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

Abstract

The application provides a kind of aerobic granular sludge rapid screening enrichment regulation method and continuous flow reaction system, and relates to the field of wastewater treatment.The method is applied to the continuous flow reaction system of aerobic granular sludge, which includes a mud scraping device, the sludge sedimentation zone is divided according to the preset conditions, and the initial position of the mud scraping device in the sludge sedimentation zone is determined according to the preset conditions;The mud scraping device is installed at the initial position;According to the first sludge concentration range and the second sludge concentration range, the primary sludge reflux and the secondary sludge reflux are regulated;When the sludge reflux changes with the change of water quality, water quantity or sludge settling performance, resulting in the primary sludge reflux hopper liquid level or the secondary sludge reflux hopper sludge liquid level exceeding the preset range, the mud scraping device is adjusted according to the mud scraping action of the mud scraping device.The problems of slow granulation process and complex settling selection pressure regulation in aerobic granular sludge cultivation are solved.

Description

Technical Field

[0001] This application relates to the field of wastewater treatment, and in particular to a method for rapid screening and enrichment of aerobic granular sludge and a continuous flow reaction system. Background Technology

[0002] In wastewater treatment, aerobic granular sludge technology is mainly applied through continuous flow reactors. However, existing continuous flow reactors struggle to apply selective pressure to activated sludge, causing granular sludge with good settling properties to be lost during sludge discharge, failing to store and absorb sufficient organic matter for rapid growth; while flocculent sludge with poor settling properties is returned to the front end of the anaerobic tank and dominates in competition for carbon sources in the influent. These factors make it difficult to quickly achieve sludge granulation and stable operation of the granular sludge system in continuous flow reactors.

[0003] Currently, some studies use multi-hopper sedimentation tanks to achieve screening and separation of granular sludge at different stages and segmented return of sludge. However, the control of sludge return is quite complex and cannot be applied to large-scale wastewater treatment plants. Some studies use the height of movable baffles to flexibly adjust the applied settling selective pressure to achieve sludge screening, but this is only suitable for experimental operation and is difficult to promote to industrial applications. Some studies use selective separation equipment (such as two-stage sedimentation tanks, hydrocyclones, etc.) to separate heavy sludge particles from light flocculent sludge for sedimentation, but they cannot dynamically adjust the sludge selection effect according to the granulation process.

[0004] In summary, existing continuous flow sedimentation tank structural control methods are complex; they cannot dynamically adjust the sludge selection effect according to the granulation process, lacking flexibility; and they can only be applied to experiments or small-scale wastewater treatment plants, limiting their application scope. Existing technologies cannot achieve continuous and effective screening of heavy and light sludge in practical engineering applications, hindering rapid granulation and consequently affecting the efficiency of rapid screening and enrichment of aerobic granular sludge. Summary of the Invention

[0005] This application provides a method for controlling the rapid screening and enrichment of aerobic granular sludge and a continuous flow aerobic granular sludge system, which solves the problem that existing technologies cannot achieve continuous and effective screening of heavy sludge and light sludge in practical engineering applications, resulting in the inability to promote rapid granulation and thus affecting the efficiency of rapid screening and enrichment of aerobic granular sludge.

[0006] In one aspect, this 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 reflux device;

[0007] Both the anaerobic and anoxic zones include multiple chambers, multiple partitions, multiple water passages, and multiple stirrers; each chamber contains one stirrer.

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

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

[0010] The reflux system includes a nitrification liquor reflux system, a primary sludge reflux system, and a secondary sludge reflux system. The two ends of the nitrification liquor reflux system are connected to the aerobic zone, the anaerobic zone, and the anoxic zone, respectively. The two ends of the primary sludge reflux system are connected to the primary sludge reflux hopper and the anaerobic zone, respectively. The two ends of the secondary sludge reflux system are connected to the secondary sludge reflux hopper and the anoxic zone, respectively.

[0011] In one possible design, the sludge scraping device includes: a transmission device, sludge scraping components, and a track groove;

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

[0013] The sludge scraping components include: a sludge scraper, a sludge scraper lifting motor, and a sludge scraper angle adjusting motor;

[0014] Driven by the geared motor, the transmission main wheel drives the scraper blade to scrape mud via the transmission chain and transmission pulley; when the scraper blade lifting motor lifts the scraper blade, the scraper blade angle adjusting motor is used to adjust the angle of the scraper blade.

[0015] In one possible design, the nitrification liquid return device includes: an aeration device, an air inlet pipe, an inlet, a wastewater lift pipe, a deaeration tank, a baffle shroud, and a return pipe;

[0016] The reflux pipe connects multiple chambers in the anaerobic zone and the anoxic zone through reflux branch pipes;

[0017] Each return branch is equipped with a solenoid valve, which is used to control the return of nitrified liquor, thereby adjusting the hydraulic retention time of the anaerobic and anoxic zones.

[0018] In one possible design, the areas containing the anaerobic zone, the hypoxic zone, and the aerobic zone are divided into a satiated zone and a starving zone.

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

[0020] Both the primary sludge return hopper and the secondary sludge return hopper are equipped with return pipes and vent pipes at the bottom.

[0021] The return pipe of the primary sludge return hopper is used to return the sludge from the inlet end of the sludge settling 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 from the effluent end of the sludge settling 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.

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

[0024] The intelligent control device is connected to the stirrer via a signal, and is used to control the on / off state of the stirrer and the stirring rate.

[0025] The intelligent control device is connected to the mud scraper via a signal, and the intelligent control device is used to adjust the initial position and mud scraping frequency of the mud scraper.

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

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

[0028] Secondly, this application provides a method for rapid screening and enrichment of aerobic granular sludge, applied to a continuous flow reaction system of aerobic granular sludge, the continuous flow reaction system of aerobic granular sludge including a sludge scraping device, the method comprising:

[0029] The 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 preset conditions.

[0030] Install the sludge scraper in the initial position;

[0031] The primary sludge return flow rate and the secondary sludge return flow rate are adjusted according to the preset first sludge concentration range and the second sludge concentration range.

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

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

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

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

[0036] When the current sludge liquid level is lower than the minimum sludge liquid level, the sludge scraper will be moved in the opposite direction to the sludge return hopper until the current sludge liquid level is within the sludge liquid level range.

[0037] When the current sludge liquid level is higher than the maximum sludge liquid level, move the sludge scraper towards the sludge return hopper until the current sludge liquid level is within the sludge liquid level range.

[0038] In one 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, anoxic zone, and aerobic zone are divided into a saturated zone and a starved zone.

[0039] Based on the preset first and second sludge concentration ranges, the primary and secondary sludge return flows are adjusted, including:

[0040] The concentration of sludge in the saturated zone, the concentration of sludge at the bottom of the primary sludge return hopper, and the current influent flow rate are collected in real time through an intelligent control device.

[0041] The primary sludge return flow rate 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 influent flow rate.

[0042] Based on the preset first sludge concentration range, the first-level bottom sludge concentration of the first-level sludge return hopper, and the current influent flow rate, the first-level sludge return flow rate range of the first-level sludge return hopper is calculated.

[0043] Adjust the primary sludge return flow rate 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 one possible design, the primary sludge return flow rate and the secondary sludge return flow rate are adjusted according to a preset first sludge concentration range and a second sludge concentration range, and the adjustment also includes:

[0045] The intelligent control device collects the sludge concentration in the starving zone, the sludge concentration in the saturated zone, the sludge concentration at the bottom of the primary sludge return hopper, the sludge concentration at the bottom of the secondary sludge return hopper, and the current influent flow rate in real time.

[0046] The secondary sludge return flow rate of the secondary sludge return hopper is calculated based on the sludge concentration in the starving 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] Based on the preset range of second sludge concentration, sludge concentration in the saturated zone, bottom sludge concentration in the primary stage, bottom sludge concentration in the secondary stage, and current influent flow rate, the range of secondary sludge return flow rate in the secondary sludge return hopper is calculated.

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

[0049] In one possible design, the primary sludge return flow rate 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 influent flow rate. The calculation formula is as follows:

[0050]

[0051] Where L1 is the primary sludge return flow rate; M1 is the sludge concentration in the saturated zone; M3 is the primary bottom sludge concentration; Q is the current influent flow rate; and a1 is the ratio of the primary sludge return concentration to the primary bottom sludge concentration in the primary sludge return hopper.

[0052] Based on the sludge concentrations in the starving zone, 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 to the secondary sludge return hopper is calculated using the following formula:

[0053]

[0054] Where R1 is the primary sludge return ratio; L2 is the secondary sludge return flow rate; M2 is the sludge concentration in the starvation zone; M4 is the secondary bottom sludge concentration; and a2 is the ratio of the secondary sludge return concentration to the secondary bottom sludge concentration in the secondary sludge return hopper.

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

[0056] The sludge settling zone is divided according to preset conditions, and the initial position of the scraper device in the sludge settling zone is determined according to preset conditions, including:

[0057] Based on the hydraulic retention time, the sludge settling zone is divided into multiple sections, and each scraper device is adjusted and installed at the end of each section.

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

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

[0060] When the primary sludge return flow rate is lower than the minimum flow rate within the primary sludge return flow rate range, the initial position of the sludge scraper will be moved in the opposite direction to the primary sludge return sludge 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 sludge scraper will be moved toward the primary sludge return sludge hopper.

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

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

[0064] This application provides a method for controlling the rapid screening and enrichment of aerobic granular sludge and a continuous flow reaction system. The method is applied to a continuous flow reaction system for aerobic granular sludge, which includes a scraping device. The system divides the sludge settling zone according to preset conditions and determines the initial position of the scraping device within the settling zone based on these preset conditions. The scraping device is then installed at the initial position. The primary and secondary sludge return flows are controlled according to preset first and second sludge concentration ranges. When the sludge return flow changes with influent water quality or flow rate, the scraping device is adjusted based on its scraping action. Compared to existing technologies, this method cannot achieve continuous and effective screening of heavy and light sludge in practical engineering applications, resulting in the inability to promote rapid granulation and thus affecting the efficiency of rapid screening and enrichment of aerobic granular sludge. This application utilizes the sedimentation characteristics of a horizontal flow sedimentation tank to simply modify a traditional unidirectional sludge scraper into a bidirectional sludge scraper. This allows for the return of sludge with good sedimentation performance and the discharge of sludge with poor sedimentation performance, thereby providing settling selection pressure for the formation of granular sludge in the continuous flow system. This achieves the dual functions of sludge settling and granular sludge screening, ensuring system stability, promoting the rapid enrichment and growth of aerobic granular sludge, accelerating the granulation process, and thus improving the efficiency of rapid screening and enrichment of aerobic granular sludge. Attached Figure Description

[0065] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0066] Figure 1 A schematic diagram of the structure of a continuous flow reaction system for aerobic granular sludge provided in this application embodiment. Figure 1 ;

[0067] Figure 2 A schematic diagram of the structure of a continuous flow reaction system for aerobic granular sludge provided in this application embodiment. Figure 2 ;

[0068] Figure 3 A schematic diagram of the structure of a continuous flow reaction system for aerobic granular sludge provided in this application embodiment. Figure 3 ;

[0069] Figure 4 A flowchart illustrating a method for rapid screening and enrichment of aerobic granular sludge provided in this application embodiment. Figure 1 ;

[0070] Figure 5A flowchart illustrating a method for rapid screening and enrichment of aerobic granular sludge provided in this application embodiment. Figure 2 ;

[0071] Figure 6 A flowchart illustrating a method for rapid screening and enrichment of aerobic granular sludge provided in this application embodiment. Figure 3 ;

[0072] Figure 7 A flowchart illustrating a method for rapid screening and enrichment of aerobic granular sludge provided in this application embodiment. Figure 4 ;

[0073] Figure 8 A flowchart illustrating a method for rapid screening and enrichment of aerobic granular sludge provided in this application embodiment. Figure 5 .

[0074] Figure label:

[0075] 111 - Partition wall; 112 - First anaerobic chamber; 113 - Second anaerobic chamber; 114 - Third anaerobic chamber; 116 - Stirrer;

[0076] 121 - First chamber of the hypoxic zone; 122 - Second chamber of the hypoxic zone; 123 - Third chamber of the hypoxic zone; 124 - Fourth chamber of the hypoxic zone; 125 - 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 settling zone; 145-Sludge scraper;

[0079] 1451 - Transmission device; 1452 - Sludge scraping component; 1453 - Track groove;

[0080] 14511 - Gear motor; 14512 - Transmission main wheel; 14513 - Transmission chain; 14514 - Transmission pulley;

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

[0082] 151 - Nitration liquor reflux device;

[0083] 1511-Aeration device; 1512-Air inlet pipe; 1513-Water inlet; 1514-Sewage lifting pipe; 1515-Deaeration box; 1516-Baffle; 1517-Return pipe;

[0084] 15171 - First reflux branch pipe; 15172 - Second reflux branch pipe; 15173 - Third reflux branch pipe; 15174 - Fourth reflux branch pipe. Detailed Implementation

[0085] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0086] In the embodiments of this application, the terms "first" and "second" are used to distinguish identical or similar items with substantially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, nor do they necessarily imply difference. It should be noted that in the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design scheme described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner. In the embodiments of this application, "at least one" refers to one or more, and "more than one" refers to two or more.

[0087] It should be noted that the phrase "at...time" in the embodiments of this application can refer to the instant at which a certain situation occurs, or to a period of time after the occurrence of a certain situation; the embodiments of this application do not specifically limit this. Furthermore, 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 this application are merely examples; the control method for rapid screening and enrichment of aerobic granular sludge may also include more or fewer elements.

[0088] To facilitate a clear description of the technical solutions in the embodiments of this application, some terms and technologies involved in the embodiments of this application will be briefly introduced below:

[0089] Aerobic granular sludge (AGS): Aerobic granular sludge is a granular activated sludge formed through microbial self-aggregation. It has a dense structure, good settling properties, and excellent decontamination capabilities. It is typically produced using a sequencing batch reactor (SBR).

[0090] Feeding and starving zones: In the entire biochemical treatment unit, the area where microorganisms grow on an external substrate is called the feeding zone, and the area where they grow on an internal substrate is called the starving zone. Under this alternating feeding-starving condition, microorganisms secrete a large amount of extracellular polymeric substances (EPS). These EPS, retained within the reactor, promote particle aggregation and adsorption, accelerating the formation of granular sludge. The alternation of feeding-starving conditions inhibits the reproduction of filamentous microorganisms while favoring the growth of flocculant bacteria.

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

[0092] However, unlike sequencing batch reactors, continuous flow reactors cannot apply selective pressure to activated sludge by gradually reducing sludge settling time. As a result, sludge with good settling performance is lost during sludge discharge, while flocculent sludge with poor settling performance is returned to the front end of the anaerobic tank and dominates in the competition for carbon sources in the influent. Granular sludge with good settling performance cannot store and absorb sufficient organic matter to grow rapidly. Therefore, it is difficult to quickly achieve sludge granulation and stable operation of granular sludge systems in continuous flow reactors, which has resulted in no substantial breakthrough in the promotion and application of AGS in the continuous flow field.

[0093] In existing technologies, some studies have further enhanced the gravity selective 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 returning granular sludge from different stages in stages. However, it is suitable for wastewater treatment plants with small treatment scales and the control of sludge return is relatively complicated.

[0094] Some studies have shown that adjusting the height of the movable baffle can flexibly adjust the applied settling selective pressure to achieve the screening effect on sludge. However, 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 sludge separation 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 be dynamically adjusted according to the granulation process to improve the sludge selection effect.

[0096] The existing continuous flow sedimentation tank structure cannot achieve continuous and effective screening of heavy sludge and light sludge in practical engineering applications, thus failing to promote rapid granulation and resulting in poor efficiency in the rapid screening and enrichment of aerobic granular sludge.

[0097] Based on this, in order to solve the above-mentioned technical problems, embodiments of this application provide a method for controlling the rapid screening and enrichment of aerobic granular sludge and a continuous flow reaction system, which can be used in the field of wastewater treatment. The inventive concept of this application lies in: how to effectively improve the efficiency of rapid screening and enrichment of aerobic granular sludge.

[0098] Optionally, embodiments of this application provide a continuous flow reaction system for aerobic granular sludge, including: an anaerobic zone, an anoxic zone, an aerobic zone, a sedimentation device, and a reflux device, wherein the areas where the anaerobic zone, anoxic zone, and aerobic zone are located are divided into a saturated zone and a starved zone.

[0099] Both the anaerobic and anoxic zones include multiple chambers, partitions, water passages, and agitators; each chamber contains one agitator. 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 scraper. The guide plate is located between the middle and top of the sedimentation device's inlet end; the primary sludge return hopper is located at the bottom of the sedimentation device's inlet end; the secondary sludge return hopper is located at the bottom of the sedimentation device's outlet end; and the scraper is located in the sludge sedimentation zone in the middle of the sedimentation device. The return system includes a nitrification liquor return device, a primary sludge return device, and a secondary sludge return device. The nitrification liquor return device is connected at both ends to the aerobic, anaerobic, and anoxic zones, respectively. The primary sludge return device is connected at both ends to the primary sludge return hopper and the anaerobic zone, respectively. The secondary sludge return device is connected at both ends to the secondary sludge return hopper and the anoxic zone, respectively.

[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. Each partition wall 111 is provided with one upper and one lower water passage hole in sequence, and each chamber is connected in sequence through the water passage hole.

[0101] Specifically, the number of chambers can be determined based on the volume of the anaerobic and anoxic zones.

[0102] Specifically, each chamber in the anaerobic and anoxic zones is equipped with a stirrer 116, which can adjust the dissolved oxygen levels in the anaerobic and anoxic zones by adjusting the stirring rate.

[0103] Optionally, multiple adjacent chambers can form an anaerobic zone, and multiple adjacent chambers can form an anoxic zone. Specifically, in Figure 1 In the middle, 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) are the anaerobic zone, 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) are the anoxic zone.

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

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

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

[0107] Specifically, the baffle 131 can prevent short-circuiting of the influent and increase the height-to-diameter ratio of a single tank, providing stronger hydraulic shear force to the mud-water mixture in the aerobic tank through rising aeration.

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

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

[0110] The bottom left corner shows the sedimentation device, which includes: a guide plate 141 (see...). Figure 2 (as shown), primary sludge return sludge hopper 142, secondary sludge return sludge hopper 143, sludge sedimentation zone 144, and sludge scraping device 145.

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

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

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

[0114] The inlet of the primary sludge return device is located at the bottom of the primary sludge return hopper 142, the outlet of the primary sludge return device is located at the inlet of the anaerobic zone, the inlet of the secondary sludge return device is located at the bottom of the secondary sludge return hopper 143, and the 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 adopt diaphragm pump return. The diaphragm pump can reduce the damage to the granular sludge structure caused by mechanical return. Compared with the airlift return method, it can also greatly reduce the amount of dissolved oxygen entering the front-end anaerobic zone and destroying the anaerobic environment.

[0116] Specifically, ordinary wastewater treatment plants have only one sludge return system. However, since the influent organic matter concentration of general municipal systems is low and the influent organic matter of continuous flow systems is diluted in large quantities, in order to ensure the food-to-microbe ratio during the saturation stage, the primary sludge return device provided in this application mainly returns sludge with good settling performance at the front end of the sludge settling zone 144 to the front end of the anaerobic zone for full organic matter absorption.

[0117] Furthermore, considering that too little sludge is returned from the saturated zone, which may lead to a decrease in the overall sludge concentration of the system and thus affect the denitrification and phosphorus removal efficiency of the downstream system, in order to ensure the basic denitrification and phosphorus removal functions during the cultivation of granular sludge, a secondary sludge return device is used to return part of the sludge in the downstream sludge hopper to the starving zone, so as to reduce the impact on the denitrification efficiency of the starving zone and the nitrification efficiency of the aerobic zone.

[0118] It should be noted that the continuous flow reaction system for 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 return device 151, the primary sludge return device, and the secondary sludge return device, as well as the solenoid valves on the return branches. The intelligent control device 160 is used to regulate the start and stop of the return pumps, the return flow rate, and the opening and closing of the solenoid valves.

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

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

[0123] The online monitoring equipment includes: an online COD monitor, an online ammonia nitrogen detector, and an online influent flow meter installed on the influent pipe at the front end of the anaerobic zone; an online sludge concentration meter installed at the bottom of the first chamber 112 and the first aerobic tank 132 in the anaerobic zone; an online sludge concentration meter and a sludge level gauge 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 saturated zone and the first chamber of the starving zone; an online ammonia nitrogen monitor installed at the effluent end of the aerobic zone; a DO meter, a pH meter, and an ORP meter installed at the influent ends of the anaerobic zone, the anoxic zone, and the aerobic zone; and online flow meters installed on the return pipe 1517, the primary return pipe 1421, and the secondary return pipe 1431.

[0124] In addition, the air intake of each aerobic tank in the aerobic zone is individually controlled by a 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 to be between 1.5 and 4.5 mg / L, and gradually decreases along the flow path. At the same time, the intelligent control device 160 can further adjust the DO in the aeration tank based on the online monitoring data of ammonia nitrogen at the effluent end of the aerobic zone, which can greatly reduce the aeration energy consumption in the sewage treatment process.

[0125] In this embodiment, the multi-chamber configuration allows the influent to exhibit a plug flow pattern throughout its flow path, while ensuring thorough mixing of mud and water within each chamber. This enhances the absorption and storage of organic matter in the influent by microorganisms in the anaerobic and anoxic zones at the front end, reduces the system's saturation-starvation ratio, and promotes the rapid enrichment of functional microorganisms such as denitrifying polyphosphate bacteria and denitrifying polysaccharide bacteria.

[0126] Figure 2 A schematic diagram of the structure of a continuous flow reaction system for aerobic granular sludge provided in this application embodiment. Figure 2 The areas containing the anaerobic, hypoxic, and aerobic zones are further divided into satiated and starved zones, 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 zone 144, and a sludge scraping device 145.

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

[0128] The guide plate 141 is located 0.5 to 1.0 m from the inlet of the sedimentation device, with a submersion depth of 0.3 to 0.5 m and a height of 0.1 to 0.15 m above the water surface; the primary sludge return hopper 142 is located at the bottom of the inlet of the sedimentation device; the secondary sludge return hopper 143 is located at the bottom of the outlet of the sedimentation device; the sludge sedimentation zone 144 is located in the middle of the sedimentation device; and the sludge scraping device 145 is located in the sludge sedimentation zone 144.

[0129] The bottom of the primary sludge return hopper 142 is equipped with a primary return pipe 1421 and a primary vent pipe 1422.

[0130] Specifically, the primary return pipe 1421 of the primary sludge return hopper 142 is used to return the sludge at the front end of the sludge settling zone 144 to the inlet end of the anaerobic zone.

[0131] The bottom of the secondary sludge return hopper 143 is equipped with a secondary return pipe 1431 and a secondary vent pipe 1432.

[0132] Specifically, the secondary return pipe 1431 of the secondary sludge return hopper 143 is used to return the sludge from the effluent end of the sludge settling zone 144 to the front end of the starvation zone, and the secondary vent pipe 1432 of the secondary sludge return hopper 143 is used to discharge excess sludge and serve as the system's sludge discharge pipe.

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

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

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

[0136] The mud scraping component 1452 includes: a mud scraper 14521, a mud scraper lifting motor 14522, and a mud scraper angle adjusting motor 14523.

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

[0138] Driven by the geared motor 14511, the transmission main wheel 14512 drives the scraper 14521 to perform scraping motion via the transmission chain 14513 and the transmission pulley 14514.

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

[0140] It should also be noted that the bidirectional sludge scraper's operating trajectory is as follows:

[0141] Specifically, the sludge scraping component 1452 moves back and forth and flips on the track groove 1453 under the traction of the transmission device 1451. When scraping sludge, it first moves from the initial position toward the primary sludge return sludge hopper 142, scraping the activated sludge with good settling performance at the front end into the primary sludge return sludge hopper 142. After scraping, it returns to the initial position and then moves in the opposite direction to scrape the remaining sludge at the rear end of the sedimentation zone into the secondary sludge return sludge hopper 143.

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

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

[0144] Specifically, if granular sludge is approximated as spherical particles, its settling rate during free settling 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 and ρ' are the densities of the particles and water, respectively, in g / cm³; g is the acceleration due to gravity, in cm / s². 2 μ is the adhesion coefficient of water, in Pa·s; d is the particle diameter, in cm.

[0147] Specifically, the greater the particle density and diameter, the greater the settling velocity of the particles in the vertical direction. The horizontal velocity of the particles is mainly affected by the influent flow rate. Therefore, in a horizontal flow sedimentation tank, sludge with larger particle density and diameter is closer to the influent end, while sludge with smaller particle density and diameter is closer to the effluent end. Based on this principle, a sludge settling hopper is installed at both the influent and effluent ends of the sedimentation tank. A scraper scrapes sludge with good settling performance and large particle size from the front end to the front hopper (primary sludge return hopper 142) and returns it to the anaerobic tank influent end. This portion of sludge can fully absorb organic matter from the influent and rapidly accumulate. Sludge with slightly poorer settling performance is scraped to the effluent hopper (secondary sludge return hopper 143). Part of it is returned to the starved zone through the secondary return pipe to replenish the system's sludge volume, and the other part is discharged through the sludge discharge pipe.

[0148] In this embodiment, the different natural settling rates of sludge particles of different sizes in the sludge settling zone are utilized to simply modify the traditional unidirectional sludge scraper into a bidirectional sludge scraper. The running trajectory of the sludge scraper is controlled by an intelligent control device, which returns sludge with good settling performance and discharges sludge with poor settling performance, providing settling selection pressure for the formation of granular sludge, and realizing the dual functions of sludge settling and granular sludge screening.

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

[0150] The nitrification liquid reflux device 151 adopts air-lift reflux, which changes the partial pressure of each phase in the wastewater by injecting gas, thereby promoting the separation and removal of pollutants.

[0151] Among them, the inlet 1513 is located at the bottom of the outlet end of the aerobic zone.

[0152] The slope of the horizontal return pipe connected to the deoxygenation box 1515 is designed to be 1% to 3% to ensure that the return nitrified liquid flows into the anoxic zone by gravity.

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

[0154] For example, the return pipe 1517 returns the nitrified liquid 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 return branch pipe 15171, the second return branch pipe 15172, the third return branch pipe 15173, and the fourth return branch pipe 15174, respectively. Each branch pipe is equipped with a solenoid valve, and each solenoid valve is used to control the return of the nitrified liquid. The hydraulic retention time of the anaerobic zone and the anoxic zone can be adjusted by starting and stopping the solenoid valve.

[0155] Specifically, in the early stage of granular sludge cultivation, it is necessary to rapidly enrich anaerobic functional bacteria. However, the growth cycle of functional bacteria such as denitrifying polyphosphate bacteria and denitrifying polysaccharide bacteria is relatively long. Therefore, in the early stage of cultivation, the hydraulic retention time in the anaerobic zone can be appropriately increased and the hydraulic retention time in the anoxic zone can be reduced. In the later stage of cultivation, in order to improve the efficiency of simultaneous nitrification and denitrification in the anoxic zone, the hydraulic retention time in 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. During operation, the hydraulic residence time of the anaerobic and anoxic zones can be adjusted by changing the reflux point of the mixed liquor reflux ratio and in combination with the stirring rate of the agitator.

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

[0158] For example, the nitrified liquid can be returned to each anoxic tank by adjusting the opening and closing degree of the inlet valves on the return branch pipes of the first chamber 121, the second chamber 122, and the third chamber 123 of the anoxic zone.

[0159] In addition, the hydraulic retention time in each chamber of the anaerobic and anoxic zones is controlled at 15–30 minutes.

[0160] Optionally, the system further includes an intelligent control device; the intelligent control device is signal-connected to the agitator and is used to control the switching on and off of the agitator and the agitation rate; the intelligent control device is signal-connected to the sludge scraping device and is used to adjust the initial position and scraping frequency of the sludge scraping device; the intelligent control device is signal-connected to the online monitoring equipment of the anaerobic zone, anoxic zone, aerobic zone, and sedimentation device respectively; and the intelligent control device is signal-connected to the reflux pump of the reflux device and is used to adjust the switching on and off of the reflux pump and the reflux flow rate.

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

[0162] S401. Divide the sludge settling zone according to the preset conditions, and determine the initial position of the sludge scraper in the sludge settling zone according to the preset conditions.

[0163] In this embodiment, before the aerobic granular sludge continuous flow reaction system is put into operation, the sludge settling zone is first divided according to preset conditions, and then the initial position of the sludge scraper in the sludge settling zone is determined according to preset conditions.

[0164] Specifically, when the sludge scraping device is in this initial position, it ensures that the amount of sludge in the primary and secondary sludge return hoppers is sufficient to meet the stable operation of the primary and secondary sludge return devices. This means that during stable operation, the sludge level in the primary and secondary sludge return hoppers remains within a preset range, and the amount of sludge is sufficient to continuously supply sludge to the primary and secondary sludge return hoppers during the scraping process, without exceeding the hopper capacity.

[0165] S402. Install the sludge scraper in the initial position.

[0166] S403. Adjust the primary sludge return flow rate and the secondary sludge return flow rate according to the preset first sludge concentration range and the second sludge concentration range.

[0167] In this embodiment, during the formal operation of the aerobic granular sludge continuous flow reaction system, it is necessary to adjust 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 operation stable.

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

[0169] Among them, the sludge return flow rate is either the primary sludge return flow rate or the secondary sludge return flow rate.

[0170] In this embodiment, when the influent water quality or quantity fluctuates significantly, causing large fluctuations in sludge return flow, or when the settling performance of activated sludge changes significantly during the cultivation process, resulting in changes in the sludge distribution at the bottom of the sedimentation tank, thus causing the initial position or scraping frequency parameters of the scraper to fail to meet the requirements for stable operation of the primary and secondary return systems, the intelligent control device of the aerobic granular sludge continuous flow reaction system periodically adjusts the scraping device based on the scraping action of the scraping device and the liquid level sensors in the primary and secondary sludge return hoppers.

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

[0172] This embodiment provides a method for controlling the rapid screening and enrichment of aerobic granular sludge and a continuous flow reaction system. The method is applied to a continuous flow reaction system for aerobic granular sludge, which includes a scraping device. The system divides the sludge settling zone according to preset conditions and determines the initial position of the scraping device within the settling zone. The scraping device is installed at the initial position. The primary and secondary sludge return flows are controlled according to preset first and second sludge concentration ranges. When the sludge return flow changes with influent water quality or flow rate, the scraping device is adjusted based on its scraping action. Compared to existing technologies that cannot achieve continuous and effective screening of heavy and light sludge in practical engineering applications, resulting in the inability to promote rapid granulation and thus affecting the efficiency of rapid screening and enrichment of aerobic granular sludge, this method addresses the limitations of existing technologies. This application utilizes the sedimentation characteristics of a horizontal flow sedimentation tank to simply modify a traditional unidirectional sludge scraper into a bidirectional sludge scraper. This allows for the return of sludge with good sedimentation performance and the discharge of sludge with poor sedimentation performance, thereby providing settling selection pressure for the formation of granular sludge in the continuous flow system. This achieves the dual functions of sludge settling and granular sludge screening, ensuring system stability, promoting the rapid enrichment and growth of aerobic granular sludge, accelerating the granulation process, and thus improving the efficiency of rapid screening and enrichment of aerobic granular sludge.

[0173] Figure 5 A flowchart illustrating a method for rapid screening and enrichment of aerobic granular sludge provided in this application embodiment. Figure 2 ,exist Figure 4 Based on the embodiments, such as Figure 5 As shown, the specific implementation steps of S404 above include:

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

[0175] The sludge liquid height range includes both the lowest and highest sludge liquid levels.

[0176] Specifically, the preset minimum sludge liquid level is just enough to ensure a continuous supply of sludge in the primary and secondary sludge return hoppers during the sludge scraping process.

[0177] More specifically, during the cultivation of the aerobic granular sludge continuous flow reaction system, as functional microorganisms accumulate and granular sludge gradually forms, the food-to-microorganism ratio in the reaction zone needs to be adjusted periodically, which also means that the sludge return ratio needs to be adjusted synchronously. Furthermore, as the overall sludge settling performance improves and the sludge sedimentation distribution in the sedimentation zone changes, the initial position or scraping frequency parameters of the scraper may not meet the requirements for stable operation of the return system. Therefore, the intelligent control device periodically adjusts the initial position of the scraper, moving it left or right by 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 level is lower than the minimum sludge liquid level, move the sludge scraper in the opposite direction to the sludge return hopper until the current sludge liquid level is within the sludge liquid level range.

[0179] S503. When the current sludge liquid level is higher than the highest sludge liquid level, move the sludge scraper towards the sludge return hopper until the current sludge liquid level is within the sludge liquid level range.

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

[0181] Figure 6 A flowchart illustrating a method for rapid screening and enrichment of aerobic granular sludge provided in this application embodiment. Figure 3 ,exist Figure 5 and Figure 4 Based on the embodiments, such as Figure 6 As shown, the continuous flow reaction system for aerobic granular sludge includes: an anaerobic zone, an anoxic zone, an aerobic zone, and an intelligent control device; the anaerobic zone, anoxic zone, and aerobic zone are divided into a saturated zone and a starved zone; therefore, the specific implementation steps of the above S403 include:

[0182] S601. The intelligent control device collects the sludge concentration in the saturated zone, the sludge concentration at the bottom of the primary sludge return hopper, and the current influent flow rate in real time.

[0183] S602. Based on the sludge concentration in the saturated zone, the sludge concentration at the bottom of the primary stage, and the current influent flow rate, calculate the primary sludge return flow rate of the primary sludge return hopper.

[0184] The calculation formula is:

[0185]

[0186] Where L1 is the primary sludge return flow rate; M1 is the sludge concentration in the saturated zone; M3 is the primary bottom sludge concentration; Q is the current influent flow rate; and a1 is the ratio of the primary sludge return concentration to the primary bottom sludge concentration in the primary sludge return hopper.

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

[0188] S603. Based on the preset first sludge concentration range, the first-level bottom sludge concentration of the first-level sludge return hopper, and the current influent flow rate, calculate the first-level sludge return flow rate range of the first-level sludge return hopper.

[0189] In this embodiment, during the cultivation of granular sludge, it is necessary to maintain the concentration of the first sludge in the saturation zone within the range of 3 to 3.5 mg / L. Specifically, this can be achieved by adjusting the flow rate of the first sludge in the first sludge return hopper.

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

[0191] S604. Adjust the primary sludge return flow rate 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.

[0192] In this embodiment, the two-stage sludge return strategy ensures both the screening of returned sludge and the maintenance of system stability. The first-stage sludge return ensures that sludge with good settling properties can be preferentially returned to the front-end anaerobic tank and absorb organic matter in the influent, grow rapidly and accumulate, thereby improving the control efficiency of rapid screening and accumulation of aerobic granular sludge.

[0193] Figure 7 A flowchart illustrating a method for rapid screening and enrichment of aerobic granular sludge provided in this application embodiment. Figure 4 ,exist Figure 4 , Figure 5 and Figure 6 Based on the embodiments, such as Figure 7 As shown, the specific implementation steps of S403 above also include:

[0194] S701: The intelligent control device collects the sludge concentration in the starving zone, the sludge concentration in the saturated zone, the primary bottom sludge concentration, the secondary bottom sludge concentration in the secondary sludge return hopper, and the current influent flow rate in real time.

[0195] S702. Based on the sludge concentration in the starving 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 flow rate of the secondary sludge return hopper.

[0196] The calculation formula is:

[0197]

[0198] Where R1 is the primary sludge return ratio; L2 is the secondary sludge return flow rate; M2 is the sludge concentration in the starvation zone; M4 is the secondary bottom sludge concentration; and a2 is the ratio of the secondary sludge return concentration to the secondary bottom sludge concentration in the secondary sludge return hopper.

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

[0200] S703. Based on the preset second sludge concentration range, sludge concentration in the saturated zone, primary bottom sludge concentration, secondary bottom sludge concentration, and current influent flow rate, calculate the secondary sludge return flow rate range of the secondary sludge return hopper.

[0201] In this embodiment, during the granular sludge cultivation process, it is necessary to maintain the concentration of the second sludge in the starvation zone within the range of 4 to 5 mg / L. Specifically, this can be achieved by adjusting the secondary sludge return flow rate in the secondary sludge return hopper.

[0202] S704. Adjust the secondary sludge return flow rate according to the range of the secondary sludge return flow rate until the secondary sludge return flow rate is within the range of the secondary sludge return flow rate.

[0203] In this embodiment, the two-stage sludge return strategy ensures both the screening of returned sludge and the maintenance of system stability. The secondary sludge return maintains the stability of the system's sludge concentration, thereby ensuring the sustainability of the system's basic nitrogen and phosphorus removal functions and improving the control efficiency of rapid screening and enrichment of aerobic granular sludge.

[0204] Figure 8 A flowchart illustrating a method for rapid screening and enrichment of aerobic granular sludge provided in this application embodiment. Figure 5 ,exist Figure 4 , Figure 5 , Figure 6 and Figure 7 Based on the embodiments, such as Figure 8 As shown, the preset conditions include: hydraulic retention time, a first sludge concentration range, and a second sludge concentration range. Therefore, the specific implementation steps of S401 above include:

[0205] S801. Based on the hydraulic retention time, the sludge sedimentation zone is divided into multiple sections, and each scraper device is adjusted and installed at the end of each section.

[0206] In this embodiment, the sludge settling zone is divided into n intervals according to its size. The hydraulic retention time of each interval is controlled to be 5 to 10 minutes. The sludge scraper is started at the beginning of operation. Before the formal start, the initial position of the sludge scraper is adjusted to the end of each interval.

[0207] S802. Start the sludge scraping device and adjust its initial position according to the first sludge concentration range and the second sludge concentration range, so that the primary sludge return flow rate is within the primary sludge return flow rate range, the secondary sludge return flow rate is within the secondary sludge return flow rate range, and the sludge level in the return sludge hopper is stable within the preset sludge level height range.

[0208] In this embodiment, the particle size distribution of activated sludge in the sludge settling zone during the initial startup phase is detected by an intelligent control device. The position and scraping frequency of the scraper during the initial operation phase are determined based on the sludge return flow rate during system startup. This ensures that the amount of sludge in the sludge return hopper after the scraper is started at this position at regular intervals can meet the stable operation of the primary and secondary sludge return systems. In other words, it ensures that the sludge level in the primary and secondary sludge return hoppers is always within the set range, and that the amount of sludge in the hoppers can meet the continuous supply of sludge in the primary and secondary sludge return hoppers during the scraping process without exceeding the hopper capacity.

[0209] Specifically:

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

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

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

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

[0214] In this embodiment, by utilizing the different natural settling rates of sludge particles of different sizes in the sludge settling zone, the traditional unidirectional scraper is simply modified into a bidirectional scraper. The running trajectory of the scraper is controlled by an intelligent control device, which returns sludge with good settling performance and discharges sludge with poor settling performance, providing settling selection pressure for the formation of granular sludge. At the same time, it realizes the dual functions of sludge settling and granular sludge screening, thereby improving the control efficiency of rapid screening and enrichment of aerobic granular sludge.

[0215] The technical solutions of this application have been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it is readily understood by those skilled in the art that the scope of protection of this application is obviously not limited to these specific embodiments. The above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A continuous flow reaction system of aerobic granular sludge, characterized by, The system comprises an anaerobic zone, an anoxic zone, an aerobic zone, a sedimentation device and a reflux device; The anaerobic zone and the anoxic zone each comprise a plurality of chambers, a plurality of partition walls, a plurality of water passing holes and a plurality of stirrers; one stirrer is arranged in each chamber; The aerobic zone comprises a plurality of aerobic tanks, a baffle and a microporous aeration device; The sedimentation device comprises a flow guide plate, a primary sludge reflux hopper, a secondary sludge reflux hopper, a sludge sedimentation zone and a sludge scraping device; the flow guide plate is arranged between the middle and the top of the water inlet end of the sedimentation device, the primary sludge reflux hopper is arranged at the bottom of the water inlet end of the sedimentation device, the secondary sludge reflux 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 zone in the middle of the sedimentation device; The reflux device comprises 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 connected with the aerobic zone, the anaerobic zone and the anoxic zone respectively; the two ends of the primary sludge reflux device are connected with the primary sludge reflux hopper and the anaerobic zone respectively; and the two ends of the secondary sludge reflux device are connected with the secondary sludge reflux hopper and the anoxic zone respectively; The sludge scraping device is a bidirectional sludge scraper, which scrapes sludge with good settling performance and large particle size to the primary sludge reflux hopper and scrapes sludge with poor settling performance to the secondary sludge reflux hopper.

2. The system of claim 1, wherein, The sludge scraping device comprises a transmission device, a sludge scraping component and a track groove; The transmission device comprises a speed reducer, a transmission main wheel, a transmission chain and a transmission pulley; The sludge scraping component comprises a sludge scraping plate, a sludge scraping plate lifting motor and a sludge scraping plate angle adjusting motor; Under the driving of the speed reducer, the transmission main wheel drives the sludge scraping plate to move by the transmission chain and the transmission pulley; when the sludge scraping plate lifting motor lifts the sludge scraping plate, the sludge scraping plate angle adjusting motor adjusts the angle of the sludge scraping plate.

3. The system of claim 2, wherein, The nitrification liquid reflux device comprises an aeration device, an air inlet pipe, a water inlet, a sewage lifting pipe, an oxygen removal box, a flow blocking cover and a reflux pipe; The reflux pipe communicates the chambers of the anaerobic zone and the anoxic zone through the reflux branch pipes; An electromagnetic valve is arranged on each reflux branch pipe, and each electromagnetic valve is used to control the reflux of nitrification liquid, so as to adjust the hydraulic retention time of the anaerobic zone and the anoxic zone.

4. The system of claim 3, wherein, 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 sludge inlet of the primary sludge reflux device is located at the bottom of the primary sludge reflux hopper, the sludge outlet of the primary sludge reflux device is located at the water inlet end of the anaerobic zone, the sludge inlet of the secondary sludge reflux device is located at the bottom of the secondary sludge reflux hopper, and the sludge outlet of the secondary sludge reflux device is located at the first chamber of the hunger zone; The bottom of each of the primary sludge reflux hopper and the secondary sludge reflux hopper is provided with the reflux pipe and a vent pipe. The return pipe of the primary sludge return hopper is used to return the sludge at the influent 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 effluent 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 of claim 4, wherein, The system further comprises an intelligent control device; The intelligent control device is in signal connection with the agitator, and is used to control the switching and stirring rate of the agitator; The intelligent control device is in signal connection with the sludge scraping device, and is used to adjust the initial position and sludge scraping frequency of the sludge scraping device; The intelligent control device is in signal connection with the online monitoring equipment of the anaerobic zone, the anoxic zone, the aerobic zone and the sedimentation device respectively; The intelligent control device is in signal connection with the return pump of the return device, and is used to adjust the switching and return flow of the return pump.

6. A method for regulating the rapid selection and enrichment of aerobic granular sludge, characterized in that, The method comprises the following steps: According to the preset conditions, the sludge sedimentation zone is divided, and the initial position of the sludge scraping device in the sludge sedimentation zone is determined according to the preset conditions; The sludge scraping device is installed at the initial position; According to the preset first sludge concentration range and second sludge concentration range, the primary sludge return flow and the secondary sludge return flow are regulated; the area where the anaerobic zone, the anoxic zone and the aerobic zone of the system are located is divided into a satiation zone and a starvation zone; the first sludge concentration is the sludge concentration of the satiation zone, and the second sludge concentration is the sludge concentration of the starvation zone; When the sludge return flow changes with the change of the influent water quality, the influent amount or the sludge settling performance, and the sludge liquid level of the return hopper exceeds the preset sludge liquid level height range in long-term operation, the sludge scraping device is adjusted according to the sludge scraping action of the sludge scraping device, wherein the sludge return flow is the primary sludge return flow or the secondary sludge return flow.

7. The method of claim 6, wherein, The sludge scraping action comprises a primary sludge scraping action and a secondary sludge scraping action; the primary sludge scraping action refers to the action of the sludge scraping plate scraping sludge from the initial position to the primary sludge return hopper; the secondary sludge scraping action refers to the action of the sludge scraping plate scraping sludge from the initial position to the secondary sludge return hopper.

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

9. The method of claim 8, wherein, The continuous flow reaction system of the 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 regulation of the first-stage sludge reflux flow and the second-stage sludge reflux flow according to the preset first sludge concentration range and the second sludge concentration range comprises: The intelligent control device is used to collect the satiation zone sludge concentration, the first-stage sludge reflux hopper first-stage bottom sludge concentration, and the current water inflow in real time; The first-stage sludge reflux flow of the first-stage sludge reflux hopper is calculated according to the satiation zone sludge concentration, the first-stage bottom sludge concentration, and the current water inflow; The first-stage sludge reflux flow range of the first-stage sludge reflux hopper is calculated according to the preset first sludge concentration range, the first-stage bottom sludge concentration of the first-stage sludge reflux hopper, and the current water inflow; The first-stage sludge reflux flow is regulated according to the first-stage sludge reflux flow range until the first-stage sludge reflux flow is within the first-stage sludge reflux flow range.

10. The method of claim 9, wherein, The regulation of the first-stage sludge reflux flow and the second-stage sludge reflux flow according to the preset first sludge concentration range and the second sludge concentration range further comprises: The intelligent control device is used to collect the hunger zone sludge concentration, the satiation zone sludge concentration, the first-stage sludge reflux hopper first-stage bottom sludge concentration, the second-stage sludge reflux hopper second-stage bottom sludge concentration, and the current water inflow in real time; The second-stage sludge reflux flow of the second-stage sludge reflux hopper is calculated according to the hunger zone sludge concentration, the satiation zone sludge concentration, the first-stage bottom sludge concentration, the second-stage bottom sludge concentration, and the current water inflow; The second-stage sludge reflux flow range of the second-stage sludge reflux hopper is calculated according to the preset second sludge concentration range, the satiation zone sludge concentration, the first-stage bottom sludge concentration, the second-stage bottom sludge concentration, and the current water inflow; The second-stage sludge reflux flow is regulated according to the second-stage sludge reflux flow range until the second-stage sludge reflux flow is within the second-stage sludge reflux flow range.

11. The method of claim 10, wherein, The first-stage sludge reflux flow of the first-stage sludge reflux hopper is calculated according to the satiation zone sludge concentration, the first-stage bottom sludge concentration, and the current water inflow, and the calculation formula is: wherein, is the primary sludge return flow rate; is the full zone sludge concentration; is the primary bottom sludge concentration; is the current influent flow rate; is the ratio of the primary sludge return tank primary sludge return concentration to the primary bottom sludge concentration; The second-stage sludge reflux flow of the second-stage sludge reflux hopper is calculated according to the hunger zone sludge concentration, the satiation zone sludge concentration, the first-stage bottom sludge concentration, the second-stage bottom sludge concentration, and the current water inflow, and the calculation formula is: wherein, is the primary sludge return ratio; is the secondary sludge return amount; is the starved zone sludge concentration; is the secondary bottom sludge concentration; is the ratio of the secondary sludge return concentration of the secondary sludge return hopper to the secondary bottom sludge concentration.

12. The method of claim 6, wherein, The preset conditions include: a hydraulic retention time, the first sludge concentration range and the second sludge concentration range; The preset conditions include: a hydraulic retention time, the first sludge concentration range and the second sludge concentration range; According to the hydraulic retention time, the sludge sedimentation zone is divided into multiple intervals, and each of the sludge scraping devices is respectively adjusted and installed at the end of each interval; The sludge scraping devices are started, and the initial positions of the sludge scraping devices are adjusted according to the first sludge concentration range and the second sludge concentration range, so that the primary sludge return flow is within the primary sludge return flow range, the secondary sludge return flow is within the secondary sludge return flow range, and the sludge liquid level of the reflux sludge hopper is stable within the preset sludge liquid level height range.

13. The method of claim 12, wherein, According to the first sludge concentration range and the second sludge concentration range, the initial positions of the sludge scraping devices are adjusted, including: When the primary sludge return flow is lower than the minimum flow of the primary sludge return flow range, the initial position of the sludge scraping device is moved in the direction opposite to the primary sludge reflux sludge hopper; When the primary sludge return flow is higher than the maximum flow of the primary sludge return flow range, the initial position of the sludge scraping device is moved in the direction of the primary sludge reflux sludge hopper; When the secondary sludge return flow is lower than the minimum flow of the secondary sludge return flow range, the initial position of the sludge scraping device is moved in the direction opposite to the secondary sludge reflux sludge hopper; When the secondary sludge return flow is higher than the maximum flow of the secondary sludge return flow range, the initial position of the sludge scraping device is moved in the direction of the secondary sludge reflux sludge hopper.

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