title: Biodegradation pattern of hydrocarbons from a fuel oil-type complex residue by an emulsifier-producing microbial consortium.
abstract: The biodegradation of a hazardous waste (bilge waste), a fuel oil-type complex residue from normal ship operations, was studied in a batch bioreactor using a microbial consortium in seawater medium. Experiments with initial concentrations of 0.18 and 0.53% (v/v) of bilge waste were carried out. In order to study the biodegradation kinetics, the mass of n-alkanes, resolved hydrocarbons and unresolved complex mixture (UCM) hydrocarbons were assessed by gas chromatography (GC). Emulsification was detected in both experiments, possibly linked to the n-alkanes depletion, with differences in emulsification start times and extents according to the initial hydrocarbon concentration. Both facts influenced the hydrocarbon biodegradation kinetics. A sequential biodegradation of n-alkanes and UMC was found for the higher hydrocarbon content. Being the former growth associated, while UCM biodegradation was a non-growing process showing enzymatic-type biodegradation kinetics. For the lower hydrocarbon concentration, simultaneous biodegradation of n-alkanes and UMC were found before emulsification. Nevertheless, certain UCM biodegradation was observed after the medium emulsification. According to the observed kinetics, three main types of hydrocarbons (n-alkanes, biodegradable UCM and recalcitrant UCM) were found adequate to represent the multicomponent substrate (bilge waste) for future modelling of the biodegradation process.
authors.affiliation: Centro Nacional Patagónico, Unidad de Investigación de Oceanografía y Meteorología, Laboratorio de Oceanografía Química y Contaminación de Aguas, CONICET, Bv. Brown 2825, U9120ACF, Puerto Madryn, Argentina. nievas@cenpat.edu.ar
authors.forename: M L
authors.initials: ML
authors.lastname: Nievas
authors.forename: M G
authors.initials: MG
authors.lastname: Commendatore
authors.forename: J L
authors.initials: JL
authors.lastname: Esteves
authors.forename: V
authors.initials: V
authors.lastname: Bucalá
mesh_terms: D001673:Biodegradation, Environmental; D015169:Colony Count, Microbial; D045703:Emulsifying Agents; D005648:Fuel Oils; D006838:Hydrocarbons / Q000378:metabolism*; D009391:Nephelometry and Turbidimetry; D012767:Ships; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D045703:Emulsifying Agents; D005648:Fuel Oils; D006838:Hydrocarbons; D014874:Water Pollutants, Chemical