Title: Performance comparison between a two-reactor cascade and a single tank in an activated sludge wastewater treatment process

Authors: H.S. Sidhu, S.D. Watt, M.I. Nelson

Addresses: School of Physical, Environmental and Mathematical Sciences, University of New South Wales at the Australian Defence Force Academy, Canberra, ACT 2600, Australia. ' School of Physical, Environmental and Mathematical Sciences, University of New South Wales at the Australian Defence Force Academy, Canberra, ACT 2600, Australia. ' School of Mathematics and Applied Statistics, The University of Wollongong, Wollongong, NSW 2522, Australia

Abstract: We investigate a model for the treatment of wastewater in the activated sludge process. The process is based on the aeration of wastewater with flocculating biological growth, followed by the separation of treated wastewater from biological growth. The biochemical model consists of two types of bacteria: sludge bacteria and sewage bacteria; and two types of ciliated protozoa: free-swimming ciliates and ciliates attached to sludge flocs. A combination of steady-state analysis, path following techniques and numerical integration of the governing equations are used to compare the performance for a single tank system with that of a two-reactor cascade.

Keywords: wastewater treatment; activated sludge; bifurcation; nonlinear dynamics; treatment efficiency; reaction engineering; stability; modelling; two-reactor cascade; single tank; aeration; sludge bacteria; sewage bacteria.

DOI: 10.1504/IJEWM.2009.026338

International Journal of Environment and Waste Management, 2009 Vol.3 No.3/4, pp.214 - 225

Published online: 07 Jun 2009 *

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