Activated sludge bypass reduction treatment system and method

Abstract

The invention discloses an activated sludge bypass reduction treatment system and method.The treatment system comprises a sewage biochemical reaction tank, a secondary sedimentation tank, a sludge tank, a sterilization wall-breaking reactor, a bypass recessive bacterium 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] The invention belongs to the field of sludge treatment, and in particular relates to an activated sludge bypass reduction treatment system and method. Background Art

[0002] A large amount of residual sludge is generated during the biochemical treatment of sewage using activated sludge, which is usually dehydrated by a filter press system and then transported out for treatment. The conventional landfill or incineration treatment of residual sludge has many problems, such as the unsustainability of sanitary landfill and the shortage of land resources, the high energy consumption of incineration and secondary pollution. Therefore, reducing the amount of residual sludge is the best solution to solve the sludge outlet from the source.

[0003] Therefore, it is necessary to propose a method that does not change the existing system operation process while achieving in-situ sludge reduction during system operation, so as to solve the problems of energy consumption and land occupation in the existing treatment methods. Summary of the invention

[0004] In view of the above problems, the present invention provides an activated sludge bypass reduction treatment system and method to solve the problems of energy consumption and land occupation in existing treatment methods.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: On the one hand, the present invention proposes an activated sludge bypass reduction treatment system, comprising a sewage biochemical reaction tank, a secondary sedimentation tank, a sludge tank, a bypass hidden bacteria culture tank and a sludge thickening tank, wherein the sewage biochemical reaction tank is provided with a sewage inlet and a sewage outlet, the sewage outlet is connected to the sewage inlet of the secondary sedimentation tank through a pipeline, the water 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 provided with a sludge return pump and a residual sludge pump, the sludge return pump outlet is connected to the water inlet inlet of the sewage biochemical reaction tank; the outlet of the residual sludge pump is divided into two branches, one branch is connected to a dehydration room, and the other is connected to the bypass hidden bacteria culture tank as a bypass pipeline, and the outlet of the bypass hidden bacteria culture tank is connected to the inlet of the sludge thickening tank.

[0006] Furthermore, the sludge thickening tank is provided with a carbon source return pump and a bypass sludge return pump, the outlet of the carbon source return pump is connected to the water inlet of the sewage biochemical reaction tank; the outlet of the bypass sludge return pump is connected to the aerobic section of the sewage biochemical reaction tank.

[0007] Furthermore, the treatment system also includes a sterilization and wall-breaking reactor, which is provided with a reaction gas outlet and is connected to the interior of the bypass hidden bacteria culture pool through a pipeline.

[0008] The present invention also proposes an activated sludge bypass reduction treatment method, which is carried out using the above-mentioned activated sludge bypass reduction treatment device, and the treatment process is as follows: sewage enters the sewage biochemical reaction tank through the sewage inlet, and enters the secondary sedimentation tank after removing COD and ammonia nitrogen, and mud and water separation is realized in the secondary sedimentation tank. The effluent from the secondary sedimentation tank enters the subsequent treatment unit, and the sludge at the bottom enters the sludge tank; the sludge tank is provided with a sludge return pump, and a large amount of activated sludge is returned to the water inlet end of the biochemical reaction tank, and part of it is pressurized by the residual sludge pump and sent to the dehydration room for pressure filtration and dehydration before external transportation and disposal; a bypass is set on the outlet pipe of the residual sludge pump to connect to the bypass hidden bacteria culture tank; a sterilization and wall-breaking reaction is set The reactor prepares high-pressure ozone, which is injected into the latent bacteria culture tank in the form of micro-nano bubbles to inactivate the activated sludge and then use it as a nutrient source for bacteriophage microorganisms, thereby promoting the latent growth of microorganisms. The activated sludge enters the sludge thickening tank, and a mechanical agitator is installed on the top of the sludge thickening tank to further enhance the latent growth of anaerobic microorganisms and achieve sludge reduction. The carbon-containing supernatant of the sludge thickening tank is used as the carbon source for the biochemical treatment system and is pumped back to the water inlet of the sewage biochemical reaction tank through the carbon source reflux pump. The highly active latently growing sludge at the bottom of the sludge thickening tank is pumped back to the aerobic section of the sewage biochemical reaction tank through the bypass sludge reflux pump, thereby achieving the effect of sludge bypass reduction in the entire system.

[0009] Furthermore, the sterilization and wall-breaking reactor can produce high-purity ozone, which is aerated and mixed with the activated sludge in the form of micro-nano bubbles through the aeration head installed at the bottom of the bypass hidden bacteria culture pool. This can effectively kill the nitrifying bacteria on the surface of the activated sludge, while providing nutrients for the hidden growth of other microorganisms, thereby achieving in-situ reduction of activated sludge.

[0010] Furthermore, regulating valves are provided on the outlet pipeline and bypass of the residual sludge pump, which can adjust the amount of discharged sludge and the amount of latently growing sludge in real time, control the number of microorganisms inactivated, ensure that the sludge reduction device will not have an adverse effect on the original biochemical system, and minimize the output of discharged sludge.

[0011] Furthermore, the sludge thickening tank is designed to be cylindrical, with a mechanical agitator on the top. The stirring rate is 3-5rpm. The sludge is slowly centrifuged to promote the separation of mud and water. At the same time, mechanical stirring can further enhance the hidden growth effect of anaerobic microorganisms.

[0012] Furthermore, the activated sludge bypass reduction system can be freely switched between operation and standby without any impact on the existing sewage biochemical treatment system and sludge treatment system, thus ensuring the safety of system operation.

[0013] Furthermore, the supernatant with high COD content at the top of the sludge concentration tank can be used as a carbon source for the anaerobic reaction of sewage and returned to the water inlet of the biochemical reaction tank. The high-concentration and high-activity sludge at the bottom is returned to the biochemical reactor, further enhancing the decarbonization and denitrification effect of the biochemical process section.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1) By setting up a bypass sludge in-situ reduction system on the outlet pipe of the residual sludge pump, the operation mode of the original sewage biochemical treatment system and the sludge treatment system will not be changed, and the free switching between the operation and standby of the bypass sludge reduction system can be realized. Under the premise of maintaining the effect of sewage biochemical treatment unchanged, the generation of residual sludge can be reduced, and the sludge reduction efficiency can reach 30%~50%, which greatly reduces the subsequent sludge dehydration, transportation and terminal disposal costs.

[0015] 2) The inactivation effect of ozone on microorganisms is used to achieve the cell fusion and wall breaking of nitrifying bacteria on the surface of activated sludge, releasing biological macromolecules, including proteins, sugars, nucleic acids, etc., providing nutrients required for the latent growth and alienation metabolism of bacteriophage microorganisms, and realizing the reduction of activated sludge from the source. The activated sludge is aerated and stirred by ozone bubbles in the form of micro-nano bubbles, which improves the utilization rate of ozone and reduces the operating cost of ozone preparation.

[0016] 3) The activated sludge after hidden growth is layered and then utilized as a resource. The high-carbon supernatant is used as a carbon source to supplement the anaerobic section of the biochemical system, and the highly active hidden growth sludge is returned to the aerobic section. The characteristics of the hidden growth of sludge are fully utilized, and the organic carbon released by lysis is supplemented as a carbon source for denitrification. The hidden growth dominant bacteria cultured in the bypass system are introduced into the biochemical reaction system for sludge reduction treatment, which can further improve the in-situ sludge reduction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The present invention is a process flow chart of an activated sludge bypass reduction treatment system and method.

[0018] In the figure: 1. Sewage biochemical reaction tank; 2. Secondary sedimentation tank; 3. Sludge tank; 4. Sludge return pump; 5. Residual sludge pump; 6. Sterilization wall breaking reactor; 7. Bypass hidden bacteria culture tank; 8. Sludge concentration tank; 9. Carbon source return pump; 10. Bypass sludge return pump. The direction indicated by the arrow is the direction of water or sludge flow. DETAILED DESCRIPTION

[0019] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0020] like Figure 1As shown, an activated sludge bypass reduction treatment system includes a sewage biochemical reaction tank 1, a secondary sedimentation tank 2, a sludge tank 3, a sludge return pump 4, a residual sludge pump 5, a sterilization and wall-breaking reactor 6, a bypass hidden bacteria culture tank 7, a sludge concentration tank 8, a carbon source return pump 9 and a bypass sludge return pump 10.

[0021] The sewage biochemical reaction tank 1 is provided with a sewage inlet and a sewage outlet. The sewage outlet is connected to the sewage inlet of the secondary sedimentation tank 2 through a pipeline. The water 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 provided with a sludge return pump 4 and a residual sludge pump 5. The outlet of the sludge return pump 4 is connected to the water inlet inlet of the sewage biochemical reaction tank 1; the outlet of the residual sludge pump 5 is divided into two branches, one branch is connected to the dehydration room, and the other is connected to the bypass hidden bacteria culture tank 7 as a bypass pipeline. The outlet of the bypass hidden bacteria culture tank 7 is connected to the inlet of the sludge concentration tank 8.

[0022] The sludge thickening tank 8 is provided 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 water inlet of the sewage biochemical reaction tank 1; the outlet of the bypass sludge return pump 10 is connected to the aerobic section of the sewage biochemical reaction tank 1.

[0023] The sterilization and wall-breaking reactor 6 is provided with a reaction gas outlet, and is connected to the inside of the bypass hidden bacteria culture pool 7 through a pipeline.

[0024] The treatment method of the activated sludge bypass reduction treatment system of the present application includes the following processes: After the sewage passes through the sewage biochemical reaction tank 1 to remove pollutants such as COD and ammonia nitrogen, it enters the secondary sedimentation tank 2, where mud and water are separated. The effluent from the secondary sedimentation tank 2 enters the subsequent treatment unit, and the sludge at the bottom enters the sludge tank 3. The sludge tank 3 is equipped with a sludge return pump 4, and a large amount of activated sludge returns to the water inlet end of the sewage biochemical reaction tank 1. Part of it is pressurized by the residual sludge pump 5 and sent to the dewatering room for pressure filtration and dehydration before external transportation and disposal. A bypass is set on the outlet pipe of the residual sludge pump 5, which is connected to the bypass hidden bacteria culture tank 7. A sterilization and wall breaking reactor 6 is set to prepare high-pressure ozone, which is injected into the bypass hidden bacteria culture tank 7 in the form of micro-nano bubbles, and the activated sludge is inactivated and fused and broken, and then used as a nutrient source for bacteriophage microorganisms, promoting the hidden growth of microorganisms. The activated sludge enters the sludge concentration tank 8, and a mechanical agitator is set on the top of the tank to further strengthen the hidden growth of anaerobic microorganisms and achieve sludge reduction. The carbon-containing supernatant of the sludge thickening tank 8 is used as the carbon source of the biochemical treatment system and is pumped back to the water inlet of the sewage biochemical reaction tank 1 through the carbon source return pump 9. The high-activity hidden growth sludge at the bottom of the sludge thickening tank 8 is pumped back to the aerobic section of the sewage biochemical reaction tank 1 through the bypass sludge return pump 10, achieving the effect of sludge bypass reduction in the whole system.

[0025] Take a sewage treatment plant with a sewage treatment capacity of 30,000 tons / day as an example. The oxidation ditch process is designed, and the single ditch treats 6,000 tons / day of water. Ditch No. 1 is used as a blank group without any treatment, and Ditch No. 2 is equipped with an activated sludge bypass reduction treatment system. After stable operation for half a year, the sludge discharge is compared and calculated.

[0026] Table 1 Summary of average daily mud production under different conditions Average daily dry weight of sludge from No. 1 ditch kg 450 Average daily dry sludge production of No. 2 ditch kg 270 Reduction percentage of residual sludge % 40 The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An activated sludge bypass reduction treatment system, characterized in that: The invention comprises a sewage biochemical reaction tank (1), a secondary sedimentation tank (2), a sludge tank (3), a bypass hidden bacteria culture tank (7) and a sludge concentration tank (8), wherein the sewage biochemical reaction tank (1) is provided with a sewage inlet and a sewage outlet, wherein the sewage outlet is connected to the sewage inlet of the secondary sedimentation tank (2) through a pipeline, the water outlet of the secondary sedimentation tank (2) is connected to a 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 provided with a sludge return pump (4) and a residual sludge pump (5), the outlet of the sludge return pump (4) is connected to the water inlet of the sewage biochemical reaction tank (1); the outlet of the residual sludge pump (5) is divided into two branches, one branch is connected to a dewatering room, and the other branch is connected to the bypass hidden bacteria culture tank (7) as a bypass pipeline, and the outlet of the bypass hidden bacteria culture tank (7) is connected to the inlet of the sludge concentration tank (8).

2. The activated sludge bypass reduction treatment system according to claim 1, characterized in that: The sludge concentration tank (8) is provided 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 water inlet of the sewage biochemical reaction tank (1); and the outlet of the bypass sludge return pump (10) is connected to the aerobic section of the sewage biochemical reaction tank (1).

3. An activated sludge bypass reduction treatment system according to claim 2, characterized in that: The treatment system further comprises a sterilization and wall-breaking reactor (6), wherein the sterilization and wall-breaking reactor (6) is provided with a reaction gas outlet and is connected to the interior of the bypass hidden bacteria culture pool (7) through a pipeline.

4. An activated sludge bypass reduction treatment method, using the activated sludge bypass reduction treatment system as claimed in claim 3, characterized in that: The process is as follows: Sewage enters the sewage biochemical reaction tank (1) through the sewage inlet, and enters the secondary sedimentation tank (2) after COD and ammonia nitrogen are removed. Mud and water are separated in the secondary sedimentation tank (2). The effluent of the secondary sedimentation tank (2) enters the subsequent treatment unit, and the sludge at the bottom enters the sludge tank (3). The sludge tank (3) is provided with a sludge return pump (4) and a residual sludge pump (5). A large amount of activated sludge is returned to the water inlet end of the sewage biochemical reaction tank (1). Part of the activated sludge is pressurized by the residual sludge pump (5) and sent to the dehydration room for pressure filtration and dehydration before being transported out for disposal. A bypass is set on the outlet pipe of the residual sludge pump (5) and connected to the bypass hidden bacteria culture tank (7). A sterilization wall-breaking reactor (6) is set to prepare high-pressure ozone, and micro-nano bubbles are used to generate high-pressure ozone. The activated sludge is pumped into a bypass hidden bacteria culture tank (7) to inactivate the activated sludge by fusion and cell wall breaking reaction, and then used as a nutrient source for bacteriophage microorganisms, thereby promoting the hidden growth of the microorganisms; the activated sludge enters a sludge thickening tank (8), and a mechanical agitator is arranged on the top of the sludge thickening tank (8) to further strengthen the hidden growth of anaerobic microorganisms and achieve sludge reduction; the carbon-containing supernatant of the sludge thickening tank (8) is used as a carbon source for the biochemical treatment system and is pumped back to the water inlet end of the sewage biochemical reaction tank (1) through a carbon source return pump (9); the highly active hidden growth sludge at the bottom of the sludge thickening tank (8) is pumped back to the aerobic section of the sewage biochemical reaction tank (1) through a bypass sludge return pump (10), thereby achieving the effect of sludge bypass reduction in the entire system.

5. The activated sludge bypass reduction treatment method according to claim 4, characterized in that: The sterilization and wall-breaking reactor (6) is used to prepare high-purity ozone, which is aerated and mixed with the activated sludge in the form of micro-nano bubbles through an aeration head arranged at the bottom of the bypass hidden bacteria culture pool (7).

6. The activated sludge bypass reduction treatment method according to claim 4, characterized in that: The outlet pipeline and bypass of the residual sludge pump (5) are both provided with regulating valves for real-time regulating the amount of discharged sludge and the amount of latently growing sludge, controlling the amount of inactivated microorganisms, ensuring that the sludge reduction device does not have an adverse effect on the original biochemical system, and minimizing the amount of discharged sludge.

7. The activated sludge bypass reduction treatment method according to claim 4, characterized in that: The sludge thickening tank (8) is cylindrical, with a mechanical stirrer provided on the top, and the stirring rate is 3-5 rpm.

8. The activated sludge bypass reduction treatment method according to claim 4, characterized in that: The supernatant with high COD content at the top of the sludge thickening tank (8) is used as a carbon source for the anaerobic reaction of the sewage and is returned to the water inlet of the sewage biochemical reaction tank (1); the high-concentration and high-activity sludge at the bottom is returned to the aerobic section of the sewage biochemical reaction tank (1) to enhance the decarbonization and denitrification effects of the biochemical process section.

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