Primary treatment belongs to physical treatment, which mainly removes suspended solid pollutants from sewage. Most physical processing methods can only meet the requirements of primary processing. After primary treatment, BOD can generally be removed by about 30%, which can not meet the discharge standard. Primary treatment belongs to the pretreatment of secondary treatment.
The secondary treatment mainly removes colloid and dissolved organic pollutants (BOD, COD) in sewage, and the removal rate can reach over 90%, so that the organic pollutants can meet the discharge standards.
Tertiary treatment, further treatment of refractory organic matter, soluble inorganic matter such as nitrogen and phosphorus that can lead to eutrophication of water body. The main methods include biological nitrogen and phosphorus removal, coagulation and sedimentation, sand filtration, activated carbon adsorption, ion exchange and electrodialysis.
The whole process is that the raw sewage passing through the coarse grid is lifted by the sewage lifting pump, then flows through the grid or sand filter, and then enters the grit chamber, and the sewage separated from sand and water enters the primary grit chamber, which is the primary treatment. The effluent from the primary sedimentation tank enters biological treatment equipment, including activated sludge process and biofilm process (the reactors of activated sludge process include aeration tank and oxidation ditch, etc.). Biofilm method includes biological filter, biological turntable, biological contact oxidation method and biological fluidized bed. The effluent from biological treatment equipment enters the secondary sedimentation tank, and the effluent from the secondary sedimentation tank is discharged after disinfection or enters the tertiary treatment. The primary treatment ends here as secondary treatment, and the tertiary treatment includes biological nitrogen and phosphorus removal, coagulation and sedimentation, sand filtration, activated carbon adsorption, ion exchange and electrodialysis. Part of the sludge in the secondary sedimentation tank flows back to the primary sedimentation tank or biological treatment equipment, and part of it enters the sludge concentration tank and then enters the sludge digestion tank. After dehydration and drying equipment, the sludge is finally utilized.
Baoding Yin Hong Yu Rui Water Equipment Manufacturing Co., Ltd. is an engineering enterprise focusing on agricultural water-saving irrigation, improving urban and rural water supply, developing urban and rural water environment and air treatment. The company has strong financial strength, and now has a number of operating qualifications such as municipal level III, water conservancy and hydropower level III, environmental protection level III, construction level III, highway level III and electromechanical installation level III. And can basically undertake all kinds of large and medium-sized water conservancy projects. At the same time, the company has established and improved an efficient operation system, relying on the Internet platform and adopting remote control technology to realize real-time monitoring of engineering projects.