High retention membrane bioreactors: Challenges and opportunities

• Published in: Bioresource technology 2014-09, Vol.167, p.539-546
• Main Authors: Luo, Wenhai, Hai, Faisal I., Price, William E., Guo, Wenshan, Ngo, Hao H., Yamamoto, Kazuo, Nghiem, Long D.
• Format: Article
• Language: English
• Subjects: Accumulation; Biological and medical sciences; Bioreactors; Biotechnology; Filtration; Forward osmosis (FO); Fundamental and applied biological sciences. Psychology; High retention membrane bioreactor; Membrane distillation (MD); Membranes; Membranes, Artificial; Methods. Procedures. Technologies; Nanofiltration (NF); Osmosis; Product innovation; Rejection; Salinity; Separation; Trace organic chemicals (TrOCs); Various methods and equipments; Waste water; Water Purification
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2014.06.016

•HR-MBR integrates high rejection membrane and biological treatment in a single step.•HR-MBR is compact and can offer high treatment capacity suitable for water reuse.•Salinity buildup, low flux, membrane stability must be addressed in future research.•Possible directions to address these challenges were suggested. Extensive research has focussed on the development of novel high retention membrane bioreactor (HR-MBR) systems for wastewater reclamation in recent years. HR-MBR integrates high rejection membrane separation with conventional biological treatment in a single step. High rejection membrane separation processes currently used in HR-MBR applications include nanofiltration, forward osmosis, and membrane distillation. In these HR-MBR systems, organic contaminants can be effectively retained, prolonging their retention time in the bioreactor and thus enhancing their biodegradation. Therefore, HR-MBR can offer a reliable and elegant solution to produce high quality effluent. However, there are several technological challenges associated with the development of HR-MBR, including salinity build-up, low permeate flux, and membrane degradation. This paper provides a critical review on these challenges and potential opportunities of HR-MBR for wastewater treatment and water reclamation, and aims to guide and inform future research on HR-MBR for fast commercialisation of this innovative technology.