A device for rapid construction of continuous-flow aerobic granular sludge by using multi-fold (wave) plate flow state control and steps thereof

Abstract

The application provides a continuous-flow aerobic granular sludge rapid construction device and steps thereof by using multi-fold (wave) plate flow state control, and the following device is used to realize the device. The reactor comprises, in sequence according to the water flow advancing direction, an anoxic zone, an aerobic zone and a sedimentation zone, and the interior of the reactor comprises a water inlet unit, a flow disturbing member, an aeration unit, a sludge backflow unit, a nitrification liquid backflow unit, a water outlet unit and a sludge discharge unit. The flow disturbing member is arranged in the anoxic zone and the aerobic zone, and the form of the flow disturbing member comprises a straight plate, a same-wave fold (wave) plate and a different-wave fold (wave) plate. The water flow is turned up and down under the action of the flow disturbing member, the turbulence dissipation rate and the vortex scale are controlled by adjusting the spacing and the angle of the flow disturbing member, the shear force is enhanced, the apparent gas velocity of the aerobic zone is controlled, under the action of the strong shear force of the gas and the water, the microorganisms effectively collide, the new ecological microorganisms secrete extracellular polymers, the microorganisms aggregate to form a microbial aggregate, and the aerobic granular sludge is rapidly formed.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a device and steps for rapid construction of continuous flow aerobic granular sludge using multi-fold (corrugated) plate flow control. Background Technology

[0002] The activated sludge process is a traditional wastewater treatment technology with over 100 years of development history, widely used for treating municipal and industrial wastewater. However, the activated sludge process does not meet current sustainable development requirements due to its large footprint, complex sludge return process, and high energy consumption. Aerobic granular sludge, due to its excellent settling performance, simultaneous nitrification and denitrification, small footprint, and low energy consumption, is widely considered a sustainable biological wastewater treatment technology. However, aerobic granular sludge has certain problems limiting its widespread application. First, the long granulation time of aerobic granular sludge severely restricts its engineering applications. Although many researchers have proposed various methods to enhance aerobic granular sludge, most methods still have certain limitations. For example, to promote the rapid formation of aerobic granular sludge, researchers often adjust operating parameters or add certain substances to the unit, resulting in complex unit operation, high operating costs, and secondary pollution. Secondly, current research on aerobic granular sludge mainly focuses on sequencing batch reactors (SBRs). The intermittent operation of SBRs makes it difficult to operate aerobic granular sludge technology alongside other continuous flow structures in practical engineering. Finally, the hydrodynamics of aerobic granular sludge cultivation remains unclear. This invention addresses these issues by proposing a rapid construction method for continuous flow aerobic granular sludge using multi-fold (corrugated) plate flow control. Summary of the Invention

[0003] The purpose of this invention is to enhance shear force by incorporating turbulence-inducing components within the reactor and adjusting their spacing and angle to control turbulent dissipation rate and vortex size. This allows for the rapid formation of aerobic granular sludge through strong air-water shear force at low energy consumption, addressing the problems of low pollutant removal efficiency, large footprint, and high energy consumption in existing activated sludge processes for wastewater treatment plants.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0005] A continuous flow aerobic granular sludge rapid construction device utilizing multi-fold (corrugated) plate flow pattern control, wherein the construction method is implemented through the following device: the reactor includes an influent unit, a turbulence-inducing component, an aeration unit, a sludge return unit, a nitrification liquor return unit, an effluent unit, and a sludge discharge unit; the turbulence-inducing component includes a straight plate, a corrugated plate with different corrugations, and a corrugated plate with the same corrugations.

[0006] The inlet and outlet units are used for water intake into the first compartment of the reactor. After sludge-water separation in the sedimentation tank, the water exits from the top of the sedimentation tank. The anoxic and aerobic zones within the reactor are equipped with turbulence-inducing components, including straight plates, corrugated plates, and corrugated plates. The water flow is turbulent up and down under the action of the turbulence-inducing components. The sedimentation zone is used for sludge-water separation. The aeration unit is used to selectively introduce air (oxygen) into each compartment to form an aerobic or anoxic zone. The sludge return unit uses air lifting to return sludge to the first compartment of the reactor. The nitrification liquor return unit returns the mixed liquor in the last compartment of the aerobic zone to the first compartment of the anoxic zone. The sludge discharge unit periodically discharges a certain amount of sludge from the continuous flow multi-corrugated plate reactor.

[0007] Preferably, the reactor influent flow direction is sequentially from the anoxic zone to the aerobic zone and then to the sedimentation zone; the reactor influent flow velocity is 0.20-0.50 m / s; the reactor BOD sludge loading is 0.13-0.2 kg BOD5 / (kg MLSS·d); and the denitrification rate in the anoxic zone is 0.03-0.06 kg NO. - 3-N / (kg MLSS·d); denitrification nitrogen removal rate is 0.044-0.088 kg NO - 3-N / (kg MLSS·d); the denitrification rate in the aerobic zone is 0.09-0.15 kg NH. + 4-N / (kg MLSS·d); the gas-to-water ratio of the reactor is (2.5-3.5):(0.5-1.5); the dissolved oxygen content in the anoxic zone is 0.1-0.30 mg / L; the apparent gas velocity q in the aerobic zone is 0.5-1.2 cm / s; the sludge return ratio is 60-80%, the nitrification liquor return ratio is 100-150%, and the sludge age is 15-25 days.

[0008] Preferably, the hydraulic retention time in the anoxic zone of the reactor is 0.5-3 hours, the hydraulic retention time in the aerobic zone is 1-4 hours, and the sedimentation time in the sedimentation zone is 10-60 minutes.

[0009] The method for determining the number of turbulence-inducing components in the anoxic and aerobic zones of the reactor is as follows: the number of turbulence-inducing components in each zone is determined by the volumetric load of each zone of the reactor.

[0010]

[0011] In the formula, C is the COD content of the influent (g / L), Q is the influent flow rate (L / d), V is the effective volume of each zone (L), and x is the number of turbulence components in each zone.

[0012] Preferably, the turbulence-disrupting components in the anoxic and aerobic zones of the reactor account for 30-100% of the reactor's filling ratio; the folding (corrugated) plate controls the folding angle θ to be 80-120 degrees.

[0013] The materials used for the turbulence-causing components are generally stainless steel, plastic, and wood.

[0014] Preferably, the corrugated plate accounts for 30-40% of the total number of aerobic zone turbulence components, the same corrugated plate accounts for 40-50% of the total number of aerobic zone turbulence components, and the straight plate accounts for 10-30% of the total number of aerobic zone turbulence components.

[0015] Preferably, the anoxic zone employs corrugated plates with significant velocity gradient variations. The distance between the central axes of the two corrugated plates is d, and the h / d ratio of a single corridor is controlled to be 5-10. The minimum vortex size is 50-500 mm, and the maximum vortex size is 300-1000 mm. The turbulent dissipation rate in each zone is controlled to be 0.03-0.35 m. 2 / s 3 .

[0016] Preferably, the controlled single-channel h / d is 2-10; the minimum vortex size of the corrugated plates is 50-500mm, and the maximum vortex size is 500-1500mm; the minimum vortex size of the same corrugated plates is 100-500mm, and the maximum vortex size is 500-1500mm; the controlled aerobic zone turbulent dissipation rate is 0.03-0.08m. 2 / s 3 The turbulent dissipation rate in the anoxic zone was controlled to be 0.15-0.35m. 2 / s 3 .

[0017] Preferably, the continuous flow multi-flute (corrugated) plate reactor promotes the aerobic granular sludge cultivation time for 15-25 days, with an average particle size of 300-500 μm and SVI. 30 The concentration is 45-60 mL / g, and the settling velocity is 30-55 m / h.

[0018] The COD removal rate is around 95%. The removal rate can reach over 99%, with TN removal rates between 75% and 80% and TP removal rates between 60% and 65%. After 60-80 days of cultivation, the average particle size of the aerobic granular sludge reaches 500-1000 μm, SVI30 reaches 35-40 mL / g, the settling velocity is 50-80 m / h, and the COD removal rate can reach over 95%. The removal rate can reach over 99%, the removal rate of TN is between 80% and 85%, and the removal rate of TP is between 70% and 75%; compared with the energy consumption of the blower in the biological treatment tank of the activated sludge process, the power consumption is reduced by 34%.

[0019] The operation steps of a continuous flow aerobic granular sludge rapid construction device utilizing multi-fold (corrugated) plate flow pattern control include the following steps:

[0020] S1: Reactor inoculated with activated sludge;

[0021] S2: Turn on the inlet pump to send the wastewater in the inlet tank into the reactor;

[0022] S3: Turn on the air compressor and valves to send gas into the reactor through the aeration head, and control the dissolved oxygen content in the anoxic zone by controlling the opening of the aeration valve.

[0023] S4: Activate the sludge return unit and the nitrification liquor return unit to return the sludge from the bottom of the sedimentation tank to the biological reactor and return the mixed liquor from the aerobic zone to the anoxic zone. Adjust the return unit device to control the sludge return ratio and the nitrification liquor return ratio.

[0024] S5: Turn on the effluent pump to allow the supernatant from the sedimentation tank to flow out;

[0025] S6: Sludge age should be controlled at 15-30 days.

[0026] The gas includes air (oxygen).

[0027] The influent water quality is approximately 350 mg COD, 25 mg NH4+-N, 3 mg TP, and a certain amount of trace element solution per liter of synthetic wastewater. The reactor aeration unit includes an aeration head 5, an aeration valve 6, an aeration pipe 21, and an aeration pump 8. The aeration head 5 is installed at a bend (wave). One end of the aeration valve 6 is connected to the aeration head 5, and the other end is connected to the aeration pump 8 through the aeration pipe 21. The aeration rate in the anoxic and aerobic zones is controlled by adjusting the valve opening. The air-to-water ratio in the reactor is controlled between 2.5 and 3.5:1, the dissolved oxygen content in the anoxic zone is approximately 0.2 mg / L, and the apparent gas velocity q in the aerobic zone is controlled between 0.5 and 1.2 cm / s.

[0028] The sedimentation zone is used for sludge-water separation and includes a sludge return unit, a sludge discharge unit, and a nitrification liquor return unit. To avoid breaking up granular sludge, the sludge return unit employs an air-lift return method, comprising a sludge suction pipe 9, an air inlet pipe 10, an air inlet valve 11, an air-lift tank 12, an exhaust pipe 13, an exhaust valve 14, and a sludge return pipe 15. Pressurized air is introduced into the bottom of the sludge suction pipe 9 through the air inlet valve 11 and the air inlet pipe 10, creating a sludge mixture with a lower density inside the pipe than outside. The liquid level inside the pipe is higher than that outside, and under the pressure difference, the outside mixture continuously enters from the bottom of the suction pipe 9 and is discharged into the first compartment of the reactor through the air-lift tank 12 and the sludge return pipe 15, achieving sludge return. After sludge return is completed, the exhaust valve 14 is opened, and exhaust is performed through the exhaust pipe 13, achieving equal pressure between the suction pipe 9 and the outside. The sedimentation zone is equipped with a sludge discharge unit, and the sludge discharge pipe 20 extends from the bottom of the sedimentation tank through the sludge discharge valve 19. The nitrification liquor recirculation unit uses a recirculation pump 22 to recirculate the mixed liquor from the last compartment of the aerobic zone to the first compartment of the anoxic zone, promoting denitrification and improving the nitrogen removal effect.

[0029] Preferably, in step S1, the amount of inoculated sludge is 2500-3500 mg / L; in step S2, the influent temperature is 20-30℃ and the pH value is 7.5-8.5; in step S3, the oxygen content in the anoxic zone is 0.1-0.3 mg / L; in step S4, the reflux unit device controls the sludge reflux ratio to be 70-80% and the nitrification liquor reflux ratio to be 95-100%.

[0030] Beneficial effects

[0031] Compared with the prior art, the present invention provides a rapid construction device and steps for continuous flow aerobic granular sludge using multi-fold (corrugated) plate flow control, which has the following beneficial effects:

[0032] By adjusting the spacing and angle of the internal turbulence-inducing components, the turbulence dissipation rate and vortex size are controlled, resulting in strong hydraulic shear forces generated inside the reactor under the combined action of air and water, which promotes rapid sludge granulation. After 20 days of operation, aerobic granular sludge was successfully cultivated with an average particle size of 300–500 μm, an SVI30 of 45–60 mL / g, and a settling velocity of 30–55 m / h. After 60–80 days of cultivation, the aerobic granular sludge had an average particle size of 500–1000 μm, an SVI30 of 35–40 mL / g, and a settling velocity of 50–80 m / h, exhibiting a dense structure and rounded shape.

[0033] The continuous flow multi-baffle plate reactor exhibits high pollutant removal efficiency. After 20 days of operation, the COD removal rate can reach over 95%. The removal rate can reach over 99%, with TN removal rates between 75% and 80% and TP removal rates between 60% and 65%. After 60-80 days of cultivation, the system is stable, achieving a COD removal rate of over 95%. The removal rate can reach over 99%, the removal rate of TN is between 80% and 85%, and the removal rate of TP is between 70% and 75%.

[0034] Most existing wastewater treatment plants use the activated sludge process, which has low pollutant removal efficiency, small flocs, poor sedimentation, large footprint, and an average power consumption of 0.29 kW·h / m³ for the blowers in the biological treatment tank. 3 This invention enables the rapid cultivation of aerobic granular sludge with low energy consumption, solving the problems of existing sewage treatment plants and reducing power consumption by 34%. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the continuous flow multi-flute (corrugated) plate reactor structure according to an embodiment of the present invention;

[0036] In the diagram, 1 is the inlet tank, 2 is the inlet pipe, 3 is the inlet pump, 4 is the gas flow meter, 5 is the aeration head, 6 is the valve, 7 is the turbulence component, 8 is the air compressor, 9 is the sludge suction pipe, 10 is the air inlet pipe, 11 is the vent valve, 12 is the air lifting tank, 13 is the exhaust pipe, 14 is the exhaust valve, 15 is the sludge return pipe, 16 is the outlet pump, 17 is the outlet pipe, 18 is the outlet tank, 19 is the sludge discharge valve, 20 is the sludge discharge pipe, 21 is the aeration pipe, 22 is the return pump, and 23 is the nitrification liquid return pipe. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] This embodiment is a continuous flow aerobic granular sludge device that utilizes multi-fold (corrugated) plate flow control. It can achieve rapid sludge granulation under continuous flow, with high pollutant removal rate and low energy consumption.

[0039] A method for rapid construction of continuous flow aerobic granular sludge using multi-fold (corrugated) plate flow pattern control:

[0040] The reactor has a total effective volume of 14L, an influent flow rate Q = 48L / d, an influent COD of 0.35g / L, and a volumetric loading rate of 1.2gCOD / (L·d). The hydraulic retention time is 2.5h in the anoxic zone, 4h in the aerobic zone, and 0.5h in the sedimentation zone. The effective volume is 5L in the anoxic zone, 8L in the aerobic zone, and 1L in the sedimentation zone. The volumetric loading rate is 3.36gCOD / (L·d) in the anoxic zone and 2.1gCOD / (L·d) in the aerobic zone. The reactor's effective height is 25cm, effective width is 10cm, and effective length is 56cm. According to the formula... In the anoxic zone, a value of 0.9 is used, so the number of corrugated (wave) plates (x) is approximately 4. The hydraulic shear force required in the aerobic zone decreases from strong to weak; therefore, a value of 0.5 is used at the front and 0.8 at the rear. This results in approximately 5 turbulence-inducing components at the front and 3 at the rear. Adding the wall separating the anoxic and aerobic zones, the final bioreactor zone has a total of 13 turbulence-inducing components. The distance between the central axes of two turbulence-inducing components is d. The control ratio h / d for a single corridor in the anoxic zone is 5–10, and h / d is taken as 6.25 in the anoxic zone, resulting in a 4cm distance between the two partitions. In the aerobic zone, the control ratio h / d for a single corridor is 2–10. The hydraulic shear force required in the aerobic zone decreases from strong to weak; therefore, a value of 0.5 is used. The aerobic zone has a front h / d ratio of 8.33 and a rear h / d ratio of 6.25. Therefore, the distance between the central axes of the two turbulence-inducing components at the front of the aerobic zone is 3 cm, and the distance between the central axes of the two turbulence-inducing components at the rear is 4 cm. The aerobic zone has 4 corrugated plates, 3 corrugated plates, and 2 straight plates. In this embodiment, the corrugated plate angle is 90 degrees. The height of the turbulence-inducing components in both the anoxic and aerobic zones accounts for 70% of the reactor's filling ratio. The turbulence-inducing components are made of stainless steel. By adjusting the aeration valve opening, the dissolved oxygen content in the anoxic zone is maintained at approximately 0.2 mg / L. The apparent gas velocity q in each compartment of the aerobic zone is 0.6 cm / s. Calculating the cross-sectional area A cm² of the compartment, the aeration rate of each compartment in the aerobic zone is... The unit is L / min, and the aeration rate is controlled by adjusting the gas flow meter.

[0041] Operation mode of continuous flow multi-baffle (corrugated) plate reactor for rapid cultivation of aerobic granular sludge:

[0042] Step 1: Inoculate the reactor with activated sludge, with an inoculation amount of approximately 3000 mg / L; the influent water quality is approximately: COD 350 mg, NH4+-N 25 mg, TP 3 mg and a certain amount of trace element solution per liter of synthetic wastewater;

[0043] Step 2: Turn on the inlet pump to send the wastewater in the inlet tank into the reactor; the inlet water temperature is about 25 degrees Celsius, and the pH value is 7.5-8.5.

[0044] Step 3: Turn on the air compressor and valves to send gas into the reactor through the aeration head. Control the opening of the aeration valve to make the dissolved oxygen content in the anoxic zone about 0.2 mg / L. Control the gas flow meter to make the aeration rate in the aerobic zone meet the calculated requirements.

[0045] Step 4: Turn on the sludge return unit and the nitrification liquor return unit to return the sludge from the bottom of the sedimentation tank to the biological reactor and return the mixed liquor from the aerobic zone to the anoxic zone. Adjust the return unit to control the sludge return ratio to 80% and the nitrification liquor return ratio to 100%.

[0046] Step 5: Turn on the effluent pump to allow the supernatant from the sedimentation tank to flow out;

[0047] Step 6: Control the sludge age at 25 days.

[0048] Continuous flow multi-flute (corrugated) plate reactors promote the rapid formation of aerobic granular sludge. After 20 days of cultivation, the average particle size reaches 300–500 μm, SVI30 reaches 45–60 mL / g, the settling velocity is 30–55 m / h, and the COD removal rate is approximately 95%. The removal rate can reach over 99%, with TN removal rates between 75% and 80% and TP removal rates between 60% and 65%. After 60-80 days of cultivation, the average particle size of the aerobic granular sludge reaches 500-1000 μm, SVI30 reaches 35-40 mL / g, the settling velocity is 50-80 m / h, and the COD removal rate can reach over 95%. The removal rate can reach over 99%, with a removal rate of 80% to 85% for TN and 70% to 75% for TP; it also reduces power consumption by 34%.

[0049] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A device for rapid construction of continuous flow aerobic granular sludge using multi-fold (corrugated) plate flow pattern control, characterized in that, The constructed device is achieved through the following components: the reactor includes an inlet unit, a turbulence-inducing component, an aeration unit, a sludge return unit, a nitrification liquor return unit, an effluent unit, and a sludge discharge unit; the turbulence-inducing component includes straight plates, corrugated plates with varying degrees of undulation, and corrugated plates with the same undulation; the turbulence-inducing component occupies 30-100% of the reactor's filling ratio in the anoxic and aerobic zones; the corrugated plate's folding angle θ is controlled at 80-120 degrees; the distance between the central axes of the two corrugated plates is d, and the single-channel h / d ratio is controlled at 2-10; the minimum vortex size is 50-500 mm, and the maximum vortex size is 300-1500 mm; the turbulent dissipation rate in each zone is controlled at 0.03-0.35 m. 2 / s 3 ; The corrugated plates account for 30-40% of the total number of aerobic zone turbulence components, the same corrugated plates account for 40-50% of the total number of aerobic zone turbulence components, and the straight plates account for 10-30% of the total number of aerobic zone turbulence components.

2. The device for rapid construction of continuous flow aerobic granular sludge using multi-fold (corrugated) plate flow control according to claim 1, characterized in that, The reactor influent flow direction is sequentially from the anoxic zone to the aerobic zone and then to the sedimentation zone; the reactor influent flow velocity is 0.20-0.50 m / s; the reactor BOD sludge loading is 0.13-0.2 kgBOD5 / kg MLSS·d; and the denitrification rate in the anoxic zone is 0.03-0.06 kgNO. - 3-N / kg MLSS·d; denitrification nitrogen removal rate is 0.044-0.088 kg NO - 3-N / kg MLSS·d; the denitrification rate in the aerobic zone is 0.09-0.15 kgNH. + 4-N / kg MLSS·d; the gas-to-water ratio of the reactor is (2.5-3.5):(0.5-1.5); the dissolved oxygen content in the anoxic zone is 0.1-0.30 mg / L; the apparent gas velocity q in the aerobic zone is 0.5-1.2 cm / s; the sludge return ratio is 60-80%, the nitrification liquor return ratio is 100-150%, and the sludge age is 15-25 days.

3. The device for rapid construction of continuous flow aerobic granular sludge using multi-fold (corrugated) plate flow control according to claim 2, characterized in that, The hydraulic retention time in the anoxic zone of the reactor is 0.5-3 hours, the hydraulic retention time in the aerobic zone is 1-4 hours, and the sedimentation time in the sedimentation zone is 10-60 minutes.

4. The device for rapid construction of continuous flow aerobic granular sludge using multi-fold (corrugated) plate flow control according to claim 1, characterized in that, The controlled single-channel h / d ratio is 2-10; the minimum vortex size of the corrugated plates is 50-500 mm, and the maximum vortex size is 500-1500 mm; the minimum vortex size of the same corrugated plates is 100-500 mm, and the maximum vortex size is 500-1500 mm; the controlled aerobic zone turbulent dissipation rate is 0.03-0.08 m. 2 / s 3 The turbulent dissipation rate in the anoxic zone was controlled to be 0.15-0.35 m. 2 / s 3 .

5. The device for rapid construction of continuous flow aerobic granular sludge using multi-fold (corrugated) plate flow control according to claim 1, characterized in that, Continuous flow multi-flute (corrugated) plate reactors promote the cultivation of aerobic granular sludge for 15-25 days, with an average particle size of 300-500 μm and SVI. 30 The concentration is 45-60 mL / g, and the settling velocity is 30-55 m / h.

6. The operating steps of a continuous flow aerobic granular sludge rapid construction device using multi-fold (corrugated) plate flow control as described in any one of claims 1-5, characterized in that, Includes the following steps: S1: The reactor is inoculated with activated sludge; S2: Turn on the inlet pump to send the wastewater in the inlet tank into the reactor; S3: Turn on the air compressor and valves to send air into the reactor through the aeration head, and control the dissolved oxygen content in the anoxic zone by controlling the opening of the aeration valve. S4: Activate the sludge return unit and the nitrification liquor return unit to return the sludge from the bottom of the sedimentation tank to the biological reactor and return the mixed liquor from the aerobic zone to the anoxic zone. Adjust the return unit device to control the sludge return ratio and the nitrification liquor return ratio. S5: Turn on the effluent pump to allow the supernatant from the sedimentation tank to flow out; S6: Sludge age should be controlled at 15-25 days.

7. The operating steps of the continuous flow aerobic granular sludge rapid construction device using multi-fold (corrugated) plate flow control according to claim 6, characterized in that, In step S1, the amount of inoculated sludge is 2500-3500 mg / L; in step S2, the influent temperature is 20-30℃ and the pH value is 7.5-8.5; in step S3, the oxygen content in the anoxic zone is 0.1-0.3 mg / L; in step S4, the reflux unit device controls the sludge reflux ratio to be 60-80% and the nitrification liquor reflux ratio to be 100-150%.

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