title: Effect of ultrasonic pretreatment on biomethane potential of two-phase olive mill solid waste: kinetic approach and process performance.
abstract: The effect of ultrasound (US) pretreatment on two-phase olive mil solid waste (OMSW) composition and subsequent anaerobic biodegradation was evaluated by chemical oxygen demand solubilization and biochemical methane potential (BMP) tests. OMSW was ultrasonically pretreated at a power of 200 W and frequency of 24 kHz for time periods of 20, 40, 60, 90, 120, and 180 minutes, corresponding to specific energies of 11367, 21121, 34072, 51284, 68557, and 106003 kJ/kg total solids, respectively. In order to evaluate the US pretreatment, a low, medium, and high exposure time, that is, 20, 90, and 180 min, were selected for BMP tests. Methane yields of 311 ± 15, 393 ± 14, and 370 ± 20 mL CH₄/g VSadded (VS: volatile solids) were obtained for 20, 90, and 180 minutes, respectively, while the untreated OMSW gave 373 ± 4 mL CH₄/g VSadded. From a kinetic point of view, the BMP tests showed a first exponential stage and a second sigmoidal stage. In the first stage, the kinetic constant obtained for US pretreated OMSW at 20 minutes was 46% higher than those achieved for the pretreated OMSW at 90 and 180 minutes and 48% higher than that for untreated OMSW. The maximum methane production rate achieved was 12% higher than that obtained for untreated OMSW.
authors.affiliation: Instituto de la Grasa (CSIC), Avenida Padre García Tejero, 4.41012 Sevilla, Spain.
authors.forename: B
authors.initials: B
authors.lastname: Rincón
authors.affiliation: Instituto de la Grasa (CSIC), Avenida Padre García Tejero, 4.41012 Sevilla, Spain.
authors.forename: L
authors.initials: L
authors.lastname: Bujalance
authors.affiliation: Instituto de la Grasa (CSIC), Avenida Padre García Tejero, 4.41012 Sevilla, Spain.
authors.forename: F G
authors.initials: FG
authors.lastname: Fermoso
authors.affiliation: Departamento de Ingeniería Química y Química Inorgánica, Facultad de Ciencias, Universidad de Córdoba, Campus Universitario de Rabanales, Edificio C-3, Carretera Madrid-Cádiz, km 396, 14071 Córdoba, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Martín
authors.affiliation: Instituto de la Grasa (CSIC), Avenida Padre García Tejero, 4.41012 Sevilla, Spain.
authors.forename: R
authors.identifier: 0000-0002-3699-7223
authors.initials: R
authors.lastname: Borja
mesh_terms: D001421:Bacteria, Anaerobic / Q000378:metabolism*; D001673:Biodegradation, Environmental; D056804:Biofuels / Q000032:analysis*; D057919:Biological Oxygen Demand Analysis; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008697:Methane / Q000096:biosynthesis*; D031658:Olea; D012037:Refuse Disposal / Q000379:methods*; D014465:Ultrasonics / Q000379:methods*
chemical_list: D056804:Biofuels; D008697:Methane