Oil pollution especially Spent Lubricating Oil is a wide environmental problem in Nigeria. It constitutes potential toxic effects on soil, flora, fauna and humans and also making the environment unsightly. This study assessed the potential of kenaf plant as a phytoremediator grown in spent oil polluted soil for a period of 84 days (12 weeks). Pot experiment was conducted in the Nursery site of the Moist Forest Research Station, Forestry Research Institute of Nigeria (FRIN), Ibadan, Oyo State, Nigeria. The treatments: amended (with organic manure) and unamended (without organic manure) soils and three pollution levels (0, 3 and 6%) of spent engine oil, each filled in eight-liter plastic pots with 6 kg soil. Growth parameters: plant height, stem diameter and number of leaves were collected and Total Petroleum Hydrocarbon (TPH) in soil was determined. Data were analyzed using descriptive statistics and ANOVA. Results at 12 weeks (84 days) showed amended (control 0%) treatment having highest plant height (112.17 cm), stem diameter (8.92 cm) and number of leaves (178.43), while 6% unamended level of pollution had the lowest plant height (26.78 cm), stem height (1.62 cm) and number of leaves (8.06). Amended soil had the highest total percentage reduction of TPH (75.90, 90.05 and 90.30%), when compared with unamended soil with lowest values (76.88, 85.18 and 82.36%) at 0, 3 and 6 pollution levels, respectively. Reduction of TPH in the phytoremediation process was in this order of pollution levels 6%> 3%> 0%. This study revealed effectiveness of kenaf with organic amendment in remediating Total Petroleum Hydrocarbon in oil polluted soil, hence a good potential phytoremediator.

Pollution from Spent Lubricating Oil (SLO) is one of the major problems farmers encounter in Nigeria. The study is a completely randomized design with Ibadan Local tomato seedlings grown on the following treatments: 0 ml SLO (control), 75ml SLO, 35g of poultry-manure + 75ml SLO, 35g of cow-dung + 75ml SLO, and 4g of NPK + 75ml SLO replicated four times. Physico-chemical parameters of the soil, poultry manure (PM) and cow-dung (CD), heavy metals, and Total-Petroleum-Hydrocarbon (TPH) were determined before and after pollution using standard procedures. Tomato seedlings were transplanted into pots of amended soil with SLO (5 kg/2 plants) and monitored till maturity. Data were taken on growth, yield parameters and analyzed using ANOVA (p<0.05). Results showed significant differences among the treatments. The soil textural class was sandy-loamy with pH (7.2). Tomato in control plots had the highest values 48.30cm plant-height (PH), number-of-leaves (82.63) (NOL), number-of-fruits (0.98) (NOFR) and fresh-weight (0.55g) (FW). Tomato plants grown on CD amended had the lowest 14.40 cm PH, SLO at 75 ml had 6.00 and 1.71cm for NOL and SD, respectively. The NOFR 0.70 value was from PM amended, FW 0.10g was from SLO at 75ml. Heavy-metals bioaccumulation ranges were: Cu 3.00-36.61mg/kg and Zn 15.00-303.79mg/kg. The final TPHs ranged from 181.66 -1350.00mg/kg, while % TPH removal ranged from 4.69- 53.18%. Cow-dung treated soil reduced the amount of copper and zinc present compared with spent oil soil. The growth performance of tomatoes in this study suggests that soil amendment should be encouraged.