title: Conversion of sewage sludge to commodity chemicals via syngas fermentation.
abstract: Gasification of sewage sludge allows the recovery of energy, and produces a mix of CO, CO₂and H₂called synthesis gas (or syngas), which can be fermented by acetogenic bacteria to added-value products. This work presents the conversion of syngas to organic acids and alcohols using both pure and mixed cultures. Pure culture kinetic experiments with Clostridium carboxidivorans P7 resulted in the production of high concentrations of acetate (454 mgC/L) and ethanol (167 mgC/L). The pH was the main factor driving solventogenesis, with about 50% of the products in the form of alcohols at pH 5. Conversely, laboratory-scale experiments using a carboxydotrophic mixed culture of the genus Clostridium enriched from anaerobic digester sludge of a municipal wastewater treatment plant was capable of producing mainly butyrate, with maximum concentration of 1,184 mgC/L.
authors.affiliation: LEQUIA, Institute of the Environment, University of Girona, Campus de Montilivi, Girona E-17071, Catalonia, Spain E-mail: ramon.ganigue@lequia.udg.cat.
authors.forename: Ramon
authors.initials: R
authors.lastname: Ganigué
authors.affiliation: LEQUIA, Institute of the Environment, University of Girona, Campus de Montilivi, Girona E-17071, Catalonia, Spain E-mail: ramon.ganigue@lequia.udg.cat; Institute of Aquatic Ecology (IEA), University of Girona, Campus de Montilivi, Girona E-17071, Catalonia, Spain.
authors.forename: Sara
authors.initials: S
authors.lastname: Ramió-Pujol
authors.affiliation: LEQUIA, Institute of the Environment, University of Girona, Campus de Montilivi, Girona E-17071, Catalonia, Spain E-mail: ramon.ganigue@lequia.udg.cat.
authors.forename: Patricia
authors.initials: P
authors.lastname: Sánchez
authors.affiliation: Institute of Aquatic Ecology (IEA), University of Girona, Campus de Montilivi, Girona E-17071, Catalonia, Spain.
authors.forename: Lluís
authors.initials: L
authors.lastname: Bañeras
authors.affiliation: LEQUIA, Institute of the Environment, University of Girona, Campus de Montilivi, Girona E-17071, Catalonia, Spain E-mail: ramon.ganigue@lequia.udg.cat.
authors.forename: Jesús
authors.initials: J
authors.lastname: Colprim
mesh_terms: D000085:Acetates; D000438:Alcohols; D019149:Bioreactors; D003013:Clostridium / Q000378:metabolism*; D005285:Fermentation; D012722:Sewage / Q000382:microbiology*
chemical_list: D000085:Acetates; D000438:Alcohols; D012722:Sewage