Modeling Bacterial Competition in Activated Sludge using Non-linear Dynamics and Monod Kinetics


A mechanistic model for activated sludge sewage treatment was developed to predict exploitative competition of six aerobic heterotrophic bacterial species competing for three complementary growth limiting substrates using the noninteractive Monod equation. The central hypothesis of the model is that in a multispecies/substrate system the number of coexisting bacterial species, N, exceeds the number of limiting resources, K, available for them. The model was used to investigate the effect of bioreactor conditions on the diversity of bacterial species. Preliminary results of model simulations showed that for a certain range of solids retention times (2.28-5.66 days) the competition of six bacterial species for three growth limiting substrates produces oscillations within the structure of the bacterial community allowing for the sustained growth of more than three species on the three substrates.

Meeting Name

IASTED International Conference on Modelling and Simulation (2003: Feb. 24-26, Palm Springs, CA)


Civil, Architectural and Environmental Engineering


AISTED. Technical Committee on Modelling and Simulation; WMSF

Keywords and Phrases

Acetic acid; Bacteria; Bioreactors; Ecosystems; Mathematical models; Oscillations; Sewage sludge; Sewage treatment; Urea; Competitive exclusion principle; Monod kinetics; Resource-ration theory; Sewage bacteriology; Microorganisms

International Standard Book Number (ISBN)


Document Type

Article - Conference proceedings

Document Version


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© 2003 International Association of Science and Technology for Development (IASTED), All rights reserved.

Publication Date

26 Feb 2003

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