ABSTRACT
Today, petroleum-based products in all their forms serve as the primary source of energy for both industry and daily living. However, the indiscriminate release of used engine oil into the environment by auto repair businesses has significantly increased environmental contamination in both the terrestrial and aquatic realms, posing a serious threat to the health of plants, animals, and microbial community. The poultry manure biomass used for this study was obtained from the poultry farm located along bank road of the University of Benin, Ugbowo campus, Benin-city, Edo state, while the Soil sample used for this study was collected from an open field located at the faculty of Agriculture of the University of Benin, Ugbowo campus, Benin-city, Edo state and the spent engine oil was obtained from a mechanic workshop along federal girls’ college at Ugbowo in Egor L.G.A, Benin City, Edo state. The Poultry manure biomass and the soil samples were air dried for a period of 1 week, reduced into a particle size of 2mm and characterized in term of its physicochemical properties. The pH of the soil was determined to be (7.29±0.09), while that of the poultry manure biomass was determined to be (8.13±0.15), Electrical conductivity (EC) of the soil recorded (101.30± 0.92μS/cm), while that of the poultry manure biomass was (5.88± 0.06mS/cm), Bulk density of the soil was measured at (1.31± 0.10g/ml), while that of the poultry manure biomass was (0.31±0.01g/ml). Furthermore, the results revealed that the poultry manure biomass possess a substantial content of essential nutrients, including nitrogen (41.75mg/kg), phosphorus (261.25mg/kg), potassium (488.75mg/kg), sodium (529.5mg/kg), calcium (7mg/kg), and magnesium (146.5mg/kg). More importantly, the concentrations of specific heavy metals in the poultry manure biomass were all found to be below the established threshold values considered safe for soil and the heavy metals concentration for poultry manure biomass are nickel (22.25mg/kg), cadmium (BDL), lead (0.7mg/kg), copper (15.75), and chromium (43.75). The textural analysis carried out on the soil showed that the soil contains sand (87%) and slit (13%). The poultry manure biomass was also characterized in terms of FTIR, SEM/EDS and BET. The FTIR analysis carried out on the poultry manure biomass, showed the functional groups present in the sample, such as O-H, C-H, S-C≡N, C=C and N-H. The BET surface area, pore volume and average pore diameter of the poultry manure biomass obtained were 316.7m^2⁄g, 0.162〖cm〗^3⁄g, and 2.96nm respectively. SEM micrographs revealed that the poultry manure biomass have rough and porous surfaces, while EDS revealed that the elemental composition of the poultry manure biomass consists mainly of Si (48.0%), O₂ (20.1%), Al (12.6%), Fe (6.20), C (6.0), Ca (2.30) and K (1.20) with few traces of Mn (0.43) and Mg (0.28). Additionally, the lactonic group constituted the highest percentage of the total surface acid functional groups.
