A biofilm forming device and biofilm forming method for filler using leaching method

Abstract

The present application discloses a biofilm forming device and a biofilm forming method for fillers using a filtration and leaching method, comprising a sludge stirring tank, a concentrated wastewater storage device, a reactor, a sludge discharge device, a main air pipe, a branch air pipe, a water inlet main pipe, a water distribution branch, a water distribution plate and a water distribution opening structure; the device utilizes the filtration and leaching method to circulate sludge liquid in the reactor at a high flow rate, and simultaneously utilizes natural ventilation and a blower to introduce air to achieve rapid biofilm forming, thereby achieving the purpose of shortening the startup time; the device is small in size, and has lower energy consumption than traditional methods, and is suitable for promotion and application.

Description

Technical Field

[0001] The present application relates to the field of sewage treatment, and in particular to a device and a biofilm-forming method for carrying out biofilm loading (biofilm formation) on a filler for sewage treatment. Background Art

[0002] Fillers are often used in sewage treatment. Biofilms are loaded on fillers to help degrade and remove pollutants in the water, thereby achieving the purpose of purifying the water. At present, the commonly used biofilm methods include direct biofilm method and indirect biofilm method, both of which aim to make the sewage treatment system run and eventually form biofilm.

[0003] The traditional method is to add activated sludge from the sewage plant into the reactor and use aeration, stirring and other methods to make the biofilm grow on the filler. This period generally lasts 7-14 days, which is called the start-up time of the sewage treatment device. However, the existing method has the problems of head aeration and high energy consumption, and the equipment required for biofilm growth is large in size and occupies a large area, which is not conducive to urban sewage treatment applications. Summary of the invention

[0004] In order to improve the biofilm growth efficiency and reduce the energy consumption of the biofilm growth process, the present invention provides a biofilm growth device, which utilizes the filtration and leaching method to circulate the sludge liquid in the reactor at a high flow rate, and simultaneously utilizes natural ventilation and a blower to introduce air to achieve rapid biofilm growth, thereby achieving the purpose of shortening the startup time. The device is small in size and has lower energy consumption than traditional methods.

[0005] This application is implemented through the following technical solutions:

[0006] The present invention first provides a leaching filler biofilm device, comprising a sludge stirring tank provided with a stirrer, a second sludge discharge device provided at the bottom of the sludge stirring tank, and the second sludge discharge device comprising a sludge discharge pipe and a valve;

[0007] The concentrated wastewater storage is connected to the sludge stirring tank through a pipeline provided with a sample feed pump, and the sludge stirring tank is connected to the water inlet provided on the top of the reactor through a water inlet pipe provided with a water inlet pump;

[0008] The reactor is provided with a water outlet at the bottom, which is connected to the sludge stirring tank through a drainage pipe; the reactor is also provided with a first sludge discharge device connected to the sludge stirring tank at the bottom to discharge the sludge generated by the reactor into the sludge stirring tank; in the reactor, the main air pipe is arranged longitudinally along the axis of the reactor, one end of the main air pipe is connected to a blower arranged outside the reactor, and the other end is connected to at least one annular branch air pipe through a four-way pipe; the branch air pipe is arranged circumferentially along the inner wall of the reactor. In a specific implementation, at least one layer of branch air pipes connected to the main air pipe can be arranged according to the height of the reactor, and these branch air pipes are evenly distributed at different heights inside the reactor; a plurality of through-going air outlets are arranged at the bottom of the branch air pipe; the main air pipe and the branch air pipe together constitute a blast system; the number of air outlets is set according to the cross-sectional area of ​​the reactor, and the service area of ​​a single air outlet is preferably 0.4-0.8 m 2 ;

[0009] A single-layer water distribution pipe is arranged at the top of the reactor, and is composed of a water inlet main pipe and a plurality of water distribution branches, which are evenly distributed around the water inlet main pipe in a radial shape (in a specific implementation, the number of water distribution branches can be adjusted according to the cross-sectional area of ​​the reactor); one end of the water inlet main pipe passes through the water inlet provided on the upper surface of the reactor and is connected to the water inlet pipe, and the other end is connected to the water distribution branch; a plurality of through water inlet openings are provided on the bottom surface of the water distribution branch;

[0010] The bottom surface of the water distribution manifold is also provided with a shutter; the shutter is composed of a door leaf, a small door shaft and a large door shaft, and the three constitute a horizontal shutter water volume control system; the door leaf is an iron sheet with a number of small holes at intervals, the shape of the small holes matches the water inlet opening, each small hole is provided with an iron small door shaft at both ends, and a large door shaft is also provided at the door leaf 22 close to the inner wall of the reactor; in a specific implementation, the shutter can be controlled by a valve provided outside the water distribution manifold so as to move forward and backward along the lower surface of the water distribution manifold, thereby increasing or decreasing the effective water flow area of ​​the water inlet opening. When the water volume is small, the water flows out from the water inlet opening closer to the water inlet main pipe. At this time, the shutter can be moved forward to reduce the effective water flow area of ​​the opening, so that the water can flow out from the water inlet opening farther from the water inlet main pipe, thereby enhancing the water distribution effect. When the water volume increases, the shutter can be moved backward to increase the effective water flow area of ​​the water inlet opening and reduce the water flow rate;

[0011] The water distribution plate is a circular structure fixedly arranged on the inner wall of the reactor and located below the water distribution pipe. The outer diameter of the water distribution plate matches the cross-sectional diameter of the reactor. The circular channel in the center of the water distribution plate is used to check the water distribution. The surface of the water distribution plate is provided with a number of through water distribution openings. The sludge-containing wastewater flowing out of the water distribution pipe at a high speed passes through the filler evenly under the further water distribution action of the water distribution plate.

[0012] In a specific implementation, the reactor can be cylindrical or other structures, and its material is a hard material, preferably carbon steel;

[0013] Preferably, in the above-mentioned leaching method filler biofilm hanging device, the aperture of the water inlet opening increases gradually from the axis to the edge, that is, the aperture of the water inlet opening closer to the water inlet main pipe is smaller, and the aperture of the water inlet opening closer to the inner wall of the reaction tank is larger, so as to ensure that water flows out evenly from all holes.

[0014] Preferably, in the above-mentioned filtration and leaching filler biofilm forming device, the annular water distribution plate is composed of a number of sectors with the same area to facilitate assembly and disassembly.

[0015] Secondly, the present invention provides a biofilm forming method using the above-mentioned biofilm forming device using a leaching method, and the specific steps are as follows:

[0016] 1) The sludge (rich in microorganisms) taken from the aerobic tank of the sewage plant is placed in the sludge mixing tank. Under the action of the agitator, the sludge is evenly fluidized in the sludge mixing tank. Then the water inlet pump is turned on. The sewage in the sludge mixing tank enters the reactor from the water inlet pipe through the water inlet pump. In the reactor, the sewage passes through the water inlet main pipe and the water distribution branch, and passes through the filler at a high flow rate. The filler intercepts the sludge in the sludge liquid, and the effluent returns to the sludge mixing tank through the drain pipe. After repeating this process several times, the effluent from the drain pipe gradually becomes clear.

[0017] 2) In the sludge mixing tank, when the COD and ammonia nitrogen concentrations in the sewage are low, the concentrated sewage (with a sodium acetate concentration of 40 g / L and an ammonium chloride concentration of 3 g / L) can be pumped into the concentrated sewage storage tank 7 by controlling the sampling pump 8 to keep the nutrient concentration of the wastewater in the entire system in the sludge mixing tank 2 stable; an online water quality monitoring system (such as CODmax II potassium dichromate COD detector, Hach and Amtax sc ammonia nitrogen online monitor, both of which are conventional monitoring systems in this field) can also be set in the sludge mixing tank to monitor the COD and ammonia nitrogen concentrations;

[0018] 3) When the sewage in the sludge mixing tank is basically clarified and the biofilm formation is finished, the first and second sludge discharge devices are opened through valves to discharge the sewage in the reactor and the sludge mixing tank;

[0019] 4) When there is sludge accumulation at the bottom of the reactor during biofilm formation, open the first sludge discharge device at the bottom of the reactor to discharge the sludge into the sludge stirring tank for recirculation;

[0020] 5) During the operation of the device, air first enters the main air pipe through the blower, then is diverted to the diverter air pipe through the four-way diverter, and then discharged through the air outlet, so that there is sufficient oxygen at different heights inside the reactor. Since the air outlets on the diverter air pipe are evenly distributed on the cross-sections at different heights of the reactor, it can ensure that oxygen is evenly distributed at different positions of the reactor, and complete the microbial biofilm formation on the surface of the filler; this ventilation process can ensure that the biofilm is in a fully aerobic environment during the biofilm formation process, thereby accelerating the metabolism of microorganisms.

[0021] Preferably, during operation of the above device, the flow rate of the water inlet main pipe 13 is in the range of 3-5 m / h, and all water inlet openings of the water distribution branches can quickly discharge water, and the flow rate thereof is lower than the flow rate of the water inlet main pipe.

[0022] In this application, the filler material is conventional filler materials such as polyurethane foam (such as the products of Jiangsu Aiqin Environmental Protection Technology Co., Ltd.) or high-strength polyethylene filler (such as the products of Tongxiang Xiaolaoban Special Plastic Products Co., Ltd.).

[0023] The invention has the beneficial effect that the biofilm can be quickly loaded under low energy consumption conditions. Due to the high filling rate of the filler in the reactor, the filler has a high interception rate for the activated sludge, thereby realizing rapid loading of the biofilm. The filler is in a non-fluidized state during the biofilm formation process, thereby reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the combination of the filtration and leaching method filler biofilm forming device of the present invention.

[0025] Figure 2 It is a cross-sectional schematic diagram of the blowing system in the reactor.

[0026] Figure 3 This is a schematic diagram of the water distribution pipe structure in the reactor.

[0027] Figure 4 It is a schematic diagram of the water distribution plate structure in the reactor.

[0028] Figure 5 It is a schematic diagram of a single water inlet opening and shutter structure.

[0029] Figure 6 It is a schematic diagram of the water distribution manifold and shutter structure.

[0030] Among them: 1. Reactor, 2. Sludge mixing tank, 3. Agitator, 4. Water inlet pump, 5. Water inlet pipe, 6. Drain pipe, 7. Concentrated wastewater storage tank, 8. Sampling pump, 9.1. First sludge discharge device, 9.2. Second sludge discharge device, 10. Fan, 11. Main air pipe, 12. Branch air pipe, 13. Water inlet main pipe, 14. Water distribution branch, 15. Water inlet opening, 16. Shutter, 17. Water distribution pipe, 18. Small door axis, 19. Water distribution plate, 20. Water distribution opening, 21. Large door axis, 22. Door leaf. DETAILED DESCRIPTION

[0031] The following is a further description of the filtration and leaching filler biofilm forming device of the present application in conjunction with the accompanying drawings.

[0032] like Figure 1As shown, a leaching filler biofilm forming device comprises a sludge stirring tank 2 provided with a stirrer 3, a second sludge discharge device 9.2 is provided at the bottom of the sludge stirring tank 2, and the second sludge discharge device 9.2 is composed of a sludge discharge pipe (model DN80) and a valve;

[0033] The concentrated wastewater storage 7 is connected to the sludge stirring tank 2 through a pipeline provided with a sampling pump 8, and the sludge stirring tank 2 is connected to the water inlet provided at the top of the reactor 1 through a water inlet pipe 5. A water inlet pump 4 is provided on the pipeline between the sludge stirring tank 2 and the water inlet pipe 5;

[0034] A water outlet is provided at the bottom of the reactor 1, and the water outlet is connected to the sludge stirring tank 2 through a drain pipe 6; a first sludge discharge device 9.1 connected to the sludge stirring tank 2 is also provided at the bottom of the reactor 1, and the first sludge discharge device 9.1 can discharge the sludge generated by the reactor 1 into the sludge stirring tank 2; in this embodiment, the reactor 1 is a cylindrical structure, and its material is carbon steel (it can also be other common hard materials in specific applications).

[0035] like Figure 2 As shown, in the reactor 1, the main air pipe 11 is arranged longitudinally along the axis of the reactor 1, one end of the main air pipe 11 is connected to the blower 10 arranged outside the reactor 1, and the other end is connected to a plurality of annular branch air pipes 12 through a four-way pipe. The number of layers of the annular branch air pipes is determined by the height of the reactor, and the service height of each layer of air pipes is 1m; in this embodiment, there are 3 layers of annular branch air pipes 12, each layer of branch air pipes 12 is arranged circumferentially along the inner wall of the reactor 1, and these 3 layers of branch air pipes 12 are evenly distributed on the inner wall of the reactor 1 from top to bottom, and are connected to the main air pipe 11 through a four-way pipe; (in the specific implementation, at least one layer of branch air pipes connected to the main air pipe can be arranged according to the height of the reactor); a plurality of through-going air outlets are arranged at the bottom of the branch air pipe 12; the main air pipe 11 and the branch air pipe 12 together constitute a blast system, and the service area of ​​a single air outlet is 0.4m 2 .

[0036] like Figure 3 As shown, a single-layer water distribution pipe 17 is arranged at the top of the reactor 1, and is composed of a water inlet main pipe 13 and a plurality of water distribution branches 14. The water distribution branches 14 are evenly distributed around the water inlet main pipe 13 in a radial shape (six water distribution branches 14 are arranged in this embodiment. In a specific implementation, the number of water distribution branches can be adjusted according to the cross-sectional area of ​​the reactor 1); one end of the water inlet main pipe 13 passes through the water inlet provided on the upper surface of the reactor 1 and is connected to the water inlet pipe 5, and the other end is connected to the water distribution branch 14; a through water inlet opening 15 is provided on the bottom surface of the water distribution branch 14; in this embodiment, the flow rate range of the water inlet main pipe 13 is 3-5m / h, and all the water inlet openings 15 of the water distribution branch 14 can quickly discharge water, and the flow rate thereof is less than the flow rate of the water inlet main pipe 13;

[0037] like Figure 5As shown, the lower surface of the water distribution manifold 14 is provided with a water inlet opening 15 and a louver 16. Figure 6 As shown, the shutter 16 includes a door leaf 22, a small door shaft 18 and a large door shaft 21, which form a horizontal shutter water control system; the door leaf 22 is an iron sheet with a plurality of small holes at intervals, the shape of the small holes matches the water inlet opening 15, and iron small door shafts 18 are provided at both ends of each small hole, and a large door shaft 21 is also provided at the door leaf 22 radially close to the inner wall of the reactor 1. The shutter 16 can be controlled by a valve arranged outside the water distribution manifold 14 so as to move forward and backward along the lower surface of the water distribution manifold 14, thereby increasing or decreasing the effective water flow area of ​​the water inlet opening 15. When the water volume is small, the inlet water flows out from the water inlet opening 15 closer to the water inlet main pipe 13. At this time, the shutter can be moved forward to reduce the effective water flow area of ​​the opening, so that the inlet water can flow out from the water inlet opening 15 farther from the water inlet main pipe, thereby enhancing the water distribution effect. When the water inflow increases, the shutter can be moved backward to increase the effective water flow area of ​​the water inlet opening 15 and reduce the water flow speed.

[0038] In this embodiment, the aperture of the water inlet opening 15 gradually increases from the axis to the edge, that is, the aperture of the water inlet opening 15 closer to the water inlet main pipe 13 is smaller, and the aperture of the water inlet opening 15 closer to the reaction tank 1 is larger, so as to ensure that water flows out evenly from all holes.

[0039] The water distribution plate 19 is a circular ring structure fixedly arranged on the inner wall of the reactor 1 and is located below the water distribution pipe 17 (i.e., between the water distribution pipe 17 and the filler). The outer diameter of the water distribution plate 19 matches the cross-sectional diameter of the reactor 1; Figure 4 As shown, in this embodiment, the annular water distribution plate 19 is composed of 6 sectors of the same area to facilitate assembly and disassembly. The outer diameter of the ring is the same as the inner diameter of the reactor 1. The circular channel in the center of the water distribution plate is used to check the water distribution situation. The surface of the water distribution plate 19 is provided with a plurality of through water distribution openings 20. The sludge-containing wastewater flowing out of the water distribution pipe 17 at a high speed passes through the filler evenly under the further water distribution action of the water distribution plate 19.

[0040] The application method of the above-mentioned filtration and leaching filler film-forming device is as follows:

[0041] The sludge in this embodiment was directly taken from an aerobic tank of a sewage treatment plant in Nanjing, with a sludge concentration of 7400 mg / L without other treatment; the concentrated wastewater storage tank had a volume of 50 L, and the concentrated wastewater in the tank was wastewater containing high concentrations of carbon and nitrogen sources (including sodium acetate concentration of 40 g / L and ammonium chloride concentration of 3 g / L).

[0042] 1) The sludge in the sludge stirring tank 2 is uniformly fluidized in the tank under the action of the agitator 3, and enters the reactor 1 from the water inlet pipe 5 through the action of the water inlet pump 4. The sewage in the reactor 1 passes through the filler (the filler used in this embodiment is polyurethane foam, purchased from Jiangsu Aiqin Environmental Protection Technology Co., Ltd.) at a high flow rate. The filler intercepts the sludge in the sludge liquid, and the effluent returns to the sludge stirring tank 2 through the drain pipe 6. After repeating this process several times, the effluent from the drain pipe 6 gradually becomes clear.

[0043] 2) The sludge mixing tank 2 is equipped with an online water quality monitoring system (CODmax II potassium dichromate method COD detector, Hach and Amtax sc ammonia nitrogen online monitor, Hach, both are conventional monitoring systems). When the COD and ammonia nitrogen concentrations in the sewage are low, the concentrated sewage can be pumped into the concentrated wastewater storage tank 7 by controlling the sampling pump 8 to keep the nutrient concentration of the wastewater in the entire system in the sludge mixing tank 2 stable.

[0044] 3) When the sewage in the sludge mixing tank is basically clear, the biofilm formation is completed, and the sludge discharge device is opened through the valve to discharge the sewage in the reactor 1 and the sludge mixing tank 2. When there is sludge accumulation at the bottom of the reactor 1 during the biofilm formation process, the sludge discharge device of the reactor 1 can be opened separately to discharge the sludge into the sludge mixing tank 2 for recirculation.

[0045] 4) During operation, air is first discharged into the main air pipe 11 by the blower 10, and then diverted to the diverter air pipe 12 through the four-way diverter, and then discharged from the air outlet, so that the reactor 1 has sufficient oxygen at different heights. Since the air outlets on the diverter air pipe are evenly distributed on the cross-sections of the reactor 1 at different heights, it can ensure that the oxygen at different positions of the reactor 1 is evenly distributed. This ventilation process can ensure that the biofilm on the surface of the filler is in a fully aerobic environment during the biofilm formation process, thereby accelerating the metabolism of microorganisms.

[0046] Through the above steps, microbial biofilm formation can be completed quickly, 3 to 5 days in summer (25℃) and 7 to 10 days in winter (10℃), which greatly shortens the biofilm formation time.

Claims

1. A leaching filler biofilm forming device, comprising a sludge stirring tank provided with a stirrer, characterized in that: A second sludge discharge device is provided at the bottom of the sludge stirring tank; the concentrated wastewater storage is connected to the sludge stirring tank through a pipeline provided with a sample feed pump, and the sludge stirring tank is connected to the water inlet provided at the top of the reactor through a water inlet pipe provided with a water inlet pump; The water outlet at the bottom of the reactor is connected to the sludge stirring tank through a drainage pipe; a first sludge discharge device connected to the sludge stirring tank is also provided at the bottom of the reactor; the main air pipe is arranged along the longitudinal axis of the reactor, one end of the main air pipe is connected to the blower arranged outside the reactor, and the other end is connected to at least one annular branch air pipe through a four-way pipe; the branch air pipe is arranged circumferentially along the inner wall of the reactor, and a plurality of through air outlets are provided at the bottom of the branch air pipe, and the service area of ​​the air outlet meets 0.4-0.8m 2 / indivual; The water distribution pipe is arranged at the top of the reactor, and is composed of a water inlet main pipe and a plurality of water distribution branches; the water distribution branches are evenly arranged around the water inlet main pipe in a radial shape; one end of the water inlet main pipe is connected to the water inlet pipe, and the other end is connected to the water distribution branches; a plurality of through water inlet openings are arranged on the bottom surface of the water distribution branches; the aperture of the water inlet openings gradually increases from the axis to the edge; The bottom surface of the water distribution manifold is also provided with a shutter; the shutter is composed of a door leaf, a small door shaft and a large door shaft; the door leaf is an iron sheet with a number of small holes at intervals, the shape of the small holes matches the water inlet opening, each small hole is provided with an iron small door shaft at both ends, and a large door shaft is provided at the radial position of the door leaf close to the reactor; A circular water distribution plate is arranged below the water distribution pipe. The outer diameter of the water distribution plate matches the cross-sectional diameter of the reactor. A plurality of through water distribution openings are arranged on the surface of the water distribution plate.

2. The leaching filler biofilm forming device according to claim 1, characterized in that: The reactor is a cylindrical structure.

3. The leaching filler biofilm forming device according to claim 1, characterized in that: The water distribution plate is composed of a plurality of fan-shaped structures.

4. A biofilm forming method using a biofilm forming device using a leaching method as claimed in any one of claims 1 to 3, wherein the specific steps are as follows: 1) Place the sludge from the aerobic tank of the sewage treatment plant in the sludge mixing tank, turn on the agitator, and evenly fluidize the sludge in the sludge mixing tank; then turn on the water inlet pump, and the sewage in the sludge mixing tank enters the reactor through the water inlet pipe, and then passes through the filler through the water inlet main pipe and the water distribution branch, and finally returns to the sludge mixing tank through the drainage pipe. When the COD and ammonia nitrogen concentrations in the sewage in the sludge mixing tank are low, the concentrated sewage is pumped into the concentrated sewage storage tank through the sampling pump; 2) When the sewage in the sludge mixing tank is clarified, open the second sludge discharge device and the second sludge discharge device to discharge the sewage in the reactor and the sludge mixing tank; 3) Turn on the blower at the same time, and the air enters the branch air pipe through the main air pipe and is discharged from the exhaust hole; 4) When there is sludge accumulation at the bottom of the reactor, open the first sludge discharge device and discharge the sludge into the sludge mixing tank for recirculation; repeat this process several times to complete the biofilm formation of microorganisms on the surface of the filler.

5. The method according to claim 4, characterized in that The flow rate of the water inlet main pipe ranges from 3 to 5 m / h.

Images