Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Two‐dimensional model of biofilm detachment caused by internal stress from liquid flow

Two‐dimensional model of biofilm detachment caused by internal stress from liquid flow A two‐dimensional model for biofilm growth and detachment was used to evaluate the effect of detachment on biofilm structures. The detachment process is considered to be due to internal stress created by moving liquid past the biofilm. This model generated a variety of realistic biofilm‐formation patterns. It was possible to model in a unified way two different biofilm detachment processes, erosion (small‐particle loss), and sloughing (large‐biomass‐particle removal). The distribution of the fraction from total biomass detached as a function of detached particle mass, gives indications about which of the two mechanisms is dominant. Model simulations indicate that erosion makes the biofilm surface smoother. Sloughing, in contrast, leads to an increased biofilm‐surface roughness. Faster growing biofilms have a faster detachment rate than slow‐growing biofilms, under similar hydrodynamic conditions and biofilm strength. This is in perfect accordance with the experimental evidence showing that detachment is dependent on both shear‐ and microbial‐growth rates. High growth rates trigger instability in biofilm accumulation and abrupt biomass loss (sloughing). Massive sloughing can be avoided by high liquid shear, combined with low biomass growth rates. As the modeling results show, the causes for sloughing must be sought not only in the biofilm strength, but also in its shape. Several “mushroom‐like” biofilm structures like those repeatedly reported in the literature occurred, due to a combined effect of nutrient depletion and breaking at the colony base. A rough carrier surface promotes biofilm development in hydrodynamic conditions in which the biofilm on a flat surface would not form. Although biofilm patches filled completely the cavity in which they started to grow, they were unable to spill over the carrier peaks and to fully colonize the substratum. © 2000 John Wiley & Sons, Inc. Biotechnol Bioeng 72: 205–218, 2001. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Biotechnology and Bioengineering Wiley

Two‐dimensional model of biofilm detachment caused by internal stress from liquid flow

Download PDF
14 pages

Loading next page...
 
/lp/wiley/two-dimensional-model-of-biofilm-detachment-caused-by-internal-stress-8FOMedrygC

References (0)

References for this paper are not available at this time. We will be adding them shortly, thank you for your patience.

Publisher
Wiley
Copyright
Copyright © 2001 John Wiley & Sons, Inc.
ISSN
0006-3592
eISSN
1097-0290
DOI
10.1002/1097-0290(20000120)72:2<205::AID-BIT9>3.3.CO;2-C
Publisher site
See Article on Publisher Site

Abstract

A two‐dimensional model for biofilm growth and detachment was used to evaluate the effect of detachment on biofilm structures. The detachment process is considered to be due to internal stress created by moving liquid past the biofilm. This model generated a variety of realistic biofilm‐formation patterns. It was possible to model in a unified way two different biofilm detachment processes, erosion (small‐particle loss), and sloughing (large‐biomass‐particle removal). The distribution of the fraction from total biomass detached as a function of detached particle mass, gives indications about which of the two mechanisms is dominant. Model simulations indicate that erosion makes the biofilm surface smoother. Sloughing, in contrast, leads to an increased biofilm‐surface roughness. Faster growing biofilms have a faster detachment rate than slow‐growing biofilms, under similar hydrodynamic conditions and biofilm strength. This is in perfect accordance with the experimental evidence showing that detachment is dependent on both shear‐ and microbial‐growth rates. High growth rates trigger instability in biofilm accumulation and abrupt biomass loss (sloughing). Massive sloughing can be avoided by high liquid shear, combined with low biomass growth rates. As the modeling results show, the causes for sloughing must be sought not only in the biofilm strength, but also in its shape. Several “mushroom‐like” biofilm structures like those repeatedly reported in the literature occurred, due to a combined effect of nutrient depletion and breaking at the colony base. A rough carrier surface promotes biofilm development in hydrodynamic conditions in which the biofilm on a flat surface would not form. Although biofilm patches filled completely the cavity in which they started to grow, they were unable to spill over the carrier peaks and to fully colonize the substratum. © 2000 John Wiley & Sons, Inc. Biotechnol Bioeng 72: 205–218, 2001.

Journal

Biotechnology and Bioengineering – Wiley

Published: Jan 20, 2001

Keywords: biofilm; mathematical model; detachment; erosion; sloughing; shear stress; flow; roughness

There are no references for this article.