Targeted ecological regulation of signal-responsive taxa drives biofouling mitigation in quorum-quenching membrane bioreactors.

This study investigated the effects of alginate-powdered activated carbon-quorum quenching (APQ) beads on microbial communities in MBRs treating real semiconductor wastewater. The addition of APQ beads significantly reduced membrane biofouling and extended membrane lifespan. The APQ-MBR maintained stable treatment performance with approximately 99% COD removal while reducing extracellular polymeric substances (EPS) and alleviating membrane biofouling. Taxonomic analysis revealed that QQ had limited influence on overall microbial diversity but affected the abundance of several bacterial genera in both mixed liquor and biofilm, including a reduction in the biofouling-associated genus Ferruginibacter and an enrichment of Bradyrhizobium. Correlation analysis further revealed associations between specific bacterial genera, N-butanoyl-l-homoserine lactone (C4-HSL), and EPS components. These results suggest that QQ-mitigated membrane biofouling mitigation is associated with changes in selected microbial populations involved in biofilm formation rather than broad alteration of the overall microbial community.