Dual-Function Conductive Copper Hollow Fibers for Microfiltration and Anti-biofouling in Electrochemical Membrane Bioreactors

Abstract
Membrane bioreactors (MBRs) with polymeric/ceramic microfiltration (MF) membranes have been commonly used for wastewater treatment today. However, membrane biofouling often results in a dramatically-reduced service life of MF membranes, which limits the application of this technology. In this study, Cu hollow fiber membranes (Cu-HFMs) with low resistivity (104.8–309.8 nΩ·m) and anti-biofouling properties were successfully synthesized. Further analysis demonstrated that Cu-HFMs reduced at 625°C achieved the bimodal pore size distribution of ~1 μm and a porosity of 46%, which enable high N2 permeance (1.56 × 10−5 mol/m2 s pa) and pure water flux (5812 LMH/bar). The Cu-HFMs were further applied as the conductive cathodes, as well as MF membranes, in the electrochemical membrane bioreactor (EMBR) system that was enriched with domestic wastewater at an applied voltage of 0.9 V. Excellent permeate quality (Total suspended solids (TSS) = 11 mg/L) was achieved at a flux of 9.47 LMH after Cu-HFM filtration, with relatively stable transmembrane pressure (TMP) and low Cu2+ dissolvability (<25 μg/L). The anti-biofouling over time was demonstrated by SEM characterization of the rare biofilm formation on the Cu-HFM cathode surface. By using Cu-HFMs in EMBR systems, an effective strategy to control the membrane biofouling is developed in this study.

Citation
Liu D, Chen X, Bian B, Lai Z, Situ Y (2018) Dual-Function Conductive Copper Hollow Fibers for Microfiltration and Anti-biofouling in Electrochemical Membrane Bioreactors. Frontiers in Chemistry 6. Available: http://dx.doi.org/10.3389/fchem.2018.00445.

Acknowledgements
Funding: The authors are grateful for financial support from King Abdullah University of Science and Technology (KAUST) and Foshan University. Acknowledgments: DL is grateful for kind help from Dr. Yuanlie Yu and Dr. Yang Liu from AMPM center, KAUST. BB is grateful for kind advice from Dr. Pascal Saikaly and Dr. Krishna Katuri from Water Desalination and Reuse Center, KAUST.

Publisher
Frontiers Media SA

Journal
Frontiers in Chemistry

DOI
10.3389/fchem.2018.00445

Additional Links
https://www.frontiersin.org/articles/10.3389/fchem.2018.00445/full

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