Factors Responsible for
Non-Biodegradability of Industrial Wastes
ROBERT L. IRVINE, JR., Assistant Professor
Environmental Engineering Division
Texas A & M University
College Station, Texas
A. W. BUSCH, Professor
Environmental   Science   and   Engineering
Rice University
Houston, Texas
INTRODUCTION
The phase of Environmental Engineering dealing with process design of biological waste treatment facilities requires an input from many disciplines. Three
which immediately come to mind are Chemistry, Biology, and Chemical Engineering.
To expect one individual to be well versed in each of these disciplines would be
unreasonable if not impossible. Thus communication with "experts" in each of these
areas is imperative. With knowledge gained from these "experts," answers to many
puzzling questions will be found and sophisticated design techniques can be implemented. This paper will demonstrate how feedback from biochemistry can allow introduction of innovative concepts which may lead the way to a new era of biological
waste treatment. The goal is not to be dramatic but to emphasize the importance of
basic research being performed in related areas of study.
BACKGROUND
The fundamental goal of most waste treatment processes is the transformation
of dilute soluble or colloidal materials into a more concentrated insoluble mass. This
is accomplished in biological waste treatment by the biochemical conversion of an
organic waste to cell mass and other products of metabolism.
The biological process has been housed in both completely mixed and plug flow
reactors. The efficiency of the process depends upon the design and operation of the
treatment unit. For many years, this design was an art rather than a science. The
emphasis was on the entering BOD and the detention time of the total flow rather
than on the characteristic growth rate of the organisms for a specific system. The
standard design procedures implicitly defined a rate most characteristic of that for
domestic wastes. Consequently, when the rate of reaction for an industrial waste
differed from the rate assumed, poor performance resulted.
Recently, Busch (1) developed a theoretically rational method for the determination of the rate of reaction in a biological system. Activated sludge units, designed
on this principle, removed a high percentage of the easily biodegradable materials.
- 903 -