Constructed wetland treatment system, method and application

Abstract

The invention provides a constructed wetland treatment system and method and application, and belongs to the technical field of pollutant treatment. The constructed wetland treatment system comprises a constructed wetland pool, a supporting layer and a matrix functional layer are sequentially arranged in the constructed wetland pool from bottom to top, wetland plants are planted on the matrix functional layer, and the matrix functional layer is a mixture of Manchuino ore and quartz sand. According to the invention, the Manchuo mine is used as a matrix filler of an artificial wetland system, and through the electron supply, adsorption and coprecipitation effects of the Manchuo mine, the form of heavy metals is changed, the adsorption of micro-organic pollutants and the adsorption and precipitation of the heavy metals are promoted, and the removal of the heavy metals and part of the micro-organic pollutants is realized; meanwhile, microorganic micropollutants are degraded through a synergistic effect with microbial anabolism and mediated oxidation-reduction reaction thereof and plant assimilation absorption, so that a multifunctional pollutant removal system for the constructed wetland is constructed, and the utilization rate of the constructed wetland is effectively increased while effluent is ensured to meet the national standard.

Description

Technical Field

[0001] This invention belongs to the field of pollutant treatment technology, specifically relating to an artificial wetland treatment system, method, and application. Background Technology

[0002] The main pollutants considered in wastewater treatment include COD, ammonia nitrogen, TP, and TN. Industrial parks often contain heavy metals and microorganisms such as petroleum hydrocarbons (TPH), which are difficult to remove and degrade. Currently, removing specific pollutants from these wastewaters, especially those from industrial areas and petrochemical plants, faces numerous challenges. Traditional treatment methods are typically inefficient and have limited effectiveness in removing certain pollutants, particularly metal ions and microorganisms like petroleum hydrocarbons. Furthermore, these methods may require expensive chemical reagents, energy-intensive processes, and complex operation and maintenance procedures.

[0003] Therefore, finding more economical and environmentally friendly wastewater treatment methods has become an urgent problem to be solved. Summary of the Invention

[0004] The purpose of this invention is to solve the problems existing in the prior art and provide an artificial wetland treatment system, method and application that can remove multiple pollutants at the same time, providing a solution to meet the global demand for water resource protection and pollution control.

[0005] This invention is achieved through the following technical solution:

[0006] In a first aspect, the present invention provides an artificial wetland treatment system, comprising an artificial wetland pond, wherein a support layer and a substrate functional layer are arranged sequentially from bottom to top within the artificial wetland pond, and wetland plants are planted on the substrate functional layer.

[0007] A further improvement of the present invention is that:

[0008] The matrix functional layer is a mixture of Makino ore and quartz sand.

[0009] A further improvement of the present invention is that:

[0010] The mass ratio of quartz sand to Makino ore in the matrix functional layer is 1 to 2:1.

[0011] A further improvement of the present invention is that:

[0012] The particle size of both the Makino ore and the quartz sand is 0.5-1 cm.

[0013] A further improvement of the present invention is that:

[0014] The support layer is composed of gravel with a particle size of 3-4 cm.

[0015] A further improvement of the present invention is that:

[0016] The wetland plants are one of the following: calamus, reed, water onion, rush, water celery, or canna.

[0017] A further improvement of the present invention is that:

[0018] The artificial wetland pool has an inlet at the bottom of its side wall and an outlet at the top of its side wall.

[0019] In a second aspect, the present invention provides a method for treating artificial wetlands, wherein the above-mentioned artificial wetland treatment system is used to treat wastewater. The wastewater flows sequentially through a support layer and a matrix functional layer for purification before being discharged. Under the synergistic effect of plants, microorganisms and matrix, micro-organic pollutants and heavy metals are effectively removed.

[0020] A further improvement of the present invention is that:

[0021] The influent to the constructed wetland treatment system is the Class B standard effluent from the wastewater treatment plant.

[0022] A third aspect of the present invention provides an application of the above-described constructed wetland treatment system in wastewater treatment.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] This invention uses Makino mineral as the substrate filler in an artificial wetland system. Through the electron-donating, adsorption, and co-precipitation effects of Makino mineral, the form of heavy metals is altered, promoting the adsorption of microorganisms and the adsorption and precipitation of heavy metals, thereby achieving the removal of heavy metals and some microorganisms. Simultaneously, it works synergistically with microbial anabolism and its mediated redox reactions, as well as plant assimilation and absorption, oxidizing Fe(II) and S(-II) in Makino mineral to Fe through atmospheric reoxygenation and oxygen secretion from plant roots. 3+ SO4 2- Simultaneously, a Fenton-like effect is generated, producing free radicals such as hydroxyl groups to oxidize and decompose micro-organic pollutants, while Fe... 3+ and SO4 2- Under hypoxic or anaerobic conditions, it acts as an electron acceptor and uses microorganisms (such as TPH) as electron donors, and is reduced to Fe by microorganisms such as iron-sulfur reducing bacteria. 2+ S 2- This system achieves Fe and S cycling to prevent Fe and S from exceeding standards in the effluent while simultaneously degrading micro-organic pollutants, thus constructing a multifunctional pollutant removal system for constructed wetlands.

[0025] The constructed wetland system of this invention can remove multiple pollutants from water simultaneously, ensuring that the effluent meets national standards while effectively improving the utilization rate of constructed wetlands.

[0026] This invention fully considers the complex combination of pollutants in wastewater, and utilizes the characteristics of Makino minerals and their synergistic effect with plants and microorganisms to achieve comprehensive and efficient removal of multiple pollutants, providing a water treatment solution with environmental sustainability and economic benefits to meet global needs for water resource protection and pollution control. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the constructed wetland treatment system in an embodiment of the present invention;

[0028] Figure 1 In the middle, 1. Artificial wetland pond, 2. Support layer, 3. Substrate functional layer, 4. Wetland plants, 5. Inlet, 6. Outlet;

[0029] Figure 2a The effluent concentration of TAs in Example 2, Comparative Example 1, and Comparative Example 2;

[0030] Figure 2b The effluent concentration of As(III) in Example 2, Comparative Example 1, and Comparative Example 2;

[0031] Figure 2c The effluent concentration of As(V) in Example 2, Comparative Example 1, and Comparative Example 2;

[0032] Figure 2d The effluent concentration of TPH in Example 2, Comparative Example 1, and Comparative Example 2;

[0033] Figure 3a The concentration of As(III) in artificial wetland plants and substrate functional layers in Example 2, Comparative Example 1, and Comparative Example 2 after 120 days of system operation;

[0034] Figure 3b The concentration of As(V) in the artificial wetland plants and substrate functional layer in Example 2, Comparative Example 1 and Comparative Example 2 after the system has been running for 120 days;

[0035] Figure 3c The concentrations of TAs in the constructed wetland plants and substrate functional layers in Example 2, Comparative Example 1, and Comparative Example 2 after 120 days of system operation;

[0036] Figure 3d The concentration of TPH in the artificial wetland plants and substrate functional layer in Example 2, Comparative Example 1, and Comparative Example 2 after the system has been running for 120 days;

[0037] Figure 4a XPS characterization spectra of S(IV) and S(VI) on the surface of Makino ore after 120 days of system operation in Example 2;

[0038] Figure 4b XPS characterization spectra of Fe(II) and Fe(III) on the surface of Makino ore after 120 days of system operation in Example 2;

[0039] Figure 4c XPS characterization spectra of As(III) and As(V) on the surface of Makino ore after 120 days of system operation in Example 2;

[0040] Figure 4d To compare the XPS characterization spectra of Fe(II) and Fe(III) on the magnetite surface after 120 days of system operation;

[0041] Figure 4e To compare the XPS characterization spectra of As(III) and As(V) on the magnetite surface after 120 days of system operation;

[0042] Figure 5a The COD concentration in the effluent of Example 2, Comparative Example 1, and Comparative Example 2;

[0043] Figure 5b The total phosphorus concentration in the effluent of Example 2, Comparative Example 1, and Comparative Example 2;

[0044] Figure 5c The ammonia nitrogen concentration in the effluent of Example 2, Comparative Example 1, and Comparative Example 2;

[0045] Figure 5d The effluent concentrations of nitrate nitrogen in Example 2, Comparative Example 1, and Comparative Example 2 are shown.

[0046] Figure 6 The distribution of dissolved oxygen (DO) in the bottom, middle, and upper layers and the surface of the water in constructed wetland systems with Makino ore and quartz sand combination (Example 2), quartz sand (Comparative Example 1), and magnetite (Comparative Example 2) as the matrix functional layer is shown. Examples 2, 1, and 2 each have two groups.

[0047] Figure 7 This is a schematic diagram illustrating the mechanism by which the constructed wetland system of this invention removes total arsenic.

[0048] Figure 8 This is a partial metabolic pathway diagram of TPH removal in the constructed wetland system of this invention. Detailed Implementation

[0049] The present invention will now be described in further detail with reference to the accompanying drawings:

[0050] Constructed wetlands have attracted attention due to their advantages such as good treatment effect, simple process, low investment, and low operating cost. They are often used as the last part of advanced treatment and are known as the last line of defense in wastewater treatment. They remove pollutants through the synergistic effect of plants, microorganisms, and wetland substrates, utilizing physical sedimentation, chemical precipitation, adsorption, and biological metabolism. Although constructed wetlands have many advantages, there is still considerable room for improvement in removing persistent and complex pollutants such as petroleum hydrocarbons (TPH) and heavy metals. This is because traditional constructed wetlands mainly use iron ore and manganese ore as wetland substrate fillers to remove heavy metals and microorganisms. They utilize the iron and manganese cycle as intermediates to enhance electron transfer activity, working synergistically with microorganisms and plants to promote pollutant removal. At the same time, they utilize the co-precipitation, adsorption, and complexation of the substrate to remove pollutants from the water. However, Makino ore itself contains not only Fe(II) but also S(-II), so it can theoretically provide more electrons than iron ore and manganese ore, serving as an electron donor for the removal of organic micropollutants and heavy metals. Studies have shown that the Makino mine contains Fe(II) and S(-II), which can react with O2 under aerobic conditions to produce active free radicals such as sulfoxide radicals, which help degrade organic pollutants. At the same time, the presence of Fe and S can also promote the formation of stable minerals for heavy metals, which helps remove heavy metals.

[0051] like Figure 1 As shown, the present invention provides an artificial wetland treatment system, including an artificial wetland pool 1, wherein a support layer 2 and a substrate functional layer 3 are arranged sequentially from bottom to top in the artificial wetland pool 1, and wetland plants 4 are planted on the substrate functional layer 3.

[0052] In this invention, wetland plants 4 are directly planted on the substrate functional layer 3. The substrate functional layer 3 can provide some trace and macro elements for the growth of plants 4. At the same time, since the influent water quality of the wetland treatment system is Class B, it contains carbon, nitrogen, phosphorus and other elements necessary for plant growth, which can provide nutrients for plant growth. In addition, trace element solution is added during the operation of the wetland system to meet the needs of plant growth.

[0053] Preferably, the support layer 2 is composed of gravel with a particle size of 3-4 cm; the main function of the support layer 2 is to support the functional layer of the matrix and the distribution of water flow, and at the same time, it can provide an attachment site for microorganisms and promote the degradation and transformation of organic matter.

[0054] Preferably, the matrix functional layer 3 is a mixture of Makino ore (MA) and quartz sand (CT), wherein the mass ratio of quartz sand to Makino ore is 1 to 2:1, and the particle size of both Makino ore and quartz sand is 0.5-1 cm.

[0055] Both the Makino ore and the quartz sand have a particle size of 0.5-1 cm. On the one hand, keeping the particle size consistent with each other is conducive to uniform mixing; on the other hand, keeping the particle size consistent with each other is also conducive to the attachment and reproduction of microorganisms, ensuring the stable operation of the system.

[0056] In this invention, the matrix functional layer 3 is a mixture of Maginot ore and quartz sand, rather than using only Maginot ore. From an objective perspective, if only Maginot ore is used, on the one hand, the increased iron content would improve the physicochemical removal of heavy metals; however, on the other hand, the increased iron content would raise the concentration of dissolved iron. Since iron is a trace element for microorganisms, according to the optimal nutrient concentration law, excessive iron concentration can cause "iron poisoning" in microorganisms, thus inhibiting their growth and metabolic activities. Excessive concentration can even endanger the lives of microorganisms, ultimately affecting the removal of microorganisms and the valence transformation of heavy metals. Therefore, too much iron ore cannot be added. In a sense, the purpose of adding quartz sand is to dilute the iron in the wetland system, ensuring the stable operation of the system.

[0057] Based on the preliminary beaker tests, the mass ratio of quartz sand to Maginot ore in this invention is set to 1:1 to 2, as follows:

[0058] The water distribution adopts the Class B standard effluent from the sewage treatment plant, with an influent TPH concentration of 3 mg / L and TAs of 100 ug / L. The mass ratio of quartz sand to Makino ore is set as 1, 1:1, 2:1 and 5:1, respectively. The effluent effect is shown in Table 1.

[0059] Table 1. Preliminary Experimental Water Outflow Effect

[0060]

[0061]

[0062] As can be seen from Table 1, when the mass ratio of quartz sand to Maginot ore is 1:1 and 2:1 respectively, the effluent effect of TPH and TAs is relatively good. Among them, the effluent effect is the best when the mass ratio of the two is 1:1. Based on this, the mass ratio of quartz sand to Maginot ore is selected as 1 to 2:1 in this invention.

[0063] It should be noted that, from an engineering perspective, the preliminary experiment did not use Maginot ore as the entire matrix layer. This is because if Maginot ore were used exclusively, the cost of the entire system would increase significantly, which would be meaningless and worthless in practical engineering.

[0064] The wetland plants mentioned in section 4 include calamus, reed, water onion, rush, water celery, and canna lily.

[0065] The artificial wetland pool has an inlet 5 at the bottom of its side wall and an outlet 6 at the top of its side wall, with the water inlet being "bottom inlet, top outlet".

[0066] This invention relates to an artificial wetland treatment system that utilizes Maginot minerals as a wetland substrate to remove various pollutants. The principle is as follows: Maginot minerals first act as electron donors, promoting the biological activity of plants and microorganisms, thus facilitating the removal of organic and micropollutants. Simultaneously, they promote the oxidation-reduction of heavy metals through Fe and S cycles, altering the morphological characteristics of heavy metals. Second, Maginot minerals themselves have a certain specific surface area and contain Fe and S, enabling them to adsorb and complex with heavy metals while altering their morphology, resulting in the co-precipitation of Fe, S, and heavy metal ions, promoting the separation of heavy metals from wastewater. Finally, microorganisms and plants can also assimilate organic pollutants and heavy metals into their own cellular substances, further enhancing the pollutant removal capacity of the artificial wetland.

[0067] In a second aspect, the present invention provides a method for treating artificial wetlands, wherein the above-mentioned artificial wetland treatment system is used to treat wastewater. The wastewater is purified by passing through a support layer and a matrix functional layer in sequence before being discharged. Under the synergistic effect of plants, microorganisms and matrix, micro-organic pollutants and heavy metals are effectively removed.

[0068] like Figure 1 As shown, a peristaltic pump is used to send sewage into the constructed wetland system through the inlet. The inlet method is bottom inlet and top outlet. The sewage is purified by passing through the support layer and the matrix functional layer in sequence before being discharged.

[0069] Example 1

[0070] This embodiment is an artificial wetland treatment system, such as Figure 1 As shown, a polypropylene column with an inner diameter of 25cm and a height of 50cm is used as an artificial wetland pool 1. A support layer 2 and a matrix functional layer 3 are filled in the polypropylene column from bottom to top. Wetland plants 4 are planted on the matrix functional layer 3.

[0071] In this embodiment, the support layer 2 is composed of gravel with a particle size of 3-4 cm and a filling height of 5 cm; the matrix functional layer 3 is composed of quartz sand with a particle size of 0.5-1 cm and Makino ore MA with a particle size of 0.5-1 cm in a mass ratio of 1:1 and a filling height of 40 cm; the wetland plant is calamus; the inlet and outlet of the artificial wetland pond are respectively set at the lower and upper parts of the artificial wetland pond 1, and the water inlet adopts the "bottom inlet and top outlet" method.

[0072] Meanwhile, to facilitate the in-situ monitoring of the system's operation, a 4cm diameter PVC pipe is installed in the middle of the wetland device, with the axis of the PVC pipe coinciding with the axis of the artificial wetland pool, and multiple holes are provided on the upper side wall of the PVC pipe.

[0073] Example 2

[0074] The constructed wetland treatment system of Example 1 was used to remove total petroleum hydrocarbons (TPH) and heavy metal arsenic (As) from wastewater, which is referred to as the Makino ore group.

[0075] Specifically, the influent uses Class B effluent from a wastewater treatment plant (GB 18918-2002), and TPH and As are added simultaneously. During system operation, a peristaltic pump transports the wastewater containing TPH and As to the constructed wetland treatment system. The hydraulic retention time (HRT) is set to 3 days, and the hydraulic load is 0.306 m³ / s. 3 / m 2 (Period), the influent concentrations of TPH and TAs in the wastewater were 1 mg / L and 100 μg / L, respectively.

[0076] Comparative Example 1

[0077] Referring to Example 2, the difference is that the matrix functional layer filled in the artificial wetland pond is S- and Fe-free quartz sand CT with a particle size of 0.5-1cm, which is called quartz sand group.

[0078] Comparative Example 2

[0079] Referring to Example 2, the difference is that the matrix functional layer filled in the artificial wetland pond is magnetite MN without sulfur, and the particle size of the magnetite is 0.5-1cm, which is called magnetite group.

[0080] In the experiments of this invention embodiment, TPH was determined by gas chromatography, and As was determined by atomic fluorescence spectrophotometry.

[0081] After 120 days of stable operation, the average total arsenic and TPH concentrations in the effluent of the constructed wetland system in Comparative Example 1, filled with S- and Fe-free quartz sand as the matrix functional layer, were 37.9 μg / L and 0.16 mg / L, respectively, corresponding to TPH and As removal rates of 84 ± 4.9% and 62.1% ± 6.9%, respectively. In Comparative Example 2, filled with S-free magnetite as the matrix functional layer, the average total arsenic and TPH concentrations in the effluent were 25.8 μg / L and 0.1 mg / L, respectively, corresponding to TPH and As removal rates of 90% ± 6.7% and 74.2% ± 3.8%, respectively. Compared to Comparative Examples 1 and 2, Example 2 improved the removal rates of TPH and As by 8.8%, 2.8%, and 19.7%, 7.6%, respectively (e.g., ...). Figure 2a , Figure 2b , Figure 2c and Figure 2dAs shown in the figure, the concentrations were 92.8% ± 8.7% and 81.9% ± 2.4%, respectively, corresponding to average effluent concentrations of 0.072 mg / L and 18.10 μg / L. This indicates that the arsenic removal performance was satisfactory.

[0082] i) Compared to gravel such as quartz sand, using iron ore as a wetland substrate can better promote arsenic removal. This is because gravel such as quartz sand mainly utilizes adsorption in the process of removing arsenic, and its adsorption capacity is limited. In contrast, iron ore can dissolve Fe in this process. 2+ and Fe 3+ In addition to forming colloids such as Fe(OH)2 and Fe(OH)3 to promote adsorption, it can also promote the removal of arsenic from water through co-precipitation.

[0083] ii) The main forms of arsenic in the wastewater were As(III) and As(V), with the concentration of As(III) being 13% to 63% higher than that of As(V). This is because As(III) is more difficult to remove from water than As(V), leading to a greater retention of As(V) by the matrix. Furthermore, compared to the CT, MN, and MA groups, the MA group had the lowest content of As(V) and As(III) in the wastewater. Compared to the MN group, the MA group showed a 19.8% increase in As(III) removal efficiency and a 45.9% increase in As(V) removal efficiency. This indicates that different iron ores have different promoting effects on arsenic removal, with Maginotite being superior to magnetite. This may be related to the ore's structure and composition. The main component of magnetite is Fe3O4, where Fe plays a major role, while the main component of Maginotite is FeS. Besides Fe promoting arsenic removal, S may also be related to arsenic removal. 3+ SO4 2- All three can promote arsenic removal by forming a mineral similar to tooeleite (Fe6(AsO3)4(SO4)(OH)4·4H2O) through the iron-oxidizing bacteria At. ferrooxidans.

[0084] In terms of TPH removal, Maginot ore demonstrates a significant advantage. Firstly, besides adsorbing TPH, Maginot ore itself can also produce a Fenton-like effect to further oxidize TPH. Secondly, the Fe(III) / Fe(II) cycle present in Maginot ore can also promote TPH degradation. On one hand, Fe(II) is oxidized to Fe(III) by iron-sulfur oxidizing bacteria, and the generated electrons can be transferred to sulfate ions through microorganisms, reducing them to lower valence sulfur. On the other hand, Fe(III) can be reduced to Fe(II) by iron-reducing bacteria in anoxic / anaerobic zones using TPH as a nutrient, with TPH being the electron donor, thus removing TPH. Finally, the Maginot system itself also has a sulfur cycle. This is because FeS in Maginot ore has a high dissolved oxygen concentration (e.g., ... Figure 6 In the case shown, it will be rapidly oxidized to Fe. 3+ and SO4 2- The generated sulfate ions are quickly reduced to low-valence sulfur by sulfate-reducing bacteria in the anoxic / anaerobic zone. This low-valence sulfur is then oxidized by heterotrophic sulfur-oxidizing bacteria in the aerobic zone, with TPH as the electron donor. Simultaneously, heterotrophic microorganisms exist in the aerobic zone. Some TPH is converted from large organic molecules into smaller ones by extracellular hydrolytic enzymes secreted by these microorganisms. These smaller molecules, such as butyric acid and ethane, are transported to the microbial cells via group transport and are degraded through the tricarboxylic acid cycle by oxidases, dehydrogenases, and acylated coenzyme A synthase. Another portion of TPH directly enters the microbial cells and is degraded into CO2 and H2O through β-oxidation and the tricarboxylic acid cycle by oxidases, dehydrogenases, and acylated coenzyme A synthase. Figure 8 As shown in the figure, this enhances the removal effect of TPH. Metagenomic analysis revealed that the MA system contains biochemical dehydrogenases, methane monooxygenase, succinate dehydrogenase A (SDHA), monooxygenase, and long-chain fatty acid-CoA ligase. These enzymes play important roles in the degradation of petroleum hydrocarbons and are directly proportional to the degradation efficiency of petroleum hydrocarbons. Moreover, the enzyme content in the MA group is higher than that in the MN and CT groups, further explaining the high removal rate of TPH. In addition, the MA system also contains a high abundance of arsenite oxidase aioA, arsenate and arsenite transferases, and arsenic-resistant protein arsH, while the relative abundance of arsenate reductases arsA and arsB is relatively low. This indicates that the microorganisms in the MA system are more inclined to oxidize As(III) to As(V), and As(V) has relatively weaker mobility than As(III), thereby improving the retention of TAs by the substrate and increasing the removal rate of TAs (removal mechanism as shown in the figure). Figure 7 (As shown). This demonstrates that constructed wetland systems using Makino ore as the wetland substrate can efficiently remove various pollutants such as TPH and As.

[0085] To ensure the accuracy of the results, two sets were set up for each of Example 2, Comparative Example 1, and Comparative Example 2.

[0086] like Figures 3a to 3d As shown, the results of TPH and TAs in the functional layer of the substrate and wetland plants indicate that the wetland substrate mainly retains heavy metals, while wetland plants mainly absorb TPH. Furthermore, the Makino mine, as a wetland substrate, retained the most As. Related research suggests that plants accumulate ferric hydroxide in their roots to form iron spots, enhancing their tolerance to toxic substances and promoting the removal of rhizosphere toxins such as As pollution. Simultaneously, based on X-ray photoelectron spectroscopy (XPS) scanning results... Figures 4a to 4e As shown, sulfate, some sulfite, and Fe(II) and Fe(III) are present on the surface of the Makino ore matrix. Comparison with the Makino ore group and the magnetite group reveals that the removal of As on the Makino ore matrix surface involves adsorption, co-precipitation with Fe, and SO4. 2- The co-precipitation of Fe and As improves the removal rate of As.

[0087] Figures 5a to 5d The figures show the removal efficiency of the CT, MN, and MA systems for COD, TP, ammonia nitrogen, and nitrate nitrogen, respectively. As can be seen from the figures, the constructed wetland system using Maginot mine as the filling substrate exhibits higher COD and TP removal efficiency than the other systems. Based on the above analysis, it can be concluded that the constructed wetland system using Maginot mine as the filling substrate can simultaneously remove multiple types of pollutants. In practical applications, the pollutants in this example can be replaced with other pollutants, and the system parameters can be adjusted to meet the requirements for pollutant removal.

[0088] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0089] In the description of this invention, unless otherwise stated, the terms "upper," "lower," "left," "right," "inner," "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0090] The above technical solution is only one embodiment of the present invention. For those skilled in the art, based on the principles disclosed in the present invention, it is easy to make various types of improvements or modifications, and not limited to the technical solutions described in the specific embodiments of the present invention. Therefore, the foregoing description is only a preferred option and is not restrictive.

Claims

1. An artificial wetland treatment system, characterized in that, It includes an artificial wetland pond, in which a support layer and a substrate functional layer are arranged sequentially from bottom to top, and wetland plants are planted on the substrate functional layer.

2. The constructed wetland treatment system according to claim 1, characterized in that, The matrix functional layer is a mixture of Makino ore and quartz sand.

3. The constructed wetland treatment system according to claim 2, characterized in that, The mass ratio of quartz sand to Makino ore in the matrix functional layer is 1 to 2:

1.

4. The constructed wetland treatment system according to claim 2, characterized in that, The particle size of both the Makino ore and the quartz sand is 0.5-1 cm.

5. The constructed wetland treatment system according to claim 1, characterized in that, The support layer is composed of gravel with a particle size of 3-4 cm.

6. The constructed wetland treatment system according to claim 1, characterized in that, The wetland plants are one of the following: calamus, reed, water onion, rush, water celery, or canna.

7. The constructed wetland treatment system according to claim 1, characterized in that, The artificial wetland pool has an inlet at the bottom of its side wall and an outlet at the top of its side wall.

8. A method for treating constructed wetlands, characterized in that, Wastewater is treated using the constructed wetland treatment system as described in any one of claims 1-7. The wastewater flows sequentially through the support layer and the matrix functional layer for purification before being discharged. Under the synergistic effect of plants, microorganisms, and the matrix, micro-organic pollutants and heavy metals are effectively removed.

9. The constructed wetland treatment method as described in claim 8, characterized in that, The influent to the constructed wetland treatment system is the Class B standard effluent from the wastewater treatment plant.

10. The application of an artificial wetland treatment system as described in any one of claims 1-7 in wastewater treatment.

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