Membrane fouling behaviors of ceramic hollow fiber microfiltration (MF) membranes by typical organic matters

Membrane fouling is a prevalent problem faced by all membrane-based applications, which is affected by membrane features, foulant properties and solution chemistry conditions. Here in this study, we explored the fouling behaviors induced by three typical organic matters (Humic acid (HA), Sodium alginate (SA) and Bovine Serum Albumin (BSA)) during the filtration process of two self-made ceramic hollow fiber MF membranes (denoted as Titania and Alumina, respectively), and compared with that of one commercial PVDF MF membrane. Extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory was employed to investigate the interfacial energy between foulants and different membranes. The results indicated that the anti-fouling ability of the three membranes followed the order: Titania > Alumina > PVDF. Further, it was found that regardless of the membrane features, increase of solution pH improved the interfacial free energy and thus mitigating membrane fouling. The addition of Na+ decreased the fouling tendency of HA and SA, but enhanced the fouling behavior by BSA, while Ca2+ can enhance all the fouling tendency of HA/SA/BSA. Co-existence of different organic matters resulted in a more complex fouling variation, which can not be well described with XDLVO theory. Our research is expected to provide a fundamental reference for MF membrane selection in practical application.