A laboratory scale study was conducted to investigate the effect of temperature on bioremediation of crude oil
contaminated soil. The initial crude oil concentration in the soil was determined to be 38,075 mg/kg of dry soil. The
contaminated soil mixed with either urea (as an inorganic amendment), hydrocarbon degrader bacteria plus urea or with
wastewater activated sludge (as an organic amendment and microbial flora) was incubated at either 25°C or 45°C for 12
weeks A contaminated soil with no amendment was used as a control. The total petroleum hydrocarbons (TPHs) removal
observed regardless of the added amendments was 79.8% and 62.4% at mesophilic and at thermophilic temperatures,
respectively. The maximum TPHs removal was obtained with the contaminated soil treated with urea plus hydrocarbon
degrading bacteria. The lowest TPHs removal (