Sulfur autotrophic denitrification constructed wetland

Abstract

The utility model discloses a sulfur autotrophic denitrification constructed wetland, which belongs to the field of constructed wetlands, and comprises a constructed wetland body, a powdered sulfur vertical pipe, a sewage inlet pipe, a modularized alkaline filter material layer and a powdered sulfur layer, the powdered sulfur layer is laid at the bottom of the constructed wetland body, the modularized alkaline filter material layer is placed at the top of the powdered sulfur layer, and the sewage inlet pipe is connected with the modularized alkaline filter material layer. The sewage inlet pipe extends into the powdered sulfur layer or below the powdered sulfur layer, and the powdered sulfur vertical pipe is fixedly communicated with the sewage inlet pipe. According to the sulfur autotrophic denitrification constructed wetland disclosed by the utility model, sulfur autotrophic denitrification bacteria are gradually enriched to the modularized alkaline filter material layer while total nitrogen removal is realized, and a sulfur autotrophic denitrification bacteria-carrying filter material is continuously generated, so that sewage recycling and resource utilization are realized.

Description

Technical Field

[0001] The utility model belongs to the field of constructed wetlands, and particularly relates to a sulfur autotrophic denitrification constructed wetland. Background Art

[0002] In China, most of the urban sewage has a low ratio of organic carbon to nitrogen. The traditional nitrification process will also consume some carbon sources, making the carbon source in the denitrification stage more insufficient, and it is difficult to achieve the theoretical analysis level of nitrogen removal from urban sewage. Therefore, it is usually necessary to additionally supplement organic carbon sources (such as methanol, sodium acetate, glucose) to meet the demand of heterotrophic denitrification for electron donors, so as to achieve the removal of total nitrogen. However, adding external organic carbon sources not only increases the operating cost, but also easily causes secondary pollution.

[0003] Sulfur autotrophic denitrification refers to the process in which sulfur autotrophic denitrifying bacteria use reduced sulfur as an electron donor to reduce nitrate nitrogen to nitrogen gas under anoxic conditions. This process does not require external organic carbon sources and has a high denitrification efficiency, which is expected to open up a new way for the removal of total nitrogen from urban sewage. However, there are still some problems in the engineering application of sulfur autotrophic denitrification at present, which need to be further solved. (1) The optimal pH range of sulfur autotrophic denitrifying bacteria is 6.8 - 8.2, and the sulfur autotrophic denitrification reaction is a process that consumes alkalinity. As the reaction progresses, the system pH will gradually decrease. If alkalinity is not supplemented additionally, the sulfur autotrophic denitrification activity will be inhibited or even completely lost. (2) The growth rate of sulfur autotrophic denitrifying bacteria is low, the generation time is long, and the preservation of the bacterial strain is also a major problem, thus restricting its application in engineering. Therefore, there is an urgent need for a sulfur autotrophic denitrification constructed wetland that can not only remove the total nitrogen in the effluent but also cultivate the sulfur autotrophic denitrification carrier filter material. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a sulfur autotrophic denitrification constructed wetland to overcome at least one of the above defects in the prior art.

[0005] To achieve this purpose, the utility model adopts the following technical solutions:

[0006] The sulfur autotrophic denitrification constructed wetland provided by the utility model includes a constructed wetland body, a sulfur powder riser pipe, a sewage inlet pipe, a modular alkaline filter layer, and a sulfur powder layer. The sulfur powder layer is laid at the bottom of the constructed wetland body, the modular alkaline filter layer is placed on the top of the sulfur powder layer, the sewage inlet pipe extends into the sulfur powder layer or below the sulfur powder layer, and the sulfur powder riser pipe is fixedly communicated with the sewage inlet pipe.

[0007] Preferably, a cement blanket is arranged on the inner side wall of the constructed wetland body.

[0008] Preferably, the modular alkaline filter layer includes a number of modular alkaline filters, and the thickness of the modular alkaline filter layer is 80 - 120 cm.

[0009] Preferably, the modular alkaline filter material comprises a soft woven bag, and a calcium-based denitrification and dephosphorization filter material filled in the soft woven bag.

[0010] Preferably, the particle size of the calcium-based denitrification and phosphorus removal filter material is 5-10 mm.

[0011] Preferably, the sewage inlet pipe includes a first inlet section, a second inlet section, and a third inlet section. The second inlet section connects the first inlet section and the third inlet section. The first inlet section is located above the artificial wetland body, the second inlet section is tilted downward, and the third inlet section is horizontally arranged in the sulfur powder layer.

[0012] Preferably, the sulfur powder riser is fixedly connected to the top of the first water inlet section, and the feed port of the sulfur powder riser is located above the first water inlet section.

[0013] Preferably, it also includes a water distribution layer, which is arranged below the sulfur powder layer, and the sewage inlet pipe extends to the inside of the water distribution layer.

[0014] Preferably, the water distribution layer has a thickness of 20-30 cm and is paved with a plurality of calcium-based denitrification and dephosphorization filter materials or crushed stones with a particle size of 20-40 mm.

[0015] The beneficial effects of the utility model are:

[0016] 1. While achieving total nitrogen removal, sulfur autotrophic denitrifying bacteria are gradually enriched in the modular alkaline filter layer, continuously generating sulfur autotrophic denitrifying bacteria-carrying filter material, thus realizing the recycling and resource utilization of sewage.

[0017] 2. The use of soft woven bags not only avoids deviation and short-flow, but also facilitates lifting, transportation and replacement, making the sulfur autotrophic denitrification bacteria-laden filter material easy to take out and transport.

[0018] 3. The modular alkaline filter layer is adopted. The sulfur autotrophic denitrification bacteria-laden filter material does not need to be stored separately. It can be directly stored in the operating wetland and can be taken out when used.

[0019] 4. Spread the sulfur powder at the bottom of the modular alkaline filter material layer. Due to the use of an upward flow pattern, the small particle size of the calcium-based denitrification and phosphorus removal filter material, and the certain weight of the sulfur powder, the sulfur powder will not be carried out of the artificial wetland body.

[0020] 5. Calcium-based denitrification and phosphorus removal filter material is used, which is alkaline and can replenish alkalinity to maintain the pH balance of the system.

[0021] 6. By setting up the sulfur powder riser, sulfur powder is directly added, and the sulfur powder enters the sulfur powder layer along with the sewage to replenish the sulfur powder, integrating water intake and sulfur powder replenishment.

[0022] 7. The growth rate of sulfur autotrophic denitrifying bacteria is relatively low, and the generation time is relatively long. However, the sulfur autotrophic denitrifying carrier filter media produced can be applied to new wetlands to play an inoculation role, which can shorten the start-up time of new sulfur autotrophic denitrifying wetlands and improve the sewage treatment efficiency.

[0023] 8. By utilizing the grading relationship between large-sized filter media and small-sized filter media in the upper part, the resistance is large among small-sized particles and small among large-sized particles, enabling the influent water to flow evenly upward in the bottom water distribution layer and achieving uniform water distribution. Description of the Drawings

[0024] Figure 1 It is a schematic structural diagram of the first embodiment of the present utility model.

[0025] Figure 2 It is a schematic structural diagram of the modular alkaline filter media of the first embodiment of the present utility model.

[0026] Figure 3 It is a schematic structural diagram of the sewage inlet pipe and sulfur powder riser of the first embodiment of the present utility model.

[0027] Figure 4 It is a schematic structural diagram of the second embodiment of the present utility model.

[0028] The reference signs in the drawings are: 1-artificial wetland body, 2-sulfur powder riser, 3-sewage inlet pipe, 4-sulfur powder layer, 5-cement blanket, 6-modular alkaline filter media layer, 61-soft woven bag, 62-calcium-based denitrification and phosphorus removal filter media, 31-first influent section, 32-second influent section, 33-third influent section, 7-water distribution layer. Detailed Embodiments

[0029] The present utility model will be further described below in conjunction with the drawings and detailed embodiments.

[0030] Contents not detailedly described in this specification belong to the prior art well-known to those skilled in the art. In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model. In addition, the terms "first", "second", "third", etc. are only used for differential description and cannot be understood as indicating or implying relative importance.

[0031] Embodiment 1:

[0032] As Figures 1 to 3As shown in the figure, the sulfur autotrophic denitrification constructed wetland provided in this embodiment includes a constructed wetland body 1, a sulfur powder riser 2, a sewage inlet pipe 3, a modular alkaline filter layer 6, and a sulfur powder layer 4. The sulfur powder layer 4 is laid at the bottom of the constructed wetland body 1, the modular alkaline filter layer 6 is placed on the top of the sulfur powder layer 4, the sewage inlet pipe 3 extends into the sulfur powder layer 4, and the sulfur powder riser 2 is fixedly communicated with the sewage inlet pipe 3. Among them, the modular alkaline filter layer 6 includes a number of modular alkaline filters 6, and the thickness of the modular alkaline filter layer 6 is 100 cm. The modular alkaline filter 6 includes a soft woven bag 61 and a calcium-based denitrification and phosphorus removal filter material 62 filled inside the soft woven bag 61. The particle size of the calcium-based denitrification and phosphorus removal filter material 62 is 5-10 mm. The use of the soft woven bag 61 not only has the function of avoiding uneven flow and short-circuit flow, but also has the functions of convenient hoisting, transportation, and replacement. And the filter material in the soft woven bag 61 uses the calcium-based denitrification and phosphorus removal filter material 62 that is easy for microorganisms to attach and grow. The sewage flows from the sulfur powder layer 4 upward through the modular alkaline filter layer 6 to ensure an anaerobic environment. The sulfur powder is laid at the bottom of the modular alkaline filter layer 6. Due to the use of the upward flow regime, the relatively small particle size of the calcium-based denitrification and phosphorus removal filter material 62, and the certain self-weight of the sulfur powder, the sulfur powder will not be carried out of the constructed wetland body 1; when the sulfur powder is exhausted, the sulfur powder is replenished through the sulfur powder riser 2. As the sulfur autotrophic denitrification constructed wetland operates, sulfur autotrophic denitrifying bacteria are gradually enriched in the modular alkaline filter layer 6, specifically enriched on the calcium-based denitrification and phosphorus removal filter material 62, to carry out sulfur autotrophic denitrification and nitrogen removal, forming a sulfur autotrophic denitrification carrier bacteria filter material. The sulfur autotrophic denitrification reaction is a process that consumes alkalinity. As the reaction progresses, the pH of the wetland will gradually decrease. If the alkalinity is not adjusted externally, the sulfur autotrophic denitrification activity will be inhibited or even completely lost. The calcium-based denitrification and phosphorus removal filter material 62 used in the present invention has its own alkalinity, can supplement alkalinity, and maintain the pH balance of the system, thus solving this problem. Replacing the sulfur autotrophic denitrification carrier bacteria filter material cultivated maturely in the constructed wetland with the new calcium-based denitrification and phosphorus removal filter material 62, the sulfur autotrophic denitrification constructed wetland can continuously produce sulfur autotrophic denitrification carrier bacteria filter material. Due to the use of the soft woven bag 61, the sulfur autotrophic denitrification carrier bacteria filter material is easy to take out and transport. It is convenient to use the sulfur autotrophic denitrification carrier bacteria filter material in combination with other filter materials in new engineering projects to play an inoculation role, which can shorten the start-up time of the new sulfur autotrophic denitrification wetland and improve the sewage treatment efficiency.

[0033] Among them, a cement blanket 5 is provided on the inner side wall of the constructed wetland body 1 to prevent sewage from seeping down and polluting groundwater.

[0034] Among them, the sewage inlet pipe 3 includes a first inlet section 31, a second inlet section 32, and a third inlet section 33. The second inlet section 32 connects the first inlet section 31 and the third inlet section 33. The first inlet section 31 is located above the artificial wetland body 1. The second inlet section 32 is arranged obliquely downward, and the third inlet section 33 is horizontally arranged in the sulfur powder layer 4. The sulfur powder riser 2 is fixedly connected to the top of the first inlet section 31, and the feed inlet of the sulfur powder riser 2 is located above the first inlet section 31. Through the setting mode of the sulfur powder riser 2, sulfur powder is directly put in, and the sulfur powder enters the sulfur powder layer 4 together with the sewage, so as to supplement the sulfur powder, integrating water inlet and sulfur powder supplement.

[0035] While realizing the total nitrogen removal of the present utility model, sulfur autotrophic denitrifying bacteria are gradually enriched in the calcium-based denitrification and phosphorus removal filter media 62, continuously generating sulfur autotrophic denitrifying carrier filter media, realizing the recycling and resource utilization of sewage. The growth rate of sulfur autotrophic denitrifying bacteria is low and the generation time is long, while the generated sulfur autotrophic denitrifying carrier filter media can be applied to a new wetland to play an inoculation role, which can shorten the start-up time of the new wetland of sulfur autotrophic denitrification and improve the sewage treatment efficiency. By adopting the modular alkaline filter layer 6, the sulfur autotrophic denitrifying carrier filter media does not need to be stored separately and is directly stored in the operating wetland for immediate use.

[0036] Embodiment 2:

[0037] As Figure 4 shown, the difference between this embodiment and Embodiment 1 is that:

[0038] The sewage inlet pipe extends below the sulfur powder layer. Specifically: a water distribution layer 7 is further included. The water distribution layer 7 is arranged below the sulfur powder layer, and the sewage inlet pipe 3 extends into the water distribution layer 7. The thickness of the water distribution layer 7 is 20 cm and is laid by a number of calcium-based denitrification and phosphorus removal filter media or gravel with a particle size of 30 mm. By using the grading relationship between the large-particle-size filter media in the upper part and the small-particle-size filter media, the resistance is large between small particle sizes and small between coarse particle sizes, so that the influent flows uniformly upward at the bottom water distribution layer to realize uniform water distribution.

[0039] The above embodiments are only used to illustrate the technical solutions of the present utility model and are not intended to limit it; although the present utility model has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that; it is still possible to modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present utility model.

Claims

1. Sulfur autotrophic denitrification artificial wetland, characterized by: It includes artificial wetland body, sulfur powder riser, sewage inlet pipe, modular alkaline filter layer, and sulfur powder layer; A sulfur powder layer is laid at the bottom of the artificial wetland body, and a modular alkaline filter material layer is placed on the top of the sulfur powder layer; The sewage inlet pipe extends to the inside of the sulfur powder layer or below the sulfur powder layer, and the sulfur powder riser is fixedly connected to the sewage inlet pipe.

2. The sulfur autotrophic denitrification artificial wetland according to claim 1, characterized in that: The inner side wall of the artificial wetland body is provided with a cement blanket.

3. The sulfur autotrophic denitrification artificial wetland according to claim 1, characterized in that: The modular alkaline filter material layer comprises a plurality of modular alkaline filter materials, and the thickness of the modular alkaline filter material layer is 80-120 cm.

4. The sulfur autotrophic denitrification artificial wetland according to claim 3, characterized in that: The modular alkaline filter material comprises a soft woven bag and a calcium-based denitrification and dephosphorization filter material filled in the soft woven bag.

5. The sulfur autotrophic denitrification artificial wetland according to claim 4, characterized in that: The particle size of the calcium-based denitrification and dephosphorization filter material is 5-10 mm.

6. The sulfur autotrophic denitrification artificial wetland according to claim 1, characterized in that: The sewage inlet pipe comprises a first inlet section, a second inlet section, and a third inlet section; The second water inlet section is connected to the first water inlet section and the third water inlet section; The first water inlet section is located above the artificial wetland body; The second water inlet section is arranged to be inclined downward; The third water inlet section is horizontally arranged on the sulfur powder layer.

7. The sulfur autotrophic denitrification artificial wetland according to claim 6, characterized in that: The sulfur powder riser is fixedly connected to the top of the first water inlet section, and the feed inlet of the sulfur powder riser is located above the first water inlet section.

8. The sulfur autotrophic denitrification artificial wetland according to claim 1, characterized in that: It also includes aquifers; The water distribution layer is arranged below the sulfur powder layer; The sewage inlet pipe extends to the interior of the water distribution layer.

9. The sulfur autotrophic denitrification artificial wetland according to claim 8, characterized in that: The water distribution layer has a thickness of 20-30 cm and is paved with a plurality of calcium-based denitrification and dephosphorization filter materials or crushed stones with a particle size of 20-40 mm.

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