Activated sludge bypass reduction treatment system

Abstract

The utility model discloses an activated sludge bypass reduction treatment system, which comprises a sewage biochemical reaction tank, a secondary sedimentation tank, a sludge tank, a sterilization wall-breaking reactor, a bypass recessive bacteria culture tank and a sludge concentration tank, a sewage outlet of the sewage biochemical reaction tank is communicated with a sewage inlet of the secondary sedimentation tank, and a sludge outlet of the secondary sedimentation tank is communicated with an inlet of the sludge tank. The sludge tank is provided with a sludge reflux pump and a residual sludge pump; an outlet of the sludge reflux pump is communicated with a water inlet end inlet of the sewage biochemical reaction tank; an outlet of the excess sludge pump is divided into two branches, one branch is communicated to the dewatering machine room, the other branch is connected to the bypass recessive bacterium culturing pool as a bypass pipeline, and an outlet of the bypass recessive bacterium culturing pool is communicated with an inlet of the sludge concentration pool. A carbon source reflux pump outlet of the sludge concentration tank is communicated with a water inlet end inlet of the sewage biochemical reaction tank; and the outlet of the bypass sludge reflux pump is communicated with the aerobic section of the sewage biochemical reaction tank. According to the application, the sludge in-situ reduction is realized in the system operation while the existing system operation process is not changed.

Description

Technical Field

[0001] This utility model belongs to the field of sludge treatment, specifically relating to an activated sludge bypass reduction treatment system. Background Technology

[0002] Wastewater treatment using activated sludge generates a large amount of excess sludge, which is typically dewatered using a filter press system and then transported off-site. Conventional landfilling or incineration methods for this excess sludge have several problems, such as the unsustainability of sanitary landfills and the scarcity of land resources, and the high energy consumption and secondary pollution associated with incineration. Therefore, reducing the amount of excess sludge generated is the best solution to address sludge disposal at its source.

[0003] Therefore, there is a need to propose a treatment system that does not change the existing system operation process, but can achieve in-situ sludge reduction during system operation, in order to solve the problems of energy consumption and land occupation of the existing treatment methods. Utility Model Content

[0004] To address the aforementioned issues, this invention provides an activated sludge bypass reduction treatment system, which solves the problems of energy consumption and land occupation associated with existing treatment methods.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] This utility model proposes an activated sludge bypass reduction treatment system, including a wastewater biochemical reaction tank, a secondary sedimentation tank, a sludge tank, a bypass concealed culture tank, and a sludge thickening tank. The wastewater biochemical reaction tank is equipped with a wastewater inlet and a wastewater outlet. The wastewater outlet is connected to the wastewater inlet of the secondary sedimentation tank via a pipeline. The outlet of the secondary sedimentation tank is connected to a subsequent treatment unit. The sludge outlet of the secondary sedimentation tank is connected to the inlet of the sludge tank. The sludge tank is equipped with a sludge return pump and a waste sludge pump. The outlet of the sludge return pump is connected to the inlet of the wastewater biochemical reaction tank. The outlet of the waste sludge pump is divided into two branches. One branch is connected to the dewatering room, and the other branch is connected as a bypass pipeline to the bypass concealed culture tank. The outlet of the bypass concealed culture tank is connected to the inlet of the sludge thickening tank.

[0007] Furthermore, the sludge thickening tank is equipped with a carbon source return pump and a bypass sludge return pump. The outlet of the carbon source return pump is connected to the inlet of the wastewater biochemical reaction tank; the outlet of the bypass sludge return pump is connected to the aerobic section of the wastewater biochemical reaction tank.

[0008] Furthermore, the treatment system also includes a sterilization and cell-wall breaking reactor, which is equipped with a reaction gas outlet and connected to the interior of a bypass concealed culture tank via a pipeline.

[0009] This utility model proposes a treatment method for an activated sludge bypass reduction system, comprising the following processes: Wastewater enters a wastewater biochemical reaction tank through a wastewater inlet, and after COD and ammonia nitrogen are removed, it enters a secondary sedimentation tank, where sludge-water separation is achieved. The effluent from the secondary sedimentation tank enters a subsequent treatment unit, and the sludge at the bottom enters a sludge tank. The sludge tank is equipped with a sludge return pump, and a large amount of activated sludge is returned to the inlet of the biochemical reaction tank. A portion is pressurized by a residual sludge pump and sent to a dewatering room for pressure filtration and dewatering before being transported off-site for disposal. A bypass is set on the outlet pipe of the residual sludge pump, connecting to a bypass concealed culture tank. A sterilization and cell-wall breaking reactor is set up to prepare high-pressure odor control. Oxygen, in the form of micro-nano bubbles, is injected into the occult culture tank to inactivate and disrupt the cell walls of activated sludge, serving as a nutrient source for bacteriophages and promoting their occult growth. The activated sludge then enters the sludge thickening tank, where mechanical agitation at the top further enhances the occult growth of facultative anaerobic microorganisms, achieving sludge reduction. The carbon-containing supernatant from the sludge thickening tank serves as the carbon source for the biological treatment system and is pumped back to the inlet of the wastewater biological reaction tank via a carbon source return pump. The highly active, occult-grown sludge at the bottom of the sludge thickening tank is pumped back to the aerobic section of the wastewater biological reaction tank via a bypass sludge return pump, achieving sludge bypass reduction across the entire system.

[0010] Furthermore, the sterilization and cell-wall breaking reactor can produce high-purity ozone, which is then aerated and mixed with activated sludge in the form of micro-nano bubbles through the aeration heads set at the bottom of the bypass hidden culture tank. This effectively kills nitrifying bacteria on the surface of the activated sludge, while providing nutrients for the hidden growth of other microorganisms, thus achieving in-situ reduction of activated sludge.

[0011] Furthermore, regulating valves are installed on the outlet pipeline and bypass of the residual sludge pump, which can adjust the amount of sludge discharged and the amount of sludge that grows covertly in real time, control the number of microorganisms inactivated, and ensure that the sludge reduction device will not have an adverse effect on the original biochemical system while minimizing the output of sludge discharged.

[0012] Furthermore, the sludge thickening tank is designed in a cylindrical shape and equipped with a mechanical agitator at the top. The agitation rate is 3-5 rpm. Through the slow centrifugal operation of the sludge, the sludge is separated from the water. At the same time, the mechanical agitation can further enhance the latent growth effect of facultative anaerobic microorganisms.

[0013] Furthermore, the activated sludge bypass reduction system can be freely switched between operation and standby without affecting the existing wastewater biological treatment system and sludge treatment system, ensuring the safety of system operation.

[0014] Furthermore, the high-COD supernatant at the top of the sludge thickening tank can serve as a carbon source for the anaerobic wastewater reaction and is returned to the inlet of the biological reactor. The high-concentration, highly active sludge at the bottom is returned to the biological reactor, further enhancing the decarbonization and denitrification effects of the biological process section.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1) By setting up a bypass sludge reduction system on the outlet pipeline of the excess sludge pump, the operation mode of the original sewage biological treatment system and sludge treatment system can be changed. The system can be freely switched between operation and standby. While maintaining the effect of sewage biological treatment, the generation of excess sludge can be reduced. The sludge reduction efficiency can reach 30%~50%, which greatly reduces the subsequent sludge dewatering, transportation and terminal disposal costs.

[0017] 2) Utilizing ozone's inactivation effect on microorganisms enables the lysis and disruption of cell walls of nitrifying bacteria on the surface of activated sludge, releasing biomolecules such as proteins, carbohydrates, and nucleic acids. This provides nutrients for the latent growth and catabolism of bacteriophages, achieving volume reduction of activated sludge at its source. Aeration and mixing of activated sludge using ozone bubbles in the form of micro-nano bubbles improves ozone utilization and reduces the operating costs of ozone preparation.

[0018] 3) After the sludge undergoes cryptic growth, it is stratified and utilized for resource recovery. The supernatant with high carbon content is used as a carbon source to supplement the anaerobic section of the biological system, while the highly active cryptic growth sludge is returned to the aerobic section. This fully utilizes the characteristics of cryptic growth of sludge, and the organic carbon released by cell lysis is used as a carbon source for denitrification. The dominant cryptic growth bacteria cultured in the bypass system are introduced into the biological reaction system for sludge reduction treatment, which can further improve the efficiency of in-situ sludge reduction. Attached Figure Description

[0019] Figure 1 This is a process flow diagram of an activated sludge bypass reduction treatment system according to the present invention.

[0020] In the diagram: 1. Wastewater biological reaction tank; 2. Secondary sedimentation tank; 3. Sludge tank; 4. Sludge return pump; 5. Waste sludge pump; 6. Sterilization and cell wall breaking reactor; 7. Bypass concealed culture tank; 8. Sludge thickening tank; 9. Carbon source return pump; 10. Bypass sludge return pump. The arrows indicate the direction of water or sludge flow. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0022] like Figure 1As shown, an activated sludge bypass reduction treatment system includes a wastewater biochemical reaction tank 1, a secondary sedimentation tank 2, a sludge tank 3, a sludge return pump 4, a waste sludge pump 5, a sterilization and cell disruption reactor 6, a bypass concealed culture tank 7, a sludge thickening tank 8, a carbon source return pump 9, and a bypass sludge return pump 10.

[0023] The wastewater biochemical reaction tank 1 is equipped with a wastewater inlet and a wastewater outlet. The wastewater outlet is connected to the wastewater inlet of the secondary sedimentation tank 2 via a pipeline. The outlet of the secondary sedimentation tank 2 is connected to the subsequent treatment unit. The sludge outlet of the secondary sedimentation tank 2 is connected to the inlet of the sludge tank 3. The sludge tank 3 is equipped with a sludge return pump 4 and a residual sludge pump 5. The outlet of the sludge return pump 4 is connected to the inlet of the wastewater biochemical reaction tank 1. The outlet of the residual sludge pump 5 is divided into two branches. One branch is connected to the dewatering room, and the other branch is connected to the bypass hidden culture tank 7 as a bypass pipeline. The outlet of the bypass hidden culture tank 7 is connected to the inlet of the sludge thickening tank 8.

[0024] The sludge thickening tank 8 is equipped with a carbon source return pump 9 and a bypass sludge return pump 10. The outlet of the carbon source return pump 9 is connected to the inlet of the wastewater biochemical reaction tank 1; the outlet of the bypass sludge return pump 10 is connected to the aerobic section of the wastewater biochemical reaction tank 1.

[0025] The sterilization and cell wall breaking reactor 6 is equipped with a reaction gas outlet and is connected to the interior of the bypass concealed culture tank 7 through a pipeline.

[0026] The treatment method of the activated sludge bypass reduction system of this application includes the following processes:

[0027] Wastewater, after passing through the wastewater biological reaction tank 1 to remove pollutants such as COD and ammonia nitrogen, enters the secondary sedimentation tank 2, where sludge-water separation is achieved. The effluent from the secondary sedimentation tank 2 enters the subsequent treatment unit, while the sludge at the bottom enters the sludge tank 3. The sludge tank 3 is equipped with a sludge return pump 4, which returns a large amount of activated sludge to the inlet of the wastewater biological reaction tank 1. A portion of this sludge is pressurized by the excess sludge pump 5 and sent to the dewatering room for filter press dewatering before being transported off-site for disposal. A bypass is installed on the outlet pipe of the excess sludge pump 5, connecting to a bypass hidden culture tank 7. A sterilization and cell-wall breaking reactor 6 generates high-pressure ozone, which is injected into the bypass hidden culture tank 7 in the form of micro-nano bubbles. This ozone inactivates and breaks down the cell walls of the activated sludge, serving as a nutrient source for bacteriophages and promoting their latent growth. The activated sludge then enters the sludge thickening tank 8, where mechanical stirring is installed at the top to further enhance the latent growth of facultative anaerobic microorganisms and achieve sludge reduction. The carbon-containing supernatant from sludge thickening tank 8 serves as the carbon source for the biological treatment system and is returned to the inlet of wastewater biological reaction tank 1 via carbon source return pump 9. The highly active, latently growing sludge at the bottom of sludge thickening tank 8 is returned to the aerobic section of wastewater biological reaction tank 1 via bypass sludge return pump 10, achieving the effect of sludge bypass reduction throughout the system.

[0028] Taking a wastewater treatment plant with a wastewater treatment capacity of 30,000 tons / day as an example, the design adopts the oxidation ditch process, with a single ditch treating 6,000 tons / day. Ditch No. 1 serves as a blank group and does not employ any treatment, while Ditch No. 2 is equipped with an activated sludge bypass reduction treatment system. After six months of stable operation, the sludge discharge volume is calculated by comparison.

[0029] Table 1 Summary of Average Daily Sludge Production under Different Conditions

[0030] Average daily dry yield of sludge from Ditch No. 1 kg 450 Average daily dry sludge production from Ditch No. 2 kg 270 Percentage reduction in residual sludge % 40

[0031] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. An activated sludge bypass reduction treatment system, characterized in that, The system includes a wastewater biochemical reaction tank (1), a secondary sedimentation tank (2), a sludge tank (3), a bypass hidden culture tank (7), and a sludge thickening tank (8). The wastewater biochemical reaction tank (1) is equipped with a wastewater inlet and a wastewater outlet. The wastewater outlet is connected to the wastewater inlet of the secondary sedimentation tank (2) through a pipeline. The outlet of the secondary sedimentation tank (2) is connected to the subsequent treatment unit. The sludge outlet of the secondary sedimentation tank (2) is connected to the inlet of the sludge tank (3). The sludge tank (3) is equipped with a sludge return pump (4) and a residual sludge pump (5). The outlet of the sludge return pump (4) is connected to the inlet of the wastewater biochemical reaction tank (1). The outlet of the residual sludge pump (5) is divided into two branches. One branch is connected to the dewatering room, and the other branch is connected to the bypass hidden culture tank (7) as a bypass pipeline. The outlet of the bypass hidden culture tank (7) is connected to the inlet of the sludge thickening tank (8).

2. The activated sludge bypass reduction treatment system according to claim 1, characterized in that, The sludge thickening tank (8) is equipped with a carbon source return pump (9) and a bypass sludge return pump (10). The outlet of the carbon source return pump (9) is connected to the inlet of the wastewater biochemical reaction tank (1). The outlet of the bypass sludge return pump (10) is connected to the aerobic section of the wastewater biochemical reaction tank (1).

3. The activated sludge bypass reduction treatment system according to claim 2, characterized in that, The treatment system also includes a sterilization and cell-wall breaking reactor (6), which is provided with a reaction gas outlet and is connected to the interior of a bypass hidden culture tank (7) through a pipeline.

4. The activated sludge bypass reduction treatment system according to claim 3, characterized in that, The sterilization and cell wall breaking reactor (6) is used to prepare high-purity ozone. An aeration head is set at the bottom of the bypass hidden bacterial culture tank (7) to realize the aeration and mixing of high-purity ozone with activated sludge in the form of micro-nano bubbles.

5. The activated sludge bypass reduction treatment system according to claim 4, characterized in that, The residual sludge pump (5) is equipped with regulating valves on both the outlet pipeline and the bypass pipeline, which are used to adjust the amount of sludge discharged and the amount of sludge that grows covertly in real time.

6. The activated sludge bypass reduction treatment system according to claim 4, characterized in that, The sludge thickening tank (8) is cylindrical and equipped with a mechanical agitator at the top.

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