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A Modeling and Simulation Study of the Role of Suspended Microbial Populations in Nitrification in a Biofilm Reactor.

Masic, Alma LU and Eberl, Hermann J (2014) In Bulletin of Mathematical Biology 76(1). p.27-58
Abstract
Many biological wastewater treatment processes are based on bacterial biofilms, i.e. layered aggregates of microbial populations deposited on surfaces. Detachment and (re-)attachment leads to an exchange of biomass between the biofilm and the surrounding aqueous phase. Traditionally, mathematical models of biofilm processes do not take the contribution of the suspended, non-attached bacteria into account, implicitly assuming that these are negligible due to the relatively small amount of suspended biomass compared to biofilm biomass. In this paper, we present a model for a nitrifying biofilm reactor that explicitly includes both types of biomass. The model is derived by coupling a reactor mass balance for suspended populations and... (More)
Many biological wastewater treatment processes are based on bacterial biofilms, i.e. layered aggregates of microbial populations deposited on surfaces. Detachment and (re-)attachment leads to an exchange of biomass between the biofilm and the surrounding aqueous phase. Traditionally, mathematical models of biofilm processes do not take the contribution of the suspended, non-attached bacteria into account, implicitly assuming that these are negligible due to the relatively small amount of suspended biomass compared to biofilm biomass. In this paper, we present a model for a nitrifying biofilm reactor that explicitly includes both types of biomass. The model is derived by coupling a reactor mass balance for suspended populations and substrates with a full one-dimensional Wanner-Gujer type biofilm model. The complexity of this model, both with respect to mathematical structure and number of parameters, prevents a rigorous analysis of its dynamics, wherefore we study the model numerically.Our investigations show that suspended biomass needs to be considered explicitly in the model if the interests of the study are the details of the nitrification process and its intermediate steps and compounds. However, suspended biomass may be neglected if the primary interests are the overall reactor performance criteria, such as removal rates. Furthermore, it can be expected that changes in the biofilm area, attachment, detachment, and dilution rates are more likely to affect the variables primarily associated with the second step of nitrification, while the variables associated with the first step tend to be more robust. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Biofilm, Mathematical model, Nitrification, Suspended biomass
in
Bulletin of Mathematical Biology
volume
76
issue
1
pages
27 - 58
publisher
Springer
external identifiers
  • wos:000329629000002
  • pmid:24307083
  • scopus:84902846285
ISSN
1522-9602
DOI
10.1007/s11538-013-9898-2
language
English
LU publication?
yes
id
b4863bd6-44fe-4bca-9035-f51f8e267fa0 (old id 4225235)
date added to LUP
2014-01-23 15:04:52
date last changed
2017-08-20 03:12:07
@article{b4863bd6-44fe-4bca-9035-f51f8e267fa0,
  abstract     = {Many biological wastewater treatment processes are based on bacterial biofilms, i.e. layered aggregates of microbial populations deposited on surfaces. Detachment and (re-)attachment leads to an exchange of biomass between the biofilm and the surrounding aqueous phase. Traditionally, mathematical models of biofilm processes do not take the contribution of the suspended, non-attached bacteria into account, implicitly assuming that these are negligible due to the relatively small amount of suspended biomass compared to biofilm biomass. In this paper, we present a model for a nitrifying biofilm reactor that explicitly includes both types of biomass. The model is derived by coupling a reactor mass balance for suspended populations and substrates with a full one-dimensional Wanner-Gujer type biofilm model. The complexity of this model, both with respect to mathematical structure and number of parameters, prevents a rigorous analysis of its dynamics, wherefore we study the model numerically.Our investigations show that suspended biomass needs to be considered explicitly in the model if the interests of the study are the details of the nitrification process and its intermediate steps and compounds. However, suspended biomass may be neglected if the primary interests are the overall reactor performance criteria, such as removal rates. Furthermore, it can be expected that changes in the biofilm area, attachment, detachment, and dilution rates are more likely to affect the variables primarily associated with the second step of nitrification, while the variables associated with the first step tend to be more robust.},
  author       = {Masic, Alma and Eberl, Hermann J},
  issn         = {1522-9602},
  keyword      = {Biofilm,Mathematical model,Nitrification,Suspended biomass},
  language     = {eng},
  number       = {1},
  pages        = {27--58},
  publisher    = {Springer},
  series       = {Bulletin of Mathematical Biology},
  title        = {A Modeling and Simulation Study of the Role of Suspended Microbial Populations in Nitrification in a Biofilm Reactor.},
  url          = {http://dx.doi.org/10.1007/s11538-013-9898-2},
  volume       = {76},
  year         = {2014},
}