title: Biofouling in forward osmosis systems: An experimental and numerical study.
abstract: This study evaluates with numerical simulations supported by experimental data the impact of biofouling on membrane performance in a cross-flow forward osmosis (FO) system. The two-dimensional numerical model couples liquid flow with solute transport in the FO feed and draw channels, in the FO membrane support layer and in the biofilm developed on one or both sides of the membrane. The developed model was tested against experimental measurements at various osmotic pressure differences and in batch operation without and with the presence of biofilm on the membrane active layer. Numerical studies explored the effect of biofilm properties (thickness, hydraulic permeability and porosity), biofilm membrane surface coverage, and biofilm location on salt external concentration polarization and on the permeation flux. The numerical simulations revealed that (i) when biofouling occurs, external concentration polarization became important, (ii) the biofilm hydraulic permeability and membrane surface coverage have the highest impact on water flux, and (iii) the biofilm formed in the draw channel impacts the process performance more than when formed in the feed channel. The proposed mathematical model helps to understand the impact of biofouling in FO membrane systems and to develop possible strategies to reduce and control biofouling.
authors.affiliation: King Abdullah University of Science and Technology (KAUST), Water Desalination and Reuse Center (WDRC), Division of Biological and Environmental Science and Engineering (BESE), Thuwal 23955-6900, Saudi Arabia. Electronic address: Szilard.Bucs@kaust.edu.sa.
authors.forename: Szilárd S
authors.initials: SS
authors.lastname: Bucs
authors.affiliation: King Abdullah University of Science and Technology (KAUST), Water Desalination and Reuse Center (WDRC), Division of Biological and Environmental Science and Engineering (BESE), Thuwal 23955-6900, Saudi Arabia. Electronic address: Rodrigo.Valladares@kaust.edu.sa.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Valladares Linares
authors.affiliation: King Abdullah University of Science and Technology (KAUST), Water Desalination and Reuse Center (WDRC), Division of Biological and Environmental Science and Engineering (BESE), Thuwal 23955-6900, Saudi Arabia; Department of Biotechnology, Faculty of Applied Sciences, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands; Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911 MA Leeuwarden, The Netherlands. Electronic address: Hans.Vrouwenvelder@wetsus.nl.
authors.forename: Johannes S
authors.initials: JS
authors.lastname: Vrouwenvelder
authors.affiliation: Department of Biotechnology, Faculty of Applied Sciences, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands. Electronic address: C.Picioreanu@tudelft.nl.
authors.forename: Cristian
authors.initials: C
authors.lastname: Picioreanu
mesh_terms: D018441:Biofilms; D057219:Biofouling; D008567:Membranes, Artificial; D009995:Osmosis; D018508:Water Purification
chemical_list: D008567:Membranes, Artificial
keywords: Desalination; Forward osmosis fouling; Numerical model; Spiral-wound membrane module; Water filtration; Water reuse