Evaluation and analysis of polycyclic aromatic hydrocarbons (PAHs) in sediments for different Lebanese regions

Abstract

Water and sediment pollution is a growing environmental problem. Organic contaminants are transferred to the marine environment mainly through anthropological activities such as oil spills, industrial and agricultural waste, and fossil fuel combustion. Many of these pollutants have specific characteristics that allow them to bind to sediments. Polycyclic aromatic hydrocarbons (PAHs) are some of these organic substances. In Lebanon, the characterization of these chemical compounds is recent and was conducted only in a few studies. The objective of this thesis is to identify and determine the concentration of priority PAHs in the sediments of the Lebanese coast, mainly in the regions of Beirut, Tyre, Anfeh and Tripoli. To achieve this purpose, several experimental steps were performed: sampling, freeze drying, pressurized liquid extraction and gas chromatography. The total PAHs concentrations ranged from 0.504 μg/kg to 107.911 μg/kg. PAHs were mainly of pyrogenic origin, with some samples having a petrogenic source of contamination. Pyrogenic sources are mostly attributed to inadequate fuel combustion, while petrogenic sources can be related to oil leaks.