title: Integrated conversion of food waste diluted with sewage into volatile fatty acids through fermentation and electricity through a fuel cell.
abstract: In this study, domestic wastewater was given a second life as dilution medium for concentrated organic waste streams, in particular artificial food waste. A two-step continuous process with first volatile fatty acid (VFA)/hydrogen production and second electricity production in microbial fuel cells (MFCs) was employed. For primary treatment, bioreactors were optimized to produce hydrogen and VFAs. Hydrolysis of the solids and formation of fermentation products and hydrogen was monitored. In the second step, MFCs were operated batch-wise using the effluent rich in VFAs specifically acetic acid from the continuous reactor of the first step. The combined system was able to reduce the chemical oxygen demand load by 90%. The concentration of VFAs was also monitored regularly in the MFCs and showed a decreasing trend over time. Further, the anode potential changed from -500 to OmV vs. Ag/AgCl when the VFAs (especially acetate) were depleted in the system. On feeding the system again with the effluent, the anode potential recovered back to -500 mV vs. Ag/AgCl. Thus, the overall aim of converting chemical energy into electrical energy was achieved with a columbic efficiency of 46% generating 65.33 mA/m2 at a specific cell potential of 148 mV.
authors.affiliation: Separation and Conversion Technology, VITO-Flemish Institute for Technological Research, Boeretang 200, 2400 Mol, Belgium. deepak.pant@vito.be
authors.forename: Deepak
authors.initials: D
authors.lastname: Pant
authors.affiliation: Separation and Conversion Technology, VITO-Flemish Institute for Technological Research, Boeretang 200, 2400 Mol, Belgium.
authors.forename: Doga
authors.initials: D
authors.lastname: Arslan
authors.affiliation: Separation and Conversion Technology, VITO-Flemish Institute for Technological Research, Boeretang 200, 2400 Mol, Belgium.
authors.forename: Gilbert
authors.initials: G
authors.lastname: Van Bogaert
authors.affiliation: Separation and Conversion Technology, VITO-Flemish Institute for Technological Research, Boeretang 200, 2400 Mol, Belgium.
authors.forename: Yolanda Alvarez
authors.initials: YA
authors.lastname: Gallego
authors.affiliation: Separation and Conversion Technology, VITO-Flemish Institute for Technological Research, Boeretang 200, 2400 Mol, Belgium.
authors.forename: Heleen
authors.initials: H
authors.lastname: De Wever
authors.affiliation: Separation and Conversion Technology, VITO-Flemish Institute for Technological Research, Boeretang 200, 2400 Mol, Belgium.
authors.forename: Ludo
authors.initials: L
authors.lastname: Diels
authors.affiliation: Separation and Conversion Technology, VITO-Flemish Institute for Technological Research, Boeretang 200, 2400 Mol, Belgium.
authors.forename: Karolien
authors.initials: K
authors.lastname: Vanbroekhoven
mesh_terms: D001674:Bioelectric Energy Sources; D019149:Bioreactors; D004560:Electricity; D055664:Electrochemical Techniques; D005232:Fatty Acids, Volatile / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism*; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D012722:Sewage; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*
chemical_list: D005232:Fatty Acids, Volatile; D012722:Sewage