title: Empirical characterisation and mathematical modelling of settlement in composting batch reactors.
abstract: The settlement of organic matter during composting was measured at different levels during the active biodegradation phase in forced-aerated static reactors loaded with different mixtures of organic wastes. The temperature evolution and the concentration of oxygen and carbon dioxide were also recorded in the exhaust gases. Two two-parameter equations and their generalised three-parameter form were fitted to the experimental data and their capability to predict settlement as a function of time was discussed. The settlement field inside the reactors was successfully described with a linear profile. At any given time and vertical position, mass settlement was proportional to the initial height after reactor loading. Furthermore, a relationship linking settlement to biological activity was also proposed. Under all tested experimental conditions, settlement showed a clear correlation with the cumulative oxygen consumption that was modelled with a three parameter equation.
authors.affiliation: Dept. of Computing and Industrial Engineering, Universitat de Lleida, Avgda. Jaume II 69, E-25001 Lleida, Spain. jilla@macs.udl.cat
authors.forename: Josep
authors.initials: J
authors.lastname: Illa
authors.forename: Francesc X
authors.initials: FX
authors.lastname: Prenafeta-Boldú
authors.forename: August
authors.initials: A
authors.lastname: Bonmatí
authors.forename: Xavier
authors.initials: X
authors.lastname: Flotats
mesh_terms: D019149:Bioreactors / Q000382:microbiology*; D003198:Computer Simulation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008954:Models, Biological; D008956:Models, Chemical; D009391:Nephelometry and Turbidimetry / Q000379:methods*; D009930:Organic Chemicals / Q000737:chemistry* / Q000378:metabolism*; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology
chemical_list: D009930:Organic Chemicals; D012987:Soil