title: Hydrogel-coated feed spacers in two-phase flow cleaning in spiral wound membrane elements: a novel platform for eco-friendly biofouling mitigation.
abstract: Biofouling is still a major challenge in the application of nanofiltration and reverse osmosis membranes. Here we present a platform approach for environmentally friendly biofouling control using a combination of a hydrogel-coated feed spacer and two-phase flow cleaning. Neutral (polyHEMA-co-PEG10MA), cationic (polyDMAEMA) and anionic (polySPMA) hydrogels have been successfully grafted onto polypropylene (PP) feed spacers via plasma-mediated UV-polymerization. These coatings maintained their chemical stability after 7 days incubation in neutral (pH 7), acidic (pH 5) and basic (pH 9) environments. Anti-biofouling properties of these coatings were evaluated by Escherichia coli attachment assay and nanofiltration experiments at a TMP of 600 kPag using tap water with additional nutrients as feed and by using optical coherence tomography. Especially the anionic polySPMA-coated PP feed spacer shows reduced attachment of E. coli and biofouling in the spacer-filled narrow channels resulting in delayed biofilm growth. Employing this highly hydrophilic coating during removal of biofouling by two-phase flow cleaning also showed enhanced cleaning efficiency, feed channel pressure drop and flux recoveries. The strong hydrophilic nature and the presence of negative charge on polySPMA are most probably responsible for the improved antifouling behavior. A combination of polySPMA-coated PP feed spacers and two-phase flow cleaning therefore is promising and an environmentally friendly approach to control biofouling in NF/RO systems employing spiral-wound membrane modules.
authors.affiliation: University of Twente, Membrane Science and Technology, MESA+ Institute of Nanotechnology, Faculty of Science and Technology, P.O. Box 217, 7500 AE Enschede, The Netherlands; Wetsus, Centre of Excellence for Sustainable Water Technology, P.O. Box 1113, 8900 CC Leeuwarden, The Netherlands.
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Wibisono
authors.affiliation: Linköping University, Division of Molecular Physics, Department of Physics, Chemistry and Biology (IFM), SE-581 83 Linköping, Sweden.
authors.forename: Wetra
authors.initials: W
authors.lastname: Yandi
authors.affiliation: Linköping University, Division of Biosensors and Bioelectronics, Department of Physics, Chemistry and Biology (IFM), SE-581 83 Linköping, Sweden.
authors.forename: Mohsen
authors.initials: M
authors.lastname: Golabi
authors.affiliation: Linköping University, Division of Molecular Physics, Department of Physics, Chemistry and Biology (IFM), SE-581 83 Linköping, Sweden.
authors.forename: Roni
authors.initials: R
authors.lastname: Nugraha
authors.affiliation: KWR Watercycle Research Institute, P.O. Box 1072, 3430 BB Nieuwegein, The Netherlands.
authors.forename: Emile R
authors.initials: ER
authors.lastname: Cornelissen
authors.affiliation: University of Twente, Membrane Science and Technology, MESA+ Institute of Nanotechnology, Faculty of Science and Technology, P.O. Box 217, 7500 AE Enschede, The Netherlands. Electronic address: a.j.b.kemperman@utwente.nl.
authors.forename: Antoine J B
authors.initials: AJ
authors.lastname: Kemperman
authors.affiliation: Linköping University, Division of Molecular Physics, Department of Physics, Chemistry and Biology (IFM), SE-581 83 Linköping, Sweden.
authors.forename: Thomas
authors.initials: T
authors.lastname: Ederth
authors.affiliation: University of Twente, Membrane Science and Technology, MESA+ Institute of Nanotechnology, Faculty of Science and Technology, P.O. Box 217, 7500 AE Enschede, The Netherlands.
authors.forename: Kitty
authors.initials: K
authors.lastname: Nijmeijer
mesh_terms: D018441:Biofilms; D057219:Biofouling; D004926:Escherichia coli; D005374:Filtration / Q000295:instrumentation* / Q000379:methods; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D008567:Membranes, Artificial; D011126:Polypropylenes / Q000737:chemistry; D018508:Water Purification / Q000295:instrumentation* / Q000379:methods
chemical_list: D008567:Membranes, Artificial; D011126:Polypropylenes; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate
keywords: Biofouling; Charge; Feed spacer; Hydrogel; Spiral-wound membrane; Two-phase flow