Isolation Of Degrading Bacteria With Potential For Oil Biodegradation From Oily Sludge And Applied Basic Research

The oily sludge can be generated from the petroleum industry during its crude oil exploration, production,transportation, storage, and refining processes, Oily sludge is one of the most significant solid wastes generated in the petroleum industry. It is a complex emulsion of various petroleum hydrocarbons (PHCs), water, heavy metals, and solid particles.The constituents in oil include:n-alkanes, branched alkanes,cycloalkanes, polynuclear aromatic hydrocarbons,nitrogen,sulphur and oxygen containing heterocyclics, asphaltenes, and resins. Various n-alkanes, branched alkanes and cycloalkanes are known to cause respiratory, renal and central nervous system disorders. The low molecular weight PAHs are commonly associated with acute toxicity while the high molecular weight polynuclear aromatic hydrocarbons (PAHs) are reportedto be mutagenic and carcinogenic. As being recognized as a hazardous waste in many countries, the improper disposal or insufficient treatment of oily sludge can pose serious threats to the environment and human health. Due to its hazardous nature and increased generation quantities around the world, the effective treatment of oily sludge has attracted widespread attention. Owing to the diverse physical properties,a variety of oily sludge treatment methods have been developed,such as incineration, solidification/stabilization,solvent extraction, ultrasonic treatment, pyrolysis, photocatalysis,and chemical treatment. Many of these physical and chemical technologies are either costly or do not result incomplete decontamination. In contrast, biological treatments (bioremediation) appear to be among the most promising methods for dealing with a wide range of organic contaminants, particularly petroleum hydrocarbons. Biological techniques may also be environmentally friendlier by simulating natural processes.so our study choose Biological techniques to treat oily sludge.The indigenous oil-degrading bacterial consortia was isolated from oily sluge. The consortia were purified on BPDA medium.we got 3 strains from the consortia.An analysis of 16S rRNA was performed to taxonomically characterize the isolated strains. Three strains exhibited the highest oil degradation capability.Finally,we use the consortia to wash oily sludge.(1) With the change of time and pH,The crude oil removal assay was carried out When 10 mL (10%) inoculum was transferred to 250 mL shaking flasks with 50 mL petroleum degrading media (MSM plus crude oil) After 6 d, the oil content was degraded to 63% by the consortium. When pH is above 3,the degradation rate of crude oil increased significantly as pH increased; When pH is 11, the degradation rate of crude oil is the highest.crude oil biodegradation were analyzed using a spectrometry method, the consortia exhibited better degradation for petroleum hydrocarbons with medium-length chains (C6? C30).(2) An analysis of 16S rRNA was performed to taxonomically characterize the isolated strains. The members of the small consortia were identified as Porphyrobacter cryptus? Staphylococcus epidermidis and Pseudomonas aeruginosa.3 strains of crude oil removal assay was carried out. We discussed the factors influencing the hydrocarbon degradation of 1 strain.(3) oily sludge is degraded by the consortia.After 6 d, the oil content was degraded above 63%; oily sludge is washed by the consortia. After 86 h,the rate of recovery oil is 48%.