Title
Controlling the hydraulic resistance of membrane biofilms by engineering biofilm physical structure
Author
Desmond, Peter (Rheinisch-Westfälische Technische Hochschule)
Huisman, Kees Theo (King Abdullah University of Science and Technology)
Sanawar, Huma (King Abdullah University of Science and Technology)
Farhat, Nadia M. (King Abdullah University of Science and Technology)
Traber, Jacqueline (Swiss Federal Institute of Aquatic Science and Technology)
Fridjonsson, Einar O. (University of Western Australia)
Johns, Michael L. (University of Western Australia)
Flemming, Hans Curt (Universität Duisburg-Essen; Singapore Centre for Environmental Life Sciences Engineering,; IWW Water Centre, Muelheim)
Picioreanu, C. (Water Desalination and Reuse Center; King Abdullah University of Science and Technology) 
Vrouwenvelder, J.S. (TU Delft BT/Environmental Biotechnology; King Abdullah University of Science and Technology)
Date
2022
Abstract
The application of membrane technology for water treatment and reuse is hampered by the development of a microbial biofilm. Biofilm growth in micro-and ultrafiltration (MF/UF) membrane modules, on both the membrane surface and feed spacer, can form a secondary membrane and exert resistance to permeation and crossflow, increasing energy demand and decreasing permeate quantity and quality. In recent years, exhaustive efforts were made to understand the chemical, structural and hydraulic characteristics of membrane biofilms. In this review, we critically assess which specific structural features of membrane biofilms exert resistance to forced water passage in MF/UF membranes systems applied to water and wastewater treatment, and how biofilm physical structure can be engineered by process operation to impose less hydraulic resistance (“below-the-pain threshold”). Counter-intuitively, biofilms with greater thickness do not always cause a higher hydraulic resistance than thinner biofilms. Dense biofilms, however, had consistently higher hydraulic resistances compared to less dense biofilms. The mechanism by which density exerts hydraulic resistance is reported in the literature to be dependant on the biofilms’ internal packing structure and EPS chemical composition (e.g., porosity, polymer concentration). Current reports of internal porosity in membrane biofilms are not supported by adequate experimental evidence or by a reliable methodology, limiting a unified understanding of biofilm internal structure. Identifying the dependency of hydraulic resistance on biofilm density invites efforts to control the hydraulic resistance of membrane biofilms by engineering internal biofilm structure. Regulation of biofilm internal structure is possible by alteration of key determinants such as feed water nutrient composition/concentration, hydraulic shear stress and resistance and can engineer biofilm structural development to decrease density and therein hydraulic resistance. Future efforts should seek to determine the extent to which the concept of “biofilm engineering” can be extended to other biofilm parameters such as mechanical stability and the implication for biofilm control/removal in engineered water systems (e.g., pipelines and/or, cooling towers) susceptible to biofouling.
Subject
Biofilm
Density
Hydraulic resistance
Membrane filtration
Physical structure
To reference this document use:
http://resolver.tudelft.nl/uuid:a0d2d875-9c16-4780-b97a-c023235bcd45
DOI
https://doi.org/10.1016/j.watres.2021.118031
Embargo date
2023-07-01
ISSN
0043-1354
Source
Water Research, 210
Bibliographical note
Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.
Part of collection
Institutional Repository
Document type
journal article
Rights
© 2022 Peter Desmond, Kees Theo Huisman, Huma Sanawar, Nadia M. Farhat, Jacqueline Traber, Einar O. Fridjonsson, Michael L. Johns, Hans Curt Flemming, C. Picioreanu, J.S. Vrouwenvelder