| Chlorinated hydrocarbon compounds are widely used in chemical,pharmaceutical, pesticide areas, especially in electronic, automobile, machinery,printing, dry cleaning industries. It is toxic, chemically stable, hardly soluble in water,and hardly nonbiodegradable. Once into the environment, it has a long-term negetiveeffects for human beings and ecological environment. Trichloroethylene （TCE） isone of the most common pollutants. It is volatile and easily mobile into theunderground water through the soil infiltration.The study acclimated and screened a trichloroethylene degrading bacteria from acontaminated site in Beijing with a high concentration of TCE contamination in soil.Species identification experiments had been conducted to determine its taxonomicstatus, the optimal bacteria culture conditions for degradation explored, thedegradation of TCE, sodium acetate cometabolism, PCE and phenol are studied aswell. At the same time, the laboratory simulation column experiment was conductedto explore TCE degradation effects, to provide more accurate reference data andtheoretical basis for the bioremediation or biological treatment technology inenvironmental pollution.The results showed:（1）the bacteria was identified as Comamonas sp. theoptimum growth conditions for Comamonas sp. were pH8.3, temperature32°C andmaximum salinity tolerance6%.（2）the bacteria could achieve the best degradationeffect in a ratio of94.79%in10days at an initial concentration of5mg/L TCE withco-metabolism of500mg/L sodium acetate, while the degradation was inhibited at asodium acetate concentration above2500mg/L.（3） The TCE with an initialconcentration of more than10mg/L was not conducive to the degradation, because thestrains may be toxic. The degradation effect of other pollutants such as PCE andphenol was not apparent, and need further investigation.（4）The columnar simulationexperiment also achieved a good degradation effect,70%TCE degradation rate reached for sand column in10days’ degradation. |
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