Single layer graphene oxide (SLGO) was studied as a novel coating material to drastically improve the antifouling performance of polyether sulfone (PES) hollow fiber (HF) membranes in membrane bioreactor (MBR) application. By selectively modifying the membrane surface, only a small amount of SLGO coating (6.2 mg m 2 ) was needed to achieve acceptable membrane performance. The UV treatment of the SLGO coating further assisted in improving the antifouling properties of the asprepared PES HF membranes. By comparing the transmembrane pressure of pristine PES HF and PESGO 6.20 UV X (X 01.5 h) membranes in a MBR for wastewater treatment at a fixed water flux, the PESGO 6.20 UV 1.0 membrane coated with 1 h UVtreated SLGO was demonstrated to substantially relieve the biofouling problem. To understand the influence of SLGO modification on membrane performance, FESEM, ATRFTIR, and AFM analyses were conducted to characterize the asprepared membranes, and the SLGO deposition mechanism was also proposed in this study.
Membrane separation technology is an important option for the treatment of contaminated surface waters but the relatively high cost of materials and membrane fabrication represent a significant obstacle to the wider use of membrane processes. In this study, we describe the development and testing of a new kind of membrane made from twodimensional (2D) kaolin nanosheets. The fabrication involved a layerbylayer stacking of the nanosheets with a cationic polyacrylamide crosslinking agent, assembled on a cellulose acetate supporting layer. The kaolin membrane exhibited an ultrahigh flux (4000 L.m 2 .h 1 .bar 1 ) which was almost ten times greater than that of a commercial polyether sulfone (PES) ultrafiltration (UF) membrane. The membrane was tested using a range of influent water types, including samples of a lake water, river water and three natural organic matter solutions. The results showed that the kaolin membrane was stable and behaved as an UF membrane, in terms of its pore size distribution (peak distribution at 2035 nm) and comparable treatment performance to the PES UF membrane. The kaolin membrane showed a substantially reduced rate of fouling, compared to PES membrane, despite a much greater flux, which was partly attributed to its highly hydrophilic nature. The advantages of lower cost, much higher flux and lower fouling propensity make the 2Dkaolin membrane a potentially important development in UF membrane technology for drinking water treatment, and possibly other applications.