Enzyme-based control of membrane biofouling for water and wastewater purification: A comprehensive review

The current work provides an insight into biofouling and enzyme-based mitigating techniques during the application of membrane-based separation for water and wastewater purification. The study emphasizes underlying mechanisms of biofouling formation. The roles of extracellular polymeric substances (EPS) in the interaction with the membrane surface as well as in biofilm stability and diversity that govern biofouling severity are thoroughly discussed herewith. In addition to EPS, the quorum sensing (QS) process that regulates the bacterial communication process for biofilm formation and subsequent biofouling is also comprehensively reviewed. The relationship among EPS, QS, and biofouling is systematically described for the first time in this study. Derived from the appreciation of the EPS-QS-microbe nexus, an overall picture of the to date enzyme-based techniques and their underlying mechanisms to control and remove biofoulants is critically analysed and drawn for the first time. In this study, the limitations of the current biofouling control techniques are indicated before future research directions were proposed for further treatment improvement. (C) 2021 The Authors. Published by Elsevier B.V.