A tailwater wetland system for removing new contaminants

Abstract

The present application provides a tail water wetland system for removing new pollutants, comprising a pretreatment unit for treating suspended solids and microplastics, at least one first synergistic treatment unit and a second synergistic treatment unit for treating nitrogen and phosphorus nutrients and antibiotics in tail water, the pretreatment unit being connected to the first synergistic treatment unit through a water pipe, the first treatment unit being connected to the second treatment unit in series through a pipeline; the second synergistic treatment unit being connected to a surface flow wetland through a pipeline; the tail water of the sewage plant enters the pretreatment unit, the first synergistic treatment unit, the second synergistic treatment unit and the surface flow wetland in turn. The present application can efficiently remove microplastics and antibiotics in the tail water of the sewage plant while synergistically removing nitrogen and phosphorus nutrients through multi-stage treatment of the tail water of the sewage plant, embodying the green, ecological and environmental protection concept of the tail water wetland system.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of water pollution control and treatment, in particular to a tail water wetland system for removing new pollutants. BACKGROUND

[0002] New pollutants pose potential risks to the ecological environment and human health due to their biological toxicity, environmental persistence, and biological accumulation, and their environmental safety issues have been increasingly valued. The new pollutants widely concerned at home and abroad mainly include endocrine disruptors, persistent organic pollutants, antibiotics, and microplastics controlled by international conventions. Among them, antibiotics and microplastics, as two common types of new pollutants in water bodies, have received extensive attention.

[0003] Currently, microplastics in urban sewage treatment plants mainly migrate, and part of the microplastics enters the grid-intercepted sludge and the sand settled in the sand trap, while most of the microplastics enter the biochemical tank with the sewage and are adsorbed by activated sludge. In the sewage treatment process, microplastics are removed to some extent, but a certain amount of microplastics still exist in the tail water discharged in accordance with the standard, and since the total amount of tail water discharged from urban sewage treatment plants is large, the amount of microplastics entering the environmental water body with the tail water is also quite large. The removal of microplastics mainly adopts physical removal technology, chemical technology, and combined technology. The microplastic removal technology based on physical principles mainly includes membrane technology (filtration), magnetic separation technology, and sol-gel technology, etc. The chemical removal technology mainly includes photochemical oxidation, coagulation technology, electrocoagulation technology, and advanced oxidation technology, etc. The combined technology mainly includes ultrafiltration-coagulation combined technology, membrane bioreactor, etc. For the treatment of antibiotics in sewage, clarithromycin, erythromycin, roxithromycin, sulfamethoxazole, trimethoprim, ofloxacin, ciprofloxacin, and norfloxacin are relatively common in drug prescriptions and have stable structures, resulting in their relatively high detection frequency in sewage plants. At present, the treatment process of most sewage treatment plants has high removal effect on organic pollutants and nutrients such as nitrogen and phosphorus, but the removal of some antibiotics is not ideal, resulting in the concentration of the effluent reaching the level of μg / L, which endangers the environment. The conventional treatment process for removing antibiotics in sewage mainly removes the antibiotics in the sewage through physical adsorption, chemical oxidation, and ecological reduction principles. In recent years, with the attention to antibiotic pollution, new treatment technologies such as ultrasonic degradation, low-temperature plasma, soil infiltration system, and constructed wetland have emerged. When using constructed wetland to remove antibiotic pollutants, different wetland plants have different removal effects on different antibiotics, and the accumulation of antibiotics in different parts of the wetland plants also varies.

[0004] With existing technologies, the concentration of new pollutants (mainly antibiotics and microplastics) in wastewater effluent is high and the discharge volume is large. However, the effluent wetlands widely used for deep treatment of wastewater effluent do not consider the targeted removal of new pollutants, nor do they consider integrating water treatment technologies with better removal effects into the effluent wetland system. The existing effluent wetland technology has poor removal effect on new pollutants, which leads to a large amount of new pollutants entering the environmental water body and causing environmental risks.

[0005] Therefore, there is a need to provide an effluent wetland system that can remove new pollutants, efficiently remove microplastics and antibiotics from wastewater treatment plant effluent while simultaneously removing nitrogen and phosphorus, embodying the green, ecological, and environmentally friendly concept of effluent wetland systems. Summary of the Invention

[0006] In view of the shortcomings of the prior art described above, the technical problem to be solved by the present invention is to provide a tailwater wetland system for removing new pollutants, which can efficiently remove microplastics and antibiotics from wastewater treatment plant tailwater while simultaneously removing nitrogen and phosphorus, embodying the green, ecological and environmentally friendly concept of tailwater wetland system.

[0007] This invention proposes an effluent wetland system for removing new pollutants, comprising a pretreatment unit for treating suspended solids and microplastics, at least one first co-treatment unit and one second co-treatment unit for treating nitrogen, phosphorus, and antibiotics in the effluent. The pretreatment unit is connected to the first co-treatment unit via a water pipe, and the first and second treatment units are connected in series via pipelines. The second co-treatment unit is connected to a surface flow wetland via a pipeline. Wastewater effluent from the wastewater treatment plant sequentially enters the pretreatment unit, the first co-treatment unit, the second co-treatment unit, and the surface flow wetland.

[0008] Preferably, the first co-processing unit includes a first horizontal subsurface flow wetland and a first photocatalytic reaction tank, and the second co-processing unit includes a second horizontal subsurface flow wetland and a second photocatalytic reaction tank. One end of the first horizontal subsurface flow wetland is connected to the pretreatment unit, and the other end of the first horizontal subsurface flow wetland is connected to the first photocatalytic reaction tank. One end of the second horizontal subsurface flow wetland is connected to the first photocatalytic reaction tank, and the other end of the second horizontal subsurface flow wetland is connected to the second photocatalytic reaction tank.

[0009] Preferably, the first horizontal subsurface flow wetland includes a packing bed, in which an iron-carbon micro-electrolysis matrix is ​​arranged, the iron-carbon micro-electrolysis matrix being modified from a composite of carbon-based materials and iron-based materials; the second horizontal subsurface flow wetland has the same structure as the first horizontal subsurface flow wetland.

[0010] Preferably, the first photocatalytic reaction tank includes a tank body, a photocatalytic material, and a support frame. The support frame is fixed in the tank body, the photocatalytic material is disposed on the support frame and in contact with the water, and the photocatalytic material undergoes a photocatalytic reaction with natural light and / or an ultraviolet lamp on the support frame. The second photocatalytic reaction tank has the same structure as the first photocatalytic tank.

[0011] Preferably, the hydraulic retention time of both the first horizontal subsurface flow wetland and the second subsurface flow wetland is ≥4h.

[0012] Preferably, the hydraulic retention time of the surface flow wetland is ≥24h.

[0013] Preferably, the surface flow wetland includes emergent plants, which are preferably one or more combinations of reeds, cattails, calamus, canna lilies, water onions, and wild rice.

[0014] Preferably, the planting density of the emergent plants is ≥6 plants / m². 2 Each emergent plant must be at least 40cm tall.

[0015] Preferably, the surface flow wetland includes submerged plants, which are preferably one or more combinations of Vallisneria natans, Hydrilla verticillata, Ceratophyllum demersum, Myriophyllum spicatum, Potamogeton crispus, Elodea nuttallii, and Potamogeton crispus.

[0016] Preferably, the planting density of the submerged plants is ≥10 clumps / m². 2 Each clump must contain at least 10 plants, and each plant must be at least 15cm long.

[0017] As described above, the tailwater wetland system for removing new pollutants according to the present invention has the following beneficial effects:

[0018] This invention involves transporting wastewater effluent from a wastewater treatment plant to a pretreatment unit to treat suspended solids and microplastics. The pretreated effluent then flows through a pipeline into a first co-treatment unit to treat antibiotics and nitrogen and phosphorus nutrients. After treatment in the first co-treatment unit, the effluent flows through a pipeline into a second co-treatment unit, where new pollutants and nitrogen and phosphorus are further treated. The treated effluent is then discharged into a surface flow wetland for a predetermined retention time, after which it is either discharged into an environmental water body or reused. This invention utilizes multi-stage treatment of wastewater effluent to efficiently remove microplastics and antibiotics while simultaneously removing nitrogen and phosphorus nutrients, embodying the green, ecological, and environmentally friendly principles of wastewater wetland systems. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of an effluent wetland system for removing new pollutants according to an embodiment of the present invention.

[0020] Explanation of reference numerals in the attached figures:

[0021] 100. Pretreatment unit; 200. First co-treatment unit; 210. First horizontal subsurface flow wetland; 211. Packing bed; 212. Impermeable layer; 220. First photocatalytic reaction tank; 221. Tank body; 222. Photocatalytic material; 223. Support frame; 300. Second co-treatment unit; 310. Second horizontal subsurface flow wetland; 320. Second photocatalytic reaction tank; 400. Surface flow wetland. Detailed Implementation

[0022] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0023] It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings of this specification are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the scope of the invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed in this invention. Furthermore, the terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity and are not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0024] like Figure 1 As shown, this invention provides an embodiment of an effluent wetland system for removing new pollutants, including a pretreatment unit 100 for treating suspended solids and microplastics, at least one first co-treatment unit 200 and a second co-treatment unit 300 for treating nitrogen and phosphorus nutrients and antibiotics in the effluent. The pretreatment unit 100 is connected to the first co-treatment unit 200 via a pipeline. The first co-treatment unit 200 and the second co-treatment unit 300 are connected in series via a pipeline. The second co-treatment unit 300 is connected to a surface flow wetland 400 via a pipeline. The surface flow wetland 400 includes emergent plants, submerged plants, floating-leaved plants, aquatic plants (fish, shrimp, and snails), and soil. Wastewater effluent from the wastewater treatment plant sequentially enters the pretreatment unit 100, the first co-treatment unit 200, the second co-treatment unit 300, and the surface flow wetland 400. The pretreatment unit 100 is a water treatment facility with coagulation and sedimentation as its main function. The pretreatment unit 100 can be equipped with facilities such as a coagulation sedimentation tank, a coagulation-magnetic separation system, or a high-density sedimentation tank. It should be noted that, in order to ensure the efficiency of wastewater treatment, the present invention preferably includes a first co-processing unit and a second co-processing unit.

[0025] In operation, wastewater effluent from the wastewater treatment plant can be pumped or allowed to flow by gravity into the pretreatment unit 100 for enhanced pretreatment. The pretreatment unit 100 removes suspended solids and most microplastics from the wastewater. The remaining microplastics, along with nitrogen and phosphorus nutrients and antibiotics, flow with the effluent into the first co-treatment unit 200, where they are further treated. After treatment in the first co-treatment unit 200, the effluent still contains some microplastics, nitrogen and phosphorus nutrients, and antibiotics, which flow into the second co-treatment unit 300 via a water pipe. The second co-treatment unit 300 effectively removes most of the microplastics and antibiotics from the effluent, although a small amount of nitrogen and phosphorus nutrients may still be present. The treatment by the first and second co-treatment units 200 and 300 primarily enhances the process of converting long-chain antibiotics into short-chain compounds, which are then degraded by microorganisms. Finally, the treated effluent from the second co-treatment unit is discharged into the surface flow wetland, and the effluent is allowed to remain in the surface flow wetland 400 for at least 24 hours. This allows the emergent and dormant plants in the surface flow wetland 400 to fully absorb the small amount of nitrogen and phosphorus nutrients in the effluent, ensuring that the water quality discharged from the surface flow wetland meets the discharge standards.

[0026] Furthermore, the pretreatment unit 100 is preferably a magnetic separation system, which includes a dosing device, a coagulation tank, a separation device, and a recovery device. The dosing device uses coagulants such as PVC (polyvinyl chloride) and PAM (polyacrylamide) to aggregate suspended particles in the water into larger flocs. The dosing device, in conjunction with the coagulation tank and the separation device, achieves efficient removal of suspended matter. The separation device uses modified Fe3O4 (nano-iron powder) as a magnetic seed, which, combined with the magnetic force generated by a permanent magnet, adsorbs the iron-containing flocs. The flocs are adsorbed onto a rotating disc, and as the disc rotates, they are separated from the wastewater by a scraper, thus purifying the water. The recovery device includes a demagnetizer to treat the separated magnetic seed, allowing it to be demagnetized and recycled.

[0027] In one embodiment, such as Figure 1As shown, the first co-treatment unit 200 includes a first horizontal subsurface flow wetland 210 and a first photocatalytic reaction tank 220, and the second co-treatment unit 300 includes a second horizontal subsurface flow wetland 310 and a second photocatalytic reaction tank 320. One end of the first horizontal subsurface flow wetland 210 is connected to the pretreatment unit 100, and the other end is connected to the first photocatalytic reaction tank 220. One end of the second horizontal subsurface flow wetland 310 is connected to the first photocatalytic reaction tank 320, and the other end is connected to the second photocatalytic reaction tank 320. It should be noted that the first horizontal subsurface flow wetland 210 and the second horizontal subsurface flow wetland 220 have the same function, both removing microplastics and nitrogen and phosphorus nutrients from the effluent. The first photocatalytic reaction tank 220 and the second photocatalytic reaction tank 320 have the same function, both removing antibiotics from the effluent. Specifically, the effluent remains in the first-level subsurface flow wetland 210 and the second-level subsurface flow wetland 220 for more than 4 hours, allowing it to hold more water and thus increasing the water's residence time in the wetland system, which helps improve pollutant removal efficiency. The preferred depths of the first-level and second-level subsurface flow wetlands 210 and 220 are 2m to 4m to promote the metabolic activities of aerobic and anaerobic microorganisms, thereby achieving the removal of pollutants such as nitrogen and phosphorus. The preferred water depths of the first photocatalytic reaction tank 220 and the second photocatalytic reaction tank 320 are 1m to 2m to ensure that the water in the entire reaction tank receives sufficient light, thereby improving photocatalytic efficiency.

[0028] In operation, the wastewater effluent from the wastewater treatment plant, after being treated by the pretreatment unit 100, sequentially enters the first horizontal subsurface flow wetland 210, the first photocatalytic reactor 220, the second horizontal subsurface flow wetland 310, the second photocatalytic reactor 320, and the surface flow wetland 400. When the effluent enters the first horizontal subsurface flow wetland 210, on the one hand, the emergent plants on the first horizontal subsurface flow wetland 210 can absorb nitrogen and phosphorus nutrients from the wastewater through their roots and stems, thus playing a purification role; on the other hand, the first horizontal subsurface flow wetland 210 retains some microplastics within itself through adsorption and sedimentation. The remaining microplastics, nitrogen and phosphorus nutrients, and antibiotics enter the first photocatalytic reactor 310 with the effluent, where the antibiotics are treated. The residual microplastics, nitrogen and phosphorus nutrients, and antibiotics treated in the first photocatalytic reactor 310 are then introduced into the second horizontal subsurface flow wetland 310 and the second photocatalytic reactor 320 for further treatment, effectively removing these substances from the effluent. Finally, the treated effluent is discharged into the surface flow wetland 400 to maximize the nitrogen and phosphorus nutrient content in the effluent.

[0029] In one embodiment, the first horizontal subsurface flow wetland 210 includes a packing bed 211, an impermeable layer 212, and emergent plants. The impermeable layer 212 is located at the bottom to prevent pollutants in the upper packing bed from directly leaking to the lower layer, ensuring that wastewater has sufficient retention time in the packing bed. The packing bed 211 is located on top of the impermeable layer 212, and emergent plants are planted on the packing bed 211 at a planting density of ≥6 plants / m². 2 Each emergent plant is ≥40cm tall. One end of the packing bed 211 has an outlet, allowing the purified effluent to enter the next process stage. The packing bed 211 contains microorganisms; the emergent plants and microorganisms work synergistically to absorb nitrogen and phosphorus nutrients from the effluent. The packing bed 211 is equipped with packing material, preferably an iron-carbon microelectrolysis matrix. The iron-carbon microelectrolysis (IC-ME) matrix is ​​modified from carbon-based materials such as activated carbon (AC) and biochar (BC) with iron-based materials such as nano-zero-valent iron (nZVI) and iron oxides (e.g., Fe2O3, Fe3O4, FeOOH, and ferrous sulfide) through a composite process of pyrolysis, ball milling, precipitation, and thermal reduction, offering advantages of high efficiency and economy. The second-level subsurface flow wetland 310 has the same structure as the first-level subsurface flow wetland 210. The IC-ME matrix combines the advantages of both carbon-based and iron-based materials while also exhibiting a galvanic cell effect. In the IC-ME system, iron with a negative redox potential can form a micro galvanic cell with carbon, producing highly reactive products such as Fe(II), H2O2 and [H], which improves the removal efficiency of microplastics, nitrogen and phosphorus nutrients and antibiotics. At the same time, the many micro-current electric fields formed between iron and carbon further enhance the adsorption, reduction and microbial degradation.

[0030] Specifically, the pretreatment unit 100 can treat most microplastics and other suspended particulate matter. Nitrogen and phosphorus nutrients, antibiotics, and a small amount of remaining microplastics are carried by the wastewater through the first-level subsurface flow wetland 210 and the second-level subsurface flow wetland 310. Through adsorption, flocculation, and filtration, a two-stage degradation process is achieved, effectively retaining microplastics within the first-level subsurface flow wetland 210 and the second-level subsurface flow wetland 310. Simultaneously, emergent plants directly absorb nitrogen and phosphorus nutrients from the water through their roots and integrate them into their plant tissues through metabolic processes. Microorganisms in the packing bed convert nitrogen compounds through nitrification and denitrification, and plant roots also provide oxygen to promote nitrification. The surface of the iron-carbon electrolyte can adsorb some antibiotic molecules, reducing the antibiotic concentration in the water.

[0031] In one embodiment, the first photocatalytic reaction tank 220 includes a tank body 221, a photocatalytic material 222, and a support frame 223. The support frame 223 is fixed within the tank body 221, and the photocatalytic material 222 is disposed on the support frame 223 and in contact with the water. The photocatalytic material 222 undergoes a photocatalytic reaction with natural light and / or an ultraviolet lamp on the support frame 223. The second photocatalytic reaction tank 320 has the same structure as the first photocatalytic tank 220. The photocatalytic material 222 is preferably TiO2 or various modified materials based on TiO2. The tank body 221 is also provided with emergent plants, floating-leaved plants, etc., to assist in water purification.

[0032] During operation, the effluent enters either the first photocatalytic reactor 220 or the second photocatalytic reactor 320. During the photocatalytic treatment of antibiotics, electron-hole pairs are formed on the surface of the photocatalytic material. These electrons and holes migrate on the surface of the photocatalytic material and undergo a series of photochemical reactions, generating reactive oxygen species (ROS), such as hydroxyl radicals (·OH) and superoxide radicals (·O2-), thereby leading to the degradation of organic matter. The two-stage treatment in the first and second photocatalytic reactors 220 effectively removes antibiotics from the effluent, ensuring it meets external discharge requirements.

[0033] In one embodiment, the surface flow wetland 400 includes emergent plants and submerged plants. The water depth in the emergent plant planting area of ​​the surface flow wetland 400 is 0.1m to 0.5m, which helps the plant roots to respire and grow. The emergent plants are preferably one or more combinations of reeds, cattails, sweet flag, canna lilies, water onions, and wild rice. The planting density of the emergent plants is ≥6 plants / m². 2 Each emergent plant should be at least 40cm tall. The submerged plant planting area should be 1.5m–2.5m deep, allowing for underwater photosynthesis and providing a habitat for aquatic organisms. Preferred submerged plants include one or more of the following: *Vallisneria natans*, *Hydrilla verticillata*, *Ceratophyllum demersum*, *Myriophyllum spicatum*, *Potamogeton crispus*, *Elodea nuttallii*, and *Potamogeton crispus*. The planting density of submerged plants should be at least 10 clumps / m². 2 Each clump should contain at least 10 plants, and each plant should be at least 15cm long. It should be noted that the effluent after treatment in the second photocatalytic tank 320 enters the surface flow wetland 400. This effluent contains a small amount of nitrogen and phosphorus nutrients. The emergent and submerged plants in the surface flow wetland 400 can absorb the nitrogen and phosphorus nutrients in the effluent as much as possible, so that the content is lower than the discharge standard.

[0034] In one embodiment, the deep water area of ​​the surface flow wetland 400 can be equipped with a photovoltaic system to provide power to the pretreatment unit 100 and the first photocatalytic reaction tank 220 and the second photocatalytic reaction tank 320 at the front of the system, so as to make full use of the large water area of ​​the surface flow wetland and reduce the energy consumption of the wetland.

[0035] In summary, this invention treats wastewater effluent through multiple stages, effectively removing microplastics and antibiotics while simultaneously removing nitrogen and phosphorus nutrients, embodying the green, ecological, and environmentally friendly concept of wastewater wetland systems.

[0036] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A tailwater wetland system for removing new contaminants, characterized in that, The sewage treatment system comprises a pretreatment unit (100) for treating suspended solids and microplastics, at least one first synergistic treatment unit (200) for treating nitrogen and phosphorus nutrients and antibiotics in tail water, and a second synergistic treatment unit (300), the pretreatment unit (100) is connected to the first synergistic treatment unit (200) by a pipeline, the first synergistic treatment unit (200) and the second synergistic treatment unit (300) are connected in series by a pipeline, the second synergistic treatment unit (300) is connected to a surface flow wetland (400) by a pipeline, and tail water of a sewage treatment plant enters the pretreatment unit (100), the first synergistic treatment unit (200), the second synergistic treatment unit (300) and the surface flow wetland (400) in sequence. The first synergistic treatment unit (200) comprises a first horizontal subsurface flow wetland (210) and a first photocatalytic reaction tank (220), the second synergistic treatment unit (300) comprises a second horizontal subsurface flow wetland (310) and a second photocatalytic reaction tank (320), one end of the first horizontal subsurface flow wetland (210) is connected to the pretreatment unit (100), and the other end of the first horizontal subsurface flow wetland (210) is connected to the first photocatalytic reaction tank (220), one end of the second horizontal subsurface flow wetland (310) is connected to the first photocatalytic reaction tank (220), and the other end of the second horizontal subsurface flow wetland (310) is connected to the second photocatalytic reaction tank (320).

2. The emerging contaminant removal effluent wetland system of claim 1, wherein, The first horizontal subsurface flow wetland (210) comprises a filler bed (211) in which an iron-carbon microelectrolysis substrate is arranged, the iron-carbon microelectrolysis substrate is composed of a carbon-based material and an iron-based material, and the second horizontal subsurface flow wetland (310) has the same structure as the first horizontal subsurface flow wetland (210).

3. The emerging contaminant removal effluent wetland system of claim 1 or 2, wherein, The first photocatalytic reaction tank (220) comprises a tank body (221), a photocatalytic material (222) and a support frame (223), the support frame (223) is arranged in the tank body (221), the photocatalytic material (222) is arranged on the support frame (223) and is in contact with water, the photocatalytic material (222) performs photocatalytic reaction with natural light and / or an ultraviolet lamp on the support frame (223), and the second photocatalytic reaction tank (320) has the same structure as the first photocatalytic tank (220).

4. The emerging contaminant removal effluent wetland system of claim 1, wherein, The hydraulic retention time of the first horizontal subsurface flow wetland (210) and the second subsurface flow wetland (310) is greater than or equal to 4 h.

5. The emerging contaminant removal effluent wetland system of claim 1, wherein, The hydraulic retention time of the surface flow wetland (400) is greater than or equal to 24 h.

6. The emerging contaminant removal effluent wetland system of claim 1, wherein, The surface flow wetland (400) comprises emergent plants, and the emergent plants are preferably a combination of one or more of reed, cattail, alocasia, juncus, water onion and cattail.

7. The emerging contaminant removal effluent wetland system of claim 6, wherein, The planting density of the emergent plants is ≥ 6 plants / m 2 Each emergent plant has a height ≥ 40 cm.

8. The emerging contaminant removal effluent wetland system of claim 1 or 6, wherein, The surface flow wetland comprises submerged plants, and the submerged plants are preferably a combination of one or more of Vallisneria, Hydrilla verticillata, Ceratophyllum, Bolboschoenus, Potamogeton, Najas and Potamogeton crispus.

9. The emerging contaminant removal effluent wetland system of claim 8, wherein, The planting density of the submerged plant is ≥10 clusters / m 2 ≥10 plants per cluster, and each plant has a length ≥15 cm.

Images