Sewage wetland treatment device and method

Abstract

The present invention provides a sewage wetland treatment device and method, comprising: a vertical subsurface flow treatment area and a surface flow area; the vertical subsurface flow treatment area comprises a vertical baffled water distribution unit; the vertical baffled water distribution unit comprises at least two vertical water distribution devices; the vertical water distribution device comprises a lower anaerobic reaction area and an upper aerobic reaction area; a ceramsite layer loaded with Co / Ni active components is arranged in the lower anaerobic reaction area, an aerobic matrix layer and a plant planting layer arranged above the aerobic matrix layer are arranged in the upper aerobic reaction area; thick carbon grass is planted in the plant planting layer; the surface flow area comprises a lower sewage reprocessing area and an upper viewing area; the upper viewing area is connected to the unit water outlet; and a qualified water outlet is arranged in the upper viewing area. The present invention can solve the problems of poor denitrification effect in the vertical subsurface flow artificial wetland in the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and more specifically, to a sewage wetland treatment device and method. Background Art

[0002] Improving the rate of rural domestic sewage treatment is an important goal of environmental protection. The country has gradually strengthened its efforts and investment in rural domestic sewage treatment. Rural domestic sewage treatment is urgent. Small water volume, scattered discharge, and complex water quality are the main characteristics of rural domestic sewage discharge in my country. In addition, rural areas lack operational capacity, limited sustainable operation and maintenance investment, low operating costs, simple operation and maintenance, stable effluent, and good environmental coordination. Sewage treatment technology, wetland treatment technology is an ideal process for rural sewage treatment.

[0003] As an environmentally friendly sewage treatment technology with low investment, low energy consumption and low operating cost, artificial wetlands are widely used in rural sewage treatment. However, due to the lack of funds and poor operation supervision, rural domestic sewage is directly discharged without effective purification, especially ammonia nitrogen (NH4 + -N) and total nitrogen (TN), resulting in excessive discharge of effluent NH4 + -N and TN do not meet the standards. Therefore, it is urgent to enhance the denitrification system of the rural sewage wetland treatment process to reduce the NH4 + -N, TN can stably meet the requirements of Class B standard (GB 18918-2002) (NH4 + -N≤5mg / L, TN≤15mg / L).

[0004] At present, artificial wetland technology is applied to rural sewage treatment. Wetlands mainly use gravel and crushed stone as fillers, which have poor pollutant removal effects, especially limited removal of ammonia nitrogen. Since the formation of biofilm takes time, the initial operation effect of wetlands is limited. Therefore, as an important component of artificial wetlands, the selection and improvement of fillers play an important role in improving the pollutant removal effect of wetlands.

[0005] Vertical subsurface flow artificial wetlands have the advantages of small footprint, high oxygen transfer efficiency, and significant nitrification. However, under the influence of wetland plant metabolism, the nitrification and denitrification of artificial wetlands will produce interlayer differences, resulting in poor denitrification effects in vertical subsurface flow artificial wetlands. This is a difficult problem for artificial wetlands to treat low-carbon source wastewater. Summary of the invention

[0006] In view of the above problems, the purpose of the present invention is to provide a sewage wetland treatment device and method to solve the problems in the current prior art that due to the metabolism of wetland plants, the nitrification and denitrification of artificial wetlands produce interlayer differences, resulting in poor denitrification effect in vertical subsurface flow artificial wetlands.

[0007] The present invention provides a sewage wetland treatment device, comprising: a vertical subsurface flow treatment area and a surface flow area; wherein the vertical subsurface flow treatment area comprises a vertical baffled water distribution unit; the vertical baffled water distribution unit comprises at least two vertical water distribution devices; the vertical water distribution device comprises a lower anaerobic reaction area and an upper aerobic reaction area; a ceramsite layer loaded with Co / Ni active components is arranged in the lower anaerobic reaction area, an aerobic matrix layer and a plant planting layer arranged above the aerobic matrix layer are arranged in the upper aerobic reaction area; for two adjacent vertical water distribution devices, the former vertical water distribution device The water inlet and outlet of the device are respectively arranged in the lower anaerobic reaction area and the upper aerobic reaction area, the water inlet and outlet of the rear vertical water distribution device are respectively arranged in the upper aerobic reaction area and the lower anaerobic reaction area, and the water outlet of the front vertical water distribution device is connected with the water inlet of the rear vertical water distribution device; in the vertical baffle water distribution unit, the water inlet and outlet of the vertical water distribution devices located on both sides serve as the unit sewage inlet and unit water outlet of the vertical baffle water distribution unit respectively; the surface flow area includes a lower sewage reprocessing area and an upper viewing area.

[0008] In addition, a preferred solution is that the vertical baffle water distribution unit includes an odd number of the vertical water distribution devices.

[0009] In addition, a preferred solution is that, for the adjacent vertical water distribution devices, the water outlet of the previous vertical water distribution device and the water inlet of the subsequent vertical water distribution device are connected by a water distribution pipe; a sewage inlet pipe is arranged at the water inlet of the first vertical water distribution device in the vertical baffle water distribution unit; a water outlet pipe is arranged at the water outlet of the last vertical water distribution device in the vertical baffle water distribution unit, and the water outlet end of the water outlet pipe is arranged in the upper viewing area.

[0010] In addition, a preferred solution is that a graded gravel layer is arranged at the bottom inside the lower anaerobic reaction area; the expanded clay layer is arranged on the upper part of the graded gravel layer; for two adjacent vertical water distribution devices, the water inlet of the former vertical water distribution device and the water outlet of the latter vertical water distribution device are both arranged in the graded gravel layer of the lower anaerobic reaction area.

[0011] In addition, a preferred solution is that the aerobic matrix layer includes a zeolite layer, a volcanic rock layer and a gravel layer from bottom to top; the plant planting layer is arranged on the upper part of the gravel layer; for two adjacent vertical water distribution devices, the water outlet of the former vertical water distribution device and the water inlet of the latter vertical water distribution device are both arranged in the gravel layer of the upper aerobic reaction area.

[0012] In addition, a preferred solution is that a layered partition is horizontally arranged in the vertical water distribution device; the layered partition separates the vertical water distribution device into the upper aerobic reaction area and the lower anaerobic reaction area.

[0013] In addition, a preferred solution is that the space ratio of the upper aerobic reaction area to the lower anaerobic reaction area is 2:1; and the residence reaction time of the sewage in the lower anaerobic reaction area is greater than 2 hours.

[0014] In addition, a preferred solution is that the packing density of the ceramsite layer does not exceed 90% of the spatial volume of the lower anaerobic reaction zone.

[0015] In addition, a preferred solution is that the lower sewage retreatment area includes, from top to bottom, a second expanded clay layer loaded with Co / Ni active components and a second graded gravel layer; and the spatial height of the lower sewage retreatment area is smaller than that of the lower anaerobic reaction area.

[0016] In addition, a preferred solution is that an ornamental plant layer is provided in the upper ornamental area; and the upper ornamental area and the lower sewage reprocessing area are separated by a partition.

[0017] The present invention provides a sewage wetland treatment method, which uses the sewage wetland treatment device as described above to treat the sewage to be treated; the method comprises the following steps:

[0018] Introducing the sewage to be treated into the vertical submerged flow treatment area, and allowing the sewage to be treated to enter the first vertical water distribution device through the unit sewage inlet;

[0019] In the lower anaerobic reaction area of ​​the first vertical water distribution device, the sewage to be treated undergoes a full denitrification reaction under the action of the denitrifying bacteria in the lower anaerobic reaction area and the Co / Ni active components loaded in the ceramsite layer to obtain sewage with ammonia nitrogen removed;

[0020] As the water level of the sewage in the lower anaerobic reaction area of ​​the first vertical water distribution device increases, the sewage from which ammonia nitrogen has been removed enters the upper aerobic reaction area of ​​the first vertical water distribution device;

[0021] In the aerobic reaction area at the top of the first vertical water distribution device, the sewage from which ammonia nitrogen has been removed undergoes an aerobic microbial decomposition reaction under the condition that oxygen is provided by the plant planting layer, thereby obtaining sewage after microbial decomposition;

[0022] The sewage decomposed by the microorganisms enters the next vertical water distribution device from the first vertical water distribution device, and the baffled water distribution treatment is repeated until the sewage treatment is completed. The sewage after the treatment enters the surface flow area through the unit water outlet.

[0023] As can be seen from the above technical scheme, the sewage wetland treatment device and method provided by the present invention optimizes the treatment environment in the wetland by setting the vertical subsurface flow treatment area into a continuous baffled water distribution and water collection structure, effectively solving the problem of poor denitrification in the subsurface flow wetland; by setting a ceramsite layer loaded with Co / Ni active components in the lower anaerobic reaction area, using the unsaturated metal ion coordination of Co / Ni, the positive hydrogen ions and negative hydroxides generated by hydrolysis are adsorbed on the surface of the ceramsite to form oxygen active groups, effectively strengthening the chemical oxidation removal process of ammonia nitrogen, and fully converting it into denitrification substrates such as nitrate nitrogen and nitrite nitrogen. , enhance the wetland's treatment efficiency of nitrogen in sewage; the setting of the surface flow area further guarantees the effluent water quality of the vertical subsurface flow treatment area, and further improves the surrounding environment, which is in line with the goal of comprehensive rural environmental improvement; the treated effluent ammonia nitrogen can be reduced from ≤30mg / L to 5mg / L, and the total nitrogen can be reduced from ≤50mg / L to 15mg / L; the present invention has high denitrification efficiency, stable operation, and the effluent ammonia nitrogen index after treatment can stably meet the requirements of Class A standard (GB18918-2002) (NH4+-N≤5mg / L, TN≤15mg / L).

[0024] In order to achieve the above and related purposes, one or more aspects of the present invention include the features that will be described in detail later. The following description and the accompanying drawings describe some exemplary aspects of the present invention in detail. However, these aspects indicate only some of the various ways in which the principles of the present invention can be used. In addition, the present invention is intended to include all these aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] By referring to the following description in conjunction with the accompanying drawings, and with a more comprehensive understanding of the present invention, other objects and results of the present invention will become more apparent and easy to understand. In the accompanying drawings:

[0026] Figure 1 is a schematic structural diagram of a sewage wetland treatment device according to an embodiment of the present invention;

[0027] Figure 2 Flow chart of a sewage wetland treatment method according to an embodiment of the present invention.

[0028] In the attached drawings, 1-vertical subsurface flow treatment area, 11-vertical water distribution device, 12-lower anaerobic reaction area, 121-ceramsite layer, 13-upper aerobic reaction area, 131-thick carbon grass, 132-zeolite layer, 133-volcanic rock layer, 134-gravel layer, 14-unit sewage inlet, 15-unit water outlet, 16-layered partition, 2-surface flow area, 21-lower sewage retreatment area, 211-second ceramsite layer, 212-second graded gravel layer, 22-upper ornamental area, 221-ornamental plant layer, 23-standard water outlet, 24-partition, 3-water distribution pipe, 4-sewage inlet pipe, 5-outlet pipe.

[0029] The same reference numerals throughout the drawings indicate similar or corresponding features or functions. DETAILED DESCRIPTION

[0030] In the following description, for the purpose of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments. However, it is apparent that these embodiments may also be implemented without these specific details.

[0031] In view of the above-mentioned current prior art, due to the influence of wetland plant metabolism, the nitrification and denitrification of the artificial wetland produce interlayer differences, resulting in poor denitrification effect in the vertical subsurface flow artificial wetland, and other problems, a sewage wetland treatment device and method are proposed.

[0032] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0033] In order to illustrate the sewage wetland treatment device and method provided by the present invention, Figure 1 The structure of a sewage wetland treatment device according to an embodiment of the present invention is shown; Figure 2 The flowchart of the sewage wetland treatment method according to an embodiment of the present invention is shown.

[0034] like Figure 1 Combination Figure 2As shown together, the sewage wetland treatment device provided by the present invention includes: a vertical submerged flow treatment area 1 and a surface flow area 2; wherein the vertical submerged flow treatment area 1 includes a vertical baffled water distribution unit; the vertical baffled water distribution unit includes at least two vertical water distribution devices 11; the vertical water distribution device 11 includes a lower anaerobic reaction area 12 and an upper aerobic reaction area 13; a ceramsite layer 121 loaded with Co / Ni active components is arranged in the lower anaerobic reaction area 12, and an aerobic matrix layer and a plant planting layer 131 arranged above the aerobic matrix layer are arranged in the upper aerobic reaction area 13; for two adjacent vertical water distribution devices 11, the water inlet of the previous vertical water distribution device 11 The inlet and outlet are respectively arranged in the lower anaerobic reaction area 12 and the upper aerobic reaction area 13, the water inlet and outlet of the rear vertical water distribution device 11 are respectively arranged in the upper aerobic reaction area 13 and the lower anaerobic reaction area 12, and the water outlet of the front vertical water distribution device 11 is connected with the water inlet of the rear vertical water distribution device 11; in the vertical baffle water distribution unit, the water inlet and outlet of the vertical water distribution devices located on both sides serve as the unit sewage inlet 14 and the unit water outlet 15 of the vertical baffle water distribution unit respectively; the surface flow area 2 includes a lower sewage reprocessing area 21 and an upper viewing area 22; the upper viewing area 22 is connected to the unit water outlet 15.

[0035] Among them, a qualified water outlet 23 is provided in the upper viewing area 22.

[0036] Thick carbon grass is planted in the plant planting layer 131; thick carbon grass is a suitable plant for planting, which grows well in moist, well-drained, sandy, medium to high fertility weakly acidic soil, and has low cost, does not damage the soil fertility, and is easy to reproduce.

[0037] The vertical submerged flow treatment area 1 and the surface flow area 2 can be divided into two upper and lower areas by setting layered partitions. The vertical submerged flow treatment area 1 is divided into a lower anaerobic reaction area 12 and an upper aerobic reaction area 13, and the surface flow area 2 is divided into a lower sewage reprocessing area 21 and an upper viewing area 22.

[0038] In the surface flow area 2, the water treated in the vertical submerged flow treatment area 1 is further treated through the lower sewage reprocessing area 21 to further ensure the water quality.

[0039] By setting the vertical subsurface flow treatment area 1 into a structure of continuous baffled water distribution and water collection, the treatment environment in the wetland is optimized, and the problem of poor denitrification in the subsurface flow wetland is effectively solved; by setting a ceramsite layer 121 loaded with Co / Ni active components in the lower anaerobic reaction area 12, the unsaturated metal ion coordination of Co / Ni is utilized, and the positive hydrogen ions and negative hydroxides generated by hydrolysis are adsorbed on the surface of the ceramsite to form oxygen active groups, which effectively strengthens the chemical oxidation removal process of ammonia nitrogen, fully converts it into denitrification substrates such as nitrate nitrogen and nitrite nitrogen, and enhances the wetland's treatment efficiency of nitrogen in sewage; the setting of the surface flow area 2 further guarantees the effluent water quality of the vertical subsurface flow treatment area 1, and at the same time further improves the surrounding environment, which is in line with the goal of comprehensive rural environmental improvement; the ammonia nitrogen in the treated effluent can be reduced from ≤30 mg / L to 5 mg / L, and the total nitrogen can be reduced from ≤50 mg / L to 15 mg / L; the present invention has high denitrification efficiency, stable operation, and the ammonia nitrogen index of the treated effluent can stably reach the first-class A standard (GB 18918—2002) requirements (NH4+-N≤5mg / L, TN≤15mg / L).

[0040] As a preferred embodiment of the present invention, the vertical baffle water distribution unit includes an odd number of vertical water distribution devices 11. Figure 1 As shown, the unit sewage inlet 14 is arranged in the lower anaerobic reaction area 12 of the first vertical water distribution device 11, and the unit water outlet 15 is arranged in the upper aerobic reaction area 13 of the last vertical water distribution device 11. Through the bottom water inlet method, the sewage first passes through the lower anaerobic reaction area 12 of the first vertical water distribution device 11, and after the baffle treatment, it enters the surface flow area 2.

[0041] As a preferred embodiment of the present invention, for adjacent vertical water distribution devices 11, the outlet of the previous vertical water distribution device 11 is connected to the inlet of the next vertical water distribution device 11 through a water distribution pipe 3; a sewage inlet pipe 4 is provided at the water inlet of the first vertical water distribution device 11 in the vertical baffle water distribution unit; an outlet pipe 5 is provided at the outlet of the last vertical water distribution device 11 in the vertical baffle water distribution unit, and the outlet end of the outlet pipe 5 is provided in the upper viewing area 22. The sewage to be treated enters the first vertical water distribution device 11 in the vertical baffle water distribution unit through the sewage inlet pipe 4, and then after being baffled in sequence, the treated sewage enters the surface flow area 2 from the outlet pipe 5 of the last vertical water distribution device 11 of the vertical baffle water distribution unit.

[0042] As a preferred embodiment of the present invention, a graded gravel layer 122 is arranged at the bottom of the lower anaerobic reaction area 12; the expanded clay layer 121 is arranged on the upper part of the graded gravel layer 122; for two adjacent vertical water distribution devices 11, the water inlet of the previous vertical water distribution device 11 and the water outlet of the latter vertical water distribution device are both arranged in the graded gravel layer 122 of the lower anaerobic reaction area 12.

[0043] The lower anaerobic reaction area 12 forms an anaerobic / anoxic environment because oxygen cannot be transmitted through plants. The denitrifying bacteria therein use the combined nitrogen to carry out denitrification reaction with the organic carbon in the sewage to be treated, so that the combined nitrogen becomes molecular nitrogen, achieving the effect of denitrification, carbon removal and hydrogen removal at the same time. The ceramsite layer 121 is a porous ceramsite loaded with Co / Ni active components. The unsaturated metal ion coordination of Co / Ni is used, and the positive hydrogen ions and negative hydroxides produced by hydrolysis are adsorbed on the surface of the ceramsite to form oxygen active groups, which effectively strengthens the chemical oxidation removal process of ammonia nitrogen and fully converts it into denitrification substrates such as nitrate nitrogen and nitrite nitrogen. At the same time, the ceramsite voids can fix a large number of facultative denitrifying bacteria to carry out denitrification reaction and strengthen the denitrification effect.

[0044] As a preferred embodiment of the present invention, the aerobic matrix layer includes a zeolite layer 132, a volcanic rock layer 133 and a gravel layer 134 from bottom to top; the plant planting layer 131 is arranged on the upper part of the gravel layer 134; for two adjacent vertical water distribution devices 11, the water outlet of the previous vertical water distribution device 11 and the water inlet of the next vertical water distribution device 11 are both arranged in the gravel layer 134 of the upper aerobic reaction area 13. Zeolite, volcanic rock and gravel are matrix fillers of artificial wetlands, which mainly provide growth media for plants and microorganisms, and can directly remove pollutants through precipitation, filtration and adsorption. Through the interception, fixation, transmission and release of plant roots, an aerobic environment is formed in the upper aerobic reaction area 13, regulating the nitrogen conversion pathway and nitrification process; aerobic microorganisms oxidize and decompose BOD5 in sewage, and organic nitrogen and ammonia nitrogen in sewage are converted into nitrified nitrogen through nitrification reaction and flow to the next anoxic section.

[0045] As a preferred embodiment of the present invention, a layered baffle 16 is horizontally arranged in the vertical water distribution device 11 ; the layered baffle 16 separates the vertical water distribution device 11 into an upper aerobic reaction area 13 and a lower anaerobic reaction area 12 .

[0046] As a preferred embodiment of the present invention, the space ratio of the upper aerobic reaction area 13 to the lower anaerobic reaction area 12 is 2:1; and the residence reaction time of the sewage in the lower anaerobic reaction area 12 is greater than 2 hours.

[0047] As a preferred embodiment of the present invention, the packing density of the ceramsite layer 121 does not exceed 90% of the spatial volume of the lower anaerobic reaction area 12 .

[0048] The spatial ratio of the upper aerobic reaction area 13 to the lower anaerobic reaction area 12 is 2:1, and the residence time of sewage in the lower anaerobic reaction area 12 is not less than 2 hours. The lower anaerobic reaction area 12 is filled with optimized wetland filler - porous ceramsite loaded with Co / Ni active components above the graded gravel layer 122 of the bottom layer to form a ceramsite layer 121, and the filling density does not exceed 90% of the volume of the lower anaerobic reaction area 12.

[0049] As a preferred embodiment of the present invention, the lower sewage reprocessing area 21 includes, from top to bottom, a second ceramsite layer 211 loaded with Co / Ni active components and a second graded gravel layer 212; and the spatial height of the lower sewage reprocessing area 21 is smaller than the lower anaerobic reaction area 12. The water entering the surface flow area 2 is further processed in the lower sewage reprocessing area 21, which further guarantees the quality of the discharged water.

[0050] As a preferred embodiment of the present invention, an ornamental plant layer 221 is provided in the upper ornamental area 22; the upper ornamental area 22 is separated from the lower sewage reprocessing area 21 by a partition 24. The main function of the surface flow artificial wetland in the surface flow area 2 is to stabilize the effluent water quality and show the purification effect. Aquatic plants are planted in the surface flow wetland to construct a complete water ecosystem and create a beautiful water landscape, which plays a significant role in the comprehensive improvement of the rural environment.

[0051] The sewage wetland treatment method provided by the present invention uses the sewage wetland treatment device as described above to treat the sewage to be treated; and comprises the following steps:

[0052] S1, introducing the sewage to be treated into the vertical submerged flow treatment area 1, and allowing the sewage to be treated to enter the first vertical water distribution device 11 through the unit sewage inlet 14;

[0053] S2, in the lower anaerobic reaction area 12 of the first vertical water distribution device 11, the sewage to be treated is fully denitrified by the denitrifying bacteria in the lower anaerobic reaction area 12 and the Co / Ni active components loaded in the ceramsite layer 121, to obtain sewage with ammonia nitrogen removed;

[0054] S3, as the water level of the sewage in the lower anaerobic reaction area 12 of the first vertical water distribution device 11 increases, the sewage from which ammonia nitrogen has been removed enters the upper aerobic reaction area 13 of the first vertical water distribution device 11;

[0055] S4, in the upper aerobic reaction area 13 of the first vertical water distribution device 11, the sewage from which ammonia nitrogen has been removed undergoes aerobic microbial decomposition reaction under the condition that oxygen is provided by the plant planting layer 131, thereby obtaining sewage after microbial decomposition;

[0056] S4. The sewage after microbial decomposition enters the next vertical water distribution device 11 from the first vertical water distribution device 11, and the baffled water distribution treatment is repeated until the sewage treatment is completed. The sewage after the treatment enters the surface flow area 2 through the unit water outlet 15 and is discharged through the qualified water outlet 23.

[0057] The removal of ammonia nitrogen in the sewage to be treated requires sufficient nitrification before the denitrification stage. Through the continuous up and down baffled water distribution of the vertical baffled water distribution unit, the system forms a multi-level A / O environment. At the same time, the porous ceramsite loaded with Co / Ni active components in the lower anaerobic / anoxic zone is used to enhance the denitrification efficiency of the denitrification system, thereby achieving the enhanced denitrification treatment effect. The main function of the artificial wetland provided by the surface flow area 2 at the end of the process is to stabilize the effluent water quality and show the purification effect. Aquatic plants are planted in the surface flow wetland to build a complete water ecosystem and create a beautiful water landscape, which plays a significant role in the comprehensive improvement of the rural environment. Through the generation of a complete biological chain and the repeated multi-stage anaerobic-aerobic-anaerobic biological treatment system, various pollutants in the sewage are fully degraded, ammonia nitrogen has a good removal effect, and the effluent water quality is stable.

[0058] In order to better describe the sewage wetland treatment device and method provided by the present invention, the following specific implementation methods are provided.

[0059] Example 1

[0060] The pH value of rural domestic sewage to be treated is 6-9, COD cr ≤350mg / L, BOD5≤150mg / L, ammonia nitrogen≤30mg / L, total nitrogen≤50mg / L, total phosphorus≤3mg / L.

[0061] The sewage wetland treatment device provided by the present invention is used for treatment. The raw water enters the device after the water quality and quantity are adjusted in the pretreatment regulating tank. The sewage first passes through the vertical submerged flow treatment area 1 in the device through the way of water inlet from below. In the vertical submerged flow treatment area 1, it first enters the lower anaerobic reaction area 12 of the first vertical water distribution device 11 of the vertical baffled water distribution unit. The HRT of the sewage in this area is 1 to 4 hours. The denitrifying bacteria in the area use the organic carbon in the sewage to carry out denitrification reaction, thereby reducing COD and BOD5 in the sewage. The microbial cell synthesis of denitrifying bacteria and the short-range nitrification-anaerobic ammonia oxidation reaction are used to convert the combined nitrogen into molecular nitrogen, thereby reducing the ammonia nitrogen in the sewage. At the same time, the porous ceramsite filler loaded with Co / Ni active components in this area has a filling height of 30 cm, which can fix a large number of facultative denitrifying bacteria to carry out denitrification reaction, which has the effect of strengthening the removal of ammonia nitrogen.

[0062] After the sewage passes through the lower anaerobic reaction area 12, it rises to the upper aerobic reaction area in the first vertical water distribution device 11 as the water level rises. Through the conduction and transportation of oxygen by the plant roots, the area is in an aerobic environment. The HRT of this area is 6 to 10 hours. The aerobic microorganisms in this layer oxidize and decompose the BOD5 in the sewage. The organic nitrogen and ammonia nitrogen in the sewage are converted into nitrified nitrogen through nitrification reaction and flow to the next anoxic section. The denitrifying bacteria in it use the combined nitrogen and the organic carbon in the sewage to carry out denitrification reaction, turning the combined nitrogen into molecular nitrogen, achieving the effect of simultaneous denitrification, carbon removal and hydrogen removal.

[0063] In the sewage wetland treatment device provided by the present invention, sewage is introduced / distributed by means of up and down bends, so that a complete biological chain is generated in the device. Through the repeated anaerobic-aerobic-anaerobic biological treatment system, various pollutants in the sewage are fully degraded, and ammonia nitrogen is well removed. The effluent adopts the surface flow wetland to construct the water ecological landscape. Under the condition of stabilizing the effluent water quality, the landscape system of the village is constructed, which plays a significant role in the comprehensive improvement of the rural environment.

[0064] The ammonia nitrogen index of the effluent after the raw water is treated by the wetland treatment device of the present invention can stably meet the requirements of the Class A standard (GB 18918-2002) (NH4 + -N≤5mg / L, TN≤15mg / L).

[0065] It can be seen from the above specific embodiments that the sewage wetland treatment device and method provided by the present invention optimizes the treatment environment in the wetland by setting the vertical submerged flow treatment area into a continuous baffled water distribution and water collection structure, and effectively solves the problem of poor denitrification in the submerged flow wetland; by setting a ceramsite layer loaded with Co / Ni active components in the lower anaerobic reaction area, the positive hydrogen ions and negative hydroxides generated by hydrolysis are adsorbed on the surface of the ceramsite to form oxygen active groups by utilizing the unsaturated metal ion coordination of Co / Ni, thereby effectively enhancing the chemical oxidation removal of ammonia nitrogen. The process fully converts the nitrogen into denitrification substrates such as nitrate nitrogen and nitrite nitrogen, thereby enhancing the wetland's treatment efficiency for nitrogen in sewage. The setting of the surface flow area further guarantees the effluent water quality of the vertical subsurface flow treatment area, and further improves the surrounding environment, which is in line with the goal of comprehensive rural environmental improvement. The treated effluent ammonia nitrogen can be reduced from ≤30 mg / L to 5 mg / L, and the total nitrogen can be reduced from ≤50 mg / L to 15 mg / L. The present invention has high denitrification efficiency, stable operation, and the effluent ammonia nitrogen index after treatment can stably meet the requirements of Class A standard (GB 18918-2002) (NH4+-N≤5 mg / L, TN≤15 mg / L).

[0066] As described above, the sewage wetland treatment device and method proposed in the present invention are described by way of example with reference to the accompanying drawings. However, those skilled in the art should understand that various improvements can be made to the sewage wetland treatment device and method proposed in the present invention without departing from the content of the present invention. Therefore, the protection scope of the present invention should be determined by the content of the attached claims.

Claims

1. A sewage wetland treatment device, characterized in that: include: Vertical subsurface flow treatment area and surface flow area; among them, The vertical submerged flow treatment area includes a vertical baffled water distribution unit; the vertical baffled water distribution unit includes at least two vertical water distribution devices; A layered baffle is horizontally arranged in the vertical water distribution device; the layered baffle separates the vertical water distribution device into an upper aerobic reaction area and a lower anaerobic reaction area; A ceramsite layer loaded with Co / Ni active components is arranged in the lower anaerobic reaction area, and an aerobic matrix layer and a plant planting layer arranged above the aerobic matrix layer are arranged in the upper aerobic reaction area; For two adjacent vertical water distribution devices, the water inlet and the water outlet of the first vertical water distribution device are respectively arranged in the lower anaerobic reaction area and the upper aerobic reaction area, and the water inlet and the water outlet of the second vertical water distribution device are respectively arranged in the upper aerobic reaction area and the lower anaerobic reaction area, and the water outlet of the first vertical water distribution device is connected to the water inlet of the second vertical water distribution device; in the vertical baffle water distribution unit, the water inlet and the water outlet of the vertical water distribution devices on both sides serve as the unit sewage inlet and the unit water outlet of the vertical baffle water distribution unit respectively; The surface flow area includes a lower sewage reprocessing area and an upper viewing area; the upper viewing area is connected to the unit water outlet.

2. The sewage wetland treatment device according to claim 1, characterized in that: The vertical baffle water distribution unit includes an odd number of vertical water distribution devices.

3. The sewage wetland treatment device according to claim 1, characterized in that: For the adjacent vertical water distribution devices, the water outlet of the previous vertical water distribution device and the water inlet of the next vertical water distribution device are connected via a water distribution pipe; A sewage inlet pipe is arranged at the water inlet of the first vertical water distribution device of the vertical baffle water distribution unit; an outlet pipe is arranged at the water outlet of the last vertical water distribution device of the vertical baffle water distribution unit, and the outlet end of the outlet pipe is arranged in the upper viewing area.

4. The sewage wetland treatment device according to claim 1, characterized in that: A graded gravel layer is provided at the bottom of the lower anaerobic reaction area; The ceramsite layer is arranged on the upper part of the graded crushed stone layer; For two adjacent vertical water distribution devices, the water inlet of the first vertical water distribution device and the water outlet of the second vertical water distribution device are both arranged in the graded gravel layer of the lower anaerobic reaction area.

5. The sewage wetland treatment device according to claim 1, characterized in that: The good oxygen matrix layer includes a zeolite layer, a volcanic rock layer and a gravel layer from bottom to top; The plant planting layer is arranged on the upper part of the gravel layer; For two adjacent vertical water distribution devices, the water outlet of the first vertical water distribution device and the water inlet of the second vertical water distribution device are both arranged in the gravel layer of the upper aerobic reaction area.

6. The sewage wetland treatment device according to claim 1, characterized in that: The space ratio of the upper aerobic reaction area to the lower anaerobic reaction area is 2:1; The sewage stays in the lower anaerobic reaction area for more than 2 hours.

7. The sewage wetland treatment device according to claim 1, characterized in that: The packing density of the ceramsite layer does not exceed 90% of the spatial volume of the lower anaerobic reaction zone.

8. The sewage wetland treatment device according to claim 1, characterized in that: The lower sewage reprocessing area includes, from top to bottom, a second ceramsite layer loaded with Co / Ni active components and a second graded crushed stone layer; and the spatial height of the lower sewage reprocessing area is smaller than that of the lower anaerobic reaction area.

9. The sewage wetland treatment device according to claim 1, characterized in that: An ornamental plant layer is provided in the upper ornamental area; The upper viewing area and the lower sewage reprocessing area are separated by a partition.

10. A sewage wetland treatment method, characterized in that: The method of treating the sewage to be treated by using the sewage wetland treatment device according to any one of claims 1 to 9 comprises the following steps: Introducing the sewage to be treated into the vertical submerged flow treatment area, and allowing the sewage to be treated to enter the first vertical water distribution device through the unit sewage inlet; In the lower anaerobic reaction area of ​​the first vertical water distribution device, the sewage to be treated undergoes a full denitrification reaction under the action of the denitrifying bacteria in the lower anaerobic reaction area and the Co / Ni active components loaded in the ceramsite layer to obtain sewage with ammonia nitrogen removed; As the water level of the sewage in the lower anaerobic reaction area of ​​the first vertical water distribution device increases, the sewage from which ammonia nitrogen has been removed enters the upper aerobic reaction area of ​​the first vertical water distribution device; In the aerobic reaction area at the top of the first vertical water distribution device, the sewage from which ammonia nitrogen has been removed undergoes an aerobic microbial decomposition reaction under the condition that oxygen is provided by the plant planting layer, thereby obtaining sewage after microbial decomposition; The sewage decomposed by the microorganisms enters the next vertical water distribution device from the first vertical water distribution device, and the baffled water distribution treatment is repeated until the sewage treatment is completed. The sewage after the treatment enters the surface flow area through the unit water outlet.

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