Screening Of Oil Petroleum-degrading Strains And Construction Of The Mixed For Bioremediation Of Petroleum-contaminated Soil

Petroleum has been widely used around the world as an important energy source, because of the oil exploration, development, transportation and refining process, which caused severe pollution to the oil fields and farm land. At present, bioremediation technology which is economic, rapid, and no secondary pollution has become a new reliable soil remediation technology and an important research field toward petroleum contaminated soil.In this paper, by using petroleum-contaminated soil collected from Northern Shaanxi petroleum hydrocarbon as degrading bacteria bacteria source, and inorganic salt and Bush-Hass medium as initial screening media, the beef extract peptone medium as seconds creening medium, 17 strains were obtained by streak plate method. The 16 S r RNA sequence analysis is used to identify the strain. The physiological and biochemical properties of strains were determined. Then build the degradation effect is good mixture system, and will be adding the mixture into the oil pollution soil treatment the experimental comparison. During the repairperiod, research the oil degradation rate of petroleum hydrocarbon residues in soil and their week changes, microorganism quantity, soil catalase, dehydrogenase, soil carbon nitrogen and phosphorus than change and determined different components of petroleum hydrocarbons changes. Through research to determine the relationship between the key factors effect and hydrocarbon degradation efficiency and among the indexes.Results indicated that:From the two different species of Northern Shaanxi oil soils creened 17 strains of petroleum degrading bacteria, one except for gram positive bacteria strains, the rest are gramnegative bacteria. Analysis appraisal, bacteria content belong to the Ochrobactrum, Pseudomonas aeruginosa, Bacillus fusiform, Pseudomonas, Bacillus spindle, Acinetobacter, Alcaligenes colorless. In the 17 bacteria, Pseudomonas aeruginosa SQ-2 on the oil degradation best, in the aqueous phase through 14 d degradation of petroleum hydrocarbon degradation rate of 73.82%.When the bacteria Pseudomonas aeruginosa SQ-2 as a main degrading bacteria and Pseudomonas SQ-4 and fungi SQ-Z2 together to build a mixed flora; and a colorless Alcaligenes T2 as the main degrading bacteria, and two Pseudomonas T3?SQ-4 together to build a mixed flora of hydrocarbon-degrading better, to the aqueous phase petroleum hydrocarbon degradation rate 7d can respectively reach 53.46% and 45.67%.The used of different treatment options for remediation of petroleum contaminated soil. The results showed that compared with oil and natural state of the soil, trickle carbon phosphorus is better than the adding bio-stimulation and bio-dosing mixed culture strengthen petroleum hydrocarbons in soil degradation plays. Continuous adding carbon nitrogen and phosphorus nutrition on biological stimulation works best. Therefore soil C / N / P ratiois a major factor in Northern Shaanxi oil repair of contaminated soil organisms.The measurement results of the hydrocarbon-degrading bacteria in soil showed biostimulation and bioaugmentation effect can make the soil in the increased number of hydrocarbon-degrading bacteria and alkane degrading bacterium, and the number of petroleum hydrocarbon-degrading bacteria degradation rate was significantly correlated.The measurement results of the bio-stimulation of the different components of soil with petroleum hydrocarbons indicate that the repair process carbon number C13-C30 saturated hydrocarbon content is reduced, where in the carbon number C13 saturated hydrocarbons can be completely removed, the carbon number of the saturated C14-C16 higher hydrocarbon removal, the relatively low number of carbon atoms is higher than for the removal of saturated hydrocarbons 17.Adding C6H12O6 and 3% H2O2 to fix the lag in soil, can promote soil petroleum hydrocarbon residues lag further degradation. Adding C6H12O6 cometabolic base for petroleum hydrocarbon removal rate 74.91% is better than the adding 3% H2O2 petroleum hydrocarbon compound oxide removal effect.