The main source of water for municipal sewage wastewater, people in our daily activities, mainly waste waste and wastewater, including the kitchen sink, shower, washing and toilet flushing sewage etc..
 

   Typical urban sewage treatment process flow group should include mechanical treatment, biochemical treatment, sludge treatment, etc.. The system which is composed of mechanical treatment and biochemical treatment belongs to the two stage treatment system. The removal rate of BOD5 and SS is up to 90%-98%. The general said the intermediate effect between grade one and grade two is the enhanced primary treatment, a semi processed or incomplete two level processing, mainly high load biological treatment method and Kazakhstan method in two categories, the removal rate of BOD5 reached 45%+-75%. The two stage treatment system with biological nitrogen and phosphorus removal function is usually called the two stage treatment. In order to deal with a specific substance, the treatment system set up after the two stage treatment belongs to the three stage treatment, such as chemical phosphorus removal, activated carbon adsorption and so on.