Abstract

 The discharge of used petroleum products from machines such as power generating sets, vehicles and motorcycles has become a major source of soil pollution around Uyo metropolis. The objectives of this study were to assess the microbiological and physicochemical characteristics of soils contaminated with used petroleum products. A total of four (2) sampling sites (filling stations and mechanic workshop) were investigated. The total heterotrophic bacterial and fungal counts ranged from 8.0x10°to 9.5x10CFU/g and 1.0x10°to 1.1x10°CFU/g respectively. The hydrocarbon utilizing bacterial and fungal counts ranged from 3.6x10°to 1.1x10°CFU/g and 1.0x10° to 1.4x106CFU/g respectively. The bacterial isolates were Pseudomonas aeruginosa, Escherichia coli, K/ebsiel/a spp, Staphylococcus aureus, Micrococcus spp, Bacillus spp, Citrobacter spp. Fungal isolates included Aspergi/lus spp, Mucor spp, Rhizopus spp, Penicilium spp. The total organic carbon concentration ranged from 5.20 to 16.74 mg/kg and 4.81 mg/kg for control. The contamination also affected other physicochemical parameters such as phosphate, sulphate and nitrate and ranged from 2.3 to 3.10 mg/kg, 13.80 to 15.70 mg/kg and 1.82 to 1.74 mg/kg respectively compared to the control sample, 43.2 mg/kg, 36.7 mg/kg and 39.5 mg/kg respectively. Calcium, sodium, potassium, conductivity, total petroleum hydrocarbon, magnesium, and iron. These adverse conditions have impacted negatively on soils around the polluted site could affect nutrient cycles and consequently affect vegetation around the area.