title: Scale-up of phosphate remobilization from sewage sludge in a microbial fuel cell.
abstract: Phosphate remobilization from digested sewage sludge containing iron phosphate was scaled-up in a microbial fuel cell (MFC). A 3litre triple chambered MFC was constructed. This reactor was operated as a microbial fuel cell and later as a microbial electrolysis cell to accelerate cathodic phosphate remobilization. Applying an additional voltage and exceeding native MFC power accelerated chemical base formation and the related phosphate remobilization rate. The electrolysis approach was extended using a platinum-RVC cathode. The pH rose to 12.6 and phosphate was recovered by 67% in 26h. This was significantly faster than using microbial fuel cell conditions. Shrinking core modelling particle fluid kinetics showed that the reaction resistance has to move inside the sewage sludge particle for considerable rate enhancement. Remobilized phosphate was subsequently precipitated as struvite and inductively coupled plasma mass spectrometry indicated low levels of cadmium, lead, and other metals as required by law for recycling fertilizers.
authors.affiliation: Institute of Life Technologies, HES-SO Valais, University of Applied Sciences Western Switzerland, Route du Rawyl 64, CH-1950 Sion, Switzerland.
authors.forename: Manuel
authors.initials: M
authors.lastname: Happe
authors.affiliation: Institute of Life Technologies, HES-SO Valais, University of Applied Sciences Western Switzerland, Route du Rawyl 64, CH-1950 Sion, Switzerland.
authors.forename: Marc
authors.initials: M
authors.lastname: Sugnaux
authors.affiliation: Systems Engineering, HES-SO Valais, University of Applied Sciences Western Switzerland, Route du Rawyl 47, CH-1950 Sion, Switzerland.
authors.forename: Christian Pierre
authors.initials: CP
authors.lastname: Cachelin
authors.affiliation: Labor Spiez, Federal Office for Civil Protection, Laboratory for Environmental Testing, Austrasse, CH-3700 Spiez, Switzerland.
authors.forename: Marc
authors.initials: M
authors.lastname: Stauffer
authors.affiliation: Institute of Life Technologies, HES-SO Valais, University of Applied Sciences Western Switzerland, Route du Rawyl 64, CH-1950 Sion, Switzerland.
authors.forename: Géraldine
authors.initials: G
authors.lastname: Zufferey
authors.affiliation: Lonza Ltd., Rottenstrasse 6, CH-3930 Visp, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kahoun
authors.affiliation: Systems Engineering, HES-SO Valais, University of Applied Sciences Western Switzerland, Route du Rawyl 47, CH-1950 Sion, Switzerland.
authors.forename: Paul-André
authors.initials: PA
authors.lastname: Salamin
authors.affiliation: Swiss Federal Institute of Aquatic Science and Technology, EAWAG, P.O. Box 611, CH-8600 Dübendorf, Switzerland; Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, CH-8092 Zurich, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Egli
authors.affiliation: Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, Station 6, CH-1015 Lausanne, Switzerland.
authors.forename: Christos
authors.initials: C
authors.lastname: Comninellis
authors.affiliation: Institute of Life Technologies, HES-SO Valais, University of Applied Sciences Western Switzerland, Route du Rawyl 64, CH-1950 Sion, Switzerland.
authors.forename: Alain-François
authors.initials: AF
authors.lastname: Grogg
authors.affiliation: Institute of Life Technologies, HES-SO Valais, University of Applied Sciences Western Switzerland, Route du Rawyl 64, CH-1950 Sion, Switzerland. Electronic address: fabian.fischer@hevs.ch.
authors.forename: Fabian
authors.initials: F
authors.lastname: Fischer
mesh_terms: D001674:Bioelectric Energy Sources; D004566:Electrodes; D004572:Electrolysis; D004926:Escherichia coli / Q000378:metabolism; D005308:Fertilizers; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008670:Metals; D010710:Phosphates / Q000737:chemistry*; D012037:Refuse Disposal / Q000379:methods*; D012722:Sewage / Q000737:chemistry*; D000069877:Struvite / Q000737:chemistry; D062065:Wastewater
chemical_list: D005308:Fertilizers; D008670:Metals; D010710:Phosphates; D012722:Sewage; D000069877:Struvite; D062065:Wastewater
keywords: Microbial electrolysis cell; Microbial fuel cell; Phosphate; Sewage sludge; Struvite