Integrated Use of n-Alkanes and Polycyclic Aromatic Hydrocarbons in the Source Identification Petroleum Hydrocarbons at 5, 15 and 30 m Depths in Noshahr and Amir Abad Ports, Caspian Sea

Background and

Petroleum hydrocarbons might have a natural origin, but human activity is the main source of these pollutants in the environment. This study was done to determine the origin of n-alkanes and PAHs in surface sediments of the southeastern coast of the Caspian Sea.

A total of 12 sediment samples from six stations in Noshahr and Amir Abad ports were collected from 5, 15 and 30 meters depths. The samples were analyzed using gas chromatography.

In order to determine the origin of the n-alkanes we used CPI index (0.40-1.20), and biomarkers such as U/R (1.20-5.40), LMW / HMW (1.90-24.00), Pristane and Phytane (0.13-0.65). Also, to identify the source of PAHs the ratios of LMW / HMW (1.31-3.31), Phenanthrene / Anthracene (10.35-12.88), Fluoranthene/Fl (0-0/43) + Pyrene, Benzo (a) anthracene / Chrysene (0.18-0/39), Fluoranthene / Pyrene (0.002-0.77) and An / An + Phe (0.01-0.09) were used. The results showed that n-alkanes and PAHs in the region both had petrogenic origins. This could be due to the reason that the studied regions are commercial ports with high rate of shipping activities.

According to this study oil extraction in the country of Azerbaijan was the main source of oil pollution in the region which polluted the water by anticyclonic flow.