Sponge city rainwater purification and collection system and rainwater treatment method

Abstract

The sponge city rainwater purification and collection system comprises an initial rainfall processing module, a first rainfall processing and collection module, a second rainfall processing and collection module, a third rainfall processing and collection module, a control module and an energy supply module, wherein the initial rainfall processing module is connected to a sewage drainage pipe, a sewage valve is arranged between the initial rainfall processing module and the sewage discharge pipe, a first water pump is arranged in the first rainfall processing and collection module, a first valve is arranged between the initial rainfall processing module and the first rainfall processing and collection module, the first rainfall processing and collection module is also connected to the second rainfall processing and collection module, the second rainfall processing and collection module is provided with a second water pump, a second valve is arranged between the first rainfall processing and collection module and the second rainfall processing and collection module, the second rainfall processing and collection module is connected to the third rainfall processing and collection module, and the third rainfall processing and collection module is provided with a third water pump. The present invention also provides a sponge city rainwater treatment method.

Description

Technical Field

[0001] The present invention relates to the technical field of sponge city construction, and in particular to a sponge city rainwater purification and collection system and a rainwater treatment method. Background Art

[0002] my country is a country with relatively scarce water resources, with per capita water resources accounting for only 28% of the world average. According to statistics in 2017, my country's total water consumption has exceeded 610 billion cubic meters, but the national water shortage is still more than 50 billion cubic meters, and nearly two-thirds of cities are short of water to varying degrees. With the continuous development of the economy and society, the contradiction between water supply and demand will become more prominent for a considerable period of time in the future.

[0003] Urban water is a general term for water required for urban production, life, firefighting, municipal management and other activities. At present, urban water use is mainly achieved through the following methods: First, the use of rivers, lakes and reservoirs, which is more suitable for areas with abundant precipitation resources; second, the exploitation of groundwater. At present, most water-deficient cities use the method of exploiting groundwater to maintain urban water use. Many cities have caused the water level to drop due to over-exploitation of groundwater, which is particularly obvious in arid inland cities; third, seawater desalination, but because coastal cities generally have abundant precipitation resources and the cost of seawater desalination is relatively high, it is currently less used.

[0004] Most areas in China have the problem of concentrated rainfall. When the sewage and rainwater diversion system is implemented, sewage is collected by drainage pipes, sent to sewage treatment, and then discharged into water bodies or recycled; rainwater runoff is collected by drainage pipes and discharged into nearby water bodies. In the past, the social aesthetic believed that the better the hardening of the city, the more high-end, atmospheric, and upscale it would appear. At the same time, the design of the drainage network could not keep up with the speed of urban development, which led to urban waterlogging every rainy season. Therefore, it is very necessary to make good use of rainfall to alleviate urban water use and urban waterlogging problems. Sponge city is a new generation of urban stormwater management concept, and the internationally accepted term is "low-impact development rainwater system construction".

[0005] The water used in cities for production, life, firefighting, municipal management and other activities has different requirements for water quality for different purposes, so the collection and treatment of rainfall are also different. At present, the construction of sponge cities is in its early stages, and the utilization of rainfall is still imperfect. There are problems such as high infrastructure construction costs, high maintenance costs, short lifespan, and unreasonable rainwater utilization. Summary of the invention

[0006] In view of this, it is necessary to provide a low-cost sponge city rainwater purification and collection system that can grade and utilize rainwater.

[0007] The invention also provides a method for treating rainwater in a sponge city.

[0008] A sponge city rainwater purification and collection system includes an initial rainfall processing module, a first rainfall processing and collection module, a second rainfall processing and collection module, a third rainfall processing and collection module, a control module and an energy supply module. The initial rainfall processing module is connected to a sewage drainage pipe to discharge the initial rainfall into the sewage pipe and be treated by a sewage treatment plant. A sewage valve is arranged between the initial rainfall processing module and the sewage discharge pipe to control the discharge of rainfall into the sewage discharge pipe. The initial rainfall processing module is also connected to the first rainfall processing and collection module to discharge rainwater after a predetermined flow from the initial rainfall processing module into the first rainfall processing and collection module. The first rainfall processing and collection module filters floating impurities in the rainwater and collects the filtered rainwater by sedimentation. A first water pump is arranged in the first rainfall processing and collection module to output the rainwater collected by sedimentation as fire-fighting water through the first water pump. A first valve is arranged between the initial rainfall processing module and the first rainfall processing and collection module to control the discharge of rainfall into the first rainfall processing and collection module. The first rainfall processing and collection module is also connected to the second rainfall processing and collection module to discharge the rainwater after sedimentation into the second rainfall processing and collection module. A rainwater treatment and collection module is provided to filter suspended impurities in rainwater and collect rainwater. A second rainwater treatment and collection module is provided with a second water pump to output rainwater after filtering suspended impurities as irrigation or landscape water through the second water pump. A second valve is provided between the first rainwater treatment and collection module and the second rainwater treatment and collection module to control the discharge of rainwater to the second rainwater treatment and collection module. The second rainwater treatment and collection module is connected to the third rainwater treatment and collection module to discharge the filtered rainwater into the third rainwater treatment and collection module to remove odor and color from the rainwater and collect rainwater. The third rainfall processing and collection module is provided with a third water pump to output the rainwater with odor and color removed as cleaning water through the third water pump. A third valve is provided between the second rainfall processing and collection module and the third rainfall processing and collection module to control the discharge of rainwater to the third rainfall processing and collection module. The control module is provided with a liquid level sensor, and the control module is electrically connected to the sewage valve, the first valve, the second valve, and the third valve to control the flow direction of rainwater. The energy supply module is electrically connected to the control module, the sewage valve, the first valve, the second valve, and the third valve to provide electrical energy.

[0009] A method for treating rainwater in a sponge city comprises the following steps:

[0010] Step S001, open the sewage valve and close the first valve to allow rainwater to enter the urban drainage pipe from the initial rainfall processing module for sewage treatment;

[0011] Step S002, when the real-time flow value detected by the flow meter is greater than the predetermined flow value set by the controller, the sewage valve is closed, and the first valve is opened to allow rainwater to enter the first rainfall processing and collection module, and the rainwater is filtered and settled to remove floating objects and sediments in the rainwater. The rainwater in the first rainfall processing and collection module is used as fire-fighting water or road spraying water;

[0012] Step S003, when the liquid level of the rainfall in the first rainfall processing and collection module detected by the first liquid level sensor is higher than the set first reference liquid level, the controller opens the second valve to allow water to enter the second rainfall processing and collection module, filters the rainwater to remove suspended matter in the rainwater, and the rainwater in the second rainfall processing and collection module is used as garden irrigation water;

[0013] Step S004, when the liquid level of rainfall in the Disney rainfall processing and collection module detected by the second liquid level sensor is higher than the set second reference liquid level, the controller opens the third valve to allow water to enter the third rainfall processing and collection module, filters the rainwater to remove the color and odor in the rainwater, and the rainwater in the third rainfall processing and collection module is used as cleaning water.

[0014] Beneficial effects: The sponge city rainwater purification and collection system of the present invention includes an initial rainfall processing module, a first rainfall processing and collection module, a second rainfall processing and collection module, a third rainfall processing and collection module, a control module and an energy supply module to perform graded treatment on rainwater, and each level of rainwater can be reasonably utilized, and the cost of rainwater treatment is significantly reduced. The sponge city rainwater treatment method of the present invention can reasonably process and utilize rainwater, making the utilization cost of rainwater lower, and at the same time can prevent the initial rainfall from being discharged into the natural water system to pollute the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a functional module diagram of the sponge city rainwater purification and collection system of the present invention.

[0016] In the figure: sponge city rainwater purification and collection system 10, initial rainfall processing module 20, sewage valve 201, first rainfall processing and collection module 30, first valve 301, second rainfall processing and collection module 40, second valve 401, third rainfall processing and collection module 50, third valve 501, control module 60, flow meter 601, first liquid level sensor 602, second liquid level sensor 603, third liquid level sensor 604, controller 605. DETAILED DESCRIPTION

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Please see Figure 1The sponge city rainwater purification and collection system 10 includes an initial rainfall processing module 20, a first rainfall processing and collection module 30, a second rainfall processing and collection module 40, a third rainfall processing and collection module 50, a control module 60 and an energy supply module. The initial rainfall processing module 20 is connected to the sewage drainage pipe to discharge the initial rainfall into the sewage pipe and be treated by the sewage treatment plant. A sewage valve 201 is set between the initial rainfall processing module 20 and the sewage discharge pipe to control the discharge of rainfall into the sewage discharge pipe. The initial rainfall processing module 20 is also connected to the first rainfall processing and collection module 30 to discharge the rainwater after a predetermined flow from the initial rainfall processing module 20. The rainwater is discharged into the first rainfall processing and collection module 30, which filters the impurities floating in the rainwater and collects the filtered rainwater by settling. The first rainfall processing and collection module 30 is provided with a first water pump to output the rainwater collected by settling as fire water through the first water pump. A first valve 301 is provided between the initial rainfall processing module 20 and the first rainfall processing and collection module 30 to control the discharge of rainfall to the first rainfall processing and collection module 30. The first rainfall processing and collection module 30 is also connected to the second rainfall processing and collection module 40 to discharge the rainwater after settling into the second rainfall processing and collection module 4 0, to filter the impurities suspended in the rainwater and collect the rainwater, the second rainfall processing and collection module 40 is provided with a second water pump, to output the rainwater after filtering the suspended impurities as irrigation or landscape water through the second water pump, a second valve 401 is provided between the first rainfall processing and collection module 30 and the second rainfall processing and collection module 40, to control the rainwater to be discharged to the second rainfall processing and collection module 40, the second rainfall processing and collection module 40 is connected to the third rainfall processing and collection module 50, to discharge the filtered rainwater into the third rainfall processing and collection module 50, to remove the odor and color in the rainwater and collect the rainwater, the third rainfall processing and collection module 50 is provided with There is a third water pump to output the rainwater with odor and color removed as cleaning water through the third water pump. A third valve 501 is provided between the second rainfall processing and collection module 40 and the third rainfall processing and collection module 50 to control the discharge of rainwater to the third rainfall processing and collection module 50. The control module 60 is provided with a liquid level sensor, and the control module 60 is electrically connected to the sewage valve 201, the first valve 301, the second valve 401, and the third valve 501 to control the flow direction of rainwater. The energy supply module is electrically connected to the control module 60, the sewage valve 201, the first valve 301, the second valve 401, and the third valve 501 to provide electrical energy.

[0019] After rainwater falls on the ground, it is greatly affected by the pollutants on the ground. For different grounds, the difference in pollutants is also large. If the ground is mainly grass and trees, then the rainwater contains more dead branches and rotten leaves. Due to the uneven quality of people, the ground also contains cigarette butts, garbage and even human or animal excrement. The sponge city rainwater purification and collection system 10 of the present invention first discharges rainwater containing relatively dirty pollutants into the city's sewage network for treatment through the initial rainfall treatment module 20. The prior art generally discharges this part of rainwater into the nearby natural water system through a drainage pipe. This drainage method easily brings pollutants into the natural water system, thereby causing environmental pollution. The sponge city rainwater purification and collection system 10 of the present invention can avoid the occurrence of the above situation. As the rainfall continues, some pollutants that are easily taken away from the ground are blocked outside the initial rainfall treatment module 20, and some pollutants flow into the first rainfall treatment and collection module 30 along with the initial rainfall treatment module 20. The floating objects contained in the rainwater are characterized by large area and light weight. The first rainfall treatment and collection module 30 first filters out the floating objects contained in the rainwater. At the same time, after sedimentation, heavy debris such as mud, gravel, etc. in the rainwater are eliminated. The filtered rainwater does not contain large particles and is relatively clean. The quality requirements of fire-fighting water are not high. At the same time, the water does not contain sediment, which has no effect on fire-fighting water storage equipment. Therefore, the rainwater treated by the first precipitation treatment and collection module can be used as fire-fighting water or road spraying water. However, some small particles and suspended matter still exist in the rainwater. If it is used for garden sprinkler irrigation, drip irrigation, etc., it is easy to cause pipe blockage and damage to irrigation equipment. The second rainfall treatment and collection module 40 further removes the suspended matter contained in the rainwater, so that the rainwater is further processed, so that it can be used for garden irrigation and landscape water. At present, tap water is used for daily cleaning water. Due to the high quality of tap water, the cost of water treatment is also high. In places such as office buildings, the demand for cleaning water is large, which increases the cost of water use. The rainwater treated by the second precipitation treatment and collection module contains a small amount of pigment and odor, which does not meet the requirements of cleaning water. The third precipitation treatment and collection module can remove the color and odor in the rainwater, so that the rainwater can be used for cleaning. Since rainwater also contains bacteria, viruses and other components, it is not suitable for animals to drink or people to wash their bodies. However, the cost of processing these components is high, which conflicts with the technical problem to be solved by the present invention and is therefore not considered.

[0020] Furthermore, the control module 60 includes a flow meter 601, a first liquid level sensor 602, a second liquid level sensor 603, a third liquid level sensor 604, and a controller 605. The flow meter 601 is arranged in the initial rainfall processing module 20 to detect the flow of rainwater entering the initial rainfall processing module 20. The first liquid level sensor 602 is arranged in the first rainfall processing and collection module 30 to detect the liquid level information of rainwater in the first rainfall processing and collection module 30. The second liquid level sensor 603 is arranged in the second rainfall processing and collection module 40 to detect the liquid level information of rainwater in the second rainfall processing and collection module 40. The third liquid level sensor 604 is arranged in the third rainfall processing and collection module 50 to detect the liquid level information of rainwater entering the third rainfall processing and collection module 50.

[0021] Furthermore, the control module 60 also includes a rainwater storage time alarm unit to remind personnel to prevent rainwater from deteriorating due to too long storage time. The rainwater storage time alarm unit includes a timer and an alarm light. The timer is electrically connected to the alarm light. The timer is set with a preset time value. When rainwater stops flowing into the sponge city rainwater purification and collection system 10, the timer starts timing. When the timing time exceeds the preset time value, the timer controls the alarm light to light up to remind the staff.

[0022] Furthermore, the initial rainfall processing module 20 includes a plurality of drainage branch pipes, a grille plate, a collecting pipe, and a sewage valve 201. One end of the drainage branch pipe is fixedly connected to the grille plate to prevent branches and garbage exceeding a predetermined volume from being carried away by the water flow and entering the drainage branch pipe. The other end of the drainage branch pipe is connected to the collecting pipe to collect rainwater in the drainage branch pipe into the collecting pipe. The collecting pipe is provided with two through holes for installing the sewage valve 201 and the first valve 301.

[0023] In a preferred embodiment, the flow meter 601 is disposed in the collecting pipe.

[0024] Furthermore, the first rainfall processing and collection module 30 includes a first filter screen, a first water pool, and a first water pump. The first filter screen is mounted on the first water pool to remove floating substances in the rainwater. A first water inlet is provided above the side wall of the first water pool, and the first water inlet is connected to the initial rainfall processing module 20. The filter screen is located below the first water inlet. A first water outlet is provided on the side wall opposite to the first water inlet, and the first water outlet is connected to the second rainfall processing and collection module 40. The second valve 401 is located between the first water outlet and the second rainfall processing and collection module 40. The bottom of the first water pool is conical, and an outlet is provided at the bottom of the first water pool. The outlet is provided with an outlet valve to control the discharge of sediment. The first water pump is arranged in the first water pool to output the rainwater after sedimentation and collection as fire-fighting water.

[0025] In a preferred embodiment, the first liquid level sensor 602 is arranged in the first water tank, and the controller 605 is provided with a first reference liquid level value. When the first liquid level sensor 602 detects that the liquid level of the first water tank is higher than the first reference liquid level value, the controller 605 opens the second valve 401 to allow water to enter the second rainfall processing and collection module 40.

[0026] Furthermore, the second rainfall processing and collection module 40 includes a second filter screen, a second water pool, and a second water pump. The second filter screen is mounted on the second water pool to remove impurities suspended in rainwater. A second water inlet is provided above the side wall of the second water pool. The second water inlet is connected to the first water outlet so that rainwater enters the second water pool from the second water inlet. A second water outlet is also provided on the side wall of the second water pool. The second water outlet is connected to the third rainfall processing and collection module 50. The third valve 501 is located between the second water outlet and the third rainfall processing and collection module 50. The second water pump is arranged in the second water pool to output the filtered rainwater as irrigation or landscape water.

[0027] In a preferred embodiment, the second liquid level sensor 603 is arranged in the second water tank, and the controller 605 is provided with a second reference liquid level value. When the second liquid level sensor 603 detects that the liquid level of the second water tank is higher than the second reference liquid level value, the controller 605 opens the second valve 401 to allow water to enter the third rainfall processing and collection module 50.

[0028] In a preferred embodiment, the second filter is a sponge.

[0029] Furthermore, the third rainfall processing and collection module 50 includes a water tank, an activated carbon filter layer, and a third water pump. The water tank is provided with a third water inlet, which is connected to the second water outlet. The activated carbon filter layer is located in the third water inlet. The cross-section of the activated carbon filter layer matches the shape of the third water inlet to fully filter the rainwater, thereby removing the color and odor in the rainwater.

[0030] In a preferred embodiment, the third liquid level sensor 604 is disposed in the water tank, and the controller 605 is provided with a third reference liquid level value. When the third liquid level sensor 604 detects that the liquid level in the water tank is higher than the third reference liquid level value, the controller 605 closes the third valve 501 to reduce the consumption of activated carbon.

[0031] It should be noted that the filtering device involved in the present invention is a consumable and needs to be cleaned or replaced after being used for a period of time. Therefore, the first filter screen, the second filter screen, and the activated carbon filter layer in the present invention are all detachable.

[0032] In a preferred embodiment, the collection pipe is further provided with a water-stop gate. When the liquid levels detected by the first liquid level sensor 602, the second liquid level sensor 603, and the third liquid level sensor 604 all reach the set liquid levels, the controller 605 closes the water-stop gate to stop the external rainwater from entering the sponge city rainwater purification and collection system 10, so as to prevent the system from being damaged.

[0033] The rainwater treatment steps of the present invention are as follows:

[0034] Step S001, open the sewage valve 201 and close the first valve 301, so that rainwater enters the urban drainage pipe from the initial rainfall processing module 20 for sewage treatment;

[0035] Step S002, when the real-time flow value detected by the flow meter 601 is greater than the predetermined flow value set by the controller 605, the sewage valve 201 is closed, and the first valve 301 is opened to allow rainwater to enter the first rainfall processing and collection module 30, and the rainwater is filtered and settled to remove floating objects and sediments in the rainwater. The rainwater in the first rainfall processing and collection module 30 is used as fire water or road spraying water;

[0036] Step S003, when the liquid level of the rainfall in the first rainfall processing and collection module 30 detected by the first liquid level sensor 602 is higher than the set first reference liquid level, the controller 605 opens the second valve 401 to allow water to enter the second rainfall processing and collection module 40, filters the rainwater to remove suspended matter in the rainwater, and the rainwater in the second rainfall processing and collection module 40 is used as garden irrigation water;

[0037] Step S004, when the liquid level of rainfall in the Disney rainfall processing and collection module detected by the second liquid level sensor 603 is higher than the set second reference liquid level, the controller 605 opens the third valve 501 to allow water to enter the third rainfall processing and collection module 50, and filters the rainwater to remove the color and odor in the rainwater. The rainwater in the third rainfall processing and collection module 50 is used as cleaning water.

[0038] What is disclosed above is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. A person skilled in the art can understand that all or part of the processes of the above embodiments and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. A sponge city rainwater purification and collection system, characterized by: The system comprises an initial rainfall processing module, a first rainfall processing and collection module, a second rainfall processing and collection module, a third rainfall processing and collection module, a control module and an energy supply module. The initial rainfall processing module is connected with a sewage drainage pipe to discharge the initial rainfall into the sewage pipe and be treated by a sewage treatment plant. A sewage valve is arranged between the initial rainfall processing module and the sewage discharge pipe to control the discharge of rainfall into the sewage discharge pipe. The initial rainfall processing module is also connected with the first rainfall processing and collection module to discharge rainwater after a predetermined flow rate from the initial rainfall processing module into the first rainfall processing and collection module. The first rainfall processing and collection module filters floating impurities in the rainwater and settles the filtered rainwater. The first rainfall processing and collection module is provided with a first water pump to output the rainwater collected after sedimentation as fire-fighting water through the first water pump. A first valve is provided between the initial rainfall processing module and the first rainfall processing and collection module to control the discharge of rainfall to the first rainfall processing and collection module. The first rainfall processing and collection module is also connected to the second rainfall processing and collection module to discharge the rainwater after sedimentation into the second rainfall processing and collection module to filter the impurities suspended in the rainwater and collect the rainwater. The second rainfall processing and collection module is provided with a second water pump to output the rainwater after filtering the suspended impurities as irrigation or landscape water through the second water pump. The first rainfall processing and collection module is connected to the second rainfall processing and collection module. A second valve is provided between the rainwater treatment and collection modules to control the rainwater to be discharged to the second rainwater treatment and collection module. The second rainwater treatment and collection module is communicated with the third rainwater treatment and collection module to discharge the filtered rainwater into the third rainwater treatment and collection module to remove the odor and color in the rainwater and collect the rainwater. The third rainwater treatment and collection module is provided with a third water pump to output the rainwater with the odor and color removed as cleaning water through the third water pump. The control module is provided with a liquid level sensor, and the control module is electrically connected to the sewage valve, the first valve, the second valve, and the third valve to control the flow direction of the rainwater. The energy supply module is connected to the control module, the sewage valve, the first valve, the second valve, and the third valve. The door is electrically connected to provide electric energy; the control module includes a flow meter, a first liquid level sensor, a second liquid level sensor, a third liquid level sensor, and a controller, the flow meter is arranged in the initial rainfall processing module to detect the flow of rainwater entering the initial rainfall processing module, the first liquid level sensor is arranged in the first rainfall processing and collection module to detect the liquid level information of rainwater in the first rainfall processing and collection module, the second liquid level sensor is arranged in the second rainfall processing and collection module to detect the liquid level information of rainwater in the second rainfall processing and collection module, and the third liquid level sensor is arranged in the third rainfall processing and collection module to detect the liquid level information of rainwater entering the third rainfall processing and collection module;The control module also includes a rainwater storage time alarm unit to remind personnel to prevent rainwater from deteriorating due to long storage time. The rainwater storage time alarm unit includes a timer and an alarm light. The timer is electrically connected to the alarm light. The timer is set with a preset time value. When rainwater stops flowing into the sponge city rainwater purification and collection system, the timer starts timing. When the timing time exceeds the preset time value, the timer controls the alarm light to light up to remind the staff. ; 2. The sponge city rainwater purification and collection system according to claim 1, characterized in that: The initial rainfall processing module includes a plurality of drainage branch pipes, a grille plate, a collecting pipe, and a sewage valve. One end of the drainage branch pipe is fixedly connected to the grille plate to prevent branches and garbage exceeding a predetermined volume from being carried away by the water flow and entering the drainage branch pipe. The other end of the drainage branch pipe is connected to the collecting pipe to collect rainwater in the drainage branch pipe into the collecting pipe. The collecting pipe is provided with two through holes for installing the sewage valve and the first valve.

3. The sponge city rainwater purification and collection system according to claim 1, characterized in that: The first rainfall processing and collection module includes a first filter, a first water pool, and a first water pump. The first filter is mounted on the first water pool to remove floating substances in the rainwater. A first water inlet is provided above the side wall of the first water pool, and the first water inlet is connected to the initial rainfall processing module. The filter is located below the first water inlet. A first water outlet is provided on the side wall opposite to the first water inlet, and the first water outlet is connected to the second rainfall processing and collection module. The second valve is located between the first water outlet and the second rainfall processing and collection module. The bottom of the first water pool is conical, and an outlet is provided at the bottom of the first water pool, and an outlet valve is provided at the outlet to control the discharge of sediment. The first water pump is arranged in the first water pool to output the rainwater collected after sedimentation as fire-fighting water.

4. The sponge city rainwater purification and collection system according to claim 1, characterized in that: The second rainfall processing and collection module includes a second filter, a second water pool, and a second water pump. The second filter is mounted on the second water pool to remove impurities suspended in rainwater. A second water inlet is provided above the side wall of the second water pool. The second water inlet is connected to the first water outlet so that rainwater enters the second water pool from the second water inlet. A second water outlet is also provided on the side wall of the second water pool. The second water outlet is connected to the third rainfall processing and collection module. The third valve is located between the second water outlet and the third rainfall processing and collection module. The second water pump is arranged in the second water pool to output filtered rainwater as irrigation or landscape water.

5. The sponge city rainwater purification and collection system according to claim 1, characterized in that: The third rainfall processing and collection module includes a water tank, an activated carbon filter layer, and a third water pump. The water tank is provided with a third water inlet, which is connected to the second water outlet. The activated carbon filter layer is located in the third water inlet. The cross-section of the activated carbon filter layer matches the shape of the third water inlet to fully filter the rainwater, thereby removing the color and odor in the rainwater.

Images