Selection of sewage treatment process: choose the appropriate sewage treatment process according to demand. Currently the mainstream integrated wastewater treatment equipment process is: AO (contact oxidation), MBR (biofilm method), SBR (sequential batch activated sludge method), CASS (cyclic activated sludge method). Among them, AO method and MBR method are the most common, AO method can reach the standard of urban wastewater treatment plant discharge level B, and the medical industry direct discharge standard, MBR method can reach the standard of urban wastewater discharge level A, and its treatment effect is particularly good, suspended solids and turbidity is close to zero, can be directly reused as a non-drinking municipal miscellaneous water. Of course, the treatment cost of MBR method is correspondingly high. Concerned about hydraulic retention time: Simply writing HRT, hydraulic retention time refers to the average residence time of sewage in the reactor, that is, the reaction time of sewage and microorganisms. Therefore, if the effective volume of the reactor for V (cubic meters), then: HRT = V / Q (h), Q (h) = V treatment of water / 24h, integrated equipment, the greater the effective volume of sewage in the equipment inside the hydraulic retention time is longer, the microorganisms and pollutants in contact with the more adequate, and accordingly the better the treatment effect. Equipment material: material that is integrated sewage treatment equipment tank material. Currently on the market mainly in carbon steel, stainless steel, glass fiber reinforced plastic, and other materials. Integrated wastewater treatment equipment, now commonly used carbon steel as a material, it has a high cost-effective, high strength, the characteristics. Fiberglass reinforced plastic is light and hard, corrosion resistance, but long-term use is easy to deformation aging. Stainless steel is a great feature of corrosion resistance and good welding, in a corrosive environment, the service life than carbon steel, fiberglass material long service life, but the price is the highest of the three.