Study On The Hydrocarbon Degrading Bacteria And Degrading Characteristics From Oil Contaminated Soil Of Kelamayi Oilfield

Karamay Oil Field was the country’s largest oil field before the development of the Daqing Oil Field. The rapid development of the oil industry has brought a number of environmental issues. Petroleum-contaminated soil problem is especially severe. Microbial remediation technology is acknowledged to be one of the most promising petroleum-contaminated soil treatment technology.The physical and chemical properties, microbiological properties of petroleum-contaminated soil of 10 stations in Karamay were investigated. The results showed that, the moisture content of Karamay oil-contaminated soil is very low. Soil is alkaline and has low level of nutrition. There are some differences in enzyme activities of soil, but generally low.Several enrichment and purification of petroleum hydrocarbon degrading bacteria was carried out in petroleum-contaminated soil of 10 stations in Karamay. Finally, 6 kinds of degrading bacteria, whose degradation rate were all above 35% at 45℃.（ the 6 degrading bacteria were named KL3-5,KL8-2-43,KL3-21,KL34-26,KL2-15 and KL2-13, respectively.） were obtained; KL3-21 was identified as Pseudomonas putida through the tests of morphological, physiological and biochemical characteristics and the analysis results of 16S rDNA sequence.The effect of environmental factors to petroleum hydrocarbon degrading bacteria KL3-21 was investigated. The results showed that, degrading bacteria KL3-21 has an optimum pH range of 6 8. The optimum inoculation quantity is 3%. The Fe²⁺,Mg²⁺ and Ca²⁺ with low concentration can improve degradation ability for degrading bacteria KL3-21. Too low concentration of the tween-80 has not obvious promotion to degrading bacteria KL3-21. Too high concentration can decrease its degradation ability. The best dosage is 2%.Furthermore, the degradation characteristics of bacteria KL3-21 to petroleum hydrocarbon model properties were studied. The results showed that bacteria KL3-21 has the best degradation ability to n-hexadecane and toluene（after 30d,the degradation rate is up to 99.53% and 99.77%, respectively）; the degradation ability to catechol and naphthalene are followed by the n-hexadecane and toluene（after 30d,the degradation rate can reach 80.92% and 87.23%, respectively）; while the degradation ability to pyrene is lower than others. The degradation rate can only achieve 23.70%.Finally, the indoor pot experiment of oil polluted soil was carried out. The feasibility of indoor bioremediation experiments on Karamay oil-contaminated soil was analyzed and the launching conditions of bioremediation were explored. The results showed that, the main factors of affecting bioremediation are dosage of antimicrobial, moisture content, and chicken manure. The orthogonal experiment showed that the optimal launching conditions of bioremediation experiments to Karamay oil-contaminated soil is as follows: antimicrobial dosage 200mL, moisture content 15%, chicken manure dosage 120g, bran dosage 50g, the surfactant 30mL.