A considerable part of the dissolved organic pollutants in the sewage can not be removed by physical and chemical methods, and the biochemical treatment process must be used to degrade the dissolved organic pollutants. At present, the biochemical treatment process is used as the main body of the activated sludge process of the dissolved air flotation machine. The method is mature and has a high removal rate of organic pollutants in the sewage.

Activated sludge as spawn, the activated sludge SV30 was 15 ~ 20%, the sludge concentration of MLSS was 2.5 ~ 3g/L, and the activated sludge was inoculated into the activated sludge aeration tank. In the aeration tank, the 500mg/L concentration of the sewage in the aeration tank is controlled by the aeration tank, and then the CODcr concentration in the aeration tank is controlled. Bored 5 ~ 3 days after the start of a small amount of water, every day to detect the CODcr concentration and sludge SV30 aeration tank.

Aeration tank mixed liquor by the sedimentation, the supernatant was discharged into the set in the well, no sludge discharge, so that after a period of cultivation and domestication, the activity of the sludge enhanced, condenses, good subsidence performance, aeration tank mixed liquor after 30 minutes to precipitate, sludge settling ratio 30%. The supernatant was clear and transparent, suggesting that activated sludge has been grown in culture, can be put into normal operation.