xvEPA
United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Cincinnati OH 45268
EPA-600 2-79-009
January 1979
Research and Development
Overview of the
Environmental
Control Measures and
Problems in the
Food Processing
Industries
-------
RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S Environmental
Protectio0 Agency, have been grouped into nine series. These nine broad cate-
gor es were established to facilitate further development and application of en-
v ronmenta.i technology Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The n'ne series are
1 Environmental Health Effects Research
2, Environmental Protection Technology
3 Ecological Research
4 Environmental Monitoring
5. Socioeconomic Environmental Studies
6 Scientific and Technical Assessment Reports (STAR)
7 Interagency Energy-Environment Research and Development
8, "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental degradation from point and non-point sources of pollution. This work
provides the new or improved technology required for the control and treatment
of pollution sources to meet environmental quality standards.
Th s document is avanable to the public through the National Technical Informa-
t on Service. Sprngt'e d Virginia 22161
-------
EPA-600/2-79-009
January 1979
OVERVIEW OF THE ENVIRONMENTAL
CONTROL MEASURES AND PROBLEMS
IN THE FOOD PROCESSING INDUSTRIES
by
J. L. Jones
M. C. T. Kuo
P. E. Kyle
S. B. Radding
K. T. Semrau
L. P. Somogyi
SRI International
Menlo Park, California 94025
Grant No. R804642-01
Project Officer
Kenneth Dostal
Food and Wood Products Branch
Industrial Environmental Research Laboratory
Cincinnati, Ohio 45268
INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
-------
DISCLAIMER
This report has been reviewed by the Industrial Environmental
Research Laboratory, U.S. Environmental Protection Agency, and approved
for publication. Approval does not signify that the contents neces-
arily reflect the views and policies of the U.S. Environmental Protec-
tion Agency, nor does mention of trade names or commercial products con-
stitute endorsement or recommendation for use.
ii
-------
FOREWORD
When energy and material resources are extracted, processed, converted,
and used, the related pollutional impacts on our environment and even on
our health often require that new and increasingly more efficient pollution
control methods be used. The Industrial Environmental Research Laboratory-
Cincinnati (lERL-Ci) assists in developing and demonstrating new and
improved methodologies that will meet these needs both efficiently and
economically.
The report assesses the pollution sources and control measures uti-
lized by the food processing industries, the water pollution control,
air pollution control and solid waste management practices of 19 specific
segments of the food processing industry. An attempt was made to identify
potential toxic substances emission problems.
David G. Stephan
Director
Industrial Environmental Research Laboratory
Cincinnati
iii
-------
PREFACE
This report has been prepared by SRI International for the Food and
Wood Products Branch of the Industrial Environmental Research Laboratory
in Cincinnati, Ohio, under EPA Grant No. R804642-01-2. This document is
not intended to be a definitive work on food processing technology or
environmental control in the food industries. It is rather to serve as
an informational document for EPA staff members responsible for planning
research and development programs for the food industries, for regulatory
policy planning and review, and for enforcement activities. It has been
assumed that many users of this document will have had no prior experience
with or exposure to the food processing industries. An effort has there-
fore been made to present data in summary form on the industry size and
structure, degree of integration, financial structure, as well as to pre-
sent technical data on production processes and environmental control
processes or methods. A unit operations approach has been used in pre-
senting the descriptive matter on production processes.
The groups at SRI responsible for the preparation of this document
include:
o Food and Agrosciences Department (L.P. Somogyi)
o Food and Agricultural Industries Department (P.E. Kyle)
o Chemical Engineering Laboratory (J.L. Jones, M.C.T. Kuo,
S.B. Radding, and K.T. Semrau).
The body of the report and Appendices A-H were prepared by the
staff members of the Chemical Engineering Laboratory. Staff members
from the Food and Agrosciences Department and the Food and Agricultural
Industries Department prepared the statistical information, industry
descriptions, and discussion of processes in Appendices 1-18.
IV
-------
ABSTRACT
In conducting the assessment of the pollution sources and control
measures utilized by the food processing industries (those industries
listed under SIC 20), the water pollution control, air pollution control
and solid waste management practices of 19 specific food processing in-
dustries were reviewed. The 19 industries analyzed represent in excess
of 75% of the total value of shipments by the food processing industries.
One specific objective of the assessment was to identify any potential
toxic substances emission problems. The method of approach used in con-
ducting the study was to prepare process descriptions on a unit operations
basis for each industry and to identify the sources of emissions and
effluents from each major step in the process. These process descriptions
along with a general industry description are contained in 18 unpublished
appendices available from the EPA Food and Wood Products Branch in Cin-
cinnati, Ohio. The published volume of the report and its eight published
appendices discuss the major sources of water pollution, air pollution,
and solid wastes from the food processing industries. The appendices
address specific topics such as SOV emissions, polynuclear aromatic
X
hydrocarbons, phenolic compounds, and water reuse (including pesticides).
This report was submitted in fulfillment of Grant No. R 804642-01-2
by SRI International under the sponsorship of the U.S. Environmental
Protection Agency. This report covers the period 1 June 1977 to 23 April
1978 and was completed as of 28 April 1978.
-------
CONTENTS
Foreword ill
Preface iv
Abstract . v
List of Illustrations ix
List of Tables x
1. Introduction 1
Classification of the Agricultural and Food Processing
Industries 2
Summary Profile of Priority Industries Considered ... 4
Common Unit Operations 8
2. Summary and Conclusions 9
3. Air Pollution Problems 11
Combustion of Fuels 11
Process Sources of Air Pollutants 14
Odor Emissions and Control 20
References 32
4. Solid Wastes and Residues 36
Relative Magnitude of the Problem 36
Solid Waste Distribution in the Food Industries .... 39
Ranking of the Solid Waste Problems 42
Canned and Preserved Fruits and Vegetables Industry . . 43
Meat Packing Industry 44
Dairy Industry 47
Miscellaneous Food Processing 48
References 51
5. Water Pollution Problems 52
Relative Magnitude of the Problem 52
Wastewater Distribution in the Food Processing
Industries 56
Ranking of Raw Wastewater Loads 58
Waterborne Toxic Pollutants 58
Water Reuse and Recycling 58
Canned, Frozen, and Preserved Fruits and Vegetables
Industry 60
Seafood Processing Industry 65
Sugar Processing Industry 69
Meat Industries 72
vii
-------
6. Pesticides 76
References 82
Appendices*
A. Sulfur Oxides Emmissions 83
B. Polynuclear Aromatic Hydrocarbons ... • • 90
C. Chlorinated Hydrocarbons 96
D. Pesticide Emission from Roasting Operations 100
E. Sources of Phenolic Compounds in Citrus Processing
Wastewaters 105
F. Pesticide Levels in Wastewaters from Sweet Potato
Processing Operations 108
G. R&D Work on Wastewater Reuse for a Cannery 110
H. R&D Work on Treatment and Reuse of Poultry Processing
Wastewater 116
1. Meat Packing Industry
2. Meat Processing Industry
3. Poultry Dressing Industry
4. Egg Breaking and Processing Industry
5. Canned and Preserved Seafood Industry
6. Industrial Fishery Products Industry
7. Industrial Rendering Industry
8. Overview of Fresh, Canned, Frozen, and Dehydrated Fruit and
Vegetable Industry
9. Canned, Frozen, and Dehydrated Fruit Processing Industry
10. Canned, Frozen, and Dehydrated Vegetable Processing Industry
11. Specialty Food Processing Industry
12. Cane Sugar Industry
13. Beet Sugar Industry
14. Dairy Industry
15. Wheat, Duram, Dry Corn, Oat, and Rye Milling Industry
16. Wet Corn Milling Industry
17. Rice Milling Industry
18. Edible Fats and Oils Industry
*Lettered appendicies are contained in this volume. Numbered appendices
are available from EPA Industrial Environmental Research Laboratory, Food
and Wood Products Branch, 5555 Ridge Avenue, Cincinnati, Ohio 45268
viii
-------
FIGURES
Number Page
1 Distribution of Waste for Disposal
Among 21 SIC Code Groups 37
A-l Flow Sheet and Material Balance for
Apple Sulfiting and Drying 87
A-2 Flow Sheet and Material Balance
for Apricot Sulfuring and Drying 89
D-l Flow Sheet and Material Balance
for Peanut Roasting 100
G-l Schematic Flow Diagram of Wastewater
Treatment System for Snokist Growers Ill
H-l Wastewater Treatment and Water
Reclaiming Facilities for Sterling
Processing Corporation 117
IX
-------
TABLES
Number
1 Contribution of Industries Under Study
to the Total Food Industry 5
2 Number of Establishments and Employees
and Shipment Value for Each Industry ^
3 Energy Use Patterns by Type of Energy
for the Major User Industries in 1973 13
4 Major Process Sources of Particulates
in the Food Processing Industries 1
5 Particulate Emission Factors 1?
6 Comparison of Particulate Emissions from
Grain Milling and Other Large Industrial
Sources of Particulates 18
7 Principal Sources of Nuisance Odors in the
Food Processing Industry 21
8 Comparison of Solid Waste Estimates
for Manufacturing Industries 38
9 Quantitative Estimates of Solid Waste
Production for California, 1969 39
10 Estimated Quantities of Solid Wastes from
Food Industry in the United States, 1965 40
11 Estimated Quantities of Solid Wastes from
Food Industry in California, 1967 40
12 Summary of Significant Proces-Related
Solid Wastes Problems 41
13 Examples of Good Utilization Technology
for By-Products or Solid Wastes from Food
Industries 42
14 Examples of Technology that May Gain in
Popularity in the Future 43
15 Disposal Methods for Canned, Frozen, and
Preserved Food Wastes in the United States, 1973 ... 43
16 Industry Solid Residuals by Product and Month ... 45
17 Industry Solid Residues by Product and
Disposal Method 46
18 Industrial Discharges by Industry Group 53
-------
TABLES (Continued)
Number Page
19 Estimated Volume, BOD , and Suspended Solids
for Industrial Wastewaters, Before Treatment, 1964 .... 54
20 Ranking of Industrial Water Pollution Problems
by Industry, 1964 55
21 Estimated Quantities of Wastewater Volume and Loads
from Food Industries in the United States, 1964 56
22 Estimated Quantities of Wastewater Volume and Raw Loads
from Major Food Industries in the United States, 1974 . . 57
23 Summary of Significant Wastewater Problems 59
24 Sources and Estimated Volumes of Wastewaters
from Processing Steps in Canning of Fruits 60
25 Ranking of Major Commodities by Significance
of Raw Waste Food 61
26 Importance Parameters and Weighting Factors
for Ranking Commodities 62
27 Comparison of EPA and NCWQ Contractor1s
Raw Waste Values 63
28 Results of Importance Matrix Analysis 64
29 Percentage of Production by Method of Wastewater
Management for Various Plant Categories, 66
30 Unit Waste Loads for Subcategories of Canned
and Preserved Seafood Industry 67
31 Estimated Quantities of Raw Materials Processed
in Canned and Preserved Seafood Industry in 1968 68
32 Estimated Wastewater Loads from Seafood
Processing Industry 68
33 Annual Wastewater Discharge of Sugar
Processing Industry ..... 69
34 Representative Character and Volume of Raw Cane
Sugar Manufacturing Wastes 70
35 Representative Character and Volume of
Beet Sugar Manufacturing Wastes 71
36 Red Meats and Poultry Processing Waste Loads 73
37 Estimated Wastewater Load and Volume
for Meat Industry in 1967 73
38 Maximum Allowable Concentration of Selected
Insecticides in Raw Citrus and Apple • ' 77
XI
-------
TABLES (Continued)
Number Page
39 Quantity of Wastewater and Solid Wastes
from Selected Food Industries ....
40 Maximum Potential Concentration for Selected
Insecticides in Wastewaters from Food Industries 79
41 Half-Lives for Selected Organophosphorous
Insecticides 80
42 Maximum Potential Concentration for Selected
Insecticides in Solid Wastes from Food Industries .... 80
A-l Estimated Hourly Emissions of S02 from Sulfuring
of Apples and Apricots 86
A-2 Comparison of SO Sources 89
B-l Hazardous Pollutant Sources 94
D-l Type and Tolerance Level of Pesticides
Applied to Peanuts 101
D-2 Comparison of Pesticide Emission from Peanut
Roasting with Occupational Standard 103
E-l Levels of Phenolic-Type Compounds in Samples
Taken at Various Points in Citrus Packinghouses
in the Ridge and Indian River Districts 105
E-2 Levels of Free and Conjugated Phenolics as
Determined by the 4-Aminoantipyrine Method
in Four Common Beverages 106
F-l DDT Concentration in Treated and Untreated
Sweet Potato Wash Water 109
G-l Pesticide Concentrations in Reused and Tap
Water at Snokist Growers' Fruit Processing Plant 113
G-2 Volatile Halogenated Organics—Snokist Growers'
Wastewater Reuse Project 114
G-3 Trace Metal Analyses for Reused and Tap Water
at Snokist Grower's Fruit Processing Plant 115
H-l Effectiveness of Wastewater Lagoon System ... 118
H-2 Effectiveness of Advanced Treatment System 119
H-3 Chemical-Physical Quality of Reclaimed Water 120
xii
-------
SECTION 1
INTRODUCTION
In conducting this preliminary multimedia environmental assessment
of the food processing industries, SRI International first conducted an
exhaustive literature review. The primary goal of this review was to
determine what toxic pollutants (as identified in the Settlement Agreement
in the United States District Court for the District of Columbia, dated
June 7, 1976) may be emitted from food processing plants and the medium
and quantities in which they are emitted. This literature review pro-
duced very little information on toxic pollutant sources and no quanti-
tative data on the magnitude of known releases of pesticides. This re-
sult was not entirely unexpected by SRI or EPA staff members.
In the main body of the report, we have presented data on industry
size, compared environmental problems of the food processing industries
relative to other nonfood industries as well as to each other, and iden-
tified and quantified, where possible, known or potential problems that
have not received attention to date under EPA research and development
programs. Those industries that were assigned high and moderate priorities
in terms of water pollution, air pollution, solid waste problems, and
known or potential toxic waste sources are described in detail in the
body of the report and Appendices A through H. In Appendices 1 through 18
each industry is discussed by sector on a commodity or product basis, and
individual unit operations in each industry are described.
Each section of the main body of this report deals with a specific
type of pollution problem. For water pollution, for example, the magni-
tude of water pollution problems in the food industries is first compared
to that of other nonfood industries. Then water pollution problems are
ranked within the food industries. The food industries with major water
pollution problems are discussed in detail in the main body of the report,
and the wastewater characteristics from major commodities and unit ^
operations are further reviewed in the numbered appendices (1 through 18).
Available upon request from Environmental Protection Agency, Industrial
Environmental Research Laboratory, Food and Wood Products Branch,
5555 Ridge Ave., Cincinnati, Ohio 45268.
-------
CLASSIFICATION OF THE AGRICULTURAL AND FOOD PROCESSING INDUSTRIES
The Department of Commerce has classified the agricultural production
and food processing industries into four Standard Industrial Codes (SIC),
as listed below.
e SIC Major Group 01: Agricultural Crop Production Industry
This industry includes establishments (e.g., farms, orchards,
greenhouses, nurseries) primarily engaged in the production
of crops or plants, vines and trees (excluding forestry
operations). It also includes sod farms, mushroom cellars,
cranberry bogs, and the production of bulbs, flower seeds,
and vegetable seeds. The major crops included in this
industry are:
- Cotton
- Fruit and Tree Nuts
- Grains
- Soybeans
- Specialty Crops
- Sugar Crops
- Tobacco
- Vegetables and Melons.
e SIC Major Group 02: Agricultural Livestock Production Industry
This industry includes establishments (e.g., farms, ranches
feedlots) engaged in keeping, grazing, or feeding livestock
for the sale of livestock or livestock products (including
serums) or for livestock increase. Livestock includes
cattle, hogs, sheep, goats, poultry of all kinds, and ani-
mal specialties such as horses, rabbits, bees, fish, or
fur-bearing animals bred in captivity.
e SIC Major Group 07: Agricultural Services Industry
This industry includes establishments primarily engaged in
performing soil preparation services, crop services,
veterinary services, other animal services (such as breed-
ing, boarding, grooming), farm labor and management services,
and landscape and horticultural services for others on a
fee or contract basis.
-------
• SIC Major Group 20: Food and Kindred Products Industry
This major group includes establishments manufacturing or
processing foods and.beverages for human consumption,
and certain related products, such as manufactured ice,
chewing gum, vegetable and animal fats and oils, and pre-
pared feeds for animals and fowl.
The major groups of products in this industry are:
- Bakery Products
- Beverages
- Canned and Preserved Fruits and Vegetables
- Dairy Products
- Fats and Oils
- Grain Mill Products
- Meat Products
- Sugar and Confectionery Products
- Miscellaneous Food Preparations.
This report includes only industries listed under SIC 20. Within
SIC 20, the industries may be subdivided into two major groupings as
shown below:
0 Intermediate Processing
Vegetable oil processing industry
Industrial rendering industry
Sugar industry (cane and beet)
Flour milling industry
Rice milling industry
Malt processing industry
Wet corn milling industry
Meat packing industry
o Final Goods Processing
Animal feed industry
Meat processing industry
Poultry processing industry
Seafood industry
Dairy products industry
Beverage industry (malted beverage, wine, liquor, soft drinks)
Canned and preserved fruits and vegetables industry
-------
Baking industry
Cereal breakfast food industry
Food preparation products industry
Macaroni and spaghetti industry
Roasted coffee industry
Confections industry
Chocolate and cocoa industry.
The industries classified as intermediate processors primarily
process farm products into items that may require further processing
before final use. There are exceptions, such as refined sugar products
and flour. Direct sales from this stage of the process to the consumer,
however, are quite small in terms of total production within this
classification.
The final goods classification includes firms that produce products
that are primarily ready for human consumption.
SUMMARY PROFILE OF PRIORITY INDUSTRIES CONSIDERED
Industries that fall within the scope of the EPA study for "Pre-
liminary Multi-Media Assessment of Pollution Problems in the Food In-
dustries form a major part of the food system in the United States.
As measured by the Census of Manufacturers, these industries represent
approximately 95.2% of total establishments, 98.1% of total employees,
and 98.4% of total shipment value. The industries constituting the
priority list for the assessment include:
• Meat Packing
» Meat Processing
e Poultry Dressing
• Egg Breaking
• Vegetable Oil Processing and Edible Fats and Oils
• Industrial Rendering
* Grain Milling (including Flour, Rice, Wet Corn)
e Livestock Food
• Seafoods
® Canned and Preserved Fruits and Vegetables
-------
* Malted Beverages
• Roasted Coffee
• Sugar (Cane and Beet)
• Dairy.
These industries represent approximately 58.2% of total establishments,
63.7% of total employees, and 76.9% of total shipment value. Table 1
shows the contribution of the industries under study to the total food
industry. The industries on the priority list were chosen because they
are known to represent a very high percentage of the air pollution,
water pollution, and solid waste problems.
TABLE 1. CONTRIBUTION OF INDUSTRIES
UNDER STUDY TO THE TOTAL FOOD INDUSTRY
No. of
establishments
Average Total Number
of employees per year
(thousands)
Shipment
value
($ millions)
Industries
within
scope of
study 27,100
Priority
industries
within scope
of study 16,689
Total, all SIC 20
industries 28,192
1,539.1
999.7
1,569.9
$ 113,180.5
88,437.6
114,983.5
Source: Census of Manufacturers, 1972.
Detailed information on the number of establishments, average
total number of employees per year, and shipment value for each industry
is given in Table 2.
The dairy industry possesses the largest number of total estabish-
ments in the industry (4,590, 16.3% of the total). The baking industry
has the greatest average number of employees (235.5 thousand, 15% of
the total), and the meat packing industry has the greatest shipment
value ($23,024.0 million, 20.0% of the total).
-------
TABLE 2. NUMBER OF ESTABLISHMENTS AND EMPLOYEES AND SHIPMENT VALUE FOR EACH INDUSTRY
Priority industries in the study
1. Meat packing
2. Meat processing
3. Poultry dressing
4. Poultry and egg processing
5. (Canned and cured seafoods
(Fresh and frozen packaged fish
Canned fruits, vegetables,
preserved jams and jellies
Dried /dehydrated fruits, vege-
tables, and soup mixes
6. , Frozen fruits, fruit juices,
and vegetables
Frozen specialities
Canned specialties
Pickled fruits/vegetables
7. /Cottonseed oil mills
1 Soybean oil mills
I Other oil mills
'shortening and cooking oils
8. (Prepared feeds, nee
(Dog, cat, other pet foods
9 •&( Animal and marine fats and
10. 1 oils
11. Malted beverages
12. Roasted coffee
13. Cane sugar refining
14. Beet sugar
15. Flour and other grain mill
products
16. Rice milling
17. Wet corn milling
SIC
No.
2011
2013
2016
2017
2091
2092
2033
2034
2037
2038
2032
2035
2074
2075
2076
2079
2048
2047
2077
2082
2095
2062
2063
2041
2044
2046
Establishments
Number % of Total
2,475 8.8
1,311 4.7
5221 2.3
130 /
308] 2.9
518
..
1,038
178
209 9.1
435
203
495
115
941 1.2
31
109
2,120 8.3
221
511 1.8
167 0.6
213 0.8
33 0.1
61 0.2
457 1.6
57 0.2
41 0.1
Avg. total no. of
Employees per year
Number
(OOOs) % of Total
157.6 10.1
58.1 3.7
77.6 5.9
14.6
14.8 2.5
24.7
89.8
12.4
42.9 14.9
38.3
29.1
20.8.
5.5\
9.ll 1.8
1.1
12.9/
44.0 3.7
14.3
11.5 0.7
51.5 3.3
12.9 0.9
10.9 0.7
11.5 0.7
16.1 1.0
4.0 0.3
12.1 0.8
Shipment value
$ Millions % of Total
23,024.0 20.0
4,632.4 4.0
3,254.1 3.3
588.1
719.3 1.5
1,061.6
-.
4,043.8
607.3
1,852.4 10.0
1,935.5
1,876.6
1,166.7
458. 7 \
3,357.21 5.3
252.21
2,068.l'
5,037.1 5.6
1,401.9
764.6 0.7
4,054.4 3.5
2,328.7 2.1
1,742.7 1.5
880.2 0.8
2,380.0 2.1
680.6 0.6
832.3 0.7
(continued)
-------
TABLE 2 (CONTINUED)
Establishments
No.
Number
% of Total
Avg. total no. of
Employees oer year
Number
(OOOs)
% of Total
Priority industries in the study
18.
19.
Other
20.
21.
22.
23.
24.
25.
26.
27.
28.
Cereal breakfast foods
Creamery butter
Cheese--natural and proc-
essed
Condensed and Evaporated
milk
Ice cream and frozen desserts
* Fluid milk
Subtotal
industries in the study
Flavoring extracts
Distilled liquor
Chocolate and cocoa
Wines
(Bread, cake, etc.
(Cookies, crackers
Macaroni and spaghetti
Confectionary
Food preparations
Soft drinks
Subtotal
>043
2021
2022
2023
2024
2026
2087
2085
2066
2084
2051
2052
2098
2065
2099
2086
47
231\
872
283
697
2.507'
16,689
400
121
48
213
3,323
315
194
1,011
2,099
2.687
10,411
0.1
16.3
58.2
1.4
0.4
0.2
0.8
12.9
0.7
3.6
7.5
9.5
37.0
12.9
4.0'
25.2
12.3
21.1
126.1'
999.7
10.1
18.4
10.0
9.4
194.4 |
41. ij
7.3
60.7
66.2
121.8
539.4
0.9
11.8
63.7
0.6
1.2
0.6
0.6
15.0
0.5
3.9
4.2
7.8
34.4
Shipment value
$ Millions
1,125.5
808.3 '
3,195.0
1,667.8
1,244.7
9.395.8 '
88,437.6
1,472.0
1,797.9
735.5
865.0
6, 152. 6 |
1,763.5)
349.6
2,472.5
3,647.9
5,486.4
24,742.9
% of Total
1.0
14.2
76.9
1.3
1,6
0.6
0.7
6.9
0.3
2.1
3.2
4.8
21.5
Industries not discussed in detail
Blended and prepared flour
Malt
Raw cane sugar
Chewing gum
Manufactured ice
Subtotal
Total
2045
2083
2061
2067
2097
137
40
78
19
818
1.092
28,192
0.5
0.1
0.3
0.1
2.9
3.9
100.0
7.9
1.7
7.5
6.9
6.8
30.8
1,569.9
0.5
0.1
0.5
0.4
0.4
1.9
100.0
704.6
226.3
427.1
328.6
116.4
1,803.0
114,983.5
0.6
0.2
0.4
0.3
0.1
1.6
100.0
nee = not elsewhere classified.
Source: SRI International.
-------
COMMON UNIT OPERATIONS
The food processing industries are extraordinarily diverse and
include the following common unit operations:
• Material handling. Conveying, elevating,pumping,
packing, and shipping.
• Separating. Centrifuging, draining, evacuating,
filtering, percolating, fitting, pressing, skimming,
sorting, and trimming. (Drying, screening, sifting,
and washing fall into this category.)
• Heat exchanging. Chilling, freezing, and refrig-
erating; heating, cooking, broiling, roasting,
baking, smoking, and so forth.
® Mixing. Agitating, beating, blending, diffusing, dis-
persing, emulsifying, homogenizing, kneading, stirring,
whipping, working, and so forth.
» Peeling and Size Reduction. Peeling, breaking, chip-
ping, chopping, crushing, cutting, grinding, milling,
maturating, pulverizing, refining (as by punching,
rolling, and so forth), shredding, slicing, and spray-
ing.
® Forming. Casting, extruding, flaking, molding, pel-
letizing, rolling, shaping, stamping, and die casting.
® Coating. Dipping, enrobing, glazing, icing, panning,
and so forth.
• Decorating. Embossing, imprinting, sugaring, topping,
and so forth.
• Controlling. Controlling air humidity, temperature,
pressure, and velocity; inspecting, measuring, tem-
pering, weighing, and so forth.
e Packaging. Capping, closing, filling, labeling,
packing, wrapping, and so forth.
• Storing. Piling, stacking, warehousing, and so forth.
-------
SECTION 2
SUMMARY AND CONCLUSIONS
In conducting the assessment of the pollution sources and control
measures utilized by the food processing industries (those industries
listed under SIC 20), the water pollution control, air pollution con-
trol and solid waste management practices of 19 specific food processing
industries were reviewed in detail. These 19 industries represent in
excess of 75% of the total value of shipments by the food processing
industries. One specific objective of the assessment was to identify
any potential toxic substances emission problems. The method of approach
used in conducting the study was to prepare process descriptions on a
unit operations basis for each industry and to identify the sources of
emissions from each major step in the process. These process descriptions
along with a general industry description are contained in 19 unpublished
appendices available from the EPA Food and Wood Products Branch in Cin-
cinnati, Ohio. This published report volume with appendices contains
the reviews of the major sources of water pollution, air pollution, and
solid wastes from the food processing industries. The appendices address
specific topics such as SOX emissions, polynuclear aromatic hydrocarbons(PAH),
phenolic compounds, and water reuse (including pesticides).
From this analysis it has been shown that the food processing
industries:
• Are not in total a major source of emissions of SOX, NOX,
particulates, hydrocarbons, or PAH, relative to other
major industries. However, individual food processing
plants sometimes present fairly severe local problems
from emissions of particulates, and are fairly frequent
major sources of odors.
-------
• Generally have technology available (although perhaps
not applied) to control the emissions of air pollutants.
However, process modifications or developments could
often be applied to reduce the costs of air pollution
control.
• Are major sources of industrial solid wastes or residues,
* In numerous cases are utilizing the solid wastes or
residues as a supplementary fuel, as an animal feed, or
returning the materials to agricultural land.
• Are major industrial sources of water pollutants as
indicated by the conventional parameters of BOD5 and
suspended solids.
• Are minor industrial sources of toxic substances (as
specified in the June 1976 settlement agreement in the
United States District Court for the District of
Columbia) but are faced with problems associated with
pesticide residues.
• Have generally been able to treat their wastewaters
using biological treatment processes on-site (lagoons,
trickling filters or activated sludge systems) in
municipal treatment systems, or on land.
• Have unique problems in attempting to implement water
reuse and recycle systems because of the nature of the
raw materials (often contain pesticide residues on the
product surfaces) and the high water quality required
to satisfy health standards.
• Are investigating the potential problems associated
with pesticide residues (often in cooperation with the
EPA or other government agencies). However, not a
great deal has been published to date on the specific
problems associated with recycle or reuse of solid
wastes or water containing pesticide residues.
10
-------
SECTION 3
AIR POLLUTION PROBLEMS
The gross emissions of particulate matter (e.g., S02, NQx and total
hydrocarbons) by the food processing industries are relatively minor when
compared with those of other large energy-intensive industries that process
materials mechanically or thermally. Nevertheless, air pollution from food
processing operations can present substantial—and occasionally acute--
local problems. Many of these problems, such as odors, are in the cate-
gory of nuisances, but a few, such as allergenic effects of grain dust,
may present direct hazards to health.
Probably the most pervasive air pollution problem associated with
the food industries is the emission of odors. Although certain parts of
the food industry are notorious as sources of nuisance odors, most of
the industry may emit odors of one kind or another under some circum-
stances. 2-1,-2 Even food odors that are regarded as pleasant when asso-
ciated with preparation of a meal may become objectionable when emitted
continuously and in large volume. For example, the odor of freshly
brewed coffee is regarded by most persons as pleasing, but the same
odorous materials may be obnoxious or even nauseating when emitted in
o_ o
large quantities by a commercial coffee roaster. Several processes
in the food industry produce odors that are particularly obnoxious even
in small quantities. Some of these processes, such as inedibles rendering,
are widespread in location and well known. Others are well known as
odor problems only in a few localities. Onion and garlic drying produces
odors that are detectable as much as 30 miles from the source, however,
the processing plants are few in number and are currently located only in
a few places in California.
COMBUSTION OF FUELS
The food industries rank last among the top six energy-consuming
industries listed below.2"^ They also have the lowest energy consump-
tion per dollar of product value added in processing.
11
-------
Kcal/$ of
Total Fuel Use Value Added
(1012 kcal) in Processing
Primary Metals 1310 40,000
Chemical Industry 1160 35,000
Petroleum Industry 766 140,000
Paper Industry 645 50,000
Stone-Clay-Glass-Concrete 365 40,000
Food Industries 323 10,000
Data on the 1973 energy use patterns by energy source are given in
Table 3 for the major energy-consuming food processing industries.2-5
For the industry group as a whole, less than 10% of the total energy
consumed was obtained from burning coal, and less than 7% was obtained
from residual oil. Natural gas supplied 48% of the total energy, and
purchased electricity supplied 28%. The "clean" sources of energy,
natural gas and electricity, are much favored in the food industry when
they are available. Only wet cornmilling, beet sugar processing, and
soybean oil mills derived substantial fractions (15% or more) of their
total energy requirements from coal, and that use pattern may have re-
flected the geographical location of the particular plants using the coal.
As indicated in Table 3 and the tabulation below, by far the greatest
portion of the fuel consumed is used to raise steam for process heating,
with much smaller amounts being used to generate electric power and for
firing of processes.
Purchased or self-generated electric power 30%
Steam for process heating 65%
Direct firing for process use 5%
100%
The problems of emissions from industrial boilers and their control
are no different in the food industries than in other industries, and
therefore, they need not be addressed in this analysis. To the extent
that residual oil and coal may be substituted for natural gas, boiler
furnace emissions may be substantially increased in the future.
12
-------
TABLE 3. ENERGY USE PATTERNS BY TYPE OF ENERGY FOR THE MAJOR USER INDUSTRIES IN 1973
(Percent)
SIC
No.
2011
2013
2026
2033
2037
2042
2046
2062
2063
2082
2094
2097
2051
2092
Middle
Industry Propane
Meat packing
Sausage and processed meat
Fluid milk
Canned fruits and vegetables
Frozen fruits and vegetables
Prepared animal feeds
Wet corn milling
Cane sugar refining
Beet sugar processing
Malt beverage
Animal and marine fats and oils
Manufactured ice
Bread and related products
Soybean oil mills
Total (weighted averages)
2.5
1.5
1.8
2.9
1.0
3.2
0.1
Z
z
0.7
0.8
0.0
0.7
Z
1.3
distillates
4
8
8
2
1
3
5
0
0
5
6
3
16
4
5
.7
.8
.6
.4
.3
.5
.3
.6
.1
.3
.5
.5
.2
.0
.1
Residual
fuel oils
6.6
4.3
4.6
9.3
3.0
2.5
2.0
32.3
5.0
11.5
9.3
0.0
2.1
5.0
6.6
Other
petroleum
Natural
products Coal %as
0.2
0.2
2.1
Z
Z
1.0
z
z
z
z
0.7
Z
18,8
Z
1.9
8.6
0.7
2.9
3.4
3.7
0.4
35.5
0.0
24.9
7.0
0.6
0.0
Z
16.3
9.4
46.1
46.7
33.2
65.9
40.8
51.6
43.0
66.4
64.8
38.3
65.2
11.5
34.1
46.8
47.5
Other
fuels*
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
4.0
0.0
0.0
0.0
0.0
0.0
0.4
Purchased
electricity Total
31.4
38.2
46.6
16.5
50.2
38.0
14.1
0.6
1.3
37.2
16.6
85.0
28.3
27.8
27.9
100.0
100.0
100.0
100.0
100.0
100.0
100.0
100.0
100.0
100.0
100.0
100.0
100.0
100.0
100.0
Note: Totals may not add to 100 due to rounding.
*
Lubricants and Gasoline.
Coke.
Source: Reference 2-5 .
-------
In some food processing industries, associated wasted products may
be usable as boiler fuel. The most notable instance is the use of
bagasse as fuel in the cane sugar industry. The potential ash and cinder
emissions from bagasse-fired boilers are high enough to require appropriate
dust collection equipment.
Direct firing of process vessels is practiced primarily for the
roasting or drying of various commodities. In such cases, the combustion
products come into direct contact with the materials being processed,
and the effluent gases may carry contaminants derived from both the fuel
burned and the process material. Where the material being processed is
intended for human consumption, at least, a "clean" fuel must be used
in direct firing, and the fuel most often used is natural gas. In such
cases, the contaminants in the gas stream are derived almost entirely
from the process material. In any process involving direct firing, the
gaseous and particulate effluents are specific to the process and material
involved.
PROCESS SOURCE OF AIR POLLUTANTS
The "noncombustion" air pollution problems that may arise from
processing in the food industry are associated with the following types
of processes:
Process
Pollution
Problem
Mechanical Handling
(size reduction,
conveying)
Thermal Processing
(roasting, blanching,
concentrating, drying,
frying and other
cooking operations)
Preserving and Flavoring
(sulfuring, smoking)
Extracting and Refining
Peeling
Particulates
Odors from volatiles
Particulates
Odors
Particulates
sox
Odors
PAH (toxic)
Hydrocarbons
Odors
Chlorinated organics
Chlorinated organics
14
-------
Some major process sources of parttculate emissions in the food
processing industries are summarized in Table 4. Particulate emission
factors for these sources are presented, where available, in Table 5.
For comparison, the emissions from grain milling operations are shown
in Table 6 along with the emissions from Portland cement manufacturing
plants and coal-fired power plants.
Particulate control problems in the food industry result mainly
from solids handling, solids size reduction, drying, roasting and cooking.
Some of the particulates are dusts, but others (particularly those from
thermal processing operations) are produced by condensation of vapors
and may be in the low-micrometer or submicrometer particle-size range.
Particulate collection for numerous sources, such as fish meal driers,
deep fat frying, smokehouses, and coffee roasters have been discussed
f\ £
by Danielson. With proper equipment selection and installation, all
the problems can be adequately handled. Problems with particulate con-
trol in the grain milling industry, malting and liquor industry, and
the citrus industry are also amenable to solution using currently avail-
able particulate collection devices.
The grain milling industry is one of the largest, if not the largest,
source of actual or potential dust emissions in the food processing
industries. This is particularly true if the category is taken to in-
clude the premanufacturing phases of grain handling: grain cleaning
and drying, storage and handling at elevators, and custom grinding of
feed. These phases are technically not part of the food processing in-
dustry as defined in this report (SIC 20, Food and Kindred Products),
but fall into the major groups SIC 07, Agricultural Services: SIC 42,
Motor Freight Transportation and Warehousing; and SIC 51, Wholesale
Trade—Nondurable Goods.
The problem of SC>2 emissions from the sulfuring of fruit is dis-
cussed in Appendix A. Our conclusion is that the sulfuring of fruit
is not a significant source of S02 emissions, relative to other point
sources. However, the release of the S02 at or near ground level may
produce problems near installations.
The potential toxic problems identified fall into four classifica-
tions:
(1) Polynuclear aromatic hydrocarbons (PAH) from smokehouses.
(2) Chlorinated organics from extraction and peeling operations.
15
-------
TABLE 4. MAJOR PROCESS SOURCES OF PARTICULATES IN THE FOOD PROCESSING INDUSTRIES
Industry
Meat processing
Vegetable oil processing
Grain milling
(dry processes)
Grain milling (wet
corn processing)
Livestock food
Livestock fishmeal ind.
Malted beverage
Distilled liquor
Roasted coffee
Sugar cane
Canned and preserved
fruits and vegetables
Size
Transport reduction
X
X
X
Cleaning
and
classifying Roasting Drying Cooking
X
X
X
X
X
X
X
X
X
X
Examples
Smoke houses
Flour mills
Alfalfa dehydrating and
grinding (baghouses)
Fish meal dryers
Grain handling, spent
grains drying
Grain handling, spent
grains drying
Coffee roasting, stoner
and cooler, instant
coffee spray dryer
Bagasse-fired boilers
Citrus peel dryers
Source: SRI International.
-------
TABLE 5. PARTICULATE EMISSION FACTORS
Industry
Meat processing
(smokehouses)
Vegetable oil processing
(soy beans)
Grain milling
Rice
Wheat flour
Wet corn
Livestock food (meal)
(alfalfa dehydration)
Livestock fishmeal
Malted beverage
(spent grains)
Distilled liquor
(spent grains)
Roasted coffee
Sugar cane
(bagasse)
Emission factor
0.3 Ib/ton Uncontrolled (D)
0.1 Ib/ton Controlled (D)
7 Ib/ton (B)
0-69 ~ 5.7 Ib/ton
3.4 ~ 4.2 Ib/ton1"
2.2 Ib/tont
60 Ib/ton Uncontrolled (E)
3 Ib/ton Controlled (E)
0.1 Ib/ton Driers (C)
8 Ib/ton Handling and drying (E)
8 Ib/ton Handling and drying (E)
7.6 Ib/ton Direct-fired (B)
4.2 Ib/ton Indirect-fired (B)
22 Ib/ton bagasse fiber (D)
The accuracy of the emission factors is ranked as "A," "B", "C",
"D", or "E". "A" is considered excellent, "B" above average,
"C" average, "D" below average, and "E" poor.
SRI-estimated values.
Sources: EPA Compilation of Emission Factors, Second Edition,
AP-42; SRI International.
Note: To convert pounds to kilograms, divide by 2.2.
17
-------
TABLE 6. COMPARISON OF PARTICULATE EMISSIONS FROM'GRAIN MILLING
AND OTHER LARGE INDUSTRIAL SOURCES OF PARTICULATES
Particulate
emission rate
Type of plant
Rice milling
Wheat flour milling
Wet corn milling
*
Power plant
(coal-fired)
Portland cement
Emission factor
*
0.69 ~ 5.7 Ib/ton
it
3.4 ~ 4.2 Ib/ton
*
2.2 Ib/ton
0.1 lb/106 Btu
0.3 Ib/ton of feed
Typical plant size
600 cwt/hr
200 cwt/hr
1400 cwt/hr
500 MW
70 tons of feed/hr
(Ib/hr)
21 ~ 171
34 ~ 42
154
315
21
SRI-estimated values.
t
Federal New Sources Performance Standards.
*
Assume power plant capacity factor of 0.7.
Source: EPA; SRI International.
(3) Pesticides and other possible toxic compounds emitted from
roasting or drying operations.
(4) Allergenic materials in grain dust.
Problems 1, 2, and 3 above are discussed in Appendices B, C, and D,
respectively.
Estimates of the maximum potential emission of PAH from smokehouses,
presented in Appendix B, show that the gross emissions from these in-
dustrial sources are extremely small relative to other point sources.
Although smokehouses could be the source of airborne particulates and
sludges contaminated with PAH, it would be difficult to quantify the
actual impact of such discharges. Localized effects from such discharges
could be more important.
18
-------
In Appendix C, all major known and proposed uses for chlorinated
solvents in the food industry have been identified. Less than 3% of the
total industrial consumption in 1974 of trichloroethylene (TCE) was for
food processing and this percentage likely has dropped as methylene
chloride has been introduced as a substitute. The food industry is a
very minor source of the other previously mentioned toxic pollutants,
but their localized effects might be important. Such compounds may be
released from plants in both the gas phase and the liquid phase. Air
stripping in biological treatment systems is likely to remove the com-
pounds from water rapidly. ~'»~°
Estimating the quantities of pesticides emitted from food processing
operations requires determining which pesticides are actually used and
in what quantity they are present on the commodity as it reaches the
processing plant. Little detailed information on either subject appears
to be available. Some rough estimates of possible pesticides emissions
from peanut roasting (Appendix D) were made in an effort to assess
whether such emissions might actually be significant. The indicated
pesticide concentrations in the roaster waste gas exceed slightly or
moderately the allowable occupational standards for worker exposure, but
the resulting concentrations in ambient air after dispersion and dilution
of the stack gas would be much lower. It is questionable whether the
indicated emissions would be significant even if they proved to be real.
Dusts from grain handling and milling are generally in the nuisance
category, but they are also known to produce allergic reactions in sen-
sitive individuals. Emissions of such dusts to the atmosphere may affect
sensitive individuals in the general population as well as workers in the
grain mills. In a study at the University of Minnesota, Cowan et al
concluded that there was a possible association between air pollutants
from the grain industry nearby and the incidence of acute allergenic
asthma among university students. Weill et al demonstrated an asso-
ciation between local episodic asthma in New Orleans and allergenic air
pollutants emitted from grain elevators in the area.
Although rice hulls contain a significant amount of silica and the
soil picked up with the grain during harvesting may contain some free
silica, the chance that dust from these sources might present a silica
inhalation hazard is so remote as to be negligible. To be dangerous,
the material must be crystalline-free silica (not silicates or other such
compounds) and must be in the respirable particle-size range (i.e.,
£ about 2 jam). The actual quantities of material of this description are
likely to be very small. The free silica in rice hulls is amorphous
(noncrystalline), and hence not dangerous.
19
-------
In cotton growing the plants are commonly sprayed with a defoliant
before harvesting. Defoliation of the cotton plants makes machine picking
of the cotton easier. The defoliants used have generally been organic
arsenic compounds. Consequently, the trash (e.g., leaves, stems) collected
along with the seed cotton is contaminated with arsenic residues. The
outer tips of the cotton fibers will also carry some residual arsenic,
but the seeds should be generally well protected from contact with the
defoliant. At the cotton gin, the trash is separated from the cotton
and is normally burned. During combustion of the trash, at least part
of the arsenic enters the offgases and is emitted to the atmosphere.2-11
If the arsenic-bearing material did reach the cotton seed, it would
present primarily a potential hazard in a food product. Apparently,
the existence of any actual hazard has not been reported. The emissions
from trash burning are not within the category of food processing indus-
tries. Cotton ginning (SIC 0724) falls under Agricultural Services.
ODOR EMISSION AND CONTROL
Odor emissions may occur at almost any stage of food processing, but
the most serious ones usually are associated with the thermal processing
steps such as cooking, .roasting, drying, and evaporative concentration.
The waste gases from these operations will usually contain particulate
matter and perhaps condensable vapors as well as the malodorous substances.
Such particulates and condensable materials complicate the problem of
collecting or destroying the malodors. The condensable materials them-
selves may be malodorous to some degree.
For some particularly malodorous operations (e.g., slaughtering, ren-
dering), the exhaust air from building ventilation may be so contaminated
as to be a major source of odor. 2-6 Wastewater treatment ponds are another
frequent source of odors, even from processing of materials that are not
otherwise particularly objectionable.2 -12,-13 Anaerobic digestion of
wastes is a frequent source of hydrogen sulfide emissions,2 -14,-15 although
such problems can frequently be alleviated or eliminated by proper design
of the treatment system. Aerobic treatment of wastewater may also produce
odors. ' Some hydrogen sulfide can be formed and emitted, particu-
larly under conditions of system overload.2-17 jn addition, various or-
ganic compounds (some of them malodorous) can be stripped out of solution
by the air stream used in aeration.2 "'>"°>"17
Table 7 lists food industries and processes that are major sources
of nuisance odors. These are sources that are well known or cited with
some frequency in the literature. The list is not exhaustive; as noted
previously, most of the food industries can be sources of odors under
20
-------
SIC
No.
2011
2013
2016
2017
2034
2037
2046
2047
2048
2051
2063
2066
2077
2082
2085
2087
2091
2092
2095
2099
Short Title
Meat packing plants
Prepared meats
Poultry dressing
plants
Poultry processing
Dehydrated fruits ,
vegetables
Frozen fruits
and vegetables
Wet corn milling
Dog, cat, and other
pet food
Prepared feeds , nee
Bread, cake and
related products
Beet sugar
Chocolate and
cocoa products
Animal and marine
fats and oils
Malt beverages
Distilled liquor
Flavoring extracts
and syrups , nee
Canned and
cured seafoods
Fresh and frozen
packaged fish
Roasted coffee
Food preparations ,
nee
Products
Fresh and processed meat;
lard; edible tallow and
stearin; blood meal
Processed meats; lard;
edible tallow and stearin
Dressed and packed poultry
and rabbits
Processed poultry products
Dried onions and garlic
Dried citrus pulp
Gluten meal; gluten
feed; germ meal
Horse meat and other
products
Feather meal; bone meal
Doughnuts
Dried beet pulp
Cacao beans
Animal oils; fish oil;
animal meal; fish meal;
inedible animal stearin;
fish solubles
Brewers ' grain
Distillers dried grain
and solubles
Flavoring extracts, pastes,
powders, and syrups
Fish: cured, dried,
pickled, salted, and
smoked
Fish: fresh, frozen;
prepared and frozen
Roasted coffee
Potato chips; corn chips;
French-fried potatoes
Operations
Slaughtering; edible-fats rendering
blood drying; waste treatment; meat
smoking; building ventilation
Edible-fats rendering; meat
smoking; building ventilation
Slaughtering; waste treatment;
building ventilation
Cooking; smoking; building ventila-
tion; waste treatment
Drying; building ventilation
Pulp drying
Fiber drying; gluten drying;
germ drying
Slaughtering of nonfood animals;
building ventilation
Digestion; drying
Deep fat frying
Drying; waste treatment
Roasting
Digestion; cooking; rendering;
evaporation; drying; air-blowing
grease or tallow; building ventila-
tion
Drying
Evaporation; drying
Evaporation; drying
Cooking; drying; smoking; building
ventilation
Cooking; building ventilation
Roas ting
Deep fat frying
Source: SRI International.
21
-------
some conditions. However, many such odor sources can be controlled
with modest efforts. The sources in Table 7 are generally those from
which the odor emissions are particularly large and/or obnoxious, and
for which control entails substantial efforts and engineering skills.
Malodorous Materials
Malodors in the food industry are seldom due to single chemical
agents. More commonly, they result from mixtures of chemical compounds
that have been only generally identified. Most of the known components
are sulfur or nitrogen compounds resulting from decomposition of plant or
animal matter. The indefinite nature of the materials makes it difficult
to devise odor controls based on highly specific chemical reactions or
physical properties such as solubilities.
The malodors result from substances in the gaseous or vapor forms.
However, some of the malodorous materials are substances of relatively
low volatilities, and may be present in a gas or air stream primarily
in the particulate form, that is, as solid particles or liquid droplets.
As the gas or air stream carrying the particulate material is diluted by
mixture with air (as, for example, following discharge of the gas stream
to the atmosphere), the particulate material gradually vaporizes and thus
tends to maintain the concentration of malodorous vapor. I" Such
particulates, or aerosols, are likely to have been formed by condensation
from the vapor state in the source process, and hence tend to be of fine
particle size (that is, in the low-micrometer or submicrometer range).
Control of such a material may present an entirely different problem
than does control of a gas or vapor.
Odor Measurement and Source Inventories
Although specific malodorous materials may be determined by chemical
analyses, odor itself is a physiological response of individuals, and the
only currently available instrument for measuring odors is the human
nose. 2-18 ^he perceived intensity of an odor diminishes with reduction of
the concentration of the malodorous material in the air. ~IB,-19,-20
Below a certain threshold concentration level, the odor is no longer per-
ceived. However, individuals exhibit a wide range of sensitivity
to odors, and the sensitivity of even a single individual may vary at
different times and under different circumstances. Consequently, the odor
threshold value for even a pure chemical compound is at best the average
experienced by some group of persons assembled as a test panel. »
Where odorous materials exist in a mixture they may be synergistic
or antagonistic. The perceived odor of the mixture may be intensified
22
-------
or changed in character or the odor of one component may mask the odors
of the others. If the odorous materials have widely different threshold
levels, the dominant odor may change as the odorized air is diluted.
The perceived odor intensity of a material is proportional to the
logarithm of its concentration.2'19»"22 However, the proportionality
factor between the odor intensity and the concentration is a function of
the particular material. Therefore, determining the threshold value (the
concentration corresponding to zero odor intensity) does not provide in-
formation on how the odor intensity may vary with concentration at levels
above the threshold.
Because of the logarithmic relationship between intensity and concen-
tration, reducing the odor intensity by a factor of 2 requires reducing the
concentration by a factor of 10. Consequently, eliminating an odor or
reducing it to a barely perceptible level will frequently call for ex-
tremely high efficiencies in removal of the odorous material.
Quantitative measurements of odor are made by a dilution-to-threshold
technique.2-19,-23,-24,-25,-26,-27 The strength of the odor is rated by
the number of volumes of odor-free air required to dilute one volume of
the odorous air to the threshold level. The "odor unit" is defined as
the amount of odor necessary to contaminate 1 ft^ of odor-free air to the
threshold (or barely perceptible) level.2-25 The concentration of the odor
o
in a gas sample is then defined (in odor units/ft ) by the number of cubic
feet of odor-free air required to dilute 1 ft^ of the sample to the
threshold. The total emission in odor units is the product of the odor
concentration and the flow rate -of the gas discharged to the atmo-
sphere. 2-19,-26 However, this quantititive method for determination of
odor emission is still dependent on the reactions of the persons that make
up the panel judging the threshold level.
In theory, this quantitative technique provides a basis for deter-
mining the amount of dilution required to bring the emitted odor under
threshold concentration, or the degree to which the odor must be removed
from the gas steam to deodorize it.2"18'"20 On the other hand, it pro-
vides no basis for estimating the quality of the odor, its objectionability
or acceptability, or the odor intensity of the sample at concentrations
above the threshold.2"18*'20 Thus, emission of different types from
different sources cannot be compared solely on the basis of the total
number of odor units per unit time.
In addition, experience with determination and use of quantitative
odor measurements has been variable and contradictory. ' ' '
Measurements from different sources are probably of uncertain consistency.
23
-------
The technique is not accepted universally in all odor-producing industries.
For example, the odor problems of the Kraft pulping industry are most
commonly described in terms of the mass emissions of reduced sulfur com-
pounds. Only limited data are available on odor units for different in-
dustry sources. There are, in fact, no objective means by which the odor
problems of different industries can be compared. Notwithstanding the
measured quantities of odor, public reactions are heavily dependent on
subjective factors that are not measurable.
Process Consideration in Odor Control
General methods are available for controlling essentially any
malodorous emissions from food processing. The major problem in control
is (as in most other cases of air pollution) primarily economics rather
than technology. The control techniques must certainly be adapted to the
particular application. From an economic standpoint, the major concern
is the volume of waste gas that must be treated rather than the quantity
or even the precise type of contaminant present in the gas. The volume
of gas determines the size and capital cost of the gas-treating system and
largely determines the energy costs and other operating costs. The volume
of waste gas is, in turn, determined primarily by the nature of the source
process and by the quality of the engineering devoted to the process and
emission control systems.
Many odor control and air pollution control problems in the food in-
dustries result from the continued existence of old and obsolete processing
plants. Many such plants operate on a batch basis, which usually com-
plicates the control system. Also, they were often built with no con-
sideration for future air pollution control, and hence with no provisions
for capturing escaping gases and vapors without undue dilution of the gas
streams by infiltrating air. New, modern plants can usually be designed
so that the volumes of waste gas are minimized, reducing the cost of
emission control and perhaps offering opportunities for heat recovery.
Cooking and/or partial evaporation of food products is still commonly
performed in open vessels, so that steam and volatiles, including aromas,
escape directly to the atmosphere and mix with large volumes of air
(e.g., preparation of ketchup, tomato puree). If, however, the cooking
operation is conducted in a closed vessel, the vent stream will consist
only of a relatively small volume of steam and noncondensable gases,
which will be relatively easy to treat. If the off-gas stream is vented
through a condenser, the residual gas stream requiring treatment will
consist primarily of the small volume of noncondensables.
24
-------
Food-drying operations usually present inherently greater control
problems than cooking or evaporation. Although certain products can be
dried by indirect heat transfer methods, most food products and byproducts
must be dried by direct contact with heated air or gas, which thereby
becomes contaminated with odorous materials. The minimum volume of gas
required is set by the maximum initial gas temperature that is permissible
and by the quantity of moisture that must be removed from the food product.
However, the actual quantity of gas used depends also on the design of
the drier, the amount of air infiltration, and a number of other design
and operating factors. Good engineering design of the drier system is
essential to reduce the volume of gas (and, hence, the cost of waste gas
treatment) to a minimum practical level.
Drying and roasting operations probably represent the most difficult
and expensive odor control problems in the food industry. Not only are
the gas flows generally higher than for other operations, but also the
nature of the operation promotes volatilization of the odorous materials
into the gas stream.
Another difficult problem is related to "fugitive" emissions, that is,
those escaping to the atmosphere by leakage from equipment or arising from
f\ f.
storage piles or waste ponds. Feed, product, and waste materials tend
to decompose and thereby emit malodors. Only scrupulous sanitation and
control or protection of such materials will prevent development and
emission of odors.
Odor Control Methods
Gas streams containing malodors may be treated either by removing
the malodorous material from the gas or by converting the malodors to
other materials that are not odorous.2-22,-32. In some cases, the two
methods are combined.
The malodorous materials in the food industries are almost all organic
compounds. Hydrogen sulfi.de, though not an organic compound, is at least
combustible. Sulfur dioxide is used directly in fruit sulfuring and drying,
and is formed by the combustion of other sulfur compounds such as hydrogen
sulfide. However, the threshold concentration level for detection of the
sulfur dioxide odor is much higher than for the other materials and the
odor itself is less obnoxious.
Removal of odors from gases by scrubbing with water alone is usually
ineffectual because the materials are not sufficiently soluble in water
to be removed with adequate efficiency. Water scrubbing may be useful,
nevertheless, if the gas is at elevated temperatures and contains a high
25
-------
2-6,-32
vapor concentration of a material of relatively low volatility.
The cooling and scrubbing of the gas may result in condensation and re-
moval of much of the low-volatile material; the scrubber in this case
serves primarily as a direct-contact condenser. However, any highly
volatile, water-insoluble compounds will be essentially unaffected.
Absorption of odorous compounds by aqueous solutions may be effec-
tive if the odor reacts readily with the solution; for example, hydrogen
sulfide can be absorbed with high efficiency in solutions of sodium hy-
droxide or sodium carbonate. Other organic sulfides and mercaptans are
usually not acidic enough to react strongly with the basic solutions.
Other types of malodors may result from nitrogen compounds (sometimes
amines) produced by the decomposition of animal or vegetable proteins.
The nitrogen compounds may be more or less basic, indicating that a
solution of sulfuric acid might be used as an absorption medium. However,
the nitrogen compounds may not be sufficiently basic for the reactions to
be effective.
Adsorption by active carbon is usually much more effective in odor
control than is absorption, because the adsorption equilibria are generally
more favorable and are not dependent on the water solubility of the material
being adsorbed.2-33 However, adsorption is unfavorably affected by ele-
vated temperatures and high water vapor content of the gas stream. The
usual method for regenerating the carbon for reuse is to treat it with
steam to desorb the adsorbed material. Consequently, adsorption by ac-
tive carbon is best adapted to treatment of gas streams that are at, or
only slightly above, ambient temperatures and that are not saturated with
water vapor.
The difficulty of desorbing adsorbed materials from carbon increases
with increasing adsorbate boiling point. Hence, high-molecular-weight
compounds may be particularly difficult to remove, and may require ex-
tended treatment with superheated steam, heating of the carbon under
vacuum, and other such extreme measures. Vapors of high-boiling organic
compounds that may be condensable at ambient temperatures may make the
carbon unusable. If such vapors are present in a hot gas stream, they
should be removed to the maximum degree possible by cooling and scrubbing
before the gas is admitted to a carbon bed for removal of the more volatile
materials.
The chemical conversion of malodorous organic compounds to nonodorous
materials is most effectively accomplished by combustion.^ ~22,-32 ^g
carbon and hydrogen contents of the compound are converted to carbon
dioxide and water. Any sulfur present in the malodorous compounds is
converted to sulfur dioxide, and any combined nitrogen is converted to
26
-------
elemental nitrogen or to nitrogen oxides. However, the resulting sulfur
and nitrogen oxides are normally at concentrations too low to exceed
specific allowable emission levels, much less to constitute odor problems
in themselves.
The efficiency of vapor incineration is determined by the combination
of the temperature, the hold time at temperature, and the degree of tur-
bulent mixing of the gases in the incinerator. Many air pollution codes
specify that malodorous gases (such as those from rendering plants)
should be incinerated for at least 0.5 sec at a temperature of at least
650°C. 2"23 The ease of oxidation of different compounds varies, and for
some relatively refractory high-molecular-weight materials a temperature
of at least 760°C may be required for high efficiency oxidation. At
lower temperatures, some of the material may be only partly oxidized, and
the partially oxidized material may be as obnoxious as the original
material.
The use of oxidation catalysts in vapor incinerators is intended to
initiate oxidation of the contaminants at relatively low temperatures
(e.g., 315-425°C) and thus reduce the amount of fuel that must be burned
to raise the incinerator to operating temperatures.2~^3 However, the
more refractory high-molecular-weight materials are sometimes not readily
combusted at the lower temperatures even in the presence of a catalyst.
In such a case, a catalyst may be of relatively little or no benefit in
relation to its added capital cost.
Vapor incineration is probably the most effective method of odor
control for the widest range of types and conditions of malodorous ma-
terials. However, the cost of fuel required also tends to make incinera-
tion relatively costly unless effective heat recovery can be integrated
into the system.2-32,-34 Designing an incinerator for effective odor
control is relatively easy: the major problem is providing for maximum
heat recovery. Integrating the heat recovery with the associated process
system can be most readily accomplished in the design of a new plant; it
may be difficult to incorporate in an existing plant without extensive
system modifications. The simplest method of recovering the heat is to
preheat the waste gas going to the incinerator. However, there will fre-
quently be additional recoverable heat that will be lost unless it can be
used in the process itself.
Because of the cost of thermal oxidation by incineration, there is
a continuing effort to use chemical oxidation combined with scrub-
t>ing2-6,-3l,-32,-35,-36,-37 which can be cheaper unless large quantities
of an expensive chemical oxidizing agent are required. However, the
oxidation reactions are specific to the malodorous compounds and to the
27
-------
chemical oxidizing agents, and the reactions do not proceed as far as in
thermal oxidation. Hence, chemical oxidation is neither as effective nor
as widely applicable as thermal oxidation.
The most common oxidizing agents used are sodium hypochlorite,
potassium permanganate, hydrogen peroxide, ozone, and chlorine. The
first three agents are used in solution, and can be effective only after
the malodorous material is absorbed into the solution; consequently, they
may be effective only if the malodor is fairly soluble. A sparingly
soluble material can only be removed with long gas-liquid contact times.
Also, the oxidation products must be either readily soluble and thus re-
tained in solution, or else be nonodorous so that they will not be offen-
sive if they reenter the gas stream. For best efficiency, the gas should
be prescrubbed with water for cooling and removal of condensable and
readily water-soluble materials. In this way, the relatively expensive
oxidizing agents will be consumed only in reaction with the more volatile
and refractory malodorous compounds. Potassium permanganate is to some
degree undesirable because of the precipitation of the reduction product,
manganese dioxide, which may have to be removed from the scrubbing water
before it can be discharged to a sewer. Hydrogen peroxide is favorable
in that its reduction product is water. An excess of hypochlorite may
have to be treated before water is discharged to a sewer. However, sodium
hypochlorite is much favored because it is reasonably cheap as well as
effective.
For water-insoluble malodors, it may be practical to add a gaseous
oxidizing agent (ozone or chlorine) to the gas stream to produce a gas-
phase reaction, and then scrub the gas to remove the excess reactant and
any water-soluble reaction products.2-38,-39,-40 ^ sodium hydroxide
scrubbing solution is convenient for removing excess chlorine. Excess
ozone is more difficult to deal with since it is not highly soluble in
water.
Applications of Odor Control
All the odor control methods discussed above have been used in some
part of the food industries. The rendering and fish meal industries
have received the most attention and have been most extensively covered in
the literature.2-6,-36,-41, to -47 A11 the basic control techniques have
been applied to odors from rendering, at least on an experimental basis.
Frequently, there has been no entirely unbiased report on the effective-
ness of a given method as actually applied. Since there are multiple
sources of odor in rendering plants and varying degrees of effectiveness
in capturing the contaminated air or gas for subsequent treatment, it
is not generally clear whether the performance limitations are set by
28
-------
the effictency of the odor control technique itself or by the efficiency
of preliminary captation of the malodorous air and gas. The same is
true for most other odor sources in the food industries.
Incineration is particularly favorable for treating relatively small
gas streams carrying high concentrations of malodorous materials, par-
ticularly where the gas streams are already at somewhat elevated tempera-
tures and contain water-insoluble or high-molecular-weight compounds.
If the gas stream is dilute, incineration is still effective but it gen-
erally becomes more difficult to use all the available heat in the
waste gas.
Adsorption by activated carbon is effective, but the air or gas stream
must be carefully pretreated to reduce the temperature to near-ambient
levels and to remove solids or high-boiling vapors that would clog the
bed of carbon particles or saturate the carbon with materials that would
not be readily desorbed. The spent carbon must be regenerated after a
cycle of operation. If the system is operated on a gas stream with high
concentrations of contaminant, provisions must be made to regenerate the
carbon in place. If the contaminant concentration is sufficiently low,
it may be feasible to send the carbon out to a custom regeneration service
at intervals of a month or more. Active carbon is probably best suited
for treating ventilation air from some process equipment and from buildings.
The performance of various scrubbing systems is less predictable
than that of the other control techniques. Probably only case-by-case
performance tests are capable of determining what scrubbing system, if
any, will control a given odor source. In some instances, multistage
scrubbers, with different absorbents or reactants in each stage, have
reportedly been used successfully to collect different types of malodorous
materials. - This approach requires a fairly complicated scrubber system,
but scrubbing has been favored (primarily for economic reasons) for
treating relatively large volumes of gas or ventilation air containing
moderate concentrations of odors. In other instances, scrubbing with
chemical oxidizing agents has been used even for treating smaller gas
streams containing high concentrations of odor.
Although achieving control of an odor emission in the food processing
industry obviously requires careful selection and design of the control
system, the technology for control is certainly available. The inadequacy
of many control systems in the past is related primarily to inadequate
design and engineering and to a reluctance to undertake the effort and
cost required to install an effective system. As discussed above, the
difficulty and expense of applying controls is frequently related to the
problems of fitting a control system to an old and obsolete process
system.
29
-------
For rendering plants and fish reduction plants, effective control
f\ £
actually starts with use of modern, fully enclosed process systems.^~°
Control systems have been devised also for other prominent odor sources
such as coffee roasters.2-3,-48 smokehouses,2-6 deep fat frying,2-6 and
spent-grain drying.2-38
Onion and garlic drying plants, although few in number, have presented
severe odor problems. In recent years, substantial reductions have been
achieved in the odor emissions from some of these plants, although control
is not complete. However, essentially no information has been published
on the methods adopted for control.
Onions and garlic are dried on continuous through-flow, moving-belt
conveyor driers.2-49 The onions or garlic are deposited on the belt, and
heated air is drawn through the porous mass, so that the vegetables are
dried to the desired level by the time the belt reaches the end of its
travel. The air is heated by direct firing of natural gas. The air may
flow either upward or downward through the mesh or perforated belt and
bed of vegetables; the direction of flow is usually reversed in consecu-
tive sections of the drier, and part of the air may be recirculated for
maximum utilization of heat. The maximum rate of moisture removal, and
the maximum rate of odor release occur in the first section of the drier
where the moist vegetables have been freshly deposited on the belt.
The temperature of the air used in drying must be limited to avoid
damage to the products .2-49 -j>he air temperature used in the first stage
is reported to be about 82°C. In later stages the temperature is reduced
to about 54°C or less. Because of the limitation of air temperature,
the unit capacity of the air for moisture uptake is also limited. Hence,
relatively large volumes of air must be used and exhausted in the drying
process. As is usual in such cases, the volume of exhaust air is the
principal economic problem in odor control. The rising cost of natural
gas encourages maximum use of air recirculation to maximize heat recovery.
Nevertheless, the volumes of exhaust air will unavoidably remain rela-
tively large.
2-33
Almost the only pertinent literature reference mentions the
treatment of 472x10 cu. cm/sec of exhaust air from an onion drier by beds
of activated,carbon. However, activated carbon might be better used to
treat the lightly contaminated ventilation air from the buildings. In-
cineration might be used to treat the heavily contaminated exhaust from
the first section of the drier, particularly if the vapor incinerator
could be integrated with heat recovery in the drier itself. The more
lightly contaminated exhaust from subsequent sections of the drier might
be scrubbed with sodium hypochlorite solution. The organic sulfide com-
pounds that reportedly are the main constituents of onion and garlic
30
-------
odors are probably fairly subject to oxidation in hypochlorite solutions,
but may not be very soluble in water.
Treatment of the drier exhaust gases with ozone has been proposed.
However, a substantial excess of ozone probably would be required, as in
other similar efforts at odor control by ozone. Hence, the excess of
ozone left in the air would have to be destroyed, as noted above.
At least one company has used scrubbers on the gases from its onion
driers, after a previous attempt to use activated carbon. The exhaust gas
temperature proved too high for effective use of the carbon, but the
scrubbers have evidently been quite effective.
2-50
At least one published report describes an instance in which the
emissions from ketchup and chili sauce processing kettles (falling under
SIC 2033) had to be abated. The vinegar and spice odors produced strong
complaints from- a neighboring residential community. The offgas (super-
heated steam plus the objectionable vapors) was scrubbed with cold water,
condensing about one-quarter of the steam. The removal of the odor and
acetic acid was reporte'dly nearly complete although the exit water stream
was near the boiling point. A surface condenser system achieving com-
plete condensation of the steam would probably afford higher control
efficiency as well as an opportunity for heat recovery.
Wastewater treatment plants operating on wastes from food processing
plants have frequently been sources of nuisance odors.2-12,-13,-16 At
the Sacramento (California) main wastewater treatment plant,2-12 odors
are periodically increased by the inflow of fruit cannery waste. Trick-
ling filters were provided with dome covers and the air flows from them
were treated in hypochlorite scrubbers. The hypochlorite scrubbers re-
moved most of the hydrogen sulfide, but did not remove other odors
(apparently including skatole, dimethylamine, pyridine, and methylmer-
captan) previously masked by the hydrogen sulfide. Activated carbon
adsorbers were added to the system to remove these other malodors as well
as some chlorine odors from the scrubbers.
At other similar wastewater treatment plants, scrubbing of offgases
with potassium permanganate solution is reported to have been effective
in destroying odors.2-16
Anaerobic lagoons treating meat packing wastes have been a frequent
source of hydrogen sulfide nuisance odors. Proposals have been made to
provide lagoons with flexible membrane covers and positive gas removal
systems.2-I* The offgases might be incinerated or otherwise treated to
destroy the hydrogen sulfide.
31
-------
REFERENCES
2-1 Rafson, H. J., "Odor Emission Control for the Flavor and Perfume
Industry," presented to Flavor Chemists Society, March 3, 1977.
2-2 Rafson, H. J., "Odor Emission Control for the Food Industry,"
Food Technol. 31. (6): 32-35 (June 1977).
2-3 Anon., "Roast Odors Trapped at GF/Montreal," Food Eng. 45 (10):
123-124 (October 1973).
2-4 Reding, J. T., and B. P. Shepherd, "Energy Consumption—Fuel
Utilization and Conservation in Industry," EPA-650/2-75-032d,
Environmental Protection Agency, Washington, B.C., August 1975.
2-5 Development Planning and Research Associates, Inc., "Industrial
Energy Study of Selected Food Industries," Federal Energy Ad-
ministration, Contract No. 14-01-0001-1652. Washington, D.C.
July 1974. NTIS: PB-237-316.
2-6 Danielson, J. A., Air Pollution Engineering Manual. 2nd Ed.,
Environmental Protection Agency Publication AP-40, Research
Triangle Park, N.C. (May 1973).
2-7 Thibodeaux, L. J., "A Test Method for Component Stripping of
Waste Water," EPA-660/2-74-044, U.S. Environmental Protection
Agency, Washington, D.C., May 1974.
2-8 Thibodeaux, L. J., and D. G. Parker, "Desorption Limits of Selected
Industrial Gases and Liquids from Aerated Basins," paper presented
at the National AIChE meeting in Tulsa, Oklahoma (March 1974).
2-9 Cowan, D. W., et al., "Bronchial Asthma Associated with Air Pol-
lutants from the Grain Industry," J. Air Poll. Control Assoc. JJ
(11): 546-552 (November 1963).
2-10 Weill, H., et al., "Allergenic Air Pollutants in New Orleans,"
J. Air Poll. Control Assoc. 15 (10): 467-471 (October 1965).
2-11 Public Health Service, Control and Disposal of Cotton-Ginning
Wastes, Public Health Service Publication 999-AP31, Cincinnati,
Ohio, 1967.
2-12 Herr, E., and R. L. Poltorak, "Program Goal—No Plant Odors,"
Water and Sewage Works 121 (10): 56-58 (October 1974).
32
-------
2-13 Stone, H. W., and J. V. Ziemba, "Libby, McNeill Solves an Odor
Problem," Food Eng. 45 (12): 99-100 (December 1973).
2-14 Chittenden, J. A., L. E. Orsi, J. L. Witherow, and W. J. Wells, Jr.,
"Control of Odors from an Anaerobic Lagoon Treating Meat Packing
Wastes." In: Proceedings 8th National Symposium on Food Processing
Wastes, EPA-600/2-77-184, Environmental Protection Agency, Cin-
cinnati, Ohio, August 1977, pp. 38-61.
2-15 Willoughby, E., and J. Curnick, "Controls Odors at Low Cost,"
Food Eng. 44 (10) : 107-108 (October 1972).
2-16 Boscak, V., N. Ostojic, and D. Gruenwald, "Odor Problems? Don't
Just Hold Your Nose," Water & Wastes Eng. 12 (5): 62-63, 67, 82
(May 1975).
2-17 Engelbrecht, R. S., A. F. Gaudy, Jr., and J. M. Cederstrand,
"Diffused Air Stripping of Volatile Waste Components of Petro-
chemical Wastes," JWPCF 33 (2): 127-135 (February 1961).
2-18 Turk, A., "Industrial Odor Control and Its Problems," Chem. Eng.
16 (24) : 70-78 (November 3, 1969).
2-19 Byrd, J. F., and A. H. Phelps, Jr., "Odor and Its Measurement,"
in Air Pollution, Vol. II, A. C. Stern, ed., 2nd Ed. (Academic
Press, New York, 1968).
2-20 Turk, A., "Industrial Odor Control," Chem. Eng. 77 (9): 199-206
(April 27, 1970).
2-21 Benforado, D. M., W. J. Rotella, and D. L. Horton, "Development
of an Odor Panel for Evaluation of Odor Control Equipment,"
J. Air Poll. Control Assoc. JL9 (2): 101-105 (February 1969).
2-22 Yocom, J. E., and R. A. Duffee, "Controlling Industrial Odors,"
Chem. Eng. 72 (13): 160-168 (June 15, 1970).
2-23 American Soc. for Testing and Materials, "ASTM Standard Method for
Measurement of Odor in Atmospheres," D1391-57, 1916 Race Street,
Philadelphia, Penn.
2-24 Dravnieks, A., "Measuring Industrial Odors," Chem. Eng. 81 (22):
91-95 (October 21, 1974).
33
-------
2-25 Fox, E. A., and V. E. Gex, "Procedure for Measuring Odor Con-
centration in Air and Gases," J. Air Poll. Control Assoc. 1_ (1):
60-61 (May 1957).
2-26 Mills, J. L., R. T. Walsh, K. D. Luedtke, and L. K. Smith,
"Quantitative Odor Measurement," J. Air Poll. Control Assoc.
13 (10): 467-475 (October 1963).
2-27 Schuetzle, D., T. J. Prater, and S. R. Ruddell, "Sampling and
Analysis of Emission from Stationary Sources. I. Odor and Total
Hydrocarbons, J. Air Poll. Control Assoc. 25_ (9): 925-932
(September 1975).
2-28 Byrd, J. F., H. A. Mills, C. H. Schellhase, and H. E. Stokes,
"Solving a Major Odor Problem in a Chemical Process," J. Air
Poll. Control Assoc. L4 (12): 509-516 (December 1964).
2-29 Turk, A., "Odor Source Inventories," Pollut. Eng. 4 (8): 22-24
(August 1972).
2-30 Walther, J. E., and H. R. Amberg, "Odor Control in the Kraft
Pulp Industry," Chem. Eng. Progr. J36 (3): 73-80 (March 1970).
2-31 Turk, A., R. C. Haring, and R. W. OKey, "Odor Control Technology,"
Environ. Sci. Technol. .6 (7): 602-607 (July 1972).
2-32 Beltran, M., "Engineering/Economic Aspects of Odor Control,"
Chem. Eng. Progr. 70 (5): 57-64 (May 1974).
2-33 Grandjacques, B., '*Carbon Adsorption Can Provide Air Pollution
Control with Savings," Pollut. Eng. j) (8): 28-21 (August 1977).
2-34 Herr, G. A., "Odor Destruction: A Case History," Chem. Eng.,
Progr. J70 (5): 65-69 (May 1974).
2-35 Anderson, C. E., "Chemical Control of Odors," Pollut. Eng. 4 (8):
20-21 (August 1972).
2-36 Miller, T. L., "Controlling Rendering Plant Odors," Proc. APCA
Specialty Conference on Control Technology for Agricultural Air
Pollutants, March 18-19, 1974, pp. 81-103.
2-37 Posselt, H. S., and A. H. Reidies, "Odor Abatement with Potassium
Permanganate Solutions," I & EC Prod. Res. Develop. 4 (1):
48-50 (March 1965).
34
-------
2-38 First, M. W., "Control of Odors and Aerosols from Spent Grain
Dryers," Proc. APCA Specialty Conference on Control Technology
for Agricultural Air Pollutants, March 18-19, 1974, pp. 133-146.
2-39 Quane, D. E. "Reducing Air Pollution at Pharmaceutical Plants,"
Chem. Eng. Progr. _70 (5): 51-56 (May 1974).
2-40 Riggin, C. W., Jr., "Eliminates Fermentation Odor," Food Eng. 44
(9): 145 (September 1972). ~~
2-41 Bethea, R. M., B. N. Murthy, and D. F. Gary, "Odor Controls for
Rendering Plants," Environ. Sci. Technol. T_ (6); 504-510
(June 1973).
2-42 Doty, D. M., R. H. Snow, and H. G. Reilich, "Investigation of
Odor Control in the Rendering Industry," EPA-R2-72-088, Environ-
mental Protection Agency, Washington, D.C., October 1972, 152 pp.
2-43 Osag, R. R., and G. B. Crane, "Control of Odors from Inedibles-
Rendering Plants," EPA-450/1-74-006, Environmental Protection
Agency, Research Triangle Park, N.C., July 1974.
2-44 Snow, R. H., J. E. Huff, and W. Boehme, "Odor Control by Scrubbing
in the Rendering Industry," EPA-600/2-76-009, Environmental
Protection Agency, Research Triangle Park, N.C. January 1976.
2-45 Strauss, W., "The Development of a Condenser for Odor Control
from Dry Rendering Plants," J. Air Poll. Control Assoc. J.4 (10),:
424-426 (October 1964).
2-46 Teller, A. J., "Odor Abatement in the1 Rendering and Allied In-
dustries," J. Air Poll. Control Assoc. 13 (4) : 148-149,
166 (April 1963).
2-47 Weber, R. L., and W. S. Stinson, "Recently Developed Odor Control
System Eliminates 99% of Odors, Saves $300,000 in Equipment Cost,"
Food Processing 38 (10) : 40-41 (September 1977).
2-48 Partee, F., Air Pollution in the Coffee Roasting Industry
(Public Health Service Publication 999-AP-9, Cincinnati, Ohio,
Rev. 1966).
2-49 Luh, B. S., and J. G. Woodroof, Commerical Vegetable Processing
(Avi Publishing Co., Westport, Conn., 1975).
2-50 Anon., "Controlling Processing Odors in Ketchup Operation,"
Food Production/Management, April 1974.
35
-------
SECTION 4
SOLID WASTES AND RESIDUES
RELATIVE MAGNITUDE OF THE PROBLEM
This discussion of solid wastes and residues is restricted to the
materials that are predominantly organic in nature, such as food scraps,
shells or hulls, and wastewater treatment sludges. The distinction be-
tween the terms "solid waste" and "residue" may be made precise by defi-
nition. Residues are defined here as solid by-products that have some
positive value or represent no cost for disposal. These materials that
represent a disposal cost are defined as solid wastes. These definitions,
however, do not allow simple classification. For many types of materials,
local market conditions are quite variable and the material may fall into
both categories depending on the specific site, the season of the year or
the state of the economy. Hereafter in this report we will use "solid
wastes" for all such materials.
Solid waste quantities in the food industry are quite significant.
Food industry wastes range from 0.1 to 0.2 Ib (0.045 to 0.09 kg)/capita/day
and, as shown in Figure 1, represent one of the most significant
sources (on a tonnage basis) of industrial solid wastes. The seasonal
nature of many sectors of the food industries also compounds the problem.
(By comparison, residential and commercial solid waste production averages
about 3.5 lb(1.59 kg)/capita/day and industrial sources average about
3.0 Ib (1.36 kg)/capita/day.)
Table 8 shows two separate estimates of solid waste quantities in
the total United States for manufacturing industries — one by Combustion
Engineering (the same source as Figure 1) and the other by the California
Department of Public Health. Both estimates indicate that solid wastes
from food industries represent a major portion of industrial solid wastes,
but the two studies report a considerable difference in absolute waste
magnitude. This demonstrates the difficulty in attempting to estimate
solid waste quantities for the whole nation.
California is one of the states with highly organized waste-control
programs. Table 9 shows quantitative estimates of California industrial
solid waste production3'1 made in 1969. The table shows that solid
waste generated from food industries was expected to increase from 1967
to 2000. Solid wastes from food industries are a major concern, not only
36
-------
o
n
a
«
*»
o
90,000
60,000
70,000
60,000
50,000
40,000
30,000
20,000
10,000
9,000
8,000
7,000
6,000
5,000
4,000
3,000
2,000
1,000
900
800
700
600
500
400
300
200
ion
AS)
Stock
Milfwo
Points O
4
/
Inorgor
iholt
Woo
Cott
roo
I
yards U
r
rk O
J
/
tic c
I
A
f
r
Nemi
den coi
Radio
on ginn
Meat
/
Woodc
itoine
,TV (
;y
~fj Tanning
col
n fu
r*/5*
•r
/
rnitur
Print
/
Demolition (
yO
f
«-. n n Aute
A
o F
Pop
/
r* s
•'ood
er
~ t~
Sowmill« ff __
/
\/
r
upermai
and aircraft
X) O
Other chemical
ing and publishing
kett -
10 15 20 30 40 50 60 70 80 85 90 95
Percentage of codes having
less than indicated quantity
•Standard Industrial Classification.
Source: Technical-Economic Study of Solid Waste Disposal Needs and Practices Industrial Inventory (Volume II), U.S.
Department of Health, Education, and Welfare, 1969, p. 7.
Figure 1. Distribution of waste for disposal among 21 SIC code groups.
37
-------
TABLE 8. COMPARISON OF SOLID WASTE ESTIMATES FOR
MANUFACTURING INDUSTRIES
Waste in Millions of Pounds per Year
(Total U.S.)
Combustion
SIC
No.
Industry
Engineering
Study
California
Study
19 Ordnance and accessories
20 Food and kindred products
(excludes meat packing)
21 Tobacco manufacture
22 Textile mill products
23 Apparel and textile products
24 Lumber and wood products
25 Furniture and fixtures
26 Paper and allied products
27 Printing and publishing
28 Chemicals and allied products
29 Petroleum and coal products
30 Rubber and plastics products
31 Leather and leather products
32 Stone, clay and glass products
33 Primary metal industries
34 Fabricated metal products
35 Machinery, except electrical
36 Electrical equipment and supplies
37 Transportation equipment
38 Instruments and related products
39 Miscellaneous manufacturing
(or,
711
14,260 ,
' 6
7.1 x 10 ton)
813
2,158
719
76,107
3,877
10,189
15,221
6,048
1,148
4,927
6,325
4,915
3,503
NA
43,880 „
6
(or, 21.9 x 10
-
340
650
137,660
430
2,550
1,030
5,050
5,800
2,690
-
2,830
9,800
ton)
7,660
3,047
3,479
1,665
1,696
3,300
8,400
4,640
3,080
Technical-Economic Study of Solid Waste Disposal Needs and Practices,
Volume II, Industrial Inventory. Combustion Engineering, Inc., for the
U.S. Department of Health, Education and Welfare, Public Health Service,
Clearinghouse for Federal Scientific and Technical Information, Pub. 1886,
Report SW-7c, Pub. PB-187-712, 1969.
t
California Solid Waste Planning Study. California Department of Public
Health, 1969.
Divide pounds/year by 2.2 to obtain kilograms/year.
Source: Reference 3-6.
38
-------
TABLE 9. QUANTITATIVE ESTIMATES OF SOLID WASTE PRODUCTION
FOR CALIFORNIA. 1969
Annual quantity
(millions of tons)
Type of industrial waste
Food processing
Lumber industry
Chemical and petroleum refining
Manufacturing
Total
1967
2.1
8.0
0.5
3.1
13.7
1985
3.7
2.7
0.5
4.8
11.7
2000
6.3
1.0
0.8
7.0
15.1
Source: Reference 3-1.
because of the large quantities produced, but also because of the poten-
tial for environmental pollution. Because of the organic and perishable
nature of food-industry solid wastes, the wastes can cause fly and rodent
problems, odor problems, and water pollution problems from leachate if
waste disposal sites are not well managed.
SOLID WASTE DISTRIBUTION IN THE FOOD INDUSTRIES
Solid wastes from food processing can be divided into three major
categories: (1) canned, frozen, and preserved fruits and vegetables,
(2) meat processing, and (3) miscellaneous food processing. Table 10
presents 1965-estimated quantities of solid waste from food industries in
the United States. Solid waste from the canned, frozen, and preserved
fruits and vegetables industry is the major source, representing about
75% of the total. Meat processing and miscellaneous food processing
(including dairy products, grain mill products, bakery products, sugar
and confection products, fats and oils, beverages, seafood, roasted
coffee, etc.) generate about 15% and 12%, respectively, of the total solid
wastes in the food industries. Table 11 presents 1967-estimated quanti-
ties of solid waste from food industries in California, which represent
between 20% and 25% of the total solid wastes from the U.S. food industries.
In this table, solid wastes from food processing are divided into five
categories: (1) fresh-pack fruits and vegetables, (2) canned, frozen, and
preserved fruits and vegetables, (3) meat processing, and (4) dairy industry,
and miscellaneous food processing. Fresh-pack fruits and vegetables are
not included in Standard Classification Code 20 series; this kind of waste
39
-------
is commonly classified as agricultural wastes instead of industrial wastes.
Again, Table 11 indicates that solid waste from canned, frozen, and pre-
served vegetables is the major source in the food industries with this
category representing about two-thirds of the industrial total (excluding
fresh-pack).
TABLE 10. ESTIMATED QUANTITIES OF SOLID WASTES FROM FOOD
INDUSTRY IN THE UNITED STATES. 1965
Type of Waste
Canned, frozen, and preserved fruits and vegetables
Meat processing
Miscellaneous food processing
Total
Source: Reference 3-7.
TABLE 11. ESTIMATED QUANTITIES OF SOLID WASTES FROM
FOOD INDUSTRY IN CALIFORNIA, 1967
Type of Waste
Amount
(tons)
6,120,000
1,200,000
1,010,000
8,330,000
Amount
(tons)
Fresh-pack fruits and vegetables 409,500
Canned, frozen, and preserved fruits
and vegetables 1,117,500
Canned fruits and vegetables 750,000
Frozen fruits and vegetables 170,000
Other preserved fruits and vegetables 197,500
Meat processing 100,000
Dairy industry 69,000
Miscellaneous food processing 431,000
Total 2,127,000
Source: Reference 3-8.
40
-------
TABLE 12. SUMMARY OF SIGNIFICANT PROCESS-RELATED SOLID WASTES PROBLEMS
Industry
Food Scraps
Filter or
Coagulation Aids
Others
Assessment
Category
Vegetable oil processing,
edible fats and oils
Inedible fats and oils
Livestock food (blending)
(fish meal)
Meat packing
Seafood
Canned and preserved
fruits and vegetables
Malted beverages
Roasted coffee
Sugar (cane)
(beet)
Grain milling (flour)
(rice)
(corn)
Flavoring extracts and syrups
Dairy products
Distilled liquor
Chocolate and cocoa
Wine
Baking
Cereal breakfast foods
Macaroni and spaghetti
Confections
Soft drinks
Hull, extracted flakes (X-3)
linter
Hull, extracted flakes (X-3)
Rejects (X-2)
Rejects, shell, bone (X-2)
Peels, rejects (X-l)
cores, seeds, pits
Spent grains (X-2)
Coffee grounds (X-3)
Bagasse (X-4)
Pulp (X-4)
Hull (X-3)
Rejects (X-2)
Whey (X-2)
Distiller's grain (X-4)
Stems and Pomace (X-2)
Filter aid (X-3)
Filter aid (X-3)
Paunch Manure
Filter aid (X-3)
Coagulation and
Filter aids (X-3)
Filter aid (X-3)
Filter aids (X-3)
M
M
M
H
M
H
M
M
L
M
M
H
L
M
M
L
L
M
L
L
H = high priority, M » moderate priority,_L = low priority.
Source: SRI International.
-------
RANKING OF THE SOLID WASTE PROBLEMS
In Table 12, the industries have been placed into three assessment
categories based on the magnitude of known solid wastes problems.
Category H industries represent those on which the highest priority
should be placed for the assessment. Category H industries are judged
to include canned, frozen, and preserved fruits and vegetables, meat
packing, and dairy industry. These three industries will be discussed
in more detail later. Categories M and L represent a moderate and low
priority respectively. Food industries placed in Category M include those
with moderate solid waste production such as grain milling, malt beverages,
and seafood processing. Food industries placed in Category L include
those with low solid waste production such as soft drinks and confections
and those with good waste utilization programs such as sugar and distilled
liquor. Table 13 shows current examples of good utilization technology,
and Table 14 shows examples of technology that may gain in popularity in
the future.
TABLE 13. EXAMPLES OF GOOD UTILIZATION TECHNOLOGY FOR
BY-PRODUCTS OR SOLID WASTES FROM FOOD INDUSTRIES
Industry
Solid Waste
Utilization
Sugar (cane)
Sugar (beet)
Distilled liquor
Edible fats and
oils
Bagasse
Pulp
Distiller's grain
Soybean extracted
flakes
Supplementary fuel, raw
material for insulating
and building board, paper
pulp
Cattle feed
Cattle feed
Cattle feed
Dairy industry
Whey
Animal feed, sugar prod-
uction, alcohol produc-
tion, protein supplement
Source: SRI International,
42
-------
TABLE 14. EXAMPLES OF TECHNOLOGY THAT MAY GAIN
IN POPULARITY IN THE FUTURE
Industry Solid waste Utilization
T, j., , ., „ (cakes
Edible oils Cotton |hull Cattle feed
Grain milling Rice hull Pyrolysis
Corn stalk Supplementary fuel
Fruits and Scraps Anaerobic digestion
vegetables
Source: SRI International.
CANNED AND PRESERVED FRUITS AND VEGETABLES INDUSTRY
The solid wastes generated by canned, frozen,, and preserved fruits
and vegetables industries (CPFV) come from the unit operations of wash-
ing, size grading, trimming, cutting, sorting, pitting, and peeling
processes. The solid wastes include leaves, stems, peels, pits, and mis-
cellaneous rejects.
Table 15 shows a distribution of disposal methods for canned, frozen
and preserved food wastes for 1973 in the United States. While most
solid waste is used for animal feed, significant quantities are being
disposed on land or in landfills. Possible contamination of solid wastes
by pesticides is discussed in Section 6.
TABLE 15. DISPOSAL METHODS FOR CANNED, FROZEN, AND
PRESERVED FOOD WASTES IN THE UNITED STATES.1973
Method
Landfill
Spread on fields
Animal food
Incineration
Wastewater (suspended solids)
Other
Total
Tons/year
830,000
830,000
7,080,000
18,000
320,000
220,000
9,300,000
Percent
9.0
9.0
76.0
0.2
3.4
2.4
100.0
Source: Reference 3-2. ,-
-------
Tables 16 and 17 are summaries of the solid waste quantities by
month and year, and by disposal method for individual commodities within
CPFV industry. Of the approximately 30 commodities listed, 5 commodi-
ties represent almost 757= of the total:
Waste Animal Feed
(103 tons/yr) (1Q3 tons/yr)
Citrus 3080 3000
Corn 1620 1530
White potato 1170 1040
Tomato 520 120
Pineapple 400 360
Totals 6790 6050
Except for the tomato category, approximately 90% or more of the
wastes from these commodities are used as animal feed products or
additives.
The commodities that represent over 50% of the tonnage of the CPFV
solid wastes used in landfill include tomatoes, peaches, and white potatoes.
The commodities that represent approximately 60% of the tonnage of CPFV
industry solid wastes spread on land include tomatoes, corn, citrus,
pea.ches, apples, beets, and cabbage.
Anaerobic methane fermentation may be suitable for food wastes from
caustic-solution peeling operations. Caustic solution can effect swelling
and/or solubilization of lignin and can increase the anaerobic biodegrad-
ability of food wastes. Both anaerobic digestion and pyrolysis deserve
more consideration as disposal methods for food wastes.
MEAT PACKING INDUSTRY
The largest quantity of meat processing wastes is the paunch material
from slaughtered cattle. The most common method of disposing of paunch
material is spreading it on fields, which often results in numerous fly
and odor problems. In the future other options may be considered. Anaer-
obic methane fermentation of paunch material along with other wastes
offers a promising solution to the paunch manure problem and deserves
more research.
44
-------
TABLE 16. INDUSTRY SOLID RESIDUES BY PRODUCT AND MONTH
Product
Asparagus
Lima bean
Snap bean
Beet
Broccoli, sprouts,
cauliflower
Cabbage
Carrot
Corn
Greens, spinach
Mushroom
Pea
White potato
Pumpkin/ squash
Tomato
Vegetable, misc.
Apple
Apricot
Gi Berry
Cherry
Citrus
Fruit, misc.
Olive
Peach
Pear
Pineapple
Plum, prune
Dry bean
Pickle
Specialty
Clam, scallop
Oyster
Crab
Shrimp
Salmon
Sardine
Tuna, misc. seafood
TOTAL
Nonfood items
Jan
2
7
4
6
2
3
99
7
11
28
X
X
330
X
1
25
1
1
X
26
1
3
2
5
X
X
7
570
39
Feb
6
4
3
2
3
90
7
12
21
X
X
330
X
1
25
1
1
X
26
1
3
2
7
X
X
7
550
38
Mar
4
7
4
4
8
3
92
6
12
15
X
X
330
X
X
30
1
1
X
26
1
2
2
7
X
1
7
560
40
Apr
14
2
2
7
3
5
7
3
1
86
6
11
5
X
X
330
X
50
X
1
X
26
1
2
2
6
X
1
7
580
43
May
14
2
1
6
2
4
3
3
5
90
10
17
4
X
X
330
1
X
55
X
X
25
1
X
1
8
X
X
8
590
43
Jun
9
X
7
1
7
1
5
8
1
3
25
62
70
19
6
3
1
330
3
X
23
55
1
X
8
24
1
2
5
8
1
8
700
55
Jul
2
X
37
9
5
9
70
2
28
69
1
140
30
7
3
13
210
4
X
84
14
55
X
X
9
23
1
1
5
12
1
9
860
69
Aug
X
5
41
16
13
8
10
620
X
2
11
100
12
150
38
2
4
11
100
8
99
33
55
X
X
8
24
1
2
5
10
1
10
1400
76
Sep
8
35
18
13
14
23
590
2
2
1
110
10
110
36
33
2
100
9
2
83
39
30
1
X
8
24
1
2
5
8
1
10
1330
78
Oct
5
9
22
16
16
33
280
2
3
X
130
22
6
38
53
X
160
8
3
3
25
25
1
1
6
25
1
2
2
5
2
X
9
920
73
Nov
X
1
14
16
14
26
48
3
3
X
130
10
6
32
64
210
2
3
6
X
1
X
25
1
2
2
5
X
X
9
640
49
Dec
X
3
10
7
12
2
3
X
120
16
56
330
1
X
X
1
X
26
1
3
2
5
X
7
600
43
Total
42
19
130
90
110
76
140
1620
33
32
74
1170
55
520
270
290
16
14
26
3080
36
11
290
120
400
7
7
41
300
13
18
22
66
40
6
99
9310
650
Total
Raw
Tons
120
120
630
270
260
230
280
2,480
240
67
580
3,570
220
6,970
1,220
1,050
120
200
190
7,800
150
85
1,100
410
900
27
230
560
2,500
90
20
30
120
124
26
520
33,500
All figures x 1000 tons; rounded (after adding);
Source: Reference 3-3.
500 tons or less
-------
TABLE 17. INDUSTRY SOLID RESIDUES BY PRODUCT AND DISPOSAL METHOD
ON
Product
Asparagus
Lima bean
Snap bean
Beet
Broccoli, sprouts,
cauliflower
Cabbage
Carrot
Corn
Greens, spinach
Mushroom
Pea
White potato
Pumpkin/squash
Tomato
Vegetable, misc.
Apple
Apricot
Berry
Cherry
Citrus
Fruits, misc.
Olive
Peach
Pear
Pineapple
Plum, prune
Dry bean
Pickle
Specialty
Clam, scallop
Oyster
Crab
Shrimp
Salmon
Sardine
Tuna, misc. seafood
TOTAL
Nonfood items
Total
Raw
Tons
120
120
630
270
260
230
280
2,480
240
67
580
3,570
220
6,970
1,220
1,050
120
200
190
7,800
150
85
1,100
410
900
27
230
560
2,500
90
20
30
120
120
26
520
33,500
Fill
8
1
35
18
12
19
6
3
5
4
3
57
8
250
38
35
4
4
15
4
13
130
40
30
4
3
37
37
8
S
830
300
Spread
16
8
32
46
9
44
30
86
3
28
22
28
13
130
71
54
2
5
5
76
13
1
56
32
2
2
3
3
4
1
4
830
17
Burn
x
X
X
X
4
1
X
X
X
8
3
18
97
Total
as
Solid
24
10
67
65
21
64
36
89
8
32
24
85
22
380
110
90
6
10
20
80
25
2
180
72
30
6
6
40
48
12
6
7
0
0
"o
1680
410
Water
x
42
21
x
X
2
13
10
5
1
x
2
16
29
35
x
180
x
Pond
x
6
x
2
x
7
1
x
X
X
X
7
24
32
Sewer
3
6
1
2
2
x
4
9
x
52
x
x
1
X
5
x
1
18
12
120
Total
Irriga- in
tion Liquid
0
0
3
6
1
6
2
1 3
x
x
0
48
9
1 30
52
x x
X
2
1 1
1 1
X
X
x 14
10
10
1
x
1
x 24
x
2
16
41
35
0
x
5 320
32
Feed
19
10
64
18
91
6
100
1530
24
49
1040
24
120
110
110
7
1
4
3000
8
50
36
360
x
2
210
16
4
69
7080
metal
130
Other
x
x
2
87
2
x
3
2
10
44
17
16
x
2
6
30
220
other
67
Total
By-
Product
19
10
64
18
91
6
100
1530
24
0
49
1040
25
120
110
200
9
1
4
3000
10
10
94
36
360
0
2
0
230
0
16
0
17
6
6
99
7300
200
Not
Total Accounted
Residuals
42
19
130
90
110
76
140
1620
33
32
74
1170
55
520
270
290
16
14
26
3080
36
11
290
120
400
7
7
41
300
13
18
22
66
40
6
99
9310
650
For
3
(-3)
0
21
x
(-1)
10
42
4
(-2)
4
170
97
150
x
30
5
2
1
310
3
x
(-19)
14
0
1
(-1)
(-15)
0
65
x
1
20
3
x
91
1010
-
All figures x 1000 tons; rounded (after adding); x * 500 tons or less.
Source: Reference 3-3.
-------
DAIRY INDUSTRY
Dairy whey is a by-product from the manufacture of cheese that has
potential as a chemical feedstock. It contains 72% to 757, lactose,
which is a reducing dissaccharide composed of two hexose units, glucose
and galactose.
CH2OH
H 6H
(glucose) (galactose)
P-lactose
The balance of whey is proteins, minerals, and water. An analysis of
dried whey is shown below:
Lactose
Protein (N x 6.25)
Minerals
Fats
Moisture
Fiber
Dried Whey
67.7 %
12.0
10.0
1.0
4.5
None
Whey has evolved from waste product status to a self-supporting
industry with markets in the food, feed, and pharmaceutical industries.
It is currently estimated that about 2 billion pounds of whey solids are
being generated annually,3"9 only two-thirds of which are being recovered
and used in commercial products.
47
-------
MISCELLANEOUS FOOD PROCESSING
Filter Aids and Adsorbents
Of the nonfood scrap-type solid wastes, activated carbon and
diatomaceous earth are two of the largest process solid waste products
from the food industries. In 1972, activated carbon consumption for
sugar decolorization was approximately 22.7 million kilograms (25,000 tons)
whereas fats and oils, and other foods and beverages consumed 3.2 million
kilograms (3,500 tons), as shown below.
Corn sugar
Cane sugar
Beet sugar
Fats and oils
(Remove odor or color and
colloidal impurities
Refining of juices, gelatin,
pectin, and vinegar
Alcoholic beverages
(wine, whiskey, vodka, others)
10 Kg/Yr
16
4.5
1.8
2.27
Tons/Yr
18,000
5,000
2,000
2,500
0.91
1,000
Powdered activated carbon accounts for 75-80% of the total consump-
tion, and since powdered activated carbon is rarely regenerated because
of inadequacies in current technology, practically all of the powdered
carbon consumed ends up as a solid waste stream. Granular carbon accounts
for 20-25% of the total consumption. Some of the granular carbon consumed
is discarded as a so-lid waste without regeneration and some of the
granular carbon consumed represents makeup to replace oxidation losses
in systems where thermal regeneration of spent carbon is practiced. If
it is assumed that 50% of the granular carbon consumption represents make-
up for regeneration systems, then from 25,000 to 26,000 ton/year of
activated carbon is disposed of as solid waste.
Diatomaceous earth is widely used as a filter aid in food industries
such as sugar, fats and oils, malted beverages, wine, and distilled
3—4
liquor. The Bureau of Mines reported that the total consumption of
48
-------
diatomaceous earth in 1973 for filter use in food industries, pharmaceu-
tical industry, and municipal water processing was 262 x 103 tons.
According to Cummins, " in order of tonnage consumed, filter aids are
used primarily for sugar refining, food products, pharmaceutical uses,
and water treatment. It is estimated that the usage of diatomaceous
earth in food industries in 1973 was between 131 x 103 and 262 x 103 tons.
Waste filter aids probably represent about 7% of the total solid waste
for food industry.
Sludge from Biological Treatment of
Food Processing Wastewater
Biological treatment of food processing wastewaters results in
quantities of biological sludge. The handling of excess sludge is both
a technical difficulty and an economic burden. Biological sludge often
is hauled away for land disposal. Several recent studies have been
concerned with the use of dried sludge as an ingredient in a poultry
or cattle feed. This procedure may represent a cost-effective and en-
vironmentally acceptable means for handling sludge. The following
are two examples of such studies.
Snokist Growers, located at Yakima, Washington, operates a cannery
that processes pears, apples and other fruits on a seasonal basis. The
cannery can process approximately 270 metric tons of pears per day and
about 90 metric tons of apples per day during the processing season. The
wastewater treatment system at the plant is an activated sludge process
and produces quantities of excess biological solids. The present dis-
posal cost by dewatering and land disposal is approximately $0.07/kg
dry solids; disposal of the average 300,000 kg of excess biological solids
produced per season is a substantial expense for the processor. In addi-
tion, land disposal of sludge may present environmental problems.
During the 1974 processing season, Snokist Growers conducted a project
to study sludge dewatering and use by incorporation into a cattle feed
ration. 3-4 The inclusion of dewatered biological sludge in a cattle feed
ratio did not appear to impair the metabolizability or digestibility of
the ration at approximately 5 percent or less biological sludge on a dry
matter basis. Carcass quality of the cattle fed on rations containing
biological sludge up to a level of 9 percent on a dry matter basis was at
least equivalent to that of controls, and possibly improved when the level
was 2 to 5 percent of the ration solids. Moreover, the inclusion of dried
sludge in cattle feed is more economically advantageous than the present
land disposal method.
49
-------
In the Florida citrus industry, activated sludge process is widely
used for wastewater treatment. The handling and disposal of excess
activated sludge results in one of the largest operating expenses in the
activated sludge process. The Winter Garden Citrus Products Cooperative,
under Grant S-801432 sponsored by the EPA, has evaluated the potential
of utilizing waste activated sludge as a poultry feed supplement.^"5
The study showed that the inclusion of up to 7.5 percent sludge in
properly formulated diets did not significantly affect poultry perfor-
mance or meat or egg quality. Moreover, the value of the recovered
sludge significantly reduced the total cost of sludge handling. Addi-
tional work is currently underway on the concept.
50
-------
REFERENCES
3-1 California State Department of Public Health, "A Program Plan for
Solid Waste Management in California," January 1970.
3-2 Cornelius, James, "Production and Disposal of Industrial Solid
Wastes in California," California Vector Views, 16. (5): 35 (May
1969).
3-3 Katsuyama, A. M. , Olspn, N. A., Quirk, R. L., and Mercer, W. A.,
"Solid Waste Management in the Food Processing Industry," PB-219 019,
NTIS, 1973.
3-4 Esvelt, L. A., Hart, H. H., and Heinemann, W. W., "Cannery Waste
Biological Sludge Disposal as Cattle Feed," JWPCF, 48 (12): 2778
(December 1976).
3-5 Jones, R. H., White, J. T. , and Damron, B. L., "Waste Citrus
Activated Sludge as a Poultry Feed Ingredient," EPA Grant No.
66012-75-001, February 1975.
3-6 EPA Report No. 670/2-73-14, "A Study of Hazardous Effects and
Disposal Methods," Volume I (1973).
3-7 Combustion Engineering, Inc., "Technical-Economic Study of Solid
Waste Disposal Needs and Practices," Vol II, Industrial Inventory,
Report for U.S. Department of Health, Education and Welfare, 1969,.
3-8 Cornelius, J., "Production and Disposal of Industrial Solid Wastes
in California," California Vector Views, U), 5 (May 1969).
3-9 "Fermentation Process Turns Whey Into Valuable Protein," Chemical
Engineering, 36-38 (March 17, 1975); "Enzymes May Milk Dairy
Wastes," Chemical Week, 37-38 (November 14, 1977); "Dutch Make
Alcohol From Whey," Chemical Engineering, 60 (November 7, 1977).
51
-------
SECTION 5
WATER POLLUTION PROBLEMS
This section compares the water pollution problems in the food in-
dustries with those of other nonfood industries. Water pollution pro-
blems are ranked within the food industries and those food industries
with major water pollution problems are described. The wastewater
characteristics and volume from major commodities and unit operations
are further reviewed in Appendices A - H.
RELATIVE MAGNITUDE OF THE PROBLEM
Several important points to consider when evaluating the relative
impact of the food processing industries on water pollution in the United
States are that almost all of the waterborne wastes from the industry
are highly biodegradable, and that a high percentage of the food pro-
cessing plants discharge their wastewater to municipal treatment systems
or to onland treatment systems. Even though a large portion of the
wastewaters from these food industries are not discharged directly to
bodies of water, these industries do represent a significant group of
point source dischargers. In the National Water Quality Inventory;
1974 Report to the Congress (EPA-440/9-74-001), it was shown that food
industries represent approximately 10% of the"major"and 10% of the
'minor"industrial point source discharges to surface waters (see Table 18).
In terms of the number of'major"point source discharges, the food indus-
tries rank fourth as a category behind chemical and allied products,
paper and allied products, and electric and gas utilities. On the
average, the BOD,- and suspended solids concentrations in wastewaters from
food processing plants are considerably greater (by a factor of 10) than
those of domestic sewage. This fact is very significant because of the
large number of food processing plants that discharge to municipal treat-
ment plants in moderate or small size communities. Even in some large
cities like St. Louis, MO, Milwaukee, WI (brewers), Sacramento, CA, and
San Jose, CA (fruit and vegetable processors), food industries contribute
a very substantial portion of the BOD load in wastewater treatment plants.
The average wastewater flow from all food processing industries in the
United States is about 60.6 liters/capita/day as compared to per capita
municipal loads of about 454.2 liters/capita/day. BOD and suspended
solids loads from the food processing industry wastewaters are equivalent
*
Biochemical oxygen demand measured over a 5-day period.
52
-------
TABLE 18. INDUSTRIAL DISCHARGES BY INDUSTRY GROUP
Industry
Agriculture - crops
Agriculture - livestock
Agriculture - other
Metal raining
Coal mining
Oil and gas mining
Nonmetallic mineral mining
Meat products
Dairy products *
Preserved fruits and vegetables*^
Grain mill and bakery products
Sugar and confectionary product?
Seafood products ^
Miscellaneous food and beverages
Textiles
Lumber and wood products
Paper and allied products
Printing and publishing
Chemicals and allied products
Petroleum and coal products
Rubber and miscellaneous plastics
Leather and leather products
Stone, clay, and glass products
Iron and steel
Nonfenous
Miscellaneous primary metal products
Fabricated metal products
Electric and nonelectric machinery
Transportation equipment
Other manufacturing
Railroad transportation
Other land transportation
Water transportation
Air transportation
Miscellaneous transportation
Communication
Electric and gas utilities
Water and sanitary services
Wholesale and retail trade
Finance, insurance, and real estate
Other services
Government
Nonclassifiable
Totals
Food Industries Totals
Major
2
4
19
45
44
28
62
54
11
50
16
78
39
57
151
31
407
0
522
136
15
29
71
142
66
4
149
39
49
6
9
0
0
3
3
0
392
22
4
0
1
24
17
2.801
305
Number of surface water dischargers
Minor
32
26
347
396
1,154
1,226
1.034
299
349
330
118
61
598
377
458
477
255
50
821
279
380
26
1.041
281
247
41
742
675
277
192
355
132
102
30
46
9
2,397
1,504
1,166
309
1,069
616
1,344
21,668
2,132
Total
1A
34
1A
JU
1££
JOO
AA\
^1
1 tOft
1«170
1 254
»(*j*t
1,0%
353
360
380
i?OV
134
139
638
434
608
508
662
50
1,343
415
395
55
1,112
423
313
45
891
714
326
198
364
132
102
33
49
9
2,789
1,526
1.170
309
1,070
640
1,361
24,469
2,438
Food Industries .
Source; Reference 4-1.
53
-------
to about 0.05 kg/capita/day and 0.7 kg/capita/day, respectively, as com-
pared to 0.08 kg/capita/day and 0.09 kg/capita/day for untreated domestic
sewage
Table 19 shows estimated of wastewater volume, BOD,., and suspended
solids loads for all major water-using manufacturing industries, and
TABLE 19. ESTIMATED VOLUME, BOD , AND SUSPENDED SOLIDS
FOR INDUSTRIAL WASTEWATERS, BEFORE TREATMENT, 1964
Industry
Food and kindred products
Textile mill products
Paper and allied products
Chemical and allied
products
Petroleum and coal
Rubber and plastics
Primary metals
Blast furnaces and steel
mills
All other
Machinery
Electrical machinery
Transportation equipment
All other manufacturing
*
All manufacturing
For comparison:
Sewered Population of US
*
Waste-
water
volume
Q a
(10y gal)
690
140
1,900
3,700
1,300
160
4,300
3,600
740
150
91
240
450
A
13,100
5 , 300+
Process
water
intake
o a
(109 gal)
260
110
1,300
560
88
19
1,000
870
130
23
28
58
190
3,700
BOD,5 b
(10 Ib)
4,300
890
5,900
9,700
500
40
480
160
320
60
70
120
390
22,000
i
7,300
Suspended
solids.
(106lb)
6,600
N. E.
3,000
1,900
460
50
4,700
4,300
430
50
,20
N. E.
930
18,000
8.8008
Columns may not add, due to rounding.
120,000,000 persons x 120
gal x 365 days •
"120,000,000 persons x 1/6 Ib x 365 days.
120,000,000 persons x 0.2 Ib x 365 days.
Includes cooling water.
a) 1 gallon equals 3.785 liter-
b) 1 pound equals 0.454 kilograms.
Source: Reference 4-2.
54
-------
Table 20 shows the 1964 rankings of industries based on total wastewater
volume, BOD5 load, and suspended solids load, respectively. Table 20
indxcates that although food industries produce a medium ranked volume
of wastewater among the manufacturing industries, they produce high
loads of raw BODs and suspended solids.
TABLE 20. RANKING OF INDUSTRIAL WATER POLLUTION
PROBLEMS BY INDUSTRY, 1964
Based on total
Based on
BODr loads
Based on suspended
solids loads
_/
Industry wastewater volume (before treatment) (before treatment)
Metal and metal
products
Chemical and
allied products
Power production
Paper and
allied products
Petroleum and coal
Food and
kindred products
Machinery and
transportation equip.
Stone, clay, and
glass products
Textile mill products
Lumber and
wood products
Rubber and
plastic products
Miscellaneous
industrial sources
Joint industrial-
municipal wastes
Feed lots
Other (cost benefits,
residuals)
2
N.A.
3
4
8
10
11
9
1
N.A.
2
5
4
N.A.
3
6
N.A. = not available.
Source: Reference 4-3.
55
-------
WASTEWATER DISTRIBUTION IN THE FOOD PROCESSING INDUSTRIES
Table 21 presents estimated wastewaters volumes and contaminant
loads for 1964 for the U.S. food industries, which are divided into five
major categories. In 1964, sugar refining had the highest wastewater
load with both wastewater volume and BOD load equal to one-third of the
total for all the food industries. Suspended solids loadings from sugar
refining represented two-thirds of the total industry load. Wastewaters
from canned, preserved, and frozen fruits and vegetables, meat products,
and dairy products were also very significant.
TABLE 21. ESTIMATED QUANTITIES OF WASTEWATER VOLUME AND LOADS
FROM FOOD INDUSTRIES IN THE UNITED STATES, 1964
Industry
Meat products
Dairy products
Canned, preserved,
and frozen food
Sugar refining
Miscellaneous
Wastewater
vo lume
(109 liters)
375
220
329
833
833
2,590
BOD
(106 kg)
291
182
545
636
305
1,959
Suspended
Solids
(106 kg)
291
105
273
2,273
50
2,992
Source: Reference 4-2.
Table 22 presents estimated volume and loads of wastewater for
1974 in U.S. food industries. Comparison of Tables 21 and 22 shows the
following:
(1) Estimated wastewater volumes and BODg loads from the
sugar refining industry decreased significantly from
1964 to 1974. This is due to great improvements in
in-plant practices, process-water reuse, sugar recovery'
56
-------
However, the sugar refining industry is still the major
source of suspended solids load in the food industries.
(2) The CPFV industry produces the largest volume of waste-
water in food industries.
(3) The meat industry and the malt beverage industry pro-
duce the major portion of the food industries' BOD load.
TABLE 22. ESTIMATED QUANTITIES OF WASTEWATER VOLUME AND RAW
LOADS FROM MAJOR FOOD INDUSTRIES IN THE UNITED STATES, 1974
Wastewater
volume
Category Industry (109 liters)
H .
'Meat
Dairy
CPFV
Sugar
Malt beverage
*• Seafood
Grain milling (xjet corn)
M <
Malt industry
Flavoring, extracts,
syrups
Distilled liquor
( Soft drink
L {
(Coffee
307
212
492
341
151
49
0.04
19
NA
6.74
18
1.89
BODC Suspended
5 solids
(106 kg) (106 kg)
331
182
91
68
205
45
47
12
11
4.68
4.05
1.8
NA
91
68
455
82
43
24
2.27
0.91
4.68
-
0.45
Notes: N.A = not available.
H = High priority, M = moderate priority, L = low priority.
Source: Reference 4-4.
57
-------
RANKING OF RAW WASTEWATER LOADS
In Table 23, the industries have been placed into three categories
based on the magnitude of known raw wastewater loads, using the data on
wastewater volume, BOD , and suspended solids from Table 22. Category
H (high priority) industries include CPFV, meat, dairy, sugar, malt
beverage and seafood. Four of these industries will be discussed in more
detail in the following sections. Categories M and L represent moderate
and low priority industries, respectively.
WATERBORNE TOXIC POLLUTANTS
The possible waterborne toxic pollutants in the food industry may
include pesticides that are removed from the surface of commodities
during washing operations, solvents used for extraction (see Appendix C
on chlorinated hydrocarbons), PAH contained in wastewaters from washing
of smokehouses (see Appendix B on PAH), disinfecting chemicals and fungi-
cides applied to commodities or used in the washing of vessels and other
equipment, and naturally occurring phenolic compounds present in specific
commodities (See Appendix E on Citrus Processing). The most pervasive
waterborne sources of toxics in the food industry are the washing opera-
tions (and perhaps certain other wastewaters such as blanching water
and flume water). Certain commodities are stored after harvesting to
allow actual processing to proceed over a period of several months or
until the next harvest. Pesticides are required for the storage of
certain commodities. An example of this problem was reported for sweet
potato processing and is discussed in Appendix F.
WATER REUSE AND RECYCLING
Cascading water use or countercurrent water use systems (where
an operation requiring relatively low quality water uses wastewater from
another operation) or recycling systems (where water is treated and
returned to the same operation) can greatly reduce the intake water re-
quirements for a food processing plant. To date the issue of water reuse
or recycling in food processing has often been handled on a case-by-
case basis. The U.S. Food and Drug Administration (FDA) and the U.S.
Department of Agriculture (USDA) have responsibility for setting manu-
facturing standards for specific food processing operations. The FDA
specifies that "any water that contacts foods or food-contact surfaces
shall be safe and of adequate sanitary quality." This apparently flexible
standard applies to non-meat and non-poultry processing operations and
will allow the implementation of water reuse or recycle systems. In such
cases the last washing of the product is usually done with potable water.
USDA is responsible for meat and poultry processing operations and speci-
fies that "potable water" be supplied to the plants by these processors,
and water reuse is considered on a case by case basis.
58
-------
TABLE 23. SUMMARY OF SIGNIFICANT WASTEWATER PROBLEMS
VO
Industry
Meat packing
Seafood
Canned and preserved
fruits and vegetables
Malted beverages
Roasted coffee
Sugar (cane)
(beet)
Grain milling (flour)
(rice)
(corn)
Flavoring extracts and syrups
Dairy products
Distilled liquor
Assessment
H
H
H
H
L
H
L
L
M
M
H
M
Wastewater
Volume
X-l
X-2
X-l
X-l
X-3
X-l
X-3
X-3
X-3
N.A.
X-l
X-2
BOD^ Load
X-l
X-2
X-l
X-l
X-3
X-l
X-3
X-3
X-l
X-2
X-l
X-2
Suspended
Solids Load
X-l
X-2
X-l
X-l
X-3
X-l
X-3
X-3
X-l
X-3
X-l
X-2
N.A. = not available.
H = high priority, M = moderate priority, L =
X-l = major; X-2 = significant; X-3 = minor.
Source: SRI International.
low priority.
-------
Research and development work on wastewater reuse for a cannery
and a poultry processing plant has been done by both Snokist Growers
and the Maryland State Department of Health, and is discussed in more
detail in Appendices G and H, respectivelv.
CANNED, FROZEN, AND PRESERVED FRUITS AND VEGETABLES INDUSTRY (CPFV)
The CPFV industry is an excellent example of a complex industry that
is a major source of water pollutants. The industry basically extends
the shelf life of raw commodities through the use of various preservation
methods such as canning, freezing, dehydrating, and brining. It is diffi-
cult to give a general description of the wastewater problems of the
CPFV industry because there is a great diversity in geographical location,
size of plant, and number of products processed (See Appendices 8, 9, 10
on CPFV.) Whereas other industries such as the organic chemicals indus-
try may have a wider range of products and a comparable number of plants,
the CPFV industry is unique in the seasonal variation of the waste loads
and the need to meet high sanitation standards in compliance with state
and federal laws.
The wastewater pollutants generated by the CPFV industry result pre-
dominantly from the unit operations of transport, peeling, washing, and
blanching. Table 24 shows the sources and estimated average volumes of
wastewaters from processing steps in the canning of fruits. The volumes
TABLE 24. SOURCES AND ESTIMATED VOLUMES OF WASTEWATERS
FROM PROCESSING STEPS IN CANNING OF FRUITS
(Highly variable by commodity)
Waste Flow (liters) Percent of
Operation
Peeling
Spray washing
Sorting, slicing, etc.
Exhausting of cans
Processing
Cooling of cans
Plant cleanup
Box washing
Total
per hour
4,542
41,635
11,355
4,542
2,271
90,840
79,485
7,149
241,819
per ton
48
385
120
48
24
945
840
70
2,480
total flow
2
17
5
2
1
37
33
3
100
Source: Reference 4-5.
60
-------
given are those that result if only fresh water is used in all operations
and no attempt is made to reuse water. The volumes may be greatly reduced
by recycling; for example, can cooling is now accomplished at some plants
using recirculated cooling water systems.
Table 25 shows a 1975 SRI classification of the major commodities
in terms of total raw wastewater flow, raw BODc, and suspended solids
loads, based on EPA data. (This table was developed to aid in evalu-
ating past EPA research and development funding priorities.)
TABLE 25. RANKING OF MAJOR COMMODITIES
BY SIGNIFICANCE OF RAW WASTE LOAD
Classification Commodity
Highest Priority Citrus, frozen and dehydrated potatoes,
12-15 tomatoes, corn, pineapple, peaches, peas
High Priority Green beans, pickles, pears, prunes
9-11
Medium Priority Apples, spinach, beets, carrots, broccoli,
6-8 apricots, canned dry beans, cauliflower, sweet
potatoes, canned white potatoes
Low Priority Grapes, cherries, mushrooms, asparagus, lima
4-5 beans, olives
Lowest Priority Sauerkraut, blueberries and caneberries,
3 pimentos, plums, onions.
Source: Reference 4-6.
In a study supported by the National Commission on Water Quality (NCWQ),
Environmental Associates ranked the various commodities using the para-
meters and weighting factors shown in Table 26; these were selected on
the basis of environmental and economic impacts. (The parameters in
Table 26 were selected from a list of parameters that included "signi-
ficance of toxic pollutants discharged.")
61
-------
TABLE 26. IMPORTANCE PARAMETERS AND WEIGHTING FACTORS
FOR RANKING COMMODITIES
Importance Weighting
parameter factor
Total organic load 0-4
Number of point sources 0-4
Total hydraulic load 0-3
Number of surface water dischargers 0-2
Number of single activity plants 0-2
Intermedia problems 0-1
Climatic factors 0-1
Season length 0-1
Style variations 0-1
Activity sophistication 0-1
Higher values indicate greatest environmental or economic impact,
Source: Reference 4-7.
Table 27 clearly shows that one may expect wide variations on
unit wastewater quantities and strength from plant to plant.
The CPFV industry was subdivided into the following three groups in
the NCWQ study, using the weighting process previously described:
Group A - Those activites not considered worthy of further
study because of insignificant pollutional impacts
Group B - Those activites that could be adequately assessed
by refining and updating data currently available from EPA
Group C - Those activities involving either; (1) major pol-
lutant discharges, or (2) outstanding examples illustrating
important economic, technological, and/or environmental
issues, and therefore, warranting analysis in greater detail
than can be achieved with the existing EPA data.
Table 28 is a summary of the results of this categorization task.
(SRI's ranking for those commodities considered in the SRI project are
62
-------
TABLE 27. COMPARISON OF EPA AND NCWQ CONTRACTOR'S
RAW WASTE VALUES
EPA Data
NCWQ Data,.
*'±OW BODS TSS" Flow BOD 5 TSS"
ratio ratio ratio ratio ratio ratio
Commodity (gal/ton) (Ib/ton) (Ib/ton) (Ib/ton) (Ib/ton) (Ib/ton
Apple juice
Apple
products
Brined
cherries
Citrus
products
Carrots
Grapes
pressing
Frozen
potatoes
Onions
Squash
Blackberries and
caneberries
Green beans
Cherries
Corn
Peaches
Plums
Pears
Strawberries
Tomatoes
Dehydrated
potatoes
Grape juice
canning
690
1290
3690
2425
2940
410
2710
4830
2890
1710
3280
3130
1790
3000
1010
3470
3420
2210
2100
1410
4,1
12.8
68»1
6,4
28.9
4o03
45o8
57.3
2905
6o52
5,91
3006
27=3
29,5
9,, 52
52,8
13.6
9o3
22,1
13.9
0=6
1.6
3.28
2,6
15 = 6
0,749
38.8
17=1
13,1
1U41
4.44
1=84
9ol2
8.27
0=893
12.7
4.06
12 o 3
17,2
2.60
660
1660
4790
385
2770
304
2430
10900
2360
2760
3410
3200
1610
2990
984
3200
3870
2450
2040
1570
4.02
20,0
42.1
3.56
29.0
2,91
37.8
41.4
24.2
10.8
6.30
26.5
25.5
31.0
8.79
52.3
15.7
9.58
21.5
10oO
0.555
1.49
4.19
0.827
17.6
0.724
29.8
22.2
10.7
2,72
5,14
1.7
8.38
8.61
0.666
10.8
4.93
12.3
15.4
2.84
Total suspended solids.
Source: Reference 4-7.
Note: Convert gal/ton to liters/ton multiply by 3.785; convert Ib/ton
to kilograms/ton multiply by 0.4545.
63
-------
TABLE 28. RESULTS OF IMPORTANCE MATRIX ANALYSIS
Commodity
Rhubarb
Artichokes
Okra
Caneberries
Pimientos
Grapes
Soup mixes
Brussels sprouts
Fruit cocktail
Strawberries
Asparagus
Broccoli
Greens
Sweet cherries
Cranberries
Cauliflower
Mushrooms
Spinach
Plums
Blueberries
Baby food
Dried vegetables
Brined cherries
Lima beans
Squash
Onions
Nationality foods
Sauerkraut
Apple juice
Group
A
A
A
A (L)+
A (L)
A (L)
A
A
A
A
A (L)
A (M)
A
A (L)
A
A (M)
A (L)
A (M)
A (L)
A (L)
B
B
B
B (L)
B
B (L)
B
B (L)
B (M)
Commodity
Apricots
Carrots
Frozen corn
Jam, jelly
Prunes
Olives
Tomatoes (peeled)
Dry fruit
Dehydrated potatoes
Dressings, sauces
Beets
Canned potatoes (white)
Pears
Pineapples
Apple products
Canned soup
Dry beans
Green beans
Sweet potatoes
Misc. canned specialties
Canned corn
Tart cherries
Peas
Peaches
Pickles
Frozen potatoes
Tomato (concentrate)
Citrus products
Group
B (M)
B (M)
B
B
B (H)
B (L)
B
B
B (H)
B
B (M)
B (M)
B (H)
B (H)
C (M)
C
C (M)
C (H)
C (M)
C
C (H)
C
C (H)
C (H)
C (H)
C (H)
C (H)
C (H)
The commodities are defined more completely in Appendices 1-18.
SRI Rankings are based solely on raw wastewater loads and volume of flow:
(H) high priority, (M) moderate priority, (L) low priority.
Source: Reference 4-7.
-------
also indicated.) Because many plants in the CPFV process more than one
commodity and may produce numerous types of products from individual
commodities, the NCWQ report subcategorized the industry as shown in
Table 29.
From the data in Table 29, it is clear that the industry has no
general rules for wastewater treatment. Single-commodity plants (many
very large) such as corn processors, citrus processors, pickle pro-
ducers, potato processors, and sauerkraut producers are more likely to
have on-site treatment with subsequent discharge to a stream than are
the other categories. Tomato processors and apple processors are two
notable exceptions, with wastes from more than 70% of the tomato products
production capacity going to municipal treatment systems and wastes from
more than 907o of apple products production capacity going to municipal
or on-land systems. One important difference between large corn and
potato processing plants and tomato processing plants is the length of
the processing period or "campaign." Citrus and potato processing
operations may run for 9 months of the year while tomato processing
operations run for only 2 to 3 months. (The shorter the season the less
likely a company will be to invest large sums of money for pollution
control equipment that will sit idle for 75% of the year.) Table 29
shows that more than two-thirds of the CPFV industry's wastewater is
treated in municipal treatment systems or by on-land treatment
It was previously mentioned that water reuse and recycling can
significantly reduce the volume of wastewater in the CPFV industry.
However, extensive water reuse or recycling in any food industry
does raise questions concerning public health. Public health
issues may arise if water that has been used to transport wastes
(equipment washing) or wash commodities is to be used in areas where
product contact may occur. While cascading water reuse from a process
demanding high water quality to a process demanding lower water quality
may be acceptable, complete reuse by recycling to all areas of the plant
may be limited because of pesticide buildup or the potential for patho-
genic organism transport. The current research now under way on water
reuse in the CPFV industry is described in Appendix G.
SEAFOOD PROCESSING INDUSTRY
The canned and preserved seafood industry is classified into the
following categories: farm-raised cat fish, conventional blue crab,
mechanized blue crab, Alaskan crab, dungeness and tanner crab, shrimp,
tuna, salmon, sardine, oyster, clam, etc.
65
-------
TABLE 29. PERCENTAGE OF PRODUCTION BY METHOD OF WASTEWATER
MANAGEMENT FOR VARIOUS PLANT CATEGORIES
Body of water
Plant after treatment
Category on- site
Apples (43)*
Dry beans (19)
Misc. berries (67)
Brined products (73)
Citrus (82)
Corn (51)
Dehydrated fruits
and vegetables (35)
Peeled fruit (43)
Pitted fruit (59)
Peeled, pitted or
juiced fruit (23)
Fruit juice (43)
Fruit and blanched
vegetables (55)
Pickles (78)
Frozen or
dehydrated potatoes (55)
Sauerkraut (23)
Tomatoes (219)
Blanched vegetables (329)
Miscellaneous (141)
Peeled vegetables
and tomatoes (43)
6%
8
11
1
69
40
_-
7
15
67
11
1
35
42
60
6
37
10
3
On- land irrigation;
Municipal evaporation or
system percolation lagoons
26%
29
70
26
7
8
75
93
7
30
77
90
26
24
40
78
16
50
69
68%
63
19
73
24
52
25
77
3
12
9
39
34
16'
49
40
28
Estimated number of plants falling into this plant category; total =1486.
Some systems with runoff.
Source: Reference 4-8.
66
-------
Until recently, little information was available on water use and
wastewater characteristics. Examples of unit wastewater loads for some
subcategories of seafood processing are shown in Table 30. Data in
Table 30 indicate that a tremendous variability, exists in the unit
water volume and in the BOD5 and suspended solids loads generated.
TABLE 30. UNIT WASTE LOADS FOR SUBCATEGORIES OF CANNED
AND PRESERVED SEAFOOD INDUSTRY
Water use
Commodity (liter/ton)
*
Crab
Shrimp
Clam (mechanically shucked)
Oyster (steam process)
Tuna
±
Salmon
±
Sardine
12,452
74,565
17,714
88,948
16,654
16,654
7,873
BOD5
(kg/ton)
7.5
83
17
55
12
51
8.2
Suspended
solids
(kg/ton)
3.0
85
5.5
14],
9.1
19
5
Assume that half is from conventional blue crab; the other half is
from mechanized blue crab, Alaskan crab, dungeness, and tanner crab,
^From EPA-Proposed Effluent Limitations Guidelines, 1972.
Source: Reference 4-9.
Table 31 shows the 1968 estimated quantities of raw materials pro-
cessed in the canned and preserved seafood industry. Combining infor-
mation from Tables 30 and 31 gives the estimates of wastewater loads
67
-------
from subcategories of seafood processing shown in Table 32. Clearly,
shrimp and tuna are two commodities with major water pollution problems.
TABLE 31. ESTIMATED QUANTITIES OF RAW MATERIALS
PROCESSED IN CANNED AND PRESERVED SEAFOOD INDUSTRY IN 1968
Commodity
Crab
Shrimp
Clam
Oyster
Tuna
Salmon
Sardine
Raw quantity
do3
30
120
90
20
520
120
26
processed
tons)
Source: Reference 4-10.
TABLE 32. ESTIMATED WASTEWATER LOADS
FROM SEAFOOD PROCESSING INDUSTRY
Commodity
Crab
Shrimp
Clam
Oyster
Tuna
Salmon
Sardine
Wastewater volume
(10 liters)
374
8,933
1,593
1,779
8,668
2,017
204
BOD
(io6 kg)
0.225
10
1.51
1.11
6.14
0.609
0.214
Suspended
solids
(io6 kg)
0.091
10.3
0.491
2.82
4.73
2.24
0.132
Source: SRI International.
68
-------
Treatment of wastewaters from seafood processing has been almost
nonexistent, because the processing plants are typically located on
the seacoast, many in remote areas. Since the passage of PL92-500
increasing concern about the condition of the environment has stimulated
activity in the application of existing waste treatment technologies to
the seafood industry. The tuna processing industry has done considerable
work on by-product recovery, and some other segments screen their wastes
for recovery of solids for use in meal and feeds. Further research is
needed on in-plant water use as well as end-of-pipe treatment.
SUGAR PROCESSING INDUSTRY
The sugar processing industry encompasses operations that convert
raw sugar cane to raw sugar, raw sugar to refined sugar, and raw sugar
beets to refined sugar. Table 33 shows the annual discharge of
wastewater volume, BOD,., and suspended solids from the sugar processing
industry in 1974.
TABLE 33. ANNUAL WASTEWATER DISCHARGE
OF SUGAR PROCESSING INDUSTRY, 1974
Total
sugar Cane Raw
Processing Beet sugar cane
Industry sugar refining sugar
Wastewater volume
BOD5
(106
Suspended
kg)
solids
(10
(106
9 liters)
kg)
341
68.2
455
132
4
4
.55
.55
18
2.
2.
.9
28
28
189
61.
448
4
Source: Reference 4-4.
As shown, raw cane sugar represents the major source of water pollution
in the sugar processing industry- (with 56% of the wastewater volume
907» of the BOD5 load, and 98.57= of the suspended solids). Beet sugar
generates a significant portion of wastewater volume, but a less signi-
ficant portion of BOD and suspended solids loads^ The water pollution
problem from cane sugar refining is small in the sugar processing indus-
try. The water pollution problems from raw cane sugar and beet sugar
are discussed below.
69
-------
The wastewater generated from raw cane sugar industries comes from
such operations as cane washing, floor washing, and condensing. Table 34
shows the sources, estimated volume, and BODc load of wastewaters from
processing steps in the cane sugar industry. The wastewater generated
by beet sugar industries comes from flume water, pulp screen water, pulp
press water, condenser, pulp silo drainage, and Steffen waste. In pulp
silo the extracted pulp ferments and produces a desirable type of wet
livestock feed. In the Steffen process, finely ground calcium oxide is
added under low temperature conditions to a dilute molasses solution to
precipitate a calcium saccharate. The Steffen wastes constitute one of
the most serious disposal problems in the sugar beet industry. (See
Table 35).
TABLE 34. REPRESENTATIVE CHARACTER AND VOLUME OF RAW CANE
SUGAR MANUFACTURING WASTES
(2,400 tons of cane daily capacity)
Flow rate
BOD
Kind of Waste
c average
(mg/liter)
Total daily
BOD load
(kg)
Cane wash water 1,000
Floor washings and
boiler blowdown 100
Excess condensate 50
*
Condenser water ,5,000
Totals 6,150
Average, per ton of
daily capacity ~
680
378
10
69
3,708
206
2.73
1,881
5,797.73
5.31
Assumes once-through operation.
Source: Reference 4-11.
The wastewater from the Steffen process is extremely high in BOD. Several
plants had to partly discontinue the Steffen operations because of the
waste disposal problem.
70
-------
About 65% of the sugar processing industry uses Lagoon treatment
for wastewater. About 30% of the industry uses the land disposal system,
and only 5% of the industry discharges to municipal sewage treatment
plants.
Lagoon systems are effective in removing all the floating and sus-
pended solids. Although BOD reduction on a percentage basis is good,
the final effluent BOD is often too high to allow compliance with
stream standards. Effluent of low BOD can be attained only by main-
taining long retention periods, which requires large land areas. There
is much interest in developing systems that require less land area.
TABLE 35. REPRESENTATIVE CHARACTER AND VOLUME OF BEET SUGAR
MANUFACTURING WASTES
Flow Suspended (kg/ton
(liter/ton BOD5 solids of beets
Waste
Flume water
Pulp screen water
Side-dump celltype diffuser
Continuous diffuser
Pulp press water
Pulp silo drainage
Lime cake slurry
Lime cake lagoon effluent
Barometric condenser water
Steffen waste
of beets)
9,841
5,375
1,514
681
795
341
284
7,570
9,992+
(mg/liter)
210
500
910
1,710
7,000
8,600
1,420
40
10,500
(mg/liter)
800-4,300
620
1,020
420
270
120,000
450
—
100-700
(sliced)
2.1
2.7
1.4
1.2
5.6
3.0
0.40
0.30
105
Water - transported pulp in lieu of mechanical conveyor.
Per ton of molasses processed on a 50% sucrose basis.
Source: Reference 4-11.
The sugar industry has been able to reduce effectively the waste-
water volume and BOD Load by improvements and advancements in the
following areas:
-------
(1) In-plant practices and equipment design
(2) Reuse of press water
(3) Enhanced recovery of sugar
(4) Reuse of flume water.
Suspended solids loads in wastewaters from sugar industries are the
highest among the food industries. More research is needed for improving
harvesting equipment to reduce amounts of soil, leaves, and stems, since
these materials require the use of excessive volumes of water to clean
the product. Improvements are also needed in the equipment used for dry
separation of the unwanted material from the sugar-bearing material.
MEAT INDUSTRIES (Red Meat and Poultry)
Red meats and poultry processing both require facilities for re-
ceiving; killing; removal of hide, hair, or feathers; eviscerating and
trimming; cooling; and packing. Further processing of the meat is more
extensive with swine and beef than with poultry.
The quantity and characteristics of the wastewater from this indus-
try are influenced by plant size, species slaughtered, amount of on-site
processing, extent of wastewater segregation, and recycling and reuse.
The reported ranges in water use, BOD, and suspended solids for waste-
waters, ffpm red meat packing and processing are quite large, as shown
below.
Flow, liter/head 575-685
BOD, mg/liter 320-5440
BOD, kg/1000 kg live weight 1.9-27.6
Suspended solids, mg/liter 240-7220
Suspended solids, kg/1000 kg live weight 1.2-53.8
Total volatile solids, kg/1000 kg live weight 3.1-56.4
Typical values for wastewater loads in kilograms per 1000 kilograms of live
weight killed are given in Table 36. As shown, the wastewater loads from
poultry dressing (kilograms per 1000 kilograms of live weight killed) are
similar to those of red meat packing and processing.
Table 37 shows the estimated water pollution potential from the
meat packing industry in 1967. Of the total raw waste load, red meat
packing and poultry dressing account for 80% and 15%, respectively. Of
the total wastewater volume, red meat packing and poultry dressing
account for 64% and 30%, respectively.
*
Source: Reference 4-12. 72
-------
Waste Load
Parameter
BOD
Suspended solids
Grease
Total Kjeldahl nitrogen
Phosphorus
Flow (liters)
Poultry
(kg/ 1000 kg LWK*)
10.0
7.8
1.7
1.2
0.4
3,785
Red meat
(kg/1000 kg LWK*)
12.1
8.7
6.0
1.0
0.2
1,806
"LWK - live weight killed.
Source: Reference 4-4.
TABLE 37. ESTIMATED WASTEWATER LOAD
AND VOLUME FOR MEAT INDUSTRY IN 1967
Raw wastewaters
SIC No.
2011
2013
2015
Industry
Meat packing
Meat processing
Poultry dressing
Material consumed
(io6 kg)
22,591
1,682
5,091
*
LWK
meat
LWK
Load
(IO6 BOD)
595
21
112
728
Flow
(IO6 liters)
196,820
17,790
92,733
307,343
*
LWK = live weight killed.
Source: Reference 4-4.
73
-------
Meat industry wastewaters contain carbon, nitrogen, and phosphorus
in proportions such that aerobic or anaerobic biological treatment is
readily accomplished without the addition of nutrients. The treatment
of wastewater may be handled in a municipal sewage treatment plant. In
many communities, the only pretreatments required prior to discharge of
wastewater to the public sewer, are treatment by screening to remove manure
solids and gravity separation or air flotation to reduce grease to 400
mg/liter. Between 507» and 70% of the total discharges from the meat
processing industry are to municipal sewer systems.
During the 1950s and early 1960s, the meat industry abandoned many
old packing plants in larger cities and built new slaughter or packing
plants in small communities near the source of animal production. In-
creased mechanization in processing meat products has tended to reduce
wastewater flow per unit of production. Location of new plants in small
communities has in many cases required the installation of secondary
treatment facilities on site, such as trickling filters, activated sludge,
anaerobic digesters, and anaerobic contact processes.
74
-------
REFERENCES
4-1 Office of Water Planning and Standards, National Water Q.,am-Y
Inventory, EPA-440/9-74-001, Volume 1, Washington, D.C., 1974.
4-2 U.S. Department of the Interior, The Cost of Clean Water,
Volume II, FWPCA, U.S. Government Printing Office, Washington
B.C., 1968. '
4-3 U.S. Department of the Interior, The Cost of Clean Water.
Volume III, FWPCA, U.S. Government Printing Office, Washington
D.C., 1968.
4-4 EPA Unpublished Research Planning Documents, 1974.
4-5 Mercer, W. A., "Canned Foods," in Industrial Wastewater Control.
Gurnham, C. F., ed., (Academic Press, New York, 1965).
4-6 Jones, J. L., and T. R. Parks, "Evaluation of Current and
Proposed Industrial Water Pollution Control Research Development
and Demonstration (RD&D) Program Under the Canned and Preserved
Fruits and Vegetables (CPFV) Categories," SRI International
Report, EPA Grant No. R-803239-01-0, 1975.
4-7 Environmental Associates, Inc., "Capabilities and Costs of
Water Pollution Abatement Technology for Canned Fruits and
Vegetables," PB-244-801, NTIS, June 1975.
4-8 Environmental Associates, Inc., "Capabilities and Cost of
Technology (Study area III), Canned and Preserved Fruits and
Vegetables Industry," February 1975.
4-9 "Development Document for Effluent Limitations Guidelines and
Source Performance Standards for the Fish Meal, Salmon, Bottom
Fish, Clam, Oyster, Sardine, Scallop, Herring, and Abalone Seg-
ment of the Canned and Preserved Fish and Seafood Processing
Industry Point Source Category," EPA PB256-240, September 1975.
4-10 Solid Waste Management in the Food Processing Industry.
PB-219 019 NTIS, 1973.
4-11 Jensen, L. T., "Sugar", *" Tnd.iatrrtal Wastewater Control.
Gurnham, C.F., ed. (Academic Press, New York, 1965).
4-12 Johnson, A. S., "Meat," in Industrial Wastewater Control.
Gurnham, C. F., ed. (Academic Press, New York, 1965).
75
-------
SECTION 6
PESTICIDES
Pesticides are widely used in agriculture and may be present in
wastewater streams, gas streams, or solid wastes (food scraps or sludges)
from food processing plants. To predict the fate of pesticides in the
various media, a mechanistic understanding of solubilization; volatiliza-
tion; adsorption; and chemical, thermal, or biological degradation of
pesticides is needed. A predictive model such as this is far beyond the
scope of this study. For this study it will only be possible to estimate
the maximum potential concentrations of pesticides in the wastewaters,
gases, and solid wastes from several selected commodity categories.
There are a wide variety of pesticides for agricultural use. Accord-
ing to their purpose, pesticides can be categorized into insecticides,
herbicides, and fungicides. For this study of the maximum potential con-
centrations of pesticides, only insecticides have been considered.
Two commodities, citrus and apple, are considered in this analysis,
and concentrations of pesticides in wastewater and solids are estimated.
(See Appendix D for a discussion of pesticide releases to the atmosphere
from thermal processing.) Three typical chlorinated hydrocarbons (chlor-
dane, lindane, and toxaphene) and three organophosphorous compounds (EPN,
malathion, and parathion) have been selected for estimating the maximum
potential releases. Table 38 shows the maximum allowable concentrations
of these pesticides in raw citrus and apple. ~TThese maximum allowable
concentrations will be used to estimate the maximum concentrations in
wastewater and solid wastes.
Table 39 presents the wastewater and solid waste quantities from citrus
and apple processing industries. The information in Tables 38 and 39 can
be used to estimate the maximum potential concentration of pesticides.
To estimate the maximum concentration of pesticides in wastewater, it is
assumed that all the pesticides in the raw crop are transferred to the
wastewater. The following is an example of an estimate of the concentra-
tion of chlordane in wastewater from the citrus industry:
From Table 38: Maximum allowable concentration of chlordane in
raw citrus = 0.3 ppm
From Table 39: liters of wastewater = 9084 liters wastewater
ton of raw citrus ton of citrus
processed
76
-------
TABLE 38. MAXIMUM ALLOWABLE CONCENTRATION OF SELECTED
INSECTICIDES INRAW CITRUS AND APPLE
Concentration
(ppm)
Insecticide Citrus Apple
Chlorinated hydrocarbons
Chlordane Q.3 03
Lindane __ i
Toxaphene 7 -j
Organophosphorous
EPN 3 3
Malathion 8 8
Parathion 1 i
Source: Reference 5-1.
TABLE 39- QUANTITY OF WASTEWATER AND SOLID WASTES FROM
SELECTED FOOD INDUSTRIES
Food industry
Citrus
Apple
Wastewater
(liters wastewater/
ton of raw crop)
9,084 *
2,650 *
Solid wastes
(ton of residues/
ton of raw crop)
0.395f
0.276*
From Reference 5-2.
From Reference 5-3, 3,080 tons of residuals is generated from
7,800 tons of raw citrus processed. Therefore,
3.080 tons of residuals = 0.395 ton of residuals/ton of citrus.
7,800 tons of raw citrus
*From Reference 5-3, 290 tons of residuals is generated from
1,050 tons of raw apple processed. Therefore,
290 tons of residuals = 0.276 ton of residuals/ton of apple.
1,050 tons of raw apple
77
-------
Therefore,
the maximum potential concentration of chlordane in waste-
water from citrus industry
chlordane [ /2000 lb\ /454 g\/
citrus / I ton ) ll Ibyl
ton of citrus \
zAOO gal wastewater/
J = 30 (J,g chlordane/liter of waster, or
To estimate the maximum concentration of pesticides in solid wastes,
it is assumed that all the pesticides in the raw crop are present in the
solid wastes (i.e., food scrap). The following is an example of an
estimate of the concentration of chlordane in solid wastes from the
citrus industry:
From Table 33:
Maximum allowable concentration of chlordane
in raw citrus = 0.3 ppm.
From Table 34:
ton of residuals _ 0.395 ton of residuals
ton of raw crop ton of raw crop
Therefore,
the maximum potential concentration of chlordane in solid
wastes from citrus industry
0.3 M-g chlordane ton of citrus
g of citrus 0.395 ton of citrus residuals
=0.76 ppm.
78
-------
Table 40 presents the maximum potential concentration for selected
insecticides in wastewaters from citrus and apple industries. The maxim
potential concentrations are much higher than EPA-proposed water quality
criteria for pesticides. However, the predictions in Table 40 did not
take into account the degradation of pesticides. Generally, organophos-
phorous compounds are more degradable than chlorinated hydrocarbons.
TABLE 40. MAXIMUM POTENTIAL CONCENTRATION FOR SELECTED
INSECTICIDES IN WASTEWATERS FROM FOOD INDUSTRIES*
(ppb)
EPA1"
Food Industries Proposed
Insecticides Citrus Apple Criteria
Chlorinated Hydrocarbons
Chlordane
Lindane
Toxaphene
Organophosphorous
EPN
Malathion
Parathion
30
—
700
300
800
100
103
343
2,399
1,028
2,742
343
0.04
0.02
0.01
0.06
0.008
0.001
Assuming that all the pesticides on the crops enter the waste-
water.
From Reference 5-4.
Source: SRI International; EPA,
Table 41 gives the half-lives of three organophosphorousinsecticides. As
shown, the half-lives of EPN, malathion, and parathion are all less than
3 days. It is believed that the concentrations of organophosphorous in-
secticides will be below the EPA criteria if the time between pesticide
application and harvesting is long enough for degradation. Caution should
be used on chlorinated hydrocarbons since they are highly persistent
(long-lived) and mobile.
79
-------
TABLE 41. HALF-LIVES FOR SELECTED
ORGANOPHOSPHOROUS INSECTICIDES
Insecticide
EPN
Malathion
Parathion
Half-life
(days)
3 (Apples)
3 (Apples)
3 (Citrus)
2 (Apples)
Source: Based on U.S. government data.
Table 42 presents the maximum potential concentration for selected
insecticides in solid wastes from citrus and apple industries. If the
solid wastes are used for animal feed, the pesticides will enter into
the food chain:
solid wastes
(containing pesticides)
-» cattle -* human
TABLE 42. MAXIMUM POTENTIAL CONCENTRATION
FOR SELECTED INSECTICIDES IN SOLID WASTES
FROM FOOD INDUSTRIES*
Insecticides
Concentration
(ppm)
Citrus Apple
Chlorinated Hydrocarbons
Chlordane
Lindane
Toxaphene
Organ ophosphorous
EPN
Malathion
Parathion
0.76
--
18
7.6
20
2.5
1.1
3.6
25
11
29
3.6
Assume that all the pesticides on the crops remain
in the solid wastes (i.e., food scraps).
Source: Based on U.S. government data.
80
-------
Judging by the maximum concentrations of insecticides in solid wastes
shown in Table 42, caution should be exercised in using solid wastes for
animal feed, especially for those containing chlorinated hydrocarbons.
It should be emphasized that Tables 40 and 42 may overestimate the
maximum concentrations of pesticides in wastewaters and solid wastes
because of the assumptions made in the estimation.
L. L. Wilson, et al., noted in feeding experiments with apple wastes
that the fat of waste-fed cattle contained significantly more total DDT
residue than did fat of cattle not fed waste. However, they concluded
that low-to-moderate levels of apple waste may be used in cattle finishing
rations. *~^
81
-------
REFERENCES
5-1 Code of Federal Regulations, Title 40, Protection of Environment,
part 180, U.S. Government Printing Office, Washington, D.C. 1976.
5-2 EPA, "Proposed Industrial Point Source Technology Achievement
Plan to Meet the Requirement of PL 92-500." Unpublished EPA
Planning Document, 1974.
5-3 Katsuyama, A. M., N. A. Olson, R. L. Quirk, and W. A. Mercer,
"Solid Waste Management in the Food Processing Industry," PB-219019,
NTIS, 1973.
5-4 EPA, "Comparison of NTAC, NAS, and proposed EPA Numerical Criteria
for Water Quality", 1974.
5-5 Wilson, L. L.,et al., "Accumulation of Certain Pesticides in
Adipose Tissues and Performance of Angus, Hereford, and Holstein
Steers Fed Apple Processing Wastes," Pennsylvania State University,
Agricultural Experiment Station Publication No. 3668, 1970.
82
-------
Appendix A
SULFUR OXIDES (SO*) EMISSIONS
BACKGROUND
Fruit drying is an important source of SOx emissions in the food
industry. About 90% of the dried fruit output is produced in California.
Some dried apples are also produced in the states of Washington and
Oregon, and some fruit drying is practiced in Arizona, Idaho, New York,
and Virginia.
Fruits can be artificially dried by several methods, such as kiln,
cabinet, tunnel and continuous belt, or conveyor drying. For certain
specialty products (such as snacks, military rations, dry mixes), vacuum
drying and freeze drying are also used. Sulfur dioxide is emitted during
the sulfuring operation, which may precede or occur simultaneously with
the drying and/or dehydrating.
APPLE DRYING
Apples are dried either immediately after harvesting or after being
stored in cold and/or controlled atmosphere until a convenient
processing time. Only artificial driers are used by the commercial apple
drying industry. Kiln or tunnel dryers are commonly used to produce
dried apples. Dehydrated (low moisture) apples are processed in forced
air dryers such as the continuous belt dryer, using kiln-dried fruit as
raw material. Some apples are vacuum-dried for snack or other specialty
product applications.
The process involves sizing, peeling, coring, and slicing the fruit
to pieces 0.95-1.27 centimeters in thickness. The fruit is dipped into
sodium bisulfite solution and then dried in a kiln or tunnel dryer to
approximately 16 to 26% moisture. During drying, the fruit slices are
exposed to the fumes of burning sulfur. Drying in the kiln requires
14 to 18 hours.
If the product is processed to a low-moisture state (under 5% mois-
ture), the dried slices are cut to the desired size (0.64 centimeters and
0.95 centimeters dice, etc.) Frequently the fruit pieces are "instantized"
by compression and/or perforation and dried to the final moisture content
83
-------
in a continuous belt air dryer or in a vacuum dryer. An estimated 50%
of the sulfur dioxide applied in the kiln drying process is lost during
the secondary drying due to volatilization.
APRICOT AND FREESTONE PEACH DRYING
Apricots and freestone peaches are usually sun dried. Apricots for
drying are hand-picked at maturity, placed into lug boxes, and transported
to a cutting shed. The fruit is halved, the pit is removed, and the
fruit is placed cup up on a flat, precleaned wooden tray. The filled
trays are exposed to sulfur dioxide fumes (burning elemental sulfur) for
about 12 hours. This prevents browning of the fruit during the drying
process. After sulfuring, the trays are transferred to a field where
they are placed on the ground, exposing the fruit to full sun. Apricots
are allowed to dry in this manner for 1 day, after which time the individual
trays are transferred to a shady area and stacked 0.9-1.22 meters high
and allowed to dry in the "stack" for approximately 1 additional week.
Similarly, the freestone peaches, after sulfuring, are placed in
full sun for 2 to 3 days or longer, depending on the weather conditions,
at which time they are transferred to shady "stack" storage, dried for
several additional weeks, removed from the trays, transferred to boxes
or bins, and delivered to the packing plant.
Dehydrated (low moisture) apricots and peaches are processed from
sun-dried (evaporated) fruit to a limited extent.
PEAR DRYING
Pears that are to be dried are hand-picked when ripe and transported
to cutting sheds where they are cored and halved by hand. They are then
placed cup up on wooden racks and stored overnight in sulfur houses,
where they are exposed to burning sulfur to prevent browning. The pear
halves are removed from the sulfur house and dried in the sun for 4 to
8 days and then transferred to stacked storage for an additional 2 to
3 weeks.
Once dried, the fruit is delivered to the packing plant, where it
is processed usually to fill orders. The dried fruit from the field
may sometimes be stored as long as several years before being repacked.
Typically, the fruit is graded for size and appearance, hand-inspected
to remove undesirable pieces (e.g., those with off color, slabs, insect
damage) and then sent through a recleaning operation. This is normally
a high-speed, reel-type cleaner fitted with brushes, which both softens
and loosens any dirt, wood, or insect particles that may have become
84
-------
attached to the fruit during the field drying process. Partial rehydra-
tion occurs, and hence the fruit must be resulfured and redried prior
to adding preservatives (yeast and mold inhibitors) and final packing.
QUANTIFICATION OF THE SOx PROBLEM
In 1972 the reported production of dried and dehydrated fruits was
661 billion kilograms. Sulfured products were included in the "apples"
category and "other fruits" category, representing 11.9 and 24.2 million
kilograms, respectively. Table A-l presents estimates for hourly SO-
emissions from sulfuring of apricots and apples respectively. The bases
for the estimation of the emission factors used in Table A-l are presented
in Figures A-l and A-2.
In Table A-2 the calculated emissions from sulfuring of apples and
apricots are compared to four major industrial S02 sources.
Because of the small number of fruit sulfuring plants and the sea-
sonal nature of the emissions, sulfuring of fruit is not a significant
source of SOo relative to other point sources. These sulfuring plants
may, however, create very localized air quality problems because of the
ground level release of S02«
85
-------
TABLE A-l. ESTIMATED HOURLY EMISSIONS OF S02 FROM SULFURING
OF APPLES AND APRICOTS
Calculated emission factors
(11
Apples |
[dQ,
kg 30,,/ton of apple processed
L
kg S02/ton of dried apple product
. [ 7 kg S0£/ton of apricot processed
I 52 kg S02/ton of dried apricot
Apples
17,000 tons dried product/yr (maximum)
13,000 tons dried product produced in 1972
~ 10 plants
4 months of operation (75% of production)
/17.OOP tons (0.75)\/ 1 month \ / 1 week \ / 1 day \ = 7.
\ 4 months /\ 4.2 weeks / \6 days / \ 16 hrs /
9 tons dried
apples/hr
/7.9 tons dried apples \ / 60 kg SO? \ /10 plants = 47.4 kg S02/hr
V hr /\ton dried apples// plant
Apricots
6000 tons dried product/yr
~ 10 plants
2 weeks of operation, 6 days/week, 2 shifts/day
/6000 tons W1 week \ / 1 day \ = 31.25 tons/hr
\ 2 weeks / \6 days ) \ 16 hrs /
(31.25 tons dried product/hr)(52.3 ke SOo/ton dried product) - 163 kg S02/hr
10 plants plant
Source; SRI Internationalt
86
-------
oo
1 ton of apple
at 85% moisture
(or, 773 kg H2O)
10°C ambient
at 50% RH
0.004 kg H2O/kg dry air
773 kg H2O
11.8 kg SO2
74°C
0.004 kg H20/kg dry air
«wb
Vent Air, tyvb = 27°C
at 60%RH, 0.02 kg H2O/kg dry air
739 kg H2O, 11.4 kg SO2
DRYER
AT 74°C
1 70 kg of apple
at 20% moisture (or, 34 kg
H2O) and 2500 ppm SO2
(or, 0.43 kg SO2)
Solid Balance
909 kg x 0.15 = X kg x 0.80
X = 170 kg
where X is the weight of product
SO2 Balance
SO2 into dryer 909 x 0.85 x 0.02 x 0.77 = 11.8 kg
-SO2 in product 170 x 2500 x 10"6 = 0.43 kg
SO2 vent
11.4 kg
H2O Balance
H2O into dryer 909 x 0.85 = 773 kg
-H2O in product 170 x 0.2 = 34 kg
H2O evaporated
739 kg
SOURCE: SRI International.
Figure A-l. Flow sheet and material balance for apple sulfiting and drying.
-------
so.
so,.
1 ton of apricot
at 90% moisture
3.6 kg sulfur
and air
Sulfuring
Apricot
< 90%
Sun Drying
120 kg apricot
at 24% moisture
and 2500 ppm (or, 1250 ppm) S
oo
oo
Solid Balance
909 kg x 0.10 = Xkg x 0.76
X = 120 kg
where X is the weight of product
Sulfur Balance
Case I: 2500 ppm S in product
SO input 8x2
-6
in product 263 x 2500 x 10 x 2
7.3 kg
0.59 kg
SO vent
6.71 kg
SOURCE: SRI International.
Case II: 1250 ppm S in product
8x2
SO input
- SO in product
-6
263 x 1250 x 10 x 2
7.3 kg
0.32 kg
SO vent
6.98 kg
Figure A-2. Flow sheet and material balance for apricot sulfuring and drying.
-------
TABLE A-2. COMPARISON OF S02 SOURCES
Type of plant Plant capacity kg S0?/hr
*
Power plant 500 MW 1718
Oil refinery 100,000 bbl/day 511 ~ 1174
Sulfuric acid plant 500 ton/day 38
Copper smelter* 300 ton/day 2614
Sulfuring of apple 1275 ton/4 months 580
Sulfuring of apricot 600 ton/2 weeks 180
*$£ f\
Meeting New Source Performance Standards of 0.55 kg SO /10 Btu
for a power plant capacity factor of 0.7.
Range of reported values; low value for S.F. Bay Area; high value
from EPA emission factors.
Meeting NSPS of 1.8 kg SO /10 Btu H SO
fi
*Assuming 2.30 ton S02/ton copper, and 90% removal of S02-
Sources: EPA; SRI International.
89
-------
Appendix B
POLYNUCLEAR AROMATIC HYDROCARBONS (PAH)
BACKGROUND INFORMATION ON PAH
Polynuclear aromatic hydrocarbons are widely distributed in the envi-
ronment. They are found in living animal and plant tissue, sediments,
soils, air, and surface waters. Most PAH probably arise as pyrolysis
products formed during combustion or heating of fossil fuels and of most
natural products. The compounds may be natural products of animal and
vegetable metabolisms, and are probably released from exposed fossil fuel
deposits by erosion. PAH are essentially not soluble in water and have
low vapor pressures, so that the major environmental transport mode is as
particulate in air or water. However, comparison of PAH levels in plant
and animal tissue suggests that concentration effects are not large des-
pite large partition coefficients reflecting high solubility in fatty
tissues. Present methods of analysis for estimating airborne concen-
trations of PAH may seriously underestimate the concentrations of some
relatively volatile PAH such as pyrene, anthracene, and benzo(a)anthra-
cene.
In water and soil, PAH occur almost completely in the adsorbed state
on minerals or organic particulate. In the air, some PAH may be found in
the vapor phase although most must be adsorbed on particulate matter.
Only a few studies have been conducted to assess the biological
effects of PAH, other than those that relate to carcinogenicity, muta-
genicity, or teratogenicity. These studies indicate that these compounds
can be acutely toxic to different organisms throughout the phylogenetic
scale and can produce a variety of sublethal effects. These effects,
however, do not appear related in terms of degree or type to the number
of rings, number of ring substituents, or their position, or the arrange-
ment of the rings within the molecule,
Athough many PAH compounds have been tested for carcinogenicity,
little information is available on the acute and subacute toxicity of
these compounds. Most studies concerned with effects of PAH compounds
on enzyme systems and other biochemical factors have attempted to eluci-
date the mechanism of carcinogenic action.
90
-------
PAH are formed under high-temperature pyrolysls of organic matter
The amount of benzo(a)pyrene (BaP) formed, for example, depends on how'
reducing the combustion atmosphere is. With increasing air-to-fuel
ratios, BaP decreases in concentration. PAH formation also seems to be
associated with higher plants that contain more complex phenolic com-
pounds (e.g., lignin), but other types of organics can also produce PAH B'6
Pyrolysis of lignins and terpines during forest fires has been identified
as a likely source of PAH in relatively high yields.
Listed below are typical values for concentration of PAH on parti-
culate matter from open burning that could be comparable to values for a
smokehouse.
Mg/kg of particulate matter
PAH Municipal Commercial Open
Benz(a)anthracene 0.09-0.26 5-210 25-560
Benzo(a)pyrene 0.02-3.3 58-180 11-1100
PROBABLE SOURCES OF PAH IN THE FOOD INDUSTRIES
Of the more than 1300 meat processors in the United States, the vast
majority use smoking for flavoring. In 1970, 3 million tons of meat pro-
ducts and approximately 17,000 tons of fish were smoked.
Within the past few years, technology has made possible the manu-
facture of an artificial liquid smoke flavoring product containing
chemical components simulating the color, aroma, and flavor character-
istics of smoke. When used in meat or poultry products, their names are
modified with the term "Artificial Smoke Flavor Added."
In addition to the synthesized liquid, a natural liquid smoke pro-
duct is also produced. It is prepared by burning wood and trapping and
condensing the smoke into a liquid. The liquid is then filtered to re-
move many of the undesirable components, such as tars and solid particles.
Meat and poultry products containing such a substance are required to be
labeled with the terms "Smoke Flavored" or "Smoke Flavoring Added."
According to Mr. L. G. Broidy of the Western Regional Office MID, per-
haps as much as 50% of the smoke processed meat is prepared with natural
liquid smoke, and this proportion is increasing rapidly.
91
-------
The application of liquid smoke has at least two advantages: (1)
sanitation of the smoking facilities, due to the absence of many tars
from the liquid smoke; (2) environmental considerations, since there is
less evacuation of pollutants into the atmosphere from liquid smoke than
with the natural wood burning process. This latter advantage has gained
particular attention in municipalities having strict ordinances on air
pollution.B-3
Although PAH have not been identified as emissions from smokehouses,
literature mentions the relatively high PAH content of smoked fish and
meats.B~4 The source of these PAH in the meat is probably the smoke,
because the temperature of the meat itself would not be high enough to
form these compounds.
The smoking of meat gives the finished product a characteristic and
desirable flavor, some protection against oxidation, and an inhibiting
effect on bacterial growth. Smoke is most commonly generated from hard-
wood sawdust or small-size wood chips outside the oven and is carried to
the oven and introduced through duct work. A small stream of water is
used to quench the burned hardwood sawdust before dumping the sawdust to
waste. The most common operation is to overflow the water from this
quenching section and to waste the water into the sewer. One plant
slurried the char from the smoke generator, piped it to a static screen
for separation of the char from the water, and then wasted the water.
In total quantity, the waste load and wastewater generated in this
cleanup is not particularly significant. However, there is a noticeable
coloration of the wastewater during cleanup and, depending on the extent
of the use of caustic, an increase in the pH of the wastewater.
QUANTIFICATION OF THE PAH PROBLEM IN THE FOOD INDUSTRIES
Smokehouse Exhaust Products
Smokehouse exhaust products include organic gases, liquids, and
solids, all of which must be considered air contaminants. Many of the
gaseous compounds are irritating to the eyes and reasonably odorous. A
large portion of the particulates is in the submicrometer size range
where light scattering is maximum. These air contaminants are attribu-
table to smoke, that is, to smoke generated from hardwood, rather than
from the cooked product itself.B~^
92
-------
Exhaust gases from both atmospheric and recirculating smokehouses
can be periodically expected to exceed 40% opacity, the maximum allowable
under many local air pollution control regulations. With the possible
exception of public nuisance, smokehouse exhaust gases are not likely to
exceed other local air quality standards.B~^
Hooding and Ventilation Requirements
Atmospheric smokehouses are designed with exhaust volumes of about
2.74 cubic meters per square meter of floor area. Somewhat higher volumes
are used with atmospheric houses of two or more stories.B~^
Recirculation smokehouses have a considerably wider range of exhaust
rates. During smoking and cooking cycles, volumes of 0.914 to 3.66 cubic
meter per square meter of floor area are exhausted.
The highest reported values for particulate matter in smokehouse
exhaust are about 0.535 grams per normal cubic meter, with the emission
factors varying from 0.136 to 0.068 kg/ton of meat for the uncontrolled
and controlled cases, respectively. '
If one assumes a PAH concentration of 1000 ppm on the particulate
matter and 3 x 10 tons of meat smoked per year (assuming no controls),
then the maximum PAH release to the atmosphere would be as follows:
{ 3.0 x 106 tons meat\ (0.136 kg particulatej { 455 kg PAH j „
I yr } \ ton / \455 x 103 kg particulate/
0.455 kg PAH
yr
Approximately 9.09 kilograms of wood is burned per ton of meat
smoked.B'6 By assuming a char production of 0.227 kg/kg wood and a
concentration of PAH of 1000 ppm on the char, the possible quantity of
PAH that is washed out of the smokehouses can be estimated;
/ 3.0 x 106 tons meaA/ 9.09 kg wood \ /0.227 kg charV 455 kg PAH
1 _ n tonmeat^ kg wood/\455 x 10J kg
13.600 kg PAH
93
-------
As shown in Table B-l, the total estimated amount of PAH emissions
(listed as PCM for polycyclic organic matter) is 4.8 million tons. The
estimated releases from smokehouses are insignificant compared to other
sources.
TABLE B-l. HAZARDOUS POLLUTANT SOURCES
Amount of POM
Source
Iron and steel
Metallurgical coke
Asphalt industry
Paving material preparation
Roofing material preparation
Petroleum refining
Incineration
Industrial
Domestic
Auto body
Conical burner
Open burning
Agricultural burning
Natural fires, forest
Natural fires, urban
Municipal
Coal refuse
Power plant boilers
Pulverized coal
Stoker coal
Cyclone coal
All oil
All gas
Industrial boilers
Pulverized coal
Stoker coal
Cyclone coal
All oil
All gas
Residential /commercial
Coal
Oil
Gas
Total
Tons/year
43,380
2,800
23,230
2,170
2,228
730
14,602
212,211
526,843
2,161,142
1,433,712
6,060
682
193,500
8,980
1,032
310
7,675
6,151
1,896
6,635
948
10,001
20,220
66,796
33,105
10.065
4,797,104
%
0.90
0.06
0.48
0.05
0.05
0.02
0.30
4.42
10.98
45.05
29.89
0.13
0.01
4.03
0.19
0.02
0.01
0.16
0.13
0.04
0.14
0.02
0.21
0.42
1.39
0.69
0.21
100.00
7t
PCM is polycyclic organic matter.
Source: Reference B-7.
94
-------
REFERENCES
B-l Radding, S. B., et al., The Environmental Fate of Selected Poly-
nuclear Aromatic Hydrocarbons, EPA 560/2-75-009, February 1976.
B-2 Personal communication, Mr. L. G. Broidy of the Western Regional
Office MID, USDA (September 1976).
B-3 Federal Register, 41, 85 (April 30, 1976).
B-4 Development Document for Proposed Effluent Limitations Guidelines
and New Source Performance Standards for the Processor Segment of
the Meat Products Point Source Category, EPA 440/1-74/031 August
1974,
B-5 Air Pollution Engineering Manual, John A. Danielson, ed., U.S.
Dept. of Health, Education and Welfare 1967.
B-6 Borneff, J., F. Solonka, H. Kunte, and A. Maximos, Experimental
Studies on the Formation of Polycyclic Aromatic Hydrocarbons in
Plants, Environmental Research 2: 22-29 (1968).
B-7 Goldberg, A. J., A. Survey of Emissions and Controls for Hazardous
and Other Pollutants, EPA, PB223568, February 1973.
95
-------
Appendix C
CHLORINATED HYDROCARBONS
BACKGROUND
Chlorinated hydrocarbons have been used for hops extraction, extrac-
tion of caffeine from coffee, extraction of cocoa butter, extraction of
soya beans, and in the peeling of some fruits and vegetables. No data
are available on the actual past usage of trichloroethylene (TCE), but
it has been estimated that about 10% of the 1974 production of 157 million
kilograms went to miscellaneous or nonmetal cleaning uses. The majority
(two-thirds) of this miscellaneous use was probably in the production of
polyvinl chloride where TCE is used as a chain terminator. Other non-
food industry uses are as a solvent for textile cleaning and dyeing and
C* — 1
as a raw material for fungicide production. Available data show that
the probable consumption of TCE by the food industries was well below
4.55 million kilograms in 1974. Coffee processing probably represented
the largest single use.
COFFEE PROCESSING
Because of the "memorandum of alert" issued by the National Cancer
Institute in April 1975 concerning potential carcinogenic hazards of TCE,
all coffee extraction in the United States is now carried out with
methylene chloride and this solvent will probably be substituted for
almost all other chlorinated hydrocarbon uses in the food processing
industries.
The estimated volume of discharge in 1975 of TCE from extraction of
coffee from one plant was estimated at an average concentration of less
than 150 mg/liter in an average raw wastewater flow of 100,000 gal/day
(378.5 m3/day), or about 55 kg/day,
C-3
A representative of Hills Bros. Coffee reported that producers of
decaffeinated coffee are now considering an aqueous extraction process.
The reason is that many people consider the current substitute for TCE,
methylene chloride, also to be highly suspect as a chemical carcinogen.
In the new process, "saturated water" is prepared by extracting the green
coffee beans. This saturated solution can be recycled and will remove
96
-------
essentially only caffeine. The process is used in Germany and may be
adopted here.
General Foods and Nestle are currently the two largest decaffeinated
coffee producers. Most small coffee companies usually contract out the
decaffeination production because of the high investment cost for the
production units.
HOPS EXTRACTION
From contacts with representatives of Dow Chemical0"4 and the Joseph
Schlitz Brewing Co.,c"5 it was learned that Pabst and Schlitz have defi-
nitely discontinued the use of hop extracts. It is also believed that
all other brewers have discontinued this practice.0"5 The impetus for
this move was an FDA ruling requiring that labels give information that
the beer contains hop extracts (and any other material used for the
extraction that may remain).
OIL SEED EXTRACTION
Dow Chemical Company is now working on a process to use methylene
chloride for oil seed processing. At present, the industry (without
exception, according to Dow) uses hexane. The estimated loss of hexane
is approximately 1 gallon per ton of seed processes, and there is
apparently no real incentive to change the process solvent. Dow does
not anticipate any rapid changes in the future by this industry in use
of chlorinated solvents.
FRUITS AND VEGETABLES PEELING
Although a great deal of research and development work has been
done on using chlorinated solvents for peeling, no processes have
reached the commercial stages. The main problem with the process for
commodities such as tomatoes has been migration of the solvent into the
interior through the stem. According to representatives of the National
Canners Association Laboratory in Berkeley, no plants are currently ^
using chlorinated solvents for peeling, nor do they intend to do so.
MISCELLANEOUS USES
Trichloroethylene was used as a solvent for extraction of annatto
food coloring from botanical material. This food coloring is widely used
97
-------
in the dairy industry. It is not known if methylene chloride is now
used for this extraction.
Methylene chloride is a component of inks used for marking fruits
and vegetables.
Neither of these uses should represent a significant source of
chlorinated solvents relative to other industrial sources.
98
-------
REFERENCES
C-l SRI International Chemical Economics Handbook.
C-2 Camisa, A. G., "Analysis and Characteristics of Trichloroethylene
Wastes," JWPCF 47^ (5): 1021-31 (1975).
99
-------
Appendix D
PESTICIDE EMISSIONS FROM ROASTING OPERATIONS
PEANUT ROASTING
Peanuts are roasted for making peanut butter and salted peanuts.
In the roasting process, the moisture content of peanuts is reduced from
a normal of about 5 to 0.5%. The peanuts are heated to 160°C and
held at this temperature for 40 to 60 minutes. Hot air is blown through
the roaster to carry moisture away. At 160°C, pesticides in the peanuts
may be vaporized and emitted with the hot air or thermally decomposed.
To assess the pesticide problem produced by peanut roasting, the
types and quantities of pesticides applied to the peanuts in the field
must be evaluated. Table D-l lists the types of pesticides used and
their tolerance level. The tolerance level is considered as the upper
limit when the maximum quantity of pesticide is applied to the peanut
field.
The maximum emission of pesticides from the roasting process can be
estimated from the material balance for a roasting unit. Figure D-l
shows the process flow diagram and calculations. Sevin and parathion
have been selected as representative of two common pesticides. In
Table D-2, the calculated pesticide emissions from peanut roasting are
compared with the occupational hazard level for ambient air in the work
place.
In the roaster offgas, the calculated concentrations of parathion
and sevin both exceed the levels permitted in air by the OSHA occupational
standards. However, these concentrations will be much reduced by dilu-
tion with air as the offgas is discharged to the atmosphere. If the
offgas should be incinerated to destroy odors and other volatiles, the
pesticides should also be destroyed. The pesticides might also be partly
removed by scrubbing the gas with either water or a chemical solution.
COFFEE ROASTING
Unlike peanuts, coffee is imported from South American and the con-
centration of pesticide in coffee may thus be low. According to Sevitz
(1976), most coffee plants are equipped with afterburners for odor con-
trol. Pesticides are believed to be decomposed to water and carbon dio-
xide in afterburners.
100
-------
TABLE D-l. TYPE AND TOLERANCE LEVEL
OF PESTICIDES APPLIED TO PEANUTS
Type of pesticide
Insecticide
Sevin
Methomyl
Toxaphene
Disyston
Azodrin
Thimet
Furadan
Dasanit
Parathion
Diazinon
Mocap
Herbicide
Balan
Vernam
Lasso
Treflan
Butyrac
Dinoseb
Naptalam
Fungicide
Benlate
Chlorothalonil
DBCP
Terraclor
Mancozeb
Du-Ter
Pesticide ranking*
(% application)
15%
12
7
6
6
6
5
2
2
2
1
26
22
11
10
8
8
4
40
30
4
2
1
1
Tolerance
level
(ppm)
5
0.1
7
0.75
0.05
0.1
0.05
1.0
0.75
0.02
0.05
0.1
0.05
0.05
0.02
0.1
0.1
0.2
0.3
0.5
1.0
0.05
t.
Pesticide Ranking, percent of total acreage treated with
pesticide type (insecticide, herbicide, etc.).
From EPA Compendium of Registered Products. Tolerance from
pesticides is defined as the minute trace permitted to be
present in or on raw agricultural commodities (from Miller
Pesticide Residue Amendment to Federal Food, Drug, and Cosmetic
Act, 1954).
Source: EPA; SRI International.
-------
4.5 gms Sevin
0.91 gms parathion
909 kg peanut
5% moisutre
10°C Air,
50% RH
0.004 kg H2O/kg dry air
4.5 gms Sevin
Vent Air 0.91 gms parathion
RH 60%, 0.05 kg H2O/kg dry air
ROASTER
@ 160°C
868 kg of peanut
0.5% moisture
H20 Balance
H_O into roaster
-H20 in product
Air Required
909 x 0.05 - 45 kg 40 6 kg H 0
868 x O.OOb «• 4.36 kg " y v J
(0.05 - 0.004) ka H.,O/kg drv air - et at * in2.,,3
H2O evaporated
40.6 kg
Solid Balance
909 kg x 0.95 = x kg x 0.995
x = 868 kg
where x is the weight of roasted peanut,
Parathion concentration
0.002 Ib 0.002 x 454 x 103 mg
2.45 x 104 scf 2.45 x 104 x 0.028 m3
= 1.32 mg/m3
SOURCE: SRI International.
Sevin Concentration
0.01 Ib sevin = 0.01 x 454 x 103 mg
2.45 x 104 scf ~ 2.45 x 104 x 0.028 m3
= 6.62 mg/m3
Figure D-l Flow sheet and material balance for peanut roasting.
102
-------
TABLE D-2. COMPARISON OF PESTICIDE EMISSION FROM
PEANUT ROASTING WITH OCCUPATIONAL STANDARD
Pesticides
Sevin
Parathion
Emission
(mg/m3)
6.62
1.32
Occupational
standard
(mg/m3)0'2
5
0.1
Source: OSHA; SRI International.
103
-------
REFERENCES
D-l Woodroof, Jasper G., Peanuts: Production, Processing, Products,
Avi Publishing Co., Westport, Connecticut, 1966.
D-2 "Occupational Safety and Health Standards, Subpart Z - Toxic
and Hazardous Substances," Occupational Safety and Health Reporter,
The Bureau of National Affairs, Inc., 1976.
104
-------
Appendix E
SOURCES OF PHENOLIC COMPOUNDS IN CITRUS PROCESSING WASTEWATERS
E-l
Ismail and Wardowski have reported on sources of phenolic-type
compounds from citrus fruit processing operations. They found that plants
using sodium o-phenylphenate (SOPP) in their detergent formulations ex-
hibited high levels of phenolics, as shown in Table E-l. The main source
of the phenolics was the fungicide SOPP, but a dye Citrus Red No. 2 and
the fruit itself were major sources.
Phenolics are among the most widely distributed, naturally occurring
compounds in fruits and vegetables. They are present at high levels in
coffee, tea, orange juice, and apple juice. (See Table E-2.)
Table E-l. LEVELS OF PHENOLIC-TYPE COMPOUNDS IN SAMPLES
TAKEN AT VARIOUS POINTS IN CITRUS PACKINGHOUSES IN
THE RIDGE AND INDIAN RIVER DISTRICTS
Phenolic Content
Sample (ppm SOPP-equivalent)
Plain water rinse 6-28
Plain water rinse 12.38
Nonphenolic detergent rinse 32.47
Color-Add solution 6'28
Final rinse after SOPP application 51.80
Final rinse after SOPP application 98.47
Final rinse after SOPP application 106.71
Final rinse after SOPP application 214.18
Final rinse after SOPP application 1192.50
Final packinghouse effluent
135 35
Final packinghouse effluent
105
-------
Table E-2. LEVELS OF FREE AND CONJUGATED PHENOLICS
AS DETERMINED BY THE 4-AMINOANTIPYRINE METHOD
IN FOUR COMMON BEVERAGES
Phenolic Content
(ppm SOPP-equivalent)
Beverage
Orange juice
Apple juice
Tea
Coffee
Free
170.2
109.7
936.1
1885.2
Conjugated
364.8
586.6
289.2
1891.3
Cold press oil (peel oils) from the extraction of oranges is one of
three products from oranges, the other two being orange juice and peel.
The peel oils contain natural fungicidal or bacteriostatic agents and
have been known to cause problems with the operation of activated sludge
. E~2, E—3
systems.
106
-------
REFERENCES
E-l Ismail, M. A., and W. F. Wardowski, "Phenolic Contaminants in
Florida Citrus Packinghouse Effluents: Sources and Regulations,"
Florida State Horticulture Proceedings, Vol. 86, 1973 (published
1974).
E-2 Winter Garden Citrus Products Cooperative, Complete Mix Activated
Sludge Treatment of Citrus Process Wastes. EPA 12060 EZY, August
1971.
E-3 Coca Cola Company Foods Division, Treatment of Citrus Processing
Wastes, EPA 12060 , October 1970 .
107
-------
Appendix F
PESTICIDE LEVELS IN WASTEWATERS FROM SWEET
POTATO PROCESSING OPERATIONS
Sweet potato weavils have Long been a serious pest in sweet potato
storage areas in southwestern Louisiana. Before DDT was banned, about
1 ounce of 10% DDT dust was applied to each crate of potatoes to deter
weavils. On a whole potato basis, this averages to about 100 ppm. Sweet
potatoes were washed after storage, which reduced the DDT residue to
1 ppm or less. Impson, Epps, and Smilie^"-*- have studied sweet potato
processing operations but their data are insufficient to allow quantifica-
tion of the problem on the basis of production rate. Table F-l shows
the concentration of DDT in a 5000 gallon per hour wastewater stream be-
fore and after treatment. Note that DDT removed from the water will be
present in the sludge and hence must be considered in the selection of
method for solid waste disposal.
F-l.
Impson, J. W., E. A Epps, Jr., and J. L. Smilie, "Removal of DDT
from Sweet Potato Washwater," Bulletin of Environmental Contamination
and Toxicology, .13 (1), 37 (1975).
108
-------
TABLE F-l. DDT CONCENTRATIONS IN TREATED AND
UNTREATED SWEET POTATO WASH WATER
Run
1
2
3
4
5
6
7
8
9
10
11
Treatment
Check, no treatment
Check, no treatment
10 Ib lime /hour (1)
3 Ib lime/ 1000 gal
6 Ib lime/1000 gal
6 Ib lime/ 1000 gal
12 Ib lime/1000 gal
12 Ib lime/1000 gal +
ferrous sulfate
6 Ib lime/ 1000 gal,
baffles & filter
6 Ib lime/1000 gal,
filter
6 Ib lime/ 1000 gal,
filter
DDT in Untreated
Entrance. Pit #1
2,027
300
1,071
12,495
3,800
6,108
18,021
18,609
7,734
13,796
4,045
Wash Water (ppb)
Exit. Pit #2
211
226
305
630
179
192
225
481
185
78
35
Percent
removal
after
treatment
90%
25
74
95
96
97
99
97
98
99
99
Source: Reference F-l.
109
-------
Appendix G
R&D WORK ON WASTEWATER REUSE FOR A CANNERY
INTRODUCTION
Reuse and recycling of wastewater in canning operations has the
potential for greatly decreasing the volume of wastewater from the industry.
Cascading reuse operations from high to low water quality uses or recy-
cling in one operation (such as fluming or washing) have already been
demonstrated. Questions concerning the public health aspects of reuse and
recycle do arise, however, because of possible food contamination from
recycled water containing pesticide residues, heavy metals, or pathogenic
organisms. The EPA awarded Grant No. S803280 in August 1974 to Snokist
Growers of Yakima, Washington, to conduct a 3-year project to test
reuse of treated wastewater within a fruit processing operation.
BACKGROUND
Snokist Growers was initially awarded a grant to conduct testing
of an aerobic wastewater treatment system beginning in August 1967.
During the project it was demonstrated that activated sludge or contact
stabilization treatments can provide greater than 90% removal of
soluble organics and suspended solids from the effluent. The main
commodities processed at this facility include apples, pears, peaches,
plums, and some tomatoes for juice. [For more information see "Aerobic
Treatment of Fruit Processing Wastes," Water Pollution Control Research
Series 12060FAD(10/69).]
TREATMENT PLANT OPERATION
In the aeration tank of the activated sludge system (with a 3-day
detention time), more than 99% of the soluble organic component of the
wastewater (BOD) is removed and converted to suspended biological matter
that is removed by settling in the final clarifier. Clarified effluent
is split and a portion of it is given further treatment before it is
reused in the cannery. The reusable portion is pumped through two
pressure filters, and then chlorinated as shown in Figure G-l.
110
-------
SCREENED
WASTE
METERING & FLOW
DISTRIBUTION 6OX
NUTRIENT (N&P)
ADDITION
TO REUSE
IN CANNERY
EFFLUENT
TO RIVER
SLUDGE
RE AERATION
(§)
BASIN
BACK
WASH
CHLORINE
CONTACT
CHEMICAL
, ^ADDITION
MULTI-
MEDIA
FILTERS
SLUDGE
THICKENER
CANNERY
Vi RAW WATER
f 8\SUPPLY
^ ©
•WASTE FLOW
--- RETURN SLUDGE FLOW -ACTIVATED SLUDGE
------ RETURN SLUDGE FLOW - ACTIVATE D SLUDGE -WITH
SLUDGE RE AERATION
(OlV— SAMPLE POINT NUMBER
SOURCE: Detailed work plan for EPA Grant No. 2-803280, "Reuse of Treated Fruit Processing
Wastewater Within a Cannery."
Figure G-l. Schematic flow diagram of wastewater treatment system
for snokist growers.
Ill
-------
The total plant wastewater flow averages less than 2 million gallons
per day during the main canning season..
The reused water has been applied to equipment cleaning, boiler
feed, and direct contact container cooling. Chemical and bacteriological
tests to date indicate that the reused water appeared to be suitable for
these uses.
WATER REUSE TESTING PROGRAM
The product water was analyzed for trace contaminants and the results
were compared with those for the plant tap water supply. Table G-l shows
the results of pesticide analysis. Table G-2 shows the results of vola-
tile halogenated organics analysis, and Table G-3 presents the results
of trace metal analysis. The preliminary results indicate that the
amounts of pesticides, halogenated organics, or trace metals in the
wastewater are not significant relative to the plant water supply quanti-
ties. The multi-media filter to remove turbidity and suspended solids
has not been as effective as expected. The alkalinity of the reused
water is greater than that of tap water, probably due to caustic peeling.
Hardness of the reused water appears to be slightly less than that of
tap water. Chlorides and sulfates are both higher in the reused water
than in the tap water; Monitoring of the bacteriological quality of
reused water showed that fecal coliform organisms were suitably reduced
during chlorination. However, the total coliform organism removal was
not as consistent as that for fecal coliform organisms.
112
-------
TABLE G-l. PESTICIDE CONCENTRATIONS IN REUSED AND TAP WATER
AT SNOKIST GROWERS' FRUIT PROCESSING PLANT
(|jg/llter)
t-t (•« o to
« U «
•O O -< O. O. O. O. (1) T) X O.O.OC5 PUpOMK
—i as j: • • • - -rf c S
Reused
water <0.001 <0.001 <0.005 <0.001 <0.001 <0.00l <0.003 <0.001 <0.003 <0.060 <0.001 <0.001 <0.001 <0.015 <0.010
Tap
water <0.001 <0.001 <0.005 <0.001 <0.001 <0.001 <0.003 <0.001 <0.003 <0.060 <0.001 <0.001 <0.001 <0.015 <0.010
Reused
water <0,001 <0.001 <0.005 <0.001 <0.001 <0.001 <0.003 <0.001 <0.003 <0.060 <0.001 <0.001 <0.001 <0.015 <0.010
Tap
water <0.001 <0.001 <0.005 <0.001 <0.001 <0.001 <0.003 <0.001 <0.003 <0.060 <0.001 <0.001 <0.001 <0.015 <0.010
Source: EPA Region X Laboratory, Seattle.
-------
TABLE G-2. VOLATILE HALOGENATED ORGANICS —
SNOKIST GROWERS'WASTEWATER REUSE PROJECT
Date
11-4-75
11-4-75
11-17-75
11-18-75
12-16-75
12-16-75
Description
Reused Water
Tap Water
Reused Water
Tap Water
Tap Water
Reused Water
Volatile Chlorinated Organics
as Chloroform
1000. K
1000. K
3.K
20.
(Confirmed
3.K
3.K
by GC/MS)
* K indicates less than
The technique was improved by the second and third sampling for
increased sensitivity.
Source: From EPA Region X Laboratory, Seattle, Washington.
114
-------
TABLE G-3. TRACE METAL ANALYSES FOR REUSED AND TAP WATER AT SNOKIST
GROWERS FRUIT PROCESSING PLANT
(ppm)
Metal
Pb
As
Zn
Sn
Cu
Cd
Hg
Ca
Mg
Fe
Na
K
Mn
Al
Reused
water
<0.05
<0.05
0.50
Not done
<0.05
<0.03
<0.0002
6.0
<0.5
<0.1
60
17
<0.05
<0.10
Reused
water
<0.05
<0.05
0.50
Not done
<0.05
<0.03
<0.0002
7.0
<0.5
<0.1
60
16
<0.05
<0.10
Reused
water
<0.05
<0.05
0.02
Not done
<0.05
<0.03
0.0003
6.0
<1.0
<0.1
60
15
<0.05
<0.10
Waste-
water
<0.05
Not done
Not done
<3.0
<0.05
<0.03
0.0004
11.6
1.8
0.9
17
16
<0.05
0.50
Clarifier
Effluent
<0.05
Not done
Not done
<3.0
<0.05
<0.03
0.0008
11.0
1.3
<0.2
24
7.0
<0.05
<0.2
Reused
water
<0.05
Not done
0.15
<3.0
<0.05
<0.03
0.0009
11.0
1.3
<0.2
22
7.0
<0.05
2.2
Tap
water
<0.05
Not done
Not done
<3.0
<0.05
<0.03
0.001
12.5
1.8
<0.2
15
3.0
<0.05
<0.2
Source: EPA.
-------
Appendix H
R&D WORK ON TREATMENT AND REUSE
OF POULTRY PROCESSING WASTEWATER
INTRODUCTION
Sterling Processing Corporation, a company engaged in the slaughter-
ing, eviscerating, and processing of poultry, is located in Oakland, MD.
The community water supply serving the town of Oakland is of inadequate
capacity to provide water to the poultry plant, and groundwater resources
in the area are limited and of unsatisfactory quality. Production at the
Sterling plant has been limited by the availability of potable water,
with frequent interruptions to operations resulting from water shorages.
The Maryland State Department of Health was awarded EPA Grant No.
12060-FYG to study treatment and reuse of poultry processing wastewater
at Sterling Processing Company from 1970 to 1973. The primary objective
of the project was to demonstrate the technical and economical feasi-
bility of reclaiming poultry processing wastewater for reuse where
potable grade water was required.
TREATMENT PLANT OPERATION
Figure H-l is a schematic flow diagram of wastewater treatment at
Sterling Processing Corporation. Wastewater from the poultry eviscerating
plant was screened and treated in two mechanically aerated lagoons in
series. The secondary lagoon effluent was chlorinated. A portion of the
effluent received further treatment before it was reused in the evis-
cerating plant, whereas the rest was discharged to the river.
To reclaim a portion of lagoon effluent, an advanced treatment system
was used. The lagoon effluent was first microstrained for solid removal,
and the microstrained effluent was then treated by coagulation and sedi-
mentation for the removal of colloidal solids. Finally, the water was
chlorinated and filtered prior to combining with well water.
WATER REUSE TESTING PROGRAM
Table H-l compares the water quality in raw wastewater and lagoon
116
-------
i TO RIVER
SAMPLE IDENTIFICATION
A-Screened Raw Wastewater
6-Primary Lagoon Effluent
C -Secondary Lagoon Effluent
D-Microstrained Effluent
X-Flocculated-Settled Effluent
E-Filtered Water
CO
.. 1 .• BA,
LLECTION
SIN
CHLORINE JL
CONTACT O
CHAMBER |Lk-*^ C
LAGOON
NO. 2
I. , i1
H
LAG(
NO
A —-^J '
ROTARY ^^
SCREENS II
1
DON ^J#&^
C
EVISCERATING PLANT
r
~J MICROSTRAINER
S [ 1 SEDI
X ^3 CHLORIN
i 1 . PRESS
1 1 STORA
' 1 ' TANK
^\ SAND
\J FILTER
i
- r-
* L_
JCULATION-
MENTATION
M
ATOR
URE
GE
£
WELL WATER
— I WATER
1 TREATMENT
SOURCE: EPA
SA-5619-23
Figure H-l. Wastewater treatment and water reclaiming facilities for
sterling processing corporation.
117
-------
effluents. Table H-2 indicates the effectiveness of each step in an
advanced treatment system in removing contaminants.
Results of chemical and physical examinations of reclaimed water
are shown in Table H-3.
During the study period, 352 bacteriological samples of filtered
water from the advanced water treatment system were collected and exam-
ined for coliform, fecal streptococci, and total plate counts. A
chlorine application rate of 9.09 kg/day (8 mg/liter) prior to filtering
resulted in consistent bacteriological counts < 3 coliform/100 ml; < 1
fecal streptococci/100 ml; and a standard plate count of < 100/ml. The
chlorination rate of 27-36 kg/day, necessary to reach "breakpoint",
provides additional assurance of bacteriological safety of the water.
TABLE H-l. EFFECTIVENESS OF WASTEWATER LAGOON SYSTEM
(mg/liter) __^
Raw
Was_tewatjer
N X 0
Primary Lagoon Secondary Lagoon
Effluent_ Effluent _
N X 0 N X 0
BOD5
COD
148
7
543
863
229
183
79
8
251
235
176
83
210
8
39
91
40
20
Suspended
Solids 119 831 464
Grease
47 403 239
67 392 342
10 95 90
214 117 100
78 18 17
N = Number of Samples; X = Mean Value; 0 » Standard Deviation.
Source: EPA.
118
-------
TABLE H-2. SFFECTIVEKSS OF ADVANCED TREATMENT SYSTEM*
Lagoon Microstrainer Settled Filtered
Effluent Effluent-70|jl Water Water (Sand)
NM NM NM N M
BOD5 36 24 25 10 25 6 40 0.5
COD 4 91 4 79 4 49 4 4.1
Suspended
solids 37 149 25 96 25 38 32 5.1
Grease 18 13 86 54 16 3.6
*
N - Number; M - Median Value
Source: EPA .
119
-------
TABLE H-3. CHEMICAL-PHYSICAL QUALITY OF RECLAIMED WATER
(mg/llter)
Turbidity (JTU)
Color
Pesticides
PH
Alkalinity
Hardness
Dissolved solids
Chloride
Cyanide
Fluoride
Nitrate (NO )
J
Phosphate
Sulfate
Aluminum
Arsenic
Cadmium
Calcium
"Chromium
Copper
Iron
Lead
Manganese
Mercury
Potassium
Selenium
Silver
Sodium
Drinking Water
Standard-1962
5
15
500
250
0.2
1
45
250
0.05
0.01
0.05
1.0
0.3
0.05
0.05
0.005
0.01
0.05
270
N
54
90
16
207
101
22
158
162
8
23
89
47
23
17
26
8
26
8
26
27
8
10
8
20
8
8
19
X
3.5
5
0
6.6
104
131
335
117
0
0.21
31
10
13
0.03
0.01
<0.01
46
<0.01
0.06
0.27
0.01
0.02
0.003
10.7
<0.01
<0.01
21
0
1
7
1.4
57
24
129
53
0.13
8
2
5
0.04
0.01
0
12
0
0.01
0.19
0.01
0.02
0.003
9.5
0
0
15
N - Number of Samples; X
Source: EPA.
Mean Value; 0 = Standard Deviation
120
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
EPA-600/2-79-009
TITLE AND SUBTITLE
Overview of the Environmental Control Measures and
Problems in the Food Processing Industries
5. REPORT DATE
January 1979 issuing date
6. PERFORMING ORGANIZATION CODE
. AUTHOR(S)
J.L. Jones, M.C.T. Kuo, P.E. Kyle, S.B. Radding,
K.T. Semrauf L.P. Somogvi
9. PERFORMING ORGANIZATION NAME AND ADORES
SRI International
333 Ravenswood Ave.
Menlo Park, CA 94025
3. RECIPIENT'S ACCESSION-NO.
8. PERFORMING ORGANIZATION REPORT NO
10. PROGRAM ELEMENT NO.
IB:
11. CONTRACT/GRANT NO.
R804642-01-2
1AB60U
12. SPONSORING AGENCY NAME AND ADDRESS
Industrial Environmental Research Lab.
Office of Research and Development
U. S. Environmental Protection Agency
Cincinnati. Ohio 1+5268
- Cinn, OH
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
EPA/600/12
15. SUPPLEMENTARY NOTES
16. ABSTRACT
In conducting the assessment of the pollution sources and control measures
utilized by the food processing industries (those industries listed under SIC 20) ,
the water pollution control, air pollution control and solid waste management
practices of 19 specific food processing industries were reviewed. The 19 industries
analyzed represent in excess of 75% of the total value of shipments by the food
processing industries. One specific objective of the assessment was to identify
any potential toxic substances emission problems. The method of approach used
in conducting the study was to prepare process descriptions on a unit operations
basis for each industry and.to identify the sources of emissions and effluents
from each major step in the process. These process descriptions along with a
general industry description are contained in 18 unpublished appendices available
from the EPA Food and Wood Products Branch in Cincinnati, Ohio. The published
volume of the report and its eight published appendices discuss the major sources
of water pollution, air pollution, and solid wastes from the food processing
industries. The appendices address specific topics such as SOX emissions, poly-
nuclear aromatic hydrocarbons, phenolic compounds, and water reuse (including
pesticides).
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b. IDENTIFIERS/OPEN ENDED TERMS
COSATl Field/Group
Air pollution
Food Processing
Waste water
Solid wastes
Water utilization
Waste characterization
13B
3. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS
Unclassified
133
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
121
U. S. GOVERNMENT PRINTING OFFICE: 1979 — 657-060/1575
------- |