EPA-600/2-74-009b
foarch 1975
Environmental Protection Technology Series
State-of-The-Art For
The Inorganic Chemicals Industry:
Commercial Explosives
Office of Research and Development
U.S. Environmental Protection Agency
Washington, D.C, 20460
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development,
Environmental Protection Agency, have been grounod into five
series. These five broad categorie.s were established to
facilitate further development and application of environmental
technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface
in related fields. The five series are:
1. Environmental Health Effects Research
2. Environmental Protection-Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
This report has been assigned to the ENVIRONMENTAL PROTECTION
TECHNOLOGY series. This series describes research performed
to develop and demonstrate instrumentation, equipment and
methodology to repair or prevent environmental degradation
from point and non-point sources of pollution. This work
provides the new or improved technology required for the
control and treatment of pollution sources to meet environmental
quality standards.
This report has been reviewed by the Office of Research and
Development. Approval does not signify that the contents
necessarily reflect the views and policies of the Environmental
Protection Agency, nor does mention of trade names or commercial
products constitute endorsement or recommendation for use.
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ABSTRACT
A literature and field study of the commercial explosives in-
dustry reveals that on the basis of products manufactured, plant size,
and the nature of the wastewater, the industry may be divided into
three segments. One, complex facilities, are large plants manufac-
turing a variety of explosives and intermediate products. The
second category is small specialized formulation plants, typically
limited to blending explosives formulations for use in nearby mining
activities. The final category is- specialty product facilities,
devoted to manufacture of select ingredients such as lead azide and
other explosives initiators, blasting caps, electric matches and
similar appurtenance items.
The explosives industry discharges large volumes of wastewater,
typically high in BOD, nitrogen, and solids, frequently at extreme
pH, and containing trace to high quantities of dissolved and parti-
culate explosives products. Although pollution abatement technology
has not been widely implemented within the explosives industry, there
is potential for significant abatement of pollutant discharge by good
housekeeping practice, application of proven treatment technology and
under certain conditions total wastewater containment.
lit
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CONTENTS
Section Page
I. Conclusions 1
II. Recommendations 3
III. Introduction 5
IV. Scope of Study 6
V. Description of Industry 7
VI. Explosives Production 22
VII. Wastewater Characterization 36
VIII. Treatment Technology 61
IX. Acknowledgements 76
X. References 77
XI. Appendix 80
iv
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FIGURES
Page
1. Annual Consumption of Commercial Explosives 9
2. Ammonium Nitrate-Based Explosives Consumption 16
3. Annual Production of Water Gel and Slurry Explosives 18
4. Production of Black Powder and Liquid Oxygen Explosives 21
5. Ammonia Production Diagram 23
6. Nitric Acid Plant 25
7. Nitric Acid Concentration Plant 26
8. Nitroglycerin Production Schematic 28
9. Smokeless Powder Process Flow Chart 31
10. PETN Production and Acetone Recovery < 34
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TABLES
1. Commercial Explosives and Blasting Agents Sold for
Consumption in the United States 10
2. Major Commercial Explosives 12
3. Percentage Distribution of Commercial Explosives Use 13
4. Common Ingredients of Dynamites 15
5. Typical Ingredients of Water Gels and Slurries 19
6. Typical Ingredients Involved in the Manufacture of
Smokeless Powder 19
7. Typical Composition of Dynamite 30
8. Ingredients of ANFO Explosives 33
9. Complex Plants: Water Use and Wastewater Volumes 38
10. On-Site Plants: Water Use and Wastewater Volumes 39
11. Distribution of Water Use in the Explosives Industry 40
12. Specialty and Intermediate Product Water and
Wastewater Volumes 42
13. Raw Wastewater Concentrations for Complex and On-Site
Facilities 44
14. Daily Pollutant Discharges for Complex and On-Site
Facilities 46
15. Production-Based Pollutant Discharge for Complex and
On-Site Facilities 48
16. Wastewater Concentrations for Specialty and Intermediate
Products 51
vi
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TABLES (Continued)
17- Daily Pollutant Discharges for Specialty and Inter-
mediate Products 54
18. Production-Based Pollutant Discharge for Specialty and
Intermediate Products 57
19. Major Pollutants of the Commercial Explosives Industry 62
20. Treatment Plant Operation and Average Waste Concentrations 67
21. Nitrate Treatment Methods 70
vii
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I. CONCLUSIONS
On the basis of products manufactured, plant size and the nature of
thewastewater, the commercial explosives industry may be categorized
into three divisions. One, the complex facilities, are large plants
manufacturing a variety of explosives intermediates and explosives pro-
ducts. These may include nitric acid, ammonium nitrate, nitroglycerin,
dynamites, water gels, ammonium nitrate-fuel oil mixtures (ANFO) and
many others. The second category is small plants located on or near
mining fields, which blend explosives for nearby use. Typical explo-
sives products are ANFO and water gels, with intermediates received in
bulk and explosives being formulated to customer specification. The
final category is specialty product plants, involved in the manufacture
of select ingredients such as lead azide and other initiation explosives,
blasting caps, electric matches and similar appurtenance items. Some
complex facilities incorporate specialty product lines.
The explosives industry generates large volumes of both cooling and
process effluents. Average water use in the industry is 0.88 MGD for
complex facilities and 0.008 MGD for the on-site plants. Process and
cleanup water represents 22-33 percent and cooling water 19-56 percent
of this flow. The industry-wide average water use in 10,973 gallons
per ton of product.
Wastewaters of the explosives industry are typically high in BOD,
oil and grease, ammonia and nitrate nitrogen, and solids. Particularly
contributing to the dissolved solids is the high sulfate content of the
wastewater, resulting from the use of nitric plus sulfuric acid in
various explosives nitration reactions. Average discharge in Ibs/ton
product for complex and on-site facilities respectively are, for BOD
21.6 and 0.2, total solids 100.2 and 11.2, NH3 -N 4.9 and 0.07 and
N03 -N 8.7 and 0.04.
With certain notable exceptions, pollutant abatement procedures
have not been implemented in the commercial explosives industry. Oil
skimmers and settling ponds or sumps are standard practice, but due to
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poor design or maintenance are not particularly effective for oil and
suspended solids control. Beyond these measures, pollution abatement
activities are limited to a relatively few plants which have implemented
improved housekeeping methods, or employ evaporative ponds and land dis-
posal schemes. However, much of the technology applicable for control
of pollutants associated with the explosives industry has been proven
in pilot or full-scale operation, and there is significant potential
for pollution abatement within the industry.
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II. RECOMMENDATIONS
The volume and concentration of wastewaters of the explosives in-
dustry can be significantly reduced by close process control, improved
housekeeping practice, and separation of contaminated and clean process
flows. Dry clean-up procedures, as currently practiced in some segments
of the industry, have the potential to reduce pollutant discharges, with
the possible additional benefits of product recovery and reduction in
water use. Such procedures should be practiced on a routine basis with-
in the industry , where feasible.
The wastewaters of the industry exhibit pH ranging from extremely
acidic to highly alkaline. Neutralization is a direct and easily applied
control procedure, which should be implemented within the industry. In
addition, it appears that alkaline washwater, used to neutralize residual
acidity in nitroglycerin manufacture, could be recycled, thereby reduc-
ing water use and avoiding generation of a wastewater of high pH, solids and
nitroglycerin content. The technical feasibility of recycle of this
process flow should be assessed and recycle implemented if feasible.
Control of BOD and ammonia through biological treatment processes
appears to be feasible, based upon limited experience within the ex-
plosives industry. There are other alternatives in use, including land
irrigation and evaporative ponds. In instances where these latter two
techniques lack feasibility, biological treatment, either by activated
sludge or lagoons, should be considered as a possible control technique.
The need for nitrate pollution abatement within the explosives
industry is obvious. Based upon results of Army studies on nitrate
treatment in wastes of a nature similar to the explosives effluents,
biodenitrification, ion exchange and reverse osmosis all have technical
feasibility. From the point of both treatment efficiency and product
recovery, ion exchange, as practiced in one instance by a. fertilizer
manufacturer (18) appears appropriate for serious consideration, due
to the potential to recover ammonium nitrate upon regeneration of the
exhausted resin. Ammonium nitrate is a raw material of the explosives
industry, and treatment cost may be significantly offset through
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by-product recovery.
It is probable that sulfate control will eventually be required of
the explosives industry. Current technology alternatives for sulfate
control are not particularly attractive on any basis, including cost,
product recovery or treatment efficiency. However, there are technically
feasible methods proven, at least at the pilot scale, and the industry
should begin to assess and demonstrate the application of these techno-
logies on sulfate abatement for their wastes.
Improved design and maintenance of oil skimmers and suspended solids
settling basins has been shown to result in appreciable reduction in
discharge of these pollutants. The industry should apply accepted
design and maintenance standards in their use of these control facili-
ties.
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III. INTRODUCTION
The manufacture of explosives for commercial and military uses is a
major industry with many different types of products, and a spectrum in
character and concentration of product-related wastewaters. Annually,
over 2.5 billion tons of commercial explosives alone are produced. These
are primarily nitrogen-based compounds, predominately organic in nature.
Intermediate and adjunct products are often associated with the specific
manufacture of explosives. Typical intermediate products include
ammonia, ammonium nitrate, and nitric and sulfuric acids. Adjunct pro-
ducts include electric matches, detonating cords, blasting caps and
other explosive initiating devices.
The nature of the commercial explosives industry has changed rapidly
since the 1950"s. Many products have been phased out or significantly
reduced in use, due to the development of more effective and reliable
explosives, and to changes in the purpose of the explosives used.
Wastewaters of the explosives industry are of concern both due to
their pollutional nature, and for certain wastes due to their hazardous
character. For example, wastewaters from nitroglycerin manufacture are
often saturated with soluble nitroglycerin, which may become concen-
trated and represent a potential explosive hazard. There is very limited
information in the published literature pertaining to the wastewaters of
explosives manufacture, or to pollution abatement technology applicable
to control pollutant discharge from the industry.
Thus, a program of wastewater characterization and treatment tech-
nology assessment for the explosives industry is required. Due to the
difference in products of commercial versus military application, it is
appropriate to consider them separately. This study focuses upon com-
mercial explosives manufacture.
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IV. SCOPE OF STUDY
This study represents a preliminary assessment of the products and
pollution potential of commercial explosives manufacture, the extent of
pollution control utilized by that industry, and the data base available
within the industry to characterized its wastewaters and effectiveness
of pollution control. Primary sources of information included the pub-
lished literature, discharge permit applications submitted to the EPA
by the. subject industry at the time of this study, and plant visits to
selected manufacturing sites,
The plant visits included discussions with plant operating person-
nel, inspection of the manufacturing and treatment facilities, and review
of such data on wastewater character and pollution abatement as were
available from the plant. No independent sampling or analyses were
undertaken during the study, and data presented within this report were
derived only from the previously described sources. Due to the limited
scope of the study, relatively few plants could be visited. Selection
of plants was based upon an attempt to visit at least one plant manu-
facturing each explosives product, and two or more plants producing
major products such as dynamites. In total eleven plants, representing
40 process lines for intermediate and final explosives products, were
visited,
6
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V. DESCRIPTION OF INDUSTRY
The chemical explosive is a material which, under the influence of
thermal or mechanical shock, decomposes rapidly and spontaneously with
the evolution of large quantities of heat and gas. The hot gases cause
extremely high pressure if the explosion is initiated in a confined
space. The usefulness of a particular explosive is determined to a
large extent by its brisance or shattering action, and its sensitivity
to explosion initiation upon impact (1). In addition, it is important
that explosives for use in subsurface mines, particularly coal mines,
be of such a type that they evolve no toxic gases upon explosion, and
produce a minimum of flame. This latter requirement is necessary in
order that the explosion not ignite mixtures of air and coal dust within
the mines.
Explosives for mine use are tested, and their properties specified,
by the Bureau of Mines of the U.S. Department of the Interior (2).
Acceptable explosives for mine use are classified as "permissibles."
Permissibles differ from other explosives, particularly black powder,
most markedly in the fact that they produce a flame of small size and
extremely short duration. Permissible explosives normally contain
coolants to regulate the temperature of their flames, and hence reduce
the possibility of their ignition of combustible mixtures. Permissible
explosives include ammonium nitrate explosives, hydrated explosives,
organic nitrate explosives and certain nitroglycerin-based explosives
which contain an excess of free water (1).
For purposes of classification, it is convenient to place commercial
explosives in two categories in accordance with their explosive behavior;
high and low explosives. Of the high explosives, initiating (detonating)
or primary high explosives are quite sensitive materials, which can be
made to explode by the application of fire or by means of a slight impact,
They are dangerous to handle, and are used in comparatively small quan-
tities to initiate the explosion of larger quantities of less sensitive
explosives. Initiating explosives are generally used in primers, detona-
tors and percussion caps. They are typically mercury or lead compounds
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such as mercury fulminate and lead azide, styphnate or diazodinitrophenol.
Secondary high explosives are materials which are relatively insen-
sitive to both mechanical shock and flame, but which explode with great
violence when set off by an explosive shock from a detonator. Decompo-
sition proceeds by means of a detonation, which is a rapid chemical
chain reaction type destruction progressing directly through the mass of
the secondary explosive. It is this high rate of energy release that
provides the brisance property.
Low explosives differ in their mode of decomposition from high
explosives, in that they only burn. Burning is a phenomenon that pro-
ceeds not through the body of the explosive, but in layers parallel to
the surface. It is quite slow in its action, often proceeding thousands
of times more slowly than the decomposition of the high explosive. The
action of the low explosive is therefore less shattering.
The production of industrial explosives has shown a steady increase
for many years, with an average annual increase of 6.9 percent for the
ten-year period 1962-1972 (Figure 1). The U.S. Bureau of Mines maintains
statistics on the use of explosives, and 1972 is the latest year for
which those statistics are available (3). These statistics are reported
in terms of high explosives (permissible and other); blasting agents
which include ammonium nitrate-based explosives and various water gel
and slurry formulations consisting of mixtures of an oxidizer and a fuel
and sensitizer in an aqueous medium thickened with a gum and gelled with
a cross-linking agent; and black blasting powder which includes all ex-
plosives having sodium or potassium nitrate plus sulfur and charcoal as
constituents. Table 1 summarizes the most recent Bureau of Mines data
on explosives production. Of the permissible explosives, ammonium
nitrate compounds constitute over 70 percent of use. The high explosives
used in industry are primarily dynamites. In general, commercial explo-
sives are not applicable to military use, since they are too sensitive
to impact and shock, thus presenting serious risks in handling. Further,
they do not possess the necessary brisance required for military explo-
sives.
8
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3.0
2.5
I
ri 2.0
§
O
CO
M
CO
g
1.5
1.0
0.5
1962
1964
1966
1968
1970
1972
YEAR
FIGURE 1. ANNUAL CONSUMPTION OF COMMERCIAL EXPLOSIVES
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Table 1. Commercial Explosives and Blasting Agents Sold for Consumption in the United States
(Thousand pounds)
Class
1971
1972
Fixed high explosives:
Permissibles—- ---•
Other high explosives
Total
Blasting agents:
Cylindrically-packaged
Water gels and slurries
Other processed blasting agents and
unprocessed ammonium nitrate
Total
Black blasting powder:
Granular
Pellet
Total
Grand total
43,557
272,816
316,373
42,967
230,692
1,963,865
2,237,524
117
117
2,554,014
46,147
268,798
314,945
226,206
226,243
1,862,395
2,354,844
2,669,789
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Commercial Explosives and Use
Table 2 summarizes the major commercial explosives, including sen-
sitizers commonly added to low explosives. In addition, the final
explosive product may contain a variety of absorbents, coating agents,
fuels, oxidizers and other materials. For example, nitrocarbonitrate,
among the low explosives, typically contains ammonium nitrate, mineral
or fuel oil, DNT or TNT, plus an energizer. Typically, both high and
low explosives involve either single organic compounds, or mixtures of
organic compounds, and inorganic salts. The first group includes (1)
esters of nitric acid and polyhydric alcohols such as nitroglycerin,
nitroglycol and pentaerythritol tetranitrate, (2) carbohydrates such as
nitrocellulose and collodion cotton, (3) nitro compounds (e.g., dinitro-
and trinitrotoluene), and (4) alicyclic compounds like cyclotrimethylene
trinitroamine (4). Explosives such as nitrocellulose, TNT and penta-
erythritol tetranitrate (PETN) are predominantly produced for military
uses, although they do have some limited application as supplemental
ingredients in commercial explosives.
Table 3 indicates that over 97 percent of all commercial explosives
use is related to mining and construction activities. Mining alone
typically accounts for up to 80 percent of commercial explosives con-
sumption, with coal mining comprising half or more of the mining use.
Explosives usage in coal mining has increased rapidly in recent years
owing to the marked expansion in strip mining, where thicker over-
burdens are encountered each year (5). This gain in strip mining use
has more than compensated for decreased explosives consumption in
underground coal mining in which the use of continuous mining machines,
with virtually no explosives requirements, is growing at a fast pace (6),
The discovery of nitroglycerin and nitrocellulose shortly before
1850 and the invention of dynamites and the mercury fulminate blasting
cap soon thereafter initiated an era of high explosives use. Nitro-
glycerin is obtained by nitrating glycerin with a mixture of nitric and
sulfuric acids. Nitroglycerin is a liquid similar in appearance to the
original glycerin. It is extremely sensitive to impact, and freezes at
56 F. To make nitroglycerin easier and safer to handle, it is usually
11
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Table 2. Major Commercial Explosives
A. Primary High Explosives
Blasting Caps
Detonating Cords
Electric Matches
Lead Azide
Mercury Fulminate
Safety Fuses
B. Secondary High Explosives
Dynamites
Nitroglycerin
Pentaerythritol Tetranitrate (PETN)
C. Low Explosives
Ammonium Nitrate (Prilled or Grained)
Ammonium Nitrate-Fuel Oil Mixtures (ANFO)
Black Powder
Nitrocarbonitrates
Smokeless Powder
Water Gels and Slurries
D. Low Explosives Sensitizers
Amine Nitrates
Dinitrotoluene (DNT)
Trinitrotoluene (TNT)
12
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Table 3. Percentage Distribution of Commercial Explosives Use (3)
Year
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
Coal
Mining
34.7
33.0
31.6
31.4
34.7
35.1
36.8
40.2
42.0
45.4
Quarrying and
Non-metal Mining
22.0
21.7
19.7
20.1
21.5
20.4
19.7
19.0
19.2
18.5
Railroad and
Other Construction
21.0
19.9
21.8
22.2
21.7
21.1
20.0
18.7
18.7
17.5
Metal
Mining
17.4
19.1
18.9
17.9
17.2
20.7
21.1
20.0
17.9
16.1
S e i smogr aphic
Exploration
4.2
5.5
7.4
7.7
4.5
2.1
1.8
1.1
0.7
0.7
Other
Purposes
0.7
0.8
0.6
0.7
0.4
0.5
0.6
1.0
1.5
1.8
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manufactured into dynamite.
Modern dynamites generally use wood flour, ammonium nitrate or
sodium nitrate as the agent employed to absorb the nitroglycerin. Many
other materials may also be added, including oxidizers, and agents such
as ethylene glycol dinitrate to lower the freezing point of the nitro-
glycerin. Table 4 lists typical ingredients of dynamites. The final
ingredients and their proportions depend upon the specifications for its
use. Nitroglycerin content of the dynamite may range from as little as
15 percent, up to 75 percent and still .retain its solid form. Nitro-
cellulose is gelatinized by nitroglycerin, and the resulting firm jelly
is an exceptionally powerful high explosive commonly known as gelatin
dynamite. Much of the dynamite use is in quarrying and construction
work. This use has declined slightly in recent years, as ammonium
nitrate and water gel explosives have become more widely used.
Pentaerythritol tetranitrate is one of the most brisant and sensi-
tive high explosives. PETN is synthesized by the nitration if penta-
erythritol with concentrated nitric acid. For use as a booster explosive,
a bursting charge or a plastic demolition explosive, it is frequently
desensitized by admixture with TNT or by addition of wax. Its use is
extremely limited in industrial applications, typically to manufacture
of detonating cord.
Ammonium nitrate-based explosives have almost completely replaced
the majority of other commercial explosives in the surface mining,
quarrying and construction industries (1). Figure 2 shows that in 1972,
ammonium nitrate explosives represented almost 80 percent of the total
commercial explosives use, and that this was up from 61 percent in 1962.
Thus, much of the increase in use of explosives in recent years (Figure 1)
is directly attributable to increased utilization of ammonium nitrate
compounds.
Ammonium nitrate explosives may be manufactured in several formula-
tions. The U.S. Bureau of Mines distinguishes between unprocessed and
processed ammonium nitrate explosives as follows. The unprocessed
ammonium nitrate product is about 99.5 percent ammonium nitrate, with a
small amount of surface active agent added to prevent caking. The
14
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Table 4. Common Ingredients of Dynamites
Nitroglycerin
Ammonium Nitrate
Sodium Nitrate
Sodium Chloride
Sulfur
Nitrocellulose
Phenolic Resin Beads
Bagasse
Sawdust and Wood Flour
Coal
Corn Meal and Corn Starch
Trace Inorganic Salts
Grain and Seed Hulls and Flours
15
-------
100
w
CO
CO
f-J
H
CO
CO
13
S 20 -
1962
FIGURE 2.
1964
1966
1968
1970
YEAR
AMMONIUM NITRATE-BASED EXPLOSIVES CONSUMPTION AS PERCENTAGE OF TOTAL ANNUAL
COMMERCIAL EXPLOSIVES CONSUMPTION.
1972
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unprocessed ammonium nitrate is usually prilled or grained, and is mjLxed
with a carbon fuel (typically fuel oil), often on-site, before use as a
blasting agent (3). Processed ammonium nitrate is ammonium nitrate that
is premixed with a carbon fuel usually 6 percent fuel oil plus 94 percent
ammonium nitrate (the product being called ANFO), and is supplied in bulk
or in bags or cylinders. The bags or cylinders of ANFO are loaded
directly into the blast hole.
ANFO was introduced as an explosive in the mid-1950's, and by 1972
constituted 79.7 percent of the total commercial explosives use. ANFO
frequently contains powdered aluminum at up to 5 percent by weight, plus
the ammonium nitrate, carbon fuel (oil), and small amounts of stabilizers
and inhibitors. Larger plants which produce ammonium nitrate-based ex-
plosives frequently include an ammonia production facility. Smaller ANFO
plants, located near mining fields, are typically blending facilities
only, receiving unprocessed ammonium nitrate and fuel oil in bulk ship-
ments. These constituents are blended to customer specification, and
the product ANFO transported by truck to the mine fields.
Water gels and slurries were introduced as industrial explosives in
1960, and have rapidly expanded in use since (Figure 3). Water gels and
slurries can have an almost infinite number of formulations, but are
basically mixtures of an oxidizer and a fuel and sensitizer in an aqueous
media thickened with a gum and gelled with a cross-linking agent. The
water content ranges from 5 to 40 percent, but averages 15 percent (3).
In most slurries and water gels, ammonium nitrate is the primary oxidizer,
although sodium nitrate is often added when more available oxygen and a
higher density is required. The U.S. Bureau of Mines reports that a
typical blasting agent in this class contains 15 percent water, 60 per-
cent ammonium nitrate, 10 percent sodium nitrate and the balance in other
materials (3). Table 5 presents common ingredients of water gels and
slurries.
Nitrocarbonitrate (NGN) blasting agents, first introduced in 1935,
have very limited use, primarily for seismic exploration. NGN is similar
in constituents to ANFO, and may contain in addition mineral oil, sodium
nitrate and dinitro or trinitrotoluene, plus various proprietary ingre-
17
-------
CO
§
§
8
e
O
c*
ta
220
200
180
160
140
1967
1968
1969 1970
YEAR
1971
1972
FIGURE 3. ANNUAL PRODUCTION OF WATER GEL AND SLURRY
EXPLOSIVES.
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Table 5. Typical Ingredients of Water Gels and Slurries
Ammonium Nitrate
Sodium Nitrate
Fuel Oil (opt.)
Guar Gum
Water
Aluminum Powder (opt.)
Smokeless Powder (opt.)
Nitroglycerin (opt.)
Trinitrotoluene (opt.)
Proprietary Agents (opt.)
Carbon Fuel (opt.)
Gelling Agents
Table 6. Typical Ingredients Involved in the Manufacture of Smokeless
Powder
Nitrocellulose
Dipheny lamine
Ethyl Acetate
Dibutyl Phthalate
Nitroglycerin
Animal Colloids
Alcohol
Diethyldiphenyl Urea
Potassium Nitrate
Graphite
19
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dients in trace amounts.
Smokeless powder, first manufactured in 1867, is colloided nitro-
cellulose containing about 1 percent diphenylamine to improve its
storage life and a small amount of plasticizer such as dibutyl phthalate
(1)0 Smokeless powder has primary use as a propellant in ammunition,
although it is added in small quantities to other explosives such as
water gels and slurries and (as nitrocellulose) to some dynamites. In
the manufacture of smokeless powder, cotton or specially prepared wood
pulp is nitrated with concentrated nitric acid. After purification the
nitrated cellulose is disintegrated, then "colloidized" by mixing with
alcohol, ether, diphenylamine or other modifying agents. Colloiding
the nitrocellulose transforms it into a dense uniform mass with reduced
surface, providing greater rapidity of explosion (1). Table 6 lists
typical ingredients involved in smokeless powder manufacture.
Two explosives which previous to 1970 held significant positions
in commercial application have,for all practical purposes, ceased to be
used. These explosives are black blasting powder and liquid oxygen
explosives. Liquid oxygen explosive consists of bagged carbon black
soaked in liquid oxygen (6). Used solely for strip coal mining, and
only in Illinois, its use increased rapidly from 1963 to 1966, but this
explosive had ceased to be used by 1968 (Figure 4), and is no longer
produced. Liquid oxygen explosives have now been replaced by ammonium
nitrate formulations, including water gels and slurries.
Black blasting powder use has also declined rapidly in recent years,
and its direct commercial application ceased during 1971 (5). Its pri-
mary use today is limited to safety fuses. Other applications have been
surplanted by ANFO and water gels and slurries.
20
-------
M
d
o
S3
•8
8
CO
M
8
1-4
200
10.0
8.0
6.0
4.0
2.0
1.0
0.8
0.6
0.4
0.2
0.1
BLACK POWDER
LIQUID OXYGEN
1962
1964
1966
1968
1970
1972
YEAR
FIGURE 4. PRODUCTION OF BLACK POWDER AND LIQUID OXYGEN
EXPLOSIVES.
21
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VI. EXPLOSIVES PRODUCTION TECHNOLOGY
In addition to the final explosives products, many of the larger
explosives plants manufacture selected intermediates or ingredients of
explosives formulations. On-site production of ammonia, weak and strong
nitric acid, and ammoniunnitrate is particularly common, although some
plants purchase these materials in bulk. Although the manufacture of
ammonia, nitric acid or ammonium nitrate is not unique to the explosives
industry, their production does contribute to waste loads where these
processes are a part of the plant complex. In order to understand the
nature and sources of these wastes, the production technology for ammonia,
nitric acid and ammonium nitrate, as well as the major explosives pro-
ducts among those previously listed in Table 2, will be described.
A. Ammonia. The manufacture of ammonia requires natural gas, air
and steam. Figure 5 is a schematic representation of the process. In
the first step, the three reactants are catalytically reformed to yield
nitrogen, hydrogen, carbon monoxide and carbon dioxide gases. The carbon
monoxide and carbon dioxide represent impurities, which are scrubbed from
the effluent gas of the reforming process, typically after oxidation of
carbon monoxide to carbon dioxide. The purified nitrogen plus hydrogen
gas is then catalytically reacted in a synthesis process to yield ammonia,
which is taken to storage as either a gas or aqueous solution. Cooling
is required at all steps in the ammonia manufacture, and condensate is
normally discharged as a waste flow.
B. Nitric Acid - Manufacture and Recovery. Many explosives plants
manufacture weak and strong nitric acid for their own uses, and a few
explosives plants incorporate spent nitric acid recovery processes as
well. The principle uses of nitric acid in explosives manufacture are
for production of nitroglycerin, ammonium nitrate, nitromannite (a com-
ponent of blasting caps) and pentaerythritol tetranitrate(PETN). Weak
(55-60%) nitric acid is used to produce ammonium nitrate as well as
concentrated (98%) nitric acid, which is used for the other explosives
products listed above.
Weak nitric acid is produced by catalytic oxidation of ammonia with
22
-------
COOLING TOWER
t t
COOLING WATER
(ALL OPERATIONS)
SYNTHESIS SECTION
3 H CATALYST. 2
PURIFICATION SECTION
(REMOVAL OF CO AND C02)
REFORMING SECTION
CATALYST
NAT. GAS + AIR
N«+ 3 1L+ CO
OS
AMMONIA STORAGE
H2°"
AQUA AMMONIA
AQUA
NIL
FIGURE 5. AMMONIA PRODUCTION DIAGRAM
13
-------
atmospheric oxygen to produce nitrous oxides (NO and N02). In the process
(see Figure 6), anhydrous ammonia is vaporized, mixed with preheated air,
and passed through a platinum gauge catalyst. The ammonia is thereby
oxidized to oxides of nitrogen. After cooling the gases pass through
a water absorption column where weak nitric acid is formed, with
venting of N7 and NO to the atmosphere. The acid is then either used
• X>
for ammonium nitrate production, or further concentrated to yield strong
nitric acid.
Since most explosives nitration reactions require concentrated nitric
acid, the weak acid from the platinum catalysis process must be -concen-
trated to 95-98%. In the process, weak nitric acid is mixed with concen-
trated sulfuric acid (oleum), heated, and pumped through a dehydration
tower under vacuum to pull off nitric acid, water vapors and nitrogen
oxides. The sulfuric acid effluent from the tower flows through a cas-
cading series of steam heated boiler tubes, to drive off residual con-
taminants, which are returned to the dehydration tower. The nitric acid
vapor from the dehydration tower is condensed to yield concentrated acid,
while the nitrogen oxides are taken to the weak nitric acid production
facility. The spent sulfuric acid is either discharged, reprocessed on-
site, or sold for reprocessing and recovery. Figure 7 is a schematic of
the nitric acid concentration process.
Spent nitrating acid from processes such as nitroglycerin and PETN
manufacture are frequently processed by the explosives industry to
recover nitric acid. The recovery process is incorporated in the nitric
acid concentration line, with spent nitrating acids being bled into the
dehydration tower along with the weak nitric plus concentrated sulfuric
acid mixture.
C. Ammonium Nitrate. Ammonium nitrate is used primarily in gran-
ular or "prill" form in explosives. Anhydrous ammonia and weak nitric
acid are reacted at 300°F to yield concentrated (9970) ammonia nitrate.
This solution is discharged to water-colled stainless steel crystallizer
bowls or belts, where it is cooled to form a crystalline ammonium nitrate
cake. The cake is ground or crushed and screened. Various additives,
including wax to coat the prill, and fullers' earth for moisture control
24
-------
CONDENSOR
NO
x
HEAT
EXCHANGER
NO
J
H00
OXIDIZER
"S f
COMPRESSOR
T
AIR
NO
WO,
ABSORPTION
TOWER
n
UNO,
FIGURE 6. NITRIC ACID PLANT
25
-------
ACID STORAGE
PO
h*- STEAM
PRE-
HEATER
DEHYDRATING
TOWER
*
STEAM
BOILERS
VAPOR
AND NO
VACUUM
NO
SULFURIC
ACID
CONDENSOR
NO
VACUUM
97% HNO,
BLEACHER
i
ABSORPTION
TOWER
T
55% HNO,
FIGURE 7o NITRIC ACID CONCENTRATOR PLANT
-------
are blended in, and the product stored.
D. Nitroglycerin. Nitroglycerin (NG) is synthesized in a batch
reactor, by controlled reaction between a concentrated sulfuric acid -
concentrated nitric acid solution and a mixture of ethylene glycol and
glycerin (Figure 8)0 The reactor contains cooling coils through which
circulate a cooled brine solution. The reactor is initially charged
with the nitrating acid mixture. The glycerin-glycol solution is then
added, at a rate that maintains a temperature of 40 F in the reactor.
This rate is dependent upon ambient temperature and the cooling brine
temperature, which rises during the day. Consequently, reaction time
varies as the cooling capacity varies. Lower temperatures are also
dangerous, as solid nitroglycerin is very shock-sensitive and could be
detonated by the reactor mixing system.
The reacted product (a mixture of NG, ethylene glycol dinitrate,
water and spent sulfuric and nitric acid) passes into a gravity separator
tank where the spent acid is drawn from the bottom of the mixture and
either discharged or sent to acid recovery. The riitroglycerin is then
dropped into a prewash tank and mixed with water. The resulting "sour
water" is removed from the top and goes to a catch tank. Occasionally,
sodium fluorosilicate is added at this point to break the water - NG
emulsion. The NG is drained from the catch tank and sent to two neutra-
lizer tanks. In the neutralizer tanks the NG is emulsified with a soda
(Na»CO_) water solution. After a final wash with water the NG is taken
by rubber lined channels or wheeled carts to the dynamite formulation
building. Ethyl acetate, a desensitizing-carrier solvent is sometimes
mixed with the NG, when it is to be stored for a period of time.
E. Dynamites. There are many different formulations of dynamites,
although the basic ingredients are nitroglycerin and ammonium nitrate.
Ammonium nitrate is first mixed in batch with various minor ingredients.
The most common of these were listed in Table 4. Other minor ingredients
may also be added, but are considered proprietary by the manufacturers
of dynamites. This mixture forms a "dope", to which the nitroglycerin
is added. The proportions of nitroglycerin and ammonium nitrate, and
the specific minor ingredients and their proportions, determines the
27
-------
NITRATOR
NG-ACID
MIXTURE
GRAVITY
SEPARATOR
SPENT
ACIDS
GLYCERIN PLUS
ETHYLENE GLYCOL
NITRIC PLUS
SULFURIC ACIDS
SODIUM
CARBONATE
SOLUTION
I
N(
•q
HWASH
TANK
(WATER)
NG
NEUTRALIZER
TANK
1 1
NG
WASTE WATER
N
\
CATCH
TRAP
h
H20
FINAL
WASH
NG
FIGURE 8. NITROGLYCERIN PRODUCTION SCHEMATIC
28
-------
particular properties of the dynamite. Many dynamites are formulated to
customer specification. After formulation, the dynamite is transported
to a cartridging house for packaging into waxed cardboard or plastic
tubes, and then shipped or stored in magazines. A typical dynamite for-
mulation is shown in Table 7.
F. Smokeless Powder. This product, used as a cartridged propellant,
incorporates as its primary ingredients nitroglycerin and nitrocellulose.
Other ingredients are listed in Table 6. Two smokeless powder lines were
visited during this study. They were similar in their operations, and
the following description represents an overview of the two processes.
In both cases, nitrocellulose is obtained from an outside supplier.
Figure 9 presents an overall schematic of the smokeless powder manu-
facturing process. Supplemental operations include NG manufacture and
nitrocellulose recovery. For recovery, scrap powder is stored as a
water slurry. Overflow from storage, when capacity is exceeded, goes to
waste. Recovery involves extraction of nitrocellulose from the scrap
powder with benzene plus ethyl acetate solvent. This solubilizes con-
taminants, which are evaporated to precipitate, and incinerated. Residual
water is decanted as waste. The solvent evaporant is recondensed in a
water-cooled unit. The purified nitrocellulose is mixed with water, and
the slurry returned to the manufacturing line.
In the specific operations of base grain preparation and size
separation, the extracted powder, as a water slurry, is passed over a
vibrating table to remove grit, and screened to remove oversize parti-
cles. Both processes use water. Centrifugation follows, with the excess
water becoming a part of the waste flow. Diphenylamine and ethyl acetate
are added, along with hot water, to form a dough-like mixture of nitro-
cellulose. This is pressed through screens and chopped, to form grains
which pass into a jacketed steam chamber for drying and shaping into
balls. The solvent is removed by evaporation, and recovered. Filtration
and screening follow. The resultant grain is taken to storage. Filter
backwash water is discharged.
G. Ammonium Nitrate - Fuel Oil (ANFO) Mixtures. ANFO is a mixture
of ammonium nitrate prills and fuel oil, to which a variety of other
29
-------
Table 7. Typical Composition of Dynamite
Component Percent, Wt,
Ammonium Nitrate 50-55
Nitroglycerin 15-18
Sodium Nitrate 0-17
Trace Ingredients 10-35
30
-------
BASE GRAIN
PREPARATION
GRAIN
COATING
I
ROLLING
i
WET BLENDING
I
DEWATERING
DRYING
SURFACE COATING
DRY SCREENING
BLENDING
SIZE
SEPARATION
NITROGLYCERIN
ADDITIVES
PACKING
FIGURE 9. SMOKELESS POWDER PROCESS FLOW CHART
31
-------
minor ingredients (Table 8) may be added. This includes, in some
instances, powered aluminum at up to 5 percent by weight. ANFO is for-
mulated as a batch or continuous dry mixing operation, and the only
wastewater source results from clean-up of spills and equipment.
Occasionally the fuel oil (#2) is dyed prior to mixing with ammonium
nitrate, to identify specific formulations. The product is bagged in
paper, plastic or burlap, depending upon the intended use.
H. Nitrocarbonitrates. These explosive products are similar in
composition and manufacture to ANFO. -In addition to or in place of fuel
oil, the product may also contain mineral oil. Aluminum powder is a
common ingredient, as well as dinitrotoluene (DNT), and routine ANFO
ingredients listed in Table 8. The formulation is a dry batch mix, with
wastewater restricted to clean-up of spills and equipment. Crude DNT is
purchased from outside suppliers.
I. Water Gels and Slurries. Water gel manufacture is a batch
process involving mixing of ammonium nitrate, sodium nitrate and other
ingredients listed in Table 5 to form a semi-solid product. Guar gum
is added to provide binding. The product may be bagged, or shipped in
bulk by truck for on-site injection. A gelling catalyst such as chro-
mate is injected when water gel is used in bulk on-site. Bagged products
do not incorporate the catalyst. Wastewater from the product originates
only from clean-up of spills, mixing equipment and bulk transport trucks.
Certain water gel formulations include proprietary supplemental compo-
nents as explosive boosters. These supplemental ingredients are
classified as proprietary by the manufacturers.
J. Pentaerythritol Tetranitrate (PETN). Figure 10 provides a
schematic of PETN production. The pentaerythritol is nitrated with
concentrated nitric acid, and PETN separated in a centrifuge. Spent
acid is recovered. The PETN cake is mixed with water, and the slurry
filtered to removal residual acid. The crystalline PETN is then dis-
solved in acetone, with sodium carbonate added to further neutralize
residual acidity. After graining with water, the slurry is again
filtered, and the granular PETN taken to storage. The acetone-water
filtrate is digested with sodium hydroxide at pH 10 and 210 F, to
32
-------
Table 8. Ingredients 01 ANFO Explosives
Ammonium Nitrate Fuel Oil
Ferrophosphate Aluminum
Calcium Silicate Coal
Atticote Mineral Oils
-------
CONG. HNO,
PENTA-
ERYTHRITOL
CONTINUOUS - pETN
NITRATOR I——pJCENTRIFUGE
ACETONE
STORAGE
STILL
BOTTOMS
H2°
SLURRY
HN03 TO
RECOVERY
ACETONE
SODIUM
CARBONATE*
CAUSTIC
PETN
DIGESTOR
FILTER
PETN
DISSOLVER
1
GRAINER
FILTER
ACETONE/WATER
ri
PETN
FIGURE 10. PETN PRODUCTION AND ACETONE RECOVERY
34
-------
destroy residual FEIN, and the acetone recovered by distillation. Still
bottoms are discharged as waste. Other wastewaters result from the first
wash of PETN after centrifugation, to remove residual acid.
35
-------
VII. WASTEWATER CHARACTERIZATION
The explosives industry, for purposes of wastewater characterization,
should be divided into three categories:
1, Complex Facilities, representing large manufacturing
complexes which both manufacture intermediates and
blend them into explosives formulations. Typically
these plants will manufacture ammonia, nitric acid,
ammonium nitrate and nitroglycerin plus other inter-
mediates, and formulate dynamites, smokeless powder,
ANFO, water gels and other similar explosives products.
Individual complex facilities may purchase certain
intermediates, and may not formulate all explosives.
2. On-Site or Near-Site Mixing Plants, which receive
explosives ingredients in bulk, and mix these in-
gredients to formulate explosives products meeting
nearby customer specifications. In select cases,
minor ingredients may be manufactured at these
plants, but bulk materials such as ammonium nitrate
are shipped in. The predominant products of on-site
plants are ANFO and water gels and slurries.
3. Specialty Plants, which manufacture only select
ingredients or explosives products, to be shipped
elsewhere for final formulation into explosives.
These select products include lead azide and other
explosives initiators, blasting caps, electric
matches and similar appurtenance items.
The majority of explosives plants fall into the first two of the
above categories, and consequently more data was available for this
study from the complex facilities and on-site plants then for the
specialty plants.
36
-------
Considering first water use and wastewater discharge volumes
associated with explosives manufacture, Tables 9 and 10 summarize such
data as was obtained from plant visits, and review of available dis-
charge permit application and plant operating records. Average water
use for the eight complex plants (Table 9) for which data was available
was 1.23 MGD, and on a production basis 18,297 gallons per ton of final
explosives product. This compares with averages (Table 10) of 0.0082
MGD and 719 gallons per ton of product for on-site facilities. Average
production for the plants of Tables 9 and 10 were 80.6 and 25.0 tons of
explosives per day, respectively. This production differential reflects
more the complexity of processing than relative plant size. The on-site
plants are normally quite small facilities, involved only with batch
blending of bulk ingredients. The complex facilities, in using the most
basic raw materials, are usually large plants with many production steps
prior to final explosive product formulation.
Wastewater discharge volumes, for complex facilities and on-site
plants respectively, were 0.91 and 0.0074 MGD, and 13,462 and 514 gal-
lons per ton of product. The average wastewater volume represents 74.2 per-
cent and 89.5 percent of total water use for complex and on-site plants.
This difference in volume results from omission of sanitary sewage flow
from the wastewater volume, and from water losses due to evaporation,
boiler make-up, and water incorporated into explosives products. Table
11, showing the distribution of water use for complex and on-site facil-
ities, indicates that sanitary plus boiler make-up water use averages
21.5 percent and 47.6 percent respectively for the two manufacturing
categories.
Inspection of the data of Tables 9 and 10 reveals that there is
wide variation in the production-based water use and wastewater dis-
charge volumes for both complex and on-site plants. Most plants provide
their own water supply from surface or ground water sources, and utilize
cooling and process water only on a once-through basis. Zimmerman (7)
has reported that the national average water use in the explosives in-
dustry is 284,000 gallons per ton of product. However, the data gener-
ated in this study does not support that claim, and yields an industry-
wide average of 10,973 gallons per ton.
37
-------
Table 9. Complex Plants: Water Use and Wastewater Volumes
Plant
CV.01
CV.02
CV.03
CV.04
CV.05
CV.06
CV.07
CV.08
AVERAGE
MGD
NA
0.38
3.30
1.55
0.65
0.36
0.18
2.17
1.23
Water Use
Gal. /Ton Prod.(1)
NA
5,279
8,878
11,081
48,148
3,600
2,880
48,222
18,297
Wastewater Discharge
MGD
0.240
0.044
2.52
1.53
0.497
0.360
0.15
1.96
0.913
Gal o /Ton Prod.(1)
3,002
617.0
6,779
10,928
36,814
3,600
2,400
43,555
13,462
CJ
09
(1)
Based on total tonnage of final products only,
-------
Table 10. On-Site Plants: Water Use and Wastewater Volumes
t*>
to
Plant
SV.01
SV.02
SV.03
SV.04
SV.05
AVERAGE
Water Use
M3D
0.0042
0.00545
0.01186
0.00070
0.00189
0.00822
Gal. /Ton Prod.
105
170
152
17
3,150
719
Wastewater Discharge
MGD
NA
0.00545
0.0230
0.000030
0.000955
0.00736
Gal. /Ton Prod.
NA
170
295
0.74
1592
514
-------
Table 11. Distribution of Water Use in the Explosives Industry, Percent
Category: Processing
Plant and Clean-up
A. Complex Plants:
DA. 01
DA. 02
DA. 03
DA. 04
DA. 05
DA. 06
AVERAGE
B. On -Site Plants:
DB.01
DB.02
DB.03
DB.04
DB.05
AVERAGE
31.1
0.7
55.8
11.0
5.5
30.4
22.4
68.0
5.5
2.5
90.0
1.6
33.5
Cooling Boiler
Water Make-up
59.8 7.9
89.0 7.1
22.1 10.3
61.1 16.8
44.5 44.5
59.9 8.3
56.1 15.8
0.0 1.8
41.3(1) 52.3
5.2(1) 12.0
0.0 2.9
47.6^ 47.6
18.8 23.3
Sanitary
Use
1.2
3.2
11.8
11.1
5.5
1.4
5.7
30.2
0.9
80.3
7.1
3.2
24.3
' 'Cooling water associated with on-site manufacture of proprietary
ingredient of explosives formulation.
-------
Limited data on flow volume for intermediate and specialty pro-
ducts was generated, and is presented in Table 12. Nitroglycerin, an
intermediate in the manufacture of dynamites, has an average wastewater
discharge volume of 751.6 gallons per ton NG. This is primarily sodium
carbonate solution and wash water used to neutralize residual acidity
after the nitration process. Other intermediates shown in Table 12
include ammonia, nitric acid and ammonium nitrate. Specialty products
include PETN, lead azide and blasting caps. Data was sufficiently
detailed for only a few plants to enable determination of discharge
volumes for manufacture of intermediate and specialty products.
The major wastewater constituents associated with explosives manu-
facture are nitrogen (ammonia, organic, urea and nitrate), solids, BOD,
oil and grease, and certain intermediate products such as ethylene gly-
col, NG, PETN and DNT. In many cases, extreme pH values are encountered,
due to highly acidic or alkaline process waste streams. Characteristic-
ally, the first wash water from NG manufacture is acidic, while
subsequent neutralizing washes with sodium carbonate solution yield
alkaline flows. High sulfate levels are also associated with NG, as
well as other nitrated products, due to the use of fuming sulfuric acid
with the nitric acid in the nitration process. Wastewater from specialty
product manufacture may contain significant levels of heavy metals, such
as lead, aluminum, copper and chromium (used as a gelling catalyst).
Manufacture of certain proprietary ingredients of explosives involve
the use of phenol, and wastewater from these processes may contain phenol
in excess of 100 mg/1. Dust control, particularly in dynamite mix
houses, usually requires exhaust systems, and particulate removal from
the exhausted air by scrubbling is frequently used. This scrubber
water constitutes a waste flow high in BOD, solids and nitrogen forms.
The manufacture of PETN has as one step dissolving the PETN in
acetone, followed by neutralization with sodium carbonate and recrystal-
lization of PETN by addition of water. The acetone-water solution is
then filtered off, and digested with sodium hydroxide at pH 10 and
210°F to destroy residual PETN. The acetone is recovered by distilla-
tion, while still bottoms are discharged. In the one plant practicing
41
-------
Table 12. Specialty and Intermediate Product Water and Wastevater
Volumes
Prrwltir* t* /PI an f*a
NITROGEN PRODUCTS^ '
NP.01
NP.02
NP.03
NP.04
AVERAGE
AMMONIA
AM.OL
AMMONIUM NITRATE
AN. 01
NITROGLYCERIN
NG.01
NG.02
NG.03
AVERAGE
PETN
PE.Ol
PE.02
LEAD AZIDE
LA.Ol
BLASTING CAPS
BC.Ol
Water Use
MGD
NA
NA
NA
NA
—
NA
NA
NA
NA
NA
—
NA
NA
0.370
0.0880
Gal /Ton
NA
NA
NA
NA
—
NA
NA
NA
NA
NA
—
NA
NA
2,312,500
2200
Wastewater Discharge
MGD
0.0720
0.1450
0.800
0.940
0.489
0.020
0.0250
0.0048
0.0200
0.0042
0.0097
0.010
0.400
0.310
NA
Gal/Ton
360.0
5184.6
1789.7
NA
2444.8
1066.7
384.6
436.4
1066.7
NA
751.6
2857.1
NA
1,937,500
NA
(I)
Ammonia plus nitric acid plus ammonium nitrate.
42
-------
acetone recovery, for which sufficient information was available to
define the waste character of the still bottoms, the waste had the
following characteristics;
Flow 6000 gpd
pH 11.0
Temperature, °F 180
BOD5, mg/i 15,510
COD, ng/1 19,620
Kjeldahl-N, mg/1 8,43
Nitrate-N, mg/i 172.0
The recovery process yielded 2,500 gallons of acetone per day, with a
waste discharge of 310 Ibu. of BOD. and 3.44 Ibs. of nltrate-i per 1000
gallons of acetone recovered.
Tables 13-15 present combined wastewater discharge data for complex
facilities and on-site plants. There is a great deal of variation In
the waste nature of individual plants within each group, and it is prob-
able that the data for the on-site plants is too limited to provide
reliable averages. A comparison of the averages for complex and on-site
plants shown in Table 13 reveals a more heavily polluted wastewater
associated with the complex facilities. The pH range was 1.9-10.3, as
compared with a pH range of 6.2-7.9 for the smaller (on-slte) plants.
Average pollutant concentration, for each parameter except suspended
solids and nitrate nitrogen was at least twice as high for complex
facilities. The parameters of exception, suspended solids and nitrate-Ny
reflect poorer solids removal and proportionally greater clean-up water
use at the smaller plants.
In complex facilities, more then half of the total water use is for
cooling purposes (Table 11), and this water is often combined with and
dilutes the process waste flows. This likely accounts for some of the
variability in concentration among plants. Although no data was avail-
able on oil and grease levels for on-slte plants (Table 13), it would
be expected, particularly In these plants formulating ANPO, that clean-up
water would be high in oil and grease. Pollutant discharge, on a Ibs.
43
-------
Table 13. Raw Wastewater Concentrations for Complex and On-Site
Facilities, mg/1.
Plant
A. Complex
Facilities:
RWA.01
RWA.02
RWA.03
RWA.04
RWA.05
RWA.06
RWA.07
RWA.08
AVERAGE
B. On -Site
Facilities:
RWB.01
RWB.02
RWB.03
RWB.04
RWB.05
AVERAGE
pH
1.9-10.3
2.3-9.9
6.5-8.8
7.3
2.4-9.1
7.3-8.1
1.9-10.3
7.9
6.7
6.7
6.2-7.2
6.2-7.9
BOD
1463.0
7.8
36.4
628.0
29.0
8.0
362.0
51
7
1
300
19.9
75.8
COD
2323.9
114.3
153.3
1175.0
95.0
30.0
648.6
183
62
12
112.0
92.3
Total
Solids
588.3
1763.8
1118.3
1646.0
1880.0
2192.7
1531.5
71
861.6
466.3
Susp.
Solids
73.0
19,4
55.9
292.0
42.0
77.8
93.4
30
120
398.3
182.8
Oil &
Grease
0.82
0.01
11.9
35.0
3.4
10.2
44
-------
Table 13. Raw Wastewater Concentrations for Complex and On-Site
Facilities, mg/1. (Continued)
Plant
A. Complex
Facilities:
RWA.01
RWA.02
RWA.03
RWA.04
KWA.05
RWA.06
RRA.07
RWA.08
AVERAGE
B. On-Site
Facilities:
RWB.01
RWB.02
RWB.03
RWB.04
RWB.05
AVERAGE
Total
Org. N
104 o 4
110.4
107.4
Kjel.
N
417.9
23.6
230.0
6.1
169.4
51
6.15
28.6
NH3-
N
•
413.5
93.3
22.6
211.0
77.1
163.5
82
158
5.0
81.7
N03-
N
714.5
170.9
79.0
267.0
92.0
264.7
373
1150
0.47
2.59
381.5
N02-
N
1.8
2.2
1.5
9.0
0.3
3.0
Sulfate
21.8
353.5
36.9
581.7
27.4
315.4
222.8
4-5
-------
Table 14. Daily Pollutant Discharges
Facilities, Ibs/day.
for Complex and On-Site
Plant
A. Complex
Facilities:
DDA.01
DDA.02
DDA.03
DDA.04
DDA.05
DDA.06
DDA.07
AVERAGE
B. On -Site
Facilities:
DDE. 01
DDB.02
DDE. 03
AVERAGE
BOD
1076.2
163.9
465
1519
72
10.9
551.2
0.06
0.20
3.07
1.09
COD
1751.5
2402.2
1956
2866
238
37.5
1541.9
0.09
2.30
17.28
6.56
Total
Solids
1257.1
37,069.4
14,269
3970
4700
2743
10,668
14.00
132.94
73.47
Susp.
Solids
156.0
407.7
713
730
105
97.3
368.2
6.00
61.45
33.73
Oil &
Grease
0.21
152
81.8
8.5
60.6
46
-------
Table 14. Daily Pollutant Discharges for Complex and On-Site
Facilities, Ibs/day. (Continued)
Plant
A. Complex
Facilities:
DDA.01
DDA.02
DDA.03
DDA.04
DDA.05
DDA.06
DDA.07
AVERAGE
B. On-Site
Facilities:
DDE. 01
DDE .02
DDB.03
AVERAGE
Tot.
Org. N
38.3
2320.2
1204.3
Kjel-
N
893.0
301.1
575.5
7.6
444.3
10.00
0.95
5.47
NH3-
N
883.5
1960.9
288
528
96.4
751.4
0.24
0.77
0.51
N03-
N
1526.7
3591.8
1008
668
115.1
1381.9
1.76
0.10
0.39
0.73
N02-
N
3.84
0.81
31.53
22.5
0.38
11.8
Sulfate
46.60
131.0
776.3
7422.2
82.3
394.6
1475.5
47
-------
Table 15. Production-Based Pollutant
Facilities, Ibs/ton.
Discharge for Complex and On-Site
Plant
A . Complex
Facilities:
PBA.01
PBA.02
PBA.03
PBA.04
PBA.05
PBA.06
PBA.07
AVERAGE
B. On-Site
Facilities:
PBB.01
PBB.02
PBB.03
AVERAGE
BOD
12.7
0.44
3.32
112.5
0.72
0.17
21.64
0.000
0.003
0.512
0.172
COD
20.6
6.46
13.97
212.3
2.38
0.60
42.72
0.003
0.036
2.880
0.973
Total
Solids
14.8
99.65
101.92
294.1
47.0
43.9
100.2
0.219
22.156
11.187
Susp.
Solids
1.8
1.1
5.09
54.1
1.05
1.56
10.78
0.094
10.242
5.167
Oil &
Grease
0.00
1.09
6.1
0.09
1.82
48
-------
Table 15. Production-Based Pollutant Discharge for Complex and On-Site
Facilities, Ibs/ton. (Continued)
A. Complex
Facilities:
PBA.01
PBA.02
PBA.03
PBA.04
PBA.05
PBA.06
PBA.07
AVERAGE
B. On-Site
Facilities:
PBB.01
PBB.02
PBB.03
AVERAGE
Tot.
Org. N
0.53
6.24
3.32
Kjel-
N
10.5
2.15
5.76
0.12
4.63
0.156
0.157
0.157
NH3-
N
10.4
5.27
2.06
5.28
1.54
4.91
0.007
0.129
0.068
N03-
N
18.0
9.66
7.20
6.68
1.84
8.68
0.050
0.002
0.067
0.040
N02-
N
0.05
0.01
0.08
0.23
0.01
0.08
Sulfate
0.55
1.82
2.09
53.02
0.82
6.30
10.77
49
-------
per day basis, is much smaller for on-site then complex facilities,
reflecting the smaller size of these plants, the approximately one
hundred fold less flow volume (Table 11), and the lower pollutant con-
centrations shown in Table 13. Similar results are observed in Table 15,
where pollutant discharges have been normalized on a Ibs. per ton final
explosive product basis.
The average data for the complex and on-site plants indicates a
BOD discharge of 21.6 vs 0.17 Ibs/ton of product, a suspended solids
discharge of 10.8 vs 5.2 Ibs/ton and nitrate nitrogen discharge of 8.7
vs 0.04 Ibs/ton product. Thus, the categorization of the explosives
industry into complex and on-site plant is justified by both a wastewater
volume and mass pollutant discharge (per ton product) basis.
Only limited data were available on the wastewater characteristics
associated with the manufacture of intermediate and specialty products
of the explosive industry. These data are presented in Tables 16-18.
As in the case of plant-wide wastes, there is a great deal of variability
in waste nature from plant to plant. Products for which detailed data
were available included nitrogen facilities manufacturing ammonia, nitric
acid and ammonium nitrate, nitroglycerine and PETN production, and
blasting caps. Tables 16-18 also contain data from three plants using
water scrubbers for dust control in dynamite formulation facilities.
Nitrogen plant wastes are characterized by low pH and BOD, moderate
suspended solids and oil and grease, and moderate to high nitrogen levels
(Table 16). Total nitrogen discharge exceeds 3.8 Ibs. per ton of nitro-
gen facility product, as shown in Table 18. BOD and oil and grease are
each less then 0.1 Ibs. per ton.
The pH of wastewater from NG manufacture range from low for the
first (sour water) wash after nitration, to alkaline for the subsequent
washes with sodium carbonate to neutralize residual acidity. In addition,
these wastes-are typically saturated with nitroglycerin, at up to 2500
mg/1 NG. The neutralizing wash yields high sodium levels (above 10,000
mg/1), which is reflected in the high total solids. Concentrations of
suspended solids are also typically high, although the source and nature
of the suspended solids is unknown. Residual nitro- and dinitroglycerin
50
-------
Table 16. Wastewater Concentrations for Specialty and Intermediate
Products, mg/1.
Plant
A. Nitrogen Plants:
A.01
A. 02
A. 03
A. 04
AVERAGE
Bo Nitroglycerine
B.01
B.02
B.03
B.04
B.05
AVERAGE
G. PETN:
C.01
C.02
D. Dynamite Mix House
Dust Control:
D.01
D.02
D.03
AVERAGE
E. Blasting Caps:
E.01
E.02
pH
3.1
2.3
2.3-3.1
2.7-10.0
8-9
9.8
2.7-10.0
1.9
5.5-7.0
7.4
7-8
7-8
5.5
7.6
BOD
9.0
18.0
13.5
352
167
260
2640
40
136
6.4
71.2
84
1.2
COD
556
16
135
127
208
709
3518
2553
2260
5700
80
425
74
250
166
41.6
Total
Solids
2752
354
1793
1318
1554
2110
81,527
63,859
49,165
501
455
1080
319
699
363
434
Susp.
Solids
543
4
37
39
156
1894
46
65
668
1
5
128
14
71
15
21.5
51
-------
Table 16. Wastewater Concentrations for Specialty and Intermediate
Products, mg/1. (Continued)
Plant
A. Nitrogen Plants:
A. 01
A. 02
A. 03
A. 04
AVERAGE
B. Nitroglycerin:
B.01
B.02
B.03
B.04
B.05
AVERAGE
C. PETN:
C.01
C.02
D. Dynamite Mix House
Dust Control:
D.01
D.02
D.03
AVERAGE
E. Blasting Caps:
E.01
E.02
Oil &
Grease
42.9
0.01
14.5
19.1
313
313
5.5
Total
Org. N
364
600
482
483.7
0.0
242
0.0
3.8
1.9
1.20
Kjel-
N
17.9
37.2
27.6
2.88
43.2
23.0
3.2
4.0
1516
1516
0.54
0.32
NH3-
N
180
16
532
36.2
191.1
2.45
0.0
33.7
12.1
0.6
2.0
1503
0.0
752
0.32
N03-
N
564
95
73
77.7
202
344
12,500
3849
5564
172.0
49.0
2500
7
1254
30.4
13.4
52
-------
Table 16. Wastewater Concentrations for Specialty and Intermediate
Products, mg/1. (Continued)
Plant
A. Nitrogen Plants:
A.01
A.02
A. 03
A. 04
AVERAGE
B. Nitroglycerin:
B.01
B.02
B.03
B.04
B.05
AVERAGE
C. PETN:
C.01
C.02
D. Dynamite Mix House
Dust Control:
D.01
D.02
D.03
AVERAGE
E. Blasting Caps:
E.01
E.02
N02-
N
1.1
6.3
3.7
1.36
0.38
0.87
Sulfate
305
11
85
850
312
2259
208
6996
3154
NG
900-2500
315-12,700
315-12,700
Sodium
14,879
11,767
13,323
53
-------
Table 17. Daily Pollutant Discharges for Specialty and Intermediate
Products, Ibs/day.
Plant
A. Nitrogen Plants:
AA.Q1
AA.02
AA.03
AA.04
AVERAGE
B. Nitroglycerine
BB.01
BB.02
BB.03
BB.04
AVERAGE
C. PETN:
CC.01
CC.02
D. Dynamite Mix House
Dust Control:
DD.01
DD.02
DD.03
E. Blasting Gaps:
EE.01
EE.02
BOD
22.5
140.5
81.5
58.7
5.85
32.3
220.2
240
79.4
50.7
288.6
0.88
COD
334
3.3
337.5
991.4.
416
28.4
586.8
89.4
234
475.4
322
248.1
586
570.4
30.5
Total
Solids
1675
33.8
4482
10,288
4112
84.5
13,599
2237
5307
41.8
1860
630.5
2526
1227
318
Susp.
Solids
326
0.8
92.5
304.4
181
25.8
7.7
2.28
11.9
0.1
20.0
74.7
111
55.5
15.8
Oil &
Grease
26
0.02
113.2
46.4
10.96
10.96
18.9
54
-------
Table 17. Daily Pollutant Discharges for Specialty and Intermediate
Products, Ibs/day. (Continued)
Plant
A. Nitrogen Plants:
AA.01
AA.02
AA.03
AA.04
AVERAGE
B. Nitroglycerin:
BB.01
BB.02
BB.03
BB.04
AVERAGE
C. PETN:
CC.01
CC.02
D. Dynamite Mix House
Dust Control:
DD.01
DD.02
DD.03
E. Blasting Caps:
EE.01
EE.02
Tot.
Org. N
219
1500
859
8.87
0.0
4.44
0.0
0.06
4.12
0.23
Kjel-
N
3.7
290.4
147.1
0.1
1.51
0.76
0.3
16.0
885.0
0.23
NH--
N
108
3.3
1330
282.6
431
0.1
0.0
1.18
0.43
0.1
8.0
877.5
0.0
104.6
9.83
NO,-
N
338
19.8
182.5
606.5
202
13.8
2085
134.8
744
14.3
197.0
1459.5
55.4
55
-------
Table 17. Daily Pollutant Discharges for Specialty and Intermediate
Products, Ibs/day. (Continued)
Plant
A. Nitrogen Plants:
AA.01
AA»02
AA.03
AA.04
AVERAGE
B. Nitroglycerin:
BB.01
BB.02
BB.03
BB.04
AVERAGE
C. PETN:
CC.01
CC.02
D. Dynamite Mix House
Dust Control:
DD.01
DD.02
DD.03
E. Blasting Caps:
EE.01
EE.02
N02
N
0.23
15.8
8.0
0.05
0.01
0.03
0.01
0.04
5.5
0.0
Sulfate
183
2.3
212.5
6635
1758
41.4
34.7
245.1
107.1
NG
145-417
145-417
Sodium
2482
412.2
1447
56
-------
Table 18. Production-Based Pollutant Discharge for Specialty and
Intermediate Products, Ibs/ton.
Plant
A. Nitrogen Plants:
AAA.01
AAA.02
AAA.03
AVERAGE
B. Nitroglycerin:
BBB.01
BBB.02
BBB.03
BBB.04
AVERAGE
C. PETN:
CCC.01
D. Dynamite Mix House
Dust Control:
ODD. 01
ODD. 02
DDD.03
BOD
0.07
0.07
3.13
0.32
1.73
62.9
0.93
1.16
COD
1.67
0.05
1.05
0.92
2.58
31.3
4.97
13.0
135.8
2.92
13.34
Total
Solids
8.38
0.52
14.00
7.63
7.68
725.3
124.3
285.8
11.9
7.42
57.53
Susp.
Solids
1.63
0.01
0.29
0.64
2.35
0.4
0.12
0.96
0.03
0,88
2.53
Oil &
Grease
0.13
0.00
0.06
0.61
0.61
57
-------
Table 18. Production-Based Pollutant Discharge for Specialty and
Intermediate Products, Ibs/ton. (Continued)
Plant
A. Nitrogen Plants:
AAA.01
AAA.02
AM. 03
AVERAGE
B. Nitroglycerine
BBB.01
BBB.02
BBB.03
BBB.04
AVERAGE
C. PETN:
CCC.01
D. Dynamite Mix House
Dust Control:
ODD. 01
DDD.02
ODD. 03
Tot.
Org. N
1.10
4.69
2.90
0.99
0.99
0.0
0.0
Kjel-
N
0.06
0.06
0.01
0.08
0.05
0.09
10.41
NH3-
N
0.54
0.05
4.16
1.58
0.01
0.07
0.04
0.03
10.32
0.0
N03-
N
1.69
0.30
0.57
0.85
1.25
111.2
7.49
40.0
4.1
17.17
1.26
58
-------
Table 18. Production-Based Pollutant Discharge for Specialty and
Intermediate Products, Ibs/ton. (Continued)
Plant
A. Nitrogen Plants:
AM. 01
AAA.02
AAA.03
AVERAGE
B. Nitroglycerine
BBB.01
BBB.02
BBB.03
BBB.04
AVERAGE
C. PETN:
CCC.01
D. Dynamite Mix House
Dust Control:
DDD.01
ODD. 02
ODD .03
N02-
N
0.00
0.05
0.03
0.00
0.00
0.00
0.00
0.13
0.0
Sulfate
0.92
0.04
0.66
0.54
4.6
1.85
13.6
6.68
NG
7.8-22.2
7.8-22.2
Sodium
132.4
22.9
77.7
59
-------
glycol, which show up as "oil and grease," result in high readings for
this latter parameter, and also yield high BOD values. The nitrating
acid, being a mixture of nitric and sulfuric acids, results in high
nitrate and sulfate levels in the wash waters. Nitrate nitrogen dis-
charge (Table 18) averages 40.0 Ibs/ton NG produced.
Rudolfs (8) has also reported mass pollutant discharge for nitro-
glycerin manufacture. His data, expressed as Ibs/ton NG are given below:
BOD5 3.94 Ibs/ton
Suspended Solids 6.36
Nitrate-N 114.80
Nitrite-N 4.22
Sulfate 37.80
The above data are much higher then the values found in this study.
Limited data on PETN manufacture indicate acidic to neutral waste-
waters, which may be high in BOD if acetone recovery is incorporated in
the PETN process. Nitrate levels are high, reflecting the use of nitric
acid in the nitration reaction. The primary water use in blasting cap
manufacture is wash and clean-up water, and Table 16 indicates that the
resultant wastewater contains low to moderate levels of contaminants.
In summary, waste characteristics of the industry as a whole include
pH varying from extremely low to high values, BOD and suspended solids
of moderate to high concentrations, and typically high nitrogen and
sulfate levels. Wastewaters associated with particular intermediate
specialty products typically show even more extreme ranges for the above
pollutants. There are significant data gaps, as evidenced by the results
reported in Tables 13-18, and it is likely that insufficient data is
available for on-site plants and specialty production activities to pro-
vide valid averages.
60
-------
VIII. TREATMENT TECHNOLOGY
The major water pollutants resulting from explosives manufacture
are summarized in Table 19. Most are common to all categories of pro-
duction facilities. Within the industry, these wastewaters result from
product process effluents, equipment clean-up and cooling water.
Sanitary wastes are in most cases handled on a separate basis, typically
with septic systems. Exclusive of this waste, the most critical pollu-
tants of the explosives industry are extreme pH, BOD,., suspended solids,
oil and grease, nitrogen forms, residual explosives (NG), and high
dissolved solids. Particularly contributing to the dissolved solids is
sulfate and for some processes, sodium.
Settling tanks and sumps are used in all plants visited, to remove
suspended solids. Due to inadequate maintenance and hydraulic overload,
these catch basins are often not effective, resulting in high effluent
suspended solids. In some instances, screening precedes the catch basin,
but does not appear to significantly improve solids removal. Average
effluent suspended solids discharge for complex facility was 93.4 mg/1
and for on-site plants 182.8 mg/1. Several aspects of complex facility
operation contribute to this difference in effluent suspended solids
levels. Among these are dilution of the wastes with cooling water,
greater care to avoid undue loss of intermediate and product explosives,
and wider use of dry clean-up procedures in the complex facilities. A
comparison of suspended solids discharge for complex facilities routinely
practicing dry clean-up prior to final equipment washdown indicates an
average suspended solids discharge of 30.7 mg/1, as compared with the
industry average of 93.4 mg/1. This represents a reduction in suspended
solids discharge of greater then 60 percent, plus reduction in clean-up
water volume. In many instances, it appears that dry clean-up techniques
alone will satisfy suspended solids discharge requirements, with the
additional benefits of reduction in water use and recovery of product.
Since much of the suspended solids is nitrogenous and organic in nature,
associated benefits of dry clean-up would be reduction of discharge levels
of these pollutants as well. For example, average BOD,, concentration for
61
-------
Table 19. Major Pollutants of the Commercial Explosives Industry.
Parameter
PH
BOD
COD
Tot. Solids
Susp. Solids
Oil/Grease
Tot. Org. N
Kjel.-N
NH--N
N03-N
Sulfate
Complex
Facilities
X
X
X
X
X
X
X
X
X
X
X
On-Site
Facilities
X
X
X
X
X
ND
ND
X
X
X
ND
Nitrogen
Plants
X
X
X
X
X
X
X
X
X
X
NG
X
X
X
X
X
X
X
X
X
X
X
PETN
X
X
X
X
ND
ND
X
Dust
Control
X
X
X
X
ND
X
X
X
Blast.
Caps
X
X
X
ND
ND
X
ND = No Data Available.
62
-------
complex facilities employing dry clean-up is 18.4 mg/1 versus the in-
dustry average of 362.2 mg/1. Among the complex facilities, 37.5
percent of those plants for which discharge data was available employ
dry clean-up. Excluding these facilities, the average suspended solids
and BOD,, discharge levels for the remaining plants was 124.7 and 533.8
mg/1, respectively. Thus, it appears that good housekeeping practices
can have a major effect in reducing pollutant discharge. Dry clean-up
is commonly by sweeping and wiping of equipment, although one plant
utilizes a vacuum system.
Use of oil skimmers is also prevalent within the industry. The
waste oil collected in these units is often sprayed on dirt roads within
the boundaries of the plant, for dust control. Oily wastes are associ-
ated with many aspects of explosives manufacture, including ANFO formu-
lation, oil leakage from pumps and motors, and chemicals such as NG
which show up as oil. Average oil discharge from complex facilities
utilizing oil skimmers is less then 2 mg/1, as compared to the industry
average of 10.2 mg/1. Oil skimmers are effective only in separation of
non-emulsified oil (9). It is probable that this is the major fraction
of oil in the wastewaters of the explosives industry, due to the sources
of oily wastes. The effectiveness of a gravity-type oil separation
depends upon proper hydraulic design, and design period of wastewater
retention. Retention times of less then one hour may yield oil removal
efficiencies of only 60 percent or less (10). Well designed oil separa-
tions should yield effluent oil levels of less then 10 mg/1 (9). The
oil levels reported for the explosives industry are near this limit, and
it is unlikely that use of skimmers alone will achieve any significant
reduction in present discharge of oily wastes.
Neutralization is employed to a limited extent within the industry,
due to the pH extremes encountered with various process waste streams.
This is a problem more of the complex facilities than on-site plants,
which typically discharge near-neutral pH wastewaters. Acidic wastewaters
originate from acid production and recovery, and from nitration pro-
cesses such as for NG or PETN. In the plants visited neutralization
treatment, if practiced, was limited to the first (acidic) wash water
63
-------
from NG manufacture. Neutralization was by percolation of the waste-
water through crushed limestone beds. Available data indicates that
the process was inefficient, with at least two plants reporting
effluent pH of 2.7 and 3.6, after neutralization. It is probable that
the high sulfate content of the NG wash water results in precipitate
formation, thereby coating the crushed limestone and preventing its
reaction. Other wastewaters of extreme pH, including acidic wastes
from acid manufacture, acid recovery and nitration processes, and alka-
line wastes from acetone still bottom and sodium carbonate wash solution
for NG, are also unneutralized by the industry. Typically the alkaline
NG wash, having pH 9-10, is mixed with other plant wastes and released
without treatment. There appears to be little reason why the industry
could not reuse this wash water, adding additional sodium carbonate as
necessary to provide sufficient neutralizing capability. Each batch
discharge of alkaline wash water contributes high dissolved solids,
particularly nitrate and sulfate, to the waste flow and, being saturated
with NG, increases the effluent nitroglycerin and the BOD and oil and
grease characteristics associated with the presence of NG. Where
recycle does not prove feasible, the alkaline wash water could be used
to neutralize effluent from the limestone beds. This would also reduce
dissolved solids, through precipitation of calcium sulfate. The extreme
pH nature of wastewaters of the industry, even where limestone neutra-
lization is practiced, indicates need for additional pH adjustment into
the near-neutral range.
The technology and economics of pH control are well established,
and there are many acceptable methods for treating both acidic and basic
wastes. Accepted methods cited by Patterson and Minear (9) include:
1) mixing acid and alkaline wastes so that the net effect is a near-
neutral pH; 2) passing acidic wastewaters through beds of limestone;
3) mixing acid wastes with lime or dolomitic lime slurries; and 4)
adding the proper amounts of concentrated caustic (NaOH) or soda ash
(Na9COo) to acid wastewaters. Rudolfs (8) has emphasized the need for
neutralization of acid explosives wastes and reports that dolomitic
lime is effective and economical. Koziorowski and Kucharski (4) confirm
64
-------
the need for explosives waste neutralization, and report most effective
and economic treatment results from separation of effluents with a high
acid content from less acidic wastes. Dolomite quicklime and slaked
lime are recommended as most suitable material for pH control. Equali-
zation tanks are suggested to provide most effective dosage for control
(4). This may become particularly appropriate where waste flows are
intermittent, as with the batch washing of nitroglycerin. Dickerson
(11), reporting experience in treating acidic wastes of an explosives
plant, found that ground limestone was most effective in neutralizing
wastes containing below 4000 mg/1 acid, while dolomitic lime was pre-
ferred for more concentrated waste streams.
In addition to the acidic waste streams, the possibility of
accidental spills of concentrated acids exists at the complex facilities.
Each of the plants visited incorporates an emergency catch basin to
which acid spills can be diverted.
The wash waters from nitroglycerin manufacture, in addition to
extreme pH, BOD and suspended and dissolved solids, contain high nitrate,
sulfate and dinitroglycerin levels plus from several hundred to several
thousand mg/1 of dissolved nitroglycerin. The NG has a solubility of
1,380 mg/1 at 20 C, and will precipitate out as an oily substance at
temperatures below that of the process wastewater. This represents an
explosives hazard, due to the sensitive nature of the NG. All NG waste-
waters flow through one or more catch boxes, in series, to retrieve pre-
cipitated NG. However, the effluent from these catch boxes still con-
tain high concentrations (100-1000 mg/1) of dissolved dinitroglycerin
and NG, which exert high BOD and could precipitate further in receiving
waters. Therefore, further treatment for removal of dissolved NG should
be considered.
Koziorowski and Kucharski (4) have reported on studies to determine
if nitroglycerin effluents could be treated by biological methods,, After
preliminary settling the wastes, containing 900 to 2100 mg/1 of NG, were
treated by activated sludge. The decomposition product was nitrite. The
authors report successful treatment with 16 hours aeration time, although
the maximum concentration of NG which could be treated successfully was
400-500 mg/1.
65
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Attempts to destroy nitroglycerin by quickline were also success-
ful (4), resulting in its decomposition and the formation of calcium
sulfate, calcium sulfite and calcium salts of low molecular weight
organic acids. After the wash water had been settled, lime was added
at up to 2 g/l0 The decomposition process required 3 days reaction
time. The sludge formed in the process was stable with no explosive
properties, although the effluent was highly alkaline.
The U.S. Army, in assessing treatment technology applicable to
wastewaters of military explosives manufacture, has considered biolo-
gical as well as several chemical treatment schemes to remove NG and
dinitroglycerin. Biological treatment of wastewaters containing
approximately 1500 mg/1 NG and 850 mg/1 of dinitroglycerin (DNG) has
been only partially effective (12). In assessing physical and chemical
methods to treat NG wastewater, Smith (13) reports effective removal of
sodium alkalinity from the neutralizing wash by lime plus calcium sul-
fate addition. Carbonate and bicarbonate alkalinity are precipitated
as calcium carbonate. This process will, however, increase the sulfate
content of the wastewater. Estimated cost for the process was $2.56
per 1000 gallons. Activated carbon adsorption was found ineffective
for removal of NG. Smith (13) has also reported successful complete
treatment of NG and DNG by both permanganate and ozone oxidation, at
long detention periods. Ozone requirement was estimated at 24 Ib/lb NG
and DNG, resulting in high (approximately $40.00 per 1000 gal.) treat-
ment costs.
Biological treatment by both activated sludge and lagoons appears
to have potential for treatment of explosives wastes. One plant,
producing smokeless powder plus NG and other intermediates, uses extended
aeration activated sludge, followed by lagooning, to treat the combined
plant flow. The activated sludge unit operates with 24 hours aeration
at 8000-9000 mg/1 mixed liquor suspended solids. There is little excess
sludge wasting required for the plant. The lagoon has 5-10 days deten-
tion time, and is aerobic to facultative anaerobic,, depending upon
temperature and waste loading to the lagoon. Table 20 presents operating
data on the treatment system. A comparison of the influent data of
66
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Table 20. Treatment Plant Operation and Average Waste Concentrations, mg/1
Parameter
pH - Range
Total Solids
Suspended Solids
BOD5
COD
BOD5/COD
Phosphorus
Chlorides
Oil and Grease
Ammonia -N
Kjeldahl -N
Nitrate -N
Nitrite -N
Sulfate
Influent
6.5-8.8
1646
292
628.0
1175
0.53
0.28
97.0
35.0
—
—
—
—
351.4
Activated Sludge , _--.
Effluent Lagoon EfflueQt
7.4-8.4 7.5-10.5
1137
47
29.2 16.8
177 114
0.16 0.15
- 0.15
107.1
- 8.0
0.25
0.17
0.04
0.1
76.6
Percent
Removal
30.9
83.9
97.3
90.3
46.4
77.1
78.2
-------
Table 20 with the average data for complex facilities (Table 13),
indicates that this plant's flow is similar in nature to the industry
average. Although only limited data are given for the activated sludge
effluent, this process results in BOD_ removal exceeding 95 percent.
Table 20 also summarizes the treatment efficiencies for the activated
sludge plus lagoon treatment sequence. Although influent nitrogen
levels are not known, they are likely near these shown in Table 13.
Effluent nitrogen levels are below 0.3 mg/1. The effluent from the
lagoon is spray irrigated on a four acre field, at 3 inches hydraulic
loading per month.
Dickerson (11) has also reported the use of biological treatment
for a smokeless powder explosives waste. Based upon pilot studies, a
two-stage trickling filter was employed to treat process effluents
ranging up to 4500 mg/1 in BOD,.. Operation at hydraulic loadings of
20 MGAD on both units, with a recycle ratio of 20:1, yielded BOD
removal of 97.5 percent and effluent BOD of 90 mg/1. Lower hydraulic
loading rates (8-16 MGAD) slightly improved treatment efficiency,
yielding a final effluent BOD of 55 mg/1. However, severe problems
were experienced with clogging of the filters at the lower hydraulic
loading rates.
Biological treatment for nitrogen forms appears to be an effective
and acceptable type of technology. The explosives industry wastewaters
are typically high in both ammonia and nitrate nitrogen. Industry
averages for complex and on-site plants are 163.5 and 81.7 mg/1 NEL-N,
and 264.7 and 381.5 mg/1 NO^-N, respectively. Activated sludge nitri-
fication of both dilute and concentrated ammonia wastewaters is well
established (14,15). Although most research on nitrification has been
directed toward wastewaters containing less then 60 mg/1 NH,,-N, limited
work on more concentrated wastewaters has shown effective biological
treatment. The feasibility of ion exchange or other physical-chemical
methods of control have also been proven (16, 17), although the high
nitrate levels of most explosives industry wastewaters indicate that a
combination of biological nitrification-denitrification is likely to be
the treatment method of choice. Button and La Rocca (15) reported on
-------
the use of biological oxidation as a means to treat high ammonia waste-
waters from the manufacture of ammonium nitrate and urea fertilizers.
The waste studied was similar to the explosives industry average, being
high in N1U-N (445 mg/1), total solids (1845 mg/1) and nitrate plus
nitrite (75 mg/1). Total organic carbon varied from 1 to 170 mg/1,
averaging 55 mg/1. Operating with a low MLVSS system of 130 mg/1, due
to the low organic carbon concentration of the wastewater, NEL-N oxida-
tion of 90 percent resulted with solids retention time of 30 days and
process loading of 0.5 Ibs NH3-N/day/lb MLVSS, Operating temperatures
of 60-70 F and pH of 8.0-8.4 was required. Factors improving nitrifi-
cation included longer solids retention times, higher temperature and
lower nitrogen loading.
Currently, the commercial explosives industry has no nitrate
abatement technology in use, although the U.S. Army has investigated
several methodologies for nitrate treatment for their military explosives
plants. After initial feasibility studies, the U.S. Army has selected
biodenitrification, ion exchange and reverse osmosis as the processes
having greatest potential for nitrate removal from explosives waste-
waters (18). Table 21 summarizes the results of the preliminary feasi-
bility studies carried out by the Army, and indicates that on the basis
of treatment efficiency plus cost, biodenitrification is likely to be
the method of choice. On the basis of product recovery however, both
ion exchange and reverse osmosis have advantages.
At the present time, application of reverse osmosis is largely
limited to desalination and production of drinking water, and recovery
of products in the food processing and electroplating industries (19).
Investigations of reverse osmosis as a method of concentrating nitrate
wastes are few, and those reported in the literature indicate variable
results (20-22). Advantages of reverse osmosis include its low energy
requirement and its corrosion free operation in contrast to evaporative
systems. However, reverse osmosis membranes are affected by pressure,
chemical change and hydrolysis, bacteria, temperature and surface
coating (23).
The Army has investigated on a pilot scale reverse osmosis treatment
69
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Table 21. Nitrate Treatment Methods (18).
...... Removal Approx. Cost,
Met nod „,.«•.. m A /,.-
Efficiency, % $/MG
Biodenitrification 70-95 3.45-30
Algae Harvesting 50-90 20-35
Ion Exchange 80-99 170-300
Electrodialysis 30-50 100-250
Chemical Reduction 33-90 —
Reverse Osmosis 50-96 100-600
Distillation 90-98 400-1000
Land Application 5-15
70
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of nitrate wastewaters. At pH 1.5, no nitrate removal occurred although
99 percent sulfate removal was achieved. Nitrate removal efficiency
increased with increasing pH, to 90 percent at pH 7.0. Sulfate removal
was not found to be pH dependent, with reverse osmosis achieving 99
percent sulfate separation at all pH values tested. However, it appears
that the lower limit of osmosis treatment is near 20 mg/1 NCL-N, and
that achieving lower concentrations would not be economically feasible.
Reverse osmosis application thus appears to be best suited for nitrate
recovery, with subsequent treatment of the dilute permeate by other
means such as biodenitrification or ion exchange. The Army is con-
tinuing to investigate reverse osmosis, utilizing low-pH resistant
sulfonated polyphenylene oxide (SPPO) membranes, with evaporative
concentration of the process brine to recover mixed nitric and sulfuric
acid for reuse. This process if feasible, will both eliminate the need
for neutralization and provide product recovery.
The study of ion exchange treatment for nitrate removal has been
largely limited to the abatement of low nitrate concentrations (24-26).
One historical problem with the use of ion exchange for nitrate treat-
ment has been the lack of resin specificity for nitrate. However,
nitrate selective resins have recently become available (27, 28). The
only reported ion exchange system in full-scale use for the treatment
of high nitrate concentrations is the Chemical Separations Corporation
Continuous Counter-Current (Chem-Seps) Ion Exchange System (18). This
system has been installed at the Farmers' Chemical Association, Inc.
plant (Tyner, Tennessee), a manufacturer of ammonium nitrate. The
system is reported to reduce nitrate levels of 1240 mg/1 at 0.9 M3D,
to effluent concentrations of 7-11 mg/1, in the presence of other ions.
The regenerants used are nitric acid and ammonium hydroxide, with
ammonium nitrate (concentration about 19%) being recovered in the resin
regeneration step.
The application of this process for complex facilities appears
particularly feasible, since most of the larger explosives plants use
ammonium nitrate as an intermediate in explosives manufacture. The Chem-
Seps process, in addition to nitrate removal, is reported to reduce
71
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-N levels from 340 to 2-3 mg/1. The sulfate level of the waste
being treated was only 72 mg/1 (20), and it is possible that the higher
sulfate levels associated with explosives wastewaters may interfere
with effective nitrogen removal. However, preliminary studies by the
Army indicate reduction of nitrate from 1650 to 20 mg/1, even in the
presence of high sulfate concentration (29). The process, using DOWEX
Resin MWA-1, also reduced sulfate from 4320 to 200 mg/1. The process,
for a 3 MGD flow, is estimated to require a capital investment of
$1,650,000.
Of all nitrate treatment processes, biological denitrification has
been most intensively studied. Most of these investigations have been
directed toward removing nitrate from municipal wastewaters (14). The
U.S. Army has carried out pilot scale suspended growth biodenitrifica-
tion studies at two of its contractor operated munitions plants (18).
Initial studies indicated that detention times exceeding ten days were
required for 90 percent or greater nitrate reduction, at suspended
solids levels of 100-200 mg/1. A modified 5000 gpd pilot unit, operat-
ing at 1000-3000 mg/1 suspended solids, is reported to achieve 93
percent denitrification with an 18 hour detention time. Average
influent NO_-N of 558 mg/1 is reduced to 47 mg/1 effluent concentration.
At influent NO_-N concentrations below 400 mg/1 and suspended solids
below 1400 mg/1, the process has yielded effluent nitrate levels of 1
mg/1, however (29). The primary disadvantages of the biodenitrification
process are the needs for close pH and temperature control, and the
large quantities of methanol required. At a nitrate level of 500 mg/1,
about 5 tons of methanol is required per million gallons of waste
treated (30).
The high sulfate levels associated with explosives wastewaters may
require treatment. Although the commercial explosives industry has not
to date specifically considered sulfate as a pollutant requiring abate-
ment, the U.S. Army has begun to investigate technologies appropriate
for sulfate control. At present, their studies are only in the initial
assessment stages, and no proven process exists within the explosives
industries. Methods reported under consideration include (31):
72
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1. Reverse Osmosis - Separation of sulfate from the
wastewater by use of suitable membranes, to pro-
duce water for plant reuse and concentrated brine
for reclamation processes.
2. Ion Exchange - Removal of sulfate by use of
sulfate specific resins^ producing reclaimed
water and a useful by-product resulting from
the regeneration of the ion exchange bed.
3. Evaporation - Combined use of reverse osmosis
and evaporation techniques to recover sulfuric
acid.
4. Calcination - Produce calcium sludge by preci-
pitation with lime, followed by high temperature
calcination to evolve sulfur dioxide for sulfuric
acid production, plus lime recovery.
Reverse osmosis has been investigated at pilot scale, in combina-
tion with nitrate removal. High sulfate removal efficiencies (99+%)
are reported even at acidic pH. However, membrane hydrolysis at low pH
greatly decreases useful membrane life. In the absence of more resis-
tant membranes, neutralization would likely be required for the reverse
osmosis feed stream. This may result in precipitation, and fouling of
the membranes by solids.
The most technically feasible method of sulfate treatment appears
to be calcination. However, the solubility of calcium sulfate is high
(app. 470 mg/1 of sulfate), and lime treatment may not be feasible for
more stringent effluent requirements. The use of barium to precipitate
sulfate has been suggested (30), but cost and the possibility of exceed-
ing effluent barium levels appear to be major disadvantages.
The economic and technical difficulties associated with treatment
for pollutants such as nitrate and sulfate has led to several applications
of waste disposal by land irrigation in the explosives industry. During
73
-------
the course of this study; two complex facilities and one on-site plant
were visited which employed spray irrigation for wastewater disposal.
Only one of these plants was located in an arid region, the second
being in the upper midwest and the third in the southeast. For two
plants, the only waste treatment preceeding spray irrigation was gravity
settling of solids. The on-site facility, a water gel femulator, has
an extremely low waste flow of 25-30 gpd. This flow is collected in a
tank truck and, as necessary, sprayed onto an abandoned mine overburden
disposal site on the plant property..
The complex facility located in an arid region produces ANFO,
dynamites and various intermediate and specialty products. Following
sedimentation and oil skimming, the wastewater is spray irrigated onto
a 12 acre pasture of bermuda grass, at 11.7 gpm/acre. The pasture is
used to graze cattle. However, the land is currently overloaded
hydraulically, and plans to expand the irrigation area by 20-40 addi-
tional acres are underway. This will reduce hydraulic loading to
2.7-4.4 gpm/acre.
The third instance of disposal by irrigation involves a complex
facility which pretreats its waste by activated sludge and lagooning.
Hydraulic loading is at a rate of 0.47 gpm/acre. However, it is
reported that only half of the flow percolates into the soil, the
remainder being surface runoff.
Lever (32) has reported the large-scale use of effluent from a
dynamite plant in South Africa for irrigation of 2,000 acres. The
feasibility of the project was enhanced by the fertilizer value of the
wastewater, and the cultivation of hay on the land. The waste, at pH 7
and containing 1,270 mg/1 NHg.-N, 540 mg/1 N03-N, and 2,200 mg/1 sulfate,
was similar to complex facility wastes found in this study. Application
is at a rate of 0.21 gpm/acre. This rate was determined on the basis
of a total nitrogen application rate of 500 Ib/acre/year. The hay
produced is harvested and sold.
The use of land application appears practical where suitable soil
and climatic conditions exist. The soil has the inherent ability to be
able to remove materials from the wastewater by both microbial and crop
74
-------
utilization, and by physical adsorption. However, only the biological
processes affect the nitrates since the soils, which are generally
negatively charged, allow the nitrate to pass unimpeded, depending upon
the hydraulic loading rate (18). Limitations include the large land
area required, and the possibility of contamination of ground water.
A second alternative to the use of land application for on-site
wastewater disposal is the use of evaporative ponds. Use of evaporative
ponds was encountered at three plants during the course of this study.
One, a complex facility located in an arid region, utilizes evaporation
for only a small portion of its waste; that resulting from clean-up of
ANFO blending equipment plus NG neutralizer wastewaters. There is no
overflow from the pond; water loss being through a combination of
evaporation and percolation. The remaining two plants utilizing
evaporation are on-site facilities; one located in the northern mid-
west and the second in the central southeast. At the former facility,
all wastewater except sanitary is discharged to a natural basin on the
plant property, at a rate of 4650 gpd in winter and 6150 gpd in summer.
Water loss from the pond is primarily through percolation with some
evaporative loss in summer.
The third plant utilizes an evaporative pond for process wastewater
from water gel explosives manufacture. All other process wastes, in-
cluding non-contact cooling water, are discharged directly. The lagoon,
with a capacity of 7 million gallons, receives wastewater flow at a
rate of 1 gpm. The pond capacity thus represents a 13-year detention
time, assuming no water loss by percolation or evaporation. The
effective use of evaporative ponds depends upon soil conditions as
they influence percolation, and upon climatic conditions as they effect
evaporation. The availability of land for lagooning should represent
no problem in the explosives industry, due to the typically remote
locations and large land areas required to separate the explosives
facilities from neighboring activities.
75
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IX. ACKNOWLEDGEMENTS
The cooperation of E. Martin and D. Becker of the Effluent
Guidelines Division, and personnel of the Regional Offices of the
Environmental Protection Agency and the Internal Revenue Service
greatly assisted the performance of this study.
76
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X. REFERENCES
1. Shreve, R. Norris, Chemical Process Industries, 3rd Edition,
McGraw-Hill Book Co., N0Y.
2. "Active List of Permissible Explosives and Blasting Devices,"
U. S. Bur. Mines, Explosives Div., Report 3910.
3. "Mineral Industry Surveys," U.S. Bur. of Mines, Div. of
Nonmetallic Minerals, July 31, 1973.
4. Kozlorowski, B0, and J. Kucharski, Industrial Waste Disposal,
Pergatnmon Press, N. Y., 1972.
5. "Mineral Industry Surveys," U.S. Bur. of Mines, Div. of
Health and Safety, Nov., 1972.
6. "Mineral Industry Surveys," U.S. Bur. of Mines, Div. of .
Accident Prevention and Health, March, 1969.
7. Zimmerman, R., "Industrial Wastewater Coefficients (SIC) and Water
Management," presented at 28th Purdue Industrial Waste Conference,
West Lafayette, Ind., May 1-3, 1973.
8. Rudolfs, W., Industrial Wastes Their Disposal and Treatment,
Reinhold Pub. Corp., New York, 1953.
9. Patterson, J. W. and R. A. Minear, Wastewater Treatment Technology,
2nd Edition, Publication IIEQ 73-1, Illinois Institute for Environ-
mental Quality, 1973.
10. Wallace, A. T., G. A. Rohlich and J. R. Willemonte, "The Effect of
Inlet Conditions on Oil-Water Separators at SOHIO's Toledo Refinery,"
Proc. 20th Purdue Industrial Waste Conference, 1965.
11. Dickerson, B. W. "Treatment of Powder Plant Wastes," Proc. 6th
Purdue Industrial Waste Conference, 1951.
12. Wendt, T. M. "Biodegradation of Wastes from Nitroglycerine Produc-
tion," Technical Memorandum 2071, Picatinny Arsenal, Dover, N. J.,
1973.
13. Smith, L. L., "Propellant Plant Pollution Abatement," Project Status
Report, Picatinny Arsenal, Dover, N. J., 1973.
14. "Nitrification and Denitrification Facilities," EPA Technology
Transfer Seminar Publication, August, 1973.
77
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15. Button, W. C. and S. A. LaRocca, "Design for Biological Treatment
of Concentrated Ammonia Wastewaters," presented at 46th Ann. Conf.,
Water Poll. Control Fed., Cleveland, Ohio, Oct., 1973.
16. Adams, C. E., D. A. Krenkel and E. C. Bingham, "Investigations
into the Reduction of High Nitrogen Concentrations," Proc. 5th.
International Water Poll. Research Conf., 1970.
17. Bingham, E. C., "Fertilizer Maker Stops Nitrogen," Water and Waste
Engineering, F-4, Nove, 1972.
18. Harris, L. R., "Abatement of High Nitrate Concentrations at
Munitions Plants: A State of the Art Review," Tech. Report 4568,
Picatinny Arsenal, Dover, N. J., 1973.
19. Kaup, E. C., "Design Factors in Reverse Osmosis, "Chemical
Engineering, 80 (8): 47, 1973.
20. Bingham, E. C. and R. C. Chopra, "Unique Closed Cycle Water System
for an Ammonium Nitrate Producer Using Chem-Seps Continuous
Countercurrent Ion Exchange," presented at the International Water
Conference, The Engineers' Society of Western Pennsylvania, 32nd
Annual Meeting, Pittsburgh, Penn., 1971.
21. Eliassen, R. and G. Tchobanoglous, "Removal of Nitrogen and Phos-
phorus from Wastewaters," Envir. Sci. Tech., 3 (6): 538, 1969.
22. "Cleaning our Environment, the Chemical Basis for Action," American
Chemical Society , Washington, D. C., 1969.
23. Spatz, D. D., "Industrial Waste Processing with Reverse Osmosis,"
Osmonics Inc., Minneapolis, Minn., 1971.
24. Roblich, 6. A., "Methods for the Removal of Phosphorus and Nitrogen
from Sewage Plant Effluent," Internat. Jour. Air and Water Poll.,
7:427, 1963.
25. Eliassen, R., B. M. Wyckoff and C. D. Tonkin, "Progress Report-
Reclamation of Re-Usable Water from Sewage," Technical Report 49,
Department of Civil Engineering, Stanford University, 1965.
26. Eliassen, R., "Ion Exchange for Reclamation of Reusable Water
Supplies," presented at the 1965 Conference, AWWA, Portland,
Oregon, 1965.
27. Grinstead, R. R. and K. C. Jones, "Nitrate Removal from Wastewater
by Ion Exchange," U.S. EPA Project No. 17010 FSJ, 1971.
28. Rohm and Haas Company, "Amberlite LA-1," Technical Note No. IE-41058,
1969.
78
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29. Eskelund, 6., "Elimination of Nitrate Wastes," Technical Memorandum
2130, Picatinny Arsenal, Dover, N. J., 1974.
30. Neal, L. 6., "Army Munitions Plants Modernization Program, Pollu-
tion Abatement Review, Final Report," Report No. 96020.007,
Picatinny Arsenal, Dover, N. Je, 1973.
31. Pregun, E., "Elimination of Sulfate Wastes," Technical Memorandum
2130, Picatinny Arsenal, Dover, N. J., 1974
32. Lever, N. A., "Disposal of Nitrogenous Liquid Effluent from
Modderfontein Dynamite Factory," Proc. 21st Purdue Indust. Waste
Conf., 1966.
79.
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XI. APPENDIX
Metric" Conversion Factors
English Unit
Ib.
ton
gal.
MG
Ibs/ton
Ibs/MG
Metric Equivalent
0.454 kg
0.908 kkg
3.785 liters
-3* 3
3.785 x 10 meters
3.785 x 106 liters
3 3
3.785 x 10 meters
0.500 kg/kkg
0.120 mg/1
0.120 x 10"3 kg/m3
80
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SELECTED WATER
RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
I. Report Ho.
4. Title
State-of-the-Art For The Inorganic Chemicals Industry:
Commercial Explosives
7. Autbor(s) James W. Patterson, Ph.D.
Roger A. Minear, Ph.D.
Organisation Department of Environmental Engineering
Illinois Institute of Technology
Chicago, 111. 60616
12. Sponsoring Organisation
thru -003174
in. Project No
1BB036 R/T 21 AZQ 29
il Grant No.
R-800857
13. Type of Repoi t tud
Period Covered
15. Supplementary Notes
Environmental Protection Agency report number, EPA-600/2-7^-00913, March 1975
16. Abstract
A literature and field study of the commercial explosives industry reveals that
on the basis of products manufactured, plant size, and the nature of the waste-
water, the industry may be divided into three segments. One, complex facilities,
are large plants manufacturing a variety of explosives and intermediate products.
The second category is small specialized formulation plants, typically limited to
blending explosives formulations for use in nearby mining activities. The final
category is specialty product facilities, devoted to manufacture of select in-
gredients such as lead azide and other explosives initiators, blasting caps,.
electric matches and similar appurtenance items.
The explosives industry discharges large volumes of wastewater, typically high in
BOD, nitrogen, and solids, frequently at extreme pH, and containing trace to high
quantities of dissolved and particulate explosives products. Although pollution
abatement technology has not been widely implemented within the explosives industry,
there is potential for significant abatement of pollutant discharge by good
housekeeping practice, application of proven treatment technology and under certain
conditions total wastewater containment.
17a. Descriptors
17b. Identifiers
17c. COWRR Field & Group
18. Availaf,ilin-
n
.-«*
Abstractor
*0. SecirityCl ss.
Send To:
WATER RESOURCES SCIENTIFIC INFORMATION CENTER
U.S. DEPARTMENT OF THE INTERIOR
WASHINGTON. D. C. 2O24O
Institution
WRSIC I OS
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