A skid-mounted backwashing filter device and a method for treating aquaculture tail water

Abstract

The present application relates to tail water treatment technical field, disclose a pry dress formula backwash filter device, aquaculture tail water treatment method, pry dress formula backwash filter device includes: frame body, the filler assembly is set up in the frame body inside, the backwash assembly is set up in the frame body bottom and the biochemical filtration structure is partially through the frame body, the frame body has water inlet end surface and water outlet end surface, the frame body includes first frame body, second frame body and third frame body, which are sequentially spliced along the vertical direction, the first frame body, the second frame body has mesh, the third frame body has water flow blocking surface, the biochemical filtration structure is set up along the direction perpendicular to the frame body, and the middle part of the first frame body and the second frame body is penetrated, after water flow enters the frame body from the water inlet end surface, it is penetrated through the frame body after U type flow, and then it flows from the water outlet end surface. The pry dress formula backwash filter device modular construction, short construction period, it is convenient to operation and maintenance cleaning, improves long-term operation stability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tail water treatment, and particularly relates to a pry-mounted backwashing filter device and a treatment method of aquaculture tail water. BACKGROUND

[0002] Aquaculture tail water contains a large amount of suspended solids, nitrogen and phosphorus compounds and organic matter and other pollutants, and if directly discharged, it is easy to cause ecological problems such as water eutrophication, so efficient tail water treatment technology has become the key to the sustainable development of the aquaculture industry. The three-pool two-dam process, as a mature ecological combined treatment technology, is widely used in aquaculture tail water treatment. The core of the process consists of a sedimentation tank, an aeration tank, an ecological purification tank and a filter dam. The filter dam, as a key link connecting the two functional tanks, plays a decisive role in tail water purification.

[0003] The purification principle of the filter dam mainly includes physical filtration, water flow regulation and biofilm degradation. Physical filtration mainly relies on multiple layers of fillers with different particle sizes to intercept suspended solids, algae and particulate organic matter, such as pebbles, ceramic balls, brown sheets, zeolites or artificial filter materials, etc. Water flow regulation mainly slows down the tail water flow rate and prolongs the hydraulic retention time. Biofilm degradation mainly relies on the microorganism film attached to the surface of the filler to decompose and adsorb tail water pollutants. Some designs also combine plant roots to further enhance the purification effect.

[0004] Currently, from the perspective of structural design, the main body of the filter dam is mostly a brick-concrete structure composed of hollow bricks and reinforced concrete as a frame, which has a long construction period and is difficult to quickly adapt to the flexible layout requirements of the breeding site. Moreover, in terms of operation and maintenance, feedback from practice shows that the filter dam is prone to filler blockage due to untimely operation and maintenance, which leads to a decrease in suspended solids removal rate after long-term operation, thereby affecting the overall process stability and efficiency. In terms of cleaning, since the filter material is usually submerged in water, the water in the entire three-pool two-dam system needs to be emptied to clean the filler inside the dam body, which is not only difficult but also inefficient, and the cleaning frequency is usually only once a year, greatly increasing the operation and maintenance cost. In addition, a biofilm is formed on the surface of the filler in the filter dam, and there is a lack of necessary oxygenation and backwashing measures in the filter dam, making it difficult for the aged biofilm to fall off, which weakens the water quality purification function of the filler and affects the water flow rate, further restricting the tail water treatment effect. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a pry-mounted backwashing filter device that can shorten the construction period, facilitate operation and maintenance, and improve long-term operation stability.

[0006] The technical problem to be solved by the present application is to provide a treatment method of aquaculture tail water using a pry-mounted backwashing filter device, which has high treatment efficiency and stable effluent water quality.

[0007] To solve the above technical problems, the first aspect of the present application provides a skid-mounted backwashing filter device for treating aquaculture tail water, comprising a frame body, a filler assembly arranged inside the frame body, a backwashing assembly arranged at the bottom of the frame body, and a biochemical filter structure partially penetrating the frame body.

[0008] The frame body has a water inlet end face and a water outlet end face, wherein the frame body comprises a first frame body, a second frame body and a third frame body arranged in sequence in the vertical direction, the first frame body and the second frame body have mesh holes, and the third frame body has a water flow blocking surface.

[0009] The biochemical filter structure is arranged in a direction perpendicular to the frame body and penetrates the middle part of the first frame body and the second frame body, and comprises a flexible biochemical filter layer and a fixed frame, and the flexible biochemical filter layer is fixed to the middle part of the first frame body and the second frame body by the fixed frame.

[0010] After the water flow enters the frame body from the water inlet end face, it flows through the first frame body, the second frame body, the third frame body, the second frame body and the first frame body in sequence, and the water flow forms a U-shaped flow direction and penetrates the frame body, and then flows out from the water outlet end face.

[0011] As an improvement of the above scheme, the water permeability of the flexible biochemical filter layer is greater than or equal to 500 L / (h·m 2 ), and the deformation rate in the hydrated state is less than or equal to 5%, so that a potential liquid difference is formed under the blocking action of the flexible biochemical filter layer, and the water flow forms a U-shaped flow direction and penetrates the frame body, and then flows out from the water outlet end face.

[0012] As an improvement of the above scheme, the surface of the flexible biochemical filter layer forms a complex microbial flora, and the complex microbial flora decomposes ammonia nitrogen, nitrite and organic matter in the aquaculture tail water.

[0013] As an improvement of the above scheme, the height of the biochemical filter structure is higher than the water inlet line, the flexible biochemical filter layer is a hollow polyester fiber membrane layer, the porosity of the hollow polyester fiber membrane layer is greater than or equal to 85%, the pore diameter is greater than or equal to 30 PPI, and the surface roughness Ra value is greater than or equal to 12.5 μm;

[0014] The thickness of the flexible biochemical filter layer is 2%-4% of the width of the frame body;

[0015] The thickness of the fixed frame is 2%-4% of the thickness of the flexible biochemical filter layer.

[0016] As an improvement of the above scheme, the hollow polyester fiber membrane layer is a modified hollow polyester fiber membrane layer, and a preparation method of the modified hollow polyester fiber membrane layer comprises the following steps:

[0017] The hollow polyester fiber membrane layer is immersed in an alkali solution at 40-60°C for 30-50 min, then immersed in an epichlorohydrin solution under a protective atmosphere, and triethylamine is added and reacted at 75-85°C for 2-4 h, and finally the obtained hollow polyester fiber membrane layer is washed and dried;

[0018] The concentration of the alkali solution is 0.8-1.2 mol / L;

[0019] The concentration of the epichlorohydrin solution is 8-13 wt%, and the solvent of the epichlorohydrin solution is N,N-dimethylformamide and water, and the volume ratio of N,N-dimethylformamide to water is (8.5-9.5):1;

[0020] The weight ratio of the triethylamine to the epichlorohydrin solution is 1:(0.1-0.3).

[0021] As an improvement of the above scheme, the filler assembly comprises a filler, a water-permeable filler bag for loading the filler, and a punched baffle for carrying the filler;

[0022] The punched baffle is respectively arranged between the first frame body and the second frame body, inside the second frame body, between the second frame body and the third frame body, and between the third frame body and the backwashing assembly, and the water-permeable filler bag is stacked on the punched baffle;

[0023] The filler comprises a first filler, a second filler and a third filler, the first filler is arranged in the first frame body through the punched baffle to form a primary filter layer, the second filler is arranged in the second frame body through the punched baffle to form a medium filter layer, and the third filler is arranged in the third frame body through the punched baffle to form a deep filter layer.

[0024] As an improvement of the above scheme, the backwashing assembly comprises a sealing unit, an aeration unit and a suction unit;

[0025] The sealing unit comprises a baffle arranged on one side of the water inlet end face and a first support for fixing the baffle, the baffle is movably connected with the lower end of the first support, and the first support is detachably connected to the frame body;

[0026] The aeration unit comprises an aeration support fixed on the first support, an aeration coil arranged on the aeration support, and a ventilation device connected with the aeration coil through an aeration hose, for flushing the pollutants remaining in the frame body and restoring the biofilm activity of the biochemical filter structure.

[0027] The suction unit comprises a suction port arranged inside the baffle and a shaft flow pump connected with the suction port through a drain pipe, for removing the accumulated sludge after backwashing.

[0028] As an improvement of the above scheme, the baffle is provided with through holes through which the aeration hose and the drain pipe extend out of the skid-mounted backwashing filter device.

[0029] The baffle is provided with a brush arranged obliquely in the horizontal plane of the baffle, for blocking the sludge outside the frame body from directly entering the backwashing assembly without being filtered by the filter device.

[0030] The backwashing assembly further comprises an online monitoring device connected with the ventilation device and / or the shaft flow pump.

[0031] The online monitoring device comprises a water level difference monitoring unit and / or a time period monitoring unit.

[0032] As an improvement of the above scheme, the first frame body is arranged at a height not lower than the water inlet line, the first frame body and the third frame body are made of metal, and the second frame body is made of polyethylene.

[0033] The first frame body, the second frame body, and the third frame body are arranged at a height ratio of 1: (1.4-1.6): (0.5-0.7).

[0034] The mesh size of the first frame body is larger than that of the second frame body, the mesh of the first frame body is a square mesh, and the mesh of the second frame body is a circular mesh.

[0035] As an improvement of the above scheme, the first filler is used to treat surface pollutants at a depth of 0-32% under water, the second filler is used to treat middle layer pollutants at a depth of 32%-80% under water, and the third filler is used to treat bottom layer pollutants at a depth of 80%-100% under water.

[0036] The average particle size of the first filler is greater than or equal to that of the second filler, and the average particle size of the second filler is greater than or equal to that of the third filler.

[0037] As the improvement of the above-mentioned scheme, the average particle size of the first filler is 8cm-10cm, and the first filler is selected from oyster shells;

[0038] The average particle size of the second filler is 5cm-8cm, and the second filler is selected from at least one of ceramic rings and ceramic granules;

[0039] The average particle size of the third filler is 3cm-5cm, and the third filler is selected from at least one of quartz balls and volcanic stones;

[0040] The punching baffle has a mesh size of 18mm-22mm and a thickness of 0.5mm-3mm, and is detachably connected to the frame body.

[0041] As the improvement of the above-mentioned scheme, the pry-mounted backwashing filter device further comprises a dam for fixing the frame body, and the backwashing assembly is arranged on the dam;

[0042] The upper top surface of the frame body is further provided with a movable top plate, and the top plate has a mesh;

[0043] The frame body is provided with a reinforcing beam on the periphery.

[0044] The second aspect of the present application also provides a method for treating aquaculture tail water, which adopts the pry-mounted backwashing filter device to treat the aquaculture tail water, and the treatment method comprises the following steps:

[0045] (1) At least one pry-mounted backwashing filter device is installed at a predetermined position, so that the water inlet line is not higher than the first frame body;

[0046] (2) The aquaculture tail water enters the frame body from the water inlet end face, and flows in a U-shaped manner under the action of the biochemical filter structure, and sequentially flows through the first frame body, the second frame body, the third frame body, the second frame body and the first frame body, and is purified by the filler in each frame body, and the purified aquaculture tail water flows out from the water outlet end face;

[0047] (3) After the step (2) is operated for a predetermined time, the backwashing assembly is started to remove the pollutants generated by the filtration and restore the biological membrane activity of the biochemical filter structure.

[0048] The present application has the following beneficial effects:

[0049] (1) In this invention, the mesh provided on the first frame body and the second frame body facilitates the entry of aquaculture wastewater into the frame body from the inlet end face and the exit of the frame body from the outlet end face. The water flow blocking surface provided on the third frame body can define the direction of water flow. The biochemical filtration structure can serve as a carrier to form a biofilm-type barrier through microorganisms. Both of them work together to guide the water flow, so that the aquaculture wastewater changes its flow direction under the action of liquid level difference, and the water flow path changes from a straight line to a U-shape, significantly increasing the actual flow distance, enhancing the contact efficiency between wastewater and packing material, and prolonging the residence time of pollutants in the filter dam device, thereby strengthening the purification process such as adsorption and degradation.

[0050] (2) In this invention, the aquaculture tailwater enters the frame body and is purified by the packing components set in the frame body to ensure stable effluent quality. The backwashing components can effectively clean and maintain the packing, significantly reducing the frequency of underwater operations and the need for packing replacement. While extending the service life of the packing, it reduces the risk of system blockage, enabling the filtration device to operate at high efficiency for a long time. Moreover, it can clean and maintain the packing inside the dam without completely emptying the three pools and two dams, reducing the difficulty of cleaning and reducing the later operation and maintenance costs.

[0051] (3) In this invention, the skid-mounted backwash filter adopts a modular structure, which can be flexibly arranged in single or multiple configurations according to the user's design requirements. It has flexibility and modular construction, and can be produced and pre-installed in the factory. When transported to the site, it can be directly hoisted to the installation position, and the filler can be installed on site. This greatly reduces the construction time and difficulty of the filter dam. Compared with the traditional brick filter dam, the construction period is shortened by more than 95%, and the overall cost of the entire life cycle, including splashing and subsequent operation and maintenance, is reduced by about 15%. Attached Figure Description

[0052] Figure 1 Cross-sectional view of the skid-mounted backwashing filter device in this invention. Figure 1 ;

[0053] Figure 2 Cross-sectional view of the skid-mounted backwashing filter device in this invention. Figure 2 ;

[0054] Figure 3 Cross-sectional view of the skid-mounted backwashing filter device in this invention. Figure 3 ;

[0055] Figure 4 : A schematic diagram of the frame structure in this invention;

[0056] Figure 5 : A schematic diagram of the biochemical filtration structure in this invention;

[0057] Figure 6Structure schematic diagram of the frame body in the application after setting the punching baffle in the frame body

[0058] Figure 7 Cross-sectional view of the backwashing assembly in the application Figure 1

[0059] Figure 8 Cross-sectional view of the backwashing assembly in the application Figure 2

[0060] Figure 9 Structure schematic diagram of the aeration coil in the application

[0061] Figure 10 Structure schematic diagram of the top plate provided on the upper top surface of the frame body in the application.

[0062] Reference signs:

[0063] 1-frame body;11-first frame body;12-second frame body;13-third frame body;2-packing assembly;21-packing;211-first packing;212-second packing;213-third packing;22-punching baffle;3-backwashing assembly;31-first support;32-baffle;33-brush;34-aeration support;35-aeration coil;36-aeration hose;37-suction port;38-drain pipe;4-biochemical filtration structure;41-flexible biochemical filtration layer;42-fixing frame;5-stiffening beam;6-dam;7-top plate. DETAILED DESCRIPTION

[0064] In order to make the purpose, technical scheme and advantages of the application more clear, the application will be further described in detail with specific examples.

[0065] To solve the above problems, the application provides a pry-mounted backwashing filter device, please refer to Figures 1-3 , the pry-mounted backwashing filter device is used for treating aquaculture tail water, and the pry-mounted backwashing filter device comprises a frame body 1, a packing assembly 2 provided in the frame body 1, a backwashing assembly 3 provided at the bottom of the frame body 1, and a biochemical filtration structure 4 partially penetrating the frame body 1.

[0066] In the application, the aquaculture tail water enters the frame body 1, is subjected to purification treatment by the packing assembly 2 provided in the frame body 1, and the water quality is stable, the backwashing assembly 3 is provided, which can effectively realize cleaning and maintenance of the packing, significantly reduce the frequency of underwater operation and the demand for replacing the packing, prolong the service life of the packing, reduce the risk of system blockage, make the filter device run efficiently for a long time, and realize cleaning and maintenance of the packing without completely emptying the water in the three pools and the dam, reduce the cleaning difficulty, and reduce the later operation and maintenance cost.

[0067] ​​In addition, the skid-mounted backwashing filter device in the present application adopts an assembled structure and can be arranged as a single or multiple units according to the design requirements of the user side, having flexibility and modular construction. The first frame body 11, the second frame body 12 and the third frame body 13 can be produced and pre-installed in the factory, hoisted to the installation position when transported to the site, and then the filler is installed on site, so that the installation operation is simple, and the construction time and difficulty of the filter device are greatly reduced. Compared with the traditional brick filter dam, the construction period is shortened by more than 95%, and the comprehensive cost of the whole life cycle including construction and later operation and maintenance is reduced by about 15%.

[0068] Among them, please refer to Figure 4 , the frame body 1 has a water inlet end face and a water outlet end face, wherein the frame body 1 includes a first frame body 11, a second frame body 12 and a third frame body 13 which are sequentially connected in the vertical direction, the first frame body 11 and the second frame body 12 have mesh holes through which the aquaculture tail water enters the frame body 1 from the water inlet end face, and the third frame body 13 has a water flow blocking surface; the biochemical filter structure 4 is arranged in a direction perpendicular to the frame body 1 and penetrates the middle part of the first frame body 11 and the second frame body 12, the biochemical filter structure 4 includes a flexible biochemical filter layer 41 and a fixed frame 42, the flexible biochemical filter layer 41 is fixed to the middle part of the first frame body 11 and the second frame body 12 by the fixed frame 42, and the water flow enters the frame body from the water inlet end face, sequentially flows through the first frame body 11, the second frame body 12, the third frame body 13, the second frame body 12 and the first frame body 11, and then flows out from the water outlet end face in a U-shaped flow direction.

[0069] Specifically, in the present embodiment, the skid-mounted backwashing filter device is provided with a flexible biochemical filter layer 41 which penetrates the middle part of the first frame body 11 and the second frame body 12, and can divide the first frame body 11 and the second frame body 12 into two independent areas with different water flow directions. The water flow enters the first frame body 11 from the water inlet end face and is concentrated downward under the restriction of the flexible biochemical filter layer 41, flows into the second frame body 12, and is concentrated downward under the restriction of the flexible biochemical filter layer 41, flows into the third frame body 13. At this time, the water flow flows along the horizontal direction and is concentrated upward under the restriction of the flexible biochemical filter layer 41, flows into the second frame body 12, and is concentrated upward under the restriction of the flexible biochemical filter layer 41, flows into the first frame body 11, and finally flows out from the water outlet end face.

[0070] Preferably, the water permeability of the flexible biochemical filter layer 41 is greater than or equal to 500 L / (h·m 2), the deformation rate in the hydrated state is less than or equal to 5%, so as to better form the liquid level difference under the blocking effect of the flexible biochemical filter layer 41, and make the water flow into the frame body 1 from the water inlet end face in a U-shaped manner and then flow out from the water outlet end face after penetrating through the frame body 1.

[0071] Further, the surface of the flexible biochemical filter layer 41 forms a complex microbial flora, which decomposes ammonia nitrogen, nitrite and organic matter in the aquaculture tail water. The flexible biochemical filter layer 41 can load nitrifying bacteria, denitrifying bacteria and bacillus, and other microorganisms that help to adsorb and decompose the aquaculture tail water, and form a complex microbial flora on the surface. With the secretion and proliferation of the complex microbial flora, a biofilm is formed on the surface, which can promote the degradation of ammonia nitrogen, nitrite and organic matter in the tail water under the metabolic action of the biofilm, and also can act as a biofilm barrier wall to further promote the formation of the liquid level difference.

[0072] The mesh holes provided on the first frame body 11 and the second frame body 12 facilitate the aquaculture tail water to flow into the frame body 1 from the water inlet end face and flow out of the frame body 1 from the water outlet end face, and the water flow blocking surface provided on the third frame body 13 can define the water flow direction. The biochemical filter structure 4 provided as a carrier forms a biofilm barrier wall, and the two together play a water body guiding role. The aquaculture tail water changes the flow direction under the action of the liquid level difference and flows in a U-shaped manner through the first frame body 11, the second frame body 12, the third frame body 13, the second frame body 12 and the first frame body 11 in turn, and is purified by the fillers in each frame body, so that the aquaculture tail water entering the first frame body 11 and the second frame body 12 is purified and then vertically downwardly enters the third frame body 13 and finally flows out from the water outlet end face, thereby reducing the short flow phenomenon of the water body.

[0073] Preferably, referring to Figure 1 , the height of the biochemical filter structure 4 is higher than the water inlet line, and the presence of the biochemical filter structure 4 changes the water flow path from a straight line to a U-shaped path, significantly increases the actual flow distance, enhances the contact efficiency of the tail water and the fillers, prolongs the residence time of the pollutants in the filter dam device, and thus strengthens the purification processes such as adsorption and degradation. Exemplarily, the set height of the biochemical filter structure 4 is 50 mm higher than the water inlet line. When the water level of the water inlet end face is higher than a set value or the water flow is greater than a set value, such as large-scale drainage of the upstream pond or sudden heavy rain, the tail water body can directly cross the filter dam device for emergency drainage.

[0074] Further, referring to Figure 5The flexible biochemical filter layer 41 is a hollow polyester fiber membrane layer, the porosity of the hollow polyester fiber membrane layer is greater than or equal to 85%, the pore diameter is greater than or equal to 30 PPI, that is, the pore size is less than or equal to 0.847 mm, the surface roughness Ra value is greater than or equal to 12.5 μm, and it is suitable for complex microbial flora to adhere. The thickness of the flexible biochemical filter layer 41 is 2%-4% of the width of the frame body 1, and the thickness of the fixed frame 42 is 2%-4% of the thickness of the flexible biochemical filter layer 41. Exemplarily, the thickness of the flexible biochemical filter layer 41 can be 40 mm, and the thickness of the fixed frame 42 is 1 mm. The material of the fixed frame 42 includes but is not limited to stainless steel, and exemplarily is 304 stainless steel and the like. In some specific embodiments, the biochemical filter structure 4 can be divided into two parts and fixed in the first frame body 11 and the second frame body 12, respectively. The size of the biochemical filter membrane is 1.5 m*1 m (length*width), and the size of the fixed frame 42 is 0.05 m*0.05 m (length*width).

[0075] In some specific and preferred embodiments, the hollow polyester fiber membrane layer is a modified hollow polyester fiber membrane layer, and the preparation method of the modified hollow polyester fiber membrane layer comprises the following steps: immersing the hollow polyester fiber membrane layer in an alkali solution at 40-60°C for 30-50 min, then immersing in an epichlorohydrin solution under a nitrogen protective atmosphere, adding triethylamine, and reacting at 75-85°C for 2-4 h, and finally washing and drying the obtained hollow polyester fiber membrane layer. First, the alkali treatment of the hollow polyester fiber membrane layer can form active groups such as -COOH and OH on the hollow polyester fiber membrane layer. Then, the active groups such as -COOH and OH formed are reacted with the epoxy groups in the epichlorohydrin under the action of triethylamine to form an intermediate, and then continue to react with the active groups on the adjacent hollow polyester fiber membrane layer to form a cross-linked network, which improves the mechanical properties and also improves the deformation recovery rate of the membrane layer, further enhances the water flow impact resistance and hydrolysis resistance of the hollow polyester fiber membrane layer, and exhibits long-term stability. Moreover, the residual active groups on the modified hollow polyester fiber membrane layer can also provide attachment points for microorganisms to promote the rapid formation of biofilms.

[0076] The concentration of the alkali solution is 0.8-1.2 mol / L, and the alkali solution includes but is not limited to sodium hydroxide aqueous solution. The concentration of the epichlorohydrin solution is 8-13 wt%, and the solvent of the epichlorohydrin solution is N,N-dimethylformamide and water, and the volume ratio of N,N-dimethylformamide to water is (8.5-9.5):1. The weight ratio of triethylamine to the epichlorohydrin solution is 1:(0.1-0.3). The protective atmosphere includes but is not limited to nitrogen.

[0077] Preferably, the first frame body 11 is arranged at a height not lower than the water inlet line, and the first frame body 11 and the third frame body 13 are made of metal. For example, the first frame body 11 and the third frame body 13 are made of stainless steel, and the mesh of the first frame body 11 is formed by a combination of angle steel and channel steel, which can be formed by welding in the factory. The first frame body 11 has sufficient structural strength and rigidity, excellent corrosion and rust resistance, and can avoid vibration and displacement caused by external force after long-term use, thereby prolonging the service life of the filter dam. The second frame body 12 is made of polyethylene, preferably high-density polyethylene (HDPE), which is corrosion-resistant and flexible, and can better adapt to the variable underwater environment.

[0078] Further, the first frame body 11, the second frame body 12 and the third frame body 13 are arranged at a height ratio of 1: (1.4-1.6): (0.5-0.7). The first frame body 11 bears the main water flow impact force, and the third frame body 13 can be used as a bottom reinforcing layer to form a stepped support system with the upper part to prevent the second frame body 12 from losing stability due to long-term creep. In addition, the gradient interception mechanism is formed by the arrangement of the mesh, which further strengthens the contact time with the filler. The lower third frame body 13 can form a bottom scouring area to prevent sediment accumulation and play a role in preventing blockage by using the self-cleaning effect of water flow.

[0079] In some embodiments, the frame body 1 has a size of 2.0m*1.5m*3.5m (length*width*height), the first frame body 11 is arranged at a height of 0.5m above the water inlet line, the first frame body 11 has a size of 2.0m*1.5m*1.3m (length*width*height) and is made of stainless steel; the second frame body 12 has a size of 2.0m*1.5m*1.2m (length*width*height) and is made of high-density polyethylene; and the third frame body 13 has a size of 2.0m*1.5m*0.5m (length*width*height) and is made of stainless steel.

[0080] Further, the mesh size of the first frame body 11 is larger than that of the second frame body 12, so that large particles in the aquaculture tail water first enter the first frame body 11 through the coarse mesh, and then enter the second frame body 12 after being purified by the filler arranged in the first frame body 11 for further filtration and purification treatment. The small-size mesh can simultaneously perform fine filtration, improve the filtration and purification efficiency, and also ensure the structural strength of the frame body 1.

[0081] In some embodiments, the first frame body 11 has square mesh holes with a side length of 28-32 mm and a thickness of 0.5-3 mm, and the second frame body 12 has circular mesh holes with a diameter of 6-10 mm and a thickness of 0.5-3 mm; the third frame body 13 has a thickness of 0.5-3 mm.

[0082] In some embodiments, referring to Figure 6 , the frame body 1 is provided with a reinforcing beam 5 on the periphery, which improves the structural strength of the frame body 1 and further improves the impact resistance of the frame body 1 to water flow; the reinforcing beam 5 can be made of stainless steel.

[0083] In some embodiments, referring to Figure 1 and Figure 6 , the filler assembly 2 includes a filler 21, a water-permeable filler bag (not shown in the figure) for loading the filler 21, and a punched baffle 22 for carrying the filler; the punched baffle 22 is respectively arranged between the first frame body 11 and the second frame body 12, inside the second frame body 12, between the second frame body 12 and the third frame body 13, between the third frame body 13 and the backwashing assembly 3, and the water-permeable filler bag is stacked on the punched baffle 22. In some embodiments, the water-permeable filler bag can be stacked in a triangular shape on the punched baffle 22, and through the filter medium layer formed, physical interception, charge adsorption and biological action are realized to purify the aquaculture tail water.

[0084] Further, the filler 21 includes a first filler 211, a second filler 212, and a third filler 213, the first filler 211 is arranged in the first frame body 11 through the punched baffle 22 to form a primary filter layer; the second filler 212 is arranged in the second frame body 12 through the punched baffle 22 to form a middle filter layer; the third filler 213 is arranged in the third frame body 13 through the punched baffle 22 to form a deep filter layer, through the synergistic effect of physical interception and chemical adsorption, different pollutants are filtered and purified, the filtration efficiency is significantly improved, the equipment life is prolonged, and the risk of deformation or blockage is reduced.

[0085] It can be understood that the punching baffle 22 is arranged inside the second frame body 12, which divides the first frame body 11 into two layers, but the same second filler 212 is used in the two layers, which can more effectively intercept small particles in water, improve the utilization rate of the filler 21, ensure that the water quality is more clean and dispersed impurities, and at the same time reduce the risk of single-layer blockage and prolong the service life. Specifically, the punching baffle 22 can be arranged at an upper position of the middle part of the second frame body 12, or at a middle position, or at a lower position of the middle part, and can be adjusted according to specific needs.

[0086] Preferably, the first filler 211 is used to treat surface pollutants at a depth of 0-32% under water, the second filler 212 is used to treat middle layer pollutants at a depth of 32%-80% under water, and the third filler 213 is used to treat bottom layer pollutants at a depth of 80%-100% under water. For example, the water depth of the aquaculture tail water to be treated is 2.5m, the first filler 211 is used to treat surface pollutants at a depth of 0m-0.8m under water, the second filler 212 is used to treat middle layer pollutants at a depth of 0.8m-2m under water, and the third filler 213 is used to treat bottom layer pollutants at a depth of 2m-2.5m under water. It can be understood that the frame body 1 is provided with four punching baffles 22 inside, forming an initial filter layer, a middle filter layer and a deep filter layer, and the proportion of the initial filter layer, the middle filter layer and the deep filter layer and the filling height of the filler 21 therein can be adjusted according to the actual filtering demand. With the change of the aquaculture scale or the improvement of the water quality treatment requirement, the amount of the filler 21 can be flexibly increased or reduced to adapt to different treatment requirements.

[0087] Further, the average particle size of the first filler 211 is 8cm-10cm, and the first filler 211 is selected from oyster shells. Large particle size oyster shells form a high-pore structure, efficiently intercepting large particle impurities such as suspended solids and algae, reducing the subsequent burden. The average particle size of the second filler 212 is 5cm-8cm, and the second filler 212 is selected from at least one of ceramic rings and ceramic particles. The medium particle size ceramic ring provides a large specific surface area, promotes the colonization of nitrifying bacteria, decomposes toxic substances such as ammonia nitrogen, and the void structure of the ceramic particles synchronously adsorbs colloidal impurities. The average particle size of the third filler 213 is 3cm-5cm, and the third filler 213 is selected from at least one of quartz balls and volcanic rocks. The micropores of the volcanic rock promote anaerobic bacteria denitrification and adsorb heavy metal ions, reducing the turbidity of the effluent. At the same time, the quartz ball and the volcanic rock have high hardness, which can effectively resist water flow impact and support the upper layer of filler to prevent collapse. The particle size of the three fillers decreases from top to bottom to form a density gradient, which greatly improves the pollution interception capacity, and the synergistic effect of the three specific fillers can realize the step-by-step degradation of pollutants.

[0088] More preferably, the first filler 211 is oyster shell, the second filler 212 is ceramic ring and ceramic ball, the volume ratio of the ceramic ring to the ceramic ball is 1: (1-2), more preferably 1:1.5, the third filler 213 is quartz ball and volcanic rock, the volume ratio of the quartz ball to the volcanic rock is 1: (0.5-1), more preferably 1:0.8. The different materials with similar pore diameters are used to form a comprehensive gradient filtration structure, to optimize the water flow path, to mix the pore diameter structure to form a turbulent flow in the filler layer, to reduce the dead water area, to increase the contact opportunity of the pollutants and the filler surface, to strengthen the adsorption, catalysis or biodegradation reaction; and to optimize the specific surface area, the smaller pore diameter filler provides abundant microporous structure, and the larger pore diameter filler provides support strength and permeable skeleton, which can balance the filler structure strength, adsorption capacity and mass transfer rate. Specifically, when the water flow penetrates the filler 21 from the inlet end face downward, the three-dimensional pore structure of the oyster shell in the primary filter layer mechanically retains the suspended solids and large particle pollutants in the aquaculture tail water, the ceramic ring and ceramic ball in the middle filter layer fix colloidal substances through the charge adsorption effect of the surface, and the filler in the middle filter layer and the deep filter layer provides a carrier, and the complex microbial flora composed of nitrifying bacteria, denitrifying bacteria and bacillus forms a biological membrane under the metabolic action of the biological membrane to decompose ammonia nitrogen, nitrite and organic matter in the water body, and the U-shaped water flow direction can increase the surface contact time of the tail water and the filler 21, thereby strengthening the adsorption purification treatment of the tail water.

[0089] It should be emphasized that the present application sets the biochemical filter structure 4, and the flexible biochemical filter layer 41 can be used as a carrier to form a biological membrane type retaining wall through microorganisms, to play a first level of decomposition treatment to decompose ammonia nitrogen, nitrite and organic matter in the aquaculture tail water. Secondly, the filler in the middle filter layer and the deep filter layer of the filler assembly 2 provides a carrier to form a biological membrane, to play a second level of decomposition treatment to decompose ammonia nitrogen, nitrite and organic matter in the aquaculture tail water. The biochemical filter structure 4 and the filler assembly 2 can form a semi-enclosed biological membrane filtration system, which significantly improves the adsorption purification effect of the tail water.

[0090] Specifically, the water flow flows into the first frame body 11 from the water inlet end face, penetrates the first filler 211 in the primary filter layer, retains suspended solids and large-particle pollutants in the aquaculture tail water, and fully contacts the surface of the flexible biochemical filter layer 41 for first-level decomposition treatment; then, under the restriction of the flexible biochemical filter layer 41, the water flow flows downward into the second frame body 12, penetrates the second filler 212 in the middle filter layer, and performs second-level decomposition treatment at the biofilm layer formed by the second filler 212, and fully contacts the surface of the flexible biochemical filter layer 41 for first-level decomposition treatment at the surface of the flexible biochemical filter layer 41; then, under the restriction of the flexible biochemical filter layer 41, the water flow flows upward into the second frame body 12, penetrates the second filler 212, and performs second-level decomposition treatment at the biofilm layer formed by the second filler 212, and fully contacts the surface of the flexible biochemical filter layer 41 for first-level decomposition treatment at the surface of the flexible biochemical filter layer 41; and under the restriction of the flexible biochemical filter layer 41, the water flow flows upward into the first frame body 11, penetrates the first filler 211 in the primary filter layer, further retains suspended solids and large-particle pollutants in the aquaculture tail water, and fully contacts the surface of the flexible biochemical filter layer 41 for first-level decomposition treatment; finally, the water flow flows out from the water outlet end face.

[0091] Optionally, the water-permeable filler bag can be a mesh bag, and the mesh size of the mesh bag is configured to prevent the filler 21 from leaking out. The water-permeable filler bag can be provided with a handle or a hanging rope to facilitate replacement of the filler 21. The number of water-permeable filler bags can be adjusted according to specific conditions to ensure that the water-permeable filler bags are arranged in a triangular shape on the punched baffle 22.

[0092] Optionally, the punched baffle 22 has a mesh size of 18mm-22mm and a thickness of 0.5mm-3mm, which can effectively support the first filler 211, the second filler 212, and the third filler 213, facilitate the formation of the U-shaped water flow, and facilitate the backwashing assembly 3 to wash the upper filler 21. The punched baffle 22 is made of stainless steel and can be detachably connected to the frame body 1. For example, the punched baffle 22 can be fixed to the frame body 1 by hexagonal screw locks, or can be connected to the frame body 1 by other detachable connection methods such as conical pins and buckles, which are not limited in the present application.

[0093] In the above embodiment, the punched baffle 22 is arranged on the frame body 1 to form a plurality of water flow channels, and the water flow channels are arranged in a triangular shape.Figure 7 and Figure 8 The backwashing assembly 3 comprises a sealing unit, an aeration unit and a suction unit. The backwashing assembly 3 is arranged at the bottom of the frame body 1, which can significantly reduce the frequency of underwater operation and the need for replacing the filler 21, prolong the service life of the filler 21 and reduce the risk of system blockage.

[0094] Preferably, the sealing unit comprises a baffle 32 arranged on one side of the water inlet end face and a first support 31 for fixing the baffle 32, the baffle 32 is movably connected with the lower end of the first support 31, and the first support 31 is detachably connected with the frame body 1. The baffle 32 in the sealing unit is in the form of a movable door plate, which can block the water flow outside the frame body 1 from entering, and at the same time, the aeration unit can be maintained, disassembled, replaced and processed after being lifted out of the water. The arrangement of the baffle 32 is equivalent to forming a sump at the bottom of the frame body 1 to accommodate sludge, small particles and dirt after being treated by the filler 21, and the height of the baffle 32 can be reasonably adjusted according to the specific conditions of each structure in the backwashing assembly 3, which is not specifically limited.

[0095] Alternatively, the baffle 32 and the lower end of the first support 31 can be hingedly connected, which can be a hinge connection, or a pin shaft connection, a bolt connection or other movable connection methods. The first support 31 is detachably connected with the frame body 1, which can be a lock buckle connection, or a pin connection such as a conical pin, a buckle connection or other detachable connection methods. In some specific and preferred embodiments, the first support 31 is composed of a plurality of stainless steel pipes, one end of one of the stainless steel pipes is hingedly connected with the baffle 32, and the other end is fixedly connected with the frame body 1. The lower end of another stainless steel pipe corresponding to the first stainless steel pipe is detachably connected with the frame body 1.

[0096] Further, the baffle 32 is provided with a brush 33, which is inclined in the horizontal plane of the baffle 32, and is used to block the sludge outside the frame body 1 from directly entering the backwashing assembly 3 without being filtered. More preferably, the brush 33 is inclined at an angle of 45° in the horizontal plane of the baffle 32, the brush 33 can be a nylon wire, and the length of the brush 33 is 95-105 mm. Through the dynamic sealing structure and adaptive angle adjustment of the brush 33, the invasion of external sludge is effectively blocked.

[0097] Preferably, please refer to Figure 9, the aeration unit includes an aeration bracket 34 fixed on the first bracket 31, an aeration coil 35 arranged on the aeration bracket 34, and a ventilation device (not shown in the figure), the aeration coil 35 is connected with the ventilation device through an aeration hose 36, and is used for washing the residual pollutants in the frame body 1 and restoring the biofilm activity of the biochemical filter structure 4. It can be understood that, after the aeration coil 35 is connected with the ventilation device, high-pressure gas is output from the aeration coil 35 at the bottom, the shear force generated by the gas washing is used to strip the aged biofilm and large-particle pollutants attached to the surface of the filler, the dynamic balance of the porosity and the hydraulic conductivity of the filler is maintained, and the filtering and purifying efficiency of the filter dam device is restored. The number of the aeration units can be one or multiple, and the specific number can be reasonably adjusted according to the requirements of the frame body 1.

[0098] It can be understood that the ventilation device is arranged outside the water body, and the ventilation device includes but is not limited to a blower. The aeration hose 36 includes but is not limited to a PVC hose. In some specific embodiments, the pressure of the high-pressure gas output from the aeration coil 35 by the ventilation device is 0.2 MPa-0.3 MPa.

[0099] Preferably, the suction unit includes a suction port 37 arranged inside the baffle 32 and a centrifugal pump (not shown in the figure), the suction port 37 is connected with the centrifugal pump through a drain pipe 38, and is used for sucking the sludge accumulated after the backwashing. It can be understood that the centrifugal pump is arranged outside the water body, and the centrifugal pump is started when the ventilation device outside the water body stops running, so that the sludge and dirt accumulated after the backwashing are sucked through the arranged water suction port, thereby reducing the replacement frequency of the filler 21, prolonging the service life of the filler 21, reducing the possibility of filter dam blockage, and ensuring the air outlet effect. The sealing unit adopts a movable door plate form to regularly overhaul, disassemble and replace the backwashing aeration coil. The drain pipe 38 includes but is not limited to a PVC hose.

[0100] Correspondingly, the baffle 32 is further provided with through holes through which the aeration hose 36 and the drain pipe 38 pass, and the aeration hose 36 and the drain pipe 38 pass through the through holes and extend out of the skid-mounted backwashing filter device, so as to be communicated with the ventilation device and the centrifugal pump arranged outside the water body.

[0101] In the present application, the cleaning and maintenance of the filler 21 in the filter device can be achieved without completely emptying the water body of the three pools and two dams. The backwashing assembly 3 can significantly reduce the frequency of underwater operation and the need for filler replacement, thereby prolonging the service life of the filler and reducing the risk of system blockage. In combination with the directional suction of the bottom sludge by the axial flow pump, the physical blockage of the aeration coil 35 caused by long-term deposition of sludge can be effectively avoided, and the cost of microbial flora reconstruction caused by emptying the water body can be reduced. Through regular backwashing, the blockage probability of the filler 21 is reduced by more than 60%, and the service life can be optimized to 3-4 years.

[0102] Further, the backwashing assembly 3 further comprises an online monitoring device (not shown in the figure) connected with the ventilation equipment and / or axial flow pump. Through the feedback of monitoring data, intelligent automatic cleaning can be realized to timely remove the suspended solids, aged biological membrane and metabolic products accumulated on the surface of the filler 21, thereby significantly restoring the biological membrane activity and the hydraulic conductivity efficiency of the filter device. This process not only prevents blockage caused by excessive thickening of the biological membrane and reduces the water head loss, but also maintains the metabolic activity of the microbial community, thereby improving the water pollutant degradation and denitrification and phosphorus removal effects. In addition, backwashing can balance the biomass distribution in the filler 21, ensure the stability of the effluent water quality, prolong the service life of the filler 21, and reduce the operation and maintenance cost caused by blockage.

[0103] Further, the online monitoring device comprises a water level difference monitoring unit and / or a time period monitoring unit. The online monitoring device is preferably a water level difference monitoring unit and a time period monitoring unit. As the suspended solids and aged biological membrane accumulate in the pores of the filler 21, the through-flow velocity of the water flow in the filter device and the pollutant interception efficiency decrease. The backwashing assembly 3 automatically cleans through the intelligent automatic cleaning of the shore blower, and the cleaning frequency is controlled by time period and water level difference. When the water level difference exceeds the design value, the cleaning is automatically started. The cleaning frequency can also be manually set.

[0104] In some specific embodiments, the water level difference monitoring unit can be high-precision liquid level sensors, differential pressure sensors, etc. installed on the inlet end face and the outlet end face, respectively. The inlet and outlet water pressure difference is measured as a substitute indicator of the water level difference. A flowmeter can also be installed on one side of the tail water outlet end face to assist in monitoring the operation state of the system. The water level difference monitoring unit of the present application is not limited to the embodiments.

[0105] It should be noted that all functional units of the backwashing assembly 3 in the present application support non-destructive disassembly.

[0106] In some embodiments, please refer to Figure 1 and Figure 2The pry-mounted backwashing filter device further comprises a base dam 6 for fixing the frame body 1, and the backwashing assembly 3 is arranged on the base dam 6, and raw materials of the base dam 6 include but are not limited to concrete. The pry-mounted backwashing filter device in the application only needs to build a simple concrete foundation at the bottom of the frame body 1 to fix the frame body 1, effectively resists the influence of water flow scouring and external force, and ensures the stability of the filter dam device in long-term use.

[0107] In some embodiments, referring to Figure 3 and Figure 10 , the upper top surface of the frame body 1 is further provided with a movable top plate 7, and the top plate 7 has a mesh hole. The top plate 7 can be used as a walking channel and also helps to observe the blocking condition in the filter device. Generally, the weight of the top plate 7 is greater than 1.5 tons. Exemplarily, the top plate 7 can be a hot-dip galvanized steel grating, the mesh hole has a hole spacing of 28mm-32mm, and the thickness is 2cm-5cm. The number of the top plate 7 is reasonably set according to the size of the frame body 1 and the weight bearing performance of the top plate 7, and can be one, two or more, which is not limited in the application.

[0108] The pry-mounted backwashing filter device in the application has flexibility and modular construction, simple installation and operation, and regular backwashing and aeration functions, which can enhance the service life of filter material, reduce the blocking risk of the filter material 21, strengthen the pollutant removal efficiency of the filter material biofilm, facilitate the flushing and replacement of the backwashing pipe through the movable maintenance device of the backwashing aeration coil 35 and the first support 31, and reduce the later operation and maintenance cost.

[0109] Correspondingly, the application further provides a treatment method of aquaculture tail water, which adopts the pry-mounted backwashing filter device to treat the aquaculture tail water, and the treatment method comprises the following steps:

[0110] (1) installing at least one pry-mounted backwashing filter device at a preset position, so that the water inlet line is not higher than the first frame body 11;

[0111] (2) the aquaculture tail water enters the frame body 1 from the water inlet end face, flows in a U-shaped direction under the action of the biochemical filter structure 4, and sequentially flows through the first frame body 11, the second frame body 12, the third frame body 13, the second frame body 12 and the first frame body 11, is purified by the filter material 21 in each frame body, and the purified aquaculture tail water flows out from the water outlet end face;

[0112] (3) after the step (2) is operated for a preset time, the backwashing assembly 3 is started to remove the pollutants generated in the filtration and restore the biofilm activity of the biochemical filter structure 4.

[0113] After the aquaculture tail water is treated by using the above treatment method, taking the installation at the rear end of the sedimentation tank as an example, the average removal rate of suspended solids in the aquaculture tail water can be increased to greater than or equal to 15%, the average removal rate of COD Mn The average removal rate is increased to greater than or equal to 10%, the average removal rate of total nitrogen is increased to greater than or equal to 12%, and the average removal rate of total phosphorus is increased to greater than or equal to 16%.

[0114] The above only discloses a preferred embodiment of the present application, and of course cannot limit the scope of the rights of the present application, so the equivalent changes made according to the claims of the present application still fall within the scope of the present application.

Claims

1. A skid-mounted backflushing filter apparatus, characterized by The pry-mounted backwashing filter device is used for treating aquaculture tail water, and comprises a frame body, a filler assembly arranged in the frame body, a backwashing assembly arranged at the bottom of the frame body, and a biochemical filter structure partially penetrating the frame body. The frame body has a water inlet end face and a water outlet end face, wherein the frame body comprises a first frame body, a second frame body and a third frame body which are sequentially arranged in the vertical direction, the first frame body and the second frame body have mesh holes, and the third frame body has a water flow blocking surface. The biochemical filter structure is arranged in a direction perpendicular to the frame body and penetrates the middle part of the first frame body and the second frame body, and the biochemical filter structure comprises a flexible biochemical filter layer and a fixing frame, and the flexible biochemical filter layer is fixed to the middle part of the first frame body and the second frame body by the fixing frame. After the water flow enters the frame body from the water inlet end face, it sequentially flows through the first frame body, the second frame body, the third frame body, the second frame body and the first frame body, and then flows out from the water outlet end face in a U-shaped flow direction penetrating the frame body. The height of the biochemical filter structure is higher than the water inlet line, the flexible biochemical filter layer is a hollow polyester fiber membrane layer, the porosity of the hollow polyester fiber membrane layer is greater than or equal to 85%, the pore density is greater than or equal to 30 PPI, and the surface roughness Ra value is greater than or equal to 12.5 μm. The thickness of the flexible biochemical filter layer is 2%-4% of the width of the frame body. The thickness of the fixing frame is 2%-4% of the thickness of the flexible biochemical filter layer. The hollow polyester fiber membrane layer is a modified hollow polyester fiber membrane layer, and the preparation method of the modified hollow polyester fiber membrane layer comprises the following steps: The hollow polyester fiber membrane layer is immersed in an alkali solution at 40-60°C for 30-50 min, then immersed in an epichlorohydrin solution under a protective atmosphere, and triethylamine is added at 75-85°C for 2-4 h, and finally the reaction obtained hollow polyester fiber membrane layer is washed and dried. The concentration of the alkali solution is 0.8-1.2 mol / L. The concentration of the epichlorohydrin solution is 8-13 wt%, and the solvent of the epichlorohydrin solution is N,N-dimethylformamide and water, and the volume ratio of N,N-dimethylformamide to water is (8.5-9.5):

1. The weight ratio of triethylamine to the epichlorohydrin solution is 1:(0.1-0.3).

2. The skid-mounted backflushing filter apparatus of claim 1 wherein, The flexible biochemical filter layer has a water permeability of 500 L / (h·m 2 ), and a deformation rate in a hydrated state of less than or equal to 5%, so as to form a liquid level difference under the blocking effect of the flexible biochemical filter layer, and make the water flow in a U-shaped manner to the frame body and then flow out from the water outlet end face.

3. The skid-mounted backflushing filter apparatus of claim 1 wherein, The surface of the flexible biochemical filter layer forms a complex microbial flora, and the complex microbial flora decomposes ammonia nitrogen, nitrite and organic matter in the aquaculture tail water.

4. A skid-mounted backflushing filter device according to any one of claims 1-3, characterized in that, The filler assembly comprises a filler, a water-permeable filler bag for loading the filler, and a punched baffle for bearing the filler. The punched baffles are arranged between the first frame body and the second frame body, in the interior of the second frame body, between the second frame body and the third frame body, and between the third frame body and the backwashing assembly, and the water-permeable filler bags are stacked on the punched baffles. The filler includes a first filler, a second filler and a third filler, the first filler is arranged in the first frame body by the punching baffle to form a primary filter layer; the second filler is arranged in the second frame body by the punching baffle to form a middle filter layer; and the third filler is arranged in the third frame body by the punching baffle to form a deep filter layer.

5. A skid-mounted backflushing filter apparatus as claimed in any one of claims 1 to 3, wherein, The backwashing assembly includes a sealing unit, an aeration unit and a suction unit; The sealing unit includes a baffle arranged on one side of the water inlet end surface and a first support for fixing the baffle, the baffle is movably connected with the lower end of the first support, and the first support is detachably connected with the frame body; The aeration unit includes an aeration support, an aeration coil and a ventilation device, the aeration support is fixed on the first support, the aeration coil is arranged on the aeration support, and the aeration coil and the ventilation device are connected through an aeration hose, which is used for washing the residual pollutants in the frame body and restoring the biological membrane activity of the biochemical filter structure; The suction unit includes a suction port and an axial flow pump, the suction port is arranged on the inner side of the baffle, and the suction port is connected with the axial flow pump through a drain pipe, which is used for sucking and removing the accumulated slurry after backwashing.

6. The skid-mounted backflushing filter apparatus of claim 5 wherein, The baffle is provided with through holes through which the aeration hose and the drain pipe protrude out of the skid-mounted backwashing filter device; The baffle is provided with a brush, the brush is arranged obliquely on the plane of the baffle, and is used for blocking the sludge outside the frame body from directly entering the backwashing assembly without being filtered; The backwashing assembly further includes an online monitoring device connected with the ventilation device and / or the axial flow pump; The online monitoring device includes a water level difference monitoring unit and / or a time period monitoring unit.

7. The skid-mounted backflushing filter apparatus of claim 1 wherein, The setting height of the first frame body is not less than the water inlet line, the materials of the first frame body and the third frame body are metal, and the material of the second frame body is polyethylene; The setting height ratio of the first frame body, the second frame body and the third frame body is 1:(1.4-1.6):(0.5-0.7); The mesh size of the first frame body is larger than that of the second frame body, the mesh of the first frame body is a square mesh, and the mesh of the second frame body is a circular mesh.

8. The skid-mounted backflushing filter apparatus of claim 4 wherein, The first filler is used for treating surface pollutants at a depth of 0-32% underwater, the second filler is used for treating middle pollutants at a depth of 32%-80% underwater, and the third filler is used for treating bottom pollutants at a depth of 80%-100% underwater; The average particle size of the first filler is greater than or equal to that of the second filler, and the average particle size of the second filler is greater than or equal to that of the third filler.

9. The skid-mounted backflushing filter apparatus of claim 8 wherein, The average particle size of the first filler is 8cm-10cm, and the first filler is selected from oyster shells; The average particle size of the second filler is 5cm-8cm, and the second filler is selected from at least one of ceramic rings and ceramic particles; The third filler has an average particle size of 3-5 cm, and is selected from at least one of quartz ball and volcanic rock; The punching baffle has a mesh size of 18-22 mm and a thickness of 0.5-3 mm, and is detachably connected to the frame body.

10. The skid-mounted backflushing filter apparatus of claim 1 wherein, The pry-mounted backwashing filter device further comprises a base dam for fixing the frame body, and the backwashing assembly is arranged on the base dam. The upper top surface of the frame body is further provided with a movable top plate, and the top plate has a mesh; The frame body is provided with a reinforcing beam on the periphery.

11. A method of treating aquaculture effluent, characterized by, The pry-mounted backwashing filter device is used for treating aquaculture tail water, and the treatment method comprises the following steps: (1) At least one pry-mounted backwashing filter device is installed at a predetermined position, and the water inlet line is not higher than the first frame body; (2) The aquaculture tail water enters the frame body from the water inlet end face, and flows in a U-shaped manner under the action of the biochemical filter structure, sequentially flows through the first frame body, the second frame body, the third frame body, the second frame body and the first frame body, is purified by the filler in each frame body, and the purified aquaculture tail water flows out from the water outlet end face; (3) After a predetermined time of step (2), the backwashing assembly is started to remove the pollutants generated during filtration and restore the biological membrane activity of the biochemical filter structure.

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