title: Chemical characterization of municipal wastewater sludges produced by two-phase anaerobic digestion for biogas production.
abstract: In the present study, the chemical features of municipal wastewater sludges treated in two-phase separate digesters (one for acetogenesis and the other one for methanogenesis), were characterized by using chemical analysis, stable carbon isotope ratios (delta(13)C), HS-SPME-GC-MS, TG-DTA analysis and DRIFT spectroscopy. The results obtained showed that sludges from acetogenesis and methanogenesis differed from each other, as well as from influent raw sludges. Both processes exhibited a diverse chemical pattern in term of VFA and VOC. Additional variations were observed for delta(13)C values that changed from acetogenesis to methanogenesis, as a consequence of fermentation processes that led to a greater fractionation of (12)C with respect to the (13)C isotope. Similarly, the thermal profiles of acetogenesis and methanogenesis sludges greatly differed in terms of heat combustion produced. These changes were also supported by higher lipid content (probably fatty acids) in acetogenesis than in methanogenesis, as also shown by DRIFT spectroscopy.
authors.affiliation: Dipartimento di Scienze e Tecnologie Agroambientali, V.le Fanin 40, 40127 Bologna, Italy. ornella.francioso@unibo.it
authors.forename: Ornella
authors.initials: O
authors.lastname: Francioso
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Rodriguez-Estrada
authors.forename: Daniela
authors.initials: D
authors.lastname: Montecchio
authors.forename: Cesare
authors.initials: C
authors.lastname: Salomoni
authors.forename: Armando
authors.initials: A
authors.lastname: Caputo
authors.forename: Domenico
authors.initials: D
authors.lastname: Palenzona
mesh_terms: D000693:Anaerobiosis; D056804:Biofuels; D019149:Bioreactors; D002247:Carbon Isotopes / Q000737:chemistry; D002947:Cities; D004867:Equipment Design; D005285:Fermentation; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006358:Hot Temperature; D013058:Mass Spectrometry / Q000379:methods; D012722:Sewage / Q000737:chemistry*; D013055:Spectrophotometry, Infrared / Q000379:methods; D013696:Temperature; D014865:Waste Disposal, Fluid / Q000379:methods*; D018508:Water Purification / Q000379:methods
chemical_list: D056804:Biofuels; D002247:Carbon Isotopes; D012722:Sewage