Pilot Testing of an AnMBR for Municipal Wastewater Treatment

There is an increasing interest in wastewater treatment technologies that are sustainable. An example of this is the development of anaerobic processes such as anaerobic membrane bioreactors (AnMBRs) for wastewater treatment applications. This paper presents a long term pilot study that looked at effluent quality, energy recovery, membrane performance and sludge production of AnMBR technology while treating municipal wastewater. The pilot was fed with a screened raw sewage at an OLR of 0.58 kg COD/m3/day, HRT of 8.5 hours and SRT of about 80–100 days for about 160 days. During this period the membrane was operated continuously at a flux of 17 LMH, TMP of less than 5 kPa and no membrane fouling was observed. The average steady state membrane tank MLSS concentration was 13.4 g/L and critical flux was found in the range of 26 LMH. The BOD removal rate was 85 %. The COD balance analysis showed that 31 percent of the incoming total COD was recovered in the form of methane; however 19% was in liquid phase and exited the system with the permeate. A significant fraction of the incoming COD was also found to be non-biodegradable and led to COD accumulation within the bioprocess tank.