Petroleum hydrocarbon assessment in the wastewaters of petrochemical special economic zone and sediment benchmark calculation of the coastal area - northwest of the Persian Gulf

Petrochemical industries can potentially impact the environment due to their activities and products. This case study has considered adverse effects of petrochemical industries that are located inside the PETZONE with respect to the presence of polycyclic aromatic hydrocarbons and total petroleum hydrocarbon in wastewater effluents. The average concentrations of ∑PAHs group I and II were lower than the guideline values, thus the effluents of the study area can be considered unpolluted. Also, the average concentration of TPH was lower than the guideline value at all almost stations exceptthe effluent outlets of the Razi and Imam Khomeini petrochemical (BI-PC) companies which are proximal to Khowr-e Musa Bay. Thus, they may have an adverse impact on the aquatic ecosystem of the Bay. Therefore, the concentration of TPH was monitored in the sediments of the Bay (around the PETZONE coastal area) which wasrelatively moderate compared in the study area. Also, the sum ofChronic Potency Ratioof PAHs in sediments showed that the chronic benchmark was not more than the guideline at all stations (it is exceeded when the sum exceeds 1.0) except in the vicinity of the Aromatic effluent outlet of BI-PC.Thus, the chronic benchmark at this station indicates that it has the potential to cause a chronic effect on sediment-residence organisms like crabs, clams and worms. Moreover, PAHs concentration level in this station approached the NOAA sediment quality guideline value (ERL) of 4000 (ng/g dry weight).