CN114349254A

CN114349254A - Nitrogen and phosphorus interception and removal device for farmland drainage

Info

Publication number: CN114349254A
Application number: CN202111471090.9A
Authority: CN
Inventors: 王传沛
Original assignee: Xuzhou Dongjia Drainage And Irrigation Machinery Research Institute Co ltd
Current assignee: Xuzhou Dongjia Drainage And Irrigation Machinery Research Institute Co ltd
Priority date: 2021-12-03
Filing date: 2021-12-03
Publication date: 2022-04-15

Abstract

The invention discloses a nitrogen and phosphorus interception and removal device for farmland drainage, and relates to the technical field of farmland water pollution treatment. The machine comprises a machine body, wherein a liquid purifying discharge pipe is fixedly communicated with the bottom of the machine body, a lifting pump and a rotating motor are fixedly installed on the side surface of the machine body respectively, an aeration pump is fixedly installed on the top surface of the machine body, a flocculation cavity, an aeration cavity, a magnetic filter cavity, an air distribution ring cavity and a liquid distribution ring cavity which are mutually isolated are respectively arranged in the machine body, a medicine feeding hopper communicated with the flocculation cavity is fixedly installed at the top of the machine body, a drainage pipe communicated with the aeration cavity is fixedly communicated with the bottom of the flocculation cavity, a liquid distribution pipe is fixedly installed at the bottom of the drainage pipe, a pre-filtering mechanism is installed in the flocculation cavity, and an output shaft end of the rotating motor is in transmission connection with the pre-filtering mechanism. Through the design of the structures such as the magnetic filtering mechanism, the flocculation cavity and the like, the device can efficiently finish nitrogen and phosphorus removal operation of farmland discharged wastewater, and sewage can be fully flocculated in the flocculation cavity during the removal operation.

Description

Nitrogen and phosphorus interception and removal device for farmland drainage

Technical Field

The invention belongs to the technical field of farmland water pollution treatment, and particularly relates to a nitrogen and phosphorus interception and removal device for farmland drainage.

Background

In the drainage process of farmland, a large amount of nitrogen and phosphorus nutrition can be caused to enter rivers, lakes and reservoirs to cause eutrophication of water bodies and destroy the living environment of aquatic organisms, water environment deterioration can be caused seriously, the aquatic ecosystem is unbalanced, water pollution is serious day by day, the using function of the water bodies is reduced, and the contradiction of water resource shortage is also aggravated, in order to solve the problem, a patent document with the publication number of CN106396239 discloses a nitrogen and phosphorus removing device, the technical scheme utilizes the principle of magnet attraction to develop a novel nitrogen and phosphorus removing device, a flocculating agent is added into a tank body during working, wherein the added flocculating agent is combined with phosphate and an organic nitrogen compound to generate granular non-dissolved substances, a larger flocculating body is formed through chemical flocculation reaction accumulation, then iron powder is added into the tank body through an iron powder adding device and is combined with the flocculating body, the dispersion is on the flocculating constituent surface, when passing through the magnetism filter screen, can the adhesion on the magnetism filter screen, after the sewage rethread submergence formula milipore filter after preliminary purification filters, by the drain pipe discharge, but above-mentioned technical scheme is when nitrogen phosphorus is got rid of, and the material of holding back is piled up easily or is remained on the magnetism filter screen, and then influences the filtering quality and the filter effect of magnetism filter screen, and during the use, above-mentioned technical scheme is not convenient for realize the filtration and the purification operation of farmland emission sewage.

Disclosure of Invention

The invention aims to provide a nitrogen and phosphorus interception and removal device for farmland drainage, which solves the problems that the magnetic filter screen of the traditional nitrogen and phosphorus interception and removal device for farmland drainage is easy to block and accumulate materials to influence the filtering performance and is inconvenient for filtering and purifying sewage through the design of a magnetic filter mechanism and a pre-filtering mechanism.

In order to solve the technical problems, the invention is realized by the following technical scheme:

the invention relates to a nitrogen and phosphorus interception and removal device for farmland drainage, which comprises a machine body, wherein the bottom of the machine body is fixedly communicated with a liquid purification drainage pipe, the side surfaces of the machine body are respectively and fixedly provided with a lifting pump and a rotary motor, the top surface of the machine body is fixedly provided with an aeration pump, the interior of the machine body is respectively provided with a flocculation cavity, an aeration cavity, a magnetic filtration cavity, an air distribution annular cavity and a liquid distribution annular cavity which are mutually isolated, the top of the machine body is fixedly provided with a medicine feeding hopper communicated with the flocculation cavity, the bottom of the flocculation cavity is fixedly communicated with a drainage pipe communicated with the aeration cavity, the bottom of the drainage pipe is fixedly provided with a liquid distribution pipe, the interior of the flocculation cavity is provided with a pre-filtration mechanism, the output shaft end of the rotary motor is in transmission connection with the pre-filtration mechanism, the interior of the magnetic filtration cavity is provided with a magnetic filtration mechanism matched with the liquid distribution pipe, and a waste bearing box is movably arranged in the machine body and corresponds to the position below the magnetic filtration mechanism, the one end and the fixed intercommunication in magnetism strain chamber of elevator pump inlet, the one end and the fixed intercommunication in branch liquid ring chamber of elevator pump outlet, the one end and the fixed intercommunication in branch gas ring chamber of aeration pump gas outlet, the internally mounted in flocculation chamber has a set of filter core module that is circumference array distribution, and is a set of the week side of filter core module all with divide the fixed intercommunication in liquid ring chamber, a set of aeration pipe that is circumference array distribution and all with branch gas ring chamber intercommunication, every are installed to the inner wall in aeration chamber the aeration hole has been seted up to the impartial distance in surface of aeration pipe.

Preferably, the clean liquid calandria reaches the intercommunication department of discharge tube and flocculation chamber all is provided with the valve, the fixed ration baiting valve that is provided with in intercommunication department of medicine hopper and flocculation chamber, a plurality of branch flow holes that are linear array distribution and with the complex of magnetic filter mechanism are seted up to the bottom of branch liquid pipe.

Preferably, the pre-filtering mechanism comprises a top barrel and a bottom barrel respectively, the peripheral sides of the top barrel and the bottom barrel are fixedly connected with the machine body, the peripheral sides of the top barrel are fixedly communicated with a water inlet pipe, the peripheral sides of the water inlet pipe are fixedly connected with the machine body, a pre-filtering rotary barrel is rotatably connected between the opposite surfaces of the top barrel and the bottom barrel, the output shaft end of the rotating motor is in transmission connection with the pre-filtering rotary barrel, a group of stirring modules distributed in a linear array manner are fixedly mounted on the peripheral sides of the pre-filtering rotary barrel, a plurality of groups of water filtering outer holes distributed in a circumferential array manner are formed in the peripheral sides of the pre-filtering rotary barrel, a transmission motor is fixedly mounted at the top of the top barrel, a lifting shaft is fixedly mounted at the output shaft end of the transmission motor, a spiral lifting filter disc is fixedly mounted on the peripheral sides of the lifting shaft, and the peripheral sides of the spiral lifting filter disc are respectively attached to the top barrel, the pre-filtering rotary barrel and the bottom barrel, the spiral material lifting filter element is characterized in that water filtering inner holes are uniformly distributed in the surface of the spiral material lifting filter element, a waste filtering discharge pipe is fixedly communicated with the peripheral side face of the top cylinder, and a high-pressure fan with an air outlet direction opposite to the waste filtering discharge pipe is further fixedly installed on the peripheral side face of the top cylinder.

Preferably, the pre-filtering rotary cylinder is of a hollow cylindrical structure with two open ends, the bottom end of the bottom cylinder is closed, the upper end of the bottom cylinder is open, the aperture of the water filtering inner hole is the same as that of the water filtering outer hole, and the axis of the water filtering outer hole is perpendicular to that of the pre-filtering rotary cylinder.

Preferably, strain useless calandria and be the downward sloping setting just strain the axis of useless calandria and the contained angle of level line and be 35, the axis of inlet tube is perpendicular with the axis of top cylinder.

Preferably, the stirring module comprises a mounting ring, and a group of stirring rods distributed in a circumferential array is fixedly mounted on the peripheral side surface of the mounting ring.

Preferably, the magnetic filter mechanism comprises a driving motor, a driving roller, a driven roller and an annular conveying belt respectively, one surface of the driving motor is fixedly connected with the machine body, two ends of the driving roller and the driven roller are rotatably connected with the machine body, an output shaft end of the driving motor is fixedly connected with the driving roller, the peripheral sides of the driving roller and the driven roller are respectively connected with the annular conveying belt, a magnetic seat is arranged on the inner side of the annular conveying belt, the top surface of the magnetic seat is in sliding fit with the annular conveying belt, the magnetic seat is of a J-shaped structure, a baffle plate is installed on the surface of the annular conveying belt at equal intervals, through holes are uniformly distributed on the surface of the baffle plate, and the diameter of each through hole is 0.5-0.7 times of the diameter of the water filtering inner hole.

Preferably, the filter core module includes the registration arm, all sides and organism fixed connection of registration arm, all sides fixed intercommunication of registration arm has the feed liquor branch pipe, the one end and the fixed intercommunication in branch liquid ring chamber of feed liquor branch pipe, the inner wall threaded connection of registration arm has a packing section of thick bamboo, a plurality of groups are the liquid hole that permeates that the circumference needle distributes offered to the bottom of packing section of thick bamboo, the inside packing of packing section of thick bamboo has the filter material, the aperture in liquid hole is the same with the aperture of through-hole, a plurality of feed liquor strip holes that are circumference array distribution are offered to all sides of packing section of thick bamboo and the position that corresponds the feed liquor branch pipe.

The invention has the following beneficial effects:

1. according to the device, through the design of the structures such as the magnetic filtering mechanism and the flocculation cavity, nitrogen and phosphorus removal operation of wastewater discharged from a farmland can be efficiently completed, sewage can be sufficiently flocculated in the flocculation cavity during removal operation, the iron powder and flocculating agent can be supplemented into the wastewater by the medicine adding hopper, nitrogen and phosphorus impurities after flocculation can be sufficiently intercepted by the magnetic filtering mechanism, the device changes a static structure of the traditional magnetic filtering mechanism into a movable structure, when magnetic filtering operation is performed, the sewage to be filtered can be discharged through the annular conveying belt under the action of gravity, nitrogen and phosphorus waste materials can be filtered out under the action of the annular conveying belt, and through the conversion of the filtering structure, the filtering material is effectively prevented from being blocked on the filtering structure, and through the realization of an anti-blocking effect, the high filtering performance of the magnetic filtering mechanism is favorably ensured.

2. According to the invention, through the design of the filter element module and the aeration cavity, on one hand, the efficient filtering and purifying operation of the wastewater can be realized by utilizing the filler filtering principle, on the other hand, the bacteria content of the wastewater can be effectively reduced through aeration, on the one hand, the double filtering operation of the wastewater can be performed through the design of the pre-filtering mechanism, and on the other hand, the filtered waste can be quickly discharged during filtering.

Of course, it is not necessary for any product in which the invention is practiced to achieve all of the above-described advantages at the same time.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic sectional view of a nitrogen and phosphorus interception and removal device for farmland drainage;

FIG. 2 is a schematic view of a portion A of FIG. 1;

FIG. 3 is a schematic view of a portion of the enlarged structure at B in FIG. 1;

FIG. 4 is a schematic view of a portion of the enlarged structure at C in FIG. 1;

FIG. 5 is an enlarged view of a portion of FIG. 1 at D;

FIG. 6 is a schematic view of the structure of the waste filtering calandria and the drug feeding funnel;

FIG. 7 is a schematic structural view of a top and bottom cartridge;

FIG. 8 is a schematic cross-sectional view of a filter cartridge module

In the drawings, the components represented by the respective reference numerals are listed below:

1. a body; 2. a liquid-purifying discharge pipe; 3. a lift pump; 4. a rotating electric machine; 5. an aeration pump; 6. a flocculation chamber; 7. an aeration cavity; 8. a magnetic filter cavity; 9. a gas distribution ring cavity; 10. a liquid separating ring cavity; 11. a medicine feeding hopper; 12. a drain pipe; 13. a liquid separating pipe; 14. a waste-bearing box; 15. a filter element module; 16. an aeration pipe; 17. a top cylinder; 18. a bottom cylinder; 19. a water inlet pipe; 20. a pre-filtering rotary cylinder; 21. a stirring module; 22. water filtering outer holes; 23. a drive motor; 24. a lift shaft; 25. a spiral material lifting filter disc; 26. filtering an inner hole; 27. filtering the waste discharge pipe; 28. a high pressure fan; 29. an endless conveyor belt; 30. a magnetic base; 31. a striker plate; 32. a positioning tube; 33. a liquid inlet branch pipe; 34. a packing cylinder; 35. a liquid permeable hole; 36. and (4) liquid inlet strip holes.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-8, the invention is a nitrogen and phosphorus interception and removal device for farmland drainage, comprising a machine body 1, wherein the bottom of the machine body 1 is fixedly communicated with a liquid purification drainage pipe 2, the side surfaces of the machine body 1 are respectively and fixedly provided with a lift pump 3 and a rotating motor 4, the top surface of the machine body 1 is fixedly provided with an aeration pump 5, the interior of the machine body 1 is respectively provided with a flocculation cavity 6, an aeration cavity 7, a magnetic filtration cavity 8, a gas distribution annular cavity 9 and a liquid distribution annular cavity 10 which are isolated from each other, the top of the machine body 1 is fixedly provided with a dosing hopper 11 communicated with the flocculation cavity 6, the communication part of the dosing hopper 11 and the flocculation cavity 6 is fixedly provided with a quantitative discharging valve, when in use, the dosing hopper 11 stores a mixture of flocculation medicament and iron powder, and the quantitative discharging valve is used for quantitatively discharging the mixed medicament in the dosing hopper 11;

one end of a liquid inlet of the lifting pump 3 is fixedly communicated with the magnetic filter cavity 8, one end of a liquid outlet of the lifting pump 3 is fixedly communicated with the liquid separating ring cavity 10, and one end of a gas outlet of the aeration pump 5 is fixedly communicated with the gas separating ring cavity 9;

a drainage pipe 12 communicated with the aeration cavity 7 is fixedly communicated with the bottom of the flocculation cavity 6, a liquid distribution pipe 13 is fixedly installed at the bottom of the drainage pipe 12, valves are arranged at the communication part of the liquid purification drainage pipe 2 and the machine body 1 and the communication part of the drainage pipe 12 and the flocculation cavity 6, a plurality of shunting holes which are distributed in a linear array mode and matched with the magnetic filter mechanism are formed in the bottom of the liquid distribution pipe 13, the distribution area of the shunting holes is matched with the width of the annular conveying belt 29, and the liquid distribution pipe 13 is arranged above the annular conveying belt 29;

a pre-filtering mechanism is arranged in the flocculation cavity 6, and the output shaft end of the rotating motor 4 is in transmission connection with the pre-filtering mechanism;

the pre-filtering mechanism comprises a top barrel 17 and a bottom barrel 18 respectively, the peripheral sides of the top barrel 17 and the bottom barrel 18 are fixedly connected with the machine body 1, the peripheral side of the top barrel 17 is fixedly communicated with a water inlet pipe 19, the peripheral side of the water inlet pipe 19 is fixedly connected with the machine body 1, the open end of the water inlet pipe 19 extends to the outside of the machine body 1, the axis of the water inlet pipe 19 is vertical to the axis of the top barrel 17, and before the pre-filtering mechanism is used, one end of the water inlet pipe 19 is communicated with a drainage pipeline of a farmland;

a pre-filtering barrel 20 is rotatably connected between the opposite surfaces of the top barrel 17 and the bottom barrel 18, the pre-filtering barrel 20 is of a hollow cylindrical structure with two open ends, the bottom end of the bottom barrel 18 is closed and the upper end is open, the top end of the top barrel 17 is closed and the lower end is open, the output shaft end of the rotating motor 4 is in transmission connection with the pre-filtering barrel 20, a driven bevel gear matched with the rotating motor 4 is fixedly installed on the peripheral side surface of the pre-filtering barrel 20, and a driving bevel gear matched with the driven bevel gear is fixedly installed on the peripheral side surface of the output shaft of the rotating motor 4;

a group of stirring modules 21 distributed in a linear array are fixedly installed on the peripheral side surface of the pre-filtering rotary cylinder 20, each stirring module 21 comprises an installation ring, and a group of stirring rods distributed in a circumferential array are fixedly installed on the peripheral side surface of the installation ring;

the periphery of the pre-filtering rotary cylinder 20 is provided with a plurality of groups of water filtering outer holes 22 distributed in a circumferential array, the axis of each water filtering outer hole 22 is perpendicular to the axis of the pre-filtering rotary cylinder 20, the top of the top cylinder 17 is fixedly provided with a transmission motor 23, the output shaft end of the transmission motor 23 is fixedly provided with a lifting shaft 24, the periphery of the lifting shaft 24 is fixedly provided with a spiral material lifting filter sheet 25, the periphery of the spiral material lifting filter sheet 25 is respectively attached to the top cylinder 17, the pre-filtering rotary cylinder 20 and the bottom cylinder 18, the surface of the spiral material lifting filter sheet 25 is uniformly provided with water filtering inner holes 26, the aperture of each water filtering inner hole 26 is the same as the aperture of the water filtering outer hole 22, the periphery of the top cylinder 17 is fixedly communicated with a waste filtering discharge pipe 27, the waste filtering discharge pipe 27 is arranged in a downward inclination manner, the included angle between the axis of the waste filtering discharge pipe 27 and the horizontal line is 35 degrees, the periphery of the top cylinder 17 is also fixedly provided with a high-pressure fan 28 with an air outlet direction right facing the waste filtering discharge pipe 27, when the high-pressure air filter is used, the high-pressure air blower 28 discharges air at high pressure, and the high-pressure air blower 28 is used for improving the outflow rate of the filtered waste from the filtered waste discharge pipe 27;

a magnetic filter mechanism matched with the liquid distribution pipe 13 is arranged in the magnetic filter cavity 8, and a waste bearing box 14 is movably arranged in the machine body 1 and at a position corresponding to the lower part of the magnetic filter mechanism;

the magnetic filter mechanism comprises a driving motor, a driving roller, a driven roller and an annular conveying belt 29 respectively, the annular conveying belt 29 is made of rubber impermeable materials, one surface of the driving motor is fixedly connected with the machine body 1, two ends of the driving roller and the driven roller are rotatably connected with the machine body 1, the output shaft end of the driving motor is fixedly connected with the driving roller, the peripheral sides of the driving roller and the driven roller are connected with the annular conveying belt 29, a magnetic seat 30 is arranged on the inner side of the annular conveying belt 29, the top surface of the magnetic seat 30 is in sliding fit with the annular conveying belt 29, the magnetic seat 30 is essentially a magnet, the magnetic seat 30 is of a J-shaped structure, baffle plates 31 are equidistantly arranged on the surface of the annular conveying belt 29, through holes are uniformly distributed on the surface of each baffle plate 31, and the diameter of the through holes is 0.5 times of the aperture of the water filtering inner hole 26;

the internally mounted of flocculation chamber 6 has a set of filter core module 15 that is the circumference array and distributes, and the week side of a set of filter core module 15 all with divide the fixed intercommunication of liquid ring chamber 10, and a set of aeration pipe 16 that is the circumference array and distribute and all communicate with branch gas ring chamber 9 is installed to the inner wall of aeration chamber 7, and the aeration hole has been seted up to the equal equidistance in surface of every aeration pipe 16.

Wherein, filter core module 15 includes registration arm 32, the week side and the 1 fixed connection of organism of registration arm 32, the fixed intercommunication of week side of registration arm 32 has liquid inlet branch pipe 33, the one end and the fixed intercommunication of branch liquid ring chamber 10 of liquid inlet branch pipe 33, the inner wall threaded connection of registration arm 32 has a packing section of thick bamboo 34, a plurality of groups have been seted up to the bottom of packing section of thick bamboo 34 and have the liquid hole 35 that the circumference needle distributes, the inside packing of packing section of thick bamboo 34 has the filter material, the aperture that passes through liquid hole 35 is the same with the aperture of through-hole, a plurality of liquid inlet strip holes 36 that are circumference array distribution are seted up to the week side of packing section of thick bamboo 34 and the position that corresponds liquid inlet branch pipe 33.

The working principle is as follows: before use, the water inlet pipe 19 is communicated with a drainage pipeline of a farmland, the clean liquid discharge pipe 2 is communicated with next-stage treatment equipment of the farmland water, when in use, the rotating motor 4 and the transmission motor 23 work synchronously, after the transmission motor 23 works, the spiral material lifting filter sheet 25 is driven to lift materials upwards at a set speed, after the rotating motor 4 works, the pre-filtering rotary drum 20 is driven to rotate at a set speed, in the working process of the rotating motor 4, the mixed medicines in the medicine adding hopper 11 are periodically and quantitatively discharged, after the mixed medicines are added, nitrogen and phosphorus elements in the sewage in the flocculation cavity 6 are flocculated into clusters, the clustered clusters contain iron powder, so that the magnetic filtering mechanism can conveniently filter and adsorb the mixed medicines, in the non-working period of the medicine adding hopper 11, the driving motor, the lifting pump 3 and the aeration pump 5 work synchronously, after the driving motor works, the annular conveying belt 29 is driven to rotate clockwise, after the lifting pump 3 works, the magnetically filtered wastewater is lifted to the aeration cavity 7, after the aeration pump 5 works, aeration is carried out in the aeration cavity 7, after the annular conveying belt 29 works clockwise, the flocculated waste materials are conveyed to one side of the waste bearing box 14, and the purified liquid flows out through the annular conveying belt 29.

In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The preferred embodiments of the invention disclosed above are intended to be illustrative only. The preferred embodiments are not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. The utility model provides a nitrogen phosphorus interception remove device for farmland drainage, includes organism (1), the fixed intercommunication in bottom of organism (1) has net liquid calandria (2), its characterized in that: the side of the machine body (1) is respectively and fixedly provided with a lifting pump (3) and a rotating motor (4), the top surface of the machine body (1) is fixedly provided with an aeration pump (5), the inside of the machine body (1) is respectively provided with a flocculation cavity (6), an aeration cavity (7), a magnetic filtration cavity (8), an air distribution ring cavity (9) and a liquid distribution ring cavity (10) which are isolated from each other, the top of the machine body (1) is fixedly provided with a dosing hopper (11) communicated with the flocculation cavity (6), the bottom of the flocculation cavity (6) is fixedly communicated with a drainage pipe (12) communicated with the aeration cavity (7), the bottom of the drainage pipe (12) is fixedly provided with a liquid distribution pipe (13), the inside of the flocculation cavity (6) is provided with a pre-filtration mechanism, the output shaft end of the rotating motor (4) is in transmission connection with the pre-filtration mechanism, the inside of the magnetic filtration cavity (8) is provided with a magnetic filtration mechanism matched with the liquid distribution pipe (13), the utility model discloses a sewage treatment device, including organism (1), the one end and the fixed intercommunication in magnetism filtration chamber (8) of elevator pump (3) inlet, the one end and the fixed intercommunication in branch gas ring chamber (10) of elevator pump (3) liquid outlet of organism just corresponding magnetism filtration mechanism below have a waste holding box (14), the one end and the fixed intercommunication in branch gas ring chamber (9) of elevator pump (3) inlet, the internally mounted of flocculation chamber (6) has a set of filter core module (15) that are circumference array distribution, and is a set of the week side of filter core module (15) all with divide fixed intercommunication in liquid ring chamber (10), a set of aeration pipe (16) that are circumference array distribution and all with branch gas ring chamber (9) intercommunication, every are installed to the inner wall in aeration chamber (7) the aeration hole has all been seted up to the surface equidistance of aeration pipe (16).

2. The nitrogen and phosphorus interception and removal device for farmland drainage according to claim 1, characterized in that the connection between the clean liquid drainage pipe (2) and the machine body (1) and the connection between the drainage pipe (12) and the flocculation chamber (6) are provided with valves, the connection between the chemical feeding hopper (11) and the flocculation chamber (6) is fixedly provided with a quantitative blanking valve, and the bottom of the liquid distribution pipe (13) is provided with a plurality of flow distribution holes which are distributed in a linear array and matched with the magnetic filtration mechanism.

3. The nitrogen and phosphorus intercepting and removing device for farmland drainage according to claim 1, characterized in that the pre-filtering mechanism comprises a top cylinder (17) and a bottom cylinder (18), the peripheral sides of the top cylinder (17) and the bottom cylinder (18) are fixedly connected with the machine body (1), the peripheral side of the top cylinder (17) is fixedly communicated with a water inlet pipe (19), the peripheral side of the water inlet pipe (19) is fixedly connected with the machine body (1), a pre-filtering rotary cylinder (20) is rotatably connected between the opposite surfaces of the top cylinder (17) and the bottom cylinder (18), the output shaft end of the rotating motor (4) is in transmission connection with the pre-filtering rotary cylinder (20), a group of stirring modules (21) distributed in a linear array are fixedly installed on the peripheral side of the pre-filtering rotary cylinder (20), and a plurality of groups of outer water filtering holes (22) distributed in a circumferential array are formed on the peripheral side of the pre-filtering rotary cylinder (20), the top fixed mounting of top cylinder (17) has drive motor (23), the output shaft fixed mounting of drive motor (23) has lift axle (24), the all side fixed mounting of lift axle (24) has spiral to carry material filter (25), the all side of spiral to carry material filter (25) laminates with top cylinder (17), pre-filtering rotary drum (20) and end section of thick bamboo (18) respectively, the surperficial equipartition of spiral to carry material filter (25) has drainage hole (26), the all side fixed intercommunication of top cylinder (17) has strain useless calandria (27), the all side of top cylinder (17) still fixed mounting have the air-out direction just to high pressure positive blower (28) of straining useless calandria (27).

4. The nitrogen and phosphorus interception and removal device for farmland drainage according to claim 3, characterized in that the pre-filtering rotary cylinder (20) is a hollow cylindrical structure with two open ends, the bottom end of the bottom cylinder (18) is closed and the upper end is open, the bore diameter of the water filtering inner hole (26) is the same as that of the water filtering outer hole (22), and the axis of the water filtering outer hole (22) is perpendicular to the axis of the pre-filtering rotary cylinder (20).

5. The nitrogen and phosphorus intercepting and removing device for farmland drainage according to claim 3, characterized in that the filtering waste discharging pipe (27) is arranged in a downward inclination manner, the included angle between the axis of the filtering waste discharging pipe (27) and the horizontal line is 35 degrees, and the axis of the water inlet pipe (19) is vertical to the axis of the top cylinder (17).

6. The nitrogen and phosphorus interception and removal device for farmland drainage according to claim 3, wherein the stirring module (21) comprises a mounting ring, and a group of stirring rods distributed in a circumferential array are fixedly mounted on the peripheral side surface of the mounting ring.

7. The nitrogen and phosphorus interception and removal device for farmland drainage according to claim 1, characterized in that the magnetic filter mechanism comprises a driving motor, a driving roller, a driven roller and an annular conveyer belt (29), one surface of the driving motor is fixedly connected with the machine body (1), two ends of the driving roller and the driven roller are rotatably connected with the machine body (1), an output shaft end of the driving motor is fixedly connected with the driving roller, the peripheral side surfaces of the driving roller and the driven roller are respectively connected with the annular conveyer belt (29), a magnetic seat (30) is arranged on the inner side of the annular conveyer belt (29), the top surface of the magnetic seat (30) is in sliding fit with the annular conveyer belt (29), the magnetic seat (30) is of a J-shaped structure, baffle plates (31) are installed on the surface of the annular conveyer belt (29) at equal intervals, through holes are uniformly distributed on the surface of the baffle plates (31), the diameter of the through hole is 0.5 to 0.7 times of the aperture of the water filtering inner hole (26).

8. The nitrogen and phosphorus interception and removal device for farmland drainage according to claim 1, the filter element module (15) comprises a positioning pipe (32), the peripheral side surface of the positioning pipe (32) is fixedly connected with the machine body (1), the side surface of the positioning pipe (32) is fixedly communicated with a liquid inlet branch pipe (33), one end of the liquid inlet branch pipe (33) is fixedly communicated with the liquid separating ring cavity (10), the inner wall of the positioning pipe (32) is connected with a packing cylinder (34) in a threaded manner, the bottom of the packing cylinder (34) is provided with a plurality of groups of liquid permeation holes (35) distributed in a circumferential needle manner, the inside of the filler cylinder (34) is filled with filter materials, the aperture of the liquid permeation hole (35) is the same as that of the through hole, and a plurality of liquid inlet strip holes (36) distributed in a circumferential array are formed in the peripheral side surface of the filling cylinder (34) and correspond to the positions of the liquid inlet branch pipes (33).