Life Cycle and Economic Assessments of Key Emerging Energy Efficient Wastewater Treatment Processes for Climate Change Adaptation

New emerging wastewater treatment technologies like bioelectrochemical systems (BESs) and membrane bioreactors (MBRs) have been introduced in wastewater treatment plants (WWTPs) for producing energy and treating urban wastewater. This study compares WWTPs that combine new emerging technologies of membrane bioreactors (MBRs), microbial fuel cells (MFCs), and microbial electrolysis (MEC) with the conventional techniques (anaerobic, anoxic, and oxic, A 2 O). The environmental and economic impacts of the combined emerging treatment technologies are evaluated. Life cycle assessment (LCA) and economic assessment of the total cost considering both capital and operating cost are performed to evaluate the environmental and economic impacts, respectively. The environmental impact evaluation demonstrated that A 2 O + MBR and A 2 O + MFC processes are the most environmentally friendly processes in the construction and operation stages, respectively. Detailed analyses of the dominant environmental impact categories showed that the total volume for the construction stage, the effluent quality, and methane emission for the operation stage are important parameters. The results of economic impact showed that A 2 O and A 2 O + MFC processes have the lowest capital cost and operational cost, respectively. Furthermore, it can be inferred that A 2 O + MFC is the most economic process based on total economic impact, which included both the capital and the operational cost over 20 years. The proposed method provided guidance on the use of economical and environmentally friendly emerging techniques in WWTPs.