Group Title: Citrus Station mimeo report - Florida Citrus Experiment Station ; 55-4
Title: Use of excess activated sludge from the treatment of citrus processing waste water
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 Material Information
Title: Use of excess activated sludge from the treatment of citrus processing waste water
Series Title: Citrus Station mimeo report
Physical Description: 2 leaves : ; 28 cm.
Language: English
Creator: Dougherty, Marshall H
McNary, Robert R
Wolford, R. W
Citrus Experiment Station (Lake Alfred, Fla.)
Florida Citrus Commission
Publisher: Florida Citrus Experiment Station :
Florida Citrus Commission
Place of Publication: Lake Alfred FL
Publication Date: 1954
Subject: Citrus fruit industry -- By-products -- Florida   ( lcsh )
Citrus fruit industry -- Waste disposal -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
Statement of Responsibility: M.H. Dougherty, R.R. McNary and R.W. Wolford.
General Note: Caption title.
General Note: "October 12, 1954."
 Record Information
Bibliographic ID: UF00072367
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 74328552

Full Text

Citrus Station Mimeo Report 55-4
October 12, 1954

Use of Excess Activated Sludge From the Treatment of Citrus
Processing Waste Water

M. H. Dougherty, R. R. McNary and R. W. Wolford

Results of work carried out in this laboratory (1) show that very good treat-
ment of citrus waste water can be accomplished by the activated sludge process.
However, this method of treating wastes requires disposing of the excess sludge
produced by the treatment process.

It has been reported (2) that significant amounts of vitamin B2 have been
found in activated sludge from the treatment of municipal sewage, indicating that
sludge from citrus wastes might also prove to be a good source of this vitamin.
Accordingly two small samples of dried citrus sludge were analyzed microbiologi-
cally and found to contain 2.3 and 2.8 micrograms of vitamin B12 per gram of dry
sludge. To investigate further the possibility that this material might be used
as a supplement in chicken feed, a run was made for the sole purpose of making
enough activated sludge for a vitamin B12 assay by the chick feeding method.

The activated sludge produced in the laboratory over a four month period was
dried on a drum dryer. Twelve pounds of dried material were obtained and taken
to the Agricultural Experiment Station in Gainesville where it was assayed for
vitamin B12. This assay was carried out by Dr. J. C. Driggers, Associate Poultry
Husbandman. He found approximately two micrograms of vitamin B12 per gram of dry
material. This is considered only a moderate amount.

Since the vitamin B12 content was only moderately high it was decided to in-
vestigate the possibility that the sludge might contain members of the vitamin B
complex other than Blp. If this were so the sludge would have additional value
as a vitamin supplement in animal feeds. Chemical and microbiological analyses
were run on the dried activated citrus sludge for a number of B vitamins. The
results are given in the first column of Table 1.

The low value for vitamin B12, 1.5 micrograms per gram, is less than that
obtained by the same analytical procedure from two small samples analyzed previously,
viz., 2.3 and 2.8 micrograms per gram. This bears out the belief of the authors
that the vitamin B12 content of the sludge varied during the several months re-
quired to produce tle desired amount of dry material. There were noticeable
differences in the sludge appearance, settleability, etc. The conditions for
optimum production of the vitamin were not always in existence (if at all).
Therefore, by control of the activated sludge process to produce maximum vitamin
content in the sludge rather than maximum B.O.D. reduction in the waste, a
sludge better adapted to use in animal feeds could very probably be produced.
Storage of the sludge, even though refrigerated, until a sufficient quantity had
been accumulated to yield twelve pounds of dried material, may have caused some
vitamin loss also. This delay was unavoidable, however, because of conditions
beyond our control.

Florida Citrus Experiment Station and
Florida Citrus Commission, Lake Alfred, Fla.


Comparison of the published vitamin content of dried distillers solubles
and dried whey (Table 1) indicate that dried citrus sludge should have a value
in between these two materials when used as a supplemental source of B vitamins
in chicken feed. The dried distillers solubles now sells for 50 per pound and
dried whey for 7.5 per pound. The production and sale of the dried sludge should
therefore defray part of the cost of the waste treatment,

Literature Cited
1. Dougherty, M. H., McNary, R. R. and Wolford, R. W. Treatment of citrus pro-
cessing wastes by activated sludge. Proc. Fourth Annual Citrus Processors
Meeting, October 6, 1953, Lake Alfred, Florida.

2. Hoover, S. R., Jasewicz, L., Pepinsky, J. B. and Porges,
as a source of vitamin B12 for animal feeds. Sewage and
38-44 (1952).

N. Activated sludge
Ind. Wastes, 24,

Florida Citrus Experiment Station and
Florida Citrus Commission, Lake Alfred, Fla.


Comparison of the vitamin content of dried citrus sludge
with dried whey and dried distillers solubles

Micrograms per Gram
Dried citrus Dried whey

Dried distillers




















Protein 16% 9% 23%

Price/lb. $.05 $.075

Florida Citrus Experiment Station and
Florida Citrus Commission, Lake Alfred, Fla.

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