Study On Biofilm Immobilization Of Two Symbiotic Petrophilic Bacteria And Treatment Of Oil Production Wastewater

The quality of oil production wastewater fluctuates,the suspended solids content is high,the mineralization degree is large,and harmful ions and organic components are complex.At present,most of China's oil fields have entered the stage of secondary oil recovery and tertiary oil recovery.The resulting oil production wastewater is increasing day by day,and the amount of water is large and the water quality is poor.There have been many reports on the efficient degradation of petroleum hydrocarbons,but few studies have been applied to actual oil recovery wastewater treatment.In the early stage of the research group,a strain of Pseudomonas aeruginosa NY3 was isolated and identified.The immobilized biofilm had good treatment effect on high-concentration and low-concentration oily wastewater.Based on the previous research,this article uses infrared,gas chromatography,scanning electron microscopy and other analytical methods to explore the application of immobilized biofilms of NY3 bacteria in the treatment of actual oil recovery wastewater,and a Rhodococcus erythropolis on the surface of the membrane.FF crude oil degradation ability and environmental adaptability were studied.The main result is the following:(1)NY3 bacteria biofilm has good treatment effect on actual oil recovery wastewater.For high salinity and partial acidic,actual oil recovery wastewater with a crude oil loading of 240 mg/g carrier ?d,the average degradation rate of oil in the wastewater can reach 89.1% at a hydraulic retention time of 2 h.Nitrogen and phosphorus are added appropriately.The source can also further improve the degradation of oils in wastewater.After the operation of the NY3 biofilm,under the conditions of aerobic aeration,the petroleum hydrocarbon degradation capacity is better than before recovery,and the oil concentration in the outlet water is lower.(2)When NY3 bacteria biofilm is used to treat actual oil production wastewater,it can be combined with some indigenous people in the wastewater to form a symbiotic colony on the surface of the biofilm.After separation and purification,Rhodococcus erythropolis FF with strong degradation ability of crude oil was obtained.When the ratio of FF bacteria to NY3 bacteria was 1:1 or FF bacteria dominated,the degradation efficiency of crude oil was higher,and the co-immobilized biofilm was also more efficient than the single NY3 bacteria-immobilized biofilm.(3)FF bacteria can effectively degrade high-salt and high-concentration oily wastewater under the partial acidic conditions.When the pH of the wastewater is 6.0-6.5,the free FF bacteria can remove 83% of the 2 g/L oil within 24 h;when the wastewater contains salt in the range of 0-12 g/L,the free FF bacteria can When about 80% of the oil is removed,even when the salt content is as high as 30 g/L,the petroleum hydrocarbon degradation rate is still 60%;addition of ammonium nitrate and trehalose ester can increase the petroleum hydrocarbon degradation rate of the FF bacteria,and in the waste water With 2 g/L oil,the removal rate is higher than 95%.(4)Rhodococcus erythropolis FF can be efficiently fixed on the polyurethane porous material,and the biomass after fixation can be as high as 437 mg/g.The biofilm can rapidly and efficiently degrade petroleum hydrocarbon pollutants under high salt and weak acid conditions.The results of the study on the composition of undegraded crude oils show that the removal efficiency of alkanes,aromatics and asphaltenes in crude oils by FF bacteria is particularly prominent.The above research results are very important for the application of NY3 bacteria and FF bacteria in the actual wastewater treatment,and can provide theoretical guidance for the biological treatment technology of actual oil recovery wastewater.