2. Aerator. The aerator directly injects "micro bubbles" into untreated sewage through the diffusion impeller. Under the joint action of coagulant and flocculant, suspended solids undergo physical flocculation and chemical flocculation to form large suspended solid flocs, which float to the liquid surface to form scum under the floating action of bubbles, and are separated from water by a slag scraper; There is no need to clean the nozzle, and no blockage will occur. The equipment has good integrity, convenient installation, saving operation cost and occupying less land.
3. Microfiltration machine. Microfiltration machine is a drum screen filtration device. The treated wastewater enters the drum along the axial direction and flows out through the screen along the radial direction, and impurities (fine suspended solids, fibers, paper pulp, etc. ) is trapped on the inner surface of the screen on the drum. When the impurities trapped on the filter screen are carried to the upper part by the roller, the pressure washing water is backwashed into the slag discharge tank to flow out. During operation, 2/5 of the drum diameter is exposed out of the water, and the rotating speed is 1-4r/min. The filtration speed of the screen can be 30- 120m/h, the washing water pressure is 0.5- 1.5kg/cm2, and the washing water volume is 0.5- 1.0% of the raw water output. The microfilter occupies a small area, has a large production capacity (250-36000m3/d) and is convenient to operate and manage. It has been successfully applied to water supply and wastewater treatment.