EPA-600/2-76-253
September 1976
Environmental Protection Technology Series
FRUIT CANNERY WASTE ACTIVATED SLUDGE
AS A CATTLE FEED INGREDIENT
Industrial Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
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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.
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EPA-600/2-76-253
September 1976
FRUIT CANNERY WASTE ACTIVATED SLUDGE AS A CATTLE FEED INGREDIENT
by
Larry A. Esvelt
Bovay Engineers, Inc.
Spokane, Washington 99202
for
Snokist Growers
Yakima, Washington
Grant No. S803307
Project Officers
Harold Thompson
James Santroch
Food and Wood Products Branch - Cincinnati
Industrial Environmental Research Laboratory
Con/all is, Oregon 97330
INOSTRIAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AMD DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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DISCLAIMER
This report has been reviewed by the Industrial Environmental Research
Laboratory, U. S. Environmental Protection Agency, and approved for
publication. Approval does not signify that the contents necessarily
reflect the views and policies of the U. S. Environmental Protection
Agency, nor does mention of trade names or commercial products constitute
endorsement or recommendation for use.
ii
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FOREWORD
When energy and material resources are extracted, processed, converted,
and vised, the related pollutional impacts on our environment and even on our
health often require that new and increasingly more efficient pollution con-
trol methods be used. The Industrial Environmental Research Laboratory-
Cincinnati (lEKL-Ci) assists in developing and demonstrating new and improved
methodologies that will meet these needs both efficiently and economically.
"Fruit Cannery Waste Activated Sludge As A Cattle Feed Ingredient" de-
scribes an attempt to establish a beneficial use of byproducts from an in-
dustrial wastewater treatment system. This use of the byproduct, biologi-
cal solids grown on the soluble carbohydrates in fruit processing wastewater,
could provide a valuable cattle feed supplement while simultaneously provid-
ing a more economical disposal of the substance. For further information,
contact the Food & Wood Products Branch of IERL-CI.
David G. Stephan
Director
Industrial Environmental Research Laboratory
Cincinnati
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ABSTRACT
The feasibility of sludge disposal from a fruit processing waste activated
sludge treatment system by dewatering and using the dewatered biological
sludge solids as cattle feed was evaluated by Snokist Growers at Yakima,
Washington. Dewatering of the biological sludge utilizing pilot scale
and prototype scale basket centrifuges resulted in a consistent product
at 7-1/2 to 9% dry solids. Digestibility and metabolizability of rations
containing 2.3% and 4.5% biological solids appeared equal to a control
ration but a ration containing 9.2% biological solids appeared lower.
Twenty-four uniform yearling steers were divided into four lots of six
each and finished with a control ration and rations containing 2.3%,
4.6% and 8.9% sludge solids on a dry matter basis. They did not show
any adverse effects of the sludge incorporation into their rations. It
appeared that a low quantity of sludge (2.3% dry solids) actually
enhanced the weight gain performance and carcass quality of these
animals. The cost of a dewatering installation will require that the
cannery receive remuneration for use of the waste activated sludge as
cattle feed in order to make a full scale dewatering project feasible.
The calculated value of the biological solids incorporated into the
rations was about $.09 per kg dry solids to $0.15 per kg dry solids.
This report was submitted in fulfillment of Grant No. S-803307 by Snokist
Growers under the partial sponsorship of the U.S. Environmental Protection
Agency. This report covers a period from July 1974 to June 1976, and
work was completed as of June 1975.
IV
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CONTENTS
Page
Foreword i i i
Abstract iv
List of Figures vi
List of Tables vii
Acknowledgments viii
I Introduction 1
II Summary 6
III Conclusions 8
IV Procedures and Equipment 9
V Results 15
VI Feasibility for Full Scale Solids Dewatering and 38
Utilization of Solids as Cattle Feed
VII References 40
VIII Appendix 41
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LIST OF FIGURES
Number Page
1 Snokist Growers Wastewater Treatment System Schematic
Flow Diagram 2
2 Schematic Flow Diagram - Solids Dewatering 10
3 Effect of Centrifuge Hydraulic Loading on Sludge Cake Solids
Content 18
4 Effect of Centrifuge Hydraulic Loading on Initial Centrate Quality 19
5 Pilot Centrifuge Performance Centrate Quality vs Feed Volume . 20
6 Pilot Centrifuge Performance - Centrate Quality vs Solids Fed . 22
7 Digestibility of Rations by Biological Solids Content 24
8 Metabolizability of Rations by Biological Solids Content ... 24
9 Relative Digestibility of Rations by Biological Solids Content. 25
10 Relative Metabolizability of Rations by Biological Solids Content 25
11 Steer Weights Before and After Finishing Feeding Study .... 28
12 Weight Gain by Ration Biological Solids Content 29
13 Dry Matter Consumption in Relation to Body Weight 29
14 Weight Gain in Relation to Dry Matter Consumption 30
15 USDA Grade by Ration Biological Solids Content 31
16 Carcass Yield Grade and Marbling Score by Ration 31
VI
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LIST OF TABLES
Number Page
1 Snokist Grower Wastewater Facilities 3
2 Summary of Activated Sludge Process - 1974 16
3 Centrifuge Biological Solids Dewatering Performance 17
4 Finishing Rations, Dry Matter Basis, Actually Consumed .... 26
5 Proximate Analysis of Concentrates, Hay, Silage and Cannery
Waste Solids Used in Finishing Feed Study 27
6 Dry Matter and Assumed Cost for Basic Components of Rations
Used in Finishing Feed Study 34
7 Value of Biological Solids in Finishing Rations Using Value
of Weight Gain on Control Ration 35
8 Value of Biological Solids in Finishing Rations Using Cost
Saving per Unit Weight Gain in Sludge Rations 36
9 Analysis of Dewatered Biological Solids - Before and After
10 Months Storage 36
10 Feasibility of Full-Scale Dewatering 39
A-l Sludge Dewatering - Pilot Centrifuge 42
A-2 Sludge Dewatering - Prototype Centrifuge 43
A-3 Centrifuge Performance 44
A-4 Flotation Thickener Performance 45
A-5 Results of Metabolism Trials, Dry Matter Digestibility and
Dry Matter Metabolliability 46
A-6 Results of Metabolism Trials, Digestible Energy and
Metabolizable Energy 46
A-7 Individual Weight Gain Records - Finishing Feed Studies .... 47
A-8 165 Day Finishing Feed Studies 48-49
A-9 Content of Biological Solids Dry Solids Basis 50
A-10 Amino Acid Analysis of Biological Solids, DM Basis 51
A-ll Heavy Metals and Arsenic in Biological Solids and Selected
Animal Tissues of Steers Fed 165 Days 52
A-12 Pesticide Residues in Waste Biological Solids 53
A-13 Pesticide Residue in Adipose, Kidneys and Livers of Steers
Fed 165 Days 54
vii
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ACKNOWLEDGMENTS
This study was financed and conducted by Snokist Growers of Yakima,
Washington, with financial assistance from the U. S. Environmental
Protection Agency Research, Development and Demonstration Grant No.
S803307. Messrs. Harold Thompson and James Santroch served as EPA
Project Officers during this investigation. The project was conducted
under the direction of Mr. Jule Graff, Financial Officer, and Mr. Mel
Christenson, Cannery Manager, of Snokist Growers. Wastewater treatment,
sludge dewatering, and laboratory analyses were directed by Mr. Herb H.
Hart and conducted by Ms. Nina Wright, Ms. Jeanne Holdridge and Mr.
Bob Hatzenbeler. The Washington State University Irrigated Agriculture
Research and Extension Center conducted the cattle feeding trials
directed by Dr. Wilton W. Heinemann under contract to Snokist Growers.
Specialized chemical analyses were conducted by the National Canners
Association, Berkeley, California, the Washington State Department of
Social and Health Services laboratories, and by Washington State
University. Dr. Larry A. Esvelt, Bovay Engineers, Spokane, Washington,
was Principal Investigator for this project.
viii
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SECTION I
INTRODUCTION
Snokist Growers, a cooperative located at Yakima, Washington, operates a
cannery that processes pears, apples, peaches, plums, crab apples, cherries
and other products of the growers. Its principal annual pack consists of
canned pears and canned apple products. During a typical season, the
cannery processes up to 300 tons of pears per day for about 2 months,
about 200 tons of peaches per day for 3 days to a week, and about 100
tons of apples per day for 2 to 4 months. In addition, cherries, plums,
and crab apples are processed for limited periods during their harvesting
season. For a number of years, Snokist Growers was subjected to increasing
pressure from regulatory agencies to upgrade the quality of the waste-
waters discharged into the Yakima River. In 1967, the cannery constructed
an aerated lagoon facility, and in 1968 it upgraded that facility to an
activated sludge treatment system with the capability for limited sludge
reaeration. These systems were evaluated under a Federal Water Pollution
Control Administration Research Development and Demonstration Grant. The
results obtained were widely publicized.1»2»3 Due to the success of the
activated sludge system in reducing the cannery effluent to low BOD and
suspended solids levels, the effluent and production data from this plant
were utilized by EPA in establishing the Best Practicable Control Technology
Currently Available guidelines.
The present treatment system at Snokist Growers consists of facilities as
summarized in Table 1 and is shown schematically on Figure 1.
This system has been effective in helping Snokist Growers to reduce the
quantity of pollutants in their effluent adequately to meet State and EPA
permits which were based on "best practicable technology." The principal
costs of operation of the system involve nutrient (nitrogen and phosphorus)
addition (the waste is low in these nutrients), the power for aeration and
sludge recirculation, and sludge disposal.
Biological sludge production by the wastewater treatment system is about
50% by weight of the chemical oxygen demand (COD) in the process waste-
water.1 Endogenous respiration of the biological organisms consumes a
portion of the production and a small amount is lost in the effluent.
Excess biological solids approximates 300 kkg per year.
Excess biological solids from the clarifier underflow has characteristically
had a concentration of 0.5% to 1.0% solids. The sludge thickener has been
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SCREENED WASTE
FROM CANNERY _ NUTR!ENT(N, P)
ADDITION
METERING
TO RIVER
r
SLUDGE
REAERATION
BASIN
DISSOLVED AIR
FLOTATION SLUDGE
THICKENER
AERATION
BASIN
WASTE FLOW
SLUDGE FLOW
Figure 1. Snokist Growers wastewater treatment system schematic
flow diagram.
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Table 1. SNOKIST GROWERS WASTEWATER FACILITIES
Facility
Description
1. Screening
2. Aeration Basin
3. Clarification
4. Sludge Recirculation
5. Sludge Reaeration
6. Sludge Thickening
8 mesh/cm (20 mesh/in) vibrating screens
22,700 cubic meter (6 million gallon) earthen
dike, PVC lined basin with 5 surface aerators
having a total of 292 kw (390 horsepower)
27.5 meter (90 ft.) Diameter, hydraulic
sludge removal, 2.4 m (8 ft.) side water
depth, center feed.
Two variable speed pumps each with 6,600
liter per minute (1750 gallon per minute)
capacity
5,700 cu. meter (1.5 million gallon) basin
with 45 kw (60 horsepower) surface aeration
9.2 meter (30 ft.) Diameter pressurized
recycle flotation sludge thickener
capable of dewatering this sludge to approximately 2.5%. This slurry
is currently hauled by tank truck for disposal on agricultural land. Annual
costs for hauling have been increasing each year since the installation of
the treatment system because of nominal increases in production at the
cannery and because of increased rates by the trucking establishments.
A cost analysis for further dewatering of the solids was conducted at the
cannery, and after finding that the solids could be dewatered to only
approximately 7% to 8% on a dry solids basis utilizing centrifugal or
filter dewatering apparatus, it was concluded that the installation of
such dewatering equipment would not be economically feasible unless the
solids produced were of sufficient economic value to offset some of the
costs for installation of equipment or operation. Use of the solids in
a cattle feeding ration was proposed as a higher value usage. The study
reported in this document was conducted to determine the value of the
waste biological solids when utilized as a portion of a cattle feeding
ration.
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SCOPE AND PURPOSE
The principal purpose of this investigation has been to determine if there
is a feasible alternative to the present methods for disposal of excess
wastewater biological solids from Snokist Growers fruit processing plant.
The means investigated has been that of further dewatering of the biological
solids and its utilization as a cattle feeding supplement in a finishing
ration for beef cattle intended for slaughter and human consumption.
Further dewatering of the solids would decrease the total quantity of wet
solids to be transported, and its utilization as a cattle feed would make
efficient use of the nutrients contained in the solids that have been
derived principally from nitrogen and phosphorus addition to the raw waste-
water to achieve suitable biological treatment. Specific objectives for
the study were as follows:
1. To demonstrate that biological solids from a fruit processing waste-
water treatment plant can be dewatered by centrifugation sufficiently
for use as a portion of cattle feeding ration.
2. To determine the feed value of the biological solids in a total
confinement, controlled feeding study.
3. To demonstrate the effect of incorporation of the biological solids in
a cattle finishing ration at various levels.
Objective 1 was accomplished utilizing both pilot scale (36 cm diameter)
and prototype scale (76 cm diameter) basket centrifuges. Objective 2 was
accomplished in a total confinement feeding of eight steers, and Objective
3 was accomplished by controlled feeding on an individual basis of 24
steers to a finished condition. Sludge dewatering was accomplished at the
Snokist Growers cannery wastewater treatment facility. The dewatered
biological solids were transported to the Washington State University
Irrigated Agriculture Research and Extension Center at Prosser, Washington,
where all cattle feeding studies were conducted.
WASTE SLUDGE USE AS ANIMAL FEED
Fruit and vegetable processing waste solids including wastewater screenings
are commonly utilized as feed to livestock. Dewatered sludge from primary
potato waste treatment facilities has been widely used for feeding cattle.4
Waste activated sludge (biological solids) from citrus processing has
recently been reported used as a poultry feed ingredient following de-
watering by centrifuge and drying on a rotary kiln.5 The participant in
this project reportedly also fed the dried sludge to cattle but did not
report details from the cattle feeding experiment.
Pilot scale centrifuge dewatering of waste biological sludge from a potato-
waste processing, activated sludge treatment system was reported to produce
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80% recovery and 5.5% centrifuge cake solids.6 Although an objective of
the pilot testing was to produce an animal feed, no feeding results were
reported and full scale implementation of the centrifugation has not
occurred.
In the mid 1950's, researchers at the University of Illinois tested dried
municipal activated sludge as a protein and nitrogen source for sheep,
which are ruminants like cattle. The sheep did satisfactorily on a ration
with 6.5% sludge by weight (% moisture unspecified). The sludge provided
only 11.5% of the crude protein and 18% of the total protein. The total
protein in the sludge was significantly less digestible than that in soy-
bean oil meal.7 In general, the sludge was an acceptable source of nitrogen
for the sheep.
Dr. Richard Vetter of Iowa State University reported in 1972 on the feeding
of processed cattle manure back to cattle. Manure, including significant
amounts of sand and dirt, was treated in an oxidation ditch; the sludge
at 6% solids concentration was pumped from the oxidation ditch directly
into a feed wagon and mixed with a basal feed ration. The sludge provided
from 2% to 4% of the dry matter in the feed and 30% to 60% of the total
feed weight. The cattle gained weight normally, were healthy, and the
meat flavor was unaffected.7
Secondary sludge is not being used for feed, possibly because almost all
of the feeding studies have used sludge grown on wastes containing fecal
matter. The U.S. FDA reportedly has refused to approve animals fed such
sludge for interstate commerce.
Secondary sludge grown on food processing wastes may succeeed as a feed
material. Fecal wastes would not be present and the resulting sludge
would be free of pathogenic bacteria.
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SECTION II
SUMMARY
During the 1974 fruit processing season, Snokist Growers conducted a study
of dewatering waste biological sludge from their activated sludge waste-
water treatment system and the utilization of the dewatered sludge as a
cattle feeding supplement. The waste biological solids were dewatered
utilizing pilot scale (36-cm diameter) and prototype scale (76-cm diameter)
basket centrifuges. The centrifuges were successful in dewatering the
biological solids to a range of 7% to 9% dry solids. The dewaterability
of the biological solids appeared to diminish as the organic loading on
the activated sludge treatment system decreased during the late stages of
the season. Use of the sludge following flotation thickening for the
centrifuge feed apparently enhanced dewatering performance. Higher hydraulic
loading rate on the centrifuge dewatering system resulted in increased
suspended solids in the centrate.
Total containment feeding trials were conducted utilizing eight uniform
steers during a period which total feed intake and total excretion of urine
and feces were measured and analyzed. The steers were fed a control ration
and rations containing 2.3%, 4.5% and 9.2% biological solids in the ration.
Digestibility and metabolizability of dry matter and digestible energy and
metabolizable energy were not significantly different among the several
rations containing various levels of biological solids. However, the dry
matter digestibility and metabolizability of rations containing 9.2%
biological solids were lower at the 95% level of significance when
performance of the individual steers on a ration at that level was compared
with performance on the control ration.
A finishing feed trial utilizing 24 steers divided into four groups of six
each was conducted over a period of 165 days. The four groups were fed a
control ration and rations containing 2.3%, 4.6% and 8.9% biological solids
on a dry solids basis. The group fed 2.3% biological solids in their
ration experienced a greater rate of weight gain than the control at the
75% level of significance (but not the 90% level). Feed consumption was
greater for the groups receiving 2.3% and 4.6% biological solids at the
75% significance level (but not at the 90% level). Feed conversion
efficiency was not significantly different from control for any of the
groups.
The average value of biological solids contained in the three rations was
about $92/metric ton of dry solids (about $84/ton) or about $7.30 per kkg
wet sludge at 8% solids by one method of computation where the estimated
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value of weight gain for each of the sludge fed groups of steers was based
on the cost of feed per weight gain for the control group. An alternate
method of computation using the total value of feed per weight gain for
each group and attributing decreased costs for sludge fed groups to the
sludge,resulted in a value of about $148 per kkg.
The .biological solids contained a high crude protein content and would
provide a good source of crude protein as well as calcium and phosphorus
for inclusion into a feed ration for finishing cattle. Heavy metals,
pesticides and microtoxins were not excessive in the biological solids
according to tests on the sludge and on carcasses of the finished animals.
The cattle finished during these studies were slaughtered and graded at the
termination of the project. The cattle fed at the 2.3% biological solids
level had significantly higher USDA grading scores than the control group.
Carcass quality on an overall basis was not diminished at any of the
biological solids feed levels. The slaughtered cattle were marketed in
normal marketing channels following approval for such marketing by the FDA
and USDA. However, it would be necessary to obtain U.S. Food and Drug
Administration approval of the biological solids as a feed supplement in
order to utilize it in this manner on a permanent basis. This approval is
given on an individual source basis and, therefore, approval of utilization
of waste biological solids from one food processing wastewater treatment
facility would not necessarily mean that such approval would be automati-
cally forthcoming for other facilities.
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SECTION III
CONCLUSIONS
Specific conclusions derived from the results of this study are as
follows:
1. Biological sludge solids from a fruit processing waste treatment
system are consistently dewaterable to approximately Q% on a dry
solids "basis with basket centrifugation.
2. Solids dewaterability was decreased with lower loadings on the
biological treatment system (longer sludge age). Dewaterability was
enhanced by sludge thickening ahead of centrifugation. Centrate
quality deteriorated at higher loading rates on the centrifuge.
3. Inclusion of the biological solids in a cattle feeding ration
does not impair the metabolizability or digestibility of the
ration at approximately 5$ or less biological solids on a dry
matter basis.
U. The biological solids incorporated in cattle finishing rations
at approximately 9$ or less resulted in weight gain and feed
consumption equal to that for control fed cattle and may have
improved weight gain performance at approximately 2.3% biological
solids in the ration.
5. Carcass quality of the cattle fed on rations containing biological
solids up to a level of 9% on dry matter basis were at least
equivalent to those fed on control ration, and possibly improved at
from 2% to 5% biological solids.
6. There were no apparent harmful effects on cattle fed the biological
solids. Heavy metals and pesticide residue were not found in
significant quantities in the biological solids or the carcasses.
Harmful microtoxins were not found in the biological solids.
?. It will be necessary to take financial advantage of the feed value
of the waste biological solids in order for dewatering of the solids
by centrifugation to be economically feasible compared to the present
methods of sludge disposal for the cannery waste treatment system
utilized in this study.
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SECTION IV
PROCEDURES AND EQUIPMENT
Procedures and equipment utilized in this study were developed appropriate
to the three objectives listed in Section I. Facilities at the Snokist
Growers cannery, consisting of their wastewater treatment system and
rental or on-loan dewatering equipment, were utilized to dewater the excess
biological solids from their activated sludge processing waste treatment
system. Figure 1 showed a schematic flow diagram of the Snokist Growers
wastewater treatment facilities. Figure 2 is a schematic diagram for
sludge dewatering operations during these investigations. Facilities at
the Washington State University Irrigated Agriculture Research and Extension
Center at Prosser, Washington, were utilized for both the total containment
metabolism studies and the cattle feeding trials for determining the
solids value in a cattle finishing ration.
BIOLOGICAL SOLIDS DEWATERING STUDIES
Solids dewatering investigations were conducted with solid bowl basket
centrifuges. The first portion of the investigation consisted of utilizing
a 36 cm diameter by 15 cm deep centrifuge (14 in. by 6 in.) to study the
dewaterability of the biological solids and concurrently to recover de-
watered solids for utilization in the metabolism trials under Objective 2.
During the second portion of the dewatering investigation a 76 cm diameter
by 46 cm deep centrifuge (30 in. by 18 in.) was used to confirm the pilot
scale centrifuge results on a prototype scale unit and to concurrently
produce dewatered biological solids for utilization during the cattle
finishing feeding trials under Objective 3.
Pilot-Scale Centrifuge Investigations
The pilot-scale (36 cm diameter by 15 cm deep) basket centrifuge was
operated from about October 16, 1974 through December 13, 1974 on a 5 or
6-day per week basis. On each day of operation one centrifuge run (test
run) was conducted during which the influent to the centrifuge was sampled
before and after the run and the centrate was collected in 19 liter (five
gallon) batches and each batch sampled. The dewatered solids were entirely
removed from the centrifuge following the test run and four samples of the
dewatered cake were collected for analysis, one sample near the centrifuge
periphery for approximation of the maximum solids content and the other
three samples after mixing the entire centrifuge cake discharge to determine
an average. Analyses conducted on the test run samples included suspended
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AIR
CLARIFIER EFFLUENT
PRESSURIZATION
SYSTEM
BIOLOGICAL SOLIDS FROM
CLARIFIER UNDERFLOW
CLARIFIER
SOLIDS
u.
FLOTATION
THICKENER
ALTERNATE CENTRIFUGE?*-
FEED SOURCES 1 ,
THICKENED
SOLIDS
CENTRATE
DEWATERED
FEED SKIM-
MER
SOLIDS
BASKET
CENTRIFUGE
Figure 2. Schematic flow diagram - solids dewatering.
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solids on the centrifuge feed and on the centrate, and total solids on the
centrifuge dewatered solids (cake). Volatile solids analyses were
conducted periodically as were other analyses such as pH, COD, nitrogen
and phosphorus. The centrifuge feed came from either the clarifier under-
flow or from the flotation sludge thickener as shown on Figure 2. During
periods of thickener operation, feed, pressurized water, subnatant and
thickened solids were sampled for analysis.
The wastewater treatment system received wastes from the pear processing
operation up through approximately November 9 and from apple processing
for the remainder of the study period.
Prototype Centrifuge Investigations
Operation of the prototype (76 cm diameter x 46 cm deep) basket centrifuge
extended intermittently from December 17 through April 14. On each day of
operation one centrifuge run was used for data collection at which time
the feed stream was sampled before and after the run and the dewatered cake
was sampled four times, once in an attempt to get the maximum concentration
cake and three times after mixing the entire dewatered solids discharge in
an attempt to get the average cake solids. Centrate was also sampled
although not on a total collection basis and less frequently than during
the pilot scale centrifuge operation. The dissolved air flotation sludge
thickener was operated during a portion of the prototype centrifuge oper-
ation also, and once again it was monitored for performance.
Apple processing was conducted during a portion of the prototype centrifuge
operation, but during the bulk of the operation there was no processing
occurring at the cannery and solids dewatered were derived from those
stored in the aeration basin under aerobic conditions from the previous
processing operations.
METABOLISM TRIAL
Dewatered biological solids from the pilot basket centrifuge were trans-
ported to the Washington State University Irrigated Agriculture Research
and Extension Center at Prosser, Washington (approximately 80 kilometers)
for utilization as a portion of rations fed to eight steers for metabolism
feeding trials.
The eight steers were divided into four sets of two for a "latin square"
feeding trial where total intake monitoring and excretion collection and
monitoring was conducted. Each pair of steers was fed each of four
separate rations on a rotating basis such that during any testing period
each of the four rations was fed to two of the steers, and during the
four testing periods each pair of steers received each of the four rations
during one test period. Each test period was divided into a 10-day adjust-
ment period during which the steers were acclimated to the new ration and
a 7-day total collection period during which feed intake and feces and
urine excretion were monitored.
11
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The four rations consisted of a basic ration (similar to that used during
the finishing trials under Objective 3) for a control and three rations
which included varying amounts of biological solids in the basic ration.
The three biological solids rations contained 2.3%, 4.5% and 9.2% dewatered
biological solids on a dry matter (DM) basis.
Samples of the feeds, feces and urine were analyzed for total dry matter
(DM) and gross energy (GE). These data were used to determine (1) dry
matter digestibility (DMD); (2) dry matter metabol izabil ity (DMM); (3)
digestible energy (DE); and (4) metabolizable energy (ME). These were
determined as shown in the following formulas:
DMD = DM consumed - DM feces
DM consumed
DMM = DM consumed - DM feces - DM urine - DM respiration (estimated)
DM consumed
DE = GE consumed - GE feces
GE consumed
ME = GE consumed - GE feces - GE urine - GE respiration (estimated)
GE consumed
Total feed consumed and feces and urine output was measured each day. Dry
matter testing was conducted using high vacuum freeze drying of each of the
metabolic composite samples collected over the seven day testing period.
Samples stored at 2°C (under toluene for urine and in air tight plastic
containers for feces) were analyzed for gross energy in a bomb calorimeter.
CATTLE FINISHING TRIAL
Twenty-four yearling steers of approximately uniform composition were
randomly allotted to four lots of six each for feeding four separate rations
including a control ration and rations that contained 2.3%, 4.6%, and 8.9%
dewatered biological solids on a dry solids basis. Each steer was individu-
ally fed the amount of ration that he would consume completely each day (as
nearly as practical). Total feed intake and weight gain over a 165-day
finishing period were monitored (the cattle were acclimated to the feed for
approximately 2 weeks before the initiation of testing).
The cattle were weighed on 28-day intervals with each weighing following a
16-hour period during which feed was withheld. The cattle were full fed,
and the small amount of refused feed was weighed and analyzed. Feed testing
for dry matter, crude protein, crude fiber, ether extract, ash, calcium
and phosphorus was conducted on composite samples collected over a month
period on a weekly basis. The biological solids moisture content was
determined daily prior to mixing the rations in order to maintain a
consistent dry biological solids proportion.
12
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Carcass grades and weights were observed following the slaughter. Pesticide
and heavy metals analyses were made of tissue samples from two control and
two biological solids fed animals.
ANALYTICAL PROCEDURES
Analytical procedures generally followed Standard Methods8 and the EPA
Methods for Chemical Analysis of Water and Wastes.9 All testing of waste-
waters and wastewater biological solids were performed at Snokist Growers
Wastewater Laboratory. Duplicate analyses were performed on approximately
10% of all samples analyzed with duplicate results less than 5% apart with
the exception of a few very low strength samples. Additionally, Snokist
Growers Wastewater Laboratory conducted analyses on test samples submitted
by the EPA Region X Laboratory and the EPA Corvallis Environmental Research
Laboratory with satisfactory results. A summary of methodology utilized by
the Snokist Wastewater Laboratory is as follows:
pH-electrometrically determined according to Standard Methods.8
Total solids-gravimetric following drying at 103°C according to
Standard Methods.8
Volatile solids-gravimetric following ashing at 550°C according to
Standard Methods.8
Total suspended solids-glass fiber filter drying at 103°C and
gravimetric residual analysis according to Standard Methods.8
Volatile suspended solids - ashing of the total solids residual at
550°C followed by gravimetric analysis Standard Methods.8
Chemical Oxygen Demand (COD)- KpC^O/ according to EPA Methods.9
Biochemical Oxygen Demand (BOD)-Standard Methods.8
Ammonia Nitrogen (Nh^Nj-Distillation/titration Standard Methods.8
Total Kjeldahl Nitrogen (TKN)-Standard Methods.8
Orthophosphate - stanouschloride method, Standard Methods.8
Total Phorphorus - Alkaline ashing followed by stanouschloride
method.8
Preservation was by refrigeration (4°C) of composite samples for next-day
analysis. Grab samples were analyzed immediately.
Analyses by WSU were conducted as indicated earlier with dry matter analyses
utilizing high vacuum evaporation; gross energy analyses utilizing a bomb
calorimeter; kjeldahl nitrogen was determined according to standard methods;8
13
-------
fat was determined as ether extractable material; calcium was determined by
nitric/perchloric acid digestion followed by atomic absorption; phosphorus
was determined by nitric/perchloric acid digestion and molydivaradophos-
phoric acid colorimetric analysis.10 WSU replicated 10% of its analyses
with satisfactory duplication of results. Storage was by high vacuum
freeze drying and by storage at 2°C under toluene (urine) and in air tight
containers (feces).
Pesticide residuals were determined by the Washington State Department of
Social and Health Services Laboratory in Wenatchee, Washington by a
chromatographic procedure.
Heavy metals analyses were conducted by atomic absorption spectroscopy by
the National Canners Association Laboratory in Berkeley, California, and
U. S. Testing Company in Richland, Washington.
14
-------
SECTION V
RESULTS
Solids dewatering studies were conducted with the pilot plant scale (36 cm
diameter by 15 cm) basket centrifuge during the period from October 16,
1974, through December 13, 1974. During this same period the total
confinement feeding trials were conducted by WSU utilizing solids dewatered
with the pilot scale centrifuge. The prototype scale centrifuge (76 cm
diameter by 46 cm) was utilized for dewatering solids from December 17,
1974, through April 14, 1975. The finishing feeding trials were conducted
at WSU from December 1974 through the end of May 1975 using solids de-
watered on the prototype scale centrifuge.
During the 1974 processing season, pears were processed for 59 days,
peaches for about 4 days and apples for about 23 days separately from the
other fruits. Concurrent apple processing and pear processing was
conducted during the last half of the pear processing season. Processing
continued from late August through approximately the middle of December
1975 and for a short period during February 1975 when apples were processed.
Table 2 shows a summary of the activated sludge process operation during
the 1974 season. Mean and standard deviation of the influent chemical
oxygen demand (COD), the COD loading on mixed liquor volatile suspended
solids (MLVSS), and effluent COD and suspended solids are included by
product processed. Mean influent and effluent BOD values are shown even
though data was not extensive. Table 2 also contains the mean and standard
deviation of waste flow by product processed. The concurrent pear and
apple processing is included under pear processing.
SOLIDS DEWATERING INVESTIGATIONS
Dewatering Performance
During solids dewatering investigations with the pilot scale centrifuge
hydraulic feed rate to the centrifuge, solids feed rate to the centrifuge
and centrifuge rpm were studied as variables in the operation. Centrifuge
rpm was adjusted to attain centrifugal forces of 1240, 1340 and 880 g's
(2500, 2600 and 2100 rpm). The centrifuge was operated at 1240 g's during
the early part of the processing season when pears were creating a heavier
load on the activated sludge system and later at 1340 and 880 g's during
apple processing when lower loading rates (F/M) were exerted on the bio-
logical system. Table 3 contains the solids dewatering performance during
these periods.
15
-------
Table 2. SUMMARY OF ACTIVATED SLUDGE PROCESS - 1974
Mean/Std. Deviation (No. of observations)
Pear
Processing
Item (49 days)
Peach
Processing
(4 days)
Apple
Processing
(23 days)
Influent COD, mg/1
COD Loading on MLVSS (F/M),
2740/440
1670/220
550/100
day"
Effluent COD, mg/1
Influent BOD, mg/1
Effluent BOD, mg/1
Effluent Susp. Sol., mg/1
Flow, 103 m3/day
0.14/0.04
52/43
1850(6)
7(8)
19/17
5.9/0.6
0.07/0.01
24/6
7/1
6.9/1.3
0.024/0.009
52/39
400(1)
6(7)
20/12
3.8/1.4
It appears that the centrifugal force between 880 and 1340 rpm did not
have an important effect on the final solids concentration. Final centri-
fuge cake concentration did not seem to be affected by solids or hydraulic
feed rates as illustrated on Figure 3 (see Appendix Tables A-l and A-2).
Operation of the prototype scale centrifuge (76 cm diameter) was continuous
at 1300 g's throughout its operation. Solids dewatered performance is shown
in Table 3 for various operating periods. During January and later de-
watering periods loading to the activated sludge system had been low or
stopped for a considerable period of time. Apparently centrifuge perform-
ance deteriorated as the sludge age increased. During April the centrifuge
was fed dissolved air flotation thickened sludge, and the average cake
concentration increased notably making it appear that there was benefit in
utilizing thickened sludge for the centrifuge feed. This was somewhat
confirmed by the pilot results when three days operation on thickened feed
averaged 76.9 gDS/kg sludge cake on 11/22-26 compared to operation on
clarifier underflow averaging 74.2 gDS/kg sludge cake during the period
11/4 through 12/5 (see Appendix Table A-l).
Centrate Quality
The effect of hydraulic loading on the centrifuge in initial centrate over-
flow suspended solids concentrations is shown on Figure 4. The three sets
of data included in Figure 4 (see Appendix Table A-l) were obtained
utilizing different hydraulic detention times (tf) and centrifuge rpm's. It
appears that the difference between the lines placed through the three sets
16
-------
Table 3. CENTRIFUGE BIOLOGICAL SOLIDS DEWATERING PERFORMANCE
Centrifugal Force Sludge Cake Concn. gDS/kg**
Dates g's Ave. Std. Dev.
Pilot Centrifuge (36-cm dia) (See Appendix Table A-1)
10/6-11/13/74
11/8-12/4/74
12/6-12/13/74
1240
1340
880
82.1
76.4
74.8
4.9
7.4
7.9
Prototype Centrifuge (7.6-cm dia, 1300 g's) (See Appendix Table A-2)
12/17-12/20/74 84.0 8.7
1/20-2/3/75 80.1 5.6
3/19-3/31/75 70.0 8.9
4/1-4/14/75* 85.9 7.4
*Flotation thickened sludge feed
**Grams dry sol ids/kilogram wet sludge cake
of data points is time related rather than related to the centrifuge rpm
or centrifugal force. This may be related to sludge age, as was the cake
concentration discussed above, and again indicates deteriorating centrifuge
performance at higher sludge age. It is apparent from Figure 4 though that
there is a relation between hydraulic loading and centrate quality in that
during each of the three data collection periods centrate quality deterio-
rated as hydraulic loading increased.
During centrifugation on a batch type basis such as occurs with basket
centrifuges, the quality of the centrate deteriorates as the centrifuge
bowl fills with cake. Figure 5 contains performance curves for the pilot
centrifuge, giving centrate quality versus the feed volume in number of
hydraulic detention times. The various curves on Figure 5 were obtained
utilizing a wide variation of feed concentration, solids retention times
and hydraulic retention times. The hydraulic retention time is defined as
the volume of the centrifuge divided by the sludge flow rate. Solids
retention time is defined as the volume of the centrifuge times the
ultimate cake concentration during the centrifuge run, divided by the
solids feed rate to the centrifuge.
17
-------
100
80
60-
UJ
^^
^J
o
CT
en
a
o>
g
_j
o
en
ui
o
UJ 40
o
o
20
o PILOT CENTRIFUGE 2500 RPM
Q PILOT CENTRIFUGE 2600 RPM
O PILOT CENTRIFUGE 2100 RPM
A PROTOTYPE CENTRIFUGE
• A THICKENED SLUDGE FEED
•
*
g
O
A
0.2
0.4 0.6
l/t, mirf1
10
8
0.8
1.0
Figure 3. Effect of centrifuge hydraulic loading on sludge cake solids
content.
18
-------
.14-
.12*
.08
o
u_
OC
Ul
.04
.02
O 2500 RPM- 10/16-11/13
D 2600 RPM - 11/8 -12/5
O 2100 RPM-12/6- 12/13
8
0.2
0.4
0.6
0.8
1.0
l/t, mln'1
Figure 4. Effect of centrifuge hydraulic loading on initial centrate
quality.
19
-------
1.0
0.8
tf)
tf)
Q
UJ
0.6
ro
o
tf)
tf)
o
i! 0.4
UJ
O
0.2
SOLIDS RETENTION
TIME, SRT, min
12.3
81.3
15.0
35.8
24.2
46.6
HYDRAULIC
TIME.t.mln
0.94
6.4
1.3
2.1
7.5
2.7
RETENTION
CENTRIFUGE VOLUME (I) x
CAKE CONCENTRATION (g/l)
SOLIDS FEED RATE (g/min)
CENTRIFUGE VOLUME (I)
SLUDGE FLOW RATE (l/min)
0 4 8 12 16 20
VOLUME FED/CENTRIFUGE VOLUME
Figure 5. Pilot centrifuge performance centrate quality vs feed volume.
24
-------
Figure 5 shows the variations in the number of hydraulic retention times
required for the centrifuge to fill with solids, at which time higher
concentrations of suspended solids in the overflow of centrate occurs.
Figure 6 shows the same data runs plotted on the basis of solids retention
times. As expected the overflow or centrate quality begins to deteriorate
relatively near one solids retention time regardless of hydraulic
retention time and feed suspended solids concentration, For virtually
all of the runs the centrate suspended solids stayed at or below approxi-
mately .10% of the feed solids up through 0.7 to 0.8 solids retention times
and subsequently began to increase in an S-curve configuration. Data used
to develop Figures 5 and 6 is contained in Appendix Table A-3.
Dissolved Air Flotation Thickener Performance
The existing dissolved air flotation thickener at Snokist Growers was used
to thicken biological sludge for wasting during the 1974 processing season
and the thickened sludge was used for centrifuge feed on several occasions.
Performance of this unit was monitored during two periods, one in late
November, early December, 1974 and the other during April 1975. The fall
1974 monitoring period followed shortly the pear processing season and was
during apple processing so the biological solids were active and being fed
regularly. By April 1975 the solids had not been fed for some time
although they had been maintained in an aerobic condition.
Results of the monitoring are shown in Appendix Table A-4.
The mean thickened solids concentrations during fall 1974 and spring 1975
monitoring was 25.7 and 21.3 grams dry sol.ids (D.S.) respectively. Standard
deviations were 2.8 and 2.3 g/1 respectively. The means were significantly
different at greater than the 99% level using Student's t distribution11
and indicate better thickening during the period of greater biological
activity (shorter sludge age). This observation supports the observations
of poorer centrifuge performance at lower biological activity (longer
sludge age).
21
-------
10-
FEED SOLIDS RETENTION HYDRAULIC RETENTION
SS.o^l TIME, SRT.min TIME,I,mm
08-
60
6.5
79
5.3
22.7
3.7
12 3
813
ISO
358
24.2
466
0.94
6.4
I 3
2.1
75
2.7
.
.
,RT CENTRIFUGE VOLUME (I) K CAKE CONCENTRATION;
SOLIDS FEED RATE (g/min)
06-
?,mln
CENTRIFUGE VOLUME (I)
SLUDGE FLOW RATE (l/min)
-
•
04-
02-
Or
02 0.4 06 0.8 1.0 1.2
SOLIDS FED/CENTRIFUGE VOLUME X CAKE CONCENTRATION
Figure 6. Pilot centrifuge performance - centrate quality vs solids fed.
1.4
-------
TOTAL COLLECTION METABOLISM TRIALS
Digestibility and metabolizability data for the four rations were obtained
from total collection trials. The rations, feces and urine were quantitated
over a seven day period and analyzed for total dry matter (DM) and gross
energy (GE). These data were used to determine (1) dry matter digestibility
(DMD); (2) dry matter metabolizability (DMM); (3) digestible energy (DE);
and metabolizable energy (ME). These were determined as follows:
DMD = DM consumed - DM feces
DM consumed
DMM = DM consumed - DM feces - DM urine - DM respiration (estimated)
DM consumed
DE = GE consumed - GE feces
GE consumed
ME = GE consumed - GE feces - GE urine - GE respiration (estimated)
GE consumed
Dry matter and gross energy contained in the respiration of the animals was
estimated utilizing constants for the type and weight of animals used which
had been developed in other studies.
Figure 7 shows the digestibility of the rations according to their content
of waste biological solids. Figure 8 shows the metabolizability of the
rations according to the biological solids content. Neither the digesti-
bility or the metabolizability of the dry matter and energy is significantly
affected by the inclusion of the biological solids in the rations.
Figure 9 and Figure 10 show the mean relative digestibility and metaboliz-
ability and standard deviations, for each of the rations on a dry matter
basis. The performance of each individual animal on the control ration was
taken at 1.0 and the relative performance was used for rations including
the biological sludge. From Figures 9 and 10 there appears to be a decrease
in digestibility and metabolizability at the highest concentration of bio-
logical solids used. The relative performance is significantly different11
(95^ level, Student's t) from the control only for the ration containing
the highest sludge level however. Relative DE and ME values showed much
higher standard deviations, and significant differences from the control
could not be identified.
Appendix Tables A-5 and A-6 contain individual DMD, DMM, DE and ME data for
the steers and rations used in this study.
23
-------
Q
5
Q
^DMD
u*
UJ
w so- LEGEND:
MEAN _I f 2 STANDARD
MtAN J ^ DEVIATIONS
i CE
> UJ
H 2
- UJ
=! 25-
m
- cr
H UJ
00
25-
1
5 0 2.3 4.5 9.2
£ PERCENT BIOLOGICAL SOLIDS IN RATION
Z
Figure 8. Metabolizability of rations by biological solids content.
24
-------
Q
Z
Q
I.I-
-
H
_J
CD
O
00
UJ
2
£t
O
PERCENT BIOLOGICAL SOLIDS IN RATION
Figure 10. Relative metabolizability of rations by biological
solids content.
25
-------
CATTLE FINISHING TRIALS
Four lots of six uniform yearling beef type steers were individually full
fed 165 days to finish on a ration consisting of alfalfa cubes, corn silage,
barley, beet pulp, TM salt, Vitamin A and, for three of the groups, de-
watered biological solids from the cannery wastewater treatment system.
Biological solids were incorporated into the study rations at 2.3%, 4.6%
and 8.9% levels as shown in Table 4. Table 5 gives the proximate analysis
of the various ration ingredients and the calculated values for the over-
all rations. The finishing trials were conducted over a period of 165
days.
Table 4. FINISHING RATIONS, DRY MATTER BASIS, ACTUALLY CONSUMED
Ingredient
Alfalfa Cubes
Corn Silage
Concentrate!/
Sludge Biological Solids
Control
12.4
8.5
79.1
Percent in Ration
Low Sludge Medium Sludge
12.3
8.5
76.9
2.3
12.4
8.3
74.7
4.6
Hi\gh Sludge
12.4
8.2
70.5
8.9
I/ Concentrate consisted of 80.4% Barley, 18.9% Beet Pump, 0.7% Salt and
Vitamin A to supply about 20,000 IU per day.
The mean and standard deviation of the weights for each of the four groups
of steers before the finishing feeding trial and following the finishing are
shown on Figure 11 (see Appendix Table A-7). There was not a significant
difference between the groups of steers selected for feeding on the various
rations, although the group fed the ration containing 2.3% biological solids
appears to be slightly heavier following finishing.
Figure 12 shows the average weight gain rate and the standard deviation in
weight gain for the various groups of steers. The group of steers fed the
ration containing 2.3% biological solids experienced a significantly greater
mean rate of weight gain than the control group at the 75% level but not
at the 90% level using Student's t distribution.11 The 4.6% and 8.9% bio-
logical solids groups were approximately equal to the control in weight
gain. Weight gain records for each of the steers used in this study are
shown in Appendix Table A-7.
Figure 13 shows the mean dry matter consumption rate, and the standard
deviation, in relation to body weight for the various groups. Each of the
26
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Table 5. PROXIMATE ANALYSIS OF CONCENTRATES. HAY, SILAGE AND
CANNERY WASTE SOLIDS USED l\ FINISHING FEED STUDY
Composition on Dry
Ration Identity
or Ingredient
Alfalfa cubes
Corn silage
Concentrates (80.4%
Control
Low level waste
Hed. level waste
High level waste
Cannery waste
biological solids
Overall Ration
Control
2.35 Biol. Sol Ids
4.65 Biol. Solids
8.95 Biol. Solids
Dry
Matter
90.1
31.6
Barley,
90.3
90.5
90.5
90.6
7.42
78.0
64.0
54.2
42.1
Crude
Protein
18.4
7.2
19. 91 Beet
12.8
13.1
13.4
14.4
39.1
13.0
13.8
14.7
16.5
Crude
Fiber
26.30
20.30
Pulp,
8.25
8.20
8.30
8.10
3.20
11.5
11.4
11.3
10.9
Ether
Extract
1.95
3.55
0.7*a Salt)
1.70
1.60
1.50
1.55
.80
1.9
1.8
1.7
1.7
Basis,
Ash
8.58
8.32
4.08
4.26
3.90
4.36
11.64
5.0
5.3
5.2
5.9
•V
o
Ca
1.35
.30
.17
.20
.20
.25
1.08
.33
.37
.39
.46
P
.32
.27
.30
.32
.31
.29
1.28
.30
.34
.35
.38
27
-------
700 —
600-r
AFTER FINISHING
500 —
BEFORE FINISHING
300 —
o
UJ
200 —
100 —
i
2.3
4.6
I
6.9
Figure 11.
PERCENT BIOLOGICAL SOLIDS IN RATION
Steer weights before and after finishing feeding
study.
28
-------
1.5-
1.0-
0.5-
2.3
4.6
8.9
PERCENT BIOLOGICAL SOLIDS IN RATION
Figure 12. Weight gain by ration biological solids content.
$25-
20-
I
15-
o
H
Q.
l.o-
O
U
O
UJ
UJ
5-
i
2.3
i
4.6
8.9
PERCENT BIOLOGICAL SOLIDS IN RATION
Figure 13. Dry matter consumption in relation to body weight.
29
-------
three groups fed rations containing the biological solids had a greater
average feed consumption than the group on the control ration, and the
groups fed 2.3% and 4.6% biological solids were significantly greater at
the 75% level, but not at the 90% level, using the Student's t distribution.
Feed consumption is shown for the individual steers in Appendix Table A-8.
The mean and standard deviation for the groups of steers of the amount of
dry matter consumed is shown on Figure 14. The steers on the control
ration and the ration containing 2.3% biological solids were approximately
equal in feed conversion efficiency. The overall conversion efficiency on
the rations with 4.6% and 8.9% biological solids appear to be slightly
less although they are not significantly less at the Student's t 75%
level.
CARCASS QUALITY
Following slaughter of the animals used in the finishing feed trials, the
USDA grade, yield grade and marbling scores were recorded for each of the
carcasses. The USDA grade and marbling scores were given numerical equiva-
lent values to allow the determination of means and standard deviations for
the various groups of cattle. Figures 15 and 16 show the USDA grade,
marbling score and yield grade mean and standard deviations for the groups.
The USDA grade and marbling score are significantly higher at the 95% level
•* I60-,
Z
d
80-
60-
2.3
I
4.6
8.9
PERCENT BIOLOGICAL SOLIDS IN RATION
Figure 14. Weight gain in relation to dry matter consumption.
30
-------
PRIME -
UJ
O
<
oc
O
CHOICE-
GOOD - r
2.3 4.6
PERCENT BIOLOGICAL SOLIDS IN RATION
8.9
Figure 15. USDA grade by ration biological solids content.
ABUNDANT-,.
MODERATE -
-4
T -3
-I
SLIGHT-
0 2.3 4.6
PERCENT BIOLOGICAL SOLIDS IN RATION
Figure 16. Carcass yield grade and marbling score by ration.
8.9
31
-------
using Student's t distribution for the group of steers which received 2.3%
biological solids in their ration. The yield grade for the groups
receiving 2.3% and 4.6% biological solids in their rations are signifi-
cantly higher than the control group at the 75% level using the Student's
t distribution but not at the 90% level. It is safe to definitely conclude
that carcass quality was not adversely affected by the incorporation of
biological solids in the rations at any of the levels used. There may have
been some enhancement at low sludge feeding levels. Carcass grading
results for all steers are shown in Appendix Table A-8.
The carcasses from all steers used in the finishing feed trials were
approved for public sale by USDA and FDA and were sold through normal
marketing channels of a commercial slaughterhouse. However, approval of
the biological solids as a permanent feed supplement has not been received
and will be necessary prior to implementation of a full scale feeding
program.
FACTORS AFFECTING THE SUITABILITY OF BIOLOGICAL SOLIDS AS A PORTION OF A
CATTLE FINISHING FEED RATION
Protein
Table 5 contains proximate analysis of the various components of the
rations. The waste biological solids contained a high content of crude
protein and higher concentrations of calcium and phosphorus than the
other components of the feed. Appendix Table A-9 contains additional
analysis results of the dry solids which confirm their high N and P
contents. The solids apparently would provide a good source of protein
to be incorporated into a feeding ration. An analysis of the biological
solids for amino acid content was conducted and is shown on Appendix
Table A-10. Based on amino acid content the solids contained only
between 20 and 27% percent amino acid protein on a dry solids basis as
opposed to 39 percent calculated from kjeldahl nitrogen. This difference
may not be significant due to the inherent difficulty of running amino
acids analyses and does not change the overall conclusions that the waste
biological solids are a good source of nitrogen.
Heavy Metals
Heavy metals analyses were conducted on the waste biological solids and on
tissue samples from four of the steers involved in the finshing feed
trials. Two of the steers were from the group which received the control
ration and two of the steers from the group which received 8.9% biological
solids in their ration. The results of the analyses are shown in Appendix
Table A-ll. There were no consistent differences in heavy metals retention
between steers on the two rations.
32
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Pesticides
Pesticide analyses were conducted on the waste biological solids and on the
same tissue samples as for heavy metals analysis. Appendix Tables A-12 and
A-13 show the results of these analyses. The pesticides for which residues
are shown are the only pesticides for which residues could be determined in
a screening analysis for chlorinated hydrocarbon, carbamate and phosphate
pesticides. The pesticide residues contained in the biological solids
apparently did not result in unacceptable levels in any of the rations fed
as there were no consistent differences in the pesticide residue levels in
the tissue samples from the cattle that received control biological solids
rations.
Analyses for patulin and penicillic acid in the waste biological solids were
performed by the WSU College of Agriculture. The analyses were negative
for residues of both of these microtoxins.
FEED ECONOMIC VALUE OF BIOLOGICAL SOLIDS
Table 6 contains a calculation of the total cost of the basic ration
components in each of the rations fed during the finishing feed studies on
a total metric ton dry solids basis. The basic cost of the ration, given
the assumed costs for the individual feed components shown, are for all dry
matter included in the ration excepting the biological solids. As expected,
the rations with higher biological solids have a lower base ration component
cost due to the replacement of barley and beet pulp by the biological solids.
The value of the biological solids utilized in the finishing feed rations
is calculated in Table 7. For this calculation the average cost of the
control ration per kilogram of weight gained on the control group of steers
was used as a basic value for average weight gain of the steers on all
rations. The calculations utilize mean weight values for the other three
groups of steers. They indicate a wide variation in the value of the bio-
logical solids incorporated.
A different method for calculating economic value of the sludge is pre-
sented in Table 8. This computation uses the mean value for feed components
per unit weight gain for all of the steer groups and assigns the cost
saving for the sludge fed groups to sludge value. This method results in
a higher value for the biological solids than the method in Table 7.
The values placed on the biological solids, while differing in magnitude,
place a strong argument for the economics of placing these solids in a
cattle feeding ration. The values obtained can be used to place the
costs for product dewatering in a proper perspective and give potential
cattle feeders an indication of the value of such a feed component.
33
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Table 6. DRY MATTER AND ASSUMED COST FOR BASIC COMPONENTS OF RATIONS
USED IN FINISHING FEED STUDY
Feed
Component
Alfalfa Cubes
Corn Silage
Barley
w Beet Pulp
TM Salt
Biological Solids
Assumed Cost of
Basic Ration
Components
Control
Assumed
Cost % $/kkg
$/kg DM Ration Ration
.086 12.4 10.70
.052 8.5 4.40
.159 63.6 101.30
.110 15.0 16.50
.055 .5 .30
133.20
Ration
2.3% Biol. Sol. 4.6% Biol. Sol.
DM DM
Ration
12.3
8.5
61.9
14.5
.5
2.3
$/kkg
Ration
10.60
4.40
98.40
16.00
.30
129.70
Ration
12.4
8.3
60.1
14.1
.5
4.6
%/kkg
Ration
10.60
4.30
95.60
15.50
.30
126.30
8.9% Biol. Sol.
DM
Ration
12.4
8.2
56.6
13.3
.5
8.9
$/kkg
Ration
10.60
4.30
90.00
14.60
.30
119.80
-------
Table 7. VALUE OF BIOLOGICAL SOLIDS IN FINISHING RATIONS
USING VALUE OF WEIGHT GAIN ON CONTROL RATION
2.3% 4.6% 8.9%
Biol. Sol. Biol. Sol. Biol. Sol
Item
Wt. Gain, kg/kkg DM
Cost of Basic Ration,
Control
136
133.20
DM
137
129.70
DM
129
126.30
DM
130
119.80
$/kkg total ration ($.979/kg gain)
Value of Ration Based on 134.10 126.30 127.30
Control ($.979/kg gain), $
Value of Biological Solids 4.40 0 7.50
in Ration, $
Value of Biological Solids 191.30 0 84.30
$/kkg DM
Average Value of Biological Solids = $92/kkg DM, $7.30/kkg Sludge at
8% Solids.
EFFECT OF STORAGE ON DEWATERED SOLIDS
It was apparent during the study of cattle feeding of the biological solids
it would be necessary to store these solids. During the study, storage was
in 55 gallon plastic lined drums in a cool atmosphere. The drums were
stored indoors in a facility at the USU Irrigated Agriculture Research
Extension Center prior to use, but in effect were refrigerated during the
entire period of storage, which was two months maximum during any portion
of the study.
In order to determine the effect of long term storage on the dewatered bio-
logical solids, one 55 gallon plastic lined drum of the solids was set aside
from sludge dewatered on February 3, 1975. This drum was stored in the
cannery warehouse (approx. 20°C) up through approximately mid-August at which
time necessity to utilize the space required that it be moved from the ware-
house. Subsequently it was stored outside of the warehouse area at the
cannery, which probably allowed it to get quite warm due to the high ambient
daytime temperatures during September of 1975. Sludge stored in the drum
was analyzed on the day it was placed and sampled from the top, mid-depth
and near the bottom of the barrel on December 1, 1975. The results of
these analyses are shown on Table 9.
35
-------
Table 8. VALUE OF BIOLOGICAL SOLIDS IN FINISHING RATIONS
USING COST SAVING PER UNIT WEIGHT GAIN IN SLUDGE RATIONS1
Group
Control
2.3%
4.6%
8.9%
Group
Control
2.3%
4.6%
8.9%
Average
Total
7.53
7.34
7.82
7.73
Kg DM/ kg Gain
Concentrate
Alfalfa Corn (Barley, Beet
Cubes Silage Pulp, Salt)
.934
.903
.970
.959
.640
.624
.649
.634
5.936
5.. 644
5.841
5.442
Cost of Ingredients, $/kg Gain
Cubes Silage Concentrate
(0 $.086/kg)(G> $.052/kg) (@ $.1491/kg) Total
.0803
.0776
.0834
.0824
.0333
.0324
.0338
.0330
value of biological solids
$11.80/kkg at 8%
.8881
.8416
.8710
.8114
= $0.148/kg DM
solids.
1.0017
.9517
.9881
.9268
= $148/kkg
Sludge
0
.169
.360
.688
Sludge
Value
.050/.296/kg
.014/.038/kg
.075/.109/kg
DM =
1. Heinemann, W. W. Personal Communication (May 1976).12
Table 9. ANALYSIS OF DEWATERED BIOLOGICAL SOLIDS -
BEFORE AND AFTER 10 MONTHS STORAGE
Date
Tot
. Sol
q/kq
ids
Vol
. Sol
q/kq
ids
COD
g/kg
NHa-N
g/kg
Org.
q/kg
N
Tot. P
g/kg
Feb. 3, 1975 80.2
Dec. 1, 1975
Top 72.8
Middle 67.7
Bottom 58.9
72.4
56.6
58.4
51.4
95.8
78.8
78.8
73.0
0
3.15
2.8
2.3
5.6
3.2
3.0
3.0
1.29
1.26
0.86
0.99
36
-------
Data on Table 9 indicates that biological decomposition of the solids
occurred during storage in the closed 55 gallon drum over the 10-month
period. This is evidenced by the decrease in total solids and volatile
solids in the stored sludge as well as an actual increase in fixed solids
(total solids minus volatile solids). The biological degradation is also
evidenced by the decrease in COD and the conversion of a substantial
amount of the organic nitrogen into the ammonia nitrogen form. These
degradation changes may result in a decrease in digestibility and metabo-
lizability for the wastewater solids. It may also result in a decrease
in the amount of nitrogen utilizable by livestock if it were incorporated
into a feeding ration since the ammonia nitrogen would probably at least
partially be lost due to volatilization in unconfined storage.
HANDLING OF DEWATERED SOLIDS
Due to the possibility of proceeding to a full scale solids dewatering
system, it was felt that some knowledge of the handling characteristics of
the dewatered solids should be obtained. Samples were obtained of de-
watered sludge during early April 1975, and various experiments on handling
of the highly viscous dewatered solids were conducted. In the first
experiment a cube of dewatered solids was placed on a sheet of metal and
the metal inclined to a point that the solids began to slide down the face
of the slope. A cube two inches on each side containing 8.3% dry solids
moved down the metal sheet 8 inches in two minutes after it was inclined
64 degrees from the horizontal. A three inch cube of sludge containing
11.9% dry solids traveled down an inclined piece of metal 4 inches in two
minutes at an angle of 84 degrees from horizontal, and subsequently fell
the rest of the way.
The maximum height of sludge supported on a 6 inch base was 7.4 inches for
the 8.3% dry solids sludge and 10 inches for the 11.9% dry solids sludge.
Dewatered sludge at 6.7% dry solids was conveyed through a screw conveyor
5 inches in diameter. It was successfully transported through the conveyor
but at an exceedingly slow rate.
These experiments indicate that transport of this dewatered sludge must be
carefully planned before construction of handling facilities. Its viscosity
would allow it to be moved by a bucket type loader or transported on belt
conveyor. It could be pumped by positive displacement pumps, but the pump
drive power must be sufficiently high to overcome the high viscosity and
friction in discharge piping. Conveying the sludge through a screw
conveyor would appear to be difficult to accomplish.
37
-------
SECTION VI
FEASIBILITY FOR FULL SCALE SOLIDS DEWATERING AND
UTILIZATION OF SOLIDS AS CATTLE FEED
A calculation of the feasibility for full scale dewatering of the waste
biological solids at Snokist Growers and utilization of the solids as a
portion of a cattle feeding ration is shown on Table 10. The excess bio-
logical solids production and the basket centrifuge effectiveness are basic
assumptions to this feasibility analysis. Feasibility of the centrifuge
loading was established during the dewatering trials. The capital cost for
installation of the centrifuges, their housing, electrical and other
components, is assumed amortized at 7% over a 20 year basis to provide an
estimated capital cost per kilogram dry solids dewatered. Operation and
maintenance costs and hauling costs were estimated and included in the
total estimated cost for dewatering of the solids and delivery to a point
where it could be utilized as cattle feed. The present cost of disposal
of the solids, which consists of haul ing to a site and land spreading, is
shown. Table 10 shows that the economic feasibility of proceeding with a
full scale dewatering system is heavily dependent upon the dewatered solids
having a positive value to a cattle feeder. The calculated feed value
(Table 7 and Table 8) subtracted from the estimated cost for dewatering
and hauling results in a net estimated cost range for disposal as a cattle
feed which is substantially lower than the present costs of disposal. A
savings of about $9,000 per year could be realized for the Snokist Growers
cannery. A minimum return of $63 per kkg dry solids ($5 per kkg wet
sludge containing 8% solids) would appear to be necessary to give the
program a break even feasibility. It will take an investigation of cattle
feeders' willingness to remunerate Snokist Growers at this minimum level
or higher and actual capital financing charges before a final determination
of the economic feasibility is made.
38
-------
Table 10. FEASIBILITY OF FULL-SCALE DEWATERING
Excess Solids Production
Basket Centrifuge 122 cm x 76 cm
(48 in. x 30 in.)
Capacity
Solids Capacity
Solids Loading Rate
Thickened Sludge Flow @ 25gDS/1
Loading Time
Unloading Time
Cycle Time
Two Centrifuges at 16 hr/day:
Estimated Capital Cost ($255,000)
O&M Cost
Hauling Cost ($1.85/kkg wet sludge)
Total Cost Dewatering and Hauling
Value as Cattle Feed
Net Cost of Sludge Disposal
Present Cost of Disposal ($1.85/kkg
wet sludge)
Net Projected Savings
30,000 kg DS/season
80 g DS/kg Cake
5 g/1 min.
90 1/min.
75% Recovery
3/hour
$24,100/yr
$100/day
80 g DS/kg
$40,000/yr
$92 to $184/kkg DM
$4,500 to $12,000/yr
$21.000/yr
3500 kg DS/
operating
day
450 1
36 kg DS
2.25 kg/min
t = 5 min.
12 min.
8 min.
20 min.
$0.08/kg DS
$0.030/kg DS
$0.023/kg DS
$0.133/kg DS
$0.092 to
$0.148/kg DS
$0.015 to
$0.040/kg DS
$0.070/kg DS
$9,000 to $25,500/yr $0.030 to
$0.085/kg DS
39
-------
SECTION VII
REFERENCES
1. Esvelt, L. A., Aerobic Treatment of Fruit Processing Wastes. Federal
Water Pollution Control Administration, Department of Interior 12060
FAD, October 1969.
2. Esvelt, L. A. and H. H. Hart, "Treatment of Fruit Processing Wastes
by Aeration," Journal Water Pollution Control Federation. Volume 42,
Page 1305, July 1970.
3. Esvelt, L. A., "Aerobic Treatment of Liquid Fruit Processing Waste"
Proceedings First National Symposium on Food Processing Wastes,
Portland, Oregon, April 1970.
4. Grames, L. M. and R. W. Kueneman, "Primary Treatment of Potato Process-
ing Wastes with Byproducts Feed Recovery," Journal Water Pollution
Control Federation, Volume 42, Page 1358, 1969.
5. Jones, R. H., J. T. White and B. L. Damron, Waste Citrus Activated
Sludge as a Poultry Feed Ingredient, EPA-660/2-75-001, February 1975.
6. Richter, G. A., K. L. Sirrine and C. I. Tollefson, "Conditioning and
Disposal of Solids from Potato Wastewater Treatment," Journal of
Food Science, 38-218-1973.
7. Thompson, H. W., Personal Communication, April 1976.
8. Standard Methods for the Examination of Water and Wastewater, 13th
Edition, American Public Health Association, New York 1971.
9. Methods for Chemical Analysis of Water and Wastes, U. S. Environmental
Protection Agency, Office of Technology Transfer, Washington, D. C.,
EPA-625-/674-003 1974.
10. Kitson, R. E. and M. G. Mellon, "Colorimetric Determinations of
Phosphorus as the Molydivaradophosphoric Acid," Ind. & Eng. Chem. 16:
379-383 (1944).
11. Mood, D. M. and F. A. Graybill, Introduction to the Theory of Statistics,
2nd Ed. McGraw-Hill, New York (1963).~
12. Heinemann, W. W., Personal Communication (May 1976).
40
-------
SECTION VIII
APPENDIX
This appendix contains Tables A-l through A-13 which present the data in
greater detail than was provided in the report text. These data provide
backup for the analyzed results for biological solids thickening, basket
centrifuge sludge dewatering performance and cattle feeding presented and
discussed in earlier sections of this report.
41
-------
Table A-l. SLUDGE DEWATERING - PILOT (36 cm dia, 9.9 1) CENTRIFUGE
Date
10/16/74a
10/19/74a
10/21
10/22
10/23
10/24
10/25
10/26
10/29
10/30
10/31
11/1/74
11/2
11/8
11/9
11/11
11/12
11/13
11/14
11/15
11/18
11/19
11/20
11/21
11/22
11/25
11/26
11/27
12/2/74
12/3
12/4
12/5
12/6
12/9
12/10
12/11
12/12
12/13
a
a
a
a
a
a
a
a
a
a
a
b
b
a
b
a
b
b
b
b
b
b
b
b
b
b
b
b
b
b
b
c
c
c
c
c
c
Feed Rate
1/mln
8.5
7.6
7.5
7.1
7.8
8.8
9.0
4.7
8.0
8.3
6.4
10.5
8.3
3.4
3.1
3.5
3.1
6.4
5.2
5.8
6.4
6.0
8.9
6.4
1.4
4.5
1.11
1.33
4.1
2.7
2.0
2.7
3.2
2.9
3.7
5.2
1.6
2.0
1.1
t, min
1.2
1.3
1.3
1.4
1.3
1.1
1.1
2.1
1.2
1.2
1.6
0.9
1.2
2.9
3.2
2.8
3.2
1.6
1.9
1.7
1.6
1.6
1.1
1.6
6.9
2.2
8.9
7.5
2.4
3.6
5.1
3.7
3.1
3.4
2.7
1.9
6.4
4.9
8.8
Feed SS
g/i
7.1
7.9
5.8
7.2
6.9
6.2
5.8
5.3
3.7
5.2
5.6
6.0
6.7
4.6
6.0
4.4
5.7
5.6
6.9
6.7
5.3
6.8
7.05
7.3
24.00
7.0
24.70
22.70
5.56
4.0
5.7
5.5
5.9
6.7
3.7
6.2
6.5
5.4
5.8
Cake
Total
gDS
710
790
680
750
800
780
720
830
680
670
660
720
710
760
800
620
700
690
600
610
600
630
580
660
630
670
760
680
650
740
740
650
700
640
580
620
720
730
750
Cake
Conc'n*
qOS/kq
89.3
91.6
83.7
82.2
85.5
85.7
81.0
89.5
78.8
78.3
78.1
77.7
76.0
90.6
90.7
78.6
77.5
75.8
71.4
72.7
71.3
68.1
67.3
70.7
69.4
75.8
86.1
75.1
71.6
79.5
83.1
77.8
81.5
72.7
65.2
67.0
81.3
78.1
84.8
Max Initial
Cake Centrate
Conc'n** Concn,o/l
113
103
94
98
89
96
105
99
92
98
94
115
94
101
97
85
87
85
90
87
85
84
84
81
108
83
99
85
97
92
103
95
94
95
81
92
88
95
91
.6
.4
.3
.35
.4
.4
.4
.2
.2
.38
.39
.50
.5
.12
.32
.15
.27
.4
.5
.55
.45
.55
1.0
.6
-
.47
1.4
.85
.43
.14
.25
.25
.3
.4
.26
.5
.2
.2
.17
* Ave. of 3 samples following mixing of cake discharge
** Sample from cake at periphery of centrifuge
a 1240 g's at centrifuge periphery (2500 rpm)
b 1340 g's at centrifuge periphery (2600 rpm)
c 880 g's at centrifuge periphery (2100 rpm)
0 Flotation Thickened Sludge Feed
42
-------
Table A-2. SLUDGE DEWATERING - PROTOTYPE (76 cm dia, 113 1) CENTRIFUGE
Date
12/17/74
12/18
12/19
12/20
1/20/75
1/21
1/22
1/23
1/24
1/27
1/28
1/29
1/30
1/31
2/3
3/19
3/20
3/21
3/24
3/25
3/26
3/27
3/31
4/1
4/2
4/3
4/4
4/7
4/8
4/9
4/10
4/11
4/14
Feed Rate
1/min
103
52
56
31
60
72
90
108
89
48
59
52
66
61
72
113
53
58
65
84
56
64
58
46
55
25
27
20
29
44
38
36
29
t, min
1.1
2.2
2.0
3.7
1.9
1.6
1.3
1.1
1.3
2.4
1.9
2.2
1.7
1.9
1.6
1.0
2.1
1.9
1.7
1.4
2.0
1.8
2.0
2.5
2.1
4.5
4.2
5.7
3.8
2.6
3.0
3.1
3.9
Feed SS
g/i
2.7
2.75
3.3
3.1
3.75
5.3
5.1
5.4
5.3
3.4
4.8
4.8
4.1
4.1
4.0
1.8
1.9
2.7
2.6
2.6
2.6
2.6
2.6
18.5@
19.6(3
20.0@
14.2(3
14.3(3
17.40
14.50
17.50
17.3@
17.60
Cake
Total
kg DS
8.2
9.6
9.7
10.6.
8.0
9.5
8.1
9.6
10.0
9.8
9.0
9.1
8.4
8.5
8.6
5.8
8.9
7.2
8.2
8.1
8.5
8.3
8.6
7.9
9.8
8.7
8.6
8.9
9.5
10.9
10.0
9.9
10.3
Cake*
Concn
gDS/kg
72.2
85.1
85.4
93.3
70.7
83.7
83.5
84.6
88.2
86.2
79.2
80.0
74.2
74.6
76.2
50.9
78.4
63.4
72.5
71.4
74.6
73.0
75.9
96.0
86.3
76.3
75.7
78.6
83.6
96.1
88.6
87.3
90.8
Max**
Cake Concn
g/kg
140
117
148
112
117
161
168
152
158
122
112
115
102
129
109
116
115
165
134
138
114
112
127
162
154
167
157
128
136
145
176
141
179
*Ave. of 3 samples following mixing of cake discharge
**Sample from cake at periphery of centrifuge
0 Flotation Thickened Sludge Feed
43
-------
Table A-3. CENTRIFUGE PERFORMANCE
Date
Feed SS, g/1
Cake Sol. gDS/kg
Hydraulic Retention Time
10/19
7.94
91.6
1.30
11/1
6.0
77.7
0.94
10/26
5.3
89.5
2.1
12/11
6.5
81.3
6.4
11/26
22.7
75.1
7.5
12/9
3.7
65.2
2.7
t, min.
Solids Retention Time 15.0 12.3 35.8 81.3 24.2 46.6
SRT, min
Time, min/Centrate SS, g/1
3.7/0.40
6.0/0.37
8.6/0.34
11.6/0.47
13.8/1.59
16.6/4.12
18.9/5.8
3.0/0.47
4.8/0.47
6.6/0.53
8.4/0.65
10.1/0.97
11.9/2.07
13.7/3.46
15.5/4.01
7.9/0.30
11.7/0.13
14.7/0.18
20.4/0.16
24.4/0.19
28.4/0.27
32.8/0.60
37.9/0.60
40.6/1.99
42.3/3.07
17.3/0.22
27.5/0.23
38.8/0.20
53.1/0.22
67.6/0.78
80.7/3.93
18.7/0.9
21.3/0.72
23.3/0.94
27.0/10.7
30.4/17.4
33.8/19.5
6.7/0.21
12.0/0.26
17.4/0.27
22.8/0.30
27.9/0.34
33.1/0.36
38.2/0.41
43.5/0.55
48.3/1.11
54.1/1.56
-------
Table A-4. FLOTATION THICKENER PERFORMANCE (9 m DIA. CIRCULAR THICKENER)
(Pressurized Recycle Flow = 950 1/min )
Date
11/22/74
11/25
11/26
11/27
12/2
12/3
4/2/75
4/3
4/4
4/7
4/8
4/9
4/10
4/11
Hydraulic
Loading
1/min sq m
15
31
15
31
31
15
31
31
31
31
31
31
31
31
Solids
Removal
kg DS/hr-sq. m
3.7
5.8
3.5
8.4
4.3
3.2
2.7
2.8
1.7
1.1
2.3
2.3
2.1
2.3
thickened
Sludge Concn
gDS/1
28.9
23.9
28.1
23.7
22.1
27.3
22.3
20.3
19.5
19.9
23.3
17.7
22.9
24.4
Thickener
Effluent Com
gDS/1
0.16
0.17
0.17
0.15
0.3
0.2
0.06
0.06
0.28
0.65
0.3
0.35
0.41
0.26
45
-------
Table A-5. RESULTS OF METABOLISM TRIALS, DRY MATTER
DIGESTIBILITY (DMD) AND DRY MATTER
METABOLIZABILITY (DMM)
Steer
No.
1
2
3
4
5
6
7
8
Ration
Control Low Waste
DMD DMM DMD DMM
70.8
67.2
75.1
76.1
70.2
69.8
73.1
72.9
Tabl
65
62
67
69
66
65
67
67
e A-6.
Steer Control
No. DE ME
1 73.
2 73.
3 72.
4 79.
5 67.
6 73:
7 71.
8 74.
12
96
20
50
63
73
51
12
70.02
70.32
65.61
75.86
65.83
71.36
67.98
70.71
.8 71.7
.0 65.2
.2 74.4
.3 73.5
.3 70.7
.1 72.2
.4 73.8
.4 73.7
RESULTS OF
(DE)
Low Level
DE
71.62
69.79
73.88
75.29
76.05
77.17
74.91
72.44
65.4
58.7
69.3
68.2
63.4
66.3
67.0
66.6
Med.
DMD
72.1
70.5
73.5
72.8
71.4
71.9
72.0
69.6
METABOLISM TRIALS,
AND METABOLIZABLE
Sludge
ME
68.29
65.69
71.38
72.53
71.82
74.47
71.10
68.83
, Waste
DMM
64.8
64.6
68.0
66.5
66.6
67.2
64.7
63.5
DIGESTIBLE
ENERGY (ME)
Ration
Med. Level Sludge
DE ME
70.67
68.98
68.88
69.53
71.85
79.24
70.76
65.73
67.23
64.79
64.93
64.78
68.23
75.57
66.91
62.66
High Waste
DMD DMM
67.2
65.5
75.1
74.3
68.8
68.6
71.7
69.2
ENERGY
High Level
DE
65.22
71.71
77.51
76.43
68.30
72.40
71.35
70.76
59.8
58.1
68.2
66.6
62.3
63.2
66.2
64.5
Sludge
ME
59.91
67.24
72.65
71.37
63.11
69.11
67.38
67.17
46
-------
Table A-7. INDIVIDUAL WEIGHT GAIN RECORDS - FINISHING FEED STUDIES
Steer
No.
Control
12
18
32
42
83
96
12/19/74
355.5
388.5
354.0
378.5
360.5
365.0
2.3% Biological Sol
36
43
62
95
105
118
387.0
349.5
351.5
376.5
361.0
354.0
4.6% Biological Sol
31
69
81
97
98
106
374.5
365.5
352.0
394.0
367.0
377.0
8.9% Biological Sol
15
19
56
78
91
102
367.5
380.5
347.0
394.5
351.0
379.5
1/16/75
392.0
436.0
390.5
393.0
408.0
373.5
ids
419.0
396.0
386.0
419.5
398.0
391.0
ids
424.0
396.0
382.0
422.5
376.5
404.5
ids
408.0
410.0
380.5
431.5
356.5
407.5
2/12
421.5
474.5
425.0
408.5
450.0
409.5
466.5
445.5
415.0
449.5
421.5
431.0
466.0
439.5
409.0
460.0
416.5
418.5
453.0
429.0
407.0
478.5
385.5
438.0
Weight as
3/12
452.5
521.5
455.0
463.5
493.0
444.5
509.5
497.5
459.5
490.0
470.5
464.5
514.0
472.0
440.5
499.0
446.5
460.5
504.5
453.0
449.0
516.0
421.0
436.5
of, kg
4/9
492.5
557.0
489.0
498.5
527.0
474.5
554.5
501.0
497.0
526.5
507.0
500.0
557.5
510.0
476.5
534.0
477.5
494.5
534.5
480.0
479.5
558.5
452.5
493.0
5/7
529.0
579.0
512.5
543.0
557.5
490.5
573.5
542.5
527.0
565.5
530.0
529.5
596.5
557.5
507.0
552.0
503.5
519.0
577.0
511.5
521.0
596.5
477.5
544.5
6/2
497.5
610.0
541.5
575.5
592.0
513.5
589.0
569.0
549.5
595.5
550.5
544.5
620.5
567.5
533.0
567.5
533.5
540.5
599.5
538.5
543.5
622.0
490.5
546.0
47
-------
Table A-8. 165 DAY FINISHING FEED STUDIES
CO
Steer
No.
12
18
32
42
83
96
36
43
62
95
105
118
Beg.
Wt.
kg
355.5
388.5
354.0
378.5
360.5
365.0
387.0
349.5
351.5
376.5
361.0
354.0
End
Wt.
kg
497.5
610.0
541.5
575.5
592.0
513.5
589.0
569.0
549.5
595.5
550.5
544.5
Gain
kg/d
0.86
1.34
1.14
1.19
1.40
0.90
1.22
1.33
1.20
1.33
1.15
1.15
D.M.
Intake
kg/
day
8.33
9.98
8.40
6.93
9.52
7.25
2.3%
9.73
9.10
8.79
8.96
9.34
8.13
D.M.
Intake
kg/kg
ave. wt
"Control
3.22
3.30
3.09
2.40
3.30
2.72
Biological
3.29
3.27
3.22
3.04
3.38
2.98
Wt. Gain
DM Intake
kg/kkg
103
135
135
172
147
124
Solids
126
146
137
148
123
142
USDA
Grade'
G (8)
C (5)
LC (6)
G (8)
LC (6)
LC (6)
C (5)
C (5)
LC (6)
HC (4)
HP (1)
C (5)
Yield
Grade
3
4
3
1
2
3
4
3
2
3
4
3
Marbl ing
Score2
SI- (15)
Mod ( 5)
Sm+ (10)
SI- (15)
Sm+ (10)
Sm (11)
Mod ( 5)
Mod ( 5)
Sm (11)
Mod+ (4)
Ab (2)
Mod (5)
1. Scale for USDA Grades: HP = High Prime = 1; P = Prime = 2; LP = Low Prime = 3; HC = High
Choice = 4; C = Choice = 5; LC = Low Choice = 6; HG = High Good = 7; G = Good = 8; LG =
Low Good = 9.
2. Marbling Score: T = Trace = 17; SI = Slight = 14; Sm = Small = 11; Mt = Modest = 8;
Mod = Moderate = 5; Ab = Abundant = 2.
-------
Table A-8 (continued). 165 DAY FINISHING FEED STUDIES
VO
Steer
No.
31
69
81
97
98
106
15
19
56
78
91
102
Beg.
Wt.
kg
374.5
365.5
352.0
394.0
367.0
377.0
367.5
380.5
347.0
394.5
351.0
379.5
End
Wt.
kg
620.5
567.5
533.0
567.5
533.5
540.5
599.5
538.5
543.5
622.0
490.5
546.0
Gain
kg/d
1.49
1.22
1.10
1.05
1.01
0.99
1.41
0.96
1.19
1.38
0.84
1.01
D.M.
Intake
kg/
day
4.faft
10.23
9.46
8.18
8.97
8.30
8.03
8.9%
10.32
7.87
9.08
9.34
7.18
8.03
D.M.
Intake
kg/kg
ave. wt
biological
3.39
3.35
3.05
3.08
3.04
2.89
Biological
3.52
2.83
3.37
3.03
2.82
2.86
Wt. Gain
DM Intake
kg/kkg
bonds
146
129
134
117
122
123
Solids
136
122
131
148
118
126
USDA
Grade1
LC (6)
LC (6)
LC (6)
C (5)
LC (6)
C (5)
HC (4)
HG (7)
LC (6)
LC (6)
G (8)
HG (7)
Yield
Grade
3
4
2
3
4
4
2
2
3
3
2
3
Marbling,
Score^
Sm (11)
SI (14)
Sm (11)
Mod (5)
Sm- (12)
Mod (5)
Mod (5)
S1+ (13)
Mod (5)
Sm (11)
SI- (15)
Sm (11)
-------
Table A-9. CONTENT OF BIOLOGICAL SOLIDS
DRY SOLIDS BASIS mg/mg
Date
8/27/74
9/4
9/10
9/17
9/24
10/3
10/15
10/22
10/29
10/30/74
11/6
11/13
11/20
12/4
12/11
1/20/75
1/27
2/3
3/20
3/25)
) D
3/25)
4/1 ) D
) Thickener
4/1 ) Float
vss
.901
.896
.889
.883
.875
.888
.922
.910
.907
.901
.927
.894
.886
.890
.862
.892
.902
.893
.864
.871
.886
.889
Org. N
.059
.066
.068
.067
.067
.070
.070
.070
.069
..069
.076
.077
Org. P
.016
.016
.015
.014
.013
.014
.016
.016
.015
.014
.015
.016
.016
COD
1.28
1.29
1.26
1.25
1.24
1.23
1.29
1.27
1.33
1.28
1.25
—
1.22
1.22
1.16
1.19
1.19
1.12
1.12
1.14
1.26
1.27
D = duplicate analyses
50
-------
Table A-10. AMINO ACID ANALYSIS OF BIOLOGICAL SOLIDS, DM BASIS*
Ami no Acid Nanomoles per mo
Aspartic acid 199.2
Three-nine 128.0
Serine 111.3
Glutamic acid 295.1
Proline 92.0
Glycine 202.1
Alanine 266.7
Cystine 51.8
Valine 181.4
Methionine 64.4
Isoleucine 94.1
Leucine 170.6
Norleucine 24.8
Tyrosine 143.3
Phenylalanine 95.6
Lysine 94.9
Histidine 31.6
i
Arginine 63.8
Ornithine & Tryptophane 129.6
*0n basis of amino acid content, biological solids contains
between 20 and 27% protein.
51
-------
Table A-11.HEAVY METALS AND ARSENIC IN BIOLOGICAL SOLIDS AND
SELECTED ANIMAL TISSUES OF STEERS FED 165 DAYS
Sample Identity
Cd
Residue, ppm as Sampled
Cu Fe Pb Sn
Zn As
Steers - Control
83-adipose
kidney
liver
96-adipose
kidney
liver
19-adipose
kidney
liver
78- adipose
kidney
liver
.015
.69
.10
.02
.095
.04
Steers
.03
.83
.14
.01
.78
.22
Biological
Composite of
Sludge from Entire
Feeding Period
May 1975 Sample <
Sept. 1973 Sample
6
.15
3.56
3.40
.13
2.94
39.5
- 8.9%
.07
.74
7.9
.20
2.32
34.3
Solids
120
60
90
2.6
56
31
4.6
56
52
Biological
5.0
60
39
5.9
84
60
Residue ppm
19,500
6,100
.15
.40
.25
.35
.48
.25
Solids
.02
.59
.40
.08
.76
.48
Dry Sol
50
60
.3
3.5
.9
1.4
.15
4.9
2.2
3.5
2.9
.8
4.7
7.3
ids
330
400
.70 <.5
19.2 <.5
14.8 <.5
4.9 <.5
17.0 <.5
30.4 <.5
5.1 <.5
20.8 <.5
33.0 <.5
1.1 <.5
19.2 <.5
37.6 <.5
110 3.5
4.3
200
52
-------
Table A-12. PESTICIDE RESIDUES IN WASTE BIOLOGICAL SOLIDS
Sampling*
Time
1
2
3
4
5
Averages
4/17/75 Clarifier Sludge
4/17/75 Centrifuge Sludge Cake
Residue
p,p'-DDE
Thiodan I
Thiodan II
p,p'-DDE
Thiodan I
Thiodan II
p.p'-DDE
Thiodan I
Thiodan II
p.p'-DDE
Thiodan I
Thiodan II
p.p'-DDE
Thidoan I
Thiodan II
p.p'-DDE
Thiodan I
Thiodan II
#1
p.p'-DDE .011
Thiodan I .014
Thiodan II .022
p.p'-DDE
Thiodan I .006
Thiodan II .013
Cone.
ppm D.S.
.054
.031
.090
.040
.029
.093
.031
.024
.072
.047
.034
.093
.044
.030
.096
.043
.030
.089
#2
.012
.022
.039
.009
.011
.022
*Each "sampling time" is composed of a composite of weekly samples,
53
-------
Table A-13. PESTICIDE RESIDUE IN ADIPOSE (OMENTAL FAT),
KIDNEYS AND LIVERS OF STEERS FED 165 DAYS
Steer Nume
and Ration
83 - Control
96 - Control
19 - 8.9%
Biological
Solids
78 - 8.9%
Biological
Solids
Sample
Type
Adipose
Kidney
Liver
Adipose
Kidney
Liver
Adipose
Kidney
Liver
Adipose
Kidney
Liver
Residue present, ppm
Residue
p.p'-DDE
Dieldrin
Thiodan I
Endrin
Thiodan I
None
p.p'-DDE
Dieldrin
Thiodan I
Endrin
Thiodan I
None
p.p'-DDE
Dieldrin
Thiodan I
Thiodan I
Endrin
None
p.p'-DDE
Dieldrin
Thiodan I
None
None
Lipid
.059
.014
.003
.004
—
—
.100
.022
.003
.003
—
—
.080
.029
.003
—
—
.066
.028
.003
—
___
Tissue
.056
.013
.003
.004
.001
—
.080
.018
.002
.002
.001
—
.073
.026
.003
.055
.002
—
.055
.023
.002
—
___
54
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/2-76-253
2.
3. RECIPIENT'S ACCESSIOf*NO.
4. TITLE AND SUBTITLE
FRUIT CANNERY WASTE ACTIVATED SLUDGE AS A CATTLE FEED
INGREDIENT
5. REPORT DATE
September 1976 (Issuing Date)
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
8. PERFORMING ORGANIZATION REPORT NO.
Larry A. Esvelt
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Snokist Growers
Yakima, WA
10. PROGRAM ELEMENT NO.
1BB610
11. CONTRACT/GRANT NO.
S-803307
12. SPONSORING AGENCY NAME AND ADDRESS
13. TYPE OF REPORT AND PERIOD COVERED
Industrial Environmental Research Laboratory-Cin., OH
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
14. SPONSORING AGENCY CODE
EPA/600/12
15. SUPPLEMENTARY NOTES
16. ABSTRACT
». *-i»ij i n*-»w i t , . _ ,
The feasibility of sludge disposal, from a fruit processing waste activated sludge
treatment system, by dewatering and using the dewatered biological sludge solids as
cattle feed was evaluated by Snokist Growers at Yakima, Washington, Dewatering of
the biological sludge utilizing pilot-scale and prototype-scale basket centrifuges
resulted in consistently dewatering to 7-1/2% to 9% dry solids. Digestibility and
metabolizability of rations containing 2.3% and 4.5% biological solids appeared
equal to a control ration, but a ration containing 9.2% biological solids appeared
lower. Twenty-four uniform yearling steers were divided into four lots of six each
and finish fed a control ration and rations containing 2.3%, 4.6%, and 8.9% sludge
solids on a dry matter basis for 165 days. They did not show any adverse effects of
the sludge incorpration into their rations. It appeared that a low quantity of
sludge (2.3% dry solids) actually enhanced the weight gain performance and carcass
quality of these animals. The cost of a dewatering installation will require that
the cannery receive remuneration for use of the waste activated sludge as cattle
feed in order to make a full-scale dewatering project feasible. The calculated value
of the biological solids incorporated into the rations was in the range of $0.092 t
------- |