Oxidation of Radioactive Glucose
by Aerated Sludge
Nandor Porges, Aaron E. Wasserman, William J. Hopkins
and Lenore Jasewicz
Eastern Regional Research Laboratory
Eastern Utilization Research and Development Division
Agricultural Research Service
U. S. Department of Agriculture
Philadelphia, Pa.
Treatment of organic waste by aerated sludge depends upon the
metabolic activities of many microorganisms present in the mixed liquor.
Although aerated sludge is a melange of many types of microorganisms (7) in which all possible pathways of carbohydrate metabolism
could occur to complicate the picture, studies on the biochemical oxidation of dairy wastes (9) show that complete oxidation of milk sugar
involves distinct activities, such as removal of soluble material from
solution, intracellular storage, oxidative conversion of stored material,
and endogenous "respiration of cellular components.
Intensive studies in recent years show that carbohydrate dissimilation
by bacteria is a complex procedure and may involve more than one
metabolic pathway, yet this information has not been applied to the
degradation of organic wastes by sludge organisms. Investigations were
started to follow initially gross distribution of a substrate utilized by
sludge organisms. Radioactive glucose, labeled at the carbon-1 (C-l)
or carbon-6 (C-6) atoms, was used to follow the fate of the glucose
molecule with respect to CO2 evolution and sludge formation.
The authors are unaware of reports on studies of this nature in the
fields of sanitation and industrial wastes. Radioactive tracers have been
used in measuring sewage flow times and in procuring other operational
data. Rorschack and Reid (11) designed a laboratory scale pilot-plant
to study the effect of radiophosphorus on biological sewage oxidation.
In 1951 Grune and Eliassen (4) investigated effects of p32 on microbial
life to establish tolerance levels for amounts of radioactivity to be allowed
in sewers and sewage treatment plants. Skrinde and Sawyer (12) applied
Warburg techniques to the safe and economical determination of radio-
phosphorus effects on the BOD of domestic sewage. One C14 study
applicable to this investigation has been mentioned in a recent note.
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