Technical Study On The Treatment Of Oily Sludge By Petroleum Degrading Bacteria

Oily sludge is solid waste generated during oil mining,production,transportation and storage.It has a large amount of production and is highly hazardous.The purpose of this study is to use oil-degrading bacteria to strengthen the composting method to treat oily sludge and achieve harmlessness.After enrichment,separation,and screening for bacteria that can efficiently degrade petroleum hydrocarbons,physiological and biochemical identification and 16 SrDNA identification confirmed the species of strains.Orthogonal experiments were used to obtain high-efficiency decomposing rate bacteria,and the environmental adaptability of microbial degradation of petroleum hydrocarbons was studied.The degradation characteristics of petroleum hydrocarbons by bacteria were analyzed by GC-MS.The bacterial sludge was used to treat the oil sludge in the bottom of the tank with composting,and the effects of inoculum size,addition of surfactants,and nutrient substances on stacking efficiency were studied.Monitor temperature,pH,biomass,crude oil degradation rate over time.Eight strains with high degradation efficiency were screened.It was identified that T1,T2,T3,T4,T7,and T8 belong to Pseudomonas,T2 and T7 belong to Pseudomonas aeruginosa,T3 belongs to Pseudomonas pseudomonas,T5 belongs to Citrobacter,and T6 belongs to Bacillus..The optimal combinations of bacteria were T1,T2,T6,T7,T8,and T9.The inoculation ratio was 1:1:1:2:1,and the crude oil degradation efficiency was 46.65%.The optimum temperature for the flora was 30°C,the optimal inoculum size was 16%,the optimal salt content was 1%,and the optimum initial pH value was 7.All degradation conditions were set under the optimum conditions,and the bacterial colony degradation efficiency was measured as 50.38%.The microbial community has high degradation efficiency for straight chain alkanes,partially branched chain alkanes,and cyclohexane in saturated hydrocarbons.The bacteria also have high degradation efficiency for methyl naphthalenes,ethyl naphthalenes,biphenyls,furans,and terpenes in aromatic hydrocarbons.In the early stages of bacterial-enhanced composting,the greater the inoculation volume,the higher the oil degradation rate and the greater the biomass.In the later stage of stacking,the oil degradation rate and biomass were basically at the same level for different inoculum volumes.The oil degradation rate can reach up to 40.89%.After the stacking process,the pH of the sludge decreased,and the change trend was consistent.With the addition of surfactants,the oil degradation rate is high,which is as high as 39.30%,and the biomass is also large.After stacking,the pH value decreased even more.The addition of water-soluble nutrients increased the oil degradation rate in the experimental time range,reaching 40.27%,the biomass increased more significantly,and the pH value also decreased significantly.