1. Wastewater treatment system

According to the treatment degree, wastewater treatment technology can be divided into primary, secondary and tertiary treatment. Generally, wastewater that is treated to some extent is treated by the previous treatment steps.

II. Physical, chemical and physicochemical treatment of wastewater

The physical, chemical and physicochemical treatment of wastewater includes grid, regulating tank (equalizing tank, homogenizing tank, homogenizing tank and accident tank), grit chamber, sedimentation tank, oil separation, neutralization treatment, chemical precipitation treatment, air flotation, coagulation, filtration and membrane.

iii. biological treatment of wastewater

biological treatment is suitable for wastewater that can be degraded by microorganisms, and can be divided into aerobic method and anaerobic method according to the living environment of microorganisms. Aerobic biological treatment is suitable for wastewater with influent BOD5/COD≥1.3. Anaerobic biological treatment is suitable for the treatment of high concentration and refractory organic wastewater and sludge.

IV. Ecological treatment

Ecological treatment includes land treatment and constructed wetland.