JPH04265329A - Rain-water disposal method of sewerags system, and construction method of rain-water disposal equipment and rain-water retardation pipe line - Google Patents

Abstract

PURPOSE:To automatically separate initial rainwater having increased pollution from rainwater having reduced pollution without using any special means to store them, to reduce the total amount of pollutants to a river, the sea, etc., and to dissolve environmental pollution. CONSTITUTION:A low level weir 3 having a height corresponding to the water level caused by initial rain and a weir 4 higher than the weir 3 are provided to part of a sewerage pipe line, and sewage by the initial rain is over flowed from the low level weir 3 to keep it into the first rainwater retardation equipment 5. The first rainwater storage equipment is filled with water, and after it is overflowed from the high level weir 4, the sewage is kept into the second rainwater storage equipment 6. After that, the water in the storage equipments is separately disposed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rainwater treatment method in a combined or separate sewer system, a rainwater treatment facility, and a method for constructing a rainwater drainage pipe in the facility.

0002

2. Description of the Related Art In conventional combined sewer systems, domestic wastewater (sewage) is normally collected from a portion of the sewage pipe to a sewage treatment plant via an interceptor pipe and subjected to high-grade treatment. During rainfall, rainwater flows into the sewage pipes through water collection boxes on the ground, and rainwater that is within the capacity of the sewage pipes is mixed with domestic sewage and collected at the treatment plant, but rainwater that exceeds the processing capacity of the treatment plant is discharged untreated from treatment plants into rivers or the sea. In addition, when the amount of rainfall exceeds the capacity of rainwater, which is more than the amount of sewage treated as sewage, it is discharged untreated into rivers or the sea from the rainwater discharge chamber and pumping station installed in a part of the sewage pipe. .

[0003] Furthermore, in conventional separate sewer systems, domestic sewage is collected in a dedicated sewage pipe, treated at a sewage treatment plant, and then discharged, and rainwater is collected in a rainwater pipe and discharged into a river or the sea. . When rainfall exceeds the capacity of the rainwater pipes, the rainwater cannot flow down, leading to flooding of houses.

Most conventional rainwater storage facilities are designed to prevent disasters such as flooding by directing rainwater that exceeds the capacity of sewers and rivers to rainwater regulating ponds to reduce peak flow rates and reduce pollution loads. No measures have been taken to deal with early rainwater during rainy days when the volume is high.

[0005] Some sewage treatment facilities have taken measures against initial rainwater in the past, but a rainwater drainage pond was installed near the treatment plant to store the initial rainwater during rainy days and store it in the rainwater drainage pond. Sewage was transported to a treatment plant for treatment after the rains ended.

[0006]

[Problems to be Solved by the Invention] In conventional combined sewerage facilities, highly polluted initial rainwater, less polluted rainwater, and domestic sewage are mixed, and the sewage exceeds the capacity of the pipes and treatment equipment. It is discharged untreated into rivers and the sea, causing environmental pollution. In addition, when rainfall exceeds the capacity of the pipelines, disasters such as flooding occur.

[0007] In conventional separate sewerage facilities, domestic sewage and rainwater are separated, but the highly polluted initial rainwater is discharged untreated into rivers and the sea, which still poses the problem of environmental pollution. . In addition, rainwater that exceeds the capacity of the pipes will accumulate on the ground, making disasters such as flooding unavoidable.

In conventional rainwater storage facilities, rainwater that exceeds the capacity of rivers or pipes is temporarily stored in the rainwater storage facility, but the stored rainwater is a mixture of highly polluted initial rainwater and less polluted rainwater. However, the total amount of pollution load discharged into rivers, oceans, etc. has not been reduced.

[0009] Conventional sewage treatment facilities that take measures against early rainwater require large-scale storage facilities for storing initial rainwater. In this case as well, rainwater exceeding the capacity of the pipes accumulates on the ground, causing disasters such as flooding.

FIG. 9 shows the relationship between the elapsed time during rain and the average flow rate in a combined sewer system, and FIGS. 10, 11, and 12 show the relationship between the elapsed time during rain and the concentrations of COD, BOD, and SS. Each is shown below. As you can see from these figures,
It has been confirmed that the pollution caused by initial rainwater is particularly large, and that by purifying the initial rainwater, the total amount of pollution load can be significantly reduced.

[0011] The purpose of the present invention is to automatically separate and store highly polluted initial rainwater and less polluted rainwater without using any special method, thereby reducing the amount of water flowing into rivers, oceans, etc. The purpose is to reduce the total amount of pollution load, eliminate the problem of environmental pollution, and prevent disasters such as flooding.

Another object of the present invention is to efficiently construct drainage pipes for storing highly polluted initial rainwater and flood control pipes for storing rainwater that has become less polluted. The purpose is to provide a method that can be used to construct

[0013]

[Means for Solving the Problems] The rainwater treatment method of the present invention, for a combined sewer, includes a low weir with a height commensurate with the water level due to initial rainfall in a part of the sewer pipe, and a A higher weir was installed, and the sewage from the initial rainfall was allowed to overflow from the lower weir and stored in the first drainage facility, and when the first drainage facility became full, it overflowed the higher weir. The second sewage
The wastewater from both drainage facilities will be treated separately.

[0014] In addition, for a separate sewer system, a part of the rainwater pipe is provided with a communication part to the first drainage facility and a weir higher than the communication part, so that the initial rainwater is transferred to the first drainage facility. After the first drainage facility is full and has passed over the weir, the rainwater is stored in the second drainage facility.
Rainwater from both drainage facilities will be stored and treated separately.

[0015] In the case of a combined sewer system, the rainwater treatment facility according to the present invention includes a low weir with a height commensurate with the water level due to initial rainfall and a higher weir higher than that in a part of the sewer pipe. and a sloping first drainage pipe through which overflow water from a lower weir flows in from the upper end and is filtrated, and a second drainage pipe through which overflow water from a higher weir is discharged. . A pit is provided in a part of the first drainage facility, and the first drainage facility can be washed with water stored in the pit.

[0016] The method of constructing a rainwater drainage pipe according to the present invention is a double-section shield excavation method in which a first drainage pipe and a second drainage pipe are connected in parallel in a manner that allows separation of two single-section shield excavators. Construction is done by machine.

[0017]

[Operation] According to the rainwater treatment method and rainwater treatment facility according to the present invention, initial rainwater is stored in the first drainage pipe, and the initial rainwater is stored in the first drainage pipe.
When one drainage facility becomes full, the water level in the sewage pipe or rainwater pipe rises and overflows the weir, and subsequent rainwater is stored in the second drainage facility. Therefore, the highly polluted initial rainwater and the less polluted rainwater can be treated separately. By storing rainwater in a pit provided in a part of the first drainage facility and discharging the stored water as needed, the first drainage facility can be easily cleaned.

According to the method of constructing a rainwater drainage pipe according to the present invention, the first drainage pipe for initial rainwater and the second rainwater drainage pipe for flood control are constructed simultaneously and arbitrarily using a multi-section shield excavator. It can be constructed with the tunnel alignment.

[0019]

Embodiments Next, embodiments of the present invention will be described in detail with reference to the drawings. The concept of the rainwater treatment method of the present invention is shown in FIGS. 1 and 2, with FIG. 1 showing the case of a combined sewer system and FIG. 2 showing the case of a separate sewer system. In FIG. 1, an underground water diversion room 2 is provided in the middle of an underground sewage pipe 1 through which domestic sewage and rainwater flow, and the underground water diversion room 2 is provided to penetrate the sewage pipe 1. A lower weir 3 and a higher weir 4 are provided in a part. The height of the lower weir 2 shall be commensurate with the water level caused by the initial rainfall. Therefore, it is slightly higher than the highest water level of domestic sewage. In order to store the initial rainwater that overflows from the lower weir 3, the first
A rainwater drainage pipe 5 is provided so as to be inclined downward from the upper end toward the lower end (blind end). The capacity of the rainwater drainage pipe 5 is set to be large enough to at least intercept initial rainwater at a statistically determined standard rainfall amount.

The height of the higher weir 4 is such that the rainwater flowing through the sewer pipe 1 can overflow after the first rainwater drainage pipe 5 is filled with water, as shown in FIG. In order to store the overflow water, a second rainwater drainage pipe 6 for flood prevention, which is larger than the first rainwater drainage pipe 5, is provided.

The initial rainwater stored in the first rainwater drainage pipe 5 is sent to the original sewage pipe 4 or to another sewage pipe 8 by the pump 7, and then undergoes advanced treatment at a sewage treatment facility. The rainwater stored in the rainwater drainage pipe 6 is sent by a pump 9 and discharged into a river 10 on the ground or the ocean.

[0022] A gate 1 is installed at the upper part of the first rainwater drainage pipe 5.
1 is provided to partition a wash water pit 12, and a part of the initial rainwater is stored in the pit 12 by closing the gate 11 before draining with the pump 7. After draining water by the pump 7, the gate 11 is opened and the inside of the first rainwater drainage pipe 5 is washed using the initial rainwater in the pit 12 as washing water.

In the case of the separate sewer system shown in FIG. 2, the rainwater pipe and the sewage pipe are separated, so a part of the rainwater pipe 1a has a communication section 3a that communicates with the first rainwater drainage pipe 5.
A higher weir 4 is provided in the communication portion 3a, and the rainwater after the first rainwater drainage pipe 5 is filled with water is allowed to overflow from the weir 4 to the second one.
The water is stored in the drainage pipe 6.

FIGS. 3 to 6 show a rainwater treatment facility according to an example of the present invention. The first rainwater drainage pipe 5 runs parallel to the sewage pipe 1 up to the point corresponding to the underground water diversion room 2.
The part beyond is inclined and gradually moves away from the sewage pipe 1 downward, and the drainage pit 14 at the lower end of the water pumping shaft 13
It has reached this point. Overflow water from a lower weir 3 in the middle of the sewer pipe 1 flows into the first rainwater drainage pipe 5 from the communication passage 15. A gate 11 is provided near the inlet, and a wash water pit 12 is defined at the upper end of the first rainwater drainage pipe 5 by the gate 11 .

On the other hand, the second rainwater drainage pipe 6 is connected to the sewer pipe 1 from the inflow shaft 16 provided near the underground water diversion chamber 2.
It extends below and parallel to this to reach a drainage pit 17 near the lower end of the drainage pit 13. Overflow water from the upper weir 4 in the middle of the sewage pipe 1 flows through the communication passage 18 into the inflow shaft 1.
6 and flows from the lower end of the pit 16 through the communication path 19 into the second rainwater drainage pipe 6.

Drainage pit 1 at the lower end of drainage pit 13
Drainage pumps 7 and 9 are installed at 4 and 17, respectively. The initial rainwater stored in the first rainwater drainage pipe 5 is pumped up through the pumping pipe 20 by the drainage pump 7 and returned to the sewage pipe 1. The less polluted rainwater stored in the second rainwater drainage pipe 6 is pumped through the pumping pipe 21 by the drainage pump 9 and discharged into the river 10 on the ground or the ocean.

After the initial rainwater stored between the gate 11 and the drainage pit 14 is returned to the sewage pipe 1 as described above, the initial rainwater stored in the washing water pit 12 is drained by opening the gate 11. The rainwater is discharged to the rainwater drainage pipe 5 of No. 1, and the inside thereof is washed.

Next, a construction method for the first rainwater drainage pipe 5 and the second rainwater drainage pipe 6 will be explained. FIG. 7 shows a multi-section shield excavator 22 that performs the construction, and there are two large and small single-section shield excavators, that is, a large-diameter single-section shield excavator 23 that constructs the second rainwater drainage pipe 6, and a second 1
A small-diameter single-section shield excavator 24 for constructing a rainwater drainage pipe 5 is separably connected in parallel via a connecting piece 25 (FIG. 8). Each of the single-section shield tunneling machines 23 and 24 has a front body part 27 swingable relative to a rear body part 26. Each single-section shield tunneling machine 23, 24 is equipped with a cutter on the front side of its front body 27, and
It is equipped with a known propulsion mechanism such as a cutter drive mechanism and a propulsion jack, a muddy water pressurization mechanism, a muddy soil pressurization mechanism, a mud removal mechanism, etc., and has a structure that allows single-section shield tunnels to be constructed independently.

The large and small single-section shield tunneling machines 23 and 24 are connected, and they are simultaneously launched from the lower end of the drainage pit 13 with the large single-section shield tunneling machine 23 at the top and the small single-section shield tunneling machine 24 at the bottom. Each single section shield excavator 23
, 24, the shields are installed separately. After digging a certain distance, the front body 2 of the small single section shield excavator 24
7 upward, the large single-section shield excavator 23 attempts to dig straight, and the small single-section shield excavator 24 attempts to dig diagonally upward, so both single-section shield excavators 23, 24
A rotational moment is generated in the small single section shield excavator 24.
Large single section shield excavator 23 so that it is twisted spirally
progress from the bottom to the top.

After this, both single-section shield excavators 23, 2
4 is separated as shown in Figure 8, and the large single section shield excavator 23
Go straight ahead, and the small single-section shield excavator 24 excavates obliquely upward, and if the shield is constructed at each target point, the second rainwater pipe 6 and the first rainwater drainage pipe 5 will be completed in parallel. be done.

[0031] Initial rainwater and flood control in rivers can also be treated in the same way by providing the above-mentioned overflow equipment, first and second rainwater permeation facilities, and drainage equipment.

[0032]

[Effects of the Invention] According to the rainwater treatment method and rainwater treatment facility of the present invention, highly polluted initial rainwater and less polluted rainwater can be separated by simply installing a weir in the middle of a sewage pipe or a rainwater pipe. , can be automatically separated and stored and drained separately. Therefore, the total amount of pollution load on rivers, oceans, etc. due to initial rainwater can be reduced, the problem of environmental pollution can be solved economically, and disasters such as flooding can be prevented.

[0033] Furthermore, according to the method of constructing rainwater drainage pipes according to the present invention, the drainage pipes for storing initially highly polluted rainwater and the drainage pipes for storing rainwater that has become less polluted can be efficiently constructed. It can be constructed easily.

[Brief explanation of the drawing]

[Figure 1] Conceptual diagram of the rainwater treatment method of the present invention for combined sewer system

[Figure 2] Conceptual diagram of the rainwater treatment method of the present invention for separate sewerage system

[Figure 3] Longitudinal cross-sectional view of an example of a rainwater treatment facility according to the present invention

[Figure 4] Transverse plan view of the same as above

[Figure 5] Cross-sectional view at line A-A in Figure 3

[Figure 6]
Cross-sectional view taken along line B-B in Figure 3

[Figure 7]
A perspective view of an example of a multi-section shield excavator for constructing rainwater drainage pipes

[Figure 8] Perspective view of an example of construction using the same shield excavator

[Figure 9] Graph showing the relationship between the elapsed time during rainfall and the average flow rate in a combined sewer system

[Figure 10] Graph showing the relationship between elapsed time during rainfall and COD concentration

[Figure 11] Graph showing the relationship between elapsed time during rainfall and BOD concentration

[Figure 12] Graph showing the relationship between elapsed time during rainfall and SS concentration

[Explanation of symbols]

1 Sewer pipe 3. Lower weir 4. High weir 5 First rainwater drainage pipe 6 Second rainwater drainage pipe 1a Stormwater pipe 3a　　　　Communication part 11 Gate 12 Washing water pit 22 Multi-section shield tunneling machine 23 Single section shield tunneling machine 24 Single section shield tunneling machine

Claims (7)

[Claims] Claim 1: In a combined sewer system, a part of the sewage pipe is provided with a low weir whose height is commensurate with the water level caused by the initial rainfall, and a higher weir which is higher than the weir, so that the sewage from the initial rainfall is drained from the lower weir. The water overflows from the weir and is stored in the first drainage facility.
A rainwater treatment system for sewerage systems characterized by storing sewage in a second drainage facility after one drainage facility becomes full and exceeding a high level weir, and treating the sewage from both of these facilities separately. Method. Claim 2: In a separate sewer system, a part of the rainwater pipe is provided with a communication part to a first drainage facility and a weir higher than the communication part, and initial rainwater is stored in the first drainage facility. , a sewerage system characterized in that the rainwater after the first drainage facility becomes full and exceeds the weir is stored in a second drainage facility, and the rainwater from both of these facilities is treated separately. rainwater treatment methods. 3. The sewer system according to claim 1 or 2, wherein a pit is provided in a part of the first drainage facility, and the first drainage facility is washed with water stored in the pit. rainwater treatment methods. Claim 4: In a combined sewer system, a part of the sewage pipe is provided with a low weir whose height is commensurate with the water level due to initial rainfall, and a higher weir which is higher than the water level, and in which water from the low weir is provided. A sewerage system characterized by comprising a first sloped drainage pipe through which overflow water flows in from the upper end and is flushed, and a second drainage pipe through which overflow water from a high weir is discharged. Rainwater treatment facility. 5. In a separate sewer system, a part of the rainwater pipe is provided with a communication part to the first drainage facility and a weir higher than the communication part, and the rainwater from the communication part is allowed to flow in from the upper end. A rainwater treatment facility for a sewage system, comprising: a first sloped drainage pipe that drains overflow water from the weir; and a second drainage pipe that drains overflow water from the weir. 6. An openable and closable gate is provided in the upper part of the first permeable water pipe to define a washing water pit, and a part of the water in the first permeable water pipe can be stored in the pit. The rainwater treatment facility for sewerage according to claim 4 or 5, characterized in that: 7. The first drainage pipe and the first drainage pipe are constructed by a multi-section shield excavator in which two single-section shield excavators are separably connected in parallel. Construction method for rainwater drainage pipes.