Abstract:In order to solve the problem of "three sludges" in the treatment of oily wastewater from oil refinery, a strain GJ was isolated from the oily sludge of Daqing Oilfield, which produced surfactant and degraded petroleum hydrocarbon. Through morphological observation, physiological and biochemical experiments and 16S rDNA sequence analysis, the strain GJ was identified as Shewanella sp. The strain GJ was applied to the degradation experiment of scum and biochemical sludge, and the degradation kinetics of scum and biochemical sludge by GJ was discussed. After extraction and purification, TLC and FTIR analysis, it was confirmed that there was a five membered ring lactone structure and glycosidic bond in GJ product, which was a glycolipid surfactant. In the experiment of scum and biochemical sludge degradation, the degradation rate of petroleum hydrocarbon reached 81.11% and 83.21% respectively at the 7th day of strain GJIn the scum degradation test, the petroleum hydrocarbon degradation rate of strain GJ reached 81.11% on the seventh day, and 83.21% on the seventh day of biochemical sludge degradation test. Logistic growth model (R2 = 0.972), luedeking piret model (R2 = 0.985) and first-order reaction kinetics model can simulate the growth of GJ cell, the synthesis of surface active products and the degradation of petroleum hydrocarbons. It is preliminarily inferred that GJ bacteria take petroleum hydrocarbon as carbon source, and secrete surfactant at the oil-water interface during the growth process, increase the contact degree between the strain and petroleum hydrocarbon, and promote the uptake, metabolism and self proliferation of GJ bacteria. This paper can provide a theoretical reference for the study of the mechanism of petroleum hydrocarbon degradation by Shewanella spp. and its engineering application.