CN104671614B - A kind of phosphorous treatment method of printing and dying wastewater and device - Google Patents

Abstract

The present invention relates to a kind of phosphorous treatment method of printing and dying wastewater and device, comprise wastewater equalization pond, decolouring dephosphorization pond, anoxic anaerobic reation pool, biochemical contact tank, second pond; Decolouring dephosphorization pond comprises mix and blend district and settling region, and anoxic anaerobic reation pool comprises the double oxygen section, anoxic section and the anaerobism section that are separated into by traverse baffle; Biochemical contact tank is provided with water inlet pipe, water distribution pyrometric cone, filler and aeration regulator control system; Waste water through equalizing tank regulating pondage and water quality, then enter decolouring dephosphorization pond, then enter anoxic anaerobic reation pool, biochemical contact tank carries out anoxic, anaerobic and aerobic reaction, qualified discharge after precipitation.

Description

A method and device for treating phosphorus-containing printing and dyeing wastewater

technical field

The invention relates to the technical field of wastewater treatment, in particular to a method and device for treating phosphorus-containing printing and dyeing wastewater.

Background technique

The printing and dyeing industry is a large discharge of industrial wastewater. The printing and dyeing wastewater has the characteristics of high chroma, high salt content, complex components, poor biodegradability, and difficult decolorization. It is difficult to use conventional methods to treat it. At the same time, surfactants are used in the dyeing and finishing process As a result, the concentration of phosphorus in printing and dyeing wastewater is high, and phosphorus-containing printing and dyeing wastewater has become a difficult problem for industrial wastewater treatment.

In the traditional printing and dyeing wastewater treatment process, the indicators of chroma, BOD ₅ , COD, SS, N-NH ₃ , and TN can all meet the national indicators, but the total phosphorus often fails to meet the discharge standards. Processing technology has important practical significance.

Contents of the invention

The technical problem to be solved by the present invention is: in order to solve the above problems in the treatment of phosphorus-containing printing and dyeing wastewater, the present invention provides a method and device for treating phosphorus-containing printing and dyeing wastewater.

The technical solution adopted by the present invention to solve the technical problem is: a method and device for treating phosphorus-containing printing and dyeing wastewater, including a wastewater adjustment tank, a decolorization and phosphorus removal tank, an anoxic anaerobic reaction tank, a biochemical contact tank, and a secondary sedimentation tank; The wastewater regulating pool, the decolorization and phosphorus removal pool, the anoxic anaerobic reaction pool, the biochemical contact pool, and the secondary sedimentation pool are connected in sequence.

The wastewater regulating tank includes an inlet pipe of the wastewater regulating tank, a pH value measurement and control system and an outlet pipe for adjusting the pH value, water quality and water volume of phosphorus-containing printing and dyeing wastewater.

The decolorization and phosphorus removal pool includes a mixing and stirring area and a sedimentation area. The bottom of the mixing and stirring area is provided with a water inlet pipe for the decolorization and phosphorus removal pool. Stirring device; said settling area is provided with a baffle, and the inner wall of the baffle and the decolorization and dephosphorization tank forms a waste water flow path that enters the settling area as waste water, and a three-phase separator is provided at the outlet of the settling area, and the upper part of the outlet of the settling area There is an overflow weir, the bottom of the sedimentation area is designed as a conical structure, and a sediment discharge valve is set at the bottom of the sedimentation area.

The anoxic-anaerobic reaction pool includes a participatory section, anoxic section and anaerobic section separated by baffles, and the head end of the participatory section is provided with an anoxic-anaerobic reaction pool inlet pipe for feeding waste water , the end of the anoxic section is connected with the head of the anoxic section, and the end of the anoxic section is connected with the head of the anaerobic section. The impact generated when the water flow enters, thereby playing the role of buffering the water flow and uniform water distribution; the end of the anaerobic section is equipped with a three-phase separator and an overflow weir, and the overflow weir is connected to the outlet pipe; the facultative section, the anoxic section and the anaerobic section The bottom of the oxygen section is designed as a conical structure, and the conical structure is connected to the sludge discharge valve; the facultative section, anoxic section and anaerobic section of the anoxic anaerobic reaction tank are designed as a conical structure, and the top of the conical structure is All have independent methane exhaust gas collection pipes.

The middle and lower part of the biochemical contact tank is provided with a biochemical contact tank water inlet pipe, and the lower part of the biochemical contact tank water inlet pipe is provided with a water distribution triangular cone; the lower part of the water distribution triangular cone is provided with an aeration control system, and the aeration control system It includes an aeration pan, a blower, and a dissolved oxygen measurement and control device; further, the aeration pan is a microporous aeration pan with micropores uniformly arranged therein. The aeration pan is connected to a blower through an aeration pipe, and the blower is arranged outside the biochemical contact tank, and a dissolved oxygen measurement and control device is arranged on the upper part of the biochemical contact tank and under the wastewater surface, and the dissolved oxygen measurement and control device regulates the work of the blower according to the oxygen capacity; The upper part of the water inlet pipe of the biochemical contact tank is filled with fillers; the outlet of the biochemical contact tank is provided with an overflow weir.

The outlet pipe of the biochemical contact tank is connected to the secondary settling tank, and a sludge return system is provided at the bottom of the secondary settling tank, and a part of the sludge flows back into the biochemical contact tank.

The water after the sedimentation treatment in the secondary settling tank passes through the overflow weir and then discharges up to the standard.

The decolorizing and dephosphorizing agent is prepared by mixing diatomite, activated carbon, bentonite, iron salt, calcium sulfate, aluminum sulfate, and organic flocculant in a mass ratio of 50:20:50:45:40:30:5.

A method for wastewater treatment using the above-mentioned phosphorus-containing printing and dyeing wastewater treatment device has the following steps:

① Phosphorus-containing printing and dyeing wastewater enters the wastewater regulating tank through the inlet pipe of the wastewater regulating tank to adjust the pH value, water quality and water volume of the wastewater.

②The adjusted water enters the decolorization and phosphorus removal pool through the inlet pipe of the decolorization and phosphorus removal tank at the bottom of the mixing zone of the decolorization and phosphorus removal pool, and is mixed with the decolorization and phosphorus removal agent from the chemical liquid addition system, and is mixed with the stirring device set in the middle of the stirring zone. Stirring; the decolorization and phosphorus removal agent removes the color and a certain amount of phosphorus of the wastewater through coagulation, precipitation and adsorption, and then the wastewater enters the wastewater flow channel in the sedimentation area, and the three-phase separator in the sedimentation area realizes the separation of mud and water.

③The sludge sinks to the lower part of the sedimentation area of the decolorization and phosphorus removal tank under the action of gravity, and is discharged through the sediment discharge valve at the bottom. The waste water is connected to the inlet pipe of the anoxic anaerobic reaction tank through the overflow weir, the outlet pipe and the connecting pipe.

④Wastewater enters the lower part of the anoxic anaerobic reaction pool through the inlet pipe of the anoxic anaerobic reaction pool in the anoxic anaerobic section; The sludge bed in each reaction chamber of the oxygen section, the anoxic section and the anaerobic section, the sludge in the reaction tank moves with the up and down flow of wastewater and the rise of biogas, the blocking effect of the baffle plate and the sludge itself The settling effect of the sludge reduces the flow rate of the sludge, so a large amount of sludge is trapped in the reaction tank, and the microorganisms in the reaction tank fully contact with the organic matter in the wastewater. The facultative bacteria in the facultative stage, the heterotrophic bacteria in the anoxic stage and the anaerobic stage hydrolyze the organic matter in the wastewater into organic acids, decompose the macromolecular organic matter into small molecular organic matter, and convert the insoluble organic matter into soluble organic matter.

⑤ After the anaerobic reaction, the three-phase separator installed at the end of the anaerobic section realizes the separation of mud, water and methane gas, and the sludge sinks to the lower part of the anoxic anaerobic reaction tank under the action of gravity, and the excess The sludge is discharged through the sludge discharge valve at the bottom. The methane waste gas produced by the anoxic anaerobic reaction pool is collected and discharged through the gas header at the top of the reaction pool. The waste water is connected to the water inlet pipe of the biochemical contact tank through the overflow weir, the outlet pipe and the connecting pipe.

⑥Waste water enters the middle and lower part of the biochemical contact tank through the water inlet pipe of the biochemical contact tank, and the water is evenly distributed under the action of the water distribution triangle cone. The dissolved oxygen measurement and control device regulates the work of the blower according to the oxygen capacity to ensure that the dissolved oxygen in the biochemical contact pool water is greater than 2mg/L, and the treated wastewater flows out through the overflow weir and the outlet pipe.

⑦ The outlet pipe of the biochemical contact tank is connected to the water distribution pipe of the secondary settling tank, part of the sedimented sludge in the secondary settling tank flows back to the biochemical contact tank, and part of it is used as excess sludge.

⑧The water after the sedimentation treatment in the secondary settling tank passes through the overflow weir and then discharges up to the standard.

⑨Excess sludge produced in decolorization and phosphorus removal tank, anoxic anaerobic reaction tank, biochemical contact tank and secondary settling tank is dehydrated and transported abroad.

The beneficial effects of the present invention are: the present invention has simple structure, low manufacturing cost, relatively good depth effect on the treatment of phosphorus-containing printing and dyeing wastewater, and convenient management.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Fig. 1 is a schematic structural view of a decolorization and phosphorus removal tank according to an embodiment of the present invention.

In Figure 1: 1. Decolorization and phosphorus removal tank, 1-1. Mixing and stirring zone, 1-2. Sedimentation zone, 1-3. Water inlet pipe of decolorization and phosphorus removal tank, 1-4. Chemical solution adding system, 1-5. Stirring device, 1-6. baffle plate, 1-7. three-phase separator, 1-8. overflow weir, 1-9. sediment discharge valve.

Fig. 2 is a schematic structural view of an anaerobic anaerobic reaction tank according to an embodiment of the present invention.

In Fig. 2: 2. anoxic anaerobic reaction tank, 2-1. baffle plate, 2-2. concurrent oxygen section, 2-3. anoxic section, 2-4. anaerobic section, 2-5. deficient Inlet pipe of anoxic anaerobic reaction tank, 2-6. Three-phase separator of anoxic anaerobic reaction tank, 2-7. Overflow weir of anoxic anaerobic reaction tank, 2-8. Sludge discharge valve, 2-9. Upper Cover, 2-10. Air collecting pipe.

Fig. 3 is a schematic structural diagram of a biochemical contact pool according to an embodiment of the present invention.

In Figure 3: 3. Biochemical contact tank, 3-1. Biochemical contact tank inlet pipe, 3-2. Water distribution triangle cone, 3-3. Aeration control system, 3-4. Filling, 3-5. Overflow weir.

Fig. 4 is a process flow diagram of an embodiment of the present invention.

detailed description

The present invention is described in further detail now in conjunction with accompanying drawing. These drawings are all simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, so they only show the configurations related to the present invention.

As shown in Figures 1 to 4, a method and device for treating phosphorus-containing printing and dyeing wastewater according to the present invention includes a wastewater adjustment tank, a decolorization and phosphorus removal tank 1, an anoxic anaerobic reaction tank 2, a biochemical contact tank 3, and a secondary sedimentation tank; The wastewater regulating pool, the decolorization and phosphorus removal pool 1, the anoxic anaerobic reaction pool 2, the biochemical contact pool 3, and the secondary sedimentation pool are connected in sequence.

The wastewater regulating tank includes an inlet pipe of the wastewater regulating tank, a pH value measurement and control system and an outlet pipe for adjusting the pH value, water quality and water volume of phosphorus-containing printing and dyeing wastewater.

The decolorization and phosphorus removal pool 1 includes a mixing and stirring zone 1-1 and a precipitation zone 1-2. The bottom of the mixing and stirring zone is provided with a decolorization and phosphorus removal pool inlet pipe 1-3, and the upper part is provided with a drug for adding a decolorization and phosphorus removal agent. The liquid addition system 1-4 is provided with a stirring device 1-5 in the middle of the stirring zone; a baffle 1-6 is arranged in the said sedimentation zone, and the baffle and the inner wall of the decolorization and dephosphorization tank form the waste water that enters the sedimentation zone as waste water Flow channel, three-phase separator 1-7 is provided at the outlet of the sedimentation area, overflow weir 1-8 is arranged at the upper part of the outlet of the sedimentation area, the bottom of the sedimentation area is designed as a conical structure, and a sediment discharge valve 1 is arranged at the bottom of the sedimentation area -9.

The anoxic-anaerobic reaction tank 2 includes an anoxic section 2-2, an anoxic section 2-3 and anaerobic section 2-4 separated by a baffle plate 2-1, and the anoxic section 2-2 first An anoxic anaerobic reaction pool inlet pipe 2-5 for feeding waste water is provided at the end, the end of the anoxic section 2-2 is connected with the head end of the anoxic section 2-3, and the end of the anoxic section 2-3 is connected with the anaerobic section 2 -4 The head end is connected, and the lower part of the baffle on the water inlet side of the anoxic section 2-3 and the anaerobic section 2-4 is provided with a 45-degree corner to avoid the impact of the water flow when it enters, thereby playing a role The function of buffering water flow and uniform water distribution; the end of the anaerobic section 2-4 is provided with a three-phase separator 2-6 and an overflow weir 2-7, and the overflow weir 2-7 is connected to the outlet pipe; the anaerobic section 2-2, deficient The bottom of the oxygen section 2-3 and the anaerobic section 2-4 is designed as a conical structure, and the conical structure is connected to the sludge discharge valve 2-8; The upper cover 2-9 of the section is designed as a conical structure, and the top of the conical structure is provided with an independent methane waste gas collecting pipe 2-10.

The middle and lower part of the biochemical contact pool 3 is provided with a biochemical contact pool inlet pipe 3-1, and the lower part of the biochemical contact pool inlet pipe 3-1 is provided with a water distribution triangle cone 3-2; the water distribution triangle cone 3-2 The lower part is provided with an aeration control system 3-3, and the aeration control system 3-3 includes an aeration pan, a blower, and a dissolved oxygen measurement and control device; further, the aeration pan is a micropore with micropores evenly arranged type aeration disc. The aeration pan is connected to a blower through an aeration pipe, and the blower is arranged outside the biochemical contact tank, and a dissolved oxygen measurement and control device is arranged on the upper part of the biochemical contact tank and under the wastewater surface, and the dissolved oxygen measurement and control device regulates the work of the blower according to the oxygen capacity; A filler 3-4 is built in the upper part of the water inlet pipe; an overflow weir 3-5 is arranged at the outlet of the biochemical contact tank.

The outlet pipe of the biochemical contact tank is connected to the secondary settling tank, and a sludge return system is provided at the bottom of the secondary settling tank, and a part of the sludge flows back into the biochemical contact tank.

The water after the sedimentation treatment in the secondary settling tank passes through the overflow weir and then discharges up to the standard.

The decolorizing and dephosphorizing agent is prepared by mixing diatomite, activated carbon, bentonite, iron salt, calcium sulfate, aluminum sulfate, and organic flocculant in a mass ratio of 50:20:50:45:40:30:5.

A method for wastewater treatment using the above-mentioned phosphorus-containing printing and dyeing wastewater treatment device has the following steps:

① Phosphorus-containing printing and dyeing wastewater enters the wastewater regulating tank through the inlet pipe of the wastewater regulating tank to adjust the pH value, water quality and water volume of the wastewater.

②The adjusted water enters the decolorization and phosphorus removal pool 1 through the decolorization and phosphorus removal pool inlet pipe 1-3 at the bottom of the decolorization and phosphorus removal pool mixing zone 1-1, and mixes with the decolorization and phosphorus removal agent from the chemical liquid addition system 1-4, Use the stirring device 1-5 set in the middle of the stirring zone to stir; the decolorization and dephosphorization agent removes the color and a certain amount of phosphorus of the wastewater through coagulation, precipitation and adsorption, and then the wastewater enters the wastewater flow of the precipitation zone 1-2 Road, the three-phase separator 1-7 in the sedimentation area realizes the separation of mud and water.

③The sludge sinks under the action of gravity to the lower part of the sedimentation zone 1-2 of the decolorization and phosphorus removal tank, and is discharged through the sediment discharge valve 1-9 at the bottom. The waste water is connected to the anoxic anaerobic reaction tank inlet pipe 2-5 of the anoxic anaerobic reaction tank 2 through the overflow weir 1-8, the outlet pipe and the connecting pipe.

④The waste water enters the lower part of the anoxic anaerobic reaction pool 2 through the anoxic anaerobic reaction pool inlet pipe 2-5 of the anoxic anaerobic reaction pool and the oxygen section 2-2; the waste water enters the anoxic anaerobic reaction pool and then flows along The plate 2-1 advances up and down, and passes through the sludge bed of each reaction chamber of the facultative section 2-2, the anoxic section 2-3 and the anaerobic section 2-4 in turn, and the sludge in the reaction pool goes up and down with the wastewater The movement of the flow and the rise of biogas, the blocking effect of the baffle plate 2-1 and the sedimentation of the sludge itself reduce the flow rate of the sludge, so a large amount of sludge is trapped in the reaction tank, and the sludge in the reaction tank Microorganisms are in full contact with organic matter in wastewater. The facultative bacteria in the facultative stage 2-2, the heterotrophic bacteria in the anoxic stage 2-3 and the anaerobic stage 2-4 hydrolyze the organic matter in the wastewater into organic acids, and decompose the macromolecular organic matter into small molecular organic matter. Organic matter is converted into soluble organic matter.

⑤ The waste water after the anaerobic reaction is separated from mud, water and methane by the three-phase separator 2-6 at the end of the anaerobic section 2-4, and the sludge sinks under the action of gravity to the anoxic anaerobic reaction In the lower part of the pool, excess sludge is discharged through the sludge discharge valve 2-8 at the bottom. The methane waste gas produced by the anoxic anaerobic reaction tank is collected and discharged through the gas collecting pipe 2-10 on the top of the reaction tank. The waste water is connected to the biochemical contact tank inlet pipe of the biochemical contact tank 3 through the overflow weir, the outlet pipe and the connecting pipe.

⑥The waste water enters the middle and lower part of the biochemical contact tank 3 through the water inlet pipe 3-1 of the biochemical contact tank, and the water is evenly distributed under the action of the water distribution triangle cone 3-2. Type aeration disc, produce a large amount of micro-bubbles, the dissolved oxygen measurement and control device regulates the work of the blower according to the oxygen capacity to ensure that the dissolved oxygen in the biochemical contact pool water is greater than 2mg/L, and the treated wastewater passes through the overflow weir 3-5 and The outlet pipe is flowing out.

⑦ The outlet pipe of the biochemical contact tank 3 is connected to the water distribution pipe of the secondary settling tank, and part of the settled sludge in the secondary settling tank flows back to the biochemical contact tank, and part of it is used as excess sludge.

⑧The water after sedimentation treatment in the secondary settling tank passes through the overflow weir of the secondary settling tank and then discharges up to the standard.

⑨Excess sludge from decolorization and phosphorus removal tank 1, anoxic anaerobic reaction tank 2, biochemical contact tank 3 and secondary sedimentation tank is dehydrated and transported abroad.

Inspired by the above-mentioned ideal embodiment according to the present invention, through the above-mentioned description content, relevant workers can make various changes and modifications within the scope of not departing from the technical idea of the present invention. The technical scope of the present invention is not limited to the content in the specification, but must be determined according to the scope of the claims.

Claims (2)

1. A phosphorus-containing printing and dyeing wastewater treatment device, characterized in that: it comprises a wastewater regulating tank, a decolorization and phosphorus removal tank (1), an anoxic anaerobic reaction tank (2), a biochemical contact tank (3), and a secondary sedimentation tank; The wastewater regulating tank includes a wastewater regulating tank inlet pipe, a pH measurement and control system, and a wastewater regulating tank outlet pipe for adjusting the pH value, water quality and water volume of phosphorus-containing printing and dyeing wastewater; The decolorization and dephosphorization pool (1) includes a mixing zone (1-1) and a precipitation zone (1-2). The bottom of the mixing zone is provided with a water inlet pipe (1-3) for the decolorization and dephosphorization tank, and the upper part is provided with a In the chemical solution adding system (1-4) for adding the decolorizing and dephosphorizing agent, a stirring device (1-5) is provided in the middle of the stirring zone; a baffle (1-6) is provided in the precipitation zone, and the baffle is connected with the The inner wall of the decolorization and phosphorus removal tank forms a waste water flow channel for the wastewater to enter the sedimentation area. A three-phase separator (1-7) is installed at the outlet of the sedimentation area, and an overflow weir (1-8) is arranged on the upper part of the outlet of the sedimentation area. The bottom is designed as a conical structure, and a sediment discharge valve (1-9) is set at the bottom of the sedimentation area; The anoxic-anaerobic reaction tank (2) comprises a part-aerobic section (2-2), anoxic section (2-3) and anaerobic section (2-4) separated by a baffle plate (2-1) , the head end of the part-aerobic section (2-2) is provided with an anoxic anaerobic reaction tank inlet pipe (2-5) for feeding waste water, and the end part of the part-aerobic section (2-2) is connected to the anoxic section (2-2) 3) The head end is connected, and the end of the anoxic section (2-3) is connected with the head end of the anaerobic section (2-4); the influent of the anoxic section (2-3) and the anaerobic section (2-4) The lower part of the baffle on one side is provided with a 45-degree corner to avoid the impact of the water flow when it enters, so as to buffer the water flow and distribute water evenly; the end of the anaerobic section (2-4) is equipped with a three-phase separator (2-6) and overflow weir (2-7), overflow weir (2-7) connects outlet pipe; Described concurrent oxygen section (2-2), anoxic section (2-3) and anaerobic section (2 -4) The bottom is designed as a conical structure, and the conical structure is connected to the sludge discharge valve (2-8); ) is designed as a conical structure, and the top of the conical structure is provided with methane waste gas collecting pipes (2-10); The middle and lower part of the biochemical contact pool (3) is provided with a biochemical contact pool water inlet pipe (3-1), and the lower part of the biochemical contact pool water inlet pipe (3-1) is provided with a water distribution triangle cone (3-2); The lower part of the water distribution triangular cone (3-2) is provided with an aeration control system (3-3), and the aeration control system (3-3) includes an aeration pan, a blower and a dissolved oxygen measurement and control device, further, the The aeration pan described above is a microporous aeration pan with micropores uniformly arranged on it; the aeration pan is connected to a blower through an aeration pipe, and the blower is arranged outside the biochemical contact pool, and the upper part of the biochemical contact pool and the wastewater surface are arranged to dissolve An oxygen measurement and control device, the dissolved oxygen measurement and control device regulates the work of the blower according to the oxygen capacity; the upper part of the inlet pipe of the biochemical contact tank is equipped with a filler (3-4); the outlet of the biochemical contact tank is equipped with an overflow weir ( 3-5); The outlet pipe of the biochemical contact tank (3) is connected to a secondary settling tank, and a sludge return system is provided at the bottom of the secondary settling tank, and a part of the sludge flows back into the biochemical contact tank. 2. A method for wastewater treatment using the phosphorus-containing printing and dyeing wastewater treatment device as claimed in claim 1, has the following steps: ①Phosphorus-containing printing and dyeing wastewater enters the wastewater regulating tank through the inlet pipe of the wastewater regulating tank to adjust the pH value, water quality and water volume of the wastewater; ②The adjusted water enters the decolorization and phosphorus removal tank (1) through the decolorization and phosphorus removal pool inlet pipe (1-3) at the bottom of the decolorization and phosphorus removal pool mixing zone (1-1), and is mixed with the chemical solution addition system (1-4 ) is mixed with the decolorizing and dephosphorizing agent, and stirred by the stirring device (1-5) arranged in the middle of the stirring zone; the decolorizing and dephosphorizing agent removes the chroma and a certain amount of phosphorus of the waste water through coagulation, precipitation and adsorption, etc., and then The waste water enters the waste water flow channel of the settling area (1-2), and the three-phase separator (1-7) in the settling area realizes the separation of mud and water; ③The sludge sinks under the action of gravity to the lower part of the sedimentation area (1-2) of the decolorization and dephosphorization tank, and is discharged through the sediment discharge valve (1-9) at the bottom; the waste water passes through the overflow weir (1-8), the outlet The water pipe and the connecting pipe are connected to the anoxic anaerobic reaction tank inlet pipe (2-5) of the anoxic anaerobic reaction tank (2); ④Wastewater enters the lower part of the anoxic anaerobic reaction pool (2) through the anoxic anaerobic reaction pool inlet pipe (2-5) of the anoxic anaerobic reaction pool and the anoxic section; The flow plate (2-1) advances up and down, successively passing through the sludge bed of each reaction chamber of the facultative section (2-2), anoxic section (2-3) and anaerobic section (2-4), and the reaction tank The sludge in the tank moves with the up and down flow of wastewater and the rise of biogas, and the blocking effect of the baffle (2-1) and the sedimentation of the sludge itself reduce the flow rate of the sludge, so a large amount of sludge is Trapped in the reaction tank, the microorganisms in the reaction tank fully contact with the organic matter in the wastewater; facultative bacteria in the facultative section (2-2), anoxic section (2-3) and anaerobic section (2-4) The heterotrophic bacteria in the wastewater hydrolyze organic matter into organic acids, decompose macromolecular organic matter into small molecular organic matter, and convert insoluble organic matter into soluble organic matter; ⑤ After the anaerobic reaction, the three-phase separator (2-6) provided at the end of the anaerobic section (2-4) realizes the separation of mud, water and methane gas, and the sludge sinks to the bottom of the gap under the action of gravity. In the lower part of the anaerobic reaction tank, the excess sludge is discharged through the sludge discharge valve (2-8) at the bottom; the methane waste gas produced by the anoxic anaerobic reaction tank is collected and discharged through the gas collecting pipe (2-10) at the top of the reaction tank; The waste water is connected to the biochemical contact tank inlet pipe of the biochemical contact tank (3) through the overflow weir, the outlet pipe and the connecting pipe; ⑥Wastewater enters the middle and lower part of the biochemical contact tank (3) through the biochemical contact tank water inlet pipe (3-1), and distributes water evenly under the action of the water distribution triangle cone (3-2), and the aeration disc is evenly arranged The microporous aeration disc with micropores produces a large number of microbubbles. The dissolved oxygen measurement and control device regulates the work of the blower according to the oxygen capacity to ensure that the dissolved oxygen in the biochemical contact pool water is greater than 2 mg/L. The treated wastewater passes through the overflow Flow weir (3-5) and outlet pipe flow out; ⑦The outlet pipe of the biochemical contact tank (3) is connected to the water distribution pipe of the secondary settling tank, and part of the settled sludge in the secondary settling tank flows back to the biochemical contact tank, and part of it is used as residual sludge; ⑧The water after sedimentation treatment in the secondary settling tank passes through the overflow weir of the secondary settling tank and then discharges up to the standard; ⑨Excess sludge produced in decolorization and phosphorus removal tank (1), anoxic anaerobic reaction tank (2), biochemical contact tank (3) and secondary sedimentation tank is dehydrated and transported abroad.