The role of a membrane performance enhancer in a membrane bioreactor: a comparison with other submerged membrane hybrid systems

Among the membrane processes, membrane bioreactor (MBR) technologies are becoming an innovative and promising option for wastewater treatment and reuse. In this study the performance of the submerged membrane bioreactor was studied with an addition of MPE50, and it was compared against a sponge submerged membrane bioreactor (SMBR) and submerged membrane adsorption bioreactor (SMABR) in terms of TOC removal, COD removal, ammonium nitrogen (NH4-H) removal, orthophosphate (PO4-P) removal, transmembrane pressure (TMP) and oxygen uptake rate. SMBR with MPE50 addition significantly improved the sustainable flux and reduced membrane fouling. The improvement was better than even in the sponge SMBR system. SMBR with MPE50 achieved a high DOC and COD removal efficiency and NH4-N removal. PO4-P removal concentration of 62% initially which increased with time to over 99% after 7 day operation. In terms of phosphorus removal the sponge SMBR system performed better. OUR measurements showed that there was more microbial activity in the SMBR with MPE50 system.

The SMBR with MPE addition significantly improved the sustainable flux and reduced membrane fouling. The improvement was better than for even the sponge SMBR system. The SMBR with MPE achieved a high DOC (over 95%) and COD removal efficiency (over 95%) when running over a 7-day period at a filtration flux of 30 L/m2.h. In addition, this system revealed outstanding NH4-N removal of over 95– 98% and PO4-P removal of concentration of 62% which increased with time to over 99% after 7 days of operation. In terms of phosphorus removal, the sponge system performed better. OUR 1 day 3 days 5 days 7 days 10 days 15 days DO concentration (%) 20 days Time (min) a) OUR variation of the mixed liquor in the SMBR system DO concentration (%) 2nd day 5th day 7th day Time (min) b) OUR variation of mixed liquor in the SMBR with MPE50 Fig. 5. DO efficiency profile of SMBR + MPE50 (filtration flux = 30 L/m2.h, MPE50 initial dose = 500 mg/L and daily addition of 80 mg/L, backwash rate = 30 L/m2.h, backwash = 1 min every 0.5 h).