Potential of aerobic granular sludge membrane bioreactor (AGMBR) in wastewater treatment

This investigation is a review of the potential of aerobic granular sludge membrane bioreactor (AGMBR) in wastewater treatment due to the advantage of combination of membrane and aerobic granules for reducing membrane fouling and enhancing removal performance. The AGMBR is the same as the membrane bioreactor (MBR), but the activated sludge is replaced by aerobic granular sludge. This technology combines the advantages of aerobic granular sludge, such as good settleability, strong ability to withstand shock-loadings and high organic loading rate, and capacity of simultaneous chemical oxygen demand (COD) and nitrogen removal, and advantages of membrane bioreactor (MBR) such as excellent effluent quality, high biomass content, low excess sludge production, and small land requirement. Therefore, it can be considered a promising option for efficient wastewater treatment. Most studies have shown that aerobic granules could control membrane fouling, which often occurs in MBR. The main fouling mechanism was determined to be surface fouling by floccular sludge in MBR but pore fouling by colloids and solutes in AGMBR. Aerobic granular sludge also removed COD and nitrogen simultaneously, with more than 60% total nitrogen removal efficiency. The formation and stability of aerobic granules in AGMBR with various operational modes are discussed in this study.