The Development And Application Research On Low-Temperature Oil And Grease Degrading Composite Bacterium

This study aimed to develop a composite bacterium for efficient degradation of theoil and grease in restaurant wastewater at low temperatures and the performanceindicators of the composite bacterium were measured. Then, the laboratory test wasdesigned to determine its actual processing capacity and applying feasibility. Finally, theresults would be applied to assess its actual value and market prospect, through it wasused to practical engineering processing of test and user survey.The composite bacterium was composed of two low-temperature bacteria whichwere isolated from the sewage pipe in the school dining hall. They were the DJ-1andDJ-4strain, which were proved to be capable of effectively degrading the plant oranimal oil under low-temperature environment, respectively. After repeatedlyacclimation, having been used in treating simulated wastewater which was contained2000mg/L oil under5℃in the current study, the DJ-1could degrade70.63%of thegrease in simulated water mix with plant oil inocula, and DJ-4hold a capacity ofdegrade51.00%of grease in the animal oil simulated water mix with plant oil inocula.The DJ-1and DJ-4strains were proved to be an undecided species of Pseudomonas sp.by sequencing analysis.Separated out the DJ-1and DJ-4strains which were able to remove plant oil underlow-temperature environment, for DJ-1, the optimum growth temperature, pH value androtation speed respectively was,10°C,7.0, and140r/min. and for DJ-4, the optimumgrowth temperature, pH value and rotation speed respectively was,10°C,8.0, and120r/min. When these two strains were used to deal with oil wastewater together, theoptimum processing temperature, treatment pH, initial grease concentration and rotationspeed of DJ-1strain respectively was10°C,7.0,2000mg/L and100r/min, and the aboveindicators for DJ-4strain respectively was10°C,7.0,2000mg/L, and120r/min.The low-temperature oil and grease degrading composite bacterium wascomposition by the DJ-1and DJ-4strains with the1:1complex. The compositebacterium could be used in treating simulated wastewater, which was contained2000mg/L pure plant oil, the degradation rate would attain to73.69%.and for thesimulated water which was contained2000mg/L the1:1mixed animal and plant oilwould be degraded68.80%, for pure animal oil in same dosage and condition, thecapacity of degrade is43.57%.The composite powder which was immobilized by the composite bacterium has, a60min recovery time, the optimum dosage of0.15g/L, andthe optimum processing time for3d.In the simulation of kitchen sewage pipes test, the composite powder was dosing tothe pipes. After3d treatment,69.4%of the grease in the simulation pipe could beremoved, and the the grease which attached on the pipe could be efficient removed. Thecomposite powder was dosing to the10L simulation grease trap with the dosage of0.15g/L. After3d treatment,84.3%of the grease in the simulation grease trap could beremoved in the maximum.The composite agent application test result was derived from obtaining kitchensewage pipes in the six larger catering companies and residential grease trap under low-temperature environment in winter period. As the result shows: this compositebacterium made the grease accumulated significantly reduced in the sewage pipes andgrease trap, and also had a better degradation effect in the restaurant wastewater underlow-temperature environment.The composite agent had better effect treatment on the pipeline greasesolidification phenomena of the low-temperature environment, through the user surveyresult and market analysis. The agent product had a higher acceptance rate of its users,and it was a grease treatment product used in low-temperature which had the advantagesof low productive cost, simple use, no secondary pollution and safety to environment,.So, should have a broad marker prospect and business value.