The effect of feed composition on anaerobic co-digestion of animal-processing by-products

• Published in: Journal of environmental management 2018-06, Vol.216, p.105-110
• Main Authors: Hidalgo, D., Martín-Marroquín, J.M., Corona, F.
• Format: Article
• Language: English
• Subjects: Anaerobic digestion; Anaerobiosis; Animal by-products; Animals; Bioreactors; Glycerol; Manure; Methane; Pig manure; Swine; Waste valorization
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2017.06.033

Four streams and their mixtures have been considered for anaerobic co-digestion, all of them generated during pig carcasses processing or in related industrial activities: meat flour (MF), process water (PW), pig manure (PM) and glycerin (GL). Biochemical methane potential assays were conducted at 37 °C to evaluate the effects of the substrate mix ratio on methane generation and process behavior. The results show that the co-digestion of these products favors the anaerobic fermentation process when limiting the amount of meat flour in the mixture to co-digest, which should not exceed 10%. The ratio of other tested substrates is less critical, because different mixtures reach similar values of methane generation. The presence in the mixture of process water contributes to a quick start of the digester, something very interesting when operating an industrial reactor. The analysis of the fraction digested reveals that the four analyzed streams can be, a priori, suitable for agronomic valorization once digested. •A sustainable alternative to the management of pig carcasses and manure is proposed.•Co-digestion of animal processing by-products favors the anaerobic fermentation process.•The amount of meat flour in the mixture to co-digest is a limiting factor.•The presence of process water contributes to a quick start of the digester.