title: Co-digestion of food waste in a municipal wastewater treatment plant: Comparison of batch tests and full-scale experiences.
abstract: The effects of co-digestion of food waste in a municipal wastewater treatment plant (WWTP) were studied in batch tests. The results obtained were compared with the mass balance of a digester at a full-scale WWTP for a one-year period without and with the addition of co-substrate. The specific methane yield calculated from the balance was 18% higher than the one in the batch tests, suggesting a stimulation of methane generation by co-digestion. It was hypothesized that this increase was caused by shifting the C/N ratio of raw sludge (8.8) to a more favourable ratio of the added food waste (17.7). In addition, potential benefits by adding food waste for energy autarky was investigated. While just 25% of the total energy demand of the plant could be recovered by biogas generation when no co-substrate was fed, this percentage has more than doubled when food waste was added at a ratio of 10% (w/w).
authors.affiliation: Chair of Urban Water Systems Engineering, Technische Universität München, Am Coulombwall 8, 85748 Garching, Germany. Electronic address: k.koch@tum.de.
authors.forename: Konrad
authors.initials: K
authors.lastname: Koch
authors.affiliation: Chair of Urban Water Systems Engineering, Technische Universität München, Am Coulombwall 8, 85748 Garching, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Plabst
authors.affiliation: Wastewater Treatment Plant Garching an der Alz, Berndlmühle 34, 84518 Garching an der Alz, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Schmidt
authors.affiliation: Chair of Urban Water Systems Engineering, Technische Universität München, Am Coulombwall 8, 85748 Garching, Germany.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Helmreich
authors.affiliation: Chair of Urban Water Systems Engineering, Technische Universität München, Am Coulombwall 8, 85748 Garching, Germany.
authors.forename: Jörg E
authors.initials: JE
authors.lastname: Drewes
mesh_terms: D056804:Biofuels / Q000032:analysis*; D019149:Bioreactors; D005735:Garbage; D008697:Methane / Q000378:metabolism*; D012037:Refuse Disposal / Q000379:methods*; D018505:Waste Management; D062065:Wastewater / Q000032:analysis*
chemical_list: D056804:Biofuels; D008697:Methane; D062065:Wastewater
keywords: Co-digestion; Energy autarky; Food waste; Sewage sludge; Synergistic effect