Phytoremediation of diesel and spent engine oil contaminated soil using Kariya (Hildergardia barteri Mast.) seedlings

Using a completely randomized design experiment, the effect of different levels of diesel and spent engine oil contamination (0 mL/kg, 25 mL/kg, 50 mL/kg and 75 mL/kg of soil) on growth performance (seedling height, collar diameter, number of leaves and biomass accumulation) of Hildergardia barteri seedlings were assessed for twelve weeks. The concentration of Lead, Nickel, Copper and Zinc in the plant parts were also determined. Data were analysed using descriptive and inferential statistics at P<0.05 level of significance. There were significant differences in the effects of diesel and spent engine oil on growth performance of seedlings based on contamination levels. Control treatment had the highest height (92.43±5.13 cm), collar diameter (16.23±0.98 mm), number of leaves (11.21±0.47) and total biomass (33.01±12.79 g). Seedlings exposed to 50 mL/kg treatments had the least height (diesel oil: 78.21±7.22 cm; spent engine oil: 79±6.24 cm); those exposed to 75 mL/kg contamination had the least collar diameter (diesel oil: 8.85±1.05 mm, spent engine oil: 12.02±1.01 mm), while seedlings treated with 50 mL/kg diesel oil (2.21±0.37) and 75 mL/kg spent engine oil (4.79±0.55) had the lowest number of leaves. Heavy metal bio-accumulation ranges were: Lead: 0.17-0.39 mg/kg, Nickel: 0.09–0.45 mg/kg, Copper: 0.54–1.08 mg/kg, Zinc: 0.88–1.58 mg/kg. The ability of the seedlings to survive and bio-accumulate heavy metals indicate the potential phytoremediation capabilities of Hildergardia barteri. Keywords: phytoextraction, hydrocarbon derivatives, growth inhibition, Hildergardia barter

Evaluation of Poultry Manure and Cow Dung on Solanum lycopersicum L Planted on Spent Oil Polluted Soil

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