Bioremediation of mechanic workshop polluted soil amended with poultry litter

This study focused on the use of 40% w/w poultry litter to remedy soil polluted with spent oil released to the environment in mechanic workshops. Soil samples were obtained in pots, treated with poultry litter and observed for a period of 56 days. Pots A and B served as unpolluted and polluted control while pot C served as the polluted sample that was amended. The bacterial count ranged from 6.3 × 10³ to 6.8 × 10⁴ cfu/g in unpolluted soil (US), 8.0 × 10³ to 9.8 × 10⁴ cfu/g in mechanic workshop soil (MS) and 1.72 × 10⁴ to 1.80 × 10⁵ cfu/g mechanic workshop soil amended with poultry litter (MSAP). Fungi counts ranged from 2.5 × 10³ to 3.0 × 10⁴ cfu/g in US, 2.8 × 10³ to 4.0 × 10⁴ cfu/g in MS, and 9.2 × 10³ to 1.68 × 10⁵ cfu/g in MSAP. There were no significant differences in the bacteria and fungi counts at 5% probability level. Bacteria genera that were commonly isolated from the samples include Bacillus sp, Pseudomonas sp, Micrococcus sp, Staphylococcus sp, and Proteus sp. while fungi genera include Aspergillus sp., Mucor sp. and Saccharomyces sp. There were no significant differences (P > 0.05) in pH, moisture, nitrogen, organic carbon and electrical conductivity. However, significant differences were observed in organic matter and phosphorus between the treatments (US, MS, MSAP) at 5% probability level. The results of this work strongly support the use of poultry litter in reclaiming hydrocarbon polluted soil.