Sewage treatment and rainwater collection and purification system for expressway service area

Abstract

The invention relates to a sewage treatment and rainwater collection and purification system for an expressway service area, which mainly comprises two subsystems, namely a sewage treatment system and a rainwater collection and purification system, and the sewage treatment system and the rainwater collection and purification system are converged in a final clean water tank and jointly provide recycled water sources for various water demands of the service area. The sewage treatment system comprises a grating, a grit chamber, a CASS (cyclic activated sludge system) tank, a sewage contact disinfection tank and a clean water tank which are connected in sequence; the CASS tank is connected with a sludge concentration tank; and the sludge in the sludge concentration tank is transported outwards. The rainwater collecting and purifying system comprises a split-flow filtering device, a rainwater storage tank, a rainwater settling tank, a rainwater filtering tank, a rainwater contact disinfecting tank and a clean water tank which are connected in sequence. By means of the system, efficient cyclic utilization of water resources in the expressway service area is achieved, environmental pollution is relieved, the ecological system is protected, and the sustainability of the expressway service area is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of sewage treatment and rainwater collection and utilization, and particularly relates to an efficient sewage treatment and rainwater collection and purification system applied to highway service areas, as well as a supporting advanced sewage treatment method. The system aims to improve the optimal utilization of water resources in highway service areas to meet the requirements of environmental protection and sustainable development. Through innovative technical means, the optimization and efficiency improvement of the sewage treatment and rainwater treatment processes are realized. Background Art

[0002] As our requirements for water pollution control become increasingly strict, especially with the significant increase in the number of tourists traveling currently, the passenger capacity of highways has also increased greatly, and the amount of sewage and wastewater generated in highway service areas is also increasing. Therefore, the recycling and treatment of sewage and wastewater in highway service areas become even more important. Collecting and reusing rainwater in highway service areas is also a strong response to the recycling of water resources and the prevention and control of water pollution, which helps to promote the green and low-carbon development process of the region. The present invention can effectively utilize the sewage and collected rainwater generated in highway service areas and can well solve the problems of water resource pollution and waste. Summary of the Invention

[0003] The core technical problem to be solved by the present invention is to provide a high-efficiency sewage treatment and rainwater collection and utilization system for highway service areas. This system can not only effectively achieve the high-efficiency resource utilization of sewage, but also effectively collect and utilize rainwater, providing strong support for protecting the balance and health of the surrounding ecological system. By integrating advanced sewage purification and reuse technologies, the system ensures that the treated sewage and rainwater can meet high-standard water quality requirements and are applicable to a variety of non-drinking water application scenarios. In addition, the implementation of this system also promotes the recycling of resources and conforms to the environmental protection concept of green and low-carbon.

[0004] To solve the above problems, the specific technical solution of the present invention is as follows:

[0005] A sewage treatment and rainwater collection and purification system for highway service areas includes a sewage treatment system and a rainwater collection and purification system; the sewage treatment system includes a grille, a grit chamber, a CASS tank, a sewage contact disinfection tank, and a clear water tank connected in sequence; the CASS tank is also connected to a sludge thickening tank, and the sludge outlet of the sludge thickening tank is connected to a spiral press sludge dewatering machine; the rainwater collection and purification system includes a rainwater collection pipe network and a purification system; the purification system includes a flow-through filter device, a rainwater storage tank, a rainwater sedimentation tank, a rainwater filter tank, a rainwater contact disinfection tank, and a clear water tank connected in sequence.

[0006] Preferably, in the above-mentioned sewage treatment and rainwater collection and purification system for highway service areas, the grit chamber is a horizontal flow grit chamber, and the slope of the bottom of the tank is not less than 0.05.

[0007] Preferably, for a sewage treatment and rainwater collection and purification system in a highway service area, the CASS tank is built with concrete and steel bars, with dimensions of 20m×9.9m, and the area ratio of the pre-reaction zone to the main reaction zone is 1:9.

[0008] Preferably, for a sewage treatment and rainwater collection and purification system in a highway service area, a dosing system is provided in the sewage contact disinfection tank.

[0009] More preferably, for a sewage treatment and rainwater collection and purification system in a highway service area, the disinfectant in the dosing system is liquid chlorine.

[0010] Preferably, for a sewage treatment and rainwater collection and purification system in a highway service area, a flow metering device is provided between the sewage contact disinfection tank and the clear water tank.

[0011] Preferably, for a sewage treatment and rainwater collection and purification system in a highway service area, a supernatant reflux pipeline is provided from the sludge thickening tank to the CASS tank.

[0012] Preferably, for a sewage treatment and rainwater collection and purification system in a highway service area, when the flow-through filtration device exceeds the set interception water volume, the remaining water volume enters the rainwater collection pipe network.

[0013] Preferably, for a sewage treatment and rainwater collection and purification system in a highway service area, a rainwater lift pump is provided in the rainwater storage tank.

[0014] A treatment method based on the above sewage treatment and rainwater collection and purification system in a highway service area includes the following steps:

[0015] 1) After the sewage in the highway service area converges, it first flows through a submersible sewage pump to a grille, where larger suspended solid particles are filtered out. The filtered sewage flows by gravity into the grit chamber due to the height difference between the structures.

[0016] 2) Then it enters the CASS tank, and the supernatant from the sludge thickening tank also flows back to the CASS tank. The pollutants are treated by the action of activated sludge.

[0017] 3) Then the sewage is disinfected in the sewage contact disinfection tank and enters the clear water tank.

[0018] 4) The sludge in the CASS tank flows into the sludge thickening tank and is dehydrated by a spiral press sludge dewatering machine to form sludge cakes, which are transported out of the sludge.

[0019] 5) Collect the rainwater from the roof, road, and square and channel it into the rainwater collection pipe network. The collected rainwater first passes through a flow diversion and filtration device to intercept the initial runoff of rainfall. The runoff thickness is set according to the rainwater quality. When the intercepted water volume reaches the set value, the flow diversion ends, and the rainwater enters the rainwater storage tank;

[0020] 6) The rainwater in the rainwater storage tank successively enters the rainwater sedimentation tank, rainwater filtration tank, and rainwater contact disinfection tank for treatment, and the treated rainwater flows by gravity into the clear water tank;

[0021] 7) The clear water is pressurized by the clear water pump in the clear water tank and then reused.

[0022] This application adopts the above technical solutions and has the following beneficial effects:

[0023] 1. The present invention effectively provides a sewage treatment system for highway service areas. The system has fewer structures and a small footprint, making it suitable for installation and use in small sites such as highway service areas.

[0024] 2. The CASS process adopted by the present invention has multiple significant advantages such as high automation, convenient operation and maintenance, low subsequent energy consumption, durable core equipment, and few maintenance requirements, which greatly reduces the operation and maintenance costs and far exceeds the traditional process. This process not only easily meets the high discharge standards of the country and localities, but also creates more considerable economic benefits in practical applications, achieving a win-win situation for environmental protection and economy.

[0025] 3. The setting of the sludge dewatering device of the present invention effectively achieves the goals of sludge reduction, stabilization, and harmless treatment, thereby greatly reducing the risk of secondary pollution that sludge may cause to the environment.

[0026] 4. The setting of the flow measurement equipment of the present invention can accurately measure the sewage discharge volume, providing data support for the rational utilization and management of water resources.

[0027] 5. The present invention aims at the common problems encountered in highway service areas and provides a practical solution path. By adopting the CASS process for treatment, the effluent quality is significantly improved and finally reaches the reclaimed water standard. This achievement not only significantly reduces the production cost but also highly conforms to the sustainable development concept of green environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the sewage treatment and rainwater collection and purification system for highway service areas.

[0029] Figure 2 It is an effect diagram of the CASS tank layout.

[0030] Among them, 1 - grille, 2 - grit chamber, 3 - CASS tank, 4 - sewage contact disinfection tank, 5 - clear water tank, 6 - sludge thickening tank, 7 - spiral sludge dewatering machine, 8 - flow-through filtration device, 9 - rainwater storage tank, 10 - rainwater sedimentation tank, 11 - rainwater filtration tank, 12 - rainwater contact disinfection tank, 13 - chemical dosing system, 14 - flow measurement equipment, 15 - rainwater lift pump. Detailed implementation mode

[0031] Example 1

[0032] As Figure 1 shown, a sewage treatment and rainwater collection and purification system for highway service areas includes a sewage treatment system and a rainwater collection and purification system.

[0033] The sewage treatment system includes a grille 1, a grit chamber 2, a CASS tank 3, a sewage contact disinfection tank 4, and a clear water tank 5 connected in sequence; the CASS tank 3 is also connected to the sludge thickening tank 6, and there is an upper clear liquid return pipeline from the sludge thickening tank 6 to the CASS tank 3. The sludge in the sludge thickening tank 6 is transported out of the sludge through the spiral sludge dewatering machine 7.

[0034] The grit chamber 2 is a horizontal flow grit chamber, and the slope of the bottom of the tank is not less than 0.05, which serves to remove suspended solids, microorganisms, and fine particles.

[0035] As Figure 2 shown, the CASS tank 3 is built of reinforced concrete, with dimensions of 20m × 9.9m, and the area ratio of the pre-reaction zone to the main reaction zone is 1:9 to reduce civil engineering construction.

[0036] A chemical dosing system 13 is arranged in the sewage contact disinfection tank 4, and the disinfectant in the chemical dosing system 13 is liquid chlorine. Equipment operating for 2 hours per day is selected to save energy.

[0037] Flow measurement equipment 14 is provided between the sewage contact disinfection tank 4 and the clear water tank 5 to accurately measure the sewage discharge.

[0038] The rainwater collection and purification system includes a rainwater collection pipe network and a purification system.

[0039] The purification system includes a flow-through filtration device 8, a rainwater storage tank 9, a rainwater sedimentation tank 10, a rainwater filtration tank 11, a rainwater contact disinfection tank 12, and a clear water tank 5 connected in sequence.

[0040] When the flow-through filtration device 8 exceeds the set interception water volume, the remaining water volume enters the rainwater collection pipe network.

[0041] A rainwater lift pump 15 is arranged in the rainwater storage tank 9 to lift the rainwater to the rainwater sedimentation tank 10.

[0042] In this embodiment, the outlet of the clean water tank 5 can be connected to a drain pipe so that the qualified water can be directly discharged; or, the outlet of the clean water tank 5 can be connected to a water unit of a highway service area through a return pipe so that the water treated by the sewage treatment system can be returned to the water unit, thereby realizing the recycling of sewage. The qualified water can be discharged into the drain pipe or the water unit through a pump.

[0043] The treatment method based on the above-mentioned highway service area sewage treatment and rainwater collection and purification system includes the following steps:

[0044] 1) After the sewage from the highway service area is combined and passes through the submersible sewage pump, it first flows to the screen 1, where larger suspended particles can be filtered and removed. The filtered sewage flows into the sand settling tank 2 by gravity due to the height difference between the structures. Two mechanical screens are installed, with a screen width of 500mm and a screen gap of 3mm. Two submersible sewage pumps are installed, with a head of 9m and a flow rate of 10m 3 / h;

[0045] 2) Then it enters the CASS pool 3, and the supernatant of the sludge concentration pool 6 is also returned to the CASS pool 3 through the supernatant return pipeline, and the pollutants are treated by the action of activated sludge. A regulating valve is set at the water inlet end of the CASS pool 3 to adjust the flow rate at any time according to the actual situation;

[0046] 3) After the CASS process, the pollutants in the sewage are effectively removed, but the sewage still needs to pass through the sewage contact disinfection tank 4 to achieve the disinfection effect; the disinfected water enters the clean water tank 5, and a flow metering device 14 is provided between the sewage contact disinfection tank 4 and the clean water tank 5, which can accurately measure the discharge amount of sewage;

[0047] 4) The sludge in the CASS tank 3 flows into the sludge thickening tank 6, and is dehydrated by the screw stacking sludge dewatering machine 7 to form a sludge cake, which is then transported out.

[0048] 5) Rainwater flows through roofs, roads, squares, etc. and flows into the rainwater collection network. The early rainfall is discharged into the rainwater collection network. The thickness of the initial discarded flow of roof rainwater is 1-2mm. The early rainwater discarding device adopts an automatic discarding flow filtering device 8. The rainwater collected after the discarded flow flows into the rainwater storage tank 9;

[0049] 6) The rainwater storage tank 9 is a concrete storage tank with a single size of 1000mm×500mm×400mm. A rainwater lifting pump 15 is provided in the concrete storage tank to lift rainwater to the rainwater sedimentation tank 10. No power is required. The potential energy formed by the drop in the pool allows the rainwater to pass through the rainwater sedimentation tank 10, the rainwater filtration tank 11, and the rainwater contact disinfection tank 12 in sequence;

[0050] 7) The treated water flows by gravity into the clean water tank 5; the clean water is pressurized by the clean water pump in the clean water tank 5 and supplied to the reuse water network for reuse.

Claims

1. A highway service area sewage treatment and rainwater collection and purification system, characterized in that: The invention comprises a sewage treatment system and a rainwater collection and purification system; the sewage treatment system comprises a grille (1), a grit chamber (2), a CASS chamber (3), a sewage contact disinfection chamber (4), and a clear water chamber (5) which are connected in sequence; the CASS chamber (3) is also connected to a sludge concentration chamber (6), and the sludge outlet of the sludge concentration chamber (6) is connected to a spiral-stacked sludge dewatering machine (7); the rainwater collection and purification system comprises a rainwater collection pipe network and a purification system; the purification system comprises a discarded flow filtering device (8), a rainwater storage tank (9), a rainwater sedimentation tank (10), a rainwater filtering tank (11), a rainwater contact disinfection chamber (12), and a clear water chamber (5) which are connected in sequence.

2. A highway service area sewage treatment and rainwater collection and purification system according to claim 1, characterized in that: The grit chamber (2) is a horizontal flow grit chamber, and the slope of the chamber bottom is not less than 0.

05.

3. A highway service area sewage treatment and rainwater collection and purification system according to claim 1, characterized in that: The CASS tank (3) is made of concrete and steel bars, with a size of 20m×9.9m, and the ratio of the area of ​​the pre-reaction zone to the main reaction zone is 1:

9.

4. A highway service area sewage treatment and rainwater collection and purification system according to claim 1, characterized in that: A drug adding system (13) is provided in the sewage contact disinfection tank (4).

5. A highway service area sewage treatment and rainwater collection and purification system according to claim 4, characterized in that: The disinfectant in the dosing system (13) is liquid chlorine.

6. A highway service area sewage treatment and rainwater collection and purification system according to claim 1, characterized in that: A flow metering device (14) is provided between the sewage contact disinfection tank (4) and the clean water tank (5).

7. A highway service area sewage treatment and rainwater collection and purification system according to claim 1, characterized in that: A supernatant liquid return pipeline is provided between the sludge thickening tank (6) and the CASS tank (3).

8. A highway service area sewage treatment and rainwater collection and purification system according to claim 1, characterized in that: When the discarded flow filtering device (8) exceeds the set intercepted water volume, the remaining water enters the rainwater collection network.

9. A highway service area sewage treatment and rainwater collection and purification system according to claim 1, characterized in that: A rainwater lifting pump (15) is provided in the rainwater storage tank (9).

10. A method for treating sewage in highway service areas and collecting and purifying rainwater based on the system of claim 1, characterized in that: The following steps are involved: 1) After the sewage from the highway service area is combined, it flows to the screen (1) through a submersible sewage pump, where it is filtered to remove larger suspended particles. The filtered sewage flows into the grit chamber (2) by gravity due to the height difference between the structures; 2) Then it enters the CASS tank (3), and the supernatant of the sludge thickening tank (6) also flows back to the CASS tank (3) to treat the pollutants by using the action of activated sludge; 3) The sewage is then disinfected in the sewage contact disinfection tank (4) and then enters the clean water tank (5); 4) The sludge in the CASS tank (3) flows into the sludge thickening tank (6), and is dehydrated by the screw-type sludge dewatering machine (7) to form a sludge cake, which is then transported out; 5) Rainwater from roofs, roads and squares is collected and enters the rainwater collection network. The collected rainwater first passes through a discard filter device (8) to intercept the initial runoff of rainfall. The runoff thickness is set according to the quality of the rainwater. When the intercepted water volume reaches the set value, the discard ends and the rainwater enters a rainwater storage tank (9); 6) The rainwater in the rainwater storage tank (9) enters the rainwater sedimentation tank (10), the rainwater filtration tank (11) and the rainwater contact disinfection tank (12) in sequence for treatment, and the treated rainwater flows by gravity into the clear water tank (5); 7) The clean water is pressurized by the clean water pump in the clean water tank (5) and then reused.

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