CN111977888B - Biochemical treatment system for extracting N-methyl pyrrolidone from wastewater - Google Patents

Abstract

The invention relates to a biochemical treatment system for extracting N-methylpyrrolidone from wastewater, which comprises a cooling pipeline, a comprehensive regulating tank, an anaerobic tank, a hydrolysis acidification tank, a contact oxidation tank and a secondary sedimentation tank, wherein the cooling pipeline conveys the wastewater into the comprehensive regulating tank, a first aeration device and a stirring device are arranged in the comprehensive regulating tank, a baffle device is arranged in the anaerobic tank, and a plurality of baffle plates which are arranged in a staggered manner are arranged at the bottom of the hydrolysis acidification tank; the contact oxidation pond is internally provided with a second aeration device, a microorganism packing layer and a water distribution device from bottom to top, the bottom of the secondary sedimentation tank is respectively connected with a sludge delivery pump and a sludge reflux pump through a three-way pipe, the outlet end of the sludge reflux pump is connected with a reflux pipe, and the reflux pipe is connected with the hydrolysis acidification tank. Adopt cooling line to carry out water cooling treatment to the well waste water that enters into biochemical treatment pond, through waste water and baffling cooling plate abundant contact, reach the effect of waste water rapid cooling.

Description

Biochemical treatment system for extracting N-methyl pyrrolidone from wastewater

Technical Field

The invention belongs to the technical field of wastewater treatment, and particularly relates to a biochemical treatment system for extracting N-methylpyrrolidone from wastewater.

Background

A large amount of comprehensive chemical organic wastewater is discharged every day by general chemical enterprises, such as absorption tower wastewater, workshop flushing wastewater, wastewater during tests and the like, and some of the wastewater is discharged from high-temperature production equipment, so that cooling treatment is required before treatment, otherwise, the activity of microorganisms in a biochemical pool is influenced, and a small amount of factory domestic wastewater exists. The main pollution factors of the comprehensive chemical wastewater are CODER and ammonia nitrogen, and the characteristic pollutant components are mainly organic compounds such as organic solvent NMP and the like. The wastewater can be discharged only when reaching the standard of a connecting pipe of a sewage treatment plant after being treated, the conventional biochemical treatment system has a simple structure, the degradation speed of organic matters in a treatment tank is low, and the water flow in a reaction tank is relatively simple, so that the volume utilization rate in the reaction tank is low, the wastewater treatment capacity is influenced, the interception capacity of biosolids cannot be ensured, microorganisms in one reactor are easy to grow in the same region, and therefore, the high-efficiency wastewater biochemical treatment system is needed.

Disclosure of Invention

The invention aims at the problems and discloses a biochemical treatment system for extracting N-methyl pyrrolidone from wastewater.

The specific technical scheme is as follows:

a biochemical treatment system for extracting N-methyl pyrrolidone from wastewater comprises a cooling pipeline, a comprehensive adjusting tank, an anaerobic tank, a hydrolysis acidification tank, a contact oxidation tank and a secondary sedimentation tank, the cooling pipeline conveys the wastewater into a comprehensive adjusting tank, a first aeration device and a stirring device are arranged in the comprehensive adjusting tank, the collected wastewater is stirred and homogenized, wastewater is injected into an anaerobic tank through a first conveying pipe and a first lifting pump on one side of a comprehensive adjusting tank, a baffling device for changing the flow state of water flow is arranged in the anaerobic tank, the anaerobic tank is matched with a second lifting pump through a second conveying pipe to inject the wastewater into the hydrolysis acidification tank, a plurality of baffle plates which are arranged in a staggered way are arranged at the bottom of the hydrolysis acidification tank, the hydrolysis acidification tank is matched with a third lift pump through a third conveying pipe to convey the wastewater to the contact oxidation tank; the contact oxidation pond is provided with a second aeration device, a microorganism packing layer and a water distribution device from bottom to top, the contact oxidation pond is used for conveying waste water to a secondary sedimentation tank by matching a fourth conveying pipe with a fourth lifting pump, the secondary sedimentation tank is a vertical sedimentation tank, the bottom of the secondary sedimentation tank is respectively connected with a sludge conveying pump and a sludge reflux pump through a three-way pipe, the outlet end of the sludge reflux pump is connected with a reflux pipe, the reflux pipe is connected with a hydrolysis acidification tank, so that the sludge reflux pump can reflux precipitated sludge to the hydrolysis acidification tank, and the sludge conveying pump conveys the sludge to the sludge tank through a pipeline.

Furthermore, the cooling pipeline comprises a cooling sleeve and a plurality of baffling cooling plates arranged in the cooling sleeve, one end of the cooling sleeve is connected with the comprehensive regulating tank through a pipeline, the side wall of the cooling sleeve is of a hollow structure, two ends of the inner cavity of the cooling sleeve are provided with sealing baffles, the two sealing baffles separate the inner cavity of the cooling sleeve into two independent cavities, one side of each cavity is provided with a water inlet pipe and a water outlet pipe which are respectively connected with the water inlet pipe and the water outlet pipe, the water inlet pipe and the water outlet pipe are connected with a circulating pipeline, the circulating pipeline is connected with a water tank, a circulating pump is arranged on the circulating pipeline, and a plurality of connecting pipes are symmetrically arranged on two sides of the inner wall of the cooling sleeve; it is a plurality of the baffling cooling plate is vertical setting and transverse arrangement sets up in cooling jacket's inboard, and a plurality of baffling cooling plate is improved level and is run through and be equipped with a plurality of dead levers, dead lever both ends and cooling jacket's both ends inner wall fixed connection, all be equipped with water flow channel in the inner chamber of baffling cooling plate, and baffling cooling plate's both sides are equipped with a plurality of water pipe head, water pipe head with water flow channel intercommunication, and the position of water pipe head is corresponding with the connecting pipe position of cooling jacket inner wall both sides, and fixed connection between a plurality of water pipe head and a plurality of connecting pipes.

Further, baffling cooling plate includes casing and lid, lid and casing all are bow-shaped structure, and the lid passes through bolt and nut to be fixed in one side of casing and seal the casing inner chamber, and top-down sets up a plurality ofly in the casing rivers passageway, and every rivers passageway all is the setting of S type.

Furthermore, agitating unit is including setting up the first mount in comprehensive processing pond top, rotating the (mixing) shaft that sets up at first mount center and setting up the stirring vane on the (mixing) shaft.

Furthermore, the baffle device comprises a plurality of second fixing frames, a driving motor, a positioning shaft and baffle ring plates, wherein the baffle ring plates are fixedly arranged at the bottom of the anaerobic tank in a circular ring shape, the diameter of each baffle ring plate is gradually increased from inside to outside, the second fixing frames are arranged above the anaerobic tank, the driving motor is fixedly arranged on the second fixing frames, the center of each second fixing frame is vertically provided with the positioning shaft, the lower end of the positioning shaft is fixed at the bottom of the anaerobic tank and is positioned at the center of the baffle ring plates, the positioning shaft is a hollow shaft, the upper end of the positioning shaft is connected with the first conveying pipe, the surface of the lower end of the positioning shaft is provided with a plurality of through holes, the positioning shaft is rotatably provided with a rotating sleeve, the outer wall of the rotating sleeve is rotatably connected with the second fixing frames through a bearing, and the outer wall of the rotating sleeve is in transmission connection with the output shaft of the driving motor through the matching of a driving wheel, the rotary sleeve is horizontally provided with a rotary plate of a circular structure at the bottom, the rotary plate is provided with a plurality of rotary discs of a circular structure at the bottom, the rotary discs are all of hollow round table structures, the diameter of each rotary disc is gradually reduced and increased from inside to outside, and the rotary discs and the baffle ring plates are arranged in a staggered mode.

Furthermore, a plurality of air holes are formed in the rotating plate.

Furthermore, spiral convex strips distributed along the center of the rotating disc are arranged on the inner wall of the rotating disc.

Furthermore, the first aeration device and the second aeration device respectively comprise an aeration ring pipe, a plurality of aeration heads respectively arranged on the aeration ring pipe and a blower communicated with the aeration ring pipe.

Furthermore, an aeration branch pipe is connected to an aeration ring pipe of the second aeration device, and aeration holes are formed in the aeration branch pipe and are arranged in the microorganism packing layer.

Furthermore, the water distribution device comprises a plurality of water distribution pipes which are transversely arranged above the contact oxidation tank, the water distribution pipes are all connected with a water supply source, and a plurality of nozzles are arranged at the bottoms of the water distribution pipes.

The invention has the beneficial effects that:

(1) the invention adopts the cooling pipeline to carry out water cooling treatment on the waste water entering the biochemical treatment tank, and achieves the effect of quickly cooling the waste water by fully contacting the waste water with the baffling cooling plate.

(2) According to the invention, wastewater flows into the anaerobic tank from the through hole of the positioning shaft, and the rotating sleeve and the rotating plate are driven to rotate by the driving motor, so that the wastewater gradually flows to the outer layer under the centrifugal action, and the wastewater has a complex flow state, thereby improving the volume utilization rate and obtaining stronger treatment capacity; has good interception capability of biosolids and enables microorganisms in one reactor to grow in different areas; by the structural improvement, the flow path of water flow in the reactor is prolonged, thereby promoting the contact of wastewater and sewage.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a sectional view of a cooling circuit according to the present invention.

Fig. 3 is a sectional view of a cooling jacket according to the present invention.

FIG. 4 is a perspective view of a cooling baffle of the present invention.

FIG. 5 is a schematic view of the water cooling passages in the cooling baffle of the present invention.

FIG. 6 is a schematic view of the structure of the baffle apparatus of the present invention.

Fig. 7 is a top view of the hydrolysis acidification tank of the present invention.

Description of the reference numerals

Cooling pipeline 1,cooling jacket 11,sealing baffle 111,water inlet pipe 112,water outlet pipe 113, connectingpipe 114, circulatingpipeline 12,water tank 13, circulatingpump 14,baffling cooling plate 15,water pipe joint 151,housing 152,water flow channel 1521,cover 153,fixing rod 16, comprehensive adjusting tank 2,first aeration device 21,aeration loop 211,aeration branch pipe 212,aeration head 213,blower 214,stirring device 22,first fixing frame 221, stirringmotor 222,stirring shaft 223, stirringblade 224,first conveying pipe 3,first lift pump 31, anaerobic tank 4,baffling device 41,second fixing frame 411,driving motor 412,positioning shaft 413, throughhole 4131,baffling ring plate 414, rotatingsleeve 415,rotating plate 416,ventilation hole 4161, rotatingdisk 417, spiral convexstrip 4171,second conveying pipe 5,second lift pump 51,hydrolysis acidification tank 6,baffling plate 61, third conveying pipe 7,water tank 13,water circulation pump 14,water pipe 15,water pipe joint 151,housing 152,water flow channel 1521,cover 153,fixing rod 16, stirring blade 4, anaerobic tank 4,baffle 41,second lifting pump 51, water flow channel,water channel 4161, third conveying pipe 7, water channel, and water channel, and water channel 2, and water channel, A third lift pump 71, acontact oxidation pond 8, asecond aeration device 81, amicroorganism packing layer 82, awater distribution device 83, awater distribution pipe 831, aspray head 832, afourth conveying pipe 9, afourth lift pump 91, asecondary sedimentation tank 10, a three-way pipe 101, asludge conveying pump 102, asludge return pump 103 and areturn pipe 104.

Detailed Description

In order to make the technical scheme of the invention clearer and clearer, the invention is further described with reference to the accompanying drawings, and any scheme obtained by carrying out equivalent replacement and conventional reasoning on the technical characteristics of the technical scheme of the invention falls into the protection scope of the invention. The fixing and the arrangement of the fixing and the connection are all general connection modes in the mechanical field, and the fixing and the connection can be performed by welding, bolt and nut connection and screw connection.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

As shown in fig. 1-7, a biochemical treatment system for extracting N-methyl pyrrolidone from wastewater is characterized in that the biochemical treatment system comprises acooling pipeline 1, an integrated adjusting tank 2, an anaerobic tank 4, ahydrolysis acidification tank 6, acontact oxidation tank 8 and asecondary sedimentation tank 10, wherein thecooling pipeline 1 conveys the wastewater into the integrated adjusting tank 2, afirst aeration device 21 and astirring device 22 are arranged in the integrated adjusting tank 2, and the collected wastewater is stirred and homogenized, the wastewater is injected into the anaerobic tank 4 from one side of the integrated adjusting tank 2 through afirst conveying pipe 3 and afirst lifting pump 31, abaffle device 41 for changing the flow state of the water flow is arranged in the anaerobic tank 4, and the water flow passes through the baffle device to obtain a complex hydraulic flow state, so that the volume utilization rate of the reaction tank is high, and the strong treatment capacity can be obtained; the biological solid interception device has good biological solid interception capability, and microorganisms in a reaction tank grow in different areas and contact with inlet water at different stages, so that the separation of biological phases is realized to a certain extent, and the treatment effect of a facility can be stabilized and improved; through the improvement of the structure, the flow path of water flow in the reactor is prolonged, thereby promoting the contact of the wastewater and the sewage, and the anaerobic tank 4 injects the wastewater into thehydrolytic acidification tank 6 through a second conveyingpipe 5 matched with asecond lift pump 51;

the bottom of thehydrolysis acidification tank 6 is provided with a plurality ofbaffle plates 61 which are arranged in a staggered manner, wherein the hydrolysis acidification mainly converts non-soluble organic matters in the original wastewater into soluble organic matters, and mainly converts organic matters which are difficult to biodegrade into organic matters which are easy to biodegrade, so that the biodegradability of the wastewater is improved, the pH value of the sewage is reduced, and the sludge yield is reduced, thereby being beneficial to subsequent aerobic treatment. The hydrolysis acidification tank is arranged, so that the removal effect of the whole system on organic matters and suspended matters can be improved, the organic load of the aerobic system is reduced, and compared with the case of singly using the aerobic system, the energy consumption of the whole system is greatly reduced, and the wastewater is conveyed to thecontact oxidation tank 8 through the third conveying pipe 7 and the third lifting pump 71 in thehydrolysis acidification tank 6;

thecontact oxidation pond 8 is internally provided with asecond aeration device 81, amicroorganism packing layer 82 and a water distribution device 8383 from bottom to top, thecontact oxidation pond 8 is matched with afourth lift pump 91 through afourth delivery pipe 9 to deliver wastewater to asecondary sedimentation pond 10, thesecondary sedimentation pond 10 is a vertical sedimentation pond, the bottom of thesecondary sedimentation pond 10 is respectively connected with asludge delivery pump 102 and asludge return pump 103 through a three-way pipe 101, the outlet end of thesludge return pump 103 is connected with areturn pipe 104, thereturn pipe 104 is connected with thehydrolysis acidification pond 6, so that thesludge return pump 103 returns precipitated sludge to thehydrolysis acidification pond 6, thesludge delivery pump 102 delivers sludge to the sludge pond through a pipeline, wherein the sludge return ratio is 50-100%, and the rest sludge is discharged to the sludge pond as residual sludge.

Further, thecooling pipeline 1 comprises acooling sleeve 11 and a plurality of bafflingcooling plates 15 arranged in thecooling sleeve 11, one end of thecooling sleeve 11 is connected with the comprehensive regulating tank 2 through a pipeline, the side wall of thecooling sleeve 11 is of a hollow structure, two ends of the inner cavity of thecooling sleeve 11 are provided with sealingbaffles 111, the twosealing baffles 111 separate the inner cavity of thecooling sleeve 11 into two independent cavities, one side of each of the two cavities is provided with awater inlet pipe 112 and awater outlet pipe 113 which are respectively connected with thewater inlet pipe 112 and thewater outlet pipe 113, thewater inlet pipe 112 and thewater outlet pipe 113 are connected with a circulatingpipeline 12, the circulatingpipeline 12 is connected with awater tank 13, the circulatingpump 14 is arranged on the circulatingpipeline 12, and two sides of the inner wall of thecooling sleeve 11 are symmetrically provided with a plurality of connectingpipes 114; it is a plurality of bafflingcooling plate 15 is vertical setting and transverse arrangement sets up the inboard atcooling jacket 11, and a plurality of bafflingcooling plate 15 are improved level and are run through and be equipped with a plurality ofdead levers 16, the both ends ofdead lever 16 andcooling jacket 11's both ends inner wall fixed connection, all be equipped withrivers passageway 1521 in bafflingcooling plate 15's the inner chamber, and bafflingcooling plate 15's both sides are equipped with a plurality ofwater pipe head 151,water pipe head 151 withrivers passageway 1521 communicates, and the position ofwater pipe head 151 is corresponding with the connectingpipe 114 position ofcooling jacket 11 inner wall both sides, and fixed connection between a plurality ofwater pipe head 151 and a plurality of connectingpipe 114 for water in cooling jacket's wherein cavity flows to another cavity through the rivers passageway among the baffling cooling plate.

Further, bafflingcooling plate 15 includescasing 152 andlid 153,lid 153 andcasing 152 all are bow-shaped structure, andlid 153 passes through bolt and nut to be fixed in one side ofcasing 152 and seal thecasing 152 inner chamber, and it is a plurality of that top-down sets up in thecasing 152rivers passageway 1521, and everyrivers passageway 1521 all is the setting of S type.

Further, thestirring device 22 includes afirst fixing frame 221 disposed above the integrated treatment tank, a stirringshaft 223 rotatably disposed at the center of thefirst fixing frame 221, and a stirringblade 224 disposed on the stirringshaft 223.

Further,baffle device 41 includessecond mount 411, drivingmotor 412, location axle 4131413,baffle plate 414 quantity is a plurality of and be the fixed setting in anaerobism pond 4 bottom of ring shape, and the diameter size of everybaffle plate 414 is crescent from inside to outside,second mount 411 is installed in anaerobism pond 4 top, fixed setting onsecond mount 411driving motor 412,second mount 411 center sets up perpendicularly location axle 4131413, and location axle 4131413 lower extreme is fixed in anaerobism pond 4 bottom and is located the center of a plurality ofbaffle plate 414, and location axle 4131413 is the hollow shaft, location axle 4131413 upper end withfirst conveyer pipe 3 is connected, and a plurality of openings have been seted up to location axle 4131413 lower extreme surface, rotates on the location axle 4131413 to be equipped withrotatory cover 415,rotatory cover 415 outer wall passes through the bearing and is connected withsecond mount 411 rotation, the outer wall of the rotatingsleeve 415 is in transmission connection with an output shaft of thedriving motor 412 through a transmission wheel matched with a transmission belt, the bottom of the rotatingsleeve 415 is horizontally provided with arotating plate 416 with a circular structure, the bottom of the rotatingplate 416 is provided with a plurality of rotatingdiscs 417 with a circular structure, the rotatingdiscs 417 are all in a hollow circular truncated cone structure, the diameter of each rotatingdisc 417 is gradually reduced and increased from inside to outside, and the rotatingdiscs 417 and thebaffle ring plates 414 are arranged in a staggered mode.

Further, therotating plate 416 is provided with a plurality ofventilation holes 4161.

Further, the inner wall of the rotatingdisc 417 is provided withspiral ribs 4171 distributed along the center of the rotatingdisc 417, so that when the rotating disc rotates, the spiral ribs can drive the water flow to obtain centrifugal force and the water flow flows to the outer layer. .

Further, each of thefirst aeration device 21 and thesecond aeration device 81 comprises anaeration loop 211, a plurality ofaeration heads 213 respectively disposed on theaeration loop 211, and ablower 214 communicated with theaeration loop 211.

Furthermore, anaeration branch pipe 212 is connected to anaeration ring pipe 211 of thesecond aeration device 81, and an aeration hole is opened on theaeration branch pipe 212 and is arranged in themicrobial filler layer 82.

Further, thewater distribution device 83 includes a plurality ofwater distribution pipes 831 transversely disposed above thecontact oxidation tank 8, thewater distribution pipes 831 are all connected with a water supply source, and a plurality ofnozzles 832 are arranged at the bottom of thewater distribution pipes 831.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are also included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (8)

1. A biochemical treatment system for extracting N-methylpyrrolidone from wastewater is characterized by comprising a cooling pipeline (1), a comprehensive adjusting tank (2), an anaerobic tank (4), a hydrolysis acidification tank (6), a contact oxidation tank (8) and a secondary sedimentation tank (10), wherein the cooling pipeline (1) conveys the wastewater into the comprehensive adjusting tank (2), a first aeration device (21) and a stirring device (22) are arranged in the comprehensive adjusting tank (2) and stir and homogenize the collected wastewater, one side of the comprehensive adjusting tank (2) injects the wastewater into the anaerobic tank (4) through a first conveying pipe (3) matched with a first lifting pump (31), a baffling device (41) for changing the flow state of the water flow is arranged in the anaerobic tank (4), and the anaerobic tank (4) injects the wastewater into the hydrolysis acidification tank (6) through a second conveying pipe (5) matched with a second lifting pump (51), a plurality of baffle plates (61) which are arranged in a staggered mode are arranged at the bottom of the hydrolysis acidification tank (6), and the hydrolysis acidification tank (6) is used for conveying the wastewater to the contact oxidation tank (8) through a third conveying pipe (7) and a third lifting pump (71); a second aeration device (81), a microorganism packing layer (82) and a water distribution device (83) are arranged in the contact oxidation tank (8) from bottom to top, the contact oxidation tank (8) is matched with a fourth lifting pump (91) through a fourth conveying pipe (9) to convey wastewater to a secondary sedimentation tank (10), the secondary sedimentation tank (10) is a vertical sedimentation tank, the bottom of the secondary sedimentation tank (10) is respectively connected with a sludge conveying pump (102) and a sludge return pump (103) through a three-way pipe (101), the outlet end of the sludge return pump (103) is connected with a return pipe (104), the return pipe (104) is connected with the hydrolysis acidification tank (6), so that the sludge return pump (103) returns precipitated sludge to the hydrolysis acidification tank (6), and the sludge conveying pump (102) conveys sludge to the sludge tank through a pipeline;

the cooling pipeline (1) comprises a cooling sleeve (11) and a plurality of baffling cooling plates (15) arranged in the cooling sleeve (11), one end of the cooling sleeve (11) is connected with the comprehensive adjusting tank (2) through a pipeline, the side wall of the cooling sleeve (11) is of a hollow structure, and the two ends of the inner cavity of the cooling sleeve (11) are provided with sealing baffles (111), the two sealing baffles (111) separate the inner cavity of the cooling sleeve (11) into two independent cavities, one side of each cavity is respectively provided with a water inlet pipe (112) and a water outlet pipe (113) which are respectively connected with the water inlet pipe (112) and the water outlet pipe (113), the water inlet pipe (112) and the water outlet pipe (113) are connected with a circulating pipeline (12), the circulating pipeline (12) is connected with a water tank (13), a circulating pump (14) is arranged on the circulating pipeline (12), and a plurality of connecting pipes (114) are symmetrically arranged on two sides of the inner wall of the cooling sleeve (11); the multiple baffling cooling plates (15) are longitudinally arranged and transversely arranged on the inner side of the cooling sleeve (11), multiple fixing rods (16) horizontally penetrate through the multiple baffling cooling plates (15), two ends of each fixing rod (16) are fixedly connected with the inner walls of two ends of the cooling sleeve (11), water flow channels (1521) are arranged in inner cavities of the baffling cooling plates (15), multiple water pipe joints (151) are arranged on two sides of each baffling cooling plate (15), the water pipe joints (151) are communicated with the water flow channels (1521), the positions of the water pipe joints (151) correspond to the positions of the connecting pipes (114) on two sides of the inner wall of the cooling sleeve (11), and the multiple water pipe joints (151) are fixedly connected with the connecting pipes (114);

baffling cooling plate (15) are including casing (152) and lid (153), lid (153) and casing (152) all are bow-shaped structure, and lid (153) pass through bolt and nut to fix in one side of casing (152) and seal casing (152) inner chamber, and top-down sets up a plurality ofly in casing (152) rivers passageway (1521), and every rivers passageway (1521) all are the setting of S type.

2. The biochemical treatment system for extracting N-methylpyrrolidone from wastewater according to claim 1, wherein said stirring means (22) comprises a first fixing frame (221) disposed above the integrated treatment tank, a stirring shaft (223) rotatably disposed at the center of the first fixing frame (221), and a stirring blade (224) disposed on the stirring shaft (223).

3. The biochemical treatment system for extracting N-methylpyrrolidone from wastewater according to claim 1, wherein the baffle device (41) comprises a second fixing frame (411), a driving motor (412), a positioning shaft (413), and baffle plates (414), the baffle plates (414) are plural and are fixedly arranged at the bottom of the anaerobic tank (4) in a circular ring shape, the diameter of each baffle plate (414) is gradually increased from inside to outside, the second fixing frame (411) is arranged above the anaerobic tank (4), the driving motor (412) is fixedly arranged on the second fixing frame (411), the positioning shaft (413) is vertically arranged at the center of the second fixing frame (411), the lower end of the positioning shaft (413) is fixed at the bottom of the anaerobic tank (4) and is positioned at the center of the baffle plates (414), and the positioning shaft (413) is a hollow shaft, the upper end of a positioning shaft (413) is connected with the first conveying pipe (3), a plurality of through holes are formed in the surface of the lower end of the positioning shaft (413), a rotating sleeve (415) is arranged on the positioning shaft (413) in a rotating mode, the outer wall of the rotating sleeve (415) is connected with a second fixing frame (411) in a rotating mode through a bearing, the outer wall of the rotating sleeve (415) is connected with an output shaft of a driving motor (412) in a transmission mode through a driving wheel in a matching mode, a rotating plate (416) of a circular structure is horizontally arranged at the bottom of the rotating sleeve (415), a plurality of rotating discs (417) of the circular structure are arranged at the bottom of the rotating plate (416), the rotating discs (417) are all of hollow circular truncated cone structures, the diameter size of each rotating disc (417) is gradually reduced and increased from inside to outside, and each rotating disc (417) and a baffle plate (414) are arranged in a staggered mode.

4. The biochemical treatment system for extracting N-methylpyrrolidone from wastewater as claimed in claim 3, wherein said rotating plate (416) is opened with a plurality of ventilation holes (4161).

5. A biochemical treatment system for extracting N-methylpyrrolidone from wastewater according to claim 3, wherein the inner wall of the rotary disk (417) is provided with spiral ribs (4171) distributed along the center of the rotary disk (417).

6. A biochemical treatment system for extracting N-methylpyrrolidone from wastewater according to claim 1, wherein each of said first aeration device (21) and said second aeration device (81) comprises an aeration loop (211), a plurality of aeration heads (213) respectively disposed on said aeration loop (211), and a blower (214) in communication with said aeration loop (211).

7. The biochemical treatment system for extracting N-methylpyrrolidone from wastewater, according to claim 6, wherein a branch aerator pipe (212) is connected to the aeration loop (211) of the second aerator (81), and the branch aerator pipe (212) is provided with aeration holes and disposed in the microorganism packing layer (82).

8. The biochemical treatment system for extracting N-methylpyrrolidone from wastewater according to claim 1, wherein said water distribution device (83) comprises a plurality of water distribution pipes (831) transversely disposed above the contact oxidation tank (8), said water distribution pipes (831) are connected to a water supply source, and a plurality of nozzles (832) are arranged at the bottom of the water distribution pipes (831).

Images