Enhancement of anti-fouling and contaminant removal in an electro-membrane bioreactor: Significance of electrocoagulation and electric field

Membrane fouling is one of the most challenging issues confining membrane bioreactors (MBRs) application. An integrated electro-MBR (eMBR) was established to explore the performance of antifouling and contaminants removal under the role of electrocoagulation (EC) coupled with an electric field (EF). During the 39 d of operation, the membrane service cycle of the eMBR after each hydraulic cleaning was similar to 8 d, on average, which was 1.3 times longer that of MBR. The eMBR exhibited a marked improvement in pollutant removal, with total phosphorus (TP) removal of similar to 99% and COD removal of similar to 85%. Results revealed that EC and EF increased the porosity and thickness of the cake layer due to floc size enhancement and particle polarization, resulting in the alleviation of membrane fouling. The energy consumption in eMBR and MBR was 45 and 50 kWh/m(3), respectively. EPSs experiments show the best EPSs removal efficiency of 90.6% and the highest membrane flux of 65.2% at 4 V/cm. Compared with the conventional MBR, high-throughput sequencing demonstrated an enriched microbial diversity in the eMBR due to the stimulation by the EF and EC, which, in turn, facilitated the improvement in contaminant removal. These findings provide new insight and principles for the design and operation of eMBRs.