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

Journal Article


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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.

Authors


  •   Sidhu, Harvinder S. (external author)
  •   Nelson, Mark I.
  •   Balakrishnan, Easwaran (external author)

Publication Date


  • 2015

Citation


  • Sidhu, H. S., Nelson, M. I. & Balakrishnan, E. (2015). An analysis of a standard reactor cascade and a step-feed reactor cascade for biological processes described by monod kinetics. Chemical Product and Process Modeling, 10 (1), 27-37.

Scopus Eid


  • 2-s2.0-84924857086

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=6020&context=eispapers

Ro Metadata Url


  • http://ro.uow.edu.au/eispapers/4993

Number Of Pages


  • 10

Start Page


  • 27

End Page


  • 37

Volume


  • 10

Issue


  • 1

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.

Authors


  •   Sidhu, Harvinder S. (external author)
  •   Nelson, Mark I.
  •   Balakrishnan, Easwaran (external author)

Publication Date


  • 2015

Citation


  • Sidhu, H. S., Nelson, M. I. & Balakrishnan, E. (2015). An analysis of a standard reactor cascade and a step-feed reactor cascade for biological processes described by monod kinetics. Chemical Product and Process Modeling, 10 (1), 27-37.

Scopus Eid


  • 2-s2.0-84924857086

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=6020&context=eispapers

Ro Metadata Url


  • http://ro.uow.edu.au/eispapers/4993

Number Of Pages


  • 10

Start Page


  • 27

End Page


  • 37

Volume


  • 10

Issue


  • 1