Compact aerobic granular sludge reactor

Abstract

The invention relates to the technical field of sewage treatment, in particular to a compact aerobic granular sludge reactor which comprises a reactor shell, a sludge discharge pipe, a water inlet device, an aeration device, an overflow tank and an air isolation plate. The reactor shell is of a cylindrical structure, and the water inlet device and the aeration device are mounted at the bottom of the interior of the reactor shell; the water inlet device is connected with the water inlet pipe, the water inlet device is connected with the air inlet pipe, the water inlet pipe and the air inlet pipe penetrate out of the circumferential side wall of the reactor shell, and the sludge discharge pipe is connected with the center position of the bottom wall of the reactor shell; the overflow grooves are radially arranged at the upper port of the reactor shell, and a water passing opening is formed between every two adjacent overflow grooves. The invention provides a reactor for producing compact aerobic granular sludge. The reactor effectively overcomes the defect that a reactor special for producing compact aerobic granular sludge is lacked at present.

Description

Technical Field

[0001] The invention relates to the technical field of sewage treatment, in particular to a dense aerobic granular sludge reactor. Background Art

[0002] Aerobic Granular Sludge (AGS) technology is an efficient biological sewage treatment process with advantages such as excellent sedimentation performance, high biomass, and simultaneous nitrogen and phosphorus removal. However, in actual operation, the structural stability of sludge particles directly affects its sedimentation performance and pollutant removal efficiency. According to the morphology and microbial composition, aerobic granular sludge can be mainly divided into two categories: dense granular sludge and filamentous granular sludge. Fig.11 As shown in Figure 1, dense granular sludge has a compact structure and a fast settling rate. It is usually dominated by functional microorganisms such as polyphosphate-accumulating organisms (PAOs) and nitrifying bacteria, and can efficiently remove organic matter and nutrients. Fig.10 As shown in the figure, the filamentous granular sludge has a loose structure and poor sedimentation performance, which is mainly caused by the excessive proliferation of heterotrophic bacteria (OHOs), which can easily cause sludge swelling and affect the solid-liquid separation effect.

[0003] In the AGS reactor, the growth rate of heterotrophic bacteria (OHOs) is usually higher than that of functional bacteria (such as PAOs, nitrifying bacteria, etc.). If the distribution of organic matter is not effectively controlled during the anaerobic stage, heterotrophic bacteria will preferentially use soluble organic matter (such as glucose, VFAs, etc.) for rapid proliferation, resulting in an increase in the proportion of filamentous granular sludge and a decrease in the settling performance of the sludge (such as an increase in the SVI value). Current studies have shown that encouraging functional microorganisms (such as PAOs) to absorb organic matter in sewage as much as possible at the end of the anaerobic stage can effectively reduce the available substrates for heterotrophic bacteria, thereby inhibiting their excessive growth.

[0004] However, there is still a lack of reactors on the market that are specifically designed to produce dense aerobic granular sludge to increase the speed of sewage treatment. Summary of the invention

[0005] The object of the present invention is to provide a dense aerobic granular sludge reactor to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A dense aerobic granular sludge reactor comprises a reactor shell, a sludge discharge pipe, a water inlet device, an aeration device, an overflow trough, and an air isolation plate: the reactor shell is a cylindrical tube structure, the water inlet device and the aeration device are installed at the bottom of the reactor shell, the water inlet device is connected to the water inlet pipe, the water inlet device is connected to the air inlet pipe, the water inlet pipe and the air inlet pipe pass through the circumferential side wall of the reactor shell, and the sludge discharge pipe is connected to the center of the bottom wall of the reactor shell; the overflow troughs are radially arranged at the upper port of the reactor shell, and there are water outlets between adjacent overflow troughs. The outer end of the overflow trough is connected to the circumferential side wall of the reactor shell, and the inner end of the overflow trough is connected to the mounting seat at the center of the upper port of the reactor shell. An annular water receiving trough is provided on the outer side of the upper port of the reactor shell, and the bottom of the water receiving trough is connected to a water outlet pipe, and the water receiving trough is located below the outer end of the overflow trough. The air isolation plate is an annular structure, and the air isolation plate is slidably mounted on the mounting seat and is lightweight and can float and rise and fall.

[0008] Furthermore, a circle of guide holes is distributed in a circular array on the mounting seat, the air isolation plate is fixedly mounted on the center plate above it, a circle of guide rods extending vertically downward is fixedly connected to the center plate, and the guide rods are slidably mounted in the guide holes through linear bearings.

[0009] Furthermore, a groove is provided at the center of the mounting seat, an electric push rod is installed in the groove, a top plate is fixedly installed at the end of the telescopic rod of the electric push rod, and the top plate is located directly below the center plate.

[0010] Furthermore, a spiral plate is rotatably installed at the center of the bottom of the reactor shell, and the end of the rotating shaft of the spiral plate extends from the mud discharge pipe and is drivingly connected to a motor installed outside the reactor shell.

[0011] Furthermore, the water inlet device comprises a circle of annular water balancing pipes, on which branch pipes extending toward the center of the reactor shell are distributed in an annular array, and water outlets are provided on the left and right side walls of the branch pipes.

[0012] Furthermore, the aeration device comprises a plurality of concentric annular air pipes, all of which are connected via radial ventilation pipes, and aeration seats are distributed in an annular array on the annular air pipes.

[0013] Furthermore, a funnel-shaped mud guiding slope is provided at the bottom of the reactor shell.

[0014] Furthermore, the branch pipe is arranged obliquely in the longitudinal section of the reactor shell, and the branch pipe is closely attached to the mud guiding inclined surface.

[0015] Furthermore, the positions of the annular air pipes are successively lowered from the outside to the inside, and the distances between all the annular air pipes and the mud guiding slope are equal.

[0016] Furthermore, the water inlet pipe is also connected to an external carbon source adding pipe.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The present invention automatically seals the liquid surface through the floating design of the air isolation plate, reduces oxygen infiltration in the anaerobic stage, controls the low oxygen environment, and inhibits the excessive growth of OHO by absorbing all organic matter as much as possible in the anaerobic stage, thereby increasing the proportion of dense granular sludge formation and reducing the proportion of filamentous granular sludge formation, thereby improving the sewage treatment rate.

[0019] 2. The mud slope of the present invention optimizes sedimentation, and the sludge particles slide to the bottom along the funnel-shaped slope, which improves the sludge discharge efficiency and prevents accumulation. The inclined branch pipe is close to the mud guide slope, and the outlet sprays in both directions to form a circulation, which promotes sludge mixing and organic matter diffusion. The stepped annular air pipe is evenly aerated, and the air pipe layout with decreasing height from the outside to the inside is equidistant from the slope, ensuring uniform distribution of bubbles, strengthening aerobic metabolism and particle stability.

[0020] 3. The external carbon source addition tube in the present invention can add easily degradable organic matter in the anaerobic stage, further increasing the proportion of dense granular sludge formation and reducing the proportion of filamentous granular sludge formation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is an appearance diagram of a dense aerobic granular sludge reactor;

[0022] Figure 2 It is a schematic diagram of the structural decomposition of the upper end of the reactor;

[0023] Figure 3 It is a schematic diagram of the structure of the port on the reactor shell;

[0024] Figure 4 It is a structural schematic diagram of an air isolation plate;

[0025] Figure 5 is a cross-sectional view of a dense aerobic granular sludge reactor;

[0026] Figure 6 It is a structural schematic diagram of the water inlet device;

[0027] Figure 7 It is a partial enlarged view of the water inlet device;

[0028] Figure 8 It is a structural schematic diagram of an aeration device;

[0029] Fig. 9 It is a structural schematic diagram of a stepped water inlet device;

[0030] Fig.10This is a physical picture of filamentous aerobic granular sludge;

[0031] Fig.11 This is a picture of dense aerobic granular sludge

[0032] In the figure: 1. Reactor shell; 3. Mud discharge pipe; 5. Spiral plate; 6. Water inlet pipe; 7. External carbon source addition pipe; 8. Water equalization pipe; 9. Branch pipe; 10. Water outlet; 11. Water inlet device; 12. Air inlet pipe; 13. Annular air pipe; 14. Vent pipe; 15. Aeration seat; 16. Aeration device; 17. Water receiving trough; 18. Water outlet pipe; 19. Water outlet; 20. Overflow trough; 21. Mounting seat; 22. Guide hole; 23. Electric push rod; 24. Top plate; 25. Air isolation plate; 26. Center plate; 27. Guide rod. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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.

[0034] Example 1: Please refer to Figures 1 to 9 A dense aerobic granular sludge reactor, comprising a reactor shell 1, a sludge discharge pipe 3, a water inlet device 11, an aeration device 16, an overflow tank 20, and an air isolation plate 25: the reactor shell 1 is a cylindrical tube structure, the water inlet device 11 and the aeration device 16 are installed at the bottom of the reactor shell 1, the water inlet device 11 is connected to the water inlet pipe 6, the water inlet device 11 is connected to the air inlet pipe 12, the water inlet pipe 6 and the air inlet pipe 12 pass through the circumferential side wall of the reactor shell 1, the sludge discharge pipe 3 is connected to the center of the bottom wall of the reactor shell 1; the overflow tank 20 is located at the bottom of the reactor shell 1; the aeration device 16 is located at the bottom of the reactor shell 1; the water inlet device 11 is connected to the water inlet pipe 6, the water inlet device 11 is connected to the air inlet pipe 12, the water inlet pipe 6 and the air inlet pipe 12 pass through the circumferential side wall of the reactor shell 1, the sludge discharge pipe 3 is connected to the center of the bottom wall of the reactor shell 1; the overflow tank 20 is located at the bottom of the reactor shell 1; the water inlet device 11 is connected to the air inlet pipe 12, the air inlet pipe 12 passes through the circumferential side wall ... The upper end of the reactor shell 1 is arranged radially, and there are water outlets 19 between adjacent overflow grooves 20. The outer ends of the overflow grooves 20 are connected to the circumferential side walls of the reactor shell 1, and the inner ends of the overflow grooves 20 are connected to the mounting seat 21 at the center of the upper end of the reactor shell 1. An annular water receiving groove 17 is provided on the outer side of the upper end of the reactor shell 1, and a water outlet pipe 18 is connected to the bottom of the water receiving groove 17. The water receiving groove 17 is located below the outer end of the overflow groove 20. The air isolation plate 25 is an annular structure. The air isolation plate 25 is slidably mounted on the mounting seat 21 and is lightweight and can float and rise and fall.

[0035] A circle of guide holes 22 are distributed in a circular array on the mounting seat 21, and an air isolation plate 25 is fixedly mounted on a center plate 26 above it. A circle of guide rods 27 extending vertically downward is fixedly connected to the center plate 26, and the guide rods 27 are slidably mounted in the guide holes 22 via linear bearings.

[0036] A groove is provided at the center of the mounting seat 21 , and an electric push rod 23 is installed in the groove. A top plate 24 is fixedly installed at the end of the telescopic rod of the electric push rod 23 , and the top plate 24 is located directly below the center plate 26 .

[0037] A spiral plate 5 is rotatably mounted at the center of the bottom of the reactor shell 1 . The end of the rotating shaft of the spiral plate 5 extends from the mud discharge pipe 3 and is drivingly connected to a motor 4 mounted outside the reactor shell 1 .

[0038] Working principle of this embodiment:

[0039] Anaerobic stage water inlet and anaerobic environment establishment: sewage enters the water inlet device 11 through the water inlet pipe 6, and the air inlet pipe 12 is closed to prevent gas from entering, ensuring that there is no oxygen input into the reactor. As sewage enters, the water level in the reactor rises, and the relatively clean water overflows from the overflow tank 20 to the water receiving tank 17 and is discharged through the outlet pipe 18, while the heavier sludge particles sink to the bottom. The air isolation plate 25 automatically floats to the surface of the clean water due to buoyancy, forming a physical barrier to reduce the diffusion of oxygen in the atmosphere into the reactor.

[0040] PAOs preferentially absorb organic matter: In an anaerobic environment, polyphosphate bacteria PAOs preferentially absorb volatile fatty acids VFAs in sewage and store them as PHA, while the proliferation of heterotrophic bacteria OHOs is inhibited due to the lack of quickly available substrates.

[0041] After the aerobic and anaerobic phases are over, the electric push rod 23 pushes the top plate 24 upward, driving the center plate 26 and the air isolation plate 25 downward to separate them from the water surface, thereby increasing the contact area between the water and the air inside the reactor. The aeration device 16 introduces air, and oxygen diffuses evenly through the water port 19, promoting PAOs to use the stored PHA for phosphorus absorption and nitrifying bacteria metabolism.

[0042] During the sludge discharge stage, the spiral plate 5 is driven by the motor 4 to rotate, pushing a portion of the sludge at the bottom to the sludge discharge pipe 3 for centralized discharge, thereby preventing the sludge from being too old.

[0043] This embodiment automatically seals the liquid surface through the floating design of the air isolation plate 25, reduces oxygen infiltration in the anaerobic stage, controls the low oxygen environment, and inhibits the excessive growth of OHO by absorbing as much organic matter as possible in the anaerobic stage, thereby increasing the proportion of dense granular sludge formation and reducing the proportion of filamentous granular sludge formation, thereby increasing the sewage treatment rate.

[0044] Example 2: Please refer to Figures 6 to 8 A dense aerobic granular sludge reactor is different from Example 1 in that a water inlet device 11 includes a circle of annular water balancing pipes 8, on which branch pipes 9 extending toward the center of a reactor shell 1 are distributed in an annular array, and water outlets 10 are provided on the left and right side walls of the branch pipes 9.

[0045] The aeration device 16 includes a plurality of concentric annular air pipes 13 . All the annular air pipes 13 are connected through radial ventilation pipes 14 . Aeration seats 15 are distributed in an annular array on the annular air pipes 13 .

[0046] In this embodiment

[0047] The sewage is distributed to each branch pipe 9 through the water averaging pipe 8, and the water is discharged in two directions through the water outlet 10, so as to avoid the disturbance caused by the water inlet process affecting the flow of sludge particles to the upper clean water, and ensure the drainage water quality. The air is transported to the concentric annular air pipe 13 through the vent pipe 14, and forms microbubbles through the aeration seat 15, which optimizes the distribution of dissolved oxygen, improves the oxygen mass transfer efficiency, and strengthens the formation of dense sludge particles.

[0048] Example 3: Please refer to Figure 5 , 6 and 9, a dense aerobic granular sludge reactor, which differs from embodiments 1 and 2 in that a funnel-shaped sludge guiding slope 2 is provided at the bottom of the reactor shell 1.

[0049] The branch pipe 9 is arranged obliquely in the longitudinal section of the reactor shell 1 , and the branch pipe 9 is closely attached to the mud guiding slope 2 .

[0050] The positions of the annular air pipes 13 are gradually reduced from the outside to the inside, and the distances between all the annular air pipes 13 and the mud guiding slope 2 are equal.

[0051] In this embodiment, the mud slope 2 optimizes sedimentation, and the sludge particles slide to the bottom along the funnel-shaped slope, which improves the sludge discharge efficiency and prevents accumulation. The inclined branch pipe 9 is close to the mud guide slope 2, and the water outlet 10 sprays in both directions to form a circulation, which promotes sludge mixing and organic matter diffusion. The stepped annular air pipe 13 is evenly aerated, and the air pipe layout with decreasing height from the outside to the inside is equidistant from the slope, ensuring uniform distribution of bubbles, strengthening aerobic metabolism and particle stability.

[0052] Example 4: Please refer to Figure 1 , a dense aerobic granular sludge reactor, which is different from Example 1 in that an external carbon source addition pipe 7 is also connected to the water inlet pipe 6.

[0053] In this embodiment, the external carbon source addition tube 7 can add easily degradable organic matter (such as sodium acetate and propionic acid) in the anaerobic stage, which is preferentially absorbed by PAOs and stored as PHAs, rather than being used by ordinary heterotrophic bacteria of OHO, thereby further increasing the proportion of dense granular sludge formation and reducing the proportion of filamentous granular sludge formation.

Claims

1. A dense aerobic granular sludge reactor, characterized in that: It comprises a reactor shell (1), a mud discharge pipe (3), a water inlet device (11), an aeration device (16), an overflow tank (20), and an air isolation plate (25): The reactor shell (1) is a cylindrical tube-shaped structure. The water inlet device (11) and the aeration device (16) are installed at the bottom of the reactor shell (1). The water inlet device (11) is connected to the water inlet pipe (6). The water inlet device (11) is connected to the air inlet pipe (12). The water inlet pipe (6) and the air inlet pipe (12) pass through the circumferential side wall of the reactor shell (1). The mud discharge pipe (3) is connected to the center position of the bottom wall of the reactor shell (1). The overflow grooves (20) are arranged radially at the upper end of the reactor shell (1), and a water outlet (19) is provided between adjacent overflow grooves (20). The outer ends of the overflow grooves (20) are connected to the circumferential side wall of the reactor shell (1), and the inner ends of the overflow grooves (20) are connected to a mounting seat (21) at the center of the upper end of the reactor shell (1). An annular water receiving groove (17) is provided on the outer side of the upper end of the reactor shell (1), and a water outlet pipe (18) is connected to the bottom of the water receiving groove (17). The water receiving groove (17) is located below the outer end of the overflow groove (20). The air isolation plate (25) is an annular structure. The air isolation plate (25) is slidably mounted on the mounting seat (21) and is lightweight and can float and rise and fall.

2. A dense aerobic granular sludge reactor according to claim 1, characterized in that: A circle of guide holes (22) are distributed in a circular array on the mounting seat (21); the air isolation plate (25) is fixedly mounted on a center plate (26) above the air isolation plate; a circle of guide rods (27) extending vertically downward are fixedly connected to the center plate (26); the guide rods (27) are slidably mounted in the guide holes (22) via linear bearings.

3. A dense aerobic granular sludge reactor according to claim 2, characterized in that: A groove is provided at the center of the mounting seat (21), an electric push rod (23) is installed in the groove, a top plate (24) is fixedly installed at the end of the telescopic rod of the electric push rod (23), and the top plate (24) is located directly below the center plate (26).

4. A dense aerobic granular sludge reactor according to claim 1, characterized in that: A spiral plate (5) is rotatably mounted at the center of the bottom of the reactor shell (1); the end of the rotating shaft of the spiral plate (5) extends out of the mud discharge pipe (3) and is drivingly connected to a motor (4) mounted outside the reactor shell (1).

5. The dense aerobic granular sludge reactor according to claim 1, characterized in that: The water inlet device (11) comprises a ring-shaped water balancing pipe (8), on which branch pipes (9) extending toward the center of the reactor shell (1) are distributed in a ring-shaped array, and water outlets (10) are provided on the left and right side walls of the branch pipes (9).

6. A dense aerobic granular sludge reactor according to claim 1, characterized in that: The aeration device (16) comprises a plurality of concentric annular air pipes (13), all of which are connected via radial ventilation pipes (14), and aeration seats (15) are distributed in an annular array on the annular air pipes (13).

7. A dense aerobic granular sludge reactor according to claim 1, 5 or 6, characterized in that: A funnel-shaped mud guiding slope (2) is provided at the bottom of the reactor shell (1).

8. A dense aerobic granular sludge reactor according to claim 7, characterized in that: The branch pipe (9) is arranged obliquely in the longitudinal section of the reactor shell (1), and the branch pipe (9) is closely attached to the mud guiding inclined surface (2).

9. A dense aerobic granular sludge reactor according to claim 7, characterized in that: The positions of the annular air pipes (13) are successively lowered from the outside to the inside, and the distances between all the annular air pipes (13) and the mud guiding slope (2) are equal.

10. The dense aerobic granular sludge reactor according to claim 1, characterized in that: The water inlet pipe (6) is also connected to an external carbon source addition pipe (7).

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