Preparation of highly conductive cathodic membrane with graphene (oxide)/PPy and the membrane antifouling property in filtrating yeast suspensions in EMBR

The EMBR (MBR, attached with electric field) is effective in suppressing membrane fouling. In this paper, modified polyester cathode membranes were prepared by coating graphene (Gr)/polypyrrole (PPy) or graphene oxide (GO)/PPy, which had higher conductivity and better antifouling property in EMBR than the membrane modified with PPy only. The membrane modification using a vapor phase polymerization method (VPM) was proved better than using a liquid phase polymerization method (LPM). The modified membranes were tested and compared for antifouling performances in EMBR, by short time filtration of a yeast suspension, under 1 V/cm electric field. The VPM Gr/PPy modified membrane suppressed membrane fouling and increased the flux as high as 20%. The VPM Gr/PPy coating was more uniform and firm, and had higher conductivity (resistance lowered by 67%) than PPy modified membrane. It had better antifouling performance, smaller slopes in its t/V–V curves (adopting the classical cake filtration model, a suitable description for the membrane fouling process). By applying 1 V/cm electric field, an increase of 20% in the short-term cumulative permeate volume was obtained for the Gr/PPy modified membrane and it was only 10% for PPy modified membrane.

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► Gr/PPy membrane was successfully prepared by VPM.
► Gr/PPy membrane by VPM has excellent interfacial bonding and higher conductivity.
► The Gr/PPy membrane suppressed fouling more effectively than PPy membrane at 1 V/cm.
► The total permeate increase was more significant in EMBR for the Gr/PPy membrane.