A biological denitrification reactor with carbon source recovery function

Abstract

The present invention relates to the technical field of sewage treatment. The present invention discloses a biological denitrification reactor with a carbon source recovery function, comprising a carbon source recovery unit, a biochemical tank, and a sedimentation tank connected in sequence according to the flow direction of sewage. The biochemical tank has an anoxic zone for biochemical reaction and an aerobic zone for biochemical reaction. The reactor also comprises: a sludge return system and a sludge treatment system. The sludge return system returns the sludge in the sedimentation tank to the anoxic zone for biochemical reaction and the carbon source recovery unit. The pretreated sewage flows into the carbon source recovery unit, is mixed with the sludge in the carbon source recovery unit, and is hydrolyzed and fermented to produce a carbon source-rich mixed liquid that flows into the biochemical tank. The residual sludge in the carbon source recovery unit and the sedimentation tank is discharged to the sludge treatment system. The biological denitrification reactor with a carbon source recovery function disclosed by the present invention reduces the amount of external carbon source added, reduces the operating cost of the sewage treatment plant, reduces sludge production, reduces sludge treatment costs, reduces the generation of secondary pollutants, and improves the biological denitrification effect.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, in particular to a biological denitrification reactor with a carbon source recovery function. Background Art

[0002] As my country places increasing emphasis on environmental protection, requirements for industrial wastewater effluent quality are becoming increasingly stringent, particularly regarding nitrogen content. Insufficient carbon sources in the influent are a common problem facing many industrial wastewater treatment plants. This inadequate carbon source directly impacts the plant's denitrification efforts, causing effluent nitrogen content to exceed standards and fail to meet discharge requirements. This is because wastewater denitrification involves both nitrification and denitrification, which require a carbon source. In actual operation, the C / N ratio should be greater than 3. To address this issue, wastewater treatment plants commonly add carbon sources (such as glucose, sodium acetate, and acetic acid) to the water to improve nitrogen removal. However, this approach increases wastewater treatment plant operating costs and significantly increases sludge production, which contains large amounts of undecomposed organic matter. Sewage treatment plants typically dewater this sludge and then landfill or incinerate it. This not only incurs additional treatment costs but also creates secondary pollution. Furthermore, the large amount of undecomposed organic matter in the sludge is not properly utilized, resulting in a waste of resources. This long-term operation method is neither economical nor rational.

[0003] In fact, the sludge produced daily by sewage treatment plants can itself, through special treatment, become a stable and reliable source of carbon. Currently, attention has been focused both domestically and internationally on utilizing the products of biochemical sludge hydrolysis and fermentation reactions as a supplemental carbon source, with some projects already operating. However, primary sludge is often used as the hydrolysis feedstock. For industrial wastewater treatment plants, primary sludge fluctuates significantly due to water quality and is insufficient in quantity. Furthermore, primary sludge lacks a sufficient number of biologically active, hydrolyzable, and fermentable mixed bacterial communities, resulting in a relatively low conversion rate of available carbon sources. Biochemical activated sludge, on the other hand, is much more abundant than primary sludge, and contains a rich variety of aerobic, anoxic, and facultative bacteria, which can directly provide a mixed bacterial community microbial inoculum for the sludge hydrolysis process.

[0004] In view of this, considering recycling activated sludge as a supplementary carbon source, reducing the amount of external carbon source in denitrification treatment water, and enhancing the denitrification effect, this invention is specially proposed. Summary of the Invention

[0005] To achieve the above-mentioned purpose, the present invention discloses a biological denitrification reactor with a carbon source recovery function, comprising a carbon source recovery unit, a biochemical tank and a sedimentation tank connected in sequence according to the flow direction of sewage, the biochemical tank having an anoxic zone for biochemical reaction and an aerobic zone for biochemical reaction, and further comprising: a sludge return system and a sludge treatment system, the sludge return system returns the sludge in the sedimentation tank to the anoxic zone for biochemical reaction and the carbon source recovery unit, the pretreated sewage flows into the carbon source recovery unit, is mixed with the sludge in the carbon source recovery unit, and is hydrolyzed and fermented to generate a carbon source-rich mixed liquid, which flows into the biochemical tank, and the remaining sludge in the carbon source recovery unit and the sedimentation tank is discharged to the sludge treatment system.

[0006] Preferably, the carbon source recovery unit comprises:

[0007] The hydrolysis tank and the biochemical tank are built adjacent to each other and separated by a partition wall. The mixed liquid rich in carbon source overflows from the partition wall into the anoxic area of ​​the biochemical reaction;

[0008] Submersible propulsion agitator, the submersible propulsion agitator is installed in the hydrolysis tank and evenly distributed along the long axis direction of the hydrolysis tank;

[0009] Suspended filler device: The suspended filler device is installed in the hydrolysis tank.

[0010] Preferably, the hydrolysis tank adopts a rectangular or circular tank body, the bottom of the hydrolysis tank adopts a sloped structure with a slope of ≥30°, and is provided with a mud pit to facilitate the sedimentation of the remaining sludge after mineralization and its centralized discharge to the sludge treatment system.

[0011] Preferably, the biochemical reaction anoxic zone adopts an annular pool body to be arranged around the biochemical reaction aerobic zone, a submersible flow stirrer is provided in the biochemical reaction anoxic zone, an aeration device is provided in the biochemical reaction aerobic zone, the biochemical reaction aerobic zone and the biochemical reaction anoxic zone are separated by a partition wall, and a nitrification liquid reflux device is provided to facilitate the reflux of the nitrification liquid in the biochemical reaction aerobic zone to the biochemical reaction anoxic zone.

[0012] Preferably, the sedimentation tank adopts any one of a side-in and side-out rectangular sedimentation tank, a horizontal flow sedimentation tank or a radial flow sedimentation tank.

[0013] Preferably, the suspended filler device uses polyethylene or polyurethane porous suspended fillers with high specific surface area, and the filler filling rate is 20-40% of the tank volume.

[0014] Preferably, the suspended filler device comprises:

[0015] A central fixed cylinder is fixed at the center of the hydrolysis tank;

[0016] The central suspension box is fixedly mounted on the inner wall of the central fixed cylinder, and a plurality of external openings are opened in the circumferential direction of the side end of the central suspension box;

[0017] An annular suspension box is sleeved on the outer wall of the central fixed cylinder. Suspension fillers are placed in both the central suspension box and the annular suspension box. The inner ring end of the annular suspension box is circumferentially provided with multiple inner openings, which are adapted to the outer openings.

[0018] Communication ports, the number of which is equal to the inner openings, are circumferentially arranged on the central fixed cylinder and are transitionally connected to the outer opening and the inner opening;

[0019] The annular grid plate divides the annular suspension box into two independent chambers, the upper and lower chambers, and the annular grid plate is fixedly installed on the central fixed cylinder.

[0020] Preferably, the device further comprises four lifting assemblies circumferentially mounted on the outer wall of the central fixed cylinder near the top, the lifting assemblies being connected to the annular suspension box. When the lifting assemblies drive the annular suspension box to rise and fall, the inner opening and the outer opening are dislocated, thereby adjusting the flow area of ​​the connecting port between the outer opening and the inner opening. The lifting assemblies comprise:

[0021] Side mounting plates, the side mounting plates are fixedly mounted on the outer wall of the central fixed cylinder;

[0022] The upper mounting seat and the lower mounting seat are installed on the side mounting plate, and the central rotating shaft is rotatably installed on the upper mounting seat and the lower mounting seat;

[0023] The upper sleeve shaft is mounted on the central rotating shaft through the cooperation of the ratchet pawl, and an annular reciprocating groove 1 is opened on the upper sleeve shaft;

[0024] The upper sleeve is sleeved on the upper sleeve shaft and slides along the annular reciprocating groove;

[0025] The flap is rotatably mounted on the upper mounting seat via a mounting shaft, and the flip rod is connected between the upper sleeve and the flap;

[0026] A vertical pull rod, the top end of which is slidably mounted on the flap, and the bottom end of which is connected to the annular suspension box.

[0027] Preferably, the lifting assembly further comprises:

[0028] The lower sleeve is mounted on the central shaft, the lower end of the lower sleeve is provided with a main gear, the main gear is mounted on the central shaft, the lower end of the main gear is provided with a locking groove, and the central shaft is provided with a locking block adapted to the locking groove;

[0029] Return springs, symmetrically distributed return springs connected between the lower sleeve and the lower mounting seat;

[0030] Push rods, symmetrically distributed push rods are installed on the upper mounting seat and connected to the upper sleeve. The push rods are used to support the lower sleeve to perform sinking movement;

[0031] The side shaft is rotatably mounted on the lower mounting seat through the side mounting frame, and a secondary gear adapted to the main gear is mounted near the bottom end of the side shaft;

[0032] The lifting block is sleeved on the side rotating shaft, and an annular reciprocating groove 2 is opened on the side rotating shaft. The lifting block slides along the annular reciprocating groove 2. The transmission rack is installed on the lifting block, and the transmission gear of the transmission rack is installed on the mounting shaft. The spray assembly is installed on the flap and is connected to the mounting shaft.

[0033] Preferably, the spray assembly includes: two groups of spray pipes symmetrically installed at the bottom end of the flap, spray heads are installed at equal intervals on each group of spray pipes, and a secondary sprocket is installed on each group of spray pipes. A avoidance opening is opened on the flap, and the installation shaft extends into the avoidance opening. The main sprocket is located in the avoidance opening and is installed on the installation shaft. The chain belt drive is connected between the main sprocket and the secondary sprocket. The installation shaft can be bent to facilitate the upward flipping of the flap. When the flap is in a horizontal state, the installation shaft drives the main sprocket to rotate in the avoidance opening. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] Figure 1 It is a schematic diagram of the process of the present invention;

[0036] Figure 2 This is a schematic diagram of the carbon source recovery unit structure of the present invention. Figure 1 ;

[0037] Figure 3 for Figure 2 Enlarged view of the middle label A;

[0038] Figure 4 This is a schematic diagram of the carbon source recovery unit structure of the present invention. Figure 2 (When the annular suspension box is lifted);

[0039] Figure 5 for Figure 4 The enlarged schematic diagram of the middle label B;

[0040] Figure 6 Schematic diagram of the lifting assembly structure of the present invention Figure 1 ;

[0041] Figure 7 This is a schematic structural diagram of the spray assembly of the flap of the present invention;

[0042] Figure 8 This is a schematic diagram of the lifting block of the present invention being fitted on the side shaft;

[0043] Figure 9 Schematic diagram of the lifting assembly structure of the present invention Figure 2 (When the annular suspension box is raised).

[0044] Figure: 1. Carbon source recovery unit; 2. Biochemical tank; 3. Sedimentation tank; 4. Sludge return system; 5. Sludge treatment system; 6. Lifting assembly; 7. Spray assembly; 11. Hydrolysis tank; 12. Submersible flow mixer; 13. Suspended filler device; 21. Anoxic zone for biochemical reaction; 22. Aerobic zone for biochemical reaction; 31. Central fixed cylinder; 32. Central suspension box; 33. Annular suspension box; 34. External opening; 35. Internal opening; 36. Connecting port; 37. Annular grid plate; 61. Side mounting plate; 62. Upper mounting seat; 63. Lower mounting seat; 64. Middle Central rotating shaft; 65. Upper sleeve shaft; 66. Annular reciprocating groove 1; 67. Upper sleeve; 68. Flap; 69. Mounting shaft; 70. Vertical pull rod; 71. Upper sliding sleeve; 72. Main gear; 73. Locking block; 74. Return spring; 75. Ejector rod; 76. Side rotating shaft; 77. Secondary gear; 78. Lifting block; 79. Transmission rack; 80. Transmission gear; 81. Spray pipe; 82. Spray head; 83. Secondary sprocket; 84. Avoidance port; 85. Main sprocket; 86. Chain belt; 87. Power element; 88. Ear; 89. Limiting slide; 90. Flip rod. DETAILED DESCRIPTION

[0045] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0046] Example

[0047] The present invention will be further described below with reference to the accompanying drawings.

[0048] like Figure 1As shown, the present embodiment provides a biological denitrification reactor with a carbon source recovery function, comprising a carbon source recovery unit 1, a biochemical tank 2 and a sedimentation tank 3 connected in sequence according to the flow direction of sewage. The biochemical tank 2 has a biochemical reaction anoxic zone 21 and a biochemical reaction aerobic zone 22, and also includes: a sludge return system 4 and a sludge treatment system 5. The sludge return system 4 returns the sludge in the sedimentation tank 3 to the biochemical reaction anoxic zone 21 and the carbon source recovery unit 1. The pretreated sewage flows into the carbon source recovery unit 1, is mixed with the sludge in the carbon source recovery unit 1, and is hydrolyzed and fermented to produce a carbon source-rich mixed liquid and flows into the biochemical tank 2. The remaining sludge in the carbon source recovery unit 1 and the sedimentation tank 3 is discharged to the sludge treatment system 5.

[0049] The working principle and beneficial effects of the above technical solution are:

[0050] The present invention provides a biological denitrification reactor with carbon source recovery. It is a composite reactor comprising a carbon source recovery unit 1, a biochemical tank 2, and a sedimentation tank 3. Pretreated sewage from a sewage treatment plant is fed into the carbon source recovery unit 1 and mixed with return sludge. The carbon source recovery unit 1 hydrolyzes and ferments the biologically activated sludge to produce a carbon source-rich mixed liquor and residual sludge. The biochemical tank 2 biochemically treats the incoming water, removing ammonia nitrogen and total nitrogen from the water to produce a sludge mixed liquor. The biochemical tank includes an anoxic biochemical reaction zone 21 and an aerobic biochemical reaction zone 22. The sedimentation tank 3 screens and separates the sludge mixed liquor to produce return sludge, residual sludge, and supernatant. A sludge return system 4 returns the return sludge from the sedimentation tank 3 to the anoxic biochemical reaction zone 21 and the carbon source recovery unit 1. To prevent odor pollution, the carbon source recovery unit 1 and the anoxic biochemical reaction zone 21 are sealed and equipped with ventilation ducts and deodorization equipment.

[0051] The biological denitrification reactor with carbon source recovery function disclosed in the present invention has the following advantages:

[0052] Advantage 1: The carbon-rich mixed liquor flows into the biochemical pool 2, replenishing the carbon source required for the biochemical process, thereby solving the problem of large external carbon source dosage and high sludge production in the existing process. This in turn reduces the daily operating costs of the sewage treatment plant and the sludge disposal costs.

[0053] Advantage 2: Using activated sludge instead of primary sludge for hydrolysis increases the organic matter content in the hydrolyzate, and the components of the biochemical hydrolysis carbon source recovery reaction products are more conducive to the absorption of denitrifying bacteria, thereby improving the denitrification capacity.

[0054] Advantage 3: Strong applicability, suitable not only for new sewage treatment plants but also for upgrading existing ones. Suitable for denitrification of industrial wastewater with low C / N ratios. The sludge carbon source recovery device can be used to supplement the insufficient carbon source in the influent, making it suitable for both new sewage treatment plants and wastewater upgrading projects.

[0055] In this embodiment, the carbon source recovery unit 1 includes:

[0056] The hydrolysis tank 11 is built adjacent to the biochemical tank 2 and separated by a partition wall. The mixed liquid rich in carbon source overflows from the partition wall into the biochemical reaction anoxic zone 21;

[0057] Submersible flow agitator 12, the submersible flow agitator 12 is installed in the hydrolysis tank 11 and is evenly distributed along the long axis direction of the hydrolysis tank 11;

[0058] The suspended filler device 13 is installed in the hydrolysis tank 11 .

[0059] The working principle and beneficial effects of the above technical solution are:

[0060] The sludge return system 4 returns the return sludge in the sedimentation tank 3 to the hydrolysis tank 11. The sewage from the sewage treatment plant enters the hydrolysis tank 11 after pretreatment. The submersible flow mixer 12 is evenly distributed along the long axis of the tank body. The submersible flow mixer 12 controls the stirring speed at 30-60rpm to avoid excessive shearing and destroying the activity of microorganisms. The water flow mixer 12 achieves uniform distribution of sludge through low-speed flow, ensures sufficient contact between sludge and filler, prevents sludge deposition, and improves the sludge hydrolysis effect; and a suspended filler device 13 is provided to improve the biochemical effect.

[0061] In this embodiment, the hydrolysis tank 11 adopts a rectangular or circular tank body, and the bottom of the hydrolysis tank 11 adopts a sloped structure with a slope ≥30°, and is provided with a mud pit. A mud pump is used to discharge mud regularly to facilitate the sedimentation of the remaining sludge after mineralization and its centralized discharge to the sludge treatment system 5.

[0062] The working principle and beneficial effects of the above technical solution are:

[0063] The bottom of the hydrolysis tank 11 is sloped to improve sludge removal efficiency, and the sludge discharge pipe adopts a multi-point sludge discharge method. The hydrolysis tank 11 is also equipped with online instruments such as a sludge level meter, a pH meter, and a temperature sensor to monitor and control the sludge reaction process. The sludge level meter is used to monitor the thickness of the sludge layer in real time and control the frequency of sludge discharge; the pH meter is used to maintain the pH of the hydrolysis tank between 6.5 and 8.0 (the optimal hydrolysis and acidification range); and the temperature sensor is used to ensure that the hydrolysis temperature is controlled at 25-35°C (medium-temperature hydrolysis conditions).

[0064] In this embodiment, the biochemical reaction anoxic zone 21 adopts an annular pool body and is arranged around the biochemical reaction aerobic zone 22. A submersible flow mixer is provided in the biochemical reaction anoxic zone 21, and an aeration device is provided in the biochemical reaction aerobic zone 22. The biochemical reaction aerobic zone 22 is separated from the biochemical reaction anoxic zone 21 by a partition wall, and a nitrification liquid reflux device 23 is provided to facilitate the reflux of the nitrification liquid in the biochemical reaction aerobic zone 22 to the biochemical reaction anoxic zone 21.

[0065] The working principle and beneficial effects of the above technical solution are:

[0066] Biochemical pool 2 utilizes A / O denitrification technology. The anoxic biochemical reaction zone 21 and the aerobic biochemical reaction zone 22 are separated by a single wall. The nitrification liquid reflux device 23 facilitates the reflux of the nitrification liquid, reducing the power of the nitrification liquid reflux pump and achieving greater energy savings. Biochemical pool 2 can also utilize other biochemical processes, such as SBR, oxidation ditch, and biofilm processes. This process primarily removes ammonia nitrogen and total nitrogen from the water.

[0067] In this embodiment, the sedimentation tank 3 adopts any one of a rectangular sedimentation tank with side inlet and side outlet, a horizontal flow sedimentation tank or a radial flow sedimentation tank.

[0068] In this embodiment, the suspended filler device 13 uses polyethylene or polyurethane porous suspended fillers with high specific surface area, and the filler filling rate is 20-40% of the tank volume.

[0069] like Figures 2 to 9 As shown, in this embodiment, the suspended filler device 13 includes:

[0070] The central fixed cylinder 31 is fixed at the center of the hydrolysis tank 11;

[0071] The central suspension box 32 is fixedly mounted on the inner wall of the central fixed cylinder 31 , and a plurality of external openings 34 are circumferentially formed on the side end of the central suspension box 32 ;

[0072] The annular suspension box 33 is sleeved on the outer wall of the central fixed cylinder 31. Suspended fillers are placed in both the central suspension box 32 and the annular suspension box 33. The inner ring end of the annular suspension box 33 is circumferentially provided with multiple inner openings 35, which are adapted to the outer openings 34.

[0073] Communication openings 36 , the number of which is equal to the number of the inner openings 35 , are circumferentially provided on the central fixed cylinder 31 and transitionally connect the outer opening 34 and the inner opening 35 ;

[0074] The annular grid plate 37 divides the annular suspension box 33 into two independent chambers, the upper and lower chambers. The annular grid plate 37 is fixedly mounted on the central fixed cylinder 31 .

[0075] The working principle and beneficial effects of the above technical solution are:

[0076] An annular aeration pipe is provided in the hydrolysis tank 11 and at the bottom end of the central fixed cylinder 31. The aperture of the annular aeration pipe is 1 mm and the pore density is 50 / m 2, aeration volume 0.1-0.5VVM. The rising gas drives the pretreated sewage and return sludge upward through the central fixed cylinder 31, and the hydrolysis rate is increased under the action of the suspended filler in the central suspension box 32. Then the sewage and return sludge go downward along the outer opening 34, the connecting port 36 and the inner opening 35, and pass through the annular suspension box 33 to form a stable cycle. The annular suspension box 33 can be lifted to control the volume of the space inside the annular suspension box 33 and below the annular grid plate 37, thereby realizing a change in the bulk density of the suspended filler. To ensure the fluidity of the suspended filler. The suspended filler in the annular suspension box 33 and the suspended filler in the central suspension box 32 are arranged to communicate with each other through the inner opening 35, the connecting port 36 and the outer opening 34.

[0077] In this embodiment, four lifting assemblies 6 are circumferentially mounted on the outer wall of the central fixed cylinder 31 near the top. The lifting assemblies 6 are connected to the annular suspension box 33. When the lifting assemblies 6 drive the annular suspension box 33 to rise and fall, the inner opening 35 and the outer opening 34 are misaligned, thereby adjusting the flow area of ​​the communication port 36 between the outer opening 34 and the inner opening 35. The lifting assemblies 6 include:

[0078] A side mounting plate 61 is fixedly mounted on the outer wall of the central fixed cylinder 31;

[0079] The upper mounting seat 62 and the lower mounting seat 63 are mounted on the side mounting plate 61. The central rotating shaft 64 is rotatably mounted on the upper mounting seat 62 and the lower mounting seat 63. The power element 87 connected to the central rotating shaft 64 is mounted on the lower mounting seat 63.

[0080] The upper sleeve shaft 65 is mounted on the central rotating shaft 64 through the cooperation of the ratchet pawl, and an annular reciprocating groove 66 is opened on the upper sleeve shaft 65;

[0081] The upper sleeve 67 is sleeved on the upper sleeve shaft 65 and slides along the annular reciprocating groove 1 66;

[0082] The flap 68 is rotatably mounted on the upper mounting seat 62 via the mounting shaft 69 , and the flip rod 90 is connected between the upper sleeve 67 and the flap 68 ;

[0083] The vertical pull rod 70 has its top end slidably mounted on the flap 68 , and its bottom end is connected to the annular suspension box 33 .

[0084] The working principle and beneficial effects of the above technical solution are:

[0085] The power element 87 rotates forward and drives the central rotating shaft 64 connected to its output end to rotate on the upper mounting seat 62 and the lower mounting seat 63. At this time, the ratchet and the pawl cooperate, and the central rotating shaft 64 drives the upper sleeve 65 to rotate. Under the cooperation of the annular reciprocating groove 1 66 and the upper sleeve 67, the upper sleeve 67 falls back, and then drives the flip plate 68 to flip to a horizontal state through the flip rod 90. The vertical pull rod 70 that cooperates with the flip plate 68 drives the annular suspension box 33 to fall back. The annular suspension box 33 is located below the annular grid plate 37. The volume of the space on the side increases, and the flow area of ​​the connecting port 36 connecting between the outer opening 34 and the inner opening 35 increases. After the flap 68 flips to a horizontal state, the upper sleeve 67 falls back to the lowest position. At this time, the volume of the space below the annular grid plate 37 in the annular suspension box 33 is the largest, the flow space of the suspended filler is the largest, and the flow area of ​​the connecting port 36 connecting between the outer opening 34 and the inner opening 35 is the largest, which is more convenient for the mutual flow of the suspended filler in the annular suspension box 33 and the suspended filler in the central suspension box 32.

[0086] Specifically, a limiting sliding groove 89 is provided on the flap 68 , and the top end of the vertical pull rod 70 is slidably connected in the limiting sliding groove 89 .

[0087] In this embodiment, the lifting assembly 6 further includes:

[0088] The lower sleeve 71 is sleeved on the central shaft 64. The bottom end of the lower sleeve 71 is rotatably mounted with a main gear 72. The main gear 72 is sleeved on the central shaft 64. The bottom end of the main gear 72 is provided with a locking groove. The central shaft 64 is provided with a locking block 73 adapted to the locking groove.

[0089] Return springs 74, two sets of return springs 74 are symmetrically distributed around the central shaft 64, and the return springs 74 are connected between the lower sleeve 71 and the lower mounting seat 63;

[0090] The two sets of push rods 75 are symmetrically distributed around the central rotation axis 64. The push rods 75 are installed on the upper mounting seat 62 and connected to the upper sleeve 67. The push rods 75 are used to support the lower sleeve 71 to make the sinking movement. The top of the lower sleeve 71 is symmetrically equipped with two ears 88 to facilitate the support of the push rods 75 and the connection of the return spring 74.

[0091] The side shaft 76 is rotatably mounted on the lower mounting base 63 via a side mounting frame. A secondary gear 77 adapted to the main gear 72 is mounted near the bottom end of the side shaft 76.

[0092] The lifting block 78 is sleeved on the side rotating shaft 76. The side rotating shaft 76 is provided with an annular reciprocating groove 2. The lifting block 78 slides along the annular reciprocating groove 2. The transmission rack 79 is installed on the lifting block 78. The transmission gear 80 of the transmission rack 79 is installed on the mounting shaft 69. The spray assembly 7 is installed on the flap 68 and is connected to the mounting shaft 69 in transmission.

[0093] The working principle and beneficial effects of the above technical solution are:

[0094] When the power element 87 rotates forward, the upper sleeve 67 returns to its lowest position, and the flap 68 flips to a horizontal position. At this point, the volume of the space below the annular grid plate 37 within the annular suspension box 33 is maximized, allowing the flow of the suspended filler to its maximum, and the flow area of ​​the communication port 36 between the outer opening 34 and the inner opening 35 to its maximum. The upper sleeve 67 presses the ear portion 88 via the push rod 75, thereby driving the lower sleeve 71 in the direction of contraction of the return spring 74. The lower sleeve 71 drives the main gear 72 downward until it engages with the secondary gear 77, and the locking groove engages the locking block 73.

[0095] Then the power element 87 rotates in the opposite direction and drives the central rotating shaft 64 connected to its output end to rotate. At this time, the ratchet and the pawl do not cooperate, and the central rotating shaft 64 cannot drive the upper sleeve shaft 65 to rotate in the opposite direction. However, due to the cooperation between the locking groove and the locking block 73, when the central rotating shaft 64 rotates in the opposite direction, it drives the main gear 72 and the sub-gear 77 meshing with the main gear 72 to rotate. The sub-gear 77 drives the side rotating shaft 76 to rotate on the side mounting frame. Under the cooperation of the annular reciprocating groove 2 on the side rotating shaft 76 and the lifting block 78, the transmission gear 76 is driven. The gear rack 79 performs a reciprocating lifting motion, thereby driving the transmission gear 80 meshing with the transmission rack 79 and the mounting shaft 69 connected to the transmission gear 80 to perform periodic forward and reverse rotations, thereby driving the spray assembly 7 connected to the mounting shaft 69 and mounted at the bottom end of the flap 68 to rotate. The spray assembly 7 sprays droplets, thereby improving the fluidity of the suspended filler located at the top of the annular suspension box 33 at the connection port 36, thereby improving the fluidity of the suspended filler in the annular suspension box 33 and the suspended filler in the central suspension box 32. Therefore, when the volume of the space below the annular grid plate 37 in the annular suspension box 33 is the largest, the fluidity of the suspended filler in the annular suspension box 33 and the suspended filler in the central suspension box 32 is also correspondingly improved.

[0096] When the annular suspension box 33 needs to be re-suspended to reduce the volume of the space below the annular grid plate 37 in the annular suspension box 33, the power element 87 rotates forward. At this time, the ratchet and the pawl cooperate, and the central shaft 64 drives the upper sleeve shaft 65 to rotate. With the cooperation of the annular reciprocating groove 1 66 and the upper sleeve 67, the upper sleeve 67 is lifted up, and then the flip plate 68 in the horizontal state is flipped through the flip rod 90. The horizontal flip plate 68 drives the annular suspension box 33 to be lifted up through the vertical pull rod 70.

[0097] In this embodiment, the spray assembly 7 includes: two groups of spray pipes 81 symmetrically installed at the bottom end of the flap 68, each group of spray pipes 81 is evenly spaced with a spray head 82, each group of spray pipes 81 is installed with a secondary sprocket 83, a avoidance opening 84 is opened on the flap 68, the installation shaft 69 extends into the avoidance opening 84, the main sprocket 85 is located in the avoidance opening 84 and is installed on the installation shaft 69, the chain belt 86 is connected between the main sprocket 85 and the secondary sprocket 83, the installation shaft 69 can be bent to facilitate the upward flipping of the flap 68, and when the flap 68 is in a horizontal state, the installation shaft 69 drives the main sprocket 85 to rotate in the avoidance opening 84.

[0098] The working principle and beneficial effects of the above technical solution are:

[0099] When the flap 68 is flipped to a horizontal state, the mounting shaft 69 is in a straight state, so that the transmission rack 79 performs a reciprocating lifting motion, thereby driving the transmission gear 80 meshing with the transmission rack 79 and the mounting shaft 69 connected to the transmission gear 80 to perform periodic forward and reverse rotations, thereby driving the main sprocket 85 connected to the mounting shaft 69 to rotate in the avoidance opening 84. The main sprocket 85 drives the secondary sprocket 83 and the spray pipe 81 connected to the secondary sprocket 83 to rotate through the cooperation of the chain belt 86. After the two groups of spray pipes 81 rotate periodically, the droplets are sprayed out from the spray head 82 over a large area, thereby increasing the spraying area to maximize the fluidity of the suspended filler located at the top of the annular suspension box 33 at the connecting port 36.

[0100] Specifically, the two groups of spray pipes 81 are symmetrically distributed with the limiting sliding groove 89 as the center.

[0101] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A biological denitrification reactor with carbon source recovery function, characterized in that: The system comprises a carbon source recovery unit (1), a biochemical tank (2) and a sedimentation tank (3) connected in sequence according to the flow direction of sewage. The biochemical tank (2) has a biochemical reaction anoxic zone (21) and a biochemical reaction aerobic zone (22). The system also comprises: a sludge return system (4) and a sludge treatment system (5). The sludge return system (4) returns the sludge in the sedimentation tank (3) to the biochemical reaction anoxic zone (21) and the carbon source recovery unit (1). The pretreated sewage flows into the carbon source recovery unit (1), is mixed with the sludge in the carbon source recovery unit (1), and is hydrolyzed and fermented to produce a mixed liquid rich in carbon source and flows into the biochemical tank (2). The remaining sludge in the carbon source recovery unit (1) and the sedimentation tank (3) is discharged to the sludge treatment system (5). The carbon source recovery unit (1) includes: The hydrolysis tank (11) is built adjacent to the biochemical tank (2) and separated by a partition wall. The mixed liquid rich in carbon source overflows from the partition wall into the biochemical reaction anoxic zone (21); A submersible flow-pushing agitator (12), the submersible flow-pushing agitator (12) is installed in the hydrolysis tank (11) and is evenly distributed along the long axis direction of the hydrolysis tank (11); A suspended filler device (13), the suspended filler device (13) is installed in the hydrolysis tank (11); The suspended filler device (13) comprises: a central fixed cylinder (31) fixedly located at the center position in the hydrolysis tank (11); a central suspension box (32) fixedly mounted on the inner wall of the central fixed cylinder (31), and a plurality of outer openings (34) are circumferentially opened on the side end of the central suspension box (32); an annular suspension box (33) is sleeved on the outer wall of the central fixed cylinder (31), and suspended fillers are placed in both the central suspension box (32) and the annular suspension box (33), and a plurality of inner openings (35) are circumferentially opened on the inner ring end of the annular suspension box (33), and the inner openings (35) are adapted to the outer openings (34); a number of communication ports (36) equal to the number of the inner openings (35) are circumferentially opened on the central fixed cylinder (31), and transitionally connected to the outer openings (34) and the inner openings (35); an annular grid plate (37) divides the annular suspension box (33) into two independent chambers, upper and lower, and the annular grid plate (37) is fixedly mounted on the central fixed cylinder (31); The invention also includes four lifting assemblies (6) circumferentially mounted on the outer wall of the central fixed cylinder (31) near the top position, and the lifting assemblies (6) include: a side mounting plate (61) fixedly mounted on the outer wall of the central fixed cylinder (31); an upper mounting seat (62) and a lower mounting seat (63) mounted on the side mounting plate (61); a central rotating shaft (64) rotatably mounted on the upper mounting seat (62) and the lower mounting seat (63); an upper sleeve shaft (65) mounted on the central rotating shaft (64) through the cooperation of a ratchet pawl An annular reciprocating groove (66) is provided on the upper sleeve shaft (65); an upper sleeve (67) is sleeved on the upper sleeve shaft (65) and slides along the annular reciprocating groove (66); a flap (68) is rotatably mounted on the upper mounting seat (62) through a mounting shaft (69), and a flip rod (90) is connected between the upper sleeve (67) and the flap (68); the top end of the vertical pull rod (70) is slidably mounted on the flap (68), and the bottom end of the vertical pull rod (70) is connected to the annular suspension box (33).

2. The biological denitrification reactor with carbon source recovery function according to claim 1, characterized in that: The hydrolysis tank (11) adopts a rectangular or circular tank body, and the bottom of the hydrolysis tank (11) adopts a sloped structure with a slope of ≥30°, and is provided with a mud pit to facilitate the sedimentation of the remaining sludge after mineralization and to discharge it to the sludge treatment system (5).

3. The biological denitrification reactor with carbon source recovery function according to claim 1, characterized in that: The biochemical reaction anoxic zone (21) adopts an annular pool body to be arranged around the biochemical reaction aerobic zone (22). A submersible flow mixer is provided in the biochemical reaction anoxic zone (21). An aeration device is provided in the biochemical reaction aerobic zone (22). The biochemical reaction aerobic zone (22) and the biochemical reaction anoxic zone (21) are separated by a partition wall, and a nitrification liquid reflux device (23) is provided to facilitate the reflux of the nitrification liquid in the biochemical reaction aerobic zone (22) to the biochemical reaction anoxic zone (21).

4. The biological denitrification reactor with carbon source recovery function according to claim 1, characterized in that: The sedimentation tank (3) adopts any one of a rectangular sedimentation tank with side inlet and side outlet, a horizontal flow sedimentation tank or a radial flow sedimentation tank.

5. The biological denitrification reactor with carbon source recovery function according to claim 1, characterized in that: The suspended filler device (13) uses polyethylene or polyurethane porous suspended filler with a high specific surface area, and the filler filling rate is 20-40% of the pool volume.

6. The biological denitrification reactor with carbon source recovery function according to claim 1, characterized in that: The lifting assembly (6) further comprises: a lower sleeve (71) sleeved on the central shaft (64), a main gear (72) being mounted on the bottom end of the lower sleeve (71), the main gear (72) being sleeved on the central shaft (64), a locking groove being provided at the bottom end of the main gear (72), and a locking block (73) adapted to the locking groove being mounted on the central shaft (64); symmetrically distributed return springs (74) being connected between the lower sleeve (71) and the lower mounting seat (63); symmetrically distributed ejector rods (75) being passed through the upper mounting seat (62) and connected to the upper sleeve (67), the ejector rods (75) being used to press against the lower sleeve (71) to make the lower sleeve (71) Sedimentation movement; the side rotating shaft (76) is rotatably mounted on the lower mounting seat (63) through the side mounting frame, and a sub-gear (77) adapted to the main gear (72) is mounted near the bottom of the side rotating shaft (76); the lifting block (78) is sleeved on the side rotating shaft (76), and an annular reciprocating groove II is opened on the side rotating shaft (76), and the lifting block (78) slides along the annular reciprocating groove II, and the transmission rack (79) is mounted on the lifting block (78), and the transmission gear (80) of the transmission rack (79) is mounted on the mounting shaft (69), and the spray assembly (7) is mounted on the flap (68) and is connected to the mounting shaft (69) in a transmission manner.

7. The biological denitrification reactor with carbon source recovery function according to claim 6, characterized in that: The spray assembly (7) includes: two groups of spray pipes (81) symmetrically installed at the bottom end of the flap (68), each group of spray pipes (81) is evenly spaced and equipped with a spray head (82), each group of spray pipes (81) is equipped with a secondary sprocket (83), a bypass opening (84) is provided on the flap (68), a mounting shaft (69) extends into the bypass opening (84), a main sprocket (85) is located in the bypass opening (84) and is mounted on the mounting shaft (69), a chain belt (86) is connected between the main sprocket (85) and the secondary sprocket (83), and the mounting shaft (69) can be bent to facilitate the flap (68) to flip upward, and when the flap (68) is in a horizontal state, the mounting shaft (69) drives the main sprocket (85) to rotate in the bypass opening (84).

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