Document Type : Research Paper

Authors

• Mohammad Nemati Varnosfaderany
• Alireza Riyahi Bakhtiari

Tarbiat Modares University

Abstract

To assess the sources, entry routes and degree of contamination of PAH compounds in surface sediments of the southwestern Caspian Sea coasts (Gillan province) total of 129 surface sediment samples from 28 rivers and 5 transect across the Gillan province coasts (from Astara to Lahijan; 10, 20 and 50 m depth) were collected in the spring and summer of 2012. After extraction using Soxhlet method, the samples were analysed using Gas chromatography-Mass spectrometry (GC-MS) and concentrations of 30 PAH compounds were determined. The mean of total 30 PAH compounds (TPAH30) in the coastal sediments (565.1±266.1 ng g-1) have shown significant difference (p<0.01) with the river sediments (301.9±195.7 ng g-1). The PCA results beside the general agreement with the other source identification methods were well able to classify compounds attributed to the three main sources of PAHs (petrogenic, pyrogenic and biogenic) and to identify taking effect of each sample from them. Dominant source of the PAHs in the studied sediments was petrogenic, except at some more contaminated rivers such as Shafaroud, Karganroud and Lavandevil Chay Rivers that mainly presented pyrogenic source. The concentration of most PAHs was lower than critical level (NOAA and CCME guidelines), except of some petrogenic PAHs with lower molecular weight (2-3 rings) and alkyl group.

Keywords

• PAHs
• Source Identification
• sediments
• Caspian Sea
• Guilan province