Biofouling mitigation using Piper betle extract in ultrafiltration MBR

Abstract

The control of membrane biofouling in the presence of Piper betle extract (PBE) as a biofouling reducer (BFR) has been investigated. Response surface methodology (RSM) has been employed to mitigate extracellular polymeric substances (EPS), transmembrane pressure (TMP) rise-up control, and dye removal in membrane bioreactor. Factors investigated were: BFR dosage, air flow rate, and hydraulic retention time (HRT). Optimum conditions found to be BFR of 0.23 mg/mg mixed liquor suspended solids, HRT of 30.16 h, and air flow rate of 0.60 l/min, with predicted values as 28.28 mg/l of EPS, 24.16 kPa of TMP, and 95.65% dye removal, respectively. Validatory tests were carried out under the optimum conditions, which were closely agreed with the predicted values. These results depicted that RSM was one of the suitable methods to optimize the operating conditions to mitigate fouling in the presence of a BFR. PBE was verified to mitigate membrane biofouling via inhibiting autoinducers production. Furthermore, it was found that the addition of PBE decreased the amount of EPS in biocake; whereas the addition of autoinducer increased it. These findings revealed that PBE could be a novel agent to target quorum sensing, to mitigate membrane biofouling.