Evaluating the effect of aeration rate on quorum quenching membrane bioreactors: Performance of activated sludge, membrane fouling behavior, and the energy consumption analysis

Microbial quorum quenching (QQ) has recently been proven to be an efficient approach to mitigate biofouling in membrane bioreactors (MBRs). It can reduce biopolymers production and improve sludge conditions. Also, aeration intensity is considered to be directly interconnected with membrane fouling. In this study, the impact of aeration rate on the performance, membrane fouling, and the energy consumption of quorum quenching membrane bioreactor (QQ-MBR) and conventional membrane bioreactor (C-MBR) were exposed. We investi-gated the synergistic effects of aeration intensity and QQ on membrane fouling control in MBRs and analyzed the energy consumption of reactors under different conditions. QQ was found to mitigate biofouling significantly, but the membrane fouling mitigation efficiency was lowest (only 17.9 %) at high aeration intensity. Moreover, QQ reduced the content of SMP and EPS in sludge (over 20 % decreasing), and a better QQ performance was observed at middle aeration intensity. As for energy consumption, the most energy was consumed at high aeration intensity. QQ can minimize the aeration intensity required for the regular operation of MBR, thereby optimizing the energy consumption.

Automated summary

Microbial quorum quenching (QQ) is an effective approach to mitigate biofouling in MBRs by reducing biopolymers production and improving sludge conditions. This study investigated the impact of aeration rate on the performance, membrane fouling, and energy consumption of QQ-MBR and C-MBR. It was found that QQ significantly mitigates biofouling, but the efficiency is lowest at high aeration intensity. QQ also reduces the content of SMP and EPS in sludge, with better performance at moderate aeration intensity. High aeration intensity results in the highest energy consumption, while QQ can optimize energy consumption by minimizing aeration intensity.