Physical treatment: the wastewater treatment method of separating and recovering the insoluble suspended pollutants (including oil film and oil beads) can be divided into gravity separation method, centrifugal separation method and screening interception method, etc.

Chemical treatment: through chemical reaction and mass transfer to separate and remove the dissolved, colloidal state of pollutants in wastewater or into harmless substances wastewater treatment method.

Biological treatment: through the metabolism of microorganisms, the solution, colloidal and fine suspended of organic pollutants in waste water will be turned into stable, harmless substance. According to the different microorganism, biological treatment can be divided into aerobic biological treatment.

Two types of anaerobic biological treatment: Aerobic biological treatment method is widely used in sewage treatment equipment. According to tradition, aerobic biological treatment method is divided into activated sludge method and biofilm method. Activated sludge process is a treatment unit, anaerobic biological treatment method, also known as biological reduction treatment method, mainly used for the treatment of high concentration of organic wastewater and sludge. The processing equipment used is mainly a digester.

Biological contact oxidation：The biological contact oxidation process is used to fill the fillers in the biological reaction tank, and the oxygenated sewage is immersed in all the fillers.