University Of Tehran Press Pollution 2383-451X 3 4 2017 10 01 Bioremediation of gasoil by indigenous bacterial strains 553 560 62772 10.22059/poll.2017.62772 EN Akbar Ghavidel Department of Soil Science and Engineering, University of MohagheghArdabili, P.O.Box 56199-13131, Ardabil, Iran Sumayyah Naji Rad Department of Environmental Science, Islamic Azad University, Ardabilbranch, P.O.Box 56157-31567, Ardabil, Iran Hosein Ali Alikhani Department of Soil Science and Engineering, University of Tehran, P.O.Box14155-6619, Karaj, Iran Journal Article 2017 04 04 Petroleum refining industries produce large amounts of toxic effluents, causing environmental pollution. Iran is an oil-rich country that encounters oil pollution in its soil and water. Bioremediation of these pollutants is an appropriate solution to tackle them, compared to physical and chemical remediation methods. There are some factors that increase the rate of biodegradation; therefore, this study aims to determine the rate of gasoil bioremediation by two indigenous bacterial isolates (from oil-contaminated soils of an oil refinery south of Tehran) in two different media, namely soil and soil-sawdust mixture. The two superior indigenous bacteria has been isolated through three steps with results indicating that in an optimal environmental condition (temperature= 27±2 °C, humidity of 60%, water holding capacity, and daily manual aeration), bacterial isolates are able to degrade about 78.87% and 93.53% of gasoil during 45 days in soil and soil-sawdust mixture media, respectively. These results imply the role of sawdust in improving aeration, water holding capacity, and-consequently- increasing bioavailability of gasoil to bacteria. https://jpoll.ut.ac.ir/article_62772_94bfb164e793f0ce1797d211c807f55b.pdf