Membrane fouling in an anaerobic membrane bioreactor: Differences in relative abundance of bacterial species in the membrane foulant layer and in suspension

▶ An anaerobic membrane reactor (AnMBR) was tested for biofouling by using polyvinylidene fluoride ultrifiltration membrane coated with PEBAX (cPVDF) vs an uncoated polyetherimide (PEI) ultrafiltration membrane. ▶ OP11 bacteria were present at high abundance in the fouling layers of both membranes. Other species were present at high abundance in suspended biomass. ▶ Extracellular polymeric substance (EPS) in AMRR was mainly proteinaceous. Both EPS and bacterial cells, especially OP11, caused biofouling. ▶ Fouling of PEI membrane was faster than cPVDF.