The removal of organic pollutants and ammonia nitrogen by domestic sewage treatment equipment mainly depends on AO biological treatment process in the equipment. The working principle is in grade A. Because of the high concentration of organic matter in sewage and the hypoxia of microorganisms, microorganisms are facultative microorganisms at this time. So the grade A pond not only has a certain function of removing organic matter, but also reduces the organic load of the subsequent aerobic pond and reduces the concentration of organic matter, but also has a certain amount of organic matter and higher NH3-N. Existence.
In order to further oxidize and decompose organic matter, and nitrification can proceed smoothly under carbonization, an aerobic biological contact oxidation tank with lower organic load is set up at O level.