title: A study of natural attenuation processes involved in a microcosm model of a crude oil-impacted wetland sediment in the Niger Delta.
abstract: Sediment sample from a previously impacted Ochani stream was recreated in four glass chambers (A-D) as microcosms. The aim was to model and compare natural attenuation processes to forced aeration for remediation of a crude oil-impacted ecosystem. The initial hydrocarbon concentration was 90,212 mg/kg of sediment. After 60 days, the natural attenuation processes of photooxidation, evaporation, volatilization and biodegradation accounted for 31.9% of the total hydrocarbon removed while 13% was attributable to forced aeration, bringing the cumulative hydrocarbon removed to 44.9%. Photooxidation, evaporation and volatilization accounted for 15.6% of the total hydrocarbon removed. Biodegradation alone accounted for 24.7% removal. Gas chromatographic tracings showed appreciable reductions in peak heights and base. Hydrocarbon utilizing bacteria genera isolated included Pseudomonas, Micrococcus, Flavobacterium, Staphylococcus, Serratia, Bacillus, Chromobacterium, and Alkaligenes. Temperature was mesophilic (26-31 degrees C), while the pH tended towards acidity. The study revealed the applicability and the effectiveness of natural attenuation and forced aeration in the remediation of oil-impacted sediment in a typical Niger Delta setting.
authors.affiliation: Department of Microbiology, University of Port Harcourt, PMB 5323, Port Harcourt, Nigeria. gideonabu1@yahoo.com
authors.forename: Gideon O
authors.initials: GO
authors.lastname: Abu
authors.forename: Paschal O
authors.initials: PO
authors.lastname: Dike
mesh_terms: D001419:Bacteria / Q000302:isolation & purification; D001673:Biodegradation, Environmental; D005618:Fresh Water; D019015:Geologic Sediments / Q000737:chemistry / Q000382:microbiology; D006838:Hydrocarbons / Q000032:analysis; D008954:Models, Biological; D009549:Nigeria; D010578:Petroleum / Q000378:metabolism*; D053833:Wetlands
chemical_list: D006838:Hydrocarbons; D010578:Petroleum