Efficient treatment method for aquaculture tail water

Abstract

The present invention relates to the technical field of aquaculture tailwater treatment, and discloses a highly efficient method for treating aquaculture tailwater, comprising: step 1: collecting aquaculture wastewater, and conveying the aquaculture tailwater from the sludge pool to a purification channel; step 2: preliminary filtration of suspended matter, conveying the aquaculture tailwater collected in the purification channel to a screen water absorption pool, filtering out suspended solid garbage impurities and large suspended particles; step 3: re-filtration of suspended matter, conveying the aquaculture tailwater treated in the screen water absorption pool to a gravity-type fully automatic dissolved oxygen fine filter for filtration; step 4: adsorption, decomposition, and consumption of pollutants, purifying the aquaculture wastewater; step 5: discharging the aquaculture wastewater. This solution utilizes the rotary screen machine of the screen water absorption pool for preliminary filtration, reducing the number of times the subsequent filtration equipment needs to be flushed; the high-efficiency biological filter also functions as an artificial wetland, utilizing the nitrification and denitrification of microorganisms and the absorption of nitrogen and phosphorus by aquatic plants while degrading organic matter, which can greatly save facility land.

Description

Technical Field

[0001] The present invention relates to the technical field of aquaculture tail water treatment, and in particular to a method for efficiently treating aquaculture tail water. Background Art

[0002] Aquaculture tailwater refers to water in which, due to the metabolism and accumulation of excrement, feed residues, drug residues and other substances of fish and other organisms during the aquaculture process, the content of harmful substances such as ammonia nitrogen, nitrite, hydrogen sulfide in the water body increases, the water quality deteriorates, and has adverse effects on farmed organisms.

[0003] At present, aquaculture tailwater is mainly treated through the three-pond and two-dam tailwater treatment mode, the three-stage filtration treatment mode, the shore-based integrated equipment treatment mode, etc. Among them, the "three-pond and two-dam" ecological treatment process: the three-pond and two-dam technology has a large water treatment capacity and high technical maturity; the inlet and outlet water are separated independently, which can reduce the spread of water diseases; but PAC agents need to be added in the sedimentation tank stage, resulting in an increase in sludge; and the occupied area is large, which will occupy 8%-10% of the total aquaculture area. Three-stage filtration tailwater treatment mode: The construction difficulty is not high and the maintenance is simple; the water level difference is used to drain water and save electricity; but the overflow pipe at the bottom of the pond is easy to clog, and the filter material needs to be cleaned frequently, and the subsequent maintenance is more complicated. Shore-based integrated equipment tailwater treatment mode: The equipment occupies a small area, is easy to install, and is simple to maintain; the daily tailwater discharge volume is 2-3m 3 ; Recirculating aquaculture can reduce the invasion of foreign diseases, but the equipment installation cost is high and the power consumption is relatively high; and the sewage absorption capacity range is not wide, and multiple water trucks are needed to promote the flow of water. Summary of the Invention

[0004] The present invention aims to provide an efficient treatment method for aquaculture tail water, so as to solve the problems that the current treatment equipment occupies a large area, requires a large number of fish ponds, and is prone to filter material clogging during the treatment process.

[0005] To achieve the above object, the present invention adopts the following technical solution: a method for efficiently treating aquaculture tail water, comprising the steps of: 1. collecting aquaculture wastewater and transporting the aquaculture tail water from the sludge pool to a purification channel;

[0006] Step 2: Preliminary filtration of suspended matter: The aquaculture tailwater collected in the purification channel is transported to the screen water absorption pool, and the rotary screen machine in the screen water absorption pool is used to filter out suspended solid waste impurities and large particles of suspended matter;

[0007] Step 3: The suspended matter is filtered again, and the aquaculture tail water treated in the screen water absorption tank is transported to the gravity type fully automatic dissolved oxygen fine filter for filtration again;

[0008] Step 4: Pollutant treatment: The aquaculture tail water treated by the gravity-type fully automatic dissolved oxygen fine filter is transported to the biological filter. The internal matrix, plants and microorganisms in the biological filter work together to adsorb, decompose and consume pollutants, purifying the aquaculture wastewater.

[0009] Step 5: Discharge aquaculture wastewater and discharge the wastewater treated by the biological filter.

[0010] It is further defined that in step 1, the aquaculture tail water from the sludge pool enters the purification channel through a weir provided on the sludge pool.

[0011] Further limitation includes: sedimentation treatment of the sludge filtered out by the gravity-type fully automatic dissolved oxygen fine filter in step 3, and reuse of the sludge after treatment.

[0012] It is further defined that the aquaculture tail water treated in the grid suction tank is transported to a gravity-type fully automatic dissolved oxygen fine filter through a submersible sewage pump and a drainage pipe connected to the submersible sewage pump.

[0013] It is further defined that step 3 simultaneously treats the aquaculture tail water through multiple gravity-type fully automatic dissolved oxygen fine filters.

[0014] It is further defined that the backwash outlet pipe of the gravity-type fully automatic dissolved oxygen fine filter is connected to the sludge tank.

[0015] It is further defined that the biofilter is provided with a plurality of filter modules, gaps are provided between the filter modules, an outlet channel is formed between the filter modules and the biofilter, the filter module includes a biofilter layer and a water distribution device for adding tailwater to the biofilter layer, the biofilter layer is provided with a plant layer, a covering layer, a sponge medium soil layer, a coarse sand layer, a gravel layer, a water blind pipe, an HDPE membrane, a sand and gravel cushion layer, and a plain soil layer from top to bottom, the water blind pipe is connected to the outlet channel via a drain pipe, and the water blind pipe is provided with a through hole. The top layer of the biofilter is set as a plant layer to absorb and decompose pollutants. No bacterial agent costs are required for subsequent operation and maintenance. The biofilter only needs to be harvested regularly without replanting.

[0016] It is further defined that the water distribution device includes a second water distribution channel and a third water distribution channel, the second water distribution channel is located on both sides of the biological filtration layer, the second water distribution channel and the baffles arranged on the other two sides of the biological filtration layer cooperate to protect the biological filtration layer, the third water distribution channel is connected to the second water distribution channel, and the two ends of the third water distribution channel are respectively fixed on the second water distribution channel at the corresponding ends, and a water distribution hole is provided at the bottom of the third water distribution channel.

[0017] It is further defined that an arc-shaped piece is slidingly provided in the siphon riser of the gravity-type fully automatic dissolved oxygen fine filter, and the arc-shaped piece is fixed to the inner wall of the siphon riser by an elastic member. The arc-shaped piece moves and blocks the connection between the siphon riser and the U-shaped tube of the gravity-type fully automatic dissolved oxygen fine filter when the water flow is backwashing the filter layer. A through hole is provided on the arc-shaped piece, and a bulge is formed on the side of the through hole away from the U-shaped tube.

[0018] The working principle of the gravity-type fully automatic dissolved oxygen fine filter (gravity-type valveless filter) is as follows: Raw water filtration process: clean water after sedimentation or clarification enters the siphon riser through the water distribution trough and U-shaped pipe, and is then evenly distributed to the filter layer by the baffle. The water is filtered from top to bottom through the filter layer. The filtered water is collected by the low-resistance water distribution device and then enters the clean water area (i.e. the water outlet tank) for storage. When the water level rises to the outlet pipe, the filtered water flows to the clean water tank by gravity. The backwash process is as follows: as the filtration time goes by, the particle impurities on the surface of the filter layer gradually increase, and the head loss also increases, causing the water level in the siphon riser to continue to rise. When the head loss reaches a certain level, the water level in the siphon riser rises to the siphon auxiliary pipe mouth and flows down rapidly, taking away the air in the siphon downpipe, forming a siphon effect, and starting the backwash process; because the water level in the water distribution tank is higher than the highest water level of the siphon upper and lower pipes, under the action of gravity, the resistance of the water in the U-shaped pipe will be less than the resistance of the water in the flushing water tank. During the backwash process, the water in the U-shaped pipe will continue to enter the siphon riser in large quantities, affecting the water in the flushing water tank from entering the siphon riser, affecting the backwash water volume, and affecting the flushing effect of the filter layer. By setting the arc plate and elastic member, during backwashing, the water in the flushing water tank causes the arc plate to overcome the action of the elastic member and move upward to block the U-shaped pipe, increasing the backwash water volume and enhancing the filtration effect of the filter layer; at the same time, it also reduces the meaningless loss of water in the water distribution tank.

[0019] Furthermore, when the curved sheet blocks the U-shaped tube, part of the through-holes of the curved sheet are located within the water outlet of the U-shaped tube. Thus, after siphoning stops, water in the U-shaped tube will flow downward through the through-holes, thereby driving the curved sheet downward to return to its original position and preventing the curved sheet from being continuously pressed against the water outlet of the U-shaped tube due to high water pressure.

[0020] The beneficial effects of the present invention are:

[0021] 1. High Efficiency: The gravity-driven fully automatic dissolved oxygen fine filter's oxygenation and filtration greatly improves suspended solids removal efficiency while replenishing water oxygen, paving the way for subsequent treatment units. High-efficiency biological filters also function as constructed wetlands, degrading organic matter while utilizing microbial nitrification and denitrification, as well as nitrogen and phosphorus absorption by aquatic plants, to fully remove nitrogen and phosphorus nutrients from the water, reducing water pollution indicators and conserving facility land.

[0022] 2. Energy saving: The high-power equipment in the entire tailwater treatment system is three lifting pumps. The flow between the treatment units is achieved through gravity flow, which saves energy and achieves sustainable operation.

[0023] 3. Use the rotary screen machine in the screen water absorption tank for preliminary filtration to reduce the number of times the subsequent filtration equipment needs to be flushed.

[0024] 4. By arranging the arc-shaped sheet and the elastic member, when backwashing, the water in the flushing water tank causes the arc-shaped sheet to overcome the action of the elastic member and move upward to block the U-shaped tube, thereby increasing the backwash water volume and enhancing the filtering effect of the filter layer; at the same time, it also reduces the meaningless loss of water in the water distribution tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The figure is a flow chart of a method for efficiently treating aquaculture tail water according to an embodiment of the present invention.

[0026] Figure 2 It is a structural schematic diagram of a land-saving aquaculture tailwater treatment system according to an embodiment of the present invention.

[0027] Figure 3 It is a schematic structural diagram of the grid water absorption tank, gravity-type fully automatic dissolved oxygen fine filter and sludge tank according to an embodiment of the present invention.

[0028] Figure 4 Schematic diagram of the structure of the biological filter according to an embodiment of the present invention.

[0029] Figure 5 For the embodiment of the present invention Figure 4 AA direction cross-sectional diagram.

[0030] Figure 6 For the embodiment of the present invention Figure 4 A partial enlarged view of .

[0031] Figure 7 For the embodiment of the present invention Figure 4 BB direction cross-sectional diagram.

[0032] Figure 8 For the embodiment of the present invention Figure 6 A partial enlarged view of .

[0033] Figure 9 This is a schematic structural diagram of the siphon riser, U-shaped tube and arc-shaped sheet according to an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The following is further described in detail through specific implementation methods:

[0035] The figure marks in the drawings of the specification include: purification channel 1, screen water absorption pool 2, water inlet channel 21, screen channel 22, water collection channel 23, gravity-type fully automatic dissolved oxygen fine filter 3, fine filter water inlet pipe 31, water inlet electromagnetic flowmeter 32, biological filter 4, biological filter layer 41, water blind pipe 411, drainage pipe 412, second water distribution channel 5, third water distribution channel 6, support column 7, submersible sewage pump 8, siphon riser 9, U-shaped tube 10, arc-shaped sheet 11, elastic member 12.

[0036] Example:

[0037] A highly efficient method for treating aquaculture tail water, as shown in the following Figure 1 As shown, the following steps are included:

[0038] Step 1: Collect aquaculture wastewater and transport the aquaculture tail water from the sludge pool to the purification channel 11.

[0039] In this step, the aquaculture tail water in the sludge pool enters the purification channel 11 through the weir provided on the sludge pool.

[0040] Step 2: Preliminary filtration of suspended matter: The aquaculture tail water collected in the purification channel 11 is transported to the screen water absorption pool, and the rotary screen machine in the screen water absorption pool is used to filter out suspended solid garbage impurities and large particles of suspended matter.

[0041] In this step, the grid in the grid pool intercepts the suspended solid garbage and impurities as well as some large particles of suspended matter in the water to prevent these garbage, impurities and suspended matter from flowing into subsequent units.

[0042] This step specifically includes: the aquaculture tail water collected in the purification channel 11 first flows into the water inlet channel 21 of the screen water absorption pool, and then the gate between the water inlet channel 21 and the screen channel 22 is controlled to make the water inlet channel 21 and the screen channel 22 connected, and the aquaculture tail water enters the screen channel 22, and the suspended solid garbage impurities and large particles of suspended matter are filtered out by the rotary screen machine, and the filtered water enters the collection channel 23.

[0043] Step 3: The suspended matter is filtered again, and the aquaculture tail water treated by the screen water absorption tank is transported to the gravity type fully automatic dissolved oxygen fine filter 3 for filtering again.

[0044] In this step, the aquaculture tail water treated in the grid water absorption tank is transported to the gravity-type fully automatic dissolved oxygen fine filter 3 through the submersible sewage pump 8 and the drainage pipe connected to the submersible sewage pump 8.

[0045] In this step, the aquaculture tail water is treated simultaneously by multiple gravity-type fully automatic dissolved oxygen fine filters 3 to speed up the treatment of aquaculture wastewater.

[0046] In this step, after the raw water reaches the top of the equipment, it automatically flows from top to bottom by its own weight after aeration and dissolved oxygen, and then flows through the composite graded filter material filter layer for filtration, intercepting pollutants layer by layer. The clean water gathers at the bottom and then rises to the upper clean water tank for collection and then flows out and enters the high-efficiency biological filter 4.

[0047] Step 4: Pollutant Treatment: After being treated by the gravity-type fully automatic dissolved oxygen fine filter 3, the aquaculture tailwater is transferred to the biofilter 4. The matrix, plants, and microorganisms within the biofilter 4 work synergistically to absorb, decompose, and consume pollutants, purifying the aquaculture wastewater. Through the synergistic effects of the matrix, plants, and microorganisms, pollutants are absorbed and decomposed by the plants and microorganisms, resulting in purified wastewater. Finally, after treatment in the high-efficiency biofilter 4, the wastewater meets discharge standards.

[0048] Step 5: Discharge the aquaculture wastewater and discharge the wastewater treated by the biological filter 4.

[0049] The method further includes: subjecting the sludge filtered out by the gravity-type fully automatic dissolved oxygen fine filter 3 in step 3 to sedimentation treatment, and utilizing the sludge after treatment.

[0050] Among them, the backwash outlet pipe of the gravity-type fully automatic dissolved oxygen fine filter 3 is connected to the sludge tank.

[0051] This solution also provides a land-saving aquaculture tailwater treatment system for implementing the above method, as shown in the attached Figure 2 As shown, it includes: a purification channel 1, a grid water absorption pool 2, a gravity-type fully automatic dissolved oxygen fine filter 3 and a biological filter 4 which are arranged in sequence.

[0052] Purification Channel 1 is used to precipitate, degrade, and purify tailwater from a sludge pond (i.e., a fish pond). The connection between Purification Channel 1 and the sludge pond is located at the top of the sludge pond's outlet weir, which reduces the amount of sludge entering the tailwater from Purification Channel 1 and minimizes its impact on the overall system's treatment efficiency. In this embodiment, tailwater from the sludge pond is transported to Purification Channel 1 via a W-DN300-HDPE double-wall corrugated pipe.

[0053] The screen water absorption pool 2 is connected to the purification channel 1, and the screen water absorption pool 2 is used to filter and remove impurities from the tail water discharged from the purification channel 1. Figure 3As shown, the screen water absorption pool 2 is provided with an inlet channel 21, a screen channel 22 and a water collection channel 23 which are connected in sequence. A gate is provided at the connection between the water inlet channel 21 and the screen channel 22. A rotary screen machine is provided in the screen channel 22. The structure of the rotary screen machine includes a driving device, a frame, a sprocket, a chain, rake teeth, a cleaning device and an elastic overload protection device. The equipment is assembled into a rotary screen chain using a set of unique rake teeth. Driven by the motor reducer, the rake tooth chain rotates in the opposite direction of the water flow. When the rake tooth chain runs to the upper part of the equipment, a relative self-cleaning movement is generated between each set of rake teeth through the guidance of the groove wheel and the curved rail. Most of the solid matter falls by gravity, and the other part relies on the reverse movement of the sweeper to clean up the debris stuck on the rake teeth. It can automatically and continuously intercept and remove debris of various shapes from the fluid, effectively separating solids and liquids. It boasts a high degree of automation, high separation efficiency, low power consumption, quiet operation, and excellent corrosion resistance, ensuring continuous and stable operation even in unattended conditions. An overload safety device automatically shuts down the machine in the event of a malfunction, preventing overload. The recycling screen machine effectively prevents screen blockage, which can affect the efficiency of the screen water absorption tank.

[0054] Among them, a plurality of grille channels 22 are provided in the grille water absorption pool to improve the filtering efficiency of the grille water absorption pool. In this embodiment, two grille channels 22 are provided, and the two grille channels 22 are symmetrically arranged in the grille water absorption pool.

[0055] The surface of the water collection channel 23 is paved with a grid cover.

[0056] The gravity-type fully automatic dissolved oxygen fine filter 3 is connected to the grid water absorption tank, and the gravity-type fully automatic dissolved oxygen fine filter 3 is used to filter the tail water after being treated by the grid water absorption tank. The working principle of the gravity-type fully automatic dissolved oxygen fine filter 3 (gravity-type valveless filter) is as follows: Raw water filtration process: After sedimentation or clarification, the clean water enters the siphon riser 9 through the water distribution tank and U-shaped pipe 10, and is then evenly distributed to the filter material layer by the baffle. The water passes through the filter material layer from top to bottom for filtration. The filtered water is collected by the low-resistance water distribution device and enters the clean water area (i.e., the water outlet tank) for storage. When the water level rises to the outlet pipe, the filtered water flows into the clean water tank by gravity. Backwash process: As filtration time passes, particulate impurities on the surface of the filter layer gradually increase, and the head loss also increases accordingly, causing the water level in the siphon pipe to continue to rise. When the head loss reaches a certain level, the water level in the siphon pipe rises to the siphon auxiliary pipe mouth and flows rapidly downward, carrying away the air in the siphon downpipe, forming a siphon effect, and the backwash process begins. Siphon destruction and filtration restart: When the water level in the flushing water tank drops to the siphon destruction pipe, air enters the siphon pipe, destroying the siphon effect, ending the backwash and resuming filtration.

[0057] As attached Figure 9As shown, an arc-shaped piece 11 is provided in the siphon riser 9 of the gravity-type fully automatic dissolved oxygen fine filter for sliding movement. In this embodiment, a chute is provided in the siphon riser 9, and the arc-shaped piece 11 is slidably provided in the chute. The arc-shaped piece 11 is fixed to the inner wall of the siphon riser 9 by an elastic member 12. In this embodiment, the elastic member 12 is a spring. When the water flow is used to backwash the filter layer, the arc-shaped piece 11 moves to block the connection between the siphon riser 9 and the U-shaped tube 10 of the gravity-type fully automatic dissolved oxygen fine filter. A through hole is provided on the arc-shaped piece 11, and a bulge is formed on the side of the through hole away from the U-shaped tube 10. Since the water level in the water distribution tank is higher than the highest water level of the upper and lower siphon pipes, under the action of gravity, the resistance of the water in the U-shaped tube 10 will be less than the resistance of the water in the flushing water tank. During the backwashing process, the water in the U-shaped tube 10 will continue to flow into the siphon riser 9 in large quantities, which will affect the water in the flushing water tank from entering the siphon riser 9, affect the backwash water volume, and affect the flushing effect of the filter layer. By providing the arc-shaped sheet 11 and the elastic member 12, when backwashing is performed, the water in the flushing water tank causes the arc-shaped sheet 11 to overcome the action of the elastic member 12 and move upward to block the U-shaped tube 10, thereby increasing the backwash water volume and enhancing the filtering effect of the filter layer; at the same time, it also reduces the meaningless loss of water in the water distribution tank.

[0058] When the arc piece 11 blocks the U-shaped tube 10, part of the through hole of the arc piece 11 is located within the range of the U-shaped tube 10. In this way, after the siphon stops, under the reset action of the spring and the impact of the downward flow of water in the U-shaped tube 10, the arc piece 11 moves downward to return to its original position, thereby completely opening the U-shaped tube 10.

[0059] Among them, there are two water distribution troughs, and a baffle is provided between the water distribution troughs. The top of the baffle is lower than the top of the water distribution trough. In this way, when the U-shaped pipe 10 is blocked by the arc-shaped sheet 11, the water in the water distribution trough connected to the blocked U-shaped pipe 10 can enter the adjacent water distribution trough through the top of the baffle, thereby preventing water from overflowing from this water distribution trough.

[0060] The tailwater from the screen suction tank 2 is pumped through a submersible sewage pump 8 and a fine filter inlet pipe 31 to a gravity-type fully automatic dissolved oxygen fine filter 3. The submersible pump controls the water intake of the entire system, strictly controlling the system flow rate to ensure optimal water output. The fine filter inlet pipe 31 passes through the screen cover and is located at the bottom of the water collection channel 23. An electromagnetic flowmeter 32 is installed on the fine filter inlet pipe 31, which allows for more precise control of the water intake of the entire system.

[0061] Multiple gravity-type fully automatic dissolved oxygen fine filters 3 are provided. Each of their outlet pipes is connected to the biological filter 4, and their inlet pipes 31 are connected to the screen water absorption tank 2. Multiple gravity-type fully automatic dissolved oxygen fine filters 3 are provided to increase the speed and efficiency of tailwater treatment. In this embodiment, three gravity-type fully automatic dissolved oxygen fine filters 3 are provided, specifically model W-DN600-CS.

[0062] Among them, the backwash outlet pipe of the gravity-type fully automatic dissolved oxygen fine filter 3 is connected to the sludge pool for circulation and purification again.

[0063] Among them, the sludge filtered out by the gravity-type fully automatic dissolved oxygen fine filter 3 is precipitated in the sludge pool and then regularly extracted and transported to a third-party solid waste qualification unit for disposal or piled on the pond embankment on site.

[0064] The biological filter 4 is connected to the gravity-type fully automatic dissolved oxygen fine filter 3, and the biological filter 4 is used to absorb and purify the tail water treated by the gravity-type fully automatic dissolved oxygen fine filter 3. Figure 4 , Attachment Figure 5 , Attachment Figure 6 , Attachment Figure 7 and attached Figure 8 As shown, the biofilter 4 is equipped with multiple filtration modules. In this embodiment, there are six filtration modules, with gaps between them. An outlet channel is formed between the filtration modules and the biofilter 4. The filtration modules include a biofilter layer 41 and a water distribution device for adding tailwater to the biofilter layer 41. From top to bottom, the biofilter layer 41 is equipped with a plant layer, a cover layer, a sponge medium soil layer, a coarse sand layer, a gravel layer, a water blind leg 411, an HDPE membrane, a sand and gravel cushion layer, and a plain soil layer. The water blind leg 411 is connected to the outlet channel via a drain pipe 412, which is provided with a through hole. In this embodiment, the drain pipe 412 is an L-shaped PVC pipe. This solution utilizes the synergistic effects of the internal matrix, plants, and microorganisms. Pollutants are absorbed and decomposed by the plants and microorganisms, resulting in purified wastewater. Ultimately, the wastewater meets discharge standards after treatment in the high-efficiency biofilter 4. The top layer of the biofilter 4 is a plant layer to absorb and decompose pollutants. Later operation and maintenance does not require the cost of microbial agents. The biofilter 4 only needs to be harvested regularly, without the need for replanting.

[0065] Among them, the permeability of sponge medium soil is shown in Table 1:

[0066] Table 1 Permeability

[0067]

[0068] The evaluation of the purification performance of sponge medium soil is shown in Table 2:

[0069] Table 2 Purification performance evaluation indicators

[0070]

[0071] The water distribution device includes a second water distribution channel 5 and a third water distribution channel 6. The second water distribution channel 5 is located on both sides of the biological filter layer 41. The baffles provided on the other two sides of the second water distribution channel 5 and the biological filter layer 41 cooperate to protect the biological filter layer 41. The third water distribution channel 6 is connected to the second water distribution channel 5. The two ends of the third water distribution channel 6 are respectively fixed on the second water distribution channel 5 at the corresponding ends, specifically fixed by expansion bolts. A water distribution hole is provided at the bottom of the third water distribution channel 6. The tail water is evenly distributed to the plant layer through the second water distribution channel 5 and the third water distribution channel 6. The sewage enters the second water distribution channel 5 of the biological filter tank 4 and is evenly distributed through the third water distribution channel 6 of the next level. Among them, the second water distribution channel 5 includes a bottom plate and a square trough. The bottom plate and the baffle cooperate to protect the biological filter layer 41. The bottom of the square trough is higher than the top of the third water distribution channel 6. The third water distribution channel 6 is a PVC pipe, and an opening is made at its bottom to form a water distribution hole. A second water distribution channel 5 may be provided in the middle of the biological filtration layer 41 and connected to a corresponding third water distribution channel 6 so that the tail water is evenly distributed to the plant layer.

[0072] The third water distribution channel 6 is supported by support columns 7, which are located in the biological filter layer 41. The support columns 7 support the third water distribution channel 6 to prevent the middle part of the third water distribution channel 6 from being suspended in the air and easily broken, which would affect the tail water from entering the biological filter layer 41.

[0073] The present invention can greatly improve the removal efficiency of suspended matter through the oxygenation and filtration effect of the gravity-type fully automatic dissolved oxygen fine filter, while replenishing the oxygen content of the water body, paving the way for subsequent treatment units; the high-efficiency biological filter also has the function of an artificial wetland. While degrading organic matter, it utilizes the nitrification and denitrification effects of microorganisms and the absorption of nitrogen and phosphorus by aquatic plants to fully remove nitrogen and phosphorus nutrients in the water body and reduce the pollution indicators of the water body; the system has high integration, small footprint, and saves facility land; the tail water treatment facility has two water outlets, on the one hand, it can discharge qualified water bodies in time, and on the other hand, it can recycle the treated water bodies; the high-power equipment of the entire tail water treatment system is three lifting pumps, and the flow mode between the treatment units is realized by gravity self-flow, with low energy consumption and sustainable operation; the gravity-type dissolved oxygen fine filter can be automatically cleaned and is simple to maintain; the aquaculture tail water treated by the above process can be directly reused or discharged, with good environmental benefits.

[0074] The above is only an embodiment of the present invention, and the common knowledge such as the specific technical solutions and / or characteristics in the solution are not described in detail here. It should be pointed out that for those skilled in the art, several variations and improvements can be made without departing from the technical solution of the present invention. In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The scope of protection claimed by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A highly efficient method for treating aquaculture tail water, characterized in that: include: Step 1: Collect aquaculture wastewater and transport the aquaculture tail water from the sludge pool to the purification channel; Step 2: Preliminary filtration of suspended matter: The aquaculture tailwater collected in the purification channel is transported to the screen water absorption pool, and the rotary screen machine in the screen water absorption pool is used to filter out suspended solid waste impurities and large particles of suspended matter; Step 3: The suspended matter is filtered again, and the aquaculture tail water treated in the grid water absorption pool is transported to the gravity-type fully automatic dissolved oxygen fine filter through a submersible sewage pump for filtering again. The siphon riser of the gravity-type fully automatic dissolved oxygen fine filter is provided with an arc-shaped piece slidingly arranged in the siphon riser, and a chute is provided in the siphon riser. The arc-shaped piece is slidably arranged in the chute. The arc-shaped piece is fixed to the inner wall of the siphon riser by an elastic member. When the water flow backwashes the filter layer, the arc-shaped piece moves to block the connection between the siphon riser and the U-shaped tube of the gravity-type fully automatic dissolved oxygen fine filter. A through hole is provided on the arc-shaped piece, and a bulge is formed on the side of the through hole away from the U-shaped tube; Step 4: Pollutant treatment: The aquaculture tail water treated by the gravity-type fully automatic dissolved oxygen fine filter is transported to the biological filter. The internal matrix, plants and microorganisms in the biological filter work together to adsorb, decompose and consume pollutants, purifying the aquaculture wastewater. Step 5: Discharge aquaculture wastewater and discharge the wastewater treated by the biological filter.

2. The method for efficiently treating aquaculture tail water according to claim 1, wherein: In the step 1, the aquaculture tail water in the sludge pool enters the purification channel through the weir provided on the sludge pool.

3. The method for efficiently treating aquaculture tail water according to claim 1, wherein: Also includes: The sludge filtered out by the gravity-type fully automatic dissolved oxygen fine filter in step 3 is subjected to sedimentation treatment.

4. The method for efficiently treating aquaculture tail water according to claim 1, wherein: The aquaculture tail water treated in the grid water absorption tank is transported to the gravity-type fully automatic dissolved oxygen fine filter through a submersible sewage pump and a drainage pipe connected to the submersible sewage pump.

5. The method for efficiently treating aquaculture tail water according to claim 1, wherein: In step 3, the aquaculture tail water is treated simultaneously by multiple gravity-type fully automatic dissolved oxygen fine filters.

6. The method for efficiently treating aquaculture tail water according to claim 1, wherein: The backwash outlet pipe of the gravity-type fully automatic dissolved oxygen fine filter is connected to the sludge tank.

7. The method for efficiently treating aquaculture tail water according to claim 1, wherein: The biological filter is provided with a plurality of filter modules, gaps are provided between the filter modules, an outlet channel is formed between the filter modules and the biological filter, the filter module includes a biological filter layer and a water distribution device for adding tail water to the biological filter layer, the biological filter layer is provided with a plant layer, a covering layer, a sponge medium soil layer, a coarse sand layer, a gravel layer, a water blind pipe, an HDPE membrane, a sand and gravel cushion layer and a plain soil layer from top to bottom, the water blind pipe is connected to the outlet channel through a drainage pipe, and the water blind pipe is provided with a through hole.

8. The method for efficiently treating aquaculture tail water according to claim 7, wherein: The water distribution device includes a second water distribution channel and a third water distribution channel. The second water distribution channel is located on both sides of the biological filtration layer. The second water distribution channel and the baffles arranged on the other two sides of the biological filtration layer cooperate to protect the biological filtration layer. The third water distribution channel is connected to the second water distribution channel. The two ends of the third water distribution channel are respectively fixed on the second water distribution channel at the corresponding ends. A water distribution hole is provided at the bottom of the third water distribution channel.

9. The method for efficiently treating aquaculture tail water according to claim 1, wherein: When the arc-shaped piece blocks the U-shaped tube, part of the through holes of the arc-shaped piece is located within the water outlet range of the U-shaped tube.

Images