EPA 440/1-75/038-a
GROUP I, PHASE II
Development Document for Interim
Final Effluent Limitations Guidelines
and Proposed New Source
Performance Standards
for the
ELECTROLYTIC FERROALLOYS
Segment of the
FERROALLOY MANUFACTURING
Point Source Category
(NITED STATES ENVIRONMENTAL PROTECTION AGENCY
FEBRUARY 1975
-------
DEVELOPMENT DOCUMENT
for
INTERIM FINAL EFFLUENT LIMITATIONS GUIDELINES
an'd
PROPOSED NEW SOURCE PERFORMANCE STANDARDS
for the
ELECTROLYTIC FERROALLOYS SEGMENT
of the
FERROALLOYS MANUFACTURING
POINT SOURCE CATEGORY
Russell E. Train
Administrator
James L. Agee
Assistant Administrator for
Water and Hazardous Materials
Allen Cywin
Director, Effluent Guidelines Division
Patricia W. Diercks
Project Officer
February, 1975
Effluent Guidelines Division
U.S. Environmental Protection Agency
Washington, D.C.
-------
ABSTRACT
For the purpose of establishing effluent limitations
guidelines and standards of performance for the electrolytic
ferroalloys segment of the ferroalloy industry, the industry
has been categorized on the basis of product produced and
wastewater constituents as follows:
I. Electrolytic Manganese Products
II- Electrolytic Chromium
The effluent limitations to be achieved by July 1, 1977 are
based upon the pollution reduction attainable using those
treatment technologies as presently practiced by the average
of the best plants in these categories, unless present
technology is uniformly inadequate within a category- The
technologies are for the most part based upon the use of
"end-of-pipe" treatment and generally once-«through water
usage-
The effluent limitations to be achieved by July 1, 1983 are
based upon the pollution reduction attainable using those
control and treatment technologies as presently practiced by
the best plant in the category, or readily transferrable
from one industry process to another.
The new source performance standards are based upon the best
available demonstrated control technology, process,
operating methods, or other alternatives which are
applicable to new sources.
Costs are given for the various levels of treatment
identified for each category and for the attainment of the
suggested effluent guidelines and new source performance
standards.
-------
Page Intentionally Blank
-------
CONTENTS
Section Page
I Conclusions 1
II Recommendations 3
III Introduction 7
IV Industry Categorization 15
V Waste Characterization 19
VI Selection of Pollutant Parameters • 27
VII Control and Treatment Technology 3 5
VIII Cost, Energy and Non-Water Quality 43
Aspects
IX Best Practicable Control Technology 51
Currently Available, Guidelines and
Limitations
X Best Available Technology Economically 55
Achievable, Guidelines and Limitations
XI New Source Performance Standards and 59
Pretreatment Standards
XII Acknowledgements 63
XIII References 6 5
XIV Glossary 67
v
-------
FIGURES
NO.
Page
Figure
1
Electrolytic Manganese Flowsheet
10
Figure
2
Electrolytic Chromium Flow Sheet
13
Figure
3
Plant A - Water and Wastewater Systems
21
Figure
4
Plant B - Water and Wastewater Systems
22
Figure
5
Plant C - Water and wastewater Systems
23
Figure
6
* Electrolytic Manganese Products Treatment
System
41
Figure
7
Electrolytic Chromium Treatment System
42
Table 1
Wastewater Treatment Level Costs
44
Figure
8
Cost of Treatment vs. Effluent Reduction
Electrolytic Manganese Products
49
Figure
9
Cost of Treatment vs. Effluent Reduction
Electrolytic Chromium
50
Table 2
Conversion Factors
68
-------
SECTION I
CONCLUSIONS
For the purpose of establishing effluent limitations
guidelines and standards of performance for the electrolytic
processes segment of the ferroalloys industry, the industry
segment has categorized on the basis of product produced and
wastewater constituents. The categories are as follows:
I- Electrolytic Manganese Products
II. Electrolytic Chromium
Other factors, such as age, size of plant, geographic
location and water uses do not justify segmentation of the
industry into any further subcategories for the purpose of
establishing effluent limitations and standards of
performance. Similarities in waste loads and available
treatment and control technologies within the categories
further substantiate this. The guidelines for application
of the effluent limitations and standards of performance to
specific plants take into account the mix of processes and
water uses possible in a single plant which directly
influence the quantitative pollutional load.
1
-------
Page Intentionally Blank
-------
SECTION II
RECOMMENDATIONS
It is recommended that the effluent limitations guidelines
and new source performance standards be adopted as suggested
herein for the electrolytic ferroalloys segment of the
ferroalloy industry. These guidelines and performance
standards have been developed on the basis of an intensive
study of the industry, including plant surveys, and are
believed to be reasonable and attainable from the
standpoints of both engineering and economic feasibility.
The application of these guidelines and performance
standards to specific plants is intended to be on the basis
of a "building block" approach to define the effluent limits
from the plant as a whole, consider, for example, a plant
having processes in one or more categories. The total
effluent limitation for the plant would be determined by
multiplying the allowable unit loads by the total production
rate in each category and adding the loads from each
category. It is recommended that this method of application
of the guidelines and performance standards be used.
The effluent limitations guidelines, i.e., for the best
practicable control technology currently available and for
the best available technology economically achievable, are
intended to be based upon measurements taken at the outlet
of the last wastewater treatment process unit.
The best practicable control technology currently available
for existing point sources is as follows, by category:
I Physical/chemical treatment to remove or destroy
suspended solids and potentially harmful or toxic
pollutants, with recirculation of the strong wastewater
stream from manganese production.
II Physical/chemical treatment to remove or destroy
suspended solids and potentially harmful or toxic
pollutants.
The effluent limitations are based on achieving by July 1,
1977 at least the pollution reduction attainable using these
treatment technologies. The above technologies are
generally based upon the use of end-of-«pipe treatment and
once-through water usage. The 30-day average effluent
limitations corresponding to the best practicable control
technology currently available are as follow, by category,
3
-------
where all quantities are in kilograms per metric ton of
product (pounds per thousand pounds), except for pH.
TSS Mn Cr NH3-N pH
Category I-Mn 3.389 1.356 — 20.334 6.0 - 9.0
Category I-Mn02 0.881 0.352 — 5.2 87 6.0-9.0
Category II 2.638 1.055 0.106 5.276 6.0 - 9.0
The best available technology economically achievable for
existing point sources is as follows, by category:
I Partial recycle of water, with treatment for removal of
suspended solids and potentially harmful or toxic
pollutants by physical/chemical treatment.
II Partial recycle of water, with treatment for removal of
suspended solids and potentially harmful or toxic
pollutants by physical/chemical treatment.
The effluent limitations are based on achieving by July 1,
1983, at least the pollution reduction attainable using
these control and treatment technologies as presently
practiced by the best plant in each category and using
transfer of technology where the best plant in the category
was felt to be insufficient. The 30-day average effluent
limitations corresponding to the best available technology
economically achievable for existing point sources are as
follows, by category, where all quantities are in kilograms
per metric ton of product (pounds per thousand pounds),
except for pH.
TSS Mn Cr NH3-N pH
Category I-Mn 1.695 0.339 3.389 6.0 - 9.0
Category I-Mn02 0.441 0.088 — 0.881 6.0 - 9.0
Category II 1.324 0.265 0.027 2.649 6.0 - 9.0
The new source performance standards are based upon the best
available demons-fcirated control technology, process,
operating methods, or other alternatives which are
applicable to new sources. The best available demonstrated
control technology for new sources is as follows, by
category:
I Limitation of the quantity of wastewater by in-plant
recirculation, mechanical transport of filter residues,
and treatment for removal of suspended solids and
4
-------
potentially harmful or toxic pollutants by
physical/chemical treatment for electrolytic manganese.
For manganese dioxide, same as BATEA.
II Limitation of the quantity of wastewater by in-plant
recirculation, transport of filter residues, and
treatment for removal of suspended solids and
potentially harmful or toxic pollutants by
physical/chemical treatment.
The new source limitations are as follows, by category,
where all quantities except for pH are in kilograms per
metric ton of product (pounds per thousand pounds of
product) :
TSS Mn Cr NH3-N pH
Category I-Mn 0.740 0.148 — 1.481 6.0 - 9.0
Category I-Mn02 0.441 0.088 — 0.881 6.0-9-0
Category II 0.417 0.083 0.008 0.834 6.0 - 9.0
5
-------
Page Intentionally Blank
-------
SECTION III
INTRODUCTION
The Federal Water Pollution Control Act Amendments of 1972
(the "Act") requires the United States Environmental
Protection Agency to establish effluent limitations which
must be achieved by point sources of discharge into the
navigable waters of the United States. Section 301 of the
Act requires the achievement by July 1, 1977, of effluent
limitations which require the application of the "best prac-
ticable control technology currently available," and the
achievement by July 1, 1983, of effluent limitations which
require the application of the "best available technology
economically achievable."
The Administrator is required by Section 304 (b) to
promulgate regulations providing guidelines for the effluent
limitations required to be achieved under Section 301 of the
Act. These regulations are to identify in terms of amounts
of constituents and chemical, physical, and biological
characteristics of pollutants, the degree of effluent
reduction attainable through the application of the best
practicable control technology currently available and best
available technology economically achievable. The
regulations must also specify factors to be taken into
account in identifying the two statutory technology levels
and in determining 4he control measures and practices which
are to be applicable to point sources within given
industrial categories or classes to which the effluent
limitations apply.
In addition to his responsibilities under Section 301 and
304 of the Act, the Administrator is required by Section 306
to promulgate standards of performance for new sources.
These standards are to reflect the greatest degree of
effluent reduction which the Administrator determines to be
achievable through the application of the "best available
demonstrated control technology, processes, operating
methods, or other alternatives, including, where
practicable, a standard permitting no discharge of
pollutants. "
The Office of Water and Hazardous Materials of the
Environmental Protection Agency has been given the
responsibility by the Administrator for the development of
effluent limitation guidelines and new source performance
standards as required by the Act. The Act requires the
guidelines and standards to be developed within very strict
7
-------
deadlines and for a broad range of industries. Effluent
limitations guidelines under Section 301 and 30 4 of the Act
and standards of performance for new sources under Section
306 of the Act will be developed for 27 industrial
categories- Moreover, each of these industrial categories
probably will require further subcategorization in order to
provide standards that are meaningful-
In order to promulgate the required guidelines and
standards, it is first necessary to (a) categorize each
industry; (b) characterize the waste resulting from
discharges within industrial categories and subcategories;
and (c) identify the range of control and treatment
technology within each industrial category and subcategory.
Such technology will then be evaluated in order to determine
what constitutes the "best practicable control technology
currently available," what is the "best available technology
economically achievable" and, for new sources, what is the
"best available demonstrated control technology".
In identifying the technologies to be applied under Section
301, Section 304(b) of the Act requires that the cost of
application of such technologies be considered, as well as
the non-water quality environmental impact (including energy
requirements) resulting from the application of such tech-
nologies. It is imperative that the effluent limitations
and standards to be promulgated by the Administrator be
supported by adequate, verifiable data clhd that there be a
sound rationale for the judgements made. Such data must be
readily identifiable and available and such rationale must
be clearly set forth in the documentation supporting the
regulations.
Electrolytic Processes
Manganese metal and chromium metal are produced
electrolytically by a method developed just before World War
II. Simple ions of the metal contained in an electrolyte
are plated on cathodes by low-voltage direct current to give
free metal atoms. When the buildup on the cathode becomes
sufficient, the plates are withdrawn from the electrolytic
cells and the deposited metal is removed. Manganese dioxide
is plated anodically-
The electrolytic process for producing nearly pure metals is
a largely chemical operation as far as the preparation of
electrolytes is concerned. The source of the feed materials
are ores, ferroalloy slag, or ferroalloys produced in
electric furnaces. The metal deposition is made in a number
8
-------
of cells with multiple plates, connected in parallel
electrical circuits.
Electrolytic Manganese
Manganese may be produced by the electrolysis of an
electrolyte extracted from manganese ore or manganese-
bearing ferroalloy slag. Manganese ores contain close to 50
percent manganese. Slag from an electric furnace producing
ferromanganese normally contains 10 percent manganese but
this percentage can be increased by adjusting the furnace
operating conditions. Both have proven to be suitable raw
materials for the electrolytic process. A flow sheet of the
process for the preparation of electrolytic manganese is
given in Figure 1. The process can be considered primarily
a four-step operation: 1) roasting the ore, 2) leaching the
roasted ore, 3) purifying the leach liquor, and 4)
electrolysis.
(1) Roasting. The ore is roasted to convert the manganese
oxides present to MnO, while the iron is left as Fe304 which
is less soluble than the lower oxides of iron in the
sulfuric acid used for leaching.
(2) Leaching. The ground and roasted ore is leached with
recycled anolyte from the electrolytic cell, which is
principally ammonium sulfate with some sulfuric acid and
manganous sulfate. The concentration of the leach is
adjusted by addition of ammonium sulfate and sulfuric acid.
Overall extraction of manganese from the roasted ore is 98-
99 percent. On neutralization, iron and aluminum hydroxides
are precipitated and take down with them most of the
molybdenum, arsenic and silica. The solution is then
clarified and filtered.
(3) Purifying the leach liquor. The neutral leach liquor
contains some iron, arsenic, copper, zinc, lead, nickel,
cobalt and molybdenum, which must be removed before
electrolysis. Removal is accomplished by treatment with
hydrogen sulphide gas or ammonium sulphide and filtration of
the liquor to remove the sulphides. A small amount of
manganese is lost in this step.
{4) Electrolysis. The purified solution for electrolysis
enters the cathode compartment, where manganese is plated on
the cathode, flows through the diaphragm into the anode
compartment from which it is discharged. It may then be
recycled for leaching of the ore or slag.
9
-------
Figure 1.
ELECTROLYTIC MANGANESE FLOWSHEET
ANOLYTE
OVERFLOW #-
ORE SHED
I
DRYER
STORAGE BIN
k
GRINDERS
STORAGE TANK
REDUCING FURNACE
+ :
LEACHING TANK
COOLING TOWER
~r~
Mg SALTS
O
2T
<
ANOLYTE
FILTRATE
»1
CATHOLYTE STORAGE
I ~
FILTER
PURIFIED CATHOLYTE
4
ELECTROLYSIS CELLS
+ =
MANGANESE METAL
CLARlFIE R
» UNDFRFI OW
REPULPING TANK
«
MOORE FILTER
*
SOLIDS
TO
OLIVER FILTER
WASTE
SULFIDES
MUD TO WASTE
10
-------
Manganese Dioxide
One process for the production of manganese dioxide is the
roasting of pyrolusite ore. It may also be prepared
synthetically by electrolysis of manganese sulfate in a
sulfuric acid solution. Only the latter method will be
considered further herein.
The ore is crushed, ground, mixed with Bunker ' C* oil and
roasted, which converts higher oxides to soluble MnO. In a
leaching tank, spent electrolyte solution and make-up
sulfuric acid leach the roasted ore. Insoluble sludge
separates out from the leach solution on filters. The crude
leach solution is next treated with barium sulfide to remove
cobalt and nickel impurities as insoluble sulfides. CaO is
added for neutralization and the sulfide sludge is removed.
Part of the sludge recycles back to the sulfide treatment
tank to recover any manganese that may have precipitated
with the impurities. Iron is removed (along with sulfur,
arsenic, and organics) by air oxidation and the iron sludge
is filtered out. The filtrate is used as the feed solution
for the electrolytic cells.
MnO2 deposits on anodes in the electrolytic cells, and after
separation from the anodes, the Mn02 is ground and the fine
material is washed in a thickening tank, filtered and dried.
The manganese dioxide is then ready for packing and
shipment.
Electrolytic Chromium
The most readily available and cheapest source for
electrolytic chromium, free from many extraneous elements,
is high carbon ferrochromium produced in the electric
furnace. .This alloy is readily soluble in sulfuric acid.
Ferrochromium is fed to a leach tank where it is dissolved
in a mixture of reduced anolyte, chromium alum mother liquor
and make-up sulfuric acid. During the reaction a large
volume of hydrogen is liberated and a ventilating system,
necessary to maintain hydrogen concentration below explosive
limits, exhausts the gases to a scrubber.
After leaching, the slurry is fed into a holding tank where
cold mother liquor, coming from the ferrous ammonium sulfate
crystallization, is added to cool the batch. Undissolved
solids are separated from the solution and this residue is
washed with water and discarded. The solution resulting
from washing the leach residue is used to dissolve the crude
11
-------
iron sulfate. Ammonium sulfate is added to this solution
and ferrous ammonium sulfate crystals then separated on a
vacuum filter and dried in a rotary drier. This can be sold
as a fertilizer for its ammonia content. The filtrate is
advanced to a conditioning tank, where the chromium is
converted to the non-alum-forming modification by holding at
elevated temperatures for several hours. The conditioned
liquor is then pumped into a crystallizer and the
temperature is reduced. Crude iron sulfate crystals which
are formed during this cooling period are separated from the
mother liquor on a vacuum filter.
The conditioned liquor is clarified and sent to the aging
circuit. About 80 percent of the chromium is stripped as
alum from the aging circuit. The crystal slurry is filtered
and washed; the filtrate is pumped to the leach circuit and
the washed chromium-alum crystals are dissolved in hot water
to produce cell feed. Cell feed is supplied continuously to
the operating cells where it is mixed with a stream of
circulating catholyte. Excess catholyte is withdrawn from
the circulating stream and pumped back into the aging
circuit. Anolyte is treated with sulfur dioxide to reduce
the chromic acid to trivalent chromium and then returned to
the start of the ferrochromium leaching circuit. The
electrolytic cells are covered and are strongly ventilated
to reduce the ambient hydrogen and hexavalent chromium
concentrations in the cell room.
Cathodes are withdrawn from the cells periodically and the
plated metal is stripped, crushed and washed with hot water
in a classifier to remove soluble salts.
The process flow diagram for the production of electrolytic
chromium is shown in Figure 2.
12
-------
F«944 CEILS EACH
CATHOLYTE SOLUTION
DIVALENT CXOMM4, AMhjQNIUM SULFATE
SLICEOUS
RESIDUE
VACUUM
CRYSTALLIZER
FILTER
LINE I
CRU06
IRON
SULFATE
AMMONIUM
CHROME
ALUM CRYSTALS
W4Cf(SOi)2' ^
I l?H?Q
ANOLYTE TO
LEACHING «-
TANK
CATHOOES
FROM CELLS
LEACH
TANK
COOLING
TANK
LEACHING
CATHOOC
CLEANNG I
STRIPPING
\TTT7 \\\\
SETTLERS Y
FOR AGING 1 »
& CRYSTALLIZATION
I Hill PURE AMMONIUM
OSSOLVER FILTER O*0ME ALUM
SOLUTION
HORIZONTAL
FILTER
CRUDE IRON
SULFATE
CRYSTALS
SIURPY
CHROMUM
[deposit
0.0
,20~3_i<
MOTHER
LIQUOR
AMMONIUM I CHROMIUM SULFATES MOTHER LIQUOR
Bl EEO
FILTRATE
OISCARO
•VACUUM
•SOOfUM
CARBONATE
SOLOS
BASIC
CHROME
SULFATES
MOTHER LIQUOR TO
^COOLING TOWER
FERROUS
'AMMONIUM
SULFATE
CRYSTALLIZER
DMUM FILTER
-------
Page Intentionally Blank
-------
SECTION IV
INDUSTRY CATEGORIZATION
The purpose of the effluent limitations can be realized only
by categorizing the industry into the minimum number of
groups for which separate effluent limitations and new
source performance standards are reasonably required and
must be developed* The categorization here is believed to
be that minimum, i.e. , the least number of groups having
significantly different water pollution potentials and
treatment problems- The categorization is as follows:
I. Electrolytic manganese products
II. Electrolytic chromium
In developing this categorization, consideration was given
to the following factors as possibly providing bases for
categorization:
1. Raw Materials
2. Product Produced
3. Size and Age of Facilities
1« Waste water constituents
5. Treatability of Wastes
6. Production processes
7. Water Uses
Raw Materials
The raw materials used for electrolytic ferroalloys
production may be either ores, ferroalloys or slag from
electric furnace production of ferroalloys- The type of raw
material used, of course, varies with the type of end
product desired. High carbon ferrochromium is used
exclusively for electrolytic chromium, while electrolytic
manganese might be made with either manganese ore or slag
from the production of ferromanganese. Manganese dioxide is
made from manganese-bearing ore, exclusively.
Differentiation on the basis of raw materials as between
products is to some extent inherent in the chosen
categorization, but is only a very secondary basis-
Product Produced
Product groupings were judged to provide the best basis for
categorization, primarily because waste water constituents
vary by product. Although manganese is found to some extent
15
-------
in -the wastewater from chromium production, no (or
miniscule) quantities of chromium are found in manganese
production wastewaters. Additionally, the weak wastewater
stream from manganese production bears a marked degree of
similarity to the wastewater stream from manganese dioxide
manufacture.
Size and .Age of Facilities
Size and age of facilities do not appear to provide any
basis for categorization. These processes are essentially
modular in nature, and the manganese plants, in particular,
are all approximately equal in size. Plant ages will, of
course, affect the ease with which changes can be made in
processing and treatment systems and will affect the costs
of implementation, since the newer plants have taken more
pains to recycle waters within the plant and reduce effluent
volumes. To some extent, this is an economy measure, as the
price of the raw materials have increased markedly in the
past few years. An increase in raw material costs makes
recirculation more attractive, particularly when 10 to 20%
of the metal value in the raw material is being lost in the
discharge. However, although the newer plants will incur
lower costs to meet the guidelines than will the older
plants, the total cost for pollution control for all plants
will not be that disparate, since the newer plants have
already spent substantial sums.
Waste water Constituents
Wastewater constituents and water usage rates provide the
most important bases for categorization. Suspended solids
is a common problem, although the quantity does differ
somewhat with product. Ammonia is found in the highest
concentrations in wastewaters from manganese and chromium
production, although enough is present in manganese dioxide
wastewaters to warrant limitations. Manganese is found in
the highest concentrations in wastes from manganese and
manganese dioxide production, but again, enough is found in
wastewaters from chromium production to warrant limitation*
Chromium, however, is only found in appreciable quantities
in chromium production wastewaters—only trace amounts being
present in manganese dioxide and manganese wastes. For
these reasons, the categorization of this industry by
product grouping was felt to be the most rational approach.
Treatability of Wastes
The wastes produced from the various processes may be
treated by essentially similar methods and no separate basis
16
-------
for categorization is found here. -Of course, chromium
producers have available to them the option of crystallizing
ferrous ammonium sulfate, and thereby reducing the quantity
of ammonia to be treated, which is not available to
manganese and manganese dioxide producers. However, this
slight difference is not sufficient to warrant separate
categorization, but is instead a corollary reason for the
subcategorization based on product groupings.
Production Processes
The production processes are fairly similar within this ^
segment. The process generally consists of leaching the
metal from either ore or ferroalloys, various purification
steps, and electrolytic deposition. Generally, there are
more similarities than differences between the processes.
There are some slight differences, however. The processes
for production of chromium and manganese use ammonia as an
integral part of the process, while that for manganese
dioxide does not. Chromium and manganese are plated
anodically, while manganese dioxide is plated cathodically.
While there are these and other small differences, the end
result, the wastewater, is more amenable to differentiation
on the basis of product groupings and wastewater
constituents than of production process.
Rationale for the Segmentation of the Ferroalloys Industry
During the previous year the ferroalloys industry was
categorized and limitations established for the open
electric furnaces with wet air pollution control devices
subcategory, the covered electric furnaces with wet air
pollution control devices subcategory and the slag
processing subcategory. The categories as proposed herein
cannot be made to conform with the established categories
for several reasons.
One of those is the differing water usage rates—the
electrolytic segment consumes, generally, several times as
much water as does the smelting segment. Although some of
the constituents, such as suspended solids, manganese and
chromium are common to both segments, cyanide and phenol are
found only in the wastes from the electric furnace smelting
operations, while ammonia was found only in electrolytic
wastes. Additionally, water is used as an integral part of
the process in the electrolytic segment, as well as for non-
contact cooling. The only water uses in the smelting
segment are for gas cleaning and non-contact cooling.
17
-------
Page Intentionally Blank
-------
SECTION V
WASTE CHARACTERIZATION
Water is used extensively in the electrolytic ferroalloys
industry — for preparing the electrolyte, washing the
plated metal, filter residue transport, non-contact cooling,
etc.
Electrolytic Manganese
There are three plants presently producing electrolytic
manganese. Plant A began producing manganese about 20 years
ago. Plant B about 6 years ago, and Plant C about 10 years
ago. All are approximately equal in size at about 9000 kkg
(10,000 tons) annual production. Both of the older plants
hydraullically transport filter residues from the
electrolyte preparation processes to tailings ponds. Plant
B collects and hauls the filter muds. Plants B and C use
ore as their feedstock, while Plant A uses slag produced
during the smelting of ferromanganese in electric furnaces.
In the electrolytic manganese industry, the waste waters may
be classed as either "strong" or "weak." The "strong"
wastewaters contain some electrolyte and may also carry
filter residues from electrolyte preparation. As a result,
they may contain several thousand mg/1 of suspended solids,
manganese, ammonia and sulfate.
The "weak" wastewaters, however, result primarily from
washdowns and other miscellaneous uses. compared to the
strong wastewaters, they are very much lower in
concentration. A comparison of the strong and weak
wastewaters is found below for Plants A and B.
Strong Wastewater
Plant A
Plant B
Weak Wastewater
Plant A
Plant B
mg/1
mg/1
mg/1
mg/1
Suspended Solids
55,300
85
144
9
Manganese
6,700
1,061
128
21.7
Ammonia-N
4,208
3,733
148
16
Sulfate
35,524
7,100
900
73
pH
7.3
2.7
5.1
7.3
Flow (gal/ton)
3820
6000
32,500
6400
The raw waste loads
: for these
plants
are as
follows,
kg/kkg (lb/1000 lb)
in
19
-------
Plant A
'Strong' 'Weak* Total
Plant B
'Strong * 'Weak' Total
Parameter
Suspended
Manganese
Ammonia-N
Sulfate
Solids 881.1 19.5 900.6 2.13 .24 2.37
106.8 17.4 124.2 26.55 .58 27.13
67.0 20.1 87.1 93.42 .43 93.83
566.0 122.0 688.0 177.68 1.95 179.63
Waste water treatment at all three plants depends highly on
lagoons. Plant A discharges the strong manganese wastes
with a lime slurry for neutralization into a large 30 ha (70
ac) settling lagoon. The weak wastewater, after mixing with
other plant wastewaters, is also discharged into this
lagoon.
Plant B discharges the strong wastewater to a large pond,
where after settling and evaporation by sprays, the
wastewater is recycled to the plant for use as primary
washwater and other miscellaneous uses. The weak
wastewaters are usually discharged directly to a stream,
although a dissolved solids monitor may divert the discharge
to the evaporation pond, should the dissolved solids level
exceed a preset limit.
Plant C diverts their weak wastewaters into a pond. These
consist mostly of washwaters from the manganese production.
Prior to the pond, they are mixed with wastes from the
production of other materials at the plant. The strong
wastewaters (also mixed with other plant wastes) flow to
another tailings pond, where after some aeration, they enter
an oxidation pond, after which they join the weak wastewater
mixture and are discharged.
Figures 3, 4 and 5 show the wastewater flow diagrams at
Plant A, B and C.
20
-------
F/y ure. 3
Plan "f~ A
v/«fer a» of Wa ifewttfer S yst'e.m s
m
\> 1'
E It.c.'h-oly't'c-
O b r-of~> < t"vl
E-le-cfrolyt-'c.
a «4it
, Outf*ll
-------
f=r
3°
/?#a/ £iV«.r*
vv* rer
Scr<^i»M9.
Ohltrfn OL^tCftf
tt>
a net F»
WAitr-
Plant &
Wafer and Ujasfe wafer Sys+"«Ai*
Ro4s1?n<
Is)
ts)
Cod I'"
T*w«
7~<•'*
i if "
I 10
l\.«.e« very
Oi*t.r*,t'i#n5
ir2_ 5f^y, np"',,
K v~/ |
~\ O O O /—
fe.y./.y e"pr'f-
S tjf& rn*Tl*
ProJue^
-------
riant a
"Wa,Te.r a.nd UjcLst'&it/at'cr Syji~ems
OHe
-------
Manganese Dioxide
The raw waste from the production of manganese dioxide at
Plant A is as follows: .
Concentration Raw Waste Load
(mg/1) kg/kkg (lb/1000 lb)
Suspended Solids 22,505 770.5
Manganese 3,158 108-3
Ammonia-N 75 2.7
pH (units) 4. 1
Flow (gal/ton) 8207
Treatment of the wastewater is identical to that for the
strong wastewaters from electrolytic manganese production at
Plant A. This facility was installed about seven years ago.
Electrolytic Chromium
Plant A produces this commodity, as does Plant D. Plant Afs
chromium facility was constructed about 20 years ago, while
Plant D started operation in early 1974. The raw waste from
chromium production at Plant A is as follows:
Suspended Solids
Chromium
Iron
Manganese
Ammonia-N
pH (units)
Flow (gal/ton)
Concentration
(mg/1)
290
1764
4492
52
1076
2.9
Raw Waste Load
kg/kkg (lb/1000 lb)
30.5
186.1
473P 8
5.5
113.5
25,285
Plant A crystallizes and sells ferrous ammonium sulfate to a
fertilizer company. During the times that the FAS cannot be
sold, it is not crystallized and becomes part of the raw
waste. The data reported above reflect the latter
condition. Treatment at Plant A for this waste stream is
identical to that for ithe weak electrolytic manganese
wastewater.
The conventional process at Plant D is altered in that the
solution from the leach filter goes first to the aging and
crystallizing settlers through a cooler then to the steam
conditioning tank and thence through the remainder of the
process; additionally, some of the mother liquor from the
horizontal filter can be returned to the steam conditioning
24
-------
tank or to the leaching tank. This modification reportedly
produces a better, drier crude ferrous ammonium sulfate
which can be used as-is. Residue from the leach filter is
trucked to storage as a damp sludge, condensate from the
vacuum crystallizer is re-used, ammonium sulfate is sold or
given away in the crude without recrystallization, and the
filter effluents are minimal. The waste water effluent from
Plant D was expected to be .06 1/sec or less (1 gpm or less)
due mainly to spills and washups. All such waste waters
must be pumped from the plant sumps. Treatment is lime
neutralization followed by 3 settling basins in series. The
batch discharge is slightly larger than expected and is
equivalent to 6245 1/kkg (1500 gal/ton) of product. Plant C
reports only one batch discharge during the period from mid-
March to mid-June of this year. Additionally, it is
estimated that a thousand gallons per day was lost by solar
evaporation. It is hoped that experimental work by a
fertilizer company will result in the crude ferrous ammonium
sulfate being salable as a micro-nutrient for plants at $15
- $20 per kkg. This material is reported to be an excellent
fertilizer for roses, rhododendrons and azaleas. However,
due to the relatively small amount produced, the plant feels
that independent marketing would be very difficult and and
expensive.
Treated Wastes
Because the electrolytic wastes at Plant A and C are
extensively commingled with other plant wastes, no absolute
value for the treated wastes at these plants can be given.
Analytical data for the lagoon discharge at Plant A are as
follows, in mg/1:
Suspended solids 15
Manganese 91
Chromium 0.08
pH 7.2
The treated discharge at Plant B is simply the discharge
the weak wastewater, as shown below.
of
Parameter
Concentration
(mg/1)
Waste Load
(kg/kkg)
(lb/10 00 lb)
Suspended Solids
Manganese
Ammonia-N
pH
9
21.
16
7.3
0.24
0. 58
0.43
25
-------
Page Intentionally Blank
f
-------
SECTION VI
SELECTION OF POLLUTION PARAMETERS
Pollutant parameters have been selected by industry
categories on the basis of those which originate in the
production processes in significant amounts and for which
control and treatment technologies are reasonably available.
The parameters for each category have also been selected so
as to be the minimum number which will insure control. The
pollutant parameters selected are as follows:
Suspended Solids
pH
Chromium (for electrolytic chromium only)
Manganese
Ammonia-N
Flow, of course, is basic in that its magnitude indicates
the degree of recirculation and reuse practiced and the
degree to which water conservation is utilized. Although
effluent flow volumes are not specified in the recommended
guidelines, its measurement and control is implicit in
attaining the pollutant effluent loads specified.
Wastewater Constituents and Parameters of Pollutional
Significance
The wastewater constituents of significance for the
electrolytic segment of the ferroalloys industry include
suspended solids, manganese, chromium, ammonia and pH. All
other metals and chemical compounds in the wastewater that
are not the subject of effluent limitations but which would
normally be precipitated during treatment for removal of
manganese or chromium are considered part of the suspended
solids as well as any chemical or biological material
adsorbed or entrapped by the suspended solids during
clarification and separation. Thus, suspended solids are a
wastewater constituent of pollutional significance.
pH is subject to effluent limitations because it indicates
that excessive free acidity or alkalinity has been
neutralized.
Chromium and manganese are the principal metals originating
in the production processes. Hexavalent chromium is not
included because the economics of the electrolytic chromium
27
-------
process require the reduction of hexavalent chromium as an
integral part of the process. Ammonia is included because
of the very high concentrations found in the raw waste
streams.
Thus, the major chemical, physical, and biological
wastewater constituents and parameters of pollutional
significance are as follows:
Ammonia
Chromium, total
Manganese
Suspended solids
PH
Other wastewater constituents of secondary importance in
the industry that are not the subject of effluent
limitations or standards of performance are as follows:
Iron
Aluminum
Total dissolved solids
Chemical oxygen demand
Turbidity
Color
Temperature
Rationale for the Selection of Pollutant Parameters
Total Suspended Solids
Suspended solids include both organic and inorganic
materials. The inorganic components include sand, silt, and
clay. The organic fraction includes such materials as
grease, oil, tar, animal and vegetable fats, various fibers,
sawdust, hair, and various materials from sewers. These
solids may settle out rapidly and bottom deposits are often
a mixture of both organic and inorganic solids. They
adversely affect fisheries by covering the bottom of the
stream or lake with a blanket of material that destroys the
fish-food bottom fauna or the spawning ground of fish.
In raw water sources for domestic use, state and regional
agencies generally specify that suspended solids in streams
shall not be present in sufficient concentration to be
objectionable or to interfere with normal treatment
processes. Suspended solids in water may interfere with
many industrial processes, and cause foaming in boilers, or
encrustations on equipment exposed to water, especially as
the temperature rises. Suspended solids are undesirable in
28
-------
water for textile industries; paper and pulp; beverages;
dairy products; laundries; dyeing; photography; cooling'
systems, and power plants. Suspended particles also serve
as a transport mechanism for pesticides and other substances
which are readily sorbed into or onto clay particles.
Solids may be suspended in water for a time, and then settle
to the bed of the stream or lake. Those settleable solids
discharged with man's wastes may be inert, slowly
biodegradable materials, or rapidly decomposable substances.
While in suspension, they increase the turbidity of the
water, reduce light penetration and impair the
photosynthetic activity of aquatic plants.
Solids in suspension are aesthetically displeasing. When
they settle to form sludge deposits on the stream or lake
bed, they are often much more damaging to the life in water,
and they retain the capacity to displease the senses.
Solids, when transformed to sludge deposits, may do a
variety of damaging things, including blanketing the stream
or lake bed and thereby destroying the living spaces for
those benthic organisms that would otherwise occupy the
habitat.
Turbidity is principally a measure of the light absorbing
properties of suspended solids. It is frequently used as a
substitute method of quickly estimating the total suspended
solids when the concentration is relatively low.
El
The term pH is a logarithmic expression of the concentration
of hydrogen ions. At a pH of 7, the hydrogen and hydroxyl
ion concentrations are essentially equal and the water is
neutral. Lower pH values indicate acidity while higher
values indicate alkalinity. The relationship between pH and
acidity or alkalinity is not necessarily linear or direct.
Waters with a pH below 6.0 are corrosive to water works
structures, distribution lines, and household plumbing
fixtures and can thus add such constituents to drinking
water as iron, copper, zinc, cadmium and lead. The hydrogen
ion concentration can affect the "taste" of the water. At a
low pH water tastes "sour". The bactericidal effect of
chlorine is weakened as the pH increases, and it is
advantageous to keep the pH close to 7. This is very
significant for providing safe drinking water.
Extremes of pH or rapid pH changes can exert stress
conditions or kill aquatic life outright. Dead fish.
29
-------
associated algal blooms, and foul stenches are aesthetic
liabilities of any waterway- Even moderate changes from
"acceptable" criteria limits of pH are deleterious to some
species. The relative toxicity to aquatic life of many
materials is increased by changes in the water pH.
Metallocyanide complexes can increase a thousand-fold in
toxicity with a drop of 1.5 pH units. The availability of
many nutrient substances varies with the alkalinity and
acidity. Ammonia is more lethal with a higher pH.
The lacrimal fluid of the human eye has a pH of
approximately 7.0 and a deviation of 0,1 pH unit from the
norm may result in eye irritation for the swimmer.
Appreciable irritation will cause severe pain.
Chromium
Chromium, in its various valence states, is hazardous to
man. It can produce lung tumors when inhaled and induces
skin sensitizations. Large doses of chromates have
corrosive effects on the intestinal tract and can cause
inflammation of the kidneys. Levels of chromate ions that
have no effect on man appear to be so low as to prohibit
determination to date.
The toxicity of chromium salts toward aquatic life varies
widely with the species, temperature, pH, valence of the
chromium, and synergistic or antagonistic effects,
especially that of hardness. Fish are relatively tolerant
of chromium salts, but fish food organisms and other lower
forms of aquatic life are extremely sensitive. Chromium
also inhibits the growth of algae.
In some agricultural crops, chromium can cause reduced
growth or death of the crop. Adverse effects of low
concentrations of chromium on corn, tobacco and sugar beets
have been documented*
Manganese
The presence of manganese may interfere with water usage,
since manganese stains materials, especially when the pH is
raised as in laundering, scouring, or other washing
operations. These stains, if not masked by iron, may be
dirty brown, gray or black in color and usually occur in
spots and streaks. Waters containing manganous bicarbonate
cannot be used in the textile industries, in dyeing,
tanning, laundering, or in hosts of other industrial uses.
In the pulp and paper industry, waters containing above 0.05
ppm manganese cannot be tolerated except for low-grade
30
-------
products. Very small amounts of manganese—0.2 to 0.3 ppm—
may form heavy encrustations in piping, while even smaller
amounts may form noticeable black deposits.
Ammonia
Ammonia is a common product of the decomposition of organic
matter. Dead and decaying animals and plants along with
human and animal body wastes account for much of the ammonia
entering the aquatic ecosystem. Ammonia exists in its non-
ionized form only at higher pH levels and is the most toxic
in this state. The lower the pH, the more ionized ammonia
is formed and its toxicity decreases. Ammonia, in the
presence of dissolved oxygen, is converted to nitrate (N03)
by nitrifying bacteria. Nitrite (N02), which is an
intermediate product between ammonia and nitrate, sometimes
occurs in quantity when depressed oxygen conditions permit.
Ammonia can exist in several other chemical combinations
including ammonium chloride and other salts.
Nitrates are considered to be among the poisonous
ingredients of mineralized waters, with potassium nitrate
being more poisonous than sodium nitrate. Excess nitrates
cause irritation of the mucous linings of the
gastrointestinal tract and the bladder; the symptoms are
diarrhea and diuresis, and drinking one liter of water
containing 500 mg/1 of nitrate can cause such symptoms.
Infant methemoglobinemia, a disease characterized by certain
specific blood changes and cyanosis, may be caused by high
nitrate concentrations in the water used for preparing
feeding formulae. While it is still impossible to state
precise concentration limits, it has been widely recommended
that water containing more than 10 mg/1 of nitrate nitrogen
(N03-N) should not be used for infants. Nitrates are also
harmful in fermentation processes and can cause disagreeable
tastes in beer. In most natural water the pH range is such
that ammonium ions (NH4+) predominate. In alkaline waters,
however, high concentrations of un-ionized ammonia in
undissociated ammonium hydroxide increase the toxicity of
ammonia solutions. In streams polluted with sewage, up to
one half of the nitrogen in the sewage may be in the form of
free ammonia, and sewage may carry up to 35 mg/1 of total
nitrogen. It has been shown that at a level of 1.0 mg/1 un-
ionized ammonia, the ability of hemoglobin to combine with
oxygen is impaired and fish may suffocate. Evidence
indicates that ammonia exerts a considerable toxic effect on
all aquatic life within a range of less than 1.0 mg/1 to 25
mg/1, depending on the pH and dissolved oxygen level
present.
31
-------
Ammonia can add to the problem of eutrophication by
supplying nitrogen through its breakdown products. Some
lakes in warmer climates, and others -that are aging quickly
are sometimes limited by the nitrogen available. Any
increase will speed up the plant growth and decay process.
Rationale for Rejection of Other Wastewater Constituents as
Pollutants
Metals
The rationale for rejection of any metal other than
manganese or chromium as a pollutant parameter is based on
one or more of the following reasons:
(1) They would not be expected to be present in
electrolytic wastes in significant amounts (e.g.,
uranium, mercury, arsenic), or
(2) They will be removed simultaneously by
coprecipitation and clarification along with chromium
and/or manganese (e.g., iron), or
(3) Insufficient data exists upon which to base effluent
limitations and standards of performance.
Dissolved Solids
Dissolved solids do not constitute an important parameter
indicative of pollution when associated heavy metals are
also the subject of effluent limitations. Although the
concentration of total dissolved solids will become higher
as efforts are directed to reducing water use and volume of
effluent discharged, the total quantity of dissolved solids
will remain unchanged.
Turbidity
Turbidity is indirectly measured and controlled
independently by the limitation on suspended solids.
Color
Color is not usually significant in wastewater from
ferroalloys and is indirectly controlled by the effluent
limitations on suspended solids and on total metal which
controls the amount of colloidal metal that could color the
effluent.
32
-------
Temperature
Temperature is not considered a significant pollution
parameter in the ferroalloys industry. However, cooling
water used to cool the cells may contain pollutants from
leaks in the system. Insufficient data exists upon which to
base effluent limitations and standards of performance.
33
-------
Page Intentionally Blank
r
-------
SECTION VII
CONTROL AND TREATMENT TECHNOLOGY
Of the various control and treatment technologies available,
recirculation and reuse of water is the"generally most
applicable and singly most effective method of reducing or
eliminating the discharge of pollutants. So long as any
required blowdown discharge is treated to the same effluent
concentration as once-through water, it is obvious that the
load reduction for each contaminant will be in direct
proportion to the percentage of water recirculated- The
only restrictions on the applicability of such technology
are the water qualities required for particular uses
(including dissolved solids buildup due to evaporation) and,
of course, the costs involved. Water quality restrictions
can generally be handled by using fresh makeup water at the
points requiring highest quality water.
SUSPENDED SOLIDS
¦ — — ¦¦ ^ i !¦, ¦¦ ¦¦ i
Suspended solids can be removed by plain sedimentation,
flocculation-clarification, and filtration. Plain
sedimentation in lagoons, basins, or clarifiers of
sufficient sizes in relation to the hydraulic load will
reduce suspended solids to 50-100 mg/1 depending upon
particle size, the lower concentrations being typical for
coarse solids and the higher for finer solid particles.
Lagoons are less expensive than clarifiers in capital and
operating costs, but require much more land area. Plant A
adds a flyash slurry from a captive power plant to the large
settling lagoon and sampling indicated that this resulted in
an average effluent suspended solids level of 15 mg/1.
Flocculator-clarifiers, i.e., the use of chemical coagulants
and/or polyelectrolytes followed by clarification will
produce effluents with suspended solids concentrations of 25
mg/1 on the average but may occasionally exceed 45 mg/1 at
times. Rapid sand filters will regularly produce effluents
with suspended solids concentrations of 15 mg/1 and often of
10 mg/1 or less. However, sand filters may require some
pretreatment to decrease the suspended solids loading, since
otherwise excessively frequent back-washing would be
required.
35
-------
ACID SOLUTIONS AND METALLIC SALTS
7
Manganese, chromium and iron, to the extent they are present
as dissolved salts, are removed by neutralization, at a pH
above 9.5 for manganese, and at about 8 for chromium and
iron. This is followed by precipitation and sedimentation.
Polyelectrolytes are usually used to promote sedimentation.
Sufficiently high pH, adequate sedimentation and oxidation
is required for low effluent concentrations. Manganese
removal is also assisted by the addition of chlorine.
Chromium is significantly soluble above and below the
optimum pH of 8.0, while the pH for the optimum
precipitation of manganese is 9.5 or higher. After the
metals are precipitated and the solution is clarified, the
pH of the wastewater should be made acceptable for discharge
by neutralization if necessary-
Optimum precipitation of the metal ions depends primarily on
pH and the valence states. The valence state is of
particular importance for chromium; it precipitates more
readily when reduced to trivalent chromium.
Other methods for removal of manganese are found in the
literature, but are probably unfeasible for treatment of
wastewaters containing several thousand ppm. For example,
the manganese zeolite process, wherein water is passed
through a manganese zeolite bed, which acts as an oxidizing
contact medium and as a filter medium, is used for potable
water treatment. At a flow rate and manganese concentration
comparable to those at Plant A, about 63,000 ft3 of
manganese zeolite would be required if a 24 hour period were
desired between regenerations. Additionally, 5000 kg
(11,000 lb) per day of potassium permanganate would be
consumed.
Ammonia
Ammonia can be removed from waste waters by either
biological or physical/chemical treatment.
Biological treatment by activated sludge can reduce ammonia
concentrations to less than 5 mg/1. Ammonia is oxidized to
N03 in aerobic treatment and the nitrate broken down to
nitrogen and oxygen in anaerobic treatment. A study done on
the biological treatment of ammonia liquors from cokemaking
operations, which are comparable in concentration to those
from electrolytic plants, indicated that this system is
effective, but the costs when scaled to the volumes, at
electrolytic plants are high.
36
-------
Physical/chemical treatment, may involve either removal of
ammonia from wastes by stripping or oxidation by breakpoint
chlorination. Breakpoint chlorination requires at least 2.0
moles of chlorine per mole of ammonia. Ammonia is first
converted to chloramines. Then the chlorine will oxidize
the chlorinated compound and the ammonia will be oxidized to
nitrogen and hydrogen. After this point, there will begin
to be a free chlorine residual — hence the name 'breakpoint
chlorination.«
Air stripping, i.e., using air to remove the ammonia, is
employed for municipal wastes. However, influent ammonia
concentrations of demonstrated systems were substantially
lower than electrolytic wastewaters. Additionally, this
technique may result in air quality deterioration.
Steam stripping, commonly used in both the steel and
fertilizer^ industries for removal of ammonia from wastes,
may offer the greatest hope for recovery of costs and of a
useful material as an ammonia treatment method for the
electrolytic ferroalloys industry. It has been used for
treating wastes of high concentrations and generally
involves liming to cause the fixed ammonia in the wastes to
convert to free ammonia and distillation to remove the
ammonia. commonly, the ammonia is then converted to
ammonium sulfate by treating with dilute sulfuric acid.
Stripping can recover ammonia either in the aqueous or
anhydrous forms, both of which might be reusable in the
electrolytic processes. However, the large'operating costs
associated with the process are only partially offset by the
savings realized by reduced purchases of ammonia for the
process.
Ion exchange is used in the fertilizer industry for removal
of ammonium nitrate from wastewater and regenerating it from
the resins. It may also be applicable to ferroalloys.
However, this is a fairly complicated system requiring two
operators per shift (at a flow of 100 0 gpm) . Increased
labor costs alone, therefore, appear to make this option
economically impractical at this time.
Ammonia can be removed from electrolytic chromium
wastewaters by crystallization of the ferrous ammonium
sulfate. This is more or less uniformly employed by
electrolytic chromium producers who sell or give away the
product, thereby removing ammonia from the water to be
discharged. The ammonium sulfate in the wastewater from
electrolytic manganese production might also be removed from
wastewater by crystallization, but it may be necessary to
concentrate the wastewater stream in order to remove it.
37
-------
This could be accomplished by segregating the relatively
small quantity of concentrated waste which is dumped, or by
evaporation or reverse osmosis. The resultant ammonium
sulfate may be recyclable to the process.
The treatment processes discussed here are largely
conventional. The main problem in this industry appears to
be the reduction of waste water volumes requiring treatment
to a minimum, design of adequately sized facilities
(particularly for suspended solids removal), proper
operation (preferably with instrumental control), and
operator training.
The highest degree of end-of-pipe treatment presently
practiced consists of settling, aeration, solar evaporation
or neutralization, all in lagoons. The lowest discharge
levels appear at the new plants, where in-plant controls of
wastewater were built into the plant, in the way of
collection of cell spillage, recirculation, collection and
hauling of filter muds (as opposed to hydraulic transport).
It appears that the best and most economical alternatives
for existing plants involve end-of-pipe treatment of the
waste water, followed by recirculation.
With regard to this treatment, it should be noted that
treatment is simplified if smaller, more concentrated,
volumes are handled. This may be accomplished by separation
of wastes, by concentrating the waste streams, and so forth.
For example, mixture of the weak manganese waste waters with
wastewaters from other plant operations as at Plants A and C
would entail the treatment of a vast quantity of wastewater
for, say, ammonia, when the smaller volume from the
electrolytic operation could be treated more economically
and efficiently (in terms of load) separately. If ammonia
is only present in significant quantities from the
electrolytic operations, but the wastes are mixed with other
wastes for a total flow of 10,000 gpm (vs. 500 gpm) , the
load after treatment would be 20 times higher than if the
wastes were treated separately, if a given treatment yields
the same effluent concentration regardless of influent
concentrations. By contrast, waste streams which require
treatment for common parameters can be mixed to reduce the
overall costs of treatment by economies of scale.
Based upon the plant survey data and the foregoing
discussions of process and waste water treatment technology,
the treatment technologies identified as applicable to the
various industry categories are as follows:
38
-------
Category I. Electrolytic Manganese Products
Level I - pH adjustment, flocculation-clarification and
neutralization for the weak electrolytic manganese wastes
and the manganese dioxide wastes. For the strong
electrolytic manganese wastes, clarification and
recirculation-
Level II - Level I plus treatment of half the weak
electrolytic manganese wastes and the manganese dioxide
wastes for ammonia via breakpoint chlorination, then
neutralization and discharge. Recirculation after"
neutralization of the remainder.
Level III - Limitation of the quantity of wastewater by in-
plant recirculation, mechanical (non-hydraulic) transport of
filter residues, and treatment for discharge the same as for
Level I with the addition of breakpoint chlorination for
electrolytic manganese. Same as Level II for manganese
dioxide.
Category II - Electrolytic Chromium
Level I — pH adjustment, sedimentation, pH adjustment,
clarification-flocculation, treatment for ammonia via
breakpoint chlorination and neutralization for discharge.
Level II - Level I plus recirculation of half of the wastes
after neutralization.
Level III - Limitation of the quantity of wastewater by in-
plant recirculation, mechanical (non-hydraulic) transport of
filter residues, and treatment for discharge the same as for
Level I.
Sketches of these treatment levels are shown in Figures 6
and 7.
The treatment systems shown in Figures 6 and 7 are not
utilized in toto in any one plant in the industry. However,
the modules which comprise the systems are in use in this,
or similar, industries.
Plant P, studied as part of the Alloy and Stainless Steel
Industry (Ref. 12), utilizes a treatment system for chromium
neutralization and clarification similar to that shown in
the first step of Figure 7. This system had an average
influent concentration of about 18 mg/1 total chromium.
After treatment, the average concentration was 0.10 mg/1.
This system was operating on a continuous basis- Plant S of
39
-------
the Iron and Steel Industry study (Ref. 10), achieved an
average suspended solids concentration of 22 mg/1 after
clarification of scrubber water from a B.O.F. Plant D of
the Phase I ferroalloys study (Ref. 13) demonstrates the use
of alkaline precipitation of metals and the use of sand
filters, although not in a completely optimum manner.
Breakpoint chlorination for ammonia treatment is commonly
employed in municipal wastewater treatment. The treatment
scheme shown may be thought to be based upon the components
of all these systems, although as discussed above, any
particular plant may not find it necessary to utilize the
entire system.
STARTUP AND SHUTDOWN PROBLEMS
There have been no problems of consequence identified in
connection with the startup or shutdown of production
facilities insofar as waste water control and treatment is
concerned. There might be some upsets in undersized lagoons
or clarifiers used in once-through systems if the water flow
is abruptly started after a shutdown. Proper operating
procedures such as surge ponds to adjust or even out flows
can easily handle such occurences and there would be little
or no effect in sufficiently large facilities.
Loss of power can effect most of the treatment systems such
as chemicals addition for flocculation, ammonia oxidation or
metals precipitation. In such cases, however, the
production process producing the wastewater also will stop
and little effect on waste water treatment would result.
40
-------
F-/ ^r yre Co
ElecJfro ly't'ic Mo.nja.nese. Pro J itch's
Tr-caJf rnent Sys Te.yyt
-------
£le&Tro lyf ic- Chromium Tre.ajtnne.fif System
Li'me
I 2, 6>So
1/tooo U
Uime
N>
Rs' y« leofr»/yfe Ofi/o'-'iC-
'Oil
f rss
Aln
I
por
\*83
Aeic/
To
ia,isogo.l/it>oaH>
Cb3SO J* 1/tWff/b
tor tfS3)
„_R
-------
SECTION VIII
COST, ENERGY AND NON-WATER QUALITY ASPECTS
Capital and operating costs were supplied by Plants Ar B,
and C. The costs shown in Table 1 are estimates of the cost
of the treatment systems shown in Figures 6 and 7. While
these costs are estimates, they are representative of the
actual costs which might be incurred by isolated plants
producing these commodities. Some plants, such as B and D,
which already have extensive recirculation systems
installed, will incur very minor additional costs. Plant A
can take advantage of the number of waste streams and by
suitable combinations reduce the cost.
Capital and operating costs are given in terms of units of
production. These costs were based upon cost of capital at
an interest rate of 8 percent, and a depreciation period of
15 years. Power costs were calculated as a percentage of
the annual operating cost by the ratio of power to total
operating costs at Plant B, and have been assumed at one
cent per kwhr. Operating costs include annualized capital
costs.
The cost of land was not included as part of the total
investment, since it is thought that very few (if any)
plants will need to purchase land for wastewater treatment.
All of the plants have large lagoon systems, which could
either be utilized as part of a wastewater treatment system,
or used for landfilling sludge.
The following bases were used for cost calculations by
Category and Treatment Level:
Category I, Treatment Level I.
Costs were developed for the treatment system as shown in
figure 6, based on the flows at Plant A. The costs include
mechanical equipment, tanks, piping, valves, electrical,
engineering, installation, etc. They are based upon the
complete system less breakpoint chlorination and
recirculation of the weak electrolytic manganese or
manganese dioxide wastes. The investment costs will
probably be less (per kkg (ton)) for a plant larger than the
model, and greater for a plant smaller than the model.
43
-------
TABLE 1
TREATMENT LEVEL COSTS
Manganese
Manganese Dioxide
Chromium
Level
Level
Level
Level
Level
Level
Level
Level
Level
I
II
III
I
II
III
I
II
III
$/ton
$/ton
$/ ton
$/ton
$/ton
$/ton
$/ton
$/ton
$/ton
Investment Cost
29.79
8.51
92.33
23.40
7.11
30.51
90.71
8.96
157.62
Capital Costs
1.49
.43
4.63
1.17
.36
1.53
4.55
.45
7.91
Depreciation
1.99
.57
6.16
1.56
.48
2.04
6.05
.60
10.51
Operating less
Power
8.00
2.28
9.04
6,28
1.91
8.19
24.35
2.41
21.51
Power
.94
.27
1.06
.74
.22
.96
2.86
.28
2.52
Total Annual Cost
12.42
3.55
20.89
9.75
2.97
12.72
37.81
3.74
42.45
$/kkg
$/kkg
$/kkg
$/kkg
$/kkg
$/kkg
$/kkg
$/kkg
$/kkg
Investment Cost
27.08
7.74
83.93
21.27
6.47
27.74
82.46
8.15
143.29
Capital Costs
1.36
.39
4.21
1.07
.33
1.39
4.13
.41
7.19
Depreciation
1.81
.52
5.60
1.42
.43
1.85
5.50
.54
9.55
Operating less
Power
7.27
2.08
8.22
5.71
1.74
7.45
22.14
2.19
19.56
Power
.85
.24
.96
.67
.20
.87
2.60
.26
2.29
Total Annual Cost
11.29
3.23
18.99
8.87
2.70
11.56
34.37
3.40
38.59
-------
Operating and maintenance costs at this level of estimation
are best figured as a percentage of capital costs for
similar type plants- The "Inorganic Chemicals Industry
Profile" indicated for 59 plants surveyed operating costs
per annual unit of production equal to 28 percent of the
capital cost per annual unit of production. The operating
costs at Plant C of the Phase I ferroalloys study are equal
to 23.4 percent per year of the capital cost. The operating
costs at Plant D of the Phase I ferroalloys study are equal
to 23.0 percent of the capital cost. The operating costs at
Plant B of the ferroalloys Phase I study are equal to 30.9
percent per year of the capital costs. Operating costs are
thus estimated on the basis of 30 percent per year of the
estimated capital cost.
Category I, Treatment Level II.
These are incremental costs above Level I, and include costs
of recirculation of the weak electrolytic manganese and
manganese dioxide wastes and breakpoint chlorination, with a
proportionate increase in annual and operating costs.
Category I, Treatment Level III
Costs for electrolytic manganese are based upon those at
Plant B and have been expanded to include the cost of
treatment of the wastewater for discharge. Costs for
manganese dioxide are the total cost of Level II treatment.
These are the total costs which a new plant might expect to
incur, while those shown for Levels I and II are incremental
costs.
Category II, Treatment Level I.
Costs were developed for the treatment system shown in
Figure 7 less the recirculation portion and are based on the
flow rate from the electrolytic chromium facility at Plant
A. As before, the investment cost per unit of production
will be somewhat higher for small plants and less for large
plants.
Category II, Treatment Level II
The additional cost here is for the recirculation portion
and the costs shown are incremental above Level I treatment.
45
-------
Category II, Treatment Level III
Total costs of inplant recirculation were scaled from those
of Plant B and include the cost of treatment of the
discharge stream as in Level I.
Figures 8 and 9 show the relative costs of treatment for
reduction of effluent loads of the critical pollutants from
the raw wastes. These curves provide graphical information
of interest, but must be read in the context of the
previously described Treatment Levels to be of value.
ENERGY AND NON-WATER QUALITY ASPECTS
There are significant energy and nonwater quality aspects to
the selection and operation of treatment systems. These may
be considered as land requirements, air and solid waste
aspects, by-product potentials, and energy requirements.
Land Requirements
One of the important aspects in the selection of wastewater
treatment systems in this industry is the land required for
water treatment systems. Many plants in this industry have
extensive land areas available for such uses and may elect
to use this land, and existing lagoons, as part of their
water treatment system. Other plants might possibly not
have land readily available and would have to select
alternative treatment systems such as the use of filters for
sludge dewatering, rather than sludge lagoons, for this
reason alone.
Air and Solid Wastes
The solid waste produced by treatment of,waste waters in the
industry derives principally from electrolyte preparation as
waste from leaching. The solid waste from leaching is
produced whether the leach residue is hydraullically or
mechanically transported and varies only in that the former
produces a slurry, the latter a sludge. The slurry is
generally accumulated in sludge lagoons or tailings ponds,
while the sludge may be landfilled or simply piled. More
careful attention should be directed to the disposal of
these potentially harmful materials. Possible improvements
might be landfilling in a sealed site, or encapsulation in
concrete or polymers.
For those waste materials considered to be non-hazardous
where land disposal is the choice for disposal, practices
similar to proper sanitary landfill technology may be
46
-------
followed. The principles set. forth in the EPA,s Land
Disposal of Solid Wastes Guidelines (CFR Title 40, Chapter
1; Part 241) may be used as guidance for acceptable land
disposal techniques.
For those waste materials considered to be hazardous,
disposal will require special precautions. In order to
ensure long-term protection ' of public health and the
environment, special preparation and pretreatment may be
required prior to disposal. If land disposal is to be
practiced, these sites must not allow movement of pollutants
such as fluoride and radium-226 to either ground or surface
water. Sites should be selected that have natural soil and
geological conditions to prevent such contamination or, if
such conditions do not exist, artificial means (e.g.,
liners) must be provided to ensure long-term protection of
the environment from hazardous materials. Where
appropriate, the location of solid hazardous materials
disposal sites should be permanently recorded in the
appropriate office of the legal jurisdiction in which the
site is located.
By-Product Potentials
The recovery and use of ferrous ammonium sulfate from
electrolytic chromium production, rather than disposal by
chemical precipitation and sedimentation depends upon local
market conditions. However, since all producers have at
least the equipment to produce a crude ferrous ammonium
sulfate, recovery of this material may offer potential for
the reduction of overall costs.
Energy Requirements
Power requirements for waste water treatment systems are
generally low. Power uses range from less than one percent
to two percent of the power used in the cell room.
Monitoring
For the purpose of writing a permit, one would need to know
historical production figures for the plant. An alternative
for plants which do not possess historical production data
would be the use of capacity figures.
Historical data covering a year's time would probably be
necessary, although in the case of a plant which is
presently producing well below capacity, but plans to
increase production in the future, a longer period might be
necessary.
47
-------
Once the permit, has been issued, the plants would need to
monitor the appropriate flows and concentrations of the
pollutant parameters so that the pollution load from the
plant may be reported as lb/day.
/
48
-------
J~ i cjf C &
Cost e>9 vs. £(¦$ )«se ¥roducT&
o.M-rtn~ Ps
IS.n-rtn BAT
iz.y» - 1 nOz
ia.yg-^n bfT
t,7,T-Mrtfa. ®PT
O
to
to
* 0 ft
-------
f~iy L/r-e.
Cost c>i" Tr&a"th)e.y)'(~ t/s. B.-frflveni' feedt/c-'t'ion
B iec.tr-0 lyf~i~c Chraryu'vw
°/o Reduc.f/ o 17
'
-------
SECTION IX
BEST PRACTICABLE CONTROL TECHNOLOGY CURRENTLY AVAILABLE,
GUIDELINES AND LIMITATIONS
INTRODUCTION
The effluent limitations which must be achieved by July 1,
1977 are to specify the degree of effluent reduction
attainable through the application of the Best Practicable
Control Technology Currently Available. This is generally
based upon the average of the best existing plants of
various sizes, ages and unit processes within the industrial
category and/or subcategory.
Consideration must also be given to:
a. The total cost of application of technology in
relation to the effluent reduction benefits to be
from such application.
b. the size and age of equipment and facilities
involved;
c. the processes employed;
d. the engineering aspects of the application of various
types of control techniques;
e. process changes;
f. non-water quality environmental impact (including
energy requirements).
Also, Best Practicable Control Technology Currently
Available emphasizes treatment facilities at the end of a
manufacturing process but includes the control technologies
within the process itself when the latter are considered to
be normal practice within an industry.
A further consideration is the degree of economic and
engineering reliability which must be established for the
technology to be "currently available." As a result of
demonstration projects, pilot plants and general use, there
must exist a high degree of confidence in the engineering
and economic practicability of the technology at the time of
commencement of construction or installation of the control
facilities.
51
-------
Definition of what constitutes 'best practicable1 technology
for many industries involves, at first, a general review of
the industry to determine the best technologies being
practiced in the industry. Then after closer review and
investigation of these technologies, the 'best practicable*
technology would be assessed as the average of the best,
though not necessarily the best technology, after taking
into account information relating to other factors spelled
out in the Act- In those industries where present treatment
is uniformly inadequate, a higher degree of treatment than
is presently practiced may be required, based on a
comparison with existing treatments for similar wastes in
other industries. Factors for determining the 'best
available' technology are similar, except that rather than
assessing the average of the best, the focus is on the very
best technology currently in use or demonstrably achievable.
Under this analysis of the statutory standard, it is the
opinion of the Agency that it is not necessary that 'best
practicable' technology be currently in use as a single
treatment.
EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION OF
BEST PRACTICABLE CONTROL TECHNOLOGY CURRENTLY AVAILABLE
(BPCTCA)
Based upon the information contained in Sections III through
VIII of this report, a determination has been made that the
degree of effluent reduction . attainable through the
application of the best practicable control technology
currently available is the application of Level I Treatment
as described in Section VII and below.
Category I - Electrolytic Manganese Products
pH adjustment, flocculation-clarification and neutralization
for the weak electrolytic manganese wastes and the manganese
dioxide wastes. For the strong electrolytic manganese
wastes, clarification and recirculation.
Category II - Electrolytic Chromium
pH adjustment, sedimentation, pH adjustment, clarification-
flocculation, treatment for ammonia via breakpoint
chlorination and neutralization for discharge.
These guidelines were formulated on the basis of readily
available technology which will achieve reasonable effluent
quality by generally end-of-pipe treatment, i.e., with
mostly once-through water use.
52
-------
These guidelines do not appear to present any particular
problems in implementation at existing plants, aside from
required better operation and more extensive segregation of
wastes from other plant wastes. The size or age of
facilities has no bearing on applicability, aside from some
differences in costs. The only process change required for
manganese plants is the reuse of the strong wastes after
clarification, which is demonstrated at Plant B.
The effluent limitations here apply to measurements taken at
the outlet of the last waste water treatment process unit.
The effluent loads representing the allowable 30 day average
limitations applicable to the Best Practicable Control
Technology Currently Available Guidelines and Limitations
are summarized below. The 24 hour maximum effluent
limitations are twice (two times) the allowable 30 day
average limitations, except for pH.
Effluent Limitations
kg/kkg (lb/1000 lb)
. TSS Mn Cr NH3-N pH
Category I-Mn 3.389 1.356 — 20.334 6.0 - 9.0
Category I-Mn02 0.881 0.352 — 5.287 6.0 - 9.0
Category II 2.638 1.055 0.106 5.276 6.0 - 9.0
Category I
The costs here would be those given in Section VIII for
treatment level I. The flow volumes upon which the
limitations are based are 135,314 1/kkg (16,250 gal/1000 lb)
for electrolytic manganese and 35,182 1/kkg (4,225 gal/1000
lb) for manganese dioxide.
Although the entire treatment system is not presently in use
at any one plant, portions of the suggested technology as
shown in Figure 6 are readily transferable from other plants
within this or similar industries. No innovative or new
technology is involved - rather, the application of existing
and fairly pedestrian technology to this industry^ problem.
Category II
The flow volumes upon which the limitations are based is
105,337 1/kkg (12,650 gal/1000 lb). In-plant recovery of
ferrous ammonium sulfate should result in lowering or
eliminating the cost of treatment for ammonia.
53
-------
Although the technology is not in use at any one plant, the
portions are in use at various plants or are readily
transferrable.
The suggested guidelines do not appear to present any
particular problems in implementation. The processes
involved are all in present use in ferroalloy or similar
plants or are common waste water treatment methods and no
engineering problems are involved in design or construction.
Process changes other than recirculation are not required in
any existing plants and the size or age of facilities has
little or no bearing on the applicability of these methods.
Some additional solid wastes are generated by the suggested
treatment methods since better treatment than is presently
practiced is suggested. Power consumption for treatment is
about 1 to 2 percent of that used in the cell room.
54
-------
SECTION X
BEST AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE,
GUIDELINES AND LIMITATIONS
INTRODUCTION
The effluent limitations which must be achieved by July 1,
1983 are to specify the degree of effluent reduction
attainable through the application of the Best Available
Technology Economically Achievable.. Best Available
Technology Economically Achievable is determined by the very
best control and treatment technology employed by a specific
point source within the industry category or by technology
which is readily transferable from another industrial
process.
Consideration must also be given to:
a. The age of equipment and facilities involved;
b. the process employed;
c. the engineering aspects of the application of various
types of control techniques;
d. process changes;
e. cost of achieving the effluent reduction resulting from
the application of this level of technology;
f. non-water quality environmental impact (including
energy requirements).
Also, Best Available Technology Economically Achievable
assesses the availability of in-process controls as well as
additional treatment at the end of a production process.
In-process control options include water re-use, alternative
water uses, water conservation, by-product recovery, good
housekeeping, and monitor and alarm systems.
A further consideration is the availability of plant
processes and control techniques up to and including "no
discharge" of pollutants. Costs for this level of control
are to be the top-of-the-line of current technology subject
to engineering and economic feasibility.
55
-------
EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION OF
BEST AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE (BATEA)
Based upon the information contained in Sections III through
VIII of this report, a determination has been made that the
degree of effluent reduction attainable through the
application of the best available control technology
economically achievable is the application of the Level II
Treatments as described in Section VII and below.
Category I - Electrolytic Manganese Products
Level I plus treatment of half the weak electrolytic
manganese wastes and the manganese dioxide wastes for
ammonia via breakpoint chlorination, then neutralization and
discharge. Recirculation after neutralization of the
remainder.
Category II - Electrolytic Chromium
Level I plus recirculation of half of the wastes after
neutralization.
These guidelines were formulated on the basis of technology
that is in use in surveyed plants or transferrable. These
guidelines do not appear to present any particular problems
in implementation from an engineering standpoint and require
no process changes other than recirculation.
The effluent limitations here apply to measurements taken at
the outlet of the last waste water treatment process unit.
The 30 day average effluent loads applicable to the Best
Available Technology Economically Achievable Guidelines and
Limitations are summarized below. The 24 hour maximum
effluent limitations are twice (two times) the allowable 30
day average limitations, except for pH.
Effluent Limitations
kg/kkg (lb/1000 lb)
TSS Mn Cr NH3-N pH
Category I-Mn
Category I-Mn02
Category II
1.695 0.339
0.441 0.088
1.324 0.265
3.389 6.0 - 9.0
0.881 6.0 - 9.0
0.027 2.649 6.0 - 9.0
56
-------
Category I
The effluent load reduction above Level I is primarily due
to the effluent reduction attained through recirculation,
although some of the reduction is due to lower
concentrations in the effluent. Portions of the technology
described are in use at various ferroalloys plants, and no
new or innovative technology is required. The flow volumes
upon which the limitations are based are 67,657 1/kkg (8125
gal/1000 lb) for electrolytic manganese and 17,590 1/kkg
(2110 gal/1000 lb) for manganese.dioxide.
Category II
Again, load reduction above Level I is due primarily to the
reduction in effluent volume attained by recirculation. As
before, no innovative technology is required. The flow
volume upon which the limitations are based is 52,876 1/kkg
(6350 gal/1000 lb).
Summary
The suggested Guidelines present no particular problems in
implementation from an eingineering aspect and require no
process changes other than water reuse. Water reuse and
good housekeeping are emphasized. Age of equipment and
facilities are of no particular importance although they may
slightly affect the costs of achieving the effluent
limitations.
No additional solid wastes of significance are created by
the suggested treatment methods. Increased power
consumption may amount to as much as 2 percent of productive
power in the most energy intensive water treatment system.
The effluent limitations here apply to measurements taken at
the outlet of the last waste water treatment process unit.
It is not judged to be practical to require the treatment or
control of runoff due to storm water for the 19 83 standards
for existing plants. In one steel mill where it was
proposed to collect runoff and treat the collected water in
a lagoon, the costs involved were equal to the total
expenditures for a minimum discharge recirculation system
for process wastewaters.
57
-------
Page Intentionally Blank
-------
SECTION XI
NEW SOURCE PERFORMANCE STANDARDS
AND PRETREATMENT STANDARDS
INTRODUCTION
The effluent limitations which must be achieved by new
sources, i.e., any source, the construction of which is
started after publication of new source performance standard
regulations, are to specify the degree of treatment
available through the use of improved production processes
and/or treatment techniques. Alternative processes,
operating methods or other alternatives must be considered.
The end result is to identify effluent standards achievable
through the use of improved production processes (as well as
control technology). A further determination which must be
made for the new source performance standards is whether a
standard permitting no discharge of pollutants is
practicable.
Consideration must also be given to:
a. The type of process employed and process changes;
b. operating methods;
c. batch as opposed to continuous operation;
d. use of alternative raw materials and mixes of raw
materials;
e. use of dry rather than wet processes;
f. recovery of pollutants as by-products.
In addition to recommending new source performance standards
and effluent limitations covering discharges into waterways,
constituents of the effluent discharge must be identified
which would interfere with, pass through or otherwise be
incompatible with a well designed and operated publicly
owned activated sludge or trickling filter waste water
treatment plant. A determination must be made as to whether
the introduction of such pollutants into the treatment plant
should be completely prohibited.
59
-------
EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION OF NEW
SOURCE PERFORMANCE STANDARDS
Based upon the information contained in Sections III through
VIII of this report, a determination has been made that the
degree of effluent reduction attainable by new sources is
the application of the Level 3 treatments as described in
Section VII.
The new source performance standards are based upon the best
available demonstrated control technology, process,
operating methods, or other alternatives which are
applicable to new sources. The best available demonstrated
control technology for new sources is as follows, by
category:
Category I - Limitation of the quantity of wastewater by in-
plant recirculation mechanical (non-hydraulic) transport of
filter residues, and treatment for discharge the same as for
Level I with the addition of breakpoint chlorination for
electrolytic manganese. For manganese dioxide, the same as
for BATEA.
Category II - Limitation of the quantity of wastewater by
in-plant recirculation, mechanical (non-hydraulic) transport
of filter residues, and treatment for discharge the same as
for Level I.
The 30 day average new source limitations are as follows, by
category. The 24 hour maximum effluent limitations are
twice (two times) the allowable 30 day average limitations,
except for pH.
Effluent Limitations
kg/kkg (lb/1000 lb)
TSS Mn Cr NH3-N pH
Category I-Mn 0.740 0.148 — 1.481 6.0 - 9.0
Category I-Mn02 0.441 0.088 — 0.881 6.0-9.0
Category II 0.417 0.083 0.008 0.834 6.0 - 9.0
These performance standards have been selected on the basis
of the following assumptions and considerations:
Category I
The standard for this subcategory is based on the actual
performance of Plant B, with treatment to reduce the
manganese to more acceptable levels. The standard for
manganese dioxide is based upon the application of the best
60
-------
available control -technology economically achievable- The
flow volumes upon which the limitations are based are 29,561
1/kkg (3 550 gal/1000 lb) for electrolytic manganese and
17,590 1/kkg (2110 gal/1000 lb) for manganese dioxide.
Costs are as shown in Section VIII.
Category II
The standard here is based upon the reported performance of
Plant D, with the exception that an allowance has been made
for the wastes which are evaporated at Plant D, but which
plants at other locations with greater rainfall than
evaporation rates might find it necessary to discharge. The
flow volume upon which the limitations are based is 16,654
1/kkg (2000 gal/1000 lb). Costs are as shown in Section
VIII.
SUMMARY
New plants in this segment of the ferroalloys industry have,
more and less expensive options available as regards
minimization of discharge than dp older, existing plants.
New plants can design and construct recirculation and
treatment systems as an integral part of the operation,
while for existing plants such modifications might be either
exorbitant or simply very difficult to accomplish.
For the new source performance standards, it should be
additionally specified that all measurements taken for
purposes of meeting the effluent limits should be at the
plant outfall, if the new source is a new plant.
For new source performance standards applied to new plants,
measurements should be taken at the plant outfall. This
means that run-off from materials handling and storage,
sludge disposal, etc. must be collected and treated or that
storm water must not contact such sources of pollution.
Control methods can include wastes disposal in landfills or
impoundment or diversion of storm water. The option, of
course, of treating run-off is available. Such measures can
be incorporated into new plants, but would generally be
impractical in old plants. If the new source is part of an
existing plant, the applicable measurement should be taken
at the outlet of the last waste water treatment process
unit.
61
-------
PRETREATMENT STANDARDS
The pretreatment standards under Section 307 (c) of the Act,
for a source within the ferroalloys industry which is an
industrial user of a publicly owned treatment works (and
which would be a new source subject to Section 306 of the
Act, if it were to discharge to navigable waters), shall be
the standard set forth in Part 128, 40 CFR, except that the
pretreatment standard for incompatible pollutants shall be
the standard of performance for new sources of that
subcategory. If the publicly owned treatment works is
committed, in its NPDES permit, to remove a specified
percentage of any compatible pollutant, the pretreatment
standard applicable to users of such treatment works shall
be corresponding reduced for that pollutant.
62
-------
SECTION XII
ACKNOWLEDGEMENTS
Sincere thanks is expressed to the author's associates in
the Effluent Guidelines Division of the Environmental
Protection Agency, particularly Messrs- Walter J. Hunt,
Ernst P. Hall, and Allen Cywin for their assistance and many
helpful suggestions during the course of this project.
The Datagraphics, Inc. staff members who contributed to the
preparation of the draft Contractor1s report included Dr. H.
C. Bramer, Messrs. E. Shapiro, N. W. Elliott, D. C. Bramer,
D.. Riston, G,. Robinson, C, A. Caswell, and A. W. Leavitt,
and Mrs. K. L.. Durkin. Particular appreciation is extended
to Ms. Darlene Speight for her long hours and diligence in
editing and typing this report.
Thanks are extended to those companies and their plant
personnel who permitted sampling surveys at their plants.
Particular thanks are extended to the following persons who
provided cooperation in performing this study:
Foote Mineral Company
Kerr-McGee Chemical Corporation
Prairie Chemical company
Union Carbide Corporation
Mr. W. D. Morgan
Mr. P. M. Dampf
Mr. T. L. Hurst
Mr. Denver Harris
Dr. C. R- Allenbach
Mr,. E. Springman
Mr. G. Porter
Mr. J- E. Banasik
Thanks are also given to the members of the EPA Working
Group/Steering Committee for their cooperation and
assistance. They are Messrs. Walter J. Hunt, T. Powers,
Dr. H. Durham and Ms. N. Speck.
63
-------
Page Intentionally Blank
r H
-------
SECTION XIII
REFERENCES
1. Smith, A. E., "A Study of the Variation with pH of the
Solubility and Stability of Some Metal Ions at Low
Concentrations in Aqueous Solution (Part 1 and 2) ", Analyst,
January and March 1973, pp. 65-6 8, pp. 209-212.
2. Sully, A- H-, "Metallurgy of the Rarer Metals - 3,
Manganese", Academic Press Inc., New York, pp. 57-79.
3. Carosella, M. C. and Mettler, J. D., "The First
Commercial Plant for Electrowinning Chromium from Trivalent
Salt Solutions", Proceedings of a Conference held at the
1955 Metal Congress and Exposition of tBe American Society
for Metals, Copyright 1957, pp. 75-90. "
4. Dean, Reginald S., "Electrolytic Manganese and Its
Alloys", The Ronald Press Company, New York, pp. 3-76.
5. Sully, A. H., "Metallurgy of the Rarer Metals - 1,
Chromium", Academic Press Inc., New York, pp. 17-55.
6. "Facts about Manganese", united States Department of
the Interior, Bureau of Mines, July 1953.
7. Bennett, R. H., "A Decade of Electrolytic Manganese",
Engineering and Mining Journal, 1949.
8. "124 Process Flowsheets", published by Chemical
Engineering, New York, pp. 22,26.
9. "Development Document for Effluent Limitations
Guidelines and New Source Performance Standards - Basic
Fertilizer Chemicals Segment of the Fertilizer Manufacturing
Point source Category", EPA-440/l-74-011-a, (March 1974),
Office of Air and Water Programs, U.S. Environmental
Protection Agency, Washington, D.C. 20460.
10. "Development Document for Proposed Effluent Limitations
Guidelines and New Source Performance Standards for the
Steel Making segment of the Iron and Steel Manufacturing
Point Source Category", EPA—440/1-73/024, (February 1974),
Office of Air and Water Programs, U.S. Environmental
Protection Agency, Washington, D.C. 20460.
65
-------
11. "Biological Removal of Carbon and Nitrogen compounds
from Coke Plant Wastes", EPA-R2-73-167, (April 1973), Office
of Research and Monitoring, U.S. Environmental Protection
Agency, Washington, D.C. 20460.
12. "Draft Development Document for Effluent Limitations
Guidelines and Standards of Performance—Alloy and Stainless
Steel Industry", Datagraphics, Inc., Pittsburgh, PA, January
1974 (EPA Contract No. 68-01-1527).
13. "Development Document for Effluent Limitations
Guidelines and New Source Performance Standards for the
Smelting and Slag Processing Segments of the Ferroalloy
Manufacturing Point Source Category", EPA-440/1-74-008a,
(February 1974), Office of Air and Water Programs, U.S.
Environmental Protection Agency, Washington, D.C. 20460.
66
-------
SECTION XIV
GLOSSARY
Terms defined in -the report are not included in this
section.
Anolyte — In a two-solution electrolytic cell, the plating
solution at the anode that is relatively exhausted and being
replaced by the incoming cell feed. It is usually acidic-
Blowdown - A relatively small bleedoff discharge, continuous
or periodic, from a recirculated closed system.
Catholvte - In a two-solution electrolytic cell, the
incoming cell feed containing a relatively high
concentration of the metal to be plated on the cathode.
Clarification - The process of removing undissolved
materials from a liquid by settling or filtration.
Coagulant - A substance that enhances the aggregation of
undissolved suspended matter.
Electrodeposition - The deposition of metal on the cathode
induced by a low-voltage direct current.
Electrolytic Process - A low voltage direct current passes
through an electrolyte containing metallic ions will cause
the metallic ions to plate on the cathode as free metal
atoms. The process is used to produce chromium and
manganese metal, which are included with the ferroalloys.
Chromium metal produced by this process is 99+ percent pure.
Flocculation - The aggregation of undissolved suspended
maitter'into ~larger conglomerates.
Leach — The dissolution of matter from a multi-component
solid mass, such as ore or slag, with an aqueous medium.
Polyelectrolvte - A substance (polymer) that enhances the
flocculation mechanism.
Slag - A product resulting from the action of a flux on the
non-metallic constituents of a processed ore, or on the
oxidized metallic constituents.
67
-------
Multiply (English Units)
English Unit
acres
acre-feet
British Thermal Unit
British Thermal Unit/pound
cubic feet/minute
cubic feet/second
cubic feet
cubic feet
cubic inches
degree Fahrenheit
feet
gallon
gallon/minute
horsepower
inches
inches of Mercury
pounds
million gallons/day
mile
pound/square inch (gauge)
square feet
square inches
tons (short)
yard
Abbreviation
ac
ac ft
BTU
BTU/lb
cfm
cfs
cu ft
cu ft
cu in
°F
ft
gal
gpn
hp
in
in Hg
lb
mgd
mi
psig
sq ft
sq in
t
y
Actual conversion, not a multiplier
TABLE 2
CONVERSION FACTORS
by To Obtain (Metric Units)
Conversion Abbreviation Metric Unit
0.405
ha
hectares
1233.5
cu m
cubic meters
0.252
kg cal
kilogram-calories
0.555
kg cal/kkg
kilogram-calories/kilogram
0.028
cu m/min
cubic meters/minute
1.7
cu m/min
cubic meters/friinute
0.028
cu m
cubic meters
28.32
1
liters
3.6.39
0.555(°F-32) w
cu cm
cubic centimeters
°C
degree Centigrade
0.3048
m
meters
3.785
1
liters
0.0631
1/sec
liters/second
0.7457 "
kw
kilowatts
2.-54
cm
centimeters
0.03342
atm
atmospheres
0.454
kg
kilograms
3,785
cu m/day
cubic meters/day
1.609
km
kilometer
(0.06805 psig +1)
(a)atm
atmospheres (absolute)
0.0929
sq m
square meters
6.452
sq cm
square centimeters
0.907
kkg
metric tons (1000 kilograms)
0.9144
m
meters
------- |