Zonning, distribution and sources of TPH and heavy metals in Mahshahr Bay sediments, Persian Gulf

Petroleum hydrocarbons and heavy metals are considered as common environmental contaminants and a worldwide concern. The aim of this study was to determine sediment contamination and to perform ecological risk assessments in the Mahshahr Bay.
Material and

Sediment samples were collected from the coastal area of the Petrochemical Special Economic Zone of Musa Estuary, which is located at the northwest of the Persian Gulf. Thirty-tow surficial sediment samples were collected. Total petroleum hydrocarbon (TPH) concentration of the sediment samples was determined using gas chromatography-flame ionization detector (GC-FID). Also, the concentration of metals (Al, As, Ba, Co, Cr, Cu, Mn, Ni, Sr and Zn) in surface sediment samples was determined using inductively coupled plasma atomic emission spectrometry (ICP-AES).

The average TPH concentration in the study area was 42 mg/kg. The highest TPH value was recorded at station 8. There was a significant difference between concentration of Al and the correspondent mean crust.

The contamination factor (CF), degree of contamination (Cd), modified degree of contamination (mcd) and Pollution load index (PLI) revealed overall low values for metals. The average TPH concentration in the study area was 42 mg/kg indicating that the region could be slightly polluted. Cluster analysis was indicative of oil origin for Ni and Cr.