Waste Characterization Concepts:
Predicting Potential Damages and
Treatability of Waste Waters
G. N. MCDERMOTT, Sanitary Engineer Director
Robert A. Taft Sanitary Engineering Center
Bureau of State Services
Public Health Service
Department of Health, Education, and Welfare
Cincinnati 26, Ohio
The estimation of the potential damaging effects a waste water wUl have
on receiving-water quality for subsequent downstream use is the essentail
meaning of the term "waste characterization" as used here. This paper describes methods and equipment for waste characterization. The damaging
effects of a waste emission may be altered by natural purification in the
stream, such as biological degradation, or by standard water treatment processes prior to some water uses. Therefore, a comprehensive characterization
of a waste must include estimation of the persistence of damaging effects in
streams and through water treatment processes. Waste characterization can
also include in its concept considerations of the effectiveness of waste treatment methods, in terms of diminishing potential damaging effects on water
quality. Treatment of an industrial waste in mixture with domestic sewage
may be the form of treatment involved; in which case, consideration must
be given to possible interference with the sewage treatment process in removing the domestic sewage constituents or disposing of the sludge as well as
to the effectiveness of the process in diminishing the damaging effects of the
waste itself. In case disposal methods are used where some or a portion of the
wastes percolate through the soil to the ground water, the persistence of the
damaging effects in sub-surface flow may be included in characterization of
the wastes. These multiple facets of characterization are shown diagram-
matically in Figure 1.
Potential damages to water quality for particular water uses are listed in
Table I. This list reveals that the common parameters of water pollution
control, such as five-day BOD, COD, and suspended matter, are inadequate
to assess many potential damaging effects. For instance, the five-day BOD is
a measure of only one potential damaging effect, suppression of dissolved
oxygen. It is ture that the oxygen demand tests may be proportional to the
to the concentration of a damaging substance and, therefore, an indirect
measurement of the degree of potential damaging effects. However, for some
organic substances biological degradation may be so slow that the five-day
BOD test would not effectively measure it. Neither the COD test nor the five-
day BOD demonstrate the presence of some substances at damaging levels,
and the tests do not distinguish between substances important only as oxi-
dizable matter and substances exerting some other damaging effect.
Waste characterization may be carried out for a pure compound or for an
industrial waste containing a conglomeration of unknown and virtually unidentifiable constituents.    Thus,   it is useful to either of two types of water
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