Abstract: Thickened oil causes inevitably the serious contamination of edatope and impacts human health and environment in its mining, storage, transportation, refining and using process. It is necessary to take effective measures for improving soil contaminated by thickened oil. The microbial screened consortium KL9-1 was used to research the bioremediation for improving soil contaminated by thickened oil, and the factors in the biodegradation progress were studied. The results showed that the pH value, inoculum size, soil N/P, surfactant dosage, tillage frequency, watering frequency and raising agent affected significantly the bioremediation. In the soil contaminated by thickened oil per kilogram, the initial conditions of pH of 8.0, inoculum of 70.0 mL, N/P of 3∶[1 and surfactant dosage of 4.0 g were controlled, the soil was watered every two days and plowed every four days, rice husks were used as a raising agent, and the petroleum hydrocarbon degradation rate could be as high as 54.07% after carrying out a biodegradation for 70 days.

Key words: font-family: 宋体, mso-bidi-font-family: 宋体, mso-font-kerning: 1.0pt, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, soil')">mso-bidi-language: AR-SA">soil, ')">contaminated by thickened oil, ')">hydrocarbon degrading bacterium, bioremediation