Comparison of Aerobic and Anaerobic Membrane Bioreactors for Municipal Wastewater Treatment

An aerobic bioreactor and an anaerobic bioreactor, each coupled with a microfiltration membrane filter (MBR) were operated at different hydraulic retention time (HRT) with primary effluent from City of Elmhurst, Illinois, USA municipal wastewater treatment plant in the laboratory. The soluble COD removal performance of anaerobic MBR system was similar to that of aerobic MBR under same operational conditions, without the added cost of aeration. The results indicated that the solids deposition rate on the membrane surface was lower in the case of anaerobic MBR compared to the aerobic MBR, indicating possible lower loss in water flux rates. This research found that an anaerobic MBR is a feasible and economical option for municipal wastewater treatment plants seeking COD removal by biological process followed by separate nitrification and denitrification system.