Comprehensive utilization system and method for water resources in expressway service area

Abstract

The invention relates to an expressway service area water resource comprehensive utilization system and method, and belongs to the technical field of rainwater and sewage collection, treatment and utilization. The system structurally comprises a rainwater collection and treatment system and a sewage collection and treatment system, the rainwater collection and treatment system comprises a discarding device, an underground water storage tank, a mechanical grid I, a vertical flow sedimentation tank, a filter, a disinfection tank I and a clean water tank which are communicated in sequence, and further comprises a sludge tank communicated with the vertical flow sedimentation tank; the sewage collecting and treating system comprises a septic tank, a mechanical grating II, a sewage regulating tank, an anaerobic tank, an anoxic tank, an aerobic tank, a radial-flow secondary sedimentation tank, an MBR reaction tank, a disinfection tank II and a clean water tank which are communicated in sequence, and further comprises a sludge tank which is communicated with the radial-flow secondary sedimentation tank and the MBR reaction tank respectively. The system effectively collects and treats rainwater and sewage, is used for car washing, toilet flushing, irrigation and the like in a service area, and has certain environmental benefits, social benefits and economic benefits.

Description

Technical Field

[0001] The invention belongs to the technical field of water resource collection, treatment and utilization, and particularly relates to a comprehensive water resource utilization system and method for highway service areas. Background Art

[0002] In the severe situation of global water shortage, the efficient utilization and recycling of water resources have become key issues attracting much attention. As a specific unit of water consumption, highway service areas, due to their unique functional positioning, are characterized by large and relatively concentrated water consumption. Therefore, realizing the recycling of water resources has important demonstration significance.

[0003] Implementing water resource recycling technology can deeply reduce and transform pollutants in sewage, remove harmful substances such as organic matter, nitrogen and phosphorus nutrients, heavy metals, etc., reduce the potential risks of sewage discharge to the surrounding water environment and soil environment, and protect the ecological environment around the service area. Summary of the Invention

[0004] The invention provides a comprehensive water resource utilization system for highway service areas, which can effectively collect and treat rainwater and sewage and be used for car washing, toilet flushing, irrigation, etc. in the service area, having certain environmental, social and economic benefits.

[0005] The specific technical solution of the invention is as follows:

[0006] A comprehensive water resource utilization system for highway service areas includes a rainwater collection and treatment system and a sewage collection and treatment system; the rainwater collection and treatment system includes a flow diversion device, an underground storage tank, a mechanical grille I, a vertical flow sedimentation tank, a filter, a disinfection tank I and a clear water tank connected in sequence, and also includes a sludge tank connected to the vertical flow sedimentation tank; the sewage collection and treatment system includes a septic tank, a mechanical grille II, a sewage regulation tank, an anaerobic tank, an anoxic tank, an aerobic tank, a radial flow secondary sedimentation tank, an MBR reaction tank, a disinfection tank II and a clear water tank connected in sequence, and also includes sludge tanks respectively connected to the radial flow secondary sedimentation tank and the MBR reaction tank.

[0007] Further, in the above-mentioned comprehensive water resource utilization system for highway service areas, when the flow diversion device exceeds the set intercepted water volume, the remaining water volume enters the rainwater treatment system.

[0008] Further, in the above-mentioned comprehensive water resource utilization system for highway service areas, the filtering device adopts a DN200 type fully automatic self-cleaning filter.

[0009] Further, in the above-mentioned comprehensive water resource utilization system for highway service areas, sludge return pipes are respectively provided between the radial flow secondary sedimentation tank and the anaerobic tank, and between the radial flow secondary sedimentation tank and the anoxic tank.

[0010] Further, in the above-mentioned comprehensive water resource utilization system for highway service areas, a water return pipe is provided from the aerobic tank to the anoxic tank.

[0011] The method for collecting and treating water resources in highway service areas by the comprehensive water resource utilization system for highway service areas described in any one of the above includes the following steps:

[0012] 1) Rainwater on the roof and road is first intercepted by a runoff diversion device for 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 runoff diversion ends, and the rainwater enters the underground storage tank.

[0013] 2) The rainwater is treated by a combined process of being intercepted by a mechanical grille I, sedimented in a vertical flow sedimentation tank, filtered by a filter, and disinfected in a disinfection tank I.

[0014] 3) Sewage pretreatment is to sequentially treat domestic and car wash sewage through a septic tank, intercept it with a mechanical grille II, and adjust the raw water volume and quality in a sewage regulation tank. The effluent is lifted by a primary lift pump and then transported to advanced sewage treatment.

[0015] 4) Advanced sewage treatment adopts a process combining AAO and MBR, including treatment in an anaerobic tank, anoxic tank, aerobic tank, radial flow secondary sedimentation tank, and MBR reaction tank.

[0016] 5) The effluent from the MBR reaction tank enters the disinfection tank II for disinfection.

[0017] 6) The effluents from the disinfection tank I and the disinfection tank II are combined in a clear water tank for reuse and irrigation.

[0018] 7) The sludge generated in the vertical flow sedimentation tank, radial flow secondary sedimentation tank, and MBR reaction tank is regularly discharged and lifted to the sludge tank, and after aerobic digestion, it is regularly transported out by the sanitation department.

[0019] Further, in the above method, in step 2), the disinfection is carried out by adding chlorine dioxide, and the effective chlorine dosage is 7 mg / L.

[0020] Further, in the above method, in step 5), the disinfection is carried out by adding chlorine dioxide, and the effective chlorine dosage is 10 mg / L.

[0021] Further, in the above method, in step 4), the DO in the anaerobic tank is controlled at <0.2 mg / L, and anaerobic decomposition is carried out for 1 - 2 h.

[0022] Further, in the above method, in step 4), a stirring device is provided in the anoxic tank, and the DO is controlled at ≤0.5 mg / L.

[0023] Further, in step 4) of the above method, the aerobic tank is a biological treatment device mainly using the biofilm method and also having the activated sludge method. The oxygen source is provided by a rotary blower, and aerobic microorganisms and autotrophic bacteria existing in the aerobic tank are fully utilized to degrade organic pollutants. The aeration in the aerobic tank adopts perforated pipe aeration.

[0024] Furthermore, in the above method, the biofilm carrier adopts semi-soft elastic packing.

[0025] The beneficial effects of the present invention are as follows:

[0026] 1. Compared with the prior art, the comprehensive water resource utilization system and method for highway service areas of the present invention can avoid the problem of waste of water resource discharge in highway service areas, collect and treat rainwater resources for reuse in car washing, toilet flushing, irrigation, etc. in the service area, and have certain environmental benefits, social benefits and economic benefits.

[0027] 2. The system of the present invention adopts a comprehensive rainwater collection system, combines roof and ground rainwater collection methods, efficiently collects rainwater, and improves the utilization rate of rainwater resources. In the sewage treatment process, the pretreatment selects a septic tank + mechanical grille + sewage regulation tank, which can effectively adapt to the fluctuation of water quality and quantity, and reduce the subsequent treatment load; the biochemical treatment adopts the AAO process, which has good nitrogen and phosphorus removal and organic matter removal capabilities and strong shock resistance; the advanced treatment selects the MBR process, with excellent effluent quality, which can meet various reuse requirements in the service area, and has a small floor area, high automation degree and low sludge yield. Description of the Drawings

[0028] Figure 1 It is a schematic flow chart of the comprehensive water resource utilization system for highway service areas.

[0029] Figure 2 It is a schematic structural diagram of the aerobic tank. Detailed Embodiments

[0030] Example 1

[0031] As Figure 1As shown in the figure, an integrated water resource utilization system for highway service areas includes a rainwater collection and treatment system and a sewage collection and treatment system. The integrated water resource utilization system for highway service areas collects rainwater from roofs and roads, as well as domestic and car wash sewage, and feeds them into the water resource collection and treatment system. The rainwater collection and treatment system includes a runoff diversion device, an underground storage tank, a mechanical grille I, a vertical flow sedimentation tank, a filter, a disinfection tank I, and a clear water tank connected in sequence, and also includes a sludge tank connected to the vertical flow sedimentation tank. The sewage collection and treatment system includes a septic tank, a mechanical grille II, a sewage regulation tank, an anaerobic tank, an anoxic tank, an aerobic tank, a radial flow secondary sedimentation tank, an MBR reaction tank, a disinfection tank II, and a clear water tank connected in sequence, and also includes sludge tanks connected to the radial flow secondary sedimentation tank and the MBR reaction tank respectively.

[0032] When the runoff diversion device exceeds the set intercepted water volume, the remaining water volume enters the rainwater treatment process.

[0033] The filtering device adopts a full-automatic self-cleaning filter of DN200 type.

[0034] A method for collecting and treating water resources in highway service areas using the above integrated water resource utilization system for highway service areas includes the following steps:

[0035] 1) Rainwater collection:

[0036] Rainwater from roofs and roads is first collected. During the process, a runoff diversion operation is carried out to discard the initially dirty rainwater to avoid excessive pollutants entering the subsequent treatment links. The initial runoff of rainfall is intercepted by the runoff diversion device, and the runoff thickness is set according to the rainwater quality. When the intercepted water volume reaches the set value, the runoff diversion ends. The rainwater after runoff diversion enters the underground storage tank for temporary storage, providing a stable water source supply for subsequent treatment.

[0037] 2) Rainwater pretreatment:

[0038] It includes a mechanical grille I and a vertical flow sedimentation tank: The rainwater flowing out of the underground storage tank passes through the mechanical grille I to intercept larger suspended solids and impurities, such as branches and garbage, and then passes through the vertical flow sedimentation tank. Using the gravity effect, heavier particles such as sediment in the rainwater settle to the bottom of the tank, removing part of the solid impurities.

[0039] 3) Rainwater sedimentation:

[0040] Rainwater filtration: The precipitated rainwater enters the filter (a full-automatic self-cleaning filter of DN200 type) to further remove smaller suspended solids and colloidal impurities, etc., improving the water quality.

[0041] 4) Rainwater disinfection:

[0042] Finally, the rainwater enters the disinfection tank I, and disinfectant ClO 2(Effective chlorine dosage 7mg / L) kills bacteria, viruses and other microorganisms in the water. The treated water enters the clean water pool and can be reused for car washing, landscaping, flushing toilets, etc.

[0043] 5) Sewage pretreatment:

[0044] It includes septic tank, mechanical screen II, and sewage regulating tank. After simple treatment in the septic tank, domestic and car wash sewage flows into the sewage regulating tank through mechanical screen II. The effluent from the sewage regulating tank is lifted by a primary lifting pump and transported to the subsequent conventional biochemical treatment system. Pretreatment of sewage can effectively remove part of the COD cr 、BOD 5 , reducing the load of the subsequent treatment system. Mechanical screen II is set to intercept larger floating materials in the raw sewage to prevent clogging of pipes and water pumps. Septic tanks and mechanical screen II are cleaned manually regularly. The sewage regulating tank effectively regulates the amount of raw sewage through its own volume and pre-aeration, equalizes the water quality of raw sewage, and prevents the precipitation of fine suspended matter.

[0045] 6) Conventional biochemical treatment of sewage (AAO process):

[0046] It includes anaerobic tank, anoxic tank and aerobic tank. The effluent from the sewage regulating tank and the return sludge from the radial flow secondary sedimentation tank first enter the anaerobic tank (DO<0.2mg / L) for complete mixing. After a certain period of anaerobic decomposition (1-2h), part of the BOD is removed and part of the nitrogen-containing compounds are converted into N 2 (denitrification), and the polyphosphate microorganisms (polyphosphate bacteria, etc.) in the return sludge release phosphorus to meet the bacteria's demand for phosphorus. A stirring device is installed in the anoxic tank to control DO≤0.5mg / L. The effluent from the anaerobic tank and the return sludge from the radial flow secondary sedimentation tank enter at the same time. The denitrifying bacteria use organic matter as a carbon source to convert the nitrate nitrogen in the internal circulation nitrification liquid into gaseous nitrogen (N). No external carbon source is required. The mixed liquid enters the aerobic tank for oxidation, ammoniation and nitrification of organic matter. The aerobic tank is the main place for biochemical treatment. This tank is a biological treatment device that mainly uses the biofilm method and has an activated sludge method. The oxygen source is provided by a rotary blower, and the aerobic microorganisms and autoaerobic bacteria (nitrifying bacteria) in the aerobic tank are fully utilized to degrade organic pollutants. The biofilm carrier uses a semi-soft elastic filler, which has a large specific surface area, is easy to hold the film, and is not easy to cause the biofilm to form pellets. The air distribution in the aerobic tank uses perforated pipe air distribution (such as Figure 2 ), the device has the characteristics of fine bubbles, high oxygen utilization rate and uniform gas distribution. The effluent from the aerobic pool is returned to the anoxic pool for circulation treatment at a reflux ratio of about 150% through a reflux pump, creating a biochemical environment that is conducive to the smooth progress of nitrification and denitrification reactions, thereby effectively degrading nitrogen substances such as ammonia nitrogen. The effluent from the aerobic pool contains detached biofilm and high suspended solids, and enters the radial flow secondary sedimentation tank. Conventional sewage biochemical treatment systems can remove CODCr , BOD 5 In addition, it can mainly meet the current requirements for phosphorus and nitrogen.

[0047] 7) Radial flow sedimentation tank: It can efficiently remove suspended solids and particulate matters in water. When sewage enters the radial flow sedimentation tank through the central pipe, under the action of water flow characteristics, it flows along the radial direction in the tank, forming a unique radial water flow. During this process, gravity causes the suspended solids and particulate matters in the water to gradually sink and finally deposit at the bottom of the tank.

[0048] 8) Sewage MBR reaction tank:

[0049] The MBR reaction tank (membrane bioreactor) process is a new type of sewage treatment technology that organically combines membrane separation technology and biological treatment technology. It uses membrane separation equipment to intercept the activated sludge and macromolecular organic matters in the tank. Therefore, the concentration of activated sludge can be greatly increased, and the hydraulic retention time (HRT) and sludge retention time (SRT) can be controlled respectively. And the refractory substances continuously react and degrade in the MBR reaction tank. Therefore, the MBR reaction tank process greatly strengthens the function of the biological reaction tank through membrane separation technology.

[0050] 9) Sewage disinfection treatment:

[0051] The effluent from the MBR reaction tank enters Disinfection Tank II, and the disinfection is carried out by adding ClO 2 , and the effective chlorine dosage is 10 mg / L. After the water is disinfected, it enters the clear water tank for reuse.

[0052] 10) Sludge treatment:

[0053] A small amount of excess sludge generated from the vertical flow sedimentation tank, radial flow secondary sedimentation tank and MBR reaction tank is regularly discharged and lifted to the sludge tank, and after aerobic digestion, it is regularly transported out by the sanitation department.

Claims

1. A highway service area water resources comprehensive utilization system, characterized in that: The system includes a rainwater collection and treatment system and a sewage collection and treatment system; the rainwater collection and treatment system includes a discarding device, an underground water storage tank, a mechanical screen I, a vertical flow sedimentation tank, a filter, a disinfection tank I and a clear water tank connected in sequence, and also includes a sludge tank connected to the vertical flow sedimentation tank; the sewage collection and treatment system includes a septic tank, a mechanical screen II, a sewage regulating tank, an anaerobic tank, an anoxic tank, an aerobic tank, a radial flow secondary sedimentation tank, an MBR reaction tank, a disinfection tank II and a clear water tank connected in sequence, and also includes a sludge tank connected to the radial flow secondary sedimentation tank and the MBR reaction tank respectively.

2. A highway service area water resource comprehensive utilization system according to claim 1, characterized in that: When the flow-discarding device exceeds the set interception water volume, the remaining water enters the rainwater treatment system.

3. A highway service area water resource comprehensive utilization system according to claim 1, characterized in that: The filtering device adopts a DN200 type fully automatic self-cleaning filter.

4. A highway service area water resource comprehensive utilization system according to claim 1, characterized in that: Sludge return pipes are respectively provided between the radial flow type secondary sedimentation tank and the anaerobic tank, and between the radial flow type secondary sedimentation tank and the anoxic tank.

5. The highway service area water resource comprehensive utilization system according to claim 1 is characterized in that: A water reflux pipe is provided from the aerobic pool to the anoxic pool.

6. A method for collecting and treating water resources in a highway service area by using the highway service area water resources comprehensive utilization system according to any one of claims 1 to 5, characterized in that: The following steps are involved: 1) Rainwater from roofs and roads is first intercepted by the drainage device at the initial stage of rainfall. The runoff thickness is set according to the quality of the rainwater. When the intercepted water volume reaches the set value, the drainage ends and the rainwater enters the underground water storage tank; 2) The rainwater is treated by a combination of interception by mechanical grille I, sedimentation in vertical flow sedimentation tank, filtration by filter, and disinfection in disinfection tank I; 3) Sewage pretreatment is to treat domestic and car wash sewage in septic tanks, intercept them with mechanical screen II, and adjust the raw water quantity and quality in sewage regulating tanks. The effluent is lifted by a primary lifting pump and then transported to sewage deep treatment; 4) The sewage deep treatment adopts the process of AAO+MBR combination, including anaerobic tank, anoxic tank, aerobic tank, radial flow secondary sedimentation tank and MBR reaction tank; 5) The effluent from the MBR reaction tank enters the disinfection tank II for disinfection; 6) The effluents from disinfection pool I and disinfection pool II are combined in the clean water pool for reuse and irrigation; 7) The sludge produced by the vertical flow sedimentation tank, radial flow secondary sedimentation tank and MBR reaction tank is regularly discharged and lifted to the sludge pool, and after aerobic digestion, it is regularly transported out by the sanitation department.

7. The method according to claim 6, characterized in that In step 2), the disinfection is carried out by adding chlorine dioxide, and the effective chlorine dosage is 7 mg / L; in step 5), the disinfection is carried out by adding chlorine dioxide, and the effective chlorine dosage is 10 mg / L.

8. The method according to claim 6, characterized in that In step 4), the DO in the anaerobic tank is controlled to be less than 0.2 mg / L, and the anaerobic decomposition is carried out for 1 to 2 hours; a stirring device is provided in the anoxic tank to control the DO to be less than or equal to 0.5 mg / L.

9. The method according to claim 6, characterized in that In step 4), the aerobic tank is a biological treatment device mainly based on the biofilm method and also combined with the activated sludge method. The oxygen source is provided by a rotary blower, and the aerobic microorganisms and autoaerobic bacteria present in the aerobic tank are fully utilized to degrade organic pollutants; the aerobic tank is distributed by perforated pipes.

10. The method according to claim 9, characterized in that The biofilm carrier adopts semi-soft elastic filler.

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