Implementation of sewage transfer network
The purpose of collecting sewage and Implementation of sewage transfer network It is the correct transfer of all sewage to the sewage treatment plant so that while the effluents reach the sewage treatment plant in the shortest possible time and the flow rate is not such that it causes a disturbance when it overflows to the sewage pumping station.
Human sewage or urban sewage is produced in urban or rural residential complexes as a result of activities such as cooking, bathing, washing clothes, dishes, kitchen and other human activities and due to its high organic load and pollution as well as the existence Pathogenic microbes It is dangerous and it is necessary that this wastewater be transferred to the treatment plant through the sewage collection network and return to the environmental cycle after the treatment process.
One of the most important issues in the field of urban management is the collection and transfer of sewage outside the boundaries of cities and villages.
Preservation of the environment, improvement of the health of urban communities and various other factors are among the necessities that have led to the construction of urban sewage networks and facilities.
What is a sewage collection network?
The sewage network is a system consisting of sewage pipes for transporting domestic and non-domestic sewage to the sewage treatment plant or its storage place, septic tank, etc. .
Effective factors in the type of sewage network:
1- The size of the city
2- Living standard of residents
3- Type of water supply system
4- Topography of the region
5- The type of surfaces of streets and sidewalks
6- Intensity and return period of precipitation
7- Economic situation of the city.
Types of conventional sewage collection network
Sewage and surface water runoff are collected separately through the sewage transfer network.
Separate sewage networks:
In this case, two sewage networks are used, one for sanitary sewage collection and the other for collection.
In other words, sanitary and commercial sewage as well as industries and workshops located within the city are collected separately and directed to the treatment plant. Also, if there is a need to collect surface runoff, a separate network will be designed and implemented.
–Separation of duties and responsibilities between municipalities and water and sewage companies as responsible for collecting, transferring and directing rainwater and urban runoff; Municipalities and the duty of collecting and disposing of sanitary waste is the responsibility of water and sewage companies.
– Limited and small amount of annual rainfall; The shortness of the rainy season and the few rainy days per year in most regions of the country
– Existence of rainwater collection and transfer system in the form of open streams and their simultaneous implementation with the construction of roads.
– Requirement to separate the sewage network and rainwater disposal system inside the houses with the implementation of Chapter 16 of the general regulations of the building.
Combined sewer network:
When sanitary wastewater and surface runoff are collected by a sewer network, it is called a composite network. When the flow in a composite wastewater is without surface runoff, it is called precipitation-free flow (DWF). To The implementation of the sewage transfer network in this type of network is designed and implemented only by a series of sewers, so the design flow rate and as a result the diameter of the sewers is more than a separate network.
Semi-composite sewage network:
To run the sewage transfer network Semi-separated, only one set of pipes is installed. So that, in addition to sanitary sewage, the primary runoff from washing the target area also enters the sewer. When the runoff flow exceeds a certain limit, the excess amount over the capacity of the network is discharged by the receiving open channels.
