Integrated sewage denitrification treatment system and treatment method

Abstract

The invention provides an integrated sewage denitrification treatment system and a treatment method. The system comprises a reactor, a water inlet pipeline, a water outlet pipeline and a controller, the reactor is sequentially divided into a pretreatment zone, a coupling reaction zone and a water outlet buffer zone from top to bottom; the inlet of the water outlet pipeline is communicated with the water outlet buffer area; the pretreatment area is communicated with the coupling reaction area through a first pipeline; the coupling reaction zone is communicated with the water outlet buffer zone through a second pipeline; the coupling reaction area comprises a plurality of MABR membrane assemblies and a plurality of iron-carbon filler layers which are arranged in a staggered mode, and the first iron-carbon filler layer is located above the first MABR membrane assembly; a water quality monitor is arranged on the water outlet pipeline; the controller is connected with the water quality monitor; the controller is used for adjusting the working parameters of the coupling reaction area according to the water quality condition monitored by the water quality monitor. The system can realize high-efficiency denitrification of sewage.

Description

Technical Field

[0001] This invention belongs to the field of wastewater denitrification technology, specifically to an integrated wastewater denitrification treatment system and method. Background Technology

[0002] In water-scarce regions, the volume of domestic sewage discharge is increasing year by year. In some remote areas, due to the small volume and scattered distribution of sewage, centralized sewage treatment facilities are difficult to cover, resulting in prominent problems of direct sewage discharge. Traditional sewage treatment processes, such as the AO process, have drawbacks such as high energy consumption, high carbon emissions, and low denitrification efficiency under low carbon-to-nitrogen ratio conditions, making it difficult to meet the "dual carbon" targets and the needs of water resource recycling.

[0003] In view of this, the present invention is hereby proposed. Summary of the Invention

[0004] The primary objective of this invention is to provide an integrated wastewater denitrification treatment system. This system can reduce the system's footprint while achieving the technical effects of efficient and stable denitrification without the need for external carbon sources, stable effluent quality, intelligent operation, and high space utilization. It is suitable for solving the problems of decentralized domestic sewage and high ammonia nitrogen wastewater treatment.

[0005] The second objective of this invention is to provide a wastewater denitrification treatment method that is simple to operate and can effectively achieve wastewater denitrification.

[0006] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: This invention provides an integrated wastewater denitrification treatment system, comprising: a reactor, an inlet pipe, an outlet pipe, and a controller; The reactor is divided into a pretreatment zone, a coupled reaction zone, and an effluent buffer zone from top to bottom; the outlet of the inlet pipe is connected to the pretreatment zone, and the inlet of the effluent pipe is connected to the effluent buffer zone; the pretreatment zone is connected to the coupled reaction zone through a first pipe; and the coupled reaction zone is connected to the effluent buffer zone through a second pipe. The coupling reaction zone includes multiple MABR membrane modules and multiple iron-carbon filler layers arranged in an alternating manner, wherein the first iron-carbon filler layer is located above the first MABR membrane module. A water quality monitor is installed on the outlet pipeline, and the controller is connected to the water quality monitor; the controller is used to adjust the operating parameters of the coupling reaction zone according to the water quality monitored by the water quality monitor.

[0007] The integrated wastewater denitrification system described above achieves efficient and stable wastewater denitrification through a combination of modular zoning design and intelligent control. Structurally, the reactor is divided into a pretreatment zone, a coupled reaction zone, and an effluent buffer zone, forming a stepped treatment process. The pretreatment zone initially intercepts and homogenizes the wastewater, laying a stable water quality foundation for subsequent denitrification reactions. The coupled reaction zone employs an alternating layout of MABR membrane modules and iron-carbon packing layers, with the first iron-carbon packing layer located above the first MABR membrane module. This utilizes the micro-electrolysis effect of the iron-carbon packing to break down the structure of recalcitrant organic matter in the wastewater and improve its biodegradability, while also leveraging the efficient oxygen transfer characteristics of the MABR membrane module to support functional microorganisms such as nitrifying bacteria. The system provides ample oxygen to promote the synergistic nitrification-denitrification reaction, significantly enhancing nitrogen removal efficiency. Simultaneously, the staggered design increases the contact area between wastewater and functional materials and microorganisms, reducing treatment dead zones. This organic coupling of MABR technology with iron-carbon autotrophic denitrification technology creates a synergistic aerobic nitrification-heterotrophic denitrification-autotrophic denitrification reaction system within the coupled reaction zone. This achieves highly efficient total nitrogen removal without the need for an external carbon source, solving the problem of nitrogen removal from wastewater with a low carbon-to-nitrogen ratio. The effluent buffer zone further stabilizes effluent quality, preventing subsequent pipeline blockage or water quality fluctuations. From an intelligent control perspective, the water quality monitor in the effluent pipeline captures effluent water quality data in real time. The controller dynamically adjusts the operating parameters of the coupled reaction zone (such as membrane module air supply and wastewater retention time) based on the monitoring results. This not only optimizes treatment conditions promptly when water quality fails to meet standards, ensuring stable effluent compliance, but also avoids energy and material waste, achieving a balance between system economy and reliability. In summary, through structural optimization and technological coupling, this system can achieve the technical effects of efficient and stable denitrification without the need for external carbon sources, stable effluent quality, intelligent operation, and high space utilization while reducing the system's footprint. It is suitable for solving the problems of decentralized domestic sewage and high ammonia nitrogen wastewater treatment.

[0008] Preferably, the water quality includes effluent COD value, effluent ammonia nitrogen value, and effluent total nitrogen value; a reaction zone effluent control valve is installed on the second pipeline; The step of adjusting the operating parameters of the coupled reaction zone based on the water quality monitored by the water quality monitor includes: adjusting the effluent control valve of the reaction zone to reduce the effluent flow rate of the second pipeline when at least one of the effluent COD value, the effluent ammonia nitrogen value and the effluent total nitrogen value is greater than the corresponding threshold.

[0009] The above-mentioned solution focuses water quality monitoring on three core pollution indicators: effluent COD, effluent ammonia nitrogen, and effluent total nitrogen. This allows for precise capture of the water purification effect in the coupled reaction zone. When the wastewater purification effect does not meet expectations, the effluent flow rate in the coupled reaction zone can be adaptively adjusted to extend the residence time of wastewater within the zone. This provides more sufficient reaction time for the purification reaction within the zone, thereby improving the removal efficiency of pollutants, effectively improving the effluent quality, and ensuring that the wastewater indicators for final discharge or subsequent treatment meet the set standards. This achieves dynamic and precise optimization of the operating status of the coupled reaction zone, ensuring that the water treatment system can stably and efficiently perform its purification function.

[0010] Preferably, the pretreatment zone includes multiple layers of screens, which are inclined downwards along the direction away from the inlet pipe, and the ribs of adjacent layers of screens are staggered. On the one hand, the inclined structure can guide the water flow and intercepted objects to move downwards naturally by gravity, avoiding the accumulation of intercepted impurities on the screen surface and causing blockage, thus improving water flow efficiency and reducing the frequency of manual cleaning. On the other hand, the staggered ribs of adjacent layers can form a denser, gapless interception net, effectively reducing the gap size of a single interception. This ensures the graded interception effect of impurities of different particle sizes (such as larger suspended solids, fibrous debris, etc.), preventing small impurities from passing through the filter screen into subsequent treatment stages. It also reduces the load on a single layer of screen through layered load-bearing, extending the overall service life of the screen. Ultimately, this provides cleaner and more stable inlet water conditions for subsequent water treatment processes, improving the operational reliability and treatment efficiency of the entire water treatment system.

[0011] Preferably, a water level sensor is installed in the pretreatment zone, and a pretreatment outlet water control valve is installed on the first pipeline; the controller is connected to the water level sensor and the pretreatment outlet water control valve respectively. The controller is also configured to: open the pre-treatment water outlet control valve when the water level sensor detects that the liquid level in the pre-treatment zone has reached the preset upper limit of the liquid level; and close the pre-treatment water outlet control valve when the water level sensor detects that the liquid level in the pre-treatment zone has dropped to the preset lower limit of the liquid level.

[0012] The above solution can automatically adjust the start and stop of effluent discharge based on the water level in the pretreatment zone. Specifically, when the water level sensor detects that the liquid level in the pretreatment zone has reached the preset upper limit, the controller can promptly trigger and open the pretreatment effluent control valve to avoid the risk of overflow or equipment overload caused by excessively high liquid levels. Conversely, when the liquid level drops to the preset lower limit, the controller can quickly close the control valve to prevent subsequent treatment stages from experiencing interruptions or idling due to excessively low liquid levels. This effectively ensures the continuity and stability of the pretreatment process, reduces reliance on manual monitoring and operation, and improves the automation and reliability of the overall system operation. In summary, this solution can balance the wastewater volume, preventing subsequent equipment from overloading due to sudden increases in water volume or idling or insufficient treatment due to sudden decreases in water volume. It is suitable for scenarios with significant intermittent and fluctuating wastewater discharge, such as remote areas in Xinjiang and rural areas.

[0013] Preferably, the system further includes an acid-base dosing pump, the outlet of which is connected to the pretreatment zone; a pH meter is installed in the pretreatment zone; and the controller is connected to both the acid-base dosing pump and the pH meter. The controller is also configured to: when the pH value of the wastewater in the pretreatment zone detected by the pH meter is not within the preset acidity / alkalinity range, control the acid / alkalinity dosing pump to add reagents to the pretreatment zone so that the pH value of the wastewater is maintained within the preset acidity / alkalinity range.

[0014] The above scheme, by setting up acid and alkali dosing pumps and pH meters, and dynamically controlling the dosing of acid and alkali dosing pumps based on the pH value of the wastewater collected by the pH meter, can ensure that the pH value of the wastewater entering the coupled reaction zone is stable within a certain range. This provides a suitable acid and alkali environment for the reaction in the coupled reaction zone, ensuring wastewater treatment efficiency and effect.

[0015] Preferably, it also includes an aeration pump; the bottom of the MABR membrane module is provided with multiple aeration distributors, and the aeration pump is connected to the aeration distributors.

[0016] The above solution, through the rational layout of multiple distributors, can evenly deliver gas to the bottom area of ​​the MABR membrane module, increasing the aeration efficiency to 3-4 times that of conventional systems, increasing the dissolved oxygen content in the water, creating a sufficient aerobic environment for aerobic microorganisms in the MABR membrane module, promoting the degradation efficiency of organic pollutants in the water by microorganisms, and thus significantly optimizing the purification capacity and operational stability of the overall water treatment system.

[0017] Preferably, the water quality includes dissolved oxygen content; the controller is connected to the aeration pump; The controller is further configured to: determine whether the dissolved oxygen content is within a preset oxygen content range; increase the aeration rate of the aeration pump when the dissolved oxygen content is lower than the lower limit of the preset oxygen content range; and decrease the aeration rate of the aeration pump when the dissolved oxygen content is higher than the upper limit of the preset oxygen content range.

[0018] The above scheme uses dissolved oxygen content in water quality monitoring as the core control indicator, and constructs a linkage control logic between the controller and the aeration pump to achieve precise dynamic closed-loop management of dissolved oxygen levels in the water. This mode can effectively reduce the energy consumption of aeration pumps while ensuring that dissolved oxygen in the water is stably maintained within a suitable preset range. It not only guarantees the stability of the aquatic ecological environment and the normal survival needs of aquatic organisms, but also promotes the upgrading of aeration systems towards energy conservation, significantly improving the intelligence and efficiency of water quality control.

[0019] Preferably, the iron-carbon packing layer includes a detachable packing box, and the reactor sidewall is provided with an insertion port. The detachable packing box is inserted into the reactor along the insertion port. The detachable packing box is filled with iron-carbon packing. Preferably, the particle size of the iron-carbon packing is in the range of [3mm, 8mm]. The iron-carbon mass ratio of the iron-carbon packing is (1-3):1.

[0020] The above-mentioned solution adopts a modular design for the iron-carbon packing layer, which enables convenient disassembly and installation of the iron-carbon packing. This allows for the rapid extraction of the detachable packing box for packing replacement or regeneration when the iron-carbon packing experiences decreased activity, caking, or needs replacement due to long-term reaction. This avoids the problem of needing to shut down and disassemble the internal structure of the reactor as required by traditional fixed packing layers, significantly shortening the equipment maintenance cycle and reducing the impact of downtime on treatment efficiency. At the same time, it allows for precise and targeted maintenance of different layers of packing, ensuring that the iron-carbon packing is always in a highly efficient reaction state, thereby improving the overall operational stability of the reactor and the pollutant treatment effect.

[0021] In a further scheme, the particle size and iron-carbon mass ratio of the iron-carbon filler are specifically defined. A particle size of 3mm to 8mm can ensure that uniform and appropriate pore channels are formed between the filler particles in the tank. This avoids the filler caking and blockage of water flow caused by the particle size being too small, and also prevents the reaction surface area from being insufficient due to the particle size being too large. This ensures that the wastewater and the filler are in full contact to improve the degradation efficiency. The iron-carbon mass ratio of (1-3):1 can precisely control the intensity of the micro-electrolysis reaction. While ensuring the removal effect of pollutants, it avoids the problem of excessive consumption of elemental iron leading to a surge in sludge.

[0022] Preferably, it further includes an internal circulation pipeline, the inlet and outlet of which are both connected to the sidewall of the coupling reaction zone; the inlet of the internal circulation pipeline is located below the plurality of iron-carbon packing layers, and the outlet of the internal circulation pipeline is located above the plurality of iron-carbon packing layers; Preferably, an internal circulation flow regulating valve is provided on the internal circulation pipeline; the controller is connected to the internal circulation flow regulating valve.

[0023] The above-mentioned scheme drives the treated wastewater in the coupled reaction zone to circulate internally through an internal circulation pipeline. This extends the contact time between the fluid and the iron-carbon packing material and MABR membrane module, improving the adsorption and catalytic degradation efficiency of pollutants in the fluid and avoiding insufficient treatment due to insufficient local fluid residence time. Simultaneously, an internal circulation flow regulating valve is installed on the internal circulation pipeline and connected to a controller for precise adjustment of the internal circulation flow rate based on the actual treatment needs of the coupled reaction zone (such as fluid pollutant concentration, treatment volume, and packing reaction state). This allows for dynamic control of the fluid circulation intensity, ensuring that the treatment effect is enhanced by increasing the circulation volume under high pollution loads, while reducing energy consumption by decreasing the circulation volume under low pollution loads. This further improves the operational flexibility, stability, and energy efficiency of the entire treatment system.

[0024] The present invention also provides a wastewater denitrification treatment method, which uses the above-described system to treat wastewater.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. By setting up a pretreatment zone, wastewater can be initially intercepted and homogenized, laying a stable water quality foundation for subsequent denitrification reactions; 2. By setting up a coupled reaction zone with an alternating layout of MABR membrane modules and iron-carbon packing layers, with the first iron-carbon packing layer located above the first MABR membrane module, the micro-electrolysis effect of the iron-carbon packing layer is utilized to break down the structure of recalcitrant organic matter in wastewater and improve its biodegradability. At the same time, the efficient oxygen transfer characteristics of the MABR membrane module provide sufficient oxygen for functional microorganisms such as nitrifying bacteria, promoting the synergistic nitrification-denitrification reaction and significantly enhancing nitrogen removal efficiency. Meanwhile, the alternating design increases the contact area between wastewater and functional materials and microorganisms, reducing treatment dead zones. In short, this method of organically coupling MABR technology with iron-carbon autotrophic denitrification technology can form an aerobic nitrification-heterotrophic denitrification-autotrophic denitrification synergistic reaction system in the coupled reaction zone, achieving efficient total nitrogen removal without the need for an external carbon source, and solving the problem of nitrogen removal from wastewater with a low carbon-to-nitrogen ratio. 3. Setting up an outlet buffer zone can further stabilize the outlet water quality and prevent subsequent pipe blockage or water quality fluctuations; 4. The water quality monitor in the outlet pipeline can capture the water quality data in real time. The controller dynamically adjusts the working parameters of the coupled reaction zone (such as the air supply of the membrane module and the sewage retention time) based on the monitoring results. This can not only optimize the treatment conditions in time when the water quality does not meet the standards, ensuring that the effluent meets the standards, but also avoid the waste of energy and materials, and achieve a balance between the economy and reliability of the system operation. 5. In summary, through structural optimization and technological coupling, this system can achieve the technical effects of efficient and stable denitrification without the need for external carbon sources, stable effluent quality, intelligent operation, and high space utilization while reducing the system's footprint. It is suitable for solving the problems of decentralized domestic sewage and high ammonia nitrogen wastewater treatment. Attached Figure Description

[0026] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A schematic diagram of the processing system according to an embodiment of the present invention is shown.

[0027] The components are as follows: 1. Inlet pipe; 2. Inlet pump; 3. Inlet flow regulating valve; 4. Check valve; 5. Reactor; 6. Bar screen; 7. Acid / alkali dosing pump; 8. Water level sensor; 9. pH meter; 10. Pretreatment zone; 11. Pretreatment effluent control valve; 12. Pretreatment effluent pump; 13. First pipeline; 14. Coupled reaction zone; 15. Iron-carbon packing layer; 16. MABR membrane module; 17. Aeration distributor; 18. Internal circulation flow regulating valve; 19. Aeration pump; 20. Internal circulation pump; 21. Internal circulation pipeline; 22. Second pipeline; 23. Reaction zone effluent pump; 24. Reaction zone effluent control valve; 25. Effluent buffer zone; 26. Effluent pipeline; 27. Drain pump; 28. Drain valve; 29. ​​Water quality monitor; 30. Controller. Detailed Implementation

[0028] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] To more clearly illustrate the technical solutions in this invention, specific embodiments are described below.

[0030] Example like Figure 1 As shown, this embodiment provides an integrated wastewater denitrification treatment system, including: a reactor 5, an inlet pipe 1, an outlet pipe 26, and a controller 30. The reactor 5 has a sealed structure with an effective volume of not less than 5m³. 3The reactor 5 is made of stainless steel, which is corrosion-resistant and has high strength. From top to bottom, the reactor 5 is divided into a pretreatment zone 10, a coupled reaction zone 14, and an effluent buffer zone 25. The outlet of the inlet pipe 1 connects to the pretreatment zone 10, and the inlet of the outlet pipe 26 connects to the effluent buffer zone 25. The pretreatment zone 10 is connected to the coupled reaction zone 14 via a first pipe 13; the coupled reaction zone 14 is connected to the effluent buffer zone 25 via a second pipe 22. In a specific embodiment, the reactor 5 can be made of 304 stainless steel, with an overall cylindrical structure, a diameter of 1.8m, a height of 2.0m, and an effective volume of 5m³. Internally, it is divided into a pretreatment zone 10 (0.3m high), a coupled reaction zone 14 (1.3m high), and an effluent buffer zone 25 (0.4m high).

[0031] A water quality monitor 29 is installed on the outlet pipe 26, and a controller 30 is connected to the water quality monitor 29. The controller 30 is used to adjust the operating parameters of the coupled reaction zone 14 according to the water quality monitored by the water quality monitor 29. Specifically, the water quality may include the effluent COD value, effluent ammonia nitrogen value, and effluent total nitrogen value. A reaction zone outlet control valve 24 is installed on the second pipe 22. The operating parameters of the coupled reaction zone 14 are adjusted according to the water quality monitored by the water quality monitor 29, including: when at least one of the effluent COD value, effluent ammonia nitrogen value, and effluent total nitrogen value is greater than the corresponding threshold, the reaction zone outlet control valve 24 is adjusted to reduce the outlet flow rate of the second pipe 22. In one specific embodiment, the water quality monitor 29 can be configured as an online COD monitor (detection range 0-500mg / L), an online ammonia nitrogen monitor 62 (0-100mg / L), and an online total nitrogen monitor 63 (0-100mg / L). The controller 30 can be a Siemens S7-200 PLC controller 30 to achieve automatic parameter control.

[0032] The pretreatment zone 10 includes multiple layers of screens 6, which are inclined downwards along the direction away from the inlet pipe 1, and the ribs of adjacent layers of screens 6 are staggered. In actual use, these screens 6 can remove suspended solids and large particulate impurities from wastewater, reducing the impact on subsequent reaction units.

[0033] Continue reading Figure 1 A water level sensor 8 is installed in the pretreatment zone 10, and a pretreatment outlet water control valve 11 is installed on the first pipeline 13. A controller 30 is connected to both the water level sensor 8 and the pretreatment outlet water control valve 11. The controller 30 can be used to: open the pretreatment outlet water control valve 11 when the water level sensor 8 detects that the liquid level in the pretreatment zone 10 has reached the preset upper limit; and close the pretreatment outlet water control valve 11 when the water level sensor 8 detects that the liquid level in the pretreatment zone 10 has dropped to the preset lower limit. The number of water level sensors 8 can be set to two to detect the upper and lower limits of the water level respectively. The upper and lower limits can be selected according to the actual working scenario and will not be elaborated further.

[0034] The system in this embodiment also includes an acid-base dosing pump 7, the outlet of which is connected to a pretreatment zone 10. A pH meter 9 is installed in the pretreatment zone 10. A controller 30 is connected to both the acid-base dosing pump 7 and the pH meter 9. The controller 30 is also used to: when the pH value of the wastewater in the pretreatment zone 10, as detected by the pH meter 9, is not within a preset pH range, control the acid-base dosing pump 7 to add reagents to the pretreatment zone 10 to maintain the pH value of the wastewater within the preset pH range. In this embodiment, the acid-base dosing pump 7 can automatically add acid / base according to the pH value of the wastewater. The preset pH range can be 6.5-8.5. In addition, a temperature control device can also be installed in the pretreatment zone 10 to ensure that the wastewater temperature is maintained within the range of 20-35℃, further ensuring that the subsequent coupling reaction occurs fully.

[0035] The coupling reaction zone 14 includes multiple MABR membrane modules 16 and multiple iron-carbon filler layers 15 arranged in an alternating manner, wherein the first iron-carbon filler layer 15 is located above the first MABR membrane module 16. Figure 1 In this design, there are three MABR membrane modules 16 and four iron-carbon filler layers 15. The MABR membrane modules 16 can be made of hydrophilically treated hollow fiber membranes and are fixed by a support structure. (The last sentence appears to be incomplete and possibly refers to a different design.) Figure 1 In the specific embodiment shown, polyvinylidene fluoride (PVDF) hollow fiber membranes are selected and hydrophilic modification treatment is performed. Each membrane module contains 1000 membrane filaments (2m in length, 0.8mm in outer diameter, 0.4mm in inner diameter, and 0.2μm in membrane pore size). A total of 3 modules are installed and fixed to the coupling reaction zone 14 by a bracket.

[0036] The system in this embodiment also includes an aeration pump 19; a plurality of aeration distributors 17 are provided at the bottom of the MABR membrane module 16, and the aeration pump 19 is connected to the aeration distributors 17. The aeration pump 19 can be a Roots blower (air pressure 0.04MPa, air volume 2.0m³ / min).

[0037] In this embodiment, the water quality condition also includes dissolved oxygen content; the controller 30 is connected to the aeration pump 19; the controller 30 is also used to: determine whether the dissolved oxygen content is within a preset oxygen content range; when the dissolved oxygen content is lower than the lower limit of the preset oxygen content range, increase the aeration rate of the aeration pump 19; when the dissolved oxygen content is higher than the upper limit of the preset oxygen content range, decrease the aeration rate of the aeration pump 19. The preset oxygen content range can be selected according to actual needs, and will not be elaborated further.

[0038] Continue reading Figure 1The iron-carbon packing layer 15 includes a removable packing box. An insertion port is provided on the side wall of the reactor 5, and the removable packing box is inserted into the reactor 5 through the insertion port. The removable packing box is filled with iron-carbon packing. In this embodiment, the particle size of the iron-carbon packing can be within the range of [3mm, 8mm]; the iron-carbon mass ratio of the iron-carbon packing can be (1-3):1. In a specific implementation, the iron-carbon mass ratio is 2:1, and the particle size is 5mm. The dimensions of the removable packing box are 1m × 0.5m × 1.2m, the packing stack height is 1.0m, and the packing density is 120kg / m³.

[0039] Continue reading Figure 1 The system also includes an internal circulation pipeline 21, the inlet and outlet of which are both connected to the side wall of the coupling reaction zone 14; the inlet of the internal circulation pipeline 21 is located below the multiple iron-carbon packing layers 15, and the outlet of the internal circulation pipeline 21 is located above the multiple iron-carbon packing layers 15; an internal circulation flow regulating valve 18 is installed on the internal circulation pipeline 21; the controller 30 is connected to the internal circulation flow regulating valve 18.

[0040] It is understandable that, to facilitate the flow of media and flow rate regulation in the pipeline, flow sensors, pumps, valves, etc., can be installed on the pipeline as needed. For example, an inlet pump 2, an inlet flow regulating valve 3, and a check valve 4 can be installed on the inlet pipeline 1; an internal circulation pump 20 can be installed on the internal circulation pipeline 21; a pretreatment outlet pump 12 can be installed on the first pipeline 13; a reaction zone outlet pump 23 can be installed on the second pipeline 22; and a drain pump 27 and a drain valve 28 can be installed on the outlet pipeline 26. Among these, a horizontal centrifugal pump (flow rate 0.4 m³ / h) can be selected as the inlet pump, and a magnetic pump (flow rate 1.0 m³ / h) can be selected as the internal circulation pump.

[0041] This embodiment also provides a wastewater denitrification treatment method, which uses the above-described system to treat wastewater. In a specific implementation, the method's flow is as follows: wastewater enters the reactor pretreatment zone via an influent pump, where suspended solids are removed before entering the coupling reaction zone; the MABR membrane module transfers oxygen to the biofilm through bubble-free aeration, achieving ammonia nitrogen nitrification to generate NO3. - The iron-carbon packing undergoes a micro-electrolysis reaction, providing electron donors for autotrophic denitrifying bacteria and converting NO3- into nitrogen. - It is reduced to N2; at the same time, the MABR membrane module and the iron-carbon packing work together to enhance the coupling of heterotrophic denitrification and autotrophic denitrification, so as to achieve efficient removal of total nitrogen; the treated wastewater enters the effluent buffer zone, and after sedimentation, it is discharged by the drainage pump. The water quality monitor monitors the effluent water quality in real time, and the controller dynamically adjusts the operating parameters according to the monitoring data.

[0042] To further illustrate the wastewater treatment effect of the system in this embodiment, two experimental examples are provided below.

[0043] Experimental Example 1 Influent water quality: taken from rural domestic sewage in Xinjiang (pretreated by septic tank), COD 80-150mg / L, ammonia nitrogen 25-40mg / L, total nitrogen 30-45mg / L, suspended solids 40-60mg / L, pH 7.0-8.0, water temperature 22-28℃.

[0044] Operation process: Wastewater is pumped to the pretreatment zone by the influent pump. Large particles are removed by the built-in screen (8mm gap). Then, it undergoes natural sedimentation (HRT 1.5h) in the pretreatment zone, with a suspended solids removal rate of 40%-50%. After pretreatment, the suspended solids content of the wastewater is ≤30mg / L, and it enters the coupling reaction zone.

[0045] Within the coupled reaction zone, the aeration rate is adjusted to 1.2 m³ / (m²·h), and air is supplied to the MABR membrane module through an aeration distributor. Oxygen permeates through the membrane fibers to the surface biofilm, maintaining a dissolved oxygen concentration of 1.5-2.5 mg / L on the membrane surface. In the aerobic zone, nitrifying bacteria convert ammonia nitrogen to nitrate (nitrification rate 0.3 kg / (m³·d)). A micro-electrolysis reaction occurs in the iron-carbon packing material, with Fe... 0 Hydrogen evolution through corrosion provides electron donors for autotrophic denitrifying bacteria, reducing nitrates to N2. During the reaction, the Fe²⁺ concentration is maintained at 0.8-1.5 mg / L, and the autotrophic denitrification rate is 0.25 kg / (m³・d). The circulation pump is activated, with an internal circulation ratio set to 3:1 to ensure uniform water mixing and enhance mass transfer efficiency. The controller dynamically adjusts the control parameters of each reaction zone based on water quality: when the influent ammonia nitrogen rises to 40 mg / L, the aeration rate is automatically increased to 1.5 m³ / (m²・h); when the pH drops to 6.8, it is fine-tuned to 7.2 using an alkali addition device (5% NaOH solution) to maintain a stable reaction environment.

[0046] After the coupling reaction, the wastewater enters the effluent buffer zone for solid-liquid separation (HRT3h). The settled sludge is partially returned through the sludge discharge port (return ratio 10%), and the remaining sludge is discharged periodically (moisture content 97%-98%). The treated wastewater is discharged through the effluent pump, and the effluent water quality is monitored in real time.

[0047] After 30 days of continuous operation, the test results were as follows: effluent COD: 35-48 mg / L (average 42 mg / L), removal rate 65%-70%; effluent ammonia nitrogen: 0.5-3.0 mg / L (average 1.8 mg / L), removal rate 93%-98%; effluent total nitrogen: 8-14 mg / L (average 11 mg / L), removal rate 80%-90%; operating energy consumption: 0.35 kW・h / m³ (lower than the traditional AO process of 0.55 kW・h / m³), no external carbon source added, operating cost 0.8 yuan / m³.

[0048] Experiment Example 2 In this example, the influent water quality is the effluent from a chemical plant's high ammonia nitrogen wastewater after anaerobic ammonia oxidation treatment, with COD 40-80 mg / L, ammonia nitrogen 5-15 mg / L, total nitrogen 20-30 mg / L, pH 7.5-8.5, and water temperature 28-32℃.

[0049] The system process parameters are as follows: the circulation ratio is increased to 4:1, the aeration rate is reduced to 0.8 m³ / (m²・h), the iron-carbon packing is replaced with an iron-carbon mass ratio of 3:1 (particle size 4 mm), and the HRT of the coupled reaction zone is extended to 10 h.

[0050] After 20 days of continuous operation, the total nitrogen in the effluent is stable at 5-12 mg / L (average 8 mg / L), with a removal rate of 65%-75%; the COD in the effluent is 25-45 mg / L, which meets the Class A standard of the "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants" (GB18918-2002) and can be reused as industrial circulating cooling water.

[0051] As demonstrated in Experiments 1 and 2, the system in this embodiment can significantly improve wastewater denitrification efficiency. Compared to traditional wastewater treatment processes, this system reduces energy consumption by over 30%, occupies 40% less land, and reduces operating costs by 25%-40%. The effluent quality meets Class A standards, and the total nitrogen removal rate is ≥90%. This system can treat 5-10 m³ / d of decentralized domestic sewage and high-ammonia-nitrogen wastewater, exhibits strong resistance to shock loads, and is suitable for complex operating conditions such as in remote areas of Xinjiang.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An integrated wastewater denitrification treatment system, characterized in that, include: Reactor, inlet pipe, outlet pipe, and controller; The reactor is divided into a pretreatment zone, a coupling reaction zone, and an effluent buffer zone from top to bottom; the outlet of the inlet pipe is connected to the pretreatment zone, and the inlet of the effluent pipe is connected to the effluent buffer zone; the pretreatment zone is connected to the coupling reaction zone through a first pipe. The coupling reaction zone is connected to the outlet buffer zone via a second pipeline; The coupling reaction zone includes multiple MABR membrane modules and multiple iron-carbon filler layers arranged in an alternating manner, wherein the first iron-carbon filler layer is located above the first MABR membrane module. A water quality monitor is installed on the outlet pipeline, and the controller is connected to the water quality monitor; the controller is used to adjust the operating parameters of the coupling reaction zone according to the water quality monitored by the water quality monitor.

2. The system according to claim 1, characterized in that, The water quality conditions include the effluent COD value, effluent ammonia nitrogen value, and effluent total nitrogen value; the second pipeline is equipped with a reaction zone effluent control valve; The step of adjusting the operating parameters of the coupled reaction zone based on the water quality monitored by the water quality monitor includes: adjusting the effluent control valve of the reaction zone to reduce the effluent flow rate of the second pipeline when at least one of the effluent COD value, the effluent ammonia nitrogen value and the effluent total nitrogen value is greater than the corresponding threshold.

3. The system according to claim 1, characterized in that, The pretreatment zone includes multiple layers of grilles, which are inclined downwards along the direction away from the water inlet pipe, and the ribs of adjacent layers of grilles are staggered.

4. The system according to claim 3, characterized in that, A water level sensor is installed in the pretreatment area, and a pretreatment outlet water control valve is installed on the first pipeline; the controller is connected to the water level sensor and the pretreatment outlet water control valve respectively. The controller is also configured to: open the pre-treatment water outlet control valve when the water level sensor detects that the liquid level in the pre-treatment zone has reached the preset upper limit of the liquid level; and close the pre-treatment water outlet control valve when the water level sensor detects that the liquid level in the pre-treatment zone has dropped to the preset lower limit of the liquid level.

5. The system according to claim 1, characterized in that, It also includes an acid-base dosing pump, the outlet of which is connected to the pretreatment zone; a pH meter is installed in the pretreatment zone; and the controller is connected to both the acid-base dosing pump and the pH meter. The controller is also configured to: when the pH value of the wastewater in the pretreatment zone detected by the pH meter is not within the preset acidity / alkalinity range, control the acid / alkalinity dosing pump to add reagents to the pretreatment zone so that the pH value of the wastewater is maintained within the preset acidity / alkalinity range.

6. The system according to claim 1, characterized in that, It also includes an aeration pump; the bottom of the MABR membrane module is provided with multiple aeration distributors, and the aeration pump is connected to the aeration distributors.

7. The system according to claim 6, characterized in that, The water quality information includes dissolved oxygen content; the controller is connected to the aeration pump. The controller is further configured to: determine whether the dissolved oxygen content is within a preset oxygen content range; increase the aeration rate of the aeration pump when the dissolved oxygen content is lower than the lower limit of the preset oxygen content range; and decrease the aeration rate of the aeration pump when the dissolved oxygen content is higher than the upper limit of the preset oxygen content range.

8. The system according to claim 1, characterized in that, The iron-carbon packing layer includes a removable packing box, and the reactor side wall is provided with an insertion port. The removable packing box is inserted into the reactor along the insertion port; the removable packing box is filled with iron-carbon packing. Preferably, the particle size of the iron-carbon filler is in the range of [3mm, 8mm]; the iron-carbon mass ratio of the iron-carbon filler is (1-3):

1.

9. The system according to claim 1, characterized in that, It also includes an internal circulation pipeline, the inlet and outlet of which are both connected to the sidewall of the coupling reaction zone; the inlet of the internal circulation pipeline is located below the multiple iron-carbon packing layers, and the outlet of the internal circulation pipeline is located above the multiple iron-carbon packing layers. Preferably, an internal circulation flow regulating valve is provided on the internal circulation pipeline; the controller is connected to the internal circulation flow regulating valve.

10. A wastewater denitrification treatment method, characterized in that, Wastewater is treated using the system described in any one of claims 1-9.

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