Internal circulation sulfur autotrophic denitrification nitrogen removal reactor

Abstract

The utility model discloses an internal circulation sulfur autotrophic denitrification nitrogen removal reactor, which relates to the technical field of biological sewage treatment and comprises a reactor tank body, and a water inlet pipe, a mud-water separator and a water outlet pipe are arranged in the reactor tank body from bottom to top; a dissipation area is formed between the outer wall of the mud-water separator and the inner wall of the reactor tank body; the mud-water separator comprises a baffle plate at the upper part and a vertical flow sedimentation tank at the lower part, the baffle plate is of a barrel structure arranged above the vertical flow sedimentation tank, and a baffle area is formed between the outer wall of the baffle plate and the inner wall of a vertical flow sedimentation pipe; the vertical flow sedimentation tank is of a funnel structure, a sedimentation area is formed in the vertical flow sedimentation tank, and the top of the vertical flow sedimentation tank is immersed below the liquid level; the sludge-water separator is arranged in the reactor, and sulfur powder and sludge are precipitated and recycled through the cooperation of the baffle plate and the vertical flow precipitation tank, so that the loss of filler is avoided, the utilization rate of the sulfur powder can be improved, and the filler cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of sewage biological treatment, and particularly relates to an internal circulation sulfur autotrophic denitrification reactor. Background Art

[0002] With the development of economy and environmental protection, the content of nitrogen element in sewage is getting higher and higher. If not treated carefully, it is extremely easy to cause water eutrophication. At present, the commonly used denitrification process in the environmental protection field is still the biological denitrification process of nitrification and denitrification. According to different electron donors, the biological denitrification process can be divided into heterotrophic denitrification and autotrophic denitrification. Among them, heterotrophic denitrification uses carbon source as the electron donor, and under the action of denitrifying bacteria, it drives the conversion of nitrate into nitrogen gas, so as to achieve the purpose of denitrification. However, this denitrification method generally requires adding a large amount of organic matter to provide carbon source, with high cost. At the same time, there are also defects such as the secondary pollution problem of organic carbon source. In recent years, a new autotrophic denitrification process has been introduced in the environmental protection field, which uses elemental sulfur and sulfide instead of organic carbon source for denitrification to achieve nitrogen removal. This denitrification method does not require additional carbon source, does not have secondary pollution of carbon source, and produces less sludge, which not only reduces the operation cost of sewage treatment plants, but also reduces the floor area and carbon emissions. It is a new type of high-efficiency and low-carbon denitrification process.

[0003] At present, the mainstream sulfur autotrophic denitrification process often appears in the form of a denitrification filter, using elemental sulfur to make a degradable biological filler. Although this method has high total nitrogen removal accuracy, the sulfur-based filler itself has various problems:

[0004] (1) The strength of the filler itself is not high and it is extremely easy to break during the biodegradation process. The broken filler will be lost with the water, and the lost filler is easy to block the outlet pipeline, which not only reduces the denitrification efficiency but also increases the operation cost;

[0005] (2) A large number of microorganisms are attached to the filler. With the reproduction and metabolism of the microorganisms, the mycelium and extracellular proteins will stick the filler together. In order to ensure the removal accuracy of the filter, a large amount of filler is often put in at one time, resulting in large-scale hardening and blocking of the filler, affecting the denitrification efficiency. Summary of the Utility Model

[0006] Aiming at one or more deficiencies of the above-mentioned existing technologies, the utility model provides an internal circulation sulfur autotrophic denitrification reactor, which can improve the utilization rate of sulfur powder, reduce the operation cost, and increase the denitrification rate.

[0007] In order to achieve the above purpose, the utility model adopts the following technical scheme:

[0008] An internal circulation sulfur autotrophic denitrification reactor, comprising a reactor tank body, wherein a water inlet pipe, a mud-water separator and a water outlet pipe are arranged in the reactor tank body from bottom to top; a dissipation area is formed between the outer wall of the mud-water separator and the inner wall of the reactor tank body;

[0009] The mud-water separator comprises a baffle plate at the upper part and a vertical flow sedimentation tank at the lower part. The baffle plate is a cylindrical structure arranged above the vertical flow sedimentation tank. A baffle area is formed between the outer wall of the baffle plate and the inner wall of the vertical flow sedimentation pipe; the vertical flow sedimentation tank is a funnel structure, and a sedimentation area is formed inside. The top of the vertical flow sedimentation tank is immersed below the liquid level;

[0010] The mud-water mixture sedimented from the dissipation area first enters the baffle area. The water flow enters the sedimentation area from below the baffle plate. The clarified liquid after sedimentation flows out from the top of the baffle plate, and the sludge falls downward from the bottom of the vertical flow sedimentation tank to the bottom of the reactor tank body.

[0011] Preferably, the diameter of the baffle plate is smaller than the diameter of the top end of the vertical flow sedimentation tank, and the baffle plate and the vertical flow sedimentation tank are coaxially arranged.

[0012] Preferably, the bottom of the baffle plate extends below the top of the vertical flow sedimentation tank, and the sedimentation area is located below the bottom of the baffle plate.

[0013] Preferably, an overflow weir is arranged at the top of the baffle plate so that the treated wastewater can overflow evenly from the top of the mud-water separator.

[0014] Preferably, a water collecting tank is communicated with the outside of the overflow weir, and the water collecting tank is connected with the water outlet pipe.

[0015] Preferably, a reflux pipe is fixedly connected to the bottom of the vertical flow sedimentation tank. The reflux pipe is vertically arranged, and the sludge falls to the bottom of the reactor tank body through the reflux pipe.

[0016] Preferably, the bottom of the reflux pipe is 50 - 100 cm away from the top of the water distributor to ensure that the refluxed sludge and sulfur powder can be stirred and mixed by the water flow.

[0017] Preferably, the reactor tank body is a columnar structure, and the mud-water separator and the reactor tank body are coaxially arranged.

[0018] Preferably, the water inlet pipe is arranged at the bottom of the reactor tank body, and a water distributor is arranged inside the reactor tank body. The water inlet pipe is communicated with the water distributor.

[0019] Preferably, the water distributor comprises a plurality of pipes, and each pipe is connected with a plurality of water spraying openings with nozzles facing downward, which are used for stirring the sludge and sulfur powder at the bottom of the tank and mixing the mud-water and sulfur powder evenly to make the mixed mud-water flow upward.

[0020] By adopting the above technical solution, the beneficial effects of the utility model are as follows:

[0021] 1. The utility model arranges a mud-water separator in the reactor, and precipitates and recovers sulfur powder and sludge through the cooperation of a baffle and a vertical flow sedimentation tank, thereby avoiding the loss of fillers, improving the utilization rate of sulfur powder, and reducing the cost of fillers; at the same time, an annular gas escape zone is formed between the mud-water separator and the reactor tank body, and the nitrogen and sludge are separated by gas lift effect, which can avoid gas agitation of the sedimentation zone, further improving the effect of mud-water separation in the vertical flow sedimentation tank, thereby improving the utilization rate of sulfur powder.

[0022] 2. The utility model adopts sulfur powder instead of sulfur filler to provide sulfur element, which can avoid the compaction of filler and increase the contact area between reactant and sludge, thereby improving the denitrification rate.

[0023] 3. The water distributor provided in the utility model has a plurality of downward spray nozzles, which can fully stir and mix the sludge and sulfur powder that have settled and returned by the stirring effect of the water flow, and can further increase the rate of denitrification by flowing upward with the help of the water flow and air lift effect.

[0024] 4. The upflow reactor provided by the utility model is configured as a columnar structure, which can reduce the floor space and equipment cost compared with the traditional filter tank structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0026] Figure 1 It is a front view of an embodiment of the utility model;

[0027] Figure 2 It is a top view of an embodiment of the utility model.

[0028] In the figure: 1. Reactor tank; 2. Mud-water separator; 21. Vertical flow sedimentation tank; 22. Baffle; 3. Return pipe; 4. Water distributor; 5. Water inlet pipe; 6. Water outlet pipe; 7. Water collecting trough; 8. Overflow weir; 9. Baffle area; 10. Sedimentation area; 11. Evaporation area. DETAILED DESCRIPTION

[0029] It should be noted that the following detailed descriptions are all illustrative and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0030] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present utility model. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present utility model without creative efforts fall within the scope of protection of the present utility model.

[0031] Embodiment 1

[0032] In a typical embodiment of the present application, an internal circulation sulfur autotrophic denitrification reactor is provided. As Figure 1 , Figure 2 shown, it includes a reactor tank body 1 and a sludge-water separator 2 disposed inside the reactor tank body. The reactor takes in water from the bottom and discharges water from the top, and it is an upflow reactor.

[0033] Specifically, as Figure 1 shown, the reactor tank body 1 is a columnar structure, and inside it, a water inlet pipe 5, a water distributor 4, a reflux pipe 3, a sludge-water separator 2, an overflow weir 8, a collection tank 7, and a water outlet pipe 6 are arranged in sequence from bottom to top. Sulfur powder is placed at the bottom of the reactor tank body, and the sulfur powder can be added into the reactor tank body from the top or the sedimentation area.

[0034] Among them, the water inlet pipe 5 is connected to the water distributor 4. The water distributor is a branched water distribution structure arranged at the bottom of the reactor tank body. The water spraying ports of the water distributor 4 face downward, and the wastewater can be mixed with the sludge and sulfur powder at the bottom of the tank body. As Figure 1 shown, the water distributor 4 is arranged at the bottom of the reactor tank body 1 and is composed of multiple pipes fixed to the tank bottom. Each pipe is connected with multiple water spraying ports with nozzles facing downward. In this embodiment, by setting the water distributor, on the one hand, it can evenly distribute the sewage, and on the other hand, it can also stir the sludge and sulfur powder quickly through multiple water flows to make the mud and water mix evenly.

[0035] As Figure 1 shown, the reflux pipe 3 is a vertical pipe connected to the lower end of the sludge-water separator 2. The top of the reflux pipe 3 is communicated with the conical bottom of the vertical flow sedimentation tank 21. The lower end of the reflux pipe 3 is 500 mm above the water distributor 4, which can ensure that the refluxed sludge and sulfur powder can be stirred and mixed by the water flow, so as to achieve the purpose of uniform mixing.

[0036] As Figure 1As shown, the mud-water separator 2 is arranged at the middle position inside the reactor tank body. The outer diameter of the mud-water separator 2 is slightly smaller than the inner diameter of the reactor tank body 1. The area between the mud-water separator and the tank body is the dissipation area 11. Due to the air-lift effect, the sulfur powder and sludge carried by nitrogen rise to the water surface in the dissipation area 11, and then the nitrogen dissipates into the air. The sludge and sulfur powder settle down through the baffle area 9 and the sedimentation area 10, reach the bottom of the reactor tank body through the mud-water separator 2, and continue to react.

[0037] Specifically, the mud-water separator 2 has a two-layer structure. Combining Figure 1 、 Figure 2 As shown, the upper part of the mud-water separator 2 is provided with a cylindrical structure with openings at both ends, which is called a baffle plate. The bottom of the mud-water separator 2 is a conical funnel structure, which is called a vertical flow sedimentation tank. The bottom of the vertical flow sedimentation tank 21 is connected to the reflux pipe 3. Among them, the baffle plate 22 is arranged above the vertical flow sedimentation tank 21 and the diameter of the baffle plate is smaller than the diameter of the top opening of the vertical flow sedimentation tank. The top of the baffle plate 22 is above the liquid level, and the top of the vertical flow sedimentation tank 21 is immersed below the liquid level. The sludge and sulfur powder are driven by the water flow and complete the separation of mud and water through the outer wall of the baffle plate 22, and then enter the vertical flow sedimentation tank 21.

[0038] In this embodiment, the baffle plate 22 and the vertical flow sedimentation tank 21 are coaxially arranged and the bottom of the baffle plate 22 extends downward below the opening of the vertical flow sedimentation tank 21. Therefore, a baffle area 9 is formed between the outer wall of the baffle plate and the inner wall of the vertical flow sedimentation tank, and a sedimentation area 10 is formed inside the vertical flow sedimentation tank below the baffle plate. The mud-water mixture settling from the dissipation area 11 first enters the baffle area 9 and enters the sedimentation area 10 from below the baffle plate 22. The sludge and sulfur powder are separated from the water flow in the sedimentation area 10. Among them, the clear liquid rises from inside the baffle plate 22 and overflows from the overflow weir 8 at the top, and the sludge and sulfur powder settle downward to the bottom of the vertical flow sedimentation tank 21 and fall to the bottom of the tank through the reflux pipe 3.

[0039] As Figure 1 shown, the top of the mud-water separator 2 is provided with an overflow weir 8. The overflow weir 8 is a circular serrated ring plate, which is fixedly installed at the top of the baffle plate and can make the wastewater overflow evenly from the inside of the baffle plate to the outside. A water collecting tank 7 is connected to the outside of the overflow weir 8. The water collecting tank 7 is connected to the water outlet pipe 6. In this embodiment, the clear liquid separated from the sedimentation area rises upward, overflows through the overflow weir 8 into the water collecting tank 7, and then flows out of the reactor tank body through the water outlet pipe 6.

[0040] The working principle of the reactor in this embodiment is:

[0041] The wastewater enters the reactor tank body 1 through the water inlet pipe 5, is evenly distributed by the water distributor 4, and then sprays out from the lower spray nozzle, agitating the sludge and sulfur powder flowing down from the reflux pipe 3 at the bottom of the tank, and mixing the mud, water and sulfur powder evenly. The mixed mud and water flow upward evenly.

[0042] During the upward movement of the muddy water, Thiobacillus denitrificans in the sludge and the sulfur element provided by the sulfur powder act as reducing agents to reduce nitrate to nitrogen, playing a role in denitrification. The sludge and the unreacted sulfur powder rise to the liquid surface under the stripping action of the water flow and nitrogen. The nitrogen is stripped and escapes into the air through the stripping area 11. The sulfur powder and the sludge enter the baffle area 9 under the push of the water flow. Due to the blockage of the baffle plate 22, the sludge and the sulfur powder start to separate from the water flow in the sedimentation area 10. The clear liquid rises and converges into the collecting tank 7 through the overflow weir 8, and flows out of the reactor through the water outlet pipe 6 connected to the collecting tank 7. The sludge and the sulfur powder gradually settle to the bottom of the vertical flow sedimentation tank 21 and fall to the bottom of the reactor tank through the reflux pipe to be mixed with the wastewater again.

[0043] Example Two

[0044] In a sewage treatment plant for kitchen waste wastewater, the total nitrogen of the wastewater after membrane treatment is as high as 600 mg / L, the proportion of nitrate nitrogen is more than 90%, and the COD is only 200 mg / L. If the AO process is used for treatment, a large amount of carbon source needs to be added, and a large amount of sludge will be produced, which does not meet the requirements of energy conservation and environmental protection. At the site, the reactor in Example One is used for denitrification treatment after membrane treatment. A certain amount of sulfur powder is added to the sedimentation area through the tank top as a reaction substrate, and domestic sludge accounting for 10% of the reactor volume is put in as the strain. The wastewater is pumped into the bottom water inlet pipe by a centrifugal pump, and the influent water is evenly distributed by the water distributor. The influent flow rate of the wastewater is adjusted to ensure that the wastewater retention time is 2 - 3 h, and a certain amount of sulfur powder is supplemented daily according to the influent water volume and total nitrogen data. The wastewater is mixed with the sulfur powder during the upward movement, and under the action of Thiobacillus denitrificans, nitrate is reacted into nitrogen. The treated wastewater flows out of the reactor through the collecting tank and the water outlet pipe, and the total nitrogen of the effluent is controlled below 40 mg / L.

[0045] Example Three

[0046] In a sewage treatment plant for photovoltaic wastewater, the influent COD is 250 mg / L, the total nitrogen is 350 mg / L, and the nitrate nitrogen is 300 mg / L. The reactor in Example One is used to treat the wastewater. The wastewater is pumped into the reactor by a centrifugal pump, and a certain amount of sulfur powder is put in according to the daily water volume. The overall retention time of the reactor is 4 h. After sulfur autotrophic denitrification, the total nitrogen of the effluent is reduced to below 45 mg / L.

[0047] It should be noted that the above examples are only used to illustrate the technical solutions of the present invention, rather than to limit it. Those of ordinary skill in the art should understand that the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An internal circulation sulfur autotrophic denitrification reactor, characterized in that: It comprises a reactor tank body, wherein a water inlet pipe, a mud-water separator and a water outlet pipe are arranged from bottom to top in the reactor tank body; a dissipation zone is formed between the outer wall of the mud-water separator and the inner wall of the reactor tank body; The mud-water separator includes an upper baffle and a lower vertical flow sedimentation tank. The baffle is a cylindrical structure arranged above the vertical flow sedimentation tank, and a baffle area is formed between the outer wall of the baffle and the inner wall of the vertical flow sedimentation tank. The vertical flow sedimentation tank is a funnel structure with a sedimentation area formed inside, and the top of the vertical flow sedimentation tank is submerged below the liquid surface.

2. The internal circulation sulfur autotrophic denitrification reactor according to claim 1, characterized in that: The diameter of the baffle is smaller than the top diameter of the vertical flow sedimentation tank, and the baffle is coaxially arranged with the vertical flow sedimentation tank.

3. An internal circulation sulfur autotrophic denitrification reactor as claimed in claim 2, characterized in that: The bottom of the baffle extends below the top of the vertical flow sedimentation tank, and the sedimentation zone is located below the bottom of the baffle.

4. The internal circulation sulfur autotrophic denitrification reactor according to claim 1, characterized in that: An overflow weir is arranged on the top of the baffle.

5. An internal circulation sulfur autotrophic denitrification reactor as claimed in claim 4, characterized in that: The outer side of the overflow weir is connected to a water collecting tank, and the water collecting tank is connected to the water outlet pipe.

6. The internal circulation sulfur autotrophic denitrification reactor according to claim 1, characterized in that: The bottom of the vertical flow sedimentation tank is fixedly connected with a return pipe, which is arranged vertically, and the sludge falls to the bottom of the reactor tank through the return pipe.

7. An internal circulation sulfur autotrophic denitrification reactor as claimed in claim 6, characterized in that: The water inlet pipe is arranged at the bottom of the reactor tank body, a water distributor is arranged inside the reactor tank body, and the water inlet pipe is communicated with the water distributor.

8. An internal circulation sulfur autotrophic denitrification reactor as claimed in claim 7, characterized in that: The bottom of the reflux pipe is 50-100 cm away from the top of the water distributor.

9. The internal circulation sulfur autotrophic denitrification reactor according to claim 7, characterized in that: The water distributor comprises a plurality of pipes, each of which is connected with a plurality of water spraying ports with nozzles pointing downwards.

10. The internal circulation sulfur autotrophic denitrification reactor according to claim 1, characterized in that: The reactor tank body is a columnar structure, and the mud-water separator is coaxially arranged with the reactor tank body.

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