A study of natural attenuation processes involved in a microcosm model of a crude oil-impacted wetland sediment in the Niger Delta

Bioresour Technol. 2008 Jul;99(11):4761-7. doi: 10.1016/j.biortech.2007.09.063. Epub 2007 Nov 7.

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.

MeSH terms

  • Bacteria / isolation & purification
  • Biodegradation, Environmental
  • Fresh Water
  • Geologic Sediments* / chemistry
  • Geologic Sediments* / microbiology
  • Hydrocarbons / analysis
  • Models, Biological*
  • Nigeria
  • Petroleum / metabolism*
  • Wetlands*

Substances

  • Hydrocarbons
  • Petroleum