A Simple way to Improve a Conventional A/O-MBR for High Simultaneous Carbon and Nutrients Removal from Synthetic Municipal Wastewater

Abstract

In this study, two anoxic-oxic-MBR systems (conventional and biofilm) were operated in parallel under complete SRT to compare system performance and microbial community composition. Moreover, with the microbial communities, comparisons were made between adhesive stage and suspended stage. High average removal of COD, NH4+-N and TN was achieved in both systems. However, TP removal efficiency was remarkably higher in BF-A/O-MBR when compared with C-A/O-MBR. TP mass balance analysis suggested that under complete SRT, sponges play a key role in both phosphorus release and accumulation. The qPCR analysis showed that sponge biomass could maintain higher abundance of total bacteria than suspended sludge. Meanwhile, AOB and denitrifiers were enriched in the suspended sludge rather than the sponge biomass. Results of pyrosequencing reveal that the compacted sponge in BF-A/O-MBR could promote the growth of bacteria involved in nutrient removal and reduce the filamentous and bacterial related to membrane fouling in the suspended sludge.