CN108947004B

CN108947004B - Sedimentation and air flotation composite tank

Info

Publication number: CN108947004B
Application number: CN201810752279.7A
Authority: CN
Inventors: 李海林
Original assignee: Shaoxing Nanyang Weaving Printing & Dyeing Co ltd
Current assignee: Shaoxing Nanyang Weaving Printing & Dyeing Co ltd
Priority date: 2018-07-10
Filing date: 2018-07-10
Publication date: 2021-04-13
Anticipated expiration: 2038-07-10
Also published as: CN108947004A

Abstract

The invention discloses a sedimentation and air floatation composite tank, which solves the problem that the occupied area of a sedimentation tank and an air floatation tank is large in the prior stage. The technical scheme is that the sedimentation and air floatation composite tank comprises a sedimentation tank, a guide groove which is arranged along the edge of the top of the sedimentation tank and is not communicated with the sedimentation tank, and an air floatation tank which is positioned on one side of the sedimentation tank and is communicated with the guide groove at the upper end, wherein the bottom surface of the guide groove is a guide inclined surface which is inclined downwards along the direction towards the air floatation tank; the sedimentation tank is also provided with a water inlet pipe for introducing sewage into the sedimentation tank and a sewage discharge pipe for discharging pollutants at the bottom of the sedimentation tank; the air supporting tank is also provided with a first aeration device for increasing the content of bubbles in sewage in the air supporting tank, a slag scraping machine for sweeping pollutants on the water surface of the air supporting tank into the sewage draining tank is arranged at the top of the air supporting tank, which is provided with the sewage draining tank on one side of the air supporting tank, the air supporting tank is also provided with a water outlet pipe, the floor area of the sedimentation air supporting composite tank is smaller, and the purification process of sedimentation and air supporting can be carried out on sewage.

Description

Sedimentation and air flotation composite tank

Technical Field

The invention belongs to the field of wastewater treatment, and particularly relates to a sedimentation and air flotation composite tank.

Background

When the sewage is treated in the printing and dyeing industry, the sewage needs to pass through an anaerobic tank, an aerobic tank, a sedimentation tank and an air floating tank in sequence and is finally discharged through a discharge tank. Because the auxiliary agent is required to be added into the sedimentation tank to precipitate part of pollutants, the sewage treated by the sedimentation tank is introduced into the air floatation tank, and the coagulant is added into the air floatation tank, so that the pollutants float on the water surface of the air floatation tank after being brought up by bubbles after part of pollutants are flocculent, and are finally scraped off by the slag scraping device of the air floatation tank.

The sedimentation tank and the air flotation tank at the present stage are both independently arranged and are communicated with each other through a conveying pipeline, and the arrangement mode leads to larger occupied area of the sedimentation tank and the air flotation tank, so that a sedimentation and air flotation composite tank capable of carrying out sedimentation and air flotation sewage treatment processes is required to be developed.

Disclosure of Invention

The invention aims to provide a sedimentation and air flotation composite tank which occupies a small area and can perform sedimentation and air flotation purification processes on sewage.

The technical purpose of the invention is realized by the following technical scheme:

a sedimentation and air floatation composite tank comprises a sedimentation tank, a guide tank which is arranged along the edge of the top of the sedimentation tank and is not communicated with the sedimentation tank, and an air floatation tank which is positioned on one side of the sedimentation tank and is communicated with the guide tank at the upper end, wherein the bottom surface of the guide tank is a guide inclined surface which is inclined downwards along the direction towards the air floatation tank; the sedimentation tank is also provided with a water inlet pipe for introducing sewage into the sedimentation tank and a sewage discharge pipe for discharging pollutants at the bottom of the sedimentation tank; the air supporting groove is also provided with a first aeration device for increasing the content of bubbles in the sewage in the air supporting groove, one side of the air supporting groove is provided with a sewage discharge groove, the top of the air supporting groove is provided with a slag scraping machine for sweeping the pollutants on the water surface of the air supporting groove into the sewage discharge groove, and the air supporting groove is also provided with a water outlet pipe.

By adopting the technical scheme, sewage firstly enters the precipitation tank through the water inlet pipe, partial impurities are precipitated by adding the auxiliary agent in the precipitation tank, precipitated pollutants are precipitated at the bottom of the precipitation tank and finally discharged out of the precipitation tank through the sewage discharge pipe, and the water level in the precipitation tank gradually rises along with the increase of the sewage amount in the precipitation tank until the sewage overflows from the precipitation tank; the sewage with the part of pollutants discharged out overflows from the top edge of the precipitation tank, enters the guide groove and enters the air flotation tank along the guide inclined plane; coagulant can be added in the air flotation tank, the impurity that floats in the sewage is condensed and is the flocculent floater, and the first aeration equipment of air flotation tank can fill a large amount of microbubbles in the sewage of air flotation tank, and the microbubble adsorbs on the flocculent floater, takes the flocculent floater to the surface of water in air supporting pond to scrape the blowdown inslot through scraping the sediment machine with the flocculent floater. Above-mentioned structure setting of deposiing air supporting composite tank, sewage can deposit in the precipitation tank to carry out the air supporting in the air supporting inslot, reduced the content of pollutant in the sewage.

By adopting the sedimentation and air-flotation composite tank with the structure, sewage is guided into the air-flotation tank in the modes of the guide groove and the guide inclined plane, so that the floor area of the sedimentation and air-flotation composite tank can be effectively reduced. Meanwhile, when sewage overflowing from the settling tank passes through the guide groove, the sewage forms a layer on the guide inclined plane, so that the oxygen content in the sewage can be effectively improved, the air floatation process of the sewage in the air floatation tank is facilitated, and the effect of purifying the sewage in the air floatation tank is facilitated to be improved.

As a further improvement of the invention, a second aeration device is further arranged in the guide groove, and the second aeration device comprises a plurality of second aeration heads arranged on the guide inclined plane, a second aeration pump for supplying air to the second aeration heads, and a second aeration pipe for communicating the second aeration pump and the second aeration heads.

Through adopting above-mentioned technical scheme, the second aeration equipment can oxygenate in the sewage in the guide way, and the second aeration head can fill into a large amount of small bubbles in the sewage for the suspended solid pollutant of part floats in the sewage in the guide way, realizes the effect of air supporting in advance. The content of suspended pollutants in the sewage subjected to pre-air floatation is reduced, and the effect of purifying the sewage in the air floatation tank is improved, so that the water purification effect of the whole sedimentation air floatation composite tank is improved.

As a further improvement of the invention, the guide inclined plane is uniformly provided with an aeration base, the aeration base is provided with an aeration slot for a second aeration head to insert, the side wall of the aeration base is uniformly provided with outer aeration holes communicated with the aeration slot, the bottom of the aeration slot is provided with a base magnetic disc, and the end part of the second aeration head is provided with a fixed magnetic disc capable of being adsorbed with the base magnetic disc.

Through adopting above-mentioned technical scheme, the cooperation of the base magnetic disc of aeration base and the fixed magnetic disc of second aeration head can make things convenient for the installation and the dismantlement of second aeration head.

In a further improvement of the present invention, the second aeration pipe includes a support pipe and an aeration hose communicating the support pipe and the second aeration head, the bottom of the support pipe has a hose connector for mounting the aeration hose, and the support pipe is further provided with a connector end cap for sealing and covering the hose connector.

Through adopting above-mentioned technical scheme, the second aeration pipe includes support pipeline and aeration hose, and hose nipple's setting can make things convenient for the installation of aeration hose and support pipeline to the quantity of the second aeration head in the whole guide way of convenient adjustment, thereby the air supporting degree in advance in the regulation guide way.

As a further improvement of the invention, a filter screen assembly is further arranged at one end of the guide groove close to the air flotation groove, the filter screen assembly comprises a first filter screen for cutting off the guide groove and a second filter screen which is arranged at one side of the first filter screen close to the air flotation tank and is L-shaped, a sewage discharge channel is formed between the first filter screen and the second filter screen, the sedimentation air flotation composite tank is further provided with a sewage discharge pipeline for communicating the sewage discharge channel with the sewage discharge groove, and the horizontal height of the top edge of the first filter screen is lower than that of the top edge of the guide groove.

Through adopting above-mentioned technical scheme, the structure setting of filter screen subassembly can conveniently filter the impurity of air supporting in advance in the guide way. When the first filter screen is blocked, the water level of the sewage in the guide groove is increased until the sewage overflows the first filter screen; sewage passes through the upper edge of the first filter screen and enters the sewage discharge channel, sewage is discharged from the filter holes of the second filter screen, flocculent pollutants are left in the sewage discharge channel and finally enter the sewage discharge groove from the sewage discharge pipeline. The setting of this kind of structure can carry out prefilter to the sewage of guide way to the air supporting groove, has reduced the quantity that enters into the showy pollutant in the air supporting groove, and above-mentioned filter screen subassembly still has preliminary anti-clogging ability.

As a further improvement of the invention, the side wall of the guide groove is provided with a sewage discharge through hole for installing a sewage discharge pipeline, the bottom of the sewage discharge channel is a sewage discharge inclined plane which is inclined downwards towards the direction of the sewage discharge through hole, and the horizontal height of the lower edge of the sewage discharge through hole is higher than the horizontal height of the lowest part of the sewage discharge inclined plane.

Through adopting above-mentioned technical scheme, the setting of above-mentioned structure helps arranging the pollutant in the blowdown passageway to the blowdown through-hole to arrange to the blowdown inslot through sewage pipes.

As a further improvement of the invention, a guide lip arranged along the width direction of the guide groove is arranged at the connecting part of the guide groove and the air flotation groove, the upper edge of the guide lip is fixed on the bottom surface of the guide groove, and a gap exists between the lower edge of the guide lip and the inner wall of the air flotation groove.

Through adopting above-mentioned technical scheme, the setting of direction lip can conveniently be with the leading-in air supporting inslot of sewage of guide way, and sewage can be along the direction lip and follow the lower border of direction lip and break away from the back, forms the water curtain and falls into in the air supporting inslot.

As a further improvement of the invention, the slag scraper comprises a chain plate assembly, a chain wheel for supporting the chain plate assembly and a driving motor for driving the chain wheel to rotate, wherein the chain plate assembly comprises two conveying chains matched with the chain wheel, a plurality of chain plates arranged between the two conveying chains and a scraper arranged on one side of the chain plate far away from the chain wheel.

Through adopting above-mentioned technical scheme, scrape the simple structure of sediment machine, carry stably, and can carry out the impurity of scraping out on the air supporting pond water face that lasts for a long time.

As a further improvement of the invention, the chain plate is uniformly provided with water permeable holes.

Through adopting above-mentioned technical scheme, the sewage that can conveniently lead the guide way down in the setting in hole of permeating water sees through the link joint, has also prevented piling up of sewage on the link joint.

In conclusion, the invention has the following beneficial effects:

1. a sedimentation and air flotation composite tank is provided with a sedimentation tank, a guide groove and an air flotation tank, and water overflowing from the sedimentation tank is finally guided into the air flotation tank through the guide groove, so that the purification processes of sedimentation and air flotation are realized;

2. the guide way is equipped with second aeration equipment, has further promoted the sewage to the guide way in and has carried out the aeration for floating the pollutant in the sewage carries out air supporting in advance, and filters this part floating pollutant through setting up the filter screen subassembly, reduces the quantity that enters into the pollutant in the air supporting pond.

Drawings

FIG. 1 is a schematic structural diagram of a precipitation and air-flotation composite tank according to the present invention;

FIG. 2 is a schematic sectional view of a precipitation tank according to the present invention;

FIG. 3 is an enlarged view taken at A in FIG. 2;

FIG. 4 is a schematic view of the combination of the support tube, the aeration hose, the second aeration head, the aeration base, and the connector end cap in an explosive state according to the present invention;

FIG. 5 is a schematic structural view of a sedimentation-floatation combined tank at another angle in the present invention;

FIG. 6 is an enlarged view at B in FIG. 5;

FIG. 7 is an enlarged view at C of FIG. 5;

FIG. 8 is a schematic view of a screen assembly according to the present invention;

FIG. 9 is a schematic structural diagram of the floatation tank in the invention when no chain plate is installed;

fig. 10 is a schematic structural view of the slag scraper of the present invention.

In the figure: 100. a settling tank; 110. a water dripping port; 200. a guide groove; 210. a guide slope; 220. an aeration base; 221. aeration slots; 222. an outer aeration hole; 223. a base disk; 230. a screen assembly; 231. a first filter screen; 232. A second filter screen; 233. a trapway; 234. a sewage discharge through hole; 235. a blowdown line; 240. a guide lip; 300. an air flotation tank; 310. a water outlet pipe; 400. a water inlet pipe; 410. mounting a bracket; 411. a fixing ring; 412. a support bar; 500. a blow-off pipe; 510. a first blowdown section; 520. a second blowdown section; 530. a sewage pump; 600. a second aeration device; 610. a second aeration head; 611. fixing the magnetic disk; 612. an aeration hole; 620. a second aeration pump; 630. a support conduit; 631. a hose connector; 640. an aeration hose; 650. a connector end cap; 700. a first aeration device; 710. a first aeration conduit; 720. a first aeration head; 730. a first aeration pump; 800. a sewage draining groove; 810. a sewage draining outlet; 900. a slag scraper; 911. A conveyor chain; 912. a chain plate; 913. a squeegee; 914. water permeable holes; 920. a sprocket; 930. the motor is driven.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Referring to fig. 1, a sedimentation and air flotation composite tank mainly comprises a sedimentation tank 100, a guide tank 200 and an air flotation tank 300. Wherein, the guide groove 200 is arranged at the outer side of the precipitation tank 100, and the bottom surface of the guide groove 200 is lower than the top edge of the precipitation tank 100, i.e. the sewage overflowing from the precipitation tank 100 falls into the guide groove 200; the air flotation tank 300 is disposed at one side of the settling tank 100, and one side of the air flotation tank 300 is communicated with the guide tank 200, i.e., the sewage in the guide tank 200 can be discharged into the air flotation tank 300.

Referring to fig. 1 and 2, the settling tank 100 is a circular tank, and the bottom surface of the settling tank 100 is a tapered surface downwardly inclined toward the center of the bottom. The settling tank 100 is further provided with a water inlet pipe 400 for introducing sewage into the settling tank 100, the water inlet pipe 400 extends into the settling tank 100, and the depth of the water inlet pipe 400 extends into two thirds of the depth of the settling tank 100.

Referring to fig. 2 and 3, a mounting bracket 410 for supporting the water inlet pipe 400 is further disposed in the settling tank 100, and the mounting bracket 410 includes a fixing ring 411 for fixing the water inlet pipe 400 and a support rod 412 for supporting and fixing the sleeve and the inner wall of the settling tank 100. In the present embodiment, the mounting bracket 410 has six support rods 412, and the six support rods 412 are uniformly arranged along the circumferential direction of the fixing ring 411.

The sedimentation and air-floatation composite tank is also provided with a sewage discharge pipe 500 for discharging the pollutants at the bottom of the sedimentation tank 100 out of the sedimentation tank 100. In this embodiment, the soil exhaust pipe 500 includes a first soil exhaust section 510 facing downward along the bottom of the precipitation tank 100 in a tapered shape and a second soil exhaust section 520 extending through the precipitation tank 100 and disposed horizontally. Wherein, the distance between the lower end of the first pollution discharging section 510 and the bottom of the settling tank 100 is not more than 20cm, and the second pollution discharging section 520 is provided with a pollution discharging pump 530. When the sewage pump 530 starts to operate, the contaminants at the bottom of the settling tank 100 enter the sewage pipe 500 from the first sewage section 510 of the sewage pipe 500 by the suction force of the sewage pump 530 and are finally discharged from the second sewage section 520.

Wherein, the top edge of the settling tank 100 is on the same horizontal plane, and the top edge of the settling tank 100 is uniformly provided with inverted regular triangle water dripping ports 110 in the circumferential direction.

Referring to fig. 1 and 4, the guide groove 200 is formed outside the settling tank 100, and the guide groove 200 has a rectangular shape as a whole. The bottom surface of the guide groove 200 is a guide slope 210 that is inclined downward toward the air bearing groove 300. Wherein, the guide inclined plane 210 is uniformly provided with aeration bases 220, the top of the aeration base 220 is provided with an aeration slot 221, the aeration slot 221 is vertically arranged, and the side wall of the aeration base 220 is uniformly provided with outer aeration holes 222 communicated with the aeration slot 221. The bottom of the aeration slot 221 is a horizontal plane, the aeration base 220 is provided with a base disk 223 at the bottom of the aeration slot 221, and the base disk 223 is directly fixed at the bottom of the aeration base 220 by waterproof glue.

The sedimentation-air-flotation composite tank is further provided with a second aeration device in the guide groove 200, and the second aeration device comprises a plurality of second aeration heads 610 arranged on the guide inclined plane 210, a second aeration pump 620 for supplying air to the second aeration heads 610, and a second aeration pipe for communicating the second aeration pump 620 with the second aeration heads 610.

Wherein, the aeration pipe comprises a bracket pipe 630 and an aeration hose 640 communicating the bracket pipe 630 and the second aeration head 610, and the bottom of the bracket pipe 630 is provided with a hose connector 631 for mounting the aeration hose 640. In the present embodiment, the aeration hose 640 and the hose joint 631 are fixed by screw coupling. In order to adjust the number of aeration hoses 640, a connector cap 650 capable of sealing and covering the hose connector 631 is further disposed on the holder pipe 630, and the connector cap 650 and the hose connector 631 are also screwed together.

The second aeration head 610 is installed at an end of the aeration hose 640 away from the bracket pipe 630, and the second aeration head 610 can be inserted into the aeration insertion slot 221 of the aeration base 220. The end of the second aeration head 610 has a fixed disk 611 that can be attracted to the base disk 223. In this embodiment, the sidewall of the second aeration head 610 is provided with aeration holes 612.

The second aeration apparatus can introduce air into the support pipe 630 for the second aeration through the second aeration pump 620, and the air of the support pipe 630 is discharged into the sewage of the guide groove 200 sequentially through the aeration hose 640 and the second aeration head 610, so that the oxygen content in the sewage can be increased, and a part of the fixed floating objects float upward.

Referring to fig. 5 and 8, a filter screen assembly 230 is further disposed at an end of the guide groove 200 close to the air flotation groove 300, and the filter screen assembly 230 includes a first filter screen 231 blocking the guide groove 200 and an L-shaped second filter screen 232 installed at one side of the first filter screen 231 close to the air flotation tank. First filter screen 231 is connected with the bottom of guide way 200, and both ends respectively with the interior wall connection of guide way 200 both sides, just can enter into the air supporting pond behind the sewage of guide way 200 must pass through first filter screen 231 promptly.

Referring to fig. 1, 5 and 6, a trapway 233 is formed between a first screen 231 and a second screen 232, and both ends of the trapway 233 are covered by both inner walls of the guide groove 200. A drain through hole 234 and a drain 235 installed at the drain through hole 234 and discharging the precipitated contaminants out of the drain 233 are formed at one end of the inner wall of one side of the guide groove 200 of the drain 233. Wherein, the bottom of the sewage passage 233 is a sewage draining slope inclined downward toward the direction of the sewage draining through hole 234, and the horizontal height of the lower edge of the sewage draining through hole 234 is higher than the horizontal height of the lowest position of the sewage draining slope.

Referring to fig. 5 and 7, the guide groove 200 is provided with a guide lip 240 disposed along the width direction of the guide groove 200 at a connection portion communicating with the air bearing groove 300, an upper edge of the guide lip 240 is fixed to the bottom surface of the guide groove 200, and a gap is formed between a lower edge of the guide lip 240 and the inner wall of the air bearing groove 300. The guide lip 240 is provided to facilitate introduction of the sewage in the guide groove 200 into the air bearing groove 300.

Referring to fig. 9, the air flotation tank 300 is disposed at the opening of the guide tank 200, and the air flotation tank 300 is also a rectangular tank. The bottom of the air flotation tank 300 is provided with a first aeration device for increasing the bubble content of the sewage in the air flotation tank 300. The first aeration apparatus includes a first aeration pipe 710 disposed at the bottom of the air flotation tank 300, a first aeration head 720 disposed on the first aeration pipe 710, and a first aeration pump 730 disposed outside the air flotation tank 300 and communicating with the first aeration pipe 710.

Referring to fig. 1 and 9, the air flotation groove 300 is provided at one side in the length direction thereof with a drain groove 800, the width of the drain groove 800 is the same as that of the air flotation groove 300, and one side of the air flotation groove 300 is provided with a drain outlet 810. The top of the air-bearing tank 300 is also provided with a slag scraper 900 for sweeping the pollutants on the water surface of the air-bearing tank 300 into the sewage discharge tank 800 through a sewage discharge outlet 810. Wherein the drain pipe 235 is connected to the drain tank 800, and the contaminants in the drain channel 233 (see fig. 6) of the screen assembly 230 are finally introduced into the drain tank 800 through the drain pipe 235.

Referring to fig. 1 and 10, the scraper 900 comprises a chain plate assembly, a sprocket 920 for supporting the chain plate assembly and a driving motor 930 for driving the sprocket 920 to rotate, and the chain plate 912 assembly comprises two conveying chains 911 matched with the sprocket 920, a plurality of chain plates 912 arranged between the two conveying chains 911 and scrapers 913 arranged on the side of the chain plates 912 far away from the sprocket 920. Wherein, the link plate 912 is evenly provided with water permeable holes 914, which is convenient for sewage to pass through the link plate 912 and enter the air-bearing tank 300. The scraper 913 located at the lower end of the slag scraper 900 can be partially inserted into the sewage in the air flotation tank 300 and sweeps the floating contaminants on the water surface of the air flotation tank 300 into the sewage discharge tank 800 by the driving motor 930.

The lower end of the side wall of the air flotation tank 300 is further provided with a water outlet pipe 310, and the height of the water outlet pipe 310 is higher than that of the first aeration device.

The steps of the sewage purification of the sedimentation-floatation coincidence tank are as follows:

1. the sewage raw water enters the sedimentation tank 100 through the water inlet pipe 400, and large-particle pollutants are precipitated and accumulated at the bottom of the sedimentation tank 100;

2. the sewage at the upper end of the precipitation tank 100 overflows from the top edge of the precipitation tank 100 and enters the guide groove 200;

3. under the action of the second aeration device, part of floating pollutants in the sewage float upwards, are filtered by the filter screen assembly 230 and enter the air flotation tank 300;

4. the coagulant is added into the air flotation tank 300, so that the floating pollutants are flocculent, and under the action of the first aeration device, the flocculent pollutants float upwards and are finally scraped into the sewage discharge tank 800 under the action of the slag scraper 900, and the pollutants in the sewage flowing out of the water outlet pipe 310 are greatly reduced.

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present invention.

Claims

1. A sedimentation and air flotation composite tank is characterized by comprising a sedimentation tank (100), a guide groove (200) which is arranged along the top edge of the sedimentation tank (100) and is not communicated with the sedimentation tank (100), and an air flotation tank (300) which is positioned on one side of the sedimentation tank (100) and is communicated with the guide groove (200) at the upper end, wherein the bottom surface of the guide groove (200) is a guide inclined surface (210) which is inclined downwards along the direction towards the air flotation tank (300); the sedimentation tank (100) is also provided with a water inlet pipe (400) for introducing sewage into the sedimentation tank (100) and a sewage discharge pipe (500) for discharging pollutants at the bottom of the sedimentation tank (100); the air supporting tank (300) is further provided with a first aeration device for increasing the content of bubbles in the sewage in the air supporting tank (300), a sewage discharge tank (800) is arranged on one side of the air supporting tank (300), a slag scraper (900) for sweeping pollutants on the water surface of the air supporting tank (300) into the sewage discharge tank (800) is arranged at the top of the air supporting tank (300), and the air supporting tank (300) is further provided with a water outlet pipe (310).

2. The composite tank of claim 1, wherein the guide tank (200) is further provided with a second aeration device, and the second aeration device comprises a plurality of second aeration heads (610) installed on the guide slope (210), a second aeration pump (620) for supplying air to the second aeration heads (610), and a second aeration pipe for communicating the second aeration pump (620) and the second aeration heads (610).

3. The sedimentation-air-flotation composite tank as claimed in claim 2, wherein the guide slopes (210) are uniformly provided with aeration bases (220), the aeration bases (220) are provided with aeration slots (221) into which the second aeration heads (610) are inserted, the side walls of the aeration bases (220) are uniformly provided with outer aeration holes (222) communicated with the aeration slots (221), the bottoms of the aeration slots (221) are provided with base disks (223), and the ends of the second aeration heads (610) are provided with fixed disks (611) capable of being adsorbed with the base disks (223).

4. The composite tank of claim 3, wherein the second aeration pipe comprises a bracket pipe (630) and an aeration hose (640) communicating the bracket pipe (630) with the second aeration head (610), the bottom of the bracket pipe (630) is provided with a hose connector (631) for installing the aeration hose (640), and the bracket pipe (630) is further provided with a connector end cover (650) for sealing and covering the hose connector (631).

5. The sedimentation and air-flotation composite tank as claimed in claim 2, wherein the guide groove (200) is further provided with a filter screen assembly (230) at one end close to the air-flotation groove (300), the filter screen assembly (230) comprises a first filter screen (231) for isolating the guide groove (200) and an L-shaped second filter screen (232) arranged on one side of the first filter screen (231) close to the air-flotation tank, a sewage channel (233) is formed between the first filter screen (231) and the second filter screen (232), the sedimentation and air-flotation composite tank is further provided with a sewage pipeline (235) for communicating the sewage channel (233) with the sewage channel (800), and the horizontal height of the top edge of the first filter screen (231) is lower than that of the top edge of the guide groove (200).

6. The sedimentation and air-flotation composite tank as claimed in claim 5, wherein the side wall of the guide groove (200) is provided with a sewage through hole (234) for installing a sewage pipeline (235), the bottom of the sewage channel (233) is a sewage inclined plane which is inclined downwards towards the sewage through hole (234), and the horizontal height of the lower edge of the sewage through hole (234) is higher than the horizontal height of the lowest part of the sewage inclined plane.

7. The sedimentation and air-flotation composite tank as claimed in claim 1, wherein a guide lip (240) arranged along the width direction of the guide tank (200) is arranged at the connection part of the guide tank (200) and the air-flotation tank (300), the upper edge of the guide lip (240) is fixed on the bottom surface of the guide tank (200), and a gap exists between the lower edge of the guide lip (240) and the inner wall of the air-flotation tank (300).

8. The composite precipitating-air flotation tank according to claim 1, wherein the residue scraper (900) comprises a chain plate assembly, a chain wheel (920) for supporting the chain plate assembly and a driving motor (930) for driving the chain wheel (920) to rotate, the chain plate assembly comprises two conveying chains (911) matched with the chain wheel (920), a plurality of chain plates (912) arranged between the two conveying chains (911) and scrapers (913) arranged on the side of the chain plates (912) far away from the chain wheel (920).

9. The sedimentation and air-flotation composite tank as claimed in claim 8, wherein the link plates (912) are uniformly provided with water permeable holes (914).