A sewage treatment system based on powder activated carbon adsorption

Abstract

This utility model relates to a wastewater treatment system based on powdered activated carbon adsorption, belonging to the field of wastewater treatment technology. It includes a primary mixing reactor, a primary aeration tank, a secondary mixing reactor, a secondary aeration tank, and a sedimentation tank connected in series. Both the primary and secondary mixing reactors are connected to powdered activated carbon dosing devices. Each primary and secondary aeration tank has multiple guide walls dividing it into multiple aeration and mixing zones. Each aeration and mixing zone also has a siphon-type mixing and stirring device and multiple suspended porous carrier packing materials. The bottom of the sedimentation tank is connected to a sludge return device. This utility model improves the utilization rate of powdered activated carbon, reduces the amount of powdered activated carbon added, and lowers operating costs. Through the combined effects of aeration and stirring, the siphon-type mixing and stirring device, and sludge return, it maximizes the contact time between activated carbon and wastewater / sludge, thereby improving the adsorption and degradation efficiency of activated carbon.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, specifically to a wastewater treatment system based on powdered activated carbon adsorption. Background Technology

[0002] Traditional activated sludge processes have low efficiency in removing recalcitrant organic matter and are susceptible to shocks from toxic substances. Powdered activated carbon (PACT) methods suffer from high sludge production, difficulties in separating activated carbon from sludge, and high operating costs. The PACT process, however, improves pollutant removal rates through activated carbon adsorption and synergistic microbial degradation. Most existing processes involve directly adding activated carbon to the tank without sufficient contact between the activated carbon and wastewater, resulting in poor synergy between activated carbon and sludge, low activated carbon efficiency, and failure to maximize its effectiveness. Utility Model Content

[0003] Therefore, it is necessary to provide a wastewater treatment system based on powdered activated carbon adsorption to address the problems of existing technologies.

[0004] To solve the problems of the existing technology, the technical solution adopted by this utility model is as follows:

[0005] A wastewater treatment system based on powdered activated carbon adsorption includes a primary mixing reaction tank, a primary aeration tank, a secondary mixing reaction tank, a secondary aeration tank, and a sedimentation tank connected in series. The primary mixing reaction tank is connected to an inlet pipe, and the sedimentation tank is connected to an outlet pipe. Both the primary and secondary mixing reaction tanks are connected to powdered activated carbon dosing devices. Both the primary and secondary aeration tanks are equipped with multiple guide walls that divide them into multiple aeration and mixing zones. The guide walls have staggered guide ports at their upper and lower parts. Each aeration and mixing zone is equipped with a microporous aerator at its bottom. Each aeration and mixing zone is also equipped with a siphon-type mixing and stirring device and multiple suspended porous carrier packing materials. The bottom of the sedimentation tank is connected to a sludge return device, which is connected to both the primary and secondary mixing reaction tanks.

[0006] As a preferred option, each guide port is fixed with a barrier net to prevent the suspended porous carrier packing from flowing to other aeration mixing areas and causing uneven distribution of the suspended porous carrier packing.

[0007] As a preferred embodiment, the siphon-type mixing device includes multiple vertical mixing pipes arranged in each aeration mixing zone. Each mixing pipe has an air distribution ring pipe, and multiple jet pipes are evenly fixed to the top of the air distribution ring pipe. The air distribution ring pipe is connected to an air guide pipe, and the other end of each air guide pipe is connected to an air delivery pipe. The air delivery pipe is connected to a blower. By spraying air upwards through the jet pipes, the liquid inside the mixing pipe can be driven to flow upwards, thereby generating a siphon effect. This allows the liquid to enter from the bottom of the mixing pipe and exit from the top, increasing the mixing effect. Furthermore, the air distribution ring pipe ensures even air distribution, further enhancing the mixing effect.

[0008] As a preferred embodiment, each mixing tube has a downwardly convex hemispherical baffle fixed at its bottom to prevent the suspended porous carrier packing from entering the mixing tube. Furthermore, the downwardly convex hemispherical structure of the baffle prevents the suspended porous carrier packing from clogging the baffle.

[0009] As a preferred option, both the primary and secondary mixing reaction tanks are equipped with agitators, allowing the influent, sludge, and added powdered activated carbon to be mixed.

[0010] As a preferred embodiment, the powdered activated carbon feeding device includes a powdered activated carbon storage tank, which is connected to a feeding pump. The feeding pump is connected to a primary mixing reaction tank and a secondary mixing reaction tank via feeding pipes, enabling the feeding of powdered activated carbon.

[0011] As a preferred embodiment, the sludge return device includes a sludge pump connected to the bottom of the sedimentation tank, and the outlet of the sludge pump is connected to a return pipe and a conveying pipe. The return pipe is connected to the primary mixing reaction tank, which can return and convey the sludge.

[0012] As a preferred configuration, flow meters are installed on the inlet pipe, feed pipe, and return pipe, each connected to a controller. Electric valves are also installed on the feed pipe, delivery pipe, and return pipe. A sludge level gauge is installed on the sedimentation tank. Online COD analyzers, temperature sensors, and ORP analyzers are installed on both the primary and secondary mixing reaction tanks. Online dissolved oxygen analyzers, pH analyzers, and MLSS analyzers are installed on both the primary and secondary aeration tanks. All these components—including the online COD analyzer, temperature sensor, ORP analyzer, dissolved oxygen analyzer, pH analyzer, MLSS analyzer, electric valves, feed pump, sludge pump, and sludge level gauge—are connected to the controller. This configuration enables intelligent control and dynamic balance control.

[0013] The advantages of this utility model compared with the prior art are:

[0014] The addition of guide walls in the primary and secondary aeration tanks reduces dead corners and maximizes the residence time of powdered activated carbon, thereby improving the utilization rate of powdered activated carbon, reducing the amount of powdered activated carbon added, and lowering operating costs. Through the combined effects of aeration and stirring, siphon mixing and stirring devices, and sludge return, the contact time between activated carbon and sewage and sludge is maximized, thereby improving the adsorption and degradation efficiency of activated carbon. Attached Figure Description

[0015] Figure 1 This is a system flowchart of this utility model;

[0016] Figure 2 This is a schematic diagram of the structure of a primary aeration tank;

[0017] Figure 3This is a schematic diagram of the mixing tube structure;

[0018] Figure 4 yes Figure 3 A schematic diagram of the top structure;

[0019] Figure 5 This is a schematic diagram of the intelligent control interlocking of this utility model;

[0020] The numbers on the map are:

[0021] 1. Primary mixing reactor; 2. Primary aeration tank; 3. Secondary mixing reactor; 4. Secondary aeration tank; 5. Sedimentation tank; 6. Sludge pump; 7. Effluent pipe; 8. Microporous aerator; 9. Suspended porous carrier packing; 10. Mixing pipe; 11. Blower; 12. Feed pump; 13. Agitator; 14. Air guide pipe; 15. Barrier net; 16. Baffle net; 17. Guide wall; 18. Jet nozzle; 19. Air distribution ring pipe; 20. Return pipe; 21. Sludge level gauge; 22. Online pH analyzer; 23. Online MLSS analyzer; 24. Online COD analyzer; 25. Online dissolved oxygen analyzer; 26. Temperature sensor; 27. Online ORP analyzer; 28. Controller; 29. ​​Flow meter. Detailed Implementation

[0022] To further understand the features, technical means, and specific objectives and functions achieved by this utility model, the following detailed description of this utility model is provided in conjunction with the accompanying drawings and specific embodiments.

[0023] Example 1, Reference Figures 1 to 5 A wastewater treatment system based on powdered activated carbon adsorption includes a primary mixing reaction tank 1, a primary aeration tank 2, a secondary mixing reaction tank 3, a secondary aeration tank 4, and a sedimentation tank 5 connected in series. The primary mixing reaction tank 1 is connected to an inlet pipe, and the sedimentation tank 5 is connected to an outlet pipe 7. Both the primary mixing reaction tank 1 and the secondary mixing reaction tank 3 are connected to powdered activated carbon dosing devices. Both the primary aeration tank 2 and the secondary aeration tank 4 are equipped with multiple guide walls 17 that divide them into multiple aeration and mixing zones. The multiple guide walls 17 are staggered with guide ports at the top and bottom. Each aeration and mixing zone is equipped with a microporous aerator 8 at the bottom. Each aeration and mixing zone is also equipped with a siphon-type mixing and stirring device and multiple suspended porous carrier packing materials 9. The bottom of the sedimentation tank 5 is connected to a sludge return device, which is connected to the primary mixing reaction tank 1 and the secondary mixing reaction tank 3.

[0024] During operation, after pretreatment, wastewater enters the primary mixing reactor 1 through the inlet pipe, where it mixes with returned sludge and powdered activated carbon added by the powdered activated carbon dosing device. This process adsorbs organic pollutants in the wastewater, thereby reducing the concentration of pollutants. The wastewater then flows by gravity into the primary aeration tank 2, where it is thoroughly mixed by the combined effects of microporous aerators 8, siphon mixing devices, and guide walls 17. The wastewater, sludge, and activated carbon are gradually degraded by microorganisms. The mixture then enters the secondary mixing reactor 3, where it mixes with newly added powdered activated carbon. It then enters the secondary aeration tank 4, where it is again thoroughly mixed by the combined effects of microporous aerators 8, siphon mixing devices, and guide walls 17. The mixture is further degraded by microorganisms. Finally, it enters the sedimentation tank 5 for sedimentation. A portion of the settled sludge is returned to the primary mixing reactor 1 via a sludge return device, while the upper layer of wastewater is discharged through the outlet pipe 7.

[0025] In Example 2, based on Example 1, a barrier mesh 15 is fixed inside each flow guide. The mesh opening diameter of the barrier mesh 15 is smaller than the size of the suspended porous carrier packing 9.

[0026] The siphon-type mixing device includes multiple vertical mixing pipes 10 arranged in each aeration mixing zone. Each mixing pipe 10 has an air distribution ring pipe 19. Multiple jet pipes 18 are evenly fixed to the top of the air distribution ring pipe 19. The air distribution ring pipe 19 is connected to an air guide pipe 14, and the other end of each air guide pipe 14 is connected to an air delivery pipe, which is connected to a blower 11. Gas discharged from the blower 11 enters the air guide pipe 14 through the air delivery pipe, and then, after being distributed through the air distribution ring pipe 19, is ejected upwards from the jet pipes 18. This causes the liquid inside the mixing pipe 10 to flow upwards, creating a siphon effect. The liquid enters from the bottom of the mixing pipe 10 and exits from the top, increasing the mixing effect. Furthermore, the air distribution ring pipe 19 ensures even air distribution, further enhancing the mixing effect.

[0027] Each mixing pipe 10 has a downwardly convex hemispherical baffle 16 fixed at its bottom. Part of the sludge is returned to the primary mixing reaction tank 1, and the remaining sludge enters the sludge treatment system through the conveying pipe.

[0028] Both the primary mixing tank 1 and the secondary mixing tank 3 are equipped with a stirrer 13. Wastewater and powdered activated carbon are in full contact in the mixing tank for 10-30 minutes. The particle size of the powdered activated carbon is ≤100μm.

[0029] The powdered activated carbon dosing device includes a powdered activated carbon storage tank, which is connected to a feeding pump 12. The feeding pump 12 is connected to the primary mixing reaction tank 1 and the secondary mixing reaction tank 3 via feeding pipes. The powdered activated carbon dosage is controlled at 50-500 mg / L (dynamically adjusted according to the influent water quality). Wood-based activated carbon with a particle size of 200-400 mesh is preferred. Suspended porous carrier packing 9 is installed in the primary aeration tank 2 and the secondary aeration tank 4. The suspended porous carrier packing 9 provides a comfortable biological bed for microorganisms. A large number of microorganisms attach to the suspended porous carrier packing 9, and the activated sludge, powdered activated carbon, and suspended porous carrier packing 9 frequently collide and contact with each other, greatly increasing the contact area and creating favorable conditions for microorganisms to rapidly remove pollutants from wastewater, thereby improving wastewater removal efficiency.

[0030] A multi-point dosing method for powdered activated carbon is adopted. During the operation of this multi-stage series process, there are significant concentration differences in wastewater at different process stages. The upstream stage is a high-load zone, while the downstream stage becomes a fine treatment zone, thus improving pollutant removal capacity. Furthermore, multi-point dosing maximizes reagent utilization and reduces operating costs.

[0031] The sludge return system includes a sludge pump 6 connected to the bottom of sedimentation tank 5. The outlet of sludge pump 6 is connected to a return pipe 20 and a delivery pipe. The return pipe 20 is connected to the primary mixing reactor 1. The sludge settling time (SRT) is extended to 10-30 days to improve the degradation of adsorbed organic matter by microorganisms. The mixed liquor concentration (MLSS) is maintained at 3000-8000 mg / L.

[0032] Flow meters 29 are installed on the inlet pipe, feed pipe, and return pipe 20. The flow meters 29 are connected to the controller 28. Electric valves are installed on the feed pipe, conveying pipe, and return pipe 20. A sludge level gauge 21 is installed on the sedimentation tank 5. An online COD analyzer 24, a temperature sensor 26, and an online ORP analyzer 27 are installed on the primary mixing reaction tank 1 and the secondary mixing reaction tank 3. An online dissolved oxygen analyzer 25, an online pH analyzer 22, and an online MLSS analyzer 23 are installed on the primary aeration tank 2 and the secondary aeration tank 4. The online COD analyzer 24, temperature sensor 26, ORP analyzer 27, dissolved oxygen analyzer 25, pH analyzer 22, MLSS analyzer 23, electric valves, feed pump 12, sludge pump 6, and sludge level gauge 21 are all connected to the controller 28. All instrument data is uploaded to the DCS controller 28. By analyzing data such as tank temperature, COD, sludge concentration, and sludge level, the dosage of powdered activated carbon, sludge return flow rate, and sludge discharge rate are determined. This reduces unnecessary waste of powdered activated carbon, thereby lowering operating costs.

[0033] After pretreatment, wastewater enters the primary mixing reactor 1. Powdered activated carbon is added to the primary mixing reactor 1 via a dosing device. Sludge from sedimentation tank 5 is returned to the primary mixing reactor 1 via a sludge return device. The various materials in the reactor are rapidly mixed by agitator 13. During the process of full contact between the powdered activated carbon and the wastewater, organic pollutants in the wastewater are rapidly adsorbed, thereby reducing the concentration of pollutants. Especially when treating recalcitrant or toxic wastewater, the reduced pollutant concentration mitigates the impact of toxicity on aerobic microorganisms, thus improving the adaptability and removal efficiency of the biochemical microorganisms. The wastewater flows by gravity to the primary aeration tank 2. Through the combined effects of aeration, mixing, and flow guidance by the guide wall 17 in the primary aeration tank 2, the wastewater, sludge, and activated carbon are thoroughly mixed. As the wastewater flows to the downstream end, the pollutant concentration gradually decreases, and the recalcitrant or toxic pollutants adsorbed by the powdered activated carbon in the early stages are gradually released and gradually degraded by microorganisms. Through their combined action, the load at the front end of the process is reduced, and the load at the downstream end is increased, thereby improving the overall volumetric load and removal efficiency. Wastewater flows by gravity to the secondary mixing reactor 3. In the secondary mixing reactor 3, activated carbon is added via a powdered activated carbon dosing device, improving the utilization rate of the powdered activated carbon through multi-point dosing. The newly added powdered activated carbon and wastewater in the reactor are rapidly mixed and reacted by agitator 13. The wastewater then flows by gravity to the secondary aeration tank 4. In the secondary aeration tank 4, the combined effects of aeration, mixing, and flow guidance by the guide wall 17 ensure thorough mixing and reaction of the wastewater, sludge, and activated carbon. Finally, the wastewater flows by gravity to the sedimentation tank 5, where gravity separates the sludge from the water. The supernatant flows by gravity to the effluent pipe 7 for subsequent treatment or discharge after meeting standards. Part of the bottom sludge is returned to the primary mixing reactor 1 via a sludge return device to replenish lost sludge and powdered activated carbon. The remaining sludge in the sedimentation tank 5 is discharged to the sludge treatment unit for further treatment via a conveying pipe.

[0034] The above embodiments only illustrate one or more implementations of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A sewage treatment system based on powder activated carbon adsorption, comprising a first-stage mixing reaction tank (1), a first-stage aeration tank (2), a second-stage mixing reaction tank (3), a second-stage aeration tank (4) and a sedimentation tank (5) connected in series, the first-stage mixing reaction tank (1) being connected to a water inlet pipe, and the sedimentation tank (5) being connected to a water outlet pipe (7), characterized in that: Both the primary mixing reactor (1) and the secondary mixing reactor (3) are connected to a powdered activated carbon dosing device. Both the primary aeration tank (2) and the secondary aeration tank (4) are equipped with multiple guide walls (17) that divide them into multiple aeration mixing zones. The multiple guide walls (17) are staggered at the top and bottom. Each aeration mixing zone is equipped with a microporous aerator (8) at the bottom. Each aeration mixing zone is also equipped with a siphon mixing and stirring device and multiple suspended porous carrier packings (9). The bottom of the sedimentation tank (5) is connected to a sludge return device, which is connected to the primary mixing reactor (1) and the secondary mixing reactor (3). ​ 2. The powdered activated carbon adsorption-based sewage treatment system according to claim 1, characterized in that, Each flow inlet is fitted with a barrier net (15).

3. The powdered activated carbon adsorption-based sewage treatment system according to claim 1, characterized in that, The siphon mixing device includes multiple vertical mixing pipes (10) set in each aeration mixing area. An air distribution ring pipe (19) is provided in the mixing pipe (10). Multiple jet pipes (18) are uniformly fixed at the top of the air distribution ring pipe (19). The air distribution ring pipe (19) is connected to an air guide pipe (14). The other end of the multiple air guide pipes (14) is connected to an air delivery pipe. The air delivery pipe is connected to a blower (11).

4. A wastewater treatment system based on powdered activated carbon adsorption according to claim 3, characterized in that, Each mixing tube (10) has a convex hemispherical baffle (16) fixed to its bottom.

5. A wastewater treatment system based on powdered activated carbon adsorption according to claim 1, characterized in that, Both the primary mixing reaction tank (1) and the secondary mixing reaction tank (3) are equipped with a stirrer (13).

6. A wastewater treatment system based on powdered activated carbon adsorption according to claim 1, characterized in that, The powdered activated carbon dosing device includes a powdered activated carbon storage tank, which is connected to a feeding pump (12). The feeding pump (12) is connected to a primary mixing reaction tank (1) and a secondary mixing reaction tank (3) through a feeding pipe.

7. A wastewater treatment system based on powdered activated carbon adsorption according to claim 6, characterized in that, The sludge return device includes a sludge pump (6) connected to the bottom of the sedimentation tank (5). The outlet of the sludge pump (6) is connected to a return pipe (20) and a conveying pipe. The return pipe (20) is connected to the primary mixing reaction tank (1).

8. A wastewater treatment system based on powdered activated carbon adsorption according to claim 7, characterized in that, Flow meters (29) are installed on the inlet pipe, feed pipe and return pipe (20). The flow meters (29) are connected to the controller (28). Electric valves are installed on the feed pipe, conveying pipe and return pipe (20). A sludge level gauge (21) is installed on the sedimentation tank (5). A COD online analyzer (24), a temperature sensor (26) and an ORP online analyzer (27) are installed on the primary mixing reaction tank (1) and the secondary mixing reaction tank (3). A dissolved oxygen online analyzer (25), a pH online analyzer (22) and an MLSS online analyzer (23) are installed on the primary aeration tank (2) and the secondary aeration tank (4). The COD online analyzer (24), temperature sensor (26), ORP online analyzer (27), dissolved oxygen online analyzer (25), pH online analyzer (22), MLSS online analyzer (23), electric valves, feed pump (12), sludge pump (6) and sludge level gauge (21) are all connected to the controller (28).

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