Regulation and control method for rapid screening and enrichment of aerobic granular sludge and continuous flow reaction system

Abstract

The invention provides a regulation and control method for rapid screening and enrichment of aerobic granular sludge and a continuous flow reaction system, and relates to the field of sewage treatment. The method is applied to a continuous flow reaction system of the aerobic granular sludge, the continuous flow reaction system of the aerobic granular sludge comprises a sludge scraping device, a sludge settling zone is divided according to preset conditions, and the initial position of the sludge scraping device in the sludge settling zone is determined according to the preset conditions; the mud scraping device is installed at the initial position; regulating and controlling the primary sludge reflux quantity and the secondary sludge reflux quantity according to a preset first sludge concentration range and a preset second sludge concentration range; and when the sludge reflux quantity is changed along with the change of inlet water quality, inlet water quantity or sludge settling performance, and the sludge liquid level of the first-stage sludge reflux sludge bucket or the sludge liquid level of the second-stage sludge reflux sludge bucket exceeds a preset range, the sludge scraping device is adjusted according to the sludge scraping action of the sludge scraping device. The problems that in aerobic granular sludge culture, regulation and control of sedimentation selection pressure are complex, and the granulation process is slow are solved.

Description

Technical Field

[0001] The present application relates to the field of sewage treatment, and in particular to a control method for rapid screening and enrichment of aerobic granular sludge and a continuous flow reaction system. Background Art

[0002] In sewage treatment, aerobic granular sludge technology is mainly applied through continuous flow reactors. However, it is difficult for existing continuous flow reactors to exert selective pressure on activated sludge, resulting in the loss of granular sludge with good settling performance as the sludge is discharged, and it is unable to store and absorb sufficient organic matter for rapid growth; while flocculent sludge with poor settling performance flows back to the front end of the anaerobic tank and has an advantage in competing for carbon sources in the influent. All these make it difficult to quickly achieve sludge granulation and stable operation of the granular sludge system in the continuous flow reactor.

[0003] At present, some studies have achieved screening and separation by setting up multi-sludge hopper sedimentation tanks and segmented return of granular sludge at different times, but the regulation of sludge return is relatively complicated and cannot be applied to large-scale sewage treatment plants; some studies have flexibly adjusted the applied sedimentation selection pressure by adjusting the height of the movable baffle to achieve the screening effect on the sludge, but it is only suitable for operation under experimental conditions and is difficult to promote to industrial applications; some studies have used selective separation equipment (such as two-stage sedimentation tanks, hydrocyclones, etc.) to separate the heavy sludge particles from the light flocculent sludge, but it is impossible to dynamically adjust the sludge selection effect according to the granulation process.

[0004] In general, the existing continuous flow sedimentation tank structure control method is complex; it is impossible to dynamically adjust the sludge selection effect according to the granulation process, lacking flexibility; and it can only be applied to experiments or small sewage treatment plants, with limited application scope. The existing technology cannot achieve continuous and effective screening of heavy sludge and light sludge in actual engineering applications, resulting in the inability to promote rapid granulation, which in turn affects the efficiency of rapid screening and enrichment of aerobic granular sludge. Summary of the invention

[0005] The present application provides a method for regulating and controlling rapid screening and enrichment of aerobic granular sludge and a continuous flow aerobic granular sludge system, so as to solve the problem that the prior art cannot achieve continuous and effective screening of heavy sludge and light sludge in actual engineering applications, resulting in the inability to promote rapid granulation, thereby affecting the efficiency of rapid screening and enrichment of aerobic granular sludge.

[0006] In a first aspect, the present application provides a continuous flow reaction system for aerobic granular sludge, the system comprising: an anaerobic zone, an anoxic zone, an aerobic zone, a sedimentation device, and a reflow device;

[0007] The anaerobic zone and the anoxic zone both include multiple chambers, multiple partition walls, multiple water holes and multiple agitators; each chamber is provided with an agitator;

[0008] The aerobic zone includes: multiple aerobic tanks, baffles and microporous aeration devices;

[0009] The sedimentation device comprises: a guide plate, a primary sludge return hopper, a secondary sludge return hopper, a sludge sedimentation area and a sludge scraping device; the guide plate is arranged between the middle and the top of the water inlet end of the sedimentation device, the primary sludge return hopper is arranged at the bottom of the water inlet end of the sedimentation device, the secondary sludge return hopper is arranged at the bottom of the water outlet end of the sedimentation device, and the sludge scraping device is arranged in the sludge sedimentation area located in the middle of the sedimentation device;

[0010] The reflux device includes a nitrification liquid reflux device, a primary sludge reflux device and a secondary sludge reflux device. Both ends of the nitrification liquid reflux device are respectively connected to the aerobic zone, the anaerobic zone and the anoxic zone, both ends of the primary sludge reflux device are respectively connected to the primary sludge reflux hopper and the anaerobic zone, and both ends of the secondary sludge reflux device are respectively connected to the secondary sludge reflux hopper and the anoxic zone.

[0011] In a possible design, the mud scraping device includes: a transmission device, a mud scraping component and a track groove;

[0012] The transmission device includes: a reduction motor, a transmission main wheel, a transmission chain and a transmission pulley;

[0013] The scraper components include: a scraper blade, a scraper blade lifting motor and a scraper blade angle adjustment motor;

[0014] Driven by the reduction motor, the transmission main wheel is used to drive the scraper blade to perform scraping movement through the transmission chain via the transmission pulley; when the scraper blade lifting motor lifts the scraper blade, the scraper blade angle adjustment motor is used to adjust the angle of the scraper blade.

[0015] In a possible design, the nitrification liquid return device includes: an aeration device, an air inlet pipe, a water inlet, a sewage lifting pipe, an oxygen elimination box, a baffle cover and a return pipe;

[0016] The return pipe is connected to the respective multiple chambers of the anaerobic zone and the anoxic zone through the return branch pipe;

[0017] A solenoid valve is installed on each reflux branch pipe, and each solenoid valve is used to control the reflux of the nitrification solution, thereby adjusting the hydraulic retention time of the anaerobic zone and the anoxic zone respectively.

[0018] In one possible design, the area where the anaerobic, anoxic, and aerobic zones are located is divided into well-fed and starved zones;

[0019] The mud inlet of the primary sludge return device is located at the bottom of the primary sludge return hopper, the mud outlet of the primary sludge return device is located at the water inlet end of the anaerobic zone, the mud inlet of the secondary sludge return device is located at the bottom of the secondary sludge return hopper, and the mud outlet of the secondary sludge return device is located in the first chamber of the starvation zone;

[0020] The bottom of the primary sludge return hopper and the secondary sludge return hopper are both provided with a return pipe and a vent pipe;

[0021] The return pipe of the primary sludge return hopper is used to return the sludge at the water inlet end of the sludge sedimentation zone to the front end of the anaerobic zone;

[0022] The return pipe of the secondary sludge return hopper is used to return the sludge at the outlet end of the sludge sedimentation area to the front end of the hungry area, and the vent pipe of the secondary sludge return hopper is used to discharge excess sludge.

[0023] In one possible design, the system further includes an intelligent control device;

[0024] The intelligent control device is connected with the stirrer signal, and the intelligent control device is used to control the switch and stirring rate of the stirrer;

[0025] The intelligent control device is connected to the scraper device signal, and the intelligent control device is used to adjust the initial position and scraper frequency of the scraper device;

[0026] The intelligent control device is respectively connected with the online monitoring equipment signals of the anaerobic zone, the anoxic zone, the aerobic zone and the sedimentation device;

[0027] The intelligent control device is connected with the reflux pump signal of the reflux device, and the intelligent control device is used to adjust the switch of the reflux pump and the reflux flow rate.

[0028] In a second aspect, the present application provides a method for regulating and controlling rapid screening and enrichment of aerobic granular sludge, the method is applied to a continuous flow reaction system of aerobic granular sludge, the continuous flow reaction system of aerobic granular sludge includes a sludge scraping device, and the method includes:

[0029] Divide the sludge settling area according to the preset conditions, and determine the initial position of the sludge scraper device in the sludge settling area according to the preset conditions;

[0030] Install the scraper device at the initial position;

[0031] According to the preset first sludge concentration range and second sludge concentration range, the primary sludge return amount and the secondary sludge return amount are regulated;

[0032] When the sludge return amount changes with the changes in the influent water quality, influent amount or sludge settling performance, and the sludge liquid level in the return hopper exceeds the preset sludge liquid level height range during long-term operation, the scraping device is adjusted according to the scraping action of the scraping device, wherein the sludge return amount is the primary sludge return amount or the secondary sludge return amount.

[0033] In a possible design, the scraping action includes a primary scraping action and a secondary scraping action; wherein, the primary scraping action refers to the action of the scraper blade scraping from the initial position toward the primary sludge return hopper; the secondary scraping action refers to the action of the scraper blade scraping from the initial position toward the secondary sludge return hopper.

[0034] In a possible design, when the sludge return volume changes with the change of influent water quality, influent volume or sludge settling performance, and the sludge level in the return hopper exceeds the preset sludge level height range during long-term operation, the scraping device is adjusted according to the scraping action of the scraping device, including:

[0035] When the sludge return volume changes with the influent water quality or the sludge settling performance, the current sludge liquid height in the sludge return hopper is compared with the preset sludge liquid height range; wherein the sludge liquid height range includes the lowest sludge liquid level and the highest sludge liquid level;

[0036] When the current sludge liquid height is lower than the lowest liquid level of the sludge liquid, the sludge scraper device is moved in the opposite direction of the sludge return hopper until the current sludge liquid height is within the sludge liquid height range;

[0037] When the current sludge liquid height is higher than the maximum liquid level of the sludge liquid, the sludge scraper device is moved toward the sludge return hopper until the current sludge liquid height is within the sludge liquid height range.

[0038] In a possible design, the continuous flow reaction system of aerobic granular sludge includes: an anaerobic zone, an anoxic zone, an aerobic zone and an intelligent control device; the anaerobic zone, the anoxic zone and the aerobic zone are divided into a satiation zone and a hunger zone;

[0039] According to the preset first sludge concentration range and second sludge concentration range, the primary sludge return amount and the secondary sludge return amount are regulated, including:

[0040] The intelligent control device collects the sludge concentration in the saturated area, the sludge concentration at the first level bottom of the first level sludge return hopper, and the current water inflow in real time;

[0041] The primary sludge return volume of the primary sludge return hopper is calculated according to the sludge concentration in the saturated area, the primary bottom sludge concentration and the current influent flow rate;

[0042] According to the preset first sludge concentration range, the first bottom sludge concentration of the first sludge return hopper, and the current water inlet flow rate, the first sludge return amount range of the first sludge return hopper is calculated;

[0043] The primary sludge return flow rate is regulated according to the primary sludge return flow rate range until the primary sludge return flow rate is within the primary sludge return flow rate range.

[0044] In a possible design, the primary sludge return amount and the secondary sludge return amount are regulated according to the preset first sludge concentration range and the second sludge concentration range, and further includes:

[0045] The sludge concentration in the hungry area, the sludge concentration in the saturated area, the primary bottom sludge concentration of the primary sludge return hopper, the secondary bottom sludge concentration of the secondary sludge return hopper and the current water inflow are collected in real time through the intelligent control device;

[0046] The secondary sludge return volume of the secondary sludge return hopper is calculated according to the sludge concentration in the hungry zone, the sludge concentration in the saturated zone, the primary bottom sludge concentration, the secondary bottom sludge concentration and the current influent flow rate;

[0047] According to the preset second sludge concentration range, the sludge concentration in the saturated zone, the primary bottom sludge concentration, the secondary bottom sludge concentration and the current influent flow rate, the secondary sludge return flow rate range of the secondary sludge return hopper is calculated;

[0048] The secondary sludge return flow rate is regulated according to the secondary sludge return flow rate range until the secondary sludge return flow rate is within the secondary sludge return flow rate range.

[0049] In a possible design, the primary sludge return flow of the primary sludge return hopper is calculated based on the sludge concentration in the saturated zone, the primary bottom sludge concentration and the current inlet flow rate. The calculation formula is:

[0050]

[0051] Among them, L1 is the primary sludge return flow; M1 is the sludge concentration in the saturated zone; M3 is the primary bottom sludge concentration; Q is the current influent flow; a1 is the ratio of the primary sludge return concentration of the primary sludge return hopper to the primary bottom sludge concentration;

[0052] According to the sludge concentration in the hungry zone, the sludge concentration in the saturated zone, the primary bottom sludge concentration, the secondary bottom sludge concentration and the current influent flow, the secondary sludge return volume of the secondary sludge return hopper is calculated. The calculation formula is:

[0053]

[0054] Among them, R1 is the primary sludge return ratio; L2 is the secondary sludge return amount; M2 is the sludge concentration in the starvation zone; M4 is the secondary bottom sludge concentration; a2 is the ratio of the secondary sludge return concentration of the secondary sludge return hopper to the secondary bottom sludge concentration.

[0055] In a possible design, the preset conditions include: hydraulic retention time, a first sludge concentration range, and a second sludge concentration range;

[0056] Divide the sludge settling area according to the preset conditions, and determine the initial position of the sludge scraper in the sludge settling area according to the preset conditions, including:

[0057] According to the hydraulic retention time, the sludge sedimentation area is equally divided into multiple sections, and each sludge scraper is adjusted and installed at the end of each section;

[0058] Start the scraper device and adjust the initial position of the scraper device according to the first sludge concentration range and the second sludge concentration range, so that the primary sludge return amount is within the primary sludge return amount range, and the secondary sludge return amount is within the secondary sludge return amount range, and the sludge liquid level in the return hopper is stable within the preset sludge liquid level height range.

[0059] In a possible design, adjusting the initial position of the sludge scraper according to the first sludge concentration range and the second sludge concentration range includes:

[0060] When the primary sludge return flow rate is lower than the minimum flow rate of the primary sludge return flow rate range, the initial position of the scraper device is moved in the opposite direction of the primary sludge return hopper;

[0061] When the primary sludge return flow rate is higher than the maximum flow rate of the primary sludge return flow rate range, the initial position of the scraper device is moved toward the primary sludge return hopper;

[0062] When the secondary sludge return flow rate is lower than the minimum flow rate of the secondary sludge return flow rate range, the initial position of the scraper device is moved in the opposite direction of the secondary sludge return hopper;

[0063] When the secondary sludge return flow rate is higher than the maximum flow rate of the secondary sludge return flow rate range, the initial position of the scraper device is moved toward the secondary sludge return hopper.

[0064] The present application provides a control method and continuous flow reaction system for rapid screening and enrichment of aerobic granular sludge, the method is applied to the continuous flow reaction system of aerobic granular sludge, the continuous flow reaction system of aerobic granular sludge includes a scraper device, the sludge sedimentation area is divided according to preset conditions, and the initial position of the scraper device in the sludge sedimentation area is determined according to the preset conditions; the scraper device is installed at the initial position; the primary sludge return amount and the secondary sludge return amount are controlled according to the preset first sludge concentration range and the second sludge concentration range; when the sludge return amount changes with the influent water quality or influent amount, the scraper device is adjusted according to the scraping action of the scraper device. Compared with the prior art, it is impossible to achieve continuous and effective screening of heavy sludge and light sludge in actual engineering applications, resulting in the inability to promote rapid granulation, which in turn affects the efficiency of rapid screening and enrichment of aerobic granular sludge. The present application utilizes the sedimentation characteristics of the horizontal flow sedimentation tank to simply convert the traditional one-way scraper into a two-way scraper, so that the sludge with good sedimentation performance is returned and the sludge with poor sedimentation performance is discharged, thereby providing sedimentation selection pressure for the formation of granular sludge in the continuous flow system, realizing the dual functions of sludge sedimentation and granular sludge screening, ensuring the stability of the system, promoting the rapid enrichment and growth of aerobic granular sludge, accelerating the granulation process, and thereby improving the efficiency of rapid screening and enrichment of aerobic granular sludge. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0066] Figure 1 A schematic diagram of a continuous flow reaction system of aerobic granular sludge provided in an embodiment of the present application Figure 1 ;

[0067] Figure 2 A schematic diagram of a continuous flow reaction system of aerobic granular sludge provided in an embodiment of the present application Figure 2 ;

[0068] Figure 3 A schematic diagram of a continuous flow reaction system of aerobic granular sludge provided in an embodiment of the present application Figure 3 ;

[0069] Figure 4 A schematic diagram of a method for rapid screening and enrichment of aerobic granular sludge provided in an embodiment of the present application Figure 1 ;

[0070] Figure 5A schematic diagram of a method for rapid screening and enrichment of aerobic granular sludge provided in an embodiment of the present application Figure 2 ;

[0071] Figure 6 A schematic diagram of a method for rapid screening and enrichment of aerobic granular sludge provided in an embodiment of the present application Figure 3 ;

[0072] Figure 7 A schematic diagram of a method for rapid screening and enrichment of aerobic granular sludge provided in an embodiment of the present application Figure 4 ;

[0073] Figure 8 A schematic diagram of a method for rapid screening and enrichment of aerobic granular sludge provided in an embodiment of the present application Figure 5 .

[0074] Reference numerals:

[0075] 111-partition wall; 112-first chamber of anaerobic zone; 113-second chamber of anaerobic zone; 114-third chamber of anaerobic zone; 116-agitator;

[0076] 121-the first chamber of the hypoxic zone; 122-the second chamber of the hypoxic zone; 123-the third chamber of the hypoxic zone; 124-the fourth chamber of the hypoxic zone; 125-the fifth chamber of the hypoxic zone;

[0077] 131- baffle plate; 132- first aerobic tank; 133- second aerobic tank; 134- third aerobic tank; 135- fourth aerobic tank; 136- fifth aerobic tank; 137- sixth aerobic tank; 138- microporous aeration device;

[0078] 141- guide plate; 142- primary sludge return hopper; 143- secondary sludge return hopper; 144- sludge sedimentation area; 145- sludge scraping device;

[0079] 1451-transmission device; 1452-scraping mud component; 1453-track groove;

[0080] 14511-reduction motor; 14512-transmission main wheel; 14513-transmission chain; 14514-transmission pulley;

[0081] 14521-scraper; 14522-scraper lifting motor; 14523-scraper angle adjustment motor;

[0082] 151-nitrification liquid reflux device;

[0083] 1511-aeration device; 1512-air inlet pipe; 1513-water inlet; 1514-sewage lifting pipe; 1515-oxidation box; 1516-flow shield; 1517-return pipe;

[0084] 15171-the first reflux branch; 15172-the second reflux branch; 15173-the third reflux branch; 15174-the fourth reflux branch. DETAILED DESCRIPTION

[0085] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0086] In the embodiments of the present application, words such as "first" and "second" are used to distinguish the same or similar items with basically the same functions and effects. Those skilled in the art will understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit the difference. It should be noted that in the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplary" or "for example" in the present application should not be interpreted as being more preferred or more advantageous than other embodiments or design schemes. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way. In the embodiments of the present application, "at least one" refers to one or more, and "more" refers to two or more.

[0087] It should be noted that the "at..." in the embodiments of the present application can be the instant when a certain situation occurs, or it can be a period of time after a certain situation occurs, and the embodiments of the present application do not specifically limit this. In addition, the control method for rapid screening and enrichment of aerobic granular sludge and the continuous flow aerobic granular sludge system provided in the embodiments of the present application are only used as examples, and the control method for rapid screening and enrichment of aerobic granular sludge can also include more or less content.

[0088] In order to clearly describe the technical solutions of the embodiments of the present application, some terms and technologies involved in the embodiments of the present application are briefly introduced below:

[0089] Aerobic Granular Sludge (AGS): Aerobic granular sludge is a granular activated sludge formed by microbial self-agglomeration, which has a dense structure, good sedimentation performance and excellent decontamination ability. It is achieved in the form of a sequencing batch reactor (SBR).

[0090] Saturated zone and starved zone: In the entire biochemical treatment unit, the area where microorganisms grow with external matrix is ​​called the saturated zone, and the area where they grow with internal matrix is ​​called the starved zone. Under this alternating condition of satiety and starvation, microorganisms will secrete a large amount of extracellular polymers (EPS). These EPS are retained in the reactor, which is conducive to the aggregation and adsorption of particles and accelerates the formation of granular sludge. The alternation of satiety and starvation conditions will inhibit the reproduction of filamentous microorganisms and facilitate the growth of flocculating bacteria.

[0091] Extracellular polymers (EPS): are organic macromolecular substances secreted outside the cells by microorganisms during their growth and metabolism. These substances are mainly composed of complex organic substances such as polysaccharides, proteins, nucleic acids, lipids and humus. They form a protective layer around microbial cells and play an important role in the survival and reproduction of microorganisms.

[0092] However, it is difficult for a continuous flow reactor to exert selective pressure on the activated sludge by gradually reducing the sludge settling time as in a sequencing batch reactor. As a result, the sludge with good settling performance is lost with the sludge discharge, while the flocculent sludge with poor settling performance flows back to the front end of the anaerobic tank and has an advantage in competing for carbon sources in the influent. The granular sludge with good settling performance cannot store and absorb sufficient organic matter and grow rapidly. Therefore, it is difficult to quickly achieve sludge granulation and stable operation of the granular sludge system in a continuous flow reactor, resulting in the fact that the promotion and application of AGS in the continuous flow field has not yet achieved a substantial breakthrough.

[0093] In the existing technology, some studies have further enhanced the gravity selection pressure of granular sludge by utilizing the sedimentation and reasonable discharge of activated sludge. Setting up a multi-sludge hopper sedimentation tank is a good device for screening, separating and segmented return of granular sludge at different stages. However, it is only suitable for small-scale sewage treatment plants and is more complicated in regulating sludge return.

[0094] Some studies have flexibly adjusted the applied sedimentation selection pressure by adjusting the height of the movable baffle to achieve the screening effect on the sludge. The limitation of this device is that it is only suitable for operation under experimental conditions and is difficult to promote to industrial applications.

[0095] Some studies have achieved selective separation of sludge by settling heavy sludge particles at the bottom of the first sedimentation tank and light flocculent sludge at the bottom of the second sedimentation tank. However, the selective separation function of this device cannot dynamically adjust the sludge selection effect according to the granulation process.

[0096] The continuous flow sedimentation tank structure in the prior art cannot achieve continuous and effective screening of heavy sludge and light sludge in actual engineering applications, thereby promoting rapid granulation, resulting in poor efficiency in rapid screening and enrichment of aerobic granular sludge.

[0097] Based on this, in order to solve the above technical problems, the embodiment of the present application provides a method for regulating and controlling aerobic granular sludge rapid screening and enrichment and a continuous flow reaction system, which can be used in the field of sewage treatment. The inventive concept of the present application is: how to effectively improve the efficiency of aerobic granular sludge rapid screening and enrichment.

[0098] Optionally, an embodiment of the present application provides a continuous flow reaction system for aerobic granular sludge, comprising: an anaerobic zone, an anoxic zone, an aerobic zone, a sedimentation device and a reflux device, wherein the areas where the anaerobic zone, the anoxic zone and the aerobic zone are located are divided into a satiety zone and a hunger zone.

[0099] The anaerobic zone and the anoxic zone both include multiple chambers, multiple partition walls, multiple water holes and multiple stirrers; each chamber is provided with a stirrer; the aerobic zone includes: multiple aerobic tanks, baffles and microporous aeration devices; the sedimentation device includes: a guide plate, a primary sludge return hopper, a secondary sludge return hopper, a sludge sedimentation zone and a sludge scraper; the guide plate is arranged between the middle and top of the water inlet end of the sedimentation device, the primary sludge return hopper is arranged at the bottom of the water inlet end of the sedimentation device, the secondary sludge return hopper is arranged at the bottom of the water outlet end of the sedimentation device, and the sludge scraper is arranged in the sludge sedimentation zone located in the middle of the sedimentation device; the reflux device includes a nitrification liquid reflux device, a primary sludge reflux device and a secondary sludge reflux device, two ends of the nitrification liquid reflux device are respectively connected to the aerobic zone, the anaerobic zone and the anoxic zone, two ends of the primary sludge reflux device are respectively connected to the primary sludge return hopper and the anaerobic zone, and two ends of the secondary sludge reflux device are respectively connected to the secondary sludge return hopper and the anoxic zone.

[0100] like Figure 1 As shown, the continuous flow reaction system of aerobic granular sludge is divided into multiple chambers by multiple partition walls 111, and each partition wall 111 is sequentially provided with water holes arranged one above and one below, and each chamber is sequentially connected through the water holes.

[0101] Specifically, the number of chambers can be divided according to the volumes of the anaerobic zone and the anoxic zone.

[0102] Specifically, a stirrer 116 is provided in each chamber of the anaerobic zone and the anoxic zone, and the dissolved oxygen level in the anaerobic zone and the anoxic zone can be regulated by the stirring rate.

[0103] Optionally, a plurality of adjacent chambers can form an anaerobic zone, and a plurality of adjacent chambers can form an anoxic zone. Figure 1 In the figure, the three chambers in the upper left corner (the first two chambers in the first row and the first chamber in the second row from the top row) are anaerobic zones, and the five chambers in the upper right corner (the last two chambers in the first row and the last three chambers in the second row from the top row) are anoxic zones.

[0104] For example, in Figure 1 In the embodiment, the chambers of the anaerobic zone are the first anaerobic chamber 112, the second anaerobic chamber 113 and the third anaerobic chamber 114; the chambers of the anoxic zone are the first anoxic chamber 121, the second anoxic chamber 122, the third anoxic chamber 123, the fourth anoxic chamber 124 and the fifth anoxic chamber 125.

[0105] The six chambers in the lower right corner (the last two columns from the third row to the fifth row from the top) are the aerobic zones.

[0106] The aerobic zone is divided into a plurality of aerobic pools by a plurality of baffles 131, and a microporous aeration device 138 is also provided at the bottom of the aerobic zone.

[0107] Specifically, the setting of the baffle 131 can prevent short-circuiting of the incoming water on the one hand, and improve the height-to-diameter ratio of a single tank body on the other hand, and provide stronger hydraulic shear force for the mud-water mixture in the aerobic tank through ascending aeration.

[0108] More specifically, the number of aerobic pools can be set by calculating the hydraulic shear force of a single pool, which can generally be set to 0.1-0.3 cm / s. At the same time, it is also necessary to ensure that the dissolved oxygen in the aerobic pool is controlled within the set range.

[0109] For example, in Figure 1 In the aerobic zone, the aerobic pools are a first aerobic pool 132 , a second aerobic pool 133 , a third aerobic pool 134 , a fourth aerobic pool 135 , a fifth aerobic pool 136 and a sixth aerobic pool 137 .

[0110] The lower left corner is a sedimentation device, which includes: a guide plate 141 (see Figure 2 As shown), a primary sludge return hopper 142, a secondary sludge return hopper 143, a sludge sedimentation area 144 and a sludge scraping device 145.

[0111] Specifically, the water inlet of the sedimentation device is located at the front end, and the water outlet of the sedimentation device is located at the rear end. The water inlet of the sedimentation device is close to the water inlet of the anaerobic zone, and the water outlet of the sedimentation device is close to the water outlet of the aerobic zone.

[0112] The reflux device includes: a nitrification liquid reflux device 151, a primary sludge reflux device and a secondary sludge reflux device.

[0113] The water inlet of the nitrification liquid reflux device 151 is located at the bottom of the water outlet of the sixth aerobic tank 137, and the water outlet of the nitrification liquid reflux device 151 is located at the bottom of multiple chambers in the anaerobic zone and the anoxic zone through the reflux branch pipe.

[0114] Among them, the mud inlet of the primary sludge return device is located at the bottom of the primary sludge return hopper 142, the mud outlet of the primary sludge return device is located at the water inlet end of the anaerobic zone, the mud inlet of the secondary sludge return device is located at the bottom of the secondary sludge return hopper 143, and the mud outlet of the secondary sludge return device is located in the first chamber of the starvation zone.

[0115] Among them, the primary sludge return device and the secondary sludge return device use diaphragm pump return. The diaphragm pump can reduce the damage of mechanical return to the granular sludge structure. Compared with the air lift return method, it can also greatly reduce the dissolved oxygen entering the front anaerobic zone to destroy the anaerobic environment.

[0116] Specifically, ordinary sewage treatment plants have only one return system for sludge return. However, since the organic matter concentration of the influent of general municipal systems is relatively low and the organic matter of the influent of continuous flow systems is greatly diluted, in order to ensure the food-microorganism ratio in the satiety stage, the first-level sludge return device provided in this application mainly returns the sludge with good sedimentation performance at the front end of the sludge sedimentation area 144 to the front end of the anaerobic zone for sufficient organic matter absorption.

[0117] Furthermore, considering that the amount of sludge returned from the saturated zone is too small, the overall sludge concentration of the system may be reduced, thereby affecting the denitrification and phosphorus removal efficiency of the back-end system. In order to ensure the basic denitrification and phosphorus removal functions during the granular sludge cultivation period, a secondary sludge return device is used to return part of the sludge in the back-end mud hopper to the hungry zone to reduce the impact on the denitrification in the hungry zone and the nitrification efficiency in the aerobic zone.

[0118] It should be noted that the continuous flow reaction system of aerobic granular sludge also includes an intelligent control device 160 .

[0119] The intelligent control device 160 is connected to the stirrer 116 by signal, and the intelligent control device 160 is used to control the start and stop of the stirrer 116 and the stirring rate.

[0120] The intelligent control device 160 is connected to the nitrification liquid reflux device 151, the primary sludge reflux device and the secondary sludge reflux device, and the electromagnetic valve signal on the reflux branch. The intelligent control device 160 is used to control the start and stop of the reflux pump, the reflux flow rate, and the opening and closing of the electromagnetic valve;

[0121] The intelligent control device 160 is connected to the scraper device 145 by signal, and the intelligent control device 160 is used to adjust the initial position and scraper frequency of the scraper device 145 .

[0122] The intelligent control device 160 is respectively connected to the online monitoring devices of the anaerobic zone, the anoxic zone, the aerobic zone, the sedimentation device and the reflux device.

[0123] Among them, the online monitoring equipment includes: a COD online monitor, an ammonia nitrogen online detector and an inlet online flow meter installed on the front water inlet pipe of the anaerobic zone; a sludge online concentration meter installed at the bottom of the first chamber 112 and the first aerobic tank 132 of the anaerobic zone; an online sludge concentration meter and a sludge level meter installed at the bottom of the primary sludge return hopper 142 and the secondary sludge return hopper 143; an online COD monitor installed in the last chamber of the satiety zone and the first chamber of the hunger zone; an ammonia nitrogen online monitor installed at the outlet of the aerobic zone; a DO meter, a pH meter and an ORP meter installed at the water inlet of the anaerobic zone, the anoxic zone and the aerobic zone; and an online flow meter installed on the reflux pipe 1517, the primary reflux pipe 1421 and the secondary reflux pipe 1431.

[0124] In addition, the air intake of each aerobic tank in the aerobic zone is individually controlled by the solenoid valve on the air intake branch pipe. The opening and closing degree of the air intake solenoid valve is adjusted by the intelligent control device 160 to control the DO concentration of each tank body to be 1.5-4.5 mg / L, and gradually decreases along the way; at the same time, the intelligent control device 160 can further adjust the DO in the aeration tank according to the online monitoring data of ammonia nitrogen at the outlet of the aerobic zone, which can greatly reduce the aeration energy consumption in the sewage treatment process.

[0125] In this embodiment, the multi-chamber setting can make the influent present an overall plug flow state during the flow along the way, while ensuring that the mud and water in each chamber are fully mixed, which can improve the absorption and storage of organic matter in the influent by the microorganisms in the front anaerobic and anoxic zones, reduce the system's satiation-hunger ratio, and promote the rapid enrichment of functional microorganisms such as denitrifying polyphosphate bacteria and denitrifying polysaccharide bacteria.

[0126] Figure 2 A schematic diagram of a continuous flow reaction system of aerobic granular sludge provided in an embodiment of the present application Figure 2 , where the areas where the anaerobic zone, the anoxic zone and the aerobic zone are located are divided into the satiation zone and the hunger zone, such as Figure 2 As shown, the sedimentation device includes: a guide plate 141, a primary sludge return hopper 142, a secondary sludge return hopper 143, a sludge sedimentation area 144 and a sludge scraping device 145.

[0127] The mud inlet of the primary sludge return device is located at the bottom of the primary sludge return hopper 142, and the mud outlet of the primary sludge return device is located at the water inlet end of the anaerobic zone. The mud inlet of the secondary sludge return device is located at the bottom of the secondary sludge return hopper 143, and the mud outlet of the secondary sludge return device is located in the first chamber of the starvation zone; a return pipe and a vent pipe are provided at the bottom of the primary sludge return hopper 142 and the secondary sludge return hopper 143; the return pipe of the primary sludge return hopper 142 is used to return the sludge at the water inlet end of the sludge sedimentation zone 144 to the front end of the anaerobic zone; the return pipe of the secondary sludge return hopper 143 is used to return the sludge at the water outlet end of the sludge sedimentation zone 144 to the front end of the starvation zone, and the vent pipe of the secondary sludge return hopper is used to discharge excess sludge.

[0128] Among them, the guide plate 141 is arranged at 0.5-1.0m at the water inlet end of the sedimentation device, with a submerged depth of 0.3-0.5m and 0.1-0.15m above the water surface; the first-level sludge return hopper 142 is arranged at the bottom of the water inlet end of the sedimentation device; the second-level sludge return hopper 143 is arranged at the bottom of the water outlet end of the sedimentation device; the sludge sedimentation area 144 is arranged in the middle of the sedimentation device; the sludge scraper device 145 is arranged in the sludge sedimentation area 144.

[0129] Among them, a primary return pipe 1421 and a primary vent pipe 1422 are provided at the bottom of the primary sludge return hopper 142.

[0130] Specifically, the primary return pipe 1421 of the primary sludge return hopper 142 is used to return the front end sludge of the sludge sedimentation area 144 to the water inlet end of the anaerobic area.

[0131] A secondary return pipe 1431 and a secondary vent pipe 1432 are provided at the bottom of the secondary sludge return hopper 143 .

[0132] Specifically, the secondary return pipe 1431 of the secondary sludge return hopper 143 is used to return the sludge at the outlet end of the sludge sedimentation area 144 to the front end of the starvation area, and the secondary vent pipe 1432 of the secondary sludge return hopper 143 is used to discharge excess sludge and is used as a sludge external discharge pipe of the system.

[0133] In addition, the longitudinal slope of the bottom of the primary sludge return hopper 142 and the secondary sludge return hopper 143 is set to 0.015-0.02.

[0134] The mud scraping device 145 includes: a transmission device 1451 , a mud scraping component 1452 , and a track groove 1453 .

[0135] The transmission device 1451 includes: a reduction motor 14511 , a transmission main wheel 14512 , a transmission chain 14513 and a transmission pulley 14514 .

[0136] The scraper component 1452 includes a scraper blade 14521 , a scraper blade lifting motor 14522 and a scraper blade angle adjustment motor 14523 .

[0137] It should be noted that the scraper device 145 is a bidirectional scraper, and the operating mechanism of the bidirectional scraper is as follows:

[0138] The transmission main wheel 14512 is driven by the reduction motor 14511 to drive the scraper blade 14521 to scrape mud through the transmission chain 14513 and the transmission pulley 14514.

[0139] When adjusting the scraping direction, the scraper plate lifting motor 14522 drives the scraper plate 14521 to lift, and the scraper plate angle adjustment motor 14523 adjusts the angle of the scraper plate 14521 according to the set angle. The scraper plate lifting motor 14522 then lowers the scraper plate 14521 to fit the bottom of the pool and continues to scrape in the opposite direction.

[0140] It should also be noted that the running track of the two-way scraper is:

[0141] Specifically, the scraping component 1452 performs reciprocating motion and flap motion on the track groove 1453 under the traction of the transmission device 1451. When scraping mud, it first runs from the initial position toward the primary sludge return hopper 142, and scrapes the activated sludge with good sedimentation performance at the front end to the primary sludge return hopper 142. After scraping, it returns to the initial position, and then runs in the opposite direction to scrape the remaining sludge at the rear end of the sedimentation area into the secondary sludge return hopper 143.

[0142] More specifically, when the scraper blade 14521 scrapes mud from a certain position in the middle to both ends, it forms an angle of 60° with the ground. When returning from both ends to the middle, the scraper blade flips 60° toward the ground and runs horizontally with the ground. Rubber plates are installed at the lower end of the scraper blade 14521 and the pool wall end.

[0143] For example, the principle of granular sludge screening is as follows:

[0144] Specifically, the granular sludge is approximately regarded as spherical particles, and its sedimentation rate when freely sedimenting in the vertical direction follows the Stokes equation:

[0145] u=gd 2 (ρ s -ρ) / 18μ

[0146] Where u is the particle settling velocity in cm / s; ρ s , ρ are the density of particles and water, respectively, in g / cm; g is the acceleration due to gravity, in cm / s 2 ; μ is the adhesion coefficient of water, unit is Pa·s; d is the particle diameter, unit is cm.

[0147] Specifically, the larger the particle density and diameter, the greater the particle settling speed in the vertical direction, while the particle speed in the horizontal direction is mainly affected by the inlet flow rate. Therefore, at the bottom of the horizontal flow sedimentation tank, the sludge with larger particle density and diameter is closer to the inlet end, while the sludge with smaller particle density and diameter is closer to the outlet end of the sedimentation tank. According to the above principle, a sludge sedimentation hopper is set at the inlet end and the outlet end of the sedimentation tank. The sludge with good front-end settling performance and large particle size is scraped to the front-end hopper (primary sludge return hopper 142) by a scraper, and returned to the inlet end of the anaerobic tank. This part of the sludge can fully absorb organic matter in the inlet water and grow and enrich rapidly; while the sludge with slightly poor settling performance is scraped to the outlet hopper (secondary sludge return hopper 143), part of which is returned to the hungry area through the secondary return pipe to supplement the system sludge volume, and the other part is discharged through the sludge external discharge pipe.

[0148] In this embodiment, the different natural settling rates of granular sludge of different particle sizes in the sludge sedimentation area are utilized to simply convert the traditional one-way scraper into a two-way scraper. The operation trajectory of the scraper is regulated by an intelligent control device, so that the sludge with good sedimentation performance is returned and the sludge with poor sedimentation performance is discharged, thereby providing sedimentation selection pressure for the formation of granular sludge, and realizing the dual functions of sludge sedimentation and granular sludge screening.

[0149] Figure 3 A schematic diagram of a continuous flow reaction system of aerobic granular sludge provided in an embodiment of the present application Figure 3 ,like Figure 3 As shown, the nitrification liquid reflux device 151 includes: an aeration device 1511, an air inlet pipe 1512, a water inlet 1513, a sewage lifting pipe 1514, an oxygen removal box 1515, a baffle 1516 and a reflux pipe 1517.

[0150] The nitrification liquid reflux device 151 adopts gas stripping reflux, and by injecting gas, the partial pressure of each phase in the sewage is changed to promote the separation and removal of pollutants.

[0151] The water inlet 1513 is located at the bottom of the water outlet of the aerobic zone.

[0152] The slope of the horizontal reflux pipeline connected after the deoxidation box 1515 is designed to be 1% to 3% to ensure that the reflux nitrification liquid flows into the anoxic zone by gravity.

[0153] The reflux pipe 1517 is provided with multiple outlets, which are connected to the multiple chambers of the anaerobic zone and the anoxic zone through the reflux branch pipes.

[0154] For example, the reflux pipe 1517 refluxes to the third chamber 114 of the anaerobic zone, the first chamber 121 of the anoxic zone, the second chamber 122 of the anoxic zone and the third chamber 123 of the anoxic zone through the first reflux branch pipe 15171, the second reflux branch pipe 15172, the third reflux branch pipe 15173 and the fourth reflux branch pipe 15174 respectively. A solenoid valve is installed on each branch pipe, and each solenoid valve is used to control the reflux of the nitrification liquid, and can adjust the hydraulic retention time of the anaerobic zone and the anoxic zone by starting and stopping the solenoid valve.

[0155] Specifically, anaerobic functional bacteria need to be rapidly enriched in the early stage of granular sludge culture, but the growth cycle of functional bacteria such as denitrifying polyphosphate bacteria and denitrifying polysaccharide bacteria is relatively long. Therefore, the hydraulic retention time of the anaerobic zone can be appropriately increased in the early stage of culture, and the hydraulic retention time of the anoxic zone can be reduced. In the later stage of culture, in order to improve the efficiency of simultaneous nitrification and denitrification in the anoxic zone, the hydraulic retention time of the anoxic zone can be appropriately increased in the same way.

[0156] More specifically, a reflux point is set in each of the front chambers, and during operation, the hydraulic retention time of the anaerobic zone and the anoxic zone can be regulated by changing the reflux point of the mixed liquid reflux ratio and combining the stirring rate of the agitator.

[0157] For example, the water inlet valves on the first return branch 15171 of the third chamber 114 of the anaerobic zone, the second return branch 15172 of the first chamber 121 of the anoxic zone, and the third return branch 15173 of the second chamber 122 of the anoxic zone can be closed, and the water inlet valve on the fourth return branch 15174 of the third chamber 123 of the anoxic zone can be opened, and at the same time, the rotation speed of the agitator 116 in the first chamber 121 of the anoxic zone and the second chamber 122 of the anoxic zone can be adjusted to the size of the anaerobic zone.

[0158] For example, the nitrification liquid can be returned to each anoxic pool by adjusting the opening and closing degree of the water inlet valves on the reflux branches of the first anoxic chamber 121, the second anoxic chamber 122, and the third anoxic chamber 123, respectively.

[0159] In addition, the hydraulic retention time of each chamber in the anaerobic and anoxic zones was controlled at 15 to 30 min.

[0160] Optionally, the above system also includes an intelligent control device; the intelligent control device is connected to the agitator signal, and the intelligent control device is used to control the switch of the agitator and the stirring rate; the intelligent control device is connected to the scraper device signal, and the intelligent control device is used to adjust the initial position and scraper frequency of the scraper device; the intelligent control device is respectively connected to the online monitoring equipment signals of the anaerobic zone, anoxic zone, aerobic zone and sedimentation device; the intelligent control device is connected to the reflux pump signal of the reflux device, and the intelligent control device is used to adjust the switch of the reflux pump and the reflux flow rate.

[0161] Figure 4 A schematic diagram of a method for rapid screening and enrichment of aerobic granular sludge provided in an embodiment of the present application Figure 1 .like Figure 4 As shown, the method is applied to a continuous flow reaction system of aerobic granular sludge, and the continuous flow reaction system of aerobic granular sludge includes a sludge scraping device, and the method includes:

[0162] S401, dividing the sludge settling area according to preset conditions, and determining the initial position of the sludge scraper device in the sludge settling area according to the preset conditions.

[0163] In this embodiment, before the continuous flow reaction system of aerobic granular sludge is officially operated, the sludge sedimentation area is first divided according to preset conditions, and then the initial position of the sludge scraper in the sludge sedimentation area is determined according to the preset conditions.

[0164] Specifically, when the sludge scraping device is located at the initial position, it can ensure that the amount of sludge in the primary sludge return hopper and the secondary sludge return hopper can meet the stable operation of the primary sludge return device and the secondary sludge return device. That is, it is ensured that the mud level height in the primary sludge return hopper and the secondary sludge return hopper is always within the preset range during the stable operation of the device, and the amount of sludge therein can meet the continuous supply of sludge in the primary sludge return hopper and the secondary sludge return hopper during the sludge scraping process, and will not exceed the hopper capacity.

[0165] S402, installing the mud scraper device at the initial position.

[0166] S403, regulating the primary sludge return amount and the secondary sludge return amount according to the preset first sludge concentration range and the second sludge concentration range.

[0167] In this embodiment, during the formal operation of the continuous flow reaction system of aerobic granular sludge, it is necessary to regulate the primary sludge return flow rate and the secondary sludge return flow rate in real time according to the preset first sludge concentration range and the second sludge concentration range, so as to keep the system running smoothly.

[0168] S404. When the sludge return volume changes with the influent water quality, influent volume or sludge settling performance, and the sludge level in the return hopper exceeds the preset sludge level height range during long-term operation, the scraping device is adjusted according to the scraping action of the scraping device.

[0169] Among them, the sludge return volume is the primary sludge return volume or the secondary sludge return volume.

[0170] In this embodiment, when the inlet water quality or water volume fluctuates greatly, resulting in large fluctuations in the sludge return volume, or the activated sludge settling performance changes significantly during the cultivation process, resulting in changes in the sludge distribution at the bottom of the sedimentation tank, resulting in the set scraper initial position or scraping frequency parameters being unable to meet the stable operation of the primary and secondary reflow systems, the intelligent control device of the continuous flow reaction system of aerobic granular sludge regularly adjusts the scraping device according to the scraping action of the scraping device and the liquid level sensors in the primary sludge return hopper and the secondary sludge return hopper.

[0171] It should be noted that the scraping action includes primary scraping action and secondary scraping action; wherein, the primary scraping action refers to the action of the scraper blade scraping mud from the initial position toward the primary sludge return hopper; the secondary scraping action refers to the action of the scraper blade scraping mud from the initial position toward the secondary sludge return hopper.

[0172] The present embodiment provides a control method and a continuous flow reaction system for rapid screening and enrichment of aerobic granular sludge. The method is applied to the continuous flow reaction system of aerobic granular sludge. The continuous flow reaction system of aerobic granular sludge includes a scraper device, which divides the sludge sedimentation area according to preset conditions, and determines the initial position of the scraper device in the sludge sedimentation area according to the preset conditions; installs the scraper device at the initial position; regulates the primary sludge return volume and the secondary sludge return volume according to the preset first sludge concentration range and the second sludge concentration range; when the sludge return volume changes with the influent water quality or influent volume, the scraper device is adjusted according to the scraping action of the scraper device. Compared with the prior art, it is impossible to achieve continuous and effective screening of heavy sludge and light sludge in actual engineering applications, resulting in the inability to promote rapid granulation, which in turn affects the efficiency of rapid screening and enrichment of aerobic granular sludge. The present application utilizes the sedimentation characteristics of the horizontal flow sedimentation tank to simply convert the traditional one-way scraper into a two-way scraper, so that the sludge with good sedimentation performance is returned and the sludge with poor sedimentation performance is discharged, thereby providing sedimentation selection pressure for the formation of granular sludge in the continuous flow system, realizing the dual functions of sludge sedimentation and granular sludge screening, ensuring the stability of the system, promoting the rapid enrichment and growth of aerobic granular sludge, accelerating the granulation process, and thereby improving the efficiency of rapid screening and enrichment of aerobic granular sludge.

[0173] Figure 5 A schematic diagram of a method for rapid screening and enrichment of aerobic granular sludge provided in an embodiment of the present application Figure 2 ,exist Figure 4 Based on the example, Figure 5 As shown, the specific implementation steps of the above S404 include:

[0174] S501. When the sludge return amount changes with the influent water quality or the sludge settling performance, the current sludge liquid height in the sludge return hopper is compared with a preset sludge liquid height range.

[0175] The sludge liquid height range includes the lowest liquid level of the sludge liquid and the highest liquid level of the sludge liquid.

[0176] Specifically, the preset minimum liquid level of the sludge liquid just meets the continuous supply of sludge in the primary sludge return hopper and the secondary sludge return hopper during the sludge scraping process.

[0177] More specifically, during the cultivation period of the continuous flow reaction system of aerobic granular sludge, as the functional microorganisms are enriched and the granular sludge is gradually formed, the food-microorganism ratio in the reaction zone needs to be adjusted regularly, which also means that the sludge return ratio needs to be adjusted synchronously. In addition, the overall sedimentation performance of the sludge is improved, and the sludge sedimentation distribution in the sludge sedimentation zone changes, resulting in the set scraper initial position or scraping frequency parameters being unable to meet the stable operation of the return system. The intelligent control device regularly adjusts the scraper initial position, moves it to the left or right for several intervals, or corrects the scraping frequency parameters until the sludge level in the sludge return hopper is stably maintained within the set range.

[0178] S502: When the current sludge liquid height is lower than the lowest liquid level of the sludge liquid, the sludge scraping device is moved in the opposite direction of the sludge return hopper until the current sludge liquid height is within the sludge liquid height range.

[0179] S503, when the current sludge liquid height is higher than the maximum liquid level of the sludge liquid, the sludge scraping device is moved toward the sludge return hopper until the current sludge liquid height is within the sludge liquid height range.

[0180] In this embodiment, the initial position of the scraper is regularly adjusted by the intelligent control device, moved to the left or right by several intervals, or the scraping frequency parameters are corrected, thereby ensuring that the sludge liquid level in the sludge return hopper is stably maintained within the set range, maintaining the stable operation of the entire system, and thereby improving the regulation efficiency of rapid screening and enrichment of aerobic granular sludge.

[0181] Figure 6 A schematic diagram of a method for rapid screening and enrichment of aerobic granular sludge provided in an embodiment of the present application Figure 3 ,exist Figure 5 and Figure 4 Based on the example, Figure 6 As shown, the continuous flow reaction system of aerobic granular sludge includes: an anaerobic zone, an anoxic zone, an aerobic zone and an intelligent control device; the anaerobic zone, the anoxic zone and the aerobic zone are divided into a satiation zone and a hunger zone; then the specific implementation steps of the above S403 include:

[0182] S601. The sludge concentration in the saturated area, the primary bottom sludge concentration of the primary sludge return hopper, and the current water inlet flow are collected in real time through the intelligent control device.

[0183] S602, calculating the primary sludge return flow rate of the primary sludge return hopper according to the sludge concentration in the saturated area, the primary bottom sludge concentration and the current water inlet flow rate.

[0184] The calculation formula is:

[0185]

[0186] Among them, L1 is the primary sludge return flow; M1 is the sludge concentration in the saturated zone; M3 is the primary bottom sludge concentration; Q is the current inlet flow; a1 is the ratio of the primary sludge return concentration to the primary bottom sludge concentration of the primary sludge return hopper.

[0187] In addition, the empirical value of a1 is generally set at 0.6-0.8, and the average value can be calculated after multiple actual sampling tests. This value needs to be adjusted regularly during the granular sludge cultivation process.

[0188] S603, calculating a first sludge return amount range of the first sludge return hopper according to a preset first sludge concentration range, a first bottom sludge concentration of the first sludge return hopper, and a current water inlet flow rate.

[0189] In this embodiment, during the granular sludge cultivation process, the first sludge concentration in the saturated zone needs to be maintained in the range of 3 to 3.5 mg / L. Specifically, the first sludge concentration can be maintained by regulating the primary sludge return amount in the primary sludge return hopper.

[0190] In addition, the first sludge concentration range can be adjusted according to actual conditions.

[0191] S604, regulating the primary sludge return amount according to the primary sludge return amount range until the primary sludge return amount is within the primary sludge return amount range.

[0192] In this embodiment, the setting of the two-stage sludge return strategy simultaneously ensures the functions of returning sludge screening and maintaining system stability. The first-stage sludge return ensures that the sludge with good sedimentation performance can be preferentially returned to the front-end anaerobic tank and absorb organic matter in the influent, grow and enrich rapidly, thereby improving the regulation efficiency of rapid screening and enrichment of aerobic granular sludge.

[0193] Figure 7 A schematic diagram of a method for rapid screening and enrichment of aerobic granular sludge provided in an embodiment of the present application Figure 4 ,exist Figure 4 , Figure 5 and Figure 6 Based on the example, Figure 7 As shown, the specific implementation steps of the above S403 also include:

[0194] S701. The sludge concentration in the hungry zone, the sludge concentration in the saturated zone, the primary bottom sludge concentration, the secondary bottom sludge concentration of the secondary sludge return hopper and the current water inlet flow are collected in real time through the intelligent control device.

[0195] S702, calculating the secondary sludge return volume of the secondary sludge return hopper according to the sludge concentration in the hungry zone, the sludge concentration in the saturated zone, the primary bottom sludge concentration, the secondary bottom sludge concentration and the current influent flow rate.

[0196] The calculation formula is:

[0197]

[0198] Among them, R1 is the primary sludge return ratio; L2 is the secondary sludge return amount; M2 is the sludge concentration in the starvation zone; M4 is the secondary bottom sludge concentration; a2 is the ratio of the secondary sludge return concentration of the secondary sludge return hopper to the secondary bottom sludge concentration.

[0199] In addition, the empirical value of a2 is generally set at 0.6-0.8, and the average value can be calculated after multiple actual sampling tests. This value needs to be adjusted regularly during the granular sludge cultivation process.

[0200] S703, calculating the secondary sludge return flow range of the secondary sludge return hopper according to the preset second sludge concentration range, the sludge concentration in the saturated zone, the primary bottom sludge concentration, the secondary bottom sludge concentration and the current inlet flow.

[0201] In this embodiment, during the granular sludge cultivation process, the second sludge concentration in the starvation zone needs to be maintained in the range of 4-5 mg / L, which can be achieved by regulating the secondary sludge return flow rate in the secondary sludge return hopper.

[0202] S704, regulating the secondary sludge return amount according to the secondary sludge return amount range until the secondary sludge return amount is within the secondary sludge return amount range.

[0203] In this embodiment, the setting of the two-stage sludge return strategy simultaneously ensures the functions of return sludge screening and maintaining system stability. The secondary sludge return ensures the sustainability of the basic denitrification and phosphorus removal functions of the system by maintaining the stability of the system sludge concentration, thereby improving the regulation efficiency of rapid screening and enrichment of aerobic granular sludge.

[0204] Figure 8 A schematic diagram of a method for rapid screening and enrichment of aerobic granular sludge provided in an embodiment of the present application Figure 5 ,exist Figure 4 , Figure 5 , Figure 6 and Figure 7 Based on the example, Figure 8 As shown, the preset conditions include: hydraulic retention time, the first sludge concentration range and the second sludge concentration range, and the specific implementation steps of the above S401 include:

[0205] S801. Divide the sludge settling area into multiple sections according to the hydraulic retention time, and adjust and install each sludge scraper device at the end of each section.

[0206] In this embodiment, the sludge sedimentation area is divided into n intervals according to its size, and the hydraulic retention time of each interval is controlled to be 5 to 10 minutes. The scraper is started at the initial stage of operation, and the initial position of the scraper is adjusted to the end of each interval before formal startup.

[0207] S802, start the scraper device, and adjust the initial position of the scraper device according to the first sludge concentration range and the second sludge concentration range, so that the primary sludge return amount is within the primary sludge return amount range, and the secondary sludge return amount is within the secondary sludge return amount range, and the sludge liquid level in the return hopper is stable within the preset sludge liquid level height range.

[0208] In this embodiment, the particle size distribution of activated sludge in the sludge sedimentation area at the initial startup is detected by an intelligent control device, and the scraper position and scraping frequency at the initial operation are determined according to the sludge return volume at the system startup stage, to ensure that the amount of sludge in the return sludge hopper after the scraper is started at this position can meet the stable operation of the primary and secondary sludge return systems, that is, to ensure that the mud level height in the primary and secondary sludge return hoppers is always within the set range, wherein the sludge amount in the hopper can meet the continuous supply of sludge in the primary and secondary sludge return hoppers during the scraping process and will not exceed the hopper capacity.

[0209] Specific:

[0210] When the primary sludge return flow rate is lower than the minimum flow rate of the primary sludge return flow rate range, the initial position of the scraper device is moved in the opposite direction of the primary sludge return hopper.

[0211] When the primary sludge return flow rate is higher than the maximum flow rate of the primary sludge return flow rate range, the initial position of the scraper device is moved toward the primary sludge return hopper.

[0212] When the secondary sludge return flow rate is lower than the minimum flow rate of the secondary sludge return flow rate range, the initial position of the scraper device is moved in the opposite direction of the secondary sludge return hopper.

[0213] When the secondary sludge return flow rate is higher than the maximum flow rate of the secondary sludge return flow rate range, the initial position of the scraper device is moved toward the secondary sludge return hopper.

[0214] In this embodiment, the different natural settling rates of granular sludge of different particle sizes in the sludge sedimentation area are utilized to simply convert the traditional one-way scraper into a two-way scraper. The operation trajectory of the scraper is regulated by an intelligent control device, so that the sludge with good sedimentation performance is returned and the sludge with poor sedimentation performance is discharged, thereby providing sedimentation selection pressure for the formation of granular sludge. At the same time, the dual functions of sludge sedimentation and granular sludge screening are realized, thereby improving the regulation efficiency of rapid screening and enrichment of aerobic granular sludge.

[0215] So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present application is obviously not limited to these specific embodiments, and the above embodiments are only used to illustrate the technical solution of the present application rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A continuous flow reaction system for aerobic granular sludge, characterized in that: The system comprises: an anaerobic zone, an anoxic zone, an aerobic zone, a sedimentation device and a reflow device; The anaerobic zone and the anoxic zone both include a plurality of chambers, a plurality of partition walls, a plurality of water holes and a plurality of agitators; one agitator is arranged in each chamber; The aerobic zone includes: a plurality of aerobic tanks, baffles and microporous aeration devices; The sedimentation device comprises: a guide plate, a primary sludge return hopper, a secondary sludge return hopper, a sludge sedimentation area and a sludge scraping device; the guide plate is arranged between the middle and the top of the water inlet end of the sedimentation device, the primary sludge return hopper is arranged at the bottom of the water inlet end of the sedimentation device, the secondary sludge return hopper is arranged at the bottom of the water outlet end of the sedimentation device, and the sludge scraping device is arranged in the sludge sedimentation area located in the middle of the sedimentation device; The reflux device includes a nitrification liquid reflux device, a primary sludge reflux device and a secondary sludge reflux device. The two ends of the nitrification liquid reflux device are respectively connected to the aerobic zone, the anaerobic zone and the anoxic zone. The two ends of the primary sludge reflux device are respectively connected to the primary sludge reflux hopper and the anaerobic zone. The two ends of the secondary sludge reflux device are respectively connected to the secondary sludge reflux hopper and the anoxic zone.

2. The system according to claim 1, characterized in that The mud scraping device comprises: a transmission device, a mud scraping component and a track groove; The transmission device comprises: a reduction motor, a transmission main wheel, a transmission chain and a transmission pulley; The scraper components include: a scraper blade, a scraper blade lifting motor and a scraper blade angle adjustment motor; Driven by the reduction motor, the transmission main wheel is used to drive the scraper blade to perform scraping movement through the transmission chain via the transmission pulley; when the scraper blade lifting motor lifts the scraper blade, the scraper blade angle adjustment motor is used to adjust the angle of the scraper blade.

3. The system according to claim 2, characterized in that The nitrification liquid reflux device comprises: an aeration device, an air inlet pipe, a water inlet, a sewage lifting pipe, an oxygen elimination box, a baffle cover and a reflux pipe; The return pipe is connected to the respective multiple chambers of the anaerobic zone and the anoxic zone through the return branch pipe; A solenoid valve is installed on each of the reflux branches, and each of the solenoid valves is used to control the reflux of the nitrification liquid, thereby adjusting the hydraulic retention time of the anaerobic zone and the anoxic zone, respectively.

4. The system according to claim 3, characterized in that The area where the anaerobic zone, the anoxic zone and the aerobic zone are located is divided into a satiation zone and a hunger zone; The mud inlet of the primary sludge return device is located at the bottom of the primary sludge return hopper, the mud outlet of the primary sludge return device is located at the water inlet end of the anaerobic zone, the mud inlet of the secondary sludge return device is located at the bottom of the secondary sludge return hopper, and the mud outlet of the secondary sludge return device is located in the first chamber of the starvation zone; The bottom of the primary sludge return hopper and the secondary sludge return hopper are both provided with the return pipe and the vent pipe; The return pipe of the primary sludge return hopper is used to return the sludge at the water inlet end of the sludge sedimentation zone to the front end of the anaerobic zone; The return pipe of the secondary sludge return hopper is used to return the sludge at the outlet end of the sludge sedimentation zone to the front end of the starvation zone, and the vent pipe of the secondary sludge return hopper is used to discharge excess sludge.

5. The system according to claim 4, characterized in that The system also includes an intelligent control device; The intelligent control device is connected to the stirrer signal, and the intelligent control device is used to control the switch and stirring rate of the stirrer; The intelligent control device is connected to the scraping device by signal, and the intelligent control device is used to adjust the initial position and scraping frequency of the scraping device; The intelligent control device is respectively connected to the online monitoring devices of the anaerobic zone, the anoxic zone, the aerobic zone and the precipitation device by signals; The intelligent control device is connected to the reflux pump signal of the reflux device, and the intelligent control device is used to adjust the switch of the reflux pump and the reflux flow rate.

6. A method for rapid screening and enrichment of aerobic granular sludge, characterized in that: The method is applied to a continuous flow reaction system of aerobic granular sludge, and the continuous flow reaction system of aerobic granular sludge includes a sludge scraping device, and the method includes: Divide the sludge settling area according to preset conditions, and determine the initial position of the sludge scraper device in the sludge settling area according to the preset conditions; Installing the scraper device at the initial position; According to the preset first sludge concentration range and second sludge concentration range, the primary sludge return amount and the secondary sludge return amount are regulated; When the sludge return amount changes with the changes in the influent water quality, influent amount or sludge settling performance, and the sludge liquid level in the return hopper exceeds the preset sludge liquid level height range during long-term operation, the scraping device is adjusted according to the scraping action of the scraping device, wherein the sludge return amount is the primary sludge return amount or the secondary sludge return amount.

7. The method according to claim 6, characterized in that The scraping action includes a primary scraping action and a secondary scraping action; wherein, the primary scraping action refers to the action of the scraper blade scraping mud from the initial position toward the primary sludge return hopper; the secondary scraping action refers to the action of the scraper blade scraping mud from the initial position toward the secondary sludge return hopper.

8. The method according to claim 7, characterized in that When the sludge return amount changes with the change of the influent water quality, influent amount or sludge settling performance, and the sludge liquid level in the return hopper exceeds the preset sludge liquid level height range during long-term operation, the sludge scraping device is adjusted according to the scraping action of the sludge scraping device, including: When the sludge return amount changes with the change of the influent water quality or the sludge settling performance, the current sludge liquid height in the sludge return hopper is compared with a preset sludge liquid height range; wherein the sludge liquid height range includes the lowest sludge liquid level and the highest sludge liquid level; When the current sludge liquid height is lower than the lowest liquid level of the sludge liquid, the sludge scraping device is moved in the opposite direction of the sludge return hopper until the current sludge liquid height is within the sludge liquid height range; When the current sludge liquid height is higher than the maximum liquid level of the sludge liquid, the scraping device is moved toward the sludge return hopper until the current sludge liquid height is within the sludge liquid height range.

9. The method according to claim 8, characterized in that The continuous flow reaction system of aerobic granular sludge comprises: an anaerobic zone, an anoxic zone, an aerobic zone and an intelligent control device; the anaerobic zone, the anoxic zone and the aerobic zone are divided into a satiation zone and a hunger zone; The method of regulating the primary sludge return amount and the secondary sludge return amount according to the preset first sludge concentration range and the second sludge concentration range includes: The intelligent control device collects the sludge concentration in the saturated area, the primary bottom sludge concentration of the primary sludge return hopper, and the current water inflow in real time; The primary sludge return amount of the primary sludge return hopper is calculated according to the sludge concentration in the saturated zone, the primary bottom sludge concentration and the current water inlet flow rate; Calculate the range of the primary sludge return flow rate of the primary sludge return hopper according to the preset first sludge concentration range, the primary bottom sludge concentration of the primary sludge return hopper, and the current water inflow rate; The primary sludge return amount is regulated according to the primary sludge return amount range until the primary sludge return amount is within the primary sludge return amount range.

10. The method according to claim 9, characterized in that The regulating the primary sludge return amount and the secondary sludge return amount according to the preset first sludge concentration range and the second sludge concentration range also includes: The sludge concentration in the hungry zone, the sludge concentration in the saturated zone, the primary bottom sludge concentration of the primary sludge return hopper, the secondary bottom sludge concentration of the secondary sludge return hopper and the current water inflow are collected in real time by the intelligent control device; The secondary sludge return amount of the secondary sludge return hopper is calculated according to the sludge concentration in the hungry zone, the sludge concentration in the saturated zone, the primary bottom sludge concentration, the secondary bottom sludge concentration and the current influent flow rate; Calculate the secondary sludge return amount range of the secondary sludge return hopper according to the preset second sludge concentration range, the saturated zone sludge concentration, the primary bottom sludge concentration, the secondary bottom sludge concentration and the current influent flow rate; The secondary sludge return amount is regulated according to the secondary sludge return amount range until the secondary sludge return amount is within the secondary sludge return amount range.

11. The method according to claim 10, characterized in that The first-level sludge return amount of the first-level sludge return hopper is calculated according to the sludge concentration in the saturated zone, the first-level bottom sludge concentration and the current water inlet flow rate, and the calculation formula is: Wherein, L1 is the primary sludge return flow; M1 is the sludge concentration in the saturated zone; M3 is the primary bottom sludge concentration; Q is the current influent flow; a1 is the ratio of the primary sludge return concentration of the primary sludge return hopper to the primary bottom sludge concentration; The secondary sludge return amount of the secondary sludge return hopper is calculated according to the sludge concentration in the hungry zone, the sludge concentration in the saturated zone, the primary bottom sludge concentration, the secondary bottom sludge concentration and the current influent flow rate, and the calculation formula is: Among them, R1 is the primary sludge return ratio; L2 is the secondary sludge return amount; M2 is the sludge concentration in the starvation zone; M4 is the secondary bottom sludge concentration; a2 is the ratio of the secondary sludge return concentration of the secondary sludge return hopper to the secondary bottom sludge concentration.

12. The method according to claim 6, characterized in that The preset conditions include: hydraulic retention time, the first sludge concentration range and the second sludge concentration range; The method of dividing the sludge settling area according to preset conditions and determining the initial position of the sludge scraper in the sludge settling area according to the preset conditions includes: According to the hydraulic retention time, the sludge settling area is equally divided into a plurality of sections, and each of the sludge scraping devices is adjusted and installed at the end of each of the sections; Start the scraper device and adjust the initial position of the scraper device according to the first sludge concentration range and the second sludge concentration range, so that the primary sludge return amount is within the primary sludge return amount range, and the secondary sludge return amount is within the secondary sludge return amount range, and the sludge liquid level in the return hopper is stabilized within the preset sludge liquid level height range.

13. The method according to claim 12, characterized in that Adjusting the initial position of the scraper device according to the first sludge concentration range and the second sludge concentration range includes: When the primary sludge return flow rate is lower than the minimum flow rate of the primary sludge return flow rate range, the initial position of the scraper device is moved in the opposite direction of the primary sludge return hopper; When the primary sludge return flow rate is higher than the maximum flow rate of the primary sludge return flow rate range, the initial position of the scraper device is moved toward the primary sludge return hopper; When the secondary sludge return flow rate is lower than the minimum flow rate of the secondary sludge return flow rate range, the initial position of the scraper device is moved in the opposite direction of the secondary sludge return hopper; When the secondary sludge return flow rate is higher than the maximum flow rate of the secondary sludge return flow rate range, the initial position of the scraper device is moved toward the secondary sludge return hopper.

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