Development of Biological Treatment
Data for Chemical Wastes
DAVIS L. FORD, Assistant Director
EARNEST F. GLOYNA, Director
YEN-TAI YANG
Center for Research in Water Resources
University of Texas
Austin, Texas
INTRODUCTION
There are many complex problems involved when considering a waste treatment system for chemical wastewaters. Biological treatment of such wastes is usually the most economical means of reducing the toxicity, BOD, COD, and objectionable appearance of the wastewater. However, toxicity and non-biode-
gradability problems must be considered as variables in each waste stream. The
stabilization rate of organic compounds in waste streams by acclimated flora and
fauna will vary greatly. The mechanisms and kinetics of biological degradation
of chemical wastes are complex and usually difficult to predict empirically. A
thorough laboratory investigation of a specific chemical waste is therefore a necessary prerequisite leading to process design and construction.
A review of the literature indicates a multiplicity of laboratory approaches
which have been taken by investigators. Busch has placed particular emphasis on
laboratory process kinetics and oxidizability in the development of design criteria
(1, 2). Similar studies have been performed by Gloyna (3,4), and Eckenfelder (5,
6).
It is the author's intent to present the laboratory approach used in the development of basic design criteria of two dissimilar chemical wastes, using some of the
precepts mentioned in the literature and expanding the program to fit the wastewaters involved. Residual toxicity as affecting aquatic organisms is not considered herein.
WASTE CHARACTERIZATION AND ACCLIMATION
These chemical wastes were shipped to the University laboratories in 55 gal
drum containers from the respective industries by motor freight. Confirmatory
characterization analyses performed before and after shipment showed that there
were no significant cnanges in the quality of the waste during transport as a result
of air stripping or biological degradation. The wastewater was immediately
characterized according to COD, BOD, pH, chemical components, dissolved solids,
and suspended solids. Nitrogen and phosphorus analyses were included to determine if nutrient supplementation was required. Occasionally, infra-red energy
absorption patterns of the process wastewater can be performed and compared to a
similar pattern obtained at the industrial site in order to verify the contribution
from various process streams. In all cases extensive BOD and COD data were collected throughout the testing program. A typical BOD and COD relationship of
one waste stream is shown in Figure 1. This relationship infers that a portion of
the organics which were oxidizea by dicromate (those that exert a COD) were
either non-biodegradable or relatively resistant to biological degredation.   If the
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