Development Document for Effluent Limitations Guidelin
and New Source Performance Standards for the
APPLE, CITRUS AND POTATO
Processing Segment of the
Canned and Preserved Fruits
and Vegetables
Point Source Category
MARCH 1974
•& U.S. ENVIRONMENTAL PROTECTION AGENCY
"£
UJ
^ Washington, D.C. 20460
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DEVELOPMENT DOCUMENT
for
EFFLUENT LIMITATIONS GUIDELINES
and
NEW SOURCE PERFORMANCE STANDARDS
for the
APPLE, CITRUS AND POTATO PROCESSING
SEGMENT OF THE CANNED AND PRESERVED
FRUITS AND VEGETABLES
POINT SOURCE CATEGORY
Russell E. Train
Administrator
Roger Strelow
Acting Assistant Administrator for Air & Water Programs
Allen Cywin
Director, Effluent Guidelines Division
James D. Gallup
Project Officer
f
i March 1974
Effluent Guidelines Division
Office of Air and Water Programs
U. S. Environmental Protection Agency
Washington, D.C. 20460
For sale by the Superintendent ol Documents, U.S. Government Printing Office
Washington, D.C. 80402 - Price $2.15
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ABSTRACT
This document presents the findings of a study of the apple, citrus and
potato processing segment of the canned and preserved fruits and
vegetables industry for the purpose of developing waste water effluent
limitation guidelines. Federal standards of performance for new sources
in order to implement Section 304 (b) and 306 of the Federal Water
Pollution Control Act Amendments of 1972 (the "Act"). The first phase
of the study is limited to processors of apple products (except caustic
peeled and dehydrated products), citrus products (except pectin and
pharmaceutical products), and frozen and dehydrated potato products.
Other commodities in S.I.e. 2033, 2034, and 2037 will be covered in a
subsequent phase of this study.
Effluent limitations guidelines are set forth for the degree of effluent
reduction attainable through the application of the "Best Practicable
Control Technology Currently Available", and the "Best Available
Technology Economically Achievable", which must be achieved by existing
point sources by July 1, 1977, and July 1, 1983 ,respectively. The
"Standards of Performance for New Sources" set forth the degree of
effluent reduction which is achievable through the application of the
best available demonstrated control technology, processes, or other
alternatives.
The proposed regulations for July 1, 1977, require in-plant waste
management and operating methods, together with the best secondary
biological treatment technology currently available for discharge into
navigable water bodies. This technology is represented by preliminary
screening, primary treatment (potatoes only) and secondary biological
treatment.
The recommended technology for July 1, 1983, and for new source
performance standards, is in-plant waste management and preliminary
screening, primary sedimentation (potatoes only), the best biological
secondary treatment and disinfection (chlorination). In addition, more
intensive biological treatment, and in a few cases final multi-media or
sand filtration, may be required.
Land treatment systems such as spray or flood irrigation are effective
and economic alternatives to the biological systems described above.
When suitable land is available, land treatment is the preferred
technology for July 1, 1977, for July 1, 1983, and for new source
performance standards.
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CONTENTS
Section
I CONCLUSIONS 1
II RECOMMENDATIONS 3
III INTRODUCTION 5
Purpose and Authority 5
Data sources 6
General Description of the Industry 7
Apples 7
Citrus 12
Potatoes 17
Profile of Manufacturing Processes 20
Apples 20
Citrus 23
Potatoes 27
IV INDUSTRY CATEGORIZATION 33
Categorization 33
Rationale for Categorization 34
Raw Materials 34
Products and By-Products 42
Production Processes 43
Age of Plant 44
Size of Plant 45
Plant Location 46
Waste Treatability 55
V WATER USAGE AND WASTE CHARACTERIZATION 57
Waste Water Characterization 57
Apples 58
Water Use and Waste Characterization 58
Factors Affecting Wastewater 60
ill
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CONTENTS (Continued)
Section.
IX EFFLUENT REDUCTION ATTAINABLE THROUGH
APPLICATION OF BEST PRACTICABLE CONTROL
TECHNOLOGY CURRENTLY AVAILABLE 157
Introduction 157
Effluent Reduction Attainable Through
the Application of Best Practicable
Control Technology Currently Available 158
Identification of Best Practicable
Control Technology Currently Available 158
Rationale for the Selection of Best
Practicable control Technology Currently
Available 161
Age and Size of Equipment and Facilities 161
Total Cost of Application in Relation to
Effluent Reduction Benefits 162
Engineering Aspects of Control Technique
Applications 162
Process Changes 162
Non-Water Quality Environmental Impact 165
Factors to be Considered in Applying
BPCTCA Limitations 165
X EFFLUENT REDUCTION ATTAINABLE THROUGH THE
APPLICATION OF THE BEST AVAILABLE TECHNOLOGY
ECONOMICALLY ACHIEVABLE 169
Introduction 169
Effluent Reduction Attainable Through
Application of the Best Available Technology
Economically Achievable 170
Identification of the Best Available
Technology Economically Achievable n\
Rationale for Selection of the Best Avail-
able Technology Economically Achievable 173
vi
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CONTENTS (Continued)
E13S
X Age and Size of Equipment and Facilities 173
Total Cost of Application in Relation to
Effluent Reduction Benefits 174
Engineering Aspects of Control Technique
Application 174
Process Changes 175
Non-Water Quality Environmental Impact 175
Factors to be Considered in Applying
BACTCA Limitations 175
XI NEW SOURCE PERFORMANCE STANDARDS 179
Introduction 179
Effluent Reduction Attainable for
New Sources 180
Pretreatment Requirements 180
XII ACKNOWLEDGEMENTS 181
XIII REFERENCES 183
XIV GLOSSARY 187
XV APPENDICES 199
CONVERSION TABLE
vii
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TABLES
Number
1 Apples - Production by States in
United States 1971 8
2 Apples - Fresh Pack and Manufactured
Products in United States 1969-71 10
3 Citrus - United States Production &
Processing by State 1970-72 13
U Potatoes - Production by States in
United States 1969-71 18
5 Distribution of Waste Load by
Subcategory 36
6 Effect of Location for Various
Apple Plants 37
7 Effect of Paw Material Mix at Various
Citrus Plants 38
8 Effect of Paw Material Mix at Citrus
Plant 123 39
9 Effect of Location for Various
Citrus Plants 40
10 Effect of Location for Various
Potato Plants 41
11 Average (Range) of BOD and Flow for
Various Apple Product Styles 47
12 Average (Range) of BOD and Flow for
Various Citrus Product Styles 48
13 Average (Range) of BOD and Flow for
Various Potato Product Styles 49
14 Effect of Waste Heat Evaporator for
Various Citrus Plants 50
viii
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Number
15 Average (Range) of BOD and Flow for 51
Various Potato Peelers
16 Average (Range) of BOD and Flow for
Various Apple Plant Sizes 52
17 Average (Range) of BOD and Flow for
Various Citrus Plant Sizes 53
18 Average (Range) of BOD and Flow for
Various Potato Plant Sizes 54
19 List of Apple Industry Waste Load 59
20 List of Citrus Industry Waste Load 63
21 List of Potato Industry Waste Load 69
22 Water Usage and Waste Characterization
in Apple Processing 70
23 Water Usage and Waste Characterization
in Citrus Processing 74
24 Water Usage and Waste Characterization
in Potato Processing 76
25 Effectiveness of Various Secondary
Treatment Systems 110
26 Effectiveness and Application of Waste
Treatment Systems 132
27 Effluent Treatment Sequence by Subcategory
to Achieve Various Levels of Effluent
Reduction 139
28 . Investment and Annual Costs: Preliminary,
Primary, and Biological Waste Treatment
Systems 140
29 Investment and Annual Costs: Advanced
Waste Treatment Systems and Ultimate
Disposal 141
30 Investment and Annual Cost by Effluent
Reduction Level for Apple Juice 142
IX
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Number
31 Investment and Annual Cost by Effluent 143
Reduction Level for Apple Products
32 Investment and Annual Cost by Effluent
Reduction Level for Citrus Products 144
33 Investment and Annual Cost by Effluent
Reduction Level for Frozen Potato Products 145
34 Investment and Annual Cost by Effluent
Reduction Level for Dehydrated Potato
Products 146
35 Total Investment and Annual Cost for Each
Effluent Reduction Level by Subcategory
and Size 147
36 Total Subcategory and Industry Investment
Cost for Each Level of Effluent Reduction 143
37 Total Subcategory and Industry Annual Cost
for Each Level of Effluent Reduction 149
38 Total Capital Investment to Meet Each
Level of Effluent Reduction 150
39 Total Annual Cost to Meet Each Level of
Effluent Reduction 151
40 Recommended Effluent Limitation Guidelines
for 1 July 1977 (Maximum Thirty Day Average) 150
41 Effluents from Biological Secondary
Treatment Systems 164
42 Recommended Effluent Limitation Guidelines
for 1 July 1977 (Maximum Daily Average) 157
43 Recommended Effluent Limitation Guidelines
for 1 July 1983 (Maximum Thirty Day Average) 171
44 Recommended Effluent Limitation Guidelines
for 1 July 1983 (Maximum Daily Average) 177
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FIGURES
Number Title Page
1 Number of Operating Apple Processing
Plants in United States 9
2 Citrus Processing Plants 15
3 Potatoes - Number of Operating
Canned & Frozen Plants in United States 19
U Water Flow Diagram - Apple Slices (Frozen) 71
5 Water Flow Diagram - Apple Sauce (Canned) 72
6 Water Flow Diagram - Apple Juice 73
7 Water Flow Diagrams - Juice, Oil, Segments,
and Peel Products (Citrus) 75
8 Water Flow Diagram - Dehydrated Potato Flakes 77
9 Water Flow Diagram - Frozen Potato Products 78
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SECTION I
CONCLUSIONS
The purpose of this report is to establish waste water effluent
limitation guidelines for a segment of the canned and preserved fruit
and vegetable industry. This segment consists of processors of the
following products: apple products (except caustic peeled and dehydrated
products); all citrus products (except pectin and pharmaceutical
products); and all frozen and dehydrated potato products. A conclusion
of this study is that this segment of the industry comprises five
subcategories:
1. Apple Processing
2. Apple Processing
3. Citrus Processing
4. Potato Processing
5. Potato Processing
Apple Juice
Apple Products Except Juice
All Products
Frozen Products
Dehydrated Products
The major criteria for the establishment of the subcategories are the
five day biochemical oxygen demand (BOD!5) and the suspended solids (SS)
in the plant waste water. Subcategorization is required on the basis of
raw materials processed and products produced. Evaluation of factors
such as age, size and location of plant, production processes, and
similarities in available treatment and control measures substantiate
this industry Subcategorization.
The wastes from all subcategories are amendable to biological treatment
processes and several apple, citrus, and potato processing plants are
able to achieve high levels of effluent reduction (BOD and suspended
solids) through secondary biological treatment systems. The following
plants are currently achieving at least the effluent reduction required
through the application of Best Practicable Control Technology Currently
Available: four apple plants including one juice plant; five citrus
plants; and four frozen potato plants including one dehydrated plant
(see Table 41) . It is estimated that the costs of achieving these
limits by all plants within this segment of the industry will be between
$17 and $26 million ($11.6 million for land and land treatment
facilities included). Costs of $17 million would increase the capital
investment in the industry segment by about 1.4 percent and would
increase the retail price of the products produced by approximately 2.3
percent.
with present secondary biological treatment systems without advanced
treatment methods such as sand filtration, at least one apple, citrus
and potato plant in each of the five subcategories is presently
achieving the high levels of effluent reduction required by the
application of the Best Available Control Technology Economically
Achievable (see Table 41). It is estimated that the costs above those
for 1977 for achieving the 1983 limits for all plants within this
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segment of the industry will be an additional $12 million. These costs
would increase the capital investment by about 1.0 percent and the
retail price of the products produced by approximately 1.6 percent.
It is concluded that land treatment is an effective and economical
alternative where suitable and adequate land is available. Over forty
apple, citrus, and potato processors utilize this technology to achieve
minimal waste water discharge.
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SECTION II
RECOMMENDATIONS
The waste water effluent reduction limitations attainable through the
application of the Best Practicable Control Technology Currently
Available are based on the performances of exemplary secondary
biological systems treating apple, citrus or potato waste water. Best
Practicable Control Technology Currently Available includes the
following treatment components: for the apple juice and apple products
(except juice) subcategories (except caustic peeled and dehydrated
products) — preliminary screening and secondary biological treatment;
for the citrus products subcategory (except pectin and pharmaceutical
products) — cooling towers for weak cooling wastes and preliminary
screening and secondary biological treatment for process waste waters;
for the frozen and dehydrated potato products subcategories
preliminary screening, primary sedimentation, and secondary biological
treatment. Where sufficient quantities of suitable land are available,
land treatment such as spray irrigation is an attractive alternative to
biological treatment in order to achieve BPCTCA limitations.
Recommended BPCTCA guidelines are set forth in the following tabulation
including maximum limitations for any one day and maximum limitations
for the average of daily values for any period of thirty consecutive
days;
Effluent Maximum Maximum
§!2j2cate3orY. (1) Characteristic Daily Average Thirty Day Ave.
kg/kkq Ib/T JS3£JSJ!S2 ife^IE
Apple Juice BOD5 0.60&.34 1.20 0.30 *•'*» 0.60
Suspended Solids 0.80 .M 1.60 0.40 'zz 0.80
Apple Products BOD5 1. 10 ,»* 2.20 0.55»-37 1.10
(Except Juice) Suspended Solids 1.40 '-' 2.80 0.70 •*** 1.40
Citrus Products BOD5 0.80-S* 1.60 0.40--?^ 0.80
Suspended Solids 1.70 A'2 3.40 0.85 •** 1.70
Potato Products BOD5 2.80£-?/ 5.60 1.40 '''3 2.80
(Frozen) Suspended Solids 2.80^"?^ 5.60 1.40/'#' 2.80
Potato Products BODS 2.40''** 4.80 1.20 £62 2.40
(Dehydrated) Suspended Solids 2.80 2.«7 5.60 1.400.'* 2.80
(1) For all subcategories pH should be between 6.0 and 9.0.
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The waste water effluent reduction limitations attainable through the
application of the Best Available Control Technology Economically
Achievable are based on the performance of the best secondary biological
system treating apple, citrus or potato waste water. For each
subcategory Best Available Control Technology Economically Achievable
includes Best Practicable Control Technology Currently Available plus
additional secondary biological treatment and disinfection
(chlorination). Advanced treatment such as sand filtration could also
be used. Recommended waste water guidelines are set forth in the
following tabulation:
§ubcategory(1)
Apple Juice
Apple Products
(Except Juice)
Citrus Products
Potato Products
(Frozen)
Potato Products
(Dehydrated)
Effluent
Characteristic
BOD5
Suspended Solids
BOD5
Suspended Solids
BOD5
Suspended Solids
BOD 5
Suspended Solids
BOD5
Suspended Solids
Maximum
paily^Average
Ib/T
0.40
0.40
0.40
0.40
0.28
0.40
0.68
2.20
0.68
2.20
0.20
0.20
0.20
0.20
0.14
0.20
0.34
1. 10
0.34
1. 10
Maximum
Thirty Day Aye.
" Ib/T~
0.10
0.10
0.10
0.10
0.07
0.10
0. 17
0.55
0. 17
0.55
0.20
0.20
0.20
0.20
0. 14
0.20
0.34
1.10
0.34
1.10
(1) For all subcategories pH should be between 6.0 and 9.0.
(2) For all subcategories most probable number (MPN) of fecal coliforms
should not exceed 400 counts per 100 ml.
The waste water effluent reduction limitations for new sources are the
same as those attainable through the application of the Best Available
Control Technology Economically Achievable. These limitations are
possible because of the present availability of the treatment technology
to attain this level of effluent reduction and because new source site
selection can assure land availability for land treatment facilities
(such as spray irrigation).
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SECTION III
INTRODUCTION
PURPOSE AND AUTHORITY
On October 18, 1972, the Congress of the United States enacted the
Federal Water Pollution Control Act Amendments of 1972. The Act in part
required that the Environmental Protection Agency (EPA) establish
regulations providing guidelines for effluent limitations to be achieved
by "point sources" of waste water discharge into navigable waters and
tributaries of the United States.
Specifically, Section 301 (b) of the Act requires the achievement by not
later than July 1, 1977, of effluent limitations for point sources,
other than publicly owned treatment works, which require the application
of the Best Practicable Technology Currently Available as defined by the
Administrator pursuant to Section 304 (b) of the Act. Section 301 (b)
also requires the achievement by not later than July 1, 1983, of
effluent limitations for point sources, other than publicly owned
treatment works, which require the application of the Best Available
Technology Economically Achievable which will result in reasonable
further progress toward the national goal of eliminating the discharge
of all pollutants, as determined in accordance with regulations issued
by the Administrator pursuant to Section 304 (b) of the Act. Section 306
of the Act requires the achievement by new sources of a federal standard
of performance providing for the control of the discharge of pollutants
which reflects the greatest degree of effluent reduction which the
Administrator determines to be achievable through application of the
best available demonstrated control technology, processes, operating
methods, or other alternatives, including, where practicable, a standard
permitting no discharge of pollutants.
Section 304(b) of the Act requires the Administrator to publish, within
1 year of enactment of the Act, regulations providing guidelines for
effluent limitations setting forth the degree of effluent reduction
attainable through the application of the Best Practicable Control
Technology Currently Available and the degree of effluent reduction
attainable through the application of the best control measures and
practices achievable, including treatment techniques, process and
procedure innovations, operation methods and other alternatives. The
regulations proposed herein set forth effluent limitations based upon
raw material used, products produced, manufacturing process employed,
and other factors. The raw waste water characteristics for each
subcategory were then identified. This included an analysis of (1) the
source and volume of water used in the process employed and the sources
of waste and waste waters in the plant; and (2) the constituents
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(including thermal) of all waste waters including toxic constituents and
other constituents which result in taste, odor and color in water. The
constituents of waste waters which should be subject to effluent
limitations guidelines and standards of performance were identified.
The full range of control and treatment technologies existing within
each subcategory was identified. This included an identification of
each distinct control and treatment technology, including both in plant
and end-of-process technologies, which are existent or capable of being
designed for each subcategory. It also included an identification, in
terms of the amount of constituents (including thermal) and the
chemical, physical, and biological characteristics of pollutants, of the
effluent level resulting from the application of each of the treatment
and control technologies. The problems, limitations and reliability of
each treatment and control technology, and the required implementation
time was also identified. In addition, the non-water quality environ-
mental impact, such as the effects of the application of such
technologies upon other pollution problems, was also identified. The
energy requirements of each of the control and treatment technologies
were identified as well as the cost of the application of such
technologies.
The information, as outlined above, was then evaluated in order to
determine what levels of technology constituted the "Best Practicable
Control Technology Currently Available" and the "Best Available
demonstrated control technology, processes, operating methods, or other
alternatives". In identifying such technologies, various factors were
considered. These included the total cost of application of technology
in relation to the effluent reduction benefits to be achieved from such
application, the age of equipment and facilities involved, the process
employed, the engineering aspects of the application of various types of
control techniques, process changes, non-water quality environmental
impact (including energy requirements) and other factors.
DATA SOURCES
The segment of the Canned and Preserved Fruits and Vegetables Industry
category selected for this phase I effort includes S.I.C. codes 2033,
2034, and 2037 for apple processors (except caustic peeled and
dehydrated products), citrus processors (except pectin and
pharmaceutical products), and potato processors (frozen and dehydrated
products). The remaining fruit and vegetable processors in those S.I.C.
codes will be covered in a later phase of this study. The data and
recommended effluent guidelines contained in this document were
developed from information derived from a number of sources. These
sources included review and evaluation of available literature, the
results of EPA research, development and demonstration projects,
consultation with qualified experts in the field, correspondence with
industry associations, EPA Permit data, data from states and
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municipalities, and correspondence with individual processors and on-
site visits and interviews. Visits were made to, and historic data
reviewed at, more than 130 processing plants; sampling and analysis were
carried out at 38 of these plants. The principal source of raw waste
and treated effluent data was current and historical information
gathered from individual plants. Visits were made to, and historical
data reviewed from more than 40 apple processing plants, more than 50
citrus processing plants and more than 40 potato processing plants.
Appendix C contains the format for this collected data. Sampling data
was gathered from 13 apple plants, 13 citrus plants, and 12 potato
plants. The purpose of this data was to supplement or confirm data
supplied by the processor or other sources. The success of this effort
is reflected in Section V with the computation of industry raw waste
loads. Sixty-two different plants actually contributed to the
computation. All references used in developing the guidelines for
effluent limitations and standards of performance for new sources
reported herein are included in Supplement B to this document. A
listing of apple plants (AP-101 to AP-142) , citrus plants (CI-101 to CI-
149) , and potato plants (PO-101 to PO-136) used in this study is
presented in Appendix A.
GENERAL DESCRIPTION OF INDUSTRY
The apple was introduced into the western part of the country in the
middle of the nineteenth century. Apples cannot be grown satisfactorily
in the southern part of the United States because of climatic
conditions. Because the fruit requires a relatively constant, cool
temperature, production has been concentrated in relatively few states.
For the last three years, the average national apple production has been
almost three million kilo-kilograms. About 70 percent of the total
production are obtained from six leading states (Table 1) .
In 1971, there were 164 apple processing plants located in 28 states
(Figure 1). In that year total production was 2.8 million kilo-
kilograms. Of this total, about 57 percent went for fresh pack and 43
percent for processing. Of the total crop, apple sauce and other
canning took 18 percent; frozen products 3 percent, and dried products
less than 2 percent. Other products, which consist mostly of apple
juice and vinegar, accounted for over 20 percent of the total crop
(Table 2). By geographic distribution, about 50 percent of the
processed apple products is obtained from the states of Michigan, New
York and Pennsylvania, while the states of Washington, Virginia and
California each contributed about 11 percent. The remaining 17 percent
of processed apple products is obtained from 22 states, where most of
the processing is concentrated in the production of vinegar.
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TABLE 1
APPLES - PRODUCTION BY STATES IN U.S. 1971
No. Of
Fresh Pack
Processed
Location
Michigan
New York
California
Washington
Pennsylvania
Virginia
Other States
Processing
Plants
35
28
21
15
9
7
49
M kg
136.2
160.3
50.8
415.9
84.0
89.0
650.7
M Ibs.
300.0
353.0
112.0
916.0
185.0
196.0
1,433.3
M kg
190.7
259.7
130.8
128.9
145.3
128.9
202.8
M Ibs.
420.0
572.0
288.0
284.0
320.0
284.0
446.8
TOTAL
164
1,586.9
3,495.3
1,187.1 2,614.8
Source: Agricultural Statistics - 1972
U.S. Department of Agriculture
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FIGURE 1
NUMBER OF OPERATING APPLE PROCESSING PLANTS IN UNITED STATES
T " * ^"^ • • ^» • • «H • • M«M • • J\
• NORTH DAKOTA ; '•*",
I {MINNESOTA
| \
' i
.^NEBRASKA"" "^—>.A
L....-.-J
^ —
------
CLEARTYPE
IMM MMW HfC US P»I Off
STATE OUTLINE
UNITED STATES
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TABLE 2
APPLES - FRESH PACK AND MANUFACTURED PRODUCTS IN U.S. 1969-71
1969 1970 1971
ITEM
Fresh
Canned
Dried
Frozen
Other
TOTAL
M kg
1,682.
634.
127.
94.
509.
3,065.
9
8
2
3
5
3
M Ibs
3,707.
1,398.
280.
207.
1,122.
6,751.
•
0
3
2
6
2
8
M kg
1,597.
539.
84.
82.
552.
2,857.
9
9
9
1
7
4
M Ibs
3,519.
1,189.
187.
180.
1,217.
6,293.
•
5
3
0
8
3
9
M kg
1,586.
496.
44.
77.
569.
2,774.
9
4
2
3
1
0
M
3,
1,
1,
6,
Ibs.
495.3
093.5
97.4
170.3
253.6
110.1
Source: Agriculture Statistics - 1972, U. S. Department of Agriculture
10
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Consumption of canned apples and apple sauce has remained almost
constant over the last ten years. Frozen and dried products have also
failed to exhibit any real growth. Only apple juice products show signs
of increased consumer acceptance, with larger volumes of domestic apples
channeled to this outlet and increased juice imports apparently finding
a ready market. Trade reports indicate that apples are being used
increasingly in the production of wines.
Product Classification
The U. S. Bureau of Census classifies the apple processing industry
within Standard Industrial Classification (SIC) 203, Canned and
Preserved Fruits and Vegetables. A detailed list of product codes
applicable to the apple processing industry is contained in Appendix B.
Growth Projections
The processing of apples will continue to be concentrated in the six
leading states of Michigan, New York, Pennsylvania, Washington, Virginia
and California. Statistics covering the last few years indicate that
the production of apples in the eastern United States increased
slightly; central U. S. production remained almost constant and that of
the western states (predominately fresh pack) was down slightly.
Increased demand for apple juice is expected to exert an upward pressure
on apple production. The new factor in the apple industry is the
rapidly increasing use of apples for the production of wine. If this
trend continues, a substantial tonnage of apples will be required to
satisfy this market sector.
The technology of harvesting apples and processing them has been
relatively static for a number of years. Some of the factors that are
bringing about changes in the industry are:
1. Mechanical harvesting is increasing in order to reduce labor costs.
2. Concern over waste generation and treatment has resulted in interest
in such waste reduction techniques as dry caustic peeling and hot gas
blanching.
3. Because of improvements in controlled atmosphere storage, the season
for processing apples will become progressively longer.
It is estimated that about 1.5 million kilo-kilograms of apples will be
processed by 1977.
11
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Citrus
Citrus is the largest fruit crop in the United States, with a farm value
exceeding $400 million annually in recent years. Primarily because of
climate, citrus production is concentrated in Florida, California,
Arizona and Texas (Table 3). During the 1950's and early 1960's
production was low. Beginning in 1963, production increased steadily
because of improvements in technology, management and cultural
practices. Since 1950, Florida citrus output has more than doubled and
now represents about three-fourths of total U. S. production.
California citrus production has fallen to 18 percent of total output in
recent years as land has been converted to housing and other uses.
Arizona and Texas, together, produced approximately 5 percent of
domestic citrus output.
There are 97 citrus processing plants in 14 states (Figure 2). Florida
has 53 plants, representing more than 54 percent of the total (Table 3).
During the last two decades, there has been a striking shift in the use
of citrus from fresh to processed forms. This mainly reflects the sharp
increase in the use of Florida production for processing. In the 1971
season, Florida packed 97 percent of the citrus products produced in the
United States. Marketing patterns favor fresh citrus in Arizona,
California and Texas. But even in these states the proportion of citrus
used fresh has declined.
Processed forms include frozen, chilled and canned. Commercial
introduction of frozen concentrated citrus juices in the mid - 1940's
stimulated a rapid and dramatic increase in processing of Florida
citrus. Since that time, the rate of increase in citrus used for frozen
concentrated citrus juices has been dramatic. The proportion of the
Florida citrus crop dedicated to juice production has increased from 6
to 70 percent. The increased volume of citrus used for chilled citrus
products has also had an impact on processing use. The proportion of
the Florida citrus used for chilled citrus products has increased from 3
percent in 1945 to 14 percent in the 1971 season. In contrast to the
sharp increase in utilization of citrus for frozen concentrated and
chilled products, the volume of Florida citrus used for canning has
decreased sharply.
12
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TABLE 3
CITRUS - U.S. PRODUCTION & PROCESSING BY STATE - 1970-72
No. of
Processing
LOCATION Plants
FLORIDA 53
Oranges -Production
-Processed
Grapefruit-Production
-Processed
Tangerines-Production
-Processed
Temples -Production
-Processed
Limes -Production
-Processed
Tangelos -Production
-Processed
CALIFORNIA 20
Oranges -Production
-Processed
Grapefruit-Production
-Processed
Lemons -Production
-Processed
Tangerines-Production
-Processed
1970
1,000
kkg
5,621
5,079
1,442
891
130
26
212
97
26
13
102
45
1,327
425
155
73
438
161
25
12
1,000
Tons
6,197
5,600
1,590
983
143
29
234
107
29
14
113
50
1,463
469
171
81
483
178
28
13
1971
1,000
kkg
5,808
5,238
1,563
1,077
160
44
204
113
111
44
211
64
1,275
400
149
65
458
167
48
15
1,000
Tons
6,404
5,775
1,823
1,187
176
49
225
125
122
49
233
71
1,406
441
164
72
505
184
53
16
19
1,000
kkg
5,592
5,134
1,812
1,155
138
42
217
143
160
82
178
56
1,473
517
151
73
469
196
21
8
72
1,000
Tons
6,165
5,660
1,998
1,273
152
46
239
158
176
90
196
62
1,624
570
166
81
517
216
23
9
ARIZONA 2
Oranges -Production
-Processed
Grapefruit-Production
-Processed
Lemons -Production
-Processed
Tangerines-Production
-Processed
158 174
75 83
92 101
41 45
97 107
51 56
12 13
4 4
(Continued)
122
76
73
53
108
64
14
5
134
84
81
58
119
71
15
6
167
98
73
36
106
61
19
6
184
108
81
40
117
67
21
7
-------
TABLE 3
CITRUS- U.S. PRODUCTION & PROCESSING BY STATE
(Continued)
- 1970-72
LOCATION
No. of
Processing
Plants
1970
1971
1972
TEXAS 6
Oranges —Production
-Processed
Grapefruit-Production
1,000
kkg
171
73
294
1,000
Tons
189
81
324
1,000
kkg
253
125
366
1,000
Tons
279
138
404
1,000
kkg
237
131
334
1,000
Tons
261
144
368
TOTAL U.S.
97
Source: 1. Citrus Fruits by States,
Statistical Reporting Service,
U.S. Department of Agriculture,
October 1972, Fr Nt 3-1 (10-72)
2. The Directory of Canning, Freezing,
Preserving Industry, 1972-1973,
by Edward E. Judge & Son, Inc.
-------
FIGURE 2
CITRUS PROCESSING PLANTS
• NORTH DAKOTA ; '»•*•.
I (MINNESOTA
! \
\ \
SOUTH DAKOTA"
.
\ .j***SZ /• !
\l /NewMEw5) T^'Z'"
\ / TEXAS!
CLEARTYPE
TMMM MAH* ma u & MI or*
STATE OUTLINE
-------
Annual per capita consumption of citrus, fresh and processed combined on
a fresh weight equivalent basis, shows an erratic trend during the last
two decades. In general, fresh consumption has decreased, but processed
citrus consumption has increased, led by a sharp increase in frozen
items. Per capita consumption of frozen concentrated citrus juices
increased from 6.8 to 16.3 kg (15 to 36 Ibs) over the past two decades.
Chilled citrus juice consumption increased from 0.8 to 3.8 kg (1.7 to
8.5 Ibs) over the same period. Because of the rapid rise in frozen and
chilled juice consumption, canned citrus juice consumption decreased
substantially from 5.2 to 3.2 kg (11.5 to 7 Ibs). Consumption of canned
orange sections and citrus salad combined has also been erratic and has
accounted for less than 2 percent of processed per capita consumption.
However, consumer demand for processed citrus appears to be increasing.
Product Classification
The citrus processing industry is classified under SIC Group No. 203,
Canned and Preserved Fruits and Vegetables. A detailed list of product
codes covering the products of the citrus processing industry is
contained in Appendix B.
Growth Projection
Citrus for fresh use will continue to be grown in three western states.
However, because of the increasing demand for frozen concentrated juice,
it is expected that more citrus grown in California and Texas will be
processed. Florida will continue to be the leading state for processed
citrus products and production can be expected to expand substantially
with time to meet the rising demand.
Chilled citrus juices cannot be made from stored fruit but must be
processed immediately after harvesting. For this reason, the processing
season is short and there is little incentive to increase plant size.
In the production of frozen concentrated juice, however, the processing
season is extended through the use of stored concentrate and there is a
trend toward processing plants of larger capacity. Processing
techniques have been relatively static in recent years although the
pressure for water pollution control has resulted in some changes.
Waste heat evaporators are being introduced to treat odor-causing
wastes.
It is estimated that the quantity of citrus processed will increase to 9
million kilo-kilograms by 1977.
16
-------
Potatoes_
The potato was first introduced into the Northern American continent
from England in 1621. During the 18th and 19th centuries the potato
became a significant source of food in Europe, but because of its short
storage life it was not completely utilized. During the latter half of
the 18th century there was experimentation with various types of dried
potatoes. However, little was accomplished in this direction until
World War I when a number of dehydrated potato products were
manufactured for military use. Since that time, potatoes have ranked
high among crops utilized chiefly for food.
The average annual United States potato production over the last three
years was approximately 14 million kkg (315 million hundred weights).
Two-thirds of this total was obtained from seven leading states (Table
4). About 40 percent of total national potato production is used for
processing. In 1972, there were 112 canned and frozen potato processing
plants in 31 states (Figure 3) .
Demand for potatoes and potato products has changed markedly over the
past decade. Annual per capita consumption increased from 47.2 kg
(108.4 Ibs) in 1961 to 54.12 kg (119.2 Ibs) in 1971. The increase in
consumption is credited entirely to processed use. In contrast, per
capita consumption of fresh potatoes has fallen substantially. Frozen
french fries have paced the growth of processed potato products. Frozen
products now account for about 45 percent of all potatoes used for
processing.
Dehydrated potatoes account for about 20 percent of all potatoes used
for processing. Per capita consumption of canned potatoes has remained
almost constant at about 5 percent and the production of potato chips
account for 30 percent of potatoes.
Product Classification
The potato processing industry is classified under SIC Groups 203,
Canned and Preserved Fruits and Vegetables, 204, Grain Mill Products,
and 209, Miscellaneous Food Preparations and Kindred Products. A
detailed list of product codes within the foregoing groups is presented
in Appendix B.
Growth Projections
Potato production in the 1960's trended generally upward due to larger
output of North Dakota, Idaho and Washington. Demand for potatoes will
increase in the years ahead due to population growth and continued
increases in demand for processed convenience products. Projections
indicate that processed potato products will account for approximately
75 percent of total
17
-------
TABLE 4
POTATOES - PRODUCTION BY STATES IN U.S. 1969-71
No. of
1969
1970
1971
oo
Location
Idaho
Maine
Washington
California
North Dakota
Minnesota
New York
Wisconsin
Colorado
Michigan
Pennsylvania
Other States
TOTAL
Source :
Processing
Plants
13 3
4 1
14 1
6 1
1
3
6
9
1
5
3
47 2
112 14
Agricultural
1,000
kkg
,172.1
,593.5
,352.7
,320.8
733.6
702.6
770.6
563.4
528.6
399.3
354.6
,668.5
,160.4
Statis
M
6,
3,
2,
2,
1,
1,
1,
1,
1,
5,
31.
tics,
Ibs.
987.0
510.0
979.6
909.3
615.9
547.5
697.4
241.0
164.3
879.6
781.0
877.7
190.3
1972
1,000
kkg
3,389
1,620
1,525
1,351
790
607
770
591
598
446
375
2,714
14,781
.6
.8
.0
.1
.0
.9
.8
.5
.4
.5
.9
.4
.7
M Ibs.
7,466.0
3,570.0
3,359.0
2,976.0
1,740.0
1,339.0
1,697.7
1,302.8
1,318.0
983.4
828.0
5,978.9
32,558.8
1,000
kkg
3,443.
1,713.
1,367.
1,198.
837.
759.
689.
598.
469.
374.
370.
2,531.
14,350.
6
9
0
6
4
3
2
5
0
1
7
2
2
M
7
3
3
2
1
1
1
1
1
5
31
Ibs.
,585.0
,775.0
,011.0
,640.0
,844.5
,672.5
,518.0
,318.3
,033.0
824.1
816.5
,575.4
,608.3
U.S. Department of Agriculture
-------
FIGURE
POTATOES - NO. OF OPERATING CANNED & FROZEN PLANTS IN UNITED STATES
•- r ,—A
• NORTH DAKOTA ; •»•*•.
I I MINNESOTA
! i \
I \
•SOUTH~DAKn~ 7
;•— ^/
J*..~S vvpGVJJ*^.
\ .j **!%>&' /.. j
\ 1 MISSISSIPPI, rvt6pT6^ ^
CLoEARTYPE
STATE OUTLINE
UNITED STATES
-------
food use of potatoes by 1980. Frozen potato products are expected to
remain the leading item among the processed forms. Consumption of
dehydrated potatoes will increase only slightly, while fresh potato
consumption is projected to continue its long downward trend to a per
capita consumption in the range of 15.9 kg to 18.2 kg (35 to UO Ibs).
The size of processing plants has increased in recent years, and this
trend is expected to continue under the pressures of competition and
increased complexity of manufacturing and marketing operations. Except
for the introduction of dry caustic peeling, potato processing
techniques have not changed substantially in recent years. Increased
water pollution control activity is expected to have an impact on
processing plants in the form of better in-plant control of waste
generation and water consumption.
PROFILE OF MANUFACTURING PROCESSES
Apples
General
There are three basic products which are made from apples in large
volume: a) slices, b) sauce, and c) juice (cider). Other products such
as dehydrated apple pieces, spiced apple rings, spiced whole apples and
baked apples, are all produced in much lesser volume and are usually
produced in conjunction with one of the major products (slices, sauce,
juice) .
The apple harvest begins in some locations in midsummer and in other
areas extends through the fall season. In recent years, the processing
season which begins with the harvest of apples has been extended well
beyond the harvest period by placing an increased amount of apples in
controlled atmosphere storage. Consequently, when there is an adequate
or abundant supply of apples, most large processors can, and usually do,
operate their plants over a seven to eight month period.
During the early fall, at the peak of the harvest season, many of the
apple processors will operate their plants on a two or three shift,
five-day-per-week basis. However, when the apples are no longer being
delivered directly from the field, the processor usually operates his
plant on one shift for processing, followed by a cleanup shift.
Later in the operating year, depending upon the availability of apples,
the processor may operate his plants on an even more sporadic schedule.
20
-------
Processing Steps
Apple processing usually includes storage, washing and sorting, peeling
and coring, slicing, chopping, juice extracting, dehydrating, deaerating
and cooking. End products in approximate order of pack size are apple
sauce, apple juice, and frozen and canned apple slices.
CA (ControiledmAtmosphere) Storage - The proper ripeness of the apple
directly reflects on the final product quality. An overripe apple will
cause a poor flavor in the product, while an unripe apple will produce
an off-color and a poor flavor in the product. In the controlled
atmosphere storage, the temperature and relative humidity of the
recirculated air is closely controlled. To meet the demands of the
fresh market, the apples are periodically removed from storage, graded
or sorted, and the proper quality fruit is directed to the processor.
Washing and Sorting - Apples that are received from either the field or
CA storage must be thoroughly washed to remove all residues that may be
on the fruit. To ensure removal, in some instances, chemicals or deter-
gents are added to the wash water. The water, or a large portion of it,
is often reused within the washing system to conserve wash water and
reduce the volume of waste effluent leaving the processing plant. This
can be accomplished by (1) periodically draining the washing system, or
(2) regulating the overflow and makeup water addition to the system.
The purpose of sorting is to remove the smaller, misshapened or inferior
fruit and redirect this fruit into products, such as juice, which can
accept the lower-quality raw material.
Peeling and Coring - Mechanical peeling is the most popular method for
removing the apple peel. This is particularly true where a sliced
product is being produced. The mechanical peeler can be adjusted to
remove a greater or lesser percentage of the imperfections in the fruit.
The peel and core particles are often collected and used in the
production of either juice or vinegar stock. In a mechanical peeling
operation, the peel and core fraction represents approximately 35
percent of the apple processed.
Steam and caustic peeling are also used by apple processors; however,
these methods are more successful in manufacturing a sauce product than
with a sliced product. The peel loss is not as great in caustic peeling
when compared to mechanical peeling. It is often desirable to remove a
greater percentage of the peel in the manufacture of slices or sauce to
ensure the complete elimination of surface imperfections.
The peel removed by caustic treatment cannot be utilized in cider
manufacture, but the core, if properly handled, is still suitable for
use as a raw material for cider processing. In the steam and caustic
type peelers, the final removal is accomplished by a rotary washer using
water sprays. A few of the apple processors have installed abrasive
21
-------
type scrubbers to replace the conventional rotary washers. The peeling
and coring operations represent a major source of waste to the apple
processing industry and, wherever possible, operating procedures should
be used to minimize the contact between cut portions and wash water to
reduce the amount of soluble constituents lost to the waste effluent. A
certain amount of water is still required to prevent browning of the
apple particles.
~ *f fresh apple slices are the end product, these slices can be
cut after the core has been removed or simultaneously as the apple is
being cored. The apple slices are washed, graded and inspected before
packaging as fresh apple slices or further processed into dehydrated,
frozen, or canned products.
Deaerating - If the apple slices are to be either frozen or canned, they
are deaerated by immersion in a brine solution while a vacuum is pulled
on the tank. The brine is then drained from the slices which are then
either frozen and packaged or cooked prior to canning.
~ In tne canning of apple slices, the slices are steam blanched
or pre-heated, placed into the can while still hot, sealed, and further
cooked to assure preservation,
Product Styles
~ APPle slices are processed from solid fresh apples of proper
maturity and proper ripeness. After the apples are washed, sorted,
peeled and cored, they are sliced by cutting segments longitudinally and
radially from the core centerline. The slices are further inspected and
packaged for immediate use as a fresh product, or they can be dehydrated
in a tunnel drier and packaged as dehydrated apple slices. If either a
frozen or canned product is required, the apples are deaerated prior to
processing.
£>auce - Apple sauce is prepared from comminuted or chopped apples which
may or may not have been previously peeled and cored. In addition to
removal of the peel and core, good manufacturing practice dictates the
separation of bruised apple particles, carpel tissue and other coarse
hard extraneous materials. The apples are washed, sorted, cored and
peeled in a manner identical to the manufacture of slices. Flavor and
consistency are adjusted with water and sugar, generally in the form of
liquid sugar.
The cored apple is sliced or diced into small pieces, cooked and, while
still hot, passed through a finisher for removal of any large foreign
particles. The hot apple sauce from the finisher is inspected, and any
remaining foreign particles are removed prior to canning and cooling.
Appj-e __ Juice ___ (Ciderj_ - Apple juice (cider) is an unfermented liquid
prepared from~l) ""fresh whole sound apples or 2) apple pieces such as
22
-------
cores and peelings obtained from either a slice or a sauce manufacturing
operation. If whole apples are used, they are washed and comminuted
before pressing. The pressed juice is screened to remove large foreign
particles and frequently clarified by diatomaceous earth pressure
filtration. The apple juice is then heated to assure preservation of
the product in hermetically sealed containers.
A concentrated apple juice can be made from the single-strength juice
through the removal of water (evaporation). The concentrate is stored
or packaged in bulk containers (55-gallon drums). In the manufacture of
apple juice (cider), it is not customary to either peel or core the
apple. Consequently, there is not the large amount of waste being
discharged at this portion of the process.
Vinegar stock is made in a manner similar to the pressing of apple
cider. However, the vinegar stock is made from poor quality apples. It
is never clarified to the same degree as apple cider; however, it is
usually concentrated prior to bulk shipment in tank cars to the vinegar
processing plant.
Citrus
General
The citrus industry is concentrated in two areas of the U.S. The major
portion, approximately 80 percent of the industry, is located in Florida
and the remaining 20 percent is located in the southwestern part of the
U.S. (California, Arizona and Texas). Oranges, grapefruit, lemons,
tangerines (mandarins) and limes, ranked in the order of importance, are
all processed into citrus products and co-products such as juice, dried
peel, oil, segments and molasses. A few citrus processors also
manufacture such items as pectin, flavorings, essence, Pharmaceuticals,
etc. Citrus juice, single-strength and concentrated, is by far the
major product of the citrus processing industry.
Citrus is both harvested and processed only in four states; Florida,
California, Texas and Arizona. In the eastern area, Florida, 90 percent
of all fruit picked is sent directly to the processing plant. Only 10
percent of the fruit harvested in this area is directed to the packing
house where it is graded, and the poorer quality fruit is redirected to
the processor. In the southwestern region of the U.S. (California,
Arizona and Texas) normally all fruit is sent first to a packing house,
where the fruit is graded for the fresh-table market, and the remaining
fruit is then sent to the processor. The only exception to this
procedure occurs when, because of low temperatures in a given area, the
fruit on the trees becomes frozen. In an effort to salvage as much of
the fruit as possible, the frozen fruit is immediately picked and
shipped directly to the processor as f_ield run fruit.
23
-------
Processing Steps
There are a number of similar or identical process steps in the
manufacture of most citrus products. For example, the receiving,
washing, intermediate storage, extraction and finishing process steps
are common to all single strength juice plants. In addition, the juice
concentrating process step must be added for the production of a frozen
concentrate. In the manufacture of citrus segments the process steps
which are common to all citrus segment plants are mechanical peeling,
caustic treating, sectionizing, canning or bottling, and cooling. The
peel and pulp (including rejected fruit) are processed into a dried
citrus pulp and a molasses. These can be marketed as separate items or
the molasses can be added back to the dried citrus pulp.
Receiving/Storage/Washing - When the fruit is received at the processing
plant, it is transferred to intermediate storage prior to processing.
This storage is usually sized to hold one to three days supply of fruit
for the plant. When needed, the fruit is withdrawn from storage and
washed before processing to remove any foreign materials including
pesticides and insecticides that are adhering to the fruit. Either high
pressure water sprays or immersion in water, in combination with brush
scrubbers, is the conventional method of fruit cleaning. All free
surface water must be drained from the fruit prior to extracting the
juice.
Extraction - In this process step the raw citrus juice is extracted from
the fruit by mechanical methods. In a reamer type extractor, the fruit
is cut into halves and each half reamed separately to remove the juice.
In another system the juice is extracted from the whole fruit through a
hollow tube while pressure is applied to the exterior surface of the
fruit. In another procedure, the fruit is sliced and the juice removed
from the fruit halves by pressure on the exterior of the fruit. An
average yield of juice is 480 1/kkg (115 G/T) of fruit processed.
Finishing - Mechanically extracted juice contains seeds, pips and
segment membranes (rag) that must be removed. This separation is
usually accomplished by a screw or paddle type finisher (pulp press)
where the pressure applied and the size of the perforations (openings)
control the degree of solids removal. The finished juice is blended and
ready for canning or bottling as a single strength juice.
A fruit base drink can be manufactured by washing the citrus pulp solids
discharged from the finisher with water and separating the solids in
another finisher. The washed pulp is transferred to the peel process.
JjSi2§_£2G£§Si£S£i22 ~ In concentrating citrus juice to 42° or 65° Brix,
it is necessary to remove practically all of the pulp solids. If the
finisher cannot be adjusted to remove a sufficient quantity of solids,
then it is necessary to desludge the single strength juice in a
centrifuge. The removal of solids reduces the viscosity of the juice
24
-------
during the concentration procedure. The citrus juice is concentrated in
evaporators (rising or falling film) that have been designed for
operation at a high vacuum and a short residence time. If citrus
essence is to be recovered from the juice, this must be accomplished
during the concentrating of the raw citrus juice.
" In this process step the peel is mechanically removed from the
fruit. First the fruit is scalded with steam and cooled to loosen the
peel. The fruit is manually placed or positioned into a receiving cup
of the mechanical peeler, and is retained in the cups while the peel is
scored and mechanically stripped from the fruit. The peel is trans-
ferred to the peel process part of the plant or sold to other
processors.
Caustic __ Treatment - A caustic solution is applied to the whole peeled
fruit by dipping or spraying. The caustic treatment removes any
adhering rag or membrane prior to sectionizing. After treatment, but
prior to sectionizing, all liquid caustic is thoroughly removed from the
fruit by washing with water.
Segmenting - The segmenting process is either a manual or a mechanical
operation. The manual or hand method produces a higher quality segment
with less waste being generated than with the automatic sectioning
machines. The sectioned fruit is inspected and packaged in cans or
bottles.
Peel Shaving - A number of the citrus processors quarter and shave the
peel~to recover the citrus oil. This cold pressed oil is a valuable co-
product if lemons or grapefruit are being processed. Mandarin and
orange oils are of lesser commercial importance. To release the oil
from the peel, the citrus halves are quartered and passed between
knurled pressure rolls to break the oil sacs in the peel. A
recirculated water stream is sprayed into the shaver to pick up the
citrus oil being released from the shaved peel.
Citrus peel may also be shaved or deragged to produce a peel product
acceptable for drying and ultimate use as a food ingredient (cake mixes,
orange marmalade) .
Products and Co- products
In a large citrus processing plant a number of the products or co-
products will be made. Process descriptions of the more important
products are outlined below.
Single Strength Juice - In this process, the raw juice is extracted from
the "fruitT" The suspended solids (seeds, pulp, etc.) are then removed
from the raw juice in a paddle or screw type finisher. The filtered
juice from the finisher is blended and bottled for sale as a fresh
chilled juice or pasteurized and canned as a single strength juice,
25
-------
Processing Steps
Most potato processes have a number of steps which are common to the
manufacture of potato products, i.e., storage, washing, peeling,
slicing, and blanching, followed by a further processing step in which
the final product character is determined.
Storage - To achieve maximum use and efficiency of his manufacturing
facilities, the processor attempts to operate his plant on a year-round,
continuous basis. Thus, it is necessary for large quantities of
potatoes to be placed into storage at the end of each harvest for future
use. The potatoes are often stored for many months prior to use.
Today, below-ground storage systems - cellars - are gradually being
abandoned in favor of above-ground construction. In either instance, it
is necessary to maintain a high relative humidity to prevent dehydration
of the stored potatoes, shrinkage during long-term improper storage can
result in a 90 percent water loss by evaporation and a 10 percent
carbohydrate loss by respiration. However, proper temperature control
and air recirculation will prevent these losses as well as prevent the
occurrence of blackheart, mahogany browning, and stem rot.
Receiving/Washing - The potatoes that are received from the storage
cellar or field are directed into a water flume or transport system by
high pressure water hoses. In this manner the potatoes are withdrawn
from the intermediate plant storage and transported to the processing
area. The potatoes are withdrawn from the flume system by means of a
metering wheel and fed into the process system. The transport water is
normally pumped to a settling basin for silt removal and then returned
to the receiving system.
Prior to processing, it is necessary to wash the potatoes. This is
accomplished by passing the potatoes through a rotary drum or
cylindrical washer where the potatoes are scrubbed either with brushes
or merely by tumbling them together. In this washing operation the
potatoes are also subjected to water sprays for the removal of foreign
material and soil particles. Following the rotary washer the potatoes
pass over a short drainage belt which permits internal recirculation of
the wash water. An inspection of the potatoes is made on the drainage
belt, and the undesirable whole potatoes are removed.
Peeling - There are a number of methods for the removal of peel from the
potato. These methods usually involve a pretreatment with chemicals
(lye) or heat (steam), which are followed by water sprays, abrasive
rolls or rubber studded rolls to remove the peel from the potato. The
peel loss, including trimming, can result in 15 to 30 percent loss of
the potatoes processed. The combination of the above peeling methods
has resulted in four systems which are known in the industry as abrasive
peeling, steam peeling, lye (caustic) or wet lye peeling and dry caustic
peeling. All these methods can be designed as either a continuous or a
28
-------
batch system. No simple peeling method provides the highest degree of
peel removal for all potato products or raw potato types.
Abrasive peelers have rough coated rolls which rotate and remove the
peel and small portions of the tissue by mechanically abrading it from
the surface of the potato. Water sprays are used to remove the
particles of peel from the abrasive rolls and the peeled potato. The
potatoes are also rotated to insure removal of peel from all sides of
the potato. Abrasive peeling is normally employed in the manufacture of
potato chips. In this style of product it is not essential to have
complete peel removal.
Steam peelers expose the potatoes to high pressure steam for short
periods of time. After the steam treatment the potatoes are brushed and
sprayed with water to remove the cooked peel particles. Steam peeling
is an excellent procedure for producing a completely peeled product and
is extremely effective on new or thin skinned potatoes.
Lye (caustic) peelers immerse or dip the potatoes in a hot lye solution.
Longer immersion times are required at lower temperatures and the lye
consumption increases with higher caustic concentrations. After removal
from the hot lye solution, the potatoes are held for a short period of
time to allow for the softening of the peel. The loose peel is then
removed by brushes and water sprays in a manner similar to the removal
of peel after steaming. If caustic treatment is used, the potatoes must
be thoroughly washed to remove all traces of caustic along with the peel
prior to further processing of the potato.
Dry caustic peelers are a recent modification of lye peelers. In this
peeling process the potatoes are treated with a lye solution and after
removal of the excess lye solution by draining, the potatoes are exposed
to infrared heating. The caustic treated peel which has been loosened
is removed by an abrasive scrubber utilizing one-half-inch-long rubber
studs on rapidly rotating cylinders developed by the USDA Western
Utilization Research Laboratory. The peel is removed in this abrasive
scrubber with minimal rinsing. This method of peel removal has the
beneficial effect of substantially reducing the volume and organic
strength of the waste streams. In actual plant operation, the peelings
are collected as a slurry having a 15 to 25 percent solids content.
A recent extension of this new development in peel removal has been to
use the abrasive scrubber (USDA design) with other types of peel
treatment. A similar reduction in waste loads has been realized when
this scrubber has been employed with steam peelers or the conventional
lye peelers. The reduction in water volumes and waste loads is
equivalent to that attained when the scrubber is used in the dry caustic
peeling system.
The trimming process should be considered as part of the peel removal.
In this process the presence of eyes, blemishes, and remaining peel are
29
-------
often detected electronically, which directs the imperfect potato to
the trim table where the imperfections are manually cut out of the
potato. The degree of completeness of trimming is usually determined by
the desired end product or style. All solid wastes from either trimming
or peeling can be directed toward cattle feed.
Slicing/Dicing - In this process step, slicing or dicing, the potato is
cut or subdivided into smaller pieces. The size and shape into which
the potato is subdivided is dependent upon the end product. In any
cutting process a number of potato cells are ruptured, releasing
considerable amounts of starch. The more extensive the cutting, the
greater the amount of starch that is released. This starch is washed
from the surface of the potato pieces and usually appears in the
transport or cutting water.
Many processors are now installing hydroclones to remove the starch in
the form of a slurry from the wash water. This crude starch slurry is
then shipped to a starch processor for further refining.
SilSStiiQS ~ After peeling and slicing the potato, the pieces are
blanched to deactivate the enzymes, to remove surface air, to partially
cook to form a grease barrier on the particle and if necessary to remove
excessive sugars. Blanching also can be used to effect a degree of
sterilization. Either steam or water is used for blanching potatoes.
Steam is used when it is necessary to minimize leaching; water blanching
is employed when it is necessary to remove constituents such as sugars
from the potato pieces. It is common practice to arrange the blanchers
for series flow of the potato pieces and parallel flow of the hot
blanching water. For dehydrated potato products, the potato pieces are
water- blanched, water-cooled, and then steam-blanched or cooked prior to
mashing and mixing.
Product Styles
Following the blanching process, the potatoes can be further processed
into products of two major categories: frozen and dehydrated.
Frozen Potato Products (French __ Fries,, __ Hash __ BrownA ___ §££_•.]_- In
manufacture of frozen potato products, many processors add back
ingredients after blanching and prior to frying and cooking. The frying
is accomplished in a continuous belt unit at a temperature of 300° to
350°F. Following frying, the potato pieces are quick frozen in a tunnel
freezer, then inspected, sorted and sized prior to packaging and
warehousing. The only waste loads which are generated from this portion
of the process are wastes from the fryer-scrubber, clean-up of the fryer
and freezer belts, freezer thawing, cooling water, etc.
Dehydrated Potato Products __ (Granules, Flake stn Slices) - The potato
slices or dices which are dehydrated as individual pieces are dried
30
-------
following blanching in an atmospheric recirculated air tunnel or
conveyor drier. If granules or flakes are to be processed, then the
blanched potato pieces are mashed and conditioned prior to drying as
flakes on a drum drier (flaker) or as granules in a fluid bed drier.
31
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-------
SECTION IV
INDUSTRY CATEGORIZATION
CATEGORIZATION
In developing waste water effluent limitation guidelines and standards
of performance for the Canned and Preserved Fruits and Vegetables
Industry, a judgment must be made as to whether limitations and
standards are appropriate for different segments (subcategories) within
the industry. The first phase of the study is limited to processors of
apple products (except caustic peeled and dehydrated products), citrus
products (except pectin and pharmaceutical products) and frozen and
dehydrated potato products. Other commodities will be studied in a
subsequent study. In order to identify any such subcategories, the
following factors were considered.
1. Raw material
2. Products and by-products
3. Production processes ,
U. Age of plant
5. Size of plant
6. Plant location
7. Waste treatability
After considering each of these factors, it was concluded that the
segment of the Canned and Preserved Fruits and Vegetables industry
included in this study consisted of three different raw materials:
apples, citrus, and potatoes. The apple and potato processing
industries were further subdivided into two subcategories each. The
subcategorization selected for the purpose of developing waste water
effluent limitations guidelines and standards are as follows:
1. Apple Processing: Apple Juice
2. Apple Processing: Apple products except juice
3. Citrus Processing: All products
4. Potato Processing: Frozen products
5, Potato Processing: Dehydrated products
The differences in raw waste characteristics for the five subcategories
are given in Table 5. The rationale for this subcategorization is
detailed throughout the remainder of this section.
33
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TABLE 5
DISTRIBUTION OF WASTE LOAD BY SUBCATEGORY
PRODUCT STYLE
APPLE PROCESSING
Apple Juice
Apple Products
except juice
Flow
1/kkg
AVERAGE(RANGE)
2880(1880-3540)
5360(1380-14800)
gal/T
AVERAGE(RANGE)
CITRUS PROCESSING
All Products 10120(710-24940)
2425(170-5980)
POTATO PROCESSING
Frozen Products 11300(4090-15510) 2710(975-3725)
Dehydrated
Products 8761(6530-12010) 2100(1565-2880)
BOD
kg/kkg
AVERAGE(RANGE)
Ib/T
AVERAGE(RANGE)
Suspended Solids
kg/kkg Ib/T
AVERAGE(RANGE) AVERAGE(RANGE)
690(450-850)
1290(330-3550)
2.05(1
6.4(3.
.6-2.
4-10.
55)
1)
4
12
.1(3
.8(6
.2-5.
.8-20
1)
.2)
0.3(0
0.8(0
.15-0
.35-1
.40)
.05)
0.6(0.3-0.8)
1.6 (0.7-2.1)
3.2(0.45-8.5)
6.4(0.9-17.0)
1.3(0.02-7.95)
2.6(0.04-15.9)
22.9(4.45-36.95) 45.8(8.9-73.9)
11.05(7.75-15.2) 22.1(15.5-30.4)
19.4(5.1-45.5) 38.8(10.3-91.0)
7.35(3.8-12.15) 14.7(7.6-24.3)
-------
TABLE 6
EFFECT OF LOCATION FOR VARIOUS APPLE PLANTS
(OTHER THAN JUICE ONLY PLANTS)
BOD
LOCATION
East
West
NUMBER
PLANTS
6
3
kg/kkg
AVERAGE(RANGE)
5.75(1.4-8 .5)
6.5 (3.4-10.1)
Ib/T
AVERAGE(RANGE)
11.5(2.8-17.0)
13.0(6.8-20.2)
FLOW
East
West
6
3
1/kkg
AVERAGE(RANGE)
2290(1790-2790)
2640(1190-6050)
gal/T
AVERAGE(RANGE)
550(430- 670)
630(285-1450)
37
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TABLE 7
EFFECT OF RAW MATERIAL AT VARIOUS CITRUS PLANTS
FLOW
BOD
RATIO OF
GRAPEFRUIT /ORANGES
0.50 -- 1.00
0. 20
0.15
0.00
— 0
— 0
— 0
.49
.19
.14
NUMBER
PLANTS
4
6
2
3
1/kkg
AVERAGE (RANGE)
5675(1630-9090 )
8220(2085-16180)
14330(9590-19060)
7260(1360-8010)
gal/T
AVERAGE (RANGE)
1360( 395-2180)
1975( 500-3880)
3435(2300-4570)
1740( 325-1920)
kg/kkg
AVERAGE (RANGE)
3.1 (0.7-6.7)
3
1
4
.75(1
.95(1
.05(1
.4-6
.6-2
.3-8
.4)
.3)
.25)
Ib/T
AVERAGE (RANGE
6.2(1
7.5 (2
3.9(3
8.1(2
.4-13.4)
.8-12.8)
.2- 4.6)
.6-16.5)
Ul
CD
-------
TABLE 8
EFFECT OF RAW MATERIAL MIX AT CITRUS PLANT 123 (MARCH, 1970)
GRAPEFRUIT/ORANGES
0
0
0
21
36
54
57
59
65
CAPACITY
kkg/Day Tons/Day
1870 2065
1480 1630
420 465
1890 2080
1970 2170
1430 1580
1620 1780
1170 1290
1220 1345
BOD
BOD
V o / Tl ^ v
K. g / U a. y
5830
13250
235
10340
10310
2450
11480
2100
3680
Ib/Day
12845
29190
515
22770
22710
5405
25280
4635
8105
kg/kkg
3.1
8.95
0.55
5.45
6.15
1.7
7 .1
1.8
3.0
Ib/T
6.2
17.9
1.1
10.9
12.3
3.4
14.2
3.6
6.0
-------
TABLE 9
EFFECT OF LOCATION FOR VARIOUS CITRUS PLANTS
BOD
NUMBER kg/kkg Ib/T
LOCATION PLANTS AVERAGE(RANGE) AVERAGE(RANGE)
Florida 25 3.05(0.45-8.5) 6.1(0.9-17.0)
California 2 5.3 (2.35-8.25) 10.6(4.7-16.5)
-------
TABLE 10
LOCATION
West
East
NUMBER
PLANTS
9
3
EFFECT OF LOCATION FOR VARIOUS POTATO PLANTS
(FROZEN POTATO PRODUCTS)
FLOW
1/kkg gal/T
AVERAGE(RANGE) AVERAGE(RANGE)
12490(10350-15520)
10210( 9640-10890)
2990(2480-3720)
2450(2310-2610)
BODS
kg/kkg Ib/T
AVERAGE(RANGE) AVERAGE(RANGE)
25.25(12.3-36.95) 50.5(24.6-73.9)
21.9 (11.0-29.25) 43.8(22.0-58.5)
-------
Products and By-Products
There is not a primary product that relates apples to citrus to
potatoes. The primary product from apples is applesauce; the primary
product from citrus is juice; and the primary product from potatoes is
frozen french fries.
The differences in primary product styles emphasize the diversity of
industry practices within the apple, citrus, and potato segment of the
industry. Never-the-less, it is important to compare waste loads from
various products and product mixes to determine whether plants can be
grouped on a basis of similar raw waste characteristics.
The apple product styles considered included slices, sauce and juice or
cider. The processing of slices or sauce is similar up to the final
step of either canning, freezing or dehydrating. The difference in
contributions of the final operation to waste water production and waste
characteristics is small. Table 11 compares the waste characteristics
for various apple product styles. Three apple juice plants have an
average BOD of 2.05 kg/kkg (4.1 Ib/T). The average BOD for five other
apple products and product mixes were similar. The average BOD values
ranged from a low of 2.05 kg/kkg (4.1 Ib/T) to a high 6.85 kg/kkg (13.7
Ib/T). While these BOD values are similar to each other, they are
significantly different from the BOD from juice processing. The water
usages are similar regardless of apple product or product mix although
one flow value is high due to excessive water usage at one of three
plants in the group. Thus, similarity of flow and BOD allow all apple
products except juice to be grouped in a single subcategory. The large
BOD differences of these plants with juice plants requires separate
categories.
The citrus product styles considered included juice and segments. Oil
recovery and peel processing to cattle feed are considered co-products.
Some plants usually produce only juice. The waste peel problem is met by
shipping the peel to other processors for conversion to cattle feed or,
in rare cases, the peel is disposed of as solid waste. Citrus segments
are manufactured as a specialty product along with the normal production
of citrus juice. The better quality fruit is used in the processing of
segments while the poorer quality of fruit is directed to juice
manufacture. The conversion of the citrus peel to cattle feed also
solves an otherwise difficult disposal problem. The recovery of citrus
oil is widely practiced in the industry. This oil is recovered from the
surface of the peel as a cold-pressed oil. Highly contaminated waste
streams are produced as part of the oil recovery process, and care must
be taken to keep oil out of biological treatment systems. It is common
practice in the larger plants to recover oil/water waste as a sludge and
dispose of it through the waste heat evaporator. Although the citrus
peel manufactured into cattle feed is considered a by-product, there is
a strong economic incentive to produce this product.
42
-------
Table 12 compares the BOD for various citrus products and product and
co-product mixes. Seven different product styles have an average BOD
from 3.15 to 3.5 kg/kkg (6.3 to 7.0 Ib/T). The water usages are also
similar for the various products considering the wide range in data.
Thus, the similarity of raw waste characteristics among various citrus
products and co-products confirm a single citrus processing category.
Within potato processing, two products were considered: frozen and
dehydrated products. It was shown earlier that processing of frozen or
dehydrated apples was similar up to the final operation and that only
minor waste differences occur. There are, however, differences between
dehydrated and frozen potato processing (See Sections III and V). Table
13 compares the BOD and flow for frozen potato products with dehydrated
products. There are significant differences in BOD 11.05 and 22.9
kg/kkg (22.1 and U5. 8 Ib/T) .
Three plants producing both frozen and dehydrated styles were also
considered. At one plant complete 1972 data was available. The annual
raw potato mix to frozen and dehydrated products was used to calculate
the waste load using the average BOD for frozen and dehydrated products
(Table 13). The calculated BOD value of 14.95 kg/kkg (29.9 Ib/T)
compared satisfactorily with its actual value of 13.8 kg/kkg (27.6 Ib/T)
(Table 13). Thus, the waste characteristics indicate two separate
categories for potato processing.
Table 5 summarizes the raw waste load and water usage for each of the
five product subcategories determined above. The citrus processing BOD
is similar to the BOD from the two apple subcategories but different
from the two potato subcategories. The citrus processing flow is
similar to the water usage from the two potato subcategories but
different from the two apple subcategories. This data confirms that
five subcategories are needed for the purpose of developing effluent
limitation guidelines and standards.
Production Processes
Industrial processing practices within the fruit and vegetable industry
are diverse and produce different waste loads. However, final products
relate directly to the processes employed and since final products have
been previously used for subcategorization, the many differences and
similarities in production processes support the five industry
subcategories. There are a few processing differences that occur within
these subcategories and these must be considered to determine their
effect on raw waste loads and categorization.
In apples, two different peelers are used. The mechanical peelers are
the most popular. The peeler can be adjusted to remove a greater or
lesser percentage of the fruit imperfections and the resulting peel and
core can be collected and used in the production of juice. Caustic
43
-------
peelers are also used by apple processors. The peel loss is not as
great in caustic peeling when compared to mechanical peeling. The
resulting peel waste, however, cannot be utilized in juice or cider
manufacture. However, sufficient data is not available to evaluate the
effect of caustic peelers on waste waters from the apple industry.
Therefore, apple processors utilizing caustic peelers will be considered
in a later study.
In the citrus industry there are variations in the extracting equipment
used. Large plants may in fact use more than one style of machine in a
given process step. Citrus waste loading data does not show differences
attributable to the different machines. Another process variation
within the citrus industry is the utilization of waste heat evaporators.
Many large citrus plants use the exhaust gases from the meal dryer to
supply heat for the concentration (recovery) of high strength wastes
(such as press liquor) in the waste heat evaporator. Table 14 compares
the average BOD from plants with waste heat evaporators to plants
without the evaporator. The result is interesting in that the average
BOD is a little higher when the waste heat evaporator is present.
However, the similarity in the average and BOD range is sufficient to
confirm the citrus categorization without regard to presence or absence
of the waste heat evaporator.
Other than variations in production processes which are associated with
product style, the only process step exhibiting significant variations
in waste production in potato processing is that of peeling. Peeling
methods may be placed in four groups; wet lye, dry lye, steam, and
abrasion. Several historical publications have associated different
waste loadings with different peeler types. However, recent equipment
developments such as a low water usage scrubber used for separating
softened peel have resulted in lower waste loads than older peeler
installations using water sprays for peel removal.
Table 15 attempts to differentiate various peeling methods from total
raw waste characteristics. Limited data indicates that BOD effluents
from wet caustic systems can be reduced by a low water usage scrubber
and that caustic systems followed by a USDA scrubber can reduce the BOD
further. However, the BOD and water usage data in Table 15 cannot
differentiate peeler methods. Therefore, further subcategorization by
peeler method is not possible.
Thus, production processes are either associated with final product
style or do not have an important impact on categorization.
Accordingly, production processes support the five industry
subcategories developed earlier.
1414
-------
Age of Plant
The age of a plant is somewhat difficult to define. Some processors
give the date of the founding of the company, which may bear little
relationship to the age of the processing equipment. The average age of
the old plus the new process equipment is more meaningful, although the
average of very old and very new equipment is less meaningful. The
industry is competitive, so that older units that prove to be
inefficient are usually replaced. No correlation was found between any
measures of plant age and waste character or water usage.
Size of Plant
The size of an apple, citrus, and potato plant is important from a
technical as well as an economical standpoint. A small plant may not
have as many end-of-process treatment alternatives as a large plant, but
may have more in-plant control alternatives than a large complex plant.
The importance of size has been realized in the fruits and vegetables
industry and size has been thoroughly considered in this categorization.
Table 16 compares waste character and water usage for apple plants with
capacity less than 9.1 kkg per hour (10 T/hr.) and capacity greater than
9.1 kkg/hr. (10 T/hr). Only apple plants whose only product is juice
are omitted. The BOD for the two plant sizes are very close 5.9 and
6.15 kg/kkg (11.8 and 12.3 Ib/T) . The ranges of BOD are also similar.
There is a large difference in water usage but this difference is
attributable to a single plant with high water flows. Thus,
similarities in raw waste load suggest apple plant size does not have an
impact on categorization.
Table 17 compares various citrus plant sizes with waste character (BOD)
and water usage. The initial comparison is between plants with
capacities greater or less than 320 kkg/day (350 T/day). The
differences in BOD 3.2 and 3.3 kg/kkg (6.4 and 6.6 Ib/T) and water
usage 8,390 and 10,600 1/kkg (2010 and 2540 gal/T) are not considered
significant especially in view of the large ranges of BOD and flow data.
The second comparison is between plants with a capacity of 910 to 2000
kkg/day (1000 to '2200 T/day) and plants with a capacity less than 910
kkg/day (1000 T/day) or a capacity greater than 2000 kkg/day (2200
T/day) . Again, the variability of the data is large and the similarity
of average BOD and flow values suggest citrus plant size does not have
an important impact on categorization.
Table 18 compares various potato plant sizes with waste character (BOD)
and water usage. Frozen and dehydrated products are considered
individually. Comparisons for frozen potato products include plants
with capacity greater than and less than 360 kkg/day (400 T/day) and
also 450 kkg/day (500 T/day). Neither the differences in BOD or water
usage appears to be important. The variability of the data and the
impact of a single plant is shown by the high average BOD (25.65 kg/kkg
45
-------
(51.3 Ib/T) ) for plants with capacity less than 360 kkg/day (400 T/day)
and low BOD 20.35 kg/kkg (40.7 Ib/T) for plants with capacity less than
450 kkg/day (500 T/day). Comparisons for dehydrated potato products
include plants with capacity greater than and less than 360 kkg/day (400
T/day) as well as 450 kkg/day (500 T/day). There are apparent
differences in BOD and flow for small and large plants but the
variability of BOD and flow data as well as the limited data base (seven
plants) must be considered. Also, higher flows are observed at plants
with lower BOD values and lower flows with plants with higher BOD so
that treatment design differences which would influence capital costs
are less important. In summary, no correlation exists between waste
characterization and water usage data and size of dehydrated potato
plants.
It is therefore concluded that size of plant is not a satisfactory basis
for further industry subcategorization.
Plant Location
It is reasonable to expect that plant location could affect the
selection of waste treatment alternatives for any plant in the fruits
and vegetable industry. If the technical and economic feasability of
achieving an effluent reduction is dependent on plant location, then
additional subcategories must be established. In the earlier discussion
of raw material, it was determined that geographical location did not
affect the raw waste loading for either apples or citrus or potatoes
(See Tables 6, 9 and 10). However, in this section availability of
land, climate, and of high quality water is evaluated to determine their
effect on effluent reduction for apple, citrus, or potato plants.
Spray or flood irrigation is used throughout the apple, citrus, and
potato subcategories. Irrigation requires relatively large amounts of
land , but where inexpensive land of acceptable character is available,
spray irrigation may be the least expensive solution to waste disposal
problems. Biological systems such as activated sludge require much less
land than spray irrigation, but the amount of land required could be
difficult and expensive to acquire for a plant located in an urban area.
In general, however, plants located in urban areas are served by
municipal sewers. Land availability requirements will influence the
choice of treatment technology to be used in a particular situation.
However, sufficiently high levels of treatment are achievable with
treatment processes which are not land-intensive. Thus, availability of
land does not seriously affect the achievement of a high level of
effluent reduction for apple, citrus, or potato plants.
46
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TABLE 11
AVERAGE (RANGE) OF BOD AND FLOW FOR VARIOUS APPLE PRODUCT STYLES
PRODUCT STYLE
FLOW
NUMBER 1/kkg gal/T
PLANTS AVERAGE(RANGE) AVERAGE(RANGE)
BOD
kg/kkg Ib/T
AVERAGE(RANGE) AVERAGE(RANGE)
Juice
Sauce
Sauce
Apple
Only
Only
& Juice
Products
3
3
3
9
2880(1880-3540 )
3400(1380-6050)
1690(1190-14800)
3920(1190-14800)
690(450- 850)
815(330-1450)
405(285-3550)
940(285-3550)
2
5
6
6
.05(1
.35(3
.85(5
.0 (1
.6- 2
.4- 7
.8- 8
.4-10
.55)
.5 )
.5 )
.1 )
4
10
13
12
.!( 3.
.7( 6.
.7(11.
.0( 2.
2- 5.1)
8-15.0)
6-17.0)
8-20.2)
(except Juice Only)
All Apple
Products
Slices with
Apple Products
12 3660(1190-14800) 875(285-3550)
3 6635(1790-14800) 1595(430-3550)
5.0 (1.4-10.1) 10.0(2.8-20.2)
5.85(1.4-10.1) 11.7(2.8-20.2)
-------
TABLE 12
AVERAGE(RANGE) OF BOD AND FLOW FOR VARIOUS CITRUS PRODUCT STYLES
PRODUCT STYLE
Segments Only
NUMBER
PLANTS
Citrus Products
without Segments 19
Citrus Products
with Segments 6
Citrus Products
without Oil 5
Citrus Products
with Oil 22
Citrus Products
without Feed 9
Citrus Products
with Feed 18
All Products 27
FLOW
1/kkg
AVERAGE(RANGE)
gal/T
AVERAGE(RANGE)
BOD
kg/kkg Ib/T
AVERAGE(RANGE) AVERAGE(RANGE)
7455(4340-10570) 1790(1040-2535) 3.5 (2.65-4.35) 7.0(5.3- 8.7)
10160( 710-24950) 2440( 170-5980) 3.15(0.45-8.5 ) 6.3(0.9-17.0)
10850(4380-19180) 2600(1050-4600) 3.3 (1.4 -5.6 ) 6.6(2.8-11.2)
7570(4340-10570) 1820(1040-2535) 3.35(1.45-5.6 ) 6.7(2.9-11.2)
10690( 710-24950) 2560( 170-5980) 3.2 (0.45-8.5 ) 6.4(0.9-17.0)
7570(1630-24950) 1820( 390-5980) 3.15(0.7 -6.4 ) 6.3(1.4-12.8)
11380( 710-24740) 2730( 170-5930)
10110( 710-24950) 2425( 170-5980)
3.25(0.45-8.5 ) 6.5(0.9-17.0)
3.2 (0.45-8.5 ) 6.4(0.9-17.0)
-------
TABLE 13
AVERAGE (RANGE) OF BOD AND FLOW FOR VARIOUS POTATO PRODUCT STYLES
PRODUCT STYLE
Frozen Products
FLOW
NUMBER 1/kkg gal/T
PLANTS AVERAGE(RANGE) AVERAGE(RANGE)
13
BOD
kg/kkg Ib/T
AVERAGE(RANGE) AVERAGE(RANGE)
11320(4090-15510) 2710( 980-3720) 22.9 (4.45-36.95) 45.8( 8.9-73.9)
Dehydrated Products
8770(6530-12010) 2100(1565-2880) 11.05( 7.75-15.2) 22.1(15.5-30.4)
Frozen & Dehydrated
Products 3
9260(6380-12800) 2220(1530-3070) 13.8(13.65-13.95) 27.7(27.3-27.9)
All Potato Products 23
10270(4090-15510) 2460( 980-3720) 18.1 (4.45-36.95) 36.2( 8.9-73.9)
-------
TABLE 14
EFFECT OF WASTE HEAT EVAPORATOR FOR VARIOUS CITRUS PLANTS
BOD
WASTE HEAT
EVAPORATOR
Present
Absent
Present
Absent
NUMBER
PLANTS
10
17
10
17
kg/kkg
AVERAGE (RANGE)
3.25(0.45-8.5 )
3.2 (0.7-8.25)
FLOW
1/kkg
AVERAGE (RANGE)
10500( 710-19970)
9800(1360-24950)
Ib/T
AVERAGE (RANGE)
6.5(0.9-17.0)
6.4(1.4-16.5)
gal/T
AVERAGE (RANGE)
2520(170-4790)
2370(325-5980)
50
-------
TABLE 15
AVERAGE (RANGE) OF BOD AND FLOW FOR VARIOUS POTATO PEELERS
(FROZEN PRODUCTS ONLY)
PEELER TYPE
Wet Caustic
Wet Caustic
NUMBER
PLANTS
5
& 2
FLOW
1/kkg
AVERAGE (RANGE)
12120(10430-14560)
11890(10350-13430)
gal/T
AVERAGE (RANGE)
2900(2500-3490)
2850(2480-3220)
BOD
kg/kkg
AVERAGE(RANGE)
Ib/T
AVERAGE(RANGE)
26.05(15.1 -36.95) 52.1(30.2-73.9)
26.5 (20.75-32.25) 53.0(41.5-64.5)
USDA Scrubber
Dry Caustic &
USDA Scrubber
12810(10100-15520) 3070(2420-3720)
2 8. 7 ((25. 45-31. 95) 57.4(50.9-63.9)
-------
TABLE 16
AVERAGE (RANGE) OF BOD AND FLOW FOR VARIOUS APPLE PLANT SIZES
(OTHER THAN JUICE ONLY PLANTS)
SIZE
NUMBER
PLANTS
Less than
9.1 kkg/hr (10TPH) 4
Over
9.1 kkg/hr (10TPH) 5
FLOW
1/kkg Gal/1
AVERAGE(RANGE) AVERAGE(RANGE)
BOD
kg/kkg Ib/T
AVERAGE(RANGE) AVERAGE(RANGE)
6360(17?5-14810*) 1520(430-3550*) 6.15(3.4-10.1) 12.3(6.8-20.2)
1960(1190-3340 )
470(285-800 ) 5.9 (1.4- 8.5) 11.8(2.8-17.0)
*Single very high water usage responsible for difference
ui
N)
-------
TABLE 17
AVERAGE (RANGE) OF BOD AND FLOW FOR VARIOUS CITRUS PLANT SIZES
PLANT SIZE
320 kkg/day
(350 TPD) or less
FLOW
NUMBER 1/kkg gal/T
PLANTS AVERAGE(RANGE) AVERAGE(RANGE)
BOD
kg/kkg
AVERAGE(RANGE)
Ib/T
AVERAGE(RANGE)
8390(1360-24745) 2010(325-5930) 3.3 (0.7 -8.25) 6.6(1.4-16.5)
Over 320 kkg/day
(350 TPD)
21 10600( 710-24950) 2540(170-5980) 3.2 (0.45-8.5 ) 6.4(0.9-17.0)
Less than 910 kkg/day
(1000 TPD)
8180(1360-24745) 1960(325-5930) 3.0 (0.7 -8.25) 6,0(1.4-16.5)
910 kkg/day-2000 kkg/day
(1000 TPD-2200 TPD)
12 10520(2090-24950) 2520(500-5980) 3.8 (0.7 -8.5 ) 7.6(1.4-17.0)
Over 2000 kkg/day
(2200 TPD)
11100( 710-19070) 2660(170-4570) 2.65(0.45-6.55) 5.3(0.9-13.1)
-------
TABLE 18
AVERAGE (RANGE) OF BOD AND FLOW FOR VARIOUS POTATO PLANT SIZES
FLOW
BOD
PLANT SIZE
NUMBER 1/kkg
PLANTS AVERAGE (RANGE)
gal/1
AVERAGE (RANGE)
kg/kkg Ib/T
AVERAGE (RANGE) AVERAGE (RANGE)
FROZEN POTATO PRODUCTS
360 kkg/day
(400 TPD) or less
Over 360 kkg/day
(400 TPD)
450 kkg/day
(500 TPD) or less
Over 450 kkg/day
(500 TPD)
4 11725 ( 9640-14560)
9 11140( 4090-15520)
6 10600( 4090-14560)
7 11930(10100-15520)
2810(2310-3490)
2670( 980-3720)
2540( 980-3490)
2860(2420-3720)
25.65(11.0 -36.95) 51.3(22.0-73.9)
21.65( 4.45-35.8 ) 43. 3( 8.9-71.6)
20.35( 4.45-36.95) 40. 7( 8.9-73.9)
25.05(12.3 -35.8 ) 50.1(24.6-71.6)
360 kkg/day
(400 TPD) or less
Over 360 kkg/day
(400 TPD)
450 kkg/day
(500 TPD) or less
Over 450 kkg/day
DEH.YDRATED
3 9350( 7450-11810)
4 8350( 6530-12020)
4 10015( 7450-12020)
3 7090( 6530- 7760)
POTATO PRODUCTS
2240(1785-2830)
2000(1565-2880)
2400(1785-2880)
1700 (1565-1860)
8.6 ( 7.75- 9.45) 17.2(15.5-18.9)
12.9 (10.4 -15.2 ) 25.8(20.8-30.4)
10.25( 7.75-15.2 ) 20.5(15.5-30.4)
12.1 (10.4 -15.2 ) 24.2(20.8-30.4)
-------
Climate can affect the performance of apple, citrus or potato waste
water treatment facilities. Biological processes are affected by
temperature. Low temperatures tend to reduce the rate of reduction of
BOD5, and activity may essentially cease where the waste water reaches
freezing temperatures. However, trickling filters and other biological
devices have been successfully operated in freezing weather (Section
VII) , particularly in potato processing (PO-128) .
Climate can also affect the rate of evaporation and the total amount of
net evaporation from ponds. This may affect the size of ponds or drying
fields required for a given loading, but will rarely preclude their use.
Thus, climate does not seriously affect the achievement of a high level
of effluent reduction for apple, citrus, or potato plants.
The availability of inexpensive high quality water is not a problem at
the present time at most apple, citrus, or potato processing plants.
Only one or two isolated cases can be found where plentiful water
supplies are not available, although some processors are located in
areas of expensive water. These processors are usually more careful
about water conservation than processors with plentiful water supplies
who have little incentive to conserve water. Nevertheless, these plants
without plentiful supplies of water are not at a serious economic
disadvantage because of water costs.
In the future, water conservation is expected to be much more important
as a means of reducing the cost of solving waste effluent problems and
saving a natural resource. Thus, it appears that the availability of
water has no serious effects on the achievement of high effluent
reductions in the apple, citrus, or potato industry. In summary,
neither availability of land nor climate nor availability of water
seriously affect the feasability of achieving a high level of effluent
reduction. Accordingly, it is not necessary to further subcategorize
the apple, citrus, or potato industry due to effects from plant
location.
Waste Treatability
Liquid wastes generated in the processing of apples and potatoes contain
principally biodegradable organic matter in soluble and suspended form.
As detailed in Section VII, practicable treatment processes are
available to reduce the BOD contained in these wastes to levels suitable
for discharge. Also, described in Section VII are in-plant control
systems which result in high levels of waste reduction. The
availability of such treatment and control processes makes it
unnecessary to subcategorize based on waste treatability.
The wastes generated by the citrus industry are essentially
biodegradable, but pose special considerations in the design and
operation of the treatment processes discussed in Section VII. Citrus
oil, which occurs in the skin and elsewhere in the fruit is biologically
55
-------
digested only with difficulty. In the operation of standard waste-
treatment processes (e.g., activated sludge), special care must be taken
to maintain a low concentration of oil because of its adverse impact on
microorganisms. Close control of plant operating conditions is required
to avoid filamentous growth and the production of a sludge that is most
difficult to dewater. Despite these difficulties, it has been
demonstrated that such processes as activated sludge, trickling filter,
aerated lagooning, alternating aerobic and anaerobic ponds and spray
irrigation can be expected to treat wastes from apple, citrus or potato
processing plants, and subcategorization on the basis of treatability is
not necessary.
56
-------
SECTION V
WATER USAGE AND WASTE CHARACTERIZATION
WASTE WATER CHARACTERIZATION
Water is extensively used in all phases of the food processing industry.
For example, it is used as one of the following: (1) a cleaning agent
to remove dirt and foreign material, (2) a heat transfer medium for
heating and cooling, (3) a solvent for removal of undesirable
ingredients from the product, (4) a carrier for the incorporation of
additives into the product, and (5) a method of transporting and
handling the product.
Many of the steps used in the process of canning and freezing fruits and
vegetables are common to the industry as a whole, and the character of
the waste waters are similar in that they contain biodegradable organic
matter. Typically, the fruit or vegetable is received, washed and
sorted to prepare it for subsequent processing. Commodities such as
apples, citrus and potatoes are then usually peeled when the end product
style is in a solid form (slices, cubes, or powder). If the final
product is a juice or liquid product, the peel is not removed from
either the citrus or the apples. Subsequent process steps following the
peel removal in which water may be used are trimming, slicing,
blanching, cooling, concentrating and can washing/cooling. Water
transport may be used in one or more parts of the process, and cleanup
is common to all processes.
Although the steps used in processing the various commodities display a
general similarity, there are variations in the equipment used and in
the amount and character of the waste waters produced.
This section presents data relating to cooling and process water usage
and waste characterization for each of the industry subcategories
established in Section IV. The available data from plants in each
subcategory were evaluated to determine current practices in each
commodity as well as each subcategory.
Toward the end of the section, unit process data is compiled in order to
determine plant water usage and waste characterization representative of
a synthesized plant with minimum water usage.
The parameters used to characterize the raw effluent were the flow.
Biochemical Oxygen Demand (BOD), and suspended solids (SS). As
discussed in Section VI, BOD5_ and SS are generally considered to be the
best available measure of the waste load.
57
-------
Water Use and Waste Characterization
Table 19 lists raw waste loadings for BOD and SS from 12 plants
representing the apple processing industry. These twelve plants range
in size from 3,700 to 43,100 kilograms/hour (4.1 to 47.5 tons per hour).
The water usage of these plants varied from 1190 liters per thousand
kilograms (285 gallons per ton) to 14,800 1/kkg (3550 G/T) with an
average flow of 3,660 1/kkg (875 G/T). The plant using 14,800 1/kkg
(3550 G/T) was far removed from the other with the next closest one
using 6,050 1/kkg (1450 gallons per ton). The BOD ranged from 1.4 to
10.1 kilograms per thousand kilograms (2.8 to 20.2 Ibs per ton) and
again the high water user had the highest BOD. The average BOD for the
12 plants was 5.0 kg/kkg (10.0 Ib/ton). Suspended solids ranged from
0.15 to 1.05 kg/kkg (0.3 to 2.1 Ib/ton) with the average being 0.5
kg/kkg (1.0 Ib/ton). Data from plants utilizing processes excluded from
this study (caustic peelers) or plants processing products not included
in this effort (dehydrated apples) are not represented in Table 19.
The average Ibs of BOD per ton for various product styles was discussed
in Section IV (See Table 11). The BOD average ranged from 2.05 kg/kkg
(4.1 Ib/ton) for juice to 6.85 kg/kkg (13.7 Ib/ton) for the sauce and
juice group. The BOD averages for all the groups compared favorably to
the BOD of 5.0 kg/kkg (10.0 Ib/ton) for all apple products with the
exception of the plants producing juice. The flow averages ranged from
1690 to 6,635 1/kkg (405 to 1595 G/T) with the average for all apple
products being 3,660 1/kkg (875 G/T).
58
-------
TABLE 19
LIST OF APPLE INDUSTRY WASTE LOAD
(AP)
CODE
126
ISA
136
140
139
121
114
103
107
141
133
128
CAPACITY
PRODUCT STYLE
SA & SL
SA
JUICE
SL
SA & SL & JUICE
SA
SA & JUICE
SA & JUICE
SA & JUICE
JUICE
JUICE
SA
kg/hr
8.6
5.0
9.1
6.3
31.0
15.9
43.1
21.4
15.9
12.5
4.5
3.7
T/hr
9.
5.
10.
7.
34.
17.
47.
23.
17.
13.
5.
4.
5
5
0
0
2
5
5
6
5
8
0
1
FLOW
1/kkg
1790
2790
1880
14800
3340
1380
1190
2130
1750
3210
3540
6050
gal/T
430
670
450
3550
800
330
285
510
420
770
850
1450
BOD
kjg/kkg
6
3
1
10
7
8
6
5
2
2
5
.05
.4
.6
.1
.5
.5
.25
.8
.0
.55
.0
Ib/T
12.1
6.8
3.2
20.2
15.0
17.0
12.5
11.6
4.0
5.1
10.0
SS
kg/kkg
0.95
0.35
0.35
0.70
-
-
.3
.35
.15
.40
1.05
Ib/T
_
1.9
0.7
0.7
1.4
-
-
0.6
0.7
0.3
0.8
2.1
(All Product Styles)
AVERAGE 14.8
>lo. Samples 12
(APPLE JUICE)
AVERAGE
No. Samples
8.7
3
16.3
12
9.6
3
(APPLE Products Except Juice)
AVERAGE 7.9 8.7
No. Samples 5 5
3660
12
2880
3
5360
5
875
12
690
3
1290
5
5.0
12
2.05
3
6.4
5
10.0
12
4.1
3
12.8
5
0.5
0.3
3
0.8
3
1.0
9
0.6
3
1.6
3
SA - Apple Sauce
SL = Apple Slice
-------
Factors Affecting Waste Water
The condition of the raw fruit has an important bearing on the quality
of the waste water. Fruit condition varies during the processing season
because at the start of the season freshly picked fruit is processed,
while at the end of the season, the fruit has been stored for several
months. The waste water quality can be expected to vary from year to
year as well, in response to yearly changes in fruit quality.
The type of peeling employed has a marked effect on waste water quality.
In particular, caustic peeling produces a higher BOD and SS loading than
mechanical peelers. Variations can also be expected among mechanical
peelers. It should be noted, however, that higher waste water loadings
do not necessarily imply higher fruit loss. Also the waste load
generated by mechanical peeling falls to the floor, or is returned by
the equipment and eventually appears in the cleanup water.
Water usage can, also, be expected to affect waste water quality. Data
indicate that decreased water usage tends to concentrate the organic
materials in the water. This effect is desirable since the reduction in
effluent volume reduces the costs of disposal or treatment.
In Section IV the differences in plant size (See Table 16) and plant
location (See Table 6) were determined to have no significant effect on
waste water character. One of the most important factors affecting
waste water quantity is the attitude of the management and workers.
Where water has been cheap and waste disposal has not been considered to
be an important problem, water usage can be excessive. As an example,
plants AP-134 and AP-128 both produce sauce, but the water usage is
2,790 1/kkg (670 G/T) and 6,050 1/kkg (1,450 G/T) respectively. There
are no readily explainable reasons for the difference.
Water transport adds to water usage, particularly where the water is not
recycled. One type of mechanical peeler requires the apples to be fed
to the peeler by water transport. The use of this type of peeler,
therefore, requires more water than a manual feed peeler.
The majority of plants, especially the smaller ones, currently appear to
be using once-through cooling water in the cooking and cooling step.
They also do not segregate can-wash and can-cooling water. Water
consumption can be reduced by recirculating cooling water.
It has been found that the use of high-pressure pumps for supplying the
cleanup water reduces the amount of water required. Substantial savings
in cleanup water can, also, be achieved by a practice of turning off
hoses when not in use. A plant operator has offered the opinion that
about one half of the clean-up water could be saved, but no quantitative
data are available.
60
-------
Plant age is defined in this report as the average age of the processing
equipment. Process equipment, even in long established companies, tends
to be relatively new or in new condition. Older equipment tends to be
less efficient and, because the industry is competitive, inefficient
equipment is usually replaced.
Citrus
Water Use And Waste Characterization
Waste waters from citrus processing plants contain organic carbon and
matter in suspended and dissolved form. The quantity of fresh water
intake to plants ranges between 710 and 24,950 liters per thousand
kilograms (170 and 5,980 gallons per ton) of raw material. Fresh water
use is highly contingent upon in-plant conservation practices and reuse
techniques and averages approximately 10,110 1/kkg (2425 G/T) of citrus
processed. The nature and amounts of these water reuses as influenced
by in-plant controls and operational practices have a substantial effect
on resulting waste water quantities and characteristics. Reduction in
water use with resulting minimum waste water volumes promises fewer
problems in waste handling and disposal, and greater economy of
treatment.
About two-thirds of the total solids in citrus juices are sugars and the
same may be said of the waste water. Because of this citrus wastes are
highly putrescible. Citrus wastes contain pectic substances which
interfere with settling of the suspended solids. Primary clarification
of citrus waste water is not as effective as with most other wastes.
Citrus waste water contains a small amount of the essential oil that
occurs mostly in the fruit peel. This oil is bacteriostatic but usually
does not interfere with treatment procedures unless it accumulates in an
anaerobic sludge digester. Citrus wastes are deficient in nitrogen and
phosphorus compounds; treatment by biological procedures may be
accelerated by adding these nutrients. Citrus waste water usually is
somewhat acid because of the citric acid it contains. However, alkaline
materials used in cleaning the equipment and lye-bath water from
sectionizing operations tend to make the waste water alkaline, and at
times very strongly so.
The volume of citrus waste water fluctuates through the harvesting
season which usually begins in October and ends in June. The production
of frozen orange concentrate is a continuous operation, running twenty-
four (24) hours per day until it becomes necessary to clean the
equipment. On the other hand, the other processing operations are
mostly a one or two shift operation daily, and may shutdown completely
on weekends or holidays, depending on fruit supply and market demand.
The volume of waste water changes markedly when the production run is
over and clean-up operations begin.
61
-------
The strength of citrus waste water, also, shows considerable variation
depending upon the processing operations that are running at the time.
Cleaning of equipment at the end of the production run will alter the
strength of the waste water significantly. The strength may be
increased at the beginning of clean-up, then lowered as the cleaning
progresses. The pH may change from mildly acid to strongly alkaline
during this time. This is especially true when evaporators are "boiled-
out" or the lye baths of the sectionizing operations are discharged.
The changes in strength, volume, and pH are such that biological
treatment of the waste is rendered difficult unless fluctuations are
leveled out. This is accomplished by a surge tank with suitable mixing
facilities placed ahead of the treatment plant or with treatment plant
design to handle these fluctuations.
Table 20 lists actual raw waste loadings for BOD and SS from 27 plants
representing the citrus processing industry. These plants range in size
from 27 to 5,710 kkg/day (32 to 6300 tons/day). The products include
juice or segments only; juice or segments and oil; juice, oil, and feed;
juice, segments, and feed; juice and segments; and juice, segments, oil
and feed. The water usage ranges from 710 to 24,950 1/kkg (170 to 5980
G/T) . The BOD range from a low of 0.45 to 8.5 kg/kkg (0.9 to 17.0
Ib/ton) with an overall average of 3.2 kg/kkg (6.4 Ib/ton) . The
suspended solids ranged from 0.02 to 7.95 kg/kkg (0.04 to 15.9 Ib/ton)
with an average of 1.3 kg/kkg (2.6 Ib/ton). Plants with both land
treatment systems and secondary treatment systems were used.
In Section IV (See Table 12) , BOD and flow were discussed for various
product styles. The BOD ranged from 0.45 to 8.5 kg/kkg (0.9 to 17.0 Ibs
per ton) for citrus products without segments, citrus products with oil,
and citrus products with feed respectively; their respective BOD
averages were 3.15, 3.2 and 3.25 kg/kkg (6.3, 6.4 and 6.5 Ib/T).
Segments had a BOD of 3.5 kg/kkg (7.0 Ib/ton) which was the highest
average of the group, but only 2 plants were represented. The BOD
averages of the different groups varied from 3.15 to 3.5 kg/kkg (6.3 to
7.0 Ib/ton) which compares very well with the 3.2 kg/kkg (6.4 Ib/ton)
for the 27 plants products all types of products. The water usage<
ranged from 710 to 24,950 1/kkg (170 to 5980 G/T) with the averages
ranging from 7455 to 11,380 1/kkg (1790 to 2730 G/T), which compares to
the 10,110 1/kkg (2425 G/T) for the average of the total 27 plants.
62
-------
TABLE 20
(ci)
CODE PRODUCT STYLE
137
139
101
103
104
105
106
107
108
109
110
111
114
115
116
118
119
122
123
125
126
127
128
129
130
133
143
J
J
J
J
J
J
J
J
J
J
J
J
J
J
J
J
J
J
J
S
J
S
J
J
J
J
J
&
&
&
&
&
&
&
&
&
&
&
&
&
&
&
&
&
&
&
&
&
&
&
&
0
0 &
0 &
0 &
S
0 &
0 &
0
S &
0 &
0 &
0 &
0 &
0 &
S &
S &
0 &
0
0 &
0 &
0 &
S &
S &
0
F
F
F
F
F
0 & F
F
F
F
F
F
F & 0
F
F
F
F
F
0 & F
0
AVERAGE
No.
of
Samples
LIST OF CITRUS
CAPACITY
kkg/day
125
1000
190
320
1130
2270
2090
1090
3410
2860
2860
1840
2450
1840
1225
770
5710
1020
3810
27
5080
225
285
1730
1140
1020
980
1720
27
T/day
140
1100
210
350
1250
2500
2300
1200
3760
3150
3150
2025
2700
2025
1350
850
6300
1125
4200
32
5600
250
315
1910
1260
1125
1080
1900
27
INDUSTRY WASTE
FLOW
1/kkg gal/1
1630
9090
1360
7550
9590
10010
9590
4380
16180
12430
8010
19970
17010
7260
8630
7130
19060
2085
6960
10570
710
4340
24730
19180
4380
24940
6210
10,120
27
390
2180
325
1810
2300
2400
2300
1050
3880
2980
1920
4790
4080
1740
2070
1710
4570
500
1670
2535
170
1040
5930
4600
1050
5980
1490
2425
27
LOAD
BOD
kg/kkg
2
6
8
0
5
2
2
0
5
2
1
8
6
0
3
1
1
6
1
4
0
2
1
3
1
2
2
3
.35
.7
.25
.7
.6
.6
.3
.7
.0
.65
. 3
.5
.55
.95
.15
.45
.6
.4
.6
.35
.45
.65
.35
.2
.4
.3
.75
.2
27
Ib/T
4.
13.
16.
1.
11.
5.
4.
1.
10.
5.
2.
17.
13.
1.
6.
2.
3.
12.
3.
8.
0.
5.
2.
6.
2.
4.
5.
6.
7
4
5
4
2
2
6
4
0
3
6
0
1
9
3
9
2
8
2
7
9
3
7
4
8
6
5
4
27
SS
kg/kkg
0.02
2.7
1.05
0.17
1.55
--
1.55
0.36
1.31
—
0.25
7.95
1.2
—
—
0.65
—
1.25
0.9
—
0.02
0.40
—
—
1.15
—
—
1.3
17
Ib/T
0.
5.
2.
0.
3.
-
3 _
0.
2.
-
0.
15.
2.
-
-
1.
-
2.
1.
-
0.
0.
_
-
2.
-
-
2.
04
4
1
34
1
1
72
62
50
9
4
3
5
8
04
79
3
6
17
J = Juice
S = Segment
0 = Oil
F = Peel Products
P = Pectin
-------
Factors Affecting Waste Water
Table 7 which is discussed in Section IV gives the ratio of grapefruit
to oranges and the resulting raw waste loadings and water usage. Also,
discussed in Section IV is Table 8 that shows the raw product mix at a
single plant for one month. As these tables illustrate there is no
correlation in waste loads when different ratios of grapefruit to
oranges are processed. Plant location (See Table 9) was also determined
to be an insignificant variable. The climate is very similar in the
principal growing areas. Although citrus may be held in storage for
brief periods in California, the fruit is usually processed as received
from the field in Florida. Approximately 90 percent of the citrus grown
in California goes to the fresh market. No significant change in waste
loads could be tied to these differences.
The type of juice extractor used has a pronounced effect on waste water
quality. If the extractor liberates the oil at the time of juice
extraction, and the oil is not collected, but allowed to become part of
the waste effluent, a much more degraded effluent will result.
The quantity of waste water from the oil/peel products process is small
but contains a high concentration of contaminants. This material can be
satisfactorily disposed of by spray irrigation when mixed with other
effluent steams but is difficult to treat in activated sludge or similar
biological systems. This material can, also, be added directly to the
peel before it is dried or sent to the molasses evaporators. As shown
in Table 14, availability of a waste heat evaporator does not
significantly affect the raw waste loading.
Plant age is defined in this report as the average age of the processing
equipment. Processing equipment, even in long established companies,
tends to be relatively new or in new condition. Older equipment tends
to be less efficient, and because the industry is competitive,
inefficient equipment is usually replaced. In all plants visited, the
processing equipment was determined to be relatively new on the basis of
visual inspection. As a result of this, no difference can be attributed
to effluent quantity or quality due to plant "age."
Perhaps the most important factor affecting waste water quantity is the
attitude of the management and workers. Where water has been cheap and
waste disposal has not been considered to be an important problem, water
usage can be excessive. Water transport also adds to water usage. In
many cases this water can be recycled. Barometric condensing and
cooling waters, which are relatively clean, can be recycled if a cooling
tower or large pond were included in the circuit. This could reduce
water usage by 30 to 70 percent depending on the plant.
Neither waste water quality or quanity are influenced by plant size.
Small plants (less than 910 kkg (1,000 tons) of raw material processed
64
-------
per day) produced essentially the same quality and quantity of waste
water as large plants. (See Table 17) .
Potatoes
Water Use and Water Characterization
Table 21 gives the raw loadings for BOD and SS from 23 plants
representing the frozen and dehydrated potato processing industry.
These 23 plants range in size from 180 to 1630 kkg (200 to 1800 tons)
per day. The BOD ranged from 4.45 to 36.95 kg/kkg (8.9 to 73.9 lb/ton)
with an average of 18.1 kg/kkg (36.2 lb/ton). Suspended solids ranged
from 3.8 to 45.5 kg/kkg (7.6 to 91.0 lb/ton) with an average of 15.9
kg/kkg (31.8 lb/ton). Water usage ranged from 4090 to 15,510 1/kkg (980
to 3720 G/T) with an average of 10,270 1/kkg (2460 G/T).
Table 13 lists the BOD and flows for various potato product styles.
Frozen products with data from 13 plants had an average BOD of 22.9
kg/kkg (45.8 lb/ton) with a range of 4.45 to 36.95 kg/kkg (8.9 to 73.9
lb/ton) and an average flow of 11,320 1/kkg (2710 G/T) . Dehydrated
products with data from 7 plants had an average BOD of 11.05 kg/kkg
(22.1 lb/ton) with a range of 7.75 to 15.2 kg/kkg (15.5 to 30.4 lb/ton).
The average flow was 8770 1/kkg (2100 G/T) . Three plants producing both
frozen and dehydrated products had a average BOD of 13.8 kg/kkg (27.7
lb/ton) and an average flow of 9260 1/kkg (2220 G/T) .
Factors Affecting Waste Water
The quality of the waste water is affected by the condition of the raw
product. Sometimes early in the processing season, the waste loading
will go up due to freezing in the fields. Potatoes shrink or lose
weight during storage. This weight loss is composed of water loss from
the tubers, carbon dioxide loss and decay losses as a result of rotting.
The amount of these losses are determined by storage conditions, such
as: (1) temperature, humidity, evaporating power of the air,
composition and movement of the air; and (2) maturity and condition of
the potatoes at the time of storage. Usually the longer the potatoes
are stored,the higher will be the waste loading and many plants show a
marked increase in waste loading toward the end of the processing
season.
In Section IV, the differences in size and location of potato processing
plants (See Tables 10 and 18) were determined to have no significant
effect on waste water character. One of the important factors affecting
waste water quantity is the attitude of the management and workers.
65
-------
Where water has been cheap and waste disposal has not been considered to
be an important problem, water usage can be excessive.
Effluent Analyses By Unit Process
The following raw waste characteristics have been tabulated from the
best available in-plant unit process waste characteristics. Total raw
waste effluent values can be calculated, but caution must accompany such
a tabulation. The tabulations should not be used to develop effluent
limitation guidelines. The waste characteristics of primary concern are
BOD5 (five-day biochemical oxygen demand) and SS (suspended solids).
The following tabulations summarize BOD5, SS and water usage values by
process steps for apples, citrus, and potatoes. They have been
synthesized from available data acquired through in-plant sampling with
some supplemental in-plant data acquired from processors. In only a few
cases was complete in-plant data available. Information from 10 apple
plants, 20 citrus plants, and 15 potato plants was used to develop these
tabulations. The tabulations are not used to develop effluent
guidelines. The purpose of this presentation is to show where
substantial water savings can be realized and where substantital waste
reductions can be accomplished. They should not be used to develop
effluent limitations.
Washing, as listed in Table 22, includes receiving and sorting as well
as fruit cleaning. The apples are dumped into a water filled tank and
are washed with water sprays after leaving the tank or the associated
water transport system. Mechanical peeling, slicing and deaeration are
treated as separate process steps. Cooking and cooling waters can be
kept separate and are shown as individual values. Cleanup (floor and
equipment) normally occurs in a separate work shift, following one or
two processing shifts.
Although it is not yet general practice in the industry, some plants
recycle the water used for can cooling through a cooling tower or spray
pond. When recycling, the small amount of spray water used to clean the *
cans following cooking is kept separate from the cooling water in order
to keep organic material out of the cooling water. In this and
subsequent tabulations, the can wash water is included in the water used
for cooking. We estimate that the cooling water requirements can be
reduced to about 5 percent of the once- through requirement of 1,182
1/kkg (283 G/T) or to a level of 58 1/kkg (14 G/T) as used in Table 22.
The latter figure is used for the cooling step in apple processing.
Seven of ten plants contributing data listed in Table 22 are primarily
sampled plants processing stored fruit near the end of the canning
season. The ten plants make different apple products and product mixes
and range in size from less than 3.6 kkg/hr (U T/hr) to more than 28
kkg/hr (31 T/hr). As shown on the accompanying water flow diagrams
Figures 4-6, the production of each product style (sauce, slices and
66
-------
juice) employs a different set of operations. Water usage and
characterization can be determined for the production of slices, sauce
and juice. Water usage for the three product styles (sauce, slices and
juice) are presented in Figures 4-6. The process steps employed in the
manufacture of sauce are washing, peeling, slicing, cooking, cooling,
transport and cleanup. The process steps for slices are washing,
peeling, slicing, deaerating, cooking, cooling, transport and cleanup.
The production of juice involves only washing (including receiving and
sorting), transport, cooling and cleanup. Data from about 20 citrus
plants processing different citrus products and co-products contributed
to the tabulation given in Table 23. Fruit cleaning, as used in Table
23, includes washing, as well as receiving and sorting. The citrus is
sometimes stored in bins and upon leaving the bins if washed with water
sprays and/or roller brushes with sprays and sometimes detergent. Juice
extraction may be accomplished by slicing the citrus in half and reaming
each half simultaneously. After extraction, the peel and the majority
of the pulp are separated from the juice and may, or may not, be
processed for citrus oil and other by-products. Depending on the
extractor, oil may or may not be liberated from the peel at this point.
The juice is next passed through a finisher and may then be either
processed into single strength (S.S.), which involves juice
pasteurization/homogenization and can cooling, or concentrated which
involves evaporation of the juice. The majority of the cleanup normally
occurs in a separate work shift, following one, two, or two and one-half
processing shifts.
Oil/peel-pulp by-products are manufactured from plants that have some
type of juice operation. Additional water flows involved include the
waste heat evaporator condensate, the waste heat evaporator's barometric
condensate, the waste heat evaporator's scrubber effluent, and the oil
lean residue from the d-limonene residue separator.
The production of segments involves waste water from peeling, caustic
treating, washing, cooking, cooling and cleanup.
By referring to Figure 7, it is possible to develop water usage figures
for plants making various product combinations. Water use figures for
juice and oil processing, segment processing and juice, oil and peel
product processing can be determined. The figures are the summation of
the water flows from each of the process stops required to produce
juice, oil, segments and peel products with minimum water usage.
There is a degree of variability for water usage and waste
characterization among the products and product combinations. The
majority of this variability is attributable to differences in plant
operation and plant management and difference in availability of raw
material, water, and waste treatment facilities. Minor differences in
size, age and location of plants also contribute to the total
variability. Even without consideration of these sources of
variability, there is sufficient similarity for water usage and waste
67
-------
character among the product combinations to support a single category
for the citrus industry.
Fifteen potato plants processing frozen and/or dehydrated potato
products contributed to the waste characterization given in Table 24.
In each of these potato processing subcategories, there are several
processing steps using large quantities of water which are common to
both categories.
For example, it is common practice to use water hoses to remove the
potatoes from storage and direct them into a water transport system for
delivery to the process area. In an exemplary water usage plant, the
water which is used to receive and clean the potatoes is usually
segregated from the process water. The receiving/cleaning water is
recycled through a settling basin where there is sufficient retention
time to allow the solids to settle out in the basin. The make up water
to this closed system is added by water sprays which are positioned to
rinse the potatoes as they enter the process.
Three methods of peeling are in current industrial use within the frozen
and dehydrated potato processing industry: dry caustic, conventional wet
caustic and steam. With the conventional wet caustic and steam peeling
systems, large quantities of water were used for removal of the treated
peel. This results in large waste loads appearing in the plant waste
effluent discharge as can be seen in Table 24.
During the slicing step, large quantities of water are used to remove
any starch adhering to the surface of the pieces. This water is also
used to convey the pieces to the blanching step.
Water blanching is required for both frozen and dehydrated products
since a large amount of the leachables must be removed from the potato
pieces during the blanching step. In the case of frozen products, a
three step series blanching system is used. While for dehydrated
products the water blanching step is followed by a water cooling step
and then a cooking step.
The frozen products are usually french fried while the majority of the
dehydrated products are dried in a flake or granule form.
As shown on the accompanying water flow diagrams (Figures 8-9), the
production of dehydrated and frozen products employs different process
steps. Water usage and waste characterization can be determined for the
production of both products. As mentioned earlier, the tabulations
should not be used to develop waste water effluent limitation
guidelines. The tabulations are presented only to show where
substantial water savings can be realized and where substantial waste
reductions can be accomplished.
68
-------
TABLE 21
LIST OF POTATO INDUSTRY WASTE LOADINGS
(PO)
CAPACITY
CODE PRODUCT STYLE kkg/day T/day
131
132
110
116
125
130
101
102
103
108
109
111
112.
115
136
107
113
122
127
128
123
129
114
F
F & D
F
F
F
F
F & D
F
F
F
F
F
F
D
D
D
D.
D
F
F & D
D
F
D
360
430
320
450
340
540
1630
540
630
1040
725
910
220
590
540
500
340
450
135
230
180
450
400
475
350
500
375
600
1800
600
700
1150
800
1000
240
650
600
550
375
500
150
250
200
500
FLOW
1/kkg
11800
8590
14560
12510
10880
10430
12800
15510
10090
10340
13430
11260
12510
8760
7760
7010
6530
11800
4090
6380
7460
9630
12010
gal/T
2830-
2060
3490'
3000
2610
2500
3070
3720
2420
2480-
3220
2700
3000
-2100
-I860
- 1680
-1565
-2830
980-"
1530
-1790
2310
- 2880
BOD
k&/kkg
25
13
36
15
29
35
13
31
25
32
20
16
12
8
10
10
15
9
4
13
7
11
15
.4
.9
.95
.1
.25
.8
.95
.95
.45
.25
.75
.9
.3
.6
.4
.75
.2
.45
.45
.75
.75
.0
.2
Ib/T
50.8'
27.8
73.9-
30. 2'
58.5
71.6
27.9
63.9'
50.9-
64.5-
41.5-
33.8-
24.6-
•17.2
•20.8
21.5
30.4
18.9
8.9'
27.5
15.5
22.0-
30.4
SS
kg/kk^
6
11
8
22
27
11
45
12
29
23
12
9
5
11
3
12
.55
.75
—
.9
.1
.8
.2
.5
.6
.3
.85
—
--
—
.15
.8
—
--
.1
.8
.8
.5
--
Ib/T
13.1
23.5
—
17 .8
44.2
55.6
22.4
91.0
25.2
58.6
47.7
—
--
—
24.3
19.6
—
__
10.3'
23.6
7.6
25.0-
--
(All Product Styles)
AVERAGE 550 610
No. Samples 23 23
i
(FROZEN PRODUCTS)
AVERAGE 625 690
"lo. Samples 13 13
' (DEHYDRATED PRODUCTS)
AVERAGE 410 450
"Jo. Samples 7 7
10270 2460
23 23
11300 2710
13 13
8760 2100
7 7
18.1 36.2 15.9 31.8
23 23 16 16
22.9 45.8 19.4 38.8
13 13 10 10
11.05 22.1 8.6 17.2
773 3
F = FROZEN PRODUCTS
n = DEHYDRATED PRODUCTS
69
-------
TABLE 22
APPLES
Water Usage and Waste Characterization in Apple Processing
Water Usage
BOD5
Process Step
Washing
Peeling
Mechanical
Slicing
Deaeration
Cooking
Cooling (1)
Transport
Clean-up
1/kkg
142
104
638
71
267
58
58
1,558
G/T
34
25
158
17
64
14
14
372
kg/kkg
0.09
0.16
2.49
2.21
0.14
0.02
0.02
1.90
Ib/T
0.18
0.31
4.97
4.42
0.27
0.03
0.03
3.80
Suspended Solids
kg/kkg Ib/T
0.03
0.015
0.182
0.12
0.05
0.005
0.005
0.30
.06
0.03
0.36
0.24
0.10
0.01
0.01
0.60
(1) 95% recirculated
-------
APPLES
SCREENING-
T T
WASTE EFFLUENT SOLIDS
TO TO
TREATMENT OR DISPOSAL WASTE
'lx WASH WATER - DUMPED
;' EVERY 8 HRS
'''2> PEEL & CORE REMOVAL
V INCLUDING TRANSPORT
<3^ SLICING INCLUDING
;. SLICE WASHING
<4> DEAERATING
'o> CLEAK-UP V-ATER
TOTAL WATER
RECEI
•-WAS:-
*
V
'
VING x\
ING •*/ ly
r
kkg GPT
142 34
104 25
638 153
71 17
1552 • 372
PEELING
CORING -
-f» SLICING -
I
I
.DEAERATING
i
-?- 3
2507
601
PACKAGING
FREEZING
TO CONSUMER
FIGURE 4
WATER FLOW DIAGRAM - APPLE SLICES (FROZEN)
-------
SCREENING'
APPLES
WASTE EFFLUENT SOLIDS
TO TO
TREATMENT OR DISPOSAL WASTE
RECEIVING
e> WASHING —
WASh WATER
PEEL & CORE REMOVAL, &
SLICING INCLUDING TRANSPORT
COCKING
CAN COOLING RECIRCULATED
TO COOLING TOWER
CIE.-.N-UP WATER
801
267
58
1552
GPT
34
192*
64
14
372
PEELING
>- CORING
/\
->/2
FILLING
-*- COOKING •
TOTAL WATER
2821
676**
-COOLING.
I
TO CONSUMER
Caustic Peeling 1127 1/kkg (270 Gal/Ton)
V;ATER FLOW DIAGRAM - APPLE .SAUCE
-------
SCREENING-
APPLES
WASTE EFFLUENT SOLIDS
TO TO
TREATMENT OR DISPOSAL WASTE
RECEIVING
- WASHING -
GRINDING
I
PRESSING
WASH WATER
INCLUDING TRANSPORT
2} CLEAN-UP
1/kkg GPT
200 48
1,552 372
FILTERING
FINISHING
TOTAL WATER 1,752 420
PASTEURIZING
I
FILLING
|
TO CONSUMER
FIGURE 6
WATER FLOW DIAGRAM - APPLE Juice
-------
TABLE 23
CITRUS
Water Usage and Waste Characterization In Citrus Processing
Water Usage BODS Suspended Solids
Process Steps 1/kkg (G/T) kg/kkg (Ib/T) kg/kkg (Ib/T)
Fruit Cleaning 303 ( 73) 0.08 (0.16) 0.04 (0.07)
Extracting 389 ( 93) 0.40 (0.79) 0.27 (0.54)
Pasteurizing/Homogenizing 62 (15) 0(0) 0 ( 0)
Cooling (1)
Juice Products 221 ( 53) 0.03 (0.05) 0.02 (0.03)
Segments 0.01 (0.02) 0.01 (0.02)
Juice Condensing 400 ( 96) 0.06 (0.12) 0.02 (0.03)
Barometric Condensing (2)
Juice Products 50 ( 12) 0.07 (0.13) 0.09 (0.17)
Waste Heat Evaporator 71 ( 17) 0.15 (0.29) 0.09 (0.18)
Peeled Fruit Washing 129 ( 31) 0.04 (0.07) 0.01 (0.01)
Caustic Treatment 1 (0.3) 0.01 (0.02) 0.01 (0.01)
Centrifuging 144 ( 35) 3.07 (6.14) 0.51 (1.02)
Container Washing 75 ( 18) 0 0(0)
Waste Heat Evaporator
Condensate 334 ( 80) 0.33 (0.66) 0.11 (0.22)
Waste Heat Evaporator
Scrubber Effl. 351 ( 84) 0.22 (0.43) 0.08 (0.15)
Oil Lean Residue From
Separator 126 ( 30) 0.16 (0.32) 0.25 (0.49)
Boiler Slowdown 60 ( 14) 0.01 (0.02) 0.01 (0.02)
Regeneration Brine 13 (3) 0(0) 0 (0)
Cleanup
Juice Products 705 (169) 0.16 (0.32) 0.16 (0.31)
Segments 371 ( 89) 0.36 (0.72) 0.07 (0.13)
Peel Products 484 (116) 0.07 (0.14) 0.11 (0.22)
(1) 90% recirculated
(2) 2% cooling tower blowdown
-------
CITRUS
RECEIVING/SORTING
fc-FRUIT CLEANING
i
»t. yy
-*<$>
EXTRACTING-
t l~-
WATER-OIL EMULSION —
FINIShlNG-
j
-PEEL-
~l
CONCENTRATED JUICE i SINGLE STRENGTH
J
JUICE CONDENSATE
CONDENSER
— —1 FINISHING—SLUDG:
ICENTRIFUGIKG
COLD PRESSED
.'DGE-»-l
PEhLIMG
CAUSTIC •: .••i.AT.Xhl."
TOSOLIljS FROM
WASTE TREATMENT S
SCREENING
••CONTAINER WASHING-
I
PACKAGING
—^CONTAINER WASHING
» COOLING
J >i \_UJ-"-' rtvc»o3ijU
JRIZING—»«Q3\ OIL
.PASTEURIZING
1
I
i 'J U'J.« -r-'ji'lr-K
rO COWSUI'-ER-
CLEANING
TRACT1NG CLEANUP
COSAKOiTSIC CONDENSER
<^>CON7AINER WASHING
• CAUSTIC TREATKENT/WASHIKG
<1^> COOLING
REGENERATION BRINE
<.'ii> CLiA:;UP (JUICE PRODUCTS)
WASTE HSAT EVAPORATOR
SCR'-'53ER tPFLULKT
> "nASTE iiEAT EVAPORATOR CONCENSATE 334
>V:AETE HEAT EVAPORATOR
BARPKETRIC CCNTENSER
1/k.kg
305
38B
401
50
75
63
221
130
63
13
705
371
351
334
71
125
G/T
73
93
96
12
18
15
53
31
15
3
169
89
84
80
17
30
-.
-- j
SCRUBBER
WATER — WASTL ht/iT
J
OIL
WASTE EFFLLEi.'T TI'.iiAT:-U;:;T
TKLA1.ILi-"i fJt*
>iij> WATER, OIL SLT.M^VTi^N'
^. C^T.v.^P (PE-^ PRODUCTS)
TC7AL V.'ATER 4,150 1/kkg 994 G/T
FIGURE 7 V;ATER FLOW DIAGRAMS - JUICE,OIL,SEGMENTS, AND PEEL PRODUCTS
-------
TABLE 24
POTATOES
Water Usage and Waste Characterization In Potato Processing
Water Usage BOD5 Suspended Solids
Process Steps 1/kkg G/T kg/kkg Ib/T kg/kkg Ib/T
Washing 1,102 264 0.676 1.35 1.383 2.76
Peeling
Dry Caustic 1,448 347 7.325 14.62 9.569 19.1
Wet Caustic 3,000 719 20.245 40.41 28.662 57.2
Steam 2,391 573 15.215 30.37 13.427 26.8
Trimming 793 190 0.777 1.55 0.26 0.52
Slicing
Dehydrated 764 183 0.296 0.59 0.701 1.4
Frozen 1,519 364 2.630 5.25 1.303 2.6
Blanching
Dehydrated 175 42 0.701 1.40 0.601 1.2
Frozen 1,043 250 5.461 10.9 2.104 4.2
Cooling 668 160 1.172 2.34
Cooking 448 117 1.192 2.38
Dewatering 513 123 0.471 0.94 0.351 0.70
Fryer Scrubber 417 100 - - -
Fryer Belt Spray 417 100 - - - -
Refrigeration 1,602 384 -
Transport Water 292 70 0.261 0.52
Cleanup 951 228 2.725 5.44
-------
POTATOES
SWASH WATER
PEELING
>J (DRY CAUSTIC)
<3> TRIMMING
<$> SLICING
& BLANCHING
<©> COOLING
COOKING
<8> TRANSPORT WATER
CLEAN-UP
TOTAL (Not
Including Washing)
TOTAL '
1/kkg
1,102
1,448
793
764
175
668
448
292
951
5,579
RECEIVING >\
PEELING
—— . . r*» fnT?V PATTr>LTTP^ ,,...,. c-rw
t
I
_— __ .,,.. j^TIUMMIIJC ' " C**(
i
GPT |
264 1
.1
183
42
160
117
70
228
1,337
SCREENING•
WASTE EFFLUENT SOLIDS
TO TO
TREATMENT OR DISPOSAL WASTE
.(Including Washing) 6 , 681 1,601
-s^ COOLING
I
I
•COOKING
i
I
MASKING
FLAKING
I
PACKAGING
TO CONSUMER
WATER FLOW DIAGRAM - DEHYDRATED POTATO FLAKES
-------
POTATOES
RECEIVING
> WASHING • •• •
1
CAUSTIC)
3ER
= RAYS
\~ WATER
IER
/^
1/kkg
1,102
1,448
793
1,519
1,043
•513
417
417
1,602
292
951
WAST
TRSATME
i
'"-PEELING CAUSTIC f-' 2
i
>~ TRIMMING i.-/ 3\
^- SLICING _/4\
. /
*_ BLANCH ING t- 5\
F-DEWATERING s~x6\
>•
GPT I
?r>4 *
247
190 FRY
364
250 »-FRYE
123
100 " '
100
384
70
228
EFFLUENT
TO
SOLIDS
TO
'CASTE
<1>WASH WATER
<2>PEELING CD!
<-3/TRII-LMING
(4;SLICING
<5VBLANCHING
<(6>DEWATERING
<,,7.>FRYING SCRUBBER
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SECTION VI
SEIECTION OF POLLUTANT PARAMETERS
WA ST E_WATER_PARAMETERS OF MAJOR SIGNIFCANCE
A thorough analysis of the literature, industry data and sampling data
obtained from this study, and EPA Permit data demonstrates that the
following waste water parameters are of major pollutional significance
for the apple, citrus and potato processing segment of the canned and
preserved fruits and vegetables industry:
Biochemical Oxygen Demand (5-day, 20° C., BOD5)
Suspended Solids (SS)
PH
Rationale^for_Selection of Major Parameters
Biochemical Oxygen Demand
This parameter is an important measure of the oxygen utilized by
microorganisms in the aerobic decomposition of the wastes at 20°C over a
five day period. More simply, it is an indirect measure of the
biodegradability of the organic pollutants in the waste. BQD5 can be
related to the depletion of oxygen in a receiving stream or to the
requirements for waste treatment.
If the BOD5 level of the final effluent of a processing plant into a
receiving body is too high, it will reduce the dissolved oxygen level in
that stream to below a level that will sustain most fish life; i.e.
below about U mg/1. Many states currently restrict the BOD15 of
effluents to below 20 mg/1 if the stream is small in comparison with the
flow of the effluent. A limitation of 200 to 300 mg/1 of BOD5 is often
applied for discharge to municipal sewer, and surcharge rates often
apply if the BOD.5 is above the designated limit.
Suspended Solids
This parameter measures the suspended material that can be removed from
the waste waters by laboratory filtration, but does not include coarse
or floating matter than can be screened or settled out readily.
Suspended solids are a visual and easily determined measure of pollution
and also a measure of the material that may settle in tranquil or slow
moving streams. A high level of suspended solids is an indication of
high organic pollution.
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pH
pH is an important parameter for providing in-process quality control
for recycling of process water. Biological treatment systems operate
effectively at a pH range between 6.0 and 9.0. These systems can be
rendered ineffective by intermittent dumping of highly acidic or highly
alkaline wastes such as caustic tanks used for peeling.
for Selection of Minor Parameters
Chemical Oxygen Demand (COD)
COD is another measure of oxygen demand. It measures the amount of
organic and some inorganic pollutants under a carefully controlled
direct chemical oxidation by a d ic hr ornate- su If uric acid reagent. COD is
a much more rapid measure of oxygen demand than BODj> and is potentially
very useful.
COD provides a rapid determination of the waste strength. Its
measurement will indicate a serious plant or treatment malfunction long
before the BOD5 can be run. A given plant or waste treatment system
usually has a relatively narrow range of COD:BOD5. ratios, if the waste
characteristics are fairly constant, so experience permits a judgment to
be made concerning plant operation from COD values. In the industry,
COD ranges from about 1.6 to 10 times the BODjj; the ratio may be to the
low end of the range for raw wastes, and near the high end following
secondary treatment when the readily degraded material has been reduced
to very low levels.
In summary, BOD and COD measure organic matter which exerts an oxygen
demand. Both COD and BOD are useful analytical tools for the processor.
However, no COD effluent limitations are required because BOD
limitations have been established.
Total Dissolved Solids (TDS)
The dissolved solids in waste water are mainly inorganic salts. They
are particularly important as they are relatively unaffected by
biological treatment processes and can accumulate in water recirculation
systems. Failure to remove them may lead to an increase in the total
solids level of ground waters and surface water sources. The dissolved
solids in discharge water, if not controlled, may be harmful to
vegetation and may also preclude various irrigation processes. There is
not sufficient data available to establish effluent limitations for TDS,
but at land treatment systems TDS must be managed to insure satisfactory
performance without damage to the physical properties of the soil or to
the quality of the ground waters.
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Alkalinity
The measure of alkalinity is an indicator of bicarbonate, carbonate and
hydroxide present in the waste water. The alkalinity of water appears
to have little sanitary significance. Highly alkaline waters are
unpalatable, and may adversely affect the operation of water treatment
systems. However, pH limitations require the control of alkalinity,
thus, no alkalinity limitations are needed.
Ammonia Nitrogen and Other Nitrogen Forms
Neither apple, citrus or potato effluents contain significant quantities
of nitrogen. The three most common forms of nitrogen in wastes are
organic, ammonia and nitrate. Organic nitrogen will break down into
ammonia, nitrogen and nitrate. When ammonia nitrogen is present in
effluent waste water, it may be converted to nitrate nitrogen by
oxidation. When ammonia and nitrates are added to ponds and lakes, they
contribute to euthrophication. Since fruit and vegetable wastes are
generally deficient in nitrogen, no nitrogen limitations are required.
Total Phosphorus
Phosphorus, like nitrate, is linked directly to the eutrophication
process of lakes and streams. Sampling shows no significant levels of
phosphorus in apple, citrus or potato waste water. When applied to
soil, phosphorus does not exhibit a runoff potential because it is
readily absorbed tenaciously on soil particles. In this case, movement
of phosphorus to ground water is essentially precluded and runoff can
only occur if actual erosion of the soil takes place. Since fruit and
vegetable waste waters are generally deficient in phosphorus, no
phosphorus limitations are needed.
Fecal Coliforms
Significant numbers of fecal coliforms are generally not found in apple,
citrus or potato waste waters unless sanitary waste is mixed with
process waste. In order to insure that the bacteriological quality of
waste waters does not create a problem all sanitary wastes should be
handled separately from process waste waters. Because coliforms are not
a major constituent of the raw waste water and because in-plant reuse of
water, waste water retention and land disposal minimize bacteriological
problems, fecal coliform effluent limitations are not required.
Temperature
The temperature of effluent waste water is important, since release of
water at elevated temperatures into surface or ground water formations
could result in damage to the micro-ecosystems. The design of treatment
facilities is also dependent upon the plant effluent temperature.
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However, high temperature wastes are not associated with apple, citrus,
or potato processing. Thus, guidelines for temperature are not needed.
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SECTION VII
CONTROL AND TREATMENT TECHNOLOGY
INTRODUCTION
The characterization of the waste effluents has provided a specific
description of the waste streams resulting from the food processes,
involving identification of the origin of the various waste streams in
the process, as well as waste water quality and quantity. This permits
identification of the process steps which are the major contributors to
the flow and waste loadings of the total waste effluent stream.
Comparisons can be made between similar or alternative operations in
other processing facilities that perform the same function but produce
differing amounts of waste. The data provide information for
consideration of in-plant separation of the most significant waste
streams for separate treatment within the processing plant and also
provide valuable insight into the properties of the wastes present and
indication of their treatability.
IN-PLANT TECHNOLOGY
Waste characterization studies cannot be adequately discussed without a
basic conception of the sources of wastes generated in apple, citrus and
potato processing. A discussion of the eight basic sources of wastes
are presented herein. It must be realized, that there are many process
variations within production operations and all eight waste sources may
or may not be present. However, when required by production operations
each process is present regardless of size, age, or location of plant.
Harvesting
This operation can be defined as removal of the product from its growing
environment, its collection and its transportation to the processing
plant. The present systems of picking include combinations of human
effort and machine utilization with a gradual, but steady, increase in
the latter. The increased use of mechanical means of picking has
increased the amounts of soil and organic solids included with the
product, and has resulted in a higher organic load from damaged or
spoiled raw products. This trend has also increased the amounts of
water necessary for washing and cleaning the product. Current studies
have suggested the possibility of relieving the waste load at fruit and
vegetable processing plants by field washing techniques. The use of
economically feasible and aesthetically acceptable procedures for
sorting, cleaning and sanitizing these crops in the field has many
potential advantages. Rejected raw product, plant materials, field
soil, and wash waters remain in the field, waste disposal there can be
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by methods both simpler and less costly than the methods available for
waste materials hauled into urban communities.
This technique is only suitable for the raw material which needs to be
processed right after harvesting. For example, the tomato industry has
applied this technique very successfully. But as far as the three
discussed commodities, only citrus has the possibility to adapt this
method. Apples and potatoes both are usually placed into storage after
harvesting for processing later in the season; and storage of wetted raw
crops will increase the possibility of spoilage. The technique, if
applied to citrus, would reduce water and waste loadings only a small
amount. Therefore it is not practical to apply field washing techniques
for these commodities.
Raw Material Cleaning
After harvesting, the raw material (such as apples or potatoes) either
is placed into storage or goes directly to the processing plant. Fruit
is often given a preliminary washing to remove soil and organic
materials before preparing for processing. A common method is to drop
the product directly into water which acts as a cushion for unloading
the fruit. The raw material is separated from much of the remaining
leafy and stem material, soil residues, seeds, and pesticide residues.
After this initial wash, the raw material cleaning operations contribute
minor pollutants to the waste water.
Apples and potatoes are stored for processing later in the season. If
the storage house is located in a different area from the processing
plant, the raw material could be washed as it is withdrawn from storage
and sorted for the fresh market. This way, the waste load at the
processing plant could te reduced.
In the case of potatoes, the increased mechanization of harvesting has
increased the quantity of soil or dirt pickup at harvest. These
increased soil loads can require more thorough water washing or
alternate cleaning systems. Therefore, if the washing is done at a
storage site removed from the processing plant, it could save
approximately 8 percent of the total water usage at the processing plant
and eliminate the need or at least reduce the size of the silt pond.
Peel Removal
In the case of the fruits, apple and citrus, where it is necessary to
remove the peel, the conventional system employs a mechanical means of
peel removal.
In citrus processing, the manufacture of segments involves a hot lye
treatment to remove the rag and membrane from the whole peeled fruit
prior to sectionizing. This hot alkaline treatment, also, results in an
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excessive waste effluent load. Less than 15 percent of the total citrus
harvest is sectionized and receives a caustic treatment.
The peeling of potatoes generates higher waste loads than those which
are produced by either the apple or citrus peeling operations. In the
potato processing industry, excluding potato chip manufacture, there are
two generally accepted methods of peel treatment, caustic and steam. In
the case of the caustic, either a hot dip or hot spray contact can be
used. In the dry caustic system, the alkaline solution is baked into
the skin of the potato prior to peel removal.
Water sprays or rubber abrading (USDA development) are the two principal
means of removing the loosened peel following treatment. If the peel is
removed by water sprays, then the waste effluent load in the water
system is increased; however, if the loosened peel is removed by rubber
abrading and brushing with added water, the peel is collected as a
slurry and may be disposed of as animal feed. Different treatment and
peel removal operations do not significantly affect the waste effluent
load based on data from Section IV. However, information from vendors
and other sources indicates that peeling represents 20 percent of the
effluent flow, over 50 percent of the BOD and over 60 percent of the SS.
In addition, when the USDA scrubbers are utilized, peel wastes are only
half as great.
Almost all frozen potato products, french fries, hash browns, etc., are
caustic treated prior to peeling. The caustic system (either wet or
dry) is used because of the thorough peeling required for these
products. Dehydrated potato products are peeled with either the caustic
or steam peel system.
Sorting, Trimming & Slicing
Sorting and grading operations may take place at various points in the
process prior to packaging and may occur more than once in the same
process. The primary purpose of these operations is to remove those
pieces with undesirable blemishes or grade or sort for size and shape.
Separations as to quality of the product are most often done by hand,
while size separations are done by mechanical means. Wastes from these
operations consist of whole pieces, miscellaneous organics and juice.
Trimming operations are defined as the removal of unwanted portions of
the product. These wasted portions consist of blemishes, cores, pits,
and peels. Blemish removal is done by hand and results in waste
products consisting of pieces and juice. Cores and pits are most often
removed mechanically.
In the processing of apples, the water exposed to the interior of the
fruit, apple slices or dices, as they are cut, washed, or transported,
can be recirculated for a given period of operation, thus allowing the
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soluble and suspended solids to build up in the water system. When it
is necessary to replace this water because of product quality, the
contaminated water can be further concentrated by evaporation and then
used as a vinegar stock. Of course, the above system really only
applies to the manufacture of apple slices. In the manufacture of
sauce, the apple pieces are cut and dropped directly into the cooker,
thus, as in the manufacture of cider, little BOD5 is generated.
In the sorting or trimming process, only in the citrus sectionizing
process does the interior of the fruit contact the water used for
fluming.
In the processing of the potato, the cutting (slicing) of the potato
frees quantities of starch which is washed from the potato pieces into
the wash or slicing water. If this water is maintained at ambient
temperatures and recirculated within the system, it is possible to
remove with cyclones a concentrated stream of crude starch as it is
built up in the recirculated water. This starch slurry can be sold to
potato starch processors as a starting raw material. This system
(removal of starch from slicing and washing water) is currently being
employed on a small scale by several potato processors.
Transport
Various means have been adopted for conveying fruit or vegetable
products at unloading docks into and through the process plant. These
include fluming, elevating, vibrating, screw conveyor, air propulsion,
negative air, hydraulic flows and jet or air blast. Among them, flume,
belt, and pump transport systems are the most common means. Water, in
one way or another, has been extensively used in conveying products
within plants because it has been economical and because it serves not
only as conveyance but, also, for washing and cooling. It is also
assumed that there was some sanitary significance for both product and
equipment. Therefore, flume transport requires much greater quantities
of water than either of the other two common methods and produces
correspondingly greater waste volumes, as well as resulting in greater
leaching of organics into waste stream, such as sugars and acid from cut*
apples, and starch from cut potatoes. Since the extent of leaching is a
function of contact time in the fluid, it would behoove the processor,
from a loss-minimization standpoint, tc keep product detention time in
such flumes to a minimum. Usually the transport water is reused by
recycling.
Pumping, employing a high percentage of recirculated water, is almost
always used for transporting these three commodities. The increasing
importance of waste water treatment has focused attention on alternate
conveying systems. Air conveying eliminates the use of water, but it is
only suitable for raw materials of small size and not easily damaged,
such as peas. Air conveying is not practical for the three commodities
under consideration. Most likely, a mechanical belt system will replace
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many of the flume systems. A small amount of chlorinated water is
needed to spray on the belt for sanitation purposes during the
operation. Also, it is necessary, through the use of brushes, vapors
and water sprays, to prevent the buildup of organic material in the
conveyor system.
In many instances, the transport water is also used to cool the product
after blanching or to wash the pieces after a cutting operation or to
prevent oxidation of the product. In this manner, the transport water
serves a dual or multi-purpose function. Thus, the particular water
transport system must be carefully evaluated before conversion to a
mechanical conveying system.
Blanching
The blanching of vegetables and some fruits for canning, freezing or
dehydrating has several purposes:
1. Elimination of intercellular air to reduce or
eliminate subsequent oxidation.
2. Removal of starch and the inactivation of enzymes.
3. Destruction of bacteria.
4. Improvement of product texture.
5. Reduction of color loss in subsequent operations.
Vegetables are blanched either in water or in steam at various
temperatures and times. Water blanching is generally used for canned
vegetables and steam blanching for frozen or dehydrated vegetables.
Vegetables are water blanched prior to canning in order to remove air
and to leach solubles for clarity of brine. These are factors appearing
in the USDA grades of canned vegetables. For freezing and dehydrating,
destruction of enzymes is more important. Blanching in water removes
more solubles, including minerals, sugars and vitamins, than does steam
blanching. Steam blanching will in many instances use less water and
have a greater yield of product than water blanching because of a
reduced amount of leaching that takes place.
In European food processing plants, the blancher water is often
recirculated to permit a buildup of soluble solids within the water
system. This procedure will decrease the product loss, but it can also
adversely affect the removal of undesirable leachables from the product.
The pollution loads from blanching are a significant portion of the
total pollution load in the effluent stream during the processing of
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certain vegetables. The blanching of potatoes may contribute over 20
percent of the BOD waste load.
In addition to the conventional hot water and steam blanching methods, a
number of alternative methods have been explored in an effort to reduce
the waste water volume derived from this process. Fluidized bed
blanching and IQB (individual quick blanching) have been investigated,
but neither appears to have the potential for almost complete
elimination of waste water. Hot air blanching has received periodic
interest, but the requirement of recirculating large volumes of air and,
also, the high energy costs have hindered the commercial development of
this concept. More recently, microwave and hot gas blanching (based on
the direct use of hot natural gas combustion products as the major heat
source) have shown premise for substantially reducing the volume of
waste water while providing commercially acceptable blanching. The
capital costs of microwave blanching are too high for a seasonal
operation. Blanching is not required in many apple and citrus
operations and the low water volume methods discussed would be less
applicable to products such as potatoes, where a desirable function of
hot water blanching is the removal of some of the leachable soluble
solids.
Another possibility which was considered was to not only to clean, but,
also, to blanch the vegetable products at decentralized locations close
to harvest areas. The blanched product then would be cooled and
transported to a centralized plant for either canning or freezing. This
processing concept has the advantage of using spray irrigation for the
disposal of the blanching waste load to areas which are more readily
available and acceptable.
Can Rinsing and Cooling
The product is transported to the canning department where it is placed
in containers which are then filled with juice, syrup or brine.
Spillage of product and liquid are the major waste sources in the
packing operation.
To seal the containers under vacuum, open cans are heated to expel air.
Additionally, some products are cooked in the can in continuous cookers.
After such heat-producing treatment, the sealed cans must be cooled and
water from a recirculated water system is commonly used for this
purpose. Little organic contamination of the water occurs, but very
large volumes are required. From 11 to 26 percent of the plant water
flow may be required in the can cooling operation.
Cleanup
Wastes resulting from periodic house cleaning are generated from every
portion of the process. Due to their short term and transient nature,
they are almost impossible to characterize individually.
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In a typical apple, citrus or potato processing plant up to 35 percent
of the total waste load may originate from the clean-up operations. The
amount and strength of wastes generated in clean-up will depend upon the
age, condition and layout of the plant as well as the specific operating
practices employed. Some of the many techniques used to control waste
generation from clean-up activities are listed below. Most are
presently used in the food processing industry; each of them is
applicable.
1. High pressure nozzles with specially designed nozzels to
minimize water use.
2. Automatic shut-off on clean-up hoses so that water flow
stops when the hose is put down.
3. Automatically timed clean-up cycles where the water flow
shuts down after predetermined interval.
4. Automatic cleaning of conveyers, piping and other equip-
ment wherever possible.
5. The use of squeeges in place of water for cleaning up
spilled solids.
6. Cleaning gutters of solids promptly before solubles can
be leached into the water.
7. Pulling the drain bracket only after cleanup has been
completed.
8. Separation of flows from various cleanup operations.
9. Automatic monitors that alert plant management to
increases in waste flow for strength attributable to
improper cleanup practices.
10. One plant has an employee whose full-time responsibility
is to monitor cleanup operations and to minimize water
use and waste generation.
11. The use of special cleanup crews, specifically trained
for this function.
12. Minimum use of water and detergent, consistent with
cleaning requirements.
The clean-up for apple processing is much higher than for either citrus
or potatoes. This is attributed to the method of operations used in
apple processing where there is often excessive spillage of wastes on
the floor from mechanical peelers. This waste is periodically cleaned
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up once or twice a shift. There are low waste loads attributable to
mechanical peeling and this load represents only the transport water
associated with this process step. Much of the waste load is generated
after shutdown of operations when the plant is cleaned up.
In the case of potatoes and citrus, the processing plants usually
operate nearly 24 hours per day. Consequently, there is a tendency
toward continuous clean-up, rather than a separate clean-up shift as in
the case of apples.
In-Plant Reuse of Water
A number of studies have been made in the food processing industry
related to the possible in-plant reuse of water. The results of these
studies indicate that the acceptability of procedures for reuse of water
in processing operations requires such consideration as:
1. Water is an excellent solvent and is readily modified,
chemically, physically, and microbiologically for its
intended use. A particular use may or may not render
water suitable for upstream application, such as fruit
or vegetable washing. Recovered downstream, the water
may be suitable for further use only when given enough
treatment to be considered as a potable water.
2. The soil, organic or heat loads, in the used water may
be such that considerable treatment is necessary to
render it suitable for reuse.
Water recirculation using cooling towers is a common method of water
conservation in food packing plants. Cooling tower blow-down can be
used for supply water with the various subprocesses, and evaporator
waters may be reused for processes such as initial washing.
Perhaps the most extensive work on feasibility in reuse of water has
been done with "counter-current" flow systems. An example is the use of
cooling water to wash products following blanching, and this water in
turn used for initial washing of incoming raw product or the blanching
of the product and then washing the incoming raw material. Consideration
has been given to segregation of various waste waters in the process
plant for immediate reuse or reuse after suitable treatment for certain
operations. Due to bacteriological and product quality considerations,
the treatment required for reuse of the water may be relatively simple,
such as chlorination and screening, or, may become quite involved,
requiring sedimentation, flocculation, and filtration or other unit
operations.
Multiple use of water is being applied in commercial processing of
fruits and vegetables. This has unquestionably permitted conservation
of water and greater efficiency in the treatment required for the total
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plant effluent. However, in some instances it has not reduced the total
amounts of organics being generated per ton of product.
In some citrus processing plants, the recycling of can-cooling water,
barometric condenser water, refrigeration cooling water, water for pump
seals, and cooling water for heat exchangers are all being successfully
recycled. There are two factors to be considered in conditioning any
waste water for reuse:
1. The economic factor, that is, the cost of fresh water
versus the cost of treating and recirculating it for
reuse, and the cost of disposal of waste water following
its use.
2. The acceptability of the treated water for its intended
use. The costs for treatment of water depend on the
condition of the water and the treatment required to
recondition it. If the water has acquired salt, sugar,
starch, acids, or other organic or suspended materials,
extensive treatment may be necessary. On the other hand,
such treatment may be necessary anyway to reduce the
total effluent degradation, or because such effluent can-
not be discharged into either municipal systems or
navigable water systems without treatment.
A reduction in water use within the process plant does not always
reflect immediately an equivalent reduction in the waste load being
generated. Accordingly, a few processors may not realize immediate
benefits from a water reuse program. However, as more stringent waste
effluent limitations are set and the industry moves closer to zero
discharge of pollutants, the reduction in the water usage will reflect
in lower investment and operating costs for disposal of wastes.
Many of the in-plant controls described above are presently practiced at
apple, citrus and potato plants. From Section V (Tables 19-21), there
are several plants that have exemplary raw waste loads. An apple sauce,
slice, and juice plant has a raw waste BOD of 1.4 kg/kkg (2.8 Ib/ton)
compared to the average of 5 kg/kkg (10 Ib/ton) . A citrus juice, oil
and feed processing plant has a water usage of only 710 1/kkg (170
gal/ton) , BOD of 0.45 kg/kkg (0.9 Ib/ton) and SS of 0.02 kg/kkg (0.04
Ib/ton). These values compare with average flow values of 10,120 1/Jckg
(2425 gal/ton) , average BOD of 3.2 kg/kkg (6.4 Ib/ton) and average SS of
1.3 kg/kkg (2.6 Ib/ton). A frozen potato plant has a water usage of
4090 1/kkg (980 gal/ton) and a BOD of 4.45 kg/kkg (8.9 Ib/ton) compared
with average values of 11,300 1/kkg (2710 gal/ton) and 22.9 kg/kkg "(45.8
Ib/ton). Thus, there are processors achieving high levels of pollutant
reduction through in-plant waste management techniques.
The exemplary raw waste loads described above are applicable to the best
available technology economically achievable. However, exemplary waste
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water treatment systems currently operational at processing plants have
been used to determine the best available level of effluent reduction.
While these in-plant controls are not required to meet the standards,
their utilization is encouraged.
WAgTE TREATMENT TECHNOLOGY
PRELIMINARY TREATMENT SYSTEMS
In modern cannery practice there has been an almost uniform acceptance
of the need for separating solid wastes from the principal effluent
waste stream. Treatment processes employed in this separation are
physical in nature and include screening, plain sedimentation,
hydroclones and flotation. These processes are applicable to all apple,
citrus or potato plants regardless of size, age or location.
Flow Equalizing Tank
Flow equalization facilities consist of a holding tank and pumping
equipment designed to reduce the fluctuations in flow of waste effluent
streams. They can be economically advantageous whether a processing
plant is treating wastes or discharging into a city sewer after some
pretreatment. The equalizing tank stores waste water either for recycle
or to feed the flow uniformly to treatment facilities throughout a 24-
hour day period.
Screening
Screening is the most widely accepted method of preliminary treatment of
cannery wastes. Ordinarily, its cost is nominal relative to the
benefits derived in the reduced load on waste treatment or sewage
facilities. However, it is not usually considered as an economic method
of solids separation when high degrees of removal are required. Recent
improvements in the fabrication of screen cloths are permitting smaller
particulate matter to be removed. Also, the introduction of synthetic
cloths (polyester, nylon, polyethylene) has resulted in low maintenance
costs. Screens utilizing synthetic cloth with 5 to 10 micron openings
are commercially available and have a good resistence to blinding.
Three types of screens have been used for screening food processing
wastes: stationary, revolving, and vibrating. Most of the screens in
current use are of the rotary type, but the vibrating screens have been
favored because they tend to have fewer clogging problems, to provide a
drier screenings discharge, and to produce more compact solids.
Nearly all processing plants use some form of screening. Primary
screens are usually equipped with a screen cloth in the size range of 20
to 40 mesh. However, because of the industrial preference to use
relatively simple, standard equipment, there has been a gradual shift in
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the direction of stationary wedge-wire screens with an equivalent mesh
opening. This does not represent any real change with respect to the
removal of solids for waste control.
Stationary aScreens - The primary function of a stationary screen is to
separate or "free" the solids from the transporting fluids. This can be
accomplished in several ways, and in most older concepts only gravity
drainage is involved. A concave screen has been designed using high
velocity pressure-feeding. This design employs bar interference to the
slurry which cuts off thin layers of the flow over the curved surface.
This method can very effectively handle slurries containing fatty or
sticky fibrous suspended matter. Openings between the bars or wires of
0.025 to 0.15 cm (0.010 to 0.060 inches) meet normal screening needs.
£2£§£Y._5creens - One type of barrel or rotary screen, driven by external
rollers, receives the waste water at one open end and discharges the
solids at the other open end. The liquid flows outward through the
screen (usually stainless steel screen cloth or perforated metal) to a
receiving box and effluent piping mounted below the screen with a line
of external spray nozzles directed on the screen. This type is popular
and may be useful in removing solids from waste streams containing low
solids concentrations.
Vibrating Screens - The effectiveness of vibrating screens depends on a
rapid motion. They operate between 900 rpm and 3600 rpm; the motion can
either be circular, straight line, or three dimensional, varying from
0.08 to 1.27 cm (1/32 to 1/2 inch) total travel. The speed and motion
are selected by the screen manufacturer for the particular application.
Most important in the selection of a proper vibrating screen is the use
of the proper cloth. The capacities of vibrating screens are based on
the percent of open area of the cloth. The cloth is selected with the
proper combination of strength of wire and percent of open area. If the
waste solids to be handled are heavy and abrasive, wire of a greater
thickness and diameter should be used to assure long life. However, if
the material is light or sticky in nature, the durability of the
screening surface may be the smaller consideration. In such a case, a
light wire may be necessary to provide an increased percent of open
area.
The effectiveness of screening the raw waste load from a food processing
plant is illustrated by the following examples:
1. A 24-mesh oscillating screen removed 60 percent of
the suspended solids from a potato-carrot waste
effluent.
2. A 28-mesh rotary screen removed 79 percent of the
suspended solids from a tomato processing waste
effluent.
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There is a good deal of experimentation under way in the direction of
better solids removal equipment which uses finer mesh screens. An
example of this new technology is the micro-screen. The impact on this
development on waste loads is difficult to assess at this time. The use
of fine mesh screens such as the micro-screen will require some sort of
pre-screening ahead of it to act as an insurance or protective device.
Grease Removal (Catch Basins)
Most waste treatment plants do not possess the facilities to handle
large amounts of grease. Adequate grease trapping should be provided at
the processing plant and, in some cases, emulsion breaking may be
required to remove the oil and grease.
The presence of grease and related wastes often causes severe problems
in the waste treatment facility. In one instance, the processing plant
was producing french fried products, and many of the wastes generated in
this process were highly emulsified, compounding the grease removal
problem. Improved grease trapping facilities at various points in the
plant were necessary to correct the problem.
In the past twenty years, with waste treatment gradually becoming an
added economic incentive, catch basin design has been improved, the
concern shifting toward overall effluent quality improvement and toward
by-product recovery. Gravity grease recovery systems will remove 20 to
30 percent of the BOD5, 40 to 50 percent of the suspended solids and 50
to 60 percent of the grease (hexane solubles).
Most gravity grease recovery basins (catch basins) are rectangular.
Flow rate is the most important criterion for design; 30 to 40 minutes
detention time at one hour peak flow is a common sizing factor. The use
of an equalizing tank ahead of the catch basin obviously minimizes the
size requirement for the basin. A shallow basin - up to 1.8m (6 feet) -
is preferred. A "skimmer" skims the grease and scum off the top into
collecting troughs. A scraper moves the sludge at the bottom into a
submerged hopper from which it can be pumped.
Usually two identical catch basins, with a common wall, are desirable so
operation can continue if one is down for maintenance or repair. Both
concrete and steel tanks are used for the catch basin.
Flotation
A high percentage of the solids in carbonaceous food processing wastes
can be removed by vacuum flotation. When wastes are subjected to a
short period of aeration with 0.185 to 0.37 cubic meters of air per
thousand liters (0.025 to 0.05 cubic feet of air per gallon) of waste
effluent, then passed on to a compartment where the large air bubbles
can escape, and finally the liquid is sent to a holding tank where it is
subjected to a vacuum of about 0.27 to 0.33 atmospheres (8-10 inches of
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mercury). The solids quickly rise to the surface with the released
small bubbles forming a relatively dense mat which is removed by
mechanical skimmers.
There are three process alternatives varying by the degree of waste
water that is pressurized and into which the compressed air is mixed.
In the total pressurization process the entire waste water stream is
raised to full pressure for compressed air injection. In partial
pressurization, only a part of the waste water stream is raised to the
pressure of the compressed air for subsequent mixing. In the recycle
pressurization process, treated effluent from the flotation tank is
recycled for mixing with the compressed air and then, at the point of
pressure release, is mixed with the influent waste water. This
alternative has a side-stream of influent entering the retention tank,
thus reducing the pumping required in the total pressurization process.
Operating costs may vary slightly, but performance is essentially equal
among the alternatives.
Improved performance of the air flotation system is achieved by
coagulation of the suspended matter prior to treatment. This is done by
pH adjustment or the addition of coagulant chemicals, or both. A slow
paddle mix will improve flocculation.
Since there are only a few installations of flotation units in the food
processing industry, it must be recognized that experience with the
application of this technique is limited.
One example of a flotation unit is in the treatment of tomato and peach
waste water. Flows of 285,200 liters/square meter (7,000 gallons/square
foot) of surface area per day were attained in this pilot installation,
while removing 50 to 80 percent of the suspended solids.
Sedimentation
Sedimentation without prior chemical treatment has been used in the food
processing industry. For example, a waste flow of 720,000-1,665,000
liters per day (190,000-440,000 gallons per day) was settled (after
screening) in two concrete settling tanks 15.2 meters (50 feet) long by
3.7 meters (12 feet) wide by 0.9 meters (3 feet) deep with a detention
time of about 1.5 hours. The settled sludge was allowed to accumulate
to a depth of about 30.5 cm (12 in) over a 3 to 7 day period and was
then removed and hauled to fields for disposal. Later improvements
provided for continuous mechanical sludge removal from the settling
tanks.
Sedimentation was used in this instance to reduce the solids loading on
another part of the treatment process. It was found that sedimentation
prior to lagooning lessened the odor from lagoons. Primary sedimenta-
tion has been found to reduce the BOD5 between 50 to 80 percent and
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reduce the suspended solids between 30 to 75%, depending on the
characteristics of the waste water.
An example of a dual sedimentation system is the potato processing
industry where it is general practice to utilize primary sedimentation
of the plant effluent and a separate sedimentation system for silt
water. Potato wash water is reused after it has been pumped to a
clarifier or holding pond for removal of settleable solids.
If settling tanks are used, the settled solids must be collected and
withdrawn from the bottom of the tank. In municipal sewage treatment,
the solids are continually collected by mechanical means through chain-
driven wooden scrapers moving slowly along the bottom of the rectangular
ta nk.
Centrifugal Separation
The centrifugal separation of cannery waste solids has not received wide
acceptance in the food processing industry, apparently because of both
high capital cost and high power cost. In some instances horizontal
bowl centrifuges have been installed and in other instances hydroclones
have been employed.
Hydroclones are experiencing the greater degree of acceptance than
centrifuges because of low initial cost and operating cost. Currently,
they are not only being installed on waste effluent streams to remove
some of the organic solids but also on in-plant potato processing flows
to recover crude starch slurries.
Centrifuges can probably remove at least as much BOD5 and suspended
solids as does primary sedimentation. One potato processor has reported
a BOD reduction of 1700 mg/1 through the use of hydroclones in the waste
effluent stream leaving the plant.
CHEMICAL TREATMENT
pH Adjustment
Caustic is often used in peeling potatoes and apples. The use of
caustic may raise the pH of the total effluent enough to disrupt a
biological treatment, in which case the pH is adjusted to avoid
"slugging" the system with caustic. Although high pH accompanies lye
peeling, processors handle peel wastes in a manner that does not affect
the value of the solid waste as feed for livestock. Fruitr tomator and
root crops peeled in other ways may yield an effluent with neutral or
low pH. Drastic fluctuations in pH occur when lye peeling tanks are
dumped periodically and smaller fluctuations may result from the caustic
solutions used in plant cleanup. The pH of the waste water can be
adjusted by the addition of an acid, for instance, sulfuric acid.
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Another situation requiring pH adjustment can arise when fruits contain
acid and pectin, such as citrus or apples. In some biological systems5
trouble is encountered with bulking sludges associated with filamentous
growth. Increasing the pH, for instance by adding lime, may correct the
problem.
Biological systems function at their optimum when the pH is neutral
(i.e. 7.0), and they will operate effectively at a pH range between 6.0
and 9.0.
Chlorination
Chlorination is, also, used for odor control and is chiefly used in
municipal water treatment as a disinfectant and partially to reduce the
BOD5 of the treated effluent. (Biological processes should be relied on
to provide BOD5 reduction, rather than chlorination). Chlorine is
available in powdered form, as liquefied chlorine, and in solutions.
Adding chlorination to a treatment process presents the need to
construct chlorine handling facilities consisting of storage, phase con-
version, mixing, and detention facilities for effluent. Since chlorine
is a hazardous substance, special safety precautions in storage and
handling are required. Dose rates for chlorine for domestic sewage are
usually in the range of 3 to 15 parts per million with detention times
up to one hour in duration. Dosage should be high enough to provide a
chlorine residual in the effluent to assure protection against
pathogenic bacteria.
Chlorination is used to inhibit algae growth. This is of special
importance for correcting one type of bulking sludge problem in some
activated sludge plants.
Chlorination may also be used for disinfection and to oxidize residual
organic material. It is practiced on treated wastewaters to a limited
degree. This practice can be expected to become common to permit the
recycle of highly purfied waters.
Chlorine, also, provides a residual protection against bacteria that
other disinfectants, such as ozone or bromine, do not provide. Actual
chlorination rates should be based on laboratory testing of the
effluent.
Nutrient Addition
Cannery waste water is generally deficient in both nitrogen and
phosphorus from the standpoint of the ratio of these elements to organic
matter that is required for optimum biological treatment. This
situation can be corrected by adding ammonia and phosphoric acid, for
example, to the waste water before biological treatment. The chemicals
should be added after initial screening and settling to avoid their loss
to the solids removed in these steps.
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Chemical Coagulation and Precipitation
Chemical precipitation of cannery wastes has been used with varying
degrees of success. Investigators have reported reductions in BOD5 as
high as 89 percent. In almost all instances lime was the coagulant used
whether singularly or in conjunction with another coagulant or coagulant
aid. Doses of coagulants required were much higher for food processing
wastes than those required for domestic sewage alone, since the
suspended solids concentrations in food processing wastes are much
higher than domestic wastes.
Most chemical precipitation processes in use are batch type; some
continuous processes have also been reported. With the fill and draw
technique, a minimum of two tanks is required for treatment. This
system has the advantage of permitting easy handling of large volumes of
sludge. The continuous flow system has the disadvantages of minimum
flexibility in maintaining optimum dosages and its inability to
accommodate removal of large sludge volumes.
It has been reported that chemical precipitation gave smaller BOD5
removals than biological filtration, but that it, also, had some
advantages compared to trickling filters. Biological filters required
time to develop a satisfactory filter flora and had to be used
continuously; whereas, chemical precipitation could be utilized
immediately and intermittently. This is particularly advantageous in
the seasonal canning industry.
In some processing plants, lime and alum were added to the waste
effluents from pea processing prior to screening. This resulted in a 42
percent BOD5 removal and an 81 percent removal of the suspended solids.
Miscellaneous Chemical Additives
Chemical additives may also be added to waste waters to control foaming
and to control odors and to enhance solid settling characteristics such
as is accomplished by coagulating agents.
PRIMARY TREATMENT SYSTEMS
The typical primary treatment system operating in the food processing
industry consists of a clarifier and rotary vacuum filter to remove and
dewater the settled sludge from the waste effluent stream. Chemical
precipitation may be used for those waste sludges that are not readily
settleable, and suspended solids may be removed from effluents by the
addition of an air flotation unit.
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Settling, Sedimentation and Clarification
A substantial portion of the suspended solids that cannot be
conveniently removed by screening can be separated by sedimentation,
settling or clarification. Settling consists of providing a
sufficiently large tank or pond so that the velocity of the water is
reduced. The forces arising from density differences between the solids
and the water can then act and the solids can settle. Clarifiers
operate on the same principle with the addition of mild mechanical
agitation to assist in the settling process and the removal of the
settled solids. As an initial step preceding biological treatment, a
combination of screening and clarification can be expected to remove 50
to 80 percent of the waste water BOD5. With the addition of chemicals
for coagulation BOD5 removals range from 25 percent to 40 percent of raw
influent and suspended solids removal range from 40 percent to 7056. It
is, also, found that sedimentation prior to lagooning lessened the odor
from lagoons. Clarifiers are, also, used as a part of the activated
sludge process, serving to separate sludge for return to the aeration
step or to anaerobic digestion. Settling ponds or Clarifiers are, also,
used as a final step in biological systems for the removal of solids
prior to discharge of the treated wastewater. In the processing of
apple or citrus waste effluents, the presence of pectin often restricts
the removal of solids by clarification. Therefore, sedimentation is
less frequently practiced in these industries than in the potato
industry.
Rotary Vacuum Filtration
The settled solids removed from the bottom of the clarifier, in the form
of a sludge, are pumped to the rotary vacuum filter, where the slurry is
concentrated by removal of water which is returned to the clarifier.
The outside surface of the filter cylinder is covered with a filter
medium (cloth). The lower portion of the filter is suspended in the
liquid slurry. As the drum rotates, the vacuum maintained within the
cylinder forces fluid into the cylinder leaving a layer of solids on the
outside filter medium. As the filter rotates, the solids are scraped
off from the cloth. This method has been widely used in solids
thickening for both industrial and municipal wastes.
The dewatered solids are then discarded by one of the ultimate disposal
techniques or used for animal feeds, and the water is recycled back to
the clarifier.
BIOLOGICAL TREATMENT SYSTEMS
The treatment of waste effluents by biological methods is an attractive
alternative when a high proportion of the biodegradable material is in
the soluble form, as is the case in the canned and preserved fruits and
vegetables industry. These methods are applicable in this industry
irrespective of plant size, age or location.
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Many types of microoganisms remove organic materials from liquid wastes.
Those most commonly used in treatment systems are heterotrophs, which
utilize organic carbon for their energy and growth. Some are aerobic
and require molecular oxygen for converting wastes to carbon dioxide and
water. Others are anaerobic and grow without molecular oxygen.
Anaerobic microorganisms grow more slowly than aerobes and produce less
sludge per unit of waste treated than do aerobic microorganisms.
Anaerobes, also, release acids and methane, and their action on sulfur-
containing wastes may create odor problems. Some microorganisms are
facultative; that is, they can grow in either an aerobic or anaerobic
environment.
The biological treatment of food processing wastes often lacks necessary
nutrients in the waste to sustain desirable biological growth. Added
nutrients, most often nitrogen and sometimes phosphorus, may be required
for efficient biological treatment of food processing wastes.
Processing wastes generally requires the addition of nitrogen before
successful biological treatment. Often this can be economically
accomplished by the addition of nutrient-rich wastes from another source
for combined treatment.
A discussion of the various methods of biological treatment is presented
in the following sections.
Activated Sludge
In this case the active biota is maintained as a suspension in the waste
liquid. Air, supplied to the system by mechanical means, mixes the
reaction medium and supplies the microorganisms with the oxygen required
for their metabolism. The microorganisms grow and feed on the nutrients
in the inflowing waste waters. There are fundamental relationships
between the growth of these microorganisms and the efficiency of the
system to remove BODJ5.
A number of activated sludge systems have been designed, all of which
have their own individual configurations. Basically, these designs
consist of some type cf pretreatment, usually primary sedimentation, and
aeration, followed by sedimentation which will allow the sludge produced
to separate, leaving a clear effluent. Portions of the settled sludge
are recirculated and mixed with the influent to the aeration section,
usually, at a proportion ranging between 10 to 100 percent, depending
upon the specific modification ot the basic activated sludge process.
The goal of these plants is to produce an actively oxidizing microbial
population which will also produce a dense "biofloc" with excellent
settling characteristics. Usually, optimization of floe growth and
overall removal is necessary since very active microbial populations do
not always form the best floes.
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Activated sludge treatment plants are capable of removing 90 to 95
percent or better of the influent BOD5 from fruit and vegetable
processing plants.
Activated sludge systems will remove over 95 percent BOD5 in apple
processing wastes; however, nitrogen has to be added to avoid bulking of
the activated sludge. Nitrogen is usually added as anhydrous ammonia or
ammonium sulfate in amounts sufficient to obtain a carbon: nitrogen
ratio of 30:1 in the waste stream.
For treating potato processing wastes, a mixed liquor system is
satisfactory, affording BOD5 removals as high as 95 percent. Contact
stabilization, removed only about 80 percent of BOD5_ and a modification
may not be considered satisfactory unless the processor reduces the
waste loadings by in-plant modifications.
When settled sludge was reaerated, 90-95 percent BOD5 removal was
obtained as long as the BOD5 loading was less than 50 to 70 kg(Ib) BOD5
per day per 100 kg(lb) of sludge solids. This rate decreased to less
than 70 percent BOD5 removal when the loading rate approached 200 kg(lb)
per day per 100 kg(Ib) of sludge solids. Ihe sludge formed at these
higher rates was less stable and bulking became a problem.
The treatment of citrus wastes using a step aeration type system,
obtained up to 97 percent BOD5 removal (averaging 90 percent removal) at
loadings of 2.6-4.2 kg of BOD5 per cubic meter per day (0.16 to 0.26 Ibs
of BOD5 per cubic foot per day). No addition of nitrogen was necessary
at these loading rates. Higher loading rates were followed by bulking
primarily caused by Sphaerotilus. Temperatures above 36°C were
detrimental and at 43°C were lethal to the system. Conventional
activated sludge methods for the treatment of citrus wastes, 30-50 mg/1
nitrogen and 5-10 mg/1 phosphorus had to be added to obtain higher rates
of BOD5 removal and sludge with good settling characteristics.
The extended aeration modification of the activated sludge process is
similar to the conventional activated sludge process, except that the
mixture of activated sludge and raw materials is maintained in the
aeration chamber for longer periods of time. The common detention time
in extended aeration is one to three days, rather than six hours.
During this prolonged contact between the sludge and raw waste, there is
ample time for organic matter to be adsorbed by the sludge and also for
the organisms to metabolize the removal of organic matter which has been
built up into the protoplasm of the organism. Hence, in addition to
high organic removals from the waste waters, up to 75 percent of the
organic matter of the microorganisms is decomposed into stable products
and consequently less sludge will have to be handled.
In extended aeration, as in the conventional activated sludge process,
it is necessary to have a final sedimentation tank. Some of the solids
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resulting from extended aeration are rather finely divided and therefore
settle slowly, requiring a longer period of settling.
The long detention time in the extended aeration tank makes it possible
for nitrification to occur. If it is desirable for this to occur, it is
necessary to have sludge detention times in excess of three days. This
can be accomplished by regulating the amounts of sludge recycled and
wasted each day. Oxygen enriched gas could be used in place of air in
the aeration tanks to improve overall performance. This would require
that the aeration tank be partitioned and covered, and that the air
compressor and dispersion system be replaced by a rotating sparger
system, which costs less to buy and operate. When co-current, staged
flow and recirculation of gas back through the liquor is employed,
between 90 and 95 percent oxygen utilization is claimed. Although this
modification of activated sludge has not been used in treating apple,
citrus or potato processing wastes, it is being used successfully for
treating other organic wastes
Activated sludge in its varied forms is an attractive alternative in
cannery waste treatment. Conventional design criteria is not directly
transferrable from municipal applications. However, high levels of
efficiency are possible at the design loadings normally employed in
treating other types of high strength organic wastes. The general
experience has been that biological solids separation problems can be
avoided: if the dissolved oxygen concentration remains above zero
throughout the aeration basin, if management minimizes very strong,
concentrated waste releases, and if sufficient amounts of nitrogen are
available to maintain a critical nitrogen: BOD5> ratio. This ratio has
been recommended to be 3 to 4 kg(lb) N per 100 kg(lb) of BOD5 removed.
Numerous cases have been reported of successful combined treatment of
cannery and domestic wastes by activated sludge and its modifications.
Activated sludge systems require less room than other high reduction
biological systems, but have higher equipment and operating costs.
Properly designed and operated systems can treat cannery wastes to
achieve high BOD reductions.
Biological Filtration (Trickling Filter)
The trickling filter process has found application in treatment of food
processing wastes. Very tall filters employing synthetic media, high
recirculation, and forced air circulation have been used to treat strong
wastes in the 300-4000 mg/1 BOD5 range.
The purpose of the biofilter system is to change soluble organic wastes
into insoluble organic matter primarily in the form of bacteria and
other higher organisms. As the filter operates, portions of the
biological growth slough off and are discharged as humus with the filter
effluent. Usually, some physical removal system is required to separate
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this insoluble organic material which can be treated by other suitable
methods, usually anaerobic fermentation in a sludge digestor.
Trickling filters are usually constructed as circular beds of varying
depths containing crushed stone, slag, or similar hard insoluble
materials. Liquid wastes are distributed over this bed at a constant
rate and allowed to "trickle" over the filter stones. Heavy biological
growths develop on the surface of the filter "media" throughout the
depth of the filter and, also, within the interstitial spaces.
The biological film contains bacteria; (Zooglea, Sphaerotilus, and
Beggiatoa) ; fungi (Fusarium, Geotrichum, Sepedonium) ; algae, both green
and blue-green (Phormidium, Ulothrix, Mononostrona); and a very rich
fauna of protozoa. A grazing fauna is, also, present on these beds
consisting of both larval and adult forms of worms (Oligochaeta),
insects (Diptera and coleoptera, among others), and spiders and mites
(Arachnida) .
A common problem with this type of filter is the presence of flies which
can become a severe nuisance. Insect prevention can usually be
prevented by chlorinating the influent or by periodically flooding the
filter.
Recirculation of waste water flows through biological treatment units
are often used to distribute the load of impurities imposed on the unit
and smooth out the applied flow rates. Trickling filter BOD5 removal
efficiency is affected by temperature and the recirculation rate.
Trickling filters perform better in warmer weather than in colder
weather. Recirculation of effluent increases BOD5 removal efficiency as
well as keeping reaction type rotary distributers moving, the filter
media moist, organic loadings relatively constant, and increases contact
time with the biologic mass growing on the filter media.
Furthermore, recirculation improves distribution, equalizes unloading,
obstructs entry and egress of filter flies, freshens incoming and
applied waste waters, reduces the chilling of filters, and reduces the
variation in time of passage through the secondary settling tank.
Trickling filter BODjj removal efficiency is inversely proportional to
the BODE> surface loading rate; that is, the lower the BODJ5 applied per
surface area, the higher the removal efficient. Approximately 10-90
percent BOD reduction can be attained with trickling filters.
Anaerobic Processes
Elevated temperatures (29° to 35°C or 85° to 95°F) and the high
concentrations typically found in apple, citrus or potato wastes make
these wastes well suited to anaerobic treatment. Anaerobic or
faculative microorganisms, which function in the absence of dissolved
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oxygen, break down the organic wastes to intermediates, such as organic
acids and alcohols. Methane bacteria then convert the intermediates
primarily to carbon dioxide and methane. Also, if sulfur compounds are
present, hydrogen sulfide may be generated. Anaerobic processes are
economical because they provide high overall removal of BOD5 and
suspended solids with no power cost (other than pumping) and with low
land requirements. Two types of anaerobic processes are possible:
anaerobic lagoons and anaerobic contact systems.
Anaerobic lagoons are used in the industry as the first step in
secondary treatment or as pretreatment prior to discharge to a municipal
system. Reductions of 85 percent in BOD5 and 85 percent in suspended
solids can be achieved with these lagoons. A usual arrangement is two
anaerobic lagoons relatively deep (3 to 5 meters, or about 10 to 17
feet), low surface-area systems with typical waste loadings of 240 to
320 kg BOD5/1000 cubic meters (15 to 20 Ib BOD5/1000 cubic feet) and a
detention time of several days.
Plastic covers of nylon-reinforced Hypalon, polyvinyl chloride, and
styrofoam can be used on occasion to retard heat loss, to ensure
anaerobic conditions, and hopefully to retain obnoxious odors. Properly
installed covers provide a convenient method for collection of methane
gas.
Influent waste water flow should be near, but not on, the bottom of the
lagoon. In some installations, sludge is recycled to ensure adequate
anaerobic seed for the influent. The effluent from the lagoon should be
located to prevent short-circuiting the flow and carry-over of the scum
layer.
Advantages of an anaerobic lagoon system are: initial low cost, ease of
operation, and the ability to handle shock waste loads, and, yet,
continue to provide a consistent quality effluent. The disadvantage of
an anaerobic lagoon is odor although odors are not usually a serious
problem at well managed lagoons.
Anaerobic lagoons used as the first stage in secondary treatment are
usually followed by aerobic lagoons. Placing a small, mechanically
aerated lagoon between the anaerobic and aerobic lagoons is becoming
popular. It is currently popular to install extended aeration units
following the anaerobic lagoons to obtain nitrification.
The anaerobic contact system requires far more equipment for operation
than do anaerobic lagoons, and consequently, is not as commonly used.
The equipment consists of: equalization tanks, digesters with mixing
equipment, air or vacuum gas stripping units, and sedimentation tanks
(clarifiers) . Overall reduction of 90 to 97 percent in BOD and
suspended solids is achievable.
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Equalized waste water flow is introduced into a mixed digester where
anaerobic decomposition takes place at a temperature of about 33° to
35°C (90° to 95°F). BOD5 loadings into the digester are between 2.4 and
3.2 kg/cubic meter (0.15 and 0.20 Ib/cubic foot), and the detention time
is between three and twelve hours. After gas stripping, the digester
effluent is clarified and sludge is recycled at a rate of about one-
third the raw waste influent rate. Sludge at the rate of about 2
percent of the raw waste volume is removed from the system.
Advantages of the anaerobic contact system are high organic waste load
reduction in a relatively short time; production and collection of
methane gas that can be used to maintain a high temperature in the
digester and also to provide auxilary heat and power; good effluent
stability to waste load shocks; and application in areas where anaerobic
lagoons cannot be used because of odor or soil conditions.
Disadvantages of anaerobic contractors are high initial and maintenance
costs and some odors omitted from the clarifiers.
Anaerobic contact systems are usually used as the first stage of
secondary treatment and can be followed by the same systems that follow
anaerobic lagoons or trickling filter roughing systems.
Other Aerobic Processes
Aerated lagoons have been used successfully for many years in a number
of installations for treating apple, citrus, or potato wastes. However,
with recent tightening of effluent limitations and because of the
additional treatment aerated lagoons can provide, the number of
installations is increasing.
Aerated lagoons use either fixed mechanical turbine-type aerators,
floating propeller-type aerators, or a diffused air system for supplying
oxygen to the waste water. The lagoons usually are 2.4 to 4.6 m (8 to
15 feet) deep, and have a detention time of two to ten days. BOD5
reductions range from 40 to 60 percent with little or no reduction in
suspended solids. Because of this, aerated lagoons approach conditions
similar to extended aeration without sludge recycle.
Advantages of this system are that it can rapidly add dissolved oxygen
(DO) to convert anaerobic waste waters to an aerobic state; provide
additional BOD5_ reduction; and require a relatively small amount of
land. Disadvantages are the power requirements and that the aerated
lagoon, in itself, usually does not reduce BOD5 and suspended solids
adequately to be used as the final stage in a high performance secondary
system. Aerated lagoons are usually a single stage of secondary
treatment and should be followed by an aerobic (shallow) lagoon to
capture suspended solids and to provide additional treatment.
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Aerobic lagoons (or stabilization lagoons or oxidation ponds), are large
surface area, shallow lagoons, usually 1 to 2.3 m deep (3 to 8 feet),
loaded at a BODJjj rate of 22-56 kilograms per hectare (20 to 50 pounds
per acre). Detention times will vary from several days to six or seven
months; thus, aerobic lagoons require large areas of land.
Aerobic lagoons serve three main functions in waste reduction:
1. Allow solids to settle out.
2. Equalize and control flow.
3. Permit stabilization of organic matter by aerobic and facultative
microorganisms and also by algae.
Actually, if the pond is quite deep, 1.8 to 2.4 m (6 to 8 feet), so that
the waste water near the bottom is void of dissolved oxygen, anaerobic
organisms may be present. Therefore, settled solids can be decomposed
into inert and soluble organic matter by aerobic, anaerobic or
facultative organisms, depending upon the lagoon conditions. The
soluble organic matter is, also, decomposed by microorganisms causing
the most complete oxidation. Wind action assists in carrying the upper
layer of liquid (aerated by air-water interface and photosynthesis) down
into the deeper portions. The anaerobic decomposition generally
occurring in the bottom converts solids to liquid organics which can
become nutrients for the aerobic organisms in the upper zone.
Algae growth is common in aerobic lagoons; this currently is a drawback
when aerobic lagoons are used for final treatment. Algae may escape
into the receiving waters, and algae added to receiving waters are
considered a pollutant. Algae in the lagoon, however, play an important
role in stabilization. They use CO2, sulfates, nitrates, phosphates,
water and sunlight to synthesize their own organic cellular matter and
give off free oxygen. The oxygen may then be used by other
microorganisms for their metabolic processes. However, when algae die
they release their organic matter in the lagoon, causing a secondary
loading. Ammonia disappears without the appearance of an equivalent
amount of nitrite and nitrate in aerobic lagoons. From this, and the
fact that aerobic lagoons tend to become anaerobic near the bottom, it
appears that some denitrification is occurring.
High winds can develop a strong wave action that can damage dikes;
Riprap, segmented lagoons, and finger dikes are used to prevent wave
damage. Finger dikes, when arranged appropriately, also prevent short
circuiting of the waste water through the lagoon. Rodent and weed
control, and dike maintenance are all essential for good operation of
the lagoons.
Advantages of aerobic lagoons are that they reduce suspended solids,
oxidize organic matter, permit flow control and waste water storage.
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Disadvantages are the large land required, the algae growth problem, and
odor problems.
Aerobic lagoons usually are the last stage in secondary treatment and
frequently follow anaerobic or aerated lagoons. Large aerobic lagoons
allow plants to store waste water discharges during periods of Ligh flow
in the receiving body of water or to store for irrigation during the
summer. These lagoons are particularly popular in rural areas where
land is available and relatively inexpensive.
Rotating Biological Contactor
The rotating biological contractor (RBC) consists of a series of closely
spaced flat parallel disks which are rotated while partially immersed in
the waste waters being treated. A biological growth covering the
surface of the disk adsorbs dissolved organic matter present in the
waste water. As the biomass on the disk builds up, excess slime is
sloughed off periodically and is removed in sedimentation tanks. The
rotation of the disk carries a thin film of waste water into the air
where it absorbs the oxygen necessary for the aerobic biological
activity of the biomass. The disk rotation, also, promotes thorough
mixing and contact between the biomass and the waste waters. In many
ways the RBC system is a compact version of a trickling filter. In the
trickling filter the waste waters flow over the media and, thus, over
the microbial flora; in the RBC system, the flora is passed through the
waste water.
The system can be staged to enhance overall waste water reduction.
Organisms on the disks selectively develop in each stage and are, thus,
particularly adapted to the composition of the waste in that stage. The
first couple of stages might be used for removal of dissolved organic
matter, while the latter stages might be adapted to other constituents,
such as nutrient removal.
The major advantages of the RBC system are: its relatively low
installed cost, the effect of staging to obtain dissolved organic matter
reductions, and its good resistance to hydraulic shock loads.
Disadvantages are: that the system should be housed to maintain high
removal efficiencies and to control odors. Although, this system has
demonstrated its durability and reliability when used on domestic
wastes, it has not yet been fully tested to treat apple, citrus, or
potato processing wastes.
Rotating biological contactors could be used for the entire aerobic
secondary system. The number of stages required depends on the desired
degree of treatment and the influent strength. Typical applications of
the rotating biological contactor, however, may be for polishing the
effluent from anaerobic processes and from roughing trickling filters
and as pretreatment prior to discharging wastes to a municipal system.
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A BOD5 reduction of over 90 percent is achievable with a multi-stage
RBC.
PERFORMANCE OF VARIOUS SECONDARY TREATMENT SYSTEMS
Table 25 shows BOD5 and SS removal efficiencies for various secondary
biological treatment systems used to treat wastes from apple (AP),
citrus (CI) and potato (PO) processing systems. These systems are all
in operation and many show high degrees of BOD5 and SS reduction. Three
other multiple aerated lagoon systems are, also, operating but are not
included because raw waste data is not available. Some of the systems
process wastes from each subcategory within a commodity and therefore
treatment effectiveness is applicable to each commodity subcategory.
The range in processing plant capacity for the systems listed varies
from less than 453.5 kkg/D (500 T/D) to 5,442 kkg/D (6,000 T/D).
The most commonly used treatment systems are multiple aerated lagoons
and activated sludge. Each system has been used to treat waste water
from the processing of apples, citrus, and potatoes.
Table 25 lists three apple plants utilizing three different treatment
systems, each of which has at least 95 percent BOD5 removal. There are
four citrus plants utilizing four different treatment systems, each of
which has at least 95 percent BOD5 removal. There are three potato
plants utilizing three different treatment systems, each of which has at
least 95 percent BOD5 removal.
Reliability, operability and consistency of operation of the waste water
treatment processes found to be most frequently used in the fruit and
vegetable industry can be high if appropriate designs and operational
techniques are employed. The end-of-pipe treatment utilizing biological
systems is a well established technology that requires attention to a
limited number of variables to insure a high degree of reliability.
The most important operational aspects of these biological systems are
equipment reliability and attention to operating detail and maintenance.
Spare aeration equipment (usually floating surface aerators) improves
the possibility of consistent operation;however, many treatment systems
have an adequate overcapacity already installed as insurance against the
results of equipment failure. It is desirable to install spare
equipment at critical points, for example, sludge return pumps. Perhaps
of equal importance is a design that permits rapid and easy maintenance
of malfunctioning equipment.
Therefore, control of the biological treatment plant and the consistency
of the results obtained are largely a matter of conscientious adherence
to well-known operational and maintenance procedures. Automatic control
of biological treatment plants is far from a practical point. Although
in-line instrumentation for measurement of pH, dissolved oxygen,
temperature, turbidity and so on, can improve the effectiveness of
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operation, its use is minimal in the industry's existing waste water
treatment plants. Nevertheless, no practical in-line instrumentation
can replace the judicious attention to operational details of a
conscientious crew of operators.
An activated sludge system which is permitted to operate at a constant
P:M ratio all year round and with minimum operational changes would have
a natural variation as shown in Section IX by the solid line in Figure
10. A similar system with careful operational control would have a
controlled monthly average variation as shown by the points. Although
the mean value is the same, the amount of natural variation is
controlled by the operator through aeration rate, control, sludge
recycling and F:M ratio adjustments. These adjustments can be made
daily so that monthly averages can be held within the desired limits.
Although, a well-operated and properly designed facility can be
controlled within +25 percent of the average on a monthly operating
basis. A system with minimal operational control or an allowance of +50
percent of the averages on a monthly basis has been used to calculate
the maximum monthly effluent limitation.
r>p>a from a well operated and properly designed activated sludge system
at PO-128 demonstrates that a 50 percent allowance is justified. The
annual average BOD5 and TSS are 0.7 kg/kkg (1.4 Ib/ton) and 0.9 kg/kkg
(1.8 Ib/ton) respectively; the maximum monthly BODS and TSS discharges
are 1.04 kg/kkg (2.08 Ib/ton) and 1.32 kg/kkg (2.63 Ib/ton)
respectively. Thus, the maximum montly discharges are less than the
averages on a monthly basis plus 50 percent.
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TABLE 25
EFFECTIVENESS OF VARIOUS SECONDARY
BIOLOGICAL TREATMENT SYSTEMS
SECONDARY TREATMENT SYSTEM
BOD5.
REDUCTION
PERCENT
SS
REDUCTION
PERCENT
MULTIPLE AERATED LAGOONS
AP 121
CI 105 & 109
CI 106
CI 118
PO 110
98
98
89
87
98
79
ACTIVATED SLUDGE
AP 140
CI 123
PO 101
PO
PO
107
128
99
97
73
71
94
35
56
28
29
94
ANAEROBIC & AEROBIC LAGOONS
CI 108
PO 109
99
95
12
93
TRICKLING FILTERS
PO 127
85
92
TRICKLING FILTER & AERATED LAGOONS
AP 103
CI 127
96
98
87
80
ACTIVATED SLUDGE & AERATED LAGOONS
CI 119
PO 128
98
95
110
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ADVANCED TREATMENT SYSTEMS
A discussion of advanced treatment methods is presented in this section.
For the most part, these methods are applicable to the treatment of the
waste streams after secondary treatment involving the use of some
combination of biological treatment for reduction of BOD5 and of
settling ponds or equipment for reduction of suspended solids.
Many of the technologies discussed do not, in themselves, constitute a
complete treatment process, but would become part of a complete process.
In evaluating the treatment methods applicable to effluents from
secondary treatment operations, it is assumed that all particulate
solids greater than 20 microns have been removed from the waste effluent
stream.
Carbon Adsorption
The reduction of tastes and odors in water supplies by adsorption of the
offending substances on activated carbon is probably the most important
direct use of adsorption technology in water treatment. Columns or beds
of granular activated carbon are employed: (1) for concentrating
organic pollutants from water for purposes of analysis or, (2) for
removal of the pollutants. Some of the removal of color-producing
substances and other pollutants from water during coagulation may also
be the result of adsorption.
The fixed bed or countercurrent operation is the most effective and
efficient way of using the activated carbon. The influent comes in
contact with the adsorbent along a gradient of mounting residual
activity until the most active carbon gives a final polish to the
effluent stream.
Partial regeneration of carbon by thermal volatilization or steam
distillation of organic adsorbates is possible, but available
regeneration procedures will have to be improved or new ones invented if
adsorption is to become a widely useful operation in water treatment.
The use of multi-hearth furnaces such as used in the sugar refineries is
a possibility. Difficulties and costs of regeneration explain why
powdered activated carbon continues to be widely used.
Granular activated carbon can replace other filtering materials in
structures not unlike present-day rapid filters. Beds of granular
activated carbon can, in fact, be made to perform as both filters and
adsorbents. However, activated carbon filters must be somewhat deeper
than sand filters, even though they may be operated at somewhat higher
rates of flow per cubic meter (square foot) of bed. For adsorption, the
rate of flow per cubic meter (cubic foot) rather than per square meter
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(square foot) of bed is, understandably, the important parameter in
practice.
Distillation
This unit process has received wide attention as a method of removing
water from saline solutions where fresh water is in short supply. It
differs from most other waste treatment processes in that the recovered
water is pure and may be recycled indefinitely. Little work, if any,
has been done so far in transferring this new technology to fruit and
vegetable processing wastes.
It is not likely to be used in waste treatment, because the process
either uses a lot of fuel (as in a single step flash) or has a high
capital cost (as in a multiple flash) or a combination of both.
Electrodialysis
Water can be desalinized electrochemically by electrodialysis through
membranes selectively permeable to cations or anions. Dialysis is the
fractionation of solutes made possible by differences in the rate of
diffusion of specific solutes through porous membranes. Semipermeable
membranes are thin barriers that offer easy passage to some
constituents. High selective membranes have been prepared by casting
ion-exchange resins as thin films. Dialytic processes are common
separation techniques in laboratory and industry. The recovery of
caustic soda from industrial wastes, such as viscose press liquor from
the rayon industry and mercerizing solutions, is an example of con-
tinuous-flow dialysis.
Electrodialysis is only applicable to saline solutions of which are
readily ionized and is not applicable to the separation unionizable
soluble organics that exist in effluents from biological treatment
systems.
Eutectic Freezing
Eutectic freezing operates at the eutectic temperature of the incoming
water. Down to the eutectic point, only ice is formed. At the eutectic
point, ice crystals nucleate and grow independently of salt crystals and
other substances in the water. Further removal of heat does not
continue to lower the temperature. Both ice and sludge freeze, and they
can then be separated because the ice floats and the frozen sludge
sinks.
The freezing breaks down the sludge and destroys its waterbinding
capacity which, in turn, permits better sludge dewatering. Both
functions, the removal of water in the form of ice crystals and the
concentration of sludge by freezing have been demonstrated in a
laboratory scale only as water-inorganic salt systems.
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Filtration
Two types of filtration will be considered in this discussion: (1) sand
(slow and rapid) and (2) diatomaceous earth. A slow sand filter is a
specially prepared bed of sand or other mineral fines on which doses of
waste water are intermittently applied and from which effluent is
removed by an under-drainage system. The solids removal occurs mainly
at the surface of the filter. BOD removal occurs primarily as a
function of the degree of solids removal although some biological action
occurs in the top inch or two of sand. Effluent from the sand filter i3
of a high quality with BOD and suspended solids concentrations very low.
Slow sand filters require larger land areas than rapid filter facilities
on the order of five times (or more) as much land; however, slow sand
filters may operate up to 60 days without cleaning, whereas rapid sand
filters are usually cleaned by backwashing every 24 hours.
Slow sand filters require no extra preparatory water treatment prior to
filtration, although it is recommended, whereas, rapid sand filters are
designed to remove the remainder of solids after treatment by
coagulation, flocculation and sedimentation. Construction costs of slow
sand filters are relatively high due to the large area requirements;
however, operating and maintenance costs are relatively low since slow
sand filters may operate for long durations. Rapid sand filters have a
relatively low construction cost due to their low area requirements;
however, operating and maintenance costs are relatively high since they
cannot operate for long periods of time without backwashing. Food
processing wastes are likely to cause clogging of the filters after only
a short period of operation unless adequate treatment precedes them.
Rapid filters are subject to a variety of ailments, such as: cracking of
the bed, formation of mud balls, plugging of portions of the bed, jet
actions at the gravel-sand separation plane, sand bails, and sand
leakage into the under-drain systems. Usually these problems can be
minimized or eliminated by proper design and plant operation. Sand
filters are well noted for their efficient removal of bacteria, color,
turbidity, iron and large microorganisms.
Diatomaceous earth filters have found use as: (1) mobile units for
water purification in the field and (2) stationary units for swimming
pools and general water supplies. The filter medium is a layer of
diatomaceous earth built up on a porous septum. The resulting pre-coat
is supported by the septum, which serves also as a drainage system.
Water is strained through the pre-coat unless the applied water contains
so much turbidity that the unit will maintain itself only if additional
diatomaceous earth, called body feed, is introduced into the incoming
water and preserves the open texture of the layer.
Skeletons of diatoms 0.5 to 12 units in size compose the diatomaceous
earth mined from deposits. Pre-coating requires 0.49 to 2.44 kg (0.1 to
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this should not be necessary if the sand filter and/or carbon adsorption
system is used upstream of the ion exchange system. The effluent from
the first ion exchange column is further treated by a weak cation resin
to reduce the final dissolved salt content to approximately five mg/1.
The anion resin in this process is regenerated with aqueous ammonium and
the cation resin with an aqueous sulfuric acid. The resins did not
appear to be susceptible to fouling by the organic constituents of the
secondary effluent used in this experiment.
Other types of resins can be used for nitrate and phosphate removal, as
well as color bodies, COD, and fine suspended matter. Removal of these
various constituents can range from 75 to 97 percent, depending on the
constituent.
The cycle time on the ion exchange unit will be a function of the time
required to block or to take up the ion exchange sites available in the
resin contained in the system. Blockage occurs when the resin is fouled
by suspended matter and other contaminants. The ion exchange system is
ideally located at the end of the waste water processing scheme, thus
having the highest quality effluent available as a feed water.
The organic nature of most food processing waste effluents is not
conducive to the employment of ion exchange technology as a method of
treating waste effluent. Ion exchange has found its greatest acceptance
in the treatment of inorganic contaminants and in public waterworks.
Microscreening
Microscreening has been a viable solids-removal process for twenty
years. A microscreen consists of a rotating drum with a screen or
fabric constituting the periphery. Feedwater enters the drum internally
and passes radially through the screen with the concomitant deposition
of solids on the inner surface of the screen. At the top of the drum
pressure, jets of water are directed onto the screen to remove deposited
solids. This backwash stream of dislodged solids and washwater is
captured in a receiving hopper inside the drum and flows out through the
hollow axle of the unit. In order to reduce slime growths on the
screen, an ultraviolet lamp is continually operated in close proximity
to the screen. The driving force for the system is the head
differential between the inside and outside of the screen. As solids
are removed on the screen a mat is formed which improves the solids
removal efficiency and also results in increased head loss through the
screen. The maximum head loss is usually limited to 0.15 meters (6
inches) in order to prevent screen damage. In order to prevent the
limiting head loss from being exceeded, drum speed and wash water
pressure are increased. In newer units automatic controls handle these
adjustments.
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One type of microscreen displayed efficiencies in removal of solids from
55 to 73 percent, while another type showed 57 to 89 percent
efficiencies in tabulation of average removals. Due to differences in
feed character and operational techniques, the data could not be
compared. Individual studies demonstrated the effects of a number of
design, maintenance and operational factors on the performance of the
unit:
Design
1. Approximately one-half of the wash water applied to the
screen actually penetrates and is removed as the waste
stream with dislodged solids.
2. The waste stream is usually returned to the end of the
main plant.
3. It is desirable tc have gravity flow from the clarifier
to the microscreener to avoid shearing of the more
fragile solids.
4. Total head loss through the system is only 0.30 to 0.46
meters (12 to 18 inches) .
5. Prechiorination should be avoided in order to protect
the screen.
6. Chloride concentrations exceeding 500 mg/1 (0.0021 Ib/gal)
may cause corrosion problems.
7. Microscreens do not successfully remove floe particles
resulting from coagulation by chemicals such as aluminum
sulfate.
Maintenance
1. Screens for the pressure washing system tend to clog,
mainly due to grease in the effluent.
2. Most units will require frequent (approximately once a
week) cleaning with a hypochlorite solution which entails
a few hours of removal from service in order to clean
the fabric.
3. High iron or manganese concentrations in the feed may
necessitate an occasional acid wash of the screen to
destroy the resulting film buildup.
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Operation
1. Minimum drum speeds consistent with head loss limitations
will give the greatest removal of suspended solids.
2. Higher pressures for the jet washing system are more
beneficial than greater quantities of water.
3. High solids loadings can cause severe reductions (up to
two-thirds design capacity) in throughput as well as
acceleration of slime buildup.
Nitrification-Denitrification
Nitrification-denitrification is a two-step process used to remove
nitrogen from treated waste waters.
In the first step, after most of the carbonaceous materials has been
removed from the waste water, ammonia nitrification occurs in an aerated
system with the subsequent production of nitrites and nitrates.
The next step, denitrification, occurs in the absence of oxygen and is
responsible for converting nitrates to nitrogen and nitrogen oxides.
The reaction rate is increased by adding a biodegradable carbon source,
such as methanol. The wastewater from the second step is then
transferred to another aeration pond where the nitrogen and nitrogen
oxide gases are removed.
Over the range of operating temperatures, denitrification can maintain a
90 percent removal of total nitrogen. The optimum efficiency
temperature was found to be 30°C for most aerobic waste systems, with
efficiency drops at both higher and lower temperatures.
The system has been demonstrated on a pilot plant scale, but it is
premature to draw conclusions as to the effectiveness and reliability of
the nitrification-denitrification process in a full-scale operation.
Ozonation
If ozone is to be employed effectively and efficiently as a deodorant,
decolorant and disinfectant of drinking water, its physical and chemical
properties in water solution and their influence on pathogenic
microorganisms need to be known over the full range of possible
exposures.
Only in the absence of organic matter does ozone follow the laws of
ideal, i.e., nonreacting, gases in water. The distribution coefficient
of ozone between air and water, i.e., the ratio of the equilibrium
concentration of ozone in the liquid phase to that in the gas phase at
like temperature and pressure, is then about 0.6 at 0°C and 0.2 at 20°C.
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Increasing either the total pressure of the system or the partial
pressure of ozone in the air raises the concentration of ozone in water
in direct proportion of these pressures. In the presence of oxidizable
substances, their nature and concentration in water rather than the
distribution coefficient govern the amount of entering ozone.
As a disinfectant, ozone is said to possess an all-or-none property,
implying that it produces essentially no disinfection below a critical
concentration but substantially completes disinfection above that
concentration.
Because the absorption of ozone from the air into the water to be
disinfected is a matter of contact opportunity, contactcamber design
aims at a maximization of (1) effective interface, (2) driving force or
concentration of differential, and (3) time of exposure with due
consideration of advantages to be gained by countercurrent operation.
As a rule, capital and running cost of ozonation equipment cannot
compete with those of comparable chlorination equipment for the
treatment of a given water unless ozone is called upon and able to
remove objectionable odors and tastes and reduce the color of the water
more effectively than chlorine in combination with activated carbon and
coagulants. Ozone, also, leaves no residual, thereby becoming unable to
safeguard the treated water from future pathogenic contamination.
Reverse Osmosis
Osmotic pressure drives water molecules through a permeable membrane
from a dilute to a concentrated solution in search of equilibrium. This
natural response can be reversed by placing the salt water under
hydrostatic pressures higher than the osmotic pressure.
A good deal of experimentation has been carried out in an attempt to
apply membrane processes including reverse osmosis, ultrafiltration and
electrodialysis to the treatment of industrial wastes. Reverse osmosis
has the capability of removing dissolved and suspended materials of both
organic and inorganic nature from waste streams. However, organic-laden
streams tend to foul reverse osmosis membranes resulting in substan-
tially decreased throughput.
At present, none of these membrane processes appear to have direct
application to the treatment of the food processing wastes under
consideration here. These processes are relatively expensive when
applied to the large volumes of waste generated and the heavy solids
concentrations in food processing waste water. A primary problem is
that the rate of pure water production in reverse osmosis has been low,
and, thus, has not been economically acceptable.
Recent developments of the spiral or hollow tube reverse osmosis systems
permit large membrane areas to be incorporated into a small space, thus
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permitting large volumes of water to be treated. The use of either the
spiral or hollow tube system requires that all particles larger than 10
to 20 microns be removed from the waste stream before entering the
reverse osmosis system.
Another problem with this system is the bacterial growth on or near the
membrane and its damaging effect on the membrane.
Because chlorine damages the membranes presently available, the chlori-
nation of the water cannot occur before the reverse osmosis step.
Reverse osmosis units are, also, sensitive to both alkaline and high
temperature fluids. It is desirable to avoid both conditions if reverse
osmosis is to be used.
Solvent Extraction
This widely used process could theoretically be employed to extract
soluble organics from treatment wastes by employing a selective solvent.
Since the solvents, themselves, are likely to have solubilities in water
comparable to the concentration of the organics present, it is unlikely
that this process would have utility in food processing.
Ultrafiltration
Ultrafiltration uses a membrane process similar to reverse osmosis for
the removal of contaminants from water. Unlike reverse osmosis,
Ultrafiltration is not impeded by osmotic pressure and can be effected
at low pressure differences of 1.3-7.8 atmospheres (5-100 psi). The
molecular weight range of materials that might be removed by
Ultrafiltration is from 500 to 500,000. This would remove such
materials as some microorganisms, starches, gums, proteins and clays.
Ultrafiltration is finding applications in the food industry in sugar
purification, whey desalting, and fractionation. It can be used as a
substitute for thickeners, clarifiers and flocculation in waste water
treatment. In addition to removal of the above contaminants from waste
water, it can, also, be applied to sludge dewatering.
A.t the present time, because of high capital and operating costs, this
system has not found acceptance in the treatment of waste effluents.
ULTIMATE DISPOSAL METHODS
Percolation and Evaporation Lagoons
The liquid portion of cannery wastes can be "completely" treated and
discharged through percolation and evaporation lagoons. These ponds can
be sized according to the annual flow, so that the inflow plus the
incidentally added water are equal to the percolation and evaporation
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losses. There is, theoretically, no surface outflow in the usual sense.
Percolation and evaporation lagoons are subject to many of the problems
of ponds discussed previously.
The food processing and the biological solids grown in the pond are a
major operating problem. The soil interstices will eventually become
biologically sealed, causing percolation rates to be greatly diminished.
Unless remedial action is taken, the pond becomes largely an evaporation
lagoon. To prevent this, annual scarification and solids removal will
generally be required.
There are two major objections to percolation-evaporation ponds. The
first is that under almost any loading conditions the ponds may turn
septic, with odor problems resulting. Secondly, there is the potential
for long-range damage to aquifers, since objectionable and biologically
resistant organics may be carried into the groundwater by continuous
percolation.
Spray Irrigation
Spray irrigation is another method currently utilized by the food
industry for disposal of its wastes. The design of such systems is
rapidly becoming a highly scientific operation. Numerous cases of both
unsatisfactory results and trouble-free experience have been
encountered. Apparently such systems must be designed with a great deal
of flexibility to handle unforeseen problems. The hydraulic and organic
characteristics of the soil profile must be considered in the design as
well as the rates of waste degradation. The need to properly balance
nutrient loads to insure adequate microbiological activity and adequate
growth of plants without undue losses of nutrients to ground waters must
be considered. Other important design considerations include crop
management insuring proper crops and corp sequences and climatic
conditions considering evapotranspiration rates, precipitation and cold
weather operation.
Currently, a study is being conducted by the USDA to evaluate the
practice of land disposal of potato waste water. Several plants are
involved including PO-102, PO-114, PO-115, PO-116, PO-121, PO-122 and
PO-124. Their sizes range from 220 kkg/day (240 T/day) with water
usages from 8760-15510 1/kkg (2100-3720 gal/T) and BOD from 8.6-31.95
kg/kkg (17.2-63.9 Ib/T) .
The application rates being studied range from approximately 95-168
kilograms organic matter per hectar per day (85 to 150 pounds organic
matter per acre per day). Water applications will range from 9-37
thousand cubic meters per hectar per year (3 to 12 acre feet per acre
per year) for existing disposal sites. Nitrogen in waste water may
range from 50 to 125 ppm total N (much of it is organic), but through
decomposition and mineralization, it should be converted to nitrate.
The fields are planted with grass and other crops that can be harvested
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to remove some of the nitrogen, phosphorus and other plant nutrients.
To remove the excess nitrogen above plant growth requirements,
denitrification may be needed to minimize ground water pollution.
Further study will be done in this area.
Spray irrigation consists essentially of spraying the liquid waste on a
field at as high a rate and with as little accompanying nuisances or
difficulties of operation as possible. Pretreatment of waste water to
remove solids is suggested in order to prevent clogging of the spray
nozzles. This preliminary treatment in preparation for spray irrigation
has undoubtedly already reduced the BOD of the waste water.
Wastewater disseminated by spray irrigation percolates through the soil
and the organic matter in the waste undergoes a biological degradation.
The liquid in the waste stream is either stored in the soil or leached
to a groundwater. Approximately 10 percent of the waste flow will be
lost by evapotranspiration (the loss due to evaporation to the
atmosphere through the leaves of plants).
Spray irrigation presents an ideal method for disposal of liquid cannery
wastes when a combination of suitable features exists. These features
include:
1. A large area of relatively flat land available at an
economical price.
2. Proximity of the disposal area to the cannery.
3. Proper type of soil to promote optimum infiltration.
4. Absence of a groundwater underlying or nearby the dis-
posal area which is being or could be used as a public
water supply.
5. Absence of any suspended matter in the waste water of
such a nature so as to cause clogging of the spray
nozzles.
6. Maximum salt content in waste water of 0.15 percent.
7. Proper combination of climatic conditions conducive
to cover crop growth, percolation and evaporation,
i.e., sunny and relatively dry climate.
In actual practice, cannery wastes (after adequate screening) are
usually retained in a "surge tank" of sufficient volume to provide
continuous operation of sprays. The impounded screened waste is pumped
to a header pipe and a series of lateral aluminum or lightweight lines
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under ample pressure to provide each sprinkler with similar volumes of
waste for application to the land.
The amount of waste water reaching groundwater is variable quantity and
rather difficult to predict. In some cases it might be expected that no
usable groundwater would be involved. Considerable study seems to be
needed in evaluating this potential problem.
The following factors must be evaluated in designing a land disposal
system:
1. The site should be relatively level and well covered
with vegetation. A sloping site may be considered for
controlled runoff to a receiving water.
2. The soil should be light in texture and have a high
sand or gravel content. Some organic matter may be
beneficial, but high clay content is detrimental.
3. Spray testing and soil analyzing prior to full-scale
irrigation is recommended.
4. Soil cultivation should be practiced to prevent com-
paction.
5. Groundwater levels at the spray site should be at least
10 feet below the surface to allow for proper decomposi-
tion of the waste as well as more rapid percolation.
With the proper equipment and controlled application of the waste, spray
irrigation will completely prevent stream pollution, will not create
odor problems, and is usually less expensive than other methods of waste
disposal. The amount of land required may not, at present, be reliably
predetermined. Since a cover crop will provide 85-90 percent more soil
absorption, the type crop used is extremely important. A typical seed
mixture for cover crop is:
Mammoth clover 19X
Ladino-Alsac Mixture 25X
Alta-fescue 25%
Redtop 18%
Orchard grass 13%
This mixture is sowed at the rate of 16 pounds per acre to produce as
dense a cover crop as possible at the time of waste water application.
Different types of soils will give varying infiltration rates. It has
been shown from soil descriptions the permeability of each soil layer
has the following ranges of permeability.
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Soil Type
Trace fine sand
Trace silt
Little silt (coarse and fine)
Some fine silt
Little Clayey silt
Fissured clay-soils
Organic soils
Some clayey silt
Clay-soils dominating
Range of Coefficient of Permeability, K
m/min ft/min
0.3 - 0.06
0.24 - 0.012
0.0036 - 0.006
0.00024 - 0.00012
1.0 - 0.2
0.8 - 0.04
0.012 - 0.002
0.0008 - 0.0004
0.00006 and lower
0.00002 and lower
Thus, trace fine sand would be more suitable for spray or flood
irrigation than clay soils because of higher rates of permeability.
There are, of course, other factors which must be considered.
Many of the more recently constructed ultimate disposal systems consists
of a combination of lagoons and land disposal. In this type of system
large lagoons (ponds) having retention times of 30 days or more are
constructed to receive the waste effluents. If odor becomes a problem
because of location, then sufficient aeration equipment is provided to
reduce or eliminate the odor. The waste effluent is removed from the
pond or lagoon and directed to spray irrigation.
Soil fertility, crop production, and soil conservation considerations
must, of necessity, be used as an ultimate basis for regulating land-
spreading operations if the system is to remain continuously effective.
Wet Oxidation
The development and continuing perfection of oxidation methods for waste
sludges and slurries that produce oxidized residues has been one of the
major breakthroughs in waste treatment practice. Such residues are not
putrescible and the processes produce little air pollution. The
processes require thickening as pretreatment and greater concentrating.
Furthermore, the process oxidation takes place in the presence of liquid
water at 400-600°F and usually at high pressures of 18-103 atm (250-
1,500 psi). The process may be operated on a continuous or batch basis
and solids volume is greatly reduced and putrescibility nonexistent.
The current accepted practice in the food processing industry is to
separate the solids from the waste effluent streams for use as cattle
feed and in this manner receive some economic benefit. However, if a
Ss.c 0x3 -X _ion system for wasi - disposal of solids is used, then it would
be desirable to leave as many of the organic solids in the effluent as
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possible. This waste effluent is oxidized and then separated into two
waste effluent streams, one which is clean water (condensation) and the
second high in oxidized solids. It is this reason that has restricted
or prevented the application of this process to the food processing
industry.
Wet oxidation reduces the COD by about 80 percent to less than 20 mg/1,
and 90 percent of the volatile solids are removed. The effluent liquor
has a BOD between 5,000 and 9,000 mg/1. The residual solids can be
dewatered by vacuum filtration or disposed of in lagoons or drying beds.
Fungal Digestion
A considerable amount of work has been done on the use of fungi in the
continuous oxidation of food processing wastes. Fungi Imperfect! can
convert organic matter into a mycelium with a sufficiently high protein
content for use as an animal feed supplement. The work that has been
done involves principally wastes from corn and pea processing
operations. However, consideration has been given to applying the
process to other food industry wastes. While fungal digestion cannot
presently be considered as a fully proven process, its further develop-
ment could result in a significant new process approach for treating
cannery wastes with the production of a by-product with economic value.
There is one drawback existing in the development of this system, which
is the difficulty to harvest the finer mycelium. Therefore, more study
is needed to be done in this area in order to reduce this cost of
separation. New materials of construction which permit the construction
of more durable and finer mesh screen cloths will make this separation
economically feasible in the near future.
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SECTION VIII
COST, ENERGY, AND OTHER NON-WATER QUALITY ASPECTS
INTRODUCTION
This section will discuss and summarize the cost of treatment and
control technologies described in Section VII and will estimate the cost
incurred in applying various combinations and/or permutation of
pollution control technologies to achieve best practicable and best
available effluent reductions. The sequence of treatment components is
given in Table 27 for each effluent reduction level for each of the five
subcategories. Best practicable effluent reduction is attainable
through the application of secondary biological treatment (Levels B or
E) or land treatment (Level D) . Best available effluent reduction is
attainable through the application of additional biological or advanced
treatment (Level C or F or G). The subsequent analysis will also
describe energy requirements and the non- water quality aspects
(including sludge disposal) of the levels of technology.
The information presented in Sections VII and VIII provide the
background for the rationale supporting the effluent guidelines
presented in Sections IX, X and XI.
IN-PLANT CONTROL COSTS
Raw Material Cleaning
One possibility for reducing processing plant waste loads is to do the
raw material cleaning in the field.
In the case of apples and potatoes, this is not a practical approach
because most of the harvest goes into storage prior to processing.
In the case of citrus, it is practical to consider field washing of the
fruit when it is picked. The presently used washing equipment could be
assembled in a portable module along with a recirculated wash water
system. The fruit would be washed as it is loaded into the trucks for
transportation to the processing plant.
Since there is only a small waste load generated in washing good quality
fruit, the only real benefit which would be derived from cleaning in the
field is a reduction in the volume of water used by the citrus
processor, and, thus, there would be a smaller quantity of water to
treat or dispose of by land irrigation.
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The equipment cost for field washing would be equal to or greater than
that already installed in the processing plant for washing as it is
received.
Thus, the requirement of field washing citrus is rejected for the
following reasons:
1. The processor would not have close control of
the washing/cleaning procedure.
2. There would be no cost benefit to the processor.
The cost of field washing would offset the cost of
treating the additional quantities of wash water at the
processing plant.
3. The processor presently has available water from
other processing areas available for fruit washing.
Peel Removal
The peel is normally removed from apples by the use of mechanical knives
which can be adjusted to remove the desired amount of imperfections.
Mechanical peeling has a high labor cost and creates a large cleanup of
solid wastes which adhere to equipment surfaces and spill onto the
floor. While it is hoped these solids will be collected and processed
into additional products, no change from mechanical peeling is
recommended.
Citrus segment processing employs only mechanical peeling. The peeled
fruit is treated with caustic to remove rag and segment membranes. No
change is recommended.
Potatoes are treated with steam, wet lye or dry caustic systems prior to
peel removal. In Section IV processing plant effluent differences
attributable to peeler system were negligable. However, if water sprays
are used to remove the peel after treatment, the waste effluent load
must be higher than if water sprays are not used.
If the treated peel is removed by rubber abrading and brushing with
added water, this waste load does not enter the waste effluent from the
plant. Information from vendors indicates that a rubber abrading
installation might achieve approximately a 25 per cent reduction in
water usage, a 40 per cent reduction in BOD5, and a 65 per cent
reduction in suspended solids.
Therefore, it is recommended (but not required) that the water spray
system for the removal of treated peelings be replaced with the rubber
abrading system with minimal water usage for brushing.
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Capital costs for an installation in a 589.6 kkg/day (650 ton/day)
potato processing plant are estimated to be $120,000 while annual
operating cost is estimated to be $12,000.
Sorting, Trimming and Slicing
Sorting, trimming and slicing generate wastes for all three commodities
that are directly attributed to the cutting of the fruit or vegetable.
For example, the larger the percentage of blemishes to be removed, the
greater the amount of cutting, and the higher the BOD5 load released
(excluding the blemish). Some water volumes can be reduced, but this
will not reflect in a reduction in the total waste load, but will
produce a more concentrated waste effluent.
There are no in-plant changes which could appreciably reduce waste loads
in sorting, trimming and slicing, with the exception of potato
processing, where raw starch could be recovered as a concentrated slurry
by the use of hydroclcnes. This application is experimental and its
practicability may depend on the value of the recovered starch.
Transport
Replacement of water transport systems with mechanical conveyors is
recommended except where the water is, also, serving some other function
such as washing or cooling the product. It is difficult to estimate
this replacement cost since the size of the processing plants as well as
the amount of conveying within each plant varies widely. Each
processing plant may have to be evaluated separately.
Blanching
Apple slices are blanched two to six minutes at82C (180 F) prior to
canning. Steam blanching is preferred to water blanching resulting in
the use of reduced quantities of water. Hot-water blanching of potatoes
is preferred because of the large amount of leachables which must be
removed during this process step. Steam or experimental hot-gas
blanching does not have the ability to remove large quantities of
solubles from the product.
No blanching is used in citrus processing.
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Cleanup
Cleanup is one of the largest uses of water for all three commodities.
This usage may be reduced considerably by adopting the good management
practices previously listed.
The capital cost of adopting this practice is nominal. Operating costs
should not increase significantly, since the added labor cost, if any,
would be largely offset by a reduction in water cost and treatment
costs.
In-Plant Reuse of Water
The reuse of water within a food processing plant may be put into one of
two categories: (1) water which comes in direct contact with the fruit
or vegetable and (2) water which contacts the product in an indirect
manner.
Conservation of water which is in direct contact with
theproductcan be effected by imposition of a counter flow system. For
example, the water that is used to cool the product after blanching
might be sequentially used in the blanching step and then possibly in
the washing/ cleaning step. It has been estimated that one-third less
water is used in a counter flow system than in a recirculation system
where the water is recirculated within a given portion of the process.
There is, also, less danger of bacteria growth in a once-through counter
flow system than a recirculation system.
Indirect Contact; Some typical uses of water which does not contact the
product directly are can cooling, barometric condenser, heat exchangers,
refrigeration system, etc. All of these cooling systems can use a lower
quality water than that which contacts the fruit or vegetable and, since
this cooling water normally has a low BOD content, it is more amenable
to recirculation and reuse. Cooling towers or ponds are generally
employed for removal of heat in the recirculation of water.
The citrus industry is the largest user of cooling water and therefore
offers the greatest potential for water savings. Very little process
water comes in direct contact with the fruit (fruit washing and segment
rinsing) . Thus, the major portion of the water (cooling water) in a
citrus plant could be reused with the addition of either cooling towers
or ponds. It is, therefore, recommended that cooling towers or ponds be
utilized to recirculate cooling waters. Capital costs for cooling
towers for a 3630 kkg/day (4000 ton/day) plant are estimated from plant
CI-135 to be $75,000 and annual operating costs are estimated to be
$7,500. These costs are based on actual industry cooling tower
construction costs in 1971 dollars based on typical small and large
citrus plants.
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Each processing plant, whether it is apples, citrus or potatoes, must
make its own economic assessment on in-plant water reuse. Since most
plants have wide variation in their processing methods and plant
layouts, each reuse of water must be evaluated on the following factors:
1. Cost of in-plant treatment.
2. Cost of fresh water.
3. The effect of reused water on product quality.
WASTE EFFLUENT TREATMENT AND CONTROL COSTS
This section develops capital costs and operating costs for six (Levels
B-G) levels of waste effluent treatment for both large and small typical
plants within each of the five subcategori.es. In addition, we have
estimated that total U.S. investment required to meet each of these six
levels of treatment for each of the five subcategories as well as the
pertinent apple, citrus, and potato segment of the canned and preserved
fruits and vegetables industry.
Effectiveness of Waste Treatment Systems
Table 26 presents typical waste load reductions that may be expected by
the application of various treatment systems to organic wastes. The
systems include those that we have previously classified in Section VII
as preliminary, primary, biological (secondary), advanced and ultimate.
Parameters for Cost Estimating
The raw water usage and raw waste loading used as the basis for
estimating costs are those listed as average industry practice for each
of five subcategories as previously set forth in Section V (Tables 19 -
21). Plants in each of the subcategories have been segmented into two
groups represented by a typical small plant or by a typical large plant.
The typical small plants are 91 kkg/day (100 ton/day) for both apple
subcategories, 180 kkg/day (200 ton/day) for dehydrated potato products,
and 360 kkg/day (400 ton/day) for citrus and frozen potato products.
The typical large plants are 450 kkg/day (500 ton/day) for apple juice
only, 540 kkg/day (600 ton/day) for dehydrated potato products, 910
kkg/day (1000 ton/day) for apple products except apple juice and frozen
potato products, and 3630 kkg/day (4000 ton/day) for citrus products.
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TABLE 26
EFFECTIVENESS AND APPLICATION OF WASTE TREATMENT SYSTEMS
Treatment System
Flotation
Flotation with pH
control & Flocculants
added
Sedimentation
Aerated Lagoons
Aerobic Lagoons
Shallow Lagoons
Trickling Filter
Anaerobic & Aerobic
Lagoons
Anaerobic, Aerated, &
Aerobic Lagoons
Anaerobic Contact
Process
Activated Sludge
Extended Aeration
Chlorination
Sand Filter
Microscreen
Electrodialysis
Ion Exchange
Carbon Adsorption
Chemical Precipitation
Reverse Osmosis
Spray Irrigation
Flood Irrigation
Ponding & Evaporation
Application
Preliminary
Preliminary
Primary
Biological
Biological
Biological
Biological
Biological
Biological
Biological
Biological
Biological
Advanced
Advanced
Advanced
Advanced
Advanced
Advanced
Advanced
Advanced
Ultimate
Ultimate
Ultimate
Waste Load Reduction
BOD 30% Removal
SS 80% Removal
BOD 30% Removal
SS 80% Removal
BOD 50 to 80% Removal
BOD 50 to 99% Removal
BOD 50 to 99% Removal
BOD 50 to 99% Removal
BOD 70 to 90% Removal
BOD 95% Removal
BOD 99% Removal
BOD 90 to 95% Removal
BOD 90 to 95% Removal
BOD 90 to 95% Removal
Disinfectant
BOD to 5-10 mg/1
SS to 3-8 mg/1
BOD to 10-20 mg/1
SS to 10-15 mg/1
Total Dissolved Solids
90% Removal
Salt 90% Removal
BOD to 98% as Colloidal
Organic
Phosphorus 85-95% Removal
Salt to 5 mg/1
TDS to 20 mg/1
Complete
Complete
Complete
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Levels of Treatment Technology
For the purpose of determining the cost effectiveness of various levels
of treatment it was necessary to select practical treatment systems to
achieve these levels. The system design used to obtain a given level of
treatment varies from subcategory to subcategory and there are numerous
combinations of treatment steps that will achieve the same level of
treatment. In general the treatment systems consist of one or more of
the following five classes of treatment technology: preliminary,
primary, secondary, advanced, and ultimate disposal.
Preliminary Treatment; Screens are preliminary treatment and are used
to remove solids from the waste effluent streams as they are discharged
from the processing plant. The screening of the waste effluent stream
from a food processing plant is normally the first step in the treatment
system and is the most economical method of removing large solids. This
removal of solids protects other equipment from plugging or damage and
reduces the size of other solids handling units. There are various
types of screens which are used in these plants. The vibrating screen
equipped with a 20 to UO mesh screen cloth is generally used. In recent
years because more municipal sewer assessments are based on the amount
of suspended solids in the effluent and, also, because of increased
emphasis on reuse of process water, there has been a concerted effort on
the part of the food processor to use finer and finer mesh screens.
Primary, treatment: Primary treatment is, also, used to remove solids
from the waste effluent streams. Primary treatment includes
sedimentation units with and without sludge disposal to remove
settleable solids not removed in the preliminary screening. A clarifier
of either circular or rectangular design is used for the removal of
floatable and settleable solids. These clarifiers are equipped with
mechanical scrapers to assist in the removal of solids that settle to
the bottom or float on the top. The volume of solids that is removed
from the clarifier is further concentrated by a rotary vacuum filter or
a centrifuge. The concentrated solids can, usually, be sold as animal
feed. Design criteria for estimating cost of primary systems for each
typical size of each subcategory are primarily waste water flow and
suspended solids loading (See Tables 19-21).
Primary treatment is not, generally, used in the apple or citrus
industry. If a primary treatment system is present at an apple or
citrus plant, it is, usually, designed without sludge disposal. In the
potato processing industry, primary treatment with clarifier sludge
concentration is necessary and practicable because of the high suspended
solids loading. It is common practice in the potato industry to utilize
dual primary clarifiers. One clarifier, is used to recover solids from
the process waste water, Another clarifier is used to settle silt and
remove mud from the raw potato wash water. The process waste water
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solids are collected and concentrated by a rotary vacuum filter. In the
cost figures given in Table 28, dual clarifiers and a rotary vacuum
filter are included in the sedimentation with sludge recovery cost
estimates for both frozen and dehydrated potato plants.
Secondary (Biologica1} Treatment; Biological treatment is a secondary
treatment system which is employed for a high reduction of BOD from the
waste effluent stream. To achieve this high reduction in BOD a number
of different biological systems may be employed: biological filters,
activated sludge, aerated lagoons, anaerobic lagoons, and shallow
lagoons.
Biological treatment systems are best practicable technology and
multiple combinations of biological treatment systems are best available
technology. The design parameters for these treatment systems are
primarily total waste water flow and BOD loading (See Tables 19-21).
The estimation of cost for each typical system size in each subcategory
are based on these criteria.
Sand filtration, carbon adsorption, microsGreening, ion exchange,
electrodialysis, reverse osmosis and ultra filtration have been
considered for the further reduction in BOD and the removal of
undesirable soluble components from the waste stream to permit water
recycle or reuse. The advanced treatment was considered as an
additional component to the best practicable biological treatment system
to attain best available effluent reduction.
Ultimate Disposal: For the zero discharge of pollutants, land disposal
is a technology currently being used by apple, citrus and potato
processors when sufficient and suitable land is available. Both land
flooding and spray irrigation are accepted methods of disposal and have
been used as the basis of cost estimates. The primary design parameter
for irrigation systems is waste water flow (See Tables 19-21).
Evaporative ponds and percolation lagoons are, also, an accepted form of
ultimate disposal but have not been used in ultimate disposal cost
estimates.
Effluent Reduction Levels
The classes of waste treatment systems discussed above are suitable
waste treatment systems which will perform when properly operated within
the design parameters and limitations of the system for apple, citrus,
or potato processing wastes. Best practicable effluent reduction is
attainable through the application of secondary biological treatment
(Levels B or E) or through ultimate disposal by land treatment (Level
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D) . Best available effluent, reduction is attainable through the
application of advanced treatment (Levels C or P or G).
All apple, citrus, and potato subcategories regardless of waste
treatment or disposal method utilize screens to remove particulate
solids from the waste effluent as it leaves the plant. The higher the
percentage of solids which are removed at this point the lower the waste
load entering the treatment system. Screening is Level A effluent
reduction for each typical size in each subcategory. Screening is also
used in all other effluent reduction levels (Levels B - G).
Primary treatment is not used as universally as screening. Only in the
case of the two potato subcategories is it necessary to employ primary
sedimentation with sludge disposal prior to any biological treatment
system or prior to land treatment. Dual primary clarifiers and a rotary
vacuum filter are in the potato sedimentation with sludge disposal cost
estimates. Thus, reduction levels B through G for frozen and dehydrated
potato products utilize primary sedimentation.
As discussed earlier in the section under "In-Plant Reuse of Water"
cooling towers or ponds are very important in handling the large cooling
water volumes in the citrus industry. Thus, effluent reduction levels B
and C and E through G for the citrus processing subcategory utilize
cooling towers.
There are several different biological systems used to fully or
partially achieve effluent levels B and C and E through G. Some
biological treatment systems are dependent upon long retention times to
achieve the desired waste load reduction; some are not. Large land
areas may be required to accommodate some of these systems but only
limited area requirements are needed if mechanical separation or
collection devices such as centrifuges and filters are utilized. Higher
energy, maintenance, and capital costs are required with mechanical
equipment to attain comparable levels of waste reduction. Aerated
lagoons with and without settling, aerobic/anaerobic lagoons, and 30 day
shallow lagoons are biological systems used to attain Levels B and C
effluent reduction.
Effluent levels E, F and G utilize activated sludge (secondary)
treatment. Level G, also, employs an aerated lagoon. Effluent levels F
and G utilize advanced treatment technology in the form of sand
filtration following secondary treatment. This polishing filter removes
most of the remaining BOD and suspended solids. Very low effluent
levels are possible.
Level D reduction is attained through the use of screening, primary
sedimentation (potato only), and a shallow lagoon before ultimate
disposal through land treatment. Spray or flood irrigation is the form
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of land treatment used. The availability of suitable and sufficient
land are limits to the utilization of this technology.
The six effluent reduction levels for each subcategory are described in
detail in Table 27 by listing the sequence of waste effluent treatment
technologies utilized to attain each level of effluent reduction. For
example, effluent reduction Level B for the apple juice subcategory is
attained through preliminary screening followed by two aerated lagoons
(no settling) in series.
Investment and Annual Operating Costs - Model Plant
The estimated investment to obtain the various treatment levels is shown
for both small and large plants for each of the five subcategories in
Tables 30-34. These costs are generated from Tables 28 and 29 which
list investment and annual cost for various preliminary, primary,
secondary, advanced and ultimate treatment systems for small and large
plants. The annual operating costs corresponding to the investment
costs are also shown in these tables. Investment costs for specific
waste treatment systems are dependent on the waste water flow, BOD
loading and suspended solids loading. The investment costs were
calculated on the basis of raw waste effluent data from Tables 19-21
with information supplied, from food processing equipment manufacturers,
engineering contractors and consultants. Costs compare satisfactorily
with investment costs collected individually from apple, citrus and
potato processors. All costs are reported in August 1971 dollars.
Percentage factors were added to the basic system estimate for design
and engineering (105?) and for contingencies and omissions (15%). Land
costs were estimated to be $4940 per hectare ($2000 per acre).
Variations exist in plant water flows and BOD5 loadings; there exist
inherent inaccuracies in cost estimating which could reflect an error
approaching 20 to 25 percent.
The components of annual cost include capital cost, depreciation,
operation and maintenance costs, and energy and power costs. The
capital interest costs are assumed to be 8 percent, depreciation costs
are assumed to be 5 percent and taxes and insurance are assumed to be 3
percent of the investment.
Investment and Annual Operating Costs - Subcategory
The total investment costs for each alternative treatment level is
calculated for each of the five subcategories in Table 35. The
investment cost are given for both typical small plants and typical
large plants. The total annual costs for small and large plants in each
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subcategory are included in the tabulation. Also, each treatment level
includes screening (Level A) .
The total investment (or total annual) costs are calculated by
multiplying the treatment level's capital cost ($1000) times the annual
raw material processed by the subcategory typical plant (million kkg
(ton) / year) and by dividing by the capacity (kkg (ton)/ day) and by
the processing season (day/year) . There are assumptions with regard to
season and annual raw material processed. The season for apples is
assumed to be 50 days/year, 216 days/year for citrus, and 240 days/ year
for potatoes. With regard to the annual raw material processed, 0.36
and 1.09 million kkg (0.4 and 1.2 million tons) of the annual apple crop
are assumed to be processed to apple juice and apple products except
juice respectively. The 6.4 million ton potato crop is assumed to be
processed equally into frozen and dehydrated products. This assumption
is possible because the model plants processing frozen products are
almost twice as large as the dehydrated potato model plants. A further
assumption is that annual raw material is processed equally by the
typical small plant and by the typical large plant within each
subcategory. In this rationale, economic impacts for both small plants
and large plants are thereby considered.
The total investment costs for achieving each level of effluent
reduction are listed for each subcategory and each industry in Table 36.
The total annual costs are listed in Table 37. The total investment and
annual costs from Table 35 are summed to calculate these total costs for
Tables 36 and 37. The assumptions are that_all plants are subject to
each treatment level and that no present treatment facilities exist.
The cost impact on the apple, citrus, and potato industry as a result of
applying each level of effluent reduction is given in Table 38. Two
assumptions have been made to develop this table. First, all plants are
not subject to each level of effluent reduction. For each commodity, a
percentage of the industry was found to be disposing of their waste to
municipal systems, a percentage through land treatment and a percentage
by secondary treatment techniques. The results of our apple, citrus and
potato processing survey are indicated below:
Municipal Secondary Land
Industry Treatment Treatment Treatment
Apple 26 20 54
Citrus 12 32 56
Potato 10 33 57
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These secondary treatment factors are applied to effluent reduction
Levels B, C, E, F and G. The land treatment factors are applied to
Level D. The municipal treatment factors are not applied because these
plants are outside the scope of this effort.
The second assumption is that treatment facilities do exist and that
only a portion of the industry subject to an effluent reduction level
will have to either construct facilities or upgrade existing facilities.
It was assumed that one-third of the industry would need to construct or
upgrade facilities to achieve Levels B, D, and E and ninty-nine percent
of the industry would need to construct additional facilities to achieve
Levels C, F and G. These factors are applied to the capital costs in
Table 36.
The result of Table 38 is that the capital investments for each
subcategory can be related to each level of effluent reduction. Levels
B and E are the effluent reduction attainable through the application of
best practicable control technology currently available. Levels C, F
and G are the effluent reductions attainable through the application of
the best available control technology economically achievable. Table 39
is a tabulation of the total annual costs for each subcategory to meet
each level of effluent reduction.
The investment costs of meeting Levels B and D by 1977 are $2.2 million
for apples, $6.2 million for citrus and $8.68 million for potatoes for a
total industry cost of $17.1 million. The investment cost of meeting
similar levels of effluent reduction through application of more
expensive treatment technology represented by Levels E and D by 1977 are
$4.7 million for apples, $10.0 million for citrus, and $11.4 million for
potatoes for a total industry cost of $26.10 million. The investment
costs of meeting Levels B, C, and D by 1983 are $3.7 million for apples,
$12.0 million for citrus, and $13.4 million for potatoes for a total
industry cost of $29 million. The investment cost of meeting similar
levels of effluent reduction through application of more expensive
treatment technology represented by Levels E, F or G, and D by 1983 are
$6.1 or $ 6.7 million for apples, $12.3 or $14.1 million for citrus, and
$13.5 or $15.1 million for potatoes for a total industry cost of $32 or
$36 million.
Therefore, the total industry (apple, citrus, and potato) investment
costs to meet 1977 levels of effluent reduction range from $17.1 to
$26. 1 million and the total industry costs to meet 1977 and 1983 levels
of effluent reduction range from $29 to $36 million.
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TABLE 27
EFFLUENT TREATMENT SEQUENCE BY SUBCATEGORY TO ACHIEVE VARIOUS LEVELS OF EFFLUENT REDUCTION
APPLE JUICE
APPLE PRODUCTS CITRUS PRODUCTS DEHYDRATED FROZEN
(EXCEPT JUICE) POTATO PRODUCTS POTATO PRODUCTS
E.
V
0
I
A
R
R
N
R
N
ATMENT COMPONENT LEVEL LEVEL
(SEQUENTIAL) BCDEFG BCDEFG
EL A SCREENING 111111 111111
LING TOWER
MARY SEDIMENTATION
EROBIC/AEROBIC LAGOON
ATED LAGOON (SETTLING) 2 2
ATED LAGOON
0 SETTLING) 23 23
ATED LAGOON
0 SETTLING) 34 34
ALLOW LAGOON
30 day retention) 2 52
LEVEL
BCDEFG
111111
222222
3
3 4
4 5
6 3
LEVEL
BCDEFG
222222
3 3
4 4
5
6
7 3
LEVEL
B C D E
1111
2222
3 3
4 4
5
6
7 3
F G
1 1
2 2
ACTIVATED SLUDGE
AERATED LAGOON
(NO SETTLING)
SAND FILTRATION
SPRAY IRRIGATION
222
3
3 4
222
3
3 4
333
4
4 5
333
4
4 5
333
4
4 5
-------
TABLE 28
INVESTMENT AND ANNUAL COSTS
PRELI MINARY, PRIMARY & BIOLOGICAL WASTE TREATMENT SYSTEMS
WASTE TREATMENT
SYSTEM
Prel inn nary
- Screen
Pri mary
- Sedimentation w/
Sludge Disposal
- Sedimentation w/out
Sludge Disposal
Biologi cal
- Shallow Lagoon w/
30-Day Retention
- Shal 1 ow Lagoon w/
90-Day Retention
- Aerated Lagoon
w/Settl i ng
- Aerated Lagoon
w/out Settling
- Anaerobic/Aerobic
Pondi ng
- Trickling Filter
- Acti vated SI udge
- Spray Irrigation
w/Runoff
Prel i mi nary
- Screen
Pri mary
- Sedimentation w/
Sludge Disposal
- Sedimentation w/out
Sludge Disposal
Biological
- Shal low Lagoon w/
30-Day Retention
- Shallow Lagoon w/
90-day Retention
- Aerated Lagoon
w/Settl i ng
- Aerated Lagoon
w/out Settling
- Anaerobic/Aerobic
Ponding
- Trickling Filter
- Acti vated SI udge
- Spray Irrigation
w/ Runoff
APPLE
PRODUCTS
($1,000)
CAPITAL ANNUAL
2.0
48.0
25.0
15.0
50.0
27.0
15.0
70.0
130.0
240.0
25.0
5.2
150.0
70.0
50.0
105.0
93.0
65.0
160.0
540.0
595.0
100.0
1 .0
7.2
3.0
2.0
7.0
9.2
5.4
17.0
4.0
8.5
12.0
2.8
22.5
12.5
6.5
13.0
19.8
15.8
34.0
23.0
30.5
28.0
SMALL PLANTS
APPLE
JUICE
($1,000)
CAPITAL ANNUAL
1.0
50.0
10.0
10.0
19.0
10.0
6.0
16.0
250.0
151 .0
14.0
LARGE
2.2
62.0
24.0
15.0
45.0
34.0
22.0
50.0
170.0
270.0
320.0
.3
4.5
1 .5
1.0
6.3
5.8
2.0
.32
3.0
5.0
7.5
PLANTS
.8
9.3
3.9
2.5
7.0
11 .2
6.6
11 .0
6.0
11 .0
13.5
CITRUS
JUICE, OIL.SEG.
& PEEL PRODUCTS
($1,000)
CAPITAL ANNUAL
6.2
190.0
92.0
63.0
126.0
114.0
81 .0
212.0
680.0
725.0
144.0
19.2
678.4
384.0
240.0
492.8
504.0
352.0
787.2
3,024.0
2,960.0
758.4
140
3.5
28.0
15.9
8.0
15.0
22.8
18.4
44.8
30.0
39.0
33.5
12.8
121 .9
72.0
28.0
46.7
76.2
54.7
142.1
132.8
174.4
86.4
POTATOES
DEHYDRATED
($1,000)
CAPITAL ANNUAL
3.3
95.0
44.0
30.0
75.0
60.0
40.0
115.0
300.0
400.0
55.0
6.9
200.0
103.0
72.0
142.0
130.0
92.0
250.0
780 .0
805.0
168.0
1 .6
14.0
7.5
3.8
10.5
14.0
11 .0
20.0
13.0
17.0
20.0
4.0
32.0
18.0
9.0
16.3
25.0
20.0
52.0
35.0
44.0
37.0
POTATOES
FROZEN
($1,000)
CAPITAL ANNUAL
6
176
90
63
125
113
80
210
670
720
140
11
345
195
124
243
245
175
450
1 ,480
1 ,470
359
.2
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
3.5
27.5
16.5
7.8
15.0
22.2
18.0
44.0
30.0
36.0
33.0
6.7
60.0
35.5
14.7
24.5
39.2
35.0
83.0
67.0
85.0
49.0
-------
TABLE 29
INVESTMENT AND ANNUAL COSTS
ADVANCED WASTE TREATMENT SYSTEMS & ULTIMATE DISPOSAL
WASTE TREATMENT
SYSTEM
Chlori nati on
Chemical Secondary
Treatment
Sand Filtration
Mi croscreeni ng
Nitrogen Removal
Activated Carbon
Ultrafiltration
Ultimate Disposal
fiased on Flow)
(Based on BOD5)
Chlori nati on
Chemical Secondary
Treatment
Sand Filtration
Mi cros creeni ng
Nitrogen Removal
Activated Carbon
Ultrafiltration
Ultimate Disposal
(Based on Flow)
(Based on BOD5)
APPLE
PRODUCTS
($1,000)
CAPITAL ANNUAL
2
100
38
11
38
72
200
32
11
.6
.0
.0
.0
.0
.0
.0
.0
.2
.41
22.5
7.9
3.1
3.3
3.6
51.0
8.0
2,8
SMALL PLANTS
APPLE
JUICE
($1,000)
CAPITAL ANNUAL
1 .3
40.0
24.0
6.0
22.0
36.0
110.0
15.0
2.8
.24
11.0
5.8
1.7
1.3
1.7
34.0 1
3.8
0.7
CITRUS
JUICE, OIL.SEG. POTATOES POTATOES
& PEEL PRODUCTS .DEHYDRATED FROZEN
($1,000) ($1,000) ($1,000)
CAPITAL ANNUAL CAPITAL ANNUAL CAPITAL ANNUAL
13.95
675.0
111.1
69.5
112.0
420.0
,060.0
242.3
76.8
2.5
107.0
15.3
15.8
15.3
22.5
207.0
60.6
19.2
5.8
260.0
61 .0
26.5
60.0
175.0
440.0
88.8
21 .5
.95
49.0
10.1
7.0
7.0
9.0
100.0
22.2
5.4
13
620
107
65
105
410
995
223
65
.0
.0
.0
.0
.0
.0
.0
.9
.3
2.3
98.0
14.9
14.9
14.75
21.5
195.0
56.0
16.3
LARGE PLANTS
10
500
92
52
93
330
800
144
144
.5
.0
.5
.0
.0
.0
.0
.0
.0
1 .8
83.0
13.5
12.5
12.5
17.0
165.0
36.0
36.0
5.5
250.0
62.5
27.0
60.0
180.0
450.0
75.2
14.2
1.0
48.0 3
10.25
7.0
7.0
9.0 1
100.0 5
18.8 1
2.0
64.8
,328.0
419.2
244.8
438.4
,408.0
,088.0
,508.3
768.0
11.52
448.0
46.7
40.8
40.8
84.0
896.0
377.1
192.0
15.0
750.0
120.0
78.0
121 .0
480.0
1 ,180.0
276.2
71 .7
2.7
113.0
16.2
17.0
17.0
26.0
230.0
69.1
17.9
31
1 ,580
212
140
220
820
2,450
660
163
.0
.0
.0
.0
.0
.0
.0
.3
.5
5.9
217.5
24.5
24.75
24.75
47.0
445.0
165.1
40.9
141
-------
TABLE 30
INVESTMENT AND ANNUAL COSTS BY EFFLUENT REDUCTION LEVEL FOR APPLE JUICE (Sole Product)
SUBCATEGORY FOR TYPICAL SMALL PLANT (100 TPD) AND LARGE PLANT (500 TPD)
TREATMENT COMPONENT
LEVEL A: SCREENING
PRIMARY SEDIMENTATION
SHALLOW LAGOON
(30 day retention)
AERATED LAGOON
(Settling)
AERATED LAGOON
(No Settling)
ANAEROBIC/AEROBIC LAGOON
ACTIVATED SLUDGE
SAND FILTRATION
SPRAY IRRIGATION
COST OF EFFLUENT REDUCTION ALTERNATIVE ($1,000)
LEVEL B LEVEL C LEVEL D LEVEL E
LEVEL F
LEVEL G
Smal1 Large Smal1 Large Srnal1 Large Smal1 Large Sinai 1 Large Smal1 Large
1.0 2.2 1.0 2.2 1.0 2.2 1.0 2.2 1.0 2.2 1.0 2.2
10.0 15.0
10.0 34.0
12.0 44.0 12.0 44.0
151.0 270.0
151.0 270.0
24.0 62.5
6.0 22.0
151.0 270.0
24.0 62.5
15.0 75.2
TOTAL CAPITAL INVESTMENT
($1000)
TOTAL ANNUAL COST ($1000)
13.0 46.2 23.0 80.2 26.0 92.4 152.0 272.2
4.3 14.0 10.0 25.2 5.1 22.1 5.3 11.8
176.0 334.7 182.0 356.7
11.1 22.05 13.1 28.$
-------
TABLE 31
INVESTMENT AND ANNUAL COSTS BY EFFLUENT REDUCTION LEVEL FOR APPLE PRODUCTS EXCEPT JUICE (ONLY)
SUBCATEGORY FOR TYPICAL SMALL PLANT (100 TPD) AND LARGE PLANT (1,000 TPD)
TREATMENT COMPONENT
LEVEL A: SCREENING
PRIMARY SEDIMENTATION
SHALLOW LAGOON
(30 day retention)
AERATED LAGOON
(Settling)
AERATED LAGOON
(No Settling)
ANAEROBIC/AEROBIC LAGOON
ACTIVATED SLUDGE
SAND FILTRATION
SPRAY IRRIGATION
LEVEL B
Smal1 Large
2.0 5.2
30.0 130.0
COST OF EFFLUENT REDUCTION ALTERNATIVE ($1,000)
LEVEL C LEVEL D LEVEL E LEVEL F
LEVEL G
Smal1 Large Smal1 Large Smal1 Large Smal1 Large Smal1 Large
5.2
2.0
15.0
27.0
50.0
93.0
30.0 130.0
2.0
5.2
2.0
5.2
2.0
5.2
2.0
5.2
15.0 50.0
240.0 595.0 240.0 595.0
38.0 92.5
15.0 65.0
240.0 595.0
38.0 92.5
32.0 144.0
TOTAL CAPITAL INVESTMENT 32.0 135.2
($1,000)
TOTAL ANNUAL COST (-$1,'000) 11 .-8 34-4
74.0 278.2 49.0 199.2 242.0 600.2 280.0 692.7 295.0 757.7
42.2 60.7 11.0 45.3 9.5 33.3 17.4 46.8 22.8 79.2
-------
TABLE 32
INVESTMENT AND ANNUAL COSTS BY EFFLUENT REDUCTION LEVEL FOR CITRUS PRODUCTS
SUBCATEGORY FOR TYPICAL SMALL PLANTS (400 TPD) AND LARGE PLANT (4,000 TPD)
TREATMENT COMPONENT
LEVEL A: SCREENING
PRIMARY SEDIMENTATION
COOLING TOWER
SHALLOW LAGOON
(30 day retention)
AERATED LAGOON
(Settling)
AERATED LAGOON
(No Settling)
ANAEROBIC/AEROBIC LAGOON
ACTIVATED SLUDGE
SAND FILTRATION
SPRAY IRRIGATION
LEVEL B
COST OF EFFLUENT REDUCTION ALTERNATIVE ($1,000)
LEVEL C LEVEL D LEVEL E LEVEL F LEVEL G
Small Large Small Large Small Large Small Large Small Large Small Large
6.2
19.2 6.2
19.2 6.2
212.0 787.2
19.2 6.2
50.0 75.0 50.0 75.0 50.0
63.0 240.0 63.0 240.0
114.00 504.0 114.0 504.0
81.0 352.0 81.0 352.0
725.0
19.2 6.2
75.0 50.0
2960 725.0
111.1
19.2 6.2
75.0 50.0
19.2
75.0
81.0 352.0
2960 725.0 2960
419.2 111.1 419.2
242.3 1508.3
TOTAL CAPITAL INVESTMENT 251.2 950.2 526.2 1977.4 311.5 1767.5 781.2 3054.2 892.3 3473.4 973.3 3825.4
($1,000)
TOTAL ANNUAL COSTS
($1,000)
49.7 151.2 102.5 321.3 72.1 417.9 47.5 194.7 62.8 241.4 81.2 296.1
-------
TABLE 33
INVESTMENT AND ANNUAL COSTS BY EFFLUENT REDUCTION LEVEL FOR FROZEN POTATO PRODUCTS
SUBCATEGORY FOR TYPICAL SMALL PLANT (400 TPD) AND LARGE PLANT (1000 TPD)
COST OF EFFLUENT REDUCTION ALTERNATIVE ($1000)
TREATMENT COMPONENT
LEVEL A: SCREENING
PRIMARY SEDIMENTATION
SHALLOW LAGOON
(30 day retention)
AERATED LAGOON
(Sett! ing)
AERATED LAGOON
(No Settling)
ANEROBIC/AEROBIC LAGOON
ACTIVATED SLUDGE
SAND FILTRATION
SPRAY IRRIGATION
LEVEL B LEVEL
Small Large Small
6.2 11.0 6.2
176.0 345.0 176.0
63.0
113.0 245.0 113.0
160.0
210.0 450.0 210.0
C LEVEL D LEVEL E
Large Small Large Small Large
11.0 6.2 11.0 6.2 11.0
345.0 176.0 345.0 176.0 345.0
124.0 63.0 124.0
245.0
350.0
450.0
720.0 1470
223.9 660.3
LEVEL F LEVEL G
Small Large Small Large
6.2 11.0 6.2 11.0
176.0 345.0
80.0 175.0
720.0 1470 720.0 1470
107.0 212.0 107.0 212.0
TOTAL CAPITAL INVESTMENT
($1,000)
TOTAL ANNUAL COST
($1,000)
505.2 1051.0 728.2 1525.0 469.1 1140.3 902.2 1826.0 1009.2 2038.0 1089.2 2213.0
100.7 188.9 144.5 273.6 94.8 246.5 67.0 151.7 81.9 176.2 99.9 211.2
-------
TABLE 34
INVESTMENT AND ANNUAL COSTS BY EFFLUENT REDUCTION LEVEL FOR DEHYDRATED POTATO PRODUCTS
SUBCATEGORY FOR TYPICAL SMALL PLANT (200 TPD) AND LARGE PLANT (600 TPD)
LEVEL B
COST OF EFFLUENT REDUCTION ALTERNATIVE ($1,000)
LEVEL C LEVEL D LEVEL E
LEVEL F
LEVEL G
TREATMENT COMPONENT
LEVEL A: SCREENING
PRIMARY SEDIMENTATION
SHALLOW LAGOON
(30 day retention)
AERATED LAGOON
(Setting)
AERATED LAGOON
(No Settling)
ANAEROBIC/AEROBIC LAGOON
ACTIVATED SLUDGE
SAND FILTRATION
SPRAY IRRIGATION
Capital Annual Capital
3.3 6.9 3.3
95.0 200.0 95.0
30.0
60.0 130.0 60.0
80.0
115.0 250.0 115.0
Annual
6.9
200.0
72.0
130.0
184.0
250.0
Capital Annual Capital Annual Capital Annual Capital Annual
3.3 6.9 3.3 6.9 3.3 6.9 3.3 6.9
95.0 200.0 95.0 200.0 95.0 200.0 95.0 200.0
30.0 72.0
40.0 92.0
400.0 805.0 400.0 805.0 400.0 805.0
61.0 120.0 61.0 120.0
88.8 276.2
TOTAL CAPITAL INVESTMENT 273.3 586.9 383.3 842.9 217.1 555.1 498.3 1011.9 559.3 1131.9 599.3 1223.9
($1000)
TOTAL ANNUAL COST
($1000)
49.6 113.0 75.4 162.0 41.6 114.1 32.6 80.0 42.7 96.2 53.7 116.2
-------
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147
-------
TABLE 36 TOTAL SUBCATEGORY AND INDUSTRY INVESTMENT COST FOR EACH LEVEL
OF EFFLUENT REDUCTION
SUBCATEGORY
TOTAL INVESTMENT FOR EFFLUENT REDUCTION LEVEL
($1,000,000)
LEVEL LEVEL LEVEL LEVEL LEVEL LEVEL
SIZE B C D E F G
APPLE JUICE
(SOLE PRODUCT)
TOTAL
APPLE PRODUCTS
(EXCEPT JUICE)
TOTAL
CITRUS PRODUCTS
TOTAL
FROZEN POTATO
PRODUCTS
TOTAL
SMALL
LARGE
SMALL
LARGE
SMALL
LARGE
SMALL
LARGE
0.52
0.37
0.89
3.84
1.62
5.46
12.21
4.62
16.83
8.39
6.00
14.39
0
0
1
8
3
.92
.64
.56
.88
.34
12.22
25
9
35
12
10
.57
.61
.18
.09
.16
2T.25
1.04
0.74
1.78
5.88
2.39
8.27
15.14
8.59
23.73
7.79
7.59
15.36
6.08
2.18
8.26
29.04
7.20
36.24
37.97
14.84
52.81
14.98
12.16
27.14
7
2
•
•
04
68
9.72
33
8
41
43
16
60
16
13
30
•
•
•
•
•
•
•
•
.
60
31
91
37
88
25
75
57
32
7
2
lo
35
9
44
47
18
65
18
14
32
.28
.85
.13
.40
.09
.49
.30
.59
.89
.08
.74
.82
DEHYDRATED
POTATO
PRODUCTS
TOTAL
APPLE TOTAL
CITRUS TOTAL
POTATO TOTAL
INDUSTRY TOTAL
SMALL 9.10
LARGE 6.51
15.6!
12.76 7.23 16.59 18.62 19.96
9.36 6.16 11.23 12.56 13.59
22.12 13739" 27.82 31.18 33.55
13.78 10.05 44.50 51.63 54.62
35.18 23.73 52.81 60.25 65.89
44.37 28.77 54.96 61.50 66.37
93.33 62.55 152.27 173.38 186.88
148
-------
TABLE 37 TOTAL SUBCATEGORY AND INDUSTRY ANNUAL COST FOR EACH LEVEL OF
EFFLUENT REDUCTION
TOTAL INVESTMENT FOR EFFLUENT REDUCTION
LEVEL ($1,000,000)
LEVEL LEVEL LEVEL LEVEL LEVEL LEVEL
SUBCATEGORY SIZE B C D E F G
APPLE JUICE
(SOLE PRODUCT)
TOTAL
APPLE PRODUCTS
(EXCEPT JUICE)
TOTAL
CITRUS PRODUCTS
TOTAL
FROZEN POTATO
PRODUCTS
TOTAL
DEHYDRATED
POTATO
PRODUCTS
SMALL
LARGE
SMALL
LARGE
SMALL
LARGE
SMALL
LARGE
SMALL
LARGE
0.17
0.11
0.28
1.42
.41
1.83
2.42
.73
3.15
1.67
1.26
2.93
1.65
1.25
.40
.20
0.60
5.09
.73
5.82
4.98
1.56
6.54
2.40
1.82
4.22
2.51
1.80
.20
.18
0.38
1.32
.54
1.86
3.50
2.03
5.53
1.57
1.64
3.21
1.39
1.27
.21
.09
0.30
1.14
.40
1.54
2.31
.95
3.26
1.11
1.01
2.12
1.09
.89
.44
.18
0.62
2.09
.56
2.65
3.05
1.17
4.22
1.36
1.17
2.53
1.42
1.07
.52
.23
0.75
2.74
.95
3.69
3.95
1.44
5.39
1.66
1.41
3.07
1.79
1.29
TOTAL
APPLE TOTAL
CITRUS TOTAL
POTATO TOTAL
2790" ¥73T 2.66 T798" 2.49 3.08
2.11 6.42 2.24
3.15 6.54 5.53
5.83 8.53 5.87
1.84 3.27 4.44
3.26 4.22 5.39
4.10 5.02 6.15
INDUSTRY TOTAL
11.09 21.49 13.64 9.20 12.51 15.98
149
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TABLE 38 TOTAL CAPITAL INVESTMENT TO MEET EACH LEVEL OF EFFLUENT
REDUCTION
CAPITAL INVESTMENT ($ Million) TOTAL
EFFLUENT APPLE
LEVEL JUICE
B
C
D
E
F
G
(1977)
(1983)
(1977)
(1977)
(1983)
(1983)
.06
.19
.32
.55
.84
.92
APPLE
PRODUCTS
.36
1.70
1.47
2.39
3.51
4.02
CITRUS
PRODUCTS
1
7
4
5
7
9
.78
.59
.39
.58
.94
.72
FROZEN
POTATOES
1.
4.
2.
2.
4.
4.
57
14
89
96
00
82
DEHYDRATED
POTATOES
1.
3.
2.
3.
4.
4.
70
83
52
03
13
90
INVESTMENT
BY LEVEL
5
17
11
14
20
24
.47
.45
.59
.51
.42
.38
150
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TABLE 39 TOTAL ANNUAL COST TO MEET EACH LEVEL OF EFFLUENT REDUCTION
ANNUAL COST ($ Million) TOTAL
EFFLUENT
LEVEL
B
C
D
E
F
G
(1977)
(1983)
(1977)
(1983)
(1983)
(1983)
APPLE
JUICE
.02
.08
.07
.02
.08
.11
APPLE CITRUS FROZEN DEHYDRATED
PRODUCTS PRODUCTS POTATOES POTATOES
.12
.91
.33
.09
.29
T43
.33
1.40
1.02
.34
.64
1.01
.32
.74
.60
.23
.36
.54
.32
.78
.50
.22
.39
.58
ANNUAL COST
BY LEVEL
1.11
3.91
2.52
0.90
1.76
2.67
151
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ENERGY REQUIREMENTS
El e c tr i c al En er qy
Electricity is required in the treatment of food processing wastes
primarily for pumping and aeration. The aeration horsepower is a
function of the waste load and the horsepower for pumping depends on
waste water flow rate.
The fruit and vegetable processing industry as a whole is not a large
consumer of electrical energy. We estimate that the average power cost
per ton of raw material processed is on the order of $0.50, and on this
basis the total power bill in 1973 for apple, citrus and potato was
about 16,400,000 tons x $0.50/ton or $8,200,000/yr.
Although power requirements for waste treatment systems at some plants
may approach 20 percent of the total power consumption, it is estimated
that the average contribution of waste treatment systems at apple,
citrus and potato processing plants is considerably less than 10 percent
of the total at present and should not exceed 10 percent in the future.
Thermal Energy
Thermal energy costs roughly equal electrical energy costs for
operations within the industry. Waste treatment systems impose no
significant addition to the thermal energy requirement of plants.
Wastewater can be reused in cooling and condensing service if it is
separated from the process waters in nonbarometric type condensers.
These heated waste waters improve the effectiveness of anaerobic ponds
which are best maintained at 32°C (90°F) or more. Improved thermal
efficiencies are coincidentally achieved within a plant with this
technique.
tfastewater treatment costs and effectiveness can be improved by the use
of energy and power conservation practices and techniques in each plant.
The waste load increases with increased water use. Reduced water use
therefore reduced the waste load, pumping costs, and heating costs, the
last of which can be further reduced by water reuse as suggested pre-
viously.
152
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NON-WATER POLLUTION CONSIDERATIONS
Solid Wastes
The disposal of most of the solid wastes from the fruit and vegetable
processing industry is directed toward animal feed. Solid waste
consists of cull fruits and vegetables, discarded pieces, and residues
from various processing operations. For example, the net energy and
total digestible nutrient content of dried potato pulp is very nearly
the same as U.S. No. 2 corn. One exception of waste utilization as
animal feed occurs when excessive amounts of pesticides have been used
during the growing season and the wastes are contaminated. If this is
the case, the wastes are then used for fertilizer or land fill.
Screening devices of various designs and operating principles remove
large-scale solids such as peel, pulp, cores, and seeds prior to waste
water treatment. These solids are then either processed for co-
products, sold for animal feed, or land filled.
The solid material, separated during waste water treatment, containing
organic and inorganic materials, including those added to promote solids
separation, is called sludge. Typically, it contains 95 to 98 percent
water prior to dewatering or drying. Some quantities of sludge are
generated by both primary and secondary treatment systems with the type
of system influencing the quantity. The following table illustrates
this :
Treatment
Dissolved air flotation
Anaerobic lagoon
Aerobic and aerated lagoons
Activated sludge
Extended aeration
Anaerobic contact process
Sludge Volume as Percent of
Raw Wastewater Volume
Up to 10%
(Sludge accumulation in these
(lagoons is usually not suffi-
(cient to require removal at
(any time.
10 - 15%
5 - 10*
approximately 2%
The raw sludge can be concentrated, digested, dewatered, dried,
incinerated, land-filled, or spread in sludge holding ponds. In most
cases, as stated previously, the sludge goes to animal feed.
Sludge from air flotation with polyelectrolyte chemicals added has
proven difficult to dewater, and thereby, presents problems in disposal
153
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by any of the aforementioned handling processes. Also, certain
polyelectrolyte chemicals rendered the sludge inadequate for animal
consumption.
Sludge from secondary treatment systems is normally dewatered or
digested sufficiently for hauling and sale as animal feed or fertilizer
or for land fill. The final dried sludge material can be safely used as
an effective soil builder. Prevention of runoff is a critical factor in
plant-site sludge holding ponds. Costs of typical sludge handling
techniques for each secondary treatment system generating enough sludge
to require handling equipment are already incorporated in the costs for
these systems.
silt water from cleaning root commodities such as potatoes is usually
handled separately from the food processing water which goes through
secondary treatment. The silt water being relatively free of organic
matter goes to silt settling ponds. Silt accumulated in the bottom of
the ponds is removed annually and disposed of by adding it to pond
dikes. These ponds are generally abandoned after useful performance,
with new ponds being established.
In addition to the solid wastes generated as a result of food
processing, solid waste is also generated in terms of trash normally
associated with activities. This material may be disposed of at the
plant site or collected by the local municipality with disposal by
incineration or sanitary land fill. The solid wastes or trash comprises
packaging materials, shipping crates, and similar dry combustible
materials.
Sanitary wastes are usually handled by a separate system in the plant
(in most cases municipal) and consequently are not involved in the food
processing waste water treatment. The sanitary wastes are of low volume
and quite efficiently treated in standard sanitary waste treatment
facilities.
Air_Pollution
Odors are the only significant air pollution problem related to waste
water treatment in the fruit and vegetable canning industry. Fetid
conditions usually occur in anaerobic environments within aerobic
systems. It is generally agreed, however, that anaerobic ponds will not
create serious odor problems unless the process water has a sulfate
content. Sulfate waters are a localized condition varying even from
well to well in a specific plant. The anaerobic pond odor potential is
somewhat unpredictable as evidenced by a few plants that have odor
problems without sulfate waters. In these cases a cover and collector
of the off-gas from the pond controls odor. The off-gas is then flared.
The change in weather in the spring in northern climates may be
accompanied by an increase of odor problem.
15U
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other potential odor generators in the waste water treatment are tanks
and process equipment for the anaerobic contact process that normally
generate methane. However, with the process restricted to a specific
piece of equipment it is not difficult to confine and control odors by
collecting and flaring the off-gases. These gases' high heating value
makes it economical and standard practice to recover the heat for use in
the waste water treatment process.
Odors have been produced by some air flotation systems which are
normally housed in a building, thus localizing, but intensifying the
problem. Minimizing the unneccessary delay of disposal of any skimmings
or grease-containing solids has been suggested.
Odors can best be controlled by elimination of conditions that generate
odors. Using low sulfate process water, careful screening of waste
water to remove organic solids, shallow holding ponds (approximately
0.45 meters optium (1.5 feet), and alkaline pH conditions aid in odor
reduction. Also, certain types of bacteria have been found to be
particularly well suited to control odor problems. Controls for odors
once emanated remain largely unproven at this time.
Other air pollutants such as fog from cooling towers or the pollutants
associated with the combustion of fossil fuel are common to all
industrial processes are not judged to be significant problems in the
food processing industry.
Noise
The only material increase in noise caused by a waste water treatment
system is that caused by the installation of an air flotation system or
aerated lagoons with air blowers. Large pumps and an air compressor are
part of an air flotation system. Such a system is normally housed in a
low-cost building; thus, the substantial noise generated by an air
flotation system is confined and perhaps amplified by installation prac-
tices. All air compressors, air blowers, and large pumps in use on
intersively aerated treatment systems, and other treatment systems as
well, may produce noise levels in excess of the Occupational Safety and
Health Administration standards while the industry should consider these
standards in solving its waste pollution problems they are not
considered to be serious problems in the food processing industry.
155
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SECTION IX
EFFLUENT REDUCTION ATTAINABLE THROUGH THE
APPLICATION OF BEST PRACTICABLE CONTROL
TECHNOLOGY CURRENTLY AVAILABLE
INTRODUCTION
The waste water effluent limitations which must be achieved by July 1,
1977 specify the degree of effluent reduction attainable through the
application of the Best Practicable Control Technology Currently
Available. Best Practicable Control Technology Currently Available is
based upon the average of the best existing performance by plants of
various sizes, ages, and unit processes within the industrial
subcategory. This average is not based upon a broad range of plants
within the canned and preserved fruits and vegetables industry, but
based upon performance levels achieved by exemplary plants.
Consideration has, also, been given to the following:
The total cost of application of technology in relation
to the effluent reduction benefits to be achieved from
such application;
The size and age of equipment and facilities involved;
The processes employed;
The engineering aspects of the application of various types
of control techniques;
Process changes;
Non-water quality environmental impact(including energy
requirements) .
Best Practicable Control Technology Currently Available emphasizes
treatment facilities at the end of canning, freezing, or dehydrating
process but includes the control technologies within the process itself
when the latter are considered to be normal practice within the
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 the control facilities.
157
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EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION OF
BEST PRACTICABLE CONTROL TECHNOLOGY CURRENTLY AVAILABLE
The waste water effluent limitation guidelines for the apple, citrus and
potato segment of the canned and preserved fruits and vegetables
industry are based on the information contained in Section III through
VIII of this report. This industry segment consists of processors of
the following products: apple products (except caustic peeled and
dehydrated products); citrus products (except pectin and pharmaceutical
products) ;and all frozen and dehydrated potato products. A
determination has been made that the quality of effluent attainable
through the application of the Best Practicable Control Technology
Currently Available is as listed in Table 40. These guidelines are
developed from the average performances of exemplary secondary
biological treatment systems (listed in Table 41).
A biological treatment system which is permitted to operate at a
constant food to microorganism ratio throughout the year and with
minimum operational changes would have a natural variation of 50 percent
as explained in Section VII and as demonstrated by the performance of an
activated sludge plant at PO-128. A similar system with careful
operational control and proper design can be operated within 25 percent
of the average on a monthly operating basis. A system without optimum
operational control has been used to account for normal treatment
variation. Thus, a factor of 50 percent has been used to calculate the
maximum 30 day effluent limitation. A further allowance of 100 percent
has been applied to a maximum 30 day effluent limitation in order to
develop the maximum daily effluent limitation.
Land disposal is widely practiced in the industry and is a highly
effective technology for treating wastes from plants processing apples,
citrus and potatoes. In the development of the recommended guidelines,
serious consideration was given to making land disposal and consequent
zero discharge mandatory in all instances where appropriate land is
economically available to the processor. The recommended guidelines in
Table 40 do not make zero discharge through land disposal mandatory
because of the difficulty of defining "economically available".
However, land treatment should be selected in cases where suitable land
is available.
IDENTIFICATION OF BEST PRACTICABLE CONTROL
TECHNOLOGY CURRENTLY AVAILABLE'
Best Practicable Control Technology Currently Available for the apple
(except caustic peeled and dehydrated products) citrus (except pectin
and pharmaceutical products) and potato (dehydrated and frozen)
158
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processing segments of the canned and preserved fruits and vegetables
industry includes preliminary screening, primary settling (potato only)
and biological secondary treatment. Strict management control over
housekeeping and water use practices can produce a raw waste load as
cited in Section V for apples, citrus and potatoes (See Tables 19,20,
21). No special in-plant modification is required.
The stated guidelines for the two apple subcategories can be achieved by
applying the Best Practicable Control Technology to the appropriate
apple subcategory raw waste load developed in Section V (See Table 19).
The Best Practicable Control Technology Currently Available in the apple
industry includes screening and secondary biological treatment. The
recommended effluent limitation guidelines for 1 July 1977 for the apple
products (except juice) subcategory are the average of the exemplary
biological treatment systems. The BODS effluent limitation is the
average of the BODJ5 discharge (listed on Table 41) from the secondary
biological treatment systems at AP-140, AP-121, AP-108, AP-103, AP-102
and AP-101. The suspended solids effluent limitation is the average of
the TSS discharges from AP-140, AP-121, AP-108 and AP-103. The 50
percent factor discussed previously is applied to these BOD5 and TSS
annual limits to calculate the maximum thirty day averages (Table 40).
The exemplary biological treatment systems used by these plants are
activated sludge, anaerobic plus aerobic lagoons, multiple aerated
lagoons and trickling filter plus aerated lagoons. The recommended
effluent limitation guidelines for 1 July 1977 for the apple juice
subcategory are calculated from the apple products effluent limitation
with raw waste effluent data from Table 19. The apple juice raw waste
BOD is only one-third as large as the apple products BOD and the apple
juice suspended solids is only one-half as large as the apple products
SS. Thus, the calculated apple juice subcategory limitations are almost
one-half the apple products (except juice) subcategory. These
limitations are being met by AP-140, AP-121, and AP-103. AP-102
processes apple juice.
159
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TABLE 40
MAXIMUM THIRTY DAY AVERAGE
RECOMMENDED EFFLUENT LIMITATION
GUIDELINES FOR 1 JULY 1977
PLANT SUECATEGORY (1) BODS SUSPENDED SOLIDS
J£2/JSJS3~ lb/T JSH/kJiS Ib/T
APPLES: Apple Juice 0.30 0.60 0.40 0.80
APPLES: Apple Products
Except Juice 0.55 1.10 0.70 1.40
CITRUS: Juice, Oil, Segments
Peel Products 0.40 0.80 0.85 1.70
POTATOES: Frozen Products 1.40 2.80 1.40 2.80
POTATOES: Dehydrated
Products 1.20 2.40 1.40 2.80
(1) For all subcategories pH should be between 6.0 and 9.0
The stated guidelines for the citrus subcategory can be achieved by
applying the Best Practicable Control Technology to the citrus
subcategory raw waste load developed in Section V (See Table 20). The
Best Practicable Control Technology Currently Available in the citrus
industry includes cooling towers for the recirculation of weak cooling
water which is currently segregated from the high BOD wastes which are
treated with preliminary screening and secondary biological treatment.
The recommended effluent limitation guidelines for 1 July 1977 for the
citrus products subcategory are based on the performances of the
exemplary biological systems treating citrus wastes. The BODJ5 effluent
limitation is the maximum BOD5 discharge (listed on Table 41) of the
secondary biological treatment systems at CI-127, CI-118, CI-105, CI-
106, CI-108, CI-123 and CI-119. The suspended solids effluent
limitation is the average of the TSS discharges from CI-127, CI-118, CI-
105, CI-106, CI-108, CI-123 and CI-119. The maximum thirty day averages
(Table 40) are calculated from these annual averages by applying a
factor of 50 percent. The exemplary biological treatment systems used
by these plants are activated sludge, anaerobic plus aerobic lagoons,
trickling filter plus aerated lagoons, multiple aerated lagoons plus
activated sludge and aerated lagoons.
The stated guidelines for the two potato subcategories can be achieved
by applying the Best Practicable Control Technology to the appropriate
160
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subcategory raw waste load developed in Section V (See Table 21). The
Best Practicable Control Technology Currently Available in the potato
industry is screening, primary treatment (silt and process water) and
secondary biological treatment. The recommended effluent limitation
guidelines for 1 July 1977 for the frozen potato products subcategory
are based on the performances of the exemplary biological systems
treating potato wastes. The BOD5 effluent limitation is the maximum
BOD5 discharge (listed on Table 41) of the secondary biological
treatment systems at PO-110, PO-128 and PO-127. The suspended solids
limitation is the maximum TSS discharge from PO-127 and PO-128. The
maximum thirty day averages (Table 40) are calculated from these annual
averages by applying a factor of 50 percent. The exemplary biological
treatment systems used by these plants are activated sludge, trickling
filters, and multiple aerated lagoons. The recommended effluent
limitation guidelines for 1 July 1977 for the dehydrated potato
subcategory are based on the raw waste data in Table 21 and their
performances of the exemplary biological systems treating potato wastes.
The BOD5 and suspended solids effluent limitations for dehydrated potato
products are less than the limitations for frozen potato products
because of the substantial difference in the raw waste loads from the
two potato subcategories (Table 21) . The BOD5_ limitation for dehydrated
potato products is the average of the BOD discharge (listed on Table 41)
of PO-110, PO-128 and PO-127. The TSS limitation is the maximum TSS
discharge from PO-128 and PO-127. The maximum thirty day averages
(Table 40) are calculated from these annual averages by applying a
factor of 50 percent. PO-128 processes dehydrated potato products.
Both PO-128 and PO-127 are Canadian potato processors.
Thus, the effluent guidelines are presently being achieved by apple,
citrus and potato plants in each subcategory by secondary biological
treatment. Many other plants are also achieving the guidelines through
land treatment. Both spray irrigation and flood irrigation are
currently practiced successfully. With this technology and proper
management, there is no discharge of pollutants to navigable waters.
RATIONALE FOR THE SELECTION OF
BEST PRACTICABLE CONTROL TECHNOLOGY
CURRENTLY AVAILABLE
Age And Size Of Equipment And Facilities
The industry has generally modernized its plants as new methods that are
economically attractive have been introduced. No relationship between
age of plant and effectiveness of its pollution control was found. (See
Section IV.) Also, size was not a significant factor, even though some
161
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plants vary widely in size. Small plants are not mechanized to the
extent of some larger plants in the industry; still they are able to
achieve at least as effective control as larger plants. This is partly
because the small-scale operation permits more options for small low-
cost in-plant equipment that are not available to larger operations
because of the immense volume of materials concerned.
Total Cost Of Application In Relation To Effluent Reduction Benefits
Based on the information contained in Section VIII of this report, the
combined small and large apple, citrus and potato processors must invest
$5.47 million (Level B) in construction of biological systems and
modifications to existing systems and $11.59 million (Level D) in land
and construction of land treatment facilities (See Table 38). If
activated sludge is the biological system utilized, the cost could be as
high as $14.5 million (Level E) plus land treatment costs. Thus, the
total investment cost to achieve the best practicable effluent
limitations is approximately $17 million but could be high as $26
million. This $17 million investment amounts to a cost of about $3.40
per annual ton of processing capacity and about 1.4 percent of the
estimated industry investment of $1.2 billion.
The cost increase to the consumer would be approximately 2.3 percent of
the retail price of the products.
The total U.S. investment does not include costs for processors
discharging to municipal sewers, but it does include processors
utilizing land treatment.
Engineering Aspects Of Control Technique Applications
The specified level of technology is practicable because it is being
practiced by plants in all subcategories with multiple aerated lagoons,
activated sludge, anaerobic plus aerobic lagoons, trickling filters,
trickling filters plus aerated lagoons or activated sludge plus aerated
lagoons. With screening, primary treatment (potato only) and a
biological system, 6 apple, 7 citrus, and 3 potato plants are presently
achieving a BOD5 discharge of less than 1 kg/kkg (2 Ib/T) and twelve
apple, citrus, and potato plants are presently achieving a BOD discharge
of less than 0.25 kg/kkg (0.5 Ib/T) (See Table 41).
Four apple plants including one juice processing plant are presently
meeting the 1977 guidelines for BOD and SS with biological treatment.
It must be noted that two biologically treated effluents are not
discharged but are disposed of through land treatment systems.
Activated sludge, anaerobic plus aerobic lagoons, multiple aerobic
162
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lagoons, and trickling filters plus aerated lagoons are the exemplary
biological treatment systems.
Five citrus products plants are presently meeting the 1977 guidelines
for BOD and SS. Two additional citrus processors are meeting the BOD
limitations only. Multiple aerated lagoons, anaerobic/aerobic lagoons,
aerated lagoon with trickling filter and activated sludge are the
exemplary treatment system, of these seven plants, five would not
require cooling towers or ponds for barometric cooling waters.
Two Canadian potato processing plants are able to achieve high levels of
effluent reduction for BOD5 and suspended solids through the utilization
of exemplary secondary biological treatment systems. An American potato
processing plant is able to achieve high levels of effluent reduction
for BOD5. Each of these three secondary biological treatment systems
achieve at least the effluent reduction required through the application
of Best Practicable Control Technology Currently Available on a seasonal
average. The discharge from the secondary biological system treating
frozen and dehydrated potato processing wastes from plant PO-128 was
able to achieve the effluent reduction required through the application
of the Best Practicable Control Technology Currently Available at all
times during their 44 week 1972 processing season. Their maximum
monthly BOD5 and TSS discharges, which are 1.04 kg/kkg (2.08 Ib/ton) and
1.32 kg/kkg (2.63 Ib/ton) respectively, are less than the effluent
limitations for either frozen or dehydrated potato products. The
discharge from the secondary biological system treating frozen potato
processing wastes from plant PO-127 has been able to achieve the
effluent reduction required through the application of the best
practicable technology from December 1972, through December 1973. Their
maximum monthly BOD5 and TSS discharges, which are 1.2 kg/kkg (2.4
Ib/ton) and 0.55 kg/kkg (1.1 Ib/ton) respectively, are less than the
effluent limitations for frozen potato products. The exemplary
treatment systems are activated sludge, trickling filters, and multiple
aerated lagoons. (Another treatment system consisting of anaerobic and
aerobic lagoons included in earlier reports was omitted because of
inaccurate operating data. With proper management along with reliable
quality control, this system may demonstrate that it is exemplary.)
Thus, biological treatment has been shown to be practicable and
currently available technology for achieving the 1977 guidelines for the
apple, citrus and potato industry. In addition the guidelines can be
achieved by land treatment through spray irrigation or flood irrigation
or other ultimate disposal technologies as described in Section VII.
163
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TABLE 41
EFFLUENTS FROM SECONDARY
TREATMENT SYSTEMS
PLANT
AP-140
AP-121
AP-108
AP-103
AP-102
AP-101
CI-127
CI-118
CI-105 (3)
CI-106
CI-109
CI-108
CI-123
CI-119
PO-128 (1)
PO-128 (2)
PO-110
PO-127
CAPACITY
(kkg/D)
50
125
145
170
220
235
225
750
2250
2100
2900
3400
3800
5700
140
140
320
365
BOD5 DISCHARGE
0.10
0.15
0.95
0.22
0.07
0.63
0.05
0.20
0.05
0.25
0.05
0.04
0.05
0.19
0.70
0.10
0.95
0.60
0.20
0.29
1.90
0.44
0.13
1.25
0.10
0.39
0.10
0.49
0.10
0.08
0.10
0.38
1.40
0.20
1.90
1.20
SS DISCHARGE
0.23
0.09
1.35
0.04
----
2.40
0.08
1.55
0.05
0.33
0.05
1.15
0.40
0.16
0.90
0.35
0.40
0.46
0.18
2.70
0.08
----
4.79
0.16
3.10
0.10
0.66
0.10
2.30
0.80
0.31
1.80
0.70
0.80
(1) After screening, primary, activated sludge
(2) After (1) and three aerated lagoons (to receiving waters)
(3) Common treatment system (CI-109)
Approximately 50 percent of the apple plants and apple plant production
utilize land treatment to dispose of their wastes. At least 10
additional apple plants are presently achieving an effluent reduction
greater than required by the application of the Best Practicable Control
Technology Currently Available through land treatment. Approximately 50
percent of the citrus and potato plants and about 50 percent of their
production utilize land treatment to dispose of their wastes. Thus, at
least 20 additional citrus plants and twelve additional potato plants
are currently achieving an effluent reduction greater than required by
the application of the Best Practicable Control Technology Currently
Available.
164
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Process Changes
No major in-plant changes will be needed by most plants to meet the
limits specified. Many plants will need to improve their water
conservation practices and housekeeping, both responsive to good plant
management control.
Non-Water Quality Environmental Impact
The major impact when the option of a biological type of process is used
to achieve the limits will be the problem of sludge disposal. Nearby
land for sludge disposal may be needed but in many cases sludge
conditioning will allow the sludge solids to be treated and sold as
animal feed.
Another problem is the odor that emits periodically from anaerobic
lagoons or localized anaerobic environments within aerobic lagoons. The
odor problem can usually be avoided with well operated systems and
proper in-plant waste management.
There is also a potential detrimental impact on soil systems when
application of waste to soil is not managed adequately. Management must
assure that land treatment systems are maintained commensurate with crop
need and soil tolerance.
Factors To Be Considered In Applying BPCTCA Limitations
1. Land treatment by spray irrigation, or equivalent
methods providing minimal discharge should be encouraged.
2. Limitations are based on 30 day averages (See Table 40) .
Based on performance of biological waste treatment
systems at exemplary plants, the maximum
daily limitations should not exceed the maximum 30 day average
limitations by more than one hundred percent for the
apple juice and apple products, citrus products and
the frozen and dehydrated potato products subcategories
(See Table 42) .
3. The nature of biological treatment plants is such that on the
order of one week may be required to reach the daily maximum
limitation after initial start-up at the beginning of the
processing season.
These values may be omitted when computing average
thirty day limitations.
4. If a plant produces products in more than one subcategory, for
instance apple juice and apple sauce or frozen and dehydrated
165
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potato products, the effluent limitations should be set
by proration on the basis of the percentage of the total
raw material being processed to each product.
5. The production basis which is recommended for applying
these limitations is the daily average production of the
maximum thirty consecutive days.
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TABLE 42
MAXIMUM DAILY AVERAGE
RECOMMENDED EFFLUENT LIMITATION
GUIDELINES FOR JULY 1, 1977
PLANT SUBCATEGORY (1) BODS SUSPENDED SOLIDS
kg/kkg Ib/T kg/kkg Ib/T
APPLES: Apple Juice 0.60 1.20 0.80 1.60
APPLES: Apple products except juice 1.10 2.20 1.40 2.80
CITRUS: Juice, Oil, Segment,
Peel Products 0.80 1.60 1.70 3.40
POTATOES: Frozen Products 2.80 5.60 2.80 5.60
POTATOES: Dehydrated Products 2-40 4.80 2.80 5.60
(1) For all subcategories pH should range between 6.0 and 9.0 at any time.
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SECTION X
EFFLUENT REDUCTION ATTAINABLE THROUGH THE
APPLICATION OF THE BEST AVAILABLE TECHNOLOGY
ECONOMICALLY ACHIEVABLE
INTRODUCTION
The effluent limitations which must be achieved no later than July 1,
1983 are not based on an average of the best performance within an
industrial subcategory, but are determined by identifying the very best
control and treatment technology employed by a specific point source
within the industrial category or subcategory, or by one industry where
it is readily transferable to another. A specific finding must be made
as to the availability cf control measures and practices to eliminate
the discharge of pollutants, taking into account the cost of such
elimination.
Consideration must also be given to:
The age of the equipment and facilities involved;
The process employed;
The engineering aspects of the application of various types
of control techniques;
Process changes;
The cost of achieving the effluent reduction resulting
from application of the technology;
Non-water quality environmental impact (including energy
requirements).
Also, Best Available Technology Economically Achievable emphasizes in-
process controls as well as control or additional treatment techniques
employed at the end of the production process.
This level of technology considers those plant processes and control
technologies which, at the pilot plant, semi-works, or other level, have
demonstrated both technological performances and economic viability at a
level sufficient to reasonably justify investing in such facilities. It
is the highest degree of control technology 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
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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, there may be some technical risk with respect to
performance and with respect to certainty of costs. Therefore, some
industrially sponsored development work may be needed prior to its
application.
EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION
OF THE BEST AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE
The effluent limitation guidelines for the apple, citrus and potato
segment of the canned and preserved fruits and vegetables industry are
based on the information contained in section III through VIII of this
report. This industry segment consists of processors of the following
products; apple products (except caustic peeled and dehydrated
products); citrus products (except pection and pharmaceutical products);
and frozen and dehydrated potato products. A determination has been
made that the quality of effluent attainable through the application of
the best available technology economically achievable is as listed in
Table 43. The technology to achieve these goals is generally available,
although the advanced treatment techniques may not have yet been applied
to a processing plant at full scale.
It was pointed out in Section IX that land treatment was a highly
effective technology for treating apple, citrus and potato wastes. The
considerations of land treatments made in Section IX for 1977 apply here
for 1983 alternatives. Where suitable land is available, irrigation is
an option that not only is recommended from the discharge viewpoint, but
also will usually be more economical than the system otherwise required.
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TABLE 43
MAXIMUM THIRTY DAY AVERAGE
RECOMMENDED EFFLUENT LIMITATION GUIDELINES FOR 1 JULY 1983
PL AN T SU SCAT EGORY ( 1 1 BOD£ SUSPENDED SOLIDS
lb/T
APPLES: Apple Juice 0.10 0.20 0.10 0.20
APPLES: Apple Products
Except Juice 0.10 0.20 0.10 0.20
CITRUS: Juice, Oil, Segments
and Peel Products 0.07 0.14 0.10 0.20
POTATOES: Frozen Products 0.17 0.34 0.55 1.10
POTATOES: Dehydrated Products 0.17 0.34 0.55 1.10
(1) For all subcategories pH should be between 6.0 and 9.0
(2) For all subcategories most probable number (MPN)
of fecal coliforms should not exceed 400 counts per 100 ml.
IDENTIFICATION OF THE BEST AVAILABLE
TECHNOLOGY ECONOMICALLY ACHIEVABLE
The best available technology economically achievable for the apple
(except caustic peeled and dehydrated products), citrus (except pectin
and pharmaceutical products) and frozen and dehydrated potato processing
segment of the canned and preserved fruits and vegetables industry
includes the preliminary screening, primary settling, and secondary
biological treatment listed under the Best Practicable Control
Technology Currently Available. In addition, it includes additional
secondary treatment such as more aerated lagoons or advanced treatment
such as a sand filter following secondary treatment. Disinfection is,
also, included.
Management controls over housekeeping and water use practices will be
stricter than required for 1977. However, no additional in-plant
controls will be required to achieve the specified levels of effluent
reduction. The following paragraphs describe several in-plant controls
and modifications that provide alternatives and trade-offs between
controls and additional effluent treatment. In many cases they are
economically more attractive than additional treatment facilities.
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1. Recycle of raw material wash water. Solids removal and
chlorination are required. This step is presently being
practiced at a few potato plants and will soon be practiced in
the citrus industry.
2. Utilization of low water usage peel removal equipment. Some of
this equipment is being used, such as the rubber abrading and
brushing system used for the removal of potato peel.
3. Removal of solids from transport and slicing waters.
Hydroclones or liquid cyclones can recover starch particles
from potato cutting water and apple particles from apple-
slicing waters. The hydroclones can, also, be used to remove
solid material from total plant waste waters. Up to 50 percent
total BOD removal is possible. The system is presently being
used on a limited basis in the potato industry. Its
applicability may vary from plant to plant.
4. Improved mechanical cleaning of belts to replace belt wash
water.
5. Recirculation of all cooling water through cooling towers or
spray ponds. Cooling waters include barometric water, can-
cooling water, bottle chilling water, etc.
6. Practice of extensive dry cleanup to replace washing and, where
possible, use of continuous dry cleanup and materials recovery
procedures. Push-to-open valves need to be used wherever
possible. Spray nozzles can be redesigned for lower water
flow. Automatic valves that close when the water is not in use
should be installed.
The stated guidelines for the two apple subcategories can be achieved by
adding aerated lagoons and/or shallow lagoons and/or a sand filter plus
disinfection (chlorination) to the best practicable control technology.
The recommended effluent limitation guidelines for 1 July 1983 for the
apple juice and apple products (except juice) subcategories are based on
the performances of the best secondary biological systems treating apple
wastes. The BOD5 effluent limitation is based on the BOD5 discharge
from the treatment system at plant AP-102 and the suspended solids
effluent limitation is based on the maximum TSS discharge from the
treatment systems at plant AP-121 and AP-103. As described previously,
these annual averages are converted to maximum thirty day limitations
(Table 43) by applying a factor of 50 percent. The guidelines for the
citrus subcategory can be attained through the addition of an
anaerobic/aerobic lagoon and shallow lagoon or an aerated lagoon and/or
a sand filter plus disinfection (chlorination) to the best practicable
control technology currently available. The recommended effluent
limitation guidelines for 1 July 1983 for the citrus products
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subcategory are based on the performances of the best secondary
biological systems treating citrus wastes. The BODS effluent limitation
is based on the average BODS discharges (listed on Table 41) from
treatment systems at plant CI-127, CI-105, CI-108 and CI-123. The
suspended solids limitation is based on the maximum TSS discharge from
the treatment systems at plant CI-127 and CI-105. The maximum thirty
day averages (Table 43) are calculated from these annual averages by
applying a factor of 50 percent. The guidelines for the two potato
subcategories can be achieved by adding an aerated lagoon and a shallow
lagoon or an aerated lagoon and/or sand filtration plus disinfection
(chlorination) to the best practicable control technology. The
recommended effluent limitation guidelines for 1 July 1983 for the
frozen and dehydrated potato products subcategories are based on the
performances of the best secondary biological systems treating potato
wastes. The BODS effluent limitation is based on the BOD discharge to
receiving waters from the treatment system at plant PO-128. The
suspended solids limitation is based on the average TSS discharge to
receiving waters from treatment systems at plant PO-128 and PO-127.
Both PO-128 and PO-127 are Canadian potato processing plants. The
maximum thirty day averages (Table 43) are calculated from these annual
averages by applying a factor of 50 percent. The guidelines for all
five subcategories can also be achieved by land treatment if suitable
land is available (See Section IX). Screening and primary treatment
(potato only), a shallow mixing lagoon and spray irrigation achieve a
minimal waste water discharge.
RATIONALE FOR THE SELECTION OF BEST AVAILABLE CONTROL TECHNOLOGY
ECONOMICALLY ACHIEVABLE
Age And Size Of Equipment And Facilities
Neither size nor age was found to affect the effectiveness of the best
available technology economically achievable. In-plant control can be
managed quite effectively in older plants even though the technologies
required for reducing the raw waste loads to low levels may be more
costly to install in older plants. For example, rerouting of sewers to
segregate waste streams could be difficult and costly.
The smaller operations have more low cost in-plant waste water reduction
alternatives than larger plants where immense quantities of materials
are involved. It is anticipated that many small plants will find land
disposal the best alternative. Municipal treatment is, also, an
alternative in many cases.
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Total Cost Of Application In Relation To Effluent Reduction Benefits
Based on information contained in Section VIII of this report, the
industry as a whole would have to invest about between $5.9 and $11.7
million above that required to meet the 1977 standards. This investment
is in new construction of secondary biological or advanced waste
treatment facilities. The total investment cost including land and land
treatment costs to achieve the best practicable effluent limitations
(Section IX) ranged from $17 to $26 million. The total investment cost
including land to achieve the best practicable and best available
effluent limitations is $29 to $36 million. This $12.7 million
investment to achieve the best available effluent reduction amounts to a
cost of approximately $2.30 per annual ton of processing capacity and
approximately 1.0 percent of the estimated industry investment of $1.2
billion. The combined cost of the best practicable and the best
available technology amounts to a cost of between $5.70 and $7.20 per
annual ton of processing capacity and between 2.4 percent and 3.0
percent of the estimated industry investment.
The cost to the consumer would be about 1.6 percent of the retail price
of the products to achieve best available technology only or the cost
for both best practicable and best available technology would be between
3,8 percent and 4.8 percent of the retail price of the products.
All plants discharging to streams can implement the best available
technology economically achievable; the technology is not affected by
different processes used in the plants.
Engineering Aspects Of Control Technique Application
The specified level of technology is achievable. Biological secondary
treatment is practiced throughout the apple, citrus and potato industry
and sand filtration is practiced in at least one potato plant (England).
With present biological treatment systems without advanced treatment
methods such as sand filtration, at least one apple, citrus or potato
plant in each of the five subcategories is presently achieving the high
levels of effluent reduction required by the application of the Best
Available Control Technology Economically Achievable (See Table 41).
For example, the maximum monthly discharges from the biological
treatment system at PO-128 are 0.14 kg/kkg (0.28 Ib/ton) of BOD5 and
0.50 kg/kkg (1.00 Ib/ton) of TSS; these values are less than the
effluent limitations for potato processing (Tabel 43).
No unique in-plant control technology is required to achieve these
standards. However, many of the in-plant controls outlined above under
"Identification of the Best Available Technology Economically
Achievable" have been utilized to achieve high levels of effluent
reduction. An apple sauce, slice, and juice plant has a raw waste BOD
of 1.4 kg/kkg (2.8 Ib/T) compared to the average of over 5 kg/kkg (10
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Ib/T) (See Table 19) . A citrus juice, oil and feed processing plant has
a water usuage of only 710 1/kkg (170 gal/T), BOD of 0.45 kg/kkg (0.9
Ib/T) and suspended solids of 0.02 kg/kkg (0.04 Ib/T). These values
compare with average flow values of 10,110 1/kkg (2425 gal/T), average
BOD of 3.2 kg/kkg (6.4 Ib/T) and average SS of 1.3 kg/kkg (2,6 Ib/T) See
Table 20). >A frozen potato procesor has a water usage of 4,090 1/kkg
(980 gal/T) and a BOD of 4.45 kg/kkg (8.9 Ib/T) compared with average
values of 11,320 1/kkg (2710 gal/T) and 22.9 kg/kkg (45.86 Ib/T) (See
Table 21). Thus, in-plant controls exist as alternatives to additional
secondary biological treatment.
There is an additional 50 percent of the industry that is presently
using land treatment. Thus, over 40 plants are presently achieving
effluent reductions required by 1983 guidelines and many have no
discharge of pollutants to navigable waters. This technology is used
with and without holding ponds in Idaho, Washington, California,
Pennsylvania, Virginia, New York and Florida. Most other states also
have land treatment of the fruit and vegetable industry. Application of
technology for greatly reduced water use will facilitate land disposal.
Experience has shown that good management practices assure that land
disposal and irrigation systems can be maintained commensurate with crop
need and soil tolerance.
Process Changes
No in-plant changes will be needed by most plants to meet the limits
specified. Some available techniques which may be economically
attractive are outlined in the "Identification of the Best Available
Technology Economically Achievable," paragraph above.
Non-Water Quality Environmental Impact
The non-water quality impacts will essentially be those described in
Section IX. It is concluded that nc new serious impacts will be
introduced.
Factors To Be Considered In Applying Level II Guidelines
1. Land treatment by spray irrigation, or equivalent methods providing
minimal discharge should be encouraged.
2. Limitations are based on 30 day averages (See Table 43). Based on
performance of biological waste treatment systems at exemplary
plants, the maximum daily limitations should not exceed the maximum
30 day average limitations by more than one hundred percent for the
apple juice and apple products, citrus products and frozen and
dehydrated potato products subcategories (See Table 44).
3. The nature of biological treatment plants is such that on the order
of one week may be required to reach the daily maximum limitations
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after initial start-up at the beginning of the processing season.
These values may be omitted when computing average thirty day
limitations.
If a plant produces products in more than one subcategory, for
instance, apple juice and apple sauce or frozen and dehydrated
potato products, the effluent limitations should be set by proration
on the basis of the percentage of the total raw material being
processed to each product.
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TABLE 44
MAXIMUM DAILY AVERAGE
RECOMMENDED EFFLUENT LIMITATION
GUIDELINES FOR JULY 1, 1983
PLANT SUBCATEGORY (1)
APPLES: Apple Juice
APPLES: Apple products except juice
CITRUS: Juice, Oil, Segment,
Peel Products
POTATOES: Frozen Products
POTATOES: Dehydrated Products
BOD5
kg/kkg Ib/T
0.14 0.28
0.34 0.68
0.34 0.68
SUSPENDED SOLIDS
kg/kkg Ib/T
0.20
0.20
0.40
0.40
0.20
0.20
0.40
0-40
0.20 0.40
1.10 2.20
1.10 2.20
(1) For all subcategories pH should range between 6.0 and 9.0 at any time.
(2) For all subcategories must probable number (MPN) of fecal coliforms
should not exceed 400 counts per loo ml.
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SECTION XI
NEW SOURCE PERFORMANCE STANDARD
INTRODUCTION.
The effluent limitations that must be achieved by new sources are termed
performance standards. The New Source Performance Standards apply to
any source for which construction starts after the publication of the
proposed regulations for the Standards. The standards are determined by
adding to the consideration underlying the identification of the Best
Practicable Control Technology Currently Available a determination of
what higher levels of pollution control are available through the use of
improved production processes and/or treatment techniques. Thus, in
addition to considering the best in-plant and end-of-process control
technology, New Source Performance Standards are based on an analysis of
how the level of effluent may be reduced by changing the production
process itself. Alternative processes, operating methods or other
alternatives are considered. However, the end result of the analysis is
to identify effluent standards which reflect levels of control
achievable through the use of improved production a particular (as well
as control technology), rather than prescribing a particular type of
process or technology which must be employed. A further determination
made is whether a standard permitting no discharge of pollutant is
practicable.
Consideration must also be given to:
Operating methods;
Batch, as opposed to continuous, operations;
Use of alternative raw materials and mixes of raw materials;
Use of dry rather than wet processes (including substitution of
recoverable solvents for water);
Recovery of pollutants as by-products.
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EFFLUENT REDUCTION ATTAINABLE FOR NEW SOURCES
The effluent limitation for new sources is the same as that for the best
available technology economically achievable (see Section X). This
limitation is achievable in newly constructed plants.
The in-plant controls and waste treatment technology identified in
Section X are available now and applicable to new plants. Land disposal
remains the most desirable disposal method. The land availability
requirements for treatment can be considered in site selection for a new
plant. Thus, land treatment will probably be the most attractive new
source alternative.
The new source technology is the same as that identified in Section X.
The conclusion reached in Section X with respect to Total Cost of
Application in Relation to Effluent Reduction Benefits, the Engineering
Aspects of Control Technique Application, Process Changes, Non-Water
Quality Environmental Impact, and Factors to be Considered in Applying
Level II Guidelines, apply with equal force to these New Performance
Standards.
PRETREATMENT REQUIREMENTS
Large quantities of three constituents of the waste water from plants
within the apple, citrus or potato processing industry have been found
which could interfere with, pass through, or, otherwise, be incompatible
with a well designed and operated publicly owned activated sludge or
trickling filter waste water treatment plant. Waste water constituents
include caustic solutions from peeling operations such as lye dip potato
peelers, D'limonene from citrus peel processing operations, and oil from
frying operations. Adequate control methods can and should be used to
keep significant quantities of these materials out of the waste water.
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SECTION XII
ACKNOWLEDGMENTS
The Environmental Protection Agency wishes to acknowledge the
contributions of Mr. Paul Miller. His professional excellence and
valuable judgment are appreciated as are the contributions of Mr. Ching
Yung.
Appreciation is expressed for the interest of several individuals within
the Environmental Protection Agency: Ken Dostal and George Keeler,
OR5D; Gene McNeil, Region IV; George Webster, Ernst Hall and Allen
Cywin, EGD. Special thanks are due Richard Sternberg and Harold
Thompson and the many secretatries who typed and retyped this document:
Cynthia Wright, Pat Johnson, George Webster, Bettie Rich, Vannessa
Datcher, Jan Beale, and Karen Thompson.
Acknowledgment is made of the active cooperation of industry personnel
who provided information essential to the study.
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SECTION XIII
REFERENCES
BOOKS
1. Besselievre, Edmund B.r The Treatment of Industrial
Wastes, McGraw-Hill Book Co., New York, 1969.
2. Gulp, Russell L. and Gulp, Gordon L., Advanced Waste-
water Treatment, Van Nostrand Reinhold Company, New
York, 1971.
3. Eckenfelder, W. Wesley, Jr., Industrial Water Pollut.ion
Control, McGraw-Hill Book Co., New York, 1966.
4. Eckenfelder, W. Wesley, Jr., Water Quality Engineering
for Practicing Engineers. Barnes and Noble, Inc., New
York, 1970.
5. Fair, Gordon M., Geyer, John C., and Okun, Daniel A.,
Wate r and Wastewater Eng ineeringx t Vol. ^ 2 f „_ Water M Purifi-
cation and Wastewater Treatment and Disposal, John
Wiley & Sons, Inc., New York 1968.
6. Lock, Arthur, Practical Canning, 3rd Edition, Food
Trade Press, London, 1969.
7. Mancy, K. H. and Weber, W. J., Jr., Analysis of Indus-
trial Wastewater , John Wiley 6 Sons, New York, 1971.
8. Talburt, William F. and Smith, Ora, Potato Processing,
2nd Edition, The AVI Publishing Co., Inc., Westport,
Connecticut, 1967.
9. Tressler, Donald K. and Joslyn, Maynard A., Fruit and
Vegetable Juice Processing Technology. 2nd Edition,
The AVI Publishing Co., Inc., Westport, Connecticut, 1971,
10. Weber, Walter J., Jr., Phvsicochemical Processes for
Water Quality Control, John Wiley & Sons, Inc., New
York, 1972.
11. Agricultural Statistics 1972, United States Department
of Agriculture (USDA), U. S. Government Printing Office,
Washington, D.C., 1972.
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12• The Almanac of the Canning, Freezing, and Preserving
Industries |972, 57th Edition, Edward E. Judge and Sons,
Inc., Westminster, Maryland.
13. The Almanac of the Canning^ Freezing, and Preserving
Industries 1971, 56th Edition, Edward E. Judge and Sons,
Inc., Westminster, Maryland.
14. 1972 Annual Book of ASTM Standards, Part 23, Water;
Atmospheric Analvsis, American Society for Testing and
Materials, Philadelphia, Pennsylvania.
15. Canners Directory 1969-70, National Canners Association,
Washington, D.C.
16• The Directory of the Canning^ Freezing, and Preserving
Industries_197.2;7J, 4th Biennial Edition, Edward E.
Judge and Sons, Inc., Westminster, Maryland, 1972.
17. Frozen Food Pack Statistics 1972, American Frozen Food
Institute, Washington, D.C.
18. Standard Industrial Classification Manual 1972, Execu-
tive office of the President, Office of Management and
Budget, Statistical Policy Division, Washington, D.C.
19. Standard Methods for the Examination of Water and
Wastewater, 13th Edition, American Public Health Asso-
ciation, American Water Works Association, and Water
Pollution Control Federation, Washington, D.C. 1971.
20. Water Quality and Treatment, The American Water Works
Association, Inc., 3rd Edition, McGraw-Hill Book Co.,
New York.
PUBLICATIONS
1. Allen, Thomas S. and Kingsbury, Robert P., The Physio-
logical Design of Biological Towers, 28th Annual Purdue
Industrial Waste Conference, May 2, 1973.
2. Cochrann, M. W., Burn, R. J., and Dostal, K. A.,
Cannery Wastewater Treatment with Rotating Biological
Contactor and Extended Aeration, Pro. Element 1 B2037,
EPAORM, USGPO, Washington, oTcT, April 1973.
3. Dostal, K.A., Aerated Lagoon Treatment of Food Pro-
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cessing Wastes, EPAWQO, Project No. 12060, USGPO,
Washington, D.C. , March 1968.
4. Dostal, K. A., Secondary Treatment of Potato Processing
Wastes, EPAWQO/"project No. 12060, USGPO, Washington,
D.~C., July 1969.
5. Eckenfelder, W. W., Jr., Woodward, Charles, Lawler, John, and
Spinna, Robert, Study of Fruit and vegetable Processing Waste
Disposal Methods in the Eastern Region, USDA, Contract No.
12-14-100-482 (73), September 1958.
6. Eilero, R. G. and Smith, R., Wastewater Treatment Plant
Cost Estimating Program, EPAWQO, Cincinnati, Ohio,
April"1971.
7. Esvelt, L. A., Aerobic Treatment of Fruit. Processing
Wastes, Federal Water Pollution Control Administration,
USDI, Grant No. 12060, October 1969.
8. French, R. T., Company, Aerobic Secondary Treatment of Potato
Processing Wastes, EPAWQO, Project No. 12060, EHV, WPRD 15-01-68,
Washington, D. C., December 1970.
9. Guttormsen, K. and Carlson, D. A., Current Practice in
Potato Processing Waste Treatment, FWPCA, USDI, Grant
No. WP-01486-01, October 1969.
10. Law, J. P., et al. Nutrient Removal From Cannery Wastes
by Spray Irrigation of Grassland, FWPCA, USDI, Water Pollution
Control Research Service 16080, Washington, D.C.,
November 1969.
11. Mercer, W. A. and Somers, I. I., Chlorine in Food Plant
Sanitation. Western Research Lab.7 National Canners
Association (NCA) , Berkeley, California.
12. Stevens, Michael R., Elazar, Daniel J., and Schlesinger, Jeanne, Green
Land-Clean Streams, Center for the Study of Federalism, Temple
University, Philadelphia, Pennsylvania, 1972.
13. Winter Garden Citrus Products Cooperative, Complete Mix Activated
Sludge Treatment of Citrus Process Wastes. EPAORM, Grant No. 12060, EZY,
Washington, D.C., August 1971.
14. Gallup, James D., Investigation of Filamentous Bulking in the Activated
Sludge Process, University of Oklahoma, Norman, Oklahoma, August, 1971.
185
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SECTION XIV
GLOSSARY
The definitions given herein are not intended to be complete and exact
scientific or engineering definitions, but are correct as generally used
or understood in the Food Processing Industry.
Acid: Mostly citric acid in citrus fruit; expressed as percent by
weight or milligrams per 100 ml.
Activated_Sludge: Sludge floe produced in raw or settled waste water by
the growth of bacteria and other organisms in the presence of dissolved
oxygen and accummulated in sufficient concentration by returning floe
previously formed.
Activated Sludge Process; A biological waste water treatment process in
which a mixture of waste water and activated sludge is agitated and
aerated. The activated sludge is subsequently separated from the
treated waste water (mixed liquor) by sedimentation and wasted or
returned to the process as needed.
Aeration: The bringing about of intimate contact between air and waste
water by bubbling air through the liquid, mechanically agitating the
liquid to promote surface absorption of air, or spraying the waste water
in the air.
Aerator: A device used to promote aeration. Typically of a motor
driven propeller design; however, many types are available.
Aerobic: Living or active only in the presence of free oxygen.
Air Pollution: The presence in the atmosphere of one or more air
contaminants in quantities, of characteristics, and of a duration,
injurious to human, plant, animal life, or property, or which
unreasonably interfered with the comfortable enjoyment thereof.
Alcjae; Major group of lower plants, single and multi-celled, usually
aquatic and capable of synthesizing their foodstuff by photosynthesis.
Alkalinity; The capacity of water to neutralize acids, a property
imparted by the water's content of carbonates, bicarbonates, hydroxides,
and occasionally borates, silicates, and phosphates. It is expressed in
milligrams per liter of equivalent calcium carbonate.
Ariaerobic: Living or active in the absence of free oxygen.
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er : A type of condenser which allows vapors to be
condensed at a pressure of less than one atmosphere. Because it has a
long vertical bottom pipe, the pipe is often called a barometric leg.
jy:°I°2ical_Filter: A b6^ °f gravel, broken stone, special plastic, or
other medium through which waste water flows or trickles and is
stabilized by the biological action of bacteriological growths living on
the filter media. Also called a trickling filter.
Biological Oxidation: The process whereby, through the activity of
living organisms in an aerobic environment, organic matter is converted
to more biologically stable matter.
Biological Stabilization: Reduction in 'the net energy level or organic
matter as a result of the metabolic activity of organisms, so that
further biodegradation is very slow.
Biol o3ical__Treatment : Organic waste treatment in which bacteria and/or
biochemical action are intensified under controlled conditions.
Slowdown: A discharge from a system, designed to prevent a buildup of
some material, as in a bciler to control dissolved solids.
BOD; Biochemical Oxygen Demand (BOD 5-day) . The quantity of oxygen
used in the biochemical oxidation of organic matter in a specified time,
(usually 5 days) , at a specified temperature, and under specified
conditions.
S£ix: A scale for indicating percent sugar by weight in a juice or
solution. 10° Brix = 10 percent sugar by weight.
Carbon ___ Adsorption: The separation of small waste particles and
molecular species, including color and odor contaminants, by attachment
to the surface and open pore structure of carbon granules or powder.
The carbon is usually "activated", or made more reactive by treatment
and processing.
Category. __ and __ Subcateqory; Divisions of a particular industry which
possess different traits that affect raw waste water quality.
Caustic: Capable of destroying or eating away by chemical action.
Applied to strong bases such as NaOH.
§ : A mechanical device in which centrifugal force is used to
separate solids from liquids and/or separate liquids of different
densities.
Chemical _ Precipit at ion : A waste treatment process whereby substances
dissolved in the waste water stream are rendered insoluble and form a
solid phase that settles out or can be removed by flotation techniques.
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Chlorination; The addition of minute amounts of chlorine to water or
treated waste water to kill bacteria contained therein.
£d.L citrus Peel (Dried! ; Chopped peel, seeds and other
non- juice parts of"~the fruit that have been limed and dried for cattle
feed.
£IS£i£i£Sii2D 5 The process of removing undissolved materials from a
liquid. Specifically, removal of solids either by settling or
filtration.
Clarifier: A settling basin for separating settlable solids from waste
water.
Cm; Centimeter.
Coagulant; A material, which, when added to liquid wastes or water,
creates a reaction which forms insoluble floe particles that adsorb and
precipitate colloidal and suspended solids. The floe particles can be
removed by sedimentation. Among the most common chemical coagulants
used in sewage treatment are ferric sulfate and alum.
Coagulation; The destabilization and initial aggregation of colloidal
and finely divided suspended matter by the addition of a floe-forming
chemical or by biological process.
COD; Chemical oxygen demand. Its determination provides a measure of
the oxygen demand equivalent of that portion of matter in a sample which
is susceptible to oxidation by a strong chemical oxidant. Obtained by
reacting the organic matter in the sample with oxidizing chemicals under
specified conditions.
Cold __ Pressed __ Oil; Essential oil from citrus peel obtained without the
use of heat.
£2ii£°.£!D_b§t e£ia ; Bacteria perdominantly inhabiting the intestines of
man or animal, but occasionally found elsewhere. Their presence in water
is evidence of contamination by fecal material.
Com]D,letely. __ Mixed __ Activated __ Sludcfe; Treatment system in which the
untreated waste water is instantly mixed throughout the entire aeration
basin.
Cooling __ Tower; A device for cooling water by spraying in the air or
trickling over slats .
£2i3Di§££J3££®Qi • Flow of wash or process water in opposition to flow of
product so that the product encounters increasingly cleaner water.
Cull; Product rejected because of inferior quality.
189
-------
£S£i°li: Removal of oxygen from products (juices or apple slices) to
prevent adverse effects en properties of the products.
Decant __ Water: Water from which a top layer of D-limonene is skimmed
off, obtained usually from molasses evaporator condensate (citrus
process) .
2§Hi££i£i£^£i°Ii: Tne process involving the facultative conversion by
anaerobic bacteria of nitrates into nitrogen and nitrogen oxides.
De^ilincj: Removal of oil from produce juices.
De^sludge: A centrifuge designed to remove the coarse particles from a
peel oil emulsion.
Detention __ Time: Period of time required for a liquid to flow through a
tank or unit.
Digestion: The biological decomposition of organic matter in sludge,
resulting in partial gasification, liquefaction, and mineralization.
Disintegrate; To break or reduce into component parts or particles,
e.g., the rupture of potato cells for starch processing.
SiSSSiXS^—^il—IliSfe^iSB1 A process involving the compression of air and
liquid, mixing to super- saturation, and releasing the pressure to
generate large numbers of minute air bubbles. As the bubbles rise to
the surface of the water, they carry with them small particles that they
contact. The process is particularly effective for grease removal.
D-limonene: Major constituent of peel oil. Sometimes used synonymously
with stripper oil.
Dr ai n^ti le : Pipes of various materials with perforations or open joints
laid in underground trenches and fills to collect and carry off
subsurface water.
Effluent: Wastewater or other liquid, partially or completely treated
or untreated, flowing out of a process operation, processing plant,
reservoir, basin, or treatment plant.
§ : A physical separation process which uses membranes and
applied voltages to separate ionic species from water.
En^yjne: A catalyst produced by living cells that accelerates specific
transformation of material, as in the digestion of food.
Esse ntia l_Oi 1 : The oil in citrus peel, peel oil.
190
-------
Applies to lake or pond - becoming rich in dissolved
nutrients, with seasonal oxygen deficiencies.
E¥§2°J£!iiy.§ __ Condensers; Equipment used to condense hot vapors wherein
water is circulated over coils containing the vapors. Part of the water
evaporates in the air, enhancing the cooling effect.
Evaoorator: Equipment used to remove water from juice or press liquor,
usually by boiling in a vacuum, and condensing the vapors.
Evapgtransgir ation : Water withdrawn from the soil by evaporation and
plant transpiration.
Exhaust: Heating of food in cans prior to closing the cans to force air
out of the containers.
Extended_AeratiQn; A form of the activated sludge process except that
the retention time of waste waters is one to three days.
Facultat ive__Bacte ri a : Bacteria which can exist and reproduce under
either aerobic or anaerobic conditiors.
Facultative __ Decomposition: Decomposition of organic matter by
facultative microorganisms.
Facultative __ Pond; A combination aerobic- anaerobic pond divided by
loading and thermal stratification into aerobic surface, and anaerobic
bottom, strata.
Feed: A material which flows into a containing space or process unit.
ESLSQSH^siii0!!1 Changes in organic matter brought about by microorganisms
growing in the absence of air.
Filtrate; Liquid after passing through a filter.
Filtration; Removal of solid particles from liquid or particles from
air or gas stream by passing the liquid or gas stream through a
permeable membrane.
Fl.oc: A mass formed by the aggregation of a number of fine suspended
particles.
Tne process of forming larger masses from a large number
of finer suspended particles.
Floe __ Skimmings; The flocculent mass formed on a quieted liquid surface
and removed for use, treatment, or disposal.
191
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Pluming: In-plant transportation of product or waste material through
water conveyance.
Industrial Wastewater: Flow of waste liquids from industries using
large volumes of water from processing industrial products, such as food
processing plants.
Influent: A liquid which flows into a containing space or process unit.
i2S_S2£ll5Q2§: A reversible chemical reaction between a solid and a
liquid by means of which ions may be interchanged between the two. It
is in common use in water softening and water deionizing.
Kg: Kilogram or 1,000 grams, metric unit of weight.
Kjeldahl_Nitrogen: A measure of the total amount of nitrogen in the
ammonia and organic forms in waste water.
KWH: Kilowatt-hours, a measure of total electrical energy consumption.
Lagoon: A large pond used to hold waste water for stabilization by
natural processes.
Leach: To subject to the action of percolating water or other liquid in
order to separate soluble components. To cause water or other liquid to
percolate through.
Leaching: The removal of soluble constituents from soils or other
materials by percolating water.
Lime: Calcium oxide, a caustic white solid, which forms slaked lime
(calcium hydroxide) when combined with water. It is used for pH control
and other waste treatment pruposes.
Lye; A strong alkaline solution. Caustic soda (sodium hydroxide) is
the most common lye.
Lv.e Dump: The spent water from the lye bath that is used to remove the
inner membrane of sectionizing fruit. The spent lye solution is
discharged periodically.
Lv.e Rin.se: The rinse water used to remove from the fruit, lye solution
carried out of the lye bath in sectionizing operations.
M: Meter, metric unit of length.
Make-up Water; Fresh water added to process water to replace system
losses.
Mean: The average value of a number of observed data.
192
-------
MGD: Million gallons per day.
Ma/1: Milliongrams per liter; approximately equals parts per million; a
term used to indicate concentration of materials in water.
Microstrainer/microscreen: A mechanical filter consisting of a
cylindrical surface of metal filter fabric with openings of 20-60
micrometers in size.
Mixed Liquor [ML]_: A mixture of sludge and waste water in a biological
reaction tank undergoing biological degradation in an activated sludge
system.
Molasses; A dark-colored syrup containing non-sugars produced by
evaporating press liquor and other strong wastewater to about 70 percent
dissolved solids. Molasses is used as commercial cattle feed or in the
manufacture of monosodium glutamate, a food flavoring agent, alcohol,
yeast, citric acid and other products.
mm: Millimeter = 0.001 meter.
Municipal Treatment: A city or community-owned waste treatment plant
for municipal and, possibly, industrial waste treatment.
Neutralize: To adjust the pH of a solution to 7.0 (neutral) by the
addition of an acid or a base.
Nitratex_Nitrite: Chemical compounds that include the NO - (nitrate)
and NO - (nitrite) ions. They are composed of nitrogen and oxygen, are
nutrients for growth of algae and other plant life, and contribute to
eutrophication.
Nitrif_j.cation: The process of oxidizing ammonia by bacteria into
nitrites and nitrates.
No_Dis>charc[e: No discharge of effluents to a water course. A system of
land disposal with no runoff or total recycle of the waste water may be
used to achieve it.
Non-Water Quality; Thermal, air, noise and all other environmental
parameters except water.
Nutrients; Compounds that promote biological growth, e.g., phosphorus
and nitrogen. Usually undesirable in treated effluent; however, they
are required in proper proportions for successful biological waste
treatment.
Organic Content: Synonymous with volatile solids except for small
traces of some inorganic materials such as calcium carbonate which will
lose weight at temperatures used in determining volatile solids.
193
-------
Oxidation Lagoon; Synonymous with aerobic or aerated lagoon.
Oxidation Pond: Synonymous with aerobic lagoon.
Oxygen __ UB£ake_Ra£e: Oxygen utilization rate or rate at which oxygen is
used by bacteria in the decomposition of organic matter.
The highest average daily flow occurring throughout a period
of time.
Percolation; The movement of water through the soil profile.
£>H: A measure of the relative acidity or alkalinity of water. A pH
value of 7.0 indicates a neutral condition; less than 7 indicates a
predominance of acids, and greater than 7, a predominance of alkalis.
There is a 10-fold increase (or decrease) from one pH unit level to the
next, e.g., 10-fold increase in alkalinity from pH 8 to pH 9.
£2iisher; A centrifuge designed to separate peel oil from its emulsion.
A substance which taints, fouls, or otherwise renders impure
or unclean the recipient system.
Tne presence of pollutants in a system sufficient to degrade
the quality of the system.
® __ Chemicals; High molecular weight substances which
dissociate into ions when in solution; the ions either being bound to
the molecular structure or free to diffuse throughout the solvent,
depending on the sign of the ionic charge and the type of electrolyte.
They are often used as flocculation agents in waste water treatment,
particularly along with dissolved air flotation.
Pomace; Pulpy substance of fruit and vegetables after grinding and
juicing.
Ponding; A waste treatment technique involving the actual holdup of all
waste waters in a confined space with evaporation and percolation the
primary mechanisms operating to dispose of the water.
Parts per million, a measure of concentration, expressed currently
as mg/1.
Precipitation; The phenomenon that occurs when a substance held in
solution in a liquid passes out of solution into solid form.
liquid obtained when citrus peel is chopped, treated
with lime, and pressed or squeezed.
194
-------
Pre treatment; Wastewater treatment located on the plant site and
upstream from the discharge to a municipal treatment system.
^igJfg 3'¥ea'tmgryt : In -plant by-product recovery and waste water
treatment involving physical separation and recovery devices such as
catch basins, screens, and dissolved air flotation.
Process: A series of actions or operations conducted to an end.
Process E^f^ugnt^or.^ Discharge ; The volume of water emerging from a
particular use in the plant.
Process __ Water; Water which is used in the internal juice streams from
which sugar is ultimately crystallized.
Proteiijase: An enzyme which hydro lyzes proteins.
RjLW_Tgn: One ton of unprocessed commodity.
Raw_Waste: The waste water effluent from the in-plant primary waste
treatment system.
B§£y,£l§: Tne return of a quantity of effluent from a specific unit or
process to the feed stream of that same unit. This would also apply to
return of treated plant waste water for several plant uses.
Refir ejeatati ve_gajtjEie ; A sample of the same composition as the thing it
represents.
Retort; The heating of canned foods after closing to sterilize the
product.
S§2Z§£S§_2§212Si§: Tne physical separation of substances from a water
stream by reversal of the normal osmotic process; i.e., high pressure,
forcing water through a semi -permeable membrane to the pure water side
leaving behind more concentrated waste streams.
Sand _ Filter: A filter device incorporating a bed of sand that,
depending on design, can be used in secondary or tertiary waste
treatment.
Scalder __ Discharge: Hot water used to soften the peel of fruit before
sect ionizing.
Sc al ding : Treatment with steam at high temperatures.
Screening! The removal of relatively coarse floating and suspended
solids from waste water by straining through racks and screens.
195
-------
Secondary __ Treatment; The waste treatment following primary in-plant
treatment, typically involving biological waste reduction systems.
Sedimentation: The falling or settling of solid particles in a liquid,
as a sediment.
Semi perm eabl e __ Membrane: A thin sheet- like structure which permits the
passage of solvent but is impermeable to dissolved substances.
S e tt leab le_S olids : Suspended solids which will settle in sedimentation
basins (clarifiers) in noriral detention times.
Sett ling Tank; Synonymous with "Sedimentation Tank".
Water after it has been fouled by various uses. From the
standpoint of source it may be a combination of the liquid or water-
carried wastes from residences, business buildings, and institutions,
together with those from industrial and agricultural establishments, and
with such groundwater, surface water, and storm water as may be present.
Shock_Load: A quantity of waste water or pollutant that greatly exceeds
the normal discharged into a treatment system, usually occurring over a
limited period of time.
Sizincj: The process of cutting and trimming the product.
(1) The accumulated solids separated from liquids, such as
water or waste water, during processing, or deposits on bottoms of
streams or other bodies of waters. (2) The precipitate resulting from
chemical treatment, coagulation, or sedimentation of water or waste
water.
Slurry.: A mixture of water with finely divided suspended solids.
Solute: A dissolved substance.
Term used to signify waste water treatment systems that have a
low pH value. The acid condition is favorable to growth of organisms
which produce foul smelling by-products, hence is undesirable.
Standard __ Deviation; A measure of the variation of data values around
the mean.
Stoichigmet ric^Amoun t : The amount of a substance involved in a specific
chemical reaction, either as a reactant or as a reaction product.
Strength: The relative total concentration in effluent of BOD, COD, TSS
(albuminoids, amino acids, pectins and sugars) , alkalinity and acidity.
196
-------
SS: Suspended Solids. (1) Solids that either float on the surface of,
or are in suspension in water, waste water, or other liquids, and which
are largely removable by laboratory filtering. (2) The quantity of
material removed from waste water in a laboratory test, as prescribed in
"Standard Methods for the Examination of Water and Wastewater" and
referred to as nonfilterable residue.
St rijojDer _Oi 1: Mostly d-limonene obtained from molasses evaporator
condensate by decantation.
Substrate: Raw waste feed on which a microorganism grows or is placed
to grow by decomposing the waste material.
§iik§ir.sl££_B§!Bo.y£i: Tne "total BOD in plant effluent, minus the soluble
BOD in plant effluent, divided by the total influent BOD.
Sulf itincr; Exposing sized fruit to sulfur dioxide atmosphere or
solution for stabilizing color, flavor, and texture.
SUESJEDi&lDt: The layer floating above the surface of a layer of solids.
Surcharge: An additional service charge imposed upon industry by a
municipality for discharge of waste water to the municipal sewer system
in excess of some previously specified volume and/or character.
Surface Water: The waters of the United States including the
territorial seas.
Sy,rup: Water solution of sugar, usually sucrose.
Tertiary Waste Treatment: Waste treatment systems used to treat
secondary treatment effluent and typically using physical-chemical
technologies to effect waste reduction. Synonymous with "Advanced Waste
Treatment".
Total Dissolved Solids (TDS) : The total amount of dissolved material,
organic and inorganic, contained in water or wastes. Excessive
dissolved solids can make water unsuitable for industrial uses and
unpalatable for drinking.
TOG: Total organic carbon. A test expressing waste water contaminant
concentration in terms of the carbon content.
Total Suspended solids (TSS11 ; See Suspended Solids.
Trickling Filter; See Biological Filter.
Vector: A carrier of pathogenic organisms.
197
-------
-------
APPENDIX A
APPLES - INFORMATION FROM PROCESSING PLANTS
Plant
Code
AP-101
AP-102
AP-103
Plant Capacity
kkg/hr (T/hr)
29.02
27.21
21.41
32.0
30.0
23.6
AP-104
AP-105
AP-106
AP-107
AP-108
AP-109
AP-110
AP-111
AP-112
AP-113
AP-114
AP-115
AP-116
AP-117
AP-118
AP-119
AP-120
AP-121
AP-122
AP-123
AP-124
AP-125
AP-126
AP-127
13.
20.
24.
15.
18.
-
-
4.
2.
7.
43.
13.
38.
25.
1.
-
—
15.
4.
21.
20.
-
8.
-
61
41
31
87
14
08
72
26
08
97
91
94
36
9
54
77
41
61
15.
22.
26.
17.
20.
-
-
4.
3.
8.
47.
15.
42.
28.
1.
-
—
17.
5.
24.
22.
-
9.
-
0
5
8
5
0
5
0
0
5
4
9
6
5
5
0
0
5
5
Products
Sauce & Juice
Sauce & Juice
Sauce, Juice & Vinegar
Sauce & Slices
Sauce, Slices & Juice
Slices & Vinegar
Sauce & Juice
Sauce, Slices & Juice
Slices
Sauce
Pie Filling
Slices
Slices & Sauce
Sauce, Juice & Vinegar
Sauce & Juice
Sauce & Juice
Slices, Sauce, Juice
& Vinegar
Slices
Sauce & Juice
Sauce
Sauce
Sauce
Slices & Sauce
Juice
Sauce
Slices & Sauce
Slices
Method of Treatment
Aerated Lagoon
Land Disposal Spray Irrigation
after Secondary Treatment
Land Disposal Spray Irrigation
after Secondary Treatment
Land Disposal Spray Irrigation
Land Disposal Spray Irrigation
Lagoons
Municipal Sewer
Land Disposal Irrigation
Municipal Sewer
Land Disposal Irrigation
Land Dispodal Spray Irrigation
& Municipal Sewer
Land Disposal Spray Irrigation
Land Disposal Spray Irrigation
Municipal Sewer
Aerated Lagoons
Land Disposal Spray Irrigation
Land Disposal Spray Irrigation
Municipal Sewer
Land Disposal Ponds
Municipal Sewer
Municipal Sewer
-------
(Continued)
APPLES - INFORMATION FROM PROCESSING PLANTS
ro
o
o
Plant
Code
AP-128
AP-129
AP-130
AP-131
AP-132
AP-133
AP-134
AP-135
AP-136
AP-137
AP-138
AP-139
AP-140
AP-141
AP-142
Plant Capacity
kkg/hr (T/hr)
4.54
3.63
5.44
4.54
4.99
4.08
1.81
4.54
31.00
6.36
12.50
10.88
4.1
5.0
4.0
6.0
5.0
5.5
4.5
2,
5
34.2
7.0
13.8
12.0
Products
Sauce
Vinegar
Sauce
Dehydrated Pieces
Sauce & Juice
Juice
Sauce
Slices
Juice
Slices & Juice
Slices & Dices
Sauce, Slices & Juice
Slices
Juice
Dehydrated Slices
Method of Treatment
Municipal Sewer
Land Disposal Irrigation
Land Disposal Irrigation
Land Disposal System
Aseptic Pond (Closed)
Aseptic Pond (Closed)
Municipal Sewer
Municipal Sewer
Municipal Sewer
Municipal Sewer
Municipal Sewer
Municipal Sewer
Activated Sludge
Municipal Sewer
Municipal Sewer
-------
CITRUS - INFORMATION FROM PROCESSING PLANTS
ro
o
Plant
Code
CI-101
CI-102
CI-103
CI-104
CI-105
CI-106
CI-107
CI-108
CI-109
CI-110
CI-111
CI-112
CI-113
CI-114
CI-115
Plant Capacity
kkg/D (T/D)
145.8
1,229.0
317.5
1,133.8
2,267.5
2,086.1
1,088.4
3,412.1
2,875.1
2,875.1
1,836.8
326.5
3,673.4
2,448.9
1,836.8
160.5
1,335.0
350.0
1,250.0
2,500.0
2,300.0
1,200.0
3,762.0
3,150.0
3,150.0
2,025.0
360.0
4,050.0
2,700.0
2,025.0
Products
Juice, Oil/Peel-Pulp
By-Products
Juice, Oil/Peel-Pulp
By-Products,
Juice, Oil/Peel-Pulp
By-Product,
Pectin/Pharmaceuticals
Juice, Segments
Juice, Oil/Peel
By-Products
Juice, Oil/Peel
By-Products
Juice, Oil
Juice, Segments
Peel-Pulp By-
Juice, Oil/Peel
By-Products
Juice, Oil/Peel
By-Products
Juice, Oil/Peel
By-Products
Juice
Juice, Segments
Peel-Pulp By-
Juice, Oil/Peel
By-Products
Juice, Oil/Peel
By-Products
-Pulp
-Pulp
, Oil/
Products
-Pulp
-Pulp
-Pulp
, Oil/
Products
-Pulp
-Pulp
Method of Treatment
Municipal Sewers,
Land Disposal Irrigation & Ocean
Brine Line
Land Disposal Irrigation
Aerated Tanks, Clarifier,
Trickling Filter
Aerated Lagoon &
Land Disposal Irrigation
Aeration, Clarification
Land Disposal Irrigation
Activated Sludge
Land Disposal Irrigation
Aerated Lagoon &
Land Disposal Irrigation
Municipal Sewer &
Land Disposal Irrigation
Lagoons, Land Disposal Irrigation
Municipal Sewer
Municipal Sewer
Land Disposal Irrigation
Land Disposal Irrigation
(Continued)
-------
o
ro
(Continued)
CITRUS - INFORMATION FROM
Plant Plant Capacity
Code kkg/D (T/D)
PROCESSING PLANTS
Products
CI-116 1,224.5 1,350.0
CI-117 571.4 630.0
CI-118 743.7 820
CI-119 5,714.1 6,300.0
CI-120 308.4 340.0
CI-121 3,174.5 3,500.0
CI-122 1,020.4 1,125.0
CI-123 3,809.4 4,200.0
CI-124 408.2 450.0
CI-125 29.0 32.0
CI-126 5,079.2 5,600.0
CI-127 226.8 250.0
CI-128 285.7 315.0
CI-129 1,732.4 1,910.0
CI-130 1,142.8 1,260.0
CI-131 689.3 760.0
CI-132 453.5
500.0
Juice, Peel-Pulp
By-Products
Juice, Oil/Peel-Pulp
By-Products
Juice, Segments
Peel-Pulp By-Products
Juice, Oil/Peel-Pulp
By-Products
Juice, Oil/Peel-Pulp
By-Products
Juice, Oil/Peel-Pulp
By-Products
Juice, Oil
Juice, Oil/Peel-Pulp
By-Products
Juice
Segments
Juice, Peel-Pulp
By-Products
Segments
Juice, Oil/Peel-Pulp
By-Products
Juice, Segments, Oil/
Peel-Pulp By-Products
Juice, Segments, Oil
Juice, Oil, Pectin
Juice, Oil
Method of Treatment
Municipal Sewer
Land Disposal Irrigation
Aerated Lagoons
Aerated Lagoons
No Treatment
Land Disposal Irrigation
Land Disposal Irrigation,
Municipal Sewer
Aeration, Clarification
Municipal Sewer
Municipal Sewer
No Treatment
Trickling Filter, Aeration
Land Disposal Irrigation
Activated Sludge
Land Disposal Irrigation
Land Disposal Irrigation &
Oil Brine Line
Municipal Sewer
(Continued)
-------
(Continued)
CITRUS - INFORMATION FROM PROCESSING PLANTS
o
co
Plant
Code
CI-133
CI-134
CI-135
CI-136
CI-137
CI-138
CI-139
CI-140
CI-1A1
CI-142
CI-143
CI-144
CI-145
CI-146
CI-147
CI-148
CI-149
Plant Capacity
kkg/D (T/D)
1,020.4 1,125.0
530.6
86.2
127.0
585.0
95.0
140.0
1,100.0
Products
Juice, Oil
Juice, Oil
Peel-Pulp By-Products
Juice, Oil/Peel-Pulp
Juice, Oil
Juice
Juice, Oil/Peel-Pulp
By-Product
Juice
Juice, Peel-Pulp
By-Products
Juice, Oil
Juice, Peel-Pulp
By-Products
Juice, Oil/Peel-Pulp
By-Products
Juice
Segments
Peel-Pulp By-Products
Juice, Segments
Juice, Oil
Method of Treatment
No Treatment
Municipal Sewer
Land Disposal Irrigation
Municipal Sewer
Municipal Sewer
Land Disposal Irrigation
Land Disposal Irrigation
Aerobic & Anaerobic Digestion
Municipal Sewer
Land Disposal Irrigation
Land Disposal Irrigation
Land Disposal Irrigation
Municipal Sewer
Municipal Sewer
Land Disposal Irrigation
Land Disposal Irrigation
Municipal Sewer
Municipal Sewer
-------
POTATOES - INFORMATION FROM PROCESSING PLANTS
ro
Plant
Code
PO-101
PO-102
PO-103
PO-104
PO-105
PO-106
PO-107
PO-108
PO-109
PO-110
PO-111
PO-112
Plant Capacity
kkg/D (T/D)
1,133.8
1,633.6
544.2
435.4
-
-
544.2
634.9
1,043.1
317.5
725.6
907.0
1,250
1,800
600
480
-
-
600
700
1,150
350
800
1,000
Products
French Fries, Dehydrated
Flakes & Granules
French Fries, Dehydrated
Flakes & Granules
French Fries
Dehydrated Products
Dehydrated Products
French Fries
Dehydrated Granules &
Slices
French Fries
French Fries
French Fries &
Hash Browns
French Fries &
Potato Wedges
French Fries, Hash
Method of
Activated
Spray
Activated
Spray
Activated
-
-
-
Activated
Activated
Activated
Treatment
Sludge &
Sludge &
Sludge
Sludge
Sludge
Sludge
Land Disposal
Land Disposal
Aerated Lagoon
Land Disposal Spray
Land Dispc
>sal Ponds
Irrigation
Browns & Dehydrated Flakes
(Continued)
-------
(Continued)
POTATOES - INFORMATION FROM PROCESSING PLANTS
ro
o
in
Plant
Code
PO-113
PO-114
PO-115
PO-116
PO-117
PO-118
PO-119
PO-120
PO-121
PO-122
PO-123
PO-124
PO-125
PO-126
PO-127
PO-128
Plant C
kkg/D
498.9
453.5
217.7
453.5
562.3
127.0
72.6
272.1
272.1
340.1
226.8
294.8
340.1
90.7
453.5
136.1
PO-129
181.4
(T/D)
550
500
240
500
620
140
80
300
300
375
250
325
375
100
500
150
200
Products
Dehydrated Granules
Dehydrated Granules
Dehydrated Flakes
Frozen French Fries
Frozen French Fries
Frozen French Fries
Frozen French Fries
Frozen French Fries
Dehydrated
Dehydrated
Dehydrated
Dehydrated
Frozen French Fries
Starch
Frozen French Fries
Frozen French Fries &
Dehydrated Products
Frozen French Fries
Method of Treatment
Land Disposal Spray Irrigation
Land Disposal Flood Irrigation
Activated Sludge
Land Disposal Spray Irrigation
Municipal Sewer
Land Disposal Spray Irrigation
Activated Sludge
Activated Sludge
Aerated Lagoons
Municipal Sewer
Land Disposal Spray Irrigation
Anaerobic Pond
Municipal Sewer
River
Land Disposal Spray Irrigation
Activated Sludge, Aerated Lagoon
Trickling Filter
Aerobic Lagoon
-------
(Continued)
POTATOES - INFORMATION FROM PROCESSING PLANTS
CT>
Plant
Code
PO-130
PO-131
PO-132
PO-133
PO-134
PO-135
PO-136
Plant C
kkg/D
544.2
362.8
430.8
163.3
45.4
312.9
589.6
apaci
(T/;
600
400
475
180
50
345
650
Products
Frozen French Fries
Frozen French Fries
Dehydrated Granules
Dehydrated Flakes
Sealed Plastic Bag
Dehydrated Flakes
Dehydrated Flakes,
Granules & Dices
Method of Treatment
Land Disposal Spray Irrigation
Land Disposal Spray Irrigation
Land Disposal Spray Irrigation
Land Disposal Spray Irrigation
Aerated Lagoons
Municipal Sewer
Activated Sludge Land Disposal
Spray
-------
APPLES - PRODUCT CLASSIFICATION BY SIC CODE
SIC PRODUCT CODE
2033
0 00
0 02
1
1 12
1 13
1 14
1 61
4
4 11
4 85
4 89
4 91
2034
0 00
0 02
1
1 21
2037
0 00
0 02
1
1 55
1 95
PRODUCT
Canned Fruits and Vegetables
For companies with 10 or more employees
For companies with less than 10
employees
Canned Fruits (except baby foods)
Apples, excluding pie mix
Applesauce - 372 gm. to 511 gm.
(13.1 oz. to 18 oz.)
Applesauce - other sizes
Canned fruit pie mix - apple
Canned fruit juices & concentrates
Apple juice
Fruit juices, concentrated, hot pack
- 116 gm. to 119 gm.(4.1oz. to 7oz.)
Fruit juices, concentrated, hot pack
- Other sizes and bulk
Fruit juices, fresh, to be kept under
refrigeration
Dehydrated Fruits and Vegetables and
Soup Mixes
For companies with 10 or more employees
For companies with less than 10
employees
Dried fruits and vegetables, except soup
mixes
Apples
Frozen Fruits and Vegetables
For companies with 10 or more employees
For companies with less than 10
employees
Frozen fruits, juice and ades
Apples and applesauce
Apple frozen fruit juice concentrate
Source: Standard Industrial Classification Manual (1972,
Office of Management and Budget, Government
Printing Office)
207
-------
CITRUS - PRODUCT CLASSIFICATION BY SIC CODE
SIC PRODUCT CODE
2033
0 00
0 02
1
1 31
1 34
4
4 31
4 42
4 43
4 51
4 53
4 85
4 89
4 91
2037
0 00
0 02
1
1 81
1 82
1 83
1 85
1 86
1 87
Canned Fruits and Vegetables
For companies with 10 or more employees
For companies with less than 10 employees
Canned Fruits (except baby foods)
Grapefruit Segements
Fruit for Salad - Citrus
Canned Fruit Juices & Concentrates
Grapefruit Juice
Orange Juice Single Strength
1.14 kg to 1.7 kg (40.1 oz. to 60 oz.)
Orange Juice Single Strength
Other Sizes
Grapefruit-Orange Juice Blend
Grapefruit-Pineapple Juice Blend
Fruit Juices, Concentrated, Hot Pack
(116 gm to 119 gm (4.1 oz. to 7 oz.)
Fruit Juices, Concentrated, Hot Pack
Other Sizes and bulk
Fruit Juices, Fresh, to be kept under
refrigeration
Frozen Fruits arid Vegetables
For companies with 10 or more employees
For companies with less than 10 employees
Frozen Fruits, Juices and Ades
Orange Juice-116 gm to 199 gm
(4.1 oz. to 7 oz.)
Orange Juice-287 gm to 369 gm.
(10.1 oz. to 13 oz.)
Orange Juice - Other Sizes
Lemonade-116 gm to 199 gm (4.1 oz. to 7 oz.)
Lemonade-287 gm to 369 gm
(10.1 oz. to 13 oz.)
Lemonade - Other Sizes
Source: Standard Industrial Classification Manual (1972)
Office of Management and Budget, Government
Printing Office
208
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POTATOES - PRODUCT CLASSIFICATION BY SIC CODE
SIC PRODUCT CODE
2033
2034
0 00
0 02
2
2 74
^
0 00
0 02
1
1 31
1 35
2037
0 00
0 02
2
2 47
2046
2099
PRODUCT
Canned Fruits and Vegetables
For companies with 10 or more employees
For companies with less than 10 employees
Canned Vegetables (except hominy and
mushrooms)
White potatoes
Dehydrated Fruits and Vegetables and
Soup Mixes
For companies with 10 or more employees
For companies with less than 10 employees
Dried Fruits and Vegetables, Except Soup
Mixes
Potatoes - consumer size - 454 gm. (1 Ib)
and under.
Potatoes - commercial size - over 454 gm.
(1 Ib)
Frozen Fruits and Vegetables
For companies with 10 or more employees
For companies with less than 10 employees
Frozen Vegetables
Potatoes & Potato Products (french fried
patties, puffs, etc.)
Wet corn milling - Potato Starch
Food Preparations, Not Elsewhere Classified
Potato Chips
Source: Standard Industrial Classification Manual (1972)
Office of Management and Budget, Government Printing
Office
209
-------
DATA SUMMARY
APPLE PROCESSING
1. Average Daily Plant Processing Capacity
Tons of Fruit/Hr.
2. Plant Categorization
Canned
a. Sliced
b. Sauce
Frozen
a. sliced
b. Diced
c. sauce
Dehydrated
a. Sliced
b. Diced
Juice
a. Cider or Juice
b. Vinegar Stock
3. Process Equipment
Type of Peeling
Manufacturer
Type of Slicing
Manufacturer
Total
100%
Type of Coring
Manufacturer
Type of Finishing
Manufacturer
210
-------
DATA SUMMARY
CITRUS PROCESSING
1« Average Daily Plant Processing Capacity
Tons of Fruit/Day
2. Plant Categorization
a. Single Strength Juice .
b. Chilled Juice
c. Chilled Segments
d. Concentrated Juice
Total 100%
e. Oranges
f. Grapefruit
g. Lemons and Limes
Total 100%
WASTE EFFLUENT DATA
3. In-Plant & Post Treatment (End-of-Pipe) Waste Effluents
Line
No.
1
2
3
4
5
6
7
8
9
10
11
12
Gal/Min
Percent
Recycled
BOD
COD
Temp.
°P
PH
Total
Solids
'
Suspended!
Solids >
i
•
1
i
i
i
»
..... (
t
!
!
See page No. Three for additional Line Nos.
211
-------
DATA SUMMARY
POTATO PROCESSING
1. Average Daily Plant Processing Capacity
Location of Plant
Tons of Potatoes/Day _
2. Plant Categorization
a. Frozen
French Fries
Hash Browns
Preformed Shapes
b. Dehydrated
Granules
Flakes
Chips
Cubes
c. Canned
Whole
Sliced
d. Other
Total 100%
212
-------
DATA SUMMARY - APPLE PROCESSING
Page Two
WASTE EFFLUENT DATA
4, In-Plant & Post Treatment (End-of-Pipe) Waste Effluents
Line
NO.
i
.,. 2
' 3
1 4
5
" •<;
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
"28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
"44
45
Gal/Min
Percent
Recycled
BOD
COD
•
—
213
Temp.
oF
pH
,
. Total Suspendeq
Solids Solids i
i
i
1
1
1
i
!
i
:
t
i
»
!
i
t
1
1
i
1
t
i
I
i
>
t
.
1
-------
DATA SUMMARY - APPLE PROCESSING
Page Three
5.
6.
7.
8.
9.
10.
12.
Settling Ponds
Number
Screening Equipment
Type
Clarifier
Number
Rotary Vacuum Filters
Number
Aeration Ponds
Number
Land Disposal
Type
T'otal Area
Mesh Opening
Type
Type
Total Area
Total Area
11. Discharge to Municipal Sewer
Daily, Monthly or Yearly Assessment
Total Volume
Screen Area
Size
Size
Size
and Basis of Calculating the Assessment
River and/or Stream
Name
ECONOMIC DATA
13. Construction Cost of Waste Treatment Facility (include laboratory)
14. Operating Cost of Waste Treatment Facility (include laboratory)
•14
-------
Volatiles in Citrus Wastes; Those constituents that can distill over in
anevaporator and collect in the condensate. Chiefly peel oil
constituents and essence from juice.
CONVERSION TABLE
MULTIPLY (ENGLISH UNITS) by conversion factor to
Obtain METRIC UNITS
ENGLISH UNIT
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
galion/minute
horsepower
inches
inches of mercury
pounds
million gallons/day
mile
pound/square
inch (gauge)
square feet
square inches
tons (short)
yard
ABHXEVIA.TJO.N CONVERSION ABBREVIATION
ac
ac ft
BTU
BTU/lb
cfm
cfs
cu ft
cu ft
cu in
Fo
ft
gal
gpm
hp
in
in Hg
Ib
mgd
mi
psig
sq ft
sq in
t
y
0.405
1233.5
0.252
ha
cu m
kg cal
C.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
kg cal/kg
cu m/min
cu m/min
cu m
liters
cu cm
°c
m
liters
I/sec
kw
cm
atm
kg
cu m/day
km
(0.06805 psi +1) * atm
0.0929 sq m
0. 452 sq cm
0.907 kkg
0.9144 m
* Actual conversion, not a multiplier
215
««.«. OOVERNMENT PRINTING OFFICE: 1974 546-317/Z98 1-3
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