophenol Production from the Vertac
Chemical Company. Prepared for U.S. EPA, Office of Research and
Development, Hazardous Waste Engineering Research Laboratory, under EPA
Contract No. 68-03-3267, Work Assignment 0-2. Acurex Technical Report
TR-86-100/EE. January 1986.
Roy F. Weston, Inc. and York Research Consultants. Times Beach, Missouri:
Field Demonstration of the Destruction of Dioxin in Contaminated Soil
Using the J.M. Huber Corporation Advanced Electric Reactor.
February 11, 1985.
SCA, Inc., Customer Service Department. Telephone Conversation with Lisa
Farrell, GCA Technology Division, Inc. Re: PCBs Incineration Costs.
May 9, 1986.
Schofield, William R., Oscar T. Scott, and John P. DeKany. Advanced Waste
Treatment Options: The Huber Advanced Electric Reactor and The Rotary
Kiln Incinerator. Presented HAZMAT Europa 1985 and HAZMAT
Philadelphia 1985.
Shih, C.C., et al. Comparative Cost Analysis and Environmental Assessment for
Disposal of Organochloride Wastes. Prepared by TRW, Inc. for the U.S.
EPA Office of Research and Development, EPA-600/2-78-190. August 1978.
Shirco Infrared Systems, Inc. Dallas, Texas. Brochure: Shirco Incineration
System - Process Description and Component Description. 1985.
Sickels, T.W. ENSCO's Modular Incineration System: An Efficient and
Available Destruction Technique for Remedial Action at Hazardous Waste
Sites. Preprinted Extended Abstract of Paper Presented Before the
Division of Environmental Chemistry, American Chemical Society, 191st
National Meeting, New York, New York: Vol 26, No. 1. April 13-18, 1986.
Sieber, F. Modar, Inc. Correspondence with N.F. Surprenant, GCA Technology
Division, Inc. May 29, 1986.
Smith, Robert L., David T. Musser, Thomas J. DeGrood. ENRECO, Inc. In Situ
Solidification/Fixation of Industrial Wastes. In: Proceedings of the
6th National Conference on Management of Uncontrolled Hazardous Waste
Sites, Washington, D.C. November 4-6, 1985.
Spooner, Philip A. Science Applications International Corporation (SAIC).
Stabilization/Solidification Alternatives for Remedial Action.
Strachan, D.M., R.P. Turcotte, and B.O. Barnes. MCC-1: A Standard Leach Test
for Nuclear Waste Forms. Pacific Northwest Laboratory, Richland,
Washington. PNL-SA-8783. 1980.
4-103
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SECTION 5.0
NONTHERMAL TECHNOLOGIES FOR LISTED DIOXIN WASTES
This section reviews nonthermal technologies for treating dioxin wastes.
Several of the technologies involve the addition of chemical reagents to
degrade or destroy dioxin, e.g. chemical dechlorination, ruthenium tetroxide
degradation, and degradation using chloroiodides. Two technologies,
ultraviolet (UV) photolysis and gamma ray radiolysis, involve the application
of electromagnetic radiation to break down dioxin and other contaminants.
There is also a subsection covering biodegradation. The remaining two
treatment technologies discussed, solvent extraction and stabilization/
fixation, are not destructive technologies, but rather represent pretreatment
and temporary measures, respectively, for managing dioxin wastes.
The technologies that are included in this section are not evaluated in
the same manner as the thermal technologies. Thermal technologies are
primarily evaluated on the basis of six nines ORE, where DRE is a function of
the concentration of a contaminant in the exhaust gas from the process. With
nonthermal treatment there are generally no exhaust gases of significance.
There are, however, other treatment effluents and residues which are major
potential sources of dioxin emissions. Since EPA has proposed that these
residues must contain less than 1 ppb of CDDs or CDFs in order to be land
disposed, this will be the main criterion on which these technologies will be
judged.
5-1
-------
The use of the priority pollutant, naphthalene, proved to be a source of
concern. Subsequent dechlorination processes were designed to utilize
alternate reagents. For example, the Acurex Waste Technologies Corporation
(now Acurex Corporation) developed a process (Dillon, 1982; desRosiers, 1983;
«
Ueitzman, 1986) which used a sodium-based reagent, prepared from proprietary
but nonpriority pollutant constituents (Miille, 1981). The system operates by
mixing filtered, PCS contaminated oil with the sodium-based reagent in
processing tanks where the chemical reaction occurs. The two streams leaving
the reactor are a treated oil containing no PCBs and a sodium hydroxide
effluent. The entire PCB destruction process was designed to occur under an
inert nitrogen atmosphere, however, Acurex found that this inert nitrogen
blanket was not essential (Weitzman, 1986).
The SunOhio PCBX process, approved by USEPA in 1981, is a continuous,
closed loop process utilizing a proprietary reagent to strip chlorine atoms
from PCB molecules, converting the PCBs to metal chlorides and polyphenyl
(polymer) compounds (Dillon, 1982; Jackson, 1981; SunOhio, 1985).
PCB-contaminated mineral/bulk oils are first treated to remove moisture and
gross contaminants. The PCB-contaminated oil is then mixed with the
proprietary reagent and sent to the reactor where PCB destruction occurs. The
mixture is then centrifuged, filtered, and vacuum-degassed. Effluent streams
include treated oil, and polyphenyl/salt residues. The latter are solidified
and then typically sent to a landfill. The entire system is mobile, as it is
mounted on 40-foot tractor trailers. SunOhio commercially operates five
mobile units.
Only limited information has been found relating to the PPM process;
however, more is expected in the near future. From the available information,
this mobile process destroys PCB contaminated oil through the aid of a
proprietary sodium reagent (M. M. Dillon, 1982; des Hosiers, 1983). The
reagent is added to the contaminated oil and left to react. The solid polymer
formed by the reaction is filtered out of the oil. While this polymer is
reportedly a regulated substance, it has been found to contain no PCBs and can
readily be disposed of (M. M. Dillon, 1982). PPM currently has under
development a dechlorination process designed to work on soils. However, no
information is available on the process (personal conversation with
L. Centofanti, PPM).
5-3
-------
5.1.2 Technology Performance Evaluation
The Acurex process, while only applicable to contaminated PCB oils, has
been extensively evaluated and is now commercially available via Chemical
*
Waste Management (Weitrman, 1986). Tests'by Acurex, during an EPA
demonstration in the early 1980's, proved that this technology is effective in
treating PCB-contaminated oils containing approximately 1,000 ppm to
10,000 ppm (IZ)—reducing the PCB concentration to below detectable limits,
about 1 ppm (Weitzman, 1982).
The SunOhio PCBX process has and will continue to be used only on liquid
hydrocarbon streams (i.e., oil). The process cannot be used to treat
contaminated soils. At present no tests have been performed on 2,3,7,8-TCDD,
and it appears that this technology will continue to be used only on PCB
contaminated oils or fluids (SunOhio, 1984). This process has reduced PCB
contaminated transformer oil from 500 ppm to below detectable limits (1 ppm)
in just one pass through the system (Weitzman, 1982). By passing a
contaminated oil through the system three times, it is believed that the PCB
concentration can be reduced from 3,000 ppm to below 2 ppm [Dillon, 1982;
Jackson, 1981].
Performance data regarding the Goodyear process are limited. However,
available information indicates that this process is capable of treating oils
containing 300 to 500 ppm PCBs down to less than 10 ppm (Weitzman, 1982;
Berry, 1981). The contaminated transformer or heat transfer oil is purified
to this level within approximately 1 hour at ambient temperature. Like the
Acurex/Chemical Waste Management and SunOhio dechlorination processes, the
Goodyear process has only been demonstrated to be applicable to treatment of
PCB-contaminated oils.
The "APEG-type" processes have been laboratory and, in select situations,
field tested on PCBs and 2,3,7,8-TCDD-contaminated soil samples (Klee, A., et
al., 1984; Peterson, R., et al., 1985 and 1986; Rogers, C. J., et al., 1985;
Rogers, C. J., 1983). The APEG reagents used in these experiments have varied
over the several recent years of research from the NaPEG-type, sodium-based
reagents used in PCB destruction, to the KPEG-type, potassium-based reagents
proven more efficient in 2,3,7,8-TCDD-type destruction.
5-5
-------
TABLE 5.1.1.
SUMMARY OF DATA SHOWING PERCENT REMOVAL OF TCDD
FROM CONTAMINATED SOILS USING APEG DECHLORINATION PROCESS
(Klee, A. et.al., 1984).
Days after
application
7 days
28 days
Tim her line*
K-400
45*
35Z
K-120
46*
38Z
Denny
K-400
nmc
12Z
K-120
5U
52
alnitial TCDD content equalled 277 28 ppb.
Initial TCDD content equalled 330 33 ppb.
£
not * not measured
TABLE 5.1.2. SUMMARY OF DATA SHOWING PERCENT REMOVAL OF TCDD
FROM CONTAMINATED SOIL AT DENNY FARM
(Klee, A., et. al., 1984)
Days after
application
1 day
7 days
14 days
21 days
28 days
Denny Farm Soil3
K-400b
82
19%
16Z
25Z
22Z
KM-350
15Z
27Z
36Z
422
43Z
a The anomalies in the apparent decrease of the TCDD level of K-400 treated
sample at day 14 was found not to be statistically significant.
b K-400 reagent used in these experiments (vs. those shown in previous
Table 5.1.1) was prepared from KOH pellets instead of a 66Z aqueous KOH
solution.
5-7
-------
Additionally, it should be noted that during the summer of 1985,
APEG-type reagents were tested by the U.S. EPA at the Shenandoah Stables
dioxin-contaminated site to evaluate the dechlorination potential of these
reagents on 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) under field
*
conditions (Rogers, C. J., 1985). Results of these tests were not as
promising as in the past using APEGs in the laboratory. Specifically, the
APEG reagents were deactivated due to the fact that APEG is moisture
sensitive. The soil moisture at Shenandoah was determined to be on the order <
of 18 to 21 percent by weight. These results, while not favorable, did point
out that APEGs are extremely hygroscopic and that contact with moisture will
eventually result in the deactivation of the APEG reagent.
Finally, results of the use of the Sea Marconi CDP-process are presented
in Figure 5.1.1 and Table 5.1.5. Figure 5.1.1 shows that, at least in the
beginning, the disappearance of 2,3,7,8-TCDD from the reaction mixture is
linear with respect to time (Tundo, P., et al., 1985). The figure also
indicates that mixtures containing higher weight PEG* promote a much more
rapid decomposition of TCDD than mixtures containing lower weight PEGs. When
a PEG with a molecular weight of 6,000 is used (square data points), greater
than 99 percent decomposition of TCDD occurs in 30 minutes, while the use of a
PEG with a molecular weight of 1,500 (circular data points) requires over two
hours for an equivalent level of degradation. However, the reaction rate is
also a function of temperature, and the reaction using PEG 6000 was carried
out at 85°C versus 50°C for the PEG 1500 reaction. Therefore, based on
the data presented in Figure 5.1.1, it is difficult to assess the full effects
of higher molecular weight PEGs.
The data in Table 5.1.5 show the effect of temperature and different
mixtures of reagents on the decomposition of TCDD. The first set of data
represents the same conditions (PEG 6000 at 85°C) as those used to generate
the square data points in Figure 5.1.I. As already mentioned, these
conditions result in rapid decomposition of TCDD. The second set of data
points was generated using a smaller quantity of PEG 6000 and adding a butyl
ether compound to the reaction mixture. With this combination of reagents,
greater than 99.9 percent decomposition of TCDD occurred in 30 minutes. For
the third set of data, the reaction temperature was only 20°C, and the
decomposition of TCDD was much slower than for all of the other uses. Only
50 percent decomposition occurred in 192 hours.
5-9
-------
TABLE 5.1.5. DEGRADATION OF 2,3,7,8-TCDD UNDER DIFFERENT CONDITIONS
USING THE CDP-PROCESS (Tundo, P. et al, 1985)
REAGENTS (g)
IPEG 6000
K CO
Na2°2
(2.1)
(0.5)
(0.4)
TEMPERATURE (°C) TIME (h)
85 0.5
1.0
1.5
2.0
DECOMPOSITION (%)
99.4
99.6
99.75
>99.9
(PEG 6000
K.CO,
2 3
Na 0
Buu(cH CH 0)
IPEG 6000
K.CO,
2 3
Na2°2
(1.3) 85 0.5 >99.9
(0.5)
(0.2)
2H (0.2)
(1.8) * 20 72 30
(0.4) 192 50
(0.2)
without n-decane: after homogenization at 80°C the reaction was
solidified by cooling and kept at 20*C;
5-11
-------
TABLE 5.1.6. PRELIMINARY ECONOMIC ANALYSIS OF
IN SITU AND SLURRY PROCESSES
(Peterson, R.L., et al., 1985)
Cost, $/ton soil
Cost item In situ Slurry
Capital recovery 31 17
Setup and operation 65 54
Reagent 200 20
Total costs 296 91
-------
corresponding to the absorption of a quantum (photon) of light is 95 kilo
calories per gram-mole for UV light with a wave length of 3,900 angstroms and
is 142 kilocalories per gram-mole for a wave length of 2,000 angstroms.
Table 5.2.1 lists the dissociation energies for many common chemical
«4
bonds, along with the wavelength corresponding to the energy at which UV
photons will cause dissociation. As can be seen from the data in Table 5.2.1,
bond dissociation energies range from a low of 47 kcal/gmole for the peroxide
bond to a high of 226 kcal/gmole for the nitrogen triple bond. Of particular
interest in the case of dioxins is the C-C1 bond, with a dissociation energy
of 81 kcal/gmole, corresponding to an optimum UV wavelength of 353 run. For
reference purposes, this can be compared to the violet end of the visible
spectrum with a wavelength of about 420 nm. Thus, the UV radiation of
interest is in the electromagnetic spectrum close to visible light. This fact
is important because it means that sunlight, which radiates strongly in the
near visible wavelengths, might be a good source of UV photons which are
capable of degrading many molecules.
It is not surprising then, that the use of sunlight to degrade certain
toxic molecules has been noted by several researchers (des Hosiers,
P.E., 1983; Zepp, R.G., 1977, Esposito, M.P., 1980; Crosby, D.G., 1971). In
the case of 2,3,7,8-TCDD and other related compounds, the apparent mechanism
is that a terminal C-C1 bond is broken by UV radiation, thus "dechlorinating
the molecule" and converting it into less toxic compounds. (Note that this
reaction mechanism is very similar to that of chemical dechlorination; i.e., a
gradual and progressive substitution of the chlorine atoms.)
Efficient degradation appears to require the presence of a hydrogen
donor, because while UV can cause the cleavage of the C-C1 bond, recombination
can take place. However, if a hydrogen donor is present, it will also react
and replace the chlorine on the molecule. For example, several researchers
have noted that pure 2,3,7,8-TCDD and other chlorinated compounds degrade
slowly or not at all when placed on inorganic substrates,' but when suitable
hydrogen donors are present, degradation in sunlight can be rapid (Crosby,
1978).
UV has been commercially used to kill micro-organisms such as bacteria,
protozoa, viruses, molds, yeasts, fungi, and algae. Applications include
process and drinking water disinfection and sterilization, pretreatment prior
to reverse osmosis, and general algae and slime control.
5-15
-------
Recently, UV photolysis has been viewed as a potential large-scale
commercial mechanism to degrade toxic wastes. In attempting to obtain a
simple, inexpensive, and effective soil detoxification method, the University
of Rome evaluated the use of various cationic, anionic, and nonionic
«
surfactants to solubilize 2,3,7,8-TCDD in an aqueous solution prior to
photodegradation with sunlight or artificial UV light (Botre, C., 1978). Of
the four surfactants, 1-hexadecyclpyridium chloride or cetylpyridium chloride
(CPC) was found to be the most effective solubilizing agent, as well as having
the ability to enhance the subsequent photochemical degradation of
2,3,7,8-TCDD. Other solvents examined included sodium dodecyl sulfate (SDS),
polyoxyethylene sorbitan monoleate (Teewn 80) and methanol.
In 1975, Velsicol Chemical Corporation (Chicago) experimented with
removing 2,3,7,8-TCDD contamination from stockpiles of "Agent Orange", a
defoliant used in Viet Nam (Crosby, D.G., 1978; des Rosiers, P.E., 1983). The
2,3,7,8-TCDD molecule was extracted by using n-heptane as a solvent, and
exposing the solution to UV photolysis at 300-320 on wavelength. The process
resulted in a reduction from 1,900 ppb of 2,3,7,8-TCDD in the stockpiles to
less than 50 ppb in end products (Zepp, R.G., 1977; Esposito, M.P., 1980).
However, the process was not considered practical, and soon was discontinued.
Another UV degradation process that was developed in the early 1980s oy
the Atlantic Research Corporation was named Light Activated Reduction of
Chemicals (LARC). This process involves bubbling hydrogen into an aqueous
solution containing chlorinated hydrocarbons and then irradiating the solution
with ultraviolet light to declorinate the contaminants. Work on this process
was stopped several years ago for economic reasons (Kitchens, 1986).
More recently, three UV based processes have been described in the
literature which may be viable for large-scale degradation of 2,3,7,8-TCDD, as
well as other toxic chlorinated hydrocarbons. There are:
• the Syntex - IT Enviroscience process which involves UV photolysis
preceded by solvent extraction,
• UV photolysis in combination with ozonation, and
• UV photolysis preceded by thermal desorption.
Section 5.2.2 contains a discussion of the performance of these three
processes.
5-17
-------
100 c:
0.001
60
120 180 240
TIME—MIN
300
Figure 5.2.1. Rate of dioxin disappearance via UV irradiation
of hexane extract of dtoxin-contaminated still
bottoms (Exner, J.H., 1982).
5-19
-------
Ultraviolet (UV) Ozonolysia—
In 1979, it was shown (see Figure 5.2.2) by the California Analytical
Laboratories and the Carborundum Company that ultraviolet activated ozone
could successfully degrade 2,3,7,8-TCDD from the 1 ppb levels in solution to
less than 0.4 ppb (Edwards, B.H., 1983).* The procedure utilized to produce
the results shown in Figure 5.2.2 consisted of bubbling ozone gas through the
TCDD solution, which was then passed by UV lamps. The UV radiation lamps not
only degraded the 2,3,7,8,-TCDD directly, but integrated with ozone to enhance
the oxidation of the 2,3,7,8-TCDD. No information was available regarding the
waste products that were generated from this process.
UV ozonolysis has also been tested extensively in degrading PCBs down to
levels of I ppb. An "ULTROX" pilot plant at a General Electric (GE) plant in
Hudson Falls, New York, and another smaller installation at the Iowa
Ammunition Plant, Burlington, Iowa, have proven the technical feasibility of
this process on PCBs (Arisman, R.K., 1980; Edwards, B.H., 1983; Swarzgn,
E.M., 1982). Both of these plants mixed wastewater containing PCBs with
ozone, then exposed the mixture to UV radiation in a mixing tank.
Figure 5.2.3 shows a schematic of the pilot plant set up by GE to demonstrate
the ULTROX UV/ozone system for PCBs.
Another UV ozonolysis process is called the "Oxyphoton" process. The
process was reportedly capable of destroying a wide variety of toxic or
organic compounds including PCBs, chlorinated dioxins, DDT, and many types of
halogenated aliphatic and aromatic compounds (Worne, 1984). The process is
carried out in stainless steel reactors and is capable of treating 60 to
1,800 gallons per hour of waste fluids. Liquid waste containing a proprietary
catalyst is spray-atomized and premixed under pressure with oxygen containing
I to 2 percent ozone prior to passage through the high intensity ultraviolet
(UV) light.
One advantage to this vapor phase reaction process over the conventional
liquid phase UV light processes is the rapid disintegration of the waste.
Reaction rates are generally reported in the millisecond range. Presently,
the oxyphoton process is on the "back burner", possibly because of unfavoraole
economics. No research efforts have directly involved 2,3,7,8-TCDD
(Worne, 1984).
5-21
-------
UV lamp*
x~
o
o
o
o
o
i
•3
0
0
o
t"
0
o
o
O 0
V ^
"\l
o
o
o
o
s~
0
o
o
o
O 0
V _J*
"^1
o
o
o
o
o
Flow distributor
.1
«-
— — Wa«te water in
Spent Oj
Gatout
water
wpsra-
Treated
water out
Solid state
controlled
gear pump
Figure 5.2.3.
Schematic of top view of ULTROX pilot
plant by General Electric (Ozone sparging
system omitted) (Edwards, B. H., 1983).
5-23
-------
t
Purge Gas Makeup
Vent Gas
Treatment
Purge Gas
Purge Gas Recycle^
Contaminated
Thermal
Desorber
organic/water
vapors
Purge Gas,
Cooling, and
Scrubbing System
Treated Soil
e
v
"o
m
•9
v
Solvent Makeup
water condensate
i
Water
Treatment
aqueous discharge
UV System
Solvent purge
Figure 5.2.4.
Thermal desorption, solvent absorption/scrubbing,
UV photolysis process schematic (des Rosiers,
P. E., 1985).
5-25
-------
TABLE 5.2.3. DESIGN SPECIFICATIONS, CAPITAL, AND O&M COSTS FOR
40,000 AND 150,000 GPD ULTROX TREATMENT PLANTS
(50 ppm PCB feed-1 ppm PCS effluent)
SPECIFICATIONS
40,000 GPD 150,000 GPO
(151,400 LPD) (567,750 LEO)
Rtaetor Automated System Automated System
Dimension, Meters (LxNxH) 2.5 x 4.9 x 1.5 4.3 x 8.6 x 1.5
Net Voltm, Liters 14,951 56,018
UV Lamps; Number 65 W 378 1179
Total Power, lew 25 80
Oaone Generator
Dimensions, Meters (LxHXD) 1.7 x 1.8 x 1.2 2.5 x 1.8 x 3.1
kg Oaone/day 7.7 28.6
Total Energy required 768 2544
Own/day)
BOXEPUCf EQUIPMBir PRICES
40,000 GPD 150,000 GPD
Reactor $94,500 $225,000
Generator 30,000 75,000
mao. $124,566 TOIAL $300,000
0 t M Costs/Day
Oaone Generator Power $4.25 $15.60
UV Lamp Power 15.00 48.00
Maintenance
(Lamp Replacement) 27.00 84.20
Equipment Mortlzation
(10 Yrs • 10%) 41.90 97.90
Hanitoring Labor 'S-71 85.71
lOaL/DAJf $173,86 $331.41
Cost per 3785 Liters
(with monitoring labor) $4.35 $2.21
(without monitoring labor) $2.2Q _ $1.64
Source: Arlsman, R.IL and Mustek» R.C., 1980.
5-27
-------
reduction of soils to enhance optimum solvent/soil contact. Solvent recycling
allows reuse of expensive solvents and lowers concerns about disposal of
contaminant-containing solvents. Distillation or vacuum stripping are the
usual, methods for cleaning solvents. In either case, the result is a
f
concentrated volume of contaminant for eventual treatment or disposal
(Weitzman, 1984; Firestone, 1984).
EPA has developed a mobile soils washing system (MSWS) process for
extracting dioxin and other contaminants from soil. The EPA-developed MSWS
contains two basic components, as summarized below from IT Corporation, 1985
and as shown in Figure 5.3.1. These components are a Drum Screen Scrubber and
a Counter-Current Chemical Extractor. The Drum Screen unit automatically
loads previously excavated soil (particle sizes less than 1 inch) into the
system where it passes through high pressure streams of extractant solution
and a "soaking zone". The high pressure streams are designed to wash sands
and stones and to separate fines for further, high energy extraction. Sands
and stones are discharged from the Drum Screen and the fines are pumped
continuously into the Counter-Current Extractor, which consists of four
high-shear mixing chambers. As the fine soil (less than 2 mm) leaves each
chamber, it is separated from its solvent carrier before it enters the next
chamber. The design capacity of the MSWS ia 18 cubic yards of soil per hour.
5.3.2 Technology Performance Evaluation
Solvent extraction of chemical substances from soil has been commonly
used in the mining industry and has been demonstrated for extraction of
bitumen from tar sands (Cotter, 1981). Currently, the only full-scale process
that has attempted to use solvent extraction for dioxin molecules dealt with a
contaminated slurry. In this instance, the dioxin molecule (2,3,7,8-TCDD) was
extracted from distillation still bottoms at the Syntex Agribusiness facility
in Verona, Missouri. IT Enviroscience was contracted by Syntex to develop a
safe and effective method for removing approximately 7 kg of dioxin from about
4600 gal of waste (Exner, J.H., et al 1982). The treatment process designed
by IT involved the separation (extraction) of dioxin using a solvent, followed
by the photolytic dissociation of the carbon-halogen bond (see Section 5.2).
The solvent extraction phase of this project, as briefly described below,
involved several laboratory, miniplant, and scale-up operations.
5-29
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Specifically, IT Enviroscience performed teats on hexane, tetrachloro-
ethylene and o-xylene to determine which solvent would best remove the dioxin
molecule and, once removed, would allow the dioxin molecule to be effectively
degraded via the photolytic step. Their results showed that hexane extraction
«
of the subject wastes performed better overall than the other two solvents.
Based upon these results, a large-scale reactor vessel was designed and
constructed. In 1980, this reaction vessel processed several 160-gal batches
of the dioxin-containing waste resulting in a reduction of 2,3,7,8-TCDD-
concentrations of from 340 to 0.2 ppm via six hexane extractions.
IT Corporation, under the auspices of EPA, has also prepared additional
laboratory experiments to assess the suitability of the EPA Mobile Soils
Washing System (MSWS) for use in extracting dioxin from contaminated soils (IT
Corporation, 1985). The MSWS was designed to use water, or water with
non-toxic and/or biodegradable additives, as an extractant solution.
Non-hazardous additives are required because some residual solution will
always remain with the discharged soil. Because of this requirement, various
additives, such as surfactants and fuel oil, were evaluated in the laboratory
for the removal of dioxin from soil. Although laboratory results indicated
that 602 to over 902 of the 2,3,7,8-TCDD could be removed by the Soils Washing
System, in most cases (soils initially containing over 100 ppb of dioxin) the
washed soil would still contain residual dioxin in excess of the I ppb
guideline for decontamination. Similarly, while other experiments using Freon
and Freon-methanol combinations proved promising, the target residual dioxin
levels could not be achieved under the test conditions. It was concluded that
the major obstacle to removing dioxin from the soils was that dioxin binds
strongly to small soil particles. The soils on which the MSWS was tested were
from the Denney Farm in Missouri. These soils contained a high percentage of
extremely fine materials (33Z less than 5 microns, 262 less than 1 micron).
For materials with larger grain size, such as sands and gravels, the process
may be viable (IT Corporation, 1985).
In other laboratory experiments, both aqueous and organic solvents have
been tested on 2,3,7,8-TCDD-contaminated soil. In 1972, Kearney used a 1:1
hexane: acetone solvent solution on 2,3,7,8-TCDD (labeled with carbon
isotopes) in loamy sand and silty clay-loam soils. Electron-capture gas
5-31
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TABLE 5.3.1. SOLUBILIZATION OF TCDD (Botre, C., et al. 1978)
01
Solubilizer
MeOH
CPC
SDS
Tween 80
Experiments
Surfactant
concn
-
0.05M
0.05M
21 w/v0
on soila
Solubilized
TCDD
(I)
97.5
75.0
60.0
45.0
Experiments
Solubilized
Surfactant TCDD
cone (X)
100
0.02M 75
0.02M 71
U w/v0 72
on pure TCDD^
Surfactant
cone
-
0.05M
0.05M
21 w/vc
Solubilized
TCDD
(X)
100
78
75
73
•Each 90-g sample contained initially 6.3 yg of TCDD.
blnitial amount of TCDD: 40.90 pg.
cPercent weight to volume
-------
found in a soil matrix, io situ degradation is a more practical alternative.
In addition to the various modes of treatment, biodegradation can be effected
by a number of different types of micro-organisms. These include:
i
• aerobic bacteria;
• anaerobic bacteria;
• yeast; and
• fungi.
Following a discussion of the environmental degradation of TCDD, examples of
research on the application of several of these modes of treatment and types
of micro-organisms will be presented.
Degradation of 2,3,7,8-TCDD is a slow process, overall, in the natural
environment. Natural degradation is primarily due to biodegradation and
photochemical (UV) breakdown. A wide variety of half-lives have been
reported. The observed half-life for uncontrolled biodegradation of
2,3,7,8-TCDD has been reported as 225 and 275 days by the U.S. Air Force
(Young, 1976), although a separate analysis of the same data yielded
half-lives ranging from 190 to 330 days (Commoner, 1976). Another study
reported that half-life is affected by concentration, being greatly reduced at
high concentrations (Bolton, 1978). In fact, half-lives are probably
significantly greater than those reported, as most early research did not
account for the strong tendency for 2,3,7,8-TCDD to bind to soil particles.
Strongly bound 2,3,7,8-TCDD would not have been detected analytically and
biodegradation assumed incorrectly to be the cause of its absence.
Studies at Seveso, Italy indicate that the half-life of 2,3,7,8-TCDD
increases with its time in the soil, because of its tendency to became more
tightly bound to soil and organic matter (DiDominico, 1980). DiDominico found
that half-life calculations made 1-month after the Seveso accident predicted a
10 to 14-month half-life, but 17 months after the accident, the half-life of
2,3,7,8-TCDD in the soil had increased to more than 10 years.
In a study performed for the Air Force, 99 percent of the 2,3,7,o-TCDD
sprayed as a constituent of defoliants was still present 12 to 14 years after
application (Young, 1983). Although natural degradation seems to proceed
5-35
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TABLE 5.4.1. MICRO-ORGANISMS WITH KNOWN CAPABILITY FOR
DEGRADING 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN
Researcher
j
Nocardiopsis sp. Matsumura, 1983.
Bacillus negaterium Matsumura, 1983.
Beijerinckia B8/36* Klecka, 1980.
Pseudomonas, sp.b Klecka, 1979.
Biejerinckia, sp.* Klecka, 1980.
Phanerochaete chrysosporiumc Bumpus, et al., 1985,
'Oxidation of dibenzo-p-dioxin and several mono-, di-, and
trichlorinated dibenzo-p-dioxins was reported.
^Metabolism of dibeozo-p-dioxin was observed.
cWhite rot fungus.
5-37
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Ongoing Research—
There have been several more recent research projects concerning the
biodegradation of 2,3,7,8-TCDD and related compounds. Some of the more
significant ones are discussed below.
•*
White Rot Fungus (Bumpus et al., 1985)—
One method that has received a large amount of attention has involved the
study of the ability of the fungus, P. chrysosporium. to degrade recalcitrant
organopollutants, one of these being 2,3,7,8-TCDD. P. chrysosporium is a
lignin-degrading white rot fungus. This organism secretes a unique hydrogen
peroxide-dependent oxidase capable of degrading lignin, a highly complex,
chemically resistant, nonrepeating heteropolymer. The enzyme catalyzes the
formation of carbon-centered radicals which react with oxygen to initiate
oxidation. The low molecular weight aromatic compounds formed may then
undergo further modification or ring cleavage and eventually be metabolized to
carbon dioxide.
Several properties of P. chrysosporium make it a candidate for the
degradation of the more recalcitrant organopollutants such as 2,3,7,8-TCDD,
DDT, lindane and PCBs. First of all, the organism is able to degrade lignin,
chlorinated lignin and chlorinated lignin-derived by-products of the Kraft
pulping process. Secondly, low levels of pollutant (such as may exist in
contaminated soil) do not repress the production of enzymes required for
degradation. Thirdly, the organism is not substrate-specific and therefore
can attack and degrade a wide variety of structually diverse, recalcitrant
compounds. Finally, P. chrysosporium is a highly successful competitor in
nature, especially when the carbon source is lignin. Consequently,
competition by other organisms will be minimal if wood chips or sawdust are
added as a supplement to the waste material.
Results of laboratory tests using P. chrysosporium to degrade several
different compounds are shown in Table 5.4.2. In 10 ml cultures containing
14
1.25 nmoles of the C-labeled 2,3,7,8-TCDD substrate, 27.9 pmoles were
14
converted to C02 within 30 days and 49.5 pmoles within 60 days,
representing 4.96 percent metabolism. The remaining carbon atoms should have
either been incorporated into the organism or been present as intermediates in
the pathway between 2,3,7,8-TCDD and CO.. This conclusion is based on more
5-39
-------
detailed studies of the degradation of DDT which indicated that after 30 days
4 percent of the original DDT was evolved as CO,, when approximately
50 percent of the DDT had been degraded. In the case of DDT, greater than
99 percent degradation had occurred after 75 days.
f
Matsumura and Quensen (Quensen and Matsumura; 1983, Quensen, 1986)—
Research has been conducted at the Pesticide Research Center of Michigan
State University in which low concentrations of 2,3,7,8-TCDD were metabolized
by pure cultures of Nocardiopsis spp. and Bacillus megaterium. In these
experiments TCDD in solvent was added to flasks containing the pure cultures,
and after a period of 1 week, the contents were extracted and analyzed for
TCDD and metabolites.
Several conclusions were drawn from the study. One of these, as
substantiated by detail in Table 5.4.3, is that the choice of solvent used to
dissolve TCDD and add it to the culture medium has a significant effect on the
degradation of TCDD. The use of ethyl acetate or dimethyl sulfoxide (DMSO)
resulted in significantly higher degradation than when corn oil or ethanol
were used. Another conclusion that was drawn is that lowering of alternative
carbon sources increases the degradation of TCDD. The proportion of TCDD
metabolized by B. Megaterium increased dramatically when the amount of soybean
extract in the medium was reduced from 1.6 to 0.4 percent and ethyl acetate
was used as the solvent. Finally, analog-induced metabolism of TCDD by
including napthalene or dibenzofuran in the culture medium proved to be
ineffective.
In addition to the pure culture experiments, TCDD degradation in soil by
naturally occuring micro-organisms was also studied. TCDD was added to three
different types of soil and after 0, 2, 4, and 8 months of incubation, soil
samples were extracted and the levels of TCDD and metabolites were
determined. Very little metabolism of TCDD occured in any of the soils over
the 8 month period. This was true regardless of which solvent was used to add
TCDD to the soil system. Dimethyl sulfoxide, ethyl acetate and 10 percent
ethanol were used. They surmised that the resistance to degradation was due
to the fact that TCDD binds tightly to soil thereby limiting the rate of
cellular uptake.
5-41
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Kearney and PIinner (Kearney, 1984)—
A biological process Co detoxify 2,3,7,8-TCDD-contamiaated soils is being
evaluated at the Agricultural Research Center in Beltsville, Maryland. Work
is based on the observation that soil micro-organisms have the ability to
degrade highly chlorinated organica that have been pretreated with
ultra-violet (UV) radiation. Pretreatment with UV radiation removes chlorine
from the 2,3,7,8-TCDD molecule in the presence of a proton donor, and
the resulting dibenzo-p-dioxin molecule can then be biodegraded.
Laboratory studies have involved subjecting solutions of chlorinated
organics to UV radiation before adding them to the soil where biodegradation
could take place. Kearney and his colleagues have since experimented with a
prototype system that includes a 55-gallon stainless steel drum as a holding
tank and a commercial water purifying unit as the UV source. Kearney's
process focuses on cleaving the chlorine-carbon bonds in the chlorinated
organic compounds by the following procedures:
1. Expose a dilute aqueous solution (i. e., 1 ppm 2,3,7,8-TCDD) to
ultra-violet light (UV) for at least I hour
(Photo-Chemical Reaction).
2. While irradiating, bubble oxygen through the solution to speed up
the chlorine-carbon bond break up (Ozone Reaction).
3. Pour or spray irradiated solution over soil containing the test
micro-organisms (Biodegradation).
4. Determine the percent degradation by monitoring the amount of carbon
dioxide generated.
Recent studies (1981) have yielded the following results:
• 80 percent degradation of 2,4,5-T over I month;
• 80 percent degradation of PCB over I month;
5-43
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TABLE 5.A..4. SUMMARY OF RESEARCH PROJECTS ON BIODEGRADATION OF TCDD SURROGATES
wn
Keeearcher
University of
Illinois Medical
Center
Michigan State
Univeraity
Sybron Corpora! io
Saiam. Virginia
Croundwatar
Decontamination
Syatema. Inc..
Ualdwick, H.J.
Louie iana State
Univeraity,
Haaardoua Uaste
leaearch Center
Univeraity of
Minnesota
Compounds
tasted
2.4,i-TT2.4-D.
Chlorophenola;
research ha* bean
funded (or TCDD
2.4.5-T.
chlorinated
phenol a
n, 1,4-Dichlorophenol
acetone; methylene
chloride; n-butyl
alcohol; 1 ,4-dichloro-
diaenio-p-dioxin
(1,4-DCDD)
2,4-D and 2.4.J-T
2,4-D; J,5-
dichlorobantene
(J.5-DCI)
Type/Heme of
micro-organism
Paeudomonai
Cepacia. AC1100
unidentified
anaerobic
bacteria
Paeudomonaa
Stulieri
unknown
Paeudomonaa
(only identifiable
at the genua
level),
Alcaligenaa
eutrophus
plant aludge waa
the aource of
Type of
proceaa
micro-organiama
developed by
acclimation to
2,4.5-T in a
chemoatat; bacteria
alao can be applied
to aoil
would probably
involve the use
of an anaerobic
digeater
addition of microbes
in powdered form to
contaminated aite
activated sludge
ayatem from which
mlcro-organiama are
injected into
groundwatar
laboratory acale
batch reactora
reactora and
chemoatata
Performance Reference
up to 98X Ghoaal, et al..
degradation of 1985; Kilbane
2,4.5-T; et al.. 1985;
reduction of Tomasek and
2,4.5-T in aoil Chakrabarty,
from 1000 ppm 1985
to 10 ppm in
one week
capable of Tiedje, 1984
removing chlorine
atoma from the
chlorobentoate
molecule
lab teat ing hes Davia, 1984;
shown degradation Goldsmith, 1986
at 1.4-OCP
coocantrationa of
50-100 ppm
600-700 ppm of Macatsa, 198}
contaminant
reduced to leaa
than 6 ppb for
induatrial orgaoics
demonstrated toy end Mitre,
growth of micro- 1986
organisms uaing
2,4-D aa aola
carbon aourca
micro-organiama Kim and Heier,
were capable of 1986
utilising 2.4-D
•nil 1 5-DT.B IS
innoculating after
acclimation, the
Paeudomonaa apeciea
waa predominant
the aola aubatrate
at concentreciona
between 10ug/l end
100mg/l
-------
temperature, pH, and wood chip type and size (the substrate on which the
micro-organism is grown) will be varied to determine optimum growth conditions
(Sferra, 1986). After this, the white rot fungus will be tested in soil plots
containing TCDD. This means that the application of even a promising
4
micro-organism such as P. Chrysosporium to* actual waste will not occur for
several years, and only then if it proves to be successful in lab-scale
testing.
Several treatment methods described above have been demonstrated to be
applicable to the treatment of compounds that are similar to 2,3,7,8-TCDD,
such as chlorophenols and 2,4,5-T. They have not, however, been tested either
in the lab or the field on waste containing TCDD. In the case of the Sybron
Corporation work, it has been difficult to obtain samples of waste with which
to test their process in the lab, and it has also been difficult to test their
process at actual sites of TCDD contamination (Goldsmith, 1986). One of the
reasons for the difficulty in testing microbial processes on actual waste
sites is the issue of releasing genetically altered micro-organisms to the
environment.
In summary, the feasibility of biodegradation of 2,3,7,8-TCDD as a
treatment technology is still in question. Most investigations have been
performed in the laboratory, and the efficiency of a large scale treatment
process is unknown. There are many advantages associated with biotreatment
which make continued investigation advisable:
• The end products of complete biodegradation are nontoxic.
• Some processes may be accomplished onsite without soil excavation.
However, use of solvents which could potentially cause uncontrolled
mobilization of 2,3,7,8-TCDD must be avoided.
• Biological treatment appears to be effective at low 2,3,7,8-TCD
concentrations.
In addition, biotreatment could be coupled with other treatment processes to
make them both more efficient. For instance, the sodium polyethylene glycol
(NaPEG) process might be modified to in-situ treatment with the use of
micro-organisms to degrade the dechlorinating solvent and the residual
nonchlorinated and less chlorinated dibenzo-p-dioxins.
5-47
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TABLE 5.5.1 SUMMARY OF STABILIZATION PROCESSES FOR TREATING
HAZARDOUS WASTES (M. E. Tittlebaum, et al., 1985)
Classification
Cement-based
Lime-based or
pozzolanic
Thermoplastic
Thermosetting
polymer
Process sponsor
(process name)
Chemf ix
Stablex (Sealosafe)
Stabatrol (Terra-Tite)
Dravo Lime (Calcilox)
International Mill Service
IU Conversion Systems
Soil Recovery Systems
Sludgemaster
Werner and Pfleiderer
Southwest Research Inst.
(Sulfex)
Dow Chemical
Newport News Industrial
Stabilization agents
Cement, soluble silicates
Cement, fly ash
Cement, additives
Lime, additives
Lime
Lime
Lime
Lime, additives
Asphalt
Sulfur, modifiers
Polyesters, polyvinyls
Polyesters
Wastes
treated
Inorganics
Inorganics
Inorganics
FGD sludges
Metal slags
FGD sludges
Misc.
Misc.
Misc.
Misc.
Radioactive
Radioactive
Macro-
encapsulation
Se1f-cementing
Classification
Other
Environmental Protection
Polymers
TRW Systems
Sludge Fixation Technology
(Terra-Crete)
None specified
ARDECCA
Anschutz Corp. (Ansorb)
.Polyolefins Soluble
toxics
High-density polyethylene Misc.
Calcium sulfite or sulfate FGD sludges
Glass or ceramics
Proprietary
Clay-like material
Radioactive
Oil field
wastes
Misc.
5-49
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Inorganic Stabilizers—
Lopat Enterprises, Inc., of Asbury Park, New Jersey has developed a
product called "K-20" (McDaniel, 1983). K-20 is an inorganic mixture of at
least eight chemicals (McOaniel, 1983). No further information on its content
is available at this time. Lopat, Inc.', has a patent pending for K-20, which
was originally developed as a sealant for leaky basements (Goldensohn, 1983).
Recent investigations have shown evidence that dechlorination of chlorocarbon
contaminants may occur when K-20 is used as an encapsulant (Jiranders, 1984).
Pretreatment Requirements/Restrictive Waste Characteristics—
Stabilization is more frequently used for inorganics because organics
tend to interfere with the physical and chemical processes which are necessary
to bind the materials together (Spooner, 1985; Hazardous Waste Consultant,
1985; GCA, 1985). Wastes with greater than 10 to 20 percent organic content
are generally not recommended for treatment by stabilization.
5.5.2 Treatment Performance Evaluation
In 1985, the Solid Waste Research Division of the Disposal Branch of the
U.S. EPA sponsored a study to find the optimum mixture of asphalt and soil
cement that will stabilize 2,3,7,8-TCDD-contaminated soil (Vick, 1985). The
Portland Cement Institute and the Asphalt Institute will be reviewing the
work. In t!.' laboratory, stabilized soil underwent a leach test designed by
Battelle- Columbus Laboratory. A structural integrity test was suggested, but
not undertaken, because the soils are not expected to be subject to large
loads (even though strength tests are often an indication of durability).
JRB Associates, under the sponsorship of the U.S. EPA, conducted a field
test of cementious and asphaltic stabilization techniques in the State of
Missouri during 1985 (Vick, 1985; Ellis, 1986). The objectives of this
testing program included:
• evaluating the cost-effectiveness of the processes;
• developing optimum soil/stabilizer ratios and mixing conditions; and
• assessing the viability of successful field implementation.
5-51
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TABLE 5.5.2.
SOIL TYPES USED TO TEST PORTLAND CEMENT
AND EMULSIFIED ASPHALT/LIME STABILIZATION
TECHNIQUES
Site
Description
Soil type
TCDD
concentration
Minker
Piazza
Road
Sontag
Road
Residential area with
steep, sloping banks
that drain into a
nearby creek
Roadside material
Roadside material,
with considerably
greater percentage
of fine particles
(salt and clay) than
Piazza Road sample
Sandy loam
Sandy loam
Sandy silty
loam
700 ppb
640 ppb
32 ppb
(Technical Resources, Inc., 1985)
5-53
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The University of Maryland is currently performing controlled tests on the
ability of K-20 to decontaminate soils by encapsulation and/or dechlorination
using several chlorinated hydrocarbons including 2,3,7,8-TCDD. The U.S. EPA
in Cincinnati, Ohio is also running some tests on the ability of K-20 to
degrade 2,3,7,8-TCDD in soil. The results of the last two sets of tests may
help to evaluate the effectiveness of this encapsulation agent.
5.5.3 Costs of Treatment
To date, stabilization/fixation processes have not been fully tested and
cost effectiveness has not been documented. Organic wastes are generally more
practically disposed of via other technologies such as incineration. Fixation
becomes more cost-effective when the organic content of the waste is small,
thereby making incineration less feasible (e.g., 2,3,7,8-TCDD-contaminated
soils).
5.5.4 Process Status
Application of stabilization/fixation processes to organic wastes is a
relatively recent development, because organic wastes generally lend
themselves better to other treatment processes such as incineration or
biodegradation. Preliminary studies of contaminated soil suggest that an
emulsified asphalt-lime combination may be an effective interim remedial
measure for stabilization of dioxin-contaminated soils (Vick, 1985; Ellis,
1986).
Further studies plan to investigate the leaching potential and
performance of formulations using uncompacted soils (Vick, 1985). Future
goals are to develop a procedure whereby temporary in-situ stabilization could
be followed by soil/stabilizer removal and complete stabilization or fixation
at an offsite facility.
5-55
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Tests have also been done on synthetic wastes containing PCDDs. In one
of these experiments, 2,7-DCDD, when mixed with RuO, in a carbon
tetrachloride solution was determined to have a half-life of 215 minutes at
30°C; the half-life decreased to 38 minuses at 50°C. The oxidation of
2,3,7,8-TCDD proved to be a slower reaction; at 20°C it had a half-life of
560 minutes, while at 70°C the half-life decreased to slightly less than
15 minutes.
5.6.3 Costs of Treatment
Due to the current level of development of this technology, no cost data
are available. Major costs would be for energy to heat up the material to be
treated, and the cost of the chemical reagents. Pretreatment, extraction and
post-treatment costs are unknown.
5.6.4 Process Status
To date, this method of degrading TCDD has only been performed on a
laboratory scale. While these studies have shown that RuO, has the ability
to degrade 2,3,7,8-TCDD, the reaction end products have not been identified.
In addition, the only work reported has involved either the use of water or
CC1, as the solvent. Water is not very effective, and the application of
carbon tetrachloride to soil would not be environmentally acceptable. Thus,
the use of other solvents should be investigated.
This technology will require considerable work before it can be applied
in the field. The high cost of ruthenium tetroxide and the toxicity of
process residuals may limit application of this technology. Its potential (if
any) probably lies in the area of detoxification of glassware or purging of
industrial reactors (des Hosiers, 1986).
5.7 CHEMICAL DEGRADATION USING CHLOROIODIDES
5.7.1 Process Description
A method for the degradation of substances containing both aromatic rings
and ether bonds was reported in 1979 (Hotre, 1979; des Rosiers, 1983;
Esposito, 1980). This is of current interest because 2,3,7,8-TCDD contains
5-57
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decomposition of 2,3,7,8-TCDD without irradiation. This latter method
utilizing chloroiodides is therefore more suitable for degrading bulk
solutions.
*
5.7.2 Technology Performance Evaluation
No commercial processes utilizing chloroiodides for decomposition of
2,3,7,8-TCDD are known to exist. However, experiments illustrating the use of
surfactants containing chloriodides for the cleavage of ethers have been
accomplished. These experiments have been performed on substances such as
xanthene, benzofuran, and 2,3,7,8-TCDD (Botre, 1979). All substances tested
confirmed that chloroiodides aided in the decomposition. This discussion will
be limited to the results from experiments on 2,3,7,8-TCDD.
In one study, solutions containing 2,3,7,8-TCDD in benzene were vacuum
evaporated and the residues were treated with aqueous surfactant solutions
(Botre, 1979). Two chloroiodide derivatives were used in the surfactant
solutions: benzalkonium chloroiodide, and cetylpyridinium chloroiodide. When
benzalkonium was used, a 71 percent decomposition of 2,3,7,8-TCDD was
observed. When cetylpyridinium chloroiodide was used, a 92 percent
decomposition of 2,3,7,8-TCDD was achieved. Reaction products included
chlorophenols, phenols, and 2-phenoxychloro-phenols. Quantitative information
was not available for these substances. The results were obtained under ideal
conditions, so extrapolations to actual decontamination should be made with
great care.
Contaminated soil samples from Seveso, Italy were also treated
(Botre, 1979; des Roaiers, 1983; Esposito, 1980). Samples were prepared by
treating the soil with solutions containing surfactant micelles with
chloroiodides and micelles without chloroiodides. A benzalkonium chloride
micellar solution showed approximately a 14 percent decomposition of
2,3,7,8-TCDD. A solution containing benzalkonium chloroiodide in a micellar
solution showed a decomposition of 52 percent of 2,3,7,8-TCDD. Thus, the
addition of chloroiodides to micellar surfactant solutions greatly enhances
the decomposition of 2,3,7,8-TCDD. This study did not specify whether or not
exposure to UV radiation occurred. UV radiation may or may not enhance
decomposition significantly, depending on the experimental configuration.
5-59
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5.8 GAMMA RAY RADIOLYSIS
5.8.1 Process Description
s
Gamma rays are electromagnetic waves of energy (photons) similar to
x-raya, except that they are commonly generated in different ways and are of
much higher energy. In fact, gamma rays possess the highest energy levels of
all radiation in the electromagnetic spectrum. Gamma rays are emitted from
the nucleus of radioactive substances as a result of transitions of protons
and neutrons between two energy levels of the nucleus. X-rays, on the other
hand, are the result of the de-excitation of electrons to a lower energy
state. The energy of gamma rays ranges between 10 thousand electron volts
(KeV) and 10 million electron volts (MeV).
The mechanism of gamma ray interaction with matter is a complex function
of the radiation energy and the atomic number of the material (Kircher,
1964). At low energies, the gamma photon is completely absorbed by an
electron and the electron is ejected from the atom (photoelectric effect). At
higher energies, the photon can eject more strongly bound electrons, with the
photon being scattered at a reduced energy (Compton effect). The scattered
photon can also interact with electrons. At still higher energies, the gamma
ray can interact with a nucleus and be absorbed, resulting in the production
of two particles, a positive and a negative electron (pair production). The
minimum photon energy for pair production is 1.02 MeV.
In each of the mechanisms described above, energetic electrons are
produced, and it is this internal electron bombardment that actually causes
chemical changes in a material irradiated by gamma rays* Rupture of chemical
bonds results from the electron bombardment; thus organic hydrocarbons can be
effectively degraded by gamma radiation.
Commercial sources of gamma radiation generally are unstable isotopes of
cesium and cobalt. Gamma rays from cesium and cobalt-60 sources have energies
in the range of 0.40 to 1.33 MeV. In this range, the primary mechanism of
gamma ray interaction with matter is the Compton effect.
5-61
-------
Ethanol
10 20
Total absorbed dose (million rads)
30
Figure 5.8.1. Effect of Gamma Ray irradiation on 2,3,7,8-TCDD
concentration in ethanol, acetone and dioxane
[Fanelli, 1978J.
5-63
-------
Further research is needed to verify the possible application of g<
ray radiolysis in the destruction of dioxin molecules in soils. Based on
experimental data, it appears that a minimum dosage of 30 million rad of
radiation is required to reduce the 2,3,7,8-TCDD level from 100 ppb to 30 ppb.
(Fanelli, 1978).
5-63
-------
Bumpus, J.A., Tien, M., Wright, D.A. and Aust, S.D. Oxidation of
Persistent Environmental Pollutants by a White Rot Fungus. Science.
2^8:1434-1436. 1985.
Buser, Hans-Rudolph. Preparation of Qualitative Standard Mixtures of
Polychlorinated Dibenzo-p-dioxinsJ and Dibenzofurans by Ultraviolet and
-Irradiation of the Octachloro Compounds. Journals of Chromatography.
129:303-307. 1976.
Centofanti, L. PPM, Inc. Personal Communication. 1986.
Camoni, I., et al. Laboratory Investigation for the Microbial Degradation of
2,3, 7,8-tetrachlorodibenzo-p-dioxin in Soil by Addition of Organic
Compost. In; Chlorinated Dioxins and Related Compounds: Impact on the
. Environment. 0. Hutzinger, et al., editors. Pergammon Press, New York,
New York. pp. 95-103. 1982.
Chakrabarty, A. M. University of Illinois Medical Center at Chicago.
Personal communication with M. Sutton, GCA Technology Division, Inc..
17 January 1984.
Chatterjee, D. K., A. M. Chakrabarty. Generic Rearrangements in Plasmids
Specifying Total Degradation of Chlorinated Benzoic Acids. Mol. Gen.
Genet, 188:279-285. 1982.
Chatterjee, D. K., A. M. Chakrabarty. Genetic Homology Between Independently
Isolated Chlorobenzoate-Degraditive Plasmids. Journal of Bacteriology,
153(1):532. January 1983.
Chemical Engineering. Commercial Scale Ultraviolet Destruction of Dioxin.
88(18):18. September 7, 1981.
Commoner, B., and R. E. Scott. Center for the Biology of Natural Systems,
Washington University, St. Louis, Missouri. USAP Studies on the
Stability and Ecological Effects of TCDD (Dioxin): An Evaluation
Relative to the Accidental Dissemination of 2,3,7,8-TCDD at Seveso,
Italy. 1976.
Corwell, D., Yamasaki, R. S. Journal of Chemical Physics, 2(5):1064-1065.
November 1957.
Cotter, J. L., et al. TRW, Inc., Redondo Beach, CA. Facilities Evaluation of
High Efficiency Boiler Destruction PCB Waste - Research Brief. January
to April 1980. EPA Reprot No. EPA-600/7-81-031. NTIS. 1981.
Craft, T. P., R. D. Kimbrough, and C. T. Brown. Georgia Institute of
Technology. Radiation Treatment of High Strength Chlorinated Hydrocarbon
Wastes. U.S. EPA Report.EPA-660/2-75-017. July 1975.
Craft, T.F. Georgia Institute of Technology. Telephone communication.
May 1984.
5-67
-------
Fanelli, R., C. Chiabrando, M. Salmona, S. Garattini, and P. G. Calders.
Degradation of 2,3,7,8-Tetrachlorodibenzo-p-dioxin in Organic Solvents by
Gamma Ray Irradiation. Experentia. 34(9):1126-7. September 9, 1978.
Firestone, F. Oil and Hazardous Materials Spills Branch. Telephone
conversation with T. Murphy, GCA/Technology Division. 19 January 1984.
Fisher, Marilee. SunOhio, Inc. Personal Communication. 1986.
Flax, L. Lopat Enterprises, Inc. Telephone Conversation with Lisa Farrell,
GCA Technology Division, Inc. May 19, 1986.
Furukawa, K., A. M. Chakrabarty. Involvement of Plasmids in Total Degradation
of Chlorinated Biphenyls. Applied and Environmental Microbiology,
44(3):619. September 1982.
Ghosal, D., et al. Microbial Degradation of Halogenated Compounds. Science,
220: 135-228.
Gibson. Personal communication with M. Sutton, GCA Technology Division, Inc.
17 January 1984.
Oilman, W. S. United States Testing Company, Inc., Chemical Services Division.
Report of Test, January 4, 1983, February 7, 1983, February 17, 1983, May
31, 1983, June 13, 1983, August 4, 1983, August 19, 1983, August 23,
1983, October 13, 1983, October 21, 1983, December 22, 19*3.
Goldensohn, R. Red Tape Slows Jersey Inventors' PCB eater. Sunday Star-
Ledger, Neward, NJ, 70(223):68. 9 October 1983.
Goldsmith, D. Environmental Engineer, Sybirn Corporation. Personal
Communication with M. Arienti, GCA Technology Division. April 29,1986.
Hay, A. Disposing of Dioxins by Oxidation. Nature, 290:294. March 26, 1981.
Hazardous Waste Consultant. Stabilizing Organic Wastes: How Predictable
Are The Results? Volume 3, Issue 3, Pages 1-18 to 1-19. May/June 1985.
Helsel, R., et al. Technology Demonstration of a Thermal Desorption/UV
Photolysis Process for Decontaminating Soils Containing Herbicide
Orange. Preprint extended abstract. Presented before the Division of
Environmental Chemistry. American Chemical Society. New York.
April 1986.
Hutter, R., and M. Philippi. Studies on Microbial Metabolism of TCDD
Under Laboratory Conditions. In; Chlorinated Dioxins and Related
Compounds: Impact on the Environment. 0. Hutzinger, et al., editors.
Pergammon Press, New York, New York. pp. 87-93. 1983.
IT Corporation. Interim Summary Report on Evaluation of Soils Washing and
Incineration as On-Site Treatment Systems for Dioxin-Contaminated
Materials. EPA Contract No. 68-03-3069. 1985.
5-69
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Legan, R.W. Ultraviolet Light Takes on CPI Role. Chemical Engineering,
9(2):95-100. January 25, 1982.
Lubovitz, H. R., et al. Contaminant Fixation: Practice and Theory. Land
Disposal of Hazardous Waste. Proceedings of the Tenth Annual Research
Symposium. EPA-600/9-84-007. April 1984.
Nalone, P. U.S. Army Engineer Waterways Experiment Station, Vicksburg,
Mississippi. Telephone conversation with R. Bell, GCA/Technology
Division. 27 March 1984.
McDaniel, P. Inventors Say They Can Neutralize Dioxin. Asbury Park Press,
Asbury Park, NJ. p. A4. 12 June 1983.
Miille, G. J. Acurex Corporation. Paper presented to the PCB Seminar,
sponsored by the Electric Power Research Institute. December 19bl.
M. M. Dillon, Ltd. Destruction Technologies for Polychlorinated Biphenyls
(PCBs). Prepared for Environment Canada, Waste Management Branch. 1982.
Peterson, R. L., et al. Chemical Destruction/Detoxification of Chlorinated
Dioxins in Soils. Paper presented at Eleventh Annual Research Symposium
on Incineration and Treatment of Hazardous Waste. EPA-600/9-85-028.
September 1985.
Peterson, R. L., et al. Comparison of Laboratory and Field Test Data in the
Chemical Decontamination of Dioxin Contaminated Soils Using the Galson
PKS Process. Preprinted Extended Abstract. Presented before the
Division of Environmental Chemistry. American Chemical Society.
New York. April 1986.
Peterson, R.L. Galson Research Corporation, E. Syracuse, NY Telephone
Conversation with M. Jasinski, GCA Technology Division, Inc. June 19£ba.
Philippi, Martin, et al. Fate of 2,3,7,8-TCDD in Microbial Cultures and in
Soil Under Laboratory Conditions. Fens Symp., Vol. 12, Iss. Microbial
Degradation Xenobiotics Recalcitrant Compd. pp. 221-3. 1981.
Philippi, M., et al. A Microbial Metabolite of TCDD. Experientia,
38:654-661. 1982.
Pierce, F. Sandia National Lab. Telephone Communication. May 1984.
Pocchiari, F. 2,3,7,8-Tetrachlorodibenzo-p-dioxin Decontamination. In:
Chlorinated Phenoxy Acids and Their Dioxins. Ramel, editor. Ecol.
Bulletin (Stockholm), 27:67-70. 1978.
Poiger, H., et al. Special Aspects of Metabolism and Kinetics of 2,3,7,8-TCDD
in Dogs and Rats - Assessment of Toxicity of 2,3,7,8-TCDD Metabolites In
Guinea Pigs. In: Chlorinated Dioxins and Related Compounds: Impact on
the Environment. 0. Hutzinger, et al., editors. Pergammon Press, New
York, New York. pp. 317-324. 1983.
5-71
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Tellea, R. W., et al., Review of Fixation Processes to Manage Hazardous Organic
Waste. Draft Report. Carlton Wiles, Project Officer, MERL, Cincinnati,
Ohio. April 1984.
Tieran, T. 0., et al. Dioxins. Industrial Environmental Research Laboratory,
Office of Research and Development, Cincinnati, Ohio. EPA-600/2-80-197.
November 1980.
Tieran, T. 0. Chlorodibenzodioxins and Chlorodibenzofurans: An Overview,
Detoxification of Hazardous Waste. Ann Arbor Science, Ann Arbor,
Michigan, p. 245. 1982.
Tittlebaum, Marty E., et al. State-of-the-Art on Stabilization of
Hazardous Organic Liquid Wastes and Sludges. In: Critical Reviews in
Environmental Control, 15(2)-.179-211. 1985.
Tridje, J. Michigan State University. Personal communication with M. Sutton,
GCA/Technology Division. 18 January 1984.
Tundo, P. Chemical Degradation of 2,3,7,8,-TCDD By Means of Polyethylene-
glycols in the Presence of Weak Bases and an Oxidant. In; Chemosphere.
Volume 14, No. 5, pp. 403-410. 1985.
Tumiatti, W. Site Decontamination and Chemical Degradation of PCDFs and
PCDDs Coming From Pyrolysis of PCBs. Preprinted Extended Abstract.
Presented Before the Division of Environmental Chemistry. American
Chemical Society. New York. April 1986.
U.S. Army Engineers, Waterways Experiment Station, Environmental Laboratory,
Vicksburg, Mississippi. Guide to the Disposal of Chemically Stabilized
and Solidified Waste. Report prepared for U.S. EPA, Solid and Hazardous
Waste Research Division, Municipal Environmental Research Laboratory,
Cincinnati, Ohio. EPA-IAG-D4-0569. September 1982.
Valentine, R.S. LARC-Light Activated Reduction of Chemicals. Pollution
Engineering. 1981.
Vanness, G. P., et al. Tetrachlorodibenzo-p-Dioxins in Chemical Wastes,
Aqueous Effluents and Soils. Chemosphere. 9(9):553-63. 1980.
Vick, W.H., S. Denzer, W. Ellis, J. Lambauch, and N. Rottunda. Evaluation of
Physical Stabilization Techniques for Mitigation of Environmental
Pollution from Dioxin-Contaminated Soils. Interim Report: Summary of
Progress-To-Date. Submitted to EPA-HWERL by SAIC/JRB Associates, EPA
Contract No. 68-03-3113, Work Assignment No. 36. June 1985.
Ward, C. T., et al. Fate of 2,3,7,8-Tetrachlorodibenzo-p-Dioxin (2,3,7,8-TCDD)
in a Model Aquatic Environment. Archives of Environmental Contamination
and Toxicology. 7:349-357. 1978.
5-73
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SECTION 6
FACTORS AFFECTING TECHNOLOGY SELECTION
Section 3 contained information on the quantities and types of dioxin
wastes generated by industrial processes and residuals identified as sources
of dioxin-containing waste. Table 6.1 summarizes information on their
sources, their usual physical form, and estimates of present and future
quantities of wastes generated within each EPA waste code. Sections 4 and 5
contained information on the technical aspects of a number of potential
treatment technologies for these wastes. This information is summarized in
Table 6.2.
The purpose of this section is to review this previously developed
information and identify factors which would affect the selection/use of a
particular technology for treating a specific waste type. This document has
been concerned largely with the assessment of the technical factors relating
to treatment technology performance. However, both technical performance and
cost will generally be considered when selecting the most appropriate process
for a -specific waste stream. Both are considered in the following discussions.
6.1 TECHNICAL REQUIREMENTS FOR PROCESS SELECTION
Key factors which should be considered in assessing the technical
applicability of treatment technologies to specific waste streams include:
I. Has the technology demonstrated that it can achieve 99.9999 percent
ORE on CDD (or similar compounds)?
6-1
-------
(pami|)U03)
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•noaicf qdd ({) q9«*f l»«|l ]• I|o« !i*i»*ii u|xo|p «plnbl|
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lou »J« «paa] plioi tauiu aajqi pai«Ji«noBap Xiao Xiao t«|3d JOI P*l "•• 000*01
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JIB »oj| »j«]n3iu«d ,( nixoip no paivjuuoaap gijo jo] niun aiq«ii>AW
>]ait9>i»n jaqqnjii '(q«») 'Pilot oj 10} tau^u »AI, aaqi aai«aj> '193^ X|iai}ja*MO3 pui
_ ^ _ jj.0| J0} ng „„,„ ,,, UW|(J j,,MJO p»AOjdd» |>J>A>S tatpnii 'ipinbi) *ipi|os Xjcioi XJiuoiitij
1103
10JJ»d }O a>us
sassaooHd iNawivaai jo AHVHHHS 'z'9 aiavx
-------
TABLE 6.2 (continued)
Proceaa name
UV Photolysis
•Chemical
Dechlorination-
APEC procaaaea
• inimical
Applicable
waste streams
Liquids, atill bottoms,
and aoila can be treated
if dioxin ia firat
extracted or deiorbed
into liquid
Contaminated aoil (other
variation! of the proceaa
uaed to traat PCS-conta-
minated oila)
Research haa bean directed
Stage of
development
Pull scele aolvent
extraction/UV
proceaa waa uaed to
treat 4,300 gallona
of atill bottom! in
1980; thermal de-
aorpt ion/UV procaaa
currently undergoing
aecond timid teit
Slurry proceea
currently being
field teated at
pilot acala; in aitu
procaaa haa bean
teatad in the field
Performance/
destruction achieved
Greater than 98. 7S raduction of
TCDD uaing aolvent extraction/
UV proceaa - raaiduala con-
tained ppm concantrationa of
TCDD; thermal daaorption/UV
proceaa demonstrated reduction
of TCDO in aoil to below 1 ppb
Laboratory reaearch hae
demonstrated reduction of
2,000 ppb TCDD to below 1 ppb
for slurry (batch proceaa);
laboratory and field teating
of in aitu proceaa not aa
promising
SO-60X metabolism of 2.3.7.8-
Coat
Coat of treeting
the 4,300 gallona
of atill bottom!
using solvent
extraction/UV waa
SI million; ther-
mal deaorpt ion/UV
eatimated to coat
t296/ton for in
aitu APRC proceaa;
|9l/ton for
alurry (batch)
proceaa
MA
Reaiduala
gsnereted
Solvent extrect ion/UV
process genereted treated
atill bottoms, a solvent
extract atream, and an
aqueous sslt streem;
thermel desorption/UV
•trea* and a solvent
Treated soil containing
chloride aalta (reagent
ia recovered in the
•Lurry proceaa)
*
Degradation- toward in aitu treatment acala-field teating TCDD in a week long period
primarily in aitu of contaminated aoila - in next year or two under leb conditiona uaing white
addition of microbe! liquid! era alao poaiibla rot fungua - reduction to
below 1 ppb not achieved
Chemical
Degradation uaing
lutbenium Tatroxida
Chemical
Degradation uaing
Chloroiodidea
Liquid or aoil waataa -
poaalble moat affactlva
in decontaminating
furniture, othar aurtacaa
Liquid or aoil - thought
to be mo»t applicable to
decontaminating furniture
and buildinga
Laboratory acale -
no work reported
alnca 1*6)
Laboratory acala -
no work reported
aince 198)
Reduction of 70 ppb TCDD to
below 10 ppb in 1 hr (on aoil
•ample)
Up to 92X degradation on
aolution of TCDD in banxene -
reduction! to below 1 ppb were
not demon!treted
HA
HA
as aoil or water with TCDD
metabolites depending on
microorganism!
Treeted medium plui the
aolvent which has been
edded (weter, CCI4); TCDD
and products not known
Treated waste medium;
degredetion end producta
are chlorophenola
Ray Radiolyaii Liquid waste atreama (haa Laboratory raaearch; 97X deatruction of 2,3,7,8-TCDD Coat for aewage
been applied to sewage no reaeerch in ethanol after 30 houra - die infect ion
aludge diainfection)
currently being
conducted
100 ppb to ) ppb
Leai chlorinated dioxin
molecules sre the degrede-
fscility treating tion end product! in add-
4 tone per day ii it ion to the treated waata
|40 per ton; TCDD medium
treetment would be
more expenaive
-------
TABLE 6.3. TREATMENT TECHNOLOGY SELECTION CHART
Ho* dmon-
niaae Ml on Procaaa can Can treat
dioiU and/or be carried aolida Can treat
reduction of Ha a danao- Mobil* or out in aitu auch •• liquid* Currant IT being I* • pre-
dioxlo in atratad aix traoaportabl* (without aoila and and lev io**ati«*tad treacnant or
residual* to nine* Ml proceaa can be excavation heavy «i*co*ity "ith regard to temporary I* • final
»««*••• ••»•» 1 H* of KM conatructed of .oil) .ludge* sludge* dioxin «..t* proceaa proce.a
Stationary rotary kiln X X° X X
Mobil* rotary kiln I* I I X" I I
Liquid injection incinerator I X
fluidiaod bed f circulating bed IX X» I
X
X
X
J,
•igb tao»>eratura fluid wall I* X I X" X X x
(Huber AM)
Infrared incinerator (Shirco) I I x X X
rlaama arc II IX * ' I
Molten aalt , I I* x( X x
Supercrlticel voter' I« , X X* Xn X X
!• *itu "vitrification IX X
Solvent a*tractloo XB X X X
Stebilisatlon/iixatio* IX IX
UV pbotoly*!* ic X4 X X X
ChaeUcel decblorination (APIC) X« x x1 X» I X X
X X» I X X
iun> tatroxida Xh X X
Cnloroiodidee X Xh X
rof
X
•tP4 BObila rotary kiln. fThere exiat* botb an in situ end a batch reactor procaaa.
•Tbair atationary unit ia permitted to do raeaarch on dloxio waatea. (High eah vaate* nay poae problaaia.
cDe»eloper ha* indicated thia, but pr***nt*d no data. hlndicatae primary vaet* type.
dU»ing laboratory ecele equipment. 'solid* only treated if aon« aorc of axtractioo/daaorptlon
•One developer ie deaigning a noblie unit. procaaa r*w>vea the dioxin fron aoil.
-------
6.1.3 Mobile/Transportable Technology
The ability to bring the waste treatment unit to the waste site is very
important, particularly when treating "dioxin" waste. The transportation of
dioxin waste is very controversial, and has been opposed
by the public in several instances. For example, an attempt was made to
obtain permission to transport dioxin-containing leachate to the SCA
incinerator in Chicago. Illinois residents strongly objected to this, and
local authorities indicated that drastic measures would be used to block the
effort (Gianti, 1986). As a result, many of the developing thermal and
nonthermal technologies are being designed to function as mobile/transportable
units that can be taken to the waste site. The units that are mobile are
identified in Table 6.3. Stationary treatment facilities, even though they
are able to demonstrate high levels of destruction, may not be fully utilized
for highly toxic dioxin wastes.
In addition to avoiding the risk of spillage during transportation,
another advantage of the use of a mobile unit is that the cost of transporting
the waste to the treatment facility is eliminated. For each of these reasons,
processes that are designed to be mobile appear to be more useful for treating
listed dioxin wastes.
6.1.4 In Situ Technology
Similarly, processes than can treat the waste in situ may also be
advantageous. In situ processes are aimed primarily at contaminated soil.
Most processes require that the soil be excavated and then be fed to the
treatment process. A process in whicfc" the excavation step is eliminated may
be more environmentally and economically acceptable than a process that relies
on excavation of the waste* Not only is excavation expensive, but it may also
result in the dispersal of contaminated soil particles and greater human
exposure to the contaminant. Processes with the potential for in situ use
include chemical dechlorination, in situ vitrification, biodegradation, and
stabilization/fixation. Chemical dechlorination, using potassium polyethylene
glycol (KPEG), has been tested both as an in situ and a batch reactor type of
process. As indicated in Section 5, the batch reactor variation of the
6-9
-------
gamma ray radiolysis. Other technologies, including both fluidized bed and
rotary kiln incineration, chemical dechlorination, and the high temperature
fluid wall process have been used to treat both liquid and solid wastes.
Finally, other processes are designed to be used primarily for either liquids
i
or solids, but if certain pretreatment measures are applied, they may be able
to treat both waste forms. For example, ultraviolet (UV) photolysis is only
effective in treating waste streams that the radiation can penetrate, such as
a nonabsorbing liquid. If, however, the contaminant is first desorbed, either
thermally or using an organic solvent, a contaminated soil waste can be
treated using this technology.
Perhaps the most important factor with regard to the physical properties
of a waste stream is that each waste stream must be treated individually, and
variations in waste characteristics fully assessed, to ensure that
unanticipated difficulties do not arise. Even though pilot or laboratory
scale data may indicate that a certain waste form is easily treatable,
processing of the actual waste stream may pose problems. One example of this
is the trial burns of Vertac still bottoms at the Combustion Research
facility. The waste stream, on the basis of preliminary evaluations, was
originally pumped through a feed lance into the rotary kiln without dilution
or mixing with fuel. However, the lance frequently became inoperative due to
clogging and carbon buildup, and the waste feed had to be interrupted so the
lance could be cleaned. The problem was finally rectified by diluting the
waste with water prior to pumping it into the kiln (Ross et al., 1986).
Another example is the application of KPEGs directly to soil (in situ) to
dechlorinate TCDO. In the lab, the process was fairly successful, but when
*
applied in the field the KPEG reagent was seriously degraded by moisture in
the soil, and the resulting degradation of TCDD was minimal. A third example
involves the Huber AER. This unit was originally tested on very granular,
uniform materials such as sand. In reality, all contaminated solids or soils
are not as dry and uniformly graded as sand. Consequently, when the Huber
reactor was tested on actual waste, there were problems with the feed
mechanism. Special pretreatment measures to produce a granular, free-flowing
feed had to be incorporated (Boyd et al., 1986).
To summarize, waste characteristic* and process capabilities must be
carefully evaluated before the appropriate treatment technology can be applied.
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The cost of treating dioxin-containing waste is very much affected by the
high level of risk associated with the treatment of these waste streams and
their residuals. Generally, processing of these wastes requires the
imposition of extraordinary and often redundant measures to ensure that risks
are not incurred by workers and the general population. One example of this
was the attempted incineration several years ago of 6,000 gallons of solvent
waste contaminated with 14 ppb of TCDD. The Dioxin Disposal Advisory Group
(DDAG) recommended incineration of the waste at the ENSCO incinerator in
Arkansas. ENSCO usually charges $325 per 55-gallon drum of hazardous waste,
but in this case they would have charged $45,000 for the waste plus a $150,000
surcharge because it contained dioxin (Technical Resources, Inc. 1985)* This
amounts to a unit cost of approximately $30/gallon ( $1,500 per 55-gallon
drum) or $6,000/ton for 10 Ib/gallon waste. In the end, however, ENSCO
refused to accept the waste because of overwhelming public opposition (and
implied liability).
Cost will always be an important factor in the selection pf a treatment
method, but at this time the demonstration of technical and environmental
effectiveness appears to a more overriding concern. Technology oust be fully
demonstrated for treating dioxin wastes if public concerns are to be addressed
and reconciled with the need for effective treatment.
6.3 SUMMARY
Each of the technical and cost factors discussed above will affect the
final selection of a technology to treat the waste. It is important to keep
in mind that the field of dioxin waste treatment is in a developmental stage.
At the present time, only a few of the technologies have demonstrated 6 nines
ORE on CDDs and CDFs, although many of the technologies are now undergoing
performance testing using dioxin waste, or will undergo testing in the near
future. In addition, with the ban on land disposal of dioxin wastes scheduled
to go into effect in November 1986, work on the development of additional new
technologies for treating these wastes can be expected-to accelerate.
Information in this document represents .the developmental status of dioxin
waste treatment technologies in the spring of 1986; revisions will be required
as anticipated technical advances are made in the future.
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