Vertical flow type oxidation ditch sewage treatment equipment and sewage treatment process

Abstract

The invention discloses vertical flow type oxidation ditch sewage treatment equipment and a sewage treatment process, the sewage treatment equipment comprises an equipment main body, the equipment main body is internally provided with a plurality of biochemical reaction zones and settling zones which are sequentially connected in series; a sludge return area is arranged at the bottoms of the partition plates of the plurality of biochemical reaction areas, sludge in the sludge return area flows back to the first biochemical reaction area through a gas stripping return device and is mixed with inlet water of an equipment water inlet pipe, and the rear end of the sludge return area is communicated with the sludge deposition area; a bidirectional aeration device is arranged between every two adjacent biochemical reaction areas; the bottom sludge backflow area is additionally arranged, and compared with a traditional oxidation ditch process, the overall biomass in equipment can be increased, and the sewage treatment effect is improved; through the arrangement of the bidirectional aeration device, the aeration holes in the lower part of the aeration disc face the sludge backflow area, so that an air layer is formed in the oxidation ditch process and the sludge backflow position, and the effects of promoting sludge backflow, preventing sludge from aging and stacking and reducing the sludge dewatering difficulty can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of urban domestic sewage treatment, and in particular to a vertical flow oxidation ditch sewage treatment equipment and a sewage treatment process. Background Art

[0002] In recent years, with the development of urban sewage treatment, more and more integrated sewage treatment equipment has appeared on the market. At present, medium and large integrated sewage treatment equipment has a good application prospect. Small towns, communities, large concentrated villages and other places far away from urban management, the daily domestic and industrial sewage generated need to achieve better treatment effects before discharge.

[0003] The oxidation ditch process is mostly used in large-scale urban sewage treatment plants, with good on-site operation effects and stable effluent. However, traditional integrated oxidation ditch equipment has disadvantages such as large footprint and high energy consumption, resulting in a small share in the field of urban sewage treatment and difficulty in promotion. In addition, the activated sludge return effect in the existing oxidation ditch process is not good, which affects its treatment potential. In addition, the sludge is prone to aging and accumulation during the return process, which increases the difficulty of sludge dehydration and affects the sewage treatment capacity of the oxidation ditch. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a vertical flow oxidation ditch sewage treatment equipment and a sewage treatment process. By adding a bottom sludge reflow zone at the bottom of the equipment body, compared with the traditional oxidation ditch process, the overall biomass in the equipment can be increased and the sewage treatment effect can be improved.

[0005] The technical solution of the present invention is as follows:

[0006] In the first aspect of the present invention, a vertical flow oxidation ditch sewage treatment equipment is provided, including an equipment body, in which a plurality of biochemical reaction zones and sedimentation zones are arranged in series in sequence; a sludge reflow zone is arranged at the bottom of the partition of the plurality of biochemical reaction zones, and the sludge in the sludge reflow zone is recirculated to the first biochemical reaction zone through an air lift reflux device and mixed with water from the equipment inlet pipe, and the rear end of the sludge reflow zone is connected to the sludge accumulation zone; a bidirectional aeration device is arranged between two adjacent biochemical reaction zones.

[0007] In some embodiments of the present invention, the bidirectional aeration device uses a bidirectional aeration disk, and aeration holes are provided on the upper and lower parts of the bidirectional aeration disk, wherein the upper aeration holes face the biochemical reaction zone, and the lower aeration holes are inclined toward the sludge return zone.

[0008] In some embodiments of the present invention, three biochemical reaction zones are provided, each of which is vertically arranged, and adjacent biochemical reaction zones are separated by two grid plates.

[0009] In some embodiments of the present invention, the two grid plates are spaced apart by a set distance and are staggered, and the bidirectional aeration device is disposed between the two grid plates. The bidirectional aeration device is used to oxygenate the wastewater to be treated and lift it to the next biochemical reaction zone.

[0010] In some embodiments of the present invention, a static pressure mud discharge system is provided in the main body of the equipment, and the static pressure mud discharge system includes a mud discharge main pipe and a plurality of mud discharge branch pipes connected to the mud discharge main pipe, and the plurality of mud discharge branch pipes are respectively distributed in a plurality of biochemical reaction zones and mud accumulation zones.

[0011] In some embodiments of the present invention, the gas lift reflux device includes a sludge gas lift pipe and a gas lift branch pipe, the bottom of the sludge gas lift pipe is trumpet-shaped and is placed in the sludge at the bottom of the front end of the sludge reflux zone, the sludge outlet at the top of the sludge gas lift pipe is connected to the first biochemical reaction zone, the top of the sludge gas lift pipe is also connected to the gas lift branch pipe, and the gas lift branch pipe is connected to the fan.

[0012] In some embodiments of the present invention, the sedimentation zone is located above the sludge accumulation zone, the sedimentation zone is separated from the adjacent biochemical reaction zone by a guide plate, and the sludge accumulation zone is connected to the adjacent biochemical reaction zone; an inclined plate sedimentation structure is provided in the sedimentation zone, and a water outlet weir is provided at the water outlet of the sedimentation zone.

[0013] In some embodiments of the present invention, the water inlet pipe is connected to a lift pump, and a check valve and a flow meter are provided on the water inlet pipe.

[0014] In some embodiments of the present invention, the equipment body is painted with epoxy resin anti-corrosion paint all over, and the air-water interface in the equipment body is thermally sprayed on the basis of the epoxy resin anti-corrosion paint.

[0015] In a second aspect of the present invention, a vertical flow oxidation ditch sewage treatment process is provided, comprising:

[0016] After the sewage and the return sludge from the sludge return area enter the biochemical reaction area for uniform mixing, the pollutants are degraded through multiple biochemical reaction areas in series, and then enter the sludge accumulation area for precipitation;

[0017] The precipitated sludge returns to the front end of the equipment through the sludge return area and is mixed with the sewage to be treated again;

[0018] Among them, the sewage is raised to a high level in each biochemical reaction zone through the aeration effect of the two-way aeration device, fully dissolving the oxygen in the air, and passing through the aerobic-anoxic-anaerobic process from top to bottom to remove pollutants in the sewage.

[0019] One or more technical solutions of the present invention have the following beneficial effects:

[0020] The vertical flow oxidation ditch sewage treatment equipment provided by the present invention adds a bottom sludge return zone at the bottom of the equipment body. Compared with the traditional oxidation ditch process, it can increase the overall biomass in the equipment and improve the sewage treatment effect; through the provided two-way aeration device, the lower aeration holes of the aeration plate are directed toward the sludge return zone, so that an air layer is formed in the oxidation ditch process and the sludge return, which can promote sludge return and prevent sludge aging and accumulation, and reduce the difficulty of sludge dehydration; by providing a sludge accumulation zone after the three-stage biochemical reaction zone, the sludge accumulation zone is used as a secondary sedimentation tank, and by providing an inclined plate sedimentation zone in the sludge accumulation zone, the denitrification effect can be enhanced, and the removal of total nitrogen can be enhanced while the sludge is precipitated.

[0021] The vertical flow oxidation ditch sewage treatment equipment provided by the present invention, on the basis of the coupled equipment rooms of traditional sewage treatment equipment, obliquely divides the sedimentation tank into prismatic equipment rooms, thereby saving the overall volume while ensuring the treatment effect, thereby reducing costs and increasing efficiency.

[0022] The vertical flow oxidation ditch sewage treatment equipment provided by the present invention controls the bottom aeration of three serially connected biochemical reaction zones, thereby achieving control over the biological reactions in different chambers. When the inlet water concentration changes, the aeration intensity is adjusted to achieve precise control, thereby adapting to fluctuations in water quality and water volume and ensuring stable effluent water quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall internal structure of the vertical flow oxidation ditch sewage treatment equipment of the present invention;

[0024] Figure 2 It is the general assembly diagram of the vertical flow oxidation ditch sewage treatment equipment of the present invention;

[0025] Figure 3 A schematic diagram of an aeration plate of a bidirectional aeration device of the present invention;

[0026] Figure 4 It is a schematic diagram of the mud discharge branch pipe of the present invention;

[0027] Figure 5 It is a schematic diagram of the static pressure mud discharge system of the present invention;

[0028] Figure 6 The present invention is a flow chart of the vertical flow oxidation ditch sewage treatment process.

[0029] In the figure: 1. Equipment body; 2. Flow meter; 3. Check valve; 4. Lifting pump; 5. Air lift reflux device; 6. Two-way aeration device; 7. Grid plate; 8. Water inlet pipe; 9. Aeration main pipe; 10. Guide plate; 11. Sedimentation area; 12. Outlet weir; 13. Mud accumulation area; 14. Sludge return area; 15. Biochemical reaction area; 16. Fan; 17. Dosing system; 18. Static pressure mud discharge system; 19. Aeration branch pipe; 20. Aeration disc joint; 21. Upper aeration hole; 22. Lower aeration hole; 23. Mud discharge port; 24. Mud discharge branch pipe; 25. Mud discharge main pipe. DETAILED DESCRIPTION

[0030] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0031] Example 1

[0032] In a typical embodiment of the present invention, a vertical flow oxidation ditch sewage treatment equipment is proposed, such as Figure 1 and Figure 2 As shown, it includes an equipment body 1, in which a plurality of biochemical reaction zones 15 and a sedimentation zone 11 are arranged in series in sequence; a sludge reflow zone 14 is arranged at the bottom of the partition of the plurality of biochemical reaction zones 15, and the front end of the sludge reflow zone 14 is connected to the front end of the equipment body 1, and the rear end is connected to the sludge accumulation zone 13; the sludge in the sludge reflow zone 14 is refluxed to the first biochemical reaction zone through the air lift reflux device 5, and mixed with the water inlet pipe 8 of the equipment, and the rear end of the sludge reflow zone 14 is connected to the sludge accumulation zone 13; a bidirectional aeration device 6 is arranged between the two biochemical reaction zones 15.

[0033] like Figure 3 As shown, the bidirectional aeration device 6 adopts a bidirectional aeration disk, and aeration holes are provided at the upper and lower parts of the bidirectional aeration disk, wherein the upper aeration hole 21 faces the biochemical reaction zone 15, and the lower aeration hole 22 is inclined toward the sludge return zone 14. Specifically, the bidirectional aeration disk is connected to the aeration branch pipe 19 through the aeration disk joint 20, and the aeration branch pipe 19 is connected to the aeration main pipe 9 connected to the fan 16. The upper aeration hole 21 plays the role of aeration flow, and the lower aeration hole 22 is set to form an air layer in the oxidation ditch process and the sludge return zone, which can play the following roles: (1) promote sludge return; (2) make full use of the fan air volume; (3) prevent sludge aging and accumulation, and reduce the difficulty of sludge dehydration.

[0034] The number of biochemical reaction zones 15 is determined according to the tonnage and size of the equipment. The residence time and volume of the biochemical zone are fixed. If the daily processing volume increases and the length of the equipment increases, more reaction zones can be set. In this embodiment, three biochemical reaction zones 15 are provided. Each biochemical reaction zone 15 is vertically arranged and lifted to the next reaction zone by an intermediate oxygen flushing aeration device. The biochemical reaction zone is divided into an aeration zone at the bottom and an anoxic zone. The two-way aeration disk arranged in the aeration zone can be independently controlled. The aeration zone aerates and pushes the sewage, so that the sewage completes nitrification and denitrification in the anoxic zone.

[0035] In this embodiment, adjacent biochemical reaction zones are separated by two grid plates 7, and the two grid plates 7 are set at a set distance and staggered, so that the sewage between adjacent biochemical reaction zones is baffled. The bidirectional aeration device 6 is arranged between the two grid plates 7, and is arranged between the partitions to mainly play a lifting role, thereby pushing the water flow to dissolve more oxygen in the air. At the same time, a downward aeration port is arranged, and a small amount of air pushes the sludge backflow; compared with being set in the biochemical reaction zone, the fan air volume consumed can be reduced, so a small air volume fan can be selected to reduce the operating cost.

[0036] Specifically, an arc-shaped corner is set at the position where the grid plate 7 is connected to the bottom of the equipment body to prevent dead corners during sewage treatment; an overflow weir is set at the flow position on the top of the grid plate 7, and each biochemical reaction zone 15 passes water through the overflow weir. After the water passes to the sedimentation area of ​​the sludge accumulation area for efficient sedimentation, the sludge flows back to the water inlet pipe.

[0037] In this embodiment, the sedimentation area 11 is located at the upper part of the sludge accumulation area 13, the sedimentation area 11 is separated from the adjacent biochemical reaction area by a guide plate 10, and the sludge accumulation area 13 is connected to the adjacent biochemical reaction area; the sedimentation area 11 is provided with an inclined plate sedimentation structure, and a water outlet weir 12 is provided at the water outlet of the sedimentation area 11.

[0038] In this embodiment, a static pressure mud discharge system 18 is provided in the equipment body 1. Figure 4 and Figure 5As shown, the static pressure mud discharge system 18 includes a mud discharge main pipe 25 and a plurality of mud discharge branch pipes 24 connected to the mud discharge main pipe 25. The plurality of mud discharge branch pipes 24 are respectively distributed in the lower part of the plurality of biochemical reaction zones 15 and the mud accumulation zone 13. Specifically, a mud discharge port 23 is provided on the mud discharge branch pipe 24. The mud discharge main pipe 25 is located outside the main body of the equipment. The mud discharge main pipe is arranged toward the sludge draining tank. An exhaust pipe is provided at the highest point of the mud discharge main pipe. The static pressure mud discharge system 18 plays the role of mud discharge and equipment emptying. The equipment mud discharge is divided into two situations: (1) When the sedimentation ratio is normal, a small amount of activated sludge is discharged by the air lift mud discharge system and accumulated in the sludge tank. The supernatant is returned to the regulating tank. When the sedimented sludge is full, it is transported and dehydrated; (2) When there is a lot of sludge or the equipment needs to be emptied, the mud discharge main pipe and mud discharge branch pipes are used to discharge the mud by atmospheric pressure.

[0039] A sludge reflow zone 14 is set at the bottom of the chamber of the three biochemical reaction zones 15, and an air lift reflux device 5 is arranged near the water inlet direction. The air lift reflux device 5 includes a sludge air lift pipe and an air lift branch pipe. The bottom of the sludge air lift pipe is in a bell-mouth shape and is placed in the sludge at the bottom of the front end of the sludge reflow zone 14. The water inlet at the top of the sludge air lift pipe is connected to the first biochemical reaction zone. The top of the sludge air lift pipe is also connected to the air lift branch pipe, and the air lift branch pipe is connected to the fan. The bottom sludge is lifted to the water inlet of the equipment through the bell-mouth and the sludge gas pipe, and is evenly mixed with the incoming water. The gas route is provided by the fan, and gas is supplied through the air lift branch pipe.

[0040] In this embodiment, the water inlet pipe 8 is connected to the lifting pump 4, and a check valve 3 and a flow meter 2 are provided on the water inlet pipe 8; the domestic sewage to be treated passes through the lifting pump 4 in the regulating tank, and is pumped into the equipment body 1 for treatment after passing through the check valve 3 and the flow meter 2.

[0041] In this embodiment, the equipment body 1 is painted with epoxy resin anti-corrosion paint to prevent surface corrosion of the equipment and increase service life. The air-water junction (200 mm above and below) in the equipment body is thermally sprayed on the basis of epoxy resin anti-corrosion paint to further prevent corrosion of the extremely corrosive parts.

[0042] Based on the coupled equipment rooms of traditional sewage treatment equipment, this equipment tilts the sedimentation tank to divide it into prismatic equipment rooms for placing equipment such as fans 17 and dosing systems 16, thereby saving overall volume while ensuring treatment effects, thereby reducing costs and increasing efficiency.

[0043] like Figure 6 As shown, the working process of the vertical flow oxidation ditch sewage treatment equipment provided in this embodiment is as follows:

[0044] S1, the sewage is pre-treated and separated from the residue at the front end, and then pumped into the first biochemical reaction area for treatment through the regulating tank;

[0045] S2, the airlift return activated sludge enters the first biochemical reaction to be evenly mixed with the sewage, and then enters the subsequent series biochemical reaction zone in sequence;

[0046] S3, through the three-stage biochemical reaction zone, each stage is lifted to a high position through plug flow aeration, fully dissolving the oxygen in the air, and passing through the aerobic-anoxic-anaerobic process from top to bottom to remove pollutants in the water;

[0047] S4, enters the sludge accumulation area, settles in the inclined plate sedimentation area, and the supernatant is discharged from the equipment through the effluent weir. After the activated sludge settles, it is aerated through the air layer in three two-way aeration devices to dissolve part of the oxygen and return to the front end through air lift.

[0048] During the operation of the equipment, the aeration devices at the bottom of the three biochemical reaction zones connected in series are controlled to lift the sewage to a level close to the air surface through plug flow and complete the oxygen flushing. During the falling process, aerobic-anoxic-anaerobic conditions are completed in sequence to achieve the degradation of pollutants in the sewage.

[0049] Example 2

[0050] In a typical embodiment of the present invention, a vertical flow oxidation ditch sewage treatment process is provided, comprising:

[0051] After the sewage and the return sludge from the sludge return area enter the biochemical reaction area for uniform mixing, the pollutants are degraded through multiple biochemical reaction areas in series, and then enter the sludge accumulation area for sedimentation;

[0052] The precipitated sludge returns to the front end of the equipment through the sludge return area and is mixed with the sewage to be treated again;

[0053] Among them, the sewage is raised to a high level in each biochemical reaction zone through the aeration effect of the two-way aeration device, fully dissolving the oxygen in the air, and passing through the aerobic-anoxic-anaerobic process from top to bottom to remove pollutants in the sewage.

[0054] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A vertical flow oxidation ditch sewage treatment equipment, characterized in that: The device comprises an equipment body, in which a plurality of biochemical reaction zones and sedimentation zones connected in series are arranged in the equipment body; a sludge reflow zone is arranged at the bottom of the partition of the plurality of biochemical reaction zones, sludge in the sludge reflow zone is reflowed to the first biochemical reaction zone through an air lift reflow device, and mixed with water from the equipment water inlet pipe, and the rear end of the sludge reflow zone is connected with the sludge accumulation zone; a bidirectional aeration device is arranged between two adjacent biochemical reaction zones.

2. The vertical flow oxidation ditch sewage treatment equipment according to claim 1, characterized in that: The bidirectional aeration device adopts a bidirectional aeration disk, and aeration holes are provided at the upper and lower parts of the bidirectional aeration disk, wherein the aeration holes at the upper part face the biochemical reaction zone, and the aeration holes at the lower part are inclined toward the sludge return zone.

3. The vertical flow oxidation ditch sewage treatment equipment according to claim 1, characterized in that: There are three biochemical reaction zones, each of which is arranged vertically, and adjacent biochemical reaction zones are separated by two grid plates.

4. The vertical flow oxidation ditch sewage treatment equipment according to claim 3, characterized in that: The two grid plates are spaced apart by a set distance and are staggered. The bidirectional aeration device is arranged between the two grid plates. The wastewater to be treated is lifted to the next biochemical reaction zone by oxygenating through the bidirectional aeration device.

5. The vertical flow oxidation ditch sewage treatment equipment according to claim 1, characterized in that: A static pressure mud discharge system is arranged in the main body of the equipment, and the static pressure mud discharge system comprises a mud discharge main pipe and a plurality of mud discharge branch pipes connected to the mud discharge main pipe, and the plurality of mud discharge branch pipes are respectively distributed in a plurality of biochemical reaction zones and mud accumulation zones.

6. The vertical flow oxidation ditch sewage treatment equipment according to claim 1, characterized in that: The gas lift reflux device comprises a sludge gas lift pipe and a gas lift branch pipe. The bottom of the sludge gas lift pipe is in a trumpet shape and is placed in the sludge at the bottom of the front end of the sludge reflux zone. The sludge outlet at the top of the sludge gas lift pipe is connected to the first biochemical reaction zone. The top of the sludge gas lift pipe is also connected to the gas lift branch pipe, and the gas lift branch pipe is connected to the fan.

7. The vertical flow oxidation ditch sewage treatment equipment according to claim 1, characterized in that: The sedimentation zone is located above the sludge accumulation zone, the sedimentation zone is separated from the adjacent biochemical reaction zone by a guide plate, and the sludge accumulation zone is connected to the adjacent biochemical reaction zone; an inclined plate sedimentation structure is provided in the sedimentation zone, and a water outlet weir is provided at the water outlet of the sedimentation zone.

8. The vertical flow oxidation ditch sewage treatment equipment according to claim 1, characterized in that: The water inlet pipe is connected to the lifting pump, and a check valve and a flow meter are arranged on the water inlet pipe.

9. The vertical flow oxidation ditch sewage treatment equipment according to claim 1, characterized in that: The equipment body is painted with epoxy resin anti-corrosion paint all over, and the air-water interface in the equipment body is thermally sprayed on the basis of the epoxy resin anti-corrosion paint.

10. A vertical flow oxidation ditch sewage treatment process, using the vertical flow oxidation ditch sewage treatment equipment according to any one of claims 1 to 9, characterized in that: include: After the sewage and the return sludge from the sludge return area enter the biochemical reaction area for uniform mixing, the pollutants are degraded through multiple biochemical reaction areas in series, and then enter the sludge accumulation area for precipitation; The precipitated sludge returns to the front end of the equipment through the sludge return area and is mixed with the sewage to be treated again; Among them, the sewage is raised to a high level in each biochemical reaction zone through the aeration effect of the two-way aeration device, fully dissolving the oxygen in the air, and passing through the aerobic-anoxic-anaerobic process from top to bottom to remove pollutants in the sewage.

Images