Constructed wetland device and system for deeply purifying wastewater with low carbon-nitrogen ratio

Abstract

The invention relates to a constructed wetland device and system for deep purification of wastewater with low carbon nitrogen ratio, the constructed wetland device comprises a first shell, a second shell and a second shell which are detachably stacked in sequence, the first shell is provided with a first accommodating cavity with an opening at one end, and a first filler is arranged in the first accommodating cavity; the second shell is provided with a second containing cavity with openings in the two ends, one end of the second containing cavity communicates with the first containing cavity, and a second filler is arranged in the second containing cavity and comprises sulfur and steel slag; the third shell is provided with a third containing cavity with the two ends open, one end of the third containing cavity communicates with the other end of the second containing cavity, and third filler is arranged in the third containing cavity. The opening of the first containing cavity, the openings in the two ends of the second containing cavity and the openings in the two ends of the third containing cavity are all covered with partition layers, and the partition layers are provided with water permeable openings for sewage to pass through. The constructed wetland device not only can promote the denitrification process, but also can avoid the problems of blockage and difficulty in substrate replacement.

Description

Technical Field

[0001] The present application relates to the technical field of ecological environment protection, and in particular to an artificial wetland device and a system thereof for deep purification of low carbon-nitrogen ratio wastewater. Background Art

[0002] The artificial wetland system is a system that simulates natural wetlands. It uses a combination of microorganisms, plants, and substrates to effectively purify sewage through the synergistic effects of physics, chemistry, and biotechnology. Using artificial wetland systems to treat low-carbon-nitrogen ratio wastewater is a potential method. Low-carbon-nitrogen ratio wastewater mainly includes industrial sewage, agricultural sewage, domestic sewage, and landfill leachate.

[0003] However, in the process of treating low carbon-nitrogen ratio wastewater in artificial wetland systems, not only will the growth and metabolism of autotrophic microorganisms be slow, the denitrification process be limited, and the purification treatment effect be poor due to insufficient organic carbon sources, but the artificial wetland system will also have poor operating stability due to blockage and difficulty in substrate replacement. Summary of the invention

[0004] Based on this, it is necessary to provide an artificial wetland device and its system for deep purification of low carbon-nitrogen ratio wastewater to address the above-mentioned problems. The artificial wetland device can not only provide electron donors to autotrophic microorganisms when the carbon source is insufficient to promote the denitrification process and improve the purification treatment effect; it can also effectively avoid blockage and difficulty in substrate replacement.

[0005] The technical solution is as follows:

[0006] In a first aspect, the present application provides an artificial wetland device for deep purification of low carbon-nitrogen ratio wastewater, comprising a first functional unit, a second functional unit and a third functional unit arranged in sequence from bottom to top;

[0007] The first functional unit includes a first shell, the first shell is provided with a first accommodating cavity with an opening at one end, a first filler is arranged in the first accommodating cavity, a first matching portion is arranged at one end of the first shell close to the opening of the first accommodating cavity, and a water inlet connected to the first accommodating cavity is arranged at the other end;

[0008] The second functional unit includes a second shell, wherein the second shell is provided with a second matching portion detachably connected to the first matching portion at one end close to the first shell, and a third matching portion is provided at the other end, the second shell is provided with a second accommodating cavity with two ends opened, one end of the second accommodating cavity is connected to the first accommodating cavity, and a second filler is provided in the second accommodating cavity, and the second filler includes sulfur and steel slag;

[0009] The third functional unit comprises a third shell, wherein a fourth matching portion detachably connected to the third matching portion is provided at one end of the third shell close to the second shell, the third shell is provided with a third accommodating cavity with two ends opened, one end of the third accommodating cavity is communicated with the other end of the second accommodating cavity, a third filler is provided in the third accommodating cavity, and a water outlet is provided at one end of the third shell away from the second shell, and the water outlet is located at a side of the third filler away from the second shell;

[0010] The opening of the first accommodating chamber, the openings at both ends of the second accommodating chamber, and the openings at both ends of the third accommodating chamber are all covered with a separation layer, and the separation layer is provided with a water permeable opening for sewage to pass through.

[0011] In the above-mentioned artificial wetland device for deep purification of low carbon-nitrogen ratio wastewater, since the first shell and the second shell are stacked and detachably connected through the first matching part and the second matching part, the second shell and the third shell are stacked and detachably connected through the third matching part and the fourth matching part, the first accommodating chamber, the second accommodating chamber and the second accommodating chamber are connected in sequence and are respectively filled with the first filler, the second filler and the third filler, while the partition layer closes the opening of the corresponding accommodating chamber and allows sewage to flow through the partition layer from the permeable port. Therefore, when the sewage flows into the first accommodating chamber from the water inlet connected to the first accommodating chamber, the sewage can flow through the first filler, the second filler and the third filler in sequence to achieve gradual purification of the sewage, and then flow out of the artificial wetland device through the water outlet connected to the third accommodating chamber. Among them, since the first shell, the second shell and the third shell are stacked in sequence in a detachable manner, and the partition layer can limit the filler in the corresponding accommodating cavity to prevent the loss of the filler during disassembly, the assembly or disassembly of the first functional unit, the second functional unit and the third functional unit can be achieved through the cooperation between the first matching part and the second matching part and the cooperation between the third matching part and the fourth matching part. Therefore, the artificial wetland device has the characteristics of convenient disassembly and assembly, and each functional unit can be replaced at any time without damaging other functional units. This also makes it possible for the artificial wetland device to solve the problem of blockage by replacing local fillers or backwashing, and also enables the artificial wetland device to easily replace the filler matrix of each functional unit as needed to ensure the long-term stable operation of the artificial wetland device. In addition, since the second filler includes sulfur and steel slag, and sulfur can provide inorganic multi-electron donors that can promote denitrification and denitrification for autotrophic microorganisms under low carbon-nitrogen ratio conditions, and steel slag can strongly adsorb phosphates and precipitate metal ions, when the sewage to be purified is low carbon-nitrogen ratio wastewater, the sulfur in the second filler can provide additional electron donors to autotrophic microorganisms when the carbon source is insufficient, so as to promote the production and metabolism of autotrophic microorganisms and improve the denitrification efficiency of the artificial wetland device. And steel slag can effectively improve the total phosphorus removal rate of the artificial wetland device to achieve the effect of optimizing nitrogen and phosphorus removal. Therefore, the artificial wetland device can provide electron donors to autotrophic microorganisms in the absence of a carbon source to promote the denitrification process and improve the purification effect.

[0012] The technical solution is further described below:

[0013] In one embodiment, the second filler further comprises pyrite.

[0014] In one embodiment, the mass ratio of the sulfur, the pyrite and the steel slag is 5:0.5:0.5.

[0015] In one embodiment, a planting soil layer is further provided in the third accommodating chamber, the planting soil is provided on a side of the third filler away from the second shell, the artificial wetland device includes plants, and the plants are planted in the planting soil layer;

[0016] and / or, the first filler comprises stones and / or coarse sand;

[0017] And / or, the third filler includes one or more of ceramsite, zeolite and activated carbon.

[0018] In one embodiment, the artificial wetland device includes a gas replenishment component, the gas replenishment component includes a gas distribution device, a gas transmission pipe and a gas source, the gas distribution device is arranged on a side of the first accommodating chamber away from the second shell, the gas source is arranged outside the first shell, and the gas transmission pipe connects the gas distribution device and the gas source;

[0019] And / or, at least one waterproof layer is arranged in the second accommodating chamber, and the at least one waterproof layer divides the second accommodating chamber into at least two sub-functional areas, and the at least two sub-functional areas are arranged in sequence, and the second filler is arranged in each sub-functional area; the permeable openings of the two partition layers arranged in the second accommodating chamber are respectively connected to two of the at least two sub-functional areas located at opposite ends; each of the waterproof layers is provided with a connecting opening connecting two adjacent sub-functional areas, and all the sub-functional areas are connected in series in sequence through the connecting openings.

[0020] In one embodiment, one of the first mating portion and the second mating portion includes a first mating groove, and the other includes a first extension column, and the first extension column is detachably inserted into the first mating groove.

[0021] In one embodiment, the first mating groove includes a first plug-in groove and a first fixed groove that are connected to each other. The side wall of the first fixed groove is provided with a plurality of first convex strips, and the plurality of first convex strips are arranged at intervals along the depth direction of the first mating groove. The surface of the first extension column is provided with a plurality of first grooves passing through at both ends, and the plurality of first grooves are arranged at intervals along the extension direction of the first extension column. The first extension column has a first plug-in state that can be separated from the first mating groove and a first fixed state that can be locked and matched with the first mating groove. In the first plug-in state, the first extension column can be inserted into or withdrawn from the first plug-in groove; in the first fixed state, the first extension column is provided in the first fixed groove, and the plurality of first convex strips are snap-fitted to the plurality of first grooves one by one.

[0022] In the second aspect, the present application provides an artificial wetland system for deep purification of low carbon-nitrogen ratio wastewater, comprising an inlet pool, an inlet pipe, an outlet pool, an outlet pipe and a plurality of artificial wetland devices for deep purification of low carbon-nitrogen ratio wastewater according to any of the above items, wherein the plurality of artificial wetland devices are arranged in sequence and spaced apart, and the inlet of one of the two artificial wetland devices located at opposite ends of the plurality of artificial wetland devices is connected to the inlet pipe, and the outlet of the other artificial wetland device is connected to the outlet pipe, and all the artificial wetland devices are connected in series through connecting pipes to form a wetland unit row, the inlet pipe is also connected to the inlet pool, and the inlet pipe is provided with an inlet pump; the outlet pipe is also connected to the outlet pool, the inlet pool is used to store sewage, and the outlet pool is used to receive the sewage after purification.

[0023] In the above-mentioned artificial wetland system for deep purification of low carbon-nitrogen ratio wastewater, since the multiple artificial wetland devices arranged in series can be connected in series through the connecting pipe, when the water inlet pump is working, the sewage in the water inlet pool can enter the wetland unit row through the water inlet pipe, so that it can flow through different artificial wetland devices layer by layer and step by step, so as to achieve deep purification treatment by using different functional units in the artificial wetland device, and the purified sewage can flow into the outlet pool through the outlet pipe to complete a complete purification process. In addition, the series connection of multiple artificial wetland devices also enables the artificial wetland system to set different numbers of artificial wetland devices according to the pollution degree of sewage and the size of the terrain area to form a Chinese artificial wetland system, thereby ensuring that the artificial wetland system can purify sewage in complex terrain. Among them, since sulfur and steel slag are provided in the artificial wetland device, the artificial wetland system can provide electron donors that can promote the denitrification process to improve the purification effect. Since the first functional unit, the second functional unit and the third functional unit of the artificial wetland device are sequentially detachably stacked, the artificial wetland system constructed by the artificial wetland device has the characteristics of convenient assembly and disassembly and convenient movement, so the artificial wetland system can be used as soon as it is assembled and taken away as soon as it is unloaded, which effectively improves its flexibility. At the same time, when maintaining the artificial wetland system, the matrix in the artificial wetland system can be disassembled and replaced at any time to avoid blockage and difficulty in replacing the filler matrix, and alleviate the problem of increased blockage and reduced purification efficiency after the artificial wetland system has a long operation cycle.

[0024] In one embodiment, the number of the wetland unit rows, the number of the water inlet pipes, the number of the water inlet pumps and the number of the water outlet pipes are all multiple, and the multiple wetland unit rows are arranged along a first direction, the first direction is arranged at an angle to the arrangement direction of the multiple artificial wetland devices in the wetland unit row, and the wetland unit rows, the water inlet pipes, the water inlet pumps and the water outlet pipes are arranged one by one.

[0025] In one embodiment, the first direction is arranged at an acute angle to the arrangement direction of the plurality of artificial wetland devices in the wetland unit row, and in the first direction, the height difference between two adjacent wetland unit rows is between 5 cm and 20 cm. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the structure of an artificial wetland system in one embodiment.

[0027] Figure 2 FIG. 4 is a schematic diagram of the structure of a first functional unit in an embodiment.

[0028] Figure 3 FIG. 4 is a schematic diagram of the structure of a second functional unit in an embodiment.

[0029] Figure 4 4 is a schematic diagram of the structure of the third functional unit in one embodiment.

[0030] Figure 5 This is a structural schematic diagram of an autotrophic denitrification biological filter system.

[0031] Figure 6 for Figure 5 The figure shows a comparison of ammonia nitrogen concentration and ammonia nitrogen removal rate in the inlet and outlet water of the first group of devices, the second group of devices and the third group of devices in the autotrophic denitrification biological filter system.

[0032] Figure 7 for Figure 5 The figure shows a comparison of the nitrate nitrogen concentration and nitrate nitrogen removal rate in the inlet and outlet water of the first group of devices, the second group of devices and the third group of devices in the autotrophic denitrification biological filter system.

[0033] Figure 8 for Figure 5 The figure shows a comparison of the total nitrogen concentration and total nitrogen removal rate in the inlet and outlet water of the first group of devices, the second group of devices and the third group of devices in the autotrophic denitrification biological filter system.

[0034] Fig. 9 This is a schematic diagram of the structure of a small-scale test system of autotrophic denitrification artificial wetland.

[0035] Fig.10 for Fig. 9 The figure shows the change process of ammonia nitrogen concentration in the inlet and outlet water of the CW device and the SCW device in the autotrophic denitrification artificial wetland pilot system.

[0036] Fig.11 for Fig. 9 The figure shows a comparison of the nitrate nitrogen concentration and nitrate nitrogen removal rate in the inlet and outlet water of the CW device and the SCW device in the autotrophic denitrification artificial wetland pilot system.

[0037] Fig.12 for Fig. 9 The figure shows a comparison of the total nitrogen concentration and total nitrogen removal rate in the inlet and outlet water of the CW device and the SCW device in the autotrophic denitrification artificial wetland pilot system.

[0038] Description of reference numerals:

[0039] 100. artificial wetland system; 1. artificial wetland device; 11. first functional unit; 111. first shell; 112. first accommodating chamber; 113. first matching part; 12. second functional unit; 121. second shell; 122. second matching part; 123. third matching part; 124. second accommodating chamber; 13. third functional unit; 131. third shell; 132. third accommodating chamber; 133. fourth matching part; 14. partition layer; 2. water inlet pump; 3. water inlet pipe; 4. water inlet pool; 5. water outlet pool; 6. water outlet pipe; 7. connecting pipe; 8. plant; 9. drain pipe;

[0040] 200, autotrophic denitrification biofilter system; 201, sewage pool; 202, liquid inlet pipe; 203, liquid inlet pump; 204, liquid outlet pipe; 205, recovery pool; 206, group I device; 207, group II device; 208, group III device;

[0041] 300. Autotrophic denitrification artificial wetland pilot system; 301. Water supply tank; 302. Water pipe; 303. Water pump; 304. Drain pipe; 305. Water collection tank; 306. CW device; 307. SCW device; 308. Iris pumila. DETAILED DESCRIPTION

[0042] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0043] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0044] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0045] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0046] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0047] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0048] See also Figures 1 to 4 An artificial wetland device 1 for deep purification of low carbon-nitrogen ratio wastewater provided in one embodiment of the present application includes a first functional unit 11, a second functional unit 12 and a third functional unit 13 arranged in sequence from bottom to top. The first functional unit 11 includes a first shell 111, the first shell 111 is provided with a first accommodating chamber 112 with an opening at one end, a first filler is arranged in the first accommodating chamber 112, a first matching portion 113 is arranged at one end of the first shell 111 close to the opening of the first accommodating chamber 112, and a water inlet connected to the first accommodating chamber 112 is arranged at the other end. The second functional unit 12 includes a second shell 121. The second shell 121 is provided with a second matching portion 122 detachably connected to the first matching portion 113 at one end close to the first shell 111, and a third matching portion 123 at the other end. The second shell 121 is provided with a second accommodating chamber 124 with two ends open. One end of the second accommodating chamber 124 is connected to the first accommodating chamber 112. A second filler is arranged in the second accommodating chamber 124. The second filler includes sulfur and steel slag. The third functional unit 13 includes a third shell 131. The third shell 131 is provided with a fourth matching portion 133 detachably connected to the third matching portion 123 at one end close to the second shell 121. The third shell 131 is provided with a third accommodating chamber 132 with two ends open. One end of the third accommodating chamber 132 is connected to the other end of the second accommodating chamber 124. A third filler is arranged in the third accommodating chamber 132. A water outlet is provided at one end of the third shell 131 away from the second shell 121. The water outlet is located on the side of the third filler away from the second shell 121. The opening of the first accommodating chamber 112 , the openings at both ends of the second accommodating chamber 124 , and the openings at both ends of the third accommodating chamber 132 are all covered with a partition layer 14 , and a water permeable opening for sewage to pass through is opened on the partition layer 14 .

[0049] In the above-mentioned artificial wetland device 1 for deep purification of low carbon-nitrogen ratio wastewater, since the first shell 111 and the second shell 121 are stacked and detachably connected to the second matching part 113 and the second matching part 122, the second shell 121 and the third shell 131 are stacked and detachably connected to the fourth matching part 133 through the third matching part 123, the first accommodating chamber 112, the second accommodating chamber 124 and the second accommodating chamber 124 are connected in sequence and are respectively filled with the first filler, the second filler and the third filler in sequence, and the partition layer 14 closes the opening of the corresponding accommodating chamber while allowing sewage to flow through the partition layer 14 from the water permeable port. Therefore, when the sewage flows into the first accommodating chamber 112 from the water inlet connected to the first accommodating chamber 112, the sewage can flow through the first filler, the second filler and the third filler in sequence to achieve gradual purification of the sewage, and then flow out of the artificial wetland device 1 through the water outlet connected to the third accommodating chamber 132. Among them, since the first shell 111, the second shell 121 and the third shell 131 are detachably stacked in sequence, and the partition layer 14 can limit the filler in the corresponding accommodating cavity to prevent the loss of the filler during disassembly, the assembly or disassembly of the first functional unit 11, the second functional unit 12 and the third functional unit 13 can be achieved through the cooperation between the first matching part 113 and the second matching part 122 and the cooperation between the third matching part 123 and the fourth matching part 133. Therefore, the artificial wetland device 1 has the characteristics of convenient disassembly and assembly, and each functional unit can be replaced at any time without damaging other functional units. This also makes it possible for the artificial wetland device 1 to solve the problem of blockage by replacing local fillers or backwashing, and also enables the artificial wetland device 1 to conveniently replace the filler matrix of each functional unit as needed to ensure the long-term stable operation of the artificial wetland device 1. In addition, since the second filler includes sulfur and steel slag, and sulfur can provide inorganic multi-electron donors that can promote denitrification and denitrification for autotrophic microorganisms under low carbon-nitrogen ratio conditions, and steel slag can strongly adsorb phosphates and precipitate metal ions, when the sewage to be purified is low carbon-nitrogen ratio wastewater, the sulfur in the second filler can provide additional electron donors to autotrophic microorganisms when the carbon source is insufficient, so as to promote the production and metabolism of autotrophic microorganisms and improve the denitrification efficiency of the artificial wetland device 1. And steel slag can effectively improve the total phosphorus removal rate of the artificial wetland device 1 to achieve the effect of optimizing nitrogen and phosphorus removal. Therefore, the artificial wetland device 1 can provide electron donors to autotrophic microorganisms when the carbon source is insufficient, so as to promote the denitrification process and improve the purification effect.

[0050] Schematically, the first shell 111, the second shell 121 and the third shell 131 are all made of polyvinyl butyral, so that the first shell 111, the second shell 121 and the third shell 131 are all wear-resistant and corrosion-resistant, which is beneficial to ensure that the artificial wetland device 1 can operate effectively and stably for a long time.

[0051] Optionally, the shapes of the first shell 111, the second shell 121 and the third shell 131 can be set as needed, for example, they can all be cylindrical or rectangular. Preferably, the first shell 111, the second shell 121 and the third shell 131 are all cylindrical.

[0052] Optionally, the cross-section of the first accommodating cavity 112, the cross-section of the second accommodating cavity 124, and the cross-section of the third accommodating cavity 132 may be circular or rectangular. Preferably, the cross-section of the first accommodating cavity 112, the cross-section of the second accommodating cavity 124, and the cross-section of the third accommodating cavity 132 are all circular. Further, the height and inner diameter of the first accommodating cavity 112, the second accommodating cavity 124, and the third accommodating cavity 132 may be designed as required, for example, they are all cavities with a height of 40 cm and an inner diameter of 50 cm.

[0053] Illustratively, the partition layer 14 may include a nylon mesh, so that the partition layer 14 can effectively prevent the loss of fillers of each functional unit when the artificial wetland device 1 is disassembled, and has good water permeability to ensure that when the artificial wetland device 1 is working, sewage can flow into each accommodating cavity in sequence.

[0054] Illustratively, in the extension direction of the third accommodating cavity 132 , the distance between the water outlet and the third filler is 115 cm.

[0055] Schematically, the aperture of the water outlet and the aperture of the water inlet are both between 10 mm and 20 mm. Preferably, the aperture of the water outlet and the aperture of the water inlet are both 16 mm.

[0056] In one embodiment, the second filler also includes pyrite. In this way, both pyrite and sulfur can provide inorganic multi-electron donors to autotrophic microorganisms under low carbon-nitrogen ratio conditions to improve denitrification efficiency. Since the coupling of pyrite and steel slag can promote the formation of sulfur and the enrichment of sulfate-reducing bacteria, the sulfate generated by sulfur autotrophic denitrification can be reduced to sulfur by sulfate-reducing bacteria, and then can continue to provide electron donors for the reduction of nitrates under the action of sulfur-oxidizing bacteria, thereby maintaining the efficient autotrophic denitrification performance of the artificial wetland system 100. Therefore, when sulfur, pyrite and steel slag are combined to construct an inorganic multi-electron donor matrix, a growth medium can be provided for microorganisms in the artificial wetland to promote denitrification efficiency, and pollutants can also be removed by precipitation, filtration, adsorption, etc., effectively ensuring the purification treatment effect of the artificial wetland.

[0057] Furthermore, the mass ratio of sulfur, pyrite and steel slag is 5:0.5:0.5. When sulfur, pyrite and steel slag are combined in this mass ratio as the inorganic multi-electron donor matrix of the artificial wetland device 1, the optimized nitrogen removal and phosphorus removal effect can be achieved.

[0058] Specifically, in order to better illustrate that the inorganic multi-electron donor matrix includes sulfur, pyrite and steel slag, and the mass ratio of sulfur: pyrite: steel slag = 5:0.5:0.5 can promote denitrification efficiency and achieve the optimal nitrogen and phosphorus removal effect, Figure 4 A control experiment was conducted in the autotrophic denitrification biofilter system 200 shown in the figure. The autotrophic denitrification biofilter system 200 includes a sewage inlet tank 201, a recovery tank 205, three group I devices 206, three group II devices 207 and three group III devices 208. Each group I device 206, each group II device 207 and each group III device 208 are connected to the sewage inlet tank 201 through a liquid inlet pipe 202, and are connected to the recovery tank 205 through a liquid outlet pipe 204, so that the three group I devices 206, the three group II devices 207 and the three group III devices 208 are arranged in parallel. A liquid inlet pump 203 is arranged on each liquid inlet pipe 202. Among them, the filler matrix in each group I device 206 includes sulfur and pyrite, and the mass ratio is sulfur: pyrite = 5:1; the filler matrix in each group II device 207 includes sulfur and steel slag, and the mass ratio is sulfur: steel slag = 5:1; the filler matrix in each group III device 208 includes sulfur, pyrite and steel slag, and the mass ratio is sulfur: pyrite: steel slag = 5:0.5:0.5; sludge is provided in each device, and the volume ratio of the filler matrix to the sludge is 3.3:1, that is, 3.3 parts of filler matrix: 1 part of sludge. In addition, the hydraulic retention time of the three groups of devices is 120 minutes, and the operating temperature is 30°C.

[0059] like Figure 6 , Figure 7 and Figure 8 As shown, Figure 6 The ammonia nitrogen concentration and ammonia nitrogen removal rate of the inlet and outlet water of the first group of devices 206, the second group of devices 207 and the third group of devices 208 are shown. Figure 7 The nitrate nitrogen concentration and nitrate nitrogen removal rate of the inlet and outlet water of the first group of devices 206, the second group of devices 207 and the third group of devices 208 are shown. Figure 8The total nitrogen concentration and total nitrogen removal rate of the inlet and outlet water of the first group of devices 206, the second group of devices 207 and the third group of devices 208 are shown. According to the above three nitrogen removal diagrams, under the same conditions, the denitrification efficiency of the filler matrix in the third group of devices 208 is significantly higher than that of the first group of devices 206 and the second group of devices 207. Specifically, the filler matrix in the third group of devices 208 has an average nitrate nitrogen removal rate of 68.5% ± 3.68% and a maximum of 88.24% ± 0.47% in the stable period under the conditions of a hydraulic retention time of 120 min and 30°C; the average total nitrogen removal rate in the stable period can reach 43.42% ± 4.89% and a maximum of 54.77% ± 1.87%. Ammonia nitrogen is also partially removed, with an average removal rate of 13.38% ± 2.79%. Therefore, through this control experiment, it can be seen that when the matrix filler includes sulfur, pyrite and steel slag, and the mass ratio is m 硫磺 :m 黄铁矿 :m 钢渣 = 5:0.5:0.5, the effects of nitrogen removal and phosphorus removal can be effectively improved and optimized; and various purification processes such as precipitation, filtration, anaerobic biochemistry, facultative anoxic biochemistry, aerobic biochemistry, biological absorption and assimilation of pollutants in the multi-electron donor system can be made more coordinated and efficient.

[0060] Illustratively, when preparing the inorganic multi-electron donor matrix including sulfur, pyrite and steel slag, industrial waste pyrite, sulfur and steel slag can be selected as raw materials, wherein before preparation, the industrial waste pyrite needs to be crushed and screened to obtain uniform particle size; and the steel slag needs to be pickled and dried to remove harmful impurities. Furthermore, in one preparation method, sulfur particles can be used as the main component, pyrite and steel slag can be added in proportion, and then mixed evenly to obtain the inorganic multi-electron donor matrix. In another preparation method, the inorganic multi-electron donor matrix can also be prepared by boiling granulation. Specifically, sulfur powder is heated to 155-160°C in an oil bath to keep it in a low-viscosity state that is easy to operate; then a certain amount of pyrite or steel slag powder is added to the molten sulfur, and continuously stirred with an electric stirrer. After the mixture is evenly mixed, the temperature is reduced to 130-135°C for about 10 minutes, and then granulation is performed using a peristaltic pump and silicone hoses with different inner diameters; the mixed solution is dripped into tap water through the above-mentioned silicone hose, and quickly cooled to form spherical particles; after the spherical particles are cooled and dried, the inorganic multi-electron donor matrix is ​​obtained.

[0061] Optionally, the second filler may also include one or more of aluminum sludge, ferrous carbonate, phosphate, pumice and vermiculite. Among them, aluminum sludge, ferrous carbonate, phosphate, pumice, vermiculite and the like are all inorganic multi-electron donor materials that do not contain carbon. Placing one or more of them in the second filler can also help solve the problem of low denitrification efficiency.

[0062] Further, in one embodiment, if Figure 1 As shown, the third accommodating chamber 132 is also provided with a planting soil layer, which is provided on the side of the third filler away from the second shell 121, and the artificial wetland device 1 includes plants 8, which are planted in the planting soil layer. In this way, the plants 8 can be used to further absorb and utilize toxic and harmful substances in the sewage to ensure the effect of sewage purification treatment.

[0063] Illustratively, the planting soil layer may include limestone. The main component of limestone is calcium carbonate, which can provide a carrier for the growth of microorganisms and plants, and can also provide alkalinity, so the pH value of the liquid flowing in from the outlet can be adjusted. Furthermore, the thickness of the planting soil layer can be between 5 cm and 10 cm.

[0064] Illustratively, the plant 8 can be calamus. Calamus can absorb and utilize available nutrients in sewage, adsorb and enrich heavy metals and some toxic and harmful substances, and deliver oxygen to aerobic microorganisms in the root zone. This is conducive to enhancing and stabilizing the hydraulic transmission of the artificial wetland device 1. Furthermore, the number of plants 8, the height of plants 8, the planting density, and the planting depth can be designed as needed. For example, the number of plants 8 can be 2 or 4. Alternatively, the height of plant 8 can be 50 cm, the planting depth can be 10 cm, and the planting density can be 10 plants / m2.

[0065] In order to illustrate that the denitrification promoted by the inorganic multi-electron donor matrix composed of sulfur, pyrite and steel slag can improve the treatment efficiency of constructed wetlands, so that pollutants can be better removed under the coordinated action of artificial wetland plants, matrix and microorganisms, in Fig. 9A control test was conducted in the autotrophic denitrification artificial wetland pilot system 300 shown, which includes a water supply tank 301, a water collection tank 305, three CW devices 306 and three SCW devices 307. Each CW device 306 and each SCW device 307 are connected to the water supply tank 301 through a water pipe 302, and are connected to the water collection tank 305 through a drainage pipe 304, so that the three CW devices 306 and the three SCW devices 307 are arranged in parallel, and a water pump 303 is provided on each water pipe 302. The filler matrix in each CW device 306 includes two limestone layers and a CW functional layer disposed between the two limestone layers, and the CW functional layer is constructed by 35 cm fine sand and sludge in a volume ratio of 3.3:1; the filler matrix in each SCW device 307 includes two limestone layers and a SCW functional layer disposed between the two limestone layers, and the SCW functional layer includes a filler matrix and sludge in a mass ratio of sulfur: pyrite: steel slag = 5:0.5:0.5, and the volume ratio of the filler matrix to the sludge is 3.3:1. Among them, a common wetland emergent plant, Iris pumila 308, is planted on the top of each CW device 306 and each SCW device 307, and other working conditions are the same.

[0066] like Fig.10 , Fig.11 and Fig.12 As shown, Fig.10 The diagram shows the change process of ammonia nitrogen concentration when the CW device 306 and the SCW device 307 are inlet and outlet water. Fig.11 The figure shows the nitrate nitrogen concentration and nitrate nitrogen removal rate of the CW device 306 and the SCW device 307 when the water enters and leaves the device. Fig.12 The total nitrogen concentration and total nitrogen removal rate of the inlet and outlet water of the CW device 306 and the SCW device 307 are shown. According to the above three nitrogen removal diagrams, the denitrification efficiency of the SCW functional layer containing an inorganic multi-electron donor matrix is ​​significantly higher than that of the CW functional layer, and it can effectively remove nitrogen and phosphorus from sewage. Specifically, in the SCW device 307, the nitrate nitrogen removal rate in the stable period is as high as 87.51%±3.07%, and the maximum removal rate is 95.72%±2.27%; the total nitrogen removal rate in the stable period is 64.48%±6.06%, and the maximum removal rate is 71.72%±4.99%; among them, ammonia nitrogen is also partially removed in the stable period, and the maximum removal rate is 23.44%±11.09%. Therefore, through this control experiment, it can be known that when the matrix filler of the artificial wetland device 1 includes sulfur, pyrite and steel slag in a mass ratio of 5:0.5:0.5, and the common emergent plant in wetlands, Iris phellodendri 308, is planted, the artificial wetland device 1 can still effectively improve the sewage treatment efficiency, deeply optimize the conditions for nitrogen and phosphorus removal, and better remove pollutants under the triple coordinated action of artificial wetland plants, matrix and microorganisms.

[0067] Optionally, in one embodiment, the first filler includes stones and / or coarse sand. In the artificial wetland device 1, the first functional unit 11 is a water inlet unit, which is used to form a biofilm or provide an attachment carrier for microorganisms. Therefore, the first filler in the first functional unit 11 will first receive sewage, which requires the first filler to be able to remove large particles of suspended matter and sediments to reduce the load of subsequent treatment layers. The particles of stones and coarse sand are relatively large, which can effectively intercept large particles of suspended matter and sediments in sewage and play a role in preliminary filtration.

[0068] Optionally, in one embodiment, the third filler includes one or more of ceramsite, zeolite and activated carbon. In the artificial wetland device 1, the third functional unit 13 is a drainage unit, so it is necessary to set a matrix with a small particle size and a relatively large density in the third accommodating chamber 132 to effectively remove harmful substances in sewage by adsorption, filtration, ion exchange and the like, so as to improve the sewage purification efficiency. Among them, ceramsite has the characteristics of high porosity and good chemical stability, good acid and alkali corrosion resistance and long service life, which is conducive to the attachment of microorganisms and can provide good filtering effect. Zeolite has good ion exchange performance and adsorption performance, can effectively remove ammonia nitrogen and phosphate, and also helps the growth and reproduction of microorganisms. Activated carbon has good adsorption performance and can effectively adsorb pollutants such as organic matter and heavy metal ions in sewage, so a combination of ceramsite, zeolite and activated carbon, or any one of the three can be set as the matrix of the third filler.

[0069] Schematically, the third filler can also include gravel, ceramic sand, expanded perlite and concrete blocks, etc. Among them, gravel has good drainage and air permeability, and can provide different particle sizes to meet different filtration needs; coarse gravel can be used for bottom support, providing biological attachment and medium filtration; ceramsite, ceramic sand and other silicate products have high porosity and good chemical stability, good acid and alkali corrosion resistance, long service life, and are conducive to microbial attachment, while providing good filtration effect; expanded perlite is light and has extremely high porosity, has good adsorption and drainage properties, and can effectively improve the water permeability and air permeability of the wetland system; concrete blocks are strong and durable, can withstand large water pressure and mechanical shock, and provide stable structural support.

[0070] In one embodiment, the artificial wetland device 1 includes a gas supplement component, which includes a gas distribution device, a gas transmission pipe and a gas source. The gas distribution device is arranged on the side of the first accommodating chamber 112 away from the second shell 121, and the gas source is arranged outside the first shell 111. The gas transmission pipe connects the gas distribution device and the gas source. In this way, the gas source can transmit the gas to the gas distribution device through the gas transmission pipe, so that the gas distribution device can transmit the gas to the first filler, so as to use the gas to promote the occurrence of aerobic biochemistry or anaerobic biochemistry, and provide conditions for microorganisms to remove different types of pollutants.

[0071] Illustratively, the air distribution device includes but is not limited to an open-hole air distribution pipe, a microporous aeration pipe, an aeration plate, and the like.

[0072] Schematically, a replenishing port is provided on the gas delivery pipe, and the replenishing port is used to allow solution or solid to enter the gas delivery pipe. In this way, the first accommodating chamber 112 can be replenished with regulating substances such as solution or solid by means of the gas distribution pipeline.

[0073] In one embodiment, at least one waterproof layer is provided in the second accommodating chamber 124, and the at least one waterproof layer divides the second accommodating chamber 124 into at least two sub-functional areas, and the at least two sub-functional areas are arranged in sequence, and a second filler is provided in each sub-functional area. The water-permeable openings of the two partition layers 14 provided in the second accommodating chamber 124 are respectively connected to two sub-functional areas located at opposite ends of the at least two sub-functional areas, and each waterproof layer is provided with a connecting opening connecting two adjacent sub-functional areas, and all sub-functional areas are connected in series in sequence through the connecting openings. In this way, the sewage can flow through each sub-functional area in sequence along a predetermined path, so that the fillers in each functional area can purify the sewage multiple times, thereby increasing the hydraulic retention time, which is conducive to improving the effect of the purification treatment.

[0074] Furthermore, in one embodiment, all waterproof layers are arranged at intervals with the partition layer 14 provided in the second accommodating cavity 124, so that all sub-functional areas are arranged along the extension direction of the second accommodating cavity 124, that is, at least one waterproof layer divides the second accommodating cavity 124 into at least two vertical sub-functional areas; wherein, the permeable openings of the two partition layers 14 provided in the second accommodating cavity 124 are respectively connected to two sub-functional areas located at opposite ends of the at least two sub-functional areas, and each waterproof layer is provided with a connecting opening connecting two adjacent sub-functional areas, and all sub-functional areas are connected in series in sequence through the connecting openings.

[0075] In another embodiment, both ends of all waterproof layers are respectively connected to the partition layers 14 provided at both ends of the second accommodating cavity 124, so that the projections of all sub-functional areas on the cross-section of the second shell 121 are arranged side by side, that is, at least one waterproof layer divides the second accommodating cavity 124 into at least two horizontal sub-functional areas; wherein, the water-permeable openings of the two partition layers 14 provided in the second accommodating cavity 124 are respectively connected to two sub-functional areas located at opposite ends of the at least two sub-functional areas, and each waterproof layer is provided with a connecting opening connecting two adjacent sub-functional areas, and all sub-functional areas are connected in series in sequence through the connecting openings.

[0076] In one embodiment, in combination Figure 2 and Figure 3As shown, one of the first matching portion 113 and the second matching portion 122 includes a first matching groove, and the other includes a first extension column, and the first extension column is detachably inserted into the first matching groove. In this way, the first shell 111 and the second shell 121 can be conveniently assembled and disassembled through the cooperation of the first matching groove and the first extension column, so that the artificial wetland device 1 can efficiently and quickly solve the blockage problem that occurs during the actual operation process by replacing local fillers, backwashing, etc., thereby improving the flexibility and controllability of the artificial wetland device 1, reducing maintenance costs and improving maintenance efficiency. In addition, the provision of the first matching groove and the first extension column eliminates the need for metal hardware connection between the first shell 111 and the second shell 121, that is, it has higher load-bearing and seismic resistance, which also enables the artificial wetland device 1 to maintain structural stability under humidity changes.

[0077] Furthermore, the first mating groove includes a first plug-in groove and a first fixed groove that are connected to each other. The side wall of the first fixed groove is provided with a plurality of first convex strips, and the plurality of first convex strips are arranged at intervals along the depth direction of the first mating groove. The surface of the first extension column is provided with a plurality of first grooves passing through both ends, and the plurality of first grooves are arranged at intervals along the extension direction of the first extension column. The first extension column has a first plug-in state that can be separated from the first mating groove and a first fixed state that can be locked and matched with the first mating groove. In the first plug-in state, the first extension column can be inserted into or withdrawn from the first plug-in groove; in the first fixed state, the first extension column is arranged in the first fixed groove, and the plurality of first convex strips are correspondingly engaged with the plurality of first grooves. In this way, in the first plug-in state, the first functional unit 11 and the second functional unit 12 can be conveniently assembled and disassembled through the cooperation of the first extension column and the first plug-in groove, so as to ensure that the artificial wetland device 1 can be used as soon as it is assembled and taken away as soon as it is unloaded, and at the same time, the artificial wetland device 1 can effectively avoid the problems of blockage and matrix replacement; and in the first fixed state, the first functional unit 11 and the second functional unit 12 can maintain a locked state by utilizing the snap-fit ​​cooperation of the first convex strip and the first groove, so as to avoid the first functional unit 11 and the second functional unit 12 from being separated due to external force interference, thereby improving the seismic resistance between the first functional unit 11 and the second functional unit 12, which is beneficial to improving the stability and reliability of the artificial wetland device 1.

[0078] Schematically, the first shell 111 and the second shell 121 are both cylindrical, the first mating groove is an arc groove, and the first extension portion switches between the first fixed state and the first plug-in state by rotating relative to the first mating groove; or, the first shell 111 and the second shell 121 are both rectangular, the first mating groove is a straight groove, and the first extension portion switches between the first fixed state and the first plug-in state by sliding relative to the first mating groove.

[0079] Indicative, combined Figure 2 and Figure 3 As shown, the number of the first matching parts 113 and the number of the second matching parts 122 are both multiple, and the multiple first matching parts are arranged at intervals along the circumference of the first shell 111, and the first matching parts 113 are detachably connected to the second matching parts 122 in a one-to-one correspondence.

[0080] In one embodiment, Figure 3 and Figure 4 As shown, one of the third matching part 123 and the fourth matching part 133 includes a second matching groove, and the other includes a second extension column, and the second extension column is detachably inserted into the second matching groove. In this way, the second shell 121 and the third shell 131 can be conveniently assembled and disassembled through the cooperation of the second matching groove and the second extension column, so that the artificial wetland device 1 can efficiently and quickly solve the blockage problem that occurs during the actual operation process by replacing local fillers, backwashing, etc., thereby improving the flexibility and controllability of the artificial wetland device 1, reducing maintenance costs and improving maintenance efficiency. In addition, the provision of the second matching groove and the second extension column eliminates the need for metal hardware connection between the second shell 121 and the third shell 131, that is, it has high load-bearing and seismic resistance, which also enables the artificial wetland device 1 to maintain structural stability under humidity changes.

[0081] Furthermore, the second mating groove includes a second plug-in groove and a second fixed groove that are connected to each other. The side wall of the second fixed groove is provided with a plurality of second convex strips, and the plurality of second convex strips are arranged at intervals along the depth direction of the second mating groove. The surface of the second extension column is provided with a plurality of second grooves with both ends passing through, and the plurality of second grooves are arranged at intervals along the extension direction of the second extension column. The second extension column has a second plug-in state that can be separated from the second mating groove and a second fixed state that can be locked and matched with the second mating groove. In the second plug-in state, the second extension column can be inserted into or withdrawn from the second plug-in groove; in the second fixed state, the second extension column is arranged in the second fixed groove, and the plurality of second convex strips are correspondingly engaged with the plurality of second grooves. In this way, in the second plug-in state, the second functional unit 12 and the third functional unit 13 can be conveniently assembled and disassembled through the cooperation of the second extension column and the second plug-in groove, so as to ensure that the artificial wetland device 1 can be used as soon as it is assembled and taken away as soon as it is unloaded, and at the same time, the artificial wetland device 1 can effectively avoid the problems of blockage and matrix replacement; and in the second fixed state, the second functional unit 12 and the third functional unit 13 can maintain a locked state by utilizing the snap-fit ​​cooperation of the second convex strip and the second groove, so as to avoid the second functional unit 12 and the third functional unit 13 from being separated due to external force interference, thereby improving the seismic resistance between the second functional unit 12 and the third functional unit 13, and thus helping to improve the stability and reliability of the artificial wetland device 1.

[0082] Schematically, the second shell 121 and the third shell 131 are both cylindrical, the second mating groove is an arc groove, and the second extension portion switches between the second fixed state and the second plug-in state by rotating relative to the second mating groove; or, the second shell 121 and the third shell 131 are both rectangular, the second mating groove is a straight groove, and the second extension portion switches between the second fixed state and the second plug-in state by sliding relative to the second mating groove.

[0083] Indicative, such as Figure 3 and Figure 4 As shown, the number of the third matching parts 123 and the number of the fourth matching parts 133 are both multiple, and the multiple third matching parts 123 are arranged at intervals along the circumference of the second shell 121, and the third matching parts 123 are detachably connected to the fourth matching parts 133 in a one-to-one correspondence.

[0084] The present application also provides an artificial wetland system 100 for deep purification of low carbon-nitrogen ratio wastewater, comprising an inlet pool 4, an inlet pipe 3, an outlet pool 5, an outlet pipe 6 and a plurality of artificial wetland devices 1 for deep purification of low carbon-nitrogen ratio wastewater in any of the embodiments, wherein the plurality of artificial wetland devices 1 are arranged in sequence and spaced apart, the inlet of one of the two artificial wetland devices 1 located at opposite ends of the plurality of artificial wetland devices 1 is connected to the inlet pipe 3, the outlet of the other artificial wetland device 1 is connected to the outlet pipe 6, all the artificial wetland devices 1 are connected in series through a connecting pipe 7 to form a wetland unit row, the inlet pipe 3 is also connected to the inlet pool 4, and the inlet pipe 3 is provided with an inlet pump 2, the outlet pipe 6 is also connected to the outlet pool 5, the inlet pool 4 is used to store sewage, and the outlet pool 5 is used to receive the sewage after purification.

[0085] In the above-mentioned artificial wetland system 100 for deep purification of low carbon nitrogen ratio wastewater, since the multiple artificial wetland devices 1 arranged in series can be connected in series through the connecting pipe 7, when the water inlet pump 2 is working, the sewage in the water inlet pool 4 can enter the wetland unit row through the water inlet pipe 3, so that it can flow through different artificial wetland devices 1 layer by layer and step by step, so as to realize deep purification treatment by using different functional units in the artificial wetland device 1, and the purified sewage can flow into the water outlet pool 5 through the outlet pipe 6 to complete a complete purification process. In addition, the series connection of multiple artificial wetland devices 1 also enables the artificial wetland system 100 to set different numbers of artificial wetland devices 1 according to the pollution degree of sewage and the size of the terrain area to form a Chinese artificial wetland system 100, so as to ensure that the artificial wetland system 100 can purify sewage in complex terrain. Among them, since sulfur and steel slag are provided in the artificial wetland device 1, the artificial wetland system 100 can provide electron donors that can promote the denitrification process to improve the purification effect. Since the first functional unit 11, the second functional unit 12 and the third functional unit 13 of the artificial wetland device 1 are sequentially detachably stacked, the artificial wetland system 100 constructed by the artificial wetland device 1 has the characteristics of convenient assembly and disassembly and convenient movement, so the artificial wetland system 100 can be used as soon as it is assembled and taken away as soon as it is unloaded, which effectively improves its flexibility. At the same time, when maintaining the artificial wetland system 100, the matrix in the artificial wetland system 100 can be disassembled and replaced at any time to avoid clogging and difficulty in replacing the filler matrix, and alleviate the problem of aggravated clogging and reduced purification efficiency after the artificial wetland system 100 has a long operation cycle.

[0086] Illustratively, the sewage in the water inlet pool 4 can be low carbon-nitrogen ratio wastewater from domestic sewage in villages and towns, extraction of river water bodies, rainwater and sewage mixed flow, landfill leachate, industrial wastewater, etc.

[0087] Illustratively, when the decontamination effect in the effluent pool 5 does not meet the standard, the water in the effluent pool 5 can be re-input into the artificial wetland system 100, so as to complete the deep purification treatment of the low carbon-nitrogen ratio wastewater through circulation treatment measures such as secondary water inflow.

[0088] Schematically, the artificial wetland system 100 further includes a plurality of drain pipes 9, one end of the drain pipes 9 is connected to the water outlet pool 5, and the other end is connected to the first accommodating chamber 112 of the artificial wetland device 1, and the plurality of drain pipes 9 are arranged in a one-to-one correspondence with the plurality of artificial wetland devices 1. In this way, when the artificial wetland device 1 is dismantled, the sewage in the artificial wetland device 1 can be discharged through the drain pipes 9, so as to avoid the sewage being retained in the artificial wetland device 1 for a long time, so as to affect the replacement or maintenance of the functional units in the artificial wetland device 1.

[0089] Schematically, the water inlet of the artificial wetland device 1 is provided with an inlet pipe, and the water outlet is provided with an outlet pipe. The inlet pipe is used to connect with the inlet pipe 3 or the connecting pipe 7, and the outlet pipe is used to connect with the outlet pipe 6 or the connecting pipe 7.

[0090] Further, in one embodiment, the number of wetland unit rows, the number of water inlet pipes 3, the number of water inlet pumps 2, and the number of water outlet pipes 6 are all multiple, and the multiple wetland unit rows are arranged along a first direction, and the first direction is arranged at an angle to the arrangement direction of the multiple artificial wetland devices 1 in the wetland unit row, and the wetland unit row, the water inlet pipe 3, the water inlet pump 2, and the water outlet pipe 6 are arranged one by one. In this way, multiple artificial wetland devices 1 can be connected in series and parallel to construct a pilot or large-scale artificial wetland system 100, so as to reasonably and flexibly assemble the system according to the size of the terrain area, optimize the system operating conditions, and ensure that low carbon-nitrogen ratio wastewater can be deeply treated to obtain stable and efficient purification efficiency.

[0091] Optionally, in one embodiment, the first direction is arranged at an acute angle to the arrangement direction of the plurality of artificial wetland devices in the wetland unit row, and in the first direction, the height difference between two adjacent wetland unit rows is between 5 cm and 20 cm. In this way, when the terrain is a slope with a certain slope or a trapezoidal shape, different trapezoidal artificial wetland systems 100 can be flexibly constructed by connecting a plurality of artificial wetland devices 1 in series and parallel, so that the layout of the artificial wetland system 100 can be adapted to the pollution degree of the sewage, the terrain form and the slope, effectively ensuring the effect of sewage purification treatment, and also increasing the hydraulic retention time, hydraulic load or landscape effect.

[0092] Preferably, in the first direction, the height difference between two adjacent wetland unit rows is between 5 cm and 10 cm.

[0093] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0094] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. An artificial wetland device for deep purification of low carbon-nitrogen ratio wastewater, characterized in that: It includes a first functional unit, a second functional unit and a third functional unit which are arranged in sequence from bottom to top; The first functional unit includes a first shell, the first shell is provided with a first accommodating cavity with an opening at one end, a first filler is arranged in the first accommodating cavity, a first matching portion is arranged at one end of the first shell close to the opening of the first accommodating cavity, and a water inlet connected to the first accommodating cavity is arranged at the other end; The second functional unit includes a second shell, wherein the second shell is provided with a second matching portion detachably connected to the first matching portion at one end close to the first shell, and a third matching portion is provided at the other end, the second shell is provided with a second accommodating cavity with two ends opened, one end of the second accommodating cavity is connected to the first accommodating cavity, and a second filler is provided in the second accommodating cavity, and the second filler includes sulfur and steel slag; The third functional unit comprises a third shell, wherein a fourth matching portion detachably connected to the third matching portion is provided at one end of the third shell close to the second shell, the third shell is provided with a third accommodating cavity with two ends opened, one end of the third accommodating cavity is communicated with the other end of the second accommodating cavity, a third filler is provided in the third accommodating cavity, and a water outlet is provided at one end of the third shell away from the second shell, and the water outlet is located at a side of the third filler away from the second shell; The opening of the first accommodating chamber, the openings at both ends of the second accommodating chamber, and the openings at both ends of the third accommodating chamber are all covered with a separation layer, and the separation layer is provided with a water permeable opening for sewage to pass through.

2. The artificial wetland device for deep purification of low carbon-nitrogen ratio wastewater according to claim 1, characterized in that: The second filler also includes pyrite.

3. The artificial wetland device for deep purification of low carbon-nitrogen ratio wastewater according to claim 2, characterized in that: The mass ratio of the sulfur, the pyrite and the steel slag is 5:0.5:0.

5.

4. The artificial wetland device for deep purification of low carbon-nitrogen ratio wastewater according to claim 3, characterized in that: A planting soil layer is further provided in the third accommodating chamber, the planting soil is provided on a side of the third filler away from the second shell, the artificial wetland device includes plants, and the plants are planted in the planting soil layer; and / or, the first filler comprises stones and / or coarse sand; And / or, the third filler includes one or more of ceramsite, zeolite and activated carbon.

5. The artificial wetland device for deep purification of low carbon-nitrogen ratio wastewater according to any one of claims 1 to 4, characterized in that: The artificial wetland device includes a gas supplement component, which includes a gas distribution device, a gas transmission pipe and a gas source, wherein the gas distribution device is arranged on a side of the first accommodating chamber away from the second shell, the gas source is arranged outside the first shell, and the gas transmission pipe connects the gas distribution device and the gas source; And / or, at least one waterproof layer is arranged in the second accommodating chamber, and the at least one waterproof layer divides the second accommodating chamber into at least two sub-functional areas, and the at least two sub-functional areas are arranged in sequence, and the second filler is arranged in each sub-functional area; the permeable openings of the two partition layers arranged in the second accommodating chamber are respectively connected to two of the at least two sub-functional areas located at opposite ends; each of the waterproof layers is provided with a connecting opening connecting two adjacent sub-functional areas, and all the sub-functional areas are connected in series in sequence through the connecting openings.

6. The artificial wetland device for deep purification of low carbon-nitrogen ratio wastewater according to any one of claims 1 to 4, characterized in that: One of the first matching portion and the second matching portion includes a first matching groove, and the other includes a first extension column, and the first extension column is detachably inserted into the first matching groove.

7. The artificial wetland device for deep purification of low carbon-nitrogen ratio wastewater according to claim 6, characterized in that: The first mating groove includes a first plug-in groove and a first fixed groove that are connected to each other. The side wall of the first fixed groove is provided with a plurality of first convex strips, and the plurality of first convex strips are arranged at intervals along the depth direction of the first mating groove. The surface of the first extension column is provided with a plurality of first grooves passing through both ends, and the plurality of first grooves are arranged at intervals along the extension direction of the first extension column. The first extension column has a first plug-in state that can be separated from the first mating groove and a first fixed state that can be locked and matched with the first mating groove. In the first plug-in state, the first extension column can be inserted into or withdrawn from the first plug-in groove; in the first fixed state, the first extension column is arranged in the first fixed groove, and the plurality of first convex strips are correspondingly engaged with the plurality of first grooves.

8. An artificial wetland system for deep purification of low carbon-nitrogen ratio wastewater, characterized in that: It comprises an inlet pool, an inlet pipe, an outlet pool, an outlet pipe and a plurality of artificial wetland devices for deep purification of low carbon-nitrogen ratio wastewater as described in any one of claims 1 to 7, wherein the plurality of artificial wetland devices are arranged in sequence and spaced apart, the inlet of one of the two artificial wetland devices located at opposite ends of the plurality of artificial wetland devices is connected to the inlet pipe, and the outlet of the other artificial wetland device is connected to the outlet pipe, all the artificial wetland devices are connected in series through connecting pipes to form a wetland unit row, the inlet pipe is also connected to the inlet pool, and the inlet pipe is provided with an inlet pump; the outlet pipe is also connected to the outlet pool, the inlet pool is used to store sewage, and the outlet pool is used to receive the sewage after purification.

9. The artificial wetland system for deep purification of low carbon-nitrogen ratio wastewater according to claim 8, characterized in that: The number of the wetland unit rows, the number of the water inlet pipes, the number of the water inlet pumps and the number of the water outlet pipes are all multiple, and the multiple wetland unit rows are arranged along a first direction, and the first direction is arranged at an angle to the arrangement direction of the multiple artificial wetland devices in the wetland unit row, and the wetland unit rows, the water inlet pipes, the water inlet pumps and the water outlet pipes are arranged one by one.

10. The artificial wetland system for deep purification of low carbon-nitrogen ratio wastewater according to claim 9, characterized in that: The first direction is arranged at an acute angle to the arrangement direction of the plurality of artificial wetland devices in the wetland unit row, and in the first direction, the height difference between two adjacent wetland unit rows is between 5 cm and 20 cm.

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