Exploring the applications and carbon reduction of multi-technology-coupled membrane biofilm reactors for sustainable wastewater treatment: a review

Abstract

Membrane biofilm reactors (MBfRs), which efficiently remove pollutants and reduce carbon emissions, hold great promise for wastewater treatment. However, the lack of a cheap local supply of hydrogen, uncontrolled substrate competition, and other issues pose challenges on the long-term stability of these reactors. At the same time, membrane bioreactors have strong bonding capabilities and can be coupled with a variety of processes. Therefore, these reactors are coupled with metal catalysts, electrochemistry, or anaerobic ammonia oxidation (anammox) technology to overcome these challenges. Metal catalysts reduces the replacement cycle and improves the operation stability of MBfRs, while electrochemistry removes pollutants in situ along with providing sufficient hydrogen. When coupled with anammox, the performance of the reactor improves and the energy consumption reduces. In this review, coupling of the hydrogen-based membrane biofilm reactor with the above technologies is discussed in view of their practical applications. Furthermore, their working principles, carbon emission reduction and applications are analyzed. Based on these, practical application and carbon emission reduction of membrane biofilm reactors are discussed along with providing ideas on overcoming their limitations.