EPA-600/2-76-214
September 1976
Environmental Protection Technology Series
WORKSHOP ON
IN-PLANT WASTE REDUCTION
IN THE MEAT INDUSTRY
industrial Environmeutal Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
-------
RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, 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.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
-------
EPA-600/2-76-214
September 1976
WORKSHOP ON IN-PLANT WASTE REDUCTION IN THE MEAT INDUSTRY
Held at
University of Wisconsin, Madison
December 13-14, 1973
Compiled by
Jack L. Witherow
James F. Scaief
Food & Wood Products Branch
Industrial Environmental Research Laboratory—Cincinnati
Corvallis Field Station
Con/all is, Oregon 97330
U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY
CINCINNATI, OHIO 45268
-------
DISCLAIMER
This report has been reviewed by the Industrial Environmental Research
Laboratory - Cincinnati, U.S. Environmental Protection Agency, and approved for
publication. Mention of trade names or commercial products does not constitute
endorsement or recommendation for use.
11
-------
FOREWORD
When energy and material resources are extracted, pro-
cessed, converted, and used, the related pollutional impacts
on our environment and even on our health often require that
new and increasingly more efficient pollution control methods
be used. The Industrial Environmental Research Laboratory -
Cincinnati (lERL-Ci) assists in developing and demonstrating
new and improved methodologies that will meet these needs both
efficiently and economically.
"Workshop on In-Plant Waste Reduction in the Meat Industry"
summarizes the experiences and needs of the meat industry in
terms of in-plant waste reduction. This document is for use by
industry and government as supportive information for application
of effective in-plant waste management or development for research
projects. For further information on the subject contact the Food
and Wood Products Branch, Industrial Environmental Research Lab-
oratory—Cincinnati.
This report resulted from a workshop on in-plant control of
wastes in the meat industry. The workshop was held on the Uni-
versity of Wisconsin Campus and was attended by food waste
specialists. The material presented and discussed there has been
organized and presented herein.
David G. Stephan
Director
Industrial Environmental Research Laboratory
Cincinnati
iii
-------
ABSTRACT
Presented are the proceedings of a workshop on in-plant waste
reduction in the meat industry. Forty-five participants from industry,
government, and private firms exchanged ideas and experiences on waste
reduction during the two-day session. Topics covered were: pens, blood
conservation and processing, hide and hair removal and processing,
eviscerating and edible offal processing, paunch and viscera handling,
rendering and plant clean-up operations. Case histories are presented
on water conservation in a meat packing plant and in a hog processing
plant.
IV
-------
TABLE OF CONTENTS
Section Page
I. Conclusions 1
II. Introduction 3
III. Pens 6
IV. Blood Conservation 9
V. Blood Processing 13
VI. Aspects of Pollution from the Brine Curing 18
Operation
VII. Hair Removal and Processing 30
VIII. Eviscerating, Edible Offal and Trimming 32
IX. Paunch and Viscera Handling 37
X. Rendering 67
XI. Plant Clean-up 78
XII. Appendices 79
A. Water Conservation and Waste Control in a Meat
Packing Plant
B. Water Conservation and Waste Load Reduction in a Modern
Hog Packing Plant
-------
ACKNOWLEDGEMENTS
This study could not have been completed without the assistance of
Mr. Stanley Lammers and his staff. In particular we are indebted to
Mr. Larry Walsh and Mr. Jack Nettleton who compiled the operation data; and
Mr. William Vis, who provided many hours consultation to ensure the study
group had a full understanding of the plant operation. Mr. Jack Witherow,
EPA, Corvallis, Oregon, critically reviewed this manuscript and provided
suggestions to clarify the presentation. Photographs were taken by Mr. Ronald
Wantoch and Mr. Les Vahsholtz. Art work was prepared by the Visual Information
Department of the Region VII Office.
Appreciation is given to the following for their contribution to the
success of the workshop:
Workshop Leaders and Staff
Paul M. Berthouex, Assoc. Professor
Dept. of Civil & Env. Engineering
University of Wisconsin
3216 Engineering Building
Madison, WI 53706
James R. Boydston, Chief
Industrial Waste Branch
Pacific Northwest Environmental
Research Laboratory
200 S. W. 35th Street
Corvallis, OR 97330
Robert W. Bray
Associate Dean & Director
Agriculture Administration
College of Agriculture
University of Wisconsin
136 Ag. Hall
Madison, WI 53706
C. J. Carlson, Vice President
Geroge A. Hormel & Company
P. 0. Box 800
Austin, Minnesota 55912
Donald 0. Dencker
General Sanitary Engineer
Oscar Mayer & Company
910 Mayer Avenue
Madison, WI 57304
John Dunning
The National Independent Meat
Packers Association
734 - 15th Street, N. W.
Washington, D. C. 20005
Jim Doughtery
Roy F. Weston, Inc.
West Chester, PA 19380
Dr. E. E. Erickson
North Star Research Institute
2100 - 38th Avenue
Minneapolis, Minnesota 55406
vi
-------
John G. KiHebrew
Mechanical Engineer
Swift & Co.
R. & D. Center
1910 Swift Dr.
Oak Brook, IL 60521
Stanley Lammers, President
Sioux-Preme Packing Company
Sioux Center, Iowa 51101
Donald S. Mckenzie
Dept. of Plant Operations
American Meat Institute
59 E. Van Buren
Chicago, IL 60605
Bruce Marsh, Professor
Meat & Animal Sciences
Univ. of Wisconsin
Madison, WI 53706
John P. Mohay
Executive V.P.
The National Independent
Meat Packers Association
Washington, D.C. 20020
Leo E. Orsi
Wilson & Company
4545 Lincoln Blvd.
Oklahoma City, OK 73100
Registered Conferees
Stephen W. Dvorak
Pres. Mgr.
Packer!and Packing Co., of Chippewa
Falls
925 W. River St.
Chippewa Falls, WI 54729
William Prokop, Director
Engineering Services
National Renderers Association
Des Plaines, IL 60016
John T. Quigley, Asst. Professor
and Program Coodinator
University of Wisconsin-Extension
Department of Engineering
432 North Lake Street
Madison, WI 53706
C. A. Santori, Exec. Vice President
and General Manager
Western States Meat Packers
Association, Incorporated
88 First Street
San Francisco, CA 94105
Victor Saulys
U.S. Environmental Protection Agency
Region V, Permit Branch
1 West Wacker Drive
Chicago, IL 60601
W. James Wells, Jr.
Bell, Galyardt, Wells
Architectural Engineers
5634 South 85th Street
Omaha, Nebraska 68127
Jack L. Witherow,
Industrial Treatment &
Cqntrol-Con/all is
UJ§. EPA
200 S.W. 35th Street
Corvallis, OR 97330
Robert E. Gerhard
National Sales Mgr.
Epco Div.
G. A. Hormel & Co.
P.O. Box 800
Austin, MN 55912
vii
-------
Horacio Gonzales
Supervisor
Dubuque Packing Co.
701 E. 16th St.
Dubuque, IA 52001
C. F. Greenhill
Proj. Engr.
Swifth Fresh Meats Co.
115 W. Jackson Blvd.
Chicago, IL 60604
Richard Hansen
Plant Superintendent
AMPAC
4277 S. Racine Ave.
Chicago, IL 60609
James Hatheway
Environmental Protection Agency
Box 25227, Bldg. 53
Denver Federal Center
Denver, CO 80225
William L. Hellman
Operat. Mangr.
Smith-field Packing Co.
Smithfield, VA 23430
D. L. Johnson
Proj. Engr.
Swift Fresh Meats Co.
115 W. Jackson Blvd.
Chicago, IL 60604
Robert Juergens
Ass't. Supervisor
Dubuque Packing Co.
701 E. 16th St.
Dubuque, IA 52001
Harold Lettington
Iowa Dept. of Environmental Quality
3920 Delware St.
P.O. Box 3326
Des Moines, IA 50319
Lawrence D. Lively
Super. Environ. Control
John Morrell & Co.
208 S. La Salle St.
Chicago, IL 60604
Norman McCabe
Chief Engr.
AMPAC
3946 S. Normal Ave.
Chicago, IL 60609
Paul T. McClurg
Sanit. Proj. Engr.
DeWild Grant Reckert & Assoc.
315 First Ave.
Rock Rapids, IA 51246
John McDowell
DHEW-FDA
Bureau of Veterinary Medicine
Div. of Veterinary Medical Review
5600 Fishers Lane
Rockville, MD 20852
Ervin Mel 1 em
Green Giant
5601 Green Valley Rd.
Minneapolis, MN 55437
Chris Mikkelsen
V.P.-Pt. Superintendent
AMPAC
3946 S. Normal Ave.
Chicago, IL 60609
Charles E. Mootz, Jr.
Chief Plant Fac. & Equip.
Staff, APHIS
U.S.D.A.
Washington, D.C.
viii
-------
Donald Pavlat
Engineer
Packer!and Packing Co.
of Chippewa Falls, Inc.
925 W. River St.
Box 576
Chippewa Falls, WI 54729
Jerry Richman
Superintendent
Dubuque Packing Co.
701 E. 16th St.
Dubuque, IA 52001
Robert Rohl
Div. Supt.-Hog Operations
John Morrell & Co.
No. Weber Ave.
Sioux Falls, SD 57101
William Rooney
Superintendent
E. W. Kneip, Inc.
404 West Nebraska St.
El burn, IL 60119
Mike Rudd
General Sales Mgr.
American Pollution Prevention
Co., Inc.
777 Grain Exchange Blvd.
Minneapolis, MN 55415
Marvin Seely
Div. Supt. - Beef Operations
John Morrell & Co.
No. Weber Ave.
Sioux Falls, SD 57101
Ronald J. Streeter
Environ. Engr.
Wilson & Co. Inc.
4545 Lincoln Blvd.
Oklahoma City, OK 73105
E. I. Tonseth, President
Aiwatech A/S
Industrial Waste Water Engineers
Harbitzalleen 3
Oslo 2, Norway
R*. H. Wantoch
Chem. Engr.
E.P.A.
25 Funston Road
Kansas City, KS 66115
Gordon Chesters, Director
Water Resources Center
University of Wisconsin
1975 Willow Drive
Madison, WI 53706
John M. Harkin
Assoc. Professor
Univ. of Wisconsin
Madison, WI 53706
James A. Chittenden, Director
Technical Services
Iowa Beef Packers
Dakota City, Nebraska 56912
James E. Kerrigan, Assoc. Director
Water Resources Center
University of Wisconsin-Madison
1975 Willow Drive
Madison, WI 53706
IX
-------
SECTION I
CONCLUSIONS
This document summarizes the experiences and needs of the meat
industry in terms of in-plant waste reduction.
Success of in-plant waste reduction practices depends on the
attitude of both the management and production personnel and their
respect of the person coordinating the waste reduction measures.
Key areas of in-plant waste reduction are blood conservation,
paunch handling, and cleaning the pens. Blood conservation and its
processing provide an excellent marketing opportunity to the industry
in terms of the protein demand in the world. Dry dump handling
of paunch contents is the system of choice from both an economical
and environmental viewpoint. The production of soil conditioners
by surface and/or subsurface spreading and the production of feeds by
ensilage or drying appear to be the most feasible measures for uti-
lizing paunch contents. Dry-cleaning the pens by the use of vacuum
systems coupled with pen design and land disposal of the solids can
effectively control the wastes originating from this area.
A hide curing operation will discharge nearly 1.8 kilograms (4
pounds) of salt per hide cured, and when combined with a slaughter plant
effluent, results in a concentration ranging between 750 and 1000 mg/1.
The eventual solution to the brine disposal problem will be for the hide
processor to produce either a pickled or tanned hide.
This document can be used by industry and government as supportive
information for application of effective in-plant waste management or
for development of research projects.
-------
There is a need in the meat industry for a periodic bibliography as
a reference source of information so that those involved with waste
management could readily locate past developments.
-------
SECTION II
INTRODUCTION
by
James E. Kerrigan
In December, 1973, a workshop entitled, "In-Plant Waste Reduction in
the Meat Industry" was held at the University of Wisconsin-Madison.
The purpose of the workshop was to bring together a broad range of
specialists informed in the area of slaughtering and the associated by-
product and waste management operations.
Participants at the workshop represented the following of plant
operations: meat quality control and health inspection; by-product
recovery and waste collection, handling and disposal. Because economic
production, meat quality protection and effective waste management are
interdependent, it is essential in minimizing waste to consider all
these aspects when recommending changes in a slaughtering plant operation.
Effluent limitation guidelines promulgated under the Federal Water
Pollution Control Act of 1972 were proposed at the time of the workshop.
They were issued by the Environmental Protection Agency on February 28,
1974. By-product recovery, waste collection and water conservation
practices within plants are expected to receive renewed emphasis because
of the guidelines. It was considered timely to identify alternative
activities that might be useful in reducing in-plant waste and avoid
the expensive waste treatment costs that are associated with producing
high quality water effluents.
Forty-five participants exchanged ideas and shared experiences with
one another during a two-day session. The format of the workshop was
designed to encourage dialogue between those attending with selected
session leaders directing discussion on ten specific topics. To provide
-------
adequate time for exchanging ideas, the topics were restricted to the
processes within the slaughtering operations. The topics were: pens,
blood conservation and processing, hide and hair removal and processing,
eviscerating and edible offal processing, paunch and viscera handling,
rendering and plant clean-up operations.
The program was developed in cooperation with representatives of
the American Meat Institute, the National Independent Meat Packers
Association, the Western States Meat Packer's Association, Inc., the
National Renderers Association, Industrial Waste Branch, Environmental
Protection Agency, Con/all is, Oregon, and from the University of Wisconsin.
The meat industry associations were responsible for encouraging their
members to participate in the workshop. Their efforts were effective,
for the principal waste control engineers and managers from fifteen
different firms were present, including two representatives from major
consulting engineering firms. Similar success resulted from the efforts
of the Environmental Protection Agency in inviting federal agency represen-
tatives to participate. Four members of EPA, all from separate regions,
attended the workshop, as well as representatives from the Meat and
Physical Facilities Inspection Division of the U.S. Department of Agri-
culture, the Division of Veterinary Medical Review of the Food and Drug
Administration, DHEW, and the Agriculture Research Service, USDA. To
complete the group, faculty members from four different disciplines and
a representative of the Iowa Department of Environmental Quality attended.
The basic concept of the workshop was to examine the various
divisions within the slaughtering operation to see where opportunities
exist for reducing waste. Among the questions asked are: What are the
current practices? What regulations or controls should be added or
deleted? What should be done that is not now being done?
-------
This publication collates the different areas discussed at the
workshop and its purpose is to:
1. Identify for the people in the industry the opportunities for
in-plant reduction techniques.
2. Give the U.S. Environmental Protection Agency a consensus from
a broad segment, of what research and demonstration activities
are most critical within the slaughtering process of the meat
industry.
3. Identify for individuals in government some of the proposed
modifications that may be considered in waste reduction areas.
4. Identify companion studies to insure that meat quality is
maintained at its present high standard. The control of high
meat quality and development of new methods for protection of
the environment must be accomplished hand-in-hand.
-------
SECTION III
PENS
Monitored
by
W. James Wells, Jr.
The purpose of this section is to review the matter of handling of
wastes from pens. This is probably one area where wastes are most
easily segregated from the other waste streams of the plant. There are
some differences on the handling of wastes from different animals, but
for the purpose of this discussion, they were reviewed collectively.
Generally, most pen floors are concrete and are washed down daily. The
frequency with which pen floors need to be washed vary between plants
and in part, depend on the concerns of the plant inspector.
Pen design is very important in regard to the effectiveness in
cleaning the pens. Experience has proven the waffle type pattern in the
concrete pens requires additional time keeping them clean. Rectangular
pens result in thirty percent of the area unusable. The fan-shape pen
has been found to be very effective. In this design,, the cattle enter
and exit at opposite ends. Total area of the rectangular pens is from
2 to 2 1/2 times that required for the fan-shaped design. Advantages to
the fan design, in addition to reduced area, are the less wastes entering
the treatment system and reduced water consumption.
Covered pens appear to be a matter of preference to the meat-
packer. Generally most of the hog pens are covered. For open cattle
pens, there exists the problem of storm-water runoff during heavy
rainfall which adds considerably to the waste handling problem. One of
the main reasons for covering pens is to protect the livestock from rain
and snow so as not to have wet cattle or sheep going into the kill which
presents problems with mud and contamination.
-------
For pen cleaning, a system used with some degree of success is
settling basins. These are designed with floors sloped at a five
percent grade to permit pen wastes hosed down to be settled in these
basins and allow a front-end loader to remove these wastes. Some of the
problems result in infrequent cleaning, thus allowing the basin to
become filled with solids, thereby losing its effect. These settling
basins are capable of removing 40 percent of the BODg. The wastes also
tend to liquify and become difficult to dispose. The ultimate disposal
must be to a land fill or on agricultural land.
Some pens are cleaned mechanically with the aid of front loaders
and the claims are that as long as bedding was adequate and pens were
cleaned frequently no problems resulted. Bedding materials used are
wood chips and/or sawdust. Pens should be dry-cleaned two or three
times daily, the bedding and waste mixtures accumulated and hauled to
land fill.
Vacuum type cleaning systems using septic tank pumps with an intake
nozzle similar to a vacuum cleaner can reduce the BOD,- by 25 percent.
This is a quick operation and can be effective all winter without
washing, but in the summer, the pens need to be washed at least twice a
week. The vacuum system is most effective when the pens are designed
for this type of equipment. This includes the fan-shaped design and
gates that swing out to allow a full sweep of the area by the vacuum
system.
Truck cleaning is necessary to control hog cholera and for meat-
packing plants to meet export requirements. The truck should first be
dry cleaned prior to wash down with the dry material going to suitable
land disposal.
-------
A method of handling the wastes from dairy holding pens that appears
promising is a collapsible dam at the top of sloping pens. Large quantities
of water, i.e., five thousand gallons, are suddenly released when the
dame is collapsed. The water flushes through the pens picking up the
bedding and manure. Sometimes two or three of these collapsible dams
are set in series along the slope. The final point is a sump pit and a
chopper pump. The flushed materials are then chopped and pumped to a
field where a rotating nozzle spreads this mixture over agricultural
field. The system reduces manpower requirements, but needs to be carefully
designed.
-------
SECTION IV
BLOOD CONSERVATION
Monitored
by
John KiHebrew
Blood has the highest BOD of any liquid produced in a meat processing
plant. One cattle contains approximately 50 pounds of blood which if
discharged into the sewer contributes a pollution load equivalent to
that of fifty people.
The important aspects of a good blood conservation program will be
discussed below.
Blood first presents itself in the plant on the kill floor in the
sticking or bleeding area. This area should be curbed and equipped with
combination blood and water floor drains. During operation and before
cleanup periods, the blood must be carefully squeeged to the blood side
of the drain, minimizing blood loss to the sewer when the drain plate is
changed. In many plants, the floor of the bleeding area is given an
initial rinse with a fine spray nozzle under high pressure which is sent
to the blood sewer. The cost of removing this small amount of water
from the blood is probably less than removing the blood from the waste
treatment system. It is believed that no investigation has been made as
to how many gallons of water are actually flushed down the drain for
this purpose, but it is felt that it is less than 75 gallons. The
bleeding area varies in size from plant to plant - from very small to
very extensive. Killing floors with insufficient bleeding areas usually
lose a lot of blood to the sewer because the cattle continue to bleed as
they travel across the floor. Management should always be alert to see
that the flow of cattle through the bleeding area allows ample time for
thorough bleeding, and that operators do not hurry up the process to
-------
gain extra breaks for themselves, etc. They should also see that floor
clean-up is done often enough that blood does not coagulate on the floor
requiring large amounts of water to remove it. Meters should be installed
on all water sources to quantify and thus control water use in this
area.
The extension of the use of combination of water and blood floor
drains around the various points of the dressing chain route has also
been discussed. Care must be exercised so that the gutter does not
cause the worker, with knife in hand to trip. This potential danger
requires that the blood be continuously washed away during the operating
day.
Various operations along the dressing chain route, such as head
washing and brisket opening, result in large amounts of blood being
spilled on the floor and then washed down the sewer. Attempts should be
made to design or alter these areas so this blood can be saved. This
seems to be easier to accomplish on hog killing floors than it is in
beef killing floors. Several plants have extended blood troughs on
their hog killing floors from the sticking area to the scalding tubs.
One plant has troughs below the dressing tables starting at the head
dropper and extending completely around the dressing chain route so that
blood drippage never finds its way to the floor and to the sewer. Much
of the blood coagulates in the hot water of the scalding tubs and this
is lost as far as recovery is concerned. However opportunities do exist
as to minimize the amounts of blood and sludge released to the sewers by
allowing the scalding tub contents to settle before draining. Dumping
the scald tub, immediately after the kill, should be avoided. After
allowing approximately one-hour settling time, the water can be decanted
from the top of the tub in a slow manner. The remaining heavy sludge
can then be dumped into a truck and spread with pen manure.
10
-------
A firm in Sweden is marketing a hollow sticking knife, designed to
collect blood from cattle or hogs for edible purposes. These knives are
connected to a vacuum collection system using artifical sausage casings
(which are cheap and disposable) instead of rubber hoses. This would
serve two purposes: the blood could be kept off the floor and it could
possibly be sold as a more valuable product with a greater return. Of
course, the problem of maintaining blood identity does exist. One has
to decide how much blood he is willing to lose if a condemned animal is
found on the killing floor. Some plants separate the blood into groups
consisting of blood from ten animals. This quantity would then be sent
to the rendering if a condemned animal was found in that group.
Blood lost to the sewer in a meat packing plant can be on the order
of 30%, despite collection systems specifically installed for its
recovery. Two methods of removing it from the waste stream consist of
the use of lignosulfonic acid (ISA) (1) process and electrocoagulation
(2).
In the ISA process, raw wastewater is chemically treated with
sulfuric acid and lignosulfonic acid. This treatment precipitates
soluble proteins, forming a flocculent mass suspended in the wastewater.
The mixture is then subjected to dissolved-air flotation that separates
the precipitate and other suspended organic matter from the wastewater.
The clarified waste is then neutralized with lime. The effluent has
greatly reduced levels of nitrogen, grease, suspended solids, biochemical
oxygen demand and live organisms. Sludge from the flotation unit contains
about 40 percent protein (dwb) and can be sold as an animal feed ingredient.
Alwatech A/S, an Oslo, Norway, based company, developed the process.
In Kalmar, Sweden, a small integrated pork and beef plant has a full
plant ISA process in operation which is economically selfsupporting.
11
-------
Electrocoagulation, another clarification process, has possibilities
in reducing the effect of blood lost to the sewer when used in conjunction
with chemical treatment. Developed by Swift & Company for use in the
meat packing industry, the process electrolytically neutralizes the
negatively charged particles in the wastewater. Passage of a direct
current through the wastewater forms large quantities of microbubbles of
oxygen and hydrogen in the wastewater due to electrolysis. The addition
of coagulant aids, such as ferric sulfate and an anionic polymer plus
calcium hydroxide for pH adjustment prior to electrocoagulation, are
necessary to remove the proteinaceous organics contained in the blood.
Both processes, ISA and electrocoagulation with chemical treatment,
increase the protein content of the waste sludge to a level such that
by-product recovery alone might make the process economically desirable
in addition to allowing the plant to meet effluent requirements.
References
1. Hopwood, A. P. and G. D. Rosen. Protein and Fat Recovery from
Effluent. Process Biochemistry V. 7 (3) 1972.
2. Beck, E. C, A. P. Giannini, and E. R. Ramirez. Electrocoagulation
Clarifies Food Wastewater. Food Technology, Feb. 1974.
12
-------
SECTION V
BLOOD PROCESSING
Monitored
by
C. J. Carlson
Generally every plant does something in regard to blood processing
and has been doing so for years. The methods may not have been too
effective, but nevertheless it was being saved to make some final use of
the blood.
Probably the initial way of handling blood resulted when Purdue
University came up with the idea that this blood could be used in animal
feed and was excellent for hogs replacing corn in the diet. This was
early in 1900 and more or less took blood out of the fertilizer category
and put it into the feed category resulting in a better gross return to
the packer. The accepted way of drying blood then was to store it in a
coagulating tank, inject live steam to coagulate it, put a cart underneath
to draw off all the free serum, and transfer the coagulated mass to a
dryer. While this method was crude, it is still being done the same way
in some plants.
Another way was to pump the blood into a conventional dry melter
which resulted in less loss and a dry product. It was an improvement
but presented an odor problem. The big problem was quality control and
it was difficult to obtain a consistent product as far as temperature
was concerned. An addition of bone or other solid had to be added to
prevent blood build-up on the sides of the melter, which in turn would
cut down on the heat transfer and increase the drying time.
A tremendous amount of horsepower was needed to net a small amount
of the product. At one point in the operation, the entire mass becomes
13
-------
practically adhesive and at that time the horsepower demand greatly
increases to hasten the drying process. In the summer fans are kept
blowing on the heaters on the motors just to keep them in operation
during this critical glue state. This idea of blood processing reflects
the type of thinking people in the rendering business had for many years
without much thought to cost economics or saleable items.
In the situation today, many of these old plants are still in
operation, but several innovations have taken place in the past ten
years which are a definite improvement. One is the use of spray dryers,
this blood has a high degree of solubility. Its big impetus was in the
fifties when the demand for blood was used by the adhesive industry.
Also these sprayers were available from the dairy industry, and were
relatively cheap.
The feed industry tended to back away from dried blood because of
its solubility, it was very dusty, difficult to handle in bulk form.
Problems were encountered in operating this equipment because the yields
were low, only 18% solids and if at first an attempt was made to evaporate
the product and increase the concentration up to 35 or 40%—the evaporation
had to be done at a low temperature. This is due to the disasterous
effect of coagulation within the evaporator. The second problem was
collection. In a small community where this type of operation was run,
the dust collectors were 99% efficient, but the 1% caused problems. A
red film covered everything and it had a unique capability in its reaction
to paint. On one occassion six houses had to be painted because they
all turned a pastel color.
From that system evolved the famous ring dryer, it is essentially a
spray dryer which agitates to keep the product from too much coagulation
From the dryer the blood is pumped through a coagulator, then on to a
small type of expel!er which squeezes out the free serum. The solids
14
-------
are again fed back at the start of the system and then into a
disintegrator which sizes the materials and feeds it into a manifold
where it is mixed with high temperature air (900°F) from the gas-fired
furnace. The air velocity picks up the product that travels in the ring
and as it dries the product migrates to the top of the air flow and is
syphoned off into a cyclone where it is separated and drops into storage
tanks. The water material continues to recycle until it is dried. The
advantages of this system are that the blood is high quality with no
contamination in it and is an excellent product from a nutritional
standpoint. The disadvantages are that it is a great air polluter.
Dust conditions within the room are bad. It is difficult to load
because of its fluffiness and small particle size.
Another system is the Del-aval centriblood system, which improves
the recovery of solids after coagulation. Instead of going over a
shaker screen—the product goes through the conventional DeLaval
decanter which is effective in extracting the serum water.
The economics of drying blood should be thoroughly considered as it
has fluctuated considerably. In July 1972, it was $120/ton or six
cents/pound and had been in that area, plus or minus $10-$20 for about
20 years. When the protein shortage developed, blood prices rose in
July 1973 to $452/ton or 22.6 cents/pound and the December 1973 price was
$288/ton or 14.4 cents/pound. In the hog processing , the gross value
to the packer has been varied, from ten cents to thirty-five cents per
hog. Drying costs by conventional drying methods run about five cents
per hog. Operating costs are $80 to $100 per ton to dry the blood so
the return grosses about 25 cents per hog. At a kill of 20,000 hogs per
week a gross return of about $5,000 net is obtained from dried blood.
The opportunity for packers in regards to drying blood economics is
better now than it has ever been. Lysine availability which to the
average processor means little, but will become important when future
15
-------
major feed manufacturers will buy blood not on protein but lysine
availability. Blood now is being quoted in two different ranges,
regular product and high-lysine product.
Buyers from three major companies report that in the near future,
quality programs are to be established, setting up price standards based
on lysine availability rather than on the percentage of protein and dry
blood.
Today, high-lysine commands about $125/ton premium over regular
dried blood. Normally produced dried blood in which the heat is not
controlled, allows the lysine to become denatured and is not biologically
available from a nutritional standpoint. Whole blood normally contains
about 7 or 8% lysine and via regular processing contains up to 48-50%
lysine. Drying through a ring dryer brings the lysine availability to
90%. Eventually the marketability of blood will be on strictly lysine
availability and the regular blood economic returns will be disappointing.
Another alternative which should be looked at is the blood being
relegated into animal feed and its nutritional value. It has high
protein so should be more valuable than just animal or pet foods.
Fractionation of blood is not difficult. It requires immediately
upon collection the addition of an anti-coagulant agent, usually sodium
cytrate. It is then put through a centrifuge where the red blood cells
are extracted from the plasma resulting in 35% solids red cells and the
plasma has 10% solid red cells. Red blood cells dry nicely in the dryer
removing the glue portion. The product in dry or frozen form has
excellent color. Assuming three pounds blood per hog recovered by
fractionation results in about thirty cents per pound just for the blood
cells.
16
-------
In Europe, blood plasma is highly regarded as an ingredient in
sausage making. It has emulsifying properties and can be whipped like
egg white albumin.
The plasma has shown good results in the calf-miIk replacer industry.
When blended with soluble proteins it gives an end product that exceeds
the casein quality of milk in terms of protein efficiency rating.
The blood plasma is now selling at 55 to 60 cents per pound. One
plant finds that the net per hog is about 58 cents which is an additional
33 cents per hog and an additional $5,000 a week on a 20,000 hog kill.
This utilization of blood plasma has a potential of over a quarter
million dollars for the industry. Industry has been very lax in exploring
the potential in this area. There have been campaigns to get this
included in the manual of meat products and in the 1973 edition it is
listed under Meat Byproducts.
The industry has to become more mature in its thinking in using
blood as an edible wholesome food product. Much more testing is required
in these areas. Maintainance of the dust level is difficult and is
something that has to be engineered out as well as the odor problem.
Studies were done using a steam tube dryer. They are effective due to
the temperature control nature of the system. The economics of fraction-
alization are promising with dried blood at 14.4/cents pound—serum
dried blood at 27 cents/pound—almost double plus the $1.00 per pound
for dry plasma.
17
-------
SECTION VI
ASPECTS OF POLLUTION FROM THE
BRINE CURING OPERATION
Monitored
by
Jimmie A. Chittenden
INTRODUCTION
To the beef man it is the package that holds the meat together; to
the tanner it is a rather imperfect raw material full of blemishes and
unwanted by-products that take all of his extensive skills to produce a
valuable end product; to the pollution man it presents nightmares of
virtually insolvable problems. The beef hide is all of the above and
more. This paper will concern itself with the pollutional aspects of
handling and brine curing the beef hide and suggest some alternatives to
solving the problems presented herein.
HIDE PROCESSING
Although there are probably as many methods for handling hides as
there are beef slaughter plants, most of the processes have many simi-
larities. This discussion will address itself to the modern brine
curing process using raceways. This process involves contacting the
hide with a concentrated brine solution to "cure" the hide, making it
stable against spoilage until it can be processed by a tanner.
18
-------
Washing and Defleshing
For the purposes of this discussion, it will be assumed that the
average hide dropped from the kill floor will weigh 81 pounds. This
average will naturally depend upon the type and weight of the animal and
to some extent the time of the year. Of this 81 pounds, there will be,
on the average, 5 pounds of mud and manure clinging to the hair side of
the hide. In addition, there will be around 11.5 pounds of flesh
remaining on the flesh sides of the hide before curing.
After the hide drops from the kill floor, it is run through a hide
washer. The standard design of hide washer involves using a forty foot,
horizontal perforated drum rotating at 9 rpm. The interior of the drums
has pegs that act to propell the hide to the discharge end as a result
of the drum rotation. In most systems the first two-thirds of the drum
has water sprays using recycled water at a rate of 365 gpm. The last
one-third of the drum uses fresh water at 40 gpm.
The hide washer is not effective in removing the large cakes of
manure, but it does remove the loose sand and much of the blood from the
flesh side of the hide.
After washing, the hide is then run through the demanuring and
defleshing machine. This machine has a high-speed, bladed cylinder that
contacts the flesh side of the hide and scrapes away the flesh remaining
from the hide removal process. The flesh is dropped below the cylinder
and is water-flushed to a collection screw at the edge of the machine.
This flesh must be collected and sent to the rendering department. The
water flush adds as much as 10 pounds per hide of water to be evaporated,
but sewering this water would greatly increase the pollutional load from
the operation.
19
-------
The demanuring side of the defleshing machine consists of a dull-
bladed cylinder that contacts the hair side of the hide. This cylinder
is effective in removing the manure caked on the hide. The manure drops
into a trough (separate from the fleshings) below the machine and is
flushed to the solids removal systems with the overflow water from the
hide washer. After this operation, the hide edges are trimmed to a
standard specification resulting in an average of 4 pounds of trim per
hide. These trimmings are generally combined with the fleshings for
transport to the rendering operation.
After flushing through the demanuring trough, the hide wash water
is passed over a static screen. The screen is fitted with 0.04000 inch
openings which are sufficient to remove a large portion of the manure
and hair in the water. The solids removed are landfilled. After the
screen, a pump recycles a portion of the flow back to the hide washer to
flush the incoming hides. The excess water, which is equal to the fresh
water added to the last 1/3 of the hide washer, is sent directly the the
slaughter waste treatment system.
Extreme care must be taken to keep the water in the washing and
flushing area segregated from the brine curing area drains. As will be
shown later, fresh water must be completely eliminated from the brine
drains.
Brine Curing Operation
There are several methods for curing of hides. These range from
the old salt pack system that required 30 days to cure the hide to the
more modern methods that require 16 to 20 hours to produce a stable
product. Each of the processes have the same objective: produce a hide
that will be stable in storage for up to one year.
20
-------
The raceway system contacts the hide with a concentrated brine
solution contained in an oval track raceway to accomplish the curing.
THe raceway is eight feet wide, eight feet deep, and approximately 100
feet in centerline perimeter. Two paddle wheels fitted with 10 horsepower
motors operating at 18 rpm keep the hide moving and assure intimate
contact with the brine.
Brine is continually recirculated from the raceway back to the
brine makeup unit to keep the slat concentration at 95% of saturation.
The hides are transported from the fleshing machine to the raceway
by a cable conveyor. The raceways are sized to hold a maximum of 1200
hides. After the raceway is filled, the hides are allowed to recirculate
at least 18 hours in the concentrated brine.
After 18 hours, the hides are removed by hand from the raceway and
loaded onto a cable conveyor for transport to the hide wringer. The
hide will carry an average of 40 pounds of brine out of the raceway.
The hide is conveyed through the wringer on heavy wool felt belts. The
hide, sandwiched between the felt belts, passes through two hard rubber
rollers and the excess brine is pressed from the hide. The wringer
brine is pumped to the brine makeup unit and returned to the raceway.
After wringing, the hide is then graded, folded, and weighed and
placed on a pallet. As the hides are folded, 1 1/2 pounds of salt are
added to the hide as a curing safety measure during storage and shipment.
The pallets are stored until carload quantities and accumulated for
shipment.
At the time of shipment, the hides are depalletized, re-weighed,
and loaded into box cars for shipment to the tanner. At this time,
approximately 50 percent of all U.S. hides are sold for export to
21
-------
foreign countries, so it is readily apparent that the hide must be well-
cured to survive the shipment to these tanneries.
Mechanics of Hide Curing
In order to determine the mechanics of the hide curing process, an
attempt was made to duplicate the hide curing process in the laboratory.
The curing approximated the hide curing process fairly well, but the
full scale operation produced a better cured hide than did the lab
process as measured by the final ash content of the cured hide.
The laboratory process was conducted using old brine obtained from
the hide operation. The salt content was maintained by adding the same
type of salt used by the hide company. Several pieces consisting of
four-inch squares of hide taken from the backbone area were added to
1000 ml beakers containing the brine. Laboratory stirrers were used to
keep the contents of the beaker well mixed during the curing process.
The brine strength was measured hourly and salt was added as required to
keep the brine concentration near 95% of saturation. At various intervals
two pieces of the hide would be removed and analyzed for moisture and
ash content so that duplicates were run at each control point.
Figure 1 depicts what happens in the curing process. The green
hide has an average moisture content of 63.5%. For the first four hours
in the raceway the moisture content drops dramatically to 53.4%. From 4
hours to 12 hours the moisture loss rate decreases and by 16 hours the
moisture content has leveled off at around 48.5%. On the same graph,
the ash content (or salt content) can be seen to have a correspondingly
rapid increase from 0.2% initially to 10.4% after 4 hours. After 16
hours, the salt content has leveled out at near 14.0%.
22
-------
to
co
16
o
0 10
tj 8
^ 6
co 4
2
0
^ 64
£62
LJ
Z 60
8 58
CO
54
52
50
48
HIDE CURING DYNAMICS
% MOIST a % ASH
vs.
CURE TIME-hrs
6 8 10
CURE TIME-hrs
12
14
16
Figure 1. Percent moisture and percent ash versus cure time
-------
In the full scale process, this final salt content will average
15.5% of the total hide weight.
If we resume the example begun in the first part of the paper, that
the 81 pound hide coming into the hide plant weighed 60.5 after defleshing,
demanuring, and trimming. After the brine cure and wringing, the hide
will weigh 58.1 pounds and the salt content will have increased from
0.12 pounds per hide to 9.01 pounds per hide. Therefore, since no hide
substance was lost in the curing process, the moisture lost by the hide
will amount to (60.5-58.1) + (9.01-0.12) = 11.29 per hide.
This moisture loss occurs during the curing process and, since
brine is continually recirculated to keep the raceway concentration at
95% of saturation, the loss shows up as a concentrated brine disposal
problem. At concentrations of 95% of saturation, each pound of water
holds 0.248 pounds of salt. Then 11.29 pounds of water will contain 2.8
pounds of salt, or stated another way, each hide cured results in a salt
loss to the skewers of 2.8 pounds.
As a result of splashing from raceways and drippings from the hide
conveyors, large amounts of brine are spilled on the floor of the hide
building. A series of gutters carry this brine to a central sump. The
contents of this sump are pumped across a static screen and the clarified
brine is returned to the raceways after reconstruction.
At the end of the day's operatipn, it is necessary to wash the
facility down to maintain acceptable sanitation conditions. Fresh water
is used for washdown. In order to minimize the amount of salt discharged
from the operation, the contents of the sump are pumped to the disposal
system during this washdown period. The diversion of the floor drains
to the disposal system is continued until the accumulation of brine
during the last 24 hours has been eliminated.
24
-------
The best run operations will have an average salt consumption as
shown below:
I Salt/Hide
Salt in Hide Substance 9.01
Salt added to folded Hide 1.50
Salt lost due to Hide Shrinkage 2.80
Miscellaneous Sewer Losses 1.19
Total 14.50 #/Hide
The miscellaneous sewer losses are primarily a result of clean-up
operations. The floors must be washed down daily for sanitation reasons.
Attempts have been made to use recycled brine for clean-up, but the
grease content of the brine made the floors too slippery. So, during
the clean-up process the sewers are diverted to the waste treatment
system and the fresh water used for clean-up by-passes the salt reconcen-
trators.
From the above tabulation it is clear, then, that if a hide curing
operation uses in excess of 14.5 pounds of salt per hide, there is an
opportunity to reduce costs and waste treatment problems.
BRINE DISPOSAL ALTERNATIVES
An average analysis of the brine discharged from the hide operation
is shown below:
25
-------
Effluent Analysis
Salt* 27.50
Total Solids% 31.04
Suspended Solids mg/1 13,800
Volatile solids mg/1 9,500
Grease mg/1 1.000
B.O.D. mg/1 3,900
C.O.D. mg/1 6,500
Total Nitrogen mg/1 600
The above analysis is sufficient to indicate that this is a difficult
waste to handle. With sufficient dilution, the waste can be handled
biologically, however, this waste will generally push the chloride
concentration of the total slaughter plant effluent to levels between
750 mg/1 and 1000 mg/1. At this point, the federal effluent guidelines
have not addressed chlorides, but many state water quality standards are
pushing for salt concentrations near 250 mg/1. In such cases alternatives
must be found for treating the brine waste.
Since salt is completely soluble in water, no chemical means can be
used to remove the salt from the brine. The newer developments of
reverse osmosis and electrodialysis are suitahble for treating salt
concentration of only 2000 mg/1 or less and the technology has not been
developed for the concentrations encountered in the brine curing discharge.
Two methods of mechanical evaporation have been considered. The
first method of evaporation considered was submerged combustion. In
this process, brine is contacted directly with the flame and high
velocity air. In a pilot plant operation submerged combustion resulted
in an extreme foaming problem that very quickly shut the evaporator
down. There was a strong odor similar to burning hair that resulted in
strenuous objections by those in the proximity of the test area.
26
-------
A vacuum pan evaporator was also tested for this waste stream.
Foaming was also a problem and fouling of the evaporator tubes was
indicated to be a problem, but the system could probably be made to
work. Our investigations indicated both the installed cost and the
operating cost were extremely high and made this an undesirable alter-
native if any other alternatives were available.
There are two established disposal techniques that have been
successful. In the Southwest, lined ponds sized for solar evaporation
have been used. If there is a sufficient differential between rainfall
and evaporation, the lined evaporation ponds are economical and present
little difficulty in maintenance. Asphaltic membranes have apparently
been the most successful, but the costs are significantly higher than
the plastic membranes that are also marketed for this purpose.
In certain areas, deep disposal wells are also an acceptable
disposal technique. There are underground strata that contain brine of
compositions near that of the hide company brine waste. In the areas
where such a zone is available, this should be the preferred disposal
method.
ALTERNATIVES TO BRINE CURING
As indicated in the introduction to this paper, the only purpose of
brine curing is to stabilize the hide during storage and shipment. The
tanner doesn't want the salt. As can be seen from the previous discussion,
he has significantly larger problems than the curing operator because
the tanner has to soak out 9 pounds of salt per hide. In view of the
increasingly stringent effluent limitations, it would appear that alter-
natives should be developed for stabilizing the hide.
27
-------
There has been some work done that indicates that certain bactericides
will give the hides a limited (in terms of days) storage life. Still
others have worked with freeze drying to reduce the moisture content to
levels that will give a good storage life. In South America it is
common to let the hide dry naturally in the open air. This has little
attraction for U. S. tanners.
The above approaches may work eventually, and maybe the finished
product can absorb the additional costs, but, in the final analysis,
none of the processes, including brine curing, add to the value of the
hide. Added value should be the primary consideration when evaluating
the alternatives to solving the pollution problems presented by the hide
curing process. In this regard, several companies are bypassing the
brine curing process and going to partial or complete tanning the hide.
While this discussion is not intended to be a treatise on the
tannery process, a brief description of the process is in order. In the
beam house, the hair is removed from the hide under alkaline conditions.
An enzyme treatment is also used to remove the remaining bits of fat
from the hide substance. The hide is then acid treated to stop the
action of the lime, and is a pretreatment to tanning. This operation is
called "pickling." At this point, the hide is stable and can be stored
for at least 60 days without damage to the hide substance. There is
both a domestic and foreign market for pickled hides.
If it is desired, the hide can be further processed through tanning.
The tanning process involves treating the hide with a chrome, vegetable,
or alum tanning solution to effect a permanent stabilization of the hide
substance. The chromed hide must be kept moist, but with that precaution,
the hide substance can be kept indefinitely without fear of spoilage.
28
-------
Recent advances in technology have proven that tannery wastes can
be effectively treated. The waste treatment process involves equalization,
clarification with coagulant acids, followed by an extended aeration
process. Tannery locations, however, must be chosen with care since
State Water Quality Standards can preclude the use of even this very
effective system.
SUMMARY AND CONCLUSIONS
Even with the best operating practices, a hide curing operation
will discharge nearly 4 pounds of salt per hide cured. This salt
loading will, when combined with a slaughter plant effluent, result in a
combined effluent salt concentration ranging between 750 mg/1 and 1000
mg/1, a level exceeding many State Water Quality Standards.
In certain areas, solar evaporation in ponds lined to prevent
ground water contamination provides an acceptable disposal method for
the brine discharge. In other areas, deep well disposal into brine
bearing strata can be adopted.
In areas where neither of the above are possible, vacuum pan
evaporation appears to be the best alternative, but the costs involved
are extremely high.
It is postulated that the eventual solution to the brine disposal
problems of the hide processor and concurrently a solution to the
existing tanner/finisher's major waste treatment problem will be for the
hide processor to produce either a pickled or tanned hide. In this
manner, the majority of the salt problem is eliminated and in doing so,
the value of the hide substance has been significantly improved. This
added value concept should be a major consideration in this and all
pollution control projects.
29
-------
SECTION VII
HAIR REMOVAL AND PRO'CESSING
Monitored
by
Leo Orsi
The process of slaughtering hogs is accompanied by hair removal and
processing. Generally the procedure is thus, the hog is put through a
scalding tub for approximately five minutes at 54°C (130°F) to soften
the hair. Next the carcass is run through the dehairing machine which
scrapes and rubs the hair off. In this machine a pan or screen on the
bottom catches the hair from which it can be disposed. A portion of the
hair that comes off in the scalding tub remains there until that tub is
dumped.
Some plants install a stationary or static screen to handle the
overflow of water from the scalding tub and recover hair and toe nails.
This hair mass is either dumped or some plants try to make proteins out
of it. The normal way is to put it in a batch-type hydrolizer, break
down the hair under pressure, and then dry it. One type of dryer is
similar to a feather-type drier used by the poultry industry. Generally
not too much water is used in the dehairing operations. The economics
of recovering the hair results in a profit. Since the protein values
have gone up, this material now sells at $200 a ton.
Various techniques for the removal of hair are being used. The
water has to be hot enough to penetrate the hair to the point where it
is attached to the skin. The hair is enclosed in the hair follicle
socket and held by a glue-like substance which has to be heated and
softened to enable the hair to be pulled out. Not too much water is
necessary in this process, but a lot of heat is. Some plants add
certain chemicals to these scalding tubs to increase the dehair
30
-------
operation. Lime retards the odors and decomposition of wastes in the
tubs and allows the use of the scald water longer. The real science is
to have good control of the temperature and to see that the equipment is
in proper condition. Disposal of the scald tank contents poses a problem;
dumping just compounds the problem.
More information needs to be available on the savings that might be
had in water and waste management if the hides are pulled rather than
dehaired. A substantial saving in hot water and energy might be realized,
but plants will not be changed unless it proves to be economically
feasible.
31
-------
SECTION VIII
EVISCERATING, EDIBLE OFFAL AND TRIMMING
Monitored
by
Don Dencker
Past and present practices in the hog kill operation usually
entail the use of large quantitites of potable water to wash the product,
to maintain cleanliness during production hours, and clean-up of the
equipment and work areas. In a typical hog kill operation, certain
edible offal and other products are removed which require extensive
cleaning and washing to meet the current sanitation requirements of
APHIS. The individual quality control requirements of the company may
also dictate that significant amounts of washing and sanitation be
employed which result in the generation of additional wastewater. Great
emphasis is being placed on meatpackers by the EPA to reduce water
consumption by practicing extensive dry cleaning methods before hosing
and strict management and control over housekeeping and water use practices.
The EPA has established water use guidelines for the "Best Practicable
Control Technology Currently Available." The achievement date is July
1, 1977, and by July 1, 1983, more restrictive guidelines to control
water usage are to be employed.
It is agreed that water use controls are desirable but the industry
questions some of the methods suggested. This is a competitive industry,
subject to national union wage scales and it would be extremely difficult
to get the management in large plants to substitute labor intensifying
practices for water use. Labor intensifying means extra hours of work
by a cleanup man and this, because the current hourly rate, including
fringes, amounting to $7/hr will cost more money to the company. Using
a typical cost for water and sewer charges as $0.16/1000 liters ($0.60/1000
32
-------
gallons); a plant would have to save 44,300 liters (11,700 gallons) of
potable water to justify one additional hour of labor. This is an
equivalent saving rate of 738 liters (195 gallons) per minute. A more
favorable picture is presented for hot water where the saving rate must
be 330 liters (87 gallons) per minute based on $0.36/1,000 liters ($1.35/1,000
gallons). Water saving costs should be built in either initially, or by
modification - not by promoting unrealistic labor practices in this
competitive industry. Production employees should be expected to turn
off all the water outlets when not in use. If it can not be made part
of their job, it will be difficult to conserve water.
The following are a few water saving modifications that may be
instituted in the plant operations. If there are no objections from
APHIS the hog rail polishers should be considered for elimination. This
machine does very little to remove hair and consumes large quantities of
water. If this is not acceptable, water volume can be reduce by partially
closing the manifold valve, using more effective nozzles, and adding a
trolly-activated switch so that the water is turned off the chain stops
or when no carcass is passing through the polisher. Another suggestion
is to relocate shaving area spray nozzles to where they would be more
effective. In other words, use the water where and when it is needed.
The final carcass showers could be redesigned with more efficient nozzles
and the bottom sprays turned off after the large sows have passed through.
Self-closing spray nozzles could be provided for stickers and head
droppers to reduce the amount of water which gets mixed with blood to be
reclaimed. Common sense should be used at the viscera table. Sprays on
these pans should be used only for one revolution at the end of the day
to rinse the material from the pans, and then be reactivated only at the
end of the cleaning and sanitizing operation during evening sanitation.
Hearts are currently processed by putting them through a slasher, then
through a drum washer, then hand slashed and mechanically washed in a
tumble washer. Tests should be conducted to determine if the hearts
33
-------
could be passed through the slasher twice and then put directly in the
tumble washing, eliminating the drum washer and the hand slashing operations.
This heart washer operation uses huge amounts of water. Operating
supervision is needed to insure this is done solely on a full batch
basis with less washing time. The automatic neck washer should be
modified by using a spray head to spray the carcass directly instead of
spraying it with water released through holes in the revolving drum.
The water should be turned on only when a carcass is being brushed.
These are what may be called after-the-fact modifications.
Equipment modifications have been successful on different operations.
Three will be cited. Visera pans are mounted on a moving conveyor.
These hold the animal intestines for inspection before processing.
Between each use they are initially rinsed to remove clinging meat,
sterilized with 82°C (180°F) water and finally chilled. All of this is
clean potable water. Another viscera oriented operation is the gut-
snatcher which moves along with the viscera pan on a separate moving
platform. The operator stands on this and moves with the carcass as he
places the viscera in a pan. This moving platform is also continuously
sterilized to meet government regulations. These sterilizing operations
are loosely designed by the equipment manufacturer and can waste 378
liters (100 gallons) of water a minute. In Madison, at Oscar Mayer, one
viscera line was using 738 LPM (195 GPM) of 1/3 hot water and 2/3 cold
water and it was modified down to 340 liters (90 gallons) per minute by
the selection of proper nozzles. One pan of spray headers had the hot
sterilizing spray nozzles only 8 centimeters removed from the cold pan
chilling spray nozzles and consequently did not raise pan temperature
properly for sterilization. This assembly was replaced with one that
greatly decreased the water consumption while concurrently properly
sterilizing the pans.
34
-------
The sterilizing and cooling spray locations were separated about
five feet and high-atomizing low-volume nozzles were installed to get
better cooling with less water. While making changes, care was exercised
to make certain that the production function was not adversely affected.
Washing equipment manufacturing companies and spray nozzle manufac-
turers are willing to come to the plant to help with particular problems.
Their field is small and they are dependent on this type operation.
A second area of water wasteage has.been the chitterling processing
department. The saving of chitterlings is still carried on in many
plants. These are large intestines which are sold for human consumption
as edible products to a limited market. Prior to 1959 they were washed
manually using 1325 liters (350 gal)/min of primarily cool rinse water.
Wages were then $2 to $2.25 per hour as compared to the current $7.00
per hour which was mentioned previously. As wages rose automatic
machines were installed and raised the flow volume up to 1892 liters
(500 gals)/minute for the same amount of product. Thus 568 liters (150
gal)/minute were added to eliminate a few job positions which was a
justifiable saving to management. Attempts to reduce flow by the
selecting proper spray nozzles to limit usage and locate them so they
would do what was intended cut water use back to 1140 liters (300
gal)/min. One chitterling department in a slaughtering plant still can
use up to a quarter million gallons per 8-hour shift and clean-up. This
accounts for about 20% of the total flow from a hog slaughtering operation.
A third operation modified was the stomach washer on the kill
floor. This operation increased from 170 liters (45 gallons) per
minute up to 416 liters (110 gal)/min with automation, or more than
double the original flow. With proper nozzles it was reduced back to
303 liters (80 gal)/min. Here is a case where automation, trying to
make more profit for industry, caused an increased flow of 132 liters
35
-------
(35 gal)/min, which in many operations the cumulative effect can be a
huge volume. Also, the improper operation of any one unit can offset
any savings gained throughout the entire kill floor. Kill floor equipment
is not usually designed for water saving and one may be forced into an
increased flow system for some time because of a better labor saving
operation which has been economically justified.
It is important that direct responsibility be designated to a
certain foreman or individual to ensure that all washing sprays are
turned off, especially during breaks, lunch periods, etc., because
leaving them on for 20 minutes while not operating wastes many hours
worth of water saving in other areas. Reducing water consumption is a
team effort and has to be done with production and management cooperating.
No on individual can do it by himself.
36
-------
SECTION IX
PAUNCH AND VISCERA HANDLING
Monitored
by
Jack L. Witherow and Stanley Lammers
PAUNCH HANDLING AND PROCESSING
Introduction
Paunch handling and subsequent processing of the paunch manure can
result in large financial and environmental costs. The selection of the
handling method largely determines costs and the processing techniques.
There are three handling systems and over a dozen processing techniques.
Though the slaughtering of swine, sheep and beef all require paunch
handling, this discussion is limited to the major waste source, beef
slaughtering. There are over 35 million head of beef slaughtered annually
in the United States which results in over 1.7 billion pounds of paunch
manure to be handled and processed per year.
Paunch manure is the partially digested feed contained in the rumen,
first stomach. Fresh paunch manure is a yellowish-brown color containing
recognizable fiber and grain and has an obnoxious odor. The material is
acidic with a pH ranging from 5.6 to 7.0. Even with its 85 percent
water content, only minor solid-liquid separation will occur on standing.
Baumann reported7 the wet weight and dry weight of paunch manure averaged
23 kg (54 lb)/animal and 3.8 kg (8.5 lb)/animal, respectively. On a
large number of determinations on paunch manure, mean values were
Chemical Oxygen Demand (COD)-177,300 mg/1 and five day Biochemical
Oxygen Demand (BOD5)-50,200 mg/1. Standard deviations were 38,500 mg/1
37
-------
for COD and 13,400 mg/1 for BODg. Other data33 show a BODg of 40,000
mg/1 and a BOD33 of 104,00 mg/1 with 85 percent of both values resulting
from the water soluble portion. The first stage carbonaceous oxygen
demand was complete in 33 days after which nitrification began.
Dehydrated paunch manure when placed in water had a BODg of 20,000
mg/lOOOg and a BOD after 131 days of 366,000 mg/lOOOg of dried material.
There was no sign of nitrification at 131 days. Paunch manure has such
an extended oxygen demand that the BOD,- is less than 40 percent of the
carbonaceous oxygen demand.
Waste loads from packinghouses are compared on the basis of Live Weight
Killed (LWK). All sewered wastes from a packinghouse average 12 kg
BOD5/1000 kg LWK. Paunch manure has a BOD5 of 2.5 kg/1000 kg LWK and
can constitute 20 percent of the waste load from a packinghouse.
Energy measurements on dried paunch material made with a Parr Oxygen
or
Bomb Calorimeter gave an average value of 4000 cal/gm or 7200 BTU/lb .
The nutritional analyses on dehydrated paunch are tabulated below:
Composition of Dehydrated Paunch
Item Mean (%) Std. Dev. No. of Dtm's
1.9 96
1.5 88
0.6 86
3.2 88
0.1 60
0.7 88
0.3 60
5.3 44
Moisture
Protein
Fat
Crude Fiber
Calcium
Ash
P2°5
Carbohydrate
6.8
12.7
3.1
26.2
0.6
7.2
1.5
40.8
38
-------
Handling Systems
The method of handling paunch is dependent upon the disposal media. The
limitations in handling and disposal are shown in Figure 1. Essentially
there are only four places paunch manure can be put, these are: the
air, the water, the land or by-products. The systems of paunch handling
are classified as no-dump, wet-dump, and dry-dump. All three systems
are used in the industry. In the no-dump system the paunch sack is left
unopened and both the sack and the paunch manure are sent to rendering.
In the wet-dump system, the paunch sack is sliced open and the contents
are water flushed from the sack into a sewer. In the dry-dump system
the paunch sack is sliced open and the contents are dumped and transported
from the plant in a separate non-water carriage system. The emptied
sack is then rinsed and the rinse water goes to the sewer. In the wet-
dump or dry-dump systems, the sack is sent to rendering or is used to
produce tripe.
No-Dump System
When the paunch sack is not dumped, the contents and sack are sent to
rendering and become part of the meal by-product. Sending paunch manure
to the rendering lowers the protein content of the meal, increases the
percent of water to be vaporized, discolors the greases and increases
the odor control cost. The potential use of the paunch sack for produc-
tion of an edible product (tripe) is also lost. Because of these
negative economic factors, the no-dump system has been practiced only on
condemned paunches which is a minor percent of the viscera rendered.
The no-dump system does eliminate the cost of transporting, processing,
and disposal needed in the other methods of handling. From all sources
the inedible dry rendered tankage amounts to 15 kg (33 Ibs) per steer
(at 16 percent fat plus moisture). Thus the addition of 3.8 kg (8.5
39
-------
PAQJJfolOHI MARJDDLDfoKB QDOAGRAIMJ
±
NO DUMP
Rendering
Gases
Treatment
Reuse
Air
PAUNCH COHTflt/TS
i
WET DUMP
I
DRY DUMP
Solids
Liquid-Solids
Separation
Treatment
[Solids I
Land
J
Transporting
By Product
Processing
I Water |j Land || I Air Jj
Reuse
Figure 1. Paunch handling systems
-------
Ibs) (at 8 percent moisture) of paunch contents is 25 percent of the
meal and reduces the protein content by 7.5 percent. At 6.25 times the
nitrogen content, the meat meal is 92 percent protein, and the combined
bone and meat meal is 52 percent protein. Cost penalties occur if the
protein content of the meal drops below 50 percent. Operation of the
rendering units can minimize the discoloring of grease. Thus the loss
of an edible product (10 kg (22 Ibs) of tripe/steer) and vaporizing of
water (21 kg (47 lbs)/steer) are the major economic factors. In plants
where tripe is not produced, the no-dump system may offer opportunities
especially if other costly paunch processing systems are required.
Wet-Dump System
The sluicing of paunch manure with spray washer is undoubtedly the
poorest system from the viewpoint of pollution control. Nevertheless, a
12
1967 survey by Camin showed that 84 percent of the industry employed
the wet-dumping system. Sending all the material for treatment was
practiced by 13 percent of the industry. Liquid solid separation with
off-site disposal of the solids was practiced by 70 percent. Using a
water carriage system will result in between 60 and 85 percent of the
BOD5 and about 5 percent of the fine solids passing through the typical
screens used for solid-liquid separation. This material loss to the
treatment system will be 2.0 kg. BOD5/1000 kg LWK and 0.4 kg Susp.
Solids/1000 kg LWK.
18
Paunch manure is untreatable in a conventional sewage treatment plant
for the following reasons: (1) the manure solids settle out and tend to
harden to the consistency of low density rock, (2) the solids clog
hopper bottoms, pits and pump suctions, (3) augering can be required to
remove the solids from pipelines; (4) the cellulose material will not
decompose in digesters and forms straw blankets which clog and eventually
fill digesters, and (5) the entrapped moisture in the cellulose material
can not be dewatered by vacuum filters.
41
-------
The use of vibrating, rotating or stationary screens serve a most
valuable function in separating the solids for transport to ultimate
disposal. Without screens the wastewater treatment system must include
specially designed liquid-solid separation, solids handling and
stabilization facilities. A system such as this contained enlarged grit
basins with mechanical scrapers, a paunch holding tank to periodically
"blow" the paunch solids through an air conveying line and disposal
lagoons.
The moisture content of screened solids is essentially the same as dry-
dumped paunch manure. The cost of handling the screened solids will be
essentially the same as that of dry-dumped solids. However, with the
wetdump system, extra costs will be incurred for the water carriage
system, the water, the screens, and most significant, the treatment of
the soluble BOD. The carriage water must have a high degree of
treatment to be discharged to receiving waters. The required treatment
will necessitate not only reduction of the oxygen demand, but also
separation and disposal of the paunch fines and biological solids
produced in treatment. The wet-dump system is no longer the most
economical one because of the increased treatment costs.
Dry-Dump System
The dry-dump system is replacing the wet-dump. The dry-dumped paunch
will have a moisture content of 85 percent. The elutriated paunch
solids in a water carriage system when separated on screen have an 81 to
82 percent moisture content. The dry-dump handling system can
incorporate the same transporting and processing methods used for
screened paunch solids.
Transporting paunch solids out of the plant has run into problems when
pumps and pipelines are involved. The solids tend to plug the line and
42
-------
pump intake facilities. Two transporting methods which have been found
satisfactory are a screw conveyor and an air energized system in which
the material is intermittently blown through a pipeline. Paunch
material has been successfully blown 200 meters (700 feet) with an
elevation increase of 14 meters (45 feet). If the material is
transported away from the plant site without processing, it is commonly
moved in specially designed trailers. The trailer must prevent spillage
and is commonly shaped like a tank truck with a covered top to contain
odors and a rounded or sloped base to prevent paunch solids from
sticking in the corners.
Processing Systems
Though the future for paunch handling is seen as the dry-dump system
with auger or "blow" transport systems, the method of processing and
disposal media is far from clear. Technology on a series of processes
and operations has been developed on paunch manure over the years and
the potential is noteworthy for transferring technology from
agricultural investigations on animal manures. A tabulation of paunch
processing technology with a brief description of individual operations
follows:
Paunch Processing Technology
Process
Stabilization:
Mositure Transfer:
Thermal Drying:
Operation
Surface Spreading
Subsurface Spreading
Mixing with Refuse
Lagooning or stockpiling
Mixing with Feeds
Rendering
Rotary Dryer
Fluid Bed Dryer
Solar & Air Drying
By-Product
Soil Conditioner
Soil Conditioner
Land Fill
Land Fill
Feeds
Feeds
Feeds
Feeds
Feeds
43
-------
Mechanical Dewatering: Presses
Screens & Filters
Thermal Conversion Incineration Gases & Ash
Pyrolysis Fuel & Chemicals
Biological Conversion: Composting Soil Conditioner
Ensilage Feeds
Single Cell Protein Feeds
Digestion Methane
Physical Conversion: Board Mill Wall Board
Surface Spreading
Chittenden13 has reported on a surface spreading system containing a
screw conveyor, a prebreaker, a blow tank, pipelines, an elevated
storage tank and a specially designed spreader truck. The truck has a V
bottom tank with a screw in the bottom and a knife valve at the back. A
spinning plate below the valve spreads the paunch as the truck moves
across an agricultural field. The truck holds 10 tons metric (11 tons)
which can be spread in 10 minutes. Application rates of 6.7 tons metric/
ha/week (3 ton/acre/week) have been used on one field for up to five
months. During the Nebraska winters it is possible to spread on all
frozen fields, but in the springtime during muddy conditions, it is
necessary to spread on grassland.
Odors and flies are a problem during warm weather. Discing the field
and the addition of an insecticide have been helpful. The quality of
the surface runoff or ground water from these fields has not been
evaluated. The spreading was done by a local landowner at 4 cents/animal
until his truck was paid for, after which the cost was reduced to 3
cents/animal.
44
-------
Subsurface Spreading
28
Smith and Gald have reported on subsurface injection of sludges and
have done work on adapting the equipment to handle paunch manure. The
injectors can be operated at depths ranging from 8-25 cm (3-10 inches).
Sewage sludges are fully covered with an operating depth of 8 cm at 530
1pm (3" at 140 gpm) discharge and with a depth of 10 cm at 760 1pm (4"
at 200 gpm). Application rates up to 100 dry tons metric/ha (45 dry
tons/acre) have been achieved in nine applications over a two-month
period. The machine has been used with sludges having solids content up
to 10 percent and could be adapted for sludges with a 20 percent solids
content.
The reported advantages are: elimination of odor and fly problem;
minimization of contamination of runoff water; addition of organic
matter to the soil; solids can be handled without dilution or drying;
and elimination of viewing by the public. The costs range from 2 to 4
cents/1000 liters (8 to 15 cents/1000 gallons) for injections of sludges
at a 5 percent solids content. The disadvantage is that injection is
not practical in frozen high moisture soils, and paunch holding facilities
during winter operations have not been tested. Smith has proposed
storage and operational schemes to handle this problem.
Mixing with Refuse
Paunch manure causes problems when placed in sanitary land fills, in
that the high moisture content of the material makes the fill unstable
and solids come to the surface. Sioux City, Iowa officials have been
successful in land filling paunch when it has been incorporated with
brush. Paunch mixed with discharged wood chips, used in the holding
pens to adsorb droppings, has also been satisfactorily disposed of in
land fills. Since paunch manure has a tremendous oxygen demand, land
45
-------
fills in which it is placed should be constructed with ground water
protection.
Lagooning or Stockpiling
The South St. Paul, Minnesota municipal treatment plant separated paunch
solids in a grit chamber and disposed of the solids in a large lagoon
with sealed bottoms and sides. The solids would lose moisture and
become firm enough to walk upon. However, the material had to be
removed prior to enlargement of the plant as it was not stable enough
for construction. The lagoon storage resulted in nuisance complaints
due to odors.
Stockpiling is a process of transfer of the moisture to land or air.
The moisture content can be lowered by 2 to 5 percent by drainage of
free water if stockpiled a few hours, and up to 65 percent by evaporation
over several weeks. Odors, flies, and precipitation are problems.
Because the major part of the BOD of paunch is water soluble, drainage
or precipitation coming from the stockpile must be prevented from entering
surface or ground waters.
Mixing with Feeds
Mixing fresh paunch with dry feeds materials utilizes the paunch juices
to raise the feed to the desired moisture. This saves the energy
required for drying the paunch for feeding. Nutritionists have proposed
the feeding of fresh paunch as a part of the animal's diet. Both horses
and beef cattle have been observed feeding on fresh paunch manure when
dumped in their pasture. An Iowa farmer is reportedly feeding swine on
fresh paunch manure. He feeds the material in troughs in a pasture to
control nuisance conditions. A longer than normal time period is needed
to fatten the swine from 40 to 100 kg (90 to 220 pounds). The known
46
-------
examples of mixing wet paunch with feed materials are to produce silage.
Production of silage is both a moisture transfer process and a fermen-
tation process to improve the digestability of the product and is described
later in this section.
Rendering
Rendering of paunch manure is essentially dehydration accomplished in
dry rendering units. In the no-dump system or when paunch manure is
mixed with fatty materials rendering units are necessary. If the paunch
manure is dehydrated separately then specially designed dryers are more
efficient.
The rendering of paunch most likely brings to mind the unsuccessful
application of the Carver-Greenfield process at Omaha, Nebraska. The
rendering plant was designed to receive the combined skimmings and the
q
settled solids from the 60,000 m /day (16 mgd) of raw wastewater from 19
packinghouses. These materials were ground to a particle size of 13 cm
(1/8 inch) or less, slurried with a fluidizing animal oil at a ratio of
6 parts of oil to 1 part dry solids. The slurry was metered to a
triple-effect, falling film evaporator where the water was removed under
steam heat and vacuum. On leaving the evaporators, the dry fluid slurry
of oil and solids entered a separation system. A portion of the separated
oil was returned to the fluidizing tank and the other portion to finished
oil storage tanks ready for marketing. The solids are transferred to
storage silos for use as a feed supplement or fuel. The system fell
short of expectation; recovered grease is so degraded that the output is
disposed of in a land fill. Omaha's current litigation is not over
equipment reliability but over the value of the grease produced.
47
-------
Rotary Dryers
An EPA demonstration project7 successfully dried paunch manure in a gas-
fired rotary dryer. The total cost was $38.46/dry ton of paunch or 16<£
per animal. Capital cost for the dryer and housing was $85/animal
slaughtered/day. In terms of the BOD removed, the cost was 8<£/lb of
BOD,-. Cost of BOD removal in a waste treatment plant ranges from 5 to
b
10^/lb of BODf.. Two problems of the process were odor control and a
y
limited market for the dried feed material. The packer has installed a
scrubber for odor control and a pelletizing machine to increase sale of
the dehydrated paunch. The EPA report recommended research on the use
of dried rumen as an animal feed additive. The packer, the manufature,
and EPA have been carying out separate feeding trials. The packer
participated in a feeding program on hogs and reports all the material
is now being sold for feed.
An EPA project with Oklahoma State University utilizing dehydrated
paunch manure as a feed supplement in channel catfish farming has been
completed. The feeds which contained by weight either 10, 20, or 30
percent paunch were formulated to be isonitrogenous and isocaloric. The
growth rates of the fish were compared with those that were given
standard commercial feed in both pond and cage cultures. In pond
culture, the growth rates and the yields per acre of the fish receiving
10 percent and 20 percent paunch-containing feeds compared favorably
with that of the control fish. However, growth rate and yield per acre
decreased significantly when 30 percent paunch containing feed was used.
In cage culture, the only experimental feed used was a floating pellet
feed containing 10 percent paunch. Fish in cages where this feed was
used also had growth rates and yields which compared favorably with
controls where standard commercial floating pellet feed was used.
48
-------
Monitoring water quality showed that neither the pond culture nor the
cage culture had caused deterioration in water quality in the ponds to
any appreciable degree in one growing season of 24 weeks.
The manufacturer of the rotary dryer is developing the economic feasibility
of drying and feeding a mixture of fresh paunch contents and whole
24
blood . Mixing the two gives a product with a protein content of 43
percent and requires the use of only one dryer for small and medium
packers. Feeding trials on the product have been conducted utilizing
20
feedlot cattle . The paunch-blood meal was concluded more valuable
than cottonseed meal in cattle feed. The total economic benefit should
include not only the resulting feed values but also the cost of otherwise
disposing of the paunch. A large packer is presently installing this
drying system and will use the product in a cattle feed. Reece and
26
Wesley conducted field and laboratory experiments using blood meal and
paunch blend in channel catfish diets and found that the fish readily
accept the blend as a principle protein source. The investigator concluded
that the blood meal-rumen contents blend has value as a partial or
complete substitute for fish meal in commercial catfish rations.
Fluid Bed Dryer
The two common technical problems with dryers are odor problems and
fouling of the heat transfer surface with dried material. A manufacturer
claims25 to have successfully piloted a fluid bed dryer that solves both
problems. The unit incorporates a cylindrical fluidized bed of silica
sand with a fluidized bed of the same material in a jacket around the
outside. High temperature gases pass through the outside jacket and
transfers heat to the fluidized solids. The wet paunch manure fed to
the center of the dryer is dried as the paunch manure floats up through
the interior fluidized bed. Thus, the paunch manure is not in direct
contact with the heat exchanger surfaces. The gases from the drying
49
-------
operation are deodorized by incineration. The dried material can be
used as a fuel or as a feed component.
Solar & Air Drying
Fuel costs for drying paunch manure in a rotary dryer were $8/ton of
dehydrated paunch or 3.5<£/animal . Thus if air drying or solar energy
replaced this source of heat, fuel costs would be eliminated and the
potential for lower total cost increased. Yin and Farmer have reported
on pilot investigations of both methods. One common difficulty is the
surface layer of the material dries rapidly, forming a crust, after
which the underlayer remains wet for a long time and becomes moldy.
When turned daily, a 10 cm (4") layer of paunch was air dried within a
week and the dehydrated product (16 to 20 percent moisture) was stored
in burlap bags for months without spoilage. Problems encountered in
air drying were (1) the rewetting of the paunch by precipitation through
the open sided drying shed and (2) the production of flies and odors.
These problems were eliminted with the construction of a solar still for
drying. However, the crust formation still occured and required the
development of a mechanical device to turn the material several times a
day.
19
Horsefield tested a small air-supported solar dryer in which fresh
dairy manure at 80 percent moisture content was placed. The fan supporting
the clear polyethylene cover provided an air exchange of 4 to 6 cfm per
square foot of manure surface and at no time was condensation ovserved
on the underside of the cover. Stirring several times a day of the
extremely wet material was necessary to prevent a crust from forming on
the surface. Flies were killed with an electric grid over the exhaust
port. During the test, the daily solar radiation was 2000 BTU/sq ft/day
and the ambient temperature was 32°C (90°F). The dryer converted 60
percent of the incident solar radiation energy to water vapor. The
50
-------
moisture content of the manure was reduced to less than 10 percent.
Drying times and size of the solar dryer computed for the climate in
Lafayette, Indiana, indicated economic feasibility.
Presses
In the past, dewatering paunch manure by mechanical means has been
considered economically advantageous to thermal drying. For the same
reduction in moisture mechanical dewatering is less expensive than fuel
fired drying. However, juices which can be pressed from paunch are
reported as having a BODg of 100,000 mg/113. This is equivalent to .23
kg (0.5 Ib) BODg/animal for each 10 percent reduction in moisture
content obtained. The present sewer charges in Chicago, IL influenced
one packer to eliminate presses and go to a dryer.
Paunch solids contain straw and fibers which expand after compression
and have a felt-like interlocking texture. These characteristics cause
clogging in most dewatering equipment. Among these were presses,
screwfeed wringers, and centrifuge mechanisms. Presses used in other
industries were tried including paper pulp presses, wine presses, and
sugar cane presses. The most successful equipment was a press used by
the brewing industry to dewater spent grain. A continuous feed device,
it employs two rotating perforated disks. The disks face each other at
an angle so that the spacing is wide at the tope and narrow at the
bottom. Material fed in at the top is compressed by a wedging action as
the disks' rotation carries it downward. Moisture escapes through the
perforations. Moisture reduction of up to 30 percent was accomplished.
Another investigator25 found that both a three roller mill and a modified
screw press could dewater paunch manure to a solids content approaching
40 percent. A conventional screw press was field tested, but the machine
failed before any dewatered paunch was discharged. Failure was due to
51
-------
an overloaded motor. An improved design, which incorporated an expansion
zone to compensate for the paunch swelling action after compression,
reduced the drive and motor requirements. This machine was tested on
paunch manure (18 percent solids) and dewatered the material to 38
percent solids. The liquid underflow stream contained 3.5 percent
solids. A three roller machine was tested and after some development,
the solids stream from the rollers reached 37 percent but the liquid
discharge contained 6 percent solids. The screw press was selected
because of the lower solids concentration in the liquid stream leaving
the press.
Filters and Screens
The general use of this equipment is to separate solids from carriage
25
water in a sewer. A laboratory and pilot scale investigation was
carried out on a sand filter and screen. Several types of application
to the sand filter were investigated, but the increase in the concentration
of solids was only 7000 to 8000 mg/1. Utilizing the 10 pounds/square
2
inch of pressure increased the filtration rate from under 0.14 1/sec/m
p
to 1.19 1/sec/m (0.2 gpm/sq. ft. to 1.75 gpm/sq.ft.), but solids content
could not be increased above 19 percent. Evaluation of a static-angled
screen showed the paunch solids could be dewatered to 18 percent solids
on this equipment. The filter and screen did not significantly increase
the solid content of paunch manure above the 15 percent found in the
rumen.
Incineration
Paunch incineration has been considered where urban location has resulted
in costly or prohibited truck transportation or municipal treatment, or
where disposal of several solid wastes is necessary. Omaha officials
had an engineering design prepared to utilize a rotary kiln incinerator.18
52
-------
The incinerator was to be operated at 649°C (1200°F) and the exhaust was
to be used to preheat the solids. The exhaust was to pass through a
scrubber and the ash sluiced to a nearby lagoon. (A subsequent design
utilizing a rendering process was selected).
A Chicago packer undertook design and construction of a fluid bed
incinerator with 60 percent financing under an EPA demonstration grant.
The packer ceased slaughtering prior to construction of the incinerator.
A major packing company submitted an application to complete the project.
The project incorporated a fluid bed dryer and fluid bed incinerator.
The fluidized bed dryer was to operate at 104°C (220°F) and to increase
the solid content to 37 percent. The gases from the drier were added to
the incinerator above the fluidized bed to destroy odors. The incinerator
was designed to burn the dried paunch manure on a one shift/day basis.
Pen manure, waste fat, waste paper, trash, etc., were to be burned on
other shifts. Incineration is self sustaining when the solid content of
paunch manure is over 30 percent; however, auxiliary fuel injection was
planned to insure operation at 1350°F. A water scrubber was to be used
on the exhaust of combined vapors. An offer of funds was made, but
price increases for the paunch dryer, incineration and auxiliary equipment
raised capital costs to $400/animal slaughtered/day and the packing
company went to a land spreading system. The packer estimated the
annual cost for capital and operation of the dryer-incinerator system to
be double that of a surface spreading system.
A packer in Louisiana has operated a dual chamber incinerator for
several years. This package unit has a rated capacity for 612 kg/hour
(1350 Ibs/hour) of rubbish at 50 percent mositure and a 7 million
Btu/hour heating capacity. A conveyor takes a mixture of solid wastes
into the primary fire chamber. Uncombusted solids or gases are burned
in a second chamber containing an after-burner. A high speed blower is
used to support complete combustion. The incinerated material includes
53
-------
hog hair, flotation skimming, paunch manure and pen manure. The paunch
solids are not dried but mixed with other wastes prior to incineration.
Pyrolysis
Pyrolysis differs from incineration in that it involves heating without
oxygen. The basic purpose is to decompose complex organics to simpler
materials. The major potential of the process is that by-products could
be sold to reduce operating costs. A recent pyrolysis study using
steer manure separated a variety of alcohols, aldehydes, ketones, acids,
amines and phenols. The by-products were valued at 2.2 to 4.4£/kg (1 to
2<£/lb). Break-even pyrolysis eocnomics would be achieved only if the
pyrolysis product has a value of 18<£/kg (8
-------
composting does stabilize the material, there is a limited market for
the product in the United States. A commercial paunch composting process
is in operation near Austin, Minnesota, with-out reported fly or odor
problems.
Ensilage
13
Chittenden reported successful ensilage and refeeding of a mixture of
paunch and ground cornstalks. A layer of cornstalks was put in a bunker
silo and paunch spread over the top. The mixture was compacted in the
silo. Several layers of cornstalk and paunch manure were used to fill
the bunker. Paunch was added to bring the mixture up to between 65 and
75 percent moisture. The cornstalks reached a low of 8 percent moisture
and considerably more paunch than cornstalks was used on a wet weight
basis. Tramp metal in the paunch can present a problem in refeeding,
but metal suspension with a magnet has been accomplished. Refeeding of
the material required a four to one ratio of cattle on feed to cattle
slaughtered per day.
Utilizing cornstalks in the silage restricts the operation to the annual
harvest season. To overcome this limitation ensilage of paunch with
sugar beet pulp pellets and corn was tried at a 7.5:1.5:1.0 ratio in a
bunker silo.13 The beet pulp expanded as it absorbed the paunch liquids
and broke out of the bunker silos a time or two. However, a more
serious problem was the limited acceptance by the cattle. The problem
was diagnosed as acidosis and solved by the addition of sodium bicarbonate
to the silage. Another packing company has proposed the ensilage process
utilizing paunch manure and grain (mainly corn) in closed vertical
silos. Feeding high moisture corn to feeder cattle is practiced to
improve feed conversion efficiencies. The vertical silo offers mixing
and handling equipment and a controlled atmosphere.
55
-------
Transferring technology developed for cattle manure ensilage offers
opportunities. Anthony has demonstrated ensilage of fresh animal
manure and ground grass hay in the ratio of 57:43 as a feed for ruminants.
Feeding trails have established the value of the silage when used in a
feed for fattening yearling steers.
Single Cell Protein Cultures
Bench scale experiments have been encouraging in conversion of food
processing waste into single cell protein for animal feeds. The processes
usually incorporate sterilization and inoculation with selected biological
strains followed by cell growth, cell separation, cell drying and incor-
poration in an animal feed. The potential of these processes comes from
the limited energy costs for cell growth. Sterilization when required,
oxygen input, and cell separation are the major technical or economic
constraints of the processes. Single cell protein conversion of paunch
manure has been accomplished in the laboratory using several strains of
Fungi Imperfecti. The larger fungus cells can be more easily separated
than bacterial cells. Technical development of a single cell protein
culture on animal manure has progressed to the point of a full scale
23
demonstration by a major corporation . None of the processes has been
demonstrated on paunch manure.
Digestion
The digestion of paunch manure was first reported by Boruff in 1933.
In a specially designed pilot plant he stabilized cow paunch manure fed
continuosly at a rate of 4.5 grams dry weight per day per liter (0.28
Ib/cu ft) of digester capacity. The stabilization of the material
furnished 1.3 volumes of combustible gas (61 percent methane)/day/tank
volume. The residues withdrawn at the end of the 122 day experiment
were not odorous but were very fiberous owing to the presence of undigested
56
-------
cellulosic material. The residues were 12 percent solids on a dry
weight basis and constituted 2/3 of paunch manure added. The results of
this experiment have been verified many times since 1933. Anaerobic
lagoons (digesters) which receive paunch manure are dredged after several
years of operation to remove the undigested cellulosic material in order
to restore detention times and removal efficiencies. Historically, the
value of the gas produced has not warranted the cost of its collection
from lagoons.
Board Mill
Production of building material has been explored with food processing
waste solids, pen manure and paunch manure. The production of wall board
under the trade name Celotex is produced in large quantities from
bagasse. Bagasse is a solid waste from the production of cane sugar.
One of the major packers developed a process for production of wallboard
from paunch manure. The process was never utilized. The wallboard
would give off an odor it if became wet which might occur with a leaky
roof or broken waterpipe. The economic size of a board mill required a
large concentration of packers which is no longer the case outside of
Omaha, Nebraska.
Summary
Paunch manure is a major waste (2.5 kg BOD5/1000 kg LWK) in beef processing
and is equivalent to 20 percent of the average waste load from a packing-
house. This percentage would be higher based on longer term oxygen
demand values as the BOD5 of paunch is less than 40 percent of its
carbonaceous oxygen demand.
Between 60 and 85 percent of the BOD in paunch manure is water soluble.
Use of the wet-dump handling system even with solids-liquid separation
57
-------
adds 2 kg BOD5/1000 kg LWK in the water carriage and significantly
increases the wastewater treatment costs. Because of these increased
costs, dry-dump handling is the system of economic choice.
The constraints in processing paunch manure are the water pollution
potential due to the high BOD, the production of odors and flies, the
high moisture content, and the low protein content. A number of processes
to utilize paunch manure have been investigated in the laboratory, in
pilot plants and at full scale. Of the processes reviewed, the production
of soil conditioners by surface and/or subsurface spreading and the
production of feeds by ensilage or drying appear to be the most feasible.
58
-------
References
1. Anonymous. Omaha Plans Paunch Manure Incinerator. Engr. New-
Record 173, 20, 59 (Nov. 12, 1964).
2. Anonymous. Feed Paunch Manure to Cattle - Meat Packers Told. Eng.
News. 1976, 149, April 7, 1966.
3. Anonymous. Treatment of Packing House Waste Problems. The National
Provisioner, 119, No. 25, 22-3, 26 (Dec. 18, 1948).
4. Anonymous. How Paunch Contents are Handled. National Provisioner
Volume 112, No. 22, P. 9 (June 2, 1945).
5. Anthony, W. B. Feeding Value of Cattle Manure for Cattle. 0.
Animal Science 30:274-277 (1970).
6. Boruff, C. S. Stabilization of Paunch Manures and Packing-House
Screenings. Industry and Engineer Chemistry, 25, No. 6, 703-6
(June 1933).
7. Baumann, D. J. Elimination of Water Pollution by Packing-House
Animal Paunch and Blood. EPA Water Pollution Control Research
Series, Report #12060 FDS 11/71.
8. Birkel, L. F., Jr. Meat Packing and Slaughterhouse Waste Disposal.
Master Thesis, University of North Carolina Library, Chapel Hill,
1949.
9. Bradney, L., Nelson, W. and Bragstad, R. E. Treatment of Wastes
from the Meat Packing Industry. Given in "Report of FSWA Boston
Meeting" Second and Final Installament, Water and Sewage Works, A7,
No. 1, p. 34 (Jan. 1950).
59
-------
10. Burd, R. S. A Study of Sludge Handling and Disposal. U.S. Dept.
of Interior, FWPCA, Publication WP-20-4 (May 1968).
11. Busnell, A. M. and Boruff, C. S. Mechanical Equipment for Continuous
Fermentation of Fibrous Materials. Industrial and Engineering
Chemistry, 25:147-9 (Feb. 1933).
12. Camin, K. Q. Cost of Clean Water. Vol. II, Industrial Waste
Profile No. 8: Meat Products, FWPCA, Nov. 1968.
13. Chittenden, J. A. Solid Wastes in the Meat Packing Industry. Iowa
Beef Processors, Inc. Dakota City, Nebraska (June 1972).
14. Coddling, J. H. Treatment of Abattoir Wastes. Nature, 146;9-12
(1940) British.
15. Eldridge, E. F. Industrial Waste Treatment Practices, pp. 265-82,
New York, 1942 (McGraw-Hill).
16. Eldridge, E. F. The Meat Packing Plant Waste Disposal Problems.
Michigan Engineering Experiment Station Bulletin 105, 47 pp,
December 1946. Reprinted in 5 articles National Provisioner, Feb.
23, March 9, March 30, April 27, and May 18, 1946.
17. Garner, William and Smith, Ivan C. The Disposal of Cattle Feedlot
Wastes by Pyrolysis. EPA-R2-73-096 (Jan. 1973).
18. Henningson, Durham and Richardson. Report on the Processing and
Disposal of Paunch Manure. Prepared for the City of Omaha, Nebraska
(1964).
60
-------
19. Horsefield, Brian. Drying Animal Waste with Solar Energy and
Exhaust Ventilation Air. American Society of Agricultural Engineers.
Paper 73-411 (June 1973).
20. Matsushima, J. K., Byington, Craig and Smith, Bill. Paunch Content
Bloodmeal Mixture as Protein Supplement in Feedlot Rations.
Colorado State University (1974).
21. National Provisioners, Inc. Annual Meat Packers Guide, 1946. p. 86
and Annual Meat Packers Guide, 1947, p. 92, Chicago.
22. Nell, J. H., Krige, P. R. The Disposal of Solid Abattoir Waste by
Composting. Water Research Pergamon Press, 1971, Vol. 5, pp. 117-
1189, (Britain).
23. Nolan, E. J. and Shull, J. J. Engineering Experiences during the
Demonstration Phase of a Nutrient Reclamation Plant. Reentry and
Environmental System Division G. E. Co. Presented at 75th National
Meeting AICE Detroit, Mich. June 1973.
24. Personal Communication with Mike Rudd,American Pollution Prevention
Co., Inc., Minneaplis, MN.
25. Procedyne Corporation, First Interim Technical Report - A Method of
Manure Disposal for a Beef Packing Operation for Environmental
Protection Agency Project 12060 EOF (Feb. 1971).
26. Reece, D. L., and Wesley, D. E. A Blood Meal-Rumen Contents Blend
as a Partial or Complete Substitute for Fish Meal in Channel Catfish
Diets. The Progressive Fish-Culturist. Vol. 37, No. 1, January
1975.
61
-------
27. Ruppert, R. W. Omaha to Use New Process for Packing House Wastes.
Water and Waste Eng. Vol. 4, p. 12 pp. 44-46 (Dec. 1967).
28. Smith, J. L. and Ralph C. Gald, Development of a Subsurface Injector
for Total Recycling of Sewage Sludge. Experiment Station Report
No. PR-72-42, Colorado State University, Nov. 1972.
29. Steffen, A. 0. What to Do About Paunch Wastes. Proceeding of the
Third Industrial Waste Conference, pp. 268-71, Purdue University
(1947).
30. Summerfelt, Robert C. and Yin, S. C. Paunch Manure as a Feed
Supplement in Channel Catfishing Farming. EPA Environmental
Technology Series, EPA-660/2-74-046. (May 1974).
31. U. S. Public Health Service Supplement D Industrial Wastes Guides
pp. 1145-57 Washington, 1944, (USGPO).
32. Wells, Louis, R. Waste Water Treatment with a Profit Potential.
Public Works, pp. 82-84, April 1970.
33. Witherow, Jack. L. Meat Packing Waste Management Research Program,
the National Provisioner, Vol. 164, No. 12, pp. 12-18, March 20,
1971.
34. Yin S. C. and Farmer, David M. Problems, Properties, Disposal
Practices and Potential Uses of Cattle Paunch Manure. American
Society of Agricultural Engineers, Paper No. 73-403.
35. Yin, S. C. and Witherow, Jack L. Cattle Paunch Contents as Fish
Feed Supplement: Feasibility Studies, Proc. Third Nat. Symp. Food
Processing Wastes, EPA-R2-018, 401-408.
62
-------
36. Yeck, Robert G. and Schleusener, Paul E. Recycling of Animal
Wastes. Proceeding of National Symposium on Animal Waste Management
Library of Congress Catalog No. 70-188504 (September 1971).
63
-------
VISCERA HANDLING
In pork slaughtering there is tremendous variation of how the
viscera is handled. The stomach, for example, in places is sent entirely
unopened into the rendering system. Where it is opened, the contents go
directly to the sewer and the membrane then goes to rendering. Such
variations bring about tremendous differences in in-plant waste recovery.
Presented here are the efforts of one plant in in-plant waste recovery.
Perhaps the biggest headache in viscera handling is the different
types of screens. The pork intestine, probably more so than beef is a
very difficult thing to handle. It has the ability to wrap itself
around mechanical equipment, to hang on, and to plug it up. This causes
back-up problems. In plants today viscera screens in some cases are not
used merely because of the plugging problems that were experienced in
the past.
A grease skimming device is used to handle flow from stomach wash,
chitterling wash, wash from the viscera pans, periodic wash of equipment,
tables and floors, and carcass rinse. Hot water in the scalding tub
should bypass the grease skimmer, as hot water dissolves the grease
making separation more difficult. Putting more inlet into the grease
skimmer gives the sewage more agitation. This agitation is maintained
to keep manure in suspension so it will go out with the effluent. The
settlings, which consists of pieces of intestines, the stomach, etc. and
the grease which is skimmed off the top are taken to rendering. A
mechanical flight system removes these materials from the tank.
In the plant every operation that contributes flow to the skimmer
is controlled either by curbing or by sizing the sewer line to limit the
64
-------
capacity. In making the skimmer work, it is critical that it never gets
flooded. The operations throughout the plant should keep a constant
flow to the sewer. When slugs of several hundred gallons of water are
released every few minutes is where the problem begins. In viscera
washing the flow must be controlled. It is best to keep the flow
constant and essential to prevent someone from pulling a plug and
discharging the flow which has accumulated for 30 minutes to an hour.
Wherever a batch vessel is dumped the sewer line size controls the flow.
The maximum flow capacity will come down the line to the skimmer. The
sewer line capacity should be controlled as it is the limiting factor on
removal efficiency in the skimmer.
The use of a sump prior to an air flotation unit was found critical
to removal efficiency. The sump was designed to receive effluent from
the grease skimmer, wastewater from the dehairing process after screens
and a recycle stream from the air flotation unit. This recycling keeps
the flotation unit operating 24 hours a day, which greatly increases
solids removed. The size of the flotation unit should be sized on
maximum flow that occurs during a five minute period. To size the unit
on an average flow results in floating grease and solids being carried
out with the effluent during maximum flows. However, low flow periods
then create an operation problem. The sump with a recycle stream
results in pumping a more constant amount to the flotation unit. Most
of the time the sump pump is recycling flow. The peak flow to average
flow is about 200 to 75 gpm which results in actually pumping to the
flotation unit 3 or 4 times the daily discharge volume.
An envisioned problem of plugging of the sump pump with toe nails
and material in the dehairing wastewater have not materialized. Problems
with flooding the sump have not occurred. Increased emulsification of
grease with the sump pump over a gravity system in the 32°C (90°F)
wastewater was speculated but unnoticed. The efficiency of removal was
65
-------
doubled by changing from a full flow pressurization to a pressurized
recycle.
In handling the wastewaters from viscera processing minimum flow
can creat a pumping problem. Centrifugal pumps are designed to efficiently
operate within narrow limits of capacity, speed and pressure. At minimum
flow, two things can happen. One, the pump will dewater and lose its
prime. To prime the pump can be difficult and time consuming. Second,
the discharge valve can be partially closed to reduce flow commensurate
with input flow. This allows solids to jam and pack the outlet and
pump. Recirculation of flow is simpler and increases in power costs
will be minimal at the optimum operating point of the pump. Other means
of handling low flows are variable speed pumps or multi-plumps with
autmoatic controls which increase pumping capacity with higher water
levels in the sump (wet well).
In the plant itself, the 82°C (180°F) water used on the viscera
line is off during 10 minute work breaks. Four fast acting valves shut
off water to the entire viscera operation. The concept used is that if
it takes work the waste water people aren't going to do it. To be
factual about it, all people take the path of least resistance. If the
employee is required to close five or six valves with ten or twelve
turns of a handle before going to break - it isn't going to happen.
Quick-acting valves to shut off the operation are simple and inexpensive.
Most of the water used in our plant requires work to get water. Automatic
shut off valves are used to keep water from running all the time. The
employee that runs the equipment, runs the water. For example, the
clean-up hoses have valves which shut off when the hose is released.
There is also a need for supervisory control to insure correct usage of
the water system.
66
-------
SECTION X
RENDERING
Monitored
by
Bill Prokop and Carl Immel
This section covers a basic despription of the batch cooker process
of the rendering industry and its relationship to odor control and waste
treatment of the plant effluent. Also included is a discussion of the
two continuous rendering systems: (1) the Duke system manufactured by
the Dupps Company in Germantown, Ohio and (2) the Carver-Greenfield (C-
G) system manufactured by Anderson IBEC. At the end of the section are
process flow diagrams which illustrate each of these three rendering
processes.
BATCH COOKER PROCESS
The rendering process consists essentially of two basic steps.
First, the raw material is heated and "cooked" to evaporate the moisture,
to melt the tallow or grease present in the raw material and finally to
condition the animal fibrous tissue. This conditioning process is
important to accomplish efficiently the second step, the separation of
tallow or grease from the solid proteinaceous material.
This basic process is known as dry_ rendering and the cooking
operation is performed with a horizontal, steam-jacketed cylindrical
vessel equipped with an agitator. The term dry rendering is used
because the raw material is "cooked" with no addition of steam or water.
This vessel is known as a batch cooker because it follows a repetitive
cycle: the cooker is charged with the proper amount of raw material,
67
-------
the cook is made under controlled conditions and finally the cooked
material is discharged.
The raw material collected by the renderer's trucks is discharged
to a receiving bin and then screw conveyed through a crusher or similar
device for size reduction. For batch cookers, the raw material is
reduced in size to 1 or 2 inches to provide efficient cooking which
normally requires 1 1/2 to 2 1/2 hours. The raw material is quite
variable depending upon the source and adjustments in the cooking time
and temperature required to properly process the material.
After the cooking process is completed, the cooked material is
discharged to the "perk" pan which allows the free run tallow to drain
and be separated from the protein solids which are known as "tankage."
After one or two hours of drainage, the protein solids still contain
about 25% tallow and are conveyed to the screw press which completes the
separation of the tallow from the solids. The solid protein material
discharged from the screen press, known as "cracklings", is normally
screened and ground with a hammer mill to produce a product that essentially
passes a 12 mesh screen. The tallow or grease discharged from the screw
press normally contains fine solid particles which are removed by centri-
fuging or filtration.
Odor Control
Regarding the basic rendering process, the primary sources of high
intensity odor result from the cooking and pressing operations because
the material in both cases is heated to temperatures over 104°C (220°F)
The age of the raw material is important because older material that has
deteriorated appreciably will result in substantially higher odors being
generated during the cooking and pressing operations.
68
-------
During the cooking process, the cooker exhaust essentially at
atmospheric pressure contains a high percentage of steam vapor and a
small amount of noncondensables. The steam vapors are removed by a
condenser and the noncondensables contain high intensity odors that
normally are treated. These noncondensables can range in odor intensity
from 5000 to 100,000 odor units (ASTM syringe method) depending on the
age of the raw materials and other factors affecting the cooking operations,
Currently, the barometric or direct contact condenser is being replaced
by either a shell and tube condenser or an air-cooled condenser to
minimize water usage and wastewater treatment costs.
An important consideration in developing an approach to achieve
control of odors is the ability of a particular process to confine the
odors within the equipment. Regarding the batch cooker process, the
odorous emissions from the cooking and pressing operations can basically
be confined and treated. However, the perk pan is open to the atmosphere
and cannot be effectively enclosed. The hot cooked material from the
batch cooker not only releases odor but also fat aerosol particles tend
to become airborne and deposit upon the building wall and floor surfaces,
requiring frequent cleanup.
Equipment should be checked frequently during the operation to see
that the separator is doing an effective job, the depth of the cooker
load and that the exhaust is removed efficiently. The condenser should
have adequate water supply, maintaining outlet temperature of 28 to 49°C
(100 to 120 °F) so that the noncondensable odors would tend to be
minimized.
There are two basic approaches to odor control systems; (1) confine the
high intensity odors and treat them by wet scrubbing or incineration;
(2) provide a plant ventilating scrubber system that treats all odorous
air within the plant. This latter method is considered to be a more
complete solution to the overall plant odor problem.
69
-------
Instead of providing an afterburner for incinceration with the
related additional capital and operating costs, it sometimes is feasible
to use the boiler firebox to incinerate low volume, high intensity odor
gases.
Wet scrubbing with chemical oxidant solutions is also used to
control high intensity odors. These solutions include the use of sodium
hypochlorite, chlorine, sulfuric acid, caustic soda and soda ash. A
combination of a venturi scrubber and packed tower scrubber is used for
high intensity odors. The venturi scrubber removes any solid particulate
or fat aerosol particles before passing to the packed tower scrubber
where the oxidation solution would be expended.
Regarding plant ventilating air scrubber, sufficient ventilating
air must pass through the operating area in the summer months to provide
sufficient worker comfort since it is desired to keep the doors and
windows closed to confine the plant odors within the building before
passing through the scrubber system. Plant ventilating air scrubbers
consist of two types: (1) packed tower scrubber systems; (2) multistage
horizontal banks of spray nozzles that direct a dense spray pattern
countercurrent to the air flow. Different chemical solutions are used
in the various stages.
Wastewater Treatment
Two sources of wastewater are produced in the basic rendering
process. The condensate resulting from the removal of steam vapor from
the cooker exhaust is one source. As was discussed before, the type of
condenser used will determine the volume of water required for condensing,
The air-cooled condenser of course requires no water for condensing.
The other wastewater source consists of the washwater used to clean the
plant and also to clean the raw material pickup trucks since these are
70
-------
required to be kept reasonably sanitary. Considerably more washwater is
usually needed in the batch cooker plant because there is a tendency for
more material spills and fat aerosol emissions that require more frequent
housekeeping. In the rendering industry, the use of mechanical skimmers
and dissolved air flotation cells is common for primary treatment to
remove grease and suspended solids and the use of aerobic lagoons for
secondary treatment is the usual arrangement.
CONTINUOUS RENDERING SYSTEMS
Continuous rendering has a number of inherent advantages over the batch
system. Because a continuous process has the ability to provide an
uninterrupted constant flow of material, its process variables usually
are more easily controlled and improved control of product quality
normally results. Further, the residence time in a continuous system is
much less, ranging between 30 to 60 minutes, and improved product
quality is obtained due to less exposure to heat. The continuous system
is essentially enclosed and is capable of confining the odors and fat
aerosol particles within the equipment. However, it must be recognized
that the reliability of all process equipment to operate continuously
without frequent breakdown and maintenance is an essential requirement.
It is important that a thorough preventive maintenance program be active
to keep the plant in operation.
Duke System
This system was designed to provide a method of cooker operation
similar to that of the batch cooker. The Equacooker is a horizontal,
steam-jacketed cylindrical vessel equipped with a rotating shaft to
which are attached paddles that lift and move the material horizontally
through the cooker. Steam heated coils are also attached to the shaft
to provide increased heat transfer. The Equacooker contains three
71
-------
separate compartments which are fitted with baffles to restrict and
control the flow of material through the cooker.
The feed rate to the Equacooker is controlled by adjusting the
speed of the variable speed drive for the Twin Screw Feeder which
establishes the production rate for the system. The discharge rate for
the Equacooker is controlled by the speed at which the control wheel
rotates. The control wheel contains buckets similar to those used in a
bucket elevator that pick up the cooker material from the Equacooker and
discharges it to the Drainor. Next to the control wheel is located a
sight glass column that visually shows the operating level in the
cooker. A photoelectric cell unit is provided to shut off the Twin
Screw Feeder when the upper level limit is reached.
The Duke control system essentially confines the odors within the
equipment. Recent improvements have been made to provide gasketed seals
and locate suction pickup vents for improved collection of odor emissions.
The basic odor control system consists of diverting the exhaust vapor
from the Equacooker to an entrainment separator to remove solid or fat
particles before passing to the Vapor Controller which condenses the
steam vapor by contacting the condenser tubes with room air. The Vapor
Controller also scrubs the plant ventilating air with water sprays
before being exhausted from the plant. Currently, the noncondensables
from the Vapor Controller and the odor emission from the Pressors is
routed to a wet scrubber entrainment separator to remove solid or fat
particles before being incinerated in the afterburner or boiler.
Anderson C-G system
The C-G continuous process is considerably different than other
systems. Tallow is recycled to carry the raw material as a pumpable
slurry instead of using screw conveyors. A secondary grinding step is
72
-------
used to further reduce the raw material particle sizes. A conventional
evaporator system with vacuum is used for moisture control.
Partially ground raw material from the Pre-breaker is fed continuously
by the Triple Screw Feeder at a controlled rate. The Fluidizing tank
receives this raw material which is mixed and suspended with the recylced
tallow at 104°C (220°F), and at a ratio of five pounds of tallow to each
pound of raw material. This slurry is pumped to Reitz disintegrators
for further size reduction from 1 inch to 1/4 inch pieces. This finely
ground slurry is then pumped to the evaporator.
The evaporator system consists of a verticle shell and tube heat
exchanger and a vapor chamber. The slurry of solids and tallow is
pumped to the top of the heat exchanger and the slurry flows by gravity
down through the tubes while steam is injected into the shell to provide
heat for moisture evaporation. The water vapor is separated from the
dried slurry in the vapor chamber which is under a vacuum of 26 to 28
inches of mercury. The water vapor is condensed with a shell and tube
condenser that is connected to a two-stage steam ejectory system with
hot well to provide the vacuum. In some cases, a two-stage evaporator
system is provided to obtain steam economy especially for raw material
with a higher moisture content.
Due to the vacuum provided during evaporation, the C-G system
operates at substantially lower temperatures than other systems. This
tends to reduce the intensity of certain odor emissions, particularly
the noncondensable that discharge from the hot well. In order to
confine the odors and fat aerosol particles within the system, it is
necessary that suction pickup vents be provided on the process tanks,
especially the fluidizing tank where the more volatile odors are emitted
as the raw material comes into contact with the hot recycled tallow.
The noncondensables and the odor emissions from the process tanks and
73
-------
the Expellers are normally collected and treated by incineration or wet
scrubbing.
74
-------
NON-CONDENSABLE GASES
01
Dead Stock Carcasses Shop Fat and Bone
«4». ________________-_^
ENTRAPMENT SEPARATOR
CONDENSER
RAW MATERIAL RECEIVING
Exhaust Vapor
Screw Press Vent
Unpressed
Tankage
SCREW PRESS
Steam - 25-75 PSI
PERCOLATOR
-DRAIN PAN-y-
Jacket Condensate
Free Run Fat
Screw Press Fat
PRECOAT
LEAF FILTER
PROTEIN
MEAL
STORAGE
HOPPER
CENTRIFUGE
CRUDE
ANIMAL
FAT
TANK
ANIMAL FAT
STORAGE
TANK
Solids to Screw Press
Figure 1. Batch cooker process
-------
VAPOR CONTROLLER
Condensing Tubes
Spray Nozzles
INCINERATOR
Blower
Blower
Vapor Inlet
RAW
MATERIAL
BIN
ENTRAINMENT
SEPARATOR
Condensables
Condensate to Sewer
TWIN SCREW
FEEDER
CENTRIFUGE
CONTROL
WHEEL
HOGGER
(CUTTER)
Tallow
Drainer
TALLOW
••••Ml
STORAGE
VARI-SPEED
DID DIP P
CRUDE TALLOW
TANK
Steam to Coils
EQUACOOKER
Crude Tallow
Pump
DUKE PRESSER
Steam to Jacket
Meal Cake to Grinding
Press Tallow
Fiqure 2. Duke continuous rendering system
-------
RAW
MATERIAL
BIN
Water
s
^
st
-r
earn .,„
EJECTOR
\s-
t V
MAIN
EVAPORATOR
Condensate
Reoiroulation Pump
Expeller Cake
to Grinding
Reoyale Tallow at 200° Farenheit
Expeller Tallow
To Tallow Storage
Figure 3. Carver-Greenfield continuous rendering system
-------
SECTION XI
PLANT CLEAN-UP
A major factor in the success of a clean-up operation involves the
cooperation of the employees. Unless they are made aware of the signi-
ficance of the way this operation is handled, a much higher water use
and wastewater load will be generated. Therefore, good housekeeping
practices must begin with a successful employee awareness program.
Several changes can be made to make the job easier for the employee,
thereby increasing the chances of getting cooperation. This includes
the use of more sophisticated equipment such as shut-off valves, foot
pedals, specialty nozzles, etc. These are changes that can easily be
instituted at minimal cost. A low-volume, high pressure water supply is
almost mandatory in the difficult areas. This can be supplemented by
the use of detergents when the need arises. An alternative to detergents
is the use of cleaning jell that is placed on the area to be cleaned
prior to rinsing. One arrangement that is said to lower water use is to
first scald the equipment using a detergent and then rinse with cold
water. A means of reducing water use without changes in operation is
simply by installing water gauges on the equipment. This makes the
employee aware of the amount of water that he is using and since there
is a gauge that will inform supervisory personnel also, he is motivated
to shut the water off when it is not needed.
78
-------
SECTION XII
APPENDICES
A. Water Conservation and Waste Control in a 80
Meat Packing Plant
B. Water Conservation and Waste Load Reduction in 90
a Modern Hog Packing Plant
NOTE: Appendices A and B are included with the
author's approval to show successful appli-
cation of the many ideas discussed and
reported in the previous sections.
Appendix B which was reviewed at the
workshop, is an excerpt from a prior
publication of the EPA, Region VII, Knasas
City, Missouri office.
79
-------
APPENDIX A
WATER CONSERVATION AND WASTE CONTROL
IN A MEAT PACKING PLANT
by
Lawrence D. Lively
John Morrell and Company operates two slaughterhouses in
Estherville, Iowa. The plants process 640 cattle and 2400 hogs per day
in respective plants. Primal cuts are produced and on-site rendering is
performed. Wastewater is discharged to the municipal waste treatment
plant after gravity sedimentation.
In 1971, the State of Iowa directed that the City of Estherville
upgrade the quality of discharge from the municipal sewage treatment
plant. The requirements, 10 mg/1 biochemical oxygen demand (BOD), 10
mg/1 suspended solids (SS), were consistent with stream classifications.
Before the directive could be complied with a 2 mg/1 ammonia nitrogen
(NH--N) effluent requirement was added.
The city engaged a consulting engineering firm to thoroughly
investigate means to comply with the State's directive. Review of
existing treatment facilities, waste water characteristics and the
discharge requirements resulted in recommendation to construct new
treatment facilities. The estimated cost was $4,900,000. The cost was
increased to $6,900,000 due to inflation and the need to comply with the
ammonia nitrogen standard.
John Morrell and Company had agreed to accept responsibility for
45% of the city's cost for the new plant based upon the lower estimate.
80
-------
The revised cost, however, was considered excessive. Alternatives,
therefore, were sought to reduce the company's commitment.
The most logical alternative was to reduce the strength and volume
of the slaughterhouse discharge. Typically, slaughterhouse wastewater
is high strength with BOD, SS, and Grease (HEM) ranging from 650-2200;
930-3000; 200-1000 mg/1 (1) respectively. Water use by slaughterhouses
per thousand pounds live weight kill (LWK) average 2650 liters (700
gallons) (2). Waste strength and volume from the two operations was a
major factor affecting the size of the new treatment plant. A program,
therefore, was developed to minimize the company's waste contribution
and thus reduce the cost of the proposed treatment plant.
Operational practices of the two plants were reviewed seeking means
to control strength and volume of wastewater. Analytical data showed
water use to be 4.96 m£d (1.31 mgd) or 8.8 m3 (1,060 gallons)/! ,000 Ibs.
LWK. It was apparent therefore, that a significant reduction in waste-
water volume was possible. The data also showed that the BOD was 11.8
kg/1,000 kg LWK compared to the national average 5.8 kg/1,000 kg LWK
(2). Other parameters were similarly higher than the national average.
Thus, it appeared that the strength could be reduced significantly. In
accordance with these conclusions, an in-plant waste control program was
devised to reduce the strength and volume of the waste water to an
acceptable level.
It was not considered practical to rely solely on the in-plant
waste control program to produce the desired degree of waste reduction.
Supplemental control through pretreatment processes would be necessary.
Dissolved air flotation, an industry standard, was selected as the basic
process. Further treatment was to be provided by a biological process.
81
-------
Guaranteed dissolved air flotation performance of 90% non-emusified
HEM and SS reduction was offered by an equipment manufacturer using
effluent recycle (3). Attendent BOD removal ranging 35-45% also results
in association with SS removal. An additional estimated BOD reduction
of 50% from a biological process was considered adequate pretreatment
(1).
The city's consultants were furnished projected values for reduced
waste strength and flow. Revised estimated cost of the proposed treatment
plan was $5,900,000. Treatment costs increased from 5.3<£/1000 liters
(20<£/1,000 gals.) to 6.3^/1000 liters (24
-------
13,400
1,400
4,800
4,200
3,000
100
10
36
31
23
10,500
4,200
5.700
4,400
5,000
100
40
54
+41
48
5,800
1,450
3,900
375
175
100
25
67
6
2
Table I. Waste Load Reduction
BOD SS HEM
Process Pounds Percent PbliTidT Percent PoUFidl Percent
Raw Waste
Housekeeping
Air Flotation
Trickling Filter
Effluent
Water Conservation: The Company's share of the revised cost of the new
municipal treatment plant was predicated on a flow of 4.5 mid (1.2 mgd).
The plant was originally sized to accept a 7.6 mid (2.0 mgd) flow from
the slaughterhouses to allow for increased production. In order to
justify the 4.5 mid (1.2 mgd) flow, a realistic water conservation
program had to be developed if the slaughterhouses were to have margin
for increased production.
Establish Conservation Attitude. A training program was developed
to re-educate personnel to the importance of using only the quantity of
water required for a job. The attitude that water was cheap and abundant
had to be dispelled and replaced with one reflecting total cost, i.e.,
initial charge, product loss through excess washing and the cost for
waste treatment. Hoses were not be left unattended, taps and sprays
should be turned off during breaks and other nonuse periods and press-
to-open valves must not be blocked open. Water use was reduced 3-5%
following such practices. To sustain any significant savings, it was
necessary to continually emphasize importance of the program.
Plant Clean-Up and Equipment. Clean-up operations generally use as
much water as that required for processing. Standard equipment is a low
pressure high volume hose discharging water at a rate of 0.6-1.3
83
-------
liters/sec (10-20 gpm) at temperatures of 60-82°C (140-180°F). A flood
of hot water is often believed to be necessary for cleaning equipment
and floors. In reality, that practice is counterproductive in that
equipment breakdown is greater and building erosion is accelerated. *
The higher cost of water and waste treatment has caused the packing-
house industry to use more modern and efficient cleaning methods. High-
pressure (500 psig) low-volume (3-5 gpm) cleaning systems are being used
increasingly. An area can be cleaned faster more effectively with less
water and cleaning chemicals. These units are being installed in areas
housing difficult to clean equipment. Although not yet realized, water
savings of 5-7% is expected.
Use of Sprays and Valves. At various points during processing the
product is washed by sprays. Conveying equipment such as viscera pans
are also washed and sterilized by sprays. Usually the sprays are left
on even though product has cleared that area or production has stopped.
To conserve water at such times automated solenoid valves will be
installed to open only when the product is in the wash area. Hand
washing of product requiring less than 50% under the spray time will be
equipped with press-to-open valves. Animal drinking water troughs will
be equipped with float operated valves. Hog sprays will be turned on
intermittently. Spray heads will be efficiently designed to improve
cleaning and to conserve water. This phase of the program has not been
fully implemented. Projected water savings is 5%.
Vapor Condensing System-Rendering Plant. The slaughterhouse
rendering operations produce grease or tallow, meat scraps and dried
blood. The process is conducted in steam jacketed, horizontally mounted
cylinderical units. During the cooking cycle the contents are continuously
agitated by paddles mounted on a motor driven center shaft. Depending
on size, the units are charged with 2.7-4.5 thousand kg (6-10,000 pounds)
84
-------
of offal or blood. Offal is 50-60% water (4) and whole blood is 82%
water (5). The units are generally operated under partial vacuum.
Steam pressure is 60-75 psig with condensate returned to the boilers.
Barometric condensers supplemented by steam ejectors were used to
draw off and condense water and other vapors resulting from the rendering
process. The plant has five offal melters and two blood dryers. All of
the units were equipped with barometric condensers. The barometrics on
the blood dryers used contaminated water for condensing. The offal
melter barometrics used potable water at a rate of 50-60 gpm per unit
(6).
Calculations indicated that about 363,000 Ipd (96,000 gpd) water
saving was possible by replacing all of the barometrics with a heat
exchanger condensing system. Added benefit from such a system was
production of hot potable water required for processing and clean-up
operations. Accordingly, an engineering firm was asked to design and
install a system based on the following description.
Collect vent gases using a manifold and route through an impingement
tank, heat exchanger and wet scrubber before exhausting to the atmosphere.
The impingement tank was to remove entrained solids. Provisions were
included for removal of condensate midway in the manifold, bottom of the
impingement tank and bottom of the heat exchanger. Pneumatic knife
valves were installed to allow each cooker to be isolated.
Ammonia condenser water at 20.5 liters/sec (325 gpm), (50-65°F) was
used as a feed to the heat exchanger. The heat exchanger effluent was
tied to the plant hot water system. During processing hours with the
rendering units operating, water temperature ranges 50-60°C (120 to
85
-------
140°F). The upper limit is controlled automatically with hot water
being dumped when temperature exceeds the set point. During clean-up
the set point is increased to 77°C (170°F) to produce the required
hotter water.
The system has been in operation for over six months. Results have
been very satisfactory. Table II shows average daily water and fuel oil
use before and after the system was installed. Processing time was also
decreased by about 15%.
Table II. Effect of Condensing System on Utilities
Time Period Hater Use Oil Use
1973 Old System 468,800 gpd 3,552 gpd
1974 New System 312,800 gpd 2,624 gpd
Avg. Daily Savings 156,000 gpd 928 gpd
Discussion
Waste Strength Reduction: Incremental reduction in waste strength
as a function of each segment of the waste control program could not be
determined without isolation of various process flows. Moreover,
various phases of the program were conducted simultaneously making it
imposible to determine the actual source of the reduction. A gross
effect, therefore, was compiled. Table III shows the reduction in waste
strength during the past two years.
Table III. In-Plant Waste Strenght Reduction
Date
1972
1974
% Reduction
86
BOD
13,400 Ibs.
11,300 Ibs.
16
SS
10,500 Ibs
7.700 Ibs
27
HEM
5,800 Ibs
4,150 Ibs
28
-------
The factors leading to the improved conditions was discussed in
previous sections. The inter-related effect of an effective dry clean-
up with decreased water use should be emphasized. A packinghouse
corollary is that waste strength is directly related to water use. Past
studies have shown that plants with high BOD, SS and HEM invariably are
high volume water users (7). Floor washing with hot water tend to
render meat particles with attendent break-up into finer pieces. Other
factors alluded to were the importance of disposing of unwanted organic
solid wastes to land fill rather than to the sewer.
HEM loss was emphasized over BOD and SS due to its value as a
saleable product. Although the factors mentioned above had a positive
effect on HEM losses, closer attention to operation of the rendering
plant was more effective. Losses were also less due to the new condensing
system.
Water Conservation. Water use throughout the plant was reduced
29%. Goals and accomplishments of the conservation program are shown in
Table IV.
Table IV. Water Conservation Program
Percent Reduction
GoaTAchieved
Obvious Waste 5
Equipment Modification 10 17
Clean-up Practices 5
Process Change 18 12
Projected 38 Metered 29
Water savings through correction of obvious waste practices,
equipment modification and altered clean-up practices could not be
measured separately. A gross improvement was reported instead.
87
-------
The 12% reduction achieved through process change was from only one
of the packinghouses. Thus, the process produced higher results than
expected. The calculations used to set the goal did not consider water
used when the barometric condensers were not needed. At the present
time, hot water is dumped if the demand is not sufficient to maintain
temperature below the set point. Plans are to install a hot water
reservoir to eliminate that loss.
Gross effect of the water conservation program resulted in reduction
of flow from 4.96 mid to 3.52 mid (1.31 mgd to 0.93 mgd). When all
facets of the program have been completed, anticipated water use will be
50% of the starting volume.
Summary
The in-plant waste control program has produced significant reduction
in strength and volume of the slaughterhouse discharge. Although the
dissolved air flotation units and the trickling filter are not yet
operational, experience has shown that the projected efficiency can be
readily attained. It can be stated with confidence, therefore, that the
program was realistic and will be successful.
References
1. Steffen, A. J. Water and Waste Engineering. C-l (May, 1970).
2. Pilney, J. P. et. al. American Meat Institute, 66th Annual Meeting
(Oct. 1971).
3. Field, L., EIMCO-BSP. Private communication.
88
-------
4. The Globe Co., Catalog No. 47, Engineering Section. 715.
5. Elimination of Water Pollution by Packinghouse Animal Paunch and
Blood. Beefland International, Inc., Council Bluffs, la. U.S. EPA
Water Pollution Control Research Series 12060 FDS 11/71.
6. All bright-Nell Co., Catalog 66-C, 40.
7. Camin, K. Q. Cost of Waste Treatment in the Meat Packing Industry.
25th Purdue Industrial Waste Conference, (1970).
89
-------
APPENDIX B
WATER CONSERVATION AND WASTE LOAD REDUCTION
IN A MODERN HOG PACKING PLANT
By Ronald Wantoch*, Stanley Lammers*, and
William Garner*
Region VII
Environmental Protection Agency
Kansas City, Missouri
*Respectively Chemical Engineer, EPA; President, Sioux-Preme
Packing Company, Sioux Center, Iowa; Research and Monitoring
Representative, EPA
90
-------
SUMMARY
The Sioux-Preme Packing Company plant in Sioux Center, Iowa,
represents a combination of unique design and good management. Inno-
vations introduced in all phases of the hog slaughter operation have
resulted in a savings of water, reduction of waste material generated,
and increased by-product recovery. The result is a greater profit
per animal and reduced waste treatment costs.
This efficiency is exemplified by process balance shown in
Table I. During the five-day study period, 97% of the live weight
kill could be recovered from various process operations. The 12.5%
represented by the inedible by-products provides an estimated profit
of 80 cents per hog.
The process water use, as measured by plant effluent, averaged
only 37.4 gallons per hog killed or 163 gallons per 1,000 pounds LWK.
This represents about one-fifth of the industry average and is
reflected in savings in power costs and in waste treatment. One of
the devices that is responsible for much of the water conservation is
the blood and scrap auger which transports inedible scrap to the proc-
essing area.
The auger and the other modified devices such as the stunner,
scald tank, hair scrapers, and singe chamber display the inventiveness
exercised in designing the plant process line. This unique equipment,
coupled with the fact that 54 of the 62 employees are engaged in the
production process, further demonstrates the concept of efficiency
incorporated in the plant.
91
-------
Collection and treatment of the in-plant wastewater is accom-
plished effectively. For example, the barometric condensers are used
to remove vapors from the rendering and blood drying process. Water
for the condensers is obtained from the anaerobic lagoon which elimi-
nates plant odors and places the waste load from the vapors in the
lagoon. The circulation of lagoon water mixes the anaerobic system
and the heat increases the microbial metabolism, increasing treatment
efficiency.
During the study period there was no discharge from the final
aerobic lagoon which provided the final polishing for the plant waste
stream. However, the treatment efficiency, as measured by waste load
reductions effected by the air flotation, anaerobic, and first aerobic
lagoons, was 97% removal of total suspended solids and 98% removal of
6005. There is no doubt that, in this situation, a profit motive is
compatible with environmental concerns.
92
-------
INTRODUCTION
The Sioux-Preme packing plant is located in northwestern Iowa
a few miles south of Sioux Center. The plant was built in 1969, is
privately owned, and operated by the owner. The production rate is
440,000#LWK/day at approximately 2,000 hogs per day. The plant
slaughters and processes by-products but does no meat processing.
The plant was visited several times in 1973 by EPA Regional
Office personnel, both to discuss discharge permits and research proj-
ects. During these visits, it became obvious that the design and
operation of the plant were exemplary and that a documentation of the
operation would be of value to other members of the meat packing
industry who were seeking to minimize water usage and effluent dis-
charge loads. Mr. Stanley Lammers has cooperated with the Environ-
mental Protection Agency in presenting the results of his work. The
survey was designed and conducted by personnel from the Region VII
staff, utilizing both the Kansas City, Kansas, Laboratory and EPA
Mobile Unit. Production data were supplied by Mr. Lammers.
93
-------
PLANT DESCRIPTION
The two-level Sioux-Preme plant (Figure 1) has an overall floor
space of approximately 25,000 square feet, with a space distribution
as follows:
Main Process Area
Carcass Chi 11 er
Pre-process Area
Util ities
La rd Renderi ng
Offal Package Room (chilled)
Offal Freezer
Inedible Grease Rendering
4,300 Sq. Ft.
4,200 Sq. Ft.
1 ,000 Sq. Ft.
1,800 Sq. Ft.
450 Sq. Ft.
600 Sq. Ft.
760 Sq. Ft.
1,600 Sq. Ft.
- -""". AD'
..
An unloading area, scale, and holding barn are located adjacent
to the process plant.
Two lagoons are located to the rear at a lower
elevation than the plant.
There is adequate acreage in back of the
lagoons for irrigation, if such an operation becomes advantageous.
Plant personnel total 62, with 54 engaged in the production process.
The plant is operated with a single shift of eight hours.
Plant main-
tenance time is equivalent to the full time of four people.
Four
USDA inspectors are assigned to full-time service at the plant.
On
interviews, their comments were favorable with water use reduction.
liThe USDA goal of assurance of a wholesome consumer product was com-
patible with the water conservation techniques employed in the plant.1I
94
-------
PROCESS FLOW
The pre-process flow is shown in Figure 2.
Hogs held in the
FIGURE 2
PREPROCESS AREA
SCALD TANK
TO SCRAPERS
BLOOD DRAIN
SLOPING BLEED AREA
SPRA Y
STICK
TABLE
RESTRA INER
WET
DOWN
FROM BARN
t
STUNNER
barn (Figure 3) are driven in groups of 20-25 to a wet down area
where they are sprayed for about 20 seconds with water from a low-
press ure spray.
They are then moved through a restrainer (Figure 4)
95
Fig.
3
~
-------
Fig.
4
Fig.
5
in which they are again sprayed with a low-pressure, continuous,
water stream immediately prior to stunning.
Stunning is accomplished
with a custom-built, low-voltage, high-amperage device which has a
low incidence of exploding vertebrae.
''jj!
...;
... -
The hogs are shackled and hung on an endless conveyor after
stunning.
The conveyor moves from the stick table (Figure 5), through
96
-------
a bleed area (Figure 6) for 10 minutes, then carries to an elevated
L-shaped scald tank (Figure 7).
This tank is heated by direct steam
injection which is controlled automatically.
Subsequent process flow
, C'~.
" ,
, .
. '
! 1,
, ,
I.
, " ~, .
.
.' ,
'. . '. .~
I ,
On emergence from the scald tank, the hogs move through two
scrapers (Figure 9) that have been modified to reduce water consump-
tion.
The rotating action of the scraper moves the hogs through
dehairing.
The conveyor emerging from the scald tank loops back to
the stick table.
When the hogs rollout of the scrapers, they fall on a slatted
conveyor bel t.
The hind legs are then cut to receive the gambrel
sticks (Figure 10) and are hung for eight minutes over the second
bleeding area (Figure 11).
97
Fig.
6
7
-------
FIGURE 8
PROCESS MEAT FLOW
HEART
STOMACH
CHITTERLINGS
HEAD MEAT
STOMACH
EMPTY &
RINSr
CONDEMNED
SCRAP CHUTE
I
HAIR
4- FROM SCALD TANK
SCRAPERS
98
-------
99
Fig.
9
Fig.
10
-------
Fig.
11
.,..
,.,
,
, ;~:1
. ,: I
,,~j,
, .
I,
100
-------
A second chain conveyor then engages the gambrel sticks and
carries the hogs into the singe chamber. Two shower head nozzles
wet the ears prior to singeing. Twenty-two fabricated nozzles, each
producing a brushy flame, are set alternately in a vertical line on
either side of the chamber and produce a curtain of flame through
which the hogs pass (Figure 12).
The carcass is polished with a single, long-rotating fiber brush
(Figure 13). The brush is set at an angle to the floor so that the
brush rotates the hog while polishing. The brush initially contacts
the hindquarters and, as the hog is dragged past the brush, contact
progresses to the front end of the hog. A slow continuous stream of
water drips on the hogs as they move past the polishing brush.
After mechanical polishing, the carcass is carried to an area
where a finish shaving is conducted manually. At this point eyelids,
hoofs, and hide scars are trimmed (Figure 14). The trimmings drop to
the floor. This area is manually scrapped every two and one-half
hours, and the trimmings are carried to the inedible scrap auger. If
the carcass does not meet house inspection standards and requires
additional trimming or complete rejection, it can be sidetracked.
Other sidetracks function to take up overrun from the scald tank, thus,
permitting an accurately timed scalding period. Hold up in this tank
could cook the carcass, in addition to loosening the hair.
The carcass is then rinsed by a high-pressure, low-volume spray
that employs 14 duckbill nozzles (Figure 15).
The head is then almost completely severed but remains with the
carcass. Heads are inspected by the USDA at this point. The next
101
-------
Fig.
12
13
Fig.
14
15
~I
. t
"
.~.
i f
102
....
s
-------
operation splits the brisket by hand.
Urinary and anal area trim
foll ows.
A trough placed under these two operations catches all
scraps, blood, and other drippings.
The trough is channeled to the
inedible meat chute via the auger.
Viscera are removed in the next operation (Figure 16).
The
\~
Fig.
16
viscera are dropped into a 24-inch square stainless steel pan.
The
pans have their separate conveyor belt that moves synchronous with
the originating carcass.
Viscera are inspected by the USDA at this
point.
Subsequently, the viscera and carcass move in separate paths.
The carcass is split by hand with a supported, weight-balanced cir-
cular saw (Figure 17).
The halved carcass is then further trimmed
and the leaf lard and kidneys are loosened.
A second carcass rinse
follows (Figure 18) with subsequent head, kidney, and lard removal.
After a final USDA inspection of the carcass halves, they are wrapped
and conveyed into the main chill room.
103
-------
Leaf lard on removal from carcass drops to a lower level where it
is rendered by standard processes.
The kidneys are rinsed, drained,
Heads, when dropped, are trimmed on a
and packaged separately.
separate table (Figure 19) that is equipped with a mechanical jaw
Fig.
17
Fig.
18
19
104
-------
separator.
Head trimmings then move to the packaging and freezing
room.
The viscera, in pans, follows another path.
liver, and diaphragm are separated (Figure 20).
Hea rt, pancreas,
The liver and pan-
creas are conveyed to the packaging room by chute (Figure 21) and
rinsed there.
The heart and diaphragm are stored in 30-gallon stain-
less steel barrels, batch-washed, and trucked into the packaging room.
~
.~
~.. Fig.
A"l'GC'\T ~
. 't- 20
. ,~ 21
-~..-:
~
.' »-
Lungs and gullets are dropped directly to storage at the lower level.
Lungs are sprayed for cooling periodically during storage.
Chi tter-
lings are sent via a trough to a special table for straightening
(Figure 22) and fed to a specially designed chitterling washer.
Stomach contents are dumped into the inedible scrap auger, and the
stomach is rinsed at this point (Figure 23).
The stomaches are
washed in a shortened version of a conventional beef stomach washer.
105
-------
Fig.
22
Fig.
23
/liP>
;#
106
-------
Hearts, washed stomaches, and washed chitterlings all go through
an additional scalding or "bleaching" in the mechanical washer shown
in Figure 24.
The bleaching solution contains considerable salt.
prevent slug discharge from the washer, it is surrounded by a curbing
and the contained area has a small drain.
In accordance with USDA regulations, wastewater discharging
from the chitterling washer, the stomach rinse, the stomach washer,
and the viscera separation table discharges to a separate drain that
must drain freely at all times without forming a pool on the floor.
..-
After all usable organs are taken from the viscera pans, the
remaining viscera are dumped in the inedible scrap chute and the
pans cycle back under the pan conveyor.
Here, pans are first rinsed
with a cold spray from six duckbill nozzles; next sprayed with hot,
120 PSIG water from eight nozzles; and again sprayed with cold water
from four nozzles.
107
To
Fig.
24
-------
A key feature of the plant design and management is the system
(Figure 25) for handling scraps, blood, and other fluids that are
destined for animal feed (inedible scrap). A 40-foot long, 12-inch
auger parallels the viscera pan conveyor. This empties into an
FIGURE 25
OIL AND MEAT BY-PRODUCTS FLOW
1
FLOTATION UNIT /"*\
SKIM \*J C°
^^3
— ^
r
^ , l\ —
DKER ) ^ J
_«/ VAPOR
V
^
RECYCLE
EXPELLER
PRESS
fe h
^ FLOT
— ^ —
l i
LAGOON
ATION
* GREASE
t SOLIDS
-, MEAT & BONE MEAL
T STORAGE
O
O
O
FINAL STORAGE
HAMMER MILL
108
-------
inedible scrap chute that dumps into a holding tank at the lower
level. Added to scraps carried by the auger are trimmed skulls,
rejected viscera, other trimmings, and whole carcasses, if they are
rejected. Inedible scrap from the holding tank is passed through a
rough grinder or "prebreaker" and then to a blow tank that is used
to fill the two inedible dry cookers. The cookers are evacuated by
barometric condensers that operate on recycled anaerobic lagoon water.
Inedible oil is expressed from the cooked scrap, after which the scrap
is cooled and passed through a hammer mill and stored as "meat and
bone meal."
Skimmings from the air flotation unit are cooked and dried
separately in vacuum. Flotation grease is expressed from the solids,
and remaining solids are incorporated with the inedible scrap prior
to milling. Vapor from the grease cooker is condensed by recycled
water from the anaerobic lagoon. This grease is sold as an animal
feed additive.
109
-------
BLOOD PROCESSING
The overall scheme for blood processing is shown in Figure 26.
The stick table (Figure 5) and primary bleeding area are sloped to
a common drain. The drain flows into a holding tank with a capacity
of 1,000 gallons (equivalent to 1,200 hogs). The trough from the
secondary bleeding area drains into a 5-gallon bucket (Figure 11)
that is manually emptied into the blood drain, as necessary.
Whole blood is pumped from the holding tank into one of two
FIGURE 26
BLOOD PROCESSING
. MAIN
BIOOD DRAIN
HOLDING
TANK •
blood cookers and dryers (Figure 27) in batches. The cooker is
filled to capacity. The moisture is removed while heating under
vacuum and then additional raw blood is added without emptying.
Cooker capacity is about 300 gallons and 30 to 45 minutes are required
for processing each fill.
After drying the blood is transferred to a 22-ton overhead
storage bin outside the building. The bin can be emptied by gravity
into trucks.
110
-------
i
!
'"
m
~
1:"":"...;;;... - -- - I': ~ ....................
fi""'- ..:!I'-- ... e-
..
...-..a
111
Fig.
27
-------
PROCESS BALANCE
During the five-day period of study 9,620 hogs were processed.
Average daily live weight was 441,141 pounds. Live weight is weight
on delivery to the slaughterhouse and does not reflect the estimated
5% weight loss on holding without feed prior to slaughter.
The main product is hanging, dressed, halved carcasses with hide
intact sans head. Dressed carcass weight averages 73.1% of live
weight. Other products sold for human consumption are organs, tongues,
head trimmings, and rendered lard. Organs are shipped frozen. All
other by-products find a market as animal feed or inedible grease.
Lungs and gullets are sold separately as wet, inedible products.
The skull and other trimmings, as well as any rejected organs
and carcasses, are ground, cooked, and dried. Blood is cooked and
dried separately. Inedible grease includes trimmed fat, grease from
the meat and bone meal cooker, and grease concentrated by the grease
skimmer and the air flotation unit. Some cooked grease is intention-
ally hauled to the anaerobic lagoon to function as a cover. Process
flow is carefully measured daily. Table I lists the weight balance
over the five-day study period.
112
-------
TABLE I
PROCESS BALANCE
Height (Ibs.) Percent
Dressed Carcass Weight 322,801 73.2
Other Edibles 19,478 4.4
Lard (Edible Oil) 7,199 1.6
Meat and Bone Meal 11,518 2.6
Inedible Grease 8,639 2.0
Dried Blood 2,880 0.7
Moisture Evaporated from Blood 18,370 4.2
Moisture Evaporated from Meal* 13,608 3.1
Live Barn Shrink* 22,057 5.0
Sewered Wastes* 1.551 0.4
428,101 97.04
Live Weight Killed 441,141
*Estimated
113
-------
VALUE OF BY-PRODUCT RECOVERY
The cost analysis shown in Table II demonstrates the value of
inedible by-product recovery. Of the live weight of the hog, 12.5%
is recovered as profitable product for nonhuman consumption. Added
to the sale price of this product would be the nondisposal benefits.
TABLE II
PRODUCT PROCESS COST FOR INEDIBLES
(Cents Per Head)
GAS ELECTRICITY
Inedible Oil
Meal
Blood
1.31
1.31
0.93
3.55
0.45
0.60
0.37
1.42 =
The cost of disposal by landfill is estimated at $4.75/ton or
6.8 cents per hog for the undried material. Thus, dry blood at
$155/ton, inedible oil at $146/ton, and meal at $135/ton bring an
additional $0.85 per hog on the market. Net profit on this operation
is estimated at $0.80 per hog as follows:
Sale Price For Inedibles $0.85/Hog
Operating Costs -$0.05
Capital Costs -$0.05
Maintenance Costs -$0.02
Non-Disposal Benefit $0.07
NET PROFIT $0.80/Hog
114
-------
WATER SUPPLY
The plant is supplied with process water from two wells located
approximately 600 feet from the plant and 100 feet apart. Water is
drawn from them alternately. The well water, as drawn, meets PHS
standards. Boiler water is softened, the remainder receives no
additional treatment.
The inlet water is restricted to limit flow to a maximum of
275 gal/min. At an average line pressure of 35 psi, the water use
per eight-hour shift is limited to 150,000 gal/day. Prior to dis-
tribution in the plant, the inlet water is used as a heat sink for
the refrigeration system.
Process water use is minimized through recirculation and con-
servation practices within the plant. During the five-day study,
period process effluent averaged 37.4 gallons per hog killed or 163
gallons per 1,000 pounds live weight kill. The daily process effluent
balance is shown in Table HI.
115
-------
TABLE III
WASTEWATER BALANCE
TEST
DAY
1
2
3
4
5
Average
HOGS
PROCESSED
PER DAY
2280
1624
1219
2158
2339
1924
10001
LWK
507.9
379.7
272.9
501.1
544.1
444.1
PLANT
EFFLUENT
1000 6PD
81
69
51
71
80
70.4
EFFLUENT
PER HOG
GALLONS
35.5
42.5
41.8
32.9
34.2
37.4
EFFLUENT
PER 1000#
LWK-GAL
159
182
187
142
147
163
116
-------
SPECIFIC DEVICES
Stunner - This custom-built device employed a low-voltage,
high-amperage charge for stunning. A key feature is the large area
of contact for the electrodes. As a consequence of the low-voltage,
the incidence of exploding vertebrae is very much decreased.
Scald Tank - The L-shaped scald tank is approximately 70 feet
long, 4 feet wide, and 2 1/2 feet deep (Figure 7). The conveyor
belt drags the hog into the tank and two power actuated dunkers sub-
merge the hogs. The tank is heated by 11 direct steam jets that are
controlled by a thermostat. There is a continuous water feed to the
tank that causes sufficient overflow to prevent scum buildup. Sanfax
Hog Scald (Oxford Chemical Company) is added to the tank at the rate
of 36 to 50 Ibs/day. The rate of addition of chemical is matched
with the seasonal variation in hog hair growth.
Hair Scrapers - Two commercial hog scrapers have been modified
to minimize water consumption. These rotating drums usually operate
with a flood of water. At this plant a high-pressure, low-volume
spray is employed. The drums are equipped with a two-speed drive, one
speed for operation and a lower speed to facilitate cleaning (Figure
9).
Singe Chamber - Two metal panels, about six feet wide, run from
floor to ceiling in the singe chamber. They are placed three feet
apart and at the top are covered with a metal hood that vents to an
outside stack. A series of 22 fabricated gas jets are placed, 11 on
each side to produce a curtain of flame through which the hogs pass.
The jets were fabricated from black, iron pipe.
117
-------
Carcass Polisher - Hogs move past a single 24-inch diameter
brush, 150 inches long, which is set at a 30-degree angle to the
floor and a 10-degree angle to the conveyor (Figure 13).
Condemned Scrap Auger - A key feature of the plant design is
a centrally located auger that mechanically carries all scrap from
the kill floor to a holding bin at the lower level without use of
water.
This is shown with covers removed in Figure 28.
All t ri mmi n gs
and rejected products can be placed directly into the auger from the
work location or are carried by chute to the auger.
The ki 11 floor
is dry scraped every two and one-half hours and before daily wash
down with the scrapings added to the auger (Figure 29).
Fig.
28
29
'"
Duckbill Nozzles - All rinse devices employ the high-pressure
spray produced by the duckbill nozzles shown in Figure 30.
Shutoff Valves
- All hand-operated washes are controlled by
118
-------
automatic shutoff valves such as shown in Figures 31 and 32.
Wash
down hoses have in-line "kink" valves that shut off flow automatically
when the hose is dropped.
Figure 33 shows how the cleanup man must
take positive action to operate the hose.
Stomach Washer -
This device is a cut down version of the com-
mercial beef stomach washer with a reworked spray system (Figure 34).
Chitterling Washer - This device was custom-built according
to Mr. Lanmer's desi'gn (Figure 35).
minute.
Water use is only 40 gallons per
-
--
I', ,.1
.~1:". ..
'".', /
" /
--; wC' ;;'H ,'"
Primary Skimmer - A skimmer with trapezoidal vertical cross
section is equipped with a drag conveyor as shown in Figure 36.
Inlet is slightly submerged and the outlet at the opposite side from
the inlet is medially placed.
Surface overflow rate is 2,000 to
3,000 gallons per square foot per day.
* NOTE:
All measurements are approximate.
119
Fig.
30
31
32
-------
Fig.
33
Fig.
34
.
,
;
, -
~4 'IIIIi ...--.
..
- .
120
-------
GREASE TROUGH
-T
WIDTH
FREE - BOARD
...
SOLIDS AUGER
OOUTLET
DRAG CONVEYOR
74"
_J
111
67"
72"
2"
,.
109"
..'
: side view
FIGURE 36
SCHEMA TIC FOR PRIMARY GREASE SKIMMER
121
Fig.
35
-------
KILL FLOOR
(main process)
SUMP
DEHAIR PROCESS
LOWER
LEVEL DRAINS
BARN
UTILITIES
AND
PREPROCESS
AREA
AEROBIC
LAGOON
PARSHALL
FLUME
= Sample Site
FIGURE 37
WASTE WATER FLOW
VAPOR FROM
COOKER & DRYER
122
-------
WASTEWATER FLOW
37.
Manure, as well as wash from the barn, is retained separately
Wastewater flow in the plant is depicted schematically in Figure
in a sump from which it is periodically hauled by a IIhoney wagonll to
adjacent fields.
The pre-process area is sewered directly into the
anaerobic lagoon.
Also sewered directly is the blood pump cooling
Fig.
38
water, wastewaters from the gambrel stick wash (Figure 38) and rinse
area, and drainage from the utilities area.
The drainage water
includes boiler blowdown and zeolite regeneration waters.
Lavatory
wastes pass through a septic tank and then flow separately to the
anaerobic lagoon.
123
-------
All drainage from the kill floor passes through the grease
skimmer (Figure 36). This includes two carcass rinses, stomach wash,
chitterling wash, and wash from the viscera pans, as well as periodic
flushing of equipment, tables, and floors. Effluent from the sub-
merged outlet of the grease skimmer flows by gravity to the main sump.
FIGURE 39
MAIN SUMP
BAFFLE
Influent from
Grease Skimmer^
To Flotation '
—DIVIDER
— water level — — —
Overflow to Lagoons
Flotation Return
The sump also collects drainage from the dehairing process after
screening and drainage from the lower level drains. The latter
includes spray used to wet down lungs and wash down from lower level
equipment. The cylindrical sump is divided into two sections that
function to buffer flow. See Figure 39 for the design. Note that
recycle from the air flotation unit is used to keep up the level of
sump and, hence, a constant flow to the air flotation unit.
124
-------
The air flotation unit, shown in Figure 40, is a standard Infilco
uni t.
Approximately 20% of the effluent flow is used to dissolve
0.75 scfm of air, and the remainder of the effluent returns to one
section of the main sump where it either functions as a flow ballast
for the input to the flotation unit or overflows into the main sewer.
An addi tional
collector has been installed in the main sewer
-
- ,.
:: "'1(~
"
; r
. ~ u
-
I,
Fig.
40
'i;~
,...
'"
:.t
:, .
line.
It is periodically emptied manually.
There are two anaerobic lagoons (Figure 41), each covering one-
half acre.
They are 18 feet deep with 3 feet of free board.
Each
lagoon can hold 1.2 million gallons or the equivalent to about two
weeks flow.
The lagoons were originally designed on an expected 2.0
pounds of BOD and a hydraulic loading of 240 gallons per head.
Design
125
-------
Fig.
41
BOD reduction was at 85% on a detention of 5.6 days.
Actual detention
time is 27 days and BOD reduction achieved is 92%.
The two lagoons
are piped in parallel and operated simultaneously except in case of
lagoon malfunction.
The effluent from the lagoons is recycled by a
600 gpm pump through the barometric condensers, completely circulating
the lagoon supernatant at a rate of once every 2.3 days.
Combined effluent from the two anaerobic lagoons then flows into
two sequential oxidation ponds.
The first, with a design load of 40
pounds BOD/acre, covers 11.7 acres; the second, with a design load of
35 pounds BOD/acre, covers 3.3 acres.
Each is 6 feet deep.
Actual
performance data during the period of study showed the load on the
first lagoon to be 7.8 pounds BOD/acre with an 80% efficiency at a
126
-------
detention time of at least 321 days. There was no effluent discharge
from the aerobic lagoons at the time of the study.
A spray irrigation system is being constructed that will permit
the use of final effluent on adjacent corn and alfalfa fields.
This provides the option of disposal of effluent by either irrigation
or discharge to the nearby creek.
A key feature in plant operation is a single individual who
reports directly to management and has authority to take immediate
action in problems of water and wastewater use and processing.
Seven wastestream sampling stations were selected to characterize
the wastewater flow. These stations were:
1. Wastewater from the kill floor.
2. Effluent from the grease skimmer.
3. Effluent from the main sump.
4. Total plant effluent.
5. Anaerobic lagoon effluent.
6. First aerobic lagoon contents.
7. Second aerobic lagoon contents.
The sampling stations are shown on Figure 37 and analytical data
are shown in Tables IV through XIV with a summary of the raw waste load
on Table XV.
127
-------
Table IV
BIOCHEMICAL OXYGEN DEMAND
Test
Day
3
3
3
3
4
4
4
4
5
5
5
5
Sample
Station
2
4
5
6
2
4
5
6
2
4
5
6
Flow
1000 GPD
18
51
51
51
32
71
71
71
35
80
80
80
BOD
MG/L
1750
1920
133
24
1670
1610
170
30
2300
2400
150
36
BOD
#/Hog
0.22
0.67
0.05
0.008
0.21
0.44
0.05
0.008
0.29
0.69
0.04
0.01
BOD
#/1000#LWK
0.96
2.99
0.21
0.04
0.89
1.90
0.20
0.04
1.23
2.94
0.18
0.04
128
-------
TABLE V
CHEMICAL OXYGEN DEMAND
TEST
DAY
1
1
1
2
2
2
3
3
3
4
4
4
5
5
5
SAMPLE
STATION
4
5
7
4
5
7
4
5
6
4
5
6
4
5
6
FLOW
1000 6PD
81
81
81
69
69
69
51
51
51
71
71
71
80
80
80
COD
MG/L
2760
316
81
2397
392
138
2431
262
66
2183
276
91
2547
270
95
COD
f/HOG
0.82
0.094
0.024
0.85
0.14
0.049
0.85
0.091
0.023
0.60
0.076
0.025
0.73
0.77
0.27
COD
1/iooofl.MK
3.67
0.42
0.11
3.64
0.59
0.21
3.79
0.41
0.10
2.58
0.33
0.11
3.13
0.33
0.12
129
-------
Table VI
TOTAL SOLIDS (TS)
Test
Day
1
1
1
1
1
2
2
2
2
2
3
3
3
3
3
4
4
4
4
4
5
5
5
5
5
Sample
Station
2
3
4
5
7
2
3
4
5
7
2
3
4
5
6
2
3
4
5
6
2
3
4
5
6
Flow
1000 GPD
34
55
81
81
81
24
55
69
69
69
18
55
51
51
51
32
55
71
71
71
35
55
80
80
80
TS
-MG/L
2150
1990
2230
1150
830
1860
4190
1650
1130
884
1710
3750
3390
1110
826
2480
2320
1540
1160
1060
2220
1850
2050
1130
1060
TS
I/HOG
0.27
0.40
0.66
0.34
0.25
0.23
1.18
0.59
0.40
0.31
0.21
1.41
1.18
0.39
0.29
0.31
0.49
0.42
0.32
0.29
0.28
0.36
0.59
0.32
0.30
TS
l/IOOOILMK
1.20
1.80
2.97
1.53
1.10
0.98
5.07
2.50
1.71
1.34
0.94
6.31
5.29
1.73
1.29
1.32
2.13
1.82
1.37
1.25
1.19
1.56
2.52
1.39
1.30
130
-------
Table VII
TOTAL SUSPENDED SOLIDS (TSS)
Test
Day
1
1
1
1
1
2
2
2
2
2
3
3
3
3
3
4
4
4
4
4
5
5
5
5
5
Sample
Station
2
3
4
5
7
2
3
4
5
7
2
3
4
5
6
2
3
4
5
6
2
3
4
5
6
Flow
1000 GPP
34
55
81
81
81
24
55
69
69
69
18
55
51
51
51
32
55
71
71
71
35
55
80
80
80
TSS
H6/L
1030
960
665
78
18
870
2440
570
64
50
690
2550
720
66
16
1110
1020
546
64
16
780
800
600
72
18
TSS
»/HOG
0.13
0.19
0.20
0.023
0.005
0.11
0.69
0.20
0.023
0.018
0.085
0.96
0.25
0.023
0.006
0.14
0.22
0.15
0.018
0.004
0.097
0.16
0.17
0.021
0.005
TSS
l/IOOOILHK
0.58
0.87
0.89
0.10
0.023
0.46
2.95
0.86
0.097
0.076
0.38
4.29
1.22
0.10
0.024
0.59
0.93
0.64
0.076
0.019
0.42
0.67
0.80
0.096
0.024
131
-------
TABLE VIII
TOTAL VOLATILE SOLIDS (TVS)
TEST SAMPLE FLOW TVS TVS TVS
DAY STATION 1000 GPP MG/L #/HOG I/1000ILWK
1
1
2
2
3
3
4
4
5
5
4
5
4
5
4
5
4
5
4
5
81
81
69
69
51
51
71
71
80
80
HV^VHVUH^HB
mo
202
856
192
1050
196
690
226
1190
202
^•^•^••^•MMI*
0.33
0.06
0.30
0.068
0.366
0.068
0.189
0.081
0.33
0.058
1.47
0.27
1.3
0.27
1.63
0.31
0.814
0.267
1.46
0.247
132
-------
Table IX
VOLATILE SUSPENDED SOLIDS (VSS)
Test Sample Flow VSS VSS VSS
Da£_ Station 1000 GPP MG/L I/HOG f/lOOOILHK
1 5 81 52 0.013 0.070
2 4 69 420 0.14 0.63
2 5 69 48 0.017 0.072
3 4 51 510 0.17 0.79
3 5 51 52 0.018 0.08
4 4 71 390 0.10 0.46
5 4 80 460 0.128 0.56
133
-------
Test
Hav
wQV
1
1
1
1
1
1
2
2
2
2
2
2
3
3
3
3
3
3
4
4
4
4
4
4
5
5
5
Sample
Station
^ I#CL ^ 1 v 1 1
1
2
3
4
5
7
1
2
3
4
5
7
1
2
3
4
5
6
1
2
3
4
5
6
2
3
4
Flow
1000 GPD
34
34
55
81
81
81
24
24
55
69
69
69
18
18
55
51
51
51
32
32
55
71
71
71
35
55
80
Table X
OIL AND GREASE
Oil & Grease
MG/L
90
98
134
188
14
.•\
< \
406
383
352
139
20
2
574
231
461
293
19
5
341
446
826
90
11
4
452
459
891
Oil & Grease
#/HOG
0.01.1
0.012
0.027
0.056
0.004
0.05
0.047
0.10
0.05
0.007
0.0007
0.03
0.028
0.17
0.10
0.006
0.0017
0.04
0.055
0.18
0.02
0.003
0.001
0.05
0.09
0.25
Oil & Grease
#/1000#LWK
0.05
0.055
0.12
0.25
0.019
0.21
0.20
0.43
0.21
0.03
0.003
0.14
0.127
0.75
0.46
0.03
0.0078
0.18
0.24
0.76
0.106
0.013
0.005
0.24
0.39
1.09
134
-------
TABLE XI
OIL AND GREASE
Average
Average
Average
Average
Average
Average
SAMPLE
STATION
1
2
3
4
5
6 & 7
FLOW
1000 GPD
27
27
55
70
68
68
OIL & GREASE
MG/L
353
322
446
320
16
2.8
OIL & GREASE
#/HOG
0.033
0.038
0.11
0.095
0.005
0.0009
OIL & GREASE
#/1000#LWK
0.145
0.17
0.49
0.42
0.023
0.004
135
-------
Table XII
TOTAL KJELDAHL NITROGEN (TKN)
Test
Day
-TjrSir
1
1
1
1
1
2
2
2
2
2
3
3
3
3
4
4
4
4
4
5
5
5
5
5
Sample
Station
4V^MBW^B^BW--»
2
3
4
5
7
2
3
4
5
7
2
3
4
6
2
3
4
5
6
2
3
4
5
6
Flow
1000 GPD
34
55
81
81
81
24
55
69
69
69
18
55
51
51
32
55
71
71
71
35
55
80
80
80
TKN
HG/L
116
132
122
142
4.2
100
105
116
115
5.0
102
153
109
4.5
98
133
106
116
5.8
94
136
117
115
5.8
TKN
I/HOG
0.014
0.027
0.036
0.042
0.001
0.012
0.030
0.041
0.041
0.002
0.013
0.058
0.038
0.002
0.012
0.028
0.029
0.032
0.002
0.012
0.027
0.023
0.033
0.002
TKN
0.065
0.119
0.162
0.189
0.006
0.053
0.127
0.176
0.174
0.010
0.056
0.257
0.170
0.007
0.052
0.121
0.125
0.137
0.007
0.050
0.115
0.098
0.141
0.007
136
-------
TABLE XIII
BACTERIA COUNT
(5-DAY AVERAGE)
SAMPLE
STATION
6
5
4
FECAL COL I FORM
MF/100ML
186
419 x 103
25 x 106
FECAL
STREPTOCOCCI
MF/100ML
440
144 x 103
3 x 106
TABLE XIV
NUTRIENTS IN OXIDATION POND (AEROBIC LAGOON)
NUTRIENTS (MG/L)
TEST
DAY
1
2
3
4
5
AEROBIC
LAGOON
2nd
2nd
1st
1st
1st
TKN
4.2
5.0
4.5
5.8
5.8
N02-N03
3.1
2.3
2.0
23
23
V
0.7
1.2
0.8
2.0
3.1
TOTAL
P
1.0
—
—
2.0
—
Phosphate analyses of two samples
of plant effluent averaged 19.4 MG/1 - P
137
-------
TABLE XV
SUMMARY OF PLANT EFFLUENT ANALYSES
(SAMPLE STATION #4)
ANALYSIS
BOD COD TS TSS TVS VSS TKN O&G
Cone., MG/L 1976 2464 2172 618 979 445 114 320
Per Hog, #'s 0.61 0.77 0.66 0.19 0.30 0.14 0.035 0.095
Per 1000#LWK,#'s 2.61 3.36 2.87 0.88 1.33 0.61 0.151 0.42
138
-------
TECHNICAL REPORT DATA
(flease read Inuructions on the reverse before completing)
EPA-600/2-76-214
3. RECIPIENT'S ACCESSION-NO.
FLE
WORKSHOP ON IN-PLANT WASTE REDUCTION IN THE MEAT
INDUSTRY
5, REPORT DATE
September 1976 (Issuing Date)
6. PERFORMING ORGANIZATION CODE
AUTHOR(S)
Compiled by Jack L. Witherow & James F. Scaief
8. PERFORMING ORGANIZATION REPORT NO.
3. PERFORMI
\DDRES
Food & Wood Products Branch
Industrial Environmental Research Laboratory-Cinti.
200 S.W. 35th Street
Corvallis, Oregon 97330
10. PROGRAM ELEMENT NO,
1BB610
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
Industrial Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
EPA-ORD
15. SUPPLEMENTARY NOTES
Proceedings on workshop held at University of Wisconsin. Madison, December 13-14,
1973
16. ABSTRACT
Presented are the proceedings of a workshop on in-plant waste reduction
in the meat industry. Forty-five participants from industry, government,
and private firms exchanged ideas and experiences on waste reduction during
the two-day session. Topics covered were: pens, blood conservation and
processing, paunch and viscera handling, .rendering and plant clean-up operations.
Case histories are presented on water conservation in a meat packing plant
and in a hog processing plant.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
industry,
c. COS AT I Field/Group
Food processing, Reviews, Industrial
wastes, Industrial water, Byproducts
*Food processing
Meat-packing industry,
In-plant waste reduction,
Rendering, Blood conser-
vation, Blood processing,
Paunch handling, Viscera
handling. Pens, Eviscer-
ating, Edible offal
13B
8. DISTRIBUTION STATEMENT
Release to public
EPA Form 2220-1 (9-73)
ft U.S. GOVERNMENT PRINTING OFFICE: 1976-657-695/6101 Region No. 5-11
FIT SECURITYTCLASS (This Report)
UNCLASSIFIED
21. NO. OF PAGES
149
20. SECURITY CLASS (Thispage)
UNCLASSIFIED
22. PRICE
139
------- |