Navigating Wastewater Energy Recovery Strategies: A Life Cycle Comparison of Anaerobic Membrane Bioreactor and Conventional Treatment Systems with Anaerobic Digestion

• Published in: Environmental science & technology Vol. 48; no. 10; pp. 5972 - 5981
• Main Authors: Smith, Adam L, Stadler, Lauren B, Cao, Ling, Love, Nancy G, Raskin, Lutgarde, Skerlos, Steven J
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 20.05.2014
• Subjects: Anaerobiosis; Applied sciences; Biogas; Biological and medical sciences; Biological treatment of waters; Biomass; Biomass energy; Bioreactors; Biotechnology; Conservation of Energy Resources - economics; Conservation of Energy Resources - methods; Costs and Cost Analysis; Emissions; Energy; Environment and pollution; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Global Warming; Industrial applications and implications. Economical aspects; Life cycles; Membrane reactors; Membranes, Artificial; Models, Theoretical; Natural energy; Other wastewaters; Pollution; Sewage - chemistry; Uncertainty; Waste Water; Wastewaters; Water Purification - economics; Water Purification - instrumentation; Water Purification - methods; Water treatment; Water treatment and pollution; Water treatment; Alternative energy; Ecobalance; Energy recovery; Biogas; Sustainable development; Anaerobic digestion; Biological purification; Domestic waste water; Membrane reactor; Bioreactor; Renewable energy; Anaerobe; Environment impact; Bioenergy; Waste water purification; Resource management; Environmental protection
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es5006169

The objective of this study was to evaluate emerging anaerobic membrane bioreactor (AnMBR) technology in comparison with conventional wastewater energy recovery technologies. Wastewater treatment process modeling and systems analyses were combined to evaluate the conditions under which AnMBR may produce more net energy and have lower life cycle environmental emissions than high rate activated sludge with anaerobic digestion (HRAS+AD), conventional activated sludge with anaerobic digestion (CAS+AD), and an aerobic membrane bioreactor with anaerobic digestion (AeMBR+AD). For medium strength domestic wastewater treatment under baseline assumptions at 15 °C, AnMBR recovered 49% more energy as biogas than HRAS+AD, the most energy positive conventional technology considered, but had significantly higher energy demands and environmental emissions. Global warming impacts associated with AnMBR were largely due to emissions of effluent dissolved methane. For high strength domestic wastewater treatment, AnMBR recovered 15% more net energy than HRAS+AD, and the environmental emissions gap between the two systems was reduced. Future developments of AnMBR technology in low energy fouling control, increased flux, and management of effluent methane emissions would make AnMBR competitive with HRAS+AD. Rapid advancements in AnMBR technology must continue to achieve its full economic and environmental potential as an energy recovery strategy for domestic wastewater.