Review of membrane aerated biofilm reactors

Membrane aerated biofilm reactors (MABRs) represent a new technology for ae robic wastewater treatment. Oxygen diffuses through a gas permeable membran e into the biofilm where oxidation of pollutants, supplied on the biofilm s ide of the membrane, takes place. The potential of this system for various wastewater treatment applications is reviewed in the context of recent deve lopments in the understanding of the fundamentals of such systems. The diff erence between MABRs and conventional biofilm reactors is highlighted by th e concept of active layers within biofilms and the importance of active lay er location. This review also discusses the choice of membrane in such reac tors and the development of mathematical models that describe MABR performa nce. All published studies on the use of MABRs are discussed under pollutan t species headings: organic carbonaceous pollutant biodegradation, volatile organic pollutant removal, and nitrification/denitrification processes. (C ) 1999 Elsevier Science B.V. All rights reserved.