Perspective trends of osmotic membrane bioreactor hybrid system for a circular economy

The osmotic membrane bioreactor (OMBR) is an innovative technology that combines forward osmosis with traditional activated sludge processes to enhance wastewater treatment and resource recovery within a circular economy. Despite its advantages, such as reduced energy consumption and improved contaminant removal, OMBR faces challenges, including salt accumulation and membrane fouling. This article comprehensively discusses recent advancements in OMBR technology, encompassing its fundamental principles, applications, and limitations. The study firstly highlights progress in draw-solution (DS), interactions within microbial communities, and system configurations, including hybrid systems for wastewater treatment and resource and energy recovery. Then, this study addresses research gaps related to greenhouse gas (GHG) emissions, energy efficiency, and the integration of artificial intelligence (AI) in OMBR systems. The results indicate that the OMBR can achieve a contaminant removal efficiency of over 80 %, underscoring its potential applicability in wastewater treatment. For the hybrid system operating with a DS concentration of 40 g/L NaCl, the energy consumption is estimated to range 2.5 ∼ 3.0 kWh/m³ (e.g., ultrafiltration with OMBR), corresponding to GHG emissions of 1.5 kg CO₂e per m³ of treated water. These GHG emissions are primarily attributed to the subsequent recovery of the DS. This study also introduces strategies for integrating OMBR within sustainable practices, such as using hybrid systems for phosphorus and biogas recovery. Moreover, the findings suggest that AI-driven strategies can optimize operational parameters, enable predictive maintenance, and improve overall performance. These innovations not only enhance the feasibility of OMBR but also establish it as a crucial technology for sustainable wastewater management and environmental preservation. This article concludes with a forward-looking outlook on the role of multifunctional OMBR systems in realizing a low-carbon and resource-efficient circular economy.