Comparison of Performance of an Intermittent Aeration Membrane Bioreactor and a Conventional Activated-sludge System in the Treatment of Palm Oil Mill Effluent

The main objective was to compare the performances and the removal efficiencies of two biological treatment systems, a submerged membrane biorcactor (SMBR) and a simultaneous activated sludge (AS), for treating Palm Oil Mill Effluent (POME). Two lab scale units of 5MBR and AS with a working volume of 24 L were operated under favorable biological conditions and minimized membrane fouling intensity. To achieve both carbonaceous and nitrogen removal. the cyclic air int ermittent and dissolved oxygen control were performed into 5MBR and AS with the influent flow rate about 16 L/d respectively. In terms of organic removal and membrane performance, the 5MBR showed good removal efficiency to treat high strength wastewater with organic loading variation of POME. The average removal rates of TCOD, BOD, Turbidity, Color, Oil and Grease, NH3-N2, TKN were 69±2 , 76±2,100±1, 37±2 1, 92±6, 67±4 and 75±10% respectively. Results pointed out the benefit of memb ranes retained totally the active compositions of biomass in each stage of development. The AS showed the limitation of sedimentation phas e for sludge and oil separation. The charac teristics of sludge in 5MBR showed healthy floc formations and good settl ing after 240 h. The con centrations of COD and BOD in permeate were around 870±53 and 37±13 mg/L.