TY - JOUR
T1 - Layered viscoelastic properties of granular biofilms
AU - Liou, Hong Cin
AU - Sabba, Fabrizio
AU - Wang, Ziwei
AU - Wells, George
AU - Balogun, Oluwaseyi
N1 - Funding Information:
We thank Aqua-Aerobic Systems, Inc. (Rockford, IL, USA) for providing granular biofilms for this work. The authors also acknowledge the National Science Foundation's support via Awards CBET-1701105 and CBET-1937290, and the seed funding from the Civil and Environmental Engineering Department at Northwestern University provided for this project.
Funding Information:
We thank Aqua-Aerobic Systems, Inc. (Rockford, IL, USA) for providing granular biofilms for this work. The authors also acknowledge the National Science Foundation's support via Awards CBET-1701105 and CBET-1937290, and the seed funding from the Civil and Environmental Engineering Department at Northwestern University provided for this project.
Publisher Copyright:
© 2021
PY - 2021/9/1
Y1 - 2021/9/1
N2 - Granular biofilms are dense spherical complex biological systems composed mainly of multi-microbial cells, water, and extracellular polymeric substances (EPS). They facilitate efficient purification and settling of activated sludge in wastewater treatment processes. The viscoelastic properties of these complex biofilm systems are important characteristics that control their growth and dictate how they respond to hydrodynamic forces and chemical stimuli. However, the viscoelastic properties of granular biofilms are poorly understood. In this paper, we study granular biofilms' viscoelastic properties using optical coherence elastography (OCE), a nondestructive method that integrates optical coherence tomography (OCT) with elastic wave propagation. While quantitative viscoelastic characterization of granular biofilms is challenging due to their heterogeneous properties, we show that elastic waves are suitable for this purpose. First, we employ guided elastic waves in a thin section of a granular biofilm to reveal a two-layered profile for the viscoelastic properties. Next, we utilize circumferential elastic waves that propagate near the surface of a non-sectioned spherical biofilm to quantify the layered system's viscoelastic properties. To the best of our knowledge, this work is the first quantitative study that characterizes the layered viscoelastic properties of granular biofilms. The measurement approach may provide a platform to study the interplay between the viscoelastic properties and other characteristics of granular biofilms such as the complex microbial system, morphology, and oxygen distribution.
AB - Granular biofilms are dense spherical complex biological systems composed mainly of multi-microbial cells, water, and extracellular polymeric substances (EPS). They facilitate efficient purification and settling of activated sludge in wastewater treatment processes. The viscoelastic properties of these complex biofilm systems are important characteristics that control their growth and dictate how they respond to hydrodynamic forces and chemical stimuli. However, the viscoelastic properties of granular biofilms are poorly understood. In this paper, we study granular biofilms' viscoelastic properties using optical coherence elastography (OCE), a nondestructive method that integrates optical coherence tomography (OCT) with elastic wave propagation. While quantitative viscoelastic characterization of granular biofilms is challenging due to their heterogeneous properties, we show that elastic waves are suitable for this purpose. First, we employ guided elastic waves in a thin section of a granular biofilm to reveal a two-layered profile for the viscoelastic properties. Next, we utilize circumferential elastic waves that propagate near the surface of a non-sectioned spherical biofilm to quantify the layered system's viscoelastic properties. To the best of our knowledge, this work is the first quantitative study that characterizes the layered viscoelastic properties of granular biofilms. The measurement approach may provide a platform to study the interplay between the viscoelastic properties and other characteristics of granular biofilms such as the complex microbial system, morphology, and oxygen distribution.
KW - Granular biofilms
KW - Mechanics of granular biofilms
KW - Nondestructive viscoelastic characterization
KW - Optical coherence elastography
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U2 - 10.1016/j.watres.2021.117394
DO - 10.1016/j.watres.2021.117394
M3 - Article
C2 - 34256191
AN - SCOPUS:85109597347
SN - 0043-1354
VL - 202
JO - Water Research
JF - Water Research
M1 - 117394
ER -