Research Article
Makia M. Al-Hejuje; H. T. Al-s
Abstract
Surface sediments samples were collected monthly during December , 2012 to November , 2013 from five stations located at the Shatt Al-Arab River to determine the concentrations , distribution and the sources of hydrocarbons compounds in sediments samples. Total Petroleum Hydrocarbons (TPH) concentrations in sediments was range from 4.76 μg/g dry weight to 45.24 μg/g dry weight . The carbon chain length of aliphatic ( n-alkanes) were recorded from C7-C31 dominated by C22-C25 , and the total n-alkanes concentration in sediments was ranged from 4.76 μg/g dry weight to10.09 μg/g dry weight . The range of PAHs was ranged from 4.318 ng/g dry weight to 28.48 ng/g dry weight dominated by carbazol and anthracene ( as light PAHs) and indeno (1,2,3,c,d) pyrene and benzo(g,h,i)perylene (as heavy PAHs). The LMW/HMW ,CPI index and Pristane/Phytane ratio indicated that the source of n-alkanes hydrocarbons was mainly biogenic and pyrogenic and at least petrogenic . Whereas the LMW/HMW , Phenanthrene /Anthracene , and Flouranthene / Pyrene ratios indicated that the source of PAHs was pyrogenic only. non- significant correlation was found between hydrocarbons concentrations and each of TOC% or grain size of the sediments .