A case study of petroleum degradation in different soil textural classes

Reginald Kogbara, Josiah M. Ayotamuno, Daniel C. Worlu, Isoteim Fubara-Manuel

Research output: Contribution to journalArticle

5 Citations (Scopus)


Background: Patents have been granted for a number of techniques for petroleum biodegradation including use of micro-organisms for degradation of hydrocarbon-based substances and for hydrocarbon degradation in oil reservoirs, but there is a dearth of information on hydrocarbon degradation in different soil textures. Objective: Hence, this work investigated the effects of different soil textures on degradation of petroleum hydrocarbons during a six-week period. Methods: Five soil textural classes commonly found in Port Harcourt metropolis, Nigeria, namely sand, loamy sand, sandy loam, silty clay and clay, were employed. The soils were contaminated with the same amount of crude oil and then remediated by biostimulation. Selected soil properties were monitored over time. Results: Bacterial numbers declined significantly in the fine soil textures after petroleum contamination, but were either unaffected or increased significantly in the coarser soil textures. Hydrocarbon losses ranged from 42% - 99%; the sandy loam had the highest, while the clay soil had the least total hydrocarbon content (THC) reduction. The total heterotrophic bacterial (THB) counts generally corroborated the THC results. Fold increase in bacterial numbers due to remediation treatment decreased with increasing clay content. Conclusion: The results suggest that higher sand than clay content of soil favours faster hydrocarbon degradation. Hydrocarbon degradation efficiency increased with silt content among soil groupings such as fine and coarse soils but not necessarily with increasing silt content of soil. Thus, there seems to be cut-off sand and clay contents in soil at which the effect of the silt content becomes significant.

Original languageEnglish
Pages (from-to)108-115
Number of pages8
JournalRecent Patents on Biotechnology
Issue number2
Publication statusPublished - 1 Aug 2015
Externally publishedYes



  • Bacteria count
  • Bioremediation
  • Biostimulation
  • Contaminated soil
  • Soil texture
  • Total hydrocarbon content

ASJC Scopus subject areas

  • Biotechnology
  • Bioengineering
  • Applied Microbiology and Biotechnology

Cite this

Kogbara, R., Ayotamuno, J. M., Worlu, D. C., & Fubara-Manuel, I. (2015). A case study of petroleum degradation in different soil textural classes. Recent Patents on Biotechnology, 9(2), 108-115.