Recent developments of anaerobic membrane bioreactors for municipal wastewater treatment and bioenergy recovery: Focusing on novel configurations and energy balance analysis

Municipal wastewater (MWW) produced in a stable and huge amount is increasingly regarded as a valuable resource for generating clean water, bioenergy and nutrients. Efficient bioenergy and bioresource recovery from the MWW are challenging in conventional aerobic and anaerobic biotechnologies due to technical limitations. The emerging anaerobic membrane bioreactors (AnMBRs) show great potential to overcome such limitations by integrating the merits of anaerobic digestion and membrane filtration. In this review, the fundamental aspects regarding MWW quality and process properties of AnMBRs are briefly introduced. Recent developments in AnMBRs towards performance enhancement, fouling mitigation and energy demand reduction are assessed in terms of process characteristics and energy efficiency. The promising AnMBR configurations targeted include biogas-sparging AnMBR, particle-fluidized AnMBR, granular-sludge AnMBR, anaerobic dynamic membrane bioreactor (AnDMBR) and anaerobic forward osmosis membrane bioreactor (AnFOMBR), with the energy balance systematically discussed as well as economic and environmental benefits briefly analyzed based on life cycle assessment (LCA) studies. Lastly, future perspectives for AnMBR research and development (R&D) are highlighted by a proposed technical framework with an emphasis on the pre-treatment and post-treatment options, dissolved methane management and process optimization, which are expected to advance large-scale AnMBR applications in an economically viable and environmentally sustainable manner. [Display omitted] •AnMBR is highly promising for low-carbon mainstream municipal wastewater treatment.•Novel AnMBR configurations established for fouling control and energy reduction.•Energy balance analysis indicated net energy-positive AnMBR operation achieved.•Life cycle assessment is important for AnMBR design and optimization.•Pre- and post-treatment, managing dissolved CH4 and large applications are crucial.