EPA/540/2-89/009
SUPERFUND TREATABILITY
CLEARINGHOUSE
Document Reference:
Environmental Science and Engineering, Inc. "Final Report: Development of Optimum
Treatment System for Wastewater Lagoons Phase II - Solvent Extraction Laboratory
Testing." Prepared for USATHMA, 85 pp. October 1984.
EPA LIBRARY NUMBER:
Superfund Treatabillty Clearinghouse -EURU
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SUPERFUND TREATABILITT CLEARINGHOUSE ABSTRACT
Treatment Process:
Media:
Document Reference:
Document Type:
Contact:
Physical/Chemical - Chemical Extraction
Soil/Lagoon Sediment
Environmental Science and Engineering, Inc. "Final
Report: Development of Optimum Treatment System
for Wastewater Lagoons Phase II - Solvent
Extraction Laboratory Testing." Prepared for
USATHMA, 85 pp. October 1984.
Contractor/Vendor Treatability Study
Wayne Sisk
U.S. DOD/USATHAMA
Aberdeen Proving Ground, MD
301-671-2054
21010-54401
Site Name:
Location of Test:
Ft. Wingate, NM; Navajo, AZ; and Shreveport, LA
(NPL - Federal facility)
Gainsville, FL
BACKGROUND; The U.S. Army surveyed innovative treatment techniques for
restoration of hazardous waste lagoons and selected solvent extraction as
cost-effective restoration for further study. This treatability study
focuses on treatment of organic (explosive) contaminated lagoon sediments
which are the result of munitions production operations. Primary contami-
nants of concern included the following explosives: TNT, DNT, RDX and
Tetryl. This was a laboratory study of solid extraction where the solvent
is used in excess and the effectiveness of a single contact is limited by
the ability to physically separate the liquid and soil fractions. The
treatability goal is to reduce explosive contaminant level to 10 mg/kg.
OPERATIONAL INFORMATION; Sediments tested were obtained from Navajo Army
Depot (AD), AZ (predominantly volcanic cinders); Ft. Wingate AD, NM (mostly
clay); and Louisiana Army Ammunition Plant. Explosive content of sediments
ranged from 0.1-99/K and moisture content ranged from 23.8-42.8£. (Report
provides characteristics information on sediments.) Acetone was selected
as the leaching agent based on the solubility of contaminants, cost, and
availability. Laboratory tests included: solubility, leaching efficien-
cies, and settling tests. Solubility tests evaluated water/acetone ratios
to determine optimum operational range for individual contaminants and
mixtures. Leaching tests evaluated effectiveness of countercurrent
extraction to determine contact time required for equilibrium of explosives
between leachate and the sediments. Multiple leaching tests were performed
by shaking sediment with acetone/water mixture in 1-liter graduated
cylinders for 30 minutes followed by solid-liquid separation. Settling
tests were performed on two soils with significant solid content to
determine settling rate to aid in design of waste water treatment unit.
3/89-45 Document Number: EURU
NOTE: Quality assurance of data may not be appropriate for all uses.
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Report provides a discussion of sampling and analysis methods and provides
limited QA/QC information.
PERFORMANCE; Laboratory leachability studies indicated that wet,
explosive-laddened sediments can be effectively decontaminated by leaching
with an acetone/water mixture. In general, three to four contact stages of
30 minutes each were required to reduce the explosives level to less than
10 rag/kg. A fifth contact stage with a 50% efficiency would have been
required to achieve the goal for the Louisiana sediment. Solubility tests
demonstrated a non-linear solubility of explosives with acetone/water.
Saturated solutions between 50 and 90% acetone form a two-phase liquid
solution which should be avoided since this could hinder penetration of
solvent through sediment. A conceptual treatment system design is provided
based on results of tests. Calculated 4 stage removal efficiencies are
shown in Table 1.
CONTAMINANTS:
Analytical data is provided in the treatability study report. The
breakdown of the contaminants by treatability group is:
Treatability Group
W06-Nitrated Aromatic
Compounds
CAS Number
118-96-7
99-35-4
121-82-4
Contaminants
Trinitrotoluene (TNT)
Trinitrobenzene (TNB)
Hexahydro-l,3,5-trinitro-
1,3,5-triazine (RDX)
TABLE 1
INITIAL SEDIMENT EXPLOSIVES CONCENTRATION, FINAL SEDIMENT
EXPLOSIVES CONCENTRATION, AND CALCULATED 4-STAGE
REMOVAL EFFICIENCIES
Sediment
Initial
Explosives
Concentrations
(mg/kg)
Final
Explosives
Concentrations
(mg/kg)
4-Stage
Removal
Efficiency
Ft. Wingate AD
Navajo AD
Louisiana
1,200
19,000
420,000
6.0
7.0
17.0
99.5
99.96
99.996
NOTE: This is a partial listing of data.
information.
Refer to the document for more
3/89-45 Document Number: EURU
NOTE: Quality assurance of data may not be appropriate for all uses.
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REPORT AMXTH-TE-CR-84302
FINAL REPORT
DEVELOPMENT OF OPTIMUM TREATMENT SYSTEM
FOR WASTEWATER LAGOONS
PHASE II
SOLVENT EXTRACTION LABORATORY TESTING
CONTRACT DAAK11-81-C-0076
TASK ORDER 6
Prepared by:
ENVIRONMENTAL SCIENCE AND ENGINEERING, INC.
P.O. BOX ESE
GAINESVILLE, FLORIDA 32602-3053
October 1984
Distribution limited to U.S. Government agencies:
Research and Development (October 1984).
Other requests for this document must be referred to:
Commander, U.S. Army Toxic and Hazardous Materials Agency,
ATTN: AMXTH-ES, Aberdeen Proving Ground, Maryland 21010
Prepared for:
U.S. ARMY TOXIC AND HAZARDOUS MATERIALS AGENCY
ABERDEEN PROVING GROUND, MARYLAND
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10/12/84
TABLE OF CONTENTS
Section Page
1.0 INTRODUCTION 1-1
1.1 BACKGROUND 1-1
1.2 REGULATORY CONSIDERATIONS 1-4
1.3 OBJECTIVES 1-5
2.0 BASIC PRINCIPLES 2-1
2.1 PHASE EQUILIBRIUM 2-1
2.2 SETTLING TESTS 2-3
2.3 LEACHING STAGE EFFICIENCY 2-4
3.0 EXPERIMENTAL PROCEDURES 3-1
3.1 EXPERIMENTAL MATERIALS 3-1
3.1.1 Explosives 3-1
3.1.2 Solvents 3-2
3.1.3 Sediments 3-2
3.2 EXPERIMENTAL METHODS 3-2
3.2.1 Characterization of Sediments 3-2
3.2.2 Solubility Experiments 3-4
3.2.3 Leach Rate Experiments 3-5
3.2.4 Countercurrent Extraction 3-8
3.2.5 Settling Tests 3-11
4.0 EXPERIMENTAL RESULTS 4-1
4.1 INDIVIDUAL EXPLOSIVE SOLUBILITIES 4-1
4.1.1 TNT Solubility 4-1
4.1.2 DNT Solubility 4-4
4.1.3 Tetryl Solubility 4-6
4.1.4 RDX Solubility 4-6
4.2 MULTICOMPONENT SOLUBILITY 4-7
4.3 LEACH RATE TESTS 4-11
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10/10/84
TABLE OF CONTENTS
(Continued, Page 2 of 2)
Section
5.0
6.0
4.4 COUNTERCURRENT EXTRACTION
4.4.1 Ft. Wingate AD Sediment
4.4.2 Navajo AD Sediment
4.4.3 Louisiana AAP Sediment
SUMMARY AND CONCLUSIONS
CONCEPTUAL TREATMENT SYSTEM DESIGN
Page
4-11
4-11
4-13
4-14
5-1
6-1
REFERENCES
APPENDIX A~ANALYTICAL METHODS
ii
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D-THAMA-TASK6.I/SEDR-LOT.1
10/12/84
LIST OF TABLES
Table Page
3-1 Characterization Data for Sediments Used in
Solvent Extraction and Aqueous Thermal Decompo-
sition Testing 3-3
3-2 Individual Explosives Solubility Test Scheme 3-6
3-3 Mixed Explosives Solubility Test Scheme 3-7
3-4 Leach Rate Test Scheme 3-8
3-5 Countercurrent Extraction Feed Scheme 3-10
4-1 TNT Solubility in Acetone/Water 4-2
4-2 DNT Solubility in Acetone/Water 4-5
4-3 Tetryl Solubility in Acetone/Water 4-6
4-4 RDX Solubility in Acetone/Water 4-6
4-5 Solubility of Explosives in Multicomponent System 4-8
5-1 Initial Sediment Explosives Concentration, Final
Sediment Explosives Concentration, and Calculated
4-Stage Removal Efficiencies 5-1
6-1 Cornhusker AAP Solvent Extraction Material Balance 6-5
6-2 Louisiana AAP Solvent Extraction Material Balance 6-6
6-3 Savanna AD Activity Solvent Extraction Material
Balance 6-7
ill
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D-THAMA-TASK6.I/SEDR-LOF.1
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LIST OF FIGURES
Figure Page
2-1 TNT/Acetone/Water Phase Diagram, Weight-Fraction
Basis 2-6
3-1 Four-Stage Countercurrent Leaching Simulation 3-12
4-1 Titration Experiments ' 4-17
4-2 Solubility of TNT in Acteone/Water 4-18
4-3 DNT/Acetone/Water Phase Diagram, Weight-Fraction
Basis 4-19
4-4 Solubility of DNT in Acetone/Water 4-20
4-5 Solubility of Tetryl in Acetone/Water 4-21
4-6 Solubility of RDX in Acetone/Water 4-22
4-7 Solubility of TNT*in Multicomponent System 4-23
4-8 Solubility of DNT in Multicomponent of System 4-24
4-9 Solubility of RDX in Multicomponent System 4-25
4-10 Solubility of Tetryl in Multicomponent System 4-26
4-11 Comparison of TNT Solubility in Ternary and
Multicomponent Systems 4-27
4-12 Comparison of DNT Solubility in Ternary and
Multicomponent Systems 4-28
4-13 Comparison of RDX Solubility in Ternary and
Multicomponent Systems 4-29
4-14 Comparison of Tetryl Solubility in Ternary and
Multicomponent Systems 4-30
4-15 Sediment Leach Rate—Ft. Wingate AD and Navajo AD 4-31
4-16 Sediment Leach Rate—Louisiana AAP 4-32
4-17 Countercurrent Extraction Simulation—Ft. Wingate AD 4-33
4-18 Normalized Liquid TNT Concentration in Countercurrent
Leaching—Ft. Wingate AD 4-34
iv
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D-THAMA-TASK6.1/SEDR-LOF.2
10/12/84
LIST OF FIGURES
(Continued, Page 2 of 2)
Figure Page
4-19 Ft. Wingate AD Entrainment Effects 4-35
4-20 Normalized Sediment TNT Concentration in Countercurrent
Leaching—Ft. Wingate AD 4-36
4-21 Ft. Wingate AD Settling Test 4-37
4-22 Countercurrent Extraction Simulation—Navajo AD 4-38
4-23 Normalized Liquid TNT Concentration in Countercurrent
Leaching—Navajo AD 4-39
4-24 Navajo AD Entrainment Effects 4-40
4-25 Normalized Sediment TNT Concentration in Countercurrent
Leaching—Navajo AD 4-41
4-26 Navajo AD Settling~Test 4-42
4-27 Countercurrent Extraction Simulation—Louisiana AAP 4-43
4-28 Normalized Liquid Explosives Concentration in
Countercurrent Leaching—Louisiana AAP 4-44
4-29 Louisiana AAP Entrainment Effects 4-45
4-30 Normalized Sediment TNT Concentration in Countercurrent
Leaching—Louisiana AAP 4-46
5-1 Stagewise TNT Removals Versus Entering TNT Concentrations 5-4
6-1 Solvent Extraction System Process Flow Diagram 6-2
6-2 Solvent Extraction System Block Diagram 6-4
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D-THAMA-TASK6.1/SEDR-LOAA.1
07/16/84
LIST OF ACRONYMS AND ABBREVIATIONS
AAP army ammunition plant
AD army depot
AMCCOM U.S. Army Armament, Munitions, and Chemical Command
ASTM American Society for Testing and Materials
CFR Code of Federal Regulations
COR Contracting Officers Representative
DNT dinitrotoluene
EPA U.S. Environmental Protection Agency
ESE Environmental Science and Engineering, Inc.
Ft. fort
GC gas chromatography
gm gram(s)
gm/cc gram(s) per cubic centimeter
HMX cyclotetramethylenetetranitramine
HPLC high-pressure liquid chromatography
1 liter(s)
In logarithm
mg/kg milligram(s) per kilogram
mg/1 milligram(s) per liter
ml milliliter(s)
OECD Organization for Economic Cooperation and Development
RCRA Resource Conservation and Recovery Act
RDX cyclotrimethylenetrinitramine
SARMs Standard Analytical Reference Materials
TCD thermal conductivity detection
TNB trinitrobenzene
TNT trinitrotoluene
TSS total suspended solids
USATHAMA U.S. Army Toxic and Hazardous Materials Agency
UV ultraviolet
vi
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D-THAMA-TASK6.1/SEDR-1.1
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1.0 INTRODUCTION
1.1 BACKGROUND
Lagoons at U.S. Army installations throughout the United States have been
used for disposal of wastewater and sludge from a variety of industrial
operations, including:
1. Primary explosives manufacture,
2. Secondary explosives manufacture,
3. Explosives washout,
4. Load and pack,
5. Detonator load,
6. Metal plating, and
7. Propellant manufacture.
The U.S. Army, concerned that many of the lagoons may present a potential
for contamination of surface and ground waters, has established an
aggressive program of lagoon decontamination. The sheer magnitude of
the effort dictates the development of appropriate technologies that are
effective and safe, and more economical than conventional excavation and
disposal technologies.
A study of innovative treatment techniques for restoration of hazardous-
waste lagoons was conducted by Environmental Science and Engineering,
Inc. (ESE) for the U.S. Army Toxic and Hazardous Materials Agency
(USATHAMA), the results of which are detailed in a 4-volume report,
AMXTH-TE-83232, September 1983. The primary objective of the study was
to identify and evaluate cost-effective restoration methods,
implenientable by the late 1980s, which would be not only economical and
effective but also applicable to similar problems at a number of
locations and easily transportable. Broad applicability of treatment is
required because lagoons at different installations are of various sizes,
depths, and configurations and contain various amounts of water and
sediments with a diverse range of contaminants.
1-1
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Unclassified
SECURITY CLASSIFICATION OF THIS PAGE (Whan D*tm Ent»r»d)
REPORT DOCUMENTATION PAGE
READ INSTRUCTIONS
BEFORE COMPLETING FORM
1. REPORT NUMBER
AM. XTH-TE-CR-84302
2. GOVT ACCESSION NO,
3. RECIPIENT'S CATALOG NUMBER
4. TITLE (*nd Subtltl*)
Development of Optimum Treatment System
for Wastewater Lagoons (Phase II—Solvent
Extraction Laboratory Testing)
5. TYPE OF REPORT & PERIOD COVERED
Final Report
October 12, 1984
6. PERFORMING ORG. REPORT NUMBER
7. AUTHORf»J
Louis J. Bilello, P.E.; John D. Crane, P.E.;
Rex E. Hall; David H. Powell, Ph.D.;
Linda D. Tournade: and John w. Vinzant, P.E.
8. CONTRACT OR GRANT NUMBERfi.)
DAAK11-81-C-0076
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Environmental Science and Engineering, Inc.
P.O. Box ESE
Gainesville, FL 32602
10. PROGRAM ELEMENT. PROJECT, TASK
AREA ft WORK UNIT NUMBERS
Task 6
II. CONTROLLING OFFICE NAME AND ADDRESS
Commander, U.S. Army Toxic and Hazardous
Materials Agency
Aberdeen Proving Ground, Md. 21010
12. REPORT DATE
October 1984
13. NUMBER OF PAGES
100
14. MONITORING AGENCY NAME ft AOORESSff/ dltl»r*nt /ram Controlling Oltlem)
U.S. Army Toxic and Hazardous Materials Agency
Aberdeen Proving Ground, Md. 21010
IS. SECURITY CLASS, (at thl* nport)
Unclassified
I5«. DECLASSI Ft CATION/DOWN GRADING
SCHEDULE
16. DISTRIBUTION STATEMENT (at thl* Report)
Distribution limited to U.S. Government agencies: Research and Development
(October 1984). Other requests for this document must be referred to:
Commander, U.S. Army Toxic and Hazardous Materials Agency, ATTN: AMXTH-ES,
Aberdeen Proving Ground, Maryland 21010
17. DISTRIBUTION STATEMENT (of tn« mbtttuct tntftmd In Block 20, II dllloront /ram Rmport)
IS. SUPPLEMENTARY NOTES
19. KEY WORDS (Conitnuf on nnt»» *ld» II n«c»«««y «nd Identify oy block number;
Waste Decontamination RDX
Lagoon
Sediments
Solvent extraction
Leaching
Treatment
Explosives
TNT
DNT
Tetryl
Acetone extraction
Solubility
Hazardous
2O. ABSTRACT CCaatfau* a rmvorwf •** ft mcMMrr «* Idmtttr by block number)
A laboratory-scale study was conducted to test the technical feasibility
of applying acetone extraction to decontamination of wet explosives-ladened
lagoon sediments. The experimental approach was to determine pure explosive
compound solubilities in acetone/water mixtures, and finally to test the
effectiveness and efficiency of acetone leaching on actual lagoon sediments.
The materials used in the solubility experiments were pure 2,4,6-trinitro-
toluene (TNT), 2,4-dinitrotoluene (DNT), cyclotrimethylenetrinitramine (RDX),
and tetryl. Lagoon sediments were obtained from Ft. Wingate Army Depot (AD),
DO
U73
EDITION OF 1 NOV 65 IS OBSOLETE
Unclassified
SECURITY CLASSIFICATION OF TMrS PAGE (Wtnn Dmtm Ent»r»d)
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D-THAMA-TASK6.1/SEDR-1.2
07/16/84
To characterize the problem, existing lagoon data were compiled and
reviewed. In addition, to provide more complete data, samples from two
lagoons were collected and analyzed. Concurrently, potential waste
treatment techniques were investigated. Lagoons were initially divided
into classifications according to the industrial process which generated
the waste.
Although the lagoons studied were the product of six major process types,
from the point of view of treatment the lagoons could be effectively
classified into two types based on major contaminants: organics and
inorganics. Organics-ladened lagoons contain primarily reactive organic
residues that may possibly be converted into nonreactive compounds.
Inorganics-ladened lagoons contain heavy metal concentrations potentially
above the Resource Conservation and Recovery Act (RCRA) extraction
procedure (EP) toxicity limit, which cannot be treated to a nonhazardous
form but can only be recovered or isolated from the environment.
For inorganic wastes, current practice is disposal in a secure landfill.
In many cases long-distance hauling is necessary. An economical
alternative would appear to be chemical fixation followed by onsite
landfilling or disposal in a sanitary landfill. Since fixation
technology is being studied by USATHAMA under a separate contract, no
techniques for restoring lagoons containing inorganic hazardous wastes
were recommended for further study.
The current state-of-the-art technology for hazardous organic materials
is incineration; therefore, incineration serves as a baseline for
evaluating treatment alternatives. The ESE report identified two
promising alternative treatment methods: aqueous thermal decomposition
and solvent extraction. Aqueous thermal decomposition involves the
heating of sediment in an aqueous slurry under pressure to temperatures
of between 200 and 300°C. The solvent extraction technique utilizes an
1-2
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D-THAMA-TASK6.1/SEDR-1.3
07/16/84
organic solvent to leach the hazardous components from sediment, thereby
separating and concentrating the hazardous portion.
Subsequent to the September 1983 report, ESE initiated a laboratory
program to test the feasibility of aqueous thermal decomposition and
solvent extraction. The results of the aqueous thermal decomposition
study will be submitted in a separate report, as will a discussion of the
engineering design of each technology to treat lagoon sediments at three
U.S. Army ammunition plant (AAP) facilities. This report presents the
results of the solvent extraction laboratory study.
"Solvent extraction" is a technique of selectively separating and
removing one or more specific constituents from a mixture by use of a
solvent. There are two major categories of solvent extraction: liquid
extraction and solid extraction. The category applicable to this study
is solid extraction.
i
While liquid extraction and solid extraction have a common basis, a
fundamental difference is that liquid extraction is equilibrium-limited
while solid extraction is not. In other words, in liquid extraction the
amount of solute that can be separated from a mixture by a single contact
is limited by equilibrium relationships among liquids in the mixture. In
solid extraction processes, excess solvent is generally used, and the
effectiveness of a single contact is limited by the ability to physically
separate the liquid and solid fractions.
Solid extraction is often referred to as "leaching." When the soluble
material is largely on the surface of the insoluble solid and is merely
washed off by the solvent, the operation is sometimes called "elution" or
"elutriation." The term leaching is more common and often used
interchangeably with extraction.
1-3
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D-THAMA-TASKS.1/SEDR-1.4
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1.2 REGULATORY CONSIDERATIONS
The majority of U.S. Army lagoons containing organics-contaminated
sediments are the result of munitions production operations. These
lagoons pose a particular problem under RCRA of 1976, which directed the
U.S. Environmental Protection Agency (EPA) to promulgate regulations for
the management of hazardous wastes. In the Title 40 Code of Federal
Regulations (CFR), Part 261, Subpart D, wastewater treatment sludges from
the manufacturing and processing of explosives and pink/red water from
trinitrotoluene (TNT) operations are listed as "hazardous wastes from
specific sources."
Classification as hazardous wastes under Subpart D is independent of the
nature of the sludge and is not affected by any treatment performed on
the sludge. However, Title 40 CFR Part 260.22 does provide for
"delisting" of a particular waste if it can be shown that the waste does
not exhibit the characteristic for which it is listed (i.e., reactivity).
But because protocols for reactivity testing have not been established in
the regulation, there are no criteria for proving the nonreactive nature
of an explosives-processing sludge or the residues from its treatment.
It appears, then, that landfilling of any sludge resulting from the
manufacture of explosives or the residue of its treatment is precluded,
no matter how inert and innocuous the material may be. However, EPA has
in some cases agreed to accept chemical evidence in the place of
reactivity testing to prove that no reactive species are present. In
addition, the U.S. Army is actively working to establish reactivity tests
acceptable to EPA for delisting purposes. Thus, it is reasonable to
expect that in the near future landfilling of sludges from explosives
manufacturing and loading operations will be permitted if it can be shown
that the reactive components have been effectively removed or destroyed.
For purposes of this study, removal to less than 10 milligrams per
kilogram (mg/kg) is assumed to be effective enough for reactivity
delisting.
1-4
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1.3 OBJECTIVES
The objective of this laboratory program was to test the technical
feasibility of using solvent extraction techniques to separate organic
explosives from inert material in lagoon sediments. Experiments were
included to determine operating parameters for design of pilot- and full
scale systems.
Several solvents, including water, benzene, toluene, acetonitrile, and
acetone, were considered for use in the laboratory study. Acetone was
selected as the best solvent for leaching explosives-ladened sediments
because all explosives of interest are quite soluble in it, and also
because acetone is relatively inexpensive, nontoxic, and readily
available in bulk. It is miscible with water in all proportions;
therefore, interfacial effects do not hinder penetration of solvent in
wet sediments.
The solubilities of individual explosives in pure acetone and in pure
water are available in the literature; however, the solubilities in
acetone-water mixtures are not. Because many explosives-contaminated
lagoons are wet, the determination of solubilities of explosives as a
function of the acetone-water ratio in the solvent is necessary for
design of a treatment system. It is also important to know the
solubility of mixtures of explosives in various acetone/water solutions.
To evaluate acetone-water mixtures, a 3-step experimental approach was
used to determine:
1. Individual solubilities of explosives as a function of acetone-
water ratio in the solvent,
2. The effect of mixing explosives on overall solubilities, and
3. The effectiveness of solvent extraction on real sediments.
1-5
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2.0 BASIC PRINCIPLES
In this section some basic principles are discussed. The purpose of this
section is to present concepts necessary to understand the experimental
results. The discussions here are brief. More detailed information can
be obtained from the references cited in this section.
2.1 PHASE EQUILIBRIUM
The TNT/acetone/water, dinitrotoluene (DNT)/acetone/water, and mixed
explosives/acetone/water systems unexpectedly formed two liquid phases in
equilibrium with solid solute. This is probably because of the
hydrophobic nature of TNT and DNT evidenced by their low solubility in
water.
The thermodynamic criteria for phase separation and stability are
expressed in terms of Gibbs free energy. According to Smith and Van Ness
(1975), "The equilibrium state of a closed system is that state for which
the total Gibbs free energy is a minimum with respect to all possible
changes at a given temperature and pressure." Thus, a 2-phase system is
formed if the total Gibbs free energy of the system is lower than that of
a 1-phase system. In a 2-phase system, the individual chemical
components will distribute at equilibrium between the phases such that
their chemical potential is the same in each phase.
It is customary to present ternary phase equilibrium data on triangular
coordinates. Such diagrams contain a wealth of information. Consider,
for example, Figure 2-1, the ternary phase diagram developed in this
study for TNT/acetone/water system at 25°C. The experimental results are
discussed in the next section, but the diagram will be used here to show
the use of triangular coordinates.
The use of triangular phase diagrams, discussed in detail by Treybal
(1980), is based on the fact that the sum of the perpendicular distances
to the sides from any point within an equilateral triangle is equal to
2-1
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D-THAMA-TASK6.1/SEDR-2.2
07/16/84
the altitude of the triangle. Thus, if each apex of the triangle
represents one of the pure components, the perpendicular distance to the
side opposite that apex, divided by the altitude of the triangle, is the
fraction of that component in the mixture. The sum of the three
fractions for any point within the triangle is equal to one.
In Figure 2-1, pure TNT is represented by the top apex, pure water by the
left apex, and pure acetone by the right apex. Points along the base of
the triangle represent acetone/water mixtures with no TNT. The left and
right sides represent water/TNT and acetone/TNT binary mixtures,
respectively. The perpendiculars from each apex to the opposite side are
marked with 100 gradations representing weight-percent values. The point
marked "B," where four curves meet, is 4 units from the base and thus
represents 4-percent TNT. Point B is 51 units from the left side and
45 units from the right. Therefore, the composition at Point B is 4-
percent TNT, 51-percent acetone, and 45-percent water.
Using Figure 2-1, the phase behavior of any mixture of TNT, acetone, and
water at 25°C can be predicted. Mixtures with compositions that fall in
the 3-phase region bounded by Points B, C, and E will consist of two
liquids and a solid. The solid will be pure TNT corresponding to
Point E. The liquid phases will have compositions corresponding to
Points B and C. The relative amounts of each phase will change depending
on the proportion of each component in the starting mixture, but the
composition of the three phases will always correspond to Points E, B,
and C if the overall composition of the system falls in the 3-phase
region.
The lever rule can be used to calculate the relative proportions of the
phases. For example, a starting composition at Point F will have three
phases at equilibrium. Applying the lever rule, a tie line from Point E
through Point F intersects Line BC at Point G. The weight of solid TNT
at equilibrium will be proportional to the length of Line FG divided by
2-2
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D-THAMA-TASK6.1/SEDR-2.3
07/16/84
the length of Line EG. The weight of the two liquid phases together will
be proportional to Line EF divided by Line EG.
The relative amounts of the two liquid phases formed by the mixture at
Point F can be determined by applying the lever rule to Line BGC. The
weight of the water-rich phase corresponding to the composition at
Point B is proportional to Line GC divided by Line BC, and the weight of
the TNT-rich phase is proportional to Line BG divided by Line BC.
There are three separate regions of 2-phase equilibria in the TNT/
acetone/water system. Two regions of liquid-solid equilibria are bounded
by Points A, B, and E and by Points C, D, and E. In these two regions,
solid TNT is in equilibrium with saturated liquid. Tie lines extend from
the TNT apex to the saturation curve as in the 3-phase region.
In the 2-phase liquid-liquid region, a water-rich liquid is in
«»•
equilibrium with a TNT-rich liquid neither of which is saturated with
TNT. In this region it is possible to define tie lines connecting the
equilibrium phase compositions similar to line BGC for the saturated
solutions. The ties usually run in the same general direction as
line BGC but are not necessarily parallel and must be determined
experimentally. It is obvious that the tie lines grow shorter as they
approach the acetone apex and the compositions of the two phases approach
each other. The final point where the phase compositions are equal is
the "plait point." Mixtures richer in acetone than at the plait point
will form a single liquid phase.
2.2 SETTLING TESTS
In order to design sludge thickeners and clarifiers, the settling
velocity of the solid particles must be determined. From the settling
velocity a clear liquid overflow rate can be determined and the vessel
diameter calculated.
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07/16/84
Dilute suspensions of solids generally exhibit three settling regimes.
Initially in the "free settling" regime the individual particles are
separated by fluid and do not interact with one another. As the slurry
settles and becomes more concentrated, particle-particle interactions
become significant and the settling rate slows. This is called the
"hindered settling" regime. Finally, in the "compression" regime, sludge
settles very slowly as particles pack together.
2.3 LEACHING STAGE EFFICIENCY
In a leaching operation where the solid is leached with more than enough
solvent and given sufficient time to dissolve all the soluble portion,
complete removal of solute could be accomplished in one stage if a
perfect separation of solution from the inert solid were possible. In
practice, two phenomena combine to yield stage efficiencies of less than
100 percent: adsorption and entrainment.
•*•
Adsorption is the ability of certain solids to preferentially concentrate
specific substances on their surfaces. Adsorption can be either a
physical or chemical phenomenon, depending on the nature of the materials
involved. It can contribute to the carryover of solute with solids in
leaching operations. Because adsorption is an equilibrium process, the
amount of adsorbed material depends on the concentration of solute in
solution. Depending on the equilibrium relationship, effective removal
of adsorbed solute could require several contact stages.
Entrainment is caused by the imperfect mechanical separation of solids
and solution. Because liquid-solid separations are not perfectly
efficient, some liquid and dissolved solute are retained in the solids.
Entrainment effects can be found by the calculation of a material balance
around the contact stage. The weight of entrained solute can be
calculated from the amount of moisture in the solids leaving the stage
and the concentration of solute in the liquid leaving that stage.
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D-THAMA-TASK6.1/SEDR-2.5
07/16/84
The time required to reach equilibrium depends on the nature of the
leached material. If the solute is mainly on the surface of the
particles and is merely washed off, the approach to equilibrium is rapid.
If the solute is confined in the internal structure of individual
particles, it must diffuse to the surface of the particle before it can
enter the bulk solution. These mass transfer limited leaching processes
are much slower in approach to steady state. Stage efficiencies will be
reduced if contact time is not long enough to reach equilibrium.
2-5
-------
2-PHASE
LIQUID-SOLID
REGION
A /
2-PHASE
LIQUID-SOLID
REGION
/\ TT ncuiura r 7. j
A A/ v v v W
PHASE /
REGION —
/\
\/\/\7\
\
2-PHASE
LIQUID-LIQUID
REGION
\
WATER
ACETONE
Figure 2-1
TNT/ACETONE/WATER PHASE DIAGRAM,
WEIGHT-FRACTION BASIS
SOURCE: ESE, 1984.
USATHAMA
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10/10/84
3.0 EXPERIMENTAL PROCEDURES
This section discusses the experimental methodology and bases for
conducting solvent extraction experiments, the procedures used in
conducting these experiments, and the materials used.
3.1 EXPERIMENTAL MATERIALS
3.1.1 Explosives
The solubilities of 2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene
(DNT), cyclotrimethylenetrinitramine (RDX), and tetryl, individually and
in combination, were determined over a range of water/acetone mixtures.
1,3,5-trinitrobenzene (TNB) was initially scheduled to be included for
solubility testing; however, sufficient quantities of TNB were not
available.
TNT, with 10-percent water added, was purchased from Eastman Kodak
»• -
Company, Rochester, New York. DNT was purchased from Aldrich Chemical
Company, Milwaukee, Wisconsin, and ICN Pharmaceuticals, Cleveland, Ohio.
The DNT and TNT were recrystallized from 95-percent ethanol and dried in
a convection oven.
RDX, wetted with isopropyl alcohol, was received by ESE from the
U.S. Army Armament, Munitions, and Chemical Command (AMCCOM), Rock
Island, Illinois. The RDX was recrystallized from acetone and dried in a
convection oven. The resulting crystals were analyzed
chromatographically by comparison with USATHAMA Standard Analytical
Reference Materials (SARMs) and were found to contain 99.1-percent by
weight RDX and 0.7-percent cyclotetramethylenetetranitramine (HMX).
Tetryl was received from AMCCOM, Rock Island, Illinois. The tetryl, as
obtained, assayed at greater than 99-percent purity by comparison with
USATHAMA SARMs and was used without further purification.
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D-THAMA-TASK6.1/SEDR-3.2
10/10/84
3.1.2 Solvents
High-purity water and distilled-in-glass acetone were purchased from
Burdick and Jackson Laboratories, Inc., Muskegon, Michigan, and used
without further purification.
3.1.3 Sediments
Explosives-contaminated lagoon sediments were required to complete the
experimental program. An ESE representative and the USATHAMA Contracting
Officers Representative (COR) obtained three separate sediment samples
from Ft. Wingate Army Depot (AD) in Gallup, New Mexico; Navajo AD in
Flagstaff, Arizona; and Louisiana Army Ammunition Plant (AAP) in
Shreveport, Louisiana.
At each site, sediment samples were removed from the lagoon with a
plastic scoop and placed in 2-quart glass jars with Teflon® lid liners.
No field preservation was necessary. Upon arrival at ESE's laboratories,
each sediment sample was homogenized separately and stored at 4°C in the
original glass jar.
The physical appearance of the sediments varied. The Navajo AD sediment
was predominately volcanic cinders, the Ft. Wingate AD material was
mostly clay, and the Louisiana AAP sediment was visibly contaminated with
yellow crystals.
3.2 EXPERIMENTAL METHODS
3.2.1 Characterization of Sediments
Each of the three sediments was analyzed for explosives, metals, and
other standard parameters. The results are presented in Table 3-1. The
explosives and moisture data are particularly pertinent to the solvent
extraction testing. The metals, anions, pH, and acidity/alkalinity data,
although shown in Table 3-1, were obtained primarily for consideration in
catalysis of aqueous thermal decomposition of explosives wastes studied
separately under this task order. The data show that the moisture
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10/10/84
Table 3-1. Characterization Data for Sediments Used in Solvent
Extraction and Aqueous Thermal Decomposition Testing
Parameter
pH (Standard Units)
N02 + N03 (mg/kg-dry)
Sulfate (mg/kg-dry)
Total Organic Carbon (g/kg-dry)
Phenols (ug/kg-dry)
Nitrogen, TKN (mg/kg-dry)
Alkalinity (mg/kg-total)
Moisture (%)
Chloride (mg/kg-dry)
Acidity (mg/kg-total)
Total Phosphorus (mg/kg-dry)
Chromium (mg/kg-dry)
Lead (mg/kg-dry)
Aluminum (mg/kg-dry)
Antimony (mg/kg-dry)
Magnesium (mg/kg-dry)
Sodium (mg/kg-dry)
Copper (mg/kg-dry)
Zinc (mg/kg-dry)
Iron (mg/kg-dry)
Barium (mg/kg-dry)
Calcium (mg/kg-dry)
RDX (mg/kg-dry)
HMX (mg/kg-dry)
2,4,6-TNT (mg/kg-dry)
2,4-DNT (mg/kg-dry)
3,5-DNB (mg/kg-dry)
1,3,5-TNB (mg/kg-dry)
Tetryl (mg/kg-dry)
Navajo
AD
6.7
2
<25
21
1,500
990
9.4
24.0
<250
2.10
610
39
120
7,800
<22
10,000
1,300
21
270
14,000
50
7,200
25
34.0
20,000
<500
<250
<330
<250
Ft. Wingate
AD
4.6
0.2
<25
5.8
180
1,000
59
28.0
<250
1,600
27,000
24.0
170
8,300
<23
2,800
8,800
23
120
13,000
230
18,000
1.9
<0.9
730
5.6
1.8
3.9
<1.4
Louisiana
AAP
7.2
21
<25
26.0
NA
51,000
7.8
43.0
<250
4.80
82.0
5.6
<25.0
290
<30
64
38
33
72
1,100
25
510
85,000
11,000
870,000
180
<50
84.0
26,000
Source: ESE, 1984.
3-3
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D-THAMA-TASK6.1/SEDR-3.3
10/10/84
content varied from 23.8 percent to 42.8 percent, and explosives
concentration varied from less than 0.1 percent to almost 99 percent in
the three sediments. Thus, it appears that a good cross section of
sediment types was available for the experimental program.
The explosives were analyzed according to the documented method, using
acetone extraction with high-performance liquid chromatography/ultra-
violet (HPLC/UV) detection (see Appendix A). TNT was the major explosive
of interest, and because of the high TNT levels in the sediments,
substantial dilution of the extracts was required to bring the TNT into
the range of the analytical standard curve. Consequently, the detection
limit of other explosive components varied for the different sediments.
The moisture levels were determined gravimetrically as specified in
Appendix A.
3.2.2 Solubility Experiments
3.2.2.1 Individual Explosives
The solubilities of TNT, DNT, RDX, and tetryl were determined in
water/acetone mixtures, using a modified version of the Organization for
Economic Cooperation and Development (OECD) 1978 water-solubility
protocol.
The size of each sample prepared was selected to yield a volume large
enough for easy sampling without using excessive amounts of materials.
If a particular fraction was expected to form two liquid phases (as
discussed in Section 4.0), a larger sample was prepared so that each
phase could be sampled and analyzed. This was particularly important for
samples in which one phase was disproportionately larger than the other.
The OECD protocol requires periodic reanalysis of a sample fraction to
determine whether equilibrium has been established. Agreement within
15 percent between successive analyses is considered proof of
equilibrium. This was not possible with the explosives/acetone/water
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D-THAMA-TASK6.1/SEDR-3.4
10/10/84
systems in this study. In order to measure the volumes of the two liquid
phases, the entire sample must be transferred from the vial to a
graduated cylinder. During the transfer, evaporation of acetone was
unavoidable, and if the sample was transferred several times, its
composition would change. In order to circumvent this problem,
quadruplicate samples were prepared. Duplicate sets of samples were
anlayzed at least 24 hours apart, and agreement within 15 percent was
taken as proof of equilibrium.
Seven acetone/water mixtures were prepared, with 0, 33, 50, 67, 80, 90,
and 100 weight-percent acetone. The acetone/water ratios were chosen
based on preliminary experiments which indicated more rapid solubility
changes and two-liquid-phase behavior in mixtures with greater than
50 percent acetone. The acetone/water mixtures containing an excess of
the solid explosive (using the literature values of solubility in acetone
and in water as a guideline) were placed in separate amber vials and
sealed with Teflon*-lined Septum caps. The solubility test schemes for
the four explosives are shown in Table 3-2.
The test samples were incubated at 35°C for 24 hours. The temperature of
the incubator was then adjusted and maintained at 25°C, and the samples
were equilibrated for 48 hours. At the end of this period, the liquid
was removed, and the liquid-phase volumes were measured in a graduated
cylinder or test tube. A portion of each liquid phase was removed and
filtered through a 0.45-micron Nylon 66 filter (Rainin Instrument
Company, Woburn, Massachusetts) using a syringe filter. The filtrate was
analyzed using HPLC/UV detection for explosives and using gas
chromatography/thermal conductivity detection (GC/TCD) for water and
acetone.
3.2.2.2 Mixed Explosives
The mixed-explosives solubility test was performed in the same manner as
the individual solubility tests. An excess of TNT, DNT, RDX, and tetryl
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D-THAMA-TASK6.1/SEDR-VTB3-2.1
10/10/84
Table 3-2. Individual Explosives Solubility Test Scheme
Weight-
Percent
Acetone
in Solvent
0
33
50
67
80
90
100
Solvent
(ml)
4
50
50
50
4
4
4
TNT
(gm)
0.3
4
6
14
5
5
6
DNT
ml
4
25
25
25
4
4
4
gm
0.3
2
3
11
5
5
6
RDX
ml
5
25
25
25
5
5
5
gro
0.3
1
2
3
2
2
2.5
Tetryl
ml
4
25
25
25
10
10
4
gin
0.3
3
5
9
7
8
6
Note: ml = milliliters.
gm « grams.
Source: ESE, 1984.
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07/16/84
Table 3-3. Mixed Explosives Solubility Test Scheme
Weight-
Percent
Acetone
in Solvent
0
33
50
67
80
90
100
Solvent
(ml)
4
4
4
10
1
4
1
TNT
(gm)
0.1
4.1
4.1
8.4
5.0
7.5
5.0
DNT
(gm)
0.1
4.1
4.1
8.3
5.0
7.0
5.0
RDX
(gm)
0.1
0.8
0.9
1.1
2.5
1.1
2.5
Tetryl
(gm)
0.1
0.6
0.6
1.7
2.5
2.5
2.5
Source: ESE, 1984.
3-7
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D-THAMA-TASK6.1/SEDR-3.5
10/10/84
was added to each sample. Because the combined explosives had enhanced
solubilities over individual explosive solubilities, several additions of
explosives were necessary to achieve saturation. These experiments were
not duplicated because of the large quantities of explosives required.
The final test scheme is shown in Table 3-3.
3.2.3 Leach Rate Experiments
Leach rate experiments were conducted on the three sediments to determine
the contact time required for equilibration of the explosives between the
leachate and the sediment. Ratios of acetone to sediment were selected
so that the water present in the sediment would dilute the acetone to
90 percent by weight. The results of the solubility experiments were
used to make sure the solubility limits were not exceeded. The levels of
explosives naturally occurring in the sediments were less than one-half
the levels required for saturation of the 90-percent acetone leachate.
Because of the high percent of moisture and high levels of explosives in
the Louisiana AAP sediment?- the sediment was diluted 1:1 with masonry
sand. The test scheme for the leach rate tests is presented in
Table 3-4.
Table 3-4. Leach Rate Test Scheme
Acetone
Sediment
Masonry
(ml)
(gm)*
Sand (gm)
Ft. Wingate
AD
285
90
—
Mavajo
AD
285
105
—
Louisiana
AAP
285
61.3
61.3
*As received.
Source: ESE, 1984.
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D-THAMA-TASK6.1/SEDR-3.7
10/10/84
respectively. The stream designators in the squares at the bottom
represent the final simulated streams which are sampled and analyzed.
In Stage 1A, fresh sediment and fresh acetone are contacted and
separated. The liquid portion is discarded, and the solids are carried
over to Stage 2A and contacted with fresh solvent. The liquid from
Stage 2A is contacted with fresh sediment to form Stage IB. The solids
from Stage 2A are contacted with fresh solvent to make Stage 3A. At this
point, Stage IB and Stage 3A have been prepared. In Step 4, the proper
liquid and solid portions are discarded or carried on for Stage 2B and
Stage 4A.
This process is repeated until a liquid stream and a solid stream that
have contacted four stages are obtained, which occurs in Step 7 for the
liquid stream and Step 8 for the solid stream. In the scheme shown in
Figure 3-1, the procedure is taken through Steps 9 and 10 to assure
steady-state conditions.
The countercurrent leaching experiments were conducted in 1-liter
graduated cylinders with ground-glass stoppers. Each contact stage was
manually shaken vigorously for 30 minutes. Solid-liquid separation was
accomplished by vacuum filtering through Whatman No. 4 filter paper.
The quantity of sediment used in the experiment was selected to yield a
final solid sample large enough to analyze, while keeping solvent usage
and waste generation low. The quantity of acetone was selected to yield
a final liquid stream of approximately 10-percent water in the solvent
and also yield a final explosives concentration below saturation. The
10-percent water criterion was selected based upon the solubility
experiments. The quantities used are shown in Table 3-5.
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D-THAMA-TASK6.1/SEDR-3.8
10/10/84
Table 3-5. Countercurrent Extraction Feed Scheme
Sediment Source
Ft. Wingate AD
Navajo AD
Louisiana AAP
Sediment Quantity (gm)
140
140
210
Acetone Quantity
450
385
675
(ml
Source: ESE, 1984.
The final liquid stream and intermediate streams were analyzed using
HPLC/UV detection for explosives content and GC/TCD for acetone and water
content. The solid samples were extracted using the method detailed in
Appendix A and analyzed for explosives content using HPLC/UV detection.
3.2.5 Settling Tests
Settling tests were performed with Ft. Wingate AD and Navajo AD
sediments. The tests were performed in the 1-liter graduated cylinders
used for the countercurrent leaching simulation using acetone/water
ratios corresponding to Stage 1. No test was performed with the
Louisiana AAP sediment because of its low concentration (2 percent) of
inert solids.
The sediment/acetone/water mixtures were initially shaken to suspend the
inert particles. After shaking, the height of the sludge/clear liquid
interface was measured at 15-second intervals. As the settling rate
decreased, sludge height measurements were taken at longer intervals.
The experiment was terminated after 60 minutes as the settling rate
slowed in the compression regime.
At the end of the settling tests, the supernatant was filtered through
tared Whatman No. 42 filter paper. The paper was air dried and weighed
to determine the suspended solids content of the supernatant.
3-11
-------
(STAGE) g (STAGE) e (STAGE) c (STAGEJ s
uxi / 1 »V2>/ 2 •v»y 3 >V4>^
STEP 1
STEP 2
STEP 3
STEP 4
STEPS
STEP 6
STEP 7
STEPS
STEP 9
STEP 10
SF s FRESH SEDIMENT
LF = FRESH ACETONE
Figure 3-1
FOUR-STAGE COUNTERCURRENT
LEACHING SIMULATION
SOURCE: ESE. 1984.
USATHAMA
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D-THAMA-TASK6.1/SEDR-4.1
07/16/84
4.0 EXPERIMENTAL RESULTS
4.1 INDIVIDUAL EXPLOSIVE SOLUBILITIES
The results of the ternary system solubilities of individual explosives
in acetone/water mixtures are presented in this section. The ternary
systems investigated were:
o TNT/acetone/water,
o DNT/acetone/water,
o RDX/acetone/water, and
o Tetryl/acetone/water.
4.1.1 TNT Solubility
When the TNT/acetone/water solutions were prepared, the 67-, 80-, and
90-percent acetone samples split into a water-rich top phase and a
TNT-rich bottom phase.
The analytical results of^the TNT/acetone/water experiments are shown in
Table 4-1. Compositions of the water-rich fractions, including the
1-phase, 0-, 33-, and 50-percent acetone samples, are listed in the
left-side columns of the table. Data listed in the right-side columns
are for the TNT-rich fractions, including the 1-phase 100-percent acetone
sample.
Figure 2-1 was generated from the analytical solubility data, augmented
with physical titration experiments and assumptions based on knowledge of
similar ternary systems. Curve ABCD, based on the solubility experiment
data, is the saturation curve for TNT in acetone/water.
Curve BC, between the 2-phase liquid-liquid region and the 1-phase
region, was defined using two types of titration experiments. In the
first set of experiments, binary mixtures of acetone and water
(represented by Points A, B, C, D, and E in Figure 4-1) were titrated
with pure TNT until the solution became cloudy, indicating the onset of
2-phase behavior. Incremental addition of TNT drives the concentration
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07/09/84
Table 4-1. TNT Solubility in Acetone/Water
Initial
Weight-
Percent
Acetone
0
33
50
67
80
90
100
Water-Rich Fractions
Volume
Percent
100
100
100
61.7
13.3
2.4
0
Weight
Fraction
Water Acetone TNT
0.9999
0.68
0.51
0.43
0.45
*
—
0 0.0001
0.32 0.002
0.47 0.02
0.53 0.04
0.51 0.04
* *
— —
Volume
Percent
0
0
0
38.3
86.7
97.6
100
INT-Rich Fractions
Weight Fraction
Water Acetone
— —
— —
— —
0.05 0.50
0.05 0.43
0.05 0.45
0 0.43
TNT
—
—
—
0.45
0.52
0.50
0.57
* No sample.
— One liquid phase.
Source: ESE, 1984.
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D-THAMA-TASK6.1/SEDR-4.2
07/16/84
toward the top apex of the triangle, as shown by the arrows. Titration
was continued through the 2-phase region until solids appeared, further
defining the boundary between the 2-phase and 3-phase regions.
In the second set of titrations, binary mixtures of acetone and TNT
corresponding to Points F, G, H, I, and J in Figure 4-1 were titrated
with water until cloudiness was observed.
In order to establish the boundaries between the 3-phase region and the
two 2-phase regions, published phase diagrams were examined. The
naphthalene/acetone/water system exhibits phase behavior similar to that
of TNT/acetone/water. The 3-phase region in Figure 2-1 bounded by
Lines EB, BC, and CE was defined by analogy with the acetone/water/
naphthalene system discussed by Francis (1963). It was assumed that TNT
does not complex with water or acetone, so Lines EB and CE end at the
apex representing pure TNT.,
There are three separate regions of 2-phase equilibria in the
TNT/acetone/water system. Two regions of liquid-solid equilibria are
bounded by Points A, B, and E and by Points C, D, and E. In these two
regions, solid TNT is in equilibrium with saturated liquid. In the
2-phase liquid-liquid region, a water-rich liquid is in equilibrium with
a TNT-rich liquid, neither of which is saturated with TNT.
For the purpose of designing a solvent leaching system, the 1-phase
region is most important. All compositions in this region exist as a
single liquid phase.
The solubility curve for TNT as a function of acetone/water ratio in the
solvent is shown in Figure 4-2 on rectangular coordinates. The curve
diverges at 53-percent acetone in solvent. The top branch is the total
solubility of TNT in the two phases. It should be noted that because
saturated solutions with 53-percent to 91-percent acetone in the solvent
4-3
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D-THAMA-TASK6.1/SEDR-4.3
07/16/84
split into two phases, this line is calculated by combining the TNT in
the separate phases. Single liquids corresponding to this line do not
exist.
The lower of the two lines is the boundary between 1-phase and 2-phase
behavior. The area below this line represents the range of good
operation for a solvent leaching process. It can be seen that the
solubility of TNT does not increase substantially until the acetone
fraction in the solvent is greater than 40 percent. The solubility is
highest between 80-percent and 100-percent acetone.
4.1.2 DNT Solubility
Analytical results of the DNT solubility experiments are listed in
Table 4-2. The phase equilibrium diagram (Figure 4-3) is similar to that
for TNT/acetone/water. The point at which two liquid phases appear is
shifted to the left and tKe 2-phase region is smaller, but the phase
diagram exhibits the same features.
The DNT/acetone/water phase diagram was developed in the same manner as
the TNT/acetone/water phase diagram. The DNT saturation line was
determined from the solubility tests. The shape of the boundary between
the two liquid phases and the 1-phase region is the result of titration
experiments. The boundaries between the two separate liquid-solid
regions and the 3-phase region result from the assumption that no
DNT/water or DNT/acetone complexes occur.
The solubility curve for DNT as a function of acetone/water ratio in the
solvent is shown in Figure 4-4. The 2-liquid-phase region extends from
50-percent to 91-percent acetone in the solvent. Again, the position of
the upper curve was calculated from the composition and relative amounts
of the water-rich phase and DNT-rich phase. As with TNT, the solubility
of DNT does not increase appreciably until the concentration of acetone
in the solvent exceeds 40 percent.
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D-THAMA-TASK6.1 /SEDR-VTB-4-2.1
07/09/84
Table 4-2. DNT Solubility in Acetone/Water
Initial
Weight-
Percent
Acetone
0
33
50
67
80
90
100
Volune
Percent
100
100
100
46.1
11.9
Trace
0
Water-Rich
Fractions
Weight Fraction
Water
100
0.65
0.49
0.44
0.48
*
—
Acetone DNT
0 0.0002
0.35 0.0004
0.49 0.02
0.51 0.05
0.47 0.05
* *
— —
Volune
Percent
0
0
0
53.9
88.1
<100
100
DNT-Rich Fractions
Weight Fraction
Water Acetone
— —
— —
— —
0.05 0.49
0.05 0.48
0.03 0.49
0 0.43
DNT
—
—
—
0.46
0.47
0.48
0.57
* No sample.
— One liquid phase.
Source: ESE, 1984.
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"-THAMA-TASK6.1/SEDR-4.4
07/16/84
4.1.3 Tetryl Solubility
Results of the tetryl solubility experiments are listed in Table 4-3 and
graphically depicted in Figure 4-5. The tetryl/acetone/water system does
not exhibit liquid-liquid 2-phase behavior. All of the saturated
solutions exist as a single liquid in equilibrium with solid tetryl.
Table 4-3. Tetryl Solubility in Acetone/Water
Weight Fraction
Acetone in Solvent 0 0. 33 0.50 0.67 0.80 0.90 1.00
Tetryl in Solution 0.00003 0.001 0.009 0.071 0.204 0.314 0.397
Source: ESE, 1984.
It can be seen from Figure 4-5 that tetryl is sparingly soluble in
acetone/water mixtures with less than 50-percent acetone. The solubility
increases rapidly with increasing acetone concentration in the solvent
after this point.
4.1.4 RDX Solubility
The solubility of RDX in acetone/water mixtures is shown in Table 4-4 and
Figure 4-6. This system does not exhibit liquid-liquid 2-phase behavior.
Table 4-4. RDX Solubility in Acetone/Water
Weight Fraction
Acetone in Solvent 0 0.33 0.50 0.67 0.80 0.90 1.00
Tetryl in Solution 0.00004 0.001 0.006 0.020 0.048 0.069 0.085
Source: ESE, 1984.
4-6
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D-THAMA-TASK6.1/SEDR-4.5
07/16/84
As with the other explosives studied, the solubility of RDX is very low
in acetone/water mixtures with less than 50-percent acetone. The
solubility increases monotonically to a maximum at 100-percent acetone.
4.2 MULTICOMPONENT SOLUBILITY
To determine whether there is competition for solubilization among the
explosives, acetone/water mixtures were saturated with all four of the
explosives simultaneously (a 6-component system). If competition occurs,
one or several of the compounds could be precipitated out as others
dissolve.
The results of the multicomponent experiments are shown in Table 4-5.
Material balances, calculated for each sample for all four explosives,
showed that all samples contained excess solid phase of all explosives,
with the exception of the 67-percent acetone fraction and the 80-percent
acetone fraction. These two samples were saturated with RDX and tetryl
but not with TNT or DNT. The top phase of the 90-percent acetone
fraction was too small to sample.
It can be seen in Table 4-5 that the bottom phase of the 33-, 50-, and
90-percent acetone fractions had 95-percent acetone in the solvent. The
top phase of the 33- and 50-percent fractions had approximately
18-percent acetone in the solvent. Concentrations of the explosives in
all bottom phases were the same within experimental error. Explosives
concentrations in the top phase were also the same.
Thus, the 6-component system behaves in the same manner as the DNT and
TNT ternary systems. The explosives concentration data are plotted on
rectangular coordinates in Figures 4-7 through 4-10. These graphs
indicate that all saturated 6-component mixtures with acetone
concentrations in the initial solvent between 18 percent and 95 percent
will form two liquid phases with constant compositions.
4-7
-------
D-THAMA-TASK6.1/SEDR-HTB4-5.1
07/16/84
Table 4-5. Solubility of Explosives in Multicomponent System
Weight Fraction
Fraction
0
33
Top Phase
33
Bottom Phase
50
f" Top Phase
00
50
Bottom Phase
67
Top Phase
67
Bottom Phase
80
Top Phase
80
Bottom Phase
Parameter
X
X1
X
X'
X
X1
X
X1
X
X1
X
X'
X
X1
X
X'
X
X1
RDX
0.00005
0.00005
0.00014
0.00014
0.021
0.126
0.00019
0.00019
0.025
0.134
0.00044
0.00044
0.029
0.111
0.00033
0.00033
0.025
0.142
Tetryl
0.00001
0.00001
0.00003
0.00003
0.049
0.253 '
0.00004
0.00004
0.031
0.163
0.00006
0.00006
0.026
0.100
0.00006
0.00006
0.063
0.291
TNT
0.00009 .
0.00009
0.00033
0.00032
0.372
0.720
0.00043
0.00043
0.372
0.701
0.00078
0.00078
0.343
0.597
0.00057
0.00057
0.352
0.696
DNT Acetone in Solvent
0.00015 0
0.00015
0.00058 0.16
0.00057
0.413 0.95
0.741
0.00080 0.19
0.00080
0.413 0.95
0.722
0.00151 0.25
0.00151
0.371 0.96
0.616
0.00117 0.22
0.00113
0.405 0.95
0.725
-------
D-THAMA-TASK6.1/SEDR-HTB4-5.2
10/10/84
Table 4-5. Solubility of Explosives in Multicomponent System (Continued, Page 2 of 2)
Weight Fraction
Fraction
90
Bottom Phase
100
Parameter
X
X'
X
X1
RDX
0.024
0.132
0.026
0.158
Tetryl
0.051
0.240
0.052
0.274
TNT
0.375
0.701
0.363
0.726
DNT Acetone in Solvent
0.391 0.95
0.709
0.423 100
0.755
NOTE: X = Weight fraction of individual explosive in solution.
X1 = Weight fraction of individual explosive in solution (other-explosives-free basis).
Source: ESE, 1984.
10
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D-THAMA-TASK6.1/SEDR-4.6
07/16/84
Weight fractions of all individual explosives in the saturated multi-
component systems are less than weight fractions in the respective
ternary explosive/acetone/water solutions. However, the amount of final
solution obtained from a given amount of initial solvent is much larger
in the multicomponent system than in the ternary system. For example,
the 100-percent acetone solvent sample started as 4 milliliters (ml) of
acetone, with a density of 0.8 gram per cubic centimeter (gm/cc). The
final saturated solution was 21 ml, with a density of 1.3 gm/cc. The
solution was viscous and contained 86-percent total explosives. The
bottom phase of the saturated 2-phase samples contained 84-percent total
explosives.
To eliminate this effect and compare solubilities in the multicomponent
system to those in the individual ternary systems, the concentrations
were calculated on an "other-explosives-free" basis. This parameter, X1,
is defined as the weight of the individual explosive of interest, divided
by the sum of that explosive plus acetone plus water.
For example: X'JN-J- = (grams of TNT)/(grams of TNT + acetone + water).
This parameter is plotted with the corresponding ternary solubility data
in Figures 4-11 through 4-14. It can be seen in these figures that the
weight of individual explosive per unit weight of solvent is
significantly higher in the multicomponent systems than in the ternary
systems for TNT, DNT, and RDX. The number of grams of tetryl per gram of
solvent is approximately 40 percent lower in the multicomponent system.
This indicates TNT, DNT, and RDX are chemically compatible in solution
and help solubilize each other. Tetryl is apparently less compatible in
the multicomponent system and thus exhibits decreased solubility in the
6-component system.
4-10
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D-THAMA-TASK6.l/SEDR-4.7
07/16/84
4.3 LEACH RATE TESTS
The leach rate test results are shown in Figures 4-15 and 4-16. Only TNT
concentrations were high enough to quantify in the Navajo AD and
Ft. Wingate AD sediment tests. The levels of TNT, RDX, and tetryl were
high enough to quantify in the Louisiana AAP leachate.
As shown in Figure 4-15, TNT concentrations in the Ft. Wingate AD and
Navajo AD leachates reached steady-state conditions before the first
10-minute period ended. The Louisiana AAP leachate, which is much more
concentrated than the other two leachates, took 20 to 30 minutes to
approach steady-state conditions, as shown in Figure 4-16.
4.4 COUNTERCURRENT EXTRACTION
4.4.1 Ft. Wingate AD Sediment
The results of the 4-stage countercurrent extraction of Ft. Wingate AD
sediment are shown schematically in Figure 4-17. The circles represent
contact stages, and the individual stage efficiencies are shown within
the circles. Parameters which characterize each of the liquid and
sediment streams are also shown.
Only TNT was present in sufficient levels for removal efficiencies to be
calculated. The feed sediment (Sp) contained 1,240 mg/kg TNT on a
dry-weight basis. The first contact stage reduced the sediment TNT
concentration to 141 mg/kg, for a 1-stage removal efficiency of
88.6 percent. After 2 stages, the TNT concentration was 23.5 mg/kg,
giving a 2-stage removal of 98.1 percent. After 3 stages, the TNT
concentration was 8.1 mg/kg, a 3-stage removal of 99.3 percent. After
4 contact stages, the final extracted solid (84) contained 6.0 mg/kg of
TNT, which represents 99.5-percent overall removal efficiency.
The final extract (Lj) was 90.6-percent acetone and 9.4-percent water.
The extract contained 260 milligrams per liter (mg/1) of TNT. Referring
to Figure 4-1, it can be seen that this concentration is well below the
4-11
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D-THAMA-TASK6.1/SEDR-4.8
07/16/84
solubility limit of TNT and well out of the 2-liquid-phase region. In
fact, no liquid-liquid 2-phase behavior was observed in the extract.
The normalized TNT concentration in the liquid is plotted against liquid
stream number in Figure 4-18. The TNT concentration of each stream is
normalized by dividing its value by the value in L^. The data presented
in Figure 4-18 show that, as expected in countercurrent processes, most
of the solute is transferred to the liquid in the first stage.
In Figure 4-19, the normalized liquid TNT concentrations for l>2, 1-3, and
1,4 are shown. The upper curve represents the measured experimental data.
The lower curve represents calculated concentrations that can be
attributed to entrainment of liquid with the solid stream. The purpose
of Figure 4-19 is to determine whether adsorption of TNT on the inert
substrate will be a major consideration in process design. As would be
expected, entrainment causes most of the stage inefficiency. However,
adsorption is probably the main cause of the low removal efficiency in
Stage 4, because of the low entering concentration of explosives.
It should be noted that some of the apparent adsorption effect could be
caused by inaccuracies in the percent-moisture determinations. After
filtering of the leached sediment, the acetone solvent evaporated
rapidly, and accurate moisture values were difficult to obtain.
Figure 4-20 is a plot of normalized TNT concentrations in the sediment-
versus-sediment stream number. It can be seen that most of the TNT was
removed in the first stage, and removal decreases with subsequent stages.
While the removal efficiencies in Stage 1 and Stage 2 were similar,
Stage 1 removed more than 9 times as much TNT as Stage 2.
The results of a settling test performed with Ft. Wingate AD sediment are
shown in Figure 4-21. The vertical axis represents normalized sludge
height and the horizontal axis represents time. The normalized sludge
4-12
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D-THAMA-TASK6.l/SEDR-4.9
07/16/84
height is the height of the sludge/clear liquid interface at time "t"
divided by the initial sludge height (t=0).
On this figure the classical settling regimes can be seen. The settling
velocity in the free settling regime is 0.5 centimeter per minute. The
total suspended solids (TSS) content of the supernatant was 100 mg/1.
4.4.2 Navajo AD Sediment
The results of the 4-stage countercurrent extraction of Navajo AD
sediment are shown in Figure 4-22. The circles represent contact stages,
and the stage efficiencies are shown within the circles. Liquid and
sediment parameters are also presented.
As with the Ft. Wingate AD sediment, only TNT was present in sufficient
quantities to calculate removal efficiencies. The feed sediment (Sp)
contained 19,300 mg/kg (1.9" percent) of TNT on a dry-weight basis. The
first stage reduced the sediment TNT concentration to 2,350 mg/kg. This
is a 1-stage removal of 87.8 percent. After 2 stages, the TNT
concentration was 231 mg/kg, giving a 2-stage removal of 98.8 percent.
After 3 stages, the TNT concentration was 40.3 mg/kg, a 3-stage removal
of 99.8 percent. The final extracted solid (84) contained 7.0 mg/kg of
TNT. The overall removal efficiency was 99.96 percent.
The final extract (LJ) was 90.9-percent acetone and 8.6-percent water.
The extract contained 5,500 mg/1 of TNT, which is well below saturation
and outside the 2-liquid-phase region.
The normalized TNT concentration in the liquid is plotted against liquid
stream number in Figure 4-23. This figure shows that, as with
Ft. Wingate AD sediment, most of the TNT was dissolved in the first
stage.
4-13
-------
D-THAMA-TASK6.I/SEDR-4.10
07/16/84
Figure 4-24 is a graph of the relative contribution of entrainment and
adsorption in decreasing the extraction stage efficiencies. The TNT
concentration in the Navajo AD sediment entering Stage 4 is much higher
than in the Ft. Wingate AD sediment entering Stage 4 (40.3 mg/kg versus
8.1 mg/kg). At the higher TNT concentration, adsorption does not have as
great a detrimental effect on efficiency, so Stage 4 efficiency is
80.0 percent.
Figure 4-25 is a plot of normalized TNT concentration as a function of
stage number for the Navajo AD sediment experiments. Most of the TNT was
removed in the first stage. Removal efficiencies per stage were
approximately 90 percent for Stage 1 and Stage 2 and approximately
80 percent for Stage 3 and Stage 4.
A settling test was performed on the Navajo AD sediment. The curve,
shown in Figure 4-26, has Che same characteristics as the curve for the
Ft. Wingate AD sediment settling test. The free settling velocity is
1.3 centimeters per minute. The supernatant TSS was 50 mg/1.
4.4.3 Louisiana AAP Sediment
The sediment obtained from Louisiana AAP contained approximately
98 dry-weight-percent explosives. One of the main criteria for design of
the countercurrent extraction experiment is that the amount of inerts
must be large enough to analyze after leaching. If the Louisiana AAP
sediment were used as obtained, a large amount of sediment and acetone
would be required. In addition, previously reported levels of explosives
in Louisiana AAP sediments were much lower than levels in these samples,
so the sediment was mixed with clean soil to approximately 40-percent
explosives.
The results of the 4-stage countercurrent extraction of Louisiana AAP
sediment are shown schematically in Figure 4-27. Only TNT concentrations
in the sediment were high enough to follow through all 4 stages. The
4-14
-------
D-THAMA-TAS K6.1/SE DR-4.11
07/16/84
removal efficiencies shown on Figure 4-27 are for TNT. RDX could be
quantified in Sp, Sj, and 82- Stage 1 and Stage 2 RDX removal
efficiencies are, respectively, 89.0 percent and 98.5 percent. TNB was
quantified in Sp and Sj. Stage 1 removal efficiency for TNB was
88.8 percent.
These results show that stage efficiencies are relatively independent of
the compound on which the calculation is based. Stage 1 efficiencies
were 89.8 percent, 89.0 percent, and 88.8 percent for TNT, RDX, and TNB,
respectively. Stage 2 efficiencies were 98.9 and 98.5 percent for TNT
and RDX, respectively.
The feed sediment (SF) contained 38-percent TNT, 3.7-percent RDX, and
58-mg/kg TNB on a dry-weight basis. Using TNT as the basis for
calculating cumulative efficiencies, the first stage removed TNT to
38,000 mg/kg for an 89.8-percent removal. The sediment from Stage 2
contained 430 mg/kg TNT. This is a 2-stage removal of 99.89 percent.
After 3 stages, the TNT concentration was 83 mg/kg, giving a 3-stage
removal efficiency of 99.98 percent. The final extracted sediment
contained 17.3 mg/kg of TNT and undetectable levels of RDX and TNB, which
represents 99.995-percent removal based on TNT concentration. If the
removal were based on the change of the weight of TNT rather than the
change in concentration, the removal efficiency would be 99.998 percent.
The final extract (Lj) is 83.0-percent acetone, 6.2-percent water,
9.8-percent TNT, 1.0-percent RDX, and 32-mg/kg TNB on a weight basis.
The solvent, excluding explosives, is 93.2-percent acetone and
6.8-percent water. The concentration of TNT is well below its individual
saturation level in 93.2-percent acetone.
The concentration of RDX calculated on a TNT-free and TNB-free basis is
1.1 weight-percent in Lj. Referring to Figure 4-13, it can be seen that
this concentration is above the solubility limit of RDX in 93.2-percent
4-15
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D-THAMA-TASK6. l/SEDR-4. 12
07/16/84
acetone in the ternary system. However, 1.1 percent does not exceed the
enhanced multicomponent solubility represented by X'RDX in Figure 4-13.
Liquid-liquid 2-phase behavior was not observed in the extract. Water
was added slowly to a sample of L} to determine whether 2 liquid phases
would appear. The solution split into 2 liquid phases when the solvent
was approximately 71-percent acetone and 29-percent water.
The normalized explosives concentration in the liquid extract is plotted
against liquid stream number in Figure 4-28. Because the stage removal
efficiencies were similar for all compounds that could be quantified,
normalized concentrations fall along the same line.
Figure 4-29 shows the relative effects of entrainment and adsorption on
stage inefficiencies, as discussed earlier. As with the Navajo AD
sediment, entrainment dominates throughout.
Figure 4-30 is a plot of normalized TNT concentration in the sediment.
The RDX and TNB concentrations follow the same line as far as they could
be traced. These concentrations are consistent with the concentrations
for Navajo AD sediment. Stage efficiencies are high throughout.
4-16
-------
EXPLOSIVE
c
WATER
ACETONE
Figure 4-1
TITRATION EXPERIMENTS
SOURCE: ESE, 1984.
4-17
USATHAMA
-------
0621
1.0
0.8
O.S
0.4
0.2
TWO LIQUID
PHASES
T = 25°C
0.2
XA » WEIGHT FRACTION OF ACETONE (TNT-FREE BASIS)
XTNT = WEIGHT FRACTION OF TNT
Figure 4-2
SOLUBILITY OF TNT IN ACETONE/WATER
SOURCE: ESE, 1984.
USATHAMA
4-18
-------
2-PHASE
LIQUID-SOLID
REGION
3-PHASE
REGION
\AA
2-PHASE V /\ ,
LIQUID-SOLID
REGION /
v V
LIQUID-LIQUID
REGION
1-PHASE
REGION
WATER
ACETONE
Figure 4-3
DNT/ACETONE/WATER PHASE DIAGRAM,
WEIGHT-FRACTION BASIS
SOURCE: ESE. 1984.
4-19
USATHAMA
-------
0620
1.0
0.8
0.6
0.4
0.2
25°C
TWO LIQUID
PHASES
0.2
XA - WEIGHT FRACTION OF ACETONE (DNT-FREE BASIS)
XONT = WEIGHT FRACTION OF DNT
Figure 4-4
SOLUBILITY OF DNT IN
SOURCE: ESE, 1984.
ACETONE/WATER
USATHAMA
4-20
-------
06
^TETRYL
0.1
XA = WEIGHT FRACTION OF ACETONE (TETRYL-FREE BASIS)
XTETRYL = WEIGHT FRACTION OF TETRYL
Figure 4-5
SOLUBILITY OF TETRYL IN
ACETONE/WATER
SOURCE: ESE, 1984.
USATHAMA
4-21
-------
oe;
0.20
0.18
0.16
0.14
0.12
0.10
0.08
0.06
0.04
0.02
T = 25°C
XA - WEIGHT FRACTION OF ACETONE (RDX-FREE BASIS)
XROX - WEIGHT FRACTION OF RDX
Figure 4-6
SOLUBILITY OF RDX IN ACETONE/WATER
SOURCE: ESE, 1984.
USATHAMA
4-22
-------
0.5
0.4
0.3
0.2
0.1
T = 25°C
TWO LIQUID
PHASES
0.4
0.6
0.8
Xi
A
X' = WEIGHT FRACTION OF ACETONE IN SOLVENT
(EXPLOSIVES-FREE BASIS)
XTNT = WEIGHT FRACTION OF TNT IN SOLUTION
062084
1.0
Figure 4-7
SOLUBILITY OF TNT IN MULTICOMPONENT
SYSTEM
SOURCE: ESE, 1984.
USATHAMA
4-23
-------
0.5
0.4
0.3
0.2
0.1
06208
T = 25°C
TWO LIQUID
PHASES
T5.2
0.4
0.6
0.8
1.0
X'
A
X' - WEIGHT FRACTION OF ACETONE IN SOLVENT
A (EXPLOSIVES-FREE BASIS)
XDNT 'WEIGHT FRACTION OF DNT IN SOLUTION
Figure 4-8
SOLUBILITY OF DNT IN
MULTICOMPONENT SYSTEM
SOURCE: ESE, 1984.
USATHAMA
4-24
-------
06206
0.10.
0.09
0.08
0.07
0.06
0.05
0.04
0.03
0.02
0.01
T = 25°C
TWO LIQUID
PHASES
0.2
0.4
0.6
0.8
1.0
XA » WEIGHT FRACTION OF ACETONE IN SOLVENT
(EXPLOSIVES-FREE BASIS)
XRDX 8 WEIGHT FRACTION OF RDX IN SOLUTION
Figure 4-9
SOLUBILITY OF RDX IN
MULTICOMPONENT SYSTEM
SOURCE: ESE, 1984.
USATHAMA
4-25
-------
06208.
0.10
0.09
0.08
0.07
0.06
METHYL
0.05
0.04
0.03
0.02
0.01
T = 25°C
JO^
TWO LIQUID
PHASES
•9-3*
0.2
0.4
0.6
0.8
1.0
X'A -WEIGHT FRACTION OF ACETONE IN SOLVENT
A (EXPLOSIVES-FREE BASIS)
XTETRYL - WEIGHT FRACTION OF TETRYL IN SOLUTION
Figure 4-10
SOLUBILITY OF TETRYL IN
MULTICOMPONENT SYSTEM
SOURCE: ESE, 1984.
USATHAMA
4-26
-------
06208-
1.0
0.8
0.6
XTNT
and
V'
ATNT 0.4
0.2
T = 25°C
— TERNARY
O MULTICOMPONENT
TWO LIQUID
PHASES
0.2
0.4
X'
V'
AA
XTNT
X'
ATNT
WEIGHT FRACTION OF ACETONE IN SOLVENT
(EXPLOSIVES-FREE BASIS)
WEIGHT FRACTION OF TNT IN TERNARY SYSTEM
WEIGHT FRACTION OF TNT IN MULTICOMPONENT SYSTEM
(OTHER-EXPLOSIVES-FREE BASIS)
Figure 4-11
COMPARISON OF TNT SOLUBILITY IN
TERNARY AND MULTICOMPONENT
SYSTEMS
SOURCE: ESE. 1984.
USATHAMA
4-27
-------
0«20t
1.0
0.8
0.6
and
DNT
0.4
0.2
T = 25°C
TERNARY
O MULTICOMPONENT
8 <
TWO LIQUID
PHASES
XDNT
X'
DNT
WEIGHT FRACTION OF ACETONE IN SOLVENT
(EXPLOSIVES-FREE BASIS)
WEIGHT FRACTION OF DNT IN TERNARY SYSTEM
WEIGHT FRACTION OF DNT IN MULTICOMPONENT SYSTEM
(OTHER-EXPLOSIVES-FREE BASIS)
Figure 4-12
COMPARISON OF DNT SOLUBILITY IN
TERNARY AND MULTICOMPONENT
SYSTEMS
SOURCE: ESE. 1984.
USATHAMA
4-28
-------
062M
and
Xi
i
RDX
0.20
0.18
0.16
0.14
0.12
0.10
0.08
0.06
0.04
0.02
T = 25°C
TERNARY
O MULTICOMPONENT
O
O
XA - WEIGHT FRACTION OF ACETONE IN SOLVENT
(EXPLOSIVES-FREE BASIS)
XROX = WEIGHT FRACTION OF RDX IN TERNARY SYSTEM
X' = WEIGHT FRACTION OF RDX IN MULTICOMPONENT SYSTEM
RDX (OTHER-EXPLOSIVES-FREE BASIS)
Figure 4-13
COMPARISON OF RDX SOLUBILITY IN
TERNARY AND MULTICOMPONENT
SYSTEMS
SOURCE: ESE. 1984.
USATHAMA
4-29
-------
06201
0.5
0.4
0.3
VETRYL
and
x;
TETHYL
0.2
0.1
T = 25°C
— TERNARY
O MULTICOMPONENT
X' = WEIGHT FRACTION OF ACETONE IN SOLVENT
A (EXPLOSIVES-FREE BASIS)
XTETRYL " WEIGHT FRACTION OF TNT IN TERNARY SYSTEM
Xi
i
TETRYL
WEIGHT FRACTION OF TNT IN MULTICOMPONENT
SYSTEM (OTHER-EXPLOSIVES-FREE BASIS)
Figure 4-14
COMPARISON OF TETRYL SOLUBILITY IN
TERNARY AND MULTICOMPONENT
SYSTEMS
SOURCE: ESE. 1984.
USATHAMA
4-30
-------
(mg/l x 10-2)
t t
> T
FT. WINGATE AD SEDIMENT
I I t I
0 20 40 60 80 100 120
t (minutes)
XTNT
(mg/l x 10-3)
NAVAJO AD SEDIMENT
5,800
_i i
0 20 40 60
80 100 120
t (minutes)
5,800
Figure 4-15
SEDIMENT LEACH RATE— FT.
WINGATE AD AND NAVAJO AD
SOURCE: ESE, 1984.
USATHAMA
4-31
-------
LOUISIANA AAP SEDIMENT
mg/l TETRYL x 10~3
20 40 60
80 100 120
t (minutes)
5,800
Figure 4-16
SEDIMENT LEACH RATE
—LOUISIANA AAP
SOURCE: ESE, 1984.
USATHAMA
4-32
-------
1
u>
CO
450 ml 450 ml 450 ml
90.6% ACETONE 97.5% ACETONE 98.7% ACETONE
260 mg/l TNT 24.9 mg/l TNT 5.1 mg/l TNT
450 ml 450 ml
99.2% ACETONE 100% ACETONE
0.8 mg/ 1 TNT
•*- f ^ / \ / \" / \™
Li / STAGE 1 \ L2 / STAGE 2 \ L3 / STAGES \ L4 / STAGE 4 \ LF
( 88.6% I I 83.3% ) ( 68.4% j 1 16.7% )
SF \ REMOVAL / 8, V REMOVAL / S2 \ REMOVAL I S, V REMOVAL / S4
k^ / )•> / ^c ' "^ ' "^
140 GRAMS 142.1 GRAMS 137.4 GRAMS
25.8% MOISTURE 29.5% MOISTURE 27.9% MOISTURE
1,240 mg/kgTNT 141 mg/kgTNT 23.5 mg/kgTNT
OVERALL REMOVAL: 99.5%
Figure 4-17
COUNTERCURRENT EXTRACTION SIMULATION— FT. WINGATE AD
SOURCE: ESE, 1984.
/ ^^—^
137.1 GRAMS 130.8 GRAMS
26.6% MOISTURE 24.8% MOISTURE
8.1 mg/kgTNT 6.0 mg/kgTNT
2Bp ^TT^) f^-Tf"^ bv ^"^J^N,
USATHAMA
-------
I
t_0
.o
i.o
0.9
0.8
0.7
NORMALIZED °6
TNT
CONCENTRATION
/yLI •«•! • v 0.5
"TNT
0.4
0.3
0.2
0.1
FT. WINGATE AD SEDIMENT
XLTNT= 260 mg/1
T = 25°C
LIQUID STREAM NUMBER
Figure 4-18
NORMALIZED LIQUID TNT
CONCENTRATION IN COUNTERCURRENT
LEACHING—FT. WINGATE AD
SOURCE: ESE. 1984.
USATHAMA
-------
0.20
0.16 •
NORMALIZED
TNT
I CONCENTRATION
u /XL1
/A
0.12
0.08
0.04
FT. WINGATE AD SEDIMENT
T = 25°C
MEASURED
:ONCENTRATIONS
ENTRAINMENT
CONTRIBUTION
LIQUID STREAM NUMBER
Figure 4-19
FT. WINGATE AD ENTRAINMENT EFFECTS
SOURCE: ESE, 1984.
USATHAMA
4-35
-------
10
1.0
0.9
o.a -
0.7 -
0.6
NORMALIZED
TNT
CONCENTRATION
0.5
(YSI /Y$F )
* TNT TNT
0.4
0.3 •
0.2 -
0.1
0 L
FT. WINGATE AD SEDIMENT
= 1,240 mg/kg
TNT
T = 25°C
SEDIMENT STREAM NUMBER
Figure 4-20
NORMALIZED SEDIMENT TNT CONCENTRATION IN
COUNTERCURRENT LEACHING —FT. WINGATE AD
SOURCE: ESE. 1984.
USATHAMA
-------
NORMALIZED
SLUDGE HEIGHT
(Ht/Ho)
FT. WINGATE AD SEDIMENT
HINDERED SETTLING
30
t(minutes)
Figure 4-21
FT. WING ATE AD SETTLING TEST
SOURCE: ESE, 1984.
USATHAMA
-------
385 ml
90.9% ACETONE
5,500 mg/l TNT
385 ml
98.5% ACETONE
617 mg/l TNT
385 ml
99.4% ACETONE
55 mg/l TNT
385 ml
99.6% ACETONE
9.5 mg/l TNT
385 ml
100% ACETONE
SF
STAGE 1
87.8%
REMOVAL
STAGE 2
90.2%
REMOVAL
STAGE 3
83.3%
REMOVAL
STAGE 4
80.0%
REMOVAL
S4
(.0
00
140 GRAMS
25.0% MOISTURE
19,300 mg/kgTNT
128.3 GRAMS
21.9% MOISTURE
2,350 mg/kg TNT
123.8 GRAMS
21.0% MOISTURE
231 mg/kg TNT
127.1 GRAMS
25.9% MOISTURE
40.3 mg/kg TNT
120.2 GRAMS
18.8% MOISTURE
7.0 mg/kg TNT
OVERALL REMOVAL: 99.96%
Figure 4-22
COUNTERCURRENT EXTRACTION SIMULATION— NAVAJO AD
SOURCE: ESE, 1984.
USATHAMA
-------
0.10
0.08
NORMALIZED
TNT
CONCENTRATION
/vti /YLi \
V*TNT/ATNT'
0.06
0.04
0.02
NAVAJO AD SEDIMENT
ENTRAINMENT
CONTRIBUTION
T = 25°C
MEASURED
CONCENTRATIONS
I-4
LIQUID STREAM NUMBER
Figure 4-24
NAVAJO AD ENTRAINMENT EFFECTS
SOURCE: ESE, 1984.
USATHAMA
4-40
-------
062GB
(*>
vO
NORMALIZED
TNT
CONCENTRATION
TNT
1.0
0.9
0.8
0.7
°5
0.4
0.3
0.2
0.1
NAVAJO AD SEDIMENT
XLTNT= 5,500 mg/1
T =25°C
LIQUID STREAM NUMBER
Figure 4-23
NORMALIZED LIQUID TNT
CONCENTRATION IN COUNTERCURRENT
LEACHING--NAVAJO AD
SOURCE: ESE, 1984.
USATHAMA
-------
NORMALIZED
TNT
CONCENTRATION
o.s
TNT TNT
NAVAJO AD SEDIMENT
SEDIMENT STREAM NUMBER
= 19,300 mg/kg
TNT
T = 25°C
Figure 4-25
NORMALIZED SEDIMENT TNT CONCENTRATION IN
COUNTERCURRENT LEACHING —NAVAJO AD
FSF I
-------
062084
NORMALIZED
SLUDGE HEIGHT
(Ht/Ho)
NAVAJO AD SEDIMENT
. I FREE SETTLING
HINDERED SETTLING
X
30
t(minutes)
Figure 4-26
NAVAJO AD SETTLING TEST
SOURCE: ESE, 1984.
USATHAMA
-------
-p-
OJ
675 ml 675 ml 675 ml
83.0% ACETONE 98.7% ACETONE 99.6% ACETONE
90,230 mg/l TNT 4,320 mg/l TNT 103 mg/l TNT
9,490 mg/l RDX 455 mg/l RDX 12 4 mg/l RDX
29 mg/l TNB 1.5 mg/l TNB
675 ml 675 ml
99.8% ACETONE 100% ACETONE
6.4 mg/| TNT
0.8 mg/l RDX
/ \ / ^\ / X~ / \^
Lt / STAGE 1 \ La / STAGE 2 \ L3 / STAGES \ L4 / STAGE 4 \ Lf
f 89.8% J ( 98.9% J | 80.8% ] | 78.9% I
SF \ REMOVAL / S, V REMOVAL j S2 V REMOVAL j S, V REMOVAL / S4
^^ S B^L ^\. "~ "^
210 GRAMS 96.7 GRAMS 87.2 GRAMS
21.2% MOISTURE 17.8% MOISTURE 18.4% MOISTURE
380,000 mg/kgTNT 38,8000 mg/kgTNT 430 mg/kgTNT
37,300 mg/kg RDX 4,090 mg/kg RDX 60 mg/kg RDX
58 mg/kg TNB 6.5 mg/kg TNB
^ ^~ ^
95.8 GRAMS 91.3 GRAMS
21.7% MOISTURE 18.9% MOISTURE
83 mg/kgTNT 17.3 mg/kgTNT
OVERALL REMOVAL: 99.995%
Figure 4-27
COUNTERCURRENT EXTRACTION SIMULATION— LOUISIANA AAP
SOURCE: ESE, 1984.
USATHAMA
-------
062CB4
1.0
0.9
0.8
0.7
NORMALIZED 0.6
EXPLOSIVES
CONCENTRATION
0.5
0.4
0.3
0.2
0.1
LOUISIANA AAP SEDIMENT
vLi
A TNT
vLi
A RDX
YLi
A TNB
= 90,200 mg/1
= 9,500 mg/1
= 30 mg/1
T= 25°C
LIQUID STREAM NUMBER
Figure 4-28
NORMALIZED LIQUID EXPLOSIVES
CONCENTRATION IN COUNTERCURRENT
LEACHING—LOUISIANA AAP
USATHAMA
-------
0.05
0.04
NORMALIZED
EXPLOSIVES
CONCENTRATION
0.03
0.02
0.01
LOUISIANA AAP SEDIMENT
T = 25°C
MEASURED
CONCENTRATIONS
ENTRAINMENT
CONTRIBUTION-
LIQUID STREAM NUMBER
Figure 4-29
LOUISIANA AAP ENTRAINMENT EFFECTS
SOURCE: ESE. 1984.
USATHAMA
4-45
-------
*-
&
NORMALIZED
TNT
CONCENTRATION
0.5
(YSi /YSf )
* TNT TNT
LOUISIANA AAP SEDIMENT
SEDIMENT STREAM NUMBER
Figure 4-30
NORMALIZED SEDIMENT TNT CONCENTRATION IN
COUNTERCURRENT LEACHING—LOUISIANA AAP
USATHAMA
-------
D-THAMA-TASKS.1/SEDR-5.1
07/16/84
5.0 SUMMARY AND CONCLUSIONS
The laboratory study indicated that wet, explosives-ladened sediment can
be effectively decontaminated by leaching with acetone. Three contact
stages reduced the explosives concentration in Ft. Wingate AD sediment to
less than 10 mg/kg. Four contact stages were required to reduce the
explosives concentration in the Navajo AD sediment to less than 10 mg/kg.
The explosives concentration in the Louisiana AAP sediment was 17 mg/kg
after four contact stages. It is apparent that a fifth contact stage
with greater than 50-percent efficiency would reduce the explosives
content to less than 10 mg/kg.
The initial sediment explosives concentration, the final sediment
explosives concentration, and the calculated 4-stage removal efficiencies
are shown in Table 5-1 for all three sediments. The Louisiana AAP
sediment, which was initially the most contaminated, contained the
highest final concentration of explosives after four contact stages, but
•»••*
experienced the highest removal efficiency. The Ft. Wingate AD sediment
was initially the least contaminated, and the final residue had the
lowest concentration of explosives. The Ft. Wingate AD sediment had the
lowest overall removal. The Navajo AD sediment had intermediate initial
contamination and had intermediate final concentration and removal.
Table 5-1. Initial Sediment Explosives Concentration, Final Sediment
Explosives Concentration, and Calculated 4-Stage Removal
Efficiencies
Sediment
Ft. Wingate AD
Navajo AD
Louisiana AAP
Initial
Explosives
Concentration
(mg/kg)
1,200
19,000
420,000
Final
Explosives
Concentration
(mg/kg)
6.0
7.0
17.0
4-Stage
Remova 1
Efficiency
(I)
99.5
99.96
99.996
Source: ESE, 1984.
5-1
-------
D-THAMA-TASK6.l/SEDR-5.2
07/16/84
The individual stage removal efficiencies for all three countercurrent
extraction simulations are plotted in Figure 5-1 against the natural
logarithm (In) of TNT concentration of the sediment entering the stage.
Stage efficiencies are limited to about 90 percent (neglecting the
outlying Louisiana AAP point at 99 percent) by entrainment. The lower-
stage efficiencies at low TNT concentration indicate adsorption
equilibrium limitations.
The different stage requirements necessary to achieve a given degree of
removal or final residue concentration level indicate that a treatment
system based on solvent extraction should have a variable number of
contact stages available. Continuous countercurrent contact devices can
be constructed such that by varying operational parameters such as
residence time, feed-to-solvent ratio, and degree of mixing, the number
of effective stages can be varied.
The individual solubilities of TNT, DNT, RDX, and tetryl and their mixed
component solubilities in acetone/water were found to vary nonlinearly
with acetone fraction in the solvent. In all cases the solubilities are
low in acetone/water mixtures of less than 50-percent acetone. The
solubilities increase continuously from 50-percent acetone to their
maximum at 100-percent acetone in the solvent.
At 25°C, saturated solutions of TNT and of DNT in acetone/water mixtures
of between approximately 50-percent acetone and 90-percent acetone form
two liquid phases in equilibrium with solid solute. The less dense, top
phase consists of approximately equal proportions of acetone and water
with 4- or 5-percent solute. The denser bottom phase consists of
approximately equal proportions of solute and acetone with 5-percent
water.
The solubility results should be used to select the feed-to-solvent ratio
for the solvent extraction treatment system. Both the amount of water
5-2
-------
D-THAMA-TASK6.I/SEDR-5.3
07/16/84
and the concentration of explosives should be considered. The total
amount of solvent should be in excess of that needed to solubilize all of
the explosives at the acetone/water ratio established.
The region of liquid-liquid 2-phase behavior should be avoided in the
leaching operation. Liquid-liquid interfacial tension could hinder
penetration of solvent through the sediment.
5-3
-------
14
12
10
8
In TNT
CONCENTRATION
A FT. WINGATE AD SEDIMENT
• NAVAJO AD SEDIMENT
• LOUISIANA AAP SEDIMENT
I
•
20
40 60
PERCENT REMOVAL
80
100
Figure 5-1
STAGEWISE TNT REMOVALS VERSUS
ENTERING TNT CONCENTRATIONS
SOURCE: ESE, 1984.
USATHAMA
5-4
-------
D-THAMA-TASK6.1/SEDR-6.1
10/10/84
6.0 CONCEPTUAL TREATMENT SYSTEM DESIGN
A conceptual design for Che solvent extraction treatment system was
developed to provide information for USATHAMA to estimate capital and
operating costs. Cost estimates are being prepared in conjunction with
Engineering-Science and will be published in "Cost Analysis Methodology
Development for Installation Restoration Development."
Figure 6-1 is the process flow diagram for the solvent extraction system.
The sediment is milled under water to reduce the particle size. The wet
milled sediment (50 percent moisture) is then screw conveyed to the
extractor. The screw conveyor is sloped toward the mill and will dewater
the sediment to approximately 30 percent water. Feed sediments with
greater than 30 percent water will generate excess water at the mill.
Sediments with less than 30 percent water will require make-up water to
the mill (shown as negative flow on material balance). Make-up water
will be recycled from the solvent recovery still. Excess water and
standing water in the lagoon will be treated by granular activated
carbon.
In the extractor, sediments are screw conveyed upward and mixed with
acetone which flows countercurrent to the sediment. Clean, acetone-wet
solids enter the dryer where they are heated by indirect contact with hot
oil. The solids are conveyed through the continuous dryer and exit as
clean, dry solids, suitable for landfilling in a cleared empty lagoon at
the site. Vapors from the dryer go to the overhead condenser of the
solvent recovery column.
The explosives-ladened solvent (extract) overflows the hopper on the
extractor to an extract tank where entrained solids settle. The extract
is filtered and then preheated in a feed/distillate heat exchanger. In
the solvent recovery column the extract is split into three streams. The
overhead stream is the recovered solvent which is 97 percent acetone and
6-1
-------
COOLANT
t-o
n r
Figure 6-1
SOLVENT EXTRACTION SYSTEM
PROCESS FLOW DIAGRAM
USATHAMA
-------
D-THAMA-TASK6.1/SEDR-6.2
10/10/84
3 percent water. The column bottoms go to an insulated settler where
molten explosives phase-separate from the water.
The molten explosives will be burned in the hot oil heater to provide
heat for the process. It may be necessary to blend the explosives with
fuel oil or acetone for safety purposes prior to burning. With heavily
contaminated sediments the explosives can provide a significant portion
of process heat requirements.
The water from the settler is heated in the reboiler and returned to the
column. Water is removed from the column as a liquid side-stream at
100°C. The explosives concentration in the water is expected to be less
than 0.001 mg/1. The acetone content will be less than 100 mg/1. If
100 mg/1 acetone is too high for direct discharge or treatment in an
existing treatment facility, an auxiliary distillation column can be used
to reduce the acetone concentration further.
All equipment that contains acetone will be maintained at slight positive
pressure (several inches of water column) with nitrogen for fire
prevention.
Material balances were generated for decontamination of pink-water
lagoons at Cornhusker AAP, Savannah AD Activity, and Louisiana AAP. The
material balances are based on cleanup of Cornhusker AAP lagoons in
1 year, Savannah AD Activity lagoons in 2 years, and Louisiana AAP
lagoons in 5 years. The material balances for Cornhusker AAP, Savannah
AD Activity, and Louisiana AAP are presented in Tables 6-1, 6-2, and 6-3,
respectively. The stream numbers in the tables correspond to the stream
numbers on the block diagram (Figure 6-2).
6-3
-------
FUEL
FRESH
SOLVENT
FEED
SEDIMENT
*l
SOLVENT
RECOVERY
STILL
H
to Mnl
*•
FURNACE
1
WATER
CONTAMINATED WATER
TO TREATMENT
CLEAN
SOLIDS
Figure 6-2
SOLVENT EXTRACTION SYSTEM BLOCK DIAGRAM
USATHAMA
-------
D-THAMA-TASK6.1/SEDR-VTB61.1
10/10/84
Table 6-1. Cornhusker AAP Solvent Extraction Material Balance
Stream Explosive Inerts
Number (Ib/hr) (Ib/hr)
1 41 4,107
2
3 41 4,107
4
5 — 4,107
6 41
7
8 <10 mg/kg 5,107
9
10 41
11 <1 ug/1 —
12
Water Acetone
(Ib/hr) (Ib/hr)
1 , 102
-631
1,733
83 2,694
31 995
1,785 1,699
31 995
—
52 1,699
1,102 <100 mg/1
15
Total
(Ib/hr)
5,250
-631
[1.26]
5,881
2,777
5,133
3,525
[7.83]
1,026
4,107
1,751
[4.42]
41
[0.05]
1,102
[2.2]
15
[ ] * gallons/minute.
6-5
-------
D-THAMA-TASK6.1/SEDR-VTB62.1
10/12/84
Table 6-2. Louisiana AAP Solvent Extraction Material Balance
Stream
Number
1
2
3
4
5
6
7
8
9
10
11
12
[ 1 -
Explosive Inerts
(Ib/hr) Ub/hr)
890 3,562
—
890 3,562
—
0.03 3,562
<10 ppm
890
—
0.03 3,562
—
890
<1 ug/1
—
gallons /minute.
Water Acetone
(Ib/hr) (Ib/hr)
4,452
2,544
1,908
177 5,722
27 864
2,058 4,858
27 864
—
150 4,858
__ _ _
1,908 <100 mg/1
30
Total
(Ib/hr)
8,904
2,544
[5.08]
6,360
5,899
4,453
7,806
[18.13]
891
3,562
5,008
[12.7]
890
[1.2]
1,908
[3.8]
30
6-6
-------
D-THAMA-TASK6.I/SEDR-VTB63.1
10/12/84
Table 6-3. Savannah AD Activity Solvent Extraction Material Balance
Stream Explosive
Number (Ib/hr)
1 111
2
3 111
4
5 — —
6 111
7
8 <10 mg/kg
9
10 111
11 <1 pg/1
12
Inerts Water Acetone
(Ib/hr) (Ib/hr) (Ib/hr)
2,112 556/2,223*
-397/1,270*
2,112 953
60 1 , 940
2,112 16 512
997 1,428
16 512
~2,112
44 1,428
—
556/953* <100 mg/1
10
Total
(Ib/hr)
2,779/4,446*
-397/1,270
[0.8/2.5]
3,176
2,000
2,640
2,536
[5.7]
528
2,112
1,472
[3.7]
111
[0.15]
55.6/953*
[1.1/1.9]
10
* * (upper lagoon/lower lagoon)
[ ] » gallons/minute.
6-7
-------
D-THAMA-TASK6.1/SEDR-REF.1
07/16/84
REFERENCES
Francis, A.W. 1963. Liquid-Liquid Equilibriums. Interscience
Publishers, New York, N.Y.
Smith, J.M. and B.C. Van Ness. 1975. Introduction to Chemical
Engineering Thermodynamics. McGraw-Hill Book Co., New York, N.Y.
Treybal, R.E. 1963. Liquid Extraction. McGraw-Hill Book Co.,
New York, N.Y.
Treybal, R.E. 1980. Mass Transfer Operations. McGraw-Hill Book Co.,
New York, N.Y.
-------
APPENDIX A
ANALYTICAL METHODS
-------
D-THAMA-TASKS.1/SEDR-APP.1
07/16/84
APPENDIX A
ANALYTICAL METHODS
ANALYSIS OF EXPLOSIVES IN SEDIMENT BY HPLC/UV
Weigh 20 gm of sediment into a 50-ml centrifuge tube. Add 5 gm of
anhydrous sodium sulfate to the tube and mix (more anhydrous sodium
sulfate may be necessary if the sample has a high moisture content).
Extract the sample by shaking sequentially with four 35-ml portions of
acetone using a shaking time of 2 minutes. After each extraction,
centrifuge the sample and decant the extract through an anhydrous sodium
sulfate bed into a Kuderna-Danish (K-D) concentration apparatus equipped
with a 25-ml receiver. Concentrate the extract and solvent exchange to
2 ml of acetonitrile. Dilute the extract to 5 ml with water. Analyze
the extract by HPLC with ultraviolet absorption detection at 230 nm. In
all cases, 5-micron (25 cm jc 4.6 mm ID) Ultrasphere ODS columns were
used. A flow rate of 1 ml/minute and an injection volume of 250 ul were
standard. A representative chromatogram and the chromatographic
conditions are shown in Figure A-l.
ANALYSIS OF LIQUID PHASES BY HPLC/UV
The liquid phases from the solubility tests were diluted into water-
methanol mixtures prior to analysis. Those phases which contained high
levels of explosives were diluted first into acetone and further diluted
into water-methanol to avoid exceeding the solubility. For the
individual explosives solubility tests, the amount of methanol in the
mobile phase was adjusted to provide a retention time of 6 to 10 minutes
for the explosives. A 45-percent methanol in water isocratic mobile
phase was used for analysis of the liquid phase in the mixed explosives
solubility tests.
HPLC conditions for both the liquid and solid samples from the leach rate
and countercurrent tests are given in Figure A-l.
A-l
-------
CONDITIONS:
KEY:
250-ul injection volume
Isocratic elution: 50-percent methanol/
50-percent water
Flow rate: 1 ml/minute
Columns: Two 25-cm x 4.6-mm ID Ultrasphere ODS
5-micron columns in series
Ultravlotet detection at 230 nanometers
A. RDX
B. TNB
C. Tetryl
D. Nitrobenzene
E. TNT
F. 2,6-DNT
G. 2,4-ONT
Figure A-1
HPLC/UV CHROMATOGRAM OF
EXPLOSIVES FOR STANDARD SEDIMENT
METHOD DOCUMENTATION
SOURCE: ESE. 1984.
USATHAMA
A-2
-------
D-THAMA-TASK6.1/SEDR-APP.2
07/16/84
METHOD PRECISION AND ACCURACY
Spiking experiments were performed to generate precision and accuracy
data for the analysis of explosives in sediment. Explosives were spiked
into clean soil at several levels in the 0.2- to 20-ug/gm range.
Replicate analyses were performed using the procedure outlined in
Section 3.1. Table A-l lists the spike levels, precision, and accuracy
data obtained from these experiments. The method was not applicable to
tetryl because it decomposed in hot acetone during the K-D concentration
step.
GC/TCD ANALYSIS FOR WATER AND ACETONE CONTENT
Gas chromatography with a thermal conductivity detector (GC/TCD) was used
to analyze the liquid phases from the solubility, leach rate, and
countercurrent extraction tests for acetone and water content. The
chromatographic conditions and a representative chromatogram are shown in
Figure A-2.
w
LIQUID CONTENT OF SEDIMENTS
The sediments from the leach rate and countercurrent extraction tests
were analyzed for liquid using a procedure similar to ASTM Method D2216-
71. An aliquot of sediment (at least 15 gin) was weighed and placed in a
convection oven at 105°C for at least 12 hours. The dried sediment was
then reweighed to determine the liquid content. The liquid measured by
this method included both water and acetone. The percent moisture (or
percent water plus acetone) was calculated by dividing the weight of the
moisture by the initial weight of the undried sediment.
A-3
-------
KEY:
A. Water
B. Acetone
0
Q.
ffi
CONDITIONS:
a:
u
a
a
in
injection volume
Temperature program: 75° to 250° at 16°/minute,
hold 4 minutes
Carrier gas: helium at 40 ml/minute
Column: 20-foot x 1/8-inch SS packed with
80/100-M Porapak-Q
Injector temperature: 150°C
Detector 300°C sensitivity
Sensitivity: 4
Figure A-2
GC/TCD CHROMATOGRAM OF
WATER/ACETONE STANDARD
SOURCE: ESE, 1984.
USATHAMA
A-4
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D-THAMA-TASKS.1/SEDR-VTBA-1.1
10/12/84
Table A-l. Explosives in Sediment Method—Precision and Accuracy Data
Spike
Level
(ug/g)
RDX
0.267
0.534
1.34
26.7
TNT
0.204
0.408
1.02
20.4
TNB
0.205
0.410
1.02
20.5
DNT
0.210
0.419
1.05
21.0
Found Levels
(ug/g)
0.262, 0.266, 0.255
0.581, 0.571, 0.589
1.10, 1.06, 1.06
26.8, 27.1, 27.1
Overall
0.146, 0.170, 0.196
0.270, 0.495, 0.563
0.631, 0.699, 0.596
13.7, 16,0, H.'B
Overall
0.186, 0.153, 0.160
0.338, 0.359, 0.365
0.717, 0.703, 0.711
16.7, 17.0, 19.7
Overall
0.170, 0.170, 0.197
0.394, 0.386, 0.447
0.639, 0.577, 0.457
16.2, 19.7, 19.7
Overall
Average
Found
Level
(ug/g)
0.261
0.580
1.07
27.0
0.171
0.443
0.642
14.8
0.166
0.354
0.710
17.8
0.179
0.409
0.558
18.5
Percent
RSD
2.1
1.6
2.2
0.6
1.6
14.6
34.6
8.2
7.8
16.3
10.5
4.0
1.0
9.3
6.2
8.7
8.1
16.6
10.9
11.1
Average
Percent
Recovery
97.8
108.7
80.1
101.1
96.9
83.7
108.5
62.9
72.7
82.0
81.1
86.3
69.6
86.8
81.0
85.2 .
97.6
53.1
88.3
81.1
Source: ESE, 1984.
A-5
-------
D-THAMA-TASK6.1/SEDR-DL.1
10/10/84
DISTRIBUTION LIST
Addressee # Copies
Defense Technical Information Center 12
Cameron Station
Alexandria, Virginia 22314
Defense Logistics Studies Information Exchange 2
U.S. Army Logistics Management Center
Fort Lee, Virginia 23801
Commander 2
U.S. Army Toxic and Hazardous Materials Agency
ATTN: AMXTH-ES
Aberdeen Proving Ground, Maryland 21010-5401
Commander 2
U.S. Army Toxic and Hazardous Materials Agency
ATTN: AMXTH-TE
Aberdeen Proving Ground, Maryland 21010-5401
18
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