Abstract:

        Taking the crude oil as the typical pollutant, this paper obtains four high-effect oil-degrading bacteria which are selected from the many oil-degrading bacteria which have been screened and preserved by our previous experiments，then carries out a random mixing on these four bacteria(coded as A,B,C and D) to build a predominant bacterial consortium to degrade crude oil. The results show that the ability to degrade petroleum of community A-C-D is the best, and the degeneration rate is up to 39.67% in three days, with a increase of 13.21% compared with that of the single fungus; and the best inoculation ratio of community A-C-D is 1∶2∶0.5 with degradation rate of 27.8% to 44.2% in different vaccination proportions in three days. Finally, considering synthetically the concentration of nitrogen and phosphorus, minute ventilation volume, electron acceptor and so on, which are environmental influence factors of bioremediation, a orthogonal test is carried out to identify the optimum condition for bioremediation of community A-C-D, as C∶N∶P is 75∶8∶3, the contents of surfactant and H₂ O₂ is 0.5% and 1.5%, respectively, and six gauzes for ventilation. Under this condition, the degradation rate of crude oil reaches to 61.46% in three days, with an increase of 56.76% compared with that of natural conditions(4.7%), and with an increase of about 17% compared with that of community A-C-D in the best inoculation ratio(44.2%).

Key words:  oil contamination, bacterial consortium, bioaugmentation, degradation