Recent developments in anammox-based membrane bioreactors: A review.

The anammox-based process has been considered a promising biological nitrogen elimination method for the treatment of nitrogen-rich wastewater ever since its discovery 40 years ago. However, the slow growth rate of anammox bacteria and severe sludge washout result in a long startup period and limit its widespread industrial application. A membrane bioreactor (MBR) is considered an ideal reactor for the operation of the anammox-based process because the membranes allow for 100 % biomass retention. According to a systematic review of the literature, anammox-based MBR is becoming a research hotspot in the field of nitrogen wastewater treatment. The fundamental understanding of anammox-based MBR and its membrane fouling situation is essential for the development and application of anammox-based MBR. In this paper, the application of MBR in different kinds of anammox process are reviewed. The membrane fouling mechanism and strategies to control membrane fouling are also proposed. It is expected that this review will serve as an invaluable guide for future research and in the engineering applications of anammox-based MBR process.