Low-carbon-nitrogen-ratio sewage treatment device

Abstract

The utility model relates to the technical field of sewage treatment, and provides a low-carbon-nitrogen-ratio sewage treatment device, which is formed by sequentially communicating an anaerobic zone, an anoxic zone and an aerobic zone, is used for treating low-carbon-nitrogen-ratio sewage, and is characterized by further comprising a multifunctional zone arranged at the tail end of the aerobic zone and used for adjusting the oxygen content of the sewage entering the multifunctional zone; the settling pond is arranged at the tail end of the multifunctional area and is used for settling the treated sewage. According to the technical scheme, the problems that the treatment capacity is limited and only specific sewage can be treated due to fixed process conditions during sewage treatment in the prior art are solved.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, specifically to a wastewater treatment device with a low carbon-to-nitrogen ratio. Background Technology

[0002] Regarding the current A 2 In the O (anaerobic, anoxic, aerobic) process for treating wastewater with a low C / N ratio, a large amount of carbon source is added, resulting in abundant aeration at the end of the aerobic zone and a lack of nutrients, leading to high dissolved oxygen levels. This results in high dissolved oxygen in the mixed liquor returned from the aerobic zone to the anaerobic / anoxic zone, consuming the carbon source in the anaerobic / anoxic zone and wasting it. Furthermore, the total nitrogen removal rate depends on the amount of nitrified liquor returned from the aerobic zone, requiring a large amount of return to ensure adequate total nitrogen removal. This is in contrast to traditional A... 2 Due to issues with the O process, AOA (anaerobic-aerobic-anoxic process) has emerged as a novel improved technology. Under low C / N ratio influent conditions, an anoxic section is added at the end of the aerobic zone to reduce dissolved oxygen in the system and lower the dissolved oxygen concentration in the return system, thereby preventing the nitrification of carbon sources due to high dissolved oxygen in the upstream anaerobic zone. However, regardless of A... 2 Both O and AOA processes, when operating in low C / N ratio water with changing water quality, suffer from the problem of relatively fixed process conditions that cannot be flexibly adjusted, resulting in a lack of flexibility in response to changes in water quality.

[0003] Literature reports that when the influent COD / TN ratio is greater than 8, the denitrification effect is high, and the system can achieve total nitrogen removal without the need for additional carbon source. Currently, due to the presence of industrial water in some domestic water and leakage problems in the drainage network, the COD / TN ratio of water treatment plants is low. To achieve the total nitrogen discharge standard (total nitrogen less than or equal to 15 mg / L, with even lower requirements in some areas), a certain amount of carbon source must be added. In municipal wastewater treatment plants, when the COD / TN ratio is lower than the theoretical value, carbon source addition is required for operation. The AOA process is a commonly used process for water with a low COD / TN ratio in recent years. Agitators are installed in the anoxic zone to mix the sludge and water and prevent sludge sedimentation, while aerators are installed in the aerobic zone to provide the oxygen needed for microbial production while also preventing sludge sedimentation. However, when high ammonia nitrogen water enters the system, insufficient volume in the aerobic zone can easily lead to ammonia nitrogen levels failing to meet standards. Therefore, it is essential to modify the anoxic zone at the end of the AOA process into a tank type that allows for aerobic-anoxic adjustment. The conventional method for this conversion is to simultaneously install agitators and aeration heads in the anoxic zone, activating the aeration heads when oxygen is needed. However, this technique has a problem: with the agitator and aeration heads installed simultaneously in the tank, the thrust and torque generated by the agitation can damage the aeration heads (which are typically made of engineering plastic). Once an aeration head is damaged, the blower's airflow escapes through the damaged pipes, resulting in high air resistance at other aeration head locations, preventing gas aeration and severely impacting the aeration effect, potentially causing system damage. Utility Model Content

[0004] This invention proposes a low carbon-to-nitrogen ratio wastewater treatment device, which solves the problems in related technologies where fixed process conditions during wastewater treatment lead to limited treatment capacity and weak ability to adjust to changes in low carbon-to-nitrogen ratio and influent conditions.

[0005] The technical solution of this utility model is as follows:

[0006] A low carbon-to-nitrogen ratio wastewater treatment device, comprising an anaerobic zone, an anoxic zone, and an aerobic zone connected in sequence, for treating wastewater with a low carbon-to-nitrogen ratio, further comprising:

[0007] A multi-functional zone is located on one side of the aerobic zone. The multi-functional zone is used to increase the volume of the aerobic zone or as a hypoxic process section.

[0008] A sedimentation tank is located on one side of the multi-functional area, and the sedimentation tank is used to settle the treated mud-water mixture.

[0009] As a further technical solution, it also includes:

[0010] The first return pipe is installed at both ends on the multifunctional zone and the anoxic zone, respectively. The first return pipe is used to return the mud-water mixture in the multifunctional zone into the anoxic zone so that the nitric acid generated at the end of the aerobic process is returned to the anoxic zone to carry out the denitrification reaction, and the nitrate is converted into nitrogen gas and discharged.

[0011] As a further technical solution, it also includes:

[0012] The second return pipe is installed on the sedimentation tank at one end and connected to the anaerobic zone and the anoxic zone at the other end. It is used to replenish the sludge concentration of the system and at the same time realize the return of nitrate in the sedimentation tank to the front end of the system for denitrification reaction.

[0013] A control valve is installed on the second return pipe, and the control valve is used to control the amount of sludge returned from the second return pipe to the anaerobic zone and the anoxic zone.

[0014] As a further technical solution, it also includes:

[0015] A plurality of gas-liquid mixing jet devices are arranged within the multifunctional zone, and the gas-liquid mixing jet devices are used to regulate the dissolved oxygen content within the multifunctional zone.

[0016] As a further technical solution, the gas-liquid mixing jet device includes:

[0017] A gas-liquid mixing jet pump, wherein the gas-liquid mixing jet pump has an inlet end and an outlet end;

[0018] The regulating pipeline has two sections, which are respectively connected to the water inlet and the water outlet.

[0019] An air intake regulating valve is installed on the regulating pipeline connected to the water inlet end, and the air intake regulating valve is used to introduce air into the regulating pipeline.

[0020] As a further technical solution, it also includes:

[0021] A gas-liquid cutting cylinder is installed on the regulating pipeline connected to the water outlet. The gas-liquid cutting cylinder is located between the gas-liquid mixing jet device and the multi-functional area. The gas-liquid cutting cylinder is used to mix the liquid and gas entering the regulating pipeline.

[0022] As a further technical solution, several of the gas-liquid mixing jet devices are arranged at equal intervals and staggered within the multifunctional area, and the direction of flow into the multifunctional area can be adjusted according to the actual situation.

[0023] The working principle and beneficial effects of this utility model are as follows:

[0024] In this utility model, the original A 2 The O process incorporates a multi-functional zone at its end. This zone allows for flexible adjustment of the oxygen content of the incoming wastewater, preventing excessive dissolved oxygen levels in the mixed liquor returned from the aerobic zone to the anaerobic and anoxic zones. This reduces carbon source consumption in the anaerobic and anoxic zones, improving carbon source utilization efficiency. The sedimentation tank effectively settles the treated wastewater, resulting in clearer water and improved treatment effectiveness and effluent quality. The entire system, with its interconnected anaerobic, anoxic, and aerobic zones, along with the multi-functional zone and sedimentation tank, forms a complete wastewater treatment system effectively addressing the treatment needs of wastewater with low carbon-to-nitrogen ratios. Attached Figure Description

[0025] The preferred embodiments will be described below in a clear and easy-to-understand manner, in conjunction with the accompanying drawings, to further explain the above-mentioned characteristics, technical features, advantages and implementation methods of this utility model.

[0026] Figure 1 This is a schematic diagram of the structure of the anaerobic zone, anoxic zone, aerobic zone, multifunctional zone, and sedimentation zone in this utility model;

[0027] Figure 2 This is a simplified structural diagram of the multifunctional area in this utility model;

[0028] Figure 3 This is a simplified structural diagram of the gas-liquid mixing jet device and its regulating pipeline in this utility model.

[0029] In the diagram: 1. Anaerobic zone, 2. Anoxic zone, 3. Aerobic zone, 4. Multifunctional zone, 5. Sedimentation tank, 6. First return pipe, 7. Second return pipe, 8. Control valve, 9. Gas-liquid mixing jet device, 90. Gas-liquid mixing jet pump, 901. Water inlet, 902. Water outlet, 10. Regulating pipeline, 11. Air inlet regulating valve, 12. Gas-liquid cutting cylinder. Detailed Implementation

[0030] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the specific implementation methods of this utility model will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are merely some embodiments of this utility model. For those skilled in the art, they can be understood as further technical solutions without creative effort. In some drawings, components with the same structure or function are only schematically illustrated, or only one is marked. In this document, "a" not only means "only one," but can also mean "more than one," and "several" includes "two" and "more than two."

[0031] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0032] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0033] Reference Figures 1-3 This is the first embodiment of the present invention, which proposes a low carbon-to-nitrogen ratio wastewater treatment device, wherein an anaerobic zone 1, an anoxic zone 2 and an aerobic zone 3 are connected in sequence for treating wastewater with a low carbon-to-nitrogen ratio. It also includes: a multi-functional zone 4 set on one side of the aerobic zone 3, which is used to increase the volume of the aerobic zone 3 or to be used as an anoxic process section; and a sedimentation tank 5 set on one side of the multi-functional zone 4, which is used to settle the treated mud-water mixture.

[0034] In this embodiment, in the existing treatment device, the main pollutant in the influent is ammonia nitrogen. Ammonia nitrogen requires nitrifying bacteria to convert it into nitrate or nitrite under aerobic conditions through nitrification. Nitrate or nitrite then undergoes denitrification in an anaerobic environment, using organic matter as an electron donor, converting it into nitrogen gas, which is then released into the air. Because denitrification requires organic matter as an electron donor, the organic matter content is low after the aerobic reaction. To fully utilize the carbon source in the influent, the process typically places the anoxic zone 2 at the front end and the aerobic zone 3 at the end. Nitrified liquid is returned to the anoxic zone 2 for further denitrification, ultimately achieving total nitrogen removal. Literature reports that when the influent COD / TN ratio is greater than eight, the denitrification effect is high, and the system can achieve total nitrogen removal without supplementing the carbon source. Currently, due to the presence of industrial water in some domestic water and leakage problems in the drainage network, the COD / TN ratio of the water plant influent is low. To achieve the total nitrogen discharge standard, a certain amount of carbon source must be added.

[0035] In this plan, the original A 2 An equalization tank is added at the end of the O process. The equalization tank can be used as a further technical solution to recirculate the mud-water mixture in the multifunctional zone 4 into the anoxic zone 2, so that the nitric acid generated at the end of the aerobic process can be recirculated to the anoxic zone 2 for denitrification, and the nitrate is converted into nitrogen gas and discharged.

[0036] As a further technical solution, it also includes: the two ends of the first return pipe 6 are respectively set on the multifunctional zone 4 and the anoxic zone 2. The first return pipe 6 is used to return the mud-water mixture in the multifunctional zone 4 into the anoxic zone 2 so that the nitric acid generated at the end of the aerobic process is returned to the anoxic zone 2 to carry out the denitrification reaction, and the nitrate is converted into nitrogen gas and discharged.

[0037] In this embodiment, the first return pipe 6 returns the wastewater from the multifunctional zone 4 to the anoxic zone 2, which helps to improve the efficiency of the denitrification reaction and further remove nitrogen from the wastewater. By flexibly adjusting the flow rate of the returned wastewater, the operating conditions of the anoxic zone 2 can be optimized according to the influent water quality and treatment requirements, thereby enhancing the adaptability of the entire treatment device to changes in water quality.

[0038] As a further technical solution, it also includes: one end of the second return pipe 7 is set on the sedimentation tank 5, and the other end is connected to the anaerobic zone 1 and the anoxic zone 2 respectively, which is used to supplement the sludge concentration of the system, and at the same time realize the return of nitrate in the sedimentation tank 5 to the front of the system for denitrification reaction; the control valve 8 is set on the second return pipe 7, and the control valve 8 is used to control the amount of sludge returned by the second return pipe 7 to the anaerobic zone 1 and the anoxic zone 2.

[0039] In this embodiment, the second return pipe 7 allows the sludge in the sedimentation tank 5 to be returned to the anaerobic zone 1 and the anoxic zone 2, preventing sludge loss and achieving nitrate nitrogen return, thus improving the removal efficiency of pollutants. The control valve 8 can flexibly control the flow direction of the second return pipe 7, accurately distributing the return liquid to the anaerobic zone 1 or the anoxic zone 2 according to the actual water quality and treatment requirements, thereby optimizing the reaction conditions of each tank.

[0040] As a further technical solution, it also includes: a plurality of gas-liquid mixing jet devices 9 are arranged in the multifunctional zone 4, and the gas-liquid mixing jet devices 9 are used to regulate the amount of dissolved oxygen in the multifunctional zone 4.

[0041] In this embodiment, the arrangement of several gas-liquid mixing jet devices 9 enables more uniform and effective regulation of the oxygen content of wastewater within the multi-functional zone 4, ensuring the accuracy and stability of oxygen content regulation. The gas-liquid mixing jet devices 9 can rapidly mix wastewater and air, improving oxygen dissolution efficiency and thus quickly regulating the oxygen content, thereby increasing wastewater treatment efficiency. The gas-liquid mixing jet devices 9 operate relatively stably, have low maintenance costs, and can adapt to different water flow conditions and water quality changes within the multi-functional zone 4.

[0042] As a further technical solution, the gas-liquid mixing jet device 9 includes: a gas-liquid mixing jet pump 90 having an inlet end 901 and an outlet end 902; two regulating pipes 10, which are respectively connected to the inlet end 901 and the outlet end 902; and an air inlet regulating valve 11 installed on the regulating pipe 10 connected to the inlet end 901, which is used to introduce air into the regulating pipe 10.

[0043] In this embodiment, the gas-liquid mixing jet device 9 is located inside the multi-functional regulating tank, and the water pump inlet pipe is very short and submerged below the liquid surface of the multi-functional tank, just like the water pump. The air inlet pipe is located above the liquid surface and is equipped with an air inlet valve. The regulating pipe 10 connects the multi-functional zone 4 to the gas-liquid mixing jet device 9, ensuring that oxygen can be smoothly introduced into the multi-functional zone 4, providing an effective channel for adjusting the oxygen content. The air inlet regulating valve 11 can precisely control the amount of air entering the regulating pipe 10, thereby achieving fine adjustment of the oxygen content in the multi-functional zone 4 to meet different treatment needs. The air intake can be flexibly adjusted according to the real-time oxygen content of the wastewater and treatment requirements, improving the flexibility and accuracy of oxygen content adjustment.

[0044] As a further technical solution, it also includes: the gas-liquid cutting cylinder 12 is installed on the regulating pipe 10 connected to the water outlet 902, the gas-liquid cutting cylinder 12 is located between the gas-liquid mixing jet device 9 and the multi-functional area 4, and the gas-liquid cutting cylinder 12 is used to mix the liquid and gas entering the regulating pipe 10.

[0045] In this embodiment, the gas-liquid cutting cylinder 12 allows for thorough mixing of the liquid and gas entering the regulating pipe 10, ensuring uniform oxygen dispersion in the wastewater and improving oxygen utilization efficiency. This also makes the gas-liquid mixing within the regulating pipe 10 more uniform and stable, ensuring more consistent oxygen content in each area of ​​the multi-functional zone 4 and preventing excessively large local differences in oxygen content. Furthermore, it enhances the regulating effect of the gas-liquid mixing jet device 9 on the oxygen content of wastewater, making the regulation process more stable and efficient.

[0046] As a further technical solution, several gas-liquid mixing jet devices 9 are arranged at equal intervals and staggered in the multifunctional zone 4, and the direction of flow into the multifunctional zone 4 can be adjusted according to the actual situation.

[0047] In this embodiment, in A 2 The O process adds an anoxic zone 2 at the end. The key technical improvement lies in replacing the traditional anoxic zone 2, which is designed for stirring, with an equally spaced gas-liquid mixing jet device 9. The inlet 901 of the gas-liquid mixing jet device 9 has an air inlet and a valve. When the influent ammonia nitrogen is high and the preceding aerobic zone 3 is insufficient to meet nitrification requirements, the air intake valve at the inlet of the gas-liquid mixing jet device 9 is opened. The negative pressure of the gas-liquid mixing jet device 9 introduces air and influent into the device, achieving gas-liquid mixing and transforming anoxic zone 2 into aerobic zone 3. When ammonia nitrogen and nutrients are low, the air intake valve in anoxic zone 2 is closed, and the gas-liquid mixing jet device 9 only serves a stirring function. Depending on the water quality conditions, some air intake valves of the gas-liquid mixing jet device 9 can be opened to achieve localized aerobic conditions. A portion of the nitrified liquor from aerobic zone 3 undergoes denitrification in the terminal anoxic zone 2. The nitrified liquor recirculation is set in the second anoxic zone 2, which enables a portion of the nitrified liquor to be recirculated back to the upstream anoxic process section, reducing the dissolved oxygen in the upstream anoxic zone 2, avoiding carbon source waste, and also reducing the carbon source and nitrified liquor recirculation flow.

[0048] The gas-liquid mixing jet device 9 flows into the multi-functional zone 4 in different directions, creating a more complex and turbulent flow pattern within the zone. This promotes thorough mixing of wastewater and oxygen, improving the efficiency and uniformity of oxygen content regulation. The different jet directions reduce dead zones, ensuring effective oxygen supply to all areas within the multi-functional zone 4 and preventing localized hypoxia or hyperxia. This multi-directional jetting enhances mass transfer within the multi-functional zone 4, accelerating oxygen dissolution and diffusion in the wastewater, thus achieving the desired oxygen content level more quickly. It also helps improve the volumetric utilization rate of the multi-functional zone 4, allowing the entire space to function optimally and optimizing wastewater treatment. Furthermore, it adapts to different influent conditions and treatment requirements, enhancing the overall wastewater treatment system's ability to respond to changes in water quality by flexibly adjusting the direction and operating combinations of the gas-liquid mixing jet device 9.

[0049] It should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A low carbon-nitrogen ratio sewage treatment device, which is characterized in that, for treating low carbon-nitrogen ratio sewage, an anaerobic zone (1), an anoxic zone (2) and an aerobic zone (3) are sequentially communicated. Also include: Multifunctional area (4) is arranged on one side of the aerobic zone (3), the multifunctional area (4) is used to increase the volume of the aerobic zone (3) or as an anoxic process section; Sedimentation tank (5) is arranged on one side of the multifunctional area (4), the sedimentation tank (5) is used for sedimentation of the treated sludge mixture.

2. The low C / N ratio sewage treatment device according to claim 1, wherein Also include: The first reflux pipe (6) is arranged on the multifunctional area (4) and the anoxic zone (2) respectively, and the first reflux pipe (6) is used for refluxing the sludge mixture in the multifunctional area (4) into the anoxic zone (2) to realize the reflux of nitric acid generated at the end of the aerobic zone (2) to the anoxic zone (2) for denitrification reaction, and nitrate is changed into nitrogen gas.

3. The low C / N ratio sewage treatment device according to claim 1, wherein Also include: The second reflux pipe (7) is arranged on the sedimentation tank (5), and the other end is communicated with the anaerobic zone (1) and the anoxic zone (2) respectively, which is used for supplementing the sludge concentration of the system, and realizing the reflux of nitrate in the sedimentation tank (5) to the front end of the system for denitrification reaction; Control valve (8) is arranged on the second reflux pipe (7), the control valve (8) is used for controlling the amount of sludge refluxed to the anaerobic zone (1) and the anoxic zone (2) by the second reflux pipe (7).

4. The low C / N ratio sewage treatment device according to claim 1, wherein Also include: Gas-liquid mixed jet device (9) is arranged in the multifunctional area (4), the gas-liquid mixed jet device (9) is used for adjusting the dissolved oxygen content in the multifunctional area (4).

5. A low C:N ratio sewage treatment apparatus according to claim 4, wherein The gas-liquid mixed jet device includes: Gas-liquid mixed jet pump (90), the gas-liquid mixed jet pump (90) has water inlet end (901) and water outlet end (902); Adjusting pipeline (10) has two, which are communicated with the water inlet end (901) and the water outlet end (902) respectively; Air inlet adjusting valve (11) is arranged on the adjusting pipeline (10) communicated with the water inlet end (901), the air inlet adjusting valve (11) is used for aeration in the adjusting pipeline (10).

6. A low C:N ratio sewage treatment apparatus according to claim 5, wherein Also include: Gas-liquid cutting cylinder (12) is arranged on the adjusting pipeline (10) connected with the water outlet end (902), the gas-liquid cutting cylinder (12) is located between the gas-liquid mixed jet device (9) and the multifunctional area (4), the gas-liquid cutting cylinder (12) is used for mixing the liquid and gas entering the adjusting pipeline (10).

7. A low C:N ratio sewage treatment apparatus according to claim 4, wherein Several gas-liquid mixed jet devices (9) are arranged in the multifunctional area (4) at equal intervals, and the direction of the sludge mixture flowing into the multifunctional area (4) can be adjusted according to actual situation.

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