| The bacteria were selected and cultivated from native, then the bacteria were transferred to the packing in the elimination system-biotrickling filter. The elimination of low concentration toluene from gas stream had been investigated in the biotrickling filter to find out the relatives among elimination efficiency and concentration and gas flux etc. On the base of the theory of adsorption-biodegradation, a dynamic model was built for biotrickling filter in dealing with toluene, and the model equations were solved numerically. The researching results indicated that: According to the increasing of the inlet toluene concentration from 0.1mg/L ~9.2mg/L, the elimination capacity increased gradually up to 81.0mg/(L . h), the upper part of the filter performed better in eliminating toluene than the lower part did. When the inlet toluene concentration was less than 5.3mg/L, a elimination efficiency of greater than 93.8% was obtained. Continuing increasing the inlet toluene concentration, the elimination efficiency decreased gradually. When the retention time was lower than 2.4min, with the increasing of the retention time, the elimination efficiency increased rapidly. When retention time increased to 2.4min, the elimination efficiency was up to 94.2%. Keeping on increasing the retention time, the elimination efficiency maintained in higher level and varied little. A batch of nutrients liquid could offer about ten days running with high efficiency. Given sufficient nutrients did the biotrickling filter system degrade toluene efficiently. With the increasing of the gas flux, the pressure drop increased, when the gas flux was up to 560L/h, pressure drop reached 978.6Pa. The longer the stopping time was, the more the elimination efficiency decreased, the longer time was needed for the biotrickling system to refresh. Having compared the model predicted results with the experimental results, it was found that the model predicted profiles agreed very well with experimental data.
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