title: The importance of aeration mode and flowrate in the determination of the biological activity and stability of organic wastes by respiration indices.
abstract: The aim of this study was to assess the effect of different air flowrates and different aeration modes on the respiration activity of three organic substrates of different stability degree: (i) a constant flowrate and (ii) a continuously adjusted air flowrate that optimized the oxygen uptake rate (OUR). Above 20L air kg(-1)DMh(-1), at the constant flow regime, the resulting dynamic respiration index at 24h (DRI24) and the cumulative respiration at four days (AT4) were statistically similar. At the OUR based aeration regime, the DRI24 and AT4 were statistically similar at all initial flowrates tested. Above a minimum threshold, cumulative air flow of around 3000Lairkg(-1) DM during a 5day period, the respiration activity was similar, particularly for the two less active substrates. This study highlights the importance of selecting the aeration to obtain reliable measures of biological activity and stability in organic wastes.
authors.affiliation: Composting Research Group (GICOM), Dept. of Chemical Engineering, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
authors.forename: Natividad
authors.initials: N
authors.lastname: Almeira
authors.affiliation: Composting Research Group (GICOM), Dept. of Chemical Engineering, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Komilis
authors.affiliation: Composting Research Group (GICOM), Dept. of Chemical Engineering, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
authors.forename: Raquel
authors.initials: R
authors.lastname: Barrena
authors.affiliation: Composting Research Group (GICOM), Dept. of Chemical Engineering, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
authors.forename: Teresa
authors.initials: T
authors.lastname: Gea
authors.affiliation: Composting Research Group (GICOM), Dept. of Chemical Engineering, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain. Electronic address: antoni.sanchez@uab.cat.
authors.forename: Antoni
authors.initials: A
authors.lastname: Sánchez
mesh_terms: D019149:Bioreactors; D010100:Oxygen / Q000008:administration & dosage* / Q000378:metabolism*; D018505:Waste Management / Q000379:methods*
chemical_list: D010100:Oxygen
keywords: Aeration mode; Biological stability; Dynamic respiration index; Oxygen uptake rate; Stability