CN111661920B

CN111661920B - Application of biofilm reactor

Info

Publication number: CN111661920B
Application number: CN202010535279.9A
Authority: CN
Inventors: 隋军; 曹辉
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-06-12
Filing date: 2020-06-12
Publication date: 2023-04-14
Anticipated expiration: 2040-06-12
Also published as: CN111661920A

Abstract

The invention relates to application of a biofilm reactor, and belongs to the technical field of sewage treatment. The biomembrane reactor is applied to sewage treatment, because the air or oxygen in the hollow breathable membrane pipe can directly supply oxygen to the biomembrane growing on the outer cladding fiber of the composite membrane pipe in a diffusion way, the utilization efficiency of the oxygen can be efficiently improved, and the part of the biomembrane growing on the outer cladding fiber layer of the composite membrane pipe is close to the part of the biomembrane growing on the inner side of the membrane pipe because the oxygen is supplied to the biomembrane in a diffusion way, the part of the biomembrane close to the water body is provided with anoxic bacteria growing according to the difference of the air or oxygen pressure in the hollow breathable membrane pipe, so that the biomembrane with the internal aerobic and external anoxic biomembrane is formed, and the simultaneous nitrification and denitrification functions are achieved. Has better sewage treatment effect and can greatly reduce energy consumption.

Description

Application of biofilm reactor

Technical Field

The invention relates to the technical field of sewage treatment, in particular to an application of a biofilm reactor.

Background

Along with the continuous improvement of the urbanization and industrialization degree of China, the water consumption is increased day by day, and the generated sewage quantity is increased. The country also puts higher requirements on the pollution discharge standard and regulation, and further increases the operation cost.

In the current practice, the sewage is treated by adopting a traditional biochemical tank, the occupied area is extremely large, and the treatment time is long. The treatment by the traditional method, as shown in figure 1, needs to stay in anaerobic, anoxic and aerobic tanks for a period of time respectively to meet the treatment requirements of biochemical water tanks.

Disclosure of Invention

In view of the above, there is a need to provide an application of a biofilm reactor to sewage treatment with high treatment efficiency and stable treatment effect in view of the above problems.

Use of a biofilm reactor in wastewater treatment, the biofilm reactor comprising: oxygen transfer biomembrane reaction unit, frame, upper air pipe, lower air pipe and air source,

the oxygen transfer biological membrane reaction unit comprises an internal oxygen supply hollow breathable composite membrane tube, a combined tube assembly part and a support tube, wherein the internal oxygen supply hollow breathable composite membrane tube comprises a breathable membrane tube and a fiber layer covering the outer surface of the breathable membrane tube, the breathable membrane tube is made of a non-biodegradable material, uniform micropores are formed in the breathable membrane tube, and the pore diameter of each micropore is 0.01-30 mu m; the fiber layer is made of at least one of polyester resin and high-density polyethylene, the thickness of the fiber layer is 0.1-2.6mm, and the fiber layer is provided with a pore structure; the combined pipe assembly part comprises two rubber-pouring parts and two connecting parts, two ends of a plurality of inner oxygen supply hollow breathable composite membrane pipes are respectively fixed in the two rubber-pouring parts, the inner cavity of each inner oxygen supply hollow breathable composite membrane pipe is opened on the surface of each rubber-pouring part, each connecting part comprises a shell, each shell is fixedly connected with the corresponding rubber-pouring part and covers the inner cavity opening of the inner oxygen supply hollow breathable composite membrane pipe on the corresponding rubber-pouring part, a ventilation cavity is arranged in each shell and is communicated with the inner cavity of the inner oxygen supply hollow breathable composite membrane pipe, and the surface of each shell is provided with an air inlet and/or an air outlet; two ends of the supporting tube are respectively fixedly installed with the two connecting pieces;

the oxygen transfer biomembrane reaction units are fixedly arranged in the frame, the upper air pipe is communicated with an air inlet or an air outlet of an upper connecting piece of the oxygen transfer biomembrane reaction unit, the lower air pipe is communicated with an air outlet or an air inlet of a lower connecting piece of the oxygen transfer biomembrane reaction unit, and the air source is communicated with the upper air pipe or the lower air pipe.

In one embodiment, the fiber layer is made of a linear material wound and woven on the surface of the inner pipe; or the fiber layer is prepared by winding a film material on the inner pipe and then sintering; or the fiber layer is prepared by coating a coating material on the outer surface of the inner pipe and cooling.

For example, the specific steps for preparing the fiber layer by weaving method are as follows: winding and weaving a linear material of high-density polyethylene and/or polyester resin on the surface of the breathable membrane tube by a weaving machine to obtain a material with the thickness of 0.1-2.6mm, so as to obtain a fiber layer; it can be understood that the thickness and density of the weave can be adjusted by a weaving machine according to the specific working condition requirements, so that the surface of the membrane can keep the required gaps for the subsequent biofilm reactor.

The specific steps for preparing the fiber layer by the sintering method are as follows: and winding the high-density polyethylene and/or polyester resin film with micropores on the inner pipe, heating to a preset temperature, and sintering the high-density polyethylene and/or polyester resin film and the inner pipe into a whole to obtain the fiber layer.

The specific steps for preparing the fiber layer by the coating method are as follows: and preparing the coating material into liquid, coating the liquid on the outer surface of the inner tube by using a coating machine, and cooling to obtain the fiber layer. In the coating method, because the material has gaps, the surface of the material can be normally passed by gas and liquid after cooling.

The invention also discloses a sewage treatment method, which adopts the biofilm reactor and comprises the following steps:

equipment installation: putting the biofilm reactor into a biochemical water tank, and fixing;

ventilating: connecting an air source;

water treatment: and adjusting the pressure in the ventilation cavity to be stable according to the preset pressure setting, so that the sewage treatment bacteria are attached to the fiber layer for sewage treatment.

In one embodiment, the water treatment step comprises aerobic treatment according to the following process conditions:

1) Aerobic treatment: controlling the air supply pressure in the aeration cavity to be stable, so that the dissolved oxygen in the first biochemical pool is more than 1mg/L; aerobic bacteria grow and attach to the fiber layer under the action of organic matters and oxygen in the sewage to form biomembrane sludge, and the sewage is subjected to aerobic treatment;

2) Activated sludge precipitation: the sewage after aerobic treatment enters a secondary sedimentation tank for sedimentation, part of biomembrane sludge is carried by water after falling off and enters the secondary sedimentation tank for sedimentation, the tail water at the upper layer is discharged after sedimentation, and the sediment at the lower layer flows back to the first biochemical pool and/or is discharged as residual sludge;

or alternatively

In the water treatment step, denitrification treatment is carried out according to the following process conditions:

1) And (3) anoxic treatment: controlling the air supply pressure in the ventilation cavity to be stable, so that the dissolved oxygen in the first biochemical water tank is 0.1-1.0mg/L; aerobic bacteria and nitrobacteria grow and attach to the fiber layer under the action of organic matters and oxygen in the sewage, aerobic bacteria and nitrobacteria grow in the inner layer of the fiber layer, denitrifying bacteria grow in the outer layer of the fiber layer to form biomembrane sludge, and the sewage is subjected to denitrification treatment;

2) Activated sludge precipitation: and (3) the sewage after denitrification treatment enters a secondary sedimentation tank for sedimentation, part of the biomembrane sludge is carried by water after falling off and enters the secondary sedimentation tank for sedimentation, the tail water at the upper layer is discharged after sedimentation, and the sediment at the lower layer flows back to the first biochemical pool and/or is discharged as residual sludge.

In one embodiment, a plurality of the biofilm reactors are respectively placed in a first biochemical water pool and a second biochemical water pool which are communicated in sequence and are respectively fixed.

In one embodiment, in the water treatment step, the deep denitrification treatment is performed according to the following process conditions:

1) And (3) anoxic treatment: introducing sewage into the first biochemical water tank, and controlling the stable air supply pressure in the ventilation cavity to ensure that the dissolved oxygen in the first biochemical water tank is 0.1-0.6mg/L; aerobic bacteria, nitrobacteria and denitrifying bacteria grow and attach to the fiber layer under the action of organic matters and oxygen in the sewage, the aerobic bacteria and the nitrobacteria grow on the inner layer of the fiber layer, the denitrifying bacteria grow on the outer layer of the fiber layer to form biomembrane sludge, and the sewage is subjected to deep denitrification treatment;

2) Aerobic treatment: guiding the sewage treated by the first biochemical water tank into the second biochemical water tank, and controlling the air supply pressure in the ventilation cavity to be stable, so that the dissolved oxygen in the second biochemical water tank is more than 1.5mg/L; aerobic bacteria grow and attach to the fiber layer under the action of organic matters and oxygen in the sewage to form biomembrane sludge, and the sewage is subjected to aerobic treatment;

3) Activated sludge precipitation: the sewage after aerobic treatment enters a secondary sedimentation tank for sedimentation, part of biomembrane sludge is carried by water after falling off and enters the secondary sedimentation tank for sedimentation, the tail water at the upper layer is discharged after sedimentation, and the sediment at the lower layer flows back to the first biochemical pool and/or is discharged as residual sludge;

or alternatively

In the water treatment step, aerobic dephosphorization treatment is carried out according to the following process conditions:

1) Anaerobic treatment: introducing sewage into the first biochemical water tank, leading the dissolved oxygen amount in the first biochemical water tank to be less than 0.2mg/L, simultaneously carrying out pulse water distribution or arranging a stirring system to enable anaerobic bacteria to be in a suspension state, and carrying out anaerobic treatment on the sewage;

2) Aerobic treatment: guiding the sewage treated by the first biochemical water tank into the second biochemical water tank, and controlling the air supply pressure in the ventilation cavity to be stable so that the dissolved oxygen in the second biochemical water tank is more than 1.5mg/L; aerobic bacteria grow and attach to the fiber layer under the action of organic matters and oxygen in the sewage to form biomembrane sludge, and the sewage is subjected to aerobic treatment;

3) Activated sludge precipitation: the sewage after aerobic treatment enters a secondary sedimentation tank for sedimentation, part of biomembrane sludge is carried by water after falling off and enters the secondary sedimentation tank for sedimentation, the tail water at the upper layer is discharged after sedimentation, and the sediment at the lower layer flows back to the first biochemical water tank and/or is discharged as residual sludge;

or

In the water treatment step, denitrification dephosphorization denitrification treatment is carried out according to the following process conditions:

1) Anaerobic treatment: introducing sewage into the first biological water tank, leading the dissolved oxygen amount in the first biological water tank to be less than 0.2mg/L, simultaneously carrying out pulse water distribution or arranging a stirring system to lead anaerobic bacteria to be in a suspension state, and carrying out anaerobic treatment on the sewage;

2) And (3) anoxic treatment: guiding the sewage treated by the first biochemical water tank into the second biochemical water tank, and controlling the stable air supply pressure in the ventilation cavity to ensure that the dissolved oxygen in the second biochemical water tank is 0.1-0.6mg/L; aerobic bacteria, nitrobacteria and denitrifying bacteria grow and attach to the fiber layer under the action of organic matters and oxygen in the sewage, the aerobic bacteria and the nitrobacteria grow on the inner layer of the fiber layer, the denitrifying bacteria grow on the outer layer of the fiber layer to form biomembrane sludge, and the sewage is subjected to anoxic treatment;

3) Activated sludge precipitation: and (3) allowing the sewage subjected to anoxic treatment to enter a secondary sedimentation tank for sedimentation, allowing part of biomembrane sludge to be carried by water after falling off and enter the secondary sedimentation tank for sedimentation, discharging tail water at the upper layer after sedimentation, and returning the sediment at the lower layer to the first biochemical water tank and/or discharging the sediment as residual sludge.

In one embodiment, in the equipment installation step, a plurality of biofilm reactors are respectively placed into a first biochemical water pool, a second biochemical water pool and a third biochemical water pool which are communicated in sequence and are respectively fixed;

in the water treatment step, dephosphorization and denitrification treatment is carried out according to the following process conditions:

2) And (3) anoxic treatment: guiding the sewage treated by the first biochemical water tank into the second biochemical water tank, and controlling the air supply pressure in the ventilation cavity to be stable so that the dissolved oxygen in the second biochemical water tank is 0.1-0.6mg/L; aerobic bacteria, nitrobacteria and denitrifying bacteria grow and attach to the fiber layer under the action of organic matters and oxygen in the sewage, the aerobic bacteria and the nitrobacteria grow on the inner layer of the fiber layer, the denitrifying bacteria grow on the outer layer of the fiber layer to form biomembrane sludge, and the sewage is subjected to anoxic treatment;

3) Aerobic treatment: introducing the sewage treated by the second biochemical water tank into the third biochemical water tank, and controlling the air supply pressure in the ventilation cavity to be stable so that the dissolved oxygen in the third biochemical water tank is more than 1.5mg/L; aerobic bacteria grow and attach to the fiber layer under the action of organic matters and oxygen in the sewage to form biomembrane sludge, and the sewage is subjected to aerobic treatment;

4) Activated sludge precipitation: and (3) allowing the aerobic-treated sewage to enter a secondary sedimentation tank for sedimentation, carrying part of biomembrane sludge into the secondary sedimentation tank for sedimentation after falling off by water, discharging tail water at the upper layer after sedimentation, and returning the sediment at the lower layer to the first biochemical water tank and/or discharging the sediment as residual sludge.

In one embodiment, the biofilm reactor further comprises an upper control valve and a lower control valve, wherein the upper control valve is arranged on the upper air pipe and used for controlling the ventilation volume of the upper air pipe; the lower control valve is arranged on the lower air pipe and used for controlling the ventilation volume of the lower air pipe flow; and the pressure in the ventilation cavity is stabilized by adjusting the opening degrees of the upper control valve and the lower control valve.

In one embodiment, the biofilm reactor accounts for 10-75% of the volume of the biochemical water pool.

In one embodiment, the oxygen transfer biological membrane reaction unit is 20 curtains and is arranged on two sides of the upper air pipe and the lower air pipe in two groups; the outer diameter of the inner pipe is 1.5 +/-0.3 mm, and the inner diameter of the inner pipe is 0.5 +/-0.2 mm; controlling the air supply quantity of the air source to be 30L/(m) ² .h)。

In one embodiment, the method further comprises a cleaning step, wherein in the cleaning step, the air pressure in the ventilation cavity is increased to a cleaning air pressure, and the sludge attached to the outside of the fiber layer is dispersed and shed.

In one embodiment, the cleaning air pressure is 2-3mpa.

Compared with the prior art, the invention has the following beneficial effects:

when the biofilm reactor is used, the biofilm reactor is placed in a treatment water tank, air or oxygen is supplied into a hollow air-permeable composite membrane tube from one end, on one hand, oxygen is supplied to a biofilm growing on a fiber layer coated outside the composite membrane tube in a diffusion mode, on the other hand, the air or the oxygen can pass through the tube hole of the composite membrane tube, and micro bubbles are formed in water so as to supply oxygen to activated sludge. The size of the pore of the membrane tube is controlled in the processing process, so that the size of the oxygen diffusion or bubble generation, the oxygen supply and the resistance of the membrane tube are controlled in the using process.

Because the air or oxygen in the internal oxygen supply hollow breathable composite membrane tube can directly diffuse and supply oxygen to the biological membrane growing on the fiber layer outside the composite membrane tube, the utilization efficiency of the oxygen can be efficiently improved, and anoxic bacteria, aerobic bacteria and/or nitrobacteria and the like simultaneously grow on the fiber layer by utilizing the oxygen supply amount of the composite membrane tube, thereby playing the role of simultaneous nitrification and denitrification.

When air or oxygen in the hollow breathable membrane tube reaches a certain pressure, the air or oxygen can form micro bubbles in water from the composite membrane tube hole, the generated bubbles are small and uniform, have huge surface areas, have long retention time in water, and can be fully contacted and fused with a water body, the air water oxygen supply rate and the oxygen utilization rate are greatly improved, and the energy consumption can be greatly reduced.

Drawings

FIG. 1 is a schematic view of a conventional sewage treatment method in the background art;

FIG. 2 is a schematic view of the structure of the biofilm reactor in example 1;

FIG. 3 is a schematic diagram of the structure of the oxygen transfer biofilm reaction unit in example 1;

FIG. 4 is a schematic view of the assembly of the oxygen transfer biofilm reaction unit in example 1;

FIG. 5 is a schematic view of a tube of air-permeable membrane in example 1;

FIG. 6 is a schematic view of an internally oxygen-supplying hollow permeable composite membrane tube prepared in example 1;

FIG. 7 is a schematic view showing aerobic treatment of wastewater in example 2;

FIG. 8 is a schematic view showing denitrification treatment of wastewater according to example 2;

FIG. 9 is a schematic view showing the advanced denitrification treatment of wastewater in example 2;

FIG. 10 is a schematic view of aerobic phosphorus removal treatment of wastewater in example 2;

FIG. 11 is a schematic view of the denitrification, dephosphorization and denitrification treatment of the wastewater in example 2;

FIG. 12 is a schematic view of the dephosphorization and denitrification treatment of the wastewater in example 2;

wherein: 100. a hollow breathable composite membrane tube with internal oxygen supply; 110. a gas-permeable membrane tube; 111. micropores; 200. an oxygen transfer biofilm reaction unit; 210, pouring the rubber; 220. a connecting member; 230. supporting a tube; 300. a frame; 410. an upper trachea; 411. an upper control valve; 420. a lower trachea; 421, lower control valve.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully hereinafter with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "coupled" to another element, it can be directly coupled to the other element or intervening elements may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Example 1

A biofilm reactor is shown in FIG. 2, and comprises an oxygen transfer biofilm reaction unit 200, a frame 300, an upper air pipe 410, a lower air pipe 420, an air source, an upper control valve 411 and a lower control valve 421.

An oxygen transfer biofilm reaction unit, as shown in fig. 3, comprising: an internal oxygen supply hollow gas permeable composite membrane tube 100, a composite tube assembly and a support tube 230.

The internal oxygen supply hollow breathable composite membrane tube comprises a breathable membrane tube 110 and a fiber layer covering the outer surface of the breathable membrane tube, wherein the breathable membrane tube is made of a non-biodegradable material and is provided with uniform micropores, and the pore diameter of each micropore is 0.01-30 mu m; the fiber layer is made of at least one of polyester resin and high-density polyethylene, the thickness of the fiber layer is 0.1-2.6mm, and the fiber layer is provided with a pore structure.

The combined pipe assembly part comprises two rubber-pouring parts 210 and two connecting parts 220, two ends of a plurality of inner oxygen supply hollow breathable composite membrane pipes are respectively fixed in the two rubber-pouring parts, and the inner cavities of the inner oxygen supply hollow breathable composite membrane pipes are opened on the surfaces of the rubber-pouring parts; in this embodiment, the piece of falling to glue is the strip, two of interior oxygen suppliment cavity ventilative composite membrane pipes are a set of, follow the piece length direction align to grid of falling to glue. The connecting piece comprises a shell, the shell is fixedly connected with the rubber pouring piece and covers an inner cavity opening of an inner oxygen supply hollow breathable composite membrane pipe on the rubber pouring piece, a ventilation cavity is arranged in the shell and is communicated with the inner cavity of the inner oxygen supply hollow breathable composite membrane pipe, and an air inlet and/or an air outlet are/is formed in the surface of the shell;

and two ends of the supporting tube are fixedly installed with the two connecting pieces respectively. In this embodiment, the number of the support pipes is two, and the two support pipes are respectively arranged at two ends of the connecting piece.

The assembly mode of the oxygen transfer biomembrane reaction unit is as follows:

the two ends of the internal oxygen supply hollow breathable composite membrane tube are respectively and uniformly distributed and then placed into two glue pouring pieces, mixed liquid of epoxy resin and curing agent is poured, after the internal oxygen supply hollow breathable composite membrane tube is completely solidified, the top shell is cut off, the inner hole of the composite tube is exposed, as shown in a diagram A in figure 4, and finally the glue pouring pieces are adhered to the connecting piece, as shown in a diagram B in figure 4.

The internal oxygen supply hollow breathable composite membrane tube is prepared by the following method:

1. and (3) preparing modified polytetrafluoroethylene.

5wt% of silicon dioxide and 5wt% of titanium dioxide are added into the polytetrafluoroethylene raw material as reinforcing agents, so that the raw material cost of the membrane tube can be reduced, and meanwhile, the strength of the membrane tube is greatly improved after the membrane tube is manufactured, so that the use requirement of the biofilm reactor is met.

2. And (5) cold extrusion.

Adding adhesive (10 wt% of white mineral oil) into the modified polytetrafluoroethylene raw material, extruding the mixed raw material from an extrusion port at high pressure from a cold extrusion forming machine in a normal temperature (20-30 ℃) environment (the temperature influences the density of the extruded material), wherein the extrusion port can be replaced or processed to extrude a pipe with the inner diameter of phi 0.5-phi 4mm and the outer diameter of phi 1.5-phi 5 mm.

3. And (4) hot stretching.

The extruded high-density formed air-permeable membrane tube is preheated by a heater, and bypasses two driving wheels with different rotating speeds, and the rotating speed of the rear driving wheel is 1.5-3 times of that of the front driving wheel, so that uniform micropores 111 are stretched out from the high-density air-permeable membrane tube, the size of the stretched micropores can be adjusted by controlling the speed of the front driving wheel and the rear driving wheel, and the pore diameter can be controlled within the range of 0.01-30 mu m, and the air-permeable membrane tube 110 (also called a tubule) is obtained, as shown in fig. 5.

4. And (4) preparing a fiber layer.

The linear material (PP) is wound on the surface of the breathable membrane tube by a standard knitting machine to form a material with the thickness of 0.1-2.6mm, and the knitting thickness and density can be adjusted by the knitting machine, so that the surface of the breathable membrane tube is kept with required gaps and can be used for the biofilm reactor.

In practical work, the problem caused by the material characteristics of the breathable film tube, such as the problem that various glues cannot be adhered and fixed, needs to be solved when the breathable film tube is woven.

Aiming at the problem, the used solution method is as follows: soaking the breathable membrane tube into a mixed solution of alcohol and a Tween 20 emulsifier, taking out, and permeating the mixture remained on the surface into the surface of the breathable membrane tube to improve the friction coefficient of the breathable membrane tube, so that the breathable membrane tube can be woven on a weaving machine, and a layer of linear material is wound.

In the weaving process, in order to reserve space for the survival of microorganisms, 20S yarn count and 65 × 78 density are generally adopted for weaving, namely after 20 × 20/65 × 78 linear materials are woven, gaps are large, the surface is rough, and the formed gaps provide space for the survival of microorganisms.

The hollow permeable composite membrane tube with internal oxygen supply prepared in this example is shown in fig. 6.

The oxygen transfer biomembrane reaction units are fixedly arranged in the frame, the upper air pipe is communicated with an air inlet or an air outlet of an upper connecting piece of the oxygen transfer biomembrane reaction unit, the lower air pipe is communicated with an air outlet or an air inlet of a lower connecting piece of the oxygen transfer biomembrane reaction unit, and the air source is communicated with the upper air pipe or the lower air pipe. The upper control valve is arranged on the upper air pipe and used for controlling the ventilation volume of the upper air pipe flow; the lower control valve is arranged on the lower air pipe and used for controlling the ventilation volume of the lower air pipe flow.

In this embodiment, the oxygen transfer biofilm reaction units are 20 curtains and are arranged on two sides of the upper air pipe and the lower air pipe in two groups.

Example 2

Use of a biofilm reactor in wastewater treatment comprising the steps of:

1. and (4) equipment installation.

The biofilm reactor of example 5, which was completed in the assembly test, was placed in biochemical water tanks (1 to 3 biochemical water tanks may be provided as needed), and fixed.

In this example, the biofilm reactor occupies 10-75% of the volume of the biochemical water pool.

2. And (6) ventilating.

After the upper air pipe and the lower air pipe are respectively connected to the upper control valve and the lower control valve, the lower air pipe is connected to an air source. In this embodiment, the pressure in the vent chamber is stabilized by adjusting the opening degrees of the upper control valve and the lower control valve.

3. And (4) water treatment.

According to different treatment requirements, different water treatment methods are respectively selected for treatment.

1. Aerobic treatment: a biochemical pond (first biochemical pond) was used in combination with the secondary sedimentation tank for treatment, as shown in FIG. 7.

1) Aerobic treatment: controlling the air supply pressure in the ventilation cavity to be stable, so that the dissolved oxygen in the first biochemical water pool is more than 1mg/L; aerobic bacteria grow and attach to the fiber layer under the action of organic matters and oxygen in the sewage to form biomembrane sludge, and the sewage is subjected to aerobic treatment;

2. and (3) denitrification treatment: a biochemical pond (first biochemical pond) was used in combination with the secondary sedimentation pond for treatment, as shown in fig. 8.

1) And (3) anoxic treatment: controlling the air supply pressure in the aeration cavity to be stable, so that the dissolved oxygen in the first biochemical pool is 0.1-1.0mg/L; aerobic bacteria and nitrobacteria grow and attach to the fiber layer under the action of organic matters and oxygen in the sewage, aerobic bacteria and nitrobacteria grow in the inner layer of the fiber layer, denitrifying bacteria grow in the outer layer of the fiber layer to form biomembrane sludge, and the sewage is subjected to denitrification treatment;

3. Deep denitrification treatment: two biochemical ponds (a first biochemical pond and a second biochemical pond) are used in combination with the secondary sedimentation pond for treatment, as shown in fig. 9.

4. aerobic phosphorus removal treatment: two biochemical ponds (a first biochemical pond and a second biochemical pond) are used in combination with the secondary sedimentation pond for treatment, as shown in fig. 10.

5. denitrifying phosphorus and nitrogen removal treatment: two biochemical pools (a first biochemical pool and a second biochemical pool) were used in combination with the secondary sedimentation pool for treatment, as shown in fig. 11.

3) Activated sludge precipitation: and (3) the sewage after the anoxic treatment enters a secondary sedimentation tank for sedimentation, part of biomembrane sludge is carried by water after falling off and enters the secondary sedimentation tank for sedimentation, the tail water at the upper layer is discharged after sedimentation, and the sediment at the lower layer flows back to the first biochemical water tank and/or is discharged as residual sludge.

6. And (3) dephosphorization and denitrification treatment: three biochemical ponds (a first biochemical pond, a second biochemical pond and a third biochemical pond) are used together with a secondary sedimentation pond for treatment, as shown in fig. 12.

4. Cleaning: and increasing the air pressure in the ventilation cavity to 2-3mpa of clean air pressure, and dispersing and falling off the sludge attached to the outside of the fiber layer.

When the hollow breathable composite membrane tube with internal oxygen supply is used, the hollow breathable composite membrane tube is placed in a treatment water tank, air or oxygen is supplied into the hollow breathable membrane tube from one end, on one hand, oxygen is supplied to a biological membrane growing on a fiber layer coated outside the composite membrane tube in a diffusion mode, and on the other hand, the air or the oxygen can pass through the pores of the composite membrane tube to form micro bubbles in water so as to supply oxygen to activated sludge. The size of the film tube hole is controlled in the processing process, so that the size, oxygen supply and resistance of diffusion oxygen supply or bubble generation in the use process of the film tube are controlled.

Because the air or oxygen in the hollow breathable film tube can directly supply oxygen to the biomembrane growing on the outer cladding fiber of the composite film tube by diffusion, the utilization efficiency of the oxygen can be efficiently improved, the part of the biomembrane growing on the outer cladding fiber layer of the composite film tube is close to the membrane tube because aerobic bacteria grow by the oxygen supply of the membrane tube by diffusion, the part of the biomembrane close to the water body by external measurement can grow anoxic bacteria according to the difference of air or oxygen pressure supplied in the hollow breathable film tube, an internal aerobic and external anoxic biomembrane is formed, and the effect of simultaneous nitrification, denitrification and denitrification is achieved.

When air or oxygen in the hollow breathable film tube reaches a certain pressure, the air or oxygen can form tiny bubbles in water from the composite film tube hole, the generated bubbles are tiny and even, have huge surface area, have long retention time in water, and can be fully contacted and fused with a water body, the utilization rate of air water oxygen supply rate and oxygen is greatly improved, and the energy consumption can be greatly reduced.

Moreover, as the working time is prolonged, useless sludge (dead sludge without microorganisms) is gradually adsorbed on the surfaces attached with the microorganisms after 15 days, and the special membrane tubes are required to be backflushed and cleaned regularly to work stably.

For example, 2-3 mpa's gas can be thrown into regularly, control the pressure in the chamber of ventilating promptly and be 2-3mpa, will adhere to the mud on surface and break away and deposit in the bottom of pond because the action of gravity is fast, in the partial microorganism that adheres to the surface scatters the back and reattaches in each environment of membrane tube again, solved mud and excessively piled up and cause the insufficient and overweight scheduling problem of surface of reaction, compare traditional attached bacteria culture, this mode is the peculiar advantage of biofilm reactor, solved the difficult problem that traditional attached bacteria culture exists always.

Example 3

An application of aerobic treatment in the sewage treatment of 10t/h reconstruction by adopting a biofilm reactor comprises the following steps:

1. reactor installation

The biofilm reactor of example 2, which was completed in the assembly test, was fixed in an existing aerobic biochemical water tank, and the packing density was about 70% of the total volume of the water tank.

2. And (4) connecting.

3. And (6) processing.

The scheme adopts an aerobic treatment mode, and aims to improve the biochemical efficiency and effect, reduce the energy consumption and reduce the treatment cost;

aerobic treatment: controlling the air supply pressure in the ventilation cavity to be stable, so that the dissolved oxygen in the first biochemical water pool is more than 1mg/L; aerobic bacteria grow and attach to the fiber layer under the action of organic matters and oxygen in the sewage to form biomembrane sludge, and the sewage is subjected to aerobic treatment;

activated sludge precipitation: the sewage after aerobic treatment enters a secondary sedimentation tank for sedimentation, part of biomembrane sludge is carried by water after falling off and enters the secondary sedimentation tank for sedimentation, the tail water at the upper layer is discharged after sedimentation, and the sediment at the lower layer flows back to the first biochemical pool and/or is discharged as residual sludge;

4. and (4) cleaning.

After working for 15 days, the reactor is cleaned, the air pressure in the ventilation cavity is increased to 3mpa of clean air pressure, sludge attached to the outside of the fiber layer is dispersed and falls off, and the original working efficiency is recovered.

5. And (4) evaluating the effect.

1. Survival amount of aerobic bacteria.

The total content of each strain in the biochemical pool in the traditional process is 5000mg/L, and the total content of each strain can reach 20000mg/L by adopting the biofilm reactor in the embodiment 5.

2. The sewage treatment efficiency.

The biochemical treatment of 10t/h sewage needs to be respectively 40m by adopting the traditional process ³ The anaerobic pool stays for 1 hour and 10m ³ The anoxic pond stays for 1 hour and 30m ³ The aerobic tank stays for 1 hour for 3 hours, and the discharge standard can be met;

compared with the traditional process, the internal oxygen supply biomembrane reaction unit is adopted and only needs to be 30m ³ The water stays in the pool for 1.5 hours to reach the discharge standard; great advantages are achieved in both time and space;

3. and (5) comparing energy consumption.

By adopting the traditional process, the gas-water ratio in the aerobic tank is 15-20: 1, i.e. per m ³ Water is required to be supplied in 15-20m ³ Gas, adopt interior oxygen suppliment biomembrane reaction unit, accessible control oxygen supply volume, adjust the gas-water ratio to its required 3 ~ 5:1, the energy consumption is only 20-25% of the traditional process.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A sewage treatment method is characterized in that the following biofilm reactor is adopted, and the method comprises the following steps:

equipment installation: putting the biofilm reactor into a first biochemical water tank, and fixing;

ventilating: connecting an air source;

water treatment: according to the preset pressure setting, the pressure in the ventilation cavity is adjusted to be stable, so that sewage treatment bacteria are attached to the fiber layer for sewage treatment;

the biofilm reactor comprises: oxygen transfer biomembrane reaction unit, frame, upper air pipe, lower air pipe and air source,

the oxygen transfer biological membrane reaction unit comprises an internal oxygen supply hollow breathable composite membrane tube, a combined tube assembly part and a support tube, wherein the internal oxygen supply hollow breathable composite membrane tube comprises a breathable membrane tube and a fiber layer covering the outer surface of the breathable membrane tube, the breathable membrane tube is made of a non-biodegradable material, uniform micropores are formed in the breathable membrane tube, and the pore diameter of each micropore is 0.01-30 mu m; the fiber layer is made of at least one of polyester resin and high-density polyethylene, the thickness of the fiber layer is 0.1-2.6mm, and the fiber layer is provided with a pore structure; the combined pipe assembly part comprises two rubber-pouring parts and two connecting parts, two ends of a plurality of inner oxygen supply hollow breathable composite membrane pipes are respectively fixed in the two rubber-pouring parts, inner cavities of the inner oxygen supply hollow breathable composite membrane pipes are opened on the surfaces of the rubber-pouring parts, each connecting part comprises a shell, the shell is fixedly connected with the rubber-pouring parts and covers the inner cavity opening of the inner oxygen supply hollow breathable composite membrane pipe on the rubber-pouring parts, a ventilation cavity is arranged in the shell and is communicated with the inner cavities of the inner oxygen supply hollow breathable composite membrane pipes, and the ventilation cavity is provided with an air inlet and/or an air outlet on the surface of the shell; two ends of the supporting tube are respectively fixedly installed with the two connecting pieces;

the oxygen transfer biomembrane reaction units are fixedly arranged in the frame, the upper air pipe is communicated with an air inlet or an air outlet of an upper connecting piece of the oxygen transfer biomembrane reaction unit, the lower air pipe is communicated with an air outlet or an air inlet of a lower connecting piece of the oxygen transfer biomembrane reaction unit, and the air source is communicated with the upper air pipe or the lower air pipe;

the breathable film tube is prepared by the following method:

adding 5wt% of silicon dioxide and 5wt% of titanium dioxide into a polytetrafluoroethylene raw material as a reinforcing agent; adding 10wt% of white mineral oil as an adhesive into a modified polytetrafluoroethylene raw material, and extruding the mixed raw material from a cold extrusion forming machine at high pressure from an extrusion port in an environment of 20-30 ℃ to extrude a pipe with the inner diameter of phi 0.5-phi 4mm and the outer diameter of phi 1.5-phi 5 mm; preheating the extruded high-density formed breathable membrane tube by a heater, bypassing two driving wheels with different rotating speeds, wherein the rotating speed of a rear driving wheel is 1.5-3 times that of a front driving wheel, so that uniform micropores are stretched out from the high-density breathable membrane tube, and adjusting the size of the stretched micropores to be 0.01-30 mu m by controlling the speed of the front driving wheel and the speed of the rear driving wheel to obtain the breathable membrane tube;

the fiber layer is prepared by winding and weaving a linear material on the surface of the breathable film tube, and the weaving method comprises the following steps: soaking the air-permeable membrane tube into a mixed solution of alcohol and Tween 20 emulsifier, taking out, and winding and weaving the linear material of high-density polyethylene and/or polyester resin on the surface of the air-permeable membrane tube by a knitting machine to obtain a material with a thickness of 0.1-2.6mm to obtain the fiber layer.

2. The wastewater treatment method according to claim 1, wherein in the step of water treatment, aerobic treatment is performed according to the following process conditions:

or

1) And (3) anoxic treatment: controlling the air supply pressure in the ventilation cavity to be stable, so that the dissolved oxygen in the first biochemical water tank is 0.1-1.0mg/L; nitrifying bacteria grow and attach to the fiber layer under the action of organic matters and oxygen in the sewage, nitrifying bacteria grow on the inner layer of the fiber layer, denitrifying bacteria grow on the outer layer of the fiber layer to form biomembrane sludge, and the sewage is subjected to denitrification treatment;

2) Activated sludge precipitation: the sewage after denitrification treatment enters a secondary sedimentation tank for sedimentation, part of biomembrane sludge is carried by water after falling off and enters the secondary sedimentation tank for sedimentation, the tail water at the upper layer is discharged after sedimentation, and the sediment at the lower layer flows back to the first biochemical water tank and/or is discharged as residual sludge.

3. The wastewater treatment method according to claim 1, wherein in the step of installing the apparatus, a plurality of the biofilm reactors are respectively placed in a first biochemical water tank and a second biochemical water tank which are sequentially communicated and are respectively fixed.

4. The sewage treatment method according to claim 3, wherein in the water treatment step, the advanced denitrification treatment is performed according to the following process conditions:

1) And (3) anoxic treatment: introducing sewage into the first biochemical water tank, and controlling the stable air supply pressure in the aeration cavity to ensure that the dissolved oxygen in the first biochemical water tank is 0.1-0.6mg/L; nitrifying bacteria and denitrifying bacteria grow and attach to the fiber layer under the action of organic matters and oxygen in the sewage, nitrifying bacteria grow on the inner layer of the fiber layer, denitrifying bacteria grow on the outer layer of the fiber layer to form biomembrane sludge, and the sewage is subjected to deep denitrification treatment;

or alternatively

or

2) And (3) anoxic treatment: guiding the sewage treated by the first biochemical water tank into the second biochemical water tank, and controlling the air supply pressure in the ventilation cavity to be stable so that the dissolved oxygen in the second biochemical water tank is 0.1-0.6mg/L; nitrifying bacteria and denitrifying bacteria grow and attach to the fiber layer under the action of organic matters and oxygen in the sewage, nitrifying bacteria grow on the inner layer of the fiber layer, denitrifying bacteria grow on the outer layer of the fiber layer to form biomembrane sludge, and the sewage is subjected to anoxic treatment;

5. The wastewater treatment method according to claim 1, wherein in the step of installing the apparatus, a plurality of biofilm reactors are respectively placed in a first biochemical water tank, a second biochemical water tank and a third biochemical water tank which are sequentially communicated and are respectively fixed;

2) And (3) anoxic treatment: guiding the sewage treated by the first biochemical water tank into the second biochemical water tank, and controlling the stable air supply pressure in the ventilation cavity to ensure that the dissolved oxygen in the second biochemical water tank is 0.1-0.6mg/L; nitrifying bacteria and denitrifying bacteria grow and attach to the fiber layer under the action of organic matters and oxygen in the sewage, nitrifying bacteria grow on the inner layer of the fiber layer, denitrifying bacteria grow on the outer layer of the fiber layer to form biomembrane sludge, and the sewage is subjected to anoxic treatment;

3) Aerobic treatment: guiding the sewage treated by the second biochemical water tank into the third biochemical water tank, and controlling the air supply pressure in the aeration cavity to be stable, so that the dissolved oxygen in the third biochemical water tank is more than 1.5mg/L; aerobic bacteria grow and attach to the fiber layer under the action of organic matters and oxygen in the sewage to form biomembrane sludge, and the sewage is subjected to aerobic treatment;

6. The wastewater treatment method according to claim 1, wherein the biofilm reactor further comprises an upper control valve and a lower control valve, the upper control valve is arranged on the upper air pipe and used for controlling the ventilation volume of the upper air pipe; the lower control valve is arranged on the lower air pipe and used for controlling the ventilation volume of the lower air pipe flow; and the pressure in the ventilation cavity is stabilized by adjusting the opening degrees of the upper control valve and the lower control valve.

7. The wastewater treatment method according to claim 1, wherein the biofilm reactor occupies 10 to 75% of the volume of the biochemical water pool.

8. The wastewater treatment method according to claim 1, further comprising a cleaning step of raising the air pressure in the aeration chamber to a cleaning air pressure to break down sludge adhering to the outside of the fiber layer.

9. The wastewater treatment method according to claim 7, wherein the cleaning air pressure is 2-3mpa.