main sources of sewage in cities
1.1 living sewage
Domestic sewage mainly comes from all kinds of kitchen water, washing water and toilet water used in human life. Because of its large displacement and bacteria, it is difficult to deal with, so it is a serious threat to human health. In addition, with the acceleration of urbanization and the rapid growth of population, the problem of domestic sewage treatment is becoming more and more serious, which leads to serious excess of sewage discharge.
1.2 industrial waste water
Industrial wastewater including production wastewater and sewage production, is mainly produced in the industrial production process of wastewater and waste, and waste water, waste and pollutants produced in industrial production materials and production process, its chemical composition is high, long-term accumulation of easily lead to the occurrence of some difficult diseases, extremely harmful to human health.
Mixed water of precipitation in 1.3 cities
Precipitation is the natural recharge of water resources is the most important, but the modern city of surface hardening mixed with impurities resulting in more precipitation, causing damage to the water from the source, and the mixed water city precipitation include sewage discharge, so the water quality will be severely damaged.