Self-supplying vertical flow sewage treatment device and sewage treatment process

Abstract

The present application relates to a self-supply vertical flow sewage treatment device and sewage treatment process, comprising: a sewage treatment device body, a sludge leading-out device, and a backflow device; the sewage treatment device body is used for leading in sewage and generating granulated sludge; the sludge leading-out device is partially embedded in the bottom end of the sewage treatment device body and is used for leading out sludge of a target particle size; and the backflow device is in communication with the sludge leading-out device and the sewage treatment device body and is used for backflowing sludge of the target particle size. The present application uses conventional sewage as the water inlet source, self-cultures sludge of a specific target particle size in the reactor, backflows the sludge to the reactor at an appropriate time for recycling, and thus improves the self-supply capacity of the reactor and the sewage treatment effect.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, and particularly relates to a self-supplying vertical flow wastewater processor and wastewater treatment process. Background Technology

[0002] In the field of biological nitrogen removal from wastewater, some nitrification-anaerobic ammonium oxidation (PNA) technologies have attracted much attention due to their advantages such as not requiring organic carbon sources and low energy consumption. PNA achieves nitrogen removal through a two-stage reaction. First, ammonia-oxidizing bacteria (AOB) convert some ammonia nitrogen into nitrite under limited oxygen conditions. Next, anaerobic ammonia oxidizing bacteria (AnAOB) will... and This technology directly generates N2 from the substrate. However, its practical application faces significant challenges: stringent requirements for dissolved oxygen (DO) control (which can easily lead to over-nitrification or nitrite deficiency), low-temperature sensitivity (AnAOB activity drops sharply below 15°C), and weak sludge retention capacity (AnAOB grows slowly and is easily lost), resulting in poor system stability and a long start-up period (usually more than 6 months).

[0003] To address the aforementioned issues, Chinese patent application CN117069266A discloses a wastewater treatment device that promotes sludge granulation and enhances biomass retention through internal gas circulation and upward flow velocity regulation, achieving good nitrogen and phosphorus removal effects. However, the remaining sludge is discharged directly without treatment, resulting in defects such as insufficient particle classification capacity (lack of dynamic screening structure) and imbalance in functional microbial community competition (mixed growth of heterotrophic and autotrophic bacteria). This leads to a dispersed particle size distribution (0.1-2 mm) and a low AnAOB ratio (usually <30%) in the granular sludge, making it difficult to achieve targeted enrichment and recovery of high-purity anaerobic ammonia oxidation granular sludge, thus causing waste.

[0004] It is evident that current processes focus primarily on improving nitrogen removal efficiency, while neglecting the resource utilization attributes of granular sludge. Mature anaerobic ammonia oxidation granular sludge, due to its high activity (≥0.4kgN / (kgVSS·d)), strong stress resistance, and storability, can be directly used as a bio-enhancing agent for wastewater treatment plant inoculation, with a value that can reach 5-8 times that of conventional activated sludge.

[0005] Therefore, how to provide a reactor that enhances biological denitrification while enabling the self-filling and reuse of granular sludge in the reactor, thereby achieving the recycling of microbial resources and reducing wastewater treatment costs, is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] To solve at least one of the above-mentioned technical problems, the present invention provides a self-supplying vertical flow sewage processor, comprising a sewage processor body, a sludge discharge device, and a return device.

[0007] The wastewater treatment unit is used to introduce wastewater and produce granular sludge;

[0008] The sludge removal device is partially embedded in the bottom of the wastewater treatment unit and is used to remove sludge particles of the target particle size.

[0009] The reflux device is connected to the sludge discharge device and the wastewater treatment unit, and is used to reflux sludge of the target particle size.

[0010] Furthermore, this includes recycling components, monitoring components, and control components;

[0011] The recycling component, connected to the sludge discharge device, is used to store and return sludge of the target particle size.

[0012] The monitoring component is installed inside the reaction chamber of the wastewater treatment unit and is used to monitor wastewater indicators.

[0013] The control component, connected to the recovery component and the monitoring component, is used to prepare the target particle size sludge into a mixed liquid according to the wastewater indicators, and then return it to the wastewater treatment unit to form a vertical flow sludge treatment unit with sludge return self-supply.

[0014] Furthermore, the recycling components include: a storage unit, a sludge return branch, a wastewater inlet unit, a water supply branch, and a mixed liquor branch;

[0015] The storage unit is connected at the top to the sludge discharge device and at the bottom to the inlet of the sludge return branch; the outlet of the wastewater inlet unit is connected to the inlet of the water supply branch.

[0016] The outlet of the sludge return branch is connected to the outlet of the water supply branch. After merging into a mixed liquid, it is connected to the diversion device through the mixed liquid branch.

[0017] Furthermore, the monitoring components include an ammonia nitrogen concentration sensor, a nitrite nitrogen concentration sensor, and a granular sludge concentration sensor installed in the wastewater treatment unit, which are used to detect ammonia nitrogen concentration, nitrite nitrogen concentration, and granular sludge concentration, respectively.

[0018] The control component is used to control the sludge return process based on the concentrations of ammonia nitrogen, nitrite nitrogen, and granular sludge.

[0019] Furthermore, the sludge return process is controlled based on the concentrations of ammonia nitrogen, nitrite nitrogen, and granular sludge, specifically as follows:

[0020] The basic recirculation rate is determined based on the ratio of ammonia nitrogen concentration to nitrite nitrogen concentration, combined with the effective volume of the wastewater treatment unit.

[0021] Based on the granular sludge concentration, the baseline return velocity is corrected to obtain the final determined sludge return velocity.

[0022] Furthermore, the recirculation rate is adjusted in stages according to the deviation between the ammonia nitrogen / nitrite nitrogen ratio within the wastewater treatment unit and the set threshold: when the ammonia nitrogen / nitrite nitrogen ratio is 0.8~1.0, the recirculation rate is set to 5%~8% / h of the effective reactor volume; when the ammonia nitrogen / nitrite nitrogen ratio is 0.5~0.8, the recirculation rate is set to 8%~12% / h of the effective reactor volume; when the ammonia nitrogen / nitrite nitrogen ratio is less than 0.5, the recirculation rate is set to 12%~15% / h of the effective reactor volume.

[0023] Furthermore, based on the granular sludge concentration, the baseline return velocity is corrected to obtain the final determined sludge return velocity, specifically:

[0024] When the granular sludge concentration is below the set threshold, a positive correction coefficient is determined, and the basic return velocity is increased proportionally to obtain the final determined sludge return velocity; when the granular sludge concentration is above the set threshold, a negative correction coefficient is determined, and the basic return velocity is decreased proportionally to obtain the final determined sludge return velocity.

[0025] Furthermore, the monitoring components also include a sludge concentration sensor disposed within the storage unit for detecting the concentration of the stored sludge;

[0026] A control component is used to control the influent rate of the wastewater influent unit based on the sludge concentration.

[0027] Furthermore, the sludge discharge device is located below the flow guiding device and is used to screen granular sludge with a particle size smaller than the first set threshold to flow upward; granular sludge with a particle size larger than the second set threshold to sink downward; granular sludge with a target particle size between the first set threshold and the second set threshold is introduced into the return flow device; the first set threshold is smaller than the second set threshold.

[0028] On the other hand, the present invention also provides a wastewater treatment process, employing any of the above-mentioned self-supplying vertical flow wastewater processors, the steps of which include:

[0029] First, the wastewater to be treated is introduced into the wastewater treatment unit. The granular sludge gradually matures during the flow process and enters the sludge discharge device, where sludge that has reached the target particle size is automatically separated, and the granular sludge is orderly introduced into the return device.

[0030] Finally, the separated target granular sludge is returned to the flow guiding device via the reflux device, realizing the self-circulation enrichment and dynamic replenishment of granular sludge. Sludge that does not reach the target particle size continues to circulate and grow inside the reactor, forming a continuous dynamic screening and maturation closed loop. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art are briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort. In the drawings, the same parts use the same reference numerals. The drawings are not drawn to scale.

[0032] Figure 1 This is a schematic diagram of the structure of one embodiment of a self-supplying vertical flow sewage processor according to the present invention;

[0033] Figure 2 This is a front view schematic diagram of an embodiment of a sludge removal device for a self-supplying vertical flow sewage processor according to the present invention;

[0034] Figure 3 This is a top view schematic diagram of an embodiment of a sludge removal device for a self-supplying vertical flow sewage processor according to the present invention;

[0035] Figure 4 This is a partial structural schematic diagram of an embodiment of a self-supplying vertical flow sewage treatment recycling device according to the present invention. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0037] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on the other component or there may be an intervening component present. When a component is referred to as "connected to" another component, it can be directly connected to the other component or there may be an intervening component present.

[0038] It should also be noted that if the embodiments of the present invention involve directional indications, such as up, down, left, right, front, back, etc., these directional indications are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indications will also change accordingly. Furthermore, if the embodiments of the present invention involve descriptions such as "first," "second," "S1," "S2," "step one," "step two," etc., these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance, or implicitly indicating the number of technical features indicated or the order of method execution. Those skilled in the art will understand that anything that does not violate the inventive concept and does not contradict the inventive points should be included within the scope of protection of the present invention.

[0039] refer to Figure 1-4 As shown, the present invention provides a self-supplying vertical flow sewage processor, comprising: a sewage processor body, a sludge discharge device, and a return device;

[0040] The wastewater treatment unit is used to introduce wastewater and produce granular sludge;

[0041] The sludge discharge device 5 is located at the bottom of the reaction chamber of the wastewater treatment unit, preferably partially embedded in the bottom of the wastewater treatment unit, and is used to discharge sludge of the target particle size.

[0042] The return device 6 is connected to the sludge discharge device and the wastewater treatment unit, and is used to return sludge of the target particle size.

[0043] In this embodiment, a self-supplying vertical flow sewage processor of the present invention is presented. In view of the problems of existing sewage processors that require additional sludge replenishment and lack self-recycling of sludge cultivated in sewage, the core technical concept of the present invention is proposed: first, sludge of the target particle size is exported for later use through a sludge export device, and then the sludge of the target particle size is reintroduced into the sewage processor body through a return device according to the reaction process in the reaction chamber, so as to achieve self-supply without the need for additional replenishment.

[0044] Specifically: On the one hand, a sludge discharge device is added to the bottom of the reaction chamber of the traditional sewage treatment unit to discharge sludge of the target particle size (preferably granular sludge within a suitable particle size range containing the most functional bacteria and the strongest activity) for later use; on the other hand, a return device is added to determine whether activated sludge needs to be added based on the sewage index in the reaction chamber. When the required granular sludge in the self-supplying vertical flow sewage treatment unit is insufficient, the discharged sludge of the target particle size is prepared into a mixed liquid and returned to the sewage treatment unit to form a return self-supplying vertical flow sludge processor.

[0045] This scheme utilizes self-cultivated sludge to replenish the granular sludge in the reactor, promoting anaerobic ammonia oxidation. While enhancing biological denitrification, it also enables the self-filling and reuse of granular sludge in the reactor, achieving the recycling of microbial resources. This not only further promotes the formation of the granular sludge system, improves wastewater treatment efficiency, and reduces wastewater treatment costs, but also helps to enrich and maintain a suitable granular sludge particle size distribution within the system. This ensures that functional bacteria such as anaerobic ammonia oxidizing bacteria and ammonia oxidizing bacteria are stably enriched and activated in suitable sludge particles, enhancing the system's self-supply and efficient denitrification capabilities. By cultivating sludge of a specific target particle size inside the reactor, the sludge can be recycled back into the reactor at appropriate times, thereby enhancing the reactor's self-sufficiency. This allows functional microorganisms, such as anaerobic ammonia oxidizing bacteria (Anammox), nitrifying bacteria, and denitrifying bacteria, to be stably enriched and kept active within the sludge particles, achieving simultaneous removal of ammonia nitrogen and nitrite nitrogen as well as organic matter removal. This allows for continuous self-sufficiency of sludge and functional microorganisms without the need for external microorganisms or exogenous sludge.

[0046] Preferably, the reflux device 6 includes a recovery component 61, a monitoring component 62, and a control component 63;

[0047] The recycling component, connected to the sludge discharge device, is used to store and return sludge of the target particle size.

[0048] The monitoring component is installed inside the reaction chamber of the wastewater treatment unit and is used to monitor wastewater indicators.

[0049] The control component, connected to the recovery component and the monitoring component, is used to prepare the target particle size sludge into a mixed liquid according to the wastewater indicators, and then return it to the wastewater treatment unit to form a vertical flow sludge treatment unit with sludge return self-supply.

[0050] More preferably, the recycling components include: a storage unit 611, a sludge return branch 612, a wastewater inlet unit 613, a water supply branch 614, and a mixed liquor branch 615;

[0051] The storage unit is connected at the top to the sludge discharge device and at the bottom to the inlet of the sludge return branch; the outlet of the wastewater inlet unit is connected to the inlet of the water supply branch.

[0052] The outlet of the sludge return branch is connected to the outlet of the water supply branch. After merging into a mixed liquid, it is connected to the main body of the wastewater treatment plant through the mixed liquid branch. Preferably, it is returned to the flow guiding device of the wastewater treatment plant to directly participate in the internal circulation. More preferably, it is returned to the flow guiding device and located below the aeration device to replenish sludge at the location where large particles aggregate, thereby improving the anaerobic ammonia oxidation reaction in that area.

[0053] In this embodiment, the storage unit, connected to the sludge discharge device, receives and temporarily stores granular sludge of the target particle size, achieving sludge separation and accumulation. The sludge return branch, connecting the storage unit and the flow guiding device, is responsible for transporting the stored granular sludge back to the reactor, ensuring continuous sludge circulation. The wastewater inlet unit is connected to the sludge return branch via a water supply branch, providing water to the sludge return branch, adjusting the dilution level of the return liquid, and maintaining good suspension and fluidity of the granular sludge. After mixing, the sludge return branch and the water supply branch form a mixed liquid, which is then connected to the flow guiding device via the mixed liquid branch. Through this structure, granular sludge of the target particle size can be stably accumulated, effectively transported, and appropriately diluted, promoting the recycling of sludge within the reactor and facilitating the stable growth of functional microorganisms and efficient wastewater treatment.

[0054] Preferred, such as Figure 4 As shown, the bottom of the storage unit 611 tapers into a cone shape and then tapers to the point where it connects with the sludge return branch 612.

[0055] In this embodiment, the bottom of the storage unit is designed as a tapered structure that gradually narrows to connect with the sludge return branch. This design facilitates the natural concentration of granular sludge at the bottom connection point under gravity, reducing sludge retention and dead zones, and preventing sludge from accumulating and clumping inside the tank. Simultaneously, this structure allows sludge to flow more smoothly into the return branch, achieving continuous and stable sludge transport and return, ensuring the efficient recycling of granular sludge. Furthermore, the tapered, tapered structure helps increase the flow rate during sludge discharge, reducing energy consumption and the risk of return blockage, further optimizing the sludge return path, and ensuring the efficient and stable operation of the system.

[0056] Preferably, the monitoring component 62 includes an ammonia nitrogen concentration sensor, a nitrite nitrogen concentration sensor, and a granular sludge concentration sensor disposed within the wastewater treatment unit body. Preferably, these sensors are disposed within the outer reaction chamber of the wastewater treatment unit body and are used to detect the ammonia nitrogen concentration, nitrite nitrogen concentration, and granular sludge concentration, respectively.

[0057] The control component 63 may optionally include a first control element 631 disposed on the sludge return branch, for controlling the sludge return process based on the ammonia nitrogen concentration, nitrite nitrogen concentration and granular sludge concentration.

[0058] This embodiment provides a preferred configuration of the monitoring and control components, enabling real-time monitoring of key wastewater indicators in the reaction chamber to replenish target-size sludge in a timely and appropriate manner. Specifically, the monitoring component accurately detects the concentrations of ammonia nitrogen and nitrite nitrogen, allowing the control component to determine whether and how much sludge needs to be added to the reaction chamber based on their concentration ratio. Furthermore, a first control element located on the sludge return branch dynamically adjusts the return rate of the target-size granular sludge, achieving effective recycling of the granular sludge within the system. This dynamic regulation of the return process effectively avoids efficiency reduction caused by insufficient or excessive return, ensuring the stability and efficiency of the wastewater treatment process.

[0059] Preferably, the sludge return process is controlled based on the concentrations of ammonia nitrogen, nitrite nitrogen, and granular sludge, specifically as follows:

[0060] The basic recirculation rate is determined based on the ratio of ammonia nitrogen concentration to nitrite nitrogen concentration, combined with the effective volume of the wastewater treatment unit.

[0061] Based on the granular sludge concentration, the baseline return velocity is corrected to obtain the final determined sludge return velocity.

[0062] In this embodiment, a preferred embodiment for controlling the sludge return process is provided. Optionally, the overall index within the wastewater treatment unit can be controlled by adjusting the return rate of the target particle size granular sludge to achieve an ammonia nitrogen / nitrite nitrogen ratio of 1~1.3, preferably 1.2. When the ammonia nitrogen ratio in the reactor is less than 1, the return device is activated to introduce sludge, achieving self-replenishment of the granular sludge. When the ammonia nitrogen ratio in the reactor is greater than 1.3, the return device is shut off, stopping the sludge introduction. Specifically:

[0063] First, the basic recirculation rate is determined based on the ratio of ammonia nitrogen concentration to nitrite nitrogen concentration, combined with the effective volume of the wastewater treatment unit. Preferably, the basic recirculation rate is adjusted in stages according to the deviation of the ammonia nitrogen / nitrite nitrogen ratio within the wastewater treatment unit from a set threshold: when the ammonia nitrogen / nitrite nitrogen ratio is 0.8~1.0, the recirculation rate is set to 5%~8% / h of the effective reactor volume; when the ammonia nitrogen / nitrite nitrogen ratio is 0.5~0.8, the recirculation rate is set to 8%~12% / h of the effective reactor volume; when the ammonia nitrogen / nitrite nitrogen ratio is less than 0.5, the recirculation rate is set to 12%~15% / h of the effective reactor volume.

[0064] Then, based on the granular sludge concentration, the baseline return velocity is corrected to obtain the final determined sludge return velocity. Preferably, when the granular sludge concentration is below a set threshold, a positive correction coefficient is determined, and the baseline return velocity is increased proportionally to obtain the final determined sludge return velocity. When the granular sludge concentration is above the set threshold, a negative correction coefficient is determined, and the baseline return velocity is decreased proportionally to obtain the final determined sludge return velocity. For example: when MLSS is too low and the total amount of granular sludge is insufficient, the return velocity needs to be increased to accelerate replenishment. For example: when MLSS < 6 g / L, the baseline return velocity (preferably a staged return velocity) is increased by 20% to 30%. When MLSS is too high and the granular sludge load is too high, the return velocity needs to be reduced to avoid blockage. For example: when MLSS ≥ 12 g / L, the baseline return velocity (preferably a staged return velocity) is reduced by 10% to 20%.

[0065] More preferably, refer to Figure 1 and Figure 4 The monitoring component 62 also includes a sludge concentration sensor disposed within the storage unit for detecting the concentration of the stored sludge;

[0066] The control component 63 also includes a second control element 632 disposed in the water supply branch 614 for controlling the inflow rate of the wastewater inlet unit according to the sludge concentration.

[0067] In this embodiment, a preferred embodiment of the monitoring and control components is provided to realize real-time monitoring of key indicators of sludge in the storage tank. When sludge is returned, the water distribution is adjusted according to the sludge concentration, so that the final mixed liquid is a suitable mixture adapted to the current sludge condition and the reaction process in the reaction chamber, thereby improving the adaptability and accuracy of sludge return.

[0068] The above describes a preferred embodiment of the reflux device. A first control component is installed on the sludge reflux branch, and a second control component is installed on the water supply branch. Both components include a actuator and a switching valve, enabling precise regulation of the sludge reflux flow rate and water supply volume. The first control component regulates the reflux flow rate and velocity of granular sludge in the sludge reflux branch, while the second control component regulates the water supply flow rate in the water supply branch, thus coordinating the control of the reflux liquid concentration and ensuring a stable flow supply. By controlling the opening and closing angle of the switching valve through the actuator, the ratio of the two fluids can be flexibly adjusted according to operational needs, ensuring thorough mixing and appropriate dilution of sludge and water during the reflux process. This promotes efficient reflux and recycling of granular sludge within the system, improving overall treatment efficiency and stability.

[0069] In summary, this invention presents a self-supplied vertical flow wastewater treatment system that enables self-sufficient sludge reuse and full utilization of excess sludge. It is worth noting that the specific structure of the wastewater treatment system body and the sludge discharge device is not limited here. The key point of this invention is that, based on traditional wastewater treatment systems, it can discharge sludge of the target particle size for later use, and, guided by reaction progress indicators within the reaction chamber, reformat the sludge of the target particle size and return it to the reaction chamber, thus achieving sludge self-filling and reuse, which falls within the scope of the technical concept of this invention.

[0070] Preferred:

[0071] (I) Reference Figure 1 The wastewater treatment unit may include: an outer cylinder 1, an inner cylinder 2, a flow guiding device 3, and an aeration device 4.

[0072] The inner cylinder and the outer cylinder are coaxially nested to form an inner reaction chamber 21 located inside the inner cylinder and an outer reaction chamber 22 located between the inner cylinder and the outer cylinder.

[0073] The flow guiding device is located at the axial bottom of the inner cylinder and includes: a flow guiding component 31, a screen hole 32 disposed on the side wall of the flow guiding component, and a through hole 33 inside the flow guiding component; the aperture of the screen hole is smaller than the aperture of the through hole; more preferably, the aperture of the screen hole is 1.5 mm, used to restrict large-diameter sludge particles from entering the inner reaction chamber; the aperture of the through hole is 6 mm, used to discharge large-diameter particles or sediments. This design can effectively perform primary screening of sludge and enhance flow stability.

[0074] An aeration device is installed inside the through hole, providing upward aeration; this aeration device can provide a locally oxygen-rich environment to the inner reaction chamber. More preferably, the aeration device is located in the middle of the through hole, below the flow propulsion device 7, and consists of an annular air distribution pipe and a centrally located aeration head, with an aeration volume of 0.3–0.5 m³ / s. 3 During operation, the dissolved oxygen (DO) in the internal reaction chamber is maintained at 0.6–0.8 mg / L, which is beneficial for the enrichment and activity maintenance of ammonia-oxidizing bacteria (AOB).

[0075] This embodiment presents a preferred embodiment of the wastewater treatment unit, using conventional wastewater as the influent source. During operation, the reactor, through a separation design of inner and outer cylinders, forms two functionally complementary biochemical reaction zones: an aerobic zone corresponding to the inner reaction chamber and an anaerobic zone corresponding to the lower end of the outer reaction chamber. The inner reaction chamber (aerobic zone), located inside the inner cylinder, has an aeration device that introduces a suitable amount of oxygen from the bottom, creating a locally oxygen-rich environment. Notably, under the action of the aeration device, this area can maintain a suitable dissolved oxygen environment. This area is enriched with ammonia-oxidizing bacteria (AOB), which oxidize the ammonia nitrogen portion of large-diameter granular sludge in the wastewater into nitrite. By precisely controlling the dissolved oxygen concentration, further oxidation of nitrite to nitrate is inhibited, ensuring that the nitrification reaction remains at an intermediate stage, providing the necessary substrate for subsequent anaerobic ammonia oxidation. The lower end of the outer reaction chamber (anaerobic zone): Located between the inner and outer cylinders, the lower outer reaction chamber has an extremely low oxygen concentration, even approaching zero. This area is enriched with anaerobic ammonia-oxidizing bacteria (AnAOB), which utilize the nitrite produced in the internal reaction chamber to directly react with the remaining ammonia nitrogen to generate nitrogen gas, achieving efficient denitrification; thus, more and more sludge of the target particle size is formed at the bottom of the reaction chamber of the wastewater treatment unit.

[0076] (ii) As the second inventive point of this invention, a sludge discharge device 5 is proposed, which is set at the bottom of the reaction chamber of the sewage treatment body, preferably below the flow guiding device, for screening granular sludge with a particle size smaller than a first set threshold to flow upward; granular sludge with a particle size larger than a second set threshold to sink (this part of the sludge will flow out through the sludge discharge port 9 set at the bottom of the outer cylinder); granular sludge with a target particle size between the first set threshold and the second set threshold is introduced into the return flow device; the first set threshold is smaller than the second set threshold.

[0077] In this embodiment, the sludge discharge device is further defined by functional objectives. The purpose is to further obtain a sludge inlet and return device with a target particle size. The core of this device is: 1. It is used to screen granular sludge with a particle size smaller than a first set threshold. Specifically, small-particle sludge, driven by the upward flow, flows directly upwards after screening and quickly participates in the internal circulation. Specifically, the upward-flowing granular sludge, because its particle size is smaller than the first set threshold, indicates that it has not fully reacted and has not yet grown into mature, matured sludge. It can directly flow upwards to continue participating in the internal circulation until it grows into larger-particle sludge. 2. Granular sludge with a particle size larger than a second set threshold is blocked and flows out through the sludge discharge port. Specifically, the outflowing granular sludge, because its particle size is larger than the second set threshold, indicates that it has fully reacted and no longer contains useful substances. It can be directly discharged. 3. Target particle size sludge with a particle size between the first and second set thresholds is introduced into the return device; The introduced sludge, because its particle size is between the first and second set thresholds, indicates that it is surrounded by inorganic matter and the useful substances inside are not directly exposed. If it is directly fed into the internal circulation, it cannot be directly reused; if it is directly discarded, it will cause great waste, because it still contains a large number of highly active functional bacteria, which is the target particle size sludge required. It cannot be used directly, but it can be prepared and reused. The target particle size sludge can be first exported to the recycling device for storage through the sludge export device. When sludge needs to be added into the reactor body due to index requirements, it can be prepared into a mixed liquid and returned to the reaction chamber to improve its activity in participating in the internal circulation again and improve the recycling effect.

[0078] Preferably, the sludge discharge device 5 adopts a cyclone + screen guiding method, which is a cyclone screen guiding device, as shown in the reference. Figure 1 , Figure 2 and Figure 3 It includes a frame 51, a rotating assembly 52, a screen assembly 53, and a guide assembly 54;

[0079] The frame is closed on the sides and has a through hole 55 in the center; during use, the through hole is connected to the bottom of the sewage treatment unit, preferably to the bottom of the flow guiding component;

[0080] A rotating component is rotatably mounted inside the through hole;

[0081] The screen assembly is set inside the through hole, and its outer edge is connected to the inner wall of the shell frame;

[0082] The guide assembly is located on one side of the shell and communicates with the through hole.

[0083] In this embodiment, the structure and operation of the sludge discharge device are as follows: the sludge mixture enters the device from the bottom of the through hole. Different types of granular sludge are subjected to the combined effects of gravity, fluid shear force generated by the rotation of the rotating component, and swirling induction force, and are diverted to three different directions. Specifically: due to differences in particle composition, sludge containing more inorganic components (such as hydroxyapatite) has relatively large particle size and density, and is prone to gravity settling at the bottom of the device, and is directly discharged from the sludge discharge port; while granular sludge containing more functional microorganisms has a lower density, rises with the main liquid flow and enters the screening section—the sludge discharge device. On the one hand, granular sludge with a particle size smaller than the first set threshold (small particle size, low density, light weight, and moving upward with the rising flow) directly passes through the screen component and participates in the internal circulation; on the other hand, granular sludge with a medium particle size is blocked. At this time, the rotating component rotates at high speed, forming a stable swirling flow inside the through hole. The particles in the swirling flow field are subjected to centrifugal forces of different intensities due to differences in particle size and density. Granular sludge of the target particle size is thrown against the side wall of the device under centrifugal force and smoothly introduced into the connected guide assembly, thereby achieving efficient separation and directional collection of particles. This device integrates gravity sedimentation, screen classification, and cyclone centrifugation, which can accurately screen out granular sludge of suitable particle size and rich in functional microorganisms, taking into account both sludge structural stability and microbial activity, effectively improving system operating efficiency and sludge resource utilization level, and significantly reducing subsequent treatment load and overall operating costs.

[0084] For details, please refer to Figure 2 and Figure 3 The rotating assembly includes a rotating spindle, rotating blades mounted on the rotating spindle, and an external rotating drive for forming a stable outward vortex inside the through hole.

[0085] In this embodiment, the rotary drive generates rotational power and outputs it to the rotary spindle, which further drives the rotary blades mounted thereon. This causes the rising liquid flow to swirl under the drive of the rotary blades. Different particle sizes of sludge are subjected to different centrifugal forces under the action of the swirling flow, and thus occupy different positions within different through-holes, achieving further screening of the different granular sludge particles. Specifically, larger particle sizes and higher densities of granular sludge are located in the outer layer of the through-holes, while larger particle sizes and lower densities of granular sludge are located in the inner layer of the through-holes.

[0086] Optionally, the rotary drive component is a waterproof motor to meet the requirements of wet conditions; more preferably, the rotary drive component is a waterproof servo motor to meet various speed change requirements and realize the function of quickly adjusting the flow rate of the vortex.

[0087] Preferred, Reference Figure 2The screen assembly 53 includes a first screen 53a disposed above the through hole 55 and a second screen 53b disposed below the through hole 55. The mesh size of the first screen 53a is smaller than that of the second screen 53b. The mesh size of the first screen corresponds to a first set threshold, used to screen granular sludge with a particle size smaller than the first set threshold through the screening upstream. The mesh size of the second screen corresponds to a second set threshold, used to screen granular sludge with a particle size larger than the second set threshold through the discharge port. Granular sludge with a target particle size between the first and second set thresholds is retained and introduced into a reflux device for recycling, achieving efficient sorting and targeted utilization of granular sludge of different particle sizes, thereby screening out matured granular sludge with a suitable particle size range for better screening results. For example, the first screen has a mesh size of 5 mm and the second screen has a mesh size of 3 mm, which initially separates the target sludge particles with a diameter of 3 to 5 mm, thereby improving the screening efficiency of the subsequent rotating components.

[0088] Preferred, Reference Figure 1 and Figure 2 The guide assembly 54 includes at least one guide tube 541;

[0089] The guide pipe is arranged at an upward angle relative to the horizontal plane, with the first end connected to the through hole and the second end connected to the outside.

[0090] The diameter of the drainage pipe gradually decreases from the inlet to the outlet along the direction of sewage flow, forming a tapering structure.

[0091] In this embodiment, the structure of the drainage component is further defined, deviating from conventional technical choices: the drainage pipe is arranged at an angle, so that when the granular sludge rises along the pipe wall, the denser particles are more significantly affected by gravity, making it difficult for them to continue flowing upwards. They then naturally fall back into the through-hole, achieving effective separation of high-density inorganic granular sludge, avoiding the misdischarge of denser inorganic particles, and improving the recovery efficiency of functional microorganisms. This ensures that the screened granular sludge of the target particle size is quickly and efficiently guided to the external environment, achieving smooth discharge or transport, reducing internal accumulation and retention; it also discharges air bubbles inherent in the wastewater flow or those generated by the rotation of the rotating component, preventing excessive pressure within the device and improving operational stability. Simultaneously, because the inlet of the drainage pipe gradually narrows towards the outlet, the flow velocity within the pipe gradually increases, creating a certain negative pressure effect at the outlet, rapidly discharging the less dense granular sludge containing more functional microorganisms. By cleverly utilizing the combined effects of gravity, gradual increase in flow velocity, and negative pressure, it is possible to both block the reflux of high-density inorganic particles and efficiently extract low-density, well-matured sludge particles rich in functional microorganisms, achieving reflux and discharge of different particle sizes and further improving the selectivity and precision of the target particle size.

[0092] More preferably, refer to Figure 2 and Figure 3 The 541 conduit includes several pipes;

[0093] They are circumferentially spaced at the same height on the shell and tangentially distributed along the direction of the swirling flow of wastewater on the shell.

[0094] The inlets of each guide pipe are located at the same horizontal height inside the shell.

[0095] In this embodiment, a further preferred embodiment of the discharge pipes is provided: 1. Multiple discharge pipes can improve discharge efficiency; 2. Each discharge pipe is circumferentially spaced at the same height of the shell and tangentially distributed along the swirling direction of the wastewater in the shell; the inlet of each discharge pipe is located at the same horizontal height inside the shell, so that the granular sludge of the target particle size being screened naturally enters the discharge pipe along the swirling direction, reducing abrupt changes in flow direction, reducing turbulence, resistance, and reverse flow, thereby further improving screening efficiency. For example, see reference. Figure 3 There are 3 guide pipes, which are set at 120° intervals along the side wall of the shell.

[0096] In summary, a preferred sludge removal device of the present invention is provided, which uses gravity + screening + cyclone triple force field to screen out sludge of the target particle size, and then, through a reflux device, refluxes it back into the reaction chamber at an appropriate time to achieve self-replenishment of granular sludge.

[0097] It is worth noting that the specific structure of the sludge discharge device is only a preferred example and is not intended to limit the invention. The first inventive point of this invention provides the overall technical concept of this application. Under this concept, a simple filtration method that does not involve swirling but directly sets up a filter screen is also an option for screening out sludge of the target particle size. (three),

[0099] On the other hand, the present invention also provides a wastewater treatment process, employing any of the above-mentioned self-supplying vertical flow wastewater processors, the steps of which include:

[0100] First, the wastewater to be treated is introduced by the diversion device. The liquid flows through the screen holes to screen flocculent sludge and small-diameter granular sludge, which circulate and grow in the first circulation path between the inner reaction chamber and the screen holes. Meanwhile, large-diameter granular sludge flows along the second circulation path of the inner reaction chamber, outer reaction chamber and through holes, forming a vertical flow from bottom to top, realizing the primary stratification of particles of different sizes.

[0101] Next, the aeration device creates a locally oxygen-rich environment in the inner reaction chamber, enriching ammonia-oxidizing bacteria to oxidize ammonia nitrogen in the wastewater into nitrite. The lower end of the outer reaction chamber maintains a low-oxygen environment to enrich anaerobic ammonia-oxidizing bacteria, which use the generated nitrite to react with the remaining ammonia nitrogen to generate nitrogen gas, thus achieving simultaneous denitrification.

[0102] Next, the granular sludge matures gradually during the flow process and enters the sludge discharge device. Through gravity settling, screen classification and rotary separation, the sludge that has reached the target particle size is automatically separated, and the granular sludge is orderly introduced into the return device.

[0103] Finally, the separated target granular sludge is returned to the flow guiding device via the reflux device, realizing the self-circulation enrichment and dynamic replenishment of granular sludge. Sludge that does not reach the target particle size continues to circulate and grow inside the reactor, forming a continuous dynamic screening and maturation closed loop.

[0104] This embodiment presents a wastewater treatment process that utilizes a dual-circulation path (first circulation path and second circulation path) to achieve primary stratification of flocculent sludge, small-diameter sludge, and large-diameter sludge under vertical flow and sieve screening. This facilitates the separation and maturation of sludge of different particle sizes, improving granulation efficiency. By leveraging the locally enriched oxygen environment of the internal reaction chamber and the hypoxic environment of the external reaction chamber, ammonia-oxidizing bacteria and anaerobic ammonia-oxidizing bacteria are enriched, achieving efficient conversion of ammonia nitrogen to nitrogen gas, avoiding the accumulation of nitrite and ammonia nitrogen, and improving denitrification efficiency. A sludge discharge device enables gravity settling, sieving, and cyclone grading of sludge. Granular sludge reaching the target particle size can be automatically discharged or recycled, ensuring the orderly enrichment and dynamic replenishment of granular sludge, thereby increasing the system's granular sludge concentration and treatment capacity. Sludge that does not reach the target particle size continues to circulate and mature inside the reactor, forming a continuous dynamic screening and maturation closed loop. This eliminates the need for frequent sludge discharge and replenishment, reducing operation and maintenance costs. At the same time, it ensures the stability of the granular sludge structure within the system, extends the sludge age, and improves the system's resistance to shock loads.

[0105] The above-described wastewater treatment process is based on the self-supplying vertical flow wastewater processor, and its technical effects and features are combined in detail here. The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the protection scope of the present invention.

Claims

1. A self-supplying vertical flow sewage treatment unit, characterized in that, It includes a wastewater treatment unit, a sludge removal device, and a return device; the wastewater treatment unit is used to introduce wastewater and produce granular sludge. The sludge removal device is partially embedded in the bottom of the wastewater treatment unit and is used to remove sludge particles of the target particle size. The return device is connected to the sludge discharge device and the wastewater treatment unit, and is used to return sludge of the target particle size. This includes recycling components, monitoring components, and control components; The recycling component, connected to the sludge discharge device, is used to store and return sludge of the target particle size. The monitoring component, located within the reaction chamber of the wastewater treatment unit, monitors wastewater parameters. The control component, connected to the recovery and monitoring components, prepares a mixed solution of target-size granular sludge according to the wastewater parameters and then returns it to the wastewater treatment unit, forming a self-supplied vertical flow sludge processor. The monitoring component includes an ammonia nitrogen concentration sensor, a nitrite nitrogen concentration sensor, and a granular sludge concentration sensor, all located within the wastewater treatment unit, to detect ammonia nitrogen concentration, nitrite nitrogen concentration, and granular sludge concentration, respectively. The control component determines the basic return velocity based on the ratio of ammonia nitrogen concentration to nitrite nitrogen concentration, combined with the effective volume of the wastewater treatment unit; and corrects the basic return velocity based on the granular sludge concentration to obtain the final determined sludge return velocity. The basic reflux rate is adjusted in stages according to the deviation between the ammonia nitrogen / nitrite nitrogen ratio in the wastewater treatment unit and the set threshold: when the ammonia nitrogen / nitrite nitrogen ratio is 0.8~1.0, the reflux rate is set to 5%~8% / h of the effective reactor volume; when the ammonia nitrogen / nitrite nitrogen ratio is 0.5~0.8, the reflux rate is set to 8%~12% / h of the effective reactor volume; when the ammonia nitrogen / nitrite nitrogen ratio is less than 0.5, the reflux rate is set to 12%~15% / h of the effective reactor volume.

2. The vertical flow sewage processor according to claim 1, characterized in that, The recycling components include: a storage unit, a sludge return branch, a wastewater inlet unit, a water supply branch, and a mixed liquor branch; The storage unit is connected at the top to the sludge discharge device and at the bottom to the inlet of the sludge return branch; the outlet of the wastewater inlet unit is connected to the inlet of the water supply branch. The outlet of the sludge return branch is connected to the outlet of the water supply branch. After merging into a mixed liquid, it is connected to the diversion device through the mixed liquid branch.

3. The vertical flow sewage processor according to claim 1, characterized in that, Based on the granular sludge concentration, the baseline return velocity is corrected to obtain the final determined sludge return velocity, specifically: When the granular sludge concentration is below the set threshold, a positive correction coefficient is determined, and the basic return velocity is increased proportionally to obtain the final determined sludge return velocity; when the granular sludge concentration is above the set threshold, a negative correction coefficient is determined, and the basic return velocity is decreased proportionally to obtain the final determined sludge return velocity.

4. The vertical flow sewage processor according to claim 3, characterized in that, The monitoring components also include a sludge concentration sensor located within the storage unit for detecting the concentration of stored sludge; A control component is used to control the influent rate of the wastewater influent unit based on the sludge concentration.

5. The vertical flow sewage processor according to any one of claims 1 to 4, characterized in that, The sludge discharge device is located below the flow guiding device and is used to screen granular sludge with a particle size smaller than a first set threshold to flow upward; granular sludge with a particle size larger than a second set threshold to sink downward; granular sludge with a target particle size between the first set threshold and the second set threshold is introduced into the return flow device; the first set threshold is less than the second set threshold.

6. The vertical flow sewage processor according to claim 5, characterized in that, The sludge discharge device includes a frame, a rotating assembly, a screen assembly, and a discharge guide assembly; The frame is closed on the sides and has a through hole in the center; the through hole is connected to the bottom of the wastewater treatment unit. A rotating component is rotatably mounted inside the through hole; The screen assembly is set inside the through hole, and its outer edge is connected to the inner wall of the shell frame; The guide assembly is located on one side of the shell and communicates with the through hole.

7. The vertical flow sewage processor according to claim 6, characterized in that, The rotating assembly includes a rotating spindle, rotating blades mounted on the rotating spindle, and an external rotating drive for forming a stable outward vortex inside the through hole.

8. The vertical flow sewage processor according to claim 7, characterized in that, A screen assembly includes: a first screen disposed above a through hole, and a second screen disposed below the through hole; the mesh size of the first screen is smaller than that of the second screen. The first screen has a mesh size corresponding to a first set threshold, used to screen granular sludge with a particle size smaller than the first set threshold through the screen upward; the second screen has a mesh size corresponding to a second set threshold, used to screen granular sludge with a particle size larger than the second set threshold through the sludge discharge port.

9. The vertical flow sewage processor according to claim 8, characterized in that, The drainage assembly includes at least one drainage pipe; the drainage pipe is arranged at an upward angle relative to the horizontal plane, with its first end connected to the through hole and its second end connected to the outside; the diameter of the drainage pipe gradually decreases from the inlet to the outlet along the direction of sewage flow, forming a tapered structure.

10. A wastewater treatment process, employing the self-supplying vertical flow wastewater processor as described in any one of claims 1 to 9, characterized in that the step include: First, the wastewater to be treated is introduced into the wastewater treatment unit. The granular sludge gradually matures during the flow process and enters the sludge discharge device, where sludge that has reached the target particle size is automatically separated, and the granular sludge is orderly introduced into the return device. Finally, the separated target granular sludge is returned to the flow guiding device via the reflux device, realizing the self-circulation enrichment and dynamic replenishment of granular sludge. Sludge that does not reach the target particle size continues to circulate and grow inside the reactor, forming a continuous dynamic screening and maturation closed loop.

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