Chemical characterization of municipal wastewater sludges produced by two-phase anaerobic digestion for biogas production.
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.
Francioso
Ornella
O
Dipartimento di Scienze e Tecnologie Agroambientali, V.le Fanin 40, 40127 Bologna, Italy. ornella.francioso@unibo.it
Rodriguez-Estrada
Maria Teresa
MT
Montecchio
Daniela
D
Salomoni
Cesare
C
Caputo
Armando
A
Palenzona
Domenico
D
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
D056804:Biofuels; D002247:Carbon Isotopes; D012722:Sewage