Membrane Aerated Biofilm Reactor (MABR)—Distributed Treatment of Wastewater at Low Energy Consumption

Abstract

Membrane-aerated biofilm reactor (MABR) is an energy efficient biological wastewater treatment process, based on passive aeration: by diffusion of oxygen through membranes, which also support an aerobic biofilm. The theoretical energy savings of MABR over that of conventional activated sludge (CAS) process were calculated to 86.8%. The paper analyzes two case studies of MABR implementation: one treating 25,000 GPD (95 m3/day) of municipal wastewater at US Virgin Islands and the second treating 125 m3/day of concentrated wastewater at Ha-Yogev WWTP in Israel. Energy consumption was measured and averaged over 2 months of operation. The results show the energy consumption for operation of the secondary treatment with MABR amounts to 0.212 kWh/m3 at the first case, while removing 98.9% BOD, 94.8% of NH4, and 96.8% of TSS. In the second case, the energy consumption for operation of the secondary treatment was below 0.4 kWh/m3 for the biological treatment achieving the required removal rates. By consuming very low energy at small treatment capacities, MABR supports the most important principles in water and energy efficiency: reduced energy for treatment and local water reuse.