Decentralized wastewater treatment with anaerobic membrane bioreactor/UV: Operational performance of a demonstration-scale plant against an aerobic plant and comparative life cycle assessment

A comparative life cycle assessment (LCA) was performed to evaluate the environmental performance of a decentralized anaerobic membrane bioreactor (AnMBR) coupled with UV disinfection technology, and to compare it with a conventional aerobic treatment plant that comprised of oxidation ditch and membrane filtration. The analysis was conducted using the operational data obtained over 2 years from a demonstration scale AnMBR coupled with UV and with a capacity of 50 m 3 per day. Operational data from a conventional aerobic plant that was treating the same wastewater influent as that of the AnMBR was also obtained. The AnMBR/UV achieved similar or outperformed the aerobic plant with more than 97% organic matter removal and more than 7-log removal of Escherichia coli . The projected specific energy consumption of a decentralized AnMBR/UV with capacity of 1000 m 3 per day is lower compared with aerobic technology. There is a positive energy balance achieved by a decentralized AnMBR/UV with 0.29 kWh per m 3 recovered. Midpoint environmental indicators' analysis revealed that the AnMBR/UV has significantly lower environmental impact for climate change compared with the conventional plant (0.2 and 2.6 kg CO2 eq. respectively). Impacts related to toxicity and resource depletion were also lower in the AnMBR/UV. However, the implementation of post treatment to the AnMBR/UV is necessary to potentially alleviate environmental impacts related to freshwater and marine eutrophication due to the presence of nutrients in the final effluent stream.