-------
Percentage 2! Sugar Coated Cereal-
In Figure 16, average BOB5 loadings per unit of finished product
are compared with the proportion of cereal that is sugar coated
at a plant. The value of the correlation coefficient is 0.629,
indicating a fair degree of correlation between organic waste
load and amount of cereal being coated. A general trend of
increasing BOC5 with increasing percentage of cereal being coated
is indicated. This rright be expected, as increasing coating
operations probably result in larger quantities of sugar entering
the plant effluent during cleanup operations.
WHEAT STARCH AND GLUTEK MANUFACTURING
Water Use
The use of water is integral to the processes involved in starch
and gluten manufacturing. Basically the manufacture of wheat
starch is a wet separation of the starch and gluten components of
wheat flour. Fresh water enters the operation at several dif-
ferent points, as shown in the process flow diagram, Figure 10 in
Section III. Water is mixed with the flour to form a dough.
More water is used in the washing operations which separate the
starch from the gluten. In the screening steps, water is used
for back-washing fibre collected on coarse screens and for
countercurrent washing of the overflow (fibres) leaving the fine
screens. A major water use in the process occurs in the refining
of the crude starch milk. As the refining centrifuges separate
the heavy component, A-starch, from the light component, B-
starch, a fresh water stream washes the heavy component
countercurrently. Smaller quantities cf water are also used for
cleanup, cooling, and boiler operation.
Total water use in wheat starch plants varies from 284 to 946 cu
m/day (75,000 to 250,000 gpd) depending mainly on plant capacity.
The water use per unit of raw material ranges from 10.4 to 13.0
cu m/kkg (1.25 to 1.56 gal/lb) of flour.
Waste Water Characteristics
In the wheat starch manufacturing process, waste waters are gen-
erated primarily from starch milk screening and centrifugation.
The fibre washed from the coarse screens enters the waste stream
in most plants. Data frorrr one plant indicate that the screening
operation produced a 0.17 to 0.28 liter/sec (2.7 to 4.4 gal/min)
waste stream containing 5.0 to 6.0 percent solids. This is a
volume of 15 to 24 cu m/day (4000 to 6300 gpd) with a total
solids loading of 809 to 1494 kg/day (1783 to 3291 Ib/day).
Discharges from starch milk thickening and concentrating opera-
tions make up the balance of the waste waters, although cleanup
may generate additional small volumes.
49
-------
vn
o
•o
ID
O
g _
O »
15 S
O S
£
O °
I a
20
18
16
14
12
10
8
6
4
2H
regression •»—«••
range of average plant data ^•-••-;'-'v3
correlation coefficient (r) = 0.629
0 10 20 30 40 50
percentage of cereal sugar coated
i i
60 70
I
80
90 100
FIGURE 16
AVERAGE BOD DISCHARGED AS A FUNCTION OF PERCENTAGE OF COATED CEREAL PRODUCED
-------
The remainder of the data accumulated on wheat starch operations
relate to total waste flows. Summary data from six of the seven
plants are included in Table 6. The seventh plant uses its
starch waste stream as raw material feed in a distillery opera-
tion and, therefore, the plant's waste characteristics are not
representative of the industry. The sixth plant listed in Table
6 also processes soybeans and has a canning operation that
generates waste waters.
BOD5 values for the six plants range from 6500 to 14,600 mg/1,
with the higher concentrations corresponding to larger plants.
Suspended solids concentrations range from 51UC to 14,800 mg/1,
and, again, the higher concentrations tend to correspond to the
larger plants.
The pH of wheat starch plant effluents is generally acidic, in
the range of 3 to 6, although data from one plant indicate a
neutral pH. Limited data on phosphorus and nitrogen show rather
high values. Total phosphorus concentrations at two plants
varied from 75 to 140 mg/1, and total nitrogen values ranged from
350 to 400 mg/1. Waste temperatures varied from 70 to 80°F for
the various wheat starch plants.
The information contained in the preceding table is presented in
Table 7 in terms of raw material input, i.e., kg/kkg (lbs/1000
Ibs) of wheat flour. The plant numbers in the two tables do not
correspond to one another.
BOD5 in terms of raw material input ranges from 80 to 108 kg/kkg
(lbs/1000 Ibs), and averages 90.7 kg/kkg (lbs/1000 Ibs). Sus-
pended solids loads vary in the same range, from 52 to 110 kg/kkg
(lbs/1000 Ibs), with an average value of 75.7 kg/kkg
(lbs/1000 Ibs) . Available COD data show a range of 116 to 260
kg/kkg (lbs/1000 Ibs) averaging 198.6 kg/kkg (Ibs/lOOC Ibs). The
waste water flows are fairly consistent throughout the plants
studied, varying from 7.5 to 12.5 cu m/kkg (0.9 to 1.5 gal/lb) ,
Averaging 9.9 cu m;kkg (1.19 gal/lb). Generally, the waste water
characteristics in the wheat starch subcategory show good
correlation when expressed in loadings per unit of raw material.
Factors Affecting Waste Water Characteristics
As with waste waters from ready-to-eat cereal plants, there is
some variability in waste quantity and character in the wheat
starch and gluten industry. Many factors may be responsible for
these variations, and the following discussion outlines several
attempts to correlate certain factors with raw waste loads.
A.3S of Plant
Data on five wheat starch plants were utilized in an attempt to
relate raw waste loads per unit of raw material to plant age.
Figures 17 and 18 show the results for ECD5 and suspended solids,
51
-------
Table 6
Total Plant Raw Waste Water Characteristics
Wheat Starch Manufacturing
Suspended
BOD, mg/1 COD, mg/1 _ Solids, mg/1
Plant
1
2
3
It
5
6
Average
10,610
6895
9600
14,633
6500
6200
Range
-
600-16,200
8060-12,700
7968-22,^95
-
-
Average
25,OitO
-
12,300 11
35,057
9300
16,000
Range
-
-
,600-13,500
1661-42,992
5100-12, itOO
-
Average
9527
5litl
7500
lit, 824
4176
6910
Range
-
500-19,580
2400-12, 600
3468-21,442
-
_
Average
4.9
-
3.5
4.6
-
3.9
Range
-
-
3.4-4.2
4.2-5.7
-
_
-------
Table 7
Waste Water Characteristics Per Unit of Raw Material
Wheat Starch Manufacturing
Flow
LO
Plant
1
2
3
1;
5
cu m/kkg
12.1*2
7.1*2
8.50
9-75
11.67
gal/lb
1.1*9
0.89
1.02
1.17
1.1*0
BOD
kg/kkg
(rbs/1000 Ibs'
80.8
108. 1*
90.3
93.5
80.5
COD
kg/kkg
(lbs/1000 Ibs)
115.6
259-6
213.0
206.0
Suspended Solids
kg/kkg
(lbs/1000 Ibs)
51-9
109.8
81.0
73.0
60.1
Average
9-95
1.19
90.'
198.6
75.2
-------
Ln
CD
0)
0)
O)
>•
X
O
o g
E £
0) e
£ 8
O £
•2 ^
.0 ^
120-
110-
100-
90-
80-
70-
60-
50-
40-
30-
20-
10-
0
line of regression
range of average plant data
correlation coefficient (r): 0.655
I
2
0
age (years)
i i i i i I I I I I I 1 I I
6 8 10 12 14 16 18 20 22 24 26 28 30 32
FIGURE 17
AVERAGE BOD DISCHARGED AS A FUNCTION OF WHEAT STARCH PLANT AGE
-------
en
3 1
8 4
0> X
a §
(ft £
en J
120-
110-
100-
90-
80-
70-
60-
50-
40-
30-
20-
10-
0-
T
2
"T
4
tin* of regression
rang* of average plant data
correlation coefficient (r): 0.809
I
8
10 12 14 16 18 20 22 24 26 28 30 32
age (year*)
FIGURE 18
AVERAGE SUSPENDED SOLIDS DISCHARGED AS A FUNCTION OF WHEAT STARCH PLANT AGE
-------
respectively. The correlation coefficients, 0.655 and 0.809, are
quite high, indicating the possibility of a definable
relationship. The regression lines indicate that waste loads
generally increase with increasing plant age.
Size of Plant-
The possibility of a relationship between wheat starch raw waste
loads and plant capacity was investigated, and the results are
shown in Figures 19, 20, and 21. Daily waste water flow corre-
lated well with plant capacity, as shown in Figure 19. The high
value of the correlation coefficient, 0.795, indicates a reason-
ably good fit of the data with the regression line, as might be
expected. Figure 20 attempts to relate BODJ3 loadings per unit of
wheat floiar to plant capacity. The low correlation coefficient,
C.365, indicates that there is no definable relationship. In
Figure 21,, suspended solids loadings are plotted versus plant
capacity. In this case, a high correlation coefficient of 0.688
was obtained, indicating a good probability that suspended solids
loadings increase as plant size increases in a definable
relationship.
In comparing Figures 17, 18, 20, and 21, it should be noted that
the larger wheat starch plants also tend to be the olde;r plants.
Thus, a particular figure may not be showing the effect of just
one variable on raw waste loads. It should also be noted that
the raw waste load values, particularly for BOD5, do not vary a
great deal from plant to plant. This fact, plus the limited
number of data points, influenced the decision not to further
subcategorize the wheat starch industry on the basis of age and
size of plant, or waste water characteristics.
^ter Use and Waste Water Dischjircje-
It has been speculated that there might be a relationship between
the total waste load and the volume of waste water discharged.
Figures 22 and 23 were developed to evaluate this hypothesis and
clearly show that no such relationship exists,, The correlation
ooeffieisant values of -0.109 and 0.106 indicate little or no cor-
relation.
56
-------
.6-
.5 -
.4 -
.3 -
S- -2
01
0) E
O) 0
CO I
£ u
U o
.2 §
•O -T
.1 -
o-J
.14-
.12-
.10-
.08-
.06-
I/I
o
5-.02H
o
0
line of regression •".TIT:
range of average plant data hv».-M
correlation coefficient (r) = 0.795
0 20 40 60
(1000 Ib. of flour/day)
80
100 120 140 160 180 200 220
1 1 1 I
0 25 50 75
(kkg of flour /day)
plant capacity
FIGURE 19
WASTE WATER DISCHARGE AS A FUNCTION OF WHEAT STARCH PLANT CAPACITY
100
-------
m £
3D jjj (Ib./lOOOIb. or kg/kkg)
5 m
mro -- 10 w ** u» O>
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m _ • I I I I I I
0 T» £ ° *
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litli
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pllll
llllll
tX'X'il'xvx-XM
mmm
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-------
tfi
8
•0
110-
100-
90-
80
70-
60-
50-
40-
30-
20-
10-
line of regression — —«.
rang* of average plant data tsas-a
correlation coefficient (r) = 0.688
1 1 1 1 1 1 1 1 1 I 1
0 20 40 60 80 100 120 140 160 180 200 220
(1000 Ib. of flour/day)
i
50
I
75
0 25
(kkg of flour/day)
plant capacity
FIGURE 21
AVERAGE SUSPENDED SOLIDS DISCHARGED AS A FUNCTION OF WHEAT STARCH
PLANT CAPACITY
100
-------
^ ^ 3 biochemical oxygen demand
3D 3 5 (lb./ 1000 Ib. or kg/kkg)
^^ i^ ^^
I £ m _,K>W*-OiOvjOO-OO — (O
^M OOOOOOOOOOOOO
?_ M _ 1 1 1 1 1 1 1 II 1
ii £ i
H ° 0 °
o§ ? §
— (A ~« "
W O (Q n •_-
Oi
^™ ^^
1 1 1 1
.3 .4 .5 .6
t FUNCTION OF WHEAT
JME
i
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u O_
= M
o
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*S
ft-
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00
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-------
0)
S
o
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d>
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0)
a
CO
3
<0
120 -,
110-
100-
90-
80-
70-
60-
50-
-3, 40-
JC
» 30-
a.
O
5 20-
1 10-
• —
£J
- 0-
— < • i'i ii *M* .'«**'
— — — —""" """ """ '
5iS-§S?S^S^§$^^
•* *t* **•*•*•*•* *i** ***•*•*•* *!%*•*•* •*•*•* •/!*•* •*•*•* \%** ***•*•* ***t** ***•*•*•
^^^^^^^^^^^S
i$>$:$$xi::::%^
^^^^B^^^^
line of regre»«ion «- — -•
rang* of average plant data Bfrffi-fl
correlation coefficient (r): 0.106
i I i I i I I "~~™T
0 .02 .04 .06 .08 .10 .12 .14 .16
(million gallons/day)
1 1 1 1 1
0 .1 .2 .3 -4 .5 .6
(1000 cubic meters /day)
discharge
FIGURE 23
AVERAGE SUSPENDED SOLIDS AS A FUNCTION OF WHEAT
STARCH PLANT DISCHARGE VOLUME
61
-------
-------
SECTION VI
SELECTION OF POLLUTANT PARAMETERS
The waste water parameters that can te used in characterizing the
process waste waters from the cereal and wheat starch segments of
the qrain milling industry are as follows: BOD5 (5-day2C C
biocnmeiSal oxygln demand), suspended solids, PH, ^ernica! oxygen
demand (COD), dissolved solids, nitrogen, phosphorus, and
temperature. These parameters are common to the entjre industry
but are not always of equal importance. As described below the
selection of the waste water control parameters was determined by
the significance of the parameters and the availability of data
throughout each industry sutcategory.
MAJOR POLLUTANT CONTROL PARAMETERS
The following selected parameters are the most important consti-
tuSnts of cereal and wheat starch manufacturing waste waters.
Data collected during the preparation of this document, Particu-
larly from cereal plants, was limited in most cases to these
parameters. Nevertheless, the use of these parameters adequately
describes the waste water characteristics from virtually all
plants in the industry. BOD5, suspended solids, and pH are,
therefore, the parameters selected for effluent limitations
guidelines and standards of performance for new sources for these
two sutcategories.
Biochemical Qxv_gen Demand JBOJD51
Biochemical oxygen demand (BOD5) is a measure of the oxygen con-
suming capabilities of organic matter. The BOD5_ does not in
itself, cause direct harm to a water system, but it does exert an
indirect effect by depressing the oxygen content of the water.
Sewage and other organic effluents during their processes of
decomposition exert a BOD5, which can have a catastrophic effect
on the ecosystem by depleting the oxygen supply. Conditions are
frequently reached where all of the oxygen is used and the con-
tinuing decay process causes the production of noxious gases such
as hydrogen sulfide and methane. Viater with a high BOD5
indicates the presence of decomposing organic matter and subse-
guent high bacterial counts that degrade its quality and
potential uses.
Dissolved oxygen (DO) is a water quality constituent that, in
appropriate concentrations, is essential tc keep organisms living
and sustain species reproduction, vigor, and the development ot
populations. organisms undergo stress at reduced DO concentra-
tions that make them less competitive and able to sustain their
species within the aquatic environment. For example, reduced DO
concentrations have been shown to interfere with fish population
through delayed hatching of eggs, reduced size and vigor QJ.
embryos, production of deformities in the young, interference
63
-------
with food digestion, acceleration of blood clotting,, decreased
tolerance to certain toxicants, reduced food efficiency and
growth rate, and reduced maximum sustained swimming speed. Fish
food organisms are likewise affected adversely by suppressed DO.
Since all aerobic aquatic organisms need d certain amount of
oxygen, the total lack of dissolved oxygen due to a high BOD5 can
kill all inhabitants of the affected area.
If a high BOD5 is present, the quality of the water is usually
visually degraded by the presence of decomposing materials and
algae blooms due to the uptake of degraded materials that form
the foodstuffs of the algal populations.
Many cereal and wheat starch plants or the municipalities that
handle their waste waters routinely measure BCD5 in the plant
waste waters. Typical BOD5 levels are moderate to high in the
ready-to-eat cereal sutcategory, ranging from several hundred to
over 2000 mg/1. faheat starch waste waters are quite high in
BOD5, with values ranging frcm 6,000 to 14,000 mg/1 and nigher
for large plants.
Suspended Solids
Suspended solids include both organic and inorganic materials.
These materials may settle out rapidly, and bottom deposits are
often a mixture of both organic and inorganic solids. They ad-
versely 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. Deposits containing
organic materials may deplete bottom oxygen supplies and produce
hydrogen sulfide, carbon dioxide, irethane, and other noxious
gases.
In raw water sources for domestic use, state and regional
agencies generally specify that suspended solids in streams shall
not be present in sufficient concentrations 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 water for textile industries; paper and pulp;
beverages; dairy products; laundries; dyeing; photography; cool-
ing systems; and power plants. Suspended particles also serve as
a transport mechanism for pesticides and other substances that
are readily sorbed into cr onto clay particles.
Solids may be suspended in water for a time, arid then settle to
the bed of the stream 01 lake. These 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 photosynthe-tic activity of
aquatic plants.
64
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solids in suspension are aesthetically displeasing. When they
s°ttle to fcrm 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 trans-
formed to kludge deposits, may do a variety of damaging things,
including blanketing ?he stream or lake bed and thereby Destroy-
ing the living spaces for those benthic organisms that would
otherwise occupy the habitat. When of an organic and, therefore,
decomposable nature, solids use a portion or all of th« d"£*£v^
oxygen available in the area. Organic materials also serve as a
seemingly inexhaustible food source for sludgeworms and asso-
ciated organisms.
Suspended solids concentrations are rather low (100 to 40Cj jg/1)
in cereal manufacturing waste waters, but are quite high (5000 to
15,000 mg/1) in wheat starch effluents. Wet cleanup operations
that wash product spillage into the sewer account for much of the
suspended solids content of cereal waste waters. In wheat starch
was?e2, very fine starch particles pass through the refining
operation and remain in suspension. This starch accounts for
much of the organic load in the waste water and is essentially
insoluble.
2H
The term pH is a logarithmic expression of the concentration of
hydrogen ions. At a pH of 7.0, the hydrogen and hydroxyl ion
concentrations are equal and the water is neutral. If pH values
are below 7.0, acid conditions are indicated, while pH value?
above 7.0 indicate alkaline conditions.
waters with a pH below 6.0 are corrosive to water works struc-
tures, 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 7.0.
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, associated algal blooms,
and foul stenches are aesthetic liabilities of any waterway.
Even moderate changes frcm "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.
M«talocyanide 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.
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.
65
-------
The pH levels of ready-to-eat cereal plant waste waters vary over
the production day, but generally average close to 7.0. Wheat
starch waste waters tend to be acidic, in the range of 3 to 6.
pH is an essential control parameter for treatment of this waste
and regulation of the discharges.
OTHER POLLUTANT CONTROL PARAMETERS
Chemical Oxygen Demand _(COD)_
COD is a chemical measure of the organic content and, hence,
oxygen demand of the waste water constituents. As with most food
wastes, the COD of cereal and wheat starch wastes is considerably
higher than the BOD5, usually by a factor of 2.0 to 2.5. COD was
not specified as a control parameter because of the limited
availability of COD data. Due to the lack of data, no definitive
relationship between COD and BOD5 can be established at the
present time. The fact that the chemical nature of the organics
may differ from plant to plant may preclude the use of a uniform
COD standard for each subcategory. Therefore, it was concluded
that effluent limitations guidelines and standards of performance
should not be based on COD.
Solids
In natural waters, the dissolved solids consist mainly of inor-
ganic compounds including calcium, magnesium, sodium, potassium,
iron, and manganese and their associated anionic species of car-
bonates, chlorides, sulfates, phosphates, and possibly nitrates.
Many communities in the United States and in other countries use
water supplies containing 2000 to 4000 mg/1 of dissolved solids,
when no better water is available. Such waters are not very
palatable, may not quench thirst, and may have a laxative action
on new users. Waters containing more than 4000 mg/1 of total
salts are generally considered unfit for human use, although in
hot climates such higher salt concentrations can be tolerated
whereas they could not be in temperate climates. Waters con-
taining 5000 mg/1 or more are reported to be bitter and act as
bladder and intestinal irritants. It is generally agreed that
the salt concentration of good, palatable water should not exceed
500 mg/1.
Limiting concentrations of dissolved solids for fresh-water fish
may range from 5000 to 10,000 mg/1, according to species and
prior acclimatization. Some fish are adapted to living in more
saline waters, and a few species of fresh-water forms have been
found in natural waters with a salt concentration of 15,000 to
20,000 mg/1. Fish can slowly become acclimatized to higher
salinities, but fish in waters of low salinity cannot survive
sudden exposure to high salinities, such as those resulting from
discharges of oil-well brines. Dissolved solids may influence
the toxicity of heavy metals and organic compounds to fish and
66
-------
other aquatic life, primarily because of the antagonistic effect
of hardness on metals.
Waters with total dissolved solids over 500 mg/1 have decreasing
utility as irrigation water. Above 5000 mg/1 water has little or
no value for irrigation.
Dissolved solids in industrial waters can cause foaming in
boilers and cause interference with clearness, color, or taste of
many finished products. High dissolved solids concentrations
also tend to accelerate corrosion.
There are a number of sources of dissolved solids in the cereal
and wheat starch subcategories. In cereal manufacturing, these
sources include wastes from water treatment, cooling water blow-
down, and various processes, particularly cleanup, within the
plant. These sources can increase dissolved solids concentra-
tions several hundred to a few thousand mg/1. Most of these
dissolved materials are usually of an organic nature. Wheat
starch wastes contain high levels of dissolved solids, most of
which are probably unrecovered starch and gluten and thus con-
stitute a high dissolved organic load.
Temperature is one of the most important and influential water
quality characteristics. Temperature determines those species
that may be present; it activates the hatching of young, regu-
lates their activity, and stimulates or suppresses their growth
and development; it attracts, and may kill when the water becomes
too hot or becomes chilled too suddenly. Colder water generally
suppresses development; warmer water generally accelerates activ-
ity and may be a primary cause of aquatic plant nuisances when
other environmental factors are suitable.
Temperature is a prime regulator of natural processes within the
water environment. It governs physiological functions in
organisms and, acting directly or indirectly in combination with
other water quality constituents, it affects aquatic life with
each change. These effects include chemical reaction rates,
enzymatic functions, molecular movements, and molecular exchanges
between membranes within and between the physiological systems
and the organs of an anirral.
Chemical reaction rates vary with temperature and generally in-
crease as the temperature is increased. The solubility of gases
in water varies with temperature. Dissolved oxygen is decreased
by the decay or decomposition of dissolved organic substances and
the decay rate increases as the temperature of the water
increases reaching a maximum at about 30°C (86°F). The tempera-
ture of stream water, even during summer, is below the optimum
for pollution-associated bacteria. Increasing the water tempera-
67
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ture increases the bacterial multiplication rate when the
environment is favorable and the food supply is abundant.
Reproduction cycles may be changed significantly by increased
temperature because this function takes place under restricted
temperature ranges. Spawning may not occur at all because tem-
peratures are too high. Thus, a fish population may exist in a
heated area only by continued immigration. Disregarding the
decreased reproductive potential, water temperatures need not
reach lethal levels to decimate a species. Temperatures that
favor competitors, predators, parasites, and disease can destroy
a species at levels far below those that would otherwise be
lethal.
Fish food organisms are altered severely when temperatures
approach or exceed 90°F. Predominant algal species change,
primary production is decreased, and bottom associated organisms
may be depleted or altered drastically in numbers and
distribution. Increased water temperatures may cause aquatic
plant nuisances when other environmental factors are favorable.
Synergistic actions of pollutants are more severe at higher water
temperatures. Given amounts of domestic sewage, refinery wastes,
oils, tars, insecticides, detergents, and fertilizers more
rapidly deplete oxygen in water at higher temperatures, and the
respective toxicities are likewise increased.
Wnen water temperatures increase, the predominant algal species
may change from diatoms to green algae, and finally to blue-green
algae at high temperatures, because of species temperature
preferentials. Blue-green algae can cause serious odor problems.
The number and distribution of benthic organisms decreases as
water temperatures increase above 90°P, which is close to the
tolerance limit for the population. This could seriously affect
certain fish that depend on benthic organisms as a food, source.
The cost of fish being attracted to heated water in winter months
may be considerable, due to fish mortalities that may result when
the fish return to the cooler water.
Rising temperatures stimulate the decomposition of sludge, forma-
tion of sludge gas, multiplication cf saprophytic bacteria and
fungi (particularly in the presence cf organic wastes), and the
consumption of oxygen by putrefactive processes, thus affecting
the aesthetic value of a water course.
In general, marine water temperatures do not change as rapidly or
range as widely as these cf fresh^aters. Marine and estuarine
fishes, therefore, are less tolerant of temperature variation.
Although this limited tolerance is greater in estuarine than in
open water marine species, temperature changes are more important
to those fishes in estuaries and bays than to those in open
marine areas, because of the nursery and replenishment functions
68
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of the estuary that can be adversely affected by extreme
temperature changes.
Cereal plant wastes generally have temperatures ranging from 32
to U3 degrees C (90 to 110 degrees F) . Much of the increase in
temperature is due to discharge of ,-jpent cooling water and the
use of hot water in cleanup operations, As mentioned previously,
process wastes from shredded cereal cooKing range in temperature
from 71 to 77 degrees C (160 to 17 C degrees F) and can elevate
waste water temperatures at plants producing this type of cereal.
Temperature levels in wheat starch wastes range from 21 to «. /
degrees C (70 to 80 degrees F) .
During the past 30 years, a formidable case has developed for the
belief that increasing standing crops of aquatic plant growths,
which often interfere with water uses and are nuisances to man,
frequently are caused by increasing supplies of phosphorus. Such
phenomena are associated with a condition of accelerated
eutrophication or aging of waters. It is generally _ recognized
that phosphorus is not the sole cause of eutrophication, but
there is evidence to substantiate that it is frequently a key
element in stimulating excess algae growth.
Wh«n a plant population increases sufficiently to become a
nuisance, a large number of associated liabilities are
immediately apparent,. Dense populations of pond weeds make
swimming dangerous, Boating and water skiing and sometimes
fishing may be eliminated because of the mass of vegetation that
serves as a physical impediment to such activities. Plant-
populations have been associated with stunted fish populations
and with poor fishing. Excess algae growth can emit bad odors,
impart tastes and odors to water supplies, reduce the efficiency
of industrial and municipal water treatment, impair aesthetic
beauty, reduce or restrict resort trade, lower waterfront
property values, cause skin rashes to man during water contact,
and serve as a desired substrate and breeding ground for flies.
Phosphorus in the elemental form is particularly toxic, and sub-
ject to bioaccumulation in much the same way as mercury. Col-
loidal elemental phosphorus will poison marine fish (causing skin
tissue breakdown and discoloration) . Also, phosphorus is capable
of being concentrated and will accumulate in organs and soft
tissues. Experiments have shown that marine fish will _ concen-
trate phosphorus from water containing as little as 1.0 nucrogram
per liter.
Phosphorus levels in ready-to-eat cereal waste waters tend to be
quite low. Concentrations in plant effluents may be increased
somewhat by the use of detergents in plant cleanup, but levels in
the waste streams are generally too lew to present a oollutional
hazard. Limited data indicate that wheat starch wastes may con-
tain significant phosphorus concentrations, on the order of 100
69
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mg/1. This level may be necessary to achieve good biological
waste treatment, in view of the very high BOD5 concentrations
Nitrocjen
Total nitrogen levels in ready-to-eat cereal plant waste waters
are quite low, ranging from 5 up to 30 mg/1. Based on limited
data, wheat starch wastes contain higher nitrogen levels
ranging from 350 to 400 mg/1. As with the phosphorus
concentrations, these nitrogen levels based on present evidence
are required to achieve effective biological treatment. Addition
of nitrogen and phosphorus has been found necessary in effective
biological treatment of ready-to-eat cereal manufacturing wastes.
70
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SECTION VII
CONTROL AND TREATMENT TECHNOLOGY
INTRODUCTION
Since animal feed and hot cereal manufacturing plants generate no
process waste waters, there is no need to include these subcate-
gories in a discussion of control and treatment technologies.
Th~re has not been a great deal of attention given to either in-
plant control or treatment of waste waters within the ready-to-
eat cereal industry. Most of the cereal plants in the U.S.
discharge medium strength wastes to large municipal systems which
are capable of handling the industrial waste loads. Several
plants within the sutcategory provide screening and some settling
of their wastes. One plant provides biological pretreatment, and
two others are constructing pretreatment facilities to reduce
waste loadings prior to municipal discharge.
Although there has been more attention given to waste treatment
within the wheat starch industry, there has not been a great need
for development of waste control and treatment technology within
this subcategory since there are only a few plants and they all
discharge to municipal systems. One plant operates a pretreat-
ment facility and is attempting to develop a complete treatment
system. Another plant will socn construct a biological pretreat-
ment facility to reduce its organic waste loads prior to
discharge to a small municipal system.
READY-TO-EAT CEREAL MANUFACTURING
Waste Water Characteristics
As detailed in Section V, ready-to-eat cereal plants generally
produce moderate volumes of medium to high strength wastes.
Higher BOD5 concentrations result from plants that produce
shredded cereals or a high percentage of sugar-coated cereals.
Suspended solids concentrations are moderate, generally in the
range of 100 to 400 mg/1. Treatment in the industry is limited;
one known pretreatment facility and the design criteria for a
pretreatment facility presently under construction are discussed
in this section.
Since most waste waters from ready-to-eat cereal manufacturing
are generated by cleanup operations, it is not anticipated that
the raw waste characteristics can be greatly influenced by in-
plant controls. Separation and recycling of non-contact cooling
waters or increased usage of spent cooling water rather than
fresh water for such uses as cleanup would reduce waste volumes,
but not waste loadings in terms of kilograms or pounds of
pollutant per unit of production. Waste loads could be reduced
71
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in some plants if more dry-type cleanup operations, such as
sweeping or vacuuming of spillage, were employed in place of wet
washing methods.
Processes
Several plants provide minimal forms of pretreatment for their
process wastes prior to discharge to municipal systems. This
treatment usually consists of screening and occasionally settling
and skimming. Solids collected are either dried and recovered as
animal feed or disposed of by landfill.
One plant in the industry presently provides biological pretreat-
ment prior to municipal discharge. The treatment system consists
of a 0.51 hectare (1.25 acre) lagoon equipped with mechanical
aerators and designed for 30-day detention. Nutrients in the
form of ammonia and phosphoric acid are added to the high car-
bohydrate waste stream. The treatment facility handles all
process and sanitary wastes from the plant, including shredded
cereal cooking wastes. The facility was designed to handle a
flow of 379 cu m/day (0.1 MGD) , a ECD5 loading of 1135 kg/day
(25CO Ibs/day) , and a suspended solids loading of 272 kg/day (600
IDs/day) . Average influent and effluent characteristics over the
past year are given below:
Average Influent Average Effluent
______ mg/1 ______
BOD5 2500 260
COD 4300 870
Suspended Solids 300 935
Total Solids 3000 2500
pH 6.9 7.1
The high effluent suspended solids concentrations reflect the
production of biological solids dung aeration. These figures are
averages over a year's time and do not reflect seasonal fluctua-
tions which occur. During the warmer months, May through
September, effluent BOD5 values vary from 100 to 200 mg/1 , and
suspended solids vary from 550 to 800 mg/1. Corresponding BOD5
and suspended solids removals range from 92-96 percent, and zero
percent. In color weather, BOD5, concentrations increase to the
300 to 450 mg/1 range. Similarly, suspended solids during winter
vary from 900 to 1200 mg/1. BOD5 and suspended solids removals
under winter conditions ranged from 81 to 88 percent, and zero
percent. Results of a sampling program conducted during the
winter as a part of this study indicated BOD5 removals of 81 to
83 percent and an average effluent BOD5 of 450 mg/1. The
addition of a final clarifier is anticipated ro lower the
suspended solids levels within municipal ordinance limits.
72
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A second pretreatment facility is currently under construction
that will handle combined process and sanitary wastes from a
small ready-to-eat cereal plant. Presently the plant's total
waste discharge has an average BOB5 concentration of 600 irg/1 and
an average suspended solids level of 175 mg/1. The facility will
consist of two aerated lagoons in series with nutrient addition
and provisions for recycling between the two lagoons. Design is
based on an average flow of 284 cu in/day (75,000 gpd) and an
average BOD5 loading of 408 kg/day (900 Ibs/day). Anticipated
effluent quality is shown below:
Percentage
rrc^/l kg/day Ib/day Removal
BODS 200 41 90 88
Suspended solids 200 41 90 88
pH 7.5-9.0
The municipal sanitary system will continue to handle the treated
effluent.
WHEAT STARCH AND GLUTEK MANUFACTURING
Waste Water Characteristics
Waste waters from wheat starch and gluten manufacturing
operations, as described in detail in Section V, are high in
organic strength and suspended solids. Flows are moderate, in
the range of 265 to 570 cu m/day (70,000 to 160,000 gpd). pH
values are quite low, and phosphorus and nitrogen levels tend to
be high. All plants in the U.S. discharge to municipal systems
except one which uses its starch process wastes in a distillery
operation and then discharges directly to receiving waters.
Extensive treatment facilities for the distillery waste are under
construction.
In-Plant Controls
It is doubtful that any major reductions in waste loads can be
achieved through in-plant controls or modifications at existing
starch plants. Since product yield is economically crucial to
wheat starch and gluten plants, most manufacturers already
attempt to maximize solids recovery in the starch refining
operations by thickening and centrifugation. Wash down water
only amounts to between 5 and 10 percent of the total process
waste water contribution.
Two new plants will commence full scale production of wheat
starch and gluten in the near future, and both anticipate the
generation of much lower volumes of waste water than existing
plants. One plant will accomplish this by drastically reducing
water requirements, while the other hopes to employ a total
recycle system. These plants are constructed primarily for
recovery of proteinaceous material from the wheat raw material.
73
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and are suspected to employ methods and processes which may be
quite uncharacteristic as compared to historical processes.
Treatment Technology
Pretreatment operations and pilot plant studies substantially
support that the process waste water from wheat starch and gluten
manufacturing is readily biodegradable and treatable by
conventional biological treatment systems.
One pretreatment facility is in operation in the wheat starch in-
dustry, reducing the organic strength of the starch waste prior
to municipal system disposal. The facility handles 530 cu m/day
(140,000 gpd) of high-strength wastes from a medium sized starch
and gluten plant. The treatment sequence consists of a steel
mixing tank where the waste is heated to 29°C 85°F, three
anaerobic filters operated in parallel, and a chlorine contact
tank. Ammonia gas and sodium bicarbonate are continuously added
in the mixing tank to stabilize the pH between 6.5 and 7.5. The
treated waste can be recycled at rates from 0 to 100 percent.
That portion that is not recycled enters the chlorine contact
tank, where chlorine is introduced for control of odor and
potential sewer corrosion by reducing hydrogen sulfide levels.
Waste gas produced by the filters contains sufficient methane to
be combusted readily in a gas burner, and is a potential energy
source.
A comparison of average influent and effluent characteristics
during seven months of operation is shown below:
Average Influent Average Effluent
njg/1 kg/day, Ib/day.
BOD5 6500 3175 7000 2940 1406
COD 8800 4309 9500 3170 1542
Suspended Solids 2650 1270 2800 1460 703
This data indicates average reductions of 55, 64, and 45 percent
for EOD5, CCD, and suspended solJds, respectively. More recent
plant sampling indicates COD removals ranging from 18 to 59 per-
cent and averaging 33 percent over the past year, however.
One wheat starch plant has been experimenting with a full scale
complete treatment system for some time. The system employs a
vapor recompression evaporator which, in theory, should effect 98
to 99 percent solids recovery. The plant has not been able to
operate the system successfully on a continuous basis. The plant
has been operated successfully for intermittant periods of a week
or more, and experimental efforts to the process are continuing.
This type of treatment system definitely cannot yet be considered
as demonstrated technology at the present time.
74
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One other plant in the wheat starch industry is planning to con-
struct a pretreatment facility. Ihe facility will incorporate
extended aeration and final clarification after which the wastes
will be discharged to the municipal system. A chemical feed unit
will be capable of adding lime and alum to the wastes either
prior to or after aeration. Design flow is 409 cu m/day (108,000
gpd), and the detention time will be 5.0 days in the aeration
unit. Effluent BOD5 levels are estimated at 190 mg/1,
representing a 95 percent reduction. It should be emphasized
that the attainment of this effluent level has not been
demonstrated in a full scale treatment facility.
Extensive pilot plant studies were run on the starch waste prior
to design of the above pretreatment facility. The pilot system
included a 15,140 liter (4000 gallon) aeration and settling tank,
to which were later added a 1325 liter (350 gallon) rotating
biological disc and a 3217 liter (850 gallon) polishing pond.
The pilot system handled 2.7 cu m/day (720 gpd) of waste over a
five-month period. During that time, EOD5 reductions averaged 86
percent through the aeration unit alone, 88 percent through the
aeration unit and disc, and 98 percent through the entire system
including polishing pond. Average effluent BOD5 concentrations
were 680, 578, and 84 mg/1, respectively, from the three
components of the pilot treatment systeir.
75
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-------
SECTION VIII
COST, ENERGY, AND NON-WATER QUALITY ASPECTS
This chapter presents detailed cost estimates for the .various
treatment alternatives and the rationale used in developing this
information. Data have been developed for investment, capital,
operating and maintenance, depreciation, and energy costs using
various sources, including contractor's files, literature
references 6 and 9, and information from individual plants within
the industry. The cost data from industry were quite limited
and, therefore, the cost estimates are based principally on data
developed by the contractor and the references cited.
REPRESENTATIVE PLANTS
Because of the variations in plant operation, waste water
characteristics, and treatment systems, it was impractical to
select one existing plant as typical of each of the industry
subcategories. Therefore, hypothetical plants were developed (or
synthesized) for purposes of developing cost data.
In rhe ready-to-eat cereal sutcategory, there is such a wide
range of plant production capacities that it was decided to
choose three hypothetical plants of different sizes. The plant
capacities chosen were 90,700 kg/day (200,000 Ib/day), 226,800
kq/day (500,000 Ib/day), and 544,300 kg/day (1,200,000 Ib/day).
Although the waste water characteristics of ready-to-ear cereal
plants vary considerably, there is no apparent correlation with
plant capacity, as shown in Figures 14 and 15 in Section V of
this report. Thus, flow and waste water characteristics were
selected to reflect average values for existing plants in the
industry as reported in Section V.
The seven wheat starch and gluten plants exhibit a fairly narrow
range of plant capacities and waste water characteristics. A
hypothetical plant with an average daily raw material capacity of
45 360 kg (100,000 Ibs) of flour was chosen for cost estimating
purposes. Since flow and waste water characteristics are fairly-
uniform for the industry, average values for existing plants as
reported in Section V were utilized.
TERMINOLOGY
Investment Costs
Investment costs are defined as the capital expenditures required
to bring the treatment or control technology into operation.
Included, as appropriate, are the costs of excavation, concrete,
structural steel, mechanical and electrical equipment installed,
and piping. An amount equal to 15 percent of the total of the
above is added to cover engineering design services, construction
supervision, and related costs. Because most of the control
77
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technologies involve external, end-of -plant systems, no cost is
included for lost time due to installation. It is believed that
the interruptions required for installation of control
technologies can be coordinated with normal plant operating
schedules. The cost of additional land required for treatment
facilities is included, using an estimating figure of $10,000 per
acre.
SlEii^l Costs
The capital costs are calculated, in all cases, as 8 percent of
the total investment costs. Consultations with representatives
of industry and the financial community lead to the conclusion
that, with the limited data available, this estimate is
reasonable for this industry.
Depreciation
Straight-line depreciation for 20 years, or 5 percent of the
total investment cost, is used in all cases.
§Q<1 Maintenance Costs
Operation and maintenance costs include labor, materials, solid
waste disposal, effluent monitoring, added administrative
expense, taxes and insurance. When the control technology
involves water recycling, a credit of $0.30 per 1,000 gallons is
applied to reduce the operation and maintenance costs. Manpower
requirements are based upon information found in References 6 and
9. A total salary cost of $10 per man-hour is used in all cases.
and Power Costs
Power costs are estimated on the basis of $0.025 per kilowatt-
hour.
Annual costs are defined as the total of capital costs,
depreciation, operation and maintenance, and energy and power
costs as accrued on an annual basis.
COST INFORMATION
The investment and annual costs, as defined above, associated
with the alternative waste treatment control technologies are
presented below. In addition, a description of each of the
control technologies is provided, together with the effluent
quality expected from the application of these technologies. All
costs are reported in terms of August, 1971 dollars.
E§§dy_-to-Eat Cereal Manufacturing
As a basis for developing control and treatment cost information,
three different ready-to-eat cereal plants were synthesized to
cover the broad range of plant capacities within the industry.
78
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The waste water characteristics used to describe these plants
reflect actual industry practice based on average data received
from existing plants. The values employed are as follows:
Flow
BOD5
Suspended Solids
2.7 liters/lb of cereal (0.7 gal/lb)
6.6 kg/kkg (lbs/1000 Ibs) or 1130 rng/1
1.4 kg/kkg (lbs/1000 Ibs) or 240 mg/1
The production and waste water characteristics of the three
hypothetical cereal plants are summarized below:
Plant A:
Production
Flow
BOD5
Suspended Solids
Plant B:
Production
Flow
BOD
Suspended Solids
Plant C:
Production
Flow
BOD5
Suspended Solids
90,700 kg/day (200,000 Ib/day)
529 cu m/day (140,000 gpd)
635 kg/day (1400 Ib/day
127 kg/day (280 Ib/day)
226,800 kg/day (500,000 Ib/day)
1325 cu m;day (350,000 gpd)
1588 kg/day (3500 Ib/day)
318 kg/day (700 Ib/day)
544,300 kg/day (1,200,000 Ib/day)
3179 cu m/day (840,000 gpd)
3810 kg/day (8400 Ib/day)
762 kg/day (1680 Ib/day)
A number of alternative treatment systems are proposed below to
handle the waste waters from these plants. These systems are
presented in terms of increasing effluent quality. The
investment and annual cost information for each alternative, and
the resultant effluent qualities are presented in Tables 8, 9,
and 10 for the three hypothetical ready-to-eat cereal plants.
79
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CO
o
Alternative Treatment or
Table 8
Water Effluent Treatment Costs
Small Ready-to-Eat Cereal Plant
(90,700 kg/day)
(Thousands of Dollars)
Control Technologies : A_
Investment Costs $1*1*8.9
Annual Costs :
Capital Costs 35-9
Depreciation 22. 1*
Operating and Maintenance Costs 1*5.2
Energy and Power Costs 10.6
Total Annual Cost 11 IK 1
Effluent Quality:
RaV
Waste
Parameters Units Load
BOD kg/kkg 7.0 0.58
Suspended Solids kg/kkg 1.1* 0.58
BOD mg/1 X200 100
Suspended Solids mg/1 2UO 100
Dissolved Solids mg/1
B_
527.9
1*2.2
26.U
1*6.1*
11.6
126.6
C_
629.9
50. h
31.5
U7.9
11.6
lUl.U
Resulting
D_
563.3
U5.1
28.2
53A
12.6
139-3
Effluent
E
777-5
62.2
38.9
68.1*
16.6
186.1
I
960.7
76.9
1*8.0
86.2
22.6
233.7
Levels
O.M*
0.1*1*
75
75
-
0.18-0.35
0.18-0.35
30-60
30-60
-
0.12-0.18
0.06-0.12
20-30
10-20
-
0.03
0.03
5
5
-
0.03
0.03
5
5
500
-------
oo
Table 9
¥ater Effluent Treatment Costs
Medium-Sized Ready-to-Eat Cereal Plant
C226,800 kg/day)
(Thousands of Dollars)
,H_L OCX I1CLUX V C X X c a OX11C1.L U wx
Control Technologies
Investment Costs
Annual Costs :
Capital Costs
Depreciation
Operating and Maintenance Costs
Energy and Power Costs
Total Annual Cost
Effluent Quality:
Raw
Waste
Parameters Units Load
BOD kg/kkg 7.0
Suspended Solids kg/kkg I.k
BOD mg/1 1200
Suspended Solids mg/1 2kO
Dissolved Solids mg/1
A
$686 A
5^.9
3k.3
67.9
22.0
179.1
BP
\j
811.8 887.2
6k. 9 71.0
1*0.6 kk.k
70.0 71.8
23.7 23.7
199.2 210.9
Resulting
D_
875.3
70.0
US. 8
83-9
25. k
223.1
Effluent
E_
12^7 . 3
99-8
62. U
109-9
32.3
30k. h
L
1613.5
129.1
80.7
1U2.1
U2.7
39U.6
Levels
0.58
0.58
100
100
-
O.kk 0.18-0.35
O.kk 0-18-0.35
75 30-60
75 30-60
_
0.12-0.18
0.06-0.12
20-30
10-20
-
0.03
0.03
5
5
-
0.03
0.03
5
5
500
-------
CD
Table 10
Water Effluent Treatment Costs
Large Ready-to-Eat Cereal Plant
(5^,300 kg/day)
Alternative Treatment or
(Thousands of Dollars)
Control Technologies A
Investment Costs $1062.1
Annual Costs :
Capital Costs
Depreciation
Operating and
85.0
53.1
Maintenance Costs 96.7
Energy and Power Costs kk.9
Total Annual Cost 279.7
Effluent Quality
Parameters
BOD
Suspended Solids
BOD
Suspended Solids
Dissolved Solids
:
Raw
Waste
Units Load
kg/kkg 7.0 0.58
kg/kkg lA 0.58
mg/1 1200 100
mg/1 2^0 100
mg/1
B
1277.5
102.2
63.9
100.3
U7.8
31^.2
c_
115.3
72.1
102.7
1+7.8
337.9
Resulting
iiai.7
112.9
70.6
123.2
50.7
359-9
Effluent
E_
163.3
102.0
167.1
62A
U9U.8
L
2785.5
222.8
139.3
237-3
80.0
679 .U
Levels
Q.kk
o.UU
75
75
—
0.18-0.35
0.18-0.35
30-60
30-60
_
0.12-0.18
U. 06-0. 12
20-30
10-20
_
0.03
0.03
5
5
_
0.03
0.03
5
5
500
-------
Figure 24 graphically depicts the investment costs of the six
treatment alternatives as a function of cereal plant capacity.
The specific treatment technologies are described in the follow-
ing paragraphs.
Alternative A — Activated Sludge
This alternative provides for grit removal, nutrient addition,
primary sedimentation, complete-mix activated sludge, secondary
sedimentation, chlorination, and solids dewatering. The treat-
ment system does not include equalization. Effluent BOD5 and
suspended solids concentrations are expected to be about 100
mg/1. In terms of plant production, these values correspond to
0.58 kg/kkg (lbs/1000 Ibs) for BOD5 and for suspended solids.
Investment Costs: Plant A $ 448.90C
Plant B $ 686,400
Plant C $1,062,100
Total Annual Costs: Plant A $ 114,100
Plant E $ 179.100
Plant C $ 279.700
Reduction Benefits: BOD5 reduction of 92 percent and
suspended solids reduction of 59 percent.
Alternative B — Equalization and Activated Sludge
Alternative B includes an aerated equalization step with 18-hour
detention ahead of the complete-mix activated sludge system and
associated chemical feed, sedimentation, and sludge dewatering
facilities outlined in Alternative A. Estimated BOD5 and sus-
pended solids levels are 75 mg/1 for each parameter. This value
corresponds to 0.44 kg/kkg (lbs/1000 Ibs) of BOD5 and suspended
solids.
Investment Costs: Plant A $ 527,900
Plant B $ 811,800
Plant C $1,277,500
Total Annual Costs: Plant A $ 126,600
Plant B $ 199,200
Plant C $ 314.200
Reduction Benefits: BOD5 reduction of 94 percent
and suspended solids reduction of 69 percent.
Alternative C -- Equalization, Activated Sludge, and
Stabilization Basin
This alternative adds a stabilization basin or lagoon after the
secondary sedimentation step of the preceding treatment system.
Alternative B. This lagoon will provide 10-day detention for
83
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3000-,
2500-
2000
1500-
1000-
0)
500-
= 0
0 200
(1000 Ib./day)
400
600
800 1000 1200
0 100
(1000 kg/day)
plant capacity
200
300
400
500
FIGURE 24
COST OF TREATMENT ALTERNATIVES VERSUS
CEREAL PLANT CAPACITY
-------
stabilizing the remaining BOD5 and reducing the suspended solids
concentration. Effluent levels of 30 to 60 mg/1 of BOD5 and
suspended solids are expected from Alternative C. Resultant
waste loads per unit of production will be 0.18 to 0.35 kg/kkg
(lbs/1000 Ibs) for both BOD5 and suspended solids.
Investment Costs:
Total Annual Costs:
Plant A
Plant B
Plant C
Plant A
Plant E
Plant C
$ 629,900
$ 887,200
$1,44 1,500
$ 141,400
$ 210,900
$ 337,900
Reduction Benefits: BOD5 reduction of 95 to 97.5
percent and suspended solids reduction of 75 to 67 percent.
Alternative D — Equalization, Activated Sludge, and Deep Bed
Filtration
Alternative D includes deep bed filtration with the treatment
steps proposed in Alternative B. BOD5 concentrations are antici-
pated to be 20 to 30 mg/1 in the effluent and suspended solids
are expected to be 10 to 20 mg/1. These concentrations
correspond to effluent waste loads of 0.12 to 0.18 kg/kkg
(lbs/1000 Ibs) of EOD5 and 0.06 to 0.12 kg/kkg (lbs/1000 Ibs) of
suspended solids.
Investment Costs:
Plant A
Plant B
Plant C
$ 563,300
$ 875,300
$1,411,700
Total Annual Costs: Plant A
Plant B
Plant C Plant C
$
$
$
139,300
223,100
359,900
Reduction Benefits: BOD5 and suspended solids reduc-
tions of 97.4 to 98.3 percent and 91.4 to 95.7 percent,
respectively.
Alternative E — Equalization, Activated Sludge, Deep Bed
Filtration, and Activated Carbon Filtration
In Alternative E, activated carbon filtration is added to the
previous treatment scheme. The effluent concentrations are
estimated to be 5 mg/1 for both BOD5 and suspended solids. This
level corresponds to waste loads of 0.03 kg/kkg (lbs/1000 Ibs)
for both BOD5 and suspended solids.
Investment Costs:
Plant A
Plant B
Plant C
Total Annual Costs: Plant A
$ 777,500
$1,247,300
$2,040,900
$ 186,100
85
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Plant B $ 304,400
Plant C $ 494,800
Reduction Benefits: BOD5 and suspended solids
reductions of 99.6 and 97.9 percent, respectively.
The effluent should be suitable for partial
reuse or recycle.
F — Equalization, Activated Sludge, Deep Bed
Filtration, Activated Carbon Filtration, and Reverse
Osmosis
This alternative includes reverse osmosis to reduce the total
dissolved solids. Effluent levels will be comparable to those
anticipated in Alternative E, but with a maximum dissolved solids
concentration of 500 irg/1.
Investment Costs: Plant A $ 960,700
Plant B $1,613,500
Plant C $2,785,500
Total Annual Costs: Plant A $ 233,700
Plant B $ 394,600
Plant c $ 679,400
Reduction Benefits: BOD5 and suspended solids
reductions equal to those expected in Alternative E,
i.e., 99.6 and 97.9 percent, respectively. The
effluent should be suitable for complete recycle.
Wheat Starch and Gluten Manufacturing
A hypothetical wheat starch and gluten plant of moderate size,
i.e., 45,360 kg/day (100,000 Ibs/day) of wheat flour input, was
selected as a basis for developing cost data. The values of the
waste water characteristics used to describe this plant reflect
actual industry practice, as follows:
Flow 4.5 cu m/kkg (1.2 gal/lb) of flour
BCD5 90.7 kg/kkg (lbs/10CO Ibs)
Suspended Solids 75.2 kg/kkg (lbs/1000 Ibs)
The production and waste water characteristics of the
hypothetical plant are summarized below:
Production 45,360 kg/day (100,000 Ibs/day)
Flow 454 cu m/day (120,000 gpd)
BOD5 4114 kg/day (9070 Ibs/day) or 9057 mg/1
Suspended Solids 3411 kg/day (7520 .bs/day) or 7509 mg/1
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Proposed alternative treatment systems are described below. The
investment and annual cost information for each alternative and
the resultant effluent qualities are presented in Table 11.
Alternative A — Activated Sludge
This first alternative includes pH neutralization, primary sedi-
mentation, complete-mix activated sludge, secondary
sedimentation, effluent chlorination, and sludge dewatering.
Anticipated effluent levels are 200 to 400 mg/1 of BOD5 and 100
to 400 mg/1 of suspended solids. These levels correspond to
waste loads of 2.0 to 4.0 kg/kkg (lbs/1000 Ibs) of BOD5 and 1.0
to 4.0 kg/kkg (lbs/1000 Ibs) of suspended solids.
Investment Cost: $ 892,500
Total Annual Cost: $ 240,700
Reduction Benefits: BOD5 reduction of 95.6 to 97.8
percent, suspended solids reduction of 94.7 to 98.7
percent.
Alternative B — Equalization and Activated Sludge
This alternative includes 18 hours of aerated equalization ahead
of the complete-mix activated sludge system described in Alterna-
tive A. Average effluent levels are estimated at 150 to 300 mg/1
for BCD5 and 100 to 300 mg/1 for suspended solids. These concen-
trations represent waste loads of 1.5 to 3.0 kg/kkg (lbs/1000
Ibs) for BOD5 and 1.0 to 3.0 kg/kkg (Its/1000 Ibs) for suspended
solids.
Investment Cost: Incremental costs are approximately
$71,800 over Alternative A for a total cost of $964,300.
Total Annual Cost: Incremental costs are approximately
$11,500 over Alternative A for a total annual cost of
$252,200.
Reduction Benefits: BOD5 reduction of 96.7 to 98.3
percent and suspended solids reduction of 96.0 to 98.7
percent.
Alternative^ — Equalization, Activated Sludge, and
Stabilization Lagoon
Alternative C adds a stabilization basin with 10-day retention to
the preceding treatment system. BOD5 levels in the effluent are
anticipated to be 100 to 150 mg/1, and suspended solids levels of
75 to 150 mg/1 are expected. These values correspond to 1.0 to
1.5 kg/kkg (lbs/1000 Ibs) for BOD5 and 0.75 to 1.4 kg/kkg (lbs/1000
Ibs) for suspended solids.
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co
Table 11
Water Effluent Treatment Costs
Typical Wheat Starch and Gluten Plant
Alternative Treatment or
(Thousands of Dollars)
Control Technologies :
Investment Costs
Annual Costs :
Capital Costs
Depreciation
Operating and
Maintenance Costs
Energy and Power Costs
Total
Effluent Quality
Parameters
BOD
Suspended Solids
BOD
Suspended Solids
Dissolved Solids
Annual Cost
Raw
Waste
Units Load
kg/kkg 90.7
kg/kkg 75-2
mg/1 9070
mg/1 7520
mg/1
A
$892 . 5
71.4
44.6
86.3
38.4
240.7
2.0-4.0
1.0-4.0
200-400
100-400
-
B_
964.3
77.1
48.2
87.5
39.4
252.2
1.5-3.0
1.0-3.0
150-300
100-300
-
c_ p_
1014.6 996.0
81.2 79.7
50.7 49.8
88.9 94.1
39.4 40.4
260.2 264.0
Resulting Effluent
Levels
1.0-1.5 0.3-0.5
0.75-1.5 0.2-0.3
100-150 30-50
75-150 20-30
- _
E_
1191.7
95-3
59.6
107.9
44.4
307.2
0.05-0.15
0.05-0.15
5-15
5-15
_
F
1350.4
108.0
67.5
127.6
50.4
353.5
0.05
0.05
5
5
500
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Investment Costs: Incremental costs of $50,300
over Alternative B for a total cost of $1,014,600.
Total Annual Costs: Incremental costs of $8000
over Alternative B for a total cost of $260,200.
Reduction Benefits: BOD5 reduction of 98.3 to 98.9
percent, suspended solids reduction of 98 to 99 percent.
Alternative D — Equalization, Activated Sludge, and Deep Bed
Filtration
In this proposed system, deep bed filtration is added to the
treatment system outlined in Alternative B. The stabilization
lagoon is deleted. BOD5 and suspended solids effluent levels of
30 to 50 mg/1 and 20 to 30 mg/1, respectively, are anticipated
These concentrations represent 0.3 to 0.5 kg/kkg (lbs/1000 Ibs)
of BOD5 and 0.2 to 0.3 kg/kkg (lbs/1000 Ibs) of suspended solids.
Investment Costs: Incremental costs of $31,700
over Alternative B for a total cost of $996,000.
Total Annual Costs: Incremental costs of $11,800
over Alternative B for a total cost of $264,000.
Reduction Benefits: BOD5 reduction of 99.4 to 99.7
percent, suspended solids reduction of 99.6 to 99.7
percent.
Alternative E — Equalization, Activated Sludge, Deep Bed
Filtration, and Activated Carbon Filtration
For Alternative E, activated carbon filtration is added to the
previous treatment system in Alternative D. Effluent concentra-
tions of 5 to 15 mg/1 are expected for both BOD5 and suspended
solids. These levels correspond to 0.05 to 0.15 kg/kkg (lbs/1000
Ibs) for both parameters.
Investment Costs: Incremental costs of $195,700
over Alternative D for a total cost of $1,191,700.
Total Annual Costs: Incremental costs of $43,200
over Alternative D for a total cost of $307,200.
Reduction Benefits: BODjj and suspended solids
reductions of 99.8 to 99.9 percent. The effluent
should be suitable for at least partial recycle.
Alternative F — Equalization, Activated Sludge, Deep Bed
Filtration, Activated Carbon Filtration, and Reverse
Osmosis
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This alternative includes reverse osmosis to reduce the total
dissolved solids. Effluent levels cf 5 mg/1 tor both BOD5 and
suspended solids are anticipated, with a maximum dissolved solids
concentration of 500 mg/1.
Investment Costs: Incremental costs of $158,700
over Alternative E for a total cost of $1,350,400.
Total Annual Costs: Incremental costs of $46,300
over Alternative E for a total cost of $353,500.
Reduction Benefits: BOD 5 and suspended solids
reductions of 99.9 percent. The effluent should be
suitable for coirplete recycle.
NON-WATER QUALITY ASPECTS OF TREATMENT AND CONTROL TECHNOLOGIES
Pollution Control
With the proper operation of the types of biological treatment
systems presented earlier in this section, no significant air
pollution problems should develop. Since the waste waters from
the breakfast cereal and wheat starch segments of the grain
milling industry have a high organic content, however, there is
always the potential for odors. Various methods of odor control
are available and have been extensively applied in the biological
treatment of waste water. These methods include aeration,
chorination, lime and other chemical addition, odor masking
agents, and modified operating procedures. Odors as they may
result from biological treatment of wheat starch and ready-to-eat
cereal waste are technological control. No significant odors
would result above existing conditions. Care should be taken in
the section, design, and operation of biological treatment
systems to prevent anaerobic conditiors and thereby eliminate
possible odcr problems.
Solid Waste Disposal
The treatment of waste waters from cereal and wheat starch plants
will give rise to substantial quantities of solid wastes, par-
ticularly biological solids from activated sludge or comparable
systems. Conventional methods for handling biological solids are
applicable to these wastes such as digestion, dewatering, land-
fill, or incineration. Disposal of this solid material as not to
contribute to pollution of ground or surface waters is necessary.
The treatment technologies presently in use or proposed in this
document do not require any processes with exceedingly high
energy requirements. Power will be needed for aeration, pumping,
centrifugaticn, and other unit operations. These requirements,
generally, are a direct function of the volume treated and the
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waste strength. Thus, the greatest energy demands will occur in
large ready-tc-eat cereal plants.
For the hypothetical treatment systems described previously in
this section, the power requirements are in the range of 75 to
370 kw (100 to 500 hp) for cereal plants and 150 to 220 kw (200
to 300 hp) for wheat starch plants. This level of demand is
generally less than one percent of the total energy requirements
of a typical ready-to-eat cereal or wheat starch plant. It was
concluded that the energy needs for achieving needed waste water
treatment constitute only a small portion of the energy demands
of the entire industry, and these added demands can readily be
accommodated by purchased and in-house power sources.
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SECTION IX
EFFLUENT DEDUCTION ATTAINABLE THROUGH THE APPLICATION OF
THE BEST PRACTICABLE CONTROL TECHNOLOGY CURRENTLY AVAILABLE
EFFLUENT LIMITATIONS GUIDELINES
INTRODUCTION
The effluent limitations that must te achieved by July lf 1977
are to specify the degree of effluent reduction attainable
through the application of the best practicable control
technology currently available. The best practicable control
technology currently available is generally based upon the
averages of the best existing performance by plants of various
sizes, ages, and unit processes within the industrial category or
subcategory. This average is not based on a broad range of
plants within the grain milling industry, but on performance
levels achieved by a combination of plants showing exemplary in-
house performance and those with exemplary end-of-pipe control
technology.
Consideration must also be given to:
a. the total cost of application of technology in relation
to the effluent reduction benefits to be achieved from
such application;
b. the size and age of equipment and facilities involved;
c. the processes employed and product mix;
d. the engineering aspects of the application of various
types of control techniques;
e. process changes; and
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 of installation of the control facilities. However,
where pollution control and abatement technology as presently
applied in an industry is judged inadequate, effluent limitation
guidelines for the industry category or subcategory may be based
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upon the transfer of technology to reasonably achieve the
effluent limitations and standards as established.
In establishing the level of technology and effluent limitation
guidelines for the breakfast cereal, and wheat starch segment of
the point source category, it is recognized that present plants,
with only few exceptions, discharge the untreated or partially
treated waste water to municipal sewage systems. Therefore,
since no direct discharge to navigable waters result from the
operation of industry-owned treatment measures, effluent
guidelines would have no direct application in these instances.
However, the need for effluent guidelines for the ready-to-eat
cereal and wheat starch manufacturing subcategories is evident
where any plant modifications or changes in existing practices
would result in discharge of process waste waters directly to
navigable waters.
EFFLUENT DEDUCTION ATTAINABLE THROUGH THE APPLICATION OF BEST
PRACTICABLE CONTROL TECHNOLOGY CURRENTLY AVAILABLE
Based on the information presented in Sections III through VIII
of this report, it has been determined that the effluent reduc-
tions attainable through the application of the best practicable
control technology currently available for these subcategories
are those presented in Table 12. These values represent the
maximum allowable waste water effluent loading for any 30
consecutive calendar days. Excursions above these levels are to
be permitted with a maximum daily average of 3.0 times the
average 30-day values listed below. The variances for maximum
daily average are necessary to consider variation in production,
plant operation, shock waste loads, and variable waste
contributions .
Table 12
Effluent Reduction Attainable Through the Application of
Best Practicable Control Technology Currently Available*
EOD5 Suspended Solids p_H
Subcatecjory ]
-------
IDENTIFICATION OF BEST PRACTICABLE CONTROL TECHNOLOGY CURRENTLY
AVAILABLE
The best practicable control technology currently available for
th* sutcategories of the grain milling industry covered in this
document generally consists of equalization, biological treatment
(e.g. activated sludge) , and effective solids separation. The
specific technological means available to implement the specified
effluent limitations are presented below for each subcategory.
Aniffi^I E§§3 Manufacturing
Animal feed manufacturing requires little process water and
generates no waste waters. Hence, the effluent limitation of no
discharge of process wastes is already being met.
Hot Cereal Manufacturing
The manufacture of hot cereals generates no process wastes.
Thus, the effluent limitation of no discharge of process wastes
is already being met.
Ready. -to- Eat Cereal Manufacturing
Waste waters from ready-to-eat cereal plants are generated
primarily in cleanup operations. Although waste volumes can be
reduced by in-plant modifications, substantial reduction in the
waste load from the plant is not an immediate possibility and
treatment of the entire waste stream is necessary. Treatment
includes :
1. Collection and equalization of flow
2. Primary sedimentation
3. Nutrient addition
U. Biological treatment using activated sludge or a
comparable system
5. secondary sedimentation.
6. Additional biological treatment and/or solids removal
Wheat Starch and Gluten Manufacturing
Wheat starch manufacturing plants generate moderate volumes of
high strength waste waters. Substantial reductions in the total
waste load by means of in-plant modifications are not presently
practical under present manufacturing methods, and treatment of
the entire waste stream is required as follows to meet the
effluent limitations:
95
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1. Collection and equalization of flow
2. pH neutralization
3. Primary sedimentation
4. Biological treatment using activated sludge or a
comparable system
5. Final separation of solids by sedimentation prior
to discharge. Addition filtration may be required
or desirable.
RATIONALE FOR THE SELECTION Of EEST PRACTICABLE CONTROL
TECHNOLOGY CURRENTLY AVAILABLE
Animal H§§d Manufacturing
Since no process waste waters are generated in the manufacture of
animal feed, an effluent limitation of no discharge is specified.
Hp_£ Cereal Manufacturing
As with animal feed manufacturing, no waste waters are generated
in the manufacture of hot cereal, and again an effluent
limitation of no discharge is specified.
Cereal Manufacturing
of Application
Data developed on the cost of applying various treatment tech-
nologies are presented in Section VIII. Costs were developed for
three ready-to-eat cereal plants of different sizes. For a small
plant producing 90,700 kg/day (200,000 Ibs/day) , the investment
cost for implementing the best practicable control technology
currently available is about $527,900 and the total annual cost
is $126,600. For a mediuir sized plant producing 226,800 kg/day
(500,000 Ibs/day) , the investment cost is $811,800 and the total
annual cost is $199,200. For a large plant producing 544,300
kg/day (1,200,000 Ibs/day), the investment cost is $1,277,500 and
the total annual cost is $314,200.
Si^e of Production Facilities
The plants in this subcategory range in age from four to over 70
years. The chronological age of the original buildings, however,
does not accurately reflect the degree of modernization of the
production facilities. Periodic changes in the types of cereal
produced frequently involve new production methods and equipment.
As a result, it is not possible to differentiate between the
basic production operations at the various plants on the basis of
age.
96
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Similarly, waste water characteristics from the ready-to-eat
cereal plants cannot be classified according to plant age. Of
the newer plants, several generate low raw waste loads in terms
of BODS and suspended solids per unit of product and several
yield rather high waste. loads. At the same time, several older
plants have low raw waste loads. The data graphically presented
in Section V clearly demonstrate the absence of any practicable
and reliable correlation based on plant age. Accordingly, it is
concluded that the age of the plant is not a direct factor in
determining the best practicable control technology currently
available.
The size of the plant does have a direct influence as expected on
the total amounts of contaminants discharged. In general, the
larger the plant the greater the waste load. The effluent
limitations presented herein have been developed in terms of unit
of finished product, i.e., kg/kkg or lbs/1000 Ibs of cereal, in
order to reflect the influence of plant size. The control
technologies discussed in Section VIII, however, are applicable
to all plants regardless of size.
Processe
Although the manufacturing processes employed in ready-to-eat
cereal plants vary depending on the type of cereal being
produced, the basic unit processes are standard across the
industry. These unit processes, as discussed in Section IV,
includeemixangams combinations of mixing, cooking, extrusion,
flaking, shredding, puffing, toasting, and packaging. Production
processes within the industry do not provide a basis for
subcategorization, nor are they a factor in determining the best
practicable control technology currently available.
Product Mix
As mentioned previously in describing the ready-to-eat cereal
industry, a wide variety of different types of cereal is produced
at the various plants throughout the country. Furthermore, the
product mix at a given plant may vary significantly on a monthly,
weekly, and even daily basis. Attempts were made to correlate
raw waste loads with type of cereal produced, such as flaked,
puffed, extruded, coated, and non-coated. The available data did
not indicate a correlation between waste loads and variation in
product mix. One possible relationship was indicated, that being
the variation of organic waste load with the percentage of
cereals being sugar-coated, but this relationship could not be
quantitatively defined and in practice would be administratively
difficult to interpret. There is no evidence to suggest that the
waste waters generated from any specific cereal manufacturing
process so affect the character of the total plant waste stream
as to substantially reduce the ability of the plant to implement
the best practicable control technology currently available.
Engineer ina Aspects of Application
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The engineering feasibility of achieving the effluent limitations
using the technology discussed has been examined. None of the
ready-to-eat cereal plants provide extensive waste water
treatment with discharge directly to the receiving waters. The
best practicable control technology currently available does not
represent current practice of any cereal plant. All plants
presently discharge their process waste water, with or without
partial treatment, to municipal sewage systems with one
exception. _ The one plant now discharging directly to receiving
waters anticipates connection to a municipal sewage system in the
near future. The availability of municipal systems has not
necessitated the development and the application of available
treatment measures for specific use in the ready-to-eat cereal
industry. The technology as presently demonstrated in the
industry is inadequate, and transfer of technology for similar
wastes is appropriate. The effectiveness of these technologies
for treatment of ready-to-eat cereal waste has been
satisfactorily indicated through pilot plant and prototype
operations as described in Section VII of this document. Data
from one pretreatment plant clearly indicate that this type of
waste water is amenable to biological treatment. Accordingly,
the treatment technology recommended is considered to be a
practicable means for achieving the specific effluent
limitations. The treatment technology is readily available. On
an overall industry basis, these effluent limitations will result
in a BOD5 reduction of approximately 95 percent and a suspended
solids reduction of about 69 percent.
Based on present waste water volumes in the industry, the average
treated effluent resulting from the application of these effluent
limitations will contain about 75 mg/1 of BODS and suspended
solids. ~~
Non- Water Quality Environmental Impact
In terms of the non-water quality environmental impact, the only
item of possible concern is the increased energy consumption to
operate the waste water treatment facilities. Relative to the
production plant energy needs, this added load is small and not
of significant impact. For example, the power requirements for
waste handling and disposal in the application of the best
practicable control technology currently available to a medium
sized ready-to-eat cereal plant are estimated to be 100 kilowatts
(135 hp) . This demand represents less than one percent of the
plant's total power usage.
Wh.e_§;t Starch and Gluten Manufacturing
£°.§t of Application
The investment and annual costs for implementing various control
technologies were presented in Section VIII. To implement the
best practicable control technology currently available in order
-co meet the specified effluent limitations, the costs for a
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typical medium sized wheat starch plant were estimated to be
$964,300 for investment and $252,200 in total annual costs.
M§ and Size of Production Facilities
The plants in this subcategory range in age from three to over 3C
years. As with the cereal industry, the age of the original
plant building does not, however, reflect the degree of moderni-
zation of the production facilities. Since the plants
continually incorporate new production techniques, no reliable
generalizations between the basic production operations employed
at various plants and the age of the plant can be made.
Available data indicates a possible relationship between plant
age and raw waste loads. On the basis of Figures 17 and 18 in
Section V, BOD5 and suspended solids loads show some correlation
with wheat starch plant age, and a general trend of increasing
waste loads with increasing age was indicated. It is important
however to note that the elder wheat starch plants also tend to
be it may be reasonably concluded that the larger plants. Thus,
the indicated correlations may be strongly influenced by other
factors the most important of which is likely plant capcity.
The size of the plant as expected has a direct influence upon the
total amounts of contairinants discharged. The effluent
limitations presented herein for the wheat starch and gluten
manufacturing subcategory have been developed in terms of unit of
raw material input, i.e., kg/kkg or lbs/1000 Ibs of wheat flour,
in order to reflect the influence of plant size. Available data
does indicate a possible relationship between suspended solids
and plant size or capacity, but no relationship between BOD5 and
plant size. A narrow range of raw waste load values exists per
unit of raw material input. The control technologies discussed
in Section VIII are judged applicable to all wheat starch plants
regardless of size.
lD2iQeerincj Aspects of Application
As with the ready-to-eat cereal subcategory, none of the wheat
starch and gluten plants provide extensive waste water treatment
with direct discharge to receiving waters. One wheat starch and
gluten manufacturing plant does provide substantial pretreatmerit
of the plant waste water prior to discharge to a municipal sewage
system. The best practicable control technology currently
available does not represent the current practice at any wheat
starch and gluten manufacturing plant. As noted previously,
current practice is to discharge the process waste water, either
without treatment or with partial treatment, to municipal sewage
systems. Because of the proximity to municipal systems and the
ready acceptance of this waste by municipal facilities, a great
deal of research and experimentation for separate treatment of
wheat starch and gluten manufacturing wastes has not been
necessitated. Specific application for treatment of wheat starch
wastes has been principally limited to one operational
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pretreatment facility and pilot plant study. The technology as
currently demonstrated in the industry is inadequate where direct
discharge of process 'waste waters to navigable waters may result.
Under the circumstances, a transfer of technology is establishing
effluent limitations is appropriate.
Available information from full-scale pretreatment, and pilot
plant studies firmly establishes the ready biodegradability of
the wastes without the addition of nutritional additions.
Present knowledge of waste treatability and efficiency of removal
of pollutants with available unit process waste water treatment
sequences, reasonably establishes the predictability of overall
pollutant removal efficiency to be attained through additional
and/or alternate physical, chemical, and biological treatment
processes.
The transfer of technology ahs been adopted on the basis of
anticipated end-of-pipe treatment of process waste water, even
though it is well recognized that in-plant control measures
(water conservation and waste water recycling) and land
application has promises of offering a practical and effective
means of waste load reduction in many instances, and may
effectively complement end-of-pipe treatment measures. High
pollutant reduction levels (BOD5 and suspended solids) are
necessitated particularly in the wheat starch and gluten
manufacturing subcategory because of the extrmeely high initial
raw waste lead characteristic of this industry. Technology
exists to effectively reduce the effluent load limitations to the
specific level. Attainment of this level of technology is judged
practical, and is currently available. The final effluent
concentrations to be realized by applying the specified control
technologies will be about 200 mg/1 of EOD5 and suspended solids.
Non-Water Duality, IfflESCt-
The non-water quality environmental impact is restricted to the
increased power consumption required for the treatment facility.
This power consumption is quite small compared to the total
energy requirements for a wheat starch plant and, therefore, the
impact of the control facilities is considered insignificant.
LIMITATIONS CN THE APPLICATION OF THE EFFLUENT LIMITATIONS
GUIDELINES
The effluent limitation guidelines presented above can generally
be applied to all plants in each subcategory of the grain milling
industry covered in this report. Special circumstances in indi-
vidual plants, however, may warrant careful evaluation.
Also, it must be recognized that the treatment of high strength
carbohydrate wastes, notably from wheat starch plants, is diffi-
cult. Upset conditions may cccur that result in higher BOD5 and
suspended solids discharges than normal. While the treatment
sequence defined as best practicable control technology currently
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available will minimize these upsets, they may still occur. The
allowance in the effluent limitations guidelines to reflect
maximum daily values properly considers the momentary variations
in waste load and treatment efficiency which are expected to
occur.
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SECTION X
EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION OF
THE BEST AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE
EFFLUENT LIMITATIONS GUIDELINES
INTRODUCTION
The effluent limitations that must be achieved by July 1, 1983
are to specify the degree of effluent reduction attainable
through the application of the best available technology economi-
cally achievable. This control technology is not based upon an
average of the best performance within an industrial category,
but is determined by identifying the very best control and
treatment technology employed by a specific plant within the
industrial category or sutcategory, or readily transferable from
one industry process to another.
Consideration must also be given to:
a. the total cost of application of this control technology
in relation to the effluent reduction benefits to be
achieved 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 this
control technology;
e. process changes;
f. non-water quality environmental impact (including energy
requirements).
Best available technology economically achievable also considers
the availability of in-process controls as well as end-of-process
control and additional treatment techniques. This control tech-
nology is the highest degree that has been achieved or has been
demonstrated to be capable of being designed for plant scale
operation up to and including "no discharge" of pollutants.
Although economic factors are considered in this development, the
costs for this level of control are intended to be the top-of-
the-line of current technology subject to limitations imposed by
economic and engineering feasibility. However, this control
technology may be characterized by some technical risk with
respect to performance and with respect to certainty of costs.
Therefore, this control technology may necessitate some
industrially sponsored development work prior to its application.
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In establishing the level of technology and effluent limitation
guidelines for the breakfast cereal, and wheat starch segment of
the grain mills point source category, it is recognized that
present plants, with only few exceptions, discharge untreated or
partially treated waste water tc municipal sewage systems. While
direct discharge to municipal systems are the result, effluent
guidelines as applicable to discharge to navigable waters from
industrial guidelines for the ready-to-eat and wheat starch
manufacturing subcategories is apparent where any plant
modifications or changes in existing practices would result in
discharge of process waste waters directly to navigable waters.
EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION OF THE BEST
AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE
Based on the information contained in Sections III through VIII
of this document, it has been determined that the effluent reduc-
tions attainable through the application of the best available
technology economically achievable are those presented in Table
13. The values presented in Table 13 represent the maximum
allowable waste water effluent loading for any 30 consecutive
calendar days. To allow for variances, excursions above these
levels are permitted for a maximum daily average of 3.0 times the
average 30-day values. These standards are based on unit weight
of pollutant per unit weight of raw material (wheat starch) for
the wheat starch and gluten subcategory, and per unit weight of
finished cereal product for the ready-to-eat cereal subcategory.
Table 13
Effluent Reduction Attainable Through the Application
of Best Available Technology Economically Achievable
Industry BOD Suspended Solids £H
Subcategory. k3/kkgjlbs/1000_lbs)_ k2/kkgilbs/1000_lbs]_
Animal feed
manufacturing No discharge of process wastes
Hot cereal
manufacturing No discharge of process wastes
Ready-to-eat cereal
manufacturing 0.20 0.15 6-9
Wheat starch and
gluten manufacturing 0.50 0.40 6-9
IDENTIFICATION OF BEST AVAILABLE TECHNOLOGY ECONOMICALLY
ACHIEVABLE
For the segments of the grain milling industry covered in this
document, the best available technology economically achievable
for those subcategories with waste water discharges comprises im-
proved solids separation following activated sludge or comparable
biological treatment. Improved solids separation can be repre-
sented best by deep bed filtration and/or carbon filtration
104
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although alternative systems may be available. It is anticipated
that the technology of removing biological solids by filtration
will improve rapidly with the increased use of such treatment
processes in many industries and municipalities.
Improved stability and performance of the biological treatment
processes is a significant factor in the successful application
of deep bed filtration. At present, upsets do occur in activated
sludge systems handling high strength waste waters and might be
expected to result in some efficiency and effectiveness loss of
deep bed filtration. A reasonable allowance must be made in the
established effluent guidelines limitations to accoutn for
variance in daily effluent quality with best operation.
RATIONALE FOB THE SELECTION OF THE BEST AVAILABLE TECHNOLOGY
ECONOMICALLY ACHIEVABLE
E§§dy_-to-Eat Cereal Manuf acturincj
Cost of ApjDlication-
As presented in Section VIII, the investment costs for providing
the best available technology economically achievable are
$563,300 for a small cereal plant (90,700 kg/day), $875,300 for a
medium sized plant (226,800 kg/day), and $1, till, 700 for a large
plant (544,300 kg/day). Total annual costs for the three size
ranges are $139,300, $223,100, and $359,900, respectively.
ASS-c Sizex and Ty_p_e of Production Facilities-
As discussed in Section IX, differences in age or size of produc-
tion facilities in the ready-to-eat cereal manufacturing sufccate-
gory do not significantly affect the application of the best
available technology economically achievable. Likewise, the
production methods employed by the different plants are similar
and do not affect the applicability of this technology.
Engineering Aspects of Application
As similarly discussed for best practicable control technology
currently available in Section IX, the control technologies
specified herein have not been specifically demonstrated for
process waste water from ready-to-eat cereal plants. The basic
treatment rpocesses in attaining the specified level of effluent
load limitations have received industrial and municipal
application in recent years with successful production of a high
quality effluent.
Present process waste water treatment technology demonstrated in
the industry is jduged inadequate. A transfer of available
technology is necessary where process waste waters are to be
treated with direct discharge to navigable waters. The
technology utilized in attaining the stipulated effluent
105
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limitations is readily transf errable. This technology may be
substantially aided by in-process control such as reduction of
water use and pollutant contributions from clean-up operations.
The technology is judged economically and technologically
feasible. Biodegradability of the process waste water with
nutrient addition has been demonstrated and fully established
through an existing full-scale pretreatment facility now in
operation. The technology has strong premise of producing an
effluent of 30 mg/1 of both BOD5_ and suspended solids.
P£2£§§§ Changes
No nasic process changes will be necessary to implement these
control technologies. Substitution of dry clean-up for wet
clean-up operations can substantially reduce pollutant loads from
the industry.
SQvironmental Aspects
The application of the best available technology economically
achievable will not create any new sources of air or land
pollution, or require significantly more energy than the best
practicable control technology currently available. Power needs
for this level of treatment technology were estimated to be about
115 kw (155 hp) for a medium sized plant as defined in Section
VIII. This demand is small when compared to the total production
plant power requirements.
Wheat Starch and Gluten Manufacturing
Cost of ^Application-
The investment cost of applying the best available technology
economically achievable, defined above, to a moderate-sized wheat
starch and gluten plant has been estimated in Section VIII to be
$996,000. Total annual costs are estimated at $264,000.
Age^ Sizex and Ty_p_e of Production Facilities
As discussed in Section IX, the application of this level of
control technology is not dependent upon the size or age of the
plants. Production methods employed by the different plants are
similar and do not affect the applicability of this technology.
Aspects of Application
As previously discussed in relation to ready-to-eat cereal
plants,, the specified treatment technology has not been
specifically demonstrated for wheat starch and gluten
manufacturing process waste waters. However, these processes are
readily available, transferrable from other treatment
applications and economically and technically feasible.
Technology as now practiced is judged inadequate where direct
discharge of treated process waste water to navigable waters
106
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result. The -technology may be aided by reduction of in-plant
clean-up water use (generally representing 5 to 10 percent of the
total process waste water flow) , and recycling of process water
in the production operation. Biodegradability of the waste has
been firmly established by results at one operational
pretreatment facility, and pilot plant studies. High organic
removals are necessitated by the extraordinarily high pollutant
potential of the representative waste water. The technology will
result in effluent concentrations of 10C mg/1 of BOD5 and
suspended solids.
Changes
No basic changes are necessary to implement these control
technologies. Reduction in water use, and recycling of water for
production purposes can reduce the reliance upon end-of-pipe
treatment technology.
Non-water Quality Environmental Aspects
Power requirements for the prescribed treatment system are small
compared to the overall production demands. The estimated energy
requirement for waste treatment at a typical wheat starch plant
is 185 kw (250 hp) . Other environmental considerations will not
be affected by the application of this control technology.
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SECTION XI
NEW SOURCE PERFORMANCE STANDARDS
INTRODUCTION
Standards of performance are presented in this section for new
sources. The term "new source" is defined to mean "any source,
the construction of which is commenced after the publication of
the proposed regulations prescribing a standard of performance."
These standards of performance are to reflect higher levels of
pollution control that may be available through the application
of improved production processes and/or treatment techniques.
Consideration should be given to the following factors:
a. the type of process employed and process changes;
b. operating methods and in-plant controls;
c. batch as opposed to continuous operations;
d. use of alternative raw materials;
e. use of dry rather than wet processes; and
f. recovery of pollutant as by-products.
The new source performance standards represent the best in-plant
and end-of-process control technology coupled with the use of new
and/or improved manufacturing processes. In the development of
these performance standards, consideration must be given to the
practicability of a standard permitting "no discharge" of
pollutants.
NEW SOURCE PERFORMANCE STANDARDS
The performance standards for new sources in the subcategories of
the grain milling industry covered in this document are presented
in Table 14. Standards (BOD and suspended solids) are given in
terms of unit weight of pollutant per unit weight of raw material
(wheat flour) for the wheat starch and gluten subcategory and per
unit weight of finished cereal product for the ready-to-eat
cereal subcategory.
108
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Table 14
New Source Performance standards*
BOD Suspended Solids pH
kS/JSJSgilks/lOOCLlbsl J$g/kJ$gJlbs/1000_lbsl
Animal feed
manufacturing No discharge of process wastes
Hot cereal
manufacturing No discharge of process wastes
Ready-to-eat cereal
manufacturing 0.20 0.15 6-9
Wheat starch and
gluten manufacturing 1.0 1.0 6-9
*Maximum average of daily values for any period of 30
consecutive days.
The values given in Table 13 reflect the maximum allowable waste
water effluent loading for any 30 consecutive calendar days. To
allow for variances, excursions above these levels are permitted
for a maximum daily average of 3.0 times the average 30-day
levels.
RATIONALE FOR THE SELECTION OF NEW SOURCE PERFORMANCE STANDARDS
B£§
-------
Process e -
The basic production methods employed in ready-to-eat cereal
manufacturing are not likely to be altered significantly in the
future. Although new types of equipment are constantly being
developed and incorporated into the manufacturing operations, the
basic process will probably remain largely in its present form.
Furthermore, since most waste waters from a ready-to-eat cereal
plant are generated in cleanup operations, it is not anticipated
that changes in production processes will significantly alter
waste characteristics and waste water flow volumes contributed by
this industry .
Methods and In-Plant Controls
As discussed in Section VII, in-plant controls are not
anticipated to have a major effect on waste loads from ready-to-
eat cereal plants. New plants do offer the possibility of
incorporating controls such as dry-collection systems for product
spillage, but significant usage of water in wet cleanup
operations may still be expected.
At present, most plants in this segment of the grain milling in-
dustry recover substantial amounts of product spillage in a dry
form for use in animal feed. These recoveries might be increased
at new plants by implementing improved collection methods and
systems, but no new recovery methods are presently anticiapted.
Wheat Starch and Gluten Manufacturing
The new source performance standards for the wheat starch and
gluten manufacturing sutcategory fall between The technology
required to meet the effluent limitations guidelines established
for the best practicable control technology currently available
and the best available technology economically achievable. these
standards includes biological treatment, final sedimentation, and
a further solids removal step such as a stabilization basin or
deep bed filters. Two factors properly influence the selection
of the proposed new source performance standard. One is the
extremely high organic strength and suspended, solids con-
centrations of the process waste water from wheat starch plants,
which make waste load reductions beyond conventional secondary
treatment quite difficult. A second factor is that the degree of
pollutant reduction required by end-of-process treatment has not
been specifically demonstrated at any full-scale plant, even
though reliable technology is available and transferable. Water
reuse and conservation offer alternatives to reducing waste loads
through in-plant controls, and together with end-of-pipe
treatment, may be the most effective means of pollutant
reduction. Several new plants now under construction are
incorporating such in-plant measures for substantial reductions
in water use and waste loads.
110
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The production processes at existing wheat starch plants are
basically the same throughout the industry. It is known that two
new plants, presently under construction, anticipate major
reductions in water usage and waste loads. These waste load
reductions have yet to be demonstrated, however. If improved
waste water characteristics do result at these plants, re-evalua-
tion of the proposed new source performance standards may be
warranted.
Ill
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SECTION XII
ACKNOWLEDGMENTS
This study was performed in its investigative, data gathering,
and preparatory aspects by the firm of Sverdrup & Parcel and
Associates, Inc., St. Louis, Missouri, under the direction of Dr.
H.G. Swartz. Mr. Allan Carter served as the principal Engineer.
Mr. Richard V. Watkins, P.E. of the U.S. Environmental Protection
Agency served as the principal project officer on the work. Mr.
Robert J. Carton served as the EPA project officer during the
early stages of the project.
Appreciation is wished to be extended to the many people in the
animal feed, breakfast cereal, and wheat starch industries who
cooperated in providing information for this study. Special
mention is given to company representatives who were particularly
helpful in this effort:
Mr. J. F. Lavery of Eaker/Beech-Nut Corporation;
Mr. G. R. D. Williams of CPC International Inc;
Mr. John Wingfield and Mr. Howard Hall of Centennial Mills;
Mr. Robert Cerosky, Mr. V. J. Herzing, and Mr. M. A. Tubbs of
General Foods Corporation;
Mr. J. W. Haun, Mr. Donald Thimsen, and Mr. Bob Syrup of
General Mills, Inc;
Mr. J. W. Gentzkow of General Mills Chemicals, Inc;
Mr. George T. Gould of Gould Engineering Company;
Mr. Paul Kehoe, Mr. Bill Boyd, and Mrs. Toni Carrigan of
The Kellogg Company;
Mr. C. E. Swick of Kent Feeds;
Mr. Lloyd Sutter of Loma Linda Foods;
Mr. Donavon L. Pautzke and Mr. Ken Klimisch of Malt-0-Meal Company;
Mr. Leonard Nash of Nabisco, Inc;
Mr. W. F. Hanser and Mr. W. H. Drennan of National Oats Company;
Mr. A. J. Sowden, Mr. T. R. Sowden, and Mr. Gary Lowrance of
New Era Milling Company;
Mr. Tom Mole of Quaker Oats Company;
Mr. Frank Hackmann and Mr. C. B. Smith of Ralston Purina Company;
Mr. William Hagenbach and Mr. Robert Popma of the A. E. Staley
Manufacturing Company.
Acknowledgment is also given to Dr. Eugene B. Hayden, President
of the Cereal Institute, and Mr. Oakley Ray, President of the
American Feed Manufacturers Association, who were helpful in
providing input to this study and in soliciting the cooperation
of their member companies.
Special mention and acknowedgment is made of the following EPA
grain industry working group members who assisted in the project
evaluation and review of the draft and final documents: John E.
Riley, Chairiran and Ernst Hall, Deputy Director, Effluent
Guidelines Division; G.W. Frick and R.E. McDevitt, Office of the
113
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General Counsel; Maxwell Cochran and Kenneth Dostal, NERC,
Corvallis; Edmund Struzeski, NFIC, Denver; Arthur Mallon, ORD;
William Sonnett, Permit Assistance and Gail Load, Office of
Planning and Evaluation.
Acknowledge is made to the assistance provided by the EPA
regional offices and research centers as well as those in State
and municipal offices who provided information and assistance
during the study.
The contributions of Acquanetta Delaney, Barbara Wortman and Jane
D. Mitchell in the preparation of the manuscript are gratefully
acknowledged.
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SECTION XIII
REFERENCES
1. "Battle Creek - Cereal Capital of the World", Inside Battle
* Creek, Battle Creek Public Schools Brochure No. 6, 19bb.
2. "Breakfast Cereals, Part of Modern Life", Cereal Institute
* Publication, February, 1973.
3. Brody, Julius, Fishery. By-Products Technology, AVI Publishing
Company, Inc., Westport, Connecticut, 1965.
4. Dyer, Irwin A., and O'Mary, C. C., The Feedlot, Lea 8
Febiger, Philadelphia, Pennsylvania, 1972.
5. Eynon, Lewis, and Lane, J. Henry, Starch^ Its Chemistry^
Technology^ and Uses, W. Heffer and Sons Ltd.,
Cambridge, 1928."
6. Koon, J. H., Adams, Carl E., Jr., Eckenfelder, W. Wesley,
Jr., "Analysis of National Industrial Water Pollution
Control Costs", submitted to U.S. Environmental
Protection Agency, Office of Economic Analysis,
Washington, D. C., May 21, 1973.
7. Matz, Samuel A., Cereal Technology, AVI Publishing Company,
Inc., Westport, Connecticut, 1970.
8. Matz, Samuel A., The Chemistry, and Technology of Cereals as
Food and Feed, AVI Publishing Company, Inc., Westport,
Connecticut, 1959.
9. Patterson, W. L., and Banker, R. F., Black & Veatch
Consulting Engineers, "Estimating Costs and Manpower
Requirements for Conventional Wastewater Treatment
Facilities", Report for the Office of Research and
Monitoring, Environmental Protection Agency, October,
1971.
10. Radley, J. A., Starch and Its Derivatives, Chapman & Hall
Ltd., London, 1940.
11. Reece, F. N., "Design of a Small Pushbutton Feed Mill for
Research Stations", Feedstuffs, pp. 39-40, September 24,
: 1973.
12. Riggs, J. K., "Fifty Years of Progress in Beef Cattle
Nutrition", Journal of Animal Science, Volume 17, 981-
1006, 1958.
115
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13. Sanford, F. Bruce, "Utilization of Fishery By-Products in
Washington and Oregon", Fishery Leaflet No. 370, U.S.
Department of the Interior, Fish and Wildlife Service,
March, 1950.
14. Schaible, Philip J., Poultry.! feeds and Nutrition, AVI
Publishing Company, Inc., Westport, Connecticut, 1970.
15. Seyfried, C. F., "Purification of Starch Industry Waste
Water", Proceedings of the 23rd Industrial Waste
Conference, Purdue University, Lafayette, Indiana, May
7-9, 1968.
16. Shannon, L. J., Gorman, P. G., Epp, D. M., Gerstle, R. w.,
Devitt, T. W., Amick, R., "Engineering and Cost Study of
Emissions Control in the Grain and Feed Industry",
Environmental Protection Agency, Research Triangle Park,
North Carolina.
17. Sherwood, Ross M., The Feed Mixersl Handbook, Interstate
Publishers, Danville, Illinois, 1956.
18. Whistler, Roy L. and Paschall, Eugene F., Starchy Chemistry
and Technology^ Volume I± Fundamental Aspects, Academic
Press, New York, 1965.
19. Whistler, Roy L. and Paschall, Eugene F., Starchy Chemistry
§DJ lechnglogyL Volume IIX Industrial Aspects, Academic
Press, New York, 1967.
116
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METRIC TABLE
CONVERSION TABLE
MULTIPLY (ENGLISH UNITS)
ENGLISH UNIT ABBREVIATION
acre
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
ton (short)
yard
* Actual conversion, not a multiplier
by TO OBTAIN (METRIC UNITS)
CONVERSION ABBREVIATION METRIC UNIT
hectares
cubic meters
kilogram - calories
kilogram calories/kilogram
cubic meters/minute
cubic meters/minute
cubic meters
liters
cubic centimeters
degree Centigrade
meters
liters
liters/second
killowatts
centimeters
atmospheres
kilograms
cubic meters/day
kilometer
atmospheres (absolute)
square meters
square centimeters
metric ton (1000 kilograms)
meter
ac
ac ft
BTU
BTU/lb
cfm
cfs
cu ft
cu ft
cu in
°F
ft
gal
gpm
hp
in
in Hg
Ib
mgd
mi
psig
sq ft
sq in
ton
yd
0.405
1233.5
0.252
0.555
0.028
1.7
0.028
28.32
16.39
0.555(°F-32)*
0.3048
3.785
0.0631
0.7457
2.54
0.03342
0.454
3,785
1.609
(0.06805 psig +1)*
0.0929
6.452
0.907
0.9144
ha
cu m
kg cal
kg cal/kg
cu m/min
cu m/min
cu m
1
cu cm
°C
m
1
I/sec
kw
cm
atm
kg
cu m/day
km
atm
sq m
sq cm
kkg
m
117
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