Purpose — This review synthesizes the characteristics, applications, challenges, and recent technological advances of the anaerobic membrane bioreactor (AnMBR) as a low-carbon, resource-recovery option for wastewater treatment. Distinctively, the review links two full-scale cases with four emerging technologies to map recurrent constraints—fouling, dissolved methane, low-COD feeds, and sulfate—onto feasible technology routes.

Methods — The article adopts a narrative synthesis along four axes: (i) core process features of AnMBR; (ii) applications in municipal and industrial wastewaters; (iii) operational challenges; and (iv) explicitly discussed technologies, including forward-osmosis-coupled AnMBR (FO-AnMBR), anaerobic dynamic membrane bioreactor (AnDMBR), thermoresponsive membrane surface modification, and anaerobic membrane distillation bioreactor (AnMDBR).

Results — By decoupling hydraulic retention time and sludge retention time, AnMBR sustains high biomass concentrations, reduces excess sludge production, and yields clarified permeate. Within this operating envelope, reported energy demand spans 0.03–5.7 kWh·m⁻³, and typical flux is 5–12 L·m⁻²·h⁻¹. Early studies reported biochemical oxygen demand removal of 85–95% with concurrent nitrate and phosphate reduction. Later work confirms stable operation across matrices, including at low temperatures.

At the Spernal (UK) plant (18 °C), AnMBR effluent passes through ion exchange and hollow-fiber membrane contactors. Nitrogen recovery exceeds 76% (≈88% of plant nitrogen load captured). Phosphorus recovery is ≈80% as hydroxyapatite at pilot scale.

At the Pikeville (USA) food-industry facility, the line was upgraded to AnMBR followed by an aerobic membrane bioreactor (MBR). Influent chemical oxygen demand (COD) of 34 500 mg·L⁻¹ decreased to 160 mg·L⁻¹ with overall COD removal >99.5%; design flow and organic loading rate increased by 25% and 44%, respectively, and the produced biogas partly met the facility’s heating demand.

New technologies address identified constraints. FO-AnMBR pre-concentrates low-COD feeds, with COD enrichment >300% using 3.5% synthetic seawater and flux of 3–7.4 L·m⁻²·h⁻¹. AnDMBR uses a regenerable dynamic cake on low-cost supports and has shown >99% COD removal on high-strength wastewaters. Thermoresponsive grafted coatings enable warm-water, chemical-lean cleaning. AnMDBR improves effluent polishing while maintaining stable flux and achieves complete total phosphorus and ≥98% dissolved organic carbon removal on specific hydrophobic polymers.

Conclusions — This review shows that AnMBR fits low-carbon objectives when aeration is avoided and resource recovery is planned. Reliable application requires: (i) chemical-lean fouling control; (ii) dissolved-methane management linked to downstream use; (iii) materials compatibility and operating strategies for sulfate-rich or inhibitory matrices; and (iv) deployment of fit-for-purpose modules with nutrient recovery. These points define the deployment window for AnMBR and the near-term tasks for scale-up and commercialization.