Analysis of the Physicochemical Properties and Polycyclic Aromatic Hydrocarbons (PAH) Content of Produced Water of Selected Flow Stations in Edo and Delta States Of Nigeria

Produced water is wastewater generated during the extraction of oil and natural gas from underground reservoirs. The water is a complex mixture typically containing various dissolved and suspended organic and inorganic compounds, including hydrocarbons, salts, heavy metals and chemical additives introduced into the well to enable extraction. The physicochemical properties of Produced Water differ based on various factors such as the chemical composition of the oil and gas in the reservoir, depth, the geologic age, and the geochemistry of the hydrocarbon-bearing formation. The study analyzed the physicochemical properties and polycyclic aromatic hydrocarbons (PAHs) content of Produced Water from flow stations in Edo and Delta States, Nigeria. The water samples were obtained from the Oredo and Batan flow stations located in Edo and Delta States, Nigeria and the physicochemical properties of the water samples were determined using standard procedures. The PAHs content of the Produced water samples were extracted using hexane and dichloromethane solvents, concentrated, and analyzed for PAHs using Gas Chromatography.  pH, turbidity, TDS, TSS, anions, and cations were within national and international regulatory limits, while BOD and COD values greatly exceeded permissible standards. The PAHs contents analysis revealed a significant difference between Batan (0.0251ppm) and Oredo (0.1276ppm) flow stations. The higher PAHs concentration at Oredo suggests a stronger impact of oil-related activities. PAHs like Anthracene, Fluoranthene, Pyrene, and Benzo(b)fluoranthrene) found in Oredo are carcinogenic and resistant to degradation, posing greater ecological and health risks. The findings highlight the need for stricter monitoring and improved produced water treatment in Oredo flow station to reduce environmental and public health risks. Chronic exposure to these pollutants can lead to bioaccumulation in aquatic organisms and contamination of the food chain. The study's results emphasize the importance of proper management and treatment of produced water to mitigate its impact on the environment and human health. Regular monitoring and analysis of produced water can help identify potential risks and inform strategies for reducing pollution.