Promoted biodegradation of para-ester wastewater by electrostimulated ZVI assisting novel UBF/ceramic membrane MBR and microbial community

•Porous functional ceramic filter in UBF can effectively prevent the massive sludge washout.•Satisfactory pollutants removal was achieved in foam ceramics UBF-MBR.•Successful operation of the combined UBF even at the COD/(sulfate plus organic S) of 1.57 at the OLR up to 6.8 g COD/L/d.•A specie of VFA utilizing SRB, desulfarculus was found after a long -term run.•Nano-ceramic membrane - based MBR performed well over the following 75 days.