SETOV
                                  United States
                                  Environmental Protection
                                  Agency
                                   Industrial Environmental Research
                                   Laboratory
                                   Cincinnati OH 45268
                                  Research and Development
                                   EPA-600/S2-81-112  Aug. 1981
Project  Summary
                                  Protein  Recovery  from
                                  Beef  Packing   Effluent

                                  John C. Ward, Walter Adams, and H. Chr. Isaksen
                                   The wastewater from a large beef
                                  packing plant, containing 3000 mg/l
                                  BOD5 and 2,500 mg/l of suspended
                                  solids was treated in a physiochemical
                                  process that recovers protein. This
                                  process removed 58% of the total
                                  nitrogen, 80% of the oxygen demand
                                  and suspended solids, and 94% of the
                                  fat, oil and grease. The discharge of
                                  BODS was reduced to less than 3
                                  pounds per head of beef slaughtered.
                                  For every pound of BOD5 entering the
                                  wastewater treatment plant, 0.77
                                  pounds of product was recovered with
                                  a composition of 38% protein, 11%
                                  grease and oil, 27% inorganic solids,
                                  and 24% other  solids (dry weight
                                  basis). About 2 pounds of protein
                                  were recovered per head. Total cost
                                  was $3 per 1,000 gallons (44% capital
                                  costs). A price of 420 per pound of
                                  protein would pay all costs. The figures
                                  given above were observed in a full
                                  scale plant and  should not change
                                  significantly with different size waste-
                                  water treatment plants. This waste-
                                  water treatment process can be used
                                  as a pretreatment process for beef
                                  packing effluent prior to discharge to a
                                  sewage treatment plant.
                                   Seven different beef packing waste-
                                  water treatment processes including
                                  other methods of protein recovery are
                                  discussed and compared in the full
                                  report.
                                   This Project Summary was devel-
                                 oped by EPA's Industrial Environ-
                                 mental Research  Laboratory, Cincin-
                                 nati, OH, to announce key findings of
                                 the research project that is fully docu-
                                 mented in a separate report of the
                                  same title (see Project Report ordering
                                  information at back).

                                  Introduction
                                    Beef packing effluents pose a consid-
                                  erable challenge to wastewater treat-
                                  ment technology. Several water quality
                                  parameters are listed below in Table 1
                                  along with their average concentrations
                                  in domestic wastewater and the average
                                  concentrations observed in the effluent
                                  from this beef packing plant.
                                    Clearly the oxygen demand of beef
                                  packing effluent is 20 to 30 times that of
                                  domestic wastewater, so that at least
                                  95% removal would  be necessary to
                                  reduce the oxygen demand of beef
                                  packing effluent to that of  untreated
                                  domestic wastewater. In addition, the
                                  quantity of suspended solids is over 10
                                  times that of domestic wastewater. As a
                                  final complication, beef packing plants
                                  are  not usually operated continuously,
                                  so that conventional biological waste-
                                  water treatment techniques leave a
                                  great deal to be desired.
                                    This lack of continuous operation
                                  indicates  the desirability of  a  physio-
                                  chemical wastewater treatment process.
                                  In addition, it would be highly desirable
                                  if some cost recovery were possible
                                  from the sale of the relatively large
                                  quantities of sludge that can be expected.
                                    The Alwatech  process is  a  physio-
                                  chemical wastewater treatment process
                                  that also recovers protein (from the beef
                                  packing effluent) which can be sold to
                                  partially recover the cost of wastewater
                                  treatment. The process uses sulfuric
                                  acid, H2S04, for pH reduction, calcium
                                  lignosulfonate for protein precipitation.

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 Table 1    Comparison of Beef Packing and Domestic Wastewaters

                                      Average Concentration, mg/l
Water Quality Parameter
COD
5-Day, 20°C BOD
Suspended Solids
in
domestic
wastewater
150
140
235
in beef
packing
effluent
4,610
2.940
2,460
and calcium hydroxide, Ca(OH)2, for
both effluent and sludge neutralization.
  This report gives the results of a full
scale evaluation of the Alwatech process
installed at a large beef packing plant in
the United States. While the Alwatech
process is not necessarily limited to
treatment of and protein recovery from
beef packing effluents, this  report is
based on beef packing effluent treat-
ment  and protein recovery. Other efflu-
ents treated by the Alwatech process
include those from poultry and  pig
abattoirs.

Unit Waste Production
  Table 2 shows the unit waste produc-
tion rates for 6 different waste products.
From this table, it is clear  that the
quantities of the last 3 wastes listed are
minor when compared to the quantities
of the first 3 wastes listed. Because the
average live weight of beef killed at this
plant is 1,040±15 pounds, the quantity
of waste produced per 1000 pounds live
weight killed is close  to the quantity
produced per head of beef. About 350
gallons of wastewater are produced per
head.

Brief Description of the
System Evaluated
  The plant wastewaters, excluding
those from the stock  pens and con-
densers, are sent to an existing clarif ier
which was modified to also balance flow
volumes.  The pH  of the effluent from
this clarifier is reduced with H2S04 to
between 2 and 3. Calcium lignosulfonate
is added to the wastewater in quantities
that are directly proportional to the COD
concentration. Following this protein
precipitation step, the resulting floe
containing protein, fat, and suspended
material is separated in two dissolved
air flotation tanks.
  Following this separation, the pH of
the liquid effluent is raised to about 4
with Ca(OH)2 and then mixed with other
wastewater streams that are not treated
by this process. The pH of the resulting
mixture is about 7 and consequently is
suitable for additional treatment by
biological wastewater treatment
processes.

  The sludge is also neutralized with
Ca(OH)2 to an initial pH of 9.1 which
eventually drops to a pH of 7.6. The
sludge is  dewatered in a centrifuge,
dried and sold.

Table 2.    Unit Waste Production
       Waste Produced
Conclusions
  For a beef packing effluent with an
initial BODS averaging 3,000 mg/l, the
Alwatech process is capable of removing
over 80% of the oxygen demand, about
86% of the suspended solids, and 94%
of the fat, oil, and grease. Average
removals of 41 % of the ammonia N and
63% of the organic N were observed.
The solids concentration of the sludge
produced by this flotation process aver-
ages about 9%.
  The optimum calcium lignosulfonate
dose is about 5% of the influent COD
concentration although additional work
may later show that this dose can be
reduced somewhat. While the optimum
pH range varies from  about 2 to  less
than 3, for incoming COD concentrations
greater than about 1,800 mg/l, it is less
                   Ib
               10*lbLWK*
  5-day, 20°C BOD
  Total suspended solids
  Grease and oil
  Organic nitrogen
  Ammonia nitrogen
  Phosphate
                  6.51
                  5.44
                  1.26
                  0.28
                  0.18
                  0.04
 •lb/103 Ib live weight killed

Scope of This Project
  The major water quality parameters
used to measure the effectiveness of
this  process are (listed in order of
decreasing  concentration):
  COD
  BOD5
  Total suspended solids
  Total volatile solids
  Volatile suspended solids
  Grease and oil
  Organic nitrogen
  Ammonia nitrogen
  Phosphate
The data summarized in this report
cover a period of 8 months of operation.
Because both the BOD5 and suspended
solids loadings were 50% greater than
the values  used in the initial design, a
certain amount of additional research
and development work was necessary
during this 8 month period. Near the end
of the 8 month data logging interval, 2
perf orma nee tests of 2 weeks each were
conducted.  The results obtained during
these 2 trial periods may be a  better
indication  of the  capabilities of this
process than the averages observed
during the 8 month duration of the data
collection summarized in this report.
expensive to use pH values nearer 2
because lower calcium lignosulfonate
doses can be used. While chemical
costs increase as the influent COD con-
centration increases, the rate of increase
is less at oH values near 2.
  While the centrifuge efficiency was
about 94% for water, it was only 52% for
total solids, 66% for protein and 21 % for
oil and grease. When the centrifuge
reject solution is recirculated back to the
plant  influent, the  incoming COD is
increased 32%, the influent suspended
solids are increased 29%, and  the
influent grease and oil is increased 36%
to 52%.
  Total observed operating costs were
470 per head or $1.68 per 1,000 gallons
of wastewater treated. About 2 pounds
of protein were recovered per head, so
this protein would have to sell for 23.50
per pound in order to cover all operating
costs. However,  operating costs could
be reduced to 400 per head by using less
calcium lignosulfonate.  Calcium
lignosulfonate accounted for 39% of the
total operating costs followed by 25%
for  labor,  15%  for hlsSO^ 10% for
Ca(OH)2, 9% for energy (1979), and 2%  t
for repairs.

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  Biological  activity in the clarifier
balancing tank preceding the Alwatech
plant had an influence on oxygen
demand and nitrogen removal efficien-
cies. This biological activity  is believed
due to the paunch and gut contents,
relatively long detention time (1.5-2
hours), and high effluent temperatures
(100° to 125°F). However, the detention
time cannot be reduced below 1.5 hours
as fat skimming and bottom sludge
removal would both suffer.
  The discharge of 5-day,  20°C BOD
from this beef packing  plant has been
reduced to less than 3 pounds per head.
For every pound of 5-day,  20°C BOD
entering the Alwatech plant, an average
of 0.77 pounds of product was recovered
with  an average composition of 38%
protein, 11% grease and oil, 27% fixed
solids, and 24% other  solids  on  a dry
weight basis.

Monthly Average Effluent
Concentrations
  The monthly average effluent con-
centrations were 806±  413  mg/l BOD,
46± 24 mg/l organic nitrogen, 41 ± 13
mg/l ammonia nitrogen, and 15  ± 11
  ng/l phosphate where the first figure is
the average (arithmetic mean) and the
second figure is the arithmetic standard
deviation. Both the grease and oil and
the total suspended solids  effluent
concentrations were so variable (coef-
ficient of variation >1)  that they were
better represented  by a tog normal
(geometric)  frequency distribution.
Accordingly, the suspended solids ef-
fluent concentration geometric mean
was 309 mg/l with a geometric mean
standard deviation of 2.2. The grease
and oil effluent concentration geometric
mean was 40 mg/l with a geometric
standard deviation of 4.8.

Ammonia and Organic Nitrogen
  The ratio of the standard deviation/
mean for both the influent ammonia and
organic nitrogen concentrations was
the same (0.48).  The  total nitrogen
concentration averaged 210 mg/l with
a standard deviation of 74 mg/l giving a
standard deviation/mean ratio of 0.35
which indicates that the total influent
nitrogen concentration was less variable.
The average removal of total nitrogen
was 58% with a standard deviation of
21% giving a standard deviation/mean
ratio of 0.36 which indicates that the %
removal of total nitrogen was also less
I variable. Total nitrogen =  ammonia +
organic nitrogen because it  is assumed
that nitrate plus nitrite nitrogen is
negligible in comparison in this waste-
water.
  On the average,41% of the influent
ammonia nitrogen concentration of 82
mg/l was  removed and 63% of  the
influent organic nitrogen concentration
of 128 mg/l was removed. Consequently,
the ammonia and organic nitrogen con-
centrations in the effluent were both
about 48 mg/l each so that the nitrogen
effluent concentration was 95 mg/l.
  An equation developed during  the
course of a laboratory investigation of
protein  recovery using chitosan was
modified so that the % removal of organic
nitrogen could be predicted as a func-
tion  of temperature,  pH, calcium ligno-
sulfonate dose, and the COD concentra-
tion  in the wastewater influent. Com-
parison of  the % organic nitrogen re-
movals calculated by this equation with
the observed data gave a correlation
coefficient of 0.84. Percent COD remov-
al and  % organic nitrogen removal are
linearly related with a correlation coeffi-
cient of 0.82.

Phosphate and Fecal Coliforms
  The average rempval of phosphate
was 49% which reduced the average
influent concentration of 17 mg/l P to 9
mg/l P. A concentration of 6,600 fecal
coliforms per 100 ml were observed in
the effluent.

Solids
   Bottom sludge from the air flotation
tanks  is 28% of the total wet sludge
volume produced. Total dried sludge
production averaged 5 pounds  per
1,000 pounds live weight killed.  The
dried sludge was 38% protein, 27%
inorganic solids, 11% grease and oil,
and 24%other. The solids concentration
of the dried sludge was 88% and there-
fore the water concentration was 12%.
The dried sludge is sold for use in animal
feeds.

Material Balances of Pollutants
  On the average, 27.5 gallons of  wet
sludge were produced per 1,000 gallons
of wastewater treated. Ninety percent of
the wet sludge becomes centrifuge
reject solution and  10% becomes  de-
watered sludge. The concentrations of
COD, grease and oil, and suspended
solids in the centrifuge reject solution
averaged 50,000 mg/l, 5,860 mg/l,  and
21,000 mg/l, respectively. Consequently,
pumping the centrifuge reject solution
back into the  plant  influent increased
the incoming COD 32%. Eighty-three
percent of the incoming COD is removed,
and of the amount removed, 62% winds
up in the  dewatered sludge and the
remaining  38% leaves in the centrifuge
reject solution.
  Based on separate disposal of the
centrifuge  reject solution, 81% of the
suspended solids is removed, and of the
amount removed, 64% winds up in the
dewatered sludge and the remaining
36% leaves in  the centrifuge reject
solution. Consequently, pumping the
centrifuge  reject solution back into the
plant influent would increase the influ-
ent suspended solids 29%.
  Again based on separate disposal  of
the centrifuge reject solution, 94%  of
the grease and oil is removed, and of the
amount removed, 53% winds up in the
dewatered sludge and the remaining
47% leaves in  the centrifuge reject
solution. The grease and oil concentra-
tion in the dewatered sludge is about
6%. Recirculation of the centrifuge
reject solution back to the plant influent
would increase the influent grease and
oil by roughly 44%.

Filter Belts
  Initially it was attempted to dewater
the wet sludge using filter belts, but
these were found to perform unsatisfac-
torily on the wet sludge produced,  so
they were  replaced with a centrifuge.

Economics
  Virtually all cost inputs to the process
were measured including labor, cost of
repairs and  maintenance, energy, and
chemicals. Operating costs were $1.68
per thousand gallons treated. The capital
costs for an 800,000 gpd plant are  an
additional  $1.32 per thousand gallons
treated,  so the  total cost is $3.00 per
1,000 gallons treated. The capital costs
(and consequently the total costs) include
property taxes, interest recovery  of
principal, and insurance. These costs do
not give any credit for the  protein
recovered and sold.
  About 2 pounds of protein are recovered
per head. The average quantity of waste-
water treated in  the Alwatech plant was
276 gallons per head.  Therefore the
average cost of treating this wastewater
was 830 per head, so that the protein
recovered would have to sell for about
420 per pound of protein  in order  to
recover all costs.

  The wastewater treatment  plant ef-
fluent pH averaged 3.7,  but the waste-
water discharged to the sewage treat
 0 US GOVERNMENT PRINTING OFFICE: 1981-757-OU/7Z86

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    ment plant averaged 7 because of the
    effect of mixing the plant effluent with
    other wastewater streams from the beef
    packing plant. If the Alwatech waste-
    water treatment plant effluent had been
    raised to pH 7, this would have resulted
    in a needless increase of 10% in total
    costs.

    Recommendations
      Means of reducing the operating cost
    of the  Alwatech process should be
    investigated. While the pH should be
    near 2 for minimum  operating cost, the
    calcium lignosulfonate dose need not
    exceed  5% of the influent COD concen-
    tration.  The effect of doses less than 5%
    on COD removal, and especially protein
    recovery should be studied.
     The results of a detailed laboratory
    investigation of the use of chitosan are
    summarized. A similar study should be
    done for calcium lignosulfonate, be-
    cause of the potential for significant
    reduction in operating costs. In addition,
    it is virtually impossible  in a full scale
    operation (such as the one described in
    this report) to evaluate the effect of
    various plant operating practices on the
    sludge produced. Where protein recovery
    and hence financial recovery is possible,
    it is essential to know the effect of
    changes in operating variables on sludge
    production and characteristics.
      Ways to increase the  centrifuge ef-
    ficiency for total solids as well as protein
    need to be investigated. The low protein
    efficiency (66%) of the centrifuge pre-
    cludes separate treatment of the centri-
    fuge reject solution unless one is willing
    to accept a  34% loss of potentially
    recoverable protein.
      Before treatment by the  Alwatech
    process, it may  be  desirable to have
        heavy solids and readily floatable grease
        removed by  an efficient continuous
        screening system followed by a balanc-
        ing tank with a relatively short detention
        time (30 minutes) to even out rapid
        variations in flow and concentration.
        This might improve solids handling and
        sludge product quality.
          While additional investigation of this
        process has  been recommended, the
        process is ready to be used in its present
        state of development.
           John C. Ward was attending Colorado State University. Fort Collins. CO 80523;
             Walter Adams is with Sterling Colorado Bgbt.Company, Sterling, CO 80751;
             andH. Chr. Isaksen is Process Department Head of Alwatech, Oslo, Norway.  A
           Kenneth Dostal and Jack Witherow are the EPA Project Officers (see below).  \
           The complete report, entitled "Protein Recovery from Beef Packing Effluent,"
             (Order No. PB 81-224 362; Cost: $15.50, subject to change) will be available
             only from:
                  National Technical Information Service
                  5285 Port Royal Road
                  Springfield,  VA 22161
                  Telephone: 703-487-4650
           The EPA Project Officers can be contacted at:
                  Industrial Environmental Research Laboratory
                  U.S. Environmental Protection Agency
                  Cincinnati, OH 45268
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Postage and
Fees Paid
Environmental
Protection
Agency
EPA 335
Official Business
Penalty for Private Use $300

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