Evaluating Treatability of Selected
Industrial Wastes
WILLIAM L. JORDEN, Project Engineer
Williams, Sweitzer and Barnum, Inc.
Atlanta, Georgia
FREDERICK G. POHLAND, Associate Professor
Georgia Institute of Technology
Atlanta, Georgia
BILLY H. KORNEGAY, Assistant Professor
Georgia Institute of Technology
Atlanta, Georgia
INTRODUCTION
Evaluating the treatability of an industrial wastewater involves more than
determining if the waste can be degraded biologically; a treatability study should
produce design information. In this discussion, a procedure is developed for
evaluating treatability with a continuous flow, bench scale, completely mixed, slurry
reactor. The results for three industrial wastes will also be presented to illustrate the
qualitative and quantitative information that can be obtained from the treatability
test proposed.
Conventional wastewater treatment plants use aerobic biological processes for
secondary treatment. In such secondary treatment processes, waste organics are
converted to biomass and other end products of biological respiration and
metabolism.
Aerobic secondary treatment is usually accomplished by means of activated
sludge tanks, trickling filters, aerated lagoons, and oxidation ponds. The design of
these units is generally based on "rule-of-thumb" relationships that have been
obtained from experience with successfully operated units. Municipal and military
treatment facilities have provided the bulk of this information. Therefore, these
"rule-of-thumb" design values are naturally biased toward design for domestic
wastewater treatment plants.
The design engineer must guard against indiscriminate use of this cookbook
approach in dealing with a wastewater that has characteristics different from
domestic sewage. Many industrial wastes fall in this category, and many seemingly
well designed industrial treatment facilities do not provide the anticipated removal
after construction.
Much work is currently being done in Sanitary Engineering to provide a more
rational approach to the design of secondary treatment facilities. Treatability tests
are coming into vogue; and, if conducted and evaluated properly, they can provide
invaluable design information (1, 2, 3, 4). By performing a treatability test, the
514