Wetland buffer system based on polyhydroxyalkanoate-induced denitrifier system

Abstract

This invention belongs to the field of aquatic ecological restoration technology, specifically relating to a wetland buffer zone system based on a polyhydroxyalkanoate-induced denitrifying bacteria system. The system includes: a wetland buffer zone substrate with a sloping top surface; several emergent plants planted on the slope of the substrate; a denitrifying bacteria system comprising several polyhydroxyalkanoate strips embedded in the substrate; and several partitions with mesh openings embedded in the substrate. The slow-release properties of the polyhydroxyalkanoate and the periodic metabolism of the emergent plants ensure the long-term activity of the denitrifying bacteria, while the structural partitions ensure the system's stability under complex hydraulic conditions. This invention combines the advantages of efficient nitrogen removal, ecological restoration, and low maintenance costs, making it suitable for river and lake buffer zones, constructed wetlands, and other similar applications.

Description

Technical Field

[0001] This utility model belongs to the field of water ecological restoration technology, specifically relating to a wetland buffer zone system based on a polyhydroxyalkanoate-induced denitrifying bacteria system. Background Technology

[0002] With the accelerated pace of industrialization and urbanization, eutrophication of water bodies is becoming increasingly serious, with nitrogen pollution being particularly prominent. Studies have shown that wetland buffer zones, as important ecological purification systems, can effectively absorb, filter, and degrade water pollutants through the synergistic effects of vegetation, soil, and microorganisms. However, when treating water bodies with high concentrations of nitrogen pollution, traditional wetland buffer zone systems generally face bottlenecks such as insufficient denitrification and low nitrogen removal efficiency. This is mainly attributed to the fact that the denitrification process requires sufficient organic carbon as an electron donor, while the influent carbon-to-nitrogen ratio (C:N) is often low in actual operation, leading to intense competition for carbon sources within the system and limiting the activity of denitrifying bacteria. For example, data from a study on the restoration of the Dianchi Lake shoreline showed that with the supplementation of exogenous carbon, the system's denitrification rate significantly increased (from 0.19 mg N / L·h to 0.39 mg N / L·h), confirming that natural organic carbon sources are insufficient to meet the requirements for efficient nitrogen removal. Especially in the treatment of water bodies with low C:N ratios, such as those from rural non-point source pollution, carbon scarcity has become a key factor restricting the nitrogen removal efficiency of traditional wetland systems. Therefore, optimizing carbon source supply strategies and improving denitrification efficiency are important innovative directions for enhancing the nitrogen removal capacity of wetland buffer zones.

[0003] To enhance the denitrification efficiency of wetland buffer zones, existing technologies primarily focus on vegetation regulation, hydrological condition optimization, and carbon source supplementation. Vegetation regulation involves selecting highly efficient nitrogen-depleting plants (such as sweet flag and canna lily) and optimizing vegetation cover to enhance root microbial activity and promote nitrogen conversion. Hydrological condition regulation includes restoring hydrological connectivity and implementing alternating wet and dry management to improve the anaerobic environment and increase the denitrification rate. Carbon source supplementation strategies address the carbon scarcity problem in water bodies with low C:N ratios by adding organic carbon (such as glucose) or utilizing sulfur autotrophic denitrification, providing sufficient electron donors for denitrification. Furthermore, optimizing environmental factors (such as controlling dissolved oxygen, temperature, salinity, and pH) can create suitable denitrification conditions. In summary, the core of these measures lies in maximizing denitrification efficiency through systematic regulation, constructing an anaerobic environment, ensuring carbon source supply, and optimizing environmental parameters, combined with the ecological characteristics of wetland buffer zones.

[0004] In wetland buffer zone systems, the addition of exogenous carbon sources can effectively promote microbial denitrification. Currently, glucose is a commonly used carbon source. Due to its small molecule solubility, it is easily utilized directly by denitrifying bacteria, significantly increasing the denitrification rate in a short period. However, the rapid consumption of glucose may lead to frequent additions, and its excessive use can easily cause secondary pollution problems such as excessive proliferation of heterotrophic bacteria and increased chemical oxygen demand (COD). In addition, the structural characteristics of wetland buffer zones limit the feasibility of continuous glucose addition, which may lead to insufficient local concentrations or overall loss, making it difficult to maintain an effective concentration in a specific area.

[0005] Therefore, developing a carbon source that can be slowly released in wetland systems, avoids increasing COD in the water, and has a long-lasting effect has become a key requirement. Such a carbon source should have stable release characteristics, which can meet the long-term energy needs of denitrifying bacteria and maintain the quality of the water environment, thereby achieving a sustained and stable denitrification effect in the wetland buffer zone. Utility Model Content

[0006] The present invention addresses the aforementioned technical problems by providing a wetland buffer zone system based on a polyhydroxyalkanoate-induced denitrifying bacteria system.

[0007] A wetland buffer zone system based on a polyhydroxyalkanoate-induced denitrifying bacteria system, the wetland buffer zone system comprising:

[0008] The wetland buffer zone base has a sloping top surface.

[0009] Several emergent aquatic plants were planted on the slope of the wetland buffer zone substrate.

[0010] The denitrifying bacteria system employs several polyhydroxyalkanoate strips made of polyhydroxyalkanoate material, with the polyhydroxyalkanoate strips respectively embedded in the wetland buffer zone substrate;

[0011] Several partitions, each with a mesh, are embedded in the wetland buffer zone substrate.

[0012] Optionally, the slope angle of the wetland buffer zone substrate is between 2° and 30°.

[0013] Optionally, the matrix in the wetland buffer zone is a mixture of one or more materials selected from soil, gravel, crushed stone, fly ash, ceramsite, and coal slag.

[0014] Optionally, the matrix particle size in the wetland buffer zone matrix is ​​between 1 cm and 3 cm.

[0015] Optionally, the emergent plant may be one or more of the following: loosestrife, burdock, canna lily, thaliana, and variegated reed.

[0016] Optionally, the length direction of the polyhydroxyalkanoate strip is consistent with the length direction of the wetland buffer zone substrate, and the polyhydroxyalkanoate strip is inclinedly disposed inside the wetland buffer zone substrate and has the same slope angle as the wetland buffer zone substrate.

[0017] Optionally, the wetland buffer zone substrate is provided with a number of vertical partitions, which divide the interior of the wetland buffer zone substrate into a number of relatively independent working areas. Each working area is provided with a number of denitrifying bacteria systems distributed vertically, and the denitrifying bacteria systems in adjacent working areas are staggered or adjacent.

[0018] Optionally, the vertical partitions are connected to the wetland buffer zone substrate via a detachable guide rail mechanism, allowing each vertical partition to be pulled out and replaced in the vertical direction.

[0019] The wetland buffer zone system is configured with partition replacement cycle parameters corresponding to each working area. When the preset time threshold corresponding to the partition replacement cycle parameter is reached, the corresponding vertical partition is replaced as a whole and the denitrifying bacteria system is dynamically updated by pulling it out.

[0020] Optionally, the wetland buffer zone substrate is provided with a plurality of vertical partitions inside, and the slope of the wetland buffer zone substrate is provided with inclined partitions. The inclined partitions, the plurality of vertical partitions, and the plurality of denitrifying bacteria systems divide the wetland buffer zone system into a pretreatment zone with emergent plants, a denitrification zone with denitrifying bacteria systems, and a stabilization zone.

[0021] Optionally, the tilt angle of the inclined partition is consistent with the slope angle.

[0022] Optionally, the mesh size is 1cm x 1cm.

[0023] Optionally, the partition is fixed using a steel structure mesh.

[0024] Optionally, the partition plate is anchored to the wetland buffer zone substrate.

[0025] Beneficial Effects: This invention has at least one or more of the following advantages: By coupling the wetland buffer zone substrate with the slope topography, this invention guides water flow sequentially through the interception layer of emergent plants, the PHA denitrifying bacteria activity zone of the denitrifying bacteria system, and the fixed baffle stabilization zone, forming a multi-stage purification path of "physical interception—biological denitrification—structural reinforcement." The slow-release characteristics of PHAs and the periodic metabolism of emergent plants jointly ensure the long-term activity of denitrifying bacteria, while the structural baffles ensure the stability of the system under complex hydraulic conditions. This invention combines the advantages of efficient denitrification, ecological restoration, and low maintenance costs, and is suitable for scenarios such as river and lake buffer zones and constructed wetlands. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of one structure of the present utility model. Detailed Implementation

[0027] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, so as to better understand the purpose, features and advantages of the present invention. It should be understood that the embodiments shown in the drawings are not intended to limit the scope of the present invention, but are only for illustrating the essential spirit of the technical solution of the present invention.

[0028] In the following description, certain specific details are set forth for the purpose of illustrating various disclosed embodiments in order to provide a thorough understanding of the various disclosed embodiments. However, those skilled in the art will recognize that embodiments may be practiced without one or more of these specific details. In other instances, well-known apparatuses, structures, and techniques associated with this application may not have been shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.

[0029] Throughout this specification, references to "an embodiment" or "an embodiment" indicate that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Therefore, the appearance of "in an embodiment" or "an embodiment" in various places throughout the specification does not necessarily refer to the same embodiment. Furthermore, a particular feature, structure, or characteristic may be combined in any manner in one or more embodiments.

[0030] In the following description, in order to clearly demonstrate the structure and working method of this utility model, a number of directional terms will be used. However, terms such as "front", "back", "left", "right", "outside", "inside", "outward", "inward", "up", and "down" should be understood as convenient terms and not as limiting terms.

[0031] This invention provides a wetland buffer zone system based on a polyhydroxyalkanoate-induced denitrifying bacteria system. This system overcomes the biological nitrogen removal bottlenecks of traditional systems caused by substrate limitations and low carbon source metabolism efficiency in denitrifying bacteria communities. It focuses on solving core problems such as low utilization of liquid carbon sources, poor feasibility of continuous addition, and secondary COD pollution. Through the gradient release characteristics of PHAs, it achieves precise control of denitrification electron donors. Combined with adaptive optimization of the bacterial metabolic network, it significantly improves the bioconversion efficiency of nitrate to nitrogen. Ultimately, it achieves in-situ enhancement of the denitrification function of the wetland buffer zone system under low C / N ratio conditions, simultaneously improving the system's resistance to load shocks and long-term operational stability.

[0032] Reference Figure 1 The wetland buffer zone system includes a wetland buffer zone substrate 10, several emergent plants 20, a denitrifying bacteria system, and several partitions 40. The denitrifying bacteria system utilizes several polyhydroxyalkanoate strips 30.

[0033] The top surface of the wetland buffer zone substrate 10 is a slope 10a, causing the wetland buffer zone substrate 10 to form a horizontally lying right triangular prism structure. Specifically, the bottom surface and one side surface of the wetland buffer zone substrate 10 are rectangular, the two side surfaces are right-angled triangles, and the top surface is a rectangle with a certain angle to the bottom surface. The length direction of the wetland buffer zone substrate 10 is the same as the length direction of the bottom surface, and the width direction of the wetland buffer zone substrate 10 is the same as the width direction of the bottom surface, which is also the direction of one right-angled side of the right-angled triangle on the side surface.

[0034] Several emergent aquatic plants 20 were planted on the slope 10a of the wetland buffer zone base 10.

[0035] The denitrifying bacteria system employs several polyhydroxyalkanoate strips 30, which are embedded in the wetland buffer zone substrate 10. The polyhydroxyalkanoate strips 30 are made of polyhydroxyalkanoate (PHAs) material / particles, and existing technologies can be directly adopted for the polyhydroxyalkanoate strips / strips / blocks.

[0036] The combination of the root system of emergent plants 20 in the wetland buffer zone system with the denitrifying bacteria system induced by polyhydroxyalkanoate strips 30 forms a highly efficient and synergistic microbial community structure, which has a targeted and significant effect on water purification, especially the purification of initial rainwater runoff. The combination of the emergent plant 20 root system and the PHAs-induced denitrifying bacteria system forms a complex microbial community structure. This community structure includes various types of microorganisms, such as nitrifying bacteria, denitrifying bacteria, photosynthetic bacteria, and heterotrophic bacteria. These microorganisms interact and work synergistically in the aerobic and anoxic zones surrounding the roots, jointly promoting the water purification process.

[0037] The baffle 40 has several mesh openings, and several baffles 40 are respectively embedded in the wetland buffer zone substrate 10. The baffle 40 has both high strength support and high water permeability. The water-permeable mesh structure of the baffle 40 can guide the water flow to form a laminar flow state, and by reducing the flow velocity, it can cause suspended solids and particulate pollutants to be intercepted step by step as they flow through, while reducing the erosion of the substrate by water impact.

[0038] In one embodiment, the slope angle of the wetland buffer zone substrate 10 is between 2° and 30°.

[0039] The slope angle range of the wetland buffer zone substrate 10 should be determined based on the specific conditions and characteristics of the actual wetland slope. Generally, the slope angle of the wetland buffer zone substrate 10 is fixed between 2° and 30°.

[0040] In one embodiment, the matrix in the wetland buffer zone substrate 10 is a mixture of one or more materials selected from soil, gravel, crushed stone, fly ash, ceramsite, and cinder.

[0041] Meanwhile, the thickness of the matrix layer is set to be consistent with the overall thickness of the wetland buffer zone matrix 10 to ensure the structural consistency and effectiveness of the purification function of the wetland buffer zone matrix 10. In other words, the wetland buffer zone matrix 10 is formed by stacking a matrix of one or more of the above-mentioned materials.

[0042] In one embodiment, the matrix particle size in the wetland buffer zone substrate 10 is between 1 cm and 3 cm to optimize the physical filtration and adsorption characteristics of the wetland buffer zone substrate 10.

[0043] In one embodiment, the emergent plant 20 is one or more of loosestrife, burdock, canna, thalia, and variegated reed.

[0044] Emergent plants 20 planted on the slope 10a of the wetland buffer zone base are generally selected from a variety of species. The selected emergent plants 20 should not only beautify the environment, but also have functions such as ecological restoration and water purification. Common emergent plant species 20 in wetland buffer zone systems include, but are not limited to, loosestrife, burdock, canna, thalia, and variegated reed.

[0045] In one embodiment, the length direction of the polyhydroxyalkanoate strip 30 is consistent with the length direction of the wetland buffer strip base 10, and the polyhydroxyalkanoate strip 30 is inclinedly disposed inside the wetland buffer strip base 10 and is consistent with the slope angle of the wetland buffer strip base 10.

[0046] The alignment of the polyhydroxyalkanoate strip 30's tilt angle with the slope angle of the wetland buffer zone substrate 10 is crucial for ensuring uniform water flow distribution. This design helps to evenly disperse pollutants in wastewater throughout the system, increasing the contact opportunities between denitrifying bacteria and pollutants, while reducing the formation of dead zones and preventing pollutant accumulation in localized areas. The consistency between the tilt angle and the slope angle significantly improves denitrification efficiency. Uniform water flow distribution extends the wastewater's residence time in the system, providing more sufficient reaction time for denitrifying bacteria. Simultaneously, this design helps maintain anoxic or microaerobic environments in the system, creating favorable conditions for the growth and activity of denitrifying bacteria, thereby optimizing the denitrification process.

[0047] In one embodiment, a plurality of vertical partitions 40 are provided inside the wetland buffer zone substrate 10, which divide the interior of the wetland buffer zone substrate 10 into a plurality of relatively independent working areas. A plurality of denitrifying bacteria systems are distributed vertically, preferably evenly, in each working area. The denitrifying bacteria systems in adjacent working areas are staggered or adjacent.

[0048] Reference Figure 1 Several vertical partitions 40 divide the wetland buffer zone substrate 10 into 9 relatively independent working areas; for example, in the working areas on the left with higher height, the denitrifying bacteria systems between adjacent working areas are staggered; in the two adjacent working areas on the right with lower height, the denitrifying bacteria systems are set adjacent to each other; and in the working area on the far right with the lowest height, due to its space limitations, no denitrifying bacteria system may be set.

[0049] In one embodiment, the vertical partitions 40 are movably connected to the wetland buffer zone base 10 via a detachable guide rail mechanism, allowing each vertical partition to be pulled out and replaced vertically. The wetland buffer zone system is configured with partition replacement cycle parameters corresponding to each working area. When the preset time threshold corresponding to the partition replacement cycle parameter is reached, the corresponding vertical partition is replaced as a whole and the denitrifying bacteria system is dynamically updated through a pull-out operation.

[0050] In this embodiment, the partition replacement cycle parameters for each work area can be the same or different, and can be determined according to the actual implementation situation. In addition, some work areas are equipped with partitions on both sides, and the corresponding partition replacement cycle parameters can be determined as one side or both sides according to the implementation situation.

[0051] The partition replacement cycle parameter is a time parameter, and therefore has a preset time threshold, such as one week, one month, or one year. When the preset time threshold is reached, it is considered that the vertical partition needs to be replaced. That is to say, for example, if the partition replacement cycle parameter of a certain work area is set to one month, then the corresponding preset time threshold is set to 720 hours (24 hours * 30 days), and the partition on the side of that work area is replaced every 720 hours.

[0052] In one embodiment, a plurality of vertical partitions 40 are provided inside the wetland buffer zone substrate 10, and inclined partitions 40 are provided on the slope 10a of the wetland buffer zone substrate 10. The inclined partitions 40, the plurality of vertical partitions 40 and the plurality of denitrifying bacteria systems divide the wetland buffer zone system into a pretreatment zone with emergent plants 20, a denitrification zone with denitrifying bacteria systems and a stabilization zone.

[0053] Among them, the stable zone usually only has a wetland buffer zone substrate 10.

[0054] This embodiment divides the wetland buffer zone system into functional zones of pretreatment zone, denitrification zone and stabilization zone, accurately isolates matrix materials of different levels, avoids mixing and optimizes the purification efficiency of each zone.

[0055] In one embodiment, the tilt angle of the inclined partition 40 is consistent with the slope angle.

[0056] In practice, the inclined partition can be embedded into the slope surface of the wetland buffer zone base 10.

[0057] In one embodiment, the mesh size is 1cm x 1cm.

[0058] In one embodiment, the partition 40 is fixed by a steel structure mesh.

[0059] By using a partition 40 made of corrosion-resistant steel, the partition 40 also has a certain degree of corrosion resistance.

[0060] In one embodiment, the partition 40 and the wetland buffer zone base 10 are anchored together to form a tight whole, which can resist the displacement risk caused by long-term water flow erosion and buffer the structural deformation caused by the root expansion of emergent plants 20, thereby ensuring the long-term operational stability of the wetland buffer zone system in complex environments.

[0061] In one embodiment, during the implementation of the wetland buffer zone system, a suitable location is first selected for the construction of the wetland buffer zone substrate 10, with a rational design based on the terrain and soil conditions. During the construction of the wetland buffer zone substrate 10, polyhydroxyalkanoate strips 30 and partitions 40 are introduced to ensure that the PHAs are fully mixed and in contact within the wetland buffer zone substrate 10. Next, emergent plants 20 suitable for the wetland environment are planted on the slope of the wetland buffer zone substrate 10 to fully utilize their purification function.

[0062] This invention can be applied to farmland drainage ditches and riverbanks to effectively intercept and remove nitrogen pollutants from farmland runoff, thereby controlling agricultural non-point source pollution and improving the water environment. At the same time, this invention can also be used for the deep treatment of wastewater effluent from sewage treatment plants, which can further reduce nitrogen concentration, meet stricter emission standards, and promote the recycling of water resources.

[0063] The preferred embodiments of this utility model have been described in detail above. However, it should be understood that after reading the above teachings, those skilled in the art can make various alterations or modifications to this utility model. These equivalent forms also fall within the scope defined by the appended claims.

Claims

1. A wetland buffer zone system based on a polyhydroxyalkanoate-induced denitrifying bacteria system, characterized in that, The wetland buffer zone system includes: The wetland buffer zone base has a sloping top surface. Several emergent aquatic plants were planted on the slope of the wetland buffer zone substrate. The denitrifying bacteria system employs several polyhydroxyalkanoate strips made of polyhydroxyalkanoate material, with the polyhydroxyalkanoate strips respectively embedded in the wetland buffer zone substrate; Several partitions, each with a mesh, are embedded in the wetland buffer zone substrate.

2. The wetland buffer zone system based on a polyhydroxyalkanoate-induced denitrifying bacteria system as described in claim 1, characterized in that, The slope angle of the wetland buffer zone substrate is between 2° and 30°; And / or, the matrix in the wetland buffer zone substrate is a mixture of one or more materials selected from soil, gravel, crushed stone, fly ash, ceramsite and cinder; And / or, the matrix particle size in the wetland buffer zone matrix is ​​between 1 cm and 3 cm.

3. The wetland buffer zone system based on a polyhydroxyalkanoate-induced denitrifying bacteria system as described in claim 1, characterized in that, The emergent plants are one or more of the following: loosestrife, burdock, canna lily, thalia elata, and variegated reed.

4. The wetland buffer zone system based on a polyhydroxyalkanoate-induced denitrifying bacteria system as described in claim 1, characterized in that, The wetland buffer zone substrate is provided with several vertical partitions, which divide the interior of the wetland buffer zone substrate into several relatively independent working areas. Several denitrifying bacteria systems are distributed vertically in each working area, and the denitrifying bacteria systems in adjacent working areas are either staggered or adjacent.

5. The wetland buffer zone system based on a polyhydroxyalkanoate-induced denitrifying bacteria system as described in claim 4, characterized in that, The vertical partitions are connected to the wetland buffer zone substrate by a detachable guide rail mechanism, allowing each vertical partition to be pulled out and replaced in the vertical direction. The wetland buffer zone system is configured with partition replacement cycle parameters corresponding to each working area. When the preset time threshold corresponding to the partition replacement cycle parameter is reached, the corresponding vertical partition is replaced as a whole and the denitrifying bacteria system is dynamically updated by pulling it out.

6. The wetland buffer zone system based on a polyhydroxyalkanoate-induced denitrifying bacteria system as described in claim 1, characterized in that, The wetland buffer zone substrate is provided with several vertical partitions inside, and the slope of the wetland buffer zone substrate is provided with inclined partitions. The inclined partitions, several vertical partitions, and several denitrifying bacteria systems divide the wetland buffer zone system into a pretreatment zone with emergent plants, a denitrification zone with denitrifying bacteria systems, and a stabilization zone.

7. The wetland buffer zone system based on a polyhydroxyalkanoate-induced denitrifying bacteria system as described in claim 6, characterized in that, The tilt angle of the inclined partition is consistent with the slope angle.

8. The wetland buffer zone system based on a polyhydroxyalkanoate-induced denitrifying bacteria system as described in claim 1, characterized in that, The mesh has a length and width of 1cm × 1cm; And / or, the partition is fixed by a steel structure mesh.

9. The wetland buffer zone system based on a polyhydroxyalkanoate-induced denitrifying bacteria system as described in claim 1, characterized in that, The partition is anchored to the wetland buffer zone substrate.

10. The wetland buffer zone system based on a polyhydroxyalkanoate-induced denitrifying bacteria system as described in any one of claims 1 to 9, characterized in that, The length direction of the polyhydroxyalkanoate strip is consistent with the length direction of the wetland buffer zone substrate, and the polyhydroxyalkanoate strip is inclinedly disposed inside the wetland buffer zone substrate and has the same slope angle as the wetland buffer zone substrate.

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