Sewage deep denitrification system

Abstract

The utility model discloses a sewage deep denitrification system, which is characterized in that an NH3-N on-line detector and a CODCr on-line detector are arranged in a grit chamber water outlet well, the grit chamber water outlet well is connected with a first water pump, and the first water pump is connected with a first reactor through a pipeline with a flowmeter. The grit chamber water outlet well is also connected with a second water pump; the second water pump is connected with the second reactor through a pipeline with a flow meter. The sand pool water outlet well is further connected with a biochemical system through a pipeline with a flow meter, and a water outlet of the biochemical system is connected with the first reactor through a pipeline with a flow meter and a nitrate nitrogen online detector. And the overflow weir of the first reactor is connected with the intermediate tank through a pipeline with a control valve. The middle tank is connected with the second reactor through a water pump and a flowmeter; and the middle tank is provided with an online detector. According to the device disclosed by the utility model, nitrate nitrogen generated in anaerobic ammonia oxidation reaction can be thoroughly removed on the premise of not additionally adding a carbon source, and the total nitrogen removal rate of treated sewage is greatly improved.

Description

Technical Field

[0001] This utility model belongs to the field of wastewater treatment and relates to a wastewater denitrification system. Background Technology

[0002] Due to its relatively good nitrogen and phosphorus removal effect, the anaerobic-anoxic-oxic biological nitrogen and phosphorus removal process is now widely used in secondary and tertiary wastewater treatment and reclaimed water treatment in China.

[0003] Wastewater influent typically has a low carbon-to-nitrogen ratio, necessitating the addition of organic carbon sources in the AAO (Anaerobic-Oxygenation) stage to achieve this low ratio. Another method to reduce the carbon-to-nitrogen ratio is to add denitrification filters and introduce carbon sources within them. The main drawbacks of these two methods are that the increased amount of carbon source added raises wastewater treatment costs and leads to increased sludge production and carbon emissions. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a deep denitrification system for wastewater that can effectively improve the nitrogen removal rate of the wastewater treatment system without adding an external carbon source.

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

[0006] The wastewater deep denitrification system includes a grit chamber effluent well, a first reactor, an intermediate tank, a second reactor, and a biological treatment system. The grit chamber effluent well is equipped with an online NH3-N detector and a first COD detector. Cr Online monitoring device; the effluent well of the grit chamber is connected to a first water pump, which is connected to a first reactor via a pipeline equipped with a first flow meter; the effluent well of the grit chamber is connected to a second water pump, which is connected to a second reactor via a pipeline equipped with a second flow meter; the effluent well of the grit chamber is connected to a biological system via a pipeline equipped with a third flow meter, and the outlet of the biological system is connected to the first reactor via a pipeline equipped with a fourth flow meter and an online nitrate nitrogen monitor; the first reactor is equipped with a first overflow weir, which is connected to an intermediate tank via a pipeline equipped with a control valve; the intermediate tank is connected to a third water pump, which is connected to the second reactor via a pipeline equipped with a fifth flow meter; the intermediate tank is equipped with... Online testing instrument.

[0007] Preferably, the first reactor is a short-cut denitrification reactor; the first reactor includes a tank body connected to a blower pipe; the tank body is equipped with a bottom aeration system, a first dissolved oxygen detector, and fixed biological carrier packing.

[0008] Preferably, the second reactor is an anaerobic ammonia oxidation coupled with endogenous denitrification reactor; the second reactor includes a tank body, which is equipped with a submersible agitator, a suspended biological carrier packing material and a second dissolved oxygen detector.

[0009] Preferably, the second reactor is provided with a second overflow weir; the discharge end of the second overflow weir is used to connect to the deep treatment system.

[0010] More preferably, the second overflow weir is provided with a microbial carrier mesh.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] This system utilizes a novel approach to denitrify nitrate nitrogen in secondary biological treatment wastewater into nitrite nitrogen via short-cut denitrification. It then employs anaerobic ammonia oxidation coupled with endogenous denitrification to treat the wastewater treatment plant's influent, achieving deep nitrogen removal. This system eliminates the need for carbon source addition, further increasing the nitrate nitrogen concentration in the wastewater treatment plant's biological treatment effluent. The system adjusts and mixes the effluent from the secondary biological treatment plant with the raw water, using a short-cut denitrification process with some organic matter from the raw water as a carbon source to denitrify nitrate nitrogen into nitrite nitrogen. The ratio of nitrite nitrogen to ammonia nitrogen produced by short-cut denitrification is further adjusted with a portion of the raw water to meet the requirements of anaerobic ammonia oxidation, efficiently removing total nitrogen. Simultaneously, the coupled endogenous denitrification process completely removes the nitrate nitrogen produced during anaerobic ammonia oxidation, significantly improving the total nitrogen removal rate of the treated wastewater. Attached Figure Description

[0013] Figure 1 This is a schematic diagram illustrating the structure and working principle of an embodiment of the present invention.

[0014] Figure 2 This is a schematic diagram of the structure of the first reactor in a system embodiment of this utility model.

[0015] Figure 3 This is a schematic diagram of the structure of the second reactor in an embodiment of the present invention.

[0016] Explanation of reference numerals in the attached figures:

[0017] 1. Sedimentation tank effluent well; 1-1. NH3-N online detector; 1-2. First COD meter Cr 1. Online monitoring instrument; 2. First water pump; 3. First flow meter; 4. First reactor; 4-1. First overflow weir; 4-2. Bottom aeration system; 4-3. First dissolved oxygen detector; 4-4. Fixed biological carrier packing material; 4-5. Blower pipe; 5. Intermediate tank; 5-1. 6. Online monitoring instrument; 7. Third water pump; 8. Fifth flow meter; 9. Second reactor; 10. Second overflow weir; 11. Submersible agitator; 12. Suspended biological carrier packing material; 13. Second dissolved oxygen detector; 14. Online detection instrument, 8-6, second COD Cr 9. Online monitoring instrument, 10. Second flow meter, 11. Second water pump, 12. Biochemical system, 13. Third flow meter, 14. Nitrate nitrogen online monitoring instrument, 15. Fourth flow meter. Detailed Implementation

[0018] The present invention will be further described below with reference to specific embodiments and accompanying drawings.

[0019] The wastewater treatment system of this embodiment includes a grit chamber as a primary treatment system, connected to a grit chamber effluent well 1, a biochemical system 11 as a secondary treatment system, and a tertiary advanced treatment system. The advanced treatment system includes a booster pump station connected to a chemical sedimentation tank via an intermediate booster pump, and the chemical sedimentation tank connected to a sand filter.

[0020] like Figure 1 The embodiment of the wastewater deep denitrification system of this utility model includes a sedimentation tank effluent well 1, a first reactor 4, an intermediate tank 5, a second reactor 8, and a biochemical system 11.

[0021] The sedimentation tank effluent well 1 is equipped with an online NH3-N detector 1-1 and a first COD detector. Cr Online monitoring instruments 1-2. The sedimentation tank effluent well 1 is connected to a first water pump 2 via a pipeline. The first water pump 2 is connected to the first inlet of the first reactor 4 via a pipeline equipped with a first flow meter 3. The sedimentation tank effluent well 1 is also connected to a second water pump 10 via a pipeline. The second water pump 10 is connected to the first inlet of the second reactor 8 via a pipeline equipped with a second flow meter 9.

[0022] The first water pump 2 and the first flow meter 3 are used to measure and control the amount of raw water entering the first reactor 4 from the grit chamber effluent well 1. The second water pump 10 and the second flow meter 9 are used to measure and control the amount of raw water entering the second reactor 8 from the grit chamber effluent well 1. An online NH3-N detector 1-1 and a first COD... Cr Online monitoring instruments 1-2 provide data for metering and controlling the flow rates entering the second and first reactors. Specifically, the second reactor adjusts the flow rate of the second pump 10 based on the data from the NH3-N online monitoring instrument 1-1, and the first reactor adjusts the flow rate based on the data from the first COD... Cr The online monitoring instrument 1-2 controls the flow rate of the first water pump 2 based on the data.

[0023] The sedimentation tank effluent well 1 is also connected to the inlet of the biological system 11 via a pipeline equipped with a third flow meter 12. The outlet of the biological system 11 is connected to the second inlet of the first reactor 4 via a pipeline equipped with a fourth flow meter 14 and an online nitrate nitrogen detector 13. The fourth flow meter 14 and the online nitrate nitrogen detector 13 are used to measure the amount of nitrate nitrogen entering the first reactor 4.

[0024] Combination Figure 2 The first reactor 4 is equipped with a first overflow weir 4-1. The discharge end of the first overflow weir 4-1 is connected to the inlet of the intermediate tank 5 via a pipeline with a control valve. The intermediate tank 5 is connected to a third water pump 6 via a pipeline. The third water pump 6 is connected to the second inlet of the second reactor 8 via a pipeline with a fifth flow meter 7. The intermediate tank 5 is also equipped with... Online monitoring instrument 5-1. The function of the fifth flow meter 7 is to measure the influent flow rate to the second reactor 8 in each cycle. Combined with the flow rate from the fifth flow meter 7, the flow rate entering the second reactor 8 in each cycle is calculated. The amount.

[0025] Combination Figure 3 The second reactor 8 is provided with a second overflow weir 8-1, and the discharge end of the second overflow weir 8-1 is connected to the booster pump room of the deep treatment system through a pipeline.

[0026] Furthermore, such as Figure 2 The first reactor 4 includes a tank body connected to a blower pipe 4-5 for blowing air into the reactor 4 via a blower. A first overflow weir 4-1 is located on the outer side of the upper end of the tank body to control the water level in the reactor 4, thereby controlling the hydraulic retention time. The tank body is equipped with a bottom aeration system 4-2 and a first dissolved oxygen detector 4-3. The bottom aeration system 4-2 and the first dissolved oxygen detector 4-3 work together to control the dissolved oxygen system in the reactor 4, maintaining it within a set range. The tank body contains a fixed biological carrier packing material 4-4 for short-range denitrifying microorganisms to attach to. The first reactor 4 is a coexistence system of biofilm and suspended sludge. The fixed biological carrier packing material 4-4 can significantly increase the concentration of microorganisms and improve reaction efficiency. The fixed biological carrier packing material 4-4 is made from a copolymer of polypropylene and polyethylene, modified with appropriate hydrophilicity, biocompatibility, and charge, with a filling volume ratio of 20-30%, and is model BZ50-S with a specific surface area of ​​5600 m². 2 / m 3 .

[0027] like Figure 3The second reactor 8 includes a tank body. A second overflow weir 8-1 is provided on the outer side of the upper end of the tank body, its function being to allow the second reactor 8 to operate intermittently. The second overflow weir 8-1 is equipped with a microbial carrier mesh to prevent the microbial carrier from flowing out. A submersible agitator 8-2 is installed inside the tank body to ensure sufficient contact between the microbial carrier and the wastewater within the second reactor 8. The tank body contains suspended biological carrier packing material 8-3, made of HDPE, meeting the standard of "High-Density Polyethylene Suspended Carrier Packing for Water Treatment" (CJ / T461-2014), with a diameter of 25mm and a specific surface area of ​​800m². 2 / m 3 Density 0.94~0.97 kg / m³ 3 The volume ratio of the filling is 15-20%. A second dissolved oxygen detector 8-4 is installed in the tank to detect the dissolved oxygen inside the second reactor 8. The tank is equipped with... Online detector 8-5 and second COD Cr Online detectors 8-6 are used to detect the reaction ends of the second reactor 8. Value and COD Cr The concentration.

[0028] The following is an example of the working principle of this utility model.

[0029] The first reactor 4 operates in a continuous mode, i.e., continuous inflow and continuous outflow. The hydraulic residence time of the first reactor 4 is controlled by the drainage rate of the fourth flow meter 14, the first flow meter 3, and the first overflow weir 4-1 (controlled by the control valve). The hydraulic residence time of the first reactor 4 is controlled by the fourth flow meter 14, the online nitrate nitrogen detector 13, the first water pump 2, the first flow meter 3, and the first COD... Cr Online detectors 1-2 control the COD in the first reactor 4. Cr / (Mass ratio). The dissolved oxygen in the first reactor 4 is controlled within a set range using the first dissolved oxygen detector 4-3, the bottom aeration system 4-2, and the blower. Suitable HRT and COD Cr / DO is used to inhibit the further denitrification of nitrite nitrogen into nitrogen gas, thereby increasing the accumulation rate of nitrite nitrogen.

[0030] Based on the average detection value of the online nitrate nitrogen analyzer 13, the flow rate values ​​of the first flow meter 3 and the fourth flow meter 14 are controlled to... Short-range denitrification The quality ratio is controlled at over 80%. When Short-range denitrification When the mass ratio is greater than 60%, it indicates that the reaction system of the first reactor 4 has been started. When the mass ratio reaches 80% or more, it indicates that the operation is normal.

[0031] In this embodiment, the first reactor 4 is a partial denitrification reactor. During partial denitrification, the organism provides electrons, and the bacteria... Restore to .

[0032] In this embodiment, the second reactor 8 is an anammox-coupled endogenous denitrification reactor. Anammox-coupled endogenous denitrification refers to the coupling of anammox and endogenous denitrification reactions within a single reactor. Microorganisms first adsorb organic matter into their cells, converting it into internal carbon sources (PHAs); then, anammox occurs, converting nitrite nitrogen and ammonia nitrogen into nitrogen gas and a small amount of nitrate nitrogen; finally, endogenous denitrification occurs, where microorganisms utilize the adsorbed internal carbon sources to denitrify the nitrate nitrogen produced by anammox into nitrogen gas.

Claims

1. A wastewater deep denitrification system, comprising a grit chamber effluent well (1), a first reactor (4), an intermediate tank (5), a second reactor (8), and a biochemical system (11), characterized in that: The sedimentation tank effluent well (1) is equipped with an online NH3-N detector (1-1) and a first COD detector. Cr Online monitoring device (1-2); The effluent well (1) of the sedimentation tank is connected to a first water pump (2), which is connected to the first reactor (4) through a pipeline with a first flow meter (3); The effluent well (1) of the sedimentation tank is connected to a second water pump (10), which is connected to the second reactor (8) through a pipeline with a second flow meter (9); The effluent well (1) of the sand tank is connected to the biochemical system (11) through a pipeline with a third flow meter (12), and the outlet of the biochemical system (11) is connected to the first reactor (4) through a pipeline with a fourth flow meter (14) and an online nitrate nitrogen monitoring device (13); The first reactor (4) is equipped with a first overflow weir (4-1), which is connected to the intermediate tank (5) through a pipeline with a control valve; The intermediate tank (5) is connected to a third water pump (6), which is connected to the second reactor (8) through a pipeline with a fifth flow meter (7); The intermediate tank (5) is equipped with Online testing instrument (5-1).

2. The wastewater deep denitrification system as described in claim 1, characterized in that: The first reactor (4) is a short-cut denitrification reactor; the first reactor (4) includes a tank body connected to a blower pipe (4-5); the tank body is equipped with a bottom aeration system (4-2), a first dissolved oxygen detector (4-3), and a fixed biological carrier packing material (4-4).

3. The wastewater deep denitrification system as described in claim 1, characterized in that: The second reactor (8) is an anaerobic ammonia oxidation coupled endogenous denitrification reactor; the second reactor (8) includes a tank body, which is equipped with a submersible agitator (8-2), a suspended biological carrier packing (8-3) and a second dissolved oxygen detector (8-4).

4. The wastewater deep denitrification system as described in claim 1, 2, or 3, characterized in that: The second reactor (8) is provided with a second overflow weir (8-1); the discharge end of the second overflow weir (8-1) is used to connect to the deep treatment system.

5. The wastewater deep denitrification system as described in claim 4, characterized in that: The second overflow weir (8-1) is equipped with a microbial carrier mesh.

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