Expanded reading: sewage treatment plant refers to the sewage (wastewater) discharged from the source of pollution, because the total amount of pollutants contained in the pollutant or the concentration of high, not up to the requirements of the discharge standards or do not adapt to the environmental capacity requirements, thereby reducing the quality of the water environment and the functional objectives of the site, it is necessary to artificially strengthen the treatment of the place, the place is the sewage treatment plant, also known as the sewage treatment station.