Anti-biofouling behavior of quorum quenching for removal of pharmaceuticals by forward osmosis membrane based on pseudomonas quinolone signals

In this study, the effects of Pseudomonas quinolone signal (PQS) based quorum quenching (QQ) on biofouling control and the mitigated biofouling on the rejection of pharmaceutically active compounds (PhACs) i.e., carbamazepine (CBZ) and sulfamethoxazole (SMZ) in forward osmosis (FO) were systematically investigated. The results showed that methyl anthranilate (MA), the inhibitor of the PQS pathway, efficiently alleviated biofouling. Compared to that in the control experiment, the normalized fluxes at the optimal concentrations of MA was mitigated by 21%, and the amount of secreted biomass was reduced by nearly 50%. The two selected PhACs exacerbated biofouling and diminished the effects of the inhibitor on biofouling control. The rejections of CBZ and SMZ showed similar trends of first decreasing and then increasing during the 48-h dynamic biofouling experiment. The solution-dilution effect led to higher rejection of PhACs at the initial stage; then, the concentration polarization caused by the biofilms reduced the rejections of the two PhACs; subsequently, steric hindrance played a dominant role, resulting in an increase of the rejection.