Sponge city structure and sewage treatment system thereof

Abstract

The invention relates to the technical field of sponge city sewage treatment, and particularly discloses a sponge city structure and a sewage treatment system thereof, the sponge city structure comprises a first diversion area, an overflow treatment area and a permeation area; the overflow treatment area is located between the first flow guide area and the permeation area, the rainwater is guided to the overflow treatment area through the first flow guide area, and the overflow treatment area is used for buffering and purifying the rainwater guided by the first flow guide area; a part of rainwater overflows from the overflow treatment area and flows into the permeation area for auxiliary buffering and purification treatment; through reasonable layout of the first flow guide area, the overflow treatment area and the permeation area, graded flow guide and collaborative purification of rainwater are achieved, buffering treatment of rainwater exceeding the flow guide bearing capacity is guaranteed, auxiliary purification is achieved through the permeation area, and the rainwater treatment efficiency and effect are improved.

Description

Technical Field

[0001] This invention relates to the field of sponge city wastewater treatment technology, and in particular discloses a sponge city structure and its wastewater treatment system. Background Technology

[0002] In the construction of sponge cities, the collection, purification, and resource utilization of rainwater are among the core objectives. Existing sponge city rainwater treatment structures generally suffer from problems such as poor connection of rainwater treatment processes, insufficient purification levels leading to low water quality compliance rates, easy clogging of overflow units with imperfect clogging detection mechanisms, inaccurate linkage control between infiltration zones and treatment institutions, and non-closed-loop logic for the return treatment of substandard rainwater. Some structures also have defects such as inconvenient installation and maintenance of filter components and vague disinfection trigger conditions, making it difficult to achieve efficient purification and stable reuse of rainwater. At the same time, it is also impossible to detect and deal with overflow unit clogging problems in a timely manner, affecting the rainwater regulation capacity and long-term operational stability of the entire sponge city structure. Summary of the Invention

[0003] In order to overcome the shortcomings and deficiencies of the existing technology, the purpose of this invention is to provide a sponge city structure and its sewage treatment system.

[0004] To achieve the above objectives, the present invention provides a sponge city structure, comprising a first diversion zone, an overflow treatment zone, and an infiltration zone; the overflow treatment zone is located between the first diversion zone and the infiltration zone, rainwater is diverted from the first diversion zone to the overflow treatment zone, and the overflow treatment zone is used to buffer and purify the rainwater diverted from the first diversion zone; the rainwater overflowing from the overflow treatment zone flows into the infiltration zone for auxiliary buffering and purification. The overflow treatment area includes a treatment pool, an overflow unit installed on the treatment pool, an overflow outlet connecting pipe connected to the bottom of the treatment pool, and a rainwater treatment mechanism connected to the end of the overflow outlet connecting pipe away from the treatment pool. The overflow unit includes a sludge intercepting basket installed on the treatment pool and an overflow well cover installed on the sludge intercepting basket. The overflow well cover has multiple sets of through channels distributed at equal intervals. After the rainwater flows into the sludge intercepting basket through the through channels, the sludge intercepting basket intercepts impurities in the rainwater and then the rainwater flows into the treatment pool. The rainwater in the treatment pool flows into the rainwater treatment mechanism through the overflow outlet connecting pipe.

[0005] The beneficial effects of this sponge city structure lie in the rational layout of the first diversion zone, overflow treatment zone, and infiltration zone, which achieves graded diversion and coordinated purification of rainwater. This ensures the buffering treatment of rainwater exceeding the diversion capacity and provides auxiliary purification through the infiltration zone, improving the efficiency and effectiveness of rainwater treatment. At the same time, the intercepting basket and overflow manhole cover of the overflow unit can effectively intercept impurities in rainwater, reducing the subsequent treatment load. The structure is simple and easy to maintain. The specific implementation method is as follows: rainwater is first diverted to the overflow treatment zone through the first diversion zone, flows into the intercepting basket through the through channel of the overflow manhole cover to complete the impurity interception, and then flows into the treatment pool for buffering. Rainwater in the treatment pool enters the rainwater treatment mechanism through the overflow outlet connecting pipe, while rainwater exceeding the treatment pool's capacity overflows to the infiltration zone for auxiliary buffering and purification, ultimately achieving the orderly treatment and subsequent resource utilization of rainwater.

[0006] The intercepting basket includes a main body and a snap-fit ​​protrusion on the main body. A first L-shaped step is provided at the connection between the first flow guiding zone and the overflow treatment zone, and a second L-shaped step is provided at the connection between the overflow treatment zone and the infiltration zone. The intercepting basket can be detachably snapped onto the first L-shaped step and the second L-shaped step via the snap-fit ​​protrusion.

[0007] By using the snap-fit ​​boss on the main body in conjunction with the first and second L-shaped steps, the intercepting basket is securely installed at the connection between the diversion zone and the overflow treatment zone, and between the overflow treatment zone and the infiltration zone. This also facilitates the disassembly, cleaning, maintenance, or replacement of the intercepting basket later, preventing the accumulation of impurities from affecting the interception effect and rainwater flow efficiency. The specific implementation method is as follows: a first L-shaped step is set at the connection between the first diversion zone and the overflow treatment zone, and a second L-shaped step is set at the connection between the overflow treatment zone and the infiltration zone. The intercepting basket with the snap-fit ​​boss is assembled and fixed by the snap-fit ​​between the boss and the two L-shaped steps. When rainwater flows through, the intercepting basket intercepts impurities. During subsequent maintenance, the intercepting basket can be directly removed for cleaning, and after cleaning, it can be snapped back into place.

[0008] The main body includes a hollow basket and a graded filter layer disposed within the hollow basket. The graded filter layer includes a coarse-pore filter layer, a medium-pore filter layer, and a fine-pore filter layer. The fine-pore filter layer is disposed between the inner side wall of the hollow basket and the medium-pore filter layer. The medium-pore filter layer is disposed between the fine-pore filter layer and the coarse-pore filter layer. The coarse-pore filter layer is disposed on the side of the medium-pore filter layer away from the fine-pore filter layer. Each filter layer is detachably fixed to the hollow basket through a slot. The graded filter layer is used for the initial filtration of rainwater.

[0009] The beneficial effect of this main structure lies in its graded filtration design, which uses a hollow basket to house three levels of filter layers—coarse, medium, and fine pores—to progressively intercept impurities of different particle sizes in rainwater. This improves the precision of the initial filtration and the efficiency of impurity removal. Furthermore, each filter layer is detachably fixed using slots, facilitating individual disassembly for cleaning and replacement of damaged filters, reducing maintenance costs without affecting the overall filtration function. Specifically, the filter layers are arranged in the hollow basket in a sequence from the outside in: coarse pore filter layer, medium pore filter layer, and fine pore filter layer. The system consists of a tiered filtration system (a fine-pore filter layer attached to the inner wall of the perforated basket, and a mesopore filter layer located between the fine and coarse-pore filter layers), comprising a coarse-pore filter layer (8-12mm pore size), a mesopore filter layer (3-5mm pore size), and a fine-pore filter layer (0.8-1.2mm pore size). Each filter layer is assembled and fixed to the perforated basket via slots. After rainwater flows into the intercepting basket, it passes through the coarse-pore, mesopore, and fine-pore filter layers in sequence to complete the staged filtration, achieving initial purification before flowing into the subsequent treatment structure. During maintenance, the corresponding filter layers can be removed for cleaning or replacement as needed.

[0010] The overflow treatment area also includes a first water level detection component installed in the treatment tank and a water replenishment device installed on the overflow unit. A first drain valve is provided between the overflow outlet connecting pipe and the rainwater treatment mechanism. The first drain valve is used to control the flow of water between the overflow outlet connecting pipe and the rainwater treatment mechanism. The first water level detection component, the first drain valve, and the water replenishment device are all connected to an external control center. When an overflow unit blockage test is performed, after the preset conditions are met, the external control center controls the first drain valve to close. The first water level detection component detects the water level in the treatment tank, and the water replenishment device replenishes the overflow unit with test water according to the water level data in the treatment tank until the water level reaches the preset test value. The device then replenishes the overflow unit with water to the treatment tank that has reached the preset water level test value within a preset time to obtain the first water level data. When the preset time has elapsed since the first water level test and the preset conditions are met, the external control center controls the first drain valve to close again. The first water level detection component detects the water level in the treatment tank. The water replenishment device replenishes the overflow unit with test water according to the water level data in the treatment tank so that the water tank reaches the preset water level test value. The water replenishment device then replenishes the overflow unit with water to the treatment tank that has reached the preset water level test value within a preset time to obtain the second water level data. The external control center presets a water level change difference threshold and completes the blockage determination by comparing the water level data of the two tests.

[0011] This technology establishes a standardized overflow unit blockage testing system by incorporating a water replenishment device, a first water level detection component, and a first drain valve that are linked to an external control center. Under preset conditions, it performs two closed-loop tests: first, the water level in the treatment tank is replenished to a uniform preset test value; then, a second water replenishment is conducted at the same preset time, and water level data is acquired. Finally, blockage is determined based on a preset threshold for the difference in water level changes. This effectively eliminates interference from external factors such as natural rainfall, initial water level differences in the treatment tank, and dynamic water flow, ensuring consistent comparison benchmarks and uniform conditions between the two tests. It also achieves precise and quantitative detection of the overflow unit's blockage status, significantly improving the accuracy and reliability of blockage testing. This allows staff to promptly monitor the overflow unit's operational status, ensuring the stable and efficient operation of the sponge city structure. When a blockage occurs in the overflow unit, the control center alerts staff to replace the interceptor basket.

[0012] The infiltration zone includes a geotextile layer placed on the outer soil layer, a first gravel drainage layer placed on the geotextile layer, a medium sand filter layer placed on the first gravel drainage layer, a planting soil layer placed on the medium sand filter layer, a second gravel drainage layer placed on the planting soil layer, and a lawn / shrub bio-water storage layer placed on the second gravel drainage layer. The particle size of the first gravel drainage layer is smaller than that of the second gravel drainage layer. The first gravel drainage layer extends below the treatment tank and is connected to the rainwater treatment mechanism via a guide section. Rainwater infiltrating through the infiltration zone flows into the rainwater treatment mechanism. The guide section is equipped with an on / off valve for connecting and disconnecting the infiltration zone and the rainwater treatment mechanism. The on / off valve is connected to an external control center and is linked to the first sewage discharge valve for control.

[0013] The composite layered design of "geotextile + multi-stage drainage filter layer + planting soil layer + biological water storage layer" not only achieves efficient rainwater infiltration, auxiliary purification, and peak water storage, but also improves drainage smoothness through the combination of gravel drainage layers with different particle sizes. Furthermore, by leveraging the linkage between the on / off valve and the external control center, as well as the coordinated control with the first sewage valve, the inflow rhythm of rainwater from the infiltration zone to the rainwater treatment facility can be precisely regulated, ensuring the orderly connection of the overall rainwater treatment process and also taking into account the ecological landscape function of the sponge city. The specific implementation method is as follows: On the external soil layer, from top to bottom, a geotextile (using short-fiber needle-punched non-woven geotextile for reverse filtration and anti-clogging), a first gravel drainage layer (particle size 5-10mm), a medium sand filter layer, a planting soil layer, a second gravel drainage layer (particle size 15-20mm), and a lawn / shrub biological water storage layer are laid sequentially. The water layer, in which the first gravel drainage layer extends below the treatment tank and is connected to the rainwater treatment mechanism through a flow guide with an on / off valve, is electrically connected to the external control center and is open by default during normal operation. After overflowing from the overflow treatment area and flowing into the infiltration area, the rainwater is initially intercepted by the lawn and shrub biological water storage layer, guided by the second gravel drainage layer, adsorbed and purified by the planting soil layer, finely filtered by the medium sand filter layer, collected by the first gravel drainage layer, and filtered by the geotextile. The infiltrated rainwater finally gathers at the flow guide and, under the control of the on / off valve (linked with the first sewage valve; if the first sewage valve is open, the on / off valve remains open to ensure that the rainwater flows into the treatment simultaneously; if the first sewage valve is closed for a blockage test, the on / off valve closes simultaneously to avoid interfering with the test), flows into the rainwater treatment mechanism and merges with the rainwater in the overflow treatment area before entering the subsequent treatment stage.

[0014] The rainwater treatment system includes a first treatment unit, a storage tank connected to the first treatment unit, and a second drain valve body located at the connection between the first treatment unit and the storage tank. The first treatment unit includes a first water quality testing mechanism and a water purification device. The second drain valve body, the first water quality testing mechanism, and the water purification device are all electrically connected to an external control center. The first water quality testing mechanism is used to detect the water quality parameters of the rainwater flowing into the first treatment unit in real time and transmit the detection data to the external control center. The external control center adjusts the operating status of the water purification device according to the water quality testing data. When the first water quality testing mechanism detects that the rainwater quality meets the standards, the external control center controls the second drain valve body to open, allowing the purified rainwater to flow into the storage tank for storage and reuse. When the water quality does not meet the standards, the external control center controls the second drain valve body to close and simultaneously adjusts the water purification device to strengthen the purification process.

[0015] Through the coordinated operation of the first treatment unit, the water storage tank, and the second sewage valve, combined with the intelligent linkage between the first water quality testing institution and the external control center, automated regulation and precise water quality control of rainwater purification are achieved. This ensures efficient storage and reuse of compliant rainwater while simultaneously improving the purification effect of substandard rainwater by timely adjusting the operating status of the water purification equipment. It also prevents inferior rainwater from entering the water storage tank and affecting reuse safety. The overall structure features a closed-loop logic and flexible regulation, enhancing the reliability and efficiency of rainwater resource utilization. Specifically, the rainwater treatment system comprises a core treatment system consisting of the first treatment unit (including the first water quality testing institution and water purification equipment), the water storage tank, and the second sewage valve. The second sewage valve, the first water quality testing institution, and the water purification equipment are all electrically connected to the external control center. After the water flows into the first treatment unit, the first water quality testing agency (which can use a multi-parameter water quality sensor, with testing indicators including suspended solids, COD, heavy metal ions, etc.) monitors the rainwater quality parameters in real time and transmits the data to the external control center. The control center analyzes the test data according to preset water quality standards and adjusts the operation of the water purification equipment. When the test data shows that the water quality meets the standards, the external control center sends a command to open the second sewage valve, and the purified rainwater flows smoothly into the storage tank for reuse in scenarios such as greening irrigation and road washing. When the test data shows that the water quality does not meet the standards, the control center immediately closes the second sewage valve and simultaneously adjusts the water purification equipment to strengthen the purification treatment (such as subsequent recirculation, returning the water to the disinfection layer for secondary purification). After the water quality is retested and meets the standards, the second sewage valve is opened again to guide the rainwater into the storage tank.

[0016] The water purification equipment includes a first tank and a return tank connected to the first tank. The first tank is equipped with a sediment adsorption layer and a disinfection layer located below the sediment adsorption layer and connected to the sediment adsorption layer via a first pipe. One end of the disinfection layer is connected to a water storage tank, and the other end is connected to the return tank via a third drain valve. The sediment adsorption layer includes a honeycomb adsorption plate, a modified zeolite filler layer, and an activated carbon fiber layer arranged sequentially from top to bottom. The surface of the honeycomb adsorption plate is provided with several arc-shaped adsorption grooves, which are filled with magnetic adsorption particles for preliminary adsorption of large-diameter sediment particles in rainwater. The modified zeolite filler layer is composed of zeolite particles modified with hydrochloric acid for adsorbing fine sediment and some heavy metal ions in rainwater. The activated carbon fiber layer has a needle-punched felt-like structure for adsorbing residual fine silt and organic pollutants. The silt adsorption layer and the disinfection layer are connected by an inclined guide plate. A first pipe is set at the inclined end of the inclined guide plate. A filter buffer assembly is provided above the first pipe between the silt adsorption layer and the disinfection layer. The filter buffer assembly includes a stainless steel screen, a non-woven filter pad, and a support grid laid from top to bottom. The edge of the filter buffer assembly is sealed to the inner wall of the first tank. The inlet of the first pipe is directly opposite the center of the support grid, and a funnel-shaped buffer cover is provided at the inlet of the first pipe. Rainwater flows into the disinfection layer after secondary filtration treatment through the silt adsorption layer. When the rainwater in the disinfection layer reaches the preset liquid level, the disinfection and filtration treatment is activated.

[0017] The system employs a multi-stage purification and recirculation design, consisting of a sediment adsorption layer, a filter buffer assembly, a disinfection layer, and a return flow tank. Through the synergistic effect of layered adsorption, buffer filtration, and disinfection, it efficiently removes sediment, heavy metal ions, and organic pollutants of varying particle sizes from rainwater, improving purification precision and stability. Simultaneously, the filter buffer assembly prevents impurities from the adsorption layer from directly entering the pipes and causing blockages. The return flow tank provides secondary treatment for substandard rainwater. Liquid level linkage control ensures orderly disinfection. The overall structure is compact and features a closed-loop purification logic. Specifically, the water purification equipment uses a first tank and a return flow tank as its core components. Within the first tank, a sediment adsorption layer, a filter buffer assembly, and a disinfection layer are arranged from top to bottom. The sediment adsorption layer and the disinfection layer are connected via an inclined guide plate and a first pipe. One end of the disinfection layer connects to a water storage tank via a second drain valve, and the other end connects to the return flow tank via a third drain valve. The sediment adsorption layer uses honeycomb-shaped adsorption plates (with magnetically filled arc-shaped adsorption grooves on the surface). The filter buffer assembly is laid in the following order: adsorption particles, modified zeolite packing layer (treated with 5%-10% hydrochloric acid, particle size 2-5mm), activated carbon fiber layer (needle-punched felt). The filter buffer assembly is laid from top to bottom as follows: stainless steel screen (0.5mm aperture), non-woven filter pad, and support grid. The edges are sealed to the inner wall of the tank. The inlet of the first pipe is directly opposite the center of the support grid and is equipped with a funnel-shaped buffer cover. After entering the first tank, rainwater first flows through the silt adsorption layer. Large-diameter silt is adsorbed by magnetic adsorption particles, fine silt and heavy metals are adsorbed by modified zeolite, and residual impurities are adsorbed by activated carbon fiber to complete secondary filtration. After further interception of suspended impurities by the filter buffer assembly, it flows into the disinfection layer through the first pipe along the inclined guide plate. When the liquid level sensor in the disinfection layer detects that the rainwater has reached the preset liquid level, the disinfection filtration process is triggered. After disinfection is completed, it can enter the subsequent water quality testing and discharge stage. If the water quality does not meet the standards, it is discharged into the return tank through the third sewage valve for secondary treatment.

[0018] The disinfection layer includes a disinfection tank, ultraviolet disinfection lamps installed within the tank, a liquid level sensor, and an aeration device. A first water quality testing mechanism is located within the disinfection layer. The aeration device includes an aeration pump, an aeration main pipe extending to the bottom of the disinfection tank, and aeration heads evenly distributed on the aeration main pipe, used to introduce air into the disinfection tank to increase the dissolved oxygen content of the water and enhance the decomposition of pollutants. The ultraviolet disinfection lamps are evenly arranged along the length of the disinfection tank, and each lamp is covered with a quartz protective sleeve to kill microorganisms in the rainwater. Rainwater treated by the sediment adsorption layer and the filter buffer assembly flows into the disinfection tank. The external control center synchronously starts the aeration device and ultraviolet disinfection lamps based on the signal from the liquid level sensor in the disinfection tank. The first water quality testing mechanism monitors the rainwater quality parameters at the outlet of the disinfection tank in real time and transmits the data to the external control center. If the water quality meets the standards, the external control center controls... The second drain valve between the disinfection tank and the storage tank opens, allowing rainwater to flow into the storage tank for storage and reuse. If the water quality fails to meet the standards, the external control center opens the third drain valve between the disinfection tank and the return tank, discharging the substandard rainwater into the return tank for temporary storage. The return tank includes a return reservoir, a second water level detection component installed within the return reservoir, and a return mechanism. When the second water level detection component detects that the water level in the return reservoir reaches a preset value, the external control center simultaneously closes the first drain valve and the on / off valve of the guide section. The return mechanism controls the substandard rainwater in the return tank to flow back to the disinfection layer for secondary purification. Before returning, the residual rainwater in the disinfection layer is drained. The first water quality detection component re-tests the substandard rainwater after secondary purification. The qualified rainwater flows into the storage tank for storage and reuse via the second drain valve, while the unqualified rainwater flows into the external wastewater tank.

[0019] By combining aeration and ultraviolet disinfection, the system achieves a dual enhancement of pollutant decomposition and microbial elimination, improving the thoroughness of rainwater purification. Simultaneously, intelligent linkage between level sensors, water quality testing institutions, and an external control center ensures precise triggering of disinfection and real-time water quality control. Combined with the temporary storage and secondary recirculation purification design of the return tank, the system significantly improves the water quality compliance rate, preventing pollution caused by the direct discharge of substandard rainwater. Furthermore, the pre-recirculation venting and interlocking valve design prevents cross-contamination between new and old rainwater, ensuring stable purification results. The specific implementation method is as follows: The disinfection layer uses a disinfection tank as a carrier, and is equipped with ultraviolet disinfection lamps (evenly arranged along the length of the tank, and externally covered with quartz protective sleeves to prevent pollution), a liquid level sensor, an aeration device (including an aeration pump, an aeration main pipe extending to the bottom of the tank, and evenly distributed aeration heads), and a first water quality testing mechanism (located at the outlet). The return tank consists of a return receiving tank, a second water level detection component, and a return mechanism. The disinfection tank is connected to the storage tank via a second sewage valve and to the return tank via a third sewage valve; after passing through a sediment adsorption layer and a filtration buffer... After being treated by the components, the rainwater flows into the disinfection tank. Based on the level signal from the level sensor, the external control center simultaneously activates the aeration device (introducing air into the tank to increase dissolved oxygen and enhance pollutant decomposition) and the ultraviolet disinfection lamps (killing microorganisms). The first water quality testing agency monitors the water quality parameters at the outlet in real time (such as turbidity, total bacteria count, COD, etc.) and transmits the data to the control center. If the water quality meets the standards, the second drain valve opens, allowing the rainwater to flow into a storage tank for reuse. If the quality does not meet the standards, the third drain valve opens, discharging the rainwater into... The return flow is temporarily stored in the reservoir. When the second water level detection component detects that the water level in the return flow reservoir has reached the preset value, the external control center simultaneously closes the first sewage valve (to block the entry of new rainwater) and the flow guide valve (to avoid interference from rainwater in the infiltration zone). Before the return flow mechanism is started, the residual rainwater in the disinfection layer is drained, and then the substandard rainwater is returned to the disinfection layer for secondary purification. After the secondary purification is completed, the first water quality testing organization tests again. Qualified rainwater flows into the storage tank through the second sewage valve, while substandard rainwater is discharged into the external wastewater tank for subsequent special treatment.

[0020] A wastewater treatment system based on a sponge city structure comprises the following steps: S1. Rainwater is diverted to the overflow treatment area through the first diversion zone. The rainwater flows into the intercepting basket through the overflow manhole cover channel. After primary filtration treatment by the graded filter layer, it flows into the treatment pool. S2. The treatment tank receives and buffers the rainwater after primary filtration. Under normal operating conditions, the first drain valve remains open, and rainwater flows into the rainwater treatment mechanism through the overflow port connection pipe. If the rainwater in the treatment tank exceeds its carrying capacity, the excess rainwater overflows into the infiltration area. During routine blockage testing, the external control center closes the first drain valve and judges the blockage situation by comparing the water level data of the first water level detection component. S3. Rainwater flowing into the infiltration zone undergoes auxiliary purification through multiple media. After purification, it flows into the rainwater treatment mechanism through the guide section with the on / off valve body, where it merges with the rainwater in the overflow treatment area and enters the subsequent deep treatment stage together. S4. The merged rainwater enters the first treatment unit of the rainwater treatment facility, where it is first filtered through the sediment adsorption layer and the filter buffer components, and then flows into the disinfection layer. The external control center simultaneously starts the aeration device and the ultraviolet disinfection lamp, which enhance the synergistic effect of pollutant decomposition and ultraviolet sterilization through aeration and oxygenation, thus completing the deep purification of rainwater. S5. The first water quality testing agency monitors the water quality of the disinfection layer effluent in real time and transmits the data to the external control center; if the water quality meets the standards, the second sewage valve is opened and rainwater flows into the storage tank for storage and reuse; if the water quality does not meet the standards, the second sewage valve is closed and the water is discharged into the return pool for temporary storage. S6. The second water level detection component in the return pool monitors the water level in real time. When the water level reaches the preset value, the external control center controls the first sewage discharge valve and the on / off valve to close. Then the return mechanism starts to return the substandard rainwater in the return pool to the disinfection layer for secondary purification. After purification, the first water quality detection mechanism tests the water quality of the disinfection layer again: the rainwater that passes the retest flows into the water storage tank for storage and reuse, while the rainwater that fails the retest is discharged into the external wastewater tank.

[0021] The system adopts a closed-loop design that integrates "graded flow diversion, step-by-step filtration, deep purification, water quality control, and recirculation re-inspection" to achieve orderly, refined, and intelligent rainwater treatment. It can enhance rainwater carrying capacity through the coordinated diversion of overflow treatment area and infiltration area, and ensure purification effect through the synergistic effect of multi-stage filtration and disinfection. With intelligent linkage control and recirculation re-inspection mechanism, it can significantly improve the water quality compliance rate. At the same time, the routine blockage test function can promptly identify faults and ensure long-term stable operation of the system. Ultimately, it can achieve the dual goals of efficient reuse of rainwater resources and compliant discharge of pollutants.

[0022] S2 also includes S2.1 Once the preset condition of "no rainfall" is met, the external control center sends a control signal to close the first drain valve. The first water level detection component detects the water level in the treatment tank. The water replenishment device replenishes the overflow unit with test water based on the water level data in the treatment tank until the water level reaches the preset test value. Immediately after the external control center starts the timing module, the water replenishment device is started again at the same time. The water replenishment device replenishes water a second time at a constant flow rate of 10L / min. The timing lasts for 5 minutes. After the timing ends, the water replenishment device is turned off, and the first water level detection component detects the first water level data Δh1 in the treatment tank. When the preset condition of "no rainfall" is met and the time since the first water level detection has elapsed to the preset time, the water level in the treatment tank is considered to be at the same level. At this time, the external control center controls the first drain valve to close again, the first water level detection component detects the water level in the treatment tank, and the water replenishment device replenishes the overflow unit with test water according to the water level data in the treatment tank so that the water tank reaches the preset water level test value. The water replenishment device replenishes water a second time at a constant flow rate of 10L / min for 5 minutes. After the timer ends, the water replenishment device is turned off, and the first water level detection component detects the second water level data Δh2 in the treatment tank. The external control center presets the water level change difference threshold ΔH. If the absolute difference between the two water level change data |Δh2-Δh1|≤ΔH, it is determined that the overflow unit is not blocked; if |Δh2-Δh1|>ΔH, it is determined that the overflow unit is blocked.

[0023] The preset value for the first water level test is the same as the preset value for the second water level test. Regardless of the natural water level of the treatment tank during the first test or the natural water level during the second test, the water will be replenished to the same preset value (e.g., 1.0m) through the water replenishment device, and the second water replenishment will be carried out based on this.

[0024] Using a unified preset water level (e.g., 1.0m) as a benchmark, and assuming both tests meet the preset condition of "no rainfall," the first drain valve, the first water level detection component, and the water replenishment device are controlled via an external control center. The initial natural water level of the treatment tank is first replenished to this unified preset value, and then a second water replenishment is performed at a constant flow rate of 10L / min for 5 minutes. Water level rise data Δh1 and Δh2 are obtained for both tests. Finally, the blockage is determined by comparing the absolute difference between the two data points with a preset threshold ΔH. The core of this design is that regardless of the initial natural water level of the treatment tank during the two tests, the water replenishment device replenishes the water to the same preset value, effectively eliminating the interference of initial water level differences on the test results. It also ensures that key parameters such as the water replenishment flow rate and duration are completely consistent between the two tests, with only the unobstructed state of the overflow unit as the variable. This simplifies the judgment logic and significantly improves the accuracy and reliability of the test results, achieving efficient detection of overflow unit blockage.

[0025] The reflux mechanism includes a reflux pump, a reflux main pipe, reflux branch pipes, a reflux control valve, and an empty branch pipe and an empty control valve. The reflux pump is located at the bottom of the reflux receiving tank. One end of the reflux main pipe is connected to the outlet of the reflux pump, and the other end extends to the top of the disinfection tank in the disinfection layer. The reflux branch pipes are evenly distributed at the end of the reflux main pipe, and the outlet of the reflux branch pipe faces the inlet of the disinfection tank, which is used to evenly reflux substandard rainwater into the disinfection tank. The reflux control valve is located on the reflux main pipe and is used to control the opening and closing of the reflux channel.

[0026] One end of the drain branch pipe is connected to the bottom of the disinfection tank, and the other end extends to the external wastewater tank. The drain control valve is installed on the drain branch pipe to control the drainage of residual rainwater in the disinfection tank. When the rainwater still fails to meet the standards after the second re-inspection, the external control center controls the drain control valve to open and drain the wastewater to the wastewater tank through the drain branch pipe.

[0027] The beneficial effects of this invention are as follows: Following the sponge city construction concept of "graded diversion - step-by-step purification - intelligent regulation - return flow guarantee," it constructs a closed-loop rainwater treatment system through the coordinated diversion of the first diversion zone, overflow treatment zone, and infiltration zone. This is combined with graded filtration using intercepting baskets, multi-layer adsorption and disinfection of water purification equipment, and intelligent linkage between various valves and the control center. The significant benefits include efficient rainwater collection, refined purification, and resource reuse, greatly improving water quality compliance rates. Furthermore, the blockage testing mechanism accurately identifies faults, and the detachable design of each component reduces maintenance costs. Simultaneously, the ecological layer design of the infiltration zone balances water storage and peak shaving with landscape functions, effectively preventing rainwater accumulation and pollution discharge, ensuring long-term stable system operation, and comprehensively enhancing the rainwater regulation and resource utilization capabilities of sponge cities. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the overflow treatment area of ​​the present invention; Figure 3 This is a schematic diagram of the overflow unit of the present invention; Figure 4 This is a cross-sectional view of the sludge trap of the present invention; Figure 5 This is a schematic diagram of the rainwater treatment mechanism of the present invention; Figure 6 This is a schematic diagram of the structure of the filter buffer assembly of the present invention; Figure 7 This is a schematic diagram of the structure of the disinfection layer of the present invention; Figure 8 This is a flowchart of the wastewater treatment system of the present invention.

[0029] The reference numerals in the figures include: 1. First diversion zone; 2. Overflow treatment zone; 3. Infiltration zone; 4. Treatment tank; 6. Overflow unit; 7. Overflow outlet connecting pipe; 8. Rainwater treatment mechanism; 9. Sewage interception basket; 11. Overflow manhole cover; 12. Through channel; 13. Main body; 14. Snap-fit ​​boss; 15. First L-shaped step; 16. Second L-shaped step; 17. Hollowed-out basket body; 18. Graded filter layer; 19. Coarse pore filter layer; 21. Medium pore filter layer; 22. Fine pore filter layer; 23. First water level detection component; 24. First sewage valve body; 25. Geotextile; 26. First gravel drainage layer; 27. Medium sand filter layer; 28. Planting soil layer; 29. ​​Second gravel drainage layer; 31. Lawn and shrub biological water storage layer; 32. Diversion section; 33. First treatment unit; 34. Storage 35. Water tank; 36. Second drain valve body; 37. First water quality testing mechanism; 38. Water purification equipment; 39. First tank body; 40. Return tank; 41. Sediment adsorption layer; 42. Disinfection layer; 43. Third drain valve body; 44. Honeycomb adsorption plate; 45. Modified zeolite packing layer; 46. Activated carbon fiber layer; 47. Inclined guide plate; 48. First pipeline; 49. Filter buffer assembly; 51. Stainless steel screen; 52. Non-woven filter pad; 53. Support grid; 54. Disinfection tank; 55. Ultraviolet disinfection lamp; 56. Liquid level sensor; 57. Aeration device; 58. Aeration pump; 59. Aeration main pipe; 61. Aeration head; 100. Return container tank; 200. Second water level detection assembly; 300. Return mechanism; 400. Water replenishment device. Detailed Implementation

[0030] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present invention.

[0031] Please see Figures 1 to 8 As shown, a sponge city structure of the present invention includes a first diversion zone 1, an overflow treatment zone 2, and an infiltration zone 3; the overflow treatment zone 2 is located between the first diversion zone 1 and the infiltration zone 3, and rainwater is diverted to the overflow treatment zone 2 through the first diversion zone 1. The overflow treatment zone 2 is used to buffer and purify the rainwater diverted through the first diversion zone 1. The rainwater overflowing from the overflow treatment zone 2 flows into the infiltration zone 3 for auxiliary buffering and purification. The overflow treatment area 2 includes a treatment pool 4, an overflow unit 6 installed on the treatment pool 4, an overflow outlet connecting pipe 7 connected to the bottom of the treatment pool 4, and a rainwater treatment mechanism 8 connected to the end of the overflow outlet connecting pipe 7 away from the treatment pool 4. The overflow unit 6 includes a sludge intercepting basket 9 installed on the treatment pool 4 and an overflow well cover 11 covering the sludge intercepting basket 9. The overflow well cover 11 has multiple sets of through grooves 12 distributed at equal intervals. After the rainwater flows into the sludge intercepting basket 9 through the through grooves 12, the sludge intercepting basket 9 intercepts the impurities in the rainwater and the rainwater flows into the treatment pool 4. The rainwater in the treatment pool 4 flows into the rainwater treatment mechanism 8 through the overflow outlet connecting pipe 7.

[0032] The beneficial effects of this sponge city structure lie in the rational layout of the first diversion zone 1, the overflow treatment zone 2, and the infiltration zone 3, which achieves graded diversion and coordinated purification of rainwater. This ensures the buffering treatment of rainwater exceeding the diversion capacity, while the infiltration zone 3 provides auxiliary purification, improving the efficiency and effectiveness of rainwater treatment. At the same time, the intercepting basket 9 of the overflow unit 6, in conjunction with the overflow manhole cover 11, can effectively intercept impurities in the rainwater, reducing the subsequent treatment load. The structure is simple and easy to maintain. The specific implementation method is as follows: rainwater is first diverted to the overflow treatment zone 2 through the first diversion zone 1, and then flows into the intercepting basket 9 through the through channel 12 of the overflow manhole cover 11 to complete the impurity interception. It then flows into the treatment pool 4 for buffering. Rainwater in the treatment pool 4 enters the rainwater treatment mechanism 8 through the overflow outlet connecting pipe 7. Rainwater exceeding the carrying capacity of the treatment pool 4 overflows to the infiltration zone 3 for auxiliary buffering and purification, ultimately achieving the orderly treatment and subsequent resource utilization of rainwater.

[0033] The intercepting basket 9 includes a main body 13 and a snap-fit ​​protrusion 14 disposed on the main body 13. A first L-shaped step 15 is provided at the connection between the first flow guiding zone 1 and the overflow treatment zone 2, and a second L-shaped step 16 is provided at the connection between the overflow treatment zone 2 and the infiltration zone 3. The intercepting basket 9 is detachably snapped onto the first L-shaped step 15 and the second L-shaped step 16 via the snap-fit ​​protrusion 14.

[0034] By cooperating with the snap-fit ​​boss 14 of the main body 13 and the first and second L-shaped steps 16, the intercepting basket 9 is stably installed at the connection between the diversion zone and the overflow treatment zone 2, and between the overflow treatment zone 2 and the infiltration zone 3. This also facilitates the disassembly, cleaning, maintenance, or replacement of the intercepting basket 9 in the future, avoiding the impact of impurity accumulation on the interception effect and rainwater flow efficiency. The specific implementation method is as follows: a first L-shaped step 15 is set at the connection between the first diversion zone 1 and the overflow treatment zone 2, and a second L-shaped step 16 is set at the connection between the overflow treatment zone 2 and the infiltration zone 3. The intercepting basket 9 with the snap-fit ​​boss 14 is assembled and fixed by the snap-fit ​​between the boss and the two L-shaped steps. When rainwater flows through, the intercepting basket 9 intercepts impurities. During subsequent maintenance, the intercepting basket 9 can be directly removed for cleaning. After cleaning, it can be re-snap and reset.

[0035] The main body 13 includes a hollow basket 17 and a graded filter layer 18 disposed within the hollow basket 17. The graded filter layer 18 includes a coarse-pore filter layer 19, a medium-pore filter layer 21, and a fine-pore filter layer 22. The fine-pore filter layer 22 is disposed between the inner wall of the hollow basket 17 and the medium-pore filter layer 21. The medium-pore filter layer 21 is disposed between the fine-pore filter layer 22 and the coarse-pore filter layer 19. The coarse-pore filter layer 19 is disposed on the side of the medium-pore filter layer 21 away from the fine-pore filter layer 22. Each filter layer is detachably fixed within the hollow basket 17 via a slot. The graded filter layer 18 is used for the initial filtration of rainwater.

[0036] The beneficial effect of the main body 13 structure lies in the graded filtration design of the three-stage filter layer (coarse pore, medium pore, and fine pore) mounted on the hollow basket 17. This design can progressively intercept impurities of different particle sizes in rainwater, improving the fineness of the initial filtration and the efficiency of impurity removal. Simultaneously, each filter layer is detachably fixed using a slotted method, facilitating individual disassembly, cleaning, and replacement of damaged filters, reducing maintenance costs without affecting the overall filtration function. Specifically, the graded filtration is arranged within the hollow basket 17 in the following order from the outside in: coarse pore filter layer 19, medium pore filter layer 21, and fine pore filter layer 22. Layer 18 (fine pore filter layer 22 is close to the inner wall of the hollow basket 17, and medium pore filter layer 21 is located between the fine pore and coarse pore filter layers 19), coarse pore filter layer 19 (pore diameter 8-12mm), medium pore filter layer 21 (pore diameter 3-5mm), fine pore filter layer 22 (pore diameter 0.8-1.2mm); each filter layer is assembled and fixed to the hollow basket 17 through slots. After rainwater flows into the intercepting basket 9, it passes through the coarse pore, medium pore and fine pore filter layers 22 in sequence to complete the step-by-step filtration, so that it flows into the subsequent treatment structure after the initial purification. During maintenance, the corresponding filter layer can be removed for cleaning or replacement as needed.

[0037] The overflow treatment area 2 also includes a first water level detection component 23 installed in the treatment tank 4 and a water replenishment device 400 installed on the overflow unit 6. A first drain valve body 24 is provided between the overflow outlet connecting pipe 7 and the rainwater treatment mechanism 8. The first drain valve body 24 is used to realize the flow of water between the overflow outlet connecting pipe 7 and the rainwater treatment mechanism 8. The first water level detection component 23, the first drain valve body 24 and the water replenishment device 400 are all connected to an external control center. When the overflow unit 6 is tested for blockage, after the preset conditions are met, the external control center controls the first drain valve body 24 to close. The first water level detection component 23 detects the water level in the treatment tank 4, and the water replenishment device 400 replenishes the overflow unit 6 with test water according to the water level data in the treatment tank 4 so that the water tank reaches the test water level. The water replenishment device 400 replenishes the overflow unit 6 with water to the treatment tank 4 that has reached the preset water level test value within a preset time to obtain the first water level data. When the preset time has elapsed since the first water level test and the preset conditions are met, the external control center controls the first drain valve 24 to close again, and the first water level detection component 23 detects the water level in the treatment tank 4. The water replenishment device 400 replenishes the overflow unit 6 with test water according to the water level data in the treatment tank 4 so that the water tank reaches the preset water level test value. The water replenishment device 400 then replenishes the overflow unit 6 with water to the treatment tank 4 that has reached the preset water level test value within a preset time to obtain the second water level data. The external control center presets a water level change difference threshold and completes the blockage determination by comparing the water level data of the two tests.

[0038] This technology constructs a standardized overflow unit 6 blockage testing system by setting up a water replenishment device 400, a first water level detection component 23, and a first sewage discharge valve body 24 that are linked to an external control center. Under preset conditions, through two closed-loop testing processes, the water level in the treatment tank 4 is first replenished to a uniform preset test value, and then replenished a second time for the same preset period to obtain water level data. Finally, blockage is determined based on a preset water level change difference threshold. This effectively eliminates interference from external factors such as natural rainfall, initial water level differences in the treatment tank 4, and dynamic water flow on the test results, ensuring consistent comparison benchmarks and unified conditions between the two tests. It also achieves precise and quantitative detection of the blockage status of the overflow unit 6, significantly improving the accuracy and reliability of blockage testing. This allows staff to promptly grasp the operating status of the overflow unit 6, ensuring the stable and efficient operation of the sponge city structure. When the overflow unit 6 becomes blocked, the control center reminds staff to replace the intercepting basket 9.

[0039] The infiltration zone 3 includes a geotextile 25 placed on the external soil layer, a first gravel drainage layer 26 placed on the geotextile 25, a medium sand filter layer 27 placed on the first gravel drainage layer 26, a planting soil layer 28 placed on the medium sand filter layer 27, a second gravel drainage layer 29 placed on the planting soil layer 28, and a lawn and shrub biological water storage layer 31 placed on the second gravel drainage layer 29. The particle size of the first gravel drainage layer 26 is smaller than that of the second gravel drainage layer 29. The first gravel drainage layer 26 extends below the treatment tank 4 and is connected to the rainwater treatment mechanism 8 via a guide section 32. Rainwater infiltrating through the infiltration zone 3 flows into the rainwater treatment mechanism 8. The guide section 32 is equipped with a shut-off valve for switching the infiltration zone 3 and the rainwater treatment mechanism 8 on and off. The shut-off valve is connected to an external control center and is linked to the first sewage valve 24 for control.

[0040] The composite layered design of "geotextile 25 + multi-stage drainage filter layer + planting soil layer 28 + biological water storage layer" not only achieves efficient rainwater infiltration, auxiliary purification, and peak water storage, but also improves drainage smoothness through the combination of gravel drainage layers with different particle sizes. Simultaneously, by leveraging the linkage between the on / off valve and the external control center, as well as the coordinated control with the first sewage valve 24, the inflow rhythm of rainwater from the infiltration zone 3 to the rainwater treatment unit 8 can be precisely regulated, ensuring the orderly connection of the overall rainwater treatment process and also taking into account the ecological landscape function of the sponge city. The specific implementation method is as follows: Geotextile 25 (using short-fiber needle-punched non-woven geotextile 25 for reverse filtration and anti-clogging), the first gravel drainage layer 26 (particle size 5-10mm), the medium sand filter layer 27, the planting soil layer 28, the second gravel drainage layer 29 (particle size 15-20mm), and the lawn / shrub biological water storage layer 31 are laid sequentially from top to bottom on the external soil layer. The first gravel drainage layer 26 extends below the treatment tank 4 and is connected to the rainwater treatment mechanism 8 through the flow guide 32 with an on / off valve. The on / off valve is electrically connected to the external control center and is open by default during normal operation. After overflowing from the overflow treatment area 2 into the infiltration area 3, the rainwater is initially intercepted by the lawn and shrub biological water storage layer 31, guided by the second gravel drainage layer 29, adsorbed and purified by the planting soil layer 28, finely filtered by the medium sand filter layer 27, collected by the first gravel drainage layer 26, and back filtered by the geotextile 25. The infiltrated rainwater finally gathers at the flow guide 32 and flows into the rainwater treatment mechanism 8 under the control of the on / off valve (linked with the first sewage valve 24; if the first sewage valve 24 is open, the on / off valve remains open to ensure that the rainwater flows into the treatment simultaneously; when the first sewage valve 24 is closed for a blockage test, the on / off valve closes simultaneously to avoid interfering with the test). After merging with the rainwater in the overflow treatment area 2, it enters the subsequent treatment stage.

[0041] The rainwater treatment mechanism 8 includes a first treatment unit 33, a water storage tank 34 connected to the first treatment unit 33, and a second drain valve 35 located at the connection between the first treatment unit 33 and the water storage tank 34. The first treatment unit 33 includes a first water quality testing mechanism 36 and a water purification device 37. The second drain valve 35, the first water quality testing mechanism 36, and the water purification device 37 are all electrically connected to an external control center. The first water quality testing mechanism 36 is used to detect the rainwater quality parameters flowing into the first treatment unit 33 in real time and transmit the detection data to the external control center. The external control center adjusts the operating status of the water purification device 37 according to the water quality testing data. When the first water quality testing mechanism 36 detects that the rainwater quality meets the standards, the external control center controls the second drain valve 35 to open, allowing the purified rainwater to flow into the water storage tank 34 for storage and reuse. When the water quality does not meet the standards, the external control center controls the second drain valve 35 to close and simultaneously adjusts the water purification device 37 to strengthen the purification treatment.

[0042] Through the coordinated operation of the first treatment unit 33, the water storage tank 34, and the second sewage valve 35, combined with the intelligent linkage between the first water quality testing institution 36 and the external control center, automated regulation and precise water quality control of rainwater purification treatment are achieved. This ensures efficient storage and reuse of compliant rainwater, while also improving the purification effect of non-compliant rainwater by timely adjusting the operating status of the water purification equipment 37. This prevents inferior rainwater from entering the water storage tank 34 and affecting reuse safety. The overall structure is logically closed-loop and flexible in regulation, improving the reliability and efficiency of rainwater resource utilization. Specifically, the rainwater treatment institution 8 constructs a core treatment system consisting of the first treatment unit 33 (including the first water quality testing institution 36 and the water purification equipment 37), the water storage tank 34, and the second sewage valve 35. The second sewage valve 35, the first water quality testing institution 36, and the water purification equipment 37 are all electrically connected to the external control center. Connection; After rainwater flows into the first treatment unit 33, the first water quality testing institution 36 (which may use a multi-parameter water quality sensor, with testing indicators including suspended solids, COD, heavy metal ions, etc.) monitors the rainwater quality parameters in real time and transmits the data to the external control center. The control center analyzes the test data according to the preset water quality standards and adjusts the operation of the water purification equipment 37. When the test data shows that the water quality meets the standards, the external control center sends a command to open the second sewage valve 35, and the purified rainwater flows smoothly into the storage tank 34 for storage and reuse in scenarios such as greening irrigation and road washing. When the test data shows that the water quality does not meet the standards, the control center immediately controls the second sewage valve 35 to close and simultaneously adjusts the water purification equipment 37 to strengthen the purification treatment (such as subsequent recirculation, recirculating to the disinfection layer 42 for secondary purification). After the water quality is retested and meets the standards, the second sewage valve 35 is opened again to guide the rainwater into the storage tank 34.

[0043] The water purification equipment 37 includes a first pool 38 and a return pool 39 connected to the first pool 38. The first pool 38 is provided with a sediment adsorption layer 41 and a disinfection layer 42 located below the sediment adsorption layer 41 and connected to the sediment adsorption layer 41 via a first pipe 48. One end of the disinfection layer 42 is connected to a water storage tank 34, and the other end is connected to the return pool 39 via a third drain valve body 43. The sediment adsorption layer 41 includes a honeycomb adsorption plate 44, a modified zeolite filler layer 45, and an activated carbon fiber layer 46 arranged sequentially from top to bottom. The surface of the honeycomb adsorption plate 44 is provided with several arc-shaped adsorption grooves, which are filled with magnetic adsorption particles for preliminary adsorption of large-diameter sediment particles in rainwater. The modified zeolite filler layer 45 is composed of zeolite particles modified by hydrochloric acid and is used to adsorb fine sediment and some heavy metal ions in rainwater. The activated carbon fiber layer 46 has a needle-punched felt structure for adsorbing residual fine silt and organic pollutants. The silt adsorption layer 41 and the disinfection layer 42 are connected by an inclined guide plate 47. The first pipe 48 is located at the inclined end of the inclined guide plate 47. A filter buffer assembly 49 is provided above the first pipe 48 between the silt adsorption layer 41 and the disinfection layer 42. The filter buffer assembly 49 includes a stainless steel screen 51, a non-woven filter pad 52, and a support grid 53 laid from top to bottom. The edge of the filter buffer assembly 49 is sealed and fitted to the inner wall of the first pool body 38. The inlet of the first pipe 48 is directly opposite the center of the support grid 53, and a funnel-shaped buffer cover is provided at the inlet of the first pipe 48. Rainwater flows into the disinfection layer 42 after secondary filtration treatment through the silt adsorption layer 41. When the rainwater in the disinfection layer 42 reaches the preset liquid level, the disinfection and filtration treatment is activated.

[0044] Employing a multi-stage purification and recirculation design consisting of a "sediment adsorption layer 41 + filter buffer component 49 + disinfection layer 42 + return tank 39," this system effectively removes sediment, heavy metal ions, and organic pollutants of varying particle sizes from rainwater through the synergistic effects of layered adsorption, buffer filtration, and disinfection. This enhances purification precision and stability. Simultaneously, the filter buffer component 49 prevents impurities from the adsorption layer from directly entering the pipes and causing blockages. The return tank 39 provides secondary treatment for substandard rainwater, and the liquid level linkage control ensures the orderly implementation of disinfection. The overall structure is compact. The purification logic is closed-loop; its specific implementation is as follows: the water purification equipment 37 takes the first pool 38 and the return pool 39 as the core carriers. In the first pool 38, a sediment adsorption layer 41, a filter buffer component 49 and a disinfection layer 42 are set from top to bottom. The sediment adsorption layer 41 and the disinfection layer 42 are connected through the inclined guide plate 47 and the first pipe 48. One end of the disinfection layer 42 is connected to the water storage tank 34 through the second sewage valve body 35, and the other end is connected to the return pool 39 through the third sewage valve body 43; wherein the sediment adsorption layer 41 is arranged in a honeycomb adsorption plate 44 (with an arc-shaped surface adsorption). The filter buffer assembly 49 is laid in the following order: magnetic adsorption particles (filled in the trough), modified zeolite packing layer 45 (treated with 5%-10% hydrochloric acid, particle size 2-5mm), and activated carbon fiber layer 46 (needle-punched felt). From top to bottom, the assembly consists of a stainless steel screen 51 (0.5mm aperture), a non-woven filter pad 52, and a support grid 53, with the edges sealed to the inner wall of the tank. The inlet of the first pipe 48 is directly opposite the center of the support grid 53 and is equipped with a funnel-shaped buffer cover. After entering the first tank 38, rainwater first flows through the sediment adsorption layer 41, and then... The process involves two stages: magnetic adsorption particles adsorb large-diameter silt, modified zeolite adsorbs fine silt and heavy metals, and activated carbon fiber adsorbs residual impurities. After secondary filtration, the water flows through the first pipe 48 along the inclined guide plate 47 to the disinfection layer 42, where the suspended impurities are further intercepted by the filter buffer component 49. When the liquid level sensor 56 in the disinfection layer 42 detects that the rainwater has reached the preset level, the disinfection and filtration process is triggered. After disinfection is completed, the water can proceed to the subsequent water quality testing and discharge stage. If the water quality does not meet the standards, it is discharged into the return pool 39 through the third drain valve 43 for secondary treatment.

[0045] The disinfection layer 42 includes a disinfection tank 54, ultraviolet disinfection lamps 55 installed in the disinfection tank 54, a liquid level sensor 56, and an aeration device 57. A first water quality testing mechanism 36 is installed in the disinfection layer 42. The aeration device 57 includes an aeration pump 58, an aeration main pipe 59 extending to the bottom of the disinfection tank 54, and aeration heads 61 evenly distributed on the aeration main pipe 59, used to introduce air into the disinfection tank 54 to increase the dissolved oxygen content of the water and enhance the decomposition of pollutants. The ultraviolet disinfection lamps 55 are evenly arranged along the length of the disinfection tank 54, and the ultraviolet disinfection lamps 55 are covered with quartz protective sleeves to kill microorganisms in rainwater. Rainwater treated by the sediment adsorption layer 41 and the filter buffer assembly 49 flows into the disinfection tank 54. The external control center synchronously starts the aeration device 57 and the ultraviolet disinfection lamps 55 according to the signal from the liquid level sensor 56 in the disinfection tank 54. The first water quality testing mechanism 36 monitors the rainwater quality parameters at the outlet of the disinfection tank 54 in real time and transmits the data to the external control center. If the water quality meets the standards, the external control center controls the system to... The second drain valve 35 between the disinfection tank 54 and the water storage tank 34 is opened, allowing rainwater to flow into the water storage tank 34 for storage and reuse. If the water quality fails to meet the standards, the external control center controls the third drain valve 43 between the disinfection tank 54 and the return tank 39 to open, discharging the substandard rainwater into the return tank 39 for temporary storage. The return tank 39 includes a return receiving tank 100, a second water level detection component 200 installed in the return receiving tank 100, and a return mechanism 300. When the second water level detection component 200 detects water level in the return receiving tank 100... When the water level reaches the preset value, the external control center simultaneously closes the on / off valves of the first sewage valve body 24 and the guide section 32. The return mechanism 300 controls the non-compliant rainwater in the return pool 39 to return to the disinfection layer 42 for secondary purification treatment. Before returning, the residual rainwater in the disinfection layer 42 is emptied. The first water quality testing agency 36 retests the non-compliant rainwater after secondary purification treatment. The qualified rainwater flows into the water storage tank 34 for storage and reuse through the second sewage valve body 35. The unqualified rainwater flows into the external wastewater pool.

[0046] Through the synergistic effect of aeration and ultraviolet disinfection, the decomposition of pollutants and the killing of microorganisms are enhanced, improving the thoroughness of rainwater purification. Simultaneously, the intelligent linkage between the liquid level sensor 56, the water quality testing agency, and the external control center ensures precise triggering of disinfection and real-time control of water quality. Combined with the temporary storage and secondary return purification design of the return tank 39, the water quality compliance rate is significantly improved, preventing pollution caused by the direct discharge of substandard rainwater. Furthermore, the pre-return venting and linked valve closing design prevents cross-contamination between new and old rainwater, ensuring stable purification effects. The specific implementation method is as follows: the disinfection layer 42 is connected to the disinfection tank 5... The 4 serves as the carrier, internally equipped with ultraviolet disinfection lamps 55 (uniformly arranged along the length of the pool body, externally covered with quartz protective sleeves to prevent pollution), a liquid level sensor 56, an aeration device 57 (including an aeration pump 58, an aeration main pipe 59 extending to the bottom of the pool, and uniformly distributed aeration heads 61), and a first water quality testing mechanism 36 (located at the outlet). The return pool 39 consists of a return receiving pool 100, a second water level detection component 200, and a return mechanism 300. The disinfection pool 54 is connected to the storage pool 34 via the second drain valve body 35 and to the return pool 39 via the third drain valve body 43; it passes through a sediment adsorption layer 41 and a filter buffer. After being treated by component 49, the rainwater flows into disinfection tank 54. Based on the level signal from level sensor 56, the external control center simultaneously activates aeration device 57 (to introduce air into the tank to increase dissolved oxygen and enhance pollutant decomposition) and ultraviolet disinfection lamp 55 (to kill microorganisms). The first water quality testing agency 36 monitors the water quality parameters at the outlet in real time (such as turbidity, total bacteria count, COD, etc.) and transmits them to the control center. If the water quality meets the standards, the second drain valve 35 is opened, and the rainwater flows into storage tank 34 for storage and reuse. If the water quality does not meet the standards, the third drain valve 43 is opened, and the rainwater is discharged into the return container. Pool 100 temporarily stores the water. When the second water level detection component 200 detects that the water level in the return pool 39 has reached the preset value, the external control center simultaneously closes the first sewage valve 24 (to block new rainwater from entering) and the flow guide 32 on / off valve (to avoid rainwater interference in the infiltration zone 3). Before starting the return mechanism 300, the residual rainwater in the disinfection layer 42 is drained, and then the substandard rainwater is returned to the disinfection layer 42 for secondary purification. After the secondary purification is completed, the first water quality detection component 36 tests again. Qualified rainwater flows into the storage pool 34 through the second sewage valve 35, while substandard rainwater is discharged into the external wastewater pool for subsequent special treatment.

[0047] A wastewater treatment system based on a sponge city structure comprises the following steps: S1. Rainwater is diverted to overflow treatment area 2 through the first diversion zone 1. The rainwater flows into intercepting basket 9 through the overflow manhole cover 11 channel. After primary filtration treatment by the graded filter layer 18, it flows into treatment pool 4. S2. Treatment tank 4 receives and buffers rainwater after primary filtration. Under normal operating conditions, the first drain valve 24 remains open, and rainwater flows into the rainwater treatment mechanism 8 through the overflow port connection pipe 7. If the rainwater in treatment tank 4 exceeds its carrying capacity, the excess rainwater overflows into the infiltration zone 3. During a routine blockage test, the external control center closes the first drain valve 24 and judges the blockage situation by comparing the water level data of the first water level detection component 23. S3. The rainwater flowing into the infiltration zone 3 undergoes auxiliary purification through multiple media. After purification, it flows into the rainwater treatment mechanism 8 through the guide section 32 with the on / off valve body, merges with the rainwater in the overflow treatment zone 2, and enters the subsequent deep treatment stage together. S4. The merged rainwater enters the first treatment unit 33 of the rainwater treatment unit 8, and is first filtered through the sediment adsorption layer 41 and the filter buffer component 49 in sequence, and then flows into the disinfection layer 42; the external control center simultaneously starts the aeration device 57 and the ultraviolet disinfection lamp 55, and enhances the synergistic effect of pollutant decomposition and ultraviolet sterilization through aeration and oxygenation, so as to complete the deep purification of rainwater. S5. The first water quality testing agency 36 monitors the water quality of the effluent from the disinfection layer 42 in real time and transmits the data to the external control center; if the water quality meets the standard, the second sewage valve 35 is opened and the rainwater flows into the storage tank 34 for storage and reuse; if the water quality does not meet the standard, the second sewage valve 35 is closed and the water is discharged into the return tank 39 for temporary storage. S6. The second water level detection component 200 in the return pool 39 monitors the water level in real time. When the water level reaches the preset value, the external control center controls the first sewage valve body 24 and the on / off valve body to close. Then the return mechanism 300 starts to return the substandard rainwater in the return pool 39 to the disinfection layer 42 for secondary purification treatment. After purification, the first water quality detection mechanism 36 tests the water quality of the disinfection layer 42 again: the rainwater that passes the retest flows into the water storage tank 34 for storage and reuse, and the rainwater that fails the retest is discharged into the external wastewater tank.

[0048] The system adopts a closed-loop design that integrates "graded flow diversion, step-by-step filtration, deep purification, water quality control, and recirculation re-inspection" to achieve orderly, refined, and intelligent rainwater treatment. It can enhance rainwater carrying capacity through the coordinated diversion of overflow treatment zone 2 and infiltration zone 3, and ensure purification effect through the synergistic effect of multi-stage filtration and disinfection. With the intelligent linkage control and recirculation re-inspection mechanism, the water quality compliance rate is greatly improved. At the same time, the routine blockage test function can promptly identify faults and ensure the long-term stable operation of the system. Ultimately, it achieves the dual goals of efficient reuse of rainwater resources and compliant discharge of pollutants.

[0049] S2 also includes S2.1 When the preset condition of "no rainfall" is met, the external control center sends a control signal to close the first drain valve 24. The first water level detection component 23 detects the water level in the treatment tank 4. The water replenishment device 400 replenishes the overflow unit 6 with test water according to the water level data in the treatment tank 4 until the water level reaches the preset test value. Then, the external control center immediately starts the timing module. At the same time as the timing starts, the water replenishment device 400 is started again. The water replenishment device 400 replenishes water a second time at a constant flow rate of 10L / min. The timing lasts for 5 minutes. After the timing ends, the water replenishment device 400 is turned off. The first water level detection component 23 detects the first water level data Δh1 in the treatment tank 4. When the preset condition of "no rainfall" is met and the time since the first water level detection has reached the preset time, the water level in the treatment tank 4 is considered to be at the same level. At this time, the external control center controls the first drain valve 24 to close again, the first water level detection component 23 detects the water level in the treatment tank 4, and the water replenishment device 400 replenishes test water to the overflow unit 6 according to the water level data in the treatment tank 4 so that the water tank reaches the preset water level test value. The water replenishment device 400 replenishes water for the second time at a constant flow rate of 10L / min, and the timer lasts for 5 minutes. After the timer ends, the water replenishment device 400 is turned off, and the first water level detection component 23 detects the second water level data Δh2 in the treatment tank 4. The external control center presets the water level change difference threshold ΔH. If the absolute difference between the two water level change data |Δh2-Δh1|≤ΔH, it is determined that the overflow unit 6 is not blocked; if |Δh2-Δh1|>ΔH, it is determined that the overflow unit 6 is blocked.

[0050] The preset value for the first water level test is the same as the preset value for the second water level test. Regardless of the natural water level of treatment tank 4 during the first test or the natural water level during the second test, the water will be replenished to the same preset value (e.g., 1.0m) through the water replenishment device 400, and the second water replenishment will be carried out based on this.

[0051] Using a unified preset water level (e.g., 1.0m) as a benchmark, and assuming both tests meet the preset condition of "no rainfall," the first drain valve 24, the first water level detection component 23, and the water replenishment device 400 are controlled by an external control center. The initial natural water level of the treatment tank 4 is first replenished to this unified preset value, and then a second water replenishment is performed for 5 minutes at a constant flow rate of 10L / min. Water level rise data Δh1 and Δh2 are obtained for both tests. Finally, the blockage is determined by comparing the absolute difference between the two data points with the preset threshold ΔH. The core of this design is that regardless of the initial natural water level of the treatment tank 4 during the two tests, the water replenishment device 400 replenishes the water to the same preset value, effectively eliminating the interference of initial water level differences on the test results. Simultaneously, it ensures that key parameters such as the water replenishment flow rate and duration are completely consistent between the two tests, with only the unobstructed state of the overflow unit 6 as a variable. This simplifies the judgment logic and significantly improves the accuracy and reliability of the test results, achieving efficient detection of the blockage state of the overflow unit 6.

[0052] The reflux mechanism 300 includes a reflux pump, a reflux main pipe, reflux branch pipes, a reflux control valve, and an empty branch pipe and an empty control valve. The reflux pump is located at the bottom of the reflux receiving tank 100. One end of the reflux main pipe is connected to the outlet of the reflux pump, and the other end extends to the disinfection tank 54 above the disinfection layer 42. The reflux branch pipes are evenly distributed at the end of the reflux main pipe, and the outlet of the reflux branch pipe faces the inlet of the disinfection tank 54, for uniformly refluxing substandard rainwater into the disinfection tank 54. The reflux control valve is located on the reflux main pipe and is used to control the opening and closing of the reflux channel.

[0053] One end of the drain branch pipe is connected to the bottom of the disinfection tank 54, and the other end extends to the external wastewater tank. The drain control valve is installed on the drain branch pipe to control the drainage of residual rainwater in the disinfection tank 54. When the rainwater still fails to meet the standards after the second re-inspection, the external control center controls the drain control valve to open and drain the wastewater to the wastewater tank through the drain branch pipe.

[0054] The rest of this embodiment is the same as that in Embodiment 1. Features not explained in this embodiment are explained using the methods in Embodiment 1, and will not be repeated here.

[0055] The above description is only a preferred embodiment of the present invention. For those skilled in the art, there will be changes in the specific implementation and application scope based on the ideas of the present invention. The content of this specification should not be construed as a limitation of the present invention.

Claims

1. A sponge city structure, characterized in that: It includes a first diversion zone (1), an overflow treatment zone (2), and an infiltration zone (3); the overflow treatment zone (2) is located between the first diversion zone (1) and the infiltration zone (3). Rainwater is diverted from the first diversion zone (1) to the overflow treatment zone (2). The overflow treatment zone (2) is used to buffer and purify the rainwater diverted from the first diversion zone (1). The rainwater overflowing from the overflow treatment zone (2) flows into the infiltration zone (3) for auxiliary buffering and purification. The overflow treatment area (2) includes a treatment pool (4), an overflow unit (6) installed on the treatment pool (4), an overflow port connecting pipe (7) connected to the bottom of the treatment pool (4), and a rainwater treatment mechanism (8) connected to the end of the overflow port connecting pipe (7) away from the treatment pool (4). The overflow unit (6) includes a sludge intercepting basket (9) installed on the treatment pool (4) and an overflow well cover (11) covering the sludge intercepting basket (9). The overflow well cover (11) is provided with multiple sets of through grooves (12) evenly distributed. After the rainwater flows into the sludge intercepting basket (9) through the through grooves (12), the sludge intercepting basket (9) intercepts the impurities in the rainwater and the rainwater flows into the treatment pool (4). The rainwater in the treatment pool (4) flows into the rainwater treatment mechanism (8) through the overflow port connecting pipe (7). 2.The sponge city structure of claim 1, wherein: The intercepting basket (9) includes a main body (13) and a snap-fit ​​boss (14) provided on the main body (13). A first L-shaped step (15) is provided at the connection between the first diversion zone (1) and the overflow treatment zone (2). A second L-shaped step (16) is provided at the connection between the overflow treatment zone (2) and the infiltration zone (3). The intercepting basket (9) is detachably snapped onto the first L-shaped step (15) and the second L-shaped step (16) via the snap-fit ​​boss (14).

3. The sponge city structure according to claim 2, characterized in that: The main body (13) includes a hollow basket (17) and a graded filter layer (18) disposed in the hollow basket (17). The graded filter layer (18) includes a coarse pore filter layer (19), a medium pore filter layer (21), and a fine pore filter layer (22). The fine pore filter layer (22) is disposed between the inner wall of the hollow basket (17) and the medium pore filter layer (21). The medium pore filter layer (21) is disposed between the fine pore filter layer (22) and the coarse pore filter layer (19). The coarse pore filter layer (19) is disposed on the side of the medium pore filter layer (21) away from the fine pore filter layer (22). Each filter layer is detachably fixed in the hollow basket (17) by a slot. The graded filter layer (18) is used for the initial filtration of rainwater. 4.The sponge city structure of claim 1, wherein: The overflow treatment area (2) also includes a first water level detection component (23) installed in the treatment tank (4) and a water replenishment device (400) installed on the overflow unit (6). A first drain valve body (24) is provided between the overflow port connecting pipe (7) and the rainwater treatment mechanism (8). The first drain valve body (24) is used to realize the flow of water between the overflow port connecting pipe (7) and the rainwater treatment mechanism (8). The first water level detection component (23), the first drain valve body (24) and the water replenishment device (400) are all connected to the external control center. When the overflow unit (6) is blocked, after the preset conditions are met, the external control center controls the first drain valve body (24) to close. The first water level detection component (23) detects the water level in the treatment tank (4), and the water replenishment device (400) replenishes the overflow unit (6) with test water according to the water level data in the treatment tank (4). The water tank reaches the preset water level test value. The water replenishment device (400) then replenishes the overflow unit (6) of the treatment tank (4) that has reached the preset water level test value within a preset time to obtain the first water level data. When the preset time has elapsed since the first water level detection time and the preset conditions are met, the external control center controls the first drain valve (24) to close again. The first water level detection component (23) detects the water level in the treatment tank (4). The water replenishment device (400) replenishes the overflow unit (6) with test water according to the water level data in the treatment tank (4) so ​​that the water tank reaches the preset water level test value. The water replenishment device (400) then replenishes the overflow unit (6) of the treatment tank (4) that has reached the preset water level test value within a preset time to obtain the second water level data. The external control center presets the water level change difference threshold and completes the blockage judgment by comparing the water level data of the two tests.

5. A sponge city structure according to claim 1, characterized in that: The infiltration zone (3) includes a geotextile (25) placed on the outer soil layer, a first gravel drainage layer (26) placed on the geotextile (25), a medium sand filter layer (27) placed on the first gravel drainage layer (26), a planting soil layer (28) placed on the medium sand filter layer (27), a second gravel drainage layer (29) placed on the planting soil layer (28), and a lawn shrub bio-water storage layer (31) placed on the second gravel drainage layer (29); the first gravel drainage layer The particle size of the water layer (26) is smaller than that of the second gravel drainage layer (29). The first gravel drainage layer (26) extends to the bottom of the treatment tank (4) and is connected to the rainwater treatment mechanism (8) via the guide section (32). Rainwater that infiltrates through the infiltration zone (3) flows into the rainwater treatment mechanism (8). The guide section (32) is equipped with a shut-off valve for connecting and disconnecting the infiltration zone (3) and the rainwater treatment mechanism (8). The shut-off valve is connected to the external control center and is linked to the first sewage valve (24) for control.

6. A sponge city structure according to claim 1, characterized in that: The rainwater treatment mechanism (8) includes a first treatment unit (33), a water storage tank (34) connected to the first treatment unit (33), and a second drain valve body (35) located at the connection between the first treatment unit (33) and the water storage tank (34). The first treatment unit (33) includes a first water quality testing mechanism (36) and a water purification device (37). The second drain valve body (35), the first water quality testing mechanism (36), and the water purification device (37) are all electrically connected to an external control center. The first water quality testing mechanism (36) is used for... The system detects the rainwater quality parameters flowing into the first treatment unit (33) in real time and transmits the detection data to the external control center. The external control center adjusts the operation status of the water purification equipment (37) according to the water quality detection data. When the first water quality detection agency (36) detects that the rainwater quality meets the standards, the external control center controls the second sewage valve (35) to open, so that the purified rainwater flows into the water storage tank (34) for storage and reuse. When the water quality does not meet the standards, the external control center controls the second sewage valve (35) to close, and at the same time adjusts the water purification equipment (37) to strengthen the purification treatment.

7. A sponge city structure according to claim 6, characterized in that: The water purification equipment (37) includes a first pool (38) and a return pool (39) connected to the first pool (38); the first pool (38) is provided with a sediment adsorption layer (41) and a disinfection layer (42) located below the sediment adsorption layer (41) and connected to the sediment adsorption layer (41) via a first pipe (48); one end of the disinfection layer (42) is connected to a water storage tank (34), and the other end is connected to the return pool (39) via a third drain valve body (43); The sediment adsorption layer (41) includes a honeycomb adsorption plate (44), a modified zeolite filler layer (45), and an activated carbon fiber layer (46) arranged sequentially from top to bottom. The honeycomb adsorption plate (44) has several arc-shaped adsorption grooves on its surface, and the arc-shaped adsorption grooves are filled with magnetic adsorption particles for the initial adsorption of large-diameter sediment particles in rainwater. The modified zeolite filler layer (45) is composed of zeolite particles modified by hydrochloric acid and is used to adsorb fine sediment and some heavy metal ions in rainwater. The carbon fiber layer (46) has a needle-punched felt structure for adsorbing residual fine silt and organic pollutants; the silt adsorption layer (41) and the disinfection layer (42) are connected via an inclined guide plate (47), and a first pipe (48) is set at the inclined end of the inclined guide plate (47). A filter buffer assembly (49) is provided above the first pipe (48) between the silt adsorption layer (41) and the disinfection layer (42). The filter buffer assembly (49) includes stainless steel screens laid sequentially from top to bottom. (51) Non-woven filter pad (52) and support grid (53), the edge of the filter buffer assembly (49) is sealed and fitted to the inner wall of the first pool body (38), the inlet of the first pipe (48) is directly opposite the center of the support grid (53), and a horn-shaped buffer cover is provided at the inlet of the first pipe (48); after the rainwater undergoes secondary filtration treatment through the mud and sand adsorption layer (41), it flows into the disinfection layer (42). When the rainwater in the disinfection layer (42) reaches the preset liquid level, the disinfection and filtration treatment is started.

8. A sponge city structure according to claim 7, characterized in that: The disinfection layer (42) includes a disinfection tank (54), an ultraviolet disinfection lamp (55) installed in the disinfection tank (54), a liquid level sensor (56), and an aeration device (57). A first water quality testing unit (36) is installed in the disinfection layer (42). The aeration device (57) includes an aeration pump (58), an aeration main pipe (59) extending to the bottom of the disinfection tank (54), and aeration heads (61) evenly distributed on the aeration main pipe (59), used to introduce air into the disinfection tank (54) to increase the dissolved oxygen content of the water and enhance the decomposition of pollutants. The ultraviolet disinfection lamp (55) extends along the disinfection tank (54). The disinfection pool (54) is evenly arranged along its length, and the ultraviolet disinfection lamps (55) are covered with quartz protective sleeves to kill microorganisms in the rainwater. After being treated by the sediment adsorption layer (41) and the filter buffer assembly (49), the rainwater flows into the disinfection pool (54). The external control center synchronously starts the aeration device (57) and the ultraviolet disinfection lamps (55) according to the signal from the liquid level sensor (56) in the disinfection pool (54). The first water quality testing agency (36) monitors the rainwater quality parameters at the outlet of the disinfection pool (54) in real time and transmits the data to the external control center. If the water quality meets the standards, the external control center will activate the aeration device (57) and the ultraviolet disinfection lamps (55). The second drain valve (35) between the central control disinfection tank (54) and the water storage tank (34) is opened, and rainwater flows into the water storage tank (34) for storage and reuse; if the water quality fails to meet the standards, the external control center controls the third drain valve (43) between the disinfection tank (54) and the return tank (39) to open, and discharges the substandard rainwater into the return tank (39) for temporary storage; the return tank (39) includes a return container tank (100), a second water level detection component (200) installed in the return container tank (100), and a return mechanism (300). When the second water level detection component (200) detects the return container... When the water level in the receiving pool (100) reaches the preset value, the external control center simultaneously closes the on / off valves of the first sewage valve body (24) and the guide section (32). The return mechanism (300) controls the non-compliant rainwater in the return pool (39) to return to the disinfection layer (42) for secondary purification treatment. Before returning, the residual rainwater in the disinfection layer (42) is emptied. The first water quality testing agency (36) retests the non-compliant rainwater after secondary purification treatment. The qualified rainwater flows into the water storage pool (34) through the second sewage valve body (35) for storage and reuse. The unqualified rainwater flows into the external wastewater pool.

9. A sewage treatment system based on a sponge city structure, comprising the following steps: S1. Rainwater is diverted to the overflow treatment area (2) through the first diversion zone (1). The rainwater flows into the intercepting basket (9) through the overflow manhole cover (11) channel. After the primary filtration treatment by the graded filter layer (18), it flows into the treatment pool (4). S2. The treatment tank (4) receives and buffers the rainwater after primary filtration. Under normal operating conditions, the first drain valve (24) remains open, and the rainwater flows into the rainwater treatment mechanism (8) through the overflow port connection pipe (7). If the rainwater in the treatment tank (4) exceeds its carrying capacity, the excess rainwater overflows into the infiltration zone (3). During the normal blockage test, the external control center closes the first drain valve (24) and judges the blockage situation by comparing the water level data of the first water level detection component (23). S3. The rainwater flowing into the infiltration zone (3) is assisted in purification by multiple media. After purification, it flows into the rainwater treatment mechanism (8) through the guide part (32) with the on / off valve body, and merges with the rainwater in the overflow treatment zone (2) to enter the subsequent deep treatment stage. S4. The merged rainwater enters the first treatment unit (33) of the rainwater treatment facility (8), and is filtered through the sediment adsorption layer (41) and the filter buffer component (49) in sequence before flowing into the disinfection layer (42). The external control center simultaneously starts the aeration device (57) and the ultraviolet disinfection lamp (55), and through aeration and oxygenation, the synergistic effect of pollutant decomposition and ultraviolet sterilization is enhanced to complete the deep purification of rainwater. S5. The first water quality testing agency (36) monitors the effluent water quality of the disinfection layer (42) in real time and transmits the data to the external control center; if the water quality meets the standard, the second sewage valve (35) is opened and the rainwater flows into the water storage tank (34) for storage and reuse; if the water quality does not meet the standard, the second sewage valve (35) is closed and discharged into the return pool (39) for temporary storage; S6. The second water level detection component (200) in the return pool (39) monitors the water level in real time. When the water level reaches the preset value, the external control center controls the first sewage valve body (24) and the on / off valve body to close. Then the return mechanism (300) starts to return the substandard rainwater in the return pool (39) to the disinfection layer (42) for secondary purification. After purification, the first water quality detection mechanism (36) tests the water quality of the disinfection layer (42) again. The rainwater that passes the retest flows into the water storage tank (34) for storage and reuse, while the rainwater that fails the retest is discharged into the external wastewater tank.

10. A sewage treatment system for a sponge city structure according to claim 9, characterized in that: S2 also includes S2.1 Conventional blockage test: When the preset condition of "no rainfall" is met, the external control center sends a control signal to close the first drain valve (24), the first water level detection component (23) detects the water level in the treatment tank (4), and the water replenishment device (400) replenishes the overflow unit (6) with test water according to the water level data in the treatment tank (4) so ​​that the water tank reaches the preset value of the water level test. The external control center immediately starts the timing module. At the same time as the timing starts, the water replenishment device (400) is started again. The water replenishment device (400) replenishes water for the second time at a constant flow rate of 10L / min. The timing lasts for 5 minutes. After the timing ends, the water replenishment device (400) is turned off. The first water level detection component (23) detects the first water level data Δh1 in the treatment tank (4). When the preset condition of "no rainfall" is met and the time between the first water level detection and the preset value is reached, the water level test is performed. When the time is set, the external control center controls the first drain valve (24) to close again, the first water level detection component (23) detects the water level in the treatment tank (4), the water replenishment device (400) replenishes the overflow unit (6) with test water according to the water level data in the treatment tank (4) so ​​that the water tank reaches the preset water level test value, the water replenishment device (400) replenishes water for the second time at a constant flow rate of 10L / min, the timer lasts for 5 minutes, after the timer ends, the water replenishment device (400) is closed, the first water level detection component (23) detects the second water level data Δh2 in the treatment tank (4); the external control center presets the water level change difference threshold ΔH, if the absolute difference between the two water level change data |Δh2-Δh1|≤ΔH, it is determined that the overflow unit (6) is not blocked; if |Δh2-Δh1|>ΔH, it is determined that the overflow unit (6) is blocked.

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