The membrane-aerated biofilm reactor (MABR) is an emerging wastewater treatment process that can greatly decrease energy requirements for wastewater treatment. It is based on cassettes of air-supplying, hollow-fiber membranes that can retrofit existing activated sludge processes. In order to maximize MABR nitrification fluxes, a basic understanding and assessment of MABR behavior is needed. This thesis uses modeling and bench-scale tests to explore the range of potential nitrification fluxes and approaches to maximize fluxes.