An ecological management method and system for urban agriculture non-point source pollution

Abstract

The application discloses a kind of typical urban agriculture non-point source pollution ecological management method and system, the method specifically includes the following steps: near-source interception purification is carried out to the effluent of pollution source area, and preliminary treatment target is obtained;The preliminary treatment target is intercepted and purified again using ecological ditch, and middle section treatment target is formed, wherein the middle section treatment target flows into receiving water body;An ecological purification system is constructed in the middle section treatment target, terminal purification is carried out, and the final treatment target is obtained.The present application can realize agricultural non-point source pollution interception and purification according to the present situation of production park, and at the same time, water can be recycled.By the synergistic operation of the process, using ecological method, the purpose of interception and purification of most non-point source pollution in production area, pollutant reduction and water resource recycling can be achieved.

Description

Technical Field

[0001] This invention belongs to the field of agricultural water conservancy technology, and in particular relates to a typical urban agricultural non-point source pollution ecological treatment method and system. Background Technology

[0002] In agricultural production, fertilizers, pesticides, and other agricultural chemicals are used on a large scale. However, only a small portion of these chemicals are absorbed by crops; the rest remain in the soil and are then washed into rivers by surface runoff, becoming potential sources of pollution. Agricultural non-point source pollution is characterized by large pollutant emissions and difficulty in concentration. Even with source control measures (such as optimized fertilizer use), some pollutants inevitably continue to be discharged with surface runoff, significantly impacting the water quality of downstream rivers. Furthermore, no single treatment technology can simultaneously solve all these problems.

[0003] Non-point source pollution control is not only an important research topic in the field of watershed water resources, but also the foundation and prerequisite for water environment planning and water management. However, the space for non-point source pollution control in areas with existing agricultural infrastructure is extremely limited. Therefore, it is necessary to proceed from reality, utilize existing conditions, closely integrate with the production processes of regional urban agricultural bases, and adopt integrated treatment processes and systems that are efficient, low-cost, and easy to maintain, so as to achieve a coordinated and highly unified environmental, social, and economic benefit.

[0004] Therefore, there is an urgent need for a typical ecological governance method and system for urban agricultural non-point source pollution to address the shortcomings of existing technologies. Summary of the Invention

[0005] The purpose of this invention is to propose a typical ecological treatment method and system for urban agricultural non-point source pollution, so as to achieve the interception and purification of most non-point source pollution in the production area, the reduction of pollutants and the recycling of water resources.

[0006] On the one hand, to achieve the above objectives, this invention provides a typical ecological treatment method for urban agricultural non-point source pollution, comprising the following steps:

[0007] Near-source interception and purification of pollutants from the area where they are generated are carried out to obtain preliminary target pollutants for treatment.

[0008] The initial treatment target is subjected to secondary interception and purification using ecological ditches to form the intermediate treatment target, wherein the intermediate treatment target flows into the receiving water body;

[0009] An ecological purification system is constructed in the mid-stage treatment target to carry out terminal purification and obtain the final treatment target.

[0010] According to a typical urban agricultural non-point source pollution ecological treatment method provided by the present invention, near-source interception and purification of pollutants generated in the pollutant-generating area is carried out to obtain preliminary treatment target pollutants, including:

[0011] Screening the areas where pollutants are generated in the initial ditches;

[0012] Based on the location of pollution emissions in the area where the pollutants are generated, a nine-square grid purification grid is used to initially intercept and purify the initial ditch.

[0013] According to the drainage flow direction, a stepped ecological purification grid and an in-situ sedimentation purification device are installed;

[0014] Based on the stepped ecological purification grid and the in-situ sedimentation purification device, the discharge from the pollutant-generating area is intercepted and purified in sequence to obtain the preliminary treatment target.

[0015] According to a typical urban agricultural non-point source pollution ecological treatment method provided by the present invention, the initial treatment target is subjected to secondary interception and purification using ecological ditches to form the intermediate treatment target, which includes:

[0016] The existing ditches will be cleaned according to the drainage flow direction, and ecological ditches will be constructed.

[0017] Based on the fact that the ecological ditch meets the target drainage requirements, the walls and shoulders of the existing ditch are revegetated, the bottom of the ditch is filled with filter material and planted with aquatic plants, and then the target object of the initial treatment is intercepted and purified for a second time to form the target object of the middle section treatment.

[0018] According to a typical urban agricultural non-point source pollution ecological treatment method provided by the present invention, an ecological purification system is constructed in the intermediate treatment target to carry out terminal purification, and the final treatment target is obtained by:

[0019] An ecological purification system is established in the target area of ​​the intermediate treatment section, and combined with micro-ecological regulation technology, agricultural pollutants in the target area of ​​the intermediate treatment section are reduced.

[0020] Water purification equipment is installed to control the dissolved oxygen content, microbial quantity and activity of the receiving water body, thereby obtaining the final treatment target.

[0021] On the other hand, in order to achieve the above objectives, the present invention provides a typical urban agricultural non-point source pollution ecological treatment system, including: an ecological ditch interception module, an ecological ditch construction module, and a natural purification module, wherein the ecological ditch interception module, the ecological ditch construction module, and the natural purification module are arranged sequentially according to the drainage flow direction;

[0022] The ecological ditch interception module is used to intercept and purify the discharge from the pollutant-generating area at near source to obtain the initial treatment target.

[0023] The newly constructed ecological ditch module is used to conduct secondary interception and purification of the initial treatment target using the ecological ditch, forming the intermediate treatment target;

[0024] The natural purification module is used to construct an ecological purification system in the intermediate treatment target object to carry out terminal purification and obtain the final treatment target object.

[0025] According to a typical urban agricultural non-point source pollution ecological treatment system provided by the present invention, the ecological ditch interception module includes an ecological ditch interception unit and an in-situ sedimentation purification unit;

[0026] The ecological ditch interception unit includes several nine-square grid purification grids and several stepped ecological purification grids, which are connected in series or in parallel.

[0027] The in-situ sedimentation purification unit adopts an in-situ sedimentation purification device, and the in-situ sedimentation purification device is equipped with a baffle plate inside.

[0028] The in-situ sedimentation purification device, the nine-square grid purification grid, and the stepped ecological purification grid are connected in series. The nine-square grid purification grid is filled with ceramsite, volcanic rock composite ore, and garden organic media. The stepped ecological purification grid is filled with modified zeolite and a mixture of water and steel slag. The in-situ sedimentation purification device is filled with modified zeolite, water and steel slag, and biomass filler.

[0029] According to a typical urban agricultural non-point source pollution ecological treatment system provided by the present invention, the newly constructed ecological ditch module consists of a drainage ditch body, ditch wall, ditch shoulder, aquatic plants at the bottom of the ditch, and a wetland purification unit;

[0030] The ditch walls and shoulders are covered with turf for revegetation. The wetland purification unit is set with filler zones at target intervals along the bottom of the ditch. The filler zones are demarcated on both sides by fir stakes. The filler in the filler zones is modified zeolite and biomass filler.

[0031] According to the present invention, a typical urban agricultural non-point source pollution ecological treatment system is provided, wherein the natural purification module includes constructing a natural ecological unit with local dominant species as the core and setting up water purification equipment based on microbial media in the water resource receiving area, wherein the water purification equipment adopts a high-efficiency aeration and propulsion water purification equipment.

[0032] According to the present invention, a typical urban agricultural non-point source pollution ecological treatment system is provided, wherein the natural ecological unit includes the restoration of aquatic plant planting and local aquatic animal communities;

[0033] The aquatic plants include one or more combinations of Thalia dealbata, water lily, Vallisneria natans, Hydrilla verticillata, Potamogeton crispus, and Myriophyllum spicatum;

[0034] The local aquatic animal community includes one or more combinations of goby, crucian carp, loach, and clam.

[0035] According to a typical urban agricultural non-point source pollution ecological treatment system provided by the present invention, the high-efficiency aeration and flow water purification equipment includes a directional flow and microporous high-efficiency oxygenation subunit, a photocatalytic degradation subunit, and a multi-element solidified microbial carrier;

[0036] The directional flow and microporous high-efficiency oxygenation subunit adopts a micro-nano aeration device, the photocatalytic degradation subunit is formed by loading photocatalytic materials, and the multi-element solidified microbial carrier is made from the by-product of biomass power generation through several processes.

[0037] The present invention has the following beneficial effects:

[0038] This invention employs a near-source interception-transport control-end-of-pipe treatment process, with ecological interception and purification at its core. It constructs three major systems: an ecological ditch interception system, a newly constructed ecological ditch system, and a natural purification system, to implement an ecological treatment method for typical urban agricultural non-point source pollution. Through near-source interception and preliminary purification via ecological ditches, drainage from the nursery area flows through the newly constructed ecological ditch system, where suspended solids and some pollutants are further intercepted before finally flowing into the receiving water body. Based on the characteristics of the production park, while achieving agricultural non-point source pollution interception and purification, the water body can be recycled. Through the synergistic operation of this process and the use of ecological methods, the goals of intercepting and purifying most non-point source pollution, reducing pollutants, and recycling water resources in the production area can be achieved. Attached Figure Description

[0039] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0040] Figure 1 This is a flowchart illustrating a typical urban agricultural non-point source pollution ecological treatment method according to an embodiment of the present invention;

[0041] Figure 2 This is a map showing the location of the main drainage outlets in the ecological planting area proposed in this embodiment of the invention;

[0042] Figure 3A schematic diagram of the nine-grid purification grid system proposed in an embodiment of the present invention (unit: mm);

[0043] Figure 4 This is a schematic diagram of the stepped ecological purification grid proposed in an embodiment of the present invention;

[0044] Figure 5 This is a schematic diagram of the cross-section of the stepped ecological purification grid proposed in an embodiment of the present invention;

[0045] Figure 6 This is a plan view of the sedimentation purification device proposed in an embodiment of the present invention;

[0046] Figure 7 This is a schematic diagram of the sedimentation purification device proposed in an embodiment of the present invention;

[0047] Figure 8 This is a schematic diagram of the newly constructed ecological ditch layout proposed in an embodiment of the present invention;

[0048] Figure 9 This is a schematic diagram of the newly constructed AA section of the ecological ditch proposed in an embodiment of the present invention;

[0049] Figure 10 This is a schematic diagram of the newly constructed BB section of the ecological ditch proposed in an embodiment of the present invention;

[0050] Figure 11 This invention provides a classification of biofilm carrier microbial communities at the phylum level for samples from different time periods, as proposed in this embodiment.

[0051] Figure 12 The present invention describes the removal effect of NH3-N in the embodiments of the present invention. Detailed Implementation

[0052] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present application will now be described in detail with reference to the accompanying drawings and embodiments.

[0053] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0054] like Figure 1 As shown, this embodiment provides a typical ecological treatment method for urban agricultural non-point source pollution, including the following steps:

[0055] Near-source interception and purification of pollutants from the area where they are generated are carried out to obtain preliminary target pollutants for treatment.

[0056] The initial treatment targets are intercepted and purified in a secondary manner using ecological ditches to form the intermediate treatment targets, which then flow into the receiving water body.

[0057] An ecological purification system is constructed in the mid-stage treatment target area to carry out terminal purification and obtain the final treatment target area.

[0058] Furthermore, near-source interception and purification of emissions from the pollutant-generating area are conducted to identify preliminary target pollutants for treatment, including:

[0059] Screening the areas where pollutants are generated in the initial ditches;

[0060] Based on the location of pollution emissions in the pollutant-generating area, a nine-square grid purification grid is used to initially intercept and purify the initial ditch.

[0061] According to the drainage flow direction, a stepped ecological purification grid and an in-situ sedimentation purification device are installed;

[0062] Based on the stepped ecological purification grid and the in-situ sedimentation purification device, the discharge from the pollutant generation area is intercepted and purified in sequence to obtain the initial treatment target.

[0063] Specifically, near-source interception of urban agricultural non-point source pollution, that is, interception near the source in the area where pollutants are generated, mainly includes the modification (interception) of ecological ditches and in-situ sedimentation purification, including the following steps:

[0064] Step 1: Based on the actual site conditions, firstly, according to the location of the key pollution discharge outlets in the nursery production area, a nine-grid purification grid with a small footprint and high treatment efficiency is adopted to achieve initial interception and purification of the discharge outlets in the greenhouse production area.

[0065] Step 2: Based on the analysis of the actual structure and spatial layout of the nursery, the original cement ditch is ecologically transformed, and a stepped ecological purification grid is installed to improve the treatment efficiency and effluent stability of the ecological ditch in the entire nursery area, so as to achieve the interception and purification of most pollutants.

[0066] Step 3: Based on the water system connections and directions in the planting area, install in-situ sedimentation and purification devices to intercept and purify the drainage again, ensuring the treatment efficiency and shock load resistance of the ecological ditches.

[0067] Furthermore, the initial treatment targets are subjected to secondary interception and purification using ecological ditches, forming the intermediate treatment targets, which include:

[0068] The existing ditches were cleaned according to the drainage flow direction, and ecological ditches were constructed.

[0069] Based on the ecological ditches meeting the target drainage requirements, the walls and shoulders of the existing ditches are revegetated, the bottom of the ditches is filled with filter material and planted with aquatic plants, and then the target objects of the initial treatment are intercepted and purified in a secondary manner to form the target objects of the intermediate treatment.

[0070] Specifically, the transport control of non-point source pollution in urban agriculture involves employing efficient and shock-resistant ecological ditch construction technologies along pollutant migration pathways. Ecological ditch design schemes mainly include:

[0071] (1) Identify the main drainage paths in the planting area, and based on the water flow direction, conduct background environmental cleanup in the main production areas and construct new ecological ditches to ensure the purification and stabilization of the receiving water bodies.

[0072] (2) The newly built ecological ditches meet the drainage requirements of the "Irrigation and Drainage Technical Specifications", coordinate with the park landscape, re-green the ditches walls and shoulders, fill the bottom of the ditches with filter material, plant aquatic plants, create a micro wetland purification system for secondary interception and purification, and then merge the water after secondary interception and purification into the receiving water body.

[0073] Furthermore, an ecological purification system is constructed within the intermediate-stage remediation target area to conduct terminal purification, thereby obtaining the final remediation target area, including:

[0074] An ecological purification system was established in the target area of ​​the intermediate treatment section, and combined with micro-ecological regulation technology, agricultural pollutants in the target area of ​​the intermediate treatment section were reduced.

[0075] Water purification equipment is installed to control the dissolved oxygen content, microbial quantity and activity of the receiving water body, thereby obtaining the final treatment target.

[0076] Specifically, end-of-pipe treatment of urban agricultural non-point source pollution involves constructing an ecosystem and habitat centered on local dominant species in the receiving water body to achieve a stable aquatic ecological environment system. This mainly includes:

[0077] (1) Based on nature-based solutions, combined with the drainage needs of the project area, on the basis of ensuring that the water body passes through the ecological ditch interception system and the in-situ sedimentation system, dominant aquatic plants and aquatic animal groups are introduced into the receiving water body. That is, an ecological purification system is constructed in the water body after secondary interception and purification, and combined with micro-ecological regulation technology, the amount of agricultural pollutants is reduced to the maximum extent, while providing conditions for subsequent water recycling in the area.

[0078] (2) Install high-efficiency aeration and propulsion water purification equipment based on microbial media in the receiving water body. The high-efficiency integrated equipment combines photocatalysis, microbial media and aeration and propulsion equipment into one, which can rapidly increase the dissolved oxygen content of the water body, specifically increase the number and activity of microorganisms, and enhance the self-purification capacity of the water body. It can ensure that the water quality of the receiving water body is in a stable and long-term guaranteed state, so that the seasonal drainage of the area will not affect the water quality of the surrounding water system.

[0079] Based on the same general inventive concept, this invention also provides a typical urban agricultural non-point source pollution ecological treatment system. The following describes a typical urban agricultural non-point source pollution ecological treatment system provided by this invention. This system can be referred to in conjunction with the typical urban agricultural non-point source pollution ecological treatment method described above. The system includes: an ecological ditch interception module, an ecological ditch construction module, and a natural purification module, which are arranged sequentially according to the drainage flow direction.

[0080] Specifically, the ecological ditch interception module, the ecological ditch construction module, and the natural purification module are set up sequentially according to the initial pollutants flowing with the drainage, presenting a three-level purification mode.

[0081] The ecological ditch interception module is used to intercept and purify the discharge from the pollutant-generating area at near source, and obtain the initial treatment target.

[0082] Specifically, the ecological ditch interception module intercepts pollutants near their source in the area where they are generated. Its design scheme mainly includes the transformation (interception) of the ecological ditch and in-situ sedimentation purification.

[0083] The newly constructed ecological ditch module is used to conduct secondary interception and purification of the initial treatment target using the ecological ditch, forming the mid-stage treatment target;

[0084] Specifically, the new ecological ditch system uses efficient and shock-resistant ecological ditch construction technology to remove and purify agricultural non-point source pollution along the pollutant migration path.

[0085] The natural purification module is used to build an ecological purification system in the intermediate treatment target to carry out terminal purification and obtain the final treatment target;

[0086] Specifically, the end-of-pipe natural purification module involves constructing an ecosystem and habitat centered on local dominant species in the receiving water body to achieve a stable aquatic ecological environment system.

[0087] Furthermore, the ecological ditch interception module includes an ecological ditch interception unit and an in-situ sedimentation and purification unit;

[0088] The ecological ditch interception unit includes several nine-square grid purification grids and several stepped ecological purification grids, which are connected in series or in parallel.

[0089] The in-situ sedimentation purification unit adopts an in-situ sedimentation purification device, which is equipped with baffles inside the in-situ sedimentation purification device.

[0090] The in-situ sedimentation purification device, the nine-square grid purification grid, and the stepped ecological purification grid are connected in series. The nine-square grid purification grid is filled with ceramsite, volcanic rock composite ore and garden organic media, while the stepped ecological purification grid is filled with modified zeolite and water-steel slag mixture. The in-situ sedimentation purification device is filled with modified zeolite, water-steel slag and biomass filler.

[0091] Specifically, the ecological ditch interception module includes the transformation (interception) of the ecological ditch and in-situ sedimentation purification; the transformation (interception) of the ecological ditch includes multiple nine-square grid purification grilles and multiple stepped ecological purification grilles, which are connected in series or in parallel; the in-situ sedimentation purification uses an in-situ sedimentation purification device to intercept and purify the drainage again at important nodes; the in-situ sedimentation purification device is connected in series with the nine-square grid purification grilles and the stepped ecological purification grilles.

[0092] The nine-grid purification grid is filled from bottom to top with expanded clay, volcanic rock composite ore and garden organic media adsorption material, with a volume ratio of expanded clay: volcanic rock: garden organic media = 1:1:1; the stepped ecological purification grid is filled with a mixture of modified zeolite and steel slag, with a volume ratio of modified zeolite: steel slag = 7:3; the in-situ sedimentation purification device is equipped with baffles, and a mixture of modified zeolite, steel slag and biomass filler is arranged along the water flow direction, with a volume ratio of modified zeolite: steel slag: biomass filler = 5:3:2.

[0093] Furthermore, the newly constructed ecological ditch module consists of the main body of the drainage ditch, the ditch wall, the ditch shoulder, aquatic plants at the bottom of the ditch, and wetland purification units;

[0094] The ditch walls and shoulders are covered with turf for revegetation. The wetland purification unit is set up with filler zones at target intervals along the bottom of the ditch. The filler zones are demarcated on both sides with fir stakes, and the filler in the filler zones is modified zeolite and biomass filler.

[0095] Specifically, the newly constructed ecological ditch module mainly consists of the main body of the drainage ditch, the ditch walls and shoulders, aquatic plants at the bottom of the ditch, and a wetland purification system set at intervals. The ditch walls and shoulders are covered with turf (Manila grass) for revegetation. The wetland purification system is designed along the bottom of the ditch, with a filling zone set at every 20m interval. The filling zone is 10m long and 0.5m deep along the bottom of the ditch, and is demarcated by fir stakes on both sides. The filling material is a mixture of modified zeolite and biomass filler, with a volume ratio of modified zeolite to biomass filler of 1:1. The particle size of the modified zeolite and biomass filler is 15-20mm.

[0096] Furthermore, the natural purification module includes constructing a natural ecological unit with local dominant species as the core and setting up water purification equipment based on microbial media in the water resource receiving area. The water purification equipment adopts a high-efficiency aeration and propulsion water purification equipment.

[0097] Furthermore, the natural ecological environment includes the restoration of aquatic plant cultivation and native aquatic animal communities;

[0098] Aquatic plants include one or more of the following: Thalia dealbata, water lily, Vallisneria natans, Hydrilla verticillata, Potamogeton crispus, and Myriophyllum spicatum.

[0099] The local aquatic animal community includes one or more combinations of goby, crucian carp, loach, and clam.

[0100] Specifically, the planting of aquatic plants will be restored. When the water level is low, plants such as Thalia dealbata, water lilies, and Vallisneria natans will be artificially planted, while plants like Hydrilla verticillata, Potamogeton pectinatus, and Myriophyllum spicatum will naturally regenerate, forming an "underwater forest" covering an area of ​​1000m. 2 Among these findings, the water quality of the receiving water bodies was significantly improved compared to the absence of plants, with aquatic plants increasing nitrogen removal rates to 70%. Within the constructed ecosystem, native aquatic animals such as gobies, crucian carp, loach, and clams were introduced. By establishing a producer-consumer-reducer food chain, the biodiversity index increased tenfold compared to before the treatment.

[0101] Furthermore, the high-efficiency aeration and propulsion water purification equipment includes directional propulsion and microporous high-efficiency oxygenation subunits, photocatalytic degradation subunits, and multi-element solidified microbial carriers;

[0102] Among them, the directional flow and microporous high-efficiency oxygenation subunit adopts a micro-nano aeration device, the photocatalytic degradation subunit is formed by loading photocatalytic materials, and the multi-element solidified microbial carrier is made from the by-product of biomass power generation through several processes.

[0103] Specifically, the directional flow and microporous high-efficiency oxygenation subunit adopts a micro-nano aeration device with an oxygenation efficiency of 6 kg / Kw·h; the photocatalytic degradation subunit is formed by loading the photocatalytic material Fe2O3 / Ti-MCM-41; and the multi-element solidified microbial carrier is made from byproducts of biomass power generation such as agricultural and forestry straw, processed through high-temperature (700-1000℃) calcination, crushing, screening, modification and molding processes.

[0104] Example

[0105] This embodiment addresses the land use pattern, agricultural industry optimization and upgrading, and environmental effects of agricultural development under the rapid urbanization conditions in the suburbs of Shanghai. A novel ecological treatment method for urban agricultural non-point source pollution is implemented at Fanghegu Farm in Wujing Town, Minhang District, Shanghai. The specific implementation is as follows:

[0106] S1. Water system reorganization and optimization;

[0107] This embodiment primarily focuses on streamlining and improving the drainage systems of the nursery, vegetable gardens, and woodlands within the park. The aim is to meet the irrigation and drainage needs of the ecological planting area while identifying the main runoff and drainage paths, the temporal and spatial variations in water volume and quality, the impact of other sewage discharge and runoff, and the soil and water quality of the ditches. This allows for the construction of an ecological ditch interception system, a new ecological ditch system, and a natural purification system at key nodes and sections, implementing a point-line-surface integrated ecological interception and purification project. The specific process is as follows: Figure 1 As shown.

[0108] According to on-site investigation, most of the ditches in the ecological planting area have been completed. Preliminary surveys indicate that drainage from the Fanghe Valley Farm area primarily flows into the semi-enclosed Yezhoujia River (220m long, 10m wide) within the park. The northern end of the Yezhoujia River connects to the outer Yutang River, with a sluice gate controlling the water level within the river. The Yezhoujia River currently has three drainage outlets: one at the southernmost end of the river channel, another at the first road from south to north on the western side of the Fanghe Valley park, and the last one northwest of the Yezhoujia River bridge. Specific locations are as follows... Figure 2 As shown.

[0109] S2, Ecological Ditch Interception System;

[0110] Ecological ditch interception systems for urban agricultural non-point source pollution, which involve near-source interception in the pollutant-generating area, mainly include:

[0111] (1) Based on the actual situation on site, firstly, according to the key pollution emission locations in the nursery production area, a nine-grid purification grid with a small footprint and high treatment efficiency is adopted to achieve preliminary interception and purification of the discharge outlets in the greenhouse production area.

[0112] Specifically, the multi-media nine-grid purification screen is filled with composite minerals such as zeolite, ceramsite, and volcanic rock, along with adsorbent materials such as garden organic media. During operation, a microbial film forms within the screen. Before the park's wastewater enters the river, the composite minerals and organic media purify the wastewater, reducing turbidity and improving water quality indicators, thus achieving the goal of synergistic control of non-point source pollution. The nine-grid purification screen system, for example... Figure 3 As shown, the preliminary design is to install 2 sets.

[0113] (2) Based on the water system communication and direction of the planting area, the original ditches were ecologically transformed and in-situ sedimentation devices were installed to intercept and purify the drainage again, so as to ensure the treatment efficiency and shock load resistance of the subsequent ecological ditches.

[0114] Specifically, the ecological ditch renovation involves ecological transformation of existing cement ditches, designed without damaging the original ditch structure or affecting drainage. The total length of the ecological ditch renovation is approximately 2768m. Prefabricated ditch purification devices, consisting of stepped ecological purification grids, are embedded within the cement ditches. Each device is 1m long, and its cross-sectional structure is designed and installed according to the original ditch structure. This ditch purification device... Figures 4-5 As shown, 20 sets are designed for installation.

[0115] (3) Based on the water system connections and flow patterns within the planting area, and considering the predominantly particulate pollutants in farmland drainage, in-situ sedimentation and purification devices are installed. These devices are primarily designed near the drainage inlets to further intercept and purify the drainage. The design layout, based on the field distribution, ditch structure, and drainage flow, is as follows: Figure 6 As shown.

[0116] Specifically, an in-situ sedimentation purification device is installed at key drainage outlets, designed and fabricated with dimensions of 1.8m in length, 1.5m in width, and 0.6m in depth. The in-situ sedimentation purification device is equipped with baffles, and a mixed packing material consisting of modified zeolite, steel slag, and biomass is arranged along the water flow direction to extend the hydraulic retention time. The chemical composition of the steel slag is shown in Table 1, and the performance indicators of the biomass packing material are shown in Table 2. Considering the migration pathways and characteristics of pollutants, the packing material arrangement within the device's spatial layout further achieves the interception, filtration, and sedimentation of pollutants. Ultimately, the microbial community formed on and inside the packing material partially degrades and removes pollutants, extending the service life and effective time of the packing material. This embodiment designs one in-situ sedimentation purification device, as shown in the schematic diagram below. Figure 7 As shown.

[0117] Table 1

[0118]

[0119] Table 2

[0120]

[0121] S3, New ecological ditch system;

[0122] The transport control of non-point source pollution in urban agriculture involves creating micro-wetland purification systems by employing efficient and shock-resistant ecological ditch construction technology along the pollutant migration path, based on water flow direction. This ensures the purification and stabilization capacity of receiving water bodies. Specifically:

[0123] (1) The newly constructed ecological ditch, while meeting the drainage requirements of the "Irrigation and Drainage Technical Specifications", will be coordinated with the park landscape. Its walls and shoulders will be covered with turf (Manila grass) for revegetation. The total design length of the newly constructed ecological ditch is approximately 101.0m, and the total paved area is approximately 181.8m². 2 The bottom slope is designed to be appropriately gentle to facilitate plant growth. A schematic diagram of the new ecological ditch layout is shown below. Figure 8 As shown.

[0124] (2) A filling zone is designed every 20m along the bottom of the ditch, with each filling zone being 10m long and 0.5m deep. This filling zone is demarcated on the north and south sides using fir wood stakes. The filling material is a 1:1 mixture of modified zeolite and biomass, with a particle size of 15-20mm, packaged in bags of approximately 10kg each. Iris, calamus, and other aquatic plants can be artificially planted in the filling zone. Irrigation and drainage will come into contact with the microbial film growing on the surface of the filling material and the plant roots, thus purifying the drainage. Each filling zone is 10m long, with a total of two zones. A schematic diagram of the newly constructed ecological ditch is shown below. Figures 9-10 As shown.

[0125] S4, Terminal Natural Purification System

[0126] End-of-pipe treatment of urban agricultural non-point source pollution involves constructing ecosystems and habitats centered on dominant local species in receiving water bodies to achieve natural purification of the water environment. This mainly includes:

[0127] (1) A nature-based solution, combined with the drainage needs of the project area, ensures that the water body passes through an ecological ditch interception system and an in-situ sedimentation system. It also introduces local dominant aquatic plants and animals into the receiving water body, combined with micro-ecological regulation technology, to maximize the reduction of agricultural pollutants and provide conditions for subsequent water recycling within the area. Specifically:

[0128] Ecosystem construction was carried out within the Yezhoujia River, including the restoration of aquatic plant cultivation. When the water level is low, plants such as Thalia dealbata, water lilies, and Vallisneria natans were artificially planted, while Hydrilla verticillata, Potamogeton pectinatus, and Myriophyllum spicatum naturally regenerated, forming an "underwater forest" covering an area of ​​1000m². 2The river channel has an aquatic plant coverage of approximately 50%, with plant roots and stems providing a suitable microenvironment for microbial growth. Oxygen secretion from plant roots and stems creates aerobic, hypoxic, and anaerobic environments around the rhizosphere, promoting the collaborative activity of various microorganisms. Root and stem secretions provide carbon sources for microorganisms, influencing their community structure and metabolism, enabling them to remove pollutants from the water through various physiological metabolic pathways. Compared to the absence of plants, the water quality of the receiving water body is significantly improved, with aquatic plants increasing nitrogen removal rates by up to 70%.

[0129] Within the constructed ecosystem, native aquatic animals such as gobies, crucian carp, loach, and clams were introduced. By establishing a food chain of producers, consumers, and restorers, the biodiversity index increased tenfold compared to before the restoration.

[0130] (2) Install high-efficiency aeration and flow-driven water purification equipment based on microbial media in the receiving water body to regulate water quality and improve its stability. Specifically:

[0131] A "high-efficiency aeration and propulsion water purification device based on microbial media" was installed inside the Yezhoujia River. This highly efficient integrated device combines photocatalysis, microbial media, and aeration and propulsion equipment to rapidly increase the dissolved oxygen content of the water and specifically increase the number and activity of microorganisms. During the rainy season, the receiving water body is characterized by large fluctuations in water level and quality, strong biodegradability, and weak flow. The purification device can enhance the self-purification capacity of the water body, achieve comprehensive and multi-level water quality improvement, and ensure that the water quality of the receiving water body is stable and meets standards in a long-term guaranteed state, so as to ensure that the seasonal drainage of the area does not affect the water quality of the surrounding water system.

[0132] The equipment employs directional flow propulsion and microporous high-efficiency oxygenation, achieving an oxygenation efficiency of 6 kg / kW·h. This enables comprehensive optimization of water quality in natural water bodies at different depths, resolving water quality deterioration within 3-5 days. The photocatalytic material utilizes a series of mesoporous materials such as Fe2O3 / Ti-MCM-41, with a specific surface area greater than 800.0 m². 2 / g, under visible light (λ>420nm) irradiation, through complex physical, chemical and biological processes, achieves a degradation rate of over 80% for macromolecular organic pollutants in water, realizing the synergistic treatment of water pollutants and improving water purification efficiency.

[0133] The multi-element solidified microbial carrier is primarily made from byproducts of biomass power generation, such as agricultural and forestry straw. It is processed through high-temperature (700-1000℃) calcination, crushing, sieving, modification, and molding. Its main components are more than ten minerals and trace elements, including silicon, aluminum, calcium, iron, magnesium, sodium, titanium, and manganese, along with a small amount of unburned carbon. It appears as irregular particles, grayish-black in color, with a rough, porous surface, high porosity, and weak alkalinity. It exhibits good physical adsorption and chemical complexation of low-concentration phosphates and facilitates microbial attachment and growth, effectively preventing microbial loss and poisoning, and controlling algal blooms. After one month, the bacterial community of the biofilm carrier was analyzed. At the phylum level, phyla with a relative abundance of less than 1% were merged into others. When the similarity was 97%, the bacterial community distribution of the carrier biofilm was as follows: Figure 11 As shown, the main bacterial groups are Proteobacteria, Actinobacteria, Bacteroidetes, Chloroflexi, and Planctomycetes, with Proteobacteria accounting for 46.91%–68.67% and Actinobacteria accounting for 3.47%–12.62%.

[0134] The overall effect of applying this embodiment is as follows:

[0135] (1) During the experiment, the influent NH3-N concentration in the ecological ditch ranged from 4.3 to 17.8 mg / L, with an average influent concentration of 9.3 mg / L; the effluent concentration ranged from 0.9 to 6.1 mg / L, with an average effluent concentration of 3.06 mg / L. The average removal rate was 67.83%, and the removal rate reached 80% after the later treatment effect stabilized. The modified zeolite and water-steel slag mixed filler in the ecological ditch interception system showed good removal effect on NH3-N in the raw water. In the early stage of the experiment, the removal rate of NH3-N reached more than 40%, and the removal effect of NH3-N was as follows: Figure 12 As shown.

[0136] (2) The ecological ditch interception system has a buffering and purifying effect on urban agricultural non-point source pollution. Within 10 days after fertilization, the nutrient concentration in the ecological ditch and receiving water body is significantly lower than that in the production area. The water quality status and removal rate at the outlet after the implementation of the ecological treatment method for agricultural non-point source pollution are shown in Table 3. Through the connection and coordination of processes such as the ecological ditch interception system, the newly built ecological ditch system, and the end-of-pipe natural purification system, linkage is achieved in terms of time continuity and spatial control, controlling the intercepted water volume to about 78% of the drainage volume. It can significantly reduce the output of nutrients in the field. During the plant growing season, it can reduce the field nitrogen load by about 42%, and the final drainage TN in the ecological planting area is maintained below 2.0 mg / L; the removal efficiency of TP is about 25%, the regional concentration decreases slightly, and the overall water quality is greatly improved.

[0137] Table 3

[0138]

[0139] (3) The design scheme for agricultural non-point source pollution control fully considers the integration of various technologies and spatial correlation of engineering contents in the ecological ditch interception system and the newly constructed ecological ditch system to achieve the removal and purification of agricultural non-point source pollution. The end-of-pipe natural purification system minimizes the harm of agricultural non-point source pollution to the receiving water body through ecosystem construction. In the later stage of the experiment, the NH3-N index of the receiving water body met the Class V standard (<2.0mg / L) of the "Surface Water Environmental Quality Standard" (GB3838-2002), ensuring the recycling of water resources in the later stage. The comparative analysis of the limit values ​​of the five categories of standard indicators in the "Surface Water Environmental Quality Standard" (GB3838-2002) is shown in Table 4.

[0140] Table 4

[0141]

[0142] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A typical urban agriculture non-point source pollution ecological management method, characterized in that, Specifically comprising the following steps: The effluent of the pollution source area is intercepted and purified near the source to obtain a preliminary treatment target; The preliminary treatment target is subjected to secondary interception and purification by an ecological ditch to form a middle section treatment target, wherein the middle section treatment target flows into a receiving water body; An ecological purification system is constructed in the middle section treatment target for terminal purification to obtain a final treatment target; The effluent of the pollution source area is intercepted and purified near the source to obtain a preliminary treatment target, which comprises: Screening a pollution source area of an initial ditch; According to the pollution discharge position of the pollution source area, a nine-square purification grid is used for preliminary interception and purification of the initial ditch; According to the drainage direction, a stepped ecological purification grid and an in-situ sedimentation-promoting purification device are arranged; Based on the stepped ecological purification grid and the in-situ sedimentation-promoting purification device, the effluent of the pollution source area is intercepted and purified in sequence to obtain the preliminary treatment target; The preliminary treatment target is subjected to secondary interception and purification by an ecological ditch to form a middle section treatment target, which comprises: According to the drainage direction, the existing ditch is cleaned and an ecological ditch is constructed; On the basis that the ecological ditch meets the target drainage requirement, the ditch wall and shoulder of the existing ditch are re-greened, the ditch bottom is filled with filter material and aquatic plants are planted, thereby the preliminary treatment target is subjected to secondary interception and purification to form the middle section treatment target; An ecological purification system is constructed in the middle section treatment target for terminal purification to obtain the final treatment target, which comprises: The ecological purification system is established in the middle section treatment target, and combined with micro-ecological regulation technology, agricultural pollutants in the middle section treatment target are reduced; A water quality purification device is arranged to control the dissolved oxygen content, the number of microorganisms and the activity of the receiving water body by the water quality purification device to obtain the final treatment target.

2. A typical urban agriculture non-point source pollution ecological management system, applying the method of claim 1, characterized in that, It comprises: An ecological ditch interception module, an ecological ditch construction module and a natural purification module, and the ecological ditch interception module, the ecological ditch construction module and the natural purification module are arranged in sequence according to the drainage direction; The ecological ditch interception module is used for intercepting and purifying the effluent of the pollution source area near the source to obtain a preliminary treatment target; The ecological ditch construction module is used for subjecting the preliminary treatment target to secondary interception and purification by an ecological ditch to form a middle section treatment target; The natural purification module is used for constructing an ecological purification system in the middle section treatment target for terminal purification to obtain a final treatment target.

3. The typical urban agriculture non-point source pollution ecological management system according to claim 2, characterized in that, The ecological ditch interception module comprises an ecological ditch interception unit and an in-situ sedimentation-promoting purification unit; The ecological ditch interception unit comprises a plurality of nine-square purification grids and a plurality of stepped ecological purification grids, and the nine-square purification grids and the stepped ecological purification grids are arranged in series or in parallel; The in-situ sedimentation-promoting purification unit adopts an in-situ sedimentation-promoting purification device, and a baffle is arranged inside the in-situ sedimentation-promoting purification device. The in-situ promoting sinking and purifying device, the nine-square purifying grid and the ladder-type ecological purifying grid are connected in series, wherein the nine-square purifying grid is filled with ceramsite, volcanic rock composite ore and garden organic medium, and the ladder-type ecological purifying grid is filled with modified zeolite and water steel slag mixed material; the in-situ promoting sinking and purifying device is filled with modified zeolite, water steel slag and biomass filler.

4. The typical urban agriculture non-point source pollution ecological management system of claim 2, wherein, The ecological ditch new module is composed of a drainage ditch main body, a ditch wall, a ditch shoulder, a ditch bottom aquatic plant and a wetland purification unit; The ditch wall and the ditch shoulder are greened by turf, the wetland purification unit is provided with a filler area at every interval target distance along the ditch bottom, the filler area is defined by Chinese fir piles on both sides, and the filler in the filler area is modified zeolite and biomass filler.

5. The typical urban agriculture non-point source pollution ecological management system of claim 2, wherein, The natural purification module includes a natural ecological unit constructed with local dominant species as the core and a water quality purification equipment based on microbial medium arranged in a water resource receiving area, wherein the water quality purification equipment is a high-efficiency aeration plug-flow water quality purification equipment.

6. The typical urban agriculture non-point source pollution ecological management system of claim 5, wherein, The natural ecological unit includes restoration of aquatic plant planting and local aquatic animal community; The aquatic plant includes one or more combinations of Nuphar, Nymphaea, Vallisneria, Hydrilla verticillata, Potamogenton pectinatum and Myriophyllum. The local aquatic animal community includes one or more combinations of Gobiomys, Carassius, Misgurnus, Cyclotella.

7. The typical urban agriculture non-point source pollution ecological management system of claim 5, wherein, The high-efficiency aeration plug-flow water quality purification equipment includes a directional plug-flow and micropore high-efficiency oxygenation subunit, a photocatalytic degradation subunit and a multi-element solidified microbial carrier; The directional plug-flow and micropore high-efficiency oxygenation subunit uses a micro-nano aeration device, the photocatalytic degradation subunit is loaded with a photocatalytic material, and the multi-element solidified microbial carrier is processed by several processes using the by-products of biomass power generation.

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