ANALYTICAL ASSESSMENT OF GEOCHEMICAL AND PHYSICAL PROPERTIES OF FRACTIONATED BITUMEN IN AGBABU AND LODA, NIGERIA

This study presents a comparative evaluation of the physical properties and chemical speciation of bitumen samples obtained from Agbabu and Loda in the Ilaje area of Ondo State, Nigeria. The physical properties analyzed include bitumen content, sand content, penetration test, specific gravity, Marshall Stability, and viscosity at 60°C. Agbabu bitumen exhibited higher durability indicators with bitumen content of 79.80% ± 0.01 and sand content of 10.90% ± 0.01, compared to Loda bitumen which showed 46.50% ± 0.01 and 53.10% ± 0.01 respectively. Penetration tests were similar for both samples, with values of 44.50 ± 0.02 for Agbabu and 45.30 ± 0.01 for Loda. Specific gravity, Marshall Stability, and viscosity values were also generally higher in Agbabu bitumen, suggesting superior physical performance. Chemical analysis revealed that concentrations of heavy metals—Pb, Cd, Cu, Ni, Mn, Cr, Zn, and Fe—were generally higher in Loda bitumen. Notably, iron concentrations were exceptionally elevated in both samples (9,201.25 ± 0.20 mg/kg for Agbabu and 10,700.07 ± 0.50 mg/kg for Loda). Comparisons with recent studies indicate that levels of Fe, Zn, Pb, Ni, and Cu are lower in this work, likely due to differences in extraction and analytical methods. Fractionation studies demonstrated that iron predominantly occurs in the residue fraction rather than carbonate or organic-bound fractions, while heavy metals showed low affinity for the organic fraction in Loda bitumen. These findings underscore significant differences in physical and chemical properties of bitumen from the two sources, with implications for their industrial use and environmental management