Screening For Polycyclic Aromatic Hydrocarbon-degrading Bacterium And Emediation Of Naphthalene-contaminated Soil With Biochar Immobilized Microorganism

Polycyclic aromatic hydrocarbons(PAHs)including naphthalene,anthracene and pyrene.The potential toxicity action of naphthalene aroused people’s wide attention.The accumulation of naphthalene in the environment will cause cancer,birth defects on the human body.At present,the petroleum chemical industry production of naphthalene has led to the pollution of soil.With the advantages of efficient environmental protection,microbial degradation can be used as an effective method of eliminating naphthalene pollution.Soil samples in the ten areas were collected from Jinshan petrochemical area in Shanghai.More than one hundred kinds of strains,which can resistant naphthalene,were collected.We found that the number of strains that can tolerate naphthalene can be divided into two gradients: the first gradient strain for the degradation of naphthalene is: 3 × 104 ~ 6.3 × 106 CFU/g,the second number of strain gradient is: 6 × 109 ~ 2.5 × 1010 CFU/g.Through the analysis of 16 S rRNA,found that the three strains of bacteria respectively belong to Sinomonas sp.,Ralstonia sp.and Klebsiella sp.Through the inquiry experiment to get the strain growth and naphthalene degradation rate,the dehydrogenase activity,two-plus oxygen enzyme activity at the 0.1 level.It proved that with the strain growth,dehydrogenase activity,oxygen two-plus enzyme activity characterization of microbial degradation ability of organic pollutants is a reliable method.Researching the impact of different concentrations of PAHs in naphthalene degradation strains(Sin4 and XTB5),which indecated that the strain Sin4 and XTB5 can grow in the concentration of 25 ~ 200 mg/l of naphthalene,anthracene and pyrene grow medium.Compared with Sin4,the strain XTB5 can be more tolerated PAHs.In the concentration of the nap(50 mg/l),ant(50 mg/l)and pyr(25 mg/l),the strain XTB5 show better tolerated.we found that the strain XTB5 is effected by the PAHs rings.The exploration of different strains of atrazine degradation potential shows that the strain XTB5 of atrazine has certain tolerance and is likely to grow as a source of carbon and nitrogen source of energy.In addition,strain sin2 and sin4 can grow in the medium with atrazine.Screening strains with potential of degradating a variety of pollutants such as the HAPs,atrazine is the key to breakthrough the environmental pollution problem.The strain of XTB5 mixed with specific biological carbon respectively and again with sodium alginate,made by XTB5 for the main function of strain biochar immobilized bacteria agent.Then under laboratory conditions,use the bacterium agent for repair of naphthalene contaminated soil.Results show that three days later,three treatment group of naphthalene removal rate reached75%,96%和 67% and the urine of contaminated soil enzyme activity respectively increased by 19.1%,81.6%和45.7%,dehydrogenase activity were decreased by 15.1%,19.7%,13.6%,polyphenol oxidase activity were decreased.The pH value of polluted soil and protected water were increased.It illustated that the bacteria agent not only can deal with the naphthalene degradation of soil,also can improve the soil enzyme activity.These studies for practical application of microbial remediation of naphthalene contaminated soil laid a foundation.