Remediation of crude oil contaminated soil by enhanced natural attenuation technique
Ebuehi, O.A.T.; Abibo, I.B.; Shekwolo, P.D.; Sigismund, K.I.; Adoki, A.; Okoro, I.C.
Journal of Applied Sciences and Environmental Management 9(1): 103-106
2005
Document Number: 260047
The concentrations of nitrogen, phosphorus, total hydrocarbon utilizing bacteria (THUB), total heterotrophic bacteria (THB) and total petroleum hydrocarbon were determined using the remediation by enhanced natural attenuation (RENA) in a crude oil contaminated farmland in Rivers state, Nigeria. A TPH concentration of 1.1004x104 mg/kg of the sandy soil was achieved after spiking and tilling. There was a reduction in the TPH level from 300 mg/kg after 8 weeks to 282 mg/kg after 10 weeks. No significant reduction in the TPH level was observed after the 10th week. The nitrogen and phosphorus levels of the sandy soil were 24.6 and 22.8 mg/kg respectively. This suggests that the nitrogen and phosphorus levels could no longer support biodegradation at the residual TPH levels of 282 mg/kg and 22.8 mg/kg after spiking and tilling, respectively, which further reduced to 0.12 mg/kg and 1.7 mg/kg, respectively after 10 weeks. The total hydrocarbon utilizing bacteria (THUB) increased from 3.0x104 cfu/g to 8.55x104 cfu/g and finally reduced to 5.38x104 cfu/g, while the total heterotrophic bacteria (THB) reduced from 1.22x108 cfu/g to 5.98x105 cfu/g. Data of the study indicate that remediation enhanced natural attenuation technique could be employed to remediate a farm settlement contaminated by crude oil.