title: Three-dimensional X-ray microcomputed tomography of carbonates and biofilm on operated cathode in single chamber microbial fuel cell.
abstract: Power output limitation is one of the main concerns that need to be addressed for full-scale applications of the microbial fuel cell technology. Fouling and biofilm growth on the cathode of single chamber microbial fuel cells (SCMFC) affects their performance in long-term operation with wastewater. In this study, the authors report the power output and cathode polarization curves of a membraneless SCMFC, fed with raw primary wastewater and sodium acetate for over 6 months. At the end of the experiment, the whole cathode surface is analyzed through X-ray microcomputed tomography (microCT), scanning electron microscopy, and energy-dispersive X-ray spectroscopy (EDX) to characterize the fouling layer and the biofilm. EDX shows the distribution of Ca, Na, K, P, S, and other elements on the two faces of the cathode. Na-carbonates and Ca-carbonates are predominant on the air (outer) side and the water (inner) side, respectively. The three-dimensional reconstruction by X-ray microCT shows biofilm spots unevenly distributed above the Ca-carbonate layer on the inner (water) side of the cathode. These results indicate that carbonates layer, rather than biofilm, might lower the oxygen reduction reaction rate at the cathode during long-term SCMFC operation.
authors.affiliation: Department of Engineering and Applied Sciences, University of Bergamo, Viale Marconi 5, 24044 Dalmine, Bergamo, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Santini
authors.affiliation: Department of Energy, Politecnico di Milano, Via Lambruschini 4, 20156 Milan, Italy.
authors.forename: Manfredo
authors.initials: M
authors.lastname: Guilizzoni
authors.affiliation: School of Engineering and Mathematical Sciences, City University London, Northampton Square, London EC1V 0HB, United Kingdom.
authors.forename: Massimo
authors.initials: M
authors.lastname: Lorenzi
authors.affiliation: Department of Chemical and Biological Engineering, Center for Micro-Engineered Materials (CMEM), University of New Mexico, Albuquerque, New Mexico 87131.
authors.forename: Plamen
authors.initials: P
authors.lastname: Atanassov
authors.affiliation: Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, 60 Nanyang Drive, 637551 Singapore, Singapore and School of Biotechnology, Dublin City University, Collins Avenue, Dublin 9, Dublin, Ireland.
authors.forename: Enrico
authors.initials: E
authors.lastname: Marsili
authors.affiliation: Department of Management, Information and Production Engineering, University of Bergamo, Viale Marconi 5, 24044 Dalmine, Bergamo, Italy.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Fest-Santini
authors.affiliation: Sustainable Development and Energy Sources Department, RSE-Ricerca sul Sistema Energetico S.p.A., Via Rubattino 54, 20100 Milan, Italy.
authors.forename: Pierangela
authors.initials: P
authors.lastname: Cristiani
authors.affiliation: Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, 60 Nanyang Drive, 637551 Singapore, Singapore.
authors.forename: Carlo
authors.initials: C
authors.lastname: Santoro
mesh_terms: D001674:Bioelectric Energy Sources; D018441:Biofilms / Q000254:growth & development*; D057219:Biofouling; D002254:Carbonates / Q000032:analysis*; D004560:Electricity; D004566:Electrodes / Q000382:microbiology*; D021621:Imaging, Three-Dimensional; D008855:Microscopy, Electron, Scanning; D010084:Oxidation-Reduction; D013052:Spectrometry, X-Ray Emission; D062065:Wastewater / Q000737:chemistry / Q000382:microbiology; D055114:X-Ray Microtomography
chemical_list: D002254:Carbonates; D062065:Wastewater