At present, urban sewage treatment methods mainly include physical chemical adsorption, chemical and biological methods.
Among them, the physicochemical adsorption method is widely used because of its small investment and simple process operation. The main pollutants include aerobic organic matter, suspended matter pathogens, nitrogen and phosphorus. Aerobic organic matter can reduce the oxygen content of water, cause bacteria to breed, deteriorate water quality, and cause water to become odorous.