Study on Screening Method of Bio-demulsifying Microorganism from Activated Sludge and Characteristic

Bio-demulsifier as a biological agent will become a substitute of chemical demulsifier for its high efficiency, low cost, high adoptability and environment friendly. In this paper, a set of high efficiency, rapid and simple method was established to isolate de emulsification strains. Blue-gel plates test, oil agar plates test, oil-spreading test and demulsifying test were combined used in this method. Using this method, ten strains with high de-emulsification capability which the demulsifying ratios in O/W Kerosene emulsion (in 24h) were more than 50% were primary screened from activated sludge samples. Two highly efficient demulsifying strains which the demulsifying ratio in O/W Kerosene emulsion (in 24h) were more than 90% were secondary isolated and identified as Gordonia sp through 16S rDNA gene and physiological test. The whole culture of the strain appeared very high deemulsification activity with low biomass.