Study of Soil Pollution with Heavy Metals due to Leakage of Petroleum Hydrocarbons at Kermanshah Refinery

In recent decades, soil pollution with petroleum hydrocarbons in oil-rich countries (such as Iran) has been one of the most challenging issues. In these countries with petroleum industries, mines of oil exploration, refineries, etc., leakage from tanks or pipelines of oil transmission due to corrosion and damage bring about oil pollution for the soil. This study aimed at evaluating and measuring the amount of heavy metals in the soil of Kermanshah Refinery and statistical analysis in order to locate high-risk areas in terms of pollution caused by oil leaks, extraction, refining, and transportation. Therefore; 15 samples of surrounded soil of Kermanshah Refinery were analyzed to determine soil pollution with petroleum compounds. According to results of ICP-MS analysis of soil samples, the process of heavy metal changes in the soil of Kermanshah Refinery was Cr>Zn>Ni>V>Cu>Pb>Co>Sc>As>Cd. Geo accumulation index indicated that the intensity of the refinery soil is classified in the range of no pollution to average with reference to chromium and nickel. Besides, the finding from enrichment factor indicated the average enrichment of the region soil by chromium and lead. Moreover, it confirmed that enrichment in lead and copper has anthropogenic origin. Pollution load index of chromium, nickel, zinc, copper, and lead showed soil pollution to these metals. Zoning map of heavy metal density in the region soil demonstrates that high density of the elements in some stations is related to the petroleum leakage from installations and storage tank.