CN115417556A

CN115417556A - Anaerobic bioreactor

Info

Publication number: CN115417556A
Application number: CN202210971417.7A
Authority: CN
Inventors: 肖凡; 张�荣; 安猛; 贾希博; 胡伟
Original assignee: Shanghai Dongzhen Environment Protection Engineering & Technology Co ltd
Current assignee: Shanghai Dongzhen Environment Protection Engineering & Technology Co ltd
Priority date: 2022-08-12
Filing date: 2022-08-12
Publication date: 2022-12-02
Anticipated expiration: 2042-08-12
Also published as: CN115417556B

Abstract

The present invention relates to an anaerobic bioreactor comprising: a reactor (1), a water inlet distributor (2), a reflux distributor (3), a circulating pump (4) and a three-phase separator (5); the water inlet distributor (2) is arranged at the bottom of the reactor (1) and uniformly distributes the water inlet treated by the reactor and the reflux liquid conveyed by the circulating pump (4) to the bottom of the reactor; the reflux water distributor (3) is arranged in the middle of the reactor (1), collects the mixed liquid in the reactor and refluxes to the bottom of the reactor through the circulating pump (4) to form continuous internal reflux circulation; the three-phase separator (5) is arranged at the upper part of the reactor (1) and is used for separating mud from water of the mixed liquid. Compared with the prior art, the invention solves the problems of poor separation effect of sludge floc or sludge particles and water and sludge leakage of effluent due to the attachment of fine bubbles by improving the internal flow channel of the separator and additionally arranging measures such as methane backflow stirring and the like.

Description

Anaerobic bioreactor

Technical Field

The invention belongs to the field of environmental engineering and water treatment engineering, and particularly relates to an anaerobic bioreactor.

Background

In the anaerobic biochemical treatment process of the wastewater, organic pollutants in the wastewater are converted into biogas (methane and carbon dioxide gas) under the action of methanogens, so that not only is the degradation of the pollutants realized, but also biomass energy can be recovered.

Common anaerobic methanogenesis reactors in engineering applications include UASB (upflow anaerobic sludge blanket), EGSB (anaerobic expanded granular sludge blanket), IC (internal circulation anaerobic reactor), and the like. Three-phase separators are respectively arranged at the water outlet ends at the tops of the reactors to separate treated effluent, anaerobic sludge and biogas generated by reaction, the separated wastewater flows out of the reactor, the separated anaerobic sludge is intercepted and flows back into the reactor to continue reaction, and the separated biogas is led out of the reactor for utilization through a pipeline. The design and operation effect of the anaerobic bioreactor determine whether the anaerobic reactor can maintain high sludge concentration and treatment load.

In the anaerobic methanogenesis reactor, although most of gas can automatically escape from the mud-water mixed liquor for separation, part of gas is attached to the periphery of sludge flocs or sludge particles in the form of fine bubbles and even enters the inside of the sludge flocs, and enters a three-phase separator together with sludge and wastewater. The specific gravity of the sludge flocs is reduced after the bubbles are carried by the sludge flocs, and the sludge flocs can flow out of the three-phase separator along with water, so that the separation effect is poor. When a large amount of sludge is lost, the concentration of the sludge in the reactor is greatly reduced, and the treatment effect of the reactor on the wastewater is influenced.

Chinese patent CN201310385881.9 discloses an anaerobic sludge bed reactor and a method for treating organic wastewater by using the same, which comprises a three-phase separator arranged at the inner top of a tank type reactor, wherein the three-phase separator comprises a gas-liquid inclined plate separation module and a solid-liquid inclined plate separation module, the top of the solid-liquid inclined plate separation module is provided with a water outlet weir, a separation baffle is arranged between the two groups of inclined plate separation modules, wastewater is pumped into a water inlet main pipe by a reactor feed pump and then enters the reactor through a water distribution distributor, the wastewater flows upwards to pass through a sludge bed layer to carry out biological reaction with anaerobic bacteria to generate a large amount of biogas, and when a mixed liquid rises to a gas-liquid interface, a large amount of biogas is separated from the mixed liquid; the mixed liquid from which most of biogas is separated enters the gas-liquid inclined plate separation module from the top of the gas-liquid inclined plate separation module to realize gas-liquid separation and partial solid-liquid separation, and the biogas flows upwards and is collected at the top of the reactor and finally is sent to a biogas treatment unit for treatment through a biogas pipeline; the mixed liquid further separated out enters a solid-liquid inclined plate separation module to realize solid-liquid separation. The patent adopts the gas-liquid inclined plate separation module to separate the methane and the muddy water mixed liquid, mainly depends on the gravity separation principle, and under the condition that the gas production rate of the anaerobic reactor is larger, the gas-liquid separation is not thorough.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide an anaerobic bioreactor, which can solve the problems of poor separation effect of sludge flocs or sludge particles and water and sludge leakage caused by attachment of fine bubbles by improving an internal flow channel of a separator and adding measures such as methane backflow stirring.

The purpose of the invention can be realized by the following technical scheme: an anaerobic bioreactor comprising: the system comprises a reactor, a water inlet distributor, a reflux distributor, a circulating pump and a three-phase separator;

the reactor be cylindric or cuboid form, the lateral wall bottom is equipped with water inlet and mud discharging port, the lateral wall middle part is equipped with the backward flow export, lateral wall upper portion is equipped with air inlet and delivery port, the top is equipped with the gas outlet.

The water inlet distributor is arranged at the bottom of the reactor, and the water inlet treated by the reactor and the reflux liquid conveyed by the circulating pump are uniformly distributed to the bottom of the reactor;

the reflux water distributor is arranged in the middle of the reactor, collects the mixed liquid in the reactor and refluxes to the bottom of the reactor through the circulating pump to form continuous internal reflux circulation; the purpose of internal reflux circulation is to maintain the ascending flow velocity of the reaction zone in the reactor within the range of 2-8m/h, create a good upflow flow state environment for anaerobic sludge and wastewater, fully contact and react the anaerobic sludge and the wastewater, reduce dead angles of the reaction zone and improve the treatment load of the reactor.

The water inlet distributor and the water return distributor are both in a perforated main branch pipe form.

The three-phase separator is arranged at the upper part of the reactor and is used for separating mud and water of the mixed liquid.

The three-phase separator includes: the device comprises an external partition plate, an internal partition plate, an inclined sedimentation module, a water outlet tank, a mud bucket, a sludge backflow barrier and an aeration pipe;

two inside baffles are arranged between two outside baffles, a water inlet area is arranged between the outside baffles and the inside baffles, the water inlet area is provided with an aeration pipe, a mud-water separation area is arranged between the two inside baffles, an inclined precipitation module is installed in the mud-water separation area, a water outlet area is arranged above the mud-water separation area, a water outlet groove is installed in the water outlet area, a mud bucket is arranged below the mud-water separation area, and a mud backflow baffle is installed at a mud outlet at the bottom of the mud bucket.

The top of the internal clapboard is 0.3-0.5m higher than that of the external clapboard.

The aeration pipe is in a perforated pipe form, the distance of the openings is 50-100mm, the diameter of the openings is 5-10mm, the opening direction is inclined downwards by 45 degrees, and the two sides are uniformly distributed.

The mounting height of the aeration pipe is as follows: the height from the top end of the external clapboard is 0.5-0.8m, and the distance from the bottom end of the internal clapboard is 1.2-1.5m.

The aeration intensity of the aeration pipe is as follows: the aeration intensity of the unit water inlet area surface area is 3-5m ³ /m ² ·h。

The inclined sedimentation module comprises a plurality of inclined plates which are arranged in parallel, the length of each inclined plate is 1-1.2m, the horizontal distance is 50-120mm, and the horizontal inclination angle is 60 degrees.

And a water outlet area is arranged above the mud-water separation area, horizontal triangular weirs are arranged on two sides of the water outlet groove, and the end part of the groove is provided with a connector which is connected with an external water outlet pipe.

The mud bucket is connected with the two external partition plates to form a shell, and the horizontal inclination angle of the mud bucket is 50-60 degrees.

A gap is reserved between the sludge backflow barrier and the mud bucket, the width of the gap is 150-250mm, and the precipitated sludge flows back into the reactor from the gap between the sludge backflow barrier and the mud bucket; meanwhile, the sludge backflow barrier also prevents the mixed liquor from directly entering the anaerobic bioreactor from the bottom of the sludge hopper.

The three-phase separator is of a symmetrical structure: along the center pin bilateral symmetry promptly, can divide into intake zone (gas-liquid separation district), mud-water separation district, play water zone, mud backward flow district, and outside baffle has 2, and the district between its and the inside baffle is intake the district, intakes the upper portion in the district in the left and right sides, all installs the aeration pipe, and the district's aeration pipe mounted height of intaking has broken the mode of traditional bottom aeration, installs on separator upper portion: the height from the liquid level of the reactor (the top end of the external clapboard) is 0.5-0.8m, and the aeration intensity of the aeration pipe in the water inlet area is as follows: the aeration intensity of the unit water inlet area surface area is 3-5m ³ /m ² ·h。

One three-phase separator can be installed in the reactor, and a plurality of three-phase separators can also be installed at the same height.

The gas outlet at the top of the reactor is sequentially connected with the biogas water seal tank, the biogas dewatering tank and the biogas gas holder through pipelines, a branch pipeline is arranged on a gas outlet pipeline of the biogas gas holder and connected with a gas inlet of the three-phase separator, and a biogas booster fan is arranged on the branch pipeline, so that fine bubbles mixed in the mixed liquid can be effectively driven, and the mud-water separation effect is promoted. Except that a part of the marsh gas in the marsh gas cabinet is subjected to reflux circulation, the rest marsh gas is conveyed to a marsh gas disposal and utilization device.

Compared with the prior art, the invention has the following advantages:

(1) The anaerobic bioreactor can treat various wastewater containing high-concentration organic matters, and can operate under higher treatment load due to the high-efficiency separation effect of the three-phase separator. In the invention, the COD treatment volume load of the anaerobic bioreactor can reach 6-10kgCOD/m when the reactor is internally provided with flocculent sludge ³ D, when the reactor is filled with granular sludge, the COD/m can reach 15-20kgCOD/m ³ D. The COD treatment volume load of the common anaerobic bioreactor is 2-6kgCOD/m ³ ·d。

(2) The anaerobic bioreactor can solve the problems of poor separation effect of sludge flocs or sludge particles and water and sludge leakage of effluent due to attachment of fine bubbles by improving an internal flow passage of the separator and additionally arranging measures such as methane backflow stirring and the like.

(2) According to the three-phase separator arranged in the anaerobic bioreactor, the aeration pipe is arranged at the upper part of the water inlet area of the three-phase separator, and the sludge-water mixed liquor is stirred to drive and remove fine bubbles in the mixed liquor, so that a better sludge-water precipitation separation effect is obtained, and the problem of sludge leakage of the effluent of the anaerobic reactor is solved. The sludge-water separation zone is provided with the precipitation module, so that the treatment load of the anaerobic bioreactor is improved by more than 50 percent compared with the technical products of the same type, namely the treatment water quantity of the anaerobic bioreactor is improved by more than 50 percent compared with the technical products of the same type. In addition, the problem of sludge leakage of effluent of the anaerobic reactor is solved, so that higher sludge concentration can be kept in the reactor, and higher pollutant degradation capability is realized. In addition, the concentration of the suspended substances in the effluent of the reactor is reduced (the suspended substances in the effluent can be lower than 50 mg/L), so that the influence of the suspended substances in the effluent on the post-stage treatment process can be greatly reduced.

(3) The gas of outside input can not cause the rising of gas concentration in the mixed liquid, can not cause the influence to the separation of mud floc and water, can not influence anaerobic sludge's in the anaerobic reactor activity, can not cause the influence to getting rid of pollutant in the waste water. The reason is that:

a. the aeration pipe adopts a perforation aeration mode, the diameter of an opening of the perforation pipe is 5-10mm, the size of bubbles is large, and the aeration mainly plays a role in stirring and driving fine bubbles.

b. The aeration pipe is arranged at the upper part in the water inlet area, the height of the installation position of the aeration pipe from the liquid level of the reactor is 0.5-0.8m, and the distance from the bottom of the internal clapboard is 1.2-1.5m. Namely, the aeration in the water inlet area can be regarded as surface layer aeration, and the disturbance influence on the flow guide area at the lower part of the water inlet area is not caused.

C. The aeration gas source adopts the methane generated in the anaerobic biological treatment process of the wastewater, and the activity of anaerobic sludge is not influenced.

Drawings

FIG. 1 is a schematic view of the structure of an anaerobic bioreactor according to the present invention;

FIG. 2 is a state diagram of a three-phase separator in a reactor;

FIG. 3 is a schematic plan view of a three-phase separator;

FIG. 4 isbase:Sub>A cross-sectional view taken along line A-A of FIG. 3;

FIG. 5 is a cross-sectional view taken along line B-B of FIG. 3;

FIG. 6 is a schematic perspective view of an anaerobic bioreactor;

FIG. 7 is a perspective view of an anaerobic bioreactor;

in the figure: 1-a reactor, 2-a water inlet distributor, 3-a reflux distributor, 4-a circulating pump, 5-a three-phase separator, 6-a methane water-sealed tank, 7-a methane dehydration tank, 8-a methane gas cabinet and 9-a methane booster fan;

11-a water inlet, 13-a backflow outlet, 14-an air inlet, 15-a water outlet, 12-a sludge discharge port, 16-an air outlet and 17-a methane outlet;

51-external partition board, 52-internal partition board, 53-inclined plate sedimentation module, 54-water outlet tank, 55-mud bucket, 56-mud reflux barrier and 57-aeration pipe.

Detailed Description

The following examples are given for the detailed implementation and the specific operation procedures, but the scope of the present invention is not limited to the following examples.

Example 1

As shown in fig. 1, an anaerobic bioreactor comprises: the system comprises a reactor 1, a water inlet distributor 2, a reflux distributor 3, a circulating pump 4 and a three-phase separator 5;

the reactor 1 is in a cylindrical or cuboid form, a water inlet 11 and a sludge discharge port 12 are formed in the bottom of the side wall, a backflow outlet 13 is formed in the middle of the side wall, an air inlet 14 and a water outlet 15 are formed in the upper portion of the side wall, and an air outlet 16 is formed in the top of the side wall.

The water inlet distributor 2 is arranged at the bottom of the reactor 1, and evenly distributes the water inlet treated by the reactor and the reflux liquid conveyed by the circulating pump 4 to the bottom of the reactor;

the reflux water distributor 3 is arranged in the middle of the reactor 1, collects the mixed liquid in the reactor and refluxes to the bottom of the reactor through the circulating pump 4 to form continuous internal reflux circulation; the purpose of internal reflux circulation is to maintain the ascending flow velocity of the reaction zone in the reactor within the range of 2-8m/h, create a good upflow flow state environment for anaerobic sludge and wastewater, fully contact and react the anaerobic sludge and the wastewater, reduce dead angles of the reaction zone and improve the treatment load of the reactor.

The water inlet distributor 2 and the water return distributor 3 are both in a perforated mother branch pipe form.

The three-phase separator 5 is installed at the upper part of the reactor 1, and separates sludge and water from the mixed liquid, as shown in fig. 2.

The top of the reactor 1 is a gas collecting area, a top gas outlet 16 is sequentially connected with a methane water seal tank 6, a methane dehydration tank 7 and a methane gas cabinet 8 through pipelines, a gas outlet pipeline connected with a methane outlet 17 of the methane gas cabinet 8 is provided with a branch pipeline, the branch pipeline is connected with a gas inlet 14 of a three-phase separator 5, and a methane booster fan 9 is arranged on the branch pipeline, so that methane generated in the reaction process of fine bubbles mixed in the mixed liquid can be effectively driven, and the sludge-water separation effect is promoted. Except that a part of the marsh gas in the marsh gas cabinet is subjected to backflow circulation, the rest marsh gas is conveyed to a marsh gas disposal and utilization device.

Wherein, the three-phase separator 5 is in a bilateral symmetry structure, and the anaerobic bioreactor is divided into a water inlet area (gas-liquid separation area), a mud-water separation area, a water outlet area and a sludge reflux area. As shown in fig. 3-7:

the three-phase separator 5 specifically includes: two external partition plates 51, two internal partition plates 52, an inclined sedimentation module 53, a water outlet tank 54, a mud bucket 55, a mud backflow barrier 56 and an aeration pipe 57;

wherein, two internal baffles 52 are arranged between the two external baffles 51, a water inlet area is arranged between the external baffles 51 and the internal baffles 52, and the top of the internal baffle 52 is 0.3-0.5m higher than the top of the external baffle 51. The aeration pipes 57 are arranged at the upper parts of the left and right water inlet areas, the aeration pipes 57 are in a perforated pipe form, the spacing between the holes is 50-100mm, the diameter of the holes is 5-10mm, the spacing between the holes is 80mm in the embodiment, the diameter of the holes is 8mm, the direction of the holes inclines downwards 45 degrees, the aeration pipes are uniformly distributed at two sides, and the end parts of the aeration pipes 57 are provided with connectors connected with external air inlet pipes. The installation height of the aeration pipe 57 is: from the external baffle 51 (i.e. reactor liquid)Face) of 0.5 to 0.8m (0.6 m in this example) and at a distance of 1.2 to 1.5m (1.4 m in this example) from the bottom end of the internal partition 52. Aeration intensity of an aeration pipe in the water inlet area: the aeration intensity of the unit water inlet area surface area is 3-5m ³ /m ² H (4 m in this example) ³ /m ² ·h)。

A muddy water separation area is formed between the two inner partition plates 52, an inclined precipitation module 53 is installed in the muddy water separation area, the inclined precipitation module 53 comprises a plurality of inclined plates (as shown in fig. 5) which are arranged in parallel, the length of each inclined plate is 1-1.2m, the horizontal distance is 50-120mm, in the embodiment, the length of each inclined plate is 1.1mm, the horizontal distance is 100mm, and the horizontal inclination angle is 60 degrees. The processing load of the separation zone inclined settling module 53 is: when the inside of the anaerobic reactor is flocculent sludge, the treatment load is 2-4m ³ /m ² H. When the granular sludge is in the anaerobic reactor, the treatment load is 4-8m ³ /m ² ·h。

And a water outlet area is arranged above the mud-water separation area, a water outlet groove 54 is arranged in the water outlet area, horizontal triangular weirs are arranged on two sides of the water outlet groove 54, and a connector is arranged at the end part of the groove and connected with an external water outlet pipe.

A hopper 55 is arranged below the mud-water separation area, the hopper 55 is connected with two external partition plates 51 to form a shell, and the horizontal inclination angle of the hopper 55 is 50-60 degrees (55 degrees in the embodiment). A sludge return baffle 56 is arranged at a sludge outlet at the bottom of the sludge hopper 55. A gap is left between the sludge backflow barrier 56 and the mud bucket 55, and the width of the gap is 150-250mm (200 mm in the embodiment). The precipitated sludge flows back to the reactor from the sludge backflow barrier and the gap of the sludge hopper; meanwhile, the sludge backflow barrier also prevents the mixed liquor from directly entering the anaerobic bioreactor from the bottom of the sludge hopper.

In use, if the anaerobic bioreactor is installed at the upper part of the anaerobic reactor 1, the upper part of the anaerobic bioreactor is a gas collecting area a (as shown in figure 2).

Firstly, mixed liquid consisting of waste water, sludge and fine bubbles enters an inlet water distributor 12 from a water inlet 11 at the bottom of a reactor 1, and reflux liquid treated by the reactor and conveyed by a circulating pump 4 is uniformly distributed to the bottom of the reactor through the inlet water distributor 12 and then flows upwards;

under the action of anaerobic microorganisms in the reaction zone, organic matters in the wastewater are decomposed and converted into biogas, and the main components of the biogas are methane and carbon dioxide. Most of the biogas generated by the reaction actively escapes from the water phase and directly enters a gas collecting area a at the top of the reactor. A small part of the fine bubbles enter the three-phase separator 5 together with the sludge-water mixed liquid and flow into the water inlet area from the upper part of the external partition plate 51. The aeration pipe 57 of the water inlet area is filled with gas, and the aeration pipe has the function of aerating and stirring the mixed liquid in the water inlet area, so that fine bubbles attached around the sludge or inside the sludge floc are separated, and the fine bubbles are driven to the gas collecting area.

The slurry-water mixture is aerated and agitated to remove fine air bubbles, passes downward through the diversion area at the lower part of the water inlet area, and then flows upward into the slurry-water separation area from the lower part of the internal partition plate 52. In the mud-water separation zone, the sludge is separated from the water by the inclined precipitation module 53. The separated water continues to flow upward into the effluent zone, flows through the horizontal triangular weir into the effluent trough 54 for collection, and then flows out of the anaerobic reactor. The separated sludge enters the sludge hopper 56 downwards and flows back to the reactor from the gap between the sludge backflow barrier 56 and the sludge hopper 55, and pollutants in the wastewater are continuously decomposed.

Under the stirring and driving action of the externally returned methane, fine bubbles in the sludge are forcibly separated from the sludge and carried into a gas collecting area at the top of the reactor by large-size bubbles.

After the fine bubbles are driven and separated, the mud-water mixed liquid enters the inclined plate separation module to complete mud-water separation. The separated water flows out of the reactor through a water outlet 15, and the settled sludge flows back to the lower part of the reactor.

Due to the high-efficiency separation effect of the three-phase separator, the anaerobic bioreactor can operate under a higher treatment load. In the invention, the COD treatment volume load of the anaerobic bioreactor can reach 6-10kgCOD/m when the reactor is internally provided with flocculent sludge ³ D, when the reactor is filled with granular sludge, the COD/m can reach 15-20kgCOD/m ³ D. The COD treatment volume load of the common anaerobic bioreactor is 2-6kgCOD/m ³ ·d。

Comparative example 1

The sludge-water separation zone was not equipped with the inclined settling module 53, as in example 1.

Comparative example 2

The upper part of the water intake zone was not provided with the aeration tube 57 as in example 1.

Application example 1

The anaerobic bioreactors of example 1 and comparative examples 1 and 2 were used to treat organic waste liquid in the electronics industry, respectively, with the COD concentration of the reactor feed water being 8370mg/L.

The reactor is a cylinder made of carbon steel, the diameter of the reactor is 6m, the total height of the reactor is 19m, and the effective water depth is 18m.

The bottom of the reactor is provided with a water inlet distributor which is in a perforated main branch pipe form, and the height from the bottom of the tank is 0.5m.

A reflux water distributor is arranged at the middle upper part of the reactor, the reflux water distributor is in a perforated mother branch pipe form, and the height from the bottom of the tank is 14.5m.

The flow rate of the internal reflux circulating pump is 100m ³ The upflow velocity of the reaction zone in the reactor was maintained at 4.2m/h.

A first operation stage: flocculent anaerobic sludge is arranged in the reaction zone, and the wastewater treatment quantity Q =20m ³ /h。

And a second operation stage: the flocculent sludge in the reaction zone is gradually converted into anaerobic granular sludge, the grain diameter of the granular sludge is 1-35mm, and the wastewater treatment quantity Q =42m ³ /h。

The upper part of the reactor is provided with a three-phase separator, the height of an overflow trough in the three-phase separator is equal to the liquid level of the reactor, and the height from the overflow trough to the bottom of the reactor is 18m.

An inclined plate precipitation module is arranged in a separation area of the three-phase separator, and the size of the module is 4m in length, 2m in width and 0.87m in height. The inclined plates are arranged in parallel, the length of each inclined plate is 1.2m, the horizontal distance is 80mm, and the horizontal inclination angle is 60 degrees.

The aeration intensity of the water inlet area of the three-phase separator is 3m ³ /m ² H, the aeration medium is the methane generated by the self reaction of the reactor.

The main body material of the three-phase separator is glass fiber reinforced plastics.

The effluent quality of the anaerobic bioreactor of the example 1 and the comparative examples 1 and 2 is as follows:

therefore, the anaerobic bioreactor is suitable for running both flocculent sludge and anaerobic granular sludge. When the sludge is operated under the condition of flocculent sludge, the COD treatment load is 7.9kgCOD/m ³ D, the removal rate of COD reaches 90.3% -92.3%; when the sludge is operated under the anaerobic granular sludge condition, the COD treatment load is 16.6kgCOD/m ³ D, the COD removal rate is increased to 93.1% -94.3%. And under the two operating conditions, the SS of the effluent of the reactor is lower than 150mg/L.

In the case of comparative example 1, in which the inclined settling module was not installed, the amount of the reactor treatment water was reduced to 3.6m in order to reduce the SS concentration of the reactor effluent as much as possible ³ H (flocculent sludge) and 6.4m ³ (granular sludge). Although comparative example 1 still had a high COD removal rate, the sludge concentration in the reactor was greatly reduced compared to example 1, and the treatment load and the amount of treated water were also greatly reduced.

In the case of comparative example 2 without installing an aeration tube, the amount of water treated by the reactor was the same as in example 1. However, when the comparative example 2 is operated under the working conditions of flocculent sludge and granular sludge, the SS concentration of the effluent of the reactor is higher than that of the example 1, which shows that the sludge loss of the comparative example 2 is larger, so that the sludge concentration of the reaction zone of the comparative example 2 is lower than that of the example 1. This is probably the main reason why the COD of the treated effluent of comparative example 2 is higher than that of example 1.

Therefore, the inclined precipitation module is arranged in the mud-water separation area, so that the water treatment amount of the three-phase separator can be greatly improved. And the aerator pipe is arranged at the upper part of the water inlet area of the separator to disturb the sludge-water mixed liquid, so that tiny bubbles carried in sludge are promoted to escape, and the SS concentration of effluent of the three-phase separator can be effectively reduced, thereby improving the sludge concentration and the COD removal rate in the anaerobic reactor.

Application example 2

Three sets of anaerobic bioreactors of the invention are adopted to treat wastewater of a paper mill, and the COD concentration of inlet water of the reactors is 3300-3600 mg/L. And compared with the anaerobic bioreactors of the structures described in comparative examples 1 and 2 under the same conditions.

The three sets of reactors are all cylindrical tower type anaerobic reactors and adopt an anaerobic granular sludge operation mode. The bottom of the reactor is provided with a water inlet distributor, and the middle upper part is provided with a reflux distributor. The upper part of the reactor is provided with a mud-water separation device, and the height of an overflow trough in the mud-water separation device is equal to the liquid level of the reactor. An inclined plate precipitation module is arranged in a separation area of the mud-water separation device. The inclined plates are arranged in parallel, the length of each inclined plate is 1.2m, and the horizontal inclination angle is 60 degrees. The main body material of the mud-water separation device is glass fiber reinforced plastics.

The different parameters of the three sets of reactors of example 1 and comparative example 2 are as follows:

the effluent quality of the three reactors is as follows:

as can be seen, the three reactors in example 1 all achieve better COD removal effect under different operation loads, the COD removal rate reaches 78.2% -82.9%, and SS (suspended solid) of effluent of the reactors is lower than 150mg/L.

In the case of comparative example 1 without installing the inclined precipitation module, in order to avoid the condition of large amount of sludge leakage in the effluent of the reactor, the operation load of the reactor is reduced to 2.0-3.5 kgCOD/m ³ D was run, but the reactor effluent SS was still higher than in example 1.

Under the condition that the aerator pipe is not arranged in the comparative example 2, under three different operating load working conditions, the SS concentration of the effluent of the reactor in the comparative example 2 is higher than that in the example 1, and the COD concentration of the effluent is slightly higher than that in the example 1.

Therefore, the aeration pipe is arranged in the water inlet area of the three-phase separator, the SS concentration of the effluent of the three-phase separator can be effectively reduced, and the COD removal rate of the anaerobic reactor is improved.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. An anaerobic bioreactor, comprising: the device comprises a reactor (1), a water inlet distributor (2), a reflux distributor (3), a circulating pump (4) and a three-phase separator (5);

the water inlet distributor (2) is arranged at the bottom of the reactor (1) and uniformly distributes the water inlet treated by the reactor and the reflux liquid conveyed by the circulating pump (4) to the bottom of the reactor;

the reflux water distributor (3) is arranged in the middle of the reactor (1), collects the mixed liquid in the reactor and refluxes to the bottom of the reactor through the circulating pump (4) to form continuous internal reflux circulation;

the three-phase separator (5) is arranged at the upper part of the reactor (1) and is used for separating mud from water of the mixed liquid.

2. The anaerobic bioreactor according to claim 1, characterized in that the bottom of the side wall of the reactor (1) is provided with a water inlet (11) and a sludge outlet (12), the middle part of the side wall is provided with a reflux outlet (13), the upper part of the side wall is provided with an air inlet (14) and a water outlet (15), and the top is provided with an air outlet (16).

3. The anaerobic bioreactor according to claim 1, characterized in that the inlet distributor (2) and the return distributor (3) are in the form of perforated mother pipes.

4. The anaerobic bioreactor according to claim 1, characterized in that the three-phase separator (5) comprises an external baffle (51), an internal baffle (52), an inclined settling module (53), an effluent tank (54), a mud bucket (55), a sludge return baffle (56), an aeration pipe (57); two inside baffles (52) are arranged between two outside baffles (51), a water inlet area is arranged between the outside baffles (51) and the inside baffles (52), an aeration pipe (57) is arranged in the water inlet area, a mud-water separation area is arranged between the two inside baffles (52), an inclined precipitation module (53) is arranged in the mud-water separation area, a water outlet area is arranged above the mud-water separation area, a water outlet groove (54) is arranged in the water outlet area, a mud hopper (55) is arranged below the mud-water separation area, and a mud backflow baffle (56) is arranged at a mud outlet at the bottom of the mud hopper (55).

5. The anaerobic bioreactor according to claim 4, wherein the top of the inner partition (52) is 0.3-0.5m higher than the top of the outer partition (51).

6. The anaerobic bioreactor according to claim 4, wherein the aeration pipe (57) is in the form of perforated pipe, the distance between the openings is 50-100mm, the diameter of the openings is 5-10mm, the direction of the openings is 45 ° downward and the openings are uniformly distributed on both sides.

7. The anaerobic bioreactor according to claim 4, wherein the aerator pipe (57) is installed at a height of: the height from the top end of the external partition board (51) is 0.5-0.8m, and the distance from the bottom end of the internal partition board (52) is 1.2-1.5m.

8. The anaerobic bioreactor according to claim 1, wherein the inclined settling module (53) comprises a plurality of inclined plates arranged in parallel, the inclined plates having a length of 1-1.2m, a horizontal spacing of 50-120mm, and a horizontal inclination angle of 60 °.

9. The anaerobic bioreactor of claim 1, wherein horizontal triangular weirs are arranged on both sides of the outlet tank (54), and the end of the tank is provided with a port connected with an external outlet pipe;

the mud bucket (55) is connected with the two external partition plates (51) to form a shell, and the horizontal inclination angle of the mud bucket (55) is 50-60 degrees;

a gap is reserved between the sludge backflow barrier (56) and the sludge bucket (55), and the width of the gap is 150-250mm.

10. The anaerobic bioreactor according to claim 1, wherein the gas outlet at the top of the reactor (1) is connected with a biogas sealing tank (6), a biogas dewatering tank (7) and a biogas tank (8) in sequence through pipelines, a branch pipeline is arranged on the gas outlet pipeline of the biogas tank (8), the branch pipeline is connected with the gas inlet of the three-phase separator (5), and a biogas booster fan (9) is arranged on the branch pipeline.