Development of quorum quenching cell entrapping carrier for mitigating membrane fouling in MBR

In the membrane bioreactor (MBR) process, problems such as performance deterioration due to membrane fouling, Excessive energy and chemical usage. This study aimed to develop a cell-entrapping carrier (CEC) using the quorum quenching (QQ) mechanism to inhibit fouling in MBR reactors. And this study aimed to develop a strategic plan for mitigating biofouling and reducing operational costs through the application of QQ-CEC. A solution comprising polyvinyl alcohol (PVA) and sodium alginate (SA) with Rhodococcus sp. BH4 was subjected to 1st and 2nd cross-linking reactions to complete CEC formation and evaluated its physical performance. Subsequently, definiting three types of conventional MBR with no CEC (cMBR), vacant-CEC (vMBR) and QQ-CEC (QMBR) were operated to investigate the carrier effect. The QMBR extended the operation duration to reach permissible TMP by more than 2.54 times that of the MBR and 1.35 times that of the vMBR. Furthermore, it has been established that biofouling can be mitigated through the application of QQ, resulting in a reduction of chemical usage by approximately 39.2%. Following operation of the QMBR, confirming that QQ-CEC inhibited biofouling. The extracellular polymeric substances (EPS) generated on the membrane surface was found to be 0.32 mg·L^-1·day-1 per cumulative permeate volume that was less than 4 times and 2 times lower compared to the cMBR and vMBR. However, no significant differences in effluent quality were observed, as QQ did not have a substantial impact on the alterations in microbial communities. This study addresses membrane bioreactor (MBR) fouling and optimizes process operations, thereby establishing a foundation for scale-up.