Discharge of sewage (waste) water from pollution sources, because of the total amount or concentration of pollutants containing high, can not meet the requirements of the discharge standards or does not adapt to the requirements of environmental capacity, thereby reducing the quality of the water environment and functional objectives, the need to go through the artificially enhanced treatment of the site.

Generally divided into urban centralized wastewater treatment plants and decentralized wastewater treatment plants for each pollution source, which is discharged into water bodies or urban pipelines after treatment. Sometimes, in order to recover and recycle wastewater resources, it is necessary to improve the quality of treated effluent to build wastewater reuse or recycling wastewater treatment plants.

The treatment process of the treatment plant is an optimized combination of various common or special water treatment methods, including a variety of physical, chemical, and biological methods, requiring advanced technology, economic and reasonable, and the most economical.

The design must implement the current national construction guidelines and policies.

Therefore, in terms of treatment depth, the wastewater treatment plant may be primary, secondary, tertiary, or deep treatment.

The design of wastewater treatment plant includes various different treatment structures, accessory buildings, pipeline plans, elevation design and design of roads, landscaping, pipeline synthesis, plant water supply, and drainage, sludge disposal and treatment system management automation, etc. to ensure that the wastewater treatment plant to achieve stable treatment effect, meet the design requirements, convenient operation and management, advanced technology, investment and operation cost-saving, and other various requirements.