Source identification of marine tar balls on the Iranian coasts of the Persian Gulf using FTIR spectroscopy and PCA

Existence of oil fields among the offshore areas in the Persian Gulf, caused the entrance of hydrocarbon pollutants that appear in coastal areas as a shape of tar ball. This study aimed to develop a novel, cost-effective, and rapid method for source identification using Fourier Transform Infrared (FTIR) spectroscopy. Asphaltene fraction from 16 oil samples (Geneaveh, Bahregansar, Abouzar, Soroush, Kharg, Norouz and South Pars fields) and 41 tar ball samples (collected from AT, BT, DT, GT, RT and ST stations) were analyzed. After asphaltene extraction and FTIR analysis, Principal Component Analysis (PCA) was performed in three stages (for oil samples, tar ball samples and overall) based on aliphatic, aromatic, carbonyl, condensation, ramification and sulfide indices. PCA results indicated that the Bahregansar and Genaveh oil fields are the likely source of pollutant for tar balls found at BT, AT, RT, and GT stations. Notably, none of the oil samples analyzed were identified as sources for the tar balls collected at ST and DT stations, nor were any other studied oil samples identified as potential origins for these remaining tar balls.