An experimental device for purifying water in a low-temperature environment by using an artificial wetland

Abstract

This invention discloses an experimental device for evaluating the water purification performance of constructed wetlands under low-temperature conditions, relating to the field of wastewater treatment experimental technology. The device includes an environmental chamber and multiple parallel experimental units. The environmental chamber contains a low-temperature medium, and each experimental unit includes a water storage tank, a water pump, and a substrate-filled column. The water storage tank is partially submerged in the low-temperature medium and has a support plate inside. The support plate is arranged with a layer of *Potamogeton crispus* and a layer of aquatic plants from bottom to top, separated from the upper water purification zone by an intermediate filter. The water pump, substrate-filled column, and water storage tank are connected by pipelines to form a circulating water system. By simulating a cold winter environment using the low-temperature medium, and utilizing multiple independent experimental units, the purification efficiency of different substrate and plant combinations under low-temperature conditions can be compared simultaneously, recreating the low-temperature operation scenario of natural wetlands and achieving reliable and controllable testing of the water purification performance of constructed wetlands under low-temperature conditions.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment experimental technology, and in particular to an experimental apparatus for the water purification performance of artificial wetlands under low-temperature conditions. Background Technology

[0002] Constructed wetland technology, as a highly efficient ecological wastewater treatment system, mainly relies on the synergistic effect of substrate, aquatic plants and microorganisms to purify pollutants such as total nitrogen, total phosphorus, BOD, suspended solids, heavy metals and antibiotics in wastewater. It has the advantages of simple management and maintenance, low investment, good effluent quality and low energy consumption, and has broad application prospects in wastewater treatment.

[0003] However, the promotion and application of constructed wetlands in cold regions faces severe challenges. In cold northern regions, low winter temperatures cause wetland aquatic plants to wither or die, significantly reduce microbial activity, inhibit biochemical processes such as nitrification and denitrification, and drastically reduce the wetland's purification function. Specific problems include: frozen surface soil, icing of filler layers, pipe rupture, and oxygen deficiency in the bed, making it difficult for constructed wetlands to operate normally in winter. Although existing technologies attempt to mitigate the effects of low temperatures by screening for cold-resistant plants, building insulated greenhouses, and covering with mulch or ice, cold-resistant plants can only survive in low-temperature environments, with limited purification effects; while traditional insulation measures typically only extend the wetland's operating time by 1-2 months and have low treatment efficiency, failing to completely solve the problem of winter operation in cold regions.

[0004] To further improve winter operation, methods have emerged that utilize external energy sources for insulation or heating. For example, geothermal resources can be used to raise the wetland bed temperature through circulating heating components. However, this method has specific geological requirements, a complex system structure, and high initial investment. Another approach proposes installing heating mechanisms and aeration systems at the bottom of the wetland to maintain the substrate layer temperature with hot air, but this consumes a significant amount of energy and makes it difficult to precisely control heat loss in low-temperature environments. Furthermore, existing experimental devices mostly operate at ambient temperatures, lacking the ability to simulate low-temperature conditions in cold regions. This prevents the simultaneous study of the synergistic effects of multiple parameters such as temperature, flow rate, and the combination of water purification materials, leading to a disconnect between experimental data and actual environmental conditions and insufficient basis for optimized design.

[0005] Therefore, there is an urgent need for experimental platforms capable of simulating the effects of multiple parameters under low-temperature conditions in cold-region constructed wetland technology, so as to provide reliable data support for the winter operation of constructed wetlands in cold regions. Summary of the Invention

[0006] The purpose of this invention is to provide an experimental device for testing the water purification performance of constructed wetlands under low-temperature conditions, so as to solve the problems existing in the prior art and realize the testing of the water purification performance of constructed wetlands under low-temperature conditions.

[0007] To achieve the above objectives, the present invention provides the following solution: This invention provides an experimental apparatus for assessing the water purification performance of artificial wetlands under low-temperature conditions, comprising: An environmental chamber, wherein a low-temperature medium is provided inside the environmental chamber; Several experimental units are provided, each including a water tank, a water pump, and a substrate-filling column. All water tanks are fixedly installed inside the environmental chamber and partially inserted into the low-temperature medium. Each water tank contains a purification zone and a support plate located below the purification zone. The support plate has multiple first water passages, and from bottom to top, a layer of water hyacinth and a layer of aquatic plants are arranged on the support plate. The purification zone and the aquatic plant layer support are separated by an intermediate filter, which filters the water flowing from the aquatic plant layer to the purification zone. Each substrate-filling column is vertically arranged and filled with substrate material. In the same experimental unit, the outlet of the water pump is connected to the inlet at the top of the substrate-filling column, the outlet at the bottom of the substrate-filling column is connected to the inlet at the bottom of the water tank, and the purification zone is connected to the inlet of the water pump.

[0008] Preferably, the cryogenic medium is an ice-salt mixture.

[0009] Preferably, the intermediate filter includes a first housing and a filter medium laid on the surface of the first housing, and the first housing is provided with a plurality of second water passages; the purified water zone is formed between the inner wall of the first housing and the inner wall of the environmental chamber.

[0010] Preferably, the top of the first housing is fixed with at least two first lugs for attaching to the top of the water storage tank; the filter medium is a filter screen.

[0011] Preferably, there is a gap between the tray and the bottom surface of the water tank; at least two second lugs are fixed on the tray for attaching to the top of the water tank.

[0012] Preferably, the tray is covered with a wire mesh to prevent the grass layer from falling through the first drainage hole.

[0013] Preferably, the matrix material is at least one of the following: ceramsite, gravel, rice straw, zeolite, steel slag, fly ash, activated carbon, anthracite, limestone, and quartz particles. The matrix materials in different matrix-filled columns may be the same or different.

[0014] Preferably, the environmental tank is provided with a receiving cavity for each of the water storage tanks, and the different receiving cavities are isolated from each other; any two adjacent receiving cavities are separated by a partition.

[0015] Preferably, a flow regulating device and a flow meter are also provided on the connecting pipe between the water pump and the substrate filling column; a temperature measuring device is provided inside the environmental chamber.

[0016] Preferably, the flow regulating device is a flow regulating valve; the water pump is a flow pump.

[0017] The present invention achieves the following technical effects compared to the prior art: The experimental apparatus for assessing the water purification performance of constructed wetlands under low-temperature conditions, as described in this invention, effectively overcomes the shortcomings of traditional experimental apparatuses in simulating low-temperature environments. Through an environmental chamber with a built-in low-temperature medium, it provides a stable, uniform, and adjustable low-temperature environment for multiple experimental units, realistically simulating the climatic conditions of winter in cold regions. This fundamentally solves the problem of the lack of an effective low-temperature simulation experimental platform in existing technologies. The low-temperature medium (especially the ice-salt eutectic system) can provide a constant and adjustable low-temperature environment, effectively overcoming the problems of large temperature fluctuations and difficulty in maintaining a stable temperature over long periods in conventional experimental apparatuses during low-temperature simulations, thus providing a reliable environmental basis for evaluating purification performance.

[0018] A parallel multi-unit experimental design was adopted, with each unit containing an independent water tank, water pump, and substrate-filled column. This allows for the simultaneous execution of multiple sets of experiments, such as comparing the purification performance differences of different substrate materials and combinations of aquatic plants under the same low-temperature conditions. The water tank design (featuring a purification zone, tray, aquatic plant layer, water hyacinth layer, and intermediate filter) integrates the aquatic plants and the effluent area, immersing them together in the low-temperature medium. This highly replicates the realistic low-temperature scenario of plant root-water interaction in natural wetlands, ensuring consistency between experimental conditions and the actual operating environment, resulting in more reliable and practical purification performance data. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the experimental device for the water purification performance of artificial wetlands under low-temperature conditions according to the present invention. Figure 2 This is a schematic diagram of the structure of the intermediate filter body in this invention; Figure 3 This is a schematic diagram of the structure of the tray in this invention; Figure 4 This is a partial structural schematic diagram of the experimental device for the water purification performance of artificial wetlands under low-temperature conditions according to the present invention. In the diagram: 1. Environmental chamber; 2. First connecting pipe; 3. Water pump; 4. Flow regulating device; 5. Flow meter; 6. Matrix filling column; 7. Second connecting pipe; 8. Temperature measuring device; 9. Partition; 10. Water storage tank; 11. First shell; 12. Second water passage; 13. First hanging ear; 14. Filter medium; 15. Support plate; 16. First water passage; 17. Second hanging ear; 18. Potamogeton layer; 19. Aquatic plant layer; 20. Low temperature medium; 21. Support plate. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] The purpose of this invention is to provide an experimental device for testing the water purification performance of constructed wetlands under low-temperature conditions, so as to solve the problems existing in the prior art and realize the testing of the water purification performance of constructed wetlands under low-temperature conditions.

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] like Figures 1 to 4 As shown, this embodiment provides an experimental apparatus for testing the water purification performance of artificial wetlands under low-temperature conditions, comprising: Environmental chamber 1, which contains a low-temperature medium 20; Several experimental units, each including a water tank 10, a water pump 3, and a substrate-filling column 6, are constructed. All water tanks 10 are fixedly installed inside the environmental chamber 1 and partially inserted into the low-temperature medium 20. Each water tank 10 contains a water purification zone and a support plate 15 located below the water purification zone. The support plate 15 has multiple first water passages 16. From bottom to top, a layer of water hyacinth 18 and a layer of aquatic plants 19 are arranged on the support plate 15. The water purification zone and the aquatic plant layer 19 are connected by an intermediate support. The filter elements are separated, with the middle filter element used to filter the water flowing from the aquatic plant layer 19 to the water purification zone; each substrate-filled column 6 is vertically arranged and filled with substrate material; in the same experimental unit, the outlet of the water pump 3 is connected to the inlet at the top of the substrate-filled column 6, the outlet at the bottom of the substrate-filled column 6 is connected to the inlet at the bottom of the water storage tank 10 through the second connecting pipe 7, and the water purification zone is connected to the inlet of the water pump 3 through the first connecting pipe 2.

[0025] In the optional embodiments of this example, the cryogenic medium 20 is preferably an ice-salt mixture.

[0026] It is worth noting that since the physical filtration of the substrate layer in the constructed wetland is negligibly affected by the low temperature environment, the substrate filling columns 6 in this embodiment are all located outside the environmental tank 1. The Potamogeton crispus in the Potamogeton crispus layer 18 can efficiently absorb ammonia nitrogen, total nitrogen, and total phosphorus in the water, convert them into its own biomass, inhibit the excessive growth of algae, and play a role in sewage filtration and water purification.

[0027] In the optional embodiments of this example, a preferred embodiment includes a first housing 11 and a filter medium 14 laid on the surface of the first housing 11. The first housing 11 is provided with a plurality of second water passage holes 12. The first housing 11 is a rectangular box-shaped structure with an opening at the top and one side. The purified water zone is formed between the inner wall of the first housing 11 and the inner wall of the environmental chamber 1. The second water passage holes 12 facilitate the passage of water. The filter medium 14 mainly performs physical filtration on the water entering the purified water zone, preventing the water from carrying large particles from the waterweed layer 18 and the aquatic plant layer 19 into the purified water zone. In this embodiment, the filter medium 14 is a filter screen. The filter screen does not contain any chemical or biological components and has no adsorption effect. It only plays a single coarse filtration role for large particles, preventing the water from carrying large particles from the waterweed layer 18 and the aquatic plant layer 19 into the purified water zone.

[0028] In the optional embodiments of this example, a preferred embodiment has at least two first lugs 13 fixed to the top of the first housing 11 for attaching to the top of the water tank 10; the filter medium 14 is a filter screen; there is a gap between the tray 15 and the bottom surface of the water tank 10; and at least two second lugs 17 fixed to the tray 15 for attaching to the top of the water tank 10. Both the intermediate filter and the tray 15 are mounted in a hook-and-loop manner, facilitating the disassembly, cleaning, and replacement of the internal filter medium 14, the water spinach layer 18, and the aquatic plants, simplifying operation and maintenance. The substrate-filled column 6 can also be easily filled with or replaced with different combinations of fillers, providing high experimental flexibility.

[0029] In the optional embodiments of this example, a preferred option is that a wire mesh is laid on the tray 15 to prevent the grass layer 18 from falling through the first water hole 16.

[0030] In the optional schemes of this embodiment, it is more preferred that the matrix material is at least one of the following: expanded clay, gravel, rice straw, zeolite, steel slag, fly ash, activated carbon, anthracite, limestone, and quartz particles; the matrix material is the matrix layer simulating the constructed wetland; the matrix materials in different matrix filling columns 6 may be the same or different; by filling different matrix materials in different matrix filling columns 6, the purification performance of constructed wetlands composed of different combinations of water spinach layer 18, aquatic plant layer 19, and matrix material layer can be tested.

[0031] In the optional scheme of this embodiment, a more preferred embodiment is that the environmental chamber 1 is provided with a receiving cavity for each water storage tank 10, and the different receiving cavities are isolated from each other; any two adjacent receiving cavities are separated by a partition 9. In addition, the outer wall of the water storage tank 10 in this embodiment is fixedly connected to the inner wall of the receiving cavity by a plurality of support plates 21 to ensure the stable fixation of each water storage tank 10.

[0032] In the optional embodiments of this example, a preferred embodiment is that the connecting pipe between the water pump 3 and the matrix filling column 6 is also equipped with a flow regulating device 4 and a flow meter 5; and a temperature measuring device 8 is installed inside the environmental chamber 1. By setting up the flow regulating device 4, the flow meter 5, and the temperature measuring device 8, the hydraulic load, hydraulic residence time, and operating temperature of each experimental unit can be precisely controlled and monitored in real time, greatly improving the controllability of the experimental process and the repeatability and accuracy of the experimental results.

[0033] In the optional schemes of this embodiment, it is more preferred that the flow regulating device 4 is a flow regulating valve and the water pump 3 is a flow pump.

[0034] The specific working principle and usage process of the experimental setup for the water purification performance of artificial wetlands under low-temperature conditions in this embodiment are as follows: (1) Accurate preparation before the experiment: First, the environmental chamber 1 is placed in a stable position and filled with a sufficient amount of cryogenic medium 20, such as an ice-salt mixture, to simulate the required constant low-temperature environment (e.g., 0°C to -10°C or lower). The cryogenic medium 20 maintains the uniformity and stability of the temperature inside the chamber through its eutectic properties.

[0035] For each individual experimental unit, the following assembly and preparation should be performed: Water tank 10 installation: The water tank 10 is fixed to the corresponding cavity of the environmental tank 1 by the support plate 21, so that its lower half is immersed in the low temperature medium 20; the water tank 10 is arranged from bottom to top with a tray 15, a layer of water hyacinth 18 and a layer of aquatic plants 19; the tray 15 is suspended from the top edge of the water tank 10 by the second hanging ear 17 on it, and the space below it is connected to the water inlet at the bottom of the water tank 10; a wire mesh is laid on the tray 15 to prevent water hyacinth from falling; the first shell 11 in the intermediate filter is suspended from the top of the water tank 10 by its first hanging ear 13, located on top of the aquatic plant layer 19, thereby forming the purified water zone between the inner wall of the water tank 10 and the shell of the filter device.

[0036] Experimental unit water circuit connection: The inlet of water pump 3 is connected to the clean water area of ​​water storage tank 10 through the first connecting pipe 2; the outlet of water pump 3 is connected to the flow regulating device 4 (such as regulating valve) and flow meter 5 in sequence through the pipeline, and finally connected to the inlet at the top of the vertically set matrix filling column 6; the matrix filling column 6 is pre-filled with the selected matrix material (such as single or combined fillers such as ceramsite, zeolite, steel slag, etc.); the outlet at the bottom of the matrix filling column 6 is connected to the inlet at the bottom of water storage tank 10 through the second connecting pipe 7, thus forming a closed water circulation experimental loop.

[0037] Multiple experimental setups: If multiple comparative experiments are required, multiple isolated containment chambers (separated by partitions 9) are set up in parallel within environmental chamber 1, and each containment chamber is equipped with an independent experimental unit; each experimental unit can use different combinations of substrate materials, different types or densities of aquatic plants, different amounts of water spinach filling, etc., so as to conduct synchronous comparative studies under the same low temperature background.

[0038] Monitoring equipment installation: A temperature measuring device 8 is installed inside the environmental chamber 1 to monitor the temperature of the test environment in real time.

[0039] (2) After the apparatus is ready, run the experiment according to the following steps: Water injection and start-up: Inject a certain volume of simulated sewage (or actual sewage) to be treated into the clean water area of ​​the water storage tank 10 of each experimental unit, and then start the water pump 3.

[0040] Circulation and purification process: Pump 3 draws water from the purification area, and after the flow rate is controlled and monitored by the flow regulating device 4 and the flow meter 5 (5), it is transported to the top of the substrate-filled column 6. Under the action of gravity, the sewage flows from top to bottom through the packing layer in the substrate-filled column 6. In this process, the packing material removes suspended solids, some organic matter, nitrogen, phosphorus and heavy metals and other pollutants in the water through physical and chemical actions such as adsorption, ion exchange and filtration, simulating the role of the substrate layer in the constructed wetland.

[0041] Biochemical and plant interactions under low-temperature conditions: Water, after preliminary treatment in the substrate layer, enters from the bottom of the water storage tank 10 through the second connecting pipe 7 and flows upwards sequentially through the space below the support plate 15, the first water passage 16, the water hyacinth layer 18, and the aquatic plant layer 19. The entire water storage tank 10 is submerged in the low-temperature medium 20, providing a stable and realistic low-temperature environment for the water, water hyacinth, and aquatic plant root zones. Under these low-temperature conditions: The 18 layer of turmeric can still maintain a certain level of biological activity at low temperatures. The cold-resistant microorganisms attached to its surface and growing inside it carry out limited but still existing biochemical reactions such as nitrification and denitrification at low temperatures, further degrading pollutants.

[0042] The root systems of aquatic plants (especially some cold-resistant varieties) play a role in low-temperature environments, synergistically participating in the removal of pollutants through root absorption, root oxygen secretion (although reduced at low temperatures), and providing an attachment interface for microorganisms.

[0043] The entire upflow process simulates the transport and purification of wastewater in the root zone of constructed wetland plants.

[0044] Filtration and Recirculation: After passing through the aquatic plant layer 19, the water reaches the intermediate filter. The water then flows through the second water passage 12 on the first housing 11 and the filter medium 14 on its surface, filtering out any plant debris or large particles before entering the purified water zone, completing one purification cycle. Subsequently, the water in the purified water zone is drawn back by the water pump 3 to begin the next cycle. The entire system operates continuously or intermittently at a set flow rate.

[0045] Parameter control and monitoring: During the experiment, the hydraulic load and hydraulic residence time of each experimental unit are precisely controlled by the flow regulating device 4. The required low-temperature conditions are continuously monitored and maintained by the temperature measuring device 8 in the environmental chamber 1. The temperature can be stabilized by adding or replacing the low-temperature medium 20.

[0046] (3) Performance testing and data analysis After the system reaches a stable state (which usually requires a certain acclimatization period), performance testing begins: Sampling: Water samples were periodically collected from the clean water area (representing "outlet water") of the water storage tank 10 in each experimental unit, as well as from the initial water injection point (representing "inlet water") or the inlet and outlet of the matrix filling column 6, and other key nodes.

[0047] Testing: Water samples are analyzed to detect key water quality indicators such as chemical oxygen demand, ammonia nitrogen, total nitrogen, total phosphorus, and heavy metal ion concentration.

[0048] Analysis: By comparing the influent and effluent water quality data of different experimental units under the same low temperature and different operating parameters (such as flow rate, packing material combination, and plant species), the influence of various factors on the water purification performance (such as removal efficiency and treatment load) of constructed wetlands under low temperature environment is quantitatively analyzed; the differences in purification effect of different substrate combinations are compared, and the synergistic effect of specific aquatic plants and Potamogeton crispus under low temperature is evaluated.

[0049] (4) During or after the experiment, maintenance and condition changes can be easily carried out to conduct a series of studies: ① The intermediate filter and tray 15 can be removed from the water storage tank 10 periodically to clean or replace the filter media 14, water spinach and aquatic plants; ② The filler in the matrix-filled column 6 can be emptied and refilled to test the performance of different matrix materials or combinations thereof; ③ Different low-temperature levels can be adjusted and simulated by changing the type or proportion of the low-temperature medium 20 in the environmental chamber 1; ④ The effect of different hydraulic conditions on the low-temperature purification effect can be studied by adjusting the flow regulating device 4.

[0050] In summary, the experimental setup in this embodiment, by constructing a cyclic experimental system integrating low-temperature simulation, matrix filtration, plant-microbe synergistic purification, and precise control of hydraulic parameters, achieves a high degree of simulation of the operating conditions of constructed wetlands under low-temperature conditions in cold regions. Specifically, the working process simulates the complete path of wastewater flowing through the wetland matrix layer and plant root zone, undergoing physical and biological synergistic purification at low temperatures. It enables a systematic, controllable, and repeatable study of the impact of multiple variables on the water purification performance of constructed wetlands under low-temperature conditions, providing strong experimental data support and a technology development platform for the optimized design, material selection, and operational parameter formulation of constructed wetlands in cold regions.

[0051] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. An experimental apparatus for the water purification performance of artificial wetlands under low-temperature conditions, characterized in that, include: An environmental chamber, wherein a low-temperature medium is provided inside the environmental chamber; Several experimental units are provided, each including a water tank, a water pump, and a substrate-filling column. All water tanks are fixedly installed inside the environmental chamber and partially inserted into the low-temperature medium. Each water tank contains a purification zone and a support plate located below the purification zone. The support plate has multiple first water passages, and from bottom to top, a layer of water hyacinth and a layer of aquatic plants are arranged on the support plate. The purification zone and the aquatic plant layer support are separated by an intermediate filter, which filters the water flowing from the aquatic plant layer to the purification zone. Each substrate-filling column is vertically arranged and filled with substrate material. In the same experimental unit, the outlet of the water pump is connected to the inlet at the top of the substrate-filling column, the outlet at the bottom of the substrate-filling column is connected to the inlet at the bottom of the water tank, and the purification zone is connected to the inlet of the water pump.

2. The experimental apparatus for testing the water purification performance of artificial wetlands under low-temperature conditions according to claim 1, characterized in that: The cryogenic medium is a mixture of ice and salt.

3. The experimental apparatus for testing the water purification performance of artificial wetlands under low-temperature conditions according to claim 1, characterized in that: The intermediate filter includes a first housing and a filter medium laid on the surface of the first housing. The first housing is provided with a plurality of second water passages. The purified water zone is formed between the inner wall of the first housing and the inner wall of the environmental chamber.

4. The experimental apparatus for testing the water purification performance of artificial wetlands under low-temperature conditions according to claim 3, characterized in that: The top of the first housing is fixed with at least two first lugs for attaching to the top of the water storage tank; the filter medium is a filter screen.

5. The experimental apparatus for testing the water purification performance of artificial wetlands under low-temperature conditions according to claim 1, characterized in that: There is a gap between the tray and the bottom surface of the water tank; at least two second lugs are fixed on the tray for attaching to the top of the water tank.

6. The experimental apparatus for testing the water purification performance of artificial wetlands under low-temperature conditions according to claim 1, characterized in that: The tray is covered with wire mesh, which is used to prevent the grass layer from falling through the first drainage hole.

7. The experimental apparatus for testing the water purification performance of artificial wetlands under low-temperature conditions according to claim 1, characterized in that: The matrix material is at least one of the following: ceramsite, gravel, rice straw, zeolite, steel slag, fly ash, activated carbon, anthracite, limestone, and quartz particles. The matrix materials in different matrix-filled columns may be the same or different.

8. The experimental apparatus for testing the water purification performance of artificial wetlands under low-temperature conditions according to claim 1, characterized in that: Each environmental tank is provided with a receiving cavity corresponding to each of the water storage tanks, and different receiving cavities are isolated from each other; any two adjacent receiving cavities are separated by a partition.

9. The experimental apparatus for testing the water purification performance of artificial wetlands under low-temperature conditions according to claim 1, characterized in that: The connecting pipe between the water pump and the substrate filling column is also equipped with a flow regulating device and a flow meter; the environmental chamber is equipped with a temperature measuring device.

10. The experimental apparatus for testing the water purification performance of artificial wetlands under low-temperature conditions according to claim 9, characterized in that: The flow regulating device is a flow regulating valve; the water pump is a flow pump.

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