title: Life cycle assessment of constructed wetland systems for wastewater treatment coupled with microbial fuel cells.
abstract: The aim of this study was to assess the environmental impact of microbial fuel cells (MFCs) implemented in constructed wetlands (CWs). To this aim a life cycle assessment (LCA) was carried out comparing three scenarios: 1) a conventional CW system (without MFC implementation); 2) a CW system coupled with a gravel-based anode MFC, and 3) a CW system coupled with a graphite-based anode MFC. All systems served a population equivalent of 1500 p.e. They were designed to meet the same effluent quality. Since MFCs implemented in CWs improve treatment efficiency, the CWs coupled with MFCs had lower specific area requirement compared to the conventional CW system. The functional unit was 1m3of wastewater. The LCA was performed with the software SimaPro® 8, using the CML-IA baseline method. The three scenarios considered showed similar environmental performance in all the categories considered, with the exception of Abiotic Depletion Potential. In this impact category, the potential environmental impact of the CW system coupled with a gravel-based anode MFC was around 2 times higher than that generated by the conventional CW system and the CW system coupled with a graphite-based anode MFC. It was attributed to the large amount of less environmentally friendly materials (e.g. metals, graphite) for MFCs implementation, especially in the case of gravel-based anode MFCs. Therefore, the CW system coupled with graphite-based anode MFC appeared as the most environmentally friendly solution which can replace conventional CWs reducing system footprint by up to 20%. An economic assessment showed that this system was around 1.5 times more expensive than the conventional CW system.
authors.affiliation: GEMMA - Group of Environmental Engineering and Microbiology, Department of Civil and Environmental Engineering, Universitat Politècnica de Catalunya-BarcelonaTech, c/ Jordi Girona, 1-3, Building D1, E-08034 Barcelona, Spain.
authors.forename: Clara
authors.initials: C
authors.lastname: Corbella
authors.affiliation: GEMMA - Group of Environmental Engineering and Microbiology, Department of Civil and Environmental Engineering, Universitat Politècnica de Catalunya-BarcelonaTech, c/ Jordi Girona, 1-3, Building D1, E-08034 Barcelona, Spain.
authors.forename: Jaume
authors.initials: J
authors.lastname: Puigagut
authors.affiliation: GEMMA - Group of Environmental Engineering and Microbiology, Department of Civil and Environmental Engineering, Universitat Politècnica de Catalunya-BarcelonaTech, c/ Jordi Girona, 1-3, Building D1, E-08034 Barcelona, Spain. Electronic address: marianna.garfi@upc.edu.
authors.forename: Marianna
authors.initials: M
authors.lastname: Garfí
mesh_terms: D001674:Bioelectric Energy Sources; D004566:Electrodes; D006108:Graphite; D062065:Wastewater; D018508:Water Purification / Q000379:methods*; D053833:Wetlands
chemical_list: D006108:Graphite; D062065:Wastewater
keywords: Constructed wetland; Decentralised wastewater treatment system; Environmental impact assessment; Life cycle assessment; Microbial fuel cells; Wastewater treatment