Double-phase mixing reinforced rotational flow aeration wastewater treatment method

Abstract

The invention discloses a double-phase mixing reinforced spiral-flow aeration wastewater treatment method. The method comprises the following steps: step 1, preparation at the early stage of treatment; step 2, mounting a spiral-flow aeration system; 3, system pilot run debugging; step 4, intelligent operation control; step 5, sludge anti-deposition guarantee; 6, monitoring the treatment effect in real time; step 7, maintaining the system; by adopting the combined design of the large-diameter double nozzles and the double-mushroom-head cutting device, compressed air is cut into tiny bubbles, and the gas-liquid contact area is increased; meanwhile, the spiral flow guide structure prolongs the retention time of bubbles in water, the oxygen transfer efficiency is greatly improved, and the problem that the oxygen utilization rate of a traditional aeration technology is low is solved. Precise intelligent control of dissolved oxygen is introduced, the aeration rate is dynamically adjusted according to the water quality change of inlet water, and energy waste caused by invalid operation of a fan is avoided.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a two-phase mixed enhanced swirl aeration wastewater treatment method. Background Technology

[0002] As a vital raw material industry for the national economy, the paper industry generates large amounts of highly polluting wastewater during its production process. This wastewater is characterized by high suspended solids content, poor biodegradability, high color, and complex organic composition, posing a serious threat to the ecological environment. With the deepening of ecological civilization construction, pulp and paper enterprises have placed higher demands on the efficiency, energy conservation, and stability of wastewater treatment processes.

[0003] Microbial treatment systems have become the mainstream technology for treating pulp and paper wastewater due to their advantages such as low operating costs and environmental friendliness. Aerobic aeration systems, as the core component of these systems, perform the dual functions of oxygenation and mixing: on the one hand, they transfer oxygen from the air into the mixed liquor to meet the respiratory needs of microorganisms in the activated sludge; on the other hand, they ensure sufficient contact between activated sludge, dissolved oxygen, and organic matter, while preventing sludge deposition. However, existing aeration technologies still have many shortcomings: Microporous aerators release tiny bubbles through the micropores of a rubber diaphragm. While they perform reasonably well in low-concentration domestic sewage, when applied to industrial wastewater, their fixed installation leads to easy clogging of the micropores, making maintenance difficult. After long-term operation, the bubbles become coarser, oxygen utilization decreases, operating resistance increases, and the lack of stirring function results in significant sludge deposition problems. Jet aerators rely on high-speed jetting of circulating water to entrain air. Although they serve a large area and are less prone to clogging, they require an additional circulating water pump, resulting in higher energy consumption. Furthermore, the nozzles are prone to scaling and clogging, affecting treatment efficiency.

[0004] While existing cyclone aeration technology has initially shown potential for high efficiency and low energy consumption, there is still room for improvement in its gas-liquid mixing effect. Specifically, the degree of bubble cutting and refinement is insufficient, the uniformity of sludge entrainment is poor, and there is a lack of intelligent control mechanism that dynamically matches water quality changes, resulting in insufficient oxygen utilization and limited energy-saving and carbon-reducing effects. Summary of the Invention

[0005] The purpose of this invention is to provide a two-phase mixed enhanced swirl aeration wastewater treatment method to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a two-phase mixed enhanced swirl aeration wastewater treatment method, comprising the following steps: Step 1: Pre-treatment preparation: Conduct a site survey of the aeration tank of the pulp and paper wastewater treatment plant to determine the effective tank volume, average tank depth, and influent flow rate parameters. Test the influent COD, suspended solids, ammonia nitrogen, total nitrogen, and pH value. Based on the tank parameters and water quality test results, select a suitable cyclone aerator. Step 2, Installation of the swirl aeration system: Install swirl aerators in the aeration tank at preset intervals and densities. The swirl aerators adopt a large-diameter double-nozzle air inlet structure and are equipped with double mushroom head cutting devices arranged vertically along the axial direction. Fix the swirl aerators to the aeration pipeline through connecting flanges and support the aeration pipeline with the lower bracket of the aeration pipeline. Step 3: System trial operation and debugging: Introduce compressed air into the aeration pipeline to test the air tightness; start the aeration blower, adjust the air volume to observe the bubble cutting effect, monitor the negative pressure entrainment state at the bottom of the aerator, and adjust the parameters to make the mixed liquid form a violent spiral mixing flow. Step 4: Intelligent Operation Control: Start the dissolved oxygen online monitoring equipment and the influent water quality online monitoring system. The intelligent control system will automatically adjust the aeration rate of the aeration blower based on the monitoring data. Step 5, Sludge Preventing Deposition: Utilize the negative pressure vortex formed at the bottom of the aerator to entrain the activated sludge from the bottom of the tank, mixing it with gas and liquid to form a three-phase spiral upward flow; monitor the sludge concentration in real time, and adjust the aeration volume or aeration frequency when abnormalities occur; Step 6: Real-time monitoring of treatment effect: Regularly test the COD, suspended solids, ammonia nitrogen and total nitrogen in the effluent, record the oxygen utilization rate and energy consumption parameters of the aeration system, and issue early warnings and take action when abnormalities occur; Step 7: System maintenance: Regularly clean the aerator's dual nozzles and dual mushroom heads, check the sealing of the aeration pipeline, and calibrate the intelligent monitoring equipment and control system.

[0007] Furthermore, the effective volume of the aeration tank in step one is 23850 m³. 3 The average pool depth is 9m, and the designed inflow rate is 20,000m³. 3 / d, influent COD concentration ≤1000mg / L.

[0008] Furthermore, in step two, the large-diameter dual nozzles are symmetrically arranged, with the air intake direction facing the dual mushroom heads. The spacing between the dual mushroom heads and the dual nozzles is matched to ensure that the compressed air fully collides and cuts with the dual mushroom heads.

[0009] Furthermore, the trial operation and debugging in step three requires confirmation through underwater observation equipment that the bubbles are fine and uniform, the mixture does not stratify, and a negative pressure vortex can be stably formed at the bottom of the aerator.

[0010] Furthermore, the intelligent control system in step four includes an online dissolved oxygen monitoring module, a water quality analysis module, and an aeration volume control module. The three modules interact in real time to achieve dynamic closed-loop control of the aeration volume.

[0011] Furthermore, the negative pressure vortex in step five is formed by the combined action of high-speed airflow jets inside the swirl aerator and the spiral guide component, creating a circulating flow around the aerator and covering the bottom of the aeration tank without any dead corners.

[0012] Furthermore, the effluent quality testing frequency in step six is ​​at least once a day, and the oxygen utilization rate and energy consumption parameters are monitored once an hour. The monitoring data is uploaded to the intelligent control system for archiving in real time.

[0013] Furthermore, the maintenance cycle for step seven is monthly routine maintenance and quarterly intelligent device calibration. After maintenance, a trial run and debugging should be conducted to confirm that the system is functioning normally.

[0014] Compared with the prior art, the beneficial effects of the present invention are: This invention employs a combination design of large-diameter dual nozzles and a dual mushroom-head cutting device to cut compressed air into microbubbles, increasing the gas-liquid contact area. Simultaneously, the spiral guide structure extends the residence time of the bubbles in the water, significantly improving oxygen transfer efficiency and solving the problem of low oxygen utilization in traditional aeration technologies. Precise intelligent control of dissolved oxygen is introduced, dynamically adjusting the aeration rate based on changes in influent water quality, avoiding energy waste caused by ineffective blower operation. Furthermore, the cyclone aerator eliminates the need for an additional circulating water pump, further reducing system energy consumption and achieving energy conservation and carbon reduction goals. The negative pressure vortex generated during aerator operation continuously entrains activated sludge from the bottom of the tank, thoroughly mixing it with the gas, preventing sludge deposition that leads to decreased treatment efficiency. The optimized design of the circulating flow ensures no dead zones for sedimentation, improving the metabolic efficiency of aerobic organisms. Attached Figure Description

[0015] Fig. 1 This is a flowchart of the method of the present invention; Fig. 2 This is a schematic diagram of the structure and installation of the present invention. Detailed Implementation

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all 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.

[0017] Please see Figs. 1-2This invention provides a two-phase mixed enhanced swirl aeration wastewater treatment method, comprising the following steps: Step 1: Preliminary Preparations Tank and Operating Condition Survey: A comprehensive survey of the existing aeration tanks in the pulp and paper wastewater treatment plant (prioritizing the fourth-phase aeration system) will be conducted to determine basic parameters such as the effective tank volume, average tank depth, inlet pipe layout, and effluent discharge requirements. The effective tank volume of the aeration tank is 23,850 m³. 3 The average pool depth is 9m, and the designed inflow rate is 20,000m³. 3 / d.

[0018] Comprehensive water quality testing: Collect influent water samples from the aeration tank and test core water quality indicators, including COD, suspended solids content, ammonia nitrogen, total nitrogen, pH value, and biodegradability. The influent COD concentration is ≤1000mg / L, providing a basis for the design of aeration system parameters.

[0019] Aerator selection and adaptation: Based on the tank parameters and water quality test results, select a vortex aerator with a large-diameter dual-nozzle air inlet structure and a dual mushroom head cutting device to ensure that the aerator's treatment capacity and service area match the existing aeration tank conditions and meet the oxygen transfer efficiency and sludge entrainment requirements.

[0020] Step 2: Installation of the swirl aeration system Installation location determination: Based on the depth and shape of the aeration tank, and combined with the results of fluid dynamics simulation, determine the installation spacing and layout density of the swirl aerators to ensure that the spiral upward flow formed by aeration can cover the entire effective reaction area of ​​the aeration tank without any aeration dead zones.

[0021] Aerator installation: The swirl aerator is precisely connected and fixed to the aeration pipeline through the connecting flange to ensure a good seal at the connection point; the aeration pipeline is supported and reinforced using the aeration pipe bracket to ensure that the aerator is stable and does not shake during operation, and to avoid the aeration effect being affected by vibration.

[0022] Structural assembly verification: Confirm that the large-diameter dual nozzles of the cyclone aerator are symmetrically arranged, and the air intake direction is precisely directed towards the internal dual mushroom heads; the dual mushroom heads are arranged parallel to each other vertically along the axis of the aerator body, and the spacing between them is adapted to the dual nozzles to ensure that the compressed air can fully collide and contact with the dual mushroom heads after being ejected; check the integrity of the spiral guide components inside the aerator to ensure that the airflow can form a stable spiral upward flow pattern.

[0023] Step 3: System Trial Run and Debugging Air tightness test: Close the inlet valve of the aeration tank, introduce compressed air into the aeration pipeline, maintain the pressure within the working pressure range, and check the sealing of the aeration pipeline, connecting flange and aerator body to ensure that there is no air leakage.

[0024] Airflow parameter adjustment: Start the aeration blower, gradually adjust the blower output air volume, observe the air output status of the cyclone aerator, and ensure that the airflow sprayed from the dual nozzles is uniform and stable; check the bubble cutting effect through underwater observation equipment to ensure that microbubbles are formed after the collision and cutting of the dual mushroom heads, and that the bubbles diffuse evenly in the water.

[0025] Negative pressure entrainment verification: Monitor the flow pattern changes in the bottom area of ​​the aerator to confirm that the negative pressure vortex formed by the high-speed jet of air can effectively entrain the simulated sludge (or the original activated sludge) at the bottom of the tank, so that the sludge enters the aerator body and mixes fully with the gas and liquid, without obvious sludge deposition.

[0026] Mixing effect optimization: Adjust the blower air volume and aeration frequency to make the mixed liquor in the aeration tank in a vigorous spiral mixing state, ensuring that the activated sludge, dissolved oxygen and organic matter are in full contact. By sampling and testing the uniformity of dissolved oxygen in the mixed liquor, the deviation of dissolved oxygen concentration in different areas of the tank is ensured to be within a reasonable range.

[0027] Step 4: Intelligent Operation Control Monitoring system startup: Start the dissolved oxygen online monitoring equipment, set up monitoring points in different areas of the aeration tank, and collect dissolved oxygen concentration data of the mixed liquor in real time; simultaneously connect to the influent water quality online monitoring system to obtain influent COD, ammonia nitrogen, total nitrogen and other indicators data in real time.

[0028] Intelligent control logic activation: The intelligent control system automatically calculates the optimal aeration parameters based on changes in influent water quality indicators and real-time dissolved oxygen monitoring data, combined with the oxygen demand model of aerobic microorganisms. It then dynamically adjusts the aeration volume by controlling the frequency of the aeration blower or the valve opening.

[0029] Optimized operating parameters: When the concentration of pollutants such as COD and ammonia nitrogen in the influent increases, the aeration rate is automatically increased to ensure that the dissolved oxygen concentration meets the metabolic needs of microorganisms; when the pollutant concentration decreases, the aeration rate is automatically reduced to avoid ineffective energy consumption of the blower and achieve energy saving and carbon reduction.

[0030] Step 5: Sludge Preventing Deposition Negative pressure entrainment enhancement: Utilizing the negative pressure vortex formed at the bottom of the cyclone aerator during operation, the activated sludge from the bottom of the tank is continuously entrained into the aerator body, where it is fully mixed with the refined microbubbles and wastewater under the action of the spiral guide component, forming a three-phase spiral upward flow state of gas, liquid and solid.

[0031] Sludge concentration dynamic monitoring: The intelligent control system monitors the changes in activated sludge concentration in the aeration tank in real time. When the sludge concentration increases locally or when a sedimentation trend is detected at the bottom of the tank, the aeration volume or aeration frequency of the aerators in the corresponding area is automatically adjusted to enhance the mixing effect.

[0032] Maintaining Circulating Flow: By optimizing the density and installation location of aerators, the circulating flow patterns formed by each aerator are superimposed, covering the entire bottom area of ​​the aeration tank, ensuring no dead spots for sludge deposition, and improving the degradation efficiency of pollutants by aerobic organisms.

[0033] Step Six: Real-time Monitoring of Treatment Results Effluent water quality testing: Collect effluent water samples from the aeration tank at regular intervals every day to test key indicators such as COD, suspended solids, ammonia nitrogen, and total nitrogen, evaluate the pollutant removal effect, and ensure that the effluent COD concentration is below 100mg / L and the COD removal rate is above 80%.

[0034] System operation parameter monitoring: Record parameters such as oxygen utilization rate, blower energy consumption, and aeration volume of the aeration system once per hour to ensure that the oxygen utilization rate reaches more than 20% and the electricity consumption per ton of water is controlled within 4.3 kWh / t.

[0035] Anomaly warning and handling: When the effluent water quality index is detected to exceed the standard or the system operating parameters are abnormal, the intelligent control system will immediately issue an early warning signal and automatically adjust the operating parameters; if the adjustment still fails to restore normal operation, it will remind staff to conduct manual investigation and handling.

[0036] Step 7: System Maintenance Aerator maintenance: Regularly shut down the aeration blower monthly, drain some of the sewage from the aeration tank, inspect the double nozzles and double mushroom heads of the cyclone aerator, and clean the attached dirt and blockages to ensure smooth air intake and effective bubble cutting.

[0037] Piping and equipment maintenance: Inspect the corrosion of aeration pipelines and the sealing of connecting flanges, and replace aged seals in a timely manner; perform routine maintenance on aeration blowers, including changing lubricating oil and cleaning filters.

[0038] Intelligent system calibration: The dissolved oxygen online monitoring sensor and water quality analysis module are calibrated quarterly to ensure the accuracy of monitoring data; the controllers and actuators of the intelligent control system are functionally tested to ensure the effective execution of control commands.

[0039] Example: This embodiment uses a wastewater treatment project in the fourth phase of a pulp and paper mill as an example. The effective volume of the aeration tank in this project is 23,850 m³. 3 The average pool depth is 9m, and the designed inflow rate is 20,000m³. 3 / d, with an influent COD concentration ≤1000mg / L, the wastewater is treated using the two-phase mixing enhanced vortex aeration wastewater treatment method of the present invention.

[0040] Step 1: Preliminary Preparations Tank Inspection: On-site measurements were conducted on the fourth-phase aeration tank of the wastewater treatment plant, confirming an effective tank volume of 23,850 m³.3 The average pool depth is 9m. The inlet pipe is located on the lower part of one side of the pool, and the outlet pipe is located on the upper part of the other side of the pool. The pool has a rectangular structure with no obvious structural obstacles.

[0041] Water quality testing: Influent water samples were collected for three consecutive days and tested by a third-party testing agency. The results showed that the average COD concentration of the influent was 850 mg / L, the suspended solids content was 320 mg / L, the ammonia nitrogen concentration was 45 mg / L, the total nitrogen concentration was 60 mg / L, the pH value was 7.2, and the biodegradability (BOD5 / COD) was 0.35, which met the typical water quality characteristics of pulp and paper wastewater.

[0042] Aerator Selection: Based on the tank parameters and water quality test results, the XL-200 vortex aerator was selected. This aerator is equipped with large-diameter dual nozzles (50mm diameter) and a dual mushroom head cutting device, with a single unit serving an area of ​​8-10m². 2 The oxygen transfer efficiency is ≥20%, which is suitable for the working conditions of this project.

[0043] Step 2: Installation of the swirl aeration system Installation location design: Based on the size of the aeration tank and the service area of ​​the aerators, the installation spacing of the aerators is determined to be 3m, and they are evenly distributed along the length of the tank, with a total of 265 units installed to ensure that there are no dead corners in aeration coverage; the installation height is 1.2m from the bottom of the tank, in a suitable area of ​​tank depth, to ensure negative pressure suction effect and mixed flow coverage.

[0044] Aerator installation: First, lay the aeration pipeline along the length of the tank and fix it to the pre-set base at the bottom of the tank using the aeration pipe support bracket. The support bracket spacing is 5m to ensure the pipeline is horizontal and stable. Then, connect the swirl aerator to the aeration pipeline through the connecting flange. Install a sealing gasket at each connecting flange and tighten it with bolts to ensure airtightness. After installation, manually check whether the aerator is stable and has no looseness.

[0045] Structural inspection: Check each aerator to see if the dual nozzles are symmetrical and if the air intake channel is unobstructed; check if the dual mushroom heads are arranged parallel to each other along the axis and the distance between them and the dual nozzles is 80mm to ensure that the compressed air can accurately hit the dual mushroom heads after being sprayed out; check if the spiral guide vanes inside the aerator are intact and free from deformation or breakage.

[0046] Step 3: System Trial Run and Debugging Air tightness test: Close the inlet and outlet valves of the aeration tank, introduce 0.4MPa compressed air into the aeration pipeline, maintain the pressure for 30 minutes, apply soapy water to the aeration pipeline interface, connecting flange and aerator body, observe that no bubbles are generated, and confirm that the air tightness is qualified.

[0047] Airflow parameter adjustment: Start the aeration blower, adjust the blower frequency to 30Hz, and set the output air volume to 50m³ / h. 3 / min, it was observed that the vortex aerator sprayed a uniform airflow from the two nozzles, which formed tiny bubbles with a diameter of 1-3mm after being cut by the double mushroom heads. The bubbles rose slowly in the water and spread over a wide range.

[0048] Negative pressure entrainment verification: Clean water was injected into the aeration tank and simulated sludge (concentration of 3000 mg / L) was added. The aeration system was started and ran for 30 minutes. Under the observation of the underwater camera, a clear negative pressure vortex was formed at the bottom of the aerator. The simulated sludge was continuously entrained into the aerator body and mixed with the air bubbles and clean water to form a uniform three-phase flow. There was no sludge deposition at the bottom of the tank.

[0049] Optimize mixing effect: Gradually adjust the fan frequency to 40Hz and increase the air volume to 70m³ / h. 3 / min, at which point the mixed liquid in the aeration tank forms a violent spiral upward flow. By placing dissolved oxygen sensors at different positions in the tank (front, middle, back, top, middle, bottom), the detection results show that the dissolved oxygen concentration is between 2.0-2.5mg / L, with a deviation of ≤0.3mg / L, indicating good mixing uniformity.

[0050] Step 4: Intelligent Operation Control Monitoring system startup: Three dissolved oxygen online monitoring sensors are installed at the front, middle and rear ends of the aeration tank, and online monitoring instruments for COD, ammonia nitrogen and total nitrogen are installed on the inlet pipeline. All monitoring equipment is connected to the intelligent control system, and the data sampling frequency is 1 time / minute.

[0051] Intelligent control logic activation: The suitable dissolved oxygen concentration range for aerobic microorganisms is set at 1.8-2.5 mg / L. The intelligent control system has a built-in oxygen demand model. When the influent COD concentration rises to 900 mg / L, the system automatically calculates the increase in oxygen demand, adjusts the blower frequency to 42 Hz, and increases the aeration rate to 75 m³ / h. 3 The dissolved oxygen concentration was maintained at 2.3 mg / L / min; when the influent COD concentration dropped to 700 mg / L, the blower frequency automatically decreased to 28 Hz and the aeration rate decreased to 45 m³ / min. 3 / min, the dissolved oxygen concentration remained stable at 2.0 mg / L.

[0052] Operating parameter optimization: During the trial operation, the system automatically adjusted the aeration rate according to changes in water quality. The average blower operating frequency was 35Hz, and the average aeration rate was 60m³ / h. 3 / min, avoiding the energy waste of the traditional fixed aeration mode.

[0053] Step 5: Sludge Preventing Deposition Enhanced negative pressure suction: When the aeration system is running normally, the negative pressure vortex formed at the bottom of the swirl aerator has a flow velocity of 0.8 m / s, which can effectively suction the activated sludge at the bottom of the tank. After the sludge is sucked into the aerator body, it is fully mixed with the microbubbles under the action of the spiral guide blades, and the residence time is extended to 8 seconds, which greatly improves the contact efficiency between microorganisms and pollutants.

[0054] Dynamic monitoring of sludge concentration: The intelligent control system monitors the concentration of activated sludge in the tank in real time. The control range is set to 2500-4000 mg / L. When the sludge concentration at the bottom of the rear end of the tank rises to 4200 mg / L, the system automatically increases the frequency of the blowers of 10 aerators in that area by 2 Hz to enhance the stirring effect. After 1 hour, the sludge concentration drops to 3800 mg / L and returns to the normal range.

[0055] Circulating flow state maintenance: Through the reasonable layout of aerators, the circulating flow states formed by each aerator are superimposed to form a uniform flow field at the bottom of the tank with a flow velocity ≥0.3m / s, ensuring that there are no dead corners for sludge deposition at the bottom of the entire tank, and that the activated sludge is always in a suspended mixed state.

[0056] Step Six: Real-time Monitoring of Treatment Results Effluent water quality testing: During system operation, effluent water samples were collected twice daily, at 9:00 AM and 3:00 PM. The test results showed that the average COD concentration was 85 mg / L, the average COD removal rate was 89%, the average suspended solids content was 15 mg / L, the average ammonia nitrogen concentration was 5 mg / L, and the average total nitrogen concentration was 12 mg / L. All indicators met the direct discharge requirements of the "Water Pollutant Discharge Standard for Pulp and Paper Industry" (GB3544-2018).

[0057] System operating parameter monitoring: Operating data is recorded once per hour. The average oxygen utilization rate of the aeration system is 22%, and the average electricity consumption per ton of water is 4.1 kWh / t, which is 0.4 kWh / t lower than the original microporous aeration system, showing significant energy-saving effect.

[0058] Anomaly Warning and Handling: On the 15th day of trial operation, the influent COD concentration suddenly rose to 1100 mg / L. The intelligent control system immediately issued an early warning signal and automatically increased the blower frequency to 45 Hz and the aeration rate to 80 m³ / L. 3 The COD concentration in the effluent stabilized at 98 mg / L after 2 hours, with no exceedance of the standard.

[0059] Step 7: System Maintenance Aerator maintenance: After one month of operation, turn off the aeration blower, drain 1 / 3 of the water in the tank, and have staff enter the tank to clean the double nozzles and double mushroom heads of each aerator, removing any attached sludge and scale, and ensuring that the air intake channel is unobstructed; after cleaning, check the bubble cutting effect and confirm that there are no abnormalities.

[0060] Piping and equipment maintenance: Inspect the aeration pipeline for obvious corrosion, ensure the connecting flanges are well sealed and there is no air leakage; maintain the aeration blower, replace the lubricating oil, clean the air filter, and ensure stable operation of the blower.

[0061] Intelligent system calibration: After 3 months of operation, a professional organization was commissioned to calibrate the dissolved oxygen sensor and COD online monitor. The error of the calibrated monitoring data was ≤±5%. Functional testing was conducted on the controller of the intelligent control system to ensure that the control commands were responded to in a timely manner and executed accurately.

[0062] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for treating wastewater by two-phase mixed enhanced swirl aeration, characterized in that: Includes the following steps: Step 1: Pre-treatment preparation: Conduct a site survey of the aeration tank of the pulp and paper wastewater treatment plant to determine the effective tank volume, average tank depth, and influent flow rate parameters. Test the influent COD, suspended solids, ammonia nitrogen, total nitrogen, and pH value. Based on the tank parameters and water quality test results, select a suitable cyclone aerator. Step 2, Installation of the swirl aeration system: Install swirl aerators in the aeration tank at preset intervals and densities. The swirl aerators adopt a large-diameter double-nozzle air inlet structure and are equipped with double mushroom head cutting devices arranged vertically along the axial direction. Fix the swirl aerators to the aeration pipeline through connecting flanges and support the aeration pipeline with the lower bracket of the aeration pipeline. Step 3: System trial operation and debugging: Introduce compressed air into the aeration pipeline to test the air tightness; start the aeration blower, adjust the air volume to observe the bubble cutting effect, monitor the negative pressure entrainment state at the bottom of the aerator, and adjust the parameters to make the mixed liquid form a violent spiral mixing flow. Step 4: Intelligent Operation Control: Start the dissolved oxygen online monitoring equipment and the influent water quality online monitoring system. The intelligent control system will automatically adjust the aeration rate of the aeration blower based on the monitoring data. Step 5, Sludge Preventing Deposition: Utilize the negative pressure vortex formed at the bottom of the aerator to entrain the activated sludge from the bottom of the tank, mixing it with gas and liquid to form a three-phase spiral upward flow; monitor the sludge concentration in real time, and adjust the aeration volume or aeration frequency when abnormalities occur; Step 6: Real-time monitoring of treatment effect: Regularly test the COD, suspended solids, ammonia nitrogen and total nitrogen in the effluent, record the oxygen utilization rate and energy consumption parameters of the aeration system, and issue early warnings and take action when abnormalities occur; Step 7: System maintenance: Regularly clean the aerator's dual nozzles and dual mushroom heads, check the sealing of the aeration pipeline, and calibrate the intelligent monitoring equipment and control system.

2. The method for treating wastewater by two-phase mixed enhanced swirl aeration according to claim 1, characterized in that: The effective volume of the aeration tank in step one is 23850 m³. 3 The average pool depth is 9m, and the designed inflow rate is 20,000m³. 3 / d, influent COD concentration ≤1000mg / L.

3. The method for treating wastewater by two-phase mixed enhanced swirl aeration according to claim 1, characterized in that: In step two, the large-diameter dual nozzles are symmetrically arranged, with the air intake direction facing the dual mushroom heads. The spacing between the dual mushroom heads and the dual nozzles is matched to ensure that the compressed air fully collides and cuts with the dual mushroom heads.

4. The method for treating wastewater by two-phase mixed enhanced swirl aeration according to claim 1, characterized in that: The trial operation and debugging in step three requires confirmation through underwater observation equipment that the bubbles are fine and uniform, the mixture does not stratify, and a negative pressure vortex can be stably formed at the bottom of the aerator.

5. The method for treating wastewater by two-phase mixed enhanced swirl aeration according to claim 1, characterized in that: The intelligent control system in step four includes an online dissolved oxygen monitoring module, a water quality analysis module, and an aeration volume control module. The three modules interact in real time to achieve dynamic closed-loop control of the aeration volume.

6. The method for treating wastewater by two-phase mixed enhanced swirl aeration according to claim 1, characterized in that: The negative pressure vortex in step five is formed by the high-speed jet of airflow inside the swirl aerator and the combined action of the spiral guide component, forming a circulating flow around the aerator and covering the bottom of the aeration tank without dead corners.

7. The method for treating wastewater by two-phase mixed enhanced swirl aeration according to claim 1, characterized in that: The effluent quality testing frequency in step six is ​​at least once a day, and the oxygen utilization rate and energy consumption parameters are monitored once an hour. The monitoring data is uploaded to the intelligent control system for archiving in real time.

8. The method for treating wastewater by two-phase mixed enhanced swirl aeration according to claim 1, characterized in that: The maintenance cycle for step seven is monthly routine maintenance and quarterly intelligent device calibration. After maintenance, a trial run and debugging should be conducted to confirm that the system is functioning normally.

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