Petroleum hydrocarbons in the sediments of Areba River, Olomoro, Niger Delta, Nigeria

The concentrations of petroleum hydrocarbons in the sediments of River Areba, Olomoro, Isoko Local Government Area, Niger Delta, Nigeria were investigated from January to December, 2000. Sediment samples were collected monthly from two stations. Station 1, is inundated with oil fields, waste pits, borrow pits, a gas compressor and two flow stations and while station 2, 5.30km downstream of station 1, is free of petroleum hydrocarbon activities. Monthly Total Petroleum Hydrocarbons (TPH) values by Gas Chromatography (GC) analysis ranged from 16.80mg/kg to 256.10mg/kg. Seasonally, TPH values were higher during the dry season in both stations. Five aliphatic components (Undecane, Dodecane, Tridecane, Tricosane, Tetracosane) and three aromatic components (naphthalene, pyrene and benzo(a) pyrene) were detected by Gas Chromatography (GC). The sediments of the two stations were heavily polluted with petroleum hydrocarbons when compared to the values obtained from chronically polluted sediments elsewhere. Keywords: sediments, petroleum hydrocarbons, pollution, river Tropical Freshwater Biology 2003/2004 Vol. 12/13: 85-9