title: Characterisation of the biodegradability of post-treated digestates via the chemical accessibility and complexity of organic matter.
abstract: The stability of digestate organic matter is a key parameter for its use in agriculture. Here, the organic matter stability was compared between 14 post-treated digestates and the relationship between organic matter complexity and biodegradability was highlighted. Respirometric activity and CH4yields in batch tests showed a positive linear correlation between both types of biodegradability (R2=0.8). The accessibility and complexity of organic matter were assessed using chemical extractions combined with fluorescence spectroscopy, and biodegradability was mostly anti-correlated with complexity of organic matter. Post-treatments presented a significant effect on the biodegradability and complexity of organic matter. Biodegradability was low for composted digestates which comprised slowly accessible complex molecules. Inversely, solid fractions obtained after phase separation contained a substantial part of remaining biodegradable organic matter with a significant easily accessible fraction comprising simpler molecules. Understanding the effect of post-treatment on the biodegradability of digestates should help to optimize their valorization.
authors.affiliation: LBE, INRA, 102 Avenue des Etangs, Narbonne F-11100, France.
authors.forename: Géraldine
authors.initials: G
authors.lastname: Maynaud
authors.affiliation: Irstea, UR OPAALE, 17 avenue de Cucillé, CS64427, Rennes F-35044, France; Université Bretagne Loire, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Druilhe
authors.affiliation: Irstea, UR OPAALE, 17 avenue de Cucillé, CS64427, Rennes F-35044, France; Université Bretagne Loire, France.
authors.forename: Mylène
authors.initials: M
authors.lastname: Daumoin
authors.affiliation: LBE, INRA, 102 Avenue des Etangs, Narbonne F-11100, France.
authors.forename: Julie
authors.initials: J
authors.lastname: Jimenez
authors.affiliation: LBE, INRA, 102 Avenue des Etangs, Narbonne F-11100, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Patureau
authors.affiliation: LBE, INRA, 102 Avenue des Etangs, Narbonne F-11100, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Torrijos
authors.affiliation: Irstea, UR OPAALE, 17 avenue de Cucillé, CS64427, Rennes F-35044, France; Université Bretagne Loire, France.
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Pourcher
authors.affiliation: LBE, INRA, 102 Avenue des Etangs, Narbonne F-11100, France. Electronic address: nathalie.wery@inra.fr.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Wéry
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D057919:Biological Oxygen Demand Analysis; D007700:Kinetics; D009930:Organic Chemicals / Q000737:chemistry*; D025341:Principal Component Analysis; D012037:Refuse Disposal; D012722:Sewage / Q000737:chemistry; D012987:Soil; D014835:Volatilization
chemical_list: D009930:Organic Chemicals; D012722:Sewage; D012987:Soil
keywords: Anaerobic digestion; Biodegradability; Complexity; Digestate; Respirometry