High flux carbon fiber cloth membrane with thin catalyst coating integrates bio-electricity generation in wastewater treatment

• Effective Pd-RGO-CoFe2O4 was first tested as cathode catalyst in MFC/MBR.
• The cathode membrane with carbon fiber cloth, catalyst and PVDF binder performed well.
• Decreasing the PVDF/catalyst thickness increased the conductivity of catalyst layer 1000 times.
• Addition of nano-catalyst in PVDF binder greatly enhanced membrane flux.

In this study, a catalytic cathode membrane based on carbon fiber cloth was successfully prepared, and it integrated microbial fuel cell (MFC) with membrane bioreactor (MBR). Nanoparticle Pd-RGO-CoFe2O4 catalyst was synthesized in one-step, using ethylene glycol as reduction agent, and assisted by microwave reduction. It was coated with polyvinylidene fluoride (PVDF) binder on carbon fiber cloth, with followed phase inversion. The formed composite cathode membrane with the blended and fixed Pd-RGO-CoFe2O4 catalyzed bio-electricity generation in coupled MFC/MBR system. Besides its high pure water membrane flux (59,817 LMH bar−1) and high conductivity (15.2×10−2 S cm−1), it also performed well in membrane fouling reduction and energy production (683 mW m−3). By thinning the PVDF coating from 700 μm to 300 μm, the surface conductivity of the catalyst layer in cathode membrane increased approximately 1000 times (from 3.1×10−6 S cm−1 to 3.3×10−3 S cm−1), and it can improve the catalytic activity towards oxygen reduction reaction (ORR). The catalyst in PVDF binder could greatly improve the porosity of membrane. By comparing the ratio of Pd:RGO in catalyst and bio-generation, it was proved that 1:1 ratio was better than 1:2 or 2:1.

Figure optionsDownload high-quality image (189 K)Download as PowerPoint slide