1 School of Civil Engineering, Universiti Sains Malaysia

2 Civil Engineering Department, Universiti Teknologi PETRONAS

3 Department of Civil Engineering, Auburn University

4 School of forestry and wildlife sciences, Auburn University


Bioremediation, the process by which microorganisms degrade organic compounds to non-toxic or less toxic substances, has been widely used for cleanup of coastal ecosystems after oil spills. In this study, the hydrocarbon degradation rate and half lives in three bioremediation strategies (natural attenuation, biostimulation, and bioaugmentation) were compared in weathered crude oil (WCO) contaminated sediment samples. Three initial WCO concentrations of 3, 30 and 60 g WCO per kg sediment were investigated. Kinetic evaluations were carried out in a 90-day laboratory scale experiment. All oiled sediments showed decreasing WCO concentrations over time. After two weeks, the rate of degradation in the natural attenuation experiments stayed approximately constant. Bioaugmentation demonstrated higher oil removal than biostimulation or natural attenuation. The results indicated that first order kinetics can describe bioremediation of crude oil in sediments. The values of R2 (coefficient of determination) varied from 0.9552 to 0.9965. The first order kinetic constant for the reactors at different WCO concentrations was between 0.0014 and 0.0159/day. The half life of WCO in sediment reactors was different for each applied method. The minimum WCO half life for natural attenuation, biostimulation and bioaugmentation was 408, 69 and 44 days respectively.


Abbassi, B. E.; Shquirat, W. D., (2008). Kinetics of Indigenous Isolated Bacteria used for Ex-Situ Bioremediation of Petroleum Contaminated Soil. Water Air Soil Pollut, 192, 221-226.
Abioye, P. O.; Aziz A. A.; Agamuthu, P., (2010). Enhanced Biodegradation of Used Engine Oil in Soil Amended with Organic Wastes, Water Air Soil Pollut. 209, 173–179.
Adesodun, J. K.; Mbagwu, J. S. C., (2008). Biodegradation of waste-lubricating petroleum oil in a tropical alfisol as mediated by animal droppings, Bioresour. Technol, 99, 5659–5665.
Aghamiri, S. F.; Kabiri, K.; Emtiazi, G., (2011). A Novel Approach for Optimization of Crude Oil Bioremediation in Soil by the Taguchi Method. J Pet Environ Biotechnol 2:108.doi:10.4172/2157-7463.1000110.
Barrios San Martín, Y., (2011). Bioremediation: a tool for the management of oil pollution in marine ecosystems. Biotecnología Aplicada, 28 (2) 69-76.
Chang, L. K.; Ibrahim, D.; Che Omar, I., (2011). A laboratory scale bioremediation of Tapis crude oil contaminated soil by bioaugmentation of Acinetobacter baumannii T30C. African Journal of Microbiology Research, 5 (18) 2609-2615.
Chen, J.; Wong, M. H.; Wong, Y. S.; Tam, N. F. Y., (2008). Multi-factors on biodegradation kinetics of polycyclic aromatic hydrocarbons (PAHs) by Sphingomonas sp. a bacterial strain isolated from mangrove sediment, Mar. Pollut. Bull. 57, 695–702.
Couto, M. N. P. F. S.; Monteiro, E.; Vasconcelos, M.T.S. D., (2010). Mesocosm trials of bioremediation of contaminated soil of a petroleum refinery: comparison of natural attenuation, biostimulation and bioaugmentation, Environ. Sci. Pollut Res. 17, 1339-1346
Di Toro, S.; Zanaroli, G.; Fava, F., (2006). Intensification of the aerobic bioremediation of an actual site soil historically contaminated by polychlorinated biphenyls (PCBs) through bioaugmentation with a non acclimated, complex source of microorganisms, Microb. Cell. Fact. 6, 1-10.
Dimitrov, S.; Pavlov, T.; Nedelcheva, D.; Reuschenbach, P.; Silvani, M.; Bias, R.; Comber, M.; Low, L.; Lee, C.; Parkerton, T.; Mekenyan, O., (2007). A kinetic model for predicting biodegradation. SAR and QSAR in Environ. Res. 18, 443-457.
Kumar, A.; Bisht, B. S.; Joshi, V. D.; Dhewa, T., (2011). Review on Bioremediation of Polluted Environment: A Management Tool, Int. J. Environ. Sci. Tech., 1 (6), 1079-1093.
Mahanty, B.; Pakshirajan, K.; Dasu, V. V., (2010). A two liquid phase partitioning bioreactor system for the biodegradation of pyrene: Comparative evaluation and cost–benefit analysis, J. Chem. Technol. Biot. 85, 349-355.
Maletić, S.; Dalmacija, B.; Rončević, S.; Agbaba, J.; Petrović, O., (2009). Degradation Kinetics of an Aged Hydrocarbon-Contaminated Soil, Water Air Soil Pollut. 202, 149–159.
Margesin, R.; Schinner, F., (2001). Bioremediation (Natural Attenuation and Biostimulation) of Diesel-Oil-Contaminated Soil in an Alpine Glacier Skiing Area, Appl. Environ. Microb. 67, 3127-3133.
Mills, M. A.; Bonner, J. S.; Page, C. A.; Autenrieth, R. L., (2004). Evaluation of bioremediation strategies of a controlled oil release in a wetland, Mar. Pollut. Bull. 49, 425–435.
Mohajeri, L.; Aziz H. A.; Zahed M. A.; Mohajeri S.; Kutty S. R. M.; Isa M. H., (2011). Response surface analysis and modeling of n-alkanes removal through bioremediation of weathered crude oil, Water Science and Technology, 63.4: 618-626.
Mohajeri, L.; Aziz, H. A.; Isa M. H.; Zahed, M. A., (2010a). A statistical experiment design approach for optimizing biodegradation of weathered crude oil in coastal sediments, Bioresour. Technol. 101, 893-900.
Mohajeri, L.; Aziz, H. A.; Isa, M. H.; Zahed, M. A.; Mohajeri, S., (2010b). Ex-situ bioremediation of crude oil in soil, a comparative kinetic analysis, Bull. Environ. Contamin. Toxicol. 85, 54-58.
Onwurah, L. N. E.; Alumanah, E. E., (2005). Integration of biodegradation half-life model and oil toxicity model into a diagnostic tool for assessing bioremediation technology, Indust. Biotechnol. 1, 292-296.
Padayachee, D.; Lin, J., (2011). The effect of fertilizer amendment on diesel biodegradation in contaminated soils. African Journal of Microbiology Research, 5(14),1729-1739.
Pala, D. M.; de Carvalho, D.; Pinto, J.; Sant’Anna Jr. G., (2006). A suitable model to describe bioremediation of a petroleum-contaminated soil, Int. Biodeter. Biodegr, 58, 254–260.
Prasanna, D.; Mohan, S. V.; Reddy, P.; Sarma, P. N., (2008). Bioremediation of anthracene contaminated soil in bio-slurry phase reactor operated in periodic discontinuous batch mode, J. Hazard. Mater. 153, 244-251.
Prince, R.C., (2010). Bioremediation of Marine Oil Spills, In: Handbook of Hydrocarbon and Lipid Microbiology, Editor: Kenneth N. Timmis, Springer, Berlin.
Roncević,  S.; Dalmacija, B.; Ivančev-Tumbas, I.; Tričković, J.; Petrović, O.; Klašnja M.; Agbaba, J., (2005). Kinetics of degradation of hydrocarbons in the contaminated soil layer, Arch. Environ. Con. Tox, 49, 27-36.
US-EPA, (1991). Test Methods for Evaluating Solid Waste, SW 846, US Environmental Protection Agency, Cincinnati, OH.
US-EPA, (1999). Method 1664, Revision A: N-Hexane Extractable Material (HEM; Oil and Grease) and Silica Gel Treated N-Hexane Extractable Material (SGT-HEM; Non-polar Material) by Extraction and Gravimetry, US Environmental Protection Agency, Cincinnati, OH.
Venosa, A. D.; Holder, E. L., (2007). Biodegradability of dispersed crude oil at two different temperatures, Mar. Pollut. Bull. 54, 545–553.
Wang, Q.; Zhang, Sh.; Li,Y.; Klassen, W., (2011). Potential Approaches to Improving Biodegradation of Hydrocarbons for Bioremediation of Crude Oil Pollution. Journal of Environmental Protection, 2, 47-55.
Yousefi Kebria, D.; Khodadadi, A.; Ganjidoust, H.; Badkoubi, A.; Amoozegar, M. A., (2009) Isolation and characterization of a novel native Bacillus strain capable of degrading diesel fuel, Int. J. Environ. Sci. Tech., 6 (3), 435-442.
Zahed, M. A.; Aziz, H. A.; Isa, M. H.; Mohajeri, L., (2010). Effect of initial oil concentration and dispersant on crude oil biodegradation in contaminated seawater, Bull. Environ. Contamin. Toxicol. 84, 438-442.