Detection of polycyclic aromatic hydrocarbons along Alexandria's coastal water, Egyptian Mediterranean Sea

This paper provides important information about the compositions and concentrations of polycyclic aromatic hydrocarbons in Alexandria's coastal seawater during winter of 2015. By applying gas chromatographic technique using the FID detector, the determination of PAHs in seawater was used as a chemical signature to recognize various sources of PAHs pollutions. Concentrations were found to range between 13.4 and 6076 ng/L with a mean 991 ng/L; that exceeded the maximum admissible concentrations (200 ng/L) for the water standard of the European Union. Percentage distribution of water samples showed that 41.7% of the analyzed samples contained less than 500 ng/L and 4.2% exhibited high concentrations that exceeded 6000 ng/L. The PAHs of four, five and six rings were 84%, 16.7%, 5.5% of the total PAH, respectively; while low molecular-weight did not exceed 1.5%. The sources of PAHs in the investigated area were mainly from pyrolytic origin that had been derived from incomplete combustion of the fuel of boats and vehicle engines with little evidence of petrogenic origins in El-Mex and Abou-Qir bay. Contribution of PAHs from El-Mex Bay and Eastern Harbor was found to be 2,860 and 15.3 kg/year, respectively.