Saponification pretreatment and solids recirculation as a new anaerobic process for the treatment of slaughterhouse waste

• Published in: Bioresource technology 2013-03, Vol.131, p.460-467
• Main Authors: Affes, R., Palatsi, J., Flotats, X., Carrère, H., Steyer, J.P., Battimelli, A.
• Format: Article
• Language: English
• Subjects: Abattoirs - instrumentation; Acclimation; adaptation; Agronomy. Soil science and plant productions; Alkalies - chemistry; Alkaline hydrolysis; Anaerobic digestion; Anaerobic processes; Animal waste; Bacteria, Anaerobic - metabolism; bioavailability; Biological and medical sciences; Biological treatment of sewage sludges and wastes; Biotechnology; Desenvolupament humà i sostenible; emulsifying; Environment and pollution; Environmental Sciences; Esterification; Fats - chemistry; Fats - metabolism; Feeding; Food industries; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Gestió de residus; Hot Temperature; Industrial applications and implications. Economical aspects; Industrial Waste - prevention & control; Life Sciences; Long chain fatty acids; Methods. Procedures. Technologies; Microbial engineering. Fermentation and microbial culture technology; Microorganisms; Política i gestió ambiental; Pretreatment; Reactors; Refuse Disposal - methods; Residus animals; saponification; Sewage - microbiology; Slaughterhouse waste; slaughterhouse wastes; Slaughterhouses; solid wastes; Solids recirculation; Use and upgrading of agricultural and food by-products. Biotechnology; Use of agricultural and forest wastes. Biomass use, bioconversion; waste treatment; Wastes; Àrees temàtiques de la UPC
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2012.12.187

► Novel anaerobic digestion systems for the treatment of fatty waste are proposed. ► Substrate saponification and solids recirculation both benefits the process. ► Saponification enhances emulsification and bioavailability of fatty residues. ► Recirculation minimizes substrate/biomass wash-out and induces microbial adaptation. Different configurations of anaerobic process, adapted to the treatment of solid slaughterhouse fatty waste, were proposed and evaluated in this study. The tested configurations are based on the combination of anaerobic digestion with/without waste saponification pretreatment (70°C during 60min) and with/without recirculation of the digestate solid fraction (ratio=20% w/w). After an acclimation period of substrate pulses-feeding cycles, the reactors were operated in a semi-continuous feeding mode, increasing organic loading rates along experimental time. The degradation of the raw substrate was shown to be the bottleneck of the whole process, obtaining the best performance and process yields in the reactor equipped with waste pretreatment and solids recirculation. Saponification promoted the emulsification and bioavailability of solid fatty residues, while recirculation of solids minimized the substrate/biomass wash-out and induced microbial adaptation to the treatment of fatty substrates.