An analysis of a standard reactor cascade and a step-feed reactor cascade for biological processes described by monod kinetics

Harvinder S. Sidhu, Mark Ian Nelson, Easwaran Balakrishnan

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

We analyse the steady-state operation of two types of reactor cascade without recycle. The first is a standard reactor cascade in which the feed stream enters into the first reactor. The second is a step-feed reactor cascade in which an equal proportion of the feed stream enters each reactor in the cascade. The reaction is assumed to be a biological process governed by Monod growth kinetics with a decay coefficient for the microorganisms. The steady-states of both models are found for an arbitrary number of reactors and their stability determined as a function of the residence time. We show that in a step-feed reactor cascade the substrate and biomass concentrations leaving the reactor of the cascade are identical to those leaving the first reactor of the cascade. We further show that this result is true for a general specific growth rate of the form μ (S,X). Thus for such processes the non-standard cascade offers no advantage over that of a single reactor. This is surprising because the use of a non-standard cascade has been proposed as a mechanism to improve the biological treatment of wastewater.

Original languageEnglish
Pages (from-to)27-37
Number of pages11
JournalChemical Product and Process Modeling
Volume10
Issue number1
DOIs
Publication statusPublished - Mar 1 2015

Fingerprint

Growth kinetics
Microorganisms
Reactor
Cascade
Biomass
Wastewater
Kinetics
Substrates
Standards
Waste Water
Residence Time
Proportion
Substrate
Decay

Keywords

  • modelling
  • multistage continuous culture
  • step-feed reactor

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Modelling and Simulation

Cite this

An analysis of a standard reactor cascade and a step-feed reactor cascade for biological processes described by monod kinetics. / Sidhu, Harvinder S.; Nelson, Mark Ian; Balakrishnan, Easwaran.

In: Chemical Product and Process Modeling, Vol. 10, No. 1, 01.03.2015, p. 27-37.

Research output: Contribution to journalArticle

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