Sewage treatment refers to the process of purifying sewage to meet the water quality requirements for drainage into a certain water body or reuse.
According to the classification of sewage sources, sewage treatment is generally divided into production sewage treatment and domestic sewage treatment. Production sewage includes industrial sewage, agricultural sewage and medical sewage, etc., while domestic sewage is the sewage produced in daily life, which refers to a complex mixture of various forms of inorganic and organic matter, including: ① floating and suspended solid particles of different sizes; ② glue Like and gel-like diffusers; ③Pure solution.
According to the nature of water pollution, there are two types of water pollution: one is natural pollution; the other is man-made pollution. At present, man-made pollution is more harmful to water bodies. Water pollution can be mainly divided into three categories: chemical pollution, physical pollution and biological pollution according to different polluting impurities. The main pollutants include: ⑴ Industrial wastewater discharged without treatment; ⑵ Domestic sewage discharged without treatment; ⑶ Farmland sewage with extensive use of chemical fertilizers, pesticides, and herbicides; ⑷ ??Industrial waste and domestic garbage piled up by the river. ; ⑸ Soil erosion; ⑹ Mine sewage.