Biofilm detachment mechanisms in a liquid-fluidized bed

H. T. Chang, Bruce Rittmann, D. Amar, R. Heim, O. Ehlinger, Y. Lesty

Research output: Contribution to journalArticle

138 Citations (Scopus)

Abstract

Bed fluidization offers the possibility of gaining the advantages of fixed-film biological processes without the disadvantage of pore clogging. However, the biofilm detachment rate, due to hydrodynamics and particle-to-particle attrition, is very poorly understood for fluidized-bed biofilm processes. In this work, a two-phase fluidized-bed biofilm was operated under a constant surface loading (0.99 mg total organic carbon/cm2 day) and with a range of bed height (H), fluid velocities (U), and support-particle concentrations (C(p)). Direct measurements were made for the specific biofilm loss rate coefficient (b(s)) and the total biofilm accumulation (X(f)L (f)). A hydrodynamic model allowed independent determination of the biofilm density (X(f)), biofilm thickness (L(f)), liquid shear stress (τ), and Reynolds number (Re). Multiple regression analysis of the results showed that increased particle-to-particle attrition, proportional to C(p), and increased turbulence, described by Pe, caused the biofilms to be denser and thinner. The specific detachment rate coefficient (b(s)) increased as C(p) and Re increased. Almost all of the b(s) values were larger than predicted by a previous model derived for smooth biofilms on a nonfluidized surface. Therefore, the turbulence and attrition of bed fluidization appear to be dominant detachment mechanisms.

Original languageEnglish (US)
Pages (from-to)499-506
Number of pages8
JournalBiotechnology and Bioengineering
Volume38
Issue number5
StatePublished - 1991
Externally publishedYes

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Biofilms
Fluidized beds
Liquids
Fluidization
Hydrodynamics
Turbulence
Biological Phenomena
Organic carbon
Regression analysis
Shear stress
Reynolds number
Carbon
Regression Analysis
Fluids

ASJC Scopus subject areas

  • Biotechnology
  • Microbiology

Cite this

Chang, H. T., Rittmann, B., Amar, D., Heim, R., Ehlinger, O., & Lesty, Y. (1991). Biofilm detachment mechanisms in a liquid-fluidized bed. Biotechnology and Bioengineering, 38(5), 499-506.

Biofilm detachment mechanisms in a liquid-fluidized bed. / Chang, H. T.; Rittmann, Bruce; Amar, D.; Heim, R.; Ehlinger, O.; Lesty, Y.

In: Biotechnology and Bioengineering, Vol. 38, No. 5, 1991, p. 499-506.

Research output: Contribution to journalArticle

Chang, HT, Rittmann, B, Amar, D, Heim, R, Ehlinger, O & Lesty, Y 1991, 'Biofilm detachment mechanisms in a liquid-fluidized bed', Biotechnology and Bioengineering, vol. 38, no. 5, pp. 499-506.
Chang HT, Rittmann B, Amar D, Heim R, Ehlinger O, Lesty Y. Biofilm detachment mechanisms in a liquid-fluidized bed. Biotechnology and Bioengineering. 1991;38(5):499-506.
Chang, H. T. ; Rittmann, Bruce ; Amar, D. ; Heim, R. ; Ehlinger, O. ; Lesty, Y. / Biofilm detachment mechanisms in a liquid-fluidized bed. In: Biotechnology and Bioengineering. 1991 ; Vol. 38, No. 5. pp. 499-506.
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