Waste fan, biogas compressor. Water seal tank and so on, sewage treatment of waste gas will be utilized twice to the high load aeration tank, the process is simple. Now the waste gas treatment method of small and medium-sized sewage treatment plant most of the pool cover method to deal with, but with the cover and corrosive gas concentration multiplied after its internal due to the pool, the sun radiation temperature is very high, the internal steel structure corrosion is extremely easy to be in the 2 ~ 3 years of general life. In order to solve the corrosion problem of steel bearing solution? In addition to fluorocarbon fiber membrane structure is a new structure of the cesspool building development, choose fluorocarbon fiber membrane as a cover material corrosion resistance, and through the form of suspension in the corrosive environment, adapted to the cesspool.