| Biotreatment of VOCs is a nearly developed method.This paper is finished based on the biofiltration. In the experiment the ethylbenzene is selected as the agent and the pellets as filters,we cultivated ,acclimatized and screened the germs and then we got dominant species and inoculated them into filter to grow membranes so that the ethybenzene can be degradated.The results show that the ethylbeneze degradation efficiency is related to the filter's altitude. The higher the filter is, the better the efficiency is, and the ethylbenzene concentration becomes lower. However, the higher the filter is, the more obvious the pressure drop is ,and the cost becomes more. The biofiltration degradation efficiency has good results in low ethylbenzene concentration and medium ethylbenzene concentration. But to higher concentration the results are not as good as the lower ones and medium ones. The higher the flow is, the shorter the residence time is, and vice versa. When the residence time is long, the germs have enough time to degrade and absorb VOCs, So the efficiency is high. Usually,the inlet volume removal load is maximum and the outlet volume removal load is minimum. The filter's volume removal is lower with the filter's higher attitude. The reason is that the inlets have thicker biological membranes. The greater the specific surface areas and the higher the porosites the pellets have , ,the better the degradation efficiencies are ,and vice versa. With the biological membranes'growth and accumulation ,it is easy for the filters to be clogged and the sprinkling can't pass through the filters. In result, the pressure drop becomes bigger and bigger .Carbon dioxide concentration becomes bigger with ethylbeneze's biological degradation; and the moisture is within 30%-50% .Surfactant is beneficial to the degradation .The best working conditions are that pH is 7 and the temperature is 25 C.
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