Coating of reverse osmosis membranes with amphiphilic copolymers for biofouling control

Abstract

a b s t r a c tSurface coating of membranes may be a promising option to control biofilm development and biofouling impact on membrane performance of spiral-wound reverse osmosis (RO) systems. The objective of this study was to investigate the impact of an amphiphilic copolymer coating on biofilm formation and biofouling control. The coating was composed of both hydrophilic and hydrophobic monomers hydroxyethyl methacrylate (HEMA) and perfluorodecyl acrylate (PFA), respectively. Commercial RO membranes were coated with HEMA-PFA copolymer film. Long and short term biofouling studies with coated and uncoated membranes and feed spacer were performed using membrane fouling simulators (MFSs) operated in parallel, fed with water containing nutrients. For the long-term studies pressure drop development in time was monitored and after eight days the MFSs were opened and the accumulated biofilm on the membrane and spacer sheets was quantified and characterized. The presence of the membrane coating was determined using X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). Results showed that the amphiphilic coating (i) delayed biofouling (a lower pressure drop increase by a factor of 3 and a lower accumulated active biomass amount by a factor of 6), (ii) influenced the biofilm composition (23% lower polysaccharides and 132% higher protein content) and (iii) was still completely present on the membrane at the end of the biofouling study, showing that the coating was strongly attached to the membrane surface. Using coated membranes and feed spacers in combination with advanced cleaning strategies may be a suitable way to control biofouling.

A Comprehensive Review on Polymeric Nano-Composite Membranes for Water Treatment

“…Antai et al [173][174][175][176][177][178][179][180][181][182][183][184][185][186][187] ) within GO was done via three different methods such as Pre-incorporation, Post-incorporation and Filter-incorporation. Metal cations used for membrane preparation used were non-toxic, environment friendly and cheap [188][189][190][191][192][193][194].…”

Review on strategies for biofouling mitigation in spiral wound membrane systems

“…Therefore, long-term studies (i.e., several months) are needed to investigate the effective impact of membrane surface modification on biofouling development. It has also been shown experimentally that long-term biofouling studies are more representative for practice than short-term protein and bacterial adhesion tests (Bucs et al, 2017;Louie et al, 2011;Miller et al, 2012).…”

“…Few studies investigating coated membranes to control fouling reported on the coating stability (Brzozowska et al, 2011;Bucs et al, 2017;Louie et al, 2006;Ronen et al, 2015). Brzozowska et al (2011) reported a weak attachment of polymer brushes to the membrane surface, with the coating layer easily removed by the water flow.…”

The membrane fouling simulator: development, application, and early-warning of biofouling in RO treatment

“…Such device should be representative for conventionally used membrane modules, thus involving the used materials (properties and structure) such as membrane and spacer, the height of the flow channels and hydraulics. The membrane fouling simulator (MFS) was introduced in 2006 [4] and since then many articles have appeared on various research aspects of biofilm characterization [2,3,[27][28][29][30][31][32][33][34][35][36], biofouling control [5,[37][38][39][40][41][42][43][44][45][46][47][48][49], and strategies for early warning of biofouling [50][51][52][53][54][55] applying the developed MFS.…”

“…Feed spacers have been shown to have a strong impact on biofouling [46]. MFS studies have been performed to evaluate feed spacers (i) as applied in practice, including varying spacer thickness [37], (ii) after modifications by hydrophilic, amphiphilic bactericidal and biocidal coatings [38,39,42], and with innovative geometries [29,44,48,86,87]. A novel strategy for a cost-effective development and evaluation of feed spacers was developed for biofouling and scaling control involving (i) numerical modeling, (ii) three-dimensional (3D) printing of spacers, and (iii) MFS testing of hydrodynamics and biofouling impact [43].…”