Plant-biochar-synergistic oxygen-enriched artificial wetland water distribution system and use method

Abstract

The present invention discloses a plant-biochar-synergistic oxygen-enriched artificial wetland water distribution system and a use method, which are applied to the technical field of artificial wetlands. The system comprises emergent plants, a substrate layer and biochar, wherein the substrate layer is a soil layer mixed with biochar, the roots of the emergent plants are placed in the substrate layer, and the top of the substrate layer is a water layer of the wetland; the use method comprises vertical infiltration through the substrate layer downward into a fast infiltration layer, lateral infiltration through a permeable reaction wall and overflow from the top of the permeable reaction wall; the system and the use method can synergistically enhance the oxygen enrichment of the artificial wetland through plants and biochar, effectively improve the reducing environment inside the wetland and the local hypoxic or anaerobic environment, and at the same time can significantly improve the purification effect of the artificial wetland on pollutants, and can provide a variety of water flow modes to overcome the uncertainty of hydraulic load and meet various wetland environments and conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of artificial wetlands, and in particular to a water distribution system and a use method of an artificial wetland based on plant-biochar coordinated oxygen-enriched water. Background Art

[0002] As a high-efficiency and low-energy sewage treatment process, artificial wetlands are widely used in decentralized sewage treatment due to their low investment, stable pollutant purification efficiency, convenient operation and maintenance, and green environmental protection. It is mainly composed of water, matrix, plants, animals, microorganisms, etc. It is a kind of sewage purification treatment that uses physical, chemical, and biological synergy. Dissolved oxygen is one of the most important control conditions in the entire wetland reaction system, which largely determines the sanitary conditions, microbial species, and effluent quality of the wetland system. Due to different water distribution methods, the wetland will present aerobic, anoxic, and anaerobic states. The difference in dissolved oxygen content will greatly affect the treatment efficiency of artificial wetlands. The natural reoxygenation of artificial wetlands usually makes the dissolved oxygen less than 2 mg / L, and the pollutant removal rate is low. Existing studies have shown that when the dissolved oxygen concentration is 2 mg / L, the removal rates of COD, TN, and TP are 31.23%, 8.32%, and 47.16%, respectively. Therefore, the water distribution method in artificial wetlands becomes very important.

[0003] Under natural conditions, oxygen in wetlands mainly comes from the following sources: 1. Oxygen carried by incoming water; 2. Reoxygenation of the atmosphere; 3. Oxygen produced by photosynthesis of plants above the water surface; 4. Oxygen released to the root zone by photosynthesis of plants and rhizosphere plants below the water surface. Common ways to increase dissolved oxygen include strengthening oxygen supply, changing the operation mode, and selectively planting plants. At present, more and more urban landscape water treatment or runoff pollution control technologies at home and abroad tend to adopt a series of ecological treatment technologies combined with landscape improvement. Artificial wetlands belong to ecological treatment technologies. Plants in wetland systems rely on their own metabolic functions to purify water bodies while releasing oxygen, improving the oxygen environment of wetland systems, and paying more attention to the ecological cycle effect that relies on the "natural purification system". This trend weakens the artificial strengthening process and focuses on ecological recycling. Therefore, compared with conventional sewage treatment technologies, the control of dissolved oxygen is often overlooked in the actual engineering application of artificial wetlands.

[0004] The oxygen released by plants cannot fully meet the needs of wetland systems. Due to the low diffusion of oxygen, the dissolved oxygen is at a low level for a long time. Under such conditions, microorganisms will choose special electron donors to oxidize organic matter. These special electron donors will cause toxic effects on plants after losing electrons. In addition, when plants are in an oxygen-deficient or even anaerobic environment for a long time, the strong reducing ion Fe 2+ and Mn 2+ O will be formed in the plant 2- and H 2 O2 Toxic byproducts such as chlorinated bisulfite can cause damage such as membrane lipid peroxidation and protein and DNA damage.

[0005] Artificial wetlands with existing technologies cannot effectively improve the reducing environment and local hypoxic or anaerobic environment inside the wetlands, and will cause toxicity and damage to aquatic plants. Although artificial wetlands also use biochar, the use of biochar is for the filtration process / direct purification of pollutants, and the removal effect of pollutants is improved by filtration. However, in the case of limited volume of biochar, its filtration effect is limited and it cannot achieve efficient removal of pollutants. Summary of the invention

[0006] The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art that cannot effectively improve the hypoxic environment of the wetland, and to provide a plant-biochar synergistic oxygen-enriched artificial wetland water distribution system and a method of use, which can synergistically enhance the oxygen enrichment of the artificial wetland through plants and biochar, effectively improve the reducing environment and local hypoxic or anaerobic environment inside the wetland, and at the same time achieve efficient removal of organic pollutants, nitrogen, phosphorus, etc., significantly improving the purification effect of artificial wetlands on pollutants.

[0007] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0008] Based on the plant-biochar synergistic oxygen-enriched artificial wetland water distribution system, it includes emergent plants, a substrate layer and biochar, the substrate layer is a soil layer mixed with biochar, the roots of the emergent plants are placed in the substrate layer, and the top of the substrate layer is the water layer of the wetland; the water body is oxygenated by the photosynthesis and respiration of the emergent plants, thereby increasing the dissolved oxygen concentration of the influent; under the condition of low hydraulic load, due to less reoxygenation of the influent, atmospheric reoxygenation cannot meet the requirements of the dissolved oxygen concentration, and the use of emergent plants can supplement the reoxygenation of the water body, and the removal rate of pollutants in the wetland increases with the increase of dissolved oxygen concentration, thereby improving the removal rate of pollutants; conventional biochar in artificial wetlands is used in the filtration / purification stage, and this scheme innovatively uses biochar as a substrate layer for planting emergent plants. On the one hand, due to the high porosity and large specific surface area of ​​biochar, it is conducive to the retention and diffusion of oxygen, which is conducive to the nutrients required by aerobic microorganisms. At the same time, biochar can be used as an adsorbent and has good adsorption for organic matter, ammonia nitrogen, etc. in the water body. On the other hand, the addition of biochar is conducive to the formation of root ventilation structure of plants and increases root porosity, which is conducive to the diffusion of oxygen in the system, prompting oxygen to be transmitted to the underground part through the aerenchyma and diffused to the rhizosphere in the form of root oxygen secretion, significantly improving the reoxygenation capacity of artificial wetlands. At the same time, biochar can also provide a carbon source for sewage nitrification and denitrification, and then the dissolved oxygen content of the influent can be further increased through biochar, and the removal rate of pollutants can be improved; the above system can make the dissolved oxygen concentration in the water body greater than 6 mg / L, which is more than 150% higher than that of conventional artificial wetlands, and can further improve the removal rate of pollutants. For example, after the above system is used, the dissolved oxygen concentration is 6 mg / L, and the removal rates of COD, TN and TP are 69.32%, 66.39% and 68.48% respectively. Compared with the natural reoxygenation of existing artificial wetlands, pollutants can be removed more efficiently.

[0009] In a preferred embodiment of the present invention, the mass ratio of biochar in the above-mentioned matrix layer is 0.8-1.2%. Since the addition of biochar will cause irreversible effects on soil properties, the use of biochar in the above-mentioned ratio mixed in the matrix layer has less irreversible effects on soil properties and can maintain the physical and chemical properties of the soil.

[0010] In a preferred embodiment of the present invention, the above-mentioned biochar is made of at least one of rice straw, rape straw, wheat, corn or animal manure; by adopting the above-mentioned substrate to be produced by high-temperature pyrolysis under low-oxygen or anoxic conditions, agricultural waste can be utilized, local materials can be obtained, the cost of artificial wetland transformation is saved, and the requirements of environmental protection and economy are met.

[0011] In a preferred embodiment of the present invention, the height of the above-mentioned substrate layer is 15 to 20 cm; if the height of the substrate layer is too high, it may cause the infiltration speed to be too slow or even blockage, and if the height of the substrate layer is too low, it cannot provide a growth environment for emergent plants. The setting of the height of the above-mentioned substrate layer can meet the water depth suitable for the production of emergent plants, and at the same time has the infiltration function.

[0012] In a preferred embodiment of the present invention, the above-mentioned emergent plants include reed, cattail, water chestnut, lotus, water celery, arrowroot, wild rice stem, lotus or cattail; by selecting emergent plants, preferably those with stronger metabolism, they can produce more water oxygen through photosynthesis and respiration, thereby further increasing the dissolved oxygen concentration of the inlet water.

[0013] In a preferred embodiment of the present invention, the soil in the above-mentioned soil layer is purple soil; since purple soil is rich in nutrients such as phosphorus and potassium, by selecting purple soil, it can provide nutrients for the growth of emergent plants. At the same time, the purple soil is loose and has a certain permeability, which is convenient for the penetration of sewage.

[0014] In a preferred embodiment of the present invention, the artificial wetland water distribution system also includes a rapid infiltration layer, which is arranged in the lower layer of the matrix layer. The rapid infiltration layer is filled with gravel with particle sizes of 2-4 mm, 1.5-2 cm, 2-3 cm, and 3-5 cm, and the height of the rapid infiltration layer is 10-15 cm. By selecting the particle size of the gravel, sewage can be quickly infiltrated without clogging, ensuring smooth water discharge. If the height of the rapid infiltration layer is too low, the effect of rapid infiltration and water passage cannot be achieved, and if the height is too low, consumables and economic costs are increased. The above height setting can be comprehensively considered and optimized.

[0015] In a preferred embodiment of the present invention, the artificial wetland water distribution system further comprises a permeable reaction wall, which is a soil plate layer mixed with 4-6% biochar by mass, and the permeable reaction wall is arranged on both sides of the top of the matrix layer, and the height of the permeable reaction wall is 10-15 cm; biochar is a carbon-rich product formed by pyrolysis of waste biomass under oxygen-limited conditions, and its ash elements (such as K, Ca, Mg, phosphorus, etc.) are rich in content, which can be used as soluble nutrients by plants, and promote the growth of wetland plants by storing nutrient elements, improving wetland matrix, etc., and by adding biochar in the above proportion, the mineral element content in the soil can be effectively provided for absorption and utilization by emergent plants, and certain soil physical and chemical properties can be maintained. At the same time, due to the adsorption effect of biochar itself, it can have filtering and purification functions like other artificial wetlands; the higher the height or proportion of biochar added in the permeable reaction wall, the more biochar is required, which will result in higher economic costs, and the height setting of the permeable reaction wall can take into account economic benefits on the basis of providing the above functional effects.

[0016] In a preferred embodiment of the present invention, the above-mentioned artificial wetland water distribution system is formed by a repeated arrangement of several groups of units, each group of units includes at least a matrix layer and a rapid infiltration layer, and the matrix layers of adjacent units are spaced apart from each other; compared with the existing artificial wetlands that require manual maintenance such as maintenance of inlet and outlet pipes, wetland plant management, and removal of weeds and debris, this system can combine the terrain to form natural gravity flow conditions, automatically complete the functions of artificial wetlands, keep the water body oxygen-rich and improve the pollutant removal rate, reducing manual maintenance costs.

[0017] The method for using the plant-biochar-coordinated oxygen-enriched artificial wetland water distribution system adopts the above-mentioned plant-biochar-coordinated oxygen-enriched artificial wetland water distribution system, and the method for using includes:

[0018] The water entering the artificial wetland water distribution system penetrates vertically through the matrix layer and enters the rapid infiltration layer for water distribution;

[0019] When a permeable reaction wall is used, the water entering the artificial wetland water distribution system is distributed through two methods: vertical infiltration and lateral infiltration. Vertical infiltration is to enter the fast infiltration layer through the matrix layer downward, and lateral infiltration is to flow out through the permeable reaction wall laterally.

[0020] Or when a permeable reaction wall is used, the water entering the artificial wetland water distribution system is distributed through three methods: vertical infiltration, lateral infiltration and waterfall overflow. Vertical infiltration is the water distribution from the matrix layer downward into the rapid infiltration layer, lateral infiltration is the water distribution flowing laterally through the permeable reaction wall, and waterfall overflow is the water distribution overflowing from the top of the permeable reaction wall and falling to the rapid infiltration layer.

[0021] Affected by factors such as season, time period, and living habits, the water inflow of artificial wetlands varies greatly during the period. When the water inflow is low, large, and extremely large, different methods of use can be provided. Through vertical infiltration, lateral infiltration, and waterfall overflow, different sewage flow states and water distribution are provided, which are suitable for different water inflow conditions. It can effectively overcome the uncertainty of sewage hydraulic load and meet various wetland environments and conditions.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The system selects soil, biochar and gravel as the main substrates to construct a water distribution system. The system uses a substrate layer composed of a low proportion of biochar as the emergent plant, and a permeable reaction wall with a higher proportion of biochar. The sewage flow is guided through a fast penetration layer composed of gravel. The selection of emergent plants and biochar increases the dissolved oxygen content of the influent, effectively improving the reducing environment and local hypoxic or anaerobic environment inside the wetland. At the same time, it can achieve efficient removal of organic pollutants, nitrogen, phosphorus, etc., significantly improving the purification effect of artificial wetlands on pollutants, and providing an oxygen-rich artificial wetland water distribution system synergistically enhanced by plants and biochar.

[0024] 2. The system uses agricultural waste and raw soil, and uses local materials to reduce construction costs. Compared with existing artificial wetlands that require manual maintenance such as water inlet and outlet pipe maintenance, wetland plant management, and removal of weeds and debris, the system can combine the terrain to form natural gravity flow conditions, automatically complete the functions of artificial wetlands, keep the water body oxygen-rich and improve the pollutant removal rate, reducing manual maintenance costs.

[0025] 3. This method of use provides different sewage flow states and water distribution through three modes: vertical infiltration, lateral infiltration and waterfall overflow. It is suitable for different water inflow conditions, can effectively overcome the uncertainty of sewage hydraulic load, and meet various wetland environments and conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Each unit of the plant-biochar synergistic oxygen-enriched artificial wetland water distribution system of the present invention is composed of;

[0027] Figure 2 It is a schematic diagram of the water distribution system of plant-biochar synergistic oxygen-enriched artificial wetland according to the present invention;

[0028] Figure 3 The oxygen content test results of the water body based on the plant-biochar synergistic oxygen-enriched artificial wetland water distribution system of the present invention;

[0029] Figure 4 This is another embodiment of the plant-biochar synergistic oxygen-enriched artificial wetland water distribution system of the present invention;

[0030] Labels in the figure: 1-emergent plants; 2-matrix layer; 3-rapid infiltration layer; 4-permeable reaction wall. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below in conjunction with test examples and specific implementation methods. However, this should not be understood as the scope of the above subject matter of the present invention being limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0032] Example 1

[0033] Please refer to Figure 1 and Figure 2 The present embodiment provides a plant-biochar synergistic oxygen-enriched artificial wetland water distribution system, the system includes emergent plants 1, a matrix layer 2, a fast permeation layer 3, a permeable reaction wall 4 and biochar, wherein the matrix layer 2 and the permeable reaction wall 4 are respectively mixed with biochar, the system as a whole is three layers, the lower layer is the fast permeation layer 3, the middle layer is formed by the matrix layer 2 being arranged at intervals, the upper layer is the water layer, the permeable reaction wall 4 is arranged on the top of the matrix layer 2, the permeable reaction wall 4, the matrix layer 2 and part of the fast permeation layer 3 are used as a group of units, and the system is formed by a plurality of groups of units being arranged in a repeated manner, and the matrix layers 2 of adjacent units are spaced from each other; the system can increase the dissolved oxygen content of the influent, effectively improve the reducing environment inside the wetland and the local hypoxic or anaerobic environment, and at the same time can achieve efficient removal of organic pollutants, nitrogen, phosphorus, etc., significantly improve the purification effect of artificial wetlands on pollutants, and provide a plant-biochar synergistically enhanced oxygen-enriched artificial wetland water distribution system.

[0034] In this embodiment, biochar is used. Both the matrix layer 2 and the rapid permeation layer 3 are mixed with biochar, and the proportions of the biochar mixed in the two are different. The biochar is made of at least one of rice straw, rape straw, wheat, corn or animal manure. The biochar in this embodiment is formed by high-temperature pyrolysis of rice straw and rape straw under low oxygen and anoxic conditions. The production of biochar can utilize agricultural waste and local materials, saving the cost of artificial wetland transformation and meeting the requirements of environmental protection and economy. This embodiment utilizes the properties of biochar. Different from the existing artificial wetlands that use biochar as an adsorbent for filtration / purification stages, this embodiment innovatively uses biochar as a component of the matrix layer 2 for planting emergent plants 1. On the one hand, due to the high porosity and large specific surface area of ​​biochar, it is beneficial to The retention and diffusion of oxygen is beneficial to the nutrients required by aerobic microorganisms. At the same time, biochar can act as an adsorbent and has good adsorption properties for organic matter, ammonia nitrogen, etc. in water bodies, reducing the content of ammonia nitrogen, phosphate, etc. in sewage and converting them into elements required for plant growth. On the other hand, the addition of biochar is beneficial to the formation of root ventilation structure for plants and increases root porosity, which is beneficial to the diffusion of oxygen in the system, prompting oxygen to be transmitted to the underground part through the aerenchyma and diffuse to the rhizosphere in the form of root oxygen secretion, significantly improving the reoxygenation capacity of artificial wetlands. At the same time, biochar can also provide a carbon source for sewage nitrification and denitrification, and then the dissolved oxygen content of the influent can be further increased through biochar. Since the removal rate of pollutants in wetlands increases with the increase of dissolved oxygen concentration, the removal rate of pollutants is further improved.

[0035] In this embodiment, the upper layer of the rapid permeation layer 3 is a plurality of matrix layers 2, and adjacent matrix layers 2 are spaced apart from each other. In this embodiment, they are arranged at equal intervals, and the matrix layers 2 are arranged in strips, so that the matrix layers 2 are arranged in strips spaced apart from each other on the top of the rapid permeation layer 3. The matrix layer 2 is a soil layer mixed with biochar, and the soil layer is a plant root growth area filled with soil as a base layer. The optional range of the mass ratio of biochar in the matrix layer 2 is 0.8-1.2%. In this embodiment, a 1% mass ratio of biochar is used. The low proportion of biochar is used because the addition of biochar will have an irreversible effect on the properties of the soil, and the use of 1% biochar mixed in the matrix layer 2 has a smaller irreversible effect on the properties of the soil, and can maintain the physical and chemical properties of the soil. The optional height range of the substrate layer 2 is 15 to 20 cm. The height of the substrate layer 2 in this embodiment is 18 cm. The height of the substrate layer 2 should be neither too high nor too low. If the height of the substrate layer 2 is too high, it may cause the infiltration speed to be too slow or even blocked. If the height of the substrate layer 2 is too low, it cannot provide a growth environment for the emergent plants 1. The height setting of the substrate layer 2 in this embodiment can meet the water depth suitable for the production of the emergent plants 1, and at the same time has the infiltration function.

[0036] In this embodiment, the main component of the matrix layer 2 is soil, which can be red soil, black soil, sandy soil, etc. It is necessary to ensure that the selected soil can provide a nutrient environment for the growth of the emergent plant 1 and has a certain permeability. The soil used in this embodiment is purple soil, which can provide nutrients such as phosphorus and potassium for the emergent plant 1. At the same time, due to the loose soil, it has a certain permeability. The purple soil is mixed with 1% mass ratio of biochar, and the mixed mixture is formed to form a matrix layer 2, and the root system of the emergent plant 1 is placed in the matrix layer 2. The top of the matrix layer 2 is the water layer of the wetland. Part of the emergent plant 1 is located in the water layer, and most of it is exposed on the water surface. There are many options for the emergent plant 1, including reed, cattail, water chestnut, lotus, celery, arrowroot, wild rice, lotus or cattail, and the emergent plant 1 in this embodiment uses regenerated flowers, which belong to the arrowroot class. Under low hydraulic load conditions, due to less reoxygenation of the incoming water, atmospheric reoxygenation cannot meet the requirement for dissolved oxygen concentration. Emergent plants 1 can be used to supplement reoxygenation of the water body. By selecting emergent plants 1, those with stronger metabolism can be selected, which can produce more water oxygen through photosynthesis and respiration, thereby further increasing the dissolved oxygen concentration of the incoming water.

[0037] The top of the substrate layer 2 of the present embodiment is further provided with a permeable reaction wall 4, which is in the shape of a plate. Each substrate layer 2 corresponds to two permeable reaction walls 4, which are located on both sides of the top of the substrate layer 2. The permeable reaction wall 4 should be neither too wide nor too narrow. The thickness of the permeable reaction wall 4 in the present embodiment is 10 to 15 cm of the width of the substrate layer 2, preferably 12 cm. The permeable reaction wall 4 is a soil plate layer mixed with 4 to 6% biochar by mass, and the soil plate layer is a plate-like structure made of soil. The biochar added in the above proportion In addition, it can effectively provide the mineral element content in the soil for the emergent plants 1 to absorb and utilize, and can also maintain certain physical and chemical properties of the soil. At the same time, due to the adsorption effect of the biochar itself, it can have filtering and purification functions like other artificial wetlands; the height of the permeable reaction wall 4 is 10-15cm, preferably 12cm. The higher the height or proportion of biochar added in the permeable reaction wall 4, the more biochar is required, which will result in higher economic costs. The height setting of the above-mentioned permeable reaction wall 4 can take into account economic benefits on the basis of providing the above-mentioned functional effects.

[0038] The rapid infiltration layer 3 of the present embodiment is located in the lower layer of the matrix layer 2. The rapid infiltration layer 3 is filled with gravel with particle sizes of 2-4 mm, 1.5-2 cm, 2-3 cm, and 3-5 cm, respectively. In the present embodiment, gravel with particle sizes of 3 mm, 1.8 cm, 2.5 cm, and 4 cm are mixed and filled to form the rapid infiltration layer 3. The selection and production of gravel for the rapid infiltration layer 3 are similar to the infiltration layer of the existing artificial wetland. By selecting the particle size of the gravel, sewage can be rapidly infiltrated without being blocked, thereby ensuring smooth water discharge. The height of the rapid infiltration layer 3 is 10-15 cm, preferably 12 cm. If the height of the rapid infiltration layer 3 is too low, the effect of rapid infiltration and water passage cannot be achieved. If the height is too low, consumables and economic costs are increased. The height setting of the present embodiment can be comprehensively considered.

[0039] Please refer to Figure 3 By adopting the system of this embodiment, the dissolved oxygen concentration in the water body can be made greater than 6 mg / L, and the highest dissolved oxygen concentration is close to 7 mg / L, which is more than 150% higher than that of conventional artificial wetlands. At the same time, the removal rate of pollutants can be significantly improved. For example, after adopting the above system, the dissolved oxygen concentration is 6 mg / L, and the removal rates of COD, TN, and TP are 69.32%, 66.39%, and 68.48%, respectively. Compared with the natural reoxygenation of existing artificial wetlands, pollutants can be removed more efficiently.

[0040] Example 2

[0041] Please refer to Figure 4This embodiment provides a plant-biochar-coordinated oxygen-enriched artificial wetland water distribution system. Compared with Example 1, the water distribution layered structure of the artificial wetland is different. The system does not have a permeable reaction wall 4, and the setting of the matrix layer 2 is different.

[0042] The system of this embodiment includes an emergent plant 1, a matrix layer 2, a fast permeation layer 3 and biochar. The system includes three layers, an upper layer is a water layer, a middle layer is a matrix layer 2, and a lower layer is a fast permeation layer 3. The water layer is located at the top of the matrix layer 2, and the fast permeation layer 3 is located at the bottom of the matrix layer 2; the matrix layer 2 is a soil layer mixed with biochar, and the root system of the emergent plant 1 is placed in the matrix layer 2. The emergent plant 1 of this embodiment is selected as variegated reed, and the fast permeation layer 3 is composed of gravel of different particle sizes. The matrix layer 2 of this embodiment and the matrix layer 2 in Example 1 are mixed with biochar and black soil at a mass ratio of 1.1%, and the matrix layer 2 and the fast permeation layer 3 both adopt a layered structure, and other settings are the same as the matrix layer 2 and the fast permeation layer 3 in Example 1, such as height setting, gravel particle size selection, etc.

[0043] Example 3

[0044] Please refer to Figure 1 and Figure 4 This embodiment provides a method for using a plant-biochar-cooperative oxygen-enriched artificial wetland water distribution system. The method uses the plant-biochar-cooperative oxygen-enriched artificial wetland water distribution system in Example 1 or Example 2. The method includes:

[0045] The water entering the artificial wetland water distribution system enters the rapid infiltration layer 3 for water distribution through the matrix layer 2 by vertical infiltration. This method of use corresponds to a usage scenario in Example 1. For example, in Example 1, the water inflow of the artificial wetland is low, the depth of the sewage is less than the height of the permeable reaction wall 4, and the sewage enters the matrix layer 2 and the rapid infiltration layer 3 by vertical infiltration. This method of use can also be directly used in Example 2. In Example 2, it is not affected by the water inflow and is always in vertical infiltration.

[0046] When the permeable reaction wall 4 is used, the water entering the artificial wetland water distribution system is distributed through two methods: vertical infiltration and lateral infiltration. The vertical infiltration is to enter the rapid infiltration layer 3 through the matrix layer 2 for distribution, and the lateral infiltration is to flow out laterally through the permeable reaction wall 4 for distribution. This method of use is only for one usage scenario in Example 1. For example, in Example 1, the water inflow of the artificial wetland is large, the depth of the sewage is equivalent to the height of the permeable reaction wall 4, and part of the sewage can obviously penetrate laterally through the permeable reaction wall 4. At the same time, the sewage also enters the matrix layer 2 and the rapid infiltration layer 3 by vertical infiltration. At this time, there are two infiltration methods.

[0047] Or when a permeable reaction wall 4 is used, the water entering the artificial wetland water distribution system is distributed through three methods: vertical infiltration, lateral infiltration and waterfall overflow. Vertical infiltration is the water distribution from the substrate layer 2 downward into the rapid infiltration layer 3, lateral infiltration is the water distribution from the side of the permeable reaction wall 4, and waterfall overflow is the water distribution from the top of the permeable reaction wall 4 to the rapid infiltration layer 3. This method of use is only for one usage scenario in Example 1. For example, in Example 1, the water inflow of the artificial wetland is extremely large, and the sewage cannot be blocked by the permeable reaction wall 4. The sewage can overflow from the top of the permeable reaction wall 4. Part of the sewage can obviously penetrate laterally through the permeable reaction wall 4. The sewage can also overflow from the top of the permeable reaction wall 4 to form an overflow. After the sewage overflows, a waterfall is generated under the height difference. The falling water directly enters the rapid infiltration layer 3. At the same time, the sewage also enters the substrate layer 2 and the rapid infiltration layer 3 through vertical infiltration. At this time, there are three infiltration methods.

[0048] Affected by factors such as season, time period, and living habits, the water inflow of artificial wetlands varies greatly during the period. When the water inflow is low, large, and extremely large, different methods of use can be provided. Through vertical infiltration, lateral infiltration, and waterfall overflow, different sewage flow states and water distribution are provided, which are suitable for different water inflow conditions. It can effectively overcome the uncertainty of sewage hydraulic load and meet various wetland environments and conditions.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. Based on plant-biochar synergistic oxygen-enriched artificial wetland water distribution system, characterized by: It comprises emergent plants, a matrix layer, biochar, a fast permeable layer and a permeable reaction wall, wherein the matrix layer is a soil layer mixed with the biochar, the mass ratio of the biochar in the matrix layer is 0.8-1.2%, the roots of the emergent plants are placed in the matrix layer, the top of the matrix layer is a water layer of the wetland; the height of the matrix layer is 15-20 cm, and the soil in the soil layer is purple soil; The rapid infiltration layer is arranged in the lower layer of the matrix layer, and the rapid infiltration layer is filled with gravel with particle sizes of 2-4 mm, 1.5-2 cm, 2-3 cm, and 3-5 cm, respectively, and the height of the rapid infiltration layer is 10-15 cm; the permeable reaction wall is a soil slab layer mixed with 4-6% biochar by mass, and the permeable reaction wall is arranged on both sides of the top of the matrix layer, and the height of the permeable reaction wall is 10-15 cm.

2. The plant-biochar-coordinated oxygen-enriched artificial wetland water distribution system according to claim 1 is characterized in that: The biochar is made from at least one of rice straw, rape straw, wheat, corn or animal manure.

3. The plant-biochar-coordinated oxygen-enriched artificial wetland water distribution system according to claim 1 is characterized in that: The emergent plants include reed, cattail, water chestnut, lotus, water celery, arrowroot, wild rice stem, lotus or cattail.

4. The plant-biochar-coordinated oxygen-enriched artificial wetland water distribution system according to claim 1 is characterized in that: The system is formed by repeatedly arranging a plurality of groups of units, each group of units at least comprises the matrix layer and the fast permeation layer, and the matrix layers of adjacent units are spaced from each other.

5. A method for using a water distribution system based on plant biochar and oxygen-enriched artificial wetlands, characterized in that: The plant-biochar-coordinated oxygen-enriched artificial wetland water distribution system according to claim 4 is used, and the method of use includes: The water entering the artificial wetland water distribution system penetrates vertically through the matrix layer and enters the rapid infiltration layer for water distribution; When a permeable reaction wall is used, the water entering the artificial wetland water distribution system is distributed through two methods: vertical infiltration and lateral infiltration. Vertical infiltration is to enter the fast infiltration layer through the matrix layer downward, and lateral infiltration is to flow out through the permeable reaction wall laterally. Or when a permeable reaction wall is used, the water entering the artificial wetland water distribution system is distributed through three methods: vertical infiltration, lateral infiltration and waterfall overflow. Vertical infiltration is the water distribution from the matrix layer downward into the rapid infiltration layer, lateral infiltration is the water distribution flowing laterally through the permeable reaction wall, and waterfall overflow is the water distribution overflowing from the top of the permeable reaction wall and falling to the rapid infiltration layer.

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