Bioremediation of Spent Engine Oil in Some Selected Contaminated Soils
[Thesis]
Sulayman, Hikmat Omolara
Ajiboye, A. E.
Kwara State University (Nigeria)
2019
135
M.S.
Kwara State University (Nigeria)
2019
The aim of this research is to investigate bioremediation of spent engine oil on some selected contaminated soils. Soil samples were collected from five (5) mechanic workshops along Taiwo-Oke within Ilorin metropolis. They were subjected to bioremediation using the land-farming approach. Physicochemical parameters of the soil samples before and after bioremediation were analyzed using standard methods. Bacteria were isolated using standard procedures and identified using biochemical tests and molecular methods. Physicochemical parameters of soil samples before bioremediation included particle size (all sandy in nature); pH (5.95 ± 0.07 - 6.25 ± 0.07); Organic carbon (8.18 ± 0.31 - 17.54 ± 1.87), Organic matter (18.34 ± 2.90 - 43.45 ± 9.12) and heavy metals (ND - 11.74 ± 0.07), while values obtained after bioremediation for pH, organic carbon, organic matter and heavy metals were 8.25 ± 0.07 - 8.90 ± 0.14, 13.07 ± 0.05 - 13.25 ± 0.84, 37.25 ± 1.06 - 44.80 ± 1.13, ND - 9.40 ± 0.04 respectively. Bacterial counts before and after bioremediation of soil samples were 2.50 ± 0.71 - 67.50 ± 2.12 x 105 CFU/mL and 6.50 ± 2.12 - 164.00 ± 11.31 x 105 CFU/mL respectively. The bacterial isolates were identified as Pseudomonas sp., Acinetobacter sp., Klebsiella sp., Bacillus sp., Enterobacter sp. and Aeromonas sp. while the hydrocarbon-utilizing bacteria were identified as Thalassospira mesophila strain JCM 18969; Pseudomonas fluorescens F113; Siccibacter turicensis LMG 23730; Pseudomonas Zeshuii strain KACC 15471; Pseudomonas stutzeri strain CGMCC 1.1803 and Marinobacter hydrocarbonoclasticus strain ATCC 49840. Total petroleum hydrocarbon in the soils before and after bioremediation had retention time of 7.182 - 24.96 and 22.752 - 28.513 respectively. It is concluded that the bacteria isolated effectively bioremediated the spent engine oil contaminated soils with a reduction of hydrocarbon pollutants.