Aerated sedimentation integrated device and control method for granular sludge screening

Abstract

The present application belongs to sewage treatment technical field, disclose a kind of granular sludge screening aeration sedimentation integrated equipment and control method, comprising: barrel, the middle part of the barrel is provided with aeration clarification zone, the middle part of the barrel is located at the position outside aeration clarification zone and is provided with anoxic zone, the inside of aeration clarification zone is located at the position of one side of anoxic zone and is provided with oxygen zone, the inside of aeration clarification zone is located at the position of one side of oxygen zone and is provided with sludge screening zone, the inside of aeration clarification zone is located at the position of one side of sludge screening zone and is provided with pre-anoxic zone, the position of pre-anoxic zone side is close to aeration clarification zone and is provided with sludge reflux zone, sludge reflux system flows back part of sludge to pre-anoxic zone, at this time, further digestion treatment is carried out, sludge treatment efficiency is improved, sludge amount is reduced, and sludge concentration can be extracted by peristaltic pump, enter sludge screening zone, to better cultivate aerobic granular sludge.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, and in particular relates to an integrated aeration and sedimentation device and control method for screening granular sludge. Background Technology

[0002] Currently, aerobic biological reactors are widely used in wastewater treatment processes to remove ammonia nitrogen. However, they also have problems such as easy caking, insufficient active sedimentation, and difficulty in controlling biofilm morphology, which affect denitrification efficiency. In addition, many aerobic sludge treatment systems cannot effectively remove phosphorus from the water, resulting in the discharge of inferior wastewater and pollution of the water environment.

[0003] To improve the nitrogen and phosphorus removal efficiency of aerobic granular sludge wastewater treatment systems, many improvement schemes have been developed in recent years, such as:

[0004] The stability and activity of sludge can be improved by adding polymerizing agents and co-culturing microorganisms.

[0005] By adjusting the reaction conditions, the growth environment of aerobic microorganisms can be optimized;

[0006] Using a multi-stage aerobic reactor improves nitrogen removal efficiency;

[0007] High-concentration aerobic sludge is used to treat highly eutrophic water bodies to improve phosphorus removal rate.

[0008] Although the application of the aforementioned technologies has yielded some results, it is still difficult to effectively solve the problems mentioned above. Existing technologies often have the disadvantage of being inconvenient for sludge recycling. Therefore, there is an urgent need for a new type of aerobic granular sludge wastewater treatment equipment that can effectively improve nitrogen and phosphorus removal efficiency, reduce operating costs, and better protect the aquatic environment. Summary of the Invention

[0009] This invention addresses the problem of inconvenient sludge recycling in existing technologies by proposing the following technical solution:

[0010] An integrated aeration and sedimentation device for screening granular sludge includes: a cylindrical body; an aeration and clarification zone is provided in the middle of the cylindrical body; an anoxic zone is provided in the middle of the cylindrical body outside the aeration and clarification zone; an aerobic zone is provided inside the aeration and clarification zone on one side of the anoxic zone; a sludge screening zone is provided inside the aeration and clarification zone on one side of the aerobic zone; a pre-anoxic zone is provided inside the aeration and clarification zone on one side of the sludge screening zone; a sludge return zone is provided on one side of the pre-anoxic zone near the aeration and clarification zone; and an anaerobic zone is provided on one side of the pre-anoxic zone near one end of the anoxic zone.

[0011] As a preferred embodiment of the above technical solution, a water outlet pipe is provided in the middle of the aeration and clarification area, and the water outlet pipe penetrates the cylinder.

[0012] As a preferred embodiment of the above technical solution, a supernatant outlet pipe is embedded in the inner wall of the cylinder at one side of the sludge screening zone, a sludge discharge pipe is embedded in the inner wall of the cylinder at the bottom end of the supernatant outlet pipe, and an external return water pipe is embedded in the inner wall of the cylinder at the bottom end of the sludge discharge pipe.

[0013] As a preferred embodiment of the above technical solution, the top of the aeration clarification zone is set as a clarification zone, and the bottom of the aeration clarification zone is set as an aeration zone.

[0014] As a preferred embodiment of the above technical solution, the interior of the aeration clarification zone is equipped with several mud-water separation module inclined plates, and the same inclined plate is installed between one end of the several mud-water separation module inclined plates. A return port is opened in the middle of one end of the inclined plate, and air lifting pipes are symmetrically embedded on both sides inside the inclined plate. An exhaust hole is opened at the bottom of the return port on one end of the inclined plate, and an exhaust pipe is embedded at the top of the inner wall of the inclined plate.

[0015] As a preferred embodiment of the above technical solution, both the aeration clarification zone and the sludge return zone are equipped with peristaltic pumps. The outlet end of the peristaltic pump in the aeration clarification zone is connected to the internal return inlet pipe, and the outlet end of the peristaltic pump in the sludge return zone is connected to the external return water pipe.

[0016] As a preferred embodiment of the above technical solution, the supernatant outlet pipe and the supernatant inlet pipe are connected by a pipeline, and the inner diameters of the supernatant outlet pipe, the supernatant inlet pipe, the external return inlet pipe and the internal return inlet pipe are equal.

[0017] As a preferred embodiment of the above technical solution, the number of inclined plates in the mud-water separation module is set to two sets, with the bottom set of inclined plates being inclined plates in shape and the top set of inclined plates being inverted V-shaped plates.

[0018] A control method for an integrated aeration and sedimentation device in an aerobic granular sludge wastewater treatment system includes the following steps:

[0019] Step 1: Sludge screening process control in the screening zone:

[0020] By controlling the flow rate of the external return water pipe, the influent flow rate of the sludge screening zone is adjusted, thereby controlling the sludge return flow rate.

[0021] The flow rate of the supernatant outlet pipe and the supernatant inlet pipe is controlled to adjust the speed at which the mixed liquor enters the aerobic zone from the sludge screening zone.

[0022] By controlling the operating conditions of the sludge discharge device to control the sludge screening volume and the intermittent opening and closing of the sludge discharge electric valve, the activated sludge is better compressed and gradually cultivated into aerobic granular sludge.

[0023] Step Two: Aeration and Hypoxia Control

[0024] Based on the detection of COD, TN and TP concentrations in the wastewater, the aeration rate in the aeration clarification area is adjusted.

[0025] Nitrate nitrogen is removed by adjusting the reflux ratio in the anoxic zone;

[0026] Biological phosphorus removal is achieved by adjusting the sludge return ratio in the anaerobic zone;

[0027] By adjusting the aeration rate in the aerobic zone, the solubility of oxygen in the water can be increased, thereby controlling the changes in dissolved oxygen.

[0028] Step 3: Control of the aeration and clarification zone:

[0029] By controlling the tilt angle of the inclined plate of the sludge-water separation module, the sludge settling speed and the supernatant flow direction can be adjusted.

[0030] By adjusting the flow rate of the airlift pipe, sludge settling and upward movement of air bubbles are promoted, thereby improving the system's aeration efficiency.

[0031] By adjusting the parameters of aeration volume, airlift pipe length, and tilt angle of the sludge-water separation module, a hydraulic flow state of airlift circulation is formed within the device. When the aeration volume and airlift pipe length are increased, the airlift circulation volume is significantly increased, preventing flocculent sludge with poor settling performance from settling and allowing it to flow out with the water flow, while granular sludge with excellent settling performance remains within the device. Increasing the tilt angle of the sludge-water separation module further promotes the return of aerobic granular sludge to the aerobic zone system, thereby achieving the screening of aerobic granular sludge through the integrated aeration and sedimentation tank.

[0032] Step 4: System Parameter Control

[0033] Adjust the flow rate of the effluent pipe according to the amount of wastewater to be treated, and maintain the stable operation of the system.

[0034] Adjust the valves of the supernatant outlet pipe and sludge discharge pipe according to the supernatant return pressure and sludge concentration to control the discharge rate of supernatant and sludge.

[0035] Step 5: Data Detection: Collect wastewater data using data acquisition equipment and monitor it in real time through a monitoring system.

[0036] The beneficial effects of this invention are as follows:

[0037] (1) The sludge return system returns a portion of the sludge to the pre-anoxic zone for further digestion, which improves the sludge treatment efficiency and reduces the amount of sludge. The sludge concentrate can be extracted by a peristaltic pump and enter the sludge screening zone, thereby better cultivating aerobic granular sludge.

[0038] (2) The aeration and inclined plate sludge-water separation technology is adopted to effectively remove organic matter in sewage. Under the action of the air lift pipe, an air lift circulation is formed, which can better screen and cultivate aerobic granular sludge, promote biological reaction, and further improve the organic matter removal rate.

[0039] (3) The design of the sludge screening zone controls the amount of activated sludge entering the sludge screening zone. Through the thickening function of the sludge screening zone, some of the sludge is thickened and enters the pre-anoxic zone, and then flows into the anaerobic zone, anoxic zone, etc., to maintain the sludge concentration balance of the entire system.

[0040] (4) Process control of sludge screening zone: control the inflow velocity and outflow velocity of supernatant in sludge screening zone, and control the upward flow velocity of sludge in screening zone. Control the upward flow velocity to 3-5 m / h. Flocculent sludge with poor settling properties rises with the water flow, while granular sludge with good settling properties settles at the bottom of the screening zone and is returned to the pre-anoxic zone.

[0041] (5) The design and operation of the mud-water separation module: the air-lift circulation flow prevents flocculent sludge with poor settling performance from settling and flows out with the water flow, while granular sludge with excellent settling performance is retained in the equipment. The adjustment of the aeration volume, air lift pipe and inclined plate angle of the mud-water separation module further promotes the return of aerobic granular sludge to the aerobic zone system, thereby achieving the screening of aerobic granular sludge through the integrated aeration sedimentation tank. Attached Figure Description

[0042] Figure 1 The diagram shown is a structural schematic of an integrated aeration and sedimentation device for screening granular sludge in Example 1.

[0043] Figure 2 The image shown is a left view of the cylinder in Embodiment 1;

[0044] Figure 3 The image shown is a top view of the cylinder in Embodiment 1;

[0045] Figure 4 The diagram shown is a schematic of the installation structure of the water outlet pipe in Embodiment 1;

[0046] Figure 5 The diagram shown is a cross-sectional view of the cylinder in Embodiment 1;

[0047] Figure 6 The diagram shown is a schematic diagram of the installation structure of the inclined plate of the mud-water separation module in Embodiment 1;

[0048] Figure 7 The diagram shown is a structural schematic of the inclined plate angle of the mud-water separation module in Embodiment 1.

[0049] In the diagram: 1. Cylinder; 2. Aeration and clarification zone; 3. Anoxic zone; 4. Aerobic zone; 5. Sludge screening zone; 6. Supernatant outlet pipe; 7. Supernatant inlet pipe; 8. Sludge discharge pipe; 9. Pre-anoxic zone; 10. Sludge return zone; 11. External return inlet pipe; 12. Anaerobic zone; 13. Internal return inlet pipe; 14. Outlet pipe; 21. Sludge-water separation module inclined plate; 22. Inclined plate; 23. Return port; 24. Air lift pipe; 25. Exhaust port; 26. Exhaust pipe. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments.

[0051] Example 1:

[0052] This invention provides an integrated aeration and sedimentation device and control method for screening granular sludge, such as... Figures 1 to 7 As shown, it includes: a cylinder 1, an aeration and clarification zone 2 in the middle of the cylinder 1, an anoxic zone 3 in the middle of the cylinder 1 located outside the aeration and clarification zone 2, an aerobic zone 4 inside the aeration and clarification zone 2 located to one side of the anoxic zone 3, a sludge screening zone 5 inside the aeration and clarification zone 2 located to one side of the aerobic zone 4, a pre-anoxic zone 9 inside the aeration and clarification zone 2 located to one side of the sludge screening zone 5, a sludge return zone 10 on one side of the pre-anoxic zone 9 near the aeration and clarification zone 2, and an anaerobic zone 12 on one side of the pre-anoxic zone 9 near one end of the anoxic zone 3.

[0053] like Figure 1 and Figure 2 As shown, a water outlet pipe 14 is provided in the middle of the aeration and clarification zone 2, and the water outlet pipe 14 penetrates the cylinder 1;

[0054] The treated wastewater inside the aeration clarification zone 2 is discharged along the outlet pipe 14, allowing the liquid to be discharged.

[0055] like Figure 1 and Figure 3 As shown, a supernatant outlet pipe 6 is embedded in the inner wall of the cylinder 1 at one side of the sludge screening zone 5, a sludge discharge pipe 8 is embedded in the inner wall of the cylinder 1 at the bottom end of the supernatant outlet pipe 6, and an external return water pipe 11 is embedded in the inner wall of the cylinder 1 at the bottom end of the sludge discharge pipe 8.

[0056] By rationally arranging the supernatant outlet pipe 6 and the sludge discharge pipe 8, sludge can be effectively separated from the supernatant. The supernatant outlet pipe 6 is located on one side of the sludge screening area 5. After the sludge is screened, the supernatant can be directly discharged from this area. The sludge discharge pipe 8 is located at the bottom of the supernatant outlet pipe 6 and can collect the final sludge that has been screened. The external return water pipe 11 is designed at the bottom of the sludge discharge pipe 8, which can send a portion of the sludge that has passed the screening back to the sludge screening area 5 for further treatment. This can improve the sludge dewatering rate and treatment efficiency and reduce wastewater discharge.

[0057] like Figure 4 and Figure 5 As shown, the top of the aeration clarification zone 2 is set as the clarification zone, and the bottom of the aeration clarification zone 2 is set as the aeration zone. Several mud-water separation module inclined plates 21 are installed inside the aeration clarification zone 2. The same inclined plate 22 is installed between one end of the several mud-water separation module inclined plates 21. A return port 23 is opened in the middle of one end of the inclined plate 22. Air lifting pipes 24 are symmetrically embedded on both sides inside the inclined plate 22. An exhaust hole 25 is opened at the bottom of the return port 23 at one end of the inclined plate 22. An exhaust pipe 26 is embedded in the top of the inner wall of the inclined plate 22.

[0058] The air lift pipe 24 is used to carry air bubbles into the sludge layer, increasing the aeration of the sludge layer, promoting the biological reaction of microorganisms, and effectively removing organic matter from the sewage. The exhaust port 25 facilitates the blowing out of some of the air discharged in the clarification area, while the exhaust pipe 26 can collect some of the excess gas on the sludge removal surface for energy recovery.

[0059] like Figure 3 and Figure 5 As shown, both the aeration clarification zone 2 and the sludge return zone 10 are equipped with peristaltic pumps. There are two peristaltic pumps in the aeration clarification zone 2. The outlet end of the peristaltic pump in the aeration clarification zone 2 is connected to the inner return inlet pipe 13. The outlet end of the other peristaltic pump in the aeration clarification zone 2 is located inside the sludge screening zone 5. The outlet end of the peristaltic pump in the sludge return zone 10 is connected to the outer return water pipe 11.

[0060] The mixed liquor inside the aeration and clarification zone 2 enters the internal return inlet pipe 13 through a peristaltic pump, and finally enters the anoxic zone 3 along the internal return inlet pipe 13 to form a reflow. At the same time, the sludge pumped by the peristaltic pump in the sludge return zone 10 enters the sludge screening zone 5 along the external return water pipe 11 for re-screening. By using the precise control of the peristaltic pump and the return method, the reliability and efficiency of the sewage treatment system can be effectively improved.

[0061] like Figure 2 and Figure 3As shown, the supernatant outlet pipe 6 and the supernatant inlet pipe 7 are connected by a pipe, and the inner diameters of the supernatant outlet pipe 6, the supernatant inlet pipe 7, the external return inlet pipe 11 and the internal return inlet pipe 13 are equal.

[0062] This facilitates the flow of liquid between the supernatant outlet pipe 6 and the supernatant inlet pipe 7. At the same time, the inner diameters of the supernatant outlet pipe 6, the supernatant inlet pipe 7, the external return inlet pipe 11, and the internal return inlet pipe 13 ensure that the maximum flow velocity is the same among the inner diameters of the supernatant outlet pipe 6, the supernatant inlet pipe 7, the external return inlet pipe 11, and the internal return inlet pipe 13, thereby making the overall equipment operate more smoothly.

[0063] like Figure 5 and Figure 6 As shown, the number of inclined plates 21 in the mud-water separation module is set to two sets. The bottom set of inclined plates 21 is in the shape of an inclined plate, and the top set of inclined plates 21 is in the shape of an inverted V-shaped plate. The angle of the inclined plates 21 in the inverted V-shaped plate is 60 degrees, which is the optimal angle. The inclined length of the inclined plates 21 in the inverted V-shaped plate is 300cm, and the distance between the inclined plates 21 in the inverted V-shaped plate and the inner wall of the aeration clarification zone 2 is 380cm.

[0064] The inclined plate 21 of the sludge-water separation module can guide the sludge to flow along a predetermined path, making the sludge-water separation more stable and effective. The inverted V-shaped plate of the sludge-water separation module 21 increases the area of ​​sludge contact with the separation module and improves the separation efficiency.

[0065] A control method for an integrated aeration and sedimentation device in an aerobic granular sludge wastewater treatment system includes the following steps:

[0066] Step 1: Sludge screening process control in the screening zone:

[0067] By controlling the flow rate of the external return water pipe 11, the influent flow rate of the sludge screening zone 5 is adjusted, and the sludge return flow rate is controlled, so that an appropriate amount of activated sludge enters the sludge screening zone 5. Through the thickening function of the sludge screening zone 5, some of the sludge is thickened and enters the pre-anoxic zone 9, and then flows into the anaerobic zone 12, the anoxic zone 3, etc., to maintain the sludge concentration balance of the entire system, while promoting some activated sludge to form aerobic granular sludge through screening.

[0068] By controlling the flow rates of the supernatant outlet pipe 6 and the supernatant inlet pipe 7, the speed at which the mixed liquor enters the aerobic zone 4 from the sludge screening zone 5 is adjusted; the upward flow velocity of the sludge in the sludge screening zone 5 is controlled at 3-5 m / h, and the flocculent sludge with poor settling properties rises with the water flow; the granular sludge with good settling properties settles at the bottom of the sludge screening zone 5 and flows back to the pre-anoxic zone 9.

[0069] By controlling the operating conditions of the sludge discharge device to control the sludge screening volume and the intermittent opening of the sludge discharge electric valve, the activated sludge is better selected and compressed, and gradually cultivated into aerobic granular sludge.

[0070] Step Two: Aeration and Hypoxia Control

[0071] Based on the detection of COD, TN and TP concentrations in the wastewater, the aeration rate in aeration clarification zone 2 is adjusted.

[0072] Nitrate nitrogen is removed by adjusting the reflux ratio in anoxic zone 3;

[0073] Adjusting the sludge return ratio in anaerobic zone 12 can indeed effectively improve the biological phosphorus removal capacity, thus enabling the biochemical system to remove phosphorus more effectively.

[0074] By adjusting the aeration rate in aerobic zone 4, the solubility of oxygen in the water can be increased, thereby controlling the changes in dissolved oxygen.

[0075] Step 3: Control of the aeration and clarification zone:

[0076] By controlling the tilt angle of the inclined plate 21 of the sludge-water separation module, the sludge settling velocity and the supernatant flow direction are adjusted. Simultaneously, when the aeration rate is increased and the length of the airlift pipe 24 is increased, the airlift circulation flow rate is significantly enhanced. This prevents poorly settling flocculent sludge from settling and causes it to flow out with the water. To achieve good gas-liquid separation, the hypotenuses of the upper and lower triangular gas collection hoods must overlap to a certain extent. The greater the horizontal overlap, the better the gas separation effect. Therefore, the amount of overlap is crucial in determining the quality of gas-liquid separation (e.g., ...). Figure 7 As shown, the rising gas, solid, and liquid mixed water flow in the reaction zone transitions through the lower triangular gas collection hood return slit to the upper triangular gas collection hood return slit, and then enters the sedimentation zone.

[0077] By adjusting the flow rate of the air lift pipe 24, sludge settling and upward movement of air bubbles are promoted, thereby improving the system's sludge-water separation efficiency.

[0078] By adjusting the aeration volume, the length of the airlift pipe 24, and the tilt angle of the inclined plate 21 of the sludge-water separation module, a hydraulic flow state of airlift circulation is formed within the device, enabling the screening of aerobic granular sludge. At the top of the sludge-water separation module, light flocculent sludge flows out of the tank with the water, while heavy granular sludge slides down into the reactor tank through the hydraulic flow state of airlift circulation.

[0079] A mathematical model of airlift circulation was established to calculate the liquid velocity of granular sludge descending during the circulation process. This model was then used to calculate the flow rate of airlift circulation for different parameters such as aeration volume, airlift pipe 24 size, and tilt angle of sludge-water separation module inclined plate 21. By adjusting these parameters, suitable granular sludge was selected.

[0080] The mathematical model for airlift is as follows:

[0081] As the bubble rises, it is acted upon by buoyancy, gravity, and resistance. The dynamic equation for the bubble's ascent is:

[0082]

[0083] In the formula: ρ L and ρ g These are the densities of the liquid and air, respectively.

[0084] d p The diameter of the bubble;

[0085] g is the acceleration due to gravity, taken as 9.8 m / s². 2 ;

[0086] V is the liquid flow velocity;

[0087] C D This is called the drag coefficient;

[0088] Upflow zone:

[0089]

[0090] In the formula:

[0091] Re is the bubble Reynolds coefficient;

[0092] Dynamic viscosity η is a dynamic characteristic parameter of water: at room temperature (20℃), η

[0093] =1.005x10 -3 Pas.;

[0094] υ is the kinematic viscosity of water. At room temperature (20℃), υ = 1.007 × 10⁻⁶. -6 m 2 / s

[0095] Based on the assumption that the bubble diameter remains constant, the bubble will undergo an acceleration followed by a uniform ascent from its formation to the water surface. When the acceleration is 0, the acceleration phase ends and the uniform ascent begins. The corresponding velocity is generally called the final velocity. The ascent of the bubble in the water involves an acceleration followed by a uniform ascent. After the bubble emerges from the bubble generator at the bottom of the river, its initial velocity is 0 m / s. As the rising height changes, it undergoes variable acceleration until it reaches its final velocity.

[0096] Based on the above formula, the formula for calculating the final velocity is as follows:

[0097] Upflow zone:

[0098]

[0099] In the formula:

[0100] V g This refers to the rising speed of the bubble;

[0101] Bubble rise time:

[0102] Upflow zone:

[0103]

[0104] In the formula: t g —The residence time of the bubble in the upflow region;

[0105] H—Height of the upflow zone;

[0106] Gas holdup in the upflow region:

[0107]

[0108] Where: e—gas holdup in the upflow region;

[0109] Q g —Aeration rate;

[0110] A – Cross-sectional area of ​​the upflow region;

[0111] II. Mathematical Model of the Flow Zone

[0112] In a three-phase gas-lift internal circulation reactor, based on the principle that the driving force caused by the difference in gas holdup in the riser and downcomer balances the resistance to fluid flow, a mathematical model is established to predict the circulating liquid velocity. For this gas-liquid-solid three-phase system, the pressure difference caused by the different gas holdup in the riser and downcomer can be expressed as follows based on the energy equation:

[0113]

[0114] In the formula: e d : Gas holdup in the downdraft region;

[0115] e1: Gas holdup in the upflow region;

[0116] u d Liquid velocity in the downflow region (m / s);

[0117] u1: Liquid velocity in the upflow zone (m / s);

[0118] L1: Height of the upflow zone (m);

[0119] Since the gas mainly escapes upwards from the top of the rising region, the gas entrained in the falling region is negligible. d =0,

[0120] Then we can obtain:

[0121]

[0122] Since the flow rates in the upwelling and downwelling regions are equal, therefore:

[0123]

[0124] In the formula: u d Flow velocity at the outlet in the downflow region (m / s);

[0125] A d : Cross-sectional area of ​​the downflow outlet, m 2 ;

[0126] A1: Cross-sectional area of ​​the upflow region, m 2 ;

[0127] Therefore, the flow velocity in the rising circulation of the descending region is:

[0128]

[0129] Mathematical models show that the circulation velocity of the airlift circulation system is related to parameters such as the air holdup in the upflow zone, the height of the upflow zone, the cross-sectional area of ​​the upflow zone, and the cross-sectional area of ​​the downflow zone. The circulation velocity can be controlled by adjusting design parameters and operating conditions. This allows for the discharge of flocculent sludge with poor settling properties from the upper part of the sludge-water separation module, while granular sludge with excellent settling properties slides down from the top of the sludge-water separation module to the bottom biochemical reaction zone via the airlift circulation system.

[0130] The granular sludge with excellent settling performance is retained in the equipment. The inclination angle of the sludge return zone 10 is increased, which further promotes the return of aerobic granular sludge to the aerobic zone 4 system, thereby achieving the screening of aerobic granular sludge through the integrated aeration sedimentation tank.

[0131] Step 4: System Parameter Control

[0132] Adjust the flow rate of the effluent pipe 14 according to the amount of sewage to be treated, and maintain the stable operation of the system.

[0133] Adjust the valves of the supernatant outlet pipe 6 and the sludge discharge pipe 8 according to the return pressure of the supernatant and the sludge concentration to control the discharge rate of the supernatant and sludge.

[0134] Step 5: Data Detection: Collect wastewater data using data acquisition equipment and monitor it in real time through a monitoring system.

[0135] Working Principle: In actual use, the aerobic granular sludge wastewater treatment equipment receives wastewater entering the cylinder 1 and then the aeration and clarification zone 2. Since the bottom of the aeration and clarification zone 2 is the aeration zone and the top is the clarification zone, the sludge is guided by the inclined sludge-water separation module sloping plate 21 at the bottom of the aeration and clarification zone 2, allowing the sludge to flow along a predetermined path. This results in more stable and effective sludge-water separation. The inverted V-shaped sludge-water separation module sloping plate 21 increases the contact area between the sludge and the separation module, improving separation efficiency. Furthermore, by adjusting the aeration volume, the length of the air lift pipe 24, and the tilt angle of the sludge return zone 10, a hydraulic flow state of airlift circulation is formed within the device. When the aeration volume increases and the length of the air lift pipe 24 increases, the airlift circulation volume increases significantly, preventing flocculent sludge with poor settling performance from settling and allowing it to flow out with the water flow. Granular sludge with excellent settling performance remains within the device. The increased tilt angle of the sludge return zone 10 further promotes the return of aerobic granular sludge to the aerobic zone 4 system, thereby achieving the screening of aerobic granular sludge through the integrated aeration and sedimentation tank.

[0136] Meanwhile, water at the top of the aeration clarification zone 2 is discharged along the outlet pipe 14, while part of the mixed liquor in the middle of the aeration clarification zone 2 is drawn into the sludge screening zone 5 by a peristaltic pump. At this time, the mixed liquor is screened in the sludge screening zone 5, and the screened sludge is settled. At the same time, the mixed liquor at the top of the sludge screening zone 5 enters the supernatant inlet pipe 7 along the supernatant outlet pipe 6, and then enters the aerobic zone 4 along the supernatant inlet pipe 7. Then it enters the sludge screening zone 5 again along the aerobic zone 4, realizing one return.

[0137] Then, the mixed liquor at the top of the sludge screening zone 5 enters the pre-anoxic zone 9. At this time, the mixed liquor in the pre-anoxic zone 9 undergoes further sedimentation. The sedimented sludge enters the sludge return zone 10 and is extracted by the peristaltic pump inside the sludge return zone 10. After extraction, it enters the sludge screening zone 5 again along the external return water pipe 11. Then, the sludge discharge pipe 8 inside the sludge screening zone 5 is opened to discharge the sludge. At the same time, the mixed liquor in the pre-anoxic zone 9 flows through the top into the anaerobic zone 12. The mixed liquor in the anaerobic zone 12 flows through the bottom into the anoxic zone 3. The mixed liquor in the anoxic zone 3 flows through the top into the aerobic zone 4. Finally, it enters the sludge screening zone 5 along the aerobic zone 4, realizing internal recirculation.

[0138] Meanwhile, part of the mixed liquor inside the aeration and clarification zone 2 is directly pumped into the anoxic zone 3 by a peristaltic pump, then flows through the top of the anoxic zone 3 into the aerobic zone 4, and finally enters the sludge screening zone 5 along the aerobic zone 4. This process treats the wastewater multiple times. Through multiple internal and external circulation treatments, the wastewater continuously circulates between the aerobic zone 4, the anoxic zone 3, and the anaerobic zone 12, allowing the wastewater to come into contact with different microbial environments multiple times. This effectively removes various organic substances, thereby significantly reducing the degree of water pollution and improving water quality.

[0139] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it.

Claims

1. An integrated aeration and sedimentation device for screening granular sludge, characterized in that, include: A cylindrical body (1) is provided with an aeration clarification zone (2) in the middle of the cylindrical body (1). An anoxic zone (3) is provided in the middle of the cylindrical body (1) at the position outside the aeration clarification zone (2). An aerobic zone (4) is provided inside the aeration clarification zone (2) at the position on one side of the anoxic zone (3). A sludge screening zone (5) is provided inside the aeration clarification zone (2) at the position on one side of the aerobic zone (4). A pre-anoxic zone (9) is provided inside the aeration clarification zone (2) at the position on one side of the sludge screening zone (5). A sludge return zone (10) is provided on one side of the pre-anoxic zone (9) near the position of the aeration clarification zone (2). An anaerobic zone (12) is provided on one side of the pre-anoxic zone (9) near the position of one end of the anoxic zone (3). The top of the aeration clarification zone (2) is set as a clarification zone, and the bottom of the aeration clarification zone (2) is set as an aeration zone; The aeration clarification zone (2) is equipped with several mud-water separation module inclined plates (21). The same inclined plate (22) is installed between one end of several mud-water separation module inclined plates (21). A return port (23) is opened in the middle of one end of the inclined plate (22). Air lifting pipes (24) are symmetrically embedded on both sides inside the inclined plate (22). An exhaust hole (25) is opened at the bottom of the return port (23) at one end of the inclined plate (22). An exhaust pipe (26) is embedded at the top of the inner wall of the inclined plate (22). The number of inclined plates (21) of the mud-water separation module is set to two sets. The bottom set of inclined plates (21) of the mud-water separation module is in the shape of an inverted L-shaped plate, and the top set of inclined plates (21) of the mud-water separation module is in the shape of an inverted V-shaped plate. The return port (23) is located above the inclined plate (21) of the mud-water separation module, and the air lift pipe (24) is located inside the bottom set of inclined plates (21) of the mud-water separation module.

2. The integrated aeration and sedimentation equipment for screening granular sludge according to claim 1, characterized in that, A water outlet pipe (14) is provided in the middle of the aeration and clarification area (2), and the water outlet pipe (14) penetrates the cylinder (1).

3. The integrated aeration and sedimentation equipment for screening granular sludge according to claim 2, characterized in that, The inner wall of the cylinder (1) is embedded with a supernatant outlet pipe (6) located on one side of the sludge screening area (5). The inner wall of the cylinder (1) is embedded with a sludge discharge pipe (8) located at the bottom of the supernatant outlet pipe (6). The inner wall of the cylinder (1) is embedded with an external return water pipe (11) located at the bottom of the sludge discharge pipe (8).

4. The integrated aeration and sedimentation equipment for screening granular sludge according to claim 3, characterized in that, Both the aeration clarification zone (2) and the sludge return zone (10) are equipped with peristaltic pumps. The outlet end of the peristaltic pump in the aeration clarification zone (2) is connected to the inner return inlet pipe (13), and the outlet end of the peristaltic pump in the sludge return zone (10) is connected to the outer return water pipe (11).

5. The integrated aeration and sedimentation equipment for screening granular sludge according to claim 4, characterized in that, The supernatant outlet pipe (6) and the supernatant inlet pipe (7) are connected by a pipe, and the inner diameters of the supernatant outlet pipe (6), the supernatant inlet pipe (7), the external return inlet pipe (11) and the internal return inlet pipe (13) are equal.

6. A control method for an integrated aeration and sedimentation device for granular sludge screening according to claim 5, characterized in that, Includes the following steps: Step 1: Sludge screening process control in the screening zone: The inflow rate of the sludge screening zone (5) is adjusted by controlling the flow rate of the external return water pipe (11); By controlling the flow rates of the supernatant outlet pipe (6) and the supernatant inlet pipe (7), the speed at which the mixed liquor enters the aerobic zone from the sludge screening zone (5) is adjusted. Step Two: Aeration and Hypoxia Control Based on the detection of COD, TN and TP concentrations in the wastewater, the aeration rate in the aeration clarification zone (2) is adjusted. Nitrate nitrogen is removed by adjusting the reflux ratio in the anoxic zone (3); By adjusting the sludge return ratio in the anaerobic zone (12), the biological phosphorus removal capacity can be effectively improved, so that the biochemical system can better remove phosphorus. By adjusting the aeration rate in the aerobic zone (4), the solubility of oxygen in the water can be increased, thereby controlling the change in dissolved oxygen. Step 3: Control of the aeration and clarification zone: By controlling the tilt angle of the inclined plate (21) of the sludge-water separation module, the sludge settling speed and the supernatant flow direction can be adjusted. By adjusting the flow rate of the air lift pipe (24), sludge settling and upward movement of air bubbles are promoted, thereby improving the system's aeration efficiency. Step 4: System Parameter Control Adjust the flow rate of the outlet pipe (14) according to the amount of sewage to be treated, and maintain the stable operation of the system. Adjust the valves of the supernatant outlet pipe (6) and the sludge discharge pipe (8) according to the return pressure of the supernatant and the sludge concentration to control the discharge rate of the supernatant and sludge; Step 5: Data Detection: Collect wastewater data using data acquisition equipment and monitor it in real time through a monitoring system.

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