The integrated sewage treatment equipment replaces the secondary sedimentation tank in the traditional process. It can separate solids and liquids and obtain stable recycled water for direct use. It can also maintain a high concentration of microbial biomass in the biological pool, have less process residual sludge, remove ammonia nitrogen, effluent suspended solids and turbidity close to zero, greatly remove bacteria in the effluent, have low energy consumption and occupy a small area. This processing technology can be divided into the following three types of processing according to the degree of processing:

       Primary treatment: It mainly removes suspended solid pollutants in sewage. Most physical treatment methods can only meet the requirements of primary treatment. After primary treatment, the BOD removal rate is generally around 30%, which does not meet the emission standards. The primary treatment of integrated sewage treatment equipment is a pretreatment of secondary treatment.

       Secondary treatment: mainly removes colloids and dissolved pollutants in sewage, with a removal rate of more than 90%, so that organic pollutants can meet discharge standards.

       Third-level treatment: further treatment of refractory organic matter, nitrogen, phosphorus and other soluble inorganic matter that can cause eutrophication of water bodies. The main methods include biological nitrogen and phosphorus removal, coagulation sedimentation, sand ratio, carbon adsorption, ion exchange and electroosmotic analysis.

       Based on different water quality, sewage treatment is divided into many levels, so the selected integrated sewage treatment equipment is also different. When selecting equipment, the total amount of sewage treatment should also be considered. Different problems have different treatment methods. For example, some water quality requires oil separation treatment, while other water quality, such as sewage with relatively high organic matter content, should choose anaerobic and aerobic treatment.