Biological denitrification reactor with carbon source recovery function

Abstract

The invention relates to the technical field of sewage treatment, and discloses a biological denitrification reactor with a carbon source recovery function, the biological denitrification reactor comprises a carbon source recovery unit, a biochemical pool and a sedimentation pool which are sequentially connected according to the flow direction of sewage, the biochemical pool is provided with a biochemical reaction anoxic zone and a biochemical reaction aerobic zone, and the biological denitrification reactor also comprises a sludge reflux system and a sludge treatment system, the sludge return system returns sludge in the sedimentation tank to the biochemical reaction anoxic zone and the carbon source recovery unit, the pretreated sewage flows into the carbon source recovery unit and is mixed with sludge in the carbon source recovery unit for hydrolysis fermentation, and a mixed solution rich in a carbon source is generated and flows into the biochemical tank; and residual sludge in the carbon source recovery unit and the sedimentation tank is discharged to a sludge treatment system. According to the biological denitrification reactor with the carbon source recovery function disclosed by the invention, the addition amount of an external carbon source is reduced, the operation cost of a sewage plant is reduced, the sludge yield is reduced, the sludge treatment cost is reduced, secondary pollutants are reduced, and the biological denitrification effect is improved.

Description

Technical Field

[0001] The 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 attaches more and more importance to environmental protection, the requirements for industrial wastewater effluent water quality indicators are becoming more and more stringent, especially the requirements for N content in water. Insufficient carbon source in influent is a common problem in many industrial sewage treatment plants. Insufficient carbon source will directly affect the denitrification effect of sewage treatment plants, causing the effluent N content to exceed the standard and unable to meet the discharge requirements. This is because the sewage denitrification process needs to undergo nitrification and denitrification, and a certain carbon source is required in the denitrification process. In actual engineering operation, C / N should be greater than 3. In order to solve this problem, the current common method for sewage treatment plants is to add carbon sources (such as commonly used glucose, sodium acetate, acetic acid, etc.) to water to improve the nitrogen removal effect. However, this practice will increase the operating costs of sewage treatment plants, and at the same time, the sludge generated will increase significantly, and the sludge contains a large amount of undecomposed organic matter. The usual practice for sewage treatment plants to produce this kind of sludge is to landfill or incinerate it after dehydration, which will not only incur additional treatment costs, but also cause secondary pollution problems. At the same time, a large amount of undecomposed organic matter in the sludge is not reasonably utilized, resulting in a waste of resources. This long-term operation mode is neither economical nor reasonable.

[0003] In fact, the sludge produced every day in sewage treatment plants is a stable and reliable carbon source after special treatment. At present, domestic and foreign researchers have begun to pay attention to the use of biochemical sludge hydrolysis and fermentation reaction products as a supplementary carbon source, and there are some engineering operation examples, but primary sludge is mostly used as the hydrolysis raw material. For industrial sewage treatment plants, primary sludge fluctuates greatly due to the influence of water quality and is insufficient in quantity. At the same time, there is a lack of sufficient number of biologically active, hydrolyzable and fermentable mixed bacteria in primary sludge, and the conversion rate of available carbon sources is relatively low. The amount of biochemical activated sludge is much higher than that of primary sludge, and the activated sludge contains rich aerobic, anoxic and facultative bacteria, which can directly provide microbial inoculation of mixed bacteria for the sludge hydrolysis process.

[0004] In view of this, considering recycling activated sludge as a supplementary carbon source, reducing the external carbon source in the 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 pool and a sedimentation tank connected in sequence according to the flow direction of sewage, the biochemical pool having an anoxic zone for biochemical reaction and an aerobic zone for biochemical reaction, and also 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 mixed liquid rich in carbon source and flows into the biochemical pool, 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 is built adjacent to the biochemical tank 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 plug flow agitator, the submersible plug flow agitator is installed in the hydrolysis tank and evenly distributed along the long axis direction of the hydrolysis tank;

[0009] 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 a mud pit is provided 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 agitator is arranged in the biochemical reaction anoxic zone, an aeration device is arranged 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 rectangular sedimentation tank with side inlet and side outlet, 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 pool volume.

[0014] Preferably, the suspended filler device comprises:

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

[0016] A central suspension box is fixedly mounted on the inner wall of the central fixed cylinder, and a plurality of external openings are circumferentially provided at 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. A plurality of inner openings are opened in the circumferential direction of the inner ring end of the annular suspension box. The inner openings are adapted to the outer openings.

[0018] The communication openings, 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, it also includes four lifting components circumferentially installed on the outer wall of the central fixed cylinder near the top, the lifting components are connected to the annular suspension box, when the lifting components drive the annular suspension box to rise and fall, the inner opening and the outer opening are misaligned, thereby adjusting the flow area of ​​the connecting port connecting the outer opening and the inner opening, the lifting components include:

[0021] A side mounting plate, the side mounting plate is fixedly mounted on the outer wall of the central fixed cylinder;

[0022] An upper mounting seat and a lower mounting seat, wherein the upper mounting seat and the lower mounting seat are mounted on the side mounting plate, and the central rotating shaft is rotatably mounted on the upper mounting seat and the lower mounting seat;

[0023] An upper sleeve shaft, the upper sleeve shaft is installed 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] An upper sleeve, which 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 through 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] A lower sliding sleeve, the lower sliding sleeve is sleeved on the central rotating shaft, a main gear is installed at the bottom end of the lower sliding sleeve, the main gear is sleeved on the central rotating shaft, a locking groove is opened at the bottom end of the main gear, and a locking block adapted to the locking groove is installed on the central rotating shaft;

[0029] A return spring, wherein the symmetrically distributed return spring is connected between the lower 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] A side rotating shaft, the side rotating shaft is rotatably mounted on the lower mounting seat through a side mounting frame, and a secondary gear adapted to the main gear is mounted near the bottom end of the side rotating shaft;

[0032] The lifting block is sleeved on the side rotating shaft, and two annular reciprocating grooves are opened on the side rotating shaft. The lifting block slides along the annular reciprocating grooves. The transmission rack is installed on the lifting block, and the transmission gear with 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, each group of spray pipes is equipped with spray heads at equal intervals, each group of spray pipes is equipped with a secondary sprocket, an avoidance opening is opened on the flap, 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 transmission is connected between the main sprocket and the secondary sprocket, the installation shaft can be bent to facilitate the flap to flip upwards, and 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 implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

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

[0036] Figure 2 The carbon source recovery unit structure of the present invention is shown in FIG. Figure 1 ;

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

[0038] Figure 4 The carbon source recovery unit structure of the present invention is shown in FIG. 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 The lifting assembly structure of the present invention is schematically shown in FIG. Figure 1 ;

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

[0042] Figure 8 It is a schematic diagram of the lifting block of the present invention cooperating on the side rotating shaft;

[0043] Fig. 9 The lifting assembly structure of the present invention is schematically shown in FIG. Figure 2 (When the annular suspension box is raised).

[0044] In the 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. Biochemical reaction anoxic zone; 22. Biochemical reaction aerobic zone; 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. Reset spring; 75. Push 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; 85. Main sprocket; 86. Chain belt; 87. Power element; 88. Ear; 89. Limiting slide groove; 90. Flip rod. DETAILED DESCRIPTION

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

[0046] Example

[0047] The present invention will be further described below in conjunction with 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 pool 2 and a sedimentation pool 3 connected in sequence according to the flow direction of sewage, the biochemical pool 2 having a biochemical reaction anoxic zone 21 and a biochemical reaction aerobic zone 22, and also comprising: a sludge return system 4 and a sludge treatment system 5, the sludge return system 4 returns the sludge in the sedimentation pool 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 pool 2, and the remaining sludge in the carbon source recovery unit 1 and the sedimentation pool 3 is discharged to the sludge treatment system 5.

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

[0050] The biological denitrification reactor with carbon source recovery function provided by the present invention is a composite reactor, which includes a carbon source recovery unit 1, a biochemical pool 2 and a sedimentation pool 3, wherein the sewage from the sewage treatment plant is sent into the carbon source recovery unit 1 after pretreatment and mixed with the return sludge, and the carbon source recovery unit 1 is used to hydrolyze and ferment the biologically active sludge to obtain a carbon source-rich mixed liquid and residual sludge; the biochemical pool 2 is used to perform biochemical treatment on the incoming water to remove ammonia nitrogen and total nitrogen in the water to obtain a sludge mixed liquid; the biochemical pool includes a biochemical reaction anoxic zone 21 and a biochemical reaction aerobic zone 22; the sedimentation pool 3 is used to screen and separate the sludge mixed liquid into mud and water to obtain return sludge, residual sludge and supernatant, and the sludge return system 4 returns the return sludge in the sedimentation pool 3 to the biochemical reaction anoxic zone 21 and the carbon source recovery unit 1. In order to prevent odor pollution, the carbon source recovery unit 1 and the biochemical reaction anoxic zone 21 are closed, and ventilation ducts and deodorization equipment are set.

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

[0052] Advantage 1: The mixed liquid rich in carbon source flows into the biochemical pool 2 to supplement the carbon source required in the biochemical process, thereby solving the problem of large amount of external carbon source added and high sludge output in the existing process, thereby reducing the daily operation cost of the sewage plant and the sludge disposal cost.

[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, not only for new sewage treatment plants, but also for upgrading existing sewage treatment plants. It is suitable for industrial sewage denitrification projects with low C / N ratios. Through the sludge carbon source recovery device, the insufficient carbon source of the influent can be supplemented. It can be applied to new sewage or sewage 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-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;

[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 direction 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 adopts a sloped structure to improve the sludge discharge effect. The sludge discharge pipe adopts a multi-point sludge discharge method. The hydrolysis tank 11 is also equipped with online instruments such as a mud level meter, a pH meter, and a temperature sensor to monitor and control the sludge reaction process. The mud 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 at 6.5-8.0 (the optimal hydrolysis acidification range); 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 to be arranged around the biochemical reaction aerobic zone 22. A submersible flow mixer is arranged in the biochemical reaction anoxic zone 21, and an aeration device is arranged 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] The biochemical pool 2 adopts A / O denitrification technology. The biochemical reaction anoxic zone 21 and the biochemical reaction aerobic zone 22 are separated by only one wall. The nitrification liquid reflux device 23 can reflux the nitrification liquid more conveniently, and the power of the nitrification liquid reflux pump is reduced, which is more energy-saving. The biochemical pool 2 can also adopt other biochemical methods, such as SBR, oxidation ditch, biofilm method, etc. This process mainly removes ammonia nitrogen and total nitrogen in 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 suspension filler device 13 includes:

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

[0071] A central suspension box 32, 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 opened at 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. Suspension fillers are placed in 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 a plurality of inner openings 35, and the inner openings 35 are adapted to the outer openings 34.

[0073] The communication openings 36 are equal in number to the inner openings 35 and are circumferentially disposed on the central fixed cylinder 31 and are transitionally connected to 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 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 of the central fixed cylinder 31. The aperture of the annular aeration pipe is 1 mm and the pore density is 50 pores / 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 the change of 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 flow in an interconnected manner through the inner opening 35, the connecting port 36 and the outer opening 34.

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

[0078] A side mounting plate 61, the 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, and 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 formed 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 66;

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

[0083] A vertical pull rod 70 , the top end of which is slidably mounted on the flap 68 , and the bottom end of which 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 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 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 flap 68 to flip to a horizontal state through the flip rod 90. The vertical pull rod 70 that cooperates with the flap 68 drives the annular suspension box 33 to fall back. The lower part of the annular grid plate 37 in the annular suspension box 33 The volume of the space on the side increases, and the flow area of ​​the connecting port 36 connecting 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 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] A lower sleeve 71, which is sleeved on the central shaft 64, a main gear 72 is rotatably mounted on the bottom end of the lower sleeve 71, the main gear 72 is sleeved on the central shaft 64, a locking groove is formed at the bottom end of the main gear 72, and a locking block 73 adapted to the locking groove is mounted on the central shaft 64;

[0089] The 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] Push rods 75, two groups of push rods 75 are symmetrically distributed around the central shaft 64, the push rods 75 are passed through the upper mounting seat 62 and connected to the upper sleeve 67, the push rods 75 are used to resist the lower sliding sleeve 71 to perform a sinking movement, and the top of the lower sliding sleeve 71 is symmetrically equipped with two ears 88 to facilitate the push rod 75 to resist and cooperate with the reset spring 74;

[0091] A side shaft 76, the side shaft 76 is rotatably mounted on the lower mounting seat 63 through a side mounting frame, and 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 two annular reciprocating grooves. The lifting block 78 slides along the two annular reciprocating grooves. 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] The power element 87 rotates forward, the upper sleeve 67 falls back to the lowest position, and the flap 68 flips to a horizontal state. 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 the outer opening 34 and the inner opening 35 is the largest. The upper sleeve 67 presses the ear 88 through the push rod 75, thereby driving the lower sleeve 71 to move in the contraction direction of the return spring 74. When the lower sleeve 71 drives the main gear 72 to descend until the main gear 72 and the sub-gear 77 are meshed, the locking groove is clamped on the locking block 73.

[0095] Then the power element 87 rotates in the reverse direction and drives the central shaft 64 connected to its output end to rotate. At this time, the ratchet and the pawl do not cooperate, and the central shaft 64 cannot drive the upper sleeve shaft 65 to rotate in the reverse direction. However, due to the cooperation between the locking groove and the locking block 73, when the central shaft 64 rotates in the reverse direction, the main gear 72 and the sub-gear 77 meshing with the main gear 72 are driven to rotate. The sub-gear 77 drives the side shaft 76 to rotate on the side mounting frame. Under the cooperation of the annular reciprocating groove 2 on the side shaft 76 and the lifting block 78, the transmission gear 76 is driven. The rack 79 performs reciprocating lifting motion, thereby driving the transmission gear 80 meshing with the transmission rack 79 and the installation shaft 69 connected to the transmission gear 80 to perform periodic positive and negative rotation, thereby driving the spray assembly 7 connected to the installation shaft 69 and installed at the bottom end of the flap 68 to rotate, and 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 position of the connecting port 36, thereby improving the intercommunication 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 intercommunication 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 is needed again 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, and 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 66 and the upper sleeve 67, the upper sleeve 67 is lifted up, and then the horizontal flap 68 is driven to flip through the flip rod 90, and the horizontal flap 68 drives the annular suspension box 33 to lift 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 and equipped with a spray head 82, each group of spray pipes 81 is equipped with a secondary sprocket 83, an escape opening 84 is opened on the flap 68, the installation shaft 69 extends into the escape opening 84, the main sprocket 85 is located in the escape opening 84 and is installed on the installation shaft 69, the chain belt 86 is transmission-connected between the main sprocket 85 and the secondary sprocket 83, the installation shaft 69 can be bent to facilitate the flap 68 to flip upward, and when the flap 68 is in a horizontal state, the installation shaft 69 drives the main sprocket 85 to rotate in the escape 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 positive and negative 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, 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 slide groove 89 as the center.

[0101] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A biological denitrification reactor with carbon source recovery function, characterized in that: The invention comprises a carbon source recovery unit (1), a biochemical pool (2) and a sedimentation pool (3) which are connected in sequence according to the flow direction of sewage. The biochemical pool (2) is provided with a biochemical reaction anoxic zone (21) and a biochemical reaction aerobic zone (22). The invention also comprises a sludge return system (4) and a sludge treatment system (5). The sludge return system (4) returns the sludge in the sedimentation pool (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 generate a mixed liquid rich in carbon source and flows into the biochemical pool (2). The residual sludge in the carbon source recovery unit (1) and the sedimentation pool (3) is discharged to the sludge treatment system (5).

2. A biological denitrification reactor with carbon source recovery function according to claim 1, characterized in that: The carbon source recovery unit (1) comprises: A hydrolysis tank (11), the hydrolysis tank (11) and the biochemical tank (2) are built adjacent to each other and separated by a partition wall, and 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) is installed in the hydrolysis tank (11).

3. A biological denitrification reactor with carbon source recovery function according to claim 2, 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).

4. 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-pushing agitator is arranged in the biochemical reaction anoxic zone (21). An aeration device is arranged 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 arranged to facilitate reflux of the nitrification liquid in the biochemical reaction aerobic zone (22) to the biochemical reaction anoxic zone (21).

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

6. The biological denitrification reactor with carbon source recovery function according to claim 2, characterized in that: 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 pool volume.

7. The biological denitrification reactor with carbon source recovery function according to claim 2, characterized in that: The suspension filler device (13) comprises: a central fixed cylinder (31) fixedly located at the center of the hydrolysis tank (11); a central suspension box (32) fixedly installed on the inner wall of the central fixed cylinder (31), and a plurality of outer openings (34) are opened in the circumferential direction of the side end of the central suspension box (32); an annular suspension box (33) sleeved on the outer wall of the central fixed cylinder (31), and the central suspension box (32) and the annular suspension box (33) are both provided with suspension fillers, and the annular suspension box (33) is provided with a plurality of outer openings (34) and a plurality of outer openings (34) are opened in the circumferential direction of the side end of the central suspension box (32); and the annular suspension box (33) is provided with a suspension filler. The inner ring end of the annular suspension box (33) is provided with a plurality of inner openings (35) in the circumferential direction, and the inner openings (35) are adapted to be arranged with the outer openings (34); the connecting openings (36) having the same number as the inner openings (35) are provided in the circumferential direction on the central fixed tube (31), and are transitionally connected to the outer openings (34) and the inner openings (35); the annular grid plate (37) divides the annular suspension box (33) into two upper and lower independent chambers, and the annular grid plate (37) is fixedly mounted on the central fixed tube (31).

8. The biological denitrification reactor with carbon source recovery function according to claim 7, characterized in that: The invention also comprises four lifting assemblies (6) circumferentially mounted on the outer wall of the central fixed cylinder (31) near the top end, wherein the lifting assemblies (6) comprise: 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 The upper sleeve shaft (65) is provided with an annular reciprocating groove (66); the upper sleeve (67) is sleeved on the upper sleeve shaft (65) and slides along the annular reciprocating groove (66); the flap (68) is rotatably mounted on the upper mounting seat (62) through the mounting shaft (69), and the 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).

9. The biological denitrification reactor with carbon source recovery function according to claim 8, characterized in that: The lifting assembly (6) further comprises: a lower sleeve (71) sleeved on the central rotating shaft (64), a main gear (72) being installed at the bottom end of the lower sleeve (71), the main gear (72) being sleeved on the central rotating 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 installed on the central rotating shaft (64); symmetrically distributed return springs (74) being connected between the lower sleeve (71) and the lower mounting seat (63); symmetrically distributed push rods (75) being passed through the upper mounting seat (62) and connected to the upper sleeve (67), the push rods (75) being used to resist the lower sleeve (71) to make The side rotating shaft (76) is rotatably mounted on the lower mounting seat (63) through the side mounting frame, and a secondary gear (77) adapted to the main gear (72) is mounted on the side rotating shaft (76) near the bottom end; the lifting block (78) is sleeved on the side rotating shaft (76), and an annular reciprocating groove 2 is opened on the side rotating shaft (76), and the lifting block (78) slides along the annular reciprocating groove 2, 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.

10. The biological denitrification reactor with carbon source recovery function according to claim 9, characterized in that: The spray assembly (7) comprises: two groups of spray pipes (81) symmetrically mounted at the bottom end of the flap (68), each group of spray pipes (81) being evenly spaced and equipped with a spray head (82), each group of spray pipes (81) being equipped with a secondary sprocket (83), a evacuation opening (84) being provided on the flap (68), a mounting shaft (69) extending into the evacuation opening (84), a main sprocket (85) being located in the evacuation opening (84) and mounted on the mounting shaft (69), a chain belt (86) being transmission-connected between the main sprocket (85) and the secondary sprocket (83), the mounting shaft (69) being bendable so as to facilitate the flap (68) to flip upwards, and when the flap (68) is in a horizontal state, the mounting shaft (69) drives the main sprocket (85) to rotate in the evacuation opening (84).

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