16    CAPTOR DESIGN CONSIDERATIONS-CARBONACEOUS
BOD APPLICATIONS
Charles E. Tharp, Manager
Captor, Inc.
Columbia, Missouri 65201
Sanjoy Bhattacharya, Assistant Professor
Angela Safferman, Research Associate
Department of Civil and Environmental Engineering
University of Cincinnati
Cincinnati, Ohio 45221
HISTORY OF CAPTOR
Captor was conceived and designed to offer high rate biological treatment of carbonaceous wastewaters by use of reticulated foam bio-support media circulated and retained in the aeration basin.
This concept was developed in England, and considerable study has been conducted on effects of
addition of reticulated foam bio-support media into aeration basins.'
The basic concept of Captor is to increase the biological population of microorganisms available
for conversion or destruction of BOD using both fixed film and suspended growth organisms. With a
high biomass concentration trapped in the pads, it is possible to achieve greater BOD removals and/or
reduce the reaction time necessary to obtain those removals. In addition, it was postulated the Captor
process could handle wide variations in both hydraulic and organic loadings because of this stable
biomass population. A schematic of the basic captor process is shown in Figure 1.
Initial projections of Captor performance suggested the Captor process could be utilized for
biological treatment without the need for clarification. The secondary clarifier was to be eliminated by
allowing the Captor pad cleaner to function as the primary sludge wasting device for the entire
biological system.
Because of the significant opportunities and potential for the Captor process to upgrade existing
facilities and offer significant impact on waste treatment applications in general, a joint effort on the
part of the USEPA and the English WRC was made to study the Captor process. This pilot scale study
was carried out at the USEPA Test and Evaluation (T & E) facility in Cincinnati, Ohio to evaluate
Captor for carbonaceous BOD removal in high rate treatment systems. The study conducted by the
USEPA indicated Captor was capable of removing and/or converting considerable BOD; however,
actual performance of Captor was less than projected and was severely limited by mechanical and
operational features of equipment employed during this study. It became obvious that Captor
required additional development before an economical system could be effective commercially.
Waste   Sludge
O O
Retaining
Screen
Figure 1.    Schematic of basic Captor process.
44th Purdue Industrial Waste Conference Proceedings, © 1990 Lewis Publishers. Inc., Chelsea, Michigan 48118.
Printed in U.S.A.
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