Skip to Main content Skip to Navigation
Journal articles

Effect of shear stress and growth conditions on detachment and physical properties of biofilms

Abstract : Detachment is one of the major processes determining the physical structure and microbial functionalities of biofilms. To predict detachment, it is necessary to take the mechanical properties of the biofilm and the effect of both hydrodynamic and growth conditions into account. In this work, experiments were conducted with biofilms developed under various shear stresses and with various substrate natures. In addition, two cases were considered in order to differentiate between the effect of hydrodynamic factors and growth factors: the biofilms were directly grown under the targeted shear stress (tau) condition or they were precultivated under very low shear stress (0.01 Pa) and then exposed to high shear stress in the range of 0.1-13 Pa. An exponential and asymptotic decrease of the biofilm thickness and mass with increasing tau was observed in both cases. On contrary density, expressed as the biofilm dry mass on a known substratum divided by the average thickness increased with tau. Denitrifying biofilms always showed greater thickness and density than oxic biofilms. These results showed the presence of a compact basal layer that resisted shear stresses as high as 13 Pa whatever the culture conditions. Above this basal layer, the cohesion was lower and depended on the shear stress applied during biofilm development. The application of shear stress to the biofilms resulted in both detachment and compression, but detachment prevailed for the upper part of the biofilms and compression prevailed for the basal layers. A model of biofilm structure underlying the stratified character of this aggregate is given in terms of density and cohesion. (C) 2012 Elsevier Ltd. All rights reserved.
Document type :
Journal articles
Complete list of metadata
Contributor : Archive Ouverte Prodinra Connect in order to contact the contributor
Submitted on : Thursday, February 4, 2016 - 10:27:25 PM
Last modification on : Tuesday, October 19, 2021 - 11:17:38 PM




Etienne Paul, Juan Carlos Ochoa Chavez, Yoan Pechaud, Yu Liu, Alain Liné. Effect of shear stress and growth conditions on detachment and physical properties of biofilms. Water Research, IWA Publishing, 2012, 46 (17), pp.5499 - 5508. ⟨10.1016/j.watres.2012.07.029⟩. ⟨hal-01268274⟩



Record views