iPA-660/2-74-058 X
June 1974
Environmental Protection Technology Series
Proceedings- Fifth National
Symposium on Food
Processing Wastes
of Research and
U.S. EnvironmentaI Protection
Corvallis, Oregon
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and
Monitoring, Environmental Protection Aqency, have
been grouped into five series. These five broad
categories were established to facilitate further
development and application of environmental
technology. Elimination of traditional grouping
was consciously planned to foster technology
transfer and a maximum interface in related
fields. The five series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
This report has been assigned to the ENVIRONMENTAL
PROTECTION TECHNOLOGY ; series. This series
describes research performed to develop and
demonstrate instrumentation, equipment and
methodology to repair or prevent environmental
degradation from point and non-point sources of
pollution. This work provides the new or improved
technology required for the control and treatment
of pollution sources to meet environmental quality
standards.
EPA REVIEW NOTICE
The Office of Research and Development has reviewed this report
and approved its publication. Mention of trade names or
commercial products does not constitute endorsement or recommen-
dation for use.
For sale by the Superintendent of Docun ents, U.S. Government Printing Office, Washington, D.C. 20402- Price $3.80
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EPA-660/2-74-058
June 1974
PROCEEDINGS FIFTH NATIONAL SYMPOSIUM
ON FOOD PROCESSING WASTES
April 17-19, 1974
Monterey, California
INDUSTRIAL WASTES BRANCH
Pacific Northwest Environmental Research Laboratory
Environmental Protection Agency
Corvallis, Oregon
Co-sponsored by:
NATIONAL CANNERS ASSOCIATION
CANNERS LEAGUE OF CALIFORNIA
Roap/Task 21 BAB 102
Program Element #1BB037
Prepared for
NATIONAL ENVIRONMENTAL RESEARCH CENTER
OFFICE OF RESEARCH & DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CORVALLIS, OREGON 97330
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FOREWORD
The Fifth National Symposium on Food Processing Wastes was co-sponsored
with the National Canners Association and the Canners League of Cali-
fornia.
These symposia were instituted for the purpose of disseminating the
latest information obtained from research, development and demonstration
projects to industry, consultants and government. There was a definite
need to shorten the time between completion of the projects and making
the information available to the potential users.
As noted in the Proceedings from the Fourth Symposium, a greater emphasis
is being placed upon process modifications and by-product recovery in an
attempt to reduce end-of-pipe treatment costs. In addition, one paper
discusses effluent polishing and partial reuse back in the processing
plant. Additional projects such as this will be initiated during the
next few years.
With continued cooperation between the various entities, the desired
water quality goals will be achieved in an optimal manner within the
economic and time constraints imposed.
11
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CONTENTS
OPENING REMARKS 1
B. A. Filice
EXPERIENCE WITH LAND TREATMENT OF FOOD PROCESSING 4
WASTEWATER
R. W. Crites, C. E. Pound and R. G. Smith
USE OF MUNICIPAL PERMIT PROGRAM FOR ESTABLISHING 31
FAIR WASTEWATER SERVICE CHARGES
R. T. Williams
USE OF ROTATING BIOLOGICAL CONTACTOR ON MEAT 53
INDUSTRY WASTEWATERS
D. F. Kincannon, J. A. Chittenden and E. L. Stover
INDUSTRIAL WASTEWATER REUSE 67
J. D. Clise
REMOVAL OF PROTEIN AND FAT FROM MEAT SLAUGHTERING 85
AND PACKING WASTES USING LIGNOSULFONIC ACID
T. R. Foltz, Jr., K. M. Ries and J. W. Lee, Jr.
DESIGN CONSIDERATIONS FOR TREATMENT OF MEATPACKING 107
PLANT WASTEWATER BY LAND APPLICATION
A. Tarquin, H. Applegate, F. Rizzo and L. Jones
CLEANING AND LYE PEELING OF TOMATOES USING 114
RUBBER DISCS
R. P. Graham
INTEGRATED BLANCHING AND COOLING TO REDUCE 120
PLANT EFFLUENT
J. L. Bomben, G. E. Brown, W. C. Dietrich,
J. S. Hudson and D. F. Farkas
RECOVERY OF ACTIVATED SLUDGE FOR POULTRY FEED 132
ENGINEERING ASPECTS
R. H. Jones and L. P. Levine
EVALUATION OF ACTIVATED CITRUS SLUDGE AS A 142
POULTRY FEED INGREDIENT
B. L. Damron, A. R. Eldred, S. A. Angalet,
J. L. Fry and R. H. Harms
iii
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INVESTIGATION OF RUM DISTILLERY SLOPS TREATMENT 155
BY ANAEROBIC CONTACT PROCESS
T. G. Shea, E. Ramos, J. Rodriquez and G. H. Dorion
GULF SHRIMP CANNING PLANT UASTEWATER PROCESSING 199
A. F. Maul din and A. J. Szabo
UASTEWATER CHARACTERIZATION FOR THE SPECIALTY 218
FOOD INDUSTRY
C. J. Schmidt, E. V. Clements III and J. Farquhar
PAUNCH MANURE AS A FEED SUPPLEMENT IN CHANNEL 246
CATFISH FARMING
S. C. Yin
PRETREATMENT OF VEGETABLE OIL REFINERY WASTE WATER 258
A. Grinkevich
BIODEGRADABILITY OF FATTY OILS: A CASE STUDY 269
T. K. Nedved and C. F. Gurnham
ECONOMIC EFFECTS OF TREATING FRUIT AND VEGETABLE 280 \/
PROCESSING LIQUID WASTE
N. A. Olson, A. M. Katsuyama and W. W. Rose
INVESTIGATIONS OF FISHERY BY-PRODUCTS UTILIZATION: 300
RUMINANT FEEDING AND FLY LARVA PROTEIN PRODUCTION
J. H. Green, S. Cuppett and H. J. Eby
LIST OF PARTICIPANTS 313
iv
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OPENING REMARKS BY MR. BRUNO A. FILICE *
I am most pleased that this Symposium is taking place in California
and that the Canners League of California is a co-sponsor. On behalf
of the Officers and members of the Canners League, I welcome you—and,
most especially, those who do not enjoy the privilege of year-round living
in our Golden State. We hope that you enjoy your stay in this historic
Monterey Bay area and that you go home recharged, refreshed, and a
bit envious of ,us natives.
The importance of this Symposium as a medium for the disclosure
of new research results—as well as a forum of exchange of unpublished
results, creative insights, and solutions to problems—is recognized by
the industries and their associations.
I would like to state briefly some of the concerns felt by the canning
industry in California. The members of the Canners League are responsible
for approximately thirty per cent of the canned foods packed in the
United States, and naturally, we feel that our input to environmental
planning is important to us and to the nation. The canning industry
endorses environmental protection; in fact, the industry is completely
dependent on adequate supplies of high-quality water to process its
products. Disposal of solid residuals from canning seasonal commodities
is a major problem for California food processors. We want to do every-
thing which is prudent and effective to protect our water, our air,
and our land resources.
We in industry are concerned about the contradictory demands of the
several federal agencies which regulate the food processing industry.
For example, FDA and USDA tell us that we should be using more water in
processing to reach higher levels of sanitation, while EPA regulations
are met most economically by using minimum amounts of water. The employee
safety considerations imposed by OSHA make both FDA and EPA regulations
more difficult to meet at practicable levels of capital expenditures.
A solution to this dilemma could result from a series of discussions by
policy-making officials of the various agencies involved. Hopefully,
guidelines compatible to all interests would be forthcoming from such
meeetings. We would be willing to pinpoint problem areas, as we see them,
if this would be helpful to such deliberations.
A second area of concern for our industry is effluent guidelines,
which are now being developed and published for comment by EPA. We
recognize the impossible nature of the task imposed on EPA in the deadlines
* President, Canners League of California
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established by Public Law 92-500, also known as the Federal Water Pollution
Control Act Amendments of 1972. The recent court actions setting dates
for publication of certain final regulations reflect a misunderstanding
on the part of the judiciary of the magnitude of the challenge faced by
EPA. Given the limited time-frame in which to work, EPA had no choice
but to use contractors to compile data and to make economic evaluations.
The result of all of this activity and expense has been identification
of the best operations in a given industry (in terms of BOD and SS
discharged) and use of these performances as the basis for effluent
guidelines. We feel that this approach does not fully consider important
differences among various food processing commodities and plants. We
recognize and compliment the EPA for establishing sub-categories that
have been used so far. My colleagues with research and development
responsibilities in the canning industry tell me that an EPA Advisory
Committee has recommended a "matrix approach" for establishing guidelines
which is more solidly based scientifically than the present system. The
matrix model includes such considerations as economic equity, production
variations, waste treatment processes, and climatic conditions. We in
the canning industry urge EPA to give further consideration to the matrix
approach for guideline setting which has been recommended to them by
their Advisory Committee chaired by Dr. Martha Sager. We feel that the
use of the matrix format for guideline setting will be more equitable
and more protective of the public interest than the present "single
number" format. I might also add that personal experience in food
research and quality control has demonstrated that the statistical analysis
of our problems has resulted in the most lasting solutions to these
problems; therefore, I wholeheartedly support the "matrix approach"
in this situation.
The third and last area of concern I want to raise this morning is
that much more research and development work on specific industry problems
is needed if we are going to meet the 1983 goals of best available technology
most effectively. We appreciate the substantial support, in terms of
funding of research grants, which EPA has provided to universities, trade
associations, and industrial companies. The results from these projects
are being used, or will be used, to help the canning industry meet its
responsibility for environmental protection. A most notable example
of application of research results is dry caustic peeling. However,
much more research is needed, and promising technology must be demonstrated
with in-plant installations operated under commercial conditions. To
do this, we in industry need continuing and increased financial support
from EPA and other federal agencies. The canning industry is spending
almost all of its available dollars on in-plant changes to provide
essential food at reasonable costs to the consumer without polluting
the environment. We simply do not have additional dollars to support
large scale research projects beyond our long-standing practice of matching
every seven EPA dollars with three dollars from the industry, funnelled
through our trade associations or by our support of university research
projects. We expect to continue this financial support in the years
ahead.
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I appreciate this opportunity to speak frankly about some of the
concerns of the food canning industry. We in industry want to be good
environmental citizens, and we look forward to closer cooperation with
EPA to protect the environment. All of us—our children—must live in
this world, which is the only one we have—space exploration notwithstanding-
and it must be properly protected. At the same time, we all have a
responsibility to help use resources and tax dollars most wisely.
Thank you—and have an excellent Symposium.
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EXPERIENCE WITH LAND TREATMENT
OF FOOD PROCESSING WASTEWATER
by
Ronald W. Crites*, Charles E. Pound*, and Robert G. Smith*
BACKGROUND
Food processing wastewaters have been applied to the land
through engineered systems for more than 25 years. Major
interest began in the late 1940s with the objective being
primarily waste disposal. In 1934, corn and pea canning
wastewater was applied to the land using the ridge and fur-
row method at Hampton, Iowa(l). Boltontl) reported that in
a 1942 study, the treatment capability of this soil system
was investigated for the first time and was found to be on
the order of 50 to 80 percent removal of BOD at a BOD
loading of 650 Ib/acre/day.
Since then a wide variety of food processing wastewaters has
been applied to the land. Grape stillage was reported(2) in
1947 to be applied by flooding at a rate of 3.7 in./day
followed by 6 days of resting. Spray irrigation of cannery
waste was first reported(3) in 1947 at Hanover, Pennsylvania.
Drake and Bieri(4) reported on 4 spray irrigation and 2 ridge
and furrow irrigation systems in Minnesota in 1951. In 1950
a large, high-rate, spray irrigation system was put in opera-
tion at Seabrook Farms, New Jersey(5). Cannery wastewater
was applied to a wooded area at a rate of 8 in./day. Al-
though the existing trees on the sandy soil have been mostly
replaced by marsh grass, the operation continues successfully
today(6).
In 1951 citrus wastes were reported'-'7) to be successfully
applied to the land in California using a modified ridge and
furrow technique called "back-furrows." In 1955 sugar beet
wastewater was applied to grassland by flooding at Bayard,
Nebraska(S) and a reduction of 67 percent of the BOD applied
was found in the runoff. Wastewater was also being applied
to cash crops as Bell(9) reported that poultry wastes were
used to spray irrigate 40 acres of alfalfa in Lowell,
Arkansas.
*Metcalf § Eddy, Inc., Palo Alto, California
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Many of these early installations were loaded on the basis
of successful experience elsewhere, without proper regard
for different soil and drainage characteristics. As a
result many systems failed and in the process land treat-
ment began to receive some adverse publicity. Today's "zero
discharge" requirements, however, coupled with improved
understanding of the capabilities and limitations of soil
systems have renewed interest in land treatment.
A survey(lO) in 1964 resulted in the identification of 844
systems applying food processing wastewater to the land.
Pennsylvania had the largest number of systems (143)
followed by Wisconsin (141) and California (131) . In 1972
as a result of surveys and studies by the American Public
Works Association (APWA)Ul) and Metcalf $ Eddy, Inc.C6),
data on more than 85 operating systems were collected. These
reports serve as the basis for much of the information pre-
sented in this paper.
LAND TREATMENT PROCESSES
Land application systems for treatment and disposal of food
processing wastes are normally categorized into three types
of systems based on differences in liquid loading rates and
therefore land area requirements as well as differences in
the interaction of the wastewater with vegetation and soil.
These three categories are referred to as (1) irrigation,
(2) overland flow, and (3) infiltration-percolation.
Selection of the type of system at a given site is primarily
governed by the drainability of the soil because it is this
property that largely determines the allowable liquid
loading rate. Schematic diagrams indicating the major pro-
cess characteristics of each of the systems is shown in
Figure 1. A summary of the comparative characteristics of
the three systems is presented in Table 1.
Table 1. Comparative Characteristics of Land Treatment Systems
Type of treatment system
Factor
Irrigation
Overland flow
Infiltration-
percolation
Liquid loading 0.1 to 0.6 . 0.25 to 0.7
rate, in./day
Land required, 60 to3?0 plus buffer 50 to 150 plus
acre/mgd zone buffer zone
Greater than 0.6
Less than 60
Soil type Moderately permeable, Slowly permeable, Rapidly permeable,
loamy sand to clay clay loam and clay sands to sandy loam
Application
method
Spray or surface
Spray
Spray or surface
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EVAPORATION
SPRAY OR
SURFACE
APPLtCATION
ROOT ZONE
SUBSOIL
SPRAY APPLICATION
SLOPE 2-4%
SLOPE
VARIABLE
-DEEP
PERCOLATION
(a) IRRIGATION
EVAPORATION
GRASS AND VEGETATIVE LITTER
RUNOFF
COLLECTION
(b) OVERLAND FLOW
EVAPORATION
SPRAY OR
-SURFACE APPLICATION
»*s*rinuTi8
8F AERATION
AUO TREATMENT
RECHARGE HOUND ^^?^JttWA<<'Z'^^^ ***"
'-*-*-*-* * * *-*-•-•-•-*-*-*.•-*.-*•• '^ .•-•-•-*-*.*-•.* • »J&*.*.*.».*.•.•!• 1 Y*f* * T* «•>%?-*-».»»»,».* » *•' fc.»^»1» «.•_•.•.*.•_•_ •.*.*_•_».*. ,•
OLD WATER TABLE-
(c) INFILTRATION-PERCOLATION
FIGURE 1
LAND APPLICATION APPROACHES
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Irrigation
Irrigation is considered to include those systems where
wastewater is applied to land by either spray or surface
techniques at normal agricultural irrigation rates or some-
what in excess of those rates. Liquid loading rates
generally range from about 0.1 in./day to 0.6 in./day. At
these loading rates, land requirements range from about 60
to 370 acres per mgd of wastewater, plus a buffer zone.
Loamy, well-drained soil is most suitable for irrigation
systems, particularly where crop production is a major goal
of the operation. However soil types from clays to sands
have been found to be acceptable. A minimum soil depth of
5 feet above groundwater is preferred to prevent saturation
of the root zone. Underdrain systems have been used suc-
cessfully to adapt to high groundwater or impervious sub-
soil conditions.
The objective of most irrigation systems for food processing
wastewaters is to maximize hydraulic loadings rather than
crop production. The result is that most systems use a
water tolerant perennial grass as a cover crop. A few
systems use higher valued crops, such as alfalfa or corn,
for cover vegetation, but these have only been successful
when standard irrigation practices have been followed.
Cover vegetation plays an important role in irrigation
systems. This is particularly true in spray application
systems where the cover vegetation prevents soil erosion
and sealing of the soil surface due to the action of water
droplets. The root structure of cover vegetation also aids
in maintaining the infiltrative capacity of the surface by
expanding the soil and promoting dispersion of clogging
materials. Plants are also largely responsible for re-
moval of nutrients such as nitrogen and phosphorus. Re-
moval of the organic materials in the wastewater is
accomplished primarily by microorganisms residing in the
soil.
A few systems employing surface application techniques,
such as border strip or ridge and furrow irrigation, do not
use cover crops because the wastewater is either toxic to
plants or contains a high suspended solids load that would
be trapped by a cover crop at the head of an irrigated
strip.
In irrigation systems most of the applied wastewater is
either consumed through evapotranspiration or percolates
through the soil to become groundwater. Evaporative con-
sumption generally is equal to or greater than percolation.
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A portion of the applied wastewater may appear as surface
runoff. Failure to adequately control this runoff is a
common source of problems at existing systems.
Overland Flow
The overland flow technique is an adaptation of spray irri-
gation to impermeable or poorly drained soils. The tech-
nique was pioneered in 1954 by the Campbell Soup Company
at Napoleon, Ohio, and was studied in depth at the Campbell
installation at Paris, Texas(12, 13). Until recent studies
with municipal wastewaters were performed'--'-^', its appli-
cation had been restricted to the food processing industry.
Overland flow differs from spray irrigation primarily in
that a substantial portion of the wastewater applied is
designed to run off and must be collected and discharged to
receiving waters, or in certain cases where wastewater is
produced only during part of the year, stored for deferred
application. An overland flow system therefore functions
more as a land treatment system than a land disposal system.
Wastewater is applied by sprinklers to the upper two-thirds
of sloped terraces that are 100 to 300 feet in length. A
runoff collection ditch or drain is provided at the bottom
of each slope. Treatment is accomplished by bacteria on
the soil surface and within the vegetative litter as the
wastewater flows down the sloped, grass-covered surface to
the runoff collection drains. Ideally, the slopes should
have a grade of 2 to 4 percent to provide adequate treat-
ment and prevent ponding or erosion. The system may be used
on naturally sloped lands (such as the two Campbell Soup
Company installations at Napoleon, Ohio, and Paris, Texas)
or it may be adapted to flat agricultural land by reshaping
the surface to provide the necessary slopes.
Higher liquid loading rates are possible with the overland
flow technique than with conventional spray irrigation.
These rates may range between 0.25 to 0.7 in./day, resulting
in a land requirement of about 50 to 150 acres plus buffer
zone for each mgd applied.
As mentioned previously, the system is especially suited to
use with slowly permeable soils such as clays or clay loams.
With this type of soil very little water percolates to the
groundwater. Most of it appears as surface runoff or is
consumed by evapotranspiration.
A cover crop is essential with the overland flow system to
provide slope protection and media for the soil bacteria
as well as to provide nutrient removal by plant uptake.
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A water tolerant perennial grass such as Reed canary grass
or tall fescue has been found to be suitable to the high
liquid loading rates.
Infiltration-Pereolation
Infiltration-percolation systems are characterized by per-
colation of most of the applied wastewater through the soil
and eventually to the groundwater. The method is restricted
to use with rapidly permeable soils such as sands and sandy
loams. This type of system is normally thought to be
associated with recharge or spreading basins although in
food processing applications high-rate spray systems have
been used to provide distribution of the wastewater. In
actual practice there is not a definite division between
irrigation systems previously described and high-rate spray
infiltration-percolation systems, but rather a complete
spectrum of operations with liquid loading rates ranging
from 0.1 in./day to 12 in./day. For purposes of discussion,
an average loading rate of 0.6 in./day is used as an arbi-
trary dividing point between the two types of systems. At
this minimum loading rate, infiltration-percolation systems
would require about 60 acres plus a buffer zone for each
mgd applied.
The use of recharge or spreading basins for treatment and
disposal of food processing wastewaters has been limited
primarily due to the high organic strength and high solids
concentration of typical wastewaters. These constituents
clog the soil surface and make it difficult to maintain
consistently high soil infiltration rates.
Vegetation is essential in high-rate spray systems to pro-
tect the infiltrative surface. For spreading basins cover
vegetation would normally not be used for wastewaters con-
taining a high solids concentration because it would tend
to entrap solids and prevent satisfactory distribution in
the basin.
In infiltration-percolation systems, plants play a rela-
tively minor role in terms of treatment of the applied waste-
water. Physical, chemical, and biological mechanisms
operating within the soil are responsible for treatment.
The more permeable the soil, the further the wastewater must
travel through the soil to receive treatment. In very sandy
soils this minimum distance is considered to be approximately
15 feet.
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WASTEWATER QUALITY AND PRETREATMENT REQUIREMENTS
Wastewater Characteristics
The characteristics of food processing wastewaters that must
be considered with regard to land treatment include BOD and
COD, suspended solids, total fixed dissolved solids, nitro-
gen, pH, temperature, heavy metals, and the Sodium Adsorption
Ratio (SAR). These characteristics vary widely among food
processing wastes applied to the land. Ranges of values
observed at existing land treatment systems for these char-
acteristics are listed in Table 2. The possible effects of
these characteristics are discussed in the following
paragraphs.
Table 2. Characteristics of Various Food
Processing Wastewaters Applied to the Land
Constituent Unit Value range
BOD mg/1 200 - 4,000 '
COD mg/1 300 - 10,000
Suspended solids mg/1 200 - 3,000
Total fixed
dissolved solids mg/1 less than 1,800
Total nitrogen mg/1 10 - 400
pH -- 4.0-12.0
Temperature deg. F less than 150
BOD and COD - The ratio of BOD to COD is a measure of bio-
degradability of the wastewater. Most food processing
wastewaters are readily degradable and exhibit a high BOD
to COD ratio. The soil is a highly efficient biological
treatment system, therefore, liquid loading rates at land
treatment operations are normally governed by the hydraulic
capacity of the soil rather than the organic loading rate.
This operational independence from BOD loading is a distinct
advantage of land treatment systems over conventional in-
plant systems in treating high-strength wastewaters.
10
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There are limits, of course, to the organic loading that
can be placed on the land without stressing the ecosystem
in the soil. The effects of organic overloads on the soil
include damage to or killing of vegetation, severe clogging
of the soil surface, and leaching of undegraded organic
materials into the groundwater. Defining the limiting
organic loading rate for a system must be done on an indi-
vidual basis. However, rule-of-thumb rates have been
developed based on experience. A maximum BOD loading rate
of 200 Ib/acre/day has been suggested as a safe loading
rate for pulp and paper wastewaters(15)> A somewhat higher
rate can normally be used with food processing wastewaters
containing a higher percentage of sugars rather than starchy
or fibrous material. Substantially higher loading rates
(greater than 600 Ib/acre/day) have been used on a short-
term seasonal basis for infiltration-percolation systems.
For overland flow systems, organic loadings in the range of
40 to 100 Ib/acre/day have been used successfully(6).
Suspended Solids - Solids are generally the major source of
operational problems such as clogged sprinklers and clogged
soil surface. Pretreatment to remove solids will normally
minimize these problems.
Nitrogen - Nitrogen in food processing wastewaters is nor-
mally not of major concern because it is usually present in
such concentrations that it is almost completely removed by
bacterial assimilation or crop uptake. Notable exceptions
are feed-lot, dairy, potato processing, and meat packing
wastes. The latter have been found to contribute a signi-
ficant nitrate load to groundwaters.
p_H - Wastewaters that have a pH between 6.0 and 9.5 are
generally suitable for continuous application to most crops
and soils. Wastewaters with pH below 6.0 have been success-
fully applied to soils that have a large buffering capacity.
Temperature - High temperature wastewaters from cooking
operations can sterilize the soil and prevent growth of
cover vegetation.
Heavy metals - The soil has a large capacity to adsorb
heavy metals. Once this capacity is exceeded, however, the
metals may be leached to the groundwater (under acid soil
conditions) or inhibit plant growth.
Sodium Adsorption Ratio (SAR) - The ratio of sodium to other
cations, primarily calcium and magnesium, can adversely
effect the permeability of soils, particularly clay soils.
Wastewaters with a SAR below 8 are considered safe for most
soils. Sandy soils can tolerate higher SAR values^).
11
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Pretreatment
Pretreatment is required in most cases to eliminate frequent
operating difficulties and avoid adverse effects on the
terrain environment.
Screening - Screening with rotary or vibration screens has
been almost universally employed as a form of pretreatment
to separate coarse solids from food processing wastewaters.
Such solids can cause serious problems with wastewater dis-
tribution, particularly with spray applications. Fine
screens at pump intakes or in-line screens in the discharge
piping have also been employed as an added precaution
against sprinkler nozzle clogging.
Lagooning - The use of lagoons or settling ponds prior to
land application of industrial wastewaters has been preva-
lent. Such lagoons serve to remove silt and other suspended
particles which may contribute to clogging of the distribu-
tion system as well as hasten the clogging of soil pore
space. This form of pretreatment is normally used when
applying wastewaters to vegetated fields by flood irrigation
techniques.
pH Adjustment - Industrial wastewaters with sustained flows
outside the pH range of 6 to 9.5 should be neutralized prior
to land application if the site is to be vegetated. Waste-
waters with widely fluctuating flows can be self-neutralizing
if an equalization basin is provided prior to land application,
In other cases a continous pH control system may be necessary.
Cooling - For wastewaters below 150 deg F, application by
sprinkling normally provides sufficient cooling to protect
vegetation and soil. Such cooling may be enhanced by the
use of sprinklers that produce small spray droplets or that
have large spray diameters. Wastewaters with temperatures
much above 150 deg F generally should be cooled prior to
spraying if vegetation is desired.
Nutrient Addition - Nutrient addition in the form of nitrogen
or phosphates may be necessary for nutrient deficient wastes
unless the fields are adequately fertilized.
12
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EXISTING LAND TREATMENT SYSTEMS
The design and management as well as common operating prob-
lems of the different types of systems described above are
discussed through descriptions of several selected existing
operations.
Irrigation Systems
Under the category of irrigation the two basic techniques
of wastewater application employed are spray irrigation and
surface irrigation. Under spray irrigation, variations that
have been observed include solid set sprinklers, portable
sprinklers, and tower spraying. Surface techniques include
border strip flood irrigation with or without crops and ridge
and furrow irrigation also with or without crops. Schematic
diagrams of these three methods of application are shown in
Figure 2.
A selected list of spray irrigation systems handling a wide
variety of food processing wastewaters is presented in
Table 3 along with the major operating characteristics. A
similar list for surface irrigation systems is presented in
Table 4. Typical systems employing each of the various
application techniques are described below.
Solid Set Sprinkler Irrigation - An example of solid set
spraying is the system of the Idaho Supreme Potato Company
in Firth, Idaho. The distribution system is buried with
risers spaced on 80-foot squares discharging at 80 to 100
psi. The spray fields are planted to a mixture of Reed
canary grass, meadow foxtail, and alta fescue with the yield
of hay being 5 tons/acre annually. Potato washing waste-
water passes through vacuum filters with the mud going to
lagoons and the filtrate to the spray fields where it is
mixed with screened wastewater from the potato peeling and
cutting operations. The system is well managed with waste-
water applied in 12 hours followed by 8 to 9 days of resting
in the summer. The system continues to operate during the
winter with ice mounds building up to heights of 5 feet.
The only change in operation is that spraying lasts for 24
hours followed by 16 to 18 days of resting.
Another interesting example of a solid set spray system is
the California Canners and Growers tomato processing in-
stallations at Thornton^ California. This system is unique
in that high-pressure, high-capacity sprinkler guns are
used. These guns are spaced at 170 to 200 foot intervals
on a 60-acre site and have a discharge capacity of approxi-
mately 300 gpm. This type of system results in a lower
13
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RAIN DROP ACTION-
•Jl I J ! J i'l I J I I J J J!
(a) SPRINKLER
COMPLETELY FLOODED
4^vlTL^v\ •-
n n i n n i n
(b) FLOODING
(c) RIDGE AND FURROW
FIGURE 2
BASIC METHODS OF APPLICATION
14
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Table 3. SELECTED SPRAY IRRIGATION SYSTEMS
Location
California Canners 5 Growers
Thornton, California
Sebastopol Coop
Sebastopol, California
Tri Valley Growers
Stockton, California
Western Farmers ASSOG.
Aberdeen, Idaho
Idaho Supreme Potato Co.
Firth, Idaho
Chesapeake Foods
Cordova, Maryland
Gerber Products Co.
Fremont, Michigan
Michigan Milk Prod.
Ovid, Michigan
Stokely-Van Camp
Fairmont, Minnesota
Green Giant Co.
Montgomery, Minnesota
Libby, McNeill 5 Libby
Liepsic, Ohio
Cobb Canning Co.
Cobb, Wisconsin
Type of
wastewater
Tomato
Apple
Tomato
Potato
Potato
Poultry
Food
processing
Milk
Food
processing
Corn, peas
Fruit
Vegetables
Avg
flow,
mgd
2.5
0.3
3.0
0.5
0.6
0.5
0.8
0.25
1.5
1.2
0.66
0.2
Irrigated
area,'
acres
270a
54
165
90
80
40
90
26
400
360
130
22
Average
application
rate,
in. /day
0.34
0.20
0.67
0.20
0.29
0.50
0.33
0.35
0.14
0.12
0.19
0.34
Crops
Grass ,
alfalfa
Grass
Grass
Grass
Grass
Grass
Grass
Grass
Corn, peas,
grass
Grass
Alfalfa
Grass
Soil type
Fine sandy
loam
Clay loam
Clay loam
Clay loam
Silt loam
Sandy loam
Sand
Sand
Clay
Silty clay
loam
Clay
Silt loam
a. 60 acres in spray fields.
Source: APWA and Metcalf 5 Eddy surveys.
Table 4. SELECTED SURFACE IRRIGATION SYSTEMS
Average
Avg application
Type of Method of flow, rate,
Location wastewater application mgd in./day Soil type
Libby, McNeil § Libby
Gridley, California
California Canners § Growers
Thornton, California
J.R. Simplot Co.
Boise, Idaho
Green Giant Co.
Buhl, Idaho
Idaho Fresh Pak
Lewisville, Idaho
Armour Food Co.
Hereford, Texas
Alto Coop Creamery
Astico, Wisconsin
Big Horn Canning Co.
Cowley, Wyoming
Fruit
Tomato
Potato
Corn
Potato
Meat
processing
Milk
Canning
Flood
Flood
Flood
Ridge and
furrow
Flood
Ridge and
furrow
Ridge and
furrow
Ridge and
furrow
2.
2.
3.
1.
1.
1.
0.
0.
5 0.48
5 • 0.29
0
0 0.27
06 0 . 30
15
12 0.15
SO 0.46
Clay
Fine
• loam
--
Silty
Silty
--
Clay
--
loam
sandy
loam
loam
15
-------
capital cost but sacrifices good distribution of wastewater.
This nonuniform distribution contributes to ponding problems
when operating at high liquid loading rates. The spray
field is planted to water grass but not harvested. Prior to
spraying, the raw wastewater is screened and sent through
lagoons to provide settling and flow equalization.
Before expansion of the facilities in 1973, wastewater was
applied to the spray field sections each day on a rotating
basis for 1/2-hour intervals every 3-1/2 hours. The result
was a loading rate of more than 1 in./day. This rate ex-
ceeded the infiltrative capacity of the soil and resulted
in substantial runoff. Although runoff collection and dis-
posal facilities were provided, inadequate land leveling
resulted in widespread ponding. The ponding caused severe
mosquito propagation problems which were compounded by the
very tall grass. In addition, the runoff, which was dis-
charged to a local waterway, did not meet discharge quality
requirements. These conditions were successfully corrected
by the addition of a 150-acre surface irrigation system that
is discussed under that category.
Portable Sprinkler Irrigation - The spray system at Tri
Valley Growers tomato processing installation near Stockton,,
California, is a good example of a portable sprinkler system.
The spray field consists of 165 acres with 90 acres planted
to water grass and 75 acres planted to Sudan grass. The
sprinkler system consists of 16-inch portable aluminum mains
and 4-inch portable laterals with sprinklers on a 60-foot
grid. Although the system is portable, it is operated as a
solid set system without moving the laterals prior to the
end of the season. Pretreatment of the wastewater consists
of coarse screening, a holding pond for equalization and
sedimentation, plus in-line screens in the discharge lines
of the spray system pumps.
Prior to the addition of the 75 acres to the spray fields in
1973, approximately 3 mgd of tomato processing wastewater
was applied to 90 acres with each of nine 10-acre sections
receiving full flow for approximately 3 hours at a time.
The resulting average liquid loading rate was in excess of
1.2 inches per day on a clay loam soil. This application
rate was far in excess of the infiltrative rate of the soil
and the evapotranspiration demand of the cover crop. There-
fore approximately 30 percent of the applied water appeared
as runoff. The runoff was collected and channeled back to
the pumping station for recirculation over the system.
Runoff was not discharged to local receiving waters because
of particularly stringent discharge requirements of 15 mg/1
BOD and 15 mg/1 suspended solids. The recirculated runoff,
therefore, accumulated and was actually stored on the field
16
-------
surface and in the drainage ditches. The flooded conditions
that developed led to odor and mosquito propagation problems
The crop was allowed to grow throughout the season and
became quite tall. This tall grass impeded drying of the
soil surface and produced sheltered habitat for mosquito
breeding.
The flooded condition was partially relieved in 1973 by the
addition of 75 acres of spray field and regrading the
existing 90 acres. The resulting loading rate was 0.67 in./
day. In addition, the cover crop was harvested as part of
the field management. Prior to harvesting, the field was
allowed to dry for a period of 7 days. The grass was mowed
and removed as green chop in one cutting during the 1973
season. For 1974, the expected flow is 2 mgd as a result
of the separation of cooling water and the resulting appli-
cation rate would be reduced to 0.45 in./day.
Tower Spray Irrigation - A unique spraying system has
evolved at the Stokeley-Van Camp installation at Fairmont,
Minnesota. In the early 1950s a portable solid-set system
was used, but the labor required to move the laterals
proved too expensive. This system was replaced by a boom-
type center pivot irrigation rig which also was too
demanding of labor for maintenance. Finally, a fixed tower
system was designed with fog nozzles operating at high
pressure. The system now operates successfully using towers
at 500-foot centers that are about 25-feet high(H).
Flood Irrigation - The California Canners and Growers in-
stallation at Thornton, California, previously described
under spray irrigation, is also a good example of surface
irrigation systems because border strip flood irrigation
is employed both with and without cover crops. The vege-
tated section consists of 60 acres planted to water grass.
The wastewater is distributed onto the strips by means of
gated aluminum pipe. This distribution system is coupled
to and operates in rotation with the high pressure spray
system. Prior to the expansion in 1973, wastewater was
applied to this section for 4 to 6 hours each day without
any resting periods. The cover crop was not harvested.
Inadequate land leveling in the area resulted in ponding
and along with the tall grass contributed to the mosquito
problems previously described.
In 1973 the treatment system was expanded to include 150
acres of nonvegetated flood irrigation strips. Each strip
is 60 feet wide and up to 1,500 feet long. The wastewater
distribution system consists of a combination of gated
aluminum pipe and concrete-lined ditches with slide gates.
Wastewater is applied to several strips (2 to 4) until flow
17
-------
reaches the end of the strip. The only significant operating
problem encountered was erosion along the borders and, even-
tually, standing water at those points. This problem could
be avoided by forming the borders using dike construction
methods rather than the ridging method commercially used in
agriculture. The runoff is collected in a tailwater return
system and pumped back to the distribution ditch. The first
operating season was too short to establish equilibrium
application rates. However, with the expanded system the
average application rate for the entire system was reduced
to about 0.35 inches per day.
A second example of flood irrigation is the Idaho Fresh Pak
system at Lewisville, Idaho. The land has been graded into
2.5-acre plots for border strip irrigation. Potato-peel
wastewater passes through a vacuum filter and the filtrate
is pumped 4.5 miles to the site. In the summer, grass is
grown and harvested for hay. In the winter the 50 deg F
wastewater melts the snow and ice and percolates into the
soil. Some odors exist and more land is being acquired by
the company.
The Libby's cannery in Gridley, California, is beginning
construction of a nonvegetated surface irrigation system to
treat peach and pumpkin processing wastewaters. Border strip
flood irrigation without crops was selected to eliminate the
need for settling prior to application and to guard filtering
out settleable material by the cover crop at the head end of
the irrigation strips. Wastewater will be pumped from the
plant to the irrigation site located about 4 miles to the
south. Prior to pumping, the wastewater will pass through
coarse screens and a grit removal chamber. Grit removal
is considered necessary to prevent deposition in the con-
veyance force mains. Application of the wastewater will be
managed to provide drying of the soil surface within 24 hours
of application to prevent mosquito propagation.
Ridge and Furrow Irrigation - This form of irrigation has
been replaced, for the most part, by spray irrigation. Where-
as SchraufnagelC16) reported about 50 ridge and furrow systems
in 1962, Sullivan(H) reported only one ridge and furrow
system out of the 56 responding to the APWA questionnaire.
That system was the Green Giant Company installation at Buhl,
Idaho, where corn-processing wastewater is screened and used
as supplemental irrigation water for corn. In addition to
the systems listed in Table 4, other systems reported in
existence by an APWA mail survey are five creameries in
Wisconsin and three food processing plants in Indiana.
18
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Overland Flow Systems
The overland flow systems described below are examples of
how the system may be adapted to different site conditions.
A list of existing systems with operating characteristics is
presented in Table 5.
Table 5. Selected Overland Flow Systems
Location
Average
Avg Field application
flow, area, rate,
mgd acres in./day Soil type
Hunt-Wesson Foods
Davis, California 3.25
Campbell Soup Co.
Chestertown,
Maryland 0.7
Campbell Soup Co.
Napoleon, Ohio 4.0
Campbell Soup Co.
Paris, Texas 3.5
250
70
335
385
0.5
0.4
0.35
Clay loam
Clay
0.45 Silty clay
Clay loam
The Hunt-Wesson Foods cannery in Davis, California, employs
the overland flow technique to treat approximately 3.25 mgd
of tomato processing wastewater from July through September,
plus smaller volumes of wastewater from other products during
the remainder of the year. The system consists of a series
of sloped terraces with collection ditches at the toe of
each slope. The terraces were constructed on a slope of 2.4
percent with a length of 175 feet. A considerable amount of
earthwork was required to form the slopes (over 300,000
cu yd) since the site was originally flat agricultural land.
The slopes were planted to a combination of Reed canary grass,
tall fescue, Italian rye grass, and trefoil with the anti-
cipation that Reed canary grass would eventually dominate.
The distribution system consists of a solid set sprinkler
system with risers spaced at 100-foot intervals and 65 feet
from the top of each slope.
Spraying is preceeded by coarse screening. The application
of wastewater is controlled automatically by clock timers
that actuate pneumatic valves in the field. During peak
season, however, the spray rotation is controlled manually
19
-------
with an effort to minimize runoff. The runoff, which amounted
to about 10 percent of the applied flow during the 1973
season, is collected and conveyed to an effluent pumping
station for discharge to receiving waters. Treatment effi-
ciency in terms of BOD removal is excellent. A raw waste
BOD ranging from 400 to 800 mg/1 is reduced to less than
12 mg/1 by the season's end.
The cover crop is harvested once each year in late April or
early May. Since the operation is seasonal, additional
cuttings are not warranted. The yield of hay is approximately
1.6 ton/acre.
The overland flow system at the Campbell Soup Company plant
in Parisj Texas, is the most thoroughly studied of the
existing systems(12). This site was originally severely
eroded sloping land that was reshaped into a network of
sloping terraces with widths ranging from 200 to 300 feet
and grades ranging from 1 to 12 percent. Subsequent studies
revealed the optimum slope grade to range from 2 to 6 per-
cent (13). Wastewater is applied at the approximate rate
of 0.1 in./hr to the upper portion of a slope for 6 to 8
hours continuously, followed by a resting period of twice
the application time. Runoff is collected and discharged
to a natural waterway. Approximately 60 percent of the
water appears as runoff. The quality of runoff has been
consistently excellent as evidenced by the removal efficien-
cies shown in Table 6.
Table 6. Removal Efficiencies
for Overland Flow at Paris, Texas
Influent, Effluent, Removal,
Parameter
BOD
Suspended solids
Total nitrogen
Total phosphorus
mg/1
490.0
245.0
19.0
8.5
mg/1
8.0
24.0
3.0
4.0
%a
98
90
85
55
a. Based on concentrations.
20
-------
The cover crop management consists of harvesting two or
three times beginning in the spring. Yields are in the
range of 3.5 to 4 tons/acre.
Infiltration-Percolation Systems
Under the category of infiltration-percolation, two methods
of wastewater application are employed. These are spreading
basins or percolation beds and high rate spraying. A
selected list of existing installations is presented in
Table 7. Examples of systems employing the two application
techniques are described below.
Table 7. Selected Infiltration-Percolation Systems
Average
Avg application
Method of flow, rate,
Location application mgd in./day Soil type
Tri Valley Growers
Modesto, California
Hunt-Wesson Foods
Bridgeton, New Jersey
H.J. Heiz Co.
Salem, New Jersey
Seabrook Farms
Seabrook, New Jersey
Campbell Soup Co.a
Sumter, South Carolina
Yakima, Washington
Flood
Spray
Spray
Spray
Spray
Spray
2.5
3.0
1.3
14
3.5
4.0
1
2
1
8
0
1
.5
.5
.6
.0
.9
.2
Sand
Sand
Sandy
Sand
Sand
Sandy
silt
loam
a. System is underdrained at a depth of 5 feet.
Tri Valley Growers' Plant No. 2 near Modesto, California,
is one of the few processing plants where classical spreading
basins are employed for infiltration-percolation. A waste-
flow of approximately 2.5 mgd is generated from the pro-
cessing of tomatoes, peaches, and pears with the canning
season normally extending from July through September. The
infiltration-percolation site consists of 70 acres of
spreading basins and 20 acres of wine grapes. The grapes
21
-------
are irrigated with wastewater using normal application rates
with no adverse effects on grape quality. The soil at the
site is primarily sand and loamy sand.
The infiltration-percolation site is divided into one-acre
basins. Most of the basins receive wastewater from concrete-
lined ditches equipped with slide gates, while the remainder
are served by a buried-pipe system with flood valves. This
pipe must be flushed with fresh water after each application
to prevent release of odors. The application schedule and
loading rates have been developed by trial and error, since
each basin was found to have a different percolation capacity,
The differences are due to hardpan layers in the subsoil.
This situation is a good example of why subsurface soil con-
ditions should be determined as part of a site investigation
for infiltration-percolation systems. Applications range
from 50,000 to 500,000 gallons per acre depending on the
basin. Each application is followed by 7 to 10 days of
resting. The applications are regulated to achieve elimina-
tion of standing water within 24 hours of the start of
application. This avoids both odor and mosquito problems.
During the summer no cover crop is used on the basins.
After each application the basins are disked to allow the
soil to aerate and maintain its infiltrative capacity. As
the season proceeds, the infiltrative capacity drops somewhat
due to clogging by solids in the wastewater. Following the
canning season, the basins are planted to oats which are
harvested in the following spring. The oats serve to take
up some of the nitrogen that was contained in the wastewater
and held in the soil structure, as well as to restore the
infiltration capacity of the soil.
Research on the system's long term effect on the groundwater
is being sponsored by Tri Valley Growers and conducted by
the University of California Agricultural Extension Service.
Permanent soil sampling stations have been established at
several locations that allow extraction of water samples
from various depths.
As mentioned previously, the infiltration-percolation
system using high-rate spraying at Seabvook Farms has been
in continuous operation since 1950. In each of the three
New Jersey systems listed in Table 7, the soils are very
permeable and the vegetation that survives the high-liquid
loadings is totally wild. At Seabrook Farms in 1950 the
site was wooded with oaks, cedars, ironwood, gum, and dog-
wood trees(6). As a result of the high-rate spraying the
22
-------
dominant form of vegetation is now marsh grass. The areas
that have proven to be permeable now receive as much as
12 in./day over a 12-hour period.
COSTS
At present the availability of useful cost data on land
treatment systems is limited, but efforts are underway at
Metcalf § Eddy to develop a cost reference through a
contract with the EPA. The cost data presented herein are
based primarily on the APWA report(H) and are supplemented
with information on a few systems in California.
Spray Irrigation
Costs for selected spray irrigation systems are given in
Table 8. Construction costs include costs for pumping
stations, force mains, land preparation, and distribution
systems, except as noted, and depend on the year con-
structed as well as many local conditions. Land costs have
been separated because of their variability and are pre-
sented in Table 9. In addition to the cost of land when
purchased, the estimated value of the land in 1972 is in-
cluded in Table 9. In all cases the value of the land is
at least as high as when it was purchased and in several
cases land values have appreciated substantially. The total
capital cost is the sum of the costs for land and construction
plus easements, pretreatment facilities, monitoring facili-
ties, and administrative, engineering, and legal fees. In
the case of the Libby operation at Liepsic, Ohio, the land
for spray irrigation is leased.
Operating costs are also given in Table 8. The annual
budget was divided by the total annual flow to obtain the
cost in cents per thousand gallons. The period of operation
ranged from 4 months for the Green Giant Company operation
at Montgomery, Minnesota, to 12 months for the Gerber
operation at Fremont, Michigan(H) .
Surface Irrigation
Costs for surface irrigation depend a great deal on the
existing topography. Consequently the cost of preparing
the land for irrigation must be balanced against the pur-
chase price of the land. For example, the Libby's system
at Gridley did not entail any land preparation costs
because the fields were leveled previously for irrigation.
However, the land cost was $1,400 per acre. On the other
hand, for the California Canners and Growers system at
Thornton, costs for land preparation and the distribution
23
-------
Table 8. Construction and Operating
Costs for Selected Spray Irrigation Systems
Location
Sebastopol Coop
Sebastopol, California
Western Farmers Assoc.
Aberdeen, Idaho
Idaho Supreme Potato Co.
Firth, Idaho
Gerber Products Co.
Fremont, Michigan
Stokely-Van Camp
Fairmont, Minnesota
Green Giant Co.
Montgomery, Minnesota
Libby, McNeill 8 Libby
Liepsic, Ohio
Lamb-Weston
Connell, Washington
Cobb Canning Co.
Cobb, Wisconsin
AVQ — —
Construction cost Operating cost
AVg
flow,
mgd Cost, $
0.3 88
(34
0.5 95
0.6 64
0.8 75
1.5 100
1.2 72
0.7 45
1.6 210
50
0.2 8
,100b
,700)c
,ooob
,000b
,000
,000
,000
,000
,000
,000
,500
Year
made
1972
1971
1969
1953
1965-
1972
1949
1972
1971
1972
1960
Cost
$/gpd
0
0
0
0
0
0
0
0
0
0
.29b
.19
.10
.09
.07
.06
.06
.13
.03
.04
Cost Annual
$/acre cost, $ f/1,000 gal?
l,630b 3,400
(640)c
1,050 25,000
800
830 65,000
250 23,000d
200 28,000
350 SO.OOO6
800 179,000
190
390 3,000
7.1
18.2
22.3
7.2
23.3
31.1
30.0
12.4
a. Depends upon period of operation.
b. Total cost includes pretreatment, transmission, land preparation, and distribution
but excludes land costs.
c. Distribution and land preparation only.
d. Total cost not including return from sale of crops.
e. Includes $17,000 annual lease but not return from sale of crops.
Table 9. Land Costs for Selected Spray Irrigation Systems
Land
area,
Location acres
Sebastopol Coop
Sebastopol, California 54
Western Farmers Assoc.
Aberdeen, Idaho 90
Idaho Supreme Potato Co.
Firth, Idaho 80
Green Giant Co.
Belvidere, Illinois 160
Duffy-Mott Co.
Hartford, Michigan 40
Lamb-Weston
Connell, Washington 265
American Stores Dairy Co.
Fairwater, Wisconsin 200
Libby, McNeill 5 Libby
Janesville, Wisconsin 50
Year
purchased
1972
1971
1969
1960
1967-8
1970
1942
1952
Estimated
value
Cost, in 1972,
$/acre $/acre
800
450
600-800
600
600
225
110
250
800
450
800
5,000
1,000
650
400
1,500
24
-------
system totalled $450 per acre (total construction cost shown
in Table 10). Adding this to the land cost of $870 per acre
yields a total of $1,320 per acre at Thornton, as compared
to the $1,400 per acre at Gridley. Of course, many of the
local conditions were different. However, the combination
of land cost and land preparation cost is an especially im-
portant consideration for surface irrigation systems. Addi-
tional land costs are given in Table 11.
Table 10. Construction and Operating Costs
for Selected Surface Irrigation Systems
Location
Avg
flow,
mgd
Construction cost
Cost, $
Year
made
Cost,
$/gpd
Cost,
$/acre
Operating cost
Annual
cost, $
-------
Ovenrland Flow
Construction cost items for overland flow include earthwork,
pretreatment, transmission, distribution, and collection(6).
Clearing of land, grading of slopes, and planting is gener-
ally equal in cost to the distribution system. The available
costs for distribution systems and land preparation for two
operating systems are given in Table 12. The operating costs
shown are total costs not including the return from the sale
of hay. The return on the sale of hay is approximately 8 to
10 percent of the total annual operating cost.
Table 12. Construction and Operating
Costs for Overland Flow Systems(6)
Average
flow, Construction Operating cost,
Location mgd cost, $/acre tf/1,000 gal.
Hunt-Wesson Foods
Davis, California 3.25 1,500 5-10
Campbell Soup Co. ,
Paris, Texas 3.5 1,006 5
a. 3-month operating season, constructed in 1971.
b. Year-round operation, constructed in 196.4-1965.
Infiltration-Pereolation
For infiltration-percolation systems, the costs per gpd, as
shown in Table 13, are relatively low compared to spray
irrigation. Similarly, the operating costs are lower due
also to the high-rate applications and low land requirements.
The only available land cost was $400 per acre in 1961 for
the Hunt-Wesson system at Bridgeton, New Jersey.
26
-------
Table 13. Construction and Operating Costs
for Selected Infiltration-Percolation Systems
Location
Construction cost
Average Operating
flow, Year Cost, Cost, cost
mgd made $/gpd $/acre 4/1,000 gal.
Hunt-Wesson Foods 3.0
Bridgeton, New Jersey
H.J. Heinz Co. 1.3
Salem, New Jersey
Seabrook Farms 14
Seabrook, New Jersey
Yakima, Washington 4.0
1961 0.08
1955
1970
1972
1950
0.077
0.038
0.031
5,460
3,340
1,670
1,330
1964 0.027 1,500
3.6
4.8
a. Depends upon the period of operation.
APPLICABILITY AND POTENTIAL OF LAND APPLICATION
It is apparent from the descriptions of the various existing
systems that land application can be adapted to a wide range
of soil types and site drainage conditions. One of the keys
to a successful system is to determine the site character-
istics—soil type, soil drainage, subsurface conditions,
topography, and climatic conditions--and then adapt the most
suitable technique to them. Equally important to successful
operation is conscientious field management to avoid stressing
or overloading the system.
Of particular interest to the food processing industry is
the ability of land application techniques to meet "zero
discharge" requirements at a reasonable cost. As more food
processing activity becomes centered in rural areas the
economic advantages of land application will become more
evident.
Land application, however, is not a panacea. Many uncer-
tainties still remain regarding long-term effects of waste-
water on soils, plants, and groundwater. Research in this
regard is being carried on at several locations. Dr. Jay
Smith of the USDA in Kimberly, Idaho, is conducting a 3-year
study of land application of potato processing wastewaters in
Idaho. EPA has sponsored considerable research on overland
flow with some findings to be discussed later in the
27
-------
conference. As mentioned previously under infiltration-
percolation, the California Agricultural Extension Service
is conducting a study on the treatment efficiency at Tri
Valley Growers Plant No. 2 and the results will be published
this summer in California Agriculture.
The food processing industry has taken the lead in developing
land application as an economic alternative to conventional
treatment methods. This is evidenced by the fact that over
one-third of all the land application systems in the United
States serve the industry. Active interest, such as the
research efforts mentioned above, indicates that the in-
dustry will continue to be at the forefront of future
development.
28
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REFERENCES
1. BOLTON, P. Disposal of Canning Plant Wastes by
Irrigation. Proceedings of the 3rd Industrial
Waste Conference. Lafayette, Purdue University.
pp 272-281 (1947).
2. COAST LABORATORIES. Grape Stillage Disposal by
Intermittent Irrigation. Prepared for the Wine Insti-
tute, San Francisco (June 1947).
3. WATER RESOURCES ENGINEERS, INC. Cannery Waste Treat-
ment, Utilization and Disposal. California State
Water Resources Control Board Publication No. 39 (1968),
4. DRAKE, J.A., AND BIERI, F.K. Disposal of Liquid Wastes
by the Irrigation Method at Vegetable Canning Plants in
Minnesota; 1948-1950. Proceedings of the 6th Indust-
rial Waste Conference. Lafayette, Purdue University.
pp 70-79 (1951).
5. MATHER, J.R. The Disposal of Industrial Effluent by
Woods Irrigation. Proceedings of the 8th Industrial
Waste Conference. Lafayette, Purdue University. pp
439-353 (1953).
6. POUND, C.E. and CRITES, R.W. Wastewater Treatment and
Reuse by Land Application - Vol. II. Office of Re-
search and Development, Environmental Protection Agency
(August 1973) .
7. LUDWIG, H. ET AL. Disposal of Citrus Byproducts Wastes
at Ontario, California. Sewage and Industrial Wastes
23: 1255 (1951).
8. PORGES, R. and HOPKINS, G. Broad Field Disposal of
Sugar Beet Wastes. Sewage and Industrial Wastes 27:
1160 (1955).
9. BELL, J.W. Spray Irrigation of Poultry and Canning
Wastes. Public Works 86: 111 (1955).
10. HILL, R.D., BENDIXEN, T.W. and ROBECK, G.G. Status
of Land Treatment for Liquid Waste--Functional Design.
Presented at the Water Pollution Control Federation
Conference, Bal Harbour, Florida (October 1964).
29
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11. SULLIVAN, R.H. ET AL. Survey of Facilities using
Land Application of Wastewater. Office of Water Pro-
gram Operations. Environmental Protection Agency
(July 1973).
12. GILDE, L.C. Food Processing Waste Treatment by Surface
Filtration. Proceedings of the First National Sympo-
sium on Food Processing Wastes. Portland, Oregon.
pp 311-326 (April 1970).
13. C.W. THORNTHWAITE ASSOCIATES. An Evaluation of Cannery
Waste Disposal by Overland Flow Spray Irrigation.
Publications in Climatology, Vol. 22 (September 1969).
14. THOMAS, R.E. Spray-Runoff to Treat Raw Domestic Waste-
water. Presented at the International Conference on
Land for Waste Management. Ottawa, Canada (October 1973)
15. BLOSSER, R.O. and OWENS, E.L. Irrigation and Land
Disposal of Pulp Mill Effluents. Water and Sewage
Works, 111: 424 (1964).
16. SCHRAUFNAGEL, F.H. Ridge-and-Furrow Irrigation for
Industrial Wastes Disposal. Journal WPCF 34: 1117
(1962) .
30
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USE OF A MUNICIPAL PERMIT PROGRAM FOR
ESTABLISHING FAIR WASTEWATER SERVICE CHARGES
by
RODNEY T. WILLIAMS*
INTRODUCTION
Historically, permit programs have served public wastewater agencies as a
means of enforcing regulations. Permits have been issued to ensure com-
pliance with structural standards and as a means of keeping a record of
the sewer connections from private property to the public sewer system.
More recently, permits have been issued to insure user compliance with
standards established in industrial waste ordinances.
The newly increased emphasis on permit programs by municipal agencies is
a direct result of Federal Regulations;in particular, the national permit
system created by the Water Pollution Control Act Amendment of 1972(1).
This permit program for the first time, is a national permit program that
is applicable to municipal sewers. The terms and conditions of these per-
mits now being issued to municipal agencies often contain requirements for
industrial users such as effluent limitations, monitoring and reporting
the industrial users. Previously many states had permit programs and the
federal government, through the U. S. Army Corps of Engineers, had issued
some permits for discharges under the 1899 Refuse Act. The previous fed-
eral programs only affected about 20,000 industrial discharges. New fed-
eral regulations such as the provisions of Industrial Cost Recovery(2)
from industrial waste users and the enforcing of pretreatment standards
will affect more than 100,000 industrial users of municipal systems.
These new requirements, will result in municipal agencies across the coun-
try adopting permit programs to enforce pretreatment standards and source
control regulations. These federal requirements also offer an opportunity
to the municipal agency to adopt a permit program that can be used to equit-
ably recover revenue.
Historical Perspective
Special District No. 1 of the East Bay Municipal Utility District was
created in 1944 to treat and dispose of the sanitary sewage and industrial
wastes from the cities of Oakland, Berkeley, Alameda, Albany, Piedmont and
Emeryville in Alameda County in California. Presently, the District also
0
* Rodney T. Williams is a Senior Sanitary Engineer with the East Bay Muni-
cipal Utility District in Oakland.
31
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serves the Contra Costa County cities of El Cerrito, Kensington and parts
of Richmond. The population at the 1970 census was 618,000 and the geo-
graphical area is 83 square miles. The total number of sewer connections
or "users" as they are referred to is about 167,000. Of particular interest
is the large number of industries that discharge wastewater. Using a com-
monly accepted definition of industry as all processing and manufacturing
operations, there are approximately 1,000 separate industrial users.
When one considers industrial users as defined in the Industrial Cost R.e-
covery Regulations(2) this number rises to 2,000. Within these regulations
an "industrial user" has been defined as "any non-governmental user of
publicly-owned treatment works identified in the Standard Industrial Class-
ification Manual, 1972, Office of Management and Budget(3), as amended and
supplemented under the following divisions: (a) Division A, agriculture,
forestry and fishing; (b) Division B, mining; (c) Division C, manufactur-
ing; (d) Division E, transportation communications, electric, gas, and san-
itary services; (e) Division I, services. A user in the Divisions listed
may be excluded if it is determined that it will introduce primarily seg-
regated domestic wastes or wastes from sanitary conveniences."
Within Special District No. 1 there are 114 known users with over 200 con-
nections to the sewer system that have been categorized within the food
processing division (major division SIC 2000, Food Processing). The food
processing division is interesting because it provides an example of a cat-
egory of users where there is little need to enforce a source control program
in a large municipal system. The pollutants discharged are regarded as
"compatible" with the sewage treatment plant because they can be adequately
described in terms of the treatable constituents of suspended solids and
biochemical oxygen demand. Table I (Food Processing Industries within Spec-
ial District No. 1) shows a listing of the industrial categories within the
food processing division and the number of industries in the District within
each category. The table (Table I) indicates that most of the industry's within
the food processing division have small wastewater volume. The number of
"major contributory industries" shows this fact. (A major contri-
butory industry has been defined by the Environmental Protection Agency as
primarily one that discharges more than 50,000 gallons of wastewater on an
average work day or has a flow greater than 5 percent of the flow carried
by the municipal system receiving the waste.) Pretreatment standards are
applicable to these larger industries if they are discharging incompatible
pollutants.
Within most public agencies, significant portions of the compatible pollu-
tants of suspended solids and biochemical oxygen demand will be removed in the
treatment process. Consequently pretreatment by food processing industries will
not be required. However, the municipal agency must still adopt an equit-
able system of cost recovery. (In the case of a large industry in relation
to a small treatment plant, the agency would be required to enforce some
source control to prevent the discharger causing an overload or upset of
the treatment process.)
Rates and Charges
The revenue requirements of Special District No. 1 are derived from a combin-
ation of use charges and taxes. Those costs allocable to the excess
32
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capacity provided for future growth and to the treatment and disposal of
stormwater and infiltrated ground and surface water are obtained from ad
valorem taxes: all other costs are paid from use charges. Until 1973,
the use charge was based solely on volume of wastewater discharged. Table
II (Unit Rates Within Special District No. 1) shows the present unit rates
for volume and wastewater strength.
Charges on "Quality and Volume" vs. "Surcharges"
In collecting charges from users, the District had to squarely confront
the question of equity. The literature and the Federal Revenue Guide-
lines (2) suggest either charges based on volume and quality, or surcharges
as being equitable.
Table I provides an insight into the reason for selection of a rate sched-
ule on quality and volume. Of the 114 users in the food processing cate-
gory only 26, or less than 23% of the industries are major contributing
industries. Past laboratory test results had concluded that the relatively
high loading experienced at the treatment plant (suspended solids, 270 mg/1
and BOD, 285 mg/1) was due almost entirely to the smaller users. The intro-
duction of a surcharge ordinance would necessitate the sampling and monitor-
ing of a large number of discharges at great expense. Moreover, if the sur-
charge rate schedule ignored the smaller industries, the rate schedule would
have been useless because of the relatively weak strength of most of the
large industries. An attempt to enforce a surcharge rate schedule on just
large industries would be discriminatory and worst of all, would not provide
the equity which had been a fundamental goal. The solution was to group
smaller industries by their type of operation. A comprehensive sampling and
testing program prior to the establishment of the rates had shown that indus-
tries within any one category had similar waste strength characteristics.
Table III (Strength Values for Food Processing Industry) lists the average
waste strength for various industrial categories within the food processing
division of the S.I.C. During the six month period prior to the establish-
ment of the rates, more than 7,000 laboratory tests were made to determine
the characteristics of the wastewater for industries within Special District
No. 1.
Consequently, in addition to the inclusion of unit rates for each parameter
in the District's schedule of rates and charges, a charge was adopted for
each user category that reflected the average wastewater strength for that
category (See Table IV, Charges for Smaller Industries). The charges for
the larger users would be determined on a case-by-case basis under a permit
program.
PERMIT PROGRAM
The District's Wastewater Control Ordinance(7) effective January 1, 1973,
established a mandatory permit program. One criteria for a mandatory per-
mit depends on the types of pollutants discharged and is applicable to in-
dustries discharging "incompatible"(5) pollutants. The second criteria is
the size of the discharge. The criteria is applicable to the food proces-
sing industry and is based on economic considerations. This criteria was
chosen from an evaluation of the probable variation in an industry's waste-
water strength parameters and the size of the discharge. Mandatory permits
based on the size of the discharge are issued permits to all large industries,
33
-------
discharging more than 1,100,000 gallons in any month (37,000 gallons/day).
This volume represents an average sewage bill of $150/month. For this
size bill, a self-monitoring program is economically justifiable. These
permits are then issued for the purpose of establishing equitable rates.
Charges for permittees are based on a wastewater strength established in
the permit and the unit rates for the wastewater quality parameters (See
Table II, Unit Rates Within Special District No. 1). These strength
values are compared with past District sampling before approval of the
permit and are subsequently verified through a self-monitoring program.
(Appendix II, Self-Monitoring Report).
For the first permit of a customer, the charges are computed using an
estimated annual average wastewater strength. These estimates are made
at the industry's discretion and are usually based on a flow composite
sample taken over a normal working day or a normal working week.
These estimates are reviewed and if acceptable, become the basis for bill-
ing. Their applicability are verified through a self-monitoring program
undertaken by the customer and through a District sampling program.
Monitoring Program
The District, having determined at what size sewer bill it would be econo-
mic to individually establish the strength, then investigate the criteria
for establishing a sampling frequency.
Because the purpose of the permit program is for the establishment of equit-
able charges, detailed consideration has been given to the frequency of
sampling by the industry. Inequities in the cost recovery system are es-
sentially the difference between the amount of sewage service charge t>aid on
the estimated wastewater strength and the amount that would be paid if the charge
was based on the actual wastewater strength.
Any sampling frequency must seek to strike a balance between the cost of
the sampling program and the inequities in the sewage charges. Table V
(Sampling Frequency for Industrial Discharges) shows the sampling frequency
established for industries within Special District No. 1. The sampling fre-
quency has been directly related to the size of the sewage service charge
and the variation in flow rate. The emperical relationship between these
two variables has been derived considering the size of industries within
Special District and the present costs of sampling and testing. All samples
are required to be flow-proportional samples taken over a normal working day.
(For very large industries or industries where there is high flow rate, the
samples are required to be composited in proportion to the flow at the time
of sampling using an automatic sampler.)
The establishment of sampling frequency on Special District No. 1 differs
in two ways from the common practices of most other municipalities. These
sampling frequencies are either based on a fixed time interval (e.g. one
per month, one per week) without consideration given to the size of the
discharger or in the more developed programs, such as of New York and Los
Angeles County Sanitation District, are based on rate of flow. Special Dis-
trict No. 1, in recognizing that the prime purpose for a self-monitoring pro-
gram in the food processing industry is for establishing equitable rates and
34
-------
charges has included the projected sewer service charges as a factor in deter-
mining sampling frequency. The sampling frequency is related to the in-
dustry's maximum sewer service charges. Where the industry is truly
seasonal, variations in sampling frequency are established to fit the
seasonal operation. Table VI (Comparison of Sampling Frequencies), com-
pares the sampling frequency used by Special District No. 1 with that
recommended by the New York State Department of Public Health(6) and
that used by the Los Angeles County Sanitation Districts. Two unit
charges have been assumed for industries within Special District No. 1
to facilitate comparison of sampling frequencies.
With each sample collected as part of the self-monitoring program, a test
is required on each parameter which is the basis of the sewage service
charges. At present, this includes those parameters listed in Table II
(Unit Rates Within Special District No. 1). On completion of the secon-
dary treatment construction, a charge on filtered chemical oxygen demand
is anticipated. Chemical oxygen demand is considered more useful when
attempting to establish charges on non-organic wastes and organic wastes
that contain substances toxic to biological tests. The use of filtered
chemical oxygen demand will be an attempt not to charge for the same sub-
stances or constituents twice.
These parameters, namely suspended solids and filtered chemical oxygen
demand will be considered "compatible" with the treatment process and
consequently no pretreatment for these parameters will be required. In-
dustries within the food processing division will be able to discharge
these wastes without pretreatment, provided the wastes are adequately
screened and that oil and grease(4) concentrations of vegetables origin
do not interfere with the conveyance or treatment processes.
Pretreatment will be required of wastes that are "incompatible" or are
not amenable to adequate treatment by biological systems. These wastes
may contain either constituents that pass through, or may interfere with
the treatment capability of the biological system. These incompatible
pollutants, many of which have been specifically listed in the Wastewater
Control Ordinance(7) will be tested on each sample for those industries
where a violation could occur. The actual testing frequency in relation
to the number of samples is based on a consideration of the average and
maximum wastewater strengths of the "incompatible pollutants".(5)
Administration and Operating Costs of the Program
The method of computing rates based on the quality and quantity of waste-
water strength have already been discussed. For small industries where
self-monitoring would be costly, the rates are established on an industry
average. Provision is made for small industries who want to monitor and
test their waste and for permittee industries to tailormake rates by use
of the permit program. To date, under the permit program, charges have
ranged from 9
-------
directly from the permittee by a charge against his self-monitoring
report and a charge against each test required. These charges are
presently $5.00 per sample and $1.50 per test required under the
terms and conditions of the permit. These charges are based on sam-
ple checks averaging once for every four samples taken by the per-
mittee.
To recover the costs of administering the program, the District levies
a permit fee. For users who have their sewage service charge based on
a strength determination or on an estimate of the wastewater volume,
the charge is $100/permit. For users who require both flow and strength
determination, the charge is $175. All permits must be renewed annually.
At present, the unit rates recorded in Table II (Unit Rates Within Spec-
ial District No. 1) are based on the revenue requirements of the District.
These revenue requirements are made up of annual capital expenses(which
include bond repayments) and operating and maintenance costs. Any changes
in these costs or in the amount of volume or quality parameter being dis-
charged to the system can easily be evaluated and if necessary a new unit
rate adopted. These new rates would then become the basis for the user
category charges and the permit charges.
Industrial Cost Recovery
At the completion of construction of municipal treatment plants that now
receive federal funds, each agency must undertake to collect from indus-
trial users their share of the federal grant money(2).
For Special District No. 1 approximately 2,000 users will fall into the
category of having to contribute revenue to meet this provision of the
law. Using the quality and quantity procedure described previously,
these incremental revenues can be allocated to each parameter. A separate
parameter rate for the industrial user can be developed that will include
their share of the Federal Grant. These industrial unit rates become the
basis for charging industries in the various user categories and in the
permit program.
The real question, however, is can any equitable rate system be developed
within the provision of the law? Any discussion of this matter must final-
ly depend on one's own prejudice of equity and would be incomplete without
considering the flow of money in the economy and taxing policies. Obvious-
ly, these questions are too grandiose for this discussion but it is worth
while to examine three possible options.
1. Agency Charges Industry Additional Amounts to Meet Federal Payback
Provision — The municipal agency recovers its annual capital re-
quirements and then obtains, through a charge to industry, their
share of the federal grant.
2. Agency Charges All Users 50% of the Depreciation on the Federal
Grant and Industrial Users 100% of the Depreciation on the Federal
Grant — Municipal agency recovers its annual capital requirement
in 3 parts: Bond money and interest requirements are computed.
36
-------
Fifty percent of the Federal Grant is recovered from all users
or a larger amount if necessary to cover the annual capital
and replacement expenditures of the agency; an additional
amount is computed for industry to cover their share of the
Federal grant.
3. Both Industry and Non-Industry Contribute Revenue in Proportion
to Their Wastewater Load — The same revenue is collected from
all users but is at least 75% of the depreciation on the grant
funded facilities in order that industry contributes their full
share of the federal grant. (This approach is mandated in Cal-
ifornia except that the California Water Resources Control Board
has specified a minimum of 100% of the depreciation over a ser-
vice life not to exceed 30 years.)
From Table VII (Comparison of Revenue From Industry Under Various Receipt
Formulae) the advantages and disadvantages of these three cases are easily
discerned.
Case I
This is probably the simplest to develop in that a satisfactory exist-
ing method of calculating rates would remain unchanged with additional
amounts to meet the Industrial Cost Recovery Provision collected from
industry as a separate item.
Case II
The amounts of revenue remaining for the municipalities' use after re-
turning 50% of the industries's share of the federal grant contains
amounts from industry and non-industry in proportion to the wastewater
load.
Case III
Both industry and non-industry contribute in proportion to their load
on the treatment plant. However, the monies remaining for use by the
municipality is 13.5% industry money compared with 20% industry load
on the treatment plant.
In all three cases, after meeting the Industrial Cost Recovery requirements
the municipality is receiving more money than its annual revenue needs.
Under Federal Law, 80% of the retained amount must be used for expansion and
reconstruction of the facility. For a few agencies, the annual revenue re-
quirements would exceed the depreciated capital over the 30 years. One point
that this table clearly makes in its most general form is the impossibility
of being able to collect money in proportion to load and have money in the
municipalities' fund for plant replacement and improvements in proportion to
load.
CONCLUSION
A municipal permit program can be a powerful tool not only for the tradi-
tional enforcement aspects of municipal industrial waste programs but as a
37
-------
means of equitably recovering charges from users. The charges associated
with sampling the larger industries have been made directly against the
self-monitoring program of the permittee. In establishing the frequency
of the self-monitoring program, consideration has been given to the size
of the discharge, the variation in discharge, as well as the amount of con-
stituents in the waste stream.
Unless the municipal check-up program indicates, the required tests in
the food processing industry are for compatible pollutants only.
Of great importance is the flexibility possible in establishing charges
on an individual user basis through a permit program. This flexibility is
of utmost importance as agencies face the problem of establishing charges
and accounting for revenues associated with the Industrial Cost Recovery
provision of the Federal Water Pollution Control Act Amendments. These
amounts for industries can be included on a special rate structure or as
part of a special permit charge.
The Industrial Cost Recovery provision in its present form, may be possible
to administer as detailed in this paper, but lacks a logical explanation,
especially under a concept of equity which the Act sets out to provide. Con-
sequently, this provision of the Act should be repealed and replaced by a
condition that the public wastewater agency have a program of self-suffi-
ciency and that it have an approved revenue program that proves the agency
is collecting rates equitably.
38
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REFERENCES
1. PL 92-500, "Federal Water Pollution Control Act Amendments," October
18, 1972.
2. "Industrial Cost Recovery," CFR Title 40, Chapter 1, Sub-Chapter B,
Part 35.
3. Executive Office of the President: Office of Management and Budget,
Standard Industrial Classification Manual, U. S. Government Printing
Office, 1972
4. Standard Methods for the Examination of Water and Wastewater, APHA,
AWWA, WPCF, 13th Edition, 1971.
5. "Pretreatment Standards," CFR, Title 40, Chapter 1, Sub-Chapter D,
Part 128.18.
6. Industrial Waste Discharges, New York State Department of Public
Health, 1972.
7. "Wastewater Control Ordinance," Ordinance No. 270, East Bay Municipal
Utility District, Special District No. 1.
39
-------
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TABLE II
UNIT RATES WITHIN SPECIAL DISTRICT NO. 1*
CHARGE BASIS
RATE
Volume
Suspended Solids
Chlorine Demand
Oil and Grease
6.4*/100 cubic feet (Ccf)
2.7
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TABLE IV
CHARGES FOR SMALLER INDUSTRIES IN SPECIAL DISTRICT NO. 1
BASED ON AVERAGE WASTE STRENGTH CHARACTERISTICS
USER CATEGORIES
(Based on SIC)
7218
3110
2011
5812
2010
3410
2850
2040
2050
2020
2070
2090
2600
7210
2030
INDUSTRY DESCRIPTION
Industrial Laundries
Leather Tanning
Slaughterhouses
Eating Places
Meat Processing
Drums & Barrels
Paint Manufacturing
Grain Mills
Bakeries
Dairy Products Processing
Fats and Oils
Misc. Food Manufacturing
Pulp & Paper Products Manuf.
Commercial Laundries
Canning & Packing
ALL OTHER USER CATEGORIES
TOTAL CHARGE
*/Ccf
40
30
30
25
25
25
25
25
20
15
15
15
15
15
15
10
43
-------
TABLE V
SAMPLING FREQUENCY FOR INDUSTRY DISCHARGES
SAMPLE FREQUENCY
ONCE EVERY
6 months
4 months
3 months
2 months
6 weeks
4 weeks
3 weeks
2 weeks
10 days
7 days
LARGEST BI-MONTHLY BILL
$/month
0 - 100
100 - 250
250 - 500
500 - 1 ,000
1,000 - 2,500
2,500 - 5,000
5,000 - 10,000
10,000 - 25,000
25,000 - 50,000
>50,000
44
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TABLE VI
COMPARISON OF RECOMMENDED SAMPLING FREQUENCIES*
WASTEWATER DIS-
CHARGE RATE OF
FLOW
0.05 MGD
0.05 - 1 MGD
1 - 5 MGD
5.0 MGD
NEW
YORK
1
2
3
'
COUNTY
OF L.A.
0 to 1/3
1/3 to 4
4
4
SPECIAL DISTRICT NO. 1
ASSUME 10$
per Ccf
1/6 to 1/4
1/4 to 1
1 to 2
2 to 4
ASSUME 40
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3r the next calendar
re as specified in
er Discharge Permil
Gentlemen:
tfl TJ
t Ł
O v
>4H
O
chedule", Part G7
Attached are the i
quarter. The ele
the "Monitoring S
t over a normal worl
• 2 of your Wastewate
hich the sampling is
iatic samples taken
The volume dis-
« m S c .
i *J . O m
3 L ^ ••-> LI
C rt Ą p 3
^ s ^
^ 5 ^ ° o
S •" r rt S
> -S (U M ^
C^I & M^
S p.'S «2 x
a sample of your w
scharger Period" s
t should be used as
sampling inte rvals
ntervals must not e
Please composite
ing day. The "Di
Discharge Permil
performed. The
at periodic time i
^
§!
m "c
rt c
A u
2 *«
M E
u rt
samples for automa
iverage daily flow.
charged between i
exceed 5% of the *
rt v
*- 'rt
CT) 3
Ł S*
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c S >p
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> ™ JS
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_•*-> o
rt +3
0) rt
K S
O 00
3 D
Q. Li
tate Department of '.
p the sample under
The composite sa
certified by the Si
by EBMUD. Kee]
"2 ^
*^ ex
is
n •-
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o 0
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are run and retail
following submiss
TO W
O 0)
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^ ro
CO Ll
L. 0
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4) Li
C n)
v "
VI (U
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self-monitoring rep
n Part A5 of the Wa
Each discharger ;
name is entered i
-------
Wastewater Discharge Permit
Part A - Application/Permit
SECTION 1 APPLICATION
urrvlhe completed apiiliCdtion by
ther Instrucfons See inverse side
Applicant Business Njmp _____
Address of pfem.se disduiging waste
A Street .
EBMUO USE
e Application Receiv
Permit No ABA _
Acct Nos A9B _
City_
B Mailm
Chief Executive Office.
A Name ......
C Mailing Address . „
Person to be contacted about this applicat
A Name
_ B Title _
_ D City -
Name
Type ol Application (il buili ma
A HI WdSlewaler Flow Eslimali
B H Wdilew-le. Sliengih Dete
Check Pail til Cornell-t*es and chaigw when billed by ihe District
a Annual Permit Fee S
b Monthly Monitoring Piogi am Charges {sampling and testing) $
c Sewage Disposal Set vice Charge
2 Comptimcewnh I
EFFECTIVE DATE
as spedfted in Part G Specifically you are required ti
i in L8MUD Wdiei Pollution Control Department arty changes (permanent or temporary! to
lh.il iigii,l,Łjr.tlv change Ihe quality or volume of the waits water ducharge or deviate from the
5 EXPIRATION DATE
MANAGER WATER POLLUTION CONTROL DEP1
INSTRUCTIONS FOR COMPLETING PART A
SECTION 1 APPLICATION
Typt or print the information requested
inter the name or title of your business, preferably the lame name as ihown
EBMUD *
ir bill
A? Address of Pronto Discharging Wastewater - Enter me full street eddres* of the building or premise which is producing
the wattewater pertinent to ttin Application
A3 Business Address - Enter the business rtreet address and the full muling edorefi
A4 Chief Executive Officer - Enter the name, title and full mailing address of the Applicant's Chief E:
the home office (Thu n often not the same address at given in A3)
AS Person to be contacted about thtt Application - Give the name of the perio
reported on thete forms and who can b* contacted by the staff of EBMUO
iv* Officer in
thoroughly familiar with the facts
n Emergency - Give the name, title and telephone number (i) of the responsible
o* an emergency (e g spilling of a prohibited substance)
A7 Type of Application -
A Wastewater Flow Estimation - Mark this box if
20% or more of the water received at this premise from all source* » NOT discharged to the Community
Sewer AND y
e requested that your sewage disposal charges be based on volume estimation
Wastewater Strength Determination - Mark this box if
1) The primary business activity it this premise is required to have a Permit under the EBMUD Westewater
Control Ordinance, or
a strength determination of your
Check Part)*) Completed - Indicate which Partis) of this Application ate completed and attach them to your
Applttit'on
A8 Certification - The Application must be signed and dated by an officer, employee, or other agent of the business who
has legal authority to bind the Applicant bu sinew Also print or type the name and title of the person signing the
Application
Return the Application and required Part(s) to East Bay Municipal Utility District. Water Pollution Control Department, P O
BOM 24056. Oakland, CA 94623 by the date indicated at the top of the Application
SECTION 2 PERMIT
DO NOT COMPLETE THIS PART IT WILL BE COMPLETED BY EBMUD AND THE ORIGINAL RETURNED TO YOU
Wastewater Discharge Permit
Part B - Business Description
i primarily used to determine the tubttancat which may enter into
the wasMwaiei dMcharga from the Bus**** Activity The production quantities are necessary for Stan
and Federal Reportt and for intra-mduttrY companion*
PAtTCALCNDAM YiAB
UTiP TMI»CAHNOAR YIAB
- Describe the
the year (Use additional sheets as necessary)
• generating operations Indicate variations in production and operations during
wary)
I Subetamet Dfrehanad - Give common and technical namat of each major raw material and product that may
be discharged to the sewer Brwfly describe the physical and chemical properties of each substance and product
(b) Circle the days of the week that the discharge
occurs S M T W T F S
B3 Variation of Operation
Indicate whether the business activity »
Continuous throughout the year, or
Seasonal - Circle the month* of the year during
which discharge occurs
JFMAMJJASOND
B4 Other Liquid Wane* - Ltit the type and volume of liquid waste removed from the premises by means other ti
INSTRUCTIONS - SfŁ OH MACK
INSTRUCTIONS FOR COMPLETING PART •
Peart Immatom - Typt or pnni tin information A taparm Part B It to be emulated far aaeh major bourn* activity
Example* of major but*** activities are pamt manufacturing, metal plating, food canning, etc
Bl. fcadneai Activity - Describe the principal activity on the premi** For the purpoee of completing this Part, an activity
to • major budnan dast of manufacture (Me Example* above) Enter me Standard Industrial CMfkatton (SIC) Cod*
Number, • found in the 1972 Edition of the Standard Industrial Classification Manual prepared by the Executive
Office of the Prewdant. Office of Matujprnint and Budget, which it available from the Government Printing Office at
Wellington, 0 C.. or at San Franoaco California - DO NOT USE PREVIOUS EDITION OF THE MANUAL Copm
are alto available for examination at most public libraries and at the EBMUD Wattr Pollution Control Plant.
(a) PradHvt - Utt the types of products, giving the common or brand name and the proper or scientific name Enter
from your records the average and maximum amounts produced for this activity for the previous calendar year,
and the estimated production for thit calendar year Attach additional page* if necetury
(b) Deacription - Describe the wanmvatar generating prooeai occurring on the, prenuen. mdudmg any watonal
variation HI waitewater dncharge volumes, plant operations, raw materials, and chemicals used in process and/or
production
EXAMPLE At this location we manufacture paints, by a duparaon proem in which p
s JMbttanoe Discharged - Give common (brand name*} and technical namat Icfomical. sctentific or proper namat)
of each raw material and product that may be dnchargad to the sewer Briefly describe the physical, (e g. color)
and chemical, (e.g reacts with water) properties of each substance
Titanitol {Titanium dioxtdet
White inert powder used as a pigment
B2
(a) Enter the hours of the day during which waste from this Business Activity will be discharged to the sewer, • g
from 0000 to 1700 hour* (not 8 a m. to 5 p m \
(b) Cirdt the oayi of tha week thai tha w»tmmnr dischargt from this activity occurs
B3. Variation In Operation
Indicate whether tha business activity is continuous throughout the year or if it is seasonal If the activity is seasonal.
circle the months of the year during which discharge occurs Make any comment* you feel are required to describe
thr variation in operation of your business activity
B4 Other Uquid Wastes - Litt tha type and volume of liquid waste* removed from the pramtw* other than bv th*
community sewer Under description, indicate the types of ma ten alt (scientific and common namat) in tha watte Also,
in the column headed "REMOVED BY," write the name and address of the company who haul* this material H you do
your own removal and disposal, indicate by wnbng your "Business Name "
48
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Wastewater Discharge Permit
Part C - Schematic Flow Diagram
ftjfpoae- ThtS
variOUt MM
pMk flowi Of the dteharga
n the flow pattern of product! through the facility md the
Ion will enable EBMUD to aueu the quality, volume and
EBMUD USE
Perm*
Sohamatfe Flow Diagram - For each mater activity In which
«nd water from lUrt to completed product, ihowlng ill unit
wanewtter dncharget to the community tewer UM the*
in Pert D
nr it generated, draw • diagram of the flow of material*
t generating wMttwiwr Number each unit proceu hiving
wh«n thowtng thil unit proceti In the building layout
IH3TKUCTIONS - tfl ON IACK
INSTRUCTIONS FOR COMPLCTHM PART C
general Inttructkxw - Typt or print UM Information A Moarat* Part C ehould be complMMl for eech major butinen
activity dncribwi in Part B
A lin« drawing Uchematk flow dbgrwi) of Mch mi|or buiirmt MlMtv dMcrlbrt In Part B If to ba comptowd In th*
va« telow or drawn (n on an attachad tfMtt of p»P«r W\ **«• *ouM ba tattar *«i Nufflbw aach proom wh.ch
g^f.U. wMnntar utiftg th. »ma numbwing M In th. building layout or plant Ut. plan rttown in Part D An axampb
of th* drawing nquirad b ihown blow In Flour* 1
To datwmin. your avaragt daily voluma and mwimum dally voluma of w«t«MUr Mow you m-y h«va to rMd watar m«ar*.
•twar matari, or rnak* attimwa. of «lur«ai that ar« not diractiy irMMuribta
FIGURE 1
ACTIVITY Ft*
Orlad
•*Maal
Product
OMtripttort- Flow diagram at fen maaJ Md IWi oil prooaaiing opMttom.
Wastewater Discharge Permit
Part D - Building Layout
- The BuiMng Layout (howl the
T Tin building layout will elio en
for determining and verifying
ganarwing oparnwrn whudi contributa to aach
EBMUD and th* applicant to Mtect luitabl* umpllng
EBMUD USE.
Parrmt
Buridim Layout - Dr«w to tcale th* location of each building on the premiMt Show toeation of all www metert, Korm
drum numbered unit proomei (from Part C). community iewar» and each tide wwer connected to the community wwerj
Numbar each iid* iewer and ihow pottibla templing location
IMfTRUCTIOM FOR COMPLETINO PABT 0
OMMral iMtruetbMM - Typa or print tha information
BuWloe.L.YOut- AbUil*rM|l^^torpl^t^t.pUnoflr*pr«T11M»r»qUJ™dt0corr<4«.ParlD (Buikting Plans approved
by EBMUD. may bt tubttituted for Part D ) An arrow ahowing north at wall m th* map tcale mutt be **own The location
of each exitting and propotad umpling manhole and tide wwer mutt be cteerty identified at well« all tannery *nd wattewatBr
drainage plurnbing. Number each unit proceai ditcharging waiieweui to the commurHty wwer UMI the tame numbering tyttem
rfiown in Pert C (Schematic Flow Diagram) Art example of the drawing required it chown below in Figure 2
49
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Wastewater Discharge Permit
Part E - Water Source & Use
Purpose - The Water Source and UM information will enable EBMUD to
and Sources of wute water discharged to the community sewer
determine the Vol
mes
EBMUD USE
E 1 Water UM and Disposition - Estimate the average quantity of water received and wa*tawater discharged daily
NOTE Show on separate sheet the method and calculations used to determine the quantities shown on the table
WATER USED FOR
Sanitary
Processes
Boiler
Cooling
Washing
Irrigation
Other 13)
TOTAL
Notev
(1) Enter th
(2) Enter th
a well,
(3) Describe
SUPPLY FROM
EBMUO
td/div
Other It)
(•I/day
Swim
D
Camm S*w*r
tpl/diy
t quantity and the appropriate code letter indicating the source
> creek, c estuary d bay • storm water, f reclaimed water
e quantity and the appropriate code letter indicating the discharge point
> creek, c estuary, d bay e stormdram, f rail, truck, barge, g. evaporation, h
SCHAROED TO
Oth*rl2l
tH/Bty Olteti To
product
E2 Number
WEEKDAY
SATURDAY
SUNDAY
of Employee!
OFFICE
No
How*
to
to
- m^ |
PROOLK
flftY ^HouTi
to
to
TION (nimOw of trnptoy
"'"NO '"
"•"•K.
« PH rtiiftl
to
to
to
to
to
E3 Source of Waitewater Discharged
WATER MET
NUMBER
ER
PERC
SIDE SEWER No 1
ENT 1X1 DISCHARGE
SIDE SEWER No 3
D T
0
SIDE SEWER No 3
SIDE SEWER No 4
TOTAL % DISCHARGED
TO ALL SIDE SEWERS
INSTRUCTION - SEE ON SACK
INSTRUCTIONS FOR COMPLETING PART E
General Instruction* Type or print the information Part E 11
(Wastewater Strength and Flow Estimations)
fnpleted by all dischargers who require a permit
Water UM and Dupotitton - Estimate the water received and wastewater discharged in gallons per day for the
preceding year For the water that is received from other than EBMUD lervices or discharged to other than community
sanitary Mwers, enter the appropriate letter in the column headed "Source" or "Discharge To "
The total supply from EBMUD should be cnecked using recent water bills to verify the estimates
Number of Employee* - Enter the average number of office and production employees at the premiM* daily during the
preceding year If there is more than one shift per day, enter the average number of employees per shift and the
duration
Sourc* of Wattevmer DBcharged - I tern E3 shows the percentage o
computing the sewage disposal service charge
e water on each water n
Step 1 Enter the number of each meter (EBMUD and private) serving the premise
Step 2 For each meter enter the percentage of water discharged to each side sewer If you have more than one tide sewer,
show on a separate page the method and calculations used to determine the proportioning to the side sewers
Step 3 Enw the total percentage ditchaiged to a\\ side seweit lor each wtter meter by adding the tigurei in eacti side
50
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Wastewater Discharge Permit
Part F - Side Sewer Discharge
Purpose - The Stdt S«ww Ducharge informal
and the type of constituents and characteristics
jn will identify for EBMUD the variant
af the discharge for each side iewer
F2 YV.ttew.Wr Flow Ratt
PEAK HOURLY
If Batch Ditcharge, Indicate
scharges .
ti scharges
y per batch _
Number of bate
Time of batch d
W>newat*r Constituents - Indicate if any of the following o
IX) in your wastewater discharge at» result of your operations
-CLT-
CONSriTUtHTS
Oil & Grease (Mm Orifl)
al Compounds or Element
TOT
Temperature Decrease 1-1
INSTRUCTIONS FOR COMPLETING PART F
G«n*r*4 I nit ructions — Type or print the information Part F is to be completed by all businesses who require Waste water
Strength Determination Use a separate sheet for each side iew*r that discharges waste water to a community sewer {NOTE
A iida sevwr is a sewer conveying the waste water of a discharger from a building or structure to a community sewer)
w shown
Wtttewater Flow Rate - Ei
discharged during
mber for which this sheet of Part F has been c<
Use the same number
iaie the peak hourly discharge rates from the premise |i e the quantity which might be
my one hour) The maximum daily discharge rate is the greatest flow which might be discharged in
any one work day The annual daily average n the flow for an average workday taken over one year of operation A
season is defined as a period of one month or longer Hourly and daily water supply meter readings may be used
provided the filling and discharge of storage tanks, process vats, etc are taken into consideration
Batch Discharge - A batch discharge is one which results from the draining of storage tanks or process tanks
intermittent boiler blowdown, etc , to the side sewer
* Enter the number of batch discharges per month during the operating season of maximum flow
b Enter the days of the w«ek the discharge occurs and the times of the day the discharge usually occurs
c Łnter the average gallons discharged during each batch discharge operation
d Enter the rate of flow in the side sewer from the batch discharges
(ie Hate of flow fro
i the I
atch discharge
. Number (
n batch discharge \
tion for a single discharge
Wntewater Constituents - Indicate, by checking the appropriate box, if your wastewater discharge contains .
indicated constituents, characteristics, or substances as a result of the raw materials, processes or prodi
Identify the algicides, hydrocarbons, pesticides, solvents and radioactivity discharged if any, in the wastewate
Waitewattr Strength E in mates - Enter the average and maximum concentration of each of the indicated eli
wastewater strength for this side sewer The average strength should approximate the flow
the year
sited strength during
(Flowci
n posited strength
num Strength '
Total milligrams of substance discharged
is side sewer
inual volur
these v
of water discharged in
in that would be measured in any grab sample taken
5 acceptable to EBMUD they will become the basis
Total
The "Maximun
durmg the year
disposal charge!
The "Chlorine Demand" of a wastewater i
in contefmance with (he Standard Method
FB Pollution Abatement Practices
a W«stawat*r Pretreatment
Description The treatment facility should be described in suffn
effectiveness This will require a description of the physical ch;
sheets as necessary )
b Planned Watt*water Treatment Improvements
Describe any additional treatment or changes in wastewater disposal methods planned or under const n
F7 Storm water Area - Enter an estimate of the total area (in square feet) which collects and discharges jtormv
side sewer (include roof and ground level areas)
n the wastewater f
discharged to the
if the facility (Use additional
PART F - Side Sewer Discharge (Cont'd)
WaitnvaMr Strength Ettimitei - Enter the average annual and maximum wastewater strength for this side sewer for each
of the following elements of wastewater strength for the period covered by The Permit
ANY SIGNIFICANT DEVIATION FROM THESE VALUES CAN RESULT IN TERMINATION OF THE PERMIT
ELEMENTS OF WASTEWATER STRENGTH
Suspended Solids
ie and address ot the labor at
F6 Pollution Abatement Practices
a WwWwBter Pretre*Dnent — Check the type of treatment if any given wattewater from this side sewer before
CUnone Dholdmgtank Dgrease trap, Doil and water separator, CJ grinding D sedimentation DpHadjustmi
d biological treatment D screening L~J chlormation or D other
Description
Describe the loading rates, design capacity, physical s
c of ea
Planned Wastewater Pretreatmant Improvement* - Describe any
treatment or disposal rr
F7 Stormwiter Area
Total Area in squar
'RUCTIONS - see ON BACK
P»gi 2 of 2
51
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Wastewater Discharge Permit
Part G - Permit Conditions
G1 Applicant Nam* (Same a:
•n Appl'C
G2 BCC - Enter the Business Classification Code Assigned to this business by EBMl
G3 SIC - Enter the Standard Industrial Classification Codes for each mafor activity described in Part B
1 1 I II J Pan B, Page ,& ' 77 I . 1_J Pa" B, Page .
SECTION 1 CALCULATION OF SEWAGE DISPOSAL SERVICE CHARGES
n establishes a single charge for each water meter based on the strength and volume
Purpose This Sect11
each side sewer
G4 Sewage Dupoial S*mc« Charge Determination for Each Side Sewer
f the wastewater in
(a) Excess over 30 mg/l (b) Excess over 40 mg/l
G5 Determination of th« Total Chary to be applied to each Water H
SIDE SEWER NO 2
SIDE SEWEB MO 3
G6 Sewage DifpoMl Service Charge Determination for Each Meter
(1) Show on an attached sheet the method of e
(2) Show on an attached sheet the method of c
ating the amount of waste water discharged from the pi
puting the Sewage Disposal Service Charge
INSTRUCTIONS FOR COMPLETING PART G
General Instruction. Type or print the information Part G will be completed by EflMUD
G1 Applicant Name - Enter the legal name or title of the business as shown on the Permit Application
G2 BCC No - Erttar the four (4) digit Business Classification Code Number assigned by EBMUD
G3 SIC No - Enter the Standard Industrial Classification Code Number from the 1972 Edition of the Standard Industrial
Classification Manual prepared by the Executive Office of the President, Office 0* Management and Budget Copies are
available from the Government Printing Office at Washington, D C , or at San Francisco, California Copies are also
available for examination at most public libraries and the Water Pollution Control Plant of EBMUD DO NOT USE
PREVIOUS EDITIONS OF THE MANUAL!
G4 Swung* Disposal Sent* Charge Dettrmtnaroon ID* Each Side Sewer
This matrix enables the sewage disposal service to be determined for each 100 cubic feet {Ccf) of water used from each
water meter
Step t Enter the projected average annual wastewater strength for suspended solids, chlorine demand in excess of
30 mg/l, and Oil and grease in excess of 40 mg/l
Step 2 Convert the answer from Step 1 (mg/l) to pounds per hundred cubic feet (Ibs/Ccf) of wastewater by
multiplying the mg/l by 62 4 x 10 4
Sup 3 Calculate the charge for each element by multiplying the Ibs/Ccf by the Unit Charge shown in the District i
latest Schedule of Rates and Charges
Step 4 Determine the Total Charge by adding the individual 4/Ccf
GS Determination of the Total Charge Applied to each Water Meter - The total charge computed for each water meter
will be applied against the volume of water shown on the meter reading (Deductions will be made in item G6 for
volumes ex percantagK noV dischaiged to the tide tewet t
Stapl Enter in Column (1) the unit charge for each side sewer as computed in item G4 "Total Charge "
Step 2. Using the total percentage discharged (see item E3) compute the percentage discharged to each side sewer
Enter these percentages in the respective Column (2) "% Disch "
Step 3 For each water meter and each side sewer in turn, calculate the product of the "Unit Charge' and the
"Percentage Discharged " Enter the resulted in the column headed 'Column (1)x(2) "
Step 4 For each water meter add the "Column (1|x(2)" to giv* the total charge to be applied to each water meter
Enter the result in the column headed 'Total Charge for each Water Meter "
G6 Sewage Disposal Service Charge Determination for Each Meter
A Account No - List all account numbers pertaining to this Permit with the "Key Account" first
The "Key Account" number is an account number used for the permit identification (Permit Number)
6 Meter No - For each account number list the water meter numbers assigned to that account The letter p"
alter the mewi numbei indicates a private metel
Urot of Measurement - Enter the unit of measurement (e g cubic feet, gallons, 1000 gallons, etc )
C Conversion Factor — If the unit of measurement is other than gallons CM cubic feet, enter a factor which will
convert the meter reading to Ccf (e g , a factor for converting time on a time elapse meter to Ccf)
D Fixed Volume - If a fixed volume is charged to a meter or to an account enter the volume in Ccf The volume
may be positive or negative If negative, the value is to be preceded by a negative sign (-)
E Total Percentage (%l Discharged - Enter the percentage of the water registered by each meter that is discharged
to the community sewer This factor only applies to the amount appearing on each meter reading The percentage
does not apply to the volume appearing under the column headed "Fixed Amount " If the figure is preceded by
a negative sign the amount computed will be deducted from the sewage bill
F Total Charge per Ccf - Enter the total charge for each water meter previous
G7 Monitoring Schedule - Enter each element required to be mo
maximum concentration for each of these elements In the colu
frequency in weeks for each element or constituent Testing is 1
(we GUJ
G8 Monitoring Program Charges
A Compute the sampling and testing charge based on the annual
B Permit Fee - $175 for accounts requiring both flow and si
G9 Laboratory Testing. - EBMUD may approve laboratories not approved by the State Department of Public Health when
the Applicant desires to perform EBMUD required tests in his laboratory Indicate whether 3 laboratory approved by
the Department of Public Health of the State of California or EBMUD will be used for the testing
G10 Time Schedule - EBMUD will enter the actions required to remedy the ordinance violations or compliance schedules
rmined in item G5
nilored by the Permittee Enter t
mn headed "TEST FREQUENCY", enter the te-
:o commence from the effective date of the Perm
; average and
number of samples and tests required by EBMUD
rength determinations $100 for accounts requiring
Purpose This Sec
|H^ Monitoring Schedul
SECTION 2 MONITORING AND COMPLtANCE CONDITIONS
ction establishes suitable monitoring and compliance programs
PART G - Permit Condition* (Cont'dJ)
, A. Monitoring Program Charge!
TOTAL SAMPLES PER YEAH A Q
TOTAL TESTS PER YEAR B D
$. Permit Fee D S175 D $100
Laboratory Tejting - Indicate the laboratory to be used by Permittee
-Ai GJ Laboratory approved by the State Department of Public Health
S. D Laboratory approved by EBMUD
> schedules for compliance wi1
es, and other orders by t
and prohibitic
le Manager
TIME SCHEDULE
Effective Date of thu Permit L_J I J
Expiration Date of this Permit I I I 1
52
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USE OF ROTATING BIOLOGICAL CONTACTOR ON
MEAT INDUSTRY WASTEWATERS
by
Don F. Klncannon*, Jinunie A. Chittenden**, and
Enos L, Stover*
INTRODUCTION
Available land is a key consideration when planning wastewater treatment
facilities for the meat processing industry. Some plants are so located
that land is available for anaerobic ponds and additional aerobic treat-
ment. Whereas, other plants are so located that it is difficult to find
space for any type of wastewater treatment. This is especially true of
processing plants that are located inside the city limits and discharge
their wastewaters into the city sanitary sewer. In many communities these
plants are being required to pretreat their wastewaters before discharging
into the sanitary sewer. In many cases these same meat processing plants
incorporate very little if any recovery operations, thus producing a waste-
water that is very difficult to treat.
This paper will report on an experimental study that was conducted in
order to determine whether or not a rotating biological contactor could
successfully treat the wastewaters from a meat processing plant that did
not incorporate any in-plant recovery operations.
Chittenden and Wells ( 1 ) have previously reported on treating meat pro-
cessing wastes by following an anaerobic lagoon with a rotating biological
contactor. This paper will also report on additional work that has been
completed with this treatment process.
RBC TREATING RAW WASTES
Treatment Plant Description
The experimental study on a raw meat processing waste was conducted in
the Bioenvironmental Laboratories at Oklahoma State University. The
wastewater was obtained from a meat processing plant located in Perkins,
Oklahoma, which is ten miles south of Oklahoma State University. No in-
plant recovery operations such as blood recovery or grease recovery is
practiced. The RBC was initially set up at the meat processing plant,
however, numerous operational problems occurred. It was then decided to
move the RBC into the laboratory and transport the wastewater.
The rotating biological contactor*** employed for this study was a four-
foot long unit. It consisted of six compartments or stages with five
polystyrene discs in each stage. The total surface area of polystyrene
*School of Civil Engineering, Oklahoma State University.
**Iowa Beef Processors, Inc., Dakota City, Nebraska.
***Autotrol Corp., Milwaukee, Wisconsin.
53
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medium available for microbial growth was 177.5 square feet. This was
contained in a volume of 11.8 cubic feet giving a specific surface area
of 15 ft^/ft . A 1/10 horsepower electric motor rotated the discs at
eleven revolutions per minute. The discharge line from the final stage
of the unit was located such that the liquid volume in the unit was ten
gallons. It was learned after all experiments were completed that an
adaptor is normally installed in the discharge opening so that the unit
would have a liquid volume of thirty gallons. Thus the detention time
employed in this study was less than normally employed with this particular
RBC. A flow rate of 0.5 gpd/ft^ was utilized in all experiments of this
study. With the ten gallon volume used this provided a liquid detention
time of two hours and 40 minutes.
A slim growth was developed on the discs by first operating the unit as
a batch operation. Then gallons of meat processing wastewater was placed
in the RBC with a sewage seed from the Stillwater, Oklahoma, municipal
sewage treatment plant. After the slime growth started to develop the
unit was then operated as a continuous flow process. During the length of
the study the unit was operated part-time as a batch process in order to
save on the quantity of meat processing wastewater that had to be trans-
ported. In all cases the unit was operated as a continuous flow unit for
a sufficient period of time before samples were taken. That is, the unit
was allowed to reach steady state conditions before sampling began. In
some cases the meat processing wastewater was diluted with tap water in
order to provide the desired initial ACOD.
The term ACOD is defined as the difference between the influent COD and
the nonbiodegradable COD. Thus, ACOD measures only the biodegradable
organics present in the wastewater and is therefore comparable to the
ultimate BOD.
Results
The ACOD remaining at each stage for a typical experiment is shown in
Figure 1. It can be seen that samples were collected and analyzed at
regular intervals for at least a seven or eight hour period. The average
removal for this time period is used in presenting the rest of the results.
It can be seen in Figure 1 that at least 50% of the ACOD removed occurred
in the first stage.
Figure 2 shows the percent ACOD removed by stages for experiments con-
ducted at three different organic loadings. The RBC was capable of
removing 74 percent of the ACOD when the initial ACOD was 1410 mg/1. How-
ever, the removal efficiency was greatly reduced when the initial ACOD
was increased. When the initial ACOD was 4510 mg/1 the removal efficiency
was only 18 percent.
The actual ACOD's remaining for these experiments are shown in Figure 3.
In all cases the effluent ACOD was much too high for discharge into a
receiving stream. However, for an initial ACOD of 1410 mg/1 the effluent
ACOD was 370 mg/1. This reduction would make this wastewater much more
acceptable for discharge into a sanitary sewer. The removal character-
istics of the RBC when the initial ACOD was 1410 mg/1 is also shown in
Table I.
54
-------
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80
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INITIAL ACOD
o !4IOmg/4
A 2300mg/X
n 451
12345
UNIT LENGTH, STAGES
Figure 2. PERCENT ACOD REMOVAL
PER STAGE.
-------
5000
I 23456
UNIT LENGTH, STAGES
Figure 3. ACOD REMAINING PER STAGE.
-------
Table I.
Stage
Influent
1
2
3
4
5
6
Summary of RRC Operation at
ACOD, mg/1
1410
935
770
610
505
420
370
% ACOD
removed
per stage
34
18
21
17
17
12
Low Organic Loading
Total
ACOD Substrate Removal Rate
removed (k)
34 ^ = 0.180
54
57
64 k2 = 0.073
70
74
It was found in all experiments that the ACOD was removed in two phases.
The first phase usually being the first stage and the second phase being
the remaining stages. In a few cases the first phase would extend into
the second stage.
A summary of ACOD removed per stage for three experiments is shown in
Table II. It is interesting to note that no matter what the initial
ACOD was the same mg/1 of ACOD were removed by corresponding stages. The
first stage consistently removed at least 50 percent of the total ACOD
that was removed.
Table II.
Influent
ACOD
1410
2280
4510
ACOD Removed Per Stage
Stage 1
475
480
430
mg/1 ACOD Removed Per
234
165 160 105
120 140 90
100 70 30
Stage
5
85
70
40
6
50
50
80
58
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A summary of the percent ACOD removed for all initial ACOD values is
shown in Figure 4. It can be seen that as the influent ACOD increased
the removal efficiency decreased. The ACOD loading in mg/1 does not take
into account the hydraulic loading. One way of considering both the
organic loading and the hydraulic loading is to consider the organic load-
ing in pounds per day. Also the variation in different sizes of RBC's
can be accounted for if the loading is calculated as Ib ACOD/day/lOOOft2.
The percent ACOD removal for various total loadings is shown in Figure 5.
Again the percent ACOD removed decreases as the total organic loading is
increased. It can also be seen that a 70 percent efficiency was obtained
at a loading of 5 Ibs ACOD per day per 1000 ft2 of RBC area.
A summary of work completed on a carbohydrate wastewater is shown in
Figure 6. The results of that study are compared with the results obtained
from the meat processing wastewater study. When the RBC was used to treat
the carbohydrate wastewater a high removal efficiency was achieved for a
rather high increase in organic loading. However, when this same waste-
water was treated with either a plastic media biological tower or a rock
trickling filter the efficiency immediately started decreasing as the
organic loading was increased. It is interesting to note that when treat-
ing the meat processing wastewater the RBC acted more like the biological
tower or trickling filter. That is, the efficiency began to drop as soon
as the organic loading was increased.
There was one very great difference in the RBC when treating the carbo-
hydrate wastewater and when treating the meat processing wastewater. The
suspended solids in the liquid in the unit were quite high with the carbo-
hydrate wastewater, varying from 500 - 6000 mg/1. However, the suspended
solids concentration with the meat processing wastewater was quite low,
varying 'from 100 - 200 mg/1. Thus with the carbohydrate wastewater the
RBC was acting both as an activated sludge and as a fixed-bed reactor.
However, with the meat processing wastewater the RBC was acting only as
a fixed-bed reactor.
RBC FOLLOWING AN ANAEROBIC LAGOON
Treatment Plant Description
The pilot plant study on a meat processing wastewater after undergoing
treatment in an anaerobic lagoon was conducted by the Iowa Beef Processors,
Inc. at their plant in West Point, Nebraska.
The RBC* employed for this study was a four stage unit utilizing the
"Extended Area Disc". The total surface area available for microbial
growth was 250 square feet. There were 9 discs per stage for a total
of 36 discs. The discs were rotated at 13 revolutions per minute. The
liquid volume of the unit was 37 gallons. During this study the hydraulic
loading varied from 0.57 gpd/ft2 to 2,16 gpd/ft2. This allowed the de-
tention time to vary from 1.64 hours to 6.17 hours.
*Autotrol Corp., Milwaukee, Wisconsin.
62
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Results
The BOD remaining at each- stage for 3 different days of operation is shown
in Figure 7, Again it can be seen that the majority of the BOD removed
is removed in the first stage and very little BOD is removed in the last
three stages. These results are very similar to those obtained on the
raw meat processing wastewater.
The pounds of BOD removed per day per 1000 ft^ of RBC surface area for
corresponding BOD loadings are shown in Figure 8. A straight line can
be drawn through the data points and the slope of this line represents
the efficiency of the RBC unit that can be expected at the loadings
studied. The results of this study show that a 71 percent efficiency
was achieved during this study.
The effluent BOD that was obtained for various BOD loadings is shown in
Figure 9. It can be seen that as the BOD loading increased the effluent
BOD also increased. It is also evident that a low BOD loading is required
before achieving an effluent that is acceptable for discharge to a stream.
In this study a BOD loading of 0.9 lbs/day/1000 ft^ or less was required
to achieve an effluent BOD of 20 mg/1 or less. This is a very low load-
ing rate.
DISCUSSION
In these experiments a very interesting phenomenon was observed. The
majority of the ACOD or BOD was removed in the first stage and very
little was removed in the remaining stages. This is shown in Figure 3
and Table II for the raw waste. In Table II it can be seen that approx-
imately 470 mg/1 of ACOD was removed in the first stage. The maximum
amount removed in any other stage was 165 mg/1. Figure 7 shows that the
same thing occurred with the settled anaerobic lagoon wastewater. This
is a strange response especially when it is remembered that a very suf-
ficient amount of ACOD or BOD still remains after the first stage. No
explanation for this phenomenon is offered.
During these experiments it was also observed that the RBC was an excellent
evaporator. In fact, it does such an excellent job of evaporating that
this must be taken into account when operating the RBC system. Either
a continuous wastewater flow must be supplied to the reactor or recycle
must be incorporated into the operational plan. Certainly this must be
considered in light of the operational hours of meat processing plants.
These experiments have shown that the RBC can effectively treat both
raw meat processing wastewaters and meat processing wastewaters following
treatment by an anaerobic lagoon. However, the organic loadings must be
quite low below acceptable effluents are obtained. This may make the
RBC quite expensive. No economic comparison with other treatment processes
has been made. Therefore, no conclusions can be made about whether or not
the RBC is an economical process for meat processing wastes.
63
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1. CHITTENDEN, JIMMIE A. and WELLS, W, JAMES, JR. Rotating Biological
Contactors Following Anaerobic Lagoons, J. Water Pollution Control
Federation, Vol. 43, pp. 746-754, May 1971.
66a
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INDUSTRIAL WASTEWATER REUSE
by
James D. Clise *
INTRODUCTION
For the past three years the Environmental Health Administration of Maryland's
Department of Health and Mental Hygiene has been involved in a study at one of
Maryland's poultry processing plants.
The objective of the study was to demonstrate the feasibility - both technical
and economic - of reclaiming poultry plant wastewater for reuse as potable
water. Our efforts to this point have been successful in demonstrating technical
and economic feasibility of reclaiming poultry processing wastewater to levels of
compliance with drinking water standards. The question remaining is - what
possible dangers could accompany reuse of this water which would not be evident
in normal drinking water evaluations, or what standards should apply to reclaimed
water to assure its safety.
Sterling Processing Corporation, a company engaged in the slaughtering, eviscerating,
and processing of poultry, is located in Oakland, Maryland. Plant facilities were
constructed in 1956-57, with an original capacity of 3,000 birds an hour, equipped
to process broilers, fowl, turkeys, and kosher killed turkeys. Present plant
capacity is 6,000 birds an hour with operations restricted to the processing of
broilers, averaging 167,000 Ibs. live weight killed (iwk) per day. The plant has
never had an adequate - reliable water supply.
The community water supply serving the town of Oakland is of inadequate capacity
to provide water to the poultry plant. Groundwater resources in the area are
limited and of unsatisfactory quality. Sterling Processing Corporation constructed
two wells in 1956, and has since acquired a third well which was abandoned by
Oakland when the town obtained a surface water supply. In 1965, a water treatment
facility was constructed at the poultry plant and is currently in use for the
removal of iron and control of bacteriological quality.
Prior to the beginning of this project, Sterling Processing Corporation initiated
a series of water conservation measures. Initially, an employee awareness program
was conducted. Written directions were issued and daily inspections were made to
identify opportunities for employees to assist in the reduction of wasted water.
The entire piping system was inspected and all leaks eliminated. Where possible,
the use of hoses was eliminated and all essential hoses were equipped with
automatic shut-off valves. A valve was installed on each supply line serving the
processing plant to allow for regulation of flow. A portable high pressure cleaning
system was installed and cleanup personnel were provided with brooms to assist in
the removal o± solids from the floors. Refrigeration compressor water was recycled
to the raw water section of the water treatment plant. Pumps were provided to
allow the recycling of chill vat water for reuse in the scalder. Valves were
provided on the water lines leading to the water treatment plant filters to more
closely control filter rates and eliminate water pressure variations within the
Director, Bureau of Community Health Protection, Environmental Health Administration,
Maryland Department of Health and Mental Hygiene, Baltimore, Maryland 21201
67
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distribution system. These efforts reduced water consumption from 11 gallons
(lH.6k liters) per bird to an average of 6.8 gallons (25.71; liters), but did not
solve the problem of insufficient water. This continuous need for water, plus
the good quality of'effluent being discharged to the river made this plant
susceptible to the idea of water reuse.
The study provided an opportunity for a thorough evaluation of the Sterling
wastewater treatment system.
DISCUSSION
Poultry processing wastes are treated and disposed of by rotary screening for
removal of feathers and viscera which are sold for protein reclamation, with
wastewater treated in two mechanically aerated lagoons in series, followed by
chlorination and discharge to the Little Youghiogheny River. Present wastewater
treatment facilities were constructed in 1965-66, replacing an anaerobic lagoon
which discharged into the Oakland sewer system.
The wastewater treatment system consists of two lagoons totalling 2.75 acres in
area. Each lagoon is llj.0' wide. The primary unit is 590' long and the secondary
lagoon is 230' long. Each pond is six feet deep. Primary lagoon capacity is
approximately 3.75 million gallons and secondary capacity is 1.5 million gallons
providing holding capacity for 12 working days' flow.
The primary lagoon is equipped with 6k Link Belt circulators, a grease skimmer,
and an effluent wier trough discharging into the second lagoon.
Aerated Lagoon Showing Water Circulation
68
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Entering at the bottom of the circulators, wastewater is discharged at the
surface in one direction, creating a counter-clockwise surface flow.
Air is supplied to the circulators by three positive displacement blowers, each
powered by a 20 hp. motor. The system provides 3,360 cfm of air at 2.8 psig.
Air is distributed to the circulators through a header pipe encircling the two
lagoons.
The secondary lagoon is equipped with UO Link Belt circulators, a grease skimmer,
and a combination settling unit and chlorine contact chamber with an overflow
wier trough and discharge line to the river.
• **>?
:
1
i
Secondary Lagoon Showing Chlorine Contact Chamber
Incoming raw wastewater has a BOD^ averaging 5UO mg/1, amounting to a loading
approximating U80 Ibs/acre/day with a 93% reduction in the lagoon system. Raw
wastewater suspended solids average 831 mg/1 equalling a loading of 7^0 Ibs/acre/day
with an 88$ reduction in the system.
Wastewater treatment facilities were designed and installed by Griffith Engineering
of Falls Church, Virginia.
Preliminary grab sample evaulations of wastewater lagoon effluent indicated the
wastewater treatment facility reduced the BOD value to an average of 1$ mg/1,
69
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and reduced suspended solids to 58 mg/1.
WASTEWATER LAGOON EFFLUENT CHARACTERISTICS
USED AS BASIS FOR DESIGN
mg/1
Grease 7.8
Phosphate as P 1.3
Iron as Fe 0.3
Chloride as Cl 88
Nitrogen as Free Ammonia 8.8
Albuminoid Ammonia 1.0
Nitrites 0.005
Nitrates 3.0
Alkalinity as Calcium Carbonate 1U8
Hardness as Calcium Carbonate 178
Turbidity 30
Color 80
Chemical Oxygen Demand (COD) ll|0
Total Solids 1*26
Dissolved Oxygen 2.9
Suspended Solids 58
Volatile Solids ij.00
pH 7-0
Wastewater lagoon effluent characteristics, as determined during the study,
exceeded the basic design criterion from 52$ to 77$ as shown, resulting in over-
loading of equipment and the subsequent alteration of project design.
WASTEWATER LAGOON EFFLUENT QUALITY VARIATION FROM VALUES USED FOR
DESIGN OF ADVANCED TREATMENT UNIT
BOD^
Suspended Solids
Grease
Design
Value
mg/1
1U.8
58
7.8
12 Month
Mean
mg/1
31
106
2U
12 Month
Median
mg/1
25
109
19
Percent
Samples
Exceeding
Design Value
52.3$
70.0$
76.7$
70
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WASTEWATER TREATMENT AND
WATER RECLAIMING FACILITIES
CHLORINE
CONTACT
CHAMBER'
TO RIVER
COLLECTION
BASIN
LAGOON
B
LAGOON
ROTARY
SCREENS
SAMPLE IDENTIFICATION
-SCREENED RAW WASTEWATER
-PRIMARY LAGOON EFFLUENT
~ SECONDARY LAGOON' EFFLUENT
-MICROSTRAINED EFFLUENT
- FILTERED WATER
MICROSTRAINER
CHLORINATOR
DIATOMITE
FILTER
PRESSURE
STORAGE
TANK
EVISCERATING PLANT
Original Design
71
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WASTEVVATER TREATMENT AND
WATER RECLAIMING FACILITIES
, TO RIVER
SAMPLE IDENTIFICATION
A - SCREENED RAW WASTEWATER
B- PRIMARY LAGOON EFFLUENT
C- SECONDARY LAGOON EFFLUENT
P -MICROSTRAINED EFFLUENT
Y- FLOCCULATED - SETTLED
EFFLUENT.
- FILTERED WATER
FLOCCULATION-
SEDIMENTATION
BASIN
CHLORINATOR
PRESSURE
STORAGE
TANK
SAND
FILTER
EVISCERATING PLANT
Revised Design
72
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Advanced Treatment Design
Basic design of the water treatment facility consists of a control building^
35 micron microstrainerj diatomite filter containing 200 square feet of septum,
rated at 1.6 gpm/sq ft; and 20,000 gallon pressure storage tank.
Supplemental equipment consists of a 3,000 gallon concrete pit used as a
collection sump for lagoon effluent; sewage pump for the delivery of effluent
to the microstrainer; high head pump for delivery of microstrained effluent to
the diatomite filter (Ł0 psi); chlorine recorder; and electrical control panel.
All equipment is automatically controlled by the water height in the pressure
storage tank. Each unit can be independently operated manually. All equipment
is automatically controlled by the water height in the pressure storage tank.
Each unit can be independently operated manually. All equipment is rated at
approximately 300 gpm.
Equipment is housed in a 20' x 30' concrete block structure located between the
poultry plant and wastewater treatment lagoons.
Six inch PVC pipe is used to carry effluent from the secondary wastewater treat-
ment lagoon overflow sump to the control house. All piping within the control
house is 6" steel with bolted flange connections.
Solids removed by microstraining of the wastewater lagoon effluent are returned
to the primary wastewater lagoon by gravity flow from the microstrainer drum.
The operational phase was conducted in two segments. The first utilized facilities
as originally designed consisting basically of a 30 micron microstrainer and
diatomaceous filter. The second segment incorporated changes made in an effort to
solve unanticipated treatment problems and utilized 70 micron screening, flocculation,
sedimentation, and sand filtration.
Operational Problems
The advanced water treatment involved in reclaiming poultry processing wastewater
as you can imagine presents numerous unusual water treatment problems:
Microstrainer screens were continuously backwashed by cold water sprays for removal
of algae and other suspended particulate matter. Due to the presence of grease, it
was necessary to provide a source of hot water for occasional removal of adhering
matter.
Seasonal variations in suspended solids content of the lagoon effluent resulted in
erratic flows through the 30 micron microstrainer. This difficulty was particularly
noticeable during the algae growing season from May through August of each year.
Suspended solids content varied from 5-35 mg/1.
Cold water for the microstrainer sprays was initially obtained from the discharge
side of the high head pump transporting microstrained water to the filter. Due to
the introduction of high levels of chlorine immediately before the take off point,
difficulties were encountered from trichloramine fumes. Spray water take off was
moved to the storage tank fed distribution system with a resulting reduction in
chlorine fumes within the control house.
73
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'•"•v-^VC'' '
Control House Housing Microstrainer and Chlorination Equipment
During the winter months, when ice formation on the lagoon surfaces interfered
with the operation of grease skimmers, particles of grease and tissue fibers
were present in the wastewater lagoon effluent passing into the filter plant.
Increased servicing of the skimmers, on a daily basis as opposed to the initial
practice of weekly skimming, resulted in a reduction of grease content in the
lagoon effluent from 125 mg/1 to 8 mg/1.
Daily skimmer servicing resulted in the reduction of clogging of the microfilter
screens. Maximum consistert flow, however, through the 30 micron screens
never exceeded 16? gpm. Ultimately the 30 micron screens were replaced with 70
micron screens. These larger screen openings allowed a continuous flow of 300
gpm through the microstrainers with only slight decrease in effluent quality.
74
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Microstrainer - 300 Gallons Per Minute - ?0 Micron Screens
75
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Flocculation Chamber Showing Grading and Cold Water Protection
76
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Chlorination
Laboratory studies utilizing "breakpoint" chlorination were undertaken in an
effort to destroy grease. They indicated approximately 7.2 mg/1 of chlorine
was required to reduce 1 mg/1 of grease to a stable compound. At this point
in the study grease content in the wastewater lagoon effluent was approximately
15.5 mg/1, which would exert a chlorine demand of 112 mg/1. Two gas chlorinators
were used, one at the secondary lagoon contact chamber and one between the
microstrainer and the diatomaceous earth filter, each operating at 80 Ibs/day
for a total capacity of 160 Ibs/day. This rate approximated 45 mg/1 of chlorine,
compared to the 112 mg/1 required by the average concentration of grease, so
"breakpoint" was not consistently reached.
The use of highly chlorinated water in the microstrainer sprays resulted in re-
lease of excessive chloramine fumes within the control house. The problem was
reduced by supplying microstrainer sprays with water from the pressure tank.
"Breakpoint" was more consistently reached following storage in the tank.
Attempts to satisfy chlorine demand resulted in formation of an opalescence in
the filtered water. At times, when opalescence was not present in the filter
effluent, it was noticed in the filtered reclaimed water following storage in
the pressure storage tank. This opalescence was assumed to be the result of
colloidal solids which coagulated at pH ranges below 4.6 resulting from excessive
chlorine content, indicating the probability of colloidal protein being present
in the wastewater lagoon effluent. Efforts to verify the presence of protein
through the use of available laboratory capacilities, including the use of an
infrared spectrophotometer, were inconclusive.
The probability of protein is supported, however, by the nitrate nitrogen present.
Protein from animal sources normally contains approximately 16% nitrogen. There-
fore the concentration of protein present can be 6.25 times the concentration of
nitrogen. Nitrate nitrogen present in the wastewater lagoon effluent averaged
7.0 mg/1 thoughout the study. Normal nitrate nitrogen concentration of Sterling's
water supply, based on routine analyses conducted during the study, equals 2.3
mg/1. Subtracting this value from the nitrate nitrogen present in lagoon effluent
and applying the factor of 6.25 indicates a possible protein content of 29.4 mg/1:
(7.0-2.3) mg/1 x 6.25 = 29.4 mg/1 protein
Similar calculations based on total nitrogen present, as opposed to nitrate nitrogen,
would indicate increased probability of the carryover of protein through the
wastewater lagoon system.
Flocculation and Sedimentation
To eliminate problems of colloidal content, grease, and excessive solids,
additional facilities were designed and constructed to provide for flocculation
and sedimentation of wastewater effluent following microstraining and prior to
filtration. The construction was completed and the unit placed in operation in
the early spring of 1973, and was used during the remaining months of the project.
77
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Laboratory examinations and jar tests were used to determine most efficient and
effective coagulation materials. Floe formation was attained through addition of
5 grains per gallon (86 mg/l) of alum followed by the addition of an equal amount
of lime.
Optimum levels of coagulants for formation of floe, as determined by daily jar
tests, remained relatively constant throughout the study.
The diatomaceous earth filter proved to be totally inadequate for use with water
of the quality being applied. In no instance was the design volume of 300 gpm
attained.
Sand filter
During the second segment of the study the diatomaceous earth filter was bypassed
and one of the sand filters in the Sterling water treatment unit was used.
Each of the two lŁ' diameter sand filters in the Sterling water treatment unit
has sufficient capacity to filter the total demand flow for the poultry plant.
The piping to one filter was altered to allow it to be used as a standby for the
Sterling water treatment plant and also as the final filter for the project's
advanced water treatment unit. The sand filter proved capable of filtering the
applied water at a continuous rate of 300 gpm with weekly backwash.
Piping arrangement allowed water from the sedimentation basin clear well to be
pumped to the Sterling sand filter. The filtered water could then be returned
to the primary wastewater lagoon, bypassed directly to the river, or discharged
into the raw water basin of Sterling's water treatment unit.
Reuse
The Sterling plant was closed for a period of six weeks due to a labor strike.
This provided an opportunity to study problems and effects relating to the use of
reclaimed water to augment the Sterling water supply.
During this period, the Sterling plant's water treatment unit was operated at
capacity with the total volume discharged through the plant's drainage system
into the primary wastewater lagoon. Lagoon effluent was treated in the advanced
treatment unit utilizing sand filtration. Reclaimed water was introduced into
the Sterling plant supply at the rate of 100 gpm, 200 gpm, and ultimately 300 gpm.
To resolve pressure variation difficulties inherent in the interconnection of two
pressure systems, and further, to provide maximum treatment of reclaimed water,
water from the advanced treatment unit was introduced into the raw water basin of
the Sterling water treatment unit, and introduced into the poultry plant's distri-
bution system through Sterling's pumping arrangement. Continuous monitoring of the
integrated supply demonstrated the ability to maintain a free chlorine residual
throughout the system and the maintenance of a turbidity level of less than 2 (JTU).
The treatment facilities utilized during this operation are as follows:
78
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Wastewater Treatment and Advanced Water Treatment Route of Flow
Screening
V
Primary Lagoon with grease skimming
V
Secondary Lagoon with grease skimming
V
Settling
inati
Chlorination
i
Micro straining
Flocculation, sedimentation
Chlorination ( "breakpoint" )
Pressure storage
Sand filtration
^
Chlorination ( "breakpoint " )
Floccu!
V
Sand
ation, sedimentation
Itration
w
Chlorination (free residual)
Sampling and Analytical Procedures
The study provided for chemical and physical examination of samples collected
from each of five sampling points throughout the system. Samples were collected
routinely of raw wastewater, primary and secondary lagoon effluent, microstrainer
effluent, and filtered water. During the second operational segment, samples of
settled water and comparison samples of filtered water from the diatomaceous earth
and sand filters were also examined.
79
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A - Raw Poultry Waste
C = Secondary Lagoon Effluent
D = Effluent From Microstrainer
X = Flocculated - Settled Water
E = Filtered Reclaimed Water
Samples of raw wastes and wastewater secondary lagoon effluent were composited
over 2k hours and collected once each day. Grab samples were collected of the
primary lagoon effluent and from each point in the advanced water treatment unit.
Sampling procedures allowed for continuous evaluation of effectiveness of each
phase of the wastewater lagoon treatment and advanced water treatment processes.
Quality Control Procedures
Routine chemical and bacteriological examinations were conducted in the Cumberland,
Maryland, branch laboratory which operates under supervision of the Laboratories
and Research Administration of the Maryland State Department of Health and Mental
Hygiene. Specialized chemical, virology, and chromatograph examinations were
conducted in the Administration's central laboratory in Baltimore, Maryland.
80
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Ill examinations were made in accordance with the procedures established in the
following:
The Standard Methods for the Examination of Water and Wastewater,
13th Edition, 1971. Published by American Public Health Association,
and Water Pollution Control Association.
EPA Methods for Chemical Analyses of Water and Wastes, 1971.
Published by Environmental Protection Agency.
Handbook for Analytical Quality Control in Water and Wastewater
Laboratories, 1972. Published by Environmental Protection Agency.
Pesticide Analytical Manual, Food and Drug Administration
Polyelectrolyte Technique for Virus Detection as developed by
Dr. Joseph L. Melnick (Baylor University).
Chemical - Physical Evaluation
Results of chemical and physical examinations of reclaimed water throughout both
segments of the operational phase of the study show that, with the exception of
turbidity, study facilities proved capable of consistently reaching standards
established for drinking water for each characteristic studied. Facilities used
during the second segment of the study's operational phase proved capable of
producing a finished water with turbidities ranging from 1 to 3 units.
The limited period of study following completion of the settling basin did not
allow thorough evaluation of advantages of coagulant aids. Increased efficiency
of coagulation should result in more consistent turbidity control. Although
chloride content of the finished water was consistently below the allowable limit
of 3>00 mg/1, continuous recycling of this Wastewater could result in chloride's
buildup exceeding satisfactory levels.
81
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Chemical-Physical Quality of Reclaimed Water
mg/1
Drinking Water
Standard-1962
N
Turbidity (JTU)
Color
Pesticides
pH
Alkalinity
Hardness
Dissolved Solids
Chloride
Cyanide
Fluoride
Nitrate (103)
Phosphate
Sulfate
Aluminum
Arsenic
Cadmium
Calcium ,
Chromium
Copper
Iron
Lead
Manganese
Mercury
Potassium
Selenium
Silver
Sodium
5
15
500
2^0
0.2
1
\6
250
0.05
0.01
0.05
1.0
0.3
0.05
0.05
0.005
0.01
0.05
270
5U
90
16
207
101
22
158
162
8
23
89
h7
23
17
26
8
26
8
26
27
8
10
8
20
8
8
19
3.5
5
0
6.6
lOlj.
131
335
117
0
0.21
31
10
13
0.03
0.01
-------
to extend the entire length of the chlorine contact chamber.
Normal rate of application in the chlorine contact chamber for
bacteriological control has been established at 20 Ibs/day.
2. Ghlorination of settling basin effluent. Chlorine is added on
the suction side of the pump which delivers settled water to
the pressure storage tank prior to filtration. During the first
operational segment of the study, water was filtered prior to
discharge into the pressure tank. During the second segment,
water was pumped into the pressure storage tank prior to delivery
to the sand filter. This procedure provides for an additional 30
minute period of chlorine contact.
Chlorine dosage at this point is determined by chlorine demand.
Normal dosage rate is 20 Ibs/day with the objective being the
reaching of "breakpoint".
3. Pre-chlorination, Sterling water treatment raw water basin.
Rate of chlorination is 5 Ibs/day to control biological growth
within the unit and to satisfy chlorine demand of raw water.
Objective is to reach "breakpoint" and to carry a chlorine
residual onto the sand filter surface.
h- Chlorination of filter effluent. Final chlorination is provided
at the rate of 5 Ibs/day, with chlorine introduced into water
service main entering the processing plant. The objective is to
assure a chlorine residual throughout the poultry plant distri-
bution system.
Bacteriological Evaluation
Bacteriological samples were collected routinely from the overflow line from the
wastewater lagoon chlorine contact chamber to determine the reliability of
chlorination of lagoon effluent. A chlorine feed rate of 20 Ibs/day (8 mg/1)
was determined adequate to assure the discharge of effluent containing fewer
than 2i;0 fecal coliform/100 ml. At a chlorination rate of 20 Ibs/day (8 mg/l),
90% of the samples collected over a two year period contained<3 fecal coliform/100
ml.
During the study period, 352 bacteriological samples of filtered water from the
advanced water treatment system were collected and examined for coliform, fecal
strep, and total plate counts. A chlorine application rate of 20 Ibs/day (8 mg/l)
prior to filtering resulted in consistent bacteriological counts of <3 coliform/100
mlj<1 fecal strep/100 mlj and a standard plate count of ^LOO/ml. The chlorination
rate of 60 - 80 Ibs/day, necessary to reach "breakpoint" during the 66 minute
retention period in the pressure storage tank prior to filtering, provides additional
assurance of bacteriological safety of the water.
Virus Control
Examination procedures to assure the total absence of viable virus organisms in
water are not presently available. U. S. P. H. S. Drinking Water Standards - 1962,
indicate the inactivation of enteric viruses in water requires a minimum free
chlorine residual of 0.3 mg/l for 30 minutes, or 9 mg/l of combined residual and
83
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3 minutes. Chlorine was added in the wastewater lagoon contact chamber. Chlorina-
tion at this point was in sufficient amount to provide a combined residual following
30 minutes' retention. Additional chlorination, at the rate required to reach
"breakpoint" during a minimum of 60 minutes1 retention, was provided prior to
filtration.
Maryland's Laboratories and Research Administration has the capability of identifying
human enteric virus organisms in water. During the study 9 five gallon samples were
composited at random from filtered reclaimed water and examined for human enteric
virus organisms. All samples were negative. Continuous automatic monitoring and
recording of free chlorine residual was provided.
Financial Considerations
Initial cost of the two wastewater treatment units was $81|., 000, excluding land
value. Construction cost of the advanced water treatment unit, including control
house, covered sedimentation basin, 1000 feet of pipe line and equipment, was
$89,998.50, resulting in a combined construction cost of $173,998.50.
Annual cost of operating the wastewater treatment unit has been determined to be
$22,658.75- Annual cost of the advanced water treatment unit is $19,U?6.77, for
a combined annual cost of $l|.2,135.52. This is equal to a total wastewater treat-
ment and water reclaiming cost of $1.03/1000 Ibs. LWK.
SUMMARY
It is technically and economically feasible to reclaim poultry processing waetewater
to levels of compliance with drinking water standards.
Problems encountered in advanced treatment of this wastewater can be resolved
through practical application of currently available equipment and technology.
The degree of recycling of poultry processing wastewater which can be utilized
without problems remains to be seen. Evidence indicates the possibility of
buildup of chlorides. Additional attention should be given to the possibility of
virus survival and carryover of organics.
Future studies are being designed to evaluate these problems and to determine the
significance of reusing reclaimed water within the poultry processing plant.
84
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REMOVAL OP PROTEIN AND PAT
FROM MEAT SLAUGHTERING AND PACKING WASTES
USING LIGNOSULPONIC ACID
t>y
T. R. Foltz, Jr.*, K. M. Ries**, and J. Ą. Lee,
INTRODUCTION
A physical-chemical process is described herein that is
designed to remove the protein and fat from meat slaugh-
tering and packing operations. The intent is to recover
these wastes materials for their potential feed value, or
alternate use, rather than regard them as pollutants to be
treated in a waste water treatment plant.
The technical literature describes the nature of sla.ugh- '
tering or abattoir wastes and meat packing wastes as being
high strength in terms of BODc, suspended solids, grease or
fat, and nitrogen(l). The principal materials present are
proteins and fat that are animal body fluids and tissue
lost in the various operations necessary to produce edible
products. As these wastes are commonly warm, have an al-
most neutral pH, contain nutrients and are readily biode-
gradeable, various systems of biological waste treatment
have been successfully used to produce a, final effluent low
in BOD, suspended solids, and grease(2) (3) (^-). Most previ-
ously designed biological waste water treatment systems
were not designed to remove the nitrogen present, but dis-
charge limitations on nitrogen are expected to be placed on
most discharges in the future(5). Nitrogen removal repre-
sents a significant additional cost to the meat industry in
addition to technical difficulties present in currently
proposed nitrogen removal resolutions(1)(3).
A process designed for removal of protein matter from raw
wastes has the potential of directly removing the nitrogen
in its original state, thereby reducing the need to add-on
additional waste treatment operations specifically for
nitrogen control. A process using lignosulfonic acid (LSA)
*Armour Pood Company, Phoenix, Arizona
**The Greyhound Corporation, Phoenix, Arizona
***Cornell, Rowland, Hayes & Merryfield/Hill, Corvallis, Ore.
85
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treatment of proteinaceous wastes has a potential for
nitrogen removal plus potential recovery of waste water
protein for recycling as an animal feed ingredient.
BACKGROUND
The physical-chemical combining of lignosulfonic acid and
proteins in an aqueous system has been known for over 30
years (6) (7). Ąallerstein(8) in 19^-j described the re-
covery of proteins from dilute solutions using spent sul-
fite liquor at a pH of 2 to 4. The precipitating agent in
the sulfite liquor was identified as lignosulfonic acid and
a ratio of 2 parts lignin to 5 parts protein was observed
to be optimal. Pearl(9) discussed the uses of lignin in a
survey paper in 1957> and mentioned the reaction of ligno-
sulfonic acid with proteins to form insoluble complexes and
indicated this reaction was used to remove proteins from
effluents of canneries or fish-processing plants.
In 1968, a U.S. Patent(10) was issued to Leif Jantzen of
Oslo3 Norway, assignor to Arthur C. Trask and Sons, Chicago,
that described a method of purifying an aqueous protein-
containing liquid by adding lignosulfonic acids to effect
precipitation of combined protein-lignosulfonic acids and
separating the precipitate.
In a paper by T^nseth & Berridge(ll), lignosulfonic acid
precipitation of proteins from various industrial waste
waters, including slaughterhouse wastes was reviewed. Sul-
fite lye (spent sulfite liquor), wa,s compared to lignosul-
fonic acid as precipitating agents on blood albumen solu-
tions, showing the lignosulfonic acid to be superior. Fer-
ric chloride was also compared, and performance was poorer
than with lignosulfonic acid.
Pilot plant trials on poultry wastes were described by
Rosen(12) using pilot plant equipment developed by Alwatech
A/S, an Oslo, Norway based firm of water treatment engineers
BOD removals ranging from 60 to 95 percent were reported,
a,nd economic aspects were also discussed.
Jg(rgensen(13) in Denmark, in a series of laboratory scale
tests compared protein precipitation with the following
chemical agents:
Control (no agent used)
Sulfuric Acid
Aluminum Sulfate
Glucose Trisulfate
Sulfite Liquor
86
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Lignin Sulfonic Acid (LSA)
Glucose Trisulfate plus Azoprotein
He observed that lignin sulfonic acid was more effective in
protein removal than the other chemicals. The protein pre-
cipitation with glucose trisulfate plus azoprotein gave a
lower residual BOD and the recovered protein had better
feed value than with lignin sulfonic acid. Aluminum sul-
fate while less effective on nitrogen removal, was found
effective for phosphate removal.
Hopwood and Rosen(l4) reported further developments by
Alwatech A/S, and described the "Alwatech process" wherein
purified sodium lignosulfonate called "Alprecin" can be
used at pH 3 to recover protein and fat from various indus-
trial wastes. Pilot plant data was reviewed, from studies
using Alwatech dissolved-air flotation equipment.
Since 1970 Alwatech A/S has marketed equipment and tech-
nology in Europe for recovery of proteins from wa,ste water
on an industrial scale. To date, several plant scale
installations of Alwatech equipment have been completed and
are in operation in Sweden and England. There are currently
no plant scale installations in operation in the United
States.
THEORY
The precipitation of soluble protein with soluble lignosul-
fonic acid in an acidic aqueous system is believed to be a
nearly instantaneous reaction involving the negatively
charged sulfonate groups on LSA molecules and positively
charged amine groups present on the protein molecules. The
complexing of these large molecules results in a gelatinous
suspended material that can be removed by a suitable physi-
cal liquids-solids separation technique.
Protein molecules contain both positively cha,rged amine
groups and negatively charged carboxyl groups when the solu-
tion is at pH values near 7. Acidification of proteinaceous
waste water to pH values below the isoelectric point will
result in proteins carrying a net positive charge. Isoelec-
tric values vary with different proteins, but acidification
to 3.5 or below normally insures a pH below the isoelectric
for most protein solutions.
Lignosulfonic acid when in solution has the sulfonate group
essentially completely ionized, resulting in a net negative
charge on the LSA molecule. With acidification, the strong
acid group of the sulfonate continues to carry a negative
87
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charge even at pH values of 2 to 3. At extremely low pH
values below 1, the sulfonate group begins losing its
charge.
Table I summarizes the respective net charges on LSA and
protein molecules at various pH ranges, noting the re-
sulting precipitation potential.
Table I. Influence of pH on LSA-Protein Precipitation
r>H Range Protein LSA Precipitation
0-1 Positive Charge Ąeak Negative Poor
Charge
2-3 Positive Charge Negative Charge Good
3-5-4.5 Isoelectric Negative Charge Poor
(no net charge)
Above 4.5 Negative Charge Negative Charge None
This table reveals that the pH must be in range of 2 to 3
to obtain effective precipitation. Actual experimental
evidence confirms that this is the optimal pH range for
precipitation of the maximum amount of protein.
Because the precipitation involves balancing of opposite
ionic charges, it follows that an optimal ratio exists
between LSA and proteins in order to maximize protein re-
moval with the least amount of LSA. Experimental evidence
also confirms that treatment of proteinaceous wastes with
LSA is quantitative, making LSA dose control important(15).
In precipitating and removing the LSA and protein complex,
fat and fatty material (as determined by hexane soluble
extraction) are also largely removed. In raw waste, fat is
primarily particulate and emulsified matter with a free
fatty acid content ranging from 5 to over 50 percent of the
total fat content. Acidification of raw wastes eliminates
the strong negative charge on the free acid carboxyl groups
resulting in a loss of water solubility. Therefore, at
protein precipitating pH values, most of the fat material
tends to separate from the water and float to the surface.
The presence of LSA would not be expected to enhance fat
removal if protein matter was absent from the raw wastes.
88
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With protein present and forming an insoluble material with
LSA, the fat tends to be comingled with the protein-LSA
material.
LIGNOSULFONIC ACID (LSA)
Lignosulfonic acid is a by-product from the sulfite wood
pulping industry and is commercially available in a variety
of forms and quality.
Spent sulfite liquor contains wood lignin that has been
made soluble by the introduction of sulfonate groups in the
lignin. Sulfonated lignins are large molecules made up of
repeating units of polymerized coniferyl alcohol, together
with lesser amounts of sinapyl and p-coumaryl alcohols.
(Sinapyl alcohol contains two aromatic methoxyl groups while
p-coumaryl alcohol has none.) Approximately half the coni-
feryl units are sulfonated, primarily on the aliphatic car-
bon attached to the aromatic ring(l6). Figure 1 illus-
trates a typical segment of sulfonated lignin. The term
"lignosulfonic acid," or LSA, is herein used to describe
the sulfonated lignin matter as present in an aqueous system,
which is ionized as shown in Figure 1.
The molecular weight of lignosulfonic acid is not a defined
quantity as the commercially available materials are
actually mixtures of various molecular weight lignins.
Jantzen(l?) described the desirability and method of sepa-
rating lignosulfonates into two molecular weight fractions
and defined them as follows:
Name of LSA Fraction Average Molecular Weight
Alpha acid 14,620
Beta acid 5,l8o
In protein precipitation, the higher molecular weight frac-
tion is more suitable than low molecular weight LSA(l8).
Spent sulfite liquor is over 50 percent LSA on a dry weight
basis, and is functionally capable of precipitating pro-
teins. However, spent sulfite liquor contains carbohydrate
matter that contributes soluble BOD to the protein solution
being treated, and is an undesirable precipitant for this
reason.
Desugared sulfonated lignins are commercially available
from several mills that are better candidate precipitants
for waste water protein than spent sulfite liquor. More
highly purified lignosulfonic acid is the most suitable
89
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CH,0
OH
H
HCOH
-CH
HC-SOJ"
CH30
H
HCOH
I
-CH
CH CH,0
Ix.^ 1
Y
C=0
1
n U
U H
H-C-S03
H
Figure 1. Typical Segment of Sulfonated Lignin Molecule
90
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material to use as the nrecipitating chemical3 especially
products that havg mainly high molecular weight LSA.
LSA products are available in the salt form such as sodium,
calcium, or ammonium lignosulfonate. As the ca.tion is not
involved in precipitation, the choice of salt form is
dictated by reasons other than precipitation performance.
Ammonium lignosulfonate would be clearly unsuitable in
applications where nitrogen removal was an objective.
LSA is available as a dry powder bagged in 50 Ib. bags or
as a. bulk liquid at about 50 percent total solids.
It is important to note that LSA is not a standard chemical,
but ra.ther a complex mixture of sulfonated lignins plus
minor wood extract impurities. Differences in the woods
used, method of cooking, and subsequent handling will affect
the properties of LSA.
In application LSA is used as a stock solution at about 10
percent total solids, which makes a blackish-brown liquid
that is easily handled and pumped.
Lignin sulfonates are FDA approved for use in animal feed
as described in the Code of Federal Regulation,
21CFR121.234.
PILOT PLANT TESTS - GREEN BAY
A brief pilot plant study was conducted at a. beef abattoir
in Green Bay, Wisconsin, to evaluate the LSA precipitation
and removal of protein and fat under actual plant conditions,
Arrangements were made through the Arthur C. Trask Corpora-
tion in Chicago to have Alwatech A/S of Oslo, Norway, deli-
ver and operate a small pilot plant for a, period of several
weeks. The test program was designed to demonstrate the
optimum pollutant removal capability of LSA and to charac-
terize the protein matter separated.
The plant operations contributing waste waters consisted of
typical beef kill floor operations, paunch manure screening,
inedible dry rendering, blood drying, and hide curing.
Sanitary wastes, livestock pen wastes, and refrigeration
cooling water flows were handled separately and were not
present in the raw plant wastes. The fresh raw wastes were
pretreated by screening in a North Screen. A 20-gallon per
minute side stream from the screen effluent was pumped to
the pilot unit as the raw waste to be treated.
The pilot plant consisted of an influent pump, partial
91
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influent pressurization to 75 psig, chemical feed systems
for sulfuric acid and LSA, and a circular dissolved-air
flotation tank having a 6o-minute theoretical detention time.
Figure 2 illustrates a schematic of the pilot plant equipment.
Air was provided by a small compressor to provide air for
dissolving into the pressurized influent. Sludge scrapers
were present for floating solids removal from the flotation
cell. The flotation unit effluent was not neutralized and
was considered the effluent from the pilot unit.
Sulfuric acid, technical gra.de, was metered as a 1 percent
solution and powdered LSA was made up as a 10 percent feed
solution for metering into the process. Figure 2 illus-
trates a schematic of the pilot equipment employed.
Beaker tests were first performed to establish anticipated
pH and LSA dose ranges to be studied in the pilot operation.
Actual pilot plant runs for sampling were conducted after a
minimum of one-half hour of continuous normal operation, with
the flotation tank already filled with chemically treated raw
waste water remaining from the previous run. The pilot runs
lasted a minimum of four hours per run, and all sampling was
on a composite basis.
Nine reported runs were conducted using a powder LSA called
"Na-Peritan" which was supplied by Arthur C. Trask Corpor-
ation from sources in Norway. This product was a purified
sodium salt of lignosulfonic acid that contained very little
residual wood sugar and was a high molecular weight fraction
of LSA. Table II summarizes the data from these nine runs.
Two other LSA products were also evaluated druing the pilot
trials; an ammonium salt of LSA and a sodium salt of LSA,
both experimental products from Scott Paper Company. Typical
runs for these products produced roughly similar results
except total nitrogen removal was poor for the ammonium LSA.
Acid addition and LSA dose were varied by the Alwatech opera-
tor to achieve good visual performance without regard to
arriving at the economically minimum chemical requirement.
While a precipitating pH of 3-^ was experimentally found to
be suitable for effective precipitation, the average pH for
all runs was 2.6, with one run as low as 2.0. Good precipi-
tation was found at this pH range, but excess acid was used
that would not be representative of full plant scale opera-
tion.
The LSA dose range tested was 244 to 537 mg/1, which repre-
sented a range of effective precipitation rather than a
92
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range of minimum dose to achieve adequate precipitation.
As Table II illustrates, effective pollutant removal was
accomplished in terms of BOD. suspended solids, fat or
grease, and total Kjeldahl nitrogen. The pilot plant out-
performed the existing plant scale dissolved-air flotation
unit in service at the abattoir as summarized in Figure 3-
Samples of the recovered raw sludge were withdrawn and ana-
lyzed by the Armour and Company Pood Research Laboratory in
Oakbrook, Illinois. Table III summarizes the analytical
values for the LSA sludge, and Table IV compares the amino
acid profile of the LSA sludge as compared to soybean oil
meal and casein. These analyses reflect raw sludge solids
characteristics and are not necessarily representative of a
final product as produced on a plant scale.
PLANT SCALE OPERATION - SUTTON BENGER
A one-day visit was made to observe the operation of a plant
scale installation of Alwatech equipment at a poultry plant
in England in November, 1972. This plant was designed for
approximately 753000 broilers per day, and was located at
Sutton-Benger, near Chippenham, in Wiltshire, England.
Typical of broiler plants in the United States, this plant
had rotating screens on each of the offal flow-away waste
water and feather flow-away waste water sewers. This plant
had an older industrial waste treatment facility consisting
of primary clarification, trickling filters, final clarifiers
and humus tanks prior to final river discharge.
The newer Alwatech equipment consisted of the following:
1. Balancing tank to receive screened raw wastes.
2. Precipitation and flotation system, designed
for 400 gallons per minute flow.
3. Neutralization system.
^-. High rate trickling filters with plastic media,
5. Final clarifiers.
The Alwatech system provided primary waste water treatment
and the effluent was then subsequently treated in the
existing older secondary treatment plant final to river dis-
charge.
After balancing the flow to dampen fluctuations in flow and
waste water strength, the raw waste was initially dosed with
approximately l4o mg/1 of Alprecin (LSA). Once the dosage
was set, this dose was held constant and no changes in LSA
dose were needed from day-to-day or hour-to-hour. The flow
95
-------
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Table III: Analysis of LSA Sludge from Pilot Plant
Studies, Armour and Company, Green Bay,
Wisconsin
Item Percent of Dry Matter
Protein 40.2
Fat 24.08
Crude Fiber 4.29
Lignin Sulfonate SI.62
Total Solids 100.00
Total Nitrogen 6.43
Total Non-protein Nitrogen 0.503
Sodium 0.359
Potassium 0.042
Calcium 0.054
Magnesium 0.0083
Phosphorus 0.398
Sulfur 1.55
Iron 0.169
Copper 0.0025
Manganese 0.022
Zinc 0.0066
Vitamin A (including carotene) IU 58ll
97
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Table IV: Amino Acid Profiles for LSA Sludge (Green Bay
Pilot Study), Soybean Oil Meal and Casein
Amino a.cids
Lysine
Threonine
Valine
Methionine
Isoleucine
Leucine
Phenylalanine
Tryptophan
Histidine
Arginine
Aspartic acid
Serine
Glutamic acid
Proline
Glycine
Alanine
Cystine
Tyrosine
LSA
Sludge
gm of amino
acid per 16
gm of N
9.77
5.75
8.05
1.67
4.19
11.74
6.17
1.32
4.82
5.49
12.49
5.42
14.70
5.16
5.83
8.23
3.80
Soybean oil
meal
gm of amino
acid per 16
gm of N
6.30
3.70
5.23
1.30
5.45
7.40
4.80
1.30
2.40
7.00
n.4o
4.70
19.30
4.70
3.80
4.30
1.70
3.05
Casein
gm of amino
a,cid per 1(5
gm of N
8.5
4.2
6.5
M
5.8
9.0
5.1
1.4
3.2
3.6
6.7
6.7
22.5
12.3
2.1
3.2
0.3
98
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was then split into three flows. Two equal main flows were
regulated by flow controllers for delivery to each of two
dissolved-air flotation units. The third flow, approximately
15 percent of the incoming total flow, was pressurized to
75 psig, saturated with air, and then split into two equal
flows to deliver dissolved air to the two main influent
streams.
Just prior to entry into the flotation unit, the waste water
was mixed with the side stream of waste water with dissolved
air, and a one percent solution of sulfuric acid was a.dded
to depress the mixture from pH 7 to pH 3- In one flotation
cell, the raw waste pH was monitored, with the electrodes
being cleaned by a timed ultrasonic generator. The pH was
continuously recorded and a control function automatically
actuated the sulfuric acid feed pumps to maintain a pH
3.0 ^ 0.3. The normal sulfuric acid dose was 250 mg/1.
The flotation units were circular 18 ft. diameter fiberglass
tanks with surface scrapers consisting of a vacuum suction
system for sludge removal. The clarified effluent from the
two flotation units were combined and delivered to a small
mixing tank where hydrated lime was added at the rate of
about l80 mg/1, and automatically pH controlled to 7-0 "t 0.5.
The neutralized waste was then subjected to biological treat-
ment in the subsequent trickling filter system.
Sludge from the two flotation cells was accumulated in an
existing pit and hauled away for land disposal as a temporary
measure. It was understood that studies were then underway
to utilize the recovered sludge as an animal feed component.
The entire precipitation a.nd flotation system plus chemical
handling was housed in a building to reduce the influence of
weather on plant operations.
Pilot plant data in establishing the design of Alwatech
equipment revealed that on the raw wastes of 1,000 to 1,500
mg/1 BOD, the removals observed were as follows:
BOD removal 73-8$
COD removal 76.3$
TSS removal 82.7$
64.3 to 80.5 range
70.6 to 86.8 range
75-6 to 89.2 range
No plant operating results were available for review at the
time of visit, but visual performance in producing a clear
effluent after flotation suggested the pilot plant data was
duplicated in the actual plant scale operation.
99
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The subsequent biologica.l treatment of the precipitation and
flotation effluent was reported successful in meeting the
final effluent standards of 30 mg/1 BOD and 40 mg/1 Suspended
Solids.
No difficulties in operation of the entire system were ob-
served during the visit. Plant operator functions consisted
of maintaining all equipment in good working order and in-
suring adequate chemica.ls are available to the chemical feed
systems.
PLANT SCALE OPERATION - KALMAR
A brief visit was made to another installation of Alwatech
equipment that used LSA treatment of meat industry wastes.
As in the case of Sutton-Benger, the primary goal was BOD,
grease, and suspended solids reduction, with the intent of
recovering a by-product. Nitrogen removal was not a specific
objective.
This facility was a complex packing plant in Kalmar, Sweden,
that slaughtered beef, hogs, and a minor number of lambs,
horses, and elk. A wide variety of sausages, smoked meats,
a,nd other processed meat products were produced. Canning
operations included canned meat products and some canning of
vegetables, with pea.s and carrots being processed at the
time of visitation in November, 1972.
The waste water treatment system in operation consisted of
the following:
1. Grease skimming basin converted into a balancing
tank.
2. Rotary screen (1/8 inch diameter openings) pre-
treatment.
3. Precipitation and dissolved-air flotation system.
4. Neutralization system.
The final treated effluent was then discharged to the Kalmar
municipal sewerage system for joint treatment with domestic
wastes.
The precipitation and flotation processes were operating at
a, design flow of about 400 ga.llons per minute on ea,ch of
three out of the five working days. On the remaining two
working days, reduced operations produced a raw waste flow
of about 265 gpm.
Screened waste was dosed with a constant dose of 220 mg/1
Alprecin (LSA). As at the Sutton-Benger installation, man-
ual control of the LSA dose rate was found effective in
100
-------
maintaining proper precipitation. The LSA was fed as a ten
percent stock solution with the feed rate proportional to
the total waste flow. Unusually high strength shock loads
with BOD values well above 2,000 mg/1 did require upward
adjustment of the LSA dose, but this problem was considered
infrequent, and one best controlled by improving inplant
operations.
The LSA dosed screened waste was split into the 15 percent
side stream for influent pressurization and air dissolving,
while the major flow was equally split for delivery to the
two 18 ft. diameter fiberglass flotation cells. Sulfuric
acid addition and re-entry of the dissolved-air side stream
took place just prior to entry into the flotation tanks.
The pH was monitored, recorded, and controlled at pH 3-0 by
automatic adjustment of the sulfuric a,cid feed pumps. Sul-
furic acid dose was typically about 350 mg/1. The flotation
effluent flowed by gravity to a neutralization tank for
adjustment of pH to 7.0. A lime slurry was pumped to the
neutra.liza.tion tank and wa.s manually set for about l80 mg/1
hydrated lime. With manual adjustment of neutralization,
the recorded final pH fluctuated between pH 6 and 8.
Sludge accumulating in the flotation ta.nk wa.s scraped into
four radial troughs at the sludge surface, using a timed
motorized scraper making two sweeps in three minutes fol-
lowed by three minutes off-time. The sludge normally was
about ten percent total solids and was pumped to a, storage
tank.
At this plant, edible blood was being recovered and used in
processing. Residual collected blood wa.s mixed with the LSA
sludge in the sludge storage tank and the mixture was heated
to about 50°C. The heated sludge and blood mixture was then
subjected to live steam to coagulate the protein ma.tter.
This mixture wa.s then dewatered by a solid bowl centrifuge
which produced a granular solid of about 4o~5D percent dry
matter. The centrate was recycled ba.ck to the raw waste
balancing tank. The recovered solid wa.s then added to the
main plant continuous inedible rendering system for final
drying a.nd recovery with inedible tallow a.nd cracklings.
Table V summarizes BODy removal based on influent samples
prior to the raw wa,ste sc
flotation unit discharge.
/
prior to the raw waste screen and effluent samples at the
At the time of visitation, this plant had very little repre
sentative data on the nitrogen removal achieved in the pre-
cipitation and flotation equipment. Alwatech engineers con
ducted a. brief study to provide the data a,s summarized in
Table VI(l8).
101
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Table V: BOD Removal at Kalmar(l8)
Influent BOD7. mg/1 Effluent BOD,-., mg/1 Percent Removed
' ^
1200 360 70.0
1500 300 80.0
1360 330 75.8
1440 370 7^.3
1290 220 83.0
1100 150 86.0
1700 300 82.0
1600 320 80.0
2100 3^0 83.8
1950 380 80.5
1500 380 7^.6
1700 270 84.0
1750 3^0 80.6
Avg. 1553 312 79.9
102
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Ta,ble VI: BOD and Nitrogen Removal at Kalmar(l8)
Test Number _ 1234567 Avg.
BOD: Inf. mg/1 1290 1100 1700 1600 2100 1950 1750 l622
Eff. mg/1 220 150 300 320 340 380 340 300
83 86 82 80 84 8l 8l 82
TKN: Inf. mg/1 91 77 119 112 147 136 122 11 4
Eff. mg/1 24 18 32 33 38 40 35 32
% Rem. 77 77 73 71 74 71 71 73
TS: Inf. mg/1 3088 2855 2564 3607 3138 4129 3216 3117
Eff. mg/1 3174 2569 2605 3173 31^0 4012 30Q4 2981
Notes: Influent excluded rumen cleaning and gut-cleaning
waters, samples just prior to flotation. Effluent
downstream of neutralization.
103
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CONCLUSIONS
1. Lignosulfonic acid treatment of meat industry waste
waters under acidic conditions, followed "by dissolved -
air flotation is capable of removing significant
quantities of BOD, suspended solids, grease, and nitro-
gen from raw wastes, as demonstrated in pilot plant and
plant scale installations.
2. LSA treatment appears suitable as a pretreatment step
to final biological treatment. It is therefore a can-
• didate process for both meat industry plants using
municipal sewerage systems and in cases where the in-
dustry must treat its own waste water.
3. Removal of protein and fat with LSA offers the poten-
tial of a recovered by-product that may have value as
a component in animal feed. This would eliminate a
problem of ultimate disposal of the materials removed.
4. The physical-chemical nature of the process makes it
convenient to rapidly start-up the process when needed,
and to stop processing when desired.
5. The process requires very little land area, and if
housed, will operate indpendent of weather effects.
6. The process appears best applied to very fresh raw
waste of high protein content and where inedible ren-
dering operations can be used to handle the recovered
dewatered sludge. Waste waters having a. low buffering
capacity are advantageous as acid and neutralization
chemical requirements are reduced.
7. Various LSA products are commercially available from
several suppliers that are suitable for protein pre-
cipitation.
104
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References
1. ERICKSON, E. E., PILNEY, J. P., and REID, R. J.
Development Document for Effluent Limitation Guide-
lines and Standards of Performance for the Meat
Packing Industry. Prepared for the U. S. Environ-
mental Protection Agency under Contract No. 68-01-0593:
(1973).
2. STEFFEN, A. J. Treatment of Packing Wastes-Practices
and Trends. Ontario Industrial Waste Conference: 27
(1966).
3. BELL-GALYARDT-WELLS. Upgrading Meat Packing Facili-
ties to Reduce Pollution-Waste Treatment Systems.
Environmental Protection Agency Technology Transfer
Program, Job No. 730105: (1973).
4. McKINNEY, R. E., editor. 2nd International Symposium
for Waste Treatment Lagoons. Distributed by Univer-
sity of Kansas, Lawrence, Kansas: (L970).
5. WITHEROW, J. L. Waste Treatment Systems for the Small
Packer. The National Provisioner: 8 (Sept. 1973).
6. GUSTAVSON, K. H. Svensk Papperstidn 44: 193 (1942).
7. WILSON, J. A. and FORTH, I. H. J. Am. Leather Chemists
Assoc. 38: 20 (1943).
8. WALLERSTEIN, J. S., PARSER, E., MAENGWYN-DAVIES, G. D.,
and SCHADE, A. L. Recovery of Proteins from Wheat
Mashes with Sulfite Waste Liquors. Industrial and
Engineering Chemistry 36: 772 (1944).
9. PEARL,I. A. Present Status of Chemical Utilization of
Lignin. Forest Products Journal 7: 427 (Dec. 1957).
10. JANTZEN, L. Protein-Rich Peed Material and Method of
Making. U. S. Patent No. 3,390,999: (July 2, 1968).
11. T0NSETH, E. I. and BERRIDGE, H. B. Removal of Proteins
from Industrial Waste Waters. Effluent and Water
Treatment Journal: (March 1968).
12. ROSEN, G. D. Profit from Effluent. Poultry Industry:
(April, 1971).
105
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13. J0RGENSEN, S. E, Precipitation of Proteins in Waste
Water. Vatten 1: 58 (1971).
14. HOPWOOD, A. P. and ROSEN, G. D. Proteins and Pat
Recovery from Effluents. Process Biochemistry: 15
(March 1972).
15. CLAGGETT, F. G. and WONG, J. Salmon Canning Waste-
Water Clarification, Part II. Circular No. 42,
Fisheries Research Board of Canada: (Feb. 1969).
l6. BALL, F. J. Chemistry of Lignin and Its Applications,
Presented at APPA-TAPPI Research Conference:
(Oct. 1965).
17. JANTZEN, L. Method of Separating Lignosulfonic Acids,
U.S. Patent No. 2,838,483:(June 10, 1958).
18. T0NSETH, E. I. Personal Communication (1972).
106
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DESIGN CONSIDERATIONS FOR TREATMENT OF MEATPACKING
PLANT WASTEWATER BY LAND APPLICATION**
Anthony Tarquin*, Howard Applegate*,
Frank Rizzo*, and Larry Jones*
INTRODUCTION
The increasing demands being placed on municipalities and industries to
remove residual carbon, nitrogen, and phosphorus from wastewater discharges
has stimulated interest in the land application method of wastewater treat-
ment. The purpose of this paper is to present some initial observations
from pilot studies on the suitability of treatment of meatpacking plant
wastewater by land application. Land application of wastewater produces
high quality effluents from high BOD wastes with relatively low investment
and operating costs. The trend toward standards which allow discharge of
wastewaters with only low concentrations of carbon and little or no nitro-
gen and phosphorus has had a particularly hard impact on those industries
which generate wastewaters that have high concentrations of these materials.
Thus, when an industry produces a wastewater with a BOD of 1000 mg/&, good
secondary biological treatment with even 95 percent overall efficiency
would still result in a discharge with a BOD of 50 mg/Jl. Additionally,
most of the nitrogen and phosphorus that was present in the untreated
wastewater would remain in the effluent. High quality effluents could be
achieved with tertiary methods, but the cost of wastewater treatment would
be increased considerably. The meatpacking industry is one of the indus-
tries that generates wastewater with extremely high concentrations of car-
bon, nitrogen, and phosphorus.
BACKGROUND
The research described in this paper is a three-year pilot-demonstration
project that began June 1, 1972 at the Peyton meatpacking plant located in
El Paso, Texas. The first two years of the project will involve pilot
*Dept. of Civil Engineering, University of Texas at El Paso
**This project is supported by funds from the Environmental Protection
Agency under Grant No. 801028 and John Morrell Co., Chicago, 111., and
the University of Texas at El Paso.
107
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testing of four separate wastewater application areas treating a total of
about 40,000 gpd. Full scale demonstration is planned in the third year
of the project.
The system has been in operation for approximately eight months spanning
part of the cool winter season and the hot summer months. Rainfall in the
El Paso area is scanty, averaging about seven in. per year, with most of
the rainfall coming in the summer months through brief but heavy thunder-
showers .
MEATPACKING PLANT WASTEWATER CHARACTERISTICS
Meatpacking plant wastewater contains most of the pollutants found in do-
mestic wastewaters, except that their concentrations are five to ten times
higher. For the most part, meatpacking plant wastes are amenable to treat-
ment by all conventional secondary biological methods. When high concen-
trations of grease are present, however, problems with sludge settling can
be encountered with the activated sludge process.
At the Peyton packing plant the effluent flows into a rectangular sedimen-
tation - skimming tank (catch basin) which has a detention time of 30 min.
at peak flow. The efficiency of the tank for BOD, COD, and grease removal
has averaged about 66 percent. Nitrogen, phosphorus, and total solids
removals have been considerably less. Table 1 shows the average results
of some of the analyses performed on the effluent from the catch basin.
Table 1 - Catch Basin Effluent
Analysis Avg. Conc.,mg/Ł Range,mg/&
Grease 1400 285 - 8160
BOD 1340 200 - 115,000
COD 4180 307 - 160,000
P 17 3-35
Kjeldahl-N 124 27 - 1200
Total Solids 4200 950 - 13,980
108
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The rather large range for most of the parameters is a manifestation of
a daily killing and clean-up cycle. As expected, the strongest wastes are
observed during the killing operations and early clean-up hours. The waste-
water volume varies similarly, with the maximum flow occurring during kill-
ing hours, tapering off to a very small flow after midnight.
Design Considerations
Many factors must be taken into consideration in the design of a soil
treatment system for wastewater treatment, including the geology of the
area, type of soil, permeability of the soil, wastewater characteristics,
and soil cover.
The wastewater treatment area at the Peyton packing plant is flat land com-
posed of 12-24 in. of sandy clay loam underlain by fine sand. The charac-
teristics of the wastewater dictated that only small volumes could be ap-
plied at any one application if odors due to an aerobic conditions were to
be avoided. Therefore, a sprinkler infiltration type system was designed
and constructed. This is in contrast to soils having low vertical infil-
tration rates that would be more adaptable to a flooding basin infiltration
system (1) or to spray runoff treatment (2,3). If a flooding basin system
is used, however, a rapid flooding rate would be required in order to equal-
ize the hydraulic loading on the soil. When a sprinkler irrigation system
is required, the minimum nozzle size should be 3/8 in. dia., with 1/2 in.
dia. or greater preferable. The larger nozzle sizes minimize clogging due
to manure and bone fragments that are sometimes present in the wastewater.
Regardless of which type of system is used (infiltration or runoff) some
type of soil cover is preferable. Ideally, the most suitable soil cover
for a meatpacking plant wastewater would possess the following characteris-
tics: High moisture tolerance, high salt tolerance, resistance to high
sodium concentrations, high nutrient uptake, and long growing season. In
the south and southwestern part of the United States, grasses that do well
under these conditions are Bermuda (common or NK-37), tall wheat, tall fescue,
and blue panicum. Leafy plants are not as desirable as grasses because of
leaf damage from the high total dissolved solids concentration. In addi-
tion, the high total dissolved solids concentration usually makes it advan-
tageous to irrigate with low total dissolved solids (TDS) water until the
seeds have germinated and the grasses have grown at least one inch tall.
RESULTS
The results obtained in relatively short term operation are very encour-
aging from the standpoint of treatment efficiency. At hydraulic loadings
of up to 4 in./week, COD removals have consistently exceeded 90 percent in
the first three in. of soil with greater than 99 percent removal through
four feet. Table 2 summarizes results obtained at the four-foot sampler
depth at a wastewater application rate of about four in./week.
109
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Table 2 - Short-term Treatment Results
Parameter Average Removal, % Range of Removal,:
COD 99 92 - 100
Grease 100 100
Nitrogen 50 30 - 95
IDS 25 - 50 increase due to evaporation
The grease present in the original wastewater is separated very quickly
after application of the wastewater to the soil. Although the organic con-
centration of the soil in the treatment areas has increased, there has been
no measurable build-up of grease up to this time. Studies are currently
underway to determine the rate of grease decomposition and the decomposition
products.
Nitrogen removal has varied considerably, depending on the frequency of
application. Generally, better nitrogen removals have been obtained with
flooding rather than through several small applications/week. The nitrogen
is present in the treated samples in nitrate form only, indicating a high
degree of nitrification. Higher organic loads could therefore be tolerated,
causing lower dissolved oxygen concentrations in the soil water and possible
nitrogen loss through denitrification.
The TDS concentration of the wastewater increased considerably on passage
through the soil. The low humidity in combination with high summer temper-
atures results in concentration of the dissolved solids through evaporation.
The only detrimental effect observed thus far due to the high TDS concen-
tration of the soil water has been depressed germination of various grasses.
The removal of phosphorus by the soil system was initially very high, i.e.,
greater than 99 percent. At the present time, however, very little phos-
phorus is being removed in the spray areas that have been in operation the
longest. It appears that the initial available absorption sites have been
filled and a slower chemical reaction is now removing small amounts of
phosphorus (4). This was expected, however, since the topsoil at the
Peyton plant is a maximum of 24 in. thick and contains over 56 percent
sand and only 10 percent clay.
110
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Discussion
There are several potential problems associated with land application of
meatpacking plant wastewater. One of the most serious is the possibility
of the presence of pathogenic bacteria in the wastewater. Brucellosis,
Salmonella, and Shigella bacteria have been isolated from the effluent of
the catch basin. Brucella organisms can survive for long periods of time
in the soil and are capable of infecting both man and animals. A more
thorough investigation is now under way at the Peyton site, but the problem
warrants serious consideration in the handling of all meatpacking plant
wastes.
The problem of pathogenic bacteria present in the wastewater is compounded
by the drifting of aerosols formed during application of the wastewater.
Under even slight wind conditions (5-10 MPH), aerosols can be observed to
drift up to 500 feet. Under the same conditions, a bacterial spore could
conceivably drift for miles.
The presence of manure and bone fragments in the wastewater necessitates
using rather large nozzles. Since large nozzles require higher pressures
for equal distribution when using impact type sprinklers, the problem of
drifting is almost unavoidable. An alternative to impact sprinklers is a
moving distributor which operates a low pressure using large nozzles. The
suitability of this type of system is now under investigation at the Peyton
site.
The high TDS concentration in most meatpacking plant wastewaters is caused
by sodium chloride. As a result, most packing plant wastewaters have a
very unfavorable sodium absorption ratio. This would cause serious problems
with infiltration in clay-containing soils unless amendments were added.
Sandy type soils are generally not affected by unfavorable sodium adsorption
ratios and therefore are generally best suited for accepting meatpacking
plant wastes as they leave the plant.
Finally, the high concentration of nitrogen present in most meatpacking
plant wastewaters presents a potential problem of ground water pollution.
The experience gained with soil treatment systems so far indicates that
close control of the treatment system is required in order to remove greater
than 50 percent of the nitrogen. Even then, the high concentration origi-
nally present could cause significant amounts of nitrogen to reach the
ground water table.
CONCLUSIONS
Based on the results from relatively short-term operation, the following
conclusions can be made with reasonable certainty:
(1) Virtually all of the organic carbon can be removed from meatpack-
ing plant wastewater by a properly operated soil treatment system.
Ill
-------
(2) While high concentrations of grease seem to pose no problem in
short term land application of meatpacking plant wastewater, the long term
effects of grease on the wastewater infiltration rate bears watching.
(3) In order to achieve high nitrogen removals, the system must be
designed to allow close control of the hydraulic and process loads, and
(4) Special consideration should be given to the following potential
problems:
(a) possible presence of pathogenic bacteria in the wastewater.
(b) aerosol drifting due to high pressure sprinkler application.
(c) a very unfavorable sodium absorption ratio, and
(d) ground water pollution from high concentrations of
nitrates.
112
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1. BOUWER, HERMAN, RICE, R.C., and ESCARCIGA, E.E. Renovating
secondary sewage by ground water recharge with infiltration basin.
Office of Research and Monitoring, EPA, Project no. 16060DRV,(1972).
2. LAW, JAMES and THOMAS, R.E. Nutrient removal from cannery wastes by
spray irrigation of grassland. U.S. Dept. Interior, Water Pollution
Control Research Series: 16080 (11/69).
3. WITHEROW, JACK Waste treatment evaluation. The National Provisioner,
169:40 (1973).
4. CHEN, Y.S.R., BUTLER, JAMES, and STUMM, WERNER. Kinetic study of
phosphate reaction with aluminum oxide and kaolinite. Environmental
Science and Technology, 7: 4 (1973).
113
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CLEANING AND LYE PEELING OF TOMATOES
USING ROTATING RUBBER DISCS
by
R. P. Graham
PRELIMINARY INVESTIGATIONS
At the Western Regional Research Center (WRRC) of the Agricultural
Research Service, USDA, we have studied various methods of peeling
caustic treated vegetables and fruits to reduce the amount of peeling
waste which normally enters plant effluent waters. As a result of
these studies we have developed a rubber disc machine to be used for
peel removal in place of conventional hydraulic washing. Studies on
the use of rubber disc machines for cling peach peeling have shown
substantial reduction in water pollution and consumption. Although
studied primarily for peeling peaches the rubber disc machines have
since found additional uses.
The commercial use of rotating rubber disc machines for peeling
caustic-treated fruit was undertaken in a number of plants during
the 1972 season, about half of them operating on tomatoes. Operation
on tomatoes proved to be quite different from that on other fruit,
such as peaches. For example, peach skins virtually disintegrate
upon lye treatment and are easily removed, but tomato skins remain
as large pieces or in some cases stay completely intact and are thus
difficult to remove. Observations of tomato peeling during the 1972
season indicated that some accessory equipment might be helpful by
initiating rupture of the skin before the rubber disc peeling operations.
Also during the 1972 season, preliminary work was done at WRRC on
cleaning tomatoes, using the same configuration of rubber discs used
in peeling work.
The following people and organizations cooperated in the study:
Western Regional Research Center, Berkeley, CA - R. P. Graham,
M. R. Hart, J. M. Krochta, G. S. Williams, W. C. Rockwell, A. I.
Morgan, Jr.; National Canners Association, Berkeley, CA - W. W.
Rose, N. L. Yacoub, H. J. Maagdenberg, W. A. Mercer; Hunt-Wesson
Foods, Hayward, CA - E. F. Haarberg; Canners League of California,
Sacramento, CA - J. W. Bell.
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Tomatoes coming into a plant have up to 2 percent soil present as
clods, up to 0.2 percent soil as smear on the tomato surfaces, and
tomato juice from broken fruit. Cleaning of tomatoes is a multiple-
step operation. Tomatoes are initially dumped into water to avoid
further damage. The dump water also serves to eliminate the soil
clods and accumulated juices, and to wet and initiate removal of
smear soil and juices. This smear is difficult to remove. Con-
ventionally, energy for removal is provided by flumes and water
sprays which follow a dump tank. The 1972 work at WKRC showed the
potential for supplying the energy for smear soil removal with
rotating rubber discs, using a much smaller amount of water.
Subsequently, discussions held with research personnel from the
National Canners Association (NCA) resulted in the decision to set
up an integrated pilot plant at a cannery to study rubber disc
cleaning and peeling of tomatoes.
The NCA made arrangements with Hunt Wesson Co. to permit installation
of a 2 to 5 ton-per-hour plant at their "A" street cannery in Hayward,
California. This location was ideal because tomatoes used in the
cleaning and peeling studies could be returned to a flume leading to
the cannery's product line.
The WRRC built the pilot plant equipment and supplied the operating
personnel. The Berkeley laboratory of the NCA did the sampling and
analysis. Some financial assistance was provided by the Canners
League of California under arrangements made by the NCA. Tomatoes
and the utilities were furnished by Hunt Wesson Co. and their
personnel were most helpful and cooperative throughout the study.
TOMATO PILOT PLANT
Description of Plant
The plant was set up as shown in Fig. 1. Detailed descriptions of the
equipment will be presented later in a complete report. Cannery
tomatoes were received in 1000 pound tote bins. The plant began with
a platform scale where tote bins were weighed to determine the amount
of tomatoes being processed. This was followed by a bin dumper where
tomatoes were dumped into water to cushion their fall, wet them, and
remove clod soil and accumulated juices. Dumping was controlled so
that all of the tomatoes were wetted for approximately the same time
before removing them from the dump tank. This time varied from 1-2
minutes. An elevator then carried the tomatoes to a rubber disc
machine where smear soil and other contaminants were removed. Broken
and undersized tomatoes were then sorted out as they passed over a live
roller conveyor. Sorted tomatoes were elevated to a ferris wheel caustic
dipper where they were lye treated. Leaving the caustic dipper, the
tomatoes rolled over a slitter where numerous small cuts were made in
their skin. The tomatoes were then peeled by a rubber disc machine.
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116 .
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The final piece of equipment was a rinsing bath, after which the peeled
tomatoes were weighed and sent to the plant product line.
The two rubber disc machines were essentially duplicates. Both were 12
inches wide by 10 feet long and built so that the slope of the machines
and the speed of the discs could be varied. The action of the 4 1/2 inch
rotating discs in cleaning or peeling is to wipe the tomato with the sides of
the disc and throw waste material into collectors. Each machine con-
tained two 5-feet-long collectors dividing the machine into halves.
The waste from each half, containing both liquid and solids, was
collected separately for measurement. The discs in the cleaning
section were usually run at 400 rpm with the slope of the machine
set at 16 inches rise in 10 feet. The discs in the peeling section
were run at a speed of 300-400 rpm with a rise of 14 inches in 10
feet. Under these conditions the usual residence time for tomatoes
in the rubber disc cleaner was 15-25 seconds, and in the rubber disc
peeler, 20-30 seconds.
When the entire line was operated, capacity was limited to from 2 to
2.5 tons per hour by the peeling section. In separate cleaning tests,
where the peeling section was by-passed, the feed rate was as high
as 5 tons per hour. During operating runs all of the tomato components
and liquid effluents were weighed to provide material balances.
The plant was operated over the entire season to study all maturities
of tomatoes. Both VF-198 pear and VF-145 round tomato varieties were
successfully processed. The total amount run was 45 tons in 1,000-
pound batches. Complete data on the operation of the plant is being
published in a booklet through the efforts of the National Canners
Association and the Canners League of California and will be available
for distribution.
Cleaning
The cleaning unit was provided with several sets of nozzles to permit
the use of foam, detergent water, or plain water. Our tests indicated
that tomatoes wetted in the dump tank and then run on the disc machine
could be adequately cleaned with water alone. However, it is entirely
possible that tomatoes harvested under more adverse circumstances
could benefit from the use of a detergent. These tests showed that
the application of as little as 5 gallons of water per ton of tomatoes
applied just short of the discharge of the cleaner could reduce the
smear soil to 7 ppm and could reduce the bacteria and mesospore count
by about 95 per cent. In addition, the spinning discs removed 40-70 per
cent of stems still attached to the tomatoes.
The function of the dump tank must be emphasized, as in addition to
cushioning the dumping it removed most of the soil clods and juice
from broken tomatoes. A reduction in the soil clods brought into the
plant plus a possible means to drain away juice from broken tomatoes,
and the use of the disc cleaner could permit more recirculation of the
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dump water and thereby substantially reduce the amount of water used
per ton of tomatoes. (We hope to do further work next season towards
the elimination of the soil clods on the field harvesters so that they
will not be hauled into the plant.)
Lye Peeling Section
Whole canned tomatoes are a very important product. Of the approximately
five million tons of tomatoes harvested annually in California, 10 to 15
per cent are lye peeled and canned as whole tomatoes. The peeling
operation consumes very large amounts of water and generally requires a
considerable amount of hand labor for sorting.
The machine was operated to provide fairly complete peeling. Peeling
evaluation is described in the complete report and consisted of examining
samples of tomatoes for completeness of peel removal. Most runs had
over 80 per cent of the tomatoes completely peeled and over 95 per cent
at least partially peeled. Peeling loss ranged from 15 to 20 per cent
and was equivalent to present cannery operation.
In spite of the 30-second treatment of the tomatoes in 18 per cent
caustic at 220°F,the tomato skin still had considerable tensile
strength. The skin was fairly well loosened from the tomato but
was difficult to remove. One of the unique features of this lye
peeling plant was the slitter used to assist in the peeling operation.
The slitter consists of two rows of rotating 3-inch-diameter knives
spaced 1/2 inch apart. The knives protrude through an adjustable
table which was used to vary exposure of the knives from 0-0.1 inch.
The 0.1 inch exposure gave the best results. As the tomatoes rolled
down the incline from the ferris wheel lye dipper, they received
several slits about 0.1 inch deep and 0.25 inches long. Peeling was
definitely improved as compared with tests where the slitting discs
were retracted. However, for future plant work a third or fourth
row of knives might prove advantageous.
Twelve low-pressure nozzles sprayed water on the tomato bed at a rate
of about 60-80 gallons per ton. Good peeling at 2 to 2.5 tons per
hour was obtained when the bed was fully covered. If the water sprays
were reduced the capacity of the machine was substantially reduced.
The water and the skins from the peeler were run over a 1/8 inch-hole
perforated screen where the skin was separated from the alkaline puree.
The puree had a solids content of 2 to 3 per cent and when neutralized
to pH 4.5 and concentrated gave a product that was essentially free
from contamination. Microscopic examination showed the material to
consist of over 50 per cent whole tomato cells. Some canners may find
it advantageous to recover the cell material by settling and centrifuging
in order to reduce the effluent BOD.
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A number of tomatoes showing marks from the slitter were canned
in standard canning juice and pressure cooked. When the cans were
opened the slits were no longer noticeable.
SUMMARY
A conventional dump tank was used to remove most of the soil clods
and juice from broken tomatoes. Use of the rubber disc machines
substantially reduced water requirements for subsequent smear soil
removal and for caustic peeling, with no loss in product quality.
Effective smear cleaning was obtained with about 5 gallons of water
and effective peeling with about 75 gallons per ton of tomatoes.
The reduction of the volume of effluent streams should result
in more efficient treatment.
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INTEGRATED BLANCHING AND COOLING TO REDUCE PLANT EFFLUENT
by
John L. Bomben*, George E. Brown*, William C. Dietrich*,
Joyce S. Hudson* and Daniel F. Farkas*
INTRODUCTION
Blanching of vegetables for freezing, canning or dehydration produces a
large portion of the total organic solids in a plant effluent (1). In
most cases over 50% of the plant BOD is due to blanching and cooling.
Reducing this effluent would give a large reduction in the 800 million
pounds of BOD and 392 million pounds of suspended solids produced by the
canned and frozen fruits and vegetable industry.
In recent years the National Canners Association has investigated means
of reducing pollution from blanching. The characteristics of water,
steam, microwave and hot gas blanching were studied (2). It was found
that hot gas blanching gave a system which reduced blancher effluent
to a very low volume for some products (3). However, hot gas blanching
required more energy than conventional blanching, and it was applied
only to canned vegetables where there is no need for cooling. Cooling
can leach as much, or more, solids from the products as does blanching
(4),
The USDA Western Regional Research Laboratory has conducted research on
improving steam blanching so as to reduce effluent volume and BOD as
well as improve product quality by reducing over-blanching. This
research resulted in the development of a heating and holding technique
called Individual Quick Blanching (IQB) (5). With IQB the product is
heated with steam in a single layer on a conveyor to a mass average
temperature sufficient for enzyme inactivation, and the product is held
adiabatically in a deep bed on a second conveyor allowing enough time
for temperature equilibration and enzyme inactivation. This method
reduces leaching from the product and thereby reduces effluent BOD
because of the uniform heating inherent in a single layer as opposed to
the deep bed used in conventional steam blanching. Further reduction
in leaching can be accomplished by prewarming and partially drying with
hot air the feed entering the steam heater (4).
Most cooling after blanching is done in flumes or by water sprays.
Both of these cause leaching of solids from the product and generate
_
USDA, Western Regional Research Laboratory, Berkeley, California.
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large volumes of effluent. Recently, air cooling equipment has been
installed in some freezing plants (6,7). Water sprays are used with air
cooling to reduce the evaporative weight loss in the product, and the
excess water becomes effluent. At present no data are available on the
amount of water needed, effluent produced or product yield when blanched
vegetables are air cooled.
The work described in this paper was done to demonstrate a means of
achieving a blanching and cooling method that would produce less
leaching of solids from the product to the effluent stream. Vibratory
conveyors provided a ready means of achieving compact equipment and a
design of high heat efficiency. This work is an extension of that
described by Brown, et al. (8).
PILOT PLANT EQUIPMENT
A schematic diagram of the equipment used in this work is shown in
Figure 1. The equipment consists of three sections: heater, holder
and cooler.. The heater and holder have been completely described by
Brown, et al. (8), The cooler used in that earlier work was made from
a neoprene belt conveyor, while in the work described here, a vibratory
conveyor was used. Figure 2 is a photograph of the assembled blanching-
cooling equipment.
Solid surface vibrating conveyors were chosen as the heat transfer
conveying surfaces in the heater and cooler. This type of conveyor can
be more easily cleaned than the wire mesh belts used in most steam
blanchers. They also provide a very compact design because they can be
stacked close together and they do not have the return section required
in a belt conveyor. The vibratory conveyor also gives a means of
reducing heat losses since vegetable pieces can be used to form a seal at
the entrance and exit. The relatively small size of the equipment
reduces the cost of insulation.
Heater
A detailed description of the heater and holder are given by Brown et
al. (8); thus only the main features of that equipment is given here.
An electromagnetically driven variable amplitude Syntron circular
conveyor was used in the heater. The conveyor operated with a motion
that impelled the vegetable pieces upward and forward at 3600 strokes
per minute. Two conveyor trays were stacked so that product flowed
around one tray, dropped through an opening and flowed around the other
tray to the outlet. The residence time in the heater was controlled by
varying the feed point and the position of the opening between the trays
as well as the amplitude of vibration. Steam was distributed above each
tray through tubes with a series of orfices. The heater was completely
insulated. The feed was introduced through a hopper attached to
the steam plenum; thus the feed formed a seal on one end of the heater
and the holder formed one at the other end (Figure 1).
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Holder
The holder, attached to the heater plenum, was an insulated neoprene
tube 6 inches in diameter and 10 inches long (Figure 1). The product
leaving the heater passed over a screen to separate it from the heater
condensate, and from there it dropped into the holder. The level of
product in the holder was measured with a dipstick. The bulk density of
the vegetable pieces, the holder cross sectional area and the feed rate
were the data used to calibrate the dipstick setting for the residence
time in the holder.
Cooler
The cooler (Figure 1) used in these experiments was made from a spiral
vibrating elevator (Syntron, Model No. ES-22). It, like the heater, had
a frequency of 3600 cycles/second and gave the product an upward-forward
impulse which moved the product up the spiral. A photograph of this
cooler is shown in Figure 3, where the surrounding plenum, which
directed the air flow and confined the atomized heater condensate, has
been partially removed to show the spiral elevator. The 36 inch high
elevator consisted of five 4 inch wide flights of 14 5/8 inch diameter.
The length over which the product traveled on the conveyor was 17 feet.
The plenum surrounding the conveyor was supported independently so it
did not contact the vibrating conveyor. The two blowers (1/5 horsepower,
squirrel cage type), connected to the plenum, passed 750 cfm of air
over the product co-currently. Air velocity, measured with a vane
anemometer, was regulated by an orfice at the exit of each blower, and
it was kept at the maximum possible without disturbing the flow of the
product on the conveyor. Heater condensate was atomized into the air
at each blower.
EXPERIMENTAL METHODS
Most of the operating data on this equipment was obtained with green
beans (1/2 inch cross cut, mixed sieves size, Galagreen variety). Washed
and screened green beans were obtained in 400 Ib lots from Patterson
Frozen Foods, Patterson, California. They were mixed with ice, trans-
ported in insulated containers and used 24 to 96 hours later. Since
carrot dice were found to be the most difficult to convey, uniformity of
flow in the cooler was tested with carrot dice as described by Brown
et al. (8). Carrots were topped, diced without peeling and screened to
remove fines. Raw and blanched broccoli spears and cauliflower were
also tested on the cooler to observe if these could be conveyed.
An experimental run consisted of blanching and cooling approximately
50 Ib. of raw vegetable. The feed, cooled product and effluent were
weighed. Samples of cooler effluent were refrigerated for later analysis,
Samples of the feed and cooled product, taken during the run, were
frozen.
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Samples of feed, product and effluent were analyzed for total solids
by AOAC method 20.010 (9). Chemical oxygen demand (COD) of the effluent
samples was estimated using a Beckman Total Carbon Analyzer (Model
915) (10). Peroxidase and chlorophyl were measured according to the
methods described by Dietrich and Neumann (11).
RESULTS
Table 1 summarizes typical operating conditions used in these experiments.
Table 1. Typical operating conditions
Heating Holding
Time Time
(sec) (sec)
Green Beans 45 45
Carrots 25 60
Feed Rate Excess Cooling Cooler
(Ibs/hr) Steam* Time Product
(%) (sec) Temp.(°F)
190 12 45 100
145 24 60 105
*
Equals percent over theoretical steam consumption. Theoretical steam
consumption for 60°F initial temperature and a 195°F final mass average
temperature is 13.8 lb/100 Ib feed.
Table 2 gives the yield of cooled green beans obtained with the above
operating conditions as compared to conventional blanching and cooling.
It also shows the effluent solids loss, which measures the amount of
solids lost from the feed to the effluent.
Table 3 gives the amount and COD of the effluent from the cooler. These
are compared to those obtained under conventional blanching conditions.
DISCUSSION OF RESULTS
The vibratory spiral conveyor used in the cooler conveyed both the
carrots and the green beans uniformly and continuously. When the con-
veyor was tried with cut cauliflower and broccoli spears, the 4 inch
conveyor was too narrow to convey these vegetables well, but they did
move up the length of the spiral.
It was found that the spiral conveyor required a product velocity of
approximately 17 feet/min. to give a uniform steady flow of product.
This product velocity gave a residence time of only 1 min. with green beans
and carrot dice. The resulting product temperature of 100-105°F is higher
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than the 70-80°F usually achieved before freezing in a commercial process.
A conveyor twice as long would provide a 2 min. residence time, which would
give adequate cooling (8).
Table 2. Comparison of Yields and Solids Loss in Effluent for Green
Beans Between Combined Blanching and Cooling vs Conventional
Blanching and Flume Cooling
Gross Yield*
Effluent
Solids Loss**
Reference
Combined Vibratory
Blanch-Cool
Conventional Steam Blanch
Flume Cool
Conventional Water Blanch
Flume Cool
88
95
96
2.6
5.7
6.1
This work
(2)
(2)
*/-. -IT • -i j Wt. of cooled product
Gross Yield = — r~s—7"V Ł1 —
Wt. of feed to blancher
Effluent Solids Loss =
% solids in effluent X wt. of effluent
% solids in feed
X wt. of feed
Table 3. Comparison of Effluent from Green Beans for Combined Blanching
and Cooling and Conventional Blanching and Flume Cooling
Effluent COD
(lb/100 Ib feed) (lb/100 Ib feed) Reference
Combined Vibratory
Blanch-Cool
Conventional Steam Blanch
Flume Cooling
Conventional Water Blanch
Flume Cooling
7.0
500
520
0.17
0.35
0.32
This work
(2)
(2)
The lower gross yield of green beans for combined blanch-cooling as
shown in Table 2 is characteristic of air cooling (8). The condensate
sprayed on the product is only partially reabsorbed, and it does not
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completely compensate for evaporation of moisture into the air stream.
In flume cooling there is no evaporative weight loss, but the higher
yield is accompanied by twice as much solids lost from the product.
Since frozen vegetables are sold on the basis of weight, a lower yield
means less production and can be justified economically only if the
value of lost product is balanced by the cost of increased waste
disposal.
The results in Table 3 show the large difference in volume of effluent
between conventional processing and the combined blanch-cooling. Most
of this volume (96%) is due to the flume cooling. Assuming a product
temperature out of the blancher of 195°F and cooling water temperature
of 60°F, it requires 5.8 Ib of water per Ib of product to obtain an 80°F
product temperature. This amount of flume water when added to the
blancher effluent results in twice the amount of COD and 70 times the
volume of effluent from combined blanching and cooling.
If no change is made in the way frozen vegetables are marketed, then
air cooling of any kind suffers a large cost disadvantage. Table 4
gives a comparison of the approximate operating costs of three
different kinds of blanching. The basis for this cost estimate is
taken from Brown et al. (8). It must be emphasized that these costs
are aj>proximate, and they are shown merely to make a comparison. It is
obvious that the cost of lost green beans (at $0.20/lb) due to reduced
yield is overwhelming in comparison to other costs. Even though the
combined vibratory blanch-cooler can give substantial savings in steam
and effluent costs, and a product with more retained solids, these will
not balance the cost of product lost through evaporation.
Design of Large^ Scale Vibratory Blanch-Cooler
To evaluate fully the technical feasibility of the combined blanch-cooling
approach to processing frozen vegetables it is necessary to work with
larger scale equipment. Figure 4 is a schematic diagram showing the
configuration and the dimensions of a 1 ton/hr. vibratory blanch-cooler.
The heater and cooler would have adjustable feed points to accomodate
the different residence times needed for different products. The holder
would be a live bottom bin with an automatic level control, which could
be adjusted to maintain different holder residence times.
The cooler would use the same type of conveyor as in the heater, but
the central column of the spiral could be used to direct the air flow.
The cooler spiral conveyor would have to be much longer to accomodate
up to 5 min. residence time for large vegetables such as broccoli and
Brussels sprouts.
Equipment of this size is available from several manufacturers at an
estimated cost of $60,000. It would require a floor area of about 15
ft, x 15 ft.
125
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1. NATIONAL CANNERS ASSOCIATION, "Liquid Wastes from Canning and
Freezing Fruits and Vegetables," Office of Research and Monitoring,
Environmental Protection Agency, Washington, B.C. (1971).
2. RALLS, J. W., MAAGDENBERG, H. J., YACOUB, N. L., ZINNECKER, M. E.,
REIMAN, J. M., KARNATH, H. 0., HOMNICK, D. N., and MERCER, W. A.
Reduced waste generation by alternate vegetable blanching systems.
Proceedings of the 3rd National Symposium on Food Processing Wastes,
New Orleans, La., Environmnetal Protection Technology Series EPA-
R2-72-018, 25 (1972).
3. RALLS, J. W., MAAGDENBERG, H. J., YACOUB, N. L., ZINNECKER, M. E.,
REIMAN, J. M., KARNATH, H. 0., HOMNICK, D. N., and MERCER, W. A.
In-plant hot-gas blanching of vegetables. National Canners
Association Publication D-2614, (1972).
4. BOMBEN, J. L., DIETRICH, W. C., FARKAS, D. F., HUDSON, J. S.,
DE MARCHENA, E. S., and SANSHUCK, D. W. Pilot plant evaluation of
Individual Quick Blanching (IQB) for vegetables. J. Food Sci. ,
38: 590 (1973).
5. LAZAR, M. E., LUND, D. B., and DIETRICH, W. C. IQB: A new concept
in blanching. Food Tech., 25: 684 (1971).
6. COFFELT, R. J., and WINTER, F. H. Evaporative cooling of blanched
vegetables. J. Food Sci., 38: 89 (1973).
7. SMITH, W. L., and ROBE, K. Saves 300-400 gpm water, improves
vegetable quality. Food Processing, 34(3): 36 (1973).
8. BROWN, G. E., BOMBEN, J. L., DIETRICH, W. C., HUDSON, J. S., and
FARKAS, D. F. A reduced effluent blanch-cooling method using a
vibratory conveyor. J. Food Sci., (in press).
9. AOAC. Official Methods of Analysis, 10th Ed. Association of
Official Agricultural Chemists, p. 308, Washington, D.C. (1965).
10. APHA. Standard Methods for the Examination of Water and Wastewater,
13th ed., p. 257. American Public Health Association, New York
(1965).
11. DIETRICH, W. C., and NEUMANN, H. J. Blanching Brussel Sprouts.
Food Tech., 19(5): 150 (1965).
12. IELMINI, J. Private communication on cost of green beans. (1974).
Reference to a company and/or product name does not imply approval
or recommendation of this product by the U.S. Department of Agriculture
to the exclusion of others which may also be suitable.
127
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Figure 2. Photograph of Assembled Vibratory Blancher-Cooler
129
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Figure 3. Photograph of Partially Assembled Vibratory Spiral Cooler
130
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RECOVERY OF ACTIVATED SLUDGE FOR POULTRY FEED
ENGINEERING ASPECTS
Dr. Richard H. Jones* and Leonard P. Levine*
INTRODUCTION
Citrus processing plants in Florida are faced with increasingly
stringent wastewater effluent limitations. The three major waste-
water treatment processes "being used in an attempt to meet these
effluent limitations are spray irrigation, aerated lagoons and acti-
vated sludge. Activated sludge is the only alternative available for
numerous plants because adequate land is not available to install
other processes. One of the major problems with the operation of an
activated sludge process is the handling and disposal of excess sludge.
Winter Garden Citrus Coop installed an activated sludge plant to
treat their concentrated wastewater in 1968. The operation of this
system has been reported in a previous publication (l). The original
design called for dewatering of waste activated sludge in a solid
bowl centrifuge and recovery of the sludge along with citrus peel
as a cattle feed. The solid bowl centrifuge proved unsatisfactory
and waste sludge had to be disposed of by placing it directly on
the citrus peel prior to being dried in a rotary kiln dryer. Due to
the low solids content of the waste sludge (2.0-3.0 percent) the
dryers could not handle all of the excess sludge and Winter Garden
Citrus was forced to dispose of excess sludge by land spreading.
Winter Garden Citrus decided to evaluate other methods of thickening
and dewatering activated sludge and to determine the feasibility of
recovering waste activated sludge as poultry feed. This report
covers the results of both full scale gravity thickening studies,
centrifugation studies and pilot plant rotary kiln dryer studies.
Results of chicken feeding studies at the University of Florida
are reported in the following paper.
WASTE ACTIVATED SLUDGE
Figure 1 shows a schematic diagram of the Winter Garden Citrus Pro-
ducts wastewater treatment plant as it presently operates. Excess
activated sludge at the rate of approximately 0.5 to 0.6 Ibs of solids
per Ib of BOD removed is wasted to a gravity sludge thickener. Table
1 shows typical chemical analyses of the waste activated sludge.
The waste sludge concentration averaged approximately 8,000 mg/1.
The quantity of solids wasted averaged approximately six to seven
tons per day.
*Environmental Science and Engineering, Inc., Gainesville, Florida.
132
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Table 1. Analyses of Waste Sludge
Month
1
2
3
k
5
6
Flow
GPD
187,000
178,000
178,000
187,000
187,000
187,000
Total
Solids
mg/1
7,320
11,290
8.U20
7,560
6,670
8,750
Volatile
Solids
mg/1
6.UUO
10,110
8,070
6,5^0
5,600
7,800
Waste
Sludge
Ibs/day
11,1*20
16,760
12,500
11,790
10,1*50
13,650
EFFICIENCY OF SLUDGE THICKENER
The sludge thickener is a converted lime treatment tank. The
loading averaged only 80 gallons/ft /day or 5 l"bs of solids/ft2/day.
With proper operation a sludge thickness in the underflow of from
3.0 to 3-5 percent could toe obtained. Assuming an influent and
underflow total solids concentration of 0.8 and 3.0 percent, re-
spectively the sludge thickener was able to decrease the sludge
volume approximately 73 percent.
Due to the low loading rate on the thickener, periodic problems
were experienced with the settled sludge becoming septic. This
occurred every two or three weeks and was solved by simply pumping
the total contents of the thickener back into the aeration basin
and starting the thickener again with fresh sludge.
EFFICIENCY OF CENTRIFUGATION FOR SLUDGE DEWATERING
The selection of gravity thickening instead of air flotation for
sludge thickening was dictated by the presence of the lime treatment
tank which could easily be converted to a gravity sludge thickener.
The use of rotary kiln drying of all citrus peel dictated the
selection of that process for final sludge drying because of the
availability of equipment. The selection of centrifugation for
sludge dewatering was a matter of judgement. Solid bowl centri-
fugation had been proven unsatisfactory with this type sludge,
however, results with a basket type centrifuge for dewatering
domestic sludge showed encouraging results. For this reason, a
134
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decision was made to test tooth a Fletcher basket type centrifuge
as veil as a Westfalia disk type centrifuge for sludge dewatering
following gravity thickening.
Figure 2 shows the predicted capacity of the Fletcher type centri-
fuge. This information was developed through extensive on-site
testing using a Fletcher SST-900 centrifuge. Tests were conducted
at various feed rates with and without polymer addition. The
main effect of polymer addition was to increase solids recovery
and decrease cake percent solids. The improvement in solids re-
covery was not of a sufficient magnitude that would warrant polymer
addition. The solids in the cake varied from approximately 7-0 to
10.0 percent depending upon the feed rate to the centrifuge. Assuming
an average sludge solids concentration from the centrifuge of 8.0
percent the combination of gravity thickening and centrifuge de-
watering removed 90 percent of the water from the initial sludge
wasted from the activated sludge plant.
Extensive tests were conducted using a Westfalia disk type centrifuge.
Table 2 shows typical results utilizing the Westfalia Centrifuge.
Tests 1 through 31 were conducted without polymer and Test 32-37
were conducted with the addition of polymer. Results of these
tests showed that the Westfalia and the Fletcher provided approxi-
mately the same results.
Several problems were experienced with the Westfalia Machine', how-
ever, the most significant being internal wear of the machine caused
by sand in the activated sludge. No provision for sand removal
was provided in the waste treatment plant, therefore, quantities
of sand from fruit washing found its way into the system and into
the waste sludge. Because of the design of the disk type centrifuge
the sand caused wearing of metal surfaces resulting in the machine
being taken out of service for repair. Unless all abrasive materials
are prevented from entering this type of centrifuge it is questionable
if it can be utilized for sludge dewatering.
PILOT PLANT ROTARY KILN DRYER
A rotary kiln dryer pilot plant was selected for drying the activated
sludge solids because Winter Garden Citrus dries approximately 600 tons
of citrus peel each day by this method. The pilot plant dryer was a
three-pass drum type dryer constructed of two concentric rotating drums
inside a third stationary insulated drum 6.0 ft. long and 30 inches in
diameter. Heat was supplied by a propane torch and the kiln was op-
erated at an inlet temperature of 1100°-lUoO°F. The drums rotated at
a rate of 15 rpm and the kiln was hand fed from 75-125 Ibs/hr. Material
transport within the kiln was achieved by sets of parallel longitudinal
baffels attached inside all three drums. After the third pass in the
dryer, the material was pulled into a two-stage cyclone and collected
in a container. Material fed into the kiln was maintained at 30-^0 per-
cent moisture by mixing recycled product with dewatered sludge.
135
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i
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SST - 1600
FEED = 1.5%
10 15
20
25
30
35
40
45
FEED= 2.5%
40"x 30"
SST - 900
50 55
10 12 14 16 18 20 22 24 26 28 30 32
(NET) FEED RATE , GPM
FIGURE-2 FLETCHER CAPACITIES ON
WINTER GARDEN ACTIVATED
SLUDGE 136
-------
TABLE 2 TYPICAL RESULTS
WESTFALIA CENTRIFUGE
Test
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Feed Rate
GPD
9.0
9.0
9.0
9.0
5.5
5.5
5.5
5.5
15.0
15.0
9.0
9.0
9.0
-
5.0
5.0
5.0
5.0
6.0
6.0
Sol
Feed
Percent
1.2
1.2
1.2
1.2
0.9
0.9
1.4
1.4
1.4
1.4
2.2
2.2
2.2
**•
2.2
2.2
2.4
2.4
2.4
2.4
ids
Cake
Percent
7.6
7.7
5.5
8.2
8.1
5.9
9.7
8.4
6.4
6.8
8.2
6.9
7.6
-
9.2
7.4
8.7
8.3
8.1
9.0
Effluent
Percent
0.14
0.12
0.12
0.23
0.12
0.12
0.29
0.11
0.14
0.18
0.72
0.19
0.37
-
0.14
0.07
0.08
0.11
0.61
0.52
Percent
Recovery
89
90
90
81
86
86
80
92
90
87
67
92
83
-
94
97
97
96
75
79
137
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TABLE 2 TYPICAL RESULTS
WESTFALIA CENTRIFUGE
(Continued)
Test
No.
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
Feed Rate
GPD
9.0
8.0
4.5
8.0
7.0
4.5
8.0
8.0
8.0
7.0
7.5
7.0
7.0
7.0
8.0
8.0
7.5
Sol
Feed
Percent
2.3
2.1
2.1
1.9
1.9
2.2
2.2
2.2
2.6
2.1
2.2
2.2
1.5
2.4
2.4
2.2
2.2
Ids
Cake
Percent
6.8
7.2
6.9
6.3
6.4
5.5
7.0
7.2
6.0
5.7
6.4
6.3
5.7
6.6
6.2
6.7
7.1
Effluent
Percent
0.13
0.48
0.29
0.25
0.24
0.15
0.27
0.78
1.0
0.40
0.12
0.10
0.08
0.13
0.14
0.12
0.11
Percent
Recovery
94
77
86
87
88
93
88
65
62
82
95
96
95
94
94
95
95
NOTE: Test numbers 1-33 with "open foot," 34-37 with "closed foot."
Test numbers 32-35 with 5.0 Ibs Hercofloc/ton dry solids
Test numbers 33-36 with 10.0 Ibs Hercofloc/ton dry solids
138
-------
Table 3 shows the results of 20 separate pilot plant "runs." Each
run represents a successful operating day when the pilot plant was
kept in continuous operation from 10 to 12 hours. There were num-
erous days that either weather conditions or mechanical failure
caused the pilot plant operation to be terminated.
The pilot plant not only provided engineering and cost data for the
design and operation of a full scale unit but was also utilized to
supply dried sludge for the chicken feeding studies. Several hundred
pounds of sludge were produced in this manner, however, a sand drying
bed finally had to be used to supply the large quantity of sludge re-
quired for the feeding studies.
COST OF RECOVERING WASTE SLUDGE FOR CHICKEN FEED
The following assumptions were made in conducting the preliminary
cost estimate:
1. The sludge handling facilities would consist of:
A. Sludge thickener
B. Thickened sludge holding tank
C. Fletcher centrifuges
D. Rotary kiln dryer
E. Miscellaneous pumps, pipes, conveyors, etc.
2. Maximum waste sludge volume of 0.2 mgd % 0.8 percent solids.
3- Thickener underflow of 2.5 percent solids.
h. Centrifuge cake of 7-7 percent solids.
5- Fuel cost $0.80/ 1x10^ Btu.
6. Dryer efficiency = 56 percent.
7- Dryer yield = 75 percent of input solids.
8. Operating days = 150.
9. 20 year straight line depreciation.
10. 10 percent interest on borrowed money.
YEARLY
EQUIPMENT CAPITAL COST OPERATION & MAINTENANCE
Sludge thickener
Holding tank
Centrifuges
Kiln Dryer
Pipes, pumps, etc.
Total
$150,000
35,000
160,000
55,000
50,000
$1+50,000
$ 5,000
1,000
16,000
3,000*
5,000
$30,000
*Excludes fuel cost
139
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TABLE 3 PILOT PLANT KILN DATA
Run
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Temp.0
Inlet
1200-1400
1200-1400
1200-1400
1200-1400
1100-1300
1100-1300
1100-1300
1100-1300
1100-1300
1200-1300
1200-1300
1200-1300
1200-1300
1100-1200
1100-1200
1100-1200
1100-1200
1150-1200
1000-1250
1100-1200
Total Solids
F of Percent
Outlet Influent Cake
150-175
150-175
165-185
175-200
175-200
175-200
175-200
175-200
175-200
175-200
175-200
175-200
175-200
175-200
175-200
175-200
175-200
175-200
175-200
175-200
3.5
4.2
2.6
2.3
3.3
3.2
3.2
4.9
3.7
3.8
3.6
2.4
2.6
4.8
3.9
4.8
4.6
6.5
4.6
5.8
74
89
90
94
94
91
92
92
93
93
95
98
98
96
94
92
95
95
96
94
Total
Volatile Solids
Percent
Influent Cake
—
89
90
90
90
86
92
93
91
84
96
86
93
92
87
90
88
91
87
90
—
74
74
75
66
72
70
69
69
69
73
75
70
71
69
70
76
79
76
77
Pounds
Cake
Produced
14
7
10
4
5
8
6
5
4
4
4
2
3
4
4
4
4
2
7
5
140
-------
The capital investment cost each year will be $U5,000. The yearly
operating cost will be $30,000 and the fuel cost will be $35,000.
Therefore the estimated yearly cost will be $110,000 and with a
waste sludge of 900 tons per season the cost will be approximately
$122/ton.
There are several reasons for the high cost of drying sludge. Due
to the high moisture content of the dewatered sludge it will cost
$50/ton for fuel alone. If the sludge could be dewatered to 20 per-
cent solids before entering the kiln dryer it would cost only $19-25/
ton for fuel. Another reason for the relatively high drying cost is
that the citrus plant operates only a portion of the year yet the
capital cost must be paid for throughout the year. The capital cost
when operating 150 days per year are $50/ton. If the processing
plant operated 300 days per year, the capital cost would only be $25/
ton.
The final cost for disposing of sludge by drying and selling for
chicken feed will depend upon the value of the sludge when sold. The
feasibility and value of sludge as chicken feed will be discussed in
detail in a following paper.
1. U.S. Dept. of Interior, EPA, 1971. Complete MIX activated
sludge treatment of citrus process wastes.
141
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EVALUATION OF ACTIVATED CITRUS SLUDGE AS A POULTRY FEED INGREDIENT**
B. L. Damron*, A. R. Eldred*, S, A. Angalet*, J, L. Fry* and R. H. Harms*
INTRODUCTION
Activated sludge has been the subject of animal feeding trials for well
over 20 years. The material is a concentrated source of nitrogen for
the ruminant animal and, even though the biological value of its proteins
has been determined to be in the neighborhood of 50%, research with
ruminants has indicated that the nitrogen retention from activated sludge
is equal to that from soybean oil meal or urea (1). Activated sludge has
also been found to be a very good source of vitamin B,2, and feeding
trials employing synthetic diets have indicated that a level of 2% sludge
provides a satisfactory level of B,2 for the pig. Similar studies with
chicks yielded the information that as little as 1% sludge furnished an
adequate amount of vitamin B,2 for growth. Levels up to 3% gave an
additional response which coufd not be attributed to the presence of
vitamin B,2 alone and was felt to indicate the presence of unknown
growth factors; possibly due to the fermentation process involved. Taste
panel members detected no differences between the meat of sludge-fed
birds and that of birds receiving control diets (1).
A very recent study published by the Bureau of Sport Fisheries and Wildlife
(2) concerning the use of dried sludge from paper processing waste in the
diets of rainbow trout indicated that dried sludge has potential as a
protein ingredient for trout feeds. With the exception of one abstract
published in 1955 (3), the journal of the Poultry Science Association
contains a paucity of information concerning the evaluation of sludge in
practical-type poultry feeds.
This research was not designed to assay nutrients or determine biological
availability, but rather to gain basic information about what practical
levels of the material could be utilized, level of toxicity, and taste
impartation to meat or eggs.
PROCEDURE
Before feeding trials were started, the basic nutrient composition of the
material in terms of the common elements that would be found in a poultry
diet was examined (Table 1).
_
Department of Poultry Science, University of Florida, Gainesville, Florida
**32611.
This investigation was supported by funds from the Environmental Protection
Agency, Pacific N.W. Regional Laboratory, under Grant No. S-801432,
142
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Table 1. Sludge Composition
Moisture 6,30
Protein 38,6
Crude Fiber 12,6
Calcium 1,49
Phosphorus 1,59
Methionine 0,50
Cystine 0,20
Lysine 1.30
Metabolizable Cal./Kg. 1760
In vitro evaluations indicated that sludge contained quite a bit of
protein and phosphorus which are expensive ingredients for poultry feeds,
and was a good source of lysine and the sulfur containing amino acids -
methionine and cystine. These are the amino acids which are normally in
shortest supply in poultry feeds where corn and soybean meal are the
staple ingredients. The relatively high level of fiber was also of
concern since chickens do not have the enzymes necessary to digest fiber,
The metabolizable energy value is approximately one-half that found in
yellow corn. Much of the work reviewed dealt with the sludge as a source
of vitamin B,,>. Although sludge products did meet this need very well,
that approach was not pursued in this research because most poultrymen
utilize a vitamin and trace mineral package in all of their feeds,
therefore, additional B19 activity would not be of major importance to
them. '*
The studies being reported were divided into three experimental phases -
two short-term chick trials, an eight-week broiler study, and a six-month
feeding period with laying hens including pilot work with egg color and
taste evaluation.
Chick Studies
The initial two experiments were conducted in electrically heated battery
brooders with raised wire floors to prevent fecal recycling, This battery
unit contained 24 separate pens, with ten chicks housed in each pen, In
each of the two experiments four replicate pens, each containing five
male and five female day-old broiler-type chicks, received dietary treatments
consisting of various levels of citrus sludge for a three-week feeding
period.
In the first experiment the birds received diets containing 0, 2,5, 5, 10,
15 or 20% citrus sludge. The diets were composed primarily of yellow corn
and soybean meal in combination with other ingredients commonly employed
in poultry feeding (Table 2).
143
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Table 2, Diet Composition (Exp. 1 and 2)
20% "20% +'
Yellow Corn 54.97
SBOM (48.5%) 36.50
Alfalfa Meal (17%) 2,50
Citrus Sludge 0
Ground Limestone (38%) 0.74
Defluorinated Phosphate 2,11
(18% P; 32% Ca)
Salt 0.40
Microingredients 0.50
Animal Fat 2.15
D-L Methionine 0.13
Lysine 0
45,94
21.98
2,50
20,0
1.05
0,92
0,40
0.50
6.47
0.25
0
0,38
0.26
In the interest of space only the basal and the diet containing the
highest level of sludge are shown. All of the diets in the series were
calculated to contain 23% protein, 1,1% calcium, 0,755% total phosphorus,
0.88% total sulfur ami no acids and 3,012 kilocalories of metabolizable
energy per kilogram. The inclusion of citrus sludge allowed for
corresponding decreases in the amounts of yellow corn, soybean meal and
defluorinated phosphate necessary to maintain equivalent diets, however,
large increases in the amounts of animal fat and DL-methionine were
required in order to maintain energy and sulfur amino acid levels,
Since previous work has indicated that sludge is very prone towards the
destruction of unstabilized vitamin D sources, a supplemental level of
2,200 International Chick Units of vitamin D., per kilogram of diet was
employed. This level of fortification was approximately 10 times greater
than the requirement level of the starting chick as defined by the
National Research Council (4).
Statements of probability are based on the analysis of variance as
described by Snedecor (5), with significant differences among treatment
means being determined by the multiple range test of Duncan (6),
There were no significant treatment differences among the daily feed
consumption values shown in Table 3,
144
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Table 3, Chick Performance Data (Exp, 1)
Treatment
(% sludge)
0
2.5
5,0
10,0
15,0
20.0
Feed/Bird/Day
(gm.)
30.4
29.6
29.6
30,5
31,0
31,6
Feed/Body Wt!
(gm.)
1,48a
1,45a
1,45a
-.U
l,51ab
1.59b
1.74C
Means without common letters are significantly
different according to Duncan's multiple range
test (P <.05)
In terms of feed efficiency, as measured by grams of feed consumed per
gram of body weight, up to 10% citrus sludge did not significantly affect
this parameter. The feed efficiency value for birds fed a diet containing
15% sludge was not significantly different from the value for the 10%
sludge diet, but was different from values obtained for all other diets.
Birds receiving a diet containing 20% sludge had a feed efficiency
significantly higher than all other treatments. It should be pointed out
here that in any discussion of feed efficiency, the least amount of feed
required for a unit of gain or body weight, or per dozen eggs, represents
the best efficiency of feed utilization. In this instance, birds
receiving diets containing 2.5 or 5% citrus sludge had the best feed
efficiency values.
Inclusion of up to 10% citrus sludge in the diet did not significantly
affect final body weights at the end of a three-week experimental period
(Table 4).
Table 4, Chick Body Weights (Exp, 1)
Treatment Body Wt,
(% sludge) (gm.)
-^b
2.5 413a
5,0 409abc
10.0 403abcd
15.0 390cd
20.0 365e
Means without common letters are significantly
different (P <,05) according to Duncan's Multiple
range test.
145
-------
Weights of birds receiving the 15% citrus sludge diet were not significantly
different from those of either the 5 or 10% sludge treatments; however, birds
receiving 20% sludge were significantly lighter than any other treatment
group.
From the data obtained in the first experiment it was evident that some
change in treatments should be made before the next study was initiated.
It was felt that the growth depression associated with the 20% sludge
diet might have been due to the low availability of sulfur amino acids,
or because the dietary lysine level was slightly below the National
Research Council's suggested requirement. Therefore, in the second
experiment the amounts of methionine and lysine supplied in the first
experiment by the inclusion of 20% citrus sludge were added back to this
diet in purified form, resulting in total supplemental levels of 0.38%
methionine and 0.26% lysine. Thus, the dietary treatments of the second
experiment consisted of 0, 2.5, 5, 10 or 20% sludge, with a sixth
treatment of 20% sludge plus additional methionine and lysine. The latter
diet will subsequently be referred to as the "20% plus" diet (Table 2),
As in the first experiment, all but the "20% plus" diet were calculated
to be isonitrogenous, isocaloric and meet all other requirements of the
starting chick.
Table 5.Chick Performance Data (Exp, 2)
Treatment
(% Sludge)
0
2.5
5.0
10.0
20.0
Feed/Bird/Day
(gm.)
35.8
35.6
37.3
34.4
37.2
Feed/Body Wt]
(gm.)
1.64abc
1.62a
1.66abc
1.75cd
1.83d
20.0 + Lysine & 35.3 1.74bcd
Methionine
T —
Means without common letters are significantly
different (P <.05) according to Duncan's multiple
range test.
A data summary (Table 5) similar to that prepared in Experiment 1
indicated no significant differences among daily feed intake values for
birds receiving any of the dietary treatments. There were no significant
differences among the feed efficiency values of groups receiving either
0, 2.5, 5.0 or 10% sludge. Also, efficiency values for birds receiving
diets containing 10, 20 or the "20% plus" diets did not differ significantly.
From a numerical standpoint, it appeared that levels in excess of 5%
sludge adversely affected feed efficiency.
146
-------
Table 6. Chick Body Weights (Exp, 2)
Treatment Body Wt,
(% Sludge) (gin.)
0 455ab
2,5 460ab
5.0 472a
10,0 414C
20,0 423C
20.0 + Lysine & Methionine 425C
Means without common letters are significantly
different (P <.05) according to Duncan's
multiple range test.
Table 6 presents average body weights at the end of the three-week
experimental period. There were no significant differences among the
body weights of birds receiving either 0, 2.5 or 5% sludge, however,
there was some trend towards parallel sludge and body weight increases.
Weights of treatment groups receiving above 5% sludge were all
significantly below those of the lower sludge levels previously mentioned,
but did not differ statistically from each other.
Mortality was not a factor in either experiment, as mortality records
indicated that only one bird died in each trial. Throughout all
experiments the addition of citrus sludge had no effect upon feed or
dropping condition, other than to impart a dark color to both.
These data indicate that levels of between 5 and 10% sludge could be
included in the diet of starting broiler chicks without adversely affecting
growth or other performance criteria. The exact level tolerated would be
dependant upon feed intake, as evidenced by the fact that birds of the
second experiment tolerated a lower dietary percentage because their
feed intake was higher than that of the birds utilized in the first
experiment.
Broiler Trial
The next phase was a broiler study of eight-weeks duration, which is the
standard growing period for commercial broilers. Three replicate floor
pens, each containing 10 male and 10 female day-old broiler chicks, received
each dietary treatment for the 56-day feeding period. Treatments consisted
of a control diet supplemented with either 2.5, 5.0 or 10% citrus sludge.
The diets used were identical in composition to those shown for previous
experiments, with the exception of the inclusion of a small amount of
coccidiostat at the expense of yellow corn.
No significant differences were found among 8-week body weight means
(Table 7); however, as seen in the chick trials, body weights tended to
increase through the 5% level of supplementation with the weights of the
birds receiving 10% sludge being somewhat lower than those of controls.
147
-------
Table 7, Citrus Sludge Broiler Data (8 wks.)
% Sludge
0
2.5
5,0
10,0
Body Wt,
(gms.)
1750
1772
1800
1732
Feed/Bird/Day1
(gms.)
66ab
63a
67b
68b
Feed/Body Wt
(gms.)
2.16
2.08
2.16
2.25
Means without common letters are significantly different
(P <.Q5) according to Duncan's multiple range test,
Daily feed intake values were rather variable within this experiment,
but increased levels of intake did appear to be correlated with dietary
sludge content. Again, feed required per unit of body weight was not
significantly influenced by treatment and, in general, these values
reflected the trends of body weight and daily feed intake. These data
tend to substantiate other trials in that a level of sludge somewhere
between 5 and 10% appeared to support best performance. Taste panel
evaluations of muscle tissue from these birds are currently incomplete;
however, preliminary results indicate no effect from citrus sludge
supplementation.
Laying Hen Trial
The last phase has involved the feeding of 0, 2.5, 5.0, 7,5 or 20% citrus
sludge to laying hens over a six-month period. The composition of the
basal diet and the diet containing the 20% sludge addition is shown in
Table 8.
Table 8. Laying Hen-Citrus Sludge Diet
Composition
Percent
Yellow Corn
Soybean Meal
(48.5%)
Alfalfa Meal (20%)
Citrus Sludge
Limestone (38% Ca)
Defluorinated PO.
(18% P, 32% Ca.7
Iodized Salt
Microingredients
Animal Fat
D-L-Methionine
Filler
Basal
66.50
17.96
2.50
6.77
1.94
0,40
0.50
1.10
0.06
2.27
20% Sludge
58,00
3,34
2,50
20.00
6.98
0.80
0,40
0,50
5,22
0.17
2,09
148
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These sludge additions were made while maintaining a constant level of
protein at 15%, calcium at 3,25%, ,65% phosphorus, ,59% sulfur containing
amino acids and 2,860 kilocalories of metabolizable energy per kilogram
of diet. As noted before, sludge additions allowed for the removal of
yellow corn, almost all of the soybean meal, and a large portion of the
defluorinated phosphate, with corresponding increases of animal fat and
DL-methionine, Evaluation criteria included egg production, daily feed
intake, feed required to produce a dozen eggs, mortality and egg
measurements of average weight, specific gravity and Haugh units. In
addition, organoleptic evaluations were conducted on the eggs produced
and the differences in yolk color evaluated. Eight replicate groups of
White Leghorn hens held in individual laying cages were assigned to each
dietary treatment through 7.5% sludge. Four replicate groups received
the 20% level. Statistical procedures employed in the summarization of
production data were identical to those discussed earlier.
Egg production was not affected by the addition of levels of sludge
through 7.5% (Table 9); however, the 20% level did cause a significant
depression of egg production.
Table 9. Average Laying Hen Performance
(6 months)
Treatment
(% Sludge)
0
2.5
5.0
7.5
20,0
Av. Egg Prod]
(*)
69,61a
68.32a
67.013
69,21a
42.12b
Egg Wt,1
(gms.)
62. 9a
63, 4a
63. 6a
63, 3a
59, Ob
Means without common letters are significantly
different (P <,05) according to Duncan's multiple
range test.
The average weight of eggs produced followed exactly the same trends as
egg production.
There was no significant effect upon daily feed intake until the 20%
level of sludge was reached (Table 10).
Table 10, Average Laying Hen Performance
(6 months)
Treatment
(% Sludge)
0
2.5
5.0
7.5
20.0
TM
Feed/Bird/Day1
(gins.)
113a
109a
114a
112a
92b
Feed/Doz. Eggs
(kgs.)
2.00a
l,98a
2.13a
2.013
2,86b
• * .C "
(P <,05) according to Duncan's multiple range test. 149
-------
This feed intake trend is very definitely related to egg production rate
however, it is very difficult to differentiate which is the cause and
which is the effect
-------
Table 12. Interrelationship of Dietary Citrus
Sludge and Heiman-Carver Color Rotor
Numbers.
Citrus Sludge Heiman-Carver Color
(%} Rotor Numbers
0.0 12
2.5 14
5.0 15
7.5 16
20.0 18
This score increase represents a definite increase of yolk color intensity,
with a higher number indicating the darker color.
Subsequent yolk color measurements were made with a reflectance colorimeter,
the IDL COLOR-EYE. The COLOR-EYE values represent a mathematical description
of egg yolk color with all possible biases and human judgment being removed.
For this evaluation, eggs were collected from hens in four replications
of each dietary treatment. Four eggs from each replication were then broken
out to obtain a pooled yolk sample and prepared for COLOR-EYE evaluation.
The yolk was washed under running tap water in order to remove the majority
of the albumen. Then the yolk was rolled on a dampened paper towel to
remove the remaining adhering albumen. It was then held over a beaker,
the membrane surrounding the yolk was broken with a spatula, and the
yolk contents collected. The yolk material was then hand-stirred with a
wooden tongue-depressor with care being taken to keep the incorporation
of air bubbles to a minimum. The Lucite sample holders of the COLOR-EYE
were filled to capacity, sealed and placed on their side to allow the
escape of any air bubbles from the yolk and the area where the determinations
are made. The sample and holder was then placed into the viewing part of
the machine and the values recorded as measured against a white standard.
The results of these COLOR-EYE determinations are summarized very briefly
in Table 13.
Table 13, Color Characteristics of Egg Yolk
Citrus Sludge
(X)
0.0
2.5
5.0
7,5
20.0
Dominant Wavelength
(nm.)
578.5
579,3
579,5
580.8
583,5
151
-------
As the level of dietary citrus sludge increased, the dominant wavelength,
which is the color or hue of the egg yolk, also increased, This numerical
improvement represents a change in color from yellow to a yellowish-orange
hue. Increasing sludge levels dictated the removal of both yellow corn
and soybean meal. Yellow corn is normally a prime source of egg yolk
coloration. The removal of 12.8% yellow corn from the basal diet in
order to formulate the 20% level of citrus sludge resulted in a lower
contribution of yellow corn to dietary pigmentation; however, the
addition of citrus sludge more than compensated for this reduction.
Flavor and color comparisons were also made by untrained taste panelists
from the Department of Poultry Science, University of Florida, on eggs
collected from hens receiving either the control or the 20% sludge diet.
The eggs were held for five days to permit optimum peel ability and then
hard-cooked for sampling. A paired-comparison test was used with each
panelist sampling three pairs each day, but only one pair at a time.
They were asked to select separately the egg which had the darker
colored yolk, the greater degree of albumen off-flavor and the greater
degree of yolk off-flavor. The evaluation of 86 separate pairs (Table 14)
showed that a level of 20% citrus sludge resulted in significantly darker
yolks than the control.
Table 14. Taste Panel Evaluation of Eggs From
Control and 20.0% Citrus Sludge Diets.
Preference Significant
Attribute Control Citrus Sludge Difference
Yolk Color 5
Yolk Flavor 42
Albumen Flavor 40
81
44
46
yes
no
no
Acceptance range (52.3 - 33.8) at P <.05
Eighty-one of the 86 found the citrus sludge eggs to have a darker yolk
color, which is well outside of the acceptable range of 33 to 52. No
significant off-flavor was detected for either the albumen or the yolk,
as these two parameters fall within the acceptable range.
SUMMARY
In summary, the thrust of these studies was not to assay the availability
of nutrients within this product, but rather to determine the levels
generally acceptable in diets for various classes of poultry. These data
indicate that citrus sludge levels in the range of 5 to 7.5% were
acceptable in poultry feeds, with proper attention to dietary requirements
and formulation procedures. It would appear that the energy value of
1,700 kilocalories of metabolizable energy which was assumed for this
152
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product at the outset is approximately correct, There also appeared to
be sotne depressing factor present which adversely'affects performance
at high levels. Studies with young chicks indicate that this factor is
not related to a deficiency or poor availability of the amino acids -
methionine or lysine. Although earlier work (1) has indicated that
high levels of iron present in sludge cause very rapid destruction of
unstabilized vitamin D sources, the authors are not convinced that this
was the problem since stabilized vitamin D in the amount of approximately
10 times the requirement level was added to all diets.
Evaluation of yolk color differences resulting from high level sludge
feeding by both machine and panelists indicated that yolk color was
significantly influenced by sludge feeding. No adverse flavors were
detected in either the yolk or albumen of eggs produced through the use
of citrus sludge diets.
Although a rough estimate of the value of this material as a protein
source could be made based on availability values established by other
researchers, a great deal of additional work would be necessary in order
to totally evaluate the nutritional worth of this material. The origin
of the performance depressing factor which has been present in all
studies would also need to be elucidated and, if possible, correction
procedures developed. Based on the pilot work which we have conducted
in the area of yolk color improvement, it would appear that this material
has definite promise as a source of pigment for broiler skin and egg yolks,
153
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1. HURWITZ, E. The use of activated sludge as an adjuvant to animal feeds.
Purdue Industrial Waste Conference (1957).
2. ORME, L, E. AND LEMM, C. A. Use of dried sludge from paper processing
wastes in trout diets. Feedstuffs 45(51): 28 (1973).
3. SCOTT, H. M. AND ADAMS, E.G. The effect of feeding graded levels of
activated sludge and vitamin D on growth and bone ash of chicks.
Poultry Sci. 34:1233 (1955).
4. NATIONAL RESEARCH COUNCIL. Nutrient requirements of domestic animals.
Nutrient requirements of poultry, 6th revised edition. Washington,
D.C. (1971).
5. SNEDECOR, G. W. Statistical Methods, 5th edition. Iowa State
University Press, Ames, Iowa (1956).
6. DUNCAN, D. B. Multiple range and multiple F tests. Biometrics 11:1-42
(1955).
154
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INVESTIGATION OF RUM DISTILLERY SLOPS TREATMENT
BY ANAEROBIC CONTACT PROCESS
by
T. G. Shea*, E. Ramos**, J. Rodriguez** and G. H. Dorion**
INTRODUCTION
The production of rum is accomplished by age-old processes that, in their
modern application, are similar in function throughout the industry. The
basic sequence of steps in rum production consists of: the mixing of molas-
ses, water, nutrients, and antifoamant; acidification of the above mixture;
propagation of the biomass used in the fermentation; the fermentation itself;
and the distillation of the ferment.
The slops stream, i.e., the underflow produced in the distillation of the
fermented molasses mixture, has the following typical characteristics:
COD - 70 to 100 gm/1
BOD - 20 to 60 gm/1
Total suspended solids - 7 to 10 gm/1
Total dissolved solids - 25 to 75 gm/1
Total nitrogen - 1.8 to 2.5 gm/1
Total phosphorus - 80 to 100 mg/1
Sulfate - 2 to 10 gm/1
pH - 4.0 to 4.7
The principal factors associated with the magnitude and variation of these
characteristics are: the variable quality of sugar and ash contents of the
molasses, which itself is a byproduct of sugar production; and the amount
of acidification (with I^SO^) of the molasses-water mixture to obtain an
optimal pH level for the fermentation. The slops is rich in nutrient materials
having value as cattle feed extenders and soil supplements. From a biological
treatment perspective, the slops stream typically contains a sufficiency of
nitrogen and a deficiency of phosphorus, and most of the volatile suspended
solids component of the slops stream is derived from the yeast crop produced
in the fermentation. The slops stream typically contributes two thirds of
the wastewater flows, and over 95 percent of the organic emissions, in the
wastewater streams emanating from rum distillery operations, and constitutes
the major wastewater management problem in this industry.
The general objective of the research effort described herein was to examine
at the bench and pilot scales the efficacy of rum distillery slops treatment
by the anaerobic contact process. The specific objectives of this paper are
to present the kinetic characterization (Monod kinetics) describing the
anaerobic biological treatment of slops in the anaerobic contact process,
*W. E. Gates and Associates, Inc., Fairfax, Virginia
**Bacardi Corporation, San Juan, Puerto Rico
155
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the design and operational criteria developed with the kinetic characteriza-
tion and with an evaluation of clarification capacity requirements, as
related to full scale treatment, and an economic analysis of the application.
The anaerobic fermentation process has been examined by a number of researchers
(1, 2, 3, 4, 5, 6) as the initial processing step for slops treatment for a
number of reasons, the foremost of which being:
The organic content of the slops (60 to 100 gm/1 COD) is well in excess
of the point where the oxygen demand in an aerobic system exceeds
economically attainable rates of oxygen transfer
The anaerobic fermentation process is characterized by low kinetic
reaction constants and biomass yields, the intramolecular breakdown of
complex organic compounds, and the production of methane gas as an
energy-containing byproduct
Sludges produced in a properly functioning fermenter are generally more
easily dewatered than are aerobic sludges, and a lesser mass of waste
solids is produced per unit volume of wastewater treated in the anaerobic
process than in the aerobic process
Based on prior experience with the anaerobic digestion of spent molasses
wastes, as documented in the literature, the state of the art of this appli-
cation appears to be that:
The efficacy of anaerobic digestion of this type of waste is established
High feed stream sulfate concentrations and high mixed liquor volatile a-
cid concentrations are the commonly identified toxic/inhibitory factors
in the applications
The high sulfate concentrations, being associated with sulfide generation,
have been dealt with in several cases by reduction of the strength of
the waste stream to levels where its effect was deemed marginal, and
The high volatile acids concentrations anticipated in the digestion
process have been dealt with either similarly to the preceding (by
dilution of the raw waste) or alternatively by control of the rates of
loading of undiluted wastes at a level, wherein the rate of alkalinity
production in the digestion was sufficient to maintain a suitable pH
level for the methanogenic organisms independent of the rate of volatile
acid generation
Unfortunately, due to the inconsistent frameworks used in reporting information
derived in prior investigations, it is not possible to develop from the
available information a characterization of the anaerobic digestions achieved
in prior studies and/or of the operational controls applied to achieve
successful digestions, on a rational kinetics basis, or even on a solids
balance basis. Without such information, it is impossible to interpret the
significance of empirical measures such as volumetric organic loading rate
or hydraulic residence time in terms of the viable biomass inventory associated
with the observed performance; nor is it possible, in the absence of information
on such parameters as mixed liquor solids concentrations to ascertain, or even
156
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imply, the nature of the solids handling problems to be dealt with in the
design and operation of a full scale application.
Given the absence of a transferable information base for the design and
application of a full scale rum distillery slops treatment by a process train
incorporating anaerobic fermentation, the overriding priority of the study
described herein was directed to the development of a rational kinetic basis
for unifying the understanding of the performance characteristics of anaerobic
fermentation systems in the application. Given the importance of solids
recycle in biological treatment systems, attention was directed to the anaerobic
contact process.
ANAEROBIC CONTACT PROCESS
The anaerobic contact process (Figure 1) basically consists of two unit
processes, an anaerobic fermenter and a solids separator (either gravity or
mechanical), with provisions for recycle of concentrated biomass from the
separator to the fermenter and complete mixing of the fermenter. Heating of
the fermenter contents is provided in those cases where higher throughput rates
(resulting in hydraulic residence times of hours rather than days) do not
preclude its economic feasibility, or when sufficient methane is produced in
the fermentation to satisfy heating requirements.
Fundamentally, the anaerobic contact process as originally described and
documented (7, 8) differs from anaerobic sludge digestion in that biomass
recycle and relatively low substrate concentrations are used. The literature
contains reports on the use of the anaerobic contact process for the treatment
of cannery, packinghouse, brewery, distillery fatty-acid, wood fiber, and
synthetic-milk wastewaters.
In evaluation of the literature, it was found that an anaerobic process
could be considered to be of the contact type if it met the following criteria
(8): (a) an influent concentration of 4,000 mg/1 BOD or less; (b) use of
sludge recycle; and, (c) a liquid detention time of four days or less based
on influent flow. Thus, the application of the anaerobic contact process
for the treatment of rum distillery slops, in the present study, has
represented an initial effort toward establishing the feasibility of the
anaerobic contact process for treatment of high-strength wastes containing
BOD concentrations in excess of 4,000 mg/1.
PROCESS KINETIC MODEL
The Monod model, as adapted by Gates et al (8) to the anaerobic contact
process, was selected for use in the present study because of its ability
to describe the performance (i.e., effluent substrate concentration) produced
in the anaerobic contact process as a function of the hydraulic residence
time in the fermenter, biomass recycle, and kinetic constants specific to
the biodegradation of a given wastewater.
Basic Relationships
In the development of the growth kinetic model based on the work of Monod
(9), it is assumed that gross bacterial growth is always exponential in
character, that is:
157
-------
s~
o ->->
at
Q.<4-
>
en
n)
OS
H
0)
fl>
O
I4.J
O
td
O
CO
cu
V-i
-------
de
where:
X° = organism concentration,
9 = time, and
k = specific growth rate
The expression for net growth then becomes:
dx° =kx° (i)
dX°
= (k - KD)X° (2)
ae
where K is specific autodestruction rate.
The relationship determined by Monod (9) for the growth rate constant is:
kmXN
k -- N~
K +X
where :
km = max specific growth rate,
X = concentration of controlling substrate, and
K = substrate concentration when k = k /2
Combining Equations 2 and 3 gives the overall expression for the change in
organism concentration with time, that is:
de
FkmXN
K+X'
•N
X° (4)
For wastewater treatment processes, however, the major interest is in the
change of substrate concentration with time rather than a terminal interest
in the growth characteristics and capabilities of the bacteria. The relation-
ship between organism concentration change with time and substrate concen-
tration change with time can be expressed as follows:
dX° _ dxŁ
de ~ Y de
where Y° is mass of organisms produced per mass of substrate decrease.
Combining Equations 1, 3, and 5 yields:
x°
de
which is the working relationship describing the rate of substrate consumption
when the Equation of Monod (9) is used.
159
-------
When Equations 1, 2, 3, and 6 are applied to a continuous-flow, completely
mixed reactor at steady state with recycle, the type employed in the bench
and pilot-scale experiments, the following equations can be derived from
nutrient and solids balances around the anaerobic contact system to describe
the characteristics of such a reactor:
Xi° = Y (X° " Xl ) (7)
x . , K(K°6t + c°>
1
k = KD + C°/9t (9)
where :
X"L° = effluent organism concentration,
Xo = influent substrate concentration,
X^N = effluent substrate concentration,
KD = specific autodestruction rate,
9t = theoretical hydraulic detention time,
C° = recycle factor, and
X^ = mass or organisms leaving system per unit time/total flow leaving
system per unit time
In general, the value of Xw° is the weighted average of the organisms leaving
the solids separator in the effluent and in any sludge that would be wasted.
The value of C° is zero when all the organisms are recycled and one when no
recycle is used.
The above equations assume that the controlling substrate is nonsettleable,
thus, the substrate level in the system's effluent is the same as that in the
reactor. The equations can be modified to consider a settleable substrate,
as was observed to be the case in both the bench and pilot systems used in
the present investigation. The modified equations as used herein were
developed to account for the loss of substrate and biomass from the anaerobic
contact process in both sampling and sludge wastage streams as well as the
settleable character of the substrate. The modified forms of Equations 7 and
10 are as follows (no modifications were required to Equations 8 and 9) :
(11)
Y 0 _ Y°
Xl ~
y N y N fj ,r.I_-|J
Ao — A-i IJ. — r \\> -LJI
1 L J
v-Drt i po
K et + c
160
-------
and:
CO _ "w iv ^^S W Ł•
_ .-•-•_!. "-I---
where :
XR^ = recycle stream substrate concentration,
XR° = recycle stream (and sludge wastage stream) organism concentration,
Qs = sample flow rate (average) ,
Qw = sludge wastage flow rate,
C = degree of concentration of substrate in the solids separator
r = fraction of influent recycled,
and other symbology is as defined above. The physical significance of the
symbology associated with the above equations is illustrated in the process
flow sheet of Figure 1.
Operational Relationships
Equation 8 can be rewritten to formulate an operational relationship between
the effluent substrate concentration, X^N, of the anaerobic contact process,
and the basic design parameters, 0t (hydraulic residence time) and C° (re-
cycle factor), as follows:
9 K + X,N
C° (km-KD)XN - KKD
(13)
A plot of Equation 15 is presented in Figure 2, from which it is apparent
that, for a given set of kinetic constants and a specified effluent quality,
the ratio 9t/C° is specified. The relationship defined by Equation 13 is a
hyperbola which becomes asymptotic to an abscissa value equal to K%/ (km-KD)
and to an ordinate value equal to l/(km-KD). The value of KDK/ (km-KD) repre-
sents the minimum substrate concentration which can be realized in the
effluent and is obtained when C° is zero (i.e., 100 percent recycle of biomass)
or 9fc is infinity. The value of l/(km/K ) is approached as the effluent
substrate concentration (X-i^) approaches the influent concentration Xo^ t
i.e., when biomass washout occurs.
Several basic premises of the kinetic formulation for the anaerobic contact
process are embodied in this expression:
Effluent quality as predicted by Equation 13 is directly a function of
the viable biomass in the fermenter
Effluent quality is not a function of influent quality; the only way
that the biological process can respond to changes in the influent
quality (or more appropriately, to changes in the mass loading rate of
biodegradable matter) , is by an increase or decrease in the inventory
of viable biomass in the system
For any given 9t, an increase in C° results in a decrease in effluent
quality; a decrease in the value of C° results in an improvement in
effluent quality
161
-------
Zone of Unstable Performance
Zone of Stable Performance
9 /C", days
• I
Figure 2. Unified Operational Relationship For Anaerobic Contact
Process
162
-------
The basic objective of the design of an anaerobic contact system is to achieve
the 6t/C° ratio as specified by the desired effluent quality and the determined
kinetic constants for the least cost. The costs associated with 0t are the
tankage cost, the cost of mixing, and the optional cost of heating. The
costs associated with C° are those for the solids separator and the necessary
pumps and piping, and the power costs for operation of the separator and for
pumping. Thus, a consideration of the costs associated with the size of the
fermenter and separator, pumps and piping, mixing and power and other opera-
tional costs can be used to define the least cost region for a design of an
anaerobic contact process to realize the specified 9t/C° value.
The problems of operation are somewhat more arduous than those of design.
The net result of design is almost inevitably the specification of a fermenter
of fixed size (which provides the desired 9fc based on a design flow rate),
a solids separator of fixed solids handling capacity, and a capacity to vary
the quantity of underflow from the solids separator that is pumped back to
the fermenter. Thus, in effect, the only controllable operational variable
is C°. The major factors which affect C° are the effectiveness of the solids
separator in controlling the biomass concentration in the liquid effluent
from the separator, and the capacity to recycle biomass from the clarifier.
After the design of a solids separator has been established, its effectivenes
can be controlled only by the recycle rate and/or the addition of primary
coagulants or coagulant aids (i.e. polymers).
Three regions of operation can be defined with the operational curve for
the anaerobic contact process (Figure 2):
A zone of "stable" performance, in which a unit change in the 9t/C°
results in little change in the effluent quality.
A zone of transition or "unstable" performance, in which a unit change
in the 9t/C° value will generate significant change in the effluent quality.
A critical zone, in which effluent quality deteriorates rapidly.
Because as previously discussed, C° is typically the only operational variable
available, the anaerobic contact process has its greatest operational sensitivity
in the "unstable" zone. Thus, when the desired effluent quality is based on
a pretreatment or effluent standard (the most likely case), the objective of
the operation becomes primarily that of insuring that C° is equal or less
than the design value at all times. However, if the actual. 9fc is variable,
that is, if the actual flow rate deviates widely from the design flow value,
then the objective of operation is to vary C° such that at all times, the
ratio 9t/C° is equal to or greater than that necessary to provide the desired
effluent quality.
EXPERIMENTAL INVESTIGATIONS
The research effort was directed to documentation of the kinetic characteris-
tics of rum distillery slops by the anaerobic contact process, and to evaluation
of the clarification capacity required for gravity separation of mixed liquor
solids in a prototype treatment system.
163
-------
The kinetic characterizations were conducted using two bench scale anaerobic
contact systems and a pilot scale anaerobic contact system as described below.
The bench scale system was designed to provide a flexible tool for examining
anaerobic biological response over a range of hydraulic residence times
from five to 200 days. The pilot plant was designed to permit evaluation of
gravity settling both with and without upstream vacuum degasification of
fermenter effluents, gravity thickening, and hydrogen sulfide scrubbing
requirements associated with a prototype design, as well as to permit examina-
tion of anaerobic biological response.
Apparatus
A schematic flow diagram of the bench scale anaerobic contact unit is presented
in Figure 3, and a similar diagram for the pilot system is presented in
Figure 4.
The bench scale systems (two were utilized) each consisted of a 20 liter
completely mixed anaerobic fermenter, temperature-controlled at 33 to 36°C,
and a four liter gas and solids separator vessel. Each system was equipped
for continuous flow feeding, sludge recycle, and gas recycle. Feed was
pumped continuously from a refrigerated reservoir; flow traversed upward
through the reactor into the gas/solids separator, from which separated gas
and sludge streams could be pumped either back to the fermenter or to wastage/
storage.
The pilot plant consisted of the following:
A 1,130 liter (300 gallon) insulated slops storage tank used to hold
feed slops batches.
A 1,890 liter (500 gallon) insulated anaerobic fermenter, equipped
with: an electric heat tape system, thermostatically controlled to
maintain the temperature of the mixed liquor in the fermenter at 33 to
36°C; gas recycle at a rate of 0.15 standard cu m/min cu m of mixed
liquor (20 SCFM/1,000 gallons); and, liquid recycle at a rate of 0.06
cu m/min/cu m of mixed liquor (60 gpm/1,000 gallons).
Hydrogen sulfide scrubbers (two), each consisting of cylindrical tanks,
0.1 m diameter by 0.6 m in height (4-in diameter by 2-ft height), filled
with steel wool and designed for removal of approximately 1/2 kg elemental
sulfur per kg steel wool.
Vacuum degasifier, consisting of a cylindrical tank 0.15 m diameter by
0.6 m in height (6-in diameter by 2-ft height), providing for degasifica-
tion of the mixed liquor flow at a vacuum of 15 mm Hg.
A gravity clarifier/thickener, the key features of which were as follows:
the clarifier (conical) sector of the unit has a cross-sectional
area of one sq m (10. 7 sq ft) at the liquid surface and 0.21
sq m (2.2 sq ft) at the bottom of the cone.
effluent is withdrawn from the clarifier in four effluent funnels.
164
-------
To
Liquid
Effluent
Reservoir
(Refrigerated)
NOTE: Anaerobic Reactor
3 33-350 c
d«s Separator-
• Soli ds Separator
Vcisol (4 .0
Anaerobic
Fermenter
(20/)
'To
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Gas .-
Recycle (y)
Pump ^^
Sludge
Recycle
Pump
SIudge
Wastage
From Influent
Stream Reservoir
(Refrigerated)
Figure 3. Bench Scale Anaerobic Contact Unit
165
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166
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presenting a total weir length of 2.57 m (8.4 ft).
the thickener sector of the unit is equipped with a thickener screen
that can be rotated at a rate of 1/8 to 1/2 revolution/minute.
sludge withdrawal is accomplished by means of a variable speed
pump capable of a maximum sludge withdrawal rate of 985 liters/day
(260 gallons/day).
A 190 liter (50 gallon) mix-head tank and a stock polymer solution feed
tank; the mix-head tank was equipped with a constant head overflow (the
overflow being recycled directly back to the anaerobic fermenter);
stock ploymer solution was fed into the mix-head tank, and the contents
of this were mixed with a recycle pump at a rate of one volume every
five minutes.
During the first phase of pilot plant operations (evaluation of anaerobic
biological process kinetics), raw slops were fed from the slops storage tank
at preselected continuous flow rates, and flows of mixed liquor from the
anaerobic fermenter were transferred directly to the clarifier-thickener
(i.e., the flow path through the mix-head tank was not used). During the
final phase of pilot plant operations (evaluation of mixed liquor settling
characteristics), all mixed liquor flows were directed to the mix-head tank,
and from this point by gravity into the clarifier-thickener.
Both the bench and pilot systems were designed with the sampling ports
necessary to permit characterization of liquid volumes within each component
of the system, liquid and material transfer rates into, within, and from the
components of systems, and gas production rates.
Procedures
Process Kinetic Characterization - The biological process kinetic studies
were conducted in three phases; seed culture development; startup and
acclimatization of the bench and pilot scale units, and routine operations.
Seed cultures for use in the startup of the bench and pilot systems were prop-
agated in anaerobic vessels equipped with feed and sampling parts, and with
a gas release valve. Selected as a source of methanogenic material for starting
the seed cultures were the bottom mud of a brackish water inlet to San Juan Bay
(Puerto Rico); this inlet has received slops discharge from a distillery and
cooling water discharges from an electrical power generation station for a
number of years. The seed cultures were maintained by daily batch feeding of
gradully increased amounts of raw slops neutralized to pH 7.0 with sodium
bicarbonate. Daily observations were made on the pH of the seed culture and
the volume and composition of gas generated in each vessel. The first trace
of methane was typically observed within two to four weeks after initiation
of seed culturing and a minimum time of four months was allowed before the
seed cultures were transferred to the fermenters. After seeding, all three
units were fed neutralized undiluted slops at flow rates allowing hydraulic
residence times in excess of 30 days, to permit the buildup of MLVSS (mixed
liquor volatile suspended solids) concentrations to minimal levels of 300 mg/1.
167
-------
An evaluation of the operating experience acquired during the four month
period of acclimatization and buildup of a viable biomass inventory in each
of the anaerobic contact units led to the development of the following guidelines
for startup:
The maximal rate of slops feed should not exceed one kg soluble COD/
day/kg MLVSS if the buildup of volatile acids is to be avoided.
The pH of the mixed liquor should be maintained in the range of 7.2 to
7.3 at all times.
Continuous mixing of the fermenter contents should be provided.
After completion of the acclimatization phase of operations in each fermenter,
it was possible to sustain a methanogenic fermentation of undiluted and
unneutralized slops stream at a pH in excess of 7.0 during operations at
hydraulic residence times in excess of 20 days. Neutralization was required
to maintain a mixed liquor pH in excess of 7.0 at residence times below 20
days, indicative of a differential between required and internally generated
buffering capacity that increased with decreasing hydraulic residence times
at hydraulic residence times less than 20 days. During routine operations,
neutralization was accomplished, as needed, by the addition of sodium bicarbonate
directly into the bench and pilot scale fermenters.
Each of the biological systems was operated for a time period averaging
nine months, including the four month startup period. Throughout the nine
month period, weekly balances were performed on total and volatile suspended
solids (TSS and VSS), total and soluble COD, total nitrogen, and total phos-
phorus, on the feed stream, mixed liquor, effluent, and recycle stream of each
system. Daily observations were made on pH, alkalinity, volatile acid concen-
tration, and temperature of the mixed liquors in each system, and of the volume
and methane content of the gas generated in each fermenter.
Determination of Clarification Capacity
The objective of this phase of effort was to develop a relationship between
clarifier performance and loading rate that could be used to examine trade-
offs between recycle factor (C°) attainable, and a loading parameter from
which (1) the size and (2) the cost of the clarifier system could be established.
The pilot plant was modified for this final effort of the investigations to
permit the recycle of both settled solids and clarified effluent back to
the anaerobic fermenter — a measure necessary to conserve the essentially
fixed supply of mixed liquor solids available for the testing program. Also,
larger pumps were installed to permit the transfer of mixed liquor into the
mix head tank and thence by gravity into the clarifier, at clarifier surface
loading rates up to a maximum of 10. 2 cu m/day/sq m (250 gpd/sq ft).
A jar testing program was conducted with the objective of screening a wide
range of high and low molecular weight polymers, for use as a coagulant
aid to improve the settleability of the mixed liquor solids. As the basis
of jar testing, the polymer selected was Nalco 627, a moderately cationic,
high molecular weight polymer (10), with this polymer it was possible to
obtain in excess of 80 percent TSS removals in the jar test beakers after
30 minutes of quiescent settling at specific polymer doses varying from 1 to
168
-------
5 mg per gm TSS.
With the selection of a polymer and the development of dosing criteria, the
evaluation of clarification capacity was done as follows:
Laboratory zone settling assays were conducted to determine the solids
handling capacity of the limiting layer as a function of specific polymer
dose and initial TSS concentration in the suspension.
Two series of experimental runs were conducted with the modified pilot
plant to document the relationship between TSS removal efficiency and
solids loading rate; no polymers were used in the first series of runs
(as a control) and polymer addition was used in the second series.
The results of the zone settling assays were compared with the pilot
plant results in the selection of a design solids loading rate for full-
scale application.
RESULTS
Process Kinetics
The three biological systems were operated a total of 110 weeks, including
acclimatization operations over 16 week periods with each system. Exclusive
of observations made during the startup phases in each of the three units,
a total of 62 weekly sets of experimental data were available for use in the
kinetic characterization. This data set was screened to eliminate data points
not deemed representative of steady state operation. The criteria defined
for steady state operation were as follows: less than 15 percent variation
in flow rate, 10 percent variation in mixed liquor/effluent soluble COD con-
centration, 20 percent variation in mixed liquor/effluent VSS concentration,
and 20 percent variation in 9t/C°, based on average values of each during
three consecutive weekly periods. Based on these criteria, a total of 14
sets of experimental data representative of steady state were identified,
seven from operation of the two bench units, and seven from the pilot plant
operations.
The characteristics of the fermentations in these units at each steady state
point are summarized in Tables 1 and 2 and illustrated by the data presented
in Figure 5. The values of 9t/C° at which steady state was obtained varied
from 35 to 220 days, and the values of 9t (hydraulic residence time) varied
from 19 to 140 days.
The soluble COD loading rate, expressed in rational units of mass/time-mass
of MLVSS, varied from a minimum of about 0.26 kg/day/kg MLVSS (0.26 lb/day/
Ib MLVSS) at a 9t/C° of 220 days, to a maximum of 0.74 kg/day/kg MLVSS at a
9t/C° of 35 days. The soluble BOD loading rates corresponding to the above
were 0.059 kg/day/kg MLVSS at 9t/C° of 220 days, and 0.449 kg/day/kg MLVSS
at 9t/C° of 35 days. Thus, the maximum soluble COD loading rate observed
under steady state conditions (0.74 kg/day/kg MLVSS) was approximately 25
percent less than the maximal loading rate of 1 kg soluble COD/day/kg MLVSS
recommended for startup.
On a volumetric basis, the soluble COD loading parameter varied from a minimum
of about 0.4 kg/day/cu m (0.024 Ib/day/cu ft) at 9t/C° of 35 days, to a maximum
169
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of 3.44 kg/day/cu m (0.215 Ib/day/cu ft) at et/C° of 220 days, as shown in
Figure 5. The volumetric soluble BOD loading rates varied from 0.086 to
1.19 kg/day/cu m (0.005 to 0.074 Ib/day/cu ft), increasing with decreasing
0t/C° values in a pattern similar to that for the soluble COD pattern as
shown in Figure 5.
The alkalinity of the mixed liquors varied from 8,500 to 11,000 mg/1 @ CaC03,
and the pH levels varied from 7.11 to 7.32, the ranges of values of each of
these parameters reflecting the effect of buffer addition as necessary to
maintain the pH of the mixed liquors at about 7.2. The volatile acids con-
centrations in the fermentations varied from less than 100 mg/1 (as acetic
acid) at 9t/C° values in excess of 100 days, to maximal values of 600 mg/1
at 9t/C° values of 35 days. As shown by the plot of data on volatile
acids concentrations vs 9t/C° in Figure 5, the volatile acid concentration
tended to increase at an increasing rate with decreasing 9t/C° values.
The MLVSS (mixed liquor volatile suspended solids) concentrations (Table 1)
varied from a minimal level of about 1,500 mg/1 at 9t/C° of 220 days to maxi-
mal levels of 6,000 mg/1 at 9t/C° of 35 to 40 days. The volatile fraction of
the MLTSS (mixed liquor total suspended solids), i.e., ratio of MLVSS:MLTSS
concentrations for the steady state points varied between 0.55 and 0.73;
for all 14 data points the average volatile fraction was 0.67.
The soluble COD removal efficiencies in the three units at the steady state
points are reported in Table 2 and illustrated in Figure 5. The soluble
COD removal (influent-mixed liquor basis) increased with increasing 9t/C°
from a minimal value of about 65 percent at 9t/C° values in excess of 150
days. From a comparison of soluble COD removal efficiencies computed on
(1) an influent — mixed liquor basis and (2) an influent — separator
effluent basis (Table 2), it is evident that the additional soluble COD
removal obtained in the separator sector is insignificant relative to removals
obtained in the anaerobic fermenters.
The methane (Ctfy) content of the gas produced in the fermentations varied
from 53 to 60 percent, and averaged 57.4 percent for the 14 steady state
points. The methane production varied from 0.28 to 0.33 liters of CH^ per
gm of soluble COD removed (4.5 to 5.3 cu ft/lb soluble COD removed), and
averaged 0.302 liter/gm soluble COD removed (4.8 cu ft/lb soluble COD removed)
for all observations. That is, an average of 86.3 percent of the soluble
COD (or about 82 percent of the total COD) removed from the feed stream was
recovered in the form of methane during the steady state observations.
Determination of Process Kinetics - For purposes of determining the kinetic
constants, it was assumed that the VSS parameter represented viable biomass
concentration (X,°), and the soluble COD parameter represented the rate
controlling substrate concentration (X-^ ). Linear forms of Equations 11 and
12 were used to analyze the data. From Equation 11:
173
-------
X? - X? [l-r(C"-l)]
From Equation 12:
e
m
km
X
.N
(15)
Presented in Figure 6 is a plot of Equation 14, in which the intercept is the
inverse of the value of Y°, and the slope represents the ratio KD/Y°. The
steady-state data are presented in Figure 7 for determination of the values of
K and km using Equation 15. The intercept of the straight line fit in Figure 7
is the inverse of the value of km, and the slope is equal to K/km.
The values of the kinetic constants obtained from this analysis are
as follows:
Y°
KD
K
km
0.225 mg VSS/mg soluble COD
0.0667 days"1
12,270 mg/1 soluble COD
= 0.129 days
'1
In order to provide some basis of comparison for the values of the kinetic
constants, a summary of the kinetic constants determined in this and prior
studies is presented in Table 3. Included in Table 3 are data for a packing-
house waste (11, 12), synthetic milk waste (8), and the results reported by
Andrews and Pearson (13) .
The value of km for the slops and synthetic milk wastes are similar
in magnitude (0.13 days ) . Given the 10°C difference in temperature used
in these two studies, it was anticipated based on observations by Schroepfer
and Ziemke (11, 12) that the anaerobic stabilization rate for the slops
would have been about double that for the synthetic milk waste. However, since
the temperatures used by Andrews and Pearson (13) , Schroepfer et al (11) , Schroep-
fer and Ziemke (12), and in this study were nearly equal, it would appear that
km is influenced by substrate composition as well as temperature.
The Kr value obtained for slops treatment by the anaerobic contact
process is nearly equivalent to that reported for the synthetic milk waste (8) .
The Y° value obtained for rum slops is greater than that reported by Andrews
(13) for the methane organism dominated system and less than that reported
by Gates jet al (8) for the synthetic milk waste. The variation in Y° value
appears to be attributable both to temperature and to different relative
combinations of organisms existing in the different systems. The K value for
the rum slops is several hundredfold greater than the value reported for the
other wastes. That K did change with temperature and/or substrate composition
is apparent; however, too little is known about the effect of transport-
controlled mechanisms to support any definite conclusions about the impact
of the environment on K.
174
-------
Q
O
O
0)
CT)
CO
o
x
80
70
60
50
40
30
20
10
Notes: APilot plant
OB/S #1
DB/S #2
1/Y
KD/Y°
Y° = o
Y U'
mg soluble COD
K° = 0.0667 days"1
50
100
150
200
250
9y/C , days
Figure 6. Rum Distillery Slops Treatment by Anaerobic Contact Process-Determination
of Values of Y° and KD for steady-state Data
175
-------
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0)
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n)
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H cu
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en co
a, -u
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I
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)-i 0)
(U iJ
rH cyj
rH
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e v
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stop
ea>i
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176
-------
Table 3. Values of Constants in Various Studies
f
Source
Packinghouse waste
(11, 12)
Anaerobic digester
(13)
Acid-formers
Methane Formers
Synthetic Milk
Waste (8)
Rum Slops
(this Study)
Constants
i
km(days-l) i KD(days~l) K(i
0.25
1.33
I
]
0.17
0.87
•
1.33* 0.02
0.14 i 0.07
mg/VSS
ag COD/1)
-------
Operational Relationship - Equation 13 and the values of the constants for
rum slops treatment by the anaerobic contact process were used to formulate
the operational relationship defining process performance as a function of 9fc
and C°, as presented in Figure 8. The measure of process performance is the
soluble COD concentration of the process effluent, X,N. The operational
relationship is a hyperbola which becomes asymptotic to an abscissa value
equal to KDK/(km-KD) and to an ordinate value equal to l/(km-KD). The equa-
tion describing the operational relationship is as follows:
12.270 + XT ,
v '
_
C° ~ 0.0623 Xj_N - 818
The value of the abscissa asymptote represents the minimum effluent substrate
concentration which can be obtained when C° is equal to zero (i.e., 100
percent biomass recycle), or when 9t is infinity. The value of the ordinate
asymptote is approached as the effluent substrate concentration X^N approaches
the influent concentration (XoN) , i.e., when biomass washout occurs. In
the present case (treatment of rum distillery slops) these asymptotic values
are X^ = 11,430 mg/1 and et/C° =14.7 days, respectively.
Three regions of operation can be defined with the operational curve (Figure
8) for rum slops treatment by the anaerobic contact process:
A zone of stable operation (small ratio of AX^: A9t/C°), existing at 9t/
C° values greater than 75 days.
N
A zone of transition (in which X-^ varies significantly with changes in
9t/C°), existing at 9t/C° values between 40 and 75 days.
A zone of instability (occurring at 9t/C° values less than 40 days) ,
in which the effluent quality rapidly deteriorates.
Within the zone of stable operation, effluent soluble COD concentrations of
less than 20,000 mg/1 were obtained with the anaerobic contact treatment of
rum slops. This effluent concentration is equivalent (for a slops feed
stream concentration of 80,000 mg/1 soluble COD), to a soluble COD removal
efficiency of 75 percent.
Clarification Capacity
Both laboratory zone settling tests and pilot clarification tests were conducted
to permit the development of the desired relationship between clarifier TSS
removal efficiency and solids loading rate.
Zone Settling Tests - The results of the six zone settling assays, conducted
using three initial MLTSS concentrations and two polymer doses per initial
MLTSS concentration, are presented in Table 4. The actual MLTSS concentrations
at which the tests were conducted were approximately 7,500 mg/1, 12,000 mg/1,
and 28,000 mg/1, the lower and upper vlaues being representative of the anti-
cipated range of MLTSS concentrations to be carried in a full scale application.
The data on solids loading rate in the limiting layer (Table 4) were calcu-
lated using the zone settling curves (plots of interface height vs settling
time) for each test, and an assumed underflow concentration of 50,000 mg/1
(TSS) . The allowable liquid loading rate was then calculated from the initial
MLTSS concentration and solids handling rate data for each test. The allowable
liquid loading rate and initial MLTSS data have been plotted in Figure 9 to
178
-------
3E —
E
CD
X
01
o
c
o
o
Q
O
O
O)
I—
.a
3
c.
O)
4-
M-
2(
15
10
A
Notes:
API lot plant
OB/S #1
TIB/S #2
9T _ 12,270 + X!
C° 0.0623 XiN
N
- 818
^= 11,430 mg/1 @ 0T/C
50
100 150
9T/C°, days
200
250
Figure 8. Unified Operational Relationship for Rum Distillery Slops Treatment
by Anaerobic Contact Process
179
-------
Table 4. Summary of Zone Settling Data
Test #
1
2
3
4
5
6
Initial
MLTSS
(mg/1)
6,770
6,295
12,850
11,635
30,527
26,594
Poly-
mer dose
(mg/gm)1
1.44
7.25
1.06
5.26
0.63
3.15
Solids Loading
in Limit. Layer
(KG/day-sq m)2
178
112
293
381
317
1,001
Allowable
Liquid
Loading Rate
(cu m/day/sq m)
26.4
17.9
22.8
32.8
20.5
37.7
Superna-
1 tant TSS
(mg/1)3
1,450
i 3,130
1,200
• 1,700
2,230
2,930
% TSS
Removal
78.5
50.2
90.7
85.4
92.7
89.0
;
Notes: "alco 627
^Assumed underflow TSS concentration - 50,000 mg/1
•^Sampled after 30 minutes of settling
180
-------
36
32
28
24
20
(O
O
o
O)
(O
CD
c
-o
rO
O
cr
Ł 16
O)
(O
o
12
10
°3.15
o
5.26
.1.44
•ol.06
Best fit curve @ specific
polymer dose of 0.5 to
1.5 mg/gm
7.25
Notes:
1. Specific polymer dose, mg NALCO 627/
gm MLTSS, as noted
2. Assumed underflow at 5% TSS
8 12 16 20
Initial TSS concentration, gm/1
24
28
Figure 9. Allowable Mixed Liquor Surface Loading Rate vs. MLTSS Concentration
Zone Settling
181
-------
determine, for the laboratory data, a relationship between maximum rate of
clarification as related to the settling velocity of the limiting layer, and
initial MLTSS concentration.
A trend can be defined from the data presented in Figure 9 between allowable
liquid loading rate and initial MLTSS concentration at the lower range of
polymer doses (0.63 to 1.44 mg/gm MLTSS); this trend is exemplified by the
best fit curve in Figure 9. Based on this curve, the allowable liquid loading
rate decreased at an increasing rate with increasing initial MLTSS concentration
from 26 cu m/day/sq m (635 gpd/sq ft) at an initial concentration of 7,000
mg/1 to 11.5 cu m/day/sq m (260 gpd/sq ft) at 30,000 mg/1.
While insufficient points were available to define similar trends for liquid
loading rates associated with the high polymer doses, it is apparent from the
data presented in Figure 9 that, at polymer doses greater than 1.5 mg/gm
MLTSS, the allowable liquid loading rate at any given MLTSS concentration
increased with increasing polymer dose to a maximal level at a polymer
dose of about 3 mg/ym, and then decreased with increasing polymer dose to a
minimal level at the polymer dose of 7.25 mg/gm, in comparison with the
results obtained at polymer doses in the range of 0.63 to 1.44 mg/gm. The
decrease in polymer effectiveness with increased polymer dose is also evidenced
by the TSS removal efficiency data presented in Table 4, i.e., the percent
removal of initial MLTSS as determined by sampling the supernatants after
30 minutes of settling decreased from 85 percent at a polymer dose of 5.26
mg/gm MLTSS to 50 percent at a dose of 7.25 mg/gm. Thus, the results of the
zone settling assays confirmed the conclusions from the jar testing that the
polymer selected (Nalco 627) would be effective at doses from 1 to 5 mg/gm
MLTSS.
Pilot Plant Clarification Tests - The pilot plant clarification tests were
conducted in two series of runs, the first series without polymer addition,
the second series with polymer addition, in the developing of efficiency vs.
loading relations for each operating mode. A summary of the results obtained
in each series/run is presented in Table 5, and the relationships between
solids removal efficiency and solids loading rate derived from these results
are presented in Figure 10.
The information presented in Table 5 includes: run duration; average cumulative
polymer dose; liquid and solids loading rates; and average MLTSS removal
efficiency over the duration of the run. The average cumulative polymer
dose reported in Table 5(Series II) is equal to the cumulative mass of polymer
added per mass of MLTSS in the entire pilot plant system, averaged over the
run duration; the actual rate of polymer dosing into the mixed liquor stream
during the Series II runs was paced at from one to three mg polymer per gm
of MLTSS transferred into the mix-head tank. The "overflow" liquid and solids
loading rate data reported in Table 5 were calculated on the basis of the
clarified effluent flow rate, and the "total" liquid and solids loading rate
data were calculated using the sum of the clarified effluent and sludge
recycle flow rates. The influent MLTSS concentrations averaged about 11,000
mg/1 during the Series I runs and 14,000 mg/1 during the Series II runs; the
solids loading rates for each run were computed using the corresponding
liquid loading rates and influent MLTSS concentrations as reported in Table 5.
182
-------
Table 5. Summary of Results-Pilot Plant Clarification Tests
i
t
| Ave
| Run Cumu
Series Duration 1 Pol
run i(hours) Do
5 » f —
1
1-1 i 1.0
i
1-2 j 4.0
II-l i 2.0
2 3.0
3 1.5
i
4 4.0
t
5 ! 1.5
i
i
i
;
i
i
\
i
i
: 0.
: 0.
i 1.
i
; 1.
5.
rage
lative
ymer
sea
—
29
80
20
85
91
Liq Load Rates
(cu m/da/sq m)
Dverf low! Totalb
basis • basis
2.63
7.96
8.45
7.65
5.08
5.03
4.86
i 5.
10.
1
i 11.
10.
7.
7.
7.
48
8
3
5 i
94
88
71
Sol Load Rate
(kgMLTSS/da/sqm)Influent
Overflow Totalb
basis basis
48.
88.
124
102
73.
69.
63.
0
5
5
6
7
100.0
120.3
165
140
115
109
101
MLTSS
(mg/1)
10,833
11,144
14,660
13,330
14,500
13,880
13,150
Average
MLTSS
Removal
Efficiency
21.
8.
45.
49.
36.
50.
68.
8
8
3
8
7
1
6
Notes: Cumulative mass of polymer (Nalco 627) added per mass of MLTSS
in pilot plant
3Based on overflow as clarified effluent plus sludge recycle flow
183
-------
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184
ft
-------
The effectiveness of the polymer addition in improving the settleability
characteristics of the mixed liquor solids is evident from the relationships
presented in Figure 10 for the Series I and II data. In the Series I
relationship, the TSS removal efficiency decreased from 22 percent at a
solids loading rate (overflow basis) of 48 kg/day/sq m (9.8 Ibs/day/sq ft)
to a level of 8 percent at a solids loading rate of 88.5 kg/day/sq m
(18 Ib/day/sq ft); i.e., the mixed liquor solids were effectively unsettleable
at these solids loading rates. With polymer addition in the Series II runs,
the TSS removal varied from an average of 52 percent at a solids loading rate
of about 70 kg/day/sq m (14.3 kg/day/sq m) to 45 percent at 120 kg/day/sq m
(24.6 Ib/day/sq ft). The solids loading rates of 70 and 120 kg/day/sq m
were equivalent to liquid loading rates (overflow basis) of 5 cu m/day/sq m
(123 gpd/sq ft) and 8.4 cu m/day/sq m (205 gpd/sq ft) respectively. Addi-
tionally, at the solids loading rate of 70 kg/day/sq m, the TSS removal effi-
ciency tended to increase with increasing cumulative polymer dose in the
pilot plant system, varying from 37 percent at a cumulative dose of 1.2
mg/gm to nearly 70 percent at a cumulative dose of 5.9 mg/gm.
Based on the preceding observations, it is evident that polymer addition is a
requisite for any full-scale application, and that the "residual" effect of
the polymer recycled in the system (as measured in the present study by the
average cumulative dose), was beneficial, within the range of average cumu-
lative doses at which the tests were made, to the settleability of the mixed
liquor solids.
A major equipment limitation in the pilot plant, which could not be resolved
in the course of the pilot plant testing, was the clogging of several of the
funnel weirs in the clarifier, the result of which was the availability of
0.32 m (1.05 ft) of the design weir length of 2.57 m. As a result, the
weir loading rates varied from approximately 15 cu m/day/m (1,210 gpd/ft) to
26.4 cu m/day/m (2,120 gpd/ft) during the Series II runs. While these
weir loading rates are low in comparison with the weir loading rates used in
design of primary sedimentation tanks (greater than 50,000 gpd/ft), the
malfunction of the funnel weirs disrupted the flow distribution pattern at the
surface of the clarifier. Because of the short circuiting of the surface
flow pattern in the clarifier, and the associated disuption of quiescent
settling within the clarifier, it is anticipated that clarifier performance
on a full-scale application can be increased at least 20 percent by the careful
design of the flow pattern in the clarification units, and the use of weir
loading rates of less than 12.4 cu m/day/m (1,000 gpd/ft).
A comparison can be made between the zone settling results and the pilot
plant clarification tests by using the curve of Figure 9 to determine the
allowable solids loading rate as the product of the allowable liquid loading
rate and initial TSS concentrations. The allowable solids loading rate in
the initial TSS concentration range of 10,000 to 14,000 mg/1, as determined
from the zone settling results, is 239 to 302 kg/day/cu m (49 to 62 Ibs/day/
sq ft). Allowing a scaleup factor of 3 to 4 conservatively account for
scaleup differences (hydrodynamics) between the laboratory apparatus and the
pilot plant, then a comparability of clarification efficiency at the pilot
scale would be expected at a pilot plant solids loading rate (overflow basis)
of 80 to 100 kg/day/cu m (16.4 to 20.5 Ibs/day/sq ft). Given the stability
of pilot plant performance observed over this range of pilot plant solids
loading rates (Figure 10), and in consideration of the above cited short
circuiting problem in the pilot plant clarifier, the comparability of the
185
-------
zone settling results and the pilot plant results was reasonable. On this
basis, it was concluded that, with a properly designed full-scale clarification
unit, a clarification efficiency of 70 percent can be attained at a solids
loading rate of 100 kg/day/sq m (20.5 Ibs/day/sq ft), and, a weir loading
rate of 12.4 cu m/day/m (1,000 gpd/ft) or less, with polymer doses in the
range of 1 to 5 mg/gm MLTSS in the clarifier influent stream.
DESIGN AND OPERATIONAL ANALYSIS
The results of the bench and pilot studies and the process kinetic relationships
were used in the selection and specification of a steady state operating
region for the application, from which a process flow sheet and design
criteria for the physical system were developed.
Steady-State Operating Region
The specification of a steady-state operating region requires (1) the selection
of a desired effluent quality, (2) determination of the 0t/C° value for this
effluent quality from the relationship of Figure 8 (3) selection of a value
of C° and the associated solids loading rate from the clarifier efficiency/
loading relationships of Figure 10, and (4) calculation of the design 0t
value for the values of 6t/C0 specified and C° selected. The specification
can then be completed using the above 9t/C° values, the process kinetic
constants, and the kinetic relationships presented earlier.
The selected treatment objective, i.e., the desired effluent quality in a
full scale application, will vary with factors such as effluent standards,
additional treatment required, existing facilities available, etc. The
treatment objective selected as the basis for example process specification
subsequently is a design effluent soluble COD concentration of 29 gm/1, for
which a et/C° value of 40 days is specified (Figure 8). This design "point"
was selected because it represents the lower limit of the zone of transition
in the operational relationship and because of the demonstrated stability of
the anaerobic contact process at 9t/C° values in excess of 35 days. A C°
value of 0.375 (equivalent to a TSS removal efficiency of 62.5 percent), and
a solids loading rate of 100 kg/day/sq m (approximately 20.5 Ibs/day/sq ft)
were selected as design values based on the pilot plant clarification testing
results. For the selected values of et/C° @ 40 days and C° @ 0.375, the
required hydraulic residence time, 0t, is 15 days.
In the specification of the steady-state operating region for the above
conditions, the following relationships and parameter values were used:
Ratio of effluent soluble COD: total COD concentration =0.95
Volatile fraction of MLTSS =0.67
Methane production factor=0.30 liter CH^ per gm soluble COD removed
Average methane content of gas stream = 60 percent
Design influent COD concentration = 100 gm/1
Thus, for the selected design point:
The required MLVSS concentration is equal to 6,915 mg/1, and the MLTSS
concentration corresponding to this MLVSS concentration is equal to 10,320
mg/1.
186
-------
At the above MLVSS concentration, and a design hydraulic residence time
of 15 days, the required MLVSS inventory is equal to 104 kg MLVSS per
cu m/day of slops treated (865 Ibs MLVSS per 1,000 gpd of slops heated).
The rational organic loading rate is equal to 0.964 kg soluble COD/day/
kg MLVSS, and the corresponding volumetric loading rate is equal to
6.67 kg/day/cu m (0.416 Ib/day/cu ft).
The methane gas production rate is estimated to be 21.3 cu m CH^ per cu m
of slops treated (2,850 cu ft CIfy per 1,000 gal); for an average methane
content of 60 percent in the gas stream, the gas production is equal to
35.5 cu m per cu m of slops treated (4,750 cu ft per 1,000 gal).
The waste MLVSS production is equal to 2.60 kg per cu m of slops treated
(21.7 lb/1,000 gal), and the waste MLTSS production is equal to 3.87
kg per cu m of slops treated (32.4 lb/1,000 gal).
The clarifier liquid loading rate specified at a design solids loading
rate of 100 kg MLTSS/day/sq m, and an influent MLTSS concentration of
10,320 mg/1, is 9.7 cu m/day/sq m (238 gpd/sq ft).
At a C° value of 0.375 (design MLTSS removal efficiency of 62 1/2
percent), the estimated TSS concentration in the clarifier effluent is
3,870 mg/1.
From the perspective of operation of the anaerobic contact process in any of
its three stages (startup, routine operation, and reinitialization), the
common factors of concern are the operating objectives used and the environ-
mental and control variables available to the operator in each stage. Because
a common goal to each stage of operation is the attainment and/or sustenance
of steady-state operation, the specification of operatinb objectives common
to each stage can be done in consideration of the preceding analysis of the
steady-state operating region.
As stated earlier, the only way that process control can be effected is by
control of the viable biomass inventory in the system, and the single trans-
ferrable parameter specifying the viable biomass inventory in the system is
0^/0°. Thus, in the present case, the primary operating objective is the
maintenance of a 9t/C° value of 40 days at any point in any stage of operation,
if the selected design effluent quality is to be maintained. To meet this
objective requires, for a design C° value of 0.375, the attainment of an
MLVSS inventory of 104 kg MLVSS per cu m/day of slops treated (865 Ib MLVSS
per 1,000 gpd) during startup, and the maintenance of this inventory during
routine operation and reinitialization (should the latter be necessitated by
seasonal production schedules). The secondary operating objective common to
each stage is the provision of temperature, pH, and mixing at levels as
specified below on the basis of operating experience:
Temperature to be maintained at 35 + 2°C.
pH to be maintained at 7.2.
Complete and continuous mixing; the capacity of gas mixing provided in
the pilot plant system (0.15 cu m/min/cu m of mixed liquor, or 20 SCFM/
1,000 gallons) was sufficient to accomplish this.
187
-------
A final operating objective, common only to the startup and reinitialization
stage, is the pacing of the rate of pretreated (neutralized, phosphorus-amended)
raw slops at rational loading rates not to exceed 1 kg soluble COD/day/kg MLVSS
until the required biomass inventory for the selected design point is attained
in the fermenter.
Process Flow Sheet and Design Criteria
The process flow sheet and design criteria for full scale rum distillery slops
treatment by the anaerobic contact process were developed in consideration of
the preceding evaluations and the base of operating experience accrued
during the investigation. The process flow sheet is presented in Figure 11,
and the recommended design criteria are summarized in Table 6, and discussed
below:
Unit Processes/Operations - The function of the slops storage tank is to
provide equalizing of hour-to-hour flow variation, and to permit the cooling
of the slops stream emanating from the distillation columns to a temperature
of 32 to 38°C. The excess sensible heat in this tank can be used to maintain
the digester temperatures at 35 + 2°C, as an option to using a portion of the
methane gas production for this purpose. A minimum storage capacity of one
cu m per cu m/day of slops flow (1,000 gal per 1,000 gpd slops flow) is
suggested, exclusive of situation-specific storage requirements for reinitiali-
zation should the latter be required.
The digester capacity required at the selected hydraulic residence time of
15 days is 15 cu m per cu m/day of flow (2,000 in ft per 1,000 gpd), and a
minimum of two digesters should be provided for operational flexibility. The
digesters should be heated to 35 + 2°C. A gas mixing capacity of 0.15 cu m/
min/cu m of digester volume (20 SCFM/1,000 gal) is suggested as a criterion
for full scale design based on the satisfactory pilot plant experience at this
level.
The clarifiers should be sized to provide for a solids loading rate of 100
kb/day/sq m (20.5 Ibs/day/sq ft), which, at an MLTSS concentration of 10,320
mg/1, is equivalent to a liquid loading rate (overflow basis) of 9.69 cu m/
day/sq m (238 gpd/sq ft). A recycle ratio of at least 2:1 (ratio of slops
feed flow: sludge recycle flow) is recommended based on the experience of
Steffen and Bedker (14) in a slaughterhouse waste/anaerobic contact process
application; for a recycle ratio of 2:1, the TSS concentration in the recycle
stream is equal to 13,550 mg/1, and the design liquid loading rate (total
basis) is equal to 29 cu m/day/sq m (713 gpd/sq ft). A design weir loading
rate not to exceed 12.4 cu m/day/m (1,000 gpd/sq ft) is recommended on the
basis of pilot plant experience.
In the specification of criteria for the thickener, it was assumed that: the
settled solids can be thickened at a loading rate of 122 kg/day/cu m (25
Ibs dry solids/day/sq ft); and that the thickened sludge will have a dry
solids concentration of 10 percent. These values were selected on the basis
of design parameters typically associated with the thickening of primary
sludges in municipal wastewater treatment plants.
The functions intended for the waste sludge storage are to (1) provide waste
sludge storage for a reserve sludge quantity equal to one-third of the biomass
188
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c
-a
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Table 6. Design Criteria for Anaerobic Contact Process
Process Element
Slops storage tank
Digesters
1. Capacity
2. Gas Mixing
3. Heating
Clarifiers
1. Liquid loading rate
(overflow basis)
2. Weir loading rate
3. Recycle ratio
Waste sludge storage tank
Thickeners
1. Dry solids loading rate
Gas handling system
Sulfide Stripper
Chemical feed systems
1. Lime
2. Phosphorus
3. Polymer
Recommended Design Criteria (Units as Noted)
1 cu m per cu m/day
slops flow
15 cu m per cu m/day
slops flow
0.15 cu m/min per cu m
digester cap.
35 + 2°C
9.69 cu m/day/sq m
12.4 cu m/day/m
2:1
0.52 cu m per cu m/day
slops flow
122 kg/day/sq m
36 cu m of gas per cu
1,000 gal per 1,000 gpd
slops flow
2,000 cu ft per 1,000
gpd slops flow
20 SCFM/1,000 gal diges-
ter volume
95 + 3°F
238 gpd/sq ft
1,000 gpd/ft
2:1
70 cu ft per 1,000 gpd
slops flow
25 Ibs/day/sq ft
4,750 cu ft of gas per
1,000 gpd slops flow
0.43 kg S per cu m/ day 3.6 Ib S per 1,000 gpd
slops flow slops flow
4 kg CaO per cu m/day of 33.3 Ibs CaO per 1,000
slops flow gpd slops flow
0.3 kg P per cu m/day 2.5 Ibs P per 1,000
slops flow gpd slops flow
15 gm per cu m/day slops 0.125 Ib per 1,000 gpd
flow slops flow
190
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inventory in the digesters, to be available for transfer to the digesters
as needed; and (2) to provide interim sludge storage prior to haulaway.
The MLVSS biomass inventory required (104 kg MLVSS per cu m/day of slops
heated), at a volatile fraction of 0.67, is equivalent to an MLTSS inventory
of 155 kg MLTSS per cu m/day. For the storage of one third of this inventory
in the waste sludge storage tank, at an average concentration of 10 percent
solids, the storage capacity required is equal to 0.52 cu m per cu m/day of
slops treated (70 cu ft/1,000 gpd). At a waste MLTSS production rate of 3.87
kg/day per cu m/day, the waste sludge storage capacity provided is sufficient
to store 13 days of waste sludge production.
The gas handling system should be sized to handle 36 cu m of gas produc-
tion per cu m/day of slops treated. Assuming that the gas stream contains
0.8 percent hydrogen sulfide by volume, then the sulfide stripper should be
sized to handle 0.43 kg elemental sulfur per cu m/day of slops flow (3.6 Ib
per 1,000 gpd of slops flow).
Chemical feed systems are required for addition of lime, phosphorus
and polymer; it is suggested that these systems be sized as follows
(1) Lime - feed at 4 kg as CaO per cu m/day of slops flow (33.3 lbs/1,000 gpd)
(2) Phosphorus - feed at 0.3 kg as P per cu m/day of slops flow (2.5 Ibs
as P/1,000 gpd)
(3) Polymer - feed at 15 gm polymer per cu m/day of slops flow (0.125 Ib
polymer per 1,000 gpd)
Layout
The layout as exemplified by the process flow sheet of Figure 11
incorporates the following material/liquid transfer capabilities:
from either digester to another or the same digester,
from the waste sludge storage tank to the digesters or to sludge haulaway,
from the digesters to the clarifier,
from the clarifier to the thickener, the waste sludge storage tank, and/or
directly to the digesters
The above transfer capabilities are required to support the types of material/
liquid transfers required in the operational phases discussed earlier.
ECONOMIC ANALYSIS
Estimates of capital and 0/M (operating and maintenance costs) (January,
1974) for rum distillery slops treatment by the anaerobic contact process
were developed at two design capacities, 190 cu m/day (50,000 gpd) and 1,140
cu m/day (300,000 gpd), respectively, using the design criteria of Table 6 and
process flow sheet of Figure 11 as the costing basis. The heating require-
ments for the digesters at each design flow rate were then estimated in con-
sideration of ambient conditions in Puerto Rico, wherein most of the North
American rum distilling capacity is located, and the value of the energy
available as methane byproduct (after digester heating requirements were
deducted) was assumed to be equal to the cost of purchasing an equivalent
191
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amount of energy in the form of fuel oil. The cost estimates at each design
flow rate were then converted to unit treatment costs ($/volume treated,) from
which a cost capacity relationship, incorporating the value of the methane
byproduct as a function of fuel oil price, was constructed.
Economic Value of Methane Production
The factors considered in determining the economic value of the methane
production were;
The gross methane production,
The allocation required, from the gross methane production, to heat
the digesters,
The net methane production, i.e. the excess available after deduction
of the digester heating requirement from the gross methane production.
The first step in the evaluation was the estimation of digester heating
requirements at each scale. The requirements were estimated using the
procedure of Babbitt and Baumann (15) and the following assumptions (assuming
location of the facilities in Puerto Rico):
Average ambient temperature: 21°C (70°F)
Digester feed stream and sludge recycle stream temperatures: 27°C (80°F)
On this basis, the estimated BTU requirements for digester heating were:
2.45 x 109 BTU/year at the design capacity of 190 cu m/day; and 13.8 x 109
BTU/year at the design capacity of 1,140 cu m/day. Given that a barrel of
fuel oil has a BTU equivalent of approximately 6,000,000 BTU's, the pre-
ceding BTU requirements for digester heating are equivalent to fuel oil
consumption rates of: 408 bbl/year at a design capacity of 190 cu m/day;
and 2,300 bbl/year at a design capacity of 1,140 cu m/day.
The fuel oil equivalent of the gross annual methane production was estimated
using the following:
The gross methane production factor of 21.3 cu m CH^ per cu m slops
treated (2,850 cu ft per 1,000 gallons treated).
An energy equivalent of 1,000 BTU/cu ft of methane, or 5.90 bbl of fuel
oil/1,000 cu m of methane (0.167 bbl of fuel oil/1,000 cu ft of methane).
An assumed annual production schedule of 300 days.
For these conditions, the fuel oil equivalent of the gross annual methane
production is 37.7 bbl/year per cu m/day of capacity (143 bbl/year per 1,000
gpd); i.e., is equal to 7,160 bbl/year at a design capacity of 190 cu m/day
(50,000 gpd), and 42,900 bbl/year at design capacity of 1,140 cu m/day
(300,000 gpd).
The allocation of gross methane production required for digester heating
purposes can be evaluated by comparing the ratio of fuel oil equivalent
consumption for digester heating with the above fuel oil equivalent production
rates, at each design scale. This ratio is equal to 408/7, 160 (5.7 percent)
at 190 cu m/day capacity, and 2,300/42,900 (5.4 percent at 1,140 cu m/day
capacity). Thus, at either scale, less than six percent of the gross methane
production must be allocated for digester heating, and the net methane pro-
192
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duction is equal to at least 94 percent of the gross methane production.
At 94 percent, the fuel oil equivalent of the net methane production is
equal to 35.4 bbl/year per 1,000 gpd). On a dollar basis, this fuel equi-
valent is worth $0.119 per cu m of slops treated ($0.45/1,000 gallons treated)
for each $/bbl fuel oil cost on the open market.
TREATMENT COSTS
Annual treatment costs ($/cu m or $/l,000 gal of slops treated) were esti-
mated on an unadjusted basis (assuming a fuel oil value of $0/bbl) and on an
adjusted basis assuming fuel oil values up to $28/bbl. A summary of the
unadjusted annual costs at each design flow rate is presented in Table 7.
The capital and operating costs at each design scale reported therein were
obtained from detailed cost estimates presented in the final project report
(16). The amortization cost in Table 7 were developed assuming an interest
rate of eight percent, a 15-year life for 40 percent of the capital invest-
ment , and a 25 year life for 60 percent of the capital investment.
The unadjusted total annual cost of the full scale applications is $212,800
at the design capacity of 190 cu m/day (50,000 gpd), and $726,500 at 1,140 cu
m/day (300,000 gpd). For a 300 day production schedule, the unadjusted total
annual costs are equivalent to unit treatment costs of: $3.74/cu m treated
($14.18/1,000 gallons treated) at the design capacity of 190 cu m/day; and
$2.13/cu m treated ($8.07/1,000 gallons treated at the design capacity of
1,140 cu m/day.)
The unadjusted unit treatment cost data of Table 7 were used to construct the
cost vs capacity curve of Figure 12 at the fuel oil value of $0/bbl. The
adjusted unit treatment cost curves of Figure 12, at fuel oil prices of $4
to 28/bbl in $4/bbl increments, were developed by deducting $1.80/1,000
gallons treated for each $4 increment from the unadjusted costs, using the
factor for value of fuel oil equivalent presented above.
The significance of design capacity and fuel oil price on the unit cost of
rum distillery slops treatment by the anaerobic contact process are clearly
evident from the cost curves of Figure 12. The unit treatment cost (in
units of $/l,000 gallons treated) is $.80 less in a 100,000 gpd facility than
in a 50,000 gpd facility and an additional $3.30 less in a 300,000 gpd facility
than in a 100,000 gpd facility, for any given fuel oil price. If it is
assumed (conservatively) that fuel oil prices will soon average $12/bbl,
then the incorporation of methane byproduct recovery in a plant scale instal-
lation can reduce unit treatment costs from 35 percent (in a 50,000 gpd
facility) to 65 percent (in a 300,000 gpd facility), as compared with unit
treatment costs for installations without recovery.
CONCLUSIONS
The conclusions of the present investigation of rum distillery slops treat-
ment by the anaerobic contact process are as follows:
1. Rum distillery slops are amenable to treatment by the anaerobic contact
process.
2. The Monod model describes the response of the anaerobic contact process
for the treatment of rum distillery slops even when engineering-type
193
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Table 7. Unadjusted Annual Costs for Rum Distillery Slops Treatment by
Anaerobic Contact Process
Capacity @ Capacity @
190 cu m/day 1,140 cu in/day
Item (50.000 gpd) (300.000 gpd)
Capital costs $1,683,200 $5,596,300
Annual costs ($/year)
Amortization1 173,269 576,083
0/M costs 39,500 150,400
Total annual cost2 212,769 726,483
Unit treatment costs
Per cu m treated 3.75 2.13
Per 1,000 gallons treated 14.18 8.07
1Amortization at 8% interest rate; 15 year life for 40% of capital invest-
ment and 25 year life for 60% of capital investment
^Exclusive of methane credit
on 300 day production schedule
194
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16
14
12
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Note:
1. fuel oil price, $/bbl, as noted
2. costs @ January 1974
0
50
100 150 200
Capacity, units of 1,000 gpd
250
300
'igure 12, Rum distillery slops treatment by anaerobic contact process unit
treatment costs
195
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parameters such as VSS (volatile suspended solids) and COD (chemical
oxygen demand) are used as measures of viable biomass and limiting sub-
strate, respectively, and is a useful tool in engineering design
and analysis of full scale applications.
3. The operational relationship between effluent quality and the primary
variables 0t (hydraulic residence time) and C° (recycle factor) pro-
vide a unifying basis for examining the design problem and establishing
operating objectives in the application of the anaerobic contact process
for treatment of rum distillery slops.
4. The recovery of methane as an energy byproduct of rum distillery slops
treatment by the anaerobic treatment process can reduce the unit treatment
costs ($/unit volume treated) in a plant scale installation, at current
energy costs, by at least one third at a design capacity of 190 cu m/day
(50,000 gpd) and as much as two thirds at a design capacity of 1,140 cu
m/day (300,000 gpd).
ACKNOWLEDGEMENTS
This investigation was supported in part by Demonstration Grant S800935 from
the Industrial Pollution Control Division of the United States Environmental
Protection Agency. Mr. W. E. Paterson deserves special acknowledgement for
his contributions to the project. Drs. A. D. Carr, J. F. Andrews, and Paul
Smith served as project consultants. The assistance of John Stockton,
T. J. Smith, and Eric W. Jerome, and the counsel of Dr. W. E. Gates are
gratefully acknowledged, as is the participation and contributions of the
U.S. EPA personnel, Messrs. H. G. Keeler, and K. A. Dostal.
196
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NOMENCLATURE
K = a constant equivalent to the substrate concentration when k = km/2
K^ = specific autodestruction rate, time
k = specific growth rate, time~l
Y° = mass of organisms produced/mass of substrate removed, mg/mg
X° = concentration of organisms, mg/1
X° , X° , X° = influent; reactor effluent, and separator effluent organism
concentrations, mg/1, respectively
X^ = mass of organisms leaving system per unit time/total flow leaving
system per unit time, mg/1
XR° = recycle stream (and sludge wastage stream) organism concentration, mg/1
C° = recycle factor = X°/X-,°
w -1-
X = concentration of controlling substrate, mg/1
XN, X?, X^J = influent, reactor effluent, and separator effluent substrate
concentrations, mg/1, respectively
XR = recycle stream substrate concentration, mg/1
C" = degree of concentration of substrate in the solids separator
9 = time
9t = theoretical hydraulic detention time, time
Q = influent flow rate, I/day
Qs = sample flow rate, I/day (average)
Qw = sludge wastage flow rate, I/day
r = fraction of influent recycled
197
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REFERENCES
1. PETTET, A. E., TOMLINSON, T. G., and HEMENS, J. The treatment of strong
organic wastes by anaerobic digestion. J. Institution of Public Health
Engineers: 170 (1959).
2. HIATT, W. E., CARR, A. D., and ANDREWS, J. F. Anaerobic digestion of
rum distillery wastes. 28th Purdue Industrial Conference: (1973).
3. STANDER, G. J. and SNYDERS, R. J. Institute of Sewage Purification
IV: 447 (1950).
4. RADHAKRISHMAN, I., DE, S. B. and NATH, B. Evaluation of the loading
parameters for anaerobic digestion of cane molasses distillery waste.
J. Water Pollution Control Federation 41: R431 (1969).
5. BHASKARAN, T. R. Utilization of materials derived from treatment of
wastes from molasses distilleries. Advances in Water Pollution Research,
Pergamon Press, London, (1965).
6. JACKSON, C. J. J. Institute of Sewage Purification, Part III: 206 (1956).
7. MCCARTY, P. L. Discussion. J. Sanitary Eng. Div, Proc. American
Society of Civil Engineers 89: SA6, 65 (1963).
8. GATES, W. E., SMITH, J. H., LIN S., and RIS, C. H. A rational model
for the anaerobic contact process. J. Water Pollution Control Federation
39: 1951-70 (1967).
9. MONOD, J. The growth of bacterial cultures. Annual Rev. Microbiol. 3:
371 (1959).
10. Product Bulletin PC-627, Nalco Chemical Company, (1973).
11. SCHROEPFER, G. J. ET AL. The anaerobic contact process as applied to
packinghouse wastes. Sewage and Industrial Wastes 27: 4, 460 (1955).
12. SCHROEPFER, G. J., and ZIEMKE, N. R. Development of the anaerobic contact
process. I. Pilot Plant Investigations and Economics. Sewage and
Industrial Wastes 31: 2, 164 (1959).
13. ANDREWS, J. D. and PEARSON, E. A. Kinetics and characteristics of
volatile acid production in anaerobic fermentation processes. 55th
National Meeting American Institute of Chemical Engineers (1965).
14. STEFFEN, A. J., and BEDKER, M. Operation of full scale anaerobic
contact treatment plant for meat packing wastes. 16th Ind. Waste
Conference (1961).
15. BABBITT, H. E., and BAUMAN, E. R. Sewage and Sewage Treatment. John
Wiley and Sons, New York (1958).
16. SHEA, T. G. ET AL. Rum distillery slops treatment by anaerobic contact
process. USEPA Project S800935, (1974)
198
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GULF SHRIMP
CANNING PLANT WASTEWATER PROCESSING **
by
A. Frank Mauldin and A. J. Szabo *
INTRODUCTION
The canning of shrimp was first successfully done in 1867 by George W. Dunbar, an
enterprising New Englander who settled in New Orleans and operated a cannery
after the Civil War. From this difficult and trying beginning, an industry has deve-
loped which consists of approximately 70 shrimp canners in the United States, 25 of
which are located on the coast of the Gulf of Mexico. The Gulf Coast Canneries
are primarily in Louisiana and Mississippi on bays or bayous or within short trucking
distance of the docks. These canning plants have for many years been and most
remain family enterprises. The canneries compete for the available supplies of raw
shrimp and generally obtain and process the smaller sizes. Therefore, the economi-
cal operating period is generally during the short spring and fall seasons when shrimp
may be taken in the regulated coastal waters. Because of the controlled seasons,
the variables of supply and the market price, the competition for the raw shrimp is
great and no plant is assured that it will operate on a continuous schedule. Never-
theless, each plant which operates must be able to handle its perishable raw shrimp
supply in a short time. Therefore, plants have developed along the same, most
efficient mechanical operating basis. Most of the equipment is of the same or similar
manufacture and the wastes created by the operating units have very similar charac-
teristics.
Because of the high strength and relatively large volume of wastewater discharged
by shrimp canneries, a joint effort at developing an economical pollution control
technology through cooperative effort was aimed at accomplishing what many small
canners could not individually achieve. The Environmental Protection Agency
and the American Shrimp Canners Association, consisting of twenty-two member
plants sponsored this study for this purpose.
Domingue, Szabo & Associates, Inc., Consulting Engineers, Lafayette, Louisiana.
This study was supported by funds from the Environmental Protection Agency,
Office of Rest arch and Development, under Grant No. S 800 904 and the
American Shrimp Canners Association.
199
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SHRIMP PROCESSING AND CANNING
The operations in a shrimp cannery are basically the same the world over, as shown
in Figure 1 (1). Raw shrimp are first thoroughly washed and separated from debris
or trash and unsuitable materials. The raw shrimp are peeled and deveined with
mechanical devices developed especially for the shrimp industry. Heads and hulls
are removed, pieces of shell and legs are separated and the remaining tail meat is
separated from the waste.
Raw shrimp are mechanically peeled by Laitram Model A peelers. This machine re-
moves the head and shell by mechanical and hydraulic action. It basically consists
of inclined steel and rubber coated rollers which form a squeezing gap where the
head and shell is loosened and removed from the shrimp meat. Water is used pri-
marily to facilitate movement of the shrimp down the inclined rollers.
In the deveining operation the back of the shrimp is split by a unique razor edge device.
The shrimp with the exposed vein then drops into a rotating drum with inside "fingers"
which remove the vein. The veins are then washed out of the drum and are discharged
with the wastewater. The deveining operation is generally not used on all shrimp
processed but only on the larger sizes.
After deveining, the shrimp are pre-cooked or blanched for approximately 3 minutes
in a boiling brine solution which curls the meat, extracts moisture and solubles and
develops the pink or red color of the finished product. Blanching can either be a
batch process, where the blanching water is dumped several times daily, or conti-
nuous, where the shrimp are fed through the tank on a conveyor and brine water is
continuously added and washed from the tanks.
After cooling, drying, further inspection and grading, the shrimp are packed, on a
scaled weight basis, into the appropriate size can, then mechanically sealed and
retorted for 12 minutes at 250° F. After cooling, the cans are labeled and are
ready for shipment to market.
WASTEWATER CHARACTERISTICS
Table 1 shows BOD-5 and suspended solids characterization for the primary shrimp
processing and canning operations. The peeling operation contributes approximately
70 % of these parameters to the total discharge. The miscellaneous operations in-
clude water flume dumps, canning, retort cooling and inspection. The BOD-5 con-
centration for the total discharge varies from 1,000 mg/l to 1800 mg/l and the
suspended solids concentration for the total discharge varies from 400 mg/l to 800 mg/l.
200
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Figure I (I)
GENERAL PROCESS SCHEMATIC
SHRIMP CANNING
1
RECEIVING
WEIGHING
PEELING
1
CLEANING
SEPARATING
1
DEVEINING
1
PACKING
FISH , DEBRIS, WATER
HEADS , SHELLS , WATER
SHELL MATERIAL .WATER
SHRIMPMEAT.VEINS.WA
1
| INSPECTION
1
BLANCHING
|
GRADING
I
FINAL
INSPECTION
4
CANNING
i '
RETORTING
4
COOLING
DEBRIS, SHRIMPMEAT
SHRIMPMEAT, SALTWATER^
SHRIMPMEAT, DEBRIS
, P
SALTWATER
P
HOT WATER
WATER
*
1
PRODUCT FLOW
WASTE FLOW
201
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TREATMENT BY SCREENING
Several different screens were pilot tested during the study. The purpose of the
screening tests was to evaluate the efficiency and ease of operation of the tested
screens. Several of the larger canners had obtained experience in screening the
shells and the heads from their peeler wastewater with vibrating screens. These
screens operated satisfactorily but were expensive to purchase and maintain. It
was felt that ease of operation and economical maintenance should be a prime con-
sideration in evaluating the pilot screens.
The following screens were tested with raw peeler wastewaters:
1. Sweco "Vibro-Energy Separator".
2. HydrocycIonics "Rotostrainer".
3. Bauer "Hydrasieve".
4. Dorr Oliver "DSM".
5. Hydrocyclonics "Hydroscreen".
A description and evaluation of each of these screens follows:
Sweco "Vibro-Energy Separator" . This screen was 48" in diameter with a 20 mesh
(approximately 0.84 mm opening) screen fabric. This screen was circular, mounted
on coil springs, and wastewater enters from the top. The underflow passed through
the screen and the screened solids were vibrated with a spiral rolling motion to the
sides of the screen where they were discharged through two ports 180 degrees apart.
The vibrations were caused by an electric motor whose shaft was eccentrically loaded.
This screen was a permanent plant installation at the test cannery. Wastewater from
eight peeling machines and four separators was lifted by centrifugal pumps to the
screen. With eight peeling machines operating (the usual practice), the flow to the
screen was approximately 500 gpm.
This screen was effective in removing suspended solids, approaching 40%. The screen
was not the most effective for removing settleable solids; the removal was less than
60% leaving a mean settleable solids residual of approximately 20 ml/1 in the under-
flow. BOD-5 and total solids removal appear to average at around 15% reduction.
The screened solids were fairly dry with an average value of 84% moisture.
Hydrocyclonics "Rotostrainer" . This screen had a diameter of 25 inches and a length
of 24 inches. The pilot unit had a screen opening of 0.5 mm (32 mesh equivalent).
The cylindrical screen had the appearance of a water well screen with a wedge wire
grid. The unit was equipped with a weir influent box for even influent distribution
to the screen. The water passed through the screen openings on the top of the
screen, fell through the center of the cylinder and passed through the screen openings
again on the bottom, thus backwashing any solids trapped in the screen. The solids
203
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were carried on the top surface of the screen to a scraper bar where the solids were
removed.
The removal of suspended and settleable solids was somewhat less for this screen than
for the vibrating screen even though the screen opening for the rotating screen
(0.5 mm) was less than for the vibrating screen (0.84 mm). The screenings, at 22%
dry solids were fairly dry.
Bauer "Hydrasieve" . This pilot tangential screen was 18 inches wide and 33.5 inches
high. The test screen was supplied with four different screen openings: 0.020 inches
(32 mesh), 0.030 inches (22 mesh), 0.040 inches (16 mesh) and 0.060 inches (11
mesh).
This screen had a headbox and a weir for even influent distribution and for feeding
the wastewater onto the screen tangentially. The screen bars were wedgewire and
ran transverse across the screen. The wedgewire bars curved downward between the
vertical supports to cause the flow to divide into separate streams between the
vertical supports. The manufacturer claims this helps prevent clogging and blinding.
This screen was tested as a primary screen on raw peeler wastewater. All the screen
openings available were tested at 50gpm. The evaluation was limited, however,
because only one short run was made with each screen opening. These results indi-
cate that the 0.020 inch opening screen produced the best results. This size tended
to bl ind fairly quickly with a slime build-up. This unit with a 0. 030 inch (0.75 mm)
opening screen performed excellently during the short test run. Residual settleable
solids in the under-flow was only 14 ml/1. The other screen openings (1.0 mm and
0.5 mm) also performed without blinding problems but solids removal was inferior to
the 0.75 mm opening screen. The screened solids were extremely wet upon leaving
the screen but tended to gravity drain very quickly. The screenings were 92% mois-
ture at the point of leaving the screen. This was due probably to a noticeable
amount of water continuously trickling from the end of the screen. The test unit
had been used at many locations and the seals between the sides of the wedge wire
screen and frame were worn causing water to channel down the inside walls. This
was probably the major cause of the wetness of the screenings solids.
Dorr-Oliver "DSM". This pilot tangential screen was 12 inches wide and approxi-
mately 6 feet tall. Test runs with screen openings of 0.020 inch, 0.030 inch and
0. 040 inch were made. The velocity across the face of the screen was very fast.
As a consequence, a slight blinding of the 0.020 inch screen caused a complete
failure with water discharged over the end of the screen. With the 0.030 inch
opening screen, residual settleable solids of only 13 ml/1 in the underflow was
found. The 0.040 inch opening had residual settleable solids of 18 ml/1. No indi-
cation of blinding was observed with these two screens. The screened material had
approximately 82% moisture when leaving the screen.
204
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Hydrocyclonics "Hydroscreen". This pilot tangential screen was also tested with raw
peeler wastewater. This screen was similar in design to the Bauer screen. Several
differences included: the screening surface was actually three separate screens,
all at slightly different angles to the vertical; the influent weir did not direct the
water tangentially to the screen but was actually a small jump; and the screening
surface of the test unit was about one foot longer than the Bauer screen. This screen
unit was apparently new and was in excellent condition.
The differences in the screen design were apparently significant. The residual
settleable solids in the underflow was 22 ml/I. This was considerably higher than
the Bauer screen. However, screenings contained approximately 18% dry solids
when leaving the screen. This was due to the solids staying on the screen much
longer, and no noticeable amount of water was discharged from the end of the screen.
Only one test run was made with this screen, using a 0. 020 inch screen opening and
a flow of 50gpm. No blinding problems were observed during the test run.
Figures 2 and 3 show a comparison of effluent and screenings quality with the above
screens tested on raw peeler wastewater.
On screening peeling wastewaters, the investigators evaluations
are:
Of the three types of screens, the tangential screens produced the best and
the poorest effluent as evaluated by residual settleable solids concentration
in the effluent. The rotating screen produced the driest screenings and the
vibrating screen performed midway to the other two types for both criteria.
The tangential screens consumed no power, therefore, were best for this
category. The vibrating screen was the poorest and the rotating screen was
only slightly more power demanding than the tangential screens, because it
was physically lower than the tangential screens and the pumping head
required was lower.
In ease of operation, the rotating screen was best. During a short evaluation
it showed no tendency to blind or clog. The vibrating screen required a
frequent water hosing and was midway in this category. The tangential
screens required frequent hosing and periodic brushing with a steel brush.
In anticipated operating cost, the rotating screen may be the best because
maintenance should be minimal. The tangential screen would likewise
rate high if equipped to provide maintenance from blinding in lieu of man
power. The vibrating screen because of its mechanical nature is last be-
cause of expected high maintenance costs and the need for operating
manpower.
205
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LJ
UJ
or
u
LJ
or
o
PILOT SCREEN EVALUATION
WITH
PEELER WASTEWATER
Figure 2
Hydrocyclonics
Rotostromer
Hydrocyclonics
Hydroscreen
Dorr- Oliver
DSM
Sweco
Vibro- Energy
Bauer
Hydrasieve
75
80
85
90
SCREENINGS MOISTURE (%)
Figure 3
Bauer
Hydrasieve
Dorr-Oliver
DSM
Hydrocyclonics
Rotostramer
Sweco
Vibro- Energy
Hydrocyclonics
Hydroscreen
10
15
20
EFFLUENT SETTLEABLE SOLIDS ml/1
206
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TREATMENT BY DISSOLVED AIR FLOTATION (DAF)
The DAF pilot plant evaluation was made during the fall, 1972 and the summer,
1973 canning seasons. Objectives were to intensely evaluate the operational
variables of the DAF process while treating shrimp canning wastewaters. The ultimate
objective of the pilot plant studies was to develop design criteria for full scale plant
design.
The purpose of any DAF treatment system is to separate and concentrate suspended
and colloidal particles in the feed wastewater. Larger particles of the settleable
solids size should be removed prior to DAF treatment by screens and cyclones if
high density particles are present. Separation of small suspended and colloidal
solids depends more on their structure and surface properties than on their size and
density. Therefore, DAF treatment plants can not be designed theoretically or
rationally by mathematical equations, but must be planned by the use of laboratory
(bench scale) and pilot scale studies. Factors of greatest importance in designing
DAF plants are as follows (2):
1. Pressurization Piping (Full flow or recycle).
2. Chemical Optimization.
3. Air/solids Ratio.
4. Cell solids loading.
5. Sludge Concentration.
The selection of a pressurization piping mode for the pilot plant unit was one of the
first major decision points that the investigators faced. Schematics of full flow
pressurization DAF and recycle pressurization DAF are shown in Figures 4 and 5,
respectively (3). The full flow pressurization system is a single pass system. The
recycle is only for protection of the process pump during periods of low influent flow.
The recycle pressurization system pressurizes only a recycle stream. The raw influent
is fed to the flotation cell by gravity.
The full flow pressurization system offered the very large advantage of lower capital
costs. The major disadvantage to this system, technically, was that any flocculation
prior to pressurization would be sheared in the pressurization pump. All flocculation
would then have to occur in a short period within the flotation cell and could result
in immature floe and poor separation. If this occurred, then this type of system
would not be suitable for treating shrimp canning wastewaters.
The recycle pressurization system had the reported disadvantage of high capital
costs. Its advantage was that a floe could be preformed in a separate flocculation
tank and be fed to the air flotation cell by gravity, thus preserving the fully matured
floe. This would facilitate good separation of the floe from the remaining water.
207
-------
Figure 4
FULL FLOW PRESSURIZATION
DISSOLVED AIR FLOTATION
Recycle
Effluent
Figure 5
RECYCLE PRESSURIZATION
DISSOLVED AIR FLOTATION
Influent
Effluent
Retention
Tank
208
-------
Preliminary jar resting was performed at the study plant during the summer of 1972. A
coagulant system consisting of pH adjustment, alum and anionic polymer was found
to give an extremely tough, stable floe. The decision was then made to pilot test a
total pressurization system for the first season and, if results were unacceptable,
to then change to a recycle pressurization system.
A total pressurization DAF pilot system, shown in Figure 6, manufactured by the
Carborundum Company was tested during the Fall, 1972 canning season. There was
considerable lost time during this season because of mechanical problems, the investi-
gators inexperience with the pilot test equipment and short canning runs. However,
the test unit did show good potential, because when the proper controls could be
maintained, very efficient treatment resulted. Because of the potential this unit
demonstrated, it was decided to pilot test the unit a second season.
Bench scale jar tests and pressure bomb tests (2) were performed in the summer of
1972. Acid titration tests showed the protein isoelectric point to be about pH 4.5.
The raw wastewater had a pH of about 6.9, therefore, pH adjustment was necessary
for protein precipitation. Many combinations of coagulants, polymers and water
conditioners were tried in the jar tests, but the best combination found was as follows:
Coagulant: Aluminum sulfate - 75 mg/l
Polymer: Magnifloc 835 A - 2 mg/l
pH: 5.2 ± 0.2.
These chemicals and dosages were confirmed with the pilot unit to be optimum.
Floe carryover was a minor problem with the DAF unit during the testing period. There
was no observable relationship between effluent COD and minor degrees of floe carry-
over. The minor floe carryover was probably an after-floe formed by inorganic non-
COD demanding solids. The processing water used by the plant was high in chlorides
(1000 mg/l). A major floe carryover problem was observed when runs were made with
polymer dosages of less than 2.0 mg/l. This was in contradiction to the jar tests
where good separations were made with lower polymer dosages. This probably demon-
strates the economic trade off necessary when using a full pressurization system;
capital costs will be lower but operating costs will probably be somewhat higher.
Several preliminary runs or parts of runs were made using no chemicals or pH ad-
justment but using air flotation only. The effluent was not tested because there was
no observable treatment. The effluent appeared to be of exactly the same quality
as the influent and the floated sludge was extremely light and bubbly. Very few
captured solids were observed in this type of sludge. Flotation bomb bench scale
tests were made with no chemicals but with full air. Virtually no reduction in TOC
resulted. Runs were made with the DAF pilot plant with inefficient coagulant systems
and virtually no removals of COD, turbidity or suspended solids occurred. These facts
209
-------
Figure 6
DISSOLVED AIR FLOTATION
PILOT PLANT SCHEMATIC
SCREENED
TANGENTIAL
SCREEN
bULIDS
SCREEN
INFLUENT
^
PILOT
PLANT
INFLUENT
ACID
SCREEN
TANK
COAGULANT
PRESSURIZATION
TANK
PRESSURE
RELEASE
VALVE
POLYMER
SLUDGE
COLLECTION
TANK
o
SLUDGE
BASKET CENTRIFUGE
SLUDGE OEWATERING
RAW CANNERY WASTEWATER
AFTER SCREENING THROUGH
20 MESH VIBRATING SCREEN
210
-------
made it very clear to the investigators that an efficient coagulant system must be used
if significant pollutant reductions are to be achieved.
Table 2 shows the average operating conditions for the pilot DAF testing and Table 3
shows the pollutant removal efficiencies for this testing. BOD-5 removals averaged
65% but had a range of 80 % to 50 % with suspended solids removal being about
the same. The effluent during good runs was almost crystal clear with a turbidity of
less than 20 units. The small amount of floe carryover that persisted caused this
small amount of turbidity. The effluent was visually clear between floe particles.
The effluent BOD~5 for good runs was below 400 mg/l, the effluent COD was below
1200 mg/l, the effluent suspended solids was below 100 mg/l and the effluent protein
was below 600 mg/l. This range of results has generally been confirmed by Petersen
(4) and Claggett (5 and 6) with shrimp and salmon wastes, respectively.
Three runs were made for the purpose of optimizing the cell solids loading rate. All
of the runs were performed with optimum chemical dosages developed previously.
Three runs were completed with influent flow rates of 25 gpm, 50 gpm and 75 gpm.
The influent suspended solids concentration for each run was slightly different;
therefore, flow and solids loading were not directly proportional. The results are
shown in Figure 7.
From Figuas 7 it appears that optimum cell solids loading was approximately 0.25
Ibs/hr./ft and for the particular pilot unit tested, the optimum influent flow was
approximately 40 gpm.
Several values of air/solids ratios were computed from similar runs made during the
testing program. The results of these computations are shown in Figure 8 where A S
ratios are plotted against removal of suspended solids. From Figure 8 it appears
optimum A/S ratios are within the range of 0. 10 and 0. 15.
The concentration and flow rate of the flotation sludge was measured for most of the
pilot runs. Mean results are shown in Table 4.
SLUDGE DEWATERING BY CENTRIFUGATION
The flotation sludge skimmed from the top of the DAF pilot plant was concentrated
in a basket type pilot centrifuge manufactured by De Laval. The centrifuge had the
following characteristics:
Method of Feed: Batch
Feed Volume: 2. 5 gallons
Basket Type: Solid
Material Removal Method: Skimmer
211
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TABLE 2
DAF PILOT PLANT
AVERAGE OPERATING CONDITIONS
Flow:
Pressurization:
Air/Solids
Cell Solids Loading:
Acid Addition:
Alum Addition:
Polymer Addition:
50 gpm
40 psig
0.14
0.33 IbsAr/ft2
Surge Tank
Screen Tank
Flotation Cell Influent
TABLE 3
DAF PILOT PLANT EVALUATION
Pollutant Removal Efficiencies
Parameter
BOD-5
COD
Total Solids
Suspended Solids
Protein
Turbidity
Ortho Phosphate
Total Organic Carbon
Mean
Removal
%
65.1
59.0
14.9
65.6
52.5
83.0
27.5
61.4
Maximum
Removal
%
80.0
69.5
42.9
85.8
91.1
97.5
38.2
62.8
Minimum
Removal
%
50.0
43.5
0.0
7.0
25.7
61.9
15.4
60.0
212
-------
v>
JO
o
Q
g
CO
Q
_l
O
CO
LJ
O
Figure 7
PILOT DAF PLANT EVALUATION
SOLIDS LOADING VS. TURBIDITY REMOVAL
0.7CH
0.60-
0.50-
0.40-
0.30-
0.20-
0.10-
75
.Influent Flow
75 gpm
Influent Flow,
25 gpm
I
80
I
85
I
90
I
95
100
TURBIDITY (% REMOVAL)
213
-------
Figure 8
PILOT DAF PLANT EVALUATION
A/S RATIO VS. SUSPENDED SOLIDS REMOVAL
0.25-1
0.20-
0.15-
0.10-
0.05-
0.00-
50
i
60
70
80
90
SUSPENDED SOLIDS (% REMOVAL)
214
-------
TABLE 4
DAF PILOT PLANT EVALUATION
Flotation Sludge Characteristics
Parameter
Dry Solids
Flow
Protein
Units
%
gpm
mg/l
Mean
2.98
4.28
15,819
Maximum
4.02
5.97
26,318
Minimum
1.58
1.17
6,963
TABLE 5
PILOT CENTRIFUGE EVALUATION
Mean Results
Parameter
Feed Sludge
Centrifuge Cake
Centrate
Air
Mean
% Dry Solids
3.36
6.23
1.05
0.0
Mean
Volume
(gallons)
2.50
0.58
0.98
0.94
215
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Average results obtained are shown in Table 5.
TREATMENT ECONOMICS
The total costs of wastewater treatment for seafood processors are difficult to present
in general. Total costs involve the characteristics of the wastewater, plant piping,
capital costs of equipment, operation and maintenance costs, administrative costs,
engineering costs and the salaries of operating personnel. These costs can vary
widely from plant to plant.
A cost of a waste treatment system for a hypothetical 8 peeler shrimp processing
plant is presented here. The assumed wastewater flow is 600 gpm. Screenings and
dewatered sludge are assumed hauled to a land fill.(The alternative to hauling would
be a reduction plant where screenings and sludge would be dried and sold as by product
waste meal. Because the capital and operating costs of a reduction plant are large
and the market conditions for waste meal are very uncertain (7), this alternative has
not been considered).
The treatment system consists of screening, dissolved air flotation, chemical addition
system, sludge dewatering,centrifuge sludge and screenings holding tank, tank truck
and all necessary pumps and conveyers. The operation and maintenance costs/day
assume eight hours of processing and include chemical costs, power costs, a plant
operator, a truck driver and a land fill fee.
The installed capital costs for the above described treatment system, the operation and
maintenance costs/day and the amortized cost /day (assumed 10 year life, 7% cost
of money and 120 days operation/year) are as follows:
Capital Costs - $210, 000. 00
Operation and Maintenance
Costs $ 155.00/day
Amortized Costs $ 280. 00/day
216
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REFERENCES
]. Soderquist, M. R., Canned and Preserved Fish and Seafoods Processing
Industry Development Document for Effluent Limitations Guidelines and
Standards of Performance, EPA. Contract No. 68-01-1526, July, 1973.
2. Eckenfelder, W. W., Jr., Industrial Water Pollution Control, McGraw-
Hill, 1966.
3. Snider, Irvin, Carborundum Company, Knoxville, Tennessee, (Personal
Communication).
4. Peterson, P. L., Treatment of Shellfish Processing Water by Screening and
Air Flotation, (unpublished), National Marine Fisheries Services, Kodiak,
Alaska, 1972.
5. Claggett, F. G., and Wong, J., Salmon Canning Wastewater Clarification,
Part II. Fisheries Research Board of Canada, Vancouver Laboratory, British
Columbia, February, 1969.
6. Claggett, F. G., and Wong, J., Salmon Canning Wastewater Clarification,
Part I. Fisheries Research Board of Canada, Vancouver Laboratory, British
Columbia, January, 1968.
7. Mendenhall, V., Utilization and Disposal of Crab and Shrimp Wastes,
University of Alaska, Marine Advisory Bulletin No. 2. NTIS, COM-
71-01092, March, 1971.
217
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WASTEWATER CHARACTERIZATION FOR
THE SPECIALTY FOOD INDUSTRY
by
Curtis J. Schmidt*, Ernest V. Clements III*, and
John Farquhar**
INTRODUCTION
Specialty foods, as used in this project, includes frozen
and canned items containing several major ingredients.
Included are such varied products as frozen dinners, frozen
and canned pre-cooked fish, beef, and poultry dishes, fro-
zen and canned stews and soups, frozen or canned ethnic/
nationality foods, frozen vegetables in sauce, frozen
bakery products and other prepared and/or pre-cooked foods.
Specialty food firms generally fall within SIC Codes 2032,
2035 and 2037.
The magnitude of this segment of the food industry is made
obvious by a stroll through any supermarket: more shelf
and freezer space is taken by specialty foods than by ordi-
nary canned and frozen fruit and vegetable items. Exact
production data on a national scale is lacking. However,
combined statistical sources estimate that specialty foods
production exceeds other types of food production.
The estimated number of specialty food plants is approxi-
mately 2,300 with the largest number in the states of Cali-
fornia, New York, Illinois and Pennsylvania. Meat special-
ties has the largest number of individual plants among the
categories.
During the second half of 1973 the American Frozen Food
Institute (AFFI) conducted a study to characterize waste-
water generation by the specialty food industry. AFFI was
aided by the National Canners Association (NCA), which
*SCS Engineers, Long Beach, California and Reston,
Virginia
**The American Frozen Food Institute, Washington, D.C.
***This investigation was supported by funds from the
Environmental Protection Agency, Office of Research and
Development, under Grant No. R-801684, and by the
American Frozen Food Institute, Washington, D.C.
218
-------
performed all laboratory analyses, and SCS Engineers (SCS),
which performed all field work and prepared the final re-
port. Financial assistance was provided by the Environmen-
tal Protection Agency (EPA) under Grant No. R-801684.
The major objectives of the project were to:
Inventory and categorize the specialty foods
industry.
Investigate typical raw waste loads generated by
major categories of the specialty foods industry.
This information is needed by AFFI, NCA and EPA to increase
their background knowledge in answering questions concerning
waste generated by the specialty food industry and to regu-
late industry waste generation in an equitable manner.
FIELD INVESTIGATIONS
A preliminary assessment of the types, number and locations
of specialty food plants was prepared, and a tentative de-
termination made of representative plants in the west, mid-
west, and east which appeared to be desirable candidates
for field investigation. Each candidate plant was contacted
by phone and letter, given a description of the project,
and requested to indicate a preliminary assurance of coop-
eration. A series of meetings were arranged by AFFI in San
Francisco, Chicago, and Washington, B.C. at which the pro-
ject technical team met with company representatives to
work out details of individual plant investigations. Every
attempt was made to insure that the participating industry
plants were cognizant of their responsibilities to the
project. The final selection of participating plants was
made to provide diversity in type of product and geographi-
cal area. The plants were located as follows:
East 6 plants
Midwest - 9 plants
West 11 plants
During the field investigations, the procedure followed at
each plant was generally similar. Once plants in the same
geographic region had agreed to participate, the project
technical director visited each plant to review the plant
layout; determine a proper location for installation of a
composite sampler; initially educate plant personnel in
their responsibilities to extract and store samples; advise
the necessity for obtaining concurrent information on pro-
duction and wate volume; observe waste treatment facilities,
and agree upon a date to begin waste sampling. On the
219
-------
agreed date, the field engineer installed the automatic
sampling unit at a site pre-selected by the project direc-
tor and plant staff. The sampling sites were located to
obtain representative samples of screened raw waste prior
to pretreatment units. Areas of turbulence were chosen to
insure mixing and suspension of solids. Once the engineer
had installed the sampler, he instructed the plant person-
nel in proper sampler operation and sample handling. In
most cases this involved merely turning the unit on and off
at the beginning and end of shifts, filling a sample bottle
from the large 2-1/2 gallon sample collection container,
after swirling the latter to achieve a homogeneous waste-
water solution, and placing the sample in the Coleman
cooler in the plant freezer. The engineer also advised
plant managers as to what supplemental data would be needed
on production tonnages and wastewater volumes and urged
them to compile this information during the sampling period.
During the sampling period, the investigator returned to
the plant every 3 or 4 days to insure proper operation and
to pick up frozen samples. These samples were packed in
dry ice in the styrofoam lined boxes and transported by the
quickest means to the NCA Laboratory in Berkeley, Cali-
fornia. Most of the samples were shipped air freight to
San Francisco for pickup by the laboratory. Samples col-
lected from plants in northern California were delivered by
car to the laboratory the same day.
At the end of the sampling period, the engineer picked up
the last of the frozen samples, shipped them to the lab,
and acquired whatever volume and production data was avail-
able at that time.
Sampling frequency, type, and procedures were somewhat de-
pendent upon circumstances found at each plant. Approxi-
mately ten "end of pipe" time interval composite samples for
ten consecutive operating days were collected at each plant.
These samples were generally 24 hour composites, but excep-
tions were made due to plant operation or collection time
requirements. If distinct "processing" and "clean-up"
shifts existed, samples of each shift were taken along with
related wastewater volume data. At two of the plants addi-
tional grab samples were taken of major waste streams (i.e.,
sauce room clean-up). Some food plants investigated had
their own permanent automatic sampler. In these situations,
the field engineer supplied the sample bottles, and storage
cooler. Plant personnel took their routine composite sam-
ples and divided the sample for use by this study, and for
their own analysis work.
220
-------
ANALYSIS
Field determination was made of pH, temperature, volume
(existing records and metering devices) and any unusual
visual characteristics of the waste. Laboratory analysis
included chemical oxygen demand (COD), 5-day biochemical
oxygen demand (BOD), suspended solids (SS), volatile sus-
pended solids (VSS), total kjeldahl nitrogen (TKN) as mg/1
N, total phosphorus (TP), and oil and grease.
When shipments of samples arrived at the NCA lab, they were
kept frozen until lab analysis was to begin. Samples were
analyzed for the following constituents using the standard
procedures listed below:
Test Procedure
COD Standard methods (13th edition)
BOD Standard methods: 5-day, 20°C,
cylinder dilution procedure.
SS Standard methods using glass
fiber filter paper.
VSS Standard methods.
Total P From Methods for Chemical Analy-
sis of Waste and Water, EPA,
1971, 16020 — 07/71.
TKN Standard methods.
Grease and oil From Methods for Chemical Analy-
sis of Waste and Water, EPA, 1971,
16020 ~ 07/71.
Two of the 26 plants studied were not sampled, but provided
comprehensive historical information on wastewater concen-
trations, volumes, and production weights. Productivity
factors were calculated from this data just as it was for
the other plants.
APPROACH TO CATEGORIZATION
Categorization of the specialty foods industry is made com-
plex by the great number of plants and wide diversity of
products. In addition, many plants make several products
and it is virtually impossible to relate wastewater char-
acteristics back to a certain product because a variety of
products are processed simultaneously and the mix is often
221
-------
continually changing. Another hindrance to categorization
is the fact that although two plants may produce virtually
the same final products, one may employ more intensive raw
material processing than the other, and thus their waste-
water properties could vary significantly. Moisture con-
tent of products can vary between product styles, affecting
productivity factors based on final product weight.
Other factors which may have a significant effect upon
wastewater generation from a particular plant include, plant
size, number of shifts, percentage of production capacity
in use, cost of water supply and wastewater disposal, de-
gree to which ingredients have been pre-processed elsewhere,
managements desire to reduce waste generation, and economic
ability of the plant to modernize equipment.
Each of the factors described above may have an important
effect upon waste generation from a particular plant. This
study obtained data from an average of less than three
plants per category. Considering the many uncontrollable
variables involved and the limited number of plants inves-
tigated, the category selections and wastewater characteris-
tics presented in this report should be considered as pre-
liminary.
In order to obtain the most equitable categorization, with-
in the bounds of the scope of work, we based our decisions
for plant groupings on three basic factors:
Primarily: Type of product.
Secondarily: a) Type and degree of raw material
processing, b) wastewater productivity factors (kg
pollutant/kkg product).
The advantages of this approach to industrial categoriza-
tion are as follows:
Simplicity and ease of initial categorization -
rough grouping by "type of final product" is a com-
paratively simple task and provides a point of
departure for more detailed analysis. After
"product" grouping, processing differences or
wastewater characteristics can be reviewed to fur-
ther substantiate categorial selections or to re-
classify the plants that appear misplaced.
Provides easy comparison to other plants - grouping
by product allows members of the specialty food
industry to compare their overall plant wastewater
222
-------
characteristics to similar plants preparing the same
same products.
Good probability of similarity in other parameters-
plants initially grouped by product type frequently
show good correlation in overall wastewater proper-
ties (concentrations, volume per unit product,
etc.) if similar raw ingredient processing opera-
tions are performed.
In full recognition of the difficulties involved in cate-
gorizing a complex industry of over 2,000 plants, the fol-
lowing ten categories were established for the purpose of
this investigation.
1. Prepared dinners
2. Frozen bakery products
3. Dressings, sauces and spreads
4. Meat specialties
5. Canned soups and baby foods
6. Tomato-cheese-starch combinations (Italian
specialties)
7. Sauced vegetables
8. Sweet syrups, jams and jellies
9. Chinese and Mexican foods
10. Breaded frozen products
On the following pages we discuss the results of the field
analyses performed at plants in each of the above cate-
gories. Note that in many of the categories only one or
two plants were investigated. Table 1 on the following
page summarizes the average values for BOD, SS and volume.
223
-------
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224
-------
Category 1 - Prepared Dinners
Plant letter codes included in this category are A, B, C, D,
E, and F. The major products of this category are frozen
prepared dinners and pot pies including meat, poultry or
fish, vegetable, and starch (potato, rice, noodles). Plant
A produces significant frozen bakery products and Plant E
significant vegetable dishes in addition to prepared din-
ners.
The plants in this category do very little processing of
raw materials. The meat portions have been slaughtered and
dressed elsewhere, and the vegetables have also generally
been pre-processed elsewhere and shipped frozen in bulk.
The ingredients are usually cut into meal size portions,
cooked, assembled and frozen. Figure 1 on the following
page illustrates in a simplified flow diagram the "assembly
plant" nature of plants in this category.
The primary wastewater generating activity is plant clean-
up, which is generally concentrated during a late night or
early morning "clean-up" shift. However, cleaning of equip-
ment is carried out continuously as the product mix changes
or spills occur. Other wastewater sources may include,
vegetable rinsing and blanching operations, frying, cooking,
and cooling water.
This category was the most thoroughly covered of the ten
categories with six plants investigated. The plants are
usually very large, and are often located in small towns or
in rural areas where their wastes may constitute a signifi-
cant potential treatment problem.
Tables 2 and 3 show the waste generation and waste strength
of the effluents from plants in this category. BOD genera-
tion ranges from 9 to 34 kilograms per 1,000 kilograms
(kg/kkg) or 18 to 68 Ibs/ton of production. Waste strength
varies from 600 to 4,000 milligrams per liter (mg/1) of
BOD. We believe that the highest levels represent plants
which (1) produce a higher proportion of rich foods and/or
(2) have not instituted a rigid in-plant program to avoid
excessive disposal of food materials into the sewer. Plant
E, for example, claims to have greatly reduced its waste
generation through a comprehensive program of personnel edu-
cation and in-plant modifications.
225
-------
PREPARATION
ASSEMBLY
FOWL
TURKEY -J
(processed elsewhere!
end frozen)
CHICKEN H
(processed elsewhere '
and frozen)
; CUTTING J
COOKING J
[COOKINGJ
JCUT |—
-~\ BONING | — — ^COOKING]—
-—{ BONING j .— { SLICING J- —
— — j BONING j — • — \ SLICING J- —
-— | FUOURED | — | FRYING I—-
NOTE
HEAVY ARROW
DESIGNATES MAJOR
LIQUID WASTE
GENERATION
MEAT
MEATLDAF
VEAL
(potties prepared
elsewhere)
BEEF
(prepared elsewhere
and rolled)
BROILING
[SLICEDJ-
GRAVIES
(meat juica from _
cooking)
VEGETABLES.
(processed elsewhere
ond frozen) ~~
POTATOES
(processed elsewhere) -
MEXICAN
flour
\
milk
-»-| CLUSTER BREAKUPJ-
DRIED BEANS -«-j WASHING -*-JGOOKING |——| MASHING
CORN
(dehusked decobbed
elsewhere)
RICE
GRINDING
CUTTING
INTO
TORTILLA
-{COMBINED^
prepared cheese—{SAUCINGJ-
prepared beef-
COOKING
PLANT CLEAN-UP
COMBINING^ COOKING
olives
cheese
COMBINED)
^ FROZEN^
FIGURE 1
PREPARED DINNER PLANT
SIMPLIFIED PROCESS FLOW DIAGRAM
226
-------
Table 2. CATEGORY 1, AVERAGE POLLUTANTS
CONTAINED IN WASTEWATER PER UNIT
OF PRODUCTION
Plant
code
Constituent (kg/kkg finished
COD
A 69.%
B 4aJ'
C 28$
D 27'Vt
E %20 4.
F 17
Average 34^
Range IT^Sr
; 69
BOD
35
18
13
15
11
8.8
17
9-
34
SS
34
11
11
14
6.6
6.2
14
6-
34
VSS
33
11
11
14
6.0
6.2
14
6-
33
Total
P
0.25
0.18
0.24
0.16
—
0.12
0.19 -
.12-
.25
TKN
0.44
0.25
0.61
0.55
—
0.37
0.44
.25-
.61
product)
Grease
and oil
44
21
-
2.9
3.8
4.8
15
2.9-
44
Volume
(1/kkg)
8,700
6,200
22,000
21,000
9,400
4,400
12,000
4,400-
22,000
Table 3. CATEGORY 1, AVERAGE
WASTEWATER CHARACTERISTICS
Plant
code
Concentration
COD
A 7,900
B 6,800
C 1,300
D 1,300
E 2,100
F 3,800
Average 3,900
Range 1,300-
7,900
BOD
4,000
2,900
620
720
1,240
2,000
1,900
620-
4,000
SS
3,900
1,800
530
680
700
1,400
1,500
530-
3,900
VSS
3,800
1,700
510
650
640
1,400
1,500
510-
3,800
(mg/1)
Total
P
29
30
11
7.6
-
28
21
7.6-
30
TKN
51
34
28
26
-
85
45
26-
85
Grease
and oil
5,100
3,400
-
140
400
1,100
2,000
140-
5,100
227
-------
Category 2 - Frozen Bakery Products
Plant letter codes included in this category are G and H.
The major products of this category are frozen bakery des-
sert products such as cakes, pies, brownies, cookies, rolls,
and other desserts.
The plants are very large scale kitchens which purchase the
ingredients such as butter, flour, shortening, eggs, sugar,
flavoring, fruit filling, etc., in much the same way as the
housewife would were she making the baked goods from
scratch. Plants G and H are both major producers of these
products with national distribution.
Tables 4 and 5 summarize the waste generation and waste
strength of the effluents from the two bakery products
plants. Waste strength is very high with BOD in the range
of 2,100 to 4,300 mg/1. Unfortunately, Plant H would not
provide production information, making it impossible to de-
termine the average pollutants per unit of production for
this plant.
Table 4. CATEGORY 2, AVERAGE POLLUTANTS
CONTAINED IN WASTEWATER PER UNIT
OF PRODUCTION
Plant
code
Constituent (kg/kkg finished product)
COD
BOD
SS
VSS
Total
P
TKN
Grease
and oil
Volume
(1/kkg)
G 52 23 14 14 0.082 0.30 11 11,000
H No Production Information Provided
Waste is generated from clean-up of spills and equipment
and from the disposal of substandard ingredients and prod-
ucts. The major ingredients are very rich and high in BOD,
suspended solids, and grease. Variations in frequency of
product mix changes and house cleaning practices help to
account for differences in effluent concentrations.
228
-------
Table 5. CATEGORY 2, AVERAGE
WASTEWATER CHARACTERISTICS
Plant
code
Concentration (mg/1)
COD
BOD
SS
VSS
Total
P
TKN
Grease
and oil
G 4,600 2,100 1,300 1,200 7.8 27 940
H 9,300 4,300 3,100 3,000 5,7 45 690
Average 7,000 3,200 2,200 2,100 6.8 36 820
Category 3 - Dressing, Sauces, and Spreads
Plant codes I and J are included in this category. Major
products are salad dressings, mayonnaise, mustard and barbe-
cue sauces. Typical ingredients include tomato paste, vege-
table oil, spices, eggs, vinegar, mustard, and small quanti-
ties of dairy products. Generally, the ingredients are
blended, bottled, cooked, and cooled. Clean-up of the
blending and cooking vats contributes most of the waste load.
The two plants sampled were a very small batch type plant
(J) and one of the nation's largest plants (I). As seen
from Tables 6 and 7 correlation was surprisingly good be-
tween the plants. Both exhibited very strong wastes with
average BOD of 2,700 mg/1, however, waste generation in
terms of production averaged a low 8 kg/kkg (16 Ib/ton) of
product. Wastewater volume averaged only 2,800 1/kkg (680
gal/ton) of product.
Table 6. CATEGORY 3, AVERAGE POLLUTANTS
CONTAINED IN WASTEWATER PER UNIT
OF PRODUCTION
Plant
code
Constituent (kg/kkg finished product)
COD BOD
I 12 5.6
J 14 9.4
SS
2.6
4.4
VSS
2.4
4.4
Total
P
0.039
0.018
TKN
0.036
0.038
Grease
and oil
3.1
8.3
Volume
(1/kkg)
2,600
3,100
Average 13 7.5 3.5 3.4 0.028 0.037
5.7
2,800
229
-------
Table 7. CATEGORY 3, AVERAGE
WASTEWATER CHARACTERISTICS
Plant
code
Concentration (mg/1)
COD
BOD
SS
VSS
Total
P
TKN
Grease
and oil
I 4,900 2,300 1,000 960 16 15 1,300
J 4,500 3,000 1,400 1,400 5.8 12 2,700
Average 4,700 2,600 1,200 1,200 11 14 2,000
The overall low productivity factors for this category are
due to the fact that equipment clean-up is the primary
wastewater producing activity, and relatively small volumes
of water are used. One misleading factor in the low prod-
uctivity and wastewater generation factors is that water is
a major weight component in the final product and most of
the initial ingredients. This tends to make the production
tonnages artificially high compared to other categories pre-
paring low water content products. Final productivity fac-
tors would be substantially higher for this category if
only product dry weight was considered.
Plant I has installed an automatic flow-proportional com-
posite sampler with refrigerated storage. Samples are taken
daily and analyzed for BOD and SS in the plant quality con-
trol laboratory. Plant management uses raw waste strength
as a gauge of their in-plant efficiency in minimizing waste
of valuable ingredients into the sewer. They informed our
investigator that if the weight of BOD in the raw waste ex-
ceeds one percent of the production, weight they investigate
to determine the reason. As shown in Table 6, the BOD
during our sampling period averaged only 0.56 percent of the
production weight. Incidentally, the BOD and SS results of
the plant laboratory analyses for the sampling days corre-
lated very closely with the BOD and SS results of the NCA
Laboratory analyses run on the frozen samples.
Category 4 - Meat Specialties
Plant codes K and L are included in this category. Major
products are ham, sausages, stews, pickled meats, hash, and
chile, plus frozen items such as pre-fried meat patties.
The meats have been slaughtered, dressed and packed else-
where. Added ingredients are largely spices and preserva-
230
-------
tives. Substantial quantities of grease and oil are present
in the waste flow from the cleaning of cooking vats, frying
ovens, and other equipment which comes in contact with the
meat.
The two plants sampled represented opposite ends of the meat
specialties category in terms of amount of processing per-
formed. Plant K is a very small operation preparing a
limited number of products. Processes include grinding,
mixing with additives, then canning and cooking or patty
forming and freezing. Minimal amounts of water are used for
clean-up activities. Plant L on the other hand is a large
meat canning operation preparing a wide assortment of meat
specialties. Processing is more extensive, product changes
more frequent, and waste generation significantly higher
than Plant K.
Tables 8 and 9 show the waste generation and strengths
recorded for the two plants. We believe that Plant L is
more typical of plants producing meat specialties, with BOD
values of 16 kg/kkg (32 Ibs/ton) of production and 1,100
mg/1 concentration. Also, we believe the sampler used at
Plant K may not have taken representative samples due to low
flow volume in the sampler suction tube.
Table 8. CATEGORY 4, AVERAGE POLLUTANTS
CONTAINED IN WASTEWATER PER UNIT
OF PRODUCTION
Plant
code
Constituent (kg/kkg finished product)
COD
BOD
SS
VSS
Total
P
TKN
Grease
and oil
Volume
(1/kkg)
K 5.1 3.0 1.2 0.97 0.086 0.16 0.68 5,700
L 33 16 11 10 0.11 0.98 7.3 15,000
Average 19 9.5 6.1 5.5 0.098 0.57 4.0 10,000
231
-------
Table 9. CATEGORY 4, AVERAGE
WAS TEW ATE R CHARACTERISTICS
Plant
code
Concentration (mg/1)
COD
K 900
K 2,300
Average 1,600
BOD
530
1,100
820
SS
210
720
460
VSS
170
670
420
Total
P TK
Grease
.N and oil
15 28 120
6.7 67 490
11 48 300
Category 5 - Canned Soups and Baby Foods
Plant codes M and N are included in this category. Canned
soups and baby foods, are put in one category because the
plants typically are large, and produce many product varie-
ties which contain different vegetable, meat, starch, and
fruit ingredients. Both plants perform significant raw
product processing of vegetables, as reflected by the rela-
tively high wastewater generation figures shown in Tables 10
and 11. In this respect they are more closely allied with
straight commodity processors than with many other cate-
gories of the specialty foods industry. Major wastewater
sources are plant clean-up; washing, trimming, blanching of
raw vegetables; washing, peeling and coring of raw fruit;
and cooking of meat. Generally, waste discharges will vary
greatly in volume and strength, depending upon which varie-
ties are being manufactured, and the relative quantities of
raw commodities and pre-processed ingredients.
Table 10. CATEGORY 5, AVERAGE
POLLUTANTS CONTAINED IN WASTEWATER
PER UNIT OF PRODUCTION
Plant
code
Constituent (kg/kkg raw product)
COD BOD SS .
M 15 8.5 4.3
N 27 15 11
VSS
3.1
8.4
Total
P
0.068
0.29
TKN
0.19
0.75
Grease
and oil
2.4
Volume
(1/kkg)
15,000
29,000
Average 20 12 7.6 5.8 0.18
0.47
22,000
232
-------
Table 11. CATEGORY 5, AVERAGE
WASTEWATER CHARACTERISTICS
Plant
code
Concentration (mg/1)
COD BC
3D SS
M 1,000 590 290
N 940 520 360
VSS
210
290
Total
P
4.1
10
TKN
12
26
Grease
and oil
—
82
Average
970 560 320 250
7.0
19
Category 6 - Tomato-Cheese-Starch Combinations (Italian
Specialties)
Plant codes O, P, Q and R are included in this category.
Major products are canned and frozen spaghetti, lasagne,
ravioli, frozen pizza, and other italian specialties made
with tomato, starch, and cheese base. These plants were
placed in one category because they typically have the three
principal ingredients listed, all of which are pre-processed
elsewhere. The wastes are generated primarily from spills
and clean-up of blending vats and cooking kettles.
As seen from Tables 12 and 13 this category showed poor
correlation in waste generation. We believe this wide di-
versity is due to selectionvOf three plants which are vastly
different in their operations due to size, product style,
and percent of total plant capacity being used at the time
of sampling.
Plant R is the smallest operation covered in this study.
Processing is done largely by hand. Virtually no water is
used except for end of the day clean-up of equipment. As
shown in the tables, wastewater generation was extremely low
(1,820 1/kkg or 440 gal/ton product). This minimal clean-up
flow provided little dilution, thus the high concentrations.
However, the wastewater volume was so low that even the
higher strength of the waste could not significantly effect
the productivity factor. The 2.6 kg COD/kkg product factor
was the lowest of all.26 plants investigated.
Plant O is a new plant operating at only a fraction of its
design capacity. With increased production to optimum
levels, the use of water for clean-up purposes is expected
to become more efficient in terms of volume per unit produc-
tion and cause the present high productivity factors and
233
-------
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234
-------
Table 13. CATEGORY 6, AVERAGE
WASTEWATER CHARACTERISTICS
Plant
code
Concentration (mg/1)
o
p
Q
R
Average
COD
500
-
340
1,500
780
BOD
240
340
200
690
370
SS
180
-
130
360
220
VSS
150
-
120
330
200
Total
P TJ
10 7,
11.
2.0 5
6.0 34
6.0 15
Grease
CN and oil
6
8
.6 180
wastewater generation to drop significantly. This plant
also prepares institutional salads. Significant amounts of
wastewater are generated by the washing of lettuce and
blanching of other salad ingredients.
Plant P is a very large plant which produces canned tomato-
cheese-starch products. These canned products contain lar-
ger volumes of water than do similar frozen items. High
product water content generates artificially high production
weights and thus lowers substantially the effluent produc-
tivity factors.
To summarize Category 6 we believe that none of the plants
sampled could be called a "typical" situation. It is en-
tirely possible, however, that the pollutant generation
levels shown in Table 12 result in reasonable average values
for this category in spite of the wide ranges.
Category 7 - Sauced Vegetables
Only Plant S whose major product is frozen vegetables with
and without cheese or butter sauce was sampled in Category
7. This category represents plants whose wastes are largely
generated by the washing, peeling, cutting, blanching, and
cooking or freezing of raw vegetables. The addition of
butter sauce, tomato sauce, spices, etc. may technically
235
-------
place this plant under the specialty food category, however,
we believe the waste load is similar to that of a straight
vegetable processor, with added waste load from spillage and
clean-up of sauce equipment.
Plant S generates exceptionally high wastewater volume due
to inefficient water use in the washing, cutting, cooling
and transporting of the produce. The plant is about twenty-
five years old and was designed at the time that water con-
servation and wastewater volume reduction were not con-
sidered important. Little modernization of equipment has
been implemented, and the plant owners will soon be faced
with the choice of large expenditures to reduce volumes dis-
charged to the city sewer, or shut-down. The large volume
provides dilution of pollutant concentrations and the plant
effluent has a low BOD concentration of 300 mg/1.
As can be seen from Tables 14 and 15. the sauce room clean-
up wastewater is high in strength, being comprised of
cheese, margarine and shortening; but it is insignificant in
volume (less than 1 percent of the total wastewater flow).
The sauce room waste accounts for about 15 percent ,of the
total plant COD and BOD loads, 7 percent of the SS load, 27
percent of the total phosphorus load (phosphorus containing
detergents used for sauce room clean-up), and 4 percent of
TKN.
Table 14. CATEGORY 7, AVERAGE POLLUTANTS
CONTAINED IN WASTEWATER PER UNIT
OF PRODUCTION
Plant
code
S
Constituent (kg/kkg finished product)
COD
BOD
SS
VSS
Total
P
TKN
Volume
UAkg)
24-hour 45 25 21 16 0.33 1.1
plant raw
wastewater
85,000
Sauce room 6.4 3.5 1.4 1.3 0.090 0.047 490
clean-up
wastewater
On the basis of this one plant, it appears that the rapid
growth in the sale of sauced vegetables will increase the
pollution load generated by the vegetable processing indus-
try.
236
-------
Table 15. CATEGORY 7, AVERAGE
WASTEWATER CHARACTERISTICS
Plant
code
S
Concentration (rag/1)
COD
BOD
SS
VSS
Total
P
TKN
24-hour
raw
wastewater
560
310
250
200
Sauce room 14,000 8,000 3,300 3,100
clean-up
wastewater
4.4
230
13
100
Category 8 - Sweet Syrups, Jams and Jell-ies
Plant codes T and U fall into this category. Major products
are syrups, fruit toppings, jams, jellies, and preserves.
Typically, the ingredients include fruit, sugar, chocolate,
nuts, cocoanut, and flavorings. Most ingredients are pre-
processed elsewhere. The plants blend various proportions
of ingredients, cook and package the products.
Plant U processed only jams, jellies, and spreads. Plant T
processed a variety of sweetened products plus jello, choco-
late, cocoanut and instant rice. In spite of its variety of
products, Plant T was placed in this category because the
instant rice processing water is separately disposed and not
included in Tables 16 and .17, and the chocolate, cocoanut
and jello are very dry processes which contribute less
wastewater than does the syrup operation.
As seen from the tables the wastes are strong in dissolved
organic strength, but relatively low in pollutant load per
unit weight of production. Major wastewater generation is
from clean-up of mixing vats and cookers during changes in
product runs and at the end of each day. Apparently, clean-
up operations were efficient as indicated by low wastewater
volumes for both plants.
237
-------
Table 16. CATEGORY 8, AVERAGE POLLUTANTS
CONTAINED IN WASTEWATER PER UNIT
OF PRODUCTION
Plant
code
Constituent (kg/kkg finished product)
COD
BOD
SS
VSS
Total
P
TKN
Grease
and Oil
Volume
(1/kkg)
T 5.4 3.0 1.3 1.1 0.076 0.057
U 12 7.2 0.68 0.60 0.019 0.030
Average 8.7 5.1 1.0 0.85 0.048 0.044
0.62
2,700
2,000
2,400
Table 17. CATEGORY 8, AVERAGE
WASTEWATER CHARACTERISTICS
Plant
code
Concentration (mg'/l)
COD
BOD
SS
VSS
Total
P
TKN
Grease
and Oil
T 2,000 1,100 470 410 28 21
U 6,100 3,600 340 300 9.6 15
Average 4,000 2,400 400 360 19 18
230
Category 9 - Chinese and Mexican Foods
Included in this category are plant codes V, W and X. Major
products are Chinese specialties such as chop suey, chow
mein, and fried rice; and mexican specialties such as thick
vegetable sauces, hot peppers and dip mix.
These plants correlated well because the product of all
three plants is canned and high in vegetable content.
A substantial portion- of the raw vegetables are processed
at the plants while all other ingredients are pre-prepared
elsewhere. Major waste flows originate from washing and
blanching of vegetables, and from clean-up of mixing and
cooking vats. Tables 18 and 19 show waste generation and
strength. BOD generation averages 7 kg/kkg (14 Ibs/ton) of
production and 570 mg/1.
238
-------
Table 18. CATEGORY 9, AVERAGE POLLUTANTS
CONTAINED IN WASTEWATER PER UNIT
OP PRODUCTION
Plant
code
Constituent (kg/kkg
COD
V 12
W 12
X 12
BOD
6.3
6.7
7.8
SS
2.4
4.0
1.9
VSS
2.2
3.8
-1.2
Total
. P
0.084
0.041
0.29
finished product)
TKN
0.36
0.27
0.21
Grease
and Oil
1.2
4.7
-
Volume
dAkg)
14,000
18,000
8,900
Average 12 6.9 2.8 2.4 0.14
0.28
3.0
14,000
Average
Table 19. CATEGORY 9, AVERAGE
WASTEWATER CHARACTERISTICS
Plant
code
Concentration (mg/1)
COD
V 830
W 670
X 1,200
BOD
450
370
900
SS
170
220
210
VSS
160
210
140
Total
P TK
6.0 26
2.3 15
34 22
Grease
N and Oil
85
260
-
900 570 200 170
14
21
170
Category 10 - Breaded Frozen Products
Included in this category are plant codes Y and Z. Plant Y
breads mushrooms, onions, and pre-processed perch after
minimal washing. Plant Z prepares fish and shellfish that
have been cleaned and dressed at a seafood processing plant.
Generally, the seafood is thawed, washed, dried, dipped in
batter, breaded and frozen. The breaded seafood is not
fried. The major wastewater sources are plant clean-uo,
washing and rinsing of raw product, and thawing of frozen
raw seafood in the case of Plant Z.
239
-------
Tables 20 and 21 show the wastewater generation and
strengths of the effluent from the two plants. Plant Z
utilizes huge volumes of water to thaw and frequently wash
the product. As a result, waste strength is a relatively
low 400 mg/1 BOD. Plant Y is primarily a producer of
breaded onion rings. The batter is very rich and clean-up
of equipment and spills results in a wastewater with an
average BOD of 4,500 mg/1. In direct contrast to Plant Z,
Plant Y operation generates very little wastewater but pro-
duces the strongest waste of all plants investigated.
Table 20. CATEGORY 10, AVERAGE POLLUTANTS
CONTAINED IN WASTEWATER PER UNIT
OF PRODUCTION
Plant
code
Constituent
COD BC
DD SS
Y 40 15 23
Z 66 37 30
VSS
23
29
(kg/kkg raw
Total
P
0.12
0.58
TKN
0.33
4.8
product)
Grease
and Oil
1.2
-
Volume
(lAkg)
3,300
92,000
Average 53
26
26
26
0.35
2.6
48,000
Table 21. CATEGORY 10, AVERAGE
WASTEWATER CHARACTERISTICS
Plant
code
Concentration (mg/1)
COD
Y 12,000
Z 720
Average 6,400
BOD
4,500
400
2,400
SS
7,100
330
3,700
VSS
7,100
320
3,700
Total
P TK
Grease
N and Oil
37 100 360
6.3 52
22 76
These plants illustrate the differences between two plants
with similar major process techniques (i.e., raw product
cleaning, cutting, battering, breading, freezing) but with
different water usage patterns; one being a very wet opera-
tion and the other very dry.
240
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STANDARD RAW WASTE LOADS
Table 22 below summarizes average wastewater productivity
factors for all categories in terms of kilograms of pollutant
per thousand kilograms of finished product. Using COD as a
measure of organic strength, Table 22 shows that category 10
(breaded frozen products) and category 2 (frozen bakery prod-
ucts) produce approximately 50 kg of COD per 1,000 kg of
production (100 Ibs/ton). The lowest category in terms of
COD production is number 8 (sweet syrups, jams and jellies)
in which the two plants sampled produced an average of only
9 kg of COD per 1,000 kg of production (18 Ibs/ton). Values
of BOD's generally ran about 50 percent of COD values in the
samples analyzed.
Average values for other waste constituents shown in Table
22 generally indicate that the industry produces suspended
solids (SS) which are highly organic (VSS), the wastes are
often deficient in nutrients (Total P and N) which must be
added for satisfactory biological treatment, that grease and
oil are significant ingredients where substantial frying is
done, and finally, that wastewater volumes vary greatly.
TABLE 22. AVERAGE POLLUTANTS CONTAINED
IN WASTEWATER PER UNIT OF PRODUCTION,
BY CATEGORY
(kg/1,000 kg)
Category
Average productivity factors (kg/kkg product)
COD
BOD
SS
VSS
Total
P
TKN
G&O
Volume
d/kkg)
1
2
3
4
5
6
7
8
9
10
34
52
13
19
20
17
45
8.7
12
53
17
23
7.5
9.9
12
7.2
25
5.1
6.9
26
14
14
3.5
6.1
7.6
6.0
21
1.0
2.8
26
14
14
3.4
5.5
5.8
5.6
16
0.85
2.4
26
0.19
0.082
0.028
0.098
0.18
0.28
0.33
0.048
0.14
0.35
0.44
0.30
0.037
0.57
0.47
0.23
1.1
0.044
0.28
2.6
15
11
5.7
4.0
2.4
4.7
—
0.62
3.0
—
12,000
11,000
2,800
10,000
22,000
29,000
85,000
2,400
14,000
48,000
Table 23 on the following page summarizes average raw
wastewater constituent concentrations for all categories.
With few exceptions the average results reflect typical
food processing wastes which are very high in COD and
241
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Table 23. AVERAGE WASTEWATER
CHARACTERISTICS BY CATEGORY
Category
Constituents (mg/1)
COD
BOD
SS
VSS
Total
P
TKN
G&O
1
2
3
4
5
6
7
8
9
10
3,900
7,000
4,700
1,600
970
780
560
4,000
900
6,400
1,900
3,200
2,600
820
560
370
310
2,400
570
2,400
1,500
2,200
1,200
460
320
220
250
400
200
3,700
1,500
2,100
1,200
420
250
200
200
360
170
3,700
21
6.8
11
11
7.0
6.0
4.4
19
14
22
45
36
14
48
19
15
13
18
21
76
2,000
820
2,000
300
82
180
-
230
170
360
BOD concentrations, and organic suspended solids. In gen-
eral, the wastes are amenable to discharge into municipal
systems for joint treatment. In certain instances, pre-
treatment may be required for removal of grease and oil to
prevent deposition in the municipal collection system.
Where the specialty food processing plant provides final
treatment and disposal, the wastes can be successfully
treated with properly designed biological treatment pro-
cesses.
It is important to note the wide differences (more than
10:1) in waste strength between categories of the specialty
food industry as shown in Table 23. This wide difference in
waste strength is due to a variety of reasons, the most sig-
nificant of which are summarized in the following para-
graphs.
Richness of product ingredients. All food proces-
sing plants undergo extensive clean-up of equipment,
floors, spillages, etc. The principal waste com-
ponents of the wash water are the ingredients used
in product manufacture. Where these ingredients
are high in fats, carbohydrates, sugar, etc. the
resultant waste is correspondingly strong. As an
example, the categories showing the highest gener-
ation of organic wastes were frozen breaded prod-
ucts, which use a rich egg batter, and frozen
242
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bakery desserts which use large quantities of but-
ter, eggs, and sugar.
Number and type of processes performed. The plant
process line may consist of many steps (cooking,
blending, etc.) or very few. The individual process
steps may contribute heavily to wastewater genera-
tion (blanching, washing, etc.) or very little. It
was beyond the scope of this project to investigate
wastes generated by individual process steps, how-
ever, even casual observation revealed the signifi-
cance of this aspect.
Number of different products and frequency of
changes in product. As a rule when the type of
product is changed all equipment in the process
line is thoroughly cleaned. Therefore, plants
which have relatively short runs of many different
products generate more clean-up waste than do plants
which run the same product for many days.
Moisture content of ingredients and the final prod-
uct. In this report pollution generation factors
are calculated per unit weight of product. A major
shortcoming of this approach is that the moisture
of ingredients and products varies widely. For
example, a canned spaghetti plant will produce less
pollution per unit weight of production than a fro-
zen pizza plant even though both are primarily a
starch and tomato product. The canned spaghetti
product has a much higher moisture content - there-
fore weighs more - and shows lower pollution prod-
uctivity per unit weight of production.
Management desire to reduce waste generation. With-
out question, a major factor in waste generation
from any plant is the presence or absence of in-
plant waste management programs designed to minimize
waste disposal to the sewer.
Other factors. A multitude of other factors may
have a significant effect upon wastewater generation
from a particular plant. These include, plant size,
number of shifts, percentage of production capacity
in use, cost of water supply and wastewater dispos-
al, degree to which ingredients have been pretreated
elsewhere, and economic ability of the plant to mod-
ernize equipment.
243
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CURRENT TREATMENT TECHNOLOGY
The specialty food plants investigated exhibited a wide
spectrum of wastewater treatment facilities from no treat-
ment to extensive biological and physical-chemical systems.
While evaluation of waste treatment systems was outside the
scope of the project, a brief description of study team ob-
servations is provided.
Of the 26 plants investigated, 6 provided the equivalent of
secondary treatment using biological systems in conjunction
with other unit processes. The most extensive treatment
facility observed is described in the case study for plant
A (See appendix) and is reported to achieve in excess of 99
percent BOD reduction on raw waste with average BOD levels
of 4,000 mg/1. The treatment facility has a design capacity
of 350,000 gpd and is estimated by the owner to have a re-
placement value of approximately 3 million dollars. Other
excellent secondary and tertiary treatment facilities were
observed at Plants F, T and N. Plant D utilizes a land
disposal system which has successfully operated for over 20
ye ars.
Twenty-one of the 26 plants investigated discharged into
municipal systems. Plants O and H provide activated sludge
pre-treatment in order to reduce BOD levels 90 percent or
more prior to discharge into the municipal sewer. Each is
a large plant located in a small community. Plant V pro-
vides only screening on its' waste, but is reported to have
a long term arrangement with the small community where it
is located whereby the company pays approximately 85 percent
of all capital and operating costs for municipal sewage
treatment facilities.
Of the other 18 plants investigated, 4 provided no pre-
treatment, 2 provided grease traps only, and the remainder
provided various degrees of screening, settling, or flota-
tion prior to discharge to sewers. Several clarification
operations utilized chemical treatment for pH adjustment and
to promote coagulation and emulsification.
Table 24 summarizes the treatment at each plant investiga-
ted. There is no correlation between category and degree
or type of treatment..
244
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Table 24. SPECIALTY FOOD PLANT
WASTEWATER TREATMENT OPERATIONS
Treatment Plants utilizing
None J, R, U, Y
Collation baskets in E
drains (only)
Grease trap (only) F, K
Screening A, C, M, N, P, Q,
S, T, V, W, Z
Settling A, B, C, D, F, G,
H, I, L, N, T,
X
Coagulation B, N, W
Trickling filtration A, N
Activated sludge
Conventional A, H
Extended aeration O, T
Lagooning
Anaerobic A
Aerobic P
Aerated F, N, P
Dissolved air flotation A, B, F, N, W
Chlorination A, F, N, P
Sand filtration F
Land disposal D, N, P
(partial or total)
245
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PAUNCH MANURE AS A FEED SUPPLEMENT IN
CHANNEL CATFISH FARMING
by
S. C. Yin*
INTRODUCTION
One of the most serious problems faced by the meat-packing industry in
attempting to comply with the increasingly more stringent pollution con-
trol regulations is the finding of an acceptable means to dispose of
paunch manure from slaughtered cattle. The feasibility of drying paunch
manure and incorporating it as a feed supplement for the commercial pro-
duction of channel catfish was reported earlier (1, 2). By so doing, it
would relieve the meat-packer from having to deal with this material as
a probelm waste and transform it into a useful by-product. Following
those preliminary feasibility studies, the Environmental Protection Agency
awarded a grant to the Oklahoma State University for investigation on a
scale simulating commercial enterprises to determine whether channel cat-
fish could be grown on specially formulated feeds containing various
substitution rates of dried paunch manure at growth rates (in one growing
season) which would compare favorably with control fish given standard
commercial catfish feed. This paper gives a summary of the findings of
this completed project which was designated EPA Grant No. R-800746
(12060 HVQ). The final report on this project is in its final stages of
preparation for printing, and should be available for distribution before
long.
MATERIALS AND METHODS
Experimental Feeds
Two tons of dried paunch manure was donated by Beefland International, Inc.
This meat-packing company, located at Council Bluffs, Iowa, was the recip-
ient of another EPA grant which dealt with the technology and economics of
*Environmental Protection Agency, NERC,Corvallis, Robert S. Kerr
Environmental Research Laboratory, Ada, Oklahoma 74820.
246
-------
drying paunch and blood. That completed project was reported by Baumann
(3). This dried paunch was transported to a commercial feed manufacturer
who contracted to supply the standard feeds and to formulate the experi-
mental feeds for this project.
Table 1 shows the composition of the feeds used. The feeds were formu-
lated in such a manner that all of them were essentially isonitrogenous
(that is, equal in protein nitrogen content) and isocaloric (that is,
equal in caloric value per unit weight). The sinking feeds were for the
pond-reared fish and the floating feeds were for the caged fish. The
original plan was to use feeds containing 20% and 30% paunch in both pond
and cage cultures. Unfortunately, the plant which produced the floating
pellets was located near a residential area. Dried paunch, which is
practically odorless, produced a highly objectionable odor when remoistened
during the manufacturing process. For this reason, the plant manager,
fearing complaints from the nearby residents, refused to proceed further
after finishing the batch containing 10% paunch. Anyone who has experi-
enced the odor of fresh, wet paunch manure can easily sympathize with
that decision. Unless this undesirable quality of paunch can be overcome,
it may become an important factor in limiting its adoption by the feed
industry for incorporation into feed of any kind.
Table 1. Composition (%) of Commercial Catfish Feeds, Sinking Feeds
Containing by Weight 10-30% Paunch, and a Floating Feed
Containing 10% Paunch
Floating feeds Sinking feeds
Ingredient Commercial 10% Commercial 10% 20% 30%
Protein, Kjeldahl 38.6 38.7 32.2 34.9 33.5 33.1
Fat, ether extract 3.3 3.1 4.6 3.7 3.7 3.7
Fiber 5.8 5.1 7.9 8.3 10.2 10.7
Calcium 1.22 1.32 0.42 0.53 0.57 0.67
Phosphorus 0.93 1.13 0.98 0.85 0.75 0.73
Calories, KC/G 4.16 4.25 4.15 4.28 4.34 4.32
247
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Fish Cultures
The layout of the ponds constructed for this project is shown in Figure 1.
The size of the ponds used for pond cultures was 0.1 hectare each, and
the cage culture ponds were 0.4 hectare each. Ponds 6 and 10 were control
ponds for water quality monitoring, in which there were no fish stocked,
and no feed of any kind was added to these two ponds during the course
of the experiment. The cages used were constructed of aluminum frame
and vinyl-coated wire mesh, each measuring 0.91m tall, 0.91m wide, and
1.37m long. They were buoyed with styrofoam so that a submerged depth
of 0.81m with a water volume of l.Om^ was obtained. These cages were
tethered to a pier in each of the two cage culture ponds.
The size and number of fingerlings chosen to stock the ponds and cages
were planned to simulate average commercial yield (kg/ha) while obtaining
an "ideal" market size fish within a 168-day growing season. In consid-
ering these objectives, a number of authoritative publications with
varying viewpoints (4, 5, 6, 7, 8, 9) was consulted before the following
decisions were made:
(a) In the pond cultures, each 0.1-ha pond was stocked with
260 fingerlirgs of 70g each. This stocking density (2600/ha)
was considered maximum commensurate with the basic objective
of a yield of about 1408 kg and a final average weight of
568 g. Assuming a mortality rate of 4%, the number of fish
stocked in each pond was ten more than the number expected
to survive the investigative period.
(b) Each of the three cages in each of the 0.4-ha ponds was
stocked with 345 fingerlings of the same size as used
in the pond cultures. This stocking density (2587/ha)
was selected not only to be consistent with commercial
practice as recommended by top researchers in the field,
but also to duplicate the densities in the pond cultures,
so that the waste loading from the fish and from uneaten
feed in both types of culture ponds would be expected to
be equal. Thus, comparison of the effects on water
quality between the two cultural methods would be more
meaningful.
The daily ration of feed given to the fish in all ponds was based on
an average of three percent of the body weight. For this purpose, samples
of fish from each pond and each cage were taken every 28 days and the
fish were anesthetized for length and weight measurements.
Water Quality Analyses
One justifiable concern of utilizing paunch as a fish feed constituent
is its potential as a water pollutant. Since fresh paunch has a high bio-
chemical oxygen demand (BOD), over eighty percent of which was found in
the water soluble fraction (1, 2), if feed containing dried paunch is not
248
-------
C213
LJ l^J
C233
POND CULTURE
NO FEED
STD. FEED
10% PAUNCH
20% PAUNCH
30% PAUNCH
CAGE CULTURE
STD. FEED
10% PAUNCH
CAGE NO.
31,32,33
21,22,23
1 A-MAINTENANCE BUILDING
AND LABORATORY
Figure 1. Experimental fish ponds used in pond (5-16) and cage culture
(2 and 3) experiments. The tabular inset describes the experimental
design. The cages used in ponds 2 and 3 are shovri with [ ].
249
-------
eaten by the fish within a reasonably short time after the feed is intro-
duced into the water, the paunch in the feed could very well become a
serious water pollutant. Therefore, it was decided to monitor the water
quality of the ponds during the course of the investigation to see if
this fear is indeed a reality and leads to a problem which would preclude
the use of paunch for this purpose.
Because of the shortage of funds and manpower, it was not possible to
monitor all of the ponds. The ponds selected for water quality monitoring
were the following:
(a) Ponds 6 and 10, which were the two control ponds in which
no fish were stocked and where no feed of any type was
added to the water during the whole 168-day period.
(b) Ponds 2 and 3, which were the cage culture ponds.
The fish in pond 2 received feed containing 10% paunch,
while those in pond 3 received standard commercial
feed.
(c) Ponds 9 and 12, which were the replicate ponds in the
pond culture where the fish received standard commercial
feed.
(d) Ponds 8 and 14, which were the replicate ponds in the
pond culture where the fish received feed containing
the highest proportion of paunch—30%.
This part of the investigation—the water quality studies—was a coopera-
tive effort between Oklahoma State University and EPA's Robert S. Kerr
Environmental Research Laboratory. A total of seventeen parameters was
included in the analyses. These were pH, dissolved oxygen, temperature,
carbon dioxide, biochemical oxygen demand (5-day), chemical oxygen demand,
total organic carbon, ammonia, total Kjeldahl nitrogen, nitrite, nitrate,
total phosphate, orthophosphate, total solids, total suspended solids,
volatile suspended solids, and fecal coliforms. Samples were collected
weekly by O.S.U. personnel who also measured the first four parameters
listed above at the site of the ponds. Each sample was pooled from three
separate samples that were taken at different times during the daylight
hours of the sampling day. Once every four weeks, however, both pooled
daytime and nighttime samples were taken. For those analyses that were
not performed at the site of the ponds, the samples were iced and trans-
ported to the Kerr Laboratory in Ada, Oklahoma, where the analyses were
done.
RESULTS AND DISCUSSION
The details of all the data obtained in this investigation and the
statistical analyses of these data will not be presented here in the short
time available. Those who are interested in these details will be able
250
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to study them in the final project report which will soon be available.
Only the salient points of the findings will be given in this presentation.
Table 2 shows the yields of the pond-reared fish at the end of the 168-day
growing season which was terminated on November 2, 1972. Yield is defined
as the biomass of fish present at the time of harvest; i.e., when the pond
was drained. Ponds 11 and 15 were the ponds in which the fish were not
Table 2. Yield of Channel Catfish on November 2 from 0.1 ha Ponds and
Amount of Feed Added During the 168-day Growing Season3
Treatment Yield/ponds Amount (kg)
Pond kg Feed added
Standard feed
9b 147.60 201.88
12 110.42 215.45
Avg. 129.01 208.66
Feed with 10% paunch
13 123.96 211.90
16 132.73 223.02
Avg. 128.35 217.46
Feed with 20% paunch
5 120.25 216.62
7 126.50 190.95
Avg. 123.38 203.79
Feed with 30% paunch
8
14
Avg.
No supplemental feed
11
15
Avg.
104.16
109.91
107.04
16.78
21.85
19.32
178.72
187.02
182.87
0
0
0
times 10 = yield/ha
"A 13% loss of fish due to poaching accounts for the low yield.
251
-------
given any supplemental feed but lived only on whatever natural food they
were able to find in the pond. The average yield of these two ponds was
only 15.7% of the average yield of the other eight ponds where supple-
mental food was given. Average yields for ponds 9 and 12 (standard feed),
for ponds 13 and 16 (10% paunch), and for ponds 5 and 7 (20% paunch) were
quite similar, as were the average amount of feed added. The average
yield of ponds 8 and 14 (30% paunch), however, was significantly lower.
But it was also noteworthy that the amount of feed added, which was based
on the average weight of the fish sampled every 28 days, was also signifi-
cantly lower than those added to the other ponds. Because slower growing
fish would, therefore, be fed less food, it is possible that yield merely
reflects the total quantity rather than the quality of the food eaten.
Table 3 shows the mean condition factor, mean length, and mean weight of
the fish receiving different treatments. Again, the means for the fish
in the pond cultures where standard feed, feed with 10% paunch, and feed
with 20% paunch were used were essentially equal, whereas those for the
fish which were given feed containing 30% paunch were significantly lower.
In the cage cultures, the three means for the fish given feed containing
10% paunch were significantly lower than those given standard commercial
feed, and the means of the fish in both of these cage cultures were
significantly lower than those in the pond cultures. Fish confined in
cages are unable to supplement their diet with natural food present in
the pond. Hence, deficiencies in the feed ingredients are apt to be more
pronounced than for pond-reared fish. Also, for this same reason, it is
expected that fish in pond cultures given the same kind and quantity of
food as fish reared in cages will show a faster and greater growth rate.
However, in spite of a**slower growth rate shown by the caged fish as com-
pared to the pond-cultured fish, the caged fish in both ponds (standard
feed and 10% paunch feed) showed better feed conversion than the pond-
cultured fish, regardless of the type of feed, as shown in Table 4. The
"S" conversion factor is obtained by dividing the weight in kilograms of
feed added by the weight gain in kilograms, while the "C" conversion
factor is obtained by dividing the weight in kilograms of feed added by
the adjusted weight gain, which is the weight gain in kilograms minus the
weight gain in kilograms expected if the fish had not been given any
supplemental feed. This last weight gain, of course, is obtained from
the weight gain shown by the fish in the control ponds 11 and 15 which
lived only on the natural food they could find in the ponds. The average
weight gain in these two ponds was 2.37 kg per pond. Thus, the smaller
the conversion factor, the better is the feed conversion. Also, since
the "S" factor includes weight gain due to natural foods, and since
caged fish are practically totally dependent on supplemental food, in
comparing feed conversion between pond-reared fish and cage-reared fish,
it would be more accurate to compare the "C" factor of the former with
the "S" factor of the latter.
Table 5 shows the comparative costs of producing catfish using standard
commercial feeds and feeds containing various levels of paunch. The
252
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Table 3. Mean Condition Factor (K_L), Length, and Weight of Pond-Reared
(TRTS 1-5) and Cage-Reared (TRTS 6+7) Channel Catfish on
May 18 and November 2
TRT Feed, Pond and
No. No. in ( )
1 None
(11 + 15)
2 Std. sinking
(9 + 12)
3 10% paunch
(13 + 16)
4 20% paunch
(5 + 7)
5 30% paunch
(8 + 14)
6 Std. floating
(31, 32, 33)
7 10% paunch
(21, 22, 23)
Cage
^L
Length (mm)
Mass (g)
Length (mm)
Mass (g)
KTL
Length (mm)
Mass (g)
KTL
Length
Mass (g)
KTL
Length (mm)
Mass (g)
KTL
Length (mm)
Mass (g)
KTL
Length (mm)
Mass (g)
May 18
0.66
212.6
65.2
0.66
218.9
71.2
0.67
212.8
66.4
0.70
216.4
71.4
0.67
219.7
72.5
0.66
202.0
57.7
0.68
227.0
82.8
November 2
0.67
227.0
80.4
0.94
385.6
547.4
0.86
388.4
507.4
0.87
384.2
502.7
0.84
367.2
419.0
0.97
335.5
360.2
0.93
321.7
313.2
253
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Table 4. Channel Catfish Conversion Factors of Fish Reared in Ponds
Given a Standard Commercial Feed or Feeds Containing 10, 20,
and 30% Paunch, and Conversion Factors of Cage-Reared Fish
Given a Standard Feed or Feed with 10% Paunch
Conversion factor
Treatment
pond
Std. feed
Pond 9
Pond 12
TRT Avg.
10% paunch
Pond 13
Pond 16
TRT Avg.
20% paunch
Pond 5
Pond 7
TRT Avg.
30% paunch
Pond 8
Pond 14
TRT Avg.
Std. feed
Cage 32
Cage 33
TRT Avg.
10% paunch
Cage 22
Cage 23
TRT Avg.
Feed
added (kg)
201.88
215.45
208.66
211.90
223.02
217.46
216.62
190.52
203.57
178.72
187.02
182.87
153.53
147.08
150.30
124.87
118.04
121.45
Weight gain (kg)
Total Adjusted
PONDS
128.10
92.87
110.48
105.76
116.38
111.07
101.69
106.94
104.32
84.66
91.71
88.18
CAGES
94.72
139.08
116.90
84.80
75.74
80.27
125.73
90.50
108.12
103.39
114.01
108.70
99.32
104.57
101.94
82.29
89.32
85.82
S
1.58
2.32
1.89
2.00
1.92
1.92
2.13
1.79
1.78
2.11
2.04
2.07
1.62
1.06
1.28
1.47
1.56
1.51
C
1.60
2.38
1.93
2.05
1.96
2.00
2.18
1.82
2.00
2.17
,2.09
2.13
254
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Table 5. Comparative Feed Costs to Produce Channel Catfish Using the
Standard Feeds and Feeds with Various Levels of Paunch
Culture System
feed type
Cost of feed
$/kg
Conversion
factor
Cost of feed $/kg
S C
Pond Culture-Sinking Feed
Standard commercial 0.106
Feed with 10% paunch 0.104
Feed with 20% paunch 0.115
Feed with 30% paunch 0.137
Cage Culture-Floating Feed
Standard commercial 0.176
Feed with 10% paunch 0.178
1.89
1.92
1.78
2.07
1.93
2.00
2.00
2.13
1.28
1.51
0.20
0.20
0.20
0.28
0.20
0.21
0.23
0.29
0.22
0.27
comparisons were based on prices existing at the time the study was
initiated, i.e., March 1972. Cost of dehydrated paunch was estimated to
be $22.05 per metric ton, f.o.b., Omaha, Nebraska. For the sinking feeds
used in pond cultures, the only experimental feed containing paunch that
did not cost more than the standard commercial feed to produce the same
weight of fish was the 10% paunch-containing feed. Feeds containing higher
percentages of paunch cost more because to make the feeds isonitrogenous
(i.e., having the same protein content as the standard commercial feed)
more higher priced, high protein constituents such as fish and soybean
meals have to be added to make up for the protein deficiency of paunch.
In the cage cultures, the cost to produce one kilogram of fish with
floating feed containing 10% paunch was considerably higher than the cost
using standard commercial feed. Unless the saving to the meat-packer in
not having to treat the paunch as a waste is taken into consideration,
it would not be economical to raise channel catfish by incorporating more
than 20% paunch into the feed in pond culture, and any at all in cage
culture. Nevertheless, with more stringent waste discharge regulations
facing the meat industry, this saving may become an important consideration
that should not be overlooked in considering the cost.
255
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The data obtained in the water quality studies revealed that the sinking
feed containing 30% paunch and the floating feed containing 20% paunch
did not have any significant adverse effects on the water quality as com-
pared to standard commercial feed. Moreover, although the water quality
of all the ponds in which fish were kept in this investigation had deterio-
rated to some degree by the end of the 168-day period, the deterioration
in none of the parameters measured was sufficiently great to have caused
concern. In all ponds, fresh water was added as needed to maintain a
constant water level. Statistical analyses of the data showed that under
the experimental conditions described which were designed to simulate
commercial production, the water quality of all the ponds—both pond and
cage cultures—had not deteriorated to any appreciable degree in this
one growing season. In this study, it was demonstrated that incorporation
of as high as 30% dried paunch in sinking feed and 10% in floating feed
for the production of channel catfish will not cause any greater water
pollution than the use of standard commercial feeds.
CONCLUSIONS
It is feasible to use dehydrated paunch as a feed constitutent in formu-
lated feeds for pond-rearing channel catfish. Levels of 10 to 20% paunch
can be used without producing a significant reduction in growth as com-
pared to fish reared on a typical commercial feed. Economically, levels
of paunch up to 20% may be used without increasing the feed costs per kg
of fish flesh produced. Thus, paunch is economical as a feed constituent
in formulated feeds for pond-rearing of channel catfish up to a 20% level.
For cage culture, however, paunch at 10% substitution level would not
produce a desirable economic return, and only smaller amounts may be used.
The fish harvest obtained in the present study averaged 1219 kg/ha. At
this density none of the water quality parameters limited growth or pro-
duction. There was no evidence that at production levels typical of
average commercial catfish farming that metabolic wastes have a negative
feedback on fish growth or production.
Under the experimental conditions of the present study which endeavored
to simulate typical catfish farming techniques, fish culture did not cause
appreciable water quality deterioration in one growing season. Moreover,
there was no significant difference in water quality between ponds using
a typical commercial feed and a feed containing dehydrated paunch. At
similar densities, there was no difference in water quality between ponds
using cage- and pond-rearing techniques.
256
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REFERENCES
1. Yin, S. C., R. C. Summerfelt, and A. K. Andrews. 1972. Dried cattle
paunch manure as a feed supplement for channel catfish, p. 75-82. In
Proc. 23rd. Okla. Ind. Waste and Advance Waste Conf., April 3-4, 1972,
Oklahoma State University, Stillwater, Oklahoma.
2. Yin, S. C. and J. L. Witherow. 1972. Cattle paunch contents as fish
feed supplement: feasibility studies, p. 401-408. In Proc. 3rd. Nat.
Symp. on Food Processing Wastes, Mar. 28-30, 1972, New Orleans,
Louisiana (EPA Pub. No. EPA-R2-72-018).
3. Baumann, D. J. 1971. Elimination of water pollution by packinghouse
animal paunch and blood. Water Pollution Control Research Series.
EPA Pub. No. 12060 FDS 11/71.
4. Bureau of Commercial Fisheries. 1970. A program of research for the
catfish farming industry. U. S. Dept. Commerce, Economic Development
Adm., Tech. Assist. Proj. XIII. 216 p.
5. Bureau of Sport Fisheries and Wildlife. 1970. Report to the fish
farmers. U. S. Dept. Interior, Bureau of Sport Fisheries and Wildlife,
Resource Pub. No. 83, 124 p.
6. Meyer, F. P. 1969. Where do we stand?, p. 8-11. In Proc. 1969 Fish
Farming Conf., Texas Agr. Ext. Serv., Texas A&MUniv., College Station,
Texas.
7. Collins, R. A. 1970. Cage culture of catfish: research and private
enterprise. Catfish Farmer 2(4):12-17.
8. Lewis, W. M. 1970. Suggestions for raising channel catfish in
floating cages. Unpublished multilith report of Fisheries Research
Laboratory, Southern Illinois Univ., Carbondale. 5 p.
9. Schmittou, H. R. 1970. Developments in the culture of channel
catfish, Ictalurus punctatus (Rafinesque), in cages suspended in
ponds. Proc. S. E. Assoc. Game & Fish Comm. 23(1969): 226-244.
257
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I
PRETKEATMENT OF VEGETABLE OIL REFINERY WASTE WATER
•by
Alex Grinkevich*
INTRODUCTION
The production of a finished product of edible oils requires the use of
processes which progressively remove incremental amounts of impurities
and undesirable oil constituents from the crude oil until it has reached
the clear, bright, odorless high quality cooking or salad oil or the pure
white solid shortening that the American consumer enjoys.
For years the technology of the edible oil industry was directed,to achieving
a high quality consumer product by removing these impurities from the oil
and achieving a high level of .cleanliness in the product container, shipping
and storage tanks, the plant areas which the processes occur, et^. etc.
Almost without exception when a new gain in product purity or'plSffb
cleanliness was achieved, the undesired constituent was transferred
eventually to a waste water stream and was discharged from the plant, thus
presenting a clean-up problem downstream at a waste water treatment plant
or a river or other surface water. For years this waste was some one elses
problem; however, recent Federal legislation has required that the discharger
control and abate the nuisances generated by his discharge. Hence, at a
rather late date the edible oil industry has turned its technology and
attention to waste water. Like others, this industry found it knew very
little about waste water. \_
OUTLINE OF THE PROBLEM
In the edible oil industry, not surprisingly, the largest single problem
is oil removal from the waste water system. If the free and emulsified
oils are removed the BOD and suspended solids are reduced almost propor-
tionately to the oil reduction.
Consider the problem:
(l) A modern oil refinery will have a product throughput ranging from
1/2 million to 1-1/2 million pounds of finished product per day.
(2) During this processing, the oil will pass through several individual
processes such as (l) the first refining (2) the second refining
(3) deodorizing (h) winterizing (5) hydrogenation and (6) packaging
or loading of bulk shipment vehicles. Thus, to produce one (l)
million pounds of finished product, the oil will be sent through a
minimum of 6 processess which means that 6 million pounds of oil are
handled to produce a million pounds. Actually, the product is
stored in intermediate storage tanks in its way through the refinery
so that more realistically it is handled and pumped more than 15 to
20 times. Thus, production of one (l) million pounds of finished
oil will require handling about 20 million pounds of oil through
the incremental processes.
From the above, one would expect some leaks, spills, clean-ups,
drainage of pipes to make repairs, etc., all of which will find
*HUNT-WESSON FOODS, INC., FULLERTON, CALIFORNIA
258
-------
its way to the waste water stream. If you have a handling efficiency
of 99.1*1$ the losses to waste water would be 112,000 # oil,
clearly unacceptable. What is acceptable to the inlet of a
municipal treatment plant is 100 mg/1 FOG which at 300 GFM of
waste water amounts to 3^6 $ oil/day which is a loss of . 001173$>
or an efficiency of 99.8827^.'
(3) In the refining, deodorizing and acidulation of soapstock, direct
contact of water with the oil is inherent in the process itself
so that when the products are purified a direct transfer of the
impurities is made to the waste water steam together with an
additional amount of oil which goes over to the waste water in
the form of oil-water emulsions.
(1*) The quantity of wastes which wind up in the waste water are
directly related to the free fatty acid content which is in the
available crude oil. This factor is outside the control of the
refinery manager. He must process the available oil. The free
fatty acid concentration can vary widely.
(5) In addition to the oil that is transferred to the waste water,
a large amount of water soluble highly complex organic materials,
originally present in the raw oil, leave the raw oil and wind up
in the waste water stream. This is particularly true of waste
water from the acidulation of soapstock which creates a waste
having characteristics of 1*, 000-90,000 mg/1 BOD and 200-10,000
mg/1 hexane extractables or fats, oils and grease, which will be
hereafter designated F.O.G.
Depending on the design of the individual refinery the total water stream
could vary from 100 gpm to 1*,500 gpm. We have one refinery rated at
1 million #/day, that was built in the early 1900's on the bank of a
very large river. The refinery was built to use once through river water.
It represents the 1*,500 gpm figure. We are very busy installing
cooling towers, repiping to achieve maximum reuse of water and expect
to reduce the water discharge to approximately 200-300 gpm. I suspect
that with optimization this can and will be reduced further but the
waste concentration will be spectacular. An achievable level of water
use for a complete refinery employing conventional processes, including
acidulation of soapstock, appears to be about 200 gpm for 30,000 $ oil/hr.
This works out to 0.28 gal. of water per pound of refined oil.
Typical edible oil refinery waste water would have characteristics in
the following range: BOD 500-6,700 mg/1
FOG 300-1*,200 mg/1
SS 541-5,851 mg/1
The range is wide because of the factors previously mentioned,
variability due "to accidental spills, leaks which reflect state of repair,
dilution, free fatty acid content of the incoming raw oil, etc.
Let me describe a system recently installed and started-up in a mid-
west refinery which refines animal and vegetable fats to make solid
shortening. This plant also refines soy and cottonseed oil to produce bottled
salad oil. Since animal oils are used, the plant comes under
259
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Meat Inspection Department of Department of Agriculture (M.I.D.).
Consequently, a clean-up crew of 10 people are constantly scrubbing
down equipment, floors, concrete aprons, the paved tank farm, etc.
Recent figures show plant consumption of special commercial cleaning
compounds at approximately 6,500 #/month. This is above counting
the 50$ caustic used for clean-up. Some product is shipped in tank
cars so the operation of washing Railroad tank cars is present. Plant
processes include caustic refining, deodorizing, winterizing,
bleaching, hydrogenation, acidulation of soapstock, manufacturing of
emulsifiers, packaging, and bulk shipment by tank, truck and tank car.
From this you can see that the waste water will represent a rather
complex mixture of emulsions, soaps, detergents, emulsifiers that
is constantly changing as plant operations change. The plant, when
built circa 19^0, had installed on the final outfall line a gravity
grease skim basin 20 feet wide x 20 feet long and of 7 feet depth.
Waste water after this skimming contained FOG levels ranging 500-
5000 mg/I and waste water flow varied from 150 to 350 gpm.
SYSTEM OBJECTIVES
Several alternate systems were reviewed before ultimate selection was
made. Objectives were two fold. (l) Water quality objective was an
FOG level of 50 mg/1 since the local sanitation district already had
an ordinance requiring 100 mg/1. It was established that reducing
the FOG would achieve proportionate reductions in BOD and S.S.
(2) Recovery of oil from the waste water of quality that would
product a saleable by product.
THE SYSTEM EMPLOYED
A block flow diagram of the system installed is depicted on Figure (l).
In figure (l) you will notice that all the plant waste water is dis-
charged into an existing basin which was originally installed when the
plant was built. Originally this water passed thru an under flow
weir and was discharged to the city manhole to the right of figure (l).
In the installation of the additional pre-treatment facilities this
basin was converted to become a pumping basin to feed the new gravity
circular oil-water separator shown in figure (l). This separator is a
1*0,000 gal. capacity and at a 500 gal./min. flow rate provides approximately
80 minutes of retention time. It has a top sweep boom and a bottom
sweep boom to handle both the floatable oil and any settleable solids
that might be delivered to the vessel. At the inlet of the pump sump,
we have a pH recorder controller and the ability to add acid to insure
that the pH throughout the system is kept below h. It is important that
any soaps that might be in the waste water be acidified before they get
to the oil water gravity separator, inasmuch as soap is miscible with
water and will not separate by gravity from water. Discharge from the
Rheem oil-water separator is then fed to a 3 vessel filter unit which is
installed to take the final oil reduction in the waste water down to
the acceptable limit of 100 mg/1 and our design target of 50 mg/1. After
passing through the filter unit the clear water discharge is directed
to the final portion of the old, original skim basin at which point
caustic soda is added to correct the pH back to the acceptable limits
of 1|.5 to 9 before discharge to the city sewer manhole.
260
-------
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261
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As you look at figure (l) you can see that what we have done is taken
sequential reductions in oil level across each part of the system.
The old skim basin which serves as a sump pump, in itself, still does
collect large quantities of free oil that on occasion come down from
the plant discharge. These are easily floatable and almost immediately
pop to the surface of the pump basin and remain there building a pad
of oil that is eventually skimmed and pumped back to the oil reclaim
operation. The initial reduction in oil content that occurs in this
basin is then followed by a further reduction in the oil water
gravity separator. The quiescent laminar flow that is available and
the 80 minute detention time, plus the fact that the water is an acid
condition, and that most of the soaps have been broken, allows for
natural gravity separation to occur between the oil and water phase.
Even so, the discharge from the oil water separator still has an oil
level completely unacceptable for discharge direct to the sewer.
These oil levels can range from 300 to 800 ppm at this point in the
system and a further reduction is required. This reduction is
accomplished through the filter units that are shown.
THE ADSORPTION FILTERS
Please refer to figure (2) which is a schematic diagram of the filters.
The deep bed filter has always been recognized as effective for removal
of solids from liquids. It has also been known that a granular type
filter medium used in a deep bed filter can effectively remove minute
quantities of oil from a water stream. However, the major draw back
for using a filtration method for the separation of oil from water is
that, until recently, there was no means by which the filter media
could be reused after it was once saturated with oil from the waste
water stream. Several years ago, a patent was issued for a method in
which the filter media bed was cleaned by introducing steam into the
media passing it through the bed in the direction counter-current to
the liquid flow. For the petroleum industry this method has been used
for cleaning deep bed filter media and has proved to be satisfactory.
An attempt was made to apply this steam cleaning process to the waste
water from an edible oil refinery and it was unsuccessful. The
problem encountered was that, after several backwashings using steam to
clean the media bed, the temperature of the steam started to
polymerize the residual oils that were on the filter media, and was
actually steam cooking the media to form a cemented mass which
eventually became impossible to remove. In order to over come this
problem, a method using chemical regeneration was developed and is
now part of the process used to regenerate the filter media.
Patents for this process have been applied for by GBK Enterprises,
developers of the process, have been approved but have not yet been
issued.
Referring to figure (2) let's go through the filtration and the back-
wash process. You can see that the waste water flows to the filter
from the top down, entering the filter from the left. Passes through
a distributor pipe, through the mixed bed media, all of which is
supported by a very dense media support bed. The water then flows
through the bottom distributor pipe and is discharged as clear water.
262
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PLANT AIR
WASTE
/A/
-DISTRIBUTOR
PIPE
". GRADED
• ' MEDIA <-"
SUPPORT
INLET OF
PUMP BASIN
1
PIPE
—00-
CL&AR WATER
D/SCHAKGZ
CLEAR WATER
BACK
FIG 2
GBK FILTER SCHEMATIC
263
PATENT APPLIED FOR BY
GBK EMTERPK/SŁ
AND APPROVED.
-------
As the filtering process continues, the oil is stripped from the
water and adsorbed on to the surface of the filter media with the
clear water passing through the "balance of the bed out to discharge.
The media at the top of the filter is the first to become coated
with adsorbed oil. As the filter run continues, the oil penetrates
deeper and deeper through the media bed. If the filtering is
continued long enough, eventually the oil will completely coat all
the media that is in the filter and will start to break through the
bottom of the media and pass out with the clear water discharge.
When this happens the filter is then acting as a coalescer and the
water discharge will be clear and bright, but with small droplets of
oil floating on the surface. This obviously is not the intended
method of filter operation, rather the filter run should be
interrupted at some point that retains the total adsorbed oil
within the filter bed. Normal design allows a 100$ safety margin
for this and we attempt to have the filter bed saturated with oil
only about 1/2 the way down. This then allows for variations in
oil content of the incoming waste water. At the end of the filter
run, the valves on the water inlet and the water outlet are shut off
and a fresh filter is put into service. The filter that has now
been saturated is put through a backwash cycle which is as follows:
Step 1: Drains the water from the filter from the top down
by opening the drain valve off to the inlet of the pump
basin and putting plant air on the top to force this water
through the bed out to the discharge.
Step 2: Shut off the drain from the bottom of the filter.
Open up the water valve on the bottom of the water tank
and on the bottom of the solvating chemical tank. Put
air pressure on the top of both tanks and displace both
the water and the solvating chemical into the filter
bed. This will cover up the top of the filter media.
The vent valve at the top is opened. Agitating air is
allowed to continue in via the pipe system and the water
tank to the bottom of the filter media coming up through
the media agitating the media with the solvating chemical for
a period of approximately 5 minutes.
Step 3: Shut off the agitating air, open the drain valve
at the bottom of the filter, put the plant air on the top
of the filter and force the mixture of oil and solvating
chemical down through the main valve to be discharged back
to the front end of the system where it can be acidified
for eventual recovery of the oil.
Step k: Open the vent valve at the top of the filter. Start
backwash using clear water rinse up through the filter bed
at the rate of approximately lU gals./min. per square foot.
Continue for a period of approximately 5 or 6 minutes. This
provides a clear rinsing backwash which removes all the
residual soap and solvating chemical discharging it to the
front end of the system. This rinse also removes any solid
material which might have been trapped in the filter media.
264
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The filler has now been regenerated; the media is clean and ready
to be placed back in service as the occasion demands.
Let's refer back to figure (l). Note that the backwash line from the
filter unit is discharged to the front end of the pump basin. Since
in our case the solvating chemical used during the backwashing cycle
has been caustic soda, we have formed a sodium soap in the filter
during the backwashing. When this sodium soap is drained and
placed to the front end of the system, the soap is then re-acidified
to break out whatever oil is in the soap. Most of this oil floats
out and is collected immediately at the surface of the pump basin.
Some of it will pass on through and be collected in the oil-water
gravity separator and only a very small amount of it will eventually
be circulated back to the filter. From this you can see the total
oil recovery is not only achievable but is done in a manner that
uses no chemicals that are not already used in the processing of
vegetable oils. There has been no contamination from polymers,
alum, lime, etc., all of which have been known to interfer with the
acidulation recovery process.
PERFORMANCE DATA
Please refer to Table (l). Table (l) shows the results of the system
operation with samples taken at the sampling points depicted in
Figure (l). We have the hexane extraction value on water samples
composited over a 2k hour period. Samples were collected on the
waste water from the pits, on the waste water from the gravity
clarifier and on the water from the GBK Filter. This data was
collected between July 18 and August 3, 1973 with a single filter
vessel installed. When the filter vessel required backwashing it
was taken off the line, put through the backwashing cycle and then
put back on the line. During this two (2) week test period the system
was completely manned 2k hours a day by Engineering personnel and
Engineering assistants. From the data you can see that the average
value for hexane extraction leaving the pump pit during this test
period was 1,325 mg/1. From the gravity clarifier the F.O.G. averaged
3lk mg/1 and from the filter unit F.O.G. average was 5*4 mg/1. The
average F.O.G. reduction between the pit and the outlet of the Rheem
Separator was 1,011 mg/1. The average F.O.G. reduction through the
filter unit was 260 mg/1. This works out to a 78$ reduction through
the gravity clarifier separator and a 22% reduction through the
filter unit. You will note that with the exception of July 26 all
values were under 100 mg/1 from the filter unit. The average being
5*t mg/1 which was very close to the original objective.
Please refer to Table II. Table II shows data collected during the
start-up of the three (3) filter vessel installation in December of
1973- Once again the values show hexane extractions in mg/1 for 2k
hour composite samples collected across the system in the various
sampling points as shown in Figure (l). Here with the whole system
in operation, but with plant operators manning the system, the
following data was generated. You can see that the average performance
during the period showed the water going to the clarifier at 1,336
mg/1. The water to the filters at k2k mg/1 if we exclude the rather
questionable data for the iHh and 15th, or a value of 73^ mg/1 if
we include the questionable lltth and 15th data. Water from the
265
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267
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filter unit showed a value of 52.6 when the questionable data of the
l4th and 15th was excluded and a value of 109 mg/1 if "the questionable
data was included.
SUMMARY
In summary, the system described achieves the original objectives
as well as additional benefits as follows:
(l) Oil recovery is made into a saleable by product without
contamination from flocculating agents, polymers, etc.
(2) Hexane extraction levels are reduced to below the legal
requirement of 100 mg/1 commonly set in municipal sewer
ordinances.
(3) Reductions in suspended solids, and B,O.D. almost
proportionate to the F.O.G. are achieved.
(k) Reductions of waste water surcharges between $10 and
$12,000 per month have been achieved, which amounts to
$120,000 - $144,000 per year savings.
(5) The recovered oil is currently selling at approximately
lkŁ/$. Oil recovery is expected to approximate about 1.5
million pounds per year with a value currently estimated
at $108,000 per year.
(6) Total gross savings will be between $228,000 and
$252,000 per year.
You will note that the data collected during the two (2) periods
is surprisingly close.
If you have any questions I will try to answer them.
268
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BIODEGEADABILITY OF FATTY OILS: A CASE STUDY**
by
Dr. Thomas K. Nedved* and Dr. C. Fred Gurnham*
The stated objective of the Federal Water Pollution Control Act Amend-
ments of 1972 (Public Law 92-500) was "to restore and maintain the
chemical, physical, and biological integrity of the Nation's waters."
The U.S. Environmental Protection Agency was charged by Congress to ad-
minister this Act, which included research and related programs, grants
for construction of treatment works, standards and enforcement, permits
and licenses, and other broad provisions.
One major U.S.E.P.A. task was to establish effluent limitations for
"point sources" of discharges, using the "best practicable control
technology currently available" by July 1, 1977, and the "best avail-
able technology economically achievable" by July 1, 1983. The ultimate
goal of the Congress was "that the discharge of pollutants into the
navigable waters be eliminated by 1985."
The regulations promulgated are required to "identify, in terms of
amounts of constituents and chemical, physical, and biological charac-
teristics of pollutants, the degree of effluent reduction attainable."
They are also to specify the factors taken into account in identifying
the two statutory technology levels noted above and in determining the
control measures applicable to point sources within specific industrial
categories.
One pollutant which has been the subject of a great deal of controversy
and concern has been what "Standard Methods" calls "oil and grease" or
simply "grease." Recommended Federal standards for this parameter in
the food processing and other industry categories have been or are
being developed. For example, in various subcategories of the meat
products industry, a 10 mg/1 limit is called for, even though this con-
centration is too low to measure with any reliability.
* Gurnham and Associates, Inc., Chicago, Illinois.
** This study was in part supported by Borden, Inc.
269
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The Federal Congress has determined that the U.S.E.P.A. should "encourage
cooperative activities by the States....(and)....the enactment of im-
proved and, so far as practicable, uniform State laws relating to the
prevention, reduction, and elimination of pollution...." One of the
more aggressive States, Illinois, in March, 1972, adopted perhaps the
most comprehensive effluent standards ever promulgated. The standards
prescribed limitations on the concentrations and properties of some 23
contaminants associated with wastewater and industrial waste discharges.
The effluent limit for oil, defined as "hexane solubles or equivalent,"
is 15 mg/1, and the public and food processing water supply limit for
oil is 0.1 mg/1. The latter limit is in the process of being elimina-
ted, by a proposed amendment to the regulations. These figures are
supplementary to the subjective general standard of "freedom from
visible oil."
Because sanitary districts and other municipal and industrial treatment
facilities must comply with Federal and State standards, additional
local ordinances have also been promulgated. For example, the Metro-
politan Sanitary District of Greater Chicago adopted a Sewage and Waste
Control Ordinance to "provide for the abatement and prevention of pollu-
tion by regulating and controlling the quantity and quality of sewage
and industrial wastes admitted to or discharged into the sewerage sys-
tems and waters under the jurisdiction of (the MSDGC)." The
maximum accepted concentration of "fats, oils or greases" (hexane
solubles) has been set at 100 mg/1.
The present paper is based on studies at three plants of Borden, Inc.,
located within the jurisdiction of the MSDGC. The Kilbourn Street ice
cream plant uses cream, condensed skim milk, sweetening sirups and
flavoring oils, gelatin, and nuts and fruits, to manufacture ice cream
and ice cream products. Wyler Foods Company manufactures chicken and
beef bouillon soup products and flavored sugar drink mixes. Cracker
Jack Company manufactures a well-known caramel corn-peanut product and
marshmallows. These plants were experiencing difficulties meeting the
MSDGC requirements of 100 mg/1.
The MSDGC position is that, because its secondary treated effluent on
occasion exceeds the Illinois Environmental Protection Agency oil limit
of 15 mg/1 for discharge to waterways, and because historic data indicate
an average removal of 85 percent through its treatment plants, a limit
of 100 mg/1 is necessary for wastes entering the sewer. This position,
although rational, is debatable, and the studies were planned to supply
supportive evidence.
BACKGROUND ON FATTY OILS
Many of the problems surrounding the whole subject of "oil and grease"
can be attributed to the following basic difficulties:
270
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(a) the non-specific nature of the "oil and grease"
standard analytical procedures;
(b) the large number and diverse nature of materials
detected by the standard procedures;
(c) the sensitivity and variability inherent in the
sampling and analytical procedures; and
(d) the complex mechanisms and interactions involved
in the removal of these materials from the waste-
water .
In addition to the above problems, which are characteristic of all oils
and greases, we believe that the true "oils" should be distinguishable
into two major fractions: (a) those of hydrocarbon structure, common-
ly of petroleum origin, characterized as "nonpolar," and (b) fatty oils,
which are glycerides or esters and their related compounds, normally
of animal or vegetable origin, and characterized as "polar." All oily
waste materials are objectionable when they exist in free form or as
floating films. The hydrocarbons are further objectionable, even when
dissolved or dispersed, because of their persistence and lack of bio-
degradability. The claim has been made, and is further documented by
these studies, that less stringent limitations would be realistic for
fatty oils than the conventional limits which were intended to control
refractory mineral oils.
Analytical Background
The analytical reference traditionally employed and cited in the water
pollution control field is "Standard Methods For The Examination of
Water and Wastewater," prepared and published jointly by the American
Public Health Association, the American Water Works Association, and
the Water Pollution Control Federation. This is currently in its 13th
edition (1971).
"Standard Methods" is divided into six parts; of interest in this study
are "Physical and Chemical Examination of Natural and Treated Waters in
the Absence of Gross Pollution" and "Physical, Chemical and Bioassay
Examination of Polluted Waters, Wastewaters, Effluents, Bottom Sedi-
ments, and Sludges." Waters included in the first category are surface
water, ground water, softened water, cooling or circulating water,
process water, boiler water, and boiler feed water. In the second cate-
gory are wastewaters of both domestic and industrial origin, treatment
plant effluents, and polluted waters.
The 10th edition (1955) of Standard Methods describes a direct extrac-
tion technique for determining "oil and grease" in natural and treated
waters in the absence of gross pollution, using a 1000-ml sample; and
271
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a Soxhlet extraction technique for determining "grease" in sewage,
treatment plant effluents, polluted waters, and industrial wastes,
using a sample containing from 50 to 150 mg of "grease." For indus-
trial wastes high in "grease," a significantly less accurate (tentative)
semi-wet extraction method was suggested. All three methods used
petroleum ether as the extracting solvent.
The llth edition (1960) added a section on Hydrocarbon and Fatty Matter
Content of Grease, and changed the extracting solvent to n-hexane (not
"hexanes") in the procedures for sewage and industrial wastes. Petro-
leum ether was retained as the extracting solvent in the water section.
No explanation was presented for these changes.
The 13th edition (1971) is essentially the same in respect to oils
and grease as the llth except that an alternative extraction solvent,
trichlorotrifluoroethane, can be used in all procedures. The semi-
wet extraction method is retained as a tentative procedure which
gives reproducible results but does not have the precision and accuracy
of the Soxhlet extraction technique.
The editors of Standard Methods caution that "In the determination of
grease, an absolute quantity of a specific substance is not measured.
Rather, groups of substances with similar physical characteristics
are determined quantitatively, based on their mutual solubility in
the solvent used. Grease may therefore be said to include fatty acids,
soaps, fats, waxes, oils and any other material which is extracted by
the solvent from an acidified sample and which is not volatilized
during evaporation of the solvent. It is important that this limita-
tion be clearly understood. Unlike some constituents - which represent
distinct chemical elements, ions, compounds or groups of compounds -
greases are in effect defined by the method used for their determina-
tion."
Continuing from Standard Methods:
"The methods presented here have been found suitable for biological
lipids and long-chain mineral hydrocarbons, when these occur at the
concentrations which are usual in domestic wastewaters. However,
samples which contain certain industrial wastes may require modifi-
cation of the methods (1,2) due to the presence of either excessive
concentrations of natural greases or synthetic or modified compounds
which are not well recovered by the standard procedures....The (Soxhlet
extraction) method is entirely empirical, and duplicate results can
be obtained only by strict adherence to all details. By definition,
any material recovered is called grease and any filtrable organic-
soluble substances, such as elemental sulfur and certain organic
dyes, will be extracted as grease. The rate and time of extraction
in the Soxhlet apparatus must be exactly as directed because of
varying solubilities of different greases in the solvents. In addi-
272
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tion, the length of time required for drying and cooling the extracted
grease cannot be varied. There may be a. gradual increase in weight,
presumably due to the absorption of oxygen, or a gradual loss of weight
due to volatilization."
Analytical Refinements
Lisanti (3) studied the effect of using petroleum ether for the oil and
grease determination procedure in the natural and treated waters section
of Standard Methods compared to the grease Soxhlet extraction procedure
in the polluted waters section using n-hexane. His investigations
indicated that the hexane-extractable material in dairy wastewaters is
approximately ten times the petroleum ether result. He suggested use
of the petroleum ether direct extraction procedure to determine the
"oil and grease" content of dairy wastes. Lisanti also ran treatabi-
lity studies on domestic sewage and dairy wastewaters and concluded
that the hexane-extractable matter contained in dairy wastes was
readily biodegradable and, therefore, should not be categorized as
oil and grease.
Several investigators have utilized more sophisticated analytical
techniques to define the characteristic fractions of sewage and to
measure changes during treatment. Farrington and Quinn (4) reported
on the petroleum hydrocarbon and fatty acid concentrations in effluents
from three secondary treatment plants in Rhode Island, using solvent
extraction and thin layer, gas, and column chromatography. The data
varied from 0.73 to 43.05 mg/1 (11.8 arithmetic average) for fatty
acids and from "non-detected" to 16.2 mg/1 (5.9 average) for petro-
leum hydrocarbons. The fatty acids were partitioned into 14 carbon-
atom/0 double-bond, 16/0, 16/1, 18/0, 18/1, and 18/2 acids, with
16/0, 18/0, and 18/1 predominating, which indicates oils and fats of
animal and vegetable origin.
Walther (5) at Stevenage, England, determined that 32 percent of the
total organic carbon in raw sewage was fatty acids and esters, by
reversed phase paper or column chromatography. He further showed that
99 percent of this material was removed by biological filtration
(trickling filter).
Loehr and de Navarra (6) studied grease removal at a contact stabili-
zation activated sludge plant at Topeka, Kansas, using wet extraction
and thin layer chromatography. These investigators determined that:
fatty acids were the dominant lipid class in influent wastewater,
followed by hydrocarbons, triglycerides, and compound lipids; no
alteration of lipid types was apparent in the primary clarifiers
although 45 percent of the total grease was removed; compound lipids,
a minor component of bacterial lipids, increased as the degree of
treatment increased; and hydrocarbons were the dominant lipid class
in effluent wastewater, followed by compound lipids and fatty acids
with an average observed grease removal of 84 percent and a maximum
273
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of 98 percent.
Oils in Sewage Treatment
With the continuing development of stricter standards and regulations
for the protection of our environment, many regulatory agencies have
imposed limits on the quantity of oil and grease which is permitted to
be discharged to a sewerage system or to a receiving water body. These
materials have been alleged to cause problems in sewers and sewage
treatment plants: by coagulating and plugging transmission lines and
pumps; by coating surfaces of tanks, diffuser plates, and by film form-
ation on air bubbles, thus reducing oxygen transfer efficiency; by
clogging mechanical equipment, thus increasing operation and mainten-
ance requirements; by forming grease balls on secondary settling tanks;
by combining with primary and waste activated sludge, causing difficul-
ties in settling, thickening, and dewatering operations; and by creat-
ing scums which interfere with anaerobic digester operation. They
also cause pollution problems in receiving streams by exerting BOD,
forming slicks, and otherwise interfering with both the natural biology
and the recreational usage of the waters.
Because the oil and grease test procedures are so non-specific, a more
rigorous way to determine what happens to fatty oils in a sewage treat-
ment plant would be to tag them with carbon-14 and to follow their fate.
This technique was beyond the scope of our studies, but we suggest its
merit to future investigators. We postulate that possible disposi-
tions of oily materials are:
(a) some hexane-extractable material (HEM) physically
separates from the wastewater and is removed during
primary treatment as skimmings or as settled solids;
(b) some HEM is adsorbed on the biological floe and is
removed with the waste activated sludge;
(c) some HEM is degraded to non-HEM or to C02 and H20;
(d) some HEM is converted to cellular mass, containing
both HEM and non-HEM;
(e) some HEM is created from non-HEM material; and
(f) some HEM passes through the treatment unchanged.
It is also reasonable and most important to point out that raw muni-
cipal wastewaters contain relatively non-biodegradable HEM in addition
to the hydrocarbons, such as complex aromatic compounds and chlorine,
sulfur, and nitrogen derivatives of hydrocarbons. These substances
in large part pass through the treatment system and register as polar
HEM in the effluent.
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OBJECTIVES OF PRESENT STUDY
In an attempt to shed additional light on some of the above issues,
investigations comparing the biodegradability and disposition of hexane-
extractable materials present in three industrial wastewaters and in
influent sewage of the MSDGC were conducted for Borden, Inc., by
Gurnham and Associates, Inc., with the assistance of Professor Roger
Minear, then of Illinois Institute of Technology.
The original objectives of these studies were:
(a) to use Standard Methods procedures to determine the hydro-
carbon fractions and the total hexane-extractable materials
present in MSDGC untreated sewage and in equalized indus-
trial wastewater samples. The industrial samples were
diluted to match the COD of the sewage and were fortified
with nutrient salts to match the COD:N:P ratios of the
MSDGC sewage.
(b) to trace the degradation and conversion of the HEM fractions
when subjected to biological treatment, using batch reactor
techniques;
(c) to compare the HEM and hydrocarbon concentrations and dis-
tributions in the treated effluents.
The above objectives were expanded in the third phase of the study to
include the following:
(d) to provide a measure of the accuracy and precision of the
analytical procedures and techniques by designing a mass-
balance experiment;
(e) to check potential areas of HEM and hydrocarbon loss (error)
and variability (sensitivity) in the analyses; and
(f) to more accurately differentiate between the phases of HEM
and hydrocarbon present initially, during treatment and
conversion, and in the treated effluent.
EXPERIMENTAL PROCEDURES
Grab samples of raw sewage and return activated sludge were obtained
from the MSDGC sewage treatment plant serving each particular indus-
trial facility under investigation. Composite samples of the indus-
trial wastewater discharges were obtained during the peak period of
clean-up operations to assure representation of the broadest spectrum
of wastes. Approximately one gallon of wastewater was obtained from
the plant discharge stream every 10 minutes over a 3-hour period.
275
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This program resulted in a 15-gallon composite sample representing the
greatest concentration and diversity of contaminants. For the purposes
of this study, such a sample was preferred to a truly proportional all-
day composite. At the analytical laboratories of the Environmental
Engineering Department at Illinois Institute of Technology, preliminary
analyses were conducted for chemical oxygen demand, nitrogen, and
phosphorus.
Three polyethylene cylindrical tanks of 40-liter capacity, with covers,
were used as reactors. Aeration and mixing was provided with fritted
glass sparger plates, using filtered laboratory compressed air. The
reactors were located in a walk-in cooler maintained at a temperature
of 20°C. The biological reactors were charged with sewage and with
diluted wastewaters either in combination with sewage or with a strong-
er concentration of diluted wastewater. The reactors were seeded with
activated sludge which had been aerated for 24 hours. Sampling and
analysis commenced immediately.
The reactors were sampled before sludge addition (seeding) and at
various intervals up to 48 hours. Each reactor mixed-liquor sample
was analyzed for total suspended solids, volatile suspended solids,
pH, and dissolved oxygen uptake rate. A 1200-ml portion was centri-
fuged and the supernatant liquor was analyzed for COD, 5-day biologi-
cal oxygen demand, HEM by liquid extraction procedure, and hydrocarbons
in the HEM. The centrifuged solids were filtered and analyzed for
HEM by Soxhlet extraction procedure, and for hydrocarbons. In the
third study, the centrifuged solids were filtered, washed with cold
hexane, and analyzed for HEM by Soxhlet extraction procedure, and
for hydrocarbons. The hexane wash also was analyzed for HEM and
hydrocarbons.
DISCUSSION OF RESULTS
The complete analytical results of this study are too voluminous to
be presented for publication, but the following observations are of
interest.
Hydrocarbon in Hexane-Extractable Material. The three sewage HEM's
contained 17, 34, and 18 percent hydrocarbon. Corresponding figures
for the food plant wastewaters were 14, 20, and 31 percent. The
averages of these figures, for sewage versus food wastewater, are
substantially identical: 23 and 22 percent.
Degradation of Non-hydrocarbon HEM. The non-hydrocarbon HEM in the
food wastewaters degraded to a greater extent than that in the
sewage, as follows: Ice cream plant, 94 percent versus 82 for the
sewage (the initial concentration was nearly double that of sewage,
but the final concentration was lower). Soup and soft drinks, sub-
stantially complete degradation in both plant waste and sewage.
276
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Snack foods, 77 percent versus 57, in 48 hours.
Degradation of Hydrocarbons, The hydrocarbon fraction degraded signi-
ficantly less rapidly than the non-hydrocarbon HEM, in all samples.
The hydrocarbon in food wastes degraded more rapidly than its counter-
part in sewage, as follows: Ice cream plant, 78 percent versus 61.
Soup and soft drinks, approximately the same as sewage, 57 percent
versus 54. Snack foods, 41 percent versus 23, in 48 hours.
HEM in Final Solids. A major portion of the HEM remaining in the mixed
liquor after treatment is associated with the solids: Sewage, 38 and
72 percent. Ice cream plant (2 tests), 49 and 50 percent. Soup and
soft drinks (2 tests), 60 and 63 percent. Snack foods, major portion
associated with the solids. A large part of the HEM associated with
the sludge solids is hydrocarbon, in comparison with the hydrocarbon
fraction in the raw waste; this reflects the slower degradation rate
of hydrocarbon: Sewage, variable, 35 and 25 percent in the two weak
sewages, almost 100 percent in the strong sample. Ice cream plant,
59 and 41 percent. Soup and soft drinks, almost 100 percent. Snack
foods, 48 percent.
The third,on snack food wastewaters, was run in more detail, leading
to the following additional results:
HEM as Fraction of COD. In the raw sewage sample, one percent of the
liquid-phase COD was HEM, compared to 0.06 percent in the snack food
raw waste.
Distribution of HEM and Hydrocarbon. Extremely small concentrations
of HEM and of hydrocarbons, approaching minimum detectable limits for
the respective analytical procedures, were found in the raw sample
filtrates, the centrifuged and filtered supernatants, and the hexane
washes except the 48-hour sample. These items can reasonably be
eliminated from the mass balance estimates. Large but random
differences occurred in the attempted mass balances, which therefore
require individual study and cannot be summarized at this time.
CONCLUSIONS
The data presented demonstrate that non-hydrocarbon hexane-extractable
material (HEM) of animal and vegetable origin, such as is present in
food processing wastewaters, is substantially removed when subjected
to biological treatment.
The HEM in each of the three food plant wastewaters studied is more
readily degraded than the HEM in municipal sewage.
The hydrocarbon fraction in the HEM degrades less readily than the
non-hydrocarbon fraction; but the food waste hydrocarbons degrade
more readily than the sewage hydrocarbons.
277
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A major part of the HEM remaining after treatment is associated with
the solids portion of the mixed liquor, strongly suggesting a con-
version of initial HEM to a biologically associated form. It was
not possible, however, to explore the distribution and interconversion
of HEM between nonviable solids (dead cells and other organic or in-
organic matter) and viable solids (live, functioning bacterial cells);
nor, in the latter, to distinguish between adsorbed and component HEM.
RECOMMENDATIONS
The Federal Environmental Protection Agency (U.S.E.P.A.) has taken the
position that a secondary sewage treatment plant can be expected to
achieve substantial removal of "compatible" pollutants, and it is
therefore not appropriate to require industrial users to achieve
"best practicable control technology currently available" for this
group of materials. U.S.E.P.A. has further stated (7) that fats, oils,
and greases of animal or vegetable origin may be classified as "com-
patible pollutants." In consideration of all of the above, the
following recommendations are proposed.
(a) The differentiation between non-hydrocarbon hexane-
extractable material, recognized to be a compatible
pollutant, and hydrocarbon hexane-extractable material,
a non-compatible pollutant, should be officially and
uniformly recognized by all concerned regulatory
agencies and determined by the procedures outlined
in the current edition of Standard Methods.
(b) State environmental protection agencies' water pollu-
tion regulations should be amended to interpret "oil"
contaminants as any free, floating, and visible oil
plus dissolved and suspended hydrocarbons as determined
by the Standard Methods procedure.
(c) Municipal regulatory agencies' regulations for dis-
charges to public sewer systems should be amended to
interpret "fats, oils, or greases" as those materials
determined by the Standard Methods hydrocarbon analysis.
ACKNOWLEDGEMENTS
The authors wish to acknowledge the laboratory assistance of Professor
Roger Minear (now at the University of Tennessee) and others of Illinois
Institute of Technology staff and graduate students. The project was
in part supported by Borden, Inc., and special assistance was provided
by Louis Janik, Corporate Environmental Coordinator.
278
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REFERENCES
1. Chanin, G., Chow, E. H., Alexander, R. B,, and Powers, J. F.
Scum analysis: a new solution to a difficult problem. Water
and Wastes Engg., 5_, No. 6, 49 (1968).
2. Taras, M. J., and Blum, K. A. Determination of emulsifying
oil in industrial wastewater, JWPCF, 40, R404 (1968).
3. Lisanti, A. F. Regulating the discharge of oils and greases
in dairy wastewater. Unpublished paper, April 1973.
4. Farrington, J. W., and Quinn, J. G. Petroleum hydrocarbons
and fatty acids in wastewater effluents. JWPCF, 45, 704
(1973).
5. Walter, L. Composition of sewage and sewage effluents - II.
Water & Sewage Works, 108, 478 (1961).
6. Loehr, R. C., and de Navarra, C.T., Jr. Grease removal at a
municipal treatment facility. JWPCF, 41, R142 (1969).
7. U. S. Environmental Protection Agency. Pretreatment of Pollu-
tants Introduced into Publicly Owned Treatment Works. Oct.
1973. (See also 40 CFR 128.121).
279
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ECONOMIC EFFECTS OF TREATING
FRUIT AND VEGETABLE PROCESSING LIQUID WASTE
by
Norman A. Olson*, Allen M. Katsuyama*, and Walter W, Rose*
ABSTRACT
A fruit and vegetable processing industry survey is the source of data
on liquid waste generation, treatment and costs, and the economic
impacts of waste management. Factors responsible for some of the
wide variations in wastewater flows and pollutional loads are identified.
The costs of processor-operated liquid waste treatment, of disposal to
land and to municipal treatment, and of in-plant pollution abatement are
reported. Large economies of scale are found in all of these data. The
pollution control costs (in addition to current costs) that can be borne by
processors are estimated. Estimates of the number of plants expected
to be closed because of pollution control costs are discussed. The
economic consequences of closing food processing plants are calculated.
Factors affecting the economic impacts of pollution control in the industry
are listed.
SUMMARY
This is a report on a survey of food processing liquid wastes generation,
treatment, and costs; and of the economic impacts of their control.
The surveyed industry (canned, frozen, pickled, and dehydrated fruits
and vegetables) is characterized by many small and some large plants,
short operating seasons per year, a variety of plant locations, and many
raw commodities.
The wastewater quantities and pollutional loads per unit of production
vary enormously among the industry's plants. Factors responsible for
the variations include the processed commodity, product style, percentage
of the plant capacity utilized, and the method of conveying the product
and solid wastes.
The costs of processor-operated liquid waste treatment and of disposal
to irrigation and to city treatment are highly variable. Changes in in-
plant operations to reduce water flows and abate pollution also vary
widely in cost.
Economies of scale are shown in all of the treatment and disposal data.
The additional pollution control costs that can be borne by processors
vary among plants and are inversely proportional to the plant's current
and expected control costs. The smaller the plant, the less favorable
is the comparison between feasible additional costs and the estimated
costs of liquid waste control by any method.
^National Canners Association, Western Research Laboratory,
Berkeley, California.
280
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Estimates of the number of plants expected to be closed because of
pollution control costs vary between 296 and 468, depending on the
required BOD and suspended solids removal.
Assuming that about 430 plants will close because of pollution control
costs, economic losses are estimated to include 27, 000 jobs on average
and 31,000 additional part-time jobs, outlets for 14, 000 farmers, and
$600 to $900 million in local economic activity.
Factors with inescapable effects on the economic impacts of pollution
control include plant size, commodity, product style, plant location,
and length of operating season.
INTRODUCTION
A questionnaire survey of liquid wastes generation and costs of the
economic impacts of their control undertaken by the National Canners
Association, American Frozen Food Institute, and cooperating processors
is the basis of this report. The survey covered canned, frozen, pickled,
and dehydrated fruits and vegetables. Data from more than 200 plants,
processing about one-third of the industry's production, are summarized.
The surveyed industry operated about 2200 plants and processed about
30 million tons of raw products in 1968 (1; references in parentheses).
Plants ranged in production from about 500 tons to 700, 000 tons of raw
commodity per year, and averaged about 14, 000 tons. An estimated two-
thirds of the plants processed 7500 tons or less. Average peak employ-
ment varied from 42 in the smallest plants to 4000 in the largest. About
two-thirds of the plants were within 0. 3 miles of a residential area and
amajority of them operated for six months or less per year.
The industry is thus characterized by a large number of small businesses;
it is highly competitive, operating on a relatively low profit margin. The
before tax profit on sales for canning and freezing was 1. 8% in the
1969-70 year and 48% of the industry's companies had no profit (2).
Because raw foods must be rendered clean and wholesome for human
consumption, and because food plants must be sanitary at all times,
large volumes of clean water are used and discharged as waste. Food
processing wastewaters are highly putrescible and cannot be stored for
later treatment. Unavoidable variations in wastewater strength and
volume cause treatment difficulties and the variations are many-fold
among months of the operating season and periods of the operating day.
Treatment facilities must therefore be designed for an unsteady-state
basis.
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RAW WASTE LOADS
Table 1 summarizes the quantities of wastewater, biochemical oxygen
demand (BOD) and suspended solids (SS) of untreated waste effluents
from processing plants. The reported waste loads varied many-fold
among plants processing the same commodity, confirming conclusions
from other studies. An example of this variability is shown in Figure 1,
distributions of the generation of BOD from peeled and from unpeeled
tomatoes. Peeling resulted in more BOD on average, but the two
distributions overlap broadly. Curves for other commodities and for
the generation of wastewater and of suspended solids have a similar
shape, with some plants generating several times as much waste as
the average. Data on several commodities have been analyzed to
identify some reasons for the variations.
NUMBER
OF
PLANTS
TOMATOES
PEELED
NOT PEELED
10
20 30
BOD, POUNDS/TON
40
50
Figure 1. Variability in the generation of BOD from, tomato processing.
Product style was related to the amount of water discharged in proces-
sing at least some commodities; for example, whole potatoes used
more water than other styles; pulped fruits used less than average;
sliced snap beans used more than other styles; and corn-on-cob used
less than cream style or whole kernel corn. Less water was discharged
per ton of product as the plant's capacity was more fully utilized or as
the proportion of water reused in the plant increased. More water was
discharged with increasing degrees of transportation of the product in
water between processing steps. Conveying solid waste in water instead
of "dry" increased the waste flow more often than not.
282
-------
Table 1. Discharged Wastewater and Pollutional Loads
Wastewater, 1000 gal/ton BOD, pounds/ton
Commodity
apple
apricot
asparagus
dry bean
snap bean
beet
berry
cauliflower
carrot
cherry
citrus
corn
grape
lima
pea
peach
pear
pepper
potato
pumpkin
sauerkraut
spinach, gr
squash
sweet potato
tomato
turnip
n
19
11
10
27
49
7
10
5
19
11
8
31
6
10
40
21
15
12
21
11
11
21
6
9
47
6
x
3. 1
4.9
6.7
9.6
4.8
4.2
3. 0
5. 8
3.9
4.9
2.3
1.7
3.0
6.8
4.7
3. 1
4.0
4.6
4.7
2.9
1.4
7.0
7. 4
4. 8
1. 7
7. 3
G min.
1.9
4. 1
5.8
6.8
4.0
3. 3
2.7
5.1
3.3
4. 1
2. 1
1.4
1.8
5. 8
4.0
2. 8
3.7
4.4
4.0
2. 1
.8
5.9
7.0
4.0
1. 3
6.6
n = sample size;
x = arithmetic average
G = geometric average
min. and max = calculated 95%
.2
1.1
1. 8
.9
1. 1
.8
.9
1.5
1.0
1. 3
.8
.4
.2
1.8
1.2
1. 1
1.6
1.6
1. 3
.4
. 1
1.7
3.2
.9
.3
2.5
max. n x G min. max.
17 9 14 13 6 30
14 8 48 44 18 105
18
44 6 75 61 15 239
14 15 16 9 1 72
13 5 36 28 4 179
7.5
18
11 8 28 25 8 72
13 5 20 15 2 94
5.6
5. 1 16 21 18 6 55
18
17
13 18 36 32 12 88
6.9 13 44 39 13 118
8.8 6 31 28 10 78
12
12 11 50 45 17 118
11 5 32 28 9 87
6.8
21 6 12 8 1 85
15
18
5. 2 23 9 7 2 28
18
SS, pounds /ton
n x G min. max.
6 3.0 3.1 1.0 9.1
14 5.4 4.1 .8 21
5 11 10 3.6 29
6 19 J3 1.8 86
10 9.7 9.0 4.0 20
10 12 10 2.6 41
8 7.5 6.5 2.0 21
8 7. 0 6. 1 1. 8 20
9 43 27 2.6 297
20 8.8 4.9 .3 72
limits
283
-------
The generation of BOD was influenced by product style. For example,
the BOD load from tomatoes was largely determined by the proportion
peeled. BOD generation declined as the proportion of pulped style in-
creased for several commodities. Transporting the product in water
was very highly correlated with BOD generation for snap beans and was
generally related for other commodities. Conveying solid residuals in
water increased BOD for some commodities. The generation of suspended
solids was influenced by about the same factors as those affecting BOD.
All of these effects of processing operations on waste generation were
expected.
An estimated 100 billion gallons of wastewater were discharged by all
the plants together. They reused about 200 billion and the amount that
would have been needed with no second use was about 300 billion. By
these estimates, the industry reused two-thirds of its water, thus
conserving an important resource but at the same time increasing the
pollutional strength of its waste streams.
The total amount of BOD generated (before any treatment except
screening) was estimated at about 800 million pounds and suspended
solids generation was about 500 million pounds. The concentration of
BOD in the wastewater before treatment was therefore 960 parts per
million (ppm). If there had been no reuse of water, the concentration
would have been 320 ppm. Corresponding figures for suspended solids
were 600 ppm actual and 200 ppm without reuse of water. Without reuse
the concentrations would be comparable to those of domestic wastewater.
COSTS OF LIQUID WASTE CONTROL
The costs of liquid waste control compiled from the survey are divided
among four systems:
1) treatment by lagoons, aeration, or other
systems for reducing the strength of the
wastewater;
2) disposal by irrigation, including pre-
irrigation treatment costs;
3) disposal to municipal sewage plants,
including pre-treatment costs; and
4) in-plant changes to reduce wastewater
flows or the generation of BOD or
suspended solids.
284
-------
Both existing systems and near-future systems for which cost and
efficiency estimates were available were compiled. Summarized
cost estimates are presented in Figures 2 through 5, necessarily
using different bases for different systems. The costs of "treatment"
depend critically on the percent of BOD and suspended solids removed
but removals are unknown, irrelevant, or only partly relevant for
irrigation and city disposal; both waste flow and BOD-SS reductions
are important in in-plant abatement systems. Except for the percent
removal in Figure 2, all the data in Figures 2 through 5 are plotted
against logarithmic scales to accommodate the wide range of numbers.
Treatment Costs
Estimated costs for plants operating their own treatment systems are
given in Figure 2, where the plant size is plotted against the percent
removal of BOD and suspended solids combined. Contour lines show
smoothed averaged costs per ton of raw product. These are geometric
averages (smaller than arithmetic averages would be because the data
are skewed). They are also conservative when compared to reductions
required by regulations because the percent removals entered here are
averages. A plant with a listed removal that coincided with a regulation
would be in violation half the time. Other evidence shows that the costs
of treatment rise more steeply going both upward and to the left than
indicated by the simplified analysis drawn on for Figure 2.
Larger plants had higher absolute costs but their increase was not
proportional to the increase in size, so that smaller plants had much
higher costs per ton of product. Economies of scale like this showed
up repeatedly in the survey.
As for nearly all the data in this survey, the costs of company operated
treatment plants were highly variable. Trends of the kind indicated by
the lines on Figure 2 were clear, but some plant costs were considerably
higher and others considerably lower than expected. The reasons for a
few of these differences are known, but in general they are unexplained.
Irrigation costs
Estimates of irrigation costs are in Figure 3, with wastewater flows
plotted against plant size in tons and contour lines for the cost in
dollars per raw ton. The water flows are conservative estimates of
the peak flows per month. Economies of scale are again large.
285
-------
PLANT SIZE, 1,000 TONS/YEAR
50
500
PERCENT
REMOVAL
OF
BOD & SS
100
90
80
70
60
50
40
Figure 2. Costs of company-operated treatment systems, $/ton.
Contour lines show dollars per ton of raw product; Geometric average
costs from (a) one-eighth of 1972 capital cost plus (b) operation and
maintenance costs.
Pre-treatment of the wastewater before irrigation varied from
screening only (most plants) to fairly elaborate treatment. The pre-
treatment costs were included as part of the irrigation costs since
they must have been required or else found advantageous to the
processor.
City Disposal Costs
City treatment plant disposal costs are estimated in Figure 4; waste-
water flows are plotted against plant size in tons, and dollar per ton
costs are shown by contour lines. Economies of scale are again
evident. The degrees of pre-treatment of wastewater disposed of at
municipal plants varied widely and the pre-treatment costs were
included with city costs for the same reason as for irrigation pre-
treatment.
286
-------
PEAK MILLION GALLONS/MONTH TO IRRIGATION
.5 5 50
PLANT
SIZE
1,000 TONS
PER
YEAR
500
200
100
I
50
20
10
5 d
I
2 r--
, J
s
.IMITS OF DATA*.:
iffitff
_/ 2
»_ . . . i ...
_ , i _ ...._
( i ! , i _
_...., i i I . . _
. . . . . i .«! ...._
\>'- ••'• :.'
, i , ! . .
jtsiL"1
ife
iitllllllMlllliP1-3
i i . .
j_ ( ! ( ! . . .
;;;;;ii!;;;;;ii!! ;;;-
;i!::::::;i!::::: ::
IllPf2-0
, 1 ....
. i
- i.l
Figure 3. Costs of irrigation disposal, $/ton.
Contour lines show dollars per ton of raw product: Geometric
average costs from (a) one-eighth of 1972 capital cost plus (b)
operation and maintenance costs.
In-plant Abatement Costs
The estimated costs of reducing wastewater flows and the quantities
of BOD and SS generated by changes in in-plant operation are
presented in two ways, in Figure 5 and Table 2. The variability
of these costs is shown in Figure 5, where degrees of abatement
are plotted against cost. The former is in units of a million gallons
wastewater plus 10, 000 pounds BOD and suspended solids
reduction. The costs were extremely variable, with differences
of 100-fold among plants of the same size to achieve the same degree
of abatement. Wide variability still remained when the 25% of plants
with the most extreme costs or degrees of abatement were omitted,
287
-------
resulting in the inner area of Figure 5 (which surrounds the plotted points
of the remaining plants). The costs of in-plant changes to abate liquid
waste are listed in Table 2 for a series of plant sizes and for different
degrees of wastewater and of BOD plus SS reductions. The figures in
the table are the average costs of from one to nine plants. They show
with some inconsistency economies of scale and increased costs for
increased returns. The in-plant abatement costs in this report are
incomplete. For example, many companies did not give the costs of
extensive water re-use systems.
MILLION GALLONS/YEAR TO MUNICIPAL TREATMENT
50
500
PLANT
SIZE
1,000 TONS
PER
YEAR
Figure 4. Costs of disposal to municipal treatment, $/ton.
Contour lines and squares show dollars per ton of raw product:
Geometric average costs from (a) one-eighth of 1972 capital costs
plus (b) operation and maintenance costs (both for pretreatment)
plus (c) sewer charges.
288
-------
COST,
$1000
PER
YEAR
OF THE
SAMPLE
PLANTS
.5 5 50 500 5000
DEGREE OF WASTE REDUCTION (WATER, BOD, AND SSI
Figure 5. Variability of costs of in-plant changes to reduce
p ollut ion.
The reported in-plant changes mostly reduced waste flows or BOD
and SS by small percentages, far too little to meet any likely
regulations.
Economies of scale were also conspicuous in the costs of specific
in«plant changes which reduce liquid effluents and pollutional loads.
For example, the capital costs of new peeling methods which reduce
BOD and SS generation increased only 2. 5-fold with a 10-fold increase
in plant size; and the capital costs of cooling towers went up 3-fold with
a 10-fold plant size increase.
289
-------
Table 2. Average Costs of In-Plant Pollution Abatement*
% discharge
flow reduced
0-10
More than 10
% BOD + SS
reduced
More
0-10 than 10
More
0-10 than 10
Plant 1-19
tons 50-99
per 100-169
year
170 +
(-.08)
. 14
. 11
. 08
,02
.92
.60
.06
.02
.42
41
28
12
04
10
. 82
.24
. 27
. 17
.22
; Tabled figures are dollars per ton of raw product
Current and Anticipated Costs
The estimated current costs of pollution control to the industry total
about $50 million per year and the total expected in the next few
years is about $90 million per year. These estimates include an
annual charge for capital (12. 5% of the capital costs expressed in 1972
dollars) and yearly operations and maintenance costs. They are
detailed as follows, in millions: for company-operated treatment, $12
current and $24 expected; for irrigation disposal, $14 current and $20
expected; for city treatment, $15 current and $27 expected; and for
in-plant controls, $8 recent and $19 expected. The capital costs (in
millions of 1972 dollars) for company operated treatment systems are
estimated at $50 current and $115 expected; for irrigation disposal, at
$69 current and $100 expected. The expected costs (generally for
1974-75) do not include the effects of new federal limitations.
290
-------
CRITICAL POLLUTION CONTROL COSTS
The survey determined what pollution control cost (in addition to
current expenditures) would cause a plant to go out of business,
assuming no price increase. This additional cost is named in this
report, the "critical pollution control cost". Its geometric average
was about $1 per ton of raw commodity processed and about two-thirds
of the critical costs were between $.25 and $3. 6 per ton. Twenty-
eight percent of the plants reported that they could stand no additional
control costs. The critical costs varied many-fold among plants of
the same size. Part of the reason for the variation was the level of
current and expected pollution control expenses. Plants with higher
current costs and those with higher expected costs both estimated
lower critical costs. The distribution plotted in Figure 6 is of critical
costs in dollars per ton versus the cumulative percent of plants.
CRITICAL COST, $/TON
,05
.5
50
PERCENT
OF
PLANTS
100
80
60
40
20
0
Figure 6. Distribution of critical costs of pollution control:
Percent of plants with given limiting cost or less.
291
-------
With data as variable as are the costs and critical cost estimates in
this study, conclusions based on averages cannot be precise. Accepting
$ 1 per raw ton as the critical pollution control cost anyway, Figures
2, 3, and 4 suggest how much abatement could be had at the breaking
point for plants of different sizes, ignoring current expenditures. To
operate their own treatment systems (Figure 2) plants processing 1000
tons per year could afford 40% BOD plus suspended solids removal at
the critical cost. Five thousand ton plants could afford about 60%
removal on average; 50, 000 ton plants, about 80%. Larger plants
and those with higher than average critical costs could afford higher
removals, assuming they were situated where building a treatment
system was feasible.
Irrigation (Figure 3) would cost more than $l/ton for plants up to
about the 50, 000 ton size. Even the smallest plants could presumably
afford irrigation if their critical cost were $3. 6/ton. However,
processors are restricted in the use of irrigation disposal in other
ways besides costs; for example, the soil type, topography, and
nature of the groundwater must be suitable. A large majority of the
states and territories impose controls on irrigation; some require
"secondary treatment" prior to land disposal and many have restrictions
on BOD, pH, solids, and/or other wastewater constituents. The costs
in Figure 3 are from plants that have found irrigation disposal
feasible; they do not reflect the costs that would be needed for
arbitrarily chosen plants.
City disposal costs (Figure 4) exceed $l/ton for many plants but do not
rise very much higher. Evidently most plants can afford city treatment
more readily than the other forms of disposal, especially at current
levels of sewer charges. However, city treatment is not available to
many processors and where municipal facilities are built new, expanded,
or upgraded, the pay-back policy for federal subsidies will increase
sewer charges. Some very large expected increases were reported.
Of the plants submitting data on current and announced future sewer
charges, one out of four expected triple or greater and half expected
double or greater costs.
Conclusions from the use of in-plant changes to abate pollution are
much more difficult to arrive at because of the extreme variability
of the data. Table 2 shows costs below $l/ton for in-plant control,
but only small quantities of pollutants were reduced on average.
Furthermore, the data do not adequately reflect the increasing costs
of abatement as the amount of it already achieved increases. Most of
the flow and strength reductions reported were small percentages of
292
-------
the totals. Costs may also be expected to go up when operating changes
for abating pollution require further modification to maintain sanitation
and meet noise control regulations.
ESTIMATED PLANT CLOSINGS
An earlier study for the EPA (3), based on highly generalized control
costs and levels, concluded that 100 plants in the industry would go out
of business because of pollution controls alone and that 300 more would
close down sooner than otherwise because of these costs. The following
estimates of the number of plants that will be closed because of pollution
control costs are based on data from the current industry survey.
The estimated numbers of plants of each size, given below, are
modifications of estimates in reference (1) to account for the smaller
segment of the industry in the current survey:
Plant size
1000 tons .51 Z 5 10 ZO 50 100 ZOO 500
Estim. no.
of plants 150 400 500 400 300 ZOO 100 70 ZO 10
Twenty-five percent of the plants were estimated to operate their own
treatment systems; 31% to use irrigation disposal; and 50% to discharge to
city treatment.
The number of closed plants that operate their own treatment systems was
estimated in two ways. Table 3 lists the number of plants whose estimated
treatment costs (Figure Z) would exceed their critical costs (Figure 6),
using the first method of estimation. Current expenditures were taken
into account.
293
-------
Table 3. Plants with Own Treatment Closed by Pollution Control
Costs (Method One).
Plant size
1000 tons
Re-
quired
percent
removal
of BOD
plus SS
60%
80
90
95
. 5
3
8
13
17
1
6
18
32
43
2
7
22
37
50
5
4
16
26
34
10
2
10
17
24
20 50 100 200 500 Total
2
622
10 4 3 1
15 7 4 1
25
85
144
197
The number of closed plants using the second method of estimation
included plants disposing of wastewater to irrigation and to city treat-
ment as well as plants with their own treatment systems; see Table 4.
By the second method of estimation about the same number of plants
with their own treatment would be closed down regardless of the
required percent removal of BOD and suspended solids. These
estimates were based on costs of treatment or disposal and an
assumed competitive cost incurred by large plants; they reflect
economies of scale but do not involve the subjective critical costs.
Table 4. Plants Closed by Pollution Control Costs (Method Two).
Plant size
1000 tons .5 1 2 5 10 20 50 100 200 500 Total
No. closed
treatment 21 42 41 25 14 5 2 1 151
No. closed
irrigation 7 12 12 7 4 2 1 1 46
No. closed
city 22 56 68 48 22 6 2 1 225
294
-------
The estimated total number of plants closed because of costs of
pollution controls is between 296 and 468, depending on the required
BOD and suspended solids removal. They are mostly small plants
and tend to be located in or near small communities. Assuming that
about 430 plants would be closed, the social impacts would include
the loss of about 27, 000 jobs on average and 31, 000 additional part-
time jobs; $140 million per year in wages; outlets for 14, 000 farmers
and $160 million in payments to farmers; and the generation of
between $600 and $900 million in local economic activity.
Some of the survey questionnaires asked if there was a possibility
that the plant would go out of business because of pollution control
costs. About one-third of the responses were "yes", including
affirmative answers from all sizes of plants, very small to very
large.
INDUSTRY SEGMENTS FOR EPA EFFLUENT GUIDELINES
In setting effluent guidelines under the 1972 Water Quality Act
Amendments, the Environmental Protection Agency (EPA) is to give
separate consideration to different segments of an industry according
to the degree of economic impact of the controls on each segment.
Plant age, commodity and style, plant size, plant location, and
operating season are discussed in this section as bases for such
segmentation of the fruit and vegetable processing industry.
Plant Age
Plant age is listed as a consideration in the 1972 Act and may have
significant effects, especially on the costs of abating pollution. The
data on plant ages in this survey have not been developed, partly
because most plants are a conglomeration of old and new equipment
regardless of the time they have been on the same site. In data
from the solid waste survey (1), plant age and location were clearly
correlated. The older the plant, the less was the distance to the
nearest residential development, no doubt because of the expansion
of cities, towns and suburbs. The effects of plant age would therefore
be associated with the effects of location, discussed below. Prepara-
tion procedures and equipment might also reflect plant age, but data
on this relationship have not been analyzed.
295
-------
Commodity and Style
That different commodities generate different quantities of wastewater
and pollutants has been recognized by EPA in previous and current
studies leading to effluent guides. The extremely wide variations among
plants processing the same commodity are equally significant. As
discussed in Section III, the product style was responsible for
differences in generated waste loads. Enough significance has been
found to show that the EPA must take style into account in order to
apply effluent limits without severely uneven economic impacts.
The quality of the raw product (for example, its proportion of culls
and the maturity and size of individual units) also affect the generation
of waste. These factors vary among regions, years, and days within
the same year; they are strongly influenced by weather. However, there
are no standard measures of raw product quality for many commodities
and an allowance for variability may have to substitute for the industry
segmentation based on these factors.
Preparation procedures and types of equipment also influence the
generation of wastes. Among the restrictions on processors in
choosing what procedures and equipment to use are sanitation require-
ments, product style and quality requirements, and cost requirements
for introducing changes. It seems doubtful that the EPA could prac-
tically or legally require the use of particular procedures or equipment,
but the effluent limits could differ depending on the existing situation
in different plants.
Plant Size
Plant size is a major factor in the economic impact of pollution controls.
This fact could be incorporated by not applying the EPA effluent limits
at all to plants below a particular size and by applying them on a sliding
scale to plants above this size. The plant size cut-off used in the fol-
lowing illustrative data is 7500 tons of raw product per year.
Justifications for the proposed cut-off include:
(A) Much of the record-keeping, checking and testing by
the EPA, state agencies, and small plants would be
eliminated; about two-thirds of the industry's plants
are smaller than 7500 tons per year. Only a small
fraction of the industry's generated wastes would be
excused from the EPA limits; these plants generate
296
-------
an estimated 12% of the industry's total BOD and
suspended solids and 14% of the liquid waste flow,
(B) The wastes from small plants would not be
released without control. About half the small
plants discharge to city treatment systems; nearly
all the rest have their own treatment, including
irrigation. Discharges would be subject to limita-
tions depending on the quality requirements of
receiving waters and on prohibitions against
creating a nuisance; these requirements would
over-ride EPA limits in any case.
(C) The smaller the plant, the higher are the relative
costs of irrigation, other company-operated treat-
ment, disposal to city systems, and in-plant pol-
lution abatement. The same effluent limit applied
to all plants would therefore affect small plants
more severely than large plants. This industry is
highly competitive and operates on a small profit
margin. The economic analyses in reference (3)
show clearly the problems created for small plants
by economies of scale: smaller plants would need
higher price increases than larger plants to achieve
the same level of pollution control; the price dif-
ferences would force the smaller plants out of
competition; and in addition, capital for expanded
controls would less often be available to smaller
plants.
(D) A large majority of the plants estimated to be closed
by pollution control costs are smaller than the cut-off
size. Even with the suggested cut-off in the application
of EPA limits, some of these small plants are expected
to close. Many of them are estimated to be unable to
meet the city disposal costs, for example, and the
justifications for cutting off EPA limits could also
apply to relieving small plants from re-paying the
federal grants used to build or improve city sewage
works. In addition, small plants would still be subject
to the alternative controls under (B) above.
297
-------
The justification for a sliding scale effluent limit for plants larger
than, say, 7500 tons of raw product per year are like those above
under (B), (C), and (D). Since the relative costs of pollution control
increase in inverse proportion to plant size, so will the impacts of
a constant EPA effluent limit.
Location
Liquid waste treatment requires land. For irrigation disposal, the
land must be not only available, but also suitable in several character-
istics. A city treatment plant must be within reasonable reach if this
method of disposal is to be used. For treatment or disposal at a
distance from the processing plant, the costs of rights of way, piping
and pumping must be financially bearable. Treatment and disposal
systems are affected by climate.
In addition to the land cost and climatic differentials associated with
plant location, the EPA should consider the relative effects of a closed
plant on its local economy. Processing plants may employ a large
percentage of the local work force and provide a vital outlet to local
farmers.
Operating Season
Treatment systems must be scaled for peak flows and organic loads;
city sewer charges may be based on peak demand. Processing nearly
all fruits and vegetables is highly seasonal. On average, the plants
in this survey operated during about eight months of the year and
processed 75% of their raw tonnage in four months. The operations
beyond the main seasonal items are commonly repacks of partly
processed commodities or other processing that generate small
effluents and waste loads. Even during the heavy season there are
many-fold fluctuations in day to day processing tonnage. The
proportion of the plant capacity utilized in processing a commodity
commonly averaged about 70 to 80%. The excess capacity is needed
for peak days during the season and for bumper crops that may occur
any year. The immediate availability of most raw commodities
depends on the weather and most of them cannot be stored to even out
the flow of deliveries to processing.
The differences in operating seasons among processing plants depend
on commodity, region, and other factors. The seasons for the same
commodity and same region vary from, year to year as do the
percentage utilizations of plant capacity. Because of variables like
these, the classifications of seasonality required by the EPA to avoid
disproportionate economic impacts on different plants may have to be
somewhat arbitrary.
298
-------
REFERENCES
1. Katsuyama, A.M., Olson, N.A., Quirk, R. L. , and Mercer, W. A. ,
1973. Solid Waste Management in the Food Processing Industry.
NCA under Contract No. PH 86-68-138, Environmental Protection
Agency. Distributed by National Technical Information Service,
PB-219 019.
2. Internal Revenue Service. Almanac of Business and Industrial
Financial Ratios (Issued annually).
3. Agri Division, Dunlap and Associates, Inc. 1971. Economic
Impact of Environmental Controls on the Fruit and Vegetable
Canning and Freezing Industries. For the Council on Environmental
Quality (P-585).
299
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INVESTIGATIONS OF FISHERY BYPRODUCTS UTILIZATION: RUMINANT
FEEDING AND FLY LARVA PROTEIN PRODUCTION*
by
John H. Green**, Susan Cuppett*** and Harry J. Eby****
INTRODUCTION
As technicians learn how to collect and handle waste solids or sludges,
methods must be found to dispose of this waste material. We feel that
endeavors to find uses for solid/sludge byproducts is one of the ways to
alleviate the economic burden of pollution abatement. This is particularly
true in the smaller, often seasonally operated food producing/processing
industries where expensive disposal equipment would be a great economic
burden.
Methods of solid/sludge disposal, such as incineration, landfill, composting,
and pyrolysis either present an economic burden to the smaller business
operator in terms of expensive equipment and hauling costs or, in the case
of the coastal based fisheries, are not always practical because of the
location of nearby high real estate valued resort areas or because of tide-
water land, rocky outcroppings or other terrestrial conditions which are not
usable as disposal sites. In the case of agronomic solid/sludge wastes, with
which part of this report is concerned, we are faced with the disposal of
massive amounts of carbohydrate material of low economic value and presenting
the potential of expensive equipment or treatment if physical or chemical
methods of disposal are to be considered. In addition, such disposal destroys
a natural resource.
Our objectives, therefore, are to find uses for solid/sludge wastes that are
practical, do not require expensive equipment, can be seasonally operated,
and are applicable to the characteristics of the waste under consideration.
This latter is most important. The utilization of the waste must take its
characteristics into consideration. Not every fishery, agronomic, or animal
waste is instantly a potential feed or fertilizer.
*Funded by the U. S. Department of Commerce, NOAA, NMFS, and by the U. S.
Department of Agriculture, ARS.
**College Park Fishery Products Technology Laboratory, National Marine
Fisheries Service, National Oceanic & Atmospheric Administration, U. S.
Department of Commerce, College Park, Maryland 20740
***Present address: Department of Animal Husbandry, Michigan State
University, East Lansing, Michigan.
****U. S. Department of Agriculture, Agricultural Research Service, Beltsville,
Maryland.
300
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In the case of fishery wastes, the amount and quality of the protein, the
amount of lipid material present, and the chemical and physical character-
istics of the waste must be considered. Making a fish meal out of a fishery
waste may not always be a wise choice. For example, fish solubles, a case
in point for this report, has the characteristic of being extremely hydroscopic.
Any attempt to dry this material to be sold in bulk as a fish meal would be
impractical because the material would regain water, cake, and eventually
undergo microbial decomposition. Hence, fish solubles are condensed to only
50% solids, acidified, and stored or shipped under anaerobic conditions in
steel tanks. Fish solubles are desired and used in small quantities in
poultry feeds because they contain an unknown growth factor (UGF). However,
its protein quality (amino acid profile) is not as good as that of the high-
quality parent product, fish meal (menhaden or other species), and the fat
content of fish solubles is too high to be considered for abundant uses in
animal feeds. The fisheries people have known about these and other charac-
teristics of fish solubles for many years, hence they are aware that making
a fish meal out of a fishery waste is not the answer to everything. Charac-
teristics of fish solubles are described in reports (A,8,9).
In the case of agronomic wastes, such as vegetable/fruit peelings or animal
wastes, we have collecting, hauling, and stabilization costs to consider
versus the costs of existing commodities, such as cereal feeds and chemical
fertilizers. In the situation dealt with in part of this report in which
animal wastes are being considered for reuse as animal feeds, we have health
considerations—the potential recycling and/or concentrating: animal diseases;
pesticides found in the original feeds or used in the animal barns; and
antibiotics used to treat the herds or flocks of animals.
Our endeavors as presented in this report and our report of the last confer-
ence (5) are efforts to find suitable byproduct utilization at a minimum of
processing. We have taken a biological, or rather a microbiological, route
in our quest for possible solutions. About our only innovation presented
here is that we have chosen alternatives which are perhaps a little different
than alternatives that have been considered in the past.
There is another consideration that this report takes into account. Most
organizations or industries are interested in finding solutions for their
particular pollution problems and uses for their recoverable byproducts.
This report presents research done on combinations of byproducts from dif-
ferent industries for the mutual benefit of both. We believe in the philos-
ophy that in this present day and age of modern technology and resulting
monstrous wastes to consider for disposal, the old concept of combining
wastes for mutual benefit has its merits. We have been looking for new uses
for the fishery byproduct, menhaden fish solubles, bearing in mind that what
uses we find for this slurry-like material could be applied to some other
fishery slurries and "wet" solid wastes. The primary market for fish
solubles is in poultry feeds and the demand for this application is based
301
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in part on the UGF. The protein of fish solubles contains all known natural
amino acids; however, the quantity of essential amino acids needed for
monogastric nutrition is only good, not excellent. Hence fish solubles does
not rate as a high-quality protein, like fish meal, to be used as primary
protein source in poultry feeding.
In addition, the residual fish oil of "stickwater" is condensed with the
production of fish solubles and results in an elevated fat content (approxi-
mately 10%) not desired in feeds. Poultry feeders and others use a limited
amount of fish oil as an energy source in feeds, but too much fish oil in
diets result in a fishy flavor in poultry or other meats (7). Hence the fat
content also limits the use of fish solubles.
The prices of fish meal and even fish solubles have recently been abnormally
high due to the world shortage of fish meal and soybean meal. However, prices
are beginning to return to normal which means that fish solubles will be
selling at a price nearly breakeven with its cost of production, storage,
and shipment. Should the UGF in fish solubles be identified, and poultry
experts and researchers have been trying to do this for years, the poultry
feed market for this byproduct will suffer. For this reason, we have been
looking for new uses for fish solubles, which might also be applicable to
other fishery wastes. Although this report is specific for the utilization
of certain fishery and agronomic byproducts, we hope the concepts presented
here will have application to other food processing wastes, to other
agronomic wastes, and perhaps even to other industrial or municipal wastes.
RUMINANT
One potential use for fish solubles, or other fishery wastes, investigated
by the animal nutritionists at our Laboratory was ruminant feeding. Cattle
can be fed a diet of cellulose and urea. However this is only a maintenance
diet which results in low yields of meat or milk. Also, a diet too high in
urea is toxic to the animal. Dr. W. M. Beeson's Animal Nutrition Group at
Purdue University has been exploring the efficiency of adding various
inexpensive protein substances as a "rumen stimulatory factor" or "urea
supplement" in high urea diets to increase urea utilization in cattle (10).
For this purpose, he has employed corn distillers dried solubles, dehydrated
alfalfa meal, and fish solubles. These protein-containing substances added
to high-urea diets stimulate the rumen microbes to better protein synthesis,
hence better utilization of the total nitrogen in the diet. Low to medium
quality protein will suffice because essential amino acids required in mono-
gastric nutrition are not an important factor in ruminant microbe nutrition.
The microbes in the rumen transform ingested materials into nutrients the
animal can absorb and use.
The use of fish solubles as a "rumen stimulatory factor" have been under con-
sideration by our Laboratory's Animal Nutrition.Group for over 3 years. We
also became impressed by the large volumes of caustic potato peel waste that
302
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would be generated by the new "dry" caustic peeling process. We had a wet,
acid, proteinaceous, high-fat slurry to find a use for, the vegetable and
fruit industries have a wet, caustic carbohydrate waste for which to find
uses. The combination of acid fish solubles with caustic vegetable/fruit
peel waste offered an opportunity to neutralize (pH) both products, yielding
a high salt (ionic) content of a carbohydrate-protein-fat material leading
to a potential supplement for ruminants. At least one researcher (6) had
explored "dry" caustic potato peel waste for cattle feed. We combined our
experimental efforts and explored fish solubles as a "rumen stimulatory factor"
both alone and in combination with "dry" caustic potato peel waste on lambs.
Our Laboratory's animal nutritionists decided to use fish solubles and a
mixture of fish solubles and caustic potato peel waste in ruminant liquid
feed supplements. Liquid feed supplements, a combination of vitamins, minerals,
high energy nutrients, sweeteners and nitrogen, are used nowadays in feed lots
or dairy herds to supplement alfalfa, grass and cereal feeds.
The first two attempts to run the experiment on lambs had certain mishaps.
A third experiment was reasonably successful in its completion. The results
for the third experiment are as follows:
When fish solubles was added to complete diets for growing lambs (solubles
equaled 0.3 to 0.6% of the complete ration), no significant differences were
observed in growth rates, feed efficiency, digestibility of dietary dry
matter, and protein or blood protein concentrations (third trial only). No
UGF activity could be demonstrated from either the fish solubles and/or potato
wastes. Based on these findings, it is concluded that fish solubles may be
fed in limited amounts to growing ruminants without detrimental effects. As
a substitute for non-protein nitrogen (i^._e. , urea) in ruminant diets, the cost
of solubles (on an equivalent nitrogen basis) is prohibitive. However, as a
means of utilizing wet fishery wastes, or other proteinaceous food processing
wastes, ruminant feeding might serve a useful purpose. Some potential revenue
from this use might help defray the costs of collection and transportation.
FLY LARVA PROTEIN PRODUCTION
In recent years the agricultural researchers at universities and the U. S.
Department of Agriculture sections who are involved in animal husbandry have
been experimenting with processes and methods to reuse animal droppings as
animal feeds. Their concern is that many animals, expecially ruminants, are
not efficient in their use of feeds and that animal droppings contain a high
amount of unutilized nutrient material—waste or natural resources.
The Agricultural Research Service under the U. S. Department of Agriculture
located at Beltsville, Maryland, is exploring several such feed/animal
dropping recycling methods. These include composting and direct drying and
pelletizing of the animal droppings. One of these methods is to grow fly
larva by inoculating animal droppings with fly eggs of the common housefly
303
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(Musca domestica L.). This is followed by several days of controlled
rotation, aeration, and larva growth. The fly larva are harvested, dried,
and ground into a protein, nutritious meal for animal feeds. The residue
of composted animal droppings might also serve as animal, probably ruminant,
feeds (1,2,3).
The advantage to this fly larva process is that the larva, which are grown
and removed from the media are nearly void of pesticides and antibiotics
which may have been in the animal droppings. This cuts down the possibility
of recycling these and other unwanted materials. The fly larva, when dried,
contains about 65% high-quality protein nutritionally equivalent to egg
albumen. It has been shown to be excellent in chicken diets. The yields
of fly larva protein are extremely low in terms of total raw product
processed. Fly larva production is really the side product of the agri-
cultural waste management system of composting animal waste. The revenue
from the sale of high-quality protein for animal diets might help underwrite
the cost of this pollution abatement. The sale of the residue, which is
about 96-97% of the compost after removing the fly larva, would help defray
other operational costs. Hopefully the total revenue would break even,
perhaps yield a slight profit for the processor.
The residue contains less concentration of nitrogen than the concentration
of nitrogen in the total compost prior to fly larva harvest. The residue has
some value as fertilizer or even as a feed. If the nitrogen content could
be increased, the residue would have even more value. In either fertilizer
or feeds, the price is primarily set by the nitrogen or protein content. As
materials undergo composting, the nitrogen and mineral concentrations increase
due to loss of carbon primarily as carbon dioxide and to loss of water bv
both metabolism and by evaporation through heat generated during composting.
The experimental composting is done bv adding weighed amounts of manure and
other ingredients to a cement mixer and initially rotating the cement mixer
to well blend all ingredients. The temperature of the compost can be
controlled by aeration and ventilation. Both factors are controlled in these
experiments by the amount of rotation of the cement mixers for aeration and
by electric fans blowing into and around the cement mixers for ventilation,
both are set on electric timers. After the raw manure has composted and
mellowed for one day, a known quantity of fly eggs prepared in an entomology
laboratory are inoculated into the compost mixture and allowed to develop
into fly larva for five days. The fly larva which are photophobic are
harvested by passing a thin layer of compost material on top of a screen which
is below a set of lights. The fly larva crawl thru the screen to avoid the
lights and are caught in pans below. The residue minus most of the fly larva
is collected for other potential uses such as fertilizer or ruminant feeds.
The harvested fly larva can be dried and ground into a meal, allowed to
develop into pupae then made into a meal, or allowed to develop into flies
and then prepared into a meal (1,2,3).
304
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The original objective for adding fish solubles to the raw animal waste was
to increase the nitrogen content of the residue and perhaps enhance composting.
It was believed from prior research that the maximum yields for fly larva
production had been approached (3). To our surprise, the growth of fly larva
remarkably improved. It became evident that the presence of 2-1/2 to 5%
fish solubles was affecting the growth of fly larva. The potential for
increasing fly larva protein yields was intriguing.
The composting of cow manure is not easy. The texture of the cow manure makes
it technically difficult; it acts like a pancake batter and gets anaerobic.
One author, H. J. Eby, solved this important detail by adding a "texturizer"
to break up the cow manure. In present experimental procedures, we are using
15% ground corn cobs. Future explorations could include both fiber and food
milling wastes, wastes from other food processing such as chopped pea vines,
peanut hulls, and, oh yes, shrimp and crab shell /waste. The latter, of course,
would contain nitrogen which might serve as an adjunct to the composting.
In our present experiment we are using 2.5% fish solubles which contains
approximately 5% nitrogen. We have plans to explore wet wastes from a variety
of fisheries as potential nitrogen sources.
For our first experimental approach we decided to explore the effects of fish
solubles on the composting of cow manure without the presence of induced fly
larva; therefore the fly egg inoculum was omitted. We felt it was important
to see if fish solubles was having a noticeable affect on composting. It must
be emphasized that what we really are doing is composting cow manure as part
of an animal waste management system. Fly larva production is only the icing
on the cake as a possible profitable revenue source. Smaller feed lots or
dairy farms may be content with just composting. The harvest mechanism for
fly larva is rather sophisticated. It would require both biological and
engineering or mechanical technical ability to maintain it.
The results of our first phase are shown in Figures 1 and 2. Figure 1 shows
the daily temperature readings of two composts. Readings were taken at 8 a.m.
and 4 p.m., each working day and about noon on some days during weekends. The
air temperature is the average of several readings taken outside of the corn-
poster (cement mixer). This particular experiment was done in February—and
we had one cold night in which the air temperature dropped in the housing
shed. It is normally assumed that the temperatures of the compost elevated
above room temperature are due to microbial action. The higher the temperature,
the more microbial activity, all other conditions being equal. Since the
amount of aeration and ventilation for both composters was the same, the
difference between control (no fish solubles) and experimental (2.5% fish
solubles) appears to be due to greater activity in the latter.
Figure 2 shows the total plate counts and the total yeast/mold counts for
mesophilic (35° C) and the thermophilic (55° C) microorganisms. In composting,
we are purposely holding down the compost temperature in these experiments
305
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Figure 1
Temperatures of the air and cow manure composts with and without
2.5$ menhaden fish solubles, but no fly larva production. Aeration
and ventilation controls (see text) were set the same as for fly
larva production (see Figure 3) and were intended to keep the compost
temperature below 45°C.
45-
40
35-
to 30
LU
Ul
IE
(9
LU
Q
25
20
TEMPERATURES OF COMPOST AND AIR
x x AIR
• • COMPOST, 25% FISH SOLUBLES
o o COMPOST, CONTROL
Of I
START
345
DAYS
306
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Figure 2
Mesophilic and thermophilic microMal counts on cow manure composts
with and without 2.5$ menhaden fish solubles, but no fly larva produc-
tion.
TOTAL AND YEAST/MOLD COUNTS: 35* AND 35* C
(NO FLY LARVA)
2 5% FISH SOLUBLES. TOTAL COUNT
o——o CONTROL TOTAL COUNT
25X FISH SOLUBLES T/M COUNT
a——-a CONTROL Y/W COUNT
307
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by control of aeration and ventilation. Hence, thermophilic microorganisms
did not make a great show. Another point should be emphasized. Yeast and
mold cells have a greater biomass than bacteria cells. Hence yeast/mold
cell counts that are lower than bacteria (total) counts do not always
mean negative activity from these fungi.
In our second phase of these experiments we have included a fly egg inoculum
for the production of fly larva. Results are shown in Figures 3 and 4.
Figure 3 shows the temperature curves for an experiment run in March. Again
the compost containing 2.5% fish solubles shows a higher temperature. In
general the temperature curves are higher than when fly egg inoculum was
omitted. The amount of controlled aeration and ventilation were the same as
for phase one. Hence there is evidence of greater biological activity when
fly larva inoculum is done. Figure 4 shows the microbial growth curves.
Our theory of more cell population from compost containing fish solubles
appears invalid. We have no rational explanation why the fish soluble total
counts are lower. Additional runs verify the same general observation: in
compost containing fish solubles, temperatures are higher, but microbial
counts lower.
The thing that is most evident is that the combination of microbial activity
and larva growth really speed up the bio-degradation of the cow manure. We
are now quite convinced that this combination might be purposely fostered
in large-scale or commercial composting as a means of speeding up the compost
process. If the fly larva were not harvested, then a rotary drier at the
end of the composter would dry the material for storage and shipment. The
drying would also kill the fly larva and pupa. In this situation we would
have a compost containing both single cell and fly larva protein which could
serve as an animal feed.
We are quite convinced that we have stumbled onto something interesting: the
fish solubles increases the fly larva growth and the fly larva increases the
bio-degradation of the composting action.
Our future plans are to pursue this aspect further and to explore other
fishery wastes. Our original objective is to provide a suitable means of
disposing of "wet" solid/sludge wastes from the fisheries. This would be
particularly advantageous for smaller and/or seasonally operated food (fish)
processing plants. However, we seem to have found a practical system for
efficient composting of cow, perhaps most animal manure.
SUMMARY
Our objectives are to find economical and practical methods to utilize wet
solid/sludge fishery wastes. This report describes combining menhaden fish
solubles, a byproduct of the fishmeal industry, with agronomic wastes to
form useful products.
308
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Figure 3
Temperatures of the air and cow manure composts with and without 2.5
menhaden fish solubles and with fly larva production. Aeration and
ventilation controls (see text) were designed to keep the compost
temperature from exceeding ^3-^5°C at which temperature fly larva
would begin to die.
45
40
35
tu
O
UJ
K
O
25
20
15
TEMPERATURES OF COMPOST AND AIR
x x AIR
• • COMPOST, 25% FISH SOLUBLES
o- o COMPOST, CONTROL
START EGG
3 4
DAYS
309
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Figure h-
Mesophilic and thermophilic microbial counts on cov manure composts
with and without 2.5$> menhaden fish solubles and with fly larva produc-
tion.
TOTAL AND YEAST/MOLD COUNTS: 35' AND 55'C
(WITH FLY LARV«)
2 SX FISH SOLUBLES TOTAL COUNT
o -o CONTROL TOTAL COUNT
2.5% FISH SOLUBLES Y/M COUNT
--o CONTROL. Y/M COUNT
310
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Ruminants fed a high urea diet usually require an inexpensive protein
source to function as a "urea supplement" or "rumen stimulatory factor" to
increase efficiency of nitrogen metabolism. Fish solubles and fish ,
solubles combined with "dry" caustic potato peel waste were explored for
this purpose using lambs as the test animal. Results indicated that fish
solubles could be used in sheep diets, but no benefits were noted and
this application of fish solubles would not be economically feasible.
However, other wet solid/slurry food (fish) processing wastes should be
tried for this utilization.
Fish solubles were used as a nitrogen supplement in experimental composting
of cow manure. Fly eggs were purposely inoculated into the composting cow
manure for the purpose of producing fly larva as a new source of protein
for poultry diets. It was shown that fish solubles was a benefit to the
cow manure composting with and without the presence of fly larva growth.
The fly larva growth in the cow manure compost contributes to the bio-
degradation and fish solubles appear to increase this activity. Further
exploration using other wet solid/sludge fishery wastes is planned.
Application of these methods of application of wet solid/slurry fishery
wastes may be of interest to other food processing industries.
311
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REFERENCES
1. Calvert, C. C., Martin, R. D., and Morgan, N. 0. House Fly Pupae as
Food for Poultry. J. Econ. Entomology 62^4) : 938-939 (1969).
2. Calvert, C. C., Morgan, N. 0., and Martin, R. D. House Fly Larvae:
Biodegradation of Hen Excreta to Useful Products. Poultry Sci. 49(2):
588-589 (1970).
3. Calvert, C. C., Morgan, N. 0., and Eby, H. J. Biodegraded Hen Manure
and Adult House Flies: Their Nutritional Value to the Growing Chick.
Proceedings of the International Symposium on Livestock Wastes published
by the American Society of Agricultural Engineers, St. Joseph, Michigan
49085, pp 319-320 (1971).
4. Cuppett, S. L. and Scares, J. H. The Metabolizable energy values and
digestibilities of menhaden fish meal, fish solubles and fish oil.
Poultry Sci. 51(6): 2078-2083 (1972).
5. Green, J. H., Paskell, S. L., Goldmintz, D., and Schisler, L. C. New
Methods Under Investigation for the Utilization of Fish Solubles, a
Fishery Byproduct, as a Means of Pollution Abatement. Food Processing
Waste Management published by the College of Agriculture and Life
Sciences, Cornell University, Ithaca, New York 14850, pp 51-68.
6. Heinemann, W. W. and Dyer, I. A. Nutritive Value of Potato Slurry for
Steers. Bulletin 757, Washington Agricultural Experiment Station,
College of Agriculture, Washington State University, Pullman, Washington
99163.
7. Miller, D. and Robisch, P. Comparative Effect of Herring, Menhaden, and
Safflower Oils on Broiler Tissues Fatty Acid Composition and Flavor.
Poultry Sci 48(6): 2146-2157 (1969).
8. Scares, Jr., J. H., Miller, D., and Ambrose, M. E. Chemical Composition
of Atlantic and Gulf Menhaden Fish Solubles. Feedstuffs ^2_(33) : 65,
71 (1970).
9. Scares, Jr., J. H., Miller, D., Cuppett, S. L., and Bauersfeld, Jr., P. E.
A Review of the Chemical and Nutritive Properties of Condensed Fish
Solubles. Fishery Bulletin J71(l): 255-265 (1973)
10. Velloso, L., Perry, T. W., Peterson, R. C., and Beeson, W. M. Effect
of Dehydrated Alfalfa Meal and of Fish Solubles on Growth and Nitrogen
and Energy Balance of Lambs and Beef Cattle Fed a High Urea Liquid
Supplement. J. Animal Sci. .32_(4) : 764-768 (1971).
312
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LIST OF PARTICIPANTS
R. E. BAKER
Food Industries Research Engineering, Inc.
33 South Second Avenue
Yakima, WA
H. BARNETT
National Marine Fisheries Service
2725 Montlake Boulevard, East
Seattle, WA
M. I. BEACH
N-CON Systems Co., Inc.
308 Main Street
New Rochelle, NY
J. L. BOMBEN
USDA - Western Regional Research Center
Albany, CA
R. D. BOTTEL
Tillie Lewis Foods
Drawer J
Stockton, CA
A. BOYDEN
Spreckels Sugar Division
Amstar Corporation
Manteca, CA
J. R. BOYDSTON
Industrial Wastes Branch-EPA
200 SW 35th Street
Corvallis, OR
D. BROOKS
National Canners Association
1600 South Jackson Street
Seattle, WA
W. R. BROSE
Green Giant Co.
232 Regency Road
Le Sueur, MN
S. C. BROWN
Envirotech Corporation
420 Peninsula Avenue
San Mateo, CA
R. L. BROWNSTEIN
Phillips, Barratt, Hillier,
Jones & Partners
2236 West 12th Avenue
Vancouver, B.C. CANADA
N. S. BUELL
Del Monte Corporation
2600 Seventh Street
Berkeley, CA
J. BUHLERT
University of California
Department of Food Science
and Technology
Davis, CA
D. E. BURNS
EIMCO BSP Division
Envirotech Corporation
P.O. Box 300
Salt Lake City, UT
A. A. CARLO IS
Heat and Control, Inc.
225 Shaw Road
South San Francisco, CA
W. A. CARNES
Engineering-Science
150 N. Santa Anita
Arcadia, CA
J. A. CHITTENDEN
Iowa Beef Packers, Inc.
Dakota City, NE
H. S. CHRISTIANSEN
Carnation Company
5045 Wilshire Boulevard
Los Angeles, CA
F. CLAGGETT
Environment Canada
3rd Floor - 1090 W. Pender Street
Vancouver, B.C. CANADA
313
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J. D. CLISE
Department of Health and Mental Hygiene
State of Maryland
Baltimore, MD
M. W. COCHRANE
Industrial Wastes Branch-EPA
200 SW 35th Street
Corvallis, OR
J. E. COGAR
Stayton Canning Company Co-op
4755 Brooklake Road N.E.
Salem, OR
C. W. COOKE, JR.
E. I. DuPont
ICD, Willow Bank
Wilmington, DE
G. M. COOKE
Department of Viticulture and Enology
University of California
Davis, CA
E. A. CROSBY
National Canners Association
1133 20th Street, N.W.
Washington, DC
D. L. CUMMINGS
Tri-Aid Sciences, Inc.
161 Norris Drive
Rochester, NY
F. J. CYGAN
Dorr-Oliver, Inc.
66 Jack London Square
Oakland, CA
B. L. DAMARON
Poultry Science Department
University of Florida
Gainesville, FL
P. DE FALCO, JR.
EPA - Region IX
San Francisco, CA
M. DICK
EPA
RD-679, Waterside Mall
Washington, DC
J. C. DIETZ
Clark, Dietz and Associates,
Engineering Inc.
211 N. Race Street
Urbana, IL
J. DOLAN
Chef-Reddy Foods Corporation
P.O. Box 607
Othello, WA
K. A. DOSTAL
Industrial Wastes Branch-EPA
200 SW 35th Street
Corvallis, OR
W. DOUCETT
California Canners & Growers
182 S. Fair Oaks
Sunnyvale, CA
R. H. DOUGHERTY
Horticultural Department
Purdue University
W. Lafayette, IN
C. B. DULL
James Allen & Sons
P.O. Box 8329
Stockton, CA
J. DYER
Consulting Engineer
13245 - 40th Street, N.E.
Seattle, WA
H. J. EBY
USDA-ARS
9749 Goodluck Road
Seabrook, MD
R. EDWARDS
Farmland Foods, Inc.
10700 West Waveland Avenue
Franklin Park, IL
314
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T. E. ELBERT
Environmental Pollution Control Division
George A. Hormel & Co.
1415 Grand Avenue
Wausau, WI
E. E. ERICKSON
North Star Research Institute
3100 38th Avenue, South
Minneapolis, MN
J. W. FARQUHAR
American Frozen Food Institute
919 18th Street, N.W.
Washington, B.C.
R. V. FETTERLY
Diebold Inc. - Lamson Division
Syracuse, NY
J. W. FIELD
U.S. EPA - Region VI
1600 Patterson Street
Dallas, TX
B. A. FILICE
California Canners & Growers
San Francisco, CA
G. E. GLANN
EPCO - Division, Geo. A. Hormel & Co.
P.O. Box 800
Austin, MN
D. H. FURUKAWA
Fluid Sciences Division
Universal Oil Prod. Co.
8133 Aero Drive
San Diego, CA
J. D. GALLUP
Environmental Protection Agency
RD-679, Waterside Mall
Washington, D.C.
J. R. GEISMAN
Ohio State University
2001 Fyffe Ct.
Columbus, OH
R. E. GERHARD
George A. Hormel & Co.
P.O. Box 800
Austin, MN
H. GOEHRING
Goehring Meat Inc.
P.O. Box 147
Lodi, CA
M. GOLDMAN
Gentry Int. Inc.
Pacheco Pass Road
Gilroy, CA
M. E. GORDON
Daylin Laboratories Inc.
2800 Jewel Avenue
Los Angeles, CA
J. H. GREEN
National Marine Fisheries Service
NOAA
College Park, MD
B. GREENOUGH
Lockheed Missiles & Space Corporation
P.O. Box 504
Sunnyvale, CA
A. GRINKEVICH
Hunt - Wesson Foods, Inc.
Fullerton, CA
D. A. GUBSER
Star-Kist Foods, Inc.
582 Tuna Street
Terminal Island, CA
C. F. GURNHAM
Gurnham and Associates, Inc.
223 West Jackson Blvd.
Chicago, IL
T. R. HAMPTON
Gellehon, Schemmer Associates
12100 W. Center Road, Ste. 520
Omaha, NE
315
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M. R. HART
Western Regional Research Center-USDA
800 Buchanan Street
Albany, NY
W. L. HASLAM
Lamar Haslam Associates
5344 Bunker Court
Fair Oaks, CA
C. R. HAVIGHORST
Food Engineering Magazine
200 Mockingbird Circle
Santa Rosa, CA
L. HAWKINS
Environmental Science & Engineering, Inc.
Gainesville, FL
J. E. HELM
Spiegl Foods Inc.
P.O. Box 1491
Salinas, CA
DANIEL KOBE
CH2M Hill
360 Pine Street
San Francisco, CA
R. W. HUIBREGTSE
The Larson Company
P.O. Box 1127
Green Bay, WI
D. E. JAMES
General Foods Corporation
250 North Street
White Plains, NY
W. J. JEWELL
Cornell University
202 Riley Robb
Ithaca, NY
M. E. JOYCE
Industrial Wastes Branch-EPA
200 SW 35th Street
Corvallis, OR
A. M. KATSUYAMA
National Canners Association
1950 Sixth Street
Berkeley, CA
D. F. KINCANNON
Oklahoma State University
Stillwater, OK
J. M. KROCHTA
Western Regional Research Center
USDA
Berkeley, CA
H. N. KUMMER
Western States Meat Packers Association
P.O. Box 159
Hillsboro, OR
K. La CONDE
SCS Engineers
4014 Long Beach Blvd.
Long Beach, CA
D. LANGHOFF
Tri Valley Growers
3200 East 8 Mile Road
Stockton, CA
P. F. LEAVITT
Gerber Products Company
445 State Street
Fremont, ME
J. W. LEE
CH2M Hill
1600 SW Western Blvd.
Corvallis, OR
G. W. LINDSAY
EPA-Environment Canada
P.O. Box 2406
Halifax, Nova Scotia, CANADA
P. LUTHI
Artichoke Industries, Inc.
11599 Walsh Street
Castroville, CA
316
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S. C. MACAULAY
State Water Resources Control Board
1416 Ninth Street
Sacramento, CA
D. MacGREGOR
Canada Agriculture
Food Processing Research Station
Summerland, B.C. CANADA
R. MANVILLE
GBK Enterprises, Inc.
717 Dunn Way
Placenta, CA
A. F. MAULDIN
Domingue, Szabo, & Associates
P.O. Box 52115
Lafayette, LA
VERLIS E. MILLER
National Fruit Products Co., Inc.
P.O. Box 609
Winchester, VA
G. R. MINTON
URS/Hill, Ingram, Chase & Co.
2909 Third Avenue
Seattle, WA
A. J. MONTA
Welch Foods, Inc.
Westfield, NY
J. S. MOSER
Pacific Coast Producers
P.O. Box 467
Walnut Creek, CA
J. F. MUELLER
URS Research Co.
155 Bovet Road
San Mateo, CA
A. C. McCULLY
Agripac Inc.
P.O. Box 1266
Eugene, OR
W. R. McGILL
Canada Packers Co. Ltd.
95 St. Clair Ave., W.
Toronto, Ontario, CANADA
E. J. NORRENA
MacLaren Atlantic Ltd.
Ste. 402, Scotia Square
5251 Duke Street
Halifax, Nova Scotia, CANADA
T. M. OLCOTT
Lockheed Missiles & Space Corporation
P.O. Box 504
Sunnyvale, CA
N. A. OLSON
National Canners Association
1950 Sixth Strert
Berkeley, CA
G. R. PANKEY
Neptune Micro-Floe
P.O. Box 612
Corvallis, OR
R. C. PEARL
Department of Food Science
University of California
109 Curess Hall
Davis, CA
G. PERKINS
Artichoke Industries Inc.
11599 Walsh Street
Castroville, CA
J. POD10
Artichoke Industries Inc.
11599 Walsh Street
Castroville, CA
J. W. RALLS
National Canners Association
1950 Sixth Street
Berkeley, CA
D. H. RASMUSSEN
Jacobs Engineering Co.
837 S. Fair Oaks Avenue
Pasadena, CA
317
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M. J. RIDDLE
Environment Canada
Water Pollution Control Directorate
Ottawa, CANADA
K. M. RIES
The Greyhound Corporation
Phoenix, AZ
S. ROBBINS
EIMCO Division of Envirotech
420 Peninsula Avenue
San Mateo, CA
C. D. ROBERTS
Contadina Foods Inc.
P.O. Box 29
Woodland, CA
W. W. ROSE
National Canners Association
1950 6th Street
Berkeley, CA
R. F. ROSKOPF
Rieke, Carroll, Muller Associates, Inc.
1011 First Street
Hopkins, MN
M. RUDD
American Pollution Prevention Co.
789 Grain Exchange Bldg.
Minneapolis, MN
P. RUSSELL
Harnish & Lookup Associates
615 Mason Street
Newark, NJ
W. M. RYAN
Industrial Sanitation Consultant
P.O. Box 1037
Danville, CA
J. A. SANTROCH
Industrial Wastes Branch-EPA
200 SW 35th Street
Corvallis, OR
Inc.
J. F. SCAIEF
Industrial Wastes Branch-EPA
200 SW 35th Street
Corvallis, OR
R. E. SCHEIBLE
Kraft Foods
500 Peshtigo St.
Chicago, IL
C. J. SCHMIDT
SCS Engineers
401A Long Beach Blvd.
Long Beach, CA
T. G. SHEA
W. E. Gates & Associates, Inc.
Fairfax, VA
C. A. SIGLER
Libby, McNeil, & Libby
444 W. California Street
Sunnyvale, CA
BJORN SIVIK
University of Lund
Division of Food Processing
P.O. Box 50
S-230 53 Alnarp, SWEDEN
E. SMITH
Contadina Foods
2906 Santa Fe
Riverbank, CA
R. G. SMITH
Metcalf & Eddy,
Palo Alto, CA
- Carnation Co.
Inc.
T. J. SMITH
Magnuson Engineers Inc.
P.O. Box 5846
San Jose, CA
M. SODERQUIST
Environmental Associates Inc.
P.O. Box 277
Corvallis, OR
318
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P. W. SOPER
Gov't. of B.C.
Pollution Control Branch
1106 Cook Street
Victoria, B.C. CANADA
P. M. STANLEY
Safeway Stores Inc.
425 Madison Street
Oakland, CA
J. L. STEIN
Anheuser-Busch, Inc.
Engineering Dept., Bid. 3
721 Pestalbzzi Street
St. Louis, MO
R. W. STERNBERG
George D. Clayton & Associates
25711 Southfield Road
Southfield, MI
H. E. STONE
Del Monte Corporation
215 Fremont Street
San Francisco, CA
E. J. STRUZESKI, JR.
EPA - NFIC - Denver
Box 25227, Bldg. 53
Denver Federal Center
Denver, CO
A. J. SZABO
Domingue, Szabo, & Associates
P.O. Box 52115
Lafayette, LA
L. TABER
Canners League of California
Sacramento, CA
A. TARQUIN
University of Texas
Department of Civil Engineering
El Paso, TX
H. C. TEEL
CH2M Hill
360 Pine Street
San Francisco, CA
H. W. THOMPSON
Industrial Wastes Branch-EPA
200 SW 35th Street
Corvallis, OR
I. M. TOOKOS
University of California
2646 Dwight Way, Apt. 4
Berkeley, CA
W. TURLEY
General Foods Corporation
708 10th Street
Waseca, MN
G. H. UPHOLT
Canners League of California
1007 L Street
Sacramento, CA
J. VILLAMERE
Environment Canada
1090 W. Fender Street
Vancouver, B.C. CANADA
M. Von TREBA
Phillips, Barratt, Hillier, Jones
and Partners
2236 West 12th Avenue
Vancouver, B.C. CANADA
J. F. H. WALKER
Arthur G. McKee & Co.
10 S. Riverside Plaza
Chicago, IL
DR. E. WEISBERG
Jacobs Engineering Co.
837 South Fair Oaks Avenue
Pasadena, CA
W. J. WELLS, JR.
Bell, Galyardt, Wells
5634 S. 85th Street
Omaha, NE
D. WESTCOT
State Water Resources Control Board
1416 Ninth Street
Sacramento, CA
319
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R. T. WILLIAMS
East Bay Municipal Utility District
Oakland, CA
G. E. WILSON
Eutek Engineering
1231 McClaren Drive
Carmichael, CA
J. L. WITHEROW
Industrial Wastes Branch-EPA
200 SW 35th Street
Corvallis, OR
K. W. WONG
Gerber Product Co.
9401 San Leandro Blvd.
Oakland, CA
I. J. WRIGHT
B&A Engineers, Inc.
240 2nd Street
San Francisco, CA
S. C. YIN
EPA-Treatment & Control Branch
Ada, OK
G. M. ZIEGLER, JR.
USDA-ARS-Southern Regional Research Center
P.O. Box 19687
New Orleans, LA
320
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SELECTED WATER
RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
W
Proceedings Fifth National Symposium on Food
Processing Wastes
Pacific NW Environmental Research Laboratory
National Canners Association
Canners League of California
Industrial Wastes Branch
Pacific NW Environmental Research Laboratory
Environmental Protection Agency
Corvallis, OR 97330
Environmental Protection Agency report number EPA-660/2-74-058
June 1974
The Proceedings contains copies of 19 of the 20 papers presented at
the two and one-half day symposium.
Typical papers include: wastewater characterization for the specialty
food industry; treatment of shrimp processing, rum distillery, vegetable oil
refinery, and meat processing wastewaters; process modifications for cleaning
and peeling of tomatoes, and blanching and cooling of vegetables; by-product
recovery from meat processing wastes, fish processing wastes, and waste
activated sludge; wastewater reuse in poultry processing; and economics
of treating fruit and vegetable processing wastewaters.
industrial Wastes, *Food Processing Industry, *Treatment, By-products
By-product Recovery, Process Modification, Food Processing Waste Charac-
terization and Treatment
Send To.
WATER RESOURCES SCIENTIFIC INFORMATION CENTER
U.S. DEPARTMENT OF THE INTERIOR
WASHINGTON. D.C. 2O24O
Kenneth A. Dostal
EPA, NERC-Corvallis
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