Biofouling mitigation and microbial community dynamics in the quorum quenching membrane bioreactors for industrial wastewater treatment

The research investigates the efficiency and applicability of quorum quenching (QQ) mechanism in membrane bioreactors (MBRs) in the treatment of industrial wastewater rich in inorganic pollutants such as salinity, sulfate and lead. In the study, a semi-pilot QQ MBR system was operated with inorganic pollutants representing petroleum and natural gas production wastewater, cement industry wastewater and textile industry wastewater. Rhodococcus sp. BH4 bacteria used as QQ bacteria did not have a negative effect on the organic matter removal efficiency and it was demonstrated that semi-pilot QQ MBR system is resistant to toxic shocks. The results showed that QQ MBR significantly reduced transmembrane pressure (TMP) increases under salinity, lead, and sulfate stress conditions. Moreover, QQ MBR had lower concentrations of soluble microbial products (SMP) and extracellular polymeric substances (EPS), which are key factors in biofilm formation, compared to Control MBR. Microbial community analysis revealed that QQ successfully maintained operational stability while regulating bacterial populations to minimize biofilm formation. This study highlights the potential of MBR systems utilizing the QQ mechanism to address challenges in industrial wastewater treatment, providing a promising solution to improve energy efficiency and extend membrane life under variable operational conditions.