The membrane aerated biofilm reactor (MABR) process is an innovative technology that reportedly enables existing conventional activated sludge (CAS) plants to nitrify and denitrify without the addition of new tanks and, at the same time, helps reduce the energy required for aeration. In contrast to other membrane technologies, the membrane is used to deliver the oxygen required for wastewater treatment rather than providing any type of filtration. MABRs offer counter diffusion delivery of electron donor and acceptor, allowing independent control of each with stated attributes including high transfer efficiency, high substrate utilization rates, and reduced volatile organic compound emission due to bubbleless oxygenation. MABRs have been successfully applied for treatment of carbonaceous wastewaters, nitrification and denitrification, mostly at laboratory and demonstration units at pilot scale. Full scale application of the MABR technology is recent and results are still somewhat limited. This paper will provide an overview of the MABR technology with description of the three main technologies available from Suez, Oxymem, and Fluence, along with a comparison with CAS and discussion of appropriate configurations for domestic wastewater treatment (e.g. side stream, IFAS configuration, etc.). A summary of results available from both pilot and full scale will be provided along with a discussion on potential operation and maintenance issues. This paper will help inform municipalities, regulators and other consultants of the potential of this developing technology to be used on existing plant upgrades and address problems related to organic overloading and nutrient removal performance.
