Background and purpose: Petroleum hydrocarbons are one of the most common persistent organic pollutants in the environment. Phytoremediation is a new technology in which the resistant plants are used to remove or reduce organic and mineral contamination and hazardous environmental substances. The purpose of this study was to evaluate the effect of Vetiveria Zizanioides plants on total petroleum hydrocarbons (TPH) removal in soil contaminated by oil in different concentrations of oil pollution in Khuzestan industrial area.

Materials and methods: The soil samples were collected from the areas around Ahvaz oil field and were contaminated by oil in different concentrations (5%, 7%, and 10 % w/w). TPH measurement was done (and repeated twice) during four months in five retention time. Determination of TPH concentration in GC was performed using FID detector.

Results: According to the results, the best efficiency of Vetiveria Zizanioides in removal of TPH was found in treatment with 5% oil pollution (91%) during 120 days. Most changes in microbial population occurred in 7% oil pollution (106 × 9.78 CFU/g) in 120 days.

Conclusion: Vetiveria Zizanioides showed to be highly capable of removing TPH from contaminated soil.