title: Production of carboxylates from high rate activated sludge through fermentation.
abstract: The aim of this work was to study the key parameters affecting fermentation of high rate activated A-sludge to carboxylates, including pH, temperature, inoculum, sludge composition and iron content. The maximum volatile fatty acids production was 141mgCg(-1) VSSfed, at pH 7. Subsequently the potential for carboxylate and methane production for A-sludge from four different plants at pH 7 and 35°C were compared. Initial BOD of the sludge appeared to be key determining carboxylate yield from A-sludge. Whereas methanogenesis could be correlated linearly to the quantity of ferric used for coagulation, fermentation did not show a dependency on iron presence. This difference may enable a strategy whereby A-stage sludge is separated to achieve fermentation, and iron dosing for phosphate removal is only implemented at the B-stage.
authors.affiliation: Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, B-9000 Ghent, Belgium. Electronic address: cristina.cagnetta@ugent.be.
authors.forename: C
authors.initials: C
authors.lastname: Cagnetta
authors.affiliation: Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, B-9000 Ghent, Belgium. Electronic address: m.coma@bath.ac.uk.
authors.forename: M
authors.initials: M
authors.lastname: Coma
authors.affiliation: Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, B-9000 Ghent, Belgium; Research Group of Sustainable Energy, Air and Water Technology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium.
authors.forename: S E
authors.initials: SE
authors.lastname: Vlaeminck
authors.affiliation: Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, B-9000 Ghent, Belgium. Electronic address: Korneel.rabaey@ugent.be.
authors.forename: K
authors.initials: K
authors.lastname: Rabaey
mesh_terms: D019149:Bioreactors; D002264:Carboxylic Acids / Q000737:chemistry / Q000378:metabolism; D005232:Fatty Acids, Volatile / Q000737:chemistry / Q000378:metabolism; D005285:Fermentation; D008697:Methane / Q000737:chemistry / Q000378:metabolism; D012722:Sewage / Q000737:chemistry*
chemical_list: D002264:Carboxylic Acids; D005232:Fatty Acids, Volatile; D012722:Sewage; D008697:Methane
keywords: A-sludge; AB process; Anaerobic digestion; Iron; Volatile fatty acids (VFA)