Section Ten
BACTERIAL SUPPLEMENTATION
29    CONSTRAINTS OF BIOAUGMENTATION IN ENHANCING
BIOLOGICAL TREATMENT PROCESS PERFORMANCE
Clifford R. Lange, Graduate Student
James R. Hartman, Graduate Student
Nyuk-Min Chong, Graduate Student
A. Scott Weber, Assistant Professor
Mark R. Matsumoto, Assistant Professor
Department of Civil Engineering
State University of New York at Buffalo
Buffalo, New York 14260
INTRODUCTION
In an operating bioreactor used for waste treatment, an indigenous bacterial population arises
which is unique from the standpoint of species diversity. This population is the result of physiological
and genetic adaptation to the waste characteristics and process operation parameters. In bioreactors
treating a variable mixture of toxic or inhibitory wastes, bacterial diversity is reduced by the increased
selective pressure on the population due to the presence of selected waste components. Reducing the
types of bacteria present, can diminish the genetic pool of the reactor population, and decrease the
ability of the population to respond to changes in the environment and/or waste composition.
Because of the diminished capacity for adaptation, biological hazardous waste treatment processes
are often plagued by upsets and are unable to degrade new compounds entering the waste stream.
Bioaugmentation is the process of adding non-indigenous bacterial supplements to a bioreactor for
the purpose of artificially increasing the bacterial diversity and/or activity of the reactor population.
Bioaugmentation may increase the biological diversity and activity of the population by: 1) adding
bacteria with enzymatic systems which allow degradation of previously non-biodegradable organics;
or 2) adding bacteria which have higher metabolic rates. Many bacterial supplements are available
commercially to augment existing populations of biological hazardous waste treatment processes.
To date, no clear consensus has been reached on the relative merits of bioaugmentation. The
purpose of this paper is to discuss and illustrate, with data from experimental studies, some of the
constraints of bioaugmentation in improving biological treatment performance.
BACKGROUND
Numerous presentations, reports, and articles have been delivered and published on the subject of
bioaugmentation. The reported advantages of bioaugmentation are mixed. The merits of bioaugmentation have been promoted most heavily in trade literature and conference proceedings. Relatively few
articles on bioaugmentation have been published in refereed journals. Generally, those that have been
published in the refereed literature, are not supportive of the bioaugmentation concept.
A compilation of findings from published papers on bioaugmentation are presented in Table I. For
each paper referenced, the location of the testing, waste type, whether or not treatment performance
was enhanced by bioaugmentation, and reference are given. Based on the information presented in
Table I, enhanced biological treatment performance has been attributed to bioaugmentation for those
studies conducted under field conditions, while those studies conducted in the laboratory have been
generally negative.
In summary, published results from recent research dealing with the effectiveness of bacterial
supplementation have been inconclusive. However, on the basis of a literature review, a number of
criteria which may impact on the potential success of bioaugmentation were identified. These criteria
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