Initial rainwater treatment device for rainwater and sewage diversion system

Abstract

The utility model relates to an initial rainwater treatment device for a rainwater and sewage diversion system, which comprises a rainwater collection unit and a rainwater treatment unit, the rainwater collection unit comprises a rainwater drainage pipeline, a primary rainwater drainage pipeline and a middle and later rainwater drainage pipeline; the rainwater treatment unit comprises a land water boundary, a water collecting area, a water collecting area retaining wall, a main treatment area, a main treatment area retaining wall, a precipitation separation area, a water outlet dam and a main water body; the primary rainwater drainage pipeline is communicated with the water collecting area through the land-water boundary; the middle and later stage rainwater drainage pipeline is directly communicated with the main water body; the rainwater treatment system has the advantages that pollutants in initial rainwater can be effectively removed through the cyclone separator and the biological membrane treatment system according to the water quality characteristics of the initial rainwater of the rainwater and sewage diversion and collection system, so that polluted initial rainwater and pollution-free later rainwater can be treated in a differentiated manner; and treatment and diversion of polluted rainwater and pollution-free rainwater are realized.

Description

Technical Field

[0001] The utility model belongs to the technical field of rainwater treatment, and relates to a rainwater treatment device, in particular to a treatment device for the initial rainwater in a rainwater-sewage separation system. Background Art

[0002] With the rapid advancement of urbanization and the rapid development of the economy in China, the newly built urban rainwater-sewage pipe systems are gradually being improved. Currently, it is required to adopt the form of rainwater-sewage separation for treatment and discharge. Moreover, the early built rainwater-sewage combined pipe network systems are also gradually being transformed into rainwater-sewage separation pipe network systems to improve the water environment quality by continuously reducing the amount of pollutants flowing into the water environment. However, in the past process, due to the existence of certain pollutants in the atmosphere and on the ground surface, and at the same time, due to incomplete transformation of the separation system or the existence of misconnections and wrong connections in the separation system, the initial rainwater generated at the beginning of rainfall often carries most of the pollutants in the entire rainfall cycle and is discharged into the water body, thus causing pollution to the water body.

[0003] The main pollution sources of the initial rainwater are road runoff and roof rainwater in surface runoff. Its main pollutants are BOD (Biochemical Oxygen Demand), COD (Chemical Oxygen Demand), and SS (Suspended Solid). The concentrations of TN (Total Nitrogen) and TP (Total Phosphorus) in the initial rainwater are relatively low, lower than the first-class A discharge standard of the "Pollutant Discharge Standard for Urban Sewage Treatment Plants".

[0004] The main existing methods for treating initial rainwater are simple processes such as sedimentation and filtration or complex processes similar to the entire sewage treatment process in sewage treatment plants. The initial rainwater carries pollutants, but the rainfall process is intermittent, that is, the initial rainwater is an intermittent pollutant treatment object. If a simple process is used for the initial rainwater treatment process, it can be treated intermittently, but the dissolved pollutants contained in the initial rainwater cannot be effectively treated and enter the water body. Some relatively complex treatment processes are not suitable for treating initial rainwater in an intermittent manner. An initial rainwater storage tank needs to be set up, occupying land area. When there is little rain or even no initial rainwater can be collected during the dry season, the treatment system stops operating for a long time, which is likely to cause waste of resources and unstable treatment effects. Moreover, the general operation process of relatively complex treatment processes is complex, the operation and maintenance workload is large, and a large amount of sludge generated during this period also needs to be further treated and disposed, which is very wasteful of manpower and material resources. Content of the Utility Model

[0005] The purpose of the present utility model is to solve the problems existing in the prior art, and for this, a treatment device for the initial rainwater in a rainwater and sewage diversion system is provided.

[0006] To achieve the above object, the technical solution adopted by the present utility model is:

[0007] A treatment device for the initial rainwater in a rainwater and sewage diversion system, the treatment device is arranged in the water body, and includes a rainwater collection unit and a rainwater treatment unit. The rainwater collection unit includes a rainwater discharge pipe, a primary rainwater discharge pipe, and a mid-late stage rainwater discharge pipe; wherein, the primary rainwater discharge pipe and the mid-late stage rainwater discharge pipe are respectively vertically connected to the rainwater discharge pipe and form a communication with the rainwater discharge pipe.

[0008] The rainwater treatment unit includes a land-water boundary, a catchment area retaining wall, a main treatment area retaining wall, and an outlet dam; wherein, a catchment area is arranged between the land-water boundary and the catchment area retaining wall; a main treatment area is arranged between the catchment area retaining wall and the main treatment area retaining wall; a sedimentation and separation area is arranged between the main treatment area retaining wall and the outlet dam; a main water body is also arranged outside the outlet dam; wherein, the primary rainwater discharge pipe is interconnected with the catchment area through the land-water boundary; the mid-late stage rainwater discharge pipe is directly connected to the main water body.

[0009] A liquid level gauge and a water pump are arranged in the catchment area. The liquid level gauge is arranged on the catchment area retaining wall in the catchment area. The input end of the water pump is located in the catchment area, and the output end is located in the main treatment area; when the water level exceeds the set liquid level, the water pump automatically starts to convey the initial rainwater to the main treatment area; wherein, a cyclone separator for removing heavy suspended solids is also arranged on the way of the water pump conveying, and the output end of the water pump is connected to the main treatment area through the cyclone separator.

[0010] A dissolved oxygen meter and a blower aeration device are arranged in the main treatment area. Among them, the dissolved oxygen meter controls the on-off of the blower aeration device through the dissolved oxygen concentration in the water in the main treatment area; a gap is reserved between the bottom of the main treatment area retaining wall and the outlet dam, and the gap communicates the main treatment area with the sedimentation and separation area.

[0011] Preferably, the primary rainwater discharge pipe and the mid-late stage rainwater discharge pipe are respectively arranged at different heights.

[0012] Preferably, the outlet dam includes an upper vertical section and a lower inclined section. Among them, the upper vertical section is arranged parallel to the main treatment area retaining wall, and one end of the lower inclined section is fixedly connected to the upper vertical section, and the position where the lower inclined section is connected to the ground is arranged inside the main treatment area retaining wall.

[0013] Preferably, the lower end inclined section is arranged at an angle of ≥60° with the ground.

[0014] Preferably, the elevation of the water outlet dam is the water level height corresponding to the main flood recurrence period of many years, and the elevation of the catchment retaining wall is 300 - 800 mm higher than that of the water outlet dam.

[0015] Preferably, the elevation of the main treatment area retaining wall is the same as that of the water outlet dam.

[0016] Due to the adoption of the above technical solutions, the beneficial effects obtained by the present utility model include:

[0017] 1. The present utility model places the treatment location of the initial rainwater in the water body, and uses cyclone separation combined with biological membrane fillers to treat the pollutants in the initial rainwater, solving the problem of intermittent operation of the complex treatment process for initial rainwater.

[0018] 2. The present utility model can effectively remove the pollutants in the initial rainwater according to the water quality characteristics of the initial rainwater in the rain - sewage separation collection system through the cyclone separator and the biological membrane treatment system, and matches the characteristics of the main pollutants in the initial rainwater, so as to be able to treat the polluted initial rainwater and the non - polluted later rainwater differently, realizing the treatment and separation of polluted rainwater and non - polluted rainwater.

[0019] 3. The structure of the present utility model is simple and the operation control is convenient. Brief Description of the Drawings

[0020] Figure 1 is a schematic plan view of an embodiment of the device for treating initial rainwater in the rain - sewage separation system of the present utility model.

[0021] Figure 2 is a schematic sectional view of an embodiment of the device for treating initial rainwater in the rain - sewage separation system of the present utility model.

[0022] The reference signs in the drawings are as follows:

[0023] 1. Rainwater collection unit; 11. Rainwater discharge pipe; 12. Rainwater discharge pipe;

[0024] 13. Primary rainwater discharge pipe; 14. Middle - and - late - stage rainwater discharge pipe;

[0025] 2. Rainwater treatment unit; 21. Land - water boundary; 22. Catchment retaining wall;

[0026] 23. Main treatment area retaining wall; 24. Water outlet dam; 241. Upper vertical section; 242. Lower end inclined section;

[0027] 25. Catchment area; 251. Liquid level gauge; 252. Water pump; 253. Hydrocyclone separator;

[0028] 26. Main treatment area; 261. Dissolved oxygen meter; 262. Blower aeration equipment;

[0029] 27. Sedimentation and separation area; 28. Main water body; 29. Notch. Detailed implementation mode

[0030] In order to more clearly show the technical content of the present utility model, it will be further described below in conjunction with specific embodiments.

[0031] The collected water volume and pollutant concentration of the initial rainwater are related to the drainage system, the area and layout of the catchment area, the rainfall characteristics and the pollution characteristics. Aiming at the problems of intermittent treatment or insufficient treatment in the existing initial rainwater treatment technology for the rain and sewage diversion collection system, combined with the characteristics of initial rainwater pollutants, that is, the main pollutants are BOD, COD and SS, a treatment device for the initial rainwater of the rain and sewage diversion system is proposed. Specifically, the present utility model places the initial rainwater treatment location inside the water body, makes full use of the huge space owned by the water body itself, and simplifies the initial rainwater treatment process to the way of combining hydrocyclone separation with biological filler biofilm to treat pollutants; so that the dissolved and suspended BOD and COD in the initial rainwater can be effectively removed through biofilm treatment, and only the inorganic part of SS needs to be provided with a special treatment device to avoid the accumulation of non-degradable inorganic substances in the water body to form silt (the total phosphorus and total nitrogen content in the initial rainwater is relatively low, and the ratio of its content to the oxygen demand is suitable for the sewage treatment working condition mainly removing aerobic organic pollutants, and setting a single aerobic treatment unit can effectively remove the main pollutants in the initial rainwater).

[0032] As Figure 1 shown; the present utility model provides a treatment device for the initial rainwater of the rain and sewage diversion system. The treatment device is arranged inside the water body and includes a rainwater collection unit 1 and a rainwater treatment unit 2; wherein, the rainwater collection unit 1 includes a rainwater discharge pipe 11, a primary rainwater discharge pipe 12 and a middle and late stage rainwater discharge pipe 13; wherein, the primary rainwater discharge pipe 12 and the middle and late stage rainwater discharge pipe 13 are respectively vertically connected to the rainwater discharge pipe 11 and form a communication with the rainwater discharge pipe 11; in this embodiment, the primary rainwater discharge pipe 12 and the middle and late stage rainwater discharge pipe 13 are respectively arranged at different heights, and the primary rainwater discharge pipe 12 is located below the middle and late stage rainwater discharge pipe 13. When the liquid in the primary rainwater discharge pipe 12 reaches a certain level, the subsequent inflowing rainwater will directly enter the middle and late stage rainwater discharge pipe 13 for discharge;

[0033] In this embodiment, the rainwater treatment unit 2 includes a land-water boundary 21, a catchment retaining wall 22, a main treatment area retaining wall 23, and an effluent dam 24. Among them, a catchment area 25 is provided between the land-water boundary 21 and the catchment retaining wall 22; a main treatment area 26 is provided between the catchment retaining wall 22 and the main treatment area retaining wall 23; a sedimentation and separation area 27 is provided between the main treatment area retaining wall 23 and the effluent dam 24; a main water body 28 is also provided outside the effluent dam 24.

[0034] Among them, the primary rainwater discharge pipe 12 is interconnected with the catchment area 25 through the land-water boundary 21. In the initial stage of rainfall, the relatively polluted initial rainwater is collected by the initial rainwater discharge pipe 12 into the catchment area 25. The mid-late stage rainwater discharge pipe 13 is directly connected to the main water body 28. And as the rainwater quality in the mid-late stage of rainfall is relatively good and there is no initial rainwater entering the rainwater treatment unit 2, the rainwater in the mid-late stage of rainfall can be directly discharged into the main water body through the mid-late stage rainwater discharge pipe 13.

[0035] As Figure 2 shown, a liquid level gauge 251 and a water pump 252 are provided in the catchment area 25. Among them, the liquid level gauge 251 is arranged on the catchment retaining wall 22 in the catchment area, the input end of the water pump 252 is located in the catchment area 25, and the output end is located in the main treatment area 26. When the water level exceeds the set liquid level, the water pump 252 will automatically start to transport the initial rainwater to the main treatment area 26. Among them, a hydrocyclone 253 for removing heavy suspended solids is also arranged on the way of the water pump 252 for transportation, and the output end of the water pump 252 is connected to the main treatment area 26 through the hydrocyclone 253. And in this embodiment, the working principle of the hydrocyclone 253 is to separate solid particles from the suspended solids by using the centrifugal sedimentation principle, which is a mature technology in the prior art. Regarding its structural characteristics, it will not be elaborated here.

[0036] In this embodiment, a dissolved oxygen meter 261 and a blower aeration device 262 are arranged in the main treatment area 26. Among them, the dissolved oxygen meter 261 controls the on-off of the blower aeration device 262 according to the dissolved oxygen concentration in the water in the main treatment area 26. During the non-rainfall period with a low pollution load, the oxygen in the main treatment area can be supplemented by natural reoxygenation on the water surface for further degradation. And in this device, the on-off dissolved oxygen concentration of the blower aeration device 262 is 1mg / L and 5mg / L (the blower aeration device is an important device in the activated sludge system, used to introduce air into the aeration tank. Among them, the common one is the blower aeration device, which is composed of a blower, a diffusion structure and a distribution pipe. The blower transports air through a series of pipes to the aeration device installed at the bottom of the aeration tank, and through the diffusion structure, the oxygen in the air is transferred into the mixed liquid).

[0037] In this embodiment, a gap 29 is reserved between the bottom of the main treatment area retaining wall 23 and the water outlet dam 24, and the gap 29 connects the main treatment area 26 and the sedimentation and separation area 27. By using this gap, the exfoliated and aged biofilms in the main treatment area and the organic suspended particles that gravitationally flow back to the main treatment area from the sedimentation and separation area can be reciprocally treated at the bottom, facilitating subsequent sufficient purification treatment.

[0038] In this embodiment, the total volume of the main treatment area 26 and the sedimentation and separation area 27 is 5 - 10 times the initial rainwater volume in the catchment area. Its water outlet dam 24 includes an upper vertical section 241 and a lower inclined section 242. Specifically, the upper vertical section 241 is arranged in parallel with the main treatment area retaining wall 23. One end of the lower inclined section 242 is fixedly connected to the upper vertical section 241, and the other end of the lower inclined section 242 is connected to the ground and is set at an angle of ≥60° with the ground. The position where the lower inclined section 242 is connected to the ground is arranged inside the main treatment area retaining wall 23. This setting enables the separated sediment in the sedimentation and separation area to flow back into the main treatment area along the inclined slope of the lower inclined section for secondary treatment; its large-capacity treatment area can ensure that when the initial rainwater enters the main treatment area, the pollutant concentration can be fully diluted, enabling the entire main treatment area to be in a biofilm treatment process with a relatively low pollutant concentration all the time. And the biofilm treatment process is the main method for treating low-concentration pollutants. Therefore, the pollutants in the initial rainwater in this area will be fully degraded and purified. The biofilm system mainly utilizes the high dissolved oxygen conditions of blower aeration or atmospheric reoxygenation. The exfoliated and aged biofilms in the main treatment area and the organic suspended particles that gravitationally flow back to the main treatment area from the sedimentation and separation area will be lifted again to the biofilm packing treatment area by the bottom aeration device to circularly degrade organic pollutants and ammonia nitrogen, etc. By continuously purifying the pollutants in the treatment unit, the effect of not generating excess sludge can be achieved.

[0039] In this embodiment, the elevation of the water outlet dam 24 is the water level height for a multi-year main water body recurrence period (more than 2 years). (The recurrence period is another way of expressing the flood occurrence frequency, with the unit of year). And the elevation of the catchment area retaining wall 22 is 300 - 800 mm higher than that of the water outlet dam, and the elevation of the main treatment area retaining wall 22 is the same as that of the water outlet dam 24. The set elevation of the water outlet dam 24 here can prevent the water in the main water body from flowing back and mixing, and discharging the untreated initial rainwater into the main water body. When the water level of the main water body reaches the high water level with a multi-year recurrence period, its excessive rainfall will greatly dilute the pollutants in the initial rainwater, significantly reducing its pollutant concentration, and the impact of the discharged pollutants on the main water body will be minimized.

[0040] Usage method of the utility model: In the initial stage of rainfall, relatively polluted initial rainwater is collected by the initial rainwater discharge pipeline and sent to the catchment area; when the water level flowing into the catchment area exceeds the set liquid level, the water pump is automatically turned on, and the initial rainwater enters the main treatment area after removing heavy suspended solids through a hydrocyclone separator; after the main treatment area removes the pollutants carried by the dissolved or residual suspended solids in the initial rainwater, the purified rainwater is obtained after solid-liquid separation in the sedimentation separation area and discharged into the main water body; since the rainwater quality in the middle and late stages of rainfall is relatively good and no initial rainwater enters the rainwater treatment unit, the rainwater in the middle and late stages of rainfall can be directly discharged into the main water body through the late rainwater discharge pipeline.

[0041] It should be noted that: The utility model places the treatment location of the initial rainwater in the water body and adopts a combination of hydrocyclone separation and biological membrane packing to treat the pollutants in the initial rainwater, solving the problem of intermittent operation of the complex treatment process of the initial rainwater; at the same time, according to the water quality characteristics of the initial rainwater in the rain-sewage separation collection system, the pollutants in the initial rainwater can be effectively removed through the hydrocyclone separator and the biological membrane treatment system, and it matches the main pollutant characteristics of the initial rainwater (i.e., the main pollutants are BOD, COD, ammonia nitrogen, etc.), so that the polluted initial rainwater and the non-polluted late rainwater can be treated differently, realizing the treatment diversion of polluted rainwater and non-polluted rainwater; and the utility model has a simple structure and convenient operation control.

[0042] The above relevant descriptions and the descriptions of the embodiments are for the convenience of those of ordinary skill in the art to understand and apply the utility model. Obviously, those who are familiar with the technology in this field can easily make various modifications to these contents and apply the general principles described here to other embodiments without creative labor. Therefore, the utility model is not limited to the above relevant descriptions and the descriptions of the embodiments, and the improvements and modifications made by those skilled in the art without departing from the scope of the utility model according to the disclosure of the utility model should be within the protection scope of the utility model.

Claims

1. A device for treating initial rainwater in a rainwater-sewage diversion system, characterized in that: The processing device is arranged in the water body and comprises a rainwater collection unit and a rainwater processing unit. The rainwater collection unit comprises a rainwater discharge pipe, a primary rainwater discharge pipe and a mid- and late-stage rainwater discharge pipe; wherein the primary rainwater discharge pipe and the mid- and late-stage rainwater discharge pipe are respectively vertically connected to the rainwater discharge pipe and communicate with the rainwater discharge pipe; The rainwater treatment unit comprises a land-water boundary, a water collection area retaining wall, a main treatment area retaining wall and a water outlet dam; wherein a water collection area is arranged between the land-water boundary and the water collection area retaining wall; a main treatment area is arranged between the water collection area retaining wall and the main treatment area retaining wall; a sedimentation separation area is arranged between the main treatment area retaining wall and the water outlet dam; and a main water body is also arranged outside the water outlet dam; Wherein, the primary rainwater discharge pipeline is interconnected with the water catchment area through the land-water boundary; the mid- and late-stage rainwater discharge pipeline is directly connected with the main water body; A liquid level meter and a water pump are provided in the water collection area. The liquid level meter is provided on the water collection area retaining wall in the water collection area. The input end of the water pump is located in the water collection area, and the output end is located in the main treatment area. When the water level exceeds the set liquid level, the water pump automatically starts to transport the initial rainwater to the main treatment area. A gap is reserved between the bottom of the retaining wall of the main treatment area and the outlet dam, and the gap connects the main treatment area with the sedimentation and separation area.

2. The device for treating initial rainwater in a rainwater-sewage diversion system according to claim 1, characterized in that: A cyclone separator for removing heavy suspended matter is also provided on the way of the water pump, and the output end of the water pump is connected to the main processing area through the cyclone separator.

3. The device for treating initial rainwater in a rainwater-sewage diversion system according to claim 1, characterized in that: The main treatment area is provided with a dissolved oxygen meter and aeration equipment.

4. The device for treating initial rainwater in a rainwater-sewage diversion system according to claim 3, characterized in that: The dissolved oxygen meter controls the aeration equipment to switch on and off according to the dissolved oxygen concentration in the water in the main treatment area.

5. The device for treating initial rainwater in a rainwater-sewage diversion system according to claim 1, characterized in that: The primary rainwater discharge pipe and the mid- and late-stage rainwater discharge pipe are respectively arranged at different heights.

6. The device for treating initial rainwater in a rainwater-sewage diversion system according to claim 1, characterized in that: The outlet dam comprises an upper vertical section and a lower inclined section.

7. The device for treating initial rainwater in a rainwater-sewage diversion system according to claim 6 is characterized in that: The upper vertical section is arranged parallel to the retaining wall of the main processing area, one end of the lower inclined section is fixedly connected to the upper vertical section, and the other end of the lower inclined section is connected to the ground, and the position of the connection between the lower inclined section and the ground is arranged inside the retaining wall of the main processing area.

8. The device for treating initial rainwater in a rainwater-sewage diversion system according to claim 7, characterized in that: The lower end inclined section is arranged at an angle of ≥60° to the ground.

9. The device for treating initial rainwater in a rainwater-sewage diversion system according to claim 1, characterized in that: The elevation of the water collection area retaining wall is 300-800mm higher than the outlet dam.

10. The device for treating initial rainwater in a rainwater-sewage diversion system according to claim 1, characterized in that: The elevation of the retaining wall of the main treatment area is consistent with the elevation of the outlet dam.

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