Against the backdrop of the continuous improvement of China's water pollution control system, the challenge of decentralized sewage treatment has gradually become a focus in the field of environmental protection. Although the sewage discharge from scenarios such as urban residential areas, rural settlements, small and medium-sized enterprises, and medical institutions is not as large as that from large-scale industrial clusters, their characteristics of scattered distribution and complex water quality place higher demands on the flexibility and efficiency of treatment equipment. As a targeted solution, integrated sewage treatment equipment, with its advantages of integrated design and modular operation, has become a core equipment for solving the dilemma of decentralized sewage treatment.​

I. Core Definition and Technical Characteristics of Integrated Sewage Treatment Equipment​

Integrated sewage treatment equipment is a complete set of equipment that integrates traditional sewage treatment processes (such as grilles, equalization tanks, biochemical reaction tanks, sedimentation tanks, disinfection tanks, etc.) through modularization to realize the integrated operation of the entire process of sewage collection, treatment, purification, and discharge. Its core technical characteristics are reflected in three aspects:​

• Integrated Design: It breaks through the traditional sewage treatment plant model of "multiple tanks separated and step-by-step treatment", compressing pre-treatment, biochemical reaction, advanced purification and other links into a closed box or tank. The floor area is only 1/3 to 1/5 of that of traditional processes, making it particularly suitable for scenarios with tight land use such as rural areas, scenic spots, and residential communities.​

• Intelligent Operation: Equipped with a PLC control system, it can real-time monitor key parameters such as incoming water quality, flow rate, and dissolved oxygen, and automatically adjust operating indicators such as aeration intensity and sludge return ratio. This reduces manual intervention and lowers operation and maintenance costs. Some high-end equipment also supports remote data transmission to achieve unattended operation.​

• Strong Adaptability: For different water qualities such as domestic sewage, medical wastewater, and food processing wastewater, customized treatment can be achieved by adjusting internal processes (such as A/O, SBR, MBR, etc.). The effluent quality can stably meet the first-class A standard or higher of the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants (GB18918-2002).​

II. Analysis of Core Advantages of Integrated Sewage Treatment Equipment​

Compared with the traditional sewage treatment model, integrated equipment shows significant advantages in practical applications and has become the preferred solution for decentralized sewage treatment:​

• Convenient Installation and Quick Results: The equipment is prefabricated in the factory. On-site, only foundation pouring, pipeline connection, and circuit commissioning are required. Installation and operation can be completed within 3 to 7 days, greatly shortening the project cycle.​

• Low Operation and Maintenance Costs: The modular design reduces equipment maintenance points, and intelligent control realizes energy consumption optimization (for example, the aeration system automatically starts and stops according to dissolved oxygen). The costs such as operating electricity fees and chemical fees are 20% to 30% lower than those of traditional processes.​

• Low Sludge Production: Adopting biofilm method or high-efficiency sedimentation technology, the sludge production is only 1/2 of that of the traditional activated sludge method, which reduces the pressure of sludge disposal and avoids secondary pollution.​

• Good Environmental Compatibility: The main body of the equipment can be buried underground or placed on the ground. The underground design does not occupy surface space and can be used for greening or other purposes; the above-ground equipment adopts noise reduction and deodorization treatment, which has little impact on the surrounding environment.​

III. Typical Application Scenarios of Integrated Sewage Treatment Equipment​

With its flexible and efficient characteristics, integrated sewage treatment equipment has been widely used in many fields to meet the sewage treatment needs of different scenarios:​

• Rural Domestic Sewage Treatment: In response to the characteristics of rural sewage such as "small water volume, scattered distribution, and difficult collection", the equipment can be built for a single village or multiple villages jointly. The treated water can be used for farmland irrigation or landscape reuse, contributing to rural revitalization and ecological protection.​

• Small and Medium-sized Urban Communities: In the reconstruction of new urban areas and old residential areas, integrated equipment can be used as a supplement to the municipal pipe network to solve the problem of insufficient pipe network coverage and improve the collection and treatment rate of domestic sewage.​

• Medical and Elderly Care Institutions: In view of the special components such as pathogens and disinfectants in medical wastewater, the equipment ensures safe effluent through enhanced disinfection (such as combined disinfection of ultraviolet rays and chlorine dioxide) and biochemical treatment, complying with the Discharge Standard of Water Pollutants for Medical Institutions (GB18466-2005).​

• Tourist Scenic Spots and Resorts: In areas with strict environmental requirements such as nature reserves and scenic areas, the equipment can realize "on-site treatment and up-to-standard discharge" of sewage, avoiding pollution to the ecological landscape and water sources.​

• Small and Medium-sized Industrial Enterprises: For low-concentration wastewater in industries such as food processing, slaughtering, and printing and dyeing, the equipment can achieve pre-treatment or up-to-standard discharge through customized processes (such as adding air flotation devices and decolorization units) to meet the requirements of environmental supervision.​

IV. Key Points for Selection, Operation and Maintenance of Integrated Sewage Treatment Equipment​

To ensure the long-term stable operation of the equipment, users should pay attention to the following matters during the selection, operation and maintenance process:​

• Accurately Matching Treatment Needs: Select the equipment model according to the sewage discharge volume (daily average water volume), water quality components (such as COD, ammonia nitrogen, total phosphorus concentration), and discharge standards (such as first-class A, surface water class IV standard) to avoid "overcapacity" or insufficient treatment capacity.​

• Focusing on Core Materials and Processes: It is recommended that the main equipment be made of glass fiber reinforced plastic, carbon steel with anti-corrosion treatment, or 304 stainless steel, which is resistant to acid and alkali corrosion and can extend the service life. For core processes, mature and stable technologies such as A/O and MBR should be preferred to reduce the risk of later transformation.​

• Attaching Importance to Operation and Maintenance Service Capabilities: Choose manufacturers with a complete after-sales system to ensure timely response when equipment failures occur; at the same time, regularly clean the equipment, replace filter materials, and overhaul pumps and valves to avoid system shutdown due to minor failures.​

• Considering Long-term Economy: In addition to the equipment purchase cost, it is necessary to comprehensively evaluate long-term costs such as operating energy consumption, chemical consumption, and sludge disposal. Priority should be given to energy-saving equipment (such as using frequency conversion water pumps and solar aeration systems).​

V. Industry Trend: Integrated Equipment Promoting the Intelligent Upgrade of Sewage Treatment​

With the in-depth advancement of the "dual carbon" goal and the rural revitalization strategy, integrated sewage treatment equipment is developing towards miniaturization, low-carbonization, and intelligence. In the future, the smart operation and maintenance platform combined with the Internet of Things technology will realize the linkage management of multiple equipment and optimize operating parameters through big data analysis; at the same time, the integration of low-carbon technologies such as photovoltaic drive and sewage heat recovery will further reduce the environmental impact of the equipment.​

As a "powerful tool" for decentralized sewage treatment, integrated sewage treatment equipment not only solves the pain points of traditional processes, but also promotes the transformation of sewage treatment from a "centralized-based" model to a "centralized + decentralized" collaborative model through technological innovation, providing key support for the continuous improvement of China's water environment quality.