Incorporation of Quorum Sensing Inhibitors onto Reverse Osmosis Membranes for Biofouling Prevention in Seawater Desalination

Membrane biofouling, caused by bacterial biofilm formation is a significant obstacle for membrane filtration processes because it reduces pure water permeability. Recent studies have shown that bacterial communication pathways, known as quorum sensing (QS), trigger biofilm development. QS inhibiting compounds (QSIs) have been identified as an important key to disrupt QS pathways and ultimately reduce biofilm production. In this study, two known QSIs, vanillin and cinnamaldehyde, were physically attached onto polyamide thin-film composite reverse osmosis (RO) membranes to enhance membrane in situ antibiofouling potential. QSI attachment altered the membrane surface contact angle to reflect the property of the QSI, but there were no significant changes in salt rejection and pure water permeability. Under biofouling conditions, the QSI-modified RO membranes experienced a minimal loss in permeate flux compared with one of the control membranes in a high-pressure RO system. QSI attachment significantly reduced polysaccharide production (>15%), live bacteria (>58%), and dead bacteria (>61%) on the membrane surface in the bench-scale biofouling studies using a mixed culture of biofilm forming marine bacteria. Results of this study indicated that QSI membrane modification has the potential to achieve in situ reduction of membrane biofouling for RO seawater desalination.