Evaluation of PAHs in Hydrocarbons Pollution, Biodegradation and Weathering Extent in Surface Sediments of the Kharg Island in the Persian Gulf

Kharg Island as the most important oil export terminal of Iran has faced entrance of various oil materials, so it seems necessary to know about the amount of these marine oil pollutants and their origin in this area. Oil hydrocarbons has entered in this water body as a result of numerous human activities like extraction, refinement, transmission and export of raw oil or from natural and biologic resources. The oil contamination has damaged the environment according to the different decomposed level of compounds which exist in diverse oil pollutants. The concentration of polycyclic aromatic hydrocarbons using sediment sampling across the coast was determined and compared the obtained concentrations with previous values. The observed PAH concentrations were obtained in the range between 9 to 1230 ng/g and indicated the more focus of PAHs in the eastern region of Kharg Island coast. In addition to investigating the sediment oil pollution by PAHs, this paper has attempted to determine the origin of aromatic compounds by developing a set of indexes. These indexes suggested that PAH concentrations have obtained from the combustion origin of hydrocarbons in the sediments, and have entered to the coastal sediment of Island by active flares that burn the sour gas by oil around the coast.Indices developed also corroborate the presence of degraded oil residue, high relative biodegradation and a degree of weathering of hydrocarbons in the surface sediment of the area, which suggest a chronic input of oil-related hydrocarbons in the neighborhood of the study region.