Spectrophotometric Analysis of Crude Oil Contaminated Water Samples from Ogoniland

Oil spill contamination of surface water and groundwater in Ogoniland, Rivers State, South South Nigeria, has been extensively documented as a major environmental catastrophe with persisting ecological and public health consequences. This study applies UV-Visible spectrophotometry to characterize and quantify petroleum hydrocarbon constituents in water samples collected from twelve contaminated water bodies across Ogoniland. Sampling was performed at depths of 0.5 m and 1.0 m at each site, and samples were analyzed within six hours of collection to minimize volatile compound loss. The total petroleum hydrocarbon concentration was determined using an absorbance peak at 254 nm after solvent extraction with dichloromethane, calibrated against standard petroleum solutions. The aromatic fraction was characterized by scanning the UV-Vis spectrum between 200 nm and 400 nm to identify benzene, toluene, and naphthalene peaks. Results indicate total petroleum hydrocarbon concentrations ranging from 2.3 mg/L to 187.4 mg/L, with the highest values recorded in stagnant creek water near former flow station sites. All samples exceeded the Nigerian Department of Petroleum Resources guideline limit of 0.05 mg/L for hydrocarbons in surface water. The study maps contamination severity across Ogoniland sampling sites and correlates contamination levels with proximity to identified spill points. Remediation pathways including bioremediation and photocatalytic degradation are recommended for priority intervention zones. Keywords: spectrophotometry, crude oil contamination, Ogoniland, total petroleum hydrocarbons, water quality