Development of a high-rate submerged anaerobic membrane bioreactor

Typically, anaerobic membrane bioreactors are operated at an organic loading rate (OLR) less than 10 kg chemical oxygen demand (COD)/m³d. This paper discusses the development and performance of a high-rate submerged anaerobic membrane bioreactor (SAnMBR) for a high-strength synthetic industrial wastewater treatment. An OLR as high as 41 kg COD/m³ d was achieved with excellent COD removal efficiency (>99%). The membrane was operated at constant fluxes (9.4-9.9 ± 0.5 L/m² h) and the change in trans-membrane pressure (TMP) was monitored to characterize the membrane performance. The results showed a low TMP (<5 kPa) under steady-state operation with only biogas sparging and relaxation as control strategy for over 300 days, implying no significant fouling was developed. Inorganic fouling was the dominant fouling mechanism occurred at the end of the study. The results suggest that the newly developed SAnMBR configuration can treat high-strength wastewater at lower capital expenditure while still providing superior effluent quality for water reuse or system closure.