Contact
    Start Publications Assessment of physicochemical interactions in hollow fibre ...
    ←  Publication Finder
    Attension

    Assessment of physicochemical interactions in hollow fibre ultrafiltration membrane by contact angle analysis

    Year: 2012

    Journal: Journal of Membrane Science 2012, 403-404 pp 32-40, 20121211

    Authors: Nashida Subhi, Arne R.D. Verliefde, Vicki Chen, Pierre Le-Clech

    Organizations: UNESCO Centre for Membrane Science and Technology, School of Chemical Engineering, The University of New South Wales, NSW, Australia; Particle and Interfacial Technology Group, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium; Department of Sanitary Engineering, Faculty of Civil Engineering and Geosciences, Delft University of Technology, Stevinweg 1, 2628CN Delft, The Netherlands

    One critical issue faced during membrane operation is the occurrence of fouling, which partially results from the foulant-membrane affinity, often broadly attributed to “hydrophobicity”. Not only the simple concept of hydrophobicity fails to accurately assess membrane performance, but it also leads to over-simplified assumptions on phenomena occurring at the membrane surface during filtration. Foulant deposition on membrane surface is generally controlled by short-range non-electrostatic interactions. The energy related to the interactions between foulant and membrane surface in water can easily be described by the various surface tension components of the different phases. However, the determination of these surface tension components has been, so far, difficult to assess. In this study, specific experimental conditions were used to better characterise the surface tensions of membrane and foulants through contactangleanalysis. Polyvinylidene fluoride (PVDF) hollowfibreultrafiltration (UF) membrane was used with sodium alginate (SA), bovine serum albumin (BSA) and humic acid (HA) as foulants, representing polysaccharides, proteins and humic substances respectively. The novel approach proposed in this paper was to characterise simultaneously the initial and the subsequent membrane and foulant interactions during constant flux filtration with contactangleanalysis and calculation of surface free energy of adhesion and cohesion for various foulants. This was possible by considering the free energy of interactions of extended Derjaguin–Landau–Verwey–Overbeek (xDLVO) theory to predict and evaluate fouling mechanisms. Real wastewater samples were also used for fouling experiments, to assess the applicability of xDLVO theory for complex mixture of organics. This study demonstrated that the surface free energy components calculated for the range of wastewaters tested successfully predicted the organic deposition on membrane surface, as higher organic deposition was observed for high surface free energy surfaces.