Review of membrane aerated biofilm reactors

Membrane aerated biofilm reactors (MABRs) represent a new technology for aerobic wastewater treatment. Oxygen diffuses through a gas permeable membrane into the biofilm where oxidation of pollutants, supplied on the biofilm side of the membrane, takes place. The potential of this system for various wastewater treatment applications is reviewed in the context of recent developments in the understanding of the fundamentals of such systems. The difference between MABRs and conventional biofilm reactors is highlighted by the concept of active layers within biofilms and the importance of active layer location. This review also discusses the choice of membrane in such reactors and the development of mathematical models that describe MABR performance. All published studies on the use of MABRs are discussed under pollutant species headings: organic carbonaceous pollutant biodegradation, volatile organic pollutant removal, and nitrification/denitrification processes. (C) 1999 Elsevier Science B.V. All rights reserved.