Evaluation of the extent of pollution of discharged oil field brine in the Bonny estuary, Niger Delta, Nigeria

• Published in: Environmental earth sciences Vol. 77; no. 10; pp. 1 - 17
• Main Authors: Okogbue, C. O., Oyesanya, O. U., Anyiam, O. A., Omonona, V. O.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.05.2018; Springer Nature B.V
• Subjects: Ammonia; Aromatic compounds; Aromatic hydrocarbons; Benzene; Biogeosciences; Brines; Chemical analysis; Composition; Constituents; Contaminants; Deltas; Dry season; Earth and Environmental Science; Earth Sciences; Environmental Science and Engineering; Estuaries; Estuarine dynamics; Ethyl benzene; Evaluation; Fluvial sediments; Geochemistry; Geology; Heavy metals; Hydrocarbons; Hydrology/Water Resources; Lead; Marine environment; Metals; Nickel; Oil pollution; Original Article; Petroleum; Petroleum hydrocarbons; Phenols; Phosphates; Physicochemical processes; Physicochemical properties; Pollutant load; Pollution; Pollution index; Pollution load; Polycyclic aromatic hydrocarbons; Rivers; Saline water; Seasons; Seawater; Sediment; Sediment pollution; Sediment samplers; Sediment samples; Sediments; Sulfates; Terrestrial Pollution; Toluene; Wastewater; Water analysis; Water discharge; Water pollution; Water quality; Water sampling; Xylene; Zinc; Nigeria; Niger Delta; Sediments and seawater pollution; Produced water; Heavy metals; Bonny estuary
• ISSN: 1866-6280; 1866-6299
• DOI: 10.1007/s12665-018-7559-3

This is an assessment of the degree of effects of discharged produced water in river and sediments of the Bonny estuary, Niger Delta. It involved seasonal analyses of twenty-two (22) water and thirty-four (34) sediment samples from the Bonny River. The physicochemical properties (i.e., hydrocarbon content, heavy metals, and other inorganic constituents) of the water samples were examined, while the sediments were inspected for heavy metals and organic hydrocarbon constituents that may have been sourced from the discharged produced water. In addition, the principal component and cluster analyses, index of geoaccumulation, and pollution load index plots were utilized to deduce the degree of pollution, source, and distribution of these contaminants. From the results of the analyses, the Bonny seawater is contaminated with nitrate, phosphates, nickel, ammonia, and phenols in dry season, whereas nitrate, sulfate, phosphate, total nitrogen, total petroleum hydrocarbon (TPH), and heavy metals—zinc and lead—are observed in the rainy (wet) season. Similarly, the sediments are contaminated with benzene, toluene, ethyl benzene, xylene, polycyclic aromatic hydrocarbon, TPH, phenols, and heavy metals in both seasons. Considering the outcomes of these analyses, it is evident that the composition and quality of seawater and sediments of the Bonny estuary have been strongly influenced by produced water discharges in the area.