Using the Kinetics of Biological Flocculation and the Limiting Flux Theory for the Preliminary Design of Activated Sludge Systems. I: Model Development
This article is a reply.
VIEW THE ORIGINAL ARTICLEThis article has a reply.
VIEW THE REPLYPublication: Journal of Environmental Engineering
Volume 133, Issue 1
Abstract
Current activated sludge models consider that the removal of biodegradable organics by suspended growth includes rapid enmeshment of the organic particles in the microbial floc, hydrolysis of the complex organic molecules into readily biodegradable organic substances, and oxidation of dissolved organic substances. All of the models assume hydrolysis is the rate-limiting step, but none consider the role that the kinetics of biological flocculation and the sludge settling characteristics may play in defining the activated sludge operating parameters. Several researchers have studied the kinetic of biological flocculation, and have analyzed its role on the removal of particulate COD in suspended growth reactors. It has been demonstrated that a large proportion of the organic matter present in sewage can be removed by biological flocculation using short hydraulic retention times and subsequent settling. This paper demonstrates that the one-dimensional limiting flux theory may be useful for coupling the sludge settling properties with the aeration tank behavior, and is a reasonable first approximation that can be used for activated sludge system design and operation.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The research reported herein was funded by the University of New Orleans Schlieder Urban Environmental Systems Center through an EPA grant and by the Jefferson Parish Department of Sewerage. The contribution of the research team members, Jackeline Luque and Eudomar Silva, is greatly appreciated.
References
APHA, AWWA, and WEF. (1998). Standard methods for the examination of waste and wastewater, 20th Ed., American Public Health Association, Baltimore.
Boltz, J. P., and La Motta, E. J. (2006). “The kinetics of particulate organic matter removal as a response to bioflocculation in aerobic biofilm reactors.” Environ. Eng. Sci., 32(5), 506–513.
Ekama, G. A., Barnard, J. L., Gunthert, F. W., Krebs, P., McCorquodale, J. A., Parker, D. S., and Wahlberg, E. J. (1997). Secondary settling tanks: Theory, modeling, design and operation,” International Association on Water Quality, London.
Ekama, G. A., and Marais, P. (2002). “Hydrodynamic modeling of secondary settling tanks,” WRC Rep. No. 835/1/02 Part 1. Water Resources Group, Dept. of Civil Engineering, Univ. of Cape Town, Cape Town, South Africa.
Griborio, A. (2004), “Secondary clarifier modeling: A multi-process approach.” Ph.D. dissertation, Univ. of New Orleans, New Orleans.
Gujer, W., Henze, M., Mino, T., and van Loosdrecht, M. (1999). “Activated sludge model No. 3.” Water Sci. Technol., 29(1), 183–193.
Henze, M., Gujer, W., Mino, T., and Loosdrecht, M. V. (2000). “The activated sludge models ASM1, ASM2, ASM2D and ASM3.” IWA Scientific and Technical Rep.
Jiménez, J. A. (2002). “Kinetics of COD removal in the activated sludge process, including bioflocculation.” Ph.D. dissertation, Univ. of New Orleans, New Orleans.
Jiménez, J. A., La Motta, E. J., and Parker, D. S., (2005). “Kinetics of removal of particulate chemical oxygen demand in the activated sludge process.” Water Environ. Res., 77(5), 437–446.
La Motta, E. J., Jiménez, J. A., Josse, J. A., and Manrique, A. (2004). “Role of bioflocculation on COD removal in the solids contact chamber of TF/SC process.” J. Environ. Eng., 130(7), 726–735.
Logan, B., and Hunt, J. (1988). “Bioflocculation as a microbial response to substrate limitations.” Biotechnol. Bioeng., 31(2), 91–101.
Luque, J. (2005). “Exocellular polymeric substances, bioflocculation, and sludge settling properties in a combined anaerobic/activated sludge process.” Ph.D. dissertation proposal, Univ. of New Orleans, New Orleans.
Mamais, D., Jenkins, D., and Pitt, P. (1993). “A rapid physical chemical method for the determination of readily biodegradable soluble COD in municipal wastewaters.” Water Res., 27(1), 195–197.
McCorquodale, J. A., La Motta, E. J., Griborio, A., Homes, J., and Georgiou, I. (2004). “Development of software for modeling activated sludge clarifier systems.” Technology Transfer Rep., submitted to U.S. Environmental Protection Agency, Dept. of Civil and Environmental Engineering, Univ. of New Orleans, New Orleans.
Metcalf, and Eddy, Inc. (2003). Wastewater engineering, treatment and reuse, 4th Ed., McGraw Hill, New York.
Morgenroth, E., Kommedal, R., and Harremoes, P. (2002). “Processes and modeling of hydrolysis of particulate organic matter in aerobic wastewater treatment—A review.” Water Sci. Technol., 45, 25–40.
Okutman, D., Ovez, S., and Orhon, D. (2001). “Hydrolysis of settleable substrate in domestic sewage.” Biotechnol. Lett., 23, 1907–1914.
Parker, D. S., Kaufman, W. J., and Jenkins, D. (1970). “Characteristics of biological flocs in turbulent regime.” SERL Rep. No. 70-5, Univ. of California, Berkeley, Calif.
Rojas, J. A. (2004). “Relationship between the sludge settling characteristics and the parameters of the activated sludge system.” Master’s thesis, Univ. of New Orleans, New Orleans.
Takacs, I., Patry, G. G., and Nolasco, D. (1991). “A dynamic model of the clarification-thickening process.” Water Res., 25(10), 1263–1271.
Vesilind, P. A. (1968). “Discussion of “Evaluation of activated sludge thickening theories,” by R. I. Dick and B. B. Ewin, J. Sanit. Engrg. Div., 94(AS1), 185–190.
Vitasovic, Z., Zhou, S. P., McCorquodale, J. A., and Lingren, K. (1997). “Secondary clarifier analysis using data from the clarifier research technical committee protocol.” Water Environ. Res., 69(5), 999–1007.
von Sperling, M. (1998). “A new method for the design of sequencing batch reactors (SBR) using the concept of the hindered settling velocity of the sludge.” Environ. Technol., 19, 1223–1231.
Wahlberg, E., Keinath, T., and Parker, D. (1994). “Influence of activated sludge flocculation time on secondary clarification.” Water Environ. Res., 66(6), 779–786.
Information & Authors
Information
Published In
Copyright
© 2007 ASCE.
History
Received: Mar 3, 2005
Accepted: May 15, 2006
Published online: Jan 1, 2007
Published in print: Jan 2007
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.