Integrated equipment for sewage autotrophic denitrification and sewage treatment process

Abstract

The present application relates to a kind of sewage autotrophic denitrification integrated equipment and sewage treatment process, comprising: water inlet unit, anaerobic unit, oxygen limiting unit, autotrophic denitrification simultaneous phosphorus removal unit and water outlet unit connected in sequence, each unit is integrally connected in series along the sewage treatment flow direction, and is sequentially linked to form closed processing flow channel by communication structure;It is with PN / A process as core, scientific structure, efficient operation, modular integration, integrated sewage treatment system with carbon-nitrogen-phosphorus collaborative removal function, meet the current water environment management " high standard, low carbonization, intelligentization " development needs, with stable and reliable, economic and efficient, easy to operate, highly integrated advantages, can simultaneously low-carbon removal nitrogen and phosphorus pollutants, can be widely applied to municipal sewage and industrial wastewater treatment.

Description

Technical Field

[0001] This invention belongs to the technical field of wastewater treatment equipment, and particularly relates to an integrated equipment for autotrophic denitrification of wastewater and a wastewater treatment process. Background Technology

[0002] With the increasing severity of eutrophication and water pollution, the efficient removal of nutrients such as nitrogen and phosphorus has become an important research and application area in wastewater treatment. Especially in the context of green development, there is an urgent need to develop new wastewater treatment devices that are green, low-carbon, system-integrated, and cost-effective.

[0003] Traditional biological nitrogen and phosphorus removal processes, such as A / A / O and A² / O, while offering stable treatment results, suffer from drawbacks including complex processes, high energy consumption, large footprint, and strong dependence on carbon sources. These limitations make them unsuitable for meeting the current demands for low-carbon and integrated wastewater treatment systems. In particular, the high construction and operating costs of traditional processes in small- to medium-scale or decentralized wastewater treatment scenarios hinder their widespread adoption.

[0004] In recent years, partial nitrification-anammox (PNA) technology has attracted widespread attention in the wastewater treatment field as a novel and highly efficient nitrogen removal process. This technology utilizes autotrophic anammox bacteria to reduce ammonia nitrogen (PNA) through partial nitrification and anammox processes. ) is directly converted into nitrogen gas ( PN / A reactors do not require additional carbon sources, significantly reducing energy consumption and sludge production. However, existing PN / A reactors are mostly at the laboratory or pilot engineering level, with complex system structures, high control requirements, and poor stability, making large-scale application difficult. Furthermore, these devices often focus solely on nitrogen removal, lacking sufficient capacity for the synergistic removal of other pollutants such as carbon and phosphorus, resulting in inconsistent overall effluent quality. In addition, some devices lack modular and intelligent design, leading to long commissioning cycles, complex operation and management, and low automation levels, limiting their application in rural wastewater, decentralized municipal wastewater, and industrial park scenarios. Moreover, the design concept of green and low-carbon-oriented devices is still incomplete; currently, there are few integrated wastewater treatment devices that simultaneously achieve high-efficiency nitrogen and phosphorus removal, low energy consumption, low carbon emissions, equipment integration, and ease of operation and maintenance. Therefore, there is an urgent need to develop an integrated wastewater treatment system with PN / A technology at its core, a scientifically constructed, highly efficient, modularly integrated system, and capable of synergistic removal of carbon, nitrogen, and phosphorus, to meet the current development needs of "high standards, low carbon, and intelligent" water environment governance.

[0005] Therefore, how to provide an integrated equipment and wastewater treatment process that is stable, reliable, economical, efficient, easy to operate, highly integrated, and capable of simultaneously removing nitrogen and phosphorus pollutants 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 an integrated autotrophic denitrification equipment for wastewater, characterized in that it comprises: an influent unit, an anaerobic unit, an oxygen-limiting unit, an autotrophic denitrification and simultaneous phosphorus removal unit, and an effluent unit connected in sequence, wherein each unit is arranged in series along the wastewater treatment flow direction and is connected in sequence through a connecting structure to form a closed treatment flow channel; The inlet unit is used for pretreatment sedimentation and filtration of wastewater, providing wastewater with impurities removed for subsequent units; The anaerobic unit, located adjacent to the influent unit, is used to provide an anaerobic environment to separate large molecular organic pollutants in wastewater, thus preventing large molecular organic matter from interfering with subsequent nitrogen and phosphorus removal reactions. The oxygen-limiting unit, located adjacent to the anaerobic unit, removes some organic pollutants and phosphorus from the wastewater by limiting aeration, creating a suitable water quality environment for the autotrophic nitrogen and phosphorus removal unit. The self-nutritive denitrification and simultaneous phosphorus removal unit is located adjacent to the oxygen-limiting unit and is used for the deep removal of nitrogen and phosphorus from wastewater. The effluent unit is located next to the autotrophic denitrification and simultaneous phosphorus removal unit. It is used to re-sediment the deeply treated wastewater and separate residual impurities to ensure the quality of the effluent.

[0007] Furthermore, the water inlet unit includes a housing, a bar screen assembly, a sedimentation tank, and an inlet separator; The shell has an inlet at the top; a bar screen assembly is located below the inlet to intercept impurities in the incoming water; a sedimentation tank is connected to the downstream of the bar screen assembly, and the bottom of the sedimentation tank is set as a triangular sedimentation zone; and an inlet separator is located at the bottom of the triangular sedimentation zone to discharge sludge or particulate matter deposited in the triangular sedimentation zone.

[0008] Furthermore, the shell of the inlet unit is elongated with a length-to-diameter ratio of 5-10:1; the shell length is 1.5-3m and the cross-sectional width is 0.2-0.5m. The elongated structure extends the residence time of the water flow in the sedimentation tank to 15-30 minutes. The sedimentation tank is inclined along the length of the shell, and the inclination angle matches the wall angle of the triangular sedimentation zone. The angle between the inclined wall of the triangular sedimentation zone and the horizontal plane is 50°-70°. The bar screen assembly is a detachable fine bar screen with a screen width of 0.5-2mm. An electric valve is installed at the inlet separation port, and the electric valve is electrically connected to the mud level sensor in the triangular sedimentation zone. A guide plate is also installed in the sedimentation tank, which is inclined along the inlet flow direction to guide the water flow evenly through the triangular sedimentation zone.

[0009] Furthermore, the anaerobic unit includes: an anaerobic chamber; An anaerobic inlet is provided on one side of the top of the anaerobic chamber, which is connected to the outlet of the sedimentation tank of the inlet unit; The anaerobic chamber is equipped with an anaerobic biological packing reaction zone in the middle. The bottom of the anaerobic chamber is equipped with an anaerobic sludge discharge port, and the bottom of the anaerobic chamber where the anaerobic sludge discharge port is located has a planar structure. An anaerobic outlet is located on the side wall of the anaerobic chamber below the anaerobic biological packing reaction zone and above the plane where the anaerobic sludge discharge port is located, and it is connected to the oxygen-limiting unit.

[0010] Furthermore, the anaerobic biological packing reaction zone includes a support structure and biological packing material; The supports are arranged at intervals and vertically installed within the anaerobic biological packing reaction zone; Biological packing material is arranged around the support structure; Active microorganisms are attached to the biological packing material.

[0011] Furthermore, the oxygen-limiting unit includes: an oxygen-limiting chamber, an oxygen-limiting aeration port, and an oxygen-limiting sludge discharge port; An oxygen-limiting inlet is located at the bottom of the oxygen-limiting chamber, which is connected to the anaerobic outlet of the anaerobic unit; an oxygen-limiting outlet is located at the top, which is connected to the autotrophic denitrification and phosphorus removal unit; so as to achieve water inlet at the bottom and water outlet at the top. The bottom of the oxygen-limiting chamber is equipped with an oxygen-limiting aeration port and an oxygen-limiting sludge discharge port; a vertical guide strip is installed near the right side wall of the oxygen-limiting chamber; this is used to guide the sewage to rise evenly and make full contact with the aeration airflow, avoiding dead zones and improving treatment efficiency.

[0012] Furthermore, the autotrophic denitrification and simultaneous phosphorus removal unit includes: an outer cylinder, an inner cylinder, a flow guiding component, a denitrification agent dosing component, and an aeration component; The inner cylinder is connected to the outer cylinder and is divided into an inner reaction chamber located inside the inner cylinder and an outer reaction chamber located between the inner cylinder and the outer cylinder. The flow guiding assembly, connected to the axial bottom end of the inner cylinder, includes: an inner inclined flow guiding part, an outer inclined flow guiding part, a sieve hole provided on the side wall of the inner inclined flow guiding part, and a through hole penetrating the flow guiding assembly; The denitrification agent dosing assembly is located outside the outer inclined guide section and is used for targeted dosing of enhanced denitrification agents; The aeration component is installed inside the outer inclined guide section and aerates upwards.

[0013] Furthermore, the denitrification agent dosing assembly includes: a sensor, a control unit, and a dosing unit; A sensor is used to monitor reaction indicators within the device; a control unit, connected at one end to the sensor and at the other end to the dosing unit, is used to issue a dosing signal based on the reaction indicators; the dosing unit, located outside the inclined guide section, is used to precisely add denitrifying agent to the outside of the inclined guide section based on the dosing signal. Preferably, the control unit is used to control the dosing valve and dosing drive on the dosing unit.

[0014] Furthermore, the dosing unit includes: an inlet pipe, and a dosing valve, a dosing drive, and a dosing water tank sequentially arranged on the inlet pipe; Dosing actuator, used to drive the opening or closing of the dosing valve; One end of the feed pipe is connected to the dosing water tank, and the other end is provided with an annular channel around the outer inclined guide section; The annular channel is equipped with multiple spaced-apart distribution pipes, with the ends of the distribution pipes located in the middle of the outer side of the outer inclined guide section.

[0015] On the other hand, the present invention also provides a wastewater treatment process, employing any of the above-mentioned integrated autotrophic denitrification equipment, the steps of which include: Step 1: Wastewater pretreatment. The wastewater to be treated is introduced into the water inlet unit of the equipment. The wastewater is treated by sedimentation and filtration in the water inlet unit to remove impurities and particulate matter. Step 2: Anaerobic treatment. The pretreated wastewater enters the anaerobic unit of the equipment. In the anaerobic environment provided by the anaerobic unit, macromolecular organic pollutants in the wastewater are separated. Step 3: Oxygen-limited treatment. After anaerobic treatment, the wastewater enters the oxygen-limited unit of the equipment. Through the limited aeration effect of the oxygen-limited unit, some organic pollutants and phosphorus in the wastewater are removed. Step 4: Autotrophic denitrification and simultaneous phosphorus removal treatment. After oxygen-limited treatment, the wastewater enters the equipment's autotrophic denitrification and simultaneous phosphorus removal unit, through which nitrogen and phosphorus are removed from the wastewater. Step 5: Effluent purification. After deep treatment, the wastewater enters the effluent unit of the equipment. The wastewater is settled again and residual impurities are separated in the effluent unit, and finally qualified wastewater is discharged.

[0016] This invention discloses an integrated autotrophic nitrogen removal equipment and wastewater treatment process. The integrated autotrophic nitrogen removal equipment, arranged in series along the treatment flow direction, shortens the wastewater transport path, reduces hydraulic losses, and achieves continuous and efficient wastewater treatment operation. The units are arranged adjacent to each other in the sequence of "pretreatment - anaerobic decomposition - oxygen-limiting adaptation - deep nitrogen and phosphorus removal - terminal sedimentation," which avoids interference from large organic molecules in subsequent reactions, creates a suitable water quality environment for deep treatment, and ultimately ensures effluent quality. Simultaneously, the integrated closed flow channel reduces the risk of wastewater leakage. Attached Figure Description

[0017] 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.

[0018] Figure 1 This is a schematic diagram of a structure of an embodiment of an integrated autotrophic nitrogen removal equipment for wastewater according to the present invention; Figure 2 This is a top plan view of an embodiment of an integrated autotrophic nitrogen removal equipment for wastewater according to the present invention; Figure 3 This is a schematic diagram of the anaerobic biological packing reaction zone of an integrated autotrophic nitrogen removal equipment for wastewater according to the present invention. Figure 4 This is a schematic diagram of an embodiment of the autotrophic nitrogen removal and simultaneous phosphorus removal unit of an integrated autotrophic nitrogen removal equipment for wastewater according to the present invention. Figure 5 This is a partial schematic diagram of an embodiment of the denitrification agent dosing component of the autotrophic denitrification and simultaneous phosphorus removal unit of the present invention; Figure 6 This is a schematic diagram of an embodiment of the propulsion assembly of the autotrophic denitrification and simultaneous phosphorus removal unit of the present invention; Figure 7 This is a schematic diagram of another embodiment of the autotrophic denitrification and simultaneous phosphorus removal unit of the present invention. Detailed Implementation

[0019] 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.

[0020] 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 may have 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 may have an intervening component present.

[0021] 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.

[0022] This invention provides an integrated autotrophic nitrogen removal equipment for wastewater, referenced Figure 1 and Figure 2 It includes: an influent unit A, an anaerobic unit B, an oxygen-limiting unit C, an autotrophic denitrification and simultaneous phosphorus removal unit D, and an effluent unit E connected in sequence. Each unit is arranged in series along the wastewater treatment flow direction and is connected in sequence through a connecting structure to form a closed treatment channel. The inlet unit is used for pretreatment sedimentation and filtration of wastewater, providing wastewater with impurities removed for subsequent units; The anaerobic unit, located adjacent to the influent unit, is used to provide an anaerobic environment to separate large molecular organic pollutants in wastewater, thus preventing large molecular organic matter from interfering with subsequent nitrogen and phosphorus removal reactions. The oxygen-limiting unit, located adjacent to the anaerobic unit, removes some organic pollutants and phosphorus from the wastewater by limiting aeration, creating a suitable water quality environment for the autotrophic nitrogen and phosphorus removal unit. The self-nutritive denitrification and simultaneous phosphorus removal unit is located adjacent to the oxygen-limiting unit and is used for the deep removal of nitrogen and phosphorus from wastewater. The effluent unit is located next to the autotrophic denitrification and simultaneous phosphorus removal unit. It is used to re-sediment the deeply treated wastewater and separate residual impurities to ensure the quality of the effluent.

[0023] This embodiment presents an integrated autotrophic denitrification system for wastewater. The integrated series arrangement along the treatment flow direction shortens the wastewater transport path, reduces hydraulic losses, and enables continuous and efficient wastewater treatment. The units are arranged adjacent to each other in the sequence of "pretreatment - anaerobic decomposition - oxygen-limited adaptation - deep denitrification and phosphorus removal - terminal sedimentation," which avoids interference from large organic molecules in subsequent reactions, creates a suitable water quality environment for deep treatment, and ultimately ensures effluent quality. Simultaneously, the integrated closed flow channel reduces the risk of wastewater leakage. In practical use, wastewater first undergoes preliminary filtration in the influent unit, separating larger impurities. Next, the wastewater enters the anaerobic unit, where anaerobic microorganisms convert large organic pollutants into smaller molecules, such as organic acids and ammonia nitrogen, providing favorable conditions for subsequent autotrophic denitrification and simultaneous phosphorus removal. Then, the oxygen-limited unit removes some organic matter and phosphorus, converting small organic molecules in the effluent from the anaerobic unit into carbon dioxide and water, significantly reducing the COD (Chemical Oxygen Demand) value in the effluent. Then, the wastewater enters the autotrophic denitrification and simultaneous phosphorus removal unit to complete the PNA reaction, achieving efficient denitrification and phosphorus removal. Finally, the wastewater passes through the effluent unit for further sedimentation and separation, resulting in integrated wastewater treatment. In summary, this invention provides an integrated autotrophic denitrification wastewater treatment system that is stable, reliable, economical, efficient, easy to operate, and highly integrated, capable of simultaneously removing nitrogen and phosphorus pollutants.

[0024] Preferred, Reference Figure 1 and Figure 2 The water inlet unit A includes a shell A1, a bar grid assembly A2, a sedimentation tank A3, and an inlet separator A4; The shell has an inlet at the top; a bar screen assembly is located below the inlet to intercept impurities in the incoming water; a sedimentation tank is connected to the downstream of the bar screen assembly, and the bottom of the sedimentation tank is set as a triangular sedimentation zone; and an inlet separator is located at the bottom of the triangular sedimentation zone to discharge sludge or particulate matter deposited in the triangular sedimentation zone.

[0025] More preferably, the shell of the inlet unit A is elongated with a length-to-diameter ratio of 5 to 10:1; the shell length is 1.5 to 3 m, and the cross-sectional width is 0.2 to 0.5 m. The elongated structure extends the residence time of the water flow in the sedimentation tank A3 to 15 to 30 minutes. The sedimentation tank A3 is inclined along the length of the shell, and the inclination angle matches the angle between the wall of the triangular sedimentation zone. The angle between the inclined wall of the triangular sedimentation zone and the horizontal plane is 50° to 70°. The bar assembly A2 is a detachable fine bar with a mesh width of 0.5 to 2 mm. An electric valve is installed at the inlet separation port A4, which is electrically connected to the sludge level sensor in the triangular sedimentation zone. A guide plate is also installed in the sedimentation tank A3, which is inclined along the inlet flow direction to guide the water flow evenly through the triangular sedimentation zone.

[0026] In this embodiment, wastewater first passes through a screen at the inlet to intercept larger impurities, such as leaves and plastic bags, preventing them from entering the sedimentation tank. The wastewater solution containing the larger impurities then enters the upper part of the first sedimentation tank. After preliminary filtration by the screen, under the influence of gravity, denser suspended particles (including granular sludge with a high inorganic content) gradually settle to the bottom, thus separating from the water. The settled sediment is discharged through the first separation port, achieving preliminary solid-liquid separation. The separated wastewater then enters the anaerobic unit from the first sedimentation tank, completing the preliminary filtration of the wastewater. The above-described preferred embodiments enable the bar screen assembly to efficiently intercept impurities in the incoming water, preventing them from entering subsequent treatment units and causing blockages. The slender shell, combined with the inclined sedimentation tank and triangular sedimentation zone, extends the hydraulic retention time and increases the sedimentation contact area, significantly improving particulate matter settling efficiency. The baffle guides the water flow uniformly, preventing localized turbulence from affecting the sedimentation effect. The linkage design between the electric valve and the sludge level sensor enables automatic discharge of deposited sludge without manual intervention, improving operational convenience. The overall structure achieves high efficiency and automation in wastewater pretreatment, providing stable influent water for subsequent anaerobic, nitrogen removal, and phosphorus removal units, ensuring the overall treatment effect of the equipment.

[0027] Preferred, Reference Figure 1 , Figure 2 and Figure 3 The dissolved oxygen concentration in the anaerobic unit is below 0.2 mg / L. The anaerobic unit includes: an anaerobic chamber; An anaerobic inlet B3 is provided on one side of the top of the anaerobic chamber, which is connected to the outlet of the sedimentation tank of the inlet unit. The anaerobic chamber is equipped with an anaerobic biological packing reaction zone B1 in the middle. The bottom of the anaerobic chamber is equipped with an anaerobic sludge discharge port B4. The bottom of the anaerobic chamber where the anaerobic sludge discharge port is located has a planar structure. This planar structure can avoid the local accumulation of sludge at the bottom and facilitate the centralized discharge of sludge, which is different from the problem of sludge residue caused by the pointed bottom structure. Anaerobic outlet B2 is located on the side wall of the anaerobic chamber, below the anaerobic biological packing reaction zone and above the plane where the anaerobic sludge discharge port is located. The anaerobic outlet is located here to allow the wastewater treated by the anaerobic biological packing reaction zone to flow out smoothly, while preventing the bottom sediment sludge from entering the subsequent unit with the water flow. Anaerobic unit B is connected to oxygen-limiting unit C through anaerobic outlet B2.

[0028] In this embodiment, wastewater is pretreated by the influent unit before entering the influent zone of the anaerobic unit. Optionally, the dissolved oxygen concentration in the anaerobic unit is below 0.2 mg / L, and the influent zone distributes the water flow evenly, ensuring that the wastewater enters the anaerobic biological packing reaction zone uniformly and stably. Since the anaerobic biological packing reaction zone contains biological packing units with anaerobic active microorganisms attached to them, an anaerobic biofilm is formed. Under the action of these anaerobic active microorganisms, large molecular organic pollutants in the wastewater are converted into smaller molecules, such as organic acids and ammonia nitrogen, reducing the concentration of large molecular organic pollutants in the wastewater. The treated wastewater then enters the oxygen-limiting unit uniformly and stably from the effluent zone, providing favorable conditions for subsequent nitrogen and phosphorus removal treatment. Furthermore, the granular sludge in the wastewater contains anaerobic active microorganisms and other functional microorganisms. Therefore, the active microorganisms on the biological packing material can be continuously replenished and renewed. The anaerobic biofilm attached to the surface of the biological packing material continuously forms, grows, matures, and ages. The aged anaerobic biofilm naturally detaches from the biological packing material and falls into the second separation port under gravity, thus treating the wastewater. The preferred design includes at least the following technical effects: First, the anaerobic inlet is located at the top of the anaerobic chamber and precisely connected to the outlet of the sedimentation tank in the inlet unit, allowing pre-treated wastewater to smoothly enter the anaerobic chamber, avoiding water flow impact that could disrupt the stability of the anaerobic environment and providing stable conditions for the growth and reproduction of anaerobic bacteria. Second, the anaerobic biological packing material's reaction zone is located in the middle of the chamber, maximizing the contact area between the packing material and the wastewater, promoting the enrichment of anaerobic bacteria, and efficiently decomposing large molecular organic pollutants in the wastewater into smaller molecules, reducing the pollutant load on subsequent treatment units. Third, the bottom adopts a planar structure design. Compared to traditional pointed-bottom structures, this design effectively prevents sludge from accumulating locally at the bottom, ensuring that the sludge is evenly distributed and concentrated near the anaerobic sludge discharge outlet. This improves the thoroughness of sludge discharge and reduces the impact of sludge residue on anaerobic reaction efficiency. Fourthly, the anaerobic effluent outlet B2 is located below the biological packing reaction zone and above the sludge discharge outlet plane. This design ensures that the wastewater treated by the anaerobic reaction flows out smoothly, while preventing the bottom-deposited sludge from entering the subsequent oxygen-limiting unit with the water flow. This avoids the decrease in treatment efficiency caused by sludge loss, ensures the stability of the wastewater quality entering the oxygen-limiting unit, and achieves efficient synergistic connection between anaerobic treatment and subsequent treatment units.

[0029] More preferably, refer to Figure 1 and Figure 3 Anaerobic biological packing reaction zone B10 includes support B11 and biological packing material B12; The supports are arranged at intervals and vertically installed within the anaerobic biological packing reaction zone; Biological packing material is arranged around the support structure; Active microorganisms are attached to the biological packing material.

[0030] In this embodiment, the biological packing material is distributed around the support, forming a three-dimensional structure that provides a large surface area. Active microorganisms attach to the surface of the biological packing material, forming a stable biofilm, allowing for sufficient attachment and reproduction. The microorganisms can efficiently degrade organic pollutants, improving wastewater treatment capacity. Because the support is spaced apart, wastewater can pass evenly through the packing layer, ensuring sufficient contact between organic pollutants and the attached microorganisms, thus improving degradation efficiency. More preferably, the support includes: hanging ropes and filaments, with the filaments arranged around the hanging ropes; activated sludge is attached to the filaments. The flexible structure of the filaments and hanging ropes makes the water flow more uniform, improving the stability of anaerobic treatment, and simultaneously allowing for a more complete and uniform reaction of the functional microorganisms, achieving better wastewater treatment results.

[0031] Preferably, the dissolved oxygen concentration range of the oxygen-limiting unit C is between 0.2 and 1.0 mg / L, including: oxygen-limiting chamber C2, oxygen-limiting aeration port C1 and oxygen-limiting sludge discharge port C3; An oxygen-limiting inlet is located below the oxygen-limiting chamber, which is connected to the anaerobic outlet B2 of anaerobic unit B; an oxygen-limiting outlet is located above the chamber, which is connected to the autotrophic denitrification and simultaneous phosphorus removal unit; so as to achieve water inlet at the bottom and water outlet at the top. The bottom of the oxygen-limiting chamber is equipped with an oxygen-limiting aeration port and an oxygen-limiting sludge discharge port; the oxygen-limiting chamber 52 is equipped with a vertical guide strip near the right side wall; it is used to guide the sewage to rise evenly and make full contact with the aeration airflow, avoiding dead zones in flow and improving treatment efficiency.

[0032] In this embodiment, wastewater treated by the anaerobic unit enters the oxygen-limiting chamber. At this point, the wastewater still contains a certain amount of organic matter and nitrogen and phosphorus pollutants. The oxygen-limiting aeration port is located at the lower end of the oxygen-limiting chamber, aerating upwards at a low aeration rate to maintain a low dissolved oxygen state in the system. The dissolved oxygen concentration range of the oxygen-limiting unit can be selected between 0.2 and 1.0 mg / L, providing adequate oxygen for microorganisms, allowing various functional microorganisms and their corresponding bacterial communities to coexist in the oxygen-limiting unit. Among them, polyphosphate-accumulating bacteria (a type of functional microorganism) excessively absorb phosphorus under aerobic conditions. Polyphosphate-accumulating bacteria utilize the remaining organic matter in the wastewater to multiply. Excessive polyphosphate-accumulating bacteria will aggregate into clumps, then settle and be discharged from the oxygen-limiting sludge discharge port at the lower end of the oxygen-limiting chamber, achieving partial phosphorus removal from the wastewater. At the same time, since polyphosphate-accumulating bacteria themselves can also consume organic matter, reducing the concentration of organic pollutants in the wastewater, they can adjust the carbon-nitrogen ratio in the wastewater while treating it, providing more favorable reaction conditions for the denitrification and phosphorus removal of the autotrophic denitrification and simultaneous phosphorus removal unit.

[0033] Preferably, to adapt to the integrated autotrophic nitrogen removal equipment and enhance the nitrogen removal effect, the autotrophic nitrogen removal and simultaneous phosphorus removal unit of this invention preferably adopts: a vertical flow enhanced biological nitrogen removal device, as described in the reference. Figures 4 to 7 It includes: outer cylinder 1, inner cylinder 2, flow guiding component 3, denitrification agent dosing component 4, and aeration component 5; The inner cylinder is connected to the outer cylinder and is divided into 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. The flow guiding assembly, connected to the axial bottom end of the inner cylinder, includes: an inner inclined flow guiding part 31, an outer inclined flow guiding part 32, a screen hole 33 provided on the side wall of the inner inclined flow guiding part, and a through hole 34 penetrating the flow guiding assembly; The denitrification agent dosing assembly is located outside the outer inclined guide section and is used for targeted dosing of enhanced denitrification agents; The aeration component is installed inside the outer inclined guide section and aerates upwards.

[0034] This embodiment presents the vertical flow enhanced biological denitrification device of the present invention. Its core feature is the addition of a denitrification agent dosing component outside the inner inclined guide section, which further improves the denitrification effect. This is because: a large amount of anaerobic ammonia oxidation granular sludge accumulates outside the outer inclined guide section, where the dissolved oxygen level is very low, even in a completely anaerobic state; simultaneously, the anaerobic ammonia oxidation reaction is highly reactive, producing a large amount of nitrate, which needs to be further reduced to nitrogen gas. Biological denitrification requires the addition of electron donors or carbon sources. The present invention, by precisely dosing enhanced denitrification agents at this location, can achieve precise control and multi-pathway denitrification, resulting in highly efficient and thorough denitrification.

[0035] Therefore, the key to this invention lies in adding a denitrification agent dosing component at a suitable location in the existing vertical flow reaction device, namely outside the outward-sloping guide section. This component allows for the addition of corresponding enhanced denitrification agents at selected points, further strengthening the denitrification reaction, improving the selectivity of the functional microbial reaction, consuming the nitrates produced by the anaerobic ammonium oxidation reaction, and providing sufficient substrate for anaerobic ammonium oxidation, thereby greatly promoting the anaerobic ammonium oxidation reaction and further improving the total nitrogen removal rate. By achieving precise control of the dosing location and accurately adding agents according to the reaction, the invention achieves a synergistic effect of minimizing agent dosage and maximizing denitrification efficiency while enhancing the denitrification efficiency of autotrophic organisms, ultimately achieving the goal of green, low-carbon, economical, and efficient denitrification of wastewater. The discovery and solution of this technical problem is a key technical concept of this invention.

[0036] Preferably, the denitrification agent dosing assembly 4 includes: a sensor 41, a control unit, and a dosing unit 42; A sensor is used to monitor reaction indicators within the device; a control unit, connected at one end to the sensor and at the other end to the dosing unit, is used to issue a dosing signal based on the reaction indicators; the dosing unit, located outside the inclined guide section, is used to precisely add denitrifying agent to the outside of the inclined guide section based on the dosing signal. Preferably, the control unit is used to control the dosing valve and dosing drive on the dosing unit.

[0037] More preferably, the sensors include a nitrate nitrogen concentration monitor, a dissolved oxygen concentration monitor, a sludge thickness monitor, and a sludge concentration monitor, used to detect nitrate nitrogen concentration, dissolved oxygen concentration, sludge concentration, and sludge thickness, respectively. The control unit is used to determine whether to add denitrification agents based on the nitrate concentration, and to determine the basic dosage based on the nitrate concentration when adding the agent; it also corrects the basic dosage based on the dissolved oxygen concentration, sludge concentration, and sludge thickness to determine the final dosage.

[0038] More preferably, the dosing unit 42 includes: an inlet pipe 421, and a dosing valve 422, a dosing drive 423, and a dosing water tank 424 sequentially disposed on the inlet pipe 421; Dosing actuator, used to drive the opening or closing of the dosing valve; One end of the feed pipe is connected to the dosing water tank, and the other end is provided with an annular channel 425 around the outer inclined guide section; The annular channel 425 is provided with multiple spaced distribution pipes 426, with the ends of the distribution pipes located in the middle of the outer side of the outer inclined guide section.

[0039] In this embodiment, the dosing inlet tank is used to buffer the enhanced denitrification agent. One end of the feed pipe is connected to the tank, serving as the agent delivery path between the dosing unit and the reaction zone. The other end has an annular channel surrounding the inclined guide section, which enables uniform circumferential dosing of the agent within the guide section. This avoids excessively high local concentrations that could impact the granular sludge, ensuring thorough mixing and diffusion of the enhanced denitrification agent during circulation, thereby improving denitrification efficiency and the denitrification reaction rate. Based on this, real-time monitoring data from the sensors is transmitted to the control unit, which in turn transmits it to the dosing drive. The dosing drive dynamically adjusts the flow rate of the enhanced denitrification agent in the feed pipe based on the real-time monitoring data from the dissolved oxygen sensor. Simultaneously, the control unit controls the opening and closing of the dosing valve, dynamically controlling the amount of enhanced denitrification agent added.

[0040] More preferably, refer to Figure 1 The vertical flow enhanced biological denitrifier further includes: a granular sludge retainer 9 hinged to the outer wall of the outer inclined guide section; the granular sludge retainer 9 is capable of flipping upwards. More preferably, the granular sludge retainer includes several blades at the same height on the outer wall of the outer inclined guide section; the blades are spaced apart, and the outlet of the feed pipe is located at the interval between pairs of blades.

[0041] In this embodiment, a granular sludge retainer is added to the outer inclined guide section to prevent large-diameter granular sludge from sliding directly or flowing too quickly, thereby slowing down its flow velocity and increasing the residence time of large-diameter granular sludge on the outer wall of the outer inclined guide section. This ensures that the large-diameter granular sludge can fully undergo anaerobic ammonia oxidation and denitrification reactions, improving the nitrogen removal rate. Simultaneously, since the granular sludge retainer is hinged to the outer wall of the outer inclined guide section, it can freely rotate through the hinge point. The granular sludge retainer has the strongest blocking ability for large-diameter granular sludge when it is perpendicular to the outer wall of the outer inclined guide section; and the weakest blocking ability when it is parallel to the outer wall of the outer inclined guide section. By adjusting the rotation angle of the granular sludge retainer, the blocking ability for large-diameter granular sludge can be adjusted, thereby adjusting the residence time of large-diameter granular sludge on the outer wall of the outer inclined guide section to adapt to the reaction time of large-diameter granular sludge with different concentrations, further improving the adjustability of the device.

[0042] More preferably, the vertical flow enhanced biological denitrification device further includes: a propulsion component 7 disposed in the inner inclined guide section, the propulsion component being used to propel the flow upward; preferably, the propulsion component is disposed in the first inner inclined guide section; The propulsion assembly 7 includes: a propulsion base plate 71, a propulsion bracket 72, a propulsion main shaft 73, a propulsion impeller 74, and a propulsion drive component 75; A flow-pushing base plate is located at the bottom end of the inner inclined flow guide section; The jet propulsion bracket is mounted on the jet propulsion base plate; The main propulsion shaft is located in the middle of the propulsion support; The impeller blades and the drive components are nested outside the main shaft.

[0043] In this embodiment, a propulsion assembly is added inside the inclined guide section of the vertical flow enhanced biological denitrification device. The aeration assembly and the propulsion assembly work together to propel the flow upwards, accelerating the upward flow along the bottom of the guide assembly, the through hole, and the inclined guide section, forming a stable segmented flow structure and optimizing the hydrodynamic performance of the liquid flow. In the propulsion assembly, the propulsion support and the propulsion base plate mainly serve a supporting role. The propulsion drive component drives the propulsion main shaft to rotate, which in turn drives the blades nested on the propulsion main shaft to rotate. The propulsion impeller blades rotate continuously and propel the flow upwards, accelerating the upward flow velocity of the sewage. In the sewage granular sludge system, the particulate matter carried in the sewage fluid will rise rapidly along the direction of fluid movement, exhibiting turbulent flow, and will be uniformly mixed with the enhanced denitrification agent, further improving the sewage circulation efficiency.

[0044] More preferably, the effluent unit includes: a sedimentation chamber E1 and a first effluent outlet E2 disposed above the inclined tube sedimentation assembly; preferably, a vertical guide plate is also disposed at the upper end of the side wall of the sedimentation chamber, and a sludge discharge outlet is disposed at the bottom end.

[0045] On the other hand, the present invention also provides a wastewater treatment process, employing any of the above-mentioned integrated autotrophic denitrification equipment, the steps of which include: Step 1: Wastewater pretreatment. The wastewater to be treated is introduced into the inlet unit A of the equipment. The wastewater is treated by sedimentation and filtration through the inlet unit to remove impurities and particulate matter from the water. Step 2: Anaerobic treatment. The pretreated wastewater enters the anaerobic unit B of the equipment. In the anaerobic environment provided by the anaerobic unit, macromolecular organic pollutants in the wastewater are separated. Step 3: Oxygen-limited treatment. After anaerobic treatment, the wastewater enters the oxygen-limited unit C of the equipment. Through the limited aeration effect of the oxygen-limited unit, some organic pollutants and phosphorus in the wastewater are removed. Step 4: Autotrophic denitrification and simultaneous phosphorus removal treatment. After oxygen-limited treatment, the wastewater enters the autotrophic denitrification and simultaneous phosphorus removal unit D of the equipment, through which nitrogen and phosphorus are removed from the wastewater. Step 5: Effluent purification. After deep treatment, the wastewater enters the effluent unit E of the equipment. The wastewater is settled again and residual impurities are separated in the effluent unit, and finally qualified wastewater is discharged.

[0046] This embodiment presents a wastewater treatment process that utilizes any of the aforementioned integrated autotrophic nitrogen removal equipment. It combines multiple treatment processes, including primary sedimentation, anaerobic treatment, oxygen-limited treatment, nitrogen and phosphorus removal, and secondary sedimentation, and achieves efficient removal of different pollutants through synergistic effects. In particular, the restricted aeration and low-oxygen environment of the oxygen-limited unit reduces the aeration volume required in the traditional activated sludge process, lowering energy consumption and enabling the system to maintain low operating costs while achieving high treatment efficiency. Specifically, the dissolved oxygen concentration in the anaerobic unit is below 0.2 mg / L, the dissolved oxygen concentration in the oxygen-limited unit is between 0.2 and 1.0 mg / L, and the dissolved oxygen concentration in the autotrophic nitrogen and phosphorus removal unit is below 1.0 mg / L, achieving better wastewater treatment results. More specifically, the hydraulic retention time of the influent unit is 30 min to 2 h; the hydraulic retention time of the anaerobic unit is 4 to 6 h; the hydraulic retention time of the oxygen-limiting unit is 0.5 to 2 h; and the hydraulic retention time of the autotrophic denitrification and simultaneous phosphorus removal unit is 0.5 to 4 h. In the autotrophic denitrification and simultaneous phosphorus removal unit, the granular sludge retention time is 1 to 5 days to ensure that the wastewater treatment reaction proceeds fully and achieves better wastewater treatment results.

[0047] The above-described wastewater treatment process is based on the aforementioned integrated autotrophic nitrogen removal equipment. The combination of its technical effects and features will not be elaborated further here. The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively 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 all fall within the protection scope of the present invention.

Claims

1. An integrated autotrophic nitrogen removal equipment for wastewater, characterized in that, include: The influent unit, anaerobic unit, oxygen-limiting unit, autotrophic nitrogen and phosphorus removal unit and effluent unit are connected in sequence. Each unit is arranged in series along the sewage treatment flow direction and is connected in sequence through a connecting structure to form a closed treatment channel. The influent unit is used for pretreatment sedimentation and filtration of wastewater, providing wastewater with impurities removed for subsequent units; the anaerobic unit, located adjacent to the influent unit, is used to provide an anaerobic environment to separate large molecular organic pollutants in the wastewater, preventing large molecular organic matter from interfering with subsequent denitrification and phosphorus removal reactions; the oxygen-limiting unit, located adjacent to the anaerobic unit, removes some organic pollutants and phosphorus from the wastewater by limiting aeration, creating a suitable water quality environment for the autotrophic denitrification and simultaneous phosphorus removal unit. The autotrophic nitrogen and phosphorus removal unit, located adjacent to the oxygen-limiting unit, is used for deep removal of nitrogen and phosphorus from wastewater. It includes an outer cylinder, an inner cylinder, a flow guiding assembly, a nitrogen removal agent dosing assembly, and an aeration assembly. The inner cylinder is connected to the outer cylinder, divided into an inner reaction chamber located inside the inner cylinder and an outer reaction chamber located between the inner and outer cylinders. The flow guiding assembly, connected to the axial bottom end of the inner cylinder, includes an inner inclined flow guiding section, an outer inclined flow guiding section, sieve holes on the side wall of the inner inclined flow guiding section, and through holes penetrating the flow guiding assembly. The nitrogen removal agent dosing assembly, located outside the outer inclined flow guiding section, is used for targeted dosing of enhanced nitrogen removal agents. The aeration assembly, located inside the outer inclined flow guiding section, aerates upwards. The effluent unit is located next to the autotrophic denitrification and simultaneous phosphorus removal unit. It is used to re-sediment the deeply treated wastewater and separate residual impurities to ensure the quality of the effluent.

2. The integrated wastewater autotrophic denitrification equipment according to claim 1, characterized in that, The water inlet unit includes a housing, a bar screen assembly, a sedimentation tank, and an inlet separator. The shell has an inlet at the top; a bar screen assembly is located below the inlet to intercept impurities in the incoming water; a sedimentation tank is connected to the downstream of the bar screen assembly, and the bottom of the sedimentation tank is set as a triangular sedimentation zone; and an inlet separator is located at the bottom of the triangular sedimentation zone to discharge sludge or particulate matter deposited in the triangular sedimentation zone.

3. The integrated wastewater autotrophic denitrification equipment according to claim 2, characterized in that, The inlet unit has a slender shell with a length-to-diameter ratio of 5-10:1; the shell length is 1.5-3m and the cross-sectional width is 0.2-0.5m. The slender structure extends the residence time of water in the sedimentation tank to 15-30 minutes. The sedimentation tank is inclined along the length of the shell, and the inclination angle matches the wall angle of the triangular sedimentation zone. The angle between the inclined wall of the triangular sedimentation zone and the horizontal plane is 50°-70°. The bar screen assembly is a detachable fine bar screen with a mesh width of 0.5-2mm. An electric valve is installed at the inlet separation port, which is electrically connected to the sludge level sensor in the triangular sedimentation zone. A guide plate is also installed in the sedimentation tank, which is inclined along the inlet flow direction to guide the water flow evenly through the triangular sedimentation zone.

4. The integrated wastewater autotrophic denitrification equipment according to claim 3, characterized in that, The anaerobic unit includes: an anaerobic chamber; An anaerobic inlet is provided on one side of the top of the anaerobic chamber, which is connected to the outlet of the sedimentation tank of the inlet unit; The anaerobic chamber is equipped with an anaerobic biological packing reaction zone in the middle. The bottom of the anaerobic chamber is equipped with an anaerobic sludge discharge port, and the bottom of the anaerobic chamber where the anaerobic sludge discharge port is located has a planar structure. An anaerobic outlet is located on the side wall of the anaerobic chamber below the anaerobic biological packing reaction zone and above the plane where the anaerobic sludge discharge port is located, and it is connected to the oxygen-limiting unit.

5. The integrated wastewater autotrophic denitrification equipment according to claim 4, characterized in that, The anaerobic biological packing reaction zone includes a support structure and biological packing material; The supports are arranged at intervals and vertically installed within the anaerobic biological packing reaction zone; Biological packing material is arranged around the support structure; Active microorganisms are attached to the biological packing material.

6. The integrated wastewater autotrophic denitrification equipment according to claim 2, characterized in that, The oxygen-limiting unit includes: an oxygen-limiting chamber, an oxygen-limiting aeration port, and an oxygen-limiting sludge discharge port; An oxygen-limiting inlet is located at the bottom of the oxygen-limiting chamber, which is connected to the anaerobic outlet of the anaerobic unit; an oxygen-limiting outlet is located at the top, which is connected to the autotrophic denitrification and phosphorus removal unit; so as to achieve water inlet at the bottom and water outlet at the top. The bottom of the oxygen-limiting chamber is equipped with an oxygen-limiting aeration port and an oxygen-limiting sludge discharge port; a vertical guide strip is installed near the right side wall of the oxygen-limiting chamber; this is used to guide the sewage to rise evenly and make full contact with the aeration airflow, avoiding dead zones and improving treatment efficiency.

7. The integrated wastewater autotrophic denitrification equipment according to claim 1, characterized in that, The denitrification agent dosing assembly includes: a sensor, a control unit, and a dosing unit; The sensor is used to monitor the reaction indicators within the device; the control unit is connected to the sensor at one end and to the dosing unit at the other end, and is used to issue a dosing signal based on the reaction indicators; the dosing unit is located on the outside of the inclined guide section, and is used to add denitrification agent to the outside of the inclined guide section at a fixed point based on the dosing signal. The control unit is used to control the dosing valves and dosing drive components on the dosing unit.

8. The integrated wastewater autotrophic denitrification equipment according to claim 7, characterized in that, The dosing unit includes: an inlet pipe, and a dosing valve, a dosing drive, and a dosing water tank arranged sequentially on the inlet pipe; Dosing actuator, used to drive the opening or closing of the dosing valve; One end of the feed pipe is connected to the dosing water tank, and the other end is provided with an annular channel around the outer inclined guide section; The annular channel is equipped with multiple spaced-apart distribution pipes, with the ends of the distribution pipes located in the middle of the outer side of the outer inclined guide section.

9. The integrated wastewater autotrophic denitrification equipment according to claim 8, characterized in that, The autotrophic denitrification and simultaneous phosphorus removal unit also includes: a granular sludge retainer hinged to the outer wall of the outer inclined guide section; the granular sludge retainer can be flipped upwards; the granular sludge retainer includes several blades at the same height on the outer wall of the outer inclined guide section; the several blades are spaced apart, and the outlet of the feed pipe is located at the interval between two blades.

10. A wastewater treatment process, characterized in that, The wastewater autotrophic denitrification integrated equipment according to any one of claims 1 to 9 includes the following steps: Step 1: Wastewater pretreatment. The wastewater to be treated is introduced into the water inlet unit of the equipment. The wastewater is treated by sedimentation and filtration in the water inlet unit to remove impurities and particulate matter. Step 2: Anaerobic treatment. The pretreated wastewater enters the anaerobic unit of the equipment. In the anaerobic environment provided by the anaerobic unit, macromolecular organic pollutants in the wastewater are separated. Step 3: Oxygen-limited treatment. After anaerobic treatment, the wastewater enters the oxygen-limited unit of the equipment. Through the limited aeration effect of the oxygen-limited unit, some organic pollutants and phosphorus in the wastewater are removed. Step 4: Autotrophic denitrification and simultaneous phosphorus removal treatment. After oxygen-limited treatment, the wastewater enters the equipment's autotrophic denitrification and simultaneous phosphorus removal unit, through which nitrogen and phosphorus are removed from the wastewater. Step 5: Effluent purification. After deep treatment, the wastewater enters the effluent unit of the equipment. The wastewater is settled again and residual impurities are separated in the effluent unit, and finally qualified wastewater is discharged.

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