Title page for ETD etd-09192006-213930

Type of Document Master's Thesis
Author Easwaran, Sathya Poornima
Author's Email Address speaswar@vt.edu
URN etd-09192006-213930
Title Developing a Mechanistic Understanding and Optimization of the Cannibal Process: Phase II
Degree Master of Science
Department Environmental Engineering
Advisory Committee
Advisor Name Title
Novak, John T. Committee Chair
Boardman, Gregory D. Committee Member
Randall, Clifford W. Committee Member
  • Anaerobic Bioreactor
  • Activated sludge
  • Solids Destruction
  • Solids Retention Time (SRT)
  • Interchange Rate
  • Hydraulic Retention Time (HRT)
Date of Defense 2006-08-29
Availability unrestricted
The Cannibal system, comprised of an activated sludge process integrated with a side stream anaerobic bioreactor, is capable of reducing excess sludge up to 60% compared to the conventional activated sludge process. The hydraulic retention time (HRT) in the Cannibal bioreactor and the interchange rate (the percent of sludge by mass interchanged between the activated sludge system and the bioreactor on daily basis) are the two important operational parameters in the optimization of the Cannibal process. This research was designed to investigate the effect of the Cannibal bioreactor hydraulic retention time and the interchange rate on the solids destruction in the system. The first phase of this study has looked at the effect of three different HRTs, 5 day, 7 day and 10 day. The interchange rate during phase I was 10%. The results showed that the 7 day HRT can be recommended as the minimum retention period for the Cannibal process. The 5 day HRT Cannibal system had some settling problems and high volatile fatty acid content compared to the 7 day HRT Cannibal system. The protein and polysaccharide tests showed that the Cannibal bioreactor is primarily involved in the release of biopolymers which are degraded in the aerobic environment.

The second part of this study focused on the effect of the interchange rate (IR) on the solids destruction in the system. The interchange rates that were applied in the system were 15%, 10%, 7%, 5% and 4%.The HRT in the Cannibal bioreactor was 7 day. The results showed that the 10% interchange rate gave maximum solids destruction than the other interchange rates. This implies that 10% is an optimum IR for the Cannibal system. Apart from higher solids wastage, the 4% and 5% IR Cannibal systems had higher volatile fatty acid production.

  Filename       Size       Approximate Download Time (Hours:Minutes:Seconds) 
 28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access 
  SathyaEaswaranThesis.pdf 543.64 Kb 00:02:31 00:01:17 00:01:07 00:00:33 00:00:02

Browse All Available ETDs by ( Author | Department )

dla home
etds imagebase journals news ereserve special collections
virgnia tech home contact dla university libraries

If you have questions or technical problems, please Contact DLA.