Highly conductive graphene/PANi-phytic acid modified cathodic filter membrane and its antifouling property in EMBR in neutral conditions

• Polyester filter cloth was modified by Gr/PANi-phytic acid (PA) coating.
• The Gr/PANi-PA membrane had higher conductivity in neutral condition.
• Its electric resistance is 93% lower than the PANi-HA membrane.
• The Gr/PANi-PA membrane had the best anti-fouling property in EMBR.
• The Gr/PANi-PA membrane had smaller slopes in its t/V–V curves.

A novel membrane modification strategy for controlling fouling in filter membrane was presented. In this paper, electrically conductive membranes were prepared by coating graphene (Gr) and polyaniline (PANi) doped with phytic acid (PA) on polyester filter cloth. The Gr/PANi-PA modified membrane had a good conductivity and an excellent antifouling property, its electric resistance was 93% lower than the PANi-HA (doped with hydrochloric acid) modified membrane and 13% lower than the PANi-PA modified membrane. The antifouling performances of the modified conductive membranes were compared in EMBR (MBR, membrane bioreactor attached with a 0.2 V/cm electric field), tested by a short time filtration of a yeast suspension solution. The result indicated that the membrane with a higher conductivity had better antifouling property, smaller slopes in its t/V–V curves (adopting the classical cake filtration model, a suitable description for the membrane fouling process). The short-term cumulative permeate volume from the Gr/PANi-PA modified membrane was increased by ~ 58% after applying 0.2 V/cm electric field, while it was only ~ 10% for PANi-PA modified membrane.