Dynamic variation of microbial metabolites and community involved in membrane fouling in A/O-MBR

To explore the membrane biofouling process in detail, the dynamic metabolite variations and microbial community succession were investigated in an A/O-MBR system under constant flux. Along the TMP changes, three stages from the biofouling process were proposed and analyzed based on the metabolites and TMP. The total metabolites kept growing and enriching to the cake layer until stable, and the metabolites in activated sludge had a decline in the last biofouling days. The community structures of the cake layer and activated sludge were similar. Thiothrix eikelboomii and AS110 occupied the dominant place almost in all processes. Cupriavidus gilardii and Clostridium bifermentans only dominated the biofilm. The initially attached proteins played as the nucleus, and were followed by carbohydrates enrichment to the membrane in the initial stage. The metabolites variation corresponded to variation of bacteria from Acinetobacter, Clostridium, Ornithinimicrobium, Thiothrix and Veillonellaceae. A remarkable disturbance of metabolites and bacteria in the activated sludge was observed.