Finding Knowledge Gaps in Aerobic Granulation Technology.

This review identifies the knowledge gaps in aerobic granulation technology and defines some problems for future studies. In particular, extracellular polymeric substances (EPSs) should be further characterized to understand the intermolecular interactions among these polymers, the role of chelating agents in destabilizing EPS ionic bridges needs further elucidation, and early detection of the quorum-quenching enzymes should be considered to avoid granule segregation and process failure. Furthermore, the process should be supplemented with volatile fatty acids as electron donors/carbon sources, and appropriate anoxic/anaerobic conditions should be provided for enhanced nitrogen and phosphorus removal. Finally, the biodegradation, bioaccumulation, biosorption, and mass transfer behaviors of the emerging contaminants within the granules need further investigation.