Quorum quenching for biofouling control in a semi-pilot-scale membrane bioreactor treating display manufacturing wastewater

Quorum quenching (QQ) technology, widely recognized for its effectiveness in mitigating membrane fouling in membrane bioreactors (MBRs), has been predominantly studied in laboratory-scale setups, with fewer applications in pilot-scale systems. Furthermore, most research in this field has been focused on using MBRs to treat synthetic wastewater or municipal sewage, with limited investigations into industrial wastewater treatment. In this study, we examined the feasibility of integrating QQ technology into a semi-pilot-scale MBR to treat wastewater from the display manufacturing industry and evaluated its antifouling performance. In semi-pilot-scale MBR operations, the QQ effect was associated with a significant delay in the increase in transmembrane pressure seen in an MBR without QQ. Simultaneously, we observed a reduction in N-acyl-homoserine lactone concentration in the sludge and extracellular polymeric substances in the biofilm attached to the membrane. The activity of the QQ beads remained stable and maintained their antifouling capability over 66 days of MBR operation. Microbial community analysis revealed that the QQ effect was correlated with changes in the abundance of specific microbial taxa (such as Rhizobiales) rather than causing significant shifts in the overall phylogenetic structure. The results of a functional gene analysis of acyl-homoserine lactone-related pathways indicate substantial reductions in related genes such as luxO, cciR, lasI, and bjaR1 in the QQ-MBR. These findings demonstrate that QQ technology can be effectively applied to full-scale MBR systems to treat industrial wastewater and offers a sustainable and efficient solution to mitigate biofouling challenges in wastewater treatment processes.