Aquaculture tail water treatment system

Abstract

The invention discloses an aquaculture tail water treatment system, which relates to the technical field of wastewater treatment and comprises an adjusting tank, air flotation equipment, a biological membrane tank, a sludge tank and dehydration equipment, the adjusting tank is used for homogenizing and equalizing aquaculture tail water, and the bottom of the adjusting tank is connected and communicated with the air flotation equipment through a pipeline; a pipeline for conveying aquaculture tail water subjected to air floatation is connected between the air floatation equipment and the biological membrane tank, and a pipeline for conveying air floatation sludge is connected between the air floatation equipment and the sludge tank; a pipeline for conveying an aged biological membrane is connected between the biological membrane tank and the sludge tank; a pipeline for conveying sludge is connected between the sludge tank and the dewatering equipment, and dewatered clear liquid obtained by the dewatering equipment can be sent back to the regulating tank. The treatment effect on the aquaculture tail water can be effectively improved, and therefore pollution of aquaculture tail water discharge to the environment can be effectively reduced.

Description

Technical Field

[0001] The present application relates to the technical field of wastewater treatment, and in particular to an aquaculture tailwater treatment system. Background Art

[0002] Aquaculture tail water is the water discharged during the aquaculture process after the water quality changes due to factors such as the metabolism of farmed animals, feed residues, drug use, and various biological activities in the water body.

[0003] At present, the tail water produced during the aquaculture process (such as eel) contains a large amount of organic matter and pollutants such as nitrogen and phosphorus. Among them, phosphorus mainly exists in suspended matter such as excrement and residual food, while nitrogen is mainly nitrate nitrogen and a small amount of ammonia nitrogen. Therefore, if the tail water of aquaculture is discharged directly without treatment, it will cause pollution to the surrounding environment.

[0004] Traditionally, aquaculture effluent is treated by sedimentation and filtration. During the treatment process, the remaining bait and excrement in the effluent are precipitated (sedimentation tank) and filtered (such as filter dam or biofilm treatment), and the filtered wastewater is directly discharged.

[0005] However, after being treated by traditional methods, aquaculture tailwater usually still contains high levels of organic matter and pollutants such as nitrogen and phosphorus. In addition, the concentration of pollutants in factory aquaculture tailwater is even higher. Since 2023, various parts of the country have issued their own "Aquaculture Tailwater Discharge Standards", requiring that the effluent COD, total nitrogen and total phosphorus are usually within 10mg / L, 3mg / L and 0.5mg / L. Therefore, there is an urgent need for an aquaculture tailwater treatment system with better treatment effects. Summary of the invention

[0006] The present application provides an aquaculture tailwater treatment system, which can effectively improve the treatment effect of aquaculture tailwater, thereby effectively reducing the pollution of aquaculture tailwater discharge to the environment.

[0007] The present application provides an aquaculture tailwater treatment system, which adopts the following technical solution: An aquaculture tailwater treatment system, comprising a regulating tank, an air flotation device, a biofilm tank, a sludge tank and a dehydration device; The regulating pond is used for homogenizing and balancing the tail water of aquaculture, and the bottom of the regulating pond is connected to the air flotation equipment through a pipeline; A pipeline for conveying aquaculture tail water after air flotation is connected between the air flotation equipment and the biofilm pool, and a pipeline for conveying air flotation sludge is connected between the air flotation equipment and the sludge pool; A pipeline for conveying aged biofilm is connected between the biofilm pool and the sludge pool; a pipeline for conveying sludge is connected between the sludge pool and the dehydration equipment, and the dehydrated clear liquid obtained by the dehydration equipment can be sent back to the regulating pool.

[0008] By adopting the above technical scheme, after the aquaculture tail water is allowed to settle, the wastewater with a high pollutant concentration is subjected to flotation treatment to remove most of the suspended solids and pollutants such as total phosphorus in the wastewater; the wastewater is then used to remove pollutants such as organic matter, ammonia nitrogen, total nitrogen and total phosphorus in the biofilm tank; and the flotation sludge and biofilm will be treated together in the sludge tank, and then dehydrated by the dehydration equipment to obtain mud cake and dehydrated clear liquid, and the dehydrated clear liquid can be sent back to the regulating tank to continue to participate in the aquaculture tail water treatment; it can effectively improve the treatment effect of aquaculture tail water, and at the same time, it can properly treat the substances obtained after the aquaculture tail water treatment, thereby effectively reducing the pollution of aquaculture tail water discharge to the environment.

[0009] Optionally, the biofilm pool includes a primary A1 pool, a primary A2 pool, a primary O pool, a secondary A pool and a secondary O pool which are sequentially distributed along the flow direction of the sewage, and each pool is provided with fillers for microorganisms to attach and grow; The bottom between the primary A1 pool and the primary A2 pool has a first communication port, the top between the primary A2 pool and the primary O pool has a first overflow port, the bottom between the primary O pool and the secondary A pool has a second communication port, and the top between the secondary A pool and the secondary O pool has a second overflow port; Aeration devices are provided in both the primary O2 tank and the secondary O2 tank.

[0010] By adopting the above technical solution, microorganisms can attach and grow on the filler to form a biofilm, and stay in their respective corresponding pools, effectively reducing the probability of microorganisms flowing with sewage to the next pool, thereby effectively ensuring the species differentiation of microorganisms in aerobic pools and anoxic pools, and making the proportion of effective dominant microbial species in each pool high, thereby significantly improving the nitrification performance of the O pool and the denitrification capacity of the A pool, so that the treatment effect of sewage in the biofilm pool is further improved.

[0011] Optionally, the primary A1 pool, the primary A2 pool, the primary O pool, the secondary A pool and the secondary O pool are all provided with a desludging device; The mud removal device includes a mud sucker and a mud guard; the mud sucker includes a mud suction pipe and a mud suction pump; one end of the mud suction pipe is connected to the sludge pool and is located in a corner of the pool, and the other end is immersed in the liquid and close to the liquid surface; the mud suction pump is arranged on the mud suction pipe, and can drive the biofilm located on the liquid surface in the pool to be sent into the sludge pool through the mud suction pipe; The mud guard is arranged in the pool, with part of the mud guard being located above the liquid surface and part of the mud guard being immersed in the liquid, and is located on one side of the end of the mud suction pipe along the flow direction of sewage in the pool.

[0012] By adopting the above technical solution, the mud removal device can timely discharge the aged biofilm that has separated from the filler, thereby effectively improving the purity of the sewage in the biofilm pool, and further improving the water quality obtained after the biofilm pool treats the sewage.

[0013] Optionally, the mud suction device further includes a movable tube and a floating member; The movable tube is movably connected to the end of the sludge suction tube in the pool, the movable tube is movable in a vertical direction, and the movable tube is kept in communication with the sludge suction tube during the movement; The top of the movable tube is provided with a mud suction port, and the floating member is arranged on the top of the movable tube; the floating member floats on the liquid surface, so that the position of the mud suction port is kept not higher than the liquid surface, and the biofilm floating on the liquid surface can enter the mud suction port.

[0014] By adopting the above technical solution, the sludge absorber can conveniently remove the biofilm floating on the liquid surface according to the liquid level in the pool, and at the same time can reduce the liquid discharged through the sludge absorber along with the sludge, thereby effectively improving the sludge suction effect of the sludge absorber.

[0015] Optionally, the fender is provided with a plurality of filter holes for filtering biofilm.

[0016] By adopting the above technical solution, the mud guard can achieve the effect of intercepting the biofilm while reducing its influence on the flow of sewage in the pool.

[0017] Optionally, the fender is an arc-shaped plate structure, and the axis of the arc track of the fender is vertical.

[0018] By adopting the above technical solution, the arc-shaped concave space of the fender can provide a larger retention space for the biofilm intercepted by it, thereby effectively improving the interception effect of the fender on the biofilm.

[0019] Optionally, the filter hole is tapered toward the direction approaching the mud suction pipe.

[0020] By adopting the above technical solution, during the operation of the sludge suction device, the sewage in the pool can be affected by it and flow through the filter holes, thereby effectively driving the biofilm intercepted by the mud guard to move in the direction close to the sludge suction port, and at the same time, it can clear the filter holes and reduce the probability of the biofilm clogging the filter holes.

[0021] Optionally, the mud removal device further includes a driving member; One end of the mudguard arc track is rotatably connected to the pool body, and the rotation axis of the mudguard is vertical; the driving member is arranged on the pool body and can drive the mudguard to rotate; When the mud guard is rotated to the extreme position in the direction away from the mud suction pipe, the mud guard and the pool wall of the mud suction pipe on the side away from the mud guard are expanded along the flow direction of the sewage in the pool; When the mud guard plate rotates to the extreme position in the direction close to the mud suction pipe, the mud guard plate and the pool wall of the mud suction pipe on the side away from the mud guard plate are in a contracted shape along the flow direction of sewage in the pool.

[0022] By adopting the above technical solution, when the mud suction device is not in operation, the mud guard mainly intercepts the biofilm, and at the same time, a larger interception area is provided for the biofilm to stay around the mud suction port; when the mud suction device is in operation, the rotation of the mud guard can gather the biofilm intercepted by it, so as to facilitate the subsequent discharge of the biofilm through the mud suction device.

[0023] Optionally, a plurality of flow promoters are provided in the primary A1 pool, the primary A2 pool and the secondary A pool; The flow promoter is close to the bottom of the pool body, and a plurality of the flow promoters can drive the sewage to flow along a circular trajectory in the pool.

[0024] By adopting the above technical solution, the flow promoter can promote the flow of sewage in the pool, thereby promoting the contact between sewage and microorganisms on the filler, and further improving the treatment effect of the biofilm pool on sewage.

[0025] Optionally, a plurality of guide plates are further provided in the first-level A1 pool, and a plurality of the guide plates are separated in the pool to form a plurality of flow channels.

[0026] By adopting the above technical solution, the intensity of the flow of sewage just entering the biofilm pool can be further increased, the efficiency of the reaction between sewage and microorganisms can be further improved, and at the same time, the probability of pollutants in the sewage precipitating and accumulating in the first pool, which may affect the overall sewage treatment effect of the biofilm pool, can be reduced.

[0027] In summary, the present application includes at least one of the following beneficial effects: 1. It can effectively improve the treatment effect of aquaculture tail water, and at the same time, it can properly treat the substances obtained after the treatment of aquaculture tail water, thereby effectively reducing the pollution of aquaculture tail water discharge to the environment; 2. It can effectively ensure the species differentiation of microorganisms in aerobic pools and anoxic pools, thereby improving the treatment effect of biofilm pools on sewage, and further improving the treatment effect of the overall treatment system on aquaculture wastewater; 3. It can improve the effect of the desludging device on removing the biofilm separated from the filler in the biofilm pool, thereby effectively improving the water quality obtained after the biofilm pool treats sewage; 4. It can improve the efficiency of the mud removal device in removing the biofilm that has separated from the filler in the biofilm pool, and reduce the probability of sewage being discharged together with the biofilm. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the overall structure of an aquaculture tailwater treatment system in Example 1; Figure 2 is a schematic diagram of the local structure when the biofilm pool is arranged along a straight line in Example 1 (the guide plate is omitted); Figure 3 It is a schematic diagram of the local structure when the biofilm pool is arranged along a straight line in Example 1 (fillers omitted); Figure 4 It is a schematic diagram of the partial structure of the mud removal device in Example 1; Figure 5 It is a schematic diagram of the partial structure of the mud removal device in Example 2; Figure 6 is a partial cross-sectional view of the mud suction device in Example 2; Figure 7 is a partial cross-sectional view of the mud removal device in Example 2 when mud removal is not performed; Figure 8 It is a partial cross-sectional view of the mud removal device in Example 2 when removing mud.

[0029] Explanation of the reference numerals: 1. regulating tank; 2. flotation equipment; 3. biofilm tank; 31. primary A1 tank; 32. primary A2 tank; 33. primary O tank; 34. secondary A tank; 35. secondary O tank; 36. flow promoter; 37. guide plate; 38. filler; 39. aeration device; 4. sludge tank; 5. dehydration equipment; 6. dosing equipment; 7. metering pump; 8. mud removal device; 81. mud suction device; 811. mud suction pipe; 812. mud suction pump; 813. movable pipe; 8131. mud suction port; 814. floating part; 82. mud guard; 821. filter hole; 83. driving part; 9. pump body; 101. first connecting port; 102. first overflow port; 103. second connecting port; 104. second overflow port. DETAILED DESCRIPTION

[0030] The following is combined with Figure 1-8 This application is described in further detail.

[0031] Embodiment 1: The embodiment of the present application discloses an aquaculture tailwater treatment system, which is used to treat aquaculture tailwater (such as eel) so that the discharged wastewater meets the standards, thereby effectively reducing the pollution of the surrounding environment by the wastewater discharge.

[0032] Reference Figure 1 and Figure 2 The aquaculture tailwater treatment system includes a regulating tank 1, an air flotation device 2, a biofilm tank 3, a sludge tank 4 and a dewatering device 5. Among them, the regulating tank 1 is used to homogenize and equalize the tailwater of aquaculture, so as to facilitate the subsequent treatment of sewage with concentrated pollutants; the air flotation device 2 is used to pre-treat the tailwater of aquaculture, and can remove most of the suspended matter and total phosphorus and other pollutants in the sewage; the biofilm tank 3 is used to treat the pollutants in the sewage through microorganisms, and can remove organic matter, ammonia nitrogen, total nitrogen and total phosphorus and other pollutants in the sewage; the sludge tank 4 is used to gather the air flotation sludge, biological sludge (i.e., biofilm) and other sludges generated in the process of aquaculture tailwater treatment, so as to facilitate the subsequent unified treatment; the dewatering device 5 is used to treat the sludge in the sludge tank 4 to obtain mud cake and dewatered clear liquid, so as to facilitate the transportation of the mud cake for treatment, and reuse the dewatered clear liquid in the process of aquaculture tailwater treatment.

[0033] The top of the regulating pool 1 is connected to a pipeline for conveying the aquaculture tail water into the regulating pool 1; the regulating pool 1 and the air flotation device 2 are connected through a pipeline, the pipeline is connected to the bottom of the regulating pool 1, and a pump body 9 is fixedly installed on the pipeline to drive the aquaculture tail water in the regulating pool 1 into the air flotation device 2. In this embodiment, since the regulating pool 1 with the above functions and the corresponding pump body 9 are both existing technologies in the field, they are not described here in detail, and they are only briefly shown in the drawings.

[0034] The flotation device 2 is externally connected to two pipes which are connected to the biofilm pool 3 and the sludge pool 4 respectively, and are used to drive the flotation effluent and the flotation sludge obtained after the sewage is pre-treated by flotation into the biofilm pool 3 and the sludge pool 4 respectively, and the flotation effluent and the flotation sludge are transported through the pipes by gravity. In this embodiment, since the flotation device 2 with the above functions is a prior art in the art, it will not be described here in detail, and it is only briefly shown in the drawings.

[0035] The air flotation device 2 is also connected to an external pipeline connected to a dosing device 6 for replenishing PAC / PAM (polyaluminium chloride / polyacrylamide) into the air flotation device 2, and a metering pump 7 is fixedly installed on the pipeline for replenishing PAC / PAM into the air flotation device 2 in a timely and quantitative manner according to demand. In this embodiment, since the dosing device 6 and the metering pump 7 with the above functions are both existing technologies in the field, they are not described here in detail, and they are only briefly shown in the drawings.

[0036] Reference Figure 2 and Figure 3 The biofilm pool 3 includes a primary A1 pool 31, a primary A2 pool 32, a primary O pool 33, a secondary A pool 34 and a secondary O pool 35 which are sequentially arranged along the flow direction of the sewage. The flotation effluent obtained by the operation of the flotation device 2 will flow into the primary A1 pool 31 through a pipeline, and the pipeline is connected to the space above the liquid surface of the primary A1 pool 31. In this embodiment, the arrangement direction of the primary A1 pool 31, the primary A2 pool 32, the primary O pool 33, the secondary A pool 34 and the secondary O pool 35 is not further set. In actual applications, they are usually arranged along a straight trajectory or along a circular trajectory.

[0037] A first connecting port 101 for sewage circulation is provided at the bottom between the primary A1 pool 31 and the primary A2 pool 32, so that the sewage liquid levels in the primary A1 pool 31 and the primary A2 pool 32 are flush; a first overflow port 102 is provided at the top between the primary A2 pool and the primary O pool 33 for sewage circulation, and the sewage liquid level in the primary O pool 33 will be lower than the sewage liquid level in the primary A2 pool; a second connecting port 103 is provided at the bottom between the primary O pool 33 and the secondary A pool 34 for sewage circulation, so that the sewage liquid levels in the primary O pool 33 and the secondary A pool 34 are flush; a second overflow port 104 is provided at the top between the secondary A pool 34 and the secondary O pool 35 for sewage circulation, and the sewage liquid level in the secondary O pool 35 will be lower than the sewage liquid level in the secondary A pool 34.

[0038] During the treatment of sewage in the biofilm pool 3, the nitrate in the sewage is first removed by the denitrification capacity of the primary A1 pool 31 and the primary A2 pool 32, and then a small amount of ammonia nitrogen in the sewage is converted into nitrate in the primary O pool 33. Then, a small amount of nitrate formed by nitrification of the sewage in the primary O pool 33 is removed in the secondary A pool 34. Finally, the residual organic matter in the sewage is further removed in the secondary O pool 35, and the total phosphorus is adsorbed by the biofilm, thereby achieving the effects of nitrogen removal, phosphorus removal and carbon removal.

[0039] In this embodiment, the preferred sewage treatment time in the primary A1 pool 31, the primary A2 pool 32, the primary O pool 33, the secondary A pool 34 and the secondary O pool 35 is 5h, 5h, 5h, 3h and 4h respectively.

[0040] After the sewage in the secondary A pool 34 meets the standards, it can be directly discharged through pipelines or transported back to the parts of the aquaculture system that need water for use.

[0041] The first-level A1 pool 31, the first-level A2 pool 32, the first-level O pool 33, the second-level A pool 34 and the second-level O pool 35 are all fixedly installed with fillers 38 for microorganisms to attach and grow. The microorganisms form biofilms on the fillers 38, and the fillers 38 are mainly located in the middle area of ​​the sewage in the pool, that is, the position of the fillers 38 is higher than the first connecting port 101 and the second connecting port 103 and lower than the first overflow port 102 and the second overflow port 104, so that the fillers 38 can remain immersed in the sewage, which is convenient for the sewage to contact and react with the biofilm on the fillers 38. In this embodiment, the fillers 38 are preferably biological rope fillers 38, elastic fillers 38 or combined fillers 38; since the fillers 38 with the above functions are the prior art in the art, they are not described here in detail, and are only briefly shown in the drawings.

[0042] The primary A1 pool 31, the primary A2 pool 32 and the secondary A pool 34 are all connected to a pipe connected to a dosing device 6 for replenishing a carbon source (such as methanol, sodium acetate or glucose, etc.) into the pool, and the dosing device 6 is equipped with a device for replenishing the carbon source into the pool in a timely and quantitative manner according to demand. In this embodiment, since the dosing device 6 and the metering pump 7 with the above functions are both existing technologies in the field, they are not described here, and they are only briefly shown in the drawings.

[0043] In addition, the primary A1 pool 31, the primary A2 pool 32 and the secondary A pool 34 are also equipped with instruments capable of online measuring the ORP (oxidation-reduction potential) value and pH value (acid-base value) in the sewage, so that the staff can know in real time the treatment status of the sewage in the primary A1 pool 31, the primary A2 pool 32 and the secondary A pool 34. In this embodiment, it is preferred that the ORP value in the primary A1 pool 31, the primary A2 pool 32 and the secondary A pool 34 is maintained within the range of -80-20mV and the pH is maintained within the range of 7.0-8.5; since the instrument with the above functions is the prior art in the art, it will not be described in detail here, and it is omitted in the drawings.

[0044] The primary O2 tank 33 and the secondary O2 tank 35 are both equipped with an aeration device 39, which aerates the sewage near the bottom of the tank to facilitate the reaction between the microorganisms in the tank and the sewage. In this embodiment, the aeration device 39 is preferably composed of a fan and a pipe for ventilation; since the aeration device 39 is a prior art in the art, it will not be described here, and it is only briefly shown in the drawings.

[0045] In addition, both the primary O2 tank 33 and the secondary O2 tank 35 are equipped with instruments capable of online measurement of dissolved oxygen, so that the staff can know in real time the treatment status of the sewage in the primary O2 tank 33 and the secondary O2 tank 35. In this embodiment, it is preferred that the dissolved oxygen content in the primary O2 tank 33 and the secondary O2 tank 35 is maintained within the range of 2-4 mg / L; since the instruments with the above functions are prior art in the art, they are not described in detail here, and are omitted in the drawings.

[0046] In order to promote the biofilm contact reaction between sewage and the filler 38 in the pool, preferably, a plurality of flow propelling devices 36 are installed in the first-level A1 pool 31, the first-level A2 pool 32 and the second-level A pool 34 to promote the intensity of sewage flowing in the pool. The flow propelling device 36 is close to the bottom of the pool body in the pool, and can drive the sewage to flow in a specified direction. The combined effect of a plurality of flow propelling devices 36 can drive the sewage in the pool to flow along the required trajectory. In the present embodiment, since the flow propelling device 36 is the prior art of this area, it is not described here, and it is only briefly represented in the accompanying drawings.

[0047] Two guide plates 37 are also fixedly installed in the first-level A1 pool 31. The two guide plates 37 are vertically arranged and parallel to each other, and three flow channels for sewage to flow through are separated in the pool. In this embodiment, preferably, three flow pushers 36 are installed in the first-level A1 pool 31, and the three flow pushers 36 are respectively located at the ends of the three flow channels, so that the sewage in the pool can circulate around the two guide plates 37, and the flow direction of the sewage between the two guide plates 37 is toward the first-level A2 pool.

[0048] In this embodiment, it is preferred that two flow producers 36 are installed in both the primary A2 pool and the secondary A pool 34, and the two flow producers 36 are respectively located at diagonal positions in the pool, so that the sewage in the pool can circulate in a circular trajectory, and during the flow of sewage, the sewage close to the primary O pool 33 or the secondary O pool 35 can overflow into the corresponding primary O pool 33 or the secondary O pool 35.

[0049] During the treatment of sewage in the primary A1 pool 31, the primary A2 pool 32, the primary O pool 33, the secondary A pool 34 and the secondary O pool 35, the biofilm on the surface of the filler 38 will fall off, and the fallen biofilm will float on the liquid surface, affecting the water quality of the sewage flowing to the next pool. At the same time, microorganisms will multiply and continue to attach to the surface of the filler 38 to maintain the treatment effect of the biofilm in the pool on the sewage.

[0050] Reference Figure 2 and Figure 4Therefore, a plurality of mud removal devices 8 for removing biofilms floating on the liquid surface in the pool are installed in the primary A1 pool 31, the primary A2 pool 32, the primary O pool 33, the secondary A pool 34 and the secondary O pool 35. In this embodiment, preferably, a mud removal device 8 is installed in each of the primary A1 pool 31, the primary A2 pool 32, the primary O pool 33, the secondary A pool 34 and the secondary O pool 35. The mud removal device 8 is located in a corner of the pool body, and the sewage can flow around the mud removal device 8 during the flow in the pool.

[0051] Reference Figure 3 and Figure 4 The mud removal device 8 includes a mud sucker 81 and a mud guard 82. The mud sucker 81 is used to suck the biofilm floating on the liquid surface in the pool and discharge it; the mud guard 82 is used to intercept the biofilm floating on the liquid surface in the pool during the flow of sewage in the pool, so that the biofilm floating on the liquid surface in the pool can be concentrated around the mud sucker 81.

[0052] Reference Figure 2 and Figure 4 The mud suction device 81 includes a mud suction pipe 811 and a mud suction pump 812 .

[0053] One end of the sludge suction pipe 811 is immersed in the sewage in the pool and is located near the liquid surface, and the other end of the sludge suction pipe 811 is connected to the sludge pool 4. In this embodiment, it is preferred that the end of the sludge suction pipe 811 located in the pool has a vertically upward expansion structure, and the sludge suction pipe 811 can suck the biofilm floating on the liquid surface in the pool above it and discharge it into the sludge pool 4; and it is preferred that the position where the sludge suction pipe 811 sucks the biofilm is 5-10 cm below the liquid surface.

[0054] The sludge suction pump 812 is fixedly mounted on the sludge suction pipe 811, and can drive the biofilm located around the sludge suction pipe 811 in the pool to be transported into the sludge pool 4 through the sludge suction pipe 811. In this embodiment, the sludge suction pump 812 can be automatically turned on for 3-10 minutes every 0.5-3 hours according to the operation of the biofilm to remove the biofilm floating on the liquid surface in the pool; since the sludge suction pump 812 with the above function is a prior art in the art, it will not be described in detail here, and it is only briefly shown in the attached drawings.

[0055] The mud guard 82 is a rectangular plate-shaped structure as a whole. The mud guard 82 is fixedly installed on one side of the pool body, located on the side of the end of the mud suction pipe 811 in the pool along the flow direction of the sewage in the pool, and its two ends in the length direction are respectively located above the sewage in the pool and in the sewage; a space for biofilm to gather is formed between the mud guard 82 and the pool wall on the side of the mud suction pipe 811 on the pool body away from the mud guard 82, and the space is in a constricted shape along the flow direction of the sewage in the pool. The biofilm floating on the liquid surface in the pool will enter the above space and contact the mud guard 82 along with the flow of the sewage in the pool. The mud guard 82 can intercept the biofilm in contact with it, so that the biofilm floating on the liquid surface is concentrated in the area near the mud suction pipe 811, so that the biofilm floating on the liquid surface in the pool can be sucked and discharged when the mud suction device 81 is running. In this embodiment, the length of the part of the mud guard 82 located above the liquid surface in the pool is preferably 5 cm, and the length of the part of the mud guard 82 located in the sewage in the pool is 10-20 cm.

[0056] Reference Figure 1 , the sludge pool 4 is connected to the dewatering device 5 by a pipeline, and a pump body 9 is fixedly installed on the pipeline; after the air flotation sludge generated by the operation of the air flotation device 2 and the biological sludge (i.e., biofilm) generated by the operation of the biofilm pool 3 are transported to the sludge pool 4, when the sludge storage volume in the sludge pool 4 reaches a certain value, the pump body 9 will drive the sludge in the sludge pool 4 to be transported to the dewatering device 5. In this embodiment, the dewatering device 5 is preferably a screw stack dewatering machine; since the screw stack dewatering machine is a prior art in the art, it will not be described in detail here, and it is only briefly shown in the drawings.

[0057] After the dewatering equipment 5 dehydrates the sludge, mud cake and dewatered clear liquid will be obtained, wherein the mud cake will be sent out by a special transport vehicle for subsequent treatment, and the dewatered clear liquid will be sent back to the regulating tank 1 through a pipeline for further treatment.

[0058] The implementation principle of an aquaculture tailwater treatment system in the embodiment of the present application is: After the aquaculture tail water is homogenized and weighed in the regulating tank 1, the sewage with uniform pollutants is sent to the flotation equipment 2 for flotation treatment. The flotation sludge obtained after the flotation treatment is sent to the sludge tank 4, and the flotation effluent is sent to the biofilm tank 3 to remove organic matter, nitrogen, phosphorus and other pollutants in the sewage in the biofilm tank 3. The biofilm tank 3 treats the sewage to obtain sewage that meets the standards and then discharges it. The mud removal device 8 absorbs the aged biofilm detached from the filler 38 during the operation of the biofilm tank 3 and discharges it into the sludge tank 4; when the sludge in the sludge tank 4 reaches a certain amount, the sludge in the sludge tank 4 will be sent to the dehydration equipment 5 for dehydration, and the mud cake obtained after the sludge dehydration is transported and sent out for separate treatment, and the obtained dehydrated clear liquid is sent back to the regulating tank 1 to continue to participate in the aquaculture tail water treatment.

[0059] Embodiment 2: Reference Figure 4 and Figure 5 The difference between this embodiment and embodiment 1 lies in the mud removal device 8.

[0060] Reference Figure 5 and Figure 6 In order to facilitate the sludge absorber 81 to suck the biofilm floating on the liquid surface in the pool, reduce the probability of sewage being discharged together with the biofilm through the sludge suction pipe 811, and improve the removal effect of the sludge removal device 8 on the biofilm, the sludge absorber 81 preferably also includes a movable pipe 813 and a floating part 814, and the end of the sludge suction pipe 811 located in the pool is preferably a circular tube structure.

[0061] One end of the movable tube 813 is sleeved and matched with the end of the mud suction tube 811 located in the pool and is movably connected with the mud suction tube 811. The movable direction of the movable tube 813 is vertical, and the movable tube 813 keeps sleeved and matched with the mud suction tube 811 during the movement.

[0062] The top of the movable pipe 813 has an upwardly flared structure and forms a mud suction port 8131 for the biofilm floating on the liquid surface in the pool to enter the movable pipe 813 . After the biofilm enters the movable pipe 813 through the mud suction port 8131 , it can enter the mud suction pipe 811 along the movable pipe 813 .

[0063] The floating member 814 has the effect of floating on the liquid surface, that is, the density of the floating member 814 is less than the density of the sewage. The floating member 814 is fixedly installed on the top of the movable tube 813 and is located at the position of the mud suction port 8131, so that the mud suction port 8131 can maintain a height not higher than the liquid surface in the sewage. At the same time, the floating member 814 reduces the area where the biofilm enters the inside of the movable tube 813 through the mud suction port 8131, so that the suction force of the mud suction device 81 on the biofilm is increased, and the suction effect on the biofilm is improved. In this embodiment, the preferred mud suction port 8131 will be kept at a position 1-3 cm below the liquid surface under the floating effect of the floating member 814.

[0064] Reference Figure 5 and Figure 7 In order to improve the interception effect of the mud guard 82 on the biofilm floating on the liquid surface in the pool, it is preferred that the mud guard 82 has an arc-shaped plate structure, the axis of the arc-shaped trajectory of the mud guard 82 is vertical, and the arc-shaped opening of the mud guard 82 faces the mud suction port 8131.

[0065] When the biofilm floating on the liquid surface in the pool contacts the fender 82 as the sewage in the pool flows, the biofilm will contact the arc-shaped concave surface of the fender 82. The arc-shaped concave surface structure of the fender 82 provides a larger space for the biofilm to stay, thereby allowing more biofilm to concentrate in the area near the mud suction port 8131.

[0066] Furthermore, in order to take into account the interception effect of the mud guard 82 on the biofilm floating on the liquid surface in the pool, and at the same time reduce the impact of the mud guard 82 on the flow of sewage in the pool, it is preferred that a plurality of filter holes 821 for filtering the biofilm are penetrated through the mud guard 82, and the plurality of filter holes 821 are evenly distributed on the mud guard 82.

[0067] When the biofilm floating on the liquid surface in the pool contacts the fender 82 along with the sewage flowing in the pool, the fender 82 can intercept the biofilm, and the sewage can pass through the fender 82 through the multiple filter holes 821.

[0068] Reference Figure 5 and Figure 8 Furthermore, in order to further improve the suction effect and efficiency of the biofilm floating on the liquid surface in the pool when the mud absorber 81 is in operation, the mud guard 82 is preferably rotatably connected to the pool body, and the mud removal device 8 also preferably includes a driving member 83 for driving the mud guard 82 to rotate.

[0069] One end of the arc track of the fender 82 is rotatably connected to the pool body, and the rotation axis of the fender 82 is vertical; the driving member 83 is fixedly mounted on the pool body, and can drive the fender 82 to rotate relative to the pool body. In this embodiment, the driving member 83 is preferably a servo motor; since the servo motor is a common prior art, it will not be described in detail here, and it is only briefly shown in the drawings.

[0070] The driving member 83 has a limit in driving the fender 82 to rotate.

[0071] Reference Figure 7 and Figure 8 When the fender 82 rotates to the extreme position in the direction away from the mud suction port 8131, the space formed between the fender 82 and the pool wall on the side of the mud suction pipe 811 on the pool body away from the fender 82 is in a constricted shape along the flow direction of the sewage in the pool, so that the biofilm intercepted by the fender 82 can stay in the area near the mud suction port 8131. Afterwards, when the mud guard 82 rotates to the extreme position in the direction close to the mud suction port 8131, the space formed between the mud guard and the pool wall on the side of the mud suction pipe 811 on the pool body away from the mud guard 82 is expanded along the flow direction of the sewage in the pool, which can have a gathering effect on the biofilm previously staying in the area near the mud suction port 8131, so that the biofilm is closer to the mud suction port 8131, and at the same time can reduce the influence of the sewage flow on the movement of the biofilm near the mud suction port 8131; and at this time, the mud sucker 81 has a suction effect on the sewage around the mud suction port 8131 during its operation, and the sewage moved by it can pass through the filter hole 821 in the reverse direction, which has a clearing effect on the filter hole 821 (the blockage is the biofilm), and at the same time can accelerate the biofilm gathered by the mud guard 82 to enter the mud suction port 8131.

[0072] Furthermore, in order to further improve the clearing effect of sewage flow on the filter hole 821 on the fender 82, the filter hole 821 is preferably tapered in the direction close to the axis of the arc trajectory of the fender 82, so as to facilitate the reverse flow of sewage through the filter hole 821 and through the fender 82.

[0073] The implementation principle of an aquaculture tailwater treatment system in the embodiment of the present application is: During the treatment of sewage in the biofilm pool 3, when the mud removal device 8 is in operation, the movable pipe 813 can move relative to the mud suction pipe 811 according to the height of the liquid level in the pool, so that the biofilm floating on the liquid surface in the pool can smoothly and quickly pass through the mud suction port 8131 into the mud suction pipe 811 and be discharged; At the same time, under the control of the driving member 83, the mud guard plate 82 can rotate to the extreme position and maintain it in the direction away from the mud suction port 8131 during the standby state of the mud removal device 8, so that more biofilms floating on the liquid surface in the pool will stay in the area near the mud suction port 8131; and before the mud removal device 8 is operated, the mud guard plate 82 can be rotated in the direction close to the mud suction port 8131, so that the biofilms staying in the area near the mud suction port 8131 will gather in the direction close to the mud suction port 8131, so as to facilitate the subsequent suction and discharge of the biofilms; during the operation of the mud removal device 8, the sewage flowing toward the mud suction port 8131 under the influence of the mud removal device 8 can pass through the filter hole 821, thereby clearing and blocking the filter hole 821, and at the same time, it can accelerate the entry of the biofilms around the mud suction port 8131 into the mud suction port 8131.

[0074] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. An aquaculture tailwater treatment system, characterized in that: It includes a regulating tank (1), an air flotation device (2), a biofilm tank (3), a sludge tank (4) and a dewatering device (5); The regulating pond (1) is used for homogenizing and balancing the quality and quantity of tail water from aquaculture, and the bottom of the regulating pond (1) is connected to the air flotation equipment (2) via a pipeline; A pipeline for conveying aquaculture tail water after air flotation is connected between the air flotation device (2) and the biofilm pool (3), and a pipeline for conveying air flotation sludge is connected between the air flotation device (2) and the sludge pool (4); A pipeline for conveying aged biofilm is connected between the biofilm tank (3) and the sludge tank (4); a pipeline for conveying sludge is connected between the sludge tank (4) and the dewatering device (5), and the dewatered clear liquid obtained by the dewatering device (5) can be sent back to the regulating tank (1).

2. The aquaculture tailwater treatment system according to claim 1, characterized in that: The biofilm pool (3) comprises a primary A1 pool (31), a primary A2 pool (32), a primary O pool (33), a secondary A pool (34) and a secondary O pool (35) which are sequentially distributed along the flow direction of the sewage, and each pool is provided with a filler (38) for microorganisms to attach and grow; The bottom between the primary A1 pool (31) and the primary A2 pool (32) has a first communication port (101), the top between the primary A2 pool (32) and the primary O pool (33) has a first overflow port (102), the bottom between the primary O pool (33) and the secondary A pool (34) has a second communication port (103), and the top between the secondary A pool (34) and the secondary O pool (35) has a second overflow port (104); Aeration devices (39) are provided in both the primary O tank (33) and the secondary O tank (35).

3. An aquaculture tailwater treatment system according to claim 2, characterized in that: The primary A1 pool (31), the primary A2 pool (32), the primary O pool (33), the secondary A pool (34) and the secondary O pool (35) are all provided with a desludging device (8); The mud removal device (8) comprises a mud sucker (81) and a mud guard (82); the mud sucker (81) comprises a mud suction pipe (811) and a mud suction pump (812); one end of the mud suction pipe (811) is connected to the sludge pool (4) and is located in a corner of the pool, and the other end is immersed in the liquid and close to the liquid surface; the mud suction pump (812) is arranged on the mud suction pipe (811) and can drive the biofilm located on the liquid surface in the pool to be sent into the sludge pool (4) through the mud suction pipe (811); The mud guard (82) is arranged in the pool, with part of the mud guard (82) located above the liquid surface and part of it immersed in the liquid, and is located on one side of the end of the mud suction pipe (811) along the flow direction of sewage in the pool.

4. The aquaculture tailwater treatment system according to claim 3, characterized in that: The mud suction device (81) further comprises a movable tube (813) and a floating member (814); The movable tube (813) is movably connected to the end of the mud suction tube (811) in the pool, the movable tube (813) is moved in a vertical direction, and the movable tube (813) remains in communication with the mud suction tube (811) during its movement; The top of the movable tube (813) is provided with a mud suction port (8131), and the floating member (814) is arranged on the top of the movable tube (813); the floating member (814) floats on the liquid surface, so that the position of the mud suction port (8131) is maintained not higher than the liquid surface, and the biofilm floating on the liquid surface can enter the mud suction port (8131).

5. The aquaculture tailwater treatment system according to claim 3, characterized in that: The fender (82) is provided with a plurality of filter holes (821) for filtering biofilms.

6. The aquaculture tailwater treatment system according to claim 5, characterized in that: The fender (82) is an arc-shaped plate structure, and the axis of the arc-shaped track of the fender (82) is vertical.

7. An aquaculture tailwater treatment system according to claim 6, characterized in that: The filter hole (821) is in a tapered shape towards the direction approaching the mud suction pipe (811).

8. The aquaculture tailwater treatment system according to claim 6, characterized in that: The mud removal device (8) further comprises a driving member (83); One end of the arc-shaped track of the fender (82) is rotatably connected to the pool body, and the rotation axis of the fender (82) is vertical; the driving member (83) is arranged on the pool body and can drive the fender (82) to rotate; When the mud guard (82) rotates to an extreme position in a direction away from the mud suction pipe (811), the mud guard (82) and the pool wall of the mud suction pipe (811) on the side away from the mud guard (82) are expanded along the flow direction of sewage in the pool; When the fender (82) rotates to an extreme position in a direction close to the sludge suction pipe (811), the fender (82) and the pool wall of the sludge suction pipe (811) on the side away from the fender (82) are in a constricted shape along the flow direction of sewage in the pool.

9. The aquaculture tailwater treatment system according to claim 3, characterized in that: The first-level A1 pool (31), the first-level A2 pool (32) and the second-level A pool (34) are each provided with a plurality of flow promoters (36); The flow promoter (36) is close to the bottom of the pool body, and a plurality of the flow promoters (36) can drive the sewage to flow along a circular trajectory in the pool.

10. The aquaculture tailwater treatment system according to claim 9, characterized in that: A plurality of guide plates (37) are also provided in the first-level A1 pool (31), and the guide plates (37) are separated in the pool to form a plurality of flow channels.

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