Domestic sewage refers to the wastewater generated by residents in their daily lives, including toilet drainage, washing drainage, kitchen drainage, and other miscellaneous domestic drainage. Domestic sewage contains a large amount of organic matter, inorganic matter, microorganisms, and impurities, such as proteins, oils, carbohydrates, ammonia nitrogen, phosphorus, and various bacteria. If these pollutants and impurities are not properly treated, they can cause serious harm to the environment and ecosystem. Therefore, domestic sewage needs to be treated to meet discharge standards or recycling standards, in order to protect the environment and human health.

　　The principle and function of domestic sewage treatment equipment are as follows:

　　1. Septic tank: Septic tank is a treatment facility that uses sedimentation and anaerobic fermentation principles to remove suspended organic matter from domestic sewage. The principle is to decompose the solid matter at the bottom of the pool, and the hydrated substances in the upper layer enter the pipeline and flow away, preventing pipeline blockage, while giving sufficient time for the solid matter (feces and other garbage) to hydrolyze.

　　2. Air flotation machine: An air flotation machine is a water treatment equipment that uses small or tiny bubbles to make impurities in the medium float to the surface. By using a dissolved gas system, a large number of fine bubbles are generated in water, causing air to adhere to suspended particles in the form of highly dispersed small bubbles, resulting in a state of lower density than water. The principle of buoyancy is used to make it float on the water surface, achieving solid-liquid separation.

　　3. Aeration machine: By rotating the impeller, air is introduced into the sewage to increase dissolved oxygen and promote microbial activity. It is mainly used to improve water quality and promote microbial growth and reproduction.

　　4. Drum filter: The drum filter relies on the gravity of the liquid itself to pass through the filter cloth, isolate impurities, and achieve the purpose of purifying the liquid.

　　5. Centrifuge: It uses the strong centrifugal force generated by the high-speed rotation of the centrifuge rotor to accelerate the settling speed of particles in the liquid, mainly used for solid-liquid separation.

　　6. Grille cleaning machine: used to remove large particles and impurities from sewage, protecting subsequent treatment equipment from damage.

　　7. Oil water separator: removes oil and water from wastewater through physical and chemical methods to achieve oil-water separation.

　　8. Filter press: Dehydrate sludge by pressurization to form a sludge cake, which is convenient for transportation and processing.

　　9. Submersible mixer: used for mixing and circulating sewage, promoting microbial growth and organic matter decomposition.

　　10. Spiral conveyor: used for conveying solid materials such as sludge and residual activated sludge.

　　11. Sludge pump: used to transport sludge and suspended solids for subsequent treatment and disposal.

　　These devices work together to complete the task of treating domestic sewage through different principles and functions. The treated sewage can meet the discharge standards. These devices can be used individually or combined into a complete sewage treatment system. Customers can choose and configure according to different treatment requirements and sewage characteristics.