Reclaimed water reuse and rainwater collection and utilization system in expressway service area

Abstract

The invention belongs to the technical field of sewage treatment and comprehensive utilization of water resources, and particularly relates to a reclaimed water reuse and rainwater collection and utilization system in an expressway service area. A sewage treatment, rainwater collection and water-saving irrigation integrated system is constructed, and the MBR process is emphatically applied to treat sewage. The system can effectively remove various pollutants in the sewage, so that the effluent reaches the reclaimed water reuse standard, and the sewage recycling is realized. Meanwhile, rainwater is efficiently collected and utilized, and the water demand of vegetation is accurately met in combination with an intelligent water-saving irrigation technology. The dependence of the service area on fresh water resources is reduced on the whole, the pollution of sewage discharge to the environment is reduced, the water resource management level is improved, remarkable economic, social and environmental benefits are achieved, and an innovative scheme is provided for sustainable utilization of the water resources in the small service area of the expressway.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage treatment and comprehensive utilization of water resources, and in particular provides a middle water reuse and rainwater collection and utilization system for small highway service areas. It mainly adopts the MBR process to treat sewage, and at the same time covers systems such as rainwater collection and water-saving irrigation to achieve efficient recycling of water resources in the service area. Background Art

[0002] With the rapid development of highways, the number of small service areas is increasing continuously. Taking Suizhong Service Area as an example, although its scale is small, the amount of sewage generated daily cannot be underestimated. This sewage comes from washrooms, restaurants, car wash areas, etc., and contains pollutants such as organic matter, grease, heavy metals and microorganisms. When traditional sewage treatment methods are applied in small service areas, there are problems such as large floor area, low treatment efficiency, and difficult-to-meet effluent water quality standards, which cannot meet the requirements of efficient sewage treatment and resource recycling. The discharge of untreated sewage will pollute the surrounding water bodies and soil, and damage the ecological balance. In addition, the water resource management in small service areas faces challenges. How to realize the resource utilization of sewage and relieve the water use pressure has become an urgent problem to be solved. Therefore, it is of great significance to develop a sewage treatment and comprehensive utilization system of water resources suitable for small highway service areas. Summary of the Invention

[0003] The invention aims to provide a comprehensive utilization system and method of water resources for small highway service areas that integrates sewage treatment, rainwater collection and water-saving irrigation. It mainly uses the MBR process to efficiently treat sewage, realizes the resource utilization of sewage, reduces the pollution to the surrounding environment, meets the water use requirements of the service area, reduces the water use cost, and improves the water resource management level of the service area.

[0004] A middle water reuse and rainwater collection and utilization system for highway service areas includes a sewage treatment unit, a rainwater collection unit and a water-saving irrigation unit; the sewage treatment unit includes a grille, a lift pump station, an MBR reactor, a sewage disinfection tank, a middle water storage tank and a middle water reuse pump connected in sequence; the rainwater collection unit includes an initial rainwater runoff diversion device, an underground reservoir, a coagulation sedimentation tank, a filtration tank, a rainwater disinfection tank, a middle water storage tank and a middle water reuse pump connected in sequence; the water-saving irrigation unit includes a micro-sprinkler irrigation system and a drip irrigation system.

[0005] Further, in the above-mentioned middle water reuse and rainwater collection and utilization system for highway service areas, the grille is a planar and inclined mechanical grille, and the gap between the grid bars is determined according to the size of impurities in the sewage.

[0006] Further, in the above-mentioned middle water reuse and rainwater collection and utilization system for highway service areas, the lift pump station adopts a small rectangular reinforced concrete structure, and at least 2 submersible sewage pumps are installed inside.

[0007] Further, for the above-mentioned reclaimed water reuse and rainwater collection and utilization system in highway service areas, the MBR reactor adopts an integrated device with a flat membrane module built therein, and the membrane pore size of the membrane module is below 0.1 micron.

[0008] Further, for the above-mentioned reclaimed water reuse and rainwater collection and utilization system in highway service areas, the sewage disinfection tank and the rainwater disinfection tank adopt chlorine dioxide disinfection and are equipped with chlorine dioxide generators.

[0009] Further, for the above-mentioned reclaimed water reuse and rainwater collection and utilization system in highway service areas, the reclaimed water storage tank adopts a reinforced concrete structure, is subjected to anti-floating treatment, and is equipped with a liquid level control system.

[0010] Further, for the above-mentioned reclaimed water reuse and rainwater collection and utilization system in highway service areas, the coagulant added in the coagulation sedimentation tank is polyaluminum chloride, and the filter tank uses quartz sand as the filter material.

[0011] Further, for the above-mentioned reclaimed water reuse and rainwater collection and utilization system in highway service areas, the irrigation pipe network in the water-saving irrigation unit adopts a layout combining a ring shape and a branch shape according to the vegetation distribution; a filtering device is arranged at the head of the irrigation pipe network.

[0012] The treatment method of the reclaimed water reuse and rainwater collection and utilization system in highway service areas described in any one of the above, characterized by comprising the following steps:

[0013] 1) The sewage generated in the highway service area first enters the grille. After the large particle suspended matters are intercepted by the grille, it is lifted by the lift pump house and the water volume is adjusted to stably enter the MBR reactor.

[0014] 2) In the MBR reactor, microorganisms degrade the organic matters and ammonia nitrogen in the sewage, and the membrane module intercepts microorganisms and suspended matters to realize solid-liquid separation; during the operation of the MBR reactor, the dissolved oxygen, sludge concentration, and pH value in the MBR reactor are regularly monitored, and the aeration volume and sludge discharge volume are adjusted according to the monitoring results to ensure the stable operation of the MBR reactor.

[0015] 3) The effluent of the MBR reactor enters the sewage disinfection tank, and the pathogenic microorganisms in the water are killed by chlorine dioxide disinfection.

[0016] 4) The disinfected reclaimed water enters the reclaimed water storage tank, is stored in the reclaimed water storage tank, and is transported to the water-saving irrigation unit or other water use points in the service area by the reclaimed water reuse pump according to the water use demand; the water quality of the reclaimed water in the reclaimed water storage tank should be regularly detected to ensure that all indicators meet the reclaimed water reuse standard.

[0017] 5) The collected rainwater is first subjected to runoff treatment by the initial rainwater runoff device, then flows into the underground reservoir, and then successively passes through the coagulation sedimentation tank to coagulate and precipitate impurities, the filtration tank to filter residual particles, and the rainwater disinfection tank for chlorine dioxide disinfection treatment. The treated rainwater enters the reclaimed water storage tank, and the reclaimed water is reused for road cleaning, toilet flushing or enters the water-saving irrigation system by the reclaimed water reuse pump;

[0018] 6) The water-saving irrigation unit combines the micro-sprinkler irrigation system and the drip irrigation system according to the water demand characteristics of the vegetation and the soil humidity. The irrigation amount and time are controlled by the control system, and the soil humidity is monitored in real time by the soil humidity sensor. When the humidity is lower than the set value, the irrigation system is started, and when it reaches the appropriate range, the irrigation stops.

[0019] Furthermore, for the above treatment method, the membrane module of the MBR reactor needs to be cleaned regularly. The cleaning is divided into daily maintenance cleaning and chemical cleaning. The daily maintenance cleaning uses clean water for backwashing, and the chemical cleaning uses sodium hypochlorite and citric acid agents. The cleaning frequency is determined according to the membrane fouling situation. Description of the Drawings

[0020] Figure 1 It is a schematic flow diagram of the reclaimed water reuse and rainwater collection and utilization system for highway service areas. Among them, 1. grille, 2. lift pump house, 3. MBR reactor, 4. sewage disinfection tank, 5. initial rainwater runoff device, 6. underground reservoir, 7. coagulation sedimentation tank, 8. filtration tank, 9. rainwater disinfection tank, 10. reclaimed water storage tank, 11. reclaimed water reuse pump, 12. micro-sprinkler irrigation system, 13. drip irrigation system. Detailed Implementation Manner

[0021] Example 1

[0022] A reclaimed water reuse and rainwater collection and utilization system for highway service areas includes a sewage treatment unit, a rainwater collection unit and a water-saving irrigation unit.

[0023] The sewage treatment unit includes a grille 1, a lift pump house 2, an MBR reactor 3, a sewage disinfection tank 4, a reclaimed water storage tank 10 and a reclaimed water reuse pump 11 connected in sequence; the rainwater collection unit includes an initial rainwater runoff device 5, an underground reservoir 6, a coagulation sedimentation tank 7, a filtration tank 8, a rainwater disinfection tank 9, a reclaimed water storage tank 10 and a reclaimed water reuse pump 11 connected in sequence; the water-saving irrigation unit includes a micro-sprinkler irrigation system 12 and a drip irrigation system 13.

[0024] The grille 1 selects a planar, inclined mechanical grille such as the XGS-300 type, and the grid bar gap is determined according to the size of the impurities in the sewage, which is used to intercept large particle suspended solids in the sewage; the lift pump house 2 adopts a small rectangular reinforced concrete structure, and 3 WQR5-10-1.1 type submersible sewage pumps are installed inside, 2 are used and 1 is reserved, which is used to lift sewage and adjust the water volume.

[0025] The MBR reactor 3 adopts the membrane bioreactor technology and selects the integrated ZWM-200 type equipment with a built-in flat membrane module. The membrane pore size of the membrane module is below 0.1 micron. Through biological treatment and membrane separation technology, biological treatment and membrane separation of sewage are carried out to effectively remove pollutants such as organic matter and ammonia nitrogen in the sewage, achieve efficient solid-liquid separation, and ensure the effluent water quality.

[0026] The sewage disinfection tank 4 adopts chlorine dioxide disinfection and is equipped with an HB-1000 type chlorine dioxide generator. Disinfection treatment is carried out according to the treatment water volume and water quality requirements to kill pathogenic microorganisms in the water and ensure the disinfection effect.

[0027] The reclaimed water storage tank 10 adopts a reinforced concrete structure, undergoes anti-floating treatment, and is equipped with a liquid level control system. The reclaimed water reuse pump 11 transports the reclaimed water to water use points such as toilet flushing and greening irrigation in the service area according to the water demand of the water use points.

[0028] The initial rainwater runoff diversion device 5, at the beginning of rainfall, in order to reduce the later treatment cost, diverts and discharges the rainwater with a certain rainfall in the early stage according to the actual situation.

[0029] The capacity of the underground storage tank 6 is designed according to the average annual rainfall and water demand of the service area and is used to collect and store rainwater.

[0030] Coagulating agents such as polyaluminum chloride are added into the coagulation sedimentation tank 7 to cause the impurities in the rainwater to coagulate and precipitate.

[0031] The filtration tank 8 selects quartz sand as the filter material to filter the residual particles and further improve the rainwater quality.

[0032] The rainwater disinfection tank 9 adopts chlorine dioxide disinfection and is equipped with an HB-1000 type chlorine dioxide generator to kill the pathogenic microorganisms in the rainwater.

[0033] The micro-sprinkler irrigation system 12 is used for large-area lawns. Water is sprayed on the plant branches and leaves and the ground through micro-sprinklers for irrigation. The irrigation pipe network adopts a layout combining loop and branch shapes, is equipped with an intelligent control system, monitors parameters such as soil humidity, air temperature, and light through sensors, automatically controls the irrigation volume and time, and realizes precise irrigation. A filtering device is set at the head of the irrigation pipe network to remove impurities and prevent clogging of the drip heads and sprinklers.

[0034] The drip irrigation system 13 is used for vegetation such as flowers and trees that require more precise water demand. Water is slowly, evenly, and quantitatively dripped into the soil near the roots of the plants through drip heads.

[0035] A treatment method based on the reclaimed water reuse and rainwater collection and utilization system of highway service areas:

[0036] 1) Sewage treatment method: In actual operation, the sewage generated in the highway service area enters the grille 1, which intercepts large particles of suspended solids and other debris. The sewage is lifted and adjusted by the lifting pump room 2 and then stably sent to the MBR reactor 3. According to the sewage flow and water quality of the service area, 3 sets of integrated ZWM-200 MBR equipment are selected. In the MBR reactor 3, microorganisms degrade organic matter and ammonia nitrogen in the sewage, and the membrane components intercept microorganisms, suspended solids, etc., to achieve solid-liquid separation, which can ensure that the effluent water quality meets the standard. During operation, the parameters such as dissolved oxygen, sludge concentration, pH value in the MBR reactor 3 are regularly monitored, and the operating parameters such as aeration volume and sludge discharge volume are adjusted in time according to the monitoring results to ensure the stable operation of the MBR reactor 3. The effluent of the MBR reactor 3 enters the sewage disinfection tank 4, and enters the reclaimed water storage tank 10 after the pathogenic microorganisms in the water are disinfected and killed by chlorine dioxide. The reclaimed water stored in the reclaimed water storage tank 10 is transported to the water-saving irrigation unit or other water use points in the service area by the reclaimed water reuse pump 11 according to the water demand. The quality of the reclaimed water in the reclaimed water storage tank 10 should be tested regularly to ensure that all indicators meet the standards for reclaimed water reuse.

[0037] 2) Rainwater treatment method: The roofs of service area buildings, parking lots and roads are the main collection surfaces. After reasonable slope design, rainwater flows into the collection pipe. The rainwater first passes through the initial rainwater discharge device 5 for discharge treatment, and then is collected into the underground water storage tank 6 through the transmission pipe made of corrosion-resistant and high-strength materials, and then enters the coagulation sedimentation tank 7, the filter tank 8 and the rainwater disinfection tank 9 for treatment. The coagulation sedimentation tank 7 adds coagulants such as polyaluminium chloride to condense and precipitate impurities; the filter tank 8 uses quartz sand filter material to filter residual particles; the rainwater disinfection tank 9 uses chlorine dioxide for disinfection to kill pathogenic microorganisms. The treated rainwater enters the reclaimed water storage tank 10, and the reclaimed water is reused by the reclaimed water reuse pump 11 for road cleaning, toilet flushing, etc., or enters the water-saving irrigation system. An intelligent control system is introduced to monitor parameters such as rainwater collection volume in real time and automatically control the operation of related equipment.

[0038] 3) Water-saving irrigation method: The water-saving irrigation system adopts a combination of drip irrigation system 13 and micro-sprinkler irrigation system 12 according to the vegetation distribution and water demand characteristics. The intelligent control system accurately controls the irrigation amount and time according to the sensor data, and monitors the soil moisture in real time through the soil moisture sensor. When the humidity is lower than the set value, the irrigation system is started, and the irrigation is stopped when it reaches the appropriate range. A filtering device is set at the head of the irrigation network to remove impurities and prevent clogging of drippers and sprinklers.

[0039] It is necessary to regularly maintain the equipment of the entire system, check the operation of equipment such as the grille 1, the submersible sewage pump in the lift pump house 2, and the chlorine dioxide generator in the sewage disinfection tank 4, clean up sundries, and check the sealing and wear conditions, etc. Clean the membrane module of the MBR reactor 3 according to regulations. The cleaning is divided into daily maintenance cleaning and chemical cleaning. The daily maintenance cleaning uses reverse flushing with clean water, and the chemical cleaning uses agents such as sodium hypochlorite and citric acid. Determine the cleaning frequency according to the membrane fouling situation.

[0040] During daily operation, continuously optimize the system. By analyzing the long-term accumulated water quality and water volume data, further accurately adjust the process parameters of sewage treatment and rainwater treatment. For example, according to the water quality changes of sewage and rainwater in different seasons and different traffic flows, dynamically adjust the aeration volume of the MBR reactor 3, the dosage of coagulant in the coagulation sedimentation tank 7, etc., to ensure the treatment effect while reducing the operation cost. For the water-saving irrigation unit, deeply study the water demand laws of different vegetation at different growth stages, and combine the real-time monitored soil humidity, meteorological data, etc. to continuously optimize the intelligent irrigation strategy. Introduce machine learning algorithms to analyze historical irrigation data and vegetation growth conditions, predict the optimal irrigation volume and irrigation time under different conditions, and achieve more accurate water resource utilization. Establish a perfect equipment file management system, and detailedly record information such as the purchase time, installation location, maintenance records, and repair history of each piece of equipment. Through regular equipment inspections and data analysis, predict in advance the possible failures of equipment, take preventive maintenance measures, reduce the impact of sudden equipment failures on system operation, and extend the service life of equipment.

Claims

1. A highway service area water reuse and rainwater collection and utilization system, characterized in that: The system comprises a sewage treatment unit, a rainwater collection unit and a water-saving irrigation unit; the sewage treatment unit comprises a grille (1), a lift pump room (2), an MBR reactor (3), a sewage disinfection tank (4), a grey water storage tank (10) and a grey water reuse pump (11) which are connected in sequence; the rainwater collection unit comprises an initial rainwater discarding device (5), an underground water storage tank (6), a coagulation sedimentation tank (7), a filtration tank (8), a rainwater disinfection tank (9), a grey water storage tank (10) and a grey water reuse pump (11) which are connected in sequence; and the water-saving irrigation unit comprises a micro-sprinkler irrigation system (12) and a drip irrigation system (13).

2. A highway service area water reuse and rainwater collection and utilization system according to claim 1, characterized in that: The grille (1) is a flat, tilted mechanical grille, and the gap between the grille bars is determined according to the size of impurities in the sewage.

3. A highway service area water reuse and rainwater collection and utilization system according to claim 1, characterized in that: The lifting pump room (2) adopts a small rectangular reinforced concrete structure, and at least two submersible sewage pumps are installed inside.

4. A highway service area water reuse and rainwater collection and utilization system according to claim 1, characterized in that: The MBR reactor (3) is an integrated device with a built-in flat membrane component, and the membrane pore size of the membrane component is less than 0.1 micrometer.

5. The highway service area water reuse and rainwater collection and utilization system according to claim 1 is characterized in that: The sewage disinfection pool (4) and the rainwater disinfection pool (9) are disinfected using chlorine dioxide and are equipped with a chlorine dioxide generator.

6. A highway service area water reuse and rainwater collection and utilization system according to claim 1, characterized in that: The reclaimed water storage tank (10) adopts a reinforced concrete structure, undergoes anti-floating treatment, and is equipped with a liquid level control system.

7. A highway service area water reuse and rainwater collection and utilization system according to claim 1, characterized in that: The coagulant added into the coagulation sedimentation tank (7) is polyaluminium chloride, and the filter tank (8) uses quartz sand as filter material.

8. The highway service area water reuse and rainwater collection and utilization system according to claim 1 is characterized in that: The irrigation pipe network in the water-saving irrigation unit adopts a layout combining ring and branch shapes according to the distribution of vegetation; a filtering device is arranged at the head of the irrigation pipe network.

9. A method for treating the highway service area water reuse and rainwater collection and utilization system based on any one of claims 1 to 8, characterized in that: The following steps are involved: 1) The sewage generated in the highway service area first enters the screen (1), and after the large suspended solids are intercepted by the screen (1), the water volume is lifted and adjusted by the lifting pump room (2) so that it can stably enter the MBR reactor (3); 2) In the MBR reactor (3), the microorganisms degrade organic matter and ammonia nitrogen in the sewage, and the membrane components intercept the microorganisms and suspended solids to achieve solid-liquid separation; during the operation of the MBR reactor (3), the dissolved oxygen, sludge concentration, and pH value in the MBR reactor (3) are regularly monitored, and the aeration volume and sludge discharge volume are adjusted according to the monitoring results to ensure the stable operation of the MBR reactor (3); 3) The effluent from the MBR reactor (3) enters the sewage disinfection tank (4) and is disinfected with chlorine dioxide to kill pathogenic microorganisms in the water; 4) The disinfected reclaimed water enters the reclaimed water storage tank (10), is stored in the reclaimed water storage tank (10), and is transported to the water-saving irrigation unit or other water use points in the service area by the reclaimed water reuse pump (11) according to the water demand; the water quality of the reclaimed water in the reclaimed water storage tank (10) should be regularly tested to ensure that all indicators meet the reclaimed water reuse standards; 5) The collected rainwater first passes through the initial rainwater discarding device (5) for discarding treatment, then flows into the underground water storage tank (6), and then passes through the coagulation sedimentation tank (7) to condense and precipitate impurities, the filtration tank (8) to filter residual particles, and the rainwater disinfection tank (9) for chlorine dioxide disinfection treatment. The treated rainwater enters the reclaimed water storage tank (10), and the reclaimed water is reused by the reclaimed water reuse pump (11) for road cleaning, toilet flushing or entering the water-saving irrigation system; 6) The water-saving irrigation unit adopts a combination of a micro-sprinkler irrigation system (12) and a drip irrigation system (13) according to the water demand characteristics of the vegetation and the soil moisture. The irrigation amount and time are controlled by a control system, and the soil moisture is monitored in real time by a soil moisture sensor. When the moisture is lower than the set value, the irrigation system is started, and when it reaches an appropriate range, the irrigation is stopped.

10. The processing method according to claim 9, characterized in that: The membrane components of the MBR reactor (3) must be cleaned regularly. The cleaning is divided into daily maintenance cleaning and chemical cleaning. Daily maintenance cleaning uses clean water backwashing, and chemical cleaning uses sodium hypochlorite and citric acid. The cleaning frequency is determined according to the membrane pollution situation.

Images