CN114988564B - Pressure-driven cyclone reinforced continuous flow aerobic activated sludge granulation device and method - Google Patents

Abstract

The invention provides a pressure-driven cyclone reinforced continuous flow aerobic activated sludge granulation device and a method, which relate to the technical field of sewage treatment and comprise the following steps: the fluidized bed activation system comprises a fluidized bed activation reactor group, a secondary sedimentation tank, a reservoir, an external cyclone activation separator, a controller, a pressure sensor and an overflow variable frequency pump; the fluidized bed activation reactor group comprises a plurality of fluidized bed activation reactors connected in series, each fluidized bed activation reactor is internally provided with a built-in cyclone activator, and each cyclone activator is internally provided with a cyclone guide plate; the overflow pipe is connected with the overflow pipe, the overflow port of the separator is connected with the overflow pipe, the three pressure sensors are respectively used for monitoring the pressure in the inlet of the separator, the overflow pipe and the underflow pipe, the pump inlet of the overflow variable frequency pump is communicated with the overflow pipe, and the controller can control the pumping flow rate of the overflow variable frequency pump. The pressure-driven cyclone reinforced continuous flow aerobic activated sludge granulation device and the method provided by the invention can activate activated sludge in the continuous flow granulation process.

Description

Pressure-driven cyclone reinforced continuous flow aerobic activated sludge granulation device and method

Technical Field

The invention relates to the technical field of sewage treatment, in particular to a pressure-driven cyclone reinforced continuous flow aerobic activated sludge granulation device and method.

Background

Aerobic sludge granular sludge has many advantages over conventional activated sludge, such as high biological retention, easy sludge-water separation, capability of generating various biological processes in a granular structure, impact load resistance, etc., which makes aerobic sludge granulation a promising technology in terms of domestic and industrial wastewater treatment.

The activated aerobic granular sludge should have the condition of aerobic sludge granulation so as to ensure long-term stable operation of the aerobic granular sludge. At present, most of aerobic granular sludge is cultivated in a sequencing batch reactor, and factors for promoting granulation of aerobic activated sludge in the sequencing batch reactor mainly comprise: selective pressure based on settling velocity, nutrient rich-lean periodic alternating environment, hydraulic shear force, organic loading rate, feed water composition and dissolved oxygen. Among them, the selective pressure (microorganism population changing pressure) based on the sedimentation velocity plays a decisive role in sludge granulation.

Compared with a sequencing batch reactor, the continuous flow aerobic granular sludge reactor has a plurality of advantages. Research shows that factors for promoting the granulation of the aerobic activated sludge in the continuous flow reactor are mainly as follows: selective pressure based on settling velocity, granular sludge circulation system, nutrient rich-lean periodic alternating environment, hydraulic shear force, added organisms (e.g., inoculated aerobic granular sludge produced in a sequencing batch reactor or inoculated biofilm), ambient temperature, dissolved oxygen, and the like. Among these, selective pressure, rich-lean environments and hydraulic shear forces based on settling velocity are particularly important. The reason is that: the selective pressure based on the sedimentation velocity plays a decisive role in the granulation of the aerobic sludge in the continuous flow reactor, but the existing sludge sedimentation velocity selector is mainly based on the gravity sedimentation principle, is easy to be interfered by continuous flow, has long separation time, large occupied area, high cost and complex structure, and is difficult to regulate and control to optimize the sedimentation velocity; the fully mixed continuous flow reactor commonly used is not beneficial to creating a rich-lean periodic alternating environment; suitable hydraulic shear forces promote biofilm formation, enhancing sludge granulation, but existing continuous flow reactors are based essentially on gravity sedimentation principles, in which a hydraulic shear force field of suitable strength is lacking. Of particular note is: the intensity of the selective pressure based on the sedimentation velocity is preferably quantitatively, flexibly and stably regulated and controlled to optimize the sedimentation velocity of the sludge; the intensity of the hydraulic shearing force is also preferably quantitatively, flexibly and stably controlled, because the excessive hydraulic shearing force can crush the granular sludge.

Recently, researchers have successfully cultured aerobic granular sludge in a continuous flow reactor with flocculent activated sludge in real domestic sewage using three factors of selective pressure based on sedimentation velocity, granular sludge circulation system and rich-lean nutrient cycle alternating environment: sorting sludge by a sludge sedimentation velocity selector based on the gravity sedimentation principle, and optimizing the sludge sedimentation velocity by adjusting the water outlet height; a plug flow reactor with an electric stirrer in series is used to create spatially a rich-lean periodic alternating environment. This study is currently the best one because it breaks through some of the limitations of the traditional continuous flow aerobic sludge granulation technology.

However, the inventor finds that the aerobic granular sludge which can run for a long time has small effective porosity, few mass transfer channels and low activity whether the reactor is a sequencing batch reactor or a continuous flow reactor. This causes that the internal cells of the aerobic granular sludge are easy to autolyze to form a cavity, so that the sludge is unstable and easy to break, and the larger the grain size is, the more serious the situation is, and the reason is known as follows: the existing reactors are basically based on the gravity sedimentation principle, and lack of enough hydraulic shear force fields in the reactors, so that granular sludge cannot effectively rotate, and further cannot effectively drive micro-interface oscillation of the granular sludge, and transfer of substrates and nutrient substances in sludge pore channels and diffusion of dissolved oxygen are limited. In addition, the lower hydraulic shear force inhibits the secretion of extracellular polymers playing an important role in stably maintaining aerobic granular sludge, reduces the hydrophobicity of the cell surface, cannot effectively cut off the filamentous bacteria growing rapidly on the particle surface in time, and reduces the density and sphericity of the particles.

Therefore, there is a need to develop a new solution to the above-mentioned problems.

Disclosure of Invention

The invention aims to provide a pressure-driven rotational flow reinforced continuous flow aerobic activated sludge granulation device and a pressure-driven rotational flow reinforced continuous flow aerobic activated sludge granulation method, so as to solve the problems in the prior art and enable activated sludge to be activated in the continuous flow granulation process.

In order to achieve the above object, the present invention provides the following solutions:

the invention provides a pressure-driven rotational flow reinforced continuous flow aerobic activated sludge granulation device, which comprises: the fluidized bed activation reactor comprises a fluidized bed activation reactor group, a secondary sedimentation tank, a water reservoir, a separator, a controller, a pressure sensor and an overflow variable frequency pump; the fluidized bed activation reactor group comprises a plurality of fluidized bed activation reactors connected in series, a built-in cyclone activator is arranged in each fluidized bed activation reactor, and a cyclone guide plate is arranged in each cyclone activator; the separator is provided with a separator inlet, a separator underflow opening and a separator overflow opening, and a cyclone guide plate is arranged in the separator; the boiling bed activation reactor group is provided with a water inlet, a water outlet and a reflux port, the water outlet of the boiling bed activation reactor group is communicated with the secondary sedimentation tank, the bottom flow of the secondary sedimentation tank is led into a reservoir, the bottom outlet of the reservoir is provided with two reflux branches, one reflux branch is directly connected with the reflux port of the boiling bed activation reactor, the other reflux branch is communicated with the inlet of the separator, the bottom flow port of the separator is communicated with the reflux port, and a timing electromagnetic valve is arranged in each reflux branch; the overflow pipe is connected with the overflow pipe, the overflow port of the separator is connected with the overflow pipe, the three pressure sensors are respectively used for monitoring the pressure in the inlet of the separator, the overflow pipe and the underflow pipe, the pump inlet of the overflow variable frequency pump is communicated with the overflow pipe, and the controller can control the pumping flow rate of the overflow variable frequency pump.

In one embodiment, the water outlet of the ebullated bed activation reactor set is communicated with the inlet of the separator through a pipeline, a gas-liquid mixing pump and a liquid flowmeter are arranged on the pipeline, the gas-liquid mixing pump can suck air while transporting liquid, and the gas-liquid mixing pump can mix the mud-water mixture and the air in the ebullated bed activation reactor in the gas-liquid mixing pump and then convey the mixture into the separator.

In one embodiment, the bottom opening of the built-in cyclone activator is also connected with a underflow pipe, and the underflow pipe adopts a stepped design, so that the centrifugal force can be reduced, and the possibility that particles are sheared by hydraulic shearing force is further reduced.

In one embodiment, the housing of the built-in cyclone activator and the housing of the classifier each comprise a cylindrical section and a conical section, the cylindrical section being located directly above the conical section and both being coaxially disposed.

In one embodiment, the middle of the cylindrical section is concave inward and the middle of the conical section is convex outward.

In one embodiment, the inner wall of the conical section and the inner surface of the underflow pipe are both processed by hydrophobic materials, and the inner wall of the cylindrical section and the inner surface of the overflow pipe are both processed by hydrophilic materials, so that the separation effect of the granular sludge and the water can be enhanced.

In one embodiment, the overflow variable frequency pump further comprises a frequency converter, and the controller regulates the pumping flow rate of the overflow variable frequency pump through the frequency converter.

In one embodiment, the apparatus further comprises aeration means for aerating at the bottom of each of the ebullated bed activation reactors;

the aeration device comprises a gas generating device, gas pipes, a gas flowmeter and a plurality of air diffusers, wherein the air diffusers are microporous air diffusers or disc-type membrane microporous aerators, the gas pipes are uniformly distributed at the bottom of each ebullated bed activation reactor, the gas generating device can aerate the gas pipes, the air diffusers are arranged in each ebullated bed activation reactor, the gas inlets of the air diffusers are communicated with the gas pipes, and the gas flowmeter is used for monitoring the aeration amount of the gas generating device;

the gas generating device is a micro-nano bubble generating device.

In one embodiment, the conical section of the separator is provided with an annular air diffuser, the annular air diffuser is connected with a micro-nano bubble generating device, and the principles of air floatation reinforced cyclone separation are utilized to reinforce mud-water separation and separation of activated sludge and granular sludge.

The invention also provides a continuous flow aerobic granular sludge activated cyclone strengthening method which is realized by using the pressure-driven cyclone strengthening continuous flow aerobic activated sludge granulation device; comprising the following steps:

the pressure drop ratio of the separator is in the range of 110-120% by regulating the flow rate of the overflow variable frequency pump, wherein the pressure drop ratio is the ratio of the pressure difference between the inlet of the separator and the overflow pipe orifice of the separator and the pressure difference between the inlet of the separator and the underflow pipe orifice of the separator;

in one embodiment, the method further comprises controlling the opening and closing of each reflux branch through a timing electromagnetic valve;

the timing electromagnetic valve on the return branch between the bottom outlet of the reservoir and the inlet of the separator is a timing electromagnetic valve I, and the other timing electromagnetic valve II;

when the first timing electromagnetic valve is opened within a set time, the second timing electromagnetic valve is set to be in a closed state, and water discharged from the reservoir enters an external cyclone activator at the moment, so that sludge separated by the separator is returned;

when the first timing electromagnetic valve is closed within a set time, the second timing electromagnetic valve is set to be in an open state, and water discharged from the reservoir flows back to the ebullated bed activation reactor at the moment;

the second timing electromagnetic valve can be closed according to actual demands, so that the whole process is switched to a process that all the effluent of the reservoir enters the external cyclone activator.

The secondary sedimentation tank and the reservoir can be added or removed according to actual requirements in different reaction stages.

Compared with the prior art, the invention has the following technical effects:

1. according to the pressure-driven cyclone reinforced continuous flow aerobic activated sludge granulation device and method provided by the invention, the pressure drop ratio of the cyclone found by the inventor is utilized to realize the regulation and control on the separation performance of the cyclone and the rotation speed of the granular sludge in the cyclone field by virtue of the efficient regulation and control effect of the rotation of the granules in the cyclone field, so that the real-time quantitative monitoring on the activation and separation of the continuous flow aerobic granular sludge is realized;

2. the multistage series-connected ebullated bed activation reactor provides a eutrophication-lean nutrition period alternating condition, is beneficial to the growth of strains with strong storage capacity, can inhibit excessive propagation of filamentous bacteria, and further creates conditions for the formation and stability of aerobic granular sludge;

3. the built-in cyclone activator utilizes a cyclone guide plate to generate cyclone, plays a role in activating granular sludge, the running power of the built-in cyclone activator and the power of mud water internal circulation in the fluidized bed activation reactor are the total density difference of mud-water-gas mixed liquid inside and outside the built-in cyclone activator, particles in a cyclone field have high-speed autorotation, and the particle autorotation can drive a particle micro-interface to oscillate so as to realize pollutant desorption;

4. the cyclone activator and the bottom flow pipe of the separator are arranged in a stepped design, so that the centrifugal force can be reduced, and the possibility that particles are sheared by hydraulic shearing force is further reduced;

5. the wall surface of the cylindrical section of the built-in cyclone activator and the separator is designed to be a concave surface, and the conical section is designed to be a convex surface, so that the separation efficiency can be improved while the pressure drop is reduced;

6. the built-in cyclone activator and the classifier are combined by adopting hydrophilic materials and hydrophobic materials, so that the separation effect of the granular sludge and water can be enhanced;

7. the cyclone guide plate in the separator plays a role in improving the separation efficiency;

8. the structure design is ingenious, the internal and external circulation function is realized, the mass transfer effect is excellent, and the load impact resistance is strong;

9. providing sufficient hydraulic shear force (the swirling flow field is a hydraulic shear flow field);

10. the micro-nano bubbles generated by the micro-nano bubble generating device can prolong the residence time of the bubbles in water, improve the dissolution efficiency of gas in water and strengthen the separation of sludge and water;

11. the gas-liquid mixing pump can absorb air while transporting liquid, and the air and sludge-water mixture is mixed in the gas-liquid mixing pump and then is conveyed to the separator, so that the principle of air floatation reinforced cyclone separation is utilized, and on the premise of avoiding shearing sludge by a water force field, the sludge-water separation and the separation of activated sludge and granular sludge are reinforced;

12. the separator is internally provided with an annular air diffuser which is connected with the micro-nano bubble generating device, and the principle of air floatation reinforced cyclone separation is utilized to reinforce mud-water separation and the separation of activated sludge and granular sludge.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a pressure-driven cyclone-enhanced continuous-flow aerobic activated sludge granulation device according to the first embodiment;

fig. 2 is a schematic structural diagram of a pressure-driven cyclone-reinforced continuous-flow aerobic activated sludge granulation device provided in the second embodiment;

in the figure: 1. a water inlet pump; 2. a first liquid flowmeter; 3. a water inlet of the fluidized bed activation reactor; 4. activating the reactor by a boiling bed; 5. a cyclone activator is arranged in the reactor; 6. a first cyclone guide plate; 7. a cylindrical section of the cyclone activator is arranged in the cylinder section; 8. a conical section of the cyclone activator is arranged in the inner part; 9. a cyclone activator bottom flow pipe is arranged in the cyclone activator bottom flow pipe; 10. a gas generating device; 11. a gas flow meter; 12. a microporous air diffuser; 13. a secondary sedimentation tank; 14. a secondary sedimentation tank overflow weir water outlet; 15. a secondary sedimentation tank bottom flow port; 16. a reservoir; 17. a first timing electromagnetic valve; 18. a gas-liquid mixing pump; 19. a second liquid flowmeter; 20. a first pressure sensor; 21. a classifier inlet; 22. a sorter; 23. a second cyclone guide plate; 24. a classifier cylindrical section; 25. a classifier cone section; 26. an overflow pipe of the separator; 27. a separator underflow pipe; 28. a second pressure sensor; 29. an overflow variable frequency pump; 30. a frequency converter; 31. a controller; 32. a third pressure sensor; 33. a pipeline regulating valve; 34. activating a reactor reflux port by the boiling bed; 35. a timing electromagnetic valve II; 36. a sludge reflux pump; 37. an annular air diffuser; 38. disc type membrane microporous aerator.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The invention aims to provide a pressure-driven rotational flow reinforced continuous flow aerobic activated sludge granulation device and a pressure-driven rotational flow reinforced continuous flow aerobic activated sludge granulation method, so as to solve the problems in the prior art and enable activated sludge to be activated in the continuous flow granulation process.

In order that the above-recited objects, features and advantages of the present invention will become more readily apparent, a more particular description of the invention will be rendered by reference to the appended drawings and appended detailed description.

Example 1

The embodiment provides a pressure-driven cyclone reinforced continuous flow aerobic activated sludge granulation device, as shown in fig. 1, which comprises: the fluidized bed activation reactor group, the secondary sedimentation tank 13, the water reservoir 16, the separator 22, the controller 31, the overflow variable frequency pump 29 and three pressure sensors (a first pressure sensor 20, a second pressure sensor 28 and a third pressure sensor 32);

the multistage series-connected ebullated bed activation reactors 4 form a ebullated bed activation reactor group so as to realize the space lean-rich nutrition alternation, thereby replacing the time lean-rich nutrition alternation in the sequencing batch reactor, promoting the granulation of flocculent activated sludge and further removing organic matters and ammonia nitrogen in the inlet water under the action of aerobic granular sludge. Each ebullated bed activation reactor is internally provided with a built-in cyclone activator 5 which is vertically arranged, the bottom is provided with a structure for aeration, the ebullated bed activation reactor is also provided with a reflux port, a water inlet and a water outlet, wherein the built-in cyclone activator 5 comprises a through cavity which is opened up and down and a cyclone guide plate I6 which is arranged in the through cavity, sludge in the ebullated bed activation reactor 4 flows into the built-in cyclone activator through the upper opening of the built-in cyclone activator 4 and then flows downwards along the cyclone guide plate I6 to a built-in cyclone activator underflow pipe 9, and compared with other prior art, the electric stirrer is used, the built-in cyclone activator 5 does not need electric energy. The aeration device comprises a gas generating device 10, a gas flowmeter 11 and a hole air diffuser 12 arranged at the bottom of each ebullated bed activation reactor 4, wherein the hole air diffuser 12 is connected with the gas generating device 10 through a pipeline, and the hole air diffuser 12 is reasonably arranged to uniformly mix mud, water and gas without influencing the outflow of the mud from the outlet at the bottom of the ebullated bed activation reactor 4. The end of the ebullated bed activation reactor group is connected with a secondary sedimentation tank 13.

The secondary sedimentation tank 13 has the functions of separating mud from water, settling and concentrating the sludge, and the supernatant (effluent) flows out from the secondary sedimentation tank overflow weir water outlet 14, so that a great amount of sludge loss caused by poor sludge settling can be avoided. Because the secondary sedimentation tank 14 cannot separate flocculent sludge and granular sludge, the secondary sedimentation tank 14 and the separator 22 are used in combination, so that the effluent can be clarified and the flocculent sludge and the granular sludge can be separated. And a reservoir 16 is additionally arranged behind the secondary sedimentation tank bottom flow port 15 for the stable operation of the whole process.

The bottom outlet of the reservoir 16 is provided with two reflux branches, one branch is directly connected with a reflux port 34 of the ebullated bed activation reactor, the branch is provided with a second timing battery valve 36, the other branch is connected with the reflux port 34 of the ebullated bed activation reactor through a separator 22, and a first timing battery valve 17 is arranged between the secondary sedimentation tank reflux port 16 and the separator 21. Each branch is controlled by a timing solenoid valve.

The classifier 22 includes a classifier inlet 21, a classifier underflow pipe 27, and a classifier overflow pipe 26, and the water inlet of the classifier 22 is controlled by a first timing solenoid valve 17, a gas-liquid mixing pump 18, and a second liquid flow meter 19. The first pressure sensor 20, the second pressure sensor 28 and the third pressure sensor 32 are respectively used for monitoring the pressures of the separator inlet 21, the overflow pipe 26 and the underflow pipe 27 in real time. The pump inlet of the overflow variable frequency pump 29 is communicated with the overflow pipe 26 of the separator, three pressure sensors are respectively in communication connection with the overflow variable frequency pump 29 and are all in communication connection with the controller 30, the three pressure sensors can transmit the monitored pressure values to the controller 30, and the controller 31 can control the pumping flow rate of the overflow variable frequency pump 29; the pressure drop ratio of the separator 22 is in the range of 110-120% by regulating the flow rate of the overflow variable frequency pump 29, wherein the pressure drop ratio is the ratio of the pressure difference between the separator inlet 21 and the separator overflow pipe 26 to the pressure difference between the separator inlet 21 and the separator underflow pipe 27;

when the first timing solenoid valve 17 is opened within a set time, the second timing solenoid valve 19 is set to be in a closed state, and at the moment, the sludge in the reservoir 16 enters the classifier 22, the flocculent sludge with smaller density is discharged from the overflow pipe 26 of the classifier, and the flocculent sludge and the granular sludge with larger density flow out from the underflow pipe 27 of the classifier and then flow back to the reflux port 34 of the ebullated bed activation reactor; when the first timing electromagnetic valve 17 is closed in a set time, the second timing electromagnetic valve 19 is set to be in an open state, and at the moment, the sludge in the reservoir 16 directly flows back to the reflux port 34 of the ebullated bed activation reactor, and the reflux quantity can be regulated through the sludge reflux pump 36; the first timing solenoid valve 17 can be closed according to actual requirements, so that the whole process is switched to a process that all sludge in the reservoir 16 enters the classifier 22.

The pressure-driven cyclone reinforced continuous flow aerobic activated sludge granulation device provided by the embodiment realizes the regulation and control of the cyclone separation performance and the particle sludge rotation speed in the cyclone field by utilizing the high-efficiency regulation and control effect of cyclone pressure drop comparison and cyclone separation and cyclone field particle rotation found by the inventor, further realizes the real-time quantitative monitoring of continuous flow aerobic particle sludge activation and separation, and ensures that the particle sludge formed in the fluidized bed activation reactor group and the separator 22 has strong impact load resistance, stable operation, high dissolved oxygen utilization rate and enough hydraulic shear force to maintain granulation.

Further, the ebullated bed activation reactor set further includes an aeration device, the pipeline in the aeration device is an air pipe, the gas generating device 10 can blow air into the air pipe, the air inlet of the microporous air diffuser 12 is communicated with the air pipe, and the gas flowmeter is used for monitoring the aeration amount of the gas generating device 10. When in aeration, air is mixed with sludge and water in the fluidized bed activation reactor, air bubbles are combined with activated sludge flocs and aerobic granular sludge, the sludge is brought to the liquid level by the air bubbles due to density difference, the aerobic granular sludge is left at the bottom, and part of the sludge enters the built-in cyclone activator 5 for cyclone activation in the aeration process so as to promote the formation of the granular sludge.

Further, the microporous air diffusers 12 in each fluidized bed activation reactor 4 are reasonably arranged to prevent the bottom outlet of the built-in cyclone activator 5 from being disturbed by bubbles, the microporous air diffusers 12 are uniformly arranged at the bottom of the fluidized bed activation reactor 4 in a circular ring shape, the inner diameter of the circular ring is larger than the diameter of the built-in cyclone activator underflow pipe 9, and the outer diameter of the circular ring is slightly smaller than the diameter of the fluidized bed activation reactor 4, namely, bubbles generated by the microporous air diffusers 7 do not pass through the built-in cyclone activator underflow pipe 9 in the ascending process, so that the inside circulation is generated in each fluidized bed activation reactor 4.

Further, a frequency converter 30 is also included, and a controller 31 regulates the pumping flow rate of the overflow variable frequency pump 29 through the frequency converter 30.

Further, a second cyclone guide plate 23 is provided in the separator 22.

Further, the outlet of the reservoir 16 is communicated with the inlet 21 of the separator through a pipeline, and a first timing electromagnetic valve 17, a gas-liquid mixing pump 18, a second liquid flowmeter 19 and a first pressure sensor 20 are arranged on the pipeline, and the gas-liquid mixing pump 18 can convey sludge in the reservoir into the separator 22.

Further, a water inlet pipe is communicated with a water inlet 3 of the activation reactor of the rising bed, and a water inlet pump 1 and a liquid flowmeter 2 are arranged on the water inlet pipe.

Further, a cyclone guide plate is arranged in the separator 22, so that the separation efficiency is improved.

When the pressure-driven cyclone reinforced continuous flow aerobic activated sludge granulation device provided by the embodiment is put into use, a proper amount of pretreated sludge is firstly added into a fluidized bed activation reactor group, the water inlet pump 1 conveys primary treatment effluent of a sewage treatment plant to the fluidized bed activation reactor 4, and sludge-water-gas mixing occurs under the action of the gas generating device 10 and the microporous air diffuser 12. The bubbles are combined with activated sludge flocs and aerobic granular sludge, and the sludge is brought to the liquid level by the bubbles due to the existence of density difference. In the aeration process, part of sludge enters a built-in cyclone activator 5, and cyclone is generated under the action of a cyclone guide plate 5 and gravity so that the sludge moves downwards in a spiral way, when the sludge is settled to the bottom of a fluidized bed activation reactor 4, part of sludge continues to circulate in the fluidized bed activation reactor 4, and the other part of sludge enters the next-stage fluidized bed activation reactor from the water outlet of the fluidized bed activation reactor 4, so that a new activation cycle is started. And then sequentially enters other ebullated bed activation reactors, which not only activates the sludge but also provides rich-lean nutrient cycle alternation for the whole system. The water outlet of the boiling bed activation reactor at the tail end is connected with the secondary sedimentation tank 13, the supernatant (effluent) flows out from the overflow weir water outlet 14 of the secondary sedimentation tank, and the settled and concentrated sludge flows into the reservoir 16 from the secondary sedimentation tank bottom flow port 15. The two return branches of the outlet of the reservoir 16 are controlled by means of a timed solenoid valve. The first 17 on time of the timing solenoid valve was set to 15s/5min (i.e., 15 seconds every 5 minutes) before significant granular sludge was found, and then the first 17 on time of the timing solenoid valve was set to 25s/5min. In order to avoid excessive sludge accumulation in the secondary sedimentation tank 13 when the first timing electromagnetic valve 17 is closed, the second timing electromagnetic valve 35 is set to be opened when the first timing electromagnetic valve 17 is closed, namely, the opening time of the second timing electromagnetic valve 35 in two stages is set to be 4min45s/5min and 4min 35s/5min respectively. When the first timing solenoid valve 17 is opened, the sludge in the reservoir 16 enters the classifier 22 tangentially under the action of the gas-liquid mixing pump 18 to be classified, the flocculent sludge with smaller density is discharged from the classifier overflow pipe 26, the flocculent sludge with larger density and the granular sludge are discharged from the classifier underflow pipe 27, and then the sludge discharged from the classifier underflow pipe 27 is returned to the fluidized bed activation reactor return port 34. When the second timing solenoid valve 36 is opened, the sludge in the reservoir 16 is returned to the ebullated bed activation reactor return port 34. The first pressure sensor 20, the second pressure sensor 28 and the third pressure sensor 32 are respectively used for monitoring the pressures of the separator inlet 21, the overflow pipe 26 and the underflow pipe 27 in real time. The pump inlet of overflow variable frequency pump 29 communicates with separator overflow pipe 26, and three pressure sensor respectively with overflow variable frequency pump 29 all with controller 30 communication connection, three pressure sensor can be with the pressure value transmission that monitors in controller 30, controller 31 can control the pump-out velocity of flow of overflow variable frequency pump 29. The controller 31 regulates and controls the overflow variable frequency pump 29 in real time through the frequency converter 30 according to the change of the pressure drop ratio (namely the ratio of the pressure difference between the separator inlet 21 and the overflow pipe 26 and the pressure difference between the separator inlet 21 and the underflow pipe 27) of the separator 22 measured by the pressure sensor I20, the pressure sensor II 28 and the pressure sensor III 32, so as to regulate and control the separation performance of the separator 22 and the autorotation characteristic of particles therein, namely to realize the real-time quantitative monitoring of the continuous flow aerobic particle sludge activity enhancement.

Example two

The embodiment provides another pressure-driven cyclone reinforced continuous flow aerobic activated sludge granulation device, which is different from the device used in the first embodiment, as shown in fig. 2, the wall surface of the cylindrical section 7 of the built-in cyclone activator is a concave surface, the wall surface of the conical section 8 is a convex surface, the wall surface of the cylindrical section 23 of the separator is a concave surface, and the wall surface of the conical section 24 is a convex surface, so that the pressure drop is reduced, and meanwhile, the separation efficiency is improved. The separator 22 is provided with an annular air diffuser 37, the annular air diffuser 37 is connected with the micro-nano bubble generating device 10, and the principles of air floatation reinforced cyclone separation are utilized to reinforce mud-water separation and separation of activated sludge and granular sludge.

Example III

The embodiment provides a pressure-driven cyclone reinforced continuous flow aerobic activated sludge granulation device and a method, which are realized by using the device shown in figure 2; comprising the following steps: the pressure drop ratio of the classifier 22, which is the ratio of the pressure difference of the classifier inlet 21 to the overflow pipe 26 and the pressure difference of the classifier inlet 21 to the underflow pipe 27, is in the range of 110 to 120% by regulating the flow rate of the overflow variable frequency pump 29.

The invention will be further described with reference to the accompanying drawings and examples of its application.

Application examples:

in this embodiment, a hydrocyclone with a diameter of a cylindrical section (also called a "cyclone diameter") of 160mm is used as the classifier 22, and a second cyclone guide 25 is provided in the classifier 22. The method comprises the steps of starting an aerobic granular sludge process by taking reflux sludge of a secondary sedimentation tank of a sewage treatment plant as inoculated sludge, treating the sludge before inoculation, firstly intercepting and removing larger impurities mixed in the inoculated activated sludge by using a 80-mesh screen, then performing stuffy exposure treatment on the sludge for 48 hours to recover the activity of microorganisms in the sludge, finally adding a proper amount of sludge subjected to the stuffy exposure treatment into each ebulled bed activation reactor, and adding water to enable the concentration of the sludge to be 4000-5000 mg/L. The first-stage treated water of a sewage treatment plant is taken as the water inlet of the embodiment, the COD is 296-379 mg/L, the total nitrogen is 52-79 mg/L, the ammonia nitrogen is 29-51 mg/L, the total phosphorus is 6-8 mg/L, and the pH is 6.5-7.5.

As shown in FIG. 2, the inflow water enters the fluidized bed activation reactor 4 through the inflow water pump 1, and mud-water-gas mixing occurs under the action of the disc type membrane microporous aerator 38 and the micro-nano bubble generating device 10, and the concentration of the dissolved oxygen of the system is periodically monitored to adjust the aeration quantity so as to control the concentration of the dissolved oxygen to be 4-6 mg/L. The bubbles are combined with activated sludge flocs and aerobic granular sludge, and the sludge is brought to the liquid level by the bubbles due to the existence of density difference. In the aeration process, part of sludge enters a built-in cyclone activator 5, and cyclone is generated under the action of a cyclone guide plate I6 and gravity so that the sludge moves downwards in a spiral way, when the sludge is settled to the bottom of a fluidized bed activation reactor 4, part of sludge continues to circulate in the first fluidized bed activation reactor 4, and the other part of sludge is introduced into a next-stage fluidized bed activation reactor from a water outlet of the first fluidized bed activation reactor 4, so that a new activation is started. And then sequentially enters the other boiling bed activation reactors, and the process not only activates the sludge, but also provides rich-lean nutrition period alternation for the whole system. The water outlet of the boiling bed activation reactor at the tail end is connected with the secondary sedimentation tank 13, the supernatant (effluent) flows out from the overflow weir water outlet 14 of the secondary sedimentation tank, and the settled and concentrated sludge flows into the reservoir 16 from the secondary sedimentation tank bottom flow port 15. The two return branches of the outlet of the reservoir 16 are controlled by means of a timed solenoid valve. The first 17 on time of the timing solenoid valve was set to 15s/5min (i.e., 15 seconds every 5 minutes) before significant granular sludge was found, and then the first 17 on time of the timing solenoid valve was set to 25s/5min. In order to avoid excessive sludge accumulation in the secondary sedimentation tank 13 when the first timing electromagnetic valve 17 is closed, the second timing electromagnetic valve 36 is set to be opened when the first timing electromagnetic valve 17 is closed, namely, the opening time of the second timing electromagnetic valve 36 in two stages is set to be 4min45s/5min and 4min 35s/5min respectively. The inlet flow rate of the classifier 22 was set to 0.4m by adjusting the gas-liquid mixing pump 18 and the second liquid flowmeter 19 ³ When the first timing electromagnetic valve 17 is opened, the sludge in the reservoir 16 enters the separator 22 tangentially under the action of the gas-liquid mixing pump 18 for separation, and the flocculent sludge with smaller density is discharged from the overflow pipe 28 of the separator under the action of the reinforced flocculent sludge and the granular sludge separation of the annular air diffuser 37, so that the flocculent sludge with larger density is dischargedSludge and granular sludge are discharged from the separator underflow pipe 27, and the sludge discharged from the separator underflow pipe 27 is then returned to the fluidized bed activation reactor return port 35. When the second timing solenoid valve 36 is opened, the sludge in the reservoir 16 is returned to the fluidized bed activation reactor return port 35 by the sludge return pump 37, and the total return ratio is set to 100%. In the reactor start-up phase, to avoid that the inoculated sludge is discharged in large quantity, the sludge discharged from the overflow pipe 28 of the classifier is optionally refluxed, or activated sludge is periodically added to the system so that the sludge concentration is not lower than 3000mg/L.

The first pressure sensor 20, the second pressure sensor 29 and the third pressure sensor 33 are respectively used for monitoring the pressures of the separator inlet 21, the overflow pipe 28 and the underflow pipe 27 in real time. The overflow variable frequency pump 30 has its pump inlet in communication with the classifier overflow pipe 28, and three pressure sensors, each in communication with the overflow variable frequency pump 30, are each in communication with the controller 32, and are capable of transmitting the monitored pressure values to the controller 32, and the controller 32 is capable of controlling the pump-out flow rate of the overflow variable frequency pump 30. The controller 32 adjusts and controls the pumping flow rate of the overflow variable frequency pump 30 in real time through the frequency converter 31 according to the change of the pressure drop ratio of the separator 22 (namely, the ratio of the pressure difference between the separator inlet 21 and the overflow pipe 28 and the pressure difference between the separator inlet 21 and the underflow pipe 27) measured by the three pressure sensors, and particularly increases or decreases the pumping flow rate of the overflow variable frequency pump 30 when the pressure drop ratio is not in the range of 110-120%, so as to realize the adjustment and control of the separation performance of the separator 22 and the autorotation characteristic of particles therein, namely, realize the real-time quantitative monitoring of the continuous flow aerobic particle sludge activity enhancement.

And monitoring the sludge characteristic parameter and the water quality parameter in the reaction process, and adjusting the operation parameter to maintain the stable operation of the reaction. After stable operation for 91 days, aerobic granular sludge is formed, the particle ratio reaches 72 percent, the average grain diameter of the sludge reaches 0.42mm, and the specific aerobic activity of the sludge is changed from original 12mg O ₂ The/g MLVSS.h is raised to 47mg O ₂ about/gMLVSS.h. The sewage treatment effect is good, the COD of the discharged water is 15-31 mg/L, the total nitrogen is 4.5-7.1 mg/L, the total phosphorus is 0.3-0.5 mg/L, and the ammonia nitrogen is kept below 0.5 mg/L.

The principles and embodiments of the present invention have been described in detail with reference to specific examples, which are provided to facilitate understanding of the method and core ideas of the present invention; also, it is within the scope of the present invention to be modified by those of ordinary skill in the art in light of the present teachings. In view of the foregoing, this description should not be construed as limiting the invention.

Claims (10)

1. A pressure-driven rotational flow reinforced continuous flow aerobic activated sludge granulation device is characterized in that: comprises a boiling bed activation reactor group, a secondary sedimentation tank, a reservoir, a separator, a controller, a pressure sensor and an overflow variable frequency pump; the fluidized bed activation reactor group comprises a plurality of fluidized bed activation reactors connected in series, a built-in cyclone activator is arranged in each fluidized bed activation reactor, and a cyclone guide plate is arranged in each cyclone activator; the separator is provided with a separator inlet, a separator underflow opening and a separator overflow opening, and a cyclone guide plate is arranged in the separator; the boiling bed activation reactor group is provided with a water inlet, a water outlet and a reflux port, the water outlet of the boiling bed activation reactor group is communicated with the secondary sedimentation tank, the bottom flow of the secondary sedimentation tank is led into a reservoir, the bottom outlet of the reservoir is provided with two reflux branches, one reflux branch is directly connected with the reflux port of the boiling bed activation reactor group, the other reflux branch is communicated with the inlet of the separator, the bottom flow port of the separator is communicated with the reflux port, and each reflux branch is internally provided with a timing electromagnetic valve; the overflow pipe is connected with the overflow pipe, the overflow port of the separator is connected with the overflow pipe, the three pressure sensors are respectively used for monitoring the pressure in the inlet of the separator, the overflow pipe and the underflow pipe, the pump inlet of the overflow variable frequency pump is communicated with the overflow pipe, and the controller can control the pumping flow rate of the overflow variable frequency pump.

2. The pressure driven cyclone enhanced continuous flow aerobic activated sludge granulation device according to claim 1, wherein: the water reservoir is communicated with the inlet of the separator through a pipeline, a gas-liquid mixing pump and a liquid flowmeter are arranged on the pipeline, the gas-liquid mixing pump can suck air while transporting liquid, and the gas-liquid mixing pump can mix mud-water mixture and air in the ebullated bed activation reactor in the gas-liquid mixing pump and then convey the mixture to the separator.

3. The pressure driven cyclone enhanced continuous flow aerobic activated sludge granulation device according to claim 1, wherein: the bottom opening of the built-in cyclone activator is also connected with a underflow pipe, and the underflow pipe adopts a ladder-shaped design.

4. The pressure driven cyclone enhanced continuous flow aerobic activated sludge granulation device according to claim 1, wherein: the built-in cyclone activator and the shell of the separator comprise a cylindrical section and a conical section, wherein the cylindrical section is positioned right above the conical section and is coaxially arranged with the conical section.

5. The pressure driven cyclone enhanced continuous flow aerobic activated sludge granulation device according to claim 4, wherein: the middle part of the cylindrical section is inwards concave, and the middle part of the conical section is outwards convex.

6. The pressure driven cyclone enhanced continuous flow aerobic activated sludge granulation device according to claim 4, wherein: the inner wall of the conical section and the inner surface of the underflow pipe are both processed by hydrophobic materials, and the inner wall of the cylindrical section and the inner surface of the overflow pipe are both processed by hydrophilic materials.

7. The pressure driven cyclone enhanced continuous flow aerobic activated sludge granulation device according to claim 4, wherein: the device also comprises an aeration device, wherein the aeration device is used for aerating at the bottom of each boiling bed activation reactor;

the aeration device comprises a gas generating device, gas pipes, a gas flowmeter and a plurality of air diffusers, wherein the air diffusers are microporous air diffusers or disc-type membrane microporous aerators, the gas pipes are uniformly distributed at the bottom of each ebullated bed activation reactor, the gas generating device can aerate the gas pipes, the air diffusers are arranged in each ebullated bed activation reactor, the gas inlets of the air diffusers are communicated with the gas pipes, and the gas flowmeter is used for monitoring the aeration amount of the gas generating device;

the gas generating device is a micro-nano bubble generating device.

8. The pressure driven cyclone enhanced continuous flow aerobic activated sludge granulation device according to claim 7, wherein: the separator conical section is provided with an annular air diffuser, and the annular air diffuser is connected with a micro-nano bubble generating device.

9. A continuous flow aerobic granular sludge activated cyclone strengthening method is characterized in that: the method is realized by using the pressure-driven cyclone reinforced continuous flow aerobic activated sludge granulation device according to any one of claims 1-8; characterized by comprising the following steps:

the pressure drop ratio of the separator is in the range of 110-120% by regulating the flow speed of the overflow variable frequency pump, and the pressure drop ratio is the ratio of the pressure difference between the inlet of the separator and the overflow pipe orifice of the separator and the pressure difference between the inlet of the separator and the underflow pipe orifice of the separator.

10. The method for enhancing the activated cyclone of the continuous-flow aerobic granular sludge according to claim 9, which is characterized in that: the control device also comprises a timing electromagnetic valve for controlling the opening and closing of each reflux branch;

the timing electromagnetic valve on the return branch between the bottom outlet of the reservoir and the inlet of the separator is a timing electromagnetic valve I, and the other timing electromagnetic valve II;

when the first timing electromagnetic valve is opened within a set time, the second timing electromagnetic valve is set to be in a closed state, and water discharged from the reservoir enters the separator at the moment, so that sludge separated by the separator is returned;

when the first timing electromagnetic valve is closed within a set time, the second timing electromagnetic valve is set to be in an open state, and water discharged from the reservoir flows back to the ebullated bed activation reactor at the moment;

and the second timing electromagnetic valve can be closed according to actual demands, so that the whole process is switched to a process that all the effluent of the reservoir enters the external cyclone activator.