Facile fabrication of a conductive polypyrrole membrane for anti-fouling enhancement by electrical repulsion and in situ oxidation

Conductive membranes provide a promising method to alleviate membrane fouling, but their cost-effective fabrication, which is urgently needed, is still a challenge. This paper describes the facile fabrication of an ultrafiltration conductive polypyrrole (PPy)-modified membrane (PMM) by in situ chemical polymerization of FeCl3 and monomer pyrrole vapor on a commercial membrane surface. The resulting membrane had a high electrical conductivity and an outstanding water flux of 2766.55 L m(-2) h(-1) bar(-1). The preparation cost of the PPy deposition was $2.22/m(2), which was similar to 8% of the commercial ultrafiltration membrane cost. Once the PMM was charged at -1 V as a membrane electrode, the normalized water flux was maintained at 92.48 +/- 1.14% after fouling by bovine serum albumin (BSA) solutions, which was 18.82% higher than that when the PMM was not charged. The reduced membrane fouling was ascribed to the electrical repulsion between the negatively charged BSA and the PMM cathode. In addition, hydroxyl and sulfate radicals were generated by peroxymonosulfate (PMS) activation on the PMM surface through electron transfer by PPy, which facilitated foulant oxidation. The PPy on the PMM surface was oxidized after catalysis and electrochemically reduced when the PMM was charged as a cathode, exhibiting continuous catalytic ability for PMS activation. These findings provide an alternative method for the facile fabrication of cost-effective conductive membranes to mitigate membrane fouling. (C) 2020 Elsevier Ltd. All rights reserved.