Biosurfactant Effect On Microbial Degradation Of Heavy Oil.

There are many factors influencing the biodegradation of petroleum,but how many factors affect the degradation process is the difficult and weak point.This article is based on the orthogonal and Box-Behnken experiment,discussed 10 kinds of common oil degradation bacteria and biosurfactant?Surfactin?impact on the microbial degradation of petroleum,established an experimental method to optimize the degradation of heavy oil.GC-MS was used to analyze the degradation degree and parameter variation of heavy oil in biosurfactant,and the changes of the polar compound before and after degradation were analyzed by ESI FT-ICR MS.Finally,the effects of biosurfactants on the microbial degradation of heavy oil heteroatomic compounds were explored through the degradation experiments of hetero-atomic compounds in typical petroleum.The study found that:?1?.Biosurfactants are the most important influencing factors in the process of biodegradation of oil,which can significantly affect the oil degradation rate?P<0.05?.Bacterial species are the main influencing factors for biodegradation of petroleum saturated hydrocarbon components,but for aromatic,colloidal and asphaltic components,biosurfactants are the most important factors affecting their degradation.In this study,Bacillus amyloids and Pseudomonas aeruginosa played an important role in the process of oil degradation,which are the best degradation bacterias of this experiment.In addition,the addition concentration ratio of different strains and biosurfactants has important effects on petroleum degradation.In this experiment,the5%?v/v?adding amount of bacterial and 200 mg/L of biosurfactant products effect best,the theory of case 25 d highest degradation rate can reach 63.78%.The orthogonal and box-behnken tests were used to screen the best degradation bacteria and the optimal strains with the advantages of more analysis factors,less experiment and good compatibility of bacteria,and had better application prospects.?2?.Adding biosurfactants can improve the microbial degradation level of petroleum.Biosurfactant is added in the experimental period for the promotion of degradation of corresponding normal alkanes was obviously,make C₂₇,C₂₈ and C₂₉sterane relative contents change obviously,but hopane series compounds relative change is not obvious.P and MP are the most obvious parts of the heavy oil aromatics in this experiment.The parameters reflect the sensitivity of the oil degradation degree from high to low is normal paraffin parameters>Aromatics parameters?Phenanthrene series and dibenzothiophene series?>Sterane parameter>Hopane parameter,among them,the changes of Pr/nC₁₇ and Ph/nC₁₈ were most obvious.?3?.The content of polar compounds in petroleum was significantly changed after microbial degradation.After oil degradation N1 and N1O1 class material content significantly decreased,O1 class material content increased to a certain extent,but add biosurfactant experimental content is reduced,illustrate the promotion biosurfactant O1class material degradation.The content of O2 was reduced,but its relative content increased,while the content of O3 and O4 compounds increased obviously,indicating that the microbial degradation could increase the oxidation of heavy oil.The addition of biosurfactants can promote the degradation of N1 substances by microorganisms,and produce a lot of N1 materials with low unsaturation?DBE<9?,and the carbazole of DBE=9 is relatively weak in combating microbial degradation.After degradation,the content of sterane acid in the O2 class was reduced obviously.After adding the biosurfactant,the distribution of the carbon number of the O2 class was more extensive,resulting in a lot of low carbon number?<14?,which promoted the decomposition of the O2 material.?4?.Brucella melitensis can degrade typical polar compounds in petroleum.The addition of biosurfactants can improve the degradation of the polar monomers with the increase in the degradation rate of carbazole.The degradation rate of carbazole was increased by 52.33%and the degradation rate was 97.27%.Adding biosurfactant can promote microbial metabolic process and improve biomass.Add biosurfactant group detected a lot of small molecular compounds and have a lot"UCM"peaks,it could be a product of microbial metabolism..