Characteristics of urban domestic sewage
1. Water quality changes greatly:
Due to the different scale and nature of urban industries and the different proportions of domestic sewage, the quality of urban sewage varies greatly. The quality of urban sewage water not only varies greatly due to different industrial structures, but also the quality of sewage water discharged by cities and towns with the same industrial structure also varies greatly. Even in different seasons and at different times of the day, the quality of sewage discharged from the same town will change greatly.
2. Large changes in water volume:
Urban sewage is affected by the local population. In particular, economically developed towns have a large migrant labor population and are relatively mobile. Therefore, the sewage volume may change greatly with seasons and holidays within a year, even at different times on the same day. The amount of sewage water will also vary.
3. The collection system is greatly affected by rainfall:
At present, there are few internal and external diverted drainage systems in established cities and towns. Urban sewage treatment plants are directly affected by urban drainage systems and rainfall.
4. Wastewater contains a large amount of grease, food residue, etc., with high suspended solids and large color.
5. Wastewater contains a large amount of residual food, etc., which causes the wastewater to have a strong smell and easily stink.
6. The concentration of organic matter in wastewater is relatively high, as are the sources of nitrogen and phosphorus. Direct discharge can easily cause eutrophication of water bodies.
