Sustainability assessment of a sequential anaerobic-algal membrane bioreactor for wastewater reuse

Reused wastewater is a robust alternative to freshwater resource depletion. While high-level treatment is required, the United Nation's Sustainable Development Goals promote the recovery of resources such as energy and nutrients. Advanced wastewater treatment technologies able to recover water, energy and nutrients have been previously assessed from a life cycle perspective. This study evaluates a sequential Anaerobic-Algal Membrane Bioreactor (A(2)MBR) as an alternative reuse technology. Following the Integrative Concept of Sustainability framework, 19 indicators evaluated the sustainability of an A(2)MBR in Central Chile as an implementation example. Additional water supply and nutrient recovery in biosolids are key environmental benefits for the case-study. Global warming, eutrophication, and acidification potential indicators improved in the A(2)MBR system vs the status quo. On-site treatment costs seemed competitive compared to existing alternatives to water supply (i.e., desalination) while reducing the net demand for fossil fuels due to waste transportation. Pilot demonstrations and a long-term social assessment are needed to validate the identified sustainability benefits.